JPS5936159A - Antistatic composition and antistatic film, sheet, or formed item - Google Patents

Abstract

PURPOSE:To provide titled composition, film, sheet, and formed item of high performance, comprising a thermoplastic polymer, water-soluble thermoplastic polymer or polyhydric alcoholic compound, and polystyrenesulfonic acid salt. CONSTITUTION:The objective composition comprising (A) 100pts.wt. of a thermoplastic polymer (an ethylene ionomer having ethylene, alpha,beta-ethylenic unsaturated carboxylic acid, and its metal salt), (B) 2-60pts.wt. of a hydroxyl group- carrying water-soluble thermoplastic polymer or polyhydric alcoholic compound, and (C) 10-40pts.wt. of a polymer constituted by a recurring unit of formula (R is H, or methyl; M is H, alkali metal, etc.; R1, R2, R3, and R4 are each H, halogen, alkyl, or alkoxyl). This composition will be subjected to forming into film, sheet, etc. with a surface resistivity <=10<13> ohms.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antistatic composition of various thermoplastic plastic polymers such as polyolefin, polystyrene, and polyvinyl chloride, and an antistatic film, sheet, or molded article made from the composition. More specifically, a thermoplastic polymer composition with good antistatic properties in which polystyrene sulfonate is uniformly mixed, and an antistatic film made of the composition.

Regarding sheets or molded products.

In recent years, the number of product fields that require antistatic properties has become extremely widespread. Examples include packaging for pharmaceuticals, cosmetics, and foods, covers for packaging machines, dust prevention curtains for clean rooms and operating rooms, sheets, packaging for precision equipment, and packaging for semiconductors.

Particularly in packaging for semiconductors, metal oxide film semiconductor circuits are destroyed by static electricity generated on the surface of the packaging film, so low-resistance packaging films and sheets are required.

In addition, when metal oxide film semiconductor circuits are exported or imported, static electricity is generated when the package is opened due to contents inspection at customs and is often destroyed. It is also necessary to be able to see the contents.

Conventionally, methods have been adopted in which surfactants, conductive carbon black, and metals are added to impart antistatic properties to polymeric substances.

Conventional surfactants are relatively easy to migrate, based on the idea that the antistatic IF effect can be achieved by migrating and arranging the surfactants from the inside of a polymeric substance to the surface. It consists primarily of low molecular weight surfactants. However, polymeric substances to which surfactants have been added are not suitable for long-term use because the surfactants may be removed from the surface of the polymeric substance during handling or washed off due to adhesion of moisture. Couldn't use it.

In addition, polymer materials to which carbon black or metal powder is added have the disadvantage that the carbon black or metal powder is missing from the polymer material, contaminating the packaged items in packaging applications, and its opacity limits its use. It was something to do.

On the other hand, polymeric antistatic agents, such as alkylene oxide derivatives with a specific structure, are rarely used in practical use, with a limited temperature of ℃.

In particular, it is completely unknown to use a polymer type antistatic agent having an anion group that has poor compatibility with polymer substances.

On the other hand, as anionic antistatic agents for surface treatment, metal salts such as sodium polystyrene sulfonate have been known for a long time.
No. 6 discloses that a type of oligostyrene sulfonate copolymerized with a special monomer is effective as a low-resistance treatment agent for paper and sheets. However, these were developed for surface treatment, and the treatment agents described in the examples have poor compatibility as antistatic agents for blending with polymeric substances, so they are of no practical use.

In particular, processing agents with a high degree of sulfonation that have low resistance lack molecular flexibility, so even if they are blended with polymer substances, they are not mixed uniformly and cannot exhibit their excellent antistatic ability. It was not used as an antistatic agent for compounding substances.

The present inventor has already proposed in Japanese Patent Application No. 57-30540 that excellent antistatic properties can be imparted by uniformly mixing a polystyrene sulfonate into a thermoplastic polymer. However, it took several days to one month for the composite acid to exhibit its antistatic effect.

As a result of intensive research in order to solve the above problem, the inventor of the present invention found that in the case of creating a composition in which a larger amount of thermoplastic polymer is used than in Japanese Patent Application No. 57-30540, after molding, The present invention was achieved based on the discovery that the time required to develop an antistatic effect is significantly shortened, and that it is possible to obtain a film, sheet, or molded product that exhibits homogeneous mixing and mechanical properties that are sufficiently usable for practical use. did.

That is, the present invention comprises: (a) a thermoplastic polymer 100 layer; and (b)
2 to 60 parts by weight of a water-soluble thermoplastic polymer or polyhydric alcoholic compound having a hydroxyl group; Yes, R,
, R2, R8, and R4 are each the same or different from each other, and are hydrogen, ), rogene, an alkyl group, or an alkoxyl group) More than 10 parts by weight but not more than 40 parts by weight a thermoplastic polymer composition formed from the composition;
An antistatic film, sheet, or molded product with a surface resistivity of 1013Ω or less.

Next, each component constituting the present invention will be explained.

General formula (However, 几 + M, R,, R, 2, R3, and R,
Polymers having repeating units (4 as described above) as essential constituent units are polymeric sulfonic acid salts or polymeric sulfonic acids having different sulfonic group introduction rates. Although there is no restriction on the rate of introduction of sulfone groups, it is desirable that the rate of introduction be 40-100 mol%, preferably 50-100 mol%, in view of conductivity and water solubility. Naturally, polymers of styrene sulfonate monomers or copolymers with styrene, methacrylic acid (salt), acrylic acid (salt), and fumaric acid (salt) are also included. Regarding the molecular weight, although it is not particularly important, the molecular weight is preferably 10 to 5 million, from the standpoint of compatibility with thermoplastic resins, the preferred molecular weight is 2000 to 500,000, and more preferably 3000 to 500,000.
The range is oo.

Furthermore, poly(halogenated styrene) sulfonate, poly(alkylated styrene) sulfonate, poly(alkoxylated styrene) sulfonate, poly(halogenated styrene) sulfonate having a substituent on the aromatic ring of polystyrene sulfonate, poly(alkoxylated styrene) sulfonate, α−
It also includes methylstyrene) sulfonate. The counter ion of the polymer is one or a mixture of two or more selected from hydrogen, alkali metals, alkaline earth metals, and ammonium.

Methods for obtaining the polymeric sulfonate or polymeric sulfonic acid in the present invention are well known in the art. An example of the manufacturing method is shown below.

(4) Polystyrene sulfonic acid obtained by reacting polystyrene with a sulfonating agent such as sulfuric anhydride or chlorosulfonic acid in a solvent such as carbon tetrachloride or ethylene dichloride, and an ammonium compound or an ionic alkali metal. A method of neutralizing polystyrene sulfonate using a compound or an ionic alkaline earth metal compound. For example, from 1971 onwards
See Publication No. 37226.

(B) Using a free radical initiator, styrene sulfonate, vinyl aromatic compounds such as styrene, chlorostyrene, tertiary-butylstyrene, acrylonitrile, methacrylic acid (salt), acrylic acid (salt), fumaric acid (salt),
A method of copolymerizing with etc. For example, see Japanese Patent Application Laid-Open No. 14820/1983.

The amount of polymer sulfonate and/or polymer sulfonic acid to be blended with respect to 100 parts by weight of the thermoplastic polymer is more than 10 parts by weight and not more than 40 parts by weight, preferably more than 10 parts by weight and not more than 30 parts by weight. is the amount of If it is less than 10 parts by weight, it takes a long time to develop the antistatic effect, which is not preferable. If the amount exceeds 40 parts by weight, a large amount of the third component, a water-soluble thermoplastic polymer having a hydroxyl group or a polyhydric alcoholic compound, is added, resulting in a decrease in the mechanical properties of the thermoplastic resin, which is preferable. do not have.

A water-soluble thermoplastic polymer having a hydroxyl group has a saponification degree of 3
Cellulose having two or more substituents, such as polyvinyl alcohol with a content of 0 to 70 mol%, hydroxyglobil cellulose with a propylene oxide addition rate of 25 or more, hydroxyethyl cellulose with an ethylene oxide addition rate of 2.0 or more, and methylhydroxypropyl cellulose. It is a derivative.

Moreover, there is no particular restriction on the molecular weight. Polyhydric alcoholic compounds include 1.2-ethanediol, 1.3-propanediol, 1.2-propanediol, 14-butanediol, 1.6-hexanediol, glycerin,
aliphatic polyhydric alcohols such as pentaerythritol;
These include cyclic polyhydroxy compounds such as cyclohexanediol, natural polyhydric alcohols such as hydriclucose, D-xylose, J]-sorbitol, fructose, and mannitol.

The amount of the water-soluble thermoplastic polymer or polyhydric alcoholic compound having a hydroxyl group added is in the range of 2 to 60 parts by weight, preferably 4 to 40 parts by weight, per 100 parts by weight of the thermoplastic resin. . If the amount is less than 2 parts by weight, a thermoplastic polymer in which the polymeric sulfonic acid salt and/or polymeric sulfonic acid are uniformly dispersed cannot be obtained. If it exceeds 60 parts by weight, it is not preferable because it may not be able to be mixed into the thermoplastic resin or its mechanical strength will be reduced. The amount of the water-soluble thermoplastic polymer or polyhydric alcoholic compound having a hydroxyl group is in the range of 20 to 600 parts by weight, preferably 30 to 200 parts by weight, based on 100 parts by weight of the polystyrene sulfonate.

Thermoplastic resins include polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene ionomer, chlorinated polyethylene, and derivatives thereof; polystyrene,
Polystyrenes and copolymers thereof such as acrylonitrile-styrene copolymer, acrylonitrile-styrene-butadiene copolymer, polyacid-resistant vinyls, polyvinyl formal, polyacetal, polyvinyl butyral,
Polyamides such as nylon 6.6, 6.6, and 10.12 and their derivatives; polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene terephthalate-polyethylene glycol block copolymers; polyvinyl chloride and its derivatives; Polymers, polyvinylidene chloride and its copolymers, polymethyl methacrylates, acrylic ester copolymers, polycarbonates, polysulfones, styrene
Examples include rubbers such as butadiene block copolymers, thermoplastic polyurethanes, polybutadiene, polyisoprene, acrylonitrile-butadiene copolymers, and polyphosphacenes.

Preferred thermoplastic polymers include polyethylene, polypropylene, and ethylene-vinyl acetate from the viewpoint of IJ lux. Examples include polyolefins such as copolymers, ethylene-methacrylic acid copolymers, and ethylene ionomers, or copolymerized polyolefins and derivatives thereof.

More preferable thermoplastic polymers include ethylene and α , β-ethylenically unsaturated carboxylic acid, and an α,β-ethylenically unsaturated carboxylic acid metal salt.

The thermoplastic polymer composition of the present invention can be produced by using a water-soluble thermoplastic polymer having a hydroxyl group or a polyhydric alcohol in an aqueous solution of a polymeric sulfonic acid salt and/or a polymeric sulfonic acid. A preferred method is to mix an aqueous solution containing the compound and a thermoplastic resin, heat and melt the mixture, and simultaneously dehydrate the composition.

There are various methods for mixing the components of the present invention, but
Each component can be mixed using a conventional melt mixer such as a Panbury mixer or an extruder.

The melt mixing temperature is the melt softening temperature of the thermoplastic polymer 100
It can be arbitrarily selected within the range of ~350°C.

The composition of the present invention can be used in various molded products such as radio and television cases, parts, lighting equipment parts, plastic containers, films, sheets, foams, filaments, staples, textile products such as cloth, and synthetic paper. These are all things that require antistatic protection.

Since the thermoplastic polymer composition according to the present invention contains a water-soluble thermoplastic polymer having a hydroxyl group or a polyhydric alcoholic compound, the polymer sulfonate and/or polymer sulfonic acid are extremely uniform. This is an excellent composition that exhibits low surface resistivity and good antistatic properties immediately after molding. Further, since the film, sheet or molded article formed from the composition has a surface resistivity of 10,130 or less, it is useful as a variety of products requiring antistatic properties. In particular, since the film is transparent or translucent, it is extremely useful as a packaging material that allows the contents to be confirmed.

Next, the effects of the present invention will be explained in more detail with reference to Examples. In the examples, parts and percentages are by weight. Measurement of surface resistivity was carried out at 23° C. and 50% relative humidity.

Example I A mixed aqueous solution prepared by adding 8 parts of glycerin to 40 parts of a 30% aqueous solution of sodium polystyrene sulfonate with a degree of sulfonation of 60 mol% (trade name: Oligo 2° Pressure Paper Mill) was added to an aqueous solution of ethylene-methacrylic acid copolymer. Addition and mixing to 100 parts of a magnesium type ionomer (methacrylic acid content: 35 mol%, degree of neutralization of magnesium ions: 25 mol%) was carried out, melt-mixed using a 30 mm twin screw extruder, and then a film with a thickness of 100 μm was formed using an inflation film forming method. Manufactured. This phthalm was uniform and had a haze of 25%. The surface resistivity was 6×1.07Ω one hour after film formation.

The tensile strength at break was 220 kg/cm2, and it was usable for practical use. The surface resistivity of this ionomer alone was 10<16 >[Omega] or more.

Example 2 A mixed aqueous solution prepared by adding 17 parts of glycerin to 70 parts of a 30% aqueous solution of sodium polystyrene sulfonate having a degree of sulfonation of 60 mol % (trade name: Oligo 2° Pressure Paper Mill) was prepared by adding 17 parts of glycerin to it.
The mixture was added to 100 parts of thorium-type ionomer of ethylene-methacrylic acid copolymer (methacrylic acid content: 51 mol%, sodium ion neutralization degree: 35 mol%), melt-mixed using a twin-screw extruder, and then mixed using an injection molding machine. Thickness 3mm
sheets were manufactured. The sheet was uniform and had a surface resistivity of 5×10 7 Ω one hour after molding. In addition,
The surface resistivity of the ionomer alone used in this example was 16Ω or more.

Example: 3 A mixed aqueous solution prepared by adding 18 parts of glycerin to 100 parts of a 35% aqueous solution of potassium polystyrene sulfonate (degree of sulfonation 60 mol%) was added to a sodium-type ionocarbon of ethylene-methacrylic acid copolymer (methacrylic acid content 67 mol %, sodium ion neutralization degree 35 mol %) was added and mixed and melt-mixed in a twin-screw extruder, and then a film with a thickness of 70 μm was produced by an inflation film forming method.

The film was uniform and had a haze of 20%.

The surface resistivity was 3×]07Ω one hour after film formation. The tensile strength at break was 280 kg/cm2, and it was usable for practical use. Note that the surface resistivity of the ionomer alone used in this example was 1016Ω or more. Also, the thickness obtained by compression molding this composition is 05III+I
The surface resistivity of the + sheet was 1×108Ω. In addition, by hot deep drawing this sheet, a diameter of 3
A molded product with no uneven thickness and having holes of 2 cm and 2 cm in depth was obtained.

Comparative Example 1 After adding and mixing 18 parts of glycerin to 100 parts of the sodium type ionomer used in Example 3, a film was formed in the same manner as in Example 3 to obtain a film with a thickness of 70 μm. The surface resistivity of this film was 5×10 13 Ω, and the glycerin migrated to the film surface, making the film quite sticky.

Comparative Example 2 After adding and mixing 100 parts of a 35% aqueous solution of potassium polystyrene sulfonate (degree of sulfonation 60 mol%) to 100 parts of the sodium type ionomer used in Example 3, a film was formed in the same manner as in Example 3. A film with a thickness of 70 μm was obtained. This film was an opaque film in which potassium polystyrene sulfonate was dispersed, and its mechanical strength was 20 kg/cm2 in tensile strength, making it impossible to put it to practical use. Note that the surface resistivity of this film was 4×10 7 Ω.

Comparative Example 3 10 parts of a 35% aqueous solution of potassium polystyrene sulfonate (degree of sulfonation 60 mol%) and 18 parts of glycerin were added and mixed to 100 parts of the sodium type ionomer used in Example 3, and the mixture was melt-mixed using a twin-screw extruder. Next, a film with a thickness of 70 μm was manufactured by an inflation film forming method. The surface resistivity was 3×1 OI3Ω one hour after film formation, but was not observed 10 days later.

Example 4 After drying a mixed aqueous solution in which 20 parts of polyvinyl alcohol with a degree of saponification of 50 mol% was added to 100 parts of a 15% aqueous solution of lithium polystyrene sulfonate (degree of sulfonation 60 mol%), powdered potassium polystyrene sulfonate was prepared. 35 parts of polyvinyl alcohol mixture were obtained. 35 parts of the mixture and 100 parts of low density polyethylene were melt-mixed, and a film having a thickness of 100 μm was formed in the same manner as in Example 1.

This film exhibited a surface resistivity of 5×10 7 Ω one hour after deposition. In addition, the surface resistivity of the low density polyethylene alone used in this example was 1016Ω or more, and 20 parts of polyvinyl alcohol and 100 parts of low density polyethylene were used.
The surface resistivity of the film obtained from the composition consisting of

Example 5 20% aqueous solution 6 of a copolymer with a weight ratio of sodium styrene sulfonate and sodium fumarate of 80:2o
After mixing 4 parts of ethylene glycol with 4 parts of ethylene glycol, the mixture obtained by dehydration was added and mixed with 100 parts of plasticized polyvinyl chloride, and a film with a thickness of 60 μm was produced by an inflation film forming method.

This film was uniform and had a surface resistivity of 1 x 1080 1 hour after film formation. In this example, the surface resistivity of plasticized polyvinyl chloride alone was 7
The OI was 3Ω.

Example 6 3 of polystyrene sulfonic acid with a degree of sulfonation of 60 mol%
1.9% aqueous solution (trade name Oligo 2. Manufactured by Pressure Paper Mill) 50
15 parts of hydroxyglopyl cellulose (propylene oxide addition rate: 4.0 mol) were added to the mixture, mixed, and dried to obtain a powder. 30 parts of the powder was mixed with 100 parts of nylon-6 resin.
After melt-mixing, a sheet with a thickness of 3 mm was manufactured using an injection molding machine. This sheet was uniform and had a surface resistivity of 2 x 1070 one hour after molding. The surface resistivity of the nylon-6 resin used in this example alone is I
The resistance was 10”Ω.

Applicant: Asahi Dow Co., Ltd. Agent Yutaka 1) Yoshio

Claims (1)

[Scope of Claims] 1. (a) 100 parts by weight of a thermoplastic polymer; (I) 2 to 60 parts by weight of a water-soluble thermoplastic polymer or polyhydric alcoholic compound having hydroxyl groups; (c ) General formula (where R is hydrogen or a methyl group, M is hydrogen, an alkali metal, an alkaline earth metal, or ammonium, and R
,,RQ,几. , R4 are the same or different from each other and are hydrogen, halogen, an alkyl group, or an alkoxyl group) as a constituent unit. Plastic polymer composition. 2. The thermoplastic polymer is an ethylene ionomer containing ethylene, an α,β-ethylenically unsaturated carboxylic acid, and a (χ,β-ethylenically unsaturated carboxylic acid metal salt), according to claim 1. Composition. 3. (100 parts by weight of aJ thermoplastic polymer, (b) 2 to 60 parts by weight of a water-soluble thermoplastic polymer or polyhydric alcoholic compound having a hydroxyl group, (c) general formula (however, R is hydrogen or a methyl group, M is hydrogen, an alkali metal, an alkaline earth metal or ammonium,
More than 10 parts by weight of a polymer having as a constituent unit a repeating unit in which each of R,, R2, R8, and R4 is the same as or different from each other and represents hydrogen, halogen, an alkyl group, or an alkoxyl group. There are antistatic films and sheets with a surface resistivity of 1013 Ω or less, consisting of 1 part by weight or less (・ is molded 4, the thermoplastic polymer is ethylene and α,
The antistatic film, sheet, or molded product according to claim 3, which is an ethylene ionomer containing β-ethylenically unsaturated carboxylic acid and α,β-ethylenically unsaturated carboxylic acid metal salt. .