JPH0867789A - Thermoplastic resin composition and its production - Google Patents

Abstract

PURPOSE: To obtain a thermoplastic resin compsn. which is excellent in thermal stability, does not stain a mold in its injection molding, and hardly emits an odor or a gas during its molding. CONSTITUTION: This resin compsn. is a melt mixture comprising 10-90 pts.wt. styrenic resin obtd. by the polymn. in the presence of an emulsifier and 90-10 pts.wt. resin component comprising an arom. polycarbonate resin and/or an arom. polyester resin, contains a residual coagulated emulsifier in an amt. of 1.2wt.% or lower of the resin, and is obtained with a kneader having at least three vent holes under such conditions that the mean pressure decrease and mean temp. at the vent holes are 10Torr or lower and 230 deg.C or higher, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses an emulsifier for at least a part of the polymerization reaction, which is excellent in thermal stability, resistance to mold contamination during injection molding, has little odor and gas generation during molding. The present invention relates to a polymerized thermoplastic resin composition and a method for producing the same.

[0002]

2. Description of the Related Art Generally, a method for producing a thermoplastic resin by an emulsion polymerization method is easier to control a reaction rate than other polymerization methods for a thermoplastic resin such as a suspension polymerization method, a bulk polymerization method and a solution polymerization method. That is, it has excellent characteristics such as easy removal of reaction heat supplied by the polymerization reaction, high polymerization rate, and easy production of a polymer having a high degree of polymerization. However, since the emulsifier solidified product remains in the finally obtained resin, it has an adverse effect on the physical properties of the resin such as heat resistance, thermal stability, mold contamination, impact resistance, etc. It has the drawback of generating gas. In addition, the remaining emulsifier coagulum accelerates the side reaction of the aromatic polycarbonate resin, aromatic polyester resin, etc., so that the emulsifier coagulate remains and is melt-kneaded with the aromatic polycarbonate resin, aromatic polyester resin, etc. If this is done, the physical properties of the obtained resin are adversely affected. To suppress a side reaction between the emulsifier coagulated product and the aromatic polycarbonate resin, there is disclosed in JP-A-64
No. 14266 discloses a method in which a disproportionated rosin acid salt or a fatty acid salt is used as an emulsifier used in emulsion polymerization of a styrene resin and coagulation is performed with a strong acid. Although the thermal stability of the obtained resin composition is improved to some extent by this method, the thermal stability when the resin composition is retained at a high temperature for a long time is not yet satisfactory.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above problems and comprises a melt-kneaded product of emulsion-polymerized styrene resin and aromatic polycarbonate resin and / or aromatic polyester resin. With a small amount of residual emulsifier solidified product, thermal stability as compared with conventional resins, excellent mold stain resistance, and a resin composition with less odor and gas generation during molding and a method for producing the same. To do.

[0004]

The inventors of the present invention have made diligent efforts to solve the above-mentioned problems, and as a result, provided three or more vent ports in a kneader at the time of melt-kneading, and provided the vent ports with high decompression and high temperature. It was found that, by setting the above, it is possible to remove the remaining emulsifier solidified product at the same time as the melt kneading, and obtain a thermoplastic resin composition having good physical properties, and arrived at the present invention.

That is, the first aspect of the present invention is that the styrene resin 1 is obtained by polymerizing at least a part of the polymerization reaction with an emulsifier.
A melt-kneaded product of 0 to 90 parts by weight (A) and 90 to 10 parts by weight of an aromatic polycarbonate resin and / or an aromatic polyester resin (B), and the residual emulsifier solidified product is the styrene resin (A). A second aspect of the present invention is a thermoplastic resin composition characterized in that it is 1.2 parts by weight or less with respect to 100 parts by weight, and a styrene resin 10 obtained by polymerizing at least a part of a polymerization reaction using an emulsifier. ˜90 parts by weight (A) and 90 to 10 parts by weight (B) of aromatic polycarbonate-based resin and / or aromatic polyester-based resin are melt-kneaded, three or more vent ports are connected to the kneading machine with a vacuum device. Provided, the average pressure reduction degree of each vent port is 10 Tor
The present invention is directed to a method for producing a thermoplastic resin composition, which is characterized in that the average temperature of each vent port is maintained at 230 ° C. or higher, and r or less.

The emulsifier coagulated product in the present invention is a substance obtained by reacting a latex containing an emulsifier mixed during emulsion polymerization with a coagulant to obtain a substance having a long molecular chain. Refers to the other substance. For example,
When coagulation is performed using sodium oleate as an emulsifier and hydrochloric acid as a coagulant, oleic acid and sodium chloride are produced after coagulation. Among them, oleic acid is referred to as an emulsifier coagulated product.

Styrenic resin (A) used in the present invention
Is a resin polymerized by using an emulsifier for at least a part of the polymerization reaction, and in addition to a resin in which the polymerization reaction is entirely carried out by an emulsion polymerization method, it is polymerized by an emulsion polymerization method after being polymerized by using another polymerization method. The resin which has been subjected to the above step, the resin which has been polymerized by the emulsion polymerization method, and has been polymerized by another polymerization method, and the like are also included. Also,
A mixture of a resin polymerized by using an emulsion polymerization method and a resin polymerized by another method may be used for at least a part of the polymerization reaction.

The resin used is a resin obtained by polymerizing a single aromatic vinyl compound, a resin obtained by copolymerizing a plurality of aromatic vinyl compounds, or a resin obtained by copolymerizing another vinyl compound copolymerizable therewith. For example, polystyrene,
Poly α-methyl styrene, styrene / α-methyl styrene copolymer, aromatic vinyl / cyanide vinyl copolymer,
Aromatic vinyl / (meth) acrylic acid copolymer, aromatic vinyl / (meth) acrylic acid ester copolymer, aromatic vinyl / (meth) acrylic acid / (meth) acrylic acid ester copolymer, aromatic vinyl -Modified maleimide copolymer, aromatic vinyl-maleic anhydride copolymer, aromatic vinyl-olefin copolymer, aromatic vinyl-diene copolymer, aromatic vinyl-cyanide-diene copolymer, Aromatic vinyl / (meth) acrylic acid / diene copolymer, aromatic vinyl / (meth) acrylic acid ester / diene copolymer, aromatic vinyl / modified maleimides / diene copolymer, aromatic vinyl / maleic anhydride Examples thereof include acid / diene copolymers, aromatic vinyl / olefin / diene copolymers, aromatic vinyl / olefin / vinyl cyanide copolymers, and the like. These are used alone or in combination of two or more.

As the emulsifier used in emulsion polymerization, generally known anionic surfactants, cationic surfactants, amphoteric surfactants and nonionic surfactants can be used. They may be used alone or in combination of two or more.

Examples of the anionic surfactant include higher fatty acid salts, higher alcohol sulfates, higher alkyl sulfonates, sulfated fat and fatty acid salts, sulfonated higher fatty acid salts, higher alkyl phosphoric acid ester salts, and higher fatty acid esters. Sulfates, sulfonates of higher fatty acid esters, sulfates of higher alcohols / ethers, sulfonates of higher alcohols / ethers, condensates of higher fatty acids and proteolytic amino acids, condensates of higher fatty acids and amino acids, higher fatty acids Alkylolized sulfuric acid ester salts of amides, alkylated sulfonates of higher fatty acid amides, sulfosuccinic acid ester salts, alkylbenzene sulfonates, alkylphenol sulfonates, alkylnaphthalene sulfonates, alkyldiphenyl rings Sulfonates, ketone compounds of alkylallyl sulfonates, alkylbenzene imidazole sulfonates, naphthenates, naphthenyl alcohol sulfate salts, resin acid salts, resin acid alcohol sulfate ester salts, lignin sulfonates, etc. These are used alone or in combination of two or more.

As the cationic surfactant, primary amine salts, secondary amine salts, tertiary amine salts, alkyl quaternary amine salts, alkylbenzene quaternary amine salts, quaternary amine having a nitrogen ring. Examples thereof include amine salts, which may be used alone or in combination of two or more.

As the amphoteric surfactant and nonionic surfactant, betaine-type surfactants, glycerin esters of fatty acids, glycol esters of fatty acids, pentaerythritol esters of fatty acids, sorbitan and mannitane esters of fatty acids. , Higher fatty acid amide condensates, higher alcohol condensates, higher alkylamine condensates, higher fatty acid amide condensates, higher alkyl mercaptan condensates, alkylphenol condensates, polyethyleneimines, polyethylene oxides, polyoxazolines And the like. These may be used alone or in combination of two or more.

Among these emulsifiers, it is preferable to use an anionic surfactant having a low boiling point, such as a fatty acid salt. The emulsifiers may be used alone or in combination of two or more. The ratio of the emulsifier and other components such as water and monomers can be set arbitrarily,
It is preferable that the amount of the emulsifier is small within the range in which the polymerization is possible.

In emulsion polymerization, usually used polymerization initiators, chain transfer inhibitors, polymerization terminators, scale generation inhibitors and the like can be used in arbitrary proportions.

The coagulant used for coagulating the latex obtained by emulsion polymerization is also not particularly limited. For example, when an anionic surfactant is used as an emulsifier, calcium chloride, magnesium chloride, Calcium sulfate, magnesium sulfate, aluminum sulfate, hydrochloric acid,
Known compounds such as sulfuric acid may be used alone or in combination of two or more, but it is preferred that the emulsifier coagulated product after coagulation has a low boiling point.

Examples of the aromatic polycarbonate resin which is one of the components (B) used in the present invention include:
4′-dihydroxydiphenylalkane-based polycarbonate resin can be used. Specifically, bisphenol A
And a polycarbonate obtained by a transesterification method, a phosgene method or the like using bisphenol A partially substituted with another functional group as a dihydroxy component.

As an example of the aromatic polyester resin which is another type of the component (B) used in the present invention, an aromatic dicarboxylic acid, its ester or ester-forming derivative and a diol are condensed by a known method. The thing obtained by doing is mentioned.

Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, p-hydroxybenzoic acid,
Examples thereof include adipic acid, sebacic acid, naphthalenedicarboxylic acid, and ester-forming derivatives thereof, which may be used alone or in combination of two or more.

Examples of the diol include polymethylene glycol having a plurality of carbon atoms such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, bisphenol A, And derivatives thereof, which may be used alone or in combination of two or more.

Specific examples of the aromatic polyester thus obtained include polyethylene terephthalate, polybutylene terephthalate, polycyclohexane dimethylene terephthalate, polyarylate and the like, and these may be used alone or in combination of two or more.

The ratio of the styrene resin (A) polymerized by using an emulsifier for at least a part of the polymerization reaction and the aromatic polycarbonate resin and / or the aromatic polyester resin (B) is 10 (A). ~ 90 parts by weight,
(B) is 90 to 10 parts by weight. When (A) is less than 10 parts by weight and (B) is less than 10 parts by weight, (B),
(A) Physical properties are not so different from those of the individual resins, and good characteristics as a mixture are not exhibited. Preferably,
(A) 20 to 80 parts by weight, (B) 80 to 20 parts by weight, and more preferably (A) 30 to 70 parts by weight, (B) 70 to 30 parts by weight. Further, the ratio of the polycarbonate resin and the aromatic polyester resin in (B) is not particularly limited.

As the kneading machine used in the present invention, a kneading machine generally used for thermoplastic resins can be applied as long as it is a melt kneading machine having three or more vent ports. For example, a single-screw extruder, a twin-screw extruder, a multi-screw extruder, or the like.

Since the vent port must be kept at a reduced pressure, at least a part of the resin in the kneading machine must be melted before reaching the vent port, so that the pressure can be reduced. A general vacuum device that is directly connected to the vent port can be used, but it is preferable to select a vacuum device having a high decompression ability so that the vacuum degree can be maintained as high as possible.

It is necessary to install three or more vent ports, and if the number is less than this, the emulsifier coagulation product cannot be sufficiently removed. It is preferable to provide four or more vent ports.

It is necessary to maintain the average degree of pressure reduction at each vent port at 10 Torr or less. If it is greater than 10 Torr, it becomes difficult to sufficiently remove the emulsifier coagulated product from the resin composition. It is preferably 7 Torr or less, more preferably 4 Torr or less. In addition, it is preferable that the area of the opening of the vent port is large because the molten resin is exposed to a reduced pressure for a long time.

In order to remove the emulsifier solidified product by venting, it is necessary to keep the average temperature of each vent port at a temperature of 230 ° C. or higher. If the temperature is lower than 230 ° C, the emulsifier solidified product cannot be sufficiently removed. Furthermore, it is preferable to keep the temperature higher than the range where the resin does not deteriorate or decompose. The kneading conditions during the melt-kneading are preferably such that the resin is exposed to the reduced pressure at the vent port for as long as possible in order to prevent the resin from deteriorating for a long time.

The amount of emulsifier solidified product finally remaining in the thermoplastic resin obtained by melt-kneading is
The amount is preferably 1.2 parts by weight or less based on 100 parts by weight of the styrene-based thermoplastic resin composition (A) polymerized by using an emulsifier. If more than 1.2 parts by weight of emulsifier solidified product remains after 100 parts by weight of (A) after melt-kneading,
Physical properties such as thermal stability are not sufficiently improved. More preferably, it is 1.0 part by weight or less with respect to 100 parts by weight of (A).

At the time of kneading, in addition to the styrene-based thermoplastic resin composition (A) polymerized with an emulsifier and the aromatic polycarbonate-based resin and / or aromatic polyester-based resin (B), an arbitrary thermoplastic resin is further added. It is also possible to knead one kind or two or more kinds at the same time. In addition, if necessary, usually well-known antioxidants, heat stabilizers, lubricants, plasticizers, flame retardants, flame retardant aids, ultraviolet absorbers, pigments, antistatic agents, nucleating agents, dispersants, and phases. Additives such as solubilizers can be used alone or in combination of two or more. However, in order to prevent the additive from being removed from the vent at the same time as the emulsifier coagulation product, it is preferable to select and use one having a boiling point as high as possible and one having good thermal stability. Also,
As other additional components, organic / inorganic fillers / reinforcing agents such as glass fiber, mica, talc, wollastonite, potassium titanate, calcium carbonate, silica, etc.
It is possible to use one kind or a combination of two or more kinds.

The method of molding the thermoplastic resin composition produced by the present invention is not particularly limited, and molding methods generally used for thermoplastic resins, that is, injection molding, blow molding, extrusion molding, and sheets are used. Forming, roll forming,
A molding method such as press molding or laminated molding can be applied.

[0030]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited thereto. In the following description, "part" and "%" represent "part by weight" and "% by weight", respectively, unless otherwise specified. Examples 1 to 10 and Comparative Examples 1 to 8 (a) Production of styrene resin (A) obtained by polymerizing at least a part of the polymerization reaction with an emulsifier In a reaction vessel equipped with a stirrer and a cooler in a nitrogen stream, I charged the substance. Water 210 parts Sodium formaldehyde sulfoxylate 0.4 parts Ferrous sulfate 0.0025 parts Disodium ethylenediaminetetraacetate 0.01 parts Emulsifier shown in Table 1 2.0 parts After heating and stirring at 65 ° C in a nitrogen stream The following monomer mixture was continuously added dropwise over 6 hours. α-Methylstyrene 75 parts Acrylonitrile 25 parts Cumene hydroperoxide 0.45 parts Tertiary decyl mercaptan 0.41 parts After the dropping is completed, the mixture is further stirred at 65 ° C. for 1 hour to complete the polymerization, and α-methylstyrene-acrylonitrile. A copolymer latex (1) was obtained.

The following substances were placed in a reaction vessel equipped with a stirrer and a cooler in a nitrogen stream. Water 180 parts Sodium formaldehyde sulfoxylate 0.4 parts Ferrous sulfate 0.0025 parts Disodium ethylenediaminetetraacetate 0.01 parts Emulsifier shown in Table 1 2.0 parts After heating and stirring at 70 ° C in a nitrogen stream The following monomer mixture was continuously added dropwise over 7.5 hours. Styrene 71 parts Acrylonitrile 29 parts Cumene hydroperoxide 0.15 parts Tertiary decyl mercaptan 0.45 parts After the completion of dropping, the mixture is further stirred at 70 ° C. for 1 hour to complete the polymerization, and the styrene-acrylonitrile copolymer latex ( 2) was obtained.

The following substances were placed in a reaction vessel equipped with a stirrer and a cooler in a nitrogen stream. Water 250 parts Potassium persulfate 0.5 part Butadiene 100 parts Tertiary decyl mercaptan 0.3 parts Emulsifier shown in Table 1 2.0 parts Polymerization was carried out at a polymerization temperature of 60 ° C.
When the content reached 0%, the polymerization was stopped and unreacted butadiene was removed to obtain a polybutadiene latex (3).

Next, a reaction vessel equipped with a stirrer and a cooler was charged with the following substances and the polybutadiene latex containing the emulsifier obtained above in a nitrogen stream. Water 240 parts Sodium formaldehyde sulfoxylate 0.2 parts Ferrous sulfate 0.003 parts Ethylenediaminetetraacetic acid disodium 0.012 parts Polybutadiene 70 parts After heating and stirring at 60 ° C. in a nitrogen stream, the following single ratios are used. The monomer mixture was continuously added dropwise over 3.5 hours. Styrene 7.35 parts Acrylonitrile 22.65 parts Cumene hydroperoxide 0.27 parts After the completion of dropping, the mixture is further stirred at 70 ° C. for 1 hour to terminate the polymerization, and the polybutadiene-styrene / acrylonitrile graft copolymer latex (4 ) Got.

The above latexes (1), (2) and (4) were uniformly mixed at the ratio (solid content) shown in Table 1, a phenolic antioxidant was added, and a coagulant shown in Table 1 was added. After being solidified by coagulation, it is washed with water, dehydrated and dried, and styrene resin (A1)
~ (A3) were obtained. In the washing step, the emulsifier coagulated product was partially washed and flowed out of the system.

[0035]

[Table 1]

As the aromatic polycarbonate resin and / or aromatic polyester resin (B), the following commercially available products were used.

Aromatic Polycarbonate Resin Idemitsu Petrochemical Co., Ltd. Polycarbonate Tafflon F
N2200A (trade name) Aromatic polyester resin Kanebo Co., Ltd. Polyethylene terephthalate EFG-7
(Product name)

(B) Production of thermoplastic resin composition After adding a hindered phenol antioxidant and a phosphite stabilizer to the above components (A) and (B), the formulations shown in Tables 2 and 3 The mixture was thoroughly mixed and stirred with a super mixer. Then, this was melted and kneaded in a TEX65 twin-screw extruder manufactured by Japan Steel Works under the kneading conditions shown in Tables 2 and 3 while maintaining the vent port under the reduced pressure conditions in Tables 2 and 3 to form pellets. Each of the resin compositions was obtained by converting into a resin.

The obtained resin composition was dried at 110 ° C. for 5 hours using a hot air dryer, and then J150E- manufactured by Japan Steel Works Ltd.
Molding was performed using a P injection molding machine at a cylinder temperature of 285 ° C. Specimen for thermal stability test has cylinder temperature 2
Retention was carried out at 85 ° C. for 10 minutes, and test pieces before and after retention were obtained for comparison.

The amount of residual emulsifier coagulated product was measured under the following conditions. Oleic acid: Pellets were extracted with tetrahydrofuran / hexane solvent and then methylated, Shimadzu GC-1
Nitrogen gas 50ml / mi by 4A gas chromatography
n carrier gas, 10% using FID for detector
Measured at a DEGS 2m column, column temperature 180 ° C, inlet temperature 250 ° C, detector temperature 270 ° C. Dioctyl sulfosuccinic acid: Measured by the methylene blue colorimetric method.

The mold stain resistance is 150 mm × 150.
mm mold square flat plate with 1-point gate from the corner, resin is filled up to 2/3 of the mold with short shot repeatedly 10 times, and visually check the amount of contaminants adhering to the mold. It was evaluated by.

The evaluation test was carried out by the following method. Impact strength is 23 based on ASTM D256
It was evaluated by the IZOD test at 0 ° C. For the retention of IZOD after retention, the IZOD value before and after retention molding was evaluated after retention / before retention. As for the color difference after retention, the discoloration of the test piece before and after retention molding was evaluated by the color difference (ΔE). The smaller the color difference, the better the thermal stability. For the appearance of the molded article after retention, the surface appearance of the molded product obtained immediately after retention molding was visually evaluated.

As is clear from the results of Tables 2 and 3, Comparative Example 1 is Examples 1 and 2, Comparative Example 2 is Example 3, Comparative Example 3 is Examples 4 to 7, and Comparative Example 6 is. Is Example 8 and Comparative Example 7
Comparing with Example 9, respectively, it is shown that in the comparative example, the average degree of vacuum at the vent port is outside the range of the present invention, and thus the emulsifier coagulated product cannot be sufficiently removed, and the physical properties of the obtained resin deteriorate. There is. In addition, since Comparative Example 4 is different from Examples 4 to 7 and Comparative Example 8 is different from Example 10 in that the number of vent ports is outside the range of the present invention, the emulsifier coagulum cannot be sufficiently removed, and It shows that the physical properties of the obtained resin deteriorate.
Further, in Comparative Example 5, since the average temperature of the vent port is out of the range of the present invention, the emulsifier coagulated product cannot be sufficiently removed as compared with Examples 4 to 7, and the physical properties of the obtained resin are deteriorated. ing.

[0044]

[Table 2]

[0045]

[Table 3]

[0046]

As described above, the resin composition of the present invention is
It has excellent thermal stability and resistance to mold contamination, and it does not generate odor or gas during molding. Further, according to the production method of the present invention, the emulsifier coagulated product of the resin polymerized with the emulsifier can be easily removed.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C08L 69/00 LPP

Claims (2)

[Claims] 1. A styrene-based resin obtained by polymerizing at least a part of a polymerization reaction by using an emulsifier (A).
And an aromatic polycarbonate-based resin and / or an aromatic polyester-based resin (90 to 10 parts by weight (B)), and the residual emulsifier solidified product is 1.2 per 100 parts by weight of the styrene-based resin (A). A thermoplastic resin composition characterized by being less than or equal to parts by weight. 2. A styrene-based resin obtained by polymerizing at least a part of a polymerization reaction with an emulsifier, in an amount of 10 to 90 parts by weight (A).
When melting and kneading 90 to 10 parts by weight (B) of aromatic polycarbonate resin and / or aromatic polyester resin, the kneader is provided with three or more vent ports connected to a vacuum device, and the average of each vent port A method for producing a thermoplastic resin composition, characterized in that the degree of vacuum is 10 Torr or less and the average temperature of each vent is maintained at 230 ° C. or more.