JPH01313555A - Automobile junction block - Google Patents

Abstract

PURPOSE:To obtain an automobile junction block excellent in heat resistance, impact resistance and dimensional stability by mixing polypropylene with a specified polymer, a specified cooligomer and a polyamide in a specified ratio. CONSTITUTION:The title junction block is obtained by molding a polymer composition comprising (A) polypropylene, (B) a modified polymer obtained by introducing acid anhydride groups into polypropylene and/or a copolymer of a vinylaromatic compound with an olefin, (C) a liquid olefin oligomer containing an acid anhydride group or a cooligomer of a vinylaromatic compound with an olefin and (D) a polyamide, wherein a+b+c+d=100, 0<=b/(a+b)<=0.17, 0.01<=c<=10, and 10<=a+b<=50, wherein a, b, c and d are the amounts (wt.%) of the components A, B, C and D, respectively.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides an automotive junction with excellent heat resistance, impact resistance, dimensional stability, and excellent locking feeling when attaching a connector, which reduces attachment errors. It's about blocks.

(Conventional technology) Traditionally, electrical components such as fuse boxes and connectors were independent in automobiles, but as automobiles became more sophisticated, the number of electrical components increased, so space-saving and
The integration of parts has progressed from the perspective of labor saving, and junction blocks (also known as junction blocks) have integrated circuit connection functions and related parts such as relays, fuses, circuits, etc. Junction boxes, junction boxes, relay blocks) have come into use in recent years.

Polyamide and polypropylene are used as materials for this junction block.

In recent years, with the increase in engine output and the reduction in vehicle height, the temperature in the engine compartment has tended to rise, so it is desired that polypropylene junction blocks have improved heat resistance. On the other hand, the bending elastic modulus of polyamide junction blocks decreases due to water absorption, resulting in a loss of opening and closing feeling, which poses a major problem in that connectors may be incorrectly installed when assembling automobiles. Furthermore, from the standpoint of safety, improvement in impact resistance was also desired.

(Problems to be Solved by the Invention) An object of the present invention is to provide a junction block for an automobile that has excellent heat resistance, impact resistance, and dimensional stability, and has excellent locking feeling when a connector is attached, thereby reducing attachment errors. The purpose is to

(Means and Effects for Solving the Problems) The present inventors have arrived at the present invention as a result of intensive studies to solve the problems of the prior art.

That is, the present invention provides A: polypropylene, B: a modified polymer in which an acid anhydride group is introduced into a copolymer of polypropylene and/or a vinyl aromatic compound and an olefin, and C:
A composition comprising: a liquid olefin oligomer containing an acid anhydride group or a copolymer oligomer of a vinyl aromatic compound and an olefin; D: polyamide;
, B, C and D are a, b, c and 4% by weight, a+b+c+d=100 0≦b/(a+b)≦0.17 0.01≦C≦10 10≦a+b≦50 This invention relates to an automobile junction block made of a polyamide composition.

The polypropylene of component A in the present invention is not particularly limited, but preferably has a density of 0.89 to 0.93 g/c4.
．． VFR (ASTM 01238) 0.01~
30g/lQn+in, and is a propylene homopolymer or a so-called block copolymer or random copolymer of propylene and 20 mol% or less of ethylene, 1-butene, 4-methyl-1-pentene, etc. It is a mixture or combination of these.

The copolymer of vinyl aromatic compound and olefin referred to in the present invention will be explained. As a vinyl aromatic compound,
Examples include styrene, α-methylstyrene, vinyltoluene, etc., and examples of olefins include ethylene, propylene,
Examples include α-olefins such as butene-1, hentene-1, hexene-1,4-methylpentene-11octenylene-1, and the like. Also included are copolymers of the above-mentioned vinyl aromatic compounds and conjugated diene compounds such as butadiene, isoprene, and 1,3-pentadiene, particularly hydrogenated block copolymers. In this case, depending on the degree of hydrogenation, double bonds may remain to an extent that the degree of unsaturation does not exceed 20% by weight.

A modified polymer in which an acid anhydride group is introduced into the copolymer (α) of polypropylene and/or a vinyl aromatic compound and an olefin as component B is a modified polymer in which an acid anhydride group is introduced into the polymer shown in α, and maleic anhydride is added to the polymer shown in α. When the polymer shown in α is polymerized, an unsaturated acid anhydride such as maleic anhydride is copolymerized, or acrylic acid, fumaric acid, or maleic acid is added. There is a method in which an unsaturated carboxylic acid such as itaconic acid is copolymerized and then dehydrated to form an acid anhydride group. Preferred is a method of adding maleic anhydride or the like.

The liquid olefin oligomer containing an acid anhydride group, which is component C, and the copolymer oligomer of a vinyl aromatic compound and an olefin are extremely low-containing polyolefins and/or copolymers of a vinyl aromatic compound and an olefin. It is a molecular oligomer that is liquid at room temperature and contains an acid anhydride group by some means.

The polyolefin referred to in the present invention is a homopolymer or copolymer of α-olefin such as ethylene, propylene, butene-1, pentene-1, hexene-1,4-methylpentene-1, octenylene-1, or a polymer thereof. The copolymer may be either random or block. Specific examples include polyethylene,
Included are polypropylene, polybutene, polyoctenylene, ethylene, propylene copolymers, ethylene-butene copolymers and blends thereof. Small amounts of diene components such as ethylene propylene terpolymer may also be included.

Regarding the method of introducing acid anhydride groups, in addition to the method described for B, in the case of hydrogenated conjugated diene polymers, when living polymerization of the conjugated diene compound, ethylene oxide is added and the terminal is 10H group. It is also possible to take a certain polybutadiene, hydrogenate it, and then bond a compound having an acid anhydride group using the -OH group.

Polyamide, which is component D in the present invention, is a linear polymer having an amide bond, such as one obtained by polycondensation of an organic diamine and an organic dicarboxylic acid, one obtained by polycondensation of aminocaproic acid, and one obtained by polycondensation of aminocaproic acid. Some are obtained by ring-opening polymerization. Examples of organic diamines include:
Examples of the organic dicarboxylic acid include tetramethylene diamine, hexamethylene diamine, metaxylylene diamine, and the like, and examples of the organic dicarboxylic acid include adipic acid, sebacic acid, dodecanoic acid, terephthalic acid, and isophthalic acid.

Examples of the aminocaproic acid include 11-aminoundecanoic acid, and examples of the lactam include ε-caprolactam and ω-laurolactam. The polyamide may be a copolymer or a polymer blend thereof.

These components A to D may be mixed by melt-kneading using an extruder. In order to improve kneading properties, it is preferable to use a twin-screw extruder.

In the composition of the present invention, when the proportions of components A, B, C and D are a, bSc and 6% by weight, a+b+c+
It is necessary to satisfy the following conditions: d=100 0≦b/(a+b)≦0.17 0.01≦C≦10 10≦a+b≦50.

If b/(a+b) is larger than 0.17, the color B applied when introducing the acid anhydride group will spread over the entire composition, reducing the commercial value or forming a gel when extruding the composition. This is not desirable because it can cause

b/(a+b) is preferably 0.03 or more in consideration of improving the breakage of lances and legs.

C needs to be 0.01 or more. If it is less than 0.01, the impact resistance will not be improved sufficiently. Also, C
is preferably 10 or less. This is because even if more than 10 is added, the effect of improving impact resistance is not so significant, but the mechanical properties are significantly lowered.

a+b is 10 or more and 50 or less. If it is less than 10,
The lock feeling when absorbing water is not sufficiently improved, and 5
If it exceeds 0, heat resistance will decrease.

Further, when rigidity is required for the junction block, mineral powder such as talc or calcined kaolin, or a combination of these and glass fiber may be used in the polyamide composition of the present invention. The blending amount is preferably 3 to 10 parts by weight. If the amount is less than 3 parts by weight, almost no effect will be observed, and if it exceeds 10 parts by weight, the ductility will be significantly reduced.

The composition may contain additives well known for use in polyamides and polyolefins. Heat stabilizer, lubricant, mold release agent,
It may contain plasticizers, weathering agents, colorants, flame retardants, etc.

The automobile junction block of the present invention can be molded by injection molding or the like.

(Example) Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these.

Examples 1 to 3, Comparative Examples 1 to 5 Compositions as shown in Table 1 were manufactured, and test pieces and automobile junction blocks shown in the drawings were molded from the compositions by injection molding. The physical properties shown below were measured using the following materials. In addition, in the drawing, 1
2 is a fuse mounting part, 2 is a connector mounting part, and 3 is a fixing part.

The raw materials used, the test pieces, the method for making the automobile junction block, and the testing method will be explained.

(1) Raw materials ■Nylon 66 (Ny66) Nylon 66, number average molecular weight approximately 17,000 ■Polypropylene (PP) Asahi Kasei Polypro, grade name: M1600, MFR:
14 (ASTM 01238), manufactured by Asahi Kasei Industries, Ltd. PBT Higashi 1zPBT, grade name 1401XO6, Higashi Shiku Co., Ltd.)
■MHTR Hydrogenated styrene/butadiene block copolymer (molecular weight 50,000, styrene content 32% by weight) with 1.8% maleic anhydride added ■THPB Hydrogenated polybutadiene (1,2 adduct/1, 4 addition amount = 9/1, number average molecular weight 1000) 1 equivalent of terminal OH modified product (manufactured by Nippon Soda Co., Ltd., G1-1000), 4 equivalents and ethyl acetate as a solvent, in the presence of 4 equivalents of pyridine, The reaction was carried out at 0° C. for 1 hour and then at room temperature for 24 hours to obtain a modified polymer having the following structure.

This product was in the form of a paste.

(2) Sample Preparation Method Except for Comparative Example 1.2, pellets and paste were blended at the composition ratios shown in Table 1 and melt-kneaded using PCM 30 manufactured by Ikegai Tekko Co., Ltd. to obtain composition pellets.

(3) Creation of test piece The composition pellet was molded using an injection molding machine, and a bending test piece (
12,9CIIX1.3 cmXo, 3 cm strip) was prepared. Izot impact test pieces were prepared by cutting the bending test pieces.

(4) Test method ■Izotsu impact test (with notch) Tested according to 8STM D256.

■Flexural modulus (FM) ^Tested according to STM 13790.

In addition, FM (WET) is immersed in 80°C hot water for 8 hours and then in 23°C water for 16 hours, then heated to 23°C.
C1 FM measured after being left in an atmosphere with relative humidity of 50% for 48 hours.

Heat distortion temperature (4.6kg/cI11) (HDT:I
Tested according to ASTM 0790.

(4) Results Shown in Table 1.

As is clear from Table 1, the automotive junction box of the present invention has excellent impact resistance.

In addition, since the bending elastic modulus decreases little due to water absorption, it provides an excellent locking feeling when the connector is attached, which reduces mating errors. Furthermore, it has excellent heat resistance, so
Sufficiently durable for use in the engine compartment of a car.

(Effect of the invention) The automobile junction block of the invention has heat resistance,
Excellent chemical resistance and dimensional stability. In addition, since the locking feeling when installing the connector is excellent, there are fewer mistakes in connecting the connector when assembling the car.

[Brief explanation of the drawing]

Claims (1)

[Claims] A: Polypropylene B: A modified polymer in which an acid anhydride group is introduced into polypropylene and/or a copolymer of a vinyl aromatic compound and an olefin. C: A liquid olefin-based oligomer containing an acid anhydride group or a copolymerized oligomer of a vinyl aromatic compound and an olefin D: A composition consisting of a polyamide, in which the proportions of each component of A, B, C, and D are a , b, c, and d as weight percent, a+b+c+d=100 0≦b/(a+b)≦0.17 0.01≦c≦10 10≦a+b≦50 An automobile junction block molded from a polyamide composition. .