U.S. patent application number 12/613178 was filed with the patent office on 2011-05-05 for golf balls comprising functionalized polyurethane compositions.
Invention is credited to Kevin M. Harris, Murali Rajagopalan, Michael J. Sullivan.
Application Number | 20110105245 12/613178 |
Document ID | / |
Family ID | 43926025 |
Filed Date | 2011-05-05 |
United States Patent
Application |
20110105245 |
Kind Code |
A1 |
Rajagopalan; Murali ; et
al. |
May 5, 2011 |
GOLF BALLS COMPRISING FUNCTIONALIZED POLYURETHANE COMPOSITIONS
Abstract
Golf balls having at least one layer made from a composition
comprising a functionalized polytrimethylene ether-based
polyurethane are provided. The composition is the reaction product
of a polyisocyanate with polytrimethylene ether glycol and a
hydroxyl and/or amine curing agent wherein at least one of the
isocyanate compound, polytrimethylene ether glycol compound, or
curing agent contains acid, ester, or ionic groups. Blends of
polytrimethylene ether glycol with other glycols such as polyester
glycol, polycaprolactone glycol, or polycarbonate glycol can be
used. The composition can be prepared using prepolymer and one-shot
manufacturing techniques. The composition may be used to form any
layer in the golf ball structure and the resulting golf ball has
improved resiliency and playing performance.
Inventors: |
Rajagopalan; Murali; (South
Dartmouth, MA) ; Sullivan; Michael J.; (Barrington,
RI) ; Harris; Kevin M.; (New Bedford, MA) |
Family ID: |
43926025 |
Appl. No.: |
12/613178 |
Filed: |
November 5, 2009 |
Current U.S.
Class: |
473/373 ;
473/374; 473/376; 473/378 |
Current CPC
Class: |
A63B 37/0031 20130101;
A63B 37/0033 20130101; A63B 37/0062 20130101; A63B 37/02 20130101;
A63B 37/0043 20130101; A63B 37/0003 20130101; A63B 37/0045
20130101; A63B 37/12 20130101; A63B 37/0039 20130101 |
Class at
Publication: |
473/373 ;
473/374; 473/378; 473/376 |
International
Class: |
A63B 37/02 20060101
A63B037/02; A63B 37/12 20060101 A63B037/12 |
Claims
1. A multi-layered golf ball, comprising: a core having a first
Shore D surface hardness of H.sub.1 in the range of about 10 to
about 60; an intermediate layer overlying the core having a second
Shore D surface hardness of H.sub.2 in the range of about 50 to
about 75, the intermediate layer being formed from a functionalized
polytrimethylene ether-based polyurethane or polyurethane/polyurea
hybrid composition that is produced by a reaction of i) an
isocyanate compound, ii) a polytrimethylene ether glycol compound,
and iii) a curing agent selected from the group consisting of
hydroxyl-terminated curing agents, amine-terminated curing agents,
and mixtures thereof, wherein at least one of the isocyanate
compound, polytrimethylene ether glycol compound, or curing agent
contains acid, ester or ionic groups; the intermediate layer having
a thickness in the range of about 0.010 to about 0.040 inches; and
a cover layer overlying the intermediate layer having a third Shore
D surface hardness of H.sub.3 in the range of about 30 to 60,
wherein the ratio of H.sub.3 to H.sub.1 is in the range of about
0.6 to about 6.
2. The golf ball of claim 1, wherein the polytrimethylene ether
glycol compound is a blend of polytrimethylene ether glycol and a
polyester glycol.
3. The golf ball of claim 1, wherein the polytrimethylene ether
glycol compound is a blend of polytrimethylene ether glycol and a
polycaprolactone glycol.
4. The golf ball of claim 1, wherein the polytrimethylene ether
glycol compound is a blend of polytrimethylene ether glycol and a
polyether glycol selected from the group consisting of polyethylene
glycol, poly (1,3-propylene) glycol, polytetramethylene glycol,
copolymers of tetrahydrofuran and ethylene oxide or propylene oxide
glycol, and mixtures thereof.
5. The golf ball of claim 1, wherein the acid, ester, or ionic
groups are derived from the isocyanate compound.
6. The golf ball of claim 1, wherein the acid, ester, or ionic
groups are derived from the polytrimethylene ether glycol
compounds.
7. The golf ball of claim 1, wherein the acid, ester, or ionic
groups are derived from the hydroxyl-terminated curing agents or
amine-terminated curing agents.
8. The golf ball of claim 1, wherein the acid or ester groups are
about 0.5 to about 50 wt % based on the weight of functionalized
polytrimethylene ether-based polyurethane or polyurethane/urea
hybrid composition.
9. The golf ball of claim 8, wherein the acid or ester groups are
selected from carboxylic, sulfonic, or phosphonic acid groups.
10. The golf ball of claim 8, wherein the acid or ester groups are
neutralized by a cation source.
11. The golf ball of claim 10, wherein the acid or ester groups are
neutralized by a cation source such that the acid content of the
composition is neutralized below 80%.
12. The golf ball of claim 10, wherein the acid or ester groups are
neutralized by a cation source such that the acid content of the
composition is neutralized 80% or greater.
13. The golf ball of claim 12, wherein the acid or ester groups are
neutralized by a cation source in the presence of a melt flow
modifier.
14. The golf ball of claim 10, wherein the cation source is a metal
cation selected from the group consisting of lithium, sodium,
potassium, magnesium, calcium, barium, lead, tin, zinc, aluminum,
manganese, nickel, chromium, copper, and combinations thereof.
15. The golf ball of claim 13, wherein the melt flow modifier is a
fatty acid or salt thereof selected from the group consisting of
stearic, behenic, erucic, oleic, lineolic, or dimerized derivatives
thereof.
16. The golf ball of claim 1, wherein the ionic groups are selected
from carboxylate, sulfonate, or phosphonate groups.
17. The golf ball of claim 1, wherein the isocyanate compound is
selected from the group consisting of monomeric or oligomeric or
polymeric MDI, H.sub.12MDI, PPDI, TDI, IPDI, HDI, NDI, XDI, and
TMXDI and their acid or ionic derivatives thereof.
18. The golf ball of claim 1, wherein the curing agent is a
hydroxyl-terminated curing agent selected from the group consisting
of ethylene glycol, diethylene glycol, polyethylene glycol,
propylene glycol, PTMEG, polyethylene propylene glycol,
polyoxypropylene glycol, 2-methyl-1,3-propanediol,
2-methyl-1,4-butanediol, and their acid, ester, or ionic
derivatives thereof.
19. The golf ball of claim 1, wherein the curing agent is an
amine-terminated curing agent selected from the group consisting of
4,4'-diamino-diphenylmethane; 3,5-diethyl-(2,4- or
2,6-)toluenediamine; 3,5-dimethylthio-(2,4- or 2,6-)toluenediamine;
3,5-diethylthio-(2,4- or 2,6-)toluenediamine:
2,2'-dichloro-3,3',5,5'-tetraethyl-4,4'-diamino-diphenylmethane;
polytetramethyleneglycol-di(p-aminobenzoate);
4,4'-bis(sec-butylamino)-dicyclohexylmethane; their acid, ester, or
ionic derivatives thereof.
20. The golf ball of claim 1, wherein the core is a single-piece
core comprising a polybutadiene or a highly neutralized
olefin-based copolymer.
21. The golf ball of claim 1, wherein the core is a multi-layered
core and at least one layer comprises a polybutadiene or a highly
neutralized olefin-based copolymer.
22. The golf ball of claim 1, wherein the cover layer is formed
from a thermoplastic or thermoset composition.
23. The golf ball of claim 22, wherein the thermoplastic
composition is selected from the group consisting of ionomers;
polyesters; polyester-ether elastomers; polyester-ester elastomers;
polyamides; polyamide-ether elastomers, and polyamide-ester
elastomers; polyurethanes, polyureas, and polyurethane-polyurea
hybrids and mixtures thereof.
24. The golf ball of claim 22, wherein the thermoset composition is
selected from the group consisting of polyurethanes, polyureas, and
polyurethane-polyurea hybrids, epoxy and mixtures thereof.
25. A multi-layered golf ball, comprising: a core having a first
Shore D surface hardness of H.sub.1 in the range of about 10 to
about 60; an intermediate layer overlying the core having a second
Shore D surface hardness of H.sub.2 in the range of about 50 to
about 75, a cover layer overlying the intermediate layer having a
third Shore D surface hardness of H.sub.3, the cover layer being
formed from a functionalized polytrimethylene ether-based
polyurethane or polyurethane/urea hybrid composition that is
produced by a reaction of: i) an isocyanate compound, ii) a
polytrimethylene ether glycol compound, and iii) a curing agent
selected from the group consisting of hydroxyl-terminated curing
agents, amine-terminated curing agents, and mixtures thereof,
wherein at least one of the isocyanate compound, polytrimethylene
ether glycol compound, or curing agent contains acid, ester, or
ionic groups; the cover layer having a thickness in the range of
about 0.010 to about 0.030 inches and H.sub.3 being in the range of
about 45 to about 65.
26. A multi-layered golf ball, comprising: a dual core having an
inner core layer and an outer core layer overlying the inner core,
the outer core layer having a thickness in the range of about 0.030
to about 0.070 inches and a Shore D surface hardness in the range
of about 40 to about 70; an intermediate layer overlying the outer
core, the intermediate layer having a thickness in the range of
about 0.010 to about 0.040 inches and a Shore D surface hardness in
the range of about 50 to about 75; a cover layer overlying the
intermediate layer, the cover layer having a thickness in the range
of about 0.010 to about 0.030 inches and a Shore D surface hardness
in the range of about 45 to about 65; wherein at least one of the
outer core, intermediate, or cover layers is formed from a
polytrimethylene ether-based polyurethane or polyurethane/urea
hybrid composition that is produced by a reaction of: i) an
isocyanate compound, ii) a polytrimethylene ether glycol compound,
and iii) a curing agent selected from the group consisting of
hydroxyl-terminated curing agents, amine-terminated curing agents,
and mixtures thereof, wherein at least one of the isocyanate
compound, polytrimethylene ether glycol compound, or curing agent
contains acid, ester, or ionic groups.
27. A triple covered golf ball, comprising: a core; an innermost
cover layer overlying the core having a Shore D surface hardness of
in the range of about 50 to about 75, an intermediate cover layer
and an outer cover layer, wherein at least one of the innermost,
intermediate, or outer cover layer is formed from a
polytrimethylene ether-based polyurethane or polyurethane/urea
hybrid composition that is produced by a reaction of: i) an
isocyanate compound, ii) a polytrimethylene ether glycol compound,
and iii) a curing agent selected from the group consisting of
hydroxyl-terminated curing agents, amine-terminated curing agents,
and mixtures thereof, wherein at least one of the isocyanate
compound, polytrimethylene ether glycol compound, or curing agent
contains acid, ester, or ionic groups; the inner cover layer having
a thickness in the range of about 0.020 to about 0.050 inches and a
Shore D surface hardness in the range of about 50 to about 70 and
the outer cover layer having a thickness in the range of about
0.010 to about 0.030 inches and a Shore D surface hardness in the
range of about 40 to about 60.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to golf balls
containing at least one layer made from a composition comprising a
functionalized thermoplastic or thermoset polyurethane having
ionomer or ionomer precursor moieties such as acids or esters. More
particularly, the layer contains a functionalized polytrimethylene
ether-based polyurethane produced from a reaction of polyisocyanate
with polytrimethylene ether glycol or blends of polytrimethylene
ether glycol with other glycols such as polyester glycol,
polycaprolactone glycol, or polycarbonate glycol; and a curing
agent. At least one of the reactive components contains acid or
ester or ionic groups. The composition may be used to form any
layer in the golf ball structure such as, for example, an outer
core, intermediate layer, inner cover, and/or outer cover. The
resulting golf ball has improved physical properties.
[0003] 2. Brief Review of the Related Art
[0004] Multi-piece solid golf balls having an inner core and outer
cover with an intermediate layer disposed there between are popular
today in the golf industry. The inner core is made commonly of a
rubber material such as natural and synthetic rubbers, styrene
butadiene, polybutadiene, poly(cis-isoprene), or
poly(trans-isoprene). Often, the intermediate layer is made of an
olefin-based ionomer resin that imparts hardness to the ball. These
ionomer acid copolymers contain inter-chain ionic bonding, and are
generally made of an .alpha.-olefin such as ethylene and a vinyl
comonomer having an acid group such as methacrylic, acrylic acid,
or maleic acid. Metal ions such as sodium, lithium, zinc, and
magnesium are used to neutralize the acid groups in the copolymer.
Commercially available olefin-based ionomer resins are used in
different industries and include numerous resins sold under the
trademarks, Surlyn.RTM. (available from DuPont) and Escor.RTM. and
Iotek.RTM. (available from ExxonMobil), Amplify IO.RTM. (available
from Dow Chemical) and Clarix.RTM. (available from A. Schulman).
Olefin-based ionomer resins are available in various grades and
identified based on the type of base resin, molecular weight, and
type of metal ion, amount of acid, degree of neutralization,
additives, and other properties. The outer cover of conventional
golf balls are made from a variety of materials including
olefin-based ionomers, polyamides, polyesters, and thermoplastic
and thermoset polyurethane and polyurea elastomers.
[0005] In recent years, there has been substantial interest in
using thermoset, castable polyurethanes and polyureas to make core,
intermediate, and/or cover layers for the golf balls. Basically,
polyurethane compositions contain urethane linkages formed by
reacting an isocyanate group (--N.dbd.C.dbd.O) with a hydroxyl
group (OH). Polyurethanes are produced by the reaction of a
polyisocyanate with a polyol in the presence of a catalyst and
other additives. The chain length of the polyurethane prepolymer is
extended by reacting it with a hydroxyl-terminated curing agent.
Polyurea compositions, which are distinct from the above-described
polyurethanes, also can be formed. In general, polyurea
compositions contain urea linkages formed by reacting an isocyanate
group (--N.dbd.C.dbd.O) with an amine group (NH or NH.sub.2). The
chain length of the polyurea prepolymer is extended by reacting the
prepolymer with an amine curing agent. Hybrid compositions
containing urethane and urea linkages also may be produced. For
example, a polyurethane/urea hybrid composition may be produced
when a polyurethane prepolymer is reacted with an amine-terminated
curing agent as discussed further below.
[0006] Golf balls made with polyurethane and polyurea materials are
generally described in the patent literature, for example, U.S.
Pat. Nos. 5,334,673; 6,476,176; 6,506,851; 6,867,279; 6,960,630;
and 7,105,623. In particular, polyurethane ionomers are disclosed
in U.S. Pat. Nos. 6,193,207,784; 6,207,784; and 6,610,812 but these
patents do not teach the use of functionalized polytrimethylene
based compositions having acid, ester, or ionic moieties.
[0007] As discussed above, in general, isocyanate compounds with
two or more functional groups are reacted with polyols to form the
polyurethane compositions. There are various isocyanates and
polyols used to manufacture polyurethanes. For example, it is known
that polyurethanes can be prepared using polytrimethylene ether
glycols. For example, Sunkara, U.S. Pat. Nos. 6,852,823; 6,946,539;
and 7,244,810; and U.S. Patent Application Publication Nos. US
2007/0129524 and US 2008/0039582 disclose polytrimethylene
ether-based thermoplastic polyurethane and polyurethane-urea
compositions and their ionomers prepared from: a)
poly(trimethylene-ether) glycol; b) diisocyanate; and c) diol or
diamine chain extender. These patent documents disclose that the
compositions may be used for breathable membranes, synthetic
lubricants, hydraulic fluids, cutting oils, motor oils,
surfactants, spin-finishes, water-borne coatings, laminates,
adhesives, packaging, films and foams, fibers and fabrics. Sunkara
et al., U.S. Patent Application Publication No. US 2005/0256294
disclose using polytrimethylene ether glycol-based polyurethanes in
one or more layers of a golf ball; however, there is no disclosure
of using polyurethane ionomer or ionomer precursors in golf
balls.
[0008] There continues to be interest in developing multi-layered
golf balls containing components or layers that impart high
resiliency to the balls. In general, golf balls having a higher
resiliency tend to have higher initial velocity and retain more
total energy when struck with a club. This allows players to
achieve longer flight distances when hitting the ball off the tee.
In addition, the balls should have relatively high
cut/tear-resistance and impact durability. This helps the balls
appear relatively new even after repeated use. Such balls generally
do not cut, tear, or otherwise damage easily. At the same time, the
golf ball should have a relatively soft feel. In general, golfers
experience a more natural and pleasant feeling when striking such
soft feel golf balls with the club face. The player senses more
control and softer ball covers tend to provide higher initial spin.
This is particularly advantageous to players making approach shots
near the green.
[0009] Golf balls made of new polyurethane ionomer or ionomer
precursor compositions are particularly desirable, because they can
help provide a highly resilient ball with good impact durability
and toughness as well as optimum playing performance properties
such as feel, softness, spin control, and the like. The present
invention provides methods for making such golf balls and the
resultant balls.
SUMMARY OF THE INVENTION
[0010] The present invention relates to multi-layered golf balls
made from a composition comprising a thermoplastic or thermoset
polyurethane ionomer or ionomer precursor. The composition may be
used to form any layer in the golf ball structure such as, for
example, an outer core, intermediate layer, inner cover, and/or
outer cover. The golf balls made of the compositions of this
invention are highly resilient and have good impact durability and
toughness. Moreover, the ball has a soft feel and optimum playing
performance properties.
[0011] In one preferred embodiment, the ball includes a core which
can be made of polybutadiene, highly neutralized polymer, or other
suitable material. The core preferably has Shore D surface hardness
(H.sub.1) in the range of about 10 to about 60. An intermediate
layer surrounds the core and is formed from a functionalized
polytrimethylene ether-based polyurethane or polyurethane/polyurea
hybrid composition. This is the reaction product of: i) an
isocyanate compound, ii) a polytrimethylene ether glycol compound
(or blends of polytrimethylene ether glycol with other glycols such
as polyester glycol, polycaprolactone glycol, or polycarbonate
glycol), and iii) a curing agent selected from the group consisting
of hydroxyl-terminated curing agents, amine-terminated curing
agents, and mixtures thereof, wherein at least one of the
isocyanate compound, polytrimethylene ether glycol compound, or
curing agent contains acid, ester, or ionic groups. The
intermediate layer preferably has a thickness in the range of about
0.010 to about 0.040 inches and a Shore D surface hardness
(H.sub.2) in the range of about 30 to about 75 and more preferably
50 to 75. A cover layer, which may be formed from conventional
materials such as olefin-based ionomers, polyurethanes, polyureas,
polyesters, polyamide-ester elastomers, surrounds the intermediate
layer. The cover layer has a Shore D surface hardness (H.sub.3) in
the range of about 30 to about 60. The ratio of H.sub.3 to H.sub.1
is in the range of about 0.6 to about 6.
[0012] In a second preferred embodiment, the ball includes a core
having a Shore D surface hardness (H.sub.1) in the range of about
10 to about 60 and an intermediate layer having a Shore D surface
hardness (H.sub.2) in the range of about 50 to about 75. There is a
cover layer having a Shore D surface hardness (H.sub.3) in the
range of about 45 to about 65 and a thickness in the range of about
0.010 to about 0.030 inches. The cover layer is formed from the
functionalized polytrimethylene ether-based polyurethane or
polyurethane/polyurea hybrid composition as described above.
[0013] In a third preferred embodiment, the ball includes a dual
core having inner and outer core layers. The outer core has a
thickness in the range of about 0.030 to about 0.070 inches and a
Shore D surface hardness in the range of about 40 to about 70. An
intermediate layer having a thickness in the range of about 0.010
to about 0.040 inches and a Shore D surface hardness in the range
of about 50 to about 75 surrounds the outer core. A cover layer
having a thickness in the range of about 0.010 to about 0.030
inches and a Shore D surface hardness in the range of about 45 to
about 65 surrounds the intermediate layer. At least one of the
outer core, intermediate, or cover layers is formed from the
functionalized polytrimethylene ether-based polyurethane or
polyurethane/polyurea hybrid composition as described above.
[0014] In a fourth preferred embodiment, the ball includes a
triple-layered cover. The ball includes a core and a triple-layered
cover surrounding the core. The innermost cover layer. overlying
the core, has a Shore D surface hardness in the range of about 50
to about 75. Additionally, there are intermediate and outer cover
layers. At least one of the innermost, intermediate, or outer cover
layers is formed from a functionalized polytrimethylene ether-based
polyurethane or polyurethane/polyurea hybrid composition as
described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The novel features that are characteristic of the present
invention are set forth in the appended claims. However, the
preferred embodiments of the invention, together with further
objects and attendant advantages, are best understood by reference
to the following detailed description in connection with the
accompanying drawings in which:
[0016] FIG. 1 is a front view of a dimpled golf ball made in
accordance with the present invention;
[0017] FIG. 2 is a cross-sectional view of a multi-layered
(three-piece) golf ball having an intermediate layer made of a
functionalized polytrimethylene ether-based polyurethane acid,
ester, or ionomer composition in accordance with the present
invention;
[0018] FIG. 3 is a cross-sectional view of a multi-layered
(four-piece) golf ball having an outer core layer made of a
functionalized polytrimethylene ether-based polyurethane acid,
ester, or ionomer composition in accordance with the present
invention;
[0019] FIG. 4 is a cross-sectional view of a multi-layered
(four-piece) golf ball having an inner cover layer made of a
functionalized polytrimethylene ether-based polyurethane acid,
ester, or ionomer composition in accordance with the present
invention; and
[0020] FIG. 5 is a cross-sectional view of a multi-layered
(four-piece) golf ball having a multi-layered core, intermediate
layer, and outer cover layer made in accordance with the present
invention
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The present invention relates generally to golf balls
containing at least one "layer" made from a polytrimethylene
ether-based polyurethane acid, ester, or ionomer. The term, "layer"
as used herein means generally any spherical portion of a golf
ball. The polytrimethylene ether-based polyurethane acid, ester, or
ionomer composition of this invention may be used to form any layer
in the golf ball structure including, but not limited to, an outer
cover, inner cover, intermediate layer, and/or outer core
layer.
[0022] In general, polyurethane compositions contain urethane
linkages formed by reacting an isocyanate group (--N.dbd.C.dbd.O)
with a hydroxyl group (OH). Commercial polyurethanes are produced
by the reaction of a polyisocyanate with a polyalcohol (polyol) in
the presence of a catalyst and other additives. The chain length of
the polyurethane prepolymer is extended by reacting it with a
hydroxyl-terminated curing agent. The resulting polyurethane
polymer has elastomeric properties based on phase separation of its
soft and hard segments. The soft segments, which are formed from
the polyols, are generally flexible, while the hard segments, which
are formed from the isocyanate and chain extenders, are generally
stiff
[0023] In the present invention, a functionalized polytrimethylene
ether-based polyurethane or polyurethane/urea hybrid composition is
produced by a reaction of an isocyanate compound, a
polytrimethylene-ether glycol compound, and a hydroxyl or amine
curing agent. At least one of the reactive components contains
acid, ester, or ionic groups. If the reactive component contains
acid or ester groups, then a polytrimethylene ether-based
polyurethane (or polyurethane/urea hybrid) ionomer precursor is
formed. On the other hand, if the reactive component contains ionic
groups, then a polytrimethylene ether-based polyurethane (or
polyurethane/urea hybrid) ionomer is formed. By the term,
"polytrimethylene ether-based polyurethane and polyurethane/urea
hybrid compositions" it is meant a functionalized polytrimethylene
ether-based polyurethane or polyurethane/urea hybrid composition,
unless otherwise specifically stated herein.
[0024] Isocyanate Compounds
[0025] Any suitable isocyanate known in the art can be used to
produce the polyurethane composition in accordance with this
invention. Such isocyanates include, for example, aliphatic,
cycloaliphatic, aromatic aliphatic, aromatic, any derivatives
thereof, and combinations of these compounds having two or more
isocyanate (--N.dbd.C.dbd.O) groups per molecule. The isocyanates
may be organic polyisocyanate-terminated prepolymers, isocyanate
prepolymers having a low residual amount of unreacted isocyanate
monomer ("low free" isocyanates), and mixtures thereof The
isocyanate-containing reactable component also may 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.
[0026] Preferred isocyanates include diisocyanates (having two NCO
groups per molecule), biurets thereof, dimerized uretdiones
thereof, trimerized isocyanurates thereof, and polyfunctional
isocyanates such as monomeric triisocyanates. Diisocyanates
typically have the generic structure of OCN--R--NCO. Exemplary
diisocyanates include, but are not limited to, unsaturated
isocyanates such as: p-phenylene diisocyanate ("PPDI," i.e.,
1,4-phenylene diisocyanate), m-phenylene diisocyanate ("MPDI,"
i.e., 1,3-phenylene diisocyanate), o-phenylene diisocyanate (i.e.,
1,2-phenylene diisocyanate), 4-chloro-1,3-phenylene diisocyanate,
toluene diisocyanate ("TDI"), m-tetramethylxylene diisocyanate
("m-TMXDI"), p-tetramethylxylene diisocyanate ("p-TMXDI"), 1,2-,
1,3-, and 1,4-xylene diisocyanates, 2,2'-, 2,4'-, and
4,4'-biphenylene diisocyanates, 3,3'-dimethyl-4,4'-biphenylene
diisocyanate ("TODI"), 2,2'-, 2,4'-, and 4,4'-diphenylmethane
diisocyanates ("MDI"), 3,3'-dimethyl-4,4'-diphenylmethane
diisocyanate, carbodiimide-modified MDI, polyphenylene
polymethylene polyisocyanate ("PMDI," i.e., polymeric MDI),
1,5-naphthalene diisocyanate ("NDI"), 1,5-tetrahydronaphththalene
diisocyanate, anthracene diisocyanate, tetracene diisocyanate; and
saturated isocyanates such as: 1,4-tetramethylene diisocyanate,
1,5-pentamethylene diisocyanate, 2-methyl-1,5-pentamethylene
diisocyanate, 1,6-hexamethylene diisocyanate ("HDI") and isomers
thereof, 2,2,4- and 2,4,4-trimethylhexamethylene diisocyanates,
1,7-heptamethylene diisocyanate and isomers thereof,
1,8-octamethylene diisocyanate and isomers thereof,
1,9-nonamethylene diisocyanate and isomers thereof,
1,10-decamethylene diisocyanate and isomers thereof, 1,12-dodecane
diisocyanate and isomer thereof, 1,3-cyclobutane diisocyanate,
1,2-, 1,3-, and 1,4-cyclohexane diisocyanates, 2,4- and
2,6-methylcyclohexane diisocyanates, isophorone diisocyanate
("IPDI"), isocyanatomethylcyclohexane isocyanate,
isocyanatoethylcyclohexane isocyanate, 4,4'-dicyclohexylmethane
diisocyanate ("H.sub.12 MDI," i.e.,
bis(4-isocyanatocyclohexyl)-methane), and 2,4'- and
4,4'-dicyclohexane diisocyanates. Dimerized uretdiones of
diisocyanates and polyisocyanates include, for example, unsaturated
isocyanates such as uretdiones of toluene diisocyanates, uretdiones
of diphenylmethane diisocyanates; and saturated isocyanates such as
uretdiones of hexamethylene diisocyanates. Trimerized isocyanurates
of diisocyanates and polyisocyanates include, for example,
unsaturated isocyanates such as trimers of diphenylmethane
diisocyanate, trimers of tetramethylxylene diisocyanate,
isocyanurates of toluene diisocyanates; and saturated isocyanates
such as isocyanurates of isophorone diisocyanate, isocyanurates of
hexamethylene diisocyanate, isocyanurates of
trimethyl-hexamethylene diisocyanates. Monomeric triisocyanates
include, for example, unsaturated isocyanates such as
2,4,4'-diphenylene triisocyanate, 2,4,4'-diphenylmethane
triisocyanate, 4,4',4''-triphenylmethane triisocyanate; and
saturated isocyanates such as: 1,3,5-cyclohexane triisocyanate.
Preferably, the isocyanate is selected from the group consisting of
MDI, H.sub.12MDI, PPDI, TDI, IPDI, HDI, NDI, XDI, TMXDI, THDI
(trimerized HDI), and TMDI (trimerized MDI), and homopolymers and
copolymers and mixtures thereof.
[0027] Polyol Compounds
[0028] As discussed above, a polyurethane composition is generally
an elastomeric material that is the reaction product of isocyanate
and hydroxyl components. There are many polyol compounds known in
the art. Surprisingly, it has been found that a polyol component
selected from polytrimethylene ether glycol and blends of
polytrimethylene ether glycol with other glycols such as polyester
glycol, polycaprolactone glycol, or acid or ionic functionalized
glycols provides a polyurethane composition having many
advantageous properties for purposes of this invention. The
resulting functionalized polytrimethylene ether-based polyurethane
composition can be used to manufacture golf balls having an optimum
combination of "resiliency" and "softer feel" properties. The
combination of the polytrimethylene ether-based polyurethane and
other materials comprising the core, intermediate layer and/or
cover layer provides a finished ball that can be used to achieve
increased distance. And yet, the golf ball retains a relatively
soft feel. Thus, players can more easily control the play of the
ball.
[0029] By the term, "polytrimethylene ether glycol" ("PO3G"), as
used herein, it is meant oligomers and polymers in which at least
about 50% of the repeating units are trimethylene ether units
--(CH.sub.2--CH.sub.2--CH.sub.2--O--). More preferably from about
75% to 100%, still more preferably from about 90% to 100%, and even
more preferably from about 99% to 100%, of the repeating units are
trimethylene ether units. Such PO3G compounds and the methods for
making such compounds are described in the above-mentioned patent
application, Sunkara et al., U.S. Patent Application Publication
2008/0039582, the disclosure of which is hereby incorporated by
reference. The PO3G compounds are preferably prepared by
polycondensation of monomers comprising 1,3-propanediol, thus
resulting in polymers or copolymers containing
--(CH.sub.2CH.sub.2CH.sub.2O)-- linkages (e.g, trimethylene ether
repeating units). The 1,3-propanediol employed for preparing the
PO3G may be obtained by any of the various well known chemical
routes or by biochemical transformation routes. Preferably, the
1,3-propanediol is obtained biochemically from a renewable source
("biologically-derived" 1,3-propanediol).
[0030] The compounds of this invention based on polytrimethylene
ether glycols, may contain lesser amounts of other polyalkylene
ether repeating units in addition to the trimethylene ether units.
The monomers for use in preparing polytrimethylene ether glycols
can, therefore, contain up to 50% by weight (preferably about 20 wt
or less, more preferably about 10 wt % or less, and still more
preferably about 2 wt % or less), of comonomer polyols in addition
to the 1,3-propanediol reactant. Comonomer polyols that are
suitable for use in the process include aliphatic diols, for
example, ethylene glycol, 1,6-hexanediol, 1,7-heptanediol,
1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol,
3,3,4,4,5,5-hexafluro-1,5-pentanediol,
2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol, and
3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-hexadecafluoro-1,12-dodecanediol;
cycloaliphatic diols, for example, 1,4-cyclohexanediol,
1,4-cyclohexanedimethanol and isosorbide; and polyhydroxy
compounds, for example, glycerol, trimethylolpropane, and
pentaerythritol. A preferred group of comonomer diols is selected
from the group consisting of ethylene glycol,
2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol,
2,2-diethyl-1,3-propanediol,
2-ethyl-2-(hydroxymethyl)-1,3-propanediol, C.sub.6-C.sub.10 diols
(such as 1,6-hexanediol, 1,8-octanediol and 1,10-decanediol) and
isosorbide, and mixtures thereof. A particularly preferred diol
other than 1,3-propanediol is ethylene glycol, and C.sub.6-C.sub.10
diols can be particularly useful as well. In another embodiment of
the present invention further comprises polytrimethylene ether
ester glycols by reacting 1,3-propanediol with about 10 to about
0.1 mole % of aliphatic or aromatic diacid or esters thereof, such
as terephthalic acid, isophthalic acid, bibenzoic acid, naphthalic
acid, bis(p-carboxyphenyl)methane, 1,5-naphthalene dicarboxylic
acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene
dicarboxylic acid, 4,4'-sulfonyl dibenzoic acid,
p-(hydroxyethoxy)benzoic acid, and combinations thereof, and
dimethyl terephthalate, bibenzoate, isophthlate, naphthalate and
phthalate; and combinations thereof. Of these, terephthalic acid,
dimethyl terephthalate and dimethyl isophthalate are preferred.
[0031] The preferred polytrimethylene ether glycol and blends of
polytrimethylene ether glycol compounds preferably have a number
average molecular weight (M.sub.n) in the range of about 200 to
about 5000, and more preferably from about 500 to about 5000. The
compounds may be blended with other oligomeric and/or polymer
polyfunctional isocyanate-reactive compounds such as, for example,
polyols, polyamines, polythiols, polythioamines, polyhydroxythiols
and polyhydroxylamines. When blended, it is preferred to use
difunctional components and, more preferably, one or more diols
including, for example, polyether diols, polyester diols,
polycarbonate diols, polyacrylate diols, polyolefin diols and
silicone diols. The polytrimethylene ether glycol compounds contain
at least about 40% PO3G and preferably about 60% PO3G. That is, the
PO3G may be blended with up to about 60% polyfunctional oligomeric
and/or polymeric polyfunctional isocyanate-reactive compounds.
Preferably, the blended compounds are a blend of polytrimethylene
ether glycol and a polyether glycol selected from the group
consisting of polyethylene glycol, poly(1,3-propylene)glycol,
polytetramethylene glycol, copolymers of tetrahydrofuran and
ethylene oxide or propylene oxide glycol, and mixtures there
of.
[0032] In the present invention, it is important that the
polytrimethylene ether-based polyurethane contains acid or ester or
ionic groups. That is, the polyurethane composition is preferably
prepared from: i) an isocyanate compound, ii) a polytrimethylene
ether glycol compound, and iii) a curing agent selected from the
group consisting of hydroxyl-terminated curing agents,
amine-terminated curing agents, and mixtures thereof. At least one
of the reactive components contains acid or ester or ionic groups.
The acid or ionic groups are chemically incorporated into the
polytrimethylene ether-based polyurethane in an amount to provide
an acid or ester or ionic content (with neutralization as needed)
sufficient to render improved resiliency and good impact durability
to the resulting golf ball without sacrificing a soft feel and
playing control to the ball. Typically, the acid group content will
range from about 0.5 to about 50 wt %, more preferably from about
2.5 to 45 wt %, and still more preferably from about 5 to 30 wt %
based on the weight of the polytrimethylene-ether based
polyurethane. Suitable compounds for incorporating these groups
include (1) monoisocyanates or diisocyanates which contain acid,
ester, or ionic groups, and (2) compounds which contain both
isocyanate reactive groups and acid, ester, or ionic groups.
[0033] Examples of isocyanates that contain acid or ionic groups
are sulfonated toluene diisocyanate and sulfonated
diphenylmethanediisocyanate. With respect to compounds which
contain isocyanate reactive groups and acid, ester, or ionic
groups, the isocyanate reactive groups are typically amino and
hydroxyl groups. The acid or their corresponding ionic groups may
be cationic or anionic, although the anionic groups are preferred.
Preferred examples of anionic groups include carboxylate and
sulfonate groups. Preferred examples of cationic groups include
quaternary ammonium groups and sulfonium groups. The term
"neutralizing agents" is meant to include all types of agents that
are useful for converting acid groups to the more hydrophilic ionic
(salt) groups.
[0034] More particularly, the isocyanate reactant contains acid or
ionic groups). Preferably, these reactants will contain one or two,
more preferably two, isocyanate reactive groups, as well as at
least one acid or ionic group. Examples of ionic dispersing groups
include carboxylate groups (--COOM), phosphate groups (--OPO.sub.3
M.sub.2), phosphonate groups (--PO.sub.3M.sub.2), sulfonate groups
(--SO.sub.3M), quaternary ammonium groups (--NR.sub.3Y, wherein Y
is a monovalent anion such as chlorine or hydroxyl), or any other
effective ionic group. M is a cation such as a mono-valent metal
ion (e.g., Na.sup.+, K+, Li.+, and the like.), H.sup.+,
NR.sub.4.sup..+, and each R can be independently an alkyl, aralkyl,
aryl, or hydrogen. These ionic dispersing groups are typically
located pendant from the polyurethane backbone.
[0035] The acid groups in general correspond to the ionic groups,
except they are in the acid (such as carboxyl --COOH) or base (such
as primary, secondary or tertiary amine --NH.sub.2, --NRH, or
--NR.sub.2) form. The acid groups are such that they are readily
converted to their ionic form during the polymer preparation
process as discussed below.
[0036] Manufacturing Processes
[0037] There are two basic techniques that can be used to make the
functionalized polytrimethylene ether-based polyurethane
compositions of this invention: a) one-shot technique, and b)
prepolymer technique. In the one-shot technique, the isocyanate,
polytrimethylene ether glycol, and hydroxyl and/or amine-terminated
curing agent are reacted in one step. At least one of the reactive
components contains acid, ester, or ionic groups. Meanwhile, the
prepolymer technique involves a first reaction between the
isocyanate and polytrimethylene ether glycol compounds to produce a
polyurethane prepolymer, and a subsequent reaction between the
prepolymer and hydroxyl and/or amine-terminated curing agent. As a
result of the reaction between the isocyanate and polyol compounds,
there will be some unreacted NCO groups in the polyurethane
prepolymer. The prepolymer should have less than 14% unreacted NCO
groups. Preferably, the prepolymer has no greater than 8.5%
unreacted NCO groups, more preferably from 2.5% to 8%, and most
preferably from 5.0% to 8.0% unreacted NCO groups. As the weight
percent of unreacted isocyanate groups increases, the hardness of
the composition also generally increases.
[0038] When the one-shot technique is used to form the polyurethane
ionomers, the polytrimethylene ether glycol or blends of
polytrimethylene ether glycol with other glycols such as polyester
glycol or polycaprolactone glycol is reacted either with a
diisocyanate having an acid or ester or ionic moiety such as
5-sulfo-isophthalic acid and 1,3 propane-diol or with a
dimethylopropionic acid which is neutralized with a sufficient
amount of a suitable cation source and a chain extender based on
diols or diamines. When the two-shot (prepolymer) technique is used
to form the polyurethane ionomers, the prepolymer having a
polytrimethylene ether glycol based diisocyanate is reacted either
with a diisocyanate having an acid or ester or ionic moiety such as
5-sulfo-isophthalic acid and 1,3 propane-diol or with a
dimethylopropionic acid which is neutralized with a sufficient
amount of a suitable cation source and a chain extender based on
diols or diamines. The acid moiety is converted into an ionic
moiety by selectively neutralizing the acid groups using suitable
counter ions or salts. In one embodiment, the neutralization level
is from 10 to 80%, more preferably 20 to 70%, and most preferably
30 to 50%. In another embodiment, the neutralization level is from
80 to 100%, more preferably 90 to 100%, and most preferably 95 to
100%. The acid groups may be neutralized with a suitable cation
source, such as metal cations and salts thereof, organic amine
compounds, ammonium, sodium hydroxide, bases, and combinations
thereof. Preferred cation sources are metal cations and salts
thereof, wherein the metal is preferably lithium, sodium,
potassium, magnesium, calcium, barium, lead, tin, zinc, aluminum,
manganese, nickel, chromium, copper, or a combination thereof. In
addition, melt flow modifiers such as, for example, fatty acids and
salts thereof, particularly stearic, benefic, erucic, oleic,
linoelic, and dimerized derivatives thereof may be used. Organic
acids and salts of organic acids also may be used.
[0039] Either the one-shot or prepolymer method may be employed to
produce the functionalized polytrimethylene ether-based
polyurethane compositions of the invention; however, the prepolymer
technique is preferred because it provides better control of the
chemical reaction. The prepolymer method provides a more
homogeneous mixture resulting in a more consistent polymer
composition. The one-shot method results in a mixture that is
inhomogeneous (more random) and affords the manufacturer less
control over the molecular structure of the resultant
composition.
[0040] In the casting process, the functionalized polytrimethylene
ether-based polyurethane composition can be formed by
chain-extending the polyurethane prepolymer with a single curing
agent or blend of curing agents as described further below. The
compositions of the present invention may be selected from among
both castable thermoplastic and thermoset materials. Thermoplastic
polyurethane compositions are typically formed by reacting the
isocyanate and polyol compound, each having two (or less)
functional groups, at a 1:1 stoichiometric ratio. Thermoset
compositions, on the other hand, are cross-linked polymers and are
typically produced from the reaction of an isocyanate and
hydroxyl-terminated compound, wherein each component has two (or
greater) functional groups, at normally a 1.05:1 stoichiometric
ratio. In general, thermoset polyurethane compositions are easier
to prepare than thermoplastic polyurethanes.
[0041] Chain-Extending of Prepolymer
[0042] The functionalized polytrimethylene ether-based polyurethane
prepolymer can be chain-extended by reacting it with a single
curing agent or blend of curing agents. In general, the prepolymer
can be reacted with hydroxyl-terminated curing agents,
amine-terminated curing agents, or mixtures thereof. The curing
agents extend the chain length of the prepolymer and build-up its
molecular weight. Normally, the prepolymer and curing agent are
mixed so the isocyanate groups and hydroxyl or amine groups are
mixed at a 1.05:1.00 stoichiometric ratio.
[0043] A catalyst may be employed to promote the reaction between
the isocyanate and polyol compounds for producing the prepolymer or
between prepolymer and curing agent during the chain-extending
step. Preferably, the catalyst is added to the reactants before
producing the prepolymer. Suitable catalysts include, but are not
limited to, bismuth catalyst; zinc octoate; stannous octoate; tin
catalysts such as bis-butyltin dilaurate, bis-butyltin diacetate,
stannous octoate; tin (II) chloride, tin (IV) chloride,
bis-butyltin dimethoxide, dimethyl-bis[1-oxonedecyl)oxy]stannane,
di-n-octyltin bis-isooctyl mercaptoacetate; amine catalysts such as
triethylenediamine, triethylamine, and tributylamine; organic acids
such as oleic acid and acetic acid; delayed catalysts; and mixtures
thereof. 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 1 percent, and preferably 0.1 to 0.5
percent, by weight of the composition.
[0044] The hydroxyl chain-extending (curing) agents are preferably
selected from the group consisting of ethylene glycol; diethylene
glycol; polyethylene glycol; propylene glycol; 2-methyl-1,3
-propanediol; 2-methyl-1,4-butanediol; monoethanolamine;
diethanolamine; triethanolamine; monoisopropanolamine;
diisopropanolamine; 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. The acid, ester, or ionic derivatives of the
hydroxyl curing agents also can be used per this invention.
[0045] Suitable amine chain-extending (curing) agents that can be
used in chain-extending the polyurethane prepolymer of this
invention include, but are not limited to, unsaturated diamines
such as 4,4'-diamino-diphenylmethane (i.e.,
4,4'-methylene-dianiline or "MDA"), m-phenylenediamine,
p-phenylenediamine, 1,2- or 1,4-bis(sec-butylamino)benzene,
3,5-diethyl-(2,4- or 2,6-)toluenediamine or "DETDA",
3,5-dimethylthio-(2,4- or 2,6-)toluenediamine,
3,5-diethylthio-(2,4- or 2,6-)toluenediamine,
3,3'-dimethyl-4,4'-diamino-diphenylmethane,
3,3'-diethyl-5,5'-dimethyl4,4'-diamino-diphenylmethane (i.e.,
4,4'-methylene-bis(2-ethyl-6-methyl-benezeneamine)),
3,3'-dichloro-4,4'-diamino-diphenylmethane (i.e.,
4,4'-methylene-bis(2-chloroaniline) or "MOCA"),
3,3',5,5'-tetraethyl-4,4'-diamino-diphenylmethane (i.e.,
4,4'-methylene-bis(2,6-diethylaniline),
2,2'-dichloro-3,3',5,5'-tetraethyl-4,4'-diamino-diphenylmethane
(i.e., 4,4'-methylene-bis(3-chloro-2,6-diethyleneaniline) or
"MCDEA"), 3,3'-diethyl-5,5'-dichloro-4,4'-diamino-diphenylmethane,
or "MDEA"),
3,3'-dichloro-2,2',6,6'-tetraethyl-4,4'-diamino-diphenylmethane,
3,3'-dichloro-4,4'-diamino-diphenylmethane,
4,4'-methylene-bis(2,3-dichloroaniline) (i.e.,
2,2',3,3'-tetrachloro-4,4'-diamino-diphenylmethane or "MDCA"),
4,4'-bis(sec-butylamino)-diphenylmethane,
N,N'-dialkylamino-diphenylmethane,
trimethyleneglycol-di(p-aminobenzoate),
polyethyleneglycol-di(p-aminobenzoate),
polytetramethyleneglycol-di(p-aminobenzoate); saturated diamines
such as ethylene diamine, 1,3-propylene diamine,
2-methyl-pentamethylene diamine, hexamethylene diamine, 2,2,4- and
2,4,4-trimethyl-1,6-hexane diamine, imino-bis(propylamine),
imido-bis(propylamine), methylimino-bis(propylamine) (i.e.,
N-(3-aminopropyl)-N-methyl-1,3-propanediamine),
1,4-bis(3-aminopropoxy)butane (i.e.,
3,3'-[1,4-butanediylbis-(oxy)bis]-1-propanamine),
diethyleneglycol-bis(propylamine) (i.e.,
diethyleneglycol-di(aminopropyl)ether),
4,7,10-trioxatridecane-1,13-diamine,
1-methyl-2,6-diamino-cyclohexane, 1,4-diamino-cyclohexane,
poly(oxyethylene-oxypropylene) diamines, 1,3- or
1,4-bis(methylamino)-cyclohexane, isophorone diamine, 1,2- or
1,4-bis(sec-butylamino)-cyclohexane, N,N'-diisopropyl-isophorone
diamine, 4,4'-diamino-dicyclohexylmethane,
3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane,
3,3'-dichloro-4,4'-diamino-dicyclohexylmethane,
N,N'-dialkylamino-dicyclohexylmethane, polyoxyethylene diamines,
3,3'-diethyl-5,5'-dimethyl-4,4'-diamino-dicyclohexylmethane,
polyoxypropylene diamines,
3,3'-diethyl-5,5'-dichloro-4,4'-diamino-dicyclohexylmethane,
polytetramethylene ether diamines,
3,3',5,5'-tetraethyl-4,4'-diamino-dicyclohexylmethane (i.e.,
4,4'-methylene-bis(2,6-diethylaminocyclohexane)),
3,3'-dichloro-4,4'-diamino-dicyclohexylmethane,
2,2'-dichloro-3,3',5,5'-tetraethyl-4,4'-diamino-dicyclohexylmethane,
(ethylene oxide)-capped polyoxypropylene ether diamines,
2,2',3,3'-tetrachloro-4,4'-diamino-dicyclohexylmethane,
4,4'-bis(sec-butylamino)-dicyclohexylmethane; triamines such as
diethylene triamine, dipropylene triamine, (propylene oxide)-based
triamines (i.e., polyoxypropylene triamines),
N-(2-aminoethyl)-1,3-propylenediamine (i.e., N.sub.3 -amine),
glycerin-based triamines, (all saturated); tetramines such as
N,N'-bis(3-aminopropyl)ethylene diamine (i.e., N.sub.4-amine) (both
saturated), triethylene tetramine; and other polyamines such as
tetraethylene pentamine (also saturated). The amine curing agents
used as chain extenders normally have a cyclic structure and a low
molecular weight (250 or less). The acid, ester, or ionic
derivatives of the amine curing agents also can be used per this
invention.
[0046] When the polyurethane prepolymer is reacted with
hydroxyl-terminated curing agents during the chain-extending step,
as described above, the resulting composition is essentially a pure
polyurethane composition. On the other hand, when the polyurethane
prepolymer is reacted with an amine-terminated curing agent during
the chain-extending step, any excess isocyanate groups in the
prepolymer will react with the amine groups in the curing agent and
create urea linkages.
[0047] This chain-extending step, which occurs when the
polyurethane prepolymer is reacted with hydroxyl-terminated curing
agents, amine-terminated curing agents, or mixtures thereof,
builds-up the molecular weight and extends the chain length of the
prepolymer. When the polyurethane prepolymer is reacted with
hydroxyl-terminated curing agents, a polyurethane composition
having urethane linkages is produced. When the polyurethane
prepolymer is reacted with amine-terminated curing agents, a
polyurethane/urea hybrid composition having urethane and urea
linkages is produced. The polyurethane/urea hybrid composition is
distinct from the pure polyurethane composition. The concentration
of urethane and urea linkages in the hybrid composition may vary.
In general, the hybrid composition may contain a mixture of about
10 to 90 wt. % urethane and about 90% to 10 wt. % urea linkages.
The resulting polyurethane composition or polyurethane/urea hybrid
composition has elastomeric properties based on phase separation of
the soft and hard segments. The soft segments, which are formed
from the polyol reactants, are generally flexible and mobile, while
the hard segments, which are formed from the isocyanate and chain
extenders, are generally stiff and immobile.
[0048] Golf Ball Construction
[0049] Core
[0050] The cores in the golf balls of this invention are typically
made from rubber compositions containing a base rubber,
free-radical initiator agent, cross-linking co-agent, and fillers.
The base rubber may be selected, for example, from polybutadiene
rubber, polyisoprene rubber, natural rubber, ethylene-propylene
rubber, ethylene-propylene diene rubber, styrene-butadiene rubber,
and combinations of two or more thereof A preferred base rubber is
polybutadiene. Another preferred base rubber is polybutadiene
optionally mixed with one or more elastomers such as polyisoprene
rubber, natural rubber, ethylene propylene rubber, ethylene
propylene diene rubber, styrene-butadiene rubber, polystyrene
elastomers, polyethylene elastomers, polyurethane elastomers,
polyurea elastomers, acrylate rubbers, polyoctenamers,
metallocene-catalyzed elastomers, and plastomers. Highly
neutralized olefin-based polymers, as known in the art, also can be
used to form the core layer. Such materials are disclosed, for
example, in U.S. Pat. No. 6,756,436, the disclosure of which is
hereby incorporated by reference. The base rubber typically is
mixed with at least one reactive cross-linking co-agent to enhance
the hardness of the rubber composition. Suitable co-agents include,
but are not limited to, unsaturated carboxylic acids and
unsaturated vinyl compounds. A preferred unsaturated vinyl is
trimethylolpropane trimethacrylate.
[0051] The rubber composition is cured using a conventional curing
process. Suitable curing processes include, for example, peroxide
curing, sulfur curing, high-energy radiation, and combinations
thereof. In one embodiment, the base rubber is peroxide cured.
Organic peroxides suitable as free-radical initiators include, for
example, dicumyl peroxide; n-butyl-4,4-di(t-butylperoxy)valerate;
1,1-di(t-butylperoxy)3,3,5-trimethylcyclohexane;
2,5-dimethyl-2,5-di(t-butylperoxy)hexane; di-t-butyl peroxide;
di-t-amyl peroxide; t-butyl peroxide; t-butyl cumyl peroxide;
2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3;
di(2-t-butyl-peroxyisopropyl)benzene; dilauroyl peroxide; dibenzoyl
peroxide; t-butyl hydroperoxide; and combinations thereof.
Cross-linking agents are used to cross-link at least a portion of
the polymer chains in the composition. Suitable cross-linking
agents include, for example, metal salts of unsaturated carboxylic
acids having from 3 to 8 carbon atoms; unsaturated vinyl compounds
and polyfunctional monomers (e.g., trimethylolpropane
trimethacrylate); phenylene bismaleimide; and combinations thereof
In a particular embodiment, the cross-linking agent is selected
from zinc salts of acrylates, diacrylates, methacrylates, and
dimethacrylates. In another particular embodiment, the
cross-linking agent is zinc diacrylate ("ZDA"). Commercially
available zinc diacrylates include those selected from Rockland
React-Rite and Sartomer.
[0052] The rubber compositions also may contain "soft and fast"
agents such as a halogenated organosulfur, organic disulfide, or
inorganic disulfide compounds. Particularly suitable halogenated
organosulfur compounds include, but are not limited to, halogenated
thiophenols.
[0053] Preferred organic sulfur compounds include, but not limited
to, pentachlorothiophenol ("PCTP") and a salt of PCTP. A preferred
salt of PCTP is ZnPCTP. A suitable PCTP is sold by the Struktol
Company (Stow, Ohio) under the tradename, A95. ZnPCTP is
commercially available from EchinaChem (San Francisco, Calif.).
These compounds also may function as cis-to-trans catalysts to
convert some cis-1,4 bonds in the polybutadiene to trans-1,4 bonds.
Antioxidants also may be added to the rubber compositions to
prevent the breakdown of the elastomers. Other ingredients such as
accelerators (for example, tetra methylthiuram), processing aids,
dyes and pigments, wetting agents, surfactants, plasticizers, as
well as other additives known in the art may be added to the rubber
composition. The core may be formed by mixing and forming the
rubber composition using conventional techniques. These cores can
be used to make finished golf balls by surrounding the core with
outer core layer(s), intermediate layer(s), and/or cover materials
as discussed further below. In another embodiment, the cores can be
formed using a highly neutralized polymer compositions as disclosed
in U.S. Pat. Nos. 6,756,436, 7,402,629, 7,517,289 and 7,030,192.
Furthermore, the cores from the highly neutralized polymer
compositions can be further cross-linked using any crosslinkable
sources including radiation sources such as gamma or electron beam
as well as chemical sources such as peroxides and the like.
[0054] Golf balls made in accordance with this invention can be of
any size, although the USGA requires that golf balls used in
competition have a diameter of at least 1.68 inches and a weight of
no greater than 1.62 ounces. For play outside of USGA competition,
the golf balls can have smaller diameters and be heavier. For
example, the diameter of the golf ball may be in the range of about
1.68 to about 1.80 inches. In one embodiment, as shown in FIG. 2,
the core is a single-piece having an outside diameter of about 1.00
to about 1.65 inches. Preferably, the single-piece core has a
diameter of about 1.50 to about 1.64 inches. The core generally
makes up a substantial portion of the ball, for example, the core
may constitute at least about 90% of the ball. The hardness of the
core may vary depending upon desired properties of the ball. In
general, core hardness is in the range of about 10 to about 75
Shore D and more preferably in the range of about 10 to about 60
Shore D. The compression of the core is generally in the range of
about 30 to about 110 and more preferably in the range of about 50
to about 100. In general, when the ball contains a relatively soft
core, the resulting a driver spin rate of the ball is relatively
low. On the other hand, when the ball contains a relatively hard
core, the resulting spin rate of the ball is relatively high. In a
second embodiment, as shown in FIG. 3, the core is made up of two
pieces. The inner core (22) is made of a rubber composition as
described above, while the outer core layer (24) is made of the
polyurethane composition of this invention. In a preferred version,
the outer core layer has a thickness in the range of about 0.030 to
about 0.070 inches and a Shore D surface hardness in the range of
about 40 to about 70.
[0055] In yet another embodiment, as shown in FIG. 5, the core is
made up of three pieces. In the golf ball (35), the multi-layered
core (36) includes an inner core layer (36a) preferably formed of
polybutadiene or other suitable thermoplastic or thermoset
material; an intermediate core layer (36b) formed of the
functionalized polyurethane composition of this invention; and an
outer core layer (36c) formed of polybutadiene or other suitable
thermoplastic or thermoset material. The multi-layered core (36)
generally has a total diameter of about 1.00 to about 1.65 inches
and preferably a diameter of about 1.45 to about 1.60 inches. The
center (36a) generally has a center hardness (Core-H.sub.1) in the
range of about 10 to about 50 Shore D, preferably 15 to 45 Shore D,
and more preferably 20 to 40 Shore D. The intermediate core layer
(36b) generally has a hardness (Core-H.sub.2) in the range of about
40 to about 75 Shore D, preferably 50 to 70 Shore D, and more
preferably 55 to 65 Shore D. The outer core layer (36c) generally
has a hardness (Core-H.sub.3) in the range of about 20 to 80 Shore
D, preferably 40 to 70 Shore D, and more preferably 40 to 60 Shore
D. The thickness of the outer core layer (36c) is generally in the
range of about 0.030 to about 0.070 inches. In a particular
embodiment, Core-H.sub.1 is equal to Core-H.sub.3. In another
particular embodiment, Core-H.sub.1 is less than Core-H.sub.3, and
the difference between Core-H.sub.1 and Core-H.sub.3 is from 15 to
40, preferably from 15 to 20. In yet another particular embodiment,
Core-H.sub.1 is greater than Core-H.sub.3, and the difference
between Core-H.sub.1 and Core-H.sub.3 is from 15 to 40, preferably
from 15 to 20. Preferably, the intermediate layer (36b) has a
surface hardness (Core-H.sub.2) that is greater than both the
center hardness (Core-H.sub.1) and surface hardness of the outer
core layer (Core-H.sub.3). When the functionalized polyurethane
composition of this invention is used to form the intermediate
layer (36b) and the surface hardness of the core's intermediate
layer (Core-H.sub.1) is greater than Core-H.sub.1 and Core-H.sub.3,
this helps the ball have good resiliency and high initial velocity.
As a result, the ball tends to travel longer distances.
[0056] Intermediate and Cover Layers
[0057] The golf balls of this invention preferably include at least
one intermediate layer. As used herein, the term, "intermediate
layer" means a layer of the ball disposed between the core and
cover. The intermediate layer may be considered an outer core layer
or inner cover layer or any other layer disposed between the inner
core and outer cover of the ball. The intermediate layer also may
be referred to as a casing or mantle layer. The intermediate layer
preferably has water vapor barrier properties to prevent moisture
from penetrating into the rubber core. The ball may include one or
more intermediate layers disposed between the inner core and outer
cover.
[0058] The functionalized polytrimethylene ether-based polyurethane
composition of this invention can be used to make the outer core,
intermediate layer, inner cover, and/or outer cover. In some
instances, a traditional thermoplastic or thermosetting composition
may be used to make one layer and a polytrimethylene ether-based
polyurethane composition may be used to make a different layer of
the golf ball. If a conventional thermoplastic or thermosetting
composition is used in one layer (and the polytrimethylene
ether-based polyurethane composition used in a different layer),
then a wide variety of thermoplastic or thermosetting materials can
be employed. These materials include for example, olefin-based
copolymer ionomer resins (for example, Surlyn.RTM. ionomer resins
and DuPont.RTM. HPF 1000 and HPF 2000, commercially available from
E. I. du Pont de Nemours and Company; Iotek.RTM. ionomers,
commercially available from ExxonMobil Chemical Company;
Amplify.RTM. IO ionomers of ethylene acrylic acid copolymers,
commercially available from The Dow Chemical Company; and
Clarix.RTM. ionomer resins, commercially available from A. Schulman
Inc.); polyurethanes; polyureas; copolymers and hybrids of
polyurethane and polyurea; polyethylene, including, for example,
low density polyethylene, linear low density polyethylene, and high
density polyethylene; polypropylene; rubber-toughened olefin
polymers; acid copolymers, for example, poly(meth)acrylic acid,
which do not become part of an ionomeric copolymer; plastomers;
flexomers; styrene/butadiene/styrene block copolymers;
styrene/ethylene-butylene/styrene block copolymers; dynamically
vulcanized elastomers; copolymers of ethylene and vinyl acetates;
copolymers of ethylene and methyl acrylates; polyvinyl chloride
resins; polyamides, poly(amide-ester) elastomers, and graft
copolymers of ionomer and polyamide including, for example,
Pebax.RTM. thermoplastic polyether block amides, commercially
available from Arkema Inc; cross-linked trans-polyisoprene and
blends thereof; polyester-based thermoplastic elastomers, such as
Hytrel.RTM., commercially available from E. I. du Pont de Nemours
and Company; polyurethane-based thermoplastic elastomers, such as
Elastollan.RTM., commercially available from BASF; synthetic or
natural vulcanized rubber; and combinations thereof.
[0059] The functionalized polytrimethylene ether-based polyurethane
composition constituting the layer(s) of the golf ball may contain
additives, ingredients, and other materials in amounts that do not
detract from the properties of the final composition. These
additive materials include, but are not limited to, activators such
as calcium or magnesium oxide; fatty acids such as stearic acid and
salts thereof; fillers and reinforcing agents such as organic or
inorganic particles, for example, clays, talc, calcium, magnesium
carbonate, silica, aluminum silicates zeolites, powdered metals,
and organic or inorganic fibers, plasticizers such as dialkyl
esters of dicarboxylic acids; surfactants; softeners; tackifiers;
waxes; ultraviolet (UV) light absorbers and stabilizers;
antioxidants; optical brighteners; whitening agents such as
titanium dioxide and zinc oxide; dyes and pigments; processing
aids; release agents; and wetting agents.
[0060] The functionalized polytrimethylene ether-based
polyurethanes of this invention may be blended with non-ionomeric
and olefin-based ionomeric polymers to form the composition that
will be used to make the golf ball layer. Examples of non-ionomeric
polymers include vinyl resins, polyolefins including those produced
using a single-site catalyst or a metallocene catalyst,
polyurethanes, polyureas, polyamides, polyphenylenes,
polycarbonates, polyesters, polyacrylates, engineering
thermoplastics, and the like. The blend may contain about 10 to
about 90% by weight of the polyurethane and about 90 to about 10%
by weight of a non-ionomeric polymer. Olefin-based ionomers, such
as ethylene-based copolymers, normally include an unsaturated
carboxylic acid, such as methacrylic acid, acrylic acid, or maleic
acid. Other possible carboxylic acid groups include, for example,
crotonic, maleic, fumaric, and itaconic acid. Low acid and high
acid olefin-based ionomers, as well as blends of such ionomers, may
be used. The acidic group in the olefin-based ionic copolymer is
partially or totally neutralized with metal ions such as zinc,
sodium, lithium, magnesium, potassium, calcium, manganese, nickel,
chromium, copper, or a combination thereof. For example, ionomeric
resins having carboxylic acid groups that are neutralized from
about 10 percent to about 100 percent may be used. In one
embodiment, the neutralization level is from 10 to 80%, more
preferably 20 to 70%, and most preferably 30 to 50%. In another
embodiment, the neutralization level is from 80 to 100%, more
preferably 90 to 100%, and most preferably 95 to 100%. The cation
source used to neutralize the acid groups of the olefin-based
copolymer ionomer may be the same or different cation source used
to neutralize the acid groups in the polytrimethylenee ether-based
polyurethane compound as discussed above. The blend may contain
about 10 to about 90% by weight of the polytrimethylene ether-based
polyurethane and about 90 to about 10% by weight of a partially,
highly, or fully-neutralized olefin-based ionomeric copolymer.
[0061] The golf balls of the present invention preferably have a
"coefficient of restitution" ("COR") of at least 0.750 and more
preferably at least 0.800 (as measured per the test methods below)
and a compression of from about 70 to about 110, preferably from 90
to 100 (as measured per the test methods below).
[0062] Golf Ball Construction
[0063] The polyurethane compositions of this invention may be used
with any type of ball construction known in the art. Such golf ball
designs include, for example, three-piece and four-piece designs.
The core, intermediate casing, and cover portions making up the
golf ball each can be single or multi-layered. In FIG. 1, one
version of a golf ball that can be made in accordance with this
invention is generally indicated at (10). Various patterns and
geometric shapes of dimples (11) can be used to modify the
aerodynamic properties of the golf ball (10). The dimples (11) can
be arranged on the surface of the ball (10) using any suitable
method known in the art.
[0064] Referring to FIG. 2, a three-piece golf ball (12) that can
be made in accordance with this invention is illustrated. In this
version, the ball (12) includes a solid core (14), an intermediate
casing layer (16) made of the polyurethane composition, and cover
layer (18). The core (14) is made of polybutadiene rubber or other
suitable material as described above and has a diameter in the
range of about 1.30 to about 1.60 inches. The cover layer (18) is
made of a thermoplastic composition or thermoset composition as
described above. For example, the cover layer (18) may be formed
from a compound selected from the group consisting of olefin-based
ionomers; polyesters; polyester-ether elastomers; polyester-ester
elastomers; polyamides; polyamide-ether elastomers, and
polyamide-ester elastomers; polyurethanes, polyureas, and
polyurethane-polyurea hybrids; and mixtures thereof The range of
thickness for the polyurethane intermediate layer (16) may vary,
but it generally has a thickness of 0.010 to 0.030 inches,
preferably 0.015 to 0.025 inches, and more preferably about 0.1015
to 0.020 inches. The intermediate layer (16) preferably has a Shore
D surface hardness of 50 to 75, preferably 55 to 70, and most
preferably 60 to 65. The thickness of the intermediate layer is
preferably in the range of about 0.010 to 0.040 inches.
[0065] In one preferred version of a three-piece golf ball, the
core has a first Shore D surface hardness of H.sub.1 in the range
of about 10 to 60; the intermediate layer surrounding the core has
a second Shore D surface hardness of H.sub.2 in the range of about
50 to 75 and a thickness in the range of about 0.010 to about 0.040
inches; and the cover layer surrounding the intermediate layer has
a third Shore D surface hardness of H.sub.3 in the range of about
30 to 60. The ratio of H.sub.3 to H.sub.1 is in the range of about
0.6 to 6.0 In one version, H.sub.2 is greater than H.sub.3; while,
in a second version, H.sub.3 is greater than H.sub.2.
[0066] In another embodiment of a three-piece golf ball, the core
surface hardness is at least 83 JIS C or 52 Shore D, the casing
surface hardness measured on the ball is at least 90 JIS C or 91
Shore C or 62 Shore D, the ten (10) days aged button hardness for
the casing layer is at least 90 JIS C or 60 Shore D, the ball cover
hardness is at least 81 JIS C or 82 Shore C or 59 Shore D and the
ten (10) days aged button hardness for the cover layer is at least
72 JIS C or 72 Shore C or 47 Shore D.
[0067] In a further embodiment for a three-piece golf ball, the
hardness gradient from the center to the outer core surface
hardness is 5 JIS C or below, the outer core surface hardness is at
least 83 JIS C or 52 Shore D, the casing surface hardness measured
on the ball is at least 90 JIS C or 91 Shore C or 62 Shore D, the
ten (10) days aged button hardness for the casing layer is at least
90 JIS C or 60 Shore D, the ball cover hardness is at least 81 JIS
C or 82 Shore C or 59 Shore D and the ten (10) days aged button
hardness for the cover layer of at least 72 JIS C or 72 Shore C or
47 Shore D.
[0068] In yet another three-piece golf ball, the core surface
hardness is at least 88 JIS C or higher, the casing surface
hardness measured on the ball is at least 85 JIS C or less, the ten
(10) days aged button hardness for the casing layer is at least 85
JIS C or less, the ball cover hardness is at least 81 JIS C or 82
Shore C or 59 Shore D, and the ten (10) days aged button hardness
for the cover layer is at least 72 JIS C or 72 Shore C or 47 Shore
D.
[0069] It should be understood the three-piece golf ball
construction shown in FIG. 2 is for illustrative purposes only and
not meant to be restrictive. Other three-piece constructions can be
made per this invention. For example, the cover layer (18) may be
made of the polyurethane composition of this invention. In such an
example, the cover layer (18) may have a thickness in the range of
about 0.010 to about 0.030 inches and a Shore D surface hardness
(H.sub.3) in the range of about 45 to about 65. In this version,
the intermediate layer has a Shore D surface hardness (H.sub.2) in
the range of about 50 to 75. In one version, H.sub.2 is greater
than H.sub.3; while in second version, H.sub.3 is greater than
H.sub.2.
[0070] In FIG. 3, a four-piece golf ball (20) having a
multi-layered core is illustrated. The multi-layered core includes
an inner core (22) and outer core layer (24). The inner core (22)
may be made of a first rubber material, for example, polybutadiene,
or highly neutralized polymer (HNP) and the outer core layer (24)
may be made of the functionalized polytrimethylene ether-based
polyurethane composition of this invention. The golf ball further
includes an intermediate casing layer (26) and cover layer (28).
Conventional thermoplastic or thermoset resins such as olefin-based
ionomeric copolymers, polyamides, polyesters, polycarbonates,
polyolefins, polyurethanes, and polyureas as described above can be
used to make the casing layer (26) and/or cover layer (28). In such
multi-layered cores, the inner core (22) preferably has a diameter
of about 0.50 to about 1.30 inches, more preferably 1.00 to 1.15
inches, and is relatively soft (that is, it may have a compression
of less than about 30.) Meanwhile, the encapsulating outer core
layer (24) generally has a thickness of about 0.030 to about 0.070
inches, preferably 0.035 to 0.065 inches and is relatively hard
(compression of about 70 or greater.) The outer core layer (24)
preferably has a Shore D surface hardness in the range of about 40
to about 70. That is, the two-piece core, which is made up of the
inner core (22) and outer core layer (24), preferably has a total
diameter of about 1.50 to about 1.64 inches, more preferably 1.510
to 1.620 inches, and a compression of about 80 to about 115, more
preferably 85 to 110.
[0071] In another version, the four-piece golf ball includes an
inner core surface hardness of at least 76 JIS C or 43 Shore D, an
outer core surface hardness measured on the ball at least 89 JIS C
or 60 Shore D, a casing surface hardness measured on the ball at
least 93 JIS C or 92 Shore C or 61 Shore D, a ten (10) days aged
button hardness for the casing layer of at least 90 JIS C or 60
Shore D, a ball cover hardness of at least 81 JIS C or 82 Shore C
or 59 Shore D and a ten (10) days aged button hardness for the
cover layer of at least 72 JIS C or 72 Shore C or 47 Shore D.
[0072] In still another version, the four-piece golf ball includes
an inner core surface hardness of at least 76 JIS C or 43 Shore D,
an outer core surface hardness measured on the ball of at least 88
JIS C or greater, a casing surface hardness measured on the ball of
at least 85 JIS C or less, a ball cover hardness of at least 81 JIS
C or 82 Shore C or 59 Shore D and a ten (10) days aged button
hardness for the cover layer of at least 72 JIS C or 72 Shore C or
47 Shore D.
[0073] In FIG. 3, the illustrated four-piece golf ball is not meant
to be limiting. Other four-piece constructions can be made per this
invention. For example, the intermediate casing layer (26) and/or
cover layer (28) may be made of the polyurethane composition of
this invention.
[0074] Turning to FIG. 4, a four-piece golf ball (30) having a
multi-layered cover is shown. The ball (30) includes a solid,
one-piece rubber core (33), an intermediate layer (34), and
multi-layered cover constituting an inner cover layer (31) and
outer cover layer (32). In this version, the inner cover layer (31)
is made of the polyurethane composition of this invention and the
outer cover layer (32) is made of a conventional thermoplastic or
thermosetting resin. The inner cover layer (31) preferably has a
thickness of about 0.020 to about 0.050 inches and Shore D material
hardness of about 50 to about 70. The outer cover layer (32), which
surrounds the inner cover layer (31), may be made of a
thermoplastic or thermoset composition. For example, the outer
cover (32) may be made of polyurethane, polyurea, ionomer resin or
any of the other cover materials described above. The outer cover
layer (32) preferably has a thickness in the range of about 0.020
to about 0.035 inches and a Shore D material hardness in the range
of about 45 to about 65. The four-piece golf ball construction
shown in FIG. 4 is one example and other four-piece constructions
can be made in accordance with this invention. For example, in
another version, the outer cover layer (32) may be made of the
polyurethane composition of this invention.
[0075] Lastly, in FIG. 5, the golf ball (35) includes a
multi-layered core (36) having layers of different hardness as
described above. Particularly, the core includes an inner core
layer (36a) preferably formed of polybutadiene or other suitable
thermoplastic or thermoset material; an intermediate core layer
(36b) formed of the polyurethane composition of this invention; and
an outer core layer (36c) formed of polybutadiene or other suitable
thermoplastic or thermoset material. The outer cover (40) may be
made of the polyurethane composition of this invention. Other
versions of a golf ball having a multi-layered core (36) may be
made in accordance with this invention. For example, a golf ball
having a multi-layered core; an inner cover layer made of an
ionomer resin or other traditional thermoplastic or thermoset
material; and a polyurethane outer cover can be constructed.
[0076] As noted above, the golf ball constructions shown in FIGS.
1-5 are for illustrative purposes only and are not meant to be
restrictive. A wide variety of golf ball constructions may be made
in accordance with the present invention depending upon the desired
properties of the ball so long as at least one layer contains the
polyurethane composition of this invention. As discussed above,
such constructions include, but are not limited to, three-piece,
and four-piece designs and the cores, intermediate layers, and/or
covers may be single or multi-layered. Numerous other golf ball
constructions having layers made of the polyurethane composition of
this invention are contemplated. For example, in another
embodiment, a three-piece cover golf ball can be made. The inner
core has a surface hardness of at least 83 Shore C or 45 Shore D,
the innermost cover layer has a surface hardness measured on the
ball of at least 90 Shore C or 60 Shore D, the intermediate layer
has a surface hardness measured on the ball of at least 93 Shore C
or 62 Shore D. The ten (10) day aged button hardness for the casing
layer is at least 65 Shore D, the ball cover hardness is at least
80 Shore C or 59 Shore D, and the ten (10) day aged button hardness
for the cover layer is at least 72 JIS C or 72 Shore C or 47 Shore
D.
[0077] In another example, a golf ball having a dual core and
single cover layer can be made. The core has a surface hardness of
at least 74 JIS C or 40 Shore D, an outer core surface surface
hardness measured on the ball of at least 85 JIS C or 55 Shore D, a
ball cover hardness of at least 55 Shore D and a ten (10) day aged
button hardness for the cover layer of at least 56 Shore D.
[0078] In yet another example, a two-piece golf ball having a
single core and a single cover can be made. The core has a surface
hardness of at least 78 JIS C or 44 Shore D, a ball cover hardness
of at least 63 Shore D, and a ten (10) day aged button hardness for
the cover layer of at least 64 Shore D. The present invention also
includes a two-piece golf ball having a core and a cover wherein
the cover is formed using a functionalized polytrimethylene ether
based polyurethanes with acid, ester, or ionic moieties and the
core is coated with a moisture barrier composition to prevent
moisture from penetrating into the core. Preferably, the moisture
barrier composition has a moisture vapor transmission rate (MVTR)
of 12.5 g-mil/100 in.sup.2/day or less as disclosed in the U.S.
Pat. Nos. 7,357,733, 6,932,720, and 6,632,147, the disclosures of
which are hereby incorporated by reference.
[0079] The golf balls of this invention may be constructed using
any suitable technique known in the art. These methods generally
include 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.
[0080] The polyurethane compositions of this invention should
provide the golf ball with advantageous properties and features.
Compositions containing the polyurethane compositions, which have
been developed in accordance with this invention, can be used in
various ball constructions to provide desirable playing performance
properties. For example, the compositions may be used to make the
outer core, intermediate layer, and/or inner cover. The resulting
golf ball has sufficient hardness and good impact durability. The
ball has improved resiliency so that it shows good flight distance
when hit off a tee. At the same time, the ball has a soft "feel" so
that its flight path can be controlled on approach shots near the
green.
[0081] It should be understood that concentrations, amounts, and
other numerical data presented herein in a range format are used
merely for convenience and brevity and should be interpreted
flexibly to include not only the numerical values explicitly
recited as the limits of the range, but also to include all the
individual numerical values or sub-ranges encompassed within that
range as if each numerical value and sub-range is explicitly
recited. For example, a numerical range of about 1 to about 4.5
should be interpreted to include not only the explicitly recited
limits of 1 to about 4.5, but also to include individual numerals
such as 2, 3, 4, and sub-ranges such as 1 to 3, 2 to 4, and the
like. The same principle applies to ranges reciting only one
numerical value, such as "less than about 4.5," which should be
interpreted to include all of the above-recited values and ranges.
Further, such an interpretation should apply regardless of the
breadth of the range or the characteristic being described.
[0082] The invention is further illustrated by the following
examples and test methods, although these examples and test methods
should not be construed as limiting the scope of the invention.
[0083] Test Methods
[0084] Compression The compression value of a golf ball or a golf
ball subassembly (for example, golf ball core) is an important
property affecting the ball's playing performance. For example, the
compression of the core can affect the ball's spin rate off the
driver as well as the "feel" of the ball as the club face makes
impact with the ball. In general, balls with relatively low
compression values have a softer feel. As disclosed in Jeff
Dalton's Compression by Any Other Name, Science and Golf IV,
Proceedings of the World Scientific Congress of Golf (Eric Thain
ed., Routledge, 2002) ("J. Dalton") several different methods can
be used to measure compression including Atti compression, Riehle
compression, load/deflection measurements at a variety of fixed
loads and offsets, and effective modulus. For purposes of the
present invention, "compression" refers to Atti compression and is
measured according to a known procedure, using an Atti compression
device, wherein a piston is used to compress a ball against a
spring.
[0085] The travel of the piston is fixed and the deflection of the
spring is measured. The measurement of the deflection of the spring
does not begin with its contact with the ball; rather, there is an
offset of approximately the first 1.25 mm (0.05 inches) of the
spring's deflection. Cores having a very low stiffness will not
cause the spring to deflect by more than 1.25 mm and therefore have
a zero compression measurement. The Atti compression tester is
designed to measure objects having a diameter of 1.680 inches;
thus, smaller objects, such as golf ball cores, must be shimmed to
a total height of 1.680 inches to obtain an accurate reading.
Conversion from Atti compression to Riehle (cores), Riehle (balls),
100 kg deflection, 130-10 kg deflection or effective modulus can be
carried out according to the formulas given in J. Dalton.
[0086] Coefficient of Restitution (COR) The "coefficient of
restitution" or "COR" of a golf ball means the ratio of a ball's
rebound velocity to its initial incoming velocity when the ball is
fired out of an air cannon into a rigid vertical plate. The COR for
a golf ball is written as a decimal value between zero and one. A
golf ball may have different COR values at different initial
velocities. The United States Golf Association (USGA) sets limits
on the initial velocity of the ball so one objective of golf ball
manufacturers is to maximize the COR under these conditions. Balls
with a higher rebound velocity have a higher COR value. Such golf
balls rebound faster, retain more total energy when struck with a
club, and have longer flight distance. In general, the COR of the
ball will increase as the hardness of the ball is increased.
[0087] In the present invention, COR is determined according to a
known procedure, wherein a golf ball or golf ball subassembly (for
example, a golf ball core) is fired from an air cannon at two given
velocities and a velocity of 125 ft/s is used for the calculations.
Ballistic light screens are located between the air cannon and
steel plate at a fixed distance to measure ball velocity. As the
ball travels toward the steel plate, it activates each light screen
and the ball's time period at each light screen is measured. This
provides an incoming transit time period which is inversely
proportional to the ball's incoming velocity. The ball makes impact
with the steel plate and rebounds so it passes again through the
light screens. As the rebounding ball activates each light screen,
the ball's time period at each screen is measured. This provides an
outgoing transit time period which is inversely proportional to the
ball's outgoing velocity. The COR is then calculates as the ratio
of the ball's outgoing transit time period to the ball's incoming
transit time period
(COR=V.sub.out/V.sub.in=T.sub.in/T.sub.out).
[0088] Hardness The surface hardness of a golf ball layer (or other
spherical surface) is obtained from the average of a number of
measurements taken from opposing hemispheres, taking care to avoid
making measurements on the parting line of the core or on surface
defects such as holes or protrusions. Shore D Hardness measurements
are made pursuant to ASTM D-2240 "Indentation Hardness of Rubber
and Plastic by Means of a Durometer." Because of the curved surface
of the golf ball layer, care must be taken to ensure that the golf
ball or golf ball subassembly is centered under the durometer
indentor before a surface hardness reading is obtained. A
calibrated digital durometer, capable of reading to 0.1 hardness
units, is used for all hardness measurements and is set to take
hardness readings at 1 second after the maximum reading is
obtained. The digital durometer must be attached to and its foot
made parallel to the base of an automatic stand. The weight on the
durometer and attack rate conforms to ASTM D-2240. It should be
understood that there is a fundamental difference between "material
hardness" and "hardness as measured directly on a golf ball." For
purposes of the present invention, material hardness is measured
according to ASTM D2240 and generally involves measuring the
hardness of a flat "slab" or "button" formed of the material.
Surface hardness as measured directly on a golf ball (or other
spherical surface) typically results in a different hardness value.
The difference in "surface hardness" and "material hardness" values
is due to several factors including, but not limited to, ball
construction (that is, core type, number of cores and/or cover
layers, and the like); ball (or sphere) diameter; and the material
composition of adjacent layers. It also should be understood that
the two measurement techniques are not linearly related and,
therefore, one hardness value cannot easily be correlated to the
other. JIS-C hardness was measured according to the test methods
JIS K 6301-1975. Shore C hardness was measured according to the
test methods D2240-05.
EXAMPLES
[0089] The following prophetic examples describe functionalized
polytrimethylene ether-based polyurethane ionomer compositions that
can be prepared and used to make golf balls of this invention. As
discussed above, the compositions can be used to make any layer of
the golf ball layer (for example, outer cover, intermediate, inner
cover, or outer core layer) The compositions provide the golf ball
with high impact durability and scuff-resistance as well as high
resiliency and other desirable properties.
Example 1
[0090] This example illustrates preparation of a functionalized
polytrimethylene ether-based polyurethane or polyurethane/polyurea
hybrid ionomer from a polytrimethylene ether glycol, m-phenylene
diisocyanate, and ether-ester diol based on 5-sulfo-isophthalic
acid with 1,3-propane diol, which is chain-extended with a diamine
such as 1,6-hexadiamine and further neutralized in the presence of
a sufficient amount of suitable cation source such as sodium
hydroxide to achieve a desired neutralization of about 50 to 90%.
In this example, a one-shot manufacturing technique was used to
combine the ingredients. However, it also is recognized that the
above functionalized polymer can be prepared by a pre-polymer
method by reacting a pre-polymer based on an isocyanate, a
polytrimethylene ether glycol and an ether-ester diol based on
5-sulfo-isophthalic acid with 1,3-propane diol in the presence of a
suitable chain extending agent and a cation source.
Example 2
[0091] In this example, the one-shot method is used to prepare a
functionalized polytrimethylene ether-based polyurethane ionomer
from a polytrimethylene ether glycol, m-phenylene diisocyanate,
ether-ester diol based on 5-sulfo-isophthalic acid and 1,3-propane
diol, and N,N'-diethyl amino-diphenylmethane chain terminator and a
sufficient amount of sodium hydroxide to achieve a neutralization
of the acid content to about 60%.
Example 3
[0092] In this example, the one-shot method is used to prepare a
functionalized polytrimethylene ether-based polyurethane ionomer
from polytrimethylene ether glycol, m-phenylene diisocyanate,
ether-ester diol based on 5-sulfo-isophthalic acid and 1,3-propane
diol and N,N'-diethyl amino-diphenylmethane chain terminator and a
sufficient amount of sodium hydroxide to achieve a neutralization
of the acid content to about 100%.
[0093] The above-described compositions also can be prepared by a
two-shot method, that is, by reacting previously made prepolymers
with polyols and chain extenders.
[0094] It is understood that the golf balls described and
illustrated herein represent only presently preferred embodiments
of the invention. It is appreciated by those skilled in the art
that various changes and additions can be made to such golf balls
without departing from the spirit and scope of this invention. It
is intended that all such embodiments be covered by the appended
claims.
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