KR102654280B1 - Vitrimer Composition, Preparation Method Thereof, and Golf Ball Formed Therefrom - Google Patents

Abstract

The present invention provides a thermoplastic polyester elastomer-based vitrimer composition, a method for producing the same, and a golf ball formed therefrom. The vitrimer composition according to the present invention is partially cross-linked through dynamic bonding and has excellent flowability and melt processability, as well as excellent physical properties such as low compression rate and high rebound. Therefore, the vitrimer composition according to the present invention can be advantageously used in the production of high-performance three-piece or more golf balls.

Description

Vitrimer composition, preparation method thereof, and golf ball formed therefrom {Vitrimer Composition, Preparation Method Thereof, and Golf Ball Formed Therefrom}

The present invention relates to a vitrimer composition, a manufacturing method thereof, and a golf ball formed therefrom, and more specifically, to a vitrimer composition that not only enables environmentally friendly molding and processing but also has excellent physical properties such as low compression rate and high rebound, a manufacturing method thereof, and This relates to the golf ball formed from this.

Recently, high-end golf balls include multi-layer golf balls with 3 or 4 pieces or more. A three-piece golf ball typically includes a spherical rubber core, a mantle layer comprising a thermoplastic elastomer material formed thereon, and a cover layer comprising a thermoplastic or thermoset material covering them.

One of the thermoplastic elastomers that has long proven useful in golf ball components and other applications has been the ionomer of alpha olefins, particularly ethylene and C ₃ -C ₈ α,β-ethylenically unsaturated carboxylic acid copolymers. Various cations capable of neutralizing acid groups in such acid copolymers are known. It is known that the degree of neutralization can vary widely.

Highly neutralized low-hardness, high-elasticity ionomer resin compositions can be used as a mantle layer inside a golf ball due to their high elasticity. A golf ball whose mantle layer is made of a material with a high coefficient of restitution can fly a longer distance when struck with the same force.

Republic of Korea Patent Publication No. 10-2002-0042870 discloses that a melt-processable thermoplastic composition obtained by mixing a sufficient amount of aliphatic monofunctional organic acid in an acid copolymer and then highly neutralizing it is useful for manufacturing golf balls. In addition, Dow's brand names HPF 1000, HPF 2000, etc. are used as ionomer resins to manufacture the mantle layer of three or more pieces of golf balls.

However, existing compositions using large amounts of organic acids present a serious problem of generating a lot of gas during injection molding, contaminating the workplace atmosphere and molds.

Moreover, in accordance with the recent strengthening of the policy of diversifying material supply and demand in the golf ball manufacturing industry, there is a demand for the development and mass production supply of new non-ionomer elastic materials with low compression rate and high rebound.

Republic of Korea Patent Publication No. 10-2002-0042870

One object of the present invention is to provide a vitrimer composition that not only allows environmentally friendly molding processing but also has excellent physical properties such as low compression rate and high resilience.

Another object of the present invention is to provide a method for producing the vitrimer composition.

Another object of the present invention is to provide a golf ball formed from the vitrimer composition.

On the other hand, the present invention is a pre-vitrimer formed by transesterification of a first thermoplastic polyester elastomer and a multifunctional compound having two or more alcohol groups under a zinc (Zn)-based catalyst,

a second thermoplastic polyester elastomer, and

A vitrimer composition comprising a multifunctional compound having two or more glycidyl groups is provided.

The vitrimer composition according to one embodiment of the present invention may be one in which the pre-vitrimer and the second thermoplastic polyester elastomer are crosslinked by a multifunctional compound having two or more glycidyl groups.

The vitrimer composition according to an embodiment of the present invention includes the hydroxyl group and carboxyl group of the pre-vitrimer and the second thermoplastic polyester elastomer, and the glycidyl group and epoxide ring opening of the multifunctional compound having two or more glycidyl groups. It may be cross-linked by reaction.

In one embodiment of the present invention, the first and second thermoplastic polyester elastomers may have a Shore D hardness of 40 to 55.

In one embodiment of the present invention, the first and second thermoplastic polyester elastomers may have a melting point (T _m ) of more than 150°C and less than 220°C.

In one embodiment of the present invention, the multifunctional compound having two or more alcohol groups may be used in an amount of 0.05 to 2 parts by weight based on 100 parts by weight of the first thermoplastic polyester elastomer.

In one embodiment of the present invention, the pre-vitrimer may have a melt index of 50 to 100 g/10min measured at 230°C and 2.16 kg according to ASTM D1238.

In one embodiment of the present invention, the second thermoplastic polyester elastomer may be the same as the first thermoplastic polyester elastomer.

In one embodiment of the present invention, the mixing ratio of the pre-vitrimer and the second thermoplastic polyester elastomer may be 30:70 to 50:50 by weight.

In one embodiment of the present invention, the multifunctional compound having two or more glycidyl groups may be included in an amount of 0.01 to 2.0 parts by weight based on 100 parts by weight of the total amount of the pre-vitrimer and the second thermoplastic polyester elastomer. .

The vitrimer composition according to an embodiment of the present invention may have a melt index of 5 to 25 g/10min measured at 230°C and 2.16 kg according to ASTM D1238.

When the vitrimer composition according to an embodiment of the present invention is molded into a sphere with a diameter of 1.50 to 1.54 inches, the coefficient of restitution (COR) of the sphere is 0.785 or more and the compression ratio is 75 or less,

The coefficient of restitution can be determined by firing the ball at a speed of 125 feet/sec onto a steel plate located 3 feet away from the initial velocity measurement point and dividing the rebound velocity from the steel plate by the initial velocity. there is.

On the other hand, the present invention

(i) obtaining a pre-vitrimer by transesterifying a first thermoplastic polyester elastomer and a multifunctional compound having two or more alcohol groups under a zinc (Zn)-based catalyst; and

(ii) cross-linking the pre-vitrimer and the second thermoplastic polyester elastomer obtained in step (i) with a multifunctional compound having two or more glycidyl groups. do.

In one embodiment of the present invention, the transesterification reaction in step (i) and the crosslinking in step (ii) may be performed under melt conditions in an extruder.

On the other hand, the present invention provides a golf ball comprising a core, a cover layer, and at least one mantle layer present between the core and the cover layer, wherein the mantle layer is formed from the vitrimer composition. do.

The vitrimer composition according to the present invention not only allows environmentally friendly molding processing, but also has excellent physical properties such as low compression rate and high resilience. Therefore, the vitrimer composition according to the present invention can be advantageously used in the production of high-performance three-piece or more golf balls.

1 is a cross-sectional view of a golf ball according to an embodiment of the present invention.
Figure 2 is an FT-IR spectrum of the pre-vitrimer of Preparation Example 2.
Figure 3 is a DSC thermogram of the pre-vitrimer of Preparation Example 2.
Figure 4 is an FT-IR spectrum of the vitrimer composition of Example 1.
Figure 5 is a DSC thermogram of the vitrimer composition of Example 1.

Hereinafter, the present invention will be described in more detail.

One embodiment of the present invention is

A pre-vitrimer (A) formed by transesterification of a first thermoplastic polyester elastomer and a multifunctional compound having two or more alcohol groups under a zinc (Zn)-based catalyst,

a second thermoplastic polyester elastomer (B), and

It relates to a vitrimer composition comprising a multifunctional compound (C) having two or more glycidyl groups.

The vitrimer composition according to one embodiment of the present invention may be one in which the pre-vitrimer and the second thermoplastic polyester elastomer are crosslinked by a multifunctional compound having two or more glycidyl groups.

Specifically, the vitrimer composition according to one embodiment of the present invention has the hydroxy group and carboxyl group of the pre-vitrimer and the second thermoplastic polyester elastomer, and the glycidyl group of the multifunctional compound having two or more glycidyl groups. It may be cross-linked through an epoxide ring-opening reaction.

The vitrimer composition according to one embodiment of the present invention has vitrimer properties due to dynamic cross-linking in which the exchange reaction of the cross-linking occurs.

Vitrimer refers to a polymer crosslinked with controllable dynamic bonds between polymer chains.

The vitrimer composition according to one embodiment of the present invention is partially cross-linked through dynamic bonding through an epoxide ring-opening reaction, and thus has excellent flowability and melt processability, as well as excellent physical properties such as low compression rate and high resilience.

Specifically, the vitrimer composition according to an embodiment of the present invention includes a pre-vitrimer having a short chain length and a hydroxyl group and a carboxyl group present at the ends of the second thermoplastic polyester elastomer having a longer chain length compared to the pre-vitrimer, and two or more glycol groups. It is partially cross-linked to a level that maintains thermoplasticity through an epoxide ring-opening reaction with the glycidyl group of a multifunctional compound having a cidyl group, so it not only has excellent flowability and melt processability, but also has a high cross-linking density, resulting in low compression ratio and It has excellent properties of high resilience.

Additionally, the vitrimer composition according to one embodiment of the present invention generates little gas during injection molding.

Pre-bitrimer (A)

In one embodiment of the present invention, the pre-vitrimer (A) is a polymer mixture formed by transesterification of a first thermoplastic polyester elastomer and a multifunctional compound having two or more alcohol groups under a zinc (Zn)-based catalyst.

The chain length of the first thermoplastic polyester elastomer is reduced by the transesterification reaction.

In one embodiment of the present invention, the first thermoplastic polyester elastomer is a thermoplastic block copolymer having hard segments and soft segments. The hard segments and soft segments may be randomly arranged.

The hard segment includes polybutylene terephthalate (PBT) blocks, and in addition, crystals formed from the condensation reaction of aromatic dicarboxylic acid, cycloaliphatic dicarboxylic acid and/or aliphatic dicarboxylic acid and aliphatic or cycloaliphatic diol. It may further include a copolymer block.

The aromatic dicarboxylic acid is not limited to use as long as it is a common aromatic dicarboxylic acid, and includes terephthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, isophthalic acid, 5-sodium sulfoisophthalic acid, etc. You can. There are no restrictions on use of the alicyclic dicarboxylic acid as long as it is a typical alicyclic dicarboxylic acid, and examples include cyclohexane dicarboxylic acid and tetrahydrophthalic anhydride. There are no restrictions on the use of the aliphatic dicarboxylic acids as long as they are common aliphatic dicarboxylic acids, and include succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecane diacid, dimer acid, hydrogenated dimer acid, etc. I can hear it. They are used in a range that does not significantly lower the melting point of the resin, and the amount is not necessarily limited to this, but considering the acidic components that form PBT, it should be less than 30 mol%, more preferably less than 20 mol%, of the total acidic components. can be used

The aliphatic or cycloaliphatic diol forming the hard segment is also not particularly limited, but is preferably mainly alkylene glycols having 2 to 8 carbon atoms, more specifically ethylene glycol, 1,3-propylene glycol, 1,4- At least one of butanediol, 1,6-hexanediol, and 1,4-cyclohexanedimethanol can be used.

The soft segment includes a polytetramethylene ether glycol (PTMEG) block and may further include a soft block formed from polyalkylene oxide glycol.

The polyalkylene oxide glycol may be polytetramethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol with an ethylene oxide terminal, copoly(ethylene-propylene oxide) glycol, etc. having a number average molecular weight of 1,000 to 2,000. . These may form soft blocks alone, excluding PTMEG, but may include terephthalic acid, or lower alkyl ester compounds thereof; and/or isophthalic acid, orthophthalic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, or a mixture of lower alkyl ester compounds thereof to form a soft block.

In one embodiment of the present invention, the content ratio of the hard segment and the soft segment may be 90:10 to 30:70 by weight, and is preferably 85% in order to facilitate polymerization and sufficiently exhibit properties as an elastic material. :15 to 15:85, more preferably 80:20 to 20:80, even more preferably 75:25 to 25:75, and even more preferably 70:30 to 30:70. As the hard segment and soft segment have the above ratio range, the first thermoplastic polyester elastomer can have a relatively low crystallinity, and as a result, the area of the melting peak during differential scanning calorimetry (DSC) thermal analysis is 10 to 30 J/ It can be adjusted within the range of g.

In one embodiment of the present invention, the first thermoplastic polyester elastomer may have a Shore D hardness of 40 to 55.

The Shore D hardness is a value measured according to ASTM D2240.

If the Shore D hardness of the first thermoplastic polyester elastomer is within the above range, a golf ball with excellent spin control can be provided.

In one embodiment of the present invention, the first thermoplastic polyester elastomer may have a melting point (T _m ) of more than 150°C and less than 220°C.

The melting point (T _m ) is a value measured according to ASTM D3418.

Specifically, the melting point (T _m ) can be measured by thermal analysis using a differential scanning calorimeter (DSC), for example, by first heating above the melting point at a rising rate of 10°C/min under an inert gas atmosphere, This can be determined as the peak temperature of the melting peak in the heat curve obtained by cooling it back to room temperature at a falling rate of 10°C/min and then heating it again at a rising rate of 10°C/min.

The melting point (T _m ) of the first thermoplastic polyester elastomer may be, for example, 151 to 210°C, 152 to 208°C, and preferably 155 to 205°C. If the melting point (T _m ) is 150°C or lower, the hardness may decrease and the COR value may decrease, and if it is 220°C or higher, the hardness may be too high, causing the golf ball to become hard.

In addition, the first thermoplastic polyester elastomer has a melting peak area of 10 to 30 J/g, for example, 10.5 to 29.5 J/g, 11 to 29.0 J/g in the heat curve obtained by thermal analysis using DSC. g, 11.5 to 29.0 J/g, 12.0 to 28.5 J/g, 12.5 to 28.0 J/g, 13.0 to 27.5 J/g, 13.5 to 27.0 J/g, 14.0 to 26.5 J/g, 14.5 to 27.0 J/g , 15.0 to 26.0 J/g, or 15.5 to 25.5 J/g.

In one embodiment of the present invention, the first thermoplastic polyester elastomer each independently has a number average molecular weight of 5,000 to 500,000 g/ as measured by the gel permeation chromatography (GPC) method of the tetrahydrofuran (THF) soluble fraction. mol, for example 10,000 to 300,000, 10,000 to 250,000, 10,000 to 230,000, 10,000 to 220,000, 10,000 to 210,000, 10,000 to 200,000, 10,000 to 190,000, Can be 10,000 to 180,000, 11,000 to 180,000, or 11,000 to 150,000 g/mol there is. If the number average molecular weight is less than 5,000 g/mol, the mechanical properties such as tensile strength and toughness of the product obtained from the composition may be poor, and if it is more than 500,000 g/mol, the melt processability of the composition may be poor.

In one embodiment of the present invention, the polyfunctional compound having two or more alcohol groups refers to a compound having two or more alcohol groups in the molecule, that is, a polyhydric alcohol.

Examples of the polyfunctional compound having two or more alcohol groups include glycerin, 1,2-ethanediol, pentaerythritol, etc., and glycerin is particularly preferred. These can be used individually or in combination of two or more types.

The multifunctional compound having two or more alcohol groups may be used in an amount of 0.05 to 2 parts by weight, for example, 0.1 to 1.0 parts by weight, based on 100 parts by weight of the first thermoplastic polyester elastomer. If the multifunctional compound having two or more alcohol groups is used in an amount less than the above range, transesterification reaction may not occur, and if it is used in an amount exceeding the above range, the transesterification reaction may occur too much and the elongation may decrease.

In one embodiment of the present invention, the zinc (Zn)-based catalyst can be used without limitation as long as it is used in transesterification reaction, and examples include zinc acetylacetonate and zinc acetate. These can be used individually or in combination of two or more types.

The zinc (Zn)-based catalyst may be used in an amount of 0.01 to 0.5 parts by weight based on 100 parts by weight of the first thermoplastic polyester elastomer. If the zinc (Zn)-based catalyst is used in the above range, the transesterification reaction can occur efficiently.

The zinc (Zn)-based catalyst is preferably used in an amount of 1/10 to 2/10 of the content of the multifunctional compound having two or more alcohol groups.

In one embodiment of the present invention, the pre-vitrimer (A) may have a melt index of 50 to 100 g/10min measured at 230°C and 2.16 kg according to ASTM D1238. If the pre-vitrimer has a melt index in the above range, it has many crosslinking points and has excellent elasticity during crosslinking.

In one embodiment of the present invention, the pre-vitrimer (A) may have an elongation of 100% or more, for example, 100 to 300%. If the elongation is less than 100%, low-temperature durability may deteriorate.

Second thermoplastic polyester elastomer (B)

In one embodiment of the present invention, the second thermoplastic polyester elastomer (B) may be the same as the first thermoplastic polyester elastomer described above. Accordingly, detailed description is omitted.

In one embodiment of the present invention, the mixing ratio of the pre-vitrimer (A) and the second thermoplastic polyester elastomer (B) may be 30:70 to 50:50 by weight. When the mixing ratio of the pre-vitrimer (A) and the second thermoplastic polyester elastomer (B) is within the above range, elasticity is excellent during crosslinking.

Multifunctional compound having two or more glycidyl groups (C)

In one embodiment of the present invention, the multifunctional compound (C) having two or more glycidyl groups is a compound having two or more glycidyl groups in the molecule, for example, ethylene glycol diglycidyl ether, 1, Examples include 4-butanediol diglycidyl ether, 1,3,5-triglycidyl isocyanurate (TGIC), triglycidyloxybiphenyl, and tetraglycidyloxybiphenyl, especially 1,3. ,5-Triglycidylisocyanurate (TGIC) is preferred. These can be used individually or in combination of two or more types.

In one embodiment of the present invention, the multifunctional compound (C) having two or more glycidyl groups is used in an amount of 0.01 to 2.0 parts by weight based on 100 parts by weight of the total amount of the pre-vitrimer and the second thermoplastic polyester elastomer. may be included. When the multifunctional compound having two or more glycidyl groups is included in the above content range, thermoplasticity can be maintained while partially crosslinked.

Additive (D)

The vitrimer composition according to an embodiment of the present invention may further include various additives (D) as needed in addition to the components described above.

Examples of the additive (D) include antioxidants, heat stabilizers, light stabilizers, lubricants, reinforcing agents (e.g., silicone resins), hydrolysis inhibitors, ultraviolet absorbers, pigments, dyes, lubricants, anti-blocking agents, etc.

Examples of the antioxidant include hindered amine-based antioxidants, hindered phenol-based antioxidants, phosphite-based antioxidants, amide-based antioxidants, thioester-based antioxidants, or these. Combinations include, more specifically, 4,4'-bis(α,α-diphenylbenzyl) diphenyl amine (Naugard 445 from Chemtura), octadecyl-3-(3,5-di-tert-butyl) Examples include -4-hydroxyphenyl)-propionate (Irganox 1076 from BASF), but it is not limited thereto.

These additives are preferably used in an amount of 0.1 to 4 parts by weight in total, and 0.05 to 1 part by weight for each additive, based on 100 parts by weight of the vitrimer composition.

The vitrimer composition according to an embodiment of the present invention may have a melt index of 5 to 25 g/10min measured at 230°C and 2.16 kg according to ASTM D1238. If the vitrimer composition according to one embodiment of the present invention has a melt index in the above range, molding processing is advantageous.

The vitrimer composition according to one embodiment of the present invention is a highly elastic material with a high coefficient of restitution (COR).

Specifically, when the vitrimer composition according to one embodiment of the present invention is molded into a sphere with a diameter of 1.50 to 1.54 inches, the coefficient of restitution (COR) of the sphere is 0.785 or more, for example, 0.788 or more. and the compression ratio may be 75 or less, for example, 74 or less, or 70 or less.

The coefficient of restitution (COR) is calculated by firing the ball at a speed of 125 feet/sec onto a steel plate located 3 feet away from the initial velocity measurement point and dividing the rebound velocity from the steel plate by the initial velocity. can be decided.

The compression rate is defined as the total resistance to deflection experienced by the golf ball when a compressive load is applied.

The compression ratio can be measured by the method described in the experimental example described later.

The above coefficient of restitution and compression rate ranges are desirable in terms of golf ball performance.

The vitrimer composition according to one embodiment of the present invention may have Shore D hardness of 40 to 55.

The vitrimer composition according to an embodiment of the present invention can control hardness in various ways within the above range, making it easier to control compression rate and COR compared to existing ionomer resins, thereby increasing the degree of freedom in designing three or more pieces of golf balls.

In addition, the vitrimer composition according to one embodiment of the present invention has a high coefficient of restitution and a low compressibility as described above, and is useful as a material for the mantle layer of three or more pieces of golf balls by replacing the existing low compression rate and high repulsion ionomer composition. It can be used effectively.

One embodiment of the present invention is

(i) obtaining a pre-vitrimer by transesterifying a first thermoplastic polyester elastomer and a multifunctional compound having two or more alcohol groups under a zinc (Zn)-based catalyst; and

(ii) cross-linking the pre-vitrimer and the second thermoplastic polyester elastomer obtained in the first step with a multifunctional compound having two or more glycidyl groups. .

In step (i), in order to reduce the chain length of the first thermoplastic polyester elastomer, the first thermoplastic polyester elastomer is subjected to a transesterification reaction with a polyfunctional compound having two or more alcohol groups in the presence of a zinc (Zn)-based catalyst to form a pre-b. This is the step of manufacturing the trimmer.

The first thermoplastic polyester elastomer, the multifunctional compound having two or more alcohol groups, the zinc (Zn)-based catalyst, and the pre-vitrimer have already been described in the description of the vitrimer composition, and detailed descriptions thereof will be omitted.

The transesterification reaction of step (i) may be performed under melt conditions in an extruder.

Specifically, in step (i), the first thermoplastic polyester elastomer, a multifunctional compound having two or more alcohol groups, and a zinc (Zn)-based catalyst are supplied to the hopper of the twin-screw extruder, and then the barrel temperature of the twin-screw extruder is raised. The transesterification reaction can be performed by uniformly mixing and melting the ingredients while transferring them to the tip of the barrel while transferring the ingredients supplied through the hopper.

The melting condition may be a temperature condition higher than the melting point (T _m ) of the first thermoplastic polyester elastomer, for example, it may be a temperature condition of melting point (T _m )+20°C to melting point (T _m )+30°C. Specifically, the melting conditions may be a temperature condition of 190 to 250°C.

The step (ii) is cross-linking the resin mixture of the pre-vitrimer and the second thermoplastic polyester elastomer obtained in step (i) with a multifunctional compound having two or more glycidyl groups to obtain a vitrimer composition. It's a step.

The crosslinking in step (ii) may be performed under melt conditions in an extruder.

Specifically, in step (ii), the pre-vitrimer, the second thermoplastic polyester elastomer, and the multifunctional compound having two or more glycidyl groups obtained in step (i) are supplied to the hopper of a twin-screw extruder, This can be performed by raising the temperature of the barrel of the twin-screw extruder and transferring the components supplied through the hopper to the tip of the barrel, uniformly mixing and melting these components, and crosslinking them.

The crosslinking may be performed within a level at which the vitrimer composition maintains thermoplasticity. That is, the cross-linking may be performed by partially cross-linking the pre-vitrimer and the second thermoplastic polyester elastomer, and the multifunctional compound having two or more glycidyl groups.

Specifically, the cross-linking may be performed at a level where the vitrimer composition has a melt index in the range of 5 to 25 g/10 min, measured at 230°C and 2.16 kg according to ASTM D1238.

The melting conditions may be a temperature condition higher than the melting point (T _m ) of the second thermoplastic polyester elastomer, for example, a temperature condition of melting point (T _m )+20°C to melting point (T _m )+30°C. Specifically, the melting conditions may be a temperature condition of 190 to 250°C.

In steps (i) and (ii), before feeding each component to the hopper of the twin-screw extruder, each component may be sufficiently homogeneously kneaded in advance using a mixer such as a ribbon mixer.

Afterwards, the vitrimer composition can be processed into three or more pieces of mantle layers for golf balls by, for example, being put into an injection molding process.

Accordingly, one embodiment of the present invention relates to a golf ball having a mantle layer formed from the vitrimer composition described above.

Referring to FIG. 1, a golf ball according to an embodiment of the present invention includes a core 10, a cover layer 30, and a mantle layer 20 existing between the core 10 and the cover layer 30. Includes. Although Figure 1 shows a configuration with a single mantle layer, the mantle layer may exist as two or more multiple layers.

The core 10 is the innermost layer of the golf ball and may have a single layer or a multi-layer structure of two or more layers.

The core 10 material may be any known core material, for example, thermosetting materials such as rubber, styrene butadiene, polybutadiene, isoprene, polyisoprene, and trans-isoprene; Thermoplastic materials such as ionomer resins, polyamides or polyesters; Thermoplastic and thermosetting polyurethane or polyurea elastomers may be included.

The cover layer 30 is the outermost layer of the golf ball and has a single-layer structure.

Any known cover layer material may be used as the material for the cover layer 30, and examples include ionomer resin, thermosetting/thermoplastic polyurethane, etc.

The mantle layer 20 may be formed using the above-described vitrimer composition to cover the core 10.

Hereinafter, the present invention will be described in more detail through examples, comparative examples, and experimental examples. These examples, comparative examples, and experimental examples are only for illustrating the present invention, and it is obvious to those skilled in the art that the scope of the present invention is not limited thereto.

Preparation Examples 1 to 4: Preparation of pre-vitrimer

Each component was weighed and mixed according to the composition shown in Table 1 below, and then fed into the twin-screw extruder (32 mm, L/D = 44; manufacturer: Uniplus, product number: UNEE 32-44) through the hopper.

A pre-vitrimer was prepared by melt extrusion while maintaining the shaft rotation speed of the twin-screw extruder in the range of about 200 to 400 rpm and the barrel temperature at about 190 to 250°C.

Experimental Example 1:

The tensile strength at break, elongation at break, melt index, and hardness of the pre-vitrimer prepared in the above production example were measured by the following methods, and the measurement results are shown in Table 1 below. In addition, FT-IR and DSC analysis were performed as follows, and the results are shown in Figures 2 and 3, respectively.

(1) Tensile strength and elongation at break

Tensile strength at break and elongation at break were measured according to ASTM D638.

(2) Melt index

The melt index was measured at a temperature of 230°C and a load of 2.16 kg according to ASTM D1238.

(3) Hardness

Hardness was measured as Shore D hardness according to ASTM D2240.

(4) FT-IR

FT-IR was analyzed using PerkinElmer's Spectrum2 instrument.

(5) DSC analysis

Differential scanning calorimetry (DSC) analysis was performed using a DSC 4000 Lab system while raising the temperature at 10°C/min.

Manufacturing Example 1 Production example 2 Production example 3 Production example 4 Composition (parts by weight) H45DLG 100 100 H55DLG 100 100 glycerin 0.25 0.5 0.25 0.5 Zn-based catalyst 0.1 0.1 0.1 0.1 Properties Tensile strength at break (MPa) 24.5 24.1 32.8 31.6 Elongation at break (%) >300 >300 >300 >300 Melt rate (g/10min) 45 97 51 102 Hardness (Shore D) 45 45 55 55

H45DLG (Hetron): thermoplastic polyester elastomer (Shore D hardness: 45, melting point) with hard segments containing polybutylene terephthalate (PBT) blocks and soft segments containing polytetramethylene ether glycol (PTMEG) blocks. : 190℃)

H55DLG (Hetron): thermoplastic polyester elastomer (Shore D hardness: 55, melting point) comprising hard segments containing polybutylene terephthalate (PBT) blocks and soft segments containing polytetramethylene ether glycol (PTMEG) blocks. : 204℃)

Zn-based catalyst: zinc acetylacetonate

Through Table 1, it was shown that the pre-vitrimer of Preparation Examples 2 and 3 was within an appropriate melt index range.

Figures 2 and 3 are FT-IR spectra and DSC thermograms of the pre-vitrimer of Preparation Example 2, respectively.

Through Figure 2, it can be seen that the transesterification reaction of the thermoplastic polyester elastomer has progressed.

In addition, through Figure 3, it can be confirmed that the crystallization temperature of the pre-vitrimer of Preparation Example 2 is 146.27°C and the melting point is 184.93°C.

Examples 1 to 4: Preparation of vitrimer compositions

Each component was weighed and mixed according to the composition shown in Table 2 below, and then fed into the twin-screw extruder (32 mm, L/D = 44; manufacturer: Uniplus, product number: UNEE 32-44) through the hopper.

A vitrimer composition was prepared by melt extrusion while maintaining the shaft rotation speed of the twin-screw extruder in the range of about 200 to 400 rpm and the barrel temperature at about 190 to 250°C.

Experimental Example 2:

The tensile strength at break, elongation at break, melt index, and hardness of each vitrimer composition prepared in the above examples were measured by the method described in Experimental Example 1, and the measurement results are shown in Table 2 below. In addition, FT-IR and DSC analysis were performed as described in Experimental Example 1 above, and the results are shown in Figures 4 and 5, respectively.

Example 1 Example 2 Example 3 Example 4 Composition (parts by weight) H45DLG 70 50 Production example 2 30 50 H55DLG 70 50 Production example 3 30 50 TGIC 0.25 0.5 0.25 0.5 Properties Tensile strength at break (MPa) 25.1 23.8 35.6 33.1 Elongation at break (%) >500 >500 >500 >500 Melt rate (g/10min) 15.6 17.4 14.3 16.4 Hardness (Shore D) 45 45 55 55

TGIC: 1,3,5-triglycidyl isocyanurate

Through Table 2, it was confirmed that the vitrimer compositions of Examples 1 to 4 had increased elongation at break and decreased melt index compared to the pre-vitrimer compositions of Preparation Examples 1 to 4.

Figures 4 and 5 are FT-IR spectra and DSC thermograms of the vitrimer composition of Example 1, respectively.

Through Figure 4, it can be seen that crosslinking occurred between the pre-vitrimer and the thermoplastic polyester elastomer.

In addition, through Figure 5, it can be seen that the crystallization temperature of the vitrimer composition of Example 1 is 148.92°C and the melting point is 183.10°C. Therefore, it can be seen that the crystallization temperature of the vitrimer composition of Example 1 increased compared to the crystallization temperature of the pre-vitrimer of Preparation Example 2. This means that the vitrimer composition of Example 1 has a higher degree of chemical crosslinking than the pre-vitrimer of Preparation Example 2, and through this, the vitrimer composition of Example 1 has a higher degree of chemical crosslinking than the pre-vitrimer of Preparation Example 2 and the second thermoplastic polyester. It can be seen that the elastomer H45DLG was formed by chemically crosslinking with TGIC.

Experimental Example 3:

Using each of the vitrimer compositions prepared in the above examples, spheres were formed as follows, and various physical properties required for the mantle layer for golf balls were measured. The results are shown in Table 3 below.

To compare physical properties, as Comparative Example 1, spheres were molded using Dow's HPF 1000, an ionomer resin, and physical properties were measured.

<Formation of sphere>

Each of the Vitrimer compositions and HPF 1000 prepared in the above examples were melted and injection molded into spherical specimens the size of golf balls with a diameter of 1.52 inches.

(1) Compression rate and compression deformation amount

Compression and compression strain were measured using a golf ball compressive strength tester from Atti, USA.

(2) Coefficient of restitution

The coefficient of restitution was determined by launching the ball at a speed of 125 feet/sec onto a steel plate located 3 feet away from the initial velocity measurement point and dividing the rebound velocity from the steel plate by the initial velocity.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 compressibility 73 73 74 74 74 Compression deformation (%) 0.145 0.145 0.148 0.148 0.145 Weight(g) 42.24 42.18 42.26 42.17 42.16 COR 0.788 0.789 0.798 0.799 0.799

As shown in Table 3, it can be seen that the spheres formed from the vitrimer compositions of Examples 1 to 4 according to the present invention have a coefficient of restitution (COR) greater than 0.785 and a compression ratio of less than 75. This shows similar compressibility and coefficient of restitution values compared to the sphere of Comparative Example 1 formed from the ionomer resin previously used in the mantle layer of golf balls.

Therefore, it can be confirmed that the vitrimer composition according to the present invention can be used as a replacement material for the existing ionomer resin for the mantle layer of a three-piece or more golf ball.

As the specific parts of the present invention have been described in detail above, it is clear to those skilled in the art that these specific techniques are merely preferred embodiments and do not limit the scope of the present invention. do. Anyone skilled in the art to which the present invention pertains will be able to make various applications and modifications within the scope of the present invention based on the above contents.

Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (15)

A pre-vitrimer formed by transesterification of a first thermoplastic polyester elastomer and a multifunctional compound having two or more alcohol groups under a zinc (Zn)-based catalyst,
a second thermoplastic polyester elastomer, and
A vitrimer composition comprising a multifunctional compound having two or more glycidyl groups. The vitrimer composition according to claim 1, wherein the pre-vitrimer and the second thermoplastic polyester elastomer are crosslinked by a multifunctional compound having two or more glycidyl groups. The method of claim 1, wherein the hydroxyl group and carboxyl group of each of the pre-vitrimer and the second thermoplastic polyester elastomer are crosslinked with the glycidyl group of the multifunctional compound having two or more glycidyl groups through an epoxide ring-opening reaction. A vitrimer composition. The vitrimer composition of claim 1, wherein the first and second thermoplastic polyester elastomers have Shore D hardness of 40 to 55. The vitrimer composition of claim 1, wherein the first and second thermoplastic polyester elastomers have a melting point (T _m ) of more than 150°C and less than 220°C. The vitrimer composition according to claim 1, wherein the multifunctional compound having two or more alcohol groups is used in an amount of 0.05 to 2 parts by weight based on 100 parts by weight of the first thermoplastic polyester elastomer. The vitrimer composition according to claim 1, wherein the pre-vitrimer has a melt index of 50 to 100 g/10 min measured at 230° C. and 2.16 kg according to ASTM D1238. The vitrimer composition of claim 1, wherein the second thermoplastic polyester elastomer is the same as the first thermoplastic polyester elastomer. The vitrimer composition according to claim 1, wherein the mixing ratio of the pre-vitrimer and the second thermoplastic polyester elastomer is 30:70 to 50:50 by weight. The vitrimer composition of claim 1, wherein the multifunctional compound having two or more glycidyl groups is contained in an amount of 0.01 to 2.0 parts by weight based on 100 parts by weight of the total amount of the pre-vitrimer and the second thermoplastic polyester elastomer. . The vitrimer composition of claim 1, wherein the vitrimer composition has a melt index of 5 to 25 g/10 min measured at 230°C and 2.16 kg according to ASTM D1238. The method of claim 1, wherein when the vitrimer composition is molded into a sphere with a diameter of 1.50 to 1.54 inches, the coefficient of restitution (COR) of the sphere is 0.785 or more and the compression ratio is 75 or less,
The coefficient of restitution is determined by launching the ball at a speed of 125 feet/sec onto a steel plate located 3 feet away from the initial velocity measurement point and dividing the rebound velocity from the steel plate by the initial velocity. Vitrimer composition. (i) obtaining a pre-vitrimer by transesterifying a first thermoplastic polyester elastomer and a multifunctional compound having two or more alcohol groups under a zinc (Zn)-based catalyst; and
(ii) A method for producing a vitrimer composition comprising the step of crosslinking the pre-vitrimer and the second thermoplastic polyester elastomer obtained in step (i) with a multifunctional compound having two or more glycidyl groups. The method of claim 13, wherein the transesterification reaction in step (i) and the crosslinking in step (ii) are performed under melt conditions in an extruder. A golf ball comprising a core, a cover layer, and at least one mantle layer present between the core and the cover layer, wherein the mantle layer is formed from the vitrimer composition according to any one of claims 1 to 12. Golf ball.