JPH08113690A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE: To obtain a thermoplastic resin composition excellent in impact resistance, chemical resistance, stress cracking resistance, etc., by incorporating a specified amount of an acrylic graft copolymer mixture having a specified composition into a rubber-containing styrene resin. CONSTITUTION: A monomer mixture comprising 70-100wt.% (meth)acrylic ester of a 2-12C monohydric alcohol and 30-0wt.% copolymerizable other vinyl monomer is copolymerized with a polyfunctional vinyl monomer in such a manner that the gel of the produced acrylic rubbery polymer has a degree of swelling in methyl ethyl ketone at 25 deg.C of at least 30. In the presence of the obtained acrylic rubbery polymer latex, a vinyl monomer in an amount of 1-550 pts.wt. based on 100 pts.wt. solids of this latex is reacted by emulsion polymerization. 1-300 pts.wt. of the obtained acrylic graft copolymer mixture is then mixed with 100 pts.wt. rubber-containing styrene resin to produce the objective thermoplastic resin composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermoplastic resin composition. More specifically, it is composed of a rubber-containing styrene resin and a specific acrylic graft copolymer mixture, and has excellent properties in impact resistance, chemical resistance, low temperature stress cracking resistance, appearance and molding processability. And a thermoplastic resin composition which is useful not only for itself as an impact resistant material but also for blending this with other resins to produce an impact resistant resin composition.

[0002]

BACKGROUND OF THE INVENTION Rubber-containing styrenic resins are well known as impact-resistant resins, and a hard resin component is applied in the presence of a rubbery polymer (for example, a latex of a conjugated diene polymer). A resin composition produced by polymerizing a monomer (for example, styrene + acrylonitrile) to be used is widely used as an impact resistant resin. Of these, the graft copolymer composed of polybutadiene / styrene / acrylonitrile is well known as an ABS resin.

However, for example, ABS resin is inferior in properties such as chemical resistance, for example, when it is contacted with a specific chemical for a long time under a stress load, a crack is generated, and in a remarkable case, a phenomenon of breaking is observed. It was a thing. In order to obtain a resin excellent in these properties, a method of increasing the content ratio of the acrylonitrile component in the ABS resin (for example, JP-A-47-5594), ABS resin and acrylic rubber / styrene / acrylonitrile (ASA resin)
(JP-B-54-40258, JP-B-63-28460, JP-B-63-22222), and a method of mixing an acrylic acid ester-based polymer with an ABS resin (JP-B-63-22222). Gazette), a method of mixing two kinds of characteristic graft copolymers (Japanese Patent Publication No. 57-57
-22064, JP-A-2-175745)
Etc. have been proposed.

However, it can be said that these techniques are meaningful as a solution to the existing problems, but according to the experience of the present inventors,
Not completely satisfactory. That is, among the proposed methods, JP-A-47-5594 and JP-B-54
-40258, JP-B-63-22222,
In the resin based on the invention described in Japanese Examined Patent Publication No. 63-28460, etc., a defective phenomenon such as, for example,
Poor surface appearance called flow mark or surface peeling phenomenon may be observed, and surface appearance defect called die band may be observed in the surface condition of the extrusion molded product, which is a big problem in use. Was there. In addition, Japanese Examined Patent Publication No. 57-22064 or Japanese Unexamined Patent Publication No. 2-17574
The one proposed in Japanese Patent Publication No. 5 has insufficient chemical resistance, and in the field where more chemical resistance is required, it is still a problem in use.

[0005]

As described above, although the chemical resistance is improved by mixing the acrylic copolymer with the rubber-containing styrene-based resin, the appearance of the molded product is deteriorated by the mixing. Is. Therefore, various studies have been made on the structure and composition of the acrylic copolymer. For example, when the gel content is increased by copolymerizing with a polyfunctional vinyl monomer, the appearance is improved, but chemical resistance is improved. The sex was insufficient. Copolymerization of such a polyfunctional vinyl monomer generally lowers chemical resistance, so that a resin composition satisfying both chemical resistance and appearance has not yet been obtained. Is the current situation.

[0006]

[Means for Solving the Problems] As a result of earnest studies on these points, a special acrylic resin obtained by copolymerizing a polyfunctional vinyl monomer as an acrylic component and having a swelling degree of a gel of a specific value or more is obtained. In the presence of a rubber-based polymer latex, obtained by reacting a vinyl monomer at a specific ratio by an emulsion polymerization method, when a special acrylic graft copolymer is used, flow marks, die bands, gloss, Not only can the appearance such as yellowness and molding processability be improved, but, surprisingly, compared to the case where a polyfunctional vinyl monomer is not used, the same or higher chemical resistance without sacrificing physical properties, especially They have found that they exhibit excellent stress cracking resistance at low temperatures and have reached the present invention.

In order to solve the above problems, in the invention according to claim 1 of the present invention, in the presence of 100 parts by weight of the rubber-containing styrene resin (A) and the latex of the acrylic rubber polymer, From 1 to 550 parts by weight of the acrylic graft copolymer mixture (B) obtained by reacting 1 to 550 parts by weight of a vinyl monomer by emulsion polymerization with respect to 100 parts by weight of the solid content of this latex. In the thermoplastic resin composition, the acrylic rubber-like polymer in the acrylic graft copolymer mixture (B) is an ester compound of a monohydric alcohol having 2 to 12 carbon atoms and (meth) acrylic acid 70. To 100% by weight, and 0 to 30% by weight of another vinyl monomer copolymerizable therewith, a polyfunctional vinyl monomer is added to the monomer mixture.
A polymer obtained by copolymerizing the acrylic rubbery polymer so that the gel has a swelling degree of 30 or more in methyl ethyl ketone at a temperature of 25 ° C.,
Take the means.

[Detailed Description of the Invention] The present invention will be described in detail below. The thermoplastic resin composition according to the present invention is a mixture of the rubber-containing styrene resin (A) and a specific acrylic graft copolymer mixture (B) in a specific ratio.

[I] Rubber-containing styrenic resin (A) The rubber-containing styrene-based resin (A) in the present invention means a styrene-based monomer, a vinyl cyanide monomer, in the presence of a rubbery polymer. And / or a resin obtained by carrying out a graft polymerization reaction of a monomer mixture containing another vinyl monomer copolymerizable therewith.

(1) Rubber-like polymer The rubber-like polymer is intended to have a glass transition temperature lower than room temperature, and the monomers constituting the rubber-like polymer are butadiene, isoprene, dimethyl butadiene,
Conjugated diene monomers such as chloroprene and cyclopentene, non-conjugated diene monomers such as 2,5-norbornadiene, 1,4-cyclohexadiene and 4-ethylidene norbornene, styrene, α-methylstyrene, vinyltoluene, etc. Aromatic vinyl monomers, vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, (meth) acrylic acid ester monomers such as methyl methacrylate, ethyl acrylate and butyl acrylate, ethylene, propylene and 1-butene Examples thereof include olefin monomers, and these are used alone or in combination of two or more to obtain a rubbery polymer. The copolymer of two or more kinds of monomers may be either a random copolymer or a block copolymer. Further, the rubbery polymer may contain a small amount of a polyfunctional vinyl monomer as a crosslinking monomer.

Examples of polyfunctional vinyl monomers include divinylbenzene, ethylene glycol dimethacrylate, triallyl cyanurate, allyl acrylate, allyl methacrylate and glycidyl acrylate.
The method for polymerizing these monomers is not particularly limited, and known techniques such as emulsion polymerization method and solution polymerization method can be used. Further, the rubbery polymer does not have to be one kind, and may be a mixture of two or more kinds prepared separately.

(2) Monomer Mixture The monomer mixture used in the present invention for producing the rubber-containing styrene resin (A) is a styrene monomer, a vinyl cyanide monomer, and / or a mixture thereof. It is composed of another copolymerizable vinyl monomer. Examples of the styrene-based monomer include styrene and side-chain or / and nucleus-substituted styrene (substituents are a lower alkyl group, a lower alkoxy group, a trifluoromethyl group, a halogen atom, etc.), for example, α
-Methylstyrene, p-methylstyrene, o-methylstyrene, m-methylstyrene, nuclear halogenated styrene and the like. These may be used in combination within a group or between groups.

The vinyl cyanide monomer may, for example, be acrylonitrile, methacrylonitrile or α-chloroacrylonitrile. These may be used alone or as a mixture of two or more kinds. Further, a small amount of other vinyl monomer copolymerizable with the above-mentioned monomer may be used together as long as the gist of the present invention is not impaired. As such a vinyl monomer,
Examples thereof include esters of acrylic acid and methacrylic acid with monohydric alcohols having 1 to 10 carbon atoms, especially methyl methacrylate and the like.

(3) Graft Polymerization Reaction The rubber-containing styrene resin (A) is a rubbery polymer 100.
The total amount of the above monomer mixture is 45 to 7 parts by weight.
It is preferable that the compound is produced by allowing 100 parts by weight to be present and undergoing a graft polymerization reaction. When the amount of the monomer mixture is more than the above range, sufficient impact resistance is not expressed, and when the amount of the monomer mixture is less than the above range, the rigidity of the finally obtained resin composition is sufficient. It does not reach a satisfactory level, and neither is preferable.

The graft polymerization reaction is carried out by known methods such as bulk polymerization method, bulk-suspension polymerization method, solution polymerization method, emulsion polymerization method, emulsion-suspension polymerization method and emulsion-bulk polymerization method. An emulsion polymerization method in which a particle structure of a rubber-like polymer is prepared and polymerized in advance is generally used because the reaction can be easily controlled. The component (A) may be a mixture of a plurality of types of rubber-containing styrenic resins, in which case the conditions for the graft polymerization reaction of each resin do not have to be the same, and, for example, rubber obtained by bulk polymerization. It may be a mixture of the contained styrene resin and the rubber-containing styrene resin obtained by emulsion polymerization.

Obtained by graft polymerization reaction (A)
The components consist of a component ("branched" portion) in which the monomer mixture is grafted to the rubbery polymer, and a non-grafted hard resin component which is a continuous phase. The weight ratio of the "branching" monomer in the component (A) is 40 to 40% by weight of the styrene-based monomer.
80% by weight, vinyl cyanide monomer 20-60% by weight,
And other vinyl monomers copolymerizable with these 0 to 20
It is preferably in the weight%. If the amount of the vinyl cyanide monomer is more than the range of these weight ratios, the processability and the color tone are deteriorated, and if it is less, the chemical resistance is deteriorated, which is not preferable.

The graft polymerization reaction is preferably carried out in the presence of a polymerization initiator or a catalyst. Polymerization initiators that can be used include peracid catalysts such as persulfuric acid, peracetic acid and perphthalic acid, persalt catalysts such as potassium persulfate, hydrogen peroxide, benzoyl peroxide, chlorobenzoyl peroxide, naphthyl peroxide. , Acetyl peroxide, benzoyl acetyl peroxide, lauroyl peroxide and other peroxide catalysts, hydroperoxide t-butyl and other alkyl hydroperoxides, and azobisisobutyronitrile and other azo catalysts, all of which are independent. Alternatively, two or more kinds can be mixed and used. They can also be used as redox catalysts in combination with reducing agents.

The graft polymerization reaction can be carried out in the presence of a chain transfer agent. The chain transfer agent is not particularly limited, and examples thereof include n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, terpinolene, and α-methylstyrene linear dimer.
When the graft polymerization reaction is carried out by the emulsion polymerization method, the polymerization reaction temperature is preferably 50 to 85 ° C, preferably 55 to 75 ° C. When the temperature is lower than 50 ° C, the polymerization reaction rate is too slow to be practical, and when the temperature exceeds 85 ° C, the reaction occurs at once, and the solidified product is generated in the reaction product or the deposit on the reaction vessel (can). (Scale) is increased, and the polymerization rate and the quality of the final product are degraded, which is not preferable.

Other conditions for the graft polymerization reaction are ABS.
It is essentially the same as is commonly used in the manufacture of resins. The entire amount of the graft polymerization monomer may be introduced into the polymerization system at once, or may be introduced stepwise. Moreover, the polymerization initiator and the chain transfer agent may be introduced into the polymerization system all at once, or may be introduced stepwise. Further, the temperature of the polymerization system can be changed with time during the polymerization.

In order to adjust the content of the rubbery polymer contained in the component (A), it is possible to mix a resin component prepared separately as the component (A). The separately prepared resin component does not have to have the same composition as the resin component obtained by the graft polymerization reaction. The rubbery polymer in the component (A) has a weight average particle diameter of 0.10 to 0.65 μm.
It is preferably in the range of. If it is out of this range, the impact resistance of the finally obtained resin composition is poor and the molding processability is insufficient, which is not preferable.

The weight average particle diameter of the rubbery polymer does not need to be monomodal (1 peak distribution), but is multimodal (2 peaks distribution, 3 peaks).
Mountain distribution), that is, a mixture of plural kinds of rubbery polymers having different average particle diameters. When the rubbery polymer is produced by the emulsion polymerization method, the weight average particle diameter of the rubbery polymer emulsion, that is, the latex, can be easily measured by "N4" manufactured by Coulter, Inc., USA. Also,
When a rubbery polymer produced by a method other than the emulsion polymerization method is used, the weight average particle size of the rubbery polymer in the graft copolymer is an ultrathin cut from a test piece molded by an injection molding machine. The section of the layer can be observed and measured by an electron microscope.

[II] Acrylic graft copolymer mixture (B) (1) Acrylic rubbery polymer An acrylic rubbery polymer is a monohydric alcohol having 2 to 12 carbon atoms and (meth) acrylic acid. With ester compound 7
A polyfunctional vinyl monomer is added to a monomer mixture of 0 to 100% by weight and 0 to 30% by weight of another vinyl monomer copolymerizable therewith with the acrylic rubbery polymer. It is a polymer obtained by reaction by an emulsion polymerization method so that the degree of swelling of the gel in methyl ethyl ketone at a temperature of 25 ° C. is 30 or more.

Specific examples of the ester compound of a monohydric alcohol having 2 to 12 carbon atoms and acrylic acid in the present invention include ethyl acrylate, propyl acrylate,
Examples thereof include alkyl acrylates such as n-butyl acrylate, i-butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, and dodecyl acrylate. Particularly preferred is an ester compound of a monohydric alcohol having 4 to 8 carbon atoms and acrylic acid.

Specific examples of the ester compound with methacrylic acid include ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate and dodecyl methacrylate. Alkyl methacrylate of is mentioned. Particularly preferred is an ester compound of a monohydric alcohol having 4 to 8 carbon atoms and methacrylic acid. These ester compounds may be one kind or a mixture of two or more kinds.

Other vinyl monomers copolymerizable with the above ester compound include aromatic vinyl monomers, vinyl cyanide monomers, (meth) acrylic acid ester monomers, acrylic amides, and methacrylic acid. Examples thereof include roamide, vinylidene chloride, alkyl (about 1 to 6 carbon atoms) vinyl ether, and these may be one kind or a mixture of two or more kinds.

In producing the acrylic rubbery polymer,
A polyfunctional vinyl monomer is mixed with the above monomer mixture.
The polyfunctional vinyl monomer has a function of crosslinking an acrylic polymer and is a monomer having two or more vinyl groups in one molecule of the monomer. Specific examples of polyfunctional vinyl monomers include divinylbenzene, divinyltoluene, and other aromatic polyfunctional vinyl monomers, ethylene glycol dimethacrylate, nanoethylene glycol dimethacrylate, propylene glycol dimethacrylate,
Nano propylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, methacrylates and acrylates of polyhydric alcohols such as trimethylolpropane triacrylate, diallyl malate, diallyl fumarate, triallyl isocyanurate, allyl methacrylate, allyl acrylate, etc. These may be one kind or a mixture of two or more kinds.

In the acrylic rubbery polymer, the amount of the ester compound must be 70% by weight or more.
If it is less than 70% by weight, the chemical resistance of the thermoplastic resin composition obtained by mixing the components (A) and (B) is lowered, which is not preferable. The acrylic rubber polymer is produced by allowing an appropriate amount of a polyfunctional vinyl monomer to be present per 100 parts by weight of the above-mentioned monomer mixture and reacting it by an emulsion polymerization method.
An appropriate amount of the polyfunctional vinyl monomer needs to be such that the degree of swelling of the gel of the acrylic rubber polymer at a temperature of 25 ° C. when measured in methyl ethyl ketone is 30 or more. If the degree of swelling of the gel of the acrylic rubber polymer is less than 30, the chemical resistance of the resin composition obtained by mixing with the component (A) decreases, which is not preferable.

The degree of swelling of the acrylic rubbery polymer gel means that a 2% by weight solution of the rubbery polymer in methyl ethyl ketone is allowed to stand at a temperature of 25 ° C. for 48 hours and then filtered through a 100-mesh wire net to contain methyl ethyl ketone. The insoluble residue on the wire mesh {referred to as (A)} and the dried insoluble residue {referred to as (B)} are weighed, and the formula, {(A) /
(B)} is the value calculated by. If there are no insoluble residues, the degree of swelling of the gel is considered infinite.

The swelling degree of the gel of the acrylic rubbery polymer is controlled mainly by the amount of the polyfunctional vinyl monomer, but the kind and amount of the chain transfer agent, the initiator and the like, the polymerization temperature, etc. The degree of swelling of the gel can be adjusted within a preferable range by increasing the amount of the chain transfer agent and decreasing the polymerization temperature, for example. The acrylic rubber polymer is produced by an emulsion polymerization method.
These emulsion polymerization reactions are preferably carried out in the presence of a polymerization initiator, and as the polymerization initiator, those mentioned above can be used. The emulsion polymerization reaction can be carried out in the presence of the above-mentioned chain transfer agent. As the emulsifier, those usually used in the emulsion polymerization method can be used without limitation.

The latex rubber of the acrylic rubbery polymer preferably has a weight average particle diameter of 0.50 μm or less. When it exceeds 0.50 μm, the appearance of the molded article obtained from the resin composition is not excellent, which is not preferable. Particularly preferable in the above range is 0.05 to 0.4.
It is in the range of 0 μm. Acrylic polymer latex having a relatively large average particle diameter as described above can be directly obtained with a large particle diameter by selecting the production conditions.First, a polymer latex having a small particle diameter is produced, and then It can also be obtained via an operation of enlarging the particle size. The weight average particle size of the latex of the acrylic rubber polymer does not need to be monomodal (1 peak distribution), but is multimodal (2 peak distribution, 3 peaks).
Mountain distribution), that is, a mixture of plural kinds of latexes having different average particle diameters. The weight average particle size of the latex of the acrylic rubber polymer is measured by "N4" manufactured by Coulter, Inc. in the United States, as described above.

(2) Graft Polymerization As the vinyl monomer to be grafted on the acrylic rubbery polymer, the above-mentioned aromatic vinyl monomer, vinyl cyanide monomer, and / or other copolymerizable with these Is a monomer. Considering compatible mixing with the component (A),
The monomer used in the graft polymerization of [I] and its type,
It is desirable that the combination ratio be the same, but they may be different. Acrylic graft copolymer mixture (B)
In the presence of the acrylic rubbery polymer latex,
It is obtained by reacting one or more kinds of vinyl monomers in a specific amount by an emulsion polymerization method. Considering the compatibility with the component (A), the acrylic rubber-like polymer and the vinyl monomer that undergoes a polymerization reaction in the presence thereof preferably have a grafted structure, but need not have a grafted structure. .

The one or more vinyl monomers to be polymerized in the presence of the acrylic rubbery polymer latex are 1 to 550 with respect to 100 parts by weight of the acrylic rubbery polymer latex (based on solid content). The range is parts by weight. When the monomer mixture is less than this range, a molded article having a good appearance cannot be obtained from the resin composition, and when it is more than this range,
Sufficient chemical resistance cannot be obtained.

In the component (B), the weight ratio of the vinyl monomer polymerized in the presence of the acrylic polymer latex is
40 to 80% by weight of styrene-based monomer, 20 to 60% by weight of vinyl cyanide monomer, and 0 to 20% by weight of other vinyl monomer copolymerizable therewith are preferable. If the amount of the vinyl cyanide monomer is larger than these weight ratio ranges, the processability and color tone of the resin composition finally obtained will be deteriorated, and if it is smaller, the chemical resistance will be deteriorated, which is not preferable. These polymerization reactions are carried out in the presence of a polymerization initiator, and as the polymerization initiator, those mentioned above can be used. Also, it can be carried out in the presence of the above-mentioned chain transfer agent. Other emulsion polymerization reaction conditions are generally ABS, AA
It is essentially the same as that used in the production of S (acrylic rubber-acrylonitrile-styrene) and the like.

[III] Thermoplastic Resin Composition The thermoplastic resin composition according to the present invention contains 100 parts by weight of the rubber-containing styrene resin (A) component and the acrylic graft copolymer mixture (B) component. It is composed of 1 to 300 parts by weight. When the ratio of the component (B) is less than 1 part by weight, the chemical resistance of the thermoplastic resin composition obtained by mixing the component (A) and the component (B) is insufficient, and 300
If it exceeds the weight part, impact resistance, rigidity and workability deteriorate,
It is not preferable because the appearance of the molded product is deteriorated. To mix the components (A) and (B) and mix and knead them, a known mixing and kneading method may be used. At this time, the kneading temperature is preferably selected in the range where the resin composition does not cause resin burning.

Mixtures of two or three of these copolymers in the form of powder, beads, flakes or pellets are kneaded in a single screw extruder, a twin screw extruder, a Banbury mixer, a pressure kneader, a twin roll, etc. The desired thermoplastic resin composition can be prepared by a machine. Further, in some cases, a method of mixing two or three of these copolymers that have been polymerized, mixing them in an undried state, precipitating, washing, drying and kneading may be employed.

The thermoplastic resin composition according to the present invention contains a lubricant, a plasticizer, and a type and amount of a lubricant that does not impair the properties of the resin.
Antistatic agent, flame retardant, UV absorber, light resistance stabilizer,
Various resin additives such as heat resistance stabilizers and fillers can be appropriately combined and added. The thermoplastic resin composition according to the present invention may be injection-molded as it is, or may be diluted with an AS resin to reduce the content of rubbery polymer, or a composition obtained by mixing polyamide, polycarbonate and other engineering resins. Method, extrusion molding method, compression molding method, thermoforming method, etc.
It can be used as an application requiring excellent chemical resistance, workability and impact resistance, for example, as an electric part such as an inner box material of an electric refrigerator and an industrial part.

[0037]

EXAMPLES The following examples and comparative examples are intended to explain the present invention more specifically, and the present invention is not limited to the examples described below as long as the gist thereof is not exceeded. . In the following examples, "part" means "part by weight",
"%" Means% by weight. In each of the following examples and comparative examples, the physical properties of the thermoplastic resin were measured by the following methods.

(1) Weight average particle diameter of latex It was measured by "N4" manufactured by US Coulter Co. unit:
μm (2) Gel content rate A 2% by weight solution of an acrylic polymer in methyl ethyl ketone was allowed to stand at a temperature of 25 ° C. for 48 hours and then centrifuged in a centrifuge for 24 hours.
Separation at 00 rpm, removing the supernatant, drying the insoluble residue, {(insoluble residue) / (acrylic polymer)} × 100
A value calculated by (%). (3) Swelling degree of gel 2% by weight solution of the rubbery polymer in methyl ethyl ketone
After standing at a temperature of 5 ° C. for 48 hours, a 100-mesh wire net was filtered, and an insoluble residue on the wire net containing methyl ethyl ketone {this is referred to as (A)} and a dried insoluble residue {this is referred to as (B) } Is weighed and the value calculated by the formula {(A) / (B)} is used. (4) Tensile strength It was measured according to JIS K7113. Unit: Kg / cm
² (5) Izod impact strength Measured according to JIS K7110. Unit: Kg-cm /
cm (6) Flow mark Test piece (thickness 2.5mm, width 75mm,
A length of 160 mm) was prepared, and the presence or absence of flow marks on the surface of this test piece was visually observed. The judgment result is displayed as follows.

[0039]

[Table 1] A: No flow mark is observed. ◯: Almost no flow mark is recognized. Δ: Some flow marks are recognized. X: Flow marks are considerably recognized.

(7) Die line Sheet (thickness 2 mm, width 1100 mm) by extrusion molding method
Was extruded, and the presence or absence of a die line was visually observed on the surface of the sheet. The judgment result is displayed as follows.

[0041]

[Table 2] A: No die line is observed. ○: Almost no die line is recognized. Δ: Some die line is recognized. X: Die line is considerably recognized.

(8) Gloss Regarding the test piece used in the evaluation of the flow mark (4) above, a variable angle gloss meter (VGS-300A type) manufactured by Nippon Denshoku Industries Co., Ltd.
Was used, the gloss value was measured at 10 points, and the average value was calculated and displayed.

(9) Yellowness (YI) With respect to the test piece used in the above (4) Flow mark evaluation, a yellowness (YI) measuring instrument (S & S manufactured by Suga Test Instruments Co., Ltd.) was used.
M Color Computer Model SM-4).

(10) Chemical resistance A test piece manufactured by the compression molding method (thickness: 2 mm, width: 35 mm)
mm, length 230 mm) by a bending foam method at a temperature of 23 ° C. under an atmosphere of HCFC-141b.
Measure the critical strain value that cracks occurred when left for 7 hours,
The chemical resistance was judged. The judgment result was displayed as follows.

[0045]

[Table 3] A: The critical strain value exceeds 0.8%, and the chemical resistance is extremely good. ◯: The critical strain value is 0.8 to 0.6%, and the chemical resistance is good. Δ: The critical strain value is 0.6 to 0.4% and the chemical resistance is slightly poor. X: The critical strain value is less than 0.4% and the chemical resistance is poor.

(11) Strain causing low temperature whitening A dumbbell-shaped test piece having a length of 115 mm, a wide width portion of 30 mm, a narrow width portion of 10 mm, a thickness of 1 mm, and a narrow width portion of 50 mm was prepared by a compression molding method. . In the narrow part of this test piece,
A rigid polyurethane foam was adhered to the size of 10 mm in width, 10 mm in thickness and 50 mm in length by an in-situ foaming method using HCFC-141b as a foaming agent. This test piece was fixed to a jig with a tensile strain applied at a temperature of 23 ° C., cooled to −20 ° C. and maintained at this temperature for 17 hours,
The presence or absence of crazes or cracks was visually observed, and the maximum tensile strain at which crazes or cracks did not occur was measured. The smaller the value, the easier the low temperature whitening is, and the larger the value, the less the low temperature whitening is.

(12) Layered peelability By injection molding method, thickness 2 mm, width 50 mm, length 90 mm
Thus, a molded product having a gate at one end in the length direction of the molded product was prepared. The gate portion of the obtained molded product was folded by hand, and the state of the folded portion was visually observed to determine the layered peeling property. The judgment result was displayed as follows.

[0048]

[Table 4] ⊚: No peeling at all. ◯: Almost no peeling. Δ: A little peeled off. X: It peels considerably.

Method for Producing Rubber-Containing Styrenic Resin (A) A-1 (1) Production of Rubber Polymer 5 L capacity equipped with stirrer, heating / cooling device, condenser, thermometer, and raw material / auxiliary material charging device SUS autoclave, 150 parts deionized water, higher fatty acid soap (sodium salt of fatty acid containing 18 carbon as the main component)
4.0 parts and 0.075 parts of sodium hydroxide were charged, the atmosphere was replaced with nitrogen, and the temperature was raised to 68 ° C. 90 parts of 1,3-butadiene (hereinafter referred to as BD), styrene (hereinafter referred to as St) 10
And t-dodecyl mercaptan (hereinafter referred to as TDM)
After charging 20% of the monomer mixture consisting of 0.3 parts, 0.135 parts of potassium persulfate was added. After a few minutes, heat was generated and it was confirmed that the polymerization reaction had started. 80% of the monomer mixture was continuously charged from 1 hour after the addition of potassium persulfate, and the charging was completed at 6 hours. After the addition of the monomer mixture was completed, the internal temperature of the autoclave was raised to 80 ° C., and the reaction was further performed at this temperature for 1 hour. The obtained rubber-like polymer was in the form of latex and had a solid content of 39.
The content was 5%, the average particle size was 0.08 μm, and the gel content was 95.0%.

(2) Production of rubber-containing styrene resin In the reactor having a capacity of 5 L equipped with a stirrer, heating / cooling device, thermometer, and each raw material / auxiliary charging device, the above conjugated diene rubber latex (SBR) was added. 0.2 with acetic anhydride
The particle size was increased to 5 and 0.65 μm, 80 parts and 20 parts as solids, and 347 parts of deionized water (including water in latex) were charged, and the internal temperature was adjusted to 70.
The temperature was raised to ° C. At the time when the internal temperature reached 60 ° C during the heating, sodium pyrophosphate 1.0 dissolved in 20 parts of water was added.
Parts, dextrose 0.8 parts and ferrous sulfate 0.01
Parts were added. When the temperature reached 70 ° C, 70 parts of St, 30 parts of acrylonitrile (hereinafter referred to as AN), TDM1.
Monomer mixture consisting of 1 part, cumene hydroperoxide 0.5 part, disproportionated potassium rosinate soap 1.8
Parts, 0.37 parts of potassium hydroxide, and 35 parts of deionized water were each added over 2 hours and 30 minutes.
After the addition was completed, the reaction was continued for another 30 minutes to complete the reaction.

After adding 5 parts of an antioxidant to the graft copolymer latex, the latex was added to an aqueous magnesium sulfate solution heated to 95 ° C. with stirring to coagulate, and the coagulated product was washed with water and dried to give a white color. A powdery resin composition (A-1) was obtained.

A-2 (1) Production of rubbery polymer The same as in A-1 (1). (2) Production of rubber-containing styrene resin In the example described in A-1 (2), the rubber particle diameter is 0.2.
7 μm, dextrose addition amount 0.25 parts, St addition amount 60 parts, AN addition amount 40 parts, TDM addition amount 0.
A graft reaction and a post-treatment were carried out in the same procedure as in A-1 (2) except that the amount was changed to 2 parts to give a resin composition (A-
2) was obtained.

A-3 (1) Production of rubbery polymer Deionized in a glass flask having a capacity of 5 L equipped with a stirrer, a heating / cooling device, a condenser, a thermometer, each raw material / auxiliary charging device, etc. 151 parts of water, 2 parts of higher fatty acid soap (sodium salt of fatty acid mainly having 18 carbon atoms),
1 part of sodium hydrogen carbonate was charged and the temperature was raised to 75 ° C. under a nitrogen stream. After adding 0.135 parts of potassium persulfate,
Over 5 minutes, 4 parts of a monomer mixture consisting of 95 parts of acrylic acid butyl ester (hereinafter referred to as BA) and 5 parts of AN, and 0.5 part of methacrylic acid allyl ester (hereinafter referred to as AMA) was charged. After a few minutes, heat was generated and it was confirmed that the polymerization reaction had started. From the 20th minute after charging the monomer mixture, the continuous addition of the remaining monomer mixture to the flask was started, and the addition was completed 3 hours and 20 minutes after the continuous addition was started. During this time, 1 part of fatty acid soap was added at 2 hours, and 0.015 potassium persulfate was added at 2 hours and 30 minutes.
Parts were added. After the continuous addition of the monomer mixture, the internal temperature is set to 80 ° C
The temperature was raised to and the reaction was carried out at this temperature for another hour. The obtained rubbery polymer had a solid content concentration of 39.5% and an average particle size of 0.08 μm.

(2) Production of rubber-containing styrene resin In the reactor used in A-1 (2), the latex of the above rubber-like polymer (hereinafter referred to as AR) was added to acetic anhydride to give an amount of 0.1.
100 parts as a solid content of which particle size is enlarged to 15 μm,
1 part of sodium hydrogen carbonate and 274 parts of deionized water (including the water content of the latex) were charged, and the temperature was raised to 80 ° C. When the internal temperature reached 70 ° C. during the temperature rise, AMA0.
5 parts were added. When the temperature reached 80 ° C, St 70 parts,
A monomer mixture consisting of 30 parts of AN and 0.2 part of TDM, and an aqueous solution consisting of 0.5 part of potassium persulfate, 1.8 parts of disproportionated potassium rosinate soap, and 45 parts of deionized water were each added for 3 hours and 30 minutes. It was added over. After the addition was completed, the reaction was continued for another 30 minutes and cooled to complete the reaction.

After adding 5 parts of an antioxidant to the graft copolymer latex, the latex was added to an aqueous magnesium sulfate solution heated to 95 ° C. with stirring to coagulate, and the coagulated product was washed with water and dried. A white powdery resin composition (A-3) was obtained.

A-4 St 394 parts, EPDM (Mooney viscosity ML1 + 4 (in Mooney viscosity ML1 + 4 ( 100 ° C.) 45, iodine value 25, ethylidene norbornene as the third component) 100 parts, and n
-Heptane (71 parts) was charged, the atmosphere in the autoclave was replaced with nitrogen, and the mixture was stirred at a temperature of 50 ° C and a strength of 100 rpm for 2 hours to completely dissolve the rubber component in the solvent. Then, with stirring, 184 parts of AN was charged at a rate of 3 parts / minute, and
0.357 part of er-butyl peroxide, 0.093 part of di-ter-butyl peracetate, and 0.357 part of terpinolene were charged and reacted at 97 ° C. for 7 hours and 20 minutes by a bulk polymerization method.

About 30 minutes before the reaction by the bulk polymerization method was completed, a solution consisting of 1.07 parts of di-ter-butyl peroxide, 0.357 parts of terpinolene and 36 parts of St was charged into the autoclave. The average particle size of EPDM contained in the reaction mixture after completion of the bulk polymerization reaction was 1.6 μm. An aqueous solution prepared by dissolving 1.8 parts of the suspending agent in 790 parts of water was added to an autoclave having a capacity of 3 L equipped with three retreating blades, a heating / cooling device, a condenser, a thermometer, and each raw material / auxiliary charging device. After charging with the syrup obtained in the bulk polymerization step and replacing the inside of the autoclave with nitrogen,
The reaction was carried out by a suspension polymerization method at 500 ° C. for 2 hours, then the internal temperature was raised to 150 ° C. and stripping was carried out for 1 hour to recover the unreacted monomer and the solvent.
The obtained resin composition was washed with water and dried at 100 ° C. to obtain 920
g of a bead-shaped resin composition (A-4) was obtained. The results of the production of the rubber-containing styrene resin (A) are summarized in Table 1.

[0058]

[Table 5]

Acrylic graft copolymer mixture (B)
Manufacturing method of acrylic polymer B1 B1-1 151 parts of deionized water in a glass flask having a capacity of 5 L equipped with a stirrer, a heating / cooling device, a condancer, a thermometer, a raw material / auxiliary charging device, etc. , 2 parts of higher fatty acid soap (sodium salt of fatty acid mainly having 18 carbon atoms),
1 part of sodium hydrogen carbonate was charged, and the internal temperature was raised to 75 ° C. while stirring under a nitrogen stream. After adding 0.135 parts of potassium persulfate to the flask and 5 minutes later, 4 out of a monomer mixture consisting of 100 parts of BA and 0.5 part of ethylene glycol dimethacrylate (EGDM) was added.
The department was set up.

After a few minutes, heat was generated and it was confirmed that the polymerization reaction had started. At 20 minutes after charging the monomer mixture, continuous charging of the remaining monomer mixture into the flask was started, and the continuous charging was completed over 3 hours. In the middle of the 2nd hour, 1 part of fatty acid soap was charged and 2 hours and 30 minutes
At the minute, 0.015 part of potassium persulfate was additionally charged. After the continuous charging of the monomer mixture was completed, the internal temperature was raised to 80 ° C., and the reaction was continued at the same temperature for 1 hour. Regarding the obtained acrylic rubber polymer latex (B1-1), the solid content concentration is 39.5%, and the average particle size is 0.08 μm.
m, the gel content was 88%, and the gel swelling degree was 50.

B1-2 In the example described in B1-1, the composition of the monomer mixture is B
A 95 parts, methacrylic acid methyl ester (MMA) 5
Polymerization reaction was carried out by the same procedure as in the same example except that the parts and EGDM were changed to 0.05. About the obtained acrylic rubbery polymer latex (B1-2),
The solid content concentration was 39.1%, the average particle size was 0.08 μm, the gel content was 40%, and the gel swelling degree was 60.

B1-3 In the example described in B1-1, the composition of the monomer mixture is B
A polymerization reaction was carried out by the same procedure as in the example except that the amount of A was changed to 100 parts, EGDM to 1.0 part, and TDM to 0.2 part. Regarding the obtained acrylic rubbery polymer latex (B1-3), the solid content concentration was 39.3%, the average particle size was 0.08 μm, the gel content rate was 75%, and the gel swelling degree was 40. .

B1-4 In the example described in B1-1, the composition of the monomer mixture is B
A polymerization reaction was carried out by the same procedure as in the same example except that 100 parts of A and 10 parts of EGDM were changed. Regarding the obtained acrylic rubbery polymer latex (B1-4), the solid content concentration was 39.7%, the average particle size was 0.08 μm, the gel content rate was 92.0%, and the gel swelling degree was 23. there were.

B1-5 In the example described in B1-1, the composition of the monomer mixture is B
A polymerization reaction was carried out by the same procedure as in the same example except that the content was changed to 100 parts of A and 0.8 parts of nanoethylene glycol methacrylate (9EGDM). Regarding the obtained acrylic rubbery polymer latex (B1-5), the solid content concentration was 39.1%, the average particle size was 0.08 μm, the gel content rate was 56%, and the gel swelling degree was 61. .

B1-6 In the example described in B1-1, the composition of the monomer mixture is B
A polymerization reaction was performed by the same procedure as in the same example except that the amount of A was changed to 100 parts and the EGDM was changed to 1.5 parts. Regarding the obtained acrylic rubbery polymer latex (B1-6),
The solid content concentration was 39.3%, the average particle size was 0.08 μm, the gel content was 90%, and the gel swelling degree was 37.

B1-7 In the example described in B1-1, the composition of the monomer mixture is B
A polymerization reaction was carried out by the same procedure as in the same example except that the content was changed to 100 parts of A and 0.8 parts of nano-propylene glycol dimethacrylate (9PEGDM). Regarding the obtained acrylic rubbery polymer latex (B1-7), the solid content concentration was 39.2%, the average particle size was 0.08 μm, the gel content rate was 66%, and the gel swelling degree was 60. .

B1-8 In the example described in B1-1, the composition of the monomer mixture is B
Polymerization reaction was carried out by the same procedure as in the same example except that the amount of A was changed to 100 parts and 9PGDM to 1.5 parts. Regarding the obtained acrylic rubbery polymer latex (B1-8), the solid content concentration is 39.4%, and the average particle size is 0.08 μm.
m, the gel content was 98%, and the gel swelling degree was 35.

B1-9 In the example described in B1-1, the composition of the monomer mixture is B
A polymerization reaction was carried out in the same procedure as in the same example except that 100 parts of A and 0.4 parts of 1,6-hexanediol dimethacrylate (HDDM) were changed. Regarding the obtained acrylic rubbery polymer latex (B1-9), the solid content concentration was 39.4%, the average particle size was 0.08 μm, the gel content rate was 44%, and the gel swelling degree was 41. .

B1-10 In the example described in B1-1, the composition of the monomer mixture is B
A polymerization reaction was carried out by the same procedure as in the same example except that the amount of A was changed to 100 parts and the amount of HDDM was changed to 1.0 part. Regarding the obtained acrylic rubber polymer latex (B1-10), the solid content concentration is 39.1%, and the average particle size is 0.08 μm.
m, the gel content was 83%, and the gel swelling degree was 34.

B1-11 In the example described in B1-1, the composition of the monomer mixture is B
A 100 parts, allyl methacrylate (AMA) 0.01
Polymerization reaction was carried out by the same procedure as in the same example except that parts were changed. The resulting acrylic rubber polymer latex (B1-11) has a solid content concentration of 39.0%,
The average particle size was 0.09 μm, the gel content was 39%, and the gel swelling degree was 44.

B1-12 In the example described in B1-1, the composition of the monomer mixture is B
Polymerization reaction was carried out by the same procedure as in the same example except that A100 and AMA were changed to 0.5 part. Regarding the obtained acrylic rubbery polymer latex (B1-12),
The solid content concentration was 39.0%, the average particle size was 0.09 μm, the gel content was 97%, and the gel swelling degree was 13.

B1-13 In the example described in B1-1, the composition of the monomer mixture is B
The polymerization reaction was carried out by the same procedure as in the same example except that 100 parts of A and the polyfunctional vinyl monomer were not used. The obtained acrylic rubbery polymer latex (B1-1
Regarding 3), the solid content concentration was 39.5%, the average particle diameter was 0.08 μm, the gel content was 1.4%, and the gel swelling degree was infinite (∞). Acrylic rubbery polymer B1-1
Table 2 collectively shows production examples of B1 to B1-13.

[0073]

[Table 6]

Acrylic graft copolymer mixture (B)
B-1: Acrylic polymer latex B1-1 as solid content in a glass flask having a capacity of 5 L equipped with a stirrer, a heating / cooling device, a condancer, a thermometer, each raw material, and an auxiliary charging device. Charge 100 parts, sodium pyrophosphate 1.0 part, glucose 0.25 part, ferrous sulfate 0.01 part, and deionized water 258 parts (including latex water),
The internal temperature was raised to 70 ° C. while stirring under a nitrogen stream.
When the internal temperature reached 70 ° C, St154 parts, AN66
Parts, and a monomer mixture containing 0.2 parts of TDM, and an aqueous solution of 1.8 parts of disproportionated potassium rosinate soap and 0.5 parts of cumene hydroperoxide in 48 parts of deionized water. Continuous charging was started, and both were finished over 3 hours and 30 minutes. After the continuous charging was completed, the reaction was continued at the same temperature for another 30 minutes and then cooled to complete the reaction. After adding 2.5 parts of anti-aging agent to the obtained graft copolymer latex, this latex was added to an aqueous magnesium sulfate solution heated to 95 ° C with stirring to coagulate, and the coagulated product was washed with water and dried. To obtain a white powdery resin composition (B-1).

B-2 to B-13 The same example as in B-1 except that the acrylic polymer latex was replaced by B-2 to B-13 as shown in Table 3. Polymerization reaction was carried out by the same procedure as in (1) to obtain a resin composition. The obtained white powdery resin compositions are designated as B-2 to B-13.

B-14 In the example described in B-1, the acrylic polymer latex is B1-3, and the monomer mixture to be reacted therewith is a mixture of St 70 parts, AN 30 parts and TDM 0.2 part. Polymerization reaction was carried out by the same procedure as in the example except that the above was changed to a white powdery resin composition (B-14).

B-15 In the example described in B-1, the acrylic polymer latex is B1-3, and the monomer mixture to be reacted therewith is a mixture of St280 parts, AN120 parts and TDM0.2 parts. Except that the polymerization reaction was carried out in the same procedure as in the example except that the white powdery resin composition (B-1
5) was obtained.

B-16 In the example described in B-1, the acrylic polymer latex is B1-3, and the monomer mixture to be reacted therewith is a mixture of St420 parts, AN180 parts, and TDM0.2 parts. Except that the polymerization reaction was carried out in the same procedure as in the example except that the white powdery resin composition (B-1
6) was obtained. Acrylic graft copolymer mixture (B)
The details of the manufacturing method of are shown in Table 3 collectively.

[0079]

[Table 7]

Examples 1 to 13 The above rubber-containing styrene resin (A), acrylic graft copolymer mixture (B) and AS resin for dilution (SAN-L manufactured by Mitsubishi Chemical Co., Ltd.) are shown in Tables 4 to 4. Weigh it in the ratio shown in Table-5, and add magnesium stearate 0.4
Parts, 0.2 parts of a finned phenolic stabilizer, and 4.0 parts of titanium oxide were weighed and mixed, mixed with a blender, kneaded with a Banbury mixer, and pelletized. Using these pellets, a test piece for physical properties measurement and CFC resistance measurement is molded by injection molding, and physical properties are measured, appearance (flow mark, die band, gloss), yellowness, chemical resistance, low-temperature whitening strain. The values and the results of evaluating the layered releasability are shown in Tables 4 to 5.

Comparative Examples 1 to 6 The rubber-containing styrene resin (A), the acrylic graft copolymer mixture (B), and the diluent AS resin were mixed in the proportions shown in Table 6, and kneaded with a Banbury mixer, Pelletized. Test pieces were prepared from the pellets by an injection molding method, and various evaluation tests were performed in the same manner as in the examples. The results are shown in Table-6.

[0082]

[Table 8]

[0083]

[Table 9]

[0084]

[Table 10]

The following is clear from Tables 4 to 6. (1) The thermoplastic resin composition according to the present invention is not only capable of producing flow marks and die bands, but also has a good gloss and a small yellowness, so that a molded article having an excellent appearance is obtained, and also the chemical resistance is high. And the physical properties such as tensile strength and impact resistance are not deteriorated (Examples 1 to 13). (2) On the other hand, when the acrylic graft copolymer (B) is not contained (Comparative Example 1 and Comparative Example 2), the chemical resistance and the stress cracking resistance at low temperature are poor,
When the acrylic graft copolymer does not contain a polyfunctional vinyl monomer (Comparative Example 5), the appearance of the molded product (including flow marks, die bands, gloss, yellowness, etc.) and delamination are poor. Further, the gel swelling degree of the acrylic rubbery polymer in the acrylic graft copolymer (B) is 30.
If it is less than (Comparative Example 3 and Comparative Example 4), the appearance of the molded product is excellent, but the stress cracking resistance (low temperature whitening occurrence strain) at low temperature and the chemical resistance are poor. (3) Further, the acrylic graft copolymer mixture (B)
During production, when the amount of vinyl monomer to be grafted to the acrylic copolymer is large, the thermoplastic resin composition finally obtained has a molded article appearance such as flow mark, die band, gloss, and yellowness, Stress cracking resistance at low temperature, chemical resistance, delamination resistance, etc. are not balanced (Comparative Example 6).

[0086]

INDUSTRIAL APPLICABILITY The present invention has the following special advantageous effects and its industrial utility value is extremely large. 1. The thermoplastic resin composition according to the present invention does not cause delamination when molded, is excellent in chemical resistance, resistance to stress cracking at low temperatures, and is suitable for use in manufacturing inner boxes of electric refrigerators and other industrial materials. Is. 2. A molded article obtained from the thermoplastic resin composition according to the present invention is excellent in appearance such as flow marks, die bands, good gloss, and low yellowness, and does not deteriorate in physical properties such as tensile strength and impact resistance.

Claims (1)

[Claims] 1. In the presence of 100 parts by weight of a rubber-containing styrene resin (A) and a latex of an acrylic rubber polymer, 1 to 100 parts by weight of the solid content of this latex is used.
In a thermoplastic resin composition comprising 1 to 300 parts by weight of an acrylic graft copolymer mixture (B) obtained by reacting 550 parts by weight of a vinyl monomer by an emulsion polymerization method, an acrylic graft copolymer The acrylic rubbery polymer in the combined mixture (B) has 2 to 12 carbon atoms.
More than a monomer mixture consisting of 70 to 100 wt% of an ester compound of monohydric alcohol and (meth) acrylic acid, and 0 to 30 wt% of other vinyl monomer copolymerizable with them. It is a polymer obtained by copolymerizing a functional vinyl monomer so that the degree of swelling of the gel of this acrylic rubber polymer in methyl ethyl ketone at a temperature of 25 ° C. is 30 or more. , A thermoplastic resin composition.