U.S. patent application number 13/313550 was filed with the patent office on 2012-03-29 for golf ball and method of improving golf ball performance.
This patent application is currently assigned to BRIDGESTONE SPORTS CO., LTD.. Invention is credited to Yoshinori EGASHIRA, Takashi OHIRA, Jun SHINDO, Eiji TAKEHANA.
Application Number | 20120077624 13/313550 |
Document ID | / |
Family ID | 41726303 |
Filed Date | 2012-03-29 |
United States Patent
Application |
20120077624 |
Kind Code |
A1 |
EGASHIRA; Yoshinori ; et
al. |
March 29, 2012 |
GOLF BALL AND METHOD OF IMPROVING GOLF BALL PERFORMANCE
Abstract
A golf ball having a polymer layer that has been subjected to
impregnation treatment with an isocyanate and/or
isothiocyanate-containing olefin compound exhibits at least one
improved golf ball attribute, such as scuff resistance or spin
performance, compared with an original golf ball that has not been
treated by impregnation.
Inventors: |
EGASHIRA; Yoshinori;
(Saitama-ken, JP) ; SHINDO; Jun; (Saitama-ken,
JP) ; TAKEHANA; Eiji; (Saitama-ken, JP) ;
OHIRA; Takashi; (Saitama-ken, JP) |
Assignee: |
BRIDGESTONE SPORTS CO.,
LTD.
Tokyo
JP
|
Family ID: |
41726303 |
Appl. No.: |
13/313550 |
Filed: |
December 7, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12199990 |
Aug 28, 2008 |
8106134 |
|
|
13313550 |
|
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|
|
Current U.S.
Class: |
473/378 |
Current CPC
Class: |
C08G 18/4854 20130101;
C08G 18/10 20130101; B29C 35/02 20130101; A63B 37/0095 20130101;
B29L 2031/54 20130101; B29C 35/0805 20130101; C08G 18/10 20130101;
C08G 18/3243 20130101; C08G 18/10 20130101; B29C 2035/0827
20130101; C08G 18/3206 20130101 |
Class at
Publication: |
473/378 |
International
Class: |
A63B 37/12 20060101
A63B037/12 |
Claims
1. A golf ball comprising a core and a cover of a polymer layer,
wherein the cover has been treated by impregnation with an olefin
compound having a group selected from among an isocyanate group, an
isothiocyanate group, an isocyanate group-blocked portion formed
with isocyanate group under the application of heat, and an
isothiocyanate group blocked portion formed with isothiocyanate
group under the application of heat.
2. The golf ball of claim 1, wherein the polymer layer is a
thermoplastic and/or thermoset polymer.
3. The golf ball of claim 1, wherein the isocyanate and/or
isothiocyanate-containing olefin compound in the impregnated
polymer layer is subjected to thermal polymerization,
photopolymerization and/or addition reaction with functional
groups.
4. The golf ball of claim 3, wherein the olefin moiety of the
isocyanate and/or isothiocyanate-containing olefin compound is at
least one olefin group selected from the group consisting of
acrylic, methacrylic, allyl and vinyl groups, and exhibits
photopolymerizability on exposure to ultraviolet light and/or
thermal polymerizability.
5. The golf ball of claim 3, wherein the isocyanate moiety of the
isocyanate-containing olefin compound exhibits addition reactivity
with at least one functional group selected from the group
consisting of amide, urethane, primary amino, secondary amino,
hydroxyl and carboxyl groups.
6. The golf ball of claim 3, wherein the isothiocyanate moiety of
the isothiocyanate-containing olefin compound exhibits addition
reactivity with at least one functional group selected from the
group consisting of amide, urethane, primary amino, secondary
amino, hydroxyl and carboxyl groups.
7. The golf ball of claim 3, wherein the isocyanate and/or
isothiocyanate-containing olefin compound has a melting point of
not above 80.degree. C.
8. The golf ball of claim 1, wherein the impregnated layer formed
by impregnation of the isocyanate and/or isothiocyanate-containing
olefin compound into the polymer layer has a thickness in a range
of from about 5 .mu.m to about 900 .mu.m.
9. The golf ball of claim 1, wherein the impregnated layer formed
by impregnating the polymer layer with the isocyanate and/or
isothiocyanate-containing olefin compound has a surface hardness
which is from about 1 to about 10 Shore D hardness units higher
than the surface hardness of the polymer layer prior to the
impregnation treatment.
10. The golf ball of claim 1 which is selected from the group
consisting of two-piece solid golf balls composed of a core and a
cover encasing the core, and multi-piece solid golf balls composed
of a core of at least one layer, one or more intermediate layers
encasing the core, and a cover of at least one layer encasing the
intermediate layer.
11. The golf ball of claim 1, wherein an isocyanate and/or
isothiocyanate-containing olefin compound is selected from among
2-iso(thio)cyanatoethyl methacrylate, 2-iso(thio)cyanatoethyl
acrylate, 3-iso(thio)cyanatopropyl acrylate,
1-methyl-2-iso(thio)cyanatoethyl methacrylate,
1,1-dimethyl-2-iso(thio)cyanatoethyl acrylate,
allyliso(thio)cyanate, allylthiocyanate,
methylvinyliso(thio)cyanate, vinyliso(thio)cyanate,
vinylthiocyanate, bis-(2-iso(thio)cyanatoethyl)fumarate,
2-iso(thio)cyanato-2-methylpropylene glycol diacrylate and
2-(2-iso(thio)cyanatoethoxy)ethyl (meth)acrylate.
12. The golf ball of claim 1, wherein the olefin compound having an
isocyanate group-blocked portion and/or an isothiocyanate group
blocked portion is selected from among
2-[O-(1-methylpropylidenamino)carboxyamino]ethyl (meth) acrylate,
2-(pyrazoyl-1-carbonylamino)ethyl (meth)acrylate and
tris(2-acryloyloxyethyl)isocyanurate.
13. The golf ball of claim 1, wherein the content of the isocyanate
and/or isothiocyanate-containing olefin compound impregnated into
the golf ball is from about 0.01 g to about 7.00 g.
14. The golf ball of claim 1, wherein the polymer material of the
polymer layer is selected from the group consisting of polyolefin
elastomers, ethylene ionomers, polyolefins, metallocene
polyolefins, polystyrene elastomers, diene polymers, polyacrylate
polymers, polyamide elastomers, polyurethane elastomers, polyester
elastomers, polyacetals, thermoset urethanes and silicone
polymers.
15. The golf ball of claim 1, wherein the cover has not been
top-coated.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. application Ser.
No. 12/199,990, filed Aug. 28, 2008 (now allowed); the entire
disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a golf ball of improved
performance which includes, in a polymer layer making up the golf
ball, a layer that has been treated by impregnation with an
isocyanate group (here and below, "isocyanate group" encompasses
also "isothiocyanate group")-containing olefin compound.
[0003] Organic reactive compounds are useful materials in golf
balls made with thermoplastic and thermoset polymer materials. Of
such compounds, isocyanate group-containing compounds in
particular, when blended with a polymer material, are able to
modify the properties of the polymer material, and have thus been
useful compounds as golf ball modifiers.
[0004] Organic reactive compounds are commonly included in polymer
materials for golf balls for a variety of purposes. For example,
organic peroxides such as dicumyl peroxide and di-t-butylperoxide,
epoxy compounds such as bisphenol A diglycidyl ether and
polyethylene glycol diglycidyl ether, and acrylate compounds such
as 1,4-butanediol diacrylate and triethylene glycol diacrylate are
used for crosslinking between polymer molecules. Various compounds,
including acid anhydrides such as maleic anhydride and itaconic
anhydride, silane compounds such as silsesquioxane oligomer and
POSS, and isocyanate compounds such as toluene diisocyanate and
4,4'-diphenylmethane diisocyanate, are used in the presence of a
peroxide for the purpose of introducing functional groups onto
polymer molecules. Numerous patent applications have been filed
concerning the use of such compounds.
[0005] Examples include the following, all for the purpose of
crosslinking between polymer molecules: Patent Document 1 (U.S.
Pat. No. 7,387,821) and Patent Document 2 (U.S. Pat. No. 7,387,582)
relating to the use of an organic peroxide, Patent Document 3 (U.S.
Pat. No. 5,908,358) and Patent Document 4 (U.S. Pat. No. 7,358,310)
relating to the use of an epoxy compound, Patent Document 5 (U.S.
Pat. No. 7,151,148) and Patent Document 6 (U.S. Pat. No. 7,001,286)
relating to the use of an acrylate compound, Patent Document (U.S.
Pat. No. 6,890,661) and Patent Document 8 (U.S. Pat. No. 7,029,405)
relating to the use of an acid anhydride, Patent Document 9 (U.S.
Pat. No. 6,585,607) and Patent Document 10 (U.S. Pat. No.
6,919,395) relating to the use of a silane compound, and Patent
Document 11 (JP-A 11-178949) and Patent Document 12 (JP-A
2008-049152) relating to the use of an isocyanate compound.
[0006] As noted above, almost all conventional methods for using
organic reactive compounds in the field of golf balls involve
blending those compounds with various polymer materials at some
stage prior to molding golf balls, thereby modifying the functions
of the polymer materials and causing such changes to be reflected
in the performance of the molded golf balls.
[0007] Yet, a desire has arisen recently for even further
improvement in the performance of molded golf balls, such as the
feel of the ball on impact, scuff resistance, spin and distance. It
is customary to conduct studies on improvements in golf ball
performances by reexamining the various polymer materials making up
the balls. By contrast, with the exception of certain patents
relating to partial surface modification (Patent Document 13: U.S.
Pat. No. 6,458,307; Patent Document 14: U.S. Pat. No. 7,381,776),
very few of any specific measures targeted at molded golf balls or
golf balls in the process of being molded have been employed to
date. Hence, this remains an area of untapped potential.
[0008] Patent Document 1: U.S. Pat. No. 7,387,821
[0009] Patent Document 2: U.S. Pat. No. 7,387,582
[0010] Patent Document 3: U.S. Pat. No. 5,908,358
[0011] Patent Document 4: U.S. Pat. No. 7,358,310
[0012] Patent Document 5: U.S. Pat. No. 7,151,148
[0013] Patent Document 6: U.S. Pat. No. 7,001,286
[0014] Patent Document 7: U.S. Pat. No. 6,890,661
[0015] Patent Document 8: U.S. Pat. No. 7,029,405
[0016] Patent Document 9: U.S. Pat. No. 6,585,607
[0017] Patent Document 10: U.S. Pat. No. 6,919,395
[0018] Patent Document 11: JP-A 11-178949
[0019] Patent Document 12: JP-A 2008-049152
[0020] Patent Document 13: U.S. Pat. No. 6,458,307
[0021] Patent Document 14: U.S. Pat. No. 7,381,776
SUMMARY OF THE INVENTION
[0022] It is therefore an object of the present invention to
provide a golf ball in which, by using the above-mentioned organic
reactive compound to carry out impregnation treatment on a polymer
layer making up the golf ball, and in particular a polymer material
making up the surface layer of the ball, performance attributes
such as scuff resistance and spin have been improved without
breaking the golf ball.
[0023] The inventors have, in studying the various organic reactive
compounds included in golf balls, taken an approach not seen in
prior golf ball applications. That is, instead of conducting a
study which reexamines the various polymer materials making up the
golf ball, the inventors have extensively studied different
reactive compounds with the object of improving the performance of
the molded golf ball itself. As a result, the inventors have found
out that isocyanate group-containing olefin compounds are ideal
materials for achieving this object.
[0024] Moreover, the inventors have learned from further studies
that golf balls which include as a component thereof (here and
below, the cover material in a two-piece solid golf ball composed
of a core and a cover encasing the core, or the cover material or
intermediate layer material in a multi-piece solid golf ball
composed of a core of one or more layer, one or more intermediate
layer encasing the core, and a cover of one or more layer encasing
the intermediate layer) a molded polymer layer that has been by the
impregnation treatment with the above-mentioned isocyanate
group-containing olefin compound have improved performances and
thus excellent properties.
[0025] Accordingly, the present invention provides the following
golf ball and the method of improving golf ball performances.
[0026] [I] A golf ball that includes a polymer layer which has been
by the impregnation treatment with an isocyanate and/or
isothiocyanate-containing olefin compound. [0027] [II] A method of
modifying a golf ball having a polymer layer, which includes the
step of impregnating the polymer layer with an isocyanate and/or
isothiocyanate-containing olefin compound.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The invention is described more fully below.
[0029] The present invention provides a golf ball that includes a
polymer layer which has been by the impregnation treatment with an
isocyanate and/or isothiocyanate-containing olefin compound. In the
following description, for the sake of convenience, the isocyanate
and/or isothiocyanate-containing olefin compound is referred to
simply as the "isocyanate-containing olefin compound."
[0030] Also, as used herein, "impregnation treatment" additionally
includes, following the impregnation with the organic reactive
compound, heat treatment and/or ultraviolet light (UV) irradiation
treatments and a period of time elapsed.
[0031] The inventors have conducted studies to determine whether,
by subjecting the polymer layer of a molded golf ball to the
impregnation treatment with an isocyanate group-containing olefin
compound, it is possible to improve the performances of the golf
ball ultimately obtained.
[0032] However, the large number of organic reactive compounds,
such as crosslinking agents, which could be used for the
impregnation treatment of the thermoplastic and/or thermoset
polymer materials in the polymer layer of the golf ball made it
impossible to comprehensively examine all such compounds in the
studies conducted for this invention.
[0033] Therefore, selection of the organic reactive compound was
carried out first from a number of initial "decision factors" that
include, for example: [0034] (1) compounds which, because of
carrying out the impregnation treatment, are liquid, if not
necessarily at room temperature, conveniently at near room
temperature; [0035] (2) compounds which have two or more reactive
groups per molecule (i.e., compounds which have a crosslinking
action); [0036] (3) compounds which can be reacted under the
influence of heat and/or ultraviolet light; and [0037] (4)
compounds which are, in themselves, homopolymerizable.
[0038] In addition, the impregnation treatment was carried out on
the polymer layer of the golf ball, and the physical properties of
the golf ball ultimately obtained, including changes over time,
were evaluated.
[0039] As a result, the inventors found out that
isocyanate-containing olefin compounds are preferred as organic
reactive compounds which have the effect of improving the
performances (e.g., feel on impact, scuff resistance, spin,
distance) of the golf ball ultimately obtained following the
impregnation treatment of the thermoset and/or thermoplastic
polymer materials making up the polymer layer of a golf ball, and
ultimately arrived at the present invention.
[0040] The isocyanate-containing olefin compounds of the invention
have been found from the studies to have the following
characteristics: [0041] (1) the isocyanate group exhibits addition
reactivity with amide groups (--NHCO--), urethane groups
(--NHCOO--), primary and secondary amino groups (--NH.sub.2-- and
--NH--R, where R is alkyl, aralkyl, allyl, aryl, etc.), hydroxyl
groups (--OH) and carboxyl groups (--COOH); [0042] (2) the olefin
group (unsaturated bond) such as the acrylic group
(CH.sub.2.dbd.CHCO--), methacrylic group
(CH.sub.2.dbd.C(CH.sub.3)CO--), allyl group (CH.sub.2.dbd.CHCH--)
and vinyl group (CH.sub.2.dbd.CH--) exhibits photocrosslinkability
by exposure to ultraviolet light and/or thermal crosslinkability by
heat treatment; [0043] (3) the compound exhibits
homopolymerizability or copolymerizability (with regard to
homopolymerizability and copolymerizability, see Journal of Polymer
Science Part A: Polymer Chemistry 44 (16), 4762-4768 (2006));
[0044] (4) the compound has a good compatibility with urethane
materials (including both thermoset and thermoplastic materials),
polyester and/or polyether materials and amide materials, and shows
a tendency to be easily impregnated therein; [0045] (5) the
compound has a poor compatibility with polyethylene materials
(including polyethylene, metallocene polyethylene, ethylene-based
acid copolymers and ethylene-based ionomers), styrene elastomer
materials and diene materials (e.g., BR, NBR, CR), and shows a
tendency to be difficult to impregnate therein; and [0046] (6) the
compound is liquid at ordinary temperatures (20.degree.
C..+-.15.degree. C.).
[0047] Specific examples of the isocyanate-containing olefin
compound used in the present invention include, but are not limited
to, 2-iso(thio)cyanatoethyl methacrylate, 2-iso(thio)cyanatoethyl
acrylate, 3-iso(thio)cyanatopropyl acrylate,
1-methyl-2-iso(thio)cyanatoethyl methacrylate,
1,1-dimethyl-2-iso(thio)cyanatoethyl acrylate,
allyliso(thio)cyanate, allylthiocyanate,
methylvinyliso(thio)cyanate, vinyliso(thio)cyanate,
vinylthiocyanate, bis-(2-iso(thio)cyanatoethyl)fumarate,
2-iso(thio)cyanato-2-methylpropylene glycol diacrylate and
2-(2-iso(thio)cyanatoethoxy)ethyl (meth)acrylate. In addition,
illustrative examples of isocyanate group-blocked derivatives
formed with isocyanate groups under the application of heat include
2-[O-(1-methylpropylidenamino)-carboxyamino]ethyl(meth)acrylate,
2-(pyrazoyl-1-carbonylamino)ethyl(meth)acrylate and
tris(2-acryloyloxyethyl)isocyanurate.
[0048] Of the group of above-mentioned isocyanate-containing olefin
compounds, from the standpoint of commercial production,
2-isocyanatoethyl methacrylate, 2-isocyanatoethyl acrylate,
3-isocyanatopropyl acrylate and 2-isocyanato-2-methylpropylene
glycol diacrylate are preferred. Taking polymerizability into
account, 2-isocyanatoethyl acrylate and
2-isocyanato-2-methylpropylene glycol diacrylate are more
preferred.
[0049] The above isocyanate-containing olefin compound has a
melting point of preferably 80.degree. C. or below, more preferably
60.degree. C. or below, and even more preferably 35.degree. C. or
below. Isocyanate-containing olefin compounds which are liquid at
temperatures near 0 to 35.degree. C. are suitable for the
impregnation treatment.
[0050] The following conditions (1) to (5) apply to the
impregnation treatment of golf balls with the isocyanate-containing
olefin compound of the present invention. [0051] (1) The
impregnation temperature is preferably as high as possible within a
range up to the melting point of the polymer material making up the
polymer layer of the golf ball to be impregnated. However, care
must be taken with the homopolymerization of the
isocyanate-containing olefin compound. It is desirable for the
impregnation temperature to be within a range of from about
0.degree. C. to about 100.degree. C., preferably from about
5.degree. C. to about 80.degree. C., and more preferably from about
10.degree. C. to about 50.degree. C. [0052] (2) The impregnation
time, which depends on both the type of polymer material making up
the polymer layer in the golf ball to be impregnated and the
impregnation temperature, is preferably within a range of from
about 15 seconds to about 100 hours, more preferably from about 1
minute to about 80 hours, and even more preferably from about 30
minutes to about 50 hours. [0053] (3) Following the impregnation,
it is essential to either wipe off, or blow off with an air knife,
surplus isocyanate-containing olefin compound adhering to the
surface layer of the golf ball. If the isocyanate-containing olefin
compound is left adhering to the surface layer of the golf ball,
the isocyanate-containing olefin compound homopolymerizes, forming
irregularities (a thin, uneven layer) on the surface of the golf
ball, which adversely affects the properties of the golf ball.
[0054] (4) Carrying out UV irradiation treatment
(photocrosslinking) and/or heat treatment (thermal crosslinking)
following the impregnation improves the performance of the golf
ball. In such a case, the UV irradiation time when using a
high-pressure mercury vapor lamp is in a range of from about 5
seconds to about 50 hours, preferably from about 20 seconds to
about 25 hours, and more preferably from about 30 seconds to about
10 hours. The irradiation temperature is in a range of from about
0.degree. C. to about 100.degree. C., preferably from about
5.degree. C. to about 80.degree. C., and more preferably from about
10.degree. C. to about 50.degree. C. A higher temperature tends to
be better, so long as the temperature is at or below the melting
point of the polymer material making up the polymer layer of the
golf ball to be impregnated. The heat treatment (thermal
crosslinking) temperature is in a range of from about 25.degree. C.
to about 100.degree. C., preferably from about 35.degree. C. to
about 80.degree. C., and more preferably from about 40.degree. C.
to about 60.degree. C. A higher temperature tends to be better, so
long as the temperature is at or below the melting point or
softening point of the polymer material making up the polymer layer
of the golf ball to be impregnated. [0055] (5) Alternatively, the
advantageous effects of the invention can be achieved by allowing
the golf ball to keep standing without subjecting the ball to the
UV irradiation treatment or heat treatment following impregnation.
In such a case, a long period of time elapsed of at least about 200
hours is required. For example, it may be necessary to allow the
golf ball to keep standing in this way for 30 days (720 hours).
[0056] The impregnated layer obtained by the impregnation treatment
of the polymer layer of the golf ball with the
isocyanate-containing olefin compound of the invention has a
thickness, as calculated from the difference in the weight of the
golf ball before and after impregnation treatment and the
difference in the outermost diameter of the golf ball before and
after the impregnation treatment, in a range of preferably from
about 5 .mu.m to about 900 .mu.m. The content of the
isocyanate-containing olefin compound impregnated into the golf
ball is preferably from about 0.01 g to about 7.00 g, and more
preferably from about 0.05 g to about 5.00 g.
[0057] The difference in hardness, before and after treatment, of
the polymer layer obtained by the impregnation treatment of the
golf ball with the isocyanate-containing olefin compound in the
present invention is dependent on the polymer material making up
the impregnated layer of the golf ball, although an increase within
a range of from about 1 to about 10 Shore D hardness units is
preferred.
[0058] No particular limitation is imposed on the polymer material
in the polymer layer of the golf ball on which the impregnation
treatment with the isocyanate-containing olefin compound of the
invention is to be carried out, provided it is a thermoplastic
polymer and/or thermoset polymer commonly used in golf balls.
Illustrative examples of thermoplastic polymers include polyolefin
elastomers (including ethylene ionomers, polyolefins and
metallocene polyolefins), polystyrene elastomers, diene polymers,
polyacrylate polymers, polyamide elastomers, polyurethane
elastomers, polyester elastomers and polyacetals. Illustrative
examples of thermoset polymers include thermoset urethanes and
silicone polymers.
[0059] In the impregnation treatment of the golf ball with the
isocyanate-containing olefin compound of the invention, to promote
photocrosslinking by UV irradiation treatment or thermal
crosslinking by heat treatment of the impregnated
isocyanate-containing olefin compound, optional additives can also
be suitably included with the isocyanate-containing olefin compound
according to the intended application. For example, a
photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone,
2-hydroxy-2-methyl-1-phenyl propan-1-one,
2,2-dimethoxy-1,2-diphenylethan-1-one) or a thermal polymerization
initiator (diisobutyryl peroxide, diisopropyl peroxydicarbonate,
dibenzoyl peroxide) can be added. When these additives are
included, the amount of such addition, per 100 parts by weight of
the isocyanate-containing olefin compound, is preferably at least
0.1 part by weight, and more preferably at least 0.5 part by
weight, but preferably not more than 10 parts by weight, and more
preferably not more than 7 parts by weight.
[0060] The golf ball used in the present invention is a one-piece
solid golf ball, a two-piece solid golf ball composed of a core and
a cover encasing the core, or a multi-piece solid golf ball
composed of a core of at least one layer, one or more intermediate
layers encasing the core, and a cover of at least one layer
encasing the intermediate layer. Impregnation treatment of a molded
golf ball layer can be carried out in any manufacturing step. In
cases where the outermost layer of a commercial golf ball is
treated by the impregnation, it is preferable to carry out the
impregnation treatment of the golf ball after the surface has been
trimmed prior to the final step of topcoating in the manufacturing
process.
[0061] The weight of the golf ball following the impregnation
treatment with the isocyanate-containing olefin compound of the
invention is preferably in a range of from about 44.80 g to about
45.60 g.
[0062] The outside diameter of the golf ball following the
impregnation treatment with the isocyanate-containing olefin
compound of the invention is preferably in a range of from about
42.65 mm to about 42.75 mm.
EXAMPLES
[0063] The following examples of the invention are provided by way
of illustration and not by way of limitation.
Example 1
[0064] The following impregnation treatment was carried out using
the golf balls A (which refers to the same symbol A in the table;
the same applies below) with a spherically trimmed ionomer cover
layer which has not been topcoated (surfacemost layer coating) in
Table 1 and using 2-isocyanatoethyl acrylate as the
isocyanate-containing olefin compound.
[0065] Five Golf Ball As were placed in a 500 ml beaker containing
about 250 ml of 2-isocyanatoethyl acrylate, continuously the beaker
was placed in an aluminum pouch with fastener and sealed, and the
golf balls were kept stationary at 23.degree. C. for 10 hours and
thereby impregnated. The impregnated Golf Ball As were then removed
from the beaker, of which the surfaces were wiped off, and UV
irradiation was carried out for one hour at 40.degree. C. with a
high-pressure mercury vapor lamp (H40 paint fadeometer, same model
as old FM-1, manufactured by Suga Test Instruments Co., Ltd.). The
impregnated Golf Ball As were left standing for one day at
23.degree. C., and the surface hardness of the cover layers was
measured. In addition, topcoating was carried out, thereby
finishing the balls as conventional golf ball products. The
physical properties of these golf balls were measured one week
later, yielding the results shown in Table 1. All the impregnation
treatments prior to UV irradiation were carried out within a draft
chamber.
[0066] Compared with the golf balls of Comparative Example 1 which
were not treated by impregnation, the golf balls of Example 1 which
were treated by impregnation with 2-isocyanatoethyl acrylate showed
an increase of from 65 to 67 in hardness (Shore D) of the ionomer
cover layer's surface, and showed a certain increase in the initial
velocity and total distance when the golf balls were hit with a
number one wood at a head speed of 46 m/sec. Moreover, the back
spin exhibited a desirable decreasing tendency. The golf balls also
had an improved scuff resistance.
Examples 2 and 3
[0067] Aside from changing the impregnation time of the Golf Ball A
in 2-isocyantoethyl acrylate in Example 1 from 10 hours to 15 hours
and 25 hours, respectively, the same procedures were carried out as
in Example 1, thereby obtaining each impregnated Golf Ball As of
Examples 2 and 3 in the invention. The properties of these golf
balls were measured. Those results were shown in Table 1. As in
Example 1, compared with Comparative Example 1, the surface
hardness (Shore D) of the ionomer cover layer of the two
furthermore rose from 65 to 69 and 70, respectively, the initial
velocity and total distance of both of the two increased, and their
back spins exhibited a desirable decreasing tendency. The golf
balls also had an improved scuff resistance.
Example 4
[0068] Aside from using the Golf Ball Bs having a urethane/ionomer
cover layer instead of the Golf Ball As having an ionomer cover
layer used in Example 1, the same procedures were carried out as in
Example 1 to give the impregnated Golf Ball Bs of Example 4. The
properties of these golf balls were measured. Those results were
shown in Table 1. Compared with Comparative Example 2, wherein the
impregnation treatment was not carried out, the surface hardness
(Shore D) of the urethane/ionomer cover layers increased from 52 to
55, and improvements occurred in the initial velocity, total
distance and scuff resistance.
Examples 5 and 6
[0069] Aside from using the Golf Ball Cs having a thermoplastic
urethane cover layer instead of the Golf Ball
[0070] As having an ionomer cover layer used in Example 1, and
aside from changing the impregnation time of the Golf Ball C in
2-isocyanatoethyl acrylate from 10 hours to 5 hours and 25 hours,
respectively, the same procedures were carried out as in Example 1,
thereby giving the impregnated Golf Ball Cs in Examples 5 and 6.
The properties of these golf balls were measured. Those results
were shown in Table 1. Compared with Comparative Example 3, in
which the golf balls were not treated by impregnation, the surface
hardness (Shore D) of the thermoplastic urethane cover layers rose
from 57 to 60 and 64, respectively. Those initial velocity, total
distance and scuff resistance also increased.
Example 7
[0071] Aside from using the Golf ball Ds having a thermoset
urethane cover layer instead of the Golf Ball Cs having a
thermoplastic urethane cover layer used in Example 6, and aside
from using 2-isocyanatoethyl methacrylate containing a 3.5 wt %
photocatalyst Irgacure 184 (available from Ciba-Geigy) instead of
2-isocyanatoethyl acrylate, with changing both the impregnation
time from 25 hours to 10 hours and the UV irradiation time from 1
hour to 0.5 hour, the same procedures were carried out as in
Example 6, thereby giving the impregnated Golf Ball Ds in Example
7. The properties of these golf balls were measured. Those results
were shown in Table 1. Compared with Comparative Example 4, in
which the golf balls were not treated by impregnation, the surface
hardness (Shore D) of the thermoset urethane cover layers rose from
54 to 58. Those initial velocity, total distance and scuff
resistance also increased.
Example 8
[0072] Aside from using the Golf Ball Es having a polyoxymethylene
ionomer cover layer instead of the Golf Ball Ds having a thermoset
urethane cover layer used in Example 7, the same procedures were
carried out as in Example 7, thereby giving the impregnated Golf
Ball Es in Example 8. The properties of these golf balls were
measured. Those results are shown in Table 1. Compared with
Comparative Example 5, in which the golf balls were not treated by
impregnation, the surface hardness (Shore D) of the
polyoxymethylene ionomer cover layers rose from 64 to 67. Those
initial velocity, total distance and scuff resistance also
increased.
Example 9
[0073] Aside from using the one-piece Golf Ball Fs having a
polybutadiene layer instead of the Golf Ball Ds having a thermoset
urethane cover layer used in Example 7, the same procedures were
carried out as in Example 7, thereby giving the impregnated
one-piece Golf Ball Fs of Example 9. The properties of these golf
balls were measured. Those results were shown in Table 1. Compared
with Comparative Example 6, in which the golf balls were not
treated by impregnation, the surface hardness (Shore D) of the
polybutadiene layers rose from 51 to 54. Those initial velocity,
total distance and scuff resistance also increased.
Comparative Example 1
[0074] For the purpose of comparison with Examples 1 to 3 of the
invention, the Golf Ball As having the ionomer cover layer used in
Examples 1 to 3 were not subjected to impregnation treatment with
2-isocyanoethyl acrylate, although the procedures following UV
irradiation in Example 1 were carried out, thereby giving the Golf
Ball As having an ionomer cover layer in Comparative Example 1. The
properties of these golf balls were measured, and those results
were shown in Table 2.
[0075] Compared with Examples 1 to 3, the surface hardness was low
and the ball properties were inferior.
[0076] Also, on comparing the properties of the Golf Ball As having
a UV-irradiated ionomer cover layer obtained in Comparative Example
1 and the Golf Ball As having an original ionomer cover layer that
was not UV irradiated, no substantial difference between the two
was observed, indicating that UV irradiation did not affect the
ball properties.
Comparative Examples 2 to 6
[0077] Comparative Examples 2 to 6 correspond respectively to, and
serve as controls for, Examples 4 to 9. In these comparative
examples, golf balls were obtained by carrying out the same
procedures as in Comparative Example 1; that is, without carrying
out the impregnation treatment, using 2-isocyanatoethyl acrylate or
2-isocyanatoethyl methacrylate, of the golf balls having a polymer
material cover layer used in the respective examples of the
invention. The properties of these golf balls were measured. Those
results were shown in Table 2. The UV irradiation time was one hour
in Comparative Examples 2 and 3, and was 0.5 hour in Comparative
Examples 4 to 6.
[0078] The golf balls in the respective comparative examples had
lower surface hardnesses and inferior ball properties when compared
with the golf balls obtained in the corresponding examples of the
invention.
[0079] In addition, on comparing the properties of the
UV-irradiated golf balls from Comparative Examples 2 to 6 with the
properties of the respective original and non-UV irradiated golf
balls, no differences therebetween were observed.
TABLE-US-00001 TABLE 1 Example 1 2 3 4 5 6 7 8 9 F) BR--One-piece
GB F E) POM Ionomer-covered GB E D) Thermosetting PU-covered GB D
C) Thermoplastic PU-covered GB C C B) Thermoplastic PU/Ionomer- B
covered GB A) Ionomer-covered GB A A A Isocyanate compound
2-Isocyanatoethyl acrylate 2-Isocyanatoethyl methacrylate*
Impregnation time (h) 10 15 25 10 5 25 10 10 10 Cover surface
hardness of 67 69 70 55 60 64 58 67 54 impregnated layer (Shore D)
Ball diameter (mm) 42.69 42.73 42.75 42.75 42.68 42.74 42.72 42.74
42.71 Ball weight (g) 45.38 45.46 45.55 45.56 45.27 45.54 45.51
45.59 45.62 Deflection (mm) 3.22 3.20 3.19 3.08 2.59 2.61 2.91 2.77
2.81 Scuff resistance 3 2 1 2 2 1 1 2 1 Initial velocity (m/sec)
63.7 64.0 64.1 64.3 63.7 65.1 64.9 65.1 64.3 Back spin (rpm) 3270
3210 3140 3110 3220 2830 2610 2760 3480 Carry (m) 204 204 205 203
203 203 208 213 207 Total distance (m) 223 224 225 221 221 223 227
222 220 *2-Isocyanatoethyl methacrylate includes a 3.5 wt %
1-hydroxycyclohexyl phenyl ketone (Irgacure 184)
TABLE-US-00002 TABLE 2 Comparative Example 1 2 3 4 5 6 F)
BR--One-piece GB F E) POM Ionomer-covered GB E D) Thermosetting
PU-covered GB D C) Thermoplastic PU-covered GB C B) Thermoplastic
PU/Ionomer- B covered GB A) Ionomer-covered GB A Cover surface
hardness of 65 52 57 54 64 51 impregnated layer (Shore D) Ball
diameter (mm) 42.66 42.75 42.64 42.67 42.70 42.67 Ball weight (g)
45.32 45.56 45.16 45.33 45.51 45.58 Deflection (mm) 3.23 3.08 2.57
2.89 2.73 2.81 Scuff resistance 3 3 3 2 3 2 Initial velocity
(m/sec) 63.5 64.0 63.6 64.7 64.8 64.0 Back spin (rpm) 3300 3210
3270 2730 2880 3650 Carry (m) 203 202 203 207 211 206 Total
distance (m) 221 219 220 225 220 218 *2-Isocyanatoethyl
methacrylate includes a 3.5 wt % 1-hydroxycyclohexyl phenyl ketone
(Irgacure 184)
[0080] Details on the materials and methods of measurement in above
Tables 1 and 2 are given below.
[0081] The core mentioned above (crosslinked BR body) was produced
from the following composition.
TABLE-US-00003 1,4-cis-Polybutadiene rubber 100 parts by weight
Zinc acrylate 21 parts by weight Zinc oxide 5 parts by weight
Barium sulfate 26 parts by weight Dicumyl peroxide 0.8 part by
weight
A) Ionomer-Covered GB (3-Piece Golf Ball)
[0082] Ionomer cover blend composition: [0083]
S8940/(S9945+S9910)/titanium oxide/blue pigment=50/50/3/0.02 parts
by weight [0084] S8940, 59945, 59910 (ionomers produced by DuPont)
[0085] Titanium oxide (Tipaque 740, produced by Ishihara Sangyo
Kaisha, Ltd.) [0086] Blue pigment (Pigment Blue 29, produced by
Toyo Ink Mfg. Co., Ltd.)
B) Thermoplastic PU/Ionomer-Covered GB (2-Piece Golf Ball)
[0087] Thermoplastic urethane/ionomer cover blend composition:
[0088] Thermoplastic urethane/Mg-ionomer/titanium oxide/blue
pigment=20/80/3/0.02 parts by weight [0089] Thermoplastic urethane
(aliphatic urethane, produced by DIC Bayer Polymer Ltd.) [0090]
Mg-Ionomer (Bridgestone Sports BSP experimental product) [0091]
Titanium oxide (Tipaque PF740, produced by Ishihara Sangyo Kaisha,
Ltd.) [0092] Blue pigment (Pigment Blue 29, produced by Toyo Ink
Mfg. Co., Ltd.)
[0093] C) Thermoplastic PU-Covered GB (2-Piece Golf Ball)
[0094] Thermoplastic urethane cover blend composition: [0095]
Aliphatic urethane/titanium oxide/blue pigment=100/3/0.02 parts by
weight [0096] Aliphatic urethane (DIC Bayer Polymer Ltd.) [0097]
Titanium oxide (Tipaque PF740, produced by Ishihara Sangyo Kaisha,
Ltd.) [0098] Blue pigment (Pigment Blue 29, produced by Toyo Ink
Mfg. Co., Ltd.)
[0099] D) Thermosetting PU-Covered GB (2-Piece Golf Ball)
[0100] Thermoset urethane cover blend composition: [0101] PTMG
(polytetramethylene ether glycol)--MDI (diphenylmethane
diisocyanate) urethane prepolymer (NCO, 7.5 wt
%)/4,4'-methylenebis-(2,6-diethyl)aniline/N,N'-dimethylamino-diphenylmeth-
ane/trimethylolpropane/titanium oxide/blue
pigment=100/50/50/3/3/0.02 parts by weight [0102] PTMG-MDI urethane
prepolymer (an aromatic urethane produced by DIC Bayer Polymer
Ltd.) [0103] 4,4'-Methylenebis-(2,6-diethyl)aniline (Junsei
Chemical Co.) [0104] N,N'-Dimethylamino-diphenylmethane (Junsei
Chemical Co.) [0105] Trimethylolpropane (Mitsubishi Gas Chemical
Co., Ltd.) [0106] Titanium oxide (Tipaque PF740, produced by
Ishihara Sangyo Kaisha, Ltd.) [0107] Blue pigment (Pigment Blue 29,
produced by Toyo Ink Mfg. Co., Ltd.)
[0108] E) POM/Ionomer-covered GB (2-piece golf ball)
[0109] Polyoxymethylene/ionomer blend composition: [0110]
Polyoxymethylene/Na-ionomer/Zn-ionomer/titanium oxide/blue
pigment=5/50/45/3/0.02 parts by weight [0111] Polyoxymethylene
(AMILAS 5761, produced by Toray Industries, Inc.) [0112] Na-Ionomer
(S8940, produced by DuPont) [0113] Zn-Ionomer (S9910, produced by
DuPont) [0114] Titanium oxide (Tipaque PF740, produced by Ishihara
Sangyo Kaisha, Ltd.) [0115] Blue pigment (Pigment Blue 29, produced
by Toyo Ink Mfg. Co., Ltd.)
[0116] F) BR One-piece GB
[0117] Polybutadiene blend composition: [0118] Polybutadiene/zinc
acrylate/zinc oxide/barium sulfate/peroxide=100/20/5/15/0.8 parts
by weight [0119] Polybutadiene (BR01, produced by JSR Corporation)
Zinc acrylate (Nippon Shokubai Co., Ltd.) [0120] Zinc oxide (Sakai
Chemical Industry Co., Ltd.; average particle size, 0.5 .mu.m)
[0121] Barium sulfate (Sakai Chemical Industry Co., Ltd.; average
particle size, 0.1 .mu.m) [0122] Peroxide (NOF Corporation; dicumyl
peroxide)
Deflection
[0123] The golf ball was placed between two steel plates, and the
deflection (mm) by the ball when compressed under a final load of
1,275 N (130 kgf) from an initial load of 98 N (10 kgf) was
measured. This test was carried out at 23.+-.1.degree. C.
Scuff Resistance
[0124] The golf balls were held at a temperature of 23.+-.1.degree.
C. and hit at a head speed of 33 m/s using a pitching wedge mounted
on a swing robot machine, after which damage from the impact was
visually rated according to the following scale.
[0125] Best: 1 point
[0126] Better: 2 points
[0127] Good (ordinary): 3 points
[0128] Poor: 4 points
[0129] Poorer: 5 points
[0130] Poorest: 6 points
Initial Velocity, Back Spin, Carry and Total Distance
[0131] A golf ball was hit at a head speed of 46 m/sec with a
number one wood using a swing machine, and the initial velocity,
carry, total distance and back spin of the ball following impact
were measured.
* * * * *