JPH0873737A - Polyamide resin composition - Google Patents

Abstract

PURPOSE: To obtain a polyamide resin composition improved in impact resistance and toughness without any reduction in rigidity by mixing a polyamide resin with a specified amide compound. CONSTITUTION: This composition is obtained by mixing 100 pts.wt. polyamide resin with 0.001-10 pts.wt. amide compound represented by formula I. In the formula, R<1> and R<2> may be the same or different and are each 3-12C cycloalkyl, a group of formula II (R<3> is 1-18C alkyl or 2-18C alkenyl) or a group of formula III (R<4> is 1-4C linear or branched alkylene; and R<5> is the same as R<3> ). The incorporation of at least either an inorganic nucleating agent or a metal salt of a fatty acid into the composition in addition is desirable since the crystallizability is further improved, because the shortening of molding cycle and an improvement in physical properties, such as rigidity, can be realized thereby.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide resin composition having significantly improved impact resistance and toughness without lowering rigidity.

[0002]

2. Description of the Related Art Polyamide resins are excellent in heat resistance, mechanical properties, chemical resistance, wear resistance, etc.
It is widely used as a material for electrical equipment parts and various industrial products.

However, with the recent advancement of industry, the demand for polyamide resins has become more severe and diversified. Above all, there is a growing need for shorter molding cycles and improved mechanical properties.

The present inventors have previously proposed that by blending an amide compound having a specific structure, the molding cycle can be shortened without impairing various characteristics (Japanese Patent Application No. 6-15830).

On the other hand, among mechanical properties, there is a strong demand for improvement in toughness. For example, in the case of molded products, the reduction of toughness due to imparting high cycle property is a serious problem, and in the case of films and filaments, toughness is insufficient. There is a problem of stretchability, and improvement thereof has been awaited.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, it is an object of the present invention to provide a polyamide resin composition having improved impact resistance and toughness without lowering rigidity. To do.

[0007]

As a result of further studies on the effect of the above-mentioned polyamide resin composition proposed by the present inventors, the present inventors have found that Among them, it was newly found that not only the shortening of the molding cycle but also the impact resistance and toughness can be greatly improved by adding a predetermined amount of the compound having a specific structure, and the present invention was completed based on such findings. Came to do.

That is, the polyamide resin composition excellent in impact resistance and toughness according to the present invention is a polyamide resin 10
It is characterized by containing 0.001 to 10 parts by weight of the amide compound represented by the general formula (1) per 0 part by weight.

[0009] [In the formula, R ¹ and R ² are the same or different and have 3 to 12 carbon atoms.
And a group represented by the general formula 2 or the general formula 3. ]

[0010] [In the formula, R ³ represents an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms. ]

[0011] [In the formula, R ⁴ represents a linear or branched alkylene group having 1 to ⁴ carbon atoms. R ⁵ has the same meaning as R ³ in formula (2). ]

The polycarboxylic acid amide compound represented by the general formula (1) can be easily prepared by amidating 2,6-naphthalenedicarboxylic acid and a predetermined alicyclic monoamine according to a conventionally known method. You can

The alicyclic monoamine according to the present invention includes
In addition to cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine, cyclobutylamine, cyclooctylamine, cyclododecylamine and the like, compounds represented by the general formula (4) or the general formula (5) can be mentioned, among which cyclohexyl Amines are especially recommended.

[0014] [In the formula, R ⁶ represents an alkyl group having 1 to 18 carbon atoms or an alkenyl having 2 to 18 carbon atoms. ]

Examples of the alicyclic monoamine represented by the general formula (4) include methylcyclohexylamine, ethylcyclohexylamine, propylcyclohexylamine, isopropylcyclohexylamine, tert-butylcyclohexylamine, n-butylcyclohexylamine and isobutylcyclohexylamine. , Sec-butylcyclohexylamine, n-amylcyclohexylamine, isoamylcyclohexylamine, sec-amylcyclohexylamine, tert-amylcyclohexylamine, hexylcyclohexylamine, heptylcyclohexylamine, octylcyclohexylamine, nonylcyclohexylamine, decylcyclohexylamine, un Examples include decylcyclohexylamine and dodecylcyclohexylamine.

[0016] [In the formula, R ⁷ represents a linear or branched alkylene group having 1 to 4 carbon atoms. R ⁸ has the same meaning as R ⁶ in formula (4). ]

The alicyclic monoamine represented by the general formula (5) includes cyclohexylmethylamine, methylcyclohexylmethylamine, α-cyclohexylethylamine, β-cyclohexylethylamine, α-cyclohexylpropylamine, β-cyclohexylpropylamine, Examples include γ-cyclohexylpropylamine and methylcyclohexylpropylamine.

Among the amide compounds represented by the general formula (1), 2,6-naphthalenedicarboxylic acid dicyclohexylamide is most recommended.

The polyamide resin used in the present invention is a polyamide resin such as a polycondensate of diamine and dicarboxylic acid, a polycondensate of ω-aminocarboxylic acid, a lactam polycondensate, or a copolymerized polyamide resin thereof. And blends and the like, specifically, adipic acid, aminoundecanoic acid, aminocaproic acid, aminododecanoic acid, isophthalic acid, ε-caprolactam, 3,3′-dimethyl-
Polyamide starting from one or more of 4,4′-diaminodicyclohexylmethane, sebacic acid, terephthalic acid, α, ω-dodecanoic acid, hexamethylenediamine, xylylenediamine, and ω-laurolactam, and the polyamide Mixture, adipic acid and 1,3-benzenedimethanamine starting polymer, adipic acid and 1,3
3-benzenedimethanamine and bis (aminopropyl)
Examples of the polymer include poly (ethylene oxide) as a starting material, and more specifically, nylon 6, 66, 6
Homopolymers of 10, 11, and 12, etc., 6/66,
6/12, 6 / 6T, 66/610, 66/6
12, copolymers of 66 / 6T and the like, and mutual blends thereof and the like. Furthermore, blends with other polymers (for example, polyester) mainly containing these polyamides are also included. Among them, nylon 6 and its copolymer or blend show the effect of the present invention most remarkably.

The blending amount of the amide compound according to the present invention is
0.001-10 with respect to 100 parts by weight of polyamide resin
By weight, more preferably 0.01 to 5 parts by weight.
When the amount is less than 0.001 part by weight, it is difficult to obtain a predetermined modifying effect, and when the amount is more than 10 parts by weight, the modifying effect commensurate with the compounding amount cannot be expected, which is not practical. It is uneconomical and is not preferable in either case.

1 selected from the group consisting of a specific inorganic crystal nucleating agent and a fatty acid metal salt for the above amide resin composition.
By using one kind or two or more kinds of compounds (hereinafter collectively referred to as "combined component") in combination, the crystallinity can be further improved, the molding cycle can be shortened, and the physical properties such as rigidity can be improved.

Examples of the inorganic crystal nucleating agent include graphite, molybdenum disulfide, barium sulfate, calcium carbonate, sodium phosphate, talc, mica, kaolin and the like, and particularly magnesium silicate and aluminum silicate such as talc, mica and kaolin. Is recommended.

Specifically, the fatty acid metal salt has 1 carbon atom.
A compound obtained from a fatty acid of 0 to 25 and a metal of Group I to III of the periodic table is recommended, and examples of the fatty acid include myristic acid, palmitic acid, stearic acid, oleic acid, and behenic acid. Examples thereof include zinc, calcium, lithium, aluminum, barium and the like.

The blending amount of the combination component is not particularly limited as long as the predetermined effect is exhibited, but the recommended blending amount is 0.005 with respect to 100 parts by weight of the polyamide resin.
To 5 parts by weight, particularly 0.01 to 2 parts by weight.
If the amount is less than 0.005 parts by weight, the desired effect is not sufficiently exhibited, and if the amount exceeds 5 parts by weight, the toughness is greatly reduced, and the screwing is badly wound on the molding cycle, contrary to the object of the present invention. And the like occur, which is not preferable.

The resin composition according to the present invention may optionally contain other components such as stabilizers, surfactants, lubricants, pigments,
Dyes, heat-resistant agents, antioxidants, weathering agents, antistatic agents, fillers, reinforcing agents, flame retardants, plasticizers, other polymers, other nucleating agents, etc. are added within a range that does not impair the effects of the present invention. be able to.

As the stabilizer, phosphorus compounds such as tris (mixed, mono- and dinonylphenyl) phosphite and tris (2,4-di-tert-butylphenyl) phosphite; butylated hydroxytoluene, N,
N'-hexamethylenebis (3,5-di-tert-butyl-4-hydroxyhydrocinnamide), 1,3,5-trimethyl-2,4,6-tris- (3,5-di-tert-
Butyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3- (3 ', 5'-di-tert-butyl-
4'-hydroxyphenyl) propionate] phenolic compounds such as methane; 2- (2'-hydroxy-3 '
UV absorbers such as -tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole; carbon black; trade name "Naugard 445" (calcium shiraishi) and the like.

As the surfactant, glycerin fatty acid ester, polyoxyethylene sorbitan fatty acid (for example, C12-18) ester, polyethylene glycol fatty acid (for example, C8-22) ester, polyoxyethylene (for example, addition) Number of moles = 4 to 50) Alkyl (for example, having 7 or more carbon atoms) phenyl ether, polyoxypropylene polyoxyethylene block polymer, nonionic surfactant such as polyethylene glycol; fatty acid (for example, 8 to 22 carbon atoms) Salt (eg,
Anionic surfactants such as sodium, potassium and ammonium) are exemplified.

As the lubricant, liquid hydrocarbons, aliphatic hydrocarbons such as hydrogenated polybutene, and higher fatty acids (for example,
8 to 22 carbon atoms; higher fatty acid (for example, 8 to 2 carbon atoms)
2) metal salts (for example, aluminum, calcium, magnesium, zinc); aliphatic monohydric alcohols (for example,
Carbon number 4-18); montanic acid and ethanediol, 1,
Esters of 3-butanediol, fatty acid esters of monohydric (or polyhydric) alcohols such as bran wax; hydrogenated castor oil,
Triglycerides such as acetylated monoglyceride and waxes, ethylene bis fatty acids (for example, having 12 to 2 carbon atoms)
2) amides, higher fatty acid amides such as higher fatty acid (for example, C8-22) amides; dimethylpolysiloxane,
Examples include silicone oils such as methylphenylpolysiloxane; montanic acid (eg, sodium, calcium) and the like.

The method of blending the nucleating agent used in the present invention is not particularly limited, and it is a method of adding at the time of polymerization, a method of melt-kneading with an extruder, a method of adding at the time of injection molding, a method of dry blending, and a combination of these methods. Different methods are available. Usually, melt kneading with an extruder is preferred.

The polyamide resin composition of the present invention can be applied to usual molding methods such as extrusion molding, injection molding, blow molding and vacuum molding, and molded articles such as automobile parts and electric / electronic parts, non-stretched parts. Alternatively, it can be used as a stretched film, sheet, filament or the like.

In the case of an injection-molded product, it is very useful as a high cycle grade having excellent impact resistance and toughness.

In the case of a stretched film or filament,
It is possible to improve the draw ratio, which has been considered impossible due to stretch unevenness (breakage, etc.), and this can greatly contribute to the improvement of productivity.

[0033]

EXAMPLES The present invention will be described in detail below with reference to Examples and Comparative Examples. However, the present invention is not limited to the following examples unless it exceeds the gist. Each evaluation was carried out according to the method described below.

(1) Elastic Modulus The flexural elastic modulus was measured according to JIS K-7203.

(2) Impact strength Charpy impact strength of a notched test piece was measured according to JIS K-7111.

(3) Elongation The elongation at break was measured according to JIS K-7113. A dumbbell No. 2 type test piece was used as the test piece.

Example 1 Nylon 6 dried under reduced pressure at 110 ° C. for 7 hours (relative viscosity η
r = 2.6) 100 parts by weight of 2,6-naphthalenedicarboxylic acid dicyclohexylamide 0.1 part by weight,
After mixing with a Henschel mixer, set to 240 ° C 20
It was melt-mixed and pelletized with a uniaxial extruder of mmφ.

The nylon composition obtained was dried under reduced pressure at 110 ° C. for 7 hours, and then injection-molded for 12 hours using an injection molding machine (manufactured by Nissei Plastic Industry Co., Ltd.) having a mold clamping pressure of 40 tons set at 240 ° C.
Seconds, a cooling time of 15 seconds, and a mold temperature of 80 ° C. to prepare a test piece, and the elastic modulus, impact strength and elongation were measured using the test piece. The results obtained are shown in Table 1.

Example 2 The elastic modulus, impact strength and elongation were measured in the same manner as in Example 1 except that the compounding amount of 2,6-naphthalenedicarboxylic acid dicyclohexylamide was changed to 0.2 part by weight. The results obtained are shown in Table 1.

Example 3 The elastic modulus, impact strength and elongation were measured in the same manner as in Example 1 except that the amount of 2,6-naphthalenedicarboxylic acid dicyclohexylamide was 0.3 part by weight. The results obtained are shown in Table 1.

Example 4 The elastic modulus, impact strength and elongation were measured in the same manner as in Example 1 except that 0.05 part by weight of talc (average particle size 1.6 to 2.0 μm) was added. The results obtained are shown in Table 1.

Example 5 The elastic modulus, impact strength and elongation were measured in the same manner as in Example 1 except that 0.3 part by weight of barium stearate was added. The results obtained are shown in Table 1.

Comparative Example 1 The elastic modulus, impact strength and elongation were measured in the same manner as in Example 1 except that 2,6-naphthalenedicarboxylic acid dicyclohexylamide was not added. The results obtained are shown in Table 1.

Comparative Example 2 The elastic modulus, impact strength and elongation were measured in the same manner as in Example 4 except that 2,6-naphthalenedicarboxylic acid dicyclohexylamide was not added. The results obtained are shown in Table 1.

Comparative Example 3 The elastic modulus, impact strength and elongation were measured in the same manner as in Example 5 except that 2,6-naphthalenedicarboxylic acid dicyclohexylamide was not added. The results obtained are shown in Table 1.

[0046]

By incorporating the amide compound according to the present invention, a polyamide resin composition having significantly improved impact resistance and toughness can be obtained without lowering the rigidity.

Claims (5)

[Claims] 1. To 100 parts by weight of polyamide resin,
Amide compounds represented by the general formula (1) 0.001-1
A polyamide resin composition excellent in impact resistance and toughness, characterized by containing 0 part by weight. [In the formula, R ¹ and R ² are the same or different and have 3 to 12 carbon atoms.
And a group represented by the general formula 2 or the general formula 3. ] [In the formula, R ³ represents an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms. ] [In the formula, R ⁴ represents a linear or branched alkylene group having 1 to ⁴ carbon atoms. R ⁵ has the same meaning as R ³ in formula (2). ] 2. The polyamide resin composition according to claim 1, which further contains one or more compounds selected from the group consisting of an inorganic crystal nucleating agent and a fatty acid metal salt. 3. The polyamide resin composition according to claim 2, wherein the inorganic crystal nucleating agent is magnesium silicate or aluminum silicate. 4. The polyamide resin composition according to claim 2, wherein the inorganic crystal nucleating agent is talc, mica or kaolin. 5. The polyamide according to claim 2, wherein the fatty acid metal salt is a compound obtained from a fatty acid having 10 to 25 carbon atoms and a metal of Group I to III of the periodic table. -Based resin composition.