JP2826752B2 - Antistatic composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an antistatic agent composition capable of imparting an excellent antistatic property to a polymer and an antistatic polymer composition containing the same. is there.

(Prior art and its problems) In general, polymers are widely used as molding materials such as films, molded articles, and fibers. Although these generally have excellent electrical insulation properties, they are easily charged and stored with static electricity, and may cause various obstacles and disasters. For example, as is well known, these polymer moldings are extremely liable to be contaminated by electrostatic charging, and stains are firmly adhered to cause a significant reduction in commercial value. Another major problem is the flammable explosion of flammable gas due to discharge sparks.

Conventionally, as a method of imparting antistatic properties to the polymer,
There are known a method of blending carbon black into a polymer, a method of kneading an organic antistatic agent, and a method of applying an organic antistatic agent to the surface of a polymer product. However, the former method, in which carbon black is blended, has the disadvantage that the product turns black, while the latter method, the antistatic agent on the polymer product surface is easily removed by washing with water, friction, etc., and the antistatic effect is obtained. Has the disadvantage of being lost. Also, if a large amount of antistatic agent is kneaded in for the purpose of maintaining the antistatic effect, the excess antistatic agent bleeds out over the polymer product surface over time, and the product surface becomes sticky or adheres to dust. A new problem arises.

In order to make the organic antistatic agent persistent, a method of blending an organically modified clay (an organic-inorganic composite interlayer compound obtained by inserting an organic species between layers of a smectite-type clay mineral having a layered structure) has been proposed. (JP-A-61-213231).

However, the organically modified clay is not a natural product, and is produced by combining an organic species with a specific clay mineral.

(Problems to be Solved by the Invention) The present invention relates to an inexpensive antistatic agent composition capable of imparting a long-lasting antistatic effect to a polymer molded article by a readily available additive, and a charge using the same. It is an object to provide a protective polymer composition.

(Means for Solving the Problems) Therefore, as a result of intensive studies, the present inventors have found that the combined use of an organic antistatic agent and an inorganic porous powder having a porosity in a specific range can reduce the volume resistance. The present inventors have found that the present invention has a remarkable effect, that the volume resistance does not change even when the surface of the polymer molded article is washed with water and rubbed, that good antistatic performance can be maintained and that the object can be achieved. Was.

That is, the present invention comprises (a) an organic antistatic agent and (b) an inorganic porous powder having a porosity of more than 0.75 and not more than 0.95, and (a) 0.5 to 100 parts by weight and 100 parts by weight of the polymer. (B) An antistatic agent composition characterized in that it is blended in a proportion of 2 to 100 parts by weight.

In the present invention, the inorganic porous powder used in combination with the organic antistatic agent, the porosity is more than 0.75, 0.95 or less, preferably in the range of 0.80 to 0.90, the apparent appearance of the organic antistatic agent. An inorganic powder that can be held by the bore size (adsorption collection size due to the interaction between the inner bore size and the surface shape) and has a porosity of 0.75 or less, such as kaolin (about 0.55) and a porosity of 0.95. Excluding silica gel (about 0.97). As a representative example of the inorganic powder having a porosity in this range, for example, diatomaceous earth (porosity of about 0.80 to
0.86), perlite (porosity of about 0.84 to 0.90), and vermiculite (porosity of about 0.83 to 0.90).

When the porosity is 0.75 or less, the organic antistatic agent is adsorbed and collected but has no sufficient holding effect. On the other hand, when the porosity exceeds 0.95, the organic antistatic agent is not sufficiently collected. Therefore, kaolin and silica gel which are not in the above range even if they are inorganic powders do not exhibit the effects of the present invention.

Here, the porosity refers to the ratio of voids in the bulk volume of the powder, and is expressed by the formula: porosity = (bulk volume of powder−volume of particles) / bulk volume of powder = 1−1
(Bulk density of powder / true specific gravity of powder). The bulk density of the powder is determined by thoroughly drying the powder in advance, accurately weighing the powder, dispersing the powder in a liquid (usually water), and filtering under reduced pressure to form a cake. The volume is measured and calculated by the following formula.

Bulk density = dry weight of powder / volume of cake The true specific gravity of the powder is measured according to JIS K-5101.

The blending ratio of the antistatic agent composition of the present invention to the polymer varies depending on the organic antistatic agent holding capacity of the inorganic porous powder. -100 parts by weight, preferably 2-50 parts by weight, is blended. The inorganic porous powder is 2 to 100 parts by weight, preferably 5 to 100 parts by weight of the polymer.
Preferably, 50 parts by weight are blended. When the blending amount of both is less than the above amount, the desired antistatic performance cannot be obtained, and when the blending amount of both is excessive than the above amount, the physical property strength of the polymer molded article is significantly reduced. Because.

The mixing ratio of the inorganic porous powder to the organic antistatic agent varies depending on the effect of collecting and retaining the inorganic porous powder. However, the mixing ratio of the inorganic porous powder to the organic antistatic agent 1 is 0.5 to 4 of the inorganic porous powder. It is desirable.

The method of adding the antistatic agent composition of the present invention to the polymer,
There is no particular limitation, as long as the inorganic porous powder and the organic antistatic agent coexist in the polymer molded article. That is, any method such as a method of separately adding and mixing the inorganic porous powder and the organic antistatic agent to the polymer, and a method of adding and mixing the polymer in a state where both are mixed in advance can be adopted. If the two are added to the polymer in a mixed state, the durability of the antistatic performance is excellent.

Further, the mixing of the antistatic agent composition and the polymer can be performed by the same means as the mixing of various additives to a known polymer, for example, when the polymer is a thermoplastic resin, a kneader, What is necessary is just to knead under heating with a general kneading machine, such as a mixing roll and an extruder.

When using the antistatic agent composition of the present invention to produce a desired polymer molded product, an antioxidant, an ultraviolet absorber, a lubricant, a coloring agent, a release agent, and a glass, which are usually blended with the polymer. Reinforcing agents such as fibers, fillers such as calcium carbonate, talc, clay and white carbon, flame retardants and the like may be blended. Further, a conductive filler such as metal powder, metal oxide powder, metal fiber, carbon fiber, and carbon black fine powder can be blended.

Examples of the antistatic agent used in the present invention include known anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, polymer electrolytes, and the like. If necessary, two or more kinds can be used as a mixture. Specific examples of these organic antistatic agents are as follows.

Examples of the anionic surfactant include fatty acid salts, higher alcohol sulfates, liquid fatty oil sulfates, sulfuric acids of aliphatic amines and fatty acid amides, fatty alcohol phosphates, and sulfonates of dibasic fatty acid esters. , Aliphatic amide sulfonates, alkyl allyl sulfonates, phosmarin condensed naphthalene sulfonates, and the like.

Examples of the cationic surfactant include aliphatic amines and derivatives thereof, quaternary ammonium compounds, pyridine derivatives, benzimidazole derivatives, and aliphatic amide derivatives.

As the amphoteric surfactant, betaine type, alanine type,
Imidazoline type and the like.

Examples of the nonionic surfactant include a partial fatty acid ester of a polyhydric alcohol, an alkylene oxide adduct of a higher alcohol, an alkylene oxide adduct of a fatty acid,
Examples thereof include an alkylene oxide adduct of a fatty acid amine, an alkylene oxide adduct of an alkylphenol, an alkylene oxide adduct of a partial fatty acid ester of a polyhydric alcohol, and polyalkylene glycols.

Examples of the polymer electrolyte include polyvinylbenzyltrimethylammonium chloride and sodium polystyrenesulfonate.

Specific examples of the polymer to which the antistatic effect is imparted by using the composition of the present invention are as follows.

As the thermoplastic resin, high-density polyethylene, medium-low density polyethylene, linear low-density polyethylene, polyolefins such as polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polymethyl methacrylate,
Polymethyl acrylate, copolymers containing these as main components, ethylene-vinyl acetate copolymer, polyamide, polyacetal, linear polyester, polyurethane, ABS resin, polycarbonate, noryl resin, polyphenylene sulfide, polyether sulfone, poly Methyl pentene and the like.

Examples of the thermosetting resin include an unsaturated polyester resin, an epoxy resin, a melamine resin, a phenol resin, and a diallyl phthalate resin.

Examples of the rubber include natural rubber, isoprene rubber, acrylonitrile-butadiene rubber, styrene-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, styrene-butadiene block copolymer, epichlorohydrin rubber, and chlorosulfonated polyethylene rubber.

The above-mentioned polymer can be used for a blend of two or more kinds.

(Effect of the Invention) In a polymer product using the antistatic agent composition of the present invention, the volume resistance is extremely low, the decrease in the antistatic performance due to washing with water, friction and the like is extremely small, and the excellent antistatic performance over a long period of time. Will be sustained.

The remarkable decrease in the volume resistance of the polymer product containing the antistatic agent of the present invention is caused by the small pores (apparent bore) within a specific size range on the surface of the inorganic porous powder in the polymer product. It is considered that the organic antistatic agent is adsorbed and held to form a conductive layer of the antistatic agent. In addition, since the organic antistatic agent is adsorbed and held in the fine pores on the surface of the inorganic porous powder, bleed out of the organic antistatic agent to the surface is prevented. It is considered to have excellent antistatic performance over a long period of time with little deviation of the agent.

Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

(Example 1) Diatomaceous earth (porosity 0.85) as an inorganic porous powder and diethanolamide stearate as an organic antistatic agent were added to polypropylene (melt index 10.0) at the compounding ratio shown in Table 1, and the mixture was kneaded at 220 ° C using a kneader. After melt-kneading for 10 minutes, the mixture was pelletized with a pelletizer. Next, the pellets were injection molded at 225 ° C using an injection molding machine, and the diameter was 100 m.
A polymer molded article having a thickness of 2 mm and a thickness of 2 mm was obtained and used as a test piece. The specimen was stored at 20 ° C and 60% RH, washed and dried two days after molding and two days after molding, according to JIS K-6.
The surface resistivity and the volume resistivity were measured according to 911.
The results are shown in Table 2 together with Comparative Examples 1 to 5.

(Comparative Example 1) A test piece was obtained in the same manner as in Example 1 except that diatomaceous earth was not used.

(Comparative Example 2) A test piece was obtained in the same manner as in Example 1 except that stearic acid diethanolamide was not used.

(Comparative Example 3) A test piece was obtained using only polypropylene without adding any additive.

(Comparative Examples 4 and 5) A test was performed in the same manner as in Example 1 except that diatomaceous earth was replaced with kaolin (porosity 0.55; manufactured by Engelhard Co.) and silica gel (porosity 0.97; manufactured by Mizusawa Chemical Industry Co., Ltd.). I got a piece.

As is clear from Table 2, the addition of diatomaceous earth alone does not improve the antistatic performance, but the combined use of an organic antistatic agent and diatomaceous earth significantly improves the antistatic performance due to the improvement in volume resistance and surface resistance. I understand. In addition, it can be seen that the volume resistance has a remarkable effect that does not decrease even after washing with water.

(Examples 2 to 5) Pearlite (porosity: 0.90) or vermiculite (porosity: 0.87) as inorganic porous powder, monoglycerin stearate as an organic antistatic agent, and DOP (reagent grade 1) as a plasticizer were tertiary. In addition to the soft polyvinyl chloride in the proportions shown in the table, heat roll at about 150 ℃ 10
After kneading for a minute, the mixture was formed into a sheet. 50 g of the kneaded and sheeted sample is placed in a mold (2.5 mm × 120 mm × 120 mm), compressed and molded by hot pressing at 160 ° C, 25 kg / cm ² for 2 minutes, and then pressed to 100 ° C. After cooling, the molded sheet was taken out and used as a test piece. The test specimen was stored at 20 ° C. and 60% RH, washed and dried two days after molding and two days after molding, and the surface resistivity and volume resistivity were measured in accordance with JIS K-6911. The results are shown in Table 4 together with Comparative Examples 6 to 8.

(Comparative Example 6) A test piece was obtained in the same manner as in Example 2 except that pearlite was not used.

(Comparative Example 7) A test piece was obtained in the same manner as in Example 2 except that monoglycerin stearate was not used.

(Comparative Example 8) Polyvinyl chloride and D were added without adding any additives other than DOP.
A test piece was obtained only with OP.

As is clear from Table 4, the addition of pearlite or vermiculite alone does not improve the antistatic performance. However, when an organic antistatic agent and perlite or vermiculite are used in combination, the antistatic performance is improved due to the improvement in volume resistance and surface resistance. It can be seen that it is significantly improved. In addition, it can be seen that the volume resistance has a remarkable effect that does not decrease even after washing with water.

Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) C09K 3/16 C08K 3/00 C08K 5/00 C08K 13/02 CA (STN) WPI / L (QUESTEL)

Claims (2)

(57) [Claims] (1) an organic antistatic agent (a) and a porosity (b) of less than 0.1;
More than 75, comprising an inorganic porous powder of 0.95 or less, wherein the inorganic porous powder is one or a mixture of diatomaceous earth, perlite, vermiculite, and (a) 0.5 to 100 parts by weight of the polymer. An antistatic composition comprising 100 parts by weight and (b) 2 to 100 parts by weight. 2. An organic antistatic agent (a) is added to 100 parts by weight of the polymer.
0.5 to 100 parts by weight and (b) 2 to 100 parts by weight of an inorganic porous powder having a porosity of more than 0.75 and 0.95 or less composed of one or a mixture of two or more kinds of diatomaceous earth, perlite, and vermiculite Or an antistatic polymer composition characterized by being preliminarily mixed and blended.