JPH0465865B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to polyamide resin compositions. More particularly, the present invention relates to reinforced polyamide resin compositions containing inorganic mineral powders having improved practical properties. Polyamide resin has excellent mechanical and thermal properties and is widely used as a plastic molding material.
It is well known to blend glass fibers with inorganic mineral powders into polyamides in order to further enhance these properties. In general, inorganic mineral powder does not exhibit its effect even if it is mixed directly into plastic. To deal with this, a so-called coupling agent is applied to the surface of the inorganic mineral powder to combine the inorganic mineral powder with the organic plastic. A method has been adopted in which the effects of the combination are exerted by creating an affinity between the two. At this time, the coupling agent used here was classified according to its function depending on the type of plastic, and for polyamide, it was customary to use an aminosilane compound. However, reinforced polyamide resin compositions containing glass fibers and calcined kaolin powder treated with aminosilane compounds have excellent mechanical properties such as tensile strength and flexural modulus, as well as warp deformability, but they have excellent strength against falling weight impact. Because it is inferior to As a result of intensive studies aimed at improving the above-mentioned drawbacks, the present inventors surprisingly found that the effect is particularly great when glass fiber is blended with polyamide together with calcined kaolin powder treated with vinyltriethoxysilane. , led to the present invention. That is, the present invention is a polyamide composition comprising polyamide, glass fiber, and calcined kaolin powder, wherein the amount of glass fiber in the polyamide composition is 3 to 40% by weight, the amount of calcined kaolin powder is 5 to 50% by weight, The present invention relates to a reinforced polyamide resin composition characterized in that the amount of polyamide is 40% by weight or more, and the calcined kaolin powder is treated with vinyltriethoxysilane. The composition of the present invention will be explained below. The polyamide according to the present invention includes nylon 66, nylon 610, and nylon 612 obtained by condensation polymerization of diamine and dicarboxylic acid, nylon 6 and nylon 12 obtained by ring-opening polymerization of lactam, and self-polymerized ω-aminocarboxylic acid. Nylon 11 obtained by condensation, copolymers and blends thereof, etc. In particular, nylon 66 is preferred in terms of toughness and heat resistance. The glass fiber used in the present invention may be one that can be used as a reinforcing agent for polyamide, and there are no particular limitations on the shape of the glass fiber. In other words, it can be of any shape, from long fiber types (glass roping) to short fiber types (chopped strands, milled fibers). The calcined kaolin powder referred to in the present invention is obtained by firing kaolin clay at a temperature range of 350 to 1000° C. for several hours and then pulverizing it, and pulverizing it to an average particle size of 10 μm or less, particularly 2 μm or less is particularly preferable. The blending ratio of vinyltriethoxylan used in the present invention is per 100 parts by weight of calcined kaolin powder.
It ranges from 0.05 to 5 parts by weight, preferably from 0.3 to 3 parts by weight. If the blending ratio of vinyltriethoxy is less than 0.05 part by weight, the physical properties of the molded product obtained using this composition will not be sufficiently improved;
Even if the amount exceeds 1 part by weight, no particularly favorable effect can be obtained, and rather the physical properties of the molded article tend to deteriorate, which is not appropriate. A known method is employed for surface treating the calcined kaolin powder with vinyltriethoxysilane. For example, a method may be used in which a predetermined amount of calcined kaolin powder and vinyltriethoxysilane are directly charged into a Hensel mixer and mixed with high speed stirring. The amount of glass fiber used in the present invention is 3 to 40% by weight, preferably 5 to 35% by weight, based on the total composition. When the amount of glass fiber blended is less than 3% by weight, the properties of the reinforced polyamide resin composition are not improved to the extent expected;
If it exceeds this amount, the moldability of the composition will be significantly reduced. The amount of calcined kaolin powder used in the present invention is 5 to 50% by weight based on the total composition, preferably
It is 15-40% by weight. If the amount of calcined kaolin powder blended is less than 5% by weight, the effect of the blending will not be sufficient, and if it exceeds 50% by weight, melt mixing will be difficult and the moldability of the composition will be significantly reduced, so it is not practical. Not on point. The reinforced polyamide resin composition of the present invention is prepared by a conventional method for preparing polyamide resin compositions. For example, there is a method in which polyamide pellets, glass fibers, and calcined kaolin powder treated with vinyltriethoxysilane are premixed, the mixture is fed to an extruder, melted and kneaded, and then cooled and pelletized. The reinforcing composition of the present invention may contain other components, such as pigments, dyes, heat resisters, oxidative deterioration inhibitors, lubricants, flame retardants, antistatic agents, mold release agents, as long as they do not impair its moldability and physical properties. Plasticizers, other resin polymers, etc. can be added. The reinforced polyamide resin composition of the present invention has improved practical properties such as excellent mechanical properties such as tensile strength and flexural modulus, less warpage, and improved falling weight impact strength. It is useful as a material for automobile parts that require strict reliability as a plastic material, particularly for cylinder head covers, trunk axle rear covers, radiator tanks, heater tanks, etc. The present invention will be explained in further detail with reference to Examples below. The physical properties of the test pieces described in Examples and Comparative Examples were measured in accordance with the following method. (1) Tensile test: ASTM D638 (2) Bending test: ASTM D790 (3) Heat distortion temperature: ASTM D643 (4) Falling weight impact test: JIS K7211 (5) Warp deformation: Small flat plate (130 x 110 ×
3mm) was used. Place the formed small plate on a flat surface,
Local gaps caused by warping were observed, and the degree of the gap was evaluated as A, B, and C in descending order. Example 1 Nylon 66 with a relative viscosity of 2.80, 60 kg, glass fiber (Asahi Fiberglass MA416) 10 kg and vinyltriethoxysilane (Shin-Etsu Silicon KBE1003)
600g surface-treated calcined kaolin (ENGEL
Satintone No. 1) manufactured by HARD Co., Ltd. (30 kg) was premixed in a V-type blender, and then melt-blended at 290°C using a 70% single-screw extruder to obtain pellets of a reinforced polyamide resin composition. The obtained pellets were molded into test pieces for measuring physical properties using an injection molding machine at a temperature of 290°C, and various physical properties were evaluated. The results are shown in Table 1. Examples 2 to 3 Test pieces for measuring physical properties were molded in the same manner as in Example 1, except that the proportions of nylon 66, glass fiber, and silane-treated calcined kaolin were changed as shown in Table 1, and various physical properties were evaluated. did. The results are shown in Table 1. Comparative Examples 1-2 Test pieces for measuring physical properties were molded in exactly the same manner as in Example 1, except that the proportions of nylon 66, glass fiber, and silane-treated calcined kaolin were changed as shown in Table 1, and various physical properties were evaluated. did. The results are shown in Table 1. Comparative Example 3 γ-Aminopropyltriethoxysilane (manufactured by Nippon Unicar:
A test piece for measuring physical properties was molded in the same manner as in Example 1 except that A-1100) was used, and various physical properties were evaluated.
The results are shown in Table 1. Comparative example 4 Nylon 66 with a relative viscosity of 2.80, 60 kg and vinyltriethoxysilane (Shin-Etsu Silicon KBE1003) 800
Calcined kaolin surface-treated with ENGEL
A test piece for measuring physical properties was molded in exactly the same manner as in Example 1, except that the glass fiber was not used, and the various physical properties were evaluated. The results are shown in Table 1. Comparative Example 5 γ-Aminopropyltriethoxysilane (manufactured by Nippon Unicar:
A test piece for measuring physical properties was molded in the same manner as in Comparative Example 4 except that A-1100) was used, and various physical properties were evaluated.
The results are shown in Table 1.

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Claims (1)

[Scope of Claims] 1. A polyamide resin composition comprising polyamide, glass fiber, and calcined kaolin powder, wherein the amount of glass fiber in the composition is 3 to 40% by weight, and the amount of calcined kaolin powder is 5 to 50% by weight. 1. A reinforced polyamide resin composition, characterized in that the amount of polyamide is 40% by weight or more, and the calcined kaolin powder is treated with vinyltriethoxysilane. 2. The reinforced polyamide resin composition according to claim 1, wherein the reinforced polyamide resin composition is a material for automobile parts.