JP2002012735A - Method for manufacturing thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition excellent in a color tone, mechanical properties such as impact resistance and balance of material properties such as appearance. SOLUTION: In a method for manufacturing continuously a thermoplastic resin composition by continuous bulk polymerization of a vinyl monomer to manufacture a vinyl copolymer (A) followed by adding a graft copolymer (B) into the vinyl copolymer (A) of a melt state to be melt mixed, when setting as V (m3) for real volume of the melt mixture part in an apparatus to be transferred while melt-mixing the vinyl copolymer (A) and the graft copolymer (B), T( deg.C) for a temperature and υ (kg/h) for a moving rate of the resin composition to be discharged finally, the following conditions are fulfilled simultaneously: 4.60×10-6<=V/υ<=11.50×10-6T>=230( deg.C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a vinyl (co) polymer (A) and a graft copolymer (B) which are effective for producing a thermoplastic resin composition having excellent color tone and impact resistance. And a method for mixing the same.

[0002]

2. Description of the Related Art As a method for producing a thermoplastic resin composition comprising a mixture of a vinyl copolymer (A) and a graft copolymer (B) typified by an ABS resin, a vinyl resin is generally used. A production method is known in which a vinyl copolymer (A) and a graft copolymer (B) polymerized from a monomer are separately polymerized into a polymer, and then heated and melted to mix them. I have. As a mixing method, for example, there is a method in which a vinyl copolymer (A) and a graft polymer (B) are mixed and then melted and mixed as in a melt mixing apparatus shown in FIG.

FIG. 3 is a schematic longitudinal sectional view showing an example of a fusion twin-screw mixing apparatus for mixing a vinyl copolymer (A) and a graft polymer (B). (A) is supplied quantitatively from the supply hopper (7), and the graft polymer (B) is supplied quantitatively from the supply hopper (8) to the mixing hopper (9). The resin particles mixed in the mixing hopper (9) are supplied to the melt mixing device (4) at a constant speed, and a predetermined temperature (230 ° C.) required for melt mixing.
In the heated system, the mixture is heated and melted, kneaded and transferred, and is discharged at a constant speed from the discharge port (6) after a lapse of a predetermined time.

According to this apparatus, at the time of heating and melting and mixing, both the vinyl copolymer (A) and the graft polymer (B) have a temperature,
Since the same heat history is received in terms of time, an excessive heat history is added to the graft copolymer (B), and there is a disadvantage that the color deteriorates.

On the other hand, as a method for lowering the heat history, a vinyl copolymer (A) is obtained by continuous bulk polymerization.
In a process for producing a thermoplastic resin composition, a method has been proposed in which a graft copolymer is continuously added to and mixed with a vinyl copolymer (A) in a molten state as polymerized to produce a thermoplastic resin composition. (For example, see JP-A-7-29220)
No. 5, JP-A-8-134298).

[0006]

However, it is difficult to balance color tone and impact resistance only by the methods disclosed in these publications, and to stably produce a resin composition having excellent overall quality. In order to do so, further improvements were longing for.

Therefore, the present invention solves the above-mentioned disadvantages of the prior art, and is a composition comprising a vinyl copolymer (A) and a graft polymer (B), and has a color tone, impact resistance and the like. An object of the present invention is to provide a method for stably producing a thermoplastic resin composition having excellent mechanical properties.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, a graft copolymer was added to a vinyl copolymer (A) which had been continuously mass-polymerized and remained in a molten state. The present inventors have found that it is effective to specify conditions and the like when adding (B) and melt-mixing, and have accomplished the present invention.

That is, according to the present invention, a copolymer (A) is produced by continuous bulk polymerization of a vinyl monomer mixture (a), and then a graft copolymer (A) is added to the copolymer (A) in a molten state. B) is added and melt-mixed to continuously produce a thermoplastic resin composition. In the method, the copolymer (A) and the graft copolymer (B) are melt-mixed and transported while being melt-mixed. When the actual volume in the apparatus is V (m ³ ), the temperature is T (° C.), and the moving speed of the finally discharged resin composition is υ (kg / h), the following conditions are satisfied at the same time. , A method for producing a thermoplastic resin composition. 4.60 × 10 ⁻⁶ ≦ V / υ ≦ 11.50 × 10 ⁻⁶ (m ³ · h / kg) T ≧ 230 (° C.)

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic resin composition produced by the method of the present invention comprises a vinyl (co) polymer (A) and a graft copolymer (B).

The vinyl-based (co) polymer (A) is obtained by continuous bulk polymerization of one or more vinyl-based monomers (a). Styrene-acrylonitrile copolymer, styrene-N-phenylmaleimide copolymer, styrene-acrylonitrile-methyl methacrylate copolymer, styrene-methyl methacrylate copolymer, among which styrene-acrylonitrile copolymer is particularly preferred It is preferably used.

Further, as the graft copolymer (B),
A copolymer obtained by graft-polymerizing one or more vinyl monomers (c) in the presence of the rubbery polymer (b) is preferable, and a preferable specific example is a styrene graft copolymer of polybutadiene. Copolymer, poly (butadiene-styrene) styrene graft copolymer, polybutadiene styrene-acrylonitrile graft copolymer, poly (butadiene-styrene) styrene-acrylonitrile graft copolymer, poly (butadiene-acrylonitrile) styrene-acrylonitrile Graft copolymer,
Examples thereof include styrene-acrylonitrile-methyl methacrylate graft copolymer of polybutadiene and styrene-acrylonitrile graft copolymer of poly (ethylene-propylene).

The vinyl monomer (a) and the vinyl monomer (c) include aromatic vinyl monomers, vinyl cyanide monomers, and unsaturated carboxylic acid alkyl ester monomers. And other vinyl monomers copolymerizable therewith, and a monomer mixture containing an aromatic vinyl monomer as an essential component is particularly preferably used.

The aromatic vinyl monomer is an aromatic compound having a polymerizable double bond. Specific examples thereof include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, propylstyrene, and butylstyrene. And cyclohexylstyrene. These aromatic vinyl monomers are used singly or as a mixture of two or more. Among these aromatic vinyl monomers,
Styrene and α-methylstyrene are particularly preferably used.

The vinyl cyanide monomer is a compound having a polymerizable double bond and a cyano group. Specific examples thereof include acrylonitrile and methacrylonitrile. These vinyl cyanide monomers are
Used in one kind or in a mixture of two or more kinds. Of these vinyl cyanide monomers, acrylonitrile is particularly preferably used.

The unsaturated carboxylic acid alkyl ester monomer is an alkyl ester compound of a vinyl carboxylic acid having a polymerizable double bond and a carboxyl group, and is generally an α, β-unsaturated carboxylic acid. Alkyl esters are 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,
Examples include ethyl methacrylate, propyl methacrylate, butyl methacrylate, glycidyl methacrylate, hydroxyethyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate and the like. These unsaturated carboxylic acid alkyl ester monomers are used alone or in a mixture of two or more.
Of these unsaturated carboxylic acid alkyl ester monomers, (meth) acrylic acid alkyl esters are preferred,
Specifically, methyl methacrylate is particularly preferably used.

The other monomers that can be used further include, for example, N-phenylmaleimide, N-cyclohexylmaleimide, methyl-substituted N-phenylmaleimide, maleic anhydride, acrylic acid, methacrylic acid and the like. Among them, N-phenylmaleimide is particularly preferably used.

The rubbery polymer (b) used in the graft copolymer (B) is a diene rubber, an acrylic rubber, an ethylene rubber or the like. 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.

The reduced viscosity of the vinyl (co) polymer (A) (hereinafter abbreviated as vinyl copolymer (A)) obtained from the vinyl monomer (a) is not limited. Preferably, it is 0.10 to 0.70 dl / g, more preferably 0.15 to 0.60 dl / g.

When a resin composition having transparency is produced as the resin composition of the present invention, the haze value, which is an index of transparency, is 0 to 15%.
Is preferably, and more preferably 0 to 13%. In this case, the method for measuring the haze value is as described in Examples.

In the case of producing a resin composition having transparency and excellent impact resistance, a styrene-acrylonitrile-methyl methacrylate copolymer is particularly preferred as the vinyl copolymer (A). As the graft copolymer (B), a styrene-acrylonitrile-methyl methacrylate graft copolymer of polybutadiene is particularly preferred.

The proportion of each monomer used in the production of the vinyl copolymer (A) is generally selected from aromatic vinyl resins in view of the mechanical strength, color tone and moldability of the obtained resin composition. 45 to 85% by weight of a monomer (a1), 0 to 30% by weight of an alkyl carboxylate monomer (a2), 15 to 50% by weight of a vinyl cyanide monomer (a3)
And other monomer (a4) 0 copolymerizable therewith
To 35% by weight, more preferably 60 to 85% by weight of an aromatic vinyl monomer, 0 to 20% by weight of an unsaturated carboxylic acid alkyl ester monomer and 15 to 15% by weight of a vinyl cyanide monomer. To 40% by weight and 0 to 20% by weight of other vinyl monomers copolymerizable therewith.

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

Specifically, when used in a transparent resin composition, the proportion of each monomer of the vinyl copolymer (A) is from 5 to 70% by weight of the aromatic vinyl monomer (a1). %,
Unsaturated carboxylic acid alkyl ester monomer (a2) 3
0 to 95% by weight, vinyl cyanide monomer (a3) 0
It is preferably 35% by weight and 0 to 50% by weight of another monomer (a4) copolymerizable therewith, more preferably 5 to 55% by weight of an aromatic vinyl monomer (a1), and unsaturated monomer. Carboxylic acid alkyl ester monomer (a
2) 45 to 95% by weight of a vinyl cyanide monomer (a
3) 0 to 25% by weight and 0 to 40% by weight of other monomer (a4) copolymerizable therewith.

The vinyl copolymer (A) comprises an aromatic vinyl monomer, a vinyl cyanide monomer, an unsaturated carboxylic acid alkyl ester monomer, and other vinyl monomers. It is produced by continuous bulk polymerization of a vinyl monomer (a), but the polymerization method is not limited,
Any continuous bulk polymerization method can be employed, for example,
It is manufactured by a method of demonomerization (devolatilization) after polymerization in a polymerization tank.

In the continuous bulk polymerization, thermal polymerization without using an initiator, initiator polymerization using an initiator,
In addition, thermal polymerization and initiator polymerization may be used in combination. 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, 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. Above all, 1,1'-azobiscyclohexane-1
-Carbonitrile is particularly preferably used.

For the purpose of controlling the degree of polymerization of the vinyl copolymer (A), it is also 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.

In the present invention, the vinyl copolymer (A) is produced by a continuous bulk polymerization method, but may be produced by a method in which polymerization is carried out using a small amount (for example, 20% by weight or less) of a solvent.

The graft copolymer (B) which is the other component used in the present invention is a rubbery polymer (b)
An aromatic vinyl monomer, a vinyl cyanide monomer,
It is preferably a copolymer obtained by subjecting a monomer mixture of an unsaturated carboxylic acid alkyl ester-based monomer and another vinyl-based monomer copolymerizable therewith to an emulsion graft polymerization reaction. What was obtained as a mixture of the partially grafted copolymer and the non-grafted copolymer may be used.

The reduced viscosity of the graft copolymer (B) is not limited, but preferably 0.10 to 0.60 dl / g, more preferably 0.15 to 0.50 dl / g. The graft ratio of the graft copolymer (B) is not limited, but is preferably 5 to 150%, more preferably 10 to 150%.
〜100% are used.

The proportion of the rubbery polymer (b) in the graft copolymer (B) is generally from 10 to 80 parts by weight from the viewpoint of mechanical strength, color tone and moldability of the obtained resin composition. Preferably, it is more preferably 20 to 70 parts by weight.

In the graft copolymer (B), the proportion of each monomer other than the rubbery polymer (b) is generally
50 to 85% by weight of an aromatic vinyl monomer (c1) and an unsaturated carboxylic acid alkyl ester monomer (c2) 0 to 3
0% by weight, vinyl cyanide monomer (c3) 15 to 50
% By weight and other monomers copolymerizable therewith (c
4) 0 to 35% by weight is preferred, more preferably 50 to 80% by weight of an aromatic vinyl monomer (c1), 0 to 20% by weight of an unsaturated carboxylic acid alkyl ester monomer (c2), and cyanation 20 to 50% by weight of vinyl monomer (c
3).

When producing a resin composition having excellent transparency and impact resistance, the proportion of the rubbery polymer (b) in the graft copolymer (B) is determined by the ratio of the obtained resin composition. The amount is preferably 5 to 80 parts by weight, more preferably 20 to 70 parts by weight from the viewpoint of mechanical strength, color tone and moldability.
The proportion of each monomer other than the rubbery polymer (b) is 5 to 70% by weight of the aromatic vinyl monomer (c1) and 30% by weight of the unsaturated carboxylic acid alkyl ester monomer (c2).
To 95% by weight, vinyl cyanide monomer (c3) 0 to 3
5% by weight and other monomers (c4) copolymerizable therewith are preferably 0 to 50% by weight, more preferably
5 to 55% by weight of an aromatic vinyl monomer (c1), 50 to 9 of an unsaturated carboxylic acid alkyl ester monomer (c2)
0% by weight, and a vinyl cyanide monomer (c3) 0 to 2
5% by weight.

The method for producing the graft copolymer (B) is not particularly limited, but is preferably produced by emulsion polymerization or bulk polymerization, particularly preferably by emulsion polymerization. Emulsion polymerization may be performed by emulsion graft polymerization of a vinyl monomer in the presence of a rubbery polymer latex (rubbery polymer (b)). There is no particular limitation on the emulsifier used in this emulsion graft polymerization, and various surfactants can be used, but carboxylate type, sulfate type,
Anionic surfactants such as sulfonic acid salts are particularly preferably used.

Specific examples of such emulsifiers include caprylate, caprate, laurate, mystyrate, palmitate, stearate, oleate, and the like.
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 chain transfer agent that can be used in the emulsion graft polymerization include the same initiators and chain transfer agents (described later) used in the production of the vinyl copolymer (A). The initiators are also used in redox systems.

The latex of the graft copolymer (B) produced by the emulsion graft polymerization is then added with a coagulant and coagulated 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.

The thermoplastic resin composition produced by the present invention comprises:
The mixed composition of the vinyl copolymer (A) and the graft copolymer (B) is 10 to 95 parts by weight of the vinyl copolymer (A) and 90 to 5 parts by weight of the graft copolymer (B). Is preferred.

In order to continuously produce this thermoplastic resin composition, the method of the present invention comprises the steps of subjecting the vinyl monomer mixture (a) to continuous bulk polymerization to produce a vinyl copolymer (A). Graft copolymer (B) to copolymer (A) in molten state
And melt-mixing.

This manufacturing method is carried out, for example, by a manufacturing apparatus shown in FIGS.

FIG. 1 is a schematic longitudinal sectional view showing an embodiment of an apparatus for carrying out the method of the present invention. The vinyl monomer (a) is successively bulk-polymerized to form a vinyl copolymer. A reaction tank (1) for producing (A), a preheater (2) for keeping the vinyl copolymer (A) obtained by polymerization in a molten state at a predetermined temperature, and a vent for demonomerization A twin-screw extruder (3) having a mouth and a twin-screw extruder in which a twin-screw kneading extruder (4) is connected are provided, and further, between the de-monomer and the twin-screw kneading extruder. And a twin-screw extruder type feeder (5) for adding the graft copolymer (B). FIG. 2 is a schematic cross-sectional view of the device in the twin-screw kneading extruder (4), in which a screw (4
2, 42 ').

As the reaction tank (1) for continuous bulk polymerization,
A reaction vessel of a complete mixing type having a helical ribbon blade (11) as shown in FIG. 1 is preferable, but other stirring blades such as a paddle blade, a turbine blade, a propeller blade, a bulmar blade, a multistage blade, and an anchor are also available. A mixed-type polymerization tank having blades, Max-blend blades, double helical blades, or the like, or various tower-type reactors can be used. Furthermore, a multi-tube reactor, a kneader-type reactor, a twin-screw extruder, or the like can also be used as a polymerization reactor (Assessment 10 of polymer production process “Assessment of impact-resistant polystyrene”: Society of Polymer Science, 1989) Issued on January 26, 2008). One of these polymerization tanks (reactor) (tank)
In addition to the use of a reactor, two or more reactors (tanks) or a combination of two or more reactors may be used, if necessary.

The reaction product obtained by polymerization in the reaction tank (1) or the reactor usually contains monomers and other volatile components in addition to the vinyl copolymer (A). Therefore, it is necessary to remove those volatile components. This volatile component removal is preferably carried out by a method of removing volatile components from the vent port under heating at normal pressure or reduced pressure with a single-screw or twin-screw extruder having a vent port. Other methods include removing a volatile component with an evaporator having a plate-fin type heater such as a centrifugal type built in a drum before supplying it to an extruder, removing a volatile component with a thin film evaporator such as a centrifugal type, A method of removing residual components by using a tubular heat exchanger, preheating, foaming and flashing into a vacuum chamber to remove volatile components can also be used.

In FIG. 1, a reaction product continuously supplied from a reaction tank (1) is supplied to a pre-heater (2) for 150 to 2 hours.
It is maintained in a molten state at about 80 ° C., and then supplied to a twin-screw extruder type demonomer machine (3). At about 150 to 280 ° C. under normal pressure or reduced pressure, a monomer or the like is passed through a vent port (31). Volatile components are removed from the system. The removal of the volatile components is performed until the amount of the unreacted monomer becomes a predetermined amount, for example, 10% by weight or less, more preferably 5% by weight or less.

In FIG. 1, after the demonomerizer (3), an addition port from the feeder (5) is opened, and the graft copolymer (B) at a predetermined temperature (about 100 to 220 ° C.) is used. Is added within. As the feeder (5), various feeders such as a twin-screw extruder type feeder shown in FIG. 1, for example, a belt type feeder and a screw type feeder can be used, and the resin is quantitatively and continuously added. Further, a heating device is provided in the feeder (5), and the graft copolymer (B) to be added is provided.
Is preferably heated to a predetermined temperature in a semi-molten or molten state in order to improve the mixing state. For example, a screw, a cylinder, and a screw drive unit are preferably used, and the cylinder preferably has a device structure having a heating / cooling function. Further, as this feeder, a single-screw or twin-screw extruder type feeder having a heating device can be used.

The supply port of the graft copolymer (B) is
It can be provided in the middle of the demonomerized part (3), but even in this case, the supply port should be provided at the stage where the amount of unreacted monomer is reduced to 10% by weight or less, more preferably 5% by weight or less. However, it is preferable to prevent thermal deterioration of the rubber component during the subsequent operation of removing the unreacted monomer, and to further improve the color tone and impact resistance of the obtained resin composition.

In FIG. 1, a twin-screw kneading extruder (4)
And the vinyl copolymer (A) and the graft copolymer (B)
Is transferred while being melted and mixed at a temperature of 230 ° C. or more, and the shape of the inner wall (43) in the barrel is as shown in FIG.
The two circles are partially overlapped and connected. Screws rotating around the center of each circle (4
2, 42 ') are disposed inside, and the two screws (42, 42') are rotating at the same speed with a predetermined phase difference. While being transferred to the discharge port (6).

In the present invention, the actual volume V in the apparatus, the moving speed υ, and the temperature of the melt-mixing portion (41) in which the vinyl copolymer (A) and the graft copolymer (B) are transferred while being melt-mixed. T is a predetermined condition (the following conditions and)
It is important that Here, the melt mixing portion (4
1) is a portion from the position where the addition port from the twin-screw extruder type feeder (5) is open (the center) to the discharge hole (6).

The actual volume (V) in the apparatus of the melt mixing section (41)
m ³ ) is a value obtained by subtracting the screw volume existing in the melt-mixing portion (4) from the volume in the barrel in the melt-mixing portion (4). In addition, the moving speed (υ kg /
h) is the discharge speed of the resin composition discharged from the melt mixing portion (4) to the outside of the system. Furthermore, the temperature (T
° C) is the set temperature inside the melt mixing section (4).

4.60 × 10 ⁻⁶ ≦ V / υ ≦ 11.50 × 10 ⁻⁶ (m ³ · h / kg) ··· T ≧ 230 (° C) ··· More preferably, 6.15 × 10 ⁻⁶ ≦ V / υ ≦ 9.40 × 10 ⁻⁶ (m ³ · h / kg).

When the value of V / υ is less than the lower limit of the above condition, the graft copolymer (B) and the vinyl copolymer (A)
And the impact resistance is deteriorated. Conversely, when the value exceeds the upper limit of the above conditions, a problem occurs that the color tone of the obtained thermoplastic resin is deteriorated.

The temperature (T ° C.) of the melt-mixing portion (4)
Requires 230 ° C. or higher, preferably 235 to
250 ° C is good. The resin temperature of the graft copolymer (B) before being added to the melt mixing portion (4) is 100 to 22.
0 ° C. is preferred, especially 220 ° C. in the molten or semi-molten state.
C. or less is preferred. The temperature of the vinyl copolymer (A) before reaching the melt mixing portion (4) is not particularly limited, but is preferably about 150 ° C to 280 ° C.

[0055]

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples, but these examples do not limit the present invention at all. Unless otherwise specified, “%” indicates% by weight and “parts” indicates “parts by weight”. The method for analyzing the resin properties of the rubber-reinforced styrene resin composition is described below. With respect to general resin properties such as impact resistance, tensile strength, and color tone, test pieces were manufactured by injection molding and measured according to the following test methods.

(1) Reduced viscosity Methyl ethyl ketone (hereinafter referred to as MEK)
It is a value measured at 0 ° C. and is determined by the following equation. Specific viscosity = (Regulated range falling time of vinyl copolymer MEK solution / Regulated range falling time of MEK solvent) -1 Reduced viscosity (dl / g) = Specific viscosity / Vinyl polymer MEK
Solution concentration (2) Graft ratio The non-graft component of the graft copolymer is dissolved in acetone, the graft component (c) and the rubbery polymer (b) are isolated as insolubles, weighed, and weighed according to the following formula. Ask. Graft ratio (%) = [(weight of insoluble matter−weight of rubbery polymer (b)) / weight of rubbery polymer (b)] × 100 (3) Copolymer (A) and rubbery polymer (b) A small amount of 1-bromonaphthalene was dropped on a sample to be measured, and the refractive index was measured using an Abbe refractometer under the following conditions. Light source: sodium lamp D line Measurement temperature: 20 ° C. (4) Refractive index of graft component (c) Refractive index of insoluble matter isolated by the above method (2) using the same refractive index measurement method as in the above (3) Was measured.

(5) Color tone (YI value) Measured according to JIS K7103. (6) Transparency (Haze value) Toshiba Corporation pellets of the resin composition dried in an 80 ° C. hot air dryer for 3 hours were set at a cylinder temperature of 250 ° C.
The haze value [%] of a square plate molded product (thickness: 3 mm) which was filled into an IS50A molding machine and molded immediately was measured by the Toyo Seiki Co., Ltd.
It measured using the direct reading haze meter. (7) Izod impact strength Measured according to ASTM D256 (23 ° C., with V notch). (8) Tensile strength Measured according to ASTM 638. (9) Actual volume of the melt mixing section in the apparatus, V (m ³ ) In the case of the apparatus shown in FIG. 1, the melt mixing section in the melt mixing apparatus is from the center of the addition port from the twin screw extruder type feeder (5). This is the portion up to the discharge hole (6). FIG.
In the case of the device shown in (1), the entire melt mixing device (4) corresponds to the melt mixing portion. The actual volume [V] in the apparatus is obtained by calculating the volume in the barrel in these melt-mixing portions and subtracting the screw volume in the melt-mixing portion from this volume.
(M ³ )]. (10) The moving speed of the finally discharged resin composition, Δ
(Kg / h) The polymer discharged within a certain period of time was dried and the weight was measured, and the polymer movement speed υ (kg / h) was determined from the weight / time.

Reference Example 1 (Graft copolymer (B-
Production method of 1)) Polybutadiene latex (rubber particle type 0.3 μm, gel content 85%) 50 parts (solid content conversion), pure water 200 parts,
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. Parts, 15 parts of acrylonitrile 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 obtained after the completion of the polymerization was used for 1.
After coagulation with 5% sulfuric acid, the mixture was neutralized with sodium hydroxide, washed, centrifuged, and dried to prepare a powdery graft copolymer (B-1).

Reference Examples 2 to 6 (Graft copolymer (B
-2 to B-6)) In the same manner as in Reference Example 1, a mixture of styrene and other vinyl monomers was added in the presence of the rubbery polymer (b) shown in Tables 1 and 2. Polymerization was performed to produce graft copolymers (B-2 to B-6) 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.

[0061]

[Table 1]

[0062]

[Table 2]

Example 1 As shown in FIG. 1, a complete mixing type reaction tank having helical ribbon blades (1), a preheater (2), a twin-screw extruder type demonomer machine (3), and A twin-screw extruder (4) is arranged in order, and a twin-screw extruder type having a heating device in a barrel portion at a position of about 0.7 m upstream from a discharge hole at the tip of the twin-screw kneading extruder (4). Continuous bulk polymerization, demonomerization with open feeder (5),
And a device for performing melt mixing. This reaction tank (1)
70 parts of styrene, 30 parts of acrylonitrile and n
-A monomer mixture consisting of 0.15 parts of octyl mercaptan was continuously supplied at 135 kg / h to carry out continuous bulk polymerization. The polymerization rate of the reaction product discharged from the reaction tank is 75 to
76%. The obtained polymerization reaction product is collected by evaporating and recovering volatile components such as unreacted monomers from the vent port under reduced pressure by a twin-screw extruder-type demonomer machine (3), and increases the apparent polymerization rate to 99% or more. Thus, a styrene / acrylonitrile copolymer was obtained.

The styrene / acrylonitrile copolymer was fed to a twin-screw extruder type feeder (5) using 0.15 t-butylhydroxytoluene as a phenolic stabilizer.
Reference Example 1 together with 0.15 kg / h and 0.15 kg / h of tri (nonylphenyl) phosphite which is a phosphorus-based stabilizer
66 kg / h of the graft copolymer (B-1) produced in
And melt-kneaded at a resin temperature of 240 ° C. for a predetermined time, continuously discharged in a strand shape, and obtained a styrene resin composition pellet by a cutter. Table 3 shows the values of V and Δ during the melt mixing. In addition, as shown in Table 3, the properties of the obtained styrene-based resin composition were excellent in color tone, impact strength, and tensile strength.

Examples 2 to 8 The compositions of the vinyl monomer mixture supplied to the bulk polymerization, the type of the graft copolymer added, the mixing composition, and the mixing conditions are shown in Tables 3 and 4. Continuous bulk polymerization, demonomerization, and melt mixing were performed under the same apparatus and conditions as in Example 1 except that the conditions were changed to. In Example 5, the supply amount of the monomer mixture to the continuous bulk polymerization was 150 kg / h. As shown in Tables 3 and 4, the monomer supply amount was excellent in color tone, impact strength, and tensile strength, as shown in Tables 3 and 4 for the characteristics of the obtained styrene resin composition.

Comparative Example 1 A complete mixing type reaction tank having a helical ribbon blade (first polymerization tank) and a plug flow type reaction tank having a multistage perforated plate and a scraping blade (second polymerization tank)
, 70 parts of styrene, 30 parts of acrylonitrile and n
-A monomer mixture consisting of 0.15 parts of octyl mercaptan was continuously supplied at 135 kg / h to carry out continuous bulk polymerization. The polymerization rate in the first polymerization tank is 58 to 61%,
The polymerization rate at the time of exit from the polymerization tank was 90 to 91%. The unreacted monomer is recovered by distillation under reduced pressure from the vent port with a twin-screw extruder-type demonomer removing machine, and the apparent polymerization rate is discharged to a strand shape with an apparent polymerization rate of 99% or more. It has become.

The obtained styrene / acrylonitrile copolymer was supplied at a rate of 63.3 kg / h, and the styrene / acrylonitrile copolymer and the graft copolymer (B-1) produced in Reference Example 1 were mixed with 67/33. After being dry-blended by the mixing hopper of FIG. 3 in the ratio shown in FIG. 3, it was melt-mixed under the melt-mixing conditions shown in Table 3, extruded and pelletized to obtain styrene resin composition pellets. Table 3 shows the properties of the obtained styrenic resin composition.

[Comparative Example 2] The opening position of the twin-screw extruder type feeder (5) was changed from the tip of the discharge hole side of the twin-screw kneading extruder (4) to a barrel portion at a position of about 1.4 m upstream from the discharge hole. Except for this, in the same manner as in Example 1, continuous bulk polymerization, demonomerization, and melt mixing were performed using an apparatus having the structure shown in FIG. Table 3 shows the properties of the obtained styrenic resin composition.

[Comparative Example 3] The opening position of the twin-screw extruder type feeder (5) was changed from the tip of the discharge hole side of the twin-screw kneading extruder (4) to a barrel portion at a position of about 0.35 m upstream of the river. Except for this, in the same manner as in Example 1, continuous bulk polymerization, demonomerization, and melt mixing were performed using an apparatus having the structure shown in FIG. Table 3 shows the properties of the obtained styrenic resin composition.

[Comparative Example 4] The composition of the vinyl monomer mixture supplied to the bulk polymerization, the type of the graft copolymer added, the mixing composition, and the mixing conditions were changed as shown in Table 4, and Continuous bulk polymerization, demonomerization, and melt mixing were performed under the same apparatus and conditions as in Comparative Example 1 except that the supply amount of the system copolymer was changed to 70 kg / h. Table 4 shows the properties of the obtained styrene resin composition.

Comparative Example 5 The composition of the vinyl monomer mixture supplied to the bulk polymerization, the type of the graft copolymer added, the mixed composition, and the mixing conditions were changed as shown in Table 4. Continuous bulk polymerization, demonomerization, and melt mixing were performed under the same apparatus and conditions as in Comparative Example 2. Table 4 shows the properties of the obtained styrene resin composition.

Comparative Example 6 The composition of the vinyl monomer mixture supplied to the bulk polymerization, the type of the graft copolymer added, the mixing composition, and the mixing conditions were changed as shown in Table 4. Continuous bulk polymerization, demonomerization, and melt mixing were performed under the same apparatus and conditions as in Comparative Example 3. Table 4 shows the properties of the obtained styrene resin composition.

[0073]

[Table 3]

[0074]

[Table 4] As can be seen from Tables 3 and 4, the styrenic resin composition produced by the method of the present invention was excellent in color tone, impact resistance and tensile strength, but in the case of the comparative example carried out under conditions outside the present invention. Failed to satisfy both of these characteristics.

[0075]

According to the method of the present invention, the composition comprises a vinyl copolymer (A) and a graft polymer (B), and has a color tone, mechanical properties such as impact resistance, and appearance. Both excellent thermoplastic resin compositions can be stably produced.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing an embodiment of an apparatus for carrying out the method of the present invention.

FIG. 2 is a schematic cross-sectional view of the twin-screw kneading extruder of the apparatus shown in FIG.

FIG. 3 is a schematic longitudinal sectional view of an example of a conventional molten twin-screw mixing apparatus.

[Explanation of symbols]

 1: Reaction tank 11: Helical ribbon blade 2: Preheater 3: Demonomerizer 31: Vent port 4: Twin screw kneading extruder 41: Melt mixing part 42, 42 ': Screw 43: Inner wall in barrel 44: Inside of equipment Volume space 5: Feeder 6: Discharge port 7, 8: Supply hopper 9: Mixing hopper

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 4F070 AA08 AA18 AA30 AA32 AA34 AB08 AB09 AB11 FA03 FB06 FC04 FC05 4J002 BC03W BC06W BC07W BH01W BN14X BN15X BN16X

Claims (8)

[Claims] 1. A vinyl-based (co) polymer (A) is produced by continuous bulk polymerization of a vinyl-based monomer (a), and subsequently grafted to a vinyl-based (co) polymer (A) in a molten state. In a method of continuously producing a thermoplastic resin composition by adding a copolymer (B) and melt-mixing, a vinyl-based (co) polymer (A) and a graft copolymer (B) are melt-mixed. When the actual volume in the apparatus of the molten mixing portion transferred while the apparatus is V (m ³ ), the temperature is T (° C.), and the moving speed of the finally discharged resin composition is υ (kg / h) A method for producing a thermoplastic resin composition, which satisfies the following conditions and at the same time. 4.60 × 10 ⁻⁶ ≦ V / υ ≦ 11.50 × 10 ⁻⁶ (m ³ · h / kg) T ≧ 230 (° C.) 2. The method for producing a thermoplastic resin composition according to claim 1, wherein the temperature of the graft copolymer (B) when supplied to the melt mixing device is 100 to 220 ° C. 3. The method for producing a thermoplastic resin composition according to claim 1, wherein the graft copolymer (B) when supplied to the melt mixing device is in a semi-molten or molten state. 4. The graft copolymer (B) is a copolymer obtained by graft-polymerizing a vinyl monomer (c) in the presence of a rubbery polymer (b), and is obtained by melt mixing. The thermoplastic resin composition is a vinyl (co) polymer (A) 10 to 95.
Parts by weight and a graft copolymer (B) having a composition of 90 to 5 parts by weight, and a vinyl (co) polymer in a molten state obtained by continuous bulk polymerization of a vinyl monomer (a) ( The method for producing a thermoplastic resin composition according to any one of claims 1 to 3, wherein the graft copolymer (B) is added to A), and the mixture is melt-mixed. 5. The vinyl (co) polymer (A) when the graft copolymer (B) is added has an unreacted monomer content of 10%.
The method for producing a thermoplastic resin composition according to any one of claims 1 to 4, which is not more than weight%. 6. A vinyl (co) polymer (A) in which the vinyl monomer (a) is subjected to continuous bulk polymerization followed by demonomerization.
In the production process, the vinyl (co) polymer (A) during or after the demonomerization step,
2. A graft copolymer (B) is added and melt-mixed.
A method for producing a thermoplastic resin composition according to any one of claims 1 to 5. 7. A vinyl (co) polymer (A) comprising 45 to 85% by weight of an aromatic vinyl monomer (a1) and 0 to 30% by weight of an unsaturated carboxylic acid alkyl ester monomer (a2). %, Vinyl cyanide monomer (a3) 15 to 50% by weight
And other monomers (a4) 0 to 3 copolymerizable therewith.
5% by weight of a vinyl-based monomer mixture (a ') is a continuous bulk polymerization of a vinyl-based copolymer (A'), and the graft copolymer (B) is a rubber-based polymer (A). In the presence of b), 45 to 85% by weight of an aromatic vinyl monomer (c1) and an unsaturated carboxylic acid alkyl ester monomer (c
2) 0 to 30% by weight, vinyl cyanide monomer (c3)
A graft copolymer (B ′) obtained by graft-polymerizing a vinyl monomer mixture (c ′) composed of 15 to 50% by weight and 0 to 35% by weight of another monomer (c4) copolymerizable therewith; The method for producing a thermoplastic resin composition according to any one of claims 4 to 6, wherein 8. The vinyl (co) polymer (A) comprises 5 to 70% by weight of an aromatic vinyl monomer (a1) and 30 to 95% by weight of an unsaturated carboxylic acid alkyl ester monomer (a2). %, 0 to 35% by weight of a vinyl cyanide monomer (a3) and 0 to 50 of another monomer (a4) copolymerizable therewith.
% Of a vinyl monomer mixture (a ″) by continuous bulk polymerization of a vinyl copolymer (A ″), and the graft copolymer (B) is a rubbery polymer (b). ) In the presence of 5 to 70% by weight of the aromatic vinyl monomer (c1) and the unsaturated carboxylic acid alkyl ester monomer (c
2) 30 to 95% by weight of a vinyl cyanide monomer (c
3) A graft copolymer obtained by graft-polymerizing a vinyl monomer mixture (c ″) comprising 0 to 35% by weight and 0 to 50% by weight of another monomer (c4) copolymerizable therewith ( B ''). The method for producing a thermoplastic resin composition according to any one of claims 4 to 6.