JPH0453871A - Automobile underhood component - Google Patents

Abstract

PURPOSE:To obtain a composition desirable for an automobile underhood component having a good resistance to a road anti-freezer and excellent rigidity and heat resistance, etc., by mixing a specified copolyamide with a filler. CONSTITUTION:This automobile underhood component is formed by molding a composition prepared by mixing 100 pts.wt. polyamide resin comprising recurring units (I) of formula I [hexamethylenetererhthalamide units] and any one of repeating units selected from among recurring units (II) of formula II [hexamethyleneisophthalamide units], recurring units (III) of formula III [hexamethyleneadipamide units] and recurring units (IV) of formula IV [capramide units] and having a copolymerization ratio of I/II or 55/45-100/0 or I/III or 20/80-99/1 or I/IV or 55/45-99/1 with 0-200 pts.wt. filler.

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention has good resistance to road surface antifreeze agents whose main ingredients are metal halide compounds such as cal/lam chloride, magne/lam chloride, and zinc chloride, and has excellent M properties and heat resistance. The present invention relates to underhood parts for automobiles made of polyamide. <Conventional Technology> In recent years, there has been a noticeable trend in the automobile industry to replace conventional metal parts with resin for the purpose of reducing weight to improve fuel efficiency, rust prevention, and sound insulation. Among them, polyamide resin has excellent heat resistance, oil resistance, colorability, and toughness, so it is used in underhood parts of automobiles, such as cooling fans, radiator tank tops and bases, and cylinders. It is being applied to various functional parts such as oil pans, gears, valves, brake piping, fuel piping tubes, other exhaust gas system parts, and electrical system parts such as connectors. Generally, antifreeze agents containing calcium chloride, magne/lamb chloride, zinc chloride, etc. as main ingredients are sprayed on roads in cold regions, especially in winter, to prevent road surfaces from freezing. There is a need for materials with high resistance to On the other hand, nylon 6, nylon 66 and nylon 1
Polyamide resin compositions blended with nylon 1 and nylon 12 and their reinforced products (JP-A-608-8066, JP-A-57
-212252, etc.), polyamide resin compositions blended with aliphatic polyamide and aromatic polyamide, and reinforced products thereof (JP-A-58-120665, JP-A-58-53)
950, etc.), resin compositions made by blending polyamide with phenol resin or modified polyolefin, and reinforced products thereof (JP-A-60-188456, JP-A-61-76540)
), and many others have been proposed. <Problems to be Solved by the Invention> With the rise in temperature in automobile engine compartments due to recent technological innovations and the progress of microelectronics, there has been a demand for molded article materials that can sufficiently withstand use in even higher temperature atmospheres. However, these resin compositions lack the mechanical properties such as tensile strength and flexural modulus as well as heat resistance as metal substitute materials, and their material costs are high, so they can only be used in extremely limited applications. . Means for Solving the Problems> In view of the above circumstances, the present inventors have developed a material that has high rigidity and high heat distortion temperature that can withstand use in high-temperature atmospheres, is inexpensive, and is resistant to road antifreeze agents. As a result of studying underhood parts for motor vehicles that satisfy the required characteristics, it was discovered that a specific terephthalic acid-containing polyamide resin composition could solve all the problems, and the present invention was achieved. That is, the present invention relates to a hexamethylene terephthalamide unit represented by a repeating unit and any unit selected from repeating units (II) to (■), an amide unit, a hexamethylene adipamide unit represented by (rV) -Nll-(CL)i-C-, and the copolymerization ratio is (+)/(■)=55 by weight.
745-10010 or (1)/(III)-2
0/80~99/l or (1)/(rV)~55
Polyamide resin (A) 1 in the range of /45 to 99/l
0 to 20011 parts by weight of filler CB)
This is an automobile underhood part made by molding a compound containing the following. The polyamide resin (A) of the present invention is any one selected from (1) hexamethylene ethylene phthalamide units, (It) hexamethylene isophthalamide units, (■) hexamethylene upamide units, and (rV) caproamide units. It is a copolymerized polyamide formed from the following units, (
1)/(II) copolymerization ratio is 55/45-1 by weight
0010 (hereinafter referred to as 6T/61 fubolyamide) or (■)/(m) copolymerization ratio is 20/80 by weight
~99/l (hereinafter referred to as 6T/66 copolyamide) or a copolymerization ratio of (1)/(IV) of 55% by weight
/45 to 99/1 (hereinafter referred to as 6T/6 cobolyamide). According to the present invention, the common fia ratio of 6T/61 is 55/4
5~lo olo, preferably 60/40~90/10
．． more preferred

[, < must be in the range of 60/40-80/20. Also, the ratio of 6T/66 is 20/80 to 99/L, preferably 3B/65
~80/20, more preferably 4o/60~60/4
It must be in the range of 0. Further, the copolymerization ratio of 6T/6 is 55/45 to 997'l, preferably 6
0/40-85/15, preferably 60/40-8
It is necessary to be in the range of 0/20. 6 here
T/6L 6T/66 and 6T/6 copolyamide copolyamide with specific gravity content and lima melting point of approximately 270°C or higher. 6T/61.6T/
The copolymerization ratio of 66 and 6T/6 is 55/45, respectively.
．． If it is less than 10/90 or 55/45, the melting point of the polymer will be lowered, and heat resistance such as thermal shadow temperature will be lowered, which is not preferable. There is no particular restriction on the degree of polymerization of the polyamide used here, and it is usually a 1% sulfuric acid solution at 25°C.
Any material having a relative viscosity (ηr) of 1.5 to 50 can be used. Although the method for producing the polyamide 4IlK ¥1 of the present invention is not particularly limited, the terephthalic acid-containing copolyamide resin composition of the present invention has a higher melt viscosity as the amount of terephthalic acid component units increases, and the melt viscosity becomes higher than that of the usual melt weight. (
1) ~ (rV) I An aqueous solution of a mono-7- or salt of an acid component is stirred at a water vapor pressure of 20 kg/cm2-G or less, +5
Heating at 0-320°C, ηr=1. 01-1. Simple methods include producing a low-order condensate of 6 and then solid-phase polymerizing it at a temperature below the melting point, or using a single-screw or twin-screw extruder with a vent to achieve a high degree of polymerization. . According to the present invention, the presence of a phosphorus catalyst is effective in obtaining pellets with a good degree of polymerization in the melt extrusion process, and the amount added is preferably 0.02 to 2 wt% based on the lower condensate. , more preferably 0.05 to 1.2 wt%. 9
Specific examples of carbon-based compounds include H3PO4 and B3P.
03, H3P02, l14P20, NaH2PO4-
2H20+Na2BPOa・12HeO1NaaP04
12H20, Na112POa・HaO1Na4P20
710B20, Na2HiPsOv ・6HzO1Na
6PaO+@, CaHsP (DH>2, Cs1ls
PO(ONa)2, C5HsPO(OH)2,
Examples include Mn(H2PO4)2 and (Ca8%0)3P. Preferably HsPOa, 1IaF'2
It is 0v. There are no particular restrictions on the method of adding the phosphorus compound, and methods such as when preparing a low-order condensate, or a method in which it is blended in advance with a low-order condensate and melt-extruded are simple and suitable. The filler (B) as used in the present invention refers to glass fibers or beads, talc, kaolin, wollastonite, mica 1, lyca, alumina, diatomaceous earth, clay, sebukou, penogara, graphite, titanium dioxide, oxidized Examples include powdery or plate-like inorganic compounds such as zinc, copper, and stainless steel, and other dimmer fibers (carbon fibers), and preferably glass fibers. Particularly preferred glass fibers are glass tyrobuton strands, glass threads, etc. having a diameter of about 3 to 20 μm. The blending ratio of such a filler needs to be in the range of 0 to 200i 1 part based on the polyamide + ooffi placement part, preferably in the range of more than 0 to 150i 1 part, and particularly preferably in the range of 10 to 1 part
00 parts by weight. If the blending ratio of the filler exceeds 200 parts by weight, the fluidity during melting will deteriorate, making it difficult to injection mold the molded product, and the appearance of the molded product will also deteriorate, which is not preferable. There is no particular restriction on the method of blending the filler into the polyamide of the present invention, and any known method can be used. As a specific example of the blending method, polyamide IMT
Examples include a method in which a filler is dry-pre-drilled into a No. # pellet and then melt-kneaded using a single-screw or two-wheel screw extruder. The underhood parts for automobiles of the present invention are molded by subjecting the polyamide compound to known molding methods such as injection molding, extrusion molding, blow molding, and vacuum forming. Examples of molded products include cooling fans, radiator tacks, printer head covers, oil pans, gears, valves, brakes, fuel piping, other tubes, vibrators, other exhaust gas system parts, and connectors. In addition, the molded parts obtained in this way are coated, vapor-deposited,
Secondary processing such as lamination can also be performed. In addition, the automotive underhood parts of the present invention may contain other ingredients such as pigments, dyes L1, heat resistant agents, catalysts,
Antioxidants, weathering agents, lubricants, crystal nucleus side, antistatic agents, phobic agents, other polymers, etc. can be added. <Example> The present invention will be explained in more detail with reference to Examples below. In addition, various properties in Examples and Comparative Examples were measured by the following methods. l) Melting point (Tm) The temperature showing the maximum value of the melting curve obtained by measuring 8 to 10 mg of sample at a heating rate of 20°C/ml using DSC (PER IN-ELMER 7 type) is defined as (Tm). ). Sample 8~l Omg R temperature rate 0℃/'m
Heat at T4-20°C for 5 minutes 17, then
Cool down to 30℃ at a cooling rate of 20℃/m I n [7
．． After holding at 30 °C for 5 min, return to 20 °C/m I
Heat to T+20° C. at a heating rate of n. The maximum value of the melting curve at this time was defined as the melting point (Tm). 2) Metal halide resistance test After immersing the underhood molded product in 90°C warm water for 24 hours, it was placed in a gear oven at 100°C! Then, the number of cycles until cracks appeared in the molded product was measured, with one cycle of spraying 50% 0% calcium chloride/rum water droplets every hour. 3> Appearance of molded product The surface roughness, air bubbles, color tone, gloss, etc. of the molded product were observed. O: The surface is glossy and smooth. △: The gloss is reduced, but the surface is smooth. ×: The surface is rough and has no luster. 4) Physical properties of the molded product were measured by the following method. Tensile strength/ASTM-D638 bending strength: ASTM-D790 bending modulus
: ASTM-D790I zod impact strength
: ASTM-D256 heat distortion temperature (HpT):
ASTM-D648 load 4.6 kgf/c++' Load 18.6 kgf/e++2 <Example 1> 1117.21 kg of terephthal, 7.80 kg of a 64.5 wt% aqueous solution of hexamethyldiamine. 5.25 kg of caprolactam and 6.1 kg of ion exchange water
Charge 0 kg into a 0.05 m' batch type pressure polymerization pot,
After sufficient nitrogen substitution, the water vapor pressure was 17.5 kg/
Heating was continued under pressure of am''-G. After raising the temperature to 230°C over 5 hours with stirring, the reaction was further allowed to proceed for 30ml at 230°C to 245°C, then stirring was stopped and the temperature was increased from the bottom of the polymerization vessel. The lower condensate was extracted into water at a differential pressure of 17.5 kg/em''G. The obtained low-order condensate has a temperature of Tm-303°C,
ηr=1.21. This low-order condensate was heated to 100°C.
After vacuum drying for 24 hours, solid-phase polymerization was performed at a temperature of 250° C. for 3 hours in a N2 blowing atmosphere using a kneader with an internal volume of 301 kg. The obtained polymer has ηr-2.75
, Tm=303°C. After tri-blending 65 parts by weight of glass fiber strands with a length of 3 mm and a blade diameter of 13 μΦ to 100 parts by weight of this polymer, Tm was added using a 30 mmΦ single screw extruder.
The mixture was melt-kneaded and pelletized at a temperature of +20°C. After drying this pellet in vacuum, it was molded into an ASTM standard physical property test piece and a length of 450 mm using an injection molding machine under the conditions of a Linder temperature T'm + 20°C and a mold temperature of 80°C.
[200mm, height 80mm, wall thickness 3.5mm
A fI alliance cylinder rad cover was molded. Using the molded piece obtained here, mechanical properties, heat distortion temperature,
Table 1 shows the results of evaluating resistance to metal halides. <Execution 4!112> Terephthalic acid 5□ 89 kg, hexamethylene di7mi7 64. 5wt% water 111i [13,37k
g, -, No. K methylene ammonium adipate) (66 salt) 10.00 kg and ion exchange water 5.66 kg
．． A low-order condensate was prepared in the same manner as in Example 1. The obtained low-order condensate had Tm = 296°C, +7r = 1.26. After vacuum drying this low-order condensate at 100°C for 24 hours, 3
Melt extrusion was performed using a 0 mmφ vented twin screw extruder to obtain pellets with ηr-3°25 and Tm=295°C. A molded article was made using this pellet by the method of Example IFIII, and the results of evaluation are shown in Table 1. <Example 3 ~ IQ> By changing the type of polyamide, type of filler, blending amount, etc.
Table 1 shows the results of evaluating the characteristics of test pieces and molded products obtained by performing the same operations as in the actual mF12.
It was shown to. Compare 41111> Glass fiber reinforced nylon 66 (CM3001G30/
Test covers were prepared in the same manner as in Example 1 using Toshiba product). The chloride resistance of this molded product was a blessing. <Comparative Example 2> A test piece and an underhood part were prepared by triblending 651,111 parts of glass fiber chinabuto strands with 1 part of nylon 12, 1ooii, and performing the same procedure as in Example. When the physical properties of the obtained test piece were evaluated, it was found that the rigidity and heat distortion temperature were insufficient. <Effects of the Invention> Automobile a/da foot parts of the present invention (high rigidity and heat deformation temperature, and metals such as chloride and zinc chloride) - Good resistance to road surface antifreeze agents containing rogen compounds as main ingredients Therefore, it is suitable as a material for automobile underhood parts.

Claims (1)

[Claims] Repeating unit (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ Hexamethylene terephthalamide unit and any unit selected from repeating units (III) to (IV), (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ Hexamethylene isophthalamide units represented by (III) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ Hexamethylene adipamide units represented by (IV) There are tables, etc. ▼ Consisting of caproamide units represented by
I)=20/80~99/1 or (I)/(IV)=5
Polyamide resin in the range of 5/45 to 99/1 [A]
0 to 200 parts by weight of filler [B] per 100 parts by weight
Automotive underhood parts made by molding a compound containing