JPH0819297B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION 3-1 (Field of Industrial Application) The present invention relates to a thermoplastic resin material excellent in mechanical strength, organic solvent resistance and appearance, which is suitable for industrial parts.

Specifically, polycarbonate (hereinafter abbreviated as PC), polypropylene (hereinafter abbreviated as PP) and a component (hereinafter abbreviated as compatibilizer) for facilitating the mixing of these two components (hereinafter abbreviated as compatibilizer) are obtained by mechanical kneading, The present invention relates to a thermoplastic resin composition excellent in organic solvent property and appearance.

More specifically, obtained by melt-kneading the following components (a), (b) and (c), having both the mechanical strength of PC and the organic solvent resistance of PP, and the appearance of the molded product is excellent, The present invention relates to a thermoplastic resin composition.

(A) A mixture of 10 to 90% by weight of unmodified PC and 90 to 10% by weight of unmodified PP, (b) 1 to 50 parts by weight of modified PC having an aliphatic hydroxyl group at the end based on 100 parts by weight of the total amount of (a). , (C) 1 to 50 parts by weight of modified PP having a carboxyl group based on 100 parts by weight of the total amount of (a).

3-2 (Prior Art) A number of inventions have been conventionally made regarding a mixed composition of PC and PP. As a composition in which PC and PP are simply mixed to increase the rigidity, Japanese Patent Publication No. 40-13664 and Japanese Unexamined Patent Publication No. 59-223 are known.
There is a 741 issue. Both of them have succeeded in increasing the rigidity to some extent, but since the compatibility of both components is extremely low,
When such a composition is formed into a molded product by a molding processing method such as injection molding, delamination occurs in layers and the appearance is significantly impaired, which makes it difficult to put into practical use.

As an example of using a modified polypropylene in place of PP to improve the compatibility between PC and PP, JP-A-57-123251
No. 59-223742, 57-125253, but usually the terminal of PC is a terminal terminator or molecular weight regulator (for example, p-
Tertiary butylphenol, phenols and other monovalent phenols) or long-chain alkylphenols for improving fluidity are used for end capping, so modified polyolefins can effectively achieve compatibilization. It is hard to think.

In addition, as a method of compatibilizing PC and polyolefin, JP-A-57-200444, JP-A-57-200445, JP-A-58-8759, JP-A-58-201842, etc., modified polyolefin A method of mixing PC with PC in some form has been introduced, both of which are intended to improve the quality of PC by lowering the content of the polyolefin component, or to devise based on polyethylene. There is no description to make full use of the performance of both PP and PP.

3-3 (Problems to be Solved by the Invention) The present inventors combine the excellent mechanical properties (flexural modulus and impact resistance) of PC with the excellent moldability and organic solvent resistance of PP. In order to develop new molding materials, we have been conducting research on blends of PC and PP. As a result, PC
In a mixed system of PP and PP, when one of the resins forming the disperse phase shows a fine dispersion of several microns, it was found that the physical properties are remarkably improved, and a detailed study of a method for economically making the dispersion fine Then, the present invention was achieved.

3-4 (Means for Solving Problems) First, PC and PP having different molecular weights were selected, and a melt-kneading experiment was performed on the individual materials of both materials by changing the mixing composition ratio. It seems that which resin forms the continuous phase and the dispersed phase depends on the combination of the molecular weights and the composition ratio, but as long as the usual injection molding material is used, the composition ratio of PC is better than that of PP. Large (60-70% by weight or more)
At this time, PC formed a continuous phase, and when the composition ratio of PC was smaller than that, PP formed a continuous phase. In each case, the molded product obtained by injection molding of the composition was evaluated, and as a result, the dispersed phase had a dispersed particle size as large as several tens to several hundreds of microns, and the impact resistance was particularly low in terms of physical properties. Moreover, the appearance of the molded product was extremely poor due to delamination. The reason for this is that the two resins are not compatible with each other, so the dispersion does not become finer to a certain degree or less by melt-kneading, and during injection molding, the dispersed phases agglomerate in the process of cooling and solidification and a large dispersion occurs. May occur. Further, regarding the poor appearance, it is considered that due to high shearing force during injection molding, both resins having poor compatibility are easily separated to cause delamination.

Next, in order to improve the compatibility between the two resins and to examine the possibility of improving the above-mentioned problems, various modified polyolefins introduced by the published patents were mixed with PC instead of PP, and the characteristics were improved. Was evaluated. The modified polyolefins tested were maleic anhydride modified PP, glycidyl methacrylate modified PP, ethylene / acrylic acid copolymer, and ethylene / vinyl acetate / glycidyl metaacrylate copolymer. In all cases, the effect of slightly refining the dispersion was recognized, but it was far from the target dispersion.

From the above situation, the inventors feel that it is not possible to remarkably improve the compatibility with PC simply by using the modified polyolefin, and it is necessary to positively add a component having an affinity with PC. It was As a result of various studies, the component that has the best compatibility with PC is considered to be PC itself,
As a compatibilizer for melt kneading of PP, it was recalled that modified PC was further added in addition to modified PP. What is modified PP and modified PC?
If they exist independently in the composition, the compatibilizing effect cannot be expected, and it is necessary that they are chemically bonded to each other relatively easily in the process of melt kneading. As a result of research focusing on this point, by adding a modified PC having an aliphatic hydroxyl group at the terminal and a modified PP having a carboxyl group to a mixture of unmodified PC and unmodified PP, excellent properties can be obtained. The present invention was completed by obtaining a composition having both of the following.

3-4-1 Components (1) Unmodified PC The unmodified PC used in the present invention is prepared by reacting an aromatic hydroxy compound or a small amount of polyhydroxy compound with phosgene or a diester of carbonic acid. It is a thermoplastic aromatic polycarbonate polymer which may be branched. Examples of aromatic dihydroxy compounds are 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A), tetramethylbisphenol A, tetrabromobisphenol A, bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone. ,
Resorcinol, 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl)
Sulfone, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) ketone, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4- Hydroxyphenyl) cyclohexane, etc., and bisphenol A is particularly preferable. Further, in order to obtain a branched aromatic polycarbonate resin, phloroglucin, 4,6-dimethyl-2,4,
6-tri (4-hydroxyphenyl) heptene-2,4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptane, 2,6-dimethyl-2,4,6-tri (4- Hydroxyphenyl) heptene-3,4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptane, 1,3,5-tri (4-hydroxyphenyl) benzene, 1,1,1-tri Polyhydroxy compounds exemplified by (4-hydroxyphenyl) ethane, and 3,3-bis (4-hydroxyaryl) oxindole [= isatin (bisphenol)], 5-chloroisatin, 5,7-dichloroisatin, 5- Bromoisatin or the like is used as a part of the dihydroxy compound, for example, 0.1 to 2 mol%.
With a polyhydroxy compound. Further, monovalent aromatic hydroxy compounds suitable for controlling the molecular weight are m- and
p-methylphenol, m- and p-propylphenol,
p-bromophenol, p-tert-butylphenol and p
-Preferable are linear alkyl-substituted phenols. Typical examples of the aromatic polycarbonate resin include a bis (4-hydroxyphenyl) alkane compound, particularly a polycarbonate containing bisphenol A as a main raw material.
A polycarbonate copolymer obtained by using at least one kind of aromatic dihydroxy compound in combination, a trivalent phenol type, and a branched polycarbonate obtained by using a small amount of compounds in combination can also be mentioned. The aromatic polycarbonate resin may be used as a mixture of two or more kinds.

(2) Unmodified PP crystalline propylene homopolymer, crystalline propylene-ethylene block or random copolymer, or a mixture of these crystalline propylene-based polymers and an elastomer is used. Melt flow rate of crystalline propylene-based polymers and mixtures of these and elastomers (MF
R: g / 10 minutes, 230 ° C, load 2.16kg) is 0.1 to 70, especially 0.
1 to 50 is preferable. If the MFR is less than 0.1, there will be molding problems, and if it is 70 or more, the impact resistance will be uncertain.

(3) Modified PC having an aliphatic hydroxyl group at the end thereof Modified PC having an aliphatic hydroxyl group at the end of the present invention
The production method of the conventional polycarbonate resin is different from the production method of the conventional polycarbonate resin, except that an aromatic compound having an aliphatic hydroxyl group and a phenolic OH group is used as a molecular weight modifier or a terminal terminator. The manufacturing method similar to the manufacturing method of is sufficient.

That is, in the interfacial polymerization method, after reacting a dihydric phenol compound and phosgene in the presence of an organic solvent inert to the reaction and an aqueous alkali solution, the molecular weight modifier and a tertiary amine or a quaternary ammonium salt are reacted. In the pyridine method, the dihydric phenol compound and the molecular weight modifier are dissolved in pyridine or a mixed solution of pyridine and an inert solvent, and phosgene is blown to directly obtain a polycarbonate resin. Is. In the interfacial polymerization method, the molecular weight modifier may be added during the reaction between the dihydric phenol compound and phosgene.

Examples of the molecular weight modifier used include 4-hydroxymethylphenol, 4-hydroxyethylphenol, and 2,6-dihydroxymethylphenol. The amount used is 100 to 0.5 mol% based on the dihydric phenol compound, preferably Is 20
In the present invention, a conventionally known molecular weight agent can be used in combination with the above compound.

(4) Homopolymer of modified PP propylene having a carboxyl group, a copolymer of 1 or propylene with other α-olefins, or a blend of these with a thermoplastic elastomer and containing a carboxyl group Are all included.

That is, as a method for obtaining these, (i) a method of randomly, block- or graft-copolymerizing a polymerizable monomer containing a carboxyl group, (ii) a compound containing a reactive group present in the resin molecule and a carboxyl group Alternatively, a method of reacting with a compound that produces a carboxyl group by reaction, a method of (iii) modification such as oxidation or hydrolysis, and the like correspond thereto. Among them, the method by copolymerization and the method by hydrolysis or thermal decomposition are preferable because the carboxyl group can be easily introduced and the amount of the introduced carboxyl group can be easily controlled. Further, graft copolymerization is preferable because the compatibility of PC and PP can be improved by introducing a small amount of a carboxyl group and the physical properties of PP used for modification are not significantly impaired.

Examples of the polymerizable monomer having a carboxyl group include acrylic acid, methacrylic acid, maleic acid, itaconic acid, hymic acid, and their anhydrides. Among them, acrylic acid and maleic anhydride are preferable.

The amount of the carboxyl group contained in the modified PP is 5 × 10 ⁻⁵ to 5 × 10 ⁻¹ mol / 100 g, preferably 1 × 10 ⁻⁴ to 1 × 10 ⁻¹ mol / 100 g, particularly preferably 5 × 10 5. ^-4 to 5
× 10 ^-2 . If this value is less than 5 × 10 ^-5 , PC and PP
The effect of compatibilization is less, and when it is 5 × 10 ⁻¹ or more, the dispersed state of the dispersed phase in the composition is not improved.

(5) Additives, etc. In the composition according to the present invention, other thermoplastic resins, resin components other than thermoplastics, elastomers, pigments, organic / inorganic fillers, etc. may be added to the composition of the present invention, as required. , Can also be added.

Further, in order to accelerate the reaction between the modified PC and the modified PP and enhance the effect as the compatibilizing agent, a small amount of paratoluenesulfonic acid or the like can be added as a reaction catalyst.

3-4-2 Composition Ratio of Constituent Elements By combining the modified PC (b) having a hydroxyl group and the modified PP (c) having a carboxyl group of the present invention, the composition ratio of PC to PP can be any value. Good compatibility is obtained even if there is, but from the balance of mechanical strength and organic solvent resistance, the composition ratio of PC and PP is in the range of 10:90 to 90:10, preferably 20:80. 80 to 20, more preferably 30
70 to 70 to 70. If PC is less than 10% by weight, high elastic modulus cannot be expected, and if it is more than 90% by weight, organic solvent resistance cannot be obtained.

The components (b) and (c) are both the total amount of the component (a) 10
1 to 50 parts by weight, preferably 3 to 30 parts by weight, more preferably 5 to 25 parts by weight, are added to 0 parts by weight. If it is less than 1 part by weight, there is a problem in compatibility with PC and PP, and if it is more than 50 parts by weight, it is not preferable in terms of reduction of elastic modulus or organic solvent resistance and economical efficiency. The blending ratio of the components (b) and (c) depends on the amount of the hydroxyl group in the component (b) and (c).
It can vary widely depending on the amount of carboxyl groups in the component. Generally, it is desirable that the compound be blended in such a manner that 1 mol of the hydroxyl group is 1 mol of the hydroxyl group.

3-4-3 Method for Producing Mixed Composition As a melt-kneading method for obtaining the resin composition according to the present invention, a kneading method generally used for thermoplastic resins can be applied. For example, after uniformly mixing the powdery or granular components together with the additives described in the paragraph 3-4-1- (5), if necessary, using a Henschel mixer, a ribbon blender, a V-type blender, or the like. It can be kneaded with a single-screw or multi-screw kneading extruder, a roll, a Banbury mixer, or the like. Depending on the situation, it is possible to melt-knead two or more specific components among the constituents of the present invention in advance, and then add the remaining components and melt-knead. The melt-kneaded composition can be granulated by using a granulator or a crusher for the purpose of facilitating the molding process.

3-4-4 Molding Processing of Resin Composition The molding method of the resin composition according to the present invention is not particularly limited, and molding methods generally used for thermoplastic resins, that is, injection molding, blow molding, extrusion. Molding, sheet molding, thermoforming, rotational molding, laminated molding, stamping and the like can be applied, but injection molding is most preferable.

 Hereinafter, the effects of the present invention will be described with reference to examples.

3-5 (Example) 3-5-1 Sample (1) Unmodified PC PC Iupilon S2000 manufactured by Mitsubishi Gas Chemical Company.

Viscosity average molecular weight 2.5 × 10 ⁴ .

(2) Unmodified PP Mitsubishi Yuka PP homopolymer Mitsubishi Horipro MA8. MFR value 0.7g / 10min measured at 230 ℃ (3) Modified PC sodium hydroxide 3.4kg is dissolved in water 42l and heated to 20 ℃ While keeping it, 6.6 kg of 2,2-bis (4-hydroxyphenyl) propane (= BPA) and 8 g of hydrosulfite were dissolved.

Add 28 l of methylene chloride to this and stir while
-258 g of hydroxyethylphenol were added, followed by bubbling 3.3 kg of phosgene in 60 minutes.

After the completion of blowing phosgene, the reaction solution was emulsified by vigorous stirring, and after emulsification, 8 g of triethylamine was added and stirring was continued for about 1 hour to polymerize.

The polymerization liquid is separated into an aqueous phase and an organic phase, the organic phase is neutralized with phosphoric acid, and then repeatedly washed with water until the pH of the washing liquid becomes neutral, and then 35 l of isopropanol is added to precipitate the polymer. Let The precipitate was filtered off and then vacuum dried to obtain a white powder of modified PC.

As a result of measuring the viscosity average molecular weight of this modified PC, 1.6 × 1
It was 0 ⁴ .

(4) Modified PP PP (Mitsubishi Polypro MA8) 100 parts by weight, maleic anhydride 3
Parts by weight were dry blended with a Henschel mixer. To this, 0.2 parts by weight of t-butyl peroxypivalate was added and kneaded at 240 ° C. with a 30 mmφ twin-screw kneader manufactured by Ikegai Tekko. The content of maleic anhydride residue after extracting the obtained composition with acetone was 1.3 × 10 ^-2 mol / 100 g.

3-5-2 Preparation of sample According to the blending ratio in Table 1, after a total of about 800 g of each component was dry blended, a multi-screw kneader EK-2X-1000 manufactured by Toseki Seimitsu Kogyo
At 260 ° C., a roller rotation speed of 20 rpm was preliminarily kneaded for 2 minutes, and then the rotor rotation speed was increased to 100 rpm, followed by kneading for another 5 minutes. Prior to the kneading, the inside of the kneader was depressurized to 10 Torr or less, and then nitrogen gas was introduced to completely replace the nitrogen.

 After the completion of kneading, the sample was crushed by a crusher to give a granule.

The granular sample was molded into a test piece for evaluation of flexural modulus, Izod impact strength, appearance and organic solvent resistance using an M40A-SJ type injection molding machine manufactured by Koki Seisakusho.

3-5-3 Measurement and evaluation method (1) Dispersion form A part of the molded product was cut out and the dispersion form of the disperse phase was observed with a HHS-2R scanning electron microscope manufactured by Hitachi Ltd.

(2) Bending elastic modulus In accordance with ISO R178-1974 Procedure 12 (JIS K7203), the value at 23 ° C was measured using an Instron tester.

(3) Izod impact strength According to the ISO R180-1969 (JIS K7110) notched Izod impact test method, the value at 23 ° C was measured using an Izod impact tester manufactured by Toyo Seiki Seisakusho.

(4) Organic solvent resistance Bergen's 1/4 ellipse method (SPE Journal, 667, 1962)
It measured according to. Specifically, a test piece with a thickness of 2 mm was fixed to a quarter elliptical jig with a long axis of 240 mm and a short axis of 80 mm, and the minimum strain at which cracks occurred when immersed in commercially available gasoline for 5 minutes It was calculated as the limit strain. At this time, those with no cracks are ◎ (extremely good), those with a critical strain of 1.5% or more are ○ (good), those with 1.0 to 1.5% are △ (normal), those with less than 1.0% are ×. It was evaluated as (poor).

(5) Appearance of Molded Product The appearance of a molded product of 65 × 65 × 2 mm was evaluated mainly on delamination. Those having no problem in practical use were evaluated as ◯, those requiring improvement were evaluated as Δ, and extremely defective were evaluated as ×.

3-5-4 Description of Examples As shown in Examples 1 to 3 in Table 1, by combining modified PC having a fatty acid hydroxyl group at the terminal and modified PP having a carboxyl group as a compatibilizing agent, PC Is significantly improved (refined) compared with Comparative Examples 1 and 2 in which these compatibilizing agents are not used together and Comparative Example 3 in which the compatibilizing agent is not used at all, and it is originally incompatible. PC and PP
A resin mixture composition having a high elastic modulus and excellent impact resistance and chemical resistance, which has improved compatibility with and has the characteristics of PC and PP, was obtained.

3-6 Effects of the Invention As described above, according to the present invention, the use of the novel compatibilizer makes it possible to obtain excellent mechanical properties (flexural modulus and impact resistance) of PC and excellent moldability and resistance to PP. It is possible to provide a thermoplastic resin composition having both organic solvent properties and excellent appearance of a molded product. As a result, as a so-called engineering plastic, a composition in which PC having excellent mechanical strength and PP having excellent moldability and solvent resistance are mixed, and one of the resins forming the dispersed phase is about several microns. It is possible to provide a composition having a physical dispersion which is not achieved by the conventional mixing method.

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Shigeo Yanada 2-12, Shinshu-cho, Toyonaka City, Osaka Prefecture Mitsubishi Gas Chemical Co., Ltd. Osaka Plant (72) Inventor Ken Ken Ohno 1 Toho-cho, Yokkaichi-shi, Mie Prefecture Address Mitsubishi Petrochemical Co., Ltd. Resin Research Laboratory (72) Inventor Yusuke Arashi 1 Toho-cho, Yokkaichi-shi, Mie Prefecture Mitsubishi Petrochemical Co., Ltd. Resin Research Laboratory

Claims (1)

[Claims] 1. A thermoplastic resin composition obtained by melt-kneading the following components (a), (b) and (c): (a) 10 to 90% by weight of unmodified polycarbonate and 90 to 10 of unmodified polypropylene. 1% to 50 parts by weight of modified polycarbonate having an aliphatic hydroxyl group at the end, (c) (a) to 100 parts by weight, (c) (a) to 100 parts by weight And 1 to 50 parts by weight of modified polypropylene having a carboxyl group.