JPH01166702A - Method for manufacturing earth-contacting shoe sole of foamed polyurethane - Google Patents

Abstract

PURPOSE: To give leather-like luster and improve the appearance of the grounding bottom by fitting a half-hardened foamed polyurethane sheet in a lower empty hole before cooling, pressurizing an compressing together with the upper mold in the normal temperature. CONSTITUTION: The half-hardened foamed polyurethane sheet as fitted in the shape of surfaced external bottom in the lower empty hole before cooling, pressurized and compressed together with the upper mold in the normal temperature, and the three-dimensional design on the grounding surface is formed. The foamed polyurethane sheet is ion the half-hardened condition, and although the reaction is not totally completed, it is hard enough so that it will not loose its shape. Therefore, it is possible to mold it as desired by adding more pressure in the future. The temperature inside of the sheet is, for instance, around 90-100 deg.C, which is slightly lower than the maximum temperature, 130 deg.C. It is better to pile up clothes or nonwoven cloths made of natural fiber on the upper side of the sheet in order to improve adhesiveness considering the case of placing it in layers with the middle bottom. The forming polyurethane sheet is shaped immediately without cooling under the pressure of 130-150kg/cm<2> for 0.5-10 minutes in the mold in the normal temperature for forming the shape of the grounding bottom, and the uneven surface is formed on the grounding face.

Description

[Detailed description of the invention] The present invention relates to a method of manufacturing a foamed polyurethane ground sole.

The manufacturing process for the foamed polyurethane outer sole is relatively simple, and it is lightweight, highly elastic, and has excellent bending resistance in cold weather.
Moreover, it is widely used because it is comfortable to wear.

Normally, foamed polyurethane outer soles are produced by pouring the required amount of the foamed polyurethane liquid mixture as a raw material into the outer sole forming cavity of a lower mold at an appropriate temperature, combining it with an upper mold, and heating it for an appropriate temperature time under predetermined conditions. , manufactured by foaming and curing within the outer sole forming cavity.

However, although the foamed polyurethane outer sole obtained in this way has the necessary physical properties as a foamed polyurethane outer sole as described above, the corners and ridges of the three-dimensional design of the ground contact surface are missing. It has drawbacks such as small pores caused by air bubbles appearing in the smooth part, and the ability to obtain only the gloss characteristic of polyurethane, which reduces the commercial value of the product, such as customers quickly getting tired of it.

The drawback that reduces the product value as mentioned above is that the main part of the outsole is the ground sole (in this case, if the outsole is a - layer, the ground sole becomes the outsole, and if there are multiple layers, the bottom layer is The inventor paid attention to the fact that this occurs in the ground layer, and the layer located above it becomes the intermediate sole.

The purpose of the present invention is to provide the ground sole in such a case without chipping at the corners or ridges of the three-dimensional design surface, without forming small holes on the smooth surface, and without the gloss peculiar to polyurethane. An object of the present invention is to provide a ground sole that has a leather-like luster, which improves the appearance of the ground sole and increases its commercial value.

The above purpose is to fit a semi-cured foamed polyurethane sheet with a smooth outer bottom shape into the cavity of a lower mold at room temperature before cooling, combine it with an upper mold at room temperature, compress it under pressure, and apply it to the ground surface. This was achieved through a method of manufacturing a foamed polyurethane ground sole, which is characterized by the formation of a three-dimensional design.

Here, a lower mold having an uneven surface for forming a three-dimensional design on the inner surface of the cavity and an upper mold having a smooth lower surface are combined to form a mold, or a lower mold having a smooth inner surface on the cavity. A mold is used that combines the upper mold with an uneven surface for forming a three-dimensional design on the lower surface.

The foamed polyurethane sheet with a smooth surface and an outer bottom shape is molded using the prepolymer method, and although the reaction is not completely completed in a semi-cured state, it has been cured to the extent that the mold does not peel (normally, the reaction is 90x (It is best to use a mold that has been completed to a certain extent), and a mold that can be molded to the desired shape by subsequent pressurization is used.

At this time, the temperature inside the sheet used is, for example, about 90 to 100°C, which is slightly lower than the maximum temperature of around 130°C.

In consideration of the case where the sheet is laminated with an intermediate sole, it is preferable to laminate a cloth or nonwoven fabric made of natural fibers on the upper surface of the sheet in order to improve adhesion.

The foamed polyurethane sheet in the shape of an outer sole, which has an internal temperature of 90 to 100°C in a semi-cured state, is placed into a mold at room temperature to form a shape of a grounded sole as soon as possible without cooling. ~10 minutes, 130-150 kg/cI11
The desired uneven surface is formed on the ground surface by stamping with the pressure of .

First of all, the present invention has a smooth surface with no chips or small pores caused by air bubbles, a gloss characteristic of polyurethane, and a reaction rate of about 9%.
A foamed polyurethane sheet in a semi-cured state that has been cured to about 0X is prepared, and then this sheet is placed in a mold at room temperature that has an uneven surface capable of forming a desired three-dimensional design on a predetermined surface of an upper mold or a lower mold. Since the egg is placed inside and compressed under pressure, the egg has the desired three-dimensional design, no chips on the ridge, no small holes caused by air bubbles on the smooth part, and has an excellent appearance with a leather-like luster. It was possible to obtain a grounding sole with a desired three-dimensional design.

Example 1 Butylene adipate-based polyester polyol, 1.
A foamed polyurethane liquid mixture whose main components are 4-butanediol and methylene diisocyanate (or a foamed polyurethane liquid mixture whose main components are a polypropylene glycol-based polyester polyol and methylene diisocyanate) is placed in contact with the lower mold (temperature 30"C). Pour a predetermined amount of foam into the underground formation cavity so that the specific gravity after hardening is 0.6, combine with the upper mold (temperature 30°C), and press 0.5 kg for 5 minutes.
The sheet was compressed at a pressure of /cnl and then taken out to obtain a foamed and hardened sheet with a smooth contact surface and top surface.

Immediately cut this sheet into a lower mold (with a smooth inner surface and a hollow part).
Temperature: 30°C) and combined with an upper mold (temperature: 30°C) having an uneven surface for forming a three-dimensional design on the lower surface, 0.5
The ground-contact sole (
A specific gravity of 0.7) was obtained.

Example 2 The foamed semi-cured sheet with a smooth ground surface obtained in Example 1 was immediately placed into the ground bottom forming cavity of a lower mold (temperature 30°C) having a three-dimensional design on the inner surface without cooling. Combine with an upper mold with a smooth lower surface (temperature 30°C), 0.5 to 2 minutes, 14
After compressing with a pressure of 0 kg/cJ and reaching a specific gravity of 0.7, the upper mold is removed, and then an intermediate mold (temperature A predetermined amount of the foamed polyurekne liquid mixture used in Example 1 was added so that the specific gravity after foaming and curing would be 0.6, and combined with the upper mold (temperature: 30°C) for 6 minutes. , 0.5k
By pressurizing at a pressure of g/cni, an outer sole consisting of two layers, an intermediate sole and a ground sole, which achieved the intended purpose of the present invention, was obtained.

Example 3 The foamed polyurethane liquid mixture used in Example 1 was
Rectangular cavity (10001mX) of the lower mold (temperature 30℃)
A predetermined amount was put into a 150 (1+n) container so that the specific gravity after foaming and semi-curing was 0.6, combined with an upper mold (temperature 30°C), compressed under pressure of 0.5 kg/cal for 5 minutes, and taken out. A foamed semi-cured sheet with a smooth contact surface and a smooth upper surface was obtained.

Immediately cut this sheet into a ground bottom shape with a blade die without cooling it, and cut it into a bottom die with a three-dimensional design on the inner surface (temperature 30℃)
Insert into the ground bottom forming cavity and combine with the upper mold, 0.5~2
It was compressed under a pressure of 140 kg/cnl per minute and taken out after cooling to obtain a grounding sole that achieved the intended purpose of the present invention.

Claims (3)

[Claims] (1) A foamed polyurethane sheet in a semi-cured state with a smooth surface and an outer bottom shape is fitted into a lower cavity at room temperature before cooling,
A method for manufacturing a foamed polyurethane ground sole, which is characterized by combining it with an upper mold at room temperature and compressing it under pressure to form a three-dimensional design on the ground surface. (2) The method for producing a foamed polyurethane ground sole according to claim 1, wherein the lower mold has an uneven surface for forming a three-dimensional design on the inner surface of the cavity, and the upper mold has a smooth lower surface. (3) The method for manufacturing a foamed polyurethane ground sole according to claim 1, wherein the lower mold has a smooth bottom surface in the cavity, and the upper mold has an uneven surface for forming a three-dimensional design on the lower surface.