KR940004869B1 - Polyamide resin composition - Google Patents

Abstract

49.8-94.8 wt.% of polyamide; 5-50 wt.% of the inorganic material or reinforced fiber to be treated with the coupling agent of formula (I); 0.1-2 wt.% of heat resistant agent; and 0.1-2 wt.% of releasing agent. In the formula (I), R is the gp. of formula (II) or (III); n is 10-1000; n' is 6; n" is 10-1000. The concentration of the coupling agent solution is 0.1-80 %. The obtd. resin compsn. has improved adhesiveness, mechanical property, surface property and compatibility, and useful for car components and electric devices.

Description

Polyamide resin composition

1 is a process chart showing the treatment of a coupling agent on a filler surface in the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to polyamide resin compositions, and more particularly, to polyamide resin compositions useful for automobile parts, electrical and electronic parts, etc., mainly composed of inorganic or reinforcing fibers treated with polymer coupling agents and polyamides.

As a technique proposed to improve mechanical strength such as impact resistance as a conventional polyamide resin composition, a thermoplastic resin composition composed of a polyamide resin and a core-shell copolymer made of a rubber and an unsaturated compound and a polyamide resin (Domestic Patent Publication No. 90- 5203), a tough, thermoplastic nylon composition (US Patent No. 3584344) composed of a polyamide resin and a polyshell resin in which a copolymer of acryl or diene rubber grafted with a vinyl monomer and an unsaturated carboxylic acid monomer is used. High-impact thermoplastic polyamide molding compositions comprising carboxylic acid grafted diene or alkyl acrylate rubbers and polyamide resins are known (US Pat. No. 4,458,408), but products made with such compositions have somewhat improved impact angles. However, the surface condition and compatibility are inferior and the thermal deformation temperature It was low, making it unsuitable for use in automobile parts.

Therefore, in order to use for automobile parts etc., the composition which mainly uses the polyamide, the inorganic filler treated with the monomer coupling agent, and the reinforcing fiber is proposed and used.

In this case, the coupling agent is a monomer compound such as silane, silicone, titanium, etc., which causes the reaction with the surface of the inorganic filler or the reinforcing fiber, but such a monomer coupling agent has problems in its stability and compatibility with the polymer. .

That is, when the coupling agent, which is a monomer, is decomposed by the filler, the coupling agent itself is oxidative, thereby inducing decomposition of the polymer or causing crosslinking. In addition, since compatibility with the base polymer occurs through the reaction, if the reaction does not occur, there is a disadvantage in that the compatibility is poor and the mechanical properties and the surface is poor.

The present invention is to prepare a coupling agent with a polymer compound instead of a monomer compound such as silane, silicone, and titanium, and to treat it with an inorganic filler or a reinforcing fiber to form one component of the polyamide resin composition. Compared with the improvement of adhesion and mechanical properties, good surface condition and compatibility.

The present invention provides a polyamide resin composition composed of 49.8 to 94.8% by weight of polyamide, 5 to 50% by weight of inorganic or reinforcing fibers treated with a polymer coupling agent of the following general formula, and 0.1 to 2% by weight of each of a heat and release agent. .

Where R is or N is 10 to 1000, n 'is 6, and n " is 10 to 1000.

The polymer coupling agent of the above-mentioned formula used in the present invention is very important and emulsifier such as sodium lauryl sulfate while mixing at 50 ° C. while mixing polyacrylamide having a molecular weight of about 200,000 to 100 parts by weight of water at a ratio of 8 to 12 parts by weight and stirring at 50 ° C. To 1.5 parts by weight, and 5 to 10 parts by weight of caprolactam (ε-Caprolactam) or 5 to 10 parts by weight of adipic acid and hexamethylene diamine in an equal mole with an initiator by stirring with nitrogen gas for about 6 hours while stirring The reaction is carried out and precipitated in methanol, followed by washing, separation and drying. The polymer coupling agent of the present invention prepared as described above is preferably used as an aqueous solution when the inorganic filler or reinforcing fiber is to be treated. The aqueous solution concentration of the coupling agent is preferably 0.1 to 80%.

The inorganic filler or reinforcing fiber to be treated with the polymer coupling agent of the present invention is not particularly limited, but inorganic fillers such as silicon dioxide, mica, silica gel, talc kaolinite, or reinforcing fibers such as glass fiber or carbon fiber are preferred. Polyamides are also not particularly limited, but nylon 6 and 66 resins are preferred. When the polymer coupling agent of the present invention is treated with an inorganic filler or a reinforcing fiber, the coupling agent is adsorbed around the filler or reinforcing fiber to increase the adhesion affinity between the filler or the reinforcing fiber and the polyamide, or the coupling agent is an inorganic filler or reinforcing fiber. Molecular reactions with the fibers at all cause the polymer coupling agent to behave similarly to polyamides in processing, resulting in better compatibility with the resin. This is because the conventional monomer coupling agent is bound only by the molecular reaction, whereas the polymer coupling agent of the present invention simultaneously reacts and adsorbs, thereby making the bond between the filler and the polymer stronger and superior in mechanical strength and compatibility. It becomes a factor. According to this principle, a method of treating the coupling agent on the surface of the filler or the reinforcing fiber may be, for example, a process as shown in FIG.

1, the reinforcing fiber 11 is passed through an acid solution 12 such as sulfuric acid or hydrochloric acid, dried 13 and plasma 14, and then passed through a 0.1 to 80% coupling agent aqueous solution 15. It is shown that the reinforcing fibers 11, which are fillers, are treated with a coupling agent by drying (16) and cutting (17). If the filler is a powder, the coupling agent is treated by simply dispersing the coupling agent through a nozzle on the filler, or by dipping and stirring the filler in a container containing a 5% coupling agent solution so that the coupling agent is adsorbed and reacted with the filler. In the composition of the present invention, since the heat-resistant agent and the release agent employed as part of the constituents are well known, special descriptions are omitted.

Hereinafter will be described in more detail through embodiments of the present invention.

[Production Example 1]

30 g of polyamide having a molecular weight of 200,000 was added to 300 ml of water, and 3 g of sodium lauryl sulfate was added with stirring, followed by complete stirring for 5 minutes, and nitrogen (N ₂ ) gas substitution at these 50 ° C. for 10 minutes, and 25 ml of caprolactam at 80 ° C. After adding the initiator (AIBN) while stirring at 250RPM and stirring for 6 hours, the mixture was precipitated in methanol, dried at 80 ° C for 1 hour, washed three times with water to separate unreacted polyacrylamide, and then methanol. Washed and dried at 80 ℃ 3 hours to prepare a polymer coupling agent.

[Production Example 2]

Glass-reinforced fibers prepared by treating the polymer coupling agent prepared according to Preparation Example 1 to glass-reinforced fibers were prepared.

Example 1

30% by weight of the glass-reinforced fiber treated with the coupling agent according to Preparation Example 2, 69.0% by weight of polyamide (N-66, 50AP: Long Franc), 0.2% by weight of heat resistant agent (Irganox B1171: Ciba geigy), release agent (Aluminium Stearte: Synpro) 0.3% by weight of twin screw compounding machine (250-265 ℃) homogeneously mixed at 250RPM and injection molding (265-280 ℃) to observe the mechanical properties and surface.

Example 2

20% by weight of the carbon-reinforced fiber treated with a coupling agent in Example 1, and 79.0% by weight of polyamide (N-66), the heat resistant agent and the release agent were the same as in Example 1.

Example 3

In Example 1, 10 wt% of the carbon-reinforced fiber treated with the coupling agent and 89.0 wt% of the polyamide (N-66) were used, and the heat resistant agent and the release agent were the same as those in Example 1.

Example 4

40 wt% of the cuffing agent-treated silica gel and 88.9 wt% of polyamide (N-66) were used in Example 1, and the heat and release agent were the same as in Example 1.

Comparative Example 1

Glass-reinforced fiber treated with silane was used, and the rest was the same as in Example 1.

Comparative Example 2

Using carbon-reinforced fiber treated with silane and the rest is the same as in Example 2.

Comparative Example 3

Using glass-reinforced fiber treated with silane and the rest is the same as in Example 3.

[Comparative Example 4]

Glass-reinforced fiber treated with titanium and the rest is the same as in Example 1.

[Comparative Example 5]

Example 1 is the same as using the glass-reinforced fiber without the coupling agent.

Comparative Example 6

40% by weight of silica gel coupled with silane was used, with the remainder as in Example 4.

Measurement of the mechanical properties of the composition according to the above Examples and Comparative Examples, according to ASTM standards, tensile strength ASTM D638, impact strength ASTM D256, elongation ASTM D638, heat deformation temperature ASTM D 648, flexural strength ASTM D 790, flexural modulus ASTM D 790 As a result, the surface and compatibility were determined by electron micrographs, and the following results obtained the mechanical properties and surface compatibility results of Table 1, and it can be seen that the mechanical properties and surface compatibility of the examples are superior to those of the comparative examples.

TABLE 1

Claims (2)

Polyamide resin characterized in that it is composed of 49.8 to 94.8% by weight of polyamide, 5 to 50% by weight of inorganic or reinforcing fibers treated with a coupling agent of the following general formula, 0.1 to 2% by weight of heat-resistant agent and 0.1 to 2% by weight of release agent Composition. Where R is or N is 10 to 1000, n 'is 6, and n " is 10 to 1000. The polyamide resin composition according to claim 1, wherein the concentration of the aqueous solution of the coupling agent treated on the inorganic material or the reinforcing fiber is 0.1 to 80%.