JPH03182537A - Transparent flexible resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition excellent in transparency and flexibility and having good moldability by mixing a vinyl chloride resin with an ethylene/ vinyl acetate/carbon monoxide copolymer and a small amount of a hindered amine compound. CONSTITUTION:A transparent flexible resin composition is obtained by mixing 100 pts.wt. vinyl chloride resin with 30-160 pts.wt. ethylene/vinyl acetate/carbon monoxide copolymer and 0.02-0.5 pt.wt. hindered amine of the formula. This composition has good moldability as well as excellent transparency and flexibility. Unlike the conventional flexible vinyl chloride resin composition, it need not be mixed with a large amount of a plasticizer such as dioctyl phthalate, so that it is free from exudation or migration of the plasticizer to the surface of the composition. Therefore it can be desirably used in a field requiring especially transparency and flexibility, for example, as packaging material for synthetic resin articles or electronic equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a transparent soft resin composition with good moldability.

(Prior art) Vinyl chloride resin compositions made by blending vinyl chloride resins such as polyvinyl chloride with liquid plasticizers such as dioctyl phthalate have good moldability and excellent transparency and flexibility, and are particularly suitable for synthetic resin products. It is used as a packaging material for electronic devices and other products.

However, the liquid plasticizer contained in such transparent soft vinyl chloride resin compositions oozes out onto the surface and transfers to products such as synthetic resin products and electronic devices that come into contact with it, causing damage to the products. It has the disadvantage of reducing quality.

In order to improve these drawbacks, a resin composition has been proposed in which an ethylene-vinyl acetate-carbon monoxide copolymer is blended with a vinyl chloride resin. Since this resin composition does not contain a liquid plasticizer, it does not ooze or migrate to the surface of the resin & 11 precepts, and has excellent transparency and flexibility (see, for example, Japanese Patent Application Laid-Open No. 48-26228).

(Problem to be solved by the invention) However, ethylene-vinyl acetate-
When a carbon monoxide copolymer is blended and then melt-kneaded and extruded using a molding machine such as an extruder to make a molded rod of the composition, such as a tube, film, or sheet, the molten resin is molded. It tends to stick to metal parts (for example, molds, etc.) inside the processing machine, and this sticky material becomes colored or decomposes due to heat, which is a problem of deterioration of moldability.

Note that a lubricant is generally added to improve molding processability, but in this case, a large amount of lubricant (for example, 4 parts by weight or more) is added.
A good effect cannot be obtained unless it is mixed with. However, when such a large amount of lubricant is blended, the transparency of the obtained molded rod deteriorates.

The present invention is intended to solve the above-mentioned problems, and its purpose is to prevent the composition from oozing or migrating to the surface, prevent coloring or decomposition of the molten resin, and have good moldability. Moreover, it is an object of the present invention to provide a transparent soft resin composition having excellent transparency and flexibility.

(Means for Solving the Problems) That is, the transparent soft resin composition of the present invention includes 100 parts by weight of a vinyl chloride resin and 30 to 160 parts by weight of an ethylene-vinyl acetate-carbon monoxide copolymer. 0.02 to 0.5 parts by weight of the hindered amine compound, thereby achieving the above object.

The vinyl chloride resin used in the present invention refers to a homopolymer of vinyl chloride or a copolymer of vinyl chloride as a main component and one or more other monomers. , can be obtained by suspension polymerization, emulsion polymerization, etc. according to conventional methods.

Other polymers to be copolymerized with vinyl chloride include α-olefins such as ethylene and propylene, vinyl esters such as vinyl acetate, unsaturated carboxylic acid esters such as (meth)acrylic acid esters, and alkyl vinyl ethers. Examples include vinyl ethers, vinyl halides such as vinyl bromide and vinyl fluoride, and other vinyl monomers or vinylidene monomers other than those mentioned above, such as styrene, acrylonitrile, and vinylidene chloride.

In the present invention, polyvinyl chloride with an average degree of polymerization of 800 to 1,700 or a vinyl chloride-ethylene copolymer with an ethylene content of 2 to 8% by weight and an average degree of polymerization of 800 to 2,000 is particularly preferred. It may be mixed with the vinyl chloride-ethylene copolymer in any proportion.

Further, the ethylene-vinyl acetate-carbon monoxide copolymer used in the present invention can be used, for example, in the above-mentioned JP-A-48-26222
As described in the publication, ethylene, vinyl acetate, and carbon monoxide are fed in a predetermined ratio into an autoclave equipped with a stirrer together with t-butylperoxyisobutyrate or azodiisobutyronitrile as a catalyst. Mix and heat at high temperature (e.g. 160-230°C) and high pressure (e.g. 24°C).
,000 to 27,000 psi) under high speed stirring and copolymerization.

Further, such an ethylene-vinyl acetate-carbon monoxide copolymer is commercially available, such as Elvaloy 741 manufactured by DuPont.

In the above ethylene-vinyl acetate-carbon monoxide copolymer, the content of the ethylene component is 40 to 80% by weight, preferably 50 to 70% by weight, and the content of the vinyl acetate component is 1% by weight.
0 to 60% by weight, preferably 10 to 40% by weight, and the content of carbon oxide component is 5 to 30% by weight, preferably 5 to 20% by weight.
It is desirable to have a range of % by weight, and if necessary (
It is also possible to copolymerize other monomers such as meth)acrylic esters.

Such ethylene-vinyl acetate-carbon monoxide copolymer is
It is desirable that the melt flow rate is 1 to 500 g/10 min, preferably 10 to 50 g/10 min. The melt flow rate is in accordance with ASTM D 123B or JI
According to S7210, temperature 190°C 1 load 2.1
This value was measured under the condition of 6.

The ethylene-vinyl acetate-carbon monoxide copolymer is blended in an amount of 30 to 160 parts by weight per 100 parts by weight of the vinyl chloride resin.

If the amount is less than 30 parts by weight, the composition will have poor transparency and flexibility. On the other hand, if the blending amount exceeds 160 parts by weight, the composition tends to become sticky.

Generally, the vinyl chloride resin and ethylene vinyl acetate
The carbon monoxide copolymer is a mixture of the two, but those obtained as follows can also be used.

(1) So-called graft polymers obtained by radical polymerization of vinyl chloride alone or vinyl chloride and other monomers that can be copolymerized with vinyl chloride in the presence of an ethylene-vinyl acetate-carbon monoxide copolymer. The graft polymer also contains a mixture of ethylene-vinyl acetate-carbon monoxide copolymer and vinyl chloride homopolymer or vinyl chloride copolymer).

(2) A mixture of the above graft polymer and an ethylene-vinyl acetate-carbon monoxide copolymer.

(3) A mixture of the above graft polymer and a vinyl chloride resin.

Further, the hindered amine compound represented by the above structural formula used in the present invention is, for example, 5anol from Ciba Geigy.
It is commercially available as LS-770.

Such a hindered amine compound is blended in an amount of 0.02 to 0.5 parts by weight based on 100 parts by weight of the vinyl chloride resin. If the blending amount is less than 0.02 part by weight, the prevention of adhesion to the metal parts in the molding machine will not be achieved well, and the effect of improving moldability will be small.

On the other hand, if the blending amount exceeds 0.5 parts by weight, coloring tends to occur as a whole.

The composition of the transparent soft resin composition of the present invention is as described above, but in order to mold a molded article from the compounded composition, it is necessary to add thermal stability and lubricants, plasticizers, antistatic agents, colorants, and fillers. Compounding agents commonly used in vinyl chloride resins such as
A small amount may be added as necessary within a range that does not impair the purpose of the present invention.

The blended composition thus blended is supplied to a molding machine such as an extruder, either as a blended powder or once melt-kneaded and in the form of pellets, and molded into a mold, for example, into a tube.
It is molded into molded objects such as films or sheets.

(Function) When an appropriate amount of ethylene-vinyl acetate-carbon monoxide copolymer is blended with vinyl chloride resin as in the present invention, a composition with excellent transparency and flexibility and no oozing can be obtained. . Furthermore, when an appropriate amount of the specific hindered amine compound described above is blended, it becomes difficult to stick to metal parts (for example, a mold) in a molding machine, and coloration and decomposition due to heat are prevented. Additionally, this particular hindered amine compound is
No oozing to the surface of the composition.

(Example) Examples and comparative examples of the present invention are shown below.

Lost employee 1 Vinyl chloride-ethylene copolymer (average degree of polymerization 1300,
100 parts by weight of ethylene component (4 type weight%), 70 parts by weight of ethylene-vinyl acetate-carbon monoxide copolymer (Elvaloy 741: manufactured by DuPont), and a hindered amine compound (
Sanol LS-770: Ciba Geigy) 0.0
5 parts by weight, 1.0 parts by weight of Ca-Zn stabilizer (Mark 37: manufactured by Adeka Argus), and epoxidized soybean oil (0
-130P: manufactured by Adeka Argus) 10 parts by weight and 0.5 parts of lubricant (Hiwax 4202E: manufactured by Mitsui Petrochemicals)
parts by weight were kneaded for 5 minutes with a roll heated to 180°C to form a sheet, which was then cut to obtain pellets.

The pellets were supplied to a 65mΦ single screw extruder equipped with a T-die with a width of 650IIIm, and cylinder 1:
120°C, cylinder 2: 140°C, cylinder 3 = 150°C, T die: 160°C, extrusion amount: 40kg/
A sheet having a thickness of 0.4 mm was continuously extruded for 20 hours under the condition of 100% fir, and its moldability, transparency, haze, and exudation properties were evaluated.

(1) Molding Processability Immediately after 20 hours of continuous extrusion molding, the molten resin in the T-die was sampled and observed for its color tone and the state of resin adhesion within the T-die. As a result, the inside of the T-die was uniform with no resin adhesion or coloring.

(2) Transparency For sheets with a thickness of 0.4 m, JIS K 710
The light transmittance was measured according to 5. As a result, the light transmittance was 90.2%.

(3) Haze (haze value) The haze of a 0.4-thick sheet was measured in accordance with JIS-7105. As a result, the haze is 4.0
%Met.

(4) Leakability A sheet with a thickness of 0.4 tm was left in a hot air constant temperature bath at 40° C. for a month, and the degree of staining on the sheet surface was observed. As a result, no stains were observed on the sheet surface.

Hindered amine compound (Sanol LS-770,
The same procedure as in Example 1 was conducted except that the amount of Ciba Geigy (manufactured by Ciba Geigy) was changed to 0.02 parts by weight.

As a result, the inside of the T-die was uniform with no resin adhesion or coloring. In addition, the light transmittance is 90.2%, and the height is 3.8%.
%, no stains were observed on the sheet surface.

Sanol tetrapod hindered amine compound (Sanol LS-770,
The same procedure as in Example 1 was carried out except that the amount of Ciba Geigy (manufactured by Ciba Geigy) was changed to 0.1 part by weight.

As a result, there was no adhesion of resin inside the T-die, and although the resin was colored slightly yellow, the color was uniform as a whole. Furthermore, the light transmittance was 89.8%, the haze was 4.5%, and no stains were observed on the sheet surface.

Hindered amine compound (Sanol LS-770,
Except that it did not contain any Ciba Geigy (manufactured by Ciba Geigy)
The same procedure as in Example 1 was carried out.

As a result, there was a part of the resin that was strongly discolored to brown, and this part remained attached to the mold.

In addition, there was a brown gel-like substance in a part of the sheet.

Further, the light transmittance was 90.0%, the haze was 3.8%, and no stains were observed on the sheet surface.

Comparison Hindered amine compound (Sanol LS-770,
The same procedure as in Example 1 was carried out, except that the amount of the compound (manufactured by Ciba Geigy) was changed to 1.0 parts by weight.

As a result, although there was no resin attached inside the T-die, the resin as a whole was strongly colored yellow.

Furthermore, the light transmittance was 90.0%, the haze was 7.0%, and no stains were observed on the sheet surface.

Kitakashi lubricant (Hiwax 4202E: manufactured by Mitsui Petrochemicals)
The same procedure as in Example 1 was carried out except that the blending amount was changed to 4.0 parts by weight.

As a result, the inside of the T-die was uniform with no resin adhesion or coloring. Also, the light transmittance is 80.2% and the haze is 16.
3%, no stains on the sheet surface were observed.

(Effects of the Invention) As described above, the transparent soft resin composition of the present invention contains 100 parts by weight of a vinyl chloride resin and 30 to 160 parts by weight of an ethylene-vinyl acetate-carbon monoxide copolymer. 11! Consisting of part E and 0.02 to 0.5 parts by weight of the specific hindered amine compound described above, such an m-acid not only has excellent transparency and flexibility, but also has good moldability.

Further, unlike conventional soft vinyl chloride resin compositions, it is not necessary to contain a large amount of plasticizer such as dioctyl phthalate, so that the composition does not ooze or migrate to the surface.

Therefore, the transparent soft resin composition of the present invention can be suitably used in applications that particularly require transparency and flexibility, such as packaging materials for synthetic resin products and electronic devices.

Claims (1)

[Claims] 1. 100 parts by weight of vinyl chloride resin, 30 to 160 parts by weight of ethylene-vinyl acetate-carbon monoxide copolymer, and the structural formula ▲ Numerical formula, chemical formula, table, etc. ▼ A transparent flexible vinyl chloride resin composition comprising 0.02 to 0.5 parts by weight of a hindered amine compound.