JP2000178405A - Resin composition and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition having excellent moldability, color tone, balance of impact strength and rigidity, etc., by mixing a vinyl copolymer with a graft copolymer having a water content within a specific range at a specific mixing ratio. SOLUTION: The objective composition contains (A) 10-95 pts.wt. of a vinyl copolymer and (B) 90-5 pts.wt. of a graft copolymer having a water content of 5-60 wt.% at the time of mixing to the component A. Preferably, the component A is produced by polymerizing 20-100 wt.% of an aromatic vinyl monomer, 0-60 wt.% of a vinyl cyanide monomer, 0-80 wt.% of an unsaturated carboxylic acid alkyl ester monomer, etc., and the component B is produced by the graft polymerization of 95-20 pts.wt. of a monomer mixture composed of 10-100 wt.% of an aromatic vinyl monomer, 0-50 wt.% of a vinyl cyanide monomer, 0-80 wt.% of an unsaturated carboxylic acid alkyl ester monomer, etc., in the presence of 5-80 pts.wt. of a rubbery polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a resin composition comprising a vinyl copolymer (A) and a graft copolymer (B), and more particularly to a vinyl copolymer (A) and a rubbery polymer. The present invention relates to an impact-resistant resin composition comprising a graft copolymer (B) obtained by copolymerizing a monomer and a method for producing the same. More specifically, the present invention relates to an impact-resistant resin composition excellent in moldability, color tone, physical property balance between impact resistance and rigidity, and a method for producing the same.

[0002]

2. Description of the Related Art Impact-resistant resins containing rubber components such as ABS and high-impact polystyrene have excellent balance between various physical properties and moldability.
It is used in a wide range of applications such as automotive parts, electrical equipment parts and office equipment parts.

[0003] In these impact-resistant resins containing a rubber component, it is necessary to graft-polymerize the rubber component in order to exhibit sufficient mechanical properties, and a conventional production method is emulsion graft polymerization. However, the emulsion polymerization method has a problem that the cost is increased due to many steps and a large number of auxiliary materials, and furthermore, wastewater treatment is required. Therefore, in order to reduce the problems of the emulsion polymerization, a method of melt-blending a high rubber-containing polymer obtained by emulsion graft polymerization and a polymer obtained by suspension polymerization or continuous bulk polymerization containing no rubber has been developed ( The Society of Polymer Science, "AB
S resin "), and a process of continuous bulk polymerization of an impact-resistant resin directly containing rubber has also been put into practical use (for example, Japanese Patent Publication No. 47-14136, Japanese Patent Publication No. 49-26).
711, Chemical Engineering 53 (6) 423-426 (1
989)).

[0004]

However, after obtaining a high rubber-containing polymer obtained by emulsion graft polymerization and a polymer obtained by a continuous bulk polymerization method or a suspension polymerization method containing no rubber as an isolated polymer, The method of melt blending has the advantage that the physical properties can be controlled relatively smoothly, but the color tone is not sufficient because the heat history is further received during melt blending, and the balance of physical properties between impact resistance and rigidity is not sufficient. There are drawbacks. In particular, when simply blended, the dispersion of the rubber-containing polymer becomes insufficient and the impact resistance tends to become insufficient. On the other hand, the method of producing an impact-resistant resin directly containing rubber by a continuous bulk polymerization method is the most excellent in that there are few steps and auxiliary materials and that wastewater treatment is unnecessary, but the method of producing a graft polymerization reaction in the bulk polymerization is not required. There are drawbacks in that the control is difficult and the color tone and impact resistance are not sufficient because the rubber component receives more heat history.

[0005] From the viewpoint of product safety, it has been necessary to reduce the amount of unreacted monomers of the ABS resin. However, the conventional technology has limitations, and a large amount of equipment investment is required to change the process. Therefore, it is necessary to develop a more efficient removal method.

[0006]

The present invention relates to a resin composition comprising 10 to 95 parts by weight of a vinyl copolymer (A) and 90 to 5 parts by weight of a graft copolymer (B). A resin composition characterized in that the graft copolymer (B) has a water content of 5% by weight or more and 60% by weight or less when mixed with the union (A), and a method for producing the same.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As the graft copolymer (B) used in the present invention, a graft copolymer obtained by copolymerizing a vinyl monomer with a rubbery polymer is preferable.

[0008] The vinyl monomer mixture constituting the vinyl copolymer (A) and the graft copolymer (B) used in the present invention comprises an aromatic vinyl monomer, a vinyl cyanide monomer, It is preferably at least one vinyl monomer selected from unsaturated carboxylic acid alkyl ester monomers and other vinyl monomers copolymerizable therewith, and is preferably an aromatic vinyl monomer. A monomer mixture containing a body as an essential component is particularly preferably used.

The aromatic vinyl monomer constituting the vinyl copolymer (A) and the graft copolymer (B) used in the present invention is an aromatic compound having a polymerizable double bond. Examples include styrene, α-methylstyrene,
Examples include p-methylstyrene, vinyltoluene, propylstyrene, butylstyrene and cyclohexylstyrene. These aromatic vinyls may be used alone or in combination.
Used in mixtures of more than one species. Of these aromatic vinyl monomers, styrene and α-methylstyrene are particularly preferably used.

The vinyl cyanide monomer constituting the vinyl copolymer (A) and the graft copolymer (B) used in the present invention is a compound having a polymerizable double bond and a cyano group. Specific examples include acrylonitrile and methacrylonitrile. These vinyl cyanide monomers are used alone or in a mixture of two or more. Among these vinyl cyanide monomers,
Acrylonitrile is particularly preferably used.

The unsaturated carboxylic acid alkyl ester monomer constituting the vinyl copolymer (A) and the graft copolymer (B) used in the present invention has a polymerizable double bond and a carboxyl group. It is an alkyl ester compound of a vinyl carboxylic acid. Generally, an α, β-unsaturated carboxylic acid alkyl ester is often used. Among them, alkyl acrylate monomers and alkyl methacrylate monomers are exemplified. The alkyl group having an ester bond may have a functional group such as a glycidyl group or a hydroxyalkyl group in addition to a methyl group, an ethyl group, and a butyl group. Specific examples include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, glycidyl methacrylate, hydroxyethyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate,
And butyl acrylate. These unsaturated carboxylic acid alkyl ester monomers are used alone or in a mixture of two or more. Among these unsaturated carboxylic acid alkyl ester-based monomers, alkyl (meth) acrylate is preferred, and specifically, methyl methacrylate is particularly preferably used.

The other vinyl monomers constituting the vinyl copolymer (A) and the graft copolymer (B) used in the present invention include, for example, N-phenylmaleimide, N-cyclohexylmaleimide, methyl-substituted N- Examples include phenylmaleimide, maleic anhydride, acrylic acid, and methacrylic acid. Among them, N-phenylmaleimide is particularly preferably used.

The rubbery polymer constituting the graft copolymer (B) used in the present invention is a diene rubber, an acrylic rubber, an ethylene rubber or the like, and specific examples thereof include polybutadiene and poly (butadiene). Styrene), poly (butadiene-acrylonitrile), polyisoprene,
Poly (butadiene-butyl acrylate), poly (butadiene-methyl acrylate), poly (butadiene-methyl methacrylate), poly (butadiene-ethyl acrylate), ethylene-propylene rubber, ethylene-propylene diene rubber, poly ( Ethylene-isobutylene), poly (ethylene-methyl acrylate), poly (ethylene-methyl acrylate) and the like. These rubbery polymers are used in one kind or in a mixture of two or more kinds. Among these rubbery polymers, polybutadiene, poly (butadiene-styrene), poly (butadiene-acrylonitrile) and ethylene-propylene rubber are particularly preferably used.

Preferred examples of the vinyl copolymer (A) used in the present invention include polystyrene, styrene-acrylonitrile copolymer, styrene-N-phenylmaleimide copolymer, styrene-acrylonitrile-methyl methacrylate copolymer, A styrene-methyl methacrylate copolymer is mentioned, and among them, a styrene-acrylonitrile copolymer is particularly preferably used.

Preferred examples of the graft copolymer (B) used in the present invention include a styrene graft copolymer of polybutadiene, a styrene graft copolymer of poly (butadiene-styrene), and a styrene-acrylonitrile graft copolymer of polybutadiene. Styrene-acrylonitrile graft copolymer of poly (butadiene-styrene),
Examples thereof include a styrene-acrylonitrile graft copolymer of poly (butadiene-acrylonitrile), a styrene-acrylonitrile-methyl methacrylate graft copolymer of polybutadiene, and a styrene-acrylonitrile graft copolymer of poly (ethylene-propylene).

Further, the resin composition of the present invention may be a transparent resin composition. Although not particularly limited, in the case of a resin composition having transparency, a haze value as an index of transparency is preferably 0 to 15%, more preferably 0 to 13%. In this case, the method for measuring the haze value is as described in the examples (note: however, the haze value depends on the shape and thickness of the sample, and can be compared only under specific conditions).

In the case of a transparent impact-resistant resin composition, particularly preferred examples of the vinyl copolymer (A) include a styrene-acrylonitrile-methyl methacrylate copolymer and a graft copolymer (B A particularly preferred example of the above) is a styrene-acrylonitrile-methyl methacrylate graft copolymer of polybutadiene.

Among them, particularly, the proportion of each monomer of the vinyl copolymer (A) is determined from the viewpoint of the mechanical strength, color tone and moldability of the obtained resin composition. -100% by weight, vinyl cyanide monomer 0-6
0% by weight, 0 to 80% by weight of an unsaturated carboxylic acid alkyl ester monomer and 0 to 60% by weight of another vinyl monomer copolymerizable therewith, more preferably aromatic vinyl. 30 to 100% by weight of a vinyl monomer, 0 to 50% by weight of a vinyl cyanide monomer, 0 to 70% by weight of an unsaturated carboxylic acid alkyl ester monomer, and other vinyl monomers copolymerizable therewith. Mers 0-5
0% by weight, more preferably 60 to 100% by weight of an aromatic vinyl monomer and 10 to 10% by weight of a vinyl cyanide monomer.
40% by weight, 0 to 60% by weight of an unsaturated carboxylic acid alkyl ester monomer and 0 to 40% by weight of another vinyl monomer copolymerizable therewith.

However, in the case of a resin composition having transparency, each monomer of the vinyl copolymer (A) is adjusted so that the refractive index of the vinyl copolymer (A) substantially matches the rubbery polymer. It is preferable to adjust the use ratio of the monomer. As a specific range, it is preferable to suppress the difference in refractive index between the vinyl copolymer (A) and the rubbery polymer to 0.03 or less. More preferably, it is suppressed to 0.01 or less. Also,
The difference in refractive index between the graft component constituting the graft copolymer (B) and the rubbery polymer is within 0.03, particularly 0.01.
It is preferable to be within.

Specifically, when used in a resin composition having transparency, the proportion of each monomer of the vinyl copolymer (A) is 5 to 70% by weight of an aromatic vinyl monomer, 0 to 35% by weight of a vinylated monomer, 30 to 95% by weight of an unsaturated carboxylic acid alkyl ester monomer and 0 to 50% by weight of another vinyl monomer copolymerizable therewith. Preferably, more preferably, 5 to 55% by weight of an aromatic vinyl monomer, and 0 to 25 vinyl cyanide monomers.
% By weight, unsaturated carboxylic acid alkyl ester monomer 4
It is 5 to 95% by weight and 0 to 40% by weight of other vinyl monomers copolymerizable therewith.

As the step of producing the vinyl copolymer (A) in the molten state used in the present invention, a continuous bulk polymerization method is preferably used. Continuous bulk polymerization of a monomer mixture consisting of an aromatic vinyl monomer, a vinyl cyanide monomer, an unsaturated carboxylic acid alkyl ester monomer and another vinyl monomer copolymerizable therewith. In that case, there is no limitation on the method, and any continuous bulk polymerization method can be adopted.

For example, a method is known in which polymerization is performed in a polymerization tank and then demonomerization (devolatilization) is performed. As the polymerization tank, various types of stirring blades, for example, a paddle blade, a turbine blade, a propeller blade, a bulmar blade, a multistage blade, an anchor blade, a max blend blade, a double helical blade, a mixed type polymerization tank having a A tower type reactor or the like can be used. Furthermore, multi-tube reactors, kneader type reactors,
A twin-screw extruder or the like can also be used as a polymerization reactor (Assessment of polymer production process 10 “Assessment of impact-resistant polystyrene”: Society of Polymer Science, 1989)
January 26, year). These polymerization tanks (reactors)
It is used in a base (tank) or in two or more (tanks), and if necessary, a combination of two or more reactors is also used.

The reaction mixture of the vinyl copolymer (A) polymerized in these polymerization tanks or reactors usually contains monomers and other volatile components and needs to be removed.
In the present invention, as a method for removing unreacted monomers, it is preferable to remove volatile components from the vent holes under heating at normal pressure or reduced pressure using a single-screw or twin-screw extruder having a vent. However, a method of removing volatile components with an evaporator having a plate fin type heater such as a centrifugal type built in a drum before supplying to the extrusion device, a method of removing volatile components with a thin film evaporator such as a centrifugal type, etc. Using a tube heat exchanger to remove residual heat, foam, flash to a vacuum tank, remove volatile components, etc.
Either method can be used.

The continuous bulk polymerization of the vinyl copolymer (A) can be performed by thermal polymerization without using an initiator, by initiator polymerization using an initiator, or by thermal polymerization and initiator polymerization. It is also possible to use them together. As the initiator, a peroxide or an azo compound is used.

Specific examples of the peroxide include benzoyl peroxide, cumene hydroperoxide, dicumyl peroxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide, t-butyl hydroperoxide and t-butyl hydroperoxide.
-Butylcumyl peroxide, t-butylperoxyacetate, t-butylperoxybenzoate, t-
Butyl peroxyisopropyl carbonate, di-t-
Butyl peroxide, t-butyl peroctate,
1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, t-butylperoxy-2
-Ethylhexanoate and the like. Among them, cumene hydroperoxide and 1,1-bis (t-
Butylperoxy) 3,3,5-trimethylcyclohexane is particularly preferably used. Specific examples of the azo compound include azobisisobutyronitrile and azobis (2,
4-dimethylvaleronitrile), 2-phenylazo-2,
4-dimethyl-4-methoxyvaleronitrile, 2-cyano-2-propylazoformamide, 1,1'-azobiscyclohexane-1-carbonitrile, azobis (4
-Methoxy-2,4-dimethylvaleronitrile), dimethyl 2,2'-azobisisobutyrate, 1-tert-butylazo-1-cyanocyclohexane, 2-tert-butylazo-2-cyanobutane, 2-tert-butylazo -2-cyano-4-methoxy-4-methylpentane and the like. When using these initiators, one type or two or more types are used in combination. Among them, 1,1'-azobiscyclohexane-1-carbonitrile is particularly preferably used.

For the purpose of controlling the degree of polymerization of the vinyl copolymer (A) used in the present invention, it is possible to use a chain transfer agent such as mercaptan or terpene. Specific examples thereof include n-octyl mercaptan, t-dodecyl mercaptan, n-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, terpinolene, and the like. When these chain transfer agents are used, one type or two or more types are used in combination.
Among them, n-octyl mercaptan, t-dodecyl mercaptan and n-dodecyl mercaptan are particularly preferably used.

Although the vinyl copolymer (A) used in the present invention is produced by a continuous bulk polymerization method, it can be polymerized using a small amount (for example, 20% by weight or less) of a solvent. It is included in the scope of the present invention.

The graft copolymer (B), which is the other component used in the present invention, is obtained by adding an aromatic vinyl monomer, a vinyl cyanide monomer and an unsaturated carboxylic acid to a rubbery polymer. It is preferable that the copolymer is obtained by subjecting a monomer mixture composed of an alkyl ester monomer and another vinyl monomer copolymerizable therewith to an emulsion graft polymerization reaction. And usually those obtained as a mixture with an ungrafted copolymer are used.

Although the graft ratio of the graft copolymer (B) is not limited, it is preferably 5 to 150%, more preferably 10 to 100%. The graft ratio is determined by the following formula after drying the graft copolymer (B), dissolving with acetone, isolating and weighing insolubles. Graft ratio (%) = (acetone-insoluble content−weight of rubbery polymer) / weight of rubbery polymer × 100 The ratio of the rubbery polymer in the graft copolymer (B) is determined by the mechanical properties of the obtained resin composition. From the viewpoints of strength, color tone and moldability, the amount is preferably 5 to 80 parts by weight, more preferably 20 to 70 parts by weight. The proportion of each monomer other than the rubbery polymer of the graft copolymer (B) is 10 to 100% by weight of an aromatic vinyl monomer,
0 to 50% by weight of a vinyl cyanide monomer, 0 to 80% by weight of an unsaturated carboxylic acid alkyl ester type monomer and 0 to 60% by weight of another vinyl monomer copolymerizable therewith are preferable. More preferably, the aromatic vinyl monomer is 60 to 100% by weight, and the vinyl cyanide monomer is 10 to 10% by weight.
40% by weight, 0 to 60% by weight of an unsaturated carboxylic acid alkyl ester monomer and 0 to 40% by weight of another vinyl monomer copolymerizable therewith.

In the case of an impact-resistant resin composition having transparency, the ratio of the rubbery polymer in the graft copolymer (B) depends on the mechanical strength, color tone and moldability of the obtained resin composition. From the viewpoint, it is preferably 5 to 80 parts by weight, more preferably 20 to 70 parts by weight. The proportion of each monomer other than the rubbery polymer used is 5 to 70% by weight of an aromatic vinyl monomer, 0 to 35% by weight of a vinyl cyanide monomer, and an unsaturated carboxylic acid alkyl ester monomer. 30 to 95% by weight of the polymer and other vinyl monomers copolymerizable therewith
It is preferably 50% by weight, more preferably 5 to 55% by weight of an aromatic vinyl monomer and 0 to 2 of a vinyl cyanide monomer.
5% by weight.

The graft copolymer (B) is preferably produced by emulsion polymerization. Emulsion polymerization usually involves emulsion graft polymerization of a monomer mixture in the presence of a rubbery polymer latex. The emulsifier used in the emulsion graft polymerization is not particularly limited, and various surfactants can be used. Anionic surfactants such as carboxylate type, sulfate type, and sulfonate type are particularly preferably used. You. Specific examples of such an emulsifier include caprylate, caprate, laurate, mystyphosphate, palmitate,
Stearate, oleate, linoleate, linolenate, rosinate, behenate, castor oil sulfate, lauryl alcohol sulfate, other higher alcohol sulfate, dodecylbenzene sulfonate, alkyl Naphthalene sulfonate, alkyl diphenyl ether disulfonate, naphthalene sulfonate condensate, dialkyl sulfosuccinate, polyoxyethylene lauryl sulfate, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl phenyl ether sulfate, etc. No. The salt herein refers to an alkali metal salt, an ammonium salt, and the like, and specific examples of the alkali metal salt include a potassium salt, a sodium salt, and a lithium salt. These emulsifiers are used alone or in combination of two or more.

Examples of the initiator and chain transfer agent that can be used in the emulsion graft polymerization include the initiators and chain transfer agents described in the production of the vinyl copolymer (A), and the initiator is redox. Also used in systems.

The graft copolymer (B) latex produced by emulsion graft polymerization is then coagulated by adding a coagulant to recover the graft copolymer (B). Acid or water-soluble salt is used as a coagulant, and as a specific example,
Sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid, calcium chloride, magnesium chloride, barium chloride, aluminum chloride, magnesium sulfate, aluminum sulfate, aluminum ammonium sulfate, aluminum potassium sulfate, aluminum sodium sulfate, and the like. These coagulants are used in one kind or in a mixture of two or more kinds.

In the present invention, when the graft copolymer (B) is mixed with the vinyl copolymer (A), the water content must be 5% by weight or more and 60% by weight or less. Preferably 1
0 to 50% by weight.

Here, the moisture content is obtained by the following formula by weighing the dry weight of the graft copolymer (B) after drying at 80 ° C. and under vacuum for 4 hours. Moisture percentage (weight%) = (weight before drying (g)-
Weight after drying (g)] / [Weight after drying (g)] * 100
If the amount is more than 10% by weight, it becomes difficult to remove water stably with an extruder, and as a result, it becomes impossible to effectively remove unreacted monomers and the strength is reduced. Further, even if the content is less than 5% by weight, the unreacted monomer in the resin cannot be sufficiently removed, and the color tone and the impact strength are adversely affected. By adjusting the water content to 5% by weight or more and 60% by weight or less, the unreacted monomer of the resin composition can be effectively removed, and the content can be reduced to 2000 ppm or less. Things.

The method for adjusting the water content of the graft polymer is not particularly limited. After coagulation, it may be filtered with a cloth or the like before addition. Further, the moisture content may be reduced by using a centrifugal dehydrator. The continuous addition device for supplying the graft copolymer (B) to the extruder is provided with grooves / holes or gaps for allowing the liquid material to pass therethrough and a vent hole to remove water before supplying the extruder to reduce the water content. However, it is necessary to adjust the water content to the above range immediately before mixing with the vinyl copolymer (A) in a molten state.

In the present invention, a graft copolymer (B) having a specific range of water content is added to the vinyl copolymer (A),
It is necessary to mix, and a resin composition excellent in color tone, impact resistance and the like can be obtained only by reducing unreacted monomers. At that time, it is necessary to add 90 to 5 parts by weight (in terms of dry weight) of the graft copolymer (B) to 10 to 95 parts by weight of the vinyl copolymer (A) in a molten state. . Preferably, vinyl copolymer (A) 3
The graft copolymer (B) is 70 to 5 parts by weight (in terms of dry weight) based on 0 to 95 parts by weight.

When the amount of the graft copolymer (B) is less than 5 parts by weight, the resin composition is inferior in impact resistance, and the residual amount of unreacted monomer increases. On the other hand, when the amount exceeds 90 parts by weight, the color tone and the like of the resin composition deteriorate, and the balance of physical properties deteriorates.

At this time, the addition of the graft copolymer (B) is not required during the de-monomerization step or after the de-monomerization step of the (bulk) polymerization process of the vinyl copolymer (A). If it is carried out at a point of not more than 5% by weight, more preferably at most 5% by weight, the rubber component does not deteriorate due to heat history during the subsequent operation of removing the monomer, and the color tone and impact resistance characteristic of the present invention are This is preferable since the properties and the like are further improved. In the present invention, the mixing after continuously adding the graft copolymer (B) to the vinyl copolymer (A) is performed by melt-mixing so that physical properties such as impact resistance can be sufficiently exhibited. Also preferred.

The method for adding the graft copolymer (B) is not particularly limited, and it is possible to add it by any method. Usually, a method of using a variety of feeders, for example, a belt-type feeder or a screw-type feeder, and adding a fixed amount to a single-screw extruder and a twin-screw extruder is preferably used. Further, the continuous addition device has a heating device, and it is preferable to add the graft copolymer (B) in a semi-molten or molten state because the mixing state is improved. For this purpose, an extruder having a heating device can be used.

This continuous addition device is composed of a screw, a cylinder, and a screw drive unit.
It is preferable to have a cooling capacity.

The cylinder has a groove, a hole or a gap through which a liquid material passes but not a large amount of solids, and / or one or more vent holes. The cylinder may be a single screw extruder or a twin screw extruder. May be. The extruder is supplied with the water-containing graft copolymer (B), compressed by rotation of a screw, and most of the water is discharged from grooves, holes or gaps in the first half of the cylinder (supply side), and / or Water and volatiles can be removed from the vent hole in the heating zone.

The vent holes may be in any form, either at normal pressure or under reduced pressure. Further, two or more vent holes may be used in combination with pressurization, normal pressure and reduced pressure.

Further, when the water carried in the graft copolymer (B) is dehydrated by heating with a demonomerizer, the water removed accompanies the residual monomer, so that it has a great effect on reducing the amount of unreacted monomer. . Also, when a water-containing graft copolymer (B) in which water is uniformly dispersed is used as compared with a separate addition using a pump or the like, the water-containing graft copolymer (B) is sufficiently mixed and dispersed in the molten polymer, so that the unreacted monomer can be efficiently removed It is excellent in terms of proper removal and maintenance of physical properties such as impact resistance.

In the present invention, if necessary, various antioxidants such as phenol, phosphorus, and sulfur, weathering agents such as ultraviolet absorbers and light stabilizers, antistatic agents, ethylenebisstearylamide, A lubricant such as metallic soap, a plasticizer, a coloring agent, a filler, a reinforcing material such as glass fiber and carbon fiber, a flame retardant, and the like can also be blended.

[0046]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.
The percentages and parts used in this example are% by weight and parts by weight, respectively. The YI value of the pellets was measured by a yellowness index (YI value) using a color difference meter manufactured by Suga Test Instruments Co., Ltd. The Izod impact strength is A
STM-D256, tensile strength was measured according to ASTM-D638. The quantification of the unreacted monomer content was measured by gas chromatography. The refractive index was measured by dropping a small amount of 1-bromonaphthalene on the sample to be measured and measuring the refractive index using an Abbe refractometer (light source: sodium lamp D line, measurement temperature: 20 ° C.). Transparency (haze value): A square plate formed by immediately filling a pellet of the resin composition dried in an 80 ° C. hot air dryer for 3 hours into an IS50A molding machine manufactured by Toshiba Corp. set at a cylinder temperature of 250 ° C. The haze value [%] of the molded product (thickness: 3 mm) was measured using a direct-read haze meter manufactured by Toyo Seiki Co., Ltd.

Reference Example 1 (Production method of graft copolymer) 50 parts (in terms of solid content) of polybutadiene latex (rubber particle type 0.3 μm, gel content 85%), 200 parts of pure water,
Sodium formaldehyde sulfoxylate 0.4
Parts, sodium ethylenediaminetetraacetate (0.1 part), ferrous sulfate (0.01 part) and sodium phosphate (0.1 part) were charged into a reaction vessel. , Acrylonitrile 15 parts and n-
A mixture of 0.3 parts of dodecyl mercaptan was continuously added dropwise over 4 hours. At the same time, a mixture of 0.25 part of cumene hydroperoxide, 2.5 parts of sodium laurate as an emulsifier and 25 parts of pure water was continuously added dropwise over 5 hours, and after the completion of the addition, the mixture was further maintained for 1 hour to carry out polymerization. Finished.

The latex after polymerization was coagulated with 1.5% sulfuric acid, then neutralized with an alkali, washed and centrifuged to prepare a graft copolymer cake (B-1). The graft ratio of the obtained graft copolymer cake (B-1) was 45%. The water content determined from the loss on drying of the sample was 25%.

The obtained (B-1) was dried with hot air and blended with (B-2) having a water content of 0.5% and water by adding water to (B-1) to obtain a water content of 65%. (B-3) was prepared.

Reference Examples 2 to 8 (Method for Producing Graft Copolymer) In the same manner as in Reference Example 1, styrene and other vinyl monomers were added in the presence of the rubbery polymers shown in Tables 1 and 2. Was polymerized to produce graft copolymer cakes (B-4 to 9, 12) having the compositions shown in Tables 1 and 2. Note that PBD in Tables 1 and 2 represents the same polybutadiene rubber used in Reference Example 1. (B-9) is dried with hot air, (B-10) having a moisture content of 0.5% and (B-9) are mixed with water by adding water, and (B-11) having a moisture content of 65% is obtained. Prepared.

[Table 1]

[Table 2]

Example 1 A completely mixed type reaction tank having helical ribbon blades, a preheater, a demonomerizer, and 1 /
Using a continuous bulk polymerization apparatus consisting of a twin-screw extruder-type feeder having a heating device connected to a three-length barrel section in tandem, a single unit consisting of 70 parts of styrene, 30 parts of acrylonitrile and 0.15 part of n-octylmercaptan. The monomer mixture was continuously supplied at 150 kg / h to perform continuous bulk polymerization.

The polymerization rate of the polymer discharged from the polymerization tank is 75 to 7
The operation was controlled between 6%. In the polymerization reaction mixture, unreacted monomers are recovered by evaporation under reduced pressure from a vent port by a single-screw extruder-type demonomer machine, and an apparent polymerization rate becomes 99% or more at one-third of the end of the demonomer machine. Rose. The styrene / acrylonitrile copolymer was fed from a twin-screw extruder type feeder with 0.15 kg / h of t-butylhydroxytoluene as a phenol-based stabilizer and 0.15 kg of tri (nonylphenyl) phosphite as a phosphorus-based stabilizer.
/ H, the graft copolymer cake (B-1) produced in Reference Example 1 was continuously supplied at a rate of 87 kg / h, melt-kneaded with the styrene / acrylonitrile copolymer by the demonomerizer, and then subjected to strand kneading. The styrene-based resin composition pellets were obtained by using a cutter. Table 3 shows the properties of the obtained styrenic resin composition.

Examples 2 to 8 The graft copolymer cakes (B-
4 to 8) were supplied under the conditions shown in Table 3, and produced in the same manner as in Example 1.

Table 2 shows the properties of the obtained styrenic resin composition. As can be seen from Table 3, the styrenic resin composition produced by the method of the present invention was excellent in both color tone and physical properties.

Comparative Examples 1-4 The graft copolymer cakes (B-1 to B-1) produced in Reference Example 1
3) was supplied under the conditions shown in Table 3, and produced in the same manner as in Example 1. Table 3 shows the properties of the obtained styrenic resin composition.

[Table 3]

Examples 9 to 10 and Comparative Examples 5 to 6 The graft copolymer cakes (B-
9 to 12) were supplied under the conditions shown in Table 4, and were produced in the same manner as in Example 1.

Table 4 shows the properties of the obtained styrenic resin composition. As can be seen from Table 4, the styrene resin composition produced by the method of the present invention was excellent in color tone, physical properties and transparency.

[Table 4]

Examples 11 to 12 Among the production methods of Example 1, a twin-screw extruder to which a graft copolymer cake was continuously added, provided with a slit barrel, was used. The test was performed under the following conditions. The amount of dehydration in Table 5 is obtained by quantifying the amount of water discharged from the slit barrel, and is described as the amount of dehydration (kg / h). In addition, the residual moisture content indicates the moisture content brought in when melt-kneading with the acrylonitrile / styrene copolymer, which is calculated by the following equation.

[Table 5]

(Equation 1)

[0059]

Examples 1 to 8, 11 and 12 were excellent in color tone, physical properties and unreacted monomer content.
Examples 9 to 10 were excellent in color tone, physical properties, unreacted monomer content, and transparency.

On the other hand, Comparative Examples 1 and 5 had poor pellet color tone, and Comparative Examples 2 and 6 exhibited the graft copolymer (B-3, 1).
Because of the large amount of water brought in 1), stable production was not possible.
As a result, physical properties were not stable. Comparative Example 4 was unfavorable because of poor color tone and physical property balance.

Claims (13)

[Claims] 1. A resin composition comprising 10 to 95 parts by weight of a vinyl copolymer (A) and 90 to 5 parts by weight of a graft copolymer (B) when mixed with the vinyl copolymer (A). Wherein the graft copolymer (B) has a water content of 5% by weight or more and 60% by weight or less. 2. A thermoplastic resin comprising 10 to 95 parts by weight of a vinyl copolymer (A) and 90 to 5 parts by weight of a graft copolymer (B) obtained by copolymerizing a vinyl monomer with a rubbery polymer. An impact-resistant resin composition, characterized in that the graft copolymer (B) has a moisture content of from 5% by weight to 60% by weight when mixed with the vinyl copolymer (A). 3. The resin composition according to claim 1, wherein the content of the unreacted monomer is 2,000 ppm or less. 4. A vinyl copolymer (A) comprising 20 to 100% by weight of an aromatic vinyl monomer, 0 to 60% by weight of a vinyl cyanide monomer, and an unsaturated carboxylic acid alkyl ester monomer. A polymer obtained by polymerizing a vinyl monomer mixture consisting of 0 to 80% by weight of a copolymer and 0 to 60% by weight of another vinyl monomer copolymerizable therewith, and a graft copolymer ( B) is an aromatic vinyl monomer in an amount of 10 to 100% by weight, a vinyl cyanide monomer in an amount of 0 to 50% by weight and an unsaturated carboxylic acid alkyl ester in the presence of 5 to 80 parts by weight of a rubbery polymer. It is obtained by graft polymerization of 95 to 20 parts by weight of a monomer mixture consisting of 0 to 80% by weight of a monomer and 0 to 60% by weight of another vinyl monomer copolymerizable therewith. Claim 1 to claim
4. The resin composition according to any one of 3. 5. The resin composition according to claim 1, wherein the rubbery polymer of the graft copolymer (B) is a diene rubber. 6. The vinyl copolymer (A) is a styrene-acrylonitrile copolymer, and the graft copolymer (B)
Is a graft copolymer obtained by graft copolymerizing styrene-acrylonitrile with a rubbery polymer. The resin composition according to any one of claims 1 to 5, wherein 7. A vinyl copolymer (A) comprising 5 to 70% by weight of an aromatic vinyl monomer and 0 to 3 of a vinyl cyanide monomer.
Continuous bulk polymerization of a vinyl monomer mixture consisting of 5% by weight, 30 to 95% by weight of an unsaturated carboxylic acid alkyl ester monomer and 0 to 50% by weight of another vinyl monomer copolymerizable therewith. And the graft copolymer (B) is obtained in the presence of 5 to 80 parts by weight of a rubbery polymer.
70% by weight, 0 to 35% by weight of a vinyl cyanide monomer and 30 to 30% of an unsaturated carboxylic acid alkyl ester monomer
95 to 2% of a monomer mixture consisting of 95% by weight and 0 to 50% by weight of other vinyl monomers copolymerizable therewith.
The transparent impact-resistant resin composition according to any one of claims 1 to 3, which is a graft copolymer obtained by emulsion graft polymerization of 0 parts by weight. 8. The impact-resistant resin having transparency according to claim 2, wherein the difference in refractive index between the vinyl copolymer (A) and the rubbery polymer is within 0.03. Resin composition. 9. The method according to claim 2, wherein the difference in refractive index between the graft component constituting the graft copolymer (B) and the rubbery polymer is within 0.03. An impact-resistant resin composition having transparency. 10. A polymer obtained by subjecting 10 to 95 parts by weight of a vinyl copolymer (A) in a molten state obtained by continuous bulk polymerization to polymerization by an emulsion graft polymerization method, followed by coagulation with an inorganic salt or an inorganic acid. Graft copolymer (B) 9 to be obtained
In a method for producing a resin composition in which 0 to 5 parts by weight is continuously supplied to an extruder and mixed, the water content of the graft copolymer (B) when mixed with the vinyl copolymer (A) is 5%. Not less than 60% by weight, and mixing the vinyl copolymer (A) and the graft copolymer (B),
The method for producing a resin composition according to claim 1, wherein water is removed. 11. A molten vinyl copolymer (A) obtained by subjecting a vinyl monomer mixture containing at least an aromatic vinyl monomer to continuous bulk polymerization, in an amount of 10 to 95 parts by weight; A graft copolymer (B) 90 obtained by polymerizing a vinyl monomer mixture containing at least an aromatic vinyl monomer in the presence of a polymer by an emulsion graft polymerization method, and then coagulating the mixture with an inorganic salt or an inorganic acid. ５5 parts by weight are continuously supplied to an extruder and mixed, and in the method for producing an impact-resistant resin composition, the moisture content of the graft copolymer (B) when mixed with the vinyl copolymer (A) Is not less than 5% by weight and not more than 60% by weight, and the vinyl copolymer (A) and the graft copolymer (B) are mixed to remove water. Impact resistant tree described in any of them Processes for making compositions. 12. The graft copolymer (B) is added to and mixed with the vinyl copolymer (A) during or after the demonomerization step of the continuous bulk polymerization of the vinyl copolymer (A). The method for producing a resin composition according to any one of claims 10 to 11, wherein: 13. A mono- or twin-screw extruder with a vent in the demonomerization step of the continuous bulk polymerization of the vinyl copolymer (A), and a continuous addition apparatus for the graft copolymer (B) is used. 13. A single-screw or twin-screw extruder connected to the unionized (A) demonomer extruder.
The method for producing a resin composition according to any one of the above.