JPS6172042A - Molding composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a molding composition, in particular a homogeneous molding composition.
A molding composition suitable for the manufacture of a core component of a solid one-piece golf ball, a core for a homogeneous solid three-piece rubber ball or a multi-component golf ball, and golf balls or golf balls obtained therefrom. Regarding core.

BACKGROUND OF THE INVENTION Solid one-piece golf balls consist of a homogeneous molding process of required weight and dimensions.

The molding process includes providing a small indentation on the outermost surface of the ball.

The two-piece golf ball is
It consists of a spherical molded core surrounded by a jacket, with small indentations on the outermost surface of the jacket.

Aside from dimple design, the properties that most influence a golf ball's dynamic performance are hardness and resilience. The hardness of the ball affects the "feel" when you hit the ball and the sound it makes when hitting the ball. Resilience directly determines the speed at which the ball leaves the club and, combined with the dimple pattern, is the primary factor in determining flight distance.

In the current configuration of three-piece golf balls, most of the ball's performance in terms of resilience comes from the core. The highest quality three-piece balls contain a high content of cis-1,4-polybutadiene (-) and a peroxide containing polymerizable metal salt monomers, typically zinc salts of acrylic and methacrylic acids. A hardened rubber composition is used.

The result of many years of "fine-tuning" of such core formulations is that it has superior performance7 to traditional spool configurations, and is almost at the performance limits established by golf's governing bodies to preserve the character of the current game. You can now get a ball with a similar three-piece configuration. That is, a club-leaving velocity of 77.2 m/sec (225 feet/sec) under standard impact conditions is the maximum currently allowed velocity.

Various tests are used to estimate the performance of golf balls or cores, such as for development and production control purposes. In current specifications and requirements, hardness and resilience are measured as follows.

Hardness is measured at a load of 39.69 kg (87 lbs.) for the core and 41.54 kg (91 lbs.) for the ball.
0.00254++tm (0.00254++tm) when a radial load of 0.00254
001 inches).

Resilience is measured as Newton's coefficient of recovery (of Newton's coefficient of recovery) and is calculated from photoelectric measurements of a ball or core flight ball thrown into the air before and after impact. Impact velocity is 5
49 m/sec (180 feet/sec).

(Means for Solving the Problems) The present invention provides an elastic thermoplastic material and (1) an ionizable copolymer of ethylene and α,β-unsaturated carboxylic acid, which is ionized after blend formation, or , (ii) be additionally ionized after blend formation;
an ionic copolymer of ethylene and an α,β-unsaturated carboxylic acid; or (iii) an ionic copolymer of ethylene and an α,β-unsaturated carboxylic acid that is substantially ionized and powdered prior to blend formation. Ionic copolymer (however, powder copolymer (i
ii) has a maximum particle size of 200 microns and the total neutralization degree of said copolymer (it, (ii) or (iii)) is 60
% or more. ) is provided.

In a preferred embodiment of the present invention, the above copolymer (1), (
The total neutralization degree of ii) or (ii) is at least 70%, preferably 80% or more, particularly 90% or more. The preferred particle size of the powder copolymer (iii) is a maximum of 100 microns. It accounts for 85% or more of the copolymer.The mode particle size of copolymer (iii) is suitably 40 microns.

The present invention provides core components for homogeneous, solid, one-piece golf balls, homogeneous, solid, three-piece golf balls and multi-component golf balls made with the molding compositions described in the immediately preceding paragraph. It also provides the following.

In a more preferred embodiment of the present invention, the above copolymer (1
) or (1) The viscosity index (defined below) must be equal to or greater than that of the elastic thermoplastic material just prior to blend formation.

If necessary, the viscosity index of copolymer (1) or (ii) is adjusted to reach the required level, for example by neutralizing a certain proportion of acid groups as explained below.

"Viscosity index" is a value that relates to the melt viscosity of each Zlend component when subjected to temperature and shear rate conditions, such as in an internal mixer used to form the blend.

These conditions can be approximated using a Prabender Plastograph (PL3S) with a cam mixing chamber (type N50H), with a viscosity index of the observed melt torque under the desired temperature and shear rate conditions. It is a reading.

Elastic thermoplastic materials include, for example, polyester Glock copolyamibi, copolyester, ionic rubber, poly(1,
2-polybutadiene) or a block copolymer of styrene/ethylene/butylene/styrene.

Copolymer (+), (ii) or (iii) is, for example, a copolymer of ethylene and methacrylic acid or acrylic acid.

The ionization of the copolymer (1), (ii) or (iii) can be carried out using a suitable cation-supplying material such as a salt of a group 1 to II metal of the periodic table, such as sodium methoxide, zinc oxide, zinc acetate or magnesium acetate. This can be achieved by

The present inventors further discovered that copolymer (1), (ii) or (
1ii) found that by providing the blend with a microstructure in the form of discrete particles dispersed within a matrix of elastic thermoplastic material, the formability of the blend is greatly enhanced.

The invention will be illustrated by the following examples.

Among the examples, Examples 1-6 demonstrate the use of type (it and (ii)) copolymers of the present invention, and Example 7 illustrates the use of type (iiD) copolymers.

Example 1 A three-piece golf ball core was made from a blend of the following materials.

(1) Material A - Ionic copolymer of ethylene and methacrylic acid with about 30 acid groups neutralized with a sodium ion supplying substance;
Available as SURLYN ) 1605 (SURL
YN is a registered trademark) (ii) Material B-7 Polyester Glock Copolyamide I-# (PEBAX is a registered trademark) available from Atochem as PEBAX 3533 Material A35? and Material B651 were melt-mixed in a Brabender internal mixer at 180C until uniform.

A portion of the blend was formed into 1,5" diameter spheres and was tested for compression as well as resilience, or coefficient of recovery.
on, COR) tests were conducted. The obtained results,
With comparative values for control cores molded from materials A and B,
It is shown in Table 1 below.

Table 1 Compression Resilience (COR) Material A (Control) 18 0.657
Material B (control) 112 0.571
Bren)'' (A+B) (35:65) 46 0.
The compression values for the 618 control show that material A gives a very hard core, whereas material B gives a very soft core. However, the blend provides a ball of intermediate compression, which is acceptable as the core of a three-piece golf ball.

Examples 2-5 Three-piece golf ball cores were made from the following materials and using the following procedures.

Material - Copolymer of ethylene and acrylic acid, believed to contain 20 parts by weight of copolymerized acid. EAA433 from Dow Chemical Co.
(PRIMACOR 5980)
(PRIMACOR is a registered trademark) Materials Bo Pax 3533 (as described in Example 1) The formulations shown in Table 2 were prepared using the following procedure. The indicated parts of materials A and B were charged to an internal mixer, heated to 180C and mixed for 2 minutes. Sufficient cation feed material was then added to the melt to neutralize any acid groups within the blend. Mixing was continued until there was no visible evidence of reaction (gas evolution).

A golf ball core molded from this composition had properties as shown in Table 2.

Example 6 The relationship between the melt viscosity and the degree of neutralization of the ethylene/acrylic acid copolymer of Example 2 was determined using Prabender Plastograph 7 (P
L3S) was determined by measuring the melting torque. Twin rotors with a speed ratio of 1:1.5 were used in the mixing chamber to approximate the mixing action of a Banbury type internal mixer. Neutralization was performed by adding zinc acetate or sodium methoxide to the melt.

Melt torque values were observed after reaction completion at a rotor speed of 60 rpm and a final melt temperature of 170 r. Copolyamide R
The melt viscosity of PEBAX 3533 was also measured in the same manner. These measurement results are shown in FIG. 1 as a glass. This graph shows that the copolyamide is Pax (PEBA).
In order to equalize the melting torque when forming blend 9 of X) 3533 and copolymer EAA433 (PRMACOR 5980), approximately 52 of the acid groups of the copolymer were replaced with zinc ions. This indicates the need for neutralization.

Ethylene-acrylic acid copolymer 2200 of Example 2? The mixture was placed in an internal mixer, preheated to about 1200 ℃, and mixed until melted. Zinc acetate dihydrate 404P (sufficient amount to neutralize about 60% of the acid groups) was added to the molten copolymer and mixing continued until there was no evidence of reaction.

During this time, the melting temperature was increased to about 180C. This material was then removed and sheeted on a two roll mill.

Partially neutralized acid copolymer of 1050y- and 144
01 polyether copolyamide (PEBAX) 353
3 into a preheated Banbury type internal mixer,
Operating at 60-75 rpm and 120C rotor speed continued until melting and thorough mixing. The final temperature reached 170C. An additional 1189 ml of zinc acetate dihydrate was then added to the blend to neutralize substantially all remaining acid groups. After mixing was completed, the material was removed and sheeted and granulated. The granulated material was injection molded to a diameter of 39.
37mrttC1,55") and 42.67y+m
A smooth ball of (1,68") was made. This ball was of good quality and the test results were as follows.

Diameter 39.37 shoulder m (1,55″) 42.67 order (
1,68”) Compression 43 46 Resilience 0.666 0.6
60 (COR) Example 7 A set of acids of the present invention was prepared with the following procedure.

The latex dispersion of the ethylene-acrylic acid copolymer of Example 2 was mixed with 100% of the copolymer. , ion exchange water 1010
0O! and ammonia solution (27 NH3) 30 m
(! was prepared by stirring at 95C for 20-30 minutes. After all the solid copolymer was dispersed, the dispersion was cooled to room temperature. Zinc acetate 32? The resulting mixture was filtered and a "wet cake"-like particulate material was recovered which was dried in an oven at 50C and broken into small pieces of 1200 micron particles. The agglomerated material was further divided by passing through an ultracentrifugal mill equipped with a sieve.As examined by micrographs, the particle size of the resulting material ranged from 0-200 microns, with 85 inches less than 100 microns; The mode was 40 microns.

As a result of analyzing this fine particulate material by infrared spectroscopy, it was found that 60% of acid groups
% was neutralized with zinc salts.

This particulate material did not show any melting or signs of melting when sprinkled onto a metal plate heated to 160C.

50P polyether copolyamibi, k pax (P
EBAX) 3533 was charged into a 160 t:l' internal mixer and mixed until melted. Said fine particulate material 5
0I was added and mixing continued until it was completely dispersed in the copolyamide. Next, the composition was taken out from the mixer and compression molded to a diameter of 41.275 mw (1
, 625") spherical molds were used to form golf ball cores. Test results for these cores are as follows.

Compression 48 v-)+)xysu (GOFC) 0.687

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the melt viscosity (melt torque) and the degree of neutralization of the ethylene/acrylic acid copolymer of Example 2. (5 other people) Figure 1

Claims (1)

[Claims] 1) an elastic thermoplastic material; (i) ethylene and α, which are ionized after forming the blend;
, an ionizable copolymer of ethylene and an α,β-unsaturated carboxylic acid, or (ii) an ionic copolymer of ethylene and an α,β-unsaturated carboxylic acid, which is additionally ionized after blend formation; an ionic copolymer of ethylene and α,β-unsaturated carboxylic acid, which is ionized and powdered before blend formation, with the exception that powder copolymer (iii)
said copolymer (i), having a maximum particle size of 00 microns;
A molding composition comprising a blend of (ii) or (iii) with a total neutralization degree of 60% or more. 2) The copolymer is (i) or (ii), and the viscosity index of the copolymer (i) or (ii) is equal to or higher than the viscosity index of the elastic thermoplastic material immediately before blend formation. A composition according to claim 1, characterized in that: 3) The elastic thermoplastic material is polyester block, copolyamide, copolyester, ionic rubber, poly(1,2
3. The composition according to claim 1 or 2, wherein the composition is a styrene/ethylene/butylene/styrene block copolymer. 4) Any one of claims 1 to 3, wherein the copolymer (i), (ii) or (iii) is a copolymer of ethylene and methacrylic acid or acrylic acid. The composition described in. 5) Cation supplying substances such as those from Group I to Periodic Table
The method according to any one of claims 1 to 4, characterized in that the copolymer (i), (ii) or (iii) is ionized or additionally ionized with a group IV metal salt. Composition. 6) Composition according to claim 5, characterized in that the cation-supplying material is sodium methoxide, zinc oxide, zinc acetate or magnesium acetate.