JPH0530861B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention The present invention relates to a resin composition that has an excellent balance of impact resistance, processability, and heat resistance, and also has excellent impact resistance at low temperatures. Heat-resistant ABS resins, which are made by blending α-methylstyrene polymers or maleic anhydride copolymers with rubber-reinforced styrene resins, such as ABS resins, have been known for a long time (e.g., published by the Society of Polymer Science and Technology in 1971). 〃ABS resin〃) is widely used in automobile parts, electrical equipment parts, etc., but the heat resistance
ABS resin has the disadvantage of being prone to thermal decomposition during molding. Furthermore, as the field of use expands, compositions with even better heat resistance are required. In recent years, maleimide monomers with excellent heat resistance and thermal decomposition resistance have attracted attention, but maleimide copolymers are significantly inferior in impact resistance and processability. For this reason, compositions with improved impact resistance are produced by polymerizing maleimide with other vinyl compounds in the presence of a rubbery polymer, or by mixing a maleimide copolymer with a graft polymer of rubber and a vinyl compound. has been proposed, but it still has problems such as poor workability. (Tokukai Akira
57-167341, JP 58-206657, JP 59-
11322) On the other hand, compositions with improved processability by mixing a maleimide copolymer with a styrene-acrylonitrile copolymer have been proposed, but they still have problems such as poor impact resistance. There is. (JP 58-217535, JP 58-217537) As a result of research in view of the above-mentioned problems, the present inventors discovered that a maleimide monomer and a graft polymer having a specific intrinsic viscosity and Q value They discovered that this composition has excellent impact resistance, processability, and heat resistance, and filed a patent application earlier. The present inventors discovered not only the structure of the maleimide copolymer, but also the structure of the maleimide copolymer.
As a result of further intensive research into the composition and structure of graft polymers, we found that a composition made by mixing a specific graft polymer with a previously discovered specific copolymer was superior to the previous composition. The present invention was achieved by discovering that it has impact resistance, processability, and heat resistance, as well as excellent impact resistance at low temperatures. The present invention will be explained in detail below. Constituent composition of the invention Γ Graft polymer (A) Graft polymer (A) used in the present invention
is one or more monomer components selected from aromatic vinyl monomers, unsaturated nitrile monomers, (meth)acrylic acid ester monomers, and maleimide monomers. and a rubber-like polymer, wherein the weight average particle diameter of the graft rubber is 0.03 to 0.29 μm, the grafting rate is 20 to 70%, and the non-grafted polymer contained in the graft polymer is The intrinsic viscosity of the coalescence is
It is a graft polymer with a molecular weight of 0.3 to 1.0. In the present invention, a graft polymer having a specific value as described above is used, but it is difficult to bond (graft) the entire amount of the above monomer components to a rubbery polymer in graft polymerization. , which generally contains ungrafted polymers produced as by-products during graft polymerization. Aromatic vinyl monomers used as one of the monomer components include styrene, α-methylstyrene, α-chlorostyrene, p-t-butylstyrene, p-methylstyrene, O-chlorostyrene, and p-chlorostyrene. Examples include styrene, 2,5-dichlorostyrene, and 3,4-dichlorostyrene. Examples of the unsaturated nitrile monomer include acrylonitrile, methacrylonitrile, maleonitrile, and fumaronitrile. Examples of (meth)acrylic acid ester monomers include methyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, benzyl (meth)acrylate, hexyl (meth)acrylate, and (meth)acrylate. ) lauryl acrylate, (meth) 2-hydroxyethyl acrylate, (meth)
Examples include glycidyl acrylate and dimethylaminoethyl (meth)acrylate. Maleimide monomers include maleimide,
N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-hexylmaleimide, N-
Octylmaleimide, N-laurylmaleimide, N-cyclohexylmaleimide, N-2,
3 or 4-methylphenylmaleimide, N-
2,3 or 4-ethylmaleimide, N-2,
3 or 4-butylphenylmaleimide, N-
2,6-dimethylmaleimide, N-2,3 or 4-chlorophenylmaleimide, N-2,3
or 4-bromophenylmaleimide, N-
2,5-dichloromaleimide, N-3,4-dichloromaleimide, N-2,5-dibromomaleimide, N-3,4-dibromomaleimide, N
-2,4,6-trichloromaleimide, N-
2,4,6-tribromomaleimide, N-2,
3 or 4-hydroxyphenylmaleimide,
N-2,3- or 4-methoxyphenylmaleimide, N-2,3- or 4-carboxyphenylmaleimide, N-4-nitrophenylmaleimide, N-4-diphenylmaleimide, N-
1-naphthylphenylmaleimide, N-4-cyanophenylmaleimide, N-4-phenoxyphenylmaleimide, N-4-benzylphenylmaleimide, N-2-methyl-5chlorophenylmaleimide, N-2- Methoxy-5-chlorophenylmaleimide is exemplified, and one or more types thereof are used. Preference is given to N-substituted maleimides, especially N-phenylmaleimide. Examples of the rubbery polymer include diene rubbers such as polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer,
Ethylene-propylene rubber such as ethylene-propylene copolymer, ethylene-propylene-nonconjugated diene copolymer, chlorinated polyethylene, acrylic rubber, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, etc. Can be mentioned. Methods for obtaining the graft polymer (A) include known emulsion polymerization methods, suspension polymerization methods, bulk polymerization methods, solution polymerization methods, emulsion-suspension polymerization methods, bulk-suspension polymerization methods, and emulsion-bulk polymerization methods. etc. Regarding the structure of the graft polymer (A), the weight average particle diameter of the graft rubber is 0.03 to 0.29 μm, the grafting rate is 20 to 70%, and the intrinsic viscosity of the ungrafted polymer (dimethylformamide solution, 30°C) is 0.3 to 0.29 μm.
Limited to 1.0. Here, the weight average particle diameter of the graft rubber is
If it is less than 0.03 μm, not only will it not be possible to obtain a product with high impact strength, but also the melt fluidity will be significantly reduced, resulting in poor processability. On the other hand, even if the weight average particle diameter exceeds 0.29 μm, it is difficult to obtain a material with high impact strength. Furthermore, if the intrinsic viscosity of the ungrafted polymer is less than 0.3, high impact strength cannot be obtained;
If it is larger than 1.0, workability will deteriorate. In addition,
The gel content of the graft rubber is preferably 80% or more. In addition, the ratio of monomer component/rubber-like polymer of the graft polymer is 10 to 90/90 to 10.
(parts by weight) is preferred. Γ Copolymer (B) The copolymer (B) used in the present invention contains 1 to 60 parts by weight of the aforementioned maleimide monomer, an aromatic vinyl monomer, an unsaturated nitrile monomer, and It consists of 99 to 40 parts by weight of one or more monomer components selected from (meth)acrylic acid ester monomers. If the composition ratio is outside this range, the object of the present invention cannot be achieved. That is, the maleimide monomer is 1
If it is less than 60 parts by weight, a composition with high heat resistance cannot be obtained, whereas if it exceeds 60 parts by weight, not only the processability but also the impact strength is reduced. The maleimide monomer is produced by direct copolymerization of the maleimide monomer and the above various monomers, or by imidization of a copolymer of maleic anhydride and the above various monomers. be able to. Examples of polymerization methods include bulk polymerization, solution polymerization, bulk-suspension polymerization, suspension polymerization, and emulsion polymerization. In addition, during polymerization, if necessary, add 30 monomers that can be copolymerized with the above monomers.
Polymerization can also be carried out by adding less than part by weight. Furthermore, what is important in the present invention is that the intrinsic viscosity of the copolymer (B) (measured at 30°C in a dimethylformamide solution) is 0.4 to 1.3, and
Q value (weight average molecular weight/number average molecular weight) is 4.0
The following shall apply. If the intrinsic viscosity is less than 0.4, the mechanical strength will decrease, and if it exceeds 1.3, the processability will be significantly poor, which is not preferable. Moreover, when the Q value exceeds 4.0, the mechanical strength decreases. In view of the mechanical strength, processability, and ease of polymerization of the copolymer, it is particularly preferable that the intrinsic viscosity is 0.5 to 0.9 and the Q value is 1.5 to 3.5. As a method for obtaining a copolymer whose specificity and Q value fall within such ranges, there are changes in the type and amount of the polymerization catalyst and molecular weight modifier used in copolymerization, the method of their addition, the polymerization temperature, etc. It will be done. Note that the Q value can be determined by gel permeation chromatography. Γ composition ratio The composition of the present invention comprises the above-mentioned graft polymer (A)
and a copolymer (B), and there is no particular restriction on the composition ratio, but from the viewpoint of the balance of impact resistance, processability, and heat resistance, the graft polymer (A) is 10 to 80%
Parts by weight, preferably 90 to 20 parts by weight of copolymer (B). Γ Mixing The graft polymer (A) and copolymer (B) can be mixed using a known mixer such as a Banbury mixer, a single screw or twin screw extruder, or the like. They can also be mixed in the form of a latex and recovered as a composition. In addition, known additives such as stabilizers, antistatic agents, lubricants, dyes and pigments may be appropriately blended during mixing. In addition, other thermoplastic resins such as polycarbonate, polyester, polyamide, polyphenylene oxide, polyether ether ketone, polyether sulfon, polysulfon, polyoxymethylene, etc. may be added to the composition of the present invention as appropriate depending on the purpose of use. can be blended. Examples will be described below, but the present invention is not limited thereto. Note that all parts and percentages shown in Examples and Comparative Examples are based on weight unless otherwise specified. Examples and Comparative Examples - Manufacture of rubber latex BR-1 to 4, 6 to 8 Butadiene 100 parts Sodium dodecylbenzenesulfonate 0.8 parts t-Dodecyl mercaptan 0.05 parts Potassium persulfate 0.3 parts Deionized water 150 parts The above mixture was stirred using a stirrer. Pour into a stainless steel reactor and react at 70℃ for 25 hours to determine the average particle size.
A rubber latex BR-1 of 0.23μ was obtained. In addition, polymerization was carried out in the same manner as in the production of BR-1 except that sodium dodecylbenzenesulfonate was used in the amount shown in Table 1, and BR-2 to 4 and B
-6 to 8 were obtained. ●BR-5 Rubber latex BR-1 (solid content) 15 parts Butadiene 85 parts Sodium dodecylbenzenesulfonate 0.2 parts T-dodecyl mercaptan 0.05 parts Potassium persulfate 0.3 parts Deionized water 100 parts The above mixture was poured into a stainless steel reaction vessel equipped with a stirrer. After purging with nitrogen, the mixture was reacted at 70°C for 25 hours to obtain rubber latex BR-5 with an average particle size of 0.43μ. ●SBR-1~2 Except for using 100 parts of butadiene in 15 parts of styrene and 85 parts of butadiene, and the amount of sodium dodecylbenzenesulfonate shown in Table 1, BR-
Polymerization was carried out in the same manner as in the production of SER-1~
I got 2. ●NBR-1 to 3 BR-1 except that 100 parts of butadiene was replaced with 10 parts and 90 parts of acrylonitrile, and sodium dodecylbenzenesulfonate was used in the amount shown in Table 1.
Polymerization was carried out in the same manner as in the production of NBR-1 to NBR-3.
I got it. ●BA n-butyl acrylate 98 parts Triallyl cyanurate 2 parts Sodium dodecylbenzenesulfonate 3 parts Potassium persulfate 0.3 parts Deionized water 200 parts The above mixture was charged into a stainless steel reactor equipped with a stirrer, and after purging with nitrogen, the mixture was heated to 60°C. After polymerization for a period of time, the temperature was raised to 70°C and the mixture was reacted for 3 hours to obtain rubber latex BA.

[Table] -Production of graft polymer- BR-2 (solid content) 60 parts Potassium persulfate 0.3 parts Deionized water 100 parts The above mixture was charged into a stainless steel reactor equipped with a stirrer, and the temperature was raised to 65°C after purging with nitrogen. From that point on, the following monomer mixture and emulsifier aqueous solution were continuously added over 4 hours to carry out polymerization. Monomer mixture; 24 parts of styrene, 16 parts of acrylonitrile, 0.2 parts of t-dodecyl mercaptan, aqueous emulsifier solution; 1.0 part of sodium dodecylbenzenesulfonate, 20 parts of deionized water After the continuous addition was completed, the temperature was raised to 70°C and further aged for 2 hours. The reaction was completed. An emulsion of an antioxidant was added to the obtained graft polymer latex, and the mixture was coagulated with an aqueous magnesium sulfate solution to obtain a graft polymer A-2. In addition, graft polymer A was used except that the rubber, monomer, potassium persulfate, and t-dodecyl mercaptan listed in Table 2 were used, and the polymerization temperature was changed.
Polymerization was carried out in the same manner as in the production of -2 to obtain various graft polymers. However, for X-3, the entire monomer mixture was charged at once for polymerization.

【table】

[Table] - Production of copolymer - Sodium dodecylbenzenesulfonate 0.3 parts Potassium persulfate 0.25 parts Deionized water 300 parts The above mixture was placed in a stainless steel reaction vessel equipped with a stirrer, and after purging with nitrogen, the temperature was raised to 75°C. From that point on, the following monomer mixture and emulsifier aqueous solution were continuously added over 5 hours to carry out polymerization. Monomer mixture; N-phenylmaleimide 30 parts Styrene 58 parts t-dodecyl mercaptan 0.15 parts Emulsifier aqueous solution; Sodium dodecylbenzenesulfonate 1.2 parts Deionized water 20 parts After the continuous addition was completed, aging was further carried out for 2 hours to complete the reaction. Completed. The obtained copolymer latex was coagulated with an aqueous magnesium sulfate solution to form copolymer B-2.
I got it. In addition, polymerization was carried out in the same manner as in the production of copolymer B-2, except that the monomers listed in Table 3, potassium persulfate, and t-dodecyl mercaptan were used, and the polymerization temperature was changed. A copolymer was obtained. However, for Y-6, t-dodecylmercaptan was not added at the initial stage of the reaction at 65°C.
The monomer mixture and emulsifier aqueous solution were added continuously for 2 hours, at which point the remaining monomer mixture was added with t-
0.3 part of dodecyl mercaptan was added, and the reaction temperature was further raised to 75°C to carry out polymerization.

【table】

[Table] *2 Upper row: early stage, lower row: late stage Graft polymer obtained by the above method (A)
After melt-kneading and copolymer (B) using a Banbury mixer, test pieces were prepared at 250 to 300°C using an injection molding machine, and physical properties were measured. The results are shown in Tables 4 and 5.

【table】

[Table] Effects of the Invention Graft polymer (A) having a specific particle size, graft ratio, and intrinsic viscosity of the present invention, a specific amount of maleimide monomer, and a copolymer (B) having a specific intrinsic viscosity and Q value. ) has excellent impact resistance, processability, and heat resistance.

Claims (1)

[Claims] 1 One or more monomer components selected from aromatic vinyl monomers, unsaturated nitrile monomers, (meth)acrylic acid ester monomers, and maleimide monomers A graft polymer consisting of
70% and the intrinsic viscosity of the ungrafted polymer contained in the graft polymer is 0.3 to 1.0, 1 to 60 parts by weight of a maleimide monomer, and an aromatic vinyl monomer. 99 to 40 parts by weight of one or more monomer components selected from monomers, unsaturated nitrile monomers, and (meth)acrylic acid ester monomers, and the amount of these monomers A copolymer consisting of 0 to 30 parts by weight of a monomer component copolymerizable with a copolymer, having an intrinsic viscosity of 0.4 to 1.3, and a Q value (ratio of weight average molecular weight/number average molecular weight) of 4 or less. A resin composition consisting of (B).