U.S. patent application number 13/404544 was filed with the patent office on 2013-08-29 for high performance golf ball comprising modified high mooney viscosity rubber.
This patent application is currently assigned to NIKE, Inc.. The applicant listed for this patent is Aaron Craig Bender, Thomas J. Kennedy, III, Seisuke Tomita, Bradley C. Tutmark. Invention is credited to Aaron Craig Bender, Thomas J. Kennedy, III, Seisuke Tomita, Bradley C. Tutmark.
Application Number | 20130225329 13/404544 |
Document ID | / |
Family ID | 49003487 |
Filed Date | 2013-08-29 |
United States Patent
Application |
20130225329 |
Kind Code |
A1 |
Tomita; Seisuke ; et
al. |
August 29, 2013 |
High Performance Golf Ball Comprising Modified High Mooney
Viscosity Rubber
Abstract
A high performance golf ball made in part of a modified high
Mooney viscosity rubber. The modified high Mooney viscosity rubber
has less than about 20 phr oil and is high Mooney viscosity rubber
having a Mooney viscosity at least about 40 blended with between
about 1 phr and about 10 phr of process oil and between about 0.05
phr and 5 phr of peptizing agent.
Inventors: |
Tomita; Seisuke; (Tokyo,
JP) ; Kennedy, III; Thomas J.; (Wilbraham, MA)
; Bender; Aaron Craig; (Portland, OR) ; Tutmark;
Bradley C.; (Aloha, OR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Tomita; Seisuke
Kennedy, III; Thomas J.
Bender; Aaron Craig
Tutmark; Bradley C. |
Tokyo
Wilbraham
Portland
Aloha |
MA
OR
OR |
JP
US
US
US |
|
|
Assignee: |
NIKE, Inc.
Beaverton
OR
|
Family ID: |
49003487 |
Appl. No.: |
13/404544 |
Filed: |
February 24, 2012 |
Current U.S.
Class: |
473/374 ;
473/351; 473/371; 473/378 |
Current CPC
Class: |
A63B 37/0039 20130101;
A63B 37/0074 20130101; A63B 37/0075 20130101; C08L 9/00 20130101;
A63B 37/0067 20130101; A63B 37/0076 20130101; A63B 37/0061
20130101; A63B 37/0003 20130101; A63B 37/006 20130101; A63B 37/0065
20130101; A63B 37/0051 20130101 |
Class at
Publication: |
473/374 ;
473/351; 473/371; 473/378 |
International
Class: |
A63B 37/06 20060101
A63B037/06; A63B 37/02 20060101 A63B037/02; A63B 37/12 20060101
A63B037/12; A63B 37/00 20060101 A63B037/00 |
Claims
1. A high performance golf ball comprising: a modified high Mooney
viscosity rubber having less than about 20 pounds per 100 pounds of
rubber (phr) of oil, the modified high Mooney viscosity rubber
comprising high Mooney viscosity rubber having a Mooney viscosity
at least about 40 blended with between about 1 phr and about 10 phr
of process oil and between about 0.05 phr and about 5 phr of a
peptizing agent.
2. The golf ball of claim 1, the golf ball further comprising a
core layer, wherein the modified high Mooney viscosity rubber is in
the core layer.
3. The golf ball of claim 1, the golf ball further comprising an
inner cover layer, wherein the modified high Mooney viscosity
rubber is in the inner cover layer.
4. The golf ball of claim 1, wherein the high Mooney viscosity
rubber is selected from the group consisting of polybutadiene
rubber, polyisoprene rubber, natural rubber, ethylene propylene
rubber, ethylene propylene diene rubber, styrene-butadiene rubber,
and blends thereof.
5. The golf ball of claim 4, wherein the high Mooney viscosity
rubber is polybutadiene rubber.
6. The golf ball of claim 5, wherein the polybutadiene rubber
comprises greater than about 90 percent cis structure.
7. The golf ball of claim 1, wherein the amount of the process oil
is between about 2 phr and about 7.5 phr.
8. The golf ball of claim 1, wherein the process oil is selected
from the group consisting of process oils, vegetable oils,
vulcanized or functionalized vegetable oils, oils from animals,
functionalized oils, and blends thereof.
9. The golf ball of claim 8, wherein the process oil is selected
from the group consisting of naphthenic oils, paraffinic oils, and
blends thereof.
10. The golf ball of claim 8, wherein the vulcanized or
functionalized vegetable oils are selected from the group
consisting of epoxidized soy bean oil, epoxidized linseed oil,
epoxidized alkyl oils, the reaction products of epoxidized oil with
a peroxide, an amine, a polyamide, or an isocyanate-containing
molecule, and blends thereof.
11. The golf ball of claim 10, wherein the functionalized vegetable
oil is epoxidized soy bean oil.
12. The golf ball of claim 4 wherein the peptizing agent is
pentachlorothiophenol.
13. The golf ball of claim 8 wherein the peptizing agent is
pentachlorothiophenol.
14. The golf ball of claim 2, the golf ball further comprising an
inner cover layer, wherein the inner cover layer comprises HNP.
15. The golf ball of claim 14, wherein the HNP is selected from the
group consisting of HPF1000, HPF2000, HPF AD1024, HPF AD1027, HPF
AD1030, HPF AD1035, HPF AD1040, and blends thereof.
16. The golf ball of claim 14, wherein the relative weight
proportions of the modified high Mooney viscosity polybutadiene
rubber to HNP in a blended product range from about 60:40 to about
99.5:0.5.
17. The golf ball of claim 16, wherein relative weight proportions
of the modified high Mooney viscosity polybutadiene rubber to HNP
in a blended product range from about 75:25 to about 99:1.
18. The golf ball of claim 2, wherein the golf ball further
comprises a layer essentially surrounding the core, the layer
comprising HNP.
19. The golf ball of claim 2, wherein the core consists essentially
of modified high Mooney viscosity polybutadiene rubber and the
layer consists essentially of HNP.
20. The golf ball of claim 3, the golf ball further comprising an
outer cover, the outer cover comprising polyurethane.
Description
BACKGROUND
[0001] The present disclosure relates generally to a golf ball
comprising modified high Mooney viscosity rubber. The disclosure
also relates to a high performance golf ball comprising the
modified high Mooney viscosity rubber in a core layer.
[0002] Golf balls are important sporting goods that have changed
with changes in technology. For example, balls were first made of
wood, and then by stuffing boiled, softened feathers into a leather
sack. The sack typically was painted white, and would tighten upon
drying. However, because the feather ball tended to absorb moisture
and to split, many balls were required to play a round. Also, these
feather balls were expensive as compared with wooden balls.
[0003] Both feather and wooden balls were in use until the gutta
percha ball was made. The gutta percha ball was relatively
inexpensive and easily manufactured. Also, the gutta percha ball
was fairly durable, as compared with the feather ball, performed
well because the surface could easily be roughened to improve
flight characteristics, and so became popular. However, the ball
exhibited a tendency to break up in flight.
[0004] Golf balls comprising other elastic materials then were
developed. For example, a golf ball having a rubber core and an
elastic thread wound tightly around the core was developed. The
winding was covered with gutta percha at first, but later with
balata. However, balata-covered golf balls often are damaged by
players who are less skilled at striking the ball. Thus, tougher
covers were developed, including in particular covers comprising a
Surlyn.RTM. compound or a polyurethane compound.
[0005] The interior structure of the golf ball has advanced, with
plastics and polymeric materials having properties and
characteristics appropriate for manufacture of high-quality,
high-performance, affordable golf balls. In particular, polymeric
materials having properties and characteristics appropriate for
golf ball manufacture have been developed. Such polymeric materials
include polyurethanes and ionomeric materials, including highly
neutralized acid polymers. Blended materials also are used to
manufacture other products.
[0006] However, the quest for such desirable golf balls sometimes
is sabotaged by processing techniques that diminish the preferred
properties and characteristics of the compositions used to form the
golf ball. For example, high Mooney viscosity polybutadiene rubber
has the properties and characteristics one would seek for a golf
ball core, including in particular, a high coefficient of
restitution (COR). The high viscosity exhibited by high Mooney
viscosity polybutadiene rubber makes it difficult to process. Thus,
significant stresses are placed on processing equipment, and the
period required to process the high Mooney viscosity polybutadiene
rubber to form part of a golf ball, particularly part of the core,
is long.
[0007] A typical way to reduce the viscosity of high Mooney
viscosity polybutadiene rubber is to incorporate oils and other
materials to reduce the viscosity of the high Mooney viscosity
polybutadiene rubber. Thus, extender oil and lubricant compositions
often are added to high Mooney viscosity rubber to ameliorate the
difficulties in processing and forming. Typically, such
compositions are added in large quantity, most typically greater
than about 30 phr, and often as much as 500 phr. However, adding
extender oil or such viscosity-reducing material in an amount
sufficient to make processing appreciably easier, typically greater
than about 30 phr, tends to reduce the COR and to degrade the
desired properties and characteristics of the rubber.
[0008] Other additives also have been used in an attempt to
ameliorate processing and forming difficulties with high Mooney
viscosity polybutadiene rubber without significantly degrading the
performance properties and characteristics sought. For example,
traditional plasticizers such as phthalate esters have been
utilized, but they are expensive and sometimes difficulty
compatible with high Mooney viscosity polybutadiene rubber.
Similarly, fatty acids and metal soaps also are expensive and tend
not to adhere well, but rather exhibit `waxy` behavior.
[0009] Another type of composition often used as a core layer in a
golf ball is the highly neutralized polymer, or HNP. These
materials have a high COR, but sometimes lack other properties and
characteristics sought for golf ball performance.
[0010] Therefore, there exists a need in the art for a
high-performance golf ball that includes components that are easily
and efficiently processed. Such a golf ball exhibits high
performance and can be produced without undue processing
difficulty.
SUMMARY
[0011] In one aspect, the disclosure provides a golf ball that
comprises modified high Mooney viscosity rubber.
[0012] In another aspect, the disclosure provides a high
performance golf ball comprising the modified high Mooney viscosity
rubber in a core layer.
[0013] In yet another aspect, the disclosure provides a high
performance golf ball comprising both modified high Mooney
viscosity rubber and HNP in separate core layers.
[0014] In still another aspect, the disclosure provides a high
performance golf ball comprising both modified high Mooney
viscosity rubber and HNP in separate core layers and an HNP cover
layer.
[0015] Other systems, methods, features, and advantages of the
invention will be, or will become, apparent to one of ordinary
skill in the art upon examination of the following figures and
detailed description. It is intended that all such additional
systems, methods, features and advantages be included within this
description and this summary, be within the scope of the invention,
and be protected by the following claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention can be better understood with reference to the
following drawings and description. The components in the figures
are not necessarily to scale, emphasis instead being placed upon
illustrating the principles of the invention. Moreover, in the
figures, like reference numerals designate corresponding parts
throughout the different views.
[0017] FIG. 1 shows a representative golf ball in accordance with
this disclosure, the golf ball being of a two-piece
construction;
[0018] FIG. 2 shows a second representative golf ball, having a
core, an inner cover layer, and an outer cover layer;
[0019] FIG. 3 shows a third representative golf ball, having an
inner core, an outer core layer, and a cover layer; and
[0020] FIG. 4 shows a fourth representative golf ball, having an
inner core, an outer core layer, an inner cover layer, and an outer
cover layer.
DETAILED DESCRIPTION
[0021] As used herein, unless otherwise stated, compression
deformation, hardness, COR, flexural modulus, and Vicat softening
temperature are measured as follows:
[0022] A. Compression deformation: The compression deformation
herein indicates the deformation amount of the ball, or any portion
thereof, under a force; specifically, when the force is increased
to become 130 kg from 10 kg, the deformation amount of the ball or
portion thereof under the force of 130 kg reduced by the
deformation amount of the ball or portion thereof under the force
of 10 kg is the compression deformation value of the ball or
portion thereof.
[0023] B. Hardness: Hardness of a golf ball layer is measured
generally in accordance with ASTM D-2240, but measured on the land
area of a curved surface of a molded ball.
[0024] C. Method of measuring COR: A golf ball for test is fired by
an air cannon at an initial velocity of 40 m/sec, and a speed
monitoring device is located over a distance of 0.6 to 0.9 meters
from the cannon. The golf ball strikes a steel plate positioned
about 1.2 meters away from the air cannon and rebounds through the
speed-monitoring device. The return velocity divided by the initial
velocity is the COR.
[0025] D. Flexural modulus: Measured in accordance with ASTM
D-790.
[0026] E. Vicat softening temperature: Measured in accordance with
ASTM D-1525.
[0027] F. Mooney viscosity is measured herein by a Mooney Shearing
Disk Viscometer in accordance with ASTM D1646. The viscometer is
run at a defined temperature, which is 100.degree. C. herein. The
resultant value, identified as (ML.sub.1+4 (100.degree. C.)) and
expressed as a number, is an indication of the torque on the
viscometer's rotating spindle within heated dies.
[0028] G. Compression often is measured with a device from ADC, and
typically is reported in millimeters (mm). An ADC compression
tester, commercially available from Automated Design Corp. in
Illinois, USA, can be used to carry out this determination. The ADC
compression tester can be set to apply a first load and obtain a
first deformation amount, and then, after a selected period, to
apply a second, typically higher load and determine a second
deformation amount. Thus, the first load herein is 10 kg, the
second load herein is 130 kg, and the compression deformation is
the difference between the second deformation and the first
deformation. Herein, this distance is reported in millimeters. The
compression can be reported as a distance, or as an equivalent to
other deformation measurement techniques, such as Atti
compression.
[0029] The disclosure provides a golf ball that comprises modified
high Mooney viscosity rubber. In particular, the disclosure
provides a high performance golf ball comprising the modified high
Mooney viscosity rubber in a core layer.
[0030] High Mooney viscosity rubber is defined herein as a rubber
having a Mooney viscosity value of at least about 40, typically at
least about 50. In embodiments of the disclosure, high Mooney
viscosity rubber is modified by addition of less than about 10 phr
(pounds per hundred pounds of rubber) of process oil and less than
about 5 phr peptizing agent to form modified high Mooney viscosity
rubber.
[0031] High Mooney viscosity rubber has desirable properties and
characteristics for use in golf balls. For example, high Mooney
viscosity rubber has high COR, low cold flow, and higher molecular
weight. Low cold flow and high molecular weight imbue the high
Mooney viscosity rubber with excellent durability. However, high
Mooney viscosity rubber typically is difficult to process because
both mixing and extruding are difficult. Also, forming a golf ball
layer from high Mooney viscosity rubber typically is difficult
because molding high Mooney viscosity rubber typically is
difficult.
[0032] The inventors have discovered that it is possible to use
only small amounts of process oil, i.e., less than about 10 phr, in
combination with less than about 5 phr peptizing agent to yield
modified high Mooney viscosity rubber. The inventors have
discovered that this combination provides processing and forming
advantages over unmodified high Mooney viscosity rubber while
maintaining most of the sought-after properties and
characteristics, particularly COR. Importantly, the inventors also
have discovered that judicious use of a combination of modified
high Mooney viscosity rubber and HNP in separate core layers
provides a golf ball core that yields excellent COR and a high
performance golf ball that can be made with reduced processing
difficulty.
[0033] In yet another aspect, therefore, the disclosure provides a
high performance golf ball comprising both modified high Mooney
viscosity rubber and HNP in separate core layers. The HNP further
ameliorates the reduction in COR caused by addition of the process
oil and provides additional hardness and resilience to the core
layers.
[0034] In still another aspect, the disclosure provides a high
performance golf ball comprising both modified high Mooney
viscosity rubber and HNP in separate core layers and an HNP cover
layer. The HNP cover layer provides not only high performance spin
control and an excellent flight path, but also excellent scuff
resistance.
[0035] In yet another aspect, the disclosure provides a high
performance golf ball comprising both modified high Mooney
viscosity rubber and HNP in separate core layers and a polyurethane
cover. Further, the polyurethane cover may be cross-linked or
otherwise treated to provide scuff resistance.
[0036] The disclosure relates to golf balls having 2 or more
layers. If the golf ball has only 2 layers, the core is modified
high Mooney viscosity rubber and the cover is HNP. However, it is
more typical for golf balls that benefit from this disclosure to
have at least 3 layers.
[0037] FIG. 1 illustrates a 2-layer or 2-piece golf ball 100 having
core 120 essentially surrounded by cover layer 110. In this golf
ball embodiment, core 120 comprises modified high Mooney viscosity
rubber and cover layer 110 comprises HNP or another suitable cover
material, such as polyurethane.
[0038] FIG. 2 illustrates a 3-piece golf ball 200 having a
relatively large core 230 essentially surrounded by inner cover
layer 220, which itself is encompassed within or essentially
surrounded by outer cover layer 210. In this golf ball embodiment,
core 230 comprises modified high Mooney viscosity rubber, inner
cover layer 220 typically comprises HNP, and outer cover layer 210
comprises HNP (whether the same as or different from the HNP used
in inner cover layer 220), polyurethane, or another cover layer
material.
[0039] FIG. 3 illustrates 3-piece golf ball 300 having a relatively
smaller inner core 330, outer core layer 320, and cover layer 310.
In this golf ball embodiment, inner core 330 comprises modified
high Mooney viscosity rubber, outer core layer 320 typically
comprises HNP, and cover layer 310 comprises HNP (whether the same
as or different from the HNP used in inner cover layer 320),
polyurethane, or another cover layer material.
[0040] FIG. 4 illustrates 4-piece golf ball 400 having inner core
440, outer core layer 430, inner cover layer 420, and outer cover
layer 410. In this golf ball embodiment, inner core 440 comprises
modified high Mooney viscosity rubber, outer core layer 430
typically comprises HNP, and cover layers 420 and 410 comprise
other cover layer materials, such as HNPs, ionomers, polyurethane,
and other materials. In another golf ball embodiment, inner core
440 comprises typical core material, including modified high Mooney
viscosity rubber, outer core layer 430 typically comprises HNP,
inner cover layer 420 comprises modified high Mooney viscosity
rubber, and outer cover layer 410 comprise other cover layer
materials, such as HNPs, ionomers, polyurethane, and other
materials.
[0041] Thus, in embodiments of the disclosure, modified high Mooney
viscosity rubber typically is used in the inner core, but also can
be used in the outer core layer, if present, and in the inner cover
layer, if present. Modified high Mooney viscosity rubber also can
be used in two layers of the same golf ball. Typically, modified
high Mooney viscosity rubber is not used as outer cover material
because of the tendency of the process oil to bloom and become
separated from the high Mooney viscosity rubber. There are
materials, such as maleic anhydride, silanes, and titanates, that
can be used to compatibilize the process oil and the high Mooney
viscosity rubber. However, the separation tendency typically is
better managed, and more easily managed, in a layer that is
essentially encompassed within another layer.
[0042] In embodiments of the disclosure, modified high Mooney
viscosity rubber comprises high Mooney viscosity rubber blended
with process oil and a peptizing agent. Although the inventors do
not wish to be bound by theory, it is believed that process oils
aid the processing and forming of the rubber by serving as a
physical peptizer that reduces viscosity without shortening rubber
chain length. Further, it is believed that a peptizing agent acts
as a chemical peptizer, shortening chain length by scission to
reduce viscosity. Process oils are present at less than about 10
phr, typically between about 1 phr and about 9 phr, more typically
between about 2 phr and about 8 phr, and most typically between
about 2 phr and 7.5 phr. Peptizing agents are present in an amount
between about 0.01 phr and about 5.0 phr, typically between about
0.1 phr and about 4 phr, and more typically between about 0.2 phr
and about 1 phr.
[0043] The quantity of oil disclosed herein is in addition to any
oils or similar lubricious materials that may have been added to
the high Mooney viscosity rubber as a component of or carrier for
another compound. For example, the skilled practitioner recognizes
not only that rubber may have a small amount of extender oil in it
as supplied, but also that some ingredients, additives, and
modifiers may be supplied in oil or associated with oil. Typically,
such materials are pulverulent compositions, and the amount of oil
so supplied is relatively small and produces no adverse effects in
the finished product. However, the potential exists for introducing
amounts that, when accumulated, exceed that amount of oil that may
produce adverse effects in finished product.
[0044] For example, the skilled practitioner is familiar with the
Crystex.RTM. family of sulfur delivery products. These products
comprise sulfur and oil in quantities between about 10 wt percent
and 30 wt percent, based on the weight of the Crystex.RTM. product.
Although the inventors do not wish to be bound by theory, it is
believed that this oil serves both to suppress the tendency of
pulverulent sulfur to fly into the air, causing a potential health
and safety hazard, and to aid in dispersion of the sulfur in the
rubber. Whereas the skilled practitioner recognizes that this
sulfur-containing product typically is not used in rubber to be
used in the manufacture of golf balls, Crystex.RTM. is a well-known
product that exemplifies this type of product. Oil may be
introduced as a dispersant and as a dust-reducing composition in
conjunction with sulfur and other pulverulent solids or other
materials that are difficult to blend with or disperse in rubber or
tend to become dispersed in air. Thus, this oil often is called
`dispersant oil`. Also, the rubber may be `extended` rubber, i.e.,
rubber already containing extender oil.
[0045] In embodiments of the disclosure, the total amount of oil in
rubber, i.e., the sum of process oil, dispersant oil, and extender
oil already present in the rubber, is less than about 20 phr,
typically between about 1 phr and about 18 phr, and more typically
between about 2 phr and about 15 phr. The amount of process oil is
less than about 10 phr, and typically is between about 1 phr and
about 9 phr in embodiments of the disclosure. In other embodiments
of the disclosure, process oil more typically is between about 2
phr and about 8 phr, most typically between about 2 phr and about
7.5 phr. Further, the amount of dispersant oil and extender oil
present typically is less than about 10 phr. If the amount of these
oils exceeds about 10 phr, the maximum amount of process oil
introduced in embodiments of the disclosure typically is limited to
that amount that will ensure that the total amount of oil does not
exceed about 20 phr. With the guidance provided herein, the skilled
practitioner will be able to select components of the rubber that
limit the amount of oil present in the rubber.
[0046] In this disclosure, high Mooney viscosity rubber is defined
as rubber having Mooney viscosity greater than about 40, or greater
than about 50, or greater than about 55, or greater than about 60,
or greater than about 65, or greater than about 70. Mooney
viscosity is measured as set forth in the definitions.
[0047] High Mooney viscosity rubber is selected from the group
consisting of polybutadiene rubber, polyisoprene rubber, natural
rubber, ethylene propylene rubber, ethylene propylene diene rubber,
styrene-butadiene rubber, and blends thereof, that have Mooney
viscosity value greater than about 40, or greater than about 50, or
greater than about 55, or greater than about 60, or greater than
about 65, or greater than about 70. In embodiments of the
disclosure, the high Mooney viscosity rubber comprises, in major
part, polybutadiene rubber. For convenience herein, the disclosure
will focus on high Mooney viscosity polybutadiene rubber, and the
modified high Mooney viscosity polybutadiene rubber resulting
therefrom upon addition of process oil and peptizing agent.
[0048] In embodiments of the disclosure, the high Mooney viscosity
polybutadiene rubber comprises high-cis high Mooney viscosity
polybutadiene rubber, typically neodymium-catalyzed polybutadiene
rubber. Cobalt-catalyzed and nickel-catalyzed versions also are
suitable.
[0049] The skilled practitioner recognizes that polybutadiene
rubber is available in various versions, including high-cis
(greater than about 92 percent cis structure, typically with less
than about 4 percent trans and less than about 4 percent vinyl);
low-cis (as little as about 35 percent cis structure) and vinyl,
all of which structures is suitable in embodiments of the
disclosure.
[0050] Typically, high-cis high Mooney viscosity polybutadiene
rubber is used in accordance with the disclosure herein.
Polybutadiene having primarily trans structure is not an elastic
product, but rather is a crystalline, plastic product. Therefore,
polybutadiene comprising primarily trans structure typically is not
used as a rubber (elastic) product and so would not be suitable for
use in this disclosure, although small amounts of crystalline trans
polybutadiene in elastomeric polybutadiene rubber are to be
expected, and do not adversely affect the properties and
characteristics of the elastic polybutadiene rubber product.
[0051] In embodiments of the disclosure, members of the Buna CB
family or series of polybutadiene rubber having a Mooney viscosity
greater than about 50, available from Lanxess USA, Texas, USA, are
suitably used. In particular, Buna CB 21, a highly linear
neodymium-catalyzed butadiene rubber having a Mooney viscosity of
73; Buna CB 22 and Buna Nd 60, each a highly linear
neodymium-catalyzed butadiene rubber having a Mooney viscosity of
63, and Buna CB 1221, a branched cobalt-catalyzed butadiene rubber
having a Mooney viscosity of 53, are suitable in embodiments of the
disclosure.
[0052] Other high Mooney viscosity polybutadiene rubbers suitable
for use in embodiments of the disclosure include LG BR1208, which
has a Mooney viscosity of 40 and is available from LG Chem, LTD,
Korea, and Kumho 60, which has a Mooney viscosity of 60 and is
available from Kumho, Korea.
[0053] The high Mooney viscosity polybutadiene rubber typically is
cured using a conventional curing process. Suitable curing
processes include, for example, peroxide curing, radiation curing,
and combinations thereof.
[0054] In one embodiment, the high Mooney viscosity polybutadiene
rubber is peroxide cured. Organic peroxides suitable as free
radical initiators include, for example, dicumyl peroxide (DCP);
n-butyl-4,4-di(t-butylperoxy)valerate;
1,1-di(t-butylperoxy)3,3,5-trimethylcyclohexane (TMCH);
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. Peroxide
free radical initiators are generally present in the rubber
compositions in an amount within the range having a lower limit of
0.05 phr, or 0.1 phr, or 0.25 phr, or 1 part, or 1.5 phr, and an
upper limit of 2.5 phr, or 3 phr, or 5 phr, or 6 phr, or 10 phr, or
15 phr.
[0055] Co-agents can be used with peroxides to improve the cure.
Suitable co-agents include, for example, metal salts of unsaturated
carboxylic acids having from 3 to 8 carbon atoms; unsaturated vinyl
compounds and polyfunctional monomers (for example,
trimethylolpropane trimethacrylate); phenylene bismaleimide; and
combinations thereof. Particularly suitable metal salts include,
for example, one or more metal salts of acrylates, diacrylates,
methacrylates, and dimethacrylates, wherein the metal is selected
from magnesium, calcium, zinc, aluminum, lithium, and nickel. In a
particular embodiment, the co-agent is selected from zinc salts of
acrylates, diacrylates, methacrylates, and dimethacrylates. In
another particular embodiment, the co-agent is zinc diacrylate
(ZDA). When the agent is zinc diacrylate and/or zinc
dimethacrylate, the co-agent is typically included in the rubber
composition in an amount within the range having a lower limit of 1
phr, or 5 phr, or 10 phr, or 20 phr, and an upper limit of 25 phr,
or 30 phr, or 35 phr, or 40 phr, or 50 phr, or 60 phr. When one or
more less active co-agents are used, such as zinc monomethacrylate
and various liquid acrylates and methacrylates, the amount of less
active co-agent used may be the same as or higher than for zinc
diacrylate and zinc dimethacrylate co-agents.
[0056] High energy radiation sources capable of generating free
radicals may also be used to crosslink the high Mooney viscosity
polybutadiene rubber. Suitable examples of such radiation sources
include, for example, electron beams, ultra-violet radiation, gamma
radiation, X-ray radiation, infrared radiation, heat, and
combinations thereof. Free radical initiators known in the art also
may be used.
[0057] With the guidance provided herein, the skilled practitioner
will be able to select a curing agent or combinations thereof to
cure the high Mooney viscosity polybutadiene rubber.
[0058] Other compositions may be added to the high Mooney viscosity
polybutadiene rubber. For example, a cis-to-trans conversion
compound, such as halogenated organosulfur compounds, may be added.
Anti-oxidant compounds also may be present. The skilled
practitioner is familiar with these compounds and can select
suitable compounds and the amount thereof to provide the desired
result.
[0059] Further, as described above, the disclosure relates to golf
balls having at least 2 layers, or pieces. Thus, although
discussion herein is directed to a 4-piece ball for convenience,
the disclosure is directed to golf balls having at least 2-layers,
and as many as 5, 6, or 7 layers, or more. The number of layers in
the golf ball is limited only by any rules extant at the time of
manufacture if the ball is to be "conforming," i.e., meet the rules
of a governing body such as the USGA.
[0060] Process oil added to the high Mooney viscosity polybutadiene
rubber is selected from the group consisting of process oils,
vegetable oils, vulcanized or functionalized vegetable oils, oils
from animals, functionalized oils, and blends thereof. Typically,
process oil is selected from the group consisting of process oils,
vegetable oils, functionalized vegetable oils, and blends thereof.
More typically, process oil is vegetable oil, functionalized
vegetable oil, and blends thereof.
[0061] Suitable process oils include, for example, aromatic oils,
naphthenic oils, and paraffinic oils, as classified by ASTM D2226.
As the skilled practitioner recognizes, such oils typically are a
blend of aromatic, naphthenic, and paraffinic oils, and are
classified by the predominant types of properties and
characteristics of the oil. In an embodiment, the process oil is
selected from paraffinic oil, naphthenic oil, and blends thereof.
Aromatic oils lower viscosity more than the same quantity of
naphthenic oil or paraffinic oil, but may cause concern over
potential health threats.
[0062] Aromatic oils include the Sundex.RTM. family of aromatic
oils available from many sources, including American Lubricants
& Chemicals, LLC, in Ohio, USA. Particularly suitable
paraffinic and naphthenic oils include, for example, Sunpar.RTM.
paraffinic oil, a family of oils commercially available from
Sunoco, Inc. of Pennsylvania, USA and HollyFrontier Refining and
Marketing; Paralux.RTM. paraffinic oil, a family of oils
commercially available from Chevron Corporation of California, USA;
Unithene.RTM. naphthenic oil, a family of oils commercially
available from Ergon, Inc. of Mississippi, USA; and the family of
oils commercially available from Idemitsu USA under the name Diana
Process Oil PS.
[0063] In some embodiments, suitable oils also include low PCA/PHA
(polycyclic aromatic/polyaromatic hydrocarbon) oils, including mild
extraction solvates (MES), treated distillate aromatic extracts
(TDAE), and heavy naphthenic oils. Suitable low PCA oils are
further disclosed in U.S. Pat. No. 6,977,276 (column 4, line 31 up
to and including column 6, line 27), the entire disclosure of which
is hereby incorporated herein by reference. Hydrogenated naphthenic
oils, including those disclosed in U.S. Pat. No. 6,939,910, the
entire disclosure of which is hereby incorporated herein by
reference, also are suitable in some embodiments.
[0064] Suitable vegetable oils for use in embodiments of the
disclosure include, for example, rapeseed oil, castor oil, linseed
oil, soybean oil, and tung oil. Suitable vulcanized vegetable oils
include, for example, semi-translucent factice, black factice, and
brown factice; in particular, "F14" and "F17" sulfur vulcanized
rapeseed oils, "K14D" sulfur vulcanized modified fatty acids,
"Gloria 17" sulfur vulcanized rapeseed oil, "Hamburg 4" partially
hydrogenated rapeseed oil, and "WP" peroxide crosslinked modified
castor oil free of sulfur and chlorine, all of which are
commercially available from R.T. Vanderbilt Company, Inc. of
Norwalk, Conn.
[0065] Embodiments of the disclosure also use functionalized
vegetable oil. Functionalized vegetable oils include, for example,
epoxidized soy bean oil, epoxidized linseed oil, and epoxidized
alkyl oils. One suitable epoxidized soy bean oil family is
available from Arkema Inc., of Pennsylvania, USA, under the
tradename Vikoflex.RTM.. Functionalized vegetable oils also include
the reaction product of an epoxidized oil with a peroxide, an
amine, a polyamide, or an isocyanate-containing molecule. Although
the inventors do not wish to be bound by theory, epoxidized oil and
functionalized oils can be incorporated into the polymeric
structure of the modified high Mooney viscosity polybutadiene
rubber. In any event, functionalized oils exhibit significantly
less motility of the oil, thus reducing blooming of the oil, i.e.,
reducing separation of the oil from the modified high Mooney
viscosity polybutadiene rubber.
[0066] Functionalizing moieties typically are present in an amount
between about 0.5 phr and 10 phr, more typically between about 1
phr and 5 phr, and even more particularly between about 1.25 and 3
phr. Also, the functionalizing moiety typically comprises between
about 5 wt percent and about 20 wt percent, based on the weight of
the functionalized oil, more typically between about 8 wt percent
and about 12 wt percent, based on the weight of the functionalized
oil.
[0067] Suitable oils from animals include, for example, whale oil
and fish oil.
[0068] In embodiments of the disclosure, suitable peptizing agents
include compositions that contain an organic sulfur compound and/or
a metal-containing organic sulfur compound in addition to the base
rubber and the unsaturated carboxylic acid metal salt. Examples of
the organic sulfur compound include thiophenols such as
pentachlorothiophenol, 4-butyl-o-thiocresol,
4-t-butyl-p-thiocresol, and 2-benzamidothiophenol, thiocarboxylic
acids such as thio-benzoic acid, and sulfides such as dixylyl
disulfide, di(o-benzamidophenyl)disulfide and alkylated phenol
sulfides. Examples of the metal-containing organic sulfur compound
include zinc salts of the above-mentioned thiophenols and
thiocarboxylic acids. The sulfur compounds may be used alone or in
admixture of two or more. The sulfur compound is preferably blended
in amounts of from about 0.05 to about 2 parts by weight, more
preferably from about 0.1 to about 0.5 parts by weight per 100
parts by weight of the base rubber.
[0069] Typically, the peptizing agents are known conventionally as
"soft and fast" agents. The conventional soft and fast agent is
present in an amount within a range having a lower limit of about
0.05 phr or about 0.1 phr or about 0.2 phr or about 0.5 phr and an
upper limit of about 0.05 phr or about 1 phr or about 2 phr or
about 3 phr or about 5 phr. As used herein, "soft and fast agent"
means any compound or a blend thereof that is capable of making a
core softer (have a lower compression) at a constant COR, making a
core faster (have a higher COR at equal compression), or a
combination thereof, when compared to a core equivalently prepared
without a soft and fast agent. Suitable conventional soft and fast
agents include, but are not limited to, those selected from
organosulfur and metal-containing organosulfur compounds, organic
sulfur compounds, including mono-, di-, and poly-sulfides, thiol,
and mercapto compounds, inorganic sulfide compounds, Group VIA
compounds, substituted or unsubstituted aromatic organic compounds
that do not contain sulfur or metal, aromatic organometallic
compounds, and mixtures thereof.
[0070] Additional suitable soft and fast agents, or peptizing
agents, include organosulfur compounds, such as the thiophenols,
including pentafluorothiophenol; 2-fluorothiophenol;
3-fluorothiophenol; 4-fluorothiophenol; 2,3-fluorothiophenol;
2,4-fluorothiophenol; 3,4-fluorothiophenol; 3,5-fluorothiophenol
2,3,4-fluorothiophenol; 3,4,5-fluorothiophenol;
2,3,4,5-tetrafluorothiophenol; 2,3,5,6-tetrafluorothiophenol;
4-chlorotetrafluorothiophenol; pentachlorothiophenol;
2-chlorothiophenol; 3-chlorothiophenol; 4-chlorothiophenol;
2,3-chlorothiophenol; 2,4-chlorothiophenol; 3,4-chlorothiophenol;
3,5-chlorothiophenol; 2,3,4-chlorothiophenol;
3,4,5-chlorothiophenol; 2,3,4,5-tetrachlorothiophenol;
2,3,5,6-tetrachlorothiophenol; pentabromothiophenol;
2-bromothiophenol; 3-bromothiophenol; 4-bromothiophenol;
2,3-bromothiophenol; 2,4-bromothiophenol; 3,4-bromothiophenol;
3,5-bromothiophenol; 2,3,4-bromothiophenol; 3,4,5-bromothiophenol;
2,3,4,5-tetrabromothiophenol; 2,3,5,6-tetrabromothiophenol;
pentaiodothiophenol; 2-iodothiophenol; 3-iodothiophenol;
4-iodothiophenol; 2,3-iodothiophenol; 2,4-iodothiophenol;
3,4-iodothiophenol; 3,5-iodothiophenol; 2,3,4-iodothiophenol;
3,4,5-iodothiophenol; 2,3,4,5-tetraiodothiophenol;
2,3,5,6-tetraiodothiophenol; zinc salts thereof; non-metal salts
thereof, for example, ammonium salt of pentachlorothiophenol;
magnesium pentachlorothiophenol; cobalt pentachlorothiophenol; and
combinations thereof.
[0071] Suitable metal-containing organosulfur compounds include,
but are not limited to, cadmium, copper, lead, and tellurium
analogs of diethyldithiocarbamate, diamyldithiocarbamate, and
dimethyldithiocarbamate, and combinations thereof. Additional
examples are disclosed in U.S. Pat. No. 7,005,479, the entire
disclosure of which is hereby incorporated herein by reference.
[0072] Suitable disulfides include, but are not limited to,
4,4'-diphenyl disulfide; 4,4'-ditolyl disulfide; 4,4'-dixylyl
disulfide; 2,2'-benzamido diphenyl disulfide;
bis(2-aminophenyl)disulfide; bis(4-aminophenyl)disulfide;
bis(3-aminophenyl)disulfide; 2,2'-bis(4-aminonaphthyl)disulfide;
2,2'-bis(3-aminonaphthyl)disulfide;
2,2'-bis(4-aminonaphthyl)disulfide;
2,2'-bis(5-aminonaphthyl)disulfide;
2,2'-bis(6-aminonaphthyl)disulfide;
2,2'-bis(7-aminonaphthyl)disulfide;
2,2'-bis(8-aminonaphthyl)disulfide;
1,1'-bis(2-aminonaphthyl)disulfide;
1,1'-bis(3-aminonaphthyl)disulfide;
1,1'-bis(3-aminonaphthyl)disulfide;
1,1'-bis(4-aminonaphthyl)disulfide;
1,1'-bis(5-aminonaphthyl)disulfide;
1,1'-bis(6-aminonaphthyl)disulfide;
1,1'-bis(7-aminonaphthyl)disulfide;
1,1'-bis(8-aminonaphthyl)disulfide;
1,2'-diamino-1,2'-dithiodinaphthalene;
2,3'-diamino-1,2'-dithiodinaphthalene;
bis(4-chlorophenyl)disulfide; bis(2-chlorophenyl)disulfide;
bis(3-chlorophenyl)disulfide; bis(4-bromophenyl)disulfide;
bis(2-bromophenyl)disulfide; bis(3-bromophenyl)disulfide;
bis(4-fluorophenyl)disulfide; bis(4-iodophenyl)disulfide;
bis(2,5-dichlorophenyl)disulfide; bis(3,5-dichlorophenyl)disulfide;
bis(2,4-dichlorophenyl)disulfide; bis(2,6-dichlorophenyl)disulfide;
bis(2,5-dibromophenyl)disulfide; bis(3,5-dibromophenyl)disulfide;
bis(2-chloro-5-bromophenyl)disulfide;
bis(2,4,6-trichlorophenyl)disulfide;
bis(2,3,4,5,6-pentachlorophenyl)disulfide;
bis(4-cyanophenyl)disulfide; bis(2-cyanophenyl)disulfide;
bis(4-nitrophenyl)disulfide; bis(2-nitrophenyl)disulfide;
2,2'-dithiobenzoic acid ethylester; 2,2'-dithiobenzoic acid
methylester; 2,2'-dithiobenzoic acid; 4,4'-dithiobenzoic acid
ethylester; bis(4-acetylphenyl)disulfide;
bis(2-acetylphenyl)disulfide; bis(4-formylphenyl)disulfide;
bis(4-carbamoylphenyl)disulfide; 1,1'-dinaphthyl disulfide;
2,2'-dinaphthyl disulfide; 1,2'-dinaphthyl disulfide;
2,2'-bis(1-chlorodinaphthyl)disulfide;
2,2'-bis(1-bromonaphthyl)disulfide;
1,1'-bis(2-chloronaphthyl)disulfide;
2,2'-bis(1-cyanonaphthyl)disulfide;
2,2'-bis(1-acetylnaphthyl)disulfide; and the like; and combinations
thereof.
[0073] Suitable inorganic sulfide compounds include, but are not
limited to, titanium sulfide, manganese sulfide, and sulfide
analogs of iron, calcium, cobalt, molybdenum, tungsten, copper,
selenium, yttrium, zinc, tin, and bismuth.
[0074] In particular, as noted herein, especially suitable
peptizing agents, or soft and fast agents, for use in embodiments
of the disclosure include, but are not limited to, zinc
pentachlorothiophenol, pentachlorothiophenol, ditolyl disulfide,
diphenyl disulfide, dixylyl disulfide, and mixtures thereof. The
soft and fast agent component may also be a blend of an
organosulfur compound and an inorganic sulfide compound.
[0075] Typically, the halogenated thiophenol peptizing agent is
pentachlorothiophenol, which is commercially available in salt or
neat form, or under the tradename STRUKTOL.RTM., a clay-based
carrier containing, in one form, pentachlorothiophenol (PCTP)
loaded at 45 percent. STRUKTOL.RTM. is commercially available from
Struktol Company of America of Ohio. PCTP is commercially available
in neat form and in the zinc salt form from eChinachem of
California, US. Suitable organosulfur compounds are further
disclosed, for example, in U.S. Pat. Nos. 6,635,716, 6,919,393,
7,005,479 and 7,148,279, the entire disclosures of which are hereby
incorporated herein by reference.
[0076] Further, in embodiments of the disclosure, activators may be
used to accelerate peptization by starting the process at a lower
temperature. Activators are chelates, or complexes, of ketoxime,
phthalocyanine, or acetylacetone with metals such as iron, cobalt,
nickel, or copper. Typically, the metal is iron. Because these
activator compounds (chelates, or complexes) are highly effective,
only small amounts are present with the peptizing agent.
[0077] The process oil and peptizing agent are mixed with high
Mooney viscosity polybutadiene rubber to form modified high Mooney
viscosity polybutadiene rubber in any suitable way. In some
embodiments of the disclosure, the process oil, peptizing agent,
and high Mooney viscosity polybutadiene rubber are kneaded or
melt-blended in any suitable manner. Suitable equipment for
blending the high Mooney viscosity polybutadiene rubber with the
process oil and peptizing agent in accordance with this disclosure
includes a twin screw extruder, a Banbury-type mixer, a two-roll
mill (also known as a two-roll sheeter), or another manner of
kneading the fairly stiff high Mooney viscosity polybutadiene
rubber with the oil. Typically, kneading with a Banbury-type mixer,
a two-roll mill, or any suitable kneading device is used to blend
process oil and peptizing agent with high Mooney viscosity
polybutadiene rubber.
[0078] In embodiments of the disclosure, the components are heated
before introducing each to the kneader, two-roll mill, or other
mixing device. The high Mooney viscosity polybutadiene rubber
should be heated to a temperature below the scorch point, and the
process oil should be heated to a temperature below the smoke
point. The peptizing agent also can be heated, as appropriate. In
this way, the time and significant energy input required for mixing
the components will be reduced without reducing the quality of the
product.
[0079] In embodiments of the disclosure, the modified high Mooney
viscosity polybutadiene rubber is used in parts of a golf ball
having at least 2 layers, typically in a golf ball having at least
3 layers, or pieces, and more typically in a golf ball having at
least 4 layers. Typically, modified high Mooney viscosity
polybutadiene rubber of the disclosure forms the core of a golf
ball having at least 3 layers, or pieces, such as in core 230 of
golf ball 200; core 330 of golf ball 300; and core 440 of golf ball
400. Embodiments of the disclosure also include golf balls having a
core comprising modified high Mooney viscosity polybutadiene rubber
and having 5 or more layers.
[0080] The inventors have discovered that substantially enclosing
or substantially encompassing the modified high Mooney viscosity
polybutadiene rubber core with a layer of HNP is particularly
effective in forming a core or golf ball portion that has high COR.
Thus, embodiments of the disclosure having a core comprising
modified high Mooney viscosity polybutadiene rubber in the core
advantageously have a cover 110 (two-piece), inner cover 220
(three-piece), outer core 320 (three-piece), or inner cover 430
(four-piece) comprising an HNP.
[0081] HNPs suitable for use in embodiments of the disclosure
include highly neutralized terpolymer ionomers. HPF resins such as
HPF1000, HPF2000, HPF AD1024, HPF AD1027, HPF AD1030, HPF AD1035,
HPF AD1040, and other members of the HPF family of HNPs produced by
E. I. DuPont de Nemours and Company, are exemplary of HNPs suitably
used in embodiments of the disclosure. With the guidance provided
herein, the skilled practitioner will be able to identify suitable
HNPs to use to substantially encompass a core comprising modified
high Mooney viscosity polybutadiene rubber disclosed herein.
[0082] Modified high Mooney viscosity polybutadiene rubber of
embodiments of the disclosure also can be used to form an outer
core layer (320 or 430) or an inner cover layer (220 or 420), also
known as a mantle layer. Because the modified high Mooney viscosity
polybutadiene rubber is dense, a thin inner cover layer may be
useful in controlling spin and providing a high MOI golf ball.
[0083] For any arrangement of layers not specifically mentioned
herein, any layer may be made of any material suitable for the
purpose. For example, an outer cover layer should be tough and
resistant to scuffing. Thus, thermoplastic polyurethane (TPU) and
thermoset polyurethane are suitable for use in outer cover layers,
as are HNP and ionomers. Thermoplastic polyurethane that is not
scuff resistant without more can be treated to harden the surface,
such as by a surface treatment. Suitable ionomers include members
of the Surlyn.RTM. family of ionomeric polymers produced by E. I.
DuPont de Nemours and Company and members of the Lotek.RTM. family
of products produced by ExxonMobil Chemical Corporation.
[0084] The inventors also have discovered that modified high Mooney
viscosity polybutadiene rubber of this disclosure can be blended
with HNP to form a blended material that can be used in any layer
the modified high Mooney viscosity polybutadiene rubber can be
used. The blend has a high COR and is therefore particularly suited
to serve as a core, particularly as an outer core, in a high
performance golf ball. The blend may have a slightly higher density
than the modified high Mooney viscosity polybutadiene rubber, and
therefore also may form a suitable mantle (inner cover) layer.
[0085] The relative weight proportions of the modified high Mooney
viscosity polybutadiene rubber to HNP in a blended product range
from about 60:40 to about 99.5:0.5, typically from about 70:30 to
about 99:1, and more typically from about 75:25 to about 99:1.
[0086] The modified high Mooney viscosity polybutadiene rubber and
the HNP can be mixed in the same way the modified high Mooney
viscosity polybutadiene rubber is made, i.e., on a two-roll sheeter
or other kneading device. A compatibilizer or linker for the rubber
and the HNP likely would be required to form a coherent blend of
these components.
[0087] The modified high Mooney viscosity polybutadiene rubber
disclosed herein, and the blend of modified high Mooney viscosity
polybutadiene rubber with HNP, also may be suitably used as an
outer cover layer. If the modified high Mooney viscosity
polybutadiene rubber or the blend is used as an outer cover layer,
it is typical to ensure that the process oil does not `bloom` and
separate from the high Mooney viscosity polybutadiene rubber. In
that case, and in any other circumstance in which it is important
to maintain excellent compatibility, a compatibilizer can be
employed.
[0088] Compatibilizers include maleic anhydride, silanes, and
titanates. The skilled practitioner recognizes that the silanes
have the general formula Si.sub.nH.sub.2n+2. Typically, n is less
than about 8, as larger molecules are only difficulty made. The
titanates are compounds known to the skilled practitioner. For
example, the Ken-React.RTM. family of titanate coupling agents,
available from Kenrich Petrochemical, Inc., of New Jersey, USA, are
suitable titanates. Suitable titanates include monoalkoxy
titanates, such as KR.RTM. TTS (Titanium IV 2-propanolato, tris
isooctadecanoato-O) and KR 7 (Titanium IV bis
2-methyl-2-propenoato-O, isooctadecanoato-O 2-propanolato);
oxyacetate chelate titanates, such as KR.RTM. 134S (Titanium IV
bis[4-(2-phenyl)-2-propyl-2]phenolato, oxoethylenediolato) and KR
138S (Titanium IV bis(dioctyl)pyrophosphato-O, oxoethylenediolato,
(adduct), (dioctyl)(hydrogen)phosphite); A,B ethylene chelate
titanates, such as KR.RTM. 212 (Titanium IV
bis(dioctyl)phosphato-O, ethylenediolato) and KR 238S (Titanium IV
bis(dioctyl)pyrophosphato-O, ethylenediolato (adduct),
bis(dioctyl)hydrogen phosphite); quaternary titanates, such as
KR.RTM. 138D (Titanium IV bis(dioctyl)pyrophosphato-O,
oxoethylenediolato, (adduct) 2 moles of
2-N,N-dimethylamino-2-methylpropanol) and KR 158D (Titanium IV
bis(butyl methyl)pyrophosphato-O, (adduct) 2 moles
2-N,N-dimethylamino-2-methylpropanol); coordinate titanates, such
as KR.RTM. 41B (Titanium IV tetrakis 2-propanolato, adduct 2 moles
(dioctyl)hydrogen phosphate) and KR 46B (Titanium IV tetrakis
octanolato adduct 2 moles (di-tridecyl)hydrogen phosphite);
neoalkoxy titanates, such as LICA.RTM. 01 (Titanium IV 2,2(bis
2-propenolatomethyl)butanolato, tris neodecanoato-O) and LICA 09
(Titanium IV 2,2(bis 2-propenolatomethyl)butanolato,
tris(dodecyl)benzenesulfonato-O); and cycloheteroatom titanates,
such as KR.RTM. OPPR (Titanium IV bis octanolato,
cyclo(dioctyl)pyrophosphato-O,O) and KR OPP2 (Titanium IV bis
cyclo(dioctyl)pyrophosphato-O,O). With the guidance provided
herein, the skilled practitioner will be able to identify suitable
titanates for use in embodiments of the disclosure.
[0089] The skilled practitioner recognizes that the layers, or
pieces, also may include further components such as fillers and/or
additives. Fillers and additives may be used based on any of a
variety of desired characteristics, such as enhancement of physical
properties, UV light resistance, and other properties. For example,
to improve UV light resistance, a light stabilizer is added. Light
stabilizers may include hindered amines, UV stabilizers, or a
mixture thereof.
[0090] Inorganic or organic fillers can be also added to any layer.
Suitable inorganic fillers may include silicate minerals, metal
oxides, metal salts, clays, metal silicates, glass fibers, natural
fibrous minerals, synthetic fibrous minerals or a mixture thereof.
Suitable organic fillers may include carbon black, fullerene and/or
carbon nanotubes, melamine colophony, cellulose fibers, polyamide
fibers, polyacrylonitrile fibers, polyurethane fibers, polyester
fibers based on aromatic and/aliphatic dicarboxylic acid esters,
carbon fibers or a mixture thereof. The inorganic and organic
fillers may be used individually or as a mixture thereof. The total
amount of the filler may be from about 0.5 to about 50 percent by
weight of the layer.
[0091] Other density adjusting agents, such as hollow beads that
have a low density, also may be used in selected layers.
[0092] The skilled practitioner recognizes that these additives,
including in particular the density adjusters, affect the
performance properties and characteristics of the layer. Thus, the
amount of any fillers may not exceed that amount that adversely
affects the performance of the golf ball.
[0093] Flame retardants may also be used to improve the flame
resistance of any layer, and particularly of thermoplastic
polyurethane. Suitable flame retardants may include organic
phosphates, metal phosphates, metal polyphosphates, metal oxides
(such as aluminum oxide hydrate, antimony trioxide, arsenic oxide),
metal salts (such as calcium sulfate, expandable graphite), and
cyanuric acid derivatives (such as melamine cyanurate). These flame
retardants may be used individually or as a mixture thereof, and
the total amount of the flame retardant may be from about 10 to
about 35 percent by weight of a polyurethane component, for
example.
[0094] To improve toughness and compression rebound of
thermoplastic polyurethane elastomer, the thermoplastic
polyurethane elastomer may include at least one dispersant, such as
a monomer or oligomer comprising unsaturated bonds. Examples of
suitable monomers include styrene, acrylic esters; suitable
oligomers include di- and tri-acrylates/methacrylates, ester
acrylates/methacrylates, urethane, or urea
acrylates/methacrylates.
[0095] The outermost layer of a golf ball also may include at least
one white pigment to aid in better visibility. The white pigment
may be selected from the group consisting of titanium dioxide, zinc
oxide or a mixture thereof.
[0096] With the guidance provided herein, the skilled practitioner
will be able to select additives for each layer or piece of the
golf ball.
Examples
[0097] Nine golf ball cores were made and tested for selected
performance properties and characteristics. The effects of process
oil loading, process oil type, high Mooney viscosity polybutadiene
rubber type, and filler type were studied. The compositions of the
golf ball cores was as follows in Table 1, and the proportions and
identities of the high Mooney viscosity polybutadiene rubbers and
process oils were as set forth in Table 2:
TABLE-US-00001 TABLE 1 Compositions of Golf Balls Recipe 1 2
Rubber, pounds 100 100 Zinc diacrylate, phr 23.6 23.6 Zinc oxide,
phr 23.2 6.5 Zinc stearate, phr 3 3 Barium sulfate, phr -- 17
Dicumyl peroxide, phr 0.3 0.3 1,1-di(t-butylperoxy)3,3,5- 0.3 0.3
trimethylcyclohexane (TMCH), phr
TABLE-US-00002 TABLE 2 Golf ball core Proportions Golf Rubber
Process Process oil Ball Recipe type oil type amount, phr 1 1
BR1208 None 0 2 1 BR1208 Sunpar 150 7.5 3 1 BR1208 Sunpar 150 15 4
2 BR1208 None 0 5 2 K60 None 0 6 2 K60 32 7.5 7 2 K60 32 15 8 2 K60
Sunpar 150 15 9 2 K60 Sunpar 2280 15
[0098] BR1208, available from LG Chem, has a Mooney viscosity of
40. K60 is Kumho 60, available from Kumho. K60 has a Mooney
viscosity of 60. Each of the process oils is a paraffinic process
oil.
[0099] The cores were prepared by curing the rubber for 8 minutes
at 327.degree. F.
[0100] Each of the golf ball cores was tested to determine
Compression (ADC machine), COR, and approximate weight. The results
were summarized in Table 3, as follows:
TABLE-US-00003 TABLE 3 Performance properties and characteristics
Golf Compression Weight, ball core (ADC), mm COR grams 1 3.96
0.7832 39.5 2 4.99 0.7553 38.9 3 6.45 0.7278 38.5 4 4.12 0.7794
39.5 5 3.88 0.7889 39.3 6 4.98 0.7573 38.6 7 5.84 0.7401 38.3 8
6.09 0.7327 38.3 9 6.59 0.7221 38.3
[0101] As can be seen from this information, the increase in ADC
compression values as process oil loading increases, the reduction
in COR as process oil loading increases, and the reduction in COR
as ADC compression increases were essentially linear for each
combination of process oil and high Mooney viscosity polybutadiene
rubber type. Although the inventors do not wish to be bound by
theory, performance decreases are the consequence of the reduction
in proportion, or dilution of the rubber proportion, as process oil
amount is increased. The volume percent of rubber is 82.6 vol
percent, 77.6 vol percent, and 73.2 vol percent, for 0 phr process
oil, 7.5 phr process oil, and 15 phr process oil, respectively.
[0102] Additional properties and characteristics were determined
for golf ball cores 1 and 4 to evaluate golf ball core properties
and characteristics for different fillers. The results were
summarized in Table 4 below. The results illustrated that the
performance properties and characteristics of the two golf ball
cores are quite similar. Although the inventors do not wish to be
bound by theory, it is believed that any differences between the
properties and characteristics of the two golf ball cores is the
result of differences in density and high Mooney viscosity
polybutadiene rubber concentration, i.e., lower density and high
Mooney viscosity polybutadiene rubber concentration lead to lower
COR and softer compression.
TABLE-US-00004 TABLE 4 Comparison of performance properties and
characteristics with different fillers Golf ball core 1 4 Recipe 1
2 Rubber BR1208 BR1208 Theoretical density, g/cm.sup.3 1.1311
1.1264 Observed density, g/cm.sup.3 1.16 1.15 Vol percent Rubber
82.65 82.13 COR 0.7832 0.7794 ADC Compression, mm 3.96 4.12
[0103] Additional examples or golf ball cores are prepared in
accordance with embodiments of the disclosure. The performance
properties and characteristics of each are as described in this
disclosure. Each of the values in Table 5A is weight. Table 5B
expresses amounts of peptizing agent in phr.
TABLE-US-00005 TABLE 5A Additional Examples Golf ball core 1 2 3 4
5 6 7 8 9 10 High Mooney viscosity 98 98 98 93.5 93.5 93.5 98 98 98
98 polybutadiene rubber Aromatic process oil 2 6.5 Naphthenic
process oil 2 6.5 Paraffinic process oil 2 6.5 Epoxidized soybean
oil 1.8 1.8 1.8 2 Amine 0.2 Polyamide 0.2 Isocyanate 0.2 Total 100
100 100 100 100 100 100 100 100 100
TABLE-US-00006 TABLE 5B Including Peptizing Agent Golf ball core 1
2 3 4 5 6 7 8 9 10 Penta- 0.05 0.05 0.05 0.1 0.1 0.1 0.1 0.1 0.1
0.4 chlorothiophenol, phr
[0104] While various embodiments of the invention have been
described, the description is intended to be exemplary, rather than
limiting and it will be apparent to those of ordinary skill in the
art that many more embodiments and implementations are possible
that are within the scope of the invention. Accordingly, the
invention is not to be restricted except in light of the attached
claims and their equivalents. For example, different process oils,
different high Mooney viscosity rubbers, and different proportions
of oil and rubber may be used. Also, various modifications and
changes may be made within the scope of the attached claims.
* * * * *