JP2591700B2 - Method for producing vinyl chloride resin foamed leather - Google Patents

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 a vinyl chloride resin foamed leather, and more particularly, to a vinyl chloride resin foamed leather having a soft surface, excellent elasticity and excellent strength. The present invention relates to a method for producing resin foamed leather.

[0002]

2. Description of the Related Art Conventionally, a normal pressure foaming method is known as one of the typical methods for producing a vinyl chloride resin foamed leather. In the normal pressure foaming method, after molding a vinyl chloride resin composition containing a foaming agent at a temperature lower than the decomposition temperature of the foaming agent, the foaming agent is heated to a temperature not lower than the decomposition temperature of the foaming agent to decompose the foaming agent. A foamed leather is obtained by generating a gas, and a foamed leather having a low expansion ratio is conventionally produced by the normal pressure foaming method.

[0003] However, such low-foam vinyl chloride resin leather is hard and heavy, and has a strong so-called sensation. Therefore,
Such foamed leather is lightweight, has a soft leather-like feel, has excellent elasticity, and is also required to have a high interlayer strength and a high tensile strength. It is hard to use for etc. On the other hand, in the conventional normal pressure foaming method, if the foaming ratio is increased and the porosity of the foamed layer is increased, the foamed leather obtained has higher elasticity and lighter weight, but the tensile strength and the interlayer strength are extremely small. Therefore, it is difficult to use as a material for the above-mentioned shoes, bags, and the like.

Therefore, conventionally, in order to increase the tensile strength of the foamed leather obtained, for example, a partially crosslinked acrylonitrile-butadiene copolymer and an acrylic resin are blended with a vinyl chloride polymer together with a plasticizer and a foaming agent. A method for foaming this is proposed in Japanese Patent Application Laid-Open No. 62-187742. However, according to this method, the resin material may be non-uniform, it is difficult to obtain foamed leather having uniform physical properties, and it is also difficult to give a soft texture to the surface.

Further, JP-A-1-250478 proposes a vinyl chloride resin foamed leather having an intermolecular cross-linked structure formed by urethane bonds. However, according to this method, there is a problem in weather resistance.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the conventional production of a vinyl chloride resin foamed leather by the normal pressure foaming method as described above. Has a feeling, high elasticity,
Moreover, it is an object of the present invention to provide a method for producing a vinyl chloride resin foamed leather having excellent strength.

[0007]

According to the present invention, there is provided a method for producing a foamed leather of a vinyl chloride resin, comprising: laminating a composition containing a vinyl chloride polymer, a plasticizer and a foaming agent together with a radical initiator on a substrate; It is characterized by pressure foaming. The vinyl chloride polymer used in the present invention is an ordinary copolymer obtained by suspension polymerization, emulsion polymerization, bulk polymerization, or the like of vinyl chloride or a comonomer having copolymerizability with vinyl chloride. Examples of the comonomer include vinyl acetate, vinyl esters such as vinyl propionate, ethylene, propylene, olefins such as styrene, methyl acrylate, ethyl acrylate, and (meth) acrylates such as methyl methacrylate; Maleic acid diesters such as dibutyl maleate and diethyl maleate; fumaric acid diesters such as dibutyl fumarate and diethyl fumarate; vinyl cyanide such as acrylonitrile and methacrylonitrile; vinyl halides such as vinylidene chloride and vinyl bromide; and methyl Examples thereof include vinyl ethers such as vinyl ether and ethyl vinyl ether. The content of these comonomers in the vinyl chloride copolymer is usually 50% by weight or less, preferably 10% by weight or less.

In the present invention, these polyvinyl chloride or vinyl chloride copolymer has an average degree of polymerization of 2,000.
It is necessary to be above. Preferably it is 2500 or more. When the average degree of polymerization of the polyvinyl chloride or copolymer used is smaller than 2,000, the obtained foamed leather does not have sufficient strength, and when a high foam is used,
Does not have high elasticity and uniform cell structure.

According to the present invention, the vinyl chloride polymer constituting the foamed leather is effectively crosslinked by a radical initiator and has a three-dimensional structure. It is possible to obtain a foamed leather having a good feel and a high interlayer strength and a high tensile strength. In the present invention, an organic peroxide or a bisazo compound is preferably used as the radical initiator. As the organic peroxide, for example, dicumyl peroxide can be mentioned as a preferred example, but is not limited thereto. Such an organic peroxide is usually 0.1 to 100 parts by weight of the vinyl chloride polymer.
Used in the range of 5 parts by weight. Further, as the azobis compound, for example, azobisisobutyronitrile can be mentioned as a preferable example, but it is not limited to this. Such an azobis compound is usually used in an amount of 0.1 to 100 parts by weight of the vinyl chloride polymer.
It is used in the range of up to 20 parts by weight. These organic peroxides and bisazo compounds may be used in combination within the range described above.

As the blowing agent used in the present invention, conventionally known blowing agents may be used. Examples thereof include azodicarbonamide, p, p'-oxybenzenesulfonylhydrazide, p-toluenesulfonylhydrazide, and benzene. Although sulfonyl hydrazide etc. can be mentioned, azodicarbonamide is particularly preferably used.

In the present invention, the foaming agent is used in an amount of 5 to 20 parts by weight, preferably 8 to 15 parts by weight, per 100 parts by weight of the resin composition so that the obtained foamed leather has a high expansion ratio. Can be When the amount of the blowing agent is too small, high foaming cannot be performed. On the other hand, when the amount exceeds 20 parts by weight with respect to 100 parts by weight of the vinyl chloride polymer, the cell structure becomes non-uniform, Not preferred.

As the heat stabilizer, any conventional heat stabilizer can be used. For example, metal compounds such as lead, zinc, cadmium, barium, sodium, potassium, calcium, lithium and tin, especially Are preferably used. Such a heat stabilizer is used in an amount of 1 per 100 parts by weight of the resin composition.
It is used in an amount of from 6 to 6 parts by weight, preferably from 2 to 4 parts by weight.

Further, the plasticizer used in the present invention may be any plasticizer conventionally used for producing a vinyl chloride resin foamed leather.
Octyl phthalate (di-2-ethylhexyl phthalate), diesters of phthalic acid such as dibutyl phthalate and dinonyl phthalate, diesters of aliphatic dibasic acids such as dioctyl adipate and dioctyl sebacate, tricresyl phosphate, trioctyl phosphate Phosphoric triesters such as ate, epoxy plasticizers such as epoxidized soybean oil and epoxy resin, and high molecular polyester plasticizers are preferably used.

Examples of the high-molecular polyester plasticizer include polyethylene glycol diester of phthalic acid,
Polyalkylene glycol diesters such as polypropylene glycol diester and polyethylene glycol polypropylene glycol diester, and polyethylene glycol diesters of aliphatic dibasic acids such as adipic acid and sebacic acid, polypropylene glycol diester, and polyethylene glycol polypropylene glycol diester. Polyalkylene glycol diesters.

In the present invention, these plasticizers are used in an amount of 40 to 200 parts by weight, preferably 50 to 150 parts by weight, based on 100 parts by weight of the resin composition. When the amount of the plasticizer is out of the above range, the obtained foamed leather tends to decrease in elasticity, which is not preferable. The vinyl chloride-based resin foamed leather according to the present invention, in addition to the foaming agent as described above, a vinyl chloride-based polymer composition containing a radical initiator is mixed and kneaded according to a conventional method,
After being formed into a sheet at a temperature equal to or lower than the decomposition temperature of the foaming agent by a calender or an extruder, the sheet is subjected to 170 to 2
It can be obtained by heating at a temperature of about 80 ° C. for about 30 seconds to about 5 minutes, and thus decomposing and foaming the foaming agent.

[0016]

As described above, according to the present invention, a vinyl chloride-based polymer composition containing a radical initiator in addition to a foaming agent is used and foamed. A vinyl chloride resin foamed leather that is chemically crosslinked and thus has a high foam, a soft leather-like soft feel, high elasticity, and excellent strength be able to. Therefore, such a vinyl chloride resin foamed leather can be suitably used, for example, as a shoe upper material or a bag material.

[0017]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited by these examples. Examples 1-3 (Production of films A-1, A-2 and A-3) Polyvinyl chloride having an average degree of polymerization of 2500, plasticizer (di-2-
Ethylhexyl phthalate), azoisobutyronitrile, Ba-Zn-based stabilizer, filler, dicumyl peroxide and azodicarbonamide are kneaded at the ratios shown in Table 1, and a calendering method using an inverted L-type four-calender Was formed into a film having a thickness of 100 .mu.m, and at the same time, while the film was at a high temperature, the film was adhered to the adhesive surface of an all-floor 79 (foam # 79) to which paste was previously applied and wound up. (Production of Film B) Table 1 shows polyvinyl chloride having an average degree of polymerization of 1300, a plasticizer (di-2-ethylhexyl phthalate), a Ba-Zn stabilizer, a Ca-Zn stabilizer and an epoxidized soybean oil. In the same manner as described above, a film having a thickness of 100 μm was formed by a calendering method, and this was laminated on each of the above films, cooled, and wound up. (Production of foamed vinyl chloride resin leather) Next, the laminated film thus obtained was run in a heating furnace at a temperature of 210 ° C. for 2 minutes, and passed through the embossing of Nashiji No. 1 at the outlet of the furnace. Films A-1, A-2 and A-3
As shown in Table 2, foamed vinyl chloride resin leathers as Examples 1, 2 and 3 were obtained. The structure of these foamed leathers is such that a foam of vinyl chloride resin is laminated with an adhesive on a base cloth, and a non-foamed layer of vinyl chloride resin is laminated thereon.

In Table 2, ◎ indicates very good, ○ indicates good, △ indicates slightly bad, and × indicates bad. The foamed leather according to the present invention has an interlayer strength of 1.17 kg / cm width, high elasticity, and a soft wind even though the expansion ratio is 3.0 to 5.1 times. It is suitable for use as, for example, shoe upper materials. Comparative Examples 1 and 2 (Production of films C and D) Polyvinyl chloride having an average degree of polymerization of 2500, plasticizer (di-2-ethylhexyl phthalate), Ba-Zn-based stabilizer, filler (calcium carbonate), nitrile rubber And azodicarbonamide in Table 1
And at the same time, the film was molded into a film having a thickness of 100 μm by a calendering method using an inverted L-type four calender. Laminated and rolled up. (Production of Film B) (Same as above) (Production of Foamed Vinyl Chloride Resin) Next, each laminated film thus obtained was run in a heating furnace at a temperature of 210 ° C. for 2 minutes. At the exit of No. 1, the embossing of Nashiji No. 1 was passed to obtain vinyl chloride resin foamed leathers as Comparative Examples 1 and 2, respectively, as shown in Table 2, corresponding to the films C and D.

[0019]

[Table 1]

[0020]

[Table 2]

The foamed leathers according to Comparative Examples 1 and 2 do not have a soft feel and a firm feel, and are not suitable for use as, for example, a shell material. The foamed leather according to Comparative Example 3 is inferior in weather resistance and significantly deteriorates. Further, the stability of the vinyl chloride compound E is poor, and it is not practical from the viewpoint of processing.

Claims (5)

(57) [Claims] 1. A process for producing a foamed vinyl chloride resin leather, comprising laminating a composition containing a radical initiator together with a vinyl chloride polymer, a plasticizer and a foaming agent on a substrate and foaming the composition under normal pressure. 2. The method of claim 1, wherein the radical initiator is an organic peroxide. 3. The method for producing a foamed vinyl chloride resin leather according to claim 1, wherein the radical initiator is an azobis compound. 4. 100 parts by weight of a vinyl chloride polymer and 0.1 to 5 parts by weight of an organic peroxide and / or 0.1 to 5 parts by weight of an azobis compound.
A method for producing a foamed vinyl chloride resin leather, comprising laminating a composition containing 20 parts by weight, a plasticizer and a foaming agent on a substrate and foaming the composition under normal pressure. 5. The vinyl chloride polymer has an average degree of polymerization of 2,000.
The method for producing a foamed vinyl chloride resin leather according to claim 1, comprising: