JPS60221447A - Vinyl chloride resin composition of good processability - Google Patents

Abstract

PURPOSE:The titled composition that is composed of polyvinyl chloride, a polymeric plasticizer and a vinyl chloride graft polymer, thus showing good gelling properties and excellent processability. CONSTITUTION:The objective composition is obtained by using (A) 100pts.wt. of polyvinyl chloride, preferably resulting from homopolymerization of vinyl chloride in combination with a sorbitan fatty acid ester, as a dispersant, using an organic peroxide or azo compound as a catalyst, (B) 25-500pts.wt. of a polymeric plasticizer of more than 10,000mol.wt., wuch as polyester, ethylene-vinyl acetate copolymer, especially, an ethylene-vinyl acetate-carbon monoxide copolymer is preferred, when oil resistance and leaching-out resistance are required, and (C) 2-150pts.wt. of a graft polymer by grafting 0.5-30wt% of copolymerizable monomers such as vinyl acetate or butyl acrylate onto polyvinyl chloride with the major chain polymer of 200-2,000 polymerization degree.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vinyl chloride resin composition comprising polyvinyl chloride and a polymeric plasticizer and having good processability.

Vinyl chloride resin has excellent physical and mechanical properties, so it has many uses such as hard, semi-hard, and soft.

In order to obtain vinyl chloride resin molded products that are flexible and elastic at low to room temperatures, vinyl chloride resin is generally mixed with a plasticizer such as phthalate ester, trimellitate ester, or polyester. Above all, when trying to obtain a soft polyvinyl chloride composition with excellent oil resistance and extraction resistance, external plasticization using a polymer plasticizer with a molecular weight of 10,000 or more is recommended. It is preferable because it has superior oil resistance and extraction resistance compared to external plasticization using an agent.

By the way, when such a polymer plasticizer is blended with polyvinyl chloride obtained by a normal suspension polymerization method, there is a problem in that gelling properties during kneading are deteriorated.

This is because a film is formed on the particle surface by the dispersant used during polymerization, and it is presumed that this film acts as a barrier and prevents absorption of the plasticizer, resulting in deterioration of gelling properties during kneading. Ru. This tendency is remarkable in polymeric plasticizers with a molecular weight of 10,000 or more. Polyvinyl chloride with a small film, that is, vinyl chloride, is polymerized in the presence of (a) lipophilic sorbitan higher fatty acid ester and/or lipophilic polyoxyethylene sorbitan higher fatty acid ester in an aqueous medium. (b) When the polymerization conversion rate reaches 5 to 40%, the polyvinyl chloride produced by adding a water-soluble cellulose derivative is kneaded with a polymeric plasticizer having a molecular weight of 10.000 or more. It is known that the gelling properties can be improved by using Bamba I (Japanese Patent Laid-Open No. 58-168644).
It requires a strong kneading machine like a JE mixer.

However, when kneading with such a strong kneading machine, thermal deterioration becomes severe and the problem arises that the product becomes discolored.

In addition, this problem can be solved by using a mixing machine with weak kneading such as a two-roll machine or an extruder, but in reality, there is a problem that lumps remain due to insufficient kneading, and further improvement of the resin composition is required. desired.

The present inventors have conducted intensive research to obtain a vinyl chloride resin composition that has excellent gelling properties even in weak kneading machines such as two rolls and extruders.
It was discovered that the gelling properties were surprisingly improved by adding a graft copolymer obtained by graft copolymerizing a polymeric plasticizer of .

That is, the present invention comprises 100 parts by weight of polyvinyl chloride, 25 to 500 parts by weight of a polymer plasticizer, and 0.5 to 30 parts by weight of a monomer capable of graft copolymerization to 99.5 to 70 parts by weight of polyvinyl chloride. This is a vinyl chloride resin composition with good processability, characterized by comprising 2 to 150 parts by weight of a graft copolymer.

The polyvinyl chloride used in the present invention is a homopolymer of vinyl chloride, for example, sorbitan higher fatty acid ester, polyoxyethylene rubitan higher fatty acid ester, water-soluble cellulose derivative, polyvinyl alcohol, polyvinylpyrrolidone, gelatin, etc. are dispersed therein. Organic peroxides such as benzoyl peroxide, lauroyl peroxide, cabroyl peroxide, diisopropyl peroxydicarbonate, di(2-ethylhexyl) peroxycica 7bonate, and tert-butyl peroxybivalate can be used together as a catalyst. Oxide; 212
Azo compounds such as '-azobisisobutyronitrile, 2゜21-azobis-2,4-dimethylvaleronitrile, 2.21-azobis-4-methoxy-2,4-dimethylvaleronitrile, etc. alone or in combination Preferably, those obtained by polymerizing vinyl chloride are used.

Examples of polymer plasticizers used in the present invention include polyester polymer plasticizers, ethylene-vinyl acetate-based polymer plasticizers, and polymer plasticizers made of ethylene-vinyl acetate-carbon oxide copolymers. Mention may be made of molecular plasticizers and modified products thereof. Note that a molecular weight of in, ooo or more is desirable due to problems such as bleeding. Among them, a polymeric plasticizer made of a copolymer of ethylene/vinyl acetate/carbon oxide and having a molecular weight of 1o, 00 or more is particularly effective in obtaining a polyvinyl chloride composition having oil resistance and extraction resistance.

The blending amount of the polymer plasticizer is preferably 25 to 500 parts by weight per 100 parts by weight of polyvinyl chloride. If it is less than 25 parts by weight, there will be little plasticizing effect (and if it is used in excess of 500 parts by weight, the properties of polyvinyl chloride will be impaired, which is not preferable).

The vinyl chloride graft copolymer added in the present invention is a graft copolymer obtained by graft-copolymerizing polyvinyl chloride with a graft-copolymerizable monomer, and examples of the graft-copolymerizable monomer include ethylene,
Propylene, ■-butene, ■-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene,
Olefins having 2 to 30 carbon atoms such as 1-tetradecene,
These include styrene, acrylic acid or its esters, methacrylic acid or its esters, fumaric acid or its esters, maleic acid or its esters, vinyl compounds such as vinyl acetate, vinyl propionate, and alkyl vinyl ethers. They may be used alone or in combination of two or more.

Moreover, the amount of these monomers in the graft copolymer is 0.
5 to 30% by weight, and outside this range,
The effect of the present invention cannot be obtained.

In addition, polyvinyl chloride as the backbone polymer has a polymerization degree of 2.
00 to 2,000, preferably 400 to 1,500.

The blending amount of the vinyl chloride graft copolymer is preferably 2 to 150 parts by weight based on 100 parts by weight of polyvinyl chloride. Outside this range, the effects of the present invention cannot be obtained.

The composition of the present invention includes polyvinyl chloride, a vinyl chloride graft copolymer, and a polymeric plasticizer, as well as a stabilizer, a lubricant, a blowing agent, a filler, an ultraviolet absorber, a pigment, a leveling agent, and a conductive agent, as necessary. By adding additives such as carbon and flame retardants,
It is obtained by mixing in a known device such as a Henschel mixer or a ribbon blender.

In addition, as a mixing device, it is possible to use anything from a Bamba IJ-mixer, which has a strong kneading capacity, to a two-roll machine, an extruder, etc., which has a weak kneading capacity. It will be put to practical use.

When the composition of the present invention is molded, it has a smooth surface due to the small amount of ungelled particles, and is suitable for use in medical, industrial, and food applications.

The present invention will be explained below with reference to Examples.

Example 1 1,200 ml of pure water in an autoclave with an internal volume of 3,000 ml
kg, hydroxypropyl methylcellulose 1.2 to 9
, polyvinyl chloride I/600kg with a degree of polymerization of 800, α,
Add 9 to α1-azobisisobutyronitrile 3.0,
After replacing the internal air with nitrogen, vinyl acetate 70 to 9
was loaded. After reacting at 80°C for 10 hours, unreacted monomers were removed from the reaction product, which was dehydrated and dried.
A powdered graft copolymer resin was obtained.

As a result of analysis, this graft copolymer resin contained 10% of components other than vinyl chloride.

This graft copolymer resin was added to polyvinyl chloride with a polymerization degree of 1050 in the proportions shown in Table 1, a polymer plasticizer and Ca
- A roll sheet was prepared by blending with a Ba-based composite stabilizer, and the gel level was evaluated.

Examples-2 to -9 In place of the polyvinyl chloride with a polymerization degree of 800 in Example-1, polyvinyl chloride with a polymerization degree shown in Table 1 was used, and in place of vinyl acetate 70 with 9, the Graft copolymerization was carried out in the same manner as in Example 1 using the comonomers shown so that the amount of comonomer polymerized was as shown in Table 1 to obtain a graft copolymer resin.

Hereinafter, the gel level value was determined in the same manner as in Example-1.

Comparative Examples-1 to 12 Polyvinyl chloride with a degree of polymerization of 1050, vinyl chloride graft copolymer, polymer plasticizer, and C
A roll sheet was prepared by blending an a-Ba type composite stabilizer, and the gel level was evaluated.

Gel test is approximately 0.3m' with 8 inch roll at 160℃
Knead for 10 minutes at rn thickness and take out as a sheet1.
The unmelted polyvinyl chloride particles in a square (0 crn x 10 CrL) were counted visually. The unit is the number of pieces.

The results of these measurements are shown in Table 1.

Examples 10 to 12 and Comparative Examples 13 to 15 A copolymer, a polymer plasticizer, and a Ca-Ba composite stabilizer were blended, and the gel level was evaluated in the same manner as in Example-1. The results of these measurements are shown in Table 2.

Example-13 Polyvinyl chloride with a polymerization degree of 28 instead of polyvinyl chloride with a polymerization degree of 1050
The gel level was evaluated in the same manner as in Example-1 except that 00 polyvinyl chloride was used, and the result was 90.

Comparative Example-16 Polyvinyl chloride with a polymerization degree of 28 instead of polyvinyl chloride with a polymerization degree of 1050
Comparative Example-10 except that 00 polyvinyl chloride was used.
As a result of evaluating the gel level in the same manner as above, it was found to be 800 pieces.

Comparative examples of polyvinyl chloride, vinyl chloride graft copolymers alone, or vinyl chloride copolymers less than 1 part by weight or more than 150 parts by weight have a gel level of 100 or more, but in the examples of the present invention, none It was also excellent, with less than 100 pieces.

patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 1) 100 parts by weight of polyvinyl chloride, 25 to 25 parts of polymer plasticizer
500 parts by weight, and 99.5 to 70 parts by weight of polyvinyl chloride
Graft copolymers 1 to 15 obtained by graft copolymerizing 0.5 to 30% by weight of monomers capable of graft copolymerization to % by weight
0 parts by weight of a vinyl chloride resin composition with good processability.