JPH0125335B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermoplastic resin composition having excellent heat resistance, impact resistance, melt flowability, and weather resistance. Polyglutarimide is a resin with a high heat distortion temperature, but on the other hand, its use as a thermoplastic molding material has been limited due to poor mechanical properties such as impact strength and poor fluidity during melt molding. As a method for improving polyglutarimide resin for use as a resin for thermoplastic molding materials, JP-A-52-
As described in Publication No. 63989 (Rohm, & Haas), acrylonitrile/butadiene/styrene (ABS) copolymers, methyl methacrylate/butadiene/styrene (MBS) copolymers, or polybutyl acrylate Although a method of mixing alkyl acrylate rubber-based impact modifiers such as these is known, it is difficult to obtain sufficiently high impact strength simply by mixing these impact modifiers. In addition, impact modifiers based on diene rubbers such as ABS copolymers and MBS copolymers contain double bonds in the rubber, so they are susceptible to deterioration due to oxygen, ozone, ultraviolet rays, etc. Even if the impact strength of the polyglutarimide resin is increased by mixing these impact modifiers, it is not possible to obtain an impact resistant resin with excellent weather resistance. On the other hand, since acrylic rubber such as polybutyl acrylate rubber does not contain unsaturated bonds, it is expected that a polyglutarimide resin composition with excellent weather resistance can be obtained by mixing it as an impact modifier. The impact strength of the resulting resin composition is insufficient, and its practical value as a heat-resistant and impact-resistant resin is low. In this way, it is not possible to obtain a resin with sufficiently high impact strength by mixing only the above-mentioned impact modifier with polyglutarimide, so as a method to further improve impact strength, (1) polyglutarimide is mixed with butadiene-based rubber. Alternatively, a method of mixing both a multistage polymer based on alkyl acrylate rubber and polycarbonate (Japanese Patent Application Laid-open No. 80459/1983)
(2) A method of mixing two types of impact modifiers: a multistage polymer based on butadiene rubber and a multistage polymer based on alkyl acrylate rubber (Japanese Unexamined Patent Publication No. 152740/1983) was proposed. has been done.
However, although the above-mentioned method (1) increases the impact strength to some extent, since polycarbonate is an essential component, the fluidity deteriorates, making it unattractive as a thermoplastic molding resin. Furthermore, in the above method (2), the impact strength is not sufficiently increased, and since it contains an impact modifier based on butadiene rubber, the weather resistance is also poor, making it impossible to obtain a desirable resin composition. Therefore, the present inventors aimed to obtain a polyglutarimide resin composition that maintains the high heat distortion temperature of polyglutarimide, has excellent impact resistance and fluidity during melt molding, and has good weather resistance. As a result of intensive study, we found that ethylene-propylene-
By mixing a graft copolymer based on non-conjugated diene copolymer rubber with polyglutarimide, a thermoplastic resin composition with excellent heat resistance, impact resistance, melt flowability, and weather resistance can be obtained. This discovery led to the present invention. That is, the present invention comprises (A) polyglutarimide and
(B) Ethylene-propylene-nonconjugated diene copolymer rubber from an aromatic vinyl monomer, a (meth)acrylic acid ester monomer, and a vinyl cyanide monomer in the presence of 10 to 70 parts by weight. A graft copolymer obtained by polymerizing 90 to 30 parts by weight of at least one vinyl monomer selected from the group consisting of 10 to 90 parts by weight of (A) and 90 to 10 parts by weight of (B). , and (A) + (B) in a ratio of 100 parts by weight. The polyglutarimide (A) used in the present invention is a polymer or copolymer containing a cyclic imide unit represented by the following formula (). However, R ₁ , R ₂ and R ₃ in the formula each represent hydrogen or a substituted or unsubstituted alkyl group or aryl group having 1 to 20 carbon atoms. Any polyglutaramide with any chemical structure can be applied to the present invention as long as it contains the above-mentioned cyclic imide unit, but usually R ₁ and R ₂ in the above-mentioned cyclic imide unit are hydrogen or methyl groups. Generally used are those in which R ₃ is hydrogen, methyl group, ethyl group, propyl group, butyl group or phenyl group. The method for producing polyglutarimide is not particularly limited, but for example, polymethyl methacrylate described in JP-A-52-63989 is reacted with ammonia or a primary amine such as methylamine or ethylamine in an extruder. Methods that form glutarimide rings are useful. In the present invention, the (B) graft copolymer mixed with (A) polyglutarimide is an ethylene-propylene-nonconjugated diene copolymer rubber (hereinafter referred to as EPDM).
Aromatic vinyl monomers such as styrene and α-methylstyrene, (meth)acrylic acid ester monomers such as methyl methacrylate and methyl acrylate, and It is obtained by polymerizing at least one kind selected from vinyl cyanide monomers typified by acrylonitrile. EPDM here refers to ethylene/propylene (mole ratio) of 20/80 to 90/
10. The composition preferably has a non-conjugated diene content of 1 to 20 mol% and a Mooney viscosity of 20 to 100.
As the non-conjugated diene, cyclic dienes such as norbornenes and cyclopentadienes, and chain dienes such as 1,4-hexadiene are used. Among these non-conjugated dienes, 5-ethylidene-
2-norbornene, dicyclopentadiene and 1,4-hexadiene are commonly used. In the graft copolymer (B) used in the present invention, the monomer mixture (graft component) polymerized in the presence of EPDM has a composition of 0 to 90% by weight of aromatic vinyl monomer, (meth)acrylic acid, Preferably, the ester monomer content is in the range of 0 to 100% by weight and the vinyl cyanide monomer content is in the range of 0 to 40% by weight. If the composition of the graft component is within the above range, (A) polyglutarimide and (B) graft copolymer exhibit good compatibility, resulting in a resin with excellent impact resistance, heat resistance, fluidity, and weather resistance. A composition can be obtained. (B) The graft copolymer is a monomer or monomer mixture having the above composition in the presence of 10 to 70 parts by weight, preferably 15 to 60 parts by weight of EPDM, preferably 40 to 85 parts by weight. It is necessary that the composition consists of a polymerized part by weight. If EPDM is less than 10 parts by weight, the impact strength of the resin composition is insufficient, and if it exceeds 70 parts by weight, the compatibility between the graft copolymer and polyglutarimide will deteriorate.
This is not preferable because it becomes impossible to obtain a resin composition with excellent impact resistance. Although various methods have been proposed for producing EPDM-based graft copolymers, there are no particular limitations on the method for producing the graft copolymer (B) used in the present invention.
A two-step polymerization method in which the first step is solution preliminary graft polymerization described in Publication No. 24596, Japanese Patent Publication No. 18118-1987.
The solution polymerization method using a non-polymerizable solvent described in Japanese Patent Publication No. 14549-1983, the emulsion polymerization method described in Japanese Patent Publication No. 14549-1983, and the suspension polymerization method described in Japanese Patent Publication No. 32833-1983, etc. etc. can be manufactured. The blending ratio of the resin composition in the present invention is 10 to 90 parts by weight of (A) polyglutarimide, particularly preferably 40 to 90 parts by weight.
80 parts by weight and (B) 90 to 10 parts by weight, particularly preferably 60 to 20 parts by weight (provided that (A) + (B)
is 100 parts by weight). Only when mixed at a blending ratio within this range, a resin composition with excellent heat resistance, impact resistance, fluidity, and weather resistance can be obtained. If the composition is outside this range, the resulting resin composition will be poor in one or more of the heat resistance, impact resistance, and fluidity properties, making it impossible to obtain a desirable resin composition. The resin composition of the present invention comprises (A) polyglutarimide and
(B) In addition to the graft copolymer, by further mixing various (co)polymers and resins depending on the purpose, the physical property balance of heat resistance, impact resistance, and melt fluidity can be further improved. or other desirable properties. For example, impact strength and fluidity can be improved by mixing polystyrene, styrene/acrylonitrile copolymer (SAN resin), styrene/methyl methacrylate copolymer, styrene/methyl methacrylate/acrylonitrile copolymer, etc. Can be done. α―
Methylstyrene/acrylonitrile copolymer, α
- Methylstyrene/styrene/acrylonitrile copolymer, α-methylstyrene copolymer such as α-methylstyrene/methyl methacrylate/acrylonitrile copolymer, styrene/maleic anhydride copolymer, styrene/maleic anhydride/ A high heat distortion temperature is maintained by mixing maleic anhydride copolymers such as acrylonitrile copolymers, styrene/maleimide copolymers, and maleimide copolymers such as methyl methacrylate/maleimide copolymers. At the same time, impact strength and melt fluidity can be improved. Also, styrene/maleic anhydride/butadiene copolymer, styrene/maleic anhydride/acrylonitrile/butadiene copolymer, acrylonitrile/maleic anhydride/styrene copolymer (ABS resin), methyl methacrylate/butadiene/styrene based copolymer (MBS resin) and rubber reinforced polystyrene (HIPST resin)
By mixing rubber-modified copolymers such as, impact strength can be significantly improved while imparting desired properties. In addition, desirable properties can be imparted by mixing various resins in accordance with various purposes. In addition, the thermoplastic resin composition of the present invention may be added with antioxidants such as ordinary hindered phenol antioxidants, phosphorus antioxidants, and sulfur antioxidants to improve thermal stability, or may be used as a lubricant. It is also possible to further improve the fluidity by adding . Depending on the purpose, fibrous reinforcing agents such as glass fibers, inorganic fillers, colorants, and pigments can also be blended. In addition, the resin composition of the present invention includes tetrabromobisphenol A, decabromobiphenyl ether,
Flame retardation can be achieved by mixing a general halogenated organic compound flame retardant such as brominated polycarbonate with antimony oxide. There are no particular limitations on the method for producing the thermoplastic resin composition of the present invention, and for example, (A) polyglutarimide, (B) graft copolymer, and other polymers may be mixed in advance or without mixing. A method of supplying the materials to an extruder in a desired ratio and melt-mixing them is adopted. As explained above, the thermoplastic resin composition of the present invention has an excellent balance of heat resistance represented by heat distortion temperature, mechanical properties represented by impact resistance, and fluidity during melt molding. Because it has excellent weather resistance, it is expected to be applied to a variety of applications that take advantage of these characteristics. The present invention will be further explained below using reference examples and examples. In addition, in the examples, the heat distortion temperature is
ASTM D-648-56, Izotsu impact strength is
Measured according to ASTM D-256-56Method A. The melt viscosity was measured at a resin temperature of 260°C using a Koka type flow tester. Parts represent parts by weight. Reference Example 1 (Preparation of (A) polyglutarimide, (B) graft copolymer, and (C) vinyl copolymer) (A) Polyglutarimide Pellets of polymethyl methacrylate were added with ammonia, methylamine, or ethylamine. Charge the resin into an extruder, and while degassing the generated gas from the exhaust port attached to the extruder, the resin temperature is increased to 280°C.
Three types of polyglutarimides shown in Table 1 were prepared by extrusion at .degree.

[Table] (B) Graft copolymer EPDM: Mitsui EPT manufactured by Mitsui Petrochemical Industries, Ltd.
#4070 (iodine number: 24, Mooney viscosity: 65, non-conjugated diene component: 5-ethylidene-2-norbornene) and Mitsui EPT # 1045 (iodine number: 12, Mooney viscosity: 40, non-conjugated diene component: dicyclopentadiene) ), a monomer mixture was polymerized in the presence of EPDM with the composition shown in Table 2 to prepare graft copolymers (B-1 to B-6). For comparison, graft copolymers (B-7 and B-8) based on polybutadiene rubber and polybutyl acrylate rubber were similarly prepared.

【table】

[Table] (C) Vinyl copolymer Copolymer (C-1) with the following composition (wt%)
~(C-4) was prepared. Copolymer (C-1): Styrene ~/acrylonitrile = 70/30 Copolymer (C-2): Styrene/methyl methacrylate/acrylonitrile = 30/60/10 Copolymer (C-3): α- Methylstyrene/styrene/acrylonitrile = 70/10/20 Copolymer (C-4): Styrene/maleic anhydride = 78/22 Example 1 Polyglutarimide prepared in Reference Example 1 (A-
1 to A-3), graft copolymers (B-1 to B-
8) and copolymers (C-1 to C-4) in the proportions shown in Table 3, and the physical properties of test pieces obtained by injection molding were measured. Table 3 shows the results. Weather resistance was also evaluated by irradiating the notched 1/2 inch test piece with a Sunshine Weatherometer for 400 hours and comparing the Izot impact strength before and after irradiation. The results are also shown in Table 3.

【table】

[Table] As is clear from the results in Table 3, the compositions of the present invention (K-1 to K-12) have excellent heat resistance, melt flowability, impact resistance, and weather resistance in a well-balanced manner. The properties of K-1 to K- can be further improved by blending other vinyl copolymers (C).
12). On the other hand, when a graft copolymer based on polybutadiene is blended (K-13), the weather resistance is extremely poor and the melt fluidity is also insufficient. In addition, when a graft copolymer based on acrylic rubber is blended (K-14), the weather resistance is satisfactory, but the impact strength is extremely low, so it cannot be put into practical use.

Claims (1)

[Claims] 1. An aromatic vinyl monomer, a (meth)acrylic acid ester monomer and A graft copolymer obtained by polymerizing 90 to 30 parts by weight of at least one vinyl monomer selected from the group consisting of vinyl cyanide monomers, with 10 to 90 parts by weight of (A) and 90 to 90 parts by weight of (B). ) is 90~10
A thermoplastic resin composition comprising (A) + (B) in a proportion of 100 parts by weight.