JPH1072512A - Rubber-modified copolymer resin composition and its preparation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rubber-modified copolymer resin composition improved in transparency, weathering resistance, practical strengths, impact resistance and oil resistance by grafting a styrene monomer and an alkyl (meth) acrylate onto a specified copolymer rubber. SOLUTION: A mixture comprising a copolymer rubber having a 5wt.% styrene solution viscosity of 5-40cP, a mean particle diameter of 0.40-0.80μm, a Mooney viscosity of 20-80 and a styrene skeleton content of 1-20wt.% and a mixture of 5-40wt.% styrene monomer with 95-60wt.% (meth) acrylic ester is fed through a plunger pump 1 into an agitation reactor 2 and subjected to preliminary grafting to a conversion of 10-28wt.%. The product is fed into tubular reactors 4-6 each provided with a static mixing element though a gear pump 3, and subjected to initial grafting to a conversion of 35-55wt.%. The product of initial grafting is fed into tubular reactors 8-10 each having a static mixing element and subjected to grafting at 140-160 deg.C to a conversion of 60-85wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved rubber-modified copolymer resin composition and a method for producing the same, and more particularly, to a styrene monomer and a (meth) acrylic compound in the presence of a styrene-butadiene copolymer rubber. Transparency, weather resistance, and practical strength obtained by graft copolymerization with an alkyl acid, especially excellent when used as injection molded products or extruded products, especially excellent impact resistance of molded products, and weather resistance and oil resistance The present invention relates to a rubber-modified copolymer resin composition having excellent properties and a production method thereof.

[0002]

2. Description of the Related Art MS resin, which is a styrene-methyl methacrylate copolymer, is transparent and has excellent strength, and is used as a molding material for applications such as lighting and projection television displays. However, MS resins generally have a drawback that impact strength is weak and their applications are limited. Therefore, as resins having improved MS resin impact strength, for example, Japanese Patent Publication No. 5-54484, JP-A-6-16744 discloses a rubber-modified styrene resin obtained by dissolving a rubbery polymer in a monomer and then performing graft polymerization on a transparent and impact-resistant styrene resin.
An alkyl (meth) acrylate copolymer resin and a continuous bulk polymerization method are disclosed.

As a method for producing a resin having both impact resistance and weather resistance, Japanese Patent Application Laid-Open No. 55-147514 discloses a rubbery polymer and a monomer containing methyl methacrylate as an essential component. Are continuously bulk-polymerized to obtain a syrup having a polymerization conversion of 5 to 40% by weight, and further completed by a casting method or a suspension polymerization method.

[0004]

However, the above-mentioned Japanese Patent Publication No.
In the rubber-modified styrene-alkyl (meth) acrylate copolymer resin described in JP-A-54484 and JP-A-6-16744, the weather resistance is inferior similarly to that of rubber-modified polystyrene, and the weather resistance for outdoor use and the like is low. At present, it is not suitable for required applications in terms of performance.

On the other hand, among those disclosed in JP-A-55-147514, a resin using polybutadiene rubber as a rubbery polymer and using methyl methacrylate and styrene in combination as monomer components is disclosed. Although the weather resistance is excellent, the impact resistance is not yet sufficient. In addition, in the bulk-suspension polymerization method, since the conversion of the monomer is advanced to 98% or more and completed, the composition distribution occurs in the matrix resin formed at the beginning and end of the polymerization, and the transparency of the molded article is significantly lost. was there. Further, even if the amount of rubber is increased to improve the impact resistance of such a resin, the transparency is further deteriorated.

Further, in this method, although the process for producing the syrup is continuous, a rubber solution feed is used in the same manner as in the method for producing the rubber-modified polystyrene and the rubber-modified styrene-alkyl (meth) acrylate copolymer resin. It is not applicable to a continuous continuous bulk polymerization method that is consistent from graft polymerization to removal of monomers and pelletization. That is, the production method of Japanese Patent Application Laid-Open No. 55-147514, including the batch method, has limitations in terms of productivity and reduction of production cost, and does not increase the rubber content in the product due to restrictions on viscosity during prepolymerization. Also, because the rubber particle size cannot be reduced,
A rubber-modified graft copolymer having extremely excellent impact strength could not be produced.

Accordingly, an object of the present invention is to provide a rubber-modified copolymer resin composition having remarkably excellent weather resistance, impact resistance and transparency, and a continuous bulk polymerization method for producing the same. It is in.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of such circumstances, and have found that a copolymer rubber of a styrene monomer and a diene monomer, a styrene monomer (b) and a (meth) acrylic resin. Transparent rubber modification excellent in weather resistance and impact resistance by graft-polymerizing a specific copolymer rubber (a) with a specific range of a copolymer monomer composition in a graft copolymer with an alkyl acid (c). A styrene-alkyl (meth) acrylate copolymer resin composition was obtained, and it was found that the above problems could be solved. Thus, the present invention was completed.

That is, according to the present invention, a graft copolymer rubber particle obtained by graft-polymerizing a styrenic monomer and an alkyl (meth) acrylate onto a rubbery polymer is a copolymer of a styrene-based monomer and an alkyl (meth) acrylate. In a rubber-modified copolymer resin composition in which the coalesce is dispersed as a matrix resin, the graft copolymer rubber resin particles are a copolymer of a styrene monomer and a diene monomer, and
A graft copolymer of a copolymer rubber (a) having a styrene skeleton content of 1 to 20% by weight, a styrene monomer (b) and an alkyl (meth) acrylate (c), and a matrix resin comprising: A rubber-modified copolymer resin composition comprising a copolymer of 5 to 40% by weight of the styrene-based monomer (b) and 60 to 95% by weight of the alkyl (meth) acrylate (c); A copolymer of a styrene monomer and a diene monomer, and a copolymer rubber (a) having a styrene skeleton content of 1 to 20% by weight;
The styrene monomer (b) and the alkyl (meth) acrylate (c) are converted into a styrene monomer (b) / (meth)
Weight ratio of alkyl acrylate (c) (5 to 40) / (9
The present invention relates to a method for producing a rubber-modified copolymer resin composition, wherein graft copolymerization is carried out by using a ratio of 5 to 60).

As described above, the rubber-modified copolymer resin composition of the present invention comprises graft copolymer rubber particles and a matrix resin. The graft copolymer rubber particles are a copolymer rubber (a) of a styrene monomer and a diene monomer.
And a graft copolymer containing a styrene monomer (b) and an alkyl (meth) acrylate (c) as essential components. In the present invention, the styrene skeleton content in the copolymer rubber (a) Is important to be 1 to 20% by weight.

That is, when the styrene skeleton content in the copolymer rubber (a) is less than 1% by weight, only a molded article having inferior transparency can be obtained.
, The impact resistance is lowered without increasing the content. on the other hand,
If it exceeds 20% by weight, the weather resistance will be significantly reduced. According to common sense, it is considered that the lower the polybutadiene content is, the lower the double bond content is, so that the weather resistance is improved, but in the present invention, the range where the polybutadiene content is relatively high is surprisingly surprising. That is, the weather resistance is improved in the low range of 1 to 20% by weight in terms of the styrene skeleton content. In addition, it is particularly preferable that the styrene skeleton content is 3 to 15% by weight from the viewpoint of excellent balance of these properties.

The copolymer rubber (a) constituting the graft copolymer resin particles may be a copolymer of a styrene-based monomer and a diene-based monomer, and may be either a block copolymer or a random copolymer. In particular, when a random copolymer is used, the weather resistance of the composition of the present invention is extremely excellent.

On the other hand, the matrix resin in the present invention is a copolymer of 5 to 40% by weight of the styrene monomer (b) and 60 to 95% by weight of the alkyl (meth) acrylate (c). When the content of the system monomer (b) is less than 5% by weight, transparency is remarkably lost, and application of a continuous polymerization method using a tubular reactor described later becomes difficult. If the content of the styrene monomer (b) exceeds 40% by weight, excellent weather resistance is not exhibited. In the present invention, the content of the styrene monomer (b) is in the range of 20 to 35% by weight,
The content of the alkyl (meth) acrylate (c) is 65 to 8
The range of 0% by weight is particularly preferable in terms of transparency, fluidity, and oil resistance.

The (meth) acrylate (b) constituting the matrix resin is preferably a combination of methyl methacrylate and another alkyl acrylate in view of the fluidity and transparency of the composition. In particular, n-butyl acrylate is preferably used as the other alkyl acrylate ester since it has no odor, has a low boiling point, and is easily deaerated in the purification step.

The rubber-modified copolymer resin composition of the present invention preferably has a toluene-insoluble content at 25 ° C. of 10 to 25% by weight. Within this range, the impact resistance becomes remarkably good. In the present invention, even if the impact resistance is improved, the transparency does not decrease.

Further, the rubber-modified copolymer resin composition of the present invention satisfies the above-mentioned toluene-insoluble content, has a swelling index of 6 to 15 with toluene, and has a toluene-insoluble content / swelling index of 0. It is preferably 80 to 2.50% by weight. In this range, the rubber-modified copolymer resin has a good balance between the degree of grafting and the degree of cross-linking of the copolymer rubber in the resin, and balances the transparency, impact resistance and weather resistance of the molded article. Is remarkably good.

The shape of the graft copolymer resin particles dispersed in the matrix resin is not particularly limited, but a so-called “salami structure” in which the matrix resin is occluded and dispersed in the graft copolymer rubber particles. Is preferred from the viewpoint of impact resistance. Also,
The average particle diameter of the graft copolymer resin particles is not particularly limited, but the average rubber particle diameter is 0.20 to 1.2.
It is preferably 0 μm, and in particular, from the viewpoint of excellent transparency, impact resistance and gloss of the rubber-modified copolymer resin composition.
It is particularly preferable that the thickness be 40 to 0.80 μm. In the present invention, the content of toluene insoluble matter at 25 ° C. is 1
Even at a high level of 0 to 25% by weight, the average particle size can be reduced in this way, and as a result, the effects of transparency and impact resistance are more excellent than ever before.

The weight average molecular weight (Mw) of the copolymer of the matrix resin (a), (b) and (c) is 50,000 to 180,000, and the weight average molecular weight (Mw) and the number average molecular weight (Mw) (Mn) having a ratio Mw / Mn of from 1.8 to 3.0 is preferred, and especially those having a weight-average molecular weight (Mw) of from 80,000 to 150,000 have improved impact resistance and resin fluidity and are excellent in transparency. Particularly preferred from the point of view.

In the present invention, by using isoparaffinic petroleum hydrocarbons in addition to the matrix resin and the graft copolymer resin, plasticity can be imparted and oil resistance can be further improved. Examples of the isoparaffinic petroleum hydrocarbons include, for example, isobutene,
It is a polymer or a modified product of a raw material component mainly composed of an isoolefin represented by isopentene, isohexene, isoheptene, isooctene and the like, and has a structure mainly having a structure having an isoalkylene unit as a repeating unit. Or a maleic acid-modified product or a phosphorus pentasulfide-modified product having a structure having an isoalkylene unit as a repeating unit.

Among these isoolefins, isobutene is particularly preferred from the viewpoint of the effect of improving oil resistance and the effect of plasticization. The monomer component containing isobutene as a main component also contains monomers such as 1-butene and 2-butene in addition to isobutene, and is a liquid viscous liquid obtained by polymerizing these.

In order to obtain a modified isoolefin polymer, the isoolefin is polymerized with an unsaturated bond-containing monomer such as maleic acid or phosphorus pentasulfide, or after the isoolefin is polymerized. The unsaturated bond monomer present in the polymer may be reacted with the unsaturated bond monomer.
Further, the obtained isoparaffinic petroleum hydrocarbon may be one in which unsaturated bonds in the molecule are hydrogenated.

These isoparaffinic petroleum hydrocarbons are not particularly limited in molecular weight and the like, but usually have a viscosity of 20 to 10,000 by a BM type viscometer.
0 cps (38 ° C.), especially 5 cps.
The range of 0 to 3,000 cps is excellent in mixing dispersibility when mixed with the matrix resin, or excellent in compatibility with each of the components (a) to (c), and further from the viewpoint of transparency and surface appearance of the molded product. Is also preferred. For the same reason, the average molecular weight is 20.
It is preferably from 0 to 3,000.

The content of isoparaffinic petroleum hydrocarbons is not particularly limited, but is preferably in the range of 0.1 to 10% by weight in the composition from the viewpoint of plasticizing effect and oil resistance. .

The method for producing the rubber-modified copolymer resin composition of the present invention is not particularly limited, but is preferably produced by the production method of the present invention described in detail below.

That is, a copolymer rubber (a) having a styrene skeleton content of 1 to 20% by weight, which is a copolymer of a styrene monomer and a diene monomer, a styrene monomer (b), Graft copolymerization using alkyl (meth) acrylate (c) at a weight ratio of styrene monomer (b) / alkyl (c) methacrylate (5-40) / (95-60) This method is preferable because the continuous bulk polymerization method can be easily performed.

In the production method of the present invention, the styrene monomer (b) and the alkyl (meth) acrylate (c)
And the weight ratio of styrene monomer (b) / alkyl (meth) acrylate (c) (5 to 40) / (95 to 60)
It is important to use them in such a ratio.

The use ratio of the styrene monomer (b) is 5
When the amount is less than the weight percentage, transparency is remarkably lost, and application of a continuous polymerization method using a tubular reactor becomes difficult. In addition, the use ratio of the styrene monomer (b) is 40
If the amount is more than 10% by weight, excellent weather resistance is not exhibited. In the present invention, the styrene monomer (b)
Is preferably 20 to 40% by weight, particularly from the viewpoint of transparency and fluidity.

The styrene monomer constituting the copolymer rubber (a) of a styrene monomer and a diene monomer used herein includes, for example, styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, Methyl styrene, ethyl styrene, isobutyl styrene,
Tertiary butyl styrene, o-bromostyrene, m
-Bromostyrene, p-bromostyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene and the like.

On the other hand, examples of the diene monomer constituting the copolymer rubber include butadiene, chloroprene, isoprene, 1,3-pentadiene and the like. As the copolymer rubber (a), various ones obtained by combining and reacting these monomers are exemplified, and among them, styrene-butadiene copolymer rubber is particularly preferred from the viewpoint of excellent mutual reactivity of the two components.

As described above, the content of the styrene skeleton in the copolymer rubber (a) is preferably 1 to 20% by weight from the viewpoint of weather resistance. Furthermore, the styrene skeleton content is 3
It is particularly preferred that the amount is from 15 to 15% by weight.

The bonding between the styrene monomer and the diene monomer in the copolymer rubber (a) may be random bonding, block bonding, or tapered block bonding. This is preferable because the effect of improving the weather resistance becomes remarkable. That is, as the bound styrene content of the copolymer rubber increases to 20% by weight, it is important to reduce the blocking ratio of the bound styrene in order to improve the weather resistance of the rubber-modified copolymer resin composition resin. More specifically, when the styrene skeleton content of the copolymer rubber is from 10 to 20% by weight, the use of a copolymer rubber having a completely random bond or a large number of random bond portions is much more effective in improving weather resistance. Becomes

The copolymer rubber (a) used in the production method of the present invention has a 5% by weight styrene solution viscosity of 5 to 40 centipoise. This is preferable because the diameter can be easily controlled. As described above, the average particle diameter of the graft copolymer resin particles is good in transparency, impact resistance and gloss in the range of 0.40 to 0.80 μm.
When the copolymer rubber (a) having a 5% by weight styrene solution viscosity of 28 to 35 centipoise at 5 ° C. is used to obtain graft copolymer resin particles having the above particle diameter range, the weather resistance is improved in addition to these properties. It can be dramatically improved. The copolymer rubber (a) preferably has a Mooney viscosity of 20 to 80 at 100 ° C. using an L rotor.

The copolymer rubber (a) preferably has a 1,2-vinyl bond ratio of 7 to 35% of the unsaturated bonds based on the diene monomer, and more preferably 14 to 25%. In this case, the remainder of the 1,2-vinyl bond forms a cis and trans bond.

Here, the ratio of 1,2-vinyl bonds is 7%
When the above copolymer rubber is used, the content of toluene-insoluble components in the rubber-modified copolymer resin increases, and the impact resistance is improved. On the other hand, when the proportion of the 1,2-vinyl bond is 25% or less, the progress of crosslinking at a high temperature during production can be suppressed, while the grafting ratio can be increased, the rubber elasticity can be improved, and the impact resistance can be improved. The performance is improved. Further, when it falls within the range of 14 to 25%, the balance between the degree of grafting of the graft copolymerized rubber particles and the degree of crosslinking is significantly improved, and the rubber elasticity is significantly improved, which is preferable.

Further, the copolymer rubber (a) may be a rubber partially hydrogenated with an aliphatic double bond based on a diene monomer. The hydrogenation rate is not particularly limited, but is preferably 45% or less, especially 30% or less, because the grafting rate is improved and the impact resistance is good.

Styrene monomer (b) used in the present invention
As styrene, α-methylstyrene, o-
Methyl styrene, m-methyl styrene, p-methyl styrene, ethyl styrene, isobutyl styrene, tertiary butyl styrene, o-bromostyrene, m-bromostyrene, p-bromostyrene, o-chlorostyrene,
Examples thereof include m-chlorostyrene and p-chlorostyrene, and among them, styrene is preferred from the viewpoint of excellent transparency.

The alkyl (meth) acrylate (c) used in the present invention includes alkyl esters such as methyl (meth) acrylate, ethyl (meth) acrylate and propyl (meth) acrylate. Although it is an essential component for imparting transparency and strength to the rubber-modified copolymer resin composition of the present invention, methyl methacrylate is particularly preferred.

Further, an alkyl (meth) acrylate (c)
It is preferable from the viewpoint of fluidity and transparency to use methyl methacrylate in combination with other alkyl acrylates.As the alkyl acrylate to be used, for example, ethyl acrylate, propyl acrylate,
Examples thereof include n-butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate. Above all, n-butyl acrylate is preferred because it has a boiling point close to that of a styrene monomer or a solvent and is used in terms of vacuum removal of unreacted monomer, condensation and recycling in the devolatilization step. Also,
The use ratio of other alkyl acrylates is not particularly limited, but may be used in a range where other (meth) acrylic acid alkyl esters are 2 to 20% by weight of all (meth) acrylic acid alkyl esters. preferable.

The proportion of the copolymer rubber (a), the styrene monomer (b) and the alkyl (meth) acrylate (C) is not particularly limited, but is usually (a) /
A range in which the weight ratio of [(b) + (c)] is 3/97 to 16/84 is preferable in that a material having excellent transparency and impact resistance can be obtained. The weight ratio of (a) / [(b) + (c)] is preferably 5/95 to 12/88 from the viewpoint of further improving transparency and impact strength.

In the production method of the present invention, a styrene monomer (b) and an alkyl (meth) acrylate (c) are used as essential components in the presence of the copolymer rubber (a),
Further, if necessary, graft copolymerization may be carried out by bulk-suspension polymerization, solution polymerization or bulk polymerization together with other copolymerizable monomers. Among them, continuous bulk polymerization is preferred in terms of productivity and cost.

Other copolymerizable monomers used herein include, for example, vinyl / cyan compounds such as (meth) acrylonitrile; and polymerizable unsaturated fatty acids such as itaconic acid, maleic acid, fumaric acid, crotonic acid, and cinnamic acid. N-
Such as methylmaleimide, N-ethylmaleimide, N-butylmaleimide, N-octylmaleimide, N-isopropylmaleimide, N-phenylmaleimide, Np-bromophenylmaleimide, No-chlorophenylmaleimide, and N-cyclohexylmaleimide. Maleimides; unsaturated carboxylic anhydrides represented by maleic anhydride, itaconic anhydride, citraconic anhydride, etc .; containing amino groups such as allylamine, aminoethyl (meth) acrylate, and aminopropyl (meth) acrylate. Unsaturated compounds; acrylamide compounds such as acrylamide and N-methylacrylamide;

The reactor used for the continuous bulk polymerization is not particularly limited, but a tubular reactor (hereinafter, referred to as a tubular reactor) having a plurality of mixing elements having no moving parts fixed therein.
It is preferably a continuous bulk polymerization line incorporating "tubular reactors with static mixing elements").

As a polymerization method using the bulk polymerization line, for example, the tubular polymerization is performed in a continuous bulk polymerization line incorporating one or more agitated reactors and a tubular reactor having a static mixing element. The method of performing bulk polymerization continuously while performing static mixing with a reactor has a small rubber particle diameter, can uniformly control the polymer composition,
This is preferable in that a rubber-modified copolymer resin having excellent transparency and impact resistance can be efficiently produced.

As such a method, specifically, for example, a polymerization line connected to a continuous bulk polymerization line in which two stirred reactors are connected and then a tubular reactor having a static mixing element is incorporated is used. (A)
Each component of (c) and, if necessary, other copolymerizable monomers are introduced into a stirred reactor, and polymerization is performed in a second stirred reactor to a polymerization rate of 40 to 60%. Although the method of introducing into a continuous bulk polymerization line can be mentioned, the following continuous bulk polymerization method is excellent in productivity, and also can use a large amount of rubber of the obtained composition and further improve the impact resistance. Is preferred.

That is, a mixed solution containing a copolymer rubber (a), a styrene-based monomer (b), and an alkyl (meth) acrylate (c) was mixed with: a. A stirred reactor; An initial polymerization line consisting of one or more tubular reactors having fixed therein a plurality of mixing elements continuing from the reactor and having no moving parts; c. A plurality of mixing elements continuing from the initial polymerization line and having no moving parts. A main polymerization line consisting of one or more tubular reactors, and a reflux line branched between the initial polymerization line and the main polymerization line to return into the initial polymerization line. A continuous bulk, in which a part of the initial polymerization liquid stream exiting from the initial polymerization line is refluxed through the reflux line while the initial polymerization liquid stream that has not been refluxed is polymerized in the main polymerization line. Polymerization is preferred.

An example of the continuous bulk polymerization method will be described below with reference to the drawings. FIG. 1 is a process diagram showing an example of a continuous bulk polymerization line incorporating a tubular reactor having a static mixing element.

(A) supplied by a plunger pump (1) constituting a raw material supply line (I),
The mixed solution containing (b) and (c) as essential components is first sent to a pre-polymerization line (II) (stirred reactor (2)), and subjected to pre-graft polymerization under stirring, and then to a gear pump (3). ) To an initial polymerization line (III) having tubular reactors (4), (5) and (6) with static mixing elements.

The pre-graft polymerization in the pre-polymerization line (II) (stirred reactor (2)) and the initial polymerization line (II)
By combining with (I), the rubber particles are not excessively sheared, so that the rubber particles can be more efficiently miniaturized, and the polymer composition in the polymerization step can be made uniform. In the preliminary graft polymerization in this case, the total polymerization conversion rate of the styrene monomer (b) and the alkyl (meth) acrylate (c) is as follows:
The reaction is carried out at the outlet of the reactor (2) at 10 to 28% by weight, preferably 14 to 24% by weight. Further, as the stirred reactor (2), for example, a stirred tank reactor,
Stirred tower reactors and the like can be mentioned. Examples of the stirring blades include anchor type, turbine type, screw type and double helical type stirring blades.

In the present invention, a solvent may be used to reduce the viscosity of the mixed solution in the reactor, and the amount of the solvent used is 5 to 20 parts by weight based on 100 parts by weight of the raw material monomers in total. . As the type of the solvent, toluene, ethylbenzene, xylene and the like which are usually used in the bulk polymerization method are suitable.

In the present invention, it is preferable to add a chain transfer agent to the above-mentioned mixed solution in order to control the molecular weight of the rubber-modified copolymer resin. The amount of the chain transfer agent to be added is usually 0.05 to 0.5 based on 100 parts by weight of the total of the raw material monomers.
It is in the range of parts by weight.

The mixed solution preliminarily graft-polymerized under dynamic stirring as described above is then polymerized in the initial polymerization line (III). A part of the initial polymerization liquid flowing out of the initial polymerization line (III) is introduced into the reflux line (V) and is returned to the initial polymerization line (III) again by the gear pump (7), and the graft polymerization is performed by this circulation. On the other hand, among the initial polymerization liquids flowing out of the initial polymerization line (III), the non-refluxed initial polymerization liquids are continuously fed into the tubular reactors (8), (9) and (1) each having a static mixing element.
0) is sent to the main polymerization line (IV) incorporated in series.

The rubber particles in the mixed solution in the initial polymerization line (III) are statically mixed while circulating in a circulation line composed of the initial polymerization line (III) and the reflux line (V). It stabilizes and the particle size is fixed. In this case, the reflux ratio (R) of the mixed solution in the circulation line and the total polymerization conversion rate of (b) and (c) are important factors. The reflux ratio R is defined as F1 (liter / hour) where the flow rate of the mixed solution flowing into the reflux line (V) without flowing out to the main polymerization line (IV) is F1 (liter / hour). ), The flow rate of the mixed solution F2 (liter / hour) is usually R = F1 / F2.
In particular, the pressure loss in the tubular reactor is small, the resulting rubbery polymer particles are stable, the particle size can be reduced, and the styrene-based monomer in the rubber-modified copolymer resin ( R = 5 in that the content ratio of b) to the alkyl (meth) acrylate (c) can be kept constant.
A range of from 10 to 10 is particularly preferred.

Further, the graft polymerization in the initial polymerization line (III) is carried out by using (b) at the outlet of the initial polymerization line (III).
And (c) are polymerized so that the total polymerization conversion is usually 35 to 55% by weight, preferably 40 to 50% by weight. A suitable polymerization temperature is 120 to 135 ° C.

The mixed solution graft-polymerized in the initial polymerization line (III) is then supplied to the main polymerization line (IV), and the styrene monomer (b) and the (meth) acrylic acid are usually added at a polymerization temperature of 140 to 160 ° C. Graft polymerization is continued until the total conversion of the alkyl (c) becomes 60 to 85% by weight. Next, this mixed solution was applied to the Kear pump (1).
After being sent to a preheater and then to a devolatilization tank according to 1), the unreacted monomer and the solvent are removed under reduced pressure, and then pelletized, an intended rubber-modified copolymer resin is obtained. At this time, it is preferable to perform the preheating and the devolatilization under the condition that the increase in the conversion rate in the preheater and the devolatilization tank is 7% by weight or less.

As the plurality of mixing elements fixed inside the tubular reactor having the static mixing element used in the present invention, for example, the flow of the polymerization solution flowing into the pipe is changed and the flow direction is changed, Is repeated to mix the polymerization liquid. As such a tubular reactor, for example, SMX type, SMR
Sulzer-type tubular mixers, Kenix-type static mixers, and Toray-type tubular mixers are preferred.

The initial polymerization line (III) and the main polymerization line (I
The number of these tubular reactors incorporated in V) is not particularly limited in the case of the tubular reactor as described above, because it differs depending on the length, the structure of the mixing element, etc., but the tubular reactor having four or more mixing elements 4 ~
Fifteen, preferably six to ten are used in combination. Among them, the number of the tubular reactors to be incorporated in the initial polymerization line (III) is usually 1 to 10, preferably 2 to 6.

The mixed solution used as a raw material in the present invention includes:
It is preferable to add an organic peroxide that releases free radicals when decomposed as a polymerization initiator, if necessary, since kraft formation and the reaction can be promoted at a relatively low temperature. The addition amount is in the range of 0.005 to 0.04 parts by weight based on 100 parts by weight of the total amount of the raw material monomers.

The organic peroxide used here is preferably one having a temperature at which the half life is 10 hours of 75 to 170 ° C., and specific examples thereof include 1,1-di-t-butylperoxycyclohexane, 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-tert-butylperoxy-2-methylcyclohexane, 2,2-bis (4,4-di ゛-Tert-butylperoxycyclohexyl) propane, 2,2-di-tert-butylperoxyoctane, n-
Butyl-4,4-di-t-butyl peroxyvalerate, 2,
Peroxy ketals such as 2-di-t-butyl peroxybutane; t-butyl peroxy acetate, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxy laurate, t -Butylperoxybenzoate, t-butylperoxymethatoruate, di-t
-Butyldiperoxyisophthalate, 2,5-dimethyl-
2,5-dibenzoylperoxyhexane, t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, di-t-butyl peroxide, sicumyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide And the like, and used alone or in combination of two or more.

The mixed solution used in the present invention may further contain a plasticizer such as mineral oil, an antioxidant,
Known additives such as a chain transfer agent, a releasing agent such as a long-chain fatty acid, its ester or its metal salt, and silicone oil may be used in combination. In addition, dimethylsiloxane or methylphenylsiloxane is particularly preferable as the silicone oil, and the amount used in this case is preferably 0.05 to 0.5% by weight from the viewpoint of impact resistance.

When isoparaffinic petroleum hydrocarbons are used in combination in the composition of the present invention, the mixing method is not particularly limited. For example, in the case of graft copolymerization in a continuous bulk polymerization line described in detail. Method 1: Graft copolymerization while mixing isoparaffinic petroleum hydrocarbons in the middle of the continuous bulk polymerization line, or Method 2: In a mixed solution of (a), (b) and (c), Dissolving the isoparaffinic petroleum hydrocarbons and then performing the graft copolymerization, or Method 3: performing the graft copolymerization to obtain a composition of the graft copolymerized rubber particles and the matrix resin, It is preferable to carry out the method by any one of the above-mentioned methods 1 to 3 in which the mixture is melt-kneaded with an isoparaffinic petroleum hydrocarbon.

The thus obtained rubber-modified copolymer resin composition of the present invention may further contain a conventionally used antioxidant, plasticizer, ultraviolet absorber, lubricant, flame retardant, antistatic agent, foaming agent, reinforcing material Etc. can be blended.

As specific examples, for example, mineral oil,
Ester plasticizers, polyester plasticizers, organic polysiloxanes, higher fatty acids and metal salts thereof, hindered phenolic antioxidants, glass fibers, etc., can be used alone or in combination. In particular, specific examples of additives usually used for improving weather resistance include:
Benzotriazole-based or benzophenone-based ultraviolet absorbers represented by Tinuvin P, Tinuvin 327 (Japan Ciba Geigy Co., Ltd.), etc .; Phenolic antioxidants, hindered amine light stabilizers represented by SANOL LS-770, phosphorus antioxidants represented by trisnonylphenyl phosphite, and organic sulfur represented by dimyristylthiodipropionate And antioxidants.

The rubber-modified copolymer resin composition of the present invention may further comprise a polystyrene resin, a rubber-modified polystyrene resin, an AS resin, an ABS resin, a styrene-methyl methacrylate copolymer resin, a rubber-modified styrene-methacrylic acid, if necessary. Methyl copolymer resin, (meth) acrylic resin, styrene-maleic anhydride copolymer resin, styrene- (meth) acrylic acid copolymer resin, polycarbonate resin, vinyl chloride resin, and ethylene such as EEA and EMA -(Meta)
A thermoplastic resin such as acrylic acrylate may be added as appropriate.

The use of the rubber-modified copolymer resin composition of the present invention is not particularly limited, but is particularly useful in sheet extrusion, unstretched film extrusion, or shrink film extrusion.

The method for producing the sheet or film is not particularly limited, and the above-mentioned components are mixed, melt-extruded in advance by a method such as dry blending or pre-mixing, and continuously extruded from a T-die, a circular die or the like. And a method in which the extrusion is directly performed from the hot parison or cooled and adjusted to a temperature suitable for stretching, and the film is stretched at a high stretching ratio, for example, 2 to 5 times, and is stretched uniaxially or biaxially to an area stretching ratio. When the block copolymer (C) is used in combination, it is preferable to mix the component (C) during melt-kneading at the time of forming a sheet or a film. Alternatively, the melt-extruded raw material may be cooled once and then stretched by reheating again to an area ratio of 3 to 15 times.
The thickness of the sheet or film is not particularly limited and is usually 0.01 to 10.0 mm, but the preferable range in which the effect of improving the impact strength is remarkably exhibited varies depending on the particle diameter of the graft copolymer rubber particles. However, when the particle size is 0.05 to 0.80 μm, the thickness of the sheet or film is preferably 0.02 to 5.0 mm.

The rubber-modified copolymer resin composition of the present invention may be prepared by injection molding, single-screw extrusion, twin-screw extrusion, inflation extrusion, profile extrusion, vacuum molding, in addition to the above-mentioned sheets and films. Various molded articles can be used by molding methods such as pressure molding, blow molding and the like. Its applications are wide-ranging and include, for example, lighting, signboards, displays, electrical components, weak electrical components, and building materials such as carport sunroofs. More specifically, it can be used as various parts of OA equipment such as a copying machine, a printer, a facsimile, a personal computer, etc., and a part of medical instruments.

[0067]

The present invention will be described more specifically below with reference to examples and comparative examples. However, all parts in the examples are parts by weight, and all percentages are percentages by weight except for the total light transmittance.

The methods for measuring the average particle diameter of the graft copolymer resin particles, the toluene insoluble content, the swelling index with toluene, the Izod impact value, the total light transmittance and the haze value are described below.

1. Average particle size of graft copolymer resin particles in resin Take transmission electron micrograph by ultra-thin section method of resin,
The particle diameter of 1000 particles in the photograph was measured, and the average particle diameter was determined by the following equation.

[0070]

(Equation 1) (However, ni is the number of rubber particles having a particle diameter Di.) The rubber particle distribution was also observed using a laser type particle size distribution analyzer LA-910 (manufactured by HORIBA, Ltd.).

2. Toluene insoluble content and swelling index due to toluene 1 g of the rubber-modified copolymer resin was precisely weighed, and 100 ml of toluene was added.
The solution was transferred to a centrifuge tube at 25 ° C. for 24 hours, centrifuged at 8500 rpm at 10 ° C. or less for 15 minutes, and the supernatant was removed by decantation. Weigh the minute. Next, it is dried for 24 hours in a vacuum dryer at 60 ° C., the weight of the obtained toluene-insoluble component is measured, and the content of the toluene-insoluble component is calculated by the following equation.

[0072]

(Equation 2) The swelling index is calculated by the following equation.

[0073]

(Equation 3)

3. Izod impact value Compliant with JIS K-6871. 4. Total light transmittance and haze A test piece having a thickness of 2 mm was prepared by an injection molding method, and the value was determined in accordance with ASTM D-1003.

5. Exposure to weather resistance The test piece for impact strength was exposed to a weather meter (WEL-SUN-DCH-B, manufactured by Suga Test Instruments), and after 500 hours, the test piece was taken out and the impact strength was measured. Calculated.

[0076]

(Equation 4)

6. Oil resistance test of molded article A dumbbell test piece having a length of 165 mm is fixed in an arc shape to a test jig having a length of 160 mm to give a distortion. Oil was applied to the surface of the test piece and left at 23 ° C. and 50% humidity.

After a certain period of time, the appearance of the molded article was observed and the retention was measured. In this test, salad oil (edible soybean oil) and kerosene were used.

Example 1 In this example, devices arranged as shown in FIG. 1 were used. A mixed solution containing styrene, methyl methacrylate, butyl acrylate, a rubbery polymer, and a solvent is sent to a 20-liter stirred reactor (2) by a plunger pump (1), and subjected to dynamic mixing by a stirring blade. Initial graft polymerization. Next, this mixed solution is sent to the initial polymerization line (I) by the gear pump (3). The initial polymerization line (I) is a tubular reactor having an inner diameter of 2.5 inches (30 SMX static mixers and 30 static mixing elements manufactured by Gebrüder Sulzer, Switzerland) in order from the inlet (4), (5) and (6) And a gear pump (7) for circulating the mixed solution. Reflux line (V) with tubular reactor (6) and gear pump (7)
And an outlet connected to the main polymerization line (V). The same tubular reactors (8), (9) and (10) as above and a gear pump (11) are connected in series from the inlet to the main polymerization line (V).

Styrene-butadiene random copolymer rubber [5% styrene solution viscosity at 25 ° C. (hereinafter 5% SV
Abbreviated): 32 centipoise, styrene / butadiene weight ratio: 5/95] A mixed solution comprising 7 parts, styrene 25 parts, methyl methacrylate 70 parts, butyl acrylate 5 parts and ethylbenzene 10 parts was prepared, and a chain transfer agent was prepared. 0.2 part of n-dodecylmercaptan and 100 parts of monomer mixture as monomer mixture
0.015 parts of 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane was added to 00 parts, and bulk polymerization was continuously performed using the above apparatus under the following conditions. .

Continuous supply amount of mixed solution: 10 liter / hour Reflux ratio R: 7 Reaction temperature in stirred reactor (2): 115 ° C. Reaction temperature in initial polymerization line (III): 130 ° C. Main polymerization Reaction temperature in line (IV): 140-160 ° C. The mixed solution obtained by polymerization is heated to 235 ° C. with a heat exchanger, volatile components are removed under a reduced pressure of 50 mmHg, and the mixture is pelletized. Was obtained. From the electron micrograph of the obtained rubber-modified copolymer resin composition, Table 1 shows analytical data and measurement results of physical properties of the graft copolymer rubber in the matrix resin having a salami structure.

Example 2 Styrene-butadiene random copolymer rubber [5% SV:
25 centipoise, styrene / butadiene weight ratio: 10/9
0] 8 parts, styrene 30 parts, methyl methacrylate 65
Parts, butyl acrylate and 10 parts of ethylbenzene were used in the same manner as in Example 1 to obtain a rubber-modified copolymer resin composition of the present invention. Table 1 shows the analytical data and the measurement results of the physical properties.

Example 3 Styrene-butadiene block copolymer rubber [5% SV:
25 centipoise, styrene / butadiene weight ratio: 10/9
0] 8 parts, styrene 30 parts, methyl methacrylate 65
Parts, butyl acrylate and 10 parts of ethylbenzene were used in the same manner as in Example 1 to obtain a rubber-modified copolymer resin composition of the present invention. Table 1 shows the analytical data and the measurement results of the physical properties.

Example 4 Amoco polybutene "Amoco polybutene L-65 (viscosity: 120 cps)" was used as an isoparaffinic petroleum hydrocarbon in 100 parts of the rubber-modified copolymer resin composition obtained in Example 1. Two parts were mixed and pelletized using a twin screw extruder to obtain a rubber-modified copolymer resin composition of the present invention. Table 1 shows the analytical data and the measurement results of the physical properties.

Comparative Example 1 Styrene-butadiene block copolymer rubber [5% SV:
10 centipoise, styrene / butadiene weight ratio: 35/6
5] 10 parts, styrene 46 parts, methyl methacrylate 54
And a mixed solution consisting of 10 parts of ethylbenzene and 100 parts of the monomer mixture as a chain transfer agent.
0.1 part of n-dodecyl mercaptan and 0.02 part of t-organic per 100 parts of monomer mixture as organic peroxide
Example 1 except that butyl peroxybenzoate was added
In the same manner as in the above, bulk polymerization was carried out to obtain a rubber-modified copolymer resin composition.

Comparative Example 2 7 parts of polybutadiene (5% SV: 25 centipoise)
A mixed solution comprising 30 parts of styrene, 65 parts of methyl methacrylate, 5 parts of butyl acrylate and 10 parts of ethylbenzene was prepared, and 0.2 part of n-dodecyl mercaptan and 0.2 part of n-dodecyl mercaptan were used as a chain transfer agent per 100 parts of the monomer mixture. 0.01 as an organic peroxide with respect to 100 parts of the monomer mixture.
Except that 5 parts of 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane was added, continuous bulk polymerization was carried out in the same manner as in Example 1 to obtain a rubber-modified copolymer resin composition. Was.

Comparative Example 3 Partially hydrogenated polybutadiene (TP-083, manufactured by Asahi Kasei Corporation)
5% SV: 85 centipoise, hydrogenation ratio 20%) A mixed solution consisting of 7 parts of styrene, 30 parts of styrene, 65 parts of methyl methacrylate, 5 parts of butyl acrylate and 10 parts of ethylbenzene was prepared. 0.1 part of n-dodecyl mercaptan per 100 parts of the mixture and 0.01 as monomeric mixture per 100 parts of the monomer mixture.
Except that 5 parts of 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane was added, continuous bulk polymerization was carried out in the same manner as in Example 1 to obtain a rubber-modified copolymer resin composition. Was.

[0088]

[Table 1] Table 1

：: Retention rate of 80% or more Δ: Retention rate of 50%
×: broken

[0090]

[Table 2] Table 2

：: retention rate of 80% or more Δ: retention rate of 50%
×: broken

[0092]

According to the present invention, there can be provided a rubber-modified copolymer resin composition which is excellent in weatherability, impact resistance and transparency of a molded article. Further, in the present invention, not only these effects, but also the oil resistance of the molded product is remarkably excellent.

Further, when continuous bulk polymerization is performed, the productivity is remarkably improved. The rubber-modified copolymer resin composition obtained by the production method of the present invention is excellent in practical strength of transparency, impact resistance and weather resistance, and thus can be suitably used for various molded articles.

[Brief description of the drawings]

FIG. 1 is a process diagram showing an example of a continuous polymerization line incorporating a tubular reactor having a static mixing element therein. (1): Plunger pump (2): Stirred reactor (3): Gear pump (4): Static mixing element (5): Tubular reactor having a static mixing element inside (6): Static mixing Tubular reactor with elements inside (7): gear pump (8): Tubular reactor with static mixing elements inside (9): Tubular reactor with static mixing elements inside (10): Static mixing Tubular reactor having an element inside (11): gear pump (I): raw material supply line (II): prepolymerization line (III): initial polymerization line (IV): main polymerization line (V): reflux line

Claims (16)

[Claims] 1. A graft copolymer rubber particle obtained by graft-polymerizing a styrenic monomer and an alkyl (meth) acrylate onto a rubbery polymer, the styrene-based monomer and (meth)
In a rubber-modified copolymer resin composition in which a copolymer with an alkyl acrylate is dispersed as a matrix resin, the graft copolymer rubber particles are a copolymer of a styrene monomer and a diene monomer, and contain a styrene skeleton. Is a graft copolymer of a copolymer rubber (a) having a ratio of 1 to 20% by weight, a styrene-based monomer (b) and an alkyl (meth) acrylate (c), and the matrix resin is a styrene-based monomer. 5 of (b)
40% by weight and 60 of alkyl (meth) acrylate (c)
A rubber-modified copolymer resin composition characterized by being a copolymer with about 95% by weight. 2. The composition according to claim 1, wherein the resin composition has a toluene insoluble content at 25 ° C. of 10 to 25% by weight. 3. A toluene insoluble content at 25 ° C. of 10
２５25% by weight, swelling index by toluene is 6-15,
And the toluene insoluble content / swelling index is 0.80-2.
The composition according to claim 2, which is 50% by weight. 4. The composition according to claim 1, wherein the graft copolymer rubber particles have a salami structure and have an average particle size of 0.2 to 1.2 μm. 5. Graft copolymer rubber particles are obtained by graft copolymerizing a random copolymer rubber (a) of a styrene monomer and a diene monomer with a styrene monomer (b) and an alkyl (meth) acrylate (c). The composition according to claim 1, 2, 3 or 4, wherein the composition is prepared. 6. The composition according to claim 1, wherein the matrix resin is a combination of methyl methacrylate and another alkyl acrylate as the alkyl (meth) acrylate. . 7. The composition according to claim 1, further comprising isoparaffinic petroleum hydrocarbons in addition to the matrix resin and the graft copolymerized rubber particles. 8. A copolymer of a styrene-based monomer and a diene-based monomer and having a styrene skeleton content of 1 to 8.
20% by weight of a copolymer rubber (a), a styrene monomer (b), and an alkyl (meth) acrylate (c) are mixed with a weight of a styrene monomer (b) / alkyl (meth) acrylate (c). A method for producing a rubber-modified copolymer resin composition, wherein graft copolymerization is performed using a ratio of (5 to 40) / (95 to 60). 9. A styrenic monomer (b) and (meth)
The use ratio with the alkyl acrylate (c) is a ratio such that the weight ratio of the styrene monomer (b) / (meth) alkyl acrylate (c) is (20 to 35) / (80 to 65). 8. The production method according to 8. 10. The method according to claim 8, wherein the copolymer rubber (a) of a styrene monomer and a diene monomer is a random copolymer of a styrene monomer and a diene monomer. 11. The method according to claim 8, wherein the copolymer rubber (a) has a 5% by weight styrene solution viscosity at 25 ° C. of 5 to 40 cps. 12. The method of claim 8, 9, 10 or 1, wherein methyl (meth) acrylate (c) is used in combination with methyl methacrylate and another alkyl acrylate.
2. The production method according to 1. 13. A tubular reaction comprising a copolymer rubber (a), a styrenic monomer (b) and an alkyl (meth) acrylate (c) in which a plurality of mixing elements having no movable parts are fixed. The process according to any one of claims 8 to 12, wherein the graft copolymerization is carried out in a continuous bulk polymerization line incorporating a vessel. 14. A copolymer rubber (a), a styrenic monomer (b), and an alkyl (meth) acrylate (c) are mixed with one or more stirred reactors and a plurality of stirred reactors having no movable parts. The process according to any one of claims 8 to 13, wherein the graft copolymerization is carried out in a continuous bulk polymerization line incorporating a tubular reactor having a mixing element fixed therein. 15. A mixed solution containing a copolymer rubber (a), a styrenic monomer (b), and an alkyl (meth) acrylate (c), comprising: a. A stirring reactor; An initial polymerization line consisting of one or more tubular reactors having fixed therein a plurality of mixing elements continuing from the reactor and having no moving parts; c. A plurality of mixing elements continuing from the initial polymerization line and having no moving parts. A main polymerization line consisting of one or more tubular reactors, and a reflux line branched between the initial polymerization line and the main polymerization line to return into the initial polymerization line. Using a polymerization line, a part of the initial polymerization liquid stream exiting the initial polymerization line is refluxed via a reflux line, while the non-refluxed initial polymerization liquid stream is polymerized in the main polymerization line. The method according 14. 16. A method for graft copolymerization in a continuous bulk polymerization line, comprising:
Graft copolymerization is carried out while mixing isoparaffinic petroleum hydrocarbons (B). Method 2: Isoparaffinic petroleum hydrocarbons (B) are mixed in a mixed solution of (a), (b) and (c). Dissolving and then performing the graft copolymerization, or Method 3: performing the graft copolymerization to obtain the graft copolymer (A), and then melt-kneading with the isoparaffinic petroleum hydrocarbons (B). Item 16. The method according to Item 13, 14, or 15.