JPS6129982B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polycarbonate resin composition that is made by blending a styrene resin and an aromatic polycarbonate resin and has excellent impact resistance and moldability. Compositions of styrenic resin and aromatic polycarbonate resin are generally used to improve the heat resistance, impact resistance, and mechanical properties of the former, and to improve the moldability and impact resistance of the latter. Various methods are being considered. However, due to the large difference in compatibility and fluidity between the two, it is extremely difficult to maintain a high level of processability and impact resistance in a wide range of molding areas, and in this field it is difficult to effectively combine these properties. Developing resins with such properties has become an important issue. As an example of a composition of styrene resin and polycarbonate resin, high impact polystyrene (butadiene-styrene copolymer) is blended with polycarbonate resin (British Patent No. 854475).
No.), blending ABS resin (acrylonitrile-butadiene-styrene graft copolymer) (Japanese Patent Publication No. 38-15225), blending a polymer obtained by graft copolymerizing styrene and methyl methacrylate with a styrene-butadiene copolymer. (Tokuko Showa 39-
71), blending a polymer obtained by graft copolymerizing styrene, methyl methacrylate, and acrylonitrile to a styrene-butadiene copolymer (Japanese Patent Publication No. 11496/1973). However, these are mainly aimed at improving the processability (flowability) of polycarbonate resin, and are intended to significantly improve impact resistance while retaining the original properties of polycarbonate resin. isn't it. Furthermore, in the method of blending ABS resin with a high rubber content with polycarbonate resin (Japanese Patent Publication No. 48-12170), the mechanical properties of the polycarbonate resin are improved, but the fluidity is not improved. On the other hand, since polycarbonate resins and styrene resins do not have very good compatibility, uniform blending is a major technical challenge. It has long been discovered that impact resistance can be significantly increased if islands of styrene resin are uniformly dispersed in a sea of polycarbonate resin (Plastics Vol. 21, No. 11). However, if this metastable equilibrium state is disrupted, phase separation occurs, and at the same time, impact resistance is extremely reduced. This is due to the difference in compatibility and fluidity resulting from the inherent properties of both polymers. Therefore, in a wide temperature range, it is extremely difficult to simultaneously improve moldability by taking advantage of the characteristics of styrenic resins and impart impact resistance. In order to solve the above-mentioned difficulties, the inventors of the present invention have made extensive studies and have developed a rubber polymer latex that has large particle diameters and contains solvent (toluene) insoluble matter (gel), and has a rubber polymer that is mainly composed of styrene. Discovered the fact that a composition obtained by blending a styrene resin with a specific grafting ratio into a polycarbonate resin by graft copolymerizing monomers thereof has unexpectedly excellent impact resistance and moldability, The present invention was achieved based on this knowledge. That is, the present invention uses polycarbonate resin (A) 95 to 50
90 parts by weight and 15 to 60 parts by weight (calculated as solid content) of a rubbery polymer latex with an average particle size of 0.4 μm or more and 40 to 80% by weight insoluble in a solvent (toluene). Monomers of which % or more is styrene85
~40 parts by weight was graft-polymerized, and graft ratio (%) = amount of dimethylformamide insoluble portion (g) - amount of rubbery polymer (g) / amount of rubbery polymer (g) x 10
This is a highly impact resistant and highly processable polycarbonate resin composition comprising 5 to 50 parts by weight of a styrene resin (B) having a graft ratio defined as 0 to 50 to 120%. According to the present invention, it is possible to provide a thermoplastic resin composition mainly composed of a polycarbonate resin, which significantly improves the impact resistance of molded articles and the moldability over a wide temperature range. The rubbery polymers used in the present invention include polybutaene, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, polyisoprene, etc. Latex obtained by emulsion polymerization method or latex produced by re-emulsification method is used. Ru. In order to impart excellent impact resistance to the composition of the present invention, there are naturally limits to the properties of the rubbery polymer, that is, the particle size and gel content, and the graft copolymer based on the rubbery polymer It is necessary that the coalescence has a certain grafting ratio. In the production of styrenic resins, the average particle diameter of rubbery polymer latex is 0.4 μm (4000 Å).
It is necessary that it is above. The larger the average particle size, the higher the impact strength of the styrenic resin and composition, but when it exceeds 2 μm, the stability of the latex decreases, emulsion graft polymerization becomes somewhat difficult, and the molding processability of the composition decreases. Because it decreases,
A rubbery polymer latex having an average particle size of about 0.4 to 1.0 μm is preferred. If it is less than 0.4 μm, a composition with excellent impact resistance cannot be obtained in practice. 40-80% by weight of the rubbery polymer in the latex must be insoluble (gel) in the solvent (toluene). If the insoluble content is less than 40% by weight or more than 80% by weight, it becomes difficult to obtain satisfactory impact strength. 15 to 60 parts by weight (as solid content) of rubbery polymer latex with a monomer of which 90% by weight or more is styrene.
Add 85 to 40 parts by weight and carry out graft polymerization using a radical polymerization initiator. If the rubbery polymer content is less than 15 parts by weight, the impact resistance of the composition will not be improved sufficiently, and
If it exceeds 60 parts by weight, the styrene resin becomes rubbery, resulting in decreased compatibility with polycarbonate resin and impairing processability. The amount of rubbery polymer in the styrenic resin is preferably 30 to 50 parts by weight in order to stably exhibit the properties of the composition. Monomers other than styrene include α-methylstyrene, vinyltoluene, p-chlorostyrene,
One or more types of monomers copolymerizable with styrene such as styrene derivatives such as 2,4-dibromustyrene, methyl methacrylate, methyl acrylate, and acrylonitrile are used. Styrene is
If it is less than 90% by weight, the processability of the composition will deteriorate and the cost will increase, which is undesirable. To improve the impact resistance of the composition of the present invention,
Regarding styrene resin, the above-mentioned graft rate is
It should be between 50 and 120%. Graft rate is 50%
If it is less than 120% or more than 120%, it becomes difficult to obtain satisfactory impact strength. The polymerization method for producing the graft polymer is not particularly limited. Even if polymerization is started by adding the rubber-like polymer latex and the entire amount of the styrene-based monomer, the styrene-based monomer may be added continuously, in portions, or in part. After initiation, the remainder may be added continuously for polymerization. The most preferred method is to charge a portion of the monomer mainly composed of styrene, polymerize to a predetermined conversion rate of 60 to 90%, and then continuously add the remaining portion to complete the polymerization. Also, a batch type or a continuous type may be used. The polycarbonate resin used in the present invention is
It is an aromatic polycarbonate resin having an aromatic residue in the main chain. Generally, 2,2-bis(4-oxyphenyl) alkanes, bis(4-oxyphenyl) ethers, bis(4-oxyphenyl)
Polymers or copolymers made of bisphenols such as sulfone, sulfide, or sulfoxide are used, but depending on the purpose, halo-substituted bisphenols may also be used. The composition of the present invention is composed of polycarbonate resin 95-50
The amount is 5 to 50 parts by weight of the styrene resin. When the amount of styrene resin is less than 5 parts by weight, moldability is poor and the molding area becomes narrow. On the other hand, 50
If the amount exceeds 1 part by weight, moldability improves, but impact resistance and mechanical properties deteriorate, which is not preferable. In order to particularly satisfy the properties of the present composition, the amount of styrenic resin is preferably 10 to 50 parts by weight. As a method for producing the composition of the present invention, a general mixing method can be used, for example, a melt mixing method using a heating roll, a Banbury mixer, an extruder, etc. can be applied. The compositions of the present invention may contain various commonly used additives such as heat stabilizers, pigments, inorganic fillers, flame retardants, and the like. Next, the present invention will be explained in more detail with reference to Examples. Alternatively, physical properties were measured according to the following method. Izotsu impact strength ASTM D256 test method 1/4 inch, notched, measured at 23°C Fluidity (Q) Koka type flow tester working load 30Kg/cm ² , nozzle diameter 1 mm × 2 mm, measured at 250°C Heat distortion temperature ASTM D648 Test method, load 18.6Kg/cm ² Rockwell hardness ASTM D785 test method Elongation ASTM D638 test method Solvent insoluble content of rubbery polymer Dry rubbery polymer 1
g was accurately weighed, dissolved in 100 ml of toluene, left to stand at room temperature for 48 hours, the amount of insoluble matter was filtered through a 100-mesh mesh, and the solid matter in 20 ml of the solution was determined and calculated using the formula below. Insoluble content (%) = (Rubber weight before dissolution (g)) - 5 x (solid content in liquid (g)) / (rubber weight before dissolution (g)) x 10
0 Note that parts and percentages in Examples and Comparative Examples are based on weight. Example 1 Production of styrenic resin - Average particle size 6250 Å (solvent (toluene) insoluble content 68
%) polybutadiene latex 50 parts (solid content equivalent), 20 parts styrene, potassium rosinate 1.0 part, potassium hydroxide 0.1 part, sodium pyrophosphate 0.2 part, dextrose 0.3 part, ferrous sulfate 0.01 part, water 150 parts 70% after putting into a reactor with a stirrer and purging with nitrogen.
The temperature is raised to 0.degree. C., 0.2 parts of cumene hydroperoxide is added as a radical polymerization catalyst, and the polymerization reaction is carried out for 1 hour. After that, separately adjusted styrene 30
parts, potassium rosinate 1.5 parts, potassium hydroxide 0.1 parts
part, cumene hydroperoxide 0.2 parts, water 50 parts
The emulsion consisting of 1.0 parts is continuously added to the polymerization system over a period of 3 hours. Thereafter, the reaction was continued for another hour while maintaining the jacket temperature at 70°C to complete the polymerization.
The polymerization conversion rate was 98% using the above method. 2,6-di-t is added to the produced latex as an anti-aging agent.
-Add 1.0 part of butyl-p-cresol, and add sulfuric acid.
2.0 parts was added and coagulated by heating, filtered, washed with water, and dried to obtain powdered resin (a). The grafting rate of this resin was measured by the method described above and was found to be 83%. Example 2, Comparative Examples 1 to 3 The resin (a) obtained in Example 1 and polycarbonate resin (Iupilon S-3000, manufactured by Mitsubishi Gas Chemical) were mixed in an extruder (cylinder temperature 240°C) and the mixture shown in Table 1 was prepared. A granular composition of the proportions indicated was obtained. After drying this composition, various test pieces were molded using an injection molding machine (cylinder temperature: 250°C) and their physical properties were measured. The results are shown in Table 1. The heat distortion temperature and hardness of the composition vary depending on the ratio of styrene resin to polycarbonate resin, but are practically sufficient within the scope of the present invention. The elongation becomes extremely large as the proportion of styrenic resin increases, indicating that the tenacity improves. The Izot impact strength and fluidity are higher than that of polycarbonate resin alone, and it is sometimes found that the former is extremely superior. Example 3 The same procedure as in Example 1 was carried out except that the polybutadiene used in Example 1 was changed to 40 parts, and the continuously added styrene was changed to 40 parts. The polymerization conversion rate in this method was 97%, and the grafting rate of this resin (b) was 74%.
It was hot. Example 4, Comparative Examples 4 to 5 The resin (b) obtained in Example 3 and the polycarbonate resin (Iupilon S-3000) were treated under the same conditions as in Example 2, and the physical properties were measured. Table 2 shows the results. It can be seen that by mixing the styrene resin (b) described in Example 3 with the polycarbonate resin, the moldability (fluidity) and impact resistance of the polycarbonate resin are significantly improved. Comparative Examples 6 to 8 The same procedure as in Example 1 was carried out except that the polybutadiene used in Example 1 was changed to 10 parts, and the continuously added styrene was changed to 70 parts. The polymerization conversion rate of this method was 93%, and the grafting rate of this resin was 155%. This resin (C) and polycarbonate resin (Iupilon S-3000) are blended to form a composition,
Its physical properties were measured. As shown in Table 3, compositions outside the scope of the present invention have extremely poor impact resistance, resulting in brittle molded articles, giving unsatisfactory results in practical use. Comparative Examples 9 to 11 Resin (d) was obtained in the same manner as in Example 1 except that the polybutadiene of Example 1 was changed to 70 parts and the continuously added styrene was changed to 10 parts. The polymerization conversion rate was 97%, and the grafting rate of resin (d) was 35%. A composition was prepared in the same manner as in Example 2, and its physical properties were measured. The results are also shown in Table 3. This composition has extremely low fluidity, resulting in extremely poor surface condition of the molded product. Moreover, the range of fluctuation in the measured value of the Izot impact strength is large, and it can be seen that it is not practical as a molded product. Comparative Examples 12 and 13 Resin (e) was produced according to Example 3 using polybutadiene with an average particle diameter of 2300 Å (solvent (toluene) insoluble content: 75%). The polymerization conversion rate in this method was 95%, and the grafting rate of resin (e) was 100%. A composition was prepared in the same manner as in Example 2, and its physical properties were measured. Table 4 shows the results. The composition of the present invention (b- in Table 2) has better impact resistance and fluidity than polycarbonate resin.
5, the physical property balance is not good compared to b-6). Using the compositions of b-5 and Comparative Example 12, molding was performed by changing the cylinder temperature of an injection molding machine, and the Izot impact strength was measured. The results are shown in Table 5, and it can be seen that compared to Comparative Example 12, the composition of the present invention has less dependence on molding temperature and provides stable physical properties. Comparative Examples 14 and 15 The same procedure as in Example 1 was carried out except that the polybutadiene of Example 1 was used in 10 parts, the styrene added initially was 40 parts, and the styrene added continuously was 50 parts. The conversion rate in this method was 91%, and this resin
The grafting rate of (f) was 98%. A composition was prepared in the same manner as in Example 2, and its physical properties were measured. Table 6 shows the results. Comparative Examples 16 and 17 In Example 1, instead of the cumene hydroperoxide component, 0.8 parts of water-soluble potassium persulfate was used as a catalyst during polymerization. The polymerization conversion rate by this method was 93%, and the grafting rate of this resin (g) was 38%. A composition was prepared in the same manner as in Example 2, and its physical properties were measured. The results are also shown in Table 6.

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[Table] Comparative Example 18 In Example 1, the monomers charged together with the polybutadiene latex were 16 parts of styrene and 4 parts of acrylonitrile, and the monomers continuously added were styrene.
The same procedure as in Example 1 was carried out except that 24 parts of acrylonitrile and 6 parts of acrylonitrile were used. In this method, the polymerization conversion rate was 96%, and the grafting rate of the obtained resin was 78%. Thereafter, in the same manner as in Example 2, this resin (h) and a polycarbonate resin (Iupilon S-3000) were blended to prepare a composition, and the test results are shown in Table 7. The graft monomer is 80% styrene,
It can be seen that the fluidity is significantly reduced compared to Example 5 (100% styrene as the graft monomer). Example 5 A styrenic resin was prepared in the same manner as in Example 1, except that the polybutadiene of Example 1 was changed to 30 parts, the monomer to be added together was changed to 28 parts of styrene, and the monomer to be continuously added was changed to 42 parts of styrene. was manufactured. The polymerization conversion rate was 97% and the grafting rate was 101%. Table 7 shows the physical properties of the composition with polycarbonate resin in the same manner as in Example 2. Comparative Example 19 In Example 1, using polybutadiene with an average particle diameter of 2300 Å (solvent (toluene) insoluble content 75%), 30 parts of polybutadiene and the monomers to be charged together, 18 parts of styrene and 10 parts of acrylonitrile, were continuously added. The monomers are 27 parts of styrene and 15 parts of acrylonitrile (the graft monomer is 64 parts of styrene).
%) A styrenic resin was produced in the same manner as in Example 1 except for the following. The polymerization conversion rate was 95% and the grafting rate was 127%. Table 7 below shows the physical properties of the composition in the same manner as in Example 2.
However, compared to the compositions of the present invention (Example 2 a-2 and Example 5), the Izot impact strength is extremely lowered, which is not good. Example 6, Comparative Examples 20 to 22 A resin was obtained in the same manner as in Example 1, except that a polybutadiene latex with a different average particle diameter and solvent (toluene) insoluble content was used in Example 1, and a resin was obtained in the same manner as in Example 2. I conducted a test. Table 8 shows the graft ratio of the obtained resin and the physical properties of the composition of the resin and polycarbonate resin. When the average particle diameter of the polybutadiene latex is outside the range of the present invention, as in Comparative Example 20, the impact strength is significantly reduced. Furthermore, when the polybutadiene latex has a high solvent (toluene) insoluble content outside the range of the present invention, as in Comparative Example 22, the impact strength is significantly reduced. On the other hand, the compositions of Example 6 and Comparative Example 21 were molded at a cylinder temperature of 270°C in an injection molding machine, and the Izot impact strength was measured. Example 6 is
33Kg・cm/cm, Comparative Example 21 is 18Kg・cm/cm, and if the solvent (toluene) insoluble content of the polybutadiene latex is outside the scope of the present invention, the impact strength will decrease significantly, and if the insoluble content is further reduced, the impact strength will decrease. It can be seen that the molding temperature dependence is extremely large, which is preferable.

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[Table] Comparative Example 23 In Example 1, polybutadiene latex
Polymerization was carried out in the same manner as in Example 1 by adding 35 parts of styrene and 20 parts of styrene first, then changing the continuous addition of 45 parts of styrene to the addition time of 10 hours to obtain a styrene resin (l) with a grafting rate of 127%. ) was obtained. Compositions having the proportions shown in Table 9 were evaluated using the method of Example 2, and the results shown in the table were obtained. If the grafting ratio exceeds the range of the present invention, the impact strength will decrease, which is not preferable. Example 7 In Example 1, the solvent (toluene) insoluble matter was 45
A styrenic resin (m) with a graft ratio of 89% was obtained in the same manner as in Example 1 using polybutadiene latex with an average particle diameter of 6100 Å. Compositions having the proportions shown in Table 9 were evaluated using the method of Example 2, and the results shown in the table were obtained. Example 8 A grafting rate of 55% was obtained in the same manner as in Example 1 except that the emulsion application time in Example 1 was changed to 1 hour.
A styrene resin (n) was obtained. Compositions having the composition ratios shown in Table 9 were evaluated using the method of Example 2, and the results shown in the table were obtained.

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Claims (1)

[Scope of Claims] 1. 95 to 50 parts by weight of polycarbonate resin (A) and 15 to 15 parts by weight of a rubbery polymer latex having an average particle size of 0.4 μm or more and 40 to 80% by weight being insoluble in a solvent (toluene). In the presence of 60 parts by weight (calculated as solids), 90
Graft polymerization of 85 to 40 parts by weight of a monomer whose weight% or more is styrene is carried out, and the graft ratio (%) = amount of dimethylformamide insoluble portion (g) - amount of rubbery polymer (g) / amount of rubbery polymer (g) )×10
A highly impact resistant and highly processable polycarbonate resin composition comprising 5 to 50 parts by weight of a styrenic resin (B) having a graft ratio of 50 to 120%. 2 Styrenic resin (B) is graft-polymerized with 70 to 50 parts by weight of a styrenic monomer in the presence of 30 to 50 parts by weight of a rubbery polymer, and the composition is
A composition according to claim 1 containing 50 parts by weight.