JPS6049580B2 - Method for manufacturing a flexible resin sheet having multiple pores on its surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention improves the grip of equipment such as tennis rackets and baseball putts by increasing the surface friction coefficient between the grip and the hand. The present invention relates to a method for manufacturing a flexible resin sheet having a plurality of pores on its surface that improves handleability.

When using equipment that is held in the hand, it is desirable that the grip on the equipment be secure and continuous. However, especially with sports rackets, impact forces are constantly applied and it is difficult to use the equipment for long periods of time. Grip strength is easily lost due to sweaty hands, etc.

In order to provide a good grip, molded foam grips made of plastic or rubber and containing numerous air bubbles have been developed.

Sparks is US Patent No. 360,632
In US Pat. No. 6, S2abo discloses a foamed sponge elastomer for use in grips of golf clubs, etc. Similarly, in US Pat. Regarding the U-shaped handle, it is also possible to use Kabilet (G
Avillet, in US Pat. No. 3,770,033, discloses a foamed plastic handle for impact-applying tools such as hammers. Air bubbles in these grips typically occur when the grips are molded from soft moldable materials. After the material is formed into a desired shape, it is usually cured by adding a catalyst. By adding appropriate chemicals, air bubbles are formed inside the material as it hardens. Once molding is complete, the air bubbles are incorporated into the material and foam molding is performed. The grip in the above-mentioned prior art is molded by a normal molding technique, and the amount of friction on the grip surface depends on the degree of compression of the bubbles by the user. These grips had the disadvantage that they had to be specially molded to the equipment they were used with.

Forming equipment is expensive and difficult to use by the general consumer, and the application of these grips to tool handles is available only to the manufacturer of the article. Additionally, these grips are bulky and ineffective without an unduly large diameter handle that does not utilize materials that enhance gripping performance. Additionally, friction with the user's hand relies solely on the surface of the foam material and is insufficient to maintain a secure grip. A second type of grip uses foam material as a grip reinforcing cover that does not add bulk to the handle.

An example of this type is the grip of an automobile steering wheel covered with anti-slip foam rubber disclosed by Meier in US Pat. No. 3,489,031. Other examples include Kaminste
jn) (U.S. Patent No. 4,053,676),
In order to prevent slippage, Watux paint is used as a multi-layered double-sided foam grip cover. These cover-like grip reinforcements can be made from the bubble-incorporated materials described above, but these covers are thin and flexible, making it difficult for manufacturers and consumers alike to handle the handle. To. can be covered.

Furthermore, even if these covers are attached to the handle, the diameter of the handle does not change significantly, so it is suitable for use on the handle of tennis rackets, etc., where the diameter is selected to suit the user's hand. There is. One problem with these types of grip reinforcements is that they also rely on the surface friction of the material and the external coating to increase grip friction. Another type of grip uses a molded rubber suction cup attached to a flexible sheet to serve as a cover.

Grips of this type are disclosed in Sweet U.S. Pat.
No. 2,466,502, published in US Pat. The problem with this type of grip-enhancing material is that it tends to detach if the surface it is attached to is uneven or discontinuous.The two types of suction cups mentioned above deteriorate over time. Suction power is impaired.Furthermore, both types of suction cups mentioned above have dimensions that limit the number of contacts the user can make at any given time, so if one of these cups is lost, the gripping effect is greatly reduced. .One type of friction grip with an opening is disclosed in U.S. Patent No. 3 by McCracken.
It is disclosed in the specification of No. 972528.

The grip is permanently adhered to the handle portion by dipping into a rubber-based material that later hardens into a thin adhesive film. This film is bonded directly to the handle and increases in adhesion as the user sweats, improving grip. However, it is not easy for general consumers to adhere this grip to the handle portion. This is because the grip is made from a mixture of materials specifically designed to adhere to metal baseball pads. This type of grip is therefore not suitable for application to uneven or non-metallic surfaces. The main objective of the present invention is to provide a thin, flexible material that can be easily applied to handles of hand-held tools by consumers in order to improve grip performance.
The object of the present invention is to solve the above-mentioned grip problems by providing a non-abrasive grip material.

Another object of the present invention is to provide a material that utilizes a large number of pores that function as microscopic suction cups to improve grip performance without the need for external coatings to increase surface friction.

Yet another object of the present invention is to provide a gripping material whose gripping effect is improved in the presence of moisture.

The gripping material of the present invention satisfies the above objectives.

One side of the polyurethane sheet is covered with a paper-backed water-resistant adhesive. Once the paper is removed, the sheet can be easily applied to the handle of a hand-held device using only manual pressure. The surface friction of the polyurethane sheet itself is increased by the presence of numerous pores on the sheet surface that give the sheet a rough feel and act as tiny suction cups to grip the user's hands. Since there are a large number of pores per unit area of the sheet, most of these pores are in contact with the user's hands. The presence of moisture further improves clip performance as the moisture creates a seal between the microsuction cup and the tissue of the user's hand. According to the example, this material is produced in four steps as described below.

First, a liquid polyurethane resin is mixed with the appropriate proportions of catalyst, pigment or dye and poured onto a polyethylene slab to form a sheet. Second, salt is sprinkled onto the sheet, and the resin reacts with the catalyst to harden the sheet. Third, the cured sheet is sanded to the desired thickness. This sanding exposes the salt contained, and the removal of this salt makes the surface rough and creates pores. Finally, line the sheet with adhesive. When equipment such as putts and tennis rackets are coated with this polyurethane grip material and used for a long time, the pores on the surface become filled with dust and the surface becomes smooth. However, this gripping material can be regenerated by cleaning the surface with a mild detergent or by lightly sanding with fine emery paper. This further exposes the salt-containing portion and creates new pores in place of the pores filled with foreign matter. FIG. 1 shows a cross-sectional view of a polyurethane gripping material comprised of a sheet 10, an adhesive 30, and a paper backing 40.

Preferably, the grip material is manufactured in the following four steps.

First, a large amount of polyurethane resin is mixed with a sufficient amount of catalyst and cured. Also, sufficient amounts of pigments or dyes are added so that the final product is colored in the desired color. Such urethane resins, catalysts, and pigment dyes are well known in the art and will not be discussed in detail here. Urethane resins are usually made by reacting diisocyanates or polyisocyanates with glycols or other polyols. The catalyst is usually an amine such as a tertiary amine, but metal salts can also be used. In an embodiment, an isocyanate-stopped prepolymer is mixed with a polyol and a catalyst to form a polyurethane sheet material. The amounts of dye, catalyst and resin are determined by the batch production. In the second step, the mixture from the first step is poured onto a polyethylene slab to form a sheet.

Tape is pasted around the periphery of this slab. This facilitates the subsequent work of peeling off the sheet.
It is known that polishing a slab with a polishing pad removes foreign matter, improves the finish of the sheet, and facilitates sheet peeling. Abrasives may be used to facilitate removal of foreign matter from the slab. The mixture poured onto the slab is spread evenly over the surface of the slab, including the covering tape.

Further stretching is done using a slightly softer mohair oiled roller to ensure that the product has a uniform thickness. Then sprinkle regular table salt over this mixture. The salt becomes embedded in the polyurethane material and remains there as the polyurethane resin reacts with the catalyst and hardens the mixture. This chemical reaction causes the mixture to foam (ie, air bubbles are created within the mixture), forming a region 60 containing gas bubbles in the sheet 10. This foaming slightly increases the thickness of the sheet 10 and also makes the final product spongy and elastic. This mixture is placed on a polyethylene slab for approximately 8 hours to cure sufficiently to proceed to the next step. The cured polyurethane mixture is formed into a sheet and includes a salt region 50 formed by fine granular salts under its surface and a gas region 60 formed by gas generated during the curing process. In a third step, the polyurethane material is sanded with 40 or 80 grit sandpaper while resting on the polyethylene slab to remove the top surface of the sheet.

This sanding exposes regions 50 and 60 formed of gas and salt on surface 20. Some of the salt exposed during sanding is brushed away and pores 70 are formed therein. Unremoved salt dissolves when moisture is added to the sheet 10. The sanding also removes the gas-containing region 60.
It exposes the pores formed in the film, giving a rough feel to the surface of the final product, and at the same time reducing the sheet thickness from 0.125 to 1.
．． 25? Make it. The tape is then removed from the peripheral edge of the polyethylene slab and the sheet 10 is carefully peeled off. The manufacturing of the sheet 10 is thus completed. An adhesive may be applied to the back side of the sheet 10.

At this time, the sheet 10 is placed on a flat plate with the sanded side facing down. An adhesive 30 is provided with a paper backing 40 large enough to cover the entire surface of the sheet 10. Before applying the adhesive 30, the surface of the sheet 10 is thoroughly brushed to remove foreign matter. Furthermore, the temperature is maintained at 2'C or higher to make the adhesive 30 stick. One end of the paper 40 backed adhesive 30 is hand glued to the corresponding end of the sheet 10. This is 30 parts adhesive and 1 part polyurethane sheet.
This is done to prevent air bubbles from forming in the gap between 0 and 0. After the remaining parts are evenly pasted by hand,
A roller or the like is used to roll over the adhesive 30 lined with paper 40 along the surface of the sheet 10 to ensure contact between the adhesive 30 and the sheet 10. This forms a sandwich of sheet 10, adhesive 30, and backing paper 40. After the adhesive 30 is completely pasted, the protruding portion is removed with scissors. After the polyurethane gripping material is shaped to the desired size and shape and the backing paper is removed, it is easily applied to the utensil using manual pressure. The final product is thin, flexible, spongy, with many surface pores formed by exposing on the surface regions containing salt granules and regions containing gas formed during curing of the polyurethane mixture. A sheet of foamed polyurethane with non-friction properties and adhesive backing. Since this polyurethane grip material 90 is thin and flexible, it can be attached to any substantially smooth surface even if the surface has some irregularities.

This gripping material can be easily cut with scissors to the desired size and shape, so it can be applied to tools of any surface shape, thereby eliminating bulk on the tool. The adhesive 30 backing the polyurethane sheet 10 is waterproof, thus allowing the polyurethane grip material 90 to be applied to normally damp areas such as shower stall floors.

Additionally, it can be applied using hand pressure, allowing the consumer to use it anywhere without special equipment. The spongy nature of the sheet 10 is imparted by air bubbles 60 generated within the polyurethane mixture as it cures.

This property is particularly desirable when used in equipment such as rackets and pads that are subjected to impact forces. Sheet 10 is
Acts as a shock absorber. Pores 70 and 80 on surface 20 of polyurethane grip material 90 are formed by exposing air bubble regions 60 and salt regions.

Salt region 50 is typically several times larger than bubble region 60. When the surface layer is removed with a file, pores of different sizes are created. The bubble pores 80 formed by the exposure of the bubble region 60 serve to roughen the surface feel of the sheet 10, which
This is the first method to increase the surface friction of 0. salt area 5
The pores 70 formed in the area occupied by 0 are larger and deeper than the bubble pores, but their number is small. The pores 70 function as tiny suction cups and increase the surface friction of the sheet 10. For handles that are not coated with grip material, the presence of moisture will reduce surface friction, but in this case the moisture will instead physically react with the salt pores 70 and create a seal between the pores 70 and the user's hand. Increase. This suction effect is another feature of the gripping material of the present invention, which makes it ideal for applications where moisture is present in normal use. Moreover, since there are a large number of pores 70 per unit area, a large number of pores 70 are in contact with the user's hands or feet at the same time. Therefore, even if one of the salt pores 70 is filled with foreign matter, the effect on the surface friction of the entire grip material is negligible. The non-abrasive nature of the sheet 10 also makes it suitable for use where the user's hands or feet come into contact and the presence of an abrasive surface may cause injury to the hands or feet. With continuous use, the pores 70 and 80 may become filled with foreign matter such as dust, thereby reducing the friction of the sheet 10.

In this case, the surface friction can be restored by washing the surface with a light detergent or lightly sanding it with fine sandpaper. This exposes the salt and air bubble containing regions 70 and 80 slightly below the surface of the sheet 10. FIGS. 2 and 3 show an example in which the polyurethane grip material 90 is applied to a handle portion of a hand-held tool. FIG. 2 shows a racket 100 for use on the court. FIG. 3 shows a baseball putt 300. Either arrangement can be accomplished by the manufacturer or by the consumer by wrapping a thin strip of elongated gripping material in a spiral fashion around the handles of the implements 100 and 300. The gripping material adheres to the handle itself to form a permanent grip that is water and sweat resistant and also protects the surface of the handle. If the grip material becomes worn, simply peel off the old grip material and apply a new one. What has been described above is a thin, flexible, back-adhesive grip-enhancing material that can be easily applied to the handle of a hand-held device.

This grip-enhancing material has all the friction-increasing mechanisms of conventional grip-improving materials, and also contains microscopic portions containing salt and air bubbles on its surface that, when exposed, cause the user's grip. It is designed to act as a micro suction cup hole to improve the suction. These suction pores may become filled with foreign matter, but in that case, new pores are exposed by lightly rubbing the surface of the grip material with fine sandpaper to remove the upper layer of the area.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional perspective view of a polyurethane grip material according to the present invention, FIG. 2 is a plan view of a racket using the polyurethane grip material of FIG. 1, and FIG. 3 is a baseball putt using the polyurethane grip material. There is a diagram. DESCRIPTION OF SYMBOLS 10... Sheet, 20... Sheet surface, 30... Adhesive, 40... Lining paper, 50, 60... Area, 70
, 80... Pore.

Claims (1)

[Claims] 1. A step of forming a sheet of a curable resin material, a step of scattering a granular substance onto the sheet in a soft state, a step of hardening the sheet, and a step of removing the upper surface portion of the sheet. a flexible sheet having a plurality of pores on its surface, the sheet comprising the steps of: exposing some of the granular material; and removing the exposed granular material to form a plurality of pores on the surface of the sheet. A method for manufacturing a synthetic resin material sheet. 2. The method for producing a flexible resin material sheet having a plurality of pores on the surface according to claim 1, wherein the granular material is soluble and removed by dissolving it in a solvent. 3. The method of manufacturing a flexible resin material sheet having a plurality of pores on the surface according to claim 1, wherein the resin material is polyurethane. 4. The method of manufacturing a flexible sheet having a plurality of pores on the surface according to claim 1, wherein the step of removing a part of the upper surface of the sheet is chemical removal. 5. The method of manufacturing a flexible resin sheet having a plurality of pores on the surface according to claim 1, wherein the step of removing a part of the upper surface of the sheet is performed by sanding. 6. The method of manufacturing a flexible resin sheet having a plurality of pores on its surface according to claim 2, wherein the granular material is common salt and the solvent is water.