JPS62218445A - Glass fiber-reinforced polyamide composition - Google Patents

Abstract

PURPOSE:To obtain the titled compsn. which has good mechanical characteristics and a high heat distortion temp., hardly causes lowering in physical properties in a high-temperature atmosphere and has improved resistance to warpage and deformation, by blending a crystalline polyamide with a specified arom. polyamide, glass fiber and talc. CONSTITUTION:A compsn. consists of 100pts.wt. polyamide mixture of 10-90pts. wt. crystalline polyamide (A) and 90-10pts.wt. arom. polyamide (B) obtd. by polycondensing salts of terephthalic acid and isophthalic acid with hexamethylene-diamine and 20-100pts.wt. glass fiber (C). As the crystalline polyamide (A), nylon 46 and nylon 66 are particularly preferred from the viewpoint of heat resistance. The arom. polyamide may be a copolymer with other polyamide-forming monomer. Talc (D) having a surface treated with a silane coupling agent is preferred.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a polyamide resin composition, specifically, it has high mechanical properties and heat distortion temperature, less deterioration of physical properties in high temperature atmosphere, and improved warp deformation. The present invention relates to a glass fiber-reinforced polyamide resin composition that has practical characteristics that are excellent in chemical resistance.

[Prior art] Materials made of nylon 6 and nylon 66 resins reinforced with glass fiber have excellent toughness, heat resistance, and chemical resistance and are used as materials for automobiles and electrical parts, but due to the anisotropy of molding shrinkage, There was a problem that distortion occurred when assembling parts or caulking with metal parts, resulting in cracks and joint defects. Furthermore, there were essential drawbacks such as deterioration of physical properties in high-temperature atmospheres. A known method to solve these problems is to blend a large amount of inorganic ore powder to reduce the anisotropy of molding shrinkage and improve warpage. Improvements are insufficient;
Deterioration of mechanical properties and deterioration of physical properties under high temperature atmosphere could not be avoided. There is also a method to improve warp by using a non-quality polyamide containing aromatic rings instead of nylon 6 or nylon 86 resin and reinforcing it with glass fiber.
Although the warpage can be improved, the heat distortion temperature is low, and furthermore, the physical properties rapidly deteriorate at high temperatures.

In other words, it has excellent mechanical properties, a high heat distortion temperature, improved physical property deterioration at high temperatures, and less warp deformation.
Furthermore, no glass fiber-reinforced polyamide composition having excellent chemical resistance is known.

[Problems to be Solved by the Invention] The present inventors have discovered a material that has excellent mechanical properties, a high heat distortion temperature, less rapid deterioration of physical properties in high-temperature atmospheres, improved warp deformation, and improved chemical resistance. As a result of studying excellent glass fiber reinforced polyamide compositions, we found that a composition consisting of crystalline polyamide, polyamide having a specific aromatic ring, glass fiber, and a specific small amount of inorganic ore powder would meet the above purpose, and we have published this book. Completed the invention.

[Means and effects for solving the problems] The present invention provides an aromatic polyamide obtained by polycondensing 10 to 90 parts by weight of crystalline polyamide [A] and salts of terephthalic acid, isophthalic acid, and hexamethylene diamine. [B] 100 parts by weight of mixed polyamide consisting of 90 to 10 parts by weight, glass m fiber [0120 to 100 parts by weight, talc [D] 0.2 to 15 parts by weight
Parts by weight of glass m-fiber reinforced polyamide compositions.

The crystalline polyamide [A] of the present invention is nylon 4G, nylon 6B, nylon 69, nylon 610, nylon 6
12, nylon 6, nylon 12, nylon 11, blends thereof, or copolymers thereof.

In particular, nylon 46 and nylon 68 are preferred from the viewpoint of heat resistance.

Aromatic polyamide [B] contains 70 to 30% by weight of terephthalic acid, preferably 60 to 40% by weight, and 30% by weight of isophthalic acid.
It is a polyamide obtained by polycondensing a salt of a dicarboxylic acid consisting of ~70% by weight, preferably 40 to 60% by weight, and hexamethylene diamine. Moreover, a copolymer with other polyamide-forming monomers may be used as necessary.

The mixed polyamide of the present invention is crystalline polyamide [A] 1
0 to 80 parts by weight, preferably 30 to 70 parts by weight, and 90 to 10 parts by weight, preferably 70 parts by weight of aromatic polyamide [B]
~30 parts by weight.

If the amount of crystalline polyamide [A] is less than 10 parts by weight with respect to 100 parts by weight of the mixed polyamide consisting of crystalline polyamide [A] and aromatic polyamide [B], mechanical failure will occur even if reinforced with glass mIm. The physical properties are not sufficient, the heat deformation temperature is low, and the reduction in physical properties under high temperature atmosphere is not sufficiently improved.

Moreover, if the crystalline polyamide [A] is more than 90 parts by weight,
The effect of improving warp deformation is not sufficient, and the physical properties deteriorate significantly in a high temperature atmosphere.

The glass m-fiber [0] used in the present invention is a commonly used glass m-fiber and is not particularly limited. The blending amount can be selected arbitrarily depending on the purpose of the reinforced resin, but usually,
20 to 1 part by weight of mixed polyamide consisting of crystalline polyamide [A] and aromatic polyamide [B]
00 parts by weight is added. If the amount of glass m-fiber [C] is less than 20 parts by weight, the reinforcing effect will not be sufficient, and if it is more than 100 parts by weight, there will be problems with moldability, and the effect of improving mechanical properties will be too low considering the amount. is small.

The talc [D] used in the present invention is a commonly used talc and is not particularly limited, but it is preferably surface-treated with a silane coupling agent. The amount of talc [D] to be blended is 0.2 to 15 parts by weight based on 100 parts by weight of the mixed polyamide consisting of crystalline polyamide rA] and aromatic polyamide [B]. Preferably, crystalline polyamide [A] and aromatic polyamide [
It is preferable to change the blending ratio of B]. Talc [D
] If the amount is less than 0.2 parts by weight, the heat distortion temperature will not rise sufficiently, and if it is more than 15 parts by weight, the mechanical properties will deteriorate despite the improvement in mold shrinkage anisotropy. Furthermore, by incorporating an appropriate amount of talc [D], the heat deformation temperature can be increased, and the effect of improving the crushing impact strength can also be exhibited.

There are no particular restrictions on the method for producing the composition of the present invention, but usually crystalline, polyamide [A], aromatic polyamide [B]
, glass fiber [C], and talc [D] are triblended, and then melt-kneaded using a commonly used single-screw or twin-screw extruder.

The glass fiber-reinforced polyamide composition obtained in this way has high mechanical properties and heat distortion temperature, less deterioration of physical properties in high-temperature atmospheres, improved warp deformation, and has practical properties such as excellent chemical resistance. It is particularly useful for automobile parts materials that require high reliability. Further, other resin polymers, plasticizers, lubricants, colorants, antioxidants/thermal stabilizers, ultraviolet absorbers, flame retardants, etc. may be added within a range that does not impair the purpose of the present invention.

[Example] Hereinafter, the present invention will be explained in detail with reference to Examples.

The physical properties of the molded products in each example were measured as follows.

- Rigidity retention The flexural modulus was measured at 23°C and 120°C according to ASTM-D-790, and expressed as a percentage of 23°C.

・Heat distortion temperature (HDT) According to ASTM-D-848, high load 1B, f1kg/
Measured in cm2.

・Impact resistance Measured according to ASTM-D-25El.

・Falling impact resistance tip is 4.5mmR, diameter 9m+sφ, length 100mm
flat metal rod (130mm x 130mm x 3
mm), and using a device that drops a weight from a certain height, strike 18 points at equal intervals on one flat plate, with a failure rate of 50%.
The height was determined, and the product of the weight and height was taken as the impact resistance.

・Antifreeze resistance A 50% aqueous solution of antifreeze (Nissan genuine long life coolant) was heated to 140°C, and the tensile strength was measured after immersing the test piece in it for 100 hours.The tensile strength after 5 hours of immersion was measured. Expressed as a percentage of

・After heating the oil-resistant engine oil (Toyota genuine motor oil Castle Green Super SD) to 100°C and immersing the test piece in it for 500 hours, the tensile strength was determined by ASTM-
Measured according to D-838.

・Metal halide resistance A test piece in a saturated water absorption state is kept bent under constant stress.
After applying a 30% by weight aqueous calcium chloride solution and leaving it in a hot air oven at 100° C. for 2 hours, the surface condition of the test piece was observed.

(-) indicates no cracks.

As the value increases from (+) to (-++), more cracks occur.

Box-shaped (height 6ca, short side 8c+a, long side 1
2c+m) was molded, and the degree of bending of the edges caused by warping was observed and evaluated as A, B, and C in descending order.

Reference example 1 Terephthalic acid 32.2kg, isophthalic acid 32.2kg
and hexamethylene diamine 45 kg and water 109.4 kg
kg was fed into a preheated reactor, and salt formation and concentration were performed at 120°C for 5 hours.

Supplied to an autoclave maintained at 230°C and heated under pressure for 3
The temperature was raised to 10°C. At this time, the maximum pressure is 18kg/cm
After reacting at No. 2 for 2 hours, the pressure was lowered, the autoclave was discharged, and the mixture was cooled and solidified to form pellets to obtain an aromatic polyamide.

Example 1 85 kg of nylon 66 with a relative viscosity of 2.80 and Reference Example 1
35 kg of aromatic polyamide and talc (C commercially available from Tatsumori)
, R58002) in a tumbler, and further blended with 70 kg of commercially available short glass fibers.
It was extruded and granulated at an extrusion temperature of 300°C to obtain a reinforced polyamide composition. The obtained reinforced polyamide composition was molded using an injection molding machine at a temperature of 280°C to obtain a molded piece for measuring physical properties, and various physical properties were measured. The results are shown in Table 1.

Example 2 A reinforced polyamide composition was obtained in the same manner as in Example 1, except that 80 kg of nylon 68 and 40 kg of the aromatic polyamide of Reference Example 1 were used, and various physical properties were measured. The results are shown in Table 1.

Example 3 50 kg of nylon 66, 50 kg of the aromatic polyamide of Reference Example 1, 10 kg of talc, and 85 kg of glass fiber,
A reinforced polyamide composition was obtained in the same manner as in Example 1, and various physical properties were measured. The results are shown in Table 1.

Example 4 A 1-reinforced polyamide composition was obtained in the same manner as in Example 1 using 30 kg of nylon 66, 70 kg of the aromatic polyamide of Reference Example 1, 15 kg of talc, and 130 kg of glass fiber.
Various physical properties were measured. The results are shown in Table 1.

Example 5 50 kg of nylon 4B, 50 kg of the aromatic polyamide of Reference Example 1, talc IQ kg, and 85 kg of glass fiber,
A reinforced polyamide composition was obtained in the same manner as in Example 1, and various physical properties were measured. The results are shown in Table 1.

Comparative Example 1 A reinforced polyamide composition was obtained in the same manner as in Example 1 using 85 kg of nylon 66, 5 kg of the aromatic polyamide of Reference Example 1, 5 kg of talc, and 70 kg of glass fiber, and various physical properties were measured. The results are shown in Table 1.

Comparative Example 2 A reinforced polyamide composition was obtained in the same manner as in Example 1 using 15 kg of nylon 8B, 35 kg of the aromatic polyamide of Reference Example 1, 35 kg of talc, and 40 kg of glass fiber.
Various physical properties were measured. The results are shown in Table 1.

Comparative Example 3 A reinforced polyamide composition was obtained in the same manner as in Example 1 using 50 kg of nylon 66, 50 kg of the aromatic polyamide of Reference Example 1, and 75 kg of glass m-fiber without blending talc, and various physical properties were measured. The results are shown in Table 1 Comparative Example 4 A reinforced polyamide composition was obtained in the same manner as in Example 1 using 50 kg of nylon C6, 50 kg of the aromatic polyamide of Reference Example 1, 10 kg of inorganic ore powder kaolin, and 75 kg of glass m fiber, Various physical properties were measured. The results are shown in Table 1.

[Effect of the invention] The glass fiber reinforced polyamide composition of the present invention has excellent mechanical properties,
It has high thermal deformation temperature, less deterioration of physical properties in high temperature atmosphere, improved warp deformation, and excellent chemical resistance, making it suitable for automotive parts materials that require high reliability. Can be used.

Claims (1)

[Claims] Aromatic polyamide [B] obtained by polycondensing 10 to 90 parts by weight of crystalline polyamide [A] and a salt of terephthalic acid, isophthalic acid, and hexamethylene diamine [B] 90 to 90 parts by weight
100 parts by weight of mixed polyamide consisting of 10 parts by weight, 20 to 100 parts by weight of glass fiber [C], 0.2 parts by weight of talc [D]
-15 parts by weight of a glass fiber reinforced polyamide composition.