JPH10139892A - Resin molding part for cooling system of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin molding part for cooling system of an internal combustion engine, molded by resin molding material having a lighter weight and smaller moisture adsorption compared to the conventionally used polyamide resin, etc., including glass fiber; and further having superior antifreeze resistance, high temperature strength properties, moldability, etc. SOLUTION: This resin molding part for cooling system of an internal combustion engine is obtained by impregnating a polypropylene-based resin into a bunch of glass filaments to form a composition comprising 60-90 pts.wt. polypropylene-based resin, 40-10 pts.wt. glass fiber, 0.1-5 pts.wt. antioxidant and 0.01-2 pts.wt. carbon black, and thermoforming the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molded part for a cooling water system of an internal combustion engine, and more particularly to a molded article obtained by molding a pellet obtained by impregnating a long glass fiber with a polypropylene resin to obtain an excellent mechanical strength. The present invention relates to a resin molded part for a cooling water system of an internal combustion engine, such as a radiator tank part having the same.

[0002]

2. Description of the Related Art Polyamide reinforced with glass fibers has been widely used as a molding material for components of an internal combustion engine cooling water system such as a radiator tank. However, the specific gravity is large and the whole molded article is heavy. Physical properties due to moisture absorption are unavoidable. Solvent resistance (antifreeze) is insufficient. Calcium chloride resistance is poor. Some have been made.

Further, a radiator tank (JP-A-58-21445) molded using a resin composition comprising a polyamide, a modified polypropylene and a fibrous reinforcing agent,
An automotive radiator tank-forming resin composition comprising glass fibers bundled with an acrylic resin in a polyolefin (Japanese Patent Laid-Open No. 62-241940), an engine molded from a polypropylene resin containing glass fibers having an aspect ratio of 100 or more. Cooling water system parts (Japanese Unexamined Patent Publication
No. 41565) has also been proposed.

Among these proposals, Japanese Patent Application Laid-Open No. 7-415
No. 65 discloses an engine cooling water system component formed of a polypropylene resin containing glass fiber having an aspect ratio of 100 or more. The present invention focuses on the resin composition of a resin material for molding. is there. However, in general, when molding such a resin containing glass fiber, the glass fiber is usually crushed in the molding process to become shorter glass fiber.

[0005] Therefore, even when these proposed glass fiber-filled polypropylenes are used in place of the glass fiber-containing polyamide resin, creep at high temperature, strength at high temperature, vibration fatigue properties at high temperature, long term under high temperature It is still insufficient in terms of thermal stability.

[0006]

DISCLOSURE OF THE INVENTION The present invention is an improvement over a conventionally used polyamide resin containing glass fiber, which is lightweight, does not absorb moisture, has excellent antifreeze resistance, high-temperature strength properties, moldability, etc. To provide a resin molded part for an internal combustion engine cooling water system molded using a novel resin molding material.

[0007]

Means for Solving the Problems As a result of intensive studies on the above-mentioned problems, the present inventors have completed the present invention having the following contents. (1) Average fiber length 1 to 6 mm in polypropylene resin
Resin molded parts for internal combustion engine cooling water system in which glass fibers are dispersed. (2) Average fiber length 1 to 6 mm in polypropylene resin
An internal combustion engine cooling water system resin molded part in which the above glass fiber and antioxidant are dispersed. (3) After impregnating a bundle of long glass fibers with a polypropylene resin, an antioxidant is added to 60 to 90 parts by weight of the polypropylene resin, 40 to 10 parts by weight of glass fiber, and 100 parts by weight of the former two in total. A resin-molded part for an internal combustion engine cooling water system obtained by thermoforming a blend comprising 1 to 5 parts by weight and 0.01 to 2 parts by weight of carbon black. (4) The resin molded part for an internal combustion engine cooling water system according to any one of the above (1) to (3), wherein the polypropylene resin is an acid-modified polypropylene alone or a polypropylene containing an acid-modified polypropylene. (5) The internal combustion engine cooling as described in (2) or (3) above, wherein two or three selected from phenolic antioxidants, phosphorus antioxidants and sulfur antioxidants are used as antioxidants. Water system resin molded parts. (6) The internal combustion engine cooling water system resin molded part according to any one of (1) to (5), wherein the internal combustion engine cooling water system resin molded part is a resin molded upper portion or a lower portion of a radiator tank.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. (1) Molding material A material called “continuous structure” in which a bundle of long glass fibers is impregnated with a polypropylene resin is used. As the polypropylene resin used here, an acid-modified polypropylene having excellent adhesion to the glass fiber surface can be suitably used. For example, maleic acid-modified polypropylene,
Acrylic acid-modified polypropylene, fumaric acid-modified polypropylene and the like can be mentioned. Although these acid-modified polypropylenes alone are more preferable, homopolypropylene, an ethylene-propylene random copolymer, an ethylene-propylene block copolymer, an ethylene-propylene-butene-ternary copolymer, and the like may be mixed. . Further, those obtained by subjecting a glass fiber surface to a corona discharge treatment, a silane coupling treatment, or the like are also suitably used.

This continuous structure is usually 2 to 100 m
m, preferably 5 to 50 mm, more preferably 6 to 20
The pellets cut into mm are used. Furthermore,
A masterbatch prepared by dispersing carbon black and an antioxidant in homopolypropylene and the above-mentioned polypropylene resin is prepared, and is blended with pellets obtained by impregnating the glass filaments with polypropylene to prepare a molding material.

Various types of carbon black can be used. Examples of the carbon black include furnace black, lamp black, thermal black, acetylene black, and furnace black, such as carbon black and channel black having a finer particle size. , Rollers and disc blacks, and carbon blacks produced by an impact method such as German naphthalene black. Among these, acetylene black is particularly effective in improving the high-temperature durability and can be suitably used.

As the antioxidant, various types of antioxidants such as a phenolic antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant can be used in combination of two or three kinds.
It is suitable for suppressing deterioration of the physical properties of the resin at high temperatures.
These antioxidants include, for example, 2,6-di-t-butyl-p-cresol [BH
T], 2,2'-methylenebis (4-methyl-6-t-
Butylphenol), 4,4′-thiobis (3-methyl-6-t-butylphenol), 4,4′-butylidenebis (3-methyl-6-t-butylphenol), stearyl-β (3,5-di-4 -Butyl-4-hydroxyphenyl) propionate [Irganox 107
6], 1,1,3-tris (2-methyl-4hydroxy-5-t-butylphenyl) butane <Topanol C
A>, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl)
Benzene [Ionox 330], tetrakis {methylene-3 (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate} methane [Irganox
1010] and the like.

Examples of the phosphorus-based antioxidant include tri (nonylphenyl) phosphite, 2-ethylhexiphenyl phosphite, trimethyl phosphite, triethyl phosphite, tributyl phosphite, trioctyl phosphite, and trinonyl phosphite. Phytite, tridecyl phosphite, trioctadecyl phosphite, distearyl pentaerythryl diphosphite, tris (2-
Trialkylphosphites such as chloroethyl) phosphite and tris (2,3-dichloropropyl) phosphite; tricycloalkylphosphites such as tricyclohexylphosphite; triphenylphosphite;
Tricresyl phosphite, tris (ethylphenyl)
Triaryl phosphites such as phosphite, tris (butylphenyl) phosphite, tris (nonylphenyl) phosphite and tris (hydroxyphenyl) phosphite; trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tridecyl phosphate, Trialkyl phosphates such as trioctadecyl phosphate, distearyl pentaerythrityl diphosphate, tris (2-chloroethyl) phosphate and tris (2,3-dichloropropyl) phosphate; tricycloalkyl phosphates such as tricyclohexyl phosphate;
And triaryl phosphates such as triphenyl phosphate, tricresyl phosphate, tris (nonylphenyl) phosphate, and 2-ethylphenyl diphenyl phosphate.

As the sulfur-based antioxidants, dilauryl thiodipropionate [DLTP], dimyristyl thiodipropionate [DMTP], lauryl stearyl thiodipropionate [LSTP], distearyl thiodipropionate [DSTP] And the like. In the molding material thus adjusted, usually, 60 to 90 parts by weight of a polypropylene resin, 10 to 40 parts by weight of a long glass fiber,
A mixture of carbon black 0.01 to 2 parts by weight and antioxidant 0.1 to 5 parts by weight with respect to the total of 100 parts by weight of the former two is used. 80 parts by weight, long glass fiber 20-35
What is blended in a ratio of 0.01 to 1 part by weight of carbon black and 0.3 to 4 parts by weight of an antioxidant is preferable.
If the amount of long glass fiber is less than 10 parts by weight, the strength is insufficient, and if it exceeds 40 parts by weight, the appearance is deteriorated. If the amount of carbon black is less than 0.01 part by weight, coloring becomes insufficient, and if it exceeds 1 part by weight, heat resistance becomes insufficient.

If the amount of the antioxidant is less than 0.1 part by weight, the long-term heat stability may be insufficient, and if it exceeds 5 parts by weight, the effect of increasing the amount cannot be expected. This long glass fiber reinforced polypropylene molding material has no hygroscopicity,
No drying is required before molding the resin. In order to prevent the glass fibers from being broken, a simple stirring method such as tumbler blending is usually employed for the method of adjusting the blending of the glass long fiber reinforced polypropylene molding material. The molding material may contain known additives such as a plasticizer, a pigment, an active agent, a release agent, a stabilizer, and an inorganic filler as long as the resin properties of the present invention are not impaired.

(2) Cooling Water System Resin Molding Section for Internal Combustion Engine
Cooling water system of goods internal combustion engine, the heat of the heating the engine by circulating coolant composed mainly of water or ethylene glycol, responsible for the heat radiation by the radiator, a resin molded component used in this strain, The main components are a water pump housing, a radiator tank (upper part and lower part), a tank attachment and the like.

[0016] These internal-combustion engine cooling water system resin molded parts have a maximum circulating water temperature of 100 to 105 ° C and a temperature of 0.5 to 0.
In addition to reaching 7 kg / cm ² , it is a resin material that withstands temperature and vibration in the engine room.
It is required that the heat-resistant deterioration time at ℃ is 500 hours or more, preferably 1000 hours or more, more preferably 1500 hours or more. A thermoformed part, such as injection molding, press molding, or profile extrusion molding, made of the long glass fiber reinforced polypropylene-based molding material is a molded article of the present invention having physical properties to withstand this.

The glass fiber is crushed in the thermoforming step also in the glass long fiber reinforced polypropylene molding material.
Due to its small extent, analysis of the resulting molded part reveals an average fiber length of 1-6 mm, preferably 1.5-1.5 mm.
-6 mm, more preferably 2.0-6 mm glass fibers are dispersed. The measuring method is as follows. A 50 g sample piece cut out from an injection molded test piece is heated at 550 ° C. in an electric furnace.
Bake and incinerate for 2 hours. Only the glass fiber remaining in the ash is taken out, dispersed on a glass plate, photographed with a universal projector at a magnification of 20 times, and the fiber length is measured with a digitizer.

[0018]

EXAMPLES The present invention will be described in more detail with reference to Production Examples, Examples and Comparative Examples. Example 1 A bundle of long glass fibers was impregnated with maleic acid-modified polypropylene and cut to a cut length of 12 mm. 50% by weight of a pellet (A) containing 60% by weight of glass fiber, 1% by weight of acetylene black (carbon black), and phenol-based Pellets (B) 50 obtained by kneading 3% by weight of an antioxidant, 1% by weight of a sulfur-based antioxidant, and 95% by weight of polypropylene.
The weight parts were mixed by a tumbler and injection molded to form a radiator tank top part (1a in FIGS. 1 and 2). From the obtained product and the test piece cut out from the product, specific gravity,
Antifreeze resistance, moisture resistance, high-temperature tensile strength, high-temperature creep properties, long-term heat resistance, product warpage, product impact strength, product internal pressure test, glass fiber in the product (hereinafter referred to as “GF”)
Was evaluated for the average fiber length. Table 1 shows the results.

The method of each test is as follows. Antifreeze resistance: A test piece cut out was immersed in an antifreeze of 50% concentration for 500 hours, then taken out and JIS K-7203.
Perform bending test in accordance with. Moisture resistance test: After standing at 23 ° C. and 50% humidity for 48 hours, a bending test is performed in accordance with JIS K-7203. High temperature tensile strength: based on JIS K-7113. High temperature creep characteristics: 100 kg in an atmosphere of 120 ° C.
/ Cm ² , and the amount of strain after 100 hours is measured. Long-term heat resistance: Put into a 160 ° gear oven, and visually determine deterioration. Product warpage: One side of the product is fixed, and the floating amount on the other side is measured with a height gauge. Product impact strength: The height at which a ball having a weight of 1 kg is dropped on a product surface and broken is obtained. Product internal pressure test: The product is incorporated in a radiator, water is added, the product is left at an internal pressure of 5 kg for one week, and the situation is visually determined. Average fiber length of GF in the product: A 50 g sample piece cut out from an injection molded test piece is baked in an electric furnace at 550 ° C. for 2 hours and incinerated. Only the glass fibers remaining in the ash are taken out, dispersed on a glass plate, photographed with a universal projector at a magnification of 20 times, and the fiber length is measured with a digitizer.

COMPARATIVE EXAMPLE 1 6-Containing 33% by weight of short glass fiber having a length of 0.3 mm
The radiator tank top was injection-molded using 6-nylon and the mold used in Example 1.
The evaluation was performed using the obtained product and a test piece cut out from the product. Table 1 shows the results.

Comparative Example 2 68% by weight of homopolypropylene, 0.5% by weight of oil furnace carbon black, 1.5% by weight of a phenolic antioxidant, and 0.5% by weight of a sulfur-based antioxidant were previously mixed by a tumbler. After that, the mixture was put into a hopper of a twin-screw kneader, and supplied to a cylinder portion of the kneader through a hopper opening. On the other hand, 30% by weight of short glass fiber having a length of 3 mm was quantitatively supplied from the side feed port of the twin-screw kneader and kneaded to obtain a pellet. Using the pellets, the radiator tank top portion was injection molded using the mold used in Example 1 to produce the radiator tank. The evaluation was performed using the obtained product and a test piece cut out from the product. Table 1 shows the results.

Example 2 A bundle of long glass fibers was impregnated with maleic acid-modified polypropylene and cut to a cut length of 12 mm. 40% by weight of a pellet (A) containing 60% by weight of glass fibers and 0.5 of acetylene black (carbon black) were used. Wt%, phenolic antioxidant 2.5 wt%, sulfur antioxidant 1 wt%, phosphorus antioxidant 0.5 wt%, polypropylene 9
60 parts by weight of a pellet (B) obtained by kneading 5% by weight were mixed by a tumbler and injection molded to prepare a radiator tank bottom part (1b in FIGS. 1 and 2). Evaluation was made from the obtained product and test pieces cut out from the product. Table 1 shows the results.

[0023]

[Table 1]

[0024]

As can be understood from the above Examples and Comparative Examples, the molded parts of the present invention have an antifreeze liquid resistance and a moisture resistance because the average length of the glass fiber in the product is kept within a certain range. The basic mechanical strength as a member such as heat resistance and high temperature properties (tensile, creep, long-term heat deterioration), excellent in chemical resistance, and even in actual use tests of products incorporated as a radiator tank II Excellent in internal pressure test and product impact strength.

[Brief description of the drawings]

FIG. 1 is an exploded view of a radiator as an example of the present invention.

[Explanation of symbols]

 1a: Radiator tank top 2: Radiator core 3: Antifreeze / air exchanger 1b: Radiator tank bottom

Claims (6)

[Claims] An average fiber length of 1 to 1 in a polypropylene resin.
Internal-combustion engine cooling water system resin molded part in which 6 mm glass fiber is dispersed. 2. An average fiber length of 1 to 2 in a polypropylene resin.
An internal combustion engine cooling water system resin molded part in which 6 mm glass fiber and an antioxidant are dispersed. 3. After impregnating a bundle of long glass fibers with a polypropylene resin, a total of 100 to 90 parts by weight of the polypropylene resin, 40 to 10 parts by weight of the glass fiber, and 100 parts by weight of the former are used.
A resin molded part for an internal combustion engine cooling water system, which is a compound comprising 0.1 to 5 parts by weight of an antioxidant and 0.01 to 2 parts by weight of carbon black with respect to parts by weight. 4. The resin molded part for an internal combustion engine cooling water system according to claim 1, wherein an acid-modified polypropylene alone or a polypropylene containing an acid-modified polypropylene is used as the polypropylene resin. 5. The internal combustion engine cooling according to claim 2, wherein two or three selected from phenol-based antioxidants, phosphorus-based antioxidants and sulfur-based antioxidants are used in combination as the antioxidant. Water system resin molded parts. 6. The resin molded part for an internal combustion engine cooling water system according to claim 1, wherein the resin molded part for an internal combustion engine cooling water system is a resin molded upper portion or a lower portion of a radiator tank.