JP2017008201A - Ionomer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating material for golf ball capable of being manufactured in a good working environment satisfying requirement by a user who puts priority on flying distance.SOLUTION: There is provided an ionomer composition containing (A) an ionomer of an ethylene unsaturated carboxylic acid copolymer having the content of total of a constitutional unit derived from unsaturated carboxylic acid of over 5.4 mol% and (B) an amine compound containing two or more amino groups in a molecule with an amount of 0.01 to 1 equivalent based on a carboxyl group of the ionomer (A) and having the boiling point at ordinary pressure of 250°C or more.SELECTED DRAWING: None

Description

  The present invention relates to an ionomer composition, and more particularly to an ionomer composition suitable as a golf ball material. Furthermore, the present invention relates to a golf ball material using the ionomer composition and a golf ball comprising the golf ball material.

  Current golf balls are mainly multi-layer golf balls in which a core portion of a central portion such as a two-piece ball, a three-piece ball, and a four-piece ball is covered with a plurality of elastic material layers and an outermost layer cover is provided. As a material for covering these multi-layer golf balls, a highly repulsive resin material such as an ionomer is widely used.

  In a multilayer golf ball, the material of the core, the cover layer, and the layer (intermediate layer) between the core and the cover layer affects the repulsive force, initial velocity, flight distance, spin performance, and feel at impact of the ball. In general, butadiene rubber is used for the core layer, ionomer-based resin is used for the intermediate layer, and urethane resin or ionomer resin is used for the cover layer. By selecting and combining various materials used for each layer, the repulsive force, initial velocity, flight distance, spin performance, and feel at impact characteristic of each golf ball brand are adjusted. For this reason, various multi-layer balls are manufactured to respond to various preferences and skills of players. In particular, two-piece balls and three-piece balls are sold in a wide range of prices, and are widely used by a wide range of players from amateur players to professional players.

  Ionomer is a material used in many golf ball materials, such as cover layers and intermediate layers of multilayer balls. Therefore, conventionally, improvement of golf ball performance has been attempted by appropriately selecting the ionomer used for each golf ball material and the material used in combination therewith. As such an improved method, it has been proposed to use a special ionomer, for example, an ionomer modified with an amine compound.

Japanese Patent Laid-Open No. 10-127822 Japanese Patent Laid-Open No. 10-137363 Japanese Patent Laid-Open No. 10-137364 JP 11-299933 A

  In Patent Document 1, a diamine complex ionomer is used for the cover layer, and a material having a low flexural modulus is used for the intermediate layer, thereby adjusting the hardness of the ball, resulting in flying performance, impact durability, and soft ball hitting. It is described that a golf ball having a feeling is obtained.

  Patent Document 2 describes that by using a blend of an amine-modified ionomer and an unmodified ionomer for the cover layer, a golf ball having excellent shot feeling and controllability and improved rebound characteristics is obtained. Has been.

  In Patent Document 3, the ionomer-modified ionomer is contained in the inner cover layer, and the inner cover layer and the outer cover layer are made of ionomer-containing compositions having different compositions, thereby providing resilience while maintaining durability. It is described that a golf ball having improved controllability and soft feeling was obtained.

  Patent Document 4 describes that by adding an amine-modified ionomer composition to the cover layer, a golf ball having excellent resilience and flight performance without impairing the feel at impact is obtained.

  As described above, golf balls having an excellent balance of main golf ball performances such as flight distance, controllability, and shot feeling have been proposed using amine-modified ionomers. However, many golf players desire further improvement of the golf ball performance balance. A non-negligible number of golf players are looking for golf balls that are particularly excellent in flight distance. In order to meet the further demands of such golf ball users, a coating resin material with higher rebound resilience and hardness, which is expected to contribute to a golf ball exhibiting a longer flight distance, is desired.

  On the other hand, when an amine-modified ionomer is used, smoke generation at the time of melt-kneading or injection molding of the ionomer may be a problem. For this reason, further improvements are also required for amine-modified ionomers. Until now, it has been reported that smoke generation can be suppressed by selecting an amine compound to be used for ionomer modification. However, a golf ball using a coating material in which such smoke generation is suppressed sufficiently satisfies the requirement for the flight distance. There was a case that could not be satisfied.

  Thus, a golf ball that meets the further demands of users has not yet been obtained. An object of the present invention is to provide an amine-modified ionomer composition that can provide a golf ball with a better flight distance and can suppress smoke generation during melt kneading and injection molding of an ionomer.

  Accordingly, the present inventors have eagerly sought for an ionomer composition that can suppress the generation of smoke and that can provide a golf ball that is further superior in flight distance and resilience compared to conventional golf balls. As a result, it was found that an ionomer composition obtained by blending a specific amine compound with an ionomer using a specific base polymer is effective.

That is, the present invention is as follows.
(Invention 1) An ionomer (A) of an ethylene / unsaturated carboxylic acid copolymer in which the total content of structural units derived from an unsaturated carboxylic acid exceeds 5.4 mol%, and a carboxyl group of the ionomer (A) And an amine compound (B) containing two or more amino groups in one molecule and having a boiling point of 250 ° C. or higher at normal pressure in an amount of 0.01 to 1 equivalent based on object.
(Invention 2) The ionomer composition of Invention 1, wherein the amine compound (B) is an aromatic diamine.
(Invention 3) The ionomer composition of Invention 1, wherein the amine compound (B) is a chain aliphatic polyamine.
(Invention 4) The ionomer composition of Invention 1, wherein the ionomer (A) comprises a zinc ionomer.
(Invention 5) The ionomer composition of Inventions 1-4 used as a golf ball material.
(Invention 6) A golf ball material obtained from the ionomer composition according to any one of Inventions 1 to 5.
(Invention 7) The golf ball material of Invention 6, which is a cover layer or an intermediate layer.
(Invention 8) A golf ball comprising the golf ball material of Invention 6 or 7.

  The ionomer composition of the present invention exhibits higher hardness and rebound resilience, while suppressing smoke generation during melting and injection molding. Such an ionomer composition of the present invention has good workability during processing, and is effective as a golf ball covering material exhibiting higher hardness and rebound resilience. By combining such a cover layer or intermediate layer using the ionomer composition of the present invention with other members, a golf ball having a better flight distance can be produced.

[Component (A): Ionomer (A)]
The ionomer composition of the present invention includes an ionomer component (A). The ionomer (A) is a compound in which at least part of the acid groups of the ethylene / unsaturated carboxylic acid copolymer as a base polymer is neutralized with a metal ion. The ethylene / unsaturated carboxylic acid copolymer that is the base polymer of component (A) is not only a copolymer consisting of only ethylene and unsaturated carboxylic acid, but also a multi-component copolymer in which other copolymerization components are optionally copolymerized. It may be a polymer.

  Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, ethacrylic acid, fumaric acid, crotonic acid, maleic acid, itaconic acid, monomethyl maleate, monoethyl maleate, maleic anhydride, and itaconic anhydride. Examples of the unsaturated carboxylic acid are acrylic acid or methacrylic acid. The unsaturated carboxylic acid may be one type or two or more types.

  Optional other copolymerization components include, for example, methyl acrylate, ethyl acrylate, isobutyl acrylate, nbutyl acrylate, isooctyl acrylate, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, nbutyl methacrylate, Unsaturated carboxylic acid esters such as dimethyl maleate and diethyl maleate, for example, unsaturated hydrocarbons such as propylene, butene, 1,3-butadiene, pentene, 1,3-pentadiene, 1-hexene, such as vinyl acetate, Vinyl esters such as vinyl propionate, for example, oxides such as vinyl sulfate and vinyl nitrate, halides such as vinyl chloride and vinyl fluoride, vinyl group-containing primary and secondary amine compounds, carbon monoxide, sulfur dioxide, etc. Can be illustrated. The ethylene / unsaturated carboxylic acid copolymer may be any of a block copolymer, a random copolymer, and a graft copolymer, but from the viewpoint of industrial availability, a binary random copolymer. It is preferable to use a ternary random copolymer, a binary random copolymer graft copolymer, or a ternary random copolymer graft copolymer, more preferably a binary random copolymer or ternary random copolymer. It is a copolymer.

  The total amount of units derived from the unsaturated carboxylic acid contained in the ethylene / unsaturated carboxylic acid copolymer that is the base polymer of the component (A) of the present invention is 5 with respect to the total of the structural units of the copolymer. More than 0.4 mol%, preferably 6.6 mol% or more, more preferably 7.0 mol% or more, and most preferably 7.3 mol% or more. When the content ratio of the structural unit derived from the unsaturated carboxylic acid exceeds 5.4 mol%, it is advantageous in terms of impact resilience and hardness. The upper limit of the total amount is not limited, but is preferably 10.0 mol% or less from the viewpoint of ease of production and moldability.

  The above optional copolymerization component may be copolymerized in a proportion of generally 15 mol% or less, preferably 10 mol% or less. Such an ethylene / unsaturated carboxylic acid copolymer can be preferably obtained by high-pressure radical copolymerization.

  The ionomer (A) of an ethylene / unsaturated carboxylic acid copolymer can be obtained by ionizing such an ethylene / unsaturated carboxylic acid copolymer by a conventional method. The ethylene / unsaturated carboxylic acid copolymer that can be used for ionization has, for example, a melt flow rate of about 0.01 to 1000 g / 10 min at 190 ° C. and a load of 2160 g, preferably 0.1 to 300 g / 10. It is about a minute. The ionomer (A) can also be obtained by saponification of an ethylene / unsaturated carboxylic acid ester copolymer.

  In the ionomer (A), the metal ions include monovalent metals such as lithium, sodium, potassium, rubidium, and cesium, and polyvalent metals such as zinc, magnesium, calcium, manganese, copper, tin, nickel, cobalt, and aluminum. It can be illustrated. As the monovalent metal, sodium is preferable. As the polyvalent metal, a divalent metal is preferable, and zinc is particularly preferable. In particular, ionomers of divalent metal ions are excellent in smoke generation suppression effect, and zinc ionomer is most preferable. As the ionomer (A), one having a neutralization degree of, for example, 0 to 100%, preferably 5 to 90%, and more preferably 30 to 70% is used.

  Two or more types of ionomer (A) may be used, but a case where at least one type is a zinc ionomer is preferable from the viewpoint of the smoke suppression effect. The proportion of the zinc ionomer in the ionomer (A) is preferably 30% by weight or more, more preferably 40% by weight or more. Further, by using an ethylene / unsaturated carboxylic acid copolymer together with an ionomer, the ethylene / unsaturated carboxylic acid copolymer may be ionized by melt mixing. Commercial products marketed as ionomers (A) may also be used. Examples of the commercially available products include High Milan (registered trademark) series manufactured by Mitsui DuPont Polychemical Co., and Surlyn (registered trademark) manufactured by DuPont. Etc. can be used.

[Component (B): Amine compound (B)]
The ionomer composition of the present invention contains an amine compound (B) containing two or more amino groups in one molecule and having a boiling point at normal pressure (hereinafter referred to as “boiling point”) of 250 ° C. or higher. As the amine compound (B), those which are liquid in the melt kneading temperature range of the ionomer (A) and can be easily mixed and reacted with the ionomer (A) are suitable.

Examples of the amine compound (B) include 1,2-phenylenediamine (boiling point 265 ° C.), 1,4-phenylenediamine (boiling point 267 ° C.), 1,3-bis (aminomethyl) benzene (boiling point 273 ° C.), 1,3-phenylenediamine (boiling point 283 ° C.), 1,4-bis (aminomethyl) benzene (boiling point 370 ° C.), 4,4′-diaminodiphenylmethane (boiling point 450 ° C.), etc. Group diamine, p-menthane-1,8-diamine (boiling point 250 ° C.), 4,4′-methylenebis (cyclohexylamine) (boiling point 340 ° C.), 3,9-bis (3-aminopropyl) -2,4, 8,10-tetraoxaspiro [5.5] undecane (boiling point 390 ° C.) cycloaliphatic diamine having a boiling point of not lower than 250 ° C., such as, the general _{formula: H 2 NCH 2 - (CH} 2 H _{CH 2) n -CH 2 NH 2} ( where n is a boiling point of 250 ° C. or more chain aliphatic polyamines represented by the integer from 2 to 6) are used. However, the boiling point is the boiling point shown by commercial products. The amine compound (B) may be a mixture of two or more.

  Examples of the chain aliphatic polyamine having a boiling point of 250 ° C. or higher include triethylenetetramine (boiling point 267 ° C., a compound represented by the above general formula where n is 2), tetraethylenepentamine (boiling point 340 ° C., n is 3). And a compound represented by the above general formula wherein n is 4). The most preferred amine compounds (B) are 1,3-bis (aminomethyl) benzene and pentaethylenehexamine.

  The blending ratio of component (B) is 0.01 to 1 equivalent, preferably 0.05 to 1 equivalent, more preferably 0, relative to the carboxyl group (both free and ionized) of ionomer (A). .1 to 0.8 equivalents. The “equivalent” here is the ratio of the number of amino groups of the amine compound B to the number of carboxyl groups of the ionomer A. The amino groups include all of primary amino groups, secondary amino groups, and tertiary amino groups. including. Even if the compounding ratio of the amine compound (B) is used in an amount exceeding 1 equivalent with respect to the carboxyl group, the effect of improving the physical properties cannot be expected, and on the contrary, the quality may be deteriorated due to bleeding from the molded product, which is not preferable.

[Optional ingredients]
In the ionomer composition of the present invention, other thermoplastic resins, tackifier resins, waxes, antioxidants, weathering stabilizers, light stabilizers, heat stabilizers, ultraviolet absorbers, lubricants, pigments, dyes are used as necessary. Various additives such as inorganic fillers can be blended.

[Production of ionomer composition]
In the ionomer composition of the present invention, the component (A), the component (B), and the additive to be blended as necessary in a normal melt kneading apparatus are heated to a temperature equal to or higher than the melting point of the component (A), preferably a die temperature of 180. It can be produced by melt-kneading at a temperature of about ~ 240 ° C. In melt mixing, a commonly used mixing apparatus such as a screw extruder, a roll mixer, a Banbury mixer, or the like can be used. When the amine compound (B) is liquid at room temperature, it can be dropped and supplied to the ionomer (A) with a pump and melt-kneaded. When the amine compound (B) is solid at room temperature, the ionomer (A) and the amine compound (B) can be dry blended and melt-kneaded using a mixing apparatus. When two or more ionomers are used as the component (A), they may be mixed with the component (B) at the same time, and only a part of the components is melt-kneaded with the component (B), and the resulting composition is obtained. The product and the remaining ionomer component may be melt-kneaded. Furthermore, when blending optional components, both components may be melt-kneaded after dry blending or melt-kneading the optional components into either component (A) or component (B), or both. You may melt-knead with respect to the melt-kneaded material of (A) and a component (B).

  In the ionomer composition of the present invention, among the various amines, an amine compound (B) containing two or more amino groups in one molecule and having a boiling point of 250 ° C. or higher at normal pressure is selected. This is characterized in that it is combined with an ionomer (A) of an ethylene / unsaturated carboxylic acid copolymer in which the total content of structural units derived from the unsaturated carboxylic acid exceeds 5.4 mol%. In the amine-modified ethylene copolymer composition produced by melting the ionomer composition of the present invention, smoke generation at the time of melting or injection molding is suppressed, and at the same time, a molded product obtained therefrom exhibits extremely high hardness and impact resilience.

[Golf ball materials, golf balls]
The golf ball material comprising the ionomer composition of the present invention may be prepared by adding other thermoplastic resins, tackifying resins, waxes, antioxidants, weathering stabilizers to the components (A) and (B) described above. It can be obtained by blending various additives such as light stabilizers, heat stabilizers, ultraviolet absorbers, lubricants, pigments, dyes, inorganic fillers, etc., and melt-kneading and molding. The melt kneading conditions are the same as in the production of the ionomer composition described above.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. Examples of the ionomer composition of the present invention are shown in Table 1. The amine compound (B) abbreviated in Table 1 is as follows.
BAMB: 1,3-bis (aminomethyl) benzene (boiling point 273 ° C.)
PEHA: pentaethylenehexamine (boiling point 380 ° C.)
The blank in Table 1 indicates that it was not used. Example 8, Example 9, and Comparative Examples 7 to 9 are examples in which two ionomers are blended as an ionomer component in a weight ratio of 1: 1.
[Example 1]
Amount of amine compound (B) shown in Table 1 (0.6 equivalent to the carboxyl group of ionomer (A)) is dropped from the feed port with a pump using a 30 mmφ twin screw extruder. And an ionomer composition was obtained by melt-kneading under a condition of a die temperature of 200 ° C.

In Examples 1 to 9 and Comparative Examples 1 to 9 shown in Table 1, ionomer compositions were obtained according to the method of Example 1. The ionomer composition obtained by the following method was evaluated.
[Hardness (Shore D)]
A 250 mm × 250 mm × 3 mm thick sheet was prepared using a hot press machine in which the ionomer composition was set to 180 ° C. A test piece obtained by punching the sheet into an appropriate size was stored in an atmosphere of 23 ° C. and 50% relative humidity for 2 weeks. Thereafter, the two sheets were overlapped and the hardness (Shore D) was measured with an Asker automatic rubber hardness meter P1-D type. Measurement conditions compliant with JIS K7215.

[Rebound resilience]
A 250 mm × 250 mm × 3 mm thick sheet was prepared using a hot press machine in which the ionomer composition was set to 180 ° C. A test piece having a layer thickness of about 13 mm was prepared with a hot press machine in which five sheets punched to an appropriate size were stacked and set to 160 ° C. again. This test piece was stored in an atmosphere of 23 ° C. and 50% relative humidity for 2 weeks. Then, this test piece was measured with the Lüpke rebound resilience tester. Measurement conditions were based on JIS K6255.

  The evaluation results of each ionomer composition are shown in Table 1.

  Comparative Examples 1, 2, 8, and 9 are outside the scope of the present invention in that the total content of structural units derived from the unsaturated carboxylic acid of ionomer (A) is 5.4 mol% or less. Comparative Examples 1, 2, 8, and 9 have lower hardness than the examples.

  In Comparative Examples 3 and 7, the total content of the structural units derived from the unsaturated carboxylic acid of the ionomer (A) is 5.4 mol% or less, and the component (B) is not used. Out of range. In Comparative Examples 3 and 7, both the resilience modulus and the hardness are low compared to the Examples.

  Comparative Examples 4, 5, and 6 are outside the scope of the present invention in that the component (B) is not used. Comparative Examples 4, 5, and 6 have lower impact resilience and hardness than the examples.

  Thus, the ionomer compositions of the examples exhibit high rebound resilience and high hardness. It can be said that the ionomer compositions of the examples are suitable for materials such as golf ball cover layers and intermediate layers that can achieve a longer flight distance.

Furthermore, a comparative ionomer composition outside the scope of the present invention was produced in that an amine compound having a boiling point of less than 250 ° C. was used. The obtained comparative products (Comparative Example 10 and Comparative Example 11), Example 1, Example 2 and Example 7 were compared in terms of fuming properties during melt kneading of the ionomer composition. The comparison results are shown in Table 2. The amine compounds (B) abbreviated in Table 2 are as follows.
BAMB: 1,3-bis (aminomethyl) benzene (boiling point 273 ° C.).
PEHA: pentaethylenehexamine (boiling point 380 ° C.).
(For comparison) BAC: 1,3-bis (aminomethyl) cyclohexane (boiling point 220 ° C.).

[Smoke generation evaluation]
Rank A: Smoke is not recognized, or the amount of smoke is slight and does not cause a problem.
-Rank B: The amount of smoke generation is large, and the working environment deteriorates.

  From Table 2, it can be seen that Comparative Examples 10 and 11 using 1,3-bis (aminomethyl) cyclohexane having a boiling point of less than 250 ° C. as the amine compound (B) are inferior in smoke suppression effect.

  From the results of Examples and Comparative Examples in Table 1, when the total content of the constituent units derived from the unsaturated carboxylic acid of ionomer (A) exceeds 5.4 mol%, an ionomer having a high rebound resilience and high hardness. It can be seen that a composition is obtained. Moreover, it can be seen from the results of Examples and Comparative Examples in Table 2 that good results can be obtained with respect to smoke suppression particularly when an amine compound (B) having a boiling point of 250 ° C. or higher and a zinc ionomer are used.

  In the ionomer composition of the present invention, smoke generation during melt-kneading in the production thereof is suppressed, and the working environment can be kept good. In addition, since the golf ball material obtained from the ionomer composition of the present invention exhibits extremely high resilience and hardness, it can meet the demands of golf ball users who place great importance on flight distance. Therefore, by using the ionomer composition of the present invention, it becomes possible to manufacture a golf ball material that satisfies the higher demands of consumers and a golf ball product using the same, while taking into consideration the working environment. As a result, according to the present invention, it is possible to simultaneously improve the efficiency of manufacturing golf balls and improve the quality of products.

Claims (8)

The ethylene-unsaturated carboxylic acid copolymer ionomer (A) having a total content of the structural units derived from the unsaturated carboxylic acid exceeding 5.4 mol%, and 0 based on the carboxyl group of the ionomer (A). An ionomer composition comprising an amine compound (B) containing two or more amino groups in one molecule and having a boiling point of 250 ° C. or higher at normal pressure in an amount of 0.01 to 1 equivalent. The ionomer composition according to claim 1, wherein the amine compound (B) is an aromatic diamine. The ionomer composition according to claim 1, wherein the amine compound (B) is a chain aliphatic polyamine.   The ionomer composition according to claim 1, wherein the ionomer (A) comprises a zinc ionomer. The ionomer composition according to any one of claims 1 to 4, which is used for a golf ball material. A golf ball material obtained from the ionomer composition according to any one of claims 1 to 5. The golf ball material according to claim 6, which is a cover layer or an intermediate layer. A golf ball comprising the golf ball material according to claim 6.