JP3329016B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition, and more particularly to a thermoplastic resin composition having an antistatic property for a long period of time without impairing the mechanical properties of the resin. .

[0002]

BACKGROUND OF THE INVENTION Synthetic resins are characterized by their excellent properties in films, sheets, containers,
Although it is used in large quantities in a wide range of fields including industrial and daily necessities as molded parts and the like, it is generally known that various obstacles occur due to high electric insulation and easy electrification.

[0003] For example, in a polyethylene bag, the opening property is reduced due to electrification, and the filling work and the removal efficiency of contents are reduced. In a polystyrene television housing, dirt due to adhesion of floating dust to the surface due to electrification is severe. In a floppy disk case made of acrylonitrile-butadiene-styrene copolymer resin (ABS resin), data in a storage floppy disk may be destroyed by electrification, or an IC made of polyphenylene ether resin may be used.
The component container has a problem in that the IC circuit is destroyed due to charging, and various obstacles occur in various fields.

[0004] As means for preventing such obstacles,
For example, a conductive material such as a metal or carbon has been kneaded, or an anion, a cation, or a nonionic surfactant has been kneaded or applied to the surface. However, the kneading of the conductive material has problems that coloring can not be performed freely, resin properties are easily reduced, and costs are increased.

[0005] In addition, surfactants are effective in the short term but have poor solubility in resins, so they migrate to the surface at an early stage because of their poor solubility in resins, and their effectiveness tends to be reduced when they are wiped with a cloth or paper or washed with water. Was. If a large amount of surfactant is added, the duration will be prolonged, but the physical value of the resin will be greatly affected, and the surfactant will bleed to the surface of the resin and the surface will become sticky, resulting in a disadvantage that the commercial value will be reduced. Was.

In order to solve these problems, recently, a resin having a relatively low molecular weight and a large antistatic property has been blended to form a polymer alloy, which is immobilized in a matrix resin to exhibit semi-permanent antistatic properties. The technology that is trying to make it evolve. For example, JP-A-60-23435
JP, JP-A-61-73753, JP-A-2-1
This is a method of using a polyetheresteramide resin which is a hydrophilic resin as disclosed in JP-A-94052 and JP-A-3-26756, or blending polyethylene oxide as disclosed in JP-A-2-233743 and the like.

[0007] These techniques are excellent in permanent antistatic properties and are an innovation of the prior art. However, since a specific resin is blended, there is a limit in terms of compatibility depending on the type of the base resin, and the compatibility is low. It is necessary to use a solubilizer in combination, or a considerably large amount of addition is required to exert the effect, and it is not satisfactory in terms of cost.

[0008]

In view of this situation, the present inventors have conducted intensive studies on the problems of the prior art, and as a result, have found a new technique and completed the present invention.

That is, the present invention provides: a) 100 parts by weight of a thermoplastic resin (excluding b) below; b) 1 to 20 parts by weight of an alkylene oxide adduct of a saponified ethylene-saturated vinyl carboxylate copolymer Part, and c)
The present invention provides a thermoplastic resin composition containing 0.1 to 5 parts by weight of an alkali metal salt of a halogen-containing acid.

Hereinafter, the present invention will be described in detail. The thermoplastic resin used in the present invention is a high-density polyethylene, a low-density polyethylene, polypropylene, polyvinyl chloride, polystyrene or a copolymer with these basic monomers, for example, an ethylene-butene copolymer, which is positioned as a general-purpose plastics. , Ethylene-hexene copolymer, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-acrylic acid copolymer, ethylene-vinyl alcohol copolymer, acrylic acid Methyl polymer, methyl methacrylate polymer, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene copolymer, and polyamides, polyacetals, polycarbonates, which are positioned as general-purpose engineering plastics Polyphenylene ether, polybutylene terephthalate, etc., polyethylene terephthalate, polysulfone, which is positioned as the super engineering plastic, polyether sulfone,
Representative examples include polyphenylene sulfide, polyarylate, polyamide imide, polyether imide, polyether ketone, polyether ether ketone, and polyimide.Chemically modified products of these thermoplastic resins, mixtures, alloys, glass fibers, and the like May be enhanced. The thermoplastic resin used in the present invention does not include b) an alkylene oxide adduct of a saponified ethylene-saturated carboxylic acid vinyl ester copolymer.

The thermoplastic resins used in the present invention are the above-listed resins and the like. However, the thermoplastic resins have many uses as molding materials and are particularly suitable for resins having a long product life. Resins containing a polymer, for example, polystyrene (including impact-resistant polystyrene), acrylonitrile-butadiene-styrene copolymer, and the like are more preferably used.

The alkylene oxide adduct of the saponified ethylene-saturated carboxylic acid vinyl ester copolymer used in the present invention is obtained by saponifying the ethylene-saturated carboxylic acid vinyl ester copolymer to obtain a part or all of the saturated carboxylic acid vinyl ester. Is converted to a vinyl alcohol structure, and is produced by grafting an alkylene oxide. It is presumed that the main chain has a polyethylene unit and the side chain has a polyoxyalkylene unit.

The production method is not particularly limited. For example, a method described in JP-A-3-227307, that is, by heating an ethylene-saturated vinyl carboxylate copolymer and an alcohol in the presence of an alkali catalyst. After saponification and removal of alcohol, alkylene oxide is introduced,
A grafting method may be used.

As the ethylene-saturated carboxylic acid vinyl ester copolymer used in the present invention, an ethylene-vinyl acetate copolymer is particularly preferred in view of availability from an industrial standpoint, price, and the like. Those having a number average molecular weight of 5 to 50% by weight and a number average molecular weight of 1000 to 5000 are preferable because the bulk saponification reaction is easy. Among them, particularly preferred are those having a vinyl acetate unit content of 15 to 40% by weight and a number average molecular weight of 1500 to 3000.

The saponification rate of the ethylene-vinyl acetate copolymer is preferably in the range of 30 to 100% in order to obtain a resin having good compatibility with the resin, and ethylene oxide to the saponified ethylene-vinyl acetate copolymer is preferably used. The addition amount is preferably 50 to 1000 parts by weight with respect to 100 parts by weight of the saponified ethylene-vinyl acetate copolymer in view of the compatibility with the resin and the antistatic effect, and 100 to 500 parts by weight.
A range of parts by weight is more preferred.

The alkali metal salt of a halogen-containing acid used in the present invention is, for example, a halogen acid anion such as iodic acid, chloric acid or bromic acid, or a peroxide such as periodic acid, perchloric acid or perbromic acid as an anion. Halogenate anion, trichloromethanesulfonic acid, trifluoromethanesulfonic acid,
Trichloroacetic acid, an organic acid anion having an alkyl halide such as trifluoroacetic acid and the like, lithium, sodium, potassium, rubidium as a cation,
It is a salt composed of a combination with an alkali metal such as cesium.

In the practice of the present invention, among these alkali metal salts of halogen-containing acids, lithium perchlorate or lithium trifluoromethanesulfonate is particularly preferred because of its excellent compatibility and high antistatic properties. preferable.

In carrying out the present invention, the thermoplastic resin 1
With respect to 00 parts by weight, the alkylene oxide adduct of the saponified ethylene-saturated carboxylic acid vinyl ester copolymer is 1 to 20 parts by weight, preferably 1.5 to 10 parts by weight,
The alkali metal salt of a halogen-containing acid is compounded in an amount of 0.1 to 5 parts by weight, preferably 0.15 to 2 parts by weight.

If the amount of the alkylene oxide adduct of the saponified ethylene-saturated carboxylic acid vinyl ester copolymer is less than 1 part by weight, the effect obtained by the addition is hardly expected. It is not preferable because the mechanical properties of the resin are reduced.

If the amount of the alkali metal salt of a halogen-containing acid is less than 0.1 part by weight, the effect obtained by the addition is hardly expected. If the amount is more than 5 parts by weight, the migration to the surface is difficult. This is undesirable because the appearance is reduced and the commercial value is reduced.

The thermoplastic resin composition of the present invention may be somewhat different depending on the type and shape of the target thermoplastic resin, but is obtained by mixing in the same manner as in a normal thermoplastic resin.

For example, a thermoplastic resin, an alkylene oxide adduct of a saponified ethylene-saturated carboxylic acid vinyl ester copolymer, or an alkali metal salt of a halogen-containing acid, together or sequentially, or separately, is divided into a Banbury mixer and a Henschel mixer. It is appropriate to use an open roll, a kneader, a single-screw or multi-screw extruder or the like to mix the mixture at a melting temperature or higher, but the equipment and method are not particularly limited.

The thermoplastic resin composition of the present invention can be used as a heat stabilizer, an antioxidant, a light stabilizer, a lubricant, an antifogging agent, a pigment, a foaming agent, a fluorescent agent, and a heat stabilizer, which are generally added to a thermoplastic resin. Fuel,
A release agent, a processing aid, a reinforcing agent, and the like may be contained as necessary.

[0024]

As described above, the thermoplastic resin composition of the present invention has a low surface specific resistivity, a small decrease in performance due to washing with water or wiping a cloth, and is excellent in antistatic properties. Further, the thermoplastic resin composition of the present invention can be used for a wide range of uses as sheets, films, molded products, and the like.

[0025]

EXAMPLES The present invention will be specifically described below with reference to examples, comparative examples and reference examples, but the present invention is not limited to these examples.

REFERENCE EXAMPLE 1 Production of alkylene oxide adduct of saponified ethylene-saturated carboxylic acid vinyl ester copolymer 120 kg of ethylene-vinyl acetate copolymer having a vinyl acetate content of 31% by weight and a number average molecular weight of 1900 was added to 250 kl.
In methanol, the reaction was carried out at 65 ° C. for 2 hours using 1.0 kg of potassium hydroxide as a catalyst. Subsequently, the temperature of the reaction solution was raised to 150 ° C. to distill off methanol to obtain 100 kg of a saponified product having a 90% saponification rate. Subsequently, 100 kg of the saponified product was heated to 180 ° C., and 200 kg of ethylene oxide was introduced over 2 hours to obtain 300 kg of a compound (hereinafter, referred to as an adduct).

Example 1 9 parts by weight of the adduct prepared in Reference Example 1 and 1 part by weight of lithium perchlorate were melt-mixed at 100 ° C. Next, high-impact polystyrene (Sumibrite M583 manufactured by Sumitomo Chemical Co., Ltd.) was supplied from a hopper by a twin-screw extruder (TEX-30, Nippon Steel Works). The liquid was added more quantitatively. The supply amount was adjusted to be 5 parts by weight of the molten mixture with respect to 100 parts by weight of the resin. The mixture was mixed at a die temperature of 200 ° C. of a twin-screw extruder, and the strands were subjected to water-cooling cutting and drying to obtain thermoplastic resin composition pellets. The pellets were injected into a test piece mold for measuring various physical properties at a die temperature of 200 ° C. and a temperature of 60 ° C. using a 5 oz injection molding machine (IS100EN manufactured by Toshiba Machine Co., Ltd.) to produce a molded specimen.

This molded sample was stored at 23 ° C. and 50% humidity for 24 hours, and then its physical properties were measured by the following methods. Table 1 shows the measurement results. (1) Melt flow rate Measured based on JIS K-7210. (2) Tensile test Based on JIS K-7113, the first test piece was 20 mm
/ Min. (3) Flexural modulus 12.7 mm x 127 m based on ASTM D790
A molded specimen having a thickness of mx 6.3 mm is spanned 100 mm,
It was measured under the condition of mm / min. (4) Impact strength Based on JIS K-7110, the impact strength was measured using a 3.2 mm thick molded specimen with an Izod notch. (5) Deflection temperature under load Based on JIS K-7207, fiber stress 18.6 kg
/ Cm ² at no annealing conditions. (6) Surface resistivity The following three methods were used to measure the surface resistivity using a super-insulation meter SM-10E (manufactured by Toa Denpa Kogyo). 1) Indoor Storage Test The molded samples were stored at 23 ° C. and 50% humidity for one week, and then the surface resistivity was measured. 2) Washing test The molded specimen was placed in running water for 20 minutes, the surface was wiped with gauze, and stored at 23 ° C and 50% humidity for 2 hours, and then the surface resistivity was measured. 3) Cloth wiping test Wipe the surface of the molded sample 50 times with gauze, 23 ° C, 50%
The surface resistivity was measured under humidity.

Example 2 The procedure of Example 1 was repeated, except that lithium trifluoromethanesulfonate was used instead of lithium perchlorate. The results are also shown in Table 1.

Example 3 The procedure of Example 1 was repeated, except that 8 parts by weight of the molten mixture was supplied to 100 parts by weight of high-impact polystyrene. The results are also shown in Table 1.

Comparative Example 1 The procedure of Example 1 was repeated, except that only the high-impact polystyrene was used without adding the adduct and lithium perchlorate. The results are also shown in Table 1.

Comparative Example 2 Example 2 was repeated except that lithium perchlorate was not added and 8 parts by weight of an adduct and 100 parts by weight of high-impact polystyrene were used.
Performed similarly to 1. The results are also shown in Table 1.

Comparative Example 3 The procedure of Example 1 was repeated except that no adduct was used and 100 parts by weight of impact-resistant polystyrene and 0.8 part by weight of lithium perchlorate were used. The results are also shown in Table 1.

Example 4 9 parts by weight of the adduct prepared in Reference Example 1 and 1 part by weight of lithium perchlorate were melt-mixed at 100 ° C. Next, 100 parts by weight of low-density polyethylene (Sumikasen L705, manufactured by Sumitomo Chemical Co., Ltd.) and 2 parts by weight of the molten mixture were kneaded for 30 minutes at a temperature of 160 ° C. by Labo Plastmill (manufactured by Toyo Seiki). The kneaded material was compression-molded at 190 ° C. to prepare a 2 mm-thick specimen, which was stored at 23 ° C. and 50% humidity for 24 hours, and the physical properties were measured in the same manner as in Example-1. Table 2 shows the measurement results.

Example-5 The procedure of Example-4 was repeated except that 100 parts by weight of the low-density polyethylene and 5 parts by weight of the molten mixture were used. The results are also shown in Table 2.

Comparative Example 4 The same procedure as in Example 4 was carried out except that only the low-density polyethylene was used without adding the adduct and lithium perchlorate.
The results are also shown in Table 2.

Comparative Example-5 Low density polyethylene 10 without adding lithium perchlorate
Example 4 except that 0 parts by weight and 2 parts by weight of the adduct were used.
The same was done. The results are also shown in Table 2.

Comparative Example-6 Low density polyethylene 10 without adding lithium perchlorate
Example 4 except that 0 parts by weight and 5 parts by weight of the adduct were used.
The same was done. The results are also shown in Table 2.

Comparative Example-7 The procedure was as in Example-5, except that potassium permanganate was used instead of lithium perchlorate. The results are also shown in Table 2.

[0040]

[Table 1]

[0041]

[Table 2]

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁷ Identification symbol FI (C08L 101/00 C08L 29:04 71:02) (C08L 101/00 29:04) (56) References JP-A-4- 328167 (JP, A) JP-A-6-80886 (JP, A) JP-A-4-209646 (JP, A) JP-A-3-227357 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 1/00-101/16 C08K 3/00-13/08

Claims (5)

(57) [Claims] 1. a) 100 parts by weight of a thermoplastic resin (excluding b) below; b) 1 to 20 parts by weight of an alkylene oxide adduct of a saponified ethylene-saturated carboxylic acid vinyl ester copolymer; and c) A) a thermoplastic resin composition comprising 0.1 to 5 parts by weight of an alkali metal salt of a halogen-containing acid; 2. The thermoplastic resin composition according to claim 1, wherein a) the thermoplastic resin is a resin containing a polymer or copolymer having a styrene unit. 3. The thermoplastic resin according to claim 1, wherein b) the alkylene oxide adduct of a saponified ethylene-saturated carboxylic acid vinyl ester copolymer is an ethylene oxide adduct of a saponified ethylene-vinyl acetate copolymer. Composition. 4. The ethylene-vinyl acetate copolymer has a vinyl acetate unit content of 5 to 50% by weight and a number average molecular weight of 100.
0 to 5000; the saponification rate of the saponified ethylene-vinyl acetate copolymer is 30 to 100%; and the amount of ethylene oxide added to the saponified ethylene-vinyl acetate copolymer is ethylene-vinyl acetate copolymer. The thermoplastic resin composition according to claim 3, wherein the amount is 50 to 1,000 parts by weight based on 100 parts by weight of the combined saponified product. 5. The thermoplastic resin composition according to claim 1, wherein c) the halogen-containing alkali metal salt is lithium perchlorate or lithium trifluoromethanesulfonate.