JPS60206866A - Antistatic resin composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which has satisfactory antistatic properties and gives transparent resin products, by incorporating a specified inorg. salt in a resin. CONSTITUTION:0.01-10pts.wt. at least one inorg. salt selected from among alkaline earth metal chlorides (e.g. CaCl2), alkali metal phosphates (e.g. Na3PO4) and alkali metal nitrates (e.g. KNO3) is blended with 100pts.wt. thermoplastic resin (e.g. PE) or thermosetting resin (e.g. melamine resin) to obtain an antistatic resin compsn. having a surface resistance of 10<12>OMEGAcm or below.

Description

[Detailed description of the invention] (Technical field) The present invention relates to an antistatic resin composition.

(Prior art) Resins originally have high surface resistance and volume resistivity, and have excellent insulating properties, but on the other hand, as a result of this,
Resin is easily charged with static electricity. This charging phenomenon is
Various methods have been proposed to prevent static electricity from forming on resin, as this promotes the adhesion of dust to the surface of resin products, which not only impairs the appearance and quality of the product, but also may lead to an explosion. There is.

For example, a method of applying an ion-conductive organic substance to the surface of a resin product is known, but according to this method, the antistatic effect quickly disappears or decreases due to friction, washing, etc. of the resin surface. It is also known to knead conductive metal powder, carbon black, etc. into resin in advance. It is necessary to add a large amount of conductive particles, which deteriorates the inherent properties of the resin and causes various defects such as pinholes in the product. Furthermore, the method using conductive particles as described above makes the resin product opaque, and therefore cannot be applied to resin products that require transparency.

For this purpose, for example, in Japanese Patent Publication No. 45-580,
An antistatic resin composition has been proposed in which a small amount of a nitrogen-containing amphoteric surfactant having a specific structure and a metal salt of an organic carboxylic acid having no antistatic ability or a metal salt other than an alkali metal is added to a resin. However, since it contains a surfactant, the manufacturing cost is inevitably high.

However, the present inventors have discovered that when specific inorganic salts are blended into resins as antistatic agents, these can impart antistatic properties to the resins without the use of surfactants. This led to the invention.

(Object of the Invention) Therefore, the present invention solves the above-mentioned problems in conventional antistatic resin compositions, and by containing a small amount of antistatic agent, it has a sufficient amount of antistatic agent and a transparent resin composition. The object of the present invention is to provide an antistatic resin composition that provides a product.

(Summary of the Invention) The antistatic resin composition according to the present invention contains at least one compound selected from alkaline earth metal chlorides, alkali metal phosphates, and alkali metal nitrates based on 100 parts by weight of the resin. It is characterized by containing 0.01 to 10 parts by weight of an inorganic salt.

(Structure of the Invention) In the present invention, at least one inorganic salt selected from alkaline earth metal chlorides, alkali metal phosphates, and alkali metal nitrates is used as the antistatic agent. Specific examples of these inorganic salts include chlorides of alkaline earth metals such as calcium chloride, magnesium chloride, barium chloride, etc., phosphates of alkali metals such as sodium phosphate, potassium phosphate, etc. Examples of the nitrate include potassium nitrate and sodium nitrate.

The antistatic resin composition of the present invention contains at least one such inorganic salt, and the content thereof is 0.01 to 10 parts by weight, preferably 0.05 to 10 parts by weight, based on 100 parts by weight of the resin.
2 parts by weight. When the content of the inorganic salt is less than 0.01 parts by weight based on 100 parts by weight of the resin, the resulting resin composition does not have sufficient antistatic properties, while when it is more than 10 parts by weight, This is not preferable because it not only may impair the original properties of the resin, but also makes it difficult to uniformly disperse it in the resin, resulting in a non-uniform resin composition. It is not clear why the above-mentioned inorganic salts reduce the surface resistance of resin products and provide antistatic effects, but adding a small amount of inorganic salts can impart antistatic properties to resin compositions and improve the quality of this resin composition. An important feature of the present invention is that it can be molded into transparent resin products.

When preparing the resin composition of the present invention, the above-mentioned inorganic salt as an antistatic agent is used in its original form, that is,
It may be added to the resin in the form of powder or particles and kneaded, but
For example, dissolving the inorganic salt in an appropriate solvent such as alcohol, water, or a mixture thereof, adding this solution to the resin, and kneading is a preferred method because the inorganic salt can be uniformly dispersed in the resin. It is. Another preferred method is to dissolve the inorganic salt in advance in various surfactants, lubricants, etc. that are added depending on the resin, and then add this solution to the resin and knead it.

In the present invention, a surfactant that is conventionally known to have antistatic properties may be included in the resin together with the above-mentioned inorganic salt as an antistatic agent, within a range that does not impair the desirable properties of the resulting resin composition. I can do it.

The type of resin in the present invention is not limited at all, but examples include polyethylene, polypropylene, ethylene-propylene copolymer, polyvinyl chloride, ethylene-vinyl chloride copolymer, polystyrene, styrene-butadiene copolymer, acrylonitrile-styrene copolymer, Thermoplastic resins such as butadiene copolymer, styrene-methyl methacrylate copolymer, polyalkylene phthalate, polyamide, polyurethane, and thermosetting resins such as urea resin, melamine resin, and polyester resin are preferably used. In addition, in the present invention, the resin composition may contain a plasticizer, a lubricant, a
There is no problem even if it contains stabilizers, colorants, fillers, etc.

(Effects of the Invention) Resins usually have a high chargeability because they have a surface resistance of 1QI4ΩcII+ or more, but as described above, the resin composition of the present invention contains only a small amount of inorganic salt. , yields a resin article whose surface resistance is significantly reduced to 10" ΩG or less, and the resin article does not lose its transparency.

(Example) The resin composition of the present invention will be described below with reference to Examples. In addition, in the following examples, parts mean parts by weight, and the resin composition is molded into a sheet and its surface resistance is measured in a constant temperature room at a temperature of 30 ° C. and a humidity of 60%. The antistatic effect was evaluated.

Example 1 2 parts of magnesium chloride hexahydrate was added as an antistatic agent to 100 parts of styrene-butadiene copolymer, and after roll kneading at 180°C for 5 minutes, the temperature was 170°C and the pressure was 100k.
Press molding was performed for 5 minutes at g/cj to obtain a sheet with a thickness of 1.2 fins. The surface resistance of this sheet is shown in the table.

Comparative Example 1 In Example 1, instead of magnesium chloride hexahydrate,
A sheet with a thickness of 1.2 fl was obtained in the same manner as in Example 1 except that 2 parts of sodium chloride was used.

The surface resistance of this sheet is shown in the table.

Example 2 1 part of potassium phosphate and 0.5 part of potassium nitrate as antistatic agents were added to 100 parts of polyethylene, and the mixture was extruded at 210°C to form a sheet having a thickness of 1.0 fin. The surface resistance of this sheet is shown in the table.

Example 3 100 parts of polyvinyl chloride, 2 parts of epoxy resin lubricant, B
Add 2 parts of a-Zn stabilizer and 1 part of barium chloride as an antistatic agent, and extrude at 190°C to a thickness of 1.0
+n sheets were obtained. The surface resistance of this sheet is shown in the table.

Example 4 100 parts of polyvinyl chloride, 50 parts of dioctyl phthalate, 2 parts of Ba-Zn stabilizer, 0.3 part of magnesium chloride hexahydrate as an antistatic agent, and 0.3 part of sodium phosphate.
After adding 3 parts, the mixture was roll-kneaded at 160°C for 5 minutes, and then press-molded at 160°C and a pressure of 150g/c+a for 5 minutes to obtain a sheet with a thickness of 1.2 tm. The surface resistance of this sheet is shown in the table.

Comparative Example 2 In Example 4, a resin composition containing no magnesium chloride hexahydrate and sodium phosphate was prepared, and Example 4
A sheet with a thickness of 1.2 mm was obtained in the same manner as above. The surface resistance of this sheet is shown in the table.

Comparative Example 3 A resin composition was prepared in the same manner as in Example 4, except that 1 part of sodium sulfate was used in place of magnesium chloride hexahydrate and sodium phosphate.
．． I got two crane sheets. The surface resistance of this sheet is shown in the table.

Example 5 Acrylonitrile-butadiene-styrene copolymer 10
Add 2 parts of 50% sodium nitrate aqueous solution to 0 parts and make 17
After roll kneading at 0℃ for 5 minutes, the temperature was 170℃ and the pressure was 5 minutes.
Press molded at 0kg/cIJ for 5 minutes to a thickness of 1.2m.
I got a sheet of The surface resistance of this sheet is shown in the table.

From the above results, the surface resistances of the sheets obtained from the resin compositions of the comparative examples were all 10I3ΩcI11 or more, whereas the surface resistances of the sheets obtained from the resin compositions of the present invention were all 10' It is 2 Ωcm or less, preferably 10 Ω or less, and 1 ΩQ or less, and due to such a significant reduction in surface resistance, it has excellent antistatic properties. Moreover, according to the resin composition of the present invention, the transparency of the resin composition is not impaired.

Claims (1)

[Claims] (1) 0.01 to 100 parts by weight of at least one inorganic salt selected from alkaline earth metal chlorides, alkali metal phosphates, and alkali metal nitrates, per 100 parts by weight of the resin.
An antistatic resin composition characterized by containing 10 parts by weight.