JPH08290492A - Manufacture of injection molded shoes - Google Patents

Abstract

PURPOSE: To provide a manufacturing method for injection molded shoes in which a sole material composed of a vinyl chloride resin as a main component and an upper covering material composed of a raised fabric are used and the upper covering material can be bonded firmly with the sole material while the hand of the upper covering material can be kept as an original hand. CONSTITUTION: A raised fabric is immersed into a water solution of an aqueous urethane emulsion composed of a non-yellowing type polyester urethane resin having ionic properties and dried to manufacture an upper covering material, which is used as a surface cloth for an upper cover, while a sole material composed of a polyvinyl chloride as a main component is injection molded, and the upper cover is bonded integrally with the sole material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an injection-molded shoe using a shoe sole material containing polyvinyl chloride as a main component.

[0002]

2. Description of the Related Art When a shoe is manufactured by injection molding a shoe sole material containing polyvinyl chloride as a main component, an organic solvent solution of polyurethane elastomer or a small amount of polyisocyanate is added to the surface of the instep material. A method of applying the added organic solvent solution with a coater having a gravure roll or a doctor knife and performing an adhesion treatment is practiced.

[0003]

When a cotton cloth plain woven fabric is used as the instep material in the above manufacturing method, the texture and the appearance of the instep material do not change so much before and after the bonding treatment, and there is no problem in the product. .

However, in the case where the instep material is a raised fabric such as kohl heaven, velveteen, etc., when treated with a diluting solution of a polyurethane resin in an organic solvent, it penetrates into the base material and swells too much and the wetting is too good. The texture was harder and the softness was lost. Also, in the case of coated fabric with ridges on the surface such as Cole sky, when coating with a coater having a gravure roll or a doctor knife, uneven coating of the treatment liquid occurs and the commercial value is greatly reduced in appearance, making it impractical. It was

Next, when the raised fabric was used as an instep cover without an adhesive treatment, the adhesive strength with the bottom material was low and the durability was not practical. In addition, in the process of bonding the instep material,
Toluene, methyl ethyl ketone, N, N contained in processing agents
-Since organic solvents such as dimethylformamide scatter and deteriorate the working environment, it is necessary to install a local exhaust system.
It was necessary to take various measures for other hygiene management aspects. The present invention aims to solve all the drawbacks of the conventional methods.

[0006]

The present invention provides (a) an aliphatic polyester polyol, (b) an organic diamine, (c) an aliphatic diisocyanate or an alicyclic diisocyanate,
(D) Water is added to a hydrophilic polyurethane resin composed of a salt containing a hydrophilic group to form an aqueous solution, and a cross-linking agent and water are added to the mixture to prepare a mixed solution, and an instep covering made of a raised fabric is immersed in the mixed solution. The first characteristic is to make an instep cover by using this instep cover material, dry it, adhere to the last, and injection-mold a shoe sole material containing polyvinyl chloride as the main component on the lower surface thereof.

A second feature of the manufacturing method according to claim 1 is that the hydrophilic urethane resin has a urea bond in the main chain and a carboxyl group in a part of the side chain. A third feature of the manufacturing method according to claim 1 is that the crosslinking agent is an epoxy-based crosslinking agent. Claim 1
In the production method described in (4), the fourth characteristic is that the crosslinking agent is an isocyanate crosslinking agent. A fifth feature of the manufacturing method according to the first aspect is that the mixed solution of the aqueous polyurethane resin, the cross-linking agent and water is used in a solid content concentration range of 0.1 to 7%.

The structure of the present invention will be described in detail below. (Aliphatic Polyester Polyol) An aliphatic polyester polyol having an average molecular weight in the range of 400 to 4000 is used, and examples thereof include polyethylene adipate, polybutylene adipate, and polycaprolactone.

Polyethylene adipate and polybutylene adipate are produced by a dehydration condensation reaction of adipic acid and glycol, and are used as an elastomer because they impart mechanical strength, heat resistance and oil resistance. Polycaprolactone is obtained by ring-opening polymerization of ε-caprolactam, and is characterized by a relatively low viscosity, excellent heat resistance, hydrolysis resistance, and low temperature characteristics in addition to the above characteristics, and is used as an elastomer.

(Organic diamine) In order to adjust the texture of the instep material, the modulus of the polyurethane resin can be changed. For that purpose, ethylenediamine, propylenediamine, piperazine, isophoronediamine,
Diamines such as 4-4′-diaminodicyclohexylmethane can be appropriately used in combination as a chain extender. The chain extender produces a urea bond by a secondary reaction with excess isocyanate in the system.

(Aliphatic or Alicyclic Diisocyanate) In the present invention, it is necessary to use a so-called non-yellowing diisocyanate. Aliphatic diisocyanates and alicyclic diisocyanates are known as non-yellowing diisocyanates. Hexamethylene diisocyanate can be used as the aliphatic diisocyanate, and xylene diisocyanate, isophorone diisocyanate, hydrogenated methylene diisocyanate, etc. can be used as the alicyclic diisocyanate.

(Salt containing hydrophilic group) It is used as a hydrophilizing agent in order to impart hydrophilicity to a hydrophobic polyurethane resin. In the present invention, a salt having a carboxyl group is used because it reacts with the cross-linking agent and improves the adhesion to the substrate.

(Aqueous Urethane Resin) The aqueous urethane resin can be classified into a forced emulsification type and a self-emulsification type based on an aqueous technique. The forced emulsification type mechanically emulsifies and disperses a urethane polymer by the force of an emulsifier. On the other hand, the self-emulsifying type is a method in which an emulsifier is not used, and instead, a segment forming an ethylene oxide component or a salt as a hydrophilizing agent is introduced into a polymer to emulsify and solubilize it.

The forced emulsification type aqueous urethane resin generally has good mixing stability with other resins, but the physical properties of the film may be deteriorated due to the influence of the emulsifier. For the above reason, the self-emulsifying type of the aqueous urethane resin of the present invention is used.

In the reaction step, urethane is first formed in a solution reaction, and then emulsified by an aqueous step.
This is a rather complicated process such as solvent removal at the end. The aqueous urethane resin of the present invention is an anionic aqueous urethane resin having a urea bond in the main chain and a carboxyl group in a part of the side chain. Introducing a urea bond into the main chain of polyurethane increases the thermal softening point and improves heat resistance and adhesiveness. Further, by introducing a salt having a carboxyl group in the side chain, it makes the hydrophobic polyurethane resin hydrophilic and contributes to the reaction with the crosslinking agent.

(Crosslinking Agent) Since the water-based urethane resin of the present invention is a thermoplastic type, it is possible to use a crosslinking agent in combination.
Improves water resistance, solvent resistance, and heat resistance. There are epoxy-based crosslinking agents and isocyanate-based crosslinking agents as types of crosslinking agents,
It is determined by the equivalent amount of reaction between the base polymer and the crosslinking agent. If the amount is too large, the performance may be lowered, and it is necessary to use an appropriate amount. In the case of epoxy-based cross-linking agents, the amount used is apparently water-based urethane (solid content 3
5 to 45%) 3 to 5 parts by weight or less based on 100 parts by weight,
In the case of an isocyanate crosslinking agent, it is desirable to use 10 parts by weight or less, and both may be used alone or in combination.

(Immersion of Upper Cover Material) When the raised woven fabric is immersed in the aqueous urethane mixed solution and dried, the amount of urethane resin applied to the upper cover changes depending on the concentration of the solid component, resulting in It greatly affects the texture of the material to be covered and the adhesion to the bottom material. In the present invention, the solid content concentration of the aqueous urethane mixed solution is 0.1
It is necessary to be in the range of ~ 7%. The solid content concentration
If it is less than 0.1%, the adhesion of the bottom material to the instep will be poor, and if it exceeds 7%, the texture of the raised fabric will be hard and the practical value will be reduced.

[0018]

The aqueous urethane aqueous solution used in this invention is
The ionic high-performance urethane resin is dispersed in water without using an emulsifier, so the physical properties of the film are not deteriorated, and it is chemically stable. It is easier to adjust the viscosity than a solvent-type urethane resin solution, and the viscosity can be significantly reduced. Furthermore, the addition of the cross-linking agent improves the water resistance, solvent resistance, and heat resistance, and as a result, the adhesion with polyvinyl chloride becomes good.

When the napped fabric is immersed in the aqueous urethane mixed solution, its viscosity is lower than that of a conventional organic solvent-based urethane resin solution, and it hardly penetrates or swells into a substrate. In spite of this, even though it penetrates evenly into the lower tissues, the texture of the raised part after drying does not become harder than the original texture and the soft feeling as a material can be maintained. Moreover, a shoe in which a shoe sole material containing polyvinyl chloride as a main component is injection-molded using this as an instep, has a large adhesive strength so that the appearance is excellent, and has excellent durability.

[0020]

EXAMPLE The water-based urethane resin described in this example is
Hydran HW-111 (registered trademark) manufactured by Dainippon Ink and Chemicals, Inc. The main component is an anionic non-yellowing type polyester urethane having a urea bond in the main chain and a carboxyl group in the side chain and having a softening point of 150 ° C. As a property, the solid content is 45% and the viscosity is BH type viscometer (rotor N
o.1, rotation speed 20 rpm) and 100 cps, PH
Is 7.5-8.8. Said Hydran HW-11
An epoxy type crosslinking agent, an isocyanate crosslinking agent and water were added to 1 (registered trademark) as described below to prepare a mixed solution of an aqueous urethane resin so that the solid content was 0.68%. An appropriate amount of 25% ammonia water was used for pH adjustment.

Blending parts by weight Hydran HW111 (solid content 45%) 100 Aliphatic epoxy-based cross-linking agent (solid content 40%) 5 Block isocyanate-based cross-linking agent (solid content 42%) 2 25% ammonia water proper amount water 7000 Solid content 0.68% PH 9 * viscosity 10 cps * measured with a BH type viscometer (rotor No. 1, rotation speed 20 rpm).

In the above aqueous urethane resin mixture solution (40/2
A velveteen woven fabric with a structure of × 30/1) / (7 × 210) is dipped, squeezed so that the adhered amount is 580 g / m ^{2 in} Wet minutes, dried at 150 ° C, and used as the material for the instep material. did. This material was used as the front cloth, and the suf was used as the back cloth, and a polyurethane foam sheet with good air permeability was placed between them, and dots were frame-bonded to obtain the instep covering.

This was cut into an instep shape, sewn on a cotton insole and caliphed, hung on the last, and a shoe sole material containing polyvinyl chloride as a main component was injection molded at 190 ° C. to obtain a shoe product.
This shoe product had a good texture of the instep, a good appearance, and a soft feeling. Also, the adhesion strength between the sole and the instep material was 2.9 kg / cm, which was extremely excellent. As a comparative example, the adhesion strength between the shoe sole and the instep material of a product made by the same method without dipping the same instep material is 1.0.
It was as low as kg / cm, which was far from the practical point of view.

[0024]

INDUSTRIAL APPLICABILITY In the present invention, the napped woven fabric is dipped in a mixed solution prepared by adding a cross-linking agent and water to an aqueous urethane resin having a urea bond in the main chain and a carboxyl group in the side chain, and drying the woven fabric. , Polyurethane resin penetrates evenly to the raised part and the underlying tissue of the instep, and does not impair the texture of the raised hair,
The original material has a soft feel, and a strong bond can be obtained with the sole material mainly composed of polyvinyl chloride.

Claims (5)

[Claims] 1. An (a) aliphatic polyester polyol,
(B) Organic diamine, (c) Aliphatic diisocyanate or alicyclic diisocyanate, (d) Hydrophilic polyurethane resin consisting of a salt containing a hydrophilic group is added with water to form an aqueous solution, and a crosslinking agent and water are added thereto. To make a mixed solution, soak the instep covering made of raised fabric in this mixed solution, dry it, make an instep using this instep covering, and apply it to the last, with polyvinyl chloride as the main component on the lower surface. A method of manufacturing an injection-molded shoe, which comprises injection-molding a shoe sole material. 2. The method for manufacturing an injection-molded shoe according to claim 1, wherein the hydrophilic urethane resin has a urea bond in a main chain and a carboxyl group in a part of a side chain. Method. 3. The method of manufacturing an injection-molded shoe according to claim 1, wherein the cross-linking agent is an epoxy cross-linking agent. 4. The method for manufacturing an injection-molded shoe according to claim 1, wherein the crosslinking agent is an isocyanate crosslinking agent. 5. The injection molding method according to claim 1, wherein the mixture of the aqueous polyurethane resin, the cross-linking agent and water is used in a solid content concentration range of 0.1 to 7%. Shoe manufacturing method.