JP2002212369A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic resin composition having equilibrated and excellent transparency, chemical resistance and color tone stability. SOLUTION: This thermoplastic resin composition is obtained by dispersing a specific rubber-containing graft copolymer in a specific vinylic copolymer prepared by carrying out continuous bulk polymerization or continuous solution polymerization and is characterized in that the ratio of triad sequence of acrylonitrile monomer units present in the acetone-soluble component of the thermoplastic resin composition is <=10 wt.% based on the acetone-soluble component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rubber-containing styrene-based thermoplastic resin composition having transparency, and more particularly, to a rubber having excellent transparency, chemical resistance and color tone stability. The present invention relates to a styrene-based thermoplastic resin composition.

[0002]

2. Description of the Related Art A rubbery polymer such as a diene rubber contains a graft copolymer obtained by copolymerizing an aromatic vinyl compound such as styrene and α-methylstyrene and a vinyl cyanide compound such as acrylonitrile and methacrylonitrile. Transparent ABS resin has excellent mechanical strength balance such as transparency, impact resistance and rigidity, moldability and cost performance, so it is widely used in application fields such as home appliances, communication related equipment and general goods. Have been.

[0003] However, such transparent ABS resins are used in limited applications because of their low resistance to chemicals such as organic solvents and solvents such as detergents.

As a means for improving the chemical resistance of a general ABS resin having no transparency, it is generally known to increase the content ratio of a vinyl cyanide compound, and a so-called high nitrile-containing thermoplastic resin composition is used. Various proposals have been made.

For example, in terms of improving chemical resistance,
Resin compositions having a specified graft ratio of the graft copolymer (JP-A-4-258609, JP-A-5-7842)
No. 8) and a high nitrile-containing thermoplastic resin composition containing a methacrylic acid ester as an essential component as a matrix component (Japanese Patent Application Laid-Open No. 4-126756).

However, in the above-mentioned conventional high-nitrile-containing thermoplastic resin composition, the reaction rates of the aromatic vinyl compound and the vinyl cyanide compound are different from each other.
It was difficult to obtain a polymer having a uniform composition. Therefore, a thermoplastic resin composition containing a copolymer of an aromatic vinyl compound and a vinyl cyanide compound tends to be colored yellow at the time of molding processing, and the quality has been deteriorated due to discoloration.

As described above, the technique of improving chemical resistance by increasing nitrile tends to cause problems such as discoloration and decrease in transparency caused by increasing nitrile.
Conventionally, it has been considered that application to S is a fatal defect for transparent resin products.

Therefore, a high nitrile-containing thermoplastic resin composition having excellent balance of transparency, chemical resistance and color tone stability has not been obtained.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been achieved as a result of studying to solve the above-mentioned problems in the prior art, and is excellent in transparency, chemical resistance and color tone stability. And a rubber-containing styrene-based thermoplastic resin composition.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, a vinyl copolymer obtained by polymerizing a vinyl monomer mixture by using a specific method. When preparing a thermoplastic resin composition in which a rubber-containing graft polymer is dispersed, a specific condition is satisfied when preparing a thermoplastic resin composition in which the rubber-containing graft polymer is dispersed, thereby further satisfying specific physical properties, thereby being excellent in transparency, chemical resistance, and color tone. The present inventors have found that a thermoplastic resin composition having excellent stability can be obtained, and have reached the present invention.

That is, the thermoplastic resin composition of the present invention contains 5 to 40% by weight of an aromatic vinyl monomer (a1) and 30 to 8 of an unsaturated carboxylic acid alkyl ester monomer (a2).
0% by weight, vinyl cyanide monomer (a3) 10 to 50
% By weight and other monomers copolymerizable therewith (a4)
Vinyl monomer mixture (a) containing 0 to 40% by weight
Is obtained by graft-polymerizing one or more vinyl monomers (c) in the presence of a rubbery polymer (b) to a vinyl copolymer (A) obtained by continuous bulk polymerization or continuous solution polymerization of A thermoplastic resin composition in which the graft copolymer (B) is dispersed, wherein the proportion of the acrylonitrile monomer unit in the acetone-soluble component of the thermoplastic resin composition in the triple sequence is as described above. It is characterized by being 10% by weight or less based on the acetone-soluble matter.

The thermoplastic resin composition of the present invention has a haze value of 30% or less, and a rubbery polymer component constituting the graft copolymer (B) and the acetone-soluble component. The difference in refractive index is within 0.03,
When the solubility parameter of the vinyl copolymer (A) is 1
0.5 to 12.5 (cal / ml) ^1/2 , and the acid value of the acetone-soluble component is 0.01 to ¹ mgKOH / g.
Wherein the vinyl monomer mixture (a) and the vinyl monomer mixture (c) are an unsaturated carboxylic acid monomer (however, an unsaturated carboxylic acid alkyl ester monomer (a2)
(A5) is not substantially contained, and the vinyl copolymer (A) is obtained by continuous bulk polymerization or continuous solution polymerization.
And then a vinyl copolymer (A) in a molten state
, A graft copolymer (B) is added thereto, and a thermoplastic resin composition is produced by a method of melt-mixing. In the course of or after the demonomerization step in the step of producing the copolymer (A), adding the graft copolymer (B) to the vinyl copolymer (A) in the molten state; -Based copolymer (A)
It is preferable that the graft copolymer (B) is in a semi-molten state or a molten state when it is added to the polymer, and when these conditions are satisfied, it is expected that a more excellent effect is obtained. Can be.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, specific examples of the aromatic vinyl monomer (a1) used in the vinyl copolymer (A) include styrene, α-methylstyrene, p-methylstyrene, Vinyltoluene, t-butylstyrene,
o-ethylstyrene, o-chlorostyrene and o, p
-Dichlorostyrene and the like, and styrene and α-methylstyrene are particularly preferable. One or more of these can be used.

In the vinyl monomer mixture (a) forming the vinyl copolymer (A), 5 to 40% by weight, preferably 10 to 30% by weight of the aromatic vinyl monomer (a1) is used. Must be used in the range. If it is less than the above range, mechanical properties such as Izod impact strength and rigidity will be remarkably reduced, and if it is more than the above range, transparency will be remarkably reduced.

In the present invention, the vinyl copolymer (A)
Specific examples of the unsaturated carboxylic acid alkyl ester-based monomer (a2) used for (a) include methyl (meth) acrylate, ethyl (meth) acrylate, and n (meth) acrylate.
-Propyl, n-butyl (meth) acrylate, (meth)
Examples include t-butyl acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate and 2-chloroethyl (meth) acrylate, with methyl methacrylate being particularly preferred. . One or more of these can be used.

In the vinyl monomer mixture (a) forming the vinyl copolymer (A), 30 to 80% by weight of the unsaturated carboxylic acid alkyl ester monomer (a2) is used.
Preferably, it must be used in the range of 35 to 75% by weight. If it is less than the above range, it is difficult to obtain transparency, and if it exceeds the above range, the chemical resistance tends to be significantly reduced.

In the present invention, the vinyl copolymer (A)
Specific examples of the vinyl cyanide-based monomer (a3) used include acrylonitrile, methacrylonitrile, ethacrylonitrile and the like, and acrylonitrile is particularly preferable. One or more of these can be used.

In the vinyl monomer mixture (a) forming the vinyl copolymer (A), 10 to 50% by weight, preferably 12 to 4% by weight of the vinyl cyanide monomer (a3) is used.
It must be used in the range of 0% by weight. If it is less than the above range, the chemical resistance is remarkably reduced, and if it exceeds the above range, the desired color stability tends to be not obtained.

In the present invention, the vinyl copolymer (A)
The other copolymerizable monomer (a4) used for the above is not particularly limited, but maleimide compounds such as N-methylmaleimide, N-cyclohexylmaleimide and N-phenylmaleimide, and unsaturated amides such as acrylamide and the like can be used. Among them, N-phenylmaleimide is preferably used. One or more of these can be used.

The vinyl monomer mixture (a) is prepared by mixing an acidic monomer such as an unsaturated carboxylic acid monomer (excluding the unsaturated carboxylic acid alkyl ester monomer (a2)) (a5). It is particularly preferable not to substantially contain the same in order to adjust the acid value of the acetone-soluble component in the thermoplastic resin composition and to improve the color tone. Here, “substantially not contained” means that these acidic monomers are not intentionally added as a monomer mixture, for example, 0.01% or more of the monomer mixture (a). The addition can be considered an intentional addition. In addition, the monomer mixture (a)
Unsaturated carboxylic acid derived from impurities in each monomer of, for example, unsaturated carboxylic acid alkyl ester-based monomer (a
Less than 0.01% of unsaturated carboxylic acid contained as an impurity in 2) is not intentionally added. As the unsaturated carboxylic acid monomer (a5), acrylic acid,
Methacrylic acid and the like are exemplified.

In the vinyl monomer mixture (a) forming the vinyl copolymer (A), the other copolymerizable monomer (a4) can be used in the range of 0 to 40% by weight, Particularly, from the viewpoint of chemical resistance, it can be used in the range of 0 to 30% by weight.

In the present invention, the thermoplastic resin composition preferably has a haze value of 30% or less, more preferably 15% or less.
%, The effect is remarkable when applied to those having a percentage of less than or equal to%.

The vinyl monomer mixture (a) has a solubility parameter of the vinyl copolymer (A) of 10.5 to 1
It is preferable to select the composition of each monomer so as to be 2.5 (cal / ml) ^1/2 . The definition of the solubility parameter here is shown in (Equation 1) below.

Δ = (ΣΔEi · X / ΣΔVm · X) ^1/2 (Equation 1) δ: Solubility parameter of vinyl copolymer (A) ((cal / ml) ^1/2 ) X: Vinyl copolymer Molar fraction (%) of the copolymer component constituting the union (A) ΔEi: Evaporation energy (cal / mol) of the copolymer component constituting the vinyl copolymer (A) ΔVm: Vinyl copolymer (A) )) (Molecular capacity (ml / mol)) The above (Equation 1) and the numerical values of ΔEi and ΔVm are described in
Burrell, Offic. Dig. A. J. To
rtorello, M .; A. Kinsella, J. et al. C
oat. Technol. It is quoted from. In view of the chemical resistance and mechanical properties of the thermoplastic resin composition, the solubility parameter of the vinyl copolymer (A) is 1
0.5 to 12.5 (cal / ml) ^1/2 is preferred. More preferably, 10.7-12.3 (cal / ml)
^1/2 .

In the present invention, the acid value of the acetone-soluble component contained in the thermoplastic resin composition is 0.01 to 1 m.
gKOH / g is preferable in terms of transparency, impact resistance, rigidity, and color tone stability.

Further, the weight ratio (φST / φMMA) of the aromatic vinyl monomer (a1) and the unsaturated carboxylic acid alkyl ester monomer (a2) in the monomer composition constituting the acetone-soluble component. In the composition distribution of the formula (1), the content of the acetone-soluble component in the range of 0.75 to 1.2 times the average value of the weight ratio (φST / φMMA) is 80% by weight or more. It is preferable to suppress a decrease in transparency of the thermoplastic resin composition when an acid component is contained due to hydrolysis of the acid alkyl ester-based monomer (a2). In addition, within the range of 0.75 to 1.2 times the average value, 9
The content is more preferably 0% by weight or more, and most preferably 95% by weight or more.

The monomer composition of the acetone-soluble component is 5 to 40% by weight of the aromatic vinyl monomer (a1), 30 to 80% by weight of the unsaturated carboxylic acid alkyl ester monomer (a2), 10 to 50% by weight of vinyl chloride monomer (a3)
And other monomers copolymerizable therewith (a4) 0 to 40
It is preferable that the content is by weight so that the transparency, color tone, impact resistance and the like of the resin composition can be improved in a better balance.

The composition of the acetone-soluble component is FT-IR
What is necessary is just to determine quantitatively by the following peaks appearing in the chart. Aromatic vinyl monomer (a1): peak at 1605 cm -1 attributed to vibration of benzene nucleus, unsaturated carboxylic acid alkyl ester monomer (a
2): peak at 1730 cm -1 attributed to C ＝ O stretching vibration of the carbonyl group of the ester; vinyl cyanide monomer (a3): peak at 2240 cm -1 attributed to -C≡N stretching; The acetone-soluble component is mainly composed of vinyl copolymer (A)
However, the graft copolymer (B) partially includes a resin component derived from a copolymer portion polymerized from the vinyl monomer mixture (c) in the graft copolymer (B). Therefore, in order to control the composition of the acetone-soluble component within the above-mentioned predetermined range, it is effective to control the composition of the vinyl copolymer (A), which is the main component thereof, within the above-mentioned predetermined range. Furthermore, it is preferable that the composition of the copolymer portion polymerized from the vinyl monomer mixture (c) is also controlled within the above-mentioned predetermined range.

Further, (φST) in acetone-soluble matter
/ ΦMMA), that is, the weight ratio of the aromatic vinyl monomer (a1) and the unsaturated carboxylic acid alkyl ester monomer (a2) constituting the acetone-soluble component, and the weight ratio thereof ( 0.75 of the average of φST / φMMA)
The fact that the content of the acetone-soluble component is not less than 80% by weight within the range of 1.2 times means that the composition distribution of the acetone-soluble component is narrow, and the composition distribution condition is as follows.
It is preferable to further increase the transparency of the obtained thermoplastic resin composition.

In the thermoplastic resin composition of the present invention,
The presence of a trace amount of the copolymerized acid component in the matrix resin is preferable because it gives better physical properties. That is, the acid value of the acetone-soluble component in the resin composition part is 0.1.
Impact resistance, rigidity,
Preferred from the point of color tone. It is more preferably 0.012 to 0.5 mgKOH / g, particularly preferably 0.015 to 0.1 mgKOH / g, from the viewpoint of color tone and physical balance.

The method for controlling the acid value within the above range in the present invention is not particularly limited, but from the viewpoint of minimizing deterioration of the color tone of the obtained thermoplastic resin composition, a vinyl copolymer ( The vinyl monomer mixture (a) as the raw material of A) and / or the vinyl monomer mixture (c) as the raw material of the rubber-containing graft copolymer (b) are unsaturated carboxylic acid monomer (A5) and the like, substantially free of an acidic monomer such as a monomer (excluding the unsaturated carboxylic acid alkyl ester monomer (a2)), and an unsaturated carboxylic acid alkyl ester monomer during the process It is particularly preferable to control the acid value within a predetermined range by hydrolyzing (a2). Above all, vinyl monomer mixture (a)
And the vinyl monomer mixture (c) is substantially an acidic monomer such as an unsaturated carboxylic acid monomer (excluding the unsaturated carboxylic acid alkyl ester monomer (a2)) (a5). Is not particularly preferred.

The refractive index of the acetone-soluble component of the thermoplastic resin composition according to the present invention is not particularly limited. However, from the viewpoint of the transparency of the thermoplastic resin composition, the refractive index is substantially a rubber polymer ( Preferably it is the same as or narrowly different from b). As a specific range, the difference in the refractive index between the vinyl copolymer (A) and the rubbery polymer (b) is preferably suppressed to 0.03 or less, more preferably 0.01 or less.

The reduced viscosity (ηsp / c) of the vinyl copolymer (A) in the present invention is not particularly limited.
-1.0 dl / g, particularly preferably in the range of 0.2-0.7 dl / g, from the viewpoint of the balance between impact resistance and moldability.

The weight ratio of the aromatic vinyl monomer (a1) to the unsaturated carboxylic acid alkyl ester monomer (a2) in the vinyl copolymer (A) (φST / φ
MMA), the weight ratio (φST / φ
It is preferable that the range of 0.75 to 1.2 times the average value of (MMA) contains a portion of 80% by weight or more of the vinyl copolymer (A).

In order to control the transparency and color stability of the thermoplastic resin composition obtained and to control the properties of the thermoplastic resin composition to a predetermined value, the vinyl copolymer (A) of the present invention is used. The continuous bulk polymerization or the continuous solution polymerization is used as the polymerization method.

In the present invention, the method of performing continuous bulk polymerization or continuous solution polymerization in the step of producing the vinyl copolymer (A) by copolymerizing the vinyl monomer mixture (a) is not particularly limited, and is optional. Method can be adopted,
For example, after polymerization in a polymerization tank, a method of removing monomers (desolvent / devolatilization) can be employed.

As the polymerization tank, various stirring blades, for example, paddle blades, turbine blades, propeller blades, bulmar blades,
A mixed-type polymerization tank having a multistage blade, an anchor blade, a max blend blade, a double helical blade, or the like, or various tower-type reactors can be used. Also, multi-tube reactors,
A kneader-type reactor, a twin-screw extruder, or the like can be used as a polymerization reactor (for example, assessment of polymer production process 10 “Assessment of impact-resistant polystyrene”, Society of Polymer Science, January 26, 1989, etc.) See). These polymerization tanks (reactors) are used in one (tank) or in two or more (tanks), and if necessary, two or more kinds of reactors may be used in combination. Above all, two or less (tank) or less are preferable in that the composition distribution of the acetone-soluble component of the obtained thermoplastic resin composition is narrowed, and the triple sequence ratio of the acrylonitrile monomer unit is kept low. In particular, a one-tank complete mixing type polymerization tank is preferably selected.

[0038] The reaction mixture obtained by polymerization in these polymerization tanks or reactors is usually then subjected to a demonomerization step to remove monomers, solvents 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 vent holes under heating or normal pressure or reduced pressure, and a plate-fin type heater such as a centrifugal type is built in a drum. To remove volatile components using a centrifugal type thin film evaporator, to remove volatile components using a multi-tube heat exchanger, to remove volatile components by flashing into a vacuum tank Any of these methods can be used, but a single-screw or twin-screw extruder having a vent is particularly preferably used.

FIG. 1 is a schematic longitudinal sectional view showing one embodiment of an apparatus for carrying out the method of the present invention by a method of continuous mass polymerization and resin mixing. A reaction tank (1) for producing the vinyl copolymer (A) by continuous bulk polymerization, and a preheater (for heating the vinyl copolymer (A) obtained by polymerization to a predetermined temperature) 2) and a twin-screw extruder-type demonomer machine (3) having a vent port (31) for demonomerization is connected, and the graft copolymer ( B) A twin screw extruder type feeder (5) for addition is connected.

In FIG. 1, the reaction product continuously supplied from the reaction tank (1) is heated by a preheater (2).
Then, it is supplied to a twin-screw extruder type demonomer machine (3),
A volatile component such as a monomer is removed from the system from the vent port (31) at about 150 to 280 ° C. under normal pressure or reduced pressure. This removal of volatile components is carried out when the amount of unreacted monomer is a predetermined amount,
For example, the process is performed until the content becomes 10% by weight or less, more preferably 5% by weight or less.

In FIG. 1, an addition port from the feeder (5) is opened at a position near the downstream side in the middle of the demonomerizer (3), and a predetermined temperature (for example, 100 to 220 ° C.).
) Is added into the system.
This feeder (5) is provided with a heating device,
It is preferable to heat the graft copolymer (B) to be added 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. Also,
As this feeder, a single-screw or twin-screw extruder-type feeder having a heating device can be used.

At the position where the supply port of the graft copolymer (B) is connected, the content of the unreacted monomer is 10%.
It is preferable to reduce the rubber component to not more than 5% by weight, more preferably to not more than 5% by weight, in order to prevent the thermal deterioration of the rubber component during the subsequent operation for removing the unreacted monomer.

After the vinyl copolymer (A) and the graft copolymer (B) are melt-mixed in the melt-kneading zone (4) of the twin-screw extruder type demonomerizer (3), the discharge port ( From 6), the resin composition is discharged out of the system.

Further, a water inlet (41) is preferably provided in the melt-kneading area (4), and a predetermined amount of water is preferably added. The injected water and the remaining monomer are supplied to a vent port (42) provided further downstream. ).

In the continuous bulk polymerization or solution polymerization of the vinyl copolymer (A), thermal polymerization without using an initiator, initiator polymerization using an initiator, thermal polymerization and initiation It is also possible to use agent polymerization 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 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 these initiators are used, they are used alone or in combination of two or more. 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), a chain transfer agent such as mercaptan or terpene may be used. Specific examples thereof include n-octyl mercaptan and t-dodecyl mercaptan , N-
Dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, terpinolene and the like. When using these chain transfer agents, 1
Used in combination of two or more species. Especially n-
Octyl mercaptan, t-dodecyl mercaptan, n
-Dodecyl mercaptan is preferably used.

When the vinyl copolymer (A) is produced by a continuous solution polymerization method, the amount of the solvent is not particularly limited.
Less than 20% by weight, more preferably less than 20% by weight of solvent is used. The solvent used is not particularly limited, but ethylbenzene or methylethylketone is preferred from the viewpoint of polymerization stability, and ethylbenzene is particularly preferred.

The rubbery polymer (b) used for the graft copolymer (B) in the present invention is not particularly limited.
Specific examples include polybutadiene, poly (butadiene-
Styrene), poly (butadiene-acrylonitrile),
Polyisoprene, poly (butadiene-butyl acrylate), poly (butadiene-methyl methacrylate), poly (butyl acrylate-methyl methacrylate), poly (butadiene-ethyl acrylate), ethylene-propylene rubber, ethylene-propylene- Diene rubber, poly (ethylene-isoprene), poly (ethylene-methyl acrylate) and the like. These rubbery polymers (b) are used alone or in a mixture of two or more. Among them, the use of polybutadiene, poly (butadiene-styrene), poly (butadiene-acrylonitrile), and ethylene-propylene rubber is preferable in terms of impact resistance.

The content of the rubbery polymer (b) constituting the graft copolymer (B) is not particularly limited.
The range of 0 to 80 parts by weight, particularly 35 parts by weight to 60 parts by weight is preferable. When the amount is less than 20 parts by weight, the impact strength of the obtained thermoplastic resin composition decreases, and when it exceeds 80 parts by weight, the melt viscosity increases. It is not preferable because moldability is deteriorated.

The weight average particle size of the rubbery polymer (b) is from 0.1 to 1.5 μm in view of impact resistance, moldability, flowability and appearance of the thermoplastic resin composition to be obtained.
Preferably it is in the range of 0.15 to 1.2 μm.

The composition of the vinyl monomer mixture (c), which is a raw material for the polymerization of the graft component (d) of the graft copolymer (B), is not particularly limited, but the color tone and resistance of the thermoplastic resin composition obtained are not limited. From the viewpoint of the balance between physical properties of impact strength and rigidity, 5 to 40% by weight of the aromatic vinyl monomer (a1) and the unsaturated carboxylic acid alkyl ester monomer (a2) 30
To 80% by weight, vinyl cyanide monomer (a3)
50% by weight and other monomers copolymerizable therewith (a
4) Preferably, it contains 0 to 40% by weight. The monomer composition of the vinyl monomer mixture (c) may be the same as or different from the vinyl monomer mixture (a) of the vinyl copolymer (A). .

Further, the unsaturated carboxylic acid monomer (c) is also added to the vinyl monomer mixture (c) as in the case of the vinyl monomer mixture (a) as a raw material for the polymerization of the styrene copolymer. However, the unsaturated carboxylic acid alkyl ester monomer (a
(2) Excluding the fact that it does not substantially contain an acidic monomer such as (a5) in order to adjust the acid value of the acetone-soluble component in the thermoplastic resin composition to a desired level and to improve the color tone Is particularly preferred. Here, “substantially not contained” is the same as in the case of the vinyl-based monomer mixture (a) as a polymerization raw material of the styrene-based copolymer.

From the viewpoint of transparency of the obtained thermoplastic resin composition, the refractive index of the graft component (d) of the graft copolymer (B) is substantially the same as that of the rubbery polymer (b). It is preferable to adjust the composition of the vinyl monomer mixture (c) so as to make a slight difference. As a specific range, the difference between the refractive indices of the graft component (d) and the rubbery polymer (b) is preferably suppressed to 0.03 or less, more preferably 0.01 or less.

One or more graft copolymers (B) can be used, but when a blend of two or more is used, the rubbery polymer (b) contained in each component is used.
It is preferable from the viewpoint of transparency of the obtained thermoplastic resin that the refractive index of the graft component (d) is adjusted to substantially match.

The reduced viscosity (ηsp / c) of the graft component constituting the graft copolymer (B) in the present invention is not particularly limited, but is 0.05 to 1.2 dl / g, particularly 0.1.
It is preferable to be within the range of 0.7 dl / g from the viewpoint of the balance between impact resistance and moldability.

The graft ratio of the graft copolymer (B) is not limited, but is preferably 5 to 150% by weight from the viewpoint of impact resistance.
Preferably 10 to 100% by weight is used.

The method of graft polymerization at the time of producing the graft copolymer (B) is not limited, but may be produced by any known method such as emulsion polymerization, suspension polymerization, continuous bulk polymerization, and continuous solution polymerization. It is preferably produced by an emulsion polymerization method or a bulk polymerization method. Above all, in order to suppress deterioration and coloring of the rubber component due to excessive heat history, and to add the unsaturated carboxylic acid alkyl ester monomer (a2) in the melt kneading step with the vinyl copolymer (A). In order to control the decomposition, the emulsion copolymer is most preferably produced from the viewpoint that the content of the emulsifier and the amount of water in the graft copolymer (B) can be easily adjusted.

In the usual emulsion polymerization, a monomer mixture is subjected to emulsion graft polymerization 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, mistyphosphate, 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. Among them, for controlling hydrolysis, potassium salts and sodium salts of palmitic acid, stearic acid, and oleic acid are preferably used. One or two of these emulsifiers may be used.
Used in combination of more than one species.

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

The graft copolymer (B) produced by emulsion graft polymerization is then added with a coagulant to coagulate the latex, and then the graft copolymer (B) is recovered. Acids or water-soluble salts are used as coagulants, and specific examples thereof include sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid, calcium chloride,
Magnesium chloride, barium chloride, aluminum chloride,
Examples include magnesium sulfate, aluminum sulfate, ammonium ammonium sulfate, aluminum potassium sulfate, and sodium aluminum sulfate. These coagulants are used in one kind or in a mixture of two or more kinds. The graft copolymer (B) slurry obtained by coagulating the latex component can be used as it is or through a dehydration / washing step in the form of a slurry or a water-containing cake. After the process, it becomes powder shape,
It is preferable to add to the vinyl copolymer (A) in a powder state and in a molten state from the viewpoint of handleability in the process.

When added to the vinyl copolymer (A),
The amount of the emulsifier contained in the material on the side of the graft copolymer (B) controls the hydrolysis reaction of the unsaturated carboxylic acid ester monomer (a2) during the process, and the amount of acetone in the thermoplastic resin composition obtained is In order to make the acid value of the soluble component within the predetermined range of the present invention, the content is preferably 0.1 to 5% by weight, and particularly preferably 0.1 to 5% by weight.
15 to 2% by weight is preferred. Heretofore, no knowledge has been obtained that an emulsifier can be used to suppress the hydrolysis of a polymer, and it was generally considered that the emulsifier should be excluded from resin products as much as possible. However, in the present invention, as an effective means for controlling the acid value of the acetone-soluble component of the thermoplastic resin composition within a predetermined range, it is effective to positively contain an emulsifier within the above range. .

The method for adjusting the content of the emulsifier in the graft copolymer (B) within a predetermined range is not particularly limited. For example, the method for dehydrating and washing the slurry-like graft copolymer (B) after coagulation is used. The desired emulsifier content can be adjusted by controlling the number of times and the temperature and amount of the washing water. In addition, for example, it is also possible to adjust by adding an emulsifier to the graft copolymer (B) separately.

The amount of water (moisture content) contained in the graft copolymer (B) when added to the vinyl copolymer (A) depends on the amount of the unsaturated carboxylic acid ester monomer ( In order to control the hydrolysis reaction of a2) and keep the acid value of the acetone-soluble component of the obtained thermoplastic resin composition within the predetermined range of the present invention, the content is preferably 0.1 to 5% by weight, particularly preferably 0.1 to 5% by weight. 15 to 2% by weight is preferred.

The method for adjusting the water content in the graft copolymer (B) to be within a predetermined range is not particularly limited. For example, the dehydration time, drying temperature, air volume, etc. of the graft copolymer (B) may be controlled. Can be adjusted to a desired moisture content value. In addition, for example, water can be separately added to the graft copolymer (B) to adjust the water content.

Further, the graft copolymer (B) can 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 that has come out of the demonomerizer can be directly added to the vinyl copolymer (A), or it can be simply added in advance. Although it is possible to add the separated graft copolymer (B) to the vinyl copolymer (A), the graft copolymer (B) is usually in a molten state coming out of the demonomer machine from the viewpoint of preventing thermal deterioration and continuation of the process. It is more preferable to directly add the graft copolymer (B).

The method of mixing the vinyl copolymer (A) and the graft copolymer (B) is not particularly limited, but from the viewpoint of color tone, impact resistance, etc., during the continuous bulk polymerization process or during the continuous solution polymerization process. After the addition of the graft copolymer (B) to the vinyl copolymer (A) in the molten state, a method of melt-mixing is preferably selected. At that time, it is preferable to add 90 to 5 parts by weight of the graft copolymer (B) to 10 to 95 parts by weight of the vinyl copolymer (A) in a molten state, and more preferably, to add the vinyl copolymer ( A) 3
After adding 70 to 5 parts by weight of the graft copolymer (B) to 0 to 95 parts by weight, the mixture is melt-mixed. It is preferable to continuously add the graft copolymer (B). At this time, the addition of the graft copolymer (B) is such that the amount of the remaining monomer is 10 or more during the demonomerization step or after the demonomerization step of the continuous bulk polymerization process for the vinyl copolymer (A).
To be performed at the time when the content becomes 5% by weight or less, more preferably 5% by weight or less, in order to suppress the deterioration due to the thermal history of the rubber component during the subsequent demonomerization operation, and to further improve the color tone and impact resistance. Is particularly preferred.

During the melt kneading step after mixing the vinyl copolymer (A) and the graft copolymer (B), water is added to the thermoplastic resin composition in an amount of 0.1 to 5 wt. % Is particularly preferable in order to more easily control the hydrolysis reaction of the unsaturated carboxylic acid ester-based monomer (a2) in the process.

The mixing after the addition of the graft copolymer (B) to the vinyl copolymer (A) is preferably carried out by melt mixing in order to sufficiently exhibit physical properties such as impact resistance. 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 adding the graft copolymer (B) is not particularly limited, and it is possible to add it by any method. Usually, it is continuously added using various feeders, for example, a belt type feeder, a screw type feeder, a single screw extruder, a twin screw extruder, and the like. A single-screw extruder and a twin-screw extruder each having a discharge end connected to a portion are particularly preferably used. It is preferable that these continuous addition apparatuses have a resin fixed supply structure. It is preferable to add the graft copolymer (B) in a semi-molten or molten state in order to improve the mixing state, since the continuous addition apparatus has a heating apparatus. For this purpose, an extruder having a heating device can be used.

In the thermoplastic resin composition of the present invention, the proportion of the acrylonitrile monomer units in the acetone-soluble component in the acetone-soluble component is 10% by weight or less based on the acetone-soluble component. The triple sequence of acrylonitrile monomer units is a segment in a copolymer contained in an acetone-soluble component represented by the following (Equation 2), and a copolymer having such a segment is heated at a high temperature. In the state exposed to, the intramolecular cyclization reaction shown in the following (formula 3) proceeds, which causes coloring.

Embedded image

If the ratio of the acrylonitrile monomer unit in the triple sequence exceeds 10% by weight based on the acetone-soluble matter, the resulting thermoplastic resin composition will have poor color tone stability during melting. The ratio of the triple sequence is preferably less than 8% by weight and more preferably 5% by weight or less from the viewpoint of color tone stability. Such a thermoplastic resin composition in which the proportion of the acrylonitrile monomer unit in the acetone-soluble matter is controlled to 10% by weight or less is, for example, as described above, a triple sequence of acrylonitrile monomer units. Is controlled by using a vinyl copolymer (A) in which the ratio is controlled to 10% by weight or less.

The thermoplastic resin composition of the present invention contains vinyl chloride, polyethylene, and the like as long as the object of the present invention is not impaired.
Polyolefins such as polypropylene, polyamides such as nylon 6 and nylon 66, polyesters such as polyethylene terephthalate, polybutylene terephthalate and polycyclohexanedimethyl terephthalate, polycarbonates and various elastomers can be added to improve the performance as a molding resin. In addition, if necessary, an antioxidant such as a hindered phenol type, a sulfur-containing organic compound type, a phosphorus-containing organic compound type, a heat stabilizer such as a phenol type or an acrylate type, a benzotriazole type, a benzophenone type, a salicylate type, etc. UV absorber,
Various stabilizers such as organic nickel-based and hindered amine-based light stabilizers; metal salts of higher fatty acids; lubricants such as higher fatty acid amides; plasticizers such as phthalic acid esters and phosphate esters; polybromodiphenyl ether; Halogen-containing compounds such as bromobisphenol-A, brominated epoxy oligomers, brominated polycarbonate oligomers, phosphorus compounds, flame retardants and flame retardant assistants such as antimony trioxide, antistatic agents, carbon black, titanium oxide, pigments and the like. A dye or the like can be added. Further, reinforcing agents and fillers such as glass fibers, glass flakes, glass beads, carbon fibers, and metal fibers can be added.

The method of adding these additives is not particularly limited, and they can be continuously added together with the graft copolymer (B), and the vinyl copolymer (A)
Various methods can be used, such as adding a post-process after preparing mixed pellets of the polymer and the graft copolymer (B).

The thermoplastic resin composition of the present invention thus obtained has excellent balance of transparency, chemical resistance and color stability, mechanical strength balance such as impact resistance and rigidity, moldability and cost performance. It can be widely used in application fields such as home appliances, communication-related equipment and general goods.

[0077]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, which do not limit the present invention. Unless otherwise specified, “%” indicates% by weight and “parts” indicates “parts by weight”. A method for analyzing the resin characteristics of the thermoplastic resin composition will be described below. (1) Weight average rubber particle size of rubbery polymer "Rubber Age Vol.88 p.484-490 (1960)," by E.Schmid
t, PHBiddison '' described sodium alginate method, i.e., utilizing the fact that the polybutadiene particle size to be creamed differs depending on the concentration of sodium alginate, the cumulative weight fraction of the creamed weight ratio and the cumulative weight fraction of the sodium alginate concentration A method of obtaining a particle size of 50%,
by. (2) Graft ratio of graft copolymer (B) 100 ml of acetone was added to a predetermined amount (m; about 1 g) of the graft copolymer (B), which was vacuum-dried at 80 ° C for 4 hours, and heated at 70 ° C in a hot water bath. The solution was refluxed for 3 hours.
After centrifugation at 00 rpm (10000 G) for 40 minutes, the insoluble matter was filtered, and the insoluble matter was vacuum-dried at 80 ° C. for 4 hours, and the weight (n) was measured. The graft ratio was calculated from the following equation. Here, L is the rubber content of the graft copolymer. Graft rate (%) = ｛[(n) − (m) × L] /
[(M) × L]｝ × 100

(3) Emulsifier Content of Graft Copolymer (B) About 20 g of the graft copolymer (B) which was vacuum-dried at 80 ° C. for 4 hours was precisely weighed, and 10 times the amount of 10% sulfuric acid was added. And boiled in a 500 ml beaker for 30 minutes. This was separated by filtration through a 100-mesh wire net, and the residual solid content was taken.
Washing for 1 minute in 00 ml of ion-exchanged water and filtration were repeated twice. This solid content was further divided into two and put into a round bottom flask, and 100 ml of methanol was added, respectively.
Reflux was performed in a hot water bath set at 70 ° C. for 3 hours. Further, the solution and the solid content were adjusted to 8800 rpm (10000 G).
For 40 minutes, and the filtrate obtained by filtering the supernatant was evaporated to dryness and further dried under vacuum at 80 ° C. for 4 hours to obtain a solid. This solid content was precisely weighed as the emulsifier contained in the graft copolymer (B), and the emulsifier content was calculated. (4) Moisture content of graft copolymer (B) A measurement sample was precisely weighed and measured using a Karl Fischer moisture meter. (5) Reduced viscosity ηsp / c of vinyl copolymer (A) A sample for measurement was dissolved in methyl ethyl ketone, and 0.4 g
The reduced viscosity ηsp / c was measured at 30 ° C. using a Ubbelohde viscometer as a / 100 ml methyl ethyl ketone solution. (6) Reduced viscosity of graft component (d) ηsp / c 200 ml of acetone was added to 1 g of the graft copolymer (B) which was vacuum-dried at 80 ° C for 4 hours, and refluxed in a 70 ° C water bath for 3 hours. This solution was added at 8800 rpm (10
After centrifugation at 000 G) for 40 minutes, the insoluble matter is filtered. The filtrate was concentrated with a rotary evaporator, and the precipitate was vacuum-dried at 80 ° C. for 4 hours, and the resulting solution was treated as a 0.4 g / 100 ml methyl ethyl ketone solution with an Ubbelohde viscometer at 30 ° C. in the same manner as (5). The reduced viscosity ηsp / c was measured.

(7) Monomer composition of acetone-soluble component 100 ml of acetone was added to 1 g of a sample of the resin composition, and the mixture was refluxed for 3 hours in a 70 ° C. water bath.
After centrifugation at 0 rpm (10000G) for 40 minutes,
Filter insolubles. The filtrate was concentrated by a rotary evaporator, and the precipitate was vacuum-dried at 80 ° C. for 4 hours (soluble matter in acetone) to prepare a film having a thickness of 30 ± 5 μm formed by a heating press set at 220 ° C. Using this film as a sample, the monomer composition was determined from the area of each peak appearing in a chart obtained by FT-IR analysis. The correspondence between each monomer and the peak is as follows. Methyl methacrylate monomer unit: peak at 3460 cm-1, which is an overtone peak of a peak at 1730 cm-1 attributed to C = O stretching vibration of the carbonyl group of the ester, methacrylic acid monomer unit: carbonyl group of carboxylic acid A peak at 1690 cm -1 attributed to the C = O stretching vibration of the styrene monomer unit: a peak at 1605 cm -1 attributed to the vibration of the benzene nucleus, an acrylonitrile monomer unit: -C≡N (8) φST / φMMA distribution of acetone-soluble matter 80 ml of methyl ethyl ketone was added to 2 g of a sample of acetone-soluble matter obtained in the same manner as in (7), and the mixture was allowed to stand at room temperature for 24 hours. , And cyclohexane was added little by little, and the weight of the precipitated vinyl copolymer was measured in order. Was used as a sample, and the monomer composition was determined by FT-IR in the same manner as in the above (7). And
Cumulative weight fraction of the precipitate relative to the acetone-soluble component used as the sample, the content of the aromatic vinyl monomer (a1) and the unsaturated carboxylic acid alkyl ester monomer (a2)
The weight ratio with the content (φST / φMMA) is plotted,
The ratio (% by weight) of the acetone-soluble component contained in the range of 0.75 to 1.2 times the average value of the entire acetone-soluble component was determined.

(9) Acid Value of Acetone-Soluble Content 100 ml of acetone was added to a 10 g sample of the resin composition, and the mixture was refluxed for 3 hours in a 70 ° C. water bath.
After centrifugation at 0 rpm (10000G) for 40 minutes,
Filter insolubles. The filtrate was gently poured into 2 L of methanol at room temperature while stirring to reprecipitate, and the supernatant was discarded to obtain a precipitate. This was further dissolved in 200 ml of acetone, reprecipitated again with 2 L of methanol, and the obtained precipitate was vacuum-dried at 80 ° C. for 4 hours to obtain a solid (acetone-soluble). Approximately 10 g of the acetone-soluble matter obtained by performing this operation on several samples was precisely weighed and placed in a 100 ml Erlenmeyer flask with a stopper. 40 ml of acetone was added thereto, and the mixture was stirred for 2 hours to be uniformly dissolved. To this solution, 3 drops of a phenolphthalein solution were added, and neutralization titration was performed with 1 / 10N KOH. Using this titration amount, an acid value was calculated according to the following equation. Neutralization titration was also performed on acetone stirred for 2 hours in the same manner as the measurement sample, and the titration was corrected using this as a blank.

(Equation 1) However, the values in the equation are as follows. X: titration (ml), X0: blank titration (ml),
W: Sample amount (g)

(8) Triad Sequence Ratio of Acrylonitrile Monomer Unit in Acetone-Soluble Content Acrylonitrile monomer appearing in ¹³ C-NMR was obtained by using the acetone-soluble content obtained by the same operation as in (7) above as a sample. Taking advantage of the fact that the signal shift of the α-carbon of a unit is slightly different depending on the difference of adjacent monomer species, the ratio of the triple sequence is quantified from the signal integrated value, and the acrylonitrile unit at the center of the triple sequence among all monomer units It was expressed as a weight fraction of a monomer unit. The measurement conditions are as follows.

Apparatus: JEOL JNM-GSX400 type Observation frequency: 100.5 MHz Solvent: DMSO-d ₆ concentration: 445 mg / 2.5 mL Chemical shift standard: Me ₄ Si temperature: 110 ° C. Observation width: 20000 Hz Data point: 32K flip angle : 90 ° (21 μs) pulsedelaytime: 5.0 s Number of accumulations: 7400 or 8400 Decoupling: gated decoupling (without NOE) Assignment of acrylonitrile sequence (A: acrylonitrile, S: styrene): -AAAA-118.6 ~
119.2 ppm -A-A-S- 119.3 to 120.2 ppm -S-A-S- 120.2 to 121.3 ppm

(9) Triad Sequence Ratio of Acrylonitrile Monomer Unit in Vinyl Copolymer (A) Instead of the above acetone-soluble component, vinyl copolymer (A)
Was determined by the same operation as in the above (8) except that was used as a sample. (10) Refractive Index of Vinyl Copolymer (A), Graft Component (d) or Acetone-Soluble Component A small amount of 1-bromonaphthalene is dropped on a measurement sample, and the refractive index is measured using an Abbe refractometer under the following conditions. It was measured. Light source: sodium lamp D line, measurement temperature: 20 ° C. As a sample of the graft component (d), a vacuum-dried precipitate obtained in the same manner as in the above (6) was used.
As a sample for measuring the acetone-soluble component, an acetone-soluble component obtained in the same manner as in the above (7) was used.

(11) Refractive index of rubbery polymer (b) From the literature, the following values were used. As for the copolymer rubber,
Identification is performed by FT-IR, viscoelasticity measurement, and the like, and the refractive index (nD) of the copolymer rubber can be obtained from each copolymer component by the following formula. Refractive index of polybutadiene: 1.516 nD = 1.516 · MB + 1.594 · MS + 1.51
6. MA However, the values in the equation are as follows. nD: refractive index of copolymer rubber, MB: butadiene content (w
t :), MS: styrene content (wt%), MA: acrylonitrile content (wt%)

(12) Color Tone (YI Value) of Resin Composition Measured in accordance with JIS K7103. (13) Transparency (Total Light Transmittance, Haze Value) of Resin Composition 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. (14) Izod impact strength of resin composition Measured according to ASTM D256 (23 ° C., with V notch). (15) Tensile strength of resin composition Measured according to ASTM 638.

(16) Chemical Resistance Press-formed test pieces (127 × 12.7 × 1.5 m
m) 12 is fixed along the 1/4 elliptical jig 11 as shown in FIG. 2, and then a chemical (ethanol, isopropanol, or liquid detergent “top”) is applied to the entire surface of the molded product, Spread a paper wiper (“Kimwipe” manufactured by Crecia Co., Ltd.) from above, and allow the chemicals to fully penetrate the paper wiper. A molded article is put in a plastic bag together with the 1/4 elliptical jig 11 in a plastic bag to suppress evaporation of the drug, and the plastic bag is sealed. After standing for 24 hours in an environment of 23 ° C., the presence or absence of cracks and cracks was confirmed, the length of the crack generation point in the major axis direction (X mm) was measured, and the critical strain (ε%) was obtained by the following (Equation 4). ) Is calculated, and those having a value of less than 0.5% are evaluated as x, those having a value of 0.5% to 1.0% as Δ, and values of 1.0% to 1.0%.
Those with 2.0% were evaluated as ○, and those with more than 2.0% were evaluated as ◎.

(Equation 2) However, the symbols in Equation 4 and FIG. 2 are as follows. ε: Critical strain (%) a: Long axis of jig (mm) [127 mm] b: Short axis of jig (mm) [38 mm] t: Thickness of test piece (mm) [1.5 mm] X: Crack Long axis length of origin (mm)

(Reference Example) Graft Copolymer B-1: Polybutadiene latex (rubber particle diameter of 0.1%).
50 parts (solid content conversion), 180 parts of pure water, 0.4 parts of sodium formaldehyde sulfoxylate, 0.1 parts of sodium ethylenediaminetetraacetate
Part, ferrous sulfate 0.01 part and sodium phosphate 0.1 part.
1 part was charged into a reaction vessel, and the temperature was adjusted to 65 ° C. after the replacement with nitrogen.
Under stirring, 11.5 parts of styrene and 4.0 of acrylonitrile were used.
, 34.5 parts of methyl methacrylate and 0.3 part of n-dodecyl mercaptan were continuously added dropwise over 4 hours. At the same time, 0.25 part of cumene hydroperoxide and 2.5 emulsifiers of sodium oleate
And a mixture of 25 parts of pure water were continuously added dropwise over 5 hours, and after the completion of the addition, the mixture was maintained for another 1 hour to complete the polymerization.

The latex-like product obtained after the completion of the polymerization is poured into 2,000 parts of water at 95 ° C. to which 1.0 part of sulfuric acid has been added, while stirring, to coagulate the mixture. To obtain a coagulated slurry. This was centrifuged, washed in 2000 parts of water at 40 ° C. for 5 minutes, centrifuged, and dried in a hot air drier at 60 ° C. for 12 hours to prepare a powdery graft copolymer. The graft properties, the refractive index of the graft component, the emulsifier content, and the water content of the obtained graft copolymer (B-1) were as shown in Table 1.

B-2: Polymerization / coagulation / neutralization / washing / drying / separation was carried out in the same manner as in B-1 except that a vinyl monomer mixture having the composition shown in Table 1 and a polybutadiene latex were used. A graft copolymer (B-2) shown in Table 1 was prepared. Graft properties of the obtained graft copolymer,
Table 1 shows the refractive index, emulsifier content, and moisture content of the graft component.
As shown in FIG.

B-3: The coagulated slurry after polymerization / coagulation / neutralization was centrifuged in the same manner as in B-1.
The operation of washing in 2000 parts of water at 2000 ° C. for 10 minutes and centrifuging was repeated three times, followed by drying in a hot air dryer at 60 ° C. for 48 hours to obtain a powdery graft copolymer (B-3).
Was prepared. The graft properties of the obtained graft copolymer, the refractive index of the graft component, the content of the emulsifier, and the water content were as shown in Table 1.

Example 1 A 2 m ³ complete mixing type polymerization tank having a condenser for evaporating and refluxing monomer vapor and a helical ribbon blade, a single-screw extruder type preheater, and a twin-screw extruder type demonomer machine Polymerization and resin mixing were carried out using a continuous bulk polymerization apparatus consisting of a twin-screw extruder-type feeder having a heating device connected in tandem to the barrel section having a length of 1/3 from the tip of the demonomerizer.

First, 17.5 parts of styrene, 30.0 parts of acrylonitrile, 52.5 parts of methyl methacrylate, n-
A monomer mixture consisting of 0.15 parts of octyl mercaptan and 0.01 parts of di-t-butyl peroxide was mixed with 1
It is continuously fed to the polymerization tank at a rate of 50 kg / h and the polymerization temperature is 130
C. and the inside pressure of the tank was kept at 0.08 MPa to carry out continuous bulk polymerization. The polymerization rate of the polymerization reaction mixture in the polymerization tank is 74 to
Controlled between 76%.

After the polymerization reaction mixture was preheated by a single screw extruder type preheater, unreacted monomers were evaporated under reduced pressure from a vent port by a twin screw extruder type demonomer, and the recovered unreacted monomer was recovered. The mass was continuously refluxed to the polymerization vessel. The styrene / acrylonitrile / methyl methacrylate copolymer, whose apparent polymerization rate has risen to 99% or more at one third from the outlet end of the demonomerizer, is treated with a phenolic stabilizer by a twin-screw extruder type feeder. 0.225 kg / hour of a certain t-butylhydroxytoluene, 0.225 kg / hour of tri (nonylphenyl) phosphite as a phosphorus-based stabilizer, and half of the graft copolymer (B-1) produced in Reference Example. The melted product was fed at 60 kg / hour and melt-kneaded with a styrene / acrylonitrile / methyl methacrylate copolymer in a demonomerizer. During the melt-kneading process, water was supplied at a rate of 2 kg / hour at a point 1/6 from the outlet end of the demonomerizer. The water and other volatile components were further removed by evaporating under reduced pressure from a vent provided downstream of the demonomerizer. Thereafter, the molten polymer was discharged in a strand shape, and a resin composition pellet was obtained by a cutter. Table 3 shows the evaluation results of the resin properties.

Example 2 The composition of the monomer mixture was 17.5 parts of styrene, 30.0 parts of acrylonitrile, 52.5 parts of methyl methacrylate, and 0.1 part of n-octyl mercaptan.
Using a heated twin-screw extruder-type feeder of 15 parts and 0.01 part of di-t-butyl peroxide, the graft copolymer (B-2) produced in Reference Example in the semi-molten state in the rate shown in Table 2 The resin composition pellets were obtained in the same manner as in Example 1 except that the resin composition was supplied. Table 3 shows the evaluation results of the resin properties.

Example 3 The composition of the monomer mixture was 20.0 parts of styrene, 20.0 parts of acrylonitrile, 60.0 parts of methyl methacrylate, and 0.1 part of n-octylmercaptan.
Using a heated twin-screw extruder-type feeder of 15 parts and 0.01 part of di-t-butyl peroxide, the graft copolymer (B-1) produced in Reference Example in a semi-molten state at a rate shown in Table 2. The resin composition pellets were obtained in the same manner as in Example 1 except that the resin composition was supplied. Table 3 shows the evaluation results of the resin properties.

[Example 4] A 2 m ³ complete mixing type polymerization tank having a condenser for evaporating and refluxing monomer vapor and a helical ribbon blade, a single-screw extruder-type preheater, and a twin-screw extruder-type demonomer machine The polymerization was carried out using a continuous bulk polymerization apparatus consisting of

First, 20.0 parts of styrene, 20.0 parts of acrylonitrile, 60.0 parts of methyl methacrylate, n-
A monomer mixture consisting of 0.15 parts of octyl mercaptan and 0.01 parts of di-t-butyl peroxide was mixed with 1
It is continuously fed to the polymerization tank at a rate of 50 kg / h and the polymerization temperature is 130
C. and the inside pressure of the tank was kept at 0.08 MPa to carry out continuous bulk polymerization. The polymerization rate of the polymerization reaction mixture in the polymerization tank is 74 to
Controlled between 76%.

After the polymerization reaction mixture was preheated by a single screw extruder type preheater, unreacted monomers were evaporated under reduced pressure from a vent port by a twin screw extruder type demonomer, and the recovered unreacted monomer was recovered. The mass was continuously refluxed to the polymerization vessel. Thereafter, the molten polymer was discharged in a strand shape, and a vinyl copolymer (A) pellet was obtained with a cutter.

The obtained vinyl copolymer in pellet form (A) and the graft copolymer (B-1) produced in Reference Example
Was added in the proportions shown in Table 2, and 0.1 part of t-butylhydroxytoluene as a phenol-based stabilizer and 0.1 part of tri (nonylphenyl) phosphite as a phosphorus-based stabilizer were further added to dry blend After that, using a 40 mmφ extruder equipped with a water injection facility at 1/3 from the outlet end and a vent at 1/6 from the outlet end, water was added at a ratio of 1% by weight to the resin composition. 23 while injecting with
The mixture was melt-kneaded at 0 ° C. and extruded and pelletized to obtain resin composition pellets. Table 3 shows the evaluation results of the resin properties.

Example 5 A graft copolymer (B-3) produced in a reference example from a heated twin-screw extruder type feeder
Example 1 except that water was supplied in the semi-molten state at the speed shown in Table 2 and that water was not supplied to the demonomerizer.
In the same manner as in the above, a resin composition pellet was obtained. Table 3 shows the evaluation results of the resin properties.

Comparative Example 1 The composition of the monomer mixture was 24.0 parts of styrene, 5.0 parts of acrylonitrile, 71.0 parts of methyl methacrylate, and 0.1 part of n-octyl mercaptan.
5 parts and 0.01 part of di-t-butyl peroxide, and the graft copolymer (B-1) produced in Reference Example was heated in a semi-molten state using a heated twin-screw extruder type feeder.
The resin composition pellets were obtained in the same manner as in Example 1 except that the resin composition was supplied at the rate shown in Table 1. Table 3 shows the evaluation results of the resin properties.

Comparative Example 2 The composition of the monomer mixture was 10.0 parts of styrene, 60.0 parts of acrylonitrile, 30.0 parts of methyl methacrylate, and 0.1 part of n-octyl mercaptan.
Using a heated twin-screw extruder-type feeder of 15 parts and 0.01 part of di-t-butyl peroxide, the graft copolymer (B-1) produced in Reference Example in a semi-molten state at a rate shown in Table 2. The resin composition pellets were obtained in the same manner as in Example 1 except that the resin composition was supplied. Table 3 shows the evaluation results of the resin properties.

[0103]

[Table 1]

[0104]

[Table 2]

[0105]

[Table 3] As shown in Examples 1 to 5, it is understood that the thermoplastic resin composition specified in the present invention is excellent in all of transparency, color tone stability and chemical resistance. Particularly, in Examples 1 to 3, since the mixing method of the vinyl copolymer (A) and the graft copolymer (B) and the acid value in the acetone-soluble component are within the above-mentioned preferred ranges, the transparency is particularly high. , Color tone, impact resistance and rigidity were well-balanced in physical properties and excellent.

However, in the resin compositions obtained in Comparative Examples 1 and 2, the monomer composition constituting the vinyl copolymer (A) and the acrylonitrile triple ratio in the acetone-soluble matter were the same as those of the present invention. , One of transparency, color tone stability and chemical resistance was inferior.

[0107]

Industrial Applicability The thermoplastic resin composition of the present invention is excellent in transparency, chemical resistance and color tone stability, mechanical strength balance such as impact resistance and rigidity, moldability and cost performance. By utilizing these characteristics, it can be widely used in application fields such as home appliances, communication-related equipment and general goods.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing an embodiment of an apparatus for producing a resin composition of the present invention by a method of continuous bulk polymerization and resin mixing.

FIG. 2 is a 1/4 elliptical jig used for evaluating chemical resistance;
FIG. 2 is a longitudinal sectional view for explaining a method of using the same.

[Explanation of symbols]

 1: Reaction tank 2: Preheater 3: Twin screw extruder type demonomer machine 4: Melt kneading area 5: Twin screw extruder type feeder 11: 1/4 elliptical jig 12: Test piece 13: Chemical solution coated surface 14: Crack X: Distance from crack occurrence point

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 BC06W BC07W BG02W BG09W BN06X BN12X BN14X GC00 GQ00

Claims (10)

[Claims] 1. An aromatic vinyl monomer (a1) 5 to 40.
%, 30 to 80% by weight of unsaturated carboxylic acid alkyl ester monomer (a2), 10 to 50% by weight of vinyl cyanide monomer (a3) and other monomers copolymerizable therewith ( a4) A vinyl copolymer (A) obtained by continuous bulk polymerization or continuous solution polymerization of a vinyl monomer mixture (a) containing 0 to 40% by weight in the presence of a rubbery polymer (b) And a graft copolymer (B) obtained by graft-polymerizing one or more vinyl monomers (c) into the thermoplastic resin composition, wherein the thermoplastic resin composition is acetone-soluble. A thermoplastic resin composition, characterized in that the ratio of acrylonitrile monomer units present in the triad in a triple sequence is 10% by weight or less based on the acetone-soluble matter. 2. The thermoplastic resin composition according to claim 1, wherein the haze value is 30% or less. 3. The difference in refractive index between the rubbery polymer component constituting the graft copolymer (B) and the acetone-soluble component is within 0.03. 3. The thermoplastic resin composition according to 2. 4. The vinyl-based copolymer (A) has a solubility parameter of 10.5-12.5 (cal / ml) ^1/2.
The thermoplastic resin composition according to any one of claims 1 to 3, wherein 5. An acid value of the acetone-soluble component of 0.01 to 5.
The amount is 1 mgKOH / g.
The thermoplastic resin composition according to any one of the above. 6. The vinyl monomer mixture (a) and the vinyl monomer mixture (c) are each composed of an aromatic vinyl monomer (a
1) 5 to 40% by weight, unsaturated carboxylic acid alkyl ester monomer (a2) 30 to 80% by weight, vinyl cyanide monomer (a3) 10 to 50% by weight and others copolymerizable therewith Consisting of 0 to 40% by weight of the monomer (a4)
And an unsaturated carboxylic acid monomer (excluding the unsaturated carboxylic acid alkyl ester monomer (a2)) (a5)
Is a monomer mixture substantially free of:
The thermoplastic resin composition according to any one of the above. 7. A vinyl copolymer (A) is produced by subjecting a vinyl monomer mixture (a) to continuous bulk polymerization or continuous solution polymerization, followed by melting of the vinyl copolymer (A) The thermoplastic resin composition according to any one of claims 1 to 6, which is a rubber-reinforced styrene-based resin composition continuously produced by a method of adding a graft copolymer (B) to the mixture and melt-mixing the mixture. object. 8. During the demonomerization step or after the demonomerization step in the step of producing the vinylic copolymer (A) by performing the demonomerization following the polymerization of the vinylic monomer mixture (a), The thermoplastic resin composition according to claim 7, which is produced by adding a graft copolymer (B) to a vinyl copolymer (A) in a molten state. 9. The method according to claim 1, wherein the graft copolymer (B) when added to the vinyl copolymer (A) is made into a semi-molten or molten state. The thermoplastic resin composition according to the above. 10. A vinyl copolymer (A) is produced by subjecting a vinyl monomer mixture (a) to continuous bulk polymerization or continuous solution polymerization, followed by melting of the vinyl copolymer (A) The thermoplastic resin composition according to any one of claims 1 to 6, wherein the graft copolymer (B) is added to the mixture, and the mixture is melt-mixed. Production method.