JPH03115449A - Vinyl chloride resin composition - Google Patents

Abstract

PURPOSE:To prepare a vinyl chloride resin compsn. excellent in the thermal stability and impact resistance by compounding a specific resin compsn. and a vinyl chloride resin each in a specified amt. CONSTITUTION:100 pts.wt. (solid resin base) graft copolymer latex obtd. by graft copolymerizing a vinyl compd. (e.g. methyl methacrylate or styrene) onto a diene or acrylic ester rubber polymer (e.g. a butadiene-styrene copolymer) is mixed with an emulsion contg. 0.01-10 pts.wt. stabilizer {e.g. di-n-octyltin bis(iso-octyl mercaptoacetate)} for preventing the thermal degradation of a vinyl chloride resin having an m.p. of 90 deg.C or lower. The latex is then coagulated to give a resin compsn. 3-30wt.% resulting compsn. and 97-70wt.% vinyl chloride resin are compounded to give the title compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vinyl chloride resin composition having excellent thermal stability and impact resistance.

[Prior art] Vinyl chloride resin has excellent transparency and low air permeability.
Moreover, although it is inexpensive, it has the disadvantages of poor impact resistance and poor thermal stability during molding.

Therefore, as a method of improving the impact resistance, so-called MB, which is made by graft copolymerizing diene rubber with methyl methacrylate, styrene, acrylonitrile, etc.
A method has been adopted in which a so-called acrylic reinforcing agent, which is obtained by graft copolymerizing S, ABS resin or acrylic ester rubber with methyl methacrylate, styrene, acrylonitrile, etc., is mixed with vinyl chloride resin.

In addition, as a method for preventing thermal deterioration during the molding process,
For vinyl chloride resins, stabilizers such as tin mercaptide, calcium stearate, and zinc stearate are used.

By the way, vinyl chloride resin compositions are generally provided as molded products such as sheets and bottles processed by molding methods such as calendar molding and extrusion molding. In these molding methods, a major point is how to improve industrial productivity, but in order to shorten the time required for the molding cycle and improve productivity, the resin temperature must be raised. The molded product may turn yellow and lose its value as a product. For this reason, in practice, more stabilizers have been added to vinyl chloride resins than before, but there are problems such as an increase in the cost of molded products and precipitation of the stabilizer from molded products.

[Problems to be Solved by the Invention] In view of the above-mentioned prior art, the present invention was made for the purpose of finding a vinyl chloride resin composition that has excellent thermal stability and impact resistance with a small amount of stabilizer. It is something.

[Means for Solving the Problems] The present invention provides a graft copolymer latex obtained by graft copolymerizing a diene-based or acrylic acid ester-based rubbery polymer with a vinyl group-containing compound. On the other hand, the melting point of vinyl chloride resin to prevent thermal deterioration is 9.
An emulsion containing 0.01 to 10 parts by weight of a stabilizer having a temperature of 0°C or lower is added to the graft copolymer latex, and then coagulated to obtain a resin composition of 3 to 30 parts by weight and a vinyl chloride resin. The present invention relates to a vinyl chloride resin composition containing 97 to 70% by weight and having excellent thermal stability and impact resistance.

[Function and Examples] The graft copolymer used in the present invention is produced by producing a rubbery polymer as a backbone polymer by a normal emulsion polymerization method, and then graft copolymerizing a vinyl group-containing compound that can be copolymerized with the rubbery polymer. It can be obtained by making

As the rubber component of the rubbery polymer used as the backbone polymer, for example, diene monomers such as butadiene, isoprene, and chlorobrene, and alkyl acrylate monomers such as butyl acrylate and octyl acrylate are used. These diene monomers and alkyl acrylate monomers can also be used in combination. Furthermore, the monomer may be copolymerized with other copolymerizable monomers. Specific examples of such copolymerizable monomers include methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, vinyl cyanides such as acrylonitrile and methacrylonitrile, and aromatic vinyls such as styrene and α-methylstyrene. and vinyl halides such as vinyl chloride and vinyl bromide. Examples of polymerization methods for the monomers include polymerization using divinylbenzene, monoethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, etc. as a crosslinking agent, but the present invention is limited to such polymerization methods. It is not something that will be done.

The vinyl group-containing compound to be graft copolymerized with the rubbery polymer includes monomers copolymerizable with the rubbery polymer, such as methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, ethyl acrylate, These include acrylic esters such as butyl acrylate, vinyl cyanides such as acrylonitrile and methacrylonitrile, aromatic vinyls such as styrene and α-methylstyrene, and vinyl halides such as vinyl chloride and vinyl bromide. The vinyl group-containing compound may be used alone or with 2f
11i or more are used in combination. In addition, in the present invention, divinylbenzene, monoethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, etc. can be further used as a crosslinking agent.

The graft copolymer obtained by the graft copolymerization has a rubbery polymer content of 5 to 85% and <25 to 8%.
0% by weight and 15-95% by weight of vinyl group-containing compounds,
It is preferable that the content is <20 to 75% by weight.

In the graft copolymer, if the proportion of the rubbery polymer is less than 5% by weight, the impact resistance tends to be insufficiently improved, and if it exceeds 85% by weight,
It becomes agglomerated during the coagulation stage or drying stage, making it difficult to mix uniformly with the vinyl chloride resin, which tends to cause variations in the physical properties of the resulting molded product.

The stabilizer used in the present invention has a melting point of 90° C. or lower for preventing thermal deterioration of vinyl chloride resin. The stabilizer is emulsified into fine droplets and then added to the graft copolymer latex.

If the melting point of the stabilizer exceeds 90°C, the stabilizer tends to precipitate from the emulsion, so it is desirable that the melting point is 90°C or lower, preferably 80°C or lower. Specific examples of the stabilizer include di-n-octyltin bis(isooctylmercaptoacetate), di-n-butyltin dilaurate, and di-n-octyltin dilaurate, which are used as so-called tin-based stabilizers. Organotin compounds such as butyltin bismaleate salts, compounds having a β-dicarbonyl group (hereinafter referred to as β-dicarbonyl (compounds), etc. In addition to the above-mentioned stabilizers, there are also stabilizers such as epoxidized soybean oil that have the effect of improving thermal stability when added to graft copolymer latex and coagulated. If soybean oil or the like is added, the effect is small, so it is necessary to add a large amount. The epoxidized soybean oil exhibits a plasticizing effect, so it can be used, for example, in fish.
It can also be used to reduce eye appearance.

The amount of the stabilizer used is 0 to 100 parts (parts by weight, same hereinafter) of the resin solid content in the graft copolymer latex.
．． 01 to 10 parts, preferably 0.1 to 5 parts. If the amount used is less than 0.01 part, the improvement in thermal stability tends to be insufficient, and if it exceeds 10 parts, the powder properties of the resin tend to deteriorate. The stabilizer may be added alone to the graft copolymer latex, or may be added to the graft copolymer latex in combination with an antioxidant that is usually added.

The stabilizer is usually added to the graft polymer latex as an emulsion. The composition of such an emulsion is not particularly limited, and examples include 0.01 to 10 parts of the stabilizer, 7ko, 02 to 20 parts of the stabilizer per 100 parts of resin solid content in the graft copolymer latex. Examples include emulsions containing 0.005 to 5 parts of emulsifier and 0.005 to 5 parts of emulsifier. Specific examples of the emulsifier include sodium oleate, potassium stearate, potassium rosinate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, etc., but the present invention is not limited only to these examples. .

Next, the mixture of the graft copolymer latex and the emulsion is solidified by salting out or acid precipitation to obtain a resin composition, which is usually filtered and then dried to be used as a resin powder.

The vinyl chloride resin composition of the present invention can be obtained by blending the resin composition and the vinyl chloride resin, and the amount of the resin composition blended in the vinyl chloride resin composition obtained is 3 to 3. 30% by weight, preferably 5-25% by weight26
, and the blending amount of the vinyl chloride resin is 97 to 70% by weight, preferably 9% by weight in the vinyl chloride resin composition obtained.
It is desirable that the content be adjusted to 5 to 75% by weight. If the blending amount of the resin composition is less than 3% by weight, the impact resistance tends to be insufficient;
If it exceeds , heat resistance tends to decrease.

The vinyl chloride resin used in the present invention is, for example, 50 to 100% by weight, preferably 80 to 100% by weight.
of vinyl chloride monomer and 0 to 50% by weight, preferably 0 to 50% by weight, preferably 0 to 50% by weight of vinyl chloride monomer.
Examples include polymers obtained by polymerizing 20% by weight of other copolymerizable monomers, such as ethylene, propylene, acrylic esters, vinyl esters such as vinyl acetate, and vinyl ethers.

The vinyl chloride resin composition of the present invention thus obtained is
Since it has excellent thermal stability and impact resistance, it is used as molded products such as sheets and bottles by molding methods such as calendar molding and extrusion molding.

In addition, the vinyl chloride resin composition of the present invention may contain, for example, processing aids, ultraviolet absorbers, fillers, antistatic agents, etc. within a range that does not impede the physical properties aimed at by the present invention. .

Next, the vinyl chloride resin composition of the present invention will be explained in more detail based on Examples, but the present invention is not limited only to these Examples. In addition, in each example and comparative example, both "part" and "%" are based on weight.

Example 1 Production of a rubber-like polymer Raw materials having the following composition were charged into an autoclave equipped with a stirrer which had been sufficiently nitrogen-substituted, and reacted with stirring at 40°C for 15 hours.

(Composition of raw materials) (Part) Water
200
Butadiene 75 Styrene
25 Polyethylene glycol dimethacrylate 1 Ferrous sulfate superhydrate salt 0. OOG Ethylenediaminetetraacetic acid Thorium acetate 0,01.5 Sodium formaldehyde sulfoxylate 0.5 Sodium oleate 2.5 The average particle size of the obtained rubbery polymer latex is 85n1
1, and the polymerization conversion rate was 98%.

(B) Production of graft copolymer While performing nitrogen substitution, the following composition was prepared in a glass container and stirred at 60°C.

(Raw material for graft copolymer) (Part) Rubber-like polymer latex obtained in the above figure 60 water
200 Ferrous sulfate/superhydrate salt 0.0015 Disodium ethylenediaminetetraacetate 0.03 Sodium formaldehyde sulfoxylate 0.5 To the mixture obtained above, the following first and second grafting acids were added. The polymerization was carried out by adding the amount in stages.

The first stage was polymerized for 2 hours. Polymerization conversion rate is 98
%Met.

(First stage graft copolymerization component) (Part) Methyl methacrylate 20 Cumene hydroperoxide 0.2 Next, the second stage was polymerized for 3 hours.

The polymerization conversion rate was 96%.

(Second-stage graft copolymerization component) (Part) Styrene 20 Cumene hydroperoxide 0.2 To the thus obtained graft copolymer latex, di-n-octyltin bis( An emulsion consisting of 2.5 parts of isooctyl mercaptoacetate, 5 parts of water and 0.5 parts of sodium oleate was added.

Next, 1 part of phosphoric acid diluted in water is added to this graft copolymer latex to coagulate, and then dehydrated, washed,
After drying, a resin composition was obtained as a white powdered resin.

10 parts of the obtained resin composition, 100 parts of vinyl chloride resin (ffi degree 800), 0.5 parts of di-n-octyltin bis(isooctyl mercaptoacetate) and 1.5 parts of montan acid wax were mixed using a Henschel mixer. , a polyvinyl chloride compound was obtained.

The obtained polyvinyl chloride compound was kneaded with an 8-inch roll at 180°C for 5 minutes, and then pressed at 180°C for 15 minutes to prepare a test piece.

The color tone (b value) of the test piece was measured with a color difference meter (manufactured by Nippon Heavy Industries Ltd., product number: Σ80), and was used as a measure of deterioration of the test piece.

The results are shown in Table 1.

Example 2 The procedure was the same as in Example 1 except that the amount of di-n-octyltin bis(isooctyl mercaptoacetate) added to the graft copolymer latex was changed from 2.5 parts to 5 parts. A test piece was prepared and evaluated. The results are shown in Table 1.

Comparative Example 1 A test piece was prepared in the same manner as in Example 1, except that 2.5 parts of di-n-octyltinbis(isooctylmercaptoacetate) was not added to the graft copolymer latex. It was manufactured and evaluated. The results are shown in Table 1.

Comparative Example 2 In Comparative Example 1, vinyl chloride resin (degree of polymerization 800) 1
A test piece was prepared and evaluated in the same manner as in Comparative Example 1, except that 0.75 part of di-n-octyltinbis(isooctylmercaptoacetate) was used for 0.00 part of the test piece. The results are shown in Table 1.

Comparative Example 3 In Comparative Example 1, vinyl chloride resin (degree of polymerization 80) 1
A test piece was prepared and evaluated in the same manner as in Comparative Example 1, except that 1.0 part of di-n-octyltin bis(in-octyl mercaptoacetate) was used per 00 parts. The results are shown in Table 1.

Table 1 Example 3 A graft copolymer latex was obtained in the same manner as in Example 1. An emulsion containing 0.25 parts of stearoylbenzoylmethane, 5 parts of water, and 0.5 parts of sodium oleate per 100 parts of resin solid content in the latex was added to the obtained graft copolymer latex.

Next, 1 part of phosphoric acid diluted in water was added to this latex, and the mixture was coagulated, followed by dehydration, washing, and drying to obtain a resin composition as a white powdered resin.

10 parts of the obtained resin composition, vinyl chloride resin (polymerization degree [
100), 5 parts of epoxidized soybean oil, 0.5 parts of calcium stearate, 0.15 parts of zinc stearate and 70.1 parts of stearoylbenzoylmeth were mixed in a Henschel mixer to obtain a polyvinyl chloride compound.

The obtained polyvinyl chloride compound was kneaded with an 8-inch roll at 180°C for 5 minutes, and then pressed at 180°C for 15 minutes to prepare a test piece.

The color tone (b value) of the test piece was measured using a color difference meter in the same manner as in Example 1, and was used as a measure of deterioration of the test piece.

The results are shown in Table 2.

Example 4 In Example 3, the amount of stearoylbenzoylmethane added to the graft copolymer latex was 0.25.
A test piece was prepared and evaluated in the same manner as in Example 3, except that the part was changed to 0.5 part. The results are shown in Table 2.

Comparative Example 4 In Example 3, stearoylbenzoylmethane 06
A test piece was prepared and evaluated in the same manner as in Example 3, except that 25 parts was not added to the graft copolymer latex. The results are shown in Table 2.

Comparative Example 5 In Comparative Example 4, vinyl chloride resin (polymerization degree eoo)
A test piece was prepared and evaluated in the same manner as in Comparative Example 4, except that the amount of stearoylbenzoylmethane added to the ioo part was 0.15 parts.

Ta. The results are shown in Table 2.

Comparative Example 6 In Comparative Example 4, vinyl chloride resin (degree of polymerization C0D)
A test piece was prepared and evaluated in the same manner as in Comparative Example 4, except that the amount of stearoylbenzoylmethane added was 0.2 parts per 100 parts.

The results are shown in Table 2.

As is clear from the results shown in Tables 1 and 2,
It can be seen that the vinyl chloride resin composition of the present invention has excellent thermal stability and impact resistance because it contains a specific stabilizer.

[Effects of the Invention] The vinyl chloride resin composition of the present invention has excellent thermal stability and impact resistance, so it can be made into molded products such as sheets and bottles by molding methods such as calendar molding and extrusion molding. It can be suitably used.

Claims (1)

[Scope of Claims] 1. A vinyl chloride resin based on 100 parts by weight of the resin solid content of a graft copolymer latex obtained by graft copolymerizing a vinyl group-containing compound to a diene-based or acrylic acid ester-based rubbery polymer. After adding to the graft copolymer latex an emulsion containing 0.01 to 10 parts by weight of a stabilizer with a melting point of 90°C or less for preventing thermal deterioration of
A vinyl chloride resin composition having excellent thermal stability and impact resistance and containing 3 to 30% by weight of a coagulated resin composition and 97 to 70% by weight of a vinyl chloride resin. 2. The vinyl chloride resin composition according to claim 1, wherein the vinyl group-containing compound is at least one selected from aromatic vinyl, vinyl halide, methacrylate, acrylate, and vinyl cyanide. 3. The vinyl chloride resin composition according to claim 1, wherein the stabilizer is an organic tin compound. 4. The vinyl chloride resin composition according to claim 1, wherein the stabilizer is a β-dicarbonyl compound.