JP2700603B2 - Vinyl chloride resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride resin composition for the purpose of recycling hard vinyl chloride resin molded products.

[0002]

2. Description of the Related Art Vinyl chloride resin is widely used as a material for molded articles such as daily necessities and plumbing equipment, but the waste is conventionally pulverized and reused by injection molding, extrusion molding, extrusion casting molding and the like. Have been.

[0003]

However, although the pulverized vinyl chloride resin is excellent in mechanical properties and weather resistance, it is easily thermally decomposed, so that it is difficult to obtain good fluidity by heating it to a high temperature. Poor molding workability, especially when extrusion molding is performed at a low shear rate in order to obtain a large thick molded product, a streak-like pattern (flow mark) due to unmelted pulverized material enters the surface of the molded product Significantly reduces the appearance and mechanical properties of the molding.

[0004] In order to improve molding workability, it is usual to add stabilizers, lubricants, etc., but since these additions are made by heating and softening the vinyl chloride resin, the vinyl chloride resin is decomposed. It is difficult to perform uniform mixing with low-temperature heating to such an extent that heating is not performed, and molding workability is not sufficiently improved.

[0005]

According to the present invention, as a means for solving the above-mentioned conventional problems, the following components (1), (2) and (3) are added to a pulverized product of a hard vinyl chloride resin molded product. Are mixed. (1) a copolymer of vinyl chloride and another vinyl monomer copolymerizable with the vinyl chloride (2) a low polymerization degree vinyl chloride resin having an average degree of polymerization of 600 or less (3) the above copolymer and the above Mixture with low polymerization degree vinyl chloride resin

[0006] The vinyl chloride resin molded article to be used in the present invention is particularly limited to a hard one, and it is desirable that the surface hardness of the molded article specified in JIS-K6301 is 90 or more. In the case of a pulverized molded product having a surface hardness of less than 90, the melting point of the pulverized product is significantly different from that of the above-mentioned copolymer.

[0007] Other vinyl monomers copolymerizable with vinyl chloride used in the copolymer include olefins such as ethylene, propylene and isobutylene, butadiene,
Dienes such as isoprene, vinylidene chloride, vinyl halides such as vinyl fluoride, methyl acrylate, ethyl acrylate, butyl acrylate, acrylates such as 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, Methacrylic esters such as butyl methacrylate, 2-ethylhexyl methacrylate,
Examples thereof include vinyl esters of saturated monocarboxylic acids such as vinyl acetate and vinyl propionate. Two or more vinyl monomers may be copolymerized.

[0008] Among the above-mentioned vinyl monomers, desirable are:
The melt is a vinyl monomer that provides a polymer with better fluidity than the vinyl chloride polymer melt. By copolymerization with such a vinyl monomer, the melt of the above copolymer has better fluidity than the vinyl chloride resin melt. The vinyl monomer is preferably copolymerized in an amount of 1% by weight or more in the copolymer, and if the amount is less than 1% by weight, good fluidity of the copolymer melt cannot be substantially expected. .

[0009] The melt of the low polymerization degree vinyl chloride resin also has better fluidity than the melt of the ground product of the rigid vinyl chloride resin molded article.

The above-mentioned copolymer, the above-mentioned low polymerization degree vinyl chloride resin, or a mixture of the above-mentioned copolymer and the above-mentioned low polymerization degree vinyl chloride resin is added to 100 parts by weight of the above-mentioned pulverized hard vinyl chloride resin molded product. 5 to 500 parts by weight. If the amount of the copolymer, or the low polymerization degree vinyl chloride resin, or the mixture thereof is less than 5 parts by weight, the molding workability of the pulverized product is not sufficiently improved, and 500 parts by weight If it exceeds, the utilization rate of the above-mentioned pulverized material becomes low, and the heat resistance of the obtained molded product is not sufficient.

[0011]

Since the copolymer of the present invention is a vinyl chloride copolymer, the copolymer of the present invention is less than the melt of a crushed vinyl chloride resin molded product.
A polymer that is more compatible with pulverized hard vinyl chloride resin molded products than other resins that give a good fluidity melt , and the melt is more fluid than a vinyl chloride polymer melt If the vinyl monomer to be provided is copolymerized, the melt of the copolymer has better fluidity than the melt of the pulverized product. The vinyl chloride resin having a low degree of polymerization is also naturally compatible with the above-mentioned pulverized product, and the melt thereof has better fluidity than the vinyl chloride polymer melt.

[0012]

The present invention will be described in detail with reference to the following examples, but these examples do not limit the present invention.
As a pulverized hard vinyl chloride resin molded product, commercially available soy sauce bottles (hardness 105, JIS-K630)
1) is collected, washed and washed with water, and about 1
A chip in the order of cm was used. In each of Examples and Comparative Examples, a copolymer (vinyl chloride-ethylene copolymer PVC / PE) or a low polymerization degree vinyl chloride resin was used as shown in Table 1 for the above-mentioned pulverized hard vinyl chloride resin molded product. Alternatively, these mixtures were mixed, and the mixed compound was extruded with a 65 mmφ single-screw extruder to extrude a resin, poured into a U-shaped trough mold, injected, and press-molded to obtain a molded product. A test piece was prepared by cutting from this molded product, and its physical properties were measured. Table 1 shows the results.

[Table 1]

According to Table 1, all of Examples 1 to 3 using the composition of the present invention have sufficient mechanical strength, good molding workability, and good molded product surface properties. In Comparative Example 1 in which the copolymer of the present invention or the vinyl chloride resin having a low degree of polymerization was not mixed, or Comparative Examples 2 to 4 in which even if they were mixed, the mixing amount was less than the limit value of the present invention, the molding workability and molding Insufficient surface properties.

[0014]

As described above, according to the present invention, a rigid vinyl chloride resin molded article can be effectively reused.

Claims (1)

(57) [Claims] 1. A pulverized product of a hard vinyl chloride resin molded product 10
0 to 5 parts by weight of a copolymer of vinyl chloride and another vinyl monomer copolymerizable with the vinyl chloride, or a low-polymerization degree vinyl chloride resin 5 having an average degree of polymerization of 600 or less.
-500 parts by weight, or 5 to 500 parts by weight of a mixture of the copolymer and the low-polymerization degree vinyl chloride resin.