JPH0488058A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a multicomponent thermoplastic resin composition having excellent heat-resistance, impact resistance, etc., by compounding a modified polyphenylene ether resin with specific amounts of a specific polyamide resin, a rubber component and a crystal nucleation agent. CONSTITUTION:The objective composition having a crystallinity of a polyamide resin phase of 20-40% can be produced by compounding (A) 10-70wt.% of a modified polyphenylene ether resin, (B) 90-30wt.% of a polyamide resin which is an aliphatic polyamide resin having a relative viscosity of <=4 (e.g. nylon 6 and nylon 66), (C) 5-30wt.% of a modified and/or unmodified rubber-like component and (D) <=5 pts.wt., preferably 0.01-1 pt.wt. (based on 100 pts.wt. of the component B) of a crystal nucleation agent (e.g. talc and silica).

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a multicomponent thermoplastic resin composition having excellent heat resistance, impact resistance, etc.

<Conventional technology> A polymer blend resin mainly composed of polyphenylene ether and polyamide combines the excellent moldability and chemical resistance of polyamide with the excellent heat resistance, dimensional stability, and water resistance of polyphenylene ether. As a resin, it is expected to be used in automobile parts in recent years.

Among these, the development of applications for automobile exterior panel materials has begun to attract particular attention.

In general, the important characteristics required for automotive exterior skin materials are:
It is desired to have heat resistance that can withstand on-line coating temperatures (approximately 150° C.) and high impact resistance as a practical matter.

However, since the heat resistance and impact resistance of resin materials are originally contradictory properties, many studies have been reported to solve this problem.

Typical examples include combinations of polyamide, acid-modified polyphenylene ether, and styrene-butadiene-styrene block copolymers (Japanese Patent Application No. 1464/1986).
No. 33), polyamide, acid-modified polyphenylene ether, hydrogenated styrene-butadiene-styrene copolymer combination (JP-A-62-138553), polyamide, acid-modified polyphenylene ether, acid-modified hydrogenated styrene-butadiene A combination of styrene block copolymers (JP-A-62-68850), a combination of polyamide, acid-modified polyphenylene ether, and a combination of acid-modified and unmodified hydrogenated styrene-butadiene-styrene block copolymers ( Japanese Patent Publication No. 1-1498
No. 53) and others with improved polyphenylene ether and rubber-like components. On the other hand, regarding polyamides, those using non-quality polyamides (
JP-A No. 1-149852), polyamide molecular weight and terminal amino group concentration (JP-A No. 63-3095)
55), those using a mixture of two or more polyamides (JP-A-64-38468, JP-A-63-23536)
No. 1), one using aromatic polyamide (Japanese Unexamined Patent Publication No. 1983-
68663, JP-A No. 60-15453), etc.

<Problems to be Solved by the Invention> The above-mentioned prior art aims at improving properties based on the combination of modification by acid modification of polyphenylene ether and rubber-like components and various polyamide resins.
In other words, the main focus of the conventional technology up to now has been to improve the technology for controlling the well-known sea (polyamide)-island (polyphenylene ether) structure in blend resins made of polyphenylene ether and polyamide. For a composition consisting of a dispersed phase and a polyamide matrix phase, we devised a compatibilization method including modification of compatibilizers and raw materials to stabilize the interface, adjust the particle size of the dispersed phase, and specify the specific arrangement of the rubber-like component. By doing so, a resin composition with good balance between heat resistance and impact resistance and excellent impact resistance is obtained.

However, as a result of creating a characteristic map (see Figure 1) of a known resin composition consisting of polyphenylene ether and polyamide, it was found that while the impact resistance (Izot impact value, notched) increased, the heat resistance (heat distortion temperature) increased. It has been found that there is a tendency to decrease, and there is still room for investigation into improving the performance of the corresponding resin composition that has both heat resistance and impact resistance at a high level.

Means for Solving the Problems> Therefore, the present inventors developed a polyamide/polyphenylene ether that achieves both the above-mentioned heat resistance and impact resistance at a higher level than before (the dotted shaded area in Figure 1). (As a result of intensive study, we found that in addition to the conventional sea-island structure control technology, we also controlled the higher-order structure (crystallization rate and degree of crystallinity) of the matrix polyamide phase. The present invention has been achieved by discovering that the problems can be solved and an excellent material having both heat resistance and impact resistance at higher levels than before can be obtained.

That is, the present invention uses 10 to 70% by weight of modified polyphenylene ether resin and 90 to 30% by weight of polyamide resin.
, and modified and/or unmodified rubber-like components 5 to 30
In a multi-component resin composition consisting of % by weight, an aliphatic polyamide resin having a relative viscosity of 4.0 or less is used as the polyamide resin, and 5.0 parts by weight per 100 parts by weight of the polyamide resin.
The present invention provides a thermoplastic resin composition characterized in that it contains a crystal nucleating agent in an amount of not more than 1 part by weight.

The degree of crystallinity of the polyamide resin phase in the multicomponent thermoplastic resin is preferably in the range of 20 to 40%.

The present invention will be explained in more detail below.

Polyphenylene ether, which is a raw material for the modified polyphenylene ether used in the present invention, is produced by oxidative polymerization of phenols such as 2,6-dimethylphenol and 2,3,6-1-rimedylphenol, either alone or in the coexistence. obtained by doing.

On the other hand, the method for modifying the modified polyphenylene ether used in the present invention uses a substituted olefin compound having at least one functional group represented by carboxylic acid, carboxylic acid anhydride group, epoxy group, etc. as a modifying component, such as acrylic acid,
Glycidyl methacrylate, maleic anhydride, etc. and polyphenylene ether, or the modified component and polyphenylene ether with a rubber-like component added thereto, in the coexistence of a suitable radical generator such as benzoyl peroxide, t-butyl hydroperoxide, dicumyl peroxide, etc. It is obtained by melt-mixing under a temperature condition of 200 to 350°C.

The proportion of the modified polyphenylene ether thus obtained in the final resin composition is 10 to 70% by weight. 10% by weight of modified polyphenylene ether
If it is less than 70% by weight, the final product will lack heat resistance, and if it exceeds 70% by weight, the polyphenylene ether resin will have a sea-island structure, resulting in a significant loss of moldability.

The polyamide resin, which is one of the components used in the present invention, accounts for 90 to 30% by weight in the final resin composition. When the polyamide resin content is less than 30% by weight, fluidity deteriorates and moldability is impaired. If it exceeds 90% by weight, heat resistance will deteriorate.

The polyamide resin includes known polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 6), and polyhexamethylene adipamide (nylon 6).
These are aliphatic polyamides represented by 6) and the like, and polyamides having a relative viscosity (ηr) value of 4.0 or less, more preferably 3.0 or less are particularly suitable. In other words, as is well known, polyamide resin is a crystalline resin, but its degree of crystallinity is due to its low relative viscosity (low molecular weight).
Then, it increases. Therefore, when a polyamide with low relative viscosity and good fluidity was used in a resin composition consisting of polyphenylene ether and polyamide, it was found that the crystallinity of the polyamide phase in the final product increased and the heat resistance improved.

Furthermore, a crystal nucleating agent such as talc, silica, graphite, lead phosphate, magnesium oxide, aluminum oxide, titanium oxide, sodium stearate, calcium stearate, high melting point nylon, melamine cyanurate, etc. is added to the above-mentioned well-flowing polyamide resin. It has been found that by using an inorganic compound and an organic compound in combination, the crystallization rate is increased and the crystals are made fine and uniform, thereby exhibiting more favorable performance as a material.

The amount of the crystal nucleating agent added varies depending on the type, but is usually 5.0 parts by weight or less, preferably 0.01 to 1.0 parts by weight, more preferably 0.05 parts by weight, per 100 parts by weight of the polyamide resin. 0.5 part by weight. If the amount is less than this, there will be no effect, and if it is more than this, the impact resistance will decrease, which is not preferable.

The modified and/or unmodified rubber-like component used in the present invention may be used alone or in combination, and is a block copolymer elastomer with a basic structure of A-B-A' type, for example, They are typified by styrenic copolymers such as styrene-butadiene-styrene block copolymers and hydrogenated styrene-butadiene-styrene block copolymers, and these are widely available commercially. For modified products, the same method as for polyphenylene ether described above is adopted, but as a modification method, the polyphenylene ether and a rubber-like component may be mixed in advance, or some commercially available products may be used. is also possible.

The amount of these rubber-like components added is 5% in the final resin composition.
It is preferable to use up to 30% by weight (if it is less than this, the impact strength of the final product will decrease, which is not preferable. If it is too much, it will lead to a decrease in heat resistance, which is not preferable).

In the present invention, there are no particular limitations on the method of mixing polyphenylene ether resins, polyamide resins, rubber-like components, and crystal nucleating agents; Bye. Also,
There is no particular order in which to mix each component. Mixing may also be performed.

The resin composition of the present invention may contain other additives such as pigments, dyes, reinforcing agents, fillers, heat resistant agents, oxidative deterioration inhibitors, weathering agents, and lubricants during mixing and molding of the resin, as long as they do not impair its properties. , mold release agent, plasticizer, flame retardant, fluidity improver,
Antistatic agents and the like can be added and introduced.

Furthermore, the resin composition of the present invention can also be used as a reinforced composite material in which glass fibers, carbon fibers, polyamide fibers, metal whiskers, etc. are added in addition to the above-mentioned compounds.

According to the present invention, for polyphenylene ether/polyamide-based materials, by using a well-flowing aliphatic polyamide resin as the polyamide resin and using this in combination with a crystal nucleating material, high crystallinity, high crystallization rate, and A polyphenylene ether/polyphenylene ether with improved crystal fineness and uniformity, and a higher level of heat resistance and impact resistance than before.
A polyamide material is obtained.

<Example> The present invention will be explained in more detail below by giving examples. The properties described in Examples, Comparative Examples, and Reference Examples were evaluated by the following method.

(1) Izot impact strength: ASTM D25G (
2) Heat distortion temperature: ASTM D648 (3) Crystallinity: Calculated from the melting peak area of DSC; (△Hca
l/g) = 0.456 (crystallinity), measurement conditions: sample amount 50 mg, temperature increase rate 7, 5°C/m1n (4) Relative viscosity of polyamide (ηr)・JISK681
0-77 (5) Molecular weight of polyphenylene ether: Measured by GPC. Toluene solvent, column; G4000Hx1 +
G2000HX 1 +G]000HX 2),
Detector UV (285 nm).

(Reference Example 1) Production of polyphenylene ether 10 g of anhydrous copper chloride, 2β nitrobenzene, and 0.7°C of pyridine were placed in a polymerization tank, and after blowing oxygen gas at 300 mβ/min for 30 minutes, 50% by weight of 2,6- Add 3ρ of nitrobenzene solution of dimethylphenol,
The mixed solution was stirred at a temperature of °C while blowing oxygen to carry out oxidative polymerization. After the polymerization, the reaction solution was diluted with chloroform at 2°C, and then the polymer was precipitated in methanol acidified with hydrochloric acid. The precipitated polymer was reprecipitated again in a chloroform/methanol system, filtered, washed, and dried to obtain polyphenylene ether. Polystyrene equivalent M n of the obtained polyphenylene ether C1.
It is 2×10'.

(Reference Example 2) Modified Polyphenylene Ether Maleic anhydride and a radical generator were added to 100 parts by weight of the polyphenylene ether obtained in Reference Example 1 alone or a mixture of 10 parts by weight of rubber-like components per 100 parts by weight of polyphenylene ether. The mixture containing 1 and 0.1 parts by weight was supplied to the hopper of an extruder, and the cylinder temperature was 300.
A modified polyphenylene ether was obtained by melt-kneading at ~320°C.

(Example 1) Modified polyphenylene ether obtained in Reference Example 2 (rubber-like component Kraton Gl 65 manufactured by Nigel Chemical Co., Ltd.)
2. Styrene-ethylene/butylene-styrene block copolymer) 45 parts by weight and maleic anhydride modified rubber-like component (Krayton FG1901X manufactured by Shell Chemical Company) 1
After tri-blending 0 parts by weight, 645 parts by weight of nylon with a relative viscosity of 2.3, and 0.05 parts by weight of talc using a Henschel mixer, the mixture was fed to the popper of a 30 mmφ twin-screw extruder, and the cylinder temperature was 260°C. The mixture was melt-kneaded at a rotational speed of 300 rpm to form pellets. After drying this pellet at 100° C. for 24 hours, injection molding was performed under conditions of a cylinder temperature of 240° C. and a mold temperature of 80° C. to obtain a test piece for characteristic evaluation. The properties of the test piece are as shown in Table 1, and a resin composition was obtained that achieved both heat deformation temperature and impact resistance at a higher level than conventional ones (dotted line range in FIG. 1). The crystallinity of the polyamide phase in this composition was as high as 32%, and according to the results of observation using a polarizing microscope, the generated spherulites were fine (several microns) and uniformly dispersed.

(Comparative Example 1) An experiment similar to Example 1 was conducted using nylon 6 with a relative viscosity of 4.8 and without using a crystal nucleating agent. The result is
Both the heat distortion temperature and impact resistance were on par with conventional products, the crystallinity of the polyamide phase was as low as 15%, and the state of spherulite formation was non-uniform.

(Comparative Example 2) An experiment similar to Example 1 was conducted using the same nylon 6 as in Comparative Example 1 and using talc as a crystal nucleating agent. The results showed that the degree of crystallinity was slightly increased compared to Comparative Example 1, and the state of spherulite generation was improved to be fine and uniform, but the heat distortion temperature and impact resistance were still in the same range as the conventional product. Ta.

(Comparative Example 3) An experiment similar to Example 1 was conducted with the amount of talc used as a crystal nucleating agent increased by 50 times. Compared to the results of Example 1, a decrease in impact resistance was particularly observed.

(Comparative Example 4) An experiment similar to Example 1 was conducted without using a crystal nucleating agent.
Compared to the results of Example 1, a decrease in heat distortion temperature was observed.

(Example 2) An experiment similar to Example 1 was conducted by lowering the polyphenylene ether/polyamide ratio. As a result, a resin composition with a higher balance of heat resistance and impact resistance than conventional products could be obtained.

(Example 3) Polyphenylene ether 40 modified with maleic anhydride
Parts by weight, unmodified rubber-like component (Kraton G1652) 5
Parts by weight, modified rubber-like component (Kraton FG1901X)
10 parts by weight, lead phosphate 0.05 parts by weight, relative viscosity 2.3
A triblend mixture containing 645 parts by weight of nylon was melt-kneaded in the same manner as in Example 1. As a result, a resin composition having properties almost the same as those of Example 1 was obtained.

(Example 4) Example 1 except that nylon 66 with a relative viscosity of 2.8 is used.
The experiment was conducted using the same raw material composition.

However, the melt mixing temperature and injection molding temperature were 280°C. As a result, a resin composition with a high degree of crystallinity (38%) and superior heat resistance than conventional products was obtained.

<Effects of the Invention> In a multicomponent thermoplastic resin composition comprising polyphenylene ether, polyamide resin, and a rubber-like component, as in the present invention, by using a well-flowing aliphatic polyamide resin and a crystal nucleating agent together, In addition to increasing the degree of crystallinity and crystallization rate of the polyamide phase in polyphenylene ether/polyamide resin materials, the fineness and uniformity of the crystals have also been improved, resulting in higher heat resistance and impact resistance than conventional products. A major feature of the present invention is that it achieves both on the same level.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a map of the characteristics (heat resistance and impact resistance) of existing polyphenylene ether/polyamide resins and the target range of the present invention.

Claims (2)

[Claims] (1) In a multicomponent resin composition consisting of 10 to 70% by weight of a modified polyphenylene ether resin, 90 to 30% by weight of a polyamide resin, and 5 to 30% by weight of a modified and/or unmodified rubber-like component, as a polyamide resin. 1. A thermoplastic resin composition comprising an aliphatic polyamide resin having a relative viscosity of 4.0 or less and a crystal nucleating agent of 5.0 parts by weight or less per 100 parts by weight of the polyamide resin. (2) The thermoplastic resin composition according to claim 1, wherein the crystallinity of the polyamide resin phase is in the range of 20 to 40%.