KR101937663B1 - Composition for golf ball cover using the Self-healing crosslinked polyurethane and method for preparation of golf ball cover using the same - Google Patents

Abstract

The present invention relates to a self-healing crosslinkable polyuretane and a golf ball cover composition comprising the same. The golf ball cover composition comprises 1 to 20 parts by weight of a thermoplastic polyurethane (TPU) A self-healing crosslinked polyurethane which is prepared by mixing and exchanging a polyurethane prepolymer and 0 to 10 parts by weight of a polyamide, is a self-healing crosslinked polyurethane golf ball cover composition.
The golf ball cover composition of the present invention is capable of injection molding by ensuring the flowability of urethane because crosslinking of polyurethane is broken at a high temperature of 180 ° C or more, and as a result of injection molding, problems in process of manufacturing urethane cover by conventional casting It has an effect to overcome. In addition, the self-healing crosslinked polyurethane prepared by using the golf ball cover composition of the present invention has a good rebound resilience and is excellent in mechanical properties of the polyurethane elastomer due to the formation of cross- The performance is excellent.

Description

TECHNICAL FIELD The present invention relates to a golf ball cover composition including a self-healing crosslinked polyurethane, a golf ball cover and a golf ball made from the composition,

The present invention relates to a golf ball cover composition including a self-healing crosslinked polyurethane, a golf ball cover made of the composition, and a golf ball including the golf ball cover. The golf ball includes a magnetic layer having excellent rebound resilience, Healing crosslinked polyurethane and a golf ball cover composition containing the same.

The cover of the premium golf ball mainly used by the amateurs or professionals is mainly composed of the outer cover and the inner cover. The inner cover is made of strong, rigid and elastic ionomer resin. The outer cover is made of soft and rigid polyurethane resin As a dual cover. The ionomer resin not only protects the inner core when striking a golf ball, but also transfers the force to the center in a completely central way to keep the distance far away, and the polyurethane outer cover is easy to impart a back spin to the golf ball when hitting with an iron It is to facilitate control of the ball on the green. When the dual cover is combined with a single core, it becomes a three-piece golf ball, and when combined with a dual core, it becomes a four-piece golf ball.

A polyurethane prepolymer used in a golf ball has been mixed with a curing agent to form a two-component type and is mainly manufactured by a casting molding method. There is a problem that it is difficult to control the hardening speed because it is a two-liquid curing type mixed with a curing agent. In addition, since the initial investment cost for the casting molding process facility is large, the existing ionomer injection molding process facilities can not be used, so that it is very burdensome to set up a separate casting molding process facility for the urethane cover molding.

Korean Patent No. 1500430 Korean Patent No. 1632163 Chinese Patent Publication No. 10788937 U.S. Patent No. 7906575

Disclosure of the Invention The present invention has been made to overcome the above-mentioned problems and conventional problems, and it is an object of the present invention to overcome the problems in the process of manufacturing a urethane cover by conventional casting, The composition of the material and the production method of the injection-molded crosslinked polyurethane.

In order to solve the above technical problems, the polyurethane golf ball cover composition of the present invention comprises 1 to 20 parts by weight of a block polyurethane prepolymer, 0 to 10 parts by weight of a poly (ethylene terephthalate) polyurethane based on 100 parts by weight of a thermoplastic polyurethane (TPU) And self-healing crosslinked polyurethanes prepared by mixing and exchanging amides.

According to a suitable example of the present invention, the block polyurethane prepolymer used for producing the self-healing crosslinked polyurethane contained in the composition of the present invention is prepared by reacting a diisocyanate with a crosslinking polyol having three or more hydroxy groups, Preparing a cross-linked polyurethane prepolymer having a terminal group; And blocking the terminal isocyanate group of the crosslinked polyurethane prepolymer with a blocking agent (masking agent).

According to another preferred embodiment of the present invention, the self-healing crosslinked polyurethane golf ball cover composition may further comprise one or more additives selected from the group consisting of a pigment, an antioxidant and an inorganic filler containing an organic or metal .

According to another preferred embodiment of the present invention, the thermoplastic polyurethane used for producing the self-healing crosslinked polyurethane contained in the composition of the present invention preferably has a hardness of 40 to 70 Shore D.

According to another preferred embodiment of the present invention, the crosslinkable polyol having three or more hydroxy groups used in the production of the block polyurethane prepolymer includes trimethylolethane, trimethylolpropane, ethane-1, Ethane-1,1,2-triol, glycerol, penthane-1,2,3-triol, sorbitol, , Trihydroxycyclohexane, dipentaerythritol dipenta, 1,2,5-hexanetriol, benzene-1,2,3-triol benzene-1,2,3-triol, benzene-1,3,5-triol, benzene-1,2,4-triol, , 4-triol, 1,2,4-trihydroxybutane, 2-methylbutane-1,2,4- triol) and 3-hydroxymethylpentane-1,2,5-triol (3- (hydroxymethyl) pentane-1,2,5-triol) desirable.

According to another preferred embodiment of the present invention, the diisocyanate used in the preparation of the block polyurethane prepolymer may be an aromatic isocyanate such as diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), naphthalene diisocyanate (NDI), tolylene diisocyanate ), PPDI (p-phenylene diisocyanate), aliphatic isocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and H12MDI (4,4'-dicyclohexylmethane diisocyanate).

According to another preferred embodiment of the present invention, blocking agents (masking agents) used in the preparation of the block polyurethane prepolymer include ethylene glycol, neopentyl glycol, propylene glycol, Hexylene glycol, 1,6-hexanediol, triethylene glycol, catechol, resorcinol, hydroquinone, dimethylol, 1,6-hexanediol, Phenol (dimethylol phenol), and bisphenol (bisphenol).

The present invention relates to a process for producing a crosslinked polyurethane prepolymer by reacting a polyol having three or more hydroxyl groups with a diisocyanate, Adding a blocking agent to the crosslinked polyurethane prepolymer to prepare a crosslinked block polyurethane prepolymer having blocked isocyanate groups at the ends of the crosslinked polyurethane prepolymer; And a composition comprising the crosslinkable block polyurethane prepolymer and a thermoplastic polyurethane are mixed and placed in an extruder, and the mixture is stirred sufficiently while maintaining a temperature in the range of 180 to 220 ° C to effect exchange reaction. Self-healing crosslinked polyurethane Of the present invention.

The present invention also relates to a self-healing crosslinked polyurethane golf ball cover prepared by injection-molding a self-healing crosslinked polyurethane golf ball cover composition of the present invention and a self-healing crosslinked polyurethane golf ball cover comprising one to three Of golf balls.

The golf ball cover composition of the present invention is capable of injection molding by ensuring the flowability of urethane because crosslinking of polyurethane is broken at a high temperature of 180 ° C or more, and as a result of injection molding, problems in process of manufacturing urethane cover by conventional casting It has an effect to overcome.

In addition, the self-healing crosslinked polyurethane prepared by using the golf ball cover composition of the present invention has a good rebound resilience and is excellent in mechanical properties of the polyurethane elastomer due to the formation of cross- The performance is excellent.

Further, since the elasticity can be further controlled by mixing a part of polyamide, the present invention can exhibit the performance characteristics of a conventional double cover (urethane cover + ionomer cover) golf ball with a self-healing crosslinked polyurethane single cover There is also.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a simplified schematic diagram of a process for producing the injection self healing crosslinked polyurethane of the present invention.
Figure 2 shows the mechanism for the production of self-healing crosslinked polyurethanes.

Hereinafter, the present invention will be described in detail.

Currently, urethane covers of most golf balls are manufactured by the casting method. The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a polyurethane which can be molded by injection molding of a urethane cover. In order for the polyurethane to be injection-molded into the golf ball cover, it is necessary to secure good fluidity for the first injection and secondly, sufficient strength and durability as the golf ball cover after the injection molding.

In order to realize this, the inventors of the present invention have repeatedly conducted research, and as a result, self-healing crosslinked polyurethane was devised in a potent manner. This is because, at high temperature, a part of the urethane bonds are dissociated to secure sufficient fluidity to enable injection, and crosslinking of urethane is reversibly formed during cooling after injection to secure mechanical properties.

For this purpose, as shown in FIG. 1, a polyol monomer having three or more functional groups selected to form a crosslinking structure in a thermoplastic polyurethane (TPU) is reacted with a diisocyanate to prepare a crosslinkable prepolymer having an isocyanate group as an end. Thereafter, the isocyanate groups at the ends of the crosslinkable prepolymer are blocked with a masking agent (blocking agent) to prepare a crosslinkable block prepolymer. The cross-linked block prepolymer thus prepared is reacted with a thermoplastic polyurethane (TPU) at a high temperature continuously as shown in FIG. 2 below. At this time, the hydroxy group of the dissociated blocking agent attacks the long chain of the TPU, As shown in FIG. 2, the disrupted and deblocked isocyanate has a self-healing effect based on reversibility while being slowly cooled to room temperature, resulting in a network structure of hydroxyl groups and urethane crosslinks at the ends of long chains, And mechanical properties. Here, when the blocking agent is sufficiently dissociated by heat, the dissociated blocking agent attacks the TPU to shut off the TPU chain by the transesterification reaction to secure the fluidity, and at least 150 ° C is required for the exchange reaction to occur. In the present invention, it is possible to control the degree of crosslinking of the crosslinked polyurethane by controlling the amount of the prepolymer at the time of extrusion, and it is also preferable to add a part of polyamide at the time of extrusion for additional elasticity control.

The self-healing crosslinked polyurethane material produced in this way is not only easy to manufacture the urethane cover by the injection method but also has a greater distance when hit by the driver than the casting method in terms of the performance of the golf ball. Which is excellent in reverse rotation performance and has a soft feel and feel.

The polyurethane golf ball cover composition of the present invention is prepared by mixing and exchanging 1 to 20 parts by weight of a block polyurethane prepolymer and 0 to 10 parts by weight of polyamide with respect to 100 parts by weight of thermoplastic polyurethane (TPU) Characterized in that it comprises self-healing crosslinked polyurethane.

When the content of the block polyurethane prepolymer is less than 1 part by weight based on 100 parts by weight of the thermoplastic polyurethane, the injection moldability is lowered. On the other hand, if the content exceeds 20 parts by weight, the mechanical properties of the golf ball cover deteriorate. Also, if the content of polyamide exceeds 10 parts by weight, there is a problem that the turning force of the golf ball is lowered.

The composition of the present invention may further comprise one or more additives selected from the group consisting of a pigment, an antioxidant and an inorganic filler containing an organic or metal, in addition to the self-healing crosslinked polyurethane.

The block polyurethane prepolymer used for the self-healing crosslinked polyurethane contained in the composition of the present invention is obtained by reacting a crosslinking polyol having three or more hydroxy groups with a diisocyanate to obtain a crosslinked polyurethane having an isocyanate group as an end Preparing a prepolymer; And blocking the terminal isocyanate group of the crosslinked polyurethane prepolymer with a masking agent.

The thermoplastic polyurethane used for the production of the self-healing crosslinked polyurethane contained in the composition of the present invention preferably has a hardness in a range of 40 to 70 Shore D. If the hardness of the thermoplastic polyurethane is less than 40 Shore D, the durability of the golf ball cover becomes poor. On the contrary, if the hardness exceeds 70 Shore D, it may have a detrimental effect on the golf ball feel.

Hereinafter, a method for producing self-healing crosslinked polyurethane contained in the golf ball cover composition of the present invention will be described in detail.

The self-healing crosslinked polyurethane of the present invention comprises a step of reacting a polyol having three or more hydroxyl groups with a diisocyanate to prepare a crosslinked polyurethane prepolymer; Adding a blocking agent to the crosslinked polyurethane prepolymer to prepare a crosslinked block polyurethane prepolymer having blocked isocyanate groups at the ends of the crosslinked polyurethane prepolymer; The composition comprising the crosslinkable block prepolymer and the thermoplastic polyurethane (TPU) is mixed and extruded into an extruder, and the mixture is sufficiently stirred while maintaining the temperature in the range of 180 to 220 ° C.

First, the step of producing a crosslinkable polyurethane prepolymer will be described.

A crosslinked polyol having three or more hydroxyl groups and a diisocyanate are dissolved in a solvent at a molar ratio of 1: 2 to 1: 4 in a reactor equipped with a stirrer, a condenser, a thermometer and a nitrogen line. The type of the solvent used is not particularly limited, but in the examples of the present invention, a dried THF solvent is used. In addition, it is preferable to add a reaction catalyst for promoting the reaction, and there is no particular limitation on the type of the catalyst used, but DBTDL (dibutyltin dilaurate) is preferable. In the examples of the present invention, DBTDL was added in about 1 part by weight of diisocyanate. The reaction is carried out with stirring at a stirring speed of 200 to 300 rpm while maintaining the temperature at around 60 캜. The NCO content of the isocyanate-terminated prepolymer during the reaction is analyzed and cooled to room temperature when the content reaches the theoretical value.

Examples of the crosslinking polyol used herein include trimethylolethane, trimethylolpropane, ethane-1,1,2-triol, glycerol, pentane- Penthane-1,2,3-triol, sorbitol, trihydroxycyclohexane, dipentaerythritol dipenta, 1,2, 5-hexanetriol, benzene-1,2,3-triol, benzene-1,3,5-triol, 1,3,5-triol, benzene-1,2,4-triol, 1,2,4-trihydroxybutane, , 2-methylbutane-1,2,4-triol, and 3-hydroxymethyl pentane -1,2,5-triol) is preferable.

The diisocyanate used in the preparation of the crosslinked polyurethane prepolymer is not particularly limited, and examples of the aromatic isocyanate include diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), naphthalene diisocyanate (NDI), tolylene diisocyanate (TODI) , One or more diisocyanates selected from the group consisting of p-phenylene diisocyanate (PPDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI) and 4,4'-dicyclohexylmethane diisocyanate (H12MDI) .

Examples of the blocking agent (masking agent) used in the preparation of the crosslinked polyurethane prepolymer include ethylene glycol, neopentyl glycol, propylene glycol, hexylene glycol, But are not limited to, 1,6-hexanediol, triethylene glycol, catechol, resorcinol, hydroquinone, dimethylol phenol, bisphenol, (bisphenol) are preferable.

Next, the step of producing the crosslinkable block polyurethane prepolymer will be described.

Isosorbide was added to the polyol in a molar ratio of 1: 2 to 1: 3 to the THF solution containing the cross-linked polyurethane prepolymer prepared in the above step and was crosslinked at 60 DEG C for about 2 to 4 hours To prepare a crosslinked block polyurethane prepolymer blocked with isosorbide. As the blocking agent for the self-healing polyurethane prepolymer used herein, such as isosorbide, diols such as ethylene glycol, neopentyl glycol, propylene glycol ( propylene glycol, hexylene glycol, 1,6-hexanediol, triethylene glycol, catechol, resorcinol, hydroquinone, hydroquinone, dimethylol phenol, and bisphenol. The diol is preferably one or more selected from the group consisting of hydroquinone, dimethylol phenol, and bisphenol.

Finally, the step of completing the manufacture of self-healing crosslinked polyurethane will be described.

The block polyurethane prepolymer prepared in the above step was added in an amount of 1 to 20 parts by weight to 100 parts by weight of thermoplastic polyurethane (TPU) and 0 to 10 parts by weight of polyamide, followed by well mixing and then extruded with a pelletizer- , The temperature is maintained at 150 DEG C or higher, more preferably 180 to 220 DEG C, and the screw rotation speed is controlled within the range of 50 to 300 rpm while the mixing and exchange reaction is sufficiently carried out. After passing through the nozzle, Polyurethane is produced. The pellet-shaped self-healing crosslinked polyurethane thus produced is injection-molded into a golf ball cover. If the reaction temperature is lower than 150 ° C, the exchange reaction will not occur sufficiently.

The self-healing crosslinked polyurethane prepared as described above is prepared by mixing various additives such as a white pigment or a pigment having a different color, an antioxidant such as an antioxidant, an inorganic filler including an organic or other metal, and then passing through an extruder May be used as the material of the desired cover.

As described above, the block polyurethane prepolymer and the thermoplastic polyurethane are mixed and exchanged to produce a pellet-type self-healing crosslinked polyurethane through primary extrusion, and then various additives are mixed with the self-healing crosslinked polyurethane obtained, But it is also possible to prepare a pellet-type self-healing crosslinked polyurethane by mixing a block polyurethane prepolymer with a thermoplastic polyurethane and an additive and extruding them.

The self-healing crosslinked polyurethane material prepared as described above is suitable for manufacturing a urethane cover by an injection method rather than a conventional casting method, and is used alone or mixed with polyamide or the like, It is excellent in reverse rotation performance when hit with short irons, and has excellent controllability and durability, which can improve the performance of golfers.

The present invention will be described in more detail by way of examples and comparative examples. It should be noted, however, that the examples are for illustrative purposes only and are not intended to limit the scope of the invention.

Block polyurethane Prepolymer Manufacturing example

Trimethylolpropane and diphenylmethane diisocyanate (MDI) were dissolved in a THF solvent which was dried together at a 1: 3 molar ratio while stirring slowly, and DBTDL (dibutyl (meth) acrylate) was added as a reaction catalyst to a reactor equipped with a stirrer, a condenser, a thermometer, tin dilaurate was added to about 1 part by weight of the diisocyanate. The reaction was carried out with stirring at a stirring speed of 250 rpm while maintaining the temperature at around 60 캜. During the reaction, the NCO content of the isocyanate-terminated prepolymer was analyzed. When the content reached the theoretical value, the temperature was cooled to room temperature to prepare a polyurethane prepolymer.

Isosorbide was added to a THF solution containing a polyurethane prepolymer at a molar ratio of 1: 3 to the polyol, and the mixture was reacted at 60 DEG C for about 3 hours to prepare an isosorbide-blocked crosslinked block polyurethane prepolymer.

Example  One

10 parts by weight of the block polyurethane prepolymer of the above Production Example was mixed with 100 parts by weight of a thermoplastic polyurethane having a Shore D hardness of 45 (trade name: Desmopan 9395AU, Covestro), and the mixture was sufficiently stirred and exchanged while maintaining a temperature range of 180 ° C in an extruder After the reaction, the mixture was passed through a nozzle and cooled to prepare a pellet-type self-healing crosslinked polyurethane. To the resulting self-healing crosslinked polyurethane pellets, 3 parts by weight of a white inorganic pigment (TiO2) and 0.3 part by weight of an antioxidant (trade name: Irganox 1010, Ciba Specialty Chemicals Inc.) were added and mixed. And injection molding was performed to complete the manufacture of a chisel cover having a thickness of 0.88 mm.

The thus prepared golf ball cover was used as an outer cover, and a 1.18 mm cover made of ionomer material (trade name: Surlyn, DuPont) was applied as an inner cover, thereby forming a double cover having a cover thickness of 2.06 mm. The core was made of a polybutadiene rubber cured body and a single core having a diameter of 38.60 mm. A three-piece golf ball having a weight of 45.5 g and a diameter of 42.72 mm was manufactured in the same manner (double cover + 1 core) structure.

Example  2 to 3

A three-piece golf ball having a double cover was prepared in the same manner as in Example 1, except that the content of the golf ball cover composition was adjusted as shown in Table 1.

Example  4

The content of the golf ball cover composition was adjusted as shown in Table 1, and the self-healing crosslinked polyurethane golf ball cover was injection molded so as to have a thickness of 2.06 mm. The core was made of a polybutadiene rubber cured body and a single core having a diameter of 38.60 mm. In this manner, a three-piece golf ball having a structure of (1 cover + 1 core) and having a weight of 45.5 g and a diameter of 42.72 mm was manufactured.

Example 1 Example 2 Example 3 Example 4 Self-healing
Crosslinked polyurethane cover composition Desmopan 9395AU (1 ^* )
100 100 100 100 Block polyurethane prepolymer (2 ^* ) 10 15 20 10 PA12 (3 ^* ) - - - 10 TiO ₂ (4 ^* ) 3 3 3 3 Irganox 1010 (5 ^* ) 0.3 0.3 0.3 0.3

1 * Desmopan 9395AU

Shore D Thermoplastic polyurethane (TPU) from Covestro with a hardness of 45

2 * block polyurethane prepolymer

In the present invention, after the reaction of trimethylolpropane with MDI, a urethane prepolymer blocked with isosorbide

3 * PA12

Shore D Polyamide 12 (or Nylon 12) having a hardness of 72 and melting point of 178 to 180 ° C

4 * TiO2 (titanium oxide)

White inorganic pigments.

5 * Irganox 1010

(Trade name) of pentaerythritol-tetrakis {3- (3,5-di-tertiarybutyl-4-hydroxyphenyl) -propionate}, a kind of antioxidant and heat stabilizer manufactured by Ciba Specialty Chemicals Inc.

Comparative Example

As a comparative example, a conventional three-piece urethane golf ball having a (2 cover + 1 core) structure was selected. The outer cover of this is polyurethane molded by a casting method and the inner cover is made of Surlyn ionomer. The urethane cover was 0.88 mm, the inner ionomer cover was 1.18 mm, and the total thickness was 2.06 mm. The core in the comparative example is the same as the embodiment, and the diameter size is the same as 38.60 mm. Similarly, the comparative golf ball weight was 45.5 g and the diameter was 42.72 mm.

One. Cover surface  Hardness( Shore  D) Measurement

The hardness was measured by a test method according to German Industrial Standard DIN 53505 with a hardness measuring instrument manufactured by Zwick Company of Germany and is shown in Table 2. This indicates the hardness of the cover surface of the golf ball, and the higher the numerical value, the higher the hardness.

2. Driver distance measurement

A member of True Temper Sports Corporation is a mechanical golfer whose name is Iron Byron. It is a titanium driver with a loft angle of 10.5 degrees and a head speed of 43 m / sec. (Distance between the ball and the run) is shown in Table 2.

3. Iron spin 5 times RPM ) Measure

The same mechanical golfer as that used for measuring the driver distance was operated with a 5 iron having a loft angle of 30 degrees at a head speed of 36 m / sec. The number of revolutions per minute is shown in Table 2, which is a photograph of the rotation of the ball when shot with a golf ball.

4. Iron Spin ( RPM ) Measure

The same mechanical golfer as that used for measuring the driver distance was operated with a 9 iron having a loft angle of 45 degrees at a head speed of 30 m / sec. The number of revolutions per minute is shown in Table 2, which is a photograph of the rotation of the ball when shot with a golf ball.

5. Durability evaluation

US ADC (Automatic Design Corp.) with a golf ball shooting machine the air cannon of the product 2.54 m to a golf club head was fixed in a 2 cm thickness of the front steel plate, the golf ball 50 at a pressure 1.6 kg / cm ² of compressed air The result of the evaluation is shown in Table 2 according to the classification described below. ≪ tb >< TABLE >

◎ Only the surface of the golf ball is slightly scratched,

○ The surface of the golf ball becomes rough, the marking is broken,

△ It is deeply wound up to the cover of golf ball,

× We evaluated by cover of golf ball broken state.

6. Evaluation of hit feeling

Table 2 shows the results of evaluating the feel of the golf ball after five rounds of actual professional golfers were actually rounded. In Table 2, ◎ is very good, ○ is good, △ is average, and × is bad do.

Golf ball characteristics Example 1 Example 2 Example 3 Example 4 Comparative Example (1 core + 2 cover) (1 core + 1 cover) (1 core + 2 cover) Cover surface hardness (shore D) 47 53 55 58 48 Driver distance (yard) 235 242 240 245 230 5 Iron Spins (RPM) 5,100 5,020 4,930 4,890 4,810 9 iron spins (RPM) 7,660 7,590 7,600 7,530 7,450 durability ○ ◎ ◎ ◎ ○ Feel ○ ~ ◎ ○ ~ ◎ ○ ~ ◎ ○ ○

As shown in Table 2, the golf ball made of the injection-type self-healing crosslinked polyurethane composition according to the present invention has a longer distance when hit by the driver, and a shorter When hit with an iron, the reverse rotation performance is better and the durability is also good. In particular, when a polyamide was added to the self-healing crosslinked polyurethane of the present invention of Example 4, a single cover showed better characteristics than a conventional urethane double cover golf ball. This is because the polyamide reinforces the elasticity, so it seems that the single cover also has the reverse rotation performance, durability and excellent impact distance than the conventional double cover golf ball.

Claims (10)

Self-healing crosslinked polyurethane prepared by mixing and exchanging 1 to 20 parts by weight of block polyurethane prepolymer and 0 to 10 parts by weight of polyamide with respect to 100 parts by weight of thermoplastic polyurethane (TPU) polyurethane,
The thermoplastic polyurethane has a hardness in the range of 40 to 70 Shore D,
The block polyurethane prepolymer is produced by reacting a crosslinking polyol having three or more hydroxy groups with a diisocyanate to prepare a crosslinkable polyurethane prepolymer having an isocyanate group as an end; And blocking the terminal isocyanate group of the cross-linked polyurethane prepolymer with a blocking agent. delete The method according to claim 1,
Wherein the composition further comprises at least one additive selected from the group consisting of a pigment, an antioxidant, and an inorganic filler including an organic or metal. delete The method according to claim 1,
The crosslinkable polyol having three or more hydroxyl groups may be selected from the group consisting of trimethylolethane, trimethylolpropane, ethane-1,1,2-triol, glycerol Penthane-1,2,3-triol, sorbitol, trihydroxycyclohexane, dipentaerythritol dipenta, and the like. 1,2,5-hexanetriol, benzene-1,2,3-triol, benzene-1,3,5-tri Benzene-1,3,5-triol, benzene-1,2,4-triol, 1,2,4-trihydroxybutane (1,2, 4-trihydroxybutane, 2-methylbutane-1,2,4-triol and 3-hydroxymethylpentane-1,2,5-triol (3- (hydroxymethyl) pentane-1,2,5-triol). 10. The self-healing crosslinked polyurethane golf ball cover composition according to claim 1, The method according to claim 1,
The diisocyanate may be aromatic isocyanate such as diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), naphthalene diisocyanate (NDI), tolidine diisocyanate (TODI), p-phenylene diisocyanate (PPDI), hexamethylene diisocyanate (HDI) isophorone diisocyanate, and H12MDI (4,4'-dicyclohexylmethane diisocyanate). 2. The self-healing crosslinked polyurethane golf ball cover composition according to claim 1, The method according to claim 1,
Examples of the blocking agent include ethylene glycol, neopentyl glycol, propylene glycol, hexylene glycol, 1,6-hexanediol, triethylene glycol at least one compound selected from the group consisting of triethylene glycol, catechol, resorcinol, hydroquinone, dimethylol phenol, and bisphenol. Characterized in that it comprises a self-healing crosslinked polyurethane golf ball cover composition. Reacting a polyol having three or more hydroxyl groups with a diisocyanate in a molar ratio of 1: 2 to 1: 4 to prepare a crosslinked polyurethane prepolymer;
Adding a blocking agent to the crosslinked polyurethane prepolymer at a molar ratio of 1: 2 to 1: 3 relative to the polyol to prepare a crosslinked block polyurethane prepolymer having blocked isocyanate groups at the ends of the crosslinked polyurethane prepolymer; And
Mixing a composition comprising the crosslinkable block polyurethane prepolymer and a thermoplastic polyurethane into an extruder, and maintaining the temperature in the range of 180 to 220 ° C and stirring sufficiently to carry out an exchange reaction, thereby producing a self-healing crosslinked polyurethane Way. A self-healing crosslinked polyurethane golf ball cover prepared by injection molding the self-healing crosslinked polyurethane golf ball cover composition of any one of claims 1, 3, and 5 to 7. A self-healing crosslinked polyurethane golf ball cover of claim 9 in the form of a 1 to 3 cover.

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