JPH06220281A - Vinyl chloride resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in heat resistance and thermal stability and hence suited for use as a molding material for producing plates, pipes, sheets, containers, etc., required to have these properties. CONSTITUTION:This resin composition comprises 100 pts.wt. vinyl chloride resin and 5-100 pts.wt. water-insoluble polymer obtained from a radical- polymerizable monomer and having an SH group at one of its ends.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a vinyl chloride resin composition having excellent thermal stability.

[0002]

2. Description of the Related Art Vinyl chloride resin has mechanical strength, weather resistance,
It has excellent physical properties such as chemical resistance and self-extinguishing property, and is widely used for pipes, plates, films, sheets, containers, etc., but it has a low softening temperature and poor thermal deformation resistance. Hard vinyl chloride resin generally causes thermal deformation at 70 to 80 ° C., and therefore cannot be used at temperatures higher than that.

Various methods have been proposed in order to improve the heat distortion resistance, for example, vinyl chloride-N-allyl maleimide copolymer and the like. Although this copolymer has improved heat resistance and excellent fluidity, it has the drawback of being poor in thermal stability and being easily dehydrochlorinated during heat molding.

In order to improve the above thermal stability,
Although it has been proposed to add an organotin stabilizer, a lead stabilizer, a violite compound, or the like, thermal stability is still insufficient.

Further, in JP-A-2-276847, a vinyl chloride resin, a methyl methacrylate component, N
Selected from the group consisting of alkyl acrylate esters, methacrylic acid alkyl esters, aromatic vinyl compounds and vinyl cyanide compounds in the presence of a copolymer containing a substituted maleimide component and an aromatic vinyl component or an elastomer containing a conjugated diene component. Although a method of blending a copolymer obtained by graft-polymerizing one or more monomers has been proposed, impact resistance is improved but thermal stability is still insufficient.

[0006]

In view of the above drawbacks, an object of the present invention is to provide a vinyl chloride resin composition having excellent heat resistance and heat stability.

[0007]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned objects, the present inventors have found that 100 parts by weight of vinyl chloride resin (A) is composed of a radically polymerizable monomer. The present invention has been completed by finding a vinyl chloride resin composition comprising 5 to 100 parts by weight of a water-insoluble polymer (B) having an SH group at one end.

The component (B) used in the present invention is
It is composed of a structural unit derived from one or more radically polymerizable monomers, and the structural unit is, for example,
(Meth) acrylic acid esters, vinyl esters, aromatic vinyl, maleimide compounds and the like can be mentioned.

Of the above radical-polymerizable monomers,
As the (meth) acrylic acid esters, those in which the carbon number of the alkyl group is usually 1 to 22 are preferable, and specific examples thereof include methyl (meth) acrylate, ethyl (meth) acrylate, and (meth) acrylic acid. Butyl, tert-butylcyclohexyl (meth) acrylate, amyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate,
Lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth)
Examples thereof include benzyl acrylate.

Examples of vinyl esters include vinyl formate, vinyl acetate, vinyl propionate, vinyl versatate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl palmitate, vinyl stearate and olein. Examples thereof include vinyl acetate and vinyl pivalate.

Examples of the aromatic vinyl include styrene, α-methylstyrene, o-chlorostyrene, p-chlorostyrene and vinyltoluene.

As the maleimide compound, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-tert-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, Examples thereof include N-hydroxyphenyl maleimide and N-lauroyl maleimide.

Monomers other than the above are (meth) acrylic acid, (meth) acrylic acid amide, vinyl ether,
Aromatic vinyl, maleimide compound, unsaturated dicarboxylic acid (anhydride), vinyl cyanide, vinylpyrrolidone, α-
Various things such as olefill are possible.

As the unsaturated dicarboxylic acid anhydride, maleic anhydride, chloromaleic acid anhydride, dichloromaleic acid anhydride, citraconic acid anhydride, itaconic acid anhydride,
Examples thereof include phenyl maleic anhydride and aconitic anhydride.

Examples of vinyl cyanide include acrylonitrile, methacrylonitrile, and α-chloroacrylonitrile, and acrylonitrile is particularly preferable.

The polymer of component (B) used in the present invention must be water-insoluble. Therefore, among the above-mentioned monomers, those that become water-soluble by hydrolysis or the like preferably have a degree of hydrolysis of 50 mol% or less. Also the component (B)
The polymer may have a graft structure.

The degree of polymerization of the water-soluble polymer (B) used in the present invention is not particularly limited, but its average degree of polymerization (Pn) is preferably 5000 or less.

The method for producing the water-insoluble polymer (B) is not particularly limited, and those produced by various methods can be applied. However, when radical-polymerizing the monomers among them, the polymerization is performed in the coexistence of a compound containing a thioester and a thiol group in the molecule such as thiolcarboxylic acid or 2-acetylthioethylthiol and 10-acetylthiodecanethiol. The method of treating the obtained polymer with an alkali such as sodium hydroxide or ammonia to obtain a polymer having a thiol group at one end is simple and efficient, and is most preferable.

In addition to the vinyl chloride resin (A) and the water-insoluble polymer (B), various vinyl components may be added to the vinyl chloride resin composition of the present invention, if necessary. Examples of the rubber component used here include polybutadiene, styrene-butadiene block polymer, nitrile rubber, maleated rubber, polyisoprene rubber, butadiene-acrylonitrile rubber, ethylene-propylene-diene terpolymer, butadiene-styrene-butadiene polymer, butadiene- Examples include isoprene-butadiene polymer.

The constitution of the vinyl chloride resin composition of the present invention is as described above, and calcium stearate, zinc stearate, barium stearate, cadmium stearate, which are used as stabilizers for vinyl chloride resins, Metallic soaps such as lead stearate, dibasic sulfates, dibasic lead stearate, calcium hydroxide, inorganic stabilizers such as calcium silicate, lubricants, pigments, fillers, impact modifiers, processing aids, An ultraviolet absorber or the like may be added.

[0021]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples. In the following, "parts" and "%" mean "parts by weight" and "% by weight", respectively.

Examples 1 to 9 A vinyl chloride resin (A) was blended with a water-insoluble polymer (B) having an SH group at one end shown in Table 1 and various additives shown below, This was mixed with a mixer and kneaded with a roll at 180 ° C. for 3 minutes to obtain a sheet. The obtained sheet was supplied to a gear oven at 185 ° C., and the time until blackening (aging blackening time) was measured.
Further, the obtained sheet is supplied to a press molding machine,
Press molding was carried out for 5 minutes under conditions of ℃ and 75 kg / cm ² to obtain a molded plate. The Vicat softening temperature of the obtained molded plate was measured. The results are shown in Table 3.

Comparative Examples 1 to 5 Compositions obtained by blending the water-insoluble polymer (B) having an SH group at one end with the polymer having no SH group shown in Table 2 in the formulation of the above Examples. A sheet was obtained under the same conditions as in the above example, the blackening time of the sheet was measured, a press-molded plate of the sheet was molded, and the Vicat softening temperature was measured. The results are shown in Table 3 together with the results of the examples.

<< Compound and its composition >> Addition amount Vinyl chloride resin (degree of polymerization: 1050) 100 parts Water-insoluble polymer (see Table 1) Lubricant (Hoechst-Wax OP) 0.5 Part lead stearate 0.8 part barium stearate 0.6 part 3 basic lead sulfate 1.8 parts

[0025]

[Table 1]

[0026]

[Table 2]

MMA: methyl methacrylate BA: butyl acrylate MA: methyl acrylate 2EHA: 2-ethylhexyl acrylate VAc: vinyl acetate PVi: vinyl pivalate St: styrene EVA: ethylene-vinyl acetate

[0028]

[Table 3]

[0029]

As is apparent from the above examples, the vinyl chloride resin composition of the present invention is excellent in heat resistance and heat stability. Therefore, it can be suitably used as a material for forming a plate, a pipe, a sheet, a container or the like which requires these characteristics.

Claims (1)

[Claims] 1. To 100 parts by weight of vinyl chloride resin,
A vinyl chloride resin composition comprising a radically polymerizable monomer and 5 to 100 parts by weight of a water-insoluble polymer having an SH group at one end.