JPH0339356A - Underhood part for automobile - Google Patents

Abstract

PURPOSE:To provide an automotive underhood part having excellent heat resistance and rigidity and having large resistance against road anti-freezing agents by molding a resin composition mainly comprising nylon 46 and a specific amorphous aromatic polyamide resin. CONSTITUTION:A composition comprising (A) 20-99wt.% of nylon 46, (B) 1-80wt.% of an amorphous aromatic polyamide resin composed from a bis(4- aminocyclohexyl)alkane derivative of the formula (R1 and R2 are H or 1-3C alkyl), aromatic dicarboxylic acid and other aliphatic copolymers and (C) 0-70wt.% of an inorganic reinforcing material (e.g. glass fibers) is molded to provide the objective part.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an underhood part for an automobile formed by molding a resin phase acid product whose main components are nylon 4G resin and amorphous aromatic polyamide resin. .

More specifically, the present invention relates to underhood parts for automobiles that have excellent heat resistance and rigidity, and excellent durability against metal halides such as calcium chloride and magnesium chloride, which are the main components of road antifreeze agents.

(Prior Art) There has been a noticeable trend in the automobile industry to replace conventional metal parts with resin for the purpose of weight reduction, rust prevention, sound insulation, etc. to improve fuel efficiency. Among these, polyamide resins have remarkable characteristics such as heat resistance, oil resistance, moldability, and toughness, and are therefore attracting attention for application to automobile underhood parts.

In the present invention, underhood parts for automobiles refer to parts that are installed below the hood of a car, that is, the bonnet or bottom plate, and are exposed to water splashed up from the road surface and chemicals such as anti-freezing agents. That's true. Particularly suitable are parts in the engine room, brake piping, fuel piping, etc. Specifically, cooling fans, radiator tank tops and bases, cylinder head covers, oil pans, timing chain cover ties, etc.
belt force bar, gear box cover water pump housing, steering column rotary housing, twill filter paper canister, brake reservoir, gears in engine room parts, pulp and connectors, electrical parts such as fastener clips, fuel pipes, vacuum pipes, A meritorious clutch horse.

Air brake lines, car cooler hoses, etc.

However, polyamide resins with a relatively high concentration of amide groups, such as nylon 6 resin and nylon 66 resin, which are commonly used among polyamide resins, inherently have a strong affinity for inorganic metal salts such as calcium chloride and zinc chloride. Therefore, automotive underhood parts made from these materials contain calcium chloride.

It has a serious drawback that it is attacked by metal salts such as magnesium chloride and zinc chloride and cracks occur within a short period of time.

In general, large amounts of antifreeze agents containing calcium chloride, magnesium chloride, etc. are sprayed on roads in cold regions to prevent road surfaces from freezing, especially in winter. If it adheres to underhood parts, it will cause cracks in the parts, so
There is a high risk of a car accident resulting from this. Therefore, automobile underhood parts made of nylon 6 resin, nylon 66 resin, etc. have excellent toughness and relatively high heat resistance, and although they are inexpensive, they are not sufficiently resistant to road deicing agents, so they are not widely used. The emergence of polyamide-based materials with limited expansion and excellent road antifreeze resistance has been awaited.

Furthermore, in the automobile industry, efforts have been made to increase the output of engines, and the proportion of automobiles equipped with high-output engines has been rapidly increasing in recent years. Temperature inside the engine room of cars equipped with these engines, especially engine fNI
22 The temperature becomes extremely high.

Therefore, there has been a demand for further improvement in heat resistance for underhood parts, and there have been cases where conventional automotive underhood parts made of nylon 6 resin or nylon 66 resin have insufficient heat resistance.

In view of these circumstances, Japanese Patent Laid-Open No. 59-117532 proposes the use of nylon 46 resin for parts around the engine. However, although nylon 46 resin has excellent heat resistance and rigidity, it has a drawback that it has poor durability against icy roads due to its high concentration of amide groups.

This is an attempt to improve the durability of nylon 6 and nylon 66 resins against road antifreeze agents.

Method of blending modified polyolefin (Japanese Patent Application Laid-Open No. 61765
40), method of blending aromatic polyamide (JP-A-58-53949, JP-A-58-53950, JP-A-58-120665, JP-A-63-
No. 205353), etc., are known, but their road antifreeze properties are insufficient, and in view of the recent rise in engine compartment temperatures, further improvement in heat resistance is desired.

(Problems to be Solved by the Invention) In view of the above circumstances, an object of the present invention is to provide an underhood part for an automobile that has excellent heat resistance and rigidity, and has high resistance to road antifreeze agents.

(Means for Solving the Problems) As a result of intensive research by the present inventors for this purpose, nylon 4
An underhood part for an automobile formed by molding a resin composition comprising a 6 resin, a specific amorphous aromatic boria chloride resin, and an inorganic reinforcing material as necessary satisfies all the objects of the present invention. Heading This is what has led to the present invention.

That is, 8 the present invention is (8) nylon 46 resin 20-99
Weight %, (B) Amorphous aromatic polyamide resin 1 to 1 consisting of a bis(4-aminocyclohexyl)alkane conductor represented by the general formula [■], aromatic dicarboxylic acid, and other aliphatic copolymer components 80% by weight (However, R1 and R in one formula
1 may be the same or different, and each represents hydrogen or an alkyl group of c1 to c3. ) (C) An underhood part for an automobile formed by molding a resin composition comprising O to 70% of an inorganic reinforcing material.

The (^) nylon 46 resin used in the present invention includes polytetramethylene adipamide obtained from tetramethylene diamine and adipic acid and a copolyamide whose main constituents are polytetramethylene adipamide units. Additionally, other polyamides may be included as mixed components without impairing the properties of nylon 46. The copolymerization component is not particularly limited, and known amide-forming components can be used. Typical examples of copolymerizable components include 6-aminocaproic acid, 11-aminoundecanoic acid, 12-anododecanoic acid, and aminoacids such as varaminomethylbenzoic acid.

Lactams such as ε-caprolactam and ω-lauryllactam, hexamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2゜4-/2,
4.4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, metaxylylene cyanide,
Baraxylylene, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, l-amino-3-aminomethyl-3,5
, 5-trimethylcyclohexane, bis(3-methyl-
4-aminocyclohexyl)methane, 2,2-bis(4
-Diamines such as aminocyclohexyl)propane, bis(aminopropyl)piperazine, and aminoethylpiperazine, and adipic acid, speric acid, azelaic acid, sebacic acid, dodecanionic acid, terephthalic acid, isofucric acid, 2-
Examples include dicarboxylic acids such as chlorterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, diglycolic acid, etc. Also, as a mixed component Other polyamides that can be used include those consisting of these components.

Any method can be used for producing the nylon 46 resin used in the present invention. For example, Japanese Patent Application Laid-open No. 149430/1983.

JP-A-56-149431, JP-A-58-830
29 and JP-A-61-43631.

In other words, first, a prepolymer with few cyclic end groups is produced under specific conditions, and then this is solid-phase polymerized in a steam atmosphere to form high viscosity nylon 46 resin Bp4, or 2-pyrrolidone or N-methyl There is a method of obtaining it by heating in a polar organic solvent such as pyrrolidone. There are no particular restrictions on the degree of polymerization of nylon 46 resin, but 30°
The relative viscosity at 1 g/d°C in C196% sulfuric acid is 2.
Nylon 46 resin having a hardness within the range of 0 to 6.0 is preferably used.

The (n) amorphous aromatic boria ξ-do resin used in the present invention is a bis(4-aminocyclohexyl)alkane derivative represented by the general formula CI), an aromatic dicarboxylic acid, and other aliphatic copolymer components. It can be obtained from

(However, in formula 1, R1 and R2 may be the same or different and each represents hydrogen or an alkyl group of 01 to C1.) Bis(4-aminocyclohexyl)alkane derivative represented by general formula (N) A specific example of this is Keha.

Bis(4-aminocyclohexyl)methane, bis(4-
Aminochlorohexyl)propane, bis(4-amino-
3-Methylcyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)propane, bis(4-a≧no3,5-dimethylcyclohexyl)methane, bis(4-ami)3.5-dimethylcyclohexyl)propane , bis(4-amino-3-methyl-5-nitylcyclohexyl)methane, bis(4-amino-3-methyl-5
-ethylcyclohexyl)propane, bis(4-amino-3,5-diethylcyclohexyl)methane, bis(4
-amino-3,5-diethylcyclohexyl)propane, bis(4-amino-3-methyl-5-isopropylcyclohexyl)methane, bis(4-amino-3-methyl-5-isopropylcyclohexyl)propane, bis(
4-7mino-3,5-diisopropylcyclohexyl)
Methane, bis(4-amino-3,5-diisopropylcyclohexyl)propane, bis(4-amino-3-ethylcyclohexyl)methane, bis(4-amino-3-ethylcyclohexyl)propane.

Bis(4-amino-3-isopropylcyclohexyl)
Examples include methane, bis(4-amino-3-isopropylcyclohexyl)propane, and the like.

A specific example of the aromatic dicarboxylic acid constituting the amorphous aromatic polyester resin is isophthalic acid.

Terephthalic acid, naphthalene dicarboxylic acid, and mixtures thereof are representative, and isophthalic acid or a mixture of isophthalic acid and terephthalic acid is particularly preferably used.

Another aliphatic copolymer component constituting the amorphous aromatic polyamide resin is 6-aminocaproic acid.

Amino acids such as 11-aminoundecanoic acid, 512-aminododecanoic acid, lactams such as ε-caprolactam and ω-lauryllactam, hexamethylene cyanine, undecamethylene diamine, dodecamethylene diamine, 2,2.
Fats such as -72,4,4-1-limethylhexamethylenediamine, 5-methylnonamethylenecyan, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane There are aliphatic dicarboxylic acids of the group cyanide, adipic acid, sperate azelaic acid, sebacic acid, dodecanoic acid, and the like.

The amorphous aromatic polyamide resin used in the present invention is prepared by first reacting a diamine component and a dicarboxylic acid component in water to form a salt, which is then concentrated.

Polycondensation is carried out by a known method. Salt solution 1i: j,
Preferably, first in a closed autoclave at 200°C.
Precondensation is carried out under reaction pressure in the range of ~300°C, 2nd the pressure is released, and ii) the reaction is carried out under atmospheric pressure or reduced pressure until a polycondensation equilibrium is reached.

In order to obtain good physical properties, the relative viscosity of the amorphous aromatic polyamide resin (1 weight percent of the amorphous aromatic polyamide resin)
(measured at 20°C using m-cresol solution) is 1.2
It is desirable that it be in the range of ~2.5. In order to adjust the relative viscosity of the amorphous aromatic polyamide resin, it is also possible to add known monofunctional amines or carboxylic acids during polymerization. The amorphous aromatic polyamide resin thus obtained exhibits no melting point and is completely transparent.

(c)=Mechanical reinforcing material used in the present invention is glass horizontal cord, asbestos fiber, carbon fiber, and calcium carbonate.

Talc magnesium monooxide, aluminum oxide.

Examples include wollastenite, fine mica granular glass, and potassium titanate whiskers.

Such inorganic reinforcements are used particularly when it is necessary to increase stiffness and heat resistance.

The automotive underhood parts of the present invention include (A) 20 to 99 weight percent of nylon 46 citrus, (B) 1 to 80 weight percent of amorphous aromatic boria ξ resin, and (C) 0 to 70 weight percent of inorganic reinforcing material. It can be obtained by molding a resin composition consisting of % by weight.

Here, as the weight percent of (A) nylon 46 resin increases, the heat resistance improves, but the road freeze agent resistance decreases. The opposite trend is observed as the weight percent of amorphous aromatic polyamide resin increases. Therefore, (A) nylon 46 resin and (
B) It is possible to control the blending ratio of the amorphous aromatic polyamide resin. (8) There are no particular restrictions on the method of blending the nylon 46 resin, (B) the amorphous aromatic polyamide resin, and (C) the inorganic reinforcing material. -1 powder,
A method of uniformly mixing fine pieces, etc. and a reinforcing material with a high-speed stirrer, and then melt-kneading with an extruder having sufficient kneading capacity, a method of tri-blend injection or extrusion molding, etc. can be used.

The underhood part for an automobile of the present invention is molded by subjecting the resin composition to a molding method generally known for thermoplastic resins such as injection molding, extrusion molding, blow molding vacuum molding, etc., but in particular injection molding or extrusion molding. Cooling fan, radiator tank, and cylinder throat cover obtained by molding. Electrical system parts such as oil pans, gears, valves, brake piping, fuel piping, other tubes, pipes, other exhaust gas system parts, and connectors.

Sheets etc. are useful. Note that the molded parts obtained in this manner can also be subjected to secondary processing such as painting, vapor deposition, adhesion, etc.

Furthermore, the present invention may be applied to the underhood parts for automobiles as long as the moldability and physical properties thereof are not impaired.

Other components such as pigments, dyes, heat-resistant agents, oxidation amount 1L agents, weathering agents, lubricants, crystal nucleating agents, charge amount IL agents, plasticizers, other polymers, etc. can be added and introduced.

Furthermore, for the purpose of increasing road freeze resistance.

Acid-modified polyolefins, such as acid anhydride-modified polyolefins, ethylene-based ionomer resins or epoxy group-containing polyolefins, as well as rubber materials having a glass transition temperature of 0"C or lower, may be blended into the underhood parts for automobiles of the present invention. It is possible.

(Example) Hereinafter, the present invention will be further explained in detail by giving Examples.

The performance of the test pieces described in Examples was measured in the following manner.

Tensile test: 437M D638 rlI] Ge test: 437M 0790 Izotsu Street! Il test: AST? I D256 heat distortion temperature test: 437M 0648 Road antifreeze test: After immersing the cylinder head cover molded product obtained by injection molding in warm water at 9o'C for 24 hours, it was left in a gear oven at 100'C. ,
The number of cycles until cracks appeared in the molded product was measured, with one cycle being a process in which a 50% calcium chloride solution was sprayed every hour.

Reference example 1: Amorphous aromatic boria resin isophthalic acid 4
8 kg of 10 kg of raw materials containing 5 mol % of terephthalic acid, 45 mol % of hexamethylenediamine, and 5 mol % of bis=(4-methylcyclohexyl)methane.
The reactor was charged with pure water, and the air in the reactor was purged several times with nitrogen. After raising the temperature to 90°C and reacting for about 5 hours, the reaction temperature was gradually increased to 28°C over 10 hours.
The tank was raised to 0''C under pressure (18 bar) while stirring.Then, the pressure was released and the pressure was lowered to atmospheric pressure.

Polymerization was further carried out at the same temperature for 6 hours. After the reaction was completed, it was discharged from the reaction vessel and cut to obtain a pellet.

The relative viscosity of the pellet obtained (same method as above) is 1
．． It was 50. Further, the glass transition temperature was 150°C. This amorphous aromatic polyamide resin is designated as P1.

Examples 1 to 4 Nylon 46 resin (manufactured by Unitika, Nylon 46 F5000) having a relative viscosity of 3.5 in Ig/dffi in 30'C, 96% sulfuric acid and the amorphous aromatic polyamide of Reference Example 1 Resin P-1 and chopped strand glass fiber (manufactured by Nippon Electric Glass Co., Ltd., T-289) were mixed in the proportions shown in Table 1, and these were dried in a vacuum dryer at 95°C.
It was dried for 6 hours. Next, these mixed raw materials were melt-kneaded in a twin-screw extruder with a diameter of 45 mm, and then formed into pellets.

After drying this pellet again in a vacuum dryer at 95°C for 16 hours, it was molded into various physical property test pieces using an injection molding machine.
50mm, width 200mm, height 70mm, average wall thickness 3.
A 3mm box-shaped cylinder head cover was molded. The injection molding conditions at this time were a cylinder temperature of 310"C.

The mold temperature was 100°C. Various performance evaluations were carried out using the test piece obtained here and a rad cover for the cylinder. The results are also listed in Table 1.

As specifically shown in Table 1, these exhibited excellent performance as underhood parts for automobiles.

Table ■ Comparative Examples 1 to 4 The same nylon 46 resin used in Examples 1 to 4, chopped strand glass fiber, and nylon 66 resin Hc
Maranyl Al25) manufactured by T Company was mixed in the proportions shown in Table 2, and these were dried in a vacuum dryer at 95°C for 16 hours.

Next, these were melt-kneaded using a twin-screw extruder with a diameter of 45 mm to form pellets.

After drying this pellet again in a vacuum dryer at 95° C. for 16 hours, the same test pieces and cylinder head covers as in Examples 1 to 4 were molded using an injection molding machine.

The molding conditions at this time were that Comparative Example 1.2 had a cylinder temperature of 3.
10°C9 Mold temperature 100''C1 Comparative example 3.4 had a cylinder temperature of 280°C1 Mold temperature of 80°C. Various performance evaluations were performed using the obtained test piece and cylinder with a rad cover. The results are listed in Table 2.As specifically shown in Table 2, Comparative Example 1.2 has poor road antifreeze resistance, and Comparative Example 3.4 has poor road antifreeze resistance and heat resistance. inferior to

Table (Effects of the Invention) As specifically shown in the examples, the underhood parts for automobiles of the present invention are produced by molding a resin composition consisting of nylon 46 resin and a specific amorphous aromatic boria ξ-do resin. In addition to its excellent heat resistance and rigidity, it also has excellent road antifreeze properties.

Claims (1)

[Claims] (1) (A) 20-99% by weight of nylon 46 resin, (B
) 1 to 80% by weight of an amorphous aromatic polyamide resin consisting of a bis(4-aminocyclohexyl)alkane derivative represented by the general formula [I], an aromatic dicarboxylic acid, and other aliphatic copolymer components ▲Math. There are chemical formulas, tables, etc.▼〔I〕 (However, in the formula, R_1 and R_2 may be the same or different, and each represents hydrogen or C_1 to C_3.
represents an alkyl group. (C) An underhood part for an automobile formed by molding a resin composition containing 0 to 70% by weight of an inorganic reinforcing material.