JP2627809B2 - ABS resin composition for painting - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resin composition which gives good appearance performance when coated.

[Conventional technology]

A resin composition obtained by graft copolymerizing a vinyl cyanide compound and an aromatic vinyl compound on a rubbery polymer is, for example,
As an ABS resin, it is widely used because of its good workability and mechanical strength. When a diene compound polymer is used as the rubbery polymer in this composition, it may be used after being coated because the weather resistance is not always sufficient.
In addition, it is not rare to apply painting for design reasons.

When applying paint to a resin, depending on the type of resin used, the type of paint or thinner, the coating conditions, etc., minute cracks may occur on the surface of the resin molded product when coming into contact with the paint or thinner, and the paint may be sucked in or sucked in If not, the sharpness of the coated surface may be reduced. Such a resin-painted product having poor appearance impairs the commercial value of the product as a whole when used in parallel with a metal-coated product such as interior and exterior parts of automobiles and motorcycles.

It is said that the appearance defect phenomenon accompanying the resin coating is caused by residual strain when the resin is molded, and can be solved by annealing the molded product before coating. However, annealing a large molded product requires large-scale equipment, and the increase in the number of working steps causes a significant decrease in productivity. In addition, a paint or a thinner having a low penetrative power to a resin can be used, but it is generally not preferable because the adhesion strength of the coating film is inferior.

JP-A-54-94547 discloses a technique for solving the problem of poor appearance of a coated article by improving a resin composition. According to this technique, the content of a vinyl cyanide compound unit in a copolymer consisting of a vinyl cyanide compound unit and an aromatic vinyl compound unit bonded to a rubbery polymer is 32 to 37.
% By weight, and the amount of the vinyl cyanide compound unit is 20 to
37% by weight of a resin composition containing a copolymer of aromatic vinyl compound units, the content of vinyl cyanide compound units in the total free polymer being adjusted to 22 to 35% by weight It was done. This technique is to provide a graft chain having a vinyl cyanide compound unit content higher than 25 to 30% by weight, which is a vinyl cyanide compound unit content of a component excluding a rubbery polymer, of a general ABS resin. It is intended to impart chemical resistance to the resin composition, thereby preventing stress cracks at the time of coating and avoiding the suction of paint. However, with this technology focusing only on the graft chain,
If an attempt is made to increase the content of the vinyl cyanide compound unit in order to further improve the coating performance, the impact resistance is lowered, and this is not practical.

Japanese Patent Publication No. 63-60953 discloses a copolymer comprising a vinyl cyanide compound unit and an aromatic vinyl compound unit having a high content of vinyl cyanide compound unit of 38 to 65% by weight, and a general ABS resin. There is a technical disclosure that uses a mixture. Even with this technique, when further coating performance is demanded to increase the content of the vinyl cyanide compound unit in the copolymer, there is a drawback that the impact fluidity as well as the processing fluidity are reduced and the copolymer is not practical.

That is, in the range of the prior art, it was impossible to produce an ABS resin having sufficient coating performance and having both impact resistance and processing fluidity.

[Problems to be solved by the invention]

It is an object of the present invention to provide an excellent coating performance with high sharpness of a coated surface without generating stress cracks and paint suction during coating without annealing a molded product as in the conventional case, and sufficient processing flow. An object of the present invention is to provide a resin composition having properties and impact resistance.

[Means for solving the problem]

The present inventors have conducted intensive studies to solve the above problems, and as a result, simply increasing the amount of either the vinyl cyanide compound unit of either the graft copolymer or the free copolymer is not sufficient, and the specific composition and It has been found that only a resin composition having a composition distribution satisfies coating performance, impact resistance, and processing fluidity, and has reached the present invention.

In addition, the increase in the hygroscopicity of the resin composition by increasing the content of the vinyl cyanide compound unit, and the poor molding phenomenon due to the resin absorbing moisture cause the total amount of sodium and potassium remaining in the resin composition to be constant. The inventors have found that the solution can be achieved by reducing the amount, and completed the present invention.

That is, the present invention provides a copolymer (I) obtained by copolymerizing a rubbery polymer (B) with a vinyl cyanide compound (A) and an aromatic vinyl compound (S), and a vinyl cyanide compound (A) And a copolymer (II) of an aromatic vinyl compound (S) and an aromatic vinyl compound (S).
The resin composition having the characteristic of v) is used for coating.

(I) 5 to 50% by weight of (B) in the resin composition. (Ii) Acetone-soluble resin component (P) in the resin composition.
Has an average content (M) of the vinyl cyanide compound unit of 50 to
(Iii) AS component of (I) and (II) have substantially the same (M). (Iv) 70% by weight or more of (P) is in the range of (M) ± 2.5 mol% Exists within.

Further, depending on the application, a part of the aromatic vinyl compound unit can be replaced with an acrylate or a methacrylate.

In addition, in order to avoid molding defects due to moisture absorption of the resin composition, the total amount of sodium and potassium remaining in the resin composition is determined when the average content (M) of the vinyl cyanide compound unit is 50 mol%. It is preferably 150 ppm or less, and in the case of 65 mol%, 60 ppm or less, which is preferably within the range of the ABCD section shown in FIG.

 Hereinafter, the present invention will be described in more detail.

The chemical resistance of the ABS resin is based on the copolymer (I) obtained by graft copolymerizing a vinyl cyanide compound (A) and an aromatic vinyl compound (S) on a rubbery polymer or a copolymer of a vinyl cyanide compound and an aromatic vinyl compound. It is known that the content increases with an increase in the content of the vinyl cyanide compound unit in the copolymer (II). It is also pointed out by the prior art that the improvement in chemical resistance can prevent appearance defects during painting to some extent.

On the other hand, it is also known that an increase in the content of the vinyl cyanide compound unit decreases the processing fluidity and impact resistance of the resin composition, and distortion tends to remain in a molded article of the resin composition having low processing fluidity. When it comes into contact with paints and thinners, stress cracks occur, and conversely, the appearance of the paint is often impaired. Further, it is clear that a resin composition having low impact resistance is not industrially useful. As an ABS resin for coating, the technical point was how much the content of the vinyl cyanide compound unit could be increased without impairing the processing fluidity and impact resistance. The prior art increases the vinyl cyanide compound content of either copolymer (I) or (II) to ensure chemical resistance, and the remaining copolymer has a relatively low vinyl cyanide compound unit content. It is based on the idea of maintaining the processing fluidity and impact resistance by limiting the content.

In these technologies, the presence of a component having a relatively low content of a vinyl cyanide compound unit lowers the chemical resistance.
Sufficient coating performance cannot be obtained. In the prior art, paintability, processing fluidity and impact resistance are inconsistent properties, and it has been difficult to achieve both.

The present inventors have conducted a thorough study to provide a resin composition having a high vinyl cyanide compound unit content and excellent coating performance without impairing the processing fluidity and impact resistance.
The present invention has been reached. In particular, AS of the graft copolymer (I)
The component and the copolymer (II) should have substantially the same average content of vinyl cyanide compound units;
The discovery that the distribution of the composition of the acetone-soluble resin component (P) in the resin composition should be narrow, from the prior art,
It was not expected. Based on this discovery, the average content (M) of vinyl cyanide compound units was 55-65 for the first time.
The use of an ABS resin in a mol% (33.8 to 48.6% by weight) higher than that of a general ABS resin has become practical.

The coating performance referred to in the present invention means that, when the coating, the thinner and the resin molded product come into contact with each other, a stress crack does not occur, so that the “sucking phenomenon” of the coating does not occur.
This means that the image definition of the painted surface (hereinafter simply referred to as the sharpness) is high and an appearance similar to that of a painted steel plate can be obtained. At the same time, since the processing fluidity is as high as general ABS, the weld line during injection molding is shallow and inconspicuous, and it is not necessary to add a large amount of a plasticizer composed of a low molecular compound for the purpose of improving the processing fluidity. It does not cause paint repelling phenomenon and poor adhesion phenomenon, and means comprehensively excellent coating performance.

(A) Next, the average content of the vinyl cyanide compound unit,
The distribution of the composition will be described.

In the resin composition of the present invention, the average content (M) of the vinyl cyanide compound unit of the acetone-soluble resin component (P) is 50 to 65 mol%, preferably 53 to 60 mol%, more preferably Is 55 to 58 mol%. If (M) is less than 50 mol%, suction during coating tends to occur, and if it exceeds 65 mol%, it is not preferable in terms of processing fluidity.

The AS component of the copolymer (I) constituting the resin composition and the copolymer (II) should have substantially the same (M). The allowable width that can be regarded as substantially the same is the difference between the average content of the vinyl cyanide compound unit of the AS component of the copolymer (I) and the average content of the vinyl cyanide compound unit of the copolymer (II). It is within 5 mol%. If the difference in the average content is larger than this range, the dispersion of the copolymer (I) in the copolymer (II) becomes uneven, and the impact resistance is reduced.

The degree of the composition distribution of the acetone-soluble matter (P) in the resin composition is important, and within the range of (M) ± 2.5 mol%, the content of (P)
It should contain at least 0% by weight, preferably at least 75% by weight, particularly preferably at least 80% by weight. For example, even if the same (M) is finally obtained, a copolymer (II) having a low content of a vinyl cyanide compound unit and a copolymer (II) having a high content thereof are obtained by mixing. A resin composition having a wide composition distribution results in inferior coatability, particularly sharpness of a coated surface, as compared with a resin composition having a narrow composition distribution.

The degree of the composition distribution of the acetone-soluble matter (P) can be determined by a known method (ACTA POLYMERICA 33 614 (1982) or MACROMOLEC).
ULES 17 962 (1984) can be analyzed in accordance with, and so on). The degree of distribution of the content of (P) in the present specification is obtained by reading the peak area of the obtained chromatogram as the weight.

[B] A method for producing a resin composition having a narrow composition distribution will be described.

When producing the resin composition of the present invention, the composition ratio of the vinyl cyanide compound to be reacted and the aromatic vinyl compound,
The vinyl cyanide compound concentration is higher than the azeotropic composition of both monomers. Therefore, when trying to react all the monomers by a simple batch operation, the copolymer obtained immediately after the start of the polymerization and the copolymer obtained at the end of the polymerization have different contents of the vinyl cyanide compound unit, and the composition The copolymer is not narrowly distributed.

When copolymerization is carried out by a batch operation, it is preferable that the monomer added be reacted immediately while the monomer mixture is continuously added to the reaction system. Specifically, the polymerization rate is 90%, preferably 9% in a time region of 3/4 or more of the total addition time.
It is preferable to keep it at 3% or more. A known method can be applied to maintain a high polymerization rate, and examples thereof include setting a long additional addition time, using a large amount of a polymerization initiator, and setting a high reaction temperature.

In order to further narrow the composition distribution, a graft copolymerization having a high rubbery polymer content is carried out by the above-mentioned method, and this is copolymerized by a complete mixing continuous polymerization process having essentially no composition distribution. A method of mixing and using a polymer may be used. This method uses a solution polymerization method when the vinyl cyanide compound is acrylonitrile and the aromatic vinyl compound is styrene, and when a part of the aromatic vinyl compound is replaced with an acrylate or methacrylate. Is particularly effective.

When a copolymer based on this method and a graft copolymer having a high rubbery polymer concentration based on the above-mentioned batch operation are mixed, an AS component of the graft copolymer and a vinyl cyanide compound of the copolymer are mixed in advance. It is necessary to measure the content and combine them so that they match as much as possible.

When α-methylstyrene is used as the aromatic vinyl compound, an emulsion polymerization method is often applied due to restrictions on the polymerization rate. Since α-methylstyrene has a higher alternating copolymerizability with a vinyl cyanide compound than styrene, a composition distribution is likely to occur when an attempt is made to increase the content of vinyl cyanide compound units. In order to keep the composition distribution width within an allowable range, it is preferable that the polymerization system is always kept highly active and the weight mixture continuously added to the polymerization system is reacted promptly. At this time,
It is important to select an emulsifier to be used. A mixed emulsifier comprising 70 to 30% by weight of sodium or potassium rosinate and 30 to 70% by weight of sodium or potassium alkenyl succinate is added in an amount of 1.5 to 1.5 parts by weight based on the total amount of monomers. It is preferred to use up to 3.0 parts by weight. In the case of sodium or potassium rosinate alone, the rise of polymerization is slow, and
A polymerization rate of 90% or more cannot be achieved in the time period of 3/4 hours, and sodium or potassium alkenyl succinate alone,
The polymerization system thickens and the polymerization rate at the end of the polymerization decreases. If the amount of the mixed emulsifier is less than 1.5 parts, the rise of polymerization is slow.
If it exceeds 3.0 parts, the viscosity increases, which is not preferable.

[C] The types of monomers used for copolymerization and the molecular weight of the copolymer will be described.

A standard resin composition according to the present invention uses acrylonitrile as a vinyl cyanide compound and styrene as an aromatic vinyl compound. When processing fluidity is required for the resin composition, a part of the aromatic vinyl compound can be replaced with an acrylate or a methacrylate. As the ester monomer, butyl acrylate is preferable, and 5 to 60% by weight of the aromatic vinyl compound.
Preferably, replacement of 10 to 40% by weight is possible. If the amount of the ester monomer is less than 5% by weight, the effect is insufficient, and if it exceeds 50% by weight, the heat resistance is lowered, which is not preferable.

When heat resistance is required for the resin composition, α-methylstyrene can be used as the aromatic vinyl compound.

The molecular weight of the acetone-soluble component (P) in the resin composition may be set according to the strength required for the product and the processing fluidity. The molecular weight is represented by the reduced viscosity η _SP / C (30 ° C., methyl ethyl ketone solvent, 0.5% by weight concentration), and when the product is obtained by injection molding, 0.3 to 0.7, preferably 0.35 to 0.7
0.6, 0.4 ~ 1 in case of blow molding method and sheet molding method.
0 is preferably in the range of 0.5 to 0.8.

The copolymer graft ratio to the rubbery polymer defined by the following formula is preferably 30 to 70%.

[D] The rubbery polymer will be described.

Examples of the rubbery polymer include polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, diene rubbers such as polyisoprene and polychloroprene, and butyl acrylate-methyl methacrylate- (meth) acrylate copolymer. And saturated rubbers such as acrylic rubber, ethylene-propylene copolymer rubber, hydrogenated polybutadiene, fluorine-based rubber, and silicone rubber.

The optimum value of the particle size of the rubbery polymer varies depending on the composition of the monomer units constituting the copolymer (II). Copolymer (I
When I) is composed of an acrylonitrile-styrene copolymer and an acrylonitrile-styrene- (meth) acrylate, the preferred particle size is in the range of 0.2 to 0.4 μm. When the copolymer (II) is an acrylonitrile-α-methylstyrene copolymer, it is preferably 0.1 to 0.2 μm.

The particle size of the rubbery polymer to be used can be determined from an electron micrograph of rubber latex as a raw material.

The content of the rubbery polymer in the final resin composition is 5
5050% by weight, preferably 10-30% by weight.

[E] The allowable amount of sodium and potassium remaining in the resin composition will be described.

One of the features of the resin composition of the present invention is that the content of the vinyl cyanide compound unit is higher than that of a general ABS resin. In general, a vinyl cyanide compound is said to have hydrophilicity, and a resin obtained by copolymerizing the compound exhibits hygroscopicity. If the moisture-absorbed resin is heated and molded as it is, the vaporized moisture causes silver marks (flash) on the surface of the molded product, prominent die lines, embraces air bubbles, and reduces the appearance and strength of the product. In general, pre-drying is generally performed on a general ABS resin prior to heat molding. To enable the resin composition of the present invention to be dried at a temperature of 80 to 90 ° C. for 2 to 4 hours, which is a general drying condition of an ABS resin, to such an extent that a molded article does not have poor appearance, it is surprisingly possible. The total amount of sodium and potassium in the resin composition is important. Sodium and potassium are derived from the emulsifier used for the emulsion polymerization, the polymerization initiator, and the like, and in the salting-out step after the completion of the polymerization,
It is presumed that the polymer did not completely react with the acid or the inorganic electrolyte for polymer precipitation and did not completely disappear, or it reacted but was not washed out in the washing step. Although details are unknown, a molding failure phenomenon caused by insufficient drying can be avoided by reducing the total amount of sodium and potassium. sodium,
The residual amount of potassium can be measured by an atomic absorption method.

The allowable value of the total amount of sodium and potassium is the average content (M) of the vinyl cyanide compound unit of the copolymer (II).
Depends on That is, at 50 mol% where (M) is relatively small, the content is 150 ppm or less, preferably 85 ppm or less.
(M) becomes large, 60 ppm at 65 mol%, preferably 2 ppm
It is 5 ppm or less. The same applies when styrene or α-methylstyrene is used as the aromatic vinyl compound, and when a part of the aromatic vinyl compound is replaced with an acrylic ester or a methacrylic ester. The permissible and preferred ranges are shown in FIG. 1 in sections ABCD and A'B ', respectively.
Shown as CD.

To reduce the amount of sodium and potassium,
The use of an emulsifier containing potassium and a polymerization initiator may be reduced, and the salting-out slurry may be sufficiently washed.
Preferably, in the emulsion polymerization method, only a graft copolymer having a high rubbery polymer content is prepared, and the graft copolymer is diluted with a sodium- and potassium-free copolymer obtained by a solution polymerization method to obtain a product. No.

It is optional to add known additives to the resin composition, for example, antioxidants, ultraviolet absorbers, lubricants, mold release agents, flame retardants, antistatic agents, coloring agents, and the like. Further, reinforcement with glass fiber, carbon fiber or the like is optional.

〔Example〕

Hereinafter, the present invention will be described based on examples, but these do not limit the present invention. The parts used in the examples and comparative examples are parts by weight.

Example 1 (Experiment No. a-1, where the copolymer (II) is first obtained at the time of preparing the graft copolymer (I)), namely, the one-stage polymerization method of the resin composition, ), Example 2 (a-3), Example 3 (a-4), Example 4 (a-6), and Comparative Example 1 (a-
2), Comparative Example 2 (a-5), and Comparative Example 3 (a-7). Next, as a method of synthesizing a resin composition by blending (1), Production Example 1 (b-1) to Production Example 4 ( The graft copolymer (I) was synthesized in b-4), and Production Example 5 (c-1) to Production Example 8 were produced.
By synthesizing the copolymer (II) in (c-4) and mixing both, Examples 5 to 10 and Comparative Examples 4 to 8 (shown in Table 2-3) as resin compositions are shown. Then, as a blend synthesis method (2) of a resin composition, Production Example 9 (D-1)
-The graft copolymer (I) was synthesized in Production Example 15 (D-7), and the copolymer (II) was emulsion-polymerized in Production Example 16 (E-1)-Production Example 26 (E-11). Examples 11 to 17 and Comparative Example 9 which were synthesized into a resin composition by mixing both
To 17 (Table 3-3).

Example 1 (Experiment No. a-1) Polybutadiene rubber latex (weight average particle size 3000)
Ii) 16 parts of rubber solids, 100 parts of deionized water, and 1.0 part of potassium rosinate were placed in a polymerization tank equipped with a reflux condenser, the gas phase was replaced with nitrogen, and the temperature was raised to 70 ° C. To this latex, 33.6 parts of acrylonitrile, 50.4 parts of styrene, 0.85 parts of t-dodecyl mercaptan, and 0.
An aqueous solution obtained by dissolving 0.2 part of sodium formaldehyde sulfoxylate, 0.004 part of ferrous sulfate, and 0.04 part of disodium ethylenediaminetetraacetate in 50 parts of a monomer mixture of 1 part and deionized water for 6 hours The reaction was continuously added. During this period, the temperature of the polymerization system was controlled at 70 ° C., and after the addition was completed, the state was maintained for another hour to complete the reaction.

At 1.5 hours after the start of the reaction, the conversion was 90% or more, and thereafter maintained a high conversion of 90% or more.
93.4%.

The graft ratio to the rubbery polymer was 54% (I)
In -1, it was confirmed that an acrylonitrile-styrene copolymer corresponding to the copolymer (II) was also formed at the same time as the graft reaction for forming the copolymer (I).

The obtained copolymer latex was diluted with deionized water to a solid content of 10%, heated to 80 ° C., and 1.3 parts of magnesium sulfate was added to 100 parts of the solid content to coagulate the latex. The coagulated material was centrifugally dehydrated to obtain a cake having a water content of 65%. The dehydrated cake was subjected to reslurry washing twice, and dried flakes were obtained using a circulating hot air dryer at 90 ° C. To 100 parts of the dried flakes, 0.2 parts of an antioxidant (BHT manufactured by Sumitomo Chemical Co., Ltd.) and 0.5 parts of a release agent (ethylene bisstearylamide) were added, and pelletized by an extruder.
The pellets were injection molded at a cylinder temperature of 240 ° C. and a mold temperature of 45 ° C. to obtain dumbbell test pieces based on ASTM D-638.

The obtained test specimen was immersed in an acrylic paint solution (Reclac ^R 55: non-brushing: 169 thinner = 50: 15: 35 manufactured by Fujikura Kasei Co., Ltd.) adjusted to 23 ° C. for 20 seconds, and then at 80 ° C. for 30 minutes. After drying, the presence or absence of cracks and paint suction was visually determined.

Moreover, the conductive paint specimen (manufactured by NOF Corp. conductive primer) were spray-coated, further spraying a urethane coating (manufactured by NOF Corp. High Urethane ^R 5000), was dried for 20 minutes at 75 ° C.. The sharpness of the painted surface was measured using an image clarity measuring device (image clarifying device ICM-1D type, manufactured by Suga Test Instruments Co., Ltd., slit interval 1 mm, reflection angle 45 °).

The composition distribution of the resin composition was measured by the following method.

Component (P) extracted from resin composition using acetone
Based on the method described in the literature, tetrahydrofuran and n-hexane are used as a developing solvent, a silica column (ZORBAX-CN manufactured by Du-Pont) is used as a column, and UV (25
4 nm) and analyzed by liquid chromatography (GE-LC, G-II system manufactured by Shimadzu Corporation).

 The mechanical properties of the resin composition were measured based on the specifications.

Example 2 (a-3), Example 3 (a-4) and Comparative Example 1 (a-2), Comparative Example 2 (a-5) The same polymerization as in Example 1 (a-1) was carried out. This was carried out by changing the composition of the monomer to be used and the amount of t-dodecyl mercaptan used. Post-processing and analysis were performed by the same operation as in a-1.

Example 4 (a-6) 40 parts of acrylonitrile were added to 20 parts of the rubbery polymer solid content.
A monomer mixture of 24 parts of styrene, 16 parts of butyl acrylate, and 1.3 parts of t-dodecyl mercaptan was reacted. Post-processing was performed by the same operation as a-1.

Comparative Example 3 (a-7) Exactly the same reaction as in a-1 was performed by shortening the continuous addition time of the monomer mixture and the aqueous solution to 3 hours. The polymerization rate at 1.5 hours after the start of polymerization was 84%, and the final polymerization rate was 92.7%.

Post-processing, evaluation, and analysis were performed by the same operation as a-1. The production methods and results of a-1 to a-7 are collectively shown in Table 1. Judgment of the quality of the resin composition is made in consideration of the properties required for automotive exterior parts, the melt flow rate is 15 g / 10 min or more, the Izod impact value is 15 kg / cm / cm or more, and no paint is sucked in. The surface clarity of 45% or more was preferred.

In addition, composition a-1 (Example 1), composition a-7 (Comparative Example 3), b-1 and c-
FIG. 2 shows a chromatogram of the acetone-soluble matter having the composition of Example 1 (Example 5). FIG. 2 shows the elution time on the horizontal axis,
This is a chromatogram in which the vertical axis is a detection amount. A copolymer molecule having a large acrylonitrile content has a longer elution time, so that a composition having a smaller composition distribution gives a sharper peak.
Using this method, it was determined that the composition distribution was smaller in the order of Comparative Example 3, Example 1, and Example 5.

Production Example 1 (b-1) Polybutadiene rubber latex (3000Å) rubber solids
40 parts, deionized water 100 parts, potassium rosinate 0.3 part, t-
0.2 parts of dodecyl mercaptan was placed in a polymerization vessel equipped with a reflux condenser, and the gas phase was replaced with nitrogen, and then heated to 70 ° C. 24 parts of acrylonitrile, 36 parts of styrene, 0.15 part of cumene hydroperoxide, 0.4 part of t-dodecyl mercaptan, and 50 parts of deionized water, 0.3 part of sodium formaldehyde sulfoxylate, 0.004 part of ferrous sulfate, ethylenediaminetetraacetic acid An aqueous solution to which 0.04 parts of disodium salt was added was added continuously over 7 hours to react. During this period, the temperature of the polymerization system was controlled at 70 ° C., and after the addition was completed, 0.02 parts of cumene hydroperoxide was further added, and the state was maintained for 1 hour to complete the reaction.

The obtained latex was made into dried flakes by the same method as in a-1.

Production Example 2 (b-2), Production Example 3 (b-3), Production Example 4 (b-4) b-2, b-3 are monomer compositions using the same reaction as b-1. And changing the amount of t-dodecyl mercaptan, b
-4 was performed using rubber latex as a raw material having a different particle diameter from b-1.

These polymerization methods, polymerization rates, graft rates, and acrylonitrile unit content determined from IR are summarized in Table 2-
2 is shown.

Production Example 5 (c-1) A monomer mixture comprising 37.5 parts of acrylonitrile, 37.5 parts of styrene, and 25 parts of ethylbenzene was continuously added to a continuous, complete-mixing reactor preheated to 160 ° C. ,
The reaction was carried out while dispensing an amount of the polymer solution corresponding to the added amount. After the solid content of the reaction system was stabilized at 50% by weight, the discharged polymer solution was degassed and granulated to obtain sample pellets.

Production Example 6 (c-2), Production Example 7 (c-3), Production Example 8 (c-4) c-2, c-3 were obtained by changing the composition of the monomer fed into the reactor, c -4 is obtained by changing a part of styrene to butyl acrylate.

Table 2-2 summarizes the polymerization method and the acrylonitrile content of the copolymer obtained from IR.

Examples 5 to 10 and Comparative Examples 4 to 8 b-1 to b-4 were mixed with c-1 to c-4 at the ratios shown in Table 2-3, and an antioxidant (Sumitomo Chemical Co., Ltd. BHT ) 0.2
And 0.5 part of a release agent (ethylene bisstearylamide), and the mixture was kneaded and pelletized by an extruder.

The paintability and mechanical properties were measured by the same operation as shown in a-1 and are shown in Table 2-3.

Production Example 9 (D-1) Polybutadiene rubber latex (weight average particle diameter 1500
Ii) 60 parts of rubber solids and 100 parts of deionized water were put into a polymerization tank equipped with a reflux condenser, and the gas phase was replaced with nitrogen, and then heated to 70 ° C. A monomer mixture comprising 14 parts of acrylonitrile, 26 parts of styrene, 0.3 part of t-dodecylmercaptan and 0.2 part of cumene hydroperoxide, 50 parts of deionized water, 0.4 part of sodium formaldehyde sulfoxylate and 1 part of sulfuric acid An aqueous solution obtained by dissolving 0.004 part of iron and 0.04 part of disodium ethylenediaminetetraacetic acid was continuously added over 5 hours to react. During this time, the temperature of the polymerization system was controlled at 70 ° C., and after the addition was completed, the state was maintained for another 30 minutes to complete the reaction.

Production Example 10 (D-2) to Production Example 15 (D-7) D-2 to D-7 indicate the composition of the monomer used, the amount of t-dodecyl mercaptan used, or the particle size of the raw rubber latex. It was made by changing.

 The polymerization method and the results are collectively shown in Table 3-1.

Production Example 16 (E-1) Potassium alkenyl succinate was added to 170 parts of deionized water.
(Latemur manufactured by Kao Stone Ken Co., Ltd.) ASK) 1.0 part, rosin
Dissolve 1.0 part of potassium acid and add sodium formal
0.4 parts of dehydrosulfoxylate, 0.004 parts of ferrous sulfate,
Add 0.04 parts of tylenediaminetetraacetic acid disodium salt
After the gas phase was replaced with nitrogen, the temperature was raised to 65 ° C. This water
Acrylonitrile 35 parts, α-methylstyrene 65 in the solution
Part, t-dodecyl mercaptan 1.0 part, cumene hydro
A monomer mixture consisting of peroxide 0.5 and deionized water 8
0 parts is sodium formaldehyde sulfoxylate 0.6
Parts, ferrous sulfate 0.004 parts, ethylenediaminetetraacetic acid
Aqueous solution consisting of 0.04 parts of disodium salt for 8 hours
The reaction was performed while continuously adding. 2 hours after the start of supplemental addition
, The polymerization rate exceeds 90%, and then maintains the polymerization rate of 90% or more
did. After the addition is completed, the state is maintained for one hour,
The reaction was completed. The final conversion was 98.1%.

Production Example 17 (E-2) to Production Example 26 (E-11) The composition of the monomer used, the time and method of continuous addition of the monomer mixture, and the emulsifier used Was manufactured by changing the type and amount of

After the obtained latex was frozen and the copolymer precipitate was dried, the composition and composition distribution were measured by liquid chromatography.

 The production results are shown in Table 3-2.

Examples 11 to 17 and Comparative Examples 9 to 17 The graft copolymer D and the copolymer E containing α-methylstyrene were latex-blended so as to have a solid content ratio of 30:70. Pelletization was performed by the indicated operation. A test piece was prepared by injection molding at a cylinder temperature of 260 ° C. and a mold temperature of 60 ° C., and thereafter the same evaluation as a-1 was performed.

The results are collectively shown in Table 3-3. Examples 15 and 16
Is obtained by changing the mixing ratio of the graft copolymer D-1 and the copolymer E-1 to 20:80 and 40:60.

Also, in Table 3-3, the quality of the resin composition was determined by a melt flow rate of 3.0 or more and an Izod impact strength.
A paint with a paint clarity of 60% or more, which was 8.0 or more, did not cause paint suction, and had a paint clarity of 60% or more was preferred.

Example 18 (F-3), Example 19 (F-4), Example 20 (F-6) to Example 23 (F-9), Comparative Example 18 (F-1) to Comparative Example 19 (F -2), Comparative Example 20 (F-5) Resin composition a- for evaluating the drying characteristics of the resin composition
When preparing 1, a-2 and a-4, the number of washings of the salting-out slurry was changed to prepare resin compositions F-1 to F-7 having different amounts of metal remaining in the resin. Further, the composition of (b-1) / (c-1) = 42.5 / 57.5 corresponding to Example 5,
-1) F-8, which was not subjected to reslurry washing at the time of fabrication, corresponding to Example 10 (b-3) / (c-3) =
The composition 45/55, which was not subjected to reslurry washing at the time of preparation (b-3), was designated F-9.

F to 1 to F-9 were allowed to stand in a thermostat at 30 ° C. and 100% humidity for 5 days to allow saturated moisture absorption. Each sample having absorbed moisture was dried under the conditions shown in Table 4 using a hot air circulation dryer. At this time, the dryer used had a size sufficient for the sample amount, and the sample was uniformly charged so as to have a thickness of 3 cm. Determine the moisture content of the moisture-absorbing sample and the dried sample,
Oven temperature 250 ° C using Karl Fischer moisture meter
Was measured. At the same time, injection molding the sample (cylinder
240 ° C., mold 45 ° C., no back pressure) Flash was visually determined. The results are shown in Table 4.

[Effect of the Invention] The resin composition of the present invention has excellent processing fluidity and impact resistance, and not only has excellent appearance when coated, but also has excellent chemical resistance when used as a plating material. For,
A plating surface with high definition can be obtained, and plating does not easily come off even when it comes into contact with chemicals such as gasoline and brake oil.

In addition, there is little migration of dioctyl adipate or the like, which is a plasticizer of the vinyl chloride resin, and there is no reduction in strength even when used for applications in contact with the vinyl chloride resin.

Furthermore, it has excellent resistance to freon gas used for urethane foaming, and can be used as a core material and a skin material that can withstand urethane direct foaming.

It has good light resistance in addition to chemical resistance, has little discoloration due to light, and has a high retention rate of mechanical strength.
It is possible to expand the application field of resin.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the total amount (ppm) of sodium and potassium remaining in the resin composition and the average acrylonitrile content (mol%) of acetone-soluble components, and FIG. 1, chromatograms of the acetone-soluble components of each of the resin compositions of Comparative Example 3 and Example 5 (horizontal axis: elution time, vertical axis: detection amount).

Claims (6)

(57) [Claims] A graft copolymer (I) obtained by copolymerizing a rubbery polymer (B) with a vinyl cyanide compound (A) and an aromatic vinyl compound (S), and a vinyl cyanide compound (A). ) And copolymer of aromatic vinyl compound (S) (II)
And a resin composition comprising:
A resin composition having the characteristics of (iv). (I) 5 to 50% by weight of (B) in the resin composition. (Ii) Acetone-soluble resin component (P) in the resin composition.
Has an average content (M) of the vinyl cyanide compound unit of 50 to
(Iii) The difference between the average content of the vinyl cyanide compound unit of the AS component of (I) and the average content of the vinyl cyanide compound unit of (II) is within 5 mol%. (Iv) ( At least 70% by weight of P) is present in the range of (M) ± 2.5 mol%. 2. 5 to 50% by weight of the aromatic vinyl compound (S)
2. The resin composition according to claim 1, wherein is replaced with an acrylate or methacrylate unit. 3. The rubbery polymer (B) has a particle size of 0.1 to 0.2 μm.
The resin composition according to claim 1, wherein a part or all of the aromatic vinyl compound (S) is α-methylstyrene. 4. The total amount of sodium and potassium present in the resin composition is 150 ppm or less when the average content (M) of vinyl cyanide compound units is 50 mol%, and 65 mol% or less.
In the case of the above, it is 60 ppm or less, and the compartment A shown in FIG.
The resin composition according to claim 1, which is in the range of BCD. 5. The graft copolymer (I) is obtained by graft copolymerizing a vinyl cyanide compound (A) and an aromatic vinyl compound (S) with a rubber polymer (B). Charged into a polymerization vessel as a latex, then reacted while continuously adding a monomer mixture consisting of a vinyl cyanide compound and an aromatic vinyl compound, 3/4 of the total addition time
The resin composition according to claim 1, which is the graft copolymer (I) produced by maintaining the polymerization rate at 90% or more for the above time. 6. A copolymer of a vinyl cyanide compound (A) and an aromatic vinyl compound (S) (II) which is copolymerized with a vinyl cyanide compound (A) and α-methylstyrene by means of sodium rosinate. Or potassium salt 30-70% by weight
And sodium or potassium alkenyl succinate 70 to
An emulsifier mixture consisting of 30% by weight was used in an amount of 1.5 to 3 parts by weight with respect to 100 parts by weight of the total monomers, and the emulsion polymerization reaction was carried out while continuously adding the monomer mixture. The resin composition according to claim 1, which is a graft copolymer (II) produced by maintaining the polymerization rate at 90% or more for the above time.