JP3109378B2 - Method for producing impact-resistant resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an impact-resistant resin composition. More specifically, the present invention relates to a method for producing an impact-resistant resin composition having excellent color tone and excellent balance between physical properties of impact resistance and rigidity.

[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. Conventionally, the production method has been emulsion graft polymerization. However, the emulsion polymerization method involves many steps and has a large number of auxiliary materials, which increases the cost,
In addition, there is a problem that wastewater treatment is required. Therefore, in order to reduce such problems of emulsion polymerization, a method of melt-blending a high rubber-containing polymer obtained by emulsion graft polymerization and a polymer obtained by suspension polymerization containing no rubber has been developed (polymers). (ABS Resin, edited by the Society). Further, in recent years, a process of directly bulk polymerizing an impact resin containing rubber directly has been put into practical use (for example, Japanese Patent Publication No. 47-14136, Japanese Patent Publication No. 49-26711, Chemical Engineering 53 (6)). 423-426 (1989)).

[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. 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 is poor because the rubber component receives more heat history. Furthermore, it is not always satisfactory in terms of physical properties such as impact resistance. Further, when the rubber component is increased, there is a disadvantage in that a deteriorated product of the rubber stays in the apparatus or the rubber is peeled off, which causes a problem in production and quality.

[0005]

Means for Solving the Problems The present inventors have developed a color tone and
Shock resistance with excellent physical balance between impact resistance and rigidity
As a result of earnestly studying a method for producing a conductive resin composition, the present invention has been achieved. That is, the present invention provides an aromatic vinyl monomer 2
0 to 100% by weight, 0 to 60% by weight of a vinyl cyanide monomer, 0 to 80% by weight of a (meth) acrylate monomer and 0 to other vinyl monomers copolymerizable therewith 10 to 95 parts by weight of a copolymer (A) obtained by continuous bulk polymerization of a monomer mixture of 60% by weight, and aromatic vinyl monomer 1 in the presence of 5 to 80 parts by weight of a rubbery polymer
0 to 100% by weight, 0 to 50% by weight of a vinyl cyanide monomer and 0 to 8 of a (meth) acrylate monomer
0 to 20% by weight of a monomer mixture composed of 0 to 60% by weight of another vinyl monomer copolymerizable therewith.
Graft copolymer (B) 90 obtained by graft polymerization of parts by weight
In a method for producing an impact-resistant resin composition comprising from 5 to 5 parts by weight, a graft copolymer (B) previously dehydrated and dried is continuously added to a copolymer (A) in a molten state during a process of continuous bulk polymerization. And a method for producing an impact-resistant resin composition characterized by being added to and mixed with a resin.

[0006] The aromatic vinyl monomer constituting the copolymer (A) and the graft copolymer (B) used in the present invention is an aromatic compound having a polymerizable double bond. Styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, propylstyrene, butylstyrene and cyclohexylstyrene. These aromatic vinyl monomers 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-based monomer constituting the copolymer (A) and the graft copolymer (B) used in the present invention is a compound having a polymerizable double bond and a cyano group. , Acrylonitrile and methacrylonitrile. These vinyl cyanide monomers are used alone or in a mixture of two or more. Of these vinyl cyanide monomers, acrylonitrile is particularly preferably used.

Specific examples of the (meth) acrylate monomers constituting the copolymer (A) and the graft copolymer (B) used in the present invention include methyl methacrylate and methyl methacrylate.
Examples include ethyl methacrylate, propyl methacrylate, butyl methacrylate, glycidyl methacrylate, hydroxyethyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate and the like. These (meth) acrylate monomers are used alone or as a mixture of two or more. Of these (meth) acrylate monomers, methyl methacrylate is particularly preferably used. Other vinyl monomers constituting the copolymer (A) and the graft copolymer (B) used in the present invention include, for example, N-phenylmaleimide, N-cyclohexylmaleimide, methyl-substituted N-phenylmaleimide, and maleic anhydride. Examples include acid, 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 copolymer (A) used in the present invention include polystyrene, styrene-acrylonitrile copolymer, styrene-N-phenylmaleimide copolymer, styrene-acrylonitrile-methyl methacrylate copolymer, styrene- A methyl methacrylate copolymer is mentioned, and a styrene-acrylonitrile copolymer is particularly used.

Preferred examples of the graft copolymer (B) used in the present invention include styrene graft polymer of polybutadiene, styrene graft polymer of poly (butadiene-styrene), styrene-acrylonitrile graft copolymer of polybutadiene, and poly ( Butadiene-styrene)
Styrene-acrylonitrile graft copolymer, poly (butadiene-acrylonitrile) styrene-acrylonitrile graft copolymer, polybutadiene styrene-acrylonitrile-methyl methacrylate graft copolymer, poly (ethylene-propylene) styrene-acrylonitrile graft copolymer Polymers. Among them, especially the usage ratio of each monomer of the copolymer (A) is as follows:
From the viewpoints of mechanical strength, color tone and moldability of the obtained resin composition, 20 to 100% by weight of an aromatic vinyl monomer,
0 to 60% by weight of a vinyl cyanide monomer, 0 to 80% by weight of a (meth) acrylate monomer and 0 to 60% by weight of another vinyl monomer copolymerizable therewith. There is. Preferably aromatic vinyl monomer 30
To 100% by weight, 0 to 50% by weight of a vinyl cyanide monomer, 0 to 70% by weight of a (meth) acrylate monomer and 0 to 50 of other vinyl monomers copolymerizable therewith. % By weight, more preferably 60 to 100% by weight of an aromatic vinyl monomer, and 1
0 to 40% by weight, 0 to 60% by weight of a (meth) acrylate monomer and 0 to 40% by weight of another vinyl monomer copolymerizable therewith.

The first step of the present invention, namely, 20 to 100% by weight of an aromatic vinyl monomer, 0 to 60% by weight of a vinyl cyanide monomer and 0 to 80% by weight of a (meth) acrylate monomer % And a monomer mixture comprising 0 to 60% by weight of other vinyl monomers copolymerizable therewith are not limited to a continuous bulk polymerization method in the step of continuously bulk polymerizing any monomer mixture. Can be adopted.
For example, there is known a method of depolymerizing (degassing) after polymerization in a polymerization tank. As the polymerization tank, various stirring blades, for example, a paddle blade, a turbine blade, a propeller blade, a bulmar blade, a multi-stage blade, an anchor blade, a max blend blade, a double helical blade, etc. A tower type reactor or the like can be used. Furthermore, a multi-tube reactor, a kneader-type reactor, a twin-screw extruder and the like can be used as the polymerization reactor (for example,
Assessment of Polymer Manufacturing Process 10 “Assessment of Impact Polystyrene”: The Society of Polymer Science, 1989, 1
Month 26). These polymerization tanks (reactors) may be used in one (tank) or in two or more (tanks), and may be used in combination of two or more kinds of reactors if necessary.

The reaction mixture of the copolymer (A) polymerized in these polymerization tanks or reactors is usually then subjected to a demonomerization step to remove monomers and other volatile components. As a method of demonomerization, a single-screw or twin-screw extruder with a vent is used to remove volatile components from the vent hole under heating at normal pressure or reduced pressure, and a plate fin type heater such as a centrifugal type is built in a drum and evaporated. A method of removing volatile components with a heat exchanger, a method of removing volatile components with a thin-film evaporator such as a centrifugal type, a method of removing residual components by using a multi-tube heat exchanger, preheating, bubbling and flashing into a vacuum tank And any of these methods can be used. In particular, a single-screw or twin-screw extruder having a vent is preferably used.

In the continuous bulk polymerization of the copolymer (A), thermal polymerization without using an initiator, initiator polymerization using an initiator, or both thermal polymerization and initiator polymerization are used. It is also possible. 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, g-t-
Butyl peroxide, t-butyl peroctate, 1,
Examples thereof include 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 are particularly preferably used. Specific examples of the azo compound include azobisisobutyronitrile, 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-t -Butylazo-1-cyanocyclohexane, 2-t-butylazo-
2-cyanobutane, 2-t-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 copolymer (A) used in the present invention, it is possible to use a chain transfer agent such as mercaptan or terpene.
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 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% or less) of a solvent, and is included in the scope of the present invention. It is.

The graft copolymer (B), which is the other component used in the present invention, is a rubbery polymer of 5-80.
Parts by weight, 10 to 100% by weight of an aromatic vinyl monomer,
A simple composition comprising 0 to 50% by weight of a vinyl cyanide monomer, 0 to 80% by weight of a (meth) acrylate monomer and 0 to 60% by weight of another vinyl monomer copolymerizable therewith. Is a copolymer obtained by subjecting 95 to 20 parts by weight of a monomer mixture to a graft polymerization reaction, but it is not necessary that the entire amount be grafted, and usually, a copolymer obtained as a mixture with an ungrafted copolymer is used. I do. The graft ratio of the graft copolymer (B) is not limited, but is preferably 5-1.
50%, more preferably 10 to 100% by weight is used. Here, the graft ratio is calculated by the following equation. Graft ratio (% by weight) = (weight of graft branch / weight of rubbery polymer) × 100

The proportion of the rubber-like polymer in the graft copolymer (B) is from 5 to 80 parts by weight, more preferably from 20 to 80 parts by weight, from the viewpoint of the mechanical strength, color tone and moldability of the obtained resin composition. 70 parts by weight. Graft copolymer (B)
The use ratio of each monomer other than the rubbery polymer is 10 to 100% by weight of an aromatic vinyl monomer, 0 to 50% by weight of a vinyl cyanide monomer, and a (meth) acrylate ester monomer. 0 to 80% by weight of a monomer and 0 to 60% by weight of another vinyl monomer copolymerizable therewith, and more preferably (1) 60 to 100% by weight of an aromatic vinyl monomer, 10 to 40% by weight of vinyl monomer and (meth)
0% by weight of acrylate monomer, or (2) 20 to 60% by weight of aromatic vinyl monomer, 0 to 30% by weight of vinyl cyanide monomer and (meth) acrylate monomer alone 40-80% by weight of the body.

The method for producing the graft copolymer (B) is not limited, but is preferably produced by emulsion polymerization or bulk polymerization, more preferably 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 emulsifiers include caprylate, caprate, laurate, mystyrate, palmitate, stearate, oleate,
Linoleate, linolenate, rosinate, behenate, castor oil sulfate, lauryl alcohol sulfate, other higher alcohol sulfate, dodecylbenzene sulfonate, alkyl naphthalene sulfonate, alkyl diphenyl Examples include ether disulfonate, naphthalene sulfonate condensate, dialkyl sulfosuccinate, polyoxyethylene lauryl sulfate, polyoxyethylene alkyl ether sulfate, and polyoxyethylene alkylphenyl ether sulfate. 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 the chain transfer agent that can be used in the emulsion graft polymerization include the initiator and the chain transfer agent described in the production of the copolymer (A), and the initiator is also used in a redox system. .

The graft copolymer (B) produced by the emulsion graft polymerization is then added with a coagulant to coagulate the latex 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 solidification ages are used in one or more mixtures. The coagulated graft copolymer (B) is previously dehydrated and dried, and is added to the copolymer (A) in a molten state.

As described above, the graft copolymer (B)
Can also be produced by a bulk polymerization method. In the case of production by the bulk polymerization method, the graft copolymer (B) in a molten state, which has come out of a demonomerizer, can be directly added to the copolymer (A), or it can be isolated in advance. Although the graft copolymer (B) can be added to the copolymer (A), the graft copolymer which is usually in a molten state and exited from the demonomer machine from the viewpoint of preventing thermal deterioration and continuation of the process. More preferably, (B) is added directly.

In the present invention, it is necessary to continuously add the graft copolymer (B) to the copolymer (A) in the molten state during the bulk polymerization process and then to mix them. A resin composition having excellent properties and the like can be obtained. At that time, the copolymer (A) 10 in a molten state
It is necessary to continuously add 90 to 5 parts by weight of the graft copolymer (B) to 95 parts by weight. More preferably, the graft copolymer (B) is added to 30 to 95 parts by weight of the copolymer (A). After continuously adding 70 to 5 parts by weight, they are mixed. At this time, the graft copolymer (B) is added so that the amount of the residual monomer is 10% or less, more preferably 5% or less during or after the demonomerization step of the bulk polymerization process of the copolymer (A). This is preferred because the rubber component does not deteriorate due to heat history during the subsequent demonomerization operation, and the color tone and impact resistance, which are the characteristics of the present invention, are further improved. In the present invention, the mixing after the graft copolymer (B) is continuously added to the copolymer (A) is preferably performed by melt mixing in order to sufficiently develop physical properties such as impact resistance. preferable. This melt mixing may be performed at the time of addition mixing or after isolation of the mixture, for example, at the time of melt molding.

The method for continuously adding the graft copolymer (B) is not particularly limited, and the graft copolymer (B) can be added by any method. Usually, various feeders such as a belt type feeder, a screw type feeder, a single screw extruder and a twin screw extruder are used, but a single screw extruder and a twin screw extruder are particularly preferably used. It is preferable that these continuous addition devices can measure a quantity. 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.

In the present invention, if necessary, various antioxidants such as phenol-based, phosphorus-based, and sulfur-based, 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.

[0024]

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 pellet was measured using a color difference meter manufactured by Suga Test Instruments Co., Ltd. with a yellow index (YI
Value) was measured. The Izod impact strength is ASTM
D256, tensile strength was measured according to ASTM 638.

Reference Example 1 (Production method of graft copolymer) 50 parts of polybutadiene latex (rubber particle type 0.3 μm, gel content 85%) (in terms of solid content), 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 polymerized latex was coagulated with 1.5% sulfuric acid, then neutralized with an alkali, washed, centrifuged, and dried to prepare a graft copolymer (B-1) on the powder. The obtained graft copolymer (B-1) was extracted with MEK, and the graft ratio was 45%.

Reference Examples 2 to 8 (Production Method of Graft Copolymer) In the same manner as in Reference Example 1, a mixture of styrene and other vinyl monomers was polymerized for the presence of various polymers on rubber shown in Table 3. Thus, graft copolymers (B-2 to 8) having the compositions shown in Table 1 were produced. The PBD in Table 1 is the same polybutadiene rubber and SB as used in Reference Example 1.
R is a styrene / butadiene copolymer rubber composed of 25% styrene and 75% butadiene, NBR is an acrylonitrile / butadiene copolymer rubber composed of 25% acrylonitrile and 75% butadiene, EPDM is an iodine value of 23, and Mooney viscosity is 60. Ethylene / propylene / 5-
Represents ethylidene-2-norbonene terpolymer rubber (ethylene / propylene = 68.5 / 31.5 molar ratio).

Reference Example 9 (Production method of graft copolymer) The amount of polybutadiene rubber was changed from 50 parts to 70 parts (in terms of solid content), and the amount of styrene was changed from 35 parts to 21 parts.
A latex was obtained by carrying out a polymerization operation in the same manner as in Reference Example 1, except that the amount of acrylonitrile was changed from 15 parts to 9 parts. Styrene 25 was added to 25 parts of solid content of this latex.
Then, 0.8 parts of magnesium sulfate was added. Only the white polymer / monomer phase (crum) was taken out of the mixed solution, and 29 parts of styrene, 21 parts of acrylonitrile, 0.15 part of n-dodecylmercaptan and 0.03 part of cumene hydroperoxide were added to obtain a uniform solution (raw material dope). did. Next, this raw material dope is provided with a helical ribbon type stirring blade, directly connected to the upper part, a condenser and a stationary separator are installed, water is taken out from the lower phase of the separator to the outside of the polymerization system, and the upper phase is taken out. , Only the monomer was withdrawn and continuously charged into a polymerization tank having a jacket that was refluxed to the polymerization tank. The dope charging rate was such that when the continuous polymerization became steady, the polymerization reaction mixture having a polymer concentration of 75% in the polymerization tank was continuously withdrawn, fed to a twin-screw extruder having a vent port, and vacuumed at 180 to 240 ° C. The residual monomer was removed from the vent port to obtain a graft copolymer (B-9).

REFERENCE EXAMPLE 10 (Production method of graft copolymer) 10 parts of diene NF35A (solid butadiene rubber manufactured by Asahi Kasei Corporation) was dissolved in 90 parts of styrene, followed by continuous bulk polymerization / demonomerization to obtain a rubber content of 15%. Was obtained as a graft copolymer (B-10).

REFERENCE EXAMPLE 11 (Production method of graft copolymer) 10 parts of diene NF35A was dissolved in 90 parts of a monomer mixture composed of 70% of styrene and 30% of acrylonitrile, and then subjected to continuous bulk polymerization / demonomerization to obtain a rubber component of 10%. % Of a graft copolymer (B-11) was obtained.

Example 1 A twin-screw extruder having a heating device connected to two tanks having the specifications shown in Table 1 and a preheater, a demonomerizer, and a tandem barrel having a length of 1/3 from the tip of the demonomerizer. Styrene 7 using a continuous bulk polymerization apparatus consisting of a machine-type feeder
150 parts of a monomer mixture consisting of 0 parts, 30 parts of acrylonitrile and 0.15 part of n-octyl mercaptan.
/ H, the mixture was continuously supplied to the first polymerization tank to perform continuous bulk polymerization. The polymerization rate of the first polymerization tank was between 58 and 61%, and the operation of the polymer from the second polymerization tank was controlled between 90 and 91%. 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. 0.15 kg of a phenolic stabilizer, t-butylhydroxytoluene, was fed from a twin-screw extruder type feeder to the raised styrene / acrylonitrile copolymer.
/ H and 0.15 kg / h of tri (nonylphenyl) phosphite, which is a phosphorus-based stabilizer, together with the graft copolymer (B-1) produced in Reference Example 1 in a semi-molten state.
The mixture was fed at a rate of kg / hour, melt-kneaded with a styrene / acrylonitrile copolymer by a demonomerizer, discharged in a strand shape, and a styrene-based resin composition pellet was obtained by a cutter. The YI value of the obtained styrenic resin composition was as shown in Table 3. Table 4 shows the results obtained by molding injection molded pieces of the obtained styrene resin composition and measuring physical properties. As can be seen from Table 4, the styrenic resin composition produced by the method of the present invention was excellent in both color tone and physical properties.

Examples 2 to 11 The graft copolymers (B-2 to 11) produced in Reference Examples 2 to 11 were fed from a heated twin-screw extruder type feeder at a rate shown in Table 2 in a semi-molten state. Except for the above, styrene / acrylonitrile was subjected to continuous bulk polymerization / de-monomer to recover unreacted monomer under reduced pressure and melt-kneaded with styrene / acrylonitrile copolymer and graft copolymer using a de-monomer as in Example 1. Thereafter, the mixture was discharged in a strand shape to obtain a styrene-based resin composition pellet. Table 4 shows the YI value of the obtained styrenic resin composition and the measurement results of the physical properties of the test pieces obtained by injection molding the resin composition.

Example 12 Using the same continuous bulk polymerization apparatus as in Example 1, a monomer mixture consisting of 100 parts of styrene and 0.15 part of t-butyl mercaptan was charged into the first polymerization tank at an hourly speed of 150 kg / hour. It was fed continuously and polymerized continuously. The polymerization rate from the first polymerization tank is 67 to 70%, and the polymerization rate from the second polymerization tank is 9%.
Controlled and operated between 0-91%. After the polymerization reaction mixture was preheated in a single screw extruder type preheater as in Example 1,
Unreacted monomers were recovered by distillation under reduced pressure from the vent port by a twin-screw extruder type demonomer machine, and 1 /
The styrene polymer whose apparent polymerization rate rose to 99% or more at the point 3 was t-
After the graft copolymer (B-4) produced in Reference Example 2 was fed in a semi-molten state at a rate of 65 kg / hour together with 0.15 kg / hour of butylhydroxytoluene and melt-kneaded with a styrene polymer by a demonomerizer. A styrene-based resin composition pellet was obtained by discharging in a strand shape and using a cutter.
Table 4 shows the YI value of the obtained styrenic resin composition and the measurement results of the physical properties of the test pieces obtained by injection molding the resin composition.
It was shown to.

Example 13 A twin-screw extruder feeder having a tank having the specifications shown in Table 2 and a preheater, a demonomerizer, and a heating device connected in tandem to a 1/3 length barrel from the tip of the demonomerizer was used. Styrene 67 parts, acrylonitrile 33 parts, n-octyl mercaptan 0.1
A monomer mixture composed of 8 parts and 0.01 part of t-butyl peroxide was continuously supplied to the polymerization tank at a rate of 150 kg / hour to continuously polymerize. The polymerization rate of the polymerization tank is 74
Controlled and operated between ７６76%. After the polymerization reaction mixture is preheated by a single screw extruder type preheater, unreacted monomers are recovered by distillation under reduced pressure from a vent port by a twin screw extruder type demonomerizer, and 1 / 3k from the end of the demonomerizer. The styrene / acrylonitrile copolymer having an apparent polymerization rate of 99% or more was added to 0.15 kg / hr of a phenol-based stabilizer, t-butylhydroxytoluene, and tri (nonylphenyl), a phosphorus-based stabilizer. ) Phosphite 0.1
The graft copolymer (B-6) produced in Reference Example 6 was supplied in a semi-molten state at a rate of 65 kg / hour together with 5 kg / hour and melt-kneaded with a styrene / acrylonitrile copolymer by a demonomerizer, followed by pelletization. did. Table 4 shows the YI value of the obtained styrene-based resin composition pellets and the measurement results of physical properties of the test pieces obtained by injection-molding the resin composition.

Example 14 Using the same continuous bulk polymerization apparatus as in Example 11, 49 parts of styrene, 21 parts of acrylonitrile, 30 parts of N-phenylmaleimide, 10 parts of toluene, 0.18 parts of n-octylmercaptan and 0.18 parts of t- A monomer / solvent mixture consisting of 0.01 part of butyl peroxide was added at 150 kg /
The mixture was continuously supplied to the polymerization tank at the same speed as above, and was continuously polymerized.
The operation was performed while controlling the degree of polymerization at the polymerization tank between 74% and 76%. After the polymerization reaction mixture was preheated by a single screw extruder type preheater, the unreacted monomer and toluene were recovered by distillation under reduced pressure from a vent port by a twin screw extruder type demonomer machine, and one third of the monomer was removed from the tip of the demonomer machine. 99% apparent polymerization rate
Graft copolymer prepared in Reference Example 1 with 0.15 kg / hour of t-butylhydroxytoluene and 0.15 kg / hour of tri (nonylphenyl) phosphite added to the styrene / acrylonitrile / N-phenylmaleimide copolymer increased above. (B-1) in a semi-molten state at 65 kg /
The mixture was fed at the same speed as above, melt-kneaded with a styrene / acrylonitrile / N-phenylmaleimide copolymer by a demonomer, and then pelletized. Table 4 shows the YI value of the obtained imide-based resin pellets and the measurement results of the physical properties of the test pieces obtained by injection-molding the resin composition.

Comparative Example 1 Using a continuous bulk polymerization apparatus comprising two polymerization tanks having the specifications shown in Table 1, a preheater and a demonomerizer, styrene 70
Parts, 30 parts of acrylonitrile and 0.18 parts of n-octyl mercaptan were mixed at 150 kg /
It was continuously supplied to the first polymerization tank at the speed at the time, and was subjected to continuous polymerization. The conversion of the first polymerization tank is between 58 and 61%,
The operation was controlled while controlling the degree of polymerization from the second polymerization tank to 90 to 91%. The unreacted monomer was recovered by distillation under reduced pressure from the vent port of the polymerization reaction mixture by a twin-screw extruder-type demonomer machine, and the apparent polymerization rate was adjusted to 99% or more. The obtained styrene / acrylonitrile copolymer pellets and the graft copolymer (B-1) produced in Reference Example 1 were dry-blended at the ratios shown in Table 4, and then melt-kneaded / extrusion pelletized to obtain a styrene resin composition. A product pellet was obtained. Table 4 shows the YI value of the obtained styrene-based resin composition pellets and the characteristic measurement results of test pieces obtained by injection-molding the resin composition. The styrenic resin composition produced in this comparative example was clearly inferior in color tone (pellet YI) as compared with the examples.

Comparative Example 2 A monomer mixture consisting of 70 parts of styrene, 30 parts of acrylonitrile and 0.18 part of t-dodecyl mercaptan was polymerized by suspension polymerization, and the styrene obtained by dehydration and drying was obtained.
The acrylonitrile copolymer beads and the graft polymer (B-1) produced in Reference Example 1 were dry-blended at the ratios shown in Table 4, then melt-kneaded / extruded and pelletized to obtain styrene resin composition pellets. Table 4 shows the YI value of the obtained styrene-based resin composition pellets and the measurement results of physical properties of the test pieces obtained by injection-molding the resin composition.
The styrenic resin composition produced in this comparative example was clearly inferior in color tone (pellet I) as compared with the example.

Comparative Example 3 Using the same continuous bulk polymerization apparatus as in Example 1, 49 parts of styrene, 21 parts of acrylonitrile, 30 parts of N-phenylmaleimide, 10 parts of toluene, 0.18 parts of n-octylmercaptan and 0.18 parts of t- Butyl peroxide
A monomer / solvent mixture consisting of 01 parts was continuously supplied to the polymerization tank at a rate of 150 kg / hour to continuously polymerize. The operation was performed while controlling the degree of polymerization at the polymerization tank between 74% and 76%.
After the polymerization reaction mixture is preheated by a single screw extruder type preheater,
The unreacted monomer and toluene were recovered by distillation under reduced pressure from the vent port by a twin-screw extruder-type demonomer machine, and the apparent polymerization rate was adjusted to 99% or more. The obtained styrene / acrylonitrile / N-phenylmaleimide copolymer pellets and the graft copolymer (B-1) produced in Reference Example 1 were dry-blended at the ratio shown in Table 4 and then melt-kneaded / extruded. Pelletizing was performed to obtain imide resin composition pellets. Table 4 shows the TI value of the obtained styrene-based resin composition pellets and the measurement results of the physical properties of the test pieces obtained by injection-molding the resin composition. The color tone (pellet Y) of the imide resin composition produced in this comparative example was clearly
I) was inferior.

Comparative Example 4 The supply amount of the graft copolymer (B-1) of Example 1 was 5 k
A styrenic resin composition was obtained in the same manner as in Example 1 except that g / h was used. Table 4 shows the YI value of the obtained styrene resin composition pellets and the measurement results of the physical properties of the test pieces obtained by injection molding the styrene resin composition. The styrene resin composition produced in this comparative example was clearly inferior in Izod impact strength as compared with the example.

Comparative Example 5 The graft copolymer (B-B) was prepared in the same manner as in Example 1 except that the supply amount of the monomer mixture of styrene and acrylonitrile was 9 kg / h.
A styrene resin composition was obtained in the same manner as in Example 1 except that the supply amount in 1) was changed to 92 kg / hour. Table 4 shows the YI value of the obtained styrene-based resin composition pellets and the measurement results of physical properties of test pieces obtained by injection-molding the styrene resin composition. The styrene resin composition produced in this comparative example was clearly inferior in tensile strength as compared with the example.

[0040]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[0041]

According to the present invention, a resin containing no rubber component is produced by a continuous bulk polymerization method, and in the latter half of the demonomerization step, a graft copolymer containing a rubber component is added when the resin is in a molten state. It is characterized by mixing. for that reason,
As shown in Examples 1 to 14, a resin composition excellent in color tone and mechanical strength is obtained. Further, according to the production method of the present invention, it is possible to reduce the wastewater treatment, and further, the number of production steps is reduced, and the production cost can be reduced.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-8754 (JP, A) JP-A-57-49603 (JP, A) JP-A-62-158750 (JP, A) Koji Saeki, “ Polymer Production Process ”, First Edition, Industrial Research Institute, Ltd., September 25, 1971 (58) Fields investigated (Int. Cl. ⁷ , DB name) C08J 3/20-3/22 C08L 25/00- 25/18 C08L 51/04 C08L 55/02 C08F 6/26

Claims (7)

(57) [Claims] 1. An aromatic vinyl monomer 20 to 100% by weight, a vinyl cyanide monomer 0 to 60% by weight, (meth)
A copolymer (A) 10 obtained by continuously bulk polymerizing a monomer mixture comprising 0 to 80% by weight of an acrylate monomer and 0 to 60% by weight of another vinyl monomer copolymerizable therewith. To 95 parts by weight, 5 to 80 parts by weight of a rubbery polymer, 10 to 100% by weight of an aromatic vinyl monomer, 0 to 50% by weight of a vinyl cyanide monomer and (meth) acrylic acid 0 to 80% by weight of an ester monomer and 0 to 60 of other vinyl monomers copolymerizable therewith
In a process for producing an impact-resistant resin composition comprising 90 to 5 parts by weight of a graft copolymer (B) obtained by graft-polymerizing 95 to 20 parts by weight of a monomer mixture consisting of 95% by weight, Copolymer in state (A)
A method for producing an impact-resistant resin composition, wherein a graft copolymer (B) previously dehydrated and dried is continuously added and mixed. 2. The method for producing an impact-resistant resin composition according to claim 1, wherein the graft copolymer (B) is continuously added to the copolymer (A) having a residual monomer content of 10% by weight or less. 3. The graft copolymer (B) having a residual monomer content of 10% by weight or less during or after the demonomerization step of the continuous bulk polymerization of the copolymer (A) is grafted onto the graft copolymer (B). The method for producing an impact-resistant resin composition according to claim 1, wherein 4. The method for producing an impact-resistant resin composition according to claim 1, wherein the graft copolymer (B) is added in a semi-molten or molten state. 5. The method for producing an impact-resistant resin composition according to claim 1, wherein the rubbery polymer of the graft copolymer (B) is a diene rubber. 6. The copolymer (A) is a styrene - acrylonitrile copolymer, a graft copolymer (B) is styrene rubbery polymer - wherein a graft copolymer of acrylonitrile is graft copolymerized Item 4. A method for producing the impact-resistant resin composition according to item 1. 7. The demonomerization step in the continuous bulk polymerization of the copolymer (A) is a vented single-screw or twin-screw extruder, and the continuous addition apparatus for the graft copolymer (B) is a copolymer (B). The method for producing an impact-resistant resin composition according to claim 1, which is a single-screw or twin-screw extruder connected to the demonomer extruder (A).