JPH0575019B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing a polycarbonate resin composition, and more specifically, the present invention relates to a method for producing a polycarbonate resin composition that has excellent solvent resistance and various properties such as impact resistance, rigidity, moldability, and appearance. Relating to a method of manufacturing. The present invention can be effectively used in the production of molded product materials for automobile bumpers, home appliances, etc. [Prior Art and Problems to be Solved by the Invention] Polycarbonate resins have conventionally been known as molding resins that have excellent physical properties such as rigidity and thermal properties. However, polycarbonate resin molded articles have the disadvantage of being susceptible to cracking when subjected to concentrated stress in the presence of certain solvents. In addition, the polycarbonate resin has a high melt viscosity,
Therefore, the molding temperature and molding pressure are high compared to other resins, which is considered to be a difficult point in molding. It has been proposed to blend various polyesters into polycarbonate resin in order to improve the solvent resistance and low moldability, which are disadvantages of polycarbonate resin, without significantly impairing the excellent physical properties inherent in polycarbonate resin. There is. For example, a composition in which polyalkylene terephthalate, which is a copolymerization of a bifunctional carboxylic acid component and a diol component having a large amount of aromatic rings, is blended with a polycarbonate resin (Japanese Patent Publication No. 57-16137,
No. 54-37633, Japanese Patent Application Laid-Open No. 50-102648) have been proposed. However, since this composition has a high aromatic content in the diol component, it has drawbacks such as the occurrence of discoloration during molding, and is also economically disadvantageous because the diol component is expensive. Also known is a composition in which a polyalkylene terephthalate containing cyclohexanedimethanol as a diol component is blended with a polycarbonate resin (JP-A-53-94536), but this polyalkylene terephthalate has a large decrease in rigidity and is resistant to solvents. There are disadvantages in that the improvement in properties is insufficient and the composition is colored, which limits its uses. The present applicant has already discovered and applied for a composition with improved solvent resistance and mechanical properties by blending polyester resin and rubber-like elastic body with polycarbonate resin (Japanese Patent Laid-Open No. 60-222720
issue). [Means for Solving the Problems] As a result of further detailed study on the method for producing the above composition, the present inventors prepared a masterbatch of polycarbonate resin and a rubber-like elastic body in advance, and then added the remaining amount to this masterbatch. It was discovered that solvent resistance was further improved by blending polycarbonate resin and polyester resin, and based on this knowledge, the present invention was completed. That is, in the present invention, a part of polycarbonate resin and a rubber-like elastic body are kneaded in advance to prepare a masterbatch, and the masterbatch and the remaining polycarbonate resin and polyester resin are kneaded to form a mixture of 30 to 90% by weight of polycarbonate resin and polyester resin. 6-45% by weight and rubber-like elastic body 1
The present invention provides a method for producing a polycarbonate resin composition, characterized in that the composition consists of 25% by weight. In the present invention, a masterbatch is first prepared by kneading a portion of the polycarbonate resin and a rubber-like elastic body. Here, the blending ratio of the polycarbonate resin and the rubber-like elastic body may be such that the polycarbonate resin to the rubber-like elastic body is 0.3 to 3 (weight ratio), preferably 0.5 to 2 (weight ratio). Kneading of both is done using a drum tumbler, ribbon blender, etc., and then a single-screw extruder.
Using an extruder such as a screw extruder, 250~
This may be carried out by melting and kneading at 300°C, particularly 260 to 280°C. The polycarbonate resin used in the present invention has the following general formula:

[C] (Here, Z is a bond, or alkylene having 1 to 8 carbon atoms, alkylidene having 2 to 8 carbon atoms, or 5 carbon atoms.
~15 cycloalkylene, C5-15 cycloalkylidene, SO ₂ , SO, O, CO or

[Formula] means a group, R means a hydrogen, chlorine or bromine atom or a saturated alkyl group having 1 to 8 carbon atoms, and m represents a number from 0 to 4. ) It is a polymer having a structural unit represented by: This polycarbonate resin is produced by a solvent process, i.e., by reaction of dihydric phenol with a polycarbonate precursor such as phosgene or by reaction of dihydric phenol with a polycarbonate precursor such as phosgene in a solvent such as methylene chloride in the presence of known acid acceptors, molecular weight modifiers, etc. It can be produced by a transesterification reaction with a carbonate precursor such as. Here, as dihydric phenols that can be suitably used, there are bisphenols, and 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) is particularly preferred. Also, bisphenol A
may be partially or entirely replaced with other dihydric phenols. Examples of divalent phenols other than bisphenol A include hydroquinone, 4,4'-dihydroxydiphenyl, bis(4
-hydroxyphenyl)alkane, bis(4-hydroxyphenyl)cycloalkane, bis(4-
Compounds such as hydroxyphenyl) sulfide, bis(4-hydroxyphenyl) sulfone, bis(4-hydroxyphenyl) sulfoxide, bis(4-hydroxyphenyl) ether or bis(3,5-dibromo-4- Examples include halogenated bisphenols such as hydroxyphenyl)propane and bis(3,5-dichloro-4-hydroxyphenyl)propane. These dihydric phenols may be homopolymers or copolymers or blends of two or more dihydric phenols. Furthermore, the polycarbonate resin used in the present invention may be a thermoplastic randomly branched polycarbonate obtained by reacting a polyfunctional aromatic compound with a dihydric phenol and/or a carbonate precursor. From the viewpoint of mechanical strength and moldability, the polycarbonate resin used in the present invention preferably has a viscosity average molecular weight of 10,000 to 100,000, particularly
20,000 to 40,000 is suitable. Furthermore, various rubber-like elastic bodies can be used, but the following are particularly suitable. For example, there is a resin polymer obtained by polymerizing one or more vinyl monomers in the presence of a rubbery polymer mainly composed of alkyl acrylate and/or alkyl methacrylate. As the alkyl acrylate and alkyl methacrylate, those having an alkyl group having 2 to 10 carbon atoms are preferred, and specific examples thereof include ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, n-octyl methacrylate, and the like. These rubber-like polymers mainly composed of alkyl acrylates include 70% by weight or more of the alkyl acrylates and other vinyl monomers that can be copolymerized with the alkyl acrylates, such as methyl methacrylate, acrylonitrile, vinyl acetate, styrene, etc. % by weight or less. In this case, divinylbenzene,
It includes polymers obtained by appropriately adding and reacting polyfunctional monomers such as ethylene dimethacrylate, triallyl cyanurate, and triallyl isocyanurate as crosslinking agents. Vinyl monomers reacted in the presence of this rubbery polymer include aromatic vinyl compounds such as styrene and α-methylstyrene; acrylic esters such as methyl acrylate and ethyl acrylate; methyl methacrylate and methacrylic acid. It refers to monomers such as methacrylic esters such as ethyl, and one or more of these monomers are polymerized. Furthermore, these monomers are polymerized with other vinyl monomers, such as vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; vinyl esters such as vinyl acetate and vinyl propionate. The polymerization reaction can be carried out by various methods such as bulk polymerization, suspension polymerization, and emulsion polymerization, and those produced by emulsion polymerization are particularly preferred. It is necessary that the resin polymer thus obtained contains the above-mentioned rubber component in an amount of 20% by weight or more. Examples of such resin polymers include MAS resin elastomers such as graft copolymers of 60 to 80% by weight of n-butyl acrylate, styrene, and methyl methacrylate;
Examples include MS resin elastomer which is a copolymer of styrene and methyl methacrylate. MAS above
Examples of the resin elastomer include "KM-330" (trade name) manufactured by Rohm & Haas Co., Ltd. and "Metablen W529" (trade name) manufactured by Mitsubishi Rayon Co., Ltd. In addition, one type of vinyl monomer or There are resin polymers obtained by polymerizing two or more types. As the alkyl acrylate and alkyl methacrylate, those mentioned above are used. In addition, examples of polyfunctional polymerizable monomers having conjugated diene type double bonds include conjugated diene compounds such as butadiene, and compounds having non-conjugated double bonds in addition to conjugated diene type double bonds in one molecule. can be mentioned. . Specifically, such compounds include, for example,
1-Methyl-2-vinyl-4,6-heptadien-1-ol; 7-methyl-3-methylene-1,
6-octadiene; 1,3,7-octatriene, etc. When copolymerizing the above alkyl acrylate and/or alkyl methacrylate with a polyfunctional polymerizable monomer having a conjugated diene type double bond, an aromatic vinyl compound such as styrene or α-methylstyrene is used as necessary; acrylonitrile,
Vinyl monomers such as vinyl cyanide compounds such as methacrylonitrile; vinyl ester compounds such as vinyl acetate and vinyl propionate; vinyl ether compounds such as methyl vinyl ether; and vinyl halide compounds such as vinyl chloride can also be added. . Furthermore, a crosslinking agent such as ethylene dimethacrylate or divinylbenzene may be added. In addition, when producing a copolymer by copolymerizing the above alkyl acrylate and/or alkyl methacrylate with a polyfunctional polymerizable monomer having a conjugated diene type double bond, the conjugated diene type double bond The polyfunctional polymerizable monomer should be used in a proportion of 0.1 to 20% by weight, preferably 1 to 10% by weight, in the copolymer. The vinyl monomers to be polymerized with the copolymer thus obtained include those listed above, and one or more of these may be used. The polymerization reaction can be carried out by various methods such as bulk polymerization, suspension polymerization, and emulsion polymerization, and those produced by emulsion polymerization are particularly preferred. Preferred examples of such resin polymers are shown below. The first method is to copolymerize an alkyl (meth)acrylate such as n-butyl acrylate, 2-ethylhexyl acrylate, or methyl methacrylate with butadiene and a small amount of a crosslinking agent such as ethylene dimethacrylate or divinylbenzene by a conventional method. It is a graft copolymer obtained by adding a vinyl monomer such as styrene, acrylonitrile, vinyl chloride, etc. as a graft component monomer to the obtained latex, and graft polymerizing it by a conventional method. The second method is to copolymerize the above alkyl (meth)acrylate with a compound having a non-conjugated double bond in addition to a conjugated diene type double bond in one molecule, and graft it onto the resulting latex. Adding a vinyl monomer as described above as a component monomer,
This is a graft copolymer obtained by graft polymerization using a conventional method. In addition, here, the graft polymerization is 1
It may be carried out in stages, or it may be carried out in multiple stages by changing the components of the graft component monomer in multiple stages. More specifically, such resin polymers include:
MABS resins such as graft copolymers obtained by adding styrene and methyl methacrylate to a rubber latex obtained by copolymerizing octyl acrylate and butadiene at a ratio of 7:3. There is an elastic body. Furthermore, there are MBS resin elastomers such as graft copolymers obtained by adding styrene to rubber latex obtained by copolymerizing methyl methacrylate and butadiene and performing graft polymerization. The above MABS resin elastomers include "HIA 15", "HIA 28", and "HIA 30" manufactured by Kureha Chemical Industry Co., Ltd.
(All items indicate product names.) etc. are preferably used. Furthermore, other rubber-like elastic bodies, such as ABS resin elastic bodies, can also be used. Next, the masterbatch obtained as described above and the remaining polycarbonate resin and polyester resin are kneaded to obtain the desired polycarbonate resin composition. The composition here comprises 30-90% by weight of polycarbonate resin, preferably 40-90% by weight of polycarbonate resin.
75% by weight, polyester resin 6-45% by weight, preferably 15-40% by weight, and rubber-like elastic body 1-25% by weight
It is necessary that the amount is 2% to 20% by weight, and if it is other than this, the object of the present invention cannot be achieved. That is, if the blending ratio of polyester resin is less than 6% by weight, the solvent resistance and rigidity of the resin composition will be insufficient, while if it exceeds 45% by weight, the impact resistance and solvent resistance of the resin composition will be insufficient. This is not appropriate as it causes a drop in the temperature. Also,
If the blending ratio of the rubber-like elastic body is less than 1% by weight, the impact resistance and solvent resistance of the resin composition will decrease;
If it exceeds 25% by weight, the rigidity of the resin composition will decrease,
This is not preferable because the appearance becomes poor. The above kneading may be carried out by melting and kneading at 250 to 300°C, particularly 260 to 280°C, using an extruder such as a single screw extruder or a twin screw extruder. Note that the polyester resin used in the present invention includes polyester ether elastomer and polyester, and either one of them is used alone or both are used in combination. The polyester ether elastomer used includes a difunctional carboxylic acid component, an alkylene glycol component, and a polyalkylene glycol component. The polyester ether elastomer used here has the following general formula:

〔Example〕

Next, the present invention will be explained in detail using examples. Examples 1 to 6 Bisphenol A-based polycarbonate resin (manufactured by Idemitsu Petrochemical Co., Ltd., "A-3000", viscosity average molecular weight
29500), MAS resin (manufactured by Rohm & Haas, KM330) and MABS resin (manufactured by Kureha Chemical Industry Co., Ltd., HIA 15) as rubber-like elastic bodies, polyester ether elastomer (terephthalic acid component: 56% by weight, A copolymer of 21% by weight of ethylene glycol component and 23% by weight of polyethylene glycol (average molecular weight 1000) component) and polyethylene terephthalate (manufactured by Mitsubishi Rayon Co., Ltd., Diamondite AA200, intrinsic viscosity 1.20 dl/g) were prepared. A part of polycarbonate resin (50 parts by weight),
MAS resin or MABS resin (50 parts by weight) as a rubbery elastic body was mixed in a drum tumbler, then supplied to an extruder and melted and kneaded at 270°C to obtain a masterbatch. Next, the obtained masterbatch is mixed with the remaining polycarbonate resin and polyester ether elastomer and/or polyethylene terephthalate as the polyester resin, and then melt-kneaded at 270°C using an extruder to obtain a composition shown in Table 1. A polycarbonate resin composition was produced. Table 1 shows the test results for the obtained polycarbonate resin composition. In addition, the test method and its evaluation were performed by the following method. (1) Solvent resistance Using a JIS No. 1 dumbbell under a surface strain of 0.7%,
Toluene/isooctane/methanol=42.5/
After immersing in a mixed solvent of 42.5/15 (volume%) for 5 minutes,
Evaluation was made based on the elongation at break (%) with respect to the original test piece when a tensile test was performed at 50 mm/min. The results are shown as the average value of elongation at break (%) when the tensile test was conducted six times. (2) Izotsu impact strength Compliant with ASTM D256 (3) Appearance The obtained polycarbonate resin composition was injection molded at an extruder cylinder temperature of 280°C, and the length was 120 mm and the width was 120 mm.
A flat plate of 120 mm and 3 mm thickness was obtained, and the surface appearance of this flat plate was visually judged. 〇: Good reference examples 1 to 6 Using the same polycarbonate resin, rubber-like elastic body, and polyester resin as used in Examples 1 to 6, the entire amounts were mixed at the same time, and the same conditions as Examples 1 to 6 were used. Polycarbonate resin compositions having the compositions shown in Table 1 were prepared by melt-kneading and then tested in the same manner as in Examples 1 to 6. The results are shown in Table 1. Comparative Example 1 A masterbatch was prepared in the same manner as in Example 3, except that the blending ratios of the polycarbonate resin, rubber-like elastic body, and polyester resin were changed as shown in Table 2, and then kneaded to form a polycarbonate resin. Compositions were prepared and tested. The results are shown in Table 2. Comparative Example 2 A masterbatch was prepared in the same manner as in Example 5, except that the blending ratios of the polycarbonate resin, rubber-like elastic body, and polyester resin were changed as shown in Table 2, and then kneaded to form a polycarbonate resin. Compositions were prepared and tested. The results are shown in Table 2.

【table】

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Claims (1)

[Scope of Claims] 1. A masterbatch is prepared by kneading a part of a polycarbonate resin and a rubber-like elastic body in advance, and the masterbatch is kneaded with the remaining polycarbonate resin and polyester resin to obtain a polycarbonate resin of 30 to 90% by weight, Polyester resin 6
45% by weight of a polycarbonate resin composition and 1 to 25% by weight of a rubbery elastic material. 2. The manufacturing method according to claim 1, wherein the polyester resin is a polyester ether elastomer and/or a polyester.