JPH02167366A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain a polyamide resin composition, excellent in surface appearance, heat resistance and mechanical strength by blending nylon-4,6 resin with a specific reinforcing material and nylon-6 resin and/or nylon-6,6 resin. CONSTITUTION:A resin composition obtained by blending 100 pts.wt. total amount of (A) 90-40wt.% nylon-4,6 resin having 0.8-1.90 intrinsic viscosity and (B) 10-60wt.% nylon-6 and/or nylon-6,6 resin having 0.8-1.60 intrinsic viscosity with (C) 5-50 pts.wt. fibrous reinforcing material (e.g. glass fiber) and (D) 5-100 pts.wt. powdery reinforcing material (e.g. calcined kaolin, wollastonite or mica).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a polyamide resin composition, and more particularly to a polyamide resin composition having excellent surface appearance, heat resistance, and mechanical strength.

[Prior art] Nylon-4 made from tetramethylene diamine or its functional derivative and adipic acid or its functional derivative
, 6 resins have been known for a long time.

This nylon-4,6 resin has excellent mechanical strength such as tensile strength, bending strength, and impact strength, as well as excellent heat resistance and sliding properties, so it is considered to have great utility as a useful engineering plastic. It is considered.

Nylon-4,6 resin is reinforced with a fibrous reinforcing material such as glass fiber in order to significantly increase its utility value. This increases mechanical strength and heat resistance, but on the other hand, disadvantages such as warp deformation and poor molded appearance due to anisotropy are observed. On the other hand, if a powdered reinforcing material such as calcined kaolin or wollastonite is used, drawbacks such as anisotropy and poor molded appearance can be overcome, but the effects of improving mechanical strength and heat resistance are insufficient.

In order to obtain a composition that combines the advantages of these two types of reinforcement, attempts to use a combination of fibrous reinforcement and powdered reinforcement have been widely carried out with nylon-6 and nylon-6,6 resins.
A composition with well-balanced mechanical strength, thermal properties, and dimensional stability was obtained, but similar effects were obtained with nylon-4 and 6.
It is also recognized in resins.

However, when two types of reinforcing materials are used in combination with nylon-4,6 resin, poor molded appearance is observed, and furthermore, there are drawbacks in that the impact strength is lower than when each reinforcing material is used alone. These drawbacks significantly impair its utility as a molding material.

[Object of the invention] The present invention was made against the background of the above-mentioned circumstances, and
The purpose is to maintain the excellent properties of nylon-4,6 resin that uses a combination of fibrous reinforcement and powdered reinforcement, while improving the poor molded appearance and reduction in impact strength.

[Structure of the Invention] The present inventors have maintained the excellent properties of nylon-4,6 resin reinforced by a combination of fibrous reinforcing material and powdered reinforcing material, while improving the poor molded appearance and decrease in impact strength. As a result of extensive research, it has been found that when a specific amount of nylon-6 and/or nylon-6,6 resin is blended with nylon-4,6 resin reinforced with fibrous reinforcement and powdered reinforcement, the tensile strength is increased.

The present invention was achieved based on the finding that poor molded appearance and decrease in impact strength can be improved without substantially impairing mechanical strength expressed by bending strength or heat resistance expressed by heat distortion temperature.

That is, the present invention provides (A) nylon-4,6 resin.

Consisting of (B) nylon-6 and/or nylon-6,6 resin, (C) 1 mm shaped material and (D) powdered reinforcing material, the weight % ratio of component (A) and component (B) is 90.
~40: 10 to 60, and (A), (B)
This is a polyamide resin composition characterized in that the component (C) is 5 to 50 parts by weight and the component (D) is 5 to 100 parts by weight per 100 parts by weight of the total components.

The present invention will be explained in detail below.

The nylon-4゜6 resin as component (A) used in the present invention is a polyamide obtained by a condensation reaction using adipic acid or a functional derivative thereof as an acid component and tetramethylene diamine or a functional derivative thereof as an amine component. Although this is the main target, a part of the adipic acid component or tetramethylenediamine component may be replaced with another copolymer component.

Preferred embodiments of the method for producing nylon-4,6 resin are disclosed in JP-A-56-149430 and JP-A-56-1494.
It is described in Publication No. 31.

The intrinsic viscosity of the nylon-4,6 resin used in the present invention is 0.80 when measured at 35°C using m-cresol.
~1.90, and more preferably in the range of 0.90 to 1.50.

When a nylon-4,6 resin with an intrinsic viscosity exceeding 1.90 is used, the fluidity of the composition is insufficient, and the resulting molded product not only loses its glossy appearance but also has mechanical and thermal This is not preferable because it increases the variation in the physical properties. On the other hand, if the intrinsic viscosity is less than 0.80, the mechanical strength of the composition becomes low.

The nylon-6 resin used as the component (B) in the present invention is polycaproamide and a polyamide whose main constituent units are caproamide units, and is usually produced using the σ-melt polymerization method, that is, the raw material ε-caprolactam is charged into a polymerization tank together with water. , can be obtained by a method of polymerizing at a temperature of about 250 to 300° C. under normal pressure, increased pressure, or reduced pressure.

The preferable intrinsic viscosity of the nylon-6 resin is 0.80 to 1.60, more preferably 0.90 to 1.40, at 35°C using m-cresol as a solvent.

In addition, the nylon-6 component (B) used in the present invention
, 6 resin is polyhexamethylene adipamide.

It is a polyamide whose main constituents are hexamethylene adipamide units, and is produced using the usual melt polymerization method, i.e., substantially equimolar salts of hexamethylene diamine and adipic acid as raw materials are charged into a polymerization tank together with water, and the temperature is heated at 250 to 300°C. It can be obtained by a method in which polymerization is carried out at a certain temperature under normal pressure, increased pressure, or reduced pressure. The preferable intrinsic viscosity of the nylon-6,6 resin is 35°C using m-cresol as a solvent.
is 0.80 to 1.60, and furthermore 0.90 to 1.60.
It is 1.40.

The ratio of component (A) and component (B) in the present invention is 90-40:10-60 in weight percent. When the proportion of component (B) is 10% by weight without swirling, the improvement effect on poor molded appearance and drop in impact strength of nylon-4,6 resin reinforced with fibrous and powdered reinforcing materials is small;
If it exceeds % by weight, the molded appearance and impact strength will be improved, but the heat resistance expressed by the heat distortion temperature will decrease, which is not preferable.

Examples of the fibrous reinforcing material of component (C) used in the present invention include glass fiber, aramid fiber, carbon fiber, steel fiber, asbestos, ceramic fiber, potassium titanate whisker, and boron whisker. They can also be used in combination. Among these fibrous reinforcing materials, reinforcement with glass fibers is particularly preferred, and there are no particular limitations on the glass fibers as long as they are generally used for reinforcing resins. For example, long fiber type (glass roving), short fiber type chopped strand,
It can be selected from milled fibers and the like. Glass fibers are also treated with a sizing agent (e.g. polyvinyl acetate, polyester sizing agent, etc.).

It may be treated with a coupling agent (for example, a silane compound, a borane compound, etc.) or other surface treatment agent. Furthermore, it may be coated with a resin such as a thermoplastic resin or a thermosetting resin. Usually, long fiber type glass fibers are used by being cut into a desired length before or after blending with a resin, and this mode of use is also useful in the present invention.

The glass fiber length is preferably such that the main portion in the composition has a length of 0.2 mm or more.

The blending amount of such fibrous reinforcing material is (A) nylon-4,
6 resin and (B) nylon-66 and/or nylon-
The amount is 5 to 50 parts by weight based on a total of 100 parts by weight of the 6,6 resin. If the blending amount is less than 5 parts by weight, the reinforcing effect is small, so the strength and heat resistance of the molded product are low, and the characteristics of the combination with the powdered reinforcing material cannot be exhibited. On the other hand, if the amount exceeds 50 parts by weight, the melt flowability of the composition will be significantly deteriorated, and therefore nylon-66 and/or nylon-6
, 6 resin cannot prevent the occurrence of defective molded appearance.

The powdered reinforcing material (D) used in the present invention includes kaolin, clay, and wollastonite.

Examples include tar, mica, calcium carbonate, and barium sulfate. Among these powdered reinforcing materials, silicate-based ones are preferred, and calcined kaolin, wollastonite, mica, and talc are particularly effective. In general, these powdered reinforcing materials may be surface-treated with a coupling agent mainly consisting of a silane compound such as aminosilane.

The blending amount of the powdered reinforcing material is (A) nylon-4,
6 resin and (B) nylon-68 and/or nylon-
5 to 100 for a total of 1 ioo heavy part of 6,6 resin
Parts by weight. If this amount is less than 5 parts by weight, the effect of improving dimensional stability will be small, the appearance of the molded product will be poor, and the characteristics of the combination with the fibrous reinforcing material cannot be exhibited. on the other hand,
If the amount exceeds 100 parts by weight, even if nylon-6 and/or nylon-6,6 resin is blended, the effect of improving impact strength will no longer be exhibited.

Pigments and other compounding agents may be added to the resin composition of the present invention in the desired amount. Examples of such compounding agents include heat stabilizers, colorants, antioxidants, lubricants, ultraviolet absorbers, antistatic agents, flame retardants, and the like.

Any blending method can be used to obtain the resin composition of the present invention.

Generally, it is preferable to disperse these ingredients as uniformly as possible, and homogenize all or part of them by mixing them simultaneously or separately using a mixer such as a blender, kneader roll, extruder, etc. A method is used in which some of the mixed components are mixed simultaneously or separately, for example, in a blender, kneader roll extruder, etc., and the remaining components are further mixed in these mixers or extruders to homogenize. be able to.

Furthermore, it is possible to use a method in which a pre-triblended composition is mixed with melt III in a heated extruder to homogenize it, extruded into a wire shape, and then cut into a desired length and granulated.

The molding composition thus prepared is normally kept in a sufficiently dry state, and then put into a molding machine hopper and subjected to molding.

Furthermore, it is also possible to tri-blend the raw materials constituting the composition, directly charge it into the hopper of a molding machine, and melt and knead it in the molding machine.

[Example] The present invention will be explained in detail with reference to Examples below.

In the examples, various properties were measured by the following methods.

(1) Static strength: Tensile test: Based on ASTHD-638.

Bending test: Based on AS D-790.

Impact test: Based on ASTM D-256 (with isot and notch).

(2) Heat distortion temperature: Measured according to ASTHD-648 at a load of 264 Psi and a specimen thickness of 1/4°.

(3) Molded Appearance A disk with a diameter of 2 inches and a thickness of 178 inches was molded, and the surface condition was visually evaluated according to the following evaluation criteria.

Specific negative base ○: Uniform and glossy Δ: Lack of gloss is observed near the gate ×: Surface is uneven and die-ending-like patterns are observed (4) Intrinsic viscosity m - Cresol solution at 35°C Examples 1 to 5 and Comparative Examples 1 to 4 Nylon-4,6 resin (5TANY) having an intrinsic viscosity of 1.20
L■ Manufactured by DSM in the Netherlands>, nylon-6 resin with an intrinsic viscosity of 1.34 (Tijin nylon NH3101, bacterial medium)
Nylon-6,6 resin with an intrinsic viscosity of 1.25 (Leona 13003, manufactured by Asahi Kakai), chopped strand-cut glass fiber with a length of 3 mm, and kaolin (Translink 445, manufactured by Engelhard, USA) were blended and mixed according to the composition shown in Table 1. The polyamide was dried at 110°C for 8 hours under a reduced pressure of 10 Torr prior to blending. The mixture was then extruded at 310'C using a twin-screw extruder to obtain pellets. Furthermore, using this pellet, a 5-ounce injection molding machine was used at a cylinder temperature of 290 to 310°C, an injection pressure of 10001000K, and a mold temperature of 120°C.

A test piece for measuring characteristics was molded under conditions of a cooling time of 20 seconds and a total cycle time of 40 seconds. Using this test piece, static strength and heat distortion temperature were measured, and the appearance of the test piece was observed. These results are shown in Table 1.

As is clear from Table 1, nylon-6 resin.

In Comparative Example 1, in which nylon-6,6 resin was not blended, the impact strength was low and the surface of the molded product lost its gloss. On the other hand, nylon-6m fat or nylon-6,6
In Examples 1 to 5 in which the resin was blended, the impact strength was improved and the surface appearance was improved. In addition, the tensile strength 2 bending strength is maintained, and although the heat distortion temperature decreases slightly,
Note that it shows a sufficiently high value of 260°C or higher. Furthermore, if the amount of nylon-6 resin is too large (Comparative Example 2) or the amount of glass fiber is too small (Comparative Example 3), the heat deformation temperature will drop too much and the resin will lose its value as a nylon-4,6 resin. On the other hand, when the amount of kaolin blended is small (Comparative Example 4), the appearance of the molded product is markedly poor.

Examples 6-8 Nylon-4,6 resin (5TANY) with an intrinsic viscosity of 1.20
L ■ Manufactured by DSM in the Netherlands>, nylon-6 resin with an intrinsic viscosity of 1.34 (Tijin nylon NH3101, in bacteria)
I) chopped strand cut glass fiber with a length of 3.0 mm and mica (Sugilite Mica 1503.
(manufactured by Furietsuta, USA), talc (Micron White 50)
00A, Hayashi Kasei (made by Kiki) or Wollastonite (
CHC-74N (manufactured by Hayashi Kasei 01) was blended and mixed according to the composition shown in Table 1. Note that polyamide is heated to 110℃ prior to compounding.
, and dried under reduced pressure of 10 Torr for 8 hours. The mixture was then extruded at 310°C using a twin-screw extruder to obtain pellets.

Test pieces were molded using the pellets under the same conditions as in Examples 1 to 5, static strength and heat distortion temperature were measured, and the appearance of the test pieces was observed. These results are shown in Table-1.

From the results in Table 1, mica was used instead of kaolin.

It can be seen that similar effects can be obtained by using talc or wollastonite.

[Effects of the Invention] As detailed above, the polyamide resin composition of the present invention has the following effects:
In order to improve the drawbacks of the composition consisting of nylon-4,6 resin, fibrous reinforcing material and powdered reinforcing material, it is further blended with nylon-6 resin and/or nylon-6,6 resin to improve impact strength. As a result, it becomes possible to mold an excellent molded product with a well-balanced mechanical strength, thermal properties, dimensional stability, and surface appearance, which is of great industrial merit.

Claims (1)

[Claims] 1. (A) Nylon-4,6 resin, (B) Nylon-6
and/or nylon-6,6 resin, (C) fibrous reinforcing material, and (D) powdered reinforcing material, with a weight percent ratio of component (A) to component (B) of 90 to 40:10 to 60. Yes, and per 100 parts by weight of the sum of components (A) and (B), (C
A polyamide resin composition characterized in that component () is contained in an amount of 5 to 50 parts by weight, and component (D) is contained in an amount of 5 to 100 parts by weight. 2. The polyamide resin composition according to claim 1, wherein the fibrous reinforcing material is glass fiber. 3. Powdered reinforcing material is calcined kaolin, wollastonite,
The polyamide resin composition according to claim 1, which is one or more selected from mica and talc.