JPH0668075B2 - Resin composition containing polyamide and polyphenylene sulfide - Google Patents

Description

TECHNICAL FIELD The present invention relates to mechanical properties including a polyamide resin and a polyphenylene sulfide (PPS) resin having an end group ratio (molar amount of amino group / molar amount of carboxyl group) of more than 1. It relates to an excellent resin composition.

Problems to be Solved by Conventional Techniques and Inventions Polyamide resins are excellent in solvent resistance, toughness, etc., but have drawbacks such as deterioration of mechanical properties due to moisture absorption, dimensional instability, and deterioration of rigidity at a temperature higher than the glass transition temperature. have. In order to improve these drawbacks, reinforcement by filling various inorganic fillers has been carried out. However, with these methods, "warpage" occurs in molded products molded by various molding methods (for example, injection molding, extrusion molding, etc.), impact resistance decreases, etc. I can't get it.

Polyphenylene sulfide (PPS) resin is heat resistant,
It has excellent flame retardancy and rigidity, but has the drawback of being brittle against impact. In order to remedy this drawback, reinforcement with various inorganic fillers has been carried out. However, the fragility to impact has not been sufficiently improved.

Attempts have been made to combine the original excellent properties of PPS and polyamide by blending PPS and ordinary polyamide (end group ratio of 1 or less) (for example, JP-A-53).
-69255). However, the mere blending of the compounds results in poor compatibility between PPS and polyamide, poor surface condition of the molded product, phase separation, and satisfactory physical properties cannot be obtained.

JP-A-59-155462 proposes the addition of an epoxy resin in order to improve the compatibility between PPS and polyamide, but it is not yet practically satisfactory and improvement is desired.

Therefore, an object of the present invention is to provide a resin composition containing a polyamide and polyphenylene sulfide, which has a good appearance of a molded article and satisfactory physical properties.

Means for Solving the Problems The present invention is based on the finding that the compatibility with PPS is remarkably improved by increasing the ratio of terminal amino groups to terminal carboxyl groups of polyamide.

That is, the present invention to achieve the above object, in a resin composition comprising a polyamide resin and a PPS resin in a weight ratio of 10:90 to 90:10, the polyamide resin has a terminal amino group more than the amount of terminal carboxyl groups. Is a resin composition.

The polyamide used in the present invention is not a polyamide usually used for molding, that is, a polyamide having the same amount of terminal amino groups and the amount of terminal carboxyl groups or a polyamide having a reduced amount of terminal amino groups for stabilization, but the amount of terminal amino groups. Is a polyamide having more than the amount of terminal carboxyl groups.

Examples of the polyamide resin include nylon-4, nylon-6, nylon-6,6, nylon-12, nylon-
6, 10 and the like, but are not limited thereto. What is essential in the present invention is that the amount of terminal amino groups of the polyamide is larger than the amount of terminal carboxyl groups. Such a polyamide can be obtained by adding an extra compound such as a diamine having a group that reacts with a carboxyl group during polymerization of the polyamide. Alternatively, it can also be obtained by, for example, reacting with a compound having a group that reacts with a carboxyl group after the polymerization of polyamide. Usually, the polyamide resin has an end group ratio of 1 or less. In polyamides for injection molding, an end-capping agent is added to the polymerization component in order to adjust the melt viscosity appropriately, but the end group ratio of such a polyamide is smaller than 1.

In the present invention, the ratio of the terminal amino group amount to the terminal carboxyl group is preferably 1.01 or more, more preferably 1.1.
That is all. In particular, the end groups can be 1.3 or more.

The PPS used in the present invention has a general formula Those containing 70 mol% or more of the structural unit represented by are preferable because they provide a composition with excellent properties. PPS can be polymerized by polymerizing p-dichlorobenzene in the presence of sulfur and sodium carbonate, in a polar solution in the presence of sodium sulfide or sodium hydrosulfide and sodium hydroxide, or hydrogen sulfide and sodium hydroxide. Polymerization method, p-
Examples include self-condensation of chlorothiophenol,
A suitable method is to react sodium sulfide with p-dichlorobenzene in an amide solvent such as N-methylpyrrolidone or dimethylacetamide, or a sulfone solvent such as sulfolane. At this time, it is a preferable method to add an alkali metal salt of carboxylic acid or sulfonic acid or to add an alkali hydroxide in order to adjust the degree of polymerization. If less than 30 mol% as a copolymerization component, meta bond Ortho coupling Ether bond Sulfone bond Biphenyl bond Substituted phenyl sulfide bond Where R is alkyl, nitro, phenyl, alkoxy,
Carboxylic acid or metal base of carboxylic acid) trifunctional phenyl sulfide bond Although it may be contained within a range that does not significantly affect the crystallinity of the polymer, the content of the copolymerization component is preferably 10 mol% or less. Particularly, when a phenyl, biphenyl, naphthyl sulfide bond or the like having a functionality of 3 or more is selected for the copolymerization, the content is preferably 3 mol% or less, more preferably 1 mol% or less.

Such PPS is produced by a conventional method, for example, (1) reaction of a halogen-substituted aromatic compound with an alkali sulfide (US Pat.
No. 2513188, JP-B-44-27671 and JP-B-45-33
68), (2) Condensation reaction of thiophenols in the presence of an alkali catalyst or a copper salt (US Pat. No. 327416).
No. 5, British Patent No. 1160560), (3) Condensation reaction of aromatized compounds with sulfur chloride in the presence of Lewis acid catalyst (Japanese Patent Publication No. 46-27255, Belgian Patent No. 29437), etc. Are synthesized by the method described above, and can be arbitrarily selected according to the purpose.

PPS is currently on the market from Phillips Petroleum Co., Ltd., Tosoh Sustain Co., Ltd., Topren Co., Ltd., and Kureha Chemical Co., Ltd. There are various grades depending on the crosslink density and viscosity, and PPS having a small crosslink structure is preferred in the present invention.

In the resin composition of the present invention, the ratio of the polyamide component and the PPS component is 10 to 90 wt% for the polyamide component and 90 to 1 for the PPS component.
It is preferably 0 wt%. Polyamide component is 10wt%
If less than, impact resistance, improvement of brittleness is insufficient,
If the PPS component content is less than 10 wt%, dimensional change due to moisture absorption is large and mechanical properties deteriorate, which is not preferable.

Further, an epoxy resin may be added to the resin composition of the present invention in order to further improve impact resistance. The epoxy resin used is one containing one or more epoxy groups, and liquid or solid ones can be used. For example, bisphenol A, resorcinol, hydroquinone, pyrocatechol, bisphenol F, saligenin, 1,3,5-trihydroxybenzene, bisphenol S, trihydroxy-diphenyldimethylmethane,
4,4'-dihydroxybiphenyl, 1,5-dihydroxynaphthalene, cashew phenol, glycidyl ether of bisphenol such as 2,2,5,5-tetrakis (4-hydroxyphenyl) hexane, halogenated bisphenol instead of bisphenol, Linear systems such as glycidyl ether resins such as diglycidyl ether of butanediol, glycidyl ester systems such as glycidyl phthalate, glycidyl amine systems such as N-glycidylaniline, epoxidized polyolefins, epoxidized soybean oil, etc. And cyclic non-glycidyl epoxy resins such as vinylcyclohexenedioxide and dicyclopentadienedioxide.

Epoxy resin is 100 in total of polyamide resin and PPS resin.
It is preferably added in an amount of 10 parts by weight or less based on parts by weight. If the amount of the epoxy resin is more than 10 parts by weight, a cross-linking reaction due to the epoxy occurs, and the melt flow stability decreases,
It is not preferable because it causes deterioration of mechanical properties.

The resin composition of the present invention includes other polymers (for example, styrene resins, olefin resins, various elastomers, etc.), fillers such as glass fibers, carbon fibers, talc, kaolin, flame retardants, plasticizers, pigments, etc. Can be included.

The composition of the present invention can be adjusted by various known methods. For example, the raw materials may be mixed in advance with a mixer such as a tumbler or a Henschel mixer, supplied to a uniaxial or biaxial extruder, melt-kneaded at 230 to 400 ° C., and then pelletized. .

Hereinafter, the present invention will be described more specifically with reference to Examples.

Examples 1-2 and Comparative Examples 1-2 As polyamides, polyamide-6 having a molecular weight of 13,000 and having terminal amino groups of 8.4 × 10 ^-5 mol / g and terminal carboxyl groups of 1.8 × 10 ^-5 mol / g (hereinafter, PA6-A) was used. For comparison, a polyamide-6 (hereinafter referred to as PA6-B) having a molecular weight of 13,000 having a terminal amino group of 4.6 × 10 ^-5 mol / g and a terminal carboxyl group of 7.0 × 10 ^-5 mol / g (hereinafter referred to as PA6-B)) is used. Using.

As PPS, PPS T-4 (trademark) manufactured by Topren Co., Ltd. having a melt viscosity of 3900 poise under the conditions of 300 ° C. and a shear rate of 200 sec ⁻¹
Was used.

A novolac type epoxy resin (Epiclon N-695 (trademark, manufactured by Dainippon Ink and Chemicals, Inc.)) was used as the epoxy resin.

These components were mixed in the proportions shown in Table 1 and extruded with a twin-screw extrusion base (screw diameter 50 mm) set at 300 ° C. to produce pellets. Cylinder temperature 32 after drying this pellet
A test piece was molded using an injection molding machine set at 0 ° C. and subjected to various characteristics tests. The test results obtained are shown in Table 1.
As shown in.

Each test was conducted according to the following method.

(1) Izod impact strength (without notch): ASTM D256 (2) Heat distortion temperature: ASTM D648 (4.6 kg / cm ² load) (3) Breaking energy: ASTM D790 (Energy value up to breaking is calculated. ) (4) Appearance of molded product: Visual In all tests, the compositions according to the invention (Examples 1 and 2) show better results than the compositions according to Comparative Examples 1 and 2. In particular, the impact strength shows a dramatic increase.

Claims (1)

[Claims] 1. A resin composition comprising a polyamide resin and a polyphenylene sulfide in a weight ratio of 10:90 to 90:10, wherein the polyamide resin has an amount of terminal amino groups higher than an amount of terminal carboxyl groups. Composition.