JPH0741669A - Polyamide resin component - Google Patents

Abstract

PURPOSE:To obtain a polyamide resin composition for molding, having excellent heat resistance and reduction in molding cycle. CONSTITUTION:100 pts.wt. of a polyamide resin obtained from a mixed xylylenediamine composed of 25-45mol% of p-xylylenediamine and 75-55mol% of m-xylylenediamine is mixed with 0.1-10 pts.wt. of talc as a crystal nucleating agent to give a polyamide resin composition for molding.

Description

Detailed Description of the Invention

[0001]

The present invention relates to mechanical properties, heat resistance properties,
The present invention relates to a molding polyamide resin composition having excellent chemical and physical properties and molding properties.

[0002]

2. Description of the Related Art Polyamide resins have chemical resistance and excellent mechanical strength.
It has been widely used in fields such as A equipment, but on the other hand,
There is also a demand for higher heat resistance. Among polyamide resins, a polyamide resin obtained from metaxylylenediamine and α, ω-linear aliphatic dibasic acid (hereinafter referred to as MX nylon) is compared with other polyamide resins such as polyamide 6 and polyamide 66. High mechanical strength,
It has elastic modulus and low water absorption.

However, since MX nylon has a slow crystallization rate, it has a long molding cycle and is disadvantageous in terms of molding cost. It is known to knead polyamide 66 as a method for improving the crystallization rate of MX nylon (Japanese Patent Publication No. 54-32458). However, kneading the polyamide 66 may cause inconveniences in terms of an increase in water absorption and a decrease in mechanical strength.

[0004]

DISCLOSURE OF THE INVENTION The present invention has improved the heat resistance, which was insufficient in the above-mentioned conventional techniques, and increased the crystallization rate of xylylene adipamide without using polyamide 66 to form a molded product. The purpose is to improve sex.

[0005]

Means for Solving the Problems As a result of intensive investigations by the present inventors, as a raw material, a specific mixed xylenediamine and α, ω were mixed.
-We have found that the resin composition obtained by using the straight-chain aliphatic dibasic acid has excellent moldability and heat resistance, and reached the present invention.

That is, the present invention provides 25-45 mol% of para-xylylenediamine and 75-5 of meta-xylylenediamine.
Polyamide resin 100 obtained from mixed xylylenediamine consisting of 5 mol% and α, ω-linear aliphatic dibasic acid
A molding polyamide resin composition containing 0.1 to 10 parts by weight of talc as a crystal nucleating agent, and 25 to 45 mol% of paraxylylenediamine and 75 to 55 mol% of metaxylylenediamine, based on parts by weight. 0.1 to 10 parts by weight of talc as a crystal nucleating agent and 100 to 150 parts by weight of a polyamide resin obtained from mixed xylylenediamine and an α, ω-linear aliphatic dibasic acid, and a fibrous filler 10 to 150
The present invention relates to a polyamide resin composition for molding formed by blending parts by weight.

The polyamide resin (hereinafter referred to as MP nylon) obtained from the mixed xylylenediamine and the α, ω-linear aliphatic dibasic acid used in the present invention is obtained from the following diamine and dicarboxylic acid. It is a polyamide resin.

The xylylenediamine used as a raw material for polyamide is 25 to 45 mol% of para-xylylenediamine.
And a diamine mixture containing 75 to 55 mol% of meta-xylylenediamine. The ratio of paraxylylenediamine is above 2
If it is less than 5 mol%, a sufficient crystallization rate cannot be obtained, and if it exceeds 45 mol%, the melting point becomes too high, which causes problems during polymerization and molding or extrusion.

The α, ω-linear aliphatic dibasic acid used as a polyamide raw material is an α, ω-linear aliphatic dibasic acid having 4 to 20 carbon atoms, such as adipic acid, sebacic acid, suberic acid and dodecane. Examples include diacid and eicodioic acid.
Among the MP nylons, adipic acid is particularly preferable among the above α, ω-straight chain aliphatic dibasic acids in consideration of the balance of moldability and molded product performance.

The talc used as a crystal nucleating agent during injection molding in the present invention is preferably in powder form, and its average particle size is preferably 50 μm or less, more preferably 20 μm.
m or less. If the outer diameter of talc exceeds 50 μm, dispersibility may be inconvenient and the expected effect may not be obtained.

In the present invention, a fibrous filler may be further mixed with a resin composition comprising a polyamide resin and talc for use. As the fibrous filler, glass fiber, potassium titanate or calcium sulfate whiskers,
Carbon fibers and alumina fibers can be used. The preferred blending amount of the fibrous filler is 10 to 150 parts by weight of the fibrous filler with respect to 100 parts by weight of the polyamide resin of the present invention. If the content of the fibrous filler is less than 10 parts by weight, a sufficient reinforcing effect cannot be obtained, and if it exceeds 150 parts by weight, molding or extrusion will be inconvenient.

In addition, one or more additives, such as powdery, granular and flake-like inorganic fillers, flame retardants, antistatic agents, lubricants, plasticizers, and oxidation agents, as long as they do not deteriorate the physical properties. It is also possible to use a stabilizer against deterioration by heat, heat, and ultraviolet rays.

[0013]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" means "parts by weight" unless otherwise specified. The evaluation was based on the following method. 1) Deflection temperature under load: ASTM D648 2) Bending test: ASTM D790 3) Crystallization rate From a 0.8 mm-thick test piece molded under the injection conditions described in Examples and Comparative Examples, a 1 cm x 1 cm test piece Is cut out and sandwiched between two cover glasses.
After melting at 0 ° C. and Comparative Examples 1 and 2 at 270 ° C. for 3 minutes, 1
It is immersed in a crystallization bath adjusted to 30 ° C., the polarization compensation voltage with respect to the standing time is measured, the time required to reach a half of the constant voltage is the half crystallization time, and the reciprocal thereof is the crystallization speed ( Kotaki Manufacturing Polymer Crystallization Rate Measuring Device,
Model: MK-701 used).

4) Water Absorption Rate Using an ASTM D638 tensile test piece molded under the above conditions, the test piece is immersed in boiling water, the measurement is repeated until the weight does not change, and the reached weight percentage is saturated water absorption. And rate.

Example 1 A mixed diamine consisting of 30 mol% para-xylylenediamine and 70 mol% meta-xylylenediamine was mixed in advance,
The solution is dissolved and added dropwise to the molten adipic acid in the reaction vessel, and the condensation reaction is proceeded by stirring while maintaining the temperature of the reaction vessel so as to always exceed the melting point of the product.

After the completion of dropping, stirring and reaction are continued until a predetermined viscosity is reached, and when the predetermined viscosity is reached, the mixture is taken out and pelletized. For 100 parts of MP nylon synthesized as above, talc (average particle size 1.6 μm) 4
Part, and 100 parts of glass fiber are mixed, and a vent type single-screw extruder (manufactured by Tanabe Plastics Machine, model: VS40)
After melt-kneading at a cylinder temperature of 290 ° C. using
Water cooled and pelletized.

The obtained pellets were subjected to ASTM using an injection molding machine under the conditions of a cylinder temperature of 290 ° C., a mold temperature of 130 ° C., and an injection pressure of 1000 kgf / cm ^2.
Test pieces for D790 bending test and D638 tensile test and 0.8 mm UL certified test piece were molded.
The compounding ratios of the components in the composition and the evaluation results are summarized in Table 1. In Example 1, a high deflection temperature under load, a high crystallization rate, and a low saturated water absorption rate were obtained.

Example 2 40 mol% of para-xylylenediamine and 60 mol% of meta-xylylenediamine were mixed in advance and dissolved, and were successively added dropwise to the molten adipic acid in the reaction vessel, and the melting point of the product was always exceeded. In this way, stirring is performed while maintaining the reaction kettle temperature, and the condensation reaction proceeds. After the completion of dropping, stir until reaching the predetermined viscosity,
The reaction is continued, and when it reaches a predetermined viscosity, it is taken out and pelletized. MP nylon 10 synthesized as above
4 parts of talc (average particle size: 1.6 μm) and 100 parts of glass fiber were mixed with 0 part, and melted at a cylinder temperature of 290 ° C. using a vent type single-screw extruder (VS40 made by Tanabe Plastics Machine). After kneading, the mixture was cooled with water and pelletized.

The obtained pellets were molded into a test piece for ASTM D790 bending test, a test piece for D638 tensile test and a 0.8 mm UL certified test piece under the same conditions as in Example 1 using an injection molding machine. The compounding ratios of the components in the composition and the evaluation results are summarized in Table 1. In Example 2, a high deflection temperature under load and a high crystallization rate were obtained, and the saturated water absorption rate was also low.

Comparative Example 1 MX Nylon (Polymeta-xylylene adipamide) 90
And 100 parts of polyamide resin obtained by mixing 10 parts of polyamide 66 with 100 parts of polyamide 66, talc (average particle size 1.6 μm)
Vent type single-screw extruder (manufactured by Tanabe Plastics Machinery, model: VS4) by blending 4 parts and 100 parts of glass fiber
0) was melt-kneaded at a cylinder temperature of 270 ° C., then water-cooled and pelletized. Using an injection molding machine, the obtained pellets are used at a cylinder temperature of 270 ° C. and a mold temperature of 1
Test pieces for ASTM D790 bending test, D638 tensile test, and 0.8 mm UL certified test piece were molded under the conditions of 30 ° C. and injection pressure of 1000 kgf / cm ² . The compounding ratios of the components in the composition and the evaluation results are summarized in Table 1. In Comparative Example 1, the deflection temperature under load was lower, the crystallization rate was lower, and the saturated water absorption rate was higher than those of Examples 1 and 2.

Example 1 Example 2 Comparative Example 1 Blending ratio of components Polyamide MXD6 --- 90 Polyamide 66 --- 10 Polyamide MP6 ^{* 1} 100--Polyamide MP6 ^* 2--100-Glass fiber 100 100 100 Talc 4 4 4 Load Deflection temperature (° C.) 251 259 235 Bending strength (MPa) 20 ° C. 360 340 350 350 ° C. 240 220 220 190 Flexural modulus (GPa) 20 ° C. 17 17 16 100 ° C. 11 11 18 Crystallization rate (1 / s) 0.1. 34 0.56 0.17 Saturated water absorption (%) 2.9 2.7 3.4 * 1) Polyamide MP6 has a blending molar ratio of paraxylylenediamine and metaxylylenediamine of 30:70 * 2) Polyamide MP6 has a mixing molar ratio of para-xylylenediamine and meta-xylylenediamine of 40:60.

[0022]

The mixed xylylenediamine of the present invention and α,
A resin composition composed of a talc and a polyamide resin obtained from an ω-linear aliphatic dibasic acid has excellent heat resistance, moldability, and water absorption properties, and has a high temperature range that is not practical with conventional polyamides. It can be applied to molded products used in.

Claims (2)

[Claims] 1. A polyamide resin obtained from a mixed xylylenediamine composed of 25 to 45 mol% of paraxylylenediamine and 75 to 55 mol% of metaxylylenediamine and an α, ω-linear aliphatic dibasic acid. A molding polyamide resin composition obtained by mixing 0.1 to 10 parts by weight of talc as a crystal nucleating agent with respect to 100 parts by weight. 2. A polyamide resin obtained from a mixed xylylenediamine consisting of 25 to 45 mol% of paraxylylenediamine and 75 to 55 mol% of metaxylylenediamine and an α, ω-linear aliphatic dibasic acid. A molding polyamide resin composition obtained by mixing 0.1 to 10 parts by weight of talc as a crystal nucleating agent and 10 to 150 parts by weight of a fibrous filler with respect to 100 parts by weight.