JPH0759658B2 - Methacrylic resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a methacrylic resin composition, and more particularly to a methacrylic resin composition having excellent heat resistance, antistatic properties and impact resistance.

[Prior Art] Generally, methacrylic resin is excellent in transparency, weather resistance, surface glossiness, mechanical strength, moldability, etc., and is therefore used in fields such as signboard lighting equipment parts and vehicle exterior parts. . However, its heat resistance is not sufficient, and its use is limited in applications that require stability at high temperatures. For this reason, methacrylic resin with higher heat resistance,
Is requested.

Heretofore, a method for producing a copolymer composed of an aromatic vinyl monomer, maleic anhydride and other vinyl monomers has been known (see, for example, Japanese Patent Publication Nos. 45-31953 and 49-10156).

The copolymer using maleic anhydride as a monomer has high heat resistance. However, in the copolymer,
When maleic anhydride monomer is present, at high temperature,
It causes chemical changes and decomposes. Therefore, such a copolymer is significantly restricted by molding conditions during injection molding or extrusion molding. Moreover, defective appearance such as silver streaks due to thermal decomposition occurs, and the defective rate of the product increases. Further, when the product is brought into contact with water or steam or exposed to a high temperature, there is a drawback that it causes whitening of the product.

Further, there are problems inherent in the methacrylic resin, such as cracking due to lack of impact resistance, and dust adhesion due to electrostatic damage.

[Problems to be Solved by the Invention] The present invention is to find a methacrylic resin composition having excellent heat resistance, antistatic property and impact resistance without impairing the original properties of the methacrylic resin.

[Means for Solving Problems] The methacrylic resin composition of the present invention is a copolymer containing [I] 40% by weight or more of methyl methacrylate unit and maleic anhydride unit and / or N-substituted maleimide unit. A methacrylic resin having a heat distortion temperature of 105 ° C. or higher of 50 to 99.8% by weight, [II] the following formulas (A), (B), (C), (D), (E),
(F), (G) and (H) (In these formulas, R, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ and R
_{9's, which} may be the same or different, each represents hydrogen or an acyl group having 8 to 20 carbon atoms; R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and
R _{15 s} may be the same as or different from each other and have 1 carbon atom.
Represents ~ 18 alkyl _{group; R 16, R 17, R} 18 and R _19, which may be said even identical to each other, represents an alkyl group having 8 to 20 carbon atoms; M, M _1, M ₂ , M ₃ and M ₄ , which may be the same or different from each other, represent a hydrogen atom, a sodium atom, a potassium atom and a lithium atom; and n represents a number of 1 to 50. 10 to 0.2 wt% of at least one compound selected from the group of compounds represented by the formula (1), and [III] 1,3-butadiene and / or a rubber component containing 50 wt% or more of acrylic acid ester units, substituted with methyl methacrylate, Alternatively, it is composed of 0 to 49.8% by weight of a graft copolymer obtained by graft-polymerizing at least one vinylic monomer selected from unsubstituted styrene and acrylonitrile, and the total of each component of [I] to [III]. The amount is 100% by weight.

Hereinafter, the present invention will be described in detail.

Methacrylic resin composition of the present invention (hereinafter, simply "composition"
The methacrylic resin, which is a constituent element of), must have high heat resistance. Specifically, the heat distortion temperature (HDT) specified by ASTM D-648 needs to be 105 ° C or higher. General methacrylic resin has an HDT of 80 to 100
℃, and as the constituent element [II], the formula (A)
When at least one of the compounds represented by (H) to (H) is blended, HDT is significantly reduced, and satisfactory heat resistance cannot be obtained.

Therefore, the methacrylic resin satisfying this condition needs to be a polymer containing 40% by weight or more of methyl methacrylate unit, and the constituent unit that can be contained is the heat resistance or antistatic property of the obtained composition. It is not particularly limited as long as it does not impair the property, but in the present invention, those having a maleic anhydride unit and / or an N-substituted maleimide unit are preferable.

In addition, if necessary within the range that does not impair the object of the present invention,
Constitutional units other than the above may be contained. For example,
For the purpose of improving the fluidity of the methacrylic resin, a small amount of an alkyl acrylate unit or an aromatic vinyl compound unit may be contained.

More preferable examples of the methacrylic resin [I] which is one component of the present invention include the following.

(1) Methyl methacrylate unit 40 to 90% by weight, maleic anhydride unit 5 to 20% by weight, α-methylstyrene unit 0
A copolymer consisting of -20% by weight and 5-20% by weight of styrene units.

In this case, it is particularly preferable that the molar ratio of α-methylstyrene and styrene to maleic anhydride is 0.8 to 1.5.

(2) A copolymer comprising 40 to 96% by weight of a methyl methacrylate unit, 4 to 35% by weight of an N-substituted maleimide unit, and 0 to 25% by weight of an aromatic vinyl compound unit.

The N-substituted maleimide used here includes maleimide, N-alkylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, N-arylmaleimide and substituted derivatives thereof, and more specifically, N-
Methyl maleimide, N-ethyl maleimide, N-n-butyl maleimide, Nt-butyl maleimide, N-cyclohexyl maleimide, N-phenyl maleimide, N-
(2-chlorophenyl) maleimide, N- (4-chlorophenyl) maleimide, N- (4-bromophenyl) maleimide, N- (2-methylphenyl) maleimide, N
-(2-t-butylphenyl) maleimide, N- (4-
t-Butylphenyl) maleimide, N- (2-nitrophenyl) maleimide, N- (2-methoxyphenyl) maleimide, N- (2,4,6-trimethylphenyl) maleimide, N- (4-benzylphenyl) maleimide Etc. can be mentioned.

As the copolymer, one having a lower water absorption rate is suitable for use in a high temperature and high humidity state. Therefore, among the above N-substituted maleimides, Nt-butylmaleimide, N-cyclohexylmaleimide and N-aryl are preferable. Maleimides and their halogen- and / or alkyl-substituted derivatives are preferred.

The aromatic vinyl compound used here includes styrene, o-, m- and / or p-methylstyrene, 1,3
-Dimethylstyrene, 2,4-dimethylstyrene, pt
-Vinylstyrene, α-methylstyrene, α-ethylstyrene and α-methyl-p-methylstyrene, etc., monovinylidene aromatic hydrocarbons, o-, m- and / or p-chlorostyrene, 2,4-dibromostyrene And an alhamonovinylidene aromatic hydrocarbon such as 2-methyl-4-chlorostyrene. The molar ratio of the aromatic vinyl compound to the N-substituted maleimide is in the range of not more than 5 times, preferably not more than 2 times.

The method for producing the methacrylic resin is not particularly limited, and the methacrylic resin can be polymerized by a commonly used polymerization method.
In the case of (1), bulk polymerization is preferable, and in the case of (2), suspension polymerization is preferable.

The mixing ratio of the methacrylic resin [I] is 50 to 99.8% by weight based on 100% by weight of the total amount of [I] to [III]. If the blending ratio is less than 50% by weight, the heat resistance will be significantly reduced. If it exceeds 99.8% by weight, the antistatic effect cannot be obtained. The compound [II] has the following formulas (A), (B), (C), (D),
(E), (F), (G) and (H): (In these formulas, R, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ and R
_{9's, which} may be the same or different, each represents hydrogen or an acyl group having 8 to 20 carbon atoms; R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and
R _{15 s} may be the same as or different from each other and have 1 carbon atom.
Represents an alkyl group having from 18 to 18; R ₁₆ , R ₁₇ , R ₁₈ and R _{19, which} may be the same or different, each represents an alkyl group having 8 to 20 carbon atoms; M, M ₁ , M ₂ , M ₃ and M ₄ may be the same or different from each other and represent a hydrogen atom, a sodium atom, a potassium atom and a lithium atom; and n represents a number of 1 to 50. ) It is at least one compound selected from the group of compounds represented by: Even if a substance other than the above is used, it is difficult to maintain the original properties of the resin.

The compounding ratio of the compound [II] is such that the total amount of [I] to [III] is 100.
10 to 0.2% by weight, more preferably 7 to 0.2% by weight
It is 0.3% by weight. Outside this range, the surface of the final product of the resin composition becomes tacky, or there arises a defect that the antistatic effect is not exhibited.

Graft copolymer which is one of the constituent elements of the present invention [III]
Is a graft copolymer composed of a rubber component containing 50% by weight or more of 1,3-butadiene and / or acrylic acid ester units.

The acrylic acid ester used here is an ester of acrylic acid and an alcohol having 1 to 8 carbon atoms. Among them, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate and benzyl acrylate are preferable.

Examples of the monomer that can be used as a rubber component other than 1,3-butadiene and acrylic acid ester include alkyl methacrylate, cyclohexyl methacrylate, styrene, and acrylonitrile.

As the rubber component, those having a crosslinked structure are preferable from the viewpoint of improving impact resistance. For this reason, it is necessary to copolymerize using a suitable crosslinking agent. In this case, the cross-linking agent is ethylene glycol dimethacrylate, 1,3
Examples thereof include butadiene glycol dimethacrylate, 1,4-butanediol diacrylate, allyl acrylate, allyl methacrylate, diallyl phthalate, triallyl cyanate, triallyl isocyanate and divinylbenzene.

A graft copolymer can be obtained by copolymerizing these rubber components with other monomers. In this case, the monomer is at least one vinyl monomer selected from methyl methacrylate, substituted or unsubstituted styrene and acrylonitrile.

Graft polymerization may be one-step polymerization, but each step polymerization is preferred. In this case, it is necessary to include the aforementioned rubber component in one layer formed by polymerization.

Graft copolymer [III] is one having a hard resin inside the elastomer, one having a multilayer elastomer portion, or one having a hard resin layer made of multiple layers in the graft portion, as long as it exhibits elastomeric properties. May be The glass transition temperature (Tg) of the elastomer in this case is preferably room temperature or lower. Tg
Is less than ordinary temperature, the compound (II) in the composition can easily move, and thereby the dispersion state of the compound (II) in the composition becomes good and the antistatic property is improved. is there.

Preferred examples of the graft copolymer [III] will be listed below.

The graft copolymer [III] of the first example is obtained by two-step polymerization. This graft polymer [II
I] is an elastomer layer having (i) an acrylic ester obtained by the first-stage polymerization as a main constituent unit and having Tg of 25 ° C. or lower; and (ii) in the presence of the product obtained by the first-stage polymerization. In addition, it comprises a hard resin layer having a main structural unit of methyl methacrylate obtained by the second stage polymerization and having a Tg of 25 ° C. or higher. The graft copolymer [III] shown in this first example is described in, for example, Japanese Patent Publication No. 54-18298.

The graft copolymer [III] of the second example is a multi-stage sequential polymer obtained by three-stage or more stage polymerization. This graft copolymer has (i) an acrylic ester as a main constituent unit, an elastomer layer obtained by the first-stage polymerization at a Tg of 25 ° C. or lower, and (ii) a methyl methacrylate as a main constituent unit, and a Tg of 25. (Iii) one or more intermediate layers obtained by one or more intermediate polymerization steps between the hard resin layer obtained by the final polymerization step of ℃ or higher It has methyl as a main constituent unit and has a Tg between the first-stage elastomer layer and the last-stage hard resin layer.

The graft copolymer [III] of the third example is a multi-step sequential polymer obtained by three-step polymerization. This graft copolymer has (i) an acrylic acid ester as a main constituent unit, an elastomer layer obtained by the first-stage polymerization with Tg of 25 ° C. or lower, and (ii) the presence of the product obtained by the first-stage polymerization. In the presence of a hard resin layer having Tg of 25 ° C. or higher as a main constituent unit obtained by the second-stage polymerization below and (iii) the product obtained by the second-stage polymerization, It comprises an acrylic acid ester obtained by three-stage polymerization as a main constituent unit and an elastomer layer having Tg of 25 ° C. or lower.

The graft copolymer [III] of the fourth example is a multi-step sequential polymer obtained by four-step polymerization, and has (i) an acrylic ester obtained by the first-step polymerization as a main constituent unit and a Tg of 25 ° C. An elastomeric layer that is (ii) first
In the presence of the product obtained by the step polymerization, the main structural unit is methyl methacrylate obtained by the second step polymerization, and the Tg is
A hard resin layer having a temperature of 25 ° C or higher, (iii) an elastomer whose main constituent unit is an acrylate ester obtained by the third step polymerization in the presence of the product obtained in the second step polymerization, and Tg of 25 ° C or lower Layer and (iv) a hard resin layer having a main structural unit of methyl methacrylate obtained by the fourth step polymerization in the presence of the product obtained by the third step polymerization and having a Tg of 25 ° C. or higher. It is a thing.

An example of the graft copolymer [III] of the fifth example is 3
It is a multistage sequential polymer obtained by stepwise polymerization. This polymer comprises (i) a hard resin layer obtained by the first-stage polymerization, which has methyl methacrylate as a main constituent unit and Tg of 25 ° C. or higher, and (ii) a product obtained by the first-stage polymerization. In the presence of an acrylic acid ester obtained by the second-stage polymerization in the presence of an elastomer layer having a Tg of 25 ° C. or lower, and (iii) the product obtained by the second-stage polymerization, The main constituent unit is methyl methacrylate obtained by stepwise polymerization, and the hard resin layer has Tg of 25 ° C. or higher. Examples of this graft copolymer are described, for example, in US Pat. No. 4,433,103.

The graft copolymer [III] of the sixth example is a multi-stage sequentially produced polymer obtained by polymerization of 5 or more stages, and has (i) methyl methacrylate as a main constituent unit and a Tg of 25. A hard resin layer obtained by the first-stage polymerization at a temperature of ℃ or higher, (ii) an elastomer layer formed by an intermediate polymerization step, having an acrylic ester as a main constituent unit and Tg of 25 ℃ or lower, and (iii) methacryl Methyl acid as the main constitutional unit, Tg is 25 ℃ or more, acrylic acid ester and methyl methacrylate as the main constitutional unit between the respective layers of the hard resin layer obtained in the final polymerization stage, and Tg is It is a graft copolymer having an intermediate layer between the Tg of the obtained layer and the Tg of the layer obtained by the subsequent polymerization.
This graft copolymer is disclosed, for example, in U.S. Pat. No. 4,054,525.
No.

An example of the graft copolymer [III] of the seventh example is a multi-step sequential polymer obtained by four-step polymerization, in which (i) methyl methacrylate is the main constituent unit and Tg is 25 ° C. or higher. A hard resin layer obtained by one-step polymerization, (ii)
In the presence of the product obtained by the first stage polymerization, a second
Acrylic ester obtained by stepwise polymerization as a main constituent unit, elastomer layer having Tg of 25 ° C. or lower, (iii) third step polymerization in the presence of the product obtained by second step polymerization Acrylic acid obtained by the fourth stage polymerization in the presence of a hard resin layer having a methyl methacrylate as a main constituent unit and a Tg of 25 ° C. or higher and (iv) a product obtained by the third stage polymerization. Ester as main constituent unit, Tg of 25
And an elastomer layer having a temperature of ℃ or less. This graft copolymer can be obtained, for example, from JP-A-59-124947 and JP-A-59-1249.
No. 48 is mentioned.

The graft copolymer [III] of the eighth example comprises 1 to 95% by weight of 1,3-butadiene, 99 to 5% by weight of alkyl acrylate and a monofunctional and / or polyfunctional copolymerizable copolymer. Obtained by graft-polymerizing 10 to 1000% by weight of a monomer containing methyl methacrylate as a main component in the presence of 100% by weight of an elastomer obtained by polymerizing 0 to 20% by weight of a monomer. Is.

The content of the graft copolymer [III] in the composition is 0 to 4
It is 9.8% by weight. In the present invention, the graft copolymer [III] may not be blended, but from the viewpoint of the synergistic effect of impact resistance and antistatic property, it is preferably blended in an amount of 0.5% by weight or more. The preferred range is 0.5 to 45% by weight. Four
If it exceeds 9.8% by weight, the heat resistance will decrease.

The method for producing the graft copolymer is not particularly limited,
The emulsion polymerization method is preferred. Hereinafter, an example of preparing the graft copolymer [III] by the emulsion polymerization method will be described.

After adding deionized water and an emulsifier to a reaction vessel, a predetermined amount of a vinyl-based monomer is added to a rubber latex composed of 1,3-butadiene and / or an acrylate ester to carry out graft polymerization.

The polymerization temperature is 30 to 120 ° C, more preferably 50 to 100 ° C. The polymerization time varies depending on the type and amount of the polymerization initiator and the emulsifier, the number of polymerization steps, the polymerization temperature, etc., but usually 0.5 to 2
It's 0 hours.

The mixing weight ratio of the monomer and water is preferably monomer / water = 1/20 to 1/1.

The polymerization initiator and the emulsifier can be added to either or both of the water phase and the monomer phase.

The method of charging the monomers in the polymerization operation can be carried out all at once or in a divided manner, but basically the divided charging method is preferable although the number of polymerization steps is slightly different.

The emulsifier is not particularly limited as long as it is usually used, examples of use, long-chain alkyl carboxylate,
Examples thereof include sulfosuccinic acid alkyl ester salts and alkylbenzene sulfonates.

The type of polymerization initiator is not particularly limited, and a commonly used inorganic initiator such as water-soluble persulfate or perborate can be used alone or in combination with sulfite as a redox initiator. . Further, redox initiator type initiators such as organic hydroperoxide-sodium formaldehyde sulfoxylate, benzoyl peroxide type initiators, and azobisisobutyronitrile type initiators can also be used.

After completion of the polymerization, by coagulating and drying by a conventional method,
Graft copolymer [III] can be obtained.

By blending the graft copolymer [III] thus obtained, the mechanical properties, particularly the impact resistance, can be improved without substantially lowering the heat resistance of the composition. Further, the compounding amount of the compound [II] can be reduced without lowering the antistatic effect.
Further, the moldability can be improved.

By blending the methacrylic resin [I] and the compound [II] described above, a composition excellent in heat resistance and antistatic property can be obtained by their synergistic action, and further, a graft copolymer By compounding the coalescence, the composition of the present invention having excellent impact resistance can be obtained.

As a blending method of each component, a method of melt mixing is generally used. Specifically, before melting and mixing, if necessary, stabilizers, lubricants, plasticizers, dyes, pigments, fillers, etc. are added, and a V-type blender, a Henschel mixer, a mixing roll, and a screw type extruder are used. Melt kneading at 150-300 ° C. The composition thus obtained can be molded by an extruder or an injection molding machine to obtain a molded article having excellent impact resistance and excellent antistatic properties.

When the composition of the present invention is molded into a sheet, the compound [II] and the graft copolymer [III] are dissolved in the monomer mixture at the stage of polymerizing the methacrylic resin. Then, this solution is poured into two opposing tempered glass plates or a cell formed of stainless steel or the like through a gasket, and cured to obtain a sheet-shaped composition.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the examples and comparative examples, all "parts" are "parts by weight".
And "%" all represent "% by weight".

[Examples of the Invention] The methacrylic resin [I] and the graft copolymer [III], which are the constituent elements of the present invention, were prepared as follows.

(1) Preparation of methacrylic resin [I] [I] -1 14 kg of methyl methacrylate, 10 kg of α-methylstyrene, 25 kg of styrene, 25 kg of maleic anhydride and 60 g of t-dodecyl mercaptan were placed on a cooling pipe, a thermometer and a stirring device. Charge the SUS-made reaction vessel provided and heat while stirring.
Add 20 g of azobisisobutyronitrile at an internal temperature of 75 ° C,
After keeping the internal temperature at 95 ° C for 15 minutes, it was cooled to obtain a syrup-like partial polymer.

To 10 kg of this partial polymer, as a polymerization initiator, bis (3, 5,
5-Trimethylhexanoyl) peroxide 300 g, JP-504 (manufactured by Johoku Chemical Co., Ltd.) as a release agent were added and dissolved, and then two sheets of tempered glass opposed to each other at a 6 mm interval through a polyvinyl chloride gasket The composition was poured into several sets of cells formed of plates and immersed in warm water at 80 ° C to polymerize and cure. Then, it was treated in an air heating furnace at 130 ° C. for 2 hours. After cooling, the cell was removed, and a resin plate having a plate thickness of about 6 mm was cut and then crushed with a crusher to obtain pellets.

The heat resistance (HDT) of this pellet was 125 ° C.

[I] -2 27 kg of deionized water, a copolymer of methyl methacrylate and a sodium salt of 2-sulfoethyl methacrylate as a dispersant, and 90 g of sodium sulfate were placed in a pressure resistant polymerization kettle having an internal volume of 50.

Further, 75 parts of methyl methacrylate, N-
Monomer solution consisting of 15 parts of (o-chlorophenyl) -maleimide, 9 parts of α-methylstyrene, 0.06 part of n-octyl mercaptan and 0.48 part of azobisisobutyronitrile 18
I put in kg. After charging, add nitrogen while stirring at 200 rpm.
By bubbling for 20 minutes at a rate of 10 / min,
Oxygen in the monomer solution was replaced with nitrogen.

Next, the suspension was polymerized by heating at 80 ° C. for 3.5 hours. Furthermore, the temperature was raised to 105 ° C, and this was kept for 15 minutes, then cooled,
By washing with water and drying, a bead-like polymer having an average particle diameter of 0.3 mm was obtained. The HDT of this polymer was 132 ° C.

[I] -3 Except that 75 parts of methyl methacrylate, 25 parts of N-phenylmaleimide, 0.23 parts of n-octyl mercaptan, 0.1 part of azobisisobutyronitrile and 0.1 part of stearic acid monoglyceride were used as the monomers [I] -3. I] -2 was treated in exactly the same manner as above to obtain a beaded polymer. Of this polymer
HDT was 126 ° C.

[I] -4 72 parts of methyl methacrylate as a monomer, 5 parts of α-methylstyrene, 9 parts of styrene and Nt-butylmaleimide
Except for using 14 parts, the same treatment as in [I] -2 was carried out to obtain a beaded polymer. HDT was 122 ° C.

[I] -5 As monomers, 80% methyl methacrylate, 12% N-cyclohexylmaleimide, 8% α-methylstyrene, n-
Except for using 0.1% of octyl mercaptan and 0.36% of azobisisobutyronitrile, the same treatment as in [I] -2 was carried out to obtain a bead-like polymer of HDT 120 ° C.

[I] -6 As monomers, methyl methacrylate 84%, N-cyclohexyl maleimide 16%, n-octyl mercaptan 0.25
% And azobisisobutyronitrile 0.1% were used, and the same treatment as in [I] -2 was performed to obtain a HDT 117 ° C. bead-shaped polymer.

(2) Method for preparing graft copolymer [III] [III] -1 As rubber component, 6000 g of butyl acrylate, 4000 g of 1,3-butadiene, diisopropylbenzene hydroperoxide 2
0 g, tallow fatty acid potassium 100 g, sodium N-lauroyl sarcosinate 50 g, sodium pyrophosphate 50 g, ferrous sulfate 0.5 g, dextrose 30 g and deionized water 2000 g were used. Of these, with respect to substances other than 1,3-butadiene, oxygen contained therein was replaced with nitrogen in the same manner as in [I] -2, so that the polymerization reaction was not substantially hindered.

Then, this mixture was charged into an autoclave having an internal volume of 40, heated at 50 ° C. for 9 hours and polymerized to obtain a rubber latex. The conversion rate was 97% and the average particle size of the rubber latex was 0.70 μm.

To the rubber latex having a solid content of 10,000 g in the rubber latex, deionized water 9,000 g, sodium formaldehyde sulfoxylate 20 g, and sodium N-larloyl sarcosinate 50 g were added.

Then, after raising the temperature to 75 ° C, methyl methacrylate 4320
g, ethyl acrylate 180g, n-octyl mercaptan
6.75 g and cumene hydroperoxide 16 g were continuously charged and polymerized for 90 minutes. After that, at 75 ° C
Polymerization was carried out for 60 minutes to obtain a latex of copolymer. The conversion of methyl methacrylate was almost 100%.

The polymer latex thus obtained was added with 58 g of styrenated phenol and 44 g of dilauryl thiodipropionate.
And 58 g of triphenyl phosphite were added, and 0.25% sulfuric acid water was added under the temperature condition of 50 ° C. so that the ratio of latex / water was 1/2, thereby coagulating. After this, the temperature was further held at 85 ° C. for 5 minutes.

The resulting slurry polymer is washed and dehydrated at 65 ° C.
After drying for 36 hours, a white powdery graft copolymer was obtained.

[III] -2 Graft copolymerization was carried out in the same manner as in [III] -1, except that butyl acrylate 9,000 g, 1,3-butadiene 1,000 g and 1,3-butylene dimethacrylate 50 g were used as rubber components. Got united.

[III] -3 Using 10,000 g of 1,3-butadiene as a rubber component, 4,800 g of methyl methacrylate as a graft copolymerization component,
Styrene 480g, N- (o-chlorophenyl) maleimide
A graft copolymer was obtained in the same manner as in [III] -1, except that 720 g, 6 g of n-octyl mercaptan and 20 g of cumene hydroperoxide were used.

[III] -4 First step of polymerizing a monomer mixture consisting of butyl acrylate 80%, styrene 19% and allyl methacrylate 1%,
100 parts of the polymer obtained in this first step and 60 parts of a monomer mixture consisting of 99% methyl methacrylate and 1% methyl acrylate are polymerized in the second step, a total of 2 parts.
A graft copolymer was obtained by emulsion polymerization in stages.

[III] -5 First stage of polymerizing 25 parts by weight of a monomer mixture consisting of 97/1/2 weight ratio of methyl methacrylate / methyl acrylate / 1,3-butylene dimethacrylate, butyl acrylate / styrene / 2nd stage of polymerizing 75 parts by weight of a monomer mixture consisting of 80/18 / 1.0 / 1.0 weight ratio of allyl methacrylate / 1,3-butylene dimethacrylate / methyl methacrylate /
Of monomer mixture consisting of 99/1 weight ratio of methyl acrylate
A graft copolymer was obtained by emulsion polymerization consisting of a total of three stages of polymerizing 60 parts by weight.

[III] -6 Methyl methacrylate / acrylic methacrylate 99.5 /
First step of polymerizing 10% by weight of the monomer mixture consisting of 0.5% by weight, 15% of the monomer mixture consisting of 50/40 / 9.5 / 0.5% by weight of methyl methacrylate / butyl acrylate / styrene / allyl methacrylate. The second stage of polymerizing parts by weight,
Butyl acrylate / styrene / allyl methacrylate
The third step of polymerizing 50 parts by weight of the monomer mixture consisting of 80/19 / 1.0 weight ratio, 50/40 / 9.5 / 0.5 of methyl methacrylate / butyl acrylate / styrene / allyl methacrylate
Polymerizing 10 parts by weight of monomer mixture consisting of weight ratio
A graft copolymer was obtained by emulsion polymerization consisting of a total of five steps, a fifth step of polymerizing 15 parts by weight of a monomer mixture consisting of a methyl methacrylate / methyl acrylate 99/1 weight ratio.

[III] -7 of butyl acrylate / styrene / allyl methacrylate
Polymerization of 90 parts by weight of a monomer mixture having a ratio of 80/19 / 1.0, 60 parts by weight of a monomer mixture having a ratio of methyl methacrylate / methyl acrylate of 99/1 Graft copolymerization by emulsion polymerization consisting of a second step, a total of three steps of polymerizing 10 parts by weight of a monomer mixture consisting of butyl acrylate / styrene / allyl methacrylate in a weight ratio of 80/19 / 1.0. Got united.

[III] -8 of monomer mixture consisting of methyl methacrylate / methyl acrylate / 1,3-butylene dimethacrylate 98/1/1 weight ratio
First step of polymerizing 20 parts by weight, 8 of a monomer mixture consisting of 80/18 / 1.0 / 1.0 weight ratio of butyl acrylate / styrene / allyl methacrylate / 1,3-butylene dimethacrylate.
Second stage to polymerize 0 parts by weight, 98.5 of methyl methacrylate / methyl acrylate / 1,3-butylene dimethacrylate
The third step of polymerizing 10 parts by weight of the monomer mixture in the ratio of 1.0 / 0.5 / 1.0, the polymerization of 50 parts by weight of the monomer mixture in the ratio of 99/1 of methyl methacrylate / methyl acrylate. A graft copolymer was obtained by emulsion polymerization consisting of a total of 4 stages.

[III] -9 Polymerization of a monomer mixture consisting of 75.3% butyl acrylate, 23.7% styrene and 1% allyl methacrylate 1st
Step, 100 parts of the polymer obtained in the first step, and 92% of methyl methacrylate and 8% of styrene with respect to the polymer.
A graft copolymer was obtained by a second step in which 60 parts of a monomer mixture consisting of was polymerized by emulsion polymerization.

Examples 1 to 6 and Comparative Example 1 Each component having the composition shown in Table 1 was melted and kneaded with a Henschel mixer to obtain a composition of the present invention.

Using the obtained composition, a cylinder temperature of 190 to 2 was obtained with a twin-screw extruder PCM-30 (trade name, manufactured by Ikegai Tekko KK).
Pelletized by extrusion at 50 ° C. Using these pellets, a screw type automatic injection molding machine V-17-65 type (trade name, manufactured by Japan Steel Works) was used to obtain a cylinder temperature of 250.
Injection molding under conditions of ℃, mold temperature 60 ℃ and injection pressure (gauge pressure) 50kg / cm ² , 110 × 110 × 2 (thickness) mm, 70 × 125 × 6.5
A (thickness) mm test piece was obtained.

Using this test piece, the following tests were conducted. The results are shown in Table 1.

Heat distortion resistance test: According to ASTM-D-648.

Total light transmittance and haze value: According to ASTM-D-1003-52.

Izod impact strength: According to ASTM-D-256-54T.

Charge half-life: Measured with Honestmate (manufactured by Shishido Shokai) at a temperature of 20 ° C and a humidity of 50%.

Surface resistivity: By super insulation resistance tester (manufactured by Takeda Riken),
It was measured under the conditions of a temperature of 20 ° C. and a humidity of 50%.

Fly ash test: Put cigarette ash in a petri dish,
At a height of 5 cm above the wool surface, a test piece that had been rubbed 50 times back and forth was held over the wool surface to check the adhesion of ash.

As is clear from the results of Table 1, Examples 1 to 6 of the present invention
The composition (1) also had good transparency and exhibited excellent antistatic properties.

Examples 7 to 25 and Comparative Examples 2 to 3 Each component having the composition shown in Table 2 was kneaded with a Henschel mixer to obtain a composition of the present invention. Using the obtained composition, a test piece was obtained in the same manner as in Examples 1 to 6. The results are shown in Table 2.

The compound without the compound [II] (Comparative Example 2) did not exhibit antistatic performance. Further, when the compounding ratio of the compound [II] exceeds the upper limit of the compounding ratio of the present invention, the antistatic property is exhibited, but the heat resistance is lowered, and further the tackiness is recognized on the surface of the test piece (comparative). Example 3). On the other hand, no tackiness was observed in the test pieces of the examples.

Further, those using methacrylic resins other than the methacrylic resin [I] used in the present invention were inferior in heat resistance.

Example 26 Methyl methacrylate 720 g, α-methylstyrene 85 g, N
To a mixture of 115 g of-(o-methylphenyl) maleimide and 80 g of disodium monooctadecyl phosphate, JP-504 (release agent, trade name, manufactured by Johoku Chemical Co., Ltd.) 0.5
g and azobisisobutyronitrile 0.5 g were added and dissolved to obtain a methacrylic resin composition of the present invention. This is then 3mm through a polyvinyl chloride gasket.
In the cell formed by two tempered glass facing each other at the interval of
After pouring, it was immersed in warm water at 65 ° C. and polymerized for 16 hours. Then, it was kept in an air heating furnace at 115 ° C. for 2 hours to obtain a transparent methacrylic resin plate. Using this resin plate,
The following tests were conducted. The test method was the same as in Example 1, and the bending strength was tested according to ASTM-D-790.

HDT is 109 ° C, and surface resistivity is 2.
It was 6 × 10 ¹⁰ Ω and 3.3 × 10 ¹⁰ Ω. In the fly ash test, no ash adhesion was observed, and there was no surface stickiness. The bending strength was 1224 kg / cm ² , and the mechanical properties were excellent.

Examples 27 to 33 and Comparative Example 4 Compositions of the present invention were obtained in the same manner as in Example 26 except that the mixture having the composition shown in Table 3 was used.

Using this composition and in the same manner as in Example 26, a transparent methacrylic resin plate was obtained. Example using this resin
A test similar to 26 was performed. The results are shown in Table 3. As is clear from the table, the composition of the present invention was excellent in heat resistance and antistatic performance, and was also excellent in mechanical properties.

In each of the compositions of Examples 27 to 33, the HDT when only the methacrylic resin [I] was used was 110 ° C. or higher.

[Effects of the Invention] The composition of the present invention has excellent heat resistance and antistatic properties, and also has excellent impact resistance, and its industrial value is extremely large. Instrument parts,
It can be used as a material for electric parts such as vehicle parts and audio equipment; parts for OA equipment; parts for optical equipment; various disks;

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location C08K 5/52 C08L 33/12 LJC 51/04 LKY

Claims (4)

[Claims] 1. [I] 40% by weight of methyl methacrylate unit
50 to 99.8% by weight of a methacrylic resin having a heat distortion temperature of 105 ° C. or higher, which is a copolymer containing the above and a maleic anhydride unit and / or an N-substituted maleimide unit, and [II] the following formulas (A) and (B ), (C), (D),
(E), (F), (G) and (H) (In these formulas, R, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ and R
_{9's, which} may be the same or different, each represents hydrogen or an acyl group having 8 to 20 carbon atoms; R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and
R _{15 s} may be the same as or different from each other and have 1 carbon atom.
Represents ~ 18 alkyl _{group; R 16, R 17, R} 18 and R _19, which may be said even identical to each other, represents an alkyl group having 8 to 20 carbon atoms; M, M _1, M ₂ , M ₃ and M _{4, which} may be the same or different, each represents a hydrogen atom, a sodium atom, a potassium atom and a lithium atom; and n represents a number of 1 to 50. )
The rubber component containing 10 to 0.2% by weight of at least one compound selected from the group of compounds represented by, and [III] 1,3-butadiene and / or acrylic acid ester unit of 50% by weight or more is substituted with methyl methacrylate. Alternatively, it is composed of 0 to 49.8% by weight of a graft copolymer obtained by graft-polymerizing at least one vinyl monomer selected from unsubstituted styrene and acrylonitrile, and the total amount of each component of [I] to [III]. Is 100% by weight, a methacrylic resin composition. 2. A methacrylic resin comprising 40 to 90% by weight of methyl methacrylate unit, 5 to 20% by weight of maleic anhydride unit, and α
-Methylstyrene units 0-20% by weight and styrene units 5
The methacrylic resin composition according to claim 1, wherein the methacrylic resin composition is a copolymer composed of about 20% by weight. 3. A methacrylic resin comprising a methyl methacrylate unit of 40 to 96% by weight and an N-substituted maleimide unit of 4 to 35% by weight.
The methacrylic resin composition according to claim 1, which is a copolymer comprising 0 to 25% by weight of an aromatic vinyl compound unit. 4. The N-substituted maleimide is an N-alkyl maleimide having an alkyl group having 1 to 5 carbon atoms, N-cyclohexyl maleimide, N-benzyl maleimide and N-.
The methacrylic resin composition according to claim 3, which is at least one selected from the group consisting of arylmaleimide and halogen and / or alkyl substitution products thereof.