JPH0330702A - Compression molding for multicolored outsole - Google Patents

Abstract

PURPOSE:To obtain a multicolored outsole having simple molding, a good exterior and excellent durability, by a method wherein a sole body-forming material and an insert-forming material which are formed of a foamed body, are compressed by heat and pressure, and sole body and an insert piece are molded thereby, and they are laid through an adhesive layer. CONSTITUTION:At least either of a sole body-forming material 1 and a differently colored insert-forming material 2 are formed of a foamed body with an expansion ratio of 1.3 to 2.0. They are bridge formed and their chief ingredient is a mixture of polymers, 1,2-polybutadiene of 40 to 90 pts.wt. with the crystallinity of 10 to 40% and diene synthetic rubber of 10 to 60 pts.wt. The upper surface 21 of the insert-forming material 2 is coated with an adhesive agent of which the chief ingredient is the 1,2-polybutadiene with a crystallinity of 10 to 40%, and thus an adhesive layer 3 is formed. The insert-forming material 2 is set in an insert section 41 formed by partition, on the bottom of a mold 4, and the sole body-forming material 1 is set thereon. By heat and pressure, both the sole body-forming material 1 and the insert-forming material 2 are compressed to 60 to 80% in volume, and a sole body 1' and an inset piece 2' are formed thereby, and they are laid through the adhesive layer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a compression molding method for multicolored shoe soles.

(Prior art) Conventionally, according to Japanese Patent Publication No. 60-6641, foamed sheets of different hardnesses made of 1.2 polybutadiene with diene rubber added as the main component were stacked one on top of the other and heated. A method of manufacturing shoe sole materials has been proposed in which upper and lower foam sheets are welded and laminated together under pressure. However, since the upper and lower foam sheets are simply welded and laminated together, the adhesive strength is insufficient, and the upper and lower foam sheets peel off during use, resulting in a lack of durability. Therefore, in practice, when laminating the upper and lower foam sheets together, a chloroprene-based or urethane-based adhesive is applied to both adhesive surfaces of the upper and lower foam sheets, and then the upper and lower foam sheets are stacked and heated. It was integrated with pressure lamination. Therefore, in molding a multi-colored shoe sole, prior to the present invention, the inventor of the present application applied a chloroprene-based or urethane-based adhesive to the laminated surface of the sole body molding material and the insert molding material in advance, and formed the sole body. Attempts were made to heat and press the material and the insert molding material to compress them into one piece, but as the sole body molding material was compressed during compression molding, the adhesive protruded around the insert piece to be insert molded, and the surrounding area This had the disadvantage that it oozed out and significantly deteriorated the appearance. Furthermore, since chloroprene-based and urethane-based adhesives have a pot life, strict time management was required during the molding process.

Furthermore, in order to eliminate these drawbacks, an attempt was made to apply adhesive only to the insert molding material in this compression molding method, but this method had the drawback of insufficient adhesiveness and lack of durability.

(Problems to be Solved by the Invention) The present invention aims to provide a multicolored shoe sole that is easy to mold, has a good appearance, and is highly durable.

(Means for Solving the Problems) In this invention, at least one of them has a foaming ratio of 1.
The sole body molding material 1, which is made of foam 3 to 2.0 times larger, and the insert molding material 2, which is different from this, are each made with a crystallinity of 1.
40 to 90 parts by weight of 0 to 40% 1.2 polybutadiene and 10 to 60 parts by weight of diene rubber are crosslinked and molded as main components, and the upper surface 21 of the insert molded material 2 has a crystallinity of 10%. A process of applying an adhesive mainly composed of ~40% 1.2 polybutadiene to form an adhesive layer 3, and inserting the insert molding material 2 into an insert chamber 41 defined by a partition wall 411 on the bottom of the mold 4. and setting the sole body molded material 1 on the upper surface thereof, and heat and press these at 110 to 150°C to form both the sole body molded material 1 and the insert molded material 2 made of foam, or both. Compress one side to 60-80% and make the sole body 1
The present invention provides a compression molding method for a multicolored shoe sole, which is characterized by the steps of: molding a sole body 1' and an insert piece 2', and laminating the sole body 1' and the insert piece 2' via an adhesive layer 3. That is. In this invention, the 1.2 polybutadiene having a crystallinity of 10 to 40% among the components for forming the sole body molding material 1 and the insert molding material 2 is, for example, JSRRB810. RB820. R
B830. A commercially available product under the trade name RB840 is used. These foams using 1.2 polybutadiene retain some thermoplasticity even after cross-linking foam molding, and by compression molding by heating and pressurizing in a mold, the surface becomes denser and has sharp irregularities. It is possible to mold a design, but the foam shrinks significantly after compression molding, resulting in poor dimensional stability and problems with tensile strength, tear strength, etc.6
Mechanical strength can be improved by mixing one or more diene rubbers within the above range with the 1.2 polybutadiene.

As the diene rubber, natural rubber, styrene-butadiene rubber, polyisoprene rubber, polybutadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, etc. are used. Gen rubber is preferred.

In this invention, the mixing weight ratio of 1.2 points IJ-butadiene and diene rubber is set to 50~qo:to~50 because if the mixing weight ratio of diene rubber is less than that, the mechanical strength will decrease. If the mixing weight ratio of the diene rubber is lower than that, the thermoplasticity of the foamed sheet will decrease and compression molding will become impossible.

In this invention, the mixed polymer further includes a crosslinking agent,
A coloring agent is added, but as a crosslinking agent to be added,
Sulfur, dicumyl peroxide, 2,5-dimethyl-2
, 5-di(tert-butylperoxy)hexane, benzoyl peroxide, tert-butyl peroxide, and the like, which are commonly used for crosslinking rubber, are used.

Furthermore, a foaming agent is added to the components of the sole body molding material 1 and/or the insert molding material 2 to be foam-molded, and the foaming agent may be an azo compound such as azodicarbonamide. , nitroso compounds such as dinitrosopendamethylenetetramine, and blowing agents such as P,P'oxybisbenzenesulfonyl hydrazide are used.

Coloring agents of different colors are appropriately selected for the sole body molding material 1 and the insert molding material 2, respectively. In addition, crosslinking aids, crosslinking accelerators, fillers and stabilizers such as white carbon, carbon black, rhusium carbonate, and magnesium carbonate are added to the mixed polymer as necessary, and the mixture is mixed with a Banbury mixer, Henschel mixer, etc.
The mixture is uniformly mixed using a mixer such as a mixing roll or a kneader, and then heated and pressurized using a press mold for cross-linking molding.

In this case, the molding components of the sole body molding material 1 and the insert molding material 2 to which a foaming agent is added are simultaneously foam-molded.

Then, the foam-molded material is further heated in an oven etc. for 11 minutes.
If these molded materials are heated for 1 to 3 hours at 0°C to 150°C to shrink by 5 to 10%, heat shrinkage after compression molding can be avoided and a polyester with excellent dimensional stability can be obtained. You can get colored soles.

In this invention, the adhesive layer 3 for the insert molding material 2 is formed by applying 1,2 polybutadiene, which is used for molding the sole body molding material 1 and the insert molding material 2, in a heated and molten state.

Alternatively, it is formed by dissolving this 1.2 polybutadiene in a solvent such as an aromatic hydrocarbon such as benzene or toluene xylene, or a pagenated hydrocarbon such as carbon tetrachloride, trichloroethylene, or isopropyl chloride, and applying the solution.

In this invention, the insert chamber 41 is formed into sections by making a partition wall 411 protrude from the bottom surface of the mold 4 using a conventional method.

The sole body molding material 1 and the insert molding material 2 prepared in this manner are further molded into a mold cavity 40, if necessary. The insert molding material 2 is cut according to the shape of the insert chamber 41 and set in the insert chamber 41, and the sole body molding material 1 is placed on top of it and set in the mold cavity 40, and then heated by the upper mold 5. Both or one of the shoe sole body molding material 1 and the insert molding material 2, which are formed of pressurized foam, is heated to 60 to 80% of their volume.
% and mold the sole body 1' with the sole body molding material 1, insert molding an insert piece 2' on the ground surface with the insert molding material 2, and further melt the adhesive layer 3 by heating during insert molding. The multicolored sole according to the present invention is formed by welding and integrating the sole body and the insert piece.

EXAMPLES With the composition shown in Table 1, the sole body molding material 1 was foam-molded by a conventional method at a foaming ratio of 1.6 times to a wall thickness of 15 nwi, and the insert molding material 2 was foam-molded at a foaming ratio of 1.6 times to a wall thickness of 7I. After that, they were heated in an oven at 12.5°C for 3 hours to shrink by 7% to remove the shrinkage, and then JSIIIRB820 (1.2 polybutadiene manufactured by Japan Synthetic Rubber Co., Ltd.) 100 was further applied to the surface of the insert molded material 2. An adhesive prepared by dissolving 9.0 parts by weight of toluene was applied and dried to form an adhesive layer 3.

The sole body molded material 1 prepared in this way is cut into the shape of the mold cavity 40, and the insert molded material 2 is cut into the shape of the insert chamber 41, and the insert molded material 2 is cut into the insert chamber with the adhesive layer 3 facing upward. 41, overlaid the sole body molding material 1 on top of it, and set it in the mold cavity 40. Then, they were heated at 130°C and heated at 100 kg/a ((press gauge pressure) with the upper mold 5). The multicolored shoe sole according to the present invention was compression molded by compressing the volume to 70%.

The appearance of the multi-colored sole formed in this way was compression-molded by applying urethane adhesive to both the sole body molding material and the insert molding material, which were then foam-molded and dried. A comparison of adhesive properties is shown in the lower row of Table 1.

(Effects of the Invention) In this invention, the 1 and 2 polybutadiene forming the adhesive layer 3 is thermoplastic and has no pot life, and also has the same components as the sole body molding material 1 and the insert molding material 2, so compression molding is possible. When heated, it melts and mutually melts into the sole body molding material 1 and the insert molding material 2, making it possible to strongly adhere them, making the molding process easy and highly durable. Moreover, in the multicolored shoe sole obtained by this invention, the adhesive layer 3 is formed by insert molding material 2.
Since horizontal compression during compression molding of the insert molded material 2 coated and molded with the adhesive layer 3 is restricted by the partition wall 411 that partitions the insert chamber, the adhesive layer 3 is compressed during the compression molding. insert piece 2'
It does not protrude around the area and has a good appearance.

×... Adhesive protrudes around the insert piece.

[Brief explanation of drawings]

The drawing is a sectional view of a main part showing the state of implementation of the present invention. Explanation of the code 1. Sole body molding material 2. Insert molding material 21...
・Top surface 3. Adhesive layer 4, mold
40... Mold cavity 41... Insert chamber 411... Partition wall 5, upper mold

Claims (1)

[Claims] At least one of them has a foaming ratio of 1.3 to 2.0
The sole body molding material 1, which is made of double foam, and the insert molding material 2, which is different from this, each have a crystallinity of 10 to 40%.
1.2 A step of crosslinking molding using a mixed polymer of 40 to 90 parts by weight of polybutadiene and 10 to 60 parts by weight of diene rubber as a main component, and a step of crosslinking molding with a crystallinity of 10 to 40% on the upper surface 21 of the insert molded material 2. 1.2 The process of applying an adhesive containing polybutadiene as a main component to form the adhesive layer 3, and setting the insert molding material 2 in the insert chamber 41 defined by the partition wall 411 on the bottom of the mold 4; A step of setting the sole body molding material 1 on the upper surface, and heating and pressing them at 110 to 150°C to heat the sole body molding material 1 and/or the insert molding material 2 formed of foam at 60 to 150°C. A multi-colored shoe which is characterized by the step of compressing it to 80% to form the sole body 1' and the insert piece 2', and laminating the sole body 1' and the insert piece 2' with an adhesive layer 3 interposed therebetween. Compression molding method for shoe soles.