JPH10176079A - Inorganic antistatic filler, resin composition containing the same and production of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject filler capable of imparting an effect as a filler and also an excellent antistatic effect having an endurance to a plastic, a rubber, etc., on adding the same to them by consecutively coating the same with a dispersing agent and an antistatic agent so as to form a double adsorption- layered structure. SOLUTION: This inorganic antistatic filler is obtained by applying (B) a layer of an organic dispersing agent such as a water soluble anionic or cationic highly polymeric surfactant having 1000-150000 weight averaged molecular weight on (A) the surface of an inorganic filler such as calcium carbonate, and then applying (C) an organic antistatic agent layer on the layer of the component (B). The filler is obtained e.g. by wet crushing 100 pts.wt. powdery granules of the component (A) (e.g. having 2-2000μm) in the presence of the component (B) to obtain a slurry having 2μm mean particle diameter, drying the slurry, adding 0.5-15 pts.wt. component (C) thereto and mixing them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antistatic inorganic filler which has an antistatic effect by itself, and which can be imparted with an antistatic property by adding to plastics or rubbers. And a method for producing the inorganic filler.

2. Description of the Related Art Conventionally, fillers used for filling plastics and rubbers are used after being surface-treated with a hydrophobic substance such as stearic acid in order to increase compatibility with a matrix such as plastics. . Since plastic and rubber filled with these fillers are easily charged, it is common to add an antistatic agent separately to plastic or rubber. Also, recently, for example,
As disclosed in JP-A-136849 and JP-A-59-138267, attempts have been made to previously surface-treat an antistatic agent to a filler used for filling plastic or rubber. However, at present, even if an antistatic agent is added separately, particularly in the case of easily chargeable plastics such as polyethylene and polypropylene, the surface electric resistance and the volume resistance are not easily reduced, and a sufficient antistatic effect may not be obtained. Many. Even if the desired antistatic effect is obtained by lowering the surface electric resistance or the like, there is a problem that the antistatic agent is largely transferred to the surface, the effect is temporary, and there is no durability.

[0002]

An object of the present invention is to provide an inorganic filler having an antistatic property which can be added to plastics and rubbers to provide a durable and excellent antistatic property as well as an effect as a filler. With the goal. Another object of the present invention is to provide a resin composition containing such an inorganic filler. The present invention
It is another object of the present invention to provide a method for producing an antistatic inorganic filler.

[0003]

According to the present invention, when the inorganic filler is wet-pulverized in the presence of a dispersant which is a water-soluble surfactant and then treated with an antistatic agent, the surface of the inorganic filler is dispersed. It has been made based on the finding that the above problem can be solved by using an inorganic filler having such a double adsorption layer structure (double layer), which is sequentially covered with an agent and an antistatic agent. That is, the present invention provides an antistatic inorganic filler obtained by applying an organic dispersant to the surface of an inorganic filler and applying an organic antistatic agent on the organic dispersant. The present invention also provides a resin composition containing the above-mentioned inorganic filler.
The present invention also provides a method for producing an inorganic filler, which comprises wet-grinding an inorganic filler in the presence of an organic dispersant, drying and mixing an organic antistatic agent. The present invention also wet-grinds the inorganic filler in the presence of an organic dispersant, adding an organic antistatic agent to the obtained ground slurry,
Next, the present invention provides a method for producing an inorganic filler, which is characterized by drying.

[0004]

BEST MODE FOR CARRYING OUT THE INVENTION The inorganic fillers targeted in the present invention include heavy calcium carbonate, light calcium carbonate,
Examples thereof include one or a mixture of two or more of various inorganic substances such as talc, sericite, calcium sulfate, montmorillonite, zeolite, calcium sulfite, aluminum hydroxide, aluminum oxide, zinc oxide, barium sulfate, and kaolin. Of these, calcium carbonate, particularly heavy calcium carbonate, is preferred. In the present invention, such an inorganic filler can be wet-pulverized immediately, but it is preferable to dry-pulverize the inorganic filler before the wet pulverization. At this time, it is preferable to pulverize the inorganic filler to have a particle diameter of 40 mm or less, preferably an average particle diameter of about 2 mm to 2 μm. In the present invention, first, an organic dispersant is applied to the surface of the inorganic filler. This can be performed by various methods, but is preferably performed by wet grinding the inorganic filler in the presence of the organic dispersant.

Specifically, the inorganic filler is added to the aqueous medium so that the weight ratio of the inorganic filler to the aqueous medium (preferably water) is in the range of 70/30 to 30/70, preferably 60/40 to 40/60. A medium is added, and 0.01 to 5 parts by weight, preferably 0.01 to 0.7 parts by weight, based on 100 parts by weight of the inorganic filler, is added as a solid content of the dispersant, and wet pulverization is performed by a conventional method. Alternatively, an aqueous medium obtained by previously dissolving a dispersant having an amount in the above range is mixed with an inorganic filler, and wet-pulverized by a conventional method. The wet pulverization may be a batch type or a continuous type, and it is preferable to use a mill using a pulverizing medium such as a sand mill, an attritor, and a ball mill.
By wet grinding in this way, the average particle size is 2 μm
Hereinafter, those having an average particle size of preferably 1 to 0.3 μm are obtained. Examples of the organic dispersant used here include a water-soluble cationic surfactant (A), a water-soluble anionic surfactant (B), and a water-soluble nonionic surfactant (C).

The water-soluble cationic surfactant (A) used as an organic dispersant includes primary, secondary and tertiary amine salt type cationic low molecular or high molecular weight surfactants and quaternary ammonium salt type cationic surfactants. Examples include low molecular or high molecular surfactants. Examples of the primary to tertiary amine salt type low molecular surfactants include higher alkylamine salts, higher alkylamine ethylene oxide adducts, higher alkylamine ethylene oxide / propylene oxide adducts, solomin A type amine salts, and sapamin A type. An amine salt, an Arkover A type amine salt, an imidazoline type amine salt and the like can be mentioned. Examples of the quaternary ammonium salt type low molecular surfactant include higher alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts, sapamin type quaternary ammonium salts, imidazoline type quaternary ammonium salts, and alkylpyridium salts. Can be

[0007] Examples of the primary to tertiary amine salt type polymer surfactants include polyethyleneimine, polyalkylene polyamine salts, polyamine / dicyandiamide condensed salts, and polydiallylamine salts. Examples of the surfactant include polystyrene methylaminotrimethylammonium salt, polydiallyldimethylammonium salt, trimethylaminoethyl (meth) acrylate ammonium salt, and polyN-alkylpyridine salt. When calcium carbonate is used as a filler among these cationic surfactants, for example, an amine salt type polymer surfactant or a quaternary ammonium salt type polymer surfactant is required to obtain a high concentration slurry during wet pulverization. Agents are preferred, and particularly preferred are salts of diallylamine alone or copolymers with vinyl compounds and polydiallyldimethylammonium salts. As such a polymer dispersant, a water-soluble cationic copolymer dispersant described in JP-A-7-300568 is preferable. JP-A-7-300
The description of the water-soluble cationic copolymer dispersant in JP 568 is included in the description of the present specification.
These molecular weights are not particularly limited, but are preferably 10
00 to 150,000, more preferably 5,000 to
80,000.

The water-soluble surfactant (B) used as the organic dispersant includes low-molecular or high-molecular surfactants having carboxylate, sulfate, sulfonate and phosphate as functional groups. Can be Examples of the low-molecular carboxylate include higher fatty acid salts such as sodium laurate, sodium stearate and sodium oleate, higher alcohol polyethylene oxide ether acetate, perfluoroalkyl carboxylate, and the like. Are, for example, polyacrylic acid salts, carboxylic acid monomers such as salts of polyacrylic acid-maleic acid copolymers alone or copolymers comprising at least two or more salts thereof, vinyl compounds and carboxylic acid monomers And a carboxymethylcellulose and a copolymer thereof with a body or a salt thereof. Examples of the low molecular sulfate ester salt include higher alcohol polyethylene oxide sulfate salt, sulfated oil, sulfated fatty acid ester, sulfated fatty acid, sulfated olefin, and alkylphenol polyethylene oxide sulfate salt.

Examples of the low molecular sulfonate include alkylbenzene sulfonate, α-olefin sulfonate, alkane polysulfonate, perfluoroalkyl sulfonate, Igephone T type and aerosol type, etc. Examples of the salt include a formalin condensate of a naphthalene sulfonate, a polystyrene sulfonate, a polyvinyl sulfonate, a polyaryl sulfonate, and a salt of a copolymer of acrylamide and acrylamidopropanesulfonic acid. Examples of the copolymerizable polymer surfactant include a copolymer composed of a carboxylic acid monomer and a sulfonic acid monomer or a salt thereof. Examples of the low molecular phosphate ester salt include a higher alcohol monophosphate ester salt, a higher alcohol polyethylene oxide phosphate ester salt and an alkylphenol polyethylene oxide phosphate ester salt.

[0010] Among these anionic surfactants, for example, when calcium carbonate is used as a filler, a polymer type surfactant is preferable in order to obtain a high-concentration slurry at the time of wet pulverization. A carboxylic acid monomer such as acrylic acid or a salt thereof, a polyacrylic acid-maleic acid copolymer or a salt thereof, or a copolymer composed of at least two or more of them or a salt thereof is exemplified. These molecular weights are not particularly limited, but are preferably from 1,000 to 100,000, and more preferably from 5,000 to 50,000. Examples of the water-soluble surfactant (C) used as the organic dispersant include polyethylene glycol type and polyhydric alcohol type nonionic surfactants. As polyethylene glycol type, for example, higher alcohol ethylene oxide adduct,
Examples thereof include an alkylphenol ethylene oxide adduct, a fatty acid ethylene oxide adduct, a polyhydric alcohol fatty acid ester ethylene oxide adduct, a fatty acid amide ethylene oxide adduct, a polypropylene glycol ethylene oxide adduct, and a polyether modified silicone.

Examples of the polyhydric alcohol type include glycerol fatty acid ester, pentaerythritol fatty acid ester, sorbitol and sorbitan fatty acid ester, sucrose fatty acid ester, polyhydric alcohol alkyl ether, polyglycerin fatty acid ester and ethylene oxide thereof. Adducts and fatty acid amides of alkanolamines; and methylcellulose (MC), hydroxyethylcellulose (HE
C), polyvinyl alcohol (PVA), polyalkylene oxide vinyl ether compound, polyhydroxylalkyl (meth) acrylate, and the like. Among these nonionic surfactants, for example, when calcium carbonate is used as a filler, in order to obtain a high-concentration slurry at the time of wet pulverization, a polymer type surfactant is preferable. Partially saponified poplar and polyhydroxyalkyl (meth) acrylate.

In the present invention, after the wet pulverization, an organic antistatic agent is then applied to the surface to obtain an antistatic inorganic filler. For example, (1) wet grinding and drying followed by mixing with an organic antistatic agent, or (2) wet grinding followed by adding an organic antistatic agent to the resulting milled slurry and then drying. Is preferred. Specifically, (1)
In the method, after the wet pulverization, drying, crushing, and classification, and then using a Henschel mixer or a ribbon mixer, an organic antistatic agent (preferably, a cationic antistatic agent and / or a nonionic antistatic agent) is used. It is preferable to mix to prepare the antistatic inorganic filler of the present invention. In the method (2), after the wet pulverization, an organic antistatic agent (anionic antistatic agent, cationic antistatic agent and / or nonionic antistatic agent, preferably anionic antistatic agent) is added to the obtained pulverized slurry. Is added, mixed and stirred, then dried, crushed, and classified to prepare the antistatic inorganic filler of the present invention. In this method, when a cationic antistatic agent and / or a nonionic antistatic agent are used, the crushing step and the classification step after drying can be omitted.

The drying in the above-mentioned method can be carried out by a known method such as hot air drying or powder jet drying, but is preferably carried out by fluidized drying with a medium. Fluid drying of the medium
The slurry material is supplied to the media particles (fluidized bed) in a fluidized state by hot air in the drying tower, and the supplied slurry material adheres to the surface of the actively fluidized media particles in a film form. In this method, various substances are dried while being dispersed in a fluidized bed and subjected to a drying action by hot air.
Such medium fluid drying can be easily performed using, for example, a medium fluid drying device or a media slurry dryer manufactured by Nara Machinery Co., Ltd. It is preferable to use the medium fluidized drying because the drying and the formation of the primary particles of the aggregated particles are simultaneously performed.

The following are examples of the organic antistatic agent used in the above method, that is, the cationic antistatic agent, anionic antistatic agent and nonionic antistatic agent. As the organic cation antistatic agent, a water-soluble surfactant (A) used as a dispersant can be used, and particularly preferred are a water-dispersible or water-soluble alkylamine ethylene oxide adduct, and alkylamine ethylene oxide / propylene. An adduct and a quaternary ammonium salt type cationic low molecular surfactant are mentioned. As the organic anion antistatic agent, a water-soluble surfactant (B) used as a dispersant can be used. Particularly preferred are a water-dispersible or water-soluble functional group such as sulfate, sulfonate and phosphoric acid. A low molecular surfactant having an ester salt is exemplified. As the organic anion antistatic agent, a water-soluble surfactant (C) used as a dispersant can be used, and examples thereof include those having the same composition and being water-dispersible. Particularly preferred are HLBs 8-13.
Polyhydric alcohol type nonionic surfactants, partially saponified popals having a low degree of polymerization, and polyhydroxyalkyl (meth) acrylate.

In the present invention, the organic antistatic agent is preferably used in an amount of 0.5 to 15 parts by weight, more preferably 1 to 10 parts by weight, and most preferably 2 to 4 parts by weight per 100 parts by weight of the inorganic filler. In the present invention, a cationic organic dispersant, an anionic organic dispersant, and a nonionic organic dispersant, and a cationic antistatic agent, an anionic antistatic agent, and a nonionic antistatic agent can be used in any combination. Dispersant to cationic antistatic agent, cationic organic dispersant to anionic antistatic agent, anionic organic dispersant to cationic antistatic agent, anionic organic dispersant to anionic antistatic agent, nonionic organic dispersant to cationic antistatic agent, non- Preferred are ionic organic dispersants to anionic antistatic agents, more preferably cationic organic dispersants to anionic antistatic agents, anionic organic dispersants to anionic antistatic agents, nonionic organic dispersants to anionic antistatic agents, and are most preferred. Are a cationic organic dispersant to an anionic antistatic agent and an anionic organic dispersant to an anionic antistatic agent.

[0016] The antistatic inorganic filler of the present invention includes polyolefins such as polyethylene and polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, and PE.
It can be used as a resin composition by incorporating it into various thermoplastic resins such as polyalkylene terephthalate such as T and polyamide, various rubbers, and thermosetting resins. Of these resins, polyolefins are preferred, and polypropylene is particularly preferred. The form of the resin composition is arbitrary, and may be pellets, sheets, films, strands, yarns, and the like. Further, the resin composition may be formed into a form such as an intermediate member or a final product. The content of the antistatic inorganic filler in the resin composition can be determined according to the purpose.
0% by weight, more preferably 20 to 6% by weight.
0% by weight.

[0017]

According to the antistatic inorganic filler of the present invention, by adding it to a plastic or rubber,
In addition to the effect as a filler such as rigidity, heat resistance, impact resistance, etc., durable and excellent antistatic properties can be imparted. Therefore, when the antistatic inorganic filler of the present invention is used, there is a merit that a charging trouble in a molding process of plastic and rubber and a use application of a final product can be remarkably reduced, which is very useful in practical use, and Resin compositions containing antistatic inorganic fillers can be widely used in injection molded products such as films, sheets, various containers and daily necessities, extruded products such as fishing nets and ropes, and blow molded products such as bottles. Can be. Next, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

[0018]

【Example】

Example 1 A wet pulverized slurry of an inorganic filler was prepared by the following Method 1, Method 2, or Method 3. Method 1 The weight ratio of heavy calcium carbonate having an average particle diameter of 8 μm (a dry-pulverized product of Nippon Cement Limestone raw material) to water was 40/60.
Was added, 0.07 parts by weight of a cationic dispersant was added per 100 parts by weight of heavy calcium carbonate, and using a table-type medium stirring mill, the filling rate of glass beads having a diameter of 1.2 mm of 170 mm and a peripheral speed of 10 m / sec wet grinding, then 35
Classified through a 0 Mesh screen. Method 2 The weight ratio of heavy calcium carbonate having an average particle diameter of 8 μm (a dry-pulverized product of Nippon Cement Limestone raw material) to water was 40/60.
Water, 0.8 parts by weight of nonionic dispersant per 100 parts by weight of heavy calcium carbonate, and using a table-type medium stirring mill, filling rate of glass beads of 1.2 mm in diameter 170%, peripheral speed 10 m / sec wet grinding, then 350
Classified through a Mesh screen.

Method 3 The weight ratio of heavy calcium carbonate having an average particle diameter of 8 μm (a dry-pulverized product of Japan Cement Limestone raw material) to water is 70/30.
Water is added to make 100% heavy calcium carbonate
0.8 parts by weight of an anionic dispersant per part was added, and the mixture was wet-pulverized using a table-type medium stirring mill at a filling rate of glass beads having a diameter of 1.2 mm of 170% at a peripheral speed of 10 m / sec.
Classified through a Mesh screen. An antistatic agent was applied to the wet pulverization thus obtained by the following method A or B to prepare an antistatic calcium carbonate. Method A Wet pulverized slurry is used as a medium fluidizing dryer (Okawara Seisakusho)
Then, 2 parts by weight of an antistatic agent was stirred and mixed with 100 parts by weight of the calcium carbonate powder using a Henschel mixer to obtain antistatic calcium carbonate. Method B 2 parts by weight of an antistatic agent as a solid content was added to 100 parts by weight of the wet-milled slurry solid content, and a tabletop stirring machine (1200 rpm)
And dried with a hot air drier at 120 ° C., and then pulverized using a pulverizer to obtain antistatic calcium carbonate. Table 1 summarizes the organic dispersant and organic antistatic agent used in the above method, and Table 2 shows the obtained antistatic inorganic filler (samples 1 to 12).

[0020]

[Table 1] Table-1 Manufacturer Brand name Chemical name dispersant a San Nopco Co., Ltd. F-2X (cation) Diallylamine-based copolymer b 〃 SN-2X 6300 (non-ionic) Polyhydroxyethyl acrylate-based polymer c 〃 SN-2X 6301 (anion ) special modified polyacrylate Le salts charging d San Nopco (Ltd.) SN-0X 6302 (anionic) 〃 α- olefin sulfonate inhibitor acid sodium e 〃 SN-0X 6303 (anion) alkyl alcohol (EOA) sulphate f SN-0X 6304 (Anion) Alkyl alcohol (EOA) sulfate g 〃 SN-0X 6305 (Anion) Alkyl alcohol (EOA) sulfate h 〃 SN-0X 6306 (Cation) Alkyl trimethyl ammonium salt

[0021]

[Table 2] Table-2 Adjustment of wet pulverized slurry Antistatic CaCO ₃ adjustment sample No. Adjustment method Antistatic agent 1 (dry pulverized product) Untreated Untreated −2 (Dry pulverized product) Untreated Ad 3 Method 1 Untreated −4 {Ad 5} Be 6 Ｂ Bf 7 〃 Bg 8 Ｂ Bh 9 Method 3 Bd 10 〃 Bh 11 Method 2 Bd 12 Ｂ Bh

100 parts by weight of the thus obtained antistatic inorganic filler is mixed with 100 parts by weight of polypropylene (Nippon Polyolefin Co., Ltd. MK411B), and the two rolls are used.
C., Kneading time 10 minutes after kneading, press condition temperature 230 ° C., pressure 150 kgf / cm ² , preheating time 2
Min, heating time 2 min, press, sheet thickness 1mm
Created the sheet. The surface resistance of this sheet was measured using a resistivity chamber manufactured by Advantest Corporation. The results are shown in Table-3.

[0023]

[Table 3] Table-3 (Surface resistance value) 7 days after sample No. 14 days after 1 * 5 × 10 ¹⁵ 2 × 10 ¹³ 4 × 10 ¹³ 2 * 1 × 10 ¹³ 7 × 10 ¹³ 3 × 10 ¹⁴ 3 * 5 × 10 ¹⁶ 9 × 10 ¹⁶ 1 × 10 ¹⁷ 4 3 × 10 ¹¹ ** 9 × 10 ⁹ *** 7 × 10 ⁹ 5 2 × 10 ¹⁰ 5 × 10 ⁹ 5 × 10 ⁸ 6 6 × 10 ¹⁰ 3 × 10 ⁹ 3 × 10 ⁹ 7 2 × 10 ¹³ 8 × 10 ¹⁰ 1 × 10 ¹¹ 8 2 × 10 ¹² 8 × 10 ¹⁰ 2 × 10 ¹⁰ 9 6 × 10 ¹⁰ 7 × 10 ⁹ 1 × 10 ⁹ 10 4 × 10 ¹² 1 × 10 ¹¹ 2 × 10 ¹⁰ 11 4 × 10 ¹⁰ 2 × 10 ⁹ 2 × 10 ⁹ 12 4 × 10 ¹³ 6 × 10 ¹¹ 5 × 10 ¹¹ Samples 1 * to 3 * are comparative examples. ** is the data one day later, and *** is the data eight days later.

Continued on the front page (72) Inventor Yumiko Takase 2-8-6 Nishi-Shimbashi, Minato-ku, Tokyo Sumitomo Realty & Development, Hibiya Building 12th Floor, FIMATECH Co., Ltd. (72) Inventor Ryoji Ito 2-8-, Nishi-Shimbashi, Minato-ku, Tokyo 6 Sumitomo Realty & Development Hibiya Building 12th floor FIMACATE Co., Ltd. (72) Inventor Toshiaki Matsushige 11th Hitotsubashi Honcho, Higashiyama-ku, Kyoto, Kyoto Inside Sannopco Co., Ltd. Address Sannopco Co., Ltd.

Claims (9)

[Claims] 1. An antistatic inorganic filler, wherein an organic dispersant is applied to the surface of the inorganic filler, and an organic antistatic agent is applied on the organic dispersant. 2. The inorganic filler according to claim 1, wherein an organic antistatic agent is applied to the inorganic filler obtained by wet grinding in the presence of an organic dispersant. 3. A resin composition comprising the inorganic filler according to claim 1 or 2. 4. The resin composition according to claim 3, wherein the inorganic filler is calcium carbonate. 5. The method according to claim 1, wherein the organic dispersant has a weight average molecular weight of 1,000 to 1,000.
The resin composition according to claim 4, which is a water-soluble anionic or cationic polymer surfactant having a molecular weight of 150,000. 6. A method for producing an inorganic filler, comprising wet-grinding an inorganic filler in the presence of an organic dispersant, drying and mixing an organic antistatic agent. 7. A method for producing an inorganic filler, comprising wet-grinding an inorganic filler in the presence of an organic dispersant, adding an organic antistatic agent to the obtained ground slurry, and then drying. 8. The method for producing an inorganic filler according to claim 6, wherein the inorganic filler is calcium carbonate. 9. The method according to claim 9, wherein the organic dispersant has a weight average molecular weight of 1,000 to 1,000.
The method for producing an inorganic filler according to claim 8, which is a water-soluble anionic or cationic polymer surfactant having a molecular weight of 150,000.