JPH04185663A - High-impact high-rigidity aas resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition markedly improved in impact strength without detriment to its weathering resistance and rigidity by combining a multilayer graft copolymer comprising an acrylic ester rubber having a specified degree of grafting with a specified aromatic vinyl/vinyl cyanide copolymer. CONSTITUTION:An AAS resin composition comprising 20-50wt.% particulate multilayer graft copolymer (A) and 80-50wt.% thermoplastic resin (B). The component (A) comprises 30-80wt.% rubbery copolymer particles (a) prepared by forming a crosslinked acrylic ester polymer layer on the surface of a rigid resin particle, 10-30wt.% rubbery elastomer layer (b) comprising 20-80wt.% acrylic ester units, 0.05-5wt.% crosslinking agent, 5-75wt.% aromatic vinyl units and 5-50wt.% vinyl cyanide units and formed on the surface of component (a) by graft polymerization, and 10-40wt.% resin layer (c) comprising 30-90wt.% aromatic vinyl units and 10-50wt.% vinyl cyanide units and formed on the surface of component (b) and having a degree of grafting of 35-70%. The component (B) is a copolymer comprising 20-40wt.% vinyl cyanide units and 80-60wt.% aromatic vinyl units and having a weight-average molecular weight (Mw) of 150000-250000.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides an A
Regarding AS resin.

More specifically, the present invention relates to an AAS resin composition made of acrylic ester rubber that has weather resistance, impact resistance, rigidity, and excellent appearance.

(Conventional technology) Among plastics, polycarbonate and methacrylic resin have relatively strong weather resistance, but these resins have poor mechanical strength, processability, price, etc.
The scope of application is narrowed because the balance is not necessarily well-balanced.

On the other hand, ABS resin is widely used in fields such as automobiles and electrical parts due to its excellent impact resistance, excellent balance of mechanical properties, easy molding process, and relatively low price. There is. However, on the other hand, since ABS resin uses polybutadiene as one of its constituent components, it has a drawback in weather resistance, making it unsuitable for outdoor use.The weather resistance of ABS resin has been significantly improved. The advent of plastics has been a desire for many years.

From this background, it has been considered to use rubbers other than diene-based rubbers, and various proposals have been made to use saturated rubbers. AAS resin, which is an acrylic acid ester polymer, is one example of this. Although this method improves weather resistance, it also causes a decrease in impact resistance and the appearance of molded products, which poses a practical problem. It was what was left behind.

For example, Japanese Patent Publication No. 55-27576 discloses a method for producing a multi-stage, sequential structure polymer consisting of a hard polymer in the first stage, a rubber-like elastic polymer in the intermediate stage, and a hard polymer in the third stage. However, in this method, the first
The use of a grafting agent and a crosslinking agent in the step provides a low haze impact resistant resin composition.

However, this resin composition is difficult to use! Its strength is low and its practical range of use is limited.

Furthermore, Japanese Patent Publication No. 59-36645 discloses a method for producing a multi-stage polymer consisting of methacrylic acid ester and acrylic acid ester, but the difference w1! It was insufficient in terms of

Furthermore, Japanese Patent Application No. 1-320435 discloses a multilayer graft copolymer made of acrylic ester rubber and a copolymer of aromatic vinyl-vinyl cyanide, but it has excellent weather resistance. However, its impact strength is not sufficient, limiting its industrial use.

As a result of extensive research into improving the impact strength of AAS resins, the present invention has developed a multilayer graft copolymer made of acrylic ester rubber having a specific graft ratio, a specific molecular weight,
By combining an aromatic vinyl-vinyl cyanide copolymer with a molecular weight distribution and copolymerization composition, the impact strength is increased while maintaining weather resistance and rigidity. It became possible to improve the

(Intelligence to be Solved by the Invention 8) In view of the current situation, the present invention provides an AAS resin that does not have the above-mentioned problems, that is, has weather resistance, impact resistance, rigidity, and excellent appearance. ``The purpose is to provide a composition.

(Means for Solving the Problems) That is, the present invention provides a particulate multilayer graft copolymer A2
0 to 50% by weight of thermoplastic resin 8 and 80 to 50% by weight of thermoplastic resin 8, the particulate multilayer graft copolymer A comprises (a) an acrylic ester-based resin on the surface of the hard resin particles; 30 to 80% of rubbery copolymer particles having a crosslinked polymer layer provided thereon at a weight ratio of 5:95 to 40:60, and this rubbery copolymer. (b) 20 to 80% by weight of acrylic ester units, 0.05 to 5% by weight of crosslinking agent, and 5 to 5% of aromatic vinyl units were sequentially provided on the surface of the combined particles by graft polymerization.
(c) 10-30% by weight of a rubber cane elastomer layer comprising 75% by weight of vinyl cyanide units and 5-50% by weight of vinyl cyanide units; and (c) 30-90% by weight of aromatic vinyl units and 1% by weight of vinyl cyanide units.
The average particle diameter is 0.2 to 0.8 μm, and the grafting rate is composed of 10 to 40% by weight of a resin layer containing 0 to 50% by weight and 20% by weight or less of acrylic acid ester units optionally introduced. is a multilayer graft copolymer having 35 to 70%, and the thermoplastic resin B contains 20 to 40% by weight of vinyl cyanide units, 80 to 60% by weight of aromatic vinyl units, and one type copolymerizable with these. A copolymer consisting of 0 to 30% by weight of the above monomer units, the weight average molecular weight (Mw) of this copolymer is 150°000 to 250,000, and the weight average molecular weight (Mw) and number Average molecular weight (Mn)
The present invention provides a high impact and high rigidity AAS resin composition having a ratio Mw/Mn of 1.5 to 2.5.

The present invention will be explained in detail below.

The AAS resin composition of the present invention provides surprising advantages by combining a specific particulate multilayer graft copolymer A and a specific thermoplastic resin B.

First, particulate multilayer graft copolymer A is (a) rubber-like copolymer particles formed by providing an acrylic acid ester crosslinked polymer layer (second layer) on the surface of hard resin particles (first layer). and (c) a rubbery elastic layer (third layer) and (c) which are sequentially provided on the surface of the rubbery copolymer particles by graft polymerization.
) A resin layer (fourth layer), and each layer has an important function.

The innermost hard resin (first layer) is important both for increasing the elastic modulus of the rubbery copolymer and for determining the final particle size of the multilayer graft copolymer during seed polymerization. . In the rubber-like copolymer particles composed of the first layer and the second layer, the content ratio of the first hard resin layer and the second acrylic acid ester crosslinked polymer layer is 5:95 by weight. It is necessary that the ratio be in the range of ~40:60.

If the content of the hard resin layer is less than the above range, the effect of increasing the elastic modulus will not be sufficient, and if it is more than the above range, the elastic modulus of the rubbery copolymer will increase too much and the impact strength will decrease.

In addition, the hard resin may be one obtained by a normal emulsion polymerization method and is not particularly limited. For example, methacrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, and propyl methacrylate; Aromatic vinyl compounds; examples include vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, which give polymers with a high glass transition point (Tg). These seven polymers may be used singly or in combination of two or more. For example, methyl acrylate, ethyl acrylate, acrylic It may also be used in combination with a heptamine which provides a low Tg polymer such as propyl acid or butyl acrylate.

On the other hand, the second acrylic ester crosslinked polymer layer is
This layer is provided to impart impact strength, and examples of acrylic esters include acrylic alkyl esters in which the alkyl group has 1 to 10 carbon atoms, such as butyl acrylate, ethyl acrylate, and 2-ethylhexyl acrylate; Examples include aromatic esters of acrylic acid such as benzyl acid. These acrylic esters may be used alone or in combination of two or more, and if desired, other copolymerizable vinyl threads may be used, such as styrene, acrylonitrile, methacrylonitrile, methacryl. It may be used in combination with methyl acid, methacrylic acid, acrylic acid, etc.

The crosslinking agent used in the acrylic ester crosslinked polymer of the second layer is a crosslinking monomer having at least two C--C bonds in the molecule, and is copolymerizable with the acrylic ester. Examples of such substances include unsaturated acid esters of polyols such as ethylene glycol dimethacrylate; unsaturated alcohol esters of polybasic acids such as triallyl cyanurate and triallyl isocyanurate; and divinyl compounds such as divinylhenzene. Can be mentioned.

Further, the content of the rubbery copolymer particles (first layer, second layer) in the multilayer graft copolymer particles A needs to be in the range of 30 to 80% by weight. If this amount deviates from the above range, the effect of imparting impact strength will not be sufficiently exerted.

The third layer made of a rubber-like elastic material layer is an intermediate layer provided between the rubber-like polymer particles made of the first layer and the second layer and the fourth resin layer, and It has the effect of improving the adhesion between the copolymer and the fourth layer. This third rubber-like elastic layer has 20 to 20 acrylic acid ester units.
80% by weight, 5 to 75% by weight of aromatic vinyl compound units, and 5 to 50% by weight of vinyl cyanide units. If the content of acrylic ester units is less than 20% by weight, the adhesion with the second layer of acrylic ester crosslinked polymer layer will be poor and the impact strength will be insufficient.
If it exceeds % by weight, the adhesion with the fourth resin layer tends to deteriorate and the impact strength tends to decrease.

The third rubber-like elastic material layer is composed of the first layer and the second layer, which are made of a monomer mixture of an acrylic ester, an aromatic vinyl compound, a vinyl cyanide compound, and a crosslinking agent. It can be formed by graft polymerizing rubbery copolymer particles.

At this time, as the acrylic ester, those exemplified in the description of the acrylic ester crosslinked polymer layer of the second layer can be used. These acrylic esters may be used alone or in combination of two or more. Examples of aromatic vinyl compounds include styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, and halogenated vinyl compounds. Examples of vinyl cyanide compounds include styrene, which may be used alone or in combination of two or more. Examples of vinyl cyanide compounds include acrylonitrile and methacrylonitrile. They may be used, or two or more types may be used in combination.

On the other hand, as the crosslinking agent, those exemplified in the description of the second layer can be used, and the amount used is usually selected in the range of 0.05 to 5% by weight based on the weight of the monomer mixture. . Further, the content of this third layer in the multilayer graft copolymer particles A needs to be in the range of 10 to 30% by weight.

The fourth resin layer in the multilayer graft copolymer particle 1 is a layer provided to improve compatibility with the thermoplastic resin B, and contains 30 to 90 aromatic vinyl compound units.
It is necessary to contain from 10 to 50% by weight of vinyl cyanide units and up to 20% by weight of optionally introduced acrylic ester units. When the content of the acrylic ester unit exceeds 20% by weight, thermoplastic resin B
The compatibility with the material deteriorates, and the impact strength decreases.

The fourth resin layer is made of a monomer mixture of an aromatic vinyl compound, a vinyl cyanide compound, and an acrylic ester that is optionally used, and is made of a rubber-like material on which the third rubber-like elastic layer is provided. It can be formed by graft polymerizing polymer particles. At this time, as the aromatic vinyl compound and the vinyl cyanide compound, those exemplified in the explanation of the rubber-like elastic layer of the third layer can be used, and as the acrylic ester, the compounds of the second layer can be used. Those exemplified in the explanation of the acrylic ester crosslinked polymer layer can be used. Each of these monomers may be used alone or in combination of two or more.

Furthermore, this fourth layer in the multilayer graft copolymer particles A
It is necessary that the content of the layer is in the range 10-40% by weight.

The multilayer graft copolymer particles A in the composition of the present invention are:
The average particle diameter is 0. It is necessary that the thickness be in the range of 2 to 0.8 μm. If the average particle diameter is less than 0°2 μm, the resulting molded product will have excellent surface gloss, but will not be as good! !
The strength is low, and if it exceeds 0.8 μm, the surface gloss will be poor although the impact 1i strength will be high.

In addition, in order to improve the impact strength, the graft ratio should be 35~
It is essential that it be within the range of 70%. If it is less than 35%, the compatibility with thermoplastic resin B decreases and a state of phase separation occurs, resulting in poor impact strength. If it exceeds 70%, the compatibility improves and the two-phase system becomes impact strength decreases.

Here, the graft ratio is calculated from the solvent-insoluble fraction obtained by extracting the multilayer graft copolymer using acetone using the following formula.

The above rubber % refers to the content of acrylic ester units in the second to fourth phases in the multilayer graft copolymer A.

The method for producing this multilayer graft copolymer particle A is as follows:
Emulsion polymerization, in which monomers are polymerized in the presence of emulsifiers, polymerization initiators, and chain transfer agents; in particular, seed polymerization, in which monomers are polymerized in the presence of a hard resin, which forms the innermost layer, under conditions that control new formation. Legal etc. are preferably used.

Examples of the emulsifier include -)J) having 2 to 22 carbon atoms;
Ltponic acids; anionic emulsifiers such as sulfonates of alcohols or alkylphenols having 6 to 22 carbon atoms; nonionic emulsifiers such as alkylene oxide added to aliphatic amines or amides; cationic emulsifiers such as quaternary ammonium salt-containing compounds, etc. can be mentioned.

Examples of polymerization initiators include water-soluble peroxides such as hydrogen peroxide and alkali metal salts and ammonium salts of persulfuric acid; oil-soluble organic peroxides such as benzoyl peroxide and cumene hydroperoxide; Azo compounds such as nitrile are used alone or in combination. Further, as a redox catalyst, a mixture of a reducing agent and a peroxide, for example, a reducing agent such as hydrazine, bis sulfide, thiosulfide, alkali metal salts of hydrosulfides, a soluble oxidizable sulfoxyl compound, and the above i8 oxide can be used. Mixtures can be used.

Furthermore, examples of the chain transfer agent include alkyl mercaptans such as t-dodecyl mercaptan, toluene, xylene, chloroform, and halogenated hydrocarbons.

The appropriate polymerization temperature for forming the polymer and/or copolymer in each polymerization step is 30 to 12
0°C, preferably in the range of 50-100'C.

Regarding the method of adding the monomer, it may be added in one batch, but it is advantageous to add it in several parts or to add it continuously. In this case, the polymerization reaction can be easily suppressed, and overheating and coagulation can be prevented.

In addition, in order to form the third layer of rubber-like elastic material layer and the 43i-th resin layer, after completing the polymerization reaction to form the second layer of acrylic acid ester crosslinked polymer layer,
A seven-termer for forming a rubber-like elastic column layer and a seven-termer for forming a resin layer may be added and polymerized sequentially, or the polymerization reaction for forming the acrylic acid ester crosslinked polymer layer may be carried out in a complete stage. The aromatic vinyl compound and vinyl cyanide compound may be added to form the rubber-like elastic layer and the resin layer while leaving unreacted monomers.

Furthermore, as a method for suppressing the particle size of the multilayer graft copolymer particles, - part of the latex (seed latex) obtained by polymerization of the innermost hard resin layer is taken out, and ion-exchanged water, an emulsifier, and a monomer are added. When continuing seed polymerization, a method can be used to control the particle size of the multilayer graft copolymer particles by adjusting the amount of the seed latex taken out and suppressing the number of particles of the seed latex.

Opposition! The method of controlling the grafting rate, which is important for imparting strength, is
This can be carried out by adjusting the type and amount of initiator, polymerization temperature, rubber percentage, amount of chain transfer agent, and amount of emulsifier.

The multilayer graft copolymer A having a special structure obtained by such a polymerization method can be obtained as a particulate solid by performing treatments such as salting out, washing, and drying from the polymer latex state by known methods. It will be done.

On the other hand, the thermoplastic resin B consists of vinyl cyanide units, aromatic vinyl units, and one or more 1,000-mer units copolymerizable with these units. Here, vinyl cyanide, which is an essential component, includes acrylonitrile, methacrylonitrile, etc., and acrylonitrile is particularly preferred, but it may also be a copolymer containing methacrylonitrile, which is another essential component. Aromatic vinyls include styrene, α-methylstyrene, paramethylstyrene, p
-chlorostyrene, p-bromostyrene, 2.4.5-
Tribromostyrene, etc., and styrene is most preferred, but a copolymer of styrene and other aromatic vinyls mentioned above may also be used.

As a component of the thermoplastic resin B, one or more monomer components copolymerizable with vinyl cyanide and aromatic vinyl may be introduced to further improve blendability with the zero-particulate layered graft copolymer A; If it is necessary to increase the melt viscosity during blending, an acrylic ester consisting of an alkyl group having 1 to 8 carbon atoms can be used. Moreover, when it is necessary to improve the heat resistance of the molded article, monomers such as acrylic acid, methacrylic acid, maleic anhydride, and N-substituted maleimide are selected.

The vinyl cyanide unit in the composition of thermoplastic resin B is
20 to 40% by weight, 80 to 60% by weight of aromatic vinyl units, and 0 of one or more monomer units copolymerizable with these units.
It is necessary that the amount is in the range of ~30% by weight; outside this range, the compatibility with the particulate multilayer graft copolymer A decreases, and the impact strength of the molded article decreases.

Here, the weight average molecular weight (MW) of thermoplastic resin B is 1
50,000 to 250.000, and the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) M w /
It is essential for Mn to be in the range of 1.5 to 2.5 in order to improve impact strength.

When Mw is less than 150.000, the impact strength is low and 25
When it exceeds 0.000, fluidity decreases. Also, M w
When /Mn is less than 1.5, the fluidity is low, and when it exceeds 2.5, the impact strength is decreased.

This thermoplastic resin B is produced by a conventional solution polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization method. The weight average molecular weight can be controlled by the polymerization temperature, the type and amount of the initiator, and the amount of the chain transfer agent. Regarding the control of Mw/Mn, which is a measure of molecular weight distribution, a narrow distribution can be achieved, for example, by performing polymerization at a uniform temperature in a complete mixing reactor in continuous solution polymerization. - On the other hand, in order to create a wide distribution, suspension polymerization can be employed, or even in continuous solution polymerization, a starter tube type reactor can be used for polymerization with a wide temperature flow profile. Alternatively, thermoplastic resins B having different narrow distributions of Mw may be mixed to obtain a target distribution.

Regarding the quantitative ratio of the multilayer graft copolymer A and the thermoplastic resin B constituting the AAS resin composition of the present invention, A is 2.
It is essential that B be 0 to 50% by weight and B be 80 to 50% by weight. Outside this range, impact strength and rigidity cannot be balanced.

In addition to the multilayer graft copolymer A and the thermoplastic resin B, it may also contain a thermoplastic resin that can make A and B compatible to the extent that the impact strength is not reduced. For example, a methacrylic resin , vinyl cyanide-aromatic vinyl-acrylic acid ester copolymer, vinyl cyanide-aromatic vinyl-N
! Examples include dilated mamaleimide copolymer polycarbonate resins, vinyl chloride resins, and the like.

The resin composition of the present invention comprises particulate multilayer graft copolymer A
and thermoplastic resin B in a commercially available single-screw extruder or twin-screw extruder. etc. can be added as necessary.

By injection molding or extrusion molding the composition of the present invention thus obtained, a molded article with excellent weather resistance, impact resistance, rigidity, and appearance can be obtained.

(Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto in any way.

The methods for measuring each physical property used in the present invention are as follows.

■ Copolymer composition: At each stage of polymerization, the residual monomer of each component was measured by gas chromatography, and the produced polymer composition was calculated from the amount of feed monomer.

■ Rubber particle size: The latex particle size determined by electron microscopy and the wavelength 550n- of the diluted latex solution (50 ppm solid content).
A calibration curve was prepared for the relationship between the absorbance and the absorbance of each latex.

■ Grafting ratio of multilayer graft copolymer: The sample was immersed in 25 times the amount of acetone, shaken for 2 hours, and the supernatant was removed using a centrifugal separator. This procedure was repeated three times, and then the sample was dried. The percentage of the weight ratio of the weight to the initial sample was defined as the acetone insoluble content (%), and the grafting rate was calculated from the following formula.

In addition, the above-mentioned rubber % means that in the multilayer graft copolymer A,
It refers to the percentage content of acrylic ester units in the second to fourth layers.

■ Tensile strength, tensile elongation: Measured according to ASTM-D63 B ■ Bending strength, bending modulus: ASTM-D790! 1! Measured using a method based on

■ Ident impact strength: (V) ν measured according to ASTM-D256
H, 1/4” test piece).

(2) Glossiness: Specular glossiness was determined based on ASTM-D523-62T at an incident angle of 60 degrees.

(2) Melt flow rate (MFR): An index of fluidity, measured in accordance with ASTM-D 123B. It was determined from the amount of extrusion per 10 minutes (g/10 m1n) under the conditions of a load of 10 kg and an i temperature resistance of 220'C.

■ Weather resistance: Suga test I! Manufactured Dupanel Light Control Weather
A weather resistance acceleration test was carried out using a meter (DPWI-5 type) in a cycle of irradiation at 60°C and humidification at 40°C. The percentage of the ratio of the Izot after 20 days of irradiation to the initial Izot was defined as the retention rate of the Izont impact strength, and was used as an evaluation of weather resistance.

[Phase] Molecular weight, molecular weight distribution (Mw1Mw/Mn): Gel permeability chromatograph HLC-8020 (manufactured by Tosoh) as a measuring device and T (manufactured by Tosoh) as a column
Using SK-Gel-GMHXL and using tetrahydrofuran (THF) as the mobile phase! ! A gel vermien chromatography analysis (GPC analysis) of quasi-polystyrene was performed, and a calibration curve was created using 10 mg of the material.
was dissolved in THFlod and subjected to the above GPC analysis, and Mw and Mw/Mn were calculated using the above calibration curve.

Example 1 ■ Production of multilayer graft copolymer particles A: (a) Preparation of the innermost hard resin layer (first layer) (i) 248.3 parts by weight of ion-exchanged water was placed in the seed first stage polymerization reactor. , 0.05 parts by weight of sodium dihexyl sulfosuccinate was charged, and after thorough nitrogen substitution with stirring, the temperature was raised to 75°C. After adding 0.02 parts by weight of ammonium persulfate to this reactor, 8 parts by weight of methyl methacrylate,
A mixture of 2 parts by weight of butyl acrylate was added continuously over 50 minutes.

After the addition, 0.01 part by weight of ammonium persulfate was further added, and the reaction was continued at 75°C for 45 minutes.

The polymerization rate is 99%, and the particle size of the latex is 0°17
It was μm.

(ii) Seed second stage polymerization Next, 1/4 of this latex (2.5 parts by weight in terms of solid content) was taken out, and 186.231 parts of ion-exchanged water was added.
0.03 parts by weight of sodium dihexyl sulfosuccinate were charged into a reactor, and after thorough nitrogen substitution with stirring, the temperature was raised to 75°C. After adding 0.02 parts by weight of ammonium persulfate to this reactor, 6.0 parts by weight of methyl methacrylate and 1.5 parts by weight of butyl acrylate were added.
parts by weight were added continuously over a period of 50 minutes. After the addition was completed, the reaction was continued at 75°C for 45 minutes to complete the reaction. The polymerization rate was 98%, and the particle size of the latex was 0.28 μm.

(b) Preparation of acrylic acid ester crosslinked polymer layer (second layer).

In the presence of the latex containing the hard resin particles obtained in (a) above, ammonium persulfate 0.01 weight Is and sodium dihexylsulfosuccinate 0.05 parts by weight were added, and then 63 parts by weight of butyl acrylate and crosslinking were carried out. A mixture with 0.6 parts by weight of triallyl isocyanurate as a reagent was continuously added at 70° C. over 80 minutes. After the addition was completed, the reaction was continued for an additional 200 minutes at 70°C. The polymerization rate through the first and second layers was 85%, and the particle size was 0.41μ.
It was m.

(c) Preparation of rubber-like elastic layer (third layer).

After completing the step (b), unreacted butyl acrylate 11
After adding 0.045 parts by weight of ammonium persulfate and 0.45 parts by weight of sodium dihexyl sulfosuccinate in the presence of 0.09 parts by weight of triallylisocyanurate, 3.8 parts by weight of acrylonitrile and 11.4 parts by weight of styrene.
parts by weight and 1-dodecylmercaptan 0. ．． 0.0125 parts by weight were added continuously at 75° C. over a period of 90 minutes. The polymerization rate was 93%. In addition, the amount of residual monomer in the latex was measured by gas chromatography, and the copolymerization composition ratio of the third layer was calculated. As a result, the weight ratio of acrylonitrile units/styrene units/butyl acrylate units was IO/43/47. Met.

(d) Preparation of resin layer (fourth layer).

In the presence of the latex of (c), acrylonitrile 2.
A mixture consisting of 95 parts by weight, 8.86 parts by weight of styrene and 0.01 parts by weight of dodecyl mercaptan was heated at 75°C.
The mixture was added continuously over a period of 70 minutes. Further, the reaction was continued at 75°C for 1.5 hours to complete the polymerization. The polymerization rate was 97%, and the particle size was 0.56 μm. In addition, the amount of residual monomer in the latex was measured by gas chromatography, and the copolymerization composition ratio of 4N was calculated. As a result, the weight ratio of acrylonitrile units/styrene units/butyl acrylate units was 24/65/11. Ta.

The latex thus obtained was salted out with aluminum sulfate and dried according to a conventional method to obtain multilayer graft copolymer particles A-1. The grafting rate of A-1 was 47.2%.

■ Production of thermoplastic resin B: 21.5 parts by weight of acrylonitrile, 49.5 parts by weight of styrene, 29 parts by weight of ethylbenzene, and t as an initiator.
-Butylperoxyisopropyl carbonate 300p
The pm mixture is 1.94! Capacity 2./hr speed. IE
The polymerization solution was continuously supplied to a complete mixing type reactor and polymerized at 130°C, and was continuously led to a vented extruder to remove unreacted monomers and solvent under the conditions of 260°C and 240 Torr. was removed, and the polymer was continuously cooled and solidified to obtain particulate thermoplastic resin B-1. It consisted of 29% by weight of acrylonitrile units and 71% by weight of styrene units, and GPC analysis showed that the Mw was 165,800 and the Mw/Mn was 1.86.

■ Preparation and evaluation of composition: Multilayer graft copolymer A-1 and thermoplastic resin B-1
were mixed for 20 minutes in a Hennel mixer at a weight ratio of 35/65, and then pelletized at 260 °C using a 30 m vented twin screw extruder (manufactured by Nakayo Kikai ■, type A). carried out.

The resulting pellets were processed into an in-line screw injection molding machine (
Molding temperature 26 using Toshiba Machine ■ Model 15-753)
Predetermined test pieces were prepared under the conditions of 0°C and mold temperature of 60°C, and physical properties were measured. The results are shown in Table 2. Further, the composition, graft ratio, and particle size of the multilayer graft copolymer A-1 are shown in Table 1.

According to Tables 1 and 2, it can be seen that the resin composition obtained according to the present invention has weather resistance, impact resistance, rigidity, and excellent appearance. Comparative Example 1 ■ Multilayer graft copolymer Production of particles = (a) Production of the innermost hard resin layer (first layer).

It was carried out in the same manner as in Example 1 (a).

(b) Preparation of acrylic acid ester crosslinked polymer layer (second layer).

In the presence of the latex obtained in the above (a), after adding 0.13 parts by weight of ammonium persulfate and 0.05 parts by weight of sodium dihexylsulfosuccinate, 6 parts of butyl acrylate was added.
A mixture of 3 parts by weight and 0.6 parts by weight of triallylisocyanurate as a crosslinking agent was added continuously at 80°C over 80 minutes.

After the addition was completed, the reaction was continued for an additional 90 minutes at 80°C.

The polymerization rate through the first and second layers was 99.5%, and the particle size was 0.41 μm.

(c) Preparation of resin layer.

In the presence of the latex obtained in the above (b), 0.045 parts by weight of ammonium persulfate and 0.45 parts by weight of sodium dihexylsulfosuccinate were added, followed by 6.75 parts by weight of acrylonitrile, 20.25 parts by weight of styrene, and t. −
A mixture consisting of 0.0225 parts by weight of dodecyl mercaptan was added continuously over a period of 160 minutes at 75°C. Further, the reaction was continued at 85"C for 1 hour to complete the polymerization.

The polymerization rate was 98%, and the particle size was 0.55 μm.

Further, the amount of residual monomer in the latex was measured by gas chromatography and the copolymerization composition ratio of the resin layer was calculated, and the weight ratio of acrylonitrile units/styrene units/butyl acrylate units was 25/7510.

The latex thus obtained was treated in the same manner as in Example 1 and evaluated. The grafting rate of this multilayer graft copolymer was 31.3%.

The results are shown in Table 1.

(2) Preparation and evaluation of composition: Pellets were obtained in the same manner as in Example 1, except that the multilayer graft copolymer particles obtained in (1) above were used, and then test pieces were prepared and physical properties were evaluated. The results are shown in Table 2.

From Tables 1 and 2, it can be seen that the multilayer graft copolymer particles without a rubber-like elastic layer have a low graft ratio and low mechanical strength.

Examples 1 to 3 and Comparative Example 2.3 (Effect of particle size of multilayer graft copolymer) In Example 1, the hardness of the innermost layer was determined by the latex obtained by polymerization of the resin (first layer) node. By continuing the sword polymerization while decreasing the amount of sampled, the final particle size was adjusted to 0.56-0.
It was suppressed to 85 μm. In addition, by increasing the amount of sodium dihequinyl sulfosuccinate in the first stage of the seed and continuing seed polymerization, the final particle size was increased from 0.56 to 0°16.
It was suppressed down to μm.

The latex obtained by such munication was treated in the same manner as in Example 1 to obtain multilayer graft copolymer particles, and then a composition was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 3.

According to Table 3, the particle size of the multilayer graft copolymer is 0.
Although the gloss of the resulting composition is excellent when the diameter is smaller than 2 μm, the Izot impact strength is low;
It can be seen that when the diameter exceeds .mu.m, the Izot impact strength is excellent, but the gloss is low.

Table 3: Comparative Example 4 In Example 1, acrylic acid ester crosslinker (g) in the production of multilayer graft copolymer particles. The combined layer (second layer) was produced in the same manner as in Example 1, except that triallylisocyanurate was not used as a crosslinking agent.

The results are shown in Table 4.

From Table 4, it can be seen that when triallylisocyanurate is not used, the mechanical properties of the resulting composition are significantly inferior to those of Example 1.

Comparative Example 5 In Example], in the production of the acrylic acid ester crosslinked polymer layer (second layer) in the production of multilayer graft copolymer particles, instead of triallylisocyanurate as a crosslinking agent, The same procedure as in Example 1 was carried out except that 0.6 parts by weight of allyl methacrylate as a grafting agent was used. The results are shown in Table 4.

Table 4 shows that when the grafting agent allyl methacrylate is used instead of the crosslinking agent triallyl isocyanurate, the resulting composition has lower mechanical strength than Example 1.

Example 1.4 and Comparative Example 6.7 (Effect of graft ratio of multilayer graft copolymer) Example 1
In the production of a multilayer graft copolymer, in order to obtain a grafting ratio smaller than that of A-1, the third layer,
During the polymerization of the fourth layer, t-dodecyl mercaptan, which is a chain transfer agent, was increased. In addition, in order to obtain a grafting ratio higher than that of A-1, t-dodecyl mercaptan should be reduced during polymerization of the third and fourth layers, or butyl acrylate in the second layer should be reduced. , acrylonitrile and styrene were increased accordingly. - As a result, the grafting rate could be controlled to 33-75%.

The latex thus obtained was treated in the same manner as in Example 1 to obtain a multilayer graft copolymer, and then a composition with thermoplastic resin B-1 was prepared in the same manner as in Example 1 and evaluated. did. The results are shown in Table 5.

According to Table 5, it can be seen that impact strength is low when the graft ratio is outside the range of 35 to 70.

Table 5 Gooft's belly A's Gooft and Example 1.
2 and Comparative Example 8.9 (Effect of copolymerization composition of thermoplastic resin B) In the production of thermoplastic resin B-1 of Example 1, the molecular weight and molecular weight distribution are the same as B-1, and the copolymerization In order to obtain thermoplastic resin B having a different composition, the monomer charge composition was changed. As a result, the acrylonitrile content could be controlled to 17-43%.

A composition of thermoplastic resin B and multilayer graft copolymer A-1 thus obtained was prepared in the same manner as in Example 1,
evaluated. The results are shown in Table 6.

According to Table 6, it can be seen that the impact strength is low outside the range of 20 to 40% by weight of acrylonitrile units and 80 to 60% by weight of aromatic vinyl units.

Example 1. ．． 3.4 Comparative Example 10.11.12 (Effect of Mw of Thermoplastic Resin B) In the production of thermoplastic resin B-1 of Example 1, B-1
In order to obtain a thermoplastic resin B having the same copolymerization composition and molecular weight distribution but different molecular weight, t-dodecyl mercaptan is added as a chain transfer side to lower the molecular weight, or the polymerization temperature is lowered to increase the molecular weight. I let it happen. As a result, it was possible to control Mw from 43°000 to 270,000.

A composition of thermoplastic resin B and multilayer graft copolymer A-1 thus obtained was prepared in the same manner as in Example 1,
evaluated. The results are shown in Table 7.

According to Table 7, it can be seen that when Mw is less than 150,000, the impact strength is low, and when it exceeds 250,000, the fluidity is decreased.

Example 1.5 Comparative Example 13.14.15 (Effect of molecular weight distribution of thermoplastic resin B) Thermoplastic resin B-1 of Example 1
In the production of B-1, thermoplastic resin B-3 is thermally extracted with a mixed solvent of methyl ethyl ketone and methanol in order to obtain thermoplastic resin B, which has the same copolymer composition and Mw as B-1 but a different molecular weight distribution. By removing low molecular weight components and narrowing the molecular weight distribution, or by removing high molecular weight b-
5 or B-4 and low molecular weight b-3 were mixed to widen the molecular weight distribution. As a result, Mw/Mn is 1.4 to 3.3.
I was able to control up to.

A composition of thermoplastic resin B and multilayer graft copolymer A-1 thus obtained was prepared in the same manner as in Example 1,
evaluated. The results are shown in Table 8.

According to Table 8, it can be seen that when M W / M n is less than 1.5, the fluidity is low, and when it exceeds 2.5, the impact strength is reduced.

Comparative Example 16 ■ Manufacture of ABS resin: 70 parts by weight of polybutadiene rubber, 0.05 parts by weight of dihequinyl sulfosuccinate, 0.0 parts by weight of ammonium pergate.
An aqueous emulsion liquid consisting of 2.0 parts by weight of 0.02M and 2.0 parts by weight of ion-exchanged water was charged into a reactor, and the internal temperature was controlled at 75°C. Next, 30 parts by weight of a monomer mixture of 25% by weight of acrylonitrile and 75% by weight of styrene was added continuously over a period of 2 hours, and after the addition was completed, polymerization was continued for another 2 hours to obtain a graft copolymer. A polymer was obtained. The reaction rate is 98
%Met. The weight ratio of acrylonitrile units to styrene units in this polymer was 25/75. Furthermore, according to electron microscopic observation, the average rubber particle diameter was 0. It was 4 μm.

■ Preparation and evaluation of composition: Next, the graft copolymer and thermoplastic resin B-1
were mixed in a weight ratio of 35/65 to obtain a pellet in the same manner as in Example 1, and then a test piece was prepared and its physical properties were evaluated. The results are listed in Table 9.

According to Table 9, it can be seen that ABS resin has poor weather resistance.

(Effects of the Invention) As is clear from the above, the present invention is a novel AAS resin that has improved weather resistance compared to ABS resin, and has excellent appearance, rigidity, and excellent impact resistance.
The purpose of the present invention is to provide a series of resins.

This resin can be used unpainted for many years in a wide range of applications including automobile parts and electrical parts, especially for outdoor applications where conventionally painted products such as metal materials or ABS resin were used, and it will play a role in these industries. It has a big role to play.

Claims (1)

[Scope of Claims] A resin composition comprising 20 to 50% by weight of a particulate multilayer graft copolymer A and 80 to 50% by weight of a thermoplastic resin B, wherein the particulate multilayer graft copolymer A comprises (a ) An acrylic acid ester crosslinked polymer layer is formed on the surface of the hard resin particles, and the weight ratio of the particles to the polymer layer is 5:95 to 40:60.
30 to 80 rubbery copolymer particles arranged so that
(b) 20-80% by weight of acrylic ester units, 0.05-5% by weight of crosslinking agent, and 5-5% by weight of aromatic vinyl units, which were sequentially provided on the surface of the rubbery copolymer particles by graft polymerization. 75% by weight and 5-5 vinyl cyanide units
(c) 30-90% by weight of aromatic vinyl units, 10-50% by weight of vinyl cyanide units, and 20% by weight of acrylic acid ester units optionally introduced. Resin layer 10 containing % by weight or less
~40% by weight and an average particle diameter of 0.2~0.
8 μm and a graft ratio of 35 to 70%, the thermoplastic resin B contains 20 to 40% by weight of vinyl cyanide units, 80 to 60% by weight of aromatic vinyl units, A copolymer consisting of 0 to 30% by weight of one or more monomer units copolymerizable with these, the weight average molecular weight (Mw) of this copolymer is 150,000 to 250,000, and the weight A high-impact, high-rigidity AAS resin composition, characterized in that the ratio Mw/Mn of average molecular weight (Mw) to number average molecular weight (Mn) is 1.5 to 2.5.