JPS6057464B2 - Polyamide resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyamide resin composition, and more specifically, the present invention relates to a polyamide resin composition, and more specifically, a polyamide resin obtained by reacting xylylene diamine and a linear aliphatic dicarboxylic acid (hereinafter referred to as xylylene diamine polyamide) and nylon. 66, inorganic filler,
This invention relates to a molding resin composition containing glass fiber and a polyolefin modified with an unsaturated organic acid.

The resin composition of the present invention can be easily molded by commonly used injection molding, extrusion molding, etc., and the molded product obtained from the composition of the present invention can be molded by physical, thermal, and chemical processes. It has excellent physical properties and dimensional stability.

Xylylene diamine polyamide, whose main component is meta-xylylene diamine, has the property of brittle fracture at room temperature in an unstretched state and has significantly poor impact resistance, but when glass fiber is added to it, These drawbacks are significantly improved, resulting in a molding material with superior chemical, thermal, and mechanical properties compared to conventionally known glass fiber-reinforced thermoplastic resin molding materials. (Japanese Patent Application Laid-Open No. 50-61449).
Furthermore, it is conceivable to incorporate an inorganic filler into this xylylenediamine-based polyamide composition containing glass fibers to reduce costs from the standpoint of industrial practical application.
When xylylene diamine polyamide is blended with glass fibers and inorganic fillers, molded products with excellent performance can be obtained. However, it has the disadvantage that it crystallizes more slowly than ordinary nylon 6, etc., so it cannot be used for injection molding, etc. During the molding process, the crystallization of the material poured into the mold is slow and it takes a long time to cool down, which is a drawback.In order to solve this problem, it has been seen that a small amount of nylon 66 is added as a crystal nucleating agent. (Japanese Patent Application Laid-Open No. 51-63860). However, when an inorganic filler is blended, problems arise in terms of physical properties, especially impact resistance. The inventors have discovered that glass fiber,
As a result of conducting studies to impart physically satisfactory properties to a xylylene diamine-based polyamide composition containing an inorganic filler, nylon 66, we found that unsaturated organic acid was added to this xylylene diamine-based polyamide composition. By blending modified polyolefin, we have succeeded in preventing the drop in impact strength caused by blending inorganic fillers and in reducing the anisotropy during molding due to the blending of glass fibers, resulting in the present invention. It is something. That is, the present invention uses xylylene diamine polyamide, nylon 66. glass fiber,
A resin composition comprising an inorganic filler and an unsaturated organic acid-modified polyolefin, the composition containing 5 to 3 glass fibers.
Rut amount%, inorganic filler is 10 to 7 weight%, unsaturated organic acid-modified polyolefin is 5 to 2 weight%, xylylenediamine polyamide is 24.5% by weight or less, and nylon 66 is 5% by weight or less. There are certain polyamide resin compositions.

The xylylene diamine polyamide in the present invention is
It is obtained by polycondensation reaction of metaxylylene diamine or a mixture of 60% or more metaxylylene diamine and 40% or less free xylylene diamine with a straight chain aliphatic dicarboxylic acid having 6 to 12 carbon atoms. be.

Among these, polyamides using adipic acid as the straight-chain aliphatic dicarboxylic acid are particularly desirable because they provide well-balanced molded products as molding materials. One of the purposes of the composition of the present invention is to obtain a molded product having desirable physical properties without using a large amount of the resin component, and from this point of view, the amount of the xylylene diamine polyamide is adjusted to 24. Although it is determined to be 5% by weight or less, if the amount is too small, not only will the desired performance not be obtained, but there will also be problems in molding, so if it is less than 2% by weight, it is not desirable.

In the present invention, the blending amount of nylon 66 is determined by moldability,
In other words, from the perspective of shortening the molding cycle time.

It appears to be effective over a wide range, but when considering the physical properties of the molded product, it is appropriate to use 5% by weight or less as mentioned above. However, if the amount is too small, the desired effect will not be achieved, so 1% by weight or more is desirable. There is no problem with the glass fiber as long as it is generally used for reinforcing resins, but chopped strands having a length of about 3T1rm are usually used, and the amount used is 5 to 3% by weight. be.

The inorganic fillers used in the present invention are commonly used powdered ones, such as talc, mica, calcium metasilicate, calcium carbonate, silica, calcium sulfate,
There are calcium sulfite, kaolinite, etc., and two or more of them may be used in combination, and the surface of the filler may be treated with a coupling agent, a surfactant, etc.

The blending amount of the filler is 10 to 7% by weight, preferably 30 to 5% by weight. Next, polyolefins modified with unsaturated organic acids will be described.

Polyolefins originally have poor affinity with inorganic fillers, and although surface treatments with inorganic fillers have been carried out to compensate for this, it is still not sufficient. However, the polyolefins used in the present invention, such as polyethylene Modified polyolefin, which is obtained by treating polypropylene, polypropylene, or a derivative thereof with an unsaturated organic acid, has an affinity for both xylylene diamine-based polyamide and an inorganic filler. It is possible to avoid a decrease in physical strength, especially impact strength. In the modification of polyolefin with an unsaturated organic acid, the concentration of the unsaturated organic acid is preferably about 0.5 to 5% by weight based on the polyolefin.
As the modification treatment method, a solution reaction in the presence of a peroxide initiator or a reaction by kneading during melt extrusion can be adopted.

Examples of the unsaturated organic acids used include fumaric acid, maleic acid, nadic acid, tetrahydrophthalic acid, methacrylic acid, and acrylic acid, and anhydrides of these are also effective. The amount of these unsaturated organic acid-modified polyolefins is determined in consideration of the physical properties of the molded product, and is 5 to 2.
% weight is preferred.

There are various methods for mixing the above-mentioned components, that is, xylylene diamine polyamide, nylon 66, glass fiber, inorganic filler, and unsaturated organic acid-modified polyolefin, and any method can be used. For example, each component is dry-blended simultaneously in a tumbler, melted in a screw extruder, extruded into strands, cooled and cut into appropriate lengths to make pellets, or xylylenediamine-based There is a method in which polyamide, nylon 66, an inorganic filler, and an unsaturated organic acid-modified polyolefin are mixed and extruded in advance as described above, and then glass fiber is added to the mixture and extruded again to form pellets.

Of course, in the extrusion kneading process of the composition of the present invention, additives such as flame retardants, heat stabilizers, lubricants, colorants, or ultraviolet absorbers may be added depending on the purpose, without adversely affecting the physical properties of the composition of the present invention. It is possible to reduce one or more types within a range that does not give the same effect.
The polyamide resin composition molded article of the present invention has particularly good mechanical properties such as tensile strength, bending strength, compressive strength, tensile elastic modulus, bending elastic modulus, compressive elastic modulus, and hardness, and heat distortion temperature. It has good thermal properties, low shrinkage during molding, and excellent dimensional stability.Furthermore, it has low water absorption, which is a characteristic of xylylenediamine polyamide, and excellent long-term creep properties. It is a high-quality molding material that maintains its properties without sacrificing its properties.

This will be explained in detail in Examples below.

In addition, "part" in this example represents a weight part. Example 1 24.5 parts of poly(methaxylylene adipamide) pellets with an average molecular weight of 18,000, 665 parts of nylon, chopped strand glass fiber (manufactured by Asahi Fiber Class Co., Ltd.,
CSO? A4O9C) 108V and polyethylene (F-41, manufactured by Nisseki Rexron Co., Ltd.) treated with methylnadic anhydride (weight ratio of methylnadic anhydride to polyethylene 0.5/100), 5 parts of modified polyethylene, calcium carbonate (Nitto Powder Chemical) NS-100) and 0.5 parts of lubricant were mixed, melt-kneaded using an extruder, extruded into strands, cooled in a water bath, cut into pellets, and dried to obtain a molding material. Ta.

The obtained pellets were injection molded at a cylinder temperature of 285°C and a mold temperature of 75°C to obtain test pieces, and their physical properties were determined by AS.
Measured according to TM.

The results are shown in the table. Example 2 The same composition as in Example 1 was used except that calcium carbonate in Example 1 was replaced with silica (Hi-Silica F2, manufactured by Toyo Ya Kaolin Co., Ltd.), and extrusion was carried out under the same conditions as in Example 1.
Made by injection molding.

The physical property measurement results are shown in the table. Example 3 The same composition as in Example 1 was used except that calcium carbonate in Example 1 was replaced with talc (manufactured by Tsuchiya Kaolin Co., Ltd., LM-R), and extrusion and injection molding were carried out under the same conditions as in Example 1. did.

The physical property measurement results are shown in the table. Example 4 24.5 parts of poly(methaxylylene adipamide) pellets having an average molecular weight of 18,300, 665 parts of nylon, w part of chopped strand glass fiber, and polyethylene (manufactured by Rexron Taishi Co., Ltd., F4l) were added to tetrahydrophthalic anhydride. 5 parts of modified polyethylene treated with acid (weight ratio of tetrahydrophthalic anhydride to polyethylene 0.5/100), 55 parts of calcium metasilicate (Wollastonite F-1, manufactured by Interbase), and 0.5 part of lubricant. Example 1
After extruding into pellets in the same manner as above, injection molding was performed.

The measurement results of physical property values are shown in the table. Example 5 664.5 parts of nylon and 3T length were added to the poly(methaxylylene adipamide) pellet having an average molecular weight of 18,000.
1 cup of fr1n slender strand glass, 5 parts of maleic anhydride-modified polyethylene (weight ratio of maleic anhydride and polyethylene 0.5/100), calcium carbonate mark and 0.5 part of lubricant were mixed. In the following, pelletization and molding were carried out in the same manner as in Example 1, and the physical properties were measured.

The results are shown in the table. Reference Example 1 24.5 parts of poly(methaxylylene adivamide) pellets having an average molecular weight of 18,100 were mixed with 665 parts of nylon, 7 calcium carbonate, and 0.5 part of a lubricant.
After extruding into pellets in the same manner as above, injection molding was performed.

The physical property measurement results are shown in the table. Reference Example 2 Poly(methaxylylene adipaminide) in Reference Example 1 was replaced with nylon 66, and extrusion and injection molding was carried out under the same conditions.

Claims (1)

[Claims] 1 xylylene diamine polyamide, nylon 66,
A resin composition consisting of glass fiber, an inorganic filler, and an unsaturated organic acid-modified polyolefin, the composition containing 5 to 30% by weight of glass fiber and 10 to 70% by weight of inorganic filler.
A polyamide resin composition comprising 5 to 20% by weight of unsaturated organic acid-modified polyolefin, 24.5% by weight or less of xylylene diamine polyamide, and 5% by weight or less of nylon 66.