JPS585356A - Novel resin composition - Google Patents

Abstract

PURPOSE:To provide a compsn. having improved processability without lowering heat distortion temperature, by blending an ethylene/unsaturated carboxylic acid ester copolymer with a thermoplastic styrene elastomer-contg. polyphenylene oxide resin compsn. CONSTITUTION:0.5-25pts.wt. ethylene/unsaturated carboxylate ester copolymer such as an ethylene/ethyl acrylate copolymer and 0.5-25wt% thermoplastic styrene elastomer composed of terminal polystyrene block and central (hydrogenated) diene rubber block, are blended with 100pts.wt. polyphenylene oxide resin alone or as a mixture with polystyrene resin to obtain the titled resin compsn. EFFECT:Moldings having excellent resistance to impact and chemicals and surface appearance can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an improved resin composition, particularly a polyphenylene oxide resin composition containing a styrenic thermoplastic elastomer, which further contains an ethylenically unsaturated carboxylic acid ester copolymer. The present invention relates to a polyphenylene oxide resin composition in which the processability of the composition is improved without lowering the heat distortion temperature, and the impact resistance and chemical resistance are significantly improved.

Polyphenylene oxide resin is a thermoplastic resin with excellent physical properties such as mechanical properties, electrical properties, chemical resistance, heat resistance, hot water resistance, flame resistance, and dimensional stability. It has disadvantages of poor workability due to its high temperature and relatively poor impact resistance.

A composite of polyphenylene oxide resin and polystyrene resin is known as a method for improving molding processability by lowering the melt viscosity while maintaining the excellent physical properties of polyphenylene oxide resin (for example, U.S. Pat. No. 33
No. 83485 and Japanese Patent Publication No. 43-17812) impart practical processability, but the excellent properties inherent to polyphenylene oxide resins such as heat resistance, flame resistance, and chemical resistance are likely to be lost. In addition, the impact resistance of polyphenylene oxide resin, which is slightly inferior, cannot be improved much even by combining polystyrene resin, so polystyrene resin modified with butadiene rubber or IPDI rubber is used.
Furthermore, it is also known to improve the impact resistance by mixing a styrene-based thermoplastic elastomer with composition #C. Although this method simultaneously improves chemical resistance, it tends to increase melt viscosity, resulting in a drastic reduction in processability and surface appearance, which is undesirable in many molding applications. .

A method has also been proposed in which the melt viscosity of a polyphenylene oxide resin composition is lowered to improve melt flow and improve processability. Generally, for the purpose of improving processability, a method of adding a relatively low molecular weight compound such as a plasticizing agent or a lubricant, and a method of blending a different type of high molecular weight resin into the resin composition are used. However, in the former case, desirable properties such as heat distortion temperature decrease, and in the latter case, a resin that is not compatible with the polyphenylene oxide resin compound is used, so the resin easily peels off from the surface during molding. The disadvantage is that not only the appearance deteriorates but also the mechanical properties are significantly deteriorated. In addition, when a resin with poor compatibility is mixed into a composition, there is a method of increasing the compatibility by using a chemical method such as graft polymerization or copolymerization of the blended resin with the component resin of the composition. Although this method can improve mechanical properties, it is difficult to maintain or improve processability.

The present inventors have developed a method of maintaining or lowering the melt viscosity of a poly(7-functional ethylene oxide) resin composition without lowering the heat distortion temperature, thereby improving impact resistance and chemical resistance without impairing moldability. As a result of intensive research into molding materials that can produce molded products with improved surface appearance, etc., we have arrived at the basic idea.

That is, the present invention provides (a) polyphenylene oxide resin alone, or (b)
(e) a poly-7-ethylene oxide resin combined with a polystyrene resin; (e) an ethylenically unsaturated carboxylic acid ester copolymer; (a styrenic thermoplastic elastomer comprising both polystyrene terminal blocks and a diene rubber central block; a styrenic thermoplastic elastomer hydrogenated to
The present invention provides a resin composition characterized in that 0) and (d) are each blended in an amount of 0.5 to 25% by weight.

The improved resin composition provided by the present invention does not increase or decrease the melt viscosity while maintaining the heat distortion temperature, and also significantly improves the impact resistance and chemical resistance of molded products, The surface appearance of the molded product is also excellent without impairing other mechanical properties.

The above improvement is a novel effect that could not be expected from the prior art for the following reasons. That is, the method of blending a rubbery polymer that has been conventionally used for the purpose of improving the impact resistance and chemical resistance of polyphenylene oxide resin compositions is accompanied by a significant increase in melt viscosity. Furthermore, if a beautifying agent or lubricant is added for the purpose of improving the fluidity of the composition, the heat deformation temperature and mechanical properties will be lowered, and incompatible resins will be blended in amounts that will improve the fluidity. If the mixture is mixed to a certain level, delamination will occur from the surface of the molded article, and the mechanical properties will also deteriorate severely. In this way, modification of resin compositions generally involves contradictory changes at the same time, and usually focuses on the effect to be improved and sacrifices the properties that deteriorate, or minimizes the deterioration of the sacrificed properties. As a result of limiting the blending amount of the modifier, no significant improvement effect could be expected.

However, the present invention #c surprisingly achieves the contradictory modification of maintaining or lowering the melt viscosity to improve impact resistance and maintain the heat distortion temperature at the same time. The surface appearance is also relatively good and no delamination occurs, which was completely unexpected from the prior art. Furthermore, the impact strength of the composition of the present invention remains extremely high even at low temperatures. This tendency was particularly clearly observed when the ball was hit by a falling ball (Km). In addition, the composition of the present invention was confirmed to have a remarkable improvement effect in the chemical resistance test. The relationship between comparative examples and examples described later shows that this is due to the combination of K styrene-based thermoplastic elastomer (oxide resin (or combination thereof with polystyrene) and ethylene-unsaturated carbonaceous ester copolymer). is also clear. That is, in a composition containing only a styrenic thermoplastic ethestomer, the impact resistance is improved, but the melt viscosity is increased and the surface appearance of the molded product is also deteriorated.

However, when a styrenic thermoplastic elastomer is used in combination with an ethylenically unsaturated carboxylic acid ester copolymer, not only can a greater impact resistance be improved than when a styrenic thermoplastic elastomer is used alone, but also the melt viscosity can be significantly reduced. Decrease. Furthermore, the amount of styrenic thermoplastic elastomer required to obtain the same improvement in isot impact strength is higher than that of the ethylene-unsaturated carboxylic acid ester copolymer than when the elastomer is used alone. When used in combination, the melt viscosity will be much lower than before the impact resistance improvement, since a fairly small amount is required. Furthermore, when this modification method was applied to a flame retardant polyphenylene oxide composition, the resulting composition retained its flame retardancy due to the small amount of styrenic thermoplastic elastomer that reduces flame retardancy. The effect of maintaining high impact resistance was also confirmed.

The present invention will be explained in more detail below.

The components of the composition of the present invention (→, i.e., polyphenylene oxide resins) have the general formula FlI, R- and R4 are hydrogen, halogen,
Monovalent substitution selected from alkyl groups, alkoxy groups, haloalkyl groups having at least two carbon atoms between the halogen atom and the phenyl ring, and herooalkoxy groups containing no tertiary α-carbon. represents a polyphenylene oxide or a copolymer thereof represented by the group )'19. In a preferred example, Rsm and 1tI are an alkyl group having 1 to 4 carbon atoms, and "a@TL* is hydrogen or 1 carbon atom"
~4 alkyl group. Examples of these polyphenylene oxides include poly(2,6-dimethyl-1,4-phenylene) oxide, poly(2,6-diethyl-1,4-phenylene)
phenylene) oxide, poly(2-methyl-6-ethyl-1,4-phenylene) oxide, poly(2-methyl-
6-broby-1,4-phenylene) oxide, poly(
2,6-dipropyl-1,4-phenylene) oxide,
Examples include homopolymers such as poly(2-ethyl-6-broby-1,4-phenylene) oxide and poly(2,6-diethyl-1,4-phenylene) oxide. A particularly useful homopolymer is poly(2°6-cymethyl-1,
4-7enylene) oxide. Further, the polyphenylene oxide copolymer includes a copolymer partially containing an alkyl trisubstituted phenol represented by 2,3,6-todamethylphenol in the polyphenylene oxide repeating unit.

In addition, the component (b) of the resin composition of the present invention, that is, the polyphenylene oxide resin combined with the polystyrene resin, may be a blend of the polyphenylene oxide resin with a polystyrene resin, or the phenylene oxide homopolymer or a composition mainly composed of the above-mentioned phenylene oxide homopolymer or this structure. Examples include polyphenylene oxide copolymers to which part or all of polystyrene is grafted.

The above polyprene or polystyrene resin has the general formula (in the formula, 0 is an alkyl group having 1 to 4 carbon atoms or a halogen, 2 is hydrogen, an alkyl group having 1 to 4 carbon atoms, or a vinyl group, and p is an integer from 1 to 5)
It must have a small number of repeating units derived from a vinyl aromatic compound (both 26 by weight).

Such polystyrene resins include, for example, homopolymers of styrene or its derivatives, as well as known compounds such as polybutadiene, polyisoprene, butyl rubber, 126M rubber, ethylene-propylene copolymer, natural rubber, polysulfide rubber, polyurethane rubber, and shrimp chlorohydrin. If,
Styrenic polymers and also styrene-containing copolymers, such as styrene-acrylonitrile copolymers (RAN), styrene-phtadiene copolymers, modified by mixing or interacting with natural or synthetic elastomers. , styrene-m water? Leic acid copolymer, styrene
Acrylonitrile-butadiene terpolymer (Mu18)
, poly-α-methyl-styrene, a copolymer of ethylvinylbenzene and divinylbenzene, and the like. Sarak
.

Preferred resins for the present invention are polystyrene homopolymers or rubber-modified polystyrenes mixed with or grafted with 3 to 30, preferably 4 to 12 parts by weight of polybutadiene rubber or IPDM rubber.

In addition, the above mPD group is a rubbery interpolymer consisting of a mixture of heptanoolefins and polyene, and ethylene, α-
Includes those made from olefins and polyenes. A preferred type of rubbery interpolymer is ethylene 10-9
α-olefin 710 containing 0 mol and 3 to 16 carbon atoms
It consists of 0.1 to 12 moles of polyene, which is a non-conjugated cyclic or linear diene having 5 to 20 carbon atoms. Particularly preferred types of rubbery interpolymers include alpha-olefins containing from 3 to 10 carbon atoms and
~10 non-conjugated cyclic or linear dienes. Useful PDI rubbers include ethylene-propylene-ethylidenenorporene terpolymers and Rltshl.
@Vinyland A11iel Polym@r
Preferred IPDM rubbers include terpolymers of ethylene, propylene and 5-ethylidene-2-norbornene, ethylene, propylene and 1,4- These are a terpolymer consisting of hexadiene and a terpolymer consisting of ethylene, propylene, and dicyclopentadiene.

The content of the polyphenylene oxide resin in the component is 15 parts by weight or more, preferably 20 parts by weight or more.

Specific examples of the component (O) in the composition of the present invention, that is, the unsaturated carboxylic acid ester moiety of the ethylene-unsaturated carboxylic acid ester copolymer, include ethyl acrylate,
Acrylic esters such as methyl acrylate, 2-ethylhexyl acrylate, and stearyl acrylate; methacrylate esters such as methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, and 7-acrylic methacrylate; Preferred ethylene-unsaturated carboxylic acid ester copolymers used are ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer and ethylene-methyl methacrylate copolymer, more preferably ethylene-ethyl acrylate copolymer. It is a combination. The content of ethyl acrylate in the ethylene-ethyl acrylate copolymer is 3 to 60 kg, preferably 5 to 50 kg. Also, is the melt index of ethylene-ethyl acrylate copolymer A8? 0.2-400 f/10 si, measured at 190°C by the method of MD-1238
When n is preferably less than e O, 2f/10111n, the copolymer becomes a giant polymer and is not sufficiently dispersed in the polyphenylene oxide resin composition, resulting in less blending effect. Moreover, if it exceeds 400 f/l Q sin, the heat resistance of the copolymer will decrease and decomposition will occur during molding of the poly7-ethylene oxide resin composition, which is undesirable.

The styrenic thermocarbonable elastomer of component (d) in the composition of the present invention is a block copolymer of a diene rubber center block such as polybutadiene and a polyvinyl aromatic hydrocarbon end block such as polystyrene, or a block copolymer of such a block copolymer It is an additive. The end blocks of this styrenic elastomer are vinyl aromatic hydrocarbon polymers made of styrene, α-methylstyrene, vinylstyrene, vinylxylene, ethylvinylxylene, vinylnaphthalene, etc., and mixtures thereof, and the end blocks are of the same type. It may be a polymer or a different polymer.

The central block is, for example, a rubbery polymer consisting of butadiene, propylene, isoprene, 1,3-pentadiene, 2.3-dimethylbutadiene, etc., and mixtures thereof. Furthermore, the block copolymers can have either a linear sequence or a structure such as teleradial. Furthermore, until at least 80%, preferably 90 or more, of the aliphatic double bonds in the thermoplastic styrenic elastomer become saturated bonds (that is, until the degree of unsaturation is reduced to 10 tones or less of the initial degree of unsaturation). Hydrogenated ones are also used as styrenic thermoplastic elastomers. The ratio and average molecular weight of the components of these block copolymers can vary over a wide range, but the molecular weight of the central block should be greater than the total molecular weight of the end blocks. For example, about 4000 to 115
End blocks with an average molecular weight of 000 and approximately 200
Preferably, the block copolymer is formed from a central block having an average molecular weight of from 00 to 450,000', the end blocks having an average molecular weight of from about 8,000 to 60,000, while the central block has an average molecular weight of from about 500 to 50
It is even more preferable to have an average molecular weight of oooo,
The end blocks are preferably two blocks of the entire block copolymer.
~33wt-1 more preferably! Configure S~30 weight sounds. Preferred copolymers have a polybutadiene-type central block and 35 to 55 butadiene carbon atoms;
More preferably, it is formed from a copolymer having 40 to 50 vinyl side chains. Particularly preferred components in the present invention (
The term refers to a styrenic thermoplastic elastomer in which the end blocks are homopolystyrene and the central block is polybutadiene, or hydrogenated versions thereof.

In the composition of the present invention, the component (0), that is, the ethylene-unsaturated carboxylic acid ester copolymer and the component (that is, the styrene thermoplastic elastomer) are each 0.5 to 25% by weight based on the component -1 preferably 1 to 2
It is blended at a ratio of 0% by weight.

If this amount is less than 0.5% by weight, it will be difficult to achieve the desired blending effect, whereas if this amount is less than 25% by weight, the mechanical properties of the molded product, particularly the rigidity, will be significantly reduced, which is not preferred.

Further, by adding a twist retardant to impart nonflammability or self-extinguishing properties to the composition of the present invention, a flame-retardant thermoplastic resin composition can be obtained.

Such flame retardants include halogenated organic compounds, mixtures of halogenated organic compounds and antimony compounds, elemental phosphorus, phosphorus compounds, and compounds containing phosphorus-nitrogen bonds. or a mixture of them in an amount of 2 ml or more.

The polyphelene oxide resin composition of the present invention may contain resin additives commonly used depending on the application.For example, plasticizers, stabilizers, antioxidants, lubricants, pigments, dyes. , drip retardants, processing aids, etc., or inorganic mineral fillers, fibrous, particulate, flaky or pulverized glass, etc. may be included.

The resin composition of the present invention can be easily produced by a known method of melting or solution mixing thermoplastic resins.

For example, a method of feeding pellets together, pellets and powder, or powder together to an extruder and mixing and extruding, a method of mixing and extruding into a sheet using a kneader or roll, and a method of mixing as a solution. The method to do this is widely adopted.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

In the following examples, all resin compositions were prepared in the following manner. First, the ingredients were thoroughly dispersed in a Henschel mixer.

The mixture thus preliminarily mixed was passed through a 50 W twin screw extruder with a cylinder temperature of about 280 to 300° C. to melt and mix, and then pelletize. The cooled extrudate was then injection molded at a mold temperature of 70°C in an injection molding machine set at a cylinder temperature of 220-270°C. Physical testing of the compositions was conducted by the following method. In other words, the heat distortion temperature is 1
When the notched izot impact was applied to &6, the tensile strength was A.
Measurements were made using 8〒M method No. 5 dumbbells. Melt viscosity is measured at 280°C at a shear rate of 150°7 seconds.

Also, poly(2,6-cymethyl-1,4-phenylene)
The oxide resin is in powder form and has an intrinsic viscosity of 0.46 to 0.
It belonged to 5dllf. Furthermore, tridecyl phosphite and triphenyl phosphate were used as a stabilizer and a flame retardant, respectively. Furthermore, as other composition components, products having respective characteristics were arbitrarily selected as shown below and used in the following Comparative Examples and Examples. Therefore, the components used in these comparative examples and examples are merely representative examples, and any component can be used as long as it has the same or similar characteristics. In the following comparative examples and examples, the components used were homopolystyrene resin (Mitsubishi Monsanto Chemical Industries trade name Dialex HF77), diene rubber modified polystyrene resin (Mitsubishi Monsanto Chemical Industries trade name Dialex 1!75),
lPI) M rubber-modified polystyrene resin (Mitsui Toatsu Chemical Industries trade name Toughlite 95G-Of), polystyrene-hydrogenated polybutylene-polystyrene block copolymer (Shell Chemical trade name Kraton Q-1650), polystyrene-polybutadiene-polystyrene block copolymer Polymer (Shell Chemicals trade name 1-1101) and polystyrene-polybutadiene-radial block copolymer (Philips Chemicals trade name Ig-411). The ethylene-ethyl arylate copolymers having the characteristics listed in Table 1 were appropriately used.

Table 1 Ethylene-ethyl acetate melt index-acrylate copolymer rate content! IUc-6220” 7 4
DPDJ-8026“ 8 13DPI
)J-6182" 15 1.5DP
DJ-9169” 20 20111
A tree JiiA 25 2
011 resin 1 22 21
mA resin C resin 24 260
1mA Tree Warp 34.5
19011AItJfil 5
250xxh resin v 14
2501mA resin 0 2
5 100 (1) A8? M n-1
238 (19QC)? Measurement (b) Nippon Unicar Trade Name Fuki ■C Copolymer - Comparative Example 1.2 and Examples 1 to 5 Each sample was extruded into pellets according to the composition shown in Table 2, and then molded and the properties of the pellets were tested. The physical properties of each are listed in Table 2.

As is clear from Table 2, in Comparative Example 2, in which impact resistance was improved by adding a polystyrene-hydrogenated polybutadiene-polystyrene block copolymer to the composition of Comparative Example 1, a slight increase in melt viscosity was observed. However, in the examples in which ethylene-ethyl acrylate copolymer was blended with this, although the impact resistance was further improved as the blended amount was increased, the melt viscosity clearly showed a tendency to decrease. ing. This effect is remarkable, and the melt viscosity in Example 3 is already lower than that in Comparative Example 1. What is noteworthy is that although the melt viscosity was significantly reduced due to the blending effect of this number and the ethylene-ethyl acrylate copolymer,
The decrease in heat distortion temperature is difficult to recognize.

Considering that the blending ratio of the polyphenylene oxide resin, which is dominant in the heat distortion temperature of the polyphenylene oxide resin composition, is reduced by the blending of the ethylene-ethyl acrylate copolymer with a low glass transition point, the relative balance ζ decreases. (This was an unexpected effect. Even when the injection molded products of Comparative Examples 1 and 2* and Examples 1 and 2.3 were bent and bent, no bamboo skin-like peeling phenomenon was observed. Some bamboo peel-like peeling was observed in the injection molded product of Example 5.

Comparative Example 3.4 and Examples 6 to 14 Each sample was prepared using various ethylene-ethyl acrylate copolymers having different polymerization degrees and ethyl acrylate contents based on the compositions listed in Table 3. The composition was prepared in almost the same manner as the composition, and the physical properties of each were measured, and the results are shown in Table 3.
It was shown to.

As can be seen from Table 3 above, the nine types of ethylene-ethyl acrylate copolymers used have different molecular weights and ethyl acrylate contents.
Nevertheless, it exhibits the same excellent improvement effect as explained with the composition in Table 2. Furthermore, no bamboo skin-like bulges were generated even when the molded products of any of the samples were bent.

Comparative example 5. It and Examples 15 to 17 Each sample was prepared with the composition ratio shown in Table 4, and the physical properties of each were recorded at the bottom of the table. Tridecyl phosphite is added to these compositions as a stabilizer.

Table 4 Polymer Polybutadiene Radial Block @ 11 Luminous Resin G As is clear from Table 4, various styrene-based thermocarbonable elastomers were modified in combination with ethylene-ethyl acrylic resin copolymer. Although there were some differences in the quality effect, the reforming effect aimed at by the present invention was clearly seen in all the examples. Furthermore, even when the molded products of each sample were bent, no bamboo skin-like peeling occurred. In addition, Example 15
When compared with Comparative Example 2, the former is superior not only in fluidity but also in the gloss of the molded surface, although the mechanical strength is almost the same. Both are composed of polyphenylene oxide resin and diene rubber-modified polystyrene resin in the same composition ratio, but the former is further blended with 5 parts by weight each of styrene-hydrogenated polybutadiene-styrene block copolymer and ethylene-ethyl acrylate copolymer. The latter is presumably due to the fact that only 10% of the polystyrene-hydrogenated polybutadiene-polystyrene block copolymer was blended alone. That is, in Comparative Example 2, 10% by weight of the styrene-based thermocarbonable elastomer, which greatly reduces processability and significantly inhibits surface gloss, is required in order to obtain the same mechanical strength, whereas in Example In the case of 15, it is only half, 5% by weight.
This is probably due to the fact that only ◎ Comparative Examples 6 to 9 and Examples 18 to 20 Each sample was prepared according to the composition listed in Table 5. The physical properties of each were measured and added to the same table.

According to Table 5 above, it can be confirmed that even if the blending amount of the styrene-based thermoplastic elastomer is changed within the range of the present invention, the modification effect aimed at by the present invention clearly appears. Even when the molded products of all the samples were bent, no bamboo skin-like peeling was observed.

Comparative Example 10.11 and Example 21.22 Samples were prepared from mixtures with composition ratios containing stabilizers shown in Table 6,
Their physical properties were measured. The results are shown in the same table.

Table 6 411 DPDJ-91439 As is clear from Table 6, even when a homopolystyrene resin is blended in place of the rubber-modified polystyrene resin, the same improvement effect aimed at by the present invention is achieved. Even when the molded products of each composition were bent, no bamboo skin-like peeling phenomenon was observed.

Table 7 shows the compounding ratio and physical properties of the samples prepared in Comparative Examples 12.13 and Examples 23 to 27. As is clear from this table, IIPDM is used as a polystyrene resin.
The effects of the present invention on the rubber-modified Posa-modified ponstyrene resin are extremely clear.

Bamboo skin-like peeling did not occur even when the molded products of all samples were bent.

Comparative Examples 14 and 15 and Examples 28 and 29 Samples were prepared based on the composition ratios listed in Table 8, and the same physical properties as described above were measured. Furthermore, the following tests were conducted on the above samples.

That is, a plate with a thickness of 2.7 m was placed on a support stand with a hole diameter of 35 m, and the impact strength of a falling ball was tested with a center of impact of 1 inch radius, and the strength at which cracks occurred in half of the plates was determined. Notched isot impact strength and falling ball impact strength were also measured at a low temperature of -30°C.

In addition, the condition of an inch-thick test piece that was subjected to bending strain and brought into contact with gasoline for 10 minutes was observed to determine chemical resistance. The above physical table 8 1111 1mm Resin A, Recommendation 0 indicates the measured value at -30°C. Even in these samples, impact resistance was improved without lowering the heat distortion temperature mentioned above and without deteriorating fluidity. Although the effect of the present invention in improving the
Furthermore, compositions containing ethylene-ethyl acrylate copolymer exhibit surprisingly high impact strength at low temperatures, particularly in the impact of falling balls. It is also clearly shown that the chemical resistance (gasoline resistance) of the composition containing the ethylene-ethyl acrylate copolymer is significantly improved. In addition,
Even when the sample molded product was bent, no bamboo skin-like peeling occurred.

Comparative Example 16 and Examples 30 and 31 Samples whose composition ratios are shown in Table 9 were prepared, and their physical properties are summarized in the same table.

Table 9 - Polystyrene-podbutadiene-radial protrusion copolymer - sulfuric acid resin Each sample contained 10 parts by weight of triphenyl phosphate, but the desired effects of the present invention as described above were clearly achieved. be.

In addition, if a small amount of styrene-based thermoplastic elastomer, which reduces flame retardance, is blended, a sufficient improvement in impact resistance can be obtained due to the combination effect number ζ with ethylene-ethyl acrylate copolymer. It can be seen that the composition shows no decrease in flame retardancy at all compared to before modification.

Even when the molded products of all the samples were bent, no bamboo skin-like peeling was observed.

Comparative Examples 17 and 18 and Example 32 Modified polyphenylene ether resins were treated with polystyrene-hydrogenated polybutadiene-polystyrene block copolymer alone and polystyrene-hydrogenated polybutadiene-polystyrene block copolymer with ethylene-ethyl acrylate as shown in Table 10. The same degree of impact resistance improvement was measured depending on the polymer combination number ζ, and the physical properties before and after modification were measured and are listed in Table 10.

Table 10 Asahi Dow Product Name: Zylon 5oov f#11 Resin A In Resin Example 18 and Example 32, compositions with more than twice the Izot impact strength were obtained, but in terms of melt viscosity, Comparative Example 1B had The fluidity of the composition of Example 32 is much higher than that of Example 32, and is even better than that of Comparative Example 17 before modification. Moreover, the composition of Example 32 was the composition of Comparative Example 18.
The gloss of the molded surface was superior to that of the composition. Even when the molded products of each sample were bent, no bamboo skin-like peeling phenomenon was observed.

Comparative Example 19 and Example 33 Samples having the composition ratios shown in Table 10 were prepared, and their physical properties were measured. The results are listed in Table 11.

Table 11 m 1IIA Resin A It is known that polyphenylene oxide resins that cannot be combined with polystyrene resins have slightly inferior moldability and impact resistance as described above. In order to compensate for these drawbacks of polyphenylene oxide resin, Comparative Example 19 was prepared in which a butylene thermoplastic elastomer containing triphenyl phosphate as a plasticizer was combined as an impact modifier. Example 33 clearly shows the effect of adding an ethylene-ethyl acrylate copolymer to this sample. That is, the melt viscosity was significantly reduced and the Izod impact strength was significantly improved. Furthermore, the flammability is not inhibited at all by the addition of the ethylene-ethyl acrylate copolymer.

As described above, the modification effect of the ethylene-ethyl acrylate copolymer is extremely effective even in the composition of the polyphenylene oxide resin alone.

Continuation of page 1 ■Submitted by: Honda Motor Co., Ltd. 6-27 Jingumae, Shibuya-ku, Tokyo No. 8

Claims (1)

[Claims] 1. (-poly7 engineered lene oxide resin or (b) polyphenylene oxide resin combined with polystyrene resin, (.) ethylenically unsaturated carboxylic acid ester copolymer, and (d) polystyrene terminal block) and a styrenic thermoplastic elastomer consisting of a diene rubber central block, or a styrene thermoplastic elastomer obtained by hydrogenating the diene rubber central block, and the component (萄 or (for the component (@)) A resin composition characterized in that the polyphenylene oxide resin is present in an amount of 0.5 to 25 wt. The atoms are bonded to adjacent units phenylIn, n is an integer of at least 50, and L, is, is and R- are hydrogen, halogen,
Alkyl groups, alkoxy groups, halalkyl groups and haloalkoxy groups having at least 2 carbon atoms between the halogen atom and the phenyl ring, containing a tertiary α-carbon! 2. The composition according to claim 1, which is a polyphenylene oxide represented by the following monovalent substituent selected from the following: or a copolymer mainly consisting of this structure. 3. General formula (in the formula, the ether oxygen atom of one unit is bonded to the phenyl ring of the adjacent unit, n is a small number (both are integers of 50, R,, R,, Rm and ER@ are hydrogen or Monovalent substitution selected from halogens, alkyl groups, alkoxy groups, haloalkyl groups having at least 2 carbon atoms between the halogen atom and the phenyl ring, and haloalkoxy groups that do not contain a tertiary α-carbon The composition according to claim 1, wherein a polyphenylene oxide represented by the following group or a copolymer mainly composed of this structure is blended or graft copolymerized with a polystyrene resin as the component thing. 4. The composition according to claim 2 or 3, wherein 11 and the island are methyl groups, and Ra and H4 are hydrogen. 5. The polystyrene resin has the general formula (in the formula, the abbreviation is hydrogen, an alkyl group having 1 to 4 carbon atoms, or a halogen, the window is hydrogen, an alkyl group having 1 to 4 carbon atoms, or a vinyl group, and P is 1 ~5 integer)
The composition according to claim 1 or 3, which is a polystyrene resin having at least 25 polymer units derived from a vinyl aromatic compound represented by the following formula. 6. The composition according to claim 1, wherein the polystyrene resin is homopolystyrene, diene rubber-modified polystyrene, or 1lPf) iris rubber-modified polystyrene. 7. The composition according to claim 1, wherein the content of polyphenylene oxide resin in component (b) is 15 parts by weight or more. 8. The polystyrene end block of the styrenic thermoplastic elastomer is a vinyl aromatic hydrocarbon polymer consisting of styrene, α-methylstyrene, vinylstyrene, vinylxylene, ethylvinylxylene, vinylnaphthalene, and mixtures thereof, and diene rubber The central block is butadiene, propylene, imprene, 1゜3-
The composition according to claim 1, which is a rubbery polymer consisting of pentadiene, 2,3-dimethylbutadiene, and a mixture thereof, and both are linear sequence or radial teleblock copolymers. . 9. The above-mentioned styrenic thermoplastic elastomer 7- is one in which the degree of unsaturation of the diene rubber central block is reduced to 10% or less of the initial degree of unsaturation by hydrogenation treatment. The composition described in Section. 10. The composition according to claim 1, wherein an ethylene-ethyl acrylate copolymer having an ethyl acrylate content of 3 to 60 kg is used as the ethylene-unsaturated carboxylic acid ester copolymer. 11. The composition according to claim 1, which is rendered flammable by mixing a flame retardant. 12. The above-mentioned flame release agent is a halogenated organic compound, a mixture of a halogenated organic compound and an antimony compound, an 8-element syn, a phosphorus compound, a compound containing a phosphorus-nitrogen bond, or a mixture of two or more thereof. A composition according to claim 11.