JP3474248B2 - Molding materials for automotive parts - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel polyamide-based molding material for automobile parts. Specifically, automobiles made of polyamide that have excellent heat resistance as well as excellent mechanical strength, toughness, impact resistance, low water absorption, chemical resistance, boiling water resistance, calcium chloride resistance, and light weight. A molding material for parts.

[0002]

2. Description of the Related Art Aliphatic polyamides represented by nylon 6 and nylon 66 have excellent performances such as heat resistance, chemical resistance, rigidity, abrasion resistance, and moldability. It is widely used for automobile parts such as, and has contributed to the weight reduction of automobiles. However, although the conventional aliphatic polyamide has excellent performance as described above, it has a large water absorption rate, and the performance such as water resistance, boiling water resistance, salt water resistance, and alcohol resistance is not sufficient, and thus limited to limited parts. I was just hiring. Furthermore, due to the higher performance of automobile engines and the higher density of parts in the engine room in recent years, the temperature inside the engine room has risen, and conventional resins are no longer able to handle heat resistance. There is.

In response to such demands in the world, various semi-aromatic polyamides containing terephthalic acid and 1,6-hexanediamine as main components have been proposed and some of them have been put into practical use. JP-A-3-7761, JP-A-3-72564
Japanese Patent Laid-Open No. 4-239530, Japanese Patent Laid-Open No. 4-2530
Japanese Patent No. 39531 discloses that a semi-aromatic polyamide containing a polyamide composed of terephthalic acid and 1,6-hexanediamine (hereinafter abbreviated as PA6-T) as a main component can be used as an automobile part. However, PA6-T is 37 above the decomposition temperature of the polymer.
Since it has a melting point near 0 ° C., it is difficult to carry out melt polymerization and melt molding, and is not practical. Therefore, in practice, dicarboxylic acid components such as adipic acid and isophthalic acid, or aliphatic polyamides such as nylon 6 should be used.
Under the present circumstances, it is used in a composition in which the melting point is lowered to a practical usable temperature range, that is, about 280 to 320 ° C. by copolymerization of ˜40 mol%. Copolymerization of such a large amount of the third component (in some cases, the fourth component) is effective for lowering the melting point of the polymer, but on the other hand, it is accompanied by a decrease in crystallization rate and ultimate crystallinity. As a result, not only the physical properties such as rigidity at high temperature, chemical resistance, and dimensional stability are deteriorated, but also the productivity is deteriorated as the molding cycle is extended. In addition, with regard to changes in various physical properties such as dimensional stability due to water absorption, the introduction of aromatic groups
Although it is slightly improved as compared with the conventional aliphatic polyamide, it does not reach the level of practical problem solving.

JP-B-64-11073, JP-A-6-
2-36459, Japanese Patent Publication No. 1-19809,
JP-A-3-281532 discloses that, as the diamine component of the semi-aromatic polyamide, a linear aliphatic diamine having a longer chain can be used in addition to 1,6-hexanediamine. . However, these prior art documents do not specifically disclose a polyamide using 1,9-nonanediamine, and further, when 1,6-hexanediamine is used by using a diamine having 7 or more carbon atoms. There is no suggestion that particularly excellent performance will be exhibited as an automobile part in comparison with.

[0005]

[Problems to be Solved by the Invention]

The object of the present invention is not only excellent in heat resistance but also
It is an object of the present invention to provide a molding material for automobile parts, which has excellent properties such as low water absorption, toughness, chemical resistance, boiling water resistance, calcium chloride resistance, and light weight.

[0007]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the inventors of the present invention are the first to use a polyamide containing terephthalic acid and 1,9-nonanediamine as main components for the first time. , Heat resistance, low water absorption, toughness, chemical resistance, boiling water resistance, calcium chloride resistance,
And headings that can be obtained lightweight automobile parts forming material which is excellent in any of the performance and completed the present invention.

According to the present invention, the dicarboxylic acid component of 60
To 100 mol% of terephthalic acid and a diamine component of which 60 to 100 mol% of diamine component is 1,9-nonanediamine.
The intrinsic viscosity [η] measured at 0 ° C is 0.4 to 3.0 dl /
A molding material for automobile parts, which is made of polyamide in which 40% or more of the terminal groups are sealed , and is
The diamine component constituting the amide is 1,9-nonanediami
And 2-methyl-1,8-octanediamine
It is achieved by providing a molding material for automobile parts .

The present invention will be specifically described below. The polyamide serving as the base resin of the molding material for automobile parts of the present invention has a terephthalic acid component of 60 mol% or more, preferably 75 mol% or more, more preferably 90 mol% or more, of the dicarboxylic acid components used. is there. When the content of the terephthalic acid component is less than 60 mol%, various properties such as heat resistance, chemical resistance and boiling water resistance of the obtained polyamide are deteriorated, which is not preferable.

Other dicarboxylic acid components other than the terephthalic acid component include malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid,
Aliphatic dicarboxylic acids such as trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3,3-diethylsuccinic acid, azelaic acid, sebacic acid, suberic acid; 1,3-cyclopentanedicarboxylic acid, 1,4 An alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid;
Isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,
7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3
-Phenylenedioxydiacetic acid, diphenic acid, dibenzoic acid, 4,4'-oxydibenzoic acid, diphenylmethane-
4,4'-dicarboxylic acid, diphenyl sulfone-4,
Aromatic dicarboxylic acids such as 4'-dicarboxylic acid and 4,4'-biphenyldicarboxylic acid, or any mixture thereof can be mentioned. Of these, aromatic dicarboxylic acids are preferably used. Further, polyvalent carboxylic acids such as trimellitic acid, trimesic acid and pyromellitic acid can be used within the range where melt molding is possible.

As the diamine component used in the polyamide that is the base resin of the molding material for automobile parts of the present invention, the 1,9-nonanediamine component is 60 mol% or more, preferably 75 mol% or more, more preferably 90 mol% or more. It is at least mol%. If the composition of the diamine component is within this range, heat resistance, moldability, chemical resistance of the obtained polyamide,
It is preferable because it is excellent in low water absorption, light weight, and mechanical properties.

As diamine components other than the 1,9-nonanediamine component, ethylenediamine, propylenediamine, 1,4-butanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1,10-decanediamine. , 1,12-dodecanediamine, 3-methyl-
1,5-pentanediamine, 2,2,4-trimethyl-
1,6-hexanediamine, 2,4,4-trimethyl-
Aliphatic diamines such as 1,6-hexanediamine, 2-methyl-1,8-octanediamine, 5-methyl-1,9-nonanediamine; alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine and isophoronediamine; p -Aromatic diamines such as phenylenediamine, m-phenylenediamine, xylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone and 4,4'-diaminodiphenylether, or any mixture thereof. be able to. Among them, 2-methyl-1,8-octanediamine is preferable.

Base tree of the molding material for automobile parts of the present invention
The diamine component used for the polyamide that becomes fat is
2-Methyl-1,8 -octane with 9 -nonanediamine
Contains tandiamine. And contain in addition to these
Other diamine components that may be used include ethylenediamine, propylenediamine, 1,4-butanediamine,
1,6-hexanediamine, 1,8-octanediamine, 1,10-decanediamine, 1,12-dodecanediamine, 3-methyl-1,5-pentanediamine, 2,
2,4-trimethyl-1,6-hexanediamine, 2,
4,4-trimethyl-1,6-hexanediamine, 2-
Methyl-1,8-octanediamine, 5-methyl-1,
Aliphatic diamines such as 9-nonanediamine; alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine, isophoronediamine; p-phenylenediamine, m-phenylenediamine, xylenediamine,
Aromatic diamines such as 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfone and 4,4′-diaminodiphenyl ether, or any mixture thereof can be mentioned .

The amount of the end-capping agent used in the production of the polyamide used in the molding material for automobile parts of the present invention depends on the reactivity of the end-capping agent used, the boiling point, the reaction device,
Although it varies depending on the reaction conditions and the like, it is usually used within the range of 0.1 to 15 mol% with respect to the total number of moles of the dicarboxylic acid and the diamine.

The polyamide used in the molding material for automobile parts of the present invention can be produced by any method known as a method for producing a crystalline polyamide. For example, the polymerization can be carried out by a solution polymerization method using an acid chloride and a diamine as raw materials or an interfacial polymerization method, a melt polymerization method using a dicarboxylic acid and a diamine as raw materials, a solid phase polymerization method, a melt extruder polymerization method and the like. Below, an example of the polymerization method of polyamide is shown.

According to the research conducted by the present inventors, a catalyst and, if necessary, an end-capping agent were first added to a diamine and a dicarboxylic acid all at once, to prepare a nylon salt, and then once at 200 to 250 ° C. 30 ℃ in concentrated sulfuric acid at the temperature of
Viscosity [η] at 0.10 to 0.60 dl / g
The polyamide of the present invention can be easily obtained by subjecting the prepolymer of (1) to solid phase polymerization or performing polymerization using a melt extruder. When the intrinsic viscosity [η] of the prepolymer is within the range of 0.10 to 0.60 dl / g, the deviation of the molar balance between the carboxyl group and the amino group and the decrease in the polymerization rate are small in the post-polymerization stage, and the molecular weight is further reduced. A polyamide with a small distribution and excellent performance and moldability can be obtained. When the final stage of the polymerization is carried out by solid phase polymerization, it is preferably carried out under reduced pressure or under the flow of an inert gas, and if the polymerization temperature is in the range of 200 to 280 ° C., the polymerization rate is high and the productivity is excellent. It is preferable because coloring and gelation can be effectively suppressed. When the final stage of polymerization is carried out by a melt extruder, the polymerization temperature is 370 ° C.
It is preferable for it to be less than that the polyamide is hardly decomposed and a polyamide without deterioration can be obtained.

The [η] of the polyamide thus obtained, measured in concentrated sulfuric acid at 30 ° C., is 0.4 to 3.0 dl / g.
And preferably 0.6 to 2.0 dl / g, and more preferably 0.8 to 1.8 dl / g. When [η] is in this range, the obtained polyamide has good mechanical performance and moldability, which is preferable.

In the production of the above polyamide, in addition to the above-mentioned terminal blocking agent, for example, as a catalyst, phosphoric acid, phosphorous acid, hypophosphorous acid or a salt or ester thereof,
Specifically, potassium, sodium, magnesium, vanadium, calcium, zinc, cobalt, manganese, tin,
Metal salts such as tungsten, germanium, titanium and antimony, ammonium salts, ethyl ester, isopropyl ester, butyl ester, hexyl ester, isodecyl ester, octadecyl ester, decyl ester, stearyl ester, phenyl ester and the like can be added.

The molding material for automobile parts of the present invention preferably contains 10 to 200 parts by weight of glass fiber as an additive with respect to 100 parts by weight of polyamide. The glass fiber is made of non-alkali borosilicate glass or C-glass containing alkali and has a diameter of 3 μm to 30 μm.
m, long fibers with a length of 5 to 50 mm, or short fibers with a length of 0.05 to 5 mm can be used. Further, the surface of these glass fibers may be processed with a silane coupling agent or the like. The blending amount of the glass fiber is 10 to 200 parts by weight, preferably 15 to 100 parts by weight, based on 100 parts by weight of polyamide. If the blending amount of glass fiber is within this range,
Various properties such as mechanical strength can be improved while maintaining moldability to some extent. If the amount of glass fiber is more than 200 parts by weight, the melt fluidity is significantly reduced and the moldability is significantly reduced. On the other hand, if the amount is less than 10 parts by weight, sufficient improvement in various performances cannot be seen. Usually, these glass fibers are blended with the polyamide by using a uniaxial or biaxial extruder and simultaneously introducing the polyamide from the hopper or the side feeder.

The molding material for automobile parts of the present invention may contain, in addition to glass fiber, carbon fiber, inorganic powder filler, organic powder filler and the like.

Further, in addition to the above-mentioned additives, the molding material for automobile parts of the present invention may contain, if necessary, a hindered phenol antioxidant, a hindered amine antioxidant, a phosphorus antioxidant, and a thiol antioxidant. Antioxidants, colorants, UV absorbers, light stabilizers, antistatic agents, plasticizers, lubricants,
Crystal nucleating agents, flame retardants, other polymers, etc. can also be added.

Examples of the method of blending the above-mentioned respective constituents include a method of adding during the polycondensation reaction of polyamide or a method of dry blending before molding, a method of melt-kneading blending using an extruder, and the like.

As described above, the molding material for automobile parts of the present invention has excellent heat resistance, mechanical strength, toughness,
It has excellent impact resistance, low water absorption, chemical resistance, boiling water resistance, calcium chloride resistance, and lightness, and is a very excellent molding material when used as automobile parts. Specific examples of suitable usage include cylinder head covers, oil pump housings, link bushes, intake manifolds, delivery pipes, PCV valves, radiator tanks, headlamp reflectors, and the like.

[0024]

EXAMPLES Hereinafter, the molding material for automobile parts of the present invention will be specifically described by way of examples, but the present invention is not limited thereto. The terminal sealing rate, intrinsic viscosity, specific gravity, tensile strength, tensile elongation, equilibrium water absorption rate, boiling water resistance, calcium chloride resistance, and alcohol resistance in the examples were measured by the following methods.

End capping ratio: ¹ H-NMR (500 MH
z, measured in deuterated trifluoroacetic acid at 50 ° C.) to measure the number of carboxyl group end, amino group end and capped end respectively from the integrated value of the characteristic signal for each end group, The terminal sealing rate was calculated from (1). The chemical shift values of typical signals used for measurement are shown below. Sealing rate (%) = [(A−B) ÷ A] × 100 (1) [In the formula, A is the total number of end groups of molecular chain (this is usually equal to twice the number of polyamide molecules). And B represents the total number of carboxyl group terminals and amino group terminals.]

[0026]

[Table 1]

Intrinsic viscosity [η]: in concentrated sulfuric acid at 30 ° C.
The intrinsic viscosity (ηinh) of the samples having the concentrations of 0.05, 0.1, 0.2 and 0.4 g / dl was measured, and the value obtained by extrapolating this to the concentration of 0 was defined as the intrinsic viscosity [η]. ηinh = [ln (t ₁ / t ₀ )] / c [wherein, ηinh represents an intrinsic viscosity (dl / g), t ₀ represents a solvent flowing time (second), and t ₁ represents a sample solution flowing down. Time (second), c is the concentration of the sample in the solution (g / dl)
Represents ]

Specific gravity: Measured using a density gradient tube.

Tensile Strength, Tensile Elongation, Impact Strength: A sample piece in an absolutely dry state injection-molded at a temperature about 20 ° C. higher than the melting point of polyamide was measured by the following method.

[0030]

[Table 2]

Equilibrium water absorption: 20 ° C. from the melting point of polyamide
It was hot pressed at high temperature and cooled at 150 ° C. for 5 minutes. Film with a thickness of about 200 μm (5 cm x 5 cm)
Was dried under reduced pressure at 120 ° C. for 5 days, weighed,
It was dipped in water at 23 ° C. for 10 days, weighed, and determined as a ratio (%) of the increased amount to the weight before immersion.

Boiling water resistance: about 20 ° C. from the melting point of polyamide
A sample piece, which was hot-pressed at a high temperature and punched out with a film having a thickness of 200 microns using JIS No. 3 dumbbells, was heated to 80 ° C.
Was immersed in hot water for 10 minutes and the retention rate of the tensile strength of the sample before treatment was measured.

Calcium chloride resistance, alcohol resistance: hot pressed at a temperature about 20 ° C. higher than the melting point of polyamide,
A sample piece obtained by punching out a film having a thickness of 200 microns with a JIS No. 3 dumbbell was immersed in a 50% aqueous solution of calcium chloride at 23 ° C. or methanol for 7 days to measure the retention of tensile strength of the sample before treatment.

Reference Example 1 3272.9 g (19.70 mol) of terephthalic acid, 1,
3165.8 g (20.0 mol) of 9-nonanediamine,
73.27 g (0.60 mol) of benzoic acid, 6.5 g of sodium hypophosphite monohydrate (0.1% by weight with respect to the raw material) and 6 liters of distilled water were placed in an autoclave having an internal volume of 20 liters, The atmosphere was replaced with nitrogen. The mixture was stirred at 100 ° C for 30 minutes, and the internal temperature was raised to 210 ° C over 2 hours. At this time, the pressure in the autoclave was increased to 22 kg / cm ² . After continuing the reaction for 1 hour, the temperature was raised to 230 ° C., and then the temperature was maintained at 230 ° C. for 2 hours, and the reaction was performed while gradually removing steam to maintain the pressure at 22 kg / cm ² . Next, the pressure is reduced to 10 kg / cm ² over 30 minutes, and the reaction is continued for 1 hour to obtain an intrinsic viscosity [η] of 0.2.
A prepolymer of 5 dl / g was obtained. This is 100 ℃,
It was dried under reduced pressure for 12 hours and crushed to a size of 2 mm or less. This is solid-phase polymerized at 230 ° C. and 0.1 mmHg for 10 hours, and has a melting point of 317 ° C. and an intrinsic viscosity [η] of 1.
A white polyamide having 35 dl / g and a terminal sealing rate of 90% was obtained. Next, this polyamide was injection-molded at a cylinder temperature of 340 ° C. and a mold temperature of 100 ° C., and various physical properties of the obtained molded product were measured. The results obtained are shown in Table 3 below.

Reference Example 2 In Reference Example 1, 3239.6 g (1
9.5 mol), 122.1 g (1.0 mol) of benzoic acid
A polyamide was produced by the method described in Example 1 except that Next, the polyamide and glass fiber having an average length of 6 mm (PPG3540, made of PPG) are dry blended,
Single-screw extruder (screw diameter 40 mm, L / D = 28, cylinder temperature = 320 to 350 ° C., rotation speed = 60 rp)
Compounding was performed in m). The glass fiber compound thus obtained was injection molded at a cylinder temperature of 340 ° C. and a mold temperature of 100 ° C., and various physical properties of the obtained molded product were measured. The results obtained are shown in Table 3 below.

Reference Example 3 In Reference Example 2, 3405.8 g of terephthalic acid (2
0.5 mol), except that benzoic acid was not used, the glass fiber reinforced polyamide and its molded article were produced by the method described in Example 2, and various physical properties were measured. The results obtained are shown in Table 3 below.

Example 1 In Reference Example 2, 3256.2 g (1
9.6 mol) and 97.7 g (0.8 mol) of benzoic acid are used, and 1,9-nonanediamine is 2 as a diamine component.
849.2 g (18.0 mol), 2-methyl-1,8-
A glass fiber reinforced polyamide and a molded article thereof were produced by the method described in Reference Example 2 except that 316.58 g (2.0 mol) of octanediamine was used, and various physical properties were measured. The results obtained are shown in Table 3 below.

Comparative Example 1 In Example 1, 2325.9 g of terephthalic acid (1
4.0 mol), isophthalic acid 996.8 g (6.0 mol), 1,6-hexanediamine 2324.2 g (2
0.0 mol), benzoic acid 24.43 g (0.20 mol)
Except for the above, polyamide and molded articles thereof were manufactured by the method described in Example 1 and various physical properties were measured. The results obtained are shown in Table 3 below.

Comparative Example 2 The polyamide obtained in Comparative Example 1 was mixed with glass fiber by the method described in Example 2 and injection-molded. The results obtained are shown in Table 3 below.

[0040]

[Table 3]

[0041]

EFFECT OF THE INVENTION The polyamide-based molding material of the present invention has excellent heat resistance as well as excellent properties such as low water absorption, toughness, chemical resistance, boiling water resistance, calcium chloride resistance and light weight. It can be suitably used for parts.

Continuation of the front page (56) Reference JP-A-3-7761 (JP, A) JP-A-4-366168 (JP, A) JP-A-7-224164 (JP, A) JP-A-62-36459 (JP , A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08L 77/00-77/12 C08G 69/26-69/36 C08K 7/14

Claims (2)

(57) [Claims] 1. 60 to 100 mol% of the dicarboxylic acid component
Is a terephthalic acid component and a diamine component in which 60 to 100 mol% of the diamine component is 1,9-nonanediamine, and the intrinsic viscosity [η] measured in concentrated sulfuric acid at 30 ° C. is 0.4 to A molding material for automobile parts, comprising 3.0% dl / g and having 40% or more of the end groups sealed , which constitutes the polyamide.
Diamine component is 1,9-nonanediamine and 2-methyl
Automotive parts containing -1,8-octanediamine
Molding material. 2. 60 to 100 mol% of the dicarboxylic acid component
Is a terephthalic acid component and a diamine component in which 60 to 100 mol% of the diamine component is 1,9-nonanediamine, and the intrinsic viscosity [η] measured in concentrated sulfuric acid at 30 ° C. is 0.4 to was 3.0 dl / g, more than 40% of the terminal groups is a molding material for automobile parts made of 100 parts by weight of glass fiber from 10 to 200 parts by weight of polyamide sealed, Zia constituting the polyamide
Min component is 1,9-nonanediamine and 2-methyl-
Composition for automobile parts containing 1,8-octanediamine
Shaped material.