JPS62158742A - Styrene resin composition - Google Patents

Abstract

PURPOSE:To prevent lowering in antistatic properties by washing while retaining a good antistatic effect under low-humidity conditions, by blending a styrene resin with a specified copolymer and a metal salt capable of forming a solid solution with said copolymer. CONSTITUTION:100pts.wt. styrene resin (a) is blended with 5-100pts.wt. copolymer (b) obtd. by copolymerizing 20-80wt% at least one monomer selected from among vinyl monomers with 20-80wt% at least one monomer selected from among those having 4-500 alkylene oxide groups and copolymerizable unsaturated bonds, 0.2-20pts.wt. metal salt (c) capable of forming a solid solution with said copolymer and 0-20pts.wt. org. solvent (d) for the metal salt. The polyalkylene oxide monomer in the copolymer is effective in allowing the dissolved metal salt to be ionically dissociated under nonaqueous conditions and hence the resin compsn. has a stable antistatic effect even under low- humidity conditions.

Description

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

[Prior Art] Plastics generally have a high electrical resistance and are easily charged with electricity due to friction, etc., attracting dirt and dust, damaging the appearance, and causing malfunctions and breakdowns in electrical and electronic equipment.

In order to reduce the chargeability of such easily charged plastics, it is known to apply or internally knead a WI antistatic agent. Surfactants and silicone compounds are commonly known as antistatic agents for coating.

[Problems to be Solved by the Invention] However, surfactants tend to fall off during washing, and it is difficult to expect long-term antistatic effects.

Although silicon-based compounds can be expected to have a fairly good antistatic effect, they are not only difficult to control coating conditions, but also have poor work efficiency and are disadvantageous in terms of cost.

When an antistatic agent is internally kneaded, the antistatic effect is achieved by the antistatic agent seeping out onto the surface, so the effect is drastically reduced by washing with water or friction, and it takes a long time to recover the antistatic effect.

In addition, in both of the above methods, water in the air is adsorbed onto the surface, increasing the ionic conductivity of the resin surface and exerting an antistatic effect, so the presence of water is essential and low In a humid environment, there are problems such as the antistatic effect becoming weaker.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a resin composition that maintains a good antistatic effect even in a low-humidity environment and whose antistatic properties do not deteriorate when washed. With the goal.

[Means for Solving the Problems] The present invention is based on 100 parts by weight of styrenic resin, and 20 to 80% by weight of one or more monomers selected from vinyl monomers and 4 to 500 alkylenes. 1 selected from monomers with oxide groups and copolymerizable unsaturated bonds
5 to 100 parts by weight of a copolymer obtained by copolymerizing 20 to 80% by weight of at least one monomer, 0.2 to 20'1 tfli part of a metal salt dissolved in the copolymer, and 1 tfli part of a metal salt. The present invention relates to a styrenic resin composition containing 0 to 20 parts by weight of an organic solvent.

[Function] In the styrenic resin composition of the present invention, the metal salt is solidly dissolved in the styrenic resin composition and ionically dissociated,
When an electric field is applied, these ions move through the resin composition and try to neutralize the electric field, thereby exhibiting an antistatic effect. The polyalkylene oxide single omega substance in the copolymer has the effect of ionically dissociating the solid-dissolved metal salt in a non-aqueous environment, and therefore the resin composition has a stable antistatic effect even under low humidity without being affected by moisture absorption. shows. Furthermore, in order to blend the metal salt more uniformly, an organic solvent that dissolves the metal salt may be mixed. If the metal salt is uniformly blended, the antistatic effect will be improved, but since the organic solvent acts as a plasticizer, the heat distortion temperature of the resin composition will be slightly lowered.

One or more types of vinyl monomers in the copolymer are selected so that the copolymer has compatibility with the styrene resin. Therefore, the copolymer is uniformly dispersed in the styrene resin and does not impair the good transparency of the styrenic resin.

[Example] The styrenic resin composition of the present invention contains 1% of 20-8011i and 4-500 of one or more monomers selected from vinyl monomers based on 100 parts by weight of the styrenic resin composition.
5 to 100 parts by weight of a monomer having alkylene oxide groups and a copolymerizable unsaturated bond, and 0.2 to 20 parts of a metal salt dissolved in the copolymer! It is obtained by blending i part by weight and 0 to 20 parts by weight of an organic solvent for the metal salt.

Examples of the styrenic resin used in the present invention include Dialex (manufactured by Mitsubishi Monsanto Kasei), Styron (manufactured by Mitsubishi Monsanto Kasei),
Asahi Dow ■), Idemitsu Styrofoam (Idemitsu Petrochemical ■),
Nisbright (manufactured by Showa Denko), Esterene (Nippon Steel Chemical (TL'FJ), Dix Styrene (Dainippon Ink Chemical (...), Denka Styrol (Denki Kagaku Kogyo)
), styrenic resins such as Toporex (Mitsui Toatsu Chemical ■), Dairyl (Asahi Dow @ J%J), ethylene-As
(Nippon Steel Chemical (manufactured by tI), Sevian-N (manufactured by Daihiru Chemical Industry), Thai Comb (Dainippon Ink Chemical Industry Company)
¥A), Denka As (Denki Kagaku Kogyo (TLJ), Toyorac (manufactured by Toshi ■), Lightac A (Mitsui Toatsu Chemical [1)
Commercially available materials such as styrene-acrylonitrile resins such as Sunrex (manufactured by Mitsubishi Monsanto Kasei Corporation) can be used, but are not limited to these, and other styrenic resins can also be used.

The copolymer used in the present invention contains 20 to 80% by weight of one or more monomers selected from vinyl monomers and 4 to 500% by weight.
One or more monomers selected from monomers having alkylene oxide groups and copolymerizable unsaturated bonds 2
It can be obtained by copolymerizing 1% of 0 to 8%.

The vinyl monomer is selected so that its polymer is compatible with the styrene resin, for example, styrene, α-
Methylstyrene, 0-chlorostyrene, tochlorstyrene, p-brostyrene, m-bromstyrene, p-bromstyrene, p-iodostyrene, p-methoxystyrene, p-dimethylaminostyrene, acrylonitrile, methacrylonitrile, Derivatives of fumaric and maleic acids; vinyl ketones, p-cyanonitrostyrene, p-
Nitrostyrene, esters of acrylic acid and methacrylic acid: One or more monomers such as vinylpyridine, butadiene, etc. can be used, but of course one or more monomers whose polymers are compatible with the styrenic resin can be used. More than one species of monomer can be used.

As the monomer having the alkylene oxide group and having a copolymerizable unsaturated bond, the following general formula +1 is used.
It is preferable to use one or more monomers represented by 1, fl) or (■).

(In the formula, R1 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, X is a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, a phenyl group, 5OsH, 5O2H, PO382,
, R5 and R6 each represent a hydrogen atom or an alkyl group having 1 to 9 carbon atoms, and H represents a hydrogen atom, Li, Na or K.

R2 and R3 represent the same or different hydrogen atoms or alkyl groups having 1 to 4 carbon atoms. m and n are 4≦m+n
Indicates an integer satisfying ≦500. Y is a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a phenyl group, or 2R3, and p and q are integers satisfying 4≦p+Q≦500. ) Y R2R3 (wherein R1, R2, R3, X, Y, m and n are the same as defined in the general formula (11) above)
[Margin below] 1:I R2R3 (wherein, R1, R2, R3, X%Y, m and n
is the same as defined in the general formula (1) above. ) Among the monomers represented by the general formulas (1) to I, those in which at least one of R2 and R3 is a hydrogen atom and which have four or more ethylene oxide groups are particularly preferred because of their large ionic dissociation ability. Of course, similar monomers other than the monomers represented by the general formula [11~() having copolymerizable unsaturated bonds and polyalkylene oxide groups and having ionic dissociation ability in a non-aqueous system can also be used. .

If the number of alkylene oxide groups in the monomer having an alkylene oxide group and a copolymerizable unsaturated bond is less than 4, the ionic dissociation ability becomes small and the antistatic property is reduced. It is difficult to give 500
If the number is more than 1, the transparency of the resin composition is likely to be impaired, so 4 to 500 pieces are required, but especially when the number is 9 to 50 pieces, it has both excellent ion dissociation ability and transparency. Therefore, it is preferable.

The monomer having the alkylene oxide group and having a copolymerizable unsaturated bond can be obtained, and the copolymer may contain 20 to
It is preferable that the content is 80% by weight. If the content is less than 20% by weight, the ion dissociation ability is too small, and if it exceeds 80% by weight, the compatibility with the styrene resin will be lost and the transparency of the resin composition will be impaired, which is not preferable.

The copolymer thus obtained has a blending ratio of 5 parts to 100 parts of the acrylic resin to 100 parts of the acrylic resin.
A range of fl ffi parts is preferred. If the copolymer has less than 5 parts, the improvement in conductivity due to ionic dissociation is small;
Moreover, if it exceeds 100 pockets, the good mechanical properties of the styrene resin will be impaired.

Further, the metal salt dissolved in the copolymer is a component for imparting conductivity to the resin and preventing charging, such as lithium perchlorate, sodium perchlorate, potassium perchlorate, cesium perchlorate. , lithium thiocyanate, sodium thiocyanate, potassium thiocyanate, cesium thiocyanate, lithium borofluoride, sodium borofluoride, potassium borofluoride, lithium bromide, lithium iodide, sodium iodide, potassium iodide, lithium hexafluorophosphate , sodium hexafluorophosphate,
Potassium hexafluorophosphate, lithium trifluoroacetate, sodium trifluoroacetate, potassium trifluoroacetate, lithium trifluoromethanesulfonate, sodium trifluoromethanesulfonate, potassium trifluoromethanesulfonate, lithium tetraphenylborate, sodium tetraphenylborate , potassium tetraphenylborate, and the like can be used alone or in combination of two or more.

The metal salt dissolved in the copolymer is 100% of the acrylic resin.
If it is less than 0.1 parts by weight, there will be little improvement in conductivity and the antistatic effect will be small, and if it exceeds 20 parts by weight, crystals will tend to precipitate, impairing the transparency of the resin composition. Since it becomes brittle, it is preferable to mix it in a range of 0.1 to 20 parts by weight.

Examples of the organic solvent for the metal salt include triethylene glycol, glymes such as dimethyl ether and tetraethylene glycol dimethyl ether, polyethylene glycol, polypropylene glycol, propylene carbonate, ethylene carbonate, dimethylformamide, diethylformamide, dimethylacetamide, N-
Methylpyrrolidone, tetramethylurea, hexamethylphosphoramide, dimethylsulfoxide, acetonitrile, sulfolane, etc. are used, and these may be used alone or two or more types may be used in combination. If the blending ratio of the organic solvent exceeds 20 parts by weight per 100 parts by weight of the acrylic resin, the heat distortion temperature of the resin composition will decrease, and its value as an ordinary plastic material will decrease, which is not preferable.

Although the acrylic resin composition of the present invention thus obtained has excellent antistatic properties and transparency, it cannot be processed by ordinary molding methods such as injection molding, extrusion molding, compression molding, or vacuum forming. Can be used.

Next, the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples.

Example 1 In a 1 g glass flask equipped with a stirring blade, 60 parts of methicine, 401 parts of methoxypolyethylene glycol methacrylate having an average number of ethylene oxide groups of about 23, 1 part of 100 Lff of toluene as a polymerization solvent, α, α
A solution consisting of 2 parts of '-azoisobisbutyronitrile was charged and stirred at 62°C for 5 hours. Thereafter, toluene was removed and the copolymer was obtained by vacuum drying at 80'C for 16 hours.

30 parts by weight of lithium perchlorate was added to 1/100 parts of the copolymer obtained above, and kneaded for 5 minutes at 100°C using a kneader.

Next, 1 part of styrene resin (Dialex 1IF77, manufactured by Mitsubishi Monsanto Kasei ■) was heated to 25 parts by weight of the above-obtained kneaded product to 200°C, kneaded using a kneader, and heated to 200°C, 40011F/ci. A test piece with a thickness of 1.5 m was prepared by press molding. The antistatic property of this test piece was evaluated by measuring the half-life of the charging voltage using a static honest meter (manufactured by Soybean Shokai). The results are shown in Table 1. Note that the measurement conditions are as follows.

Applied voltage 10000V Application time: 1 minute Table rotation speed: 1300 rpm Measurement temperature 25℃ Measurement humidity: 40-55%RH Next, the transparency of the test piece was evaluated by light transmittance.

The measurement method was carried out according to the method of SI801003. The results are shown in Table 1.

Example 2 A test piece was prepared in the same manner as in Example 1 except that sodium perchlorate was used instead of lithium perchlorate as the metal salt, and antistatic property and transparency were evaluated in the same manner as in Example 1. did. The results are shown in Table 1.

Example 3 A test piece was prepared in the same manner as in Example 1, except that sodium thiocyanate was used instead of lithium perchlorate as the metal salt, and antistatic property and transparency were evaluated in the same manner as in Example 1. . The results are shown in Table 1.

Example 4 A test piece was prepared in the same manner as in Example 1 except that potassium thiocyanate was used instead of lithium perchlorate as the metal salt, and the antistatic property and transparency of the test piece were determined in the same manner as in Example 1. was evaluated. The results are shown in Table 1.

Example 5 Same as Example 1 except that methoxypolyethylene glycol methacrylate having an average number of ethylene oxide groups of about 9 was used instead of methoxypolyethylene glycol methacrylate having an average number of ethylene oxide groups of about 23. A copolymer was prepared in the same manner, a test piece was prepared in the same manner as in Example 1, and the antistatic property and transparency were evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 A test piece was prepared in the same manner as in Example 1 using only styrene resin (Dialex 11F77, manufactured by Mitsubishi Monsanto Kasei@), and the antistatic property and transparency were evaluated. The results are shown in Table 1.

Comparative Example 2 25 parts of copolymer manufactured by UA in the same manner as in Example 1 and styrene resin (manufactured by Mitsubishi Monsanto Kasei ■, Dialex H)
F77) Test pieces containing no metal salts were prepared by kneading in the same manner as in Example 1, and antistatic properties and transparency were evaluated. The results are shown in Table 1.

Comparative Example 3 100 parts by weight of styrene resin (manufactured by Mitsubishi Monsanto Kasei ■, Dialex IF77) and 2 parts of lithium perchlorate
A test piece was prepared by adding only the opening part and kneading it in the same manner as in Example 1, and the antistatic property and transparency were evaluated. The results are shown in Table 1.

Table 1 Example 6 Same as Example 1 except that the blending ratio of styrene was 40 folds and the blending ratio of methoxypolyethylene glycol methacrylate having an average number of ethylene oxide groups of about 23 was 60 folds. After preparing the copolymer, a test piece was prepared, and then antistatic properties and transparency were evaluated in the same manner as in Example 1. The results are shown in Table 2.

Example 7 A copolymer was produced in the same manner as in Example 1, except that the blending ratio of styrene was 70 parts by weight, and the blending ratio of methoxypolyethylene glycol methacrylate, which has an average number of ethylene oxide groups of about 23, was 30 parts by weight. After preparing the sample, a test piece was prepared, and then antistatic property and transparency were evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 4 Same as Example 1 except that the blending ratio of styrene was 10 parts by weight and the blending ratio of methoxypolyethylene glycol methacrylate having an average number of ethylene oxide groups of about 23 was 90 parts by weight. After preparing the copolymer, a test piece was prepared, and then antistatic properties and transparency were evaluated in the same manner as in Example 1.

The results are shown in Table 2.

Comparative Example 5 A copolymer was produced in the same manner as in Example 1, except that the blending ratio of styrene was 90 parts by weight and the blending ratio of methoxypolyethylene glycol methacrylate having an average number of ethylene oxide groups of about 23 was 10 parts by weight. After preparing the sample, a test piece was prepared, and then antistatic property and transparency were evaluated in the same manner as in Example 1. The results are shown in Table 2.

Table 2 Example 8 A copolymer was prepared in the same manner as in Example 1, and then a solution was prepared by dissolving 30 parts of lithium perchlorate in 100 parts of tetraethylene glycol dimethyl ether.

A test piece was prepared by kneading 5 parts by weight of the solution obtained from Copolymer 3 (l ffi parts) into 100 parts by weight of styrene resin (Dialex HF77, manufactured by Mitsubishi Monsanto Kasei Co., Ltd.) in the same manner as in Example 1. The antistatic properties and transparency of the obtained test pieces were evaluated.

The results are shown in Table 3.

Example 9 A copolymer was prepared in the same manner as in Example 1, and then 35 parts by weight of lithium perchlorate was added to 10 parts by weight of propylene carbonate.
A solution was prepared by dissolving the solution under 0-weight suspension. This copolymer 30
Add 3 parts by weight of the obtained solution to styrene resin (Dialex 1IF77, manufactured by Mitsubishi Monsanto Chemicals) 1
A test piece was prepared by kneading the 00 layer top portion in the same manner as in Example 1. The antistatic properties and transparency of the obtained test pieces were evaluated. The results are shown in Table 3.

Example 10 A copolymer was prepared in the same manner as in Example 1, and then a solution was prepared by dissolving 301 parts of lithium perchlorate in 100 parts by weight of sulfolane. 30 parts by weight of this copolymer and 5 parts by weight of the obtained solution were added to styrene resin (Mitsubishi Monsanto Chemical Co., Ltd.).
Example 1 to 100 parts by weight of Dialex HF77
A test piece was prepared by kneading in the same manner as above. The antistatic properties and transparency of the obtained test pieces were evaluated. The results are shown in Table 3.

Example 11 The composition of the copolymer was 40 parts by weight of styrene, 20 parts by weight of α-methylstyrene, 40 parts of methoxypolyethylene glycol methacrylate having an average number of ethylene oxide groups of about 23, and 100 parts of l-luene. , α, α
'-Azoisobisbutysilonitrile 21 A copolymer was prepared as a hanging part in the same manner as in Example 1, and a test piece was produced. Next, antistatic properties and transparency were evaluated in the same manner as in Example 1. The results are shown in Table 3.

As can be seen from the results in Table 3 and above, the styrene resin composition of the present invention has a charging voltage half time of 1.2 seconds or less, and a light transmittance of 82% or more. It turns out that it is very good.

[Results of the Invention] The styrenic resin composition of the present invention has the function of solidly dissolving metal salts to dissociate ions, prevents charging by ion conduction in a non-aqueous system, and can be used in low-humidity environments. It exhibits excellent antistatic properties even when used indoors, and its antistatic properties do not deteriorate even after washing, making it suitable for electronic and electrical equipment parts, building materials, interior goods, etc. used in such environments. It can be used suitably.

Furthermore, since the styrene resin composition of the present invention has excellent light transmittance, it can be used, for example, in indicator covers, IC storage containers, cathode ray tube front covers, three lighting fixture covers, escalator side panels, electronic component packaging trays, etc. , OA equipment covers, audio equipment covers, etc.

Procedural amendment (voluntary) 3. Relationship with the case of the person making the amendment Patent applicant address 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (601) Moriya Shiki 4, representative of Mitsubishi Electric Corporation, agent Address: 2-2-3 Marunouchi, Chiyoda-ku, Tokyo, Form 5, Subject of amendment (1) Column 6 of “Detailed Description of the Invention” of the specification, Contents of amendment (1) Line 1 of page 9 of the specification: CH22C-C-0-R2CH2O, X-(OCHCHz)m-(OCHC)12)n 0
82 R3J is corrected as R2R3J.

(Correct "triethylene glycol, dimethyl ether" on page 12, lines 6-7 to "triethylene glycol dimethyl ether".

(3) "α,α゛-Azoisobisbutyronitrile on page 21, line 8 is corrected to ``α,α゛-Azoisobisbutyronitrile.

that's all

Claims (1)

[Claims] (1) Contains 4 to 500 alkylene oxide groups and is copolymerizable with 20 to 80 weight % of one or more monomers selected from vinyl monomers based on 100 parts by weight of styrene resin. 5 to 100 parts by weight of a copolymer obtained by copolymerizing 20 to 80% by weight of one or more monomers having unsaturated bonds, and a metal dissolved in the copolymer. A styrenic resin composition containing 0.2 to 20 parts by weight of a salt and 0 to 20 parts by weight of an organic solvent for a metal salt.