KR20190047386A - Method for preparing masterbatch comprising carbon nanotube and ionomer and method for preparing golf ball containing carbon nanotube - Google Patents

Abstract

The present invention relates to a method for uniformly distributing a carbon nanotube (CNT) in a rubber composition for a golf ball core to increase durability and, more specifically, to a CNT-containing golf ball which uses a CNT/ionomer master batch and increases durability in a soft ball with low compression. According to the present invention, a method for manufacturing a CNT/ionomer masterbatch comprises an ionomer dispersion manufacturing step, a CNT insertion step, a suspension manufacturing step, and a filtering/drying step wherein the content of a CNT is 1 to 30 parts by weight with respect to 100 parts by weight of ionomer. Moreover, the content of the CNT in a CNT golf ball is 0.1 to 10 parts by weight with respect to 100 parts by weight of rubber. A cover of the CNT golf ball is made of polyurethane, ionomer, or a mixture thereof, and core rubber of the center of the CNT golf ball has a multilayer structure with two, three, or more layers.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a carbon nanotube-containing masterbatch, a carbon nanotube-containing masterbatch, and a carbon nanotube-

The present invention relates to a composition for forming a golf ball, and more particularly to a composition for forming a core in a golf ball comprising a cover and a core.

Currently used golf balls are mainly composed of polybutadiene-based cured elastomer rubber as the core. On the other hand, around the center core, a polyurethane or an ionomer resin (a polyethylene acrylic acid copolymer is used to protect the center core from a strong impact when hit by a golf club and transmit the force to the center core in the inner core completely) , Surlyn series from Dupont), and a cover made of various plastic materials covering the core.

Golf balls generally vary in compression, which represents the overall stiffness of the golf ball, depending on the degree of curing of the core rubber in the center. Compression is a numerical value of the extent to which a ball undergoes compressive deformation when a constant load is applied, as measured by a compression tester manufactured by ATTI Engineering, and has a value ranging from 0 to 200.

The compression of a golf ball is compression 200 if no compression deformation occurs, and compression 1 is reduced by 0.001 inch (0.0254 mm) of deformation. A compression deformation of 0.2 inch (5.08 mm) or more will result in compression 0.

Therefore, the higher the compression value, the harder the golf ball, and the lower the compression value, the smoother the golf ball. As a rule, golf balls are usually produced at a low compression ratio of 60 and a high compression ratio of 110.

When the golfer swings with the driver, the head speed (or swing speed) is different for each golfer. Golfers should choose the golf ball compression that matches their head speed when choosing a golf ball. In general, if the head speed is higher than 90 mph, the compression is about 95 to 105. If the head speed is about 80 to 95 mph, the compression speed is about 85 to 95. If the head speed is 80 mph or less, the compression speed is 85 or less.

This is because, if a person having a high head speed uses a ball having a low compressive strength, the ball will be excessively deformed at the time of impact, resulting in loss of power unnecessarily, resulting in loss of distance. On the contrary, if a person with a slow head speed is hit by a hard, highly compressed ball, it is difficult to transmit the force to the center of the ball sufficiently, so the loss is also seen in the flying distance.

It is important not only that the golf ball has a good distance in performance, accurate green control, and a certain amount of collision, but also a good sense of hit and feel is good for play. Therefore, an ideal golf ball is a ball that is constantly flying away with a soft feel and a good sound.

In the recent golf ball world market, several golf ball manufacturing companies are competing to release low compression golf balls. This is due to the golfer's preference for a ball-friendly feel and hitting sound in addition to the distance performance and control performance.

This golf ball market trend seems to be gaining popularity among the female golfer population which is increasing both domestically and abroad as well as the soft golf ball in the aging reality of the golfer age.

However, a soft golf ball with low compression has a weakness due to modulus of elasticity, which is more frequent than a hard ball with high compression due to repeated impact, which is a major cause of golf ball claims .

Korean Patent Application No. 2017-0010558 entitled " Composite Masterbatch for High Durability Golf Ball Core and Method for Manufacturing the Same " discloses a technique of preparing a masterbatch of CNT / rubber and applying it to a golf ball core. However, this technique involves excessive shear stress for a long time in the CNT / rubber masterbatch manufacturing process and the golf ball core compounding process applied thereto, which can not avoid the disadvantage that the carbon nanotubes are damaged greatly .

In addition, U.S. Patent No. 4,329,305, entitled " Process for regulating the particle size distribution of self-dispersing ionically crosslinked thermoplastic polymer ", discloses that an ionomer is placed in an autoclave together with water and then treated with high temperature and high pressure, An acid, and a base are added to the mixture to be granulated.

The present invention intends to enhance the durability of a golf ball using carbon nanotubes.

The present invention provides a golf ball having improved durability (impact resistance) while maintaining compression in a smooth golf ball.

According to one aspect of the present invention, there is provided a method for preparing a CNT / ionomer masterbatch powder, comprising the steps of preparing an ionomer-containing solution by dissolving an ionomer in a solvent, dispersing CNT in the ionomer- Preparing a suspension of CNT / ionomer powder by adding water, an alcohol or a mixture of water and alcohol to the ionomer-CNT-containing solution, and suspending the suspension of CNT / ionomer particles to obtain CNT / Recovering the ionomer powder, and drying the ionomer powder.

In this case, it is preferable to include 1 to 30 parts by weight of CNT relative to 100 parts by weight of the ionomer.

Wherein the ionomer is a copolymer of polyethylene-acrylic acid or polyethylene-methacrylic acid, wherein the carboxylic acid group of the acrylic acid or methacrylic acid is at least one metal selected from the group consisting of Na, Li, K, Mg and Zn Neutralized can be used.

The solvent may be at least one selected from the group consisting of ethyl ether, tetrahydrofuran (THF) acetone, methyl ethyl ketone, ethanol, methanol and isopropanol.

The CNT may be a single-walled carbon nanotube, a multi-walled carbon nanotube, or a mixture thereof.

The dispersion is preferably performed by stirring with ultrasonic treatment or ultrasonic treatment.

According to one aspect of the present invention, there is provided a golf ball manufacturing method, wherein a content of a CNT content of 0.1 to 10 parts by weight with respect to 100 parts by weight of a rubber for a golf ball core and 100 parts by weight of the rubber for a golf ball core Preparing a composition for a golf ball core by mixing the CNT / ionomer masterbatch prepared in the above CNT / ionomer master batch manufacturing method, preparing a golf ball core composition by thermoforming, injection molding or casting the golf ball core composition, And forming a cover made of polyurethane or ionomer on the golf ball core surface.

The golf ball may be a single core or a multilayer core of any of 2 to 4 layers.

The golf ball core manufactured using the carbon nanotube / ionomer mast arrangement according to the present invention can be applied to a golf ball having a low compression particularly to enhance the durability while maintaining the compression.

FIG. 1 is a schematic view showing a process of manufacturing a carbon nanotube / ionomer masterbatch powder of the present invention.
FIG. 2 is a schematic view showing a manufacturing process of a golf ball including a CNT-containing core to which a carbon nanotube / ionomer masterbatch powder is applied.
3 is a photograph of carbon nanotube (a) and ionomer (b).
4 is a photograph of the CNT / ionomer masterbatch powder prepared in Example 1. FIG.
5 is a photograph of a two-piece golf ball having a CNT-containing core manufactured by the present invention and a section thereof taken.

The present invention provides a golf ball having enhanced durability of a golf ball having a low compression. To this end, the present invention intends to apply a carbon nanotube (CNT) having excellent elasticity and strength to a golf ball core.

Until now, CNTs have not been applied in spite of their excellent properties, mainly due to the lack of technology to uniformly disperse CNTs in the matrix as well as price problems.

Conventionally, in order to apply CNT to a core of a golf ball, CNT dispersion is directly applied to rubber by using a kneader or a Banbury mixer. However, this method is time consuming and causes severe damage such as breakage and breakage of CNT during mixing process.

In order to uniformly and efficiently disperse CNTs in a rubber matrix constituting a core of a golf ball, the CNT / ionomer masterbatch is first prepared in powder form and blended with the rubber, which is a matrix of the golf ball core, to improve the durability of the golf ball We want to provide technology to strengthen.

In this way, CNT / ionomer masterbatch powder is made first and blended with rubber, so that it can be efficiently compounded without delaying the time in the conventional rubber compounding process, uniform dispersion effect of CNT can be obtained, and uniform quality can be obtained . In addition, CNTs are not scattered in the CNT rubber compounding process, so that a clean manufacturing environment can be maintained.

In the present invention, the CNTs used for preparing the CNT / ionomer master batch may be single-walled carbon nanotubes or multi-walled carbon nanotubes, MWCNT can be used. Any one of these CNTs may be used, or they may be used in combination.

In the present invention, the CNT may have a diameter of 1 to 30 nm and an aspect ratio of 100 to 1,000.

In the present invention, the CNT is mixed with an ionomer to prepare a master batch. The ionomer can be easily mixed with a rubber used as a matrix material of a core in a golf ball manufacturing process, and can be dispersed. When a master batch with a CNT is manufactured using an ionomer, The CNTs can be uniformly dispersed more easily.

The ionomer used in the preparation of the master batch may be suitably used in the present invention as long as it is generally used for a cover in the production of a golf ball. Examples of the ionomer include, but are not limited to, copolymers obtained by copolymerizing polyethylene with acrylic acid or methacrylic acid, such as Surlyn, a product of Dupont Corporation, and acrylic acid or methacrylic acid is a copolymer of acrylic acid and methacrylic acid, Can be used.

Examples of the metal include Na, Li, K, Mg, and Zn.

In the present invention, the ionomer may have different physical properties depending on the degree of neutralization of the carboxylic acid and the type of neutralizing metal such as Na, Li, K, Mg, and Zn depending on the content of acrylic acid or methacrylic acid The kind of the neutralizing metal can be selected according to the properties to be obtained and the purpose, and further, the ionomer can be used singly or in a mixture of two or more.

The CNT / ionomer masterbatch powder of the present invention may contain 1 to 30 parts by weight, preferably 5 to 20 parts by weight, of CNT per 100 parts by weight of the ionomer. The CNT / ionomer masterbatch powder provided by the present invention can more effectively disperse CNTs in the rubber due to the ionomer added to the golf ball, so that the durability can be improved by adding a small amount of CNT.

As shown in FIG. 1, the CNT / ionomer masterbatch powder may be prepared by preparing an ionomer dispersed solution, adding carbon nanotubes, preparing suspensions, filtering, and drying .

The step of preparing the ionomer dispersion solution is a step of dissolving the ionomer in a solvent. As the solvent for dispersing and dissolving the ionomer, ethers, ketones, alcohols and the like can be used. Of these solvents, ethyl ether, tetra-hydropyran (THF) and the like can be used as the solvent of the ethers. Examples of the ketones include acetone, methyl ethyl ketone and the like. Examples of the alcohols include ethanol, methanol and isopropanol . These solvents may be used singly or in combination of two or more, and it is more effective to apply heat while agitating for rapid dispersion and dissolution of the ionomer.

CNT is added to the ionomer dispersion solution. The CNT may be introduced in the form of powder, but CNT may be dispersed in the same solvent used for preparing the ionomer dispersion solution, and the CNT may be added to the ionomer dispersion solution. It is preferable to apply ultrasonic treatment after CNT is added to the solvent for more uniform dispersion of the CNTs. At this time, stirring can be performed together.

Next, the CNT / ionomer dispersion solution obtained in the above step is rapidly stirred while slowly adding water, alcohol or a mixture of water and alcohol. Whereby a suspension of the CNT / ionomer powder can be prepared. At this time, it is possible to control the size of the CNT / ionomer particles produced by controlling the addition rate and the stirring speed of water or alcohol.

Next, the CNT / ionomer master batch can be obtained by recovering and drying the CNT / ionomer powder from the suspension containing the CNT / ionomer powder obtained in the above step. The recovery of the CNT / ionomer particles can be carried out by solid-liquid separation by filtration. Although the solid-liquid separation is not particularly limited, it can be suitably used in the present invention as far as it can prevent destruction of CNT. For example, filtration such as a fryer may be mentioned.

The CNT / ionomer masterbatch can be obtained in powder form by separating the CNT / ionomer particles from the liquid component using such a screening device and drying the recovered CNT / ionomer particles.

At this time, it is preferable that the drying is carried out while maintaining the temperature at 40 ° C or less in order to prevent aggregation of CNT / ionomer particles. The drying is not particularly limited, but examples thereof include hot air drying and dry drying.

Next, a process of manufacturing a golf ball using the obtained CNT / ionomer master batch will be described. This can be performed by the method shown in FIG.

Specifically, a step of blending rubber as a matrix for forming cores in a turtle mill, adding the obtained CNT / ionomer masterbatch powder and an optional additive as described above to prepare a CNT-containing composition for forming a core, Forming a core on the core surface, and forming the cover on the core surface.

In the present invention, the carbon nanotube / ionomer masterbatch powder thus prepared is compounded with a composition of a crosslinking agent, a weight agent, an initiator, an oxidizer, and the like in a rubber for a golf ball core in a predetermined composition ratio, Can be produced.

The core of the golf ball is preferably blended with CNT / ionomer masterbatch powder so that 100 parts by weight of the rubber contains 0.1 to 10 parts by weight of CNT. If the CNT content is less than 0.1 part by weight, the durability enhancement effect can not be obtained. If the CNT content is more than 10 parts by weight, the CNT content may be too high to lower the COR of the golf ball. And may cause aggregation of CNTs. Preferably, the CNT / ionomer master batch powder is mixed such that the CNT content is 0.5 to 5 parts by weight, more preferably the CNT content is 1 to 3 parts by weight.

In the present invention, the matrix rubber may be suitably used in the present invention as long as it is generally used in golf ball manufacturing. For example, polybutadiene rubber (PBR), styrene-butadiene rubber (SBR) Nylon rubber, fluororubber, and urethane rubber. These rubbers can be used singly or in combination of two or more.

The rubber is preferably added to the rubber at a predetermined composition ratio together with a core rubber composition such as a CNT / ionomer, a crosslinking agent, a weight agent, an initiator, and an oxidative stabilizer, and compounded in a tumbling mill to aged for 1 day.

The golf ball core can be manufactured using the thus obtained CNT-containing golf ball core forming composition. The core can be obtained by molding the core using known techniques such as a thermoforming process, a cover molding (injection or casting) process, and the like.

For example, in the present invention, the core can be manufactured by applying heat and pressure to the CNT-containing core golf ball core forming composition by using a hot press machine. The core thus obtained is a cured body having elasticity, It is possible to obtain a soft golf ball with low softness and to improve the durability problem that occurs in a conventional soft golf ball.

The golf ball obtained by the CNT-containing core golf ball core forming composition according to the present invention can be used as a three-piece or four-piece golf ball by forming a double-core or triple-core as well as a two- Or a five-piece golf ball.

Specifically, the CNT / ionomer master batch of the present invention can be used to prepare a rubber core in which the center core is a single core and cover the polyurethane or ionomer cover with a single or dual coating, A two-piece or three-piece golf ball can be obtained. A CNT golf ball can be made of not just two pieces but also three or more pieces.

In addition, the golf ball surface may further include a step of buffing and polishing, a surface coating and a marking step, but a detailed description thereof will be omitted in the present invention.

Example

Hereinafter, the present invention will be described in more detail with reference to examples. The following examples are illustrative of the present invention, but the present invention is not limited thereto.

Example 1

A 2 L four-necked flask was equipped with a mechanical stirrer, a condenser and a temperature controller, and 1,000 mL of THF / isopropanol (80/20 volume%) and 200 g of pelletized Nucrel 2806 as an ionomer were charged and stirred at about 150 rpm for 6 hours .

Then, 50 g of the prepared multi-walled carbon nanotubes was added and the stirring speed was rapidly stirred at about 300 rpm to uniformly disperse the CNTs.

Water was added slowly while stirring speed was increased to prepare a suspension.

The resulting suspension was filtered in a screening apparatus, and the obtained powder was completely dried at 40 ° C or lower (room temperature) to prepare a powdered CNT / ionomer master batch.

The obtained CNT / ionomer master batch was photographed and shown in FIG.

Example 2

A CNT / ionomer master batch in powder form was prepared in the same manner as in Example 1 except that Surlyn 8150 was used as the ionomer.

The obtained CNT / ionomer masterbatch powder was visually confirmed, and was substantially the same as the result of Example 1.

Example 3

A CNT / ionomer master batch in powder form was prepared in the same manner as in Example 1 except that Surlyn 8150 and Surlyn 9150 were used as ionomers.

The obtained CNT / ionomer masterbatch powder was visually confirmed, and was substantially the same as the result of Example 1.

Example 4

The CNT / ionomer masterbatch powder obtained in Example 3 was added to 100 parts by weight of NdBR rubber so as to have a CNT content of 0, 2, 4, 6 and 8 parts by weight, and an antioxidant, a stabilizer, a filler, (When the CNT content is 0 parts by weight, CNT / ionomer masterbatch powder is not added).

Thereafter, the obtained composition was compounded in a trolling mill to prepare a composition for forming a CNT-containing core.

The CNT-containing composition for forming a core was aged at room temperature for one day.

Each CNT-containing composition for forming a core containing CNTs was cut to a size of about 40 g, placed in a thermoforming press for forming a core, maintained at 150 캜 for 10 minutes, molded, and degassed twice during molding.

The molded core was cooled at room temperature for one day and then surface-treated with a centerless grinding to obtain a core size of 39.4 mm.

A cover was formed on the CNT-containing core surface by the injection molding. The cover injection molding was carried out using an ENGEL insert 100 vertical extruder, a hot runner type mold was used for the mold, and a 332 dimple cavity was used for the cover.

At this time, the cover formed a single cover using an ionomer to produce a golf ball having a cover thickness of 1.65 mm.

The weight of the manufactured golf ball was 45.32 g and the diameter was 42.70 mm (R & A regulation: diameter> 42.67 mm, weight <45.93 g).

Compression, durability and COR measurement of golf ball

The CNT golf ball obtained in Example 4 was finished by a buffing process, a polishing process and a coating process, and the compression, durability and COR were measured.

Compression measurements were made using an ATTI Compression tester.

The durability (impact resistance) of the balls was measured using a product of ADC (Automatic Design Corp.), USA.

The durability measurement method is to measure a golf ball using a device that is mounted on a cannon and then fired toward a 2-cm-thick steel plate positioned 2.54 m in front of the pressurized air. The golf ball is measured at a speed of 175 ft / sec The golf ball was repeatedly subjected to collision tests until cracks or fractures occurred and the durability was evaluated by the number of repeated collisions up to that time. The greater the number of collisions, the better the durability of the ball.

Table 1 compares the results of compression and durability measurements of golf balls according to CNT content. The measurement results for the comparative group (golf ball without CNT, compression 60) are also shown.

CNT content 0 parts by weight 2 parts by weight 4 parts by weight 6 parts by weight 8 parts by weight Compression 62 62 62 63 64 Durability (number of collisions) 52 91 99 103 119 COR 0.815 0.811 0.804 0.800 0.796

* COR (Coefficient of restitution): The ball is hit at a velocity of 125 ft / sec against a 2-cm-thick steel plate located 2.54 m in front of it.

As can be seen from the above Table 1, it can be seen from the compression measurement that even if the CNT content is increased up to 8 parts by weight, the compression value remains unchanged. This indicates that the compression of the golf ball is closely related to the degree of crosslinking of the rubber, and the presence or absence of CNT that can not crosslink can not significantly affect the compression.

On the other hand, as a result of durability measurement, the golf ball containing no CNT showed 52 durability, which is far below the general golf ball durability quality standard (> 70). This demonstrates again the weaknesses in the durability of soft golf balls with low compression recently.

However, as the content of CNT increases, the durability is remarkably increased. Specifically, when 2 parts by weight of CNT was contained, durability was improved by 75% in comparison with the case where CNT was not included. When 4 parts by weight of CNT was included, durability was improved by 90% , The durability was improved by 103% and the durability was improved by 119% and 128%, respectively, when 8 parts by weight of CNT was included. The durability improvement of the CNT golf ball is attributed to the external shock absorbing ability of the CNT.

Therefore, it can be seen that the CNT-containing golf ball technology of the present invention is remarkably improved in durability and is not broken easily, while maintaining compression with soft hit feeling as compared with a golf ball not including CNTs.

Claims (8)

Dissolving the ionomer in a solvent to prepare an ionomer-containing solution;
Dispersing CNT in the ionomer-containing solution to prepare a solution containing an ionomer-CNT;
Preparing a suspension of CNT / ionomer powder by adding water, alcohol, or a mixture of water and alcohol to the ionomer-CNT-containing solution; And
Separating the suspension of the CNT / ionomer particles by solid-liquid separation, recovering the CNT / ionomer powder, and drying
CNT / ionomer masterbatch powder manufacturing method. The process according to claim 1, wherein the CNT / ionomer masterbatch powder comprises 1 to 30 parts by weight of CNT relative to 100 parts by weight of the ionomer. The ionomer according to claim 1, wherein the ionomer is a copolymer of polyethylene-acrylic acid or polyethylene-methacrylic acid, and the carboxylic acid group of the acrylic acid or methacrylic acid is at least one selected from the group consisting of Na, Li, K, Wherein the CNT / ionomer master batch powder is neutralized with one metal. The method of claim 1, wherein the solvent is at least one selected from the group consisting of ethyl ether, tetrahydrofuran (THF) acetone, methyl ethyl ketone, ethanol, methanol and isopropanol. The method of claim 1, wherein the CNTs are single-walled carbon nanotubes, multi-walled carbon nanotubes, or mixtures thereof. The method of claim 1, wherein the dispersion is performed by stirring with ultrasonic treatment or ultrasonic treatment. The CNT / ionomer master produced according to any one of claims 1 to 6, wherein the content of CNT content is 0.1 to 10 parts by weight with respect to 100 parts by weight of rubber for golf ball core and 100 parts by weight of rubber for golf ball core Mixing the batches to produce a composition for a golf ball core;
Preparing a golf ball core by thermoforming, injection molding or casting the composition for the golf ball core; And
Forming a cover made of polyurethane or ionomer on the surface of the golf ball core
&Lt; / RTI &gt; The golf ball manufacturing method according to claim 7, wherein the golf ball is a single core or a multi-layer core of any of 2 to 4 layers.

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