JPH0629349B2 - Vinyl chloride resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention is a molding having excellent so-called non-migration property in which a plasticizer does not migrate from the inside of a molded article even under conditions of high temperature and high humidity and having heat aging resistance. The present invention relates to a vinyl chloride resin composition capable of giving a product.

"Prior Art" Vinyl chloride resin can be changed in its physical properties in an extremely wide range by blending a plasticizer, and is widely used industrially as a thermoplastic resin suitable for various applications. As the plasticizer for vinyl chloride resin, phthalic acid esters such as dioctyl phthalate and fatty acid esters such as dioctyl adipate are the most common because of their excellent plasticizing efficiency. However, these plasticizers have a large property of migrating from the inside of the molded article to the surface, and the molded article containing this not only causes deterioration of the physical properties due to the decrease of the plasticizer, but also the molded article and other molded articles. When the resin molded product is brought into contact with the resin molded product for a long time, the plasticizer migrates to another resin molded product, which causes deterioration and deterioration of the resin molded product. For the purpose of non-migration, use or combination of a trimellitic acid ester plasticizer or a liquid polyester plasticizer obtained by polycondensation of adipic acid and ethylene glycol, 1,3-butanediol, etc. has been attempted. However, although the migration property is improved to some extent, it is difficult to say that it is not completely non-migration under various conditions, for example, in an environment of high temperature and high humidity, and these plasticizers are expensive and have the plasticization efficiency described above. It is significantly inferior to that of the above-mentioned products, and if it is attempted to obtain the same degree of plasticization efficiency, a large amount of high-priced products must be used, which is economically disadvantageous. Other adverse effects due to the addition of the plasticizer occur, and it cannot be a general-purpose plasticizer.

For the purpose of preventing migration of the plasticizer, a polymer compound having flexibility in plasticizing a vinyl chloride resin, for example, ethylene-vinyl acetate copolymer, ethylene-carbon monoxide-vinyl acetate copolymer, thermoplastic polyurethane, Attempts have been made to blend NBR and the like into a vinyl chloride resin, but even a vinyl chloride resin plasticized with such a polymer compound is slightly different from the liquid plasticizer migration, When another resin molded product comes into contact with the molded product produced from the composition, in a severe environment such as high temperature and high humidity, the surface of the other resin molded product is contaminated by the bloom from the molded product, and the liquid plasticizer A phenomenon similar to migration (hereinafter, this phenomenon is also referred to as “migration”) occurred, and migration could not be completely avoided.

Among these polymer plasticizers, poly-ε-caprolactone has good hydrolysis resistance and relatively excellent non-migration property in a severe environment of high temperature and high humidity. However, poly- [epsilon] -caprolactone has strong crystallinity and has a problem that its hardness changes with time and, for example, its transparency is lost as disclosed in Japanese Patent Laid-Open No. 60-90208.

On the other hand, the present inventor previously found that Japanese Patent Application No. 59-18483.
In No. 0, a proposal was made to reduce the crystallinity of poly-ε-caprolactone by modifying it with a diol and a dicarboxylic acid.

However, the reduction of the crystallinity of poly-ε-caprolactone is not sufficient even by the modification with a diol and a dicarboxylic acid, and the modified poly-ε-caprolactone is used for the purpose of improving the non-migration property.
Even if an attempt was made to increase the molecular weight of caprolactone, the oligomer component was increased, and the non-migration property was not improved so much.

"Problems to be Solved by the Invention" In view of the above circumstances, the present inventors have sought to obtain a vinyl chloride resin composition having excellent non-migratory property even under high temperature and high humidity conditions and having heat aging resistance. As a result of earnest studies, among the lactone polymers, particularly liquid poly-β-methyl-δ
-By adding valerolactone to a vinyl chloride resin, it was found that it is possible to solve problems such as hardness change and transparency change which are problems when the ε-caprolactone polymer is added to the vinyl chloride resin. The invention was completed.

"Means for Solving Problems" The gist of the present invention is to provide 100 parts by weight of a vinyl chloride resin produced by a suspension polymerization method or a bulk polymerization method, which contains at least 70% by weight of vinyl chloride, Liquid poly-β-methyl-δ having a weight average molecular weight of 3000 or more
-A vinyl chloride resin composition comprising 25 parts by weight or more and 400 parts by weight or less of valerolactone.

The present invention will be described in detail below.

As the vinyl chloride resin used in the composition of the present invention, a resin produced by a suspension polymerization method or a bulk polymerization method from vinyl chloride or a mixture of vinyl chloride and a comonomer copolymerizable therewith is used. The polymerization may be carried out in the presence of the polyester resin described below. Thus, as the comonomer copolymerizable with vinyl chloride, for example, vinyl acetates such as vinyl acetate, vinyl propionate and vinyl laurate, acrylic acid esters such as methyl acrylate, ethyl acrylate and butyl acrylate,
Methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, maleic acid esters such as dibutyl maleate and diethyl maleate, fumaric acid esters such as dibutyl fumarate and diethyl fumarate, vinyl methyl ether, vinyl butyl ether, vinyl octyl ether. Vinyl ethers such as, acrylonitrile, vinylated cations such as methacrylonitrile, α-olefins such as ethylene, propylene and styrene, vinylidene chloride, vinyl halides other than vinyl chloride such as vinyl bromide, and the like. The comonomer is 30% by weight or less, preferably 20% by weight in the constituent components of the vinyl chloride resin.
It is used in the range of not more than wt%. Of course, the comonomer is
It is not limited to the above.

Liquid poly-β-methyl-δ which is one component of the present invention
-Valerolactone is a product of G.I. P. The weight average molecular weight measured by C must be 3000 or more.

Poly-β-methyl-δ-valerolactone has an asymmetric carbon, is low in crystallinity, and becomes liquid even at a high molecular weight, and thus is significantly advantageous as compared with a polymer obtained from other lactone compounds. .

Poly-β-methyl-δ-valerolactone is a hydroxycarboxylic acid having the corresponding number of carbon atoms, 3-methyl-5-hydroxyl-, which is also obtained by ring-opening polymerization of β-methyl-δ-valerolactone. It can also be obtained by polycondensation of herb acid.

When the weight average molecular weight of the liquid poly-β-methyl-δ-valerolactone is less than 3000, the non-migratory property is not sufficient like the ordinary polyester plasticizer obtained by polycondensing a diol and a dicarboxylic acid. From the viewpoint of non-migratory property, it is desirable that the liquid poly-β-methyl-δ-valerolactone has a large molecular weight, but on the other hand, when the molecular weight becomes large, not only the ability to plasticize the vinyl chloride resin decreases, but also Since the production cost of liquid poly-β-methyl-δ-valerolactone increases, it is economically disadvantageous.
Advantageously, it is below 0,000.

Therefore, the composition ratio of the vinyl chloride resin and the liquid poly-β-methyl-δ-valerolactone varies depending on various requirements such as the degree of plasticization of the vinyl chloride resin and the use of the vinyl chloride resin composition. However, the latter may be appropriately determined from the range of 25 to 400 parts by weight with respect to the former 100 parts by weight.

When the amount of liquid poly-β-methyl-δ-valerolactone is less than 25 parts by weight, it is difficult to prepare a composition in which a vinyl chloride resin is plasticized, while when it is more than 400 parts by weight, a vinyl chloride composition is used. It becomes difficult to maintain the shape of the object.

The composition of the present invention is a vinyl chloride resin, liquid poly-β.
-Methyl-δ-valerolactone, if necessary,
Stabilizers, colorants, foaming agents, cross-linking agents, fillers and the like can be contained.

"Action and Effect" The vinyl chloride resin composition of the present invention is a liquid poly-β-
Since methyl-δ-valerolactone is used as a plasticizer for vinyl chloride-based resin, it is excellent even in the environment of high temperature and high humidity even when other resin molded products come into contact with the molded product obtained from the composition. It does not migrate, and since it does not contain a plasticizer with a low molecular weight, it does not cause a phenomenon such as extraction of the plasticizer. Therefore, the hardness of the molded product does not change with time, and the heat aging resistance Is also good. Therefore, the composition of the present invention, automobile interior materials, medical films or tubes,
Highly useful as a material for packing, wire coating, etc.

"Example" Next, the vinyl chloride resin composition of the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist.

Example 1 100 parts by weight of vinyl chloride resin (average degree of polymerization = 1300) was added to poly-β-methyl-δ-valerolactone (Mw =
12,000) 60 parts by weight, stearic acid 0.3 parts by weight, calcium carbonate 10 parts by weight, Ba-Zn stabilizer 3
1 part by weight is blended, and the blend is roll-kneaded at 160 ° C. for 5 minutes to obtain a roll sheet having a thickness of 0.6 mm.
It was used for evaluation of hardness change and heat aging resistance. The results are summarized in Table 1.

Example 2 A roll sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of poly-β-methyl-δ-valerolactone was used.
It was used for evaluation of migration property, hardness change, and heat aging resistance.

Example 3 A roll sheet was obtained in the same manner as in Example 1 except that the vinyl chloride resin was changed to an average degree of polymerization of 2300, and the roll sheet was evaluated for migration, hardness change, and heat aging resistance.

Comparative Example 1 Evaluation was performed in the same manner as in Example 1 except that the polyester resin in Example 1 was poly-ε-caprolactone (Mw = 40,000).

COMPARATIVE EXAMPLE 2 The procedure of Example 1 was repeated except that 80% by mol of ε-caprolactone, 10% by mol of neopentyl glycol and 10% by mol of isophthalic acid were copolycondensed as the polyester resin (Mw = 8,000). Example 1
It evaluated similarly to.

Comparative Example 3 Evaluations were performed in the same manner as in Example 1 except that the weight average molecular weight of poly-β-methyl-δ-valerolactone was changed to 1800.

The evaluation method is as shown below.

<Transition property> A plurality of sheets obtained in Examples and Comparative Examples are stacked 16
Pressed at 0 ℃, 100kg / cm ² for 5 minutes, thickness 3mm
Was formed, and a test piece having a width of 2 mm and a length of 50 mm was cut out from this pressed sheet, and the migration property was evaluated under two conditions of dry and wet. Dry conditions and wet conditions are as follows.

Dry conditions: Polystyrene sheet, ABS sheet, metallic coating sheet, each with a test piece overlaid, sandwiched between glass plates, 30
After being left in an oven at 60 ° C. for 7 days under a load of 0 gr, the test piece was peeled off and the surface condition of each sheet was examined.

Wet condition: After leaving the test piece alone in an oven adjusted to a temperature of 80 ° C. and a humidity of 90% for 12 days, the test piece was taken out, and the test piece was further tested by the same method as in the dry condition. The surface condition of each of the sheet and the metallic coated sheet was examined.

The evaluation criteria were marked with ⊚ when no visible change in the surface condition was observed, and were evaluated in order of 4 grades from good to good.

<Hardness change> By using the sheet created for the migration test, JIS K6
The hardness was measured according to 301. Further, the hardness of the sheet after standing at 25 ° C. for 3 months was measured.

<Heat aging resistance> Sheets having a thickness of about 0.6 mm prepared for the migration test were stacked and pressed at 160 ° C. under 100 kg / cm ² for 5 minutes to obtain a pressed sheet having a thickness of 1 mm. The sheet is JIS K6
According to the post-heating tensile test of 723, the residual rate of tensile strength and the residual rate of elongation were determined. However, the heating condition of the sheet is 120 ° C.
And the heating temperature was made stricter than the specified heating temperature.

Claims (1)

[Claims] 1. A liquid poly-containing resin having a weight average molecular weight of 3000 or more based on 100 parts by weight of a vinyl chloride resin containing at least 70% by weight of vinyl chloride and produced by a suspension polymerization method or a bulk polymerization method. A vinyl chloride resin composition comprising 25 parts by weight or more and 400 parts by weight or less of β-methyl-δ-valerolactone.