JPH05311022A - Polyvinyl chloride composition - Google Patents

Abstract

PURPOSE:To provide a polyvinyl chloride compsn. contg. a high-molecular plasticizer, excellent in antistatic properties, bleeding little to the surface, and nonsticky. CONSTITUTION:A polyvinyl chloride compsn. comprises polyvinyl chloride, an ethylene-unsatd. ester-carbon monoxide copolymer, a polyethylene glycol having a number-average mol.wt. of 200-2,000, and an inorg. salt selected from the group consisting of an alkali metal perchlorate and an alkali metal thiocyanate. The compsn. may further be compounded with a liq. plasticizer and/or a thermoplastic elastomer prepd. by polycondensation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antistatic formulation of polyvinyl chloride containing a polymer plasticizer.

[0002]

2. Description of the Related Art Polyvinyl chloride (PVC) is used in various fields because of its low cost and excellent characteristics. Soft grades containing a liquid plasticizer such as DOP and DINP are particularly widely used, but the problem is that the plasticizer volatilizes and is lost over time, and the surface of the molded product is soiled or the physical properties change. Therefore, a part or all of the liquid plasticizer is replaced with a polymer plasticizer composed of an ethylene / unsaturated ester / carbon monoxide copolymer. However, PVC containing such a polymer plasticizer is problematic in that it may cause electrostatic damage depending on the application because the volume resistivity value is not sufficiently small, and an antistatic formulation for this compounded composition is required. It was Many prescriptions have been proposed for enhancing the antistatic performance of PVC, but it is applied to a polymer plasticizer compounding system, is inexpensive, has no trouble of stickiness due to bleeding, and does not adversely affect physical properties. The prescription was unknown.

[0003]

Therefore, the present inventors have found that
Considering that in practical use, if the volume resistivity value is 10 ¹⁰ Ω · cm or less, the fields of application can be expected to expand, and a cheap and effective antistatic prescription of polymer plasticizer-containing PVC is studied. It was As a result, they have reached the present invention by finding that a synergistic effect can be expected when the two types of additives described below are used in combination, and that the volume resistivity can be effectively reduced by adding a small amount. Therefore, it is an object of the present invention to provide an antistatic formulation for PVC containing a polymer plasticizer, which is inexpensive and does not substantially adversely affect the physical properties, without troubles due to excessive bleeding.

[0004]

That is, according to the present invention, polyvinyl chloride (A), ethylene / unsaturated ester /
Carbon monoxide copolymer (B), number average molecular weight 200 to 200
A resin composition comprising 0. polyethylene glycol (C) and an inorganic salt (D) selected from the group consisting of alkali metal perchlorates and alkali metal thiocyanates is provided.

Polyvinyl chloride (A) used in the present invention
Is a vinyl chloride homopolymer or copolymer produced by various polymerization methods such as suspension polymerization, emulsion polymerization or bulk polymerization, or a mixture thereof. As the copolymer, ethylene, α-olefin such as propylene, vinyl ester such as vinyl acetate, acrylic ester,
Examples of random copolymers with unsaturated carboxylic acid esters such as methacrylic acid esters, vinyl ethers such as alkyl vinyl ethers, vinyl bromide, vinyl halides such as vinyl fluoride, acrylonitrile, styrene, vinylidene chloride, etc. be able to. These other monomers may be copolymerized in an amount of, for example, 20 mol% or less. As another example of the copolymer, a graft copolymer obtained by using ethylene / vinyl acetate copolymer, thermoplastic polyurethane or the like as a trunk polymer, and vinyl chloride or vinyl chloride and another monomer are graft-polymerized thereto May be

Ethylene / unsaturated ester / carbon monoxide copolymer used as a polymer plasticizer in the present invention
(B) can be generally obtained by high-pressure radical copolymerization of ethylene / unsaturated ester and carbon monoxide. Examples of the unsaturated ester include vinyl esters such as vinyl acetate, methyl acrylate, ethyl acrylate, isobutyl acrylate, and n-acrylate.
Representative examples thereof include unsaturated carboxylic acid esters such as butyl, 2-ethylhexyl acrylate, isooctyl acrylate, and methyl methacrylate. The polymerization composition of the copolymer is usually 40 to 90% by weight of ethylene, preferably 50 to 80% by weight, and 5 of unsaturated ester.
It is generally in the range of -50 wt%, preferably 10-30 wt%, and carbon monoxide in the range of 3-30 wt%, preferably 5-20 wt%. Further, the melt flow rate of the copolymer (190 ° C., 2160 g load) is 1 to 500 g / 1.
It is preferable to use one for 0 minutes, particularly 5 to 100 g / 10 minutes. The copolymer may be partially crosslinked with a peroxide, an electron beam or a polyfunctional reaction reagent. Such partial cross-linking can be performed before or after compounding.

The polyethylene glycol (C) used in the present invention has a number average molecular weight of 200 to 2000, preferably 250 to 1000. When the number average molecular weight is larger than the above range, no remarkable antistatic improvement effect is observed.

In the present invention, an inorganic salt (D) selected from an alkali metal salt of perchloric acid and an alkali metal salt of thiocyanate is used together with the above polyethylene glycol. As the alkali metal salt, salts of lithium, sodium, potassium and the like are preferable. By adding these inorganic salts, it is possible to synergistically enhance the antistatic property of polyvinyl chloride containing a polymer plasticizer.

In addition to the above-mentioned essential components, the resin composition of the present invention may contain additives such as various stabilizers, liquid plasticizers, solvents, pigments and carbon black. Further, in order to improve various physical properties such as mechanical strength and heat resistance, other thermoplastic polymer may be blended. As such additives or compounding agents, dioctyl phthalate, dinonyl phthalate, liquid plasticizers such as tricresyl phosphate, zinc stearate, calcium stearate, barium stearate, stabilizers such as epoxidized soybean oil, Examples thereof include rubber reinforced resins such as ABS, MBS and AES, condensation polymerization type thermoplastic elastomers such as polyester ether elastomer, polyester ester elastomer and polyether amide elastomer.

The blending amount of the ethylene / unsaturated ester / carbon monoxide copolymer varies depending on the purpose of use, but is usually 20 to 200 parts by weight, preferably 50 to 150 parts by weight per 100 parts by weight of polyvinyl chloride. It is generally used in proportion. When a liquid plasticizer or another thermoplastic resin is blended, the blending amount can be arbitrarily selected, and for example, each can be used in a proportion of 200 parts by weight or less with respect to 100 parts by weight of polyvinyl chloride. ..

If the amount of polyethylene glycol is too small, the effect is small. On the other hand, if the amount is too large, the amount of bleeding on the surface is large and it causes stickiness. The allowable blending amount varies depending on the type and blending ratio of each component of the resin composition and cannot be specified unconditionally, but is usually 0.1 to 10% by weight, particularly 0.5 to 5% by weight in the composition. It is good to mix in a ratio.

The preferable range of the amount of the alkali metal perchlorate and the alkali metal thiocyanate to be blended in the composition is
The amount is preferably 0.05 to 5% by weight, particularly 0.1 to 2% by weight.

[0013]

The present invention will be specifically described with reference to the following examples. In each of the examples and comparative examples, polyvinyl chloride, ethylene copolymer, polyethylene glycol, alkali metal salts and various stabilizers, plasticizers, thermoplastic elastomers, etc. shown in Table 1 were used.

The antistatic performance of the test pieces prepared in each example was evaluated by measuring the volume resistivity and surface resistivity by the following method. (1) Volume resistivity The prepared test piece was placed under conditions of temperature and humidity of 23 ° C. and 55% RH for 24 hours, and under the same conditions, Yokogawa Hewlett-Packard Co., Ltd. High Resistance Meter 4329
It measured using the A type. (2) Surface resistivity After placing the prepared test piece for 24 hours in the temperature and humidity conditions of 23 ° C. and 35% RH, under the same conditions, a high resistivity meter Hiresta IP manufactured by Mitsubishi Petrochemical Co., Ltd. It was measured using.

Examples 1 to 7 Polyvinyl chloride and ethylene / acrylic acid n listed in Table 1
-Butyl / carbon monoxide copolymer, Ba / Zn heat stabilizer, epoxidized soybean oil, plasticizer, polyethylene glycol, lithium perchlorate, etc. were mixed in the mixing ratios shown in Table 2, and then small-sized. Using a mixer (Labo Plastomill manufactured by Toyo Seiki), the mixture was melt-kneaded at 170 ° C. for 10 minutes.
The obtained composition of the present invention was pressure-molded at 180 ° C. to form a sheet having a thickness of 2 mm, and its electrical characteristics were evaluated by the above method. The results are shown in Table 2.

Comparative Examples 1 to 7 As shown in Table 2, compositions containing no essential components of the present invention were prepared by using the raw materials shown in Table 1 in the same manner as in Examples. A sheet was prepared and electrical characteristics were evaluated by the same method. The results are shown in Table 3. As is clear from the results of Tables 2 and 3, by incorporating all the essential components specified in the present invention, a synergistic effect is exhibited and the volume resistivity is 10 ¹⁰ Ω. It is possible to achieve electric characteristics at a level of cm ² or less.

[0017]

[Table 1] Raw materials used in Examples and Comparative Examples

[0018]

[Table 2] Composition and electrical characteristics

[0019]

[Table 3] Composition and electrical characteristics

[0020]

EFFECT OF THE INVENTION The resin composition of the present invention has substantially no change in physical properties over time and no stickiness, and has good antistatic property. Therefore, the resin composition has no antistatic property as a film, sheet or various molded articles. Required fields such as office automation equipment, automotive interior materials, flexible containers, clean gloves such as static gloves, static shoes and static aprons, general industrial and office machine rolls, card cases, hoses, and flooring materials. Can be widely used for.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08L 71/02 LQD 9167-4J LQE 9167-4J 73/00 LQQ 9167-4J 101/00 LSY 7242- 4J // (C08L 27/06 73:00 9167-4J 101: 00 7242-4J 71:02) 9167-4J

Claims (3)

[Claims] 1. A polyvinyl chloride (A), an ethylene / unsaturated ester / carbon monoxide copolymer (B), and a number average molecular weight of 20.
A resin composition comprising 0 to 2000 polyethylene glycol (C) and an inorganic salt (D) selected from the group consisting of alkali metal perchlorates and alkali metal thiocyanates. 2. The resin composition according to claim 1, further comprising a liquid plasticizer. 3. The resin composition according to claim 1, further comprising a condensation polymerization type thermoplastic elastomer.