JPS638982B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is made of ABS resin (ABS resin or MABS resin), vinyl chloride resin, and alkyl acrylate or alkyl methacrylate polymer, and is flame retardant and has excellent processability, impact resistance, and resin replacement ability in the molding machine. The resin composition, more specifically,
A copolymer obtained by adding an alkyl (meth)acrylate component during the copolymerization of vinyl cyanide and aromatic vinyl alkyl methacrylate in the presence of a diene rubbery polymer, and a vinyl chloride resin. It has excellent processability and impact resistance, and there is less adhesion of the molten resin to metal surfaces such as cylinders, screws, dies, nozzles, etc. of the molding machine that processes this resin composition, making it easy to replace the resin in the molding machine. This relates to a resin composition that has excellent properties in terms of thermal stability, as well as low adhesion of the molten resin, so there is almost no local retention of the resin, reducing thermal deterioration in the retained area. be. Among the various properties of synthetic resins, high flame retardant properties have become particularly desirable. The American UL standard is often used as an indicator of flame retardancy. Among the standards, resins with relatively high flame retardancy that are often used in fields such as injection molding and extrusion molding are additive-type resins that are made by adding flame retardants to easily flammable resins such as ABS resin. It is broadly divided into two types: what is commonly called a PVC blend type, and what is generally called a PVC blend type, which is a blend of easily flammable resin such as ABS and vinyl chloride resin. Of these two types, the vinyl chloride blend type accounts for a considerably larger proportion in general use, partly because it is economically advantageous. In injection molding, which is a commonly used molding method, this PVC blend type resin is processed at a temperature close to the decomposition temperature of the PVC resin. There is a drawback in terms of thermal stability. This thermal stability problem can be roughly divided into thermal deterioration at the nozzle of the molding machine or at the gate of the molded article, where the resin temperature is highest, and deterioration due to long-term thermal history due to partial retention in the molding machine. Several attempts have been proposed and implemented to improve this drawback of vinyl chloride blend type resins. One method is to use a vinyl chloride resin with a smaller molecular weight, but there is a decrease in practical mechanical strength, a decrease in thermal stability, etc., and there is a limit to the molecular weight of the vinyl chloride resin to be used. Another method is to add large amounts of plasticizers or lubricants, but these have drawbacks such as the additives bleeding onto the surface of the molded product, peeling phenomena appearing on the molded product, and reduced heat deformation resistance. . Another method is to copolymerize, graft polymerize, or pseudo-graft polymerize vinyl chloride with an unsaturated hydrocarbon compound such as ethylene or propylene, or an alkyl acrylate or alkyl methacrylate to lower the melt viscosity of the vinyl chloride portion or to improve the lubricating properties. There is also a method to improve workability, such as by adding
This processability improvement method can lengthen the time until thermal decomposition by Brabender plastography. Therefore, although it is effective as a method for improving the thermal deterioration of the nozzle or gate portion, it has not yet been able to improve the deterioration caused by long-term thermal history due to partial retention in the molding machine. As a result of intensive studies, the present inventors have found that adhesion to metal surfaces is likely to be caused by not only vinyl chloride resin but also ABS resin, and that the adhesion caused by ABS resin is particularly large at high temperatures. ABS is a polymer chain mainly composed of acrylate compounds or alkyl methacrylate compounds.
It has been found that allowing the resin to exist in close contact with the resin is effective in improving the thermal deterioration caused by the above-mentioned partial retention. It has excellent processability and impact resistance, and has low adhesion of molten resin to metal surfaces such as cylinders, screws, dies, nozzles, etc. of the molding machine, and has excellent resin replacement properties in the molding machine. ,
We have found a vinyl chloride blend type resin composition that has significantly less thermal deterioration due to partial retention of the resin. That is, the present invention provides a composition comprising 20 to 70% by weight of ABS resin or MABS resin [A] containing a methyl methacrylate component and 80 to 30% by weight of vinyl chloride resin [B].
Based on 100 parts by weight, 1 to 10 parts by weight of a polymer [C] containing one or more alkyl (meth)acrylate compounds as a main component is added to ABS resin using the above polybutadiene-based rubbery polymer. or
When manufacturing MABS resin, it is mixed in the form of latex particles, which improves impact properties and processability.
Contains a resin composition with excellent thermal stability and resin substitution properties. The details will be explained below. The content of resin component [A] is 30 to 65% by weight.
If it is less than 30% by weight, there will be a tendency for difficulties in processability to occur, and if it exceeds 65% by weight, it will be difficult to maintain flame retardancy. Polybutadiene-based rubbery polymers include polybutadiene or 50% by weight or more of polybutadiene and 50% by weight or less of monoolefin monomers that can be copolymerized with this, such as aromatic vinyl compounds such as styrene, methyl acrylate, ethyl acrylate, butyl acrylate. Alkyl acrylates such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate; copolymers with vinyl cyanide compounds such as acrylonitrile. Copolymer [C] is selected from alkyl acrylates such as methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, butyl acrylate, and cyclohexyl acrylate; and alkyl methacrylates such as ethyl methacrylate, 2-ethylhexyl methacrylate, and butyl methacrylate. By polymerizing 100 to 50% by weight of one or more monomers and 0 to 50% by weight of one or more monomers selected from aromatic vinyl compounds such as styrene and α-methylstyrene. It is a copolymer. Alkyl (meth)acrylate
If it is less than 50% by weight, the molten resin will stick to the metal surface so much that it will be difficult to obtain the effect of resin substitution.
This copolymer [C] consists of resin [A] and resin [B]
It is preferably 1 to 10 parts by weight, particularly 1.5 to 5 parts by weight, based on 100 parts by weight of the composition. If it is less than 1 part by weight, the molten resin will stick to the metal surface and the effect of resin replacement will not be obtained, and if it exceeds 10 parts by weight, the miscibility with vinyl chloride resin will be poor, and the molded product will not undergo heat deformation. This is not preferable because it also reduces performance. Copolymer [C] is the state of latex at the beginning, during, or at the end of graft polymerization when producing ABS or MABS resin [A] using a polybutadiene-based rubbery polymer. It is important to mix at According to the present invention, one of the features is that the cost can be made almost the same in terms of manufacturing process compared to conventional ABS resin. Vinyl chloride resin [B] is polyvinyl chloride or a copolymer of 90% by weight or more of vinyl chloride and 10% by weight or less of a monoolefin monomer that can be copolymerized therewith, such as vinyl acetate, vinylidene chloride, acrylonitrile, etc. The degree of polymerization is preferably from 300 to 1000, more preferably from 400 to 750, from the viewpoint of processability and impact resistance of the desired resin composition. The resin composition of the present invention is put to practical use with various additives added thereto, and as the stabilizer, tin-based stabilizers and lead-based stabilizers are preferred in terms of thermal stability. Next, examples of the present invention will be shown, but the present invention is not limited to the following examples. Examples and Comparative Examples Production of Polymer [C] Emulsion polymerization was carried out at 60°C based on the charging ratios shown in Table 1 to obtain Polymers [C]-1 and [C]-2.

[Table] Oxylate
ABS resin or MABS resin and copolymer [C]
Production of a mixture Emulsion polymerization was carried out at 60°C based on the charging ratio shown in Table 2 to obtain polymers [D]-1 to 4, ABS-.

[Table] Manufacturing of PVC Polyvinyl chloride resin powder (Kanevinyl S-500,
300 parts by weight of water was added to 100 parts by weight (manufactured by Kanebuchi Chemical Co., Ltd.), and then 6.2 parts by weight of butyl acrylate containing 0.02 parts by weight of benzoyl peroxide was added and the mixture was sufficiently impregnated and absorbed into the vinyl chloride resin at room temperature while stirring. at 85℃
Polymerization was carried out for 18 hours. Dehydrate the obtained polymer,
After washing with water, washing with methanol was performed to remove unreacted monomers, and then drying was performed. The grafting amount of butyl acrylate was 6.0 parts by weight based on 100 parts by weight of vinyl chloride resin. Add the additives shown in Table 3 per 100 parts by weight of a mixed resin composition of ABS resin or MABS resin and vinyl chloride resin, pelletize it using a 40 mm single screw extruder, and then mold it using a 5 oz injection molding machine. The results shown in Table 4 were obtained. [D]-5 is the second
In the table, a latex of Polymer [C]-1 (polymer solid content: 6 parts by weight) was added to a latex (polymer solid content: 100 parts by weight) after completing the polymerization of ABS-.

[Table] The vinyl chloride resin used is Kanevinyl S-500.
(=550).

[Table] As can be seen from the examples in this table, Brabender takes a long time to disassemble, is easy to clean after disassembly, is easy to replace with resin in the molding machine, and has a higher Izod impact value and higher flow value than the polymer. C] is greatly improved compared to the one without (Comparative Example 1). Comparative Example 2 used polymer [C] in an amount exceeding 10 parts by weight,
The Brabender decomposition time is long, and although it is easy to clean, has good resin replacement properties in the molding machine, and has good flow values, the heat distortion temperature decreases significantly. Comparative Example 3 uses vinyl chloride resin impregnated and polymerized with butyl acrylate, but the degree of improvement in the difficulty of cleaning the Brabender and the resin replacement property of the molding machine is smaller than in Examples 1 to 4, and thermal deformation is small. The temperature drop is large.

Claims (1)

[Claims] 1. A composition comprising 30 to 65% by weight of ABS resin or MABS resin [A] containing a methyl methacrylate component and 70 to 35% by weight of vinyl chloride resin [B]
Polymer [C] 1 to 10 containing one or more alkyl acrylate compounds or alkyl methacrylate compounds as a main component per 100 parts by weight
A flame-retardant resin composition consisting of [A], [B] and [C] obtained by mixing parts by weight in the form of latex particles during the production of the above-mentioned ABS resin or MABS resin.