U.S. patent application number 12/194885 was filed with the patent office on 2009-05-28 for golf ball layers formed of polyurethane-based and polyurea-based compositions incorporating block copolymers.
Invention is credited to Kevin M. Harris, Murali Rajagapalan, Shenshen Wu.
Application Number | 20090137342 12/194885 |
Document ID | / |
Family ID | 23801705 |
Filed Date | 2009-05-28 |
United States Patent
Application |
20090137342 |
Kind Code |
A1 |
Wu; Shenshen ; et
al. |
May 28, 2009 |
Golf Ball Layers Formed of Polyurethane-Based and Polyurea-Based
Compositions Incorporating Block Copolymers
Abstract
A golf ball including a core and a cover, wherein cover is
formed from a composition comprising the reaction product of a
prepolymer including a soft-segment comprising an amine-terminated
polyether and a hard segment including a uretdione of hexamethylene
diisocyanate; and an amine-terminated curing agent; wherein the
amine-terminated polyether has the structure: ##STR00001## where x
and z have a combined value of 3.6-8 and y is 9-50, R is an alkyl
group having 1-20 carbons, a phenyl group, a cyclic group, or
mixtures thereof, R.sub.1 is --(CH.sub.2).sub.a--, where a is 1-10,
a phenylene group, a cyclic group, or a mixture thereof, and
R.sub.3 is hydrogen, a methyl group, or a mixture thereof.
Inventors: |
Wu; Shenshen; (North
Dartmouth, MA) ; Rajagapalan; Murali; (South
Dartmouth, MA) ; Harris; Kevin M.; (New Bedford,
MA) |
Correspondence
Address: |
ACUSHNET COMPANY
333 BRIDGE STREET, P. O. BOX 965
FAIRHAVEN
MA
02719
US
|
Family ID: |
23801705 |
Appl. No.: |
12/194885 |
Filed: |
August 20, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11785496 |
Apr 18, 2007 |
7429629 |
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12194885 |
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10900468 |
Jul 28, 2004 |
7211624 |
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11785496 |
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10409092 |
Apr 9, 2003 |
6964621 |
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10900468 |
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10066637 |
Feb 6, 2002 |
6582326 |
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10409092 |
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09453701 |
Dec 3, 1999 |
6435986 |
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10066637 |
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10228311 |
Aug 27, 2002 |
6835794 |
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10409092 |
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09466434 |
Dec 17, 1999 |
6476176 |
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10228311 |
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09951963 |
Sep 13, 2001 |
6635716 |
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09466434 |
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60401047 |
Aug 6, 2002 |
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Current U.S.
Class: |
473/374 ;
473/377; 473/378 |
Current CPC
Class: |
A63B 37/0049 20130101;
A63B 37/0052 20130101; A63B 37/12 20130101; A63B 37/0039 20130101;
A63B 37/0045 20130101; A63B 37/0076 20130101; A63B 2209/00
20130101; A63B 37/0056 20130101; A63B 2225/60 20130101; A63B
37/0024 20130101; A63B 37/0075 20130101; A63B 37/0047 20130101;
A63B 37/0083 20130101; A63B 37/0027 20130101; A63B 37/008 20130101;
A63B 37/0074 20130101; A63B 37/0003 20130101 |
Class at
Publication: |
473/374 ;
473/377; 473/378 |
International
Class: |
A63B 37/02 20060101
A63B037/02; A63B 37/12 20060101 A63B037/12 |
Claims
1. A golf ball comprising a core and a cover, wherein cover is cast
from a composition comprising the reaction product of: a prepolymer
comprising the reaction product of a soft-segment comprising an
amine-terminated polyether and a hard segment comprising a mixture
of at least a first and second isocyanate; and an amine-terminated
curing agent; wherein the amine-terminated polyether has the
structure: ##STR00024## where x and z have a combined value of
3.6-8 and y is 9-50, R is an alkyl group having 1-20 carbons, a
phenyl group, a cyclic group, or mixtures thereof, R.sub.1 is
--(CH.sub.2).sub.a--, where a is 1-10, a phenylene group, a cyclic
group, or a mixture thereof, and R.sub.3 is hydrogen, a methyl
group, or a mixture thereof; and wherein the first isocyanate
comprises a isocyanurate trimer of hexamethylene diisocyanate and
the second isocyanate comprises a uretdione dimer of hexamethylene
diisocyanate.
2. The golf ball of claim 1, wherein R.sub.1 is
--(CH.sub.2).sub.4--.
3. The golf ball of claim 1, wherein R.sub.3 is hydrogen or
methyl.
4. The golf ball of claim 1, wherein the amine-terminated polyether
has a molecular weight of 1000 to 4000.
5. The golf ball of claim 4, wherein the amine-terminated polyether
has a molecular weight of 1500 to 2500.
6. The golf ball of claim 5, wherein the amine-terminated polyether
has a molecular weight of 2000.
7. The golf ball of claim 1, wherein the first and second
isocyanates have a number of unreacted NCO groups of 14% or
less.
8. The golf ball of claim 7, wherein the number of unreacted NCO
groups is 5% to 11%.
9. The golf ball of claim 8, wherein the number of unreacted NCO
groups is 6% to 9.5%.
10. The golf ball of claim 1, wherein the hard segment further
comprises a triisocyanate of hexamethylene diisocyanate.
11. The golf ball of claim 1, wherein the amine-terminated curing
agent comprises 3,5-diethyltoluene-2,4-diamine and
3,5-diethyltoluene-2,6-diamine.
12. The golf ball of claim 11, wherein the amine-terminated curing
agent further comprises
polytetramethyleneoxide-di-p-aminobenzoate.
13. The golf ball of claim 1, wherein the core comprises an inner
core layer and an outer core layer.
14. The golf ball of claim 1, wherein the golf ball comprises an
intermediate layer disposed between the core and the cover layer,
the intermediate layer comprising an ionomer and an ethylene-butene
copolymer produced using a single-site catalyst.
15. A golf ball comprising a core and a cover, wherein cover is
cast from a composition comprising the reaction product of: a
prepolymer comprising the reaction product of a soft-segment
comprising an amine-terminated polyether and a hard segment
consisting essentially of a uretdione of hexamethylene
diisocyanate; and an amine-terminated curing agent; wherein the
amine-terminated polyether has the structure: ##STR00025## where x
and z have a combined value of 3.6-8 and y is 9-50, R is an alkyl
group having 1-20 carbons, a phenyl group, a cyclic group, or
mixtures thereof, R.sub.1 is --(CH.sub.2).sub.a--, where a is 1-10,
a phenylene group, a cyclic group, or a mixture thereof, and
R.sub.3 is hydrogen, a methyl group, or a mixture thereof.
16. The golf ball of claim 15, wherein the golf ball comprises an
intermediate layer disposed between the core and the cover.
17. The golf ball of claim 15, wherein the core comprises an inner
core layer and an outer core layer.
18. A golf ball comprising a core, an intermediate layer, and a
cover, wherein cover is cast from a composition comprising the
reaction product of: a prepolymer comprising the reaction product
of a soft-segment comprising an amine-terminated polyether and a
hard segment consists essentially of a isocyanurate trimer of
hexamethylene diisocyanate and a uretdione dimer of hexamethylene
diisocyanate; and an amine-terminated curing agent; wherein the
amine-terminated polyether has the structure: ##STR00026## where x
and z have a combined value of 3.6-8 and y is 9-50, R is an alkyl
group having 1-20 carbons, a phenyl group, a cyclic group, or
mixtures thereof, R.sub.1 is --(CH.sub.2).sub.4--, and R.sub.3 is
hydrogen or methyl.
19. The golf ball of claim 18, wherein the core comprises an inner
core layer and an outer core layer.
20. The golf ball of claim 18, wherein the inner cover layer
comprises a thermoplastic material.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. patent
application Ser. No. 11/785,496, filed Apr. 18, 2007, which is a
continuation of U.S. patent application Ser. No. 10/900,468, filed
Jul. 28, 2004, now U.S. Pat. No. 7,211,624, which is a
continuation-in-part of U.S. patent application Ser. No.
10/409,092, filed Apr. 9, 2003, now U.S. Pat. No. 6,964,621, which
is a continuation-in-part of U.S. patent application Ser. No.
10/066,637, filed Feb. 6, 2002, now U.S. Pat. No. 6,582,326, which
is a continuation of U.S. patent application Ser. No. 09/453,701,
filed Dec. 3, 1999, now U.S. Pat. No. 6,435,986; and also a
continuation-in-part of U.S. patent application Ser. No.
10/228,311, filed Aug. 27, 2002, now U.S. Pat. No. 6,835,794, which
is a continuation-in-part of U.S. patent application Ser. No.
09/466,434, filed Dec. 17, 1999, now U.S. Pat. No. 6,476,176, and a
continuation-in-part of U.S. patent application Ser. No.
09/951,963, filed Sep. 13, 2001, now U.S. Pat. No. 6,635,716, and
also claims priority to U.S. Patent Provisional Application No.
60/401,047, filed Aug. 6, 2002. The entire disclosures of these
applications are incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The invention relates to golf equipment including
polyurethane-based compositions incorporating block copolymers,
polyurea-based compositions incorporating block copolymers, and
mixtures thereof. In particular, the present invention is directed
to golf equipment including compositions formed from the reaction
product of an isocyanate and a functionalized block copolymer. In
addition, the compositions of the present invention may be formed
from the reaction product of a prepolymer, which is based on an
isocyanate and a polyol or amine, and a functionalized block
copolymer. The compositions of the invention may also be formed by
reacting an excess of prepolymer, which is based on an isocyanate
and a polyol or amine, with a functionalized block copolymer to
form an intermediate prepolymer having the block copolymer portion
capped with isocyanate groups at each end, which is then reacted
with a curing agent to form a polyurethane-based or polyurea-based
composition.
BACKGROUND OF THE INVENTION
[0003] Golf equipment, i.e., clubs and balls, are formed from a
variety of compositions. For example, golf ball covers are formed
from a variety of materials, including balata and ionomer resins.
Balata is a natural or synthetic trans-polyisoprene rubber. Balata
covered balls are favored by more highly skilled golfers because
the softness of the cover allows the player to achieve spin rates
sufficient to more precisely control ball direction and distance,
particularly on shorter shots.
[0004] However, balata covered balls are easily damaged, and thus
lack the durability required by the average golfer. Accordingly,
alternative cover compositions have been developed in an attempt to
provide balls with spin rates and a feel approaching those of
balata covered balls, while also providing a golf ball with a
higher durability and overall distance.
[0005] Ionomer resins have, to a large extent, replaced balata as a
cover material. Chemically, ionomer resins are a copolymer of an
olefin and an .alpha.,.beta.-ethylenically-unsaturated carboxylic
acid having 10 to 90 percent of the carboxylic acid groups
neutralized by a metal ion, as disclosed in U.S. Pat. No.
3,264,272. Commercially available ionomer resins include, for
example, copolymers of ethylene and methacrylic or acrylic acid,
neutralized with metal salts. Examples of commercially available
ionomer resins include, but are not limited to, SURLYN.RTM. from
DuPont de Nemours and Company, and ESCOR.RTM. and IOTEK.RTM. from
Exxon Corporation. These ionomer resins are distinguished by the
type of metal ion, the amount of acid, and the degree of
neutralization.
[0006] U.S. Pat. Nos. 3,454,280, 3,819,768, 4,323,247, 4,526,375,
4,884,814, and 4,911,451 all relate to the use of SURLYN.RTM.-type
compositions in golf ball covers. However, while SURLYN.RTM.
covered golf balls, as described in the preceding patents, possess
virtually cut-proof covers, the spin and feel are inferior compared
to balata covered balls.
[0007] Polyurethanes have also been recognized as useful materials
for golf ball covers since about 1960. U.S. Pat. No. 3,147,324 is
directed to a method of making a golf ball having a polyurethane
cover. The resulting golf balls are durable, while at the same time
maintaining the "feel" of a balata ball.
[0008] Various companies have investigated the usefulness of
polyurethane as a golf ball cover material. U.S. Pat. No. 4,123,061
teaches a golf ball made from a polyurethane prepolymer formed of
polyether with diisocyanate that is cured with either a polyol or
an amine-type curing agent. U.S. Pat. No. 5,334,673 discloses the
use of two categories of polyurethane available on the market,
i.e., thermoset and thermoplastic polyurethanes, for forming golf
ball covers and, in particular, thermoset polyurethane covered golf
balls made from a composition of polyurethane prepolymer and a
slow-reacting amine curing agent, and/or a glycol.
[0009] Unlike SURLYN.RTM. covered golf balls, polyurethane golf
ball covers can be formulated to possess the soft "feel" of balata
covered golf balls. However, golf ball covers made from
polyurethane have not, to date, fully matched SURLYN.RTM. golf
balls with respect to resilience or the rebound of the golf ball
cover, which is a function of the initial velocity of a golf ball
after impact with a golf club.
[0010] Furthermore, because the polyurethanes used to make the
covers of such golf balls generally contain an aromatic component,
e.g., aromatic diisocyanate, polyol, or polyamine, they are
susceptible to discoloration upon exposure to light, particularly
ultraviolet (UV) light. To slow down the discoloration, light and
UV stabilizers, e.g., TINUVIN.RTM. 770, 765, and 328, are added to
these aromatic polymeric materials. However, to further ensure that
the covers formed from aromatic polyurethanes do not appear
discolored, the covers are painted with white paint and then
covered with a clear coat to maintain the white color of the golf
ball. The application of a uniform white pigmented coat to the
dimpled surface of the golf ball is a difficult process that adds
time and costs to the manufacture of a golf ball.
[0011] In addition, while certain polyols provide more stability to
the polyurethane polymer in terms of moisture resistance,
polyurethanes remain highly susceptible to changes in their
physical properties due to absorption of moisture. To avoid
moisture absorption, manufacturers have attempted to use moisture
barrier layers, e.g., U.S. Pat. No. 5,820,488, located between the
core and the cover. However, there still remains a need for
materials that are resistant to absorption of moisture suitable for
forming a golf ball component.
[0012] Polyureas have also been proposed as cover materials for
golf balls. For instance, U.S. Pat. No. 5,484,870 discloses a
polyurea composition comprising the reaction product of an organic
isocyanate and an organic amine, each having at least two
functional groups. Once these two ingredients are combined, the
polyurea is formed, and thus the ability to vary the physical
properties of the composition is limited. Like polyurethanes,
polyureas are not completely comparable to SURLYN.RTM. golf balls
with respect to resilience or the rebound or damping behavior of
the golf ball cover.
[0013] Therefore, there remains a continuing need for golf
equipment having soft components that provide improved resilience,
increased cut, scratch and abrasion resistance, moisture
resistance, and enhanced adherence without adversely affecting
overall performance characteristics of the golf balls. Thus, it
would be advantageous to provide a composition that combines the
cut and scratch resistance with improved resistance to
discoloration and moisture that are suitable for forming golf ball
components and other golf-related equipment.
SUMMARY OF THE INVENTION
[0014] The present invention is generally directed to golf
equipment having at least a portion formed of a polyurea
composition. In one embodiment, the present invention is directed
to one-piece golf balls including polyurea. In another embodiment,
the compositions of the invention are used in two-piece and
multi-component, e.g., three-piece, four-piece, etc. golf balls
including at least one cover layer and a core, wherein at least one
cover layer includes at least one polyurea, as well as
multi-component golf balls including cores and/or covers having two
or more layers, wherein at least one such layer(s) is formed of at
least one polyurea.
[0015] For example, one aspect of the invention is directed to a
golf ball having a core and a cover, wherein the cover is formed
from a reactive product composition including an isocyanate and an
amine-terminated compound selected from the group consisting
of:
##STR00002## ##STR00003##
and mixtures thereof, wherein n, x, y, and z are about 1 or
greater, preferably about 1 to about 20, wherein R is an alkyl
group having about 1 to about 20 carbon atoms, preferably about 1
to about 12 carbon atoms, a phenyl group; a cyclic group; or
mixtures thereof, wherein R.sub.1 and R.sub.2 are alkylene groups
having about 1 to about 20 carbon atoms, preferably about 1 to
about 12 carbon atoms, phenylene groups, cyclic groups, or mixtures
thereof, and wherein R.sub.3 is a hydrogen, a methyl group, or a
mixture thereof.
[0016] In one embodiment, the composition includes linkages having
the general formulae:
##STR00004##
or mixtures thereof, wherein x is the chain length, i.e., about 1
or greater, and wherein R and R.sub.1 are straight chain or
branched hydrocarbon chains having about 1 to about 20 carbons. In
another embodiment, the composition includes only linkages having
the general formula:
##STR00005##
wherein x is the chain length, i.e., about 1 or greater, and
wherein R and R.sub.1 are straight chain or branched hydrocarbon
chains having about 1 to about 20 carbons.
[0017] The composition may further include a curing agent selected
from the group consisting of hydroxy-terminated curing agents,
amine-terminated curing agents, and mixtures thereof. In one
embodiment, the amine-terminated curing agent is a secondary
diamine curing agent. In another embodiment, the amine-terminated
curing agents are selected from the group consisting of ethylene
diamine; hexamethylene diamine; 1-methyl-2,6-cyclohexyl diamine;
2,2,4- and 2,4,4-trimethyl-1,6-hexanediamine;
4,4'-bis-(sec-butylamino)-dicyclohexylmethane;
N,N'-diisopropyl-isophorone diamine;
1,4-bis-(sec-butylamino)-cyclohexane;
1,2-bis-(sec-butylamino)-cyclohexane; derivatives of
4,4'-bis-(sec-butylamino)-dicyclohexylmethane;
4,4'-dicyclohexylmethane diamine;
1,4-cyclohexane-bis-(methylamine);
1,3-cyclohexane-bis-(methylamine); diethylene glycol
bis-(aminopropyl)ether; 2-methylpentamethylene-diamine;
diaminocyclohexane; diethylene triamine; triethylene tetramine;
tetraethylene pentamine; propylene diamine; 1,3-diaminopropane;
dimethylamino propylamine; diethylamino propylamine;
imido-bis-(propylamine); monoethanolamine, diethanolamine;
triethanolamine; monoisopropanolamine, diisopropanolamine;
isophoronediamine; polyoxypropylene diamine; propylene oxide-based
triamine; 3,3'-dimethyl-4,4'-diaminocyclohexylmethane; and mixtures
thereof.
[0018] The cover preferably has a difference in yellowness index
(.DELTA.YI) of about 12 or less after 5 days of ultraviolet light
exposure. In addition, the cover preferably has a difference in b
chroma dimension of about 6 or less after 5 days of ultraviolet
light exposure.
[0019] In one embodiment, the composition may include at least one
density-adjusting filler.
[0020] The present invention is also directed to a golf ball
including a core, a layer, which may include at least one
thermoplastic or thermoset non-ionomeric material, disposed about
the core to create an inner ball, and a cover cast onto the inner
ball, wherein the cover includes a light stable polyurea material
including at least one isocyanate, at least one amime-terminated
compound, and at least one curing agent comprising a
hydroxy-terminated curing agent, an amine-terminated curing agent,
or a mixture thereof. The amine-terminated compound may be selected
from the group consisting of amine-terminated hydrocarbons,
amine-terminated polyethers, amine-terminated polyesters,
amine-terminated polycaprolactones, amine-terminated
polycarbonates, amine-terminated polyamides, and mixtures thereof.
In one embodiment, the amine-terminated compound comprises primary
amines, secondary amines, triamines, or combinations thereof.
[0021] In another embodiment, the cover has a thickness of about
0.02 inches to about 0.035 inches. In yet another embodiment, the
layer has a first Shore D hardness and the cover has a second Shore
D hardness, and wherein the ratio of second Shore D hardness to the
first Shore D hardness is about 0.7 or less. In still another
embodiment, the core has a diameter of about 1.55 or greater.
[0022] The inner ball may include a moisture barrier layer. In one
embodiment, the inner ball is surface treated.
[0023] The present invention also relates to a golf ball including
a core, an intermediate layer having a hardness of about 60 Shore D
or greater, and a cover formed of a polyurea material comprising at
least one isocyanate and at least one amine-terminated compound,
wherein the cover has a hardness of about 30 Shore D to about Shore
60, and wherein the golf ball has a COR of about 0.800 or
greater.
[0024] The amine-terminated compound is selected from the group
consisting of amine-terminated hydrocarbons, amine-terminated
polyethers, amine-terminated polyesters, amine-terminated
polycaprolactones, amine-terminated polycarbonates,
amine-terminated polyamides, and mixtures thereof. In addition, the
polyurea material may further include a curing agent selected from
the group consisting of a hydroxy-terminated curing agent, an
amine-terminated curing agent, and mixtures thereof.
[0025] In one embodiment, the ratio of the cover hardness to the
intermediate layer hardness is about 0.7 or less. In another
embodiment, the cover has a thickness of about 0.2 inches to about
0.035 inches.
[0026] In still another embodiment, the intermediate layer includes
an ionomeric material. In an alternate embodiment, the intermediate
layer comprises a thermoset non-ionomeric material, a thermoplastic
non-ionomeric material, or mixtures thereof.
[0027] The present invention is also directed to a golf ball
including at least a cover and at least one core layer wherein the
cover is formed from a composition including at least one polyurea
composition formed from a polyurea prepolymer, i.e., an isocyanate
and an amine-terminated compound, cured with a curing agent.
[0028] The present invention is further directed to a golf ball
including a cover, a core and at least one intermediate layer
interposed between the cover and an outermost core layer, wherein
the intermediate layer is formed from a composition including a
polyurea prepolymer, i.e., an isocyanate and an amine-terminated
compound, cured with a curing agent.
[0029] The present invention is yet further directed to a golf ball
including a cover, a core, and at least one intermediate layer
interposed between the cover and the core, wherein the outermost
cover layer and at least one intermediate layer are both formed
from a polyurea composition including a polyurea prepolymer, i.e.,
an isocyanate and an amine-terminated compound, cured with a curing
agent.
[0030] In another embodiment of the present invention, the cover
preferably includes from about 1 to about 100 weight percent of the
polyurea, with the remainder of the cover, if any, including at
least one other polymer known to one of ordinary skill in the art.
In another embodiment, the cover preferably includes from about 1
to about 100 weight percent of the polyurea, with the remainder of
the cover, if any, including one or more compatible, resilient
polymers such as would be known to one of ordinary skill in the
art.
[0031] The invention is further directed to a golf ball including
at least one light stable cover layer formed from a composition
including at least one polyurea formed from a polyurea prepolymer
and a curing agent. In one embodiment, the polyurea prepolymer
includes at least one isocyanate and at least one amine-terminated
compound.
[0032] In this aspect of the invention, the isocyanate is
saturated, and selected from the group consisting of ethylene
diisocyanate; propylene-1,2-diisocyanate; tetramethylene
diisocyanate; tetramethylene-1,4-diisocyanate; 1,6-hexamethylene
diisocyanate; octamethylene diisocyanate; decamethylene
diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate;
2,4,4-trimethylhexamethylene diisocyanate;
dodecane-1,12-diisocyanate; cyclobutane-1,3-diisocyanate;
cyclohexane-1,2-diisocyanate; cyclohexane-1,3-diisocyanate;
cyclohexane-1,4-diisocyanate; methylcyclohexylene diisocyanate;
2,4-methylcyclohexane diisocyanate; 2,6-methylcyclohexane
diisocyanate; 4,4'-dicyclohexyl diisocyanate; 2,4'-dicyclohexyl
diisocyanate; 1,3,5-cyclohexane triisocyanate;
isocyanatomethylcyclohexane isocyanate;
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane;
isocyanatoethylcyclohexane isocyanate;
bis(isocyanatomethyl)-cyclohexane diisocyanate;
4,4'-bis(isocyanatomethyl) dicyclohexane;
2,4'-bis(isocyanatomethyl) dicyclohexane; isophoronediisocyanate;
triisocyanate of HDI; triisocyanate of 2,2,4-trimethyl-1,6-hexane
diisocyanate; dicyclohexylmethane diisocyanate;
4,4'-dicyclohexylmethane diisocyanate; 2,4-hexahydrotoluene
diisocyanate; 2,6-hexahydrotoluene diisocyanate; and mixtures
thereof. The saturated diisocyanate is preferably selected from the
group consisting of isophoronediisocyanate,
4,4'-dicyclohexylmethane diisocyanate, 1,6-hexamethylene
diisocyanate, or a combination thereof.
[0033] In another embodiment, the isocyanate is an aromatic
aliphatic isocyanate selected from the group consisting of
meta-tetramethylxylene diisocyanate; para-tetramethylxylene
diisocyanate; trimerized isocyanurate of a polyisocyanate;
dimerized uretdione of a polyisocyanate; a modified polyisocyanate;
and mixtures thereof.
[0034] The amine-terminated compound may be a polyether amine
selected from the group consisting of polytetramethylene ether
diamines, polyoxypropylene diamines, poly(ethylene oxide capped
oxypropylene) ether diamines, triethyleneglycoldiamines, propylene
oxide-based triamines, trimethylolpropane-based triamines,
glycerin-based triamines, and mixtures thereof. In one embodiment,
the polyether amine has a molecular weight of about 1000 to about
3000.
[0035] The curing agent may be selected from the group consisting
of hydroxy-terminated curing agents, amine-terminated curing
agents, and mixtures thereof. In one embodiment, the
hydroxy-terminated curing agents are selected from the group
consisting of ethylene glycol; diethylene glycol; polyethylene
glycol; propylene glycol; 2-methyl-1,3-propanediol;
2-methyl-1,4-butanediol; dipropylene glycol; polypropylene glycol;
1,2-butanediol; 1,3-butanediol; 1,4-butanediol; 2,3-butanediol;
2,3-dimethyl-2,3-butanediol; trimethylolpropane;
cyclohexyldimethylol; triisopropanolamine;
N,N,N',N'-tetra-(2-hydroxypropyl)-ethylene diamine; diethylene
glycol bis-(aminopropyl)ether; 1,5-pentanediol; 1,6-hexanediol;
1,3-bis-(2-hydroxyethoxy)cyclohexane; 1,4-cyclohexyldimethylol;
1,3-bis-[2-(2-hydroxyethoxy)ethoxy]-cyclohexane;
1,3-bis-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy} cyclohexane;
trimethylolpropane; polytetramethylene ether glycol, preferably
having a molecular weight from about 250 to about 3900; and
mixtures thereof.
[0036] The amine-terminated curing agents may be selected from the
group consisting of ethylene diamine; hexamethylene diamine;
1-methyl-2,6-cyclohexyl diamine; 2,2,4- and
2,4,4-trimethyl-1,6-hexanediamine;
4,4'-bis-(sec-butylamino)-dicyclohexylmethane;
1,4-bis-(sec-butylamino)-cyclohexane;
1,2-bis-(sec-butylamino)-cyclohexane; derivatives of
4,4'-bis-(sec-butylamino)-dicyclohexylmethane;
4,4'-dicyclohexylmethane diamine;
1,4-cyclohexane-bis-(methylamine);
1,3-cyclohexane-bis-(methylamine); diethylene glycol
bis-(aminopropyl)ether; 2-methylpentamethylene-diamine;
diaminocyclohexane; diethylene triamine; triethylene tetramine;
tetraethylene pentamine; propylene diamine; 1,3-diaminopropane;
dimethylamino propylamine; diethylamino propylamine;
imido-(bis-propylamine); monoethanolamine, diethanolamine;
triethanolamine; monoisopropanolamine, diisopropanolamine;
isophoronediamine; and mixtures thereof.
[0037] In one embodiment, the composition further includes a
catalyst selected from the group consisting of a bismuth catalyst,
zinc octoate, bis-butyltin dilaurate, bis-butyltin diacetate, tin
(II) chloride, tin (IV) chloride, bis-butyltin dimethoxide,
dimethyl-bis[1-oxonedecyl)oxy]stannane, di-n-octyltin bis-isooctyl
mercaptoacetate, triethylenediamine, triethylamine, tributylamine,
oleic acid, acetic acid; delayed catalysts, and mixtures thereof.
The catalyst may be present from about 0.005 percent to about 1
percent by weight of the composition.
[0038] In another embodiment, the cover layer has a difference in
yellowness index (.DELTA.YI) of about 12 or less after 5 days of
ultraviolet light exposure. In yet another embodiment, the cover
layer has a difference in b* dimension of about 6 or less after 5
days of ultraviolet light exposure.
[0039] In this aspect of the invention, the cover layer may be
formed from casting, injection molding, compression molding,
reaction injection molding, and mixtures thereof, as well as other
polymer processes known to those of ordinary skill in the art.
[0040] The present invention is also directed to a golf ball
including a core, a layer disposed about the core forming a center,
and a cover cast onto the center, wherein the cover comprises a
light stable polyurea material comprising at least an isocyanate
and an amine-terminated compound, and at least one of a
hydroxy-terminated curing agent, a amine-terminated curing agent,
or a mixture thereof.
[0041] In one embodiment, the layer includes ionomers, polyamides,
highly neutralized polymers, polyesters, polycarbonates,
polyimides, polyolefins, acid copolymers, polyurethanes, vinyl
resins, acrylic resins, polyphenylene oxide resins,
metallocene-catalyzed polymers, and mixtures thereof. In another
embodiment, the layer is a moisture barrier layer.
[0042] In yet another embodiment, the cover has a thickness of
about 0.02 inches to about 0.035 inches. In addition, the layer
preferably has a first Shore D hardness and the cover has a second
Shore D hardness, wherein the ratio of second Shore D hardness to
the first Shore D hardness is about 0.7 or less.
[0043] The core may include polybutadiene and may have a diameter
of about 1.55 or greater. In one embodiment, the core includes a
cis-to-trans catalyst, a resilient polymer component, and a free
radical source. The cis-to-trans catalyst may include an
organosulfur component, preferably including a metal salt, a Group
VIA component, an inorganic sulfide component, an aromatic organic
compound, or mixtures thereof.
[0044] In one embodiment, at least one of the core, the layer, the
cover, or combinations thereof comprise a density-adjusting
filler.
[0045] The present invention is also directed to a method of
forming a golf ball including the steps of providing a golf ball
center, mixing a polyurea prepolymer and at least one curing agent
to form a castable reactive polyurea liquid material, filling a
first set of mold halves with a first amount of the material,
lowering the center into the first set of mold halves after a first
predetermined time, wherein the center is held by vacuum for a
second predetermined time, and wherein the second predetermined
time is sufficient for complete exothermic reaction of the first
amount of material, releasing the center from the vacuum providing
a partially covered center, filling a second set of mold halves
with a second amount of the material, wherein the first and second
amounts are substantially similar, and wherein an exothermic
reaction of the second amount commences, and mating the second set
of mold halves with the partially covered center, wherein the
exothermic reaction of the second amount concludes.
[0046] In one embodiment, the first predetermined time is about 40
seconds to about 100 seconds. In another embodiment, the second
predetermined time is about 4 seconds to about 12 seconds.
[0047] The polyurea prepolymer may include at least one isocyanate
and at least one amine-terminated compound. In one embodiment, the
step of mixing a polyurea prepolymer and at least one curing agent
further includes mixing at least one triol or at least one tetraol,
or mixtures thereof. In another embodiment, the step of mixing a
polyurea prepolymer and at least one curing agent further includes
mixing at least one catalyst, at least one light stabilizer, at
least one defoaming agent, at least one acid functionalized moiety,
or combinations thereof.
[0048] In yet another embodiment, the step of providing a golf ball
center includes the steps of providing a golf ball core and forming
a layer disposed about the golf ball core. In still another
embodiment, the golf ball core includes a polybutadiene reaction
product, wherein the core has a diameter of about 1.55 inches or
greater, and wherein the layer has a thickness of about 0.02 inches
to about 0.035 inches.
[0049] The present invention is also directed to a golf ball having
at least one layer, formed of a water resistant polyurea or
polyurethane elastomer. In particular, this aspect of the invention
relates to a golf ball having at least one layer, such layer(s)
being formed of a water resistant polyurea or polyurethane. In one
embodiment, a one-piece golf ball is formed from a water resistant
elastomer. In other embodiments, multi-layer balls are formed with
at least a portion including the water resistant elastomers of the
invention. In this aspect of the invention, the intermediate layer,
cover layer(s), and/or core may be formed, as a whole or in part,
with the water resistant elastomeric composition.
[0050] The water resistant polyurethane elastomers of the invention
are the reaction product of at least one isocyanate, at least one
polyol and at least one curing agent, wherein the polyol and/or the
curing agent is based on a hydrophobic backbone. The water
resistant polyurea elastomer is the reaction product of at least
one isocyanate and at least one amine-terminated polyol, wherein
the amine-terminated polyol and/or the curing agent is based on a
hydrophobic backbone.
[0051] The water resistant elastomers of the present invention may
be used in forming any portion of a golf ball, portions of golf
clubs, shoes, or bags. When used in a golf ball, the water
resistant elastomer preferably is included in a layer composition
from about 1 percent to about 100 percent by weight of the layer
composition.
[0052] In one embodiment, a golf ball of the invention includes a
core and a cover, wherein at least a portion of the golf ball is
formed from a water resistant polyurea composition including an
isocyanate, an amine-terminated compound comprising a hydrophobic
backbone, and a curing agent. The amine-terminated compound may
include at least one of an unsaturated amine-terminated
hydrocarbon, a saturated amine-terminated hydrocarbon, or mixtures
thereof. In addition, the curing agent may be selected from the
group consisting of hydroxy-terminated curing agents,
amine-terminated curing agents, and mixtures thereof. In another
embodiment, the curing agent is selected from the group consisting
of primary diamine curing agents, secondary diamine curing agents,
triamines, and combinations thereof, preferably a secondary diamine
curing agent. In this aspect of the invention, the golf ball
preferably has a weight gain of about 0.15 grams or less after a
seven week storage period in 100 percent humidity at 72.degree. F.
In one embodiment, the golf ball has a weight gain of about 0.09
grams or less after a seven week storage period in 100 percent
humidity at 72.degree. F. The water resistant polyurea composition
may also include at least one density-adjusting filler. And, in one
embodiment, the water resistant polyurea composition consists of
only urea linkages.
[0053] In a second embodiment of this aspect of the invention, a
golf ball may include a core having a diameter of about 1.55 or
greater, an intermediate layer disposed about the core to create a
center, and a cover having a thickness of about 0.02 inches to
about 0.035 inches disposed about the center, wherein the cover
includes a water resistant polyurea material including at least one
amine-terminated compound comprising a hydrophobic backbone and at
least one isocyanate. In this embodiment, the golf ball preferably
has a weight gain of about 0.05 grams or less after a seven week
storage period in 100 percent humidity at 72.degree. F.
[0054] In one embodiment, the amine-terminated compound includes at
least one amine-terminated hydrocarbon. In another embodiment, the
cover has first hardness and the intermediate layer has a second
hardness greater than the first hardness. For example, the first
hardness may be about 40 Shore D to about 55 Shore D and the second
hardness may be about 60 Shore D or greater. Also, the core may
include a first layer and a second layer. In one embodiment, the
core hardness is about 60 Shore D or less.
[0055] In a third embodiment of this aspect of the invention, a
golf ball may include a water resistant polyurea composition
including at least one amine-terminated compound having at least
one hydrophobic backbone, wherein the golf ball has a weight gain
of about 0.15 grams or less and a size gain of about 0.001 inches
or less after a seven week storage period in 100 percent humidity
at 72.degree. F. In one embodiment, the water resistant polyurea
composition further includes an isocyanate and a curing agent. In
another embodiment, the curing is selected from the group
consisting of ethylene diamine; hexamethylene diamine;
1-methyl-2,6-cyclohexyl diamine; 2,2,4- and
2,4,4-trimethyl-1,6-hexanediamine;
4,4'-bis-(sec-butylamino)-dicyclohexylmethane and derivatives
thereof; 1,4-bis-(sec-butylamino)-cyclohexane;
1,2-bis-(sec-butylamino)-cyclohexane; 4,4'-dicyclohexylmethane
diamine; 1,4-cyclohexane-bis-(methylamine);
1,3-cyclohexane-bis-(methylamine); diethylene glycol
bis-(aminopropyl)ether; 2-methylpentamethylene-diamine;
diaminocyclohexane; diethylene triamine; triethylene tetramine;
tetraethylene pentamine; propylene diamine; 1,3-diaminopropane;
dimethylamino propylamine; diethylamino propylamine;
imido-bis-(propylamine); monoethanolamine, diethanolamine;
triethanolamine; monoisopropanolamine, diisopropanolamine;
isophoronediamine; 4,4'-methylenebis-(2-chloroaniline);
3,5-dimethylthio-2,4-toluenediamine;
3,5-dimethylthio-2,6-toluenediamine;
3,5-diethylthio-2,4-toluenediamine;
3,5-diethylthio-2,6-toluenediamine;
4,4'-bis-(sec-butylamino)-diphenylmethane and derivatives thereof;
1,4-bis-(sec-butylamino)-benzene; 1,2-bis-(sec-butylamino)-benzene;
N,N'-dialkylamino-diphenylmethane;
trimethyleneglycol-di-p-aminobenzoate;
polytetramethyleneoxide-di-p-aminobenzoate;
4,4'-methylenebis-(3-chloro-2,6-diethyleneaniline);
4,4'-methylenebis-(2,6-diethylaniline); meta-phenylenediamine;
paraphenylenediamine; N,N'-diisopropyl-isophoronediamine;
polyoxypropylene diamine; propylene oxide-based triamine;
3,3'-dimethyl-4,4'-diaminocyclohexylmethane; and mixtures thereof.
In this aspect of the invention, the golf ball may have a
polybutadiene core.
[0056] Golf balls of the invention may also be formed having at
least a cover and at least one core layer, wherein at least one
water resistant polyurethane elastomer is included in the cover of
the golf ball. In another embodiment, the golf ball has a cover, a
core, and at least one intermediate layer interposed between the
cover and an outermost core layer, wherein the intermediate layer
is formed from a composition including at least one water resistant
polyurethane elastomer. In yet another embodiment, the golf ball
has a cover, a core, and at least one intermediate layer interposed
between the cover and the core, wherein the outermost cover layer
and at least one intermediate layer are both formed from a
composition including at least one water resistant polyurethane
elastomer.
[0057] The water resistant polyurethane elastomers used in forming
the golf balls of the present invention can be formed in accordance
with the teachings described in U.S. Pat. Nos. 5,334,673 and
5,733,428, which are incorporated by reference in their entirety
herein.
[0058] The present invention is also directed to a golf ball
including a core and a cover, wherein at least a portion of the
golf ball, e.g., a cover, is formed from a composition including an
isocyanate, which may be saturated, and a block copolymer, wherein
the block copolymer includes an A.sub.x-B.sub.y-A.sub.z, block and
includes at least one functional group at a terminal end of the
A.sub.x-B.sub.y-A.sub.z block, and wherein x, y, and z are
independently 1 or greater.
[0059] In one embodiment, A includes an olefin and B includes a
diene. In another embodiment, the diene is butadiene. The olefin
may be selected from the group consisting of ethylene, propylene,
styrene, and mixtures thereof.
[0060] In this aspect of the invention, the block copolymer may
include styrene-butadiene-styrene block copolymer. In one
embodiment, the at least one functional group includes a hydroxyl
group, an amino group, a thiol group, an epoxy group, an anhydride
group, or a combination thereof. The composition may include at
least one density-adjusting filler, nanoparticles, or a mixture
thereof.
[0061] The present invention may also include a golf ball including
a core and a cover, wherein at least a portion of the golf ball,
e.g., a cover, is formed from an isocyanate and a block copolymer
including at least one functional group at a terminal end of the
block copolymer, wherein the block copolymer includes an
A.sub.x-B.sub.y block, and wherein x and y are independently 1 or
greater. In one embodiment, A includes an olefin and B includes a
diene.
[0062] In another embodiment, A includes styrene and B includes
butadiene. Furthermore, the functional group can include at least
one of a hydroxy group, an amino group, a thiol group, an epoxy
group, an anhydride group, or a combination thereof.
[0063] In this aspect of the invention, the cover may include an
inner cover layer and an outer cover layer. And, in one embodiment,
the inner cover layer includes a thermoplastic material.
Furthermore, the portion of the golf ball may include the outer
cover layer.
[0064] The present invention also relates to a golf ball including
a core and a cover, wherein the cover is formed from a composition
including an isocyanate and a styrene-butadiene-styrene block
copolymer having functional groups at the terminal ends of the
block copolymer. The golf ball may also include an intermediate
layer. In one embodiment, the intermediate layer includes a
thermoplastic material. In another embodiment, the functional
groups are selected from the group consisting of hydroxy groups,
amino groups, thiol groups, epoxy groups, anhydride groups, and
combinations thereof. In still another embodiment, the cover has an
inner cover layer having a hardness of about 50 Shore D to about 70
Shore D and an outer cover layer having a hardness of about 30
Shore D to about 70 Shore D.
[0065] Another aspect of the invention relates to a golf ball
including a core and a cover, wherein the cover is formed from a
polyurethane-based composition including a prepolymer, a block
copolymer, and a coupling agent, and wherein the prepolymer is
formed from an isocyanate and a polyol. In one embodiment, the
block copolymer includes an olefin-diene-olefin block. In another
embodiment, the olefin is styrene and the diene is butadiene. In
still another embodiment, the coupling agent includes a hydroxy
group, an amino group, a thiol group, an epoxy group, an anhydride
group, or a combination thereof. For example, the coupling agent
may be selected from the group consisting of trimethylolpropane
monoallyl ether; N-methylolacrylamide;
1,1-dihydroxymethylcyclohex-3-ene;
1,2-dihydroxymethylcyclohex-4-ene; 1-amino-ethenol;
1-amino-2-propen-1-ol; 1-amino-1-propen-2-ol;
1-amino-4-penten-2-ol; 1-amino-4-hexen-3-ol; 1-amino-3-penten-2-ol;
1-amino-1-hepten-2-ol; 1-amino-3-nonen-2-ol; 2-amino-ethenol;
2-amino-3-buten-1-ol; 2-amino-4-pentene-1-ol; 2-amino-5-hexen-1-ol;
2-amino-3,14-octadecadien-1-ol; 2-amino-3,8-octadecadien-1-ol;
2-amino-3,9-octadecadien-1-ol; 8-amino-1-octen-4-ol;
4-amino-2-buten-2-ol; 4-amino-1-penten-3-ol;
4-amino-1,5-hexadiene-3-ol; 4-amino-2,5-hexadiene-1-ol; ethynol;
4-amino-2-butyn-1-ol; 1-amino-1-hydroxy-2-butenyl;
1-amino-3-pentyn-2-ol; 1-amino-3-decyn-2-ol; and mixtures thereof.
In yet another embodiment, the composition includes crosslinks. In
the alternative, the composition can be thermoplastic.
[0066] The present invention is also directed to a golf ball
including a core and a cover, wherein the cover is formed from a
polyurea composition including a prepolymer, a block copolymer
including at least one functional group at a terminal end, and a
curative, wherein the prepolymer is formed from an isocyanate and a
polyamine. The golf ball may further include an intermediate layer
disposed between the core and the cover, which may be formed from,
at least in part, a thermoplastic material, e.g., an ionomer resin.
In this aspect of the invention, the at least one functional group
may be selected from the group consisting of a hydroxy group, an
amino group, a thiol group, an epoxy group, an anhydride group, and
combinations thereof. In one embodiment, the block copolymer
includes an A.sub.x-B.sub.y-A.sub.z block, wherein x, y, and z are
independently 1 or greater, and wherein A includes an olefin and B
includes a diene. In another embodiment, the block copolymer
includes an A.sub.x-B.sub.y block, wherein x and y are
independently 1 or greater, and wherein A includes an olefin and B
includes a diene.
[0067] The present invention also relates to a golf ball including
a core and a cover, wherein at least a portion of the golf ball is
formed from a polyurea composition formed from a prepolymer, an
olefin-diene-olefin block copolymer, and a coupling agent. The golf
ball may include an intermediate layer formed from a thermoplastic
material. Furthermore, the coupling agent may be selected from the
group consisting of trimethylolpropane monoallyl ether;
N-methylolacrylamide; 1,1-dihydroxymethylcyclohex-3-ene;
1,2-dihydroxymethylcyclohex-4-ene; 1-amino-ethenol;
1-amino-2-propen-1-ol; 1-amino-1-propen-2-ol;
1-amino-4-penten-2-ol; 1-amino-4-hexen-3-ol; 1-amino-3-penten-2-ol;
1-amino-1-hepten-2-ol; 1-amino-3-nonen-2-ol; 2-amino-ethenol;
2-amino-3-buten-1-ol; 2-amino-4-pentene-1-ol; 2-amino-5-hexen-1-ol;
2-amino-3,14-octadecadien-1-ol; 2-amino-3,8-octadecadien-1-ol;
2-amino-3,9-octadecadien-1-ol; 8-amino-1-octen-4-ol;
4-amino-2-buten-2-ol; 4-amino-1-penten-3-ol;
4-amino-1,5-hexadiene-3-ol; 4-amino-2,5-hexadiene-1-ol; ethynol;
4-amino-2-butyn-1-ol; 1-amino-1-hydroxy-2-butenyl;
1-amino-3-pentyn-2-ol; 1-amino-3-decyn-2-ol; and mixtures thereof.
In this aspect of the invention, the block copolymer may include
styrene-butadiene-styrene block copolymer. Furthermore, the cover
may have a thickness of about 0.02 inches to about 0.035 inches. In
one embodiment, the cover has an inner cover layer having a
hardness of about 50 Shore D to about 70 Shore D and an outer cover
layer having a hardness of about 30 Shore D to about 70 Shore
D.
[0068] The present invention is also directed to a golf ball
including a core and a cover, wherein at least a portion of the
golf ball is formed from a composition including a prepolymer and a
curing agent, wherein the prepolymer is formed from a first
prepolymer and a functionalized block copolymer, and wherein the
prepolymer includes an A.sub.x-B.sub.y-A.sub.z block capped by
isocyanate end groups, wherein x, y, and z are independently 1 or
greater. In this aspect of the invention, the functionalized block
copolymer may include at least one functional group selected from
the group consisting of hydroxy groups, amino groups, thiol groups,
epoxy groups, anhydride groups, and combinations thereof. In one
embodiment, the first prepolymer includes an isocyanate and a
polyol. In an alternate embodiment, the first prepolymer includes
an isocyanate and a polyamine. The curing agent may include a
hydroxy-terminated curing agent, an amine-terminated curing agent,
or a mixture thereof.
[0069] In one embodiment, the A.sub.x-B.sub.y-A.sub.z block
includes olefin-diene-olefin. For example, the olefin-diene-olefin
may be styrene-butadiene-styrene. In another embodiment, the
portion of the golf ball formed from the composition of the
invention has a moisture vapor transmission rate of about 0.01 to
about 0.09 g/(m.sup.2.times.day) at 38.degree. C. and 90 percent
relative humidity.
[0070] The present invention further relates to a golf ball
including a core and a cover, wherein the cover is formed from a
composition including a prepolymer and an amine-terminated curing
agent, wherein the prepolymer is the reaction product of a first
prepolymer and a functionalized block copolymer including an
A.sub.x-B.sub.y block, wherein x and y are independently 1 or
greater, and wherein the first prepolymer includes an isocyanate
and at least one of an amine-terminated component or a
hydroxy-terminated component. In one embodiment, the prepolymer
includes the A.sub.x-B.sub.y block capped by isocyanate end groups.
In another embodiment, the A.sub.x-B.sub.y block includes an
olefin-diene block. For example, the A.sub.x-B.sub.y block may
include a styrene-butadiene block. In one embodiment, the cover
includes an inner cover layer and an outer cover layer, wherein the
inner cover layer includes a thermoplastic material, e.g., ionomer
resin. In another embodiment, the functionalized block copolymer
includes at least one functional group selected from the group
consisting of hydroxy groups, amino groups, thiol groups, epoxy
groups, anhydride groups, and combinations thereof.
[0071] The present invention is further directed to a golf ball
including a core, an intermediate layer, and a cover, wherein the
cover is formed from a composition including a prepolymer and a
curing agent, wherein the prepolymer includes a first prepolymer
and a block copolymer having functional groups at each terminal
end, wherein the composition includes a hydrophobic A.sub.x-B.sub.y
block or hydrophobic A.sub.x-B.sub.y-A.sub.z block capped by
isocyanate groups, and wherein x, y, and z are independently 1 or
greater. In one embodiment, the first prepolymer is formed from the
reaction product of an isocyanate and an amine-terminated compound
or a hydroxy-terminated compound. In an alternate embodiment, the
first prepolymer is the reaction product of an isocyanate and an
amine-terminated compound.
[0072] In this aspect of the invention, the curing agent may be
selected from the group consisting of ethylene diamine;
hexamethylene diamine; 1-methyl-2,6-cyclohexyl diamine; 2,2,4- and
2,4,4-trimethyl-1,6-hexanediamine;
4,4'-bis-(sec-butylamino)-dicyclohexylmethane and derivatives
thereof; 1,4-bis-(sec-butylamino)-cyclohexane;
1,2-bis-(sec-butylamino)-cyclohexane; 4,4'-dicyclohexylmethane
diamine; 1,4-cyclohexane-bis-(methylamine);
1,3-cyclohexane-bis-(methylamine); diethylene glycol
bis-(aminopropyl)ether; 2-methylpentamethylene-diamine;
diaminocyclohexane; diethylene triamine; triethylene tetramine;
tetraethylene pentamine; propylene diamine; 1,3-diaminopropane;
dimethylamino propylamine; diethylamino propylamine;
imido-bis-propylamine; monoethanolamine, diethanolamine;
triethanolamine; monoisopropanolamine, diisopropanolamine;
isophoronediamine; 4,4'-methylenebis-(2-chloroaniline);
3,5-dimethylthio-2,4-toluenediamine;
3,5-dimethylthio-2,6-toluenediamine;
3,5-diethylthio-2,4-toluenediamine;
3,5-diethylthio-2,6-toluenediamine;
4,4'-bis-(sec-butylamino)-diphenylmethane and derivatives thereof;
1,4-bis-(sec-butylamino)-benzene; 1,2-bis-(sec-butylamino)-benzene;
N,N'-dialkylamino-diphenylmethane;
trimethyleneglycol-di-p-aminobenzoate;
polytetramethyleneoxide-di-p-aminobenzoate;
4,4'-methylenebis-(3-chloro-2,6-diethyleneaniline);
4,4'-methylenebis-(2,6-diethylaniline); meta-phenylenediamine;
paraphenylenediamine; N,N'-diisopropyl-isophoronediamine;
polyoxypropylene diamine; propylene oxide-based triamine;
3,3'-dimethyl-4,4'-diaminocyclohexylmethane; and mixtures
thereof.
[0073] In this aspect of the invention, the A.sub.x-B.sub.y block
may include a styrene-butadiene block. Likewise, the
A.sub.x-B.sub.y-A.sub.z block may include a
styrene-butadiene-styrene block. In one embodiment, the functional
groups are selected from the group consisting of hydroxy groups,
amino groups, thiol groups, epoxy groups, anhydride groups, and
combinations thereof.
[0074] The present invention is also directed to a method for
forming a golf ball composition including the steps of: forming a
prepolymer including an isocyanate and at least one of a
hydroxy-terminated component or an amine-terminated component;
providing a block copolymer, wherein the block copolymer includes
at least one functional group at a terminal end of the block
copolymer; reacting excess prepolymer with the block copolymer to
form an intermediate prepolymer; chain extending the intermediate
prepolymer with a curing agent to form a composition including a
hydrophobic block capped by isocyanate groups.
[0075] In one embodiment, the hydrophobic block includes an
A.sub.x-B.sub.y block, wherein x and y are independently 1 or
greater, and wherein A includes an olefin and B includes a diene.
In an alternate embodiment, the hydrophobic block includes an
A.sub.x-B.sub.y-A.sub.z block, wherein x and y are independently 1
or greater, and wherein A includes an olefin and B includes a
diene. For example, the olefin may include styrene and the diene
may include butadiene. In addition, the step of forming the
prepolymer may include forming the reaction product of an
isocyanate and an amine-terminated component. The curing agent may
be an amine-terminated curing agent.
[0076] In this aspect of the invention, the step of providing a
block copolymer may further include the steps of: providing a block
copolymer including an A.sub.x-B.sub.y block or
A.sub.x-B.sub.y-A.sub.z block, wherein x, y, and z are
independently 1 or greater; providing a coupling agent including at
least one hydroxy group, amino group, thiol group, epoxy group,
anhydride group, or mixture thereof; functionalizing the block
copolymer with the coupling agent to provide a functionalized block
copolymer.
[0077] The present invention further relates to a method for
forming a golf ball component including the steps of: forming a
prepolymer including an isocyanate and at least one of a
hydroxy-terminated component or an amine-terminated component;
providing a block copolymer including an A.sub.x-B.sub.y block or
an A.sub.x-B.sub.y-A.sub.z block, wherein x, y, and z are
independently 1 or greater, and wherein the block copolymer
includes at least one functional group at a terminal end of the
block copolymer; reacting the prepolymer with the block copolymer
to form the composition; forming the composition into a golf ball
component.
[0078] In one embodiment, the A.sub.x-B.sub.y block includes an
olefin-diene block. For example, the olefin-diene block may be
styrene-butadiene. In an alternate embodiment, the
A.sub.x-B.sub.y-A.sub.z block includes an olefin-diene-olefin
block, e.g., styrene-butadiene-styrene.
[0079] In this aspect of the invention, the step of providing a
block copolymer may further include the steps of: providing a
coupling agent including at least one hydroxy group, amino group,
thiol group, epoxy group, anhydride group, or mixture thereof;
functionalizing the block copolymer with the coupling agent to
provide a functionalized block copolymer.
[0080] In one embodiment, the step of forming a golf ball component
includes providing a core and forming the composition about the
core. In addition, the step of forming the composition about the
core may further include casting the composition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0081] Further features and advantages of the invention can be
ascertained from the following detailed description that is
provided in connection with the drawing(s) described below:
[0082] FIG. 1 is a cross-sectional view of a two-piece golf ball,
wherein the cover is formed from a composition of the
invention;
[0083] FIG. 2 is a cross-sectional view of a multi-component golf
ball, wherein at least the cover is formed from a composition of
the invention;
[0084] FIG. 3 is a cross-sectional view of a multi-component golf
ball, wherein the cover is formed from a composition of the
invention and the intermediate layer is formed from a composition
including a thermoplastic material;
[0085] FIG. 4 is a cross-sectional view of a multi-component golf
ball including a core and a cover, wherein the core is surrounded
by a tensioned elastomeric material and the cover is formed from a
composition of the invention;
[0086] FIG. 5 is a cross-sectional view of a liquid center golf
ball wherein the liquid core is surrounded by a tensioned
elastomeric material and the cover is formed from a composition of
the invention;
[0087] FIG. 6 is a cross-sectional view of a multi-component golf
ball including a core, a thin inner cover layer, and a thin outer
cover layer disposed thereon, wherein the cover is formed from a
composition of the invention;
[0088] FIG. 7 is a cross-sectional view of a multi-component golf
ball including a core, an outer core layer, a thin inner cover
layer, and a thin outer cover layer disposed thereon, wherein the
cover is formed from a composition of the invention;
[0089] FIG. 8 is a cross-sectional view of a multi-component golf
ball including a large core and a thin outer cover layer disposed
thereon, wherein the cover is formed from a composition of the
invention;
[0090] FIG. 9 is a graphical representation of the weight changes
of golf balls subjected to controlled temperature and humidity over
a specified amount of time; and
[0091] FIG. 10 is a graphical representation of the size changes of
golf balls subjected to controlled temperature and humidity over a
specified amount of time.
DETAILED DESCRIPTION OF THE INVENTION
[0092] The present invention contemplates improved light stable and
moisture resistant compositions for use in golf equipment, such as
golf balls, golf clubs, or the like. In particular, the
compositions of the invention preferably include polyurethane-based
block copolymers, polyurea-based block copolymers, or mixtures
thereof and are included in a variety of golf ball constructions,
i.e., one-piece, two-piece, or multilayer balls, as well as golf
club components, e.g., club head inserts.
[0093] The enhanced light stability of the compositions of the
invention enables the production of various golf equipment
components with physical and aerodynamic properties better than or
equal to golf balls incorporating polyurea or polyurethane
compositions without light stable blends.
[0094] Light stability may be accomplished in a variety of ways for
the purposes of this application. For example, the compositions of
the invention may include only saturated components, i.e.,
components substantially free of unsaturated carbon-carbon bonds or
aromatic groups. The term "saturated," as used herein, refers to
compositions having saturated aliphatic and alicyclic polymer
backbones, i.e., with no carbon-carbon double bonds. The
compositions of the invention may also include a light stabilizer
to improve light stability when using aromatic components and are
preferably saturated. In addition, the use of a composition
including a hydrogenated block copolymer enhances the light
stability of the compositions. In particular, the use of
hydrogenated styrene-butadiene-styrene results in enhanced light
stability due to the fact that adding hydrogen causes the double
bond to become a single bond.
[0095] Furthermore, because conventional polyurethane and polyurea
elastomers are prone to absorption of moisture, the present
invention provides novel compositions to improve the water
resistance of golf equipment compositions. For example, the
polyurethane-based and polyurea-based block copolymers of the
present invention provide hydrophobicity, in addition to resiliency
and durability. In addition, when the elastomers of the invention
are based on hydrophobic backbones, the improved moisture
resistance of these compositions result in golf equipment with
improved stability with respect to its resistance to the absorption
of moisture.
[0096] Thus, the improved performance characteristics of the golf
equipment of the present invention demonstrate a distinct benefit
to the golfer by providing golf equipment that exhibits consistent
behavior over a wide range of environmental conditions.
Polyurea-Based Compositions
[0097] Polyurea-based compositions, which are distinctly different
from polyurethane-based compositions, result in desirable
aerodynamic and aesthetic characteristics when used in golf
equipment and ball components. Conventional aromatic
polyurethane/urethane elastomers and polyurethane/urea elastomers
are generally prepared by curing a prepolymer of diisocyanate and
polyol with at least one diol curing agent or at least one diamine
curing agent, respectively. Without being bound to any particular
theory, it is now believed that substitution of the long chain
polyol segment in the polyurethane prepolymer with a long chain
amine-terminated compound to form a polyurea prepolymer, improves
shear, cut, and resiliency, as well as adhesion to other
components.
[0098] As mentioned above, the polyurea-based compositions of the
invention provide improved moisture resistance and light stability.
The polyurea-based compositions of this invention may be formed in
several ways: a) from the reaction product of an isocyanate and
amine-terminated compound prepolymer crosslinked with a curing
agent; b) from the reaction product of an isocyanate and an
amine-functionalized block copolymer; c) from the reaction product
of a polyurea-based prepolymer and an amine-functionalized block
copolymer; and d) by reacting an excess of a polyurea-based
prepolymer and an amine-terminated block copolymer to form an
intermediate prepolymer having the block copolymer capped at each
end with isocyanate groups, which is cured with a curing agent.
[0099] For example, polyurea-based compositions of the invention
may be prepared from at least one isocyanate, at least one
amine-terminated compound based on a hydrophobic backbone, and at
least one diol curing agent or at least one diamine curing agent,
preferably a secondary diamine curing agent. The hydrophobic
backbone provides increased water resistance. In another aspect,
the compositions of the invention include the reaction product of
an isocyanate and an amine-functionalized block copolymer, wherein
the isocyanate is coupled with the block copolymer at the terminal
end. The presence of the rubbery mid-section in the block
copolymer, or a hydrogenated moiety, provides both flexibility and
hydrophobicity to the composition.
[0100] The polyurea-based compositions of the invention may be
formed of only saturated components, which have greater light
stability, or may include one or more unsaturated components and a
light stabilizer. In addition, when the compositions of the
invention are formed using a hydrogenated block copolymer, such as
hydrogenated styrene-butadiene-styrene, adding hydrogen causes the
double bond to become a single bond, which enhances the light
stability.
Compositions of the Invention
[0101] The compositions of the invention may be formed in several
ways. For example, the compositions may be formed from the reaction
product of an isocyanate and a functionalized block copolymer. When
forming a polyurethane-based composition, the functional groups of
the block copolymer are amine groups, whereas the functional groups
are hydroxy groups when forming a polyurethane-based composition.
In addition, the compositions of the present invention may be
formed from the reaction product of a prepolymer, which is based on
an isocyanate and a polyol or amine, and a functionalized block
copolymer. The compositions of the invention may also be formed by
reacting an excess of prepolymer, which is based on an isocyanate
and a polyol or amine, with a functionalized block copolymer to
form an intermediate prepolymer having the block copolymer portion
capped with isocyanate groups at each end, which is then reacted
with a curing agent to form a polyurethane-based or polyurea-based
composition. Finally, the compositions of the invention may be
formed by curing a polyurethane or polyurea prepolymer with an
amine-terminated or hydroxy-terminated curing agent.
[0102] Such novel compositions are advantageous in that the
beneficial properties of the separate polymers are accentuated,
while the detrimental qualities are compensated for, or completely
overcome. For example, a conventional polyurea or polyurethane
composition is moisture sensitive and is not compatible with
non-polar polymer layers, but has a good low temperature and scuff
resistance. On the other hand, conventional block copolymers, such
as styrene-butadiene-styrene (SBS) block copolymers, or their
hydrogenated derivatives, are hydrophobic, but lack resiliency, are
not compatible with polar polymers, and cause severe delamination
when used in golf ball layers. As such, coupling the polyurea
prepolymer or polyurethane prepolymer with an SBS block copolymer
provides the hydrophobicity of the SBS block copolymer and the
scuff resistance of the prepolymer.
[0103] In addition, when a polyurea-block SBS, polyurethane-block
SBS, or derivative thereof, is used in golf equipment according to
the invention, there are several advantages over golf equipment
formed from conventional compositions. For example, golf ball
components formed from a polyurea-block SBS or a polyurethane-block
SBS have improved scuff resistance and resiliency over golf ball
components formed from conventional SBS block copolymers due to the
urea/urethane moiety. Furthermore, the urea and urethane moieties
allow blending with other polar polymers such as polycarbonate,
polyester, polyamide, acid copolymers, ionomers, and the like.
Also, the presence of diene/olefinic hydrocarbon moiety enables
blending with non-polar polymers such as polyethylene,
polypropylene, polystyrene, and the like. As such, the adhesion to
other polar and non-polar layers is improved over golf ball
components formed from conventional compositions. Moreover, the
presence of the butadiene moiety, or hydrogenated moiety, provides
flexibility and hydrophobicity to the golf ball component.
Reacting an Isocyanate and a Functionalized Block Copolymer
[0104] The compositions of the invention may be formed by coupling
an isocyanate with a block copolymer. In particular, block
copolymers can be functionalized at the terminal end with a hydroxy
group or amine group and then reacted with an isocyanate to form a
polyurea-based polymer or a polyurethane-based polymer.
[0105] Suitable block copolymers for use with the present invention
include, but are not limited to, block copolymers having a general
A.sub.x-B.sub.y block or an A.sub.xB.sub.yA.sub.z block, where x,
y, and z represent the chain lengths and are independently 1 or
greater. For example, x can be 2, y can be 1, and z can be 2.
However, each chain length can be the same or different.
[0106] The block copolymer may be an olefin-diene (A-B) block
copolymer, such as styrene-butadiene block copolymer,
ethylene-butadiene block copolymer, and propylene butadiene block
copolymer. In addition, the block copolymer may be an
olefin-diene-olefin (A-B-A) block copolymer, such as
styrene-butadiene-styrene block copolymer (SBS block copolymer),
hydrogenated SBS block copolymer, ethylene-butadiene-ethylene block
copolymer, and propylene-butadiene-propylene block copolymer. In an
alternative embodiment, the block copolymers of the invention may
be acrylic-based, for example, the A in the AB or ABA block may be
acrylate.
[0107] Those of ordinary skill in the art should be well aware of
the general characteristics of block copolymers and the methods for
making them. For example, SBS block copolymer is made up of three
segments, i.e., two end chains of polystyrene and a middle long
chain of polybutadiene, and has the following general
structure:
##STR00006##
where n is the length of the chain, i.e., 1 or greater. Because
polystyrene is a hard plastic, the SBS block copolymer is durable.
And, SBS block copolymer has elastomeric properties without being
crosslinked, which is different from most rubbers. In addition, the
polystyrene chains have a tendency to cluster together so that when
one polystyrene group of an SBS molecule joins a cluster, and the
other polystyrene group on the same SBS molecule joins another
cluster, the different clusters become coupled together with the
elastic polybutadiene chains. This gives the SBS block copolymer
the ability to retain its shape after being stretched.
[0108] Living anionic polymerization, i.e., polymerization without
any termination reactions, may be used to make the SBS block
copolymers of the invention. The general polymerization process is
as follows:
##STR00007##
where n is the chain length, i.e., 1 or greater, and wherein R is a
butyl group.
[0109] Because the SBS block copolymer, or hydrogenated SBS, does
not have functional groups, a coupling agent is needed to
functionalize the block copolymer so that it can be reacted with
the isocyanate. The coupling agent may be based on the following
general structure:
R-R.sub.1-R
where R.sub.1 is any alkyl group including single bonds, double
bonds, triple bonds, or a combination thereof and where the
terminal groups (R) may be hydroxy groups, amino groups, thiol
groups, epoxy groups, anhydride groups, or mixtures thereof. In one
embodiment, R.sub.1 has about 1 to about 36 carbon atoms,
preferably about 1 to about 20 carbons atoms, and more preferably
about 1 to about 18 carbon atoms.
[0110] Suitable hydroxy-terminated compounds that may be used as
coupling agents according to the invention include, but are not
limited to, the following:
##STR00008##
[0111] As generally addressed above, the coupling agent can also be
monoamine and mono-hydroxy-terminated compounds with the following
general structure:
H.sub.2N--R.sub.1--OH
where R.sub.1 can be any alkyl group. In one embodiment, R.sub.1
has about 1 to about 20 carbon atoms, preferably about 2 to about
20 carbons atoms.
[0112] Examples of coupling agents suitable for use with the
present invention include, but are not limited to, 1-amino-ethenol;
1-amino-2-propen-1-ol; 1-amino-1-propen-2-ol;
1-amino-4-penten-2-ol; 1-amino-4-hexen-3-ol; 1-amino-3-penten-2-ol;
1-amino-1-hepten-2-ol; 1-amino-3-nonen-2-ol; 2-amino-ethenol;
2-amino-3-buten-1-ol; 2-amino-4-pentene-1-ol; 2-amino-5-hexen-1-ol;
2-amino-3,14-octadecadien-1-ol; 2-amino-3,8-octadecadien-1-ol;
2-amino-3,9-octadecadien-1-ol; 8-amino-1-octen-4-ol;
4-amino-2-buten-2-ol; 4-amino-1-penten-3-ol;
4-amino-1,5-hexadiene-3-ol; 4-amino-2,5-hexadiene-1-ol; ethynol;
4-amino-2-butyn-1-ol; 1-amino-1-hydroxy-2-butenyl;
1-amino-3-pentyn-2-ol; 1-amino-3-decyn-2-ol; and mixtures
thereof.
[0113] The alkyl group in the coupling agent may contain single
bonds, double bonds, or triple bonds. In one embodiment, the alkyl
group includes single bonds and double bonds. In another
embodiment, the alkyl group includes only single bonds. For
example, saturated coupling agents suitable for use with the
present invention include, but are not limited to, 1-amino-ethanol,
2-amino-propan-1-ol, 2-amino-butan-4-ol, 3-amino-hexan-4-ol;
4-amino-pentan-1-ol, and mixtures thereof.
Reacting a Prepolymer and a Functionalized Block Copolymer
[0114] In another aspect of the invention, the compositions of the
invention may be formed by reacting a polyurethane or polyurea
prepolymer with a functionalized block copolymer. The
functionalized block copolymer may be any of the block copolymers
discussed above. The mechanism for the reaction is similar to above
in that the functional groups of the block copolymer (obtained by
using a coupling agent with the block copolymer) react with the NCO
groups of the isocyanate in the prepolymer.
[0115] As briefly mentioned above, the prepolymer used in this
aspect of the invention may be a polyurethane prepolymer or a
polyurea prepolymer. The polyurea prepolymer is the reaction
product of an amine-terminated component and an isocyanate, whereas
the polyurethane prepolymer is the reaction product of a
hydroxy-terminated component and an isocyanate. The particular
components of the prepolymers will be discussed in greater detail
below.
[0116] Because the main difference between the polyurea prepolymer
and the polyurethane prepolymer is the amine-terminated
component/polyol component, the isocyanates discussed are intended
to be used in either type of prepolymer.
[0117] Any isocyanate available to one of ordinary skill in the art
is suitable for use in the prepolymers according to the invention.
Isocyanates for use with the present invention include aliphatic,
cycloaliphatic, aromatic aliphatic, aromatic, any derivatives
thereof, and combinations of these compounds having two or more
isocyanate (NCO) groups per molecule. As used herein, aromatic
aliphatic compounds should be understood as those containing an
aromatic ring, wherein the isocyanate group is not directly bonded
to the ring. One example of an aromatic aliphatic compound is a
tetramethylene diisocyanate (TMXDI).
[0118] The isocyanates may be organic polyisocyanate-terminated
prepolymers, low free isocyanate prepolymer, and mixtures thereof.
The isocyanate-containing reactable component may also include any
isocyanate-functional monomer, dimer, trimer, or polymeric adduct
thereof, prepolymer, quasi-prepolymer, or mixtures thereof.
Isocyanate-functional compounds may include monoisocyanates or
polyisocyanates that include any isocyanate functionality of two or
more.
[0119] Suitable isocyanate-containing components include
diisocyanates having the generic structure:
O.dbd.C.dbd.N--R--N.dbd.C.dbd.O, where R is preferably a cyclic,
aromatic, or linear or branched hydrocarbon moiety containing from
about 1 to about 20 carbon atoms. The isocyanate may also contain
one or more cyclic groups or one or more phenyl groups. When
multiple cyclic or aromatic groups are present, linear and/or
branched hydrocarbons containing from about 1 to about 10 carbon
atoms can be present as spacers between the cyclic or aromatic
groups. In some cases, the cyclic or aromatic group(s) may be
substituted at the 2-, 3-, and/or 4-positions, or at the ortho-,
meta-, and/or para-positions, respectively. Substituted groups may
include, but are not limited to, halogens, primary, secondary, or
tertiary hydrocarbon groups, or a mixture thereof.
[0120] Examples of isocyanates that can be used with the present
invention include, but are not limited to, substituted and isomeric
mixtures including 2,2'-, 2,4'-, and 4,4'-diphenylmethane
diisocyanate (MDI); 3,3'-dimethyl-4,4'-biphenylene diisocyanate
(TODI); toluene diisocyanate (TDI); polymeric MDI;
carbodiimide-modified liquid 4,4'-diphenylmethane diisocyanate;
para-phenylene diisocyanate (PPDI); meta-phenylene diisocyanate
(MPDI); triphenyl methane-4,4'- and triphenyl
methane-4,4''-triisocyanate; naphthylene-1,5-diisocyanate; 2,4'-,
4,4'-, and 2,2-biphenyl diisocyanate; polyphenylene polymethylene
polyisocyanate (PMDI) (also known as polymeric PMDI); mixtures of
MDI and PMDI; mixtures of PMDI and TDI; ethylene diisocyanate;
propylene-1,2-diisocyanate; tetramethylene-1,2-diisocyanate;
tetramethylene-1,3-diisocyanate; tetramethylene-1,4-diisocyanate;
1,6-hexamethylene diisocyanate (HDI); octamethylene diisocyanate;
decamethylene diisocyanate; 2,2,4-trimethylhexamethylene
diisocyanate; 2,4,4-trimethylhexamethylene diisocyanate;
dodecane-1,12-diisocyanate; dicyclohexylmethane diisocyanate;
cyclobutane-1,3-diisocyanate; cyclohexane-1,2-diisocyanate;
cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate;
methylcyclohexylene diisocyanate (HTDI); 2,4-methylcyclohexane
diisocyanate; 2,6-methylcyclohexane diisocyanate; 4,4'-dicyclohexyl
diisocyanate; 2,4'-dicyclohexyl diisocyanate; 1,3,5-cyclohexane
triisocyanate; isocyanatomethylcyclohexane isocyanate;
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane;
isocyanatoethylcyclohexane isocyanate;
bis(isocyanatomethyl)-cyclohexane diisocyanate;
4,4'-bis(isocyanatomethyl) dicyclohexane;
2,4'-bis(isocyanatomethyl) dicyclohexane; isophorone diisocyanate
(IPDI); triisocyanate of HDI; triisocyanate of
2,2,4-trimethyl-1,6-hexane diisocyanate (TMDI);
4,4'-dicyclohexylmethane diisocyanate (H).sub.2MDI);
2,4-hexahydrotoluene diisocyanate; 2,6-hexahydrotoluene
diisocyanate; 1,2-, 1,3-, and 1,4-phenylene diisocyanate; aromatic
aliphatic isocyanate, such as 1,2-, 1,3-, and 1,4-xylene
diisocyanate; meta-tetramethylxylene diisocyanate (m-TMXDI);
para-tetramethylxylene diisocyanate (p-TMXDI); trimerized
isocyanurate of any polyisocyanate, such as isocyanurate of toluene
diisocyanate, trimer of diphenylmethane diisocyanate, trimer of
tetramethylxylene diisocyanate, isocyanurate of hexamethylene
diisocyanate, and mixtures thereof; dimerized uretdione of any
polyisocyanate, such as uretdione of toluene diisocyanate,
uretdione of hexamethylene diisocyanate, and mixtures thereof;
modified polyisocyanate derived from the above isocyanates and
polyisocyanates; and mixtures thereof.
[0121] When forming a saturated composition, the following
saturated isocyanates are preferably used: ethylene diisocyanate;
propylene-1,2-diisocyanate; tetramethylene diisocyanate;
tetramethylene-1,4-diisocyanate; 1,6-hexamethylene diisocyanate
(HDI); octamethylene diisocyanate; decamethylene diisocyanate;
2,2,4-trimethylhexamethylene diisocyanate;
2,4,4-trimethylhexamethylene diisocyanate;
dodecane-1,12-diisocyanate; dicyclohexylmethane diisocyanate;
cyclobutane-1,3-diisocyanate; cyclohexane-1,2-diisocyanate;
cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate;
methylcyclohexylene diisocyanate (HTDI); 2,4-methylcyclohexane
diisocyanate; 2,6-methylcyclohexane diisocyanate; 4,4'-dicyclohexyl
diisocyanate; 2,4'-dicyclohexyl diisocyanate; 1,3,5-cyclohexane
triisocyanate; isocyanatomethylcyclohexane isocyanate;
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane;
isocyanatoethylcyclohexane isocyanate;
bis(isocyanatomethyl)-cyclohexane diisocyanate;
4,4'-bis(isocyanatomethyl) dicyclohexane;
2,4'-bis(isocyanatomethyl) dicyclohexane; isophorone diisocyanate
(IPDI); triisocyanate of HDI; triisocyanate of
2,2,4-trimethyl-1,6-hexane diisocyanate (TMDI);
4,4'-dicyclohexylmethane diisocyanate (H.sub.12MDI);
2,4-hexahydrotoluene diisocyanate; 2,6-hexahydrotoluene
diisocyanate; and mixtures thereof. Aromatic aliphatic isocyanates
may also be used to form light stable materials. Examples of such
isocyanates include 1,2-, 1,3-, and 1,4-xylene diisocyanate;
meta-tetramethylxylene diisocyanate (m-TMXDI);
para-tetramethylxylene diisocyanate (p-TMXDI); trimerized
isocyanurate of any polyisocyanate, such as isocyanurate of toluene
diisocyanate, trimer of diphenylmethane diisocyanate, trimer of
tetramethylxylene diisocyanate, isocyanurate of hexamethylene
diisocyanate, and mixtures thereof; dimerized uretdione of any
polyisocyanate, such as uretdione of toluene diisocyanate,
uretdione of hexamethylene diisocyanate, and mixtures thereof; a
modified polyisocyanate derived from the above isocyanates and
polyisocyanates; and mixtures thereof. In addition, the aromatic
aliphatic isocyanates may be mixed with any of the saturated
isocyanates listed above for the purposes of this invention.
[0122] The number of unreacted NCO groups in the polyurea-based
composition may be varied to control such factors as the speed of
the reaction, the resultant hardness of the composition, and the
like. For example, as the weight percent of unreacted isocyanate
groups increases, the hardness also increases in a somewhat linear
fashion. Thus, when the NCO content is about 10.5 weight percent,
the hardness may be less than about 55 Shore A, whereas once the
NCO content increases about 15 weight percent, the hardness is
greater than about 80 Shore A.
[0123] In one embodiment, the number of unreacted NCO groups in the
polyurea-based composition may be less than about 14 percent. In
one embodiment, the polyurea-based composition has from about 5
percent to about 11 percent unreacted NCO groups, and even more
preferably has from about 6 to about 9.5 percent unreacted NCO
groups. In one embodiment, the percentage of unreacted NCO groups
is about 3 percent to about 9 percent. Alternatively, the
percentage of unreacted NCO groups may be about 7.5 percent or
less, and more preferably, about 7 percent or less. In another
embodiment, the unreacted NCO content is from about 2.5 percent to
about 7.5 percent, and more preferably from about 4 percent to
about 6.5 percent.
[0124] When formed, the prepolymers may contain about 10 percent to
about 20 percent by weight of the prepolymer of free isocyanate
monomer. Thus, in one embodiment, the prepolymer may be stripped of
the free isocyanate monomer. For example, after stripping, the
prepolymer may contain about 1 percent or less free isocyanate
monomer. In another embodiment, the prepolymer contains about 0.5
percent by weight or less of free isocyanate monomer.
[0125] Any amine-terminated compound available to one of ordinary
skill in the art is suitable for use in the polyurea prepolymer.
The amine-terminated compound may include amine-terminated
hydrocarbons, amine-terminated polyethers, amine-terminated
polyesters, amine-terminated polycarbonates, amine-terminated
polycaprolactones, and mixtures thereof. The amine-terminated
segments may be in the form of a primary amine (NH.sub.2) or a
secondary amine (NHR).
[0126] The molecular weight of the amine-terminated compound for
use in the invention may range from about 100 to about 10,000. As
used herein, the term "about" is used in connection with one or
more numbers or numerical ranges, should be understood to refer to
all such numbers, including all numbers in a range. In one
embodiment, the amine-terminated compound is about 500 or greater,
preferably about 1000 or greater, and even more preferably about
2000 or greater. In another embodiment, the amine-terminated
compound molecular weight is about 8000 or less, preferably about
4,000 or less, and more preferably about 3,000 or less. For
example, in one embodiment, the molecular weight of the
amine-terminated compound is about 1000 to about 4000. Because
lower molecular weight polyether amines may be prone to forming
solid polyureas, a higher molecular weight oligomer may be used to
avoid solid formation.
[0127] In one embodiment, the amine-terminated compound includes
amine-terminated hydrocarbons having the following generic
structures:
##STR00009##
where x is the chain length, i.e., 1 or greater, n is preferably
about 1 to about 12, and R is any alkyl group having from about 1
to about 20 carbon atoms, preferably about 1 to about 12 carbon
atoms, a phenyl group, a cyclic group, or mixture thereof.
[0128] The amine-terminated compound may also includes
amine-terminated polyethers having following generic
structures:
##STR00010##
where x is the chain length, i.e., 1 or greater, n is preferably
about 1 to about 12, and R is any alkyl group having from about 1
to about 20 carbon atoms, preferably about 1 to about 12 carbon
atoms, a phenyl group, a cyclic group, or mixture thereof. One
example of an amine-terminated polyether is a polyether amine. As
used herein, "polyether amine" refers to a polyoxyalkyleneamine
containing primary amino groups attached to the terminus of a
polyether backbone. Due to the rapid reaction of isocyanate and
amine, and the insolubility of many urea products, however, the
selection of diamines and polyether amines is limited to those
allowing the successful formation of the polyurea prepolymers. In
one embodiment, the polyether backbone is based on tetramethylene,
propylene, ethylene, trimethylolpropane, glycerin, and mixtures
thereof.
[0129] In one embodiment, the polyether amine has the generic
structure:
##STR00011##
wherein the repeating unit x has a value ranging from about 1 to
about 70, R is any alkyl group having from about 1 to about 20
carbon atoms, preferably about 1 to about 12 carbon atoms, a phenyl
group, a cyclic group, or mixture thereof, and R.sub.3 is a
hydrogen, methyl group, or a mixture thereof. Even more preferably,
the repeating unit may be from about 5 to about 50, and even more
preferably is from about 12 to about 35.
[0130] In another embodiment, the polyether amine has the generic
structure:
##STR00012##
wherein the repeating units x and z have combined values from about
3.6 to about 8 and the repeating unit y has a value ranging from
about 9 to about 50, R is an alkyl group having about 1 to about 20
carbons, a phenyl group, a cyclic group, or mixtures thereof,
R.sub.1 is --(CH.sub.2).sub.a--, wherein "a" may be a repeating
unit ranging from about 1 to about 10, a phenylene group, a cyclic
group, or mixtures thereof, and R.sub.3 is a hydrogen, methyl
group, or a mixture thereof.
[0131] In yet another embodiment, the polyether amine has the
generic structure:
H.sub.2N--(R.sub.1) --O--(R.sub.1) --O--(R.sub.1)NH.sub.2;
H.sub.2N--(R.sub.1)O--(R.sub.1)--O--(R.sub.1)--NHR; or
RHN--(R.sub.1)--O--(R.sub.1)--O--(R.sub.1)--NHR
wherein R is an alkyl group having about 1 to about 20 carbons,
phenyl groups, cyclic groups, or mixtures thereof, and wherein
R.sub.1 is --(CH.sub.2).sub.3--, wherein "a" may be a repeating
unit ranging from about 1 to about 10, a phenylene group, a cyclic
group, or mixtures thereof.
[0132] Suitable polyether amines include, but are not limited to,
methyldiethanolamine; polyoxyalkylenediamines such as,
polytetramethylene ether diamines, polyoxypropylenetriamine,
polyoxyethylene diamines, and polyoxypropylene diamines;
poly(ethylene oxide capped oxypropylene) ether diamines; propylene
oxide-based triamines; triethyleneglycoldiamines;
trimethylolpropane-based triamines; glycerin-based triamines; and
mixtures thereof. In one embodiment, the polyether amine used to
form the prepolymer is Jeffamine.RTM. D2000 (manufactured by
Huntsman Corporation of Austin, Tex.).
[0133] The molecular weight of the polyether amine for use in the
invention may range from about 100 to about 5000. In one
embodiment, the polyether amine molecular weight is about 200 or
greater, preferably about 230 or greater. In another embodiment,
the molecular weight of the polyether amine is about 4000 or less.
In yet another embodiment, the molecular weight of the polyether
amine is about 600 or greater. In still another embodiment, the
molecular weight of the polyether amine is about 3000 or less. In
yet another embodiment, the molecular weight of the polyether amine
is between about 1000 and about 4000, preferably 1000 to about
4000, and more preferably is between about 1500 to about 2500.
Because lower molecular weight polyether amines may be prone to
forming solid polyureas during prepolymer preparation, a higher
molecular weight oligomer, such as Jeffamine.RTM. D2000, is
preferred.
[0134] In addition, the amine-terminated compound may include
amine-terminated polyesters having the generic structures:
##STR00013##
where x is the chain length, i.e., 1 or greater, preferably about 1
to about 20, R is any alkyl group having from about 1 to about 20
carbon atoms, preferably about 1 to about 12 carbon atoms, a phenyl
group, a cyclic group, or mixture thereof, and R.sub.1 and R.sub.2
are straight or branched hydrocarbon chains, e.g., alkyl or aryl
chains.
[0135] Copolymers of polycaprolactone and polyamines may also be
used to form the polyurea prepolymers of the present invention.
These copolymers include, but are not limited to,
bis(2-aminoethyl)ether initiated polycaprolactone,
2-(2-aminoethylamino) ethanol, 2-2(aminoethylamino) ethanol,
polyoxyethylene diamine initiated polycaprolactone, propylene
diamine initiated polycaprolactone, polyoxypropylene diamine
initiated polycaprolactone, 1,4-butanediamine initiated
polycaprolactone, trimethylolpropane-based triamine initiated
polycaprolactone, neopentyl diamine initiated polycaprolactone,
hexanediamine initiated polycaprolactone, polytetramethylene ether
diamine initiated polycaprolactone, and mixtures thereof. In
addition, polycaprolactone polyamines having the following
structures may be useful in forming the polyurea prepolymers of the
present invention:
##STR00014##
where x is the chain length, i.e., 1 or greater, preferably about 1
to about 20, R is one of an alkyl group having from about 1 to
about 20 carbons, preferably about 1 to about 12 carbons, a phenyl
group, or a cyclic group, and R.sub.1 is a straight or branched
hydrocarbon chain including about 1 to about 20 carbons.
##STR00015##
where x is the chain length, i.e., 1 or greater, preferably about 1
to about 20, R is one of an alkyl group having from about 1 to
about 20 carbons, preferably about 1 to about 12 carbons, a phenyl
group, or a cyclic group, and R.sub.1 is a straight or branched
hydrocarbon chain including about 1 to about 20 carbons.
[0136] In another embodiment, the amine-terminated compound may be
an amine-terminated polycarbonate having one of the following
generic structures:
##STR00016##
where x is the chain length, which preferably ranges from about 1
to about 20, R is one of an alkyl group having from about 1 to
about 20 carbons, preferably about 1 to about 12 carbons, a phenyl
group, or a cyclic group, and R.sub.1 is a straight chain
hydrocarbon or predominantly bisphenol A units or derivatives
thereof.
[0137] Amine-terminated polyamides may also be reacted with the
isocyanate component to form the polyurea prepolymer component of
the present invention. Suitable amine-terminated polyamides
include, but are not limited to, those having following
structures:
##STR00017##
where x is the chain length, i.e., about 1 or greater, R is one of
an alkyl group having from about 1 to about 20 carbons, preferably
about 1 to about 12 carbons, a phenyl group, or a cyclic group,
R.sub.1 is an alkyl group having about 1 to about 12 carbon atoms,
a phenyl group, or a cyclic group, and R.sub.2 is an alkyl group
having about 1 to about 12 carbon atoms (straight or branched), a
phenyl group, or a cyclic group.
[0138] Additional amine-terminated compounds may also be useful in
forming the polyurea prepolymers of the present invention include,
but are not limited to, poly(acrylonitrile-co-butadiene);
poly(1,4-butanediol) bis(4-aminobenzoate) in liquid or waxy solid
form; linear and branched polyethylenimine; low and high molecular
weight polyethylenimine having an average molecular weight of about
500 to about 30,000; poly(propylene glycol) bis(2-aminopropyl
ether) having an average molecular weight of about 200 to about
5,000; polytetrahydrofuran bis(3-aminopropyl) terminated having an
average molecular weight of about 200 to about 2000; and mixtures
thereof, all of which are available from Aldrich of Milwaukee,
Wis.
[0139] Thus, in one embodiment, the polyurea prepolymer includes a
poly(acrylonitrile-co-butadiene) having one of the following
structures:
##STR00018##
wherein x and y are chain lengths, i.e., greater than about 1, R is
any alkyl group having from about 1 to about 20 carbon atoms,
preferably about 1 to about 12 carbon atoms, a phenyl group, a
cyclic group, or mixture thereof, R.sub.1 is a hydrogen, methyl
group, cyano group, phenyl group, or a mixture thereof, and R.sub.1
is a hydrogen, a methyl group, chloride, or a mixture thereof. In
one embodiment, the y:x ratio is about 82:18 to about 90:10. In
other words, the poly(acrylonitrile-co-butadiene) may have from
about 10 percent to about 18 percent acrylonitrile by weight.
[0140] In another embodiment, the polyurea prepolymer includes a
poly(1,4-butanediol) bis(4-aminobenzoate) having one of the
following structures:
##STR00019##
where x and n are chain lengths, i.e., 1 or greater, and n is
preferably about 1 to about 12, R and R.sub.1 are linear or
branched hydrocarbon chains, an alkyl group having from about 1 to
about 20 carbons, preferably about 1 to about 12 carbons, a phenyl
group, a cyclic group, or mixtures thereof, and R.sub.2 is a
hydrogen, a methyl group, or a mixture thereof. In one embodiment,
R.sub.1 is phenyl, R.sub.2 is hydrogen, and n is about 2.
[0141] In yet another embodiment, the polyurea prepolymer includes
at least one linear or branched polyethyleneimine having one of the
following structures:
##STR00020##
wherein x and y are chain lengths, i.e., greater than about 1, R is
any alkyl group having from about 1 to about 20 carbon atoms,
preferably about 1 to about 12 carbon atoms, a phenyl group, a
cyclic group, or mixture thereof, and R.sub.1 is a hydrogen, methyl
group, or a mixture thereof. In one embodiment, R.sub.1 is
hydrogen. In another embodiment, the polyurea prepolymer includes a
mixture of linear and branched polyethyleneimines.
[0142] In still another embodiment, the polyurea prepolymer of the
present invention includes a polytetrahydrofuran bis(3-aminopropyl)
terminated compound having one of the following structures:
##STR00021##
where m and n are chain lengths, i.e., 1 or greater, n is
preferably about 1 to about 12 and m is preferably about 1 to about
6, R is any one alkyl group having from about 1 to about 20
carbons, preferably about 1 to about 12 carbons, a phenyl group, a
cyclic group, or mixtures thereof, and R.sub.1 and R.sub.2 are
hydrogen, methyl groups, or mixtures thereof. In one embodiment,
both R.sub.1 and R.sub.2 are hydrogen and both m and n are about
2.
[0143] In addition, diamines and triamines may be used with an
isocyanate to form the polyurea prepolymer of the present
invention. In one embodiment, aromatic diamines may be used when an
ultraviolet stabilizer or whitening agent is intended to be
incorporated during postprocessing. U.S. Pat. No. 5,484,870
provides suitable aromatic diamines suitable for use with the
present invention, the entire disclosure of which is incorporated
by reference herein. For example, useful aromatic polyamines
include polymethylene-di-p-aminobenzoates,
polyethyleneglycol-bis(4-aminobenzoate), polytetramethylene
etherglycol-di-p-aminobenzoate,
polypropyleneglycol-di-p-aminobenzoate, and mixtures thereof. In
addition, triamines that may be used in forming the prepolymer of
the invention include N,N,N',N'-tetramethyl-ethylenediamine,
1,4-diazobicyclo(2,2,2)-octane,
N-methyl-N'-dimethylaminoethylpiperazine, N,N-dimethylbenzylamine,
bis-(N,N-diethylaminoethyl)-adipate, N,N-diethylbenzylamine,
pentamethyldiethylenetriamine, N,N-dimethylclyclohexylamine,
N,N,N',N'-tetramethyl-1,3-butanediamine,
N,N-dimethyl-beta-phenylethylamine, 1,2-dimethylimidazole, and
2-methylimidazole.
[0144] The amine-terminated compound may also be blended with
additional polyols, as discussed below with respect to the
polyurethane prepolymers of the invention, to formulate copolymers
that are reacted with excess isocyanate to form the polyurea
prepolymer. Once a polyol is used, however, the excess isocyanate
in the polyurea prepolymer reacts with the hydroxyl groups in the
polyol and forms urethane linkages, which results in a composition
that is no longer pure polyurea, but instead a polyurea/urethane
composition. Such a composition is distinct from a polyurea
composition including only isocyanate, an amine-terminated
compound, and a curing agent.
[0145] Furthermore, by using an amine-terminated component based on
a hydrophobic segment, the polyurea-based compositions of the
invention may be more water resistant than those polyurea
compositions formed with an amine-terminated hydrophilic segment.
Thus, in one embodiment, the amine-terminated compound includes a
hydrophobic backbone, e.g., an unsaturated or saturated
hydrocarbon-based amine-terminated compound. One example of an
amine-terminated hydrocarbon is an amine-terminated
polybutadiene.
[0146] As briefly mentioned above, a polyurethane prepolymer,
according to the present invention, is the reaction product of a
polyol and an isocyanate. Any polyol available to one of ordinary
skill in the art is suitable for use in the polyurethane
prepolymer. Exemplary polyols include, but are not limited to,
polyether polyols, polycaprolactone polyols, polyester polyols,
polycarbonate polyols, hydrocarbon polyols, and mixtures thereof.
Both saturated and unsaturated polyols are suitable for use with
the present invention.
[0147] Suitable polyether polyols for use in the present invention
include, but are not limited to, polytetramethylene ether glycol
(PTMEG); copolymer of polytetramethylene ether glycol and
2-methyl-1,4-butane diol (PTG-L); poly(oxyethylene) glycol;
poly(oxypropylene) glycol; ethylene oxide capped (polyoxypropylene)
glycol; poly(oxypropylene oxyethylene) glycol; and mixtures
thereof.
[0148] Suitable polycaprolactone polyols include, but not limited
to, diethylene glycol initiated polycaprolactone; propylene glycol
initiated polycaprolactone; 1,4-butanediol initiated
polycaprolactone; trimethylol propane initiated polycaprolactone;
neopentyl glycol initiated polycaprolactone; 1,6-hexanediol
initiated polycaprolactone; polytetramethylene ether glycol (PTMEG)
initiated polycaprolactone; ethylene glycol initiated
polycaprolactone; dipropylene glycol initiated polycaprolactone;
and mixtures thereof.
[0149] Suitable polyester polyols include, but not limited to,
polyethylene adipate glycol; polyethylene propylene adipate glycol;
polybutylene adipate glycol; polyethylene butylene adipate glycol;
polyhexamethylene adipate glycol; polyhexamethylene butylene
adipate glycol; ortho-phthalate-1,6-hexanediol polyester polyol;
polyethylene terephthalate polyester polyols; and mixtures
thereof.
[0150] Examples of polycarbonate polyols that may be used with the
present invention include, but is not limited to, poly(phthalate
carbonate) glycol, poly(hexamethylene carbonate) glycol,
polycarbonate polyols containing bisphenol A, and mixtures
thereof.
[0151] Hydrocarbon polyols include, but not limited to,
hydroxy-terminated liquid isoprene rubber (LIR), hydroxy-terminated
polybutadiene polyol, hydroxy-terminated polyolefin polyols,
hydroxy-terminated hydrocarbon polyols, and mixtures thereof.
[0152] Other polyols that may be used to form the prepolymer of the
invention include, but not limited to, glycerols; castor oil and
its derivatives; Polytail H; Polytail HA; Kraton polyols; acrylic
polyols; acid functionalized polyols based on a carboxylic,
sulfonic, or phosphoric acid group; dimer alcohols converted from
the saturated dimerized fatty acid; and mixtures thereof.
[0153] By using polyols based on a hydrophobic backbone, the
polyurethane compositions of the invention may be more water
resistant than those polyurethane compositions having polyols
without a hydrophobic backbone. Some non-limiting examples of
polyols based on a hydrophobic backbone include hydrocarbon
polyols, hydroxy-terminated polybutadiene polyols, polyethers,
polycaprolactones, and polyesters.
[0154] Once formed the polyurea prepolymer or polyurethane
prepolymer may be reacted with a functionalized block copolymer.
For example, a polyurea prepolymer formed from an isocyanate and a
amine-terminated component may be reacted with a functionalized
olefinic block copolymer having the general structure of AB block
copolymer or ABA block copolymer such that the functional groups of
the block copolymer react with the NCO groups of the
prepolymer.
Reacting a Prepolymer and a Functionalized Block Copolymer and
Curing Agent
[0155] The compositions of the invention may also be formed using
the functionalized block copolymers and prepolymer discussed above
to form an intermediate prepolymer, which is then cured with a
curing agent. For example, excess prepolymer is reacted with a
block copolymer having functional groups to form an intermediate
prepolymer that has the block inside with the NCO groups on the
ends. The polyurea-based composition or polyurethane-based
composition is then formed by chain extending the intermediate
prepolymer with a single curing agent or a blend of curing agents.
The curing agent may be hydroxy-terminated, amine-terminated, or a
combination thereof. Both types of curing agents, i.e.,
hydroxy-terminated and amine curatives, may include one or more
saturated, unsaturated, aromatic, and cyclic groups. Additionally,
the hydroxy-terminated and amine curatives may include one or more
halogen groups.
[0156] The type of curing agent used, however, ultimately
determines whether the composition of the invention is
polyurea/urea, polyurea/urethane, polyurethane/urethane or
polyurethane/urea. For example, when a hydroxy-terminated curing
agent is reacted with a polyurea prepolymer of the present
invention, the excess isocyanate in the polyurea prepolymer reacts
with the hydroxyl groups in the curing agent and forms urethane
linkages, which results in a composition that is no longer pure
polyurea, but instead a polyurea/urethane composition. In addition,
a polyurethane prepolymer cured with a hydroxy-terminated curing
agent is polyurethane/urethane because any excess isocyanate groups
will react with the hydroxyl groups of the curing agent to create
more urethane linkages. And, if an amine-terminated curing agent is
used with the polyurethane prepolymer, the excess isocyanate groups
will react with the amine groups of the amine-terminated curing
agent to create urea linkages resulting in polyurethane/urea
composition.
[0157] Thus, for the purposes of the present invention, a pure
polyurea composition, i.e., a polyurea/urea, contains only urea
linkages having the following general structure:
##STR00022##
where x is the chain length, i.e., about 1 or greater, and R and
R.sub.1 are straight chain or branched hydrocarbon chain having
about 1 to about 20 carbons. On the other hand, a
polyurethane/urethane composition contains only urethane linkages,
wherein the urethane linkages have the following general
structure:
##STR00023##
where x is the chain length, i.e., about 1 or greater, and R and
R.sub.1 are straight chain or branched hydrocarbon chain having
about 1 to about 20 carbons. Likewise, a polyurea/urethane
composition or polyurethane/urea composition contains both urethane
and urea linkages.
[0158] Thus, the intermediate prepolymers discussed above may be
cured with an amine-terminated component. For example, when the
compositions of the invention are polyurea-based, the intermediate
prepolymer is formed by 1) forming a polyurea prepolymer from an
isocyanate and an amine-terminated component, 2) reacting an excess
of the polyurea prepolymer with a functionalized block copolymer to
form an intermediate prepolymer having the block inside of two NCO
groups, and 3) chain extending the intermediate prepolymer with an
amine-terminated curing agent. When forming a polyurea-based
composition, the amine-terminated curing agent is preferably a
secondary diamine curing agent so that the composition contains
only urea linkages.
[0159] Suitable amine-terminated curing agents include, but are not
limited to, ethylene diamine; hexamethylene diamine;
1-methyl-2,6-cyclohexyl diamine; 2,2,4- and
2,4,4-trimethyl-1,6-hexanediamine;
4,4'-bis-(sec-butylamino)-dicyclohexylmethane and derivatives
thereof; 1,4-bis-(sec-butylamino)-cyclohexane;
1,2-bis-(sec-butylamino)-cyclohexane; 4,4'-dicyclohexylmethane
diamine; 1,4-cyclohexane-bis-(methylamine);
1,3-cyclohexane-bis-(methylamine), isomers, and mixtures thereof;
diethylene glycol bis-(aminopropyl)ether;
2-methylpentamethylene-diamine; diaminocyclohexane, isomers, and
mixtures thereof; diethylene triamine; triethylene tetramine;
tetraethylene pentamine; propylene diamine; 1,3-diaminopropane;
dimethylamino propylamine; diethylamino propylamine;
imido-bis-(propylamine); monoethanolamine, diethanolamine;
triethanolamine; monoisopropanolamine, diisopropanolamine;
isophoronediamine; 4,4'-methylenebis-(2-chloroaniline);
3,5-dimethylthio-2,4-toluenediamine;
3,5-dimethylthio-2,6-toluenediamine;
3,5-diethylthio-2,4-toluenediamine;
3,5-diethylthio-2,6-toluenediamine;
4,4'-bis-(sec-butylamino)-diphenylmethane and derivatives thereof,
1,4-bis-(sec-butylamino)-benzene; 1,2-bis-(sec-butylamino)-benzene;
N,N'-dialkylamino-diphenylmethane;
trimethyleneglycol-di-p-aminobenzoate;
polytetramethyleneoxide-di-p-aminobenzoate;
4,4'-methylenebis-(3-chloro-2,6-diethyleneaniline);
4,4'-methylenebis-(2,6-diethylaniline); meta-phenylenediamine;
paraphenylenediamine; N,N'-diisopropyl-isophoronediamine;
polyoxypropylene diamine; propylene oxide-based triamine;
3,3'-dimethyl-4,4'-diaminocyclohexylmethane; and mixtures thereof.
In one embodiment, the amine-terminated curing agent is
4,4'-bis-(sec-butylamino)-dicyclohexylmethane. In one embodiment,
the amine-terminated curing agent may have a molecular weight of
about 64 or greater. In another embodiment, the molecular weight of
the amine-curing agent is about 2000 or less. In addition, any of
the amine-terminated moieties listed above may be used as curing
agents to react with the prepolymers.
[0160] Of the list above, the saturated amine-terminated curing
agents suitable for use with the present invention include, but are
not limited to, ethylene diamine; hexamethylene diamine;
1-methyl-2,6-cyclohexyl diamine; 2,2,4- and
2,4,4-trimethyl-1,6-hexanediamine;
4,4'-bis-(sec-butylamino)-dicyclohexylmethane;
1,4-bis-(sec-butylamino)-cyclohexane;
1,2-bis-(sec-butylamino)-cyclohexane; derivatives of
4,4'-bis-(sec-butylamino)-dicyclohexylmethane;
4,4'-dicyclohexylmethane diamine;
1,4-cyclohexane-bis-(methylamine);
1,3-cyclohexane-bis-(methylamine); diethylene glycol
bis-(aminopropyl)ether; 2-methylpentamethylene-diamine;
diaminocyclohexane; diethylene triamine; triethylene tetramine;
tetraethylene pentamine; propylene diamine; dipropylene triamine;
1,3-diaminopropane; dimethylamino propylamine; diethylamino
propylamine; imido-bis-(propylamine); monoethanolamine,
diethanolamine; triethanolamine; monoisopropanolamine,
diisopropanolamine; triisopropanolamine; isophoronediamine;
N,N'-diisopropylisophorone diamine and mixtures thereof.
[0161] In one embodiment, the curatives used with the prepolymer
include
3,5-dimethylthio-2,4-toluenediamine,3,5-dimethyl-thio-2,6-toluenediamine,
4,4'-bis-(sec-butylamino)-diphenylmethane,
N,N'-diisopropyl-isophorone diamine; polyoxypropylene diamine;
propylene oxide-based triamine;
3,3'-dimethyl-4,4'-diaminocyclohexylmethane; and mixtures
thereof.
[0162] As briefly discussed above, many amines may be unsuitable
for reaction with the isocyanate because of the rapid reaction
between the two components. In general, unhindered primary diamines
are fast reacting. In one embodiment, however, a hindered secondary
diamine may be suitable for use in the prepolymer. Without being
bound to any particular theory, it is believed that an amine with a
high level of stearic hindrance, e.g., a tertiary butyl group on
the nitrogen atom, has a slower reaction rate than an amine with no
hindrance or a low level of hindrance. For example,
4,4'-bis-(sec-butylamino)-dicyclohexylmethane (Clearlink 1000) may
be suitable for use in combination with an isocyanate to form the
polyurea prepolymer. In addition, N,N'-diisopropyl-isophorone
diamine, available from Huntsman Corporation-under the tradename
Jefflink, may be used as the secondary diamine curing agent.
[0163] To further improve the shear resistance of the resulting
polyurea elastomers, a trifunctional curing agent can be used to
help improve cross-linking. Preferably, a triol such as
trimethylolpropane or a tetraol such as N,N,N',N'-tetrakis
(2-hydroxylpropyl)ethylenediamine may be added to the
formulations.
[0164] The intermediate prepolymers of the invention may also be
cured with a single hydroxy-terminated curing agent or a mixture of
hydroxy-terminated curing agents. As mentioned above, if a
hydroxy-terminated curing agent is used with a polyurea prepolymer
of the invention, the resulting composition will include both urea
and urethane linkages.
[0165] Conversely, if a hydroxy-terminated curing agent is used
with a polyurethane prepolymer, the resulting composition will
include only urethane linkages. For example, when the compositions
of the invention are polyurethane-based, the intermediate
prepolymer may formed by 1) forming a polyurethane prepolymer from
an isocyanate and a polyol or hydroxy-terminated component, 2)
reacting an excess of the polyurethane prepolymer with a
functionalized block copolymer to form an intermediate prepolymer
having the block inside of two NCO groups, and 3) chain extending
the intermediate prepolymer with a hydroxy-terminated curing
agent.
[0166] Suitable hydroxy-terminated curing agents include, but are
not limited to, ethylene glycol; diethylene glycol; polyethylene
glycol; propylene glycol; 2-methyl-1,3-propanediol;
2,-methyl-1,4-butanediol; dipropylene glycol; polypropylene glycol;
1,2-butanediol; 1,3-butanediol; 1,4-butanediol; 2,3-butanediol;
2,3-dimethyl-2,3-butanediol; trimethylolpropane;
cyclohexyldimethylol; triisopropanolamine;
N,N,N'N'-tetra-(2-hydroxypropyl)-ethylene diamine; diethylene
glycol bis-(aminopropyl)ether; 1,5-pentanediol; 1,6-hexanediol;
1,3-bis-(2-hydroxyethoxy)cyclohexane; 1,4-cyclohexyldimethylol;
1,3-bis-[2-(2-hydroxyethoxy)ethoxy]cyclohexane;
1,3-bis-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}cyclohexane;
polytetramethylene ether glycol, preferably having a molecular
weight ranging from about 250 to about 3900;
resorcinol-di-(beta-hydroxyethyl)ether and its derivatives;
hydroquinone-di-(beta-hydroxyethyl)ether and its derivatives;
1,3-bis-(2-hydroxyethoxy)benzene;
1,3-bis-[2-(2-hydroxyethoxy)ethoxy]benzene;
1,3-bis-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}benzene;
N,N-bis(.beta.-hydroxypropyl) aniline;
2-propanol-1,1'-phenylaminobis; and mixtures thereof.
[0167] The hydroxy-terminated curing agent may have a molecular
weight of at least about 50. In one embodiment, the molecular
weight of the hydroxy-terminated curing agent is about 2000 or
less. In yet another embodiment, the hydroxy-terminated curing
agent has a molecular weight of about 250 to about 3900. It should
be understood that molecular weight, as used herein, is the
absolute weight average molecular weight and would be understood as
such by one of ordinary skill in the art.
[0168] The saturated hydroxy-terminated curing agents, included in
the list above, are preferred when making a light stable
composition. Those saturated hydroxy-terminated curing agents
include, but are not limited to, ethylene glycol; diethylene
glycol; polyethylene glycol; propylene glycol;
2-methyl-1,3-propanediol; 2,-methyl-1,4-butanediol; dipropylene
glycol; polypropylene glycol; 1,2-butanediol; 1,3-butanediol;
1,4-butanediol; 2,3-butanediol; 2,3-dimethyl-2,3-butanediol;
trimethylolpropane; cyclohexyldimethylol; triisopropanolamine;
N,N,N',N'-tetra-(2-hydroxypropyl)-ethylene diamine; diethylene
glycol bis-(aminopropyl)ether; 1,5-pentanediol; 1,6-hexanediol;
1,3-bis-(2-hydroxyethoxy)cyclohexane; 1,4-cyclohexyldimethylol;
1,3-bis-[2-(2-hydroxyethoxy)ethoxy]cyclohexane;
1,3-bis-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}cyclohexane;
polytetramethylene ether glycol having molecular weight ranging
from about 250 to about 3900; and mixtures thereof.
[0169] In one embodiment, the curing agent is a modified curative
blend as disclosed in co-pending U.S. Patent Publication No.
2003/0212240, which is incorporated by reference herein in its
entirety. For example, the curing agent of the invention may be
modified with a freezing point depressing agent to create a
curative blend with a slower onset of solidification and with
storage stable pigment dispersion. A number of amine-terminated
curing agents have relatively high freezing points, e.g.,
hexamethylene diamine (105.8.degree. F.), diethanolamine
(82.4.degree. F.), triethanol amine (69.8.degree. F.),
diisopropanolamine (73.4.degree. F.), and triisopropanolamine
(111.2.degree. F.). Such amine-terminated curing agents may be
modified with an amine-terminated freezing point depressing agent
or a mixture of amine-terminated freezing point depressing agents.
Suitable amine-terminated freezing point depressing agents include,
but are not limited to, ethylene diamine, 1,3-diaminopropane,
dimethylamino propylamine, tetraethylene pentamine,
1,2-propylenediamine, diethylaminopropylamine,
2,2,4-trimethyl-1,6-hexanediamine,
2,4,4-trimethyl-1,6-hexanediamine, and mixtures thereof.
[0170] The freezing point depressing agent is preferably added in
an amount sufficient to reduce the freezing point of the curing
agent by a suitable amount to prevent loss of pigment dispersion,
but not affect the physical properties of the golf ball. In one
embodiment, the freezing point depressing agent is added to the
curing agent in an amount of about 5 percent or greater by weight
of the curative blend, i.e., curing agent(s), freezing point
depressing agent. In another embodiment, the freezing point
depressing agent is present in an amount of about 8 percent greater
by weight of the curative blend. In still another embodiment, the
freezing point depressing agent is present in an amount of about 10
percent or greater. In yet another embodiment, the curative blend
includes the freezing point depressing agent in an amount of about
12 percent or greater by weight of the curative blend. The curative
blend may also include a freezing point depressing agent in an
amount of about 14 percent or greater by weight of the curative
blend.
[0171] In addition, after freezing and subsequent thawing, the
modified curative blend of the present invention preferably has a
pigment dispersion of greater than 0 on the Hegman scale,
preferably about 1 or greater, and more preferably about 2 or
greater. In one embodiment, the modified curative blend after a
freeze/thaw cycle has a pigment dispersion of about 3 or greater on
the Hegman scale. In another embodiment, the modified curative
blend after a freeze and thaw is about 4 or greater on the Hegman
scale, preferably about 5 or greater. In still another embodiment,
the modified curative blend after a freeze and thaw is about 6 or
greater on the Hegman scale. In yet another embodiment, the
modified curative blend after freezing and thawing is about 7 or
greater on the Hegman scale.
Reacting a Prepolymer (or Components Thereof) With a Curing
Agent
[0172] The compositions of the invention may also be formed by
chain extending the polyurea prepolymers or polyurethane
prepolymers with any suitable curing agent discussed above. For
example, a polyurea-based composition of the invention may be
formed by chain extending a polyurea prepolymer with an
amine-terminated curing agent, preferably a secondary diamine
curing agent. In addition, a polyurethane-based composition of the
invention may be formed by chain extending a polyurethane
prepolymer with a hydroxy-terminated curing agent.
[0173] Furthermore, polyurea/urethane or polyurethane/urea
compositions may be formed by using a mixture of curing agents. For
example, a polyurea/urethane composition may be formed by chain
extending a polyurea prepolymer with a single hydroxy-terminated
curing agents or a blend including a hydroxy-terminated curing
agent.
[0174] There are two basic techniques used to process the
compositions of the invention: the one-shot technique and the
prepolymer technique. The one-shot technique reacts the isocyanate,
the amine-terminated compound or polyol depending on whether the
desired resultant composition is polyurea-based or
polyurethane-based, and the curing agent in one step, whereas the
prepolymer technique requires a first reaction between the
amine-terminated compound or polyol and an isocyanate to produce
the prepolymer, and a subsequent reaction between the prepolymer
and a curing agent. Either method may be employed to produce the
polyurea-based and polyurethane-based compositions of the
invention, however, the prepolymer technique is preferred because
it provides better control of chemical reaction and, consequently,
results in more uniform properties for the elastomers.
[0175] Depending on the prepolymer to curative ratio, which is a
function of the NCO content of the prepolymer and molecular weight
of the curing agent, the castable polyurea-based or
polyurethane-based compositions of the invention may be thermoset
or thermoplastic in nature. For example, castable thermoplastic
compositions of the invention include linear polymers and are
typically formed curing the prepolymer with a diol or secondary
diamine with 1:1 stoichiometry in the absence of moisture.
Thermoset compositions of the invention, on the other hand, are
cross-linked polymers and are typically produced from the reaction
of a diisocyanate and a polyol cured with a primary diamine or
polyfunctional glycol. In an alternative embodiment, thermoset
polyurethanes may be formed when using a secondary diamine when the
prepolymer to curative ratio is less than about 1. For example, the
composition may be thermoset polyurethane when the prepolymer to
secondary diamine curing agent is 1:0.95.
[0176] In addition, skilled artisans are aware that the various
properties of the golf ball and golf ball components, e.g.,
hardness, may be controlled by adjusting the prepolymer-curative
ratio. For example, the ratio of a polyurea prepolymer with 6
percent unreacted NCO groups cured with 1,4-butanediol is 15.6:1,
whereas the ratio of the same prepolymer cured with
4,4'-bis-(sec-butylamino)-dicyclohexylmethane (Clearlink 1000) is
4.36:1. The ratio of prepolymer to curing agent for the purposes of
this invention is preferably from about 0.5:1 to about 16:1.
[0177] Because the prepolymer-curative ratio determines whether a
composition of the invention will be thermoplastic or thermoset,
the method of molding the compositions of the invention onto the
ball also will vary depending on the composition. For example,
thermoplastic polyurea compositions of the present invention may be
used to make thermoplastic pellets that can be molded onto the ball
by injection molding or compression molding. Thermoset polyurea
compositions may be cast onto the ball. In addition, both the
thermoplastic and thermoset polyurea compositions of the present
invention also may be formed around the core using reaction
injection molding (RIM) and liquid injection molding (LIM)
techniques.
Composition Additives
[0178] Additional materials conventionally included in polyurethane
and polyurea compositions may be added to the polyurethane and
polyurea prepolymers, the modified curative blends, or the
composite compositions of the invention. These additional materials
include, but are not limited to, catalysts, wetting agents,
coloring agents, optical brighteners, crosslinking agents,
whitening agents such as TiO.sub.2 and ZnO, UV absorbers, hindered
amine light stabilizers, defoaming agents, processing aids,
surfactants, and other conventional additives. For example, wetting
additives may be added to the modified curative blends of the
invention to more effectively disperse the pigment(s). Suitable
wetting agents are available from Byk-Chemle and Crompton
Corporation, among others.
[0179] Antioxidants, stabilizers, softening agents, plasticizers,
including internal and external plasticizers, impact modifiers,
foaming agents, density-adjusting fillers, reinforcing materials,
and compatibilizers may also be added to any composition of the
invention. Those of ordinary skill in the art are aware of the
purpose of these additives and the amounts that should be employed
to fulfill those purposes.
Catalysts
[0180] A catalyst may also be employed to promote the reaction
between the prepolymer and the curing agent for both the
polyurethane and polyurea compositions. Suitable catalysts include,
but are not limited to bismuth catalyst; zinc octoate; stannous
octoate; tin catalysts such as bis-butyltin dilaurate (DABCO.RTM.
T-12 manufactured by Air Products and Chemicals, Inc.),
bis-butyltin diacetate (DABCO.RTM. T-1); stannous octoate
(DABCO.RTM.) T-9); tin (II) chloride, tin (IV) chloride,
bis-butyltin dimethoxide (FASCAT.RTM.-4211),
dimethyl-bis[1-oxonedecyl)oxy]stannane (FORMEZ.RTM. UL-28),
di-n-octyltin bis-isooctyl mercaptoacetate (FORMEZ.RTM. UL-29);
amine catalysts such as triethylenediamine (DABCO.RTM. 33-LV),
triethylamine, and tributylamine; organic acids such as oleic acid
and acetic acid; delayed catalysts such as POLYCAT.TM. SA-1,
POLYCAT.TM. SA-2, POLYCAT.TM., and the like; and mixtures thereof.
In one embodiment, the catalyst is bis-butyltin dilaurate.
[0181] The catalyst is preferably added in an amount sufficient to
catalyze the reaction of the components in the reactive mixture. In
one embodiment, the catalyst is present in an amount from about
0.001 percent to about 5 percent by weight of the composition. For
example, when using a tin catalyst, such as bis-butyltin dilaurate,
the catalyst is preferably present in an amount from about 0.005
percent to about 1 percent. In another embodiment, the catalyst is
present in an amount of about 0.05 weight percent or greater. In
another embodiment, the catalyst is present in an amount of about
0.5 weight percent or greater.
[0182] Use of low levels of tin catalysts, typically from about 0
to about 0.04 weight percent of the total composition, requires
high temperatures to achieve a suitable reaction rate, which may
result in degradation of the prepolymer. Increasing the amount of
catalysts to unconventional high levels enables the reduction in
process temperatures while retaining comparable cure stages. Use of
the higher catalyst level also allows the mixing speeds to be
reduced. Thus, in one embodiment, the tin catalyst is present in an
amount from about 0.01 percent to about 0.55 percent by weight of
the composition. In another embodiment, about 0.05 percent to about
0.4 percent of tin catalyst is present in the composition. In yet
another embodiment, the tin catalyst is present in an amount from
about 0.1 percent to about 0.25 percent.
Density-Adjusting Filler(s)
[0183] Fillers may be added to the polyurethane and polyurea
compositions of the invention to affect rheological and mixing
properties, the specific gravity (i.e., density-modifying fillers),
the modulus, the tear strength, reinforcement, and the like. The
fillers are generally inorganic, and suitable fillers include
numerous metals, metal oxides and salts, such as zinc oxide and tin
oxide, as well as barium sulfate, zinc sulfate, calcium carbonate,
zinc carbonate, barium carbonate, clay, tungsten, tungsten carbide,
an array of silicas, regrind (recycled core material typically
ground to about 30 mesh particle), high-Mooney-viscosity rubber
regrind, and mixtures thereof.
[0184] For example, the compositions of the invention can be
reinforced by blending with a wide range of density-adjusting
fillers, e.g., ceramics, glass spheres (solid or hollow, and filled
or unfilled), and fibers, inorganic particles, and metal particles,
such as metal flakes, metallic powders, oxides, and derivatives
thereof, as is known to those with skill in the art. The selection
of such filler(s) is dependent upon the type of golf ball desired,
i.e., one-piece, two-piece, multi-component, or wound, as will be
more fully detailed below. Generally, the filler will be inorganic,
having a density of greater than 4 g/cc, and will be present in
amounts between about 5 and about 65 weight percent based on the
total weight of the polymer components included in the layer(s) in
question. Examples of useful fillers include zinc oxide, barium
sulfate, calcium oxide, calcium carbonate, and silica, as well as
other known corresponding salts and oxides thereof.
[0185] Fillers may also be used to modify the weight of the core or
at least one additional layer for specialty balls, e.g., a lower
weight ball is preferred for a player having a low swing speed.
Blowing or Foaming Agent(s)
[0186] The compositions of the invention may be foamed by the
addition of the at least one physical or chemical blowing or
foaming agent. The use of a foamed polymer allows the golf ball
designer to adjust the density or mass distribution of the ball to
adjust the angular moment of inertia, and, thus, the spin rate and
performance of the ball. Foamed materials also offer a potential
cost savings due to the reduced use of polymeric material.
[0187] Blowing or foaming agents useful include, but are not
limited to, organic blowing agents, such as azobisformamide;
azobisisobutyronitrile; diazoaminobenzene;
N,N-dimethyl-N,N-dinitroso terephthalamide;
N,N-dinitrosopentamethylene-tetramine; benzenesulfonyl-hydrazide;
benzene-1,3-disulfonyl hydrazide; diphenylsulfon-3-3, disulfonyl
hydrazide; 4,4'-oxybis benzene sulfonyl hydrazide; p-toluene
sulfonyl semicarbizide; barium azodicarboxylate; butylamine
nitrile; nitroureas; trihydrazino triazine; phenyl-methyl-uranthan;
p-sulfonhydrazide; peroxides; and inorganic blowing agents such as
ammonium bicarbonate and sodium bicarbonate. A gas, such as air,
nitrogen, carbon dioxide, etc., can also be injected into the
composition during the injection molding process.
[0188] Additionally, a foamed composition of the present invention
may be formed by blending microspheres with the composition either
during or before the molding process. Polymeric, ceramic, metal,
and glass microspheres are useful in the invention, and may be
solid or hollow and filled or unfilled. In particular, microspheres
up to about 1000 micrometers in diameter are useful. Furthermore,
the use of liquid nitrogen for foaming, as disclosed in U.S. Pat.
No. 6,386,992, which is incorporated by reference herein, may
produce highly uniform foamed compositions for use in the present
invention.
[0189] Either injection molding or compression molding may be used
to form a layer including a foamed polymeric material. For example,
a composition of the present invention can be thermoformed and,
thus, can be compression molded. For compression molded grafted
metallocene catalyzed polymer blend layers, half-shells may be made
by injection molding a grafted metallocene catalyzed polymer blend
in a conventional half-shell mold or by compression molding sheets
of foamed grafted metallocene catalyzed polymer. The half-shells
are placed about a previously formed center or core, cover, or
mantle layer, and the assembly is introduced into a compression
molding machine, and compression molded at about 250.degree. F. to
400.degree. F. The molded balls are then cooled while still in the
mold, and finally removed when the layer of grafted metallocene
catalyzed polymer blend is hard enough to be handled without
deforming. Additional core, mantle, and cover layers are then
molded onto the previously molded layers, as needed, until a
complete ball is formed.
Light Stabilizers
[0190] The compositions of the invention may include both saturated
and unsaturated components. And, while the use of only saturated
components aids in avoiding the yellowing over time that occurs
with unsaturated components, the use of various UV absorbers and
light stabilizers to any of the above compositions may help to also
maintain the tensile strength, elongation, and color stability. The
use of light stabilizing components also may assist in preventing
cover surface fractures due to photodegredation.
[0191] As such, the compositions of the invention may contain at
least one light stabilizing component to prevent significant
yellowing from unsaturated components contained therein. The use of
a light stabilizer is preferred, for instance, for compositions
having a difference in yellowness (.DELTA.Y) of about 15 or
greater, but also may be added to compositions having a difference
in yellowness of from about 12 to about 15. As used herein, light
stabilizer may be understood to include hindered amine light
stabilizers, ultraviolet (UV) absorbers, and antioxidants.
[0192] Suitable light stabilizers include, but are not limited to,
TINUVIN.RTM. 292, TINUVIN.RTM. 328, TINUVIN.RTM. 213, TINUVIN.RTM.
765, TINUVIN.RTM. 770 and TINUVIN.RTM. 622. TINUVIN.RTM. products
are available from Ciba Specialty Chemicals of Tarrytown, N.Y. In
one embodiment, the light stabilizer is UV absorber TINUVIN.RTM.
328, which is useful with aromatic compounds. In another
embodiment, hindered amine light stabilizer TINUVIN.RTM. 765 is
used with aromatic or aliphatic compounds. In addition,
TINUVIN.RTM. 292 may also be used with the aromatic or aliphatic
compositions of the invention.
[0193] As discussed above, dyes, as well as optical brighteners and
fluorescent pigments may also be included in the golf ball covers
produced with polymers formed according to the present invention.
Such additional ingredients may be added in any amounts that will
achieve their desired purpose.
[0194] To further improve the shear resistance and heat resistance
of the resulting polyurea elastomers, a multi-functional curing
agent can be used to help improve cross-linking. In one embodiment
of the present invention, the multi-functional curing agent is
modified with a compatible freezing point depressing agent as
detailed above. For example, a triol such as trimethylolpropane or
a tetraol such as N,N, N',N'-tetrakis
(2-hydroxylpropyl)ethylenediamine may be added to the composition.
In one embodiment, a primary diamine, such as
3,3'-dimethyl-4,4'-diaminodicyclohexylmethane or
4,4'-diaminodicyclohexylmethane is added to the polyurea
composition. Useful triamine curing agents for improving the
crosslinking of polyurea elastomers include, but are not limited
to: propylene oxide-based triamines; trimethylolpropane-based
triamines; glycerin-based triamines;
N,N-bis{2-[(aminocarbonyl)amino]ethyl}-urea;
N,N',N''-tris(2-aminoethyl)-methanetriamine;
N1-(5-aminopentyl)-1,2,6-hexanetriamine; 1,1,2-ethanetriamine;
N,N',N''-tris(3-aminopropyl)-methanetriamine;
N1-(2-aminoethyl)-1,2,6-hexanetriamine;
N1-(10-aminodecyl)-1,2,6-hexanetriamine; 1,9,18-octadecanetriamine;
4,10,16,22-tetraazapentacosane-1,13,25-triamine;
N1-{3-[[4-[(3-aminopropyl)amino]butyl]amino]propyl}-1,2,6-hexanetriamine;
di-9-octadecenyl-(Z,Z)-1,2,3-propanetriamine; 1,4,8-octanetriamine;
1,5,9-nonanetriamine; 1,9,10-octadecanetriamine; [0195]
1,4,7-heptanetriamine; 1,5,10-decanetriamine;
1,8,17-heptadecanetriamine; 1,2,4-butanetriamine; propanetriamine;
1,3,5-pentanetriamine;
N1-{3-[[4-[(3-aminopropyl)amino]butyl]amino]propyl}-1,2,6-hexanetriamine;
N1-{4-[(3-aminopropyl)amino]butyl}-1,2,6-hexanetriamine;
2,5-dimethyl-1,4,7-heptanetriamine;
N1-(6-aminohexyl)-1,2,6-hexanetriamine;
6-ethyl-3,9-dimethyl-3,6,9-undecanetriamine;
1,5,11-undecanetriamine; 1,6,11-undecanetriamine;
N,N-bis(aminomethyl)-methanediamine;
N,N-bis(2-aminoethyl)-1,3-propanediamine; methanetriamine;
N1-(2-aminoethyl)-N2-(3-aminopropyl)-1,2,5-pentanetriamine;
N1-(2-aminoethyl)-1,2,6-hexanetriamine;
2,6,11-trimethyl-2,6,11-dodecanetriamine; 1,1,3-propanetriamine;
6-(aminomethyl)-1,4,9-nonanetriamine; 1,2,6-hexanetriamine;
N2-(2-aminoethyl)-1,11,2-ethanetriamine; 1,3,6-hexanetriamine;
N,N-bis(2-aminoethyl)-1,2-ethanediamine;
3-(aminomethyl)-1,2,4-butanetriamine; 1,1,1-ethanetriamine;
N1,N1-bis(2-aminoethyl) 1,2-propanediamine; 1,2,3-propanetriamine;
2-methyl-1,2,3-propanetriamine; and mixtures thereof.
Fragrance Components
[0196] Some materials used in the polyurea or polyurethane
compositions of the invention are odorous in nature or produce
odors during reaction with other materials or with oxygen. For
example, the odor of curative Ethacure 300 is attributed to
dimethyl disulfide (DMDS) once the product reacts with oxygen. As
used herein, a material or component is odorous when the odor
threshold surpasses a threshold of 0.029 mg/m.sup.3 in air. A
fragrance or masking component may be added to the compositions of
the invention to eliminate odors. The fragrance component is
preferably added in an amount of about 0.01 percent to about 1.5
percent by weight of the composition. In one embodiment, the
fragrance component is added to the composition in an amount of
about 0.03 percent or greater by weight of the composition. In
another embodiment, the fragrance component is added to the
composition in an amount of about 1.2 percent or less by weight of
the composition. In yet another embodiment, the fragrance component
is added in an amount of about 0.5 percent to about 1 percent by
weight of the composition. For example, an optimum loading of the
fragrance component may be about 0.08 percent by weight of the
composition, but adding more may enhance the effect if needed.
[0197] Suitable fragrance components include, but are not limited
to, Long Lasting Fragrance Mask #59672, Long Lasting Fragrance Mask
#46064, Long Lasting Fragrance Mask #55248, Non-Descript Fragrance
Mask #97779, Fresh and Clean Fragrance Mask #88177, and Garden
Fresh Fragrance Mask #87473, all of which are manufactured by
Flavor and Fragrance Specialties of Mahwah, N.J. Other non-limiting
examples of fragrance components that may be added to the
compositions of the invention include benzaldehyde, benzyl
benzoate, benzyl propionate, benzyl salicylate, benzyl alcohol,
cinnamic aldehydes, natural and essential oils derived from
botanical sources, and mixtures thereof.
Composition Blends
[0198] The compositions of the invention preferably include from
about 1 percent to about 1100 percent polyurea-based polymers or
polyurethane-based polymers, however, the compositions may also be
blended with other materials. In one embodiment, the composition
contains about 10 percent to about 90 percent polyurea-based
polymer or polyurethane-based polymer, preferably from about 10
percent to about 75 percent polyurea-based polymer or
polyurethane-based polymer, and contains about 90 percent to 10
percent, more preferably from about 90 percent to about 25 percent
other polymers and/or other materials as described below. Unless
otherwise stated herein, all percentages are given in percent by
weight of the total composition of the golf ball layer in
question.
[0199] Other polymeric materials suitable for blending with the
compositions of the invention include castable thermoplastics,
cationic and anionic urethane ionomers and urethane epoxies,
polyurethane ionomers, polyurea ionomers, epoxy resins,
polyethylenes, polyamides and polyesters, polycarbonates,
polyacrylin, siloxanes and epoxy resins or their blends, and
mixtures thereof. One of ordinary skill in the art would be well
aware of methods to blend the polymeric materials with the
composition of the invention.
[0200] Examples of suitable urethane ionomers are disclosed in U.S.
Pat. No. 5,692,974, the disclosure of which is hereby incorporated
by reference in its entirety. Other examples of suitable
polyurethanes are described in U.S. Pat. No. 5,334,673, the entire
disclosure of which is incorporated by reference herein. Examples
of suitable polyureas used to form the polyurea ionomer listed
above are discussed in U.S. Pat. No. 5,484,870. In particular, the
polyureas of U.S. Pat. No. 5,484,870 are prepared by reacting a
polyisocyanate and a polyamine curing agent to yield polyurea,
which are distinct from the polyureas of the present invention
which are formed from a polyurea prepolymer and curing agent.
Examples of suitable polyurethanes cured with epoxy group
containing curing agents are disclosed in U.S. Pat. No. 5,908,358.
The disclosures of the above patents are incorporated herein by
reference in their entirety.
[0201] The polyurea-based compositions and polyurethane-based
compositions of the invention may also be in the form of a blend
with at least one highly neutralized polymer. For example, a
prepolymer can be chain extended with a curing agent and then
blended with a highly neutralized polymer. Suitable highly
neutralized polymers include, but are not limited to, polymers
containing .alpha.,.beta.-unsaturated carboxylic acid groups, or
the salts thereof, that have been highly neutralized by organic
fatty acids. The organic acids are aliphatic, mono-functional
(saturated, unsaturated, or multi-unsaturated) organic acids. Salts
of these organic acids may also be employed. The salts of organic
acids of the present invention include the salts of barium,
lithium, sodium, zinc, bismuth, chromium, cobalt, copper,
potassium, strontium, titanium, tungsten, magnesium, cesium, iron,
nickel, silver, aluminum, tin, or calcium, salts of fatty acids,
particularly stearic, behenic, erucic, oleic, linoleic, or
dimerized derivatives thereof. It is preferred that the organic
acids and salts of the present invention be relatively
non-migratory (they do not bloom to the surface of the polymer
under ambient temperatures) and non-volatile (they do not
volatilize at temperatures required for melt-blending). The acid
moieties of the highly-neutralized polymers ("HNP"), typically
ethylene-based ionomers, are preferably neutralized greater than
about 70 percent, more preferably greater than about 90 percent,
and most preferably at least about 100 percent.
Acid Functionalization of Compositions
[0202] The present invention also contemplates the acid
functionalization of the polyurethane and polyurea compositions of
the invention as disclosed in U.S. Pat. No. 6,610,812, which is
incorporated by reference herein in its entirety. The acid
functional group is preferably based on a sulfonic group
(HSO.sub.3), carboxylic group (HCO.sub.2), phosphoric acid group
(H.sub.2PO.sub.3), or a combination thereof. More than one type of
acid functional group may be incorporated into the polyurea or
polyurethane.
Golf Ball Core Layer(s)
[0203] The cores of the golf balls formed according to the
invention may be solid, semi-solid, hollow, fluid-filled or
powder-filled, one-piece or multi-component cores. The term
"semi-solid" as used herein refers to a paste, a gel, or the like.
Any core material known to one of ordinary skill in that art is
suitable for use in the golf balls of the invention. Suitable core
materials include thermoset materials, such as rubber, styrene
butadiene, polybutadiene, isoprene, polyisoprene, trans-isoprene,
as well as thermoplastics such as ionomer resins, polyamides or
polyesters, and thermoplastic and thermoset polyurethane
elastomers. As mentioned above, the polyurethane or polyurea
compositions of the present invention may also be incorporated into
any component of a golf ball, including the core. For example, a
core layer may contain at least one of the polyurea/urea
compositions, polyurea/urethane compositions, polyurethane/urethane
compositions, or polyurethane/urea compositions of the
invention.
[0204] In one embodiment, the golf ball core is formed from a
composition including a base rubber (natural, synthetic, or a
combination thereof), a crosslinking agent, and a filler. In
another embodiment, the golf ball core is formed from a reaction
product that includes a cis-to-trans catalyst, a resilient polymer
component having polybutadiene, a free radical source, and
optionally, a crosslinking agent, a filler, or both. Various
combinations of polymers, cis-to-trans catalysts, fillers,
crosslinkers, and a source of free radicals, such as those
disclosed in co-pending U.S. Patent Publication No. 2003/0119989,
the entire disclosure of which is incorporated by reference herein,
may be used to form the reaction product. Although this
polybutadiene reaction product is discussed in a section pertaining
to core compositions, the present invention also contemplates the
use of the reaction product to form at least a portion of any
component of a golf ball.
[0205] As used herein, the terms core and center are generally used
interchangeably to reference the innermost component of the ball.
In some embodiments, however, the term "center" is used when there
are multiple core layers, i.e., a center and an outer core
layer.
Golf Ball Intermediate Layer(s)
[0206] When the golf ball of the present invention includes an
intermediate layer, such as an inner cover layer or outer core
layer, i.e., any layer(s) disposed between the inner core and the
outer cover of a golf ball, this layer can include any materials
known to those of ordinary skill in the art including thermoplastic
and thermosetting materials. In one embodiment, the intermediate
layer is formed, at least in part, from any of the
polyurethane-based and polyurea-based compositions discussed
above.
[0207] The intermediate layer(s) may also likewise include one or
more homopolymeric or copolymeric materials, such as: [0208] (1)
Vinyl resins, such as those formed by the polymerization of vinyl
chloride, or by the copolymerization of vinyl chloride with vinyl
acetate, acrylic esters or vinylidene chloride; [0209] (2)
Polyolefins, such as polyethylene, polypropylene, polybutylene and
copolymers such as ethylene methylacrylate, ethylene ethylacrylate,
ethylene vinyl acetate, ethylene methacrylic or ethylene acrylic
acid or propylene acrylic acid and copolymers and homopolymers
produced using a single-site catalyst or a metallocene catalyst;
[0210] (3) Polyurethanes, such as those prepared from polyols and
diisocyanates or polyisocyanates and those disclosed in U.S. Pat.
No. 5,334,673; [0211] (4) Polyureas, such as those disclosed in
U.S. Pat. No. 5,484,870; [0212] (5) Polyamides, such as
poly(hexamethylene adipamide) and others prepared from diamines and
dibasic acids, as well as those from amino acids such as
poly(caprolactam), and blends of polyamides with SURLYN,
polyethylene, ethylene copolymers, ethyl-propylene-non-conjugated
diene terpolymer, and the like; [0213] (6) Acrylic resins and
blends of these resins with poly vinyl chloride, elastomers, and
the like; [0214] (7) Thermoplastics, such as urethanes; olefinic
thermoplastic rubbers, such as blends of polyolefins with
ethylene-propylene-non-conjugated diene terpolymer; block
copolymers of styrene and butadiene, isoprene or ethylene-butylene
rubber; or copoly(ether-amide), such as PEBAX, sold by Atofina
Chemicals, Inc. of Philadelphia, Pa.; [0215] (8) Polyphenylene
oxide resins or blends of polyphenylene oxide with high impact
polystyrene as sold under the trademark NORYL by General Electric
Company of Pittsfield, Mass.; [0216] (9) Thermoplastic polyesters,
such as polyethylene terephthalate, polybutylene terephthalate,
polyethylene terephthalate/glycol modified and elastomers sold
under the trademarks HYTREL by E.I. DuPont de Nemours & Co. of
Wilmington, Del., and LOMOD by General Electric Company of
Pittsfield, Mass.; [0217] (10) Blends and alloys, including
polycarbonate with acrylonitrile butadiene styrene, polybutylene
terephthalate, polyethylene terephthalate, styrene maleic
anhydride, polyethylene, elastomers, and the like, and polyvinyl
chloride with acrylonitrile butadiene styrene or ethylene vinyl
acetate or other elastomers; and [0218] (11) Blends of
thermoplastic rubbers with polyethylene, propylene, polyacetal,
nylon, polyesters, cellulose esters, and the like.
[0219] In one embodiment, the intermediate layer includes polymers,
such as ethylene, propylene, butene-1 or hexene-1 based
homopolymers or copolymers including functional monomers, such as
acrylic and methacrylic acid and fully or partially neutralized
ionomer resins and their blends, methyl acrylate, methyl
methacrylate homopolymers and copolymers, imidized, amino group
containing polymers, polycarbonate, reinforced polyamides,
polyphenylene oxide, high impact polystyrene, polyether ketone,
polysulfone, poly(phenylene sulfide), acrylonitrile-butadiene,
acrylic-styrene-acrylonitrile, poly(ethylene terephthalate),
poly(butylene terephthalate), poly(ethylene vinyl alcohol),
poly(tetrafluoroethylene) and their copolymers including functional
comonomers, and blends thereof. For example, the intermediate layer
may be formed of low acid ionomers, such as those described in U.S.
Pat. Nos. 6,506,130 and 6,503,156, high acid ionomers, highly
neutralized polymers, such as those disclosed in U.S. Patent
Publication Nos. 2001/0018375 and 2001/0019971, or mixtures
thereof. The intermediate layer may also be formed from the
compositions as disclosed in U.S. Pat. No. 5,688,191. The entire
disclosures of these patents and publications are incorporated
herein by express reference thereto.
[0220] In another embodiment, the intermediate layer includes at
least one primarily or fully non-ionomeric thermoplastic material.
Suitable non-ionomeric materials include polyamides and polyamide
blends, grafted and non-grafted metallocene catalyzed polyolefins
or polyamides, polyamide/ionomer blends, polyamide/nonionomer
blends, polyphenylene ether/ionomer blends, and mixtures thereof.
Examples of grafted and non-grafted metallocene catalyzed
polyolefins or polyamides, polyamide/ionomer blends,
polyamide/nonionomer blends are disclosed in co-pending U.S. Patent
Publication No. 2003/0078348, the entire disclosure of which is
incorporated by reference herein. Another example of a
polyamide-nonionomer blend is a polyamide and non-ionic polymers
produced using non-metallocene single-site catalysts. Examples of
suitable single-site catalyzed polymers are disclosed in co-pending
U.S. Pat. No. 6,476,130, of which the entire disclosure is
incorporated by reference herein.
Golf Ball Cover(s)
[0221] The cover provides the interface between the ball and a
club. Properties that are desirable for the cover are good
moldability, high abrasion resistance, high impact resistance, high
tear strength, high resilience, and good mold release, among
others.
[0222] The cover layer may be formed, at least in part, from at
least one of the polyurethane-based or polyurea-based compositions
of the invention. For example, a cover layer may be formed of a
polyurea-based composition that includes styrene-butadiene-styrene
block copolymer.
[0223] The cover layer(s) may also be formed from composition
blends as discussed above. For example, in one embodiment, at least
one cover layer is formed from a blend of about 10 percent to about
90 percent of a polyurea-based material, preferably saturated, and
about 90 percent to about 10 percent other polymers and/or other
materials. In another embodiment, at least one cover layer is
formed from a blend of about 10 percent to about 90 percent of a
polyurethane-based material, preferably saturated, and about 90
percent to about 10 percent other polymers and/or other materials.
In yet another embodiment, the cover compositions include from
about 10 percent to about 75 percent of a polyurea-based or
polyurethane-based material and about 90 percent to about 25
percent other polymers and/or other materials, such as those listed
below.
[0224] When the polyurethane-based and polyurea-based compositions
of the invention are incorporated into a core or intermediate/inner
cover layer, the cover compositions may include one or more
homopolymeric or copolymeric materials as discussed in the section
above pertaining to the intermediate layer. The cover may also be
at least partially formed from the polybutadiene reaction product
discussed above with respect to the core.
[0225] As discussed elsewhere herein, the composition may be molded
onto the golf ball in any known manner, such as by casting,
compression molding, injection molding, reaction injection molding,
or the like. One skilled in the art would appreciate that the
molding method used may be determined at least partially by the
properties of the composition. For example, casting may be
preferred when the material is thermoset, whereas compression
molding or injection molding may be preferred for thermoplastic
compositions.
Golf Ball Construction
[0226] The compositions of the present invention may be used with
any type of ball construction including, but not limited to,
one-piece, two-piece, three-piece, and four-piece designs, a double
core, a double cover, an intermediate layer(s), a multilayer core,
and/or a multi-layer cover depending on the type of performance
desired of the ball. That is, the compositions of the invention may
be used in a core, intermediate layer, and/or cover of a golf ball,
each of which may have a single layer or multiple layers. As used
herein, the term "multilayer" means at least two layers.
[0227] As described above in the core section, a core may be a
one-piece core or a multilayer core, both of which may be solid,
semi-solid, hollow, fluid-filled, or powder-filled. A multilayer
core is one that has an innermost component with an additional core
layer or additional core layers disposed thereon. For example, FIG.
1 shows a golf ball 1 having a core 2 and a cover 3. In one
embodiment, the golf ball of FIG. 1 represents a core 2 of
polybutadiene reaction material or other conventional materials and
a cover 3 including the polyurea-based composition of the
invention. In another embodiment, the golf ball of FIG. 1
represents a core 2 formed from polybutadiene reaction material and
a cover 3 including the polyurethane-based composition of the
invention.
[0228] In addition, when the golf ball of the present invention
includes an intermediate layer, this layer may be incorporated with
a single or multilayer cover, a single or multi-piece core, with
both a single layer cover and core, or with both a multilayer cover
and a multilayer core. The intermediate layer may be an inner cover
layer or outer core layer, or any other layer(s) disposed between
the inner core and the outer cover of a golf ball. As with the
core, the intermediate layer may also include a plurality of
layers. It will be appreciated that any number or type of
intermediate layers may be used, as desired.
[0229] FIG. 2 illustrates a multilayer golf ball 11, including a
cover 13, at least one intermediate layer 14, and a core 12. In one
embodiment, the golf ball 11 of FIG. 2 may include a core 12 of
polybutadiene reaction material, an intermediate layer 14, and a
cover 13 formed of the polyurea-based composition of the invention.
In addition, the golf ball 21 of FIG. 3 has a core 22 of
polybutadiene reaction material or other conventional core
materials, at least one intermediate layer 24, and cover 23
including at least one polyurethane-based material of the present
invention. In one embodiment, the intermediate layer 14 is formed
of an ionomeric material.
[0230] The intermediate layer may also be a tensioned elastomeric
material wound around a solid, semi-solid, hollow, fluid-filled, or
powder-filled center. As used herein, the term "fluid" refers to a
liquid or gas and the term "semi-solid" refers to a paste, gel, or
the like. A wound layer may be described as a core layer or an
intermediate layer for the purposes of the invention. As an
example, the golf ball 31 of FIG. 4 may include a core layer 32, a
tensioned elastomeric layer 34 wound thereon, and a cover layer 33.
In particular, the golf ball 31 of FIG. 4 may have a core 32 made
of a polybutadiene reaction product, an intermediate layer
including a tensioned elastomeric material 34 and cover 33
including at least one polyurea-based or polyurethane-based
composition of the invention. The tensioned elastomeric material
may be formed of any suitable material known to those of ordinary
skill in the art.
[0231] In yet another embodiment, the golf ball 41 of FIG. 5 has a
hollow spherical core shell 42 with its hollow interior filled with
a liquid 43, a thread rubber layer including a tensioned
elastomeric material 44 and a cover 45 including at least one
polyurea-based or polyurethane-based composition of the
invention.
[0232] Likewise, the cover may include a plurality of layers, e.g.,
an inner cover layer disposed about a golf ball center and an outer
cover layer formed thereon. For example, FIG. 6 may represent a
golf ball 51 having a core 52, a thin inner cover layer 54, and a
thin outer cover layer 53 disposed thereon. In particular, the core
51 may be formed of a polybutadiene reaction material, the inner
cover layer 54 formed of an ionomer blend, and the outer cover
layer 53 formed of the polyurea-based or polyurethane-based
compositions of the invention. In addition, FIG. 7 may represent a
golf ball 61 having a core 62, an outer core layer 65, a thin inner
cover layer 64, and a thin outer cover layer 63 disposed thereon.
In one embodiment, the core 62 and the outer core layer 65 are
formed of the polybutadiene reaction material but differ in
hardness, the inner cover layer 64 is formed of an ionomer blend,
and the outer cover layer 63 is formed of a polyurea-based or
polyurethane-based composition of the invention.
[0233] Furthermore, the compositions of the invention may be used
to form a golf ball 71, shown in FIG. 8, having a large core 72 and
a thin outer cover layer 73. In one embodiment, the large core 72
is formed of a polybutadiene reaction material and the thin outer
cover layer 73 is formed of a polyurea-based or polyurethane-based
composition of the invention.
[0234] While hardness gradients are typically used in a golf ball
to achieve certain characteristics, the present invention also
contemplates the compositions of the invention being used in a golf
ball with multiple cover layers having essentially the same
hardness, wherein at least one of the layers has been modified in
some way to alter a property that affects the performance of the
ball. Such ball constructions are disclosed in co-pending U.S.
Patent Publication No. 2003/0232666, the entire disclosure of which
is incorporated by reference herein.
[0235] Other non-limiting examples of suitable types of ball
constructions that may be used with the present invention include
those described in U.S. Pat. Nos. 6,056,842, 5,688,191, 5,713,801,
5,803,831, 5,885,172, 5,919,100, 5,965,669, 5,981,654, 5,981,658,
and 6,149,535, as well as in Publication Nos. US2001/0009310 A1,
US2002/0025862, and US2002/0028885. The entire disclosures of these
patents and published patent applications are incorporated by
reference herein.
Methods of Forming Layers
[0236] The golf balls of the invention may be formed using a
variety of application techniques such as compression molding, flip
molding, injection molding, retractable pin injection molding,
reaction injection molding (RIM), liquid injection molding (LIM),
casting, vacuum forming, powder coating, flow coating, spin
coating, dipping, spraying, and the like. Conventionally,
compression molding and injection molding are applied to
thermoplastic materials, whereas RIM, liquid injection molding, and
casting are employed on thermoset materials. These and other
manufacture methods are disclosed in U.S. Pat. Nos. 6,207,784 and
5,484,870, the disclosures of which are incorporated herein by
reference in their entirety.
[0237] The cores of the invention may be formed by any suitable
method known to those of ordinary skill in art. When the cores are
formed from a thermoset material, compression molding is a
particularly suitable method of forming the core. In a
thermoplastic core embodiment, on the other hand, the cores may be
injection molded. Furthermore, U.S. Pat. Nos. 6,180,040 and
6,180,722 disclose methods of preparing dual core golf balls. The
disclosures of these patents are hereby incorporated by reference
in their entirety.
[0238] The intermediate layer may also be formed from using any
suitable method known to those of ordinary skill in the art. For
example, an intermediate layer may be formed by blow molding and
covered with a dimpled cover layer formed by injection molding,
compression molding, casting, vacuum forming, powder coating, and
the like.
[0239] The polyurea-based and polyurethane-based materials of the
invention may be applied over the inner ball using a variety of
application techniques such as spraying, compression molding,
dipping, spin coating, casting, or flow coating methods that are
well known in the art. In one embodiment, the polyurea-based or
polyurethane-based materials are formed over the core using a
combination of casting and compression molding. Conventionally,
compression molding and injection molding are applied to
thermoplastic cover materials, whereas RIM, liquid injection
molding, and casting are employed on thermoset cover materials.
[0240] U.S. Pat. No. 5,733,428, the entire disclosure of which is
hereby incorporated by reference, discloses a method for forming a
polyurethane-based cover on a golf ball core. Because this method
relates to the use of both casting thermosetting and thermoplastic
material as the golf ball cover, wherein the cover is formed around
the core by mixing and introducing the material in mold halves, the
polyurea-based compositions may also be used employing the same
casting process.
[0241] For example, once the polyurea-based composition or
polyurethane-based composition is mixed, an exothermic reaction
commences and continues until the material is solidified around the
core. It is important that the viscosity be measured over time, so
that the subsequent steps of filling each mold half, introducing
the core into one half and closing the mold can be properly timed
for accomplishing centering of the core cover halves fusion and
achieving overall uniformity. A suitable viscosity range of the
curing urea mix for introducing cores into the mold halves is
determined to be approximately between about 2,000 cP and about
30,000 cP, with the preferred range of about 8,000 cP to about
15,000 cP.
[0242] To start the cover formation, mixing of the prepolymer and
curative is accomplished in a motorized mixer inside a mixing head
by metering amounts of the curative and prepolymer through the feed
lines. Top preheated mold halves are filled and placed in fixture
units using centering pins moving into apertures in each mold. At a
later time, the cavity of a bottom mold half, or the cavities of a
series of bottom mold halves, is filled with similar mixture
amounts as used for the top mold halves. After the reacting
materials have resided in top mold halves for about 40 to about 100
seconds, preferably for about 70 to about 80 seconds, a core is
lowered at a controlled speed into the gelling reacting
mixture.
[0243] A ball cup holds the ball core through reduced pressure (or
partial vacuum). Upon location of the core in the halves of the
mold after gelling for about 4 to about 12 seconds, the vacuum is
released allowing the core to be released. In one embodiment, the
vacuum is released allowing the core to be released after about 5
seconds to 10 seconds. The mold halves, with core and solidified
cover half thereon, are removed from the centering fixture unit,
inverted and mated with second mold halves which, at an appropriate
time earlier, have had a selected quantity of reacting prepolymer
and curing agent introduced therein to commence gelling.
[0244] Similarly, U.S. Pat. No. 5,006,297 and U.S. Pat. No.
5,334,673 both also disclose suitable molding techniques that may
be utilized to apply the polyurea-based and polyurethane-based
compositions of the invention. However, the method of the invention
is not limited to the use of these techniques; other methods known
to those skilled in the art may also be employed. For instance,
other methods for holding the ball core may be utilized instead of
using a partial vacuum.
Dimples
[0245] The use of various dimple patterns and profiles provides a
relatively effective way to modify the aerodynamic characteristics
of a golf ball. As such, the manner in which the dimples are
arranged on the surface of the ball can be by any available method.
For instance, the ball may have an icosahedron-based pattern, such
as described in U.S. Pat. No. 4,560,168, or an octahedral-based
dimple patterns as described in U.S. Pat. No. 4,960,281.
Alternatively, the dimple pattern can be arranged according to
phyllotactic patterns, such as described in U.S. Pat. No.
6,338,684, which is incorporated herein in its entirety.
[0246] Dimple patterns may also be based on Archimedean patterns
including a truncated octahedron, a great rhombcuboctahedron, a
truncated dodecahedron, and a great rhombicosidodecahedron, wherein
the pattern has a non-linear parting line, as disclosed in U.S.
Patent Publication No. 2003/0158001, which is incorporated by
reference herein.
[0247] The golf balls of the present invention may also be covered
with non-circular shaped dimples, i.e., amorphous shaped dimples,
as disclosed in U.S. Pat. No. 6,409,615, which is incorporated in
its entirety by reference herein.
[0248] Dimple patterns that provide a high percentage of surface
coverage are preferred, and are well known in the art. For example,
U.S. Pat. Nos. 5,562,552, 5.575, 477, 5,957,787, 5,249,804, and
4,925,193 disclose geometric patterns for positioning dimples on a
golf ball so as to provide a high degree of surface coverage. In
addition, a tubular lattice pattern, such as the one disclosed in
U.S. Pat. No. 6,290,615, which is incorporated by reference in its
entirety herein, may also be used with golf balls of the present
invention. The golf balls of the present invention may also have a
plurality of pyramidal projections disposed on the intermediate
layer of the ball, as disclosed in U.S. Pat. No. 6,383,092, which
is incorporated in its entirety by reference herein.
[0249] Several additional non-limiting examples of dimple patterns
with varying sizes of dimples are also provided in U.S. Pat. Nos.
6,358,161 and 6,213,898, the entire disclosures of which are
incorporated by reference herein.
[0250] Dimple profiles revolving a catenary curve about its
symmetrical axis may increase aerodynamic efficiency, provide a
convenient way to alter the dimples to adjust ball performance
without changing the dimple pattern, and result in uniformly
increased flight distance for golfers of all swing speeds. Thus,
catenary curve dimple profiles, as disclosed in U.S. Patent
Publication No. 2003/0114255, which is incorporated in its entirety
by reference herein, is contemplated for use with the golf balls of
the present invention.
Golf Ball Post-Processing
[0251] The golf balls of the present invention may be painted,
coated, or surface treated for further benefits. For example, golf
balls covers frequently contain a fluorescent material and/or a dye
or pigment to achieve the desired color characteristics. A golf
ball of the invention may also be treated with a base resin paint
composition. In addition, the golf ball may be coated with a
composition including a whitening agent.
[0252] In one embodiment, the golf balls of the invention may be UV
cured. Suitable methods for UV curing are disclosed in U.S. Pat.
Nos. 6,500,495, 6,248,804, and 6,099,415, the entire disclosures of
which are incorporated by reference herein. In one embodiment, the
top coat is UV curable. In another embodiment, the ink is UV
curable and may be used as a paint layer or as a discrete marking
tool for logos and indicias.
[0253] In addition, trademarks or other indicia may be stamped,
i.e., pad-printed, on the outer surface of the ball cover, and the
stamped outer surface is then treated with at least one clear coat
to give the ball a glossy finish and protect the indicia stamped on
the cover.
[0254] The golf balls of the invention may also be subjected to dye
sublimation, wherein at least one golf ball component is subjected
to at least one sublimating ink that migrates at a depth into the
outer surface and forms an indicia. The at least one sublimating
ink preferably includes at least one of an azo dye, a
nitroarylamine dye, or an anthraquinone dye. U.S. Patent
Publication No. 2003/0106442, the entire disclosure of which is
incorporated by reference herein.
[0255] Laser marking of a selected surface portion of a golf ball
causing the laser light-irradiated portion to change color is also
contemplated for use with the present invention. U.S. Pat. Nos.
5,248,878 and 6,075,223 generally disclose such methods, the entire
disclosures of which are incorporated by reference herein. In
addition, the golf balls may be subjected to ablation, i.e.,
directing a beam of laser radiation onto a portion of the cover,
irradiating the cover portion, wherein the irradiated cover portion
is ablated to form a detectable mark, wherein no significant
discoloration of the cover portion results therefrom. Ablation is
discussed in U.S. Pat. No. 6,462,303, which is incorporated in its
entirety by reference herein.
[0256] Protective and decorative coating materials, as well as
methods of applying such materials to the surface of a golf ball
cover are well known in the golf ball art. Generally, such coating
materials comprise urethanes, urethane hybrids, epoxies, polyesters
and acrylics. If desired, more than one coating layer can be used.
The coating layer(s) may be applied by any suitable method known to
those of ordinary skill in the art. In one embodiment, the coating
layer(s) is applied to the golf ball cover by an in-mold coating
process, such as described in U.S. Pat. No. 5,849,168, which is
incorporated in its entirety by reference herein.
[0257] The use of the polyurea-based and polyurethane-based
compositions in golf equipment may reduce, or completely obviate,
the need for typical post-processing, e.g., coating a golf ball
with a pigmented coating prior to applying a clear topcoat to the
ball. Unlike compositions with no light stable properties, the
compositions used in forming the golf equipment of the present
invention do not discolor upon exposure to light (especially in the
case of extended exposure). Also, by eliminating at least one
coating step, the manufacturer realizes economic benefits in terms
of reduced process times and consequent improved labor efficiency.
Further, significant reduction in volatile organic compounds
("VOCs"), typical constituents of paint, may be realized through
the use of the present invention, offering significant
environmental benefits.
[0258] Thus, while it may not be necessary to use pigmented coating
on the golf balls of the present invention when formed with the
compositions of the invention, the golf balls of the present
invention may be painted, coated, or surface treated for further
benefits. For example, the value of golf balls made according to
the invention and painted offer enhanced color stability as
degradation of the surface paint occurs during the normal course of
play. The mainstream technique used nowadays for highlighting
whiteness is to form a cover toned white with titanium dioxide,
subjecting the cover to such surface treatment as corona treatment,
plasma treatment, UV treatment, flame treatment, or electron beam
treatment, and applying one or more layers of clear paint, which
may contain a fluorescent whitening agent. This technique is
productive and cost effective.
Golf Ball Properties
[0259] The properties such as hardness, modulus, core diameter,
intermediate layer thickness and cover layer thickness of the golf
balls of the present invention have been found to effect play
characteristics such as spin, initial velocity and feel of the
present golf balls. For example, the flexural and/or tensile
modulus of the intermediate layer are believed to have an effect on
the "feel" of the golf balls of the present invention. It should be
understood that the ranges herein are meant to be intermixed with
each other, i.e., the low end of one range may be combined with a
high end of another range.
Component Dimensions
[0260] Dimensions of golf ball components, i.e., thickness and
diameter, may vary depending on the desired properties. For the
purposes of the invention, any layer thickness may be employed.
Non-limiting examples of the various embodiments outlined above are
provided here with respect to layer dimensions.
[0261] The present invention relates to golf balls of any size.
While USGA specifications limit the size of a competition golf ball
to more than 1.68 inches in diameter, golf balls of any size can be
used for leisure golf play. The preferred diameter of the golf
balls is from about 1.68 inches to about 1.8 inches. The more
preferred diameter is from about 1.68 inches to about 1.76 inches.
A diameter of from about 1.68 inches to about 1.74 inches is most
preferred, however diameters anywhere in the range of from 1.7 to
about 1.95 inches can be used. Preferably, the overall diameter of
the core and all intermediate layers is about 80 percent to about
98 percent of the overall diameter of the finished ball.
[0262] The core may have a diameter ranging from about 0.09 inches
to about 1.65 inches. In one embodiment, the diameter of the core
of the present invention is about 1.2 inches to about 1.630 inches.
In another embodiment, the diameter of the core is about 1.3 inches
to about 1.6 inches, preferably from about 1.39 inches to about 1.6
inches, and more preferably from about 1.5 inches to about 1.6
inches. In yet another embodiment, the core has a diameter of about
1.55 inches to about 1.65 inches.
[0263] The core of the golf ball may also be extremely large in
relation to the rest of the ball. For example, in one embodiment,
the core makes up about 90 percent to about 98 percent of the ball,
preferably about 94 percent to about 96 percent of the ball. In
this embodiment, the diameter of the core is preferably about 1.54
inches or greater, preferably about 1.55 inches or greater. In one
embodiment, the core diameter is about 1.59 inches or greater. In
another embodiment, the diameter of the core is about 1.64 inches
or less.
[0264] When the core includes an inner core layer and an outer core
layer, the inner core layer is preferably about 0.9 inches or
greater and the outer core layer preferably has a thickness of
about 0.1 inches or greater. In one embodiment, the inner core
layer has a diameter from about 0.09 inches to about 1.2 inches and
the outer core layer has a thickness from about 0.1 inches to about
0.8 inches. In yet another embodiment, the inner core layer
diameter is from about 0.095 inches to about 1.1 inches and the
outer core layer has a thickness of about 0.20 inches to about 0.03
inches.
[0265] The cover typically has a thickness to provide sufficient
strength, good performance characteristics, and durability. In one
embodiment, the cover thickness is from about 0.02 inches to about
0.35 inches. The cover preferably has a thickness of about 0.02
inches to about 0.12 inches, preferably about 0.1 inches or less.
When the compositions of the invention are used to form the outer
cover of a golf ball, the cover may have a thickness of about 0.1
inches or less, preferably about 0.07 inches or less. In one
embodiment, the outer cover has a thickness from about 0.02 inches
to about 0.07 inches. In another embodiment, the cover thickness is
about 0.05 inches or less, preferably from about 0.02 inches to
about 0.05 inches. In yet another embodiment, the outer cover layer
of such a golf ball is between about 0.02 inches and about 0.045
inches. In still another embodiment, the outer cover layer is about
0.025 to about 0.04 inches thick. In one embodiment, the outer
cover layer is about 0.03 inches thick.
[0266] The range of thicknesses for an intermediate layer of a golf
ball is large because of the vast possibilities when using an
intermediate layer, i.e., as an outer core layer, an inner cover
layer, a wound layer, a moisture/vapor barrier layer. When used in
a golf ball of the invention, the intermediate layer, or inner
cover layer, may have a thickness about 0.3 inches or less. In one
embodiment, the thickness of the intermediate layer is from about
0.002 inches to about 0.1 inches, preferably about 0.01 inches or
greater. In one embodiment, the thickness of the intermediate layer
is about 0.09 inches or less, preferably about 0.06 inches or less.
In another embodiment, the intermediate layer thickness is about
0.05 inches or less, more preferably about 0.01 inches to about
0.045 inches. In one embodiment, the intermediate layer, thickness
is about 0.02 inches to about 0.04 inches. In another embodiment,
the intermediate layer thickness is from about 0.025 inches to
about 0.035 inches. In yet another embodiment, the thickness of the
intermediate layer is about 0.035 inches thick. In still another
embodiment, the inner cover layer is from about 0.03 inches to
about 0.035 inches thick. Varying combinations of these ranges of
thickness for the intermediate and outer cover layers may be used
in combination with other embodiments described herein.
[0267] The ratio of the thickness of the intermediate layer to the
outer cover layer is preferably about 10 or less, preferably from
about 3 or less. In another embodiment, the ratio of the thickness
of the intermediate layer to the outer cover layer is about 1 or
less. The core and intermediate layer(s) together form an inner
ball preferably having a diameter of about 1.48 inches or greater
for a 1.68-inch ball. In one embodiment, the inner ball of a
1.68-inch ball has a diameter of about 1.52 inches or greater. In
another embodiment, the inner ball of a 1.68-inch ball has a
diameter of about 1.66 inches or less. In yet another embodiment, a
1.72-inch (or more) ball has an inner ball diameter of about 1.50
inches or greater. In still another embodiment, the diameter of the
inner ball for a 1.72-inch ball is about 1.70 inches or less.
Hardness
[0268] Most golf balls consist of layers having different
hardnesses, e.g., hardness gradients, to achieve desired
performance characteristics. The present invention contemplates
golf balls having hardness gradients between layers, as well as
those golf balls with layers having the same hardness.
[0269] It should be understood, especially to one of ordinary skill
in the art, that there is a fundamental difference between
"material hardness" and "hardness, as measured directly on a golf
ball." Material hardness is defined by the procedure set forth in
ASTM-D2240 and generally involves measuring the hardness of a flat
"slab" or "button" formed of the material of which the hardness is
to be measured. Hardness, when measured directly on a golf ball (or
other spherical surface) is a completely different measurement and,
therefore, results in a different hardness value. This difference
results from a number of factors including, but not limited to,
ball construction (i.e., core type, number of core and/or cover
layers, etc.), ball (or sphere) diameter, and the material
composition of adjacent layers. It should also be understood that
the two measurement techniques are not linearly related and,
therefore, one hardness value cannot easily be correlated to the
other.
[0270] The cores of the present invention may have varying
hardnesses depending on the particular golf ball construction. In
one embodiment, the core hardness is at least about 15 Shore A,
preferably about 30 Shore A, as measured on a formed sphere. In
another embodiment, the core has a hardness of about 50 Shore A to
about 90 Shore D. In yet another embodiment, the hardness of the
core is about 80 Shore D or less. Preferably, the core has a
hardness about 30 to about 65 Shore D, and more preferably, the
core has a hardness about 35 to about 60 Shore D.
[0271] The intermediate layer(s) of the present invention may also
vary in hardness depending on the specific construction of the
ball. In one embodiment, the hardness of the intermediate layer is
about 30 Shore D or greater. In another embodiment, the hardness of
the intermediate layer is about 90 Shore D or less, preferably
about 80 Shore D or less, and more preferably about 70 Shore D or
less. In yet another embodiment, the hardness of the intermediate
layer is about 50 Shore D or greater, preferably about 55 Shore D
or greater. In one embodiment, the intermediate layer hardness is
from about 55 Shore D to about 65 Shore D. The intermediate layer
may also be about 65 Shore D or greater.
[0272] When the intermediate layer is intended to be harder than
the core layer, the ratio of the intermediate layer hardness to the
core hardness preferably about 2 or less. In one embodiment, the
ratio is about 1.8 or less. In yet another embodiment, the ratio is
about 1.3 or less.
[0273] As with the core and intermediate layers, the cover hardness
may vary depending on the construction and desired characteristics
of the golf ball. The ratio of cover hardness to inner ball
hardness is a primary variable used to control the aerodynamics of
a ball and, in particular, the spin of a ball. In general, the
harder the inner ball, the greater the driver spin and the softer
the cover, the greater the driver spin.
[0274] For example, when the intermediate layer is intended to be
the hardest point in the ball, e.g., about 50 Shore D to about 75
Shore D, the cover material may have a hardness of about 20 Shore D
or greater, preferably about 25 Shore D or greater, and more
preferably about 30 Shore D or greater, as measured on the slab. In
another embodiment, the cover itself has a hardness of about 30
Shore D or greater. In particular, the cover may be from about 30
Shore D to about 70 Shore D. In one embodiment, the cover has a
hardness of about 40 Shore D to about 65 Shore D, and in another
embodiment, about 40 Shore to about 55 Shore D. In another aspect
of the invention, the cover has a hardness less than about 45 Shore
D, preferably less than about 40 Shore D, and more preferably about
25 Shore D to about 40 Shore D. In one embodiment, the cover has a
hardness from about 30 Shore D to about 40 Shore D.
[0275] In this embodiment when the outer cover layer is softer than
the intermediate layer or inner cover layer, the ratio of the Shore
D hardness of the outer cover material to the intermediate layer
material is about 0.8 or less, preferably about 0.75 or less, and
more preferably about 0.7 or less. In another embodiment, the ratio
is about 0.5 or less, preferably about 0.45 or less.
[0276] In yet another embodiment, the ratio is about 0.1 or less
when the cover and intermediate layer materials have hardnesses
that are substantially the same. When the hardness differential
between the cover layer and the intermediate layer is not intended
to be as significant, the cover may have a hardness of about 55
Shore D to about 65 Shore D. In this embodiment, the ratio of the
Shore D hardness of the outer cover to the intermediate layer is
about 1.0 or less, preferably about 0.9 or less.
[0277] The cover hardness may also be defined in terms of Shore C.
For example, the cover may have a hardness of about 70 Shore C or
greater, preferably about 80 Shore C or greater.
[0278] In another embodiment, the cover has a hardness of about 95
Shore C or less, preferably about 90 Shore C or less.
[0279] In another embodiment, the cover layer is harder than the
intermediate layer. In this design, the ratio of Shore D hardness
of the cover layer to the intermediate layer is about 1.33 or less,
preferably from about 1.14 or less.
[0280] When a two-piece ball is constructed, the core may be softer
than the outer cover. For example, the core hardness may range from
about 30 Shore D to about 50 Shore D, and the cover hardness may be
from about 50 Shore D to about 80 Shore D. In this type of
construction, the ratio between the cover hardness and the core
hardness is preferably about 1.75 or less. In another embodiment,
the ratio is about 1.55 or less. Depending on the materials, for
example, if a composition of the invention is acid-functionalized
wherein the acid groups are at least partially neutralized, the
hardness ratio of the cover to core is preferably about 1.25 or
less.
Compression
[0281] Compression values are dependent on the diameter of the
component being measured. The Atti compression of the core, or
portion of the core, of golf balls prepared according to the
invention is preferably less than about 80, more preferably less
than about 75. As used herein, the terms "Atti compression" or
"compression" are defined as the deflection of an object or
material relative to the deflection of a calibrated spring, as
measured with an Atti Compression Gauge, that is commercially
available from Atti Engineering Corp. of Union City, N.J. Atti
compression is typically used to measure the compression of a golf
ball. In another embodiment, the core compression is from about 40
to about 80, preferably from about 50 to about 70. In yet another
embodiment, the core compression is preferably below about 50, and
more preferably below about 25.
[0282] In an alternative, low compression embodiment, the core has
a compression less than about 20, more preferably less than about
10, and most preferably, 0. As known to those of ordinary skill in
the art, however, the cores generated according to the present
invention may, be below the measurement of the Atti Compression
Gauge.
[0283] In one embodiment, golf balls of the invention preferably
have an Atti compression of about 55 or greater, preferably from
about 60 to about 120. In another embodiment, the Atti compression
of the golf balls of the invention is at least about 40, preferably
from about 50 to 120, and more preferably from about 60 to 100. In
yet another embodiment, the compression of the golf balls of the
invention is about 75 or greater and about 95 or less. For example,
a preferred golf ball of the invention may have a compression from
about 80 to about 95.
Initial Velocity and COR
[0284] There is currently no USGA limit on the COR of a golf ball,
but the initial velocity of the golf ball cannot exceed 250.+-.5
feet/second (ft/s). Thus, in one embodiment, the initial velocity
is about 245 ft/s or greater and about 255 ft/s or greater. In
another embodiment, the initial velocity is about 250 ft/s or
greater. In one embodiment, the initial velocity is about 253 ft/s
to about 254 ft/s. In yet another embodiment, the initial velocity
is about 255 ft/s. While the current rules on initial velocity
require that golf ball manufacturers stay within the limit, one of
ordinary skill in the art would appreciate that the golf ball of
the invention would readily convert into a golf ball with initial
velocity outside of this range.
[0285] As a result, of the initial velocity limitation set forth by
the USGA, the goal is to maximize COR without violating the 255
ft/s limit. The COR of a ball is measured by taking the ratio of
the outbound or rebound velocity to the incoming or inbound
velocity. In a one-piece solid golf ball, the COR will depend on a
variety of characteristics of the ball, including its composition
and hardness. For a given composition, COR will generally increase
as hardness is increased. In a two-piece solid golf ball, e.g., a
core and a cover, one of the purposes of the cover is to produce a
gain in COR over that of the core. When the contribution of the
core to high COR is substantial, a lesser contribution is required
from the cover. Similarly, when the cover contributes substantially
to high COR of the ball, a lesser contribution is needed from the
core.
[0286] The present invention contemplates golf balls having CORs
from about 0.700 to about 0.850 at an inbound velocity of about 125
ft/sec. In one embodiment, the COR is about 0.750 or greater,
preferably about 0.780 or greater. In another embodiment, the ball
has a COR of about 0.800 or greater. In yet another embodiment, the
COR of the balls of the invention is about 0.800 to about
0.815.
[0287] In addition, the inner ball preferably has a COR of about
0.780 or more. In one embodiment, the COR is about 0.790 or
greater.
Spin Rate
[0288] As known to those of ordinary skill in the art, the spin
rate of a golf ball will vary depending on the golf ball
construction. In a multilayer ball, e.g., a core, an intermediate
layer, and a cover, wherein the cover is formed from the polytirea
or polyurethane compositions of the invention, the spin rate of the
ball off a driver ("driver spin rate") is preferably about 2700 rpm
or greater. In one embodiment, the driver spin rate is about 2800
rpm to about 3500 rpm. In another embodiment, the driver spin rate
is about 2900 rpm to about 3400 rpm. In still another embodiment,
the driver spin rate may be less than about 2700 rpm.
[0289] Two-piece balls made according to the invention may also
have driver spin rates of 2700 rpm and greater. In one embodiment,
the driver spin rate is about 2700 rpm to about 3300 rpm. Wound
balls made according to the invention may have similar spin
rates.
[0290] Methods of determining the spin rate should be well
understood by those of ordinary skill in the art. Examples of
methods for determining the spin rate are disclosed in U.S. Pat.
Nos. 6,500,073, 6,488,591, 6,286,364, and 6,241,622, which are
incorporated by reference herein in their entirety.
Flexural Modulus
[0291] Accordingly, it is preferable that the golf balls of the
present invention have an intermediate layer with a flexural
modulus of about 500 psi to about 500,000 psi. More preferably, the
flexural modulus of the intermediate layer is about 1,000 psi to
about 250,000 psi. Most preferably, the flexural modulus of the
intermediate layer is about 2,000 psi to about 200,000 psi.
[0292] The flexural modulus of the cover layer is preferably about
2,000 psi or greater, and more preferably about 5,000 psi or
greater. In one embodiment, the flexural modulus of the cover is
from about 10,000 psi to about 150,000 psi. More preferably, the
flexural modulus of the cover layer is about 15,000 psi to about
120,000 psi. Most preferably, the flexural modulus of the cover
layer is about 18,000 psi to about 110,000 psi. In another
embodiment, the flexural modulus of the cover layer is about
100,000 psi or less, preferably about 80,000 or less, and more
preferably about 70,000 psi or less. For example, the flexural
modulus of the cover layer may be from about 10,000 psi to about
70,000 psi, from about 12,000 psi to about 60,000 psi, or from
about 14,000 psi to about 50,000 psi.
[0293] In one embodiment, when the cover layer has a hardness of
about 50 Shore D to about 60 Shore D, the cover layer preferably
has a flexural modulus of about 55,000 psi to about 65,000 psi.
[0294] In one embodiment, the ratio of the flexural modulus of the
intermediate layer to the cover layer is about 0.003 to about 50.
In another embodiment, the ratio of the flexural modulus of the
intermediate layer to the cover layer is about 0.006 to about 4.5.
In yet another embodiment, the ratio of the flexural modulus of the
intermediate layer to the cover layer is about 0.11 to about
4.5.
[0295] In one embodiment, the compositions of the invention are
used in a golf ball with multiple cover layers having essentially
the same hardness, but differences in flexural moduli. In this
aspect of the invention, the difference between the flexural moduli
of the two cover layers is preferably about 5,000 psi or less. In
another embodiment, the difference in flexural moduli is about 500
psi or greater. In yet another embodiment, the difference in the
flexural moduli between the two cover layers, wherein at least one
is reinforced is about 500 psi to about 10,000 psi, preferably from
about 500 psi to about 5,000 psi. In one embodiment, the difference
in flexural moduli between the two cover layers formed of
unreinforced or unmodified materials is about 1,000 psi to about
2,500 psi.
Specific Gravity
[0296] The specific gravity of a cover or intermediate layer is
preferably at least about 0.7. In one embodiment, the specific
gravity of the intermediate layer or cover is about 0.8 or greater,
preferably about 0.9 or greater. For example, in one embodiment,
the golf ball has an intermediate layer with a specific gravity of
about 0.9 or greater and a cover having a specific gravity of about
0.95 or greater. In another embodiment, the intermediate layer or
cover has a specific-gravity of about 1.00 or greater. In yet
another embodiment, the specific gravity of the intermediate layer
or cover is about 1.05 or greater, preferably about 1.10 or
greater.
[0297] The core may have a specific gravity of about 1.00 or
greater, preferably 1.05 or greater. For example, a golf ball of
the invention may have a core with a specific gravity of about 1.10
or greater and a cover with a specific gravity of about 0.95 or
greater.
Adhesion Strength
[0298] The adhesion, or peel, strength of the compositions of the
invention is preferably about 5 lb.sub.f/in or greater. In one
embodiment, the adhesion strength is about 25 lb.sub.f/in or less.
For example, the adhesion strength is preferably about 10
lb.sub.f/in or more and about 20 lb.sub.f/in or less. In another
embodiment, the adhesion strength is about 20 lb.sub.f/in or
greater, preferably about 24 lb.sub.f/in or greater. In yet another
embodiment, the adhesion strength is about 26 lb.sub.f/in or
greater. In still another embodiment, the adhesion strength is
about 20 lb.sub.f/in to about 30 lb.sub.f/in.
[0299] Skilled artisans are aware of methods to determine adhesion
strength. For example, cross-hatch tests and repeated ball impact
tests are useful to determine the adhesion strength of a particular
layer of a golf ball. The cross-hatch test consists of cutting the
material into small pieces in mutually perpendicular directions,
applying a piece of adhesive cellophane tape over the material,
rapidly pulling off the tape, and counting the number of pieces
removed. The repeated impact test consists of subjecting the
finished golf ball to impact repeatedly and visually examining the
coating film for peeling from the golf ball. Examples of these
methods are provided in U.S. Pat. No. 5,316,730, which is
incorporated by reference herein.
Moisture Vapor Transmission
[0300] The moisture vapor transmission of a golf ball portion
formed from the compositions of the invention may be expressed in
terms of absorption, e.g., weight gain or size gain over a period
of time at a specific conditions, and transmission, e.g., moisture
vapor transmission rate (MVTR) according to ASTM E96-00. MVTR
refers to the mass of water vapor that diffused into a material of
a given thickness per unit area per unit time at a specific
temperature and humidity differential. For example, weight changes
of a golf ball portion monitored over a period of seven weeks in
100 percent relative humidity and 72.degree. F. help to demonstrate
which balls have better water resistance. In one embodiment, the
golf ball portions of the invention have a weight gain of about
0.15 grams or less after seven weeks. In another embodiment, the
golf balls of the invention have a weight gain of about 0.13 grams
or less after a seven-week storage period. In still another
embodiment, the weight gain of the golf balls of the invention is
about 0.09 grams or less after seven weeks. In yet another
embodiment, the weight gain is about 0.06 grams or less after a
seven-week period. The golf balls of the invention preferably have
a weight gain of about 0.03 grams or less over a seven-week storage
period.
[0301] Size gain may also be used as an indicator of water
resistance. That is, the more water a golf ball takes on, the
larger a golf ball becomes due to the water enclosed beneath the
outermost layer of the golf ball portion. Thus, the golf balls of
the invention preferably have no appreciable size gain. In one
embodiment, the size gain of the golf balls of the invention after
a seven-week period is about 0.001 inches or less.
[0302] MVTR of a golf ball, or portion thereof, may be about 2
g/(m.sup.2.times.day) or less, such as about 0.45 to about 0.95
g/(m.sup.2.times.day), about 0.01 to about 0.9 g/(m 2.times.day) or
less, at 38.degree. C. and 90 percent relative humidity.
Shear/Cut Resistance
[0303] The cut resistance of a golf ball cover may be determined
using a shear test having a scale from 1 to 9 assessing damage and
appearance. In one embodiment, the damage rank is preferably about
3 or less, more preferably about 2 or less. In another embodiment,
the damage rank is about 1 or less. The appearance rank of a golf
ball of the invention is preferably about 3 or less. In one
embodiment, the appearance rank is about 2 or less, preferably
about 1 or less.
Light Stability
[0304] The light stability of the cover may be quantified by the
difference in yellowness index (.DELTA.YI), i.e., yellowness
measured after a predetermined exposure time--yellowness before
exposure. In one embodiment, the .DELTA.YI is about 10 or less
after 5 days (120 hours) of exposure, preferably about 6 or less
after 5 days of exposure, and more preferably about 4 or less after
5 days of exposure. In one embodiment, the .DELTA.YI is about 2 or
less after 5 days of exposure, and more preferably about 1 or less
after 5 days of exposure. The difference in the b chroma dimension
(.DELTA.b*, yellow to blue) is also a way to quantify the light
stability of the cover. In one embodiment, the .DELTA.b* is about 4
or less after 5 days (120 hours) of exposure, preferably about 3 or
less after 5 days of exposure, and more preferably about 2 or less
after 5 days of exposure. In one embodiment, the .DELTA.b* is about
1 or less after 5 days of exposure.
EXAMPLES
[0305] The following non-limiting examples are merely illustrative
of the preferred embodiments of the present invention, and are not
to be construed as limiting the invention, the scope of which is
defined by the appended claims. Parts are by weight unless
otherwise indicated.
Example 1
Saturated Polyurethane Golf Ball Cover
[0306] Table 3 illustrates the components used to make a saturated
polyurethane golf ball cover composition.
TABLE-US-00001 TABLE 3 COMPOSITION Chemicals Weight (g) H.sub.12MDI
Prepolymer* 458.73 1,4-Butanediol 42.75 HCC-19584 Color
Dispersion** 17.55 *Prepolymer is the reaction product of
4,4'-dicyclohexylmethane diisocyanate and polytetramethylene ether
glycol. **HCC-19584 is a white-blue color dispersion manufactured
by the PolyOne Corporation (formerly the Harwick Chemical
Corporation)
[0307] A golf ball was made having the cover formulated from the
composition above following the teachings of U.S. Pat. No.
5,733,428. The physical properties and the ball performance results
are listed in Table 4.
TABLE-US-00002 TABLE 4 PHYSICAL PROPERTIES Physical Properties
Present Invention Cover Hardness 54 Weight (g) 45.58 Compression 89
Shear Resistance Good Color Stability Comparable to SURLYN
.RTM.
The molded balls from the above composition listed in Table 4 were
further subject to a QUV test as described below:
Method:
[0308] ASTM G 53-88 "Standard Practice for Operating Light and
Water-Exposure Apparatus (Fluorescent UV-Condensation Type) for
Exposure of Nonmetallic Materials" was followed with certain
modifications as described below:
[0309] Six balls of each variety under evaluation were placed in
custom made golf ball holders and inserted into the sample rack of
a Q-PANEL model OUV/SER Accelerated Weathering Tester manufactured
by Q-Panel Lab Products of Cleveland, Ohio. The sample holders were
constructed such that each ball was approximately 1.75 inches from
an UVA-340 bulb, at its closest point. The weathering tester was
then cycled every four hours between the following two sets of
conditions (for the specified total length of time 24, 48, and 120
hours): [0310] Condition #1: water bath temperature of about
50.degree. C. with the UV lamps on, set and controlled at an
irradiance power of 1.00 W/m.sup.2/nm. [0311] Condition #2: water
bath temperature of about 40.degree. C. with the UV lamps turned
off. Color was measured before weathering and after each time cycle
using a BYK-Gardner Model TCS II sphere type Spectrophotometer
equipped with 25-mm port. A D65/10.degree. illumination was used in
the specular reflectance included mode.
[0312] The test results for the molded balls after 24 hours of UV
exposure are tabulated in Table 5, wherein .DELTA.L* equals the
difference in L dimension (light to dark), .DELTA.a* equals the
difference in the a chroma dimension (red to green), .DELTA.b*
equals the difference in the b chroma dimension (yellow to blue),
.DELTA.C* equals the combined chroma difference (a* and b* scales),
hue and saturation, .DELTA.H* equals the total hue difference,
excluding effects of saturation and luminescence, .DELTA.E* equals
the total color difference, .DELTA.WI equals the difference in the
whiteness index, and .DELTA.YI and the difference in the yellowness
index.
TABLE-US-00003 TABLE 5 UV STABILITY DATA .DELTA.WI .DELTA.YI Sample
.DELTA.L* .DELTA.a* .DELTA.b* .DELTA.C* .DELTA.H* .DELTA.E* (E313)
(D1925) Molded Aliphatic -0.21 -0.30 1.54 -1.26 -0.94 1.58 -9.07
2.99 Polyurethane Molded Aromatic -17.27 11.36 46.14 47.31 4.36
50.56 -142.35 93.80 Polyurethane Molded -0.39 -0.25 0.91 -0.76
-0.55 1.02 -6.19 1.69 SURLYN .RTM.
[0313] The test results for the molded balls after 48 hours of UV
exposure are illustrated in Table 6.
TABLE-US-00004 TABLE 6 UV STABILITY DATA .DELTA.WI .DELTA.YI Sample
.DELTA.L* .DELTA.a* .DELTA.b* .DELTA.C* .DELTA.H* .DELTA.E* (E313)
(D1925) Molded Aliphatic -0.48 -0.37 2.54 -2.02 -1.59 2.61 -15.16
4.98 Polyurethane Molded Aromatic -23.46 15.01 42.75 45.18 3.44
51.02 -127.75 98.96 Polyurethane Molded -0.54 -0.39 1.43 -1.18
-0.91 1.58 -9.50 2.66 SURLYN .RTM.
[0314] The test results for the molded balls after 120 hours of UV
exposure are illustrated in Table 7.
TABLE-US-00005 TABLE 7 UV STABILITY DATA .DELTA.WI .DELTA.YI Sample
.DELTA.L* .DELTA.a* .DELTA.b* .DELTA.C* .DELTA.H* .DELTA.E* (E313)
(D1925) Molded Aliphatic -0.92 -0.46 5.87 -3.01 -5.06 5.96 -33.72
11.68 Polyurethane Molded Aromatic -30.06 16.80 33.37 37.29 2.11
47.95 -107.12 94.42 Polyurethane Molded -0.99 -0.85 4.06 -2.91
-2.96 4.26 -24.88 7.73 SURLYN .RTM.
Example 2
H.sub.12 MDI Polyether Urea Cured with Diol
[0315] A golf ball was made having the cover formulated from a
composition including a prepolymer formed of H.sub.12MDI and
polyoxyalkylene, having a molecular weight of about 2000, cured
with 1,4-butanediol. The physical properties and the ball
performance results are listed in Table 8. A golf ball similar to
Example 1, a light stable, aliphatic polyurethane, was used for
comparison purposes.
TABLE-US-00006 TABLE 8 PHYSICAL PROPERTIES Ball Types Aliphatic
Polyurethane Ball Properties Control Invention Nameplate Average
1.686 1.684 Equator Average 1.684 1.683 Weight Average, oz 1.599
1.595 Compression Average 86 86 COR @ 125 ft/sec 0.807 0.805 Cold
Crack Test, 5.degree. F. no failure no failure Light Stability (5
Days QUV Test) .DELTA.YI 3.2 0.8 .DELTA.b* 1.7 0.4 Live Golfer
Shear Test* Damage Rank 3 2 Appearance Rank 3 2 *Rating of Shear
Test: Based on a scale of 1-9, 1 is the best, 9 is the worst.
Example 3
H.sub.12MDI Polyether Urea Cured with a Diamine
[0316] A golf ball was made having the cover formulated from a
composition including a prepolymer formed of H.sub.12MDI and
polyoxyalkylene, having a molecular weight of about 2000, cured
with 4,4'-bis-(sec-butylamino)-dicyclohexylmethane (Clearlink
1000). The physical properties and the ball performance results are
listed in Table 9. A golf ball similar to Example 1, a light
stable, aliphatic polyurethane, was used for comparison
purposes.
TABLE-US-00007 TABLE 9 PHYSICAL PROPERTIES Ball Types Light Stable
Ball Properties Polyurethane Control Invention Nameplate Average
1.683 1.686 Equator Average 1.681 1.684 Weight Average, oz 1.597
1.600 Compression Average 89 92 COR @ 125 ft/sec 0.807 0.815 Cold
Crack Test, 5.degree. F. no failure no failure Light Stability (5
Days QUV Test) .DELTA.YI 4.3 0.6 .DELTA.b* 2.4 0.3 Live Golfer
Shear Test* Damage Rank 3 1 Appearance Rank 3 1 *Rating of Shear
Test: Based on a scale of 1-9, 1 is the best, 9 is the worst.
Example 4
H.sub.12MDI Amine-Terminated Compound Urea Cured with a Diamine
[0317] A golf ball according to the invention may be made having a
cover formed from a composition including a prepolymer formed of
H.sub.12MDI and an amine-terminated compound, such as
amine-terminated polybutadiene, cured with
N,N'-diisopropyl-isophorone diamine (JEFFLINK.RTM. 754, available
from Huntsman Corporation). The physical properties and the ball
performance results are listed in Table 9. A control golf ball
similar to Example 1, a light stable, aliphatic polyurethane, may
be used for comparison purposes. The golf ball of the invention,
when compared to the control ball, preferably has a better damage
rank and appearance rank, as well as improved light stability after
a 5-day QUV test, while still maintaining a higher COR.
Example 5
Moisture Resistance of Invention Golf Balls
[0318] The moisture resistance of a golf ball of the invention was
measured as compared to a control golf ball. The cover for the
invention golf ball was formed from a composition including a
prepolymer of MDI and hydroxy terminated polybutadiene prepolymer
cured with 4,4-bis-(secbutylamino) diphenylmethane (UNILINK.RTM.
4200, available as from Huntsman Corporation).
[0319] The covers were molded on 1.580 inches wound balls, and were
finished with a conventional coating. The golf balls were incubated
in a 50 percent relative humidity and 72.degree. F. environmental
chamber for one week, and then weighed and measured. These
conditioned balls of the invention were then subjected to a 100
percent relative humidity and 72.degree. F. environmental chamber.
Weight and size changes were monitored over a period of 7 weeks.
The results of the tests are tabulated below (Tables 10 and 11) and
illustrated graphically in FIGS. 9 and 10.
TABLE-US-00008 TABLE 10 WEIGHT GAIN(G) OF URETHANE COVERED BALLS
OVER TIME Ball 1 week + 2 weeks + Type 4 days 1 week 5 days 4 days
3 weeks 4 weeks 5 weeks 7 weeks Control +0.06 g +0.08 g +0.09 g
+0.13 g +0.13 g +0.13 g +0.15 g +0.18 g Invention +0.01 g +0.01 g
+0.01 g +0.02 g +0.02 g +0.02 g +0.02 g +0.03 g
TABLE-US-00009 TABLE 11 SIZE GAIN (INCHES) OF URETHANE COVERED
BALLS OVER TIME Ball 1 week + 2 weeks + Type 4 days 1 week 5 days 4
days 3 weeks 4 weeks 5 weeks 7 weeks Control 0 +0.001 in. +0.001
in. +0.001 in. +0.001 in. +0.001 in. +0.001 in. +0.001 in.
Invention 0 0 0 0 0 0 0 0
Example 6
Water Resistant Polyurea-Covered Golf Balls
[0320] Golf balls may be made according to the invention using a
solid core, an intermediate layer, and a cover formed of a water
resistant polyurea composition. In particular, the covers may be
formed from the reaction product of a polyurea prepolymer and a
curing agent.
[0321] The polyurea prepolymer may be formed from an isocyanate,
e.g., H.sub.12MDI, and an amine-terminated compound having a
hydrophobic backbone, e.g., an amine-terminated polybutadiene. The
curing agent may be a secondary diamine, such as
4,4'-bis-(sec-butylamino)-dicyclohexylmethane (UNILINK.RTM. 4200,
available as from Huntsman Corporation),
N,N'-diisopropyl-isophorone diamine (JEFFLINK.RTM. 754, available
from Huntsman Corporation), or mixtures thereof.
[0322] Control balls are preferably formed using the same core and
intermediate layer materials, but using a polyurethane composition
that includes a polyol without a hydrophobic backbone. Both the
invention golf balls and the control golf balls may be incubated in
a 50 percent relative humidity and 72.degree. F. environmental
chamber for one week, and then weighed and measured. These balls
may then be subjected to a 100 percent relative humidity and
72.degree. F. environmental chamber. Weight and size changes may
then be monitored over a period of 7 weeks.
[0323] The water-resistant polyurea-covered golf balls, when
compared to the control balls, will have better water resistance.
For example, the golf balls of the invention may have a weight gain
of about 75 percent less than the control golf balls after seven
weeks, preferably about 80 percent less weight gain than the
control balls. Likewise, the golf balls of the invention preferably
have no size gain after seven weeks, whereas the control golf
balls, as shown above in Example 5, Table 11, have a size gain of
0.001 inches.
Example 6
Golf Balls Formed from Polyurethane-Based Compositions
Incorporating Block Copolymers
[0324] Golf balls may be made according to the invention using a
solid core, an intermediate layer, and a cover formed of a
polyurethane-based composition of the invention incorporating a
block copolymer. In particular, the covers may be formed from the
reaction product of a polyurethane prepolymer, a block copolymer, a
coupling agent, and a curing agent.
[0325] The polyurethane prepolymer may be formed from an
isocyanate, e.g., H.sub.12MDI, and a hydroxy-terminated compound.
The polyurethane prepolymer may be incorporated at the terminal end
of a block copolymer, such as SBS block copolymer, using a coupling
agent. After the prepolymer is coupled with the SBS block
copolymer, the compound may be cured using a hydroxy-terminated
curing agent or an amine-terminated curing agent.
Example 7
Golf Balls Formed from Polyurea-Based Compositions Incorporating
Block Copolymer
[0326] Golf balls may be made according to the invention using a
solid core, an intermediate layer, and a cover formed of a
polyurea-based composition of the invention incorporating a block
copolymer. In particular, the covers may be formed from the
reaction product of a polyurea prepolymer, a block copolymer, a
coupling agent, and a curing agent.
[0327] The polyurea prepolymer may be formed from an isocyanate,
e.g., H.sub.12MDI, and an amine-terminated compound. The polyurea
prepolymer may be incorporated at the terminal end of a block
copolymer, such as SBS block copolymer, using a coupling agent.
After the prepolymer is coupled with the SBS block copolymer, the
compound may be cured using an amine-terminated curing agent, e.g.,
a secondary diamine, such as
4,4'-bis-(sec-butylamino)-dicyclohexylmethane (UNILINK.RTM. 4200,
available as from Huntsman Corporation),
N,N'-diisopropyl-isophorone diamine (JEFFLINK.RTM. 754, available
from Huntsman Corporation), or mixtures thereof.
[0328] The invention described and claimed herein is not to be
limited in scope by the specific embodiments herein disclosed,
since these embodiments are intended as illustrations of several
aspects of the invention. Any equivalent embodiments are intended
to be within the scope of this invention. For example, the
compositions of the invention may also be used in golf equipment
such as putter inserts, golf club heads and portions thereof, golf
shoe portions, and golf bag portions. Indeed, various modifications
of the invention in addition to those shown and described herein
will become apparent to those skilled in the art from the foregoing
description. Such modifications are also intended to fall within
the scope of the appended claims. All patents and patent
applications cited in the foregoing text are expressly incorporate
herein by reference in their entirety.
* * * * *