JPH0735458B2 - Acrylic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an antistatic acrylic resin composition.

[Problems to be Solved by Prior Art and Invention]

Acrylic resins are widely used as molding materials having excellent transparency and good mechanical properties. While this resin has excellent electrical insulation properties, static electricity is easily charged and accumulated, which is a cause of remarkably reduced commercial value such as deterioration of transparency and aesthetic appeal.

In order to solve this problem, it has been proposed to knead a glycerin fatty acid ester into an acrylic resin, but this method requires kneading a large amount of a glycerin fatty acid ester, resulting in a decrease in heat resistance of the resin. There is a drawback that. Therefore, it has been proposed to use glycerin fatty acid ester in combination with a surfactant to reduce the amount of glycerin fatty acid ester added. However, when the alkyl sulphate quaternary salt is used as the surfactant, the heat resistance is still insufficient, and when the phosphite ester is used, there is a tendency to accelerate thermal coloring and deteriorate transparency. When sulfosuccinate or sulfoacetate is used, there are problems such as bleeding and stickiness of the resin composition, and none of them is in a sufficient state.

[Means for Solving the Problems]

The inventors of the present invention have completed the present invention as a result of studying a kneading type antistatic agent having sufficient antistatic properties without impairing the transparency and heat resistance of the acrylic resin.

That is, in the present invention, 100 parts by weight of an acrylic resin is mixed with 0.2 to 5 parts by weight of the following components (A) and (B) so that the weight ratio is 20/80 to 80/20. An acrylic resin composition obtained by kneading is provided.

(A) component: RSO ₃ X or (R represents an alkyl group having 8 to 22 carbon atoms and X represents an alkali metal.) Component (B): glycerin fatty acid ester (The fatty acid has 12 to 22 carbon atoms and the monoglyceride content is 70% by weight or more. ) Sodium and potassium salts are preferable as the sulfonic acid alkali metal salt of the component (A) used in the present invention.

According to the present invention, the ratio of the component (A) and the component (B) is a weight ratio.
20/80 to 80/20. If the amount of component (A) exceeds this range, the transparency of the acrylic resin is impaired, and if the amount of component (B) exceeds this range, the antistatic effect is insufficient. Is. Component (A) + component (B) is added in an amount of 0.2 to 5 parts by weight per 100 parts by weight of the resin, and if the amount is less than 0.2 parts by weight, the antistatic effect is insufficient. Even if the amount is increased, the antistatic effect is not particularly improved, and side effects such as stickiness on the surface of the molded product are recognized.

The glycerin fatty acid ester as the component (B) is preferably as high as the monoglyceride content is, and if the content is decreased and the diglyceride content is increased, the antistatic effect is deteriorated, so the monoglyceride needs to be 70% by weight or more.

The acrylic resin used in the present invention is not particularly limited, and generally known ones are exemplified, and examples thereof include a homopolymer and a copolymer of an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms. . Examples of the copolymerizable monomer in this case include alkyl acrylates having an alkyl group having 1 to 8 carbon atoms, aromatic vinyl compounds such as styrene and methylstyrene, and vinyl cyanide compounds such as acrylonitrile and methacrylonitrile. Further, JP-A-53-58554 and JP-A-57-14016
No. 1, JP-A-57-147539, U.S. Pat.No. 3793402
U.S. Pat.No. 3,808,180, U.S. Pat.No. 443
An acrylic multistage (multilayer structure) polymer as disclosed in, for example, Japanese Patent No. 3103 is also used.

As the polymerization method of the above-mentioned polymer, a known polymerization method such as a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method or a solution polymerization method is used, and it can be selected according to the composition and purpose of the polymer.

In addition to the above kneading components, the acrylic resin composition of the present invention may further contain various additives such as stabilizers, lubricants, dyes and pigments, and fillers depending on the purpose. In particular, when a decrease in heat resistance (coloring temperature when the molded body is heated) of the acrylic resin composition is observed due to the addition of the kneading component, it is preferable to use a heat stabilizer in combination.

As a method for kneading the additive component into the acrylic resin, a known and ordinary method is adopted. Alternatively, a master pellet method may be used in which a master pellet is prepared by kneading a large amount of additive components and kneaded into a natural pellet.

The acrylic resin composition of the present invention is used for manufacturing a molded product by injection molding, extrusion molding, etc., and for manufacturing a film-shaped product by a T-die method, an inflation method, a calender method and the like.

〔Example〕

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

The parts in the examples are based on weight.

Examples 1 to 3 and Comparative Examples 1 to 9 In 100 parts by weight of bead-shaped methacrylic resin (Acrypet MF manufactured by Mitsubishi Rayon Co., Ltd.), A component: C ₁₂ H ₂₅ —SO ₃ Na B component: stearic acid monoglyceride. (Monoglyceride content 90% by weight) was blended in various proportions, mixed in a Henschel mixer, melt-kneaded in an extruder and pelletized. After melting these pellets in the extruder, 100mm by injection molding method
A test piece of 100 mm x 2 mm was molded. Using this test piece,
Takeda Riken TR-8601 Super Insulation Resistance Tester at 20 ℃, Humidity 70
The surface resistance was measured in% and the appearance was observed.

The results are shown in Table I.

In Examples 1 to 3, excellent antistatic ability was exhibited, and no defect in appearance was observed. In Comparative Examples 1 to 9, in order to exhibit good antistatic ability, it is necessary to blend a large amount of the component A or the component B. When blended in such a large amount, the surface gloss and the transparency are deteriorated. It caused a problem in appearance.

Examples 4 to 8 and Comparative Examples 10 to 12 Based on 100 parts by weight of bead-shaped methacrylic resin (Acrypet V manufactured by Mitsubishi Rayon Co., Ltd.) Were mixed in various proportions, mixed with a Henschel mixer, melt-kneaded with an extruder and pelletized.

After melting the pellets with an extruder, an extrusion plate having a thickness of 3 mm was obtained by an extrusion molding method. This extruded plate was used for evaluation in the same manner as in the previous example. The results are shown in Table II. In Examples 4 to 8, there were no defects in appearance and the antistatic ability was good. In Comparative Examples 10 to 12, when the blending amount was small, the antistatic ability was insufficient, and when the blending amount was too large, the appearance was defective.

Examples 9-12 and Comparative Examples 13-17 The abbreviations used in this example are as follows.

Methyl methacrylate MMA Butyl acrylate BuA Acrymethacrylate AMA 1,3-butylene glycol dimethacrylate BD Cumene hydroperoxide CHP Sodium formaldehyde sulfoxylate SFS 250 parts of ion-exchanged water, sulfosuccinic acid Charge 2 parts of ester soda, 0.05 part of SFS, stir under nitrogen, and after stirring under nitrogen, 1.6 parts of MMA, 8 parts of BuA, 0.4 parts of BD, MAM0.
A mixture consisting of 1 part and 0.04 part CHP was charged. After the temperature was raised to 70 ° C., the reaction was continued for 60 minutes to complete the polymerization of the innermost layer copolymer (A).

Then, a monomer mixture of MMA / BuA / BD / AMA = 1.5 / 22.5 / 1.0 / 0.25 part was added over 60 minutes and polymerized to obtain a two-layer crosslinked rubber elastic body.

In this case, the amount of CHP used to form the polymer (B) was 0.05% with respect to the monomer mixture.

Then, as the intermediate layer (D), 5 parts of MMA, 5 parts of BuA and 0.1 part of AMA.
1 part of the mixture was reacted and finally MMA / BuA = 52.25 / 2.75 parts of the monomer mixture was reacted to form the outermost layer polymer (C).

5 parts by weight of the obtained polymer emulsion per 100 parts of the polymer.
Part of calcium chloride was salted out, washed and dried to obtain a multi-layered polymer containing an alkyl methacrylate.

The multilayer structure A component RSO ₃ Na in the polymer 100 parts of (R is C ₁₂ H ₂₅ - and C ₁₄ H ₂₇ - mixtures) B component monoglyceride stearate (monoglyceride content 70 wt%) in proportions shown in Table III After mixing with a Henschel mixer, the mixture was further melt-kneaded with an extruder and pelletized.

The obtained pellet was formed into a film by using a T die. Evaluation was performed in the same manner as in Examples 1 to 3 using a film having a thickness of 20 μm. The results are shown in Table III.

In Examples 9 to 12, excellent antistatic ability was exhibited, and no defect in appearance was observed.

In Comparative Example 13 the antistatic property is insufficient, Comparative Examples 14-17
However, there were defects in appearance such as lumps and sagging.

Examples 13 to 16 and Comparative Examples 18 to 22 In a mixture of 56 parts of the rubber-containing polymer shown below and 44 parts of the following thermoplastic polymer, A component: C ₁₂ H ₂₅ SO ₃ Na B component: lauric acid monoglyceride ( A monoglyceride content of 75% by weight) was blended in the proportions shown in Table IV to form films in the same manner as in Examples 9-12. Evaluation was performed in the same manner as in Examples 1 to 3 using a film having a thickness of 20 μm. The results obtained are shown in Table IV.

In Examples 13 to 16, excellent antistatic properties were exhibited and no defect in appearance was observed. In Comparative Example 18, the antistatic property was insufficient, and in Comparative Examples 19 to 22, there were problems in the appearance of the film such as the occurrence of spots and sagging.

[Rubber-containing polymer]

Charge the following proportions of the raw materials into the reaction vessel, and under a nitrogen atmosphere: 50
The polymerization was completed while stirring at 4 ° C. for 4 hours to obtain an elastic latex.

Butyl acrylate 77 parts Styrene 22.7 parts Allyl methacrylate 0.3 parts Dioctyl sodium sulfosuccinate 2.0 parts Deionized water 300 parts Potassium peroxide 0.3 parts Disodium phosphate dodecahydrate 0.5 parts Sodium hydrogen phosphate dihydrate 0.3 parts 100 parts of this elastic latex (as a solid material) was placed in a reaction vessel and, while thoroughly stirring and substituting with nitrogen, the temperature was raised to 80 ° C and sodium formaldehyde sulfoxylate was added.
After adding an aqueous solution consisting of 0.125 part and 2 parts of water, the temperature is raised to 80 ° C.
While maintaining at 60%, a mixture of 60 parts of methyl methacrylate, 0.05 parts of n-octyl mercaptan and 0.125 parts of t-butyl hydroperoxide was added dropwise over 2 hours, and then 2
Hold for time to complete the polymerization.

The obtained copolymer latex was added to 3% saline, and after salting out, dehydration, washing with water and drying were performed to obtain a rubber-containing polymer in powder form.

[Thermoplastic polymer]

Methyl methacrylate / methyl acrylate copolymer (methyl methacrylate / methyl acrylate = 98/2, η
_{SP / C} = 0.06 / g) Comparative Examples 23 to 26 Additives shown in Table V were added to 100 parts by weight of bead-shaped methacrylic resin (Acrypet MF manufactured by Mitsubishi Rayon Co., Ltd.),
After mixing with a Henschel mixer, the mixture was melt-kneaded with an extruder and pelletized. After melting the pellets by an extruder, a 100 mm × 100 mm × 2 mm test piece was molded by an injection molding method. Using this test piece, the surface resistance was measured at 20 ° C. and 70% humidity with a TR8601 super insulation resistance meter manufactured by Takeda Riken.
The appearance was also observed.

The results are shown in Table VI.

Note) * 1: Sulfosuccinate I (R represents a 2-ethylhexyl group.) * 2: Sulfoacetate I * 3: Cationic activator I * 4: Sulfonate I As is clear from the above results, Comparative Examples 23 to 26 had insufficient antistatic properties, and Comparative Examples 23 to 25 also had a defect in appearance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 58-125741 (JP, A) JP 59-74150 (JP, A) JP 60-94432 (JP, A) Additives for plastics and rubber Practical Handbook P. 333-337 (October 1, 1972, issued by Shiki Kogyo Co., Ltd.)

Claims (1)

[Claims] 1. A total of 0.2 to 5 parts by weight of 100 parts by weight of an acrylic resin so that the weight ratio of the following components (A) and (B) is 20/80 to 80/20. Acrylic resin composition kneaded (A) component: RSO ₃ X or (R represents an alkyl group having 8 to 22 carbon atoms and X represents an alkali metal.) Component (B): glycerin fatty acid ester (The fatty acid has 12 to 22 carbon atoms and the monoglyceride content is 70% by weight or more. )