JP3082456B2 - Moldings and underhood parts for automobiles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The molded article of the present invention is obtained by hollow molding and has excellent vibration damping properties, light weight, and heat resistance.

[0002]

2. Description of the Related Art In recent years, there has been a remarkable tendency in the automotive industry to convert conventional metal parts into resin for the purpose of reducing weight, improving rust prevention and sound insulation for improving fuel efficiency. Among them, polyamide resins have excellent heat resistance, oil resistance, moldability, toughness and other characteristics, so they can be used in automobile underhood parts, such as cooling fans, radiator tank tops and bases, cylinder head covers, and oils. Attention has been focused on applications to various functional components such as pans, gears, valves, brake piping, tubes for fuel piping, other exhaust system components, and electrical components such as connectors. Recently, the demand for vibration damping and weight reduction has become even higher,
At present, conventional polyamide resins cannot sufficiently meet this requirement.

[0003]

SUMMARY OF THE INVENTION The present invention solves the problem of insufficient vibration damping and lightening of a molded article of a polyamide resin, and provides a molded article excellent in vibration damping, light weight and heat resistance. The purpose is to provide.

[0004]

The molded article according to claim 1 is a thermoplastic resin (B) having a polyamide resin (A) of 25 to 98% by weight and a glass transition point of 0 ° C. or higher (B).
Except for (A). ) Resin (C) consisting of 75 to 2% by weight
A resin composition obtained by mixing 2 to 250 parts by weight of a filler (D) with 100 parts by weight is hollow-formed, and has a hollow ratio of 5 to 50%.
It is characterized by having . The molded article according to claim 2 is a thermoplastic resin (B) having a polyamide-based resin (A) of 25 to 98% by weight and a glass transition point of 0 ° C or more (however,
Except for (A). ) Resin (C) consisting of 75 to 2% by weight
The resin composition obtained by mixing 2 to 250 parts by weight of the filler (D) with 100 parts by weight is subjected to gas injection molding . The molded article is particularly suitable as an automobile underhood component (claim 3). Hereinafter, the present invention will be described in detail. As the polyamide resin component (A), an aliphatic polyamide-series resin is preferable, H _{2
N- (CH 2) x -NH 2} ( wherein, x is 3-12 integer) linear diamine represented by, HOOC- _(CH 2)
Those produced by condensation with a linear dicarboxylic acid represented by _y- COOH (in the formula, y is an integer of 2 to 12) or those produced by ring-opening polymerization of a lactam can be used.

Preferred examples of these polyamide resins (A) include nylon 6,6, nylon 6,10, nylon 6,12, nylon 4,6, nylon 3,4, nylon 6,9, nylon 6, Nylon 12, Nylon 1
1, nylon 4, and the like. In addition, nylon 6 /
6,10, nylon 6 / 6,12, nylon 6/4
6, nylon 6/12, nylon 6/6, 6 ', nylon 6/6, 6/6, 10, nylon 6/4, 6/6,
6, nylon 6/6, 6/6, 12, nylon 6/4
Copolymer polyamides such as 6/10 and nylon 6/4, 6/12. Although the degree of polymerization of the polyamide resin (A) used here is not particularly limited, a preferable relative viscosity is 2 to 5. The polyamide resin (A) is used alone or in combination of two or more.

The thermoplastic resin (B) having a glass transition temperature of 0 ° C. or higher according to the present invention is a thermoplastic resin other than the component (A). The thermoplastic resin used as the component (B)
It is a polymer having a glass transition temperature of 0 ° C. or higher, and includes an amorphous polymer, a crystalline polymer, a liquid crystal polymer, and the like.
Specifically, styrene resin, vinyl chloride resin, acrylic resin, polyphenylene ether resin, polyarylene sulfide resin, polycarbonate resin, polyester resin, amorphous polyamide resin, polyether sulfone resin, polysulfone resin, polyimide Resins and the like can be mentioned.

The styrene resin of the present invention includes, for example, polystyrene, polychlorostyrene, polyα-methylstyrene, styrene-acrylonitrile copolymer, styrene-methyl methacrylate copolymer, styrene-maleic anhydride copolymer Styrene-α-methylstyrene copolymer, styrene-α-methylstyrene-methyl methacrylate copolymer, styrene-α-methylstyrene-acrylonitrile-methyl methacrylate copolymer, styrene-maleimide copolymer, styrene- Maleimide-acrylonitrile copolymer, styrene-maleic acid-phenylmaleimide copolymer and the like can be mentioned, and not only one kind thereof but also two or more kinds thereof can be used.
Examples of the vinyl chloride resin useful in the present invention include polyvinyl chloride, vinyl chloride, and 50% by weight or less, preferably 45% by weight or less of a compound having at least one double bond copolymerizable with vinyl chloride. Copolymers can be mentioned. This copolymerizable double bond has at least one
Specific examples of the compound having the same include vinylidene chloride, ethylene, propylene, vinyl acetate, (meth) acrylic acid and their esters, maleic acid and their esters, and acrylonitrile. The polymerization degree of the vinyl chloride resin is usually 400 to 4
500, and particularly preferably 400 to 1500. The vinyl chloride resin is obtained by (co) polymerizing vinyl chloride alone or with vinyl chloride and the copolymerizable compound in the presence of a free radical catalyst, and its production method is widely known. ing.

The polyarylene sulfide resin of the present invention contains at least 70 mol% of a structural unit represented by the formula-(Ar-S)-. Here, Ar is p
-Phenylene, m-phenylene, 2,6-naphthalene,
Represents an aromatic group having 6 or more carbon atoms, such as 4,4'-biphenylene, p, p'-bibenzyl, and a nuclear substituted product thereof. Of these, the nucleus-unsubstituted p-phenylene nucleus, ie, the formula:

[0009]

Embedded image Poly-p-phenylene sulfide having a structural unit represented by the following formula (1) is preferred from the viewpoint of moldability. Formula-(Ar-
When a resin having a structural unit represented by S)-of less than 70 mol% is used, undesired results such as a decrease in crystallinity of the obtained polymer, a decrease in transfer temperature, and a decrease in physical properties of a molded article are produced. If less than 30 mol%, 1,2,4
-An aromatic group, an aliphatic group, a hetero atom-containing group or the like having a bond of three or more valences such as a bonded phenylene nucleus may be contained.

The method for producing the above polyarylene sulfide resin includes a condensation reaction of a dihalogenated aromatic compound with a dithiol aromatic compound or a monohalogenated aromatic thiol, or a dihalogenated aromatic compound with an alkali sulfide or hydrosulfide. A method utilizing a desalination condensation reaction of an alkali and an alkali or a hydrogen sulfide and an alkali compound can be exemplified, but the method is not limited thereto. Examples of the polycarbonate resin of the present invention include an aromatic polycarbonate resin, an aliphatic polycarbonate resin, and an aliphatic-aromatic polycarbonate resin. Generally, 2,2-bis- (4-
A polymer or copolymer obtained by polymerizing a bisphenol such as (oxyphenyl) alkane, bis (4-oxyphenyl) ether, bis (4-oxyphenyl) sulfone sulfide or sulfoxide, It is a polymer using bisphenols substituted by halogens accordingly. For the type and production method of the polycarbonate resin, for example, the description of “Polycarbonate resin” published by Nikkan Kogyo Shimbun (published on September 30, 1969) can be referred to. Examples of the acrylic resin of the present invention include polymethyl methacrylate and styrene- (meth) acrylate copolymer.

Examples of the polyester resin of the present invention include poly (ethylene terephthalate) (PET), poly (propylene terephthalate), poly (butylene terephthalate (PBT), poly (pentamethylene terephthalate), and poly (hexamethylene terephthalate). The so-called polyarylate resin, which is a polyester resin obtained from an aromatic dicarboxylic acid and a dihydric alcohol, and an aromatic polyester resin obtained from an aromatic dicarboxylic acid and an aromatic diphenol. Specific examples of the polyester resin include a polyester resin and a copolyester resin of bisphenol A and terephthalic acid or isophthalic acid. Copolymer of luic acid (T) and trimethylhexamethylenediamine (TMD), copolymer of isophthalic acid (I) and laurolactam (LL), isophoronediamine (IA) and bis (4-aminocyclohexyl) methane (PACM) )) And the like.
Heat of crystal fusion of amorphous polyamide resin (DSC measurement)
Is preferably less than 1 cal / g polymer.

The thermoplastic resin (B) having a glass transition temperature of 0 ° C. or higher in the present invention is preferably a styrene resin or an amorphous polyamide resin, and when these resins are used, the object of the present invention is further improved. Is obtained. The glass transition point of the thermoplastic resin (B) of the present invention is 0 ° C. or higher, preferably 5 ° C. or higher, and more preferably 20 to 350 ° C. When the glass transition point is lower than 0 ° C., the molded article of the present invention has poor vibration damping properties. The glass transition point of the thermoplastic resin (B) in the present invention is determined by the differential scanning calorimeter (D
It was measured under the following conditions using CS). (Conditions) Heating rate: 20 ° C / min, Atmosphere: Nitrogen, Sample amount: 20mg

The filler (D) of the present invention includes organic fillers and indefinite fillers, and known fillers can be used. Examples of the organic filler include polymer particles, and the polymer particles may be crosslinked or hollow. As the inorganic filler, for example,
Oxides such as iron oxide, alumina, magnesia, and zinc oxide; metal powders such as nickel, zinc, copper, and tungsten;
Silicates such as talc, mica and wollastonite, sulfates such as calcium sulfate and barium sulfate, titanates such as potassium titanate and barium titanate, ferrite, graphite, lac, calcium carbonate, glass beads, glass flakes , Glass fiber, carbon fiber and the like. Organic fillers are preferred when weight reduction is important, while inorganic fillers are preferred when vibration damping is also important.

The resin (C) of the present invention comprises the component (A) and the component (B)
And the composition range of component (A) is 25-9.
8% by weight, preferably 25 to 95% by weight, more preferably 30 to 85% by weight, and the component (B) is 75 to 2% by weight, preferably 5 to 75% by weight, more preferably 1 to 75% by weight.
5 to 70% by weight. Here, if the amount of the component (A) is less than 25% by weight, the mechanical properties deteriorate, and if the amount of the component (A) exceeds 98% by weight, the vibration damping property decreases. The amount of the component (D) is 5 to 250 parts by weight, preferably 110 to 200 parts by weight, and more preferably 15 to 150 parts by weight, per 100 parts by weight of the resin (C). (D) The amount of the component is 5
If the amount is less than parts by weight, sufficient vibration damping and sound insulation cannot be obtained,
On the other hand, when the amount exceeds 250 parts by weight, the formability and impact resistance decrease. Further, for the damping resin composition of the present invention,
Other components, for example, pigments, dyes, heat-resistant agents, antioxidants, weathering agents, lubricants, crystal nucleating agents, antistatic agents, plasticizers, and other polymers are added and introduced without impairing the object of the present invention. Then you can.

[0015] The molded article of the present invention is characterized in that:
It is obtained by hollow molding the vibration damping resin composition comprising (B) and (D). The hollow molding is a molding method called gas injection molding, and is a method in which a gas such as nitrogen gas is forcibly injected into a thick portion of a molded product to perform molding. For details, see Industrial Materials, February 1992, 53
The molding temperature is usually 200
About 400 ° C. The hollow ratio of a molded article molded by this molding method is preferably 5 to 50%, more preferably 10 to 45%, and particularly preferably 15 to 40%. By molding by this molding method, a molded article excellent in both weight reduction and molded appearance can be obtained. In addition, the vibration-damping resin composition of the present invention is a material suitable for hollow molding, and by using this material, the molding temperature range is wide, and therefore, the desired performance of the present invention is stably obtained, and A molded article having excellent molding appearance can be obtained. The molded article of the present invention is suitably used for automobile underhood parts. Automotive underhood parts include, for example, cooling fans, radiator tanks, cylinder head covers, oil pans,
Examples include gears, valves, and other parts of exhaust gas systems.

[0016]

The present invention will be described more specifically with reference to the following examples. In the examples, the part indicating the ratio is based on weight. In the following, the glass transition point is indicated as Tg. A method for measuring various physical properties in the examples will be described. Hollowness ratio: [(mold volume-volume excluding hollow portion of molded article) / (mold volume)] × 100 <unit%> Loss coefficient: Using a test piece having a thickness of 2 mm, a length of 220 mm, and a width of 10 mm. It was measured by an attenuation method. Tensile strength: ASTM D-790 Izod impact strength: ASTM D-256

Examples 1 to 5 Copolymer (a) (Tg2) of 55 parts of nylon-6 (8202C, manufactured by Allied) and n-butyl acrylate-methyl methacrylate-styrene (composition 35/50/15%)
15 parts of styrene-maleimide (composition 55/45)
%) Of copolymer (b) (Tg 204 ° C.) in 30 parts of resin, 2 parts of maleic anhydride, 0.1 part of peroxide (dicumyl peroxide), and a filler shown in Table 1 were added to Henschel. Mix with a mixer and mix it at 50m / m
Pellets were prepared using an extruder (cylinder temperature 250 ° C.). After vacuum drying the pellets, a box-shaped cylinder head cover (450 ° C.) was used at a resin temperature of 280 ° C. and a mold temperature of 70 ° C. by an injection molding machine equipped with hollow molding equipment.
× 200 × 80 mm, thickness 3.2 mm). A test piece was cut from the molded product, and the physical properties were measured.

[0018]

[Table 1]

Comparative Examples 1 to 5 The same procedures as in the Examples were carried out except for using the components shown in Table 1. Examples 6 to 10 and Comparative Examples 6 to 8 Nylon 4, 6 was used as the component (A) of the present invention.
(B) As a component, amorphous nylon (Grivory 3038, Tg 142 ° C, manufactured by EMS) was used, and the components shown in Table 2 were mixed with a Henschel mixer to prepare a test piece under the conditions shown in Example 1. Then, the physical properties were measured.

[0020]

[Table 2] Comparative Examples 1 and 6 are examples in which the amount of the component (B) used is less than the range of the present invention, and has a low loss coefficient value and poor vibration damping properties. Comparative Examples 3 and 8 are examples in which the Tg of the component (B) is less than the range of the present invention, and the vibration damping properties are poor. Comparative Examples 4 and 7 are examples in which the amount of the filler is less than the range of the present invention, and the vibration damping properties are inferior. Comparative Example 2 is (B)
This is an example in which the component exceeds the range of the present invention, and the tensile strength and impact resistance are poor. Comparative Example 5 is an example in which the amount of the filler exceeds the range of the present invention, and is inferior in vibration damping property and impact resistance.

[0021]

According to the present invention, the molded article of the present invention has a vibration damping property, mechanical strength,
Since it is excellent in moldability and heat resistance and is lightweight, it can be suitably used particularly for automobile underhood parts.

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁷ Identification symbol FI // B29K 77:00 B29L 22:00 31:30 (56) References JP-A-5-38746 (JP, A) JP-A 5-302028 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 45/00 B29C 49/00 C08K 3/00 C08K 5/00 C08L 77/00

Claims (3)

(57) [Claims] 1. A resin comprising 25 to 98% by weight of a polyamide resin (A) and 75 to 2% by weight of a thermoplastic resin (B) having a glass transition point of 0 ° C. or higher (excluding (A)). (C) 5 to 50% of a resin composition obtained by hollow molding a resin composition obtained by mixing 2 to 250 parts by weight of a filler (D) with 100 parts by weight.
A molded body having a void ratio . 2. A resin comprising 25 to 98% by weight of a polyamide resin (A) and 75 to 2% by weight of a thermoplastic resin (B) having a glass transition point of 0 ° C. or higher (excluding (A)). (C) A molded product obtained by subjecting a resin composition obtained by mixing 2 to 250 parts by weight of a filler (D) to 100 parts by weight to gas injection molding . 3. An underhood component for an automobile, comprising the molded product according to claim 1.