JPH01168758A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain the title compsn. which is excellent in mechanical properties, such as heat resistance and rigidity, thermal deformation temp. and sliding characteristics (surface smoothness, friction coefficient, load resistance, etc.), by blending a polyamide with a potassium titanate fiber, and a glass fiber and/or a carbon fiber in respective predetermined proportions. CONSTITUTION:Units of a dicarboxylic acid component (a) composed of 65-100mol% terephthalic acid and 35-0mol% other arom. dicarboxylic acid (e.g., isophthalic acid) are polycondensed with units of a diamine component (b) composed of an aliph. diamine (e.g., 1,6-diaminohexane) and/or an alicyclic diamine [e.g., bis(aminomethyl)cyclohexane], thereby obtaining a polyamide (A). 100 pts.wt. component (A) is blended with 5-40 pts.wt. potassium titanate fiber(B) having a fiber diameter of 0.1-3mum and a fiber length of 5-100mum, and 20-100 pts.wt. glass fiber having a fiber diameter of 1-20mum and a fiber length of 1-10mm and/or carbon fiber having a fiber diameter of 5-20mum and a fiber length of 0.2-20mm (C).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polyamide resin composition that has excellent mechanical properties such as strength, cold resistance, and sliding properties.

(Prior art and its problems) Polyamides such as nylon 6 and nylon 66 have excellent mechanical strength, rigidity, heat resistance, oil resistance, etc. Taking advantage of these properties, they are used as engineering plastics for some mechanical parts, Applications are being made to electrical appliance parts, automobile parts, etc.

Also known is a resin composition with improved heat resistance and rigidity, which is made by blending carbon fibers, glass fibers, and fibrous potassium titanate with the above-mentioned polyamide (JP-A No. 60-206861).

However, this conventionally known polyamide resin composition is
Although it has relatively good heat resistance as a part for optical products and home appliances, it is still unsatisfactory in terms of heat resistance and sliding properties when used as a sliding material for bearings, gears, etc. .

Therefore, an object of the present invention is to provide a polyamide resin composition having characteristics that are satisfactory for use as a sliding material.

(Structure of the invention) The polyamide resin composition of the present invention.

(8) Polycondensation of a dicarboxylic acid component unit (a) consisting of a terephthalic acid component and/or an aromatic dicarboxylic acid component other than terephthalic acid and a diamine component (b) consisting of an aliphatic diamine and/or an alicyclic diamine. (B) 5 to 40 parts by weight of potassium titanate fibers per 100 parts by weight of the polyamide, and (C) the polyamide 1
00 parts by weight of at least one type of fiber selected from the group consisting of glass fibers and carbon fibers.

(Function) That is, the polyamide resin composition of the present invention contains aromatic polyamide (component (a)), potassium titanate fiber (component (b)
) and glass fiber or carbon fiber (component (C)).

The aromatic polyamide of component (a) has a high melting point (-300 to 340°C for boat fishing) and a high glass transition point (-100 to 150°C for boat fishing), and is suitable for resin compositions. It imparts excellent heat resistance to mechanical properties such as tensile strength and bending strength, as well as abrasion resistance, surface smoothness,
It also has excellent sliding properties such as friction coefficient.

The fibers of component (b) and component (C) further improve the mechanical properties and sliding properties of the polyamide, and in particular, significantly improve properties such as seizure load.

Thus, according to the present invention, a polyamide resin composition that is particularly useful for use as a sliding material can be obtained.

(Preferred Embodiment of the Invention) (A) Polyamide The polyamide in the polyamide resin composition of the present invention comprises (a) a dicarboxylic acid component consisting of a terephthalic acid component and/or an aromatic dicarboxylic acid component other than terephthalic acid; , (b) a diamine component unit consisting of an aliphatic diamine and/or an alicyclic diamine.

The composition of the dicarboxylic acid component unit (a) may be a single terephthalic acid component unit, or may be a mixture of a terephthalic acid component unit and an aromatic dicarboxylic acid component unit other than the terephthalic acid component unit. Furthermore, an aromatic dicarboxylic acid component unit other than terephthalic acid may be used alone. Specific examples of the aromatic dicarboxylic acid component units other than the terephthalic acid component units include isophthalic acid, phthalic acid, 2-methylterephthalic acid, naphthalene dicarboxylic acid, and the like. Among these, isophthalic acid component units or naphthalene dicarboxylic acid component units, particularly isophthalic acid component units, are preferably used.

In the present invention, especially when using an aromatic dicarboxylic acid containing terephthalic acid as a main component, terephthalic acid accounts for 60 to 100 mol% of the dicarboxylic acid component units (a), and the aromatic dicarboxylic acid other than the terephthalic acid component units is The content of the group dicarboxylic acid is preferably in the range of 0 to 40 mol%.

Of the dicarboxylic acid component units (a), terephthalic acid is 6
When the content of aromatic dicarboxylic acid component units other than terephthalic acid component units is less than 0 mol% and more than 40 mol%, molded products obtained from the composition containing such polyamide have poor heat aging resistance and heat deformation resistance. There are disadvantages in terms of heat resistance properties including temperature, mechanical properties such as tensile strength, bending strength, and abrasion resistance, and chemical and physical properties such as chemical resistance and water resistance.

However, depending on the application, the required properties may be moderate, in which case the amount of terephthalic acid may be less than 60 mol%, and in extreme cases, the amount of terephthalic acid may be less than 60 mol%. You can.

However, in the present invention, the dicarboxylic acid component unit (
a) together with terephthalic acid component units and/or aromatic dicarboxylic acid component units other than terephthalic acid component units,
There is no problem in including a small amount, for example, about 10 mol %, of polyhydric carboxylic acid component units such as adipic acid, sebacic acid, trimellitic acid, and pyromellitic acid.

In the polyamide composition according to the invention, the aliphatic diamine component units are linear, branched alkylene diamine component units having 4 to 25 carbon atoms, in particular 6 to 18 carbon atoms. As a specific example of such an alkylene diamine component unit, for example, 1
．． 4-diamino-1,1-dimethylbutane, 1,4-diamino-1,1-ethylbutane, 1,4-diamino-1
,2-dimethylbutane, 1,4-diamino-1,3-dimethylbutane, 1,4-diamino-1,4-dimethylbutane, 1,4-diamino-2,3-dimethylbutane, 1.2- Diamino-1-butylethane, 1,6-diamitsuhexane, 1,7-diaminohbutane, 1,8-diaminooctane, 1,6-diamitsu-2,5-dimethylhexane, 1,6-diamitsu-2,4- Dimethylhexane, 1,6-diami2-3,3-dimethylhexane, l
, 6-diami2, 2-dimethylhexane, 1.9-
Diaminononane, 1,6-Diami2,2,2,4- Trimethylhexane, 1,6-Diami2,4,4-
)-dimethylhexane, 1,7-diami2, 2,3-dimethylhebutane, 1,7-diami2, 2,4-dimethylhebutane, 1,7-diami2, 2,5-dimethylhebutane, 1,7-diami2 .2-dimethylheptane, 1
．． 10-diaminodecane, 1,8-diamino-1,3-
Dimethyloctane, 1.8-diamino-1,4-dimethyloctane, 1.8-diamino-2,4-dimethyloctane, 1.8-diamino-3,4-dimethyloctane,
1.8-diamino-4,5-dimethyloctane, 1.8
-Diamino-2,2-dimethyloctane, 1,8-diamino-3,3-dimethyloctane, 1,8-diamino-
4,4-dimethyloctane, 1,6-diamitwo 2.4
Examples include component units such as -diethylhexane, 1,9-diamino-5-methylnonane, 1,11-diaminoundecane, and 1,12-diaminododecane. Such aliphatic diamines are actively utilized mainly when the dicarboxylic acid component unit (a) has terephthalic acid as a main component.

Among these, in particular, 1,6-cyamitsuhexane,
Component units such as 1.8-diaminooctane, 1.10-diaminodecane, and 1.12-diaminododecane, or mixed component units thereof are preferably used.

The alicyclic diamine component unit has 6 to 25 carbon atoms,
and a diamine containing at least one alicyclic hydrocarbon ring, specifically 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1.4 -Bis(aminomethyl)cyclohexane, isophoronediamine, piperazine, 2,5-dimethylpiperazine, bis(4-aminocyclohexyl)methane, bis(4-aminocyclohexyl)propane, 4.4°-diamino-3,3°- dimethyldicyclohexylmethane, 4.4°-diamino-3,
3°-dimethyl-5,5'-dimethyldicyclohexylmethane, 4,4°-diamino-3,3°-dimethyl-5
, 5゛-dimethyldicyclohexylpropane, α, α°
-bis(4-aminocyclohexyl)-p-diisopropylbenzene, α,α゛-bis(4-aminocyclohexyl) -m-diisopropylbenzene, α,α°-bis(4-aminocyclohexyl)=1,4-cyclohexane , α, α゛-bis(4-aminocyclohexyl)-
Examples include 1,4-cyclohexane.

Such alicyclic diamine has a dicarboxylic acid component unit (
It is actively used when a) mainly consists of an aromatic dicarboxylic acid other than terephthalic acid.

Among these alicyclic diamine components, bis(aminomethyl)cyclohexane, bis(4-aminocyclohexyl)methane, and 4,4°-diamino-3,3°-dimethyldicyclohexylmethane are preferred, particularly bis(4-diamino-3,3°-dimethyldicyclohexylmethane).
Preferred are aminocyclohexyl)methane, 1,3-bis(aminocyclohexyl)methane, and 1,3-bis(4-aminomethyl)cyclohexane.

In the polyamide composition according to the present invention, the composition of the dicarboxylic acid component unit (a) described above is preferably selected depending on the number of carbon atoms of the diamine. In this way, when selecting the composition of the dicarboxylic acid component unit (a) according to the number of carbon atoms in the diamine, it is particularly important to ensure that the resulting polyamide composition has excellent moldability and has good heat aging resistance, heat distortion temperature, etc. This is because it provides a molded product with excellent heat resistance properties and mechanical properties such as bending strength and abrasion resistance.

That is, in the case where terephthalic acid is used as the main component as the dicarboxylic acid component (a) and an aliphatic alkylene diamine is used as the diamine component (b), when the number of carbon atoms in the aliphatic alkylene diamine is, for example, 6, The composition of the dicarboxylic acid component unit (a) is preferably such that the terephthalic acid component unit is in the range of 60 to 85 mol%, and the aromatic dicarboxylic acid component unit other than the terephthalic acid component unit is in the range of 15 to 40 mol%. When the number of carbon atoms in the aliphatic alkylene diamine is, for example, 8, the composition of the dicarboxylic acid component unit (a) is preferably such that the terephthalic acid component unit is in the range of 65 to 100 mol%, and the aromatic acid component unit other than the terephthalic acid component unit is Dicarboxylic acid component unit is 0 to 3
It is in the range of 5 mol%. Further, when the aliphatic alkylene diamine component unit has, for example, 10 to 18 carbon atoms,
The composition of the dicarboxylic acid component unit (a) is preferably 75 to 100 mol% of terephthalic acid component units and 0 to 25 mol% of aromatic dicarboxylic acid component units other than terephthalic acid component units.

Furthermore, in the polyamide composition according to the present invention, the polyamide (A) described above is soluble in concentrated sulfuric acid at a temperature of 50°C, and has an intrinsic viscosity [η] measured in concentrated sulfuric acid at a temperature of 30°C. It is preferable that it is 0.5 dIL/g or more. Preferably, [η] is 0.6 d1g or more, particularly preferably in the range of 0.7 to 3.0 dIL/H.

Such a concentrated sulfuric acid-soluble polyamide can be obtained by a conventionally known method. For example, P
olymer Review, Dan, Condensa
tionPolymers by Interface
al and 5solution Methods
'(p. W. Morgan, Interscience
e Publishers (1965)) and Mak
romol, Chem, 47.93-113 (19
61), it can be obtained by polycondensing the diacid halide of an aromatic dicarboxylic acid, which is a constituent unit of the polyamide described above, and a diamine using a solution method. It can also be obtained by interfacial polymerization. Alternatively, it can also be obtained by polycondensing the aromatic dicarboxylic acid and diamine or its nylon salt by a melt method in the presence or absence of a solvent such as water. Furthermore, it can also be obtained by polycondensing the polyamide oligomer obtained by the former method by a homopolymerization method.

Furthermore, in the polyamide composition according to the present invention, the polyamide (A) includes not only the above-mentioned concentrated sulfuric acid-soluble polyamide, but also a polyamide having a composition within the same range as this concentrated sulfuric acid-soluble polyamide, but which is insoluble in concentrated sulfuric acid at 50°C. May contain. Here, polyamide that is insoluble in concentrated sulfuric acid at 50°C refers to pulverized polyamide, and a concentrated sulfuric acid solution with a concentration of 1% by weight of the polyamide that has passed through 32 meshes.
It refers to a polyamide obtained by heating and stirring for a period of time and then filtering it through a 2G glass filter at a temperature of 50°C to remove the soluble portion.

Such concentrated sulfuric acid-soluble polyamides are not particularly limited, but typically have a melt viscosity (MFR) of 20g710min or less at 360°C and a load of 2.16kg,
Preferably 5 g/10 minutes or less, particularly preferably 0.
1g 710 minutes or less.

Such a concentrated sulfuric acid-soluble polyamide can be produced as a by-product during the production of the above-mentioned concentrated sulfuric acid-soluble polyamide. Furthermore, by selecting the reaction conditions, the amount produced can be intentionally increased. Therefore, in such a case, a mixture of a polyamide soluble in concentrated sulfuric acid and a polyamide insoluble in concentrated sulfuric acid can be obtained. Furthermore, if necessary, the polyamide soluble in concentrated sulfuric acid or the mixture thereof with the polyamide insoluble in concentrated sulfuric acid can be further crosslinked to have a high molecular weight, thereby making it entirely insoluble in concentrated sulfuric acid.

Therefore, although not limited in any way, as a method for producing concentrated sulfuric acid-insoluble polyamide or a mixture of concentrated sulfuric acid-soluble polyamide and concentrated sulfuric acid-insoluble polyamide, for example,
A method of further solid-phase polymerizing the concentrated sulfuric acid-soluble polyamide,
When producing concentrated sulfuric acid-soluble polyamide by melt polycondensation, the polycondensation temperature is set to a higher temperature, e.g.
℃ or above, a method of polycondensing diamine and aromatic dicarboxylic acid with a charging molar ratio of 1.03 or more, and a method of using trifunctional or higher functional polyamine or polycarboxylic acid together with diamine and aromatic dicarboxylic acid. A method of polycondensing this can be exemplified.

(B) Potassium titanate fibers In the present invention, potassium titanate fibers are blended in an amount of 5 to 40 parts by weight, particularly 10 to 30 parts by weight, per 100 parts by weight of the polyamide to improve surface smoothness, coefficient of friction, and resistance. Improves sliding characteristics such as load resistance.
.

In other words, if only the glass fibers and carbon fibers described below are mixed,
Even if a resin composition that is satisfactory in terms of mechanical properties such as tensile strength and heat resistance is obtained, the sliding properties mentioned above tend to deteriorate, but by incorporating potassium titanate fibers, the mechanical properties can be improved. It becomes possible to provide satisfactory sliding characteristics while maintaining heat resistance and heat resistance.

If the amount of potassium titanate fiber blended is less than the above range, satisfactory sliding properties will not be obtained, and if it is too much, properties such as heat resistance and tensile strength will be unsatisfactory, and the resin composition The moldability of objects also decreases.

Such potassium titanate fiber has a general formula of 20.(Ti
It is a fibrous crystal represented by Oz)n, and the fiber diameter is usually 0.1 to 3 μm, especially 0.2 to 2 μm, and the fiber length is 5 to 100 μm, especially 10 to 50 μm. be done.

(C) Glass fiber 1. In the present invention, glass fibers and/or carbon fibers are further blended to improve the mechanical properties such as tensile strength, heat resistance, and load carrying capacity of the resin composition. These glass fibers to carbon fibers have a total amount of at least 20 to 1.0 parts per 100 parts by weight of the polyamide resin. They are used alone or in combination in a proportion of 00 parts by weight, especially from 30 to 80 parts by weight.

If the blending amount is less than the above range, the desired property improvement effect cannot be obtained, and if it is used in a larger amount than the above range, the sliding properties such as surface smoothness may become unsatisfactory. The moldability of the resin composition also decreases.

Further, in the present invention, it is preferable to use glass fibers and carbon fibers in combination, and it is especially desirable to use glass fibers and carbon fibers together in a ratio of 9:1 to 1:9 on a weight basis. .

By using glass fibers and carbon fibers in combination in this way, the remarkable effect of dramatically improving load bearing capacity is achieved.

For example, as is clear from the examples described below, in the sample (comparative example 4) in which only potassium titanate fiber was blended with the polyamide component (A), the limit pv value measured with the Matsubara ring abrasion tester was 400 kg/cm2. , and a sample containing potassium titanate fibers and glass fibers (Example 1), it was 500 kg/cm'', whereas in addition to potassium titanate fibers, glass fibers and carbon fibers (weight ratio 2:
In the sample (Example 3) containing 1), 700 kg/
It will be understood that cm' and the critical pv value are dramatically improved.

The glass fiber used in the present invention is generally used as a reinforcing agent for thermoplastic resins, and has a fiber diameter of 1 to 20 μm, particularly 6 to 13 μm, and a fiber length of 1 to 10 mm, particularly Those in the range of 3 to 6 mm are preferably used.

Also preferably used are glass fibers whose surfaces have been treated with a silane compound such as vinyltriethoxysilane, 2-aminopropyltriethoxysilane, 2-glycidoxypropyltrimethoxysilane, or the like.

The carbon fibers used in the present invention include various carbon fibers such as flame-resistant, carbonaceous, graphite, and carbon fibers obtained by firing cellulose fibers, polyacrylonitrile fibers, lignin fibers, petroleum-based special pitches, etc. as raw materials. Generally, those having a fiber diameter of 5 to 20 μm and a fiber length of 0.2 to 20 mm are preferably used.

Other compounding agents The polyamide composition of the present invention may contain, in addition to the above-mentioned components, a heat stabilizer, a weather stabilizer, a plasticizer, a thickener, an antistatic agent, a mold release agent, to the extent that the object of the present invention is not impaired. , pigments, dyes,
Various known compounding agents may be added, such as inorganic or organic fillers, nucleating agents, and inorganic compounds such as Teflon, molybdenum disulfide, boron nitride, carbon black, talc, clay, and mica.

Furthermore, various other polymers such as polyolefins such as polyethylene, polypropylene, poly4-methyl-1-pentene, ethylene-propylene copolymers, ethylene-1
- Olefin copolymers such as butene copolymers, propylene/ethylene copolymers, propylene/1-butene copolymers, polyolefin elastomers, or modified polymers thereof, polystyrene, polyamides, polycarbonates,
Polyacetal, polysulfone, polyphenylene oxide, fluororesin, silicone resin, etc. may be blended.

The polyamide resin composition of the present invention has the above-mentioned (A) to (C
) and various compounding agents added as necessary,
Means known per se, for example a Henschel mixer, -
It is prepared by mixing using a blender, ribbon blender, tumbler blender, etc., or by melt-kneading in a screw extruder, multi-screw extruder, kneader, Banbury mixer, etc. after mixing, and then granulating or pulverizing. Ru.

(Effects of the Invention) The thus obtained polyamide resin composition of the present invention has excellent mechanical properties such as heat resistance and rigidity, heat deformation temperature, and sliding properties such as surface smoothness, friction coefficient, and load resistance. Ori 1.
It is advantageously used as molded products such as bearings, gears, cams, thrust washers, piston rings, etc.

(Example) As a five-layer ±upolyamide, dicarboxylic acid component: 70 mol% of terephthalic acid, 30 mol% of isophthalic acid, diamine component: l,6-diamithexane intrinsic viscosity,
Use 1.0 dfL/g (concentrated sulfuric acid, 30°C).

Using this polyamide, mix them according to the following formulation: Polyamide 100 parts by weight Potassium titanate fiber 33 (diameter 1 μm, length 20-50 μm) Glass fiber 33 (diameter 13 μm, length 3 mm) Using an extruder with a shaft vent, the mixture was melt-kneaded and pelletized at 330°C.

The resulting pellets were then molded using a 2 ounce screw line injection molding machine set at 330°C at a mold temperature of 120°C to create sample pieces for each measurement. Using these test pieces, their surface smoothness was observed and the following properties were measured. The measurement results are shown in Table 1.

Tensile strength: Based on ASTM D-638.

Heat distortion temperature: Based on ASTM D-648.

Established.

Practical Direction 1 Pellets of a resin composition were produced in exactly the same manner as in Example 1, except that carbon fibers (diameter 7 μm, length 3 mm) were used instead of glass fibers, and the same evaluation was carried out. I did it.

The measurement results are also shown in Table 1.

A resin composition was evaluated in exactly the same manner as in Example 1 except that the following formulation was used: polyamide 100 parts by weight potassium titanate fiber 16 glass fiber 32 carbon fiber 16.

The measurement results are also shown in Table 1.

Comparative Examples 1 to 4 Using each material used in Example 1, polyamide alone (Comparative Example 1), polyamide glass fiber (Comparative Example 2), polyamide and carbon fiber (Comparative Example 3), and polyamide and potassium titanate fiber (Comparative Example 4) was evaluated in the same manner as in Example 1.

The measurement results are also shown in Table 1.

Claims (1)

[Claims] (1) (A) A dicarboxylic acid component unit (a) consisting of a terephthalic acid component and/or an aromatic dicarboxylic acid component other than terephthalic acid, and a diamine component unit (b) consisting of an aliphatic diamine and/or an alicyclic diamine. (B) 5 to 40 parts by weight of potassium titanate fibers per 100 parts by weight of the polyamide, and (C) 20 to 100 parts by weight per 100 parts by weight of the polyamide.
A polyamide resin composition comprising: parts by weight of at least one type of fiber selected from the group consisting of glass fiber and carbon fiber.