JPH0242854B2 - - Google Patents

Description

[Detailed description of the invention]

"Industrial Application Field" The present invention relates to a heat-resistant resin composition containing as a main component a mixture of a resin composition containing N-phenylmaleimide and an ABS resin. "Conventional technology" Styrene-maleic anhydride copolymer (hereinafter referred to as
Described as SMA. ) is ABS resin, styrene.
It is known to have good compatibility with acrylonitrile copolymers (hereinafter referred to as AS resins), and to have a high heat distortion temperature (good heat resistance). Therefore, compositions made by blending SMA with ABS resin, AS resin, etc. have excellent heat resistance and give molded products with good solvent resistance, but they have poor stability at high temperatures, such as when heated to 230°C or higher. This causes foaming, weight loss, crosslinking, etc., so when used as a normal injection molding material, it has been difficult to obtain molded products with high commercial value. In order to improve the high-temperature stability of compositions made by blending such SMA with ABS resin, AS resin, etc., attempts have been made to incorporate phenol-based, amine-based, or phosphorus-based antioxidants, etc. However, no satisfactory results have been obtained in practice. "Problems to be Solved by the Invention" The present inventor has conducted extensive research in order to provide a heat-resistant resin composition with excellent high-temperature stability.
The present invention was achieved by discovering that the above-mentioned drawbacks can be overcome by imidizing maleic anhydride residues contained in SMA. "Means for Solving the Problems" The gist of the present invention is that 15 to 50 parts by weight of N-phenylmaleimide residues, 85 to 40 parts by weight of vinyl aromatic monomer residues, and co-organized with these. A copolymer comprising 0 to 30 parts by weight of polymerizable vinyl monomer residues such that the total amount thereof is 100 parts by weight.
(A) 10 to 90% by weight, 15 to 30 parts by weight of vinyl cyan monomer residues, 85 to 65 parts by weight of vinyl aromatic monomer residues, and vinyl monomer residues copolymerizable with these. 0 to 30 parts by weight,
A resin composition containing 90 to 10% by weight of copolymer (B) such that the total amount of these is 100 parts by weight, and a mixture of ABS resin (C) as the main component. A heat-resistant resin composition characterized by: The present invention will be explained in detail below. Copolymer (A) constituting the resin composition according to the present invention
15 to 50 parts by weight of N-phenylmaleimide residue,
Comprising 85 to 40 parts by weight of vinyl aromatic monomer residues and 0 to 30 parts by weight of vinyl monomer residues copolymerizable with these, such that the total amount of these is 100 parts by weight. means. This copolymer (A) is a resin component that imparts excellent high temperature stability and heat resistance to the resin composition according to the present invention. N-phenylmaleimide residue contained in the copolymer (A) in the present invention (residue refers to a unit formed by polymerizing, for example, an N-phenylmaleimide monomer in the copolymer. The same applies hereinafter) ) is imidized by reacting aniline with N-phenylmaleimide residues introduced by direct copolymerization or maleic anhydride residues obtained by copolymerizing maleic anhydride. It will be done. The vinyl aromatic monomer residue contained in the copolymer (A) is generally a styrene residue, but α-
Methylstyrene, t-butylstyrene, or o
- Examples include styrene derivative residues such as halostyrene such as chlorostyrene and p-chlorostyrene. The vinyl monomer residues copolymerizable with the above two components contained in the copolymer (A) include vinyl monomer residues having a polar group, such as maleic anhydride residues, methyl acrylate, and acrylic acid. Residues of acrylic esters such as ethyl, methyl methacrylate,
Examples include residues of methacrylic esters such as ethyl methacrylate. Copolymer (A) has 15 N-phenylmaleimide residues
~50 parts by weight, 85 to 40 parts by weight of vinyl aromatic monomer residues, and 0 to 30 parts by weight of these copolymerizable vinyl monomer residues (however, 20 parts by weight of maleic anhydride residues) It is preferable that the following is the case.)
The total amount is 100 parts by weight. The content of N-phenylmaleimide residues in the copolymer (A) must be 15 to 50 parts by weight. If the content is less than 15 parts by weight, the high temperature stability and heat resistance of the resin composition will not be improved sufficiently, and if it exceeds 50 parts by weight, the fluidity of the resin composition during molding will decrease. I don't like that. The content of vinyl aromatic monomer residues in the copolymer (A) must be 5 to 40 parts by weight. If it is outside this range, the copolymer will not have sufficient heat resistance and its compatibility with other resins will decrease, which is not preferable. The content of the vinyl monomer residue copolymerizable with the above two components in the copolymer (A) varies depending on the type of monomer selected, but it must be in the range of 0 to 30 parts by weight. It won't happen. In addition, when maleic anhydride is selected as the copolymerizable vinyl monomer of the two components, the maleic anhydride residue is preferably 20 parts by weight or less, particularly preferably 20 parts by weight or less, per 100 parts by weight of the copolymer (A). is preferably 15 parts by weight or less. This is because, if the content is outside these ranges, the high temperature stability of the resin composition may be impaired, or the heat resistance and compatibility may be reduced. Copolymer (A) can be produced by a conventionally known method. For example, (a), by mixing the monomers that are the constituent components of the copolymer (A) and directly using a method such as an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, or a bulk polymerization method. Method of copolymerization, (b)
First, a copolymer is produced by combining a vinyl aromatic monomer, maleic anhydride, and in some cases a monomer that can be copolymerized with each of these in predetermined amounts, and then this copolymer is reacted with aniline. Any method may be used, such as a method of imidizing maleic anhydride residues contained in the copolymer. The latter method (b) of imidizing maleic anhydride residues contained in the copolymer is preferred because the maleic anhydride monomer is easily available and inexpensive. Copolymer (B) constituting the resin composition according to the present invention
means 15 to 30 parts by weight of vinyl cyan monomer residues, 85 to 65 parts by weight of vinyl aromatic monomer residues, and 0 to 30 parts by weight of vinyl monomer residues copolymerizable with these, It refers to a product that contains these in a total amount of 100 parts by weight. This copolymer (B) functions to improve the fluidity of the resin composition according to the present invention during molding. This copolymer (B) is
It must be compatible with copolymer (A). Examples of the vinyl cyanide monomer residue contained in the copolymer (B) in the present invention include residues of acrylonitrile, methacrylonitrile, and the like. Copolymer (B)
Examples of the vinyl aromatic monomer residues contained in the copolymer (A) include the vinyl aromatic monomer residues exemplified above as constituent components of the copolymer (A). Vinyl monomer residues that can be copolymerized with the above two components contained in the copolymer (B) include residues of acrylic esters such as methyl acrylate and ethyl acrylate, methyl methacrylate, and ethyl methacrylate. Examples include residues of methacrylic acid esters. The copolymer (B) in the present invention includes 15 to 30 parts by weight of vinyl cyan monomer residues and vinyl aromatic monomer residues.
85 to 65 parts by weight, and 0 to 30 parts by weight of vinyl monomer residue copolymerizable with these, the total amount of which is
100 parts by weight. When the composition of the copolymer (B) is within this range, the copolymer
It is preferable because it has good compatibility with (A) and the resulting resin composition of copolymer (A) and copolymer (B) in the present invention is transparent. If the composition of the copolymer (B) is outside the above range, the compatibility with the copolymer (A) will decrease and the physical properties of the resin composition according to the present invention will deteriorate, which is not preferable. Copolymer (B) can be produced by a conventionally known method. For example, the method may be appropriately selected from batch or continuous emulsion polymerization methods, suspension polymerization methods, solution polymerization methods, bulk polymerization methods, etc., which are known as AS resin manufacturing techniques. Further, the copolymer (B) can be produced by a polyblend method, which is carried out continuously with the production of the copolymer (A). In this case, the maleic anhydride residue is simultaneously imidized in the process of producing the copolymer (B). The resin composition in the present invention contains a copolymer (A) and a copolymer (B). The content ratio of copolymer (A) and copolymer (B) is such that the content is in the range of 10 to 90% by weight of copolymer (A) and 90 to 10% by weight of copolymer (B). selected. If the copolymer (A) is less than 10% by weight, the heat resistance of the resin composition according to the present invention will not be sufficient, and if it is 90% by weight or more, solvent resistance, fluidity during molding, etc. will deteriorate. Therefore, it is not desirable. In the present invention, ABS resin (C) refers to a continuous phase of a copolymer mainly composed of acrylonitrile, styrene, and their derivatives, conventionally known as acrylonitrile-butadiene-styrene resin, and polybutadiene, styrene-butadiene. A synthetic resin consisting of a phase in which rubber, acrylonitrile-butadiene rubber, etc. are dispersed. this
ABS resin (C) can be produced by a graft polymerization method, a blend method, or a graft polymerization-blend method. The ABS resin (C) in the present invention functions to improve the impact resistance and significantly improve the impact strength of the resin composition according to the present invention. The mixing ratio of the ABS resin (C) is preferably selected within a range that improves the impact resistance of the resin composition according to the present invention. As explained above, the resin composition according to the present invention includes a resin composition of a copolymer (A) and a copolymer (B),
The main component is a mixture with ABS resin (C). In order to obtain the resin composition according to the present invention containing the copolymer (A), the copolymer (B) and the ABS resin (C), a commonly known mixing and kneading method may be used. For example, predetermined amounts of three types of resin in the form of powder, beads, or pellets are weighed and mixed, and the resulting mixture is melt-kneaded, or two types of resin are mixed in advance using a polyblend or melt-kneading method. Keep it
A predetermined amount of premixed materials may be weighed and dry blended or melt kneaded. When melt-kneading, an extruder such as a single-screw extruder or a twin-screw extruder, or a kneader such as a Banbury mixer, a pressure kneader, or a two-roll kneader may be used. The resin composition thus produced has good stability at high temperatures, heat resistance, impact resistance, and physical strength. Stability at high temperatures can be determined by placing a test piece in a gear oven tester (JIS K7212) and heating it with hot air to determine the weight loss of the test piece and the presence or absence of air bubbles in the test piece. The resin composition according to the present invention is
It is preferable that the weight loss is less than 1.5% by weight when heated with hot air at 270° C. for 1 hour, and the test piece does not produce bubbles even when heated with hot air at 280° C. for 1 hour. The resin composition according to the present invention further includes JIS
Vikatsuto softening point measured according to K6870 is 110
The above, the Izotsu impact strength measured in accordance with JIS K6871 is 6.0Kg・cm/cm or more, and the JIS
Tensile strength measured according to K6871 is 400Kg/
It is preferable to set it to cm2 ^or more. The resin composition according to the present invention can be used as a raw material for manufacturing molded products as it is. Furthermore, impact resistance can be improved by blending other resins, such as ABS resin and AS resin. moreover,
Reinforcing agents such as glass fiber, carbon fiber, talc, and calcium carbonate, fillers, and lubricants of types and amounts that do not affect the properties of the resin, mold release agents, coloring agents, ultraviolet absorbers, light stability stabilizers, and heat resistance. Other additives such as stabilizers and flame retardants can be included. The resin composition according to the present invention can be produced by various processing methods such as injection molding, extrusion molding, and compression molding.
It can be used in applications requiring excellent heat resistance, high temperature stability, and impact resistance. "Effects of the Invention" The present invention has been described above, and has particularly remarkable effects as described below, and its industrial utility value is extremely large. (1) The resin composition according to the present invention does not cause foaming, weight loss, crosslinking, etc. at the molding temperature, and exhibits excellent high-temperature stability, and the molded product does not become foamed during molding, so it can be molded with an excellent appearance. You can get the goods. (2) The resin composition according to the present invention has good compatibility among the three components of copolymer (A), copolymer (B), and ABS resin (C), and has physical properties such as impact resistance of the resin composition. is excellent. (3) The resin composition according to the present invention has good physical strength, heat resistance, solvent resistance, and fluidity during molding, and has an excellent balance of physical properties among these properties. (4) Since the resin composition according to the present invention has excellent compatibility with other thermoplastic resins, it can be kneaded and mixed with other thermoplastic resins to produce a different type of resin composition with excellent heat resistance. It can be provided to "Examples" Next, the present invention will be specifically explained based on Examples and Comparative Examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.
In addition, "parts" in the following examples represent "parts by weight." Production example 1 A 21 autoclave equipped with a stirring blade, a raw material auxiliary addition device, and a nitrogen gas supply port was charged with 300 g of styrene, and while stirring and replacing nitrogen gas, the autoclave was heated from the outside to raise the internal temperature to 118. . In this polymerization system, 300 g of styrene and 100 g of maleic anhydride are added.
The polymerization reaction was continued in bulk at 118° C. while continuously adding a monomer mixture consisting of 100 g at a constant rate over 4 hours. At the completion of the continuous addition, the contents of the autoclave have a substantially maleic anhydride residue content of 25
The syrup consisted of 400 g of SMA and 300 g of styrene. To this polymerization system, 105 g of acrylonitrile, t-
0.3 g of dodecyl mercaptan was added and stirred.
Next, 720 g of water and 20 g of a suspending agent (2% aqueous solution of polyvinyl alcohol copolymer) were added to suspend the syrup in water. Then, 105 g of aniline was added to this suspension polymerization system.
3 g of triethylamine was added when the internal temperature was 80°C. Furthermore, azobisisobutyronitrile (hereinafter referred to as
Abbreviated as AIBN. ) was added thereto, and the temperature was raised to 120°C for 2 hours at 80°C and maintained at this temperature for 3 hours to continue the polymerization reaction in a suspension system. After the polymerization reaction was completed, the temperature inside the autoclave was rapidly cooled to obtain a bead-like polymer. The obtained bead-like polymer was melt-kneaded using a vented extruder and pelletized while removing volatile components. As a result of compositional analysis of the pellet, 70 mol% of maleic anhydride residues in SMA
Copolymer (A) in which is converted into N-phenylmaleimide
and AS with acrylonitrile residue content of 25% by weight
It was a resin composition containing a copolymer (B) which is a resin. Production Example 2 In the same 21 autoclave as used in Production Example 1,
270 g of styrene was charged, and the internal temperature was raised to 120° C. while stirring and purging with nitrogen gas. A monomer mixture consisting of 300 g of styrene and 130 g of maleic anhydride was continuously added to this polymerization system at a constant rate over 3 hours and 40 minutes, and the polymerization reaction was continued in bulk at 120°C. The contents of the autoclave at the completion of the continuous addition were essentially 30% by weight of maleic anhydride residues.
The syrup consisted of 430g of SMA and 270g of styrene. Next, in this polymerization system, a polymerization reaction in a suspension system was continued in the same manner as in Production Example 1 except that 135 g of aniline and 4 g of triethylamine were used in the example described in Production Example 1, and a bead-like polymer was obtained. I got it.
This bead-like polymer was pelletized in the same manner as in Production Example 1. The composition of the obtained pellets was a copolymer (A) in which 72 mol% of the maleic anhydride residues of SMA were converted into N-phenylmaleimide, and an AS resin in which the content of acrylonitrile residues was 26% by weight. It was a resin composition containing the aggregate (B). Production Example 3 In the example described in Production Example 2, except that aniline and triethylamine were not added, bulk polymerization reaction and suspension system polymerization reaction were carried out in the same manner as in the same example to obtain bead-like polymerization. A polymer was obtained, and this bead-like polymer was pelletized using an extruder in the same manner. The composition of the pellets obtained was a mixture of 59 parts by weight of SMA containing 30% by weight of maleic anhydride residues and 41 parts by weight of AS resin containing 26% by weight of acrylonitrile residues. Examples 1 to 6, Comparative Examples 1 to 2 ABS resin (a graft copolymer produced by emulsion polymerization method) was added to the resin composition produced by the method described in Production Example 1, Production Example 2, and Production Example 3. Styrene content
49% by weight, acrylonitrile content 18% by weight, polybutadiene content 33% by weight), and AS resin (Mitsubishi Monsanto Chemical Co., Ltd., SAN-C) in the proportions (parts) listed in Table 1 were weighed and mixed in a blender. This blend was melt-kneaded using a vented extruder, extruded while removing volatile components, and pelletized. These pellets were made into test pieces for measuring physical properties by injection molding, and the tensile strength, Izot impact strength, Vicat softening point, and melt flow rate were measured.
A test (foaming start temperature, weight loss of 270°C) was conducted. The results are shown in Table 1.

【table】

[Table] From Table 1, the following becomes clear. (1) The resin composition according to the present invention has an optimized composition of the copolymer (A), so it has a high foaming initiation temperature, less weight loss at 270°C, and therefore has excellent high-temperature stability. (See Examples 1 to 6).
Further, in Examples 1 to 4 and Example 6, the Vicat softening point is 110°C or higher, and the heat resistance is particularly good. On the other hand, resin compositions that do not contain N-phenylmaleimide residues have poor high temperature stability or heat resistance (see Comparative Examples 1 and 2). (2) The resin composition according to the present invention has good compatibility between the copolymer (A), the copolymer (B), and the ABS resin (C), and has excellent impact resistance (Example 1 to 6). In Examples 1 to 5, the Izot impact strength is 6.0 Kg·cm/cm or more, and the impact resistance is particularly good. (3) The resin composition according to the present invention has an excellent balance of physical properties (see Examples 1 to 6). Example 1~
In No. 6, the tensile strength is 400 Kg/cm ² or more, which is good.

Claims (1)

[Claims] 1 15 to 50 parts by weight of N-phenylmaleimide residue,
A copolymer comprising 85 to 40 parts by weight of vinyl aromatic monomer residues and 0 to 30 parts by weight of vinyl monomer residues copolymerizable with these, such that the total amount of these is 100 parts by weight. 10 to 90% by weight of polymer (A), 15 to 30 parts by weight of vinyl cyan monomer residue, 85 to 65 parts by weight of vinyl aromatic monomer residue, and vinyl monomer copolymerizable with these. 0 to 30 parts by weight of residue,
A resin composition containing 90 to 10% by weight of copolymer (B) such that the total amount of these is 100 parts by weight, and a mixture of ABS resin (C) as the main component. A heat-resistant resin composition characterized by: 2. The heat-resistant resin composition according to claim 1, wherein the vinyl aromatic monomer is styrene. 3. The heat-resistant resin composition according to claim 1, wherein the vinyl cyan monomer is acrylonitrile. 4 Weight loss when heated with hot air at 270℃ for 1 hour is 1.5
% by weight, and does not foam even when heated with hot air at 280° C. for 1 hour. 5. The heat-resistant resin composition according to claim 1, which has a tensile strength of 400 Kg/cm ² or more as measured in accordance with JIS K6871. 6. The heat-resistant resin composition according to claim 1, which has a Vikato softening point of 110° C. or higher as measured in accordance with JIS K6870. 7. The heat-resistant resin composition according to claim 1, wherein the Izot impact strength measured in accordance with JIS K6871 is 6.0 Kg·cm/cm or more.