JPH09117304A - Manufacture of shoe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an adhesive property between a polyurethane sole and a cloth piece by placing an antislipping piece on a prescribed position of a shoe sole forming base mold by setting a moisture nonabsorptive synthetic fiber-made cloth piece surface as an upper surface, combining it with the last mold coated with an instep skin, injecting liquid polyurethane into a cavity, and foaming and hardening it. SOLUTION: A layered body is formed by adhering one surface of an unvulcanized rubber sheet 1 to the raising surface side of a moisture nonabsorptive synthetic fiber-made cloth piece 2 through an adhesive 3. This layered body is put in a mold, and is pressurized and molded at the normal termperature, and the molding body is put in a vulcanizing can, and is heated and vulcanized, and is cut in a prescribed shape. This cut antislipping piece 4 is placed on a prescribed position of a shoe sole forming base mold 8 by setting a surface of the moisture nonabsorptive synthetic fiber-made cloth piece 4 as an upper surface, and is combined with the last mold coated with an instep skin, and liquid polyurethane is injected into a cavity formed at that time, and is foamed and hardened. Therefore, an adhesive property between the polurethane sole 6 and the synthetic fiber-made cloth piece 4 can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a shoe having a two-layer sole in which a rubber anti-slip is arranged on a part or the whole of the ground contact surface of a polyurethane sole.

[0002]

2. Description of the Related Art Generally, polyurethane is lightweight, elastic, and has excellent abrasion resistance, while vulcanized rubber has excellent anti-slip properties. A shoe having a two-layer sole in which anti-slip pieces made of vulcanized rubber are attached to the sole has been developed and is widely used in the fields of sports shoes, casual shoes, business shoes and the like.

However, since the adhesion between polyurethane and vulcanized rubber is poor, there is a problem that durability is poor,
As a method to improve the adhesion between polyurethane and vulcanized rubber, buff the adhesive surface side of the vulcanized anti-slip piece, then chlorinate the surface, and then apply polyurethane adhesive etc., then shoes A complicated method of placing the base mold at a predetermined position on the bottom forming base mold and injecting the liquid polyurethane is used.

In order to simplify the above steps, a cloth such as a woven cloth, a non-woven cloth, and a knitted cloth is placed on one surface of an unvulcanized rubber piece, and then press-vulcanized at a predetermined temperature to vulcanize the cloth. There is also adopted a method of forming a slip-proof piece which is pressure-bonded, and then mounting it on a shoe sole mold and injecting liquid polyurethane to bond the shoe sole made of polyurethane and the rubber-made slip-proof piece through a cloth.

[0005]

The method of joining the shoe sole made of polyurethane and the anti-slip piece made of rubber through the cloth has the following problems. In the method of placing the cloth on the unvulcanized rubber piece and molding the anti-slip piece by press vulcanization, the vulcanization temperature is 140 to 1
Since it is molded under the conditions of 80 ° C and a pressing pressure of 50 to 200 kgf / cm ² , the unvulcanized rubber material leaks from the voids of the cloth to the surface, and the surface of the cloth is covered with the vulcanized rubber layer to prevent slipping. After being placed on a base mold and injecting liquid polyurethane, the adhesive strength between the polyurethane bottom and the fabric surface of the anti-slip piece was reduced, and the anti-slip piece might peel off.

Further, in the above method, a difference in heat shrinkage between the cloth and the rubber is generated, and the anti-slip pieces are deformed after molding.
In some cases, when the anti-slip piece was placed on the base mold and liquid polyurethane was injected, a gap was created between the anti-slip piece and the base mold, and the liquid polyurethane flowed into the design portion of the anti-slip piece, impairing the appearance.

Next, when the material of the cloth to be laminated with the unvulcanized rubber piece is a hygroscopic cloth such as cotton or rayon,
In order to absorb moisture in the air, when injecting liquid polyurethane into the fabric surface of the anti-slip piece, the liquid polyurethane abnormally foams on the fabric surface due to the water content of the fabric, causing a decrease in strength, and after the liquid polyurethane foams and hardens, There was a risk that the adhesive strength with the fabric would be reduced.

In order to improve the adhesive force between the unvulcanized rubber piece and the cloth, an adhesive such as NR latex may be applied to the surface of the cloth that contacts the unvulcanized rubber piece. May easily leak to the back side of the coated surface, and when liquid polyurethane is cast on the cloth surface where the adhesive has leaked, the adhesive strength between the cloth surface and the polyurethane may decrease.

As described above, in the method of placing the cloth on the unvulcanized rubber piece, press-vulcanizing it, and molding the anti-slip piece, the steps are simplified, but when the liquid polyurethane is injected, the cloth of the anti-slip piece is formed. There are problems such as a decrease in adhesion to the surface and a poor appearance due to deformation of the anti-slip pieces. The present invention solves the above problems all at once, and provides an inexpensive method for manufacturing shoes, which simplifies the process.

[0010]

[Means for Solving the Problems] One surface of an unvulcanized rubber sheet and a raised surface side of a non-hygroscopic synthetic fiber cloth are made into a laminated body with an adhesive, and the laminated body is put in a mold at room temperature. After pressurizing and molding with, put this molded product in a vulcanizing can, heat and vulcanize it, cut it into a predetermined shape, and form the shoe sole with the non-hygroscopic synthetic fiber cloth surface as the upper surface The first feature of the present invention is to place it on a predetermined position of the base mold for use in combination with the last mold with the instep covering, inject the liquid polyurethane into the cavity formed at that time, and foam and cure it.

The non-hygroscopic cloth has a water content of JIS
The value measured by L1003 is temperature 20 ℃, relative humidity 9
The second feature is that 5% does not exceed 10%.

The adhesive applied to the raised surface of the non-hygroscopic fabric is composed of two layers of adhesives having different components, and the two-layer laminate is modified with a polychloroprene adhesive in order from the raised surface. A third feature is that the structure is such that a natural rubber adhesive is applied.

A fourth feature of the mold for pressurizing and molding the laminate at room temperature is that a concave and convex design is provided on the bottom surface of the cavity so as to form an anti-slip design.

A fifth feature is that the heating medium in the vulcanizer is hot air or direct steam.

A sixth feature is that the cut anti-slip piece is placed on a part or the whole surface of the bottom of the base mold.

A seventh feature is that the non-hygroscopic fabric is a knitted fabric and has a wale number of 30 to 45 / inch and a course number of 30 to 90 / inch.

The polyurethane used in the present invention comprises an organic diisocyanate component and a polyol component as main components, and optionally a chain extender, a catalyst, water as a foaming agent,
It is a product produced by the addition of pigments and surfactants.

The rubber used in the present invention is usually used for shoe soles and includes natural rubber, styrene-butadiene copolymer rubber (SBR), polyisoprene rubber (I
R), polybutadiene rubber (BR), acrylonitrile-butadiene copolymer rubber (NBR), and other unvulcanized rubbers made of natural rubber or synthetic rubber.

The unvulcanized rubber includes fillers such as ordinary calcium carbonate, silane-treated or surface-treated with fatty acid, calcium carbonate or magnesium carbonate, hydrous silicates such as hydrous aluminum silicate, titanium dioxide, zinc oxide and the like. ，
A cross-linking agent, other antioxidants, softening agents, pigments, etc. are appropriately blended as necessary. Furthermore, in the above-mentioned unvulcanized rubber,
The incorporation of hard fibers such as glass fibers, aramid fibers, and carbon fibers is preferable because slip resistance is improved.

The cloth used in the present invention includes woven fabrics, knitted fabrics,
Fabrics such as non-woven fabrics, whose material is synthetic fiber,
The moisture content measured by the SL1003 method is 20 ° C,
It is necessary that the relative humidity does not exceed 10% at 95%, and any one of synthetic fibers such as polyamide, polyester, polyacrylonitrile, polyvinyl chloride and polyurethane is selected.

[0021] Cotton, rayon, acetate, whose water content measured by the above-mentioned measuring method exceeds 10%,
When a cloth made of a material such as polyvinyl alcohol is used for the cloth laminated with the anti-slip pieces, the following problems occur. When the anti-slip pieces are placed on the base mold, liquid polyurethane is injected, and foam curing is performed, if the environmental conditions exceed 80% of the related humidity, the liquid polyurethane will be abnormally foamed on the surface of the fabric due to the influence of moisture absorbed by the fabric. The decrease in the strength of the polyurethane decreases the adhesion strength between the cloth and the polyurethane.

It is necessary that at least one side of the non-hygroscopic fabric is raised, and if both sides are raised, the adhesiveness between the liquid polyurethane and the fabric is improved, which is more preferable. Two kinds of adhesives having different components are sequentially applied to the raised surface of the cloth. The first layer is coated with a polychloroprene-based adhesive and has excellent adhesiveness with synthetic fibers. The second layer is coated with a modified natural rubber adhesive, which has good compatibility with the polychloroprene adhesive of the first layer and good adhesion with unvulcanized rubber. Strengthens adhesion with anti-slip pieces.

When a knitted fabric is used as the non-hygroscopic fabric, the modified natural rubber adhesive is a latex in order to prevent leakage during application of the adhesive and leakage of unvulcanized rubber fabric during pressing. And any one of an acrylic graft body, a styrene graft body, and a styrene acrylic graft body whose main component is natural rubber is selected. The above latex has a solid content of 3
The viscosity is 0 to 60%, the viscosity is 20 ° C. using a Brookfield viscometer, and the number of rotations is 1 using a rotor No. 7.
The value measured at 0 RPM is 700-1200 poise.

The adhesive is applied to the cloth by a spreader, and the polychloroprene adhesive in the first layer is 100 to 15 in dry weight in order to secure the adhesiveness.
A coating weight of 0 g / m ² , the modified natural rubber adhesive of the second layer is applied in a dry weight of 50 to 100 g / m ² .

Further, an unvulcanized rubber sheet and a cloth coated with the above-mentioned adhesive are laminated to form a laminated body, and this laminated body is placed in a mold engraved with a non-slip design with the rubber surface facing down and kept at room temperature. Press to design the laminate. The pressing pressure at this time varies depending on the thickness of the laminate and the design depth, but is 10 to 100 kgf / cm ^2, preferably 30 to 50 kg.
f / cm ² is good.

Next, the laminate having the anti-slip design is vulcanized by hot air vulcanization or direct steam vulcanization in a vulcanizing can. The vulcanization temperature is 110 ° C. to 140 ° C., preferably around 130 ° C., in order to prevent deformation caused by the difference in heat shrinkage between the laminated fabric and the unvulcanized rubber. The vulcanized laminate is cut into a predetermined shape and placed on a shoe sole forming mold as an anti-slip piece and integrally molded with the polyurethane sole. A part of the bottom portion, for example, a tread portion and a heel portion It may be mounted on the bottom surface or on the entire bottom surface.

[0027]

The non-hygroscopic synthetic fiber cloth is used to bond the anti-slip pieces to the polyurethane bottom, so that they are not affected by hydrolysis, which is a drawback of conventional polyurethane adhesives, The adhesive strength does not decrease. Since the fabric on the anti-slip piece side of the fabric of the anti-slip piece is raised, it adheres well to the adhesive and at the same time when the adhesive is applied, leakage to the back surface of the fabric can be prevented.

Further, since the material of the cloth is the non-hygroscopic synthetic fiber, when the liquid polyurethane is injected into the cloth surface of the anti-slip piece and the foam is cured, the liquid polyurethane is affected by the water content of the cloth. The abnormal foaming can be prevented, and the adhesion between the polyurethane bottom and the fabric is stabilized.

Next, the laminated body in which the cloth and the unvulcanized rubber sheet are bonded together is put into a mold, pressed and molded at room temperature, and vulcanized by hot air or direct steam in a vulcanizing can. It is possible to prevent the unvulcanized rubber from leaking to the surface of the cloth, and there is no deformation of the anti-slip pieces after vulcanization. As described above, the anti-slip piece can be molded without deformation, and the adhesive force between the polyurethane sole and the anti-slip piece does not decrease during shoe molding, so it has excellent appearance and durable anti-slip properties. Shoes can be manufactured.

[0030]

The present invention will be described below in detail with reference to examples. (1) Cloth The cloth used in the examples is a knitted cloth made of polyester filament and fluffed on one side.
1 / inch, the number of courses is 52 / inch, and the denier of the system is 75 denier for the front and 20 denier for the back. The moisture content measured by JIS L1003 was 0.7% at a temperature of 20 ° C. and a relative humidity of 95%.

(2) Adhesion of cloth onto the cloth The cloth is placed in a spreader sizing machine with the raised surface in the original state, and the solvent is made of polychloroprene (solid content 50%, viscosity 1000 poise, Brookfield viscometer temperature 20 ℃, rotor No.7, rotation speed 10RPM
Measured value at 130-140 g / m ³
Coating, drying and winding, and again using a spreader gluing machine, styrene-acryl grafted natural rubber latex (solid content 50
%, Viscosity 1200 poise, Brookfield viscometer temperature 20 ° C., rotor No. 7, measured value at rotation speed 10 RPM) so that the coating amount becomes 70-80 g / m ^{3 in} dry weight, and after drying, A fabric having an adhesive laminated thereon was obtained.

(3) Preparation of anti-slip sheet An unvulcanized rubber fabric is rolled into a sheet having a thickness of 4.0 mm, cut into a predetermined size, and the sized cloth is approximately the same size as the unvulcanized rubber fabric sheet. And then apply a dilution liquid prepared by diluting a rubber paste with a solvent onto the adhesive surface of the cut unvulcanized rubber sheet, and then laminating the cloth onto the adhesive solution so that the adhesive application surfaces overlap each other. And Next, the laminate is placed on a base mold having a depth of 2 mm engraved with an anti-slip design so that the fabric surface is on top, combined with an upper die, and pressed at room temperature with a pressing pressure of 30 kgf / cm ² , The rubber surface was designed, and the gluing surface of the cloth and the unvulcanized rubber sheet were brought into close contact with each other via rubber glue.

(4) Preparation of Anti-Slip Pieces The laminate was placed on an iron plate and placed in a vulcanization can at a vulcanization temperature of 1
Hot air vulcanization was performed at 30 ° C. and an air pressure of 2.0 kgf / cm ² for 60 minutes, and after cooling, this was cut into a predetermined shape to prepare a slip-proof piece.

(5) Shoe-making shoe: Anti-slip pieces are set on the base mold with the cloth facing up, and liquid polyurethane is injected into the cavity formed by combining the last mold and the side mold in which the cover is suspended, and foamed and hardened. The shoe was molded.

The thus-formed shoe has a high adhesion strength between the polyurethane sole and the anti-slip piece, 5.0 kgf / cm between the cloth and the polyurethane bottom, and 3.5 kg between the cloth and the rubber.
f / cm.

[0036]

[Comparative Example 1] As a comparative example, a cotton cloth having a hygroscopic property is used as a comparative example, a slip prevention piece is produced in the same steps as in Examples (2) to (4), and this piece is set in a base mold. Liquid polyurethane was injection injected to mold shoes. The moisture content of the cotton cloth was measured by JIS L1003, and the temperature was 2
It was 25% at 0 ° C and a relative humidity of 95%. The room temperature during molding of the shoe was 20 ° C., and the relative humidity was 80%. The adhesive strength between the polyurethane bottom and the anti-slip piece of the shoe molded in this way is as low as 0.8 kgf / cm between the cloth and the polyurethane bottom, and the peeled state is the interface of the cloth, and the polyurethane has abnormal foaming. Was.

[0037]

[Comparative Example 2] Next, the same cloth as that of the embodiment was used, and the cloth was glued in the same manner as in the embodiment, and cut into a predetermined size.
As shown in FIG. 4, an unvulcanized rubber piece having the same composition as that in the example was inserted into the lower mold, and the cut fabric was placed on the piece so that the glued surface faced downward. At a temperature of 170 ° C., a press pressure of 110 kgf / cm ^{2 was applied} for press vulcanization for 5 minutes to prepare an anti-slip sheet. This anti-slip sheet was cut into a predetermined shape to obtain an anti-slip piece. This anti-slip piece was set in a base mold in the same manner as in the example, liquid polyurethane was injected, and foaming and curing were performed to form a shoe.

Since the anti-slip piece was deformed in the shoe molded in this way, liquid polyurethane partly flowed into the design surface of the anti-slip piece, and the appearance was unattractive. Further, the adhesive strength between the polyurethane bottom and the anti-slip piece was lowered to 1.2 kgf / cm between the cloth and the polyurethane bottom, and the vulcanized rubber leaked to the cloth surface.

[0039]

As described above, according to the present invention, the non-hygroscopic synthetic fiber cloth has a raised surface side and one surface of the unvulcanized rubber sheet as a laminate with an adhesive, and the laminate is used as a mold. Put it under pressure and mold at room temperature, give a rubber surface a non-slip design, put this molded product in a vulcanization can, heat and vulcanize it, form anti-slip pieces, and then place it on the base mold for forming the sole of the shoe. It is placed and combined with a last mold coated with a cover, liquid polyurethane is injected into the cavity formed at that time, and foamed and cured, so that the adhesion between the polyurethane bottom and the fabric can be improved. Furthermore, since the anti-slip pieces also have no deformation after vulcanization, it is possible to manufacture a shoe sole having an excellent external appearance and anti-slip properties.

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part for explaining a method for manufacturing a shoe according to the present invention.

FIG. 2 is a cross-sectional view of a laminated body provided with a design according to the present invention.

FIG. 3 is a bottom view of a shoe sole manufactured according to the present invention.

FIG. 4 is a cross-sectional view for explaining a conventional method for molding an anti-slip piece.

[Explanation of symbols]

 1 Unvulcanized rubber 2 Fabric 3 Adhesive 4 Anti-slip piece 5 Cover 6 Polyurethane bottom 7 Vulcanized rubber 8 Base mold 9 Last mold 10 Side mold

Claims (7)

[Claims] 1. A laminate of one surface of an unvulcanized rubber sheet and a raised surface side of a non-hygroscopic synthetic fiber cloth with an adhesive, and the laminate is placed in a mold and pressed at room temperature. After molding, the molded body is placed in a vulcanizing can, heated and vulcanized, and cut into a predetermined shape, and the cut anti-slip piece is used as a base mold for shoe sole formation with the non-hygroscopic synthetic fiber cloth surface as the upper surface. A method of manufacturing a shoe, which comprises placing it at a predetermined position, combining it with a last mold having an upper cover, injecting liquid polyurethane into the cavity formed at that time, and foaming and curing it. 2. The non-hygroscopic fabric has a water content of JI
The value measured by SL1003 is temperature 20 ℃, relative humidity 9
The method for manufacturing shoes according to claim 1, wherein 5% does not exceed 10%. 3. The adhesive applied to the raised surface of the non-hygroscopic cloth is composed of two layers of adhesives having different components, and the two-layer laminate is modified with a polychloroprene-based adhesive in order from the raised surface. The method for manufacturing shoes according to claim 1, wherein the natural rubber adhesive is applied. 4. The method for manufacturing shoes according to claim 1, wherein the mold for pressurizing and molding the laminated body at room temperature is provided with a concavo-convex design for forming a slip-resistant design on the bottom surface of the cavity. . 5. The method according to claim 1, wherein the heating medium in the vulcanization can is hot air or direct steam. 6. The shoe manufacturing method according to claim 1, wherein the cut anti-slip piece is placed on a part or the whole surface of the bottom of the base mold. 7. The method for manufacturing a shoe according to claim 1, wherein the non-hygroscopic fabric is a knitted fabric and has a wale number of 30 to 45 / inch and a course number of 30 to 90 / inch.