JPH07314581A - Manufacture of injection-molded shoe - Google Patents

Abstract

PURPOSE:To obtain a shoe, the adhesion of the sole of which even to the instep covering material treated with fluorine-based water repellent is excellent, by a method wherein the viscosity of sole material mainly made of polyurethane is specified. CONSTITUTION:The viscosity of sole materials mainly made of polyurethane is 200-1,500 centipoise measured with the B type Brookfield viscometer at 35-45 deg.C with No.2 rotor at 10rpm. As a result, at the temperature kept during the injection molding of the sole material, the material easily infiltrated among the interslices of woven cloth, which form the instep covering. Or, since the polyurethane, in which easily anchoring viscosity can be obtained, is used, a shoe having enough adhesion between a sole and even an instep covering having water repellency and stainproofness by being treated with fluorine-based water repellent can be obtained by ordinary injection molding operation.

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 of manufacturing an injection-molded shoe that has 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,
Instep coats with water repellency and stain resistance have been adopted, and attempts have been made to add added value to shoes. In this case, polyurethane is most often used as a sole material because it has many advantages such as light weight, excellent appearance, good moldability, and relatively low price. Although such polyurethane has excellent adhesion to other objects, good adhesion is obtained when an injection-molded shoe is manufactured in combination with the water-repellent and antifouling instep 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 an instep in which a thin layer of hot-melt polyester or polyurethane is overlaid 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. The actual situation is that a special machine for layering the hot-melt type resin on a predetermined place is required, and in any case, not only the manufacturing cost is increased, 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 at a temperature of 35 to 45 measured by a Brookfield viscometer B type.
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 carrying out the present invention, if the viscosity of the sole material containing polyurethane as the main component is more than 1500 centipoise when measured according to the above-mentioned conditions, the anchoring effect on the lower surface of the instep is reduced, and the sole and the instep are reduced. Sufficient adhesion with the lower surface cannot be obtained. On the other hand, if it is less than 200 centipoise, elasticity is insufficient after it is molded and cured into a shoe sole, and it does not serve as a sole in terms of physical properties and wearing. .

Among the instep materials, those having a narrow weave and poor adhesiveness such as polyamide fiber and polyester fiber preferably have a viscosity close to 200 centipoise and a wide weave. It may be close to 1500 centipoise for a good adhesive such as natural fiber. As the shoe sole material, the prepolymer method is used because its molding reaction is easy to control because its molding is an injection molding method.

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 type, and the chain extender is a monomolecular glycol. The catalyst is necessary to adjust the balance between the foaming and gelling of the A and B mixed solution stock solution, the cream time can be adjusted, the anchoring effect on the fabric on the lower surface of the instep 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 is used, which does not easily hydrolyze the molded and cured shoe sole for a long period of time.

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

[0012]

In the present invention, at the temperature (35 to 40 ° C.) during injection molding as a shoe sole material, the viscosity is such that it easily penetrates between the textures of the woven fabric constituting the instep, that is, it is anchored. Since the obtained polyurethane is used, a shoe with a shoe sole with sufficient adhesive force to a water-repellent and stain-resistant instep treated with a fluorine-based water-repellent material by a normal injection molding operation. Obtainable.

[0013]

Example: The structure is (10/2 × 10/2) / (45 × 3)
Use the cotton plain weave cloth of 4) as the outer cloth for the instep. This surface cloth is a fluorine-based water repellent consisting of 4 parts by weight of an emulsion of polytetrafluoroethylene (manufactured by DuPont, fiber protection agent Teflon (registered trademark)), 0.2 part by weight of a melamine-based crosslinking agent, and 100 parts by weight of water. It is dipped in the inside, passed through a rubber roll and squeezed to dry with hot air of 120 to 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 instep was suspended in the last mold to form a shoe sole forming cavity in combination with the side mold and the bottom mold. 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. 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 (manufactured by Hirono Chemical Co., Ltd., ULOCK 6250, solid content 20%) was applied to the surface of the instep covered with the shoe sole with a brush, at room temperature. 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.

Shoes of the present invention Shoes of Comparative Examples Adhesive strength when dry (kg / cm) 4.0 1.8 Adhesive strength 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)

[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 an injection-molded shoe, which is characterized in that it is 200 to 1500 centipoise as measured at a rotor temperature of 45 rpm, a rotor number of 2, and a rotation speed of 10 RPM. 2. The method of injection molding according to claim 1, wherein the polyurethane is a polyether type.