JPH0781062B2 - Impact-resistant methacrylic resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a methacrylic resin composition having excellent impact resistance, and more specifically, a specific amount of two types of rubber components having specific structures and particle sizes. And a methacrylic resin composition having excellent transparency and surface gloss, which is obtained by blending a specific amount of a methacrylic resin containing methyl methacrylate as a main constituent unit and which exhibits good impact resistance.

[Conventional technology]

Among the plastic materials, methacrylic resin has outstanding properties such as transparency, optical properties, surface gloss, surface hardness, and mechanical properties, and also has excellent properties such as weather resistance and moldability. is doing. Utilizing these characteristics, it is used in various fields such as lighting equipment, signboards, window materials, optical lenses, vehicle parts and various displays.

However, the methacrylic resin has a problem that the impact resistance is insufficient, and its improvement is strongly desired in each application field.

A technique for imparting impact resistance to the methacrylic resin without impairing its original properties has been studied for a long time. The present inventors have previously polymerized a monomer mixture of an acrylic acid alkyl ester, an aromatic vinyl-based monomer, and allyl (meth) acrylate in a specific composition range in the presence of a first step of a characteristic amount. In addition, a specific amount of a rubber-like elastic body obtained by polymerizing a specific amount of the second stage containing methyl methacrylate as a main component and graft-copolymerizing methyl methacrylate, and a specific amount of a methacrylic resin containing methyl methacrylate as a main component. Blending method (Japanese Patent Publication No. Sho 54-18298) and the main component of this method is the alkyl acrylate and aromatic vinyl-based monomer present inside the second stage with methyl methacrylate as the main component. Within the first step, which is a copolymer of the monomer mixture, there are three or more different structures having a core of a hard resin containing methyl methacrylate as a main constituent unit. A blended resin composition (USP 4,433,103, JP-A-58-180514) of a rubber-like elastic material and a methacrylic resin containing methyl methacrylate as a main constituent unit was proposed.

According to the former method described above, although a resin composition having excellent surface gloss and transparency can be obtained, a large amount of a rubber component needs to be blended in order to impart impact resistance. Compared with the straight methacrylic resin, the tensile strength and the toughness such as bending modulus were lowered, and at the same time, the heat resistance, the surface hardness, the flow processability and the like tended to be lowered. On the other hand, the latter blended resin composition is superior in toughness such as tensile strength and bending modulus, and is also excellent in impact resistance as compared with a straight methacrylic resin, but is slightly inferior in transparency and surface gloss. A trend was recognized.

As another method, a method of graft-polymerizing a vinyl-based monomer in the presence of two kinds of acrylic ester rubber latexes having different particle diameter ranges has been proposed (Japanese Patent Publication No. 58-45446). In the method, the degree of grafting of the vinyl monomer onto the rubber having two different particle diameters is different, and the nitrile-based or aromatic-based monomer is used as the preferred graft polymerization monomer. When viewed as a methacrylic resin, it is not practical because it is unsatisfactory in terms of optical properties and the like.

[Problems to be solved by the invention]

The object of the present invention is to eliminate the above-mentioned drawbacks, transparency,
It is an object of the present invention to provide a methacrylic resin composition having excellent impact resistance without impairing the original properties of the methacrylic resin such as surface appearance, moldability, heat resistance and mechanical strength.

[Means for solving problems]

As a result of intensive studies to solve the above-mentioned drawbacks, the present inventors have found that in a methacrylic resin composition containing two types of special rubber-like particles having different internal structures and particle sizes,
The inventors have found that the intended purpose is achieved, and have completed the present invention.

The impact-resistant methacrylic resin composition of the present invention comprises a methacrylic resin [I] 10 whose main constituent unit is methyl methacrylate.
~ 90 wt%, rubber component [II] and rubber component [III] 9
A resin composition comprising 0 to 10% by weight, wherein the resin composition comprises (A): the rubber component [II] having 2 to 5 carbon atoms in the alkyl group.
At least one alkyl acrylate ester of 8 69.9
~ 89.9% by weight, styrene or a mixture of styrene and its derivatives 30 to 10% by weight, acrylic acid, methacrylic acid, cinnamic acid, sorbic acid, cyanuric acid, isocyanuric acid, maleic acid, succinic acid, phthalic acid, isophthalic acid and 0.1-5% by weight of a polymerizable polyfunctional substance (α) which is an ester of at least one acid component selected from the group consisting of trimellitic acid and at least one unsaturated alcohol component of allyl alcohol and methallyl alcohol, The first layer obtained by polymerizing 100 parts by weight of a monomer mixture consisting of 0 to 5% by weight of another copolymerizable polyfunctional monomer and 0 to 20% by weight of another copolymerizable monomer ( a), and the first layer (a)
80% to 100% by weight of methyl methacrylate in the presence of
And a second layer (b) obtained by polymerizing 10 to 100 parts by weight of a monomer or a mixture thereof containing 20% to 0% by weight of a copolymerizable monomer. (B): the rubber component [III] contains 40% by weight or more of methyl methacrylate units, and is selected from a methyl methacrylate unit and an alkyl acrylate having an alkyl group with 1 to 8 carbon atoms. In the presence of the first layer (c), the first layer (c), obtained by polymerizing 1 to 60% by weight of a monomer or a mixture thereof having a total of at least one unit of 80% by weight or more, 69.8 to 89.9% by weight of at least one kind of alkyl acrylate having an alkyl group having 2 to 8 carbon atoms, 30 to 10% by weight of styrene or a mixture of styrene and a derivative thereof, the polymerizable polyfunctional substance (α) 0.1 to 5 % By weight, other copolymerizable polyfunctional monomer 0.1 to 5% by weight % And other copolymerizable monomer 0 to 20% by weight, a second layer (d) and a first layer (c) obtained by polymerizing 99 to 40 parts by weight of a monomer mixture.
And 100 parts by weight of a two-layer rubber-like substance consisting of the second layer (d), 80 to 100% by weight of methyl methacrylate, 0 to 5% by weight of a copolymerizable polyfunctional monomer, and other copolymers. A monomer or a mixture thereof composed of 0 to 20% by weight of a polymerizable monomer is mixed at an arbitrary ratio within the above range once or several times, and 10
It is a three-layer structure polymer comprising a third layer (e) obtained by polymerizing 1000 parts by weight to (C): the particle diameter of the rubber component [II] is 0.05 at the stage of the first layer (a). ˜0.15 μm, the particle size of the rubber component [III] is 0.18 to 0.45 μm in the steps up to the second layer (d), and (D): the weight ratio of the rubber component [II] and the rubber component [III] is [ II] / [III] = 1/6 to 6/1, and (E): the methacrylic resin [I], the rubber component [II] and the rubber component [III] are first blended with the rubber component [II]. A method of mixing the rubber component [III] and then blending with the methacrylic resin [I], or individually mixing the methacrylic resin [I] and the rubber component [II], or the methacrylic resin [I] and the rubber component [III]. And then performed by any one of the methods of blending both.

[Preferable Embodiments for Carrying Out the Invention]

The methacrylic resin [I] having methyl methacrylate as a main constituent unit used in the present invention is
It is a polymer of 0% by weight and 0 to 20% by weight of other vinyl or vinylidene monomer, for example, an alkyl acrylate having an alkyl group having 1 to 4 carbon atoms.

In the present invention, two kinds of rubber component [II] and rubber component [III] having different internal structures and particle sizes are used.

The first layer (a) of the rubber component [II] and the second layer (d) of the rubber component [III] in the present invention are an alkyl acrylate whose alkyl group has 2 to 8 carbon atoms, preferably n.
At least one of butyl acrylate and 2-ethylhexyl acrylate 69.9 to 89.9% by weight (first layer (a)) or 69.8 to 89.8% by weight (second layer (d)), styrene alone or a mixture of styrene and its derivative 30 to Ten
%, At least one acid component selected from the group consisting of acrylic acid, methacrylic acid, cinnamic acid, sorbic acid, cyanuric acid, isocyanuric acid, maleic acid, succinic acid, phthalic acid, isophthalic acid, and trimellitic acid, and allyl. At least one of alcohol and methacrylic alcohol
69.9 to 89.9% by weight (first layer (a)) or 69.8 to 89.8% by weight (second layer (d)), styrene alone or a mixture of styrene and its derivative 30 to 10% by weight, acrylic acid, methacrylic acid, cinnamon At least one acid component selected from the group consisting of acids, sorbic acid, cyanuric acid, isocyanuric acid, maleic acid, succinic acid, phthalic acid, isophthalic acid, and trimellitic acid, and at least one unsaturated of allyl alcohol and methacrylic alcohol 0.1-5% by weight of a polymerizable polyfunctional substance (α) which is an ester with an alcohol component, 0-5% by weight of a crosslinkable monomer which is copolymerizable with these and has two or more carbon-carbon double bonds ( One layer (a)) or
It is a copolymer of a monomer mixture consisting of 0.1 to 5% by weight (second layer (d)) and 0 to 20% by weight of another copolymerizable monomer.

The composition ratio of the acrylate monomer and styrene or a mixture of styrene and a derivative thereof is one of the important factors for the resin composition of the present invention to have a high degree of transparency, Other than that, the transparency decreases.
The polymerizable polyfunctional substance (α) is also one of the most important factors constituting the present invention, and thereby the object of the present invention is achieved. Although the details of its action are not clear, the degree of crosslinking of the first layer (a) of the rubber component [II] and the second layer (d) of the rubber component [III] and the graft polymerizability with methyl methacrylate are balanced. It is presumed that it is well controlled. The amount added, although the appropriate value is different depending on whether it is used alone or in combination, 0.1
A range of up to 5% by weight is suitable.

Further, the polyfunctional monomer used here is not particularly limited and various ones can be used, for example, ethylene glycol (meth) acrylate, 1,3-butylene di (meth) acrylate, tetraethylene glycol. Examples include di (meth) acrylate and divinylbenzene.

The composition of the first layer (c) of the rubber component [III] contains at least 40% by weight of methyl methacrylate units, and is at least selected from methyl methacrylate units and alkyl acrylates having 1 to 8 carbon atoms. It is a polymer containing a total of 80% by weight or more of one unit.

In the present invention, the intended resin composition can be obtained by making the first layer (c) of the rubber component [III] have a specific composition as described above. Next, an example of a preferred embodiment will be described in detail as the first layer (c) of the rubber component [III], but this does not limit the present invention.

Examples of the composition of the first layer (c) of the rubber component [III] include methyl methacrylate units of 80 to 100% by weight and alkyl group-containing acrylic acid acrylic ester units of 1 to 8 carbon atoms.
From 0 to 20% by weight, from a methyl methacrylate unit of 60 to 85% by weight, a cyclohexylmethacrylate unit of 5 to 20% by weight, and an alkyl group having 1 to 8 carbon atoms of an acrylic acid alkyl ester unit of 10 to 20% by weight. Copolymer, 50 to 70% by weight of methyl methacrylate unit, 10 to 20% by weight of benzyl acrylate unit and 1 carbon atom of alkyl group
.About.8, a copolymer of 20 to 30% by weight of alkyl acrylate unit, and the like.

Is a polyfunctional monomer having two or more acryloyloxy groups and / or methacryloyloxy groups in one molecule, which is a copolymer of the above monomer mixture containing 0.1 to 10% by weight of a crosslinkable monomer. More preferably, it is a polymer. The polyfunctional monomer is not particularly limited, but ethylene glycol di (meth) acrylate, 1,3
-Butylene di (meth) acrylate, 1,4-butanediol di (meth) acrylate and the like can be mentioned.

Rubber component [II] and rubber component [III] in the present invention
In the presence of a two-layer rubber-like substance consisting of the first layer (a) of the rubber component [II] or the first layer (c) and the second layer (d) of the rubber component [III], respectively. It is a polymer of a monomer or a mixture of monomers. Rubber component [II]
Second layer (b) and third layer (e) of rubber component [III]
The composition of the monomer or monomer mixture in the above is composed of 80 to 100% by weight of methyl methacrylate and 0 to 20% by weight or less of other vinyl-based monomer copolymerizable therewith. Regarding the third layer (e) of the component [III], the first layer (a) of the rubber component [II] and the rubber component [II]
It is also possible to copolymerize 0 to 5 parts by weight of a polyfunctional monomer of the same type as that used in the second layer (d) of I] depending on the application.

Other vinyl-based monomers copolymerizable with methyl methacrylate include styrene, acrylonitrile, and methacrylic acid, and particularly preferred are alkyl acrylates such as methyl acrylate, ethyl acrylate, and butyl acrylate. When the content of methyl methacrylate in the monomer or monomer mixture is less than 80% by weight, the properties such as transparency and heat resistance are poor. If the amount of the monomer other than the acrylic ester exceeds 10% by weight, it is not preferable in terms of transparency, heat resistance or water resistance.

In the production of the rubber component [III] in the present invention, the production of the third layer (e) which is carried out in the presence of the two-layer rubber-like substance consisting of the first layer (c) and the second layer (d), It is also possible to polymerize in several steps. For example, when a polyfunctional monomer or a monomer mixture to which a polymerization degree control agent is added, a crosslinkable monomer or a polymerization degree control agent is added. Polymerization can be carried out separately in a portion and a portion not added.

That is, the third layer (e) produced in the presence of the two-layer rubber-like substance consisting of the first layer (c) and the second layer (d) has 80 to 99.9% by weight of methyl methacrylate, a copolymerizable polyfunctional compound. Monomer
Layer (e1) of the first stage obtained by polymerizing a graft-crosslinkable monomer mixture consisting of 0.1 to 5% by weight and other copolymerizable monomer 0 to 19.9% by weight, methyl methacrylate 80 to 100% by weight %, Other copolymerizable monomer 0 to 20% by weight of a graft non-crosslinkable monomer or a mixture of monomers obtained by polymerizing the second stage layer (e2). , The composition ratio of the first-stage layer (e1) to the second-stage layer (e2) is (e1)
/ (E2) = 1/3 to 1/999, and the layer (e1) of the first stage is added to 100 parts by weight of the two-layer rubber-like substance consisting of the first layer (c) and the second layer (d). 1 to 100 parts by weight, and the second stage layer (e2) is preferably 9 to 999 parts by weight.

The larger the molecular weight of the third layer (e) of the rubber component [III] is, the more advantageous it is for impact resistance, but on the other hand, it may cause deterioration of fluidity and surface appearance characteristics. On the other hand, when the molecular weight is small, the fluidity and the surface appearance characteristics are good, but the impact resistance may decrease. Therefore, in some cases, a part of the third layer (e) is crosslinked to have a high molecular weight, and the rest is made non-crosslinked to have a low molecular weight, so that impact resistance, fluid processability,
It is also possible to provide a composition having excellent surface characteristics.

The weight ratio of the first layer (c) and the second layer (d) of the rubber component [III] is (c) / (d) = 1 when the total amount of (c) and (d) is 100 parts by weight. -60 / 99-40 parts by weight, more preferably 5-50 / 95-50 parts by weight.

Second layer (b) of rubber component [II] and rubber component [III]
The third layer (e) of the rubber component [II] is 100% of the first layer (a).
It is necessary to polymerize up to a range of 10 to 1000 parts by weight with respect to 100 parts by weight of the two-layer rubber-like substance consisting of 1 part by weight, the first layer (c) and the second layer (d) of the rubber component [III]. . If it is less than 10 parts by weight, the improvement of impact resistance is small and the surface gloss is lowered, which is not preferable. on the other hand,
If it exceeds 1000 parts by weight, the productivity is lowered, which is not preferable.

The second layer (b) of the rubber component [II] used in the present invention,
The hard resin segment of the first layer (c) and the third layer (e) of the rubber component [III] and the methacrylic resin [I] are individually required in each polymerization step in order to impart good transparency. The compositions of the monomers excluding the auxiliary agent and the crosslinkable monomer component are preferably the same or very similar. Further, regarding the refractive index of the first stage (a) of the rubber component [I] and the second stage (d) of the rubber component [III] at the elastomer stage containing an alkyl acrylate as a main component, the above-mentioned hard resin segment It is preferable to be very close to

In addition, in the polymerization of each of the above-mentioned monomers or monomer mixtures, a polymerization degree modifier such as mercaptan can also be used, if necessary, in order to adjust the molecular weight. As the polymerization degree control agent that can be used, alkyl mercaptan,
Examples thereof include thioglycolic acid and its ester, β-mercaptopropionic acid and its ester, and aromatic mercaptans such as thiophenol and thiocresol.

As one of the particularly important factors in the methacrylic resin composition of the present invention, the rubber component [II] and the rubber component [III]
There is a range of particle sizes. That is, in the steps up to the first layer (a) of the rubber component [II] and the second layer (d) of the rubber component [III], the particle diameters are 0.05 to 0.15 μm and 0.18 to 0.45 μm, respectively.
It must be in the range of m. The resin composition of the present invention cannot be obtained with a rubber component having particle particles other than the above.

The methacrylic resin composition of the present invention is produced by blending three components of methacrylic resin [I], rubber component [II] and rubber component [III].

The total amount of the two rubber components blended with the methacrylic resin is 10 to 90% by weight in the methacrylic resin composition, and the weight ratio of the rubber component [II] and the rubber component [III] is [II] /
It is necessary to set [III] = 1/6 to 6/1. Outside the above range, the characteristics of the resin composition of the present invention are not effectively exhibited.

The methacrylic resin and the rubber component are blended by first mixing the rubber component [II] and the rubber component [III] and then blending with the methacrylic resin [I], or by mixing the methacrylic resin [I] and the rubber component [II]. First, the methacrylic resin [I] and the rubber component [III] are individually mixed, and then the both are blended. If other methods such as methacrylic resin [I], rubber component [II] and rubber component [III] are mixed at the same time, the three components may not be uniformly mixed, and uneven dispersion (division phenomenon) may occur. However, it tends to cause fluctuations in the characteristics of the obtained resin composition.

Further, the relationship between the total weight (W) of each blend component at the time of blending and the internal volume (V) of the device used for blending is (W)
/ (V) is preferably in the range of 0.05 to 0.75 (Kg /). If the amount is out of this range, the blended product may become non-uniform and may adhere to the vessel wall of the blending device, so that the desired methacrylic resin composition may not be obtained. The temperature at the time of blending is V-type tumbler in the form of powder, beads or pellets except for the case where the rubber component [II] and the rubber component [III] are blended together by the latex and co-solidified. When blending using a known blender such as or a Hensiel mixer, the temperature in the tank of the blending device is 70 ° C or lower,
It is particularly preferable to set the temperature in the range of 0 ° C to 50 ° C. There is no particular problem even if the temperature is 0 ° C or lower, but the merit of keeping the temperature at 0 ° C or lower is not clear. However, at 70 ° C. or higher, the rubber component [II] and the rubber component [III] may adhere to each other, which makes it difficult to obtain a uniform methacrylic resin composition.

Since it is particularly preferable that both the rubber component [II] and the rubber component [III] are produced by the emulsion polymerization method, an example of the emulsion polymerization method will be described below.

After adding deionized water and an emulsifier if necessary into the reaction vessel, the monomer (mixture) constituting the first layer of the rubber component [II] or the rubber component [III] is polymerized, and then the presence of the first layer is present. Monomers (mixtures) that make up each second layer below
Add and polymerize. Further, for the rubber component [III], the monomer (mixture) constituting the third layer is added and polymerized in the presence of the rubber-like substance composed of the first layer and the second layer.

The polymerization temperature is 30 to 120 ° C, more preferably 50 to 100 ° C.

Polymerization time, the type and amount of polymerization initiator and emulsifier,
Although it depends on the polymerization temperature and the like, it is usually 0.5 to 7 hours at each polymerization stage.

The ratio of the united body to water is preferably monomer / water = 1/20 to 1/1.

The polymerization initiator and the emulsifier are added to either or both of the aqueous phase and the monomer phase.

Regarding the charging method of each monomer in each polymerization step, the charging may be carried out all at once or in a divided manner, but the divided charging method is more preferable from the viewpoint of heat of polymerization and the like.

The emulsifier can be used without particular limitation as long as it is a commonly used emulsifier, for example, long-chain alkylcarboxylic acid salt,
Examples thereof include sulfosuccinic acid alkyl ester salts and alkylbenzene sulfonates.

The type of the polymerization initiator can also be used without particular limitation.For example, a water-soluble inorganic initiator such as persulfate or perborate alone or as a redox initiator in combination with sulfite, thiosulfate or the like. It can also be used. Also, redox initiators such as organic hydroperoxide-ferrous salt, organic hydroperoxide-sodium sulfoxylate, and initiators such as benzoyl peroxide and azobisisoptyronitrile can be used.

The polymer latex obtained by the emulsion polymerization method is coagulated and dried by a known method.

In order to obtain the resin composition of the present invention by mixing the rubber component [II] and the rubber component [III] thus obtained with the methacrylic resin [I], a method by melt mixing is ideal. Prior to melt mixing, in addition to the above resin composition components,
If necessary, stabilizers, lubricants, plasticizers, dyes and pigments, fillers, etc. are appropriately added, and after blending by the above method, using a mixing roll, a screw type extruder or the like, 150 ° C to 300 ° C
Melt and knead.

By molding the methacrylic resin composition thus obtained using an extrusion molding machine, an injection molding machine, or the like, a molded article excellent in transparency and surface gloss and rich in impact resistance can be obtained.

〔The invention's effect〕

The methacrylic resin composition of the present invention has transparency, surface appearance,
It does not impair the original excellent properties of methacrylic resin such as weather resistance and flow processability, and is also excellent in mechanical strength and impact resistance.

〔Example〕

Hereinafter, the present invention will be described in more detail based on examples. In the examples, "part" means "part by weight" and "%" means "% by weight".

Examples 1, 1A, 1B, Comparative Example 1 (1) Manufacture of rubber component [II] (1-1) Manufacture of first layer (a) A reaction vessel made of stainless steel having an internal volume of 50 was prepared by ) And (b) are charged, nitrogen is blown into the mixture under stirring to make it substantially unaffected by oxygen, the temperature is raised to 65 ° C, the following (c) source is added, and the temperature is raised to 80 ° C. The temperature was raised and the polymerization was continued for 90 minutes. Then, the raw material of (b) again
5 kg was continuously added over 90 minutes and the weight was further increased for 120 minutes to obtain an acrylic latex.

(A) Raw material Deionized water 30Kg N-lauroyl sarcosine sodium (S-LN) 100g Boric acid 100g Sodium carbonate 10g * 1: N-acyl sarcosinate (Nikko Chemicals Co., Ltd.)
(B) Raw material Butyl acrylate (BA) (80%) 4Kg Styrene (ST) (19%) 950g Allyl methacrylate (AMA) (1%) 50g Cumene hydroperoxide (CHP) 15g (C) Raw material Deionized water 500g Sodium formaldehyde sulfoxylate (hereinafter,
In this polymerization, the polymerization rate of BA was 98% and the polymerization rate of ST was 99%. The particle size of the obtained latex was 0.08 μm as a result of measurement by an absorbance method.

(1-2) Production of second layer (b) In the same reaction vessel in which the latex containing the solid content of 10 kg (100 parts) of the first layer (a) is present, (d) raw material, deionized water 500 g S After adding 25 g of -LN and stirring, 80 parts of the following raw material (e) was continuously added at a rate of 40 parts / hour while maintaining the temperature at 80 ° C.
Thereafter, the polymerization was continued for another hour. Then, a rubber component [II], which is a graft copolymer, was obtained in a latex form. The polymerization rate of the raw material (e) monomer was 99.5% or more.

(E) Raw material Methyl methacrylate (MAM) (96.0%) 7680g Ethyl acrylate (EA) (4%) 320g Normal octyl mercaptan 28g CHP 24g This latex is coagulated and washed by the following method.
It was dried to obtain a rubber component powder having a multiple structure.

Charge 50% 1.0% sulfuric acid water into a stainless steel container, raise the temperature to 85 ° C under stirring, add 25 kg of the latex produced above continuously over 15 minutes, and then raise the internal temperature to 90 ° C. And held for 5 minutes. After cooling to room temperature, the polymer was separated and washed with deionized water to obtain a white cream-like polymer, which was dried under the condition of 76 ° C. × 36 hours to obtain a white powdery polymer.

(2) Manufacture of rubber component [III-1] (2-1) Manufacture of first layer (c) In a reaction vessel made of stainless steel with an internal volume of 50, the following raw materials (F-1) were first added. After blowing nitrogen under stirring to make the state substantially free from the influence of oxygen, the temperature was raised to 70 ° C., the following raw materials (T-1) were added, and polymerization was carried out for 2 hours. Got the latex.

(F-1) Raw material Deionized water 20Kg S-LN 16g Boric acid 80g Sodium carbonate 8g MMA (97%) 1940g EA (1%) 20g 1,3-Butylenedimethacrylate (BDMA) (2%) 40g -1) Raw material Deionized water 500 g Potassium persulfate (KPS) 24 g (2-2) Production of the second layer (d) 20 parts by solid content after the polymerization of (2-1) above was substantially completed. In the above-mentioned container containing a corresponding amount of hard crosslinked resin latex, the following (chi-1) aqueous solution was added and the temperature was raised to 80 ° C., after which the following (ri-1) raw material was spread over 150 minutes. Was continuously added. After the completion of the addition, the polymerization was further continued for 3 hours to obtain a latex of an acrylic elastic body having a multiple structure containing a hard crosslinked resin inside the particles.

(H-1) Raw material S-LN 30g Rongalit 32g Deionized water 500g (li-1) Raw material BA (80%) 6400g ST (18%) 1440g Allyl cinnamate (ACM) (1.5%) 96g 1,4 - butanediol diacrylate (C ₄ -DA) (0.5
%) 32 g t-butyl hydroperoxide (TBH) 23 g In the above case, the polymerization yields of BA and ST were 97% and 99.5% or more, respectively, and the particle size of the obtained latex was measured by the absorbance method. It was 0.26 to 0.28 μm.

(2-3) Production of third layer (e) The following (nu-1) aqueous solution was placed in the above container containing the latex corresponding to 100 parts of the solid content obtained in the above polymerization (2-2). After the addition and stirring, the monomer mixture of (l-1) below was continuously added over 2.5 hours. Then, the polymerization was further continued for 1 hour to obtain a rubber component [III-1] in a latex form. MMA polymerization yield of monomer mixture is 99.5%
That's all.

(Nu-1) Raw material S-LN 20g Deionized water 500g (lu-1) Raw material MMA (96%) 4800 g EA (4%) 200 g Normal octyl mercaptan (n-C ₈ SH) 12.5g TBH 5 g Coagulation, cleaning, and cleaning of this latex by the method described below.
It was dried to obtain a powder of rubber component [III-1]. That is, 60% of 1.0% sulfuric acid water was charged into a stainless steel container,
The temperature was raised to 80 ° C. with stirring, 35 kg of LATEX was continuously added over 20 minutes, and then the internal temperature was raised to 95 ° C. and kept for 5 minutes. After cooling to room temperature, the polymer was separated and washed with deionized water to obtain a white cream-like polymer.
It was dried at ℃ for 24 hours to obtain a white powdery polymer.

(3) Production of rubber components [III-2] to [III-4] Using the same reactor used in (2), the raw material of (f-2) was charged first, and the mixture was stirred as shown below (f). (2A) 802.4 g of the monomer mixture was added all at once, and nitrogen gas was blown into the mixture to make it substantially unaffected by oxygen, then the temperature was raised to 70 ° C and the raw materials (ii) below were added. Polymerization for 60 minutes,
After that, the monomer mixture of (H-2B) shown in Table-1 1203.6
g was continuously added over 30 minutes for polymerization, and after the completion of addition, the polymerization was continued for 90 minutes.

(F-2) Raw material Deionized water 25 g N-lauroyl sarcosine sodium (hereinafter referred to as "S-L
8 g nitric acid 100 g sodium carbonate 10 g ferrous sulfate 0.01 g ethylenediamine-4-acetic acid-2-sodium (hereinafter referred to as “N”)
0.04g called "EDTA-2Na" After the temperature was raised to 80 ° C., the following raw material (T-2) was added, and the raw material (H-2) below was continuously added thereto over 150 minutes. After the completion of the addition, the polymerization was further continued for 3 hours to obtain a latex of an acrylic elastic body having a multiple structure containing a hard crosslinked resin inside the particles.

(G-2) Raw material S-LN 30g Rongalit 32g Deionized water 500g (Chi-2) Raw material BA (80%) 5120g ST (18%) 1152g Allyl cinnamate (ACM) (1.5%) 96g 1,4 - heptane diacrylate (C ₄ -DA) (0.5
%) 32 g t-butyl hydroperoxide (TBH) 23 g In the above case, the polymerization yields of BA and ST were 97% and 99.5% or more, respectively, and the particle size of the obtained latex was measured by the absorbance method. It was 0.26 to 0.28 μm.

(3-3) Production of third layer (e) In the container containing the latex corresponding to 100 parts of the solid content obtained by the above polymerization, the following aqueous solution (i-2) was added and stirred. After that, add the following (nu-2) monomer mixture to 2.
It was added continuously over 5 hours. Then, the polymerization was further continued for 1 hour to obtain a rubber component [III] in a latex form. The MMA polymerization yield of the monomer mixture was 99.5% or more.

(Ri-2) Raw material sarcosinate LN 20g Deionized water 500g (nu-2) Raw material MMA (96%) 4800 g EA (4%) 200 g Normal octyl mercaptan (n-C ₈ SH) 12.5g TBH 5 g Coagulation, cleaning, and cleaning of this latex by the method described below.
Drying to obtain a powder of rubber component [III]. That is, 60% of 1.0% sulfuric acid water was charged into a stainless steel container and stirred for 8 hours.
The temperature was raised to 0 ° C. and 35 kg of Latex was continuously added over 20 minutes, and then the internal temperature was raised to 95 ° C. and kept for 5 minutes. After cooling to room temperature, the polymer was separated and washed with deionized water to obtain a white creamy polymer, which was heated at 70 ° C.
After drying for 24 hours, a white powdery polymer was obtained.

(4) Production of methacrylic resin [I-1] and [I-2] As methacrylic resin [I], methyl methacrylate / methyl acrylate is 99/1 and the reduced viscosity in chloroform is 0.060 (/ The beaded polymer of g) was produced by a known suspension polymerization method. This is designated as [I-1]. The ratio of methyl methacrylate / methyl acrylate is 90/1
0 and reduced viscosity in chloroform is 0.055 / g
Was produced. This is designated as [I-2].

(5) Manufacture of Methacrylic Resin Composition The methacrylic resin [I-1] obtained above, the rubber component [II], and the rubber component [III] were blended by the following method. As the rubber component, those shown in Table 2 were used.

0.6 kg of rubber component [II] and 1.4 kg of rubber component [III] have an internal volume of 2
With a super mixer of 0 (SMV-20 type manufactured by Kawada Mfg. Co., Ltd.) [(W) / (l) = 0.1 (Kg /)], tank temperature 35 ° C., stirring speed 1800 rpm for 3 minutes Blended.

Furthermore, this blend and triphenyl phosphite
Methacrylic resin [I-1] 2Kg [(W) /
(L) = 0.2 (Kg /)] was blended under the same conditions as above. The polymer attached inside the blender tank was 1 g of a mixture of rubber components [II] and [III] and 2 g of a methacrylic resin [ID], and a blend having a uniform composition was obtained.

The obtained methacrylic resin composition blended with an outer diameter of 40
mmφ screw type extruder (manufactured by Nippon Mfg. Co., Ltd., P
-40-26AB-V type, L / D = 26), melt kneading at a cylinder temperature of 200-260 ° C and a die temperature of 250 ° C to form pellets, and then injection molding under the following conditions. The pieces were evaluated and the results shown in Table 2 were obtained.

Injection molding machine: V-17-65 type screw type automatic injection molding machine manufactured by Japan Steel Works, Ltd. Injection molding conditions: Cylinder temperature 230-260 ° C, mold temperature 55
℃ Test piece size: 110 mm × 110 mm × 2 mm (thickness) 70 mm × 12.5 mm × 6.2 (thickness) The physical properties of the resin compositions in Examples and Comparative Examples were evaluated according to the following methods. .

1. Heat denaturation temperature (HDT ℃) ASTM-D-648 2. MFR 230 ℃, 10Kg and 230 ℃, 3.8Kg ASTM-D-1238 3. Izod impact strength ASTM-D-256 (23 ℃) 4. Surface gloss (Incident angle 60 °) ASTM-D-673-44 5. Total light transmittance, haze value ASTM-D-1003 6. Tensile strength / elongation ASTM-D-638 Reference example is evaluation of [I-1] alone The results are shown.

From this result, the methacrylic resin composition according to the present invention,
It can be seen that it has an excellent surface appearance and has excellent characteristics in impact resistance and heat resistance, mechanical properties, and fluidity processability.

Examples 2, 3, 7, 7A, 7B, Comparative Examples 3-4 and Reference Examples 2-3 The methacrylic resin [I] and rubber component [I] obtained in Example 1 were used.
I] and the rubber component [III] were used in the same manner as in Example 1 except that the amount of each component used during blending and the blending conditions were changed as shown in Tables 3 and 4. Manufactured. The evaluation results are also shown in Tables 3 and 4.

Example 4 Rubber component [II] and rubber component [II] used in Example 1
Each polymer latex containing a predetermined amount of I] was blended with each other, and the rubber component [II] was used in Example 1.
The rubber component [II] and the rubber component [III] were obtained at the same time by the method of recovering from the polymer latex, and the subsequent steps were exactly the same as in Example 1 to obtain a molded product of the methacrylic resin composition. The evaluation results are also shown in Table-3. Thus, even if the rubber components [II] and [III] are blended at the latex stage, a good methacrylic resin composition can be obtained.

Example 5 A pellet-type methacrylic resin composition obtained by the same method as in Example 1 was processed by a single-screw extruder (made by Thermoplastics Co., Ltd., 25 mmφ, vent type).
An extruded plate having a thickness of 3 mm was manufactured and evaluated in the same manner as in Example 1.

Example 6 Instead of the supermixer used in Example 1, a rotary tumbler (OM-25 type manufactured by Oda Seiki Co., Ltd., rotation speed 36 rpm, 3
The same procedure as in Example 1 was carried out except that 0 minutes) was used.

Examples 8 to 10 and Comparative Examples 7 to 8 The particle diameters at the stages up to the first layer (a) of the rubber component [II] and the second layer (d) of the rubber component [III] in Examples and 1A are shown in Tables. As shown in -3, a methacrylic resin composition was produced and evaluated in exactly the same manner as in Example 1 except that the production was performed by changing the amount of the emulsifier at the initial stage of polymerization. The evaluation results are also shown in Table-5.

Example 11 In the production of the third layer (e) of the rubber component [III-1] of Example 1, the types and amounts of the monomers constituting the third layer (e) and the polymerization method are shown below. A methacrylic resin composition was produced and evaluated in exactly the same manner as in Example 1 except that it was changed. The evaluation results are shown in Table-6.

(Wo-1) Raw material MMA (96%) 477.5g EA (4%) 20 g 1,4-butanediol diacrylate (0.5%) 2.5 g TBH 1.5 g (wa-1) Raw material MMA (96%) 4320 g EA (4%) 180 g n-C ₈ SH 13.5 g TBH 6.75 g Raw material (wo-1) / raw material (wa-1) = 1/9 The mixing method was obtained by polymerization (2-2). The monomer mixture of (wo-1) above was continuously added into the container containing the latex over 30 minutes, and the polymerization was further continued for 1 hour. Then, after continuously adding the monomer mixture of (wa-1) over 75 minutes, the polymerization was further continued for 1 hour,
A rubber component [III-1] was obtained in a latex form. The MMA polymerization yield of the monomer polymer was 99.5% or more.

Examples 12 to 15 and Comparative Examples 9 to 11 Types and amounts of monomers constituting the first layer (a) of the rubber component [II] and the second layer (d) of the rubber component [III] in Example 1. The methacrylic resin composition was produced and evaluated in exactly the same manner as in Example 11 except that the values were changed as shown in Table 7. The evaluation results are also shown in Table-7.

From the above results, it can be seen that the methacrylic resin composition according to the present invention has extremely good appearance characteristics (surface gloss, total light transmittance (cloudiness value)) and excellent impact resistance.

Claims (4)

[Claims] 1. A methacrylic resin [I] containing methyl methacrylate as a main constituent unit in an amount of 10 to 90% by weight and a rubber component [II].
And a rubber component [III] in an amount of 90 to 10% by weight, wherein the resin composition comprises (A): the rubber component [II] has 2 to 10 carbon atoms in the alkyl group.
At least one alkyl acrylate ester of 8 69.9
~ 89.9% by weight, styrene or a mixture of styrene and its derivatives 30 to 10% by weight, acrylic acid, methacrylic acid, cinnamic acid, sorbic acid, cyanuric acid, isocyanuric acid, maleic acid, succinic acid, phthalic acid, isophthalic acid and Polymerizable polyfunctional substance (α) which is an ester of at least one acid component selected from the group consisting of trimellitic acid and at least one unsaturated alcohol component of allyl alcohol and methallyl alcohol (α) 0.1 to 5% by weight A first layer obtained by polymerizing 100 parts by weight of a monomer mixture consisting of 0 to 5% by weight of another copolymerizable polyfunctional monomer and 0 to 20% by weight of another copolymerizable monomer. 80% by weight of methyl methacrylate in the presence of (a) and the first layer (a)
~ 100% by weight and 20% by weight of copolymerizable monomer with this ~ 0
A two-layer structure polymer comprising the second layer (b) obtained by polymerizing 10 to 100 parts by weight of a monomer or a mixture thereof, wherein (B): the rubber component [III] is methacrylic A unit containing 40% by weight or more of methyl acid units and 80% by weight or more of the total of methyl methacrylate units and at least one unit selected from alkyl acrylates having an alkyl group having 1 to 8 carbon atoms. In the presence of the first layer (c) and the first layer (c) obtained by polymerizing 1 to 60% by weight of a monomer or a mixture thereof, the alkyl group has 2 to 8 carbon atoms.
At least one of alkyl acrylates of 69.8 ~
89.9% by weight, styrene or a mixture of styrene and its derivative 30 to 10% by weight, the polymerizable polyfunctional substance (α) 0.1
Polymerize 99-40 parts by weight of a monomer mixture consisting of ~ 5% by weight, 0.1-5% by weight of other copolymerizable polyfunctional monomer and 0-20% by weight of other copolymerizable monomer. Obtained by the second layer (d), and a two-layer rubber-like substance consisting of the first layer (c) and the second layer (d)
Monomer consisting of 80 to 100% by weight of methyl methacrylate in the presence of 100 parts by weight, 0 to 5% by weight of a copolymerizable polyfunctional monomer, and 0 to 20% by weight of another copolymerizable monomer. Or a three-layer structure polymer comprising a third layer (e) obtained by polymerizing 10 to 1000 parts by weight of the mixture in an arbitrary ratio within the above range, once or divided into several times. (C): the particle diameter of the rubber component [II] is 0.05 to 0.15 μm in the step of the first layer (a), and the particle diameter of the rubber component [III] is 0.18 to 0.45 in the step of the second layer (d). μm, (D): the weight ratio of the rubber component [II] and the rubber component [III] is [II] / [III] = 1/6 to 6/1, and (E): a methacrylic resin. A method of blending [I], the rubber component [II] and the rubber component [III], mixing the rubber component [II] and the rubber component [III], and then blending with the methacrylic resin [I], or meta. Kuryl resin [I] and rubber component [II], methacrylic resin [I] and rubber component [III]
The impact-resistant methacrylic resin composition, wherein the methacrylic resin composition is obtained by any one of the methods of individually mixing the above and then blending the both. 2. The impact-resistant methacrylic resin composition according to claim 1, wherein the first layer (c) of the rubber component [III] contains 80% by weight or more of methyl methacrylate units. 3. The third layer (e) of the rubber component [III] comprises 80 to 99.9% by weight of methyl methacrylate, 0.1 to 5% by weight of a copolymerizable polyfunctional monomer, and another copolymerizable monomer. First-stage layer (e1) obtained by polymerizing a graft-crosslinkable monomer mixture consisting of 0 to 19.9% by weight of monomer, methyl methacrylate 80 to 100
Consist of 2 layers of the second stage layer (e2) obtained by polymerizing a graft non-crosslinking monomer or monomer mixture consisting of 0 to 20% by weight of other copolymerizable monomer. The composition ratio of the first-stage layer (e1) to the second-stage layer (e2) is (e1) / (e2) = 1/3 to 1/999, and the first layer (c)
And 1 to 100 parts by weight of the first-stage layer (e1) and 9 to 999 parts by weight of the second-stage layer (e2) per 100 parts by weight of the two-layer rubber-like substance consisting of the second layer (d). The impact-resistant methacrylic resin composition according to claim 1 or 2, characterized in that it is a part. 4. A rubber component [I] in a blend of methacrylic resin [I], rubber component [II] and rubber component [III].
I) and the rubber component [III] are copolymers obtained by emulsion polymerization, and these are polymer mixtures recovered at the same time after being blended in a latex state at the polymer latex stage. Item 1 or 2
The impact-resistant methacrylic resin composition according to the item.