U.S. patent application number 12/363938 was filed with the patent office on 2010-02-04 for golf ball.
Invention is credited to Viktor Keller, Thomas J. Kennedy, III, Gary Matroni.
Application Number | 20100029413 12/363938 |
Document ID | / |
Family ID | 39170428 |
Filed Date | 2010-02-04 |
United States Patent
Application |
20100029413 |
Kind Code |
A1 |
Matroni; Gary ; et
al. |
February 4, 2010 |
Golf Ball
Abstract
A low modulus durable coating layer for a polyurethane covered
golf ball is disclosed herein. The coating includes a high
equivalent weight polyester polyol wherein the high equivalent
weight polyester polyol has an equivalent weight of at least
1000.
Inventors: |
Matroni; Gary; (Agawam,
MA) ; Kennedy, III; Thomas J.; (Wilbraham, MA)
; Keller; Viktor; (Beverly Hills, FL) |
Correspondence
Address: |
CALLAWAY GOLF C0MPANY
2180 RUTHERFORD ROAD
CARLSBAD
CA
92008-7328
US
|
Family ID: |
39170428 |
Appl. No.: |
12/363938 |
Filed: |
February 2, 2009 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11853944 |
Sep 12, 2007 |
7485052 |
|
|
12363938 |
|
|
|
|
60825556 |
Sep 13, 2006 |
|
|
|
Current U.S.
Class: |
473/378 ;
473/607 |
Current CPC
Class: |
A63B 37/0022
20130101 |
Class at
Publication: |
473/378 ;
473/607 |
International
Class: |
A63B 37/12 20060101
A63B037/12 |
Claims
1. A coating for a golf ball comprising: a high equivalent weight
polyester polyol and an isocyanate, wherein the high equivalent
weight polyester polyol has an equivalent weight of at least
1000.
2. A coating for a sport ball comprising: a high equivalent weight
polyester polyol and an isocyanate, wherein the high equivalent
weight polyester polyol has an equivalent weight of at least
1000.
3. A coating for a sport ball comprising: a first chemical
component comprising a first polyol, a second polyol and a third
polyol, n-butyl acetate, methyl amyl ketone, methyl isobutyl
ketone, titanium dioxide, UV absorber and acrylate additives,
wherein the first polyol is a high equivalent weight polyester
polyol, the second polyol is a saturated polyester polyol, and the
third polyol is a saturated polyester polyol, and a second chemical
component comprising methyl isobutyl ketone and an isocyanate
compound.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The Present Application is a divisional application of U.S.
patent application Ser. No. 11/853,944, filed on Sep. 12, 2007,
which claims priority to U.S. Provisional Patent Application No.
60/825,556, filed on Sep. 13, 2006.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a coating for a golf ball.
More specifically, the present invention relates to a coating for a
golf ball with a polyurethane cover.
[0005] 2. Description of the Related Art
[0006] Current coatings do not have sufficient durability and
processing capability for premium polyurethane covered golf balls.
Especially reaction injection molded polyurethane covered golf
balls.
[0007] Yoneyama, U.S. Pat. No. 6,210,695 for a Golf Ball Having
Coated Surface Layer Of Polyurethane discloses a clear top coat
used to form the outermost layer of a golf ball which comprises (A)
a polyol component containing a polyurethane polyol which has been
produced from a diisocyanate compound and a hydroxyl
group-containing compound and which has urethane bonds in the main
chain thereof and hydroxyl groups at the chain ends and has a
hydroxyl value of 20 to 100 mgKOH/g when the non-volatile content
is 100% by weight, a concentration of urethane group of 1 to 5
millimoles/g and a weight average molecular weight of 10,000 to
50,000, and (B) a yellowing resistant polyisocyanate as a hardener,
wherein the NCO/OH equivalent ratio of isocyanate group in said
component (B) to hydroxyl group in said component (A) is from
0.7/1.0 to 2.0/1.0.
[0008] Ohira, et al., U.S. Pat. No. 6,509,410 for an Aqueous
Coating Composition For Golf Ball And Golf Ball Using The Same
discloses an aqueous coating composition for golf ball, comprising:
a water-soluble urethane polyol having a hydroxyl value of 100 to
300 mgKOH/g, obtained by reacting a polyol component and a
polyisocyanate component, and a hydrophilic group-containing
polyisocyanate. (2) An aqueous coating composition for golf ball,
comprising: a water-soluble urethane polyol having a hydroxyl value
of 100 to 300 mgKOH/g, obtained by reacting a polyol component and
a polyisocyanate component, a water-dispersible urethane resin, and
a hydrophilic group-containing polyisocyanate.
[0009] Fushihara, U.S. Pat. No. 6,713,588 for a Golf Ball,
discloses a polyurethane clear coating film is made by curing a
polyol with an isocyanate curing agent, wherein the polyol is a
mixture of a polyester polyol and a polyether polyol.
[0010] U.S. Pat. No. 5,885,173 discloses an indicia for a golf ball
and is hereby incorporated by reference in its entirety. U.S. Pat.
No. 6,001,177 discloses painting system for painting a golf ball
and is hereby incorporated by reference in its entirety. U.S. Pat.
No. 5,300,325 discloses a method for finishing a golf ball and is
hereby incorporated by reference in its entirety. U.S. Pat. No.
5,409,233 discloses a coating composition for a golf ball and is
hereby incorporated by reference in its entirety. U.S. Pat. No.
5,494,291 discloses a coating composition for a golf ball and is
hereby incorporated by reference in its entirety. U.S. Pat. No.
6,146,288 discloses a coating composition for a golf ball and is
hereby incorporated by reference in its entirety. U.S. Pat. No.
6,245,386 discloses a method for finishing a golf ball and is
hereby incorporated by reference in its entirety.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention is a low modulus coating that utilizes
a high equivalent weight polyester polyol as a modifier for a
polyester polyol/polyisocyanate solvent borne coatings system. The
system may contain a whitening agent such as titanium dioxide. Due
to the lower reactivity of the linear, high equivalent weight
polyol, more catalyst (dibutyl tin dilaurate) is required to cure
the coating in a reasonable processing timeframe.
[0012] The linear, high equivalent weight (low hydroxyl %) polyol
is used in conjunction with lower equivalent weight (high hydroxyl
%) polyester polyols. This polyol system is then crosslinked with a
polyisocyanate material (polymeric isocyanate, prepolymer
isocyanate) to form a tough, durable coating that has excellent
adhesion to the golf ball cover.
[0013] Having briefly described the present invention, the above
and further objects, features and advantages thereof will be
recognized by those skilled in the pertinent art from the following
detailed description of the invention when taken in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0014] FIG. 1 shows a cross-sectional view of a multiple-layer golf
ball.
[0015] FIG. 2 shows a cross-sectional view of a two-piece golf
ball.
DETAILED DESCRIPTION OF THE INVENTION
[0016] A coating for a golf ball is disclosed herein. The coating
is preferably used on a polyurethane covered golf ball, and more
preferably a reaction injection molded polyurethane covered golf
ball. The coating preferably includes a high equivalent weight
polyester polyol which makes it more abrasion resistant. A
preferred high equivalent weight polyester polyol is DESMOPHEN
1652A solvent-free linear saturated polyester polyol which is
available from BAYER MATERIAL. The coating may also include other
polyester polyols such as DESMOPHEN 670A 80 a saturated polyester
polyol and DESMOPHEN 631A 75, which is another saturated polyester
polyol, both available from BAYER MATERIAL. The preferred high
equivalent weight polyester polyol, DESMOPHEN 1652A solvent-free
linear saturated polyester polyol, has an equivalent weight of
1002. Other additives used in the coating include BYK-354
polyacrylate additive for inks available from BYK-Chemie, and
SANDOVAR additive, TINUVIN 292 UV absorber, FINNTITIAN RDI titanium
dioxide, T-12 additive, methyl isobutyl ketone ("MIEK"), methyl
amyl ketone ("MAK") and n-butyl acetate.
[0017] A preferred isocyanate compound is DESMODUR N-3200 aliphatic
polyisocyanate available from BAYER MATERIAL, which is a
hexamethylene diisocyanate; hexamethylene diisocyanate biuret,
having a nitrogen-carbon-oxygen group content of approximately
23%.
[0018] One formulation has 10 parts DESMOPHEN 631A 75, 10 parts
DESMOPHEN670A 80, 20 parts DESMOPHEN 1652A, 0.06 parts DABCOT-12,
0.7 parts white pigment and 196.8 parts DESMODUR 3200.
TABLE-US-00001 TABLE ONE Part A Weight (gms) Grind Desmophen
670A-80 111.03 n-Butyl Acetate 20.76 Methyl Amyl Ketone 30.75
Finntitan RDI 236.84 399.38 Letdown Desmophen 670A-80 46.10
Desmophen 631A-75 23.94 Desmophen 1652A 35.92 Byk 354 1.32 T-12
0.34 Sandovur 3206 1.32 Tinuvin 292 1.32 n-Butyl Acetate 71.76
Methyl Isobutyl Ketone 66.17 Methyl Amyl Ketone 154.29 Subtotal
402.48 Total 801.86
TABLE-US-00002 TABLE TWO Part B MIBK 118.86 Desmodur N-3200 83.58
202.44 Mix Ratio (by weight) 0r 3 to 1 by Volume Part A - 160 grams
WPG - Part A 9.97 Part B - 40 grams WPG - Part B 7.55
TABLE-US-00003 TABLE THREE Material Part A Weight Volume TNV
Desmophen 670A80 298.55 32.45 238.84 Desmophen 1652A 68.24 6.96
68.24 Desmophen 631A75 45.49 4.94 34.12 Catafor CA-100 2.61 0.33
2.61 Byk 370 20.44 2.67 5.11 FC-430 1.04 0.11 1.04 Dabco T-12 1.14
0.12 1.14 Sandover 3206 2.48 0.29 2.48 Tinuvin 292 2.48 0.30 2.48
Uvitex OB 0.35 0.03 0.35 Butyl Acetate 99.64 13.58 0.00 MAK 168.51
24.78 0.00 Sub Total 710.97 86.56 356.41
TABLE-US-00004 TABLE FOUR Part B Desmodur N-3200 158.80 17.08
158.80 MIBK 174.63 26.17 0.00 Sub Total 333.43 43.25 158.80 Total
1044.40 129.81 515.21 PROPERTIES: Wt/gal Part A 8.21 lbs. TNV Part
A 50.13% Part B 7.71 lbs. Part B 47.63% A/B 8.04 lbs. A/B
49.33%
[0019] Referring now to the drawings, FIG. 1 shows a multi-layer
golf ball 10 with a solid core 12, a mantle or inner cover layer
14, and an outer cover layer 16. The outer cover layer 16 is
preferably composed of a polyurethane material. Alternatively, the
inner cover layer 34 and/or the outer cover layer 36 can comprise
ionomer or another conventional golf ball cover material. Such
conventional golf ball cover materials typically contain titanium
dioxide utilized to make the cover white in appearance. FIG. 2
shows a two-piece golf ball having a cover comprising a
polyurethane. The golf ball 10 includes a polybutadiene core 12 and
a polyurethane cover 16 preferably formed by RIM.
[0020] RIM processes and materials that are useful in forming the
golf ball of the present invention are disclosed in the following
U.S. Patents, all of which are hereby incorporated by reference in
their entireties: U.S. Pat. No. 6,290,614 for a Golf Ball Which
Includes Fast-Chemical-Reaction-Produced Component And Method Of
Making Same; U.S. Pat. No. 6,533,566 for an Apparatus For Making A
Golf Ball; U.S. Pat. No. 6,716,954 for a Golf Ball Formed From A
Polyisocyanate Copolymer And Method Of Making Same; U.S. Pat. No.
6,755,634 for an Apparatus For Forming A Golf Ball With Deep
Dimples; U.S. Pat. No. 6,776,731 for an Apparatus And Process For
Forming A Golf Ball With Deep Dimples; and, U.S. Pat. No. 6,790,149
for a Golf Ball.
[0021] The balls shown in FIG. 1 through FIG. 3 may be of a
standard, enlarged or reduced size. Further, the core, intermediate
and cover components may comprise any number of layers or sub-parts
desired.
[0022] Golf balls comprising a golf ball component according to the
present disclosure are also contemplated. If the component is a
cover layer, then a wide array of materials may be used for the
cores and mantle layer of the golf ball. For instance, the core and
mantle or interior layer materials disclosed in U.S. Pat. Nos.
5,833,553, 5,830,087, 5,820,489 and 5,820,488, all of which are
hereby incorporated by reference in their entirety, may be
employed. If the component is a core or inner layer, then a variety
of conventional materials may be used for one or more cover layers.
For instance, the cover layer may employ materials such as
disclosed in U.S. Pat. Nos. 6,309,314, 6,277,921, 6,220,972,
6,150,470, 6,126,559, 6,117,025, 5,902,855, 5,895,105, 5,688,869,
5,591,803, and 5,542,677, all of which are hereby incorporated by
reference in their entireties.
[0023] If the component is a golf ball cover, the golf ball may be
a two-piece or multi-layer ball having a wound core, a solid,
non-wound core, a liquid core, or a gel core.
[0024] One or more intermediate or cover layers can be included
having different characteristics. For golf balls for which feel and
playability is important, it is particularly advantageous to have
an outer cover Shore D hardness of 60 or less, including 50 or
less. For golf balls for which lower spin rates and increased
distance is important, it is particularly advantageous to have an
outer cover Shore D hardness of 60 or more, including 70 or more.
These measurements are made in general accordance with ASTM 2240,
except they are made on the ball itself and not on a plaque. The
outer layer is from about 0.005 to about 0.20 inches in thickness,
including about 0.001 to about 0.100 inches in thickness. Thickness
is defined as the average thickness of the non-dimpled cover of the
outer cover. The cover exhibits good durability characteristics
(i.e., groove shear resistance of 3.5 or less, on a scale of 1 to 6
(lower numbers are better) corresponding to no loss or significant
fraying of the cover material, and cut resistance of 3 or less on a
scale of 1 to 5 (lower numbers are better) corresponding to a
slight dent in the cover not discernible by touch). The groove
shear resistance is measured on golf balls struck by a 56 degree
wedge clubhead at about 103 feet per second. The cut resistance is
measured on golf balls subjected to an off-center blow by a blade
with an approximate 5/64'' radius attached to a sled weighing
approximately 6 lbs dropped from a height of about 42 inches.
[0025] The core of the golf ball can be formed of a solid, or an
encapsulated sphere filled with a gas, a liquid or a gel, or any
other substance that will result in a core or an inner ball (core
and a at least one inner cover layer, if the ball is a multi-layer
ball), having the desired COR, compression and hardness and other
physical properties.
[0026] The cores of the golf ball typically have a coefficient of
restitution of about 0.750 or more, more preferably 0.770 or more,
and a PGA compression of about 125 or less, and more preferably 100
or less. Furthermore, in some applications it may be desirable to
provide a core with a coefficient of restitution of about 0.780 to
about 0.790 or more. The core used in the golf ball is preferably a
solid, but any core type known in the art may be used, such as
wound, liquid, hollow, metal, and the like. The term "solid cores"
as used herein refers not only to one piece cores but also to those
cores having a separate solid layer beneath the covers and over the
central core. The cores generally have a weight of about 25 to
about 40 grams and preferably about 30 to about 40 grams. Larger
and heavier cores, or lighter and smaller cores, may also be used
when there is no desire to meet U.S.G.A. or R. & A.
standards.
[0027] When the golf ball has a solid core, this core can be
compression molded from a slug of uncured or lightly cured
elastomer composition comprising a high cis content polybutadiene
and a metal salt of an .alpha., .beta., ethylenically unsaturated
carboxylic acid such as zinc mono- or diacrylate or methacrylate.
To achieve higher coefficients of restitution and/or to increase
hardness in the core, the manufacturer may include a small amount
of a metal oxide such as zinc oxide. In addition, larger amounts of
metal oxide than are needed to achieve the desired coefficient may
be included in order to increase the core weight so that the
finished ball more closely approaches the U.S.G.A. upper weight
limit of 1.620 ounces.
[0028] Non-limiting examples of other materials that may be used in
the core composition include, but are not limited to, compatible
rubbers or ionomers, and low molecular weight fatty acids such as
stearic acid. Free radical initiator catalysts such as peroxides
may be admixed with the core composition so that on the application
of heat and pressure, a curing or cross-linking reaction takes
place. The core may also be formed from any other process for
molding golf ball cores known in the art.
[0029] A thread wound core may comprise a liquid, solid, gel or
multi-piece center. The thread wound core is typically obtained by
winding a thread of natural or synthetic rubber, or thermoplastic
or thermosetting elastomer such as polyurethane, polyester,
polyamide, etc., on a solid, liquid, gel or gas filled center to
form a thread rubber layer that is then covered with one or more
mantle or cover layers. Additionally, prior to applying the cover
layer(s), the thread wound core may be further treated or coated
with an adhesive layer, protective layer, or any substance that may
improve the integrity of the wound core during application of the
cover layers and ultimately in usage as a golf ball.
[0030] The core, preferably a solid core, is about 1.5 to about 1.6
inches in diameter, although it may be possible to use cores in the
range of about 1.0 to about 2.0 inches. If the ball has a single
cover layer, the core size may be up to about 1.660 inches. The
core 12 of the present invention is preferably a single solid core
such as disclosed in U.S. Pat. No. 6,612,940, assigned to Callaway
Golf Company and which pertinent parts are hereby incorporated by
reference, or such as disclosed in U.S. Pat. No. 6,465,546, also
assigned to Callaway Golf Company and which pertinent parts are
hereby incorporated by reference. However, alternative embodiments
have a non-solid or multiple cores such as disclosed in U.S. Pat.
No. 6,663,509, which pertinent parts are hereby incorporated by
reference.
[0031] The present disclosure includes one or more auxiliary layers
disposed on the core, and a preferably immediately adjacent to the
outer core surface. For example, for some applications, it may be
preferred to deposit a barrier coating that limits transmission of
moisture to the core. Such barrier coatings or layers are
relatively thin. Generally, such coatings are at least 0.0001 inch,
and preferably, at least 0.003 inch in thickess. Furthermore an
adhesion promoting layer may be used between the cover layers
and/or the core, or the cover and core having a barrier coating
disposed thereon. Such adhesion promoting layers are known in the
art and may be used in combination with the features described
herein. See for example U.S. Pat. No. 5,820,488, which is hereby
incorporated by reference.
[0032] The inner cover layer that is molded over the core is
preferably about 0.0005 inch to about 0.15 inch in thickness. The
inner ball that includes the core and inner cover layer(s), or core
for a two piece ball, preferably has a diameter in the range of
1.25 to 1.67 inches. The outer cover layer is about 0.0005 inch to
about 0.20 inch thick. Together, the core, the inner cover layer(s)
and the outer cover layer (or core and single cover layer) combine
to form a ball having a diameter of 1.680 inches or more, the
minimum diameter permitted by the rules of the U.S.G.A. and
weighing no more than 1.62 ounces. If desired, golf balls of
different weights and diameters may also be formed if the rules of
the U.S.G.A. are not an issue.
[0033] In a particular embodiment of the disclosure, the golf ball
has a dimple pattern that provides dimple coverage of 65% or more,
preferably 75% or more, and ore preferably about 80 to 85% or more
In another embodiment, there are from 250 to less than 500 dimples,
preferably from about 340 to about 440 dimples. The surface
geometry of the golf ball 10 is preferably a conventional dimple
pattern such as disclosed in U.S. Pat. No. 6,213,898 for a Golf
Ball With An Aerodynamic Surface On A Polyurethane Cover, which
pertinent parts are hereby incorporated by reference.
Alternatively, the surface geometry of the golf ball 10 may have a
non-dimple pattern such as disclosed in U.S. Pat. No. 6,290,615 for
A Golf Ball Having Tubular lattice Pattern, which pertinent parts
are hereby incorporated by reference.
[0034] Specifically, the arrangement and total number of dimples
are not critical and may be properly selected within ranges that
are well known. For example, the dimple arrangement may be an
octahedral, dodecahedral or icosahedral arrangement. The total
number of dimples is generally from about 250 to about 600, and
especially from about 300 to about 500. The golf balls of the
present invention may comprise circular or non-circular dimples or
any combination.
[0035] In a further embodiment, the golf ball typically is coated
with a durable, abrasion-resistant, relatively non-yellowing finish
coat or coats if necessary. The finish coat or coats may have some
optical brightener and/or pigment added to improve the brightness
or whiteness of the finished golf ball.
[0036] In one embodiment, from 0.001 to about 10% optical
brightener may be added to one or more of the finish coatings. If
desired, optical brightener may also be added to the cover
materials. One type of preferred finish coatings are solvent based
urethane coatings known in the art. It is also contemplated to
provide a transparent outer coating or layer on the final finished
golf ball.
[0037] Golf balls also typically include logos and other markings
printed onto the dimpled spherical surface of the ball. Paint,
typically clear paint, is applied for the purposes of protecting
the cover and improving the outer appearance before the ball is
completed as a commercial product. A white coating of one or two
layers, typically filled with titanium dioxide of either the
anatase or rutile type, may also be utilized.
[0038] Fillers are used to adjust the density, flex modulus, mold
release, and/or melt flow index of a layer. With some fillers, up
to about 200 parts by weight can be used. When the filler is for
adjustment of density or flex modulus of a layer, it is present in
an amount of at least 5 parts by weight based upon 100 parts by
weight of the layer.
[0039] A density adjusting filler is used to control the moment of
inertia, and thus the initial spin rate of the ball and spin decay.
The addition in one or more layers, and particularly in the outer
cover layer, of a filler with a lower specific gravity than the
resin composition results in a decrease in moment of inertia and a
higher initial spin rate than would result if no filler were used.
The addition in one or more of the cover layers, and particularly
in the outer cover layer, of a filler with a higher specific
gravity than the resin composition, results in an increase in
moment of inertia and a lower initial spin rate. High specific
gravity fillers are preferred as less volume is used to achieve the
desired inner or outer cover total weight. Nonreinforcing fillers
are also preferred as they have minimal effect on COR. Preferably,
the filler does not chemically react with the resin composition to
a substantial degree, although some reaction may occur when, for
example, zinc oxide is used in a shell layer which contains some
ionomer. The filler usually has a specific gravity which is at
least 0.05, and in specific embodiments at least 0.1, higher or
lower than the specific gravity of the layer composition. In
further embodiments, density adjusting fillers are used which have
specific gravities which are higher or lower than the specific
gravity of the resin composition by 0.2 or more or by 2.0 or
more.
[0040] A flex modulus adjusting filler is a filler which, e.g. when
used in an amount of 1 to 100 parts by weight based upon 100 parts
by weight of resin composition, will raise or lower the flex
modulus (ASTM D-790) of the resin composition by at least 1% and
preferably at least 5% as compared to the flex modulus of the resin
composition without the inclusion of the flex modulus adjusting
filler.
[0041] A mold release adjusting filler is a filler which allows for
the easier removal of a part from a mold and eliminates or reduces
the need for external release agents which otherwise could be
applied to the mold. A mold release adjusting filler typically is
used in an amount of up to about 2 weight percent based upon the
total weight of the layer.
[0042] A melt flow index adjusting filler is a filler which
increases or decreases the melt flow, or ease of processing, of the
composition.
[0043] If the component is a layer, it may contain coupling agents
that increase adhesion of materials within a particular layer, e.g.
to couple a filler to a resin composition, or between adjacent
layers. Non-limiting examples of coupling agents include titanates,
zirconates and silanes. Coupling agents typically are used in
amounts of 0.1 to 2 weight percent based upon the total weight of
the composition in which the coupling agent is included.
[0044] Fillers which may be employed in layers other than the outer
cover layer may be or are typically in a finely divided form, for
example, in a size generally less than about 20 mesh, preferably
less than about 100 mesh U.S. standard size, except for fibers and
flock, which are generally elongated. Flock and fiber sizes should
be small enough to facilitate processing. Filler particle size will
depend upon desired effect, cost, ease of addition, and dusting
considerations. The filler preferably is selected from the group
consisting of precipitated hydrated silica, clay, talc, asbestos,
glass fibers, aramid fibers, mica, calcium metasilicate, barium
sulfate, zinc sulfide, lithopone, silicates, silicon carbide,
diatomaceous earth, polyvinyl chloride, carbonates, metals, metal
alloys, tungsten carbide, metal oxides, metal stearates,
particulate carbonaceous materials, micro balloons, and
combinations thereof.
[0045] Specific embodiments of the disclosure will now be described
in detail. These examples are intended to be illustrative, and the
disclosure is not limited to the materials, conditions, or process
parameters set forth in these embodiments. All parts and
percentages are by weight unless otherwise indicated.
[0046] In an alternative embodiment of a golf ball 20, the boundary
layer 16 or cover layer 14 is comprised of a high acid (i.e.
greater than 16 weight percent acid) ionomer resin or high acid
ionomer blend. More preferably, the boundary layer 16 is comprised
of a blend of two or more high acid (i.e. greater than 16 weight
percent acid) ionomer resins neutralized to various extents by
different metal cations.
[0047] In an alternative embodiment of a golf ball 20, the boundary
layer 16 or cover layer 14 is comprised of a low acid (i.e. 16
weight percent acid or less) ionomer resin or low acid ionomer
blend. Preferably, the boundary layer 16 is comprised of a blend of
two or more low acid (i.e. 16 weight percent acid or less) ionomer
resins neutralized to various extents by different metal cations.
The boundary layer 16 compositions of the embodiments described
herein may include the high acid ionomers such as those developed
by E. I. DuPont de Nemours & Company under the SURLYN brand,
and by Exxon Corporation under the ESCOR or IOTEK brands, or blends
thereof. Examples of compositions which may be used as the boundary
layer 16 herein are set forth in detail in U.S. Pat. No. 5,688,869,
which is hereby incorporated by reference in its entirety. Of
course, the boundary layer 16 high acid ionomer compositions are
not limited in any way to those compositions set forth in said
patent. Those compositions are incorporated herein by way of
examples only.
[0048] The high acid ionomers which may be suitable for use in
formulating the boundary layer 16 compositions are ionic copolymers
which are the metal (such as sodium, zinc, magnesium, etc.) salts
of the reaction product of an olefin having from about 2 to 8
carbon atoms and an unsaturated monocarboxylic acid having from
about 3 to 8 carbon atoms. Preferably, the ionomeric resins are
copolymers of ethylene and either acrylic or methacrylic acid. In
some circumstances, an additional comonomer such as an acrylate
ester (for example, iso- or n-butylacrylate, etc.) can also be
included to produce a softer terpolymer. The carboxylic acid groups
of the copolymer are partially neutralized (for example,
approximately 10-100%, preferably 30-70%) by the metal ions. Each
of the high acid ionomer resins which may be included in the inner
layer cover compositions of the invention contains greater than 16%
by weight of a carboxylic acid, preferably from about 17% to about
25% by weight of a carboxylic acid, more preferably from about
18.5% to about 21.5% by weight of a carboxylic acid. Examples of
the high acid methacrylic acid based ionomers found suitable for
use in accordance with this invention include, but are not limited
to, SURLYN 8220 and 8240 (both formerly known as forms of SURLYN
AD-8422), SURLYN 9220 (zinc cation), SURLYN SEP-503-1 (zinc
cation), and SURLYN SEP-503-2 (magnesium cation). According to
DuPont, all of these ionomers contain from about 18.5 to about
21.5% by weight methacrylic acid. Examples of the high acid acrylic
acid based ionomers suitable for use in the present invention also
include, but are not limited to, the high acid ethylene acrylic
acid ionomers produced by Exxon such as Ex 1001, 1002, 959, 960,
989, 990, 1003, 1004, 1006, 1007, 993, and 994. In this regard,
ESCOR or IOTEK 959 is a sodium ion neutralized ethylene-acrylic
neutralized ethylene-acrylic acid copolymer. According to Exxon,
IOTEKS 959 and 960 contain from about 19.0 to about 21.0% by weight
acrylic acid with approximately 30 to about 70 percent of the acid
groups neutralized with sodium and zinc ions, respectively.
[0049] Furthermore, as a result of the previous development by the
assignee of this application of a number of high acid ionomers
neutralized to various extents by several different types of metal
cations, such as by manganese, lithium, potassium, calcium and
nickel cations, several high acid ionomers and/or high acid ionomer
blends besides sodium, zinc and magnesium high acid ionomers or
ionomer blends are also available for golf ball cover production.
It has been found that these additional cation neutralized high
acid ionomer blends produce boundary layer 16 compositions
exhibiting enhanced hardness and resilience due to synergies which
occur during processing. Consequently, these metal cation
neutralized high acid ionomer resins can be blended to produce
substantially higher C.O.R.'s than those produced by the low acid
ionomer boundary layer 16 compositions presently commercially
available.
[0050] More particularly, several metal cation neutralized high
acid ionomer resins have been produced by the assignee of this
invention by neutralizing, to various extents, high acid copolymers
of an alpha-olefin and an alpha, beta-unsaturated carboxylic acid
with a wide variety of different metal cation salts. It has been
found that numerous metal cation neutralized high acid ionomer
resins can be obtained by reacting a high acid copolymer (i.e. a
copolymer containing greater than 16% by weight acid, preferably
from about 17 to about 25 weight percent acid, and more preferably
about 20 weight percent acid), with a metal cation salt capable of
ionizing or neutralizing the copolymer to the extent desired (for
example, from about 10% to 90%).
[0051] The base copolymer is made up of greater than 16% by weight
of an alpha, beta-unsaturated carboxylic acid and an alpha-olefin.
Optionally, a softening comonomer can be included in the copolymer.
Generally, the alpha-olefin has from 2 to 10 carbon atoms and is
preferably ethylene, and the unsaturated carboxylic acid is a
carboxylic acid having from about 3 to 8 carbons. Examples of such
acids include acrylic acid, methacrylic acid, ethacrylic acid,
chloroacrylic acid, crotonic acid, maleic acid, fumaric acid, and
itaconic acid, with ethylene methacrylic acid being preferred.
[0052] The softening comonomer that can be optionally included in
the boundary layer 16 of the golf ball of the invention may be
selected from the group consisting of vinyl esters of aliphatic
carboxylic acids wherein the acids have 2 to 10 carbon atoms, vinyl
ethers wherein the alkyl groups contain 1 to 10 carbon atoms, and
alkyl acrylates or methacrylates wherein the alkyl group contains 1
to 10 carbon atoms. Suitable softening comonomers include vinyl
acetate, methyl acrylate, methyl methacrylate, ethyl acrylate,
ethyl methacrylate, butyl acrylate, butyl methacrylate, or the
like.
[0053] Consequently, examples of a number of copolymers suitable
for use to produce the high acid ionomers included in the present
invention include, but are not limited to, high acid embodiments of
an ethylene/acrylic acid copolymer, an ethylene/methacrylic acid
copolymer, an ethylene/itaconic acid copolymer, an ethylene/maleic
acid copolymer, an ethylene/methacrylic acid/vinyl acetate
copolymer, an ethylene/acrylic acid/vinyl alcohol copolymer, etc.
The base copolymer broadly contains greater than 16% by weight
unsaturated carboxylic acid, from about 39 to about 83% by weight
ethylene and from 0 to about 40% by weight of a softening
comonomer. Preferably, the copolymer contains about 20% by weight
unsaturated carboxylic acid and about 80% by weight ethylene. Most
preferably, the copolymer contains about 20% acrylic acid with the
remainder being ethylene.
[0054] The boundary layer 16 compositions may include the low acid
ionomers such as those developed and sold by E. I. DuPont de
Nemours & Company under the SURLYN and by Exxon Corporation
under the brands ESCOR and IOTEK, ionomers made in-situ, or blends
thereof.
[0055] Another embodiment of the boundary layer 16 comprises a
non-ionomeric thermoplastic material or thermoset material.
Suitable non-ionomeric materials include, but are not limited to,
metallocene catalyzed polyolefins or polyamides, polyamide/ionomer
blends, polyphenylene ether/ionomer blends, etc., which preferably
have a Shore D hardness of at least 60 (or a Shore C hardness of at
least about 90) and a flex modulus of greater than about 30,000
psi, preferably greater than about 50,000 psi, or other hardness
and flex modulus values which are comparable to the properties of
the ionomers described above. Other suitable materials include but
are not limited to, thermoplastic or thermosetting polyurethanes,
thermoplastic block polyesters, for example, a polyester elastomer
such as that marketed by DuPont under the brand HYTREL, or
thermoplastic block polyamides, for example, a polyether amide such
as that marketed by Elf Atochem S. A. under the brand PEBEX, a
blend of two or more non-ionomeric thermoplastic elastomers, or a
blend of one or more ionomers and one or more non-ionomeric
thermoplastic elastomers. These materials can be blended with the
ionomers described above in order to reduce cost relative to the
use of higher quantities of ionomer.
[0056] Additional materials suitable for use in the boundary layer
16 or cover layer 14 of the present invention include
polyurethanes. These are described in more detail below.
[0057] The cover layer 14 preferably has a thickness in the range
of 0.005 inch to about 0.15 inch, more preferably about 0.010 inch
to about 0.030 inch, and most preferably 0.010 inch to 0.020
inch.
[0058] The cover layer 14 preferably comprises a
polyurethane/polyurea with a Shore D hardness (plaque) of from
about 50 to about 75, more preferably from about 60 to about 70,
and most preferably from about 64.
[0059] A preferred quasi-prepolymer of the isocyanate component is
ISONATE 181 prepolymer available from Dow Plastics (Mondur PF from
Bayer may also be used). ISONATE 181 is a diphenylmethane
diisocyanate with glycol (typically diethylene glycol). ISONATE has
a nitrogen-oxygen-carbon ("NCO") group content of approximately
23.
[0060] A preferred diethyl-2,4-toluene-diamine is available from
Albemarle Corporation of Baton Rouge, La. under the tradename
ETHACURE.RTM. 100 or EHTACURE.RTM. 100 LC.
[0061] A preferred pigment material is PLASTICOLORS DR-10368.
[0062] A preferred polytetramethylene ether glycol of the poly
component is TERATHANE.RTM. 1000 polyether glycol from DuPont
Chemical (PolyTHF 1000 and 2000 from BASF may also be used).
TERATHANE.RTM. 1000 polyether glycol is a polytetramethylene ether
glycol which has a molecular weight of approximately 1000. Another
preferred polytetramethylene ether glycol of the poly component is
TERATHANE.RTM. 2000 polyether glycol from DuPont Chemical.
TERATHANE.RTM. 2000 polyether glycol is a polytetramethylene ether
glycol which has a molecular weight of approximately 2000.
[0063] From the foregoing it is believed that those skilled in the
pertinent art will recognize the meritorious advancement of this
invention and will readily understand that while the present
invention has been described in association with a preferred
embodiment thereof, and other embodiments illustrated in the
accompanying drawings, numerous changes, modifications and
substitutions of equivalents may be made therein without departing
from the spirit and scope of this invention which is intended to be
unlimited by the foregoing except as may appear in the following
appended claims. Therefore, the embodiments of the invention in
which an exclusive property or privilege is claimed are defined in
the following appended claims.
* * * * *