JPH0791347B2 - Method for manufacturing impact resistant resin - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an impact resistant resin. More specifically, the acrylic rubber produced by adjusting the refractive index by the seeded emulsion polymerization method is a thermoplastic resin obtained by graft polymerization of an aromatic vinyl monomer or the like, and has excellent colorability and surface gloss. The present invention relates to a method for producing the impact resistant resin.

"Prior Art" Conventionally, many methods have been known for blending a hard resin with rubber and producing a resin reinforced with the rubber and having excellent impact resistance. ABS resin is a typical one of this type, but a diene rubber is mainly used as a rubber component of a base. Since the weather resistance of the base rubber is poor, the ABS resin based on the diene rubber is restricted in outdoor use, which is the greatest weak point of the resin.

From such a point of view, use of a base rubber other than a diene rubber has been considered, and various examples of using a saturated rubber having good weather resistance have been proposed. An acrylate rubber-like polymer (acrylic rubber) is one example of this, but even if the diene rubber as the base rubber is simply replaced with this acrylic rubber and graft polymerization is performed,
A resin having satisfactory properties cannot be obtained. It is true that the weather resistance is greatly improved compared to the ABS resin based on diene rubber, but there are problems with the coloring property of the resin, the surface gloss of the molded product and the impact strength, It is hard to say that it is satisfactory.

A rubber-resin two-component resin reinforced with an acrylic rubber is usually produced by graft-polymerizing a latex-like rubber component with a monomer mixture forming a branch component of the graft copolymer. Acrylic rubber used as a rubber component having good weather resistance has an optical refractive index that is smaller than that of diene rubber and has a lower elastic modulus because it is softer,
It has a drawback that elastic recovery is slow and it is easily plastically modified. When a rubber-resin two-component resin is produced using such a soft acrylic rubber having a small refractive index and injection molding or the like is performed as a molding material, the base rubber and the branch component of the graft copolymer and the graft copolymer are produced. There is a large difference in the refractive index with the diluting resin blended in the copolymer, and the deformed orientation of the rubber particles becomes remarkable, so the surface of the molded product shows a pearly luster, and the rubber particles cause irregular reflection of light. The appearance becomes whitish and the color depth (saturation) is difficult to obtain especially when coloring, so the product value tends to decrease. In addition, such molded products differ greatly in the molding surface color and mechanical strength such as impact strength depending on the flow direction at the time of molding and the location of the molded product. However, there is a drawback that it leads to poor strength.

"Problems to be Solved by the Invention" The present inventors have solved the above-mentioned various drawbacks existing in a conventional method for producing a rubber-resin two-component resin using an acrylic rubber as a base rubber. As a result of intensive studies, the present invention has been achieved. That is, first, a two-step polymerization reaction is carried out by the seeded emulsion polymerization method, acrylic rubber particles are manufactured while sequentially adjusting the refractive index in layers, and then the refractive index of the rubber component and the component to be grafted are brought close to each other. By carrying out a cross-linking graft reaction by means of such a method, it is intended to provide a method for producing an impact resistant resin which has good moldability and weather resistance, and also has excellent colorability and surface gloss.

"Means for Solving Problems" The gist of the present invention is that the alkyl group has 1 to 1 carbon atoms.
8 to 100% by weight of alkyl acrylate monomer, vinyl monomer 0 to 0
A monomer mixture consisting of 30% by weight and 0 to 5% by weight of a polyfunctional vinyl monomer (however, the total amount of the monomer mixture is 100% by weight) is emulsion polymerized to obtain a rubber particle diameter of 0.03. ~
First step of producing acrylic seed rubber particles having a particle size of 0.15 μm, and using 1 part by weight of the acrylic seed rubber particles obtained in the first step as a seed, an alkyl acrylate monomer having an alkyl group having 1 to 8 carbon atoms 20-94.9% by weight, the refractive index of a single polymer is
A monomer mixture consisting of 5 to 79.9% by weight of a vinyl monomer copolymerizable with the above-mentioned alkyl acrylate of 1.50 or more and 0.1 to 5% by weight of a polyfunctional vinyl monomer (however, the monomer mixture is 100% by weight in total). 2.5 to 125 parts by weight is added, and the rubber particle diameter is 0.15 to 0.5 by the seed emulsion polymerization method.
Second step of producing an acrylic rubber having a thickness of μm, 100 parts by weight of the acrylic rubber obtained in the second step,
Aromatic vinyl monomer 0 to 80% by weight, vinyl cyanide monomer 0 to 40% by weight, vinyl monomer copolymerizable with the above aromatic vinyl monomer whose refractive index of a single polymer is less than 1.50 Body 0
A monomer mixture consisting of 99.9% by weight and 0.1 to 5% by weight of a polyfunctional vinyl monomer (however, the total amount of the monomer mixture is 10%).
It is 0% by weight. ) Addition of 10 to 100 parts by weight and a cross-linking graft reaction by a seeded emulsion polymerization method, a third step, a polymerization system after the third step is further added, 10 to 90% by weight of an aromatic vinyl monomer, and cyan. Grafting is performed by adding 55 to 185 parts by weight of a monomer mixture consisting of 10 to 40% by weight of vinyl chloride monomer and 0 to 80% by weight of methyl methacrylate (however, the total amount of the monomer mixture is 100% by weight). A fourth step of carrying out polymerization comprises a method for producing an impact resistant resin.

Hereinafter, the present invention will be described in detail.

The first step in the present invention refers to a step of producing acrylic seed rubber particles during seeding emulsion polymerization. The acrylic seed rubber particles produced in the first step are first added to the emulsion polymerization system during the production of the acrylic rubber and serve as seeds for producing an acrylic rubber having a large rubber particle diameter.

The acrylic seed rubber particle in the present invention means an alkyl acrylate monomer having an alkyl group having 1 to 8 carbon atoms 70 to 100
% By weight, 0 to 30% by weight of a vinyl monomer copolymerizable with the above alkyl acrylate, and 0 a multifunctional vinyl monomer.
˜5% by weight of the monomer mixture (however, the total amount of the monomer mixture is 100% by weight; the same applies hereinafter) (I) is produced by emulsion polymerization and has a rubber particle diameter of 0.03 to 0.15 μm. Say.

The alkyl acrylate monomer, which is a constituent of the acrylic seed rubber particles, refers to an alkyl acrylate having 1 to 8 carbon atoms in the alkyl group. Specific examples thereof include alkyl acrylates such as ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate. These may be one kind or a mixture of two or more kinds.

The monomer mixture (I) used for the production of the acrylic seed rubber particles contains the alkyl acrylate monomer in an amount of 70 to 100.
Must be contained in the range of wt%. If the content is less than 70% by weight, the elasticity of the seed rubber particles becomes small, and the affinity with the acrylic rubber layer formed on the outer layer of the seed rubber particles decreases, which is not preferable.

Examples of the vinyl monomer copolymerizable with the alkyl acrylate include aromatic vinyl monomers described below, vinyl cyanide monomers described below, acrylamide, methacrylamide, vinylidene chloride, alkyl vinyl ethers, alkyl vinyl esters, and alkyl methacrylates. And halogen-substituted compounds thereof. These may be one kind or a mixture of two or more kinds.

The amount of the copolymerizable vinyl monomer contained in the monomer mixture (I) must be selected in the range of 0 to 30% by weight. When the copolymerizable vinyl monomer exceeds 30% by weight, various properties of the seed rubber particles are deteriorated, which is not preferable.

The polyfunctional vinyl monomer in the present invention means a vinyl monomer containing two or more vinyl groups in one molecule of the monomer in order to crosslink the acrylic seed rubber. Specific examples of the polyfunctional vinyl monomer include aromatic polyfunctional vinyl monomers such as civinylbenzene and civinyltoluene, and methacrylates of polyhydric alcohols such as ethylene glycol dimethacrylate and trimethylolpropane triacrylate. And acrylate, diallyl malate, triallyl isocyanurate, diallyl phthalate, allyl methacrylate and the like. These may be one kind or a mixture of two or more kinds.

The amount of the polyfunctional vinyl monomer contained in the monomer mixture (I) must be selected in the range of 0 to 5% by weight. If this polyfunctional vinyl monomer exceeds 5% by weight,
It is not preferable because the compatibility and affinity with the acrylic rubber layer formed in the outer layer becomes poor and the various properties of the seed rubber particles deteriorate.

Acrylic seed rubber particles in the present invention, in the known emulsion polymerization using water as a medium, appropriately combine various kinds of known conditions such as the type and amount of the emulsifier and the polymerization catalyst, the addition method thereof, and the addition method of the monomer. Can be manufactured.

The acrylic seed rubber particles have a rubber particle diameter of 0.03 to 0.15.
Must be μm. If the rubber particle size is smaller than 0.03 μm, it cannot be produced by a usual emulsion polymerization method, and the emulsifier concentration becomes high, resulting in a special economical method.
If the rubber particle diameter exceeds 0.15 μm, the composition and refractive index of the acrylic rubber produced in the second step cannot be optimized, and an impact resistant resin having excellent coloring properties and surface gloss can be obtained. It cannot be manufactured.

In the present invention, the rubber particle size means the US Coulter Electronics Co.
(Coulter Electronics Ltd.) Nanosizer (Coulte
r Nano-Sizer^TM) Put the latex in water at 23 ° C.
It refers to the weight average rubber particle diameter measured in a dispersed system.

In the second step of the present invention, by the seed emulsion polymerization method,
Manufacture acrylic rubber. In this second step,
By copolymerizing a monomer having a high refractive index, an acrylic rubber having a higher refractive index than that of a conventional acrylic rubber can be obtained.

The acrylic rubber in the present invention is obtained by using 1 part by weight of the acrylic seed rubber particles obtained in the first step as a seed, and an alkyl acrylate monomer having an alkyl group having 1 to 8 carbon atoms.
94.9% by weight, a vinyl monomer 5 to 7 copolymerizable with the above alkyl acrylate having a refractive index of 1.50 or more as a single polymer
9.9% by weight, and 0.1-5% by weight of multifunctional vinyl monomer
2.5 to 125 parts by weight of a monomer mixture (II) consisting of
It is produced by the seeded emulsion polymerization method. Rubber particle size is 0.15 to 0.
It means that it is 5 μm.

Examples of the alkyl acrylate monomer that is a constituent of the acrylic rubber include the alkyl acrylate monomers exemplified above as the constituent of the acrylic seed rubber particles. These may be one kind or a mixture of two or more kinds. Monomer mixture (I
I) contains the alkyl acrylate monomer in the range of 20 to 94.9% by weight. When the content is less than 20% by weight, the rubber elasticity of the acrylic rubber becomes small, which is not preferable. Further, the content of the alkyl acrylate monomer does not exceed 94.9% by weight because the monomer mixture (II) contains other components.

A vinyl monomer that is a constituent of this acrylic rubber and has a refractive index of a single polymer that is copolymerizable with the above alkyl acrylate having a refractive index of 1.50 or higher is a polymer obtained by homopolymerizing this vinyl monomer. Having a refractive index of 1.50 or more. As the vinyl monomer copolymerizable with the alkyl acrylate having a refractive index of 1.50 or more of the single polymer,
Examples thereof include butadiene, vinyl chloride, vinylidene chloride, acrylonitrile, vinylnaphthalene, vinylcarbazole, styrene, α-methylstyrene, α-chlorostyrene, vinyltoluene, dichlorostyrene, cyclohexyl methacrylate and benzyl methacrylate. These may be one kind or a mixture of two or more kinds.

The amount of the vinyl monomer component copolymerizable with the alkyl acrylate having a refractive index of the homopolymer of 1.50 or more to be contained in the monomer mixture (II) should be selected in the range of 5 to 79.9% by weight. I have to. If the amount of the copolymerizable vinyl monomer component is less than 5% by weight, the refractive index of the resulting acrylic rubber becomes small and the difference in the refractive index between the branch component of the graft copolymer and the diluting resin is small. It becomes large, which is not preferable. The copolymerizable vinyl monomer component does not exceed 79.9% by weight because the monomer mixture (II) contains other components.

In the present invention, the refractive index refers to that measured according to JIS K7105-1981, using an Abbe refractometer, and measured with a D line at 23 ° C. Na.

The acrylic rubber in the present invention contains the polyfunctional vinyl monomer component exemplified above as the constituent component of the acrylic seed rubber particles. This polyfunctional vinyl monomer is used in the monomer mixture (II) used in the seed emulsion polymerization of acrylic rubber.
It must be contained in the range of 1 to 5% by weight. When the content is less than 0.1% by weight, the acrylic rubber becomes soft and has fluidity, which is not preferable. When the content of the polyfunctional vinyl monomer exceeds 5% by weight, the rubber elasticity is lost,
It becomes hard, which is not preferable.

The actag rubber according to the present invention is produced by adding the monomer mixture (II) in an amount of 2.5 to 125 parts by weight to 1 part by weight of the acrylic seed rubber particles and by a seed emulsion polymerization method. When the amount of the monomer mixture (II) is less than 2.5 parts by weight, the rubber particle size of the acrylic rubber does not increase to the target rubber particle size and a layer having a sufficient thickness cannot be formed, which is not preferable. When the amount of the monomer mixture (II) is more than 125 parts by weight, it takes time to polymerize by the seed emulsion polymerization method, which is not economical.

In this seed emulsion polymerization of acrylic rubber, polymerization is initiated by adding the monomer mixture (II), a polymerization initiator and the like to a seed polymerization system containing latex-like acrylic seed rubber particles. At this time, it is preferable to appropriately divide the monomer mixture (II), the emulsifier, the polymerization initiator and the like according to the polymerization rate of the seeding polymerization, and add them over time. Further, the additive composition of the monomer mixture (II) can be appropriately changed, for example, from the initial stage to the latter stage of the polymerization reaction to increase the refractive index sequentially from the inner layer to the outer layer of the acrylic rubber, thereby increasing the acrylic rubber. It is possible to improve the appearance of the molded product by making the refractive index of the rubber base and the graft copolymer branch component approximate to each other without lowering the reinforcing effect.

The seeded emulsion polymerization can be carried out by an ordinary emulsion polymerization method using water as a medium. When the emulsion polymerization method is adopted, known polymerization initiators and polymerization initiators such as potassium persulfate and hydroperoxide, anionic surfactants such as potassium fatty acid, and cationic surfactants such as quaternary ammonium salts. Known emulsifiers such as nonionic surfactants such as polyethylene glycol derivatives can be used. The amount of the emulsifier used for this seed emulsion polymerization is an amount required according to the expansion of the rubber particle surface accompanying the polymerization reaction of the acrylic rubber. In this way, the rubber particle size can be increased as the polymerization reaction rate increases.

The rubber particle diameter of the acrylic rubber in the present invention is 0.15 to
Adjust within the range of 0.5 μm. If the rubber particle size of the acrylic rubber is smaller than 0.15 μm, the impact resistance of the graft copolymer cannot be improved, which is not preferable. 0.5μ
If it is larger than m, the polymerization takes too long and is not economical.

In the third step of the present invention, the seed emulsion polymerization method is used.
Crosslinking graft reaction is performed on acrylic rubber. The hard cross-linked graft copolymer formed in the third step covers the acrylic rubber produced in the second step and is between the acrylic rubber and the diluting resin and has a low refractive index. Approximate the refractive index with a diluting resin having a high refractive index. As a result, it is possible to reduce defective phenomena such as pearly luster and defective coloring that appear in the appearance of the molded product of the graft copolymer.

In the cross-linking graft reaction in the third step of the present invention, 100 parts by weight of the acrylic rubber obtained in the second step is added to 0 to 80% by weight of an aromatic vinyl monomer and 0 to 40% of a vinyl cyanide monomer. 0 to 9% by weight of a vinyl monomer copolymerizable with the above-mentioned aromatic vinyl monomer having a refractive index of a single polymer of less than 1.50.
10 to 100 parts by weight of a monomer mixture (III) consisting of 9.9% by weight and 0.1 to 5% by weight of a polyfunctional monomer is added, and seeded emulsion polymerization is carried out.

Specific examples of the aromatic vinyl monomer used in the cross-linking graft reaction include styrene, α-methylstyrene, and other α-
Examples include nuclear substituted alkylstyrenes such as alkylstyrene and p-methylstyrene, vinylnaphthalene and the like. These may be one kind or a mixture of two or more kinds.

The proportion of the aromatic vinyl monomer in the monomer mixture (III) must be 0 to 80% by weight. If this ratio is more than 80% by weight, the refractive index becomes large and the miscibility becomes poor when the resin produced is mixed with other hard resin.

Specific examples of the vinyl cyanide monomer include acrylonitrile and methacrylonitrile. They are,
It may be one kind or a mixture of two or more kinds. The proportion of vinyl cyanide monomer in the monomer mixture (III) should be 0 to 40% by weight. If it exceeds 40% by weight, the dispersibility of the cross-linked and graft-polymerized resin with other resins is deteriorated, and the moldability becomes poor, which is not preferable.

The refractive index of the homopolymer is a vinyl monomer copolymerizable with the aromatic vinyl monomer of less than 1.50, the refractive index of the polymer obtained by homopolymerizing this vinyl monomer is less than 1.50. What is. Specific examples of the vinyl monomer copolymerizable with the aromatic vinyl monomer include methyl acrylate, t-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, n-butyl methacrylate and methyl methacrylate. These may be one kind or a mixture of two or more kinds.

The proportion of the vinyl monomer copolymerizable with the aromatic vinyl monomer having a refractive index of less than 1.50 in the monomer mixture (III) in the monomer mixture (III) is 0 to 99.9% by weight. Since the monomer mixture (III) contains other components, it is 99.9% by weight.
Never exceeds.

The monomer mixture (III) contains the polyfunctional vinyl monomer exemplified above as the constituent component of the acrylic seed rubber particles. Monomer mixture of this polyfunctional vinyl monomer (III)
The ratio in the inside is 0.1 to 5% by weight. If it is less than 0.1% by weight, it becomes difficult to wrap the rubber particles of the acrylic rubber by a cross-linking graft reaction to form a layered structure. When the polyfunctional vinyl monomer exceeds 5% by weight, the crosslinking density becomes high and the graft polymerization in the next fourth step becomes difficult, which is not preferable.

In the cross-linking graft reaction in the present invention, 100 parts by weight of the acrylic rubber obtained in the second step is mixed with the monomer mixture ((II
I) is added in the range of 10 to 100 parts by weight and polymerized by the seeded emulsion polymerization method. When the addition amount of the monomer mixture (III) is less than 10 parts by weight, the crosslinked graft copolymer only covers a part of the rubber particle surface of the acrylic rubber, which is not preferable. When the amount of the monomer mixture (III) exceeds 100 parts by weight, the amount of acrylic rubber in the crosslinked graft particles decreases, which is not preferable.

This cross-linking graft reaction can be carried out by a usual emulsion polymerization method using water as a medium, similar to the one used in the second step. At this time, it is preferable to appropriately divide the monomer mixture (III), the emulsifier, the polymerization initiator, and the like in accordance with the polymerization rate of the seed emulsion polymerization, and add them over time.

In the fourth step of the present invention, the polymerization system obtained after the third step is further added with a monomer consisting of 10 to 90% by weight of an aromatic vinyl monomer, 10 to 40% by weight of a vinyl cyanide monomer, and methyl methacrylate. 55-185 parts by weight of the monomer mixture (IV) is added and graft polymerization is carried out. The aromatic vinyl monomer and the vinyl cyanide monomer, which are the components of the above-mentioned monomer mixture (IV), are the vinyl monomers exemplified above as the components used in the cross-linking graft reaction in the third step. is there. The monomer mixture (IV) is 10 to 90% by weight of an aromatic vinyl monomer,
It is composed of 10 to 40% by weight of vinyl cyanide monomer and 0 to 80% by weight of methyl methacrylate. If it is out of this range, not only the graft polymerizability changes, it is necessary to change the polymerization conditions, but also the characteristics of the graft polymerized resin change and the types of other resins to be mixed are limited, which is not preferable.

In the fourth step, the monomer mixture (IV) was added in an amount of 55 to 185 parts by weight to the polymerization system in which 100 parts by weight of the acrylic rubber in the third step was subjected to the cross-linking graft reaction, and graft polymerization was performed. Do. The monomer mixture (I
If the amount of V) is less than 55 parts by weight, a sufficient amount of resin to cover the surface of the rubber particles of the acrylic rubber latex cannot be produced by graft polymerization, and the graft ratio becomes small, resulting in a graft copolymer. It is not preferable because it lowers the impact resistance and dispersibility. If the amount added exceeds 185 parts by weight, the graft ratio will be saturated and constant, only the resin not graft-polymerized will increase, and the concentration of acrylic rubber in the resin will decrease, which is not preferable.

The graft polymerization can be performed by an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, a bulk polymerization method, or the like. When the emulsion polymerization method is used, the usual emulsion polymerization method using water as the medium described in the seeded emulsion polymerization method can be used.

In carrying out the graft polymerization other than the emulsion polymerization method,
First, the surface of the acrylic rubber particles is coated with a hard resin, and when it becomes possible to disperse only the rubber particles, the emulsion system is changed to a suspension system, a solution system or a bulk polymerization system, and the graft polymerization is continued. It is better to take the method.

The resin obtained by the method of the present invention can be directly used for molding and the like. In addition, other thermoplastic resins such as polystyrene, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-ethylene-propylene-diene-styrene copolymer (AES Resin), polymethylmethacrylate, polyvinyl chloride, polycarbonate, polyamide, polybutylene terephthalate, polyphenylene oxide, etc., and can be used as a weather resistant and impact resistant resin.

The resin obtained by the method of the present invention includes various kinds and amounts of lubricants, mold release agents, colorants, ultraviolet absorbers, light resistance stabilizers, heat resistance stabilizers, fillers and the like which do not impair the properties of the resin. The resin additives can be added in an appropriate combination.

The resin excellent in impact resistance obtained by the method of the present invention,
It is made into a desired molded product by various processing methods such as an injection molding method, an extrusion molding method and a compression molding method, and can be used in applications where excellent weather resistance and impact resistance are required.

"Effects of the Invention" As described above, the present invention has particularly remarkable effects as described below, and its industrial utility value is extremely large.

(1) According to the method of the present invention, by seeding emulsion polymerization, the refractive index of rubber particles of acrylic rubber can be arbitrarily optimized from the inner layer toward the outer layer.

(2) Further, since a cross-linked graft layer having an arbitrary refractive index can be provided on the outside of the acrylic rubber particles, when such a rubber graft-polymerized as a substrate is dispersed in a resin, it is diluted. Since the refractive indexes of the resin and the acrylic rubber particles are approximated in a stepwise manner, it is possible to obtain an impact resistant resin having excellent coloring properties and surface gloss.

(3) The resin obtained by the method of the present invention uses acrylic rubber having a saturated carbon-bonded main chain as a base rubber, and therefore has extremely excellent weather resistance.

(4) Since the resin obtained by the method of the present invention has excellent compatibility with this hard thermoplastic resin, a resin composition having excellent weather resistance and impact resistance can be produced by kneading and mixing. .

[Examples] Next, the present invention will be specifically described based on Examples and Comparative Examples, but the present invention is not limited to the following examples unless it exceeds the gist.

Example 1 (i) First Step: Production of Acrylic Seed Rubber Particles Butyl acrylate (abbreviated as BA hereinafter) 937.5 g, acrylonitrile (abbreviated as AN hereinafter) 62.5 g, and allyl methacrylate (abbreviated as AMA hereinafter) 5 g was weighed and mixed to prepare a monomer mixture (I).

In a 3 liter glass flask equipped with a stirrer, a reflux condenser, a thermometer, and an auxiliary addition device, 1520 g of deionized water, 20 g of higher fatty acid soap (mainly containing sodium salt of fatty acid having 18 carbon atoms), and 10 g of sodium hydrogen carbonate was charged and the internal temperature was raised to 75 ° C. under a nitrogen stream. Then, 20 m of an aqueous solution of potassium persulfate (hereinafter abbreviated as KPS) was added to this flask.
1 (containing 0.75 g of KPS) was added, followed by addition of 40 g of the monomer mixture (I), and the polymerization reaction was started at the same temperature. After 15 minutes from the initiation of the polymerization reaction, the remaining 965 g of the monomer mixture (I) was continuously added to the polymerization system at an addition rate of about 65 g / 10 minutes.

15 minutes after starting the polymerization reaction, 20 ml of KPS aqueous solution (0.7
Includes 5g KPS. ) 1 hour and 30 minutes later, the higher fatty acid soap 6
g was added. The addition of the monomer mixture (I) was completed 2 hours and 45 minutes after the initiation of the polymerization reaction. Further, the polymerization reaction was continued at the same temperature for 1 hour to complete the reaction, and acrylic seed rubber particles were obtained. The conversion rate of the used monomer is 98.5%
Met. The rubber particle size of the obtained latex was measured. The results are shown in Table 1.

(Ii) Second Step: Production of Acrylic Rubber Obtained by the method described in (i) above in a glass flask having a volume of 2 liters equipped with a stirrer, a reflux condenser, a thermometer, and an auxiliary additive addition device. Acrylic seed rubber particle latex 3
4.1g, deionized water 750g, and sodium bicarbonate 3.9g
Was charged, and the temperature inside the flask was raised to 75 ° C. KPS aqueous solution 8
ml (containing 0.3 g of KPS) was added to prepare for polymerization.

On the other hand, the following composition 3 added to the polymerization system in the second step
Type of monomer mixture (II) -A, (II) -B, (II)-
C was prepared.

The above three monomer mixtures (II) -A, (II) -B,
(II) -C was continuously added to the flask in 3 steps according to the following procedure to start and continue the polymerization reaction.

45 minutes, 1 hour 30 minutes, 3 hours, and 4 hours after the initiation of the polymerization reaction, 10 ml of an aqueous soap solution (containing 0.92 g of higher fatty acid soap) was added, respectively, and 1 hour 3
After 0 minute and 3 hours, 4 ml of KPS aqueous solution (KPS0.15
Including g. ) Each additional addition. After 4 hours and 30 minutes from the start of the polymerization reaction, the addition of the monomer mixture was completed, and then the reaction was continued at the same temperature for an additional 1 hour to complete the polymerization reaction. The rubber particle size of the obtained acrylic rubber was measured.

The results are shown in Table 1.

(Iii) Third step: Cross-linking graft reaction In the same 3 l glass flask used in the first step, the total amount of the latex of the acrylic rubber obtained by the method described in (ii) above, 750 g of deionized water, and carbonic acid were added. Sodium hydrogen
6 g was charged, and the temperature inside the flask was raised to 75 ° C. 8 ml of KPS aqueous solution (containing 0.3 g of KPS) was added to prepare for polymerization.

On the other hand, a monomer mixture (III) having the following composition to be added to the polymerization system in the third step was prepared.

Monomer mixture (III) MMA * 4 58.5g St 95.6g AN 40.9g AMA 1 g [Note] * 4: Mean methyl methacrylate.

Hereinafter, they have the same meaning.

The above monomer mixture (III) was continuously added to the flask at an addition rate of about 16.3 g / 10 min to initiate the polymerization reaction.
1 hour and 30 minutes after starting the polymerization reaction, the soap solution 20
ml (containing 1.95 g of higher fatty acid soap) was added. After 2 hours, the addition of the monomer mixture (III) was completed, and the crosslinking graft reaction was completed.

(Iv) Fourth Step: Graft Polymerization While keeping the polymerization system after the third step described in (iii) as it is, the flask internal temperature is maintained at 75 ° C., and KP is added under stirring.
8 ml of S aqueous solution (containing 0.3 g of KPS) was added. Then, a monomer mixture consisting of St286.6g and AN122.9g (I
V) was continuously added at an addition rate of about 22.8 g / 10 minutes to initiate the graft polymerization reaction.

1 hour and 3 hours after starting the polymerization reaction,
20 ml of each aqueous soap solution (containing 2 g of higher fatty acid soap) was added, and 1 hour later, 8 ml of an aqueous KPS solution (containing 0.3 g of KPS) was additionally added. 3 after starting the polymerization reaction
After a lapse of time, the addition of the monomer mixture (IV) was completed, and then the reaction was continued at the same temperature for 1 hour to complete the graft polymerization reaction.

The monomer conversion used was 99%. Graft-polymerized latex was salted out by a conventional method, washed well with water, and dried to obtain about 1 kg of a graft copolymer.

(V) Evaluation of physical properties of resin About graft copolymer obtained by the method described in (IV) above
650g, acrylonitrile-styrene resin (SAN -C,
Mitsubishi Monsanto Kasei Co., Ltd.) 650g, butylated hydroxy
Add 3 g of citoluene and 5 g of magnesium stearate.
Banbury for testing, each weighed and temperature adjusted to 180 ℃
Kneaded with a mixer, the content of acrylic rubber is 20% by weight
Pellets of the resin composition of 1. were prepared.

The pellets of this resin composition were molded into a test piece for impact resistance measurement and a test piece for gloss evaluation by an injection molding machine.
According to JIS K7110, the Izod impact strength (with notch) was measured according to JIS K7105, and the gloss based on the reflectance at an incident angle of 60 ° was measured. The results are shown in Table 1.

In order to evaluate the colorability, when kneading the raw materials for the composition by the test Banbury mixer, 5.2 g of carbon black for color is mixed and added, and by the same operation as above, the colored resin composition Pellets were prepared.

A test piece was molded from the pellet of the resin composition by an injection molding machine. With respect to the molded test piece, the colorability and the appearance were visually judged based on the following criteria. The results are shown in Table 1.

Criteria for judging colorability and appearance ⊚: Colorability is good. It becomes deep black (black). Weld line (resin fusion line) with no pearly luster
Is hardly recognized.

◯: Colorability is normal. The depth of black is lacking, and it is necessary to increase the amount of colorant for color matching. There is no pearly luster. Weld lines are slightly recognized.

X: Poor colorability. It becomes a dull gray-like black color. Color matching is difficult even if the amount of colorant is increased. It has a pearly luster and some delamination is observed. Weld lines are clearly visible.

Example 2 (i) First Step: Production of Acrylic Seed Rubber Particles Same as described in Example 1 (i).

(Ii) Second step: Production of acrylic rubber The same as described in Example 1 (ii).

(Iii) Third Step: Crosslinking Grafting Reaction In the example described in Example 1 (iii), the monomer mixture (I
II) except that the composition was changed as shown below.
The procedure was the same as in i).

Monomer mixture (III) St 136.5g AN 58.5g AMA 1g (iv) Fourth step: graft polymerization Same as described in Example 1 (iv).

(V) Evaluation of physical properties of resin Same as described in Example 1 (v).

Example 3 (i) First Step: Production of Acrylic Seed Rubber Particles Same as described in Example 1 (i).

(Ii) Second step: Production of acrylic rubber In the example described in Example 1 (ii), the monomer mixture (I
The procedure was the same as in Example (ii) except that the composition of I) was changed to the following two types and the addition was performed in two stages as shown below.

(Iii) Third step: cross-linking graft reaction The same as described in Example 1 (iii).

(Iv) Fourth Step: Graft Polymerization Same as described in Example 1 (iv).

(V) Evaluation of physical properties of resin Same as described in Example 1 (v).

Comparative Example 1 (i) First Step: Production of Acrylic Seed Rubber Particles Same as described in Example 1 (i).

(Ii) Second step: Production of acrylic rubber In the example described in Example 1 (ii), the monomer mixture (I
The composition of I) was BA390g and AMA1.95g, and the monomer mixture (II) was continuously added at an addition rate of about 14.5g / 10 minutes until 4 hours and 30 minutes passed immediately after the initiation of the polymerization reaction. The procedure was the same as in Example (ii) except that the procedure was changed to.

(Iii) Third step: cross-linking graft reaction The same as described in Example 2 (iii).

(Iv) Fourth Step: Graft Polymerization Same as described in Example 1 (iv).

(V) Evaluation of physical properties of resin Same as described in Example 1 (v).

Comparative Example 2 (i) First Step: Production of Acrylic Seed Rubber Particles Same as described in Example 1 (i).

(Ii) Second step: Production of acrylic rubber In the example described in Example 1 (ii), the monomer mixture (I
I) has a composition of BA195g, MMA195g, and AMA1.95g,
The addition method is from immediately after the start of the polymerization reaction until 4 hours and 30 minutes later.
The procedure was the same as in Example (ii), except that the monomer mixture (II) was continuously added at an addition rate of about 14.5 g / 10 minutes.

(Iii) Third step: cross-linking graft reaction The same as described in Example 2 (iii).

(Iv) Fourth Step: Graft Polymerization Same as described in Example 1 (iv).

(V) Evaluation of physical properties of resin Same as described in Example 1 (v).

Comparative Example 3 (i) First Step: Production of Acrylic Seed Rubber Particles Same as described in Example 1 (i).

(Ii) Second step: Production of acrylic rubber In the same 2 l glass flask used in the second step of Example 1 (ii), the acrylic seed rubber obtained by the method described in (i) above was added. Particle latex 34.1g, deionized water 750
g and 3.9 g of sodium hydrogen carbonate were charged, and the temperature inside the flask was raised to 75 ° C. 3 ml of an aqueous KPS solution (containing 0.1 g of KPS) was added.

A monomer mixture (II) consisting of 57 g of BA and 0.3 g of AMA was continuously added at an addition rate of 14.3 g / 10 minutes to initiate a polymerization reaction. 45 minutes after starting the polymerization reaction, 5 ml of aqueous soap solution
(Including 0.35 g of higher fatty acid soap.) After 40 minutes from the start of the polymerization reaction, the addition of the monomer mixture (II) was completed, and then the reaction was continued at the same temperature for 1 hour to complete the polymerization reaction. The rubber particle size of the obtained acrylic rubber was measured. The results are shown in Table 1.

(Iii) Third Step: Crosslinking Grafting Reaction Into the same 3 l glass flask used in the third step of Example 1 (iii), the total amount of the latex of the acrylic rubber obtained by the method described in (ii) above was added. Charge the flask temperature
The temperature was raised to 75 ° C. 4 ml of KPS aqueous solution (containing 0.15 g of KPS) was added.

Monomer mixture consisting of St21g, AN9g, and AMA0.15g (I
II) was continuously added at an addition rate of 12.0 g / 10 minutes to start the polymerization reaction. 25 minutes after starting the polymerization reaction, the addition of the monomer mixture (III) was completed, and the crosslinking graft reaction was completed.

(Iv) Fourth Step: Graft Polymerization The polymerization system obtained by the method described in (iii) and subjected to the cross-linking graft reaction was continuously stirred at a flask internal temperature of 75 ° C.

Monomer mixture (IV) consisting of St52.5g and AN22.5g,
Graft polymerization reaction was initiated by continuous addition at an addition rate of about 30 g / 10 minutes. 40 minutes after starting the polymerization reaction, 10 ml of an aqueous soap solution (containing 1.05 g of higher fatty acid soap) was added. After 25 minutes from the start of the polymerization reaction, the addition of the monomer mixture (IV) was completed, and then the reaction was continued at the same temperature for 1 hour to complete the polymerization reaction.

The polymerization addition rate was 98%. The graft-polymerized latex was salted out by a conventional method, washed and dried to obtain a graft copolymer.

(V) Evaluation of physical properties of resin In addition to changing the amount of the graft copolymer so that the acrylic rubber content of the resin composition obtained in the example described in Example 1 (v) was 20% by weight. Was the same procedure as in Example (v).

From the examples, the following is clear.

(1) Since the resin obtained by the method of the present invention gradually increases the refractive index of the inner layer and outer layer of the acrylic rubber particles of the graft copolymer and the refractive index of the diluted resin, it has excellent coloring properties and surface gloss. With.

(Table 1, Examples 1 to 3) On the other hand, in the case of the comparative example in which the refractive index of the acrylic rubber particles is small, the refractive index of the diluted resin is large, the refractive indexes do not approximate, and change greatly in a discontinuous manner. Has poor colorability or surface gloss. (Table 1, Comparative Examples 1 to 3) (2) Since the resin obtained by the method of the present invention is an acrylic rubber cross-linked copolymer rubber, butyl acrylate homopolymer rubber (some cross-linked monomer components Impact resistance is superior to that of a resin including. (Table 1, Example 1, Comparative Example 1) (3) The resin obtained by the method of the present invention has good colorability and excellent impact resistance by kneading and mixing with other hard thermoplastic resin. Resin composition.
(Table 1, Examples 1 to 3) Further, the resin composition using the resin obtained outside the range of the conditions of the method of the present invention is inferior in impact resistance. (Table 1, Comparative Example 1
~ 3)

Claims (1)

[Claims] 1. An alkyl acrylate monomer having 1 to 8 carbon atoms in an alkyl group, 70 to 100% by weight, 0 to 30% by weight of a vinyl monomer copolymerizable with the alkyl acrylate, and a polyfunctional vinyl monomer. Monomer mixture consisting of 0 to 5% by weight (however, the total monomer mixture is 100% by weight)
Is emulsion polymerized to produce acrylic seed rubber particles having a rubber particle diameter of 0.03 to 0.15 μm. 1 part by weight of the acrylic seed rubber particles obtained in the first step is used as a seed, and 20 to 94.9% by weight of an alkyl acrylate monomer having 1 to 8 carbon atoms, the refractive index of a single polymer is
A monomer mixture consisting of 5 to 79.9% by weight of a vinyl monomer copolymerizable with the above-mentioned alkyl acrylate of 1.50 or more and 0.1 to 5% by weight of a polyfunctional vinyl monomer (however, the monomer mixture is 100% by weight in total). 2.5 to 125 parts by weight is added, and the rubber particle diameter is 0.15 to 0.5 by the seed emulsion polymerization method.
Second step of producing an acrylic rubber having a thickness of μm, 100 parts by weight of the acrylic rubber obtained in the second step,
Aromatic vinyl monomer 0 to 80% by weight, vinyl cyanide monomer 0 to 40% by weight, vinyl monomer copolymerizable with the above aromatic vinyl monomer whose refractive index of a single polymer is less than 1.50 Body 0
A monomer mixture consisting of 99.9% by weight and 0.1 to 5% by weight of a polyfunctional vinyl monomer (however, the total amount of the monomer mixture is 10%).
It is 0% by weight. ) Addition of 10 to 100 parts by weight and a cross-linking graft reaction by a seeded emulsion polymerization method, a third step, a polymerization system after the third step is further added, 10 to 90% by weight of an aromatic vinyl monomer, and cyan. Grafting is performed by adding 55 to 185 parts by weight of a monomer mixture consisting of 10 to 40% by weight of vinyl chloride monomer and 0 to 80% by weight of methyl methacrylate (however, the total amount of the monomer mixture is 100% by weight). A method for producing an impact resistant resin, comprising a fourth step of carrying out polymerization.