JPH09224713A - Impregnated composition for core material of shoe and manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a core material, which requires no organic solvent in the adhesion with a shoe and which can stick by thermal reactivation, and an impregnated composition used for manufacturing the core material for a shoe. SOLUTION: An impregnated composition for a core material is provided which consists of ethylene/vinyl acetate copolymer resin of 35-50 parts, tackifier resin of 30-50 parts, waxes of 0-20 parts, antioxidant (oxidation inhibitor) of 0.1-0.5 parts, and the remainder (elastomer, plasticizer, etc.) of 0-20 parts. Desirably, the ethylene/vinyl acetate copolymer resin contains 14-40% of vinyl acetate with the melt index of 1-400-(g/10min). Then, an adhesive body is obtained by placing a pattern, shoe core material (toe core, crescent core) and artificial leather on a press base and pressing them together.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for manufacturing a shoe core material, for example, an impregnating composition used for a shoe core material and a shoe core material.

[0002]

2. Description of the Related Art Conventionally, a core material for shoes has been used for imparting shape-retaining properties to the tip and heel of a shoe. A woven or non-woven fabric impregnated with a thermoplastic resin is used as a shoe tip. It is used by adhering it to the inside of the heel part. This adhesion is performed by reactivating a woven fabric or a non-woven fabric with a solvent or heat, or by using an adhesive. In the shoemaking industry, the ASEAN countries including China are catching up,
The industry is in a recession, and there is a current demand for low-cost shoe core materials.

Conventional shoe core materials can be classified into three types according to the method of adhering to the shoes. The first type is to reactivate the core material with a solvent and bond it to a predetermined part of the shoe.For example, a thermoplastic resin emulsion such as polystyrene emulsion or styrene-acrylic copolymer emulsion is impregnated into the woven or non-woven fabric. , A sheet formed by drying and solidifying. The second type is a method of adhering the core material to the shoe with an adhesive, for example, a method of adhering the sheet having the composition used in the first type with a natural rubber latex type adhesive. The third type is a method of adhering a core material to shoes by heat reactivation. For example, an ethylene / vinyl acetate copolymer-based hot melt adhesive is processed on a sheet produced by the above composition and method. There is a method of adhering things to shoes by heat reactivation.

[0004]

However, the core material of each of the above-mentioned types of shoes still has problems to be solved. First, the core material of the first type and its bonding method are low in cost and have good workability during bonding. However, since an organic solvent is used at the time of bonding, there is a danger of fire, etc., and it does not match the present times. The second type of bonding method is that the workability is poor because the core material is bonded to the shoe by using an adhesive, which is the greatest difficulty.
The third type of core material and the bonding method have the advantage that the core material can be bonded to the shoe by heat reactivation and therefore workability is excellent without using an organic solvent. But,
The core material used in this type is manufactured by the steps of impregnating a woven cloth with a thermoplastic resin such as styrene emulsion and drying and solidifying it, and the step of coating an adhesive mainly composed of ethylene / vinyl acetate resin. And two steps are required. Therefore, there is a drawback that the manufacturing cost becomes high. The core material has a structure in which a hot-melt adhesive is applied on an impregnated woven fabric or nonwoven fabric. Therefore, when the cut surface is skived, there is a drawback that the surface not coated with the hot melt adhesive appears as an adhesive surface.

The present invention has been made under the above background,
The problem is to eliminate the drawbacks of the core material. That is, it is an object of the present invention to provide a core material that does not require an organic solvent at the time of adhesion to a shoe and can be bonded by heat reactivation, and an impregnation composition for a core material of a shoe used for manufacturing the core material. To do. It is also an object to provide a core material that can be manufactured in one step, and to provide a shoe core material in which the hot-melt adhesive is applied to the finished surface as well. .

[0006]

In order to solve the above-mentioned problems, the present inventors have completed the present invention through intensive studies. That is, the present invention provides an impregnating composition for a shoe core material having the composition shown in the following table.

[0007]

[Table 2] Components Solid content ratio (weight ratio) Ethylene / vinyl acetate copolymer resin 35-50 Tackifying resin 30-50 Wax 0-20 Antioxidant (antioxidant) 0.1-0.5 Balance ( Elastomer, plasticizer, etc.) 0-20 Preferably, the ethylene / vinyl acetate copolymer resin is
The content of vinyl acetate is 14 to 40%, and its melt index is 1 to 400 (g / 10 minutes).
The present invention also provides a shoe core material obtained by impregnating a base material for a shoe core material with a mixed emulsion of the above-mentioned impregnation composition for a shoe core material, an emulsifier and water, and drying the mixture.

The present invention will be described in more detail. First, there is an emulsion type ethylene / vinyl acetate resin which is one of the main components of the hot melt adhesive. The above-mentioned various problems can be solved by developing an emulsion-type hot-melt adhesive and manufacturing a core material by impregnating a woven fabric and a non-woven fabric. Among the compositions shown in Tables 1 and 2, ethylene / vinyl acetate copolymer resin (EV
The role of A) is to provide the adhesive with flexibility, cohesion and adhesion as the base polymer. The kind that can be used as the base polymer of the hot-melt adhesive is obtained by a high-pressure radical polymerization method, and preferably has a vinyl acetate content of 14 to 40 wt% and a melt index of 1 to 400 (g.
/ 10 minutes). Base material for shoe cores (woven or non-woven)
When the above composition is impregnated with the above composition, it is preferable to use an emulsifier in this composition to form an emulsion form in which the composition is dispersed in water. In addition, the active ingredient is 40 to 50 wt%
It is preferable that

The tackifying resin is added to increase the adhesiveness and to reduce the melt viscosity, and is not particularly limited, but for example, rosin and its derivatives, terpene resin, hydrocarbon resin and the like are used. To be In the present invention, it is preferable to use an emulsion type which is dispersed in water using an emulsifier. Waxes are used for lowering the viscosity at the time of melting, adjusting the open time and hot tack. The type thereof is not particularly limited, and examples thereof include paraffin wax, microcrystalline wax, low molecular weight polyethylene wax, Fischer-Tropsch wax, montan wax and the like. The antioxidant (antioxidant) is added in a small amount in order to improve the thermal stability when it is melted by heat, and is not particularly limited, but for example, 2,6-di-t-butyl-4-methylphenol. 4,4'-thiobis (3-methyl-6-t-butyl
-m-cresol).

In addition, an elastomer added for the purpose of improving the cold resistance, flexibility and impact resistance of the core material,
There are plasticizers added for the purpose of flexibility, cold resistance, etc.
It can be added as appropriate. In addition, fillers such as calcium carbonate, barium sulfate, titanium oxide, clay, and talc, which are added for the purpose of preventing blocking, may be added as an extender, and these may also be added arbitrarily. On the other hand, a shoe core material can be obtained by impregnating a base material (woven or non-woven fabric) for a shoe core with the composition having hot melt property in an emulsion state.

Conventionally, a core material used as a hot melt composition (a hot melt type core material) is obtained by impregnating a woven cloth or a non-woven cloth with a thermoplastic emulsion such as polystyrene emulsion or styrene-acrylic copolymer emulsion and drying it. It was a two-step production process of processing a hot-melt adhesive, but in the present invention, EVA having adhesiveness was processed as an emulsion by impregnation.
If it can be used as it is by utilizing its hot-melt property, it will be very useful in terms of labor saving. Also, unlike applying hot-melt adhesive to the surface, since it is an impregnation process, the structure has a hot-melt adhesive on the cut surface as well. There is an advantage that the surfaces can be bonded. The core material of the present invention can be bonded to a predetermined part of a shoe (shoe tip, heel, etc.) using heat and an adhesive. Therefore, the fire of dangerous substances due to the reactivation of the solvent will not occur.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. In the present embodiment, first, the following Table 3
The impregnating composition samples 1 to 8 having the composition shown in Table 1 were manufactured.

[0013]

[Table 3]

Then, each of the samples 1 to 8 was impregnated into a sample woven fabric or a non-woven fabric, and the shoe core material thus obtained was adhered to a predetermined portion of the shoe, and the adhesiveness was examined. First, the above-mentioned impregnation composition samples 1 to 8 for core material were manufactured.
The manufacturing process of these samples is shown below. (1) First, in a stainless steel stirring pot equipped with stirring equipment,
Add EVA emulsion. (2) Immediately after adding the EVA emulsion, stirring is started at room temperature (stirring speed: 20 to 50 rotations). (3) While stirring, gradually add other composition materials in order. (4) After all the composition materials have been added, the stirring is continued for about 1 hour, and when the solution becomes uniform, the stirring is stopped.

A woven fabric / nonwoven fabric was impregnated with the sample obtained as described above to obtain a shoe core material. The method is described below. First, each sample is dipped into a woven or non-woven fabric to be impregnated, and the thickness is adjusted while squeezing with two glass rods. 10 to 10 in a constant temperature bath at 130 to 150 ° C
Dry for 5 minutes to obtain a shoe core material. As shown in FIGS. 1 (a) and 1 (b), a pattern paper, shoe core material (tip shin, lunar shin) and synthetic leather / leather are placed on the press table with respect to the shoe core material thus obtained. It was placed and pressed to obtain an adhesive body in which a shoe core material was adhered to a shoe, and a normal state adhesive strength test and a moisture resistance adhesive strength test were performed on this. In addition, the normal-state adhesive strength test was conducted after the above-mentioned adhesive body was adhered and left at room temperature for 24 hours. In the moisture-resistant adhesive strength test, after the above-mentioned adhesive body is adhered, it is left at room temperature for 24 hours and placed in a constant temperature bath at a temperature of 40 ° C and a humidity of 96%. Further, after 48 hours, the adhesive was taken out of the constant temperature bath and allowed to stand at room temperature for 1 hour before being tested. In this measurement, 25 mm x 1
A 00 mm sheet is bonded to leather (kibs) and synthetic leather under the conditions of 150 ° C, 0.5 MPa, 3 to 7 seconds, and the temperature is set to 4 at room temperature.
After standing for 8 hours, the hardness e (bending moment) is calculated by the equation 1 using an Olsen stiffener tester (according to JIS K 7106).

[0016]

[Equation 1] e = (4S / W) × (MN / 100φ) However, e: Bending moment (N · m) W: Width (cm) φ: Bending angle (radian) N: Road reading S: Span ( cm) M: Maximum moment of pendulum (Nm)

When measuring, the pulling speed is 50 m.
Instron 4467 (manufactured by Instron Co.) was used as a tester with m / min and a peeling direction of 180 degrees. In addition, Clarino 2019-0000 (manufactured by Kuraray) was used as the synthetic leather and Merck Kip Black was used as the leather. Table 4 shows the test results. However, in Table 4, * indicates partial destruction of the surface layer of the adherend and ** indicates total destruction of the surface layer of the adherend. Further, at the time of hot pressing, a pattern paper having a thickness of 60 μm was used instead of the back cloth and the back skin.

[0018]

[Table 4]

From the above results, it is shown that the impregnating compositions for core materials of Test Examples 1 to 8 have performance comparable to conventional products and can withstand practical use. Further, the conventional hot-melt shoe core material is manufactured by impregnating a woven cloth or a non-woven cloth with a thermoplastic resin emulsion, drying it, and then coating the hot-melt adhesive with it. On the other hand, in the present embodiment, the hot-melt core material is manufactured by impregnating and drying a woven fabric or a non-woven fabric with a composition that can be a hot-melt adhesive after drying. That is, the hot-melt core material that has been conventionally manufactured by two steps is manufactured by one step, which is advantageous in terms of cost.

[0020]

The impregnating resin composition for a shoe core material of the present invention comprises:
It is a composition containing an ethylene / vinyl acetate copolymer resin as a main component, and by impregnating this in a woven or non-woven fabric in an emulsion state and drying and solidifying, a shoe core material can be manufactured. Therefore, the core material for shoes can be manufactured in one step, the manufacturing cost can be reduced, and a low-cost core material can be supplied. Further, it is not necessary to use an organic solvent at the time of adhering the shoe core material, which is advantageous in that it is solvent-free and the manufacturing process is shortened.

[Brief description of drawings]

1A and 1B are explanatory views of an adhesion test of a shoe core material.

Claims (3)

[Claims] 1. Composition shown in the following table: [Table 1] Component Solid content ratio (weight ratio) Ethylene / vinyl acetate copolymer resin 35-50 Tackifying resin 30-50 Wax 0-20 Antioxidant (antioxidant Agent) 0.1-0.5 balance (elastomer, plasticizer, etc.) 0-20 impregnating composition for shoe core material 2. The ethylene / vinyl acetate copolymer resin has a vinyl acetate content of 14 to 40% and a melt index of 1 to 400 (g / 10 minutes). The impregnating composition for a core material of a shoe according to item 1. 3. A shoe core material obtained by impregnating a base material for a shoe core material with a mixed emulsion of the impregnating composition for a shoe core material according to claim 1 or 2, an emulsifier and water and drying the mixture.