JP2618833B2 - Injection molded shoe manufacturing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an injection-molded shoe using a water-repellent and antifouling instep cover, and in particular, a water-repellent and antifouling instep cover and a molded shoe sole. The present invention relates to a method for producing an injection-molded shoe having a strong adhesive state.

[0002]

2. Description of the Related Art When a cloth shoe is manufactured by an injection molding method, an instep cover made of a single layer or multiple layers is suspended in a last mold, and this last mold is combined with a bottom mold and a side mold, which is constructed at that time. Inject a shoe sole material consisting mainly of polyurethane into the mold cavity,
At the same time as forming the shoe sole, a method of adhering and integrating the shoe sole to the lower surface of the instep is performed.

Recently, the surface of the instep is treated with a fluorine-based water repellent such as polytetrafluoroethylene,
Uppers having water repellency and antifouling properties have been employed, and attempts have been made to add value to shoes. In this case, as the sole material, polyurethane having many advantages such as light weight, excellent appearance, good moldability and relatively low price is most often used. Although such polyurethane has excellent adhesiveness to other objects, good adhesion is obtained when an injection-molded shoe is manufactured in combination with the water-repellent / antifouling-treated upper cover as described above. I can't.

Therefore, a method of using an instep in which a solvent-based polychloroprene adhesive or a polyurethane adhesive is applied in advance with a brush or the like on the instep part which is usually adhered to an injection-molded shoe sole, or the above instep is used. There has been proposed a method of using a shell in which a thin layer of a hot-melt type polyester or polyurethane is layered on a portion.

[0005]

However, according to the former method, a plurality of brush coating operations are required, and there is a sanitary problem due to evaporation of the solvent and the like, and according to the latter method. A dedicated machine for layering a hot-melt resin at a predetermined location is required. In any case, not only does the production cost rise but also the desired adhesiveness cannot be obtained. SUMMARY OF THE INVENTION The present invention is intended to solve the drawbacks of the conventional injection-molded shoe manufacturing method.

[0006]

DISCLOSURE OF THE INVENTION The present invention is directed to an injection-molded shoe in which a shoe sole material containing polyurethane as a main component is injection-molded on the lower surface of an instep whose surface is treated with a fluorine-based water repellent to bond and integrate them. In the manufacturing method, the viscosity of the sole material made of polyurethane as a main component is 35 to 45 at a temperature measured by a Brookfield viscometer B
20 ° C at rotor No.2 and rotation speed 10 RPM
A method of making an injection-molded shoe, characterized in that it is between 0 and 1500 centipoise. Further, the polyurethane is a polyether type.

In the practice of the present invention, if the viscosity of the sole material containing polyurethane as a main component measured in accordance with the above conditions exceeds 1500 centipoise, the effect of anchoring to the lower surface of the upper decreases, and the sole and upper of the shoe lower. Sufficient adhesion to the lower surface cannot be obtained, while if it is less than 200 centipoise, elasticity is insufficient after molding and curing to form a shoe sole, and it does not function as a shoe sole on physical properties and footwear. .

[0008] Here, among the instep covering materials, those having a narrow gap between the textures and having poor adhesion such as polyamide fiber and polyester fiber preferably have a viscosity close to 200 centipoise, and have a wide gap between the textures. For materials with good adhesive properties, such as natural fibers, it may be close to 1500 centipoise. As the sole material, an injection molding method is used, and therefore, a prepolymer method that can easily control a curing reaction is used.

This is a polyol side premix (liquid A) in which a polyol, a chain extender, a foaming agent (water), a foam stabilizer, a catalyst, a pigment and the like are mixed, and an isocyanate obtained by partially modifying methylene diisocyanate with the polyol. It usually consists of two liquids of the side component (liquid B). The polyol used for the liquid A side is generally a polypropylene glycol system, and the chain extender is a monomolecular glycol. The catalyst is necessary to adjust the balance between foaming and gelling of the A and B mixture stock solution, so that the cream time can be adjusted, the anchoring effect on the woven cloth etc. on the lower surface of the upper can be adjusted, and the mold release time can also be adjusted. it can. Tertiary amines are often used for this purpose.

The liquid B is an isocyanate-terminated prepolymer using an excess of methylene diisocyanate, and a large amount of free methylene isocyanate is present in this prepolymer, which is crystallized at a low temperature. As the polyol, a polyether type hardly hydrolyzed even after a molded and hardened shoe sole has been used for a long time is used.

As the fluorine-based water repellent, desperate such as polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, polyvinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene / vinylidene fluoride copolymer, etc. John and emulsion are used, and as the cross-linking agent, diamide compounds, melamine compounds, and isocyanate compounds are used, but melamine compounds with little discoloration are most often used. The fluorine-based compound imparts water repellency and antifouling properties by forming a protective film around the fibers in a molecule-shaped shield.

[0012]

According to the present invention, at the temperature (35 to 40 ° C.) during the injection molding as the sole material, the viscosity is such that it easily permeates between the textures of the woven fabric constituting the upper, that is, anchors easily. Since the obtained polyurethane is used, shoes with a sole with sufficient adhesion to the water-repellent and antifouling upper that has been treated with a fluorine-based water-repellent material by ordinary injection molding operations. Obtainable.

[0013]

[Example] The organization is (10/2 × 10/2) / (45 × 3
4) The cotton plain weave fabric is used as the upper fabric of the upper. A fluorine-based water repellent comprising 4 parts by weight of an emulsion made of polytetrafluoroethylene (manufactured by DuPont, Teflon (registered trademark)), 0.2 part by weight of a melamine-based crosslinking agent, and 100 parts by weight of water Dipped in the rubber roll, squeezed through rubber rolls and dried with hot air at 120-140 ° C.
It was cured at 90 ° C. for 3 to 10 minutes, further washed with water to remove the unreacted crosslinking agent, and dried.

A water-repellent and antifouling treated surface cloth was prepared as described above, a polyester fiber knitted cloth was used as a backing cloth, and a solvent-based adhesive made of natural rubber was used as a laminated instep material. After this was cut and sewn, it was sewn to the insole cloth to obtain a bag-shaped upper cover generally called a California upper cover. This upper was suspended in a last mold, and combined with the side mold and the bottom mold, a cavity for forming a shoe sole was formed. In this cavity, 100 parts by weight of polyether polyol, 1.1 parts by weight of triethylenediamine, 6 parts by weight of titanium oxide, 0.3 part by weight of water, and a liquid A of 35 to 40 ° C., 40 to 4
Mixture A consisting of 2 liquids with polyisocyanate B liquid at 5 ° C
Liquid B (Rotor NO.B by Brookfield viscometer type B)
2. Viscosity measured at 10 RPM was 1000 centipoise) and injection-filled to form a shoe sole, and at the same time, the shoe sole was adhered to the lower surface of the instep.

As a comparative example, a polyurethane adhesive (Euroc 6250, manufactured by Hirono Chemical Co., Ltd., solid content: 20%) was applied by a brush to the surface of the upper obtained above, which was bonded to the shoe sole. After drying for 15 minutes, liquid polyurethane having a viscosity of 2000 centipoise according to the above-mentioned measurement method is used as a sole material.
Shoes were made by injection molding. A sample with a width of 10 mm was taken from the joint between the sole and the instep from both shoes, and a peeling test was performed with a Shopper type tensile tester under the conditions of an opening angle of 180 ° C and a speed of 50 mm / min. I got the result.

The shoes of the present invention The shoes of the comparative example Adhesion when dry (kg / cm) 4.0 1.8 Adhesion when wet (kg / cm) 3.8 1.5

[0017]

[Effect] Adhesion between the instep and the sole even if the shoe uses a polyurethane insole that is water-repellent and stain-proof with a fluorine-based water repellent and uses polyurethane as the sole material by injection molding. I got good shoes.

Claims (2)

(57) [Claims] 1. A shoe sole comprising polyurethane as a main component,
In a method of manufacturing an injection-molded shoe in which the surface is treated with a fluorine-based water repellent on the lower surface of the instep by injection molding, the viscosity of the sole material made of polyurethane as a main component is the temperature of 35 with a Brookfield viscometer B A method for producing injection-molded shoes, characterized in that it is 200 to 1500 centipoise when measured at ~ 45 ° C, rotor No. 2, and rotation speed of 10 RPM. 2. The method of injection molding according to claim 1, wherein the polyurethane is a polyether type.