JPS5836015B2 - resin composition - Google Patents

Description

[Detailed description of the invention] The present invention relates to a resin composite having excellent transparency.

More specifically, the soft vinyl chloride graft copolymer is produced by polymerizing a vinyl chloride heptanomer or a heptanomer mixture mainly composed of vinyl chloride monomers in the presence of an ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVA). This invention relates to a resin composition with excellent transparency consisting of a polymer and a phenol resin.

Conventionally, in the field of soft polyvinyl chloride (hereinafter abbreviated as PVC), volatilization or migration of plasticizers has been a problem, and blends of EVA and PVC or chlorination of EVA and EVA have been used for the purpose of making plasticizers soft and non-plastic. Vinyl grafting has been done.

It is well known that when the EVA content of an EVA vinyl chloride graft copolymer is gradually increased, the properties of the graft copolymer change from hard to semi-hard to soft. It is also known that the process makes it possible to obtain graft copolymers with a high EVA content.

However, although the EVA monochloride graft copolymer with a high EVA content has increased flexibility, some problems remain unsolved, and as a result, it is limited to soft PVC plasticized with phthalate esters. It has only reached the point where it can be replaced in the areas where it has been replaced.

Transparency in particular has been an unavoidable drawback until now, and soft EVA-vinyl monochloride graft copolymers have not been able to be used in applications requiring transparency.

The present invention aims to provide a simple and economical solution to the transparency problem that has been a drawback of flexible EVA vinyl monochloride graft copolymers.

To achieve this objective, in the present invention, 30 to 85 parts by weight of vinyl chloride monomer or a monomer mixture mainly composed of vinyl chloride monomer is added in the presence of 15 to 70 parts by weight of EVA having an ethylene content of 35 to 75% by weight. A soft vinyl chloride graft copolymer having excellent transparency is obtained by blending 0.5 to 50 parts by weight of a phenol resin with 100 parts by weight of a soft vinyl chloride graft copolymer obtained by polymerizing I was able to get it.

Conventionally, despite its importance, the transparency of soft vinyl chloride-based graft copolymers has only been slightly improved by graft polymerization, and improvements by the simple method of blending are unknown. Not yet.

The present inventors have discovered that while maintaining the performance of a soft vinyl chloride-based graft copolymer, the transparency can be easily improved by blending a phenol resin in a specific proportion, and have arrived at the present invention.

The present invention will be explained in detail below.

The soft EVA monochloride graft copolymer used in the present invention is prepared by polymerizing 30 to 85 parts by weight of a vinyl chloride monomer or a monomer mixture mainly composed of vinyl chloride monomers in the presence of 5 to 70 parts by weight of EVAI. It can be obtained by

Suspension polymerization is usually used as a method for graft polymerizing vinyl chloride monomers to EVA, but any method such as emulsion polymerization, bulk polymerization, or solution polymerization may be used.

The weight ratio of EVA and vinyl chloride monomer is 70/30
-15/85, and if it is greater than 70/30, it lacks the flexibility characteristic of soft vinyl chloride resins and becomes difficult to handle due to blocking, etc., and if it is less than 15/85, flexibility cannot be obtained.

EVA can be manufactured by any conventional process such as high pressure method or solution method.
~75% by weight is used.

EVA with an ethylene fraction of less than 35% by weight has poor low-temperature properties, so the resulting graft copolymer lacks low-temperature flexibility.
If the amount exceeds 75% by weight, EVA becomes hard and is not suitable for obtaining a soft vinyl chloride graft copolymer.

In addition, the melt index of EVA is 0.1 to 40.
A range of 0 g7'10Tnilt is used.

Monomers that can be copolymerized by mixing with vinyl chloride monomers include acrylic acid derivatives and methacrylic acid derivatives such as ethyl acrylate, methyl acrylate, octyl acrylate, and methyl methacrylate, olefins such as ethylene and propylene, fumaric acid, and maleic acid esters. Examples include vinyl esters such as vinyl ether, vinyl acetate, and vinyl propionate.

Phenol resins used in the present invention include phenol, resorcinol, cresol, xylenol,
A phenol-formaldehyde resin produced by the condensation or co-condensation reaction of phenols such as pt-butylphenol and p-phenylphenol with formaldehyde, with a specific gravity of 0.95 to 1.30 and a ring and ball softening point of 25 to 1.
It has a property of 80°C.

In general, there are non-thermally reactive types with extremely low methylol group content and thermally reactive types with many methylol groups, and both are effective in improving transparency.
In particular, non-thermal reaction type ones have the effect of improving melt fluidity and are also excellent in terms of processability.

In order to exhibit a sufficient effect in improving the transparency of the soft vinyl chloride graft copolymer, the amount of phenol resin should be 0.5 to 50 parts by weight per 100 parts by weight of the soft vinyl chloride graft copolymer. It is necessary.

If it is less than 0.5 parts by weight, the effect of improving transparency is small;
When the amount exceeds 0 parts by weight, flexibility decreases.

The soft vinyl chloride graft copolymer and the phenol resin are mixed and/or kneaded to form a uniform resin composition.

The mixing and cross-mixing methods include melt-kneading using a single-screw or twin-screw extruder, kneading using rolls, a Banbury mixer, and the like.

The kneading temperature may be within a range where the resin melts and does not cause decomposition, but the kneading is usually carried out at 100°C or higher and 200°C or lower.

The mixing time may be determined by selecting the time required to obtain a uniformly mixed resin composition.

The resin according to the present invention can be processed into films, sheet pipes, hoses, etc. by methods such as calendering, extrusion, injection molding, etc. in the same manner as conventional soft vinyl chloride graft copolymers.

According to the present invention, transparency, which has conventionally been difficult to improve, can be improved at low cost without substantially reducing other properties.

The soft vinyl chloride-based graft copolymer according to the present invention is particularly useful in fields where transparency and plasticizer non-migration are required, and has made a significant contribution to industry.

EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited in any way.

Examples 1 to 5 Comparative Example 1 Using a 3-inch roll, varying amounts of phenol resin were kneaded with a soft vinyl chloride graft copolymer at 130° C. for 1 minute.

The soft vinyl chloride graft copolymer has a vinyl acetate content of 40% by weight and a melt index of 75 g710.
A resin obtained by graft polymerizing 40 parts by weight of vinyl chloride monomer by suspension polymerization in the presence of 60 parts by weight of ethylene-vinyl acetate copolymer was used.

The phenol resin is CKM-2 manufactured by Showa Union Gosei.
400 (an oil-soluble nonthermally reactive phenolic resin with a ring and ball softening point of 145° C. and a specific gravity of 1.08) was used.

Resin 1 as a soft vinyl chloride graft copolymer stabilizer
1 part by weight of a dibutyltin laurate stabilizer and 1 part by weight of a dibutyltin maleate stabilizer were used per 00 parts by weight.

This resin composition was made into a 1-mm thick sheet and the light transmission rate and haze were measured.

The results are shown in Table 1. From Table 1, it can be seen that the soft vinyl chloride graft copolymer blended with a specific proportion of phenol resin is a resin with excellent transparency and little haze.

Furthermore, a resin composition in which 100 parts by weight of a phenolic resin was blended with 100 parts by weight of a soft vinyl chloride-based graft copolymer had decreased flexibility.

Examples 6 to 8 Comparative Example 2 As a soft vinyl chloride graft copolymer, the vinyl acetate content was over 32% by weight, and the melt index was 30. 9
The same procedure as in Examples 1 to 5 was carried out using a resin obtained by graft polymerizing 55 parts by weight of vinyl chloride heptanomer by a suspension polymerization method in the presence of 45 parts by weight of ethylene-vinyl acetate copolymer for 10 minutes. The light transmittance and haze of the resin composition obtained by kneading by the method were measured.

The results are shown in Table 2. Example 9 A soft vinyl chloride graft copolymer with a vinyl acetate content of 40% by weight and a tart index of 75,9/
Using a resin obtained by graft polymerizing 50 parts by weight of vinyl chloride monomer by suspension polymerization in the presence of 50 parts by weight of ethylene-vinyl acetate copolymer for 10 minutes, CKM2 10 manufactured by Showa Union Gokai was used as a phenol resin.
3 (i) An oil-soluble non-thermally reactive phenolic resin with a sphere softening point of 110° C1 and a specific gravity of 1.07 was kneaded in the same manner as in Examples 1 to 5, and the light transmittance and haze of the resulting resin composition were determined. was measured.

The results are shown in Table 3.

Claims (1)

[Claims] 1 In the presence of 15 to 70 parts by weight of an ethylene-vinyl acetate copolymer having an ethylene content of 35 to 75% by weight {polymerization of 30 to 85 parts by weight of vinyl chloride heptanomer or a monomer mixture mainly composed of vinyl chloride heptanomer Soft vinyl chloride graft copolymer 100 obtained by
A resin assembly with excellent transparency consisting of 0.5 to 50 parts by weight of phenolic resin and 0.5 to 50 parts by weight of phenolic resin.