JPS6223982B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a polyphenylene ether resin composition having improved physical properties. [Prior Art] Polyphenylene ether has excellent electrical properties and mechanical properties, and has a high heat distortion temperature, so it has attracted attention as an extremely useful engineering plastic material. However, since the melting temperature is high and there are problems with thermal stability at high temperatures, it is difficult to mold the material under melting conditions. As a method to improve the moldability of polyphenylene ether, attempts have been made to blend it with other resins. Among these, a well-balanced material is poly(2 - A mixture of 6-dimethyl-1,4-phenylene) ether and rubber-modified polystyrene. This composition is poly(2,6-dimethyl-
It has improved moldability and impact resistance compared to 1,4-phenylene) ether. The impact resistance improvement effect is regulated by the rubbery polymer content in the rubber-modified polystyrene used, and as the rubbery polymer content increases, impact resistance is expected to improve. However, as long as commercially available rubber-modified polystyrene is used, it is difficult to incorporate the desired rubbery polymer content into the composition to improve impact resistance. One possible method for increasing the rubbery polymer content in the above composition is to mechanically add and mix a rubbery polymer such as polybutadiene, but in this case, the rubbery polymer is added to the resin composition. It has the disadvantage that it is not homogeneously dispersed in the liquid, does not impart desired physical properties, and also significantly impairs the appearance. [Summary of the Invention] As a result of intensive research into methods for improving moldability and impact resistance without impairing the excellent performance of polyphenylene ether, the present inventors have found that the following b. It has been found that by using the modified polystyrene shown, the moldability and impact resistance of polyphenylene ether can be significantly improved. That is, the present invention comprises (a) 80 to 20% by weight of polyphenylene ether, (b) 2 to 20% by weight of a butadiene rubber elastomer based on the styrene monomer, and 40 to 100% by weight based on the elastomer. Provided is a polyphenylene ether resin composition containing 20 to 80% by weight of rubber-modified polystyrene obtained by polymerizing a styrenic monomer in the presence of a polymer having an average molecular weight of 200 to 1,500 and having isobutylene as a main component. It is something to do. When the rubber-modified polystyrene produced in this way is mixed with polyphenylene ether, the surprising effect is that there is no decrease in heat distortion temperature or tensile strength, which is conventionally observed when plasticizers such as liquid paraffin are added. Obtained. Although the reason for this is not clear, it is presumed that the low molecular weight polymer containing isobutylene as a main component improves the affinity between the rubbery polymer in the rubber-modified polystyrene and polyphenylene ether. [Specific Description] In addition to the most typical styrene, the styrenic monomer used in the present invention includes substituted styrene in which the nucleus and/or side chain is substituted with a lower alkyl group or a halogen, particularly chlorine. Examples include paramethylstyrene, α-methylstyrene, parachlorostyrene, and others. Although these styrene derivatives may occupy the entire amount of the styrenic monomer, it is generally preferable to limit the amount to about 30% by weight of the total monomer raw material. The butadiene rubber elastomer mixed with the styrene monomer is a rubbery polymer containing a butadiene monomer, such as polybutadiene or styrene-butadiene rubber, and is usually used after being dissolved in the styrene monomer. be done. The mixing and dissolving ratio is 2 to 20% by weight relative to the styrene monomer,
Preferably it is 5 to 15% by weight. Generally 2% by weight
If the amount is less than 20% by weight, the strength as rubber-modified polystyrene cannot be expressed, and if it is more than 20% by weight, it is virtually impossible to dissolve the rubbery polymer in the aromatic vinyl monomer. This creates problems in implementation. Furthermore, the low molecular weight polymer obtained mainly from isobutylene to be mixed with the above two components is a low molecular weight polymer obtained by polymerizing isobutylene, or isobutylene and monoolefin or diolefin, and has an average molecular weight of 200 to 1500, preferably 400 to 1000. It is a molecular weight polymer, and it can also be used after hydrogenation. If the average molecular weight of this low molecular weight polymer is smaller than 200, it is not practical because the resulting polymer will scatter during granulation or molding, reducing its effectiveness. The improvement effect is extremely small. Generally, this low molecular weight polymer is produced by low-polymerizing a mixed gas containing mainly isobutylene from the butane-butene fraction produced by essential oil gas or naphtha cracking using a Friedel-Crafts type catalyst. It is a copolymer made by reacting isobutylene with a small amount of butene, has fluidity at room temperature, and is generally used as a lubricant. In this case, even if liquid paraffin, dioctyl phthalate, etc., which are commonly used as lubricants, are used as a substitute for the low molecular weight polymer, no impact resistance improvement effect is observed. The low molecular weight polymer is preferably 40 to 100% by weight based on the butadiene rubber elastomer.
It is used in a quantity ratio of 50-80% by weight. When used in an amount less than 40% by weight, the effect of improving impact resistance is small, and even when used in an amount greater than 100% by weight, there is no longer any improvement effect, but rather mechanical properties such as tensile strength deteriorate. When polymerizing styrenic monomers in the presence of the three components mentioned above, the purpose can be achieved by simply carrying out thermal polymerization without using an initiator, but in order to facilitate polymerization, an initiator is used. It is preferable to do so. However, when using an initiator, initiators with low grafting properties, such as aliphatic diacyl peroxides such as lauroyl peroxide and octanoyl peroxide, or azo compounds such as azobisisobutyronitrile and azobiscyclohexanenitrile, etc. It is necessary to use a polymerization initiator. The low molecular weight polymer obtained mainly from the butadiene rubber elastomer and isoprene is dissolved in the styrene monomer, and bulk polymerization is carried out in the presence or absence of the low grafting initiator. Either the polymerization is carried out until the polymerization is completed, or the bulk polymerization is carried out until the particles (microgel) of the rubbery polymer portion are substantially uniformly dispersed in a size of 1 to 10 microns, and then the suspension polymerization is carried out. There are two ways to complete the polymerization: When polymerizing using an initiator in the above polymerization method, it is important to use an initiator with low grafting properties during bulk polymerization. Bulk polymerization is generally carried out at a polymerization temperature of about 40 to 120°C, preferably 60 to 100°C, and when suspension polymerization is carried out thereafter, the conversion rate of bulk polymerization is 15
Continue until ~40% by weight is reached, then move to suspension polymerization to about 40-180℃, preferably 80-160℃.
Continue the polymerization at a temperature of °C. In this case, an initiator that decomposes at the above temperature, such as tertiary-butyl peroxybenzoate, tertiary-butyl peroxylaurate, di-tertiary diperoxyphthalate and dicumyl peroxide, may be added. Polymerization is generally carried out in the presence of an inert glass, such as nitrogen gas, under a pressure of usually 0.5 to 10 kg/cm ² G. Polyphenylene ether can generally be represented by the following formula. Here, the substituents R each independently represent hydrogen, halogen, a hydrocarbon residue (especially a C ₁ to _{C 12} alkyl group), a halohydrocarbon residue (especially a C ₁ to _{C 12} haloalkyl group), or a hydrocarbon oxy group. (especially _{a 1} C to C ₁₂ alkyloxy group), or a halohydrocarbonoxy group (especially a C ₁ to _{C 12} haloalkyloxy group), in which at least two Preferably a carbon atom is present). The hydrocarbon or hydrocarbon moiety of these groups is preferably free of tertiary-α-hydrocarbons. m is the degree of substitution and is an integer up to 4. R and m of each repeating unit may be the same or different. n is the degree of polymerization and is usually at least 50. Polyphenylene ether and its production method itself are unrelated to the present invention;
Various documents, such as U.S. patent no.
Specifications such as No. 3257357 and No. 3306874 can be referred to. Polyphenylene ethers are usually produced by oxidative coupling of the corresponding phenol compounds, but depending on the position or type of substituents (see the general formula above) and the polymerization method, 1,4-bonds may be produced. Although other polyphenylene ethers and copolymers may be obtained, such polyphenylene ethers may also be covered by the present invention without departing from the spirit of the invention. Polyphenylene ethers suitable for use in the present invention include, for example, poly(2,6-dimethyl-
1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, poly(2-methyl-6-propyl-1,4-
phenylene) ether, poly(2,6-dipropyl-1,4-phenylene) ether, poly(2-
Ethyl-6-propyl-1,4-phenylene) ether, poly(2,6-dilauryl-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-phenylene) ether, poly(2, 6
-dimethoxy-1,4-phenylene)ether,
Poly(2,3,6-trimethyl-1,4-phenylene) ether, poly(2,3,5,6-tetrapropyl-1,4-phenylene) ether, poly(2,6-diethoxy-1,4) -phenylene)ether, poly(2-methoxy-6-ethoxy-
1,4-phenylene) ether, poly(2-ethyl-5-stearyloxy-1,4-phenylene) ether, poly(2,6-dichloro-1,4)
-phenylene) ether, poly(2,3-dimethyl-5-chloro-1,4-phenylene)ether, poly(2-methyl-6-phenyl-1,4-
phenylene) ether, poly(2,6-dibenzyl-1,4-phenylene) ether, poly(3-
Chlor-1,4-phenylene) ether, poly(3,5-diethyl-1,4-phenylene) ether, poly(3-ethoxy-1,4-phenylene) ether, poly(2-chloro-1,4-phenylene) ether phenylene) ether, poly(2,5-dibrome-
1,4-phenylene) ether and the like. These polyphenylene ethers can contain a variety of common auxiliary materials that resinous materials normally contain, such as stabilizers, plasticizers, fillers, colorants, and the like. Furthermore, other polymers such as polyamides, polyolefins, polystyrenes, etc. can also be added to the composition. The resin composition of the present invention can be produced by any practicable method. Examples of blending methods include the following methods. (1) Create a mixed solution of both polyphenylene ether and rubber-modified polystyrene resins. A homogeneous mixture of both resins can be recovered as a solid from this solution by means such as distilling off the solvent used or mixing with a substance that is compatible with the solvent used but is a non-solvent for both resins. Specifically, there is a method in which hot o-dichlorobenzene solutions of both resins are poured into methanol. (2) Both polyphenylene ether and rubber-modified polystyrene resins are kneaded under heat. For example, kneading is performed at 230 to 350°C using a plastomill, extruder, etc. Regarding the composition ratio of polyphenylene ether and rubber-modified polystyrene, the amount of rubber-modified polystyrene used is in the range of 20 to 80% by weight of the total weight of polyphenylene ether and rubber-modified polystyrene. [Example] The present invention will be specifically described below with reference to Examples. Note that all parts in the examples are parts by weight. Example 1 1 Production of polyphenylene ether: In a reactor equipped with a gas blowing tube, a reflux condenser, a thermometer and a stirrer, 100 parts of 2,6-dimethylphenol and cupric bromide-N-N-N were added.・1.5 parts of N-tetramethylethylenediamine 1:1 complex,
5 parts of n-dibutylamine, 350 parts of benzene, and 150 parts of methanol were added, and oxygen was blown into the mixture while stirring vigorously at 30°C. After 120 minutes, the resulting slurry polymer was filtered and washed with a solution of 350 parts of benzene, 150 parts of methanol, and 5 parts of hydrochloric acid until the red color of diphenoquinone disappeared. After further washing with methanol, 60℃
It was dried under reduced pressure overnight. Colorless poly(2.6-
Dimethyl-1,4-phenylene) ether is 95
Part was obtained. 2 Production of rubber-modified polystyrene: 94 parts of styrene monomer, 6 parts of butadiene rubber (Diene 35A manufactured by Asahi Kasei Corporation), polyisobutylene
HV-35 (manufactured by Nisseki Jushi Kagaku Co., Ltd., average molecular weight 750)
Dissolve 5 parts of lauroyl peroxide
Add 0.18 parts of tertiary butyl peroxybenzoate and 0.15 parts of tert-butyl peroxybenzoate, and polymerize in bulk at 70°C for 5 hours with stirring. Add this reaction solution to 100 parts of water containing 1 part of calcium phosphate, and further polymerize at 120°C for 3 hours. Suspension polymerization was carried out at ℃ for 2 hours. The bead-shaped polymer produced was washed with water and then dried at 60°C for a day and night to obtain 102 parts of rubber-modified polystyrene having an intrinsic viscosity of 0.18 (measured in toluene at 25°C). 3 Mixing of polyphenylene ether and rubber-modified polystyrene: Polyphenylene ether 50 obtained by the above method
50 parts of rubber-modified polystyrene and tris(nonylphenyl) phosphite as a stabilizer.
0.25 parts, 1,3,5-trimethyl-2,4,6
-Tris(3,5-ditertiarybutyl-4
-Hydroxybenzyl)benzene (0.25 part) was placed in a Brabender and kneaded at 250°C for 10 minutes.
After kneading, a predetermined test piece was produced using a press and its physical properties were measured. Table 1 shows the results. Comparative Examples 1 and 2 Rubber-modified polystyrene was manufactured and mixed in the same manner as in Example 1, except that liquid paraffin was used instead of the low molecular weight polymer containing isobutylene as the main component. The results are shown in Table 1. Examples 2 and 3 and Comparative Example 3 In the production of rubber-modified polystyrene, production and mixing were carried out in the same manner as in Example 1, except that the molecular weight of the low molecular weight polymer containing isobutylene as the main component was changed. The results are shown in Table 1. Example 4 Rubber-modified polystyrene was produced in the same manner as in Example 1 except that styrene-butadiene rubber was used instead of polybutadiene rubber.

【table】

[Table] The results are shown in Table 1. Example 4 In producing rubber-modified polystyrene, production and mixing were carried out in the same manner as in Example 1, except that styrene-butadiene rubber was used instead of polybutadiene rubber. The results are shown in Table 1. Example 5 and Comparative Examples 4, 5, 6 In the production of rubber-modified polystyrene, production and mixing were carried out in the same manner as in Example 1, except that the quantitative ratio of the low molecular weight polymer containing isobutylene as the main component was changed. Ta. The results are shown in Table 1.

Claims (1)

[Scope of Claims] 1 (a) 80 to 20% by weight of polyphenylene ether and (b) 2 to 20% by weight of butadiene rubber elastomer based on the styrene monomer and 40 to 100% by weight based on the elastomer. % of isobutylene as a main component and has an average molecular weight of 200 to 1,500. Nylene ether resin composition.