JP2505619B2 - Under hood parts for automobiles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention has good resistance to a road surface antifreezing agent containing a metal halogen compound such as calcium chloride, magnesium chloride or zinc chloride as a main component, and further has impact resistance and rigidity. The present invention also relates to an underhood component for automobiles made of polyamide, which is excellent in heat resistance and the like.

<Prior Art> In recent years, in the automobile industry, there has been a remarkable tendency to use conventional metal parts as resin for the purpose of weight reduction for improving fuel efficiency, rust prevention and sound insulation. Among them, polyamide resins have excellent heat resistance, oil resistance, moldability, and toughness, so they are used in underhood parts of automobiles such as cooling fans, radiator tank tops and bases, cylinder head covers, and oil pans. , Gears, valves, brake pipes, tubes for fuel pipes, other exhaust gas system parts, and various functional parts such as electrical system parts such as connectors.

In general, roads in cold regions are sprayed with large amounts of antifreeze agents containing calcium chloride, magnesium chloride, zinc chloride, etc. as main agents to prevent road surface freezing, especially in winter. High-quality materials are required.

In contrast, nylon 6 or nylon 66 and nylon 11
And nylon 12 blended polyamide resin compositions and their reinforced products (JP-A-60-88066, JP-A-57-212252, etc.), aliphatic polyamide and aromatic polyamide blended polyamide resin compositions and their reinforcement Product (JP-A-58
-120665, JP-A-58-53950, etc.), resin compositions obtained by blending a polyamide with a phenol resin or a modified polyolefin, and reinforced products thereof (JP-A-60-188456, JP-A-61-7654).
0) etc. have been proposed.

<Problems to be Solved by the Invention> With the recent increase in the temperature of the engine room of automobiles and the progress of microelectronics due to technological innovation, there has been a demand for a molding material that can sufficiently withstand use in a high temperature atmosphere.

However, these resin compositions are insufficient in mechanical properties such as tensile strength and bending elastic modulus as a metal substitute material and heat resistance, and because of high material cost, they are applied only to extremely limited applications. .

<Means for Solving the Problems> In light of the above circumstances, the present inventors have found that they are inexpensive and have good resistance to road deicing agents, and have excellent resistance to road deicing agents such as impact resistance, rigidity and heat resistance. As a result of studying the under hood parts for automobiles, which has been required, it was found that a specific terephthalic acid-containing polyamide resin composition can solve all the problems and reached the present invention.

That is, the present invention is a repeating unit And any of repeating units (II) and (III), (In the formula, R is an aliphatic group having 8 to 18 carbon atoms, and R'is 6 to 8 carbon atoms.
18 is an aliphatic group, R ″ is an aliphatic group having 4 to 18 carbon atoms or And n represents an integer of 5-18. ) And (I) / [(II) or (III)] in a weight ratio of 20/80 to 100/0 (co) polymerized polyamide [A] 100
A molded product obtained by molding 1 to 100 parts by weight of a modified polyolefin [B] and 1 to 100 parts by weight of a [C] filler with respect to parts by weight. It is an underhood component for automobiles, which is a component that

The copolyamide resin [A] of the present invention means (I) an aliphatic alkylene terephthalamide synthesized from an aliphatic alkylene diamine having 8 to 18 carbon atoms and terephthalic acid, (I
I) An aliphatic alkylene isophthalamide synthesized from an aliphatic alkylenediamine having 6 to 18 carbon atoms and isophthalic acid, or an aliphatic alkylenediamine having 6 to 18 carbon atoms and an aliphatic alkylenedicarboxylic acid having 4 to 18 carbon atoms It is a condensate. Specific examples of the aliphatic alkylenediamine having 6 to 7 carbon atoms include 1,4-diamino-1,1-dimethylbutane, 1,4-diamino-1-ethylbutane, 1,4-
Diamino-1,2-dimethylbutane, 1,4-diamino-1,3
-Dimethylbutane, 1,4-diamino-1,4-dimethylbutane, 1,4-diamino-2,3-dimethylbutane, 1,2-diamino-1-butylethane, 1,6-diaminohexane, 1,7
-Diaminoheptane is exemplified, and as the aliphatic alkylenediamine having 8 to 18 carbon atoms, 1,8-diaminooctane,
1,6-diamino-2,5-dimethylhexane, 1,6-diamino-2,4-dimethylhexane, 1,6-diamino-3,3-dimethylhexane, 1,6-diamino-2,2-dimethylhexane , 1,9-diaminononane, 1,6-diamino-2,2,4-trimethylhexane, 1,6-diamino-2,4,4-trimethylhexane, 1,7-diamino-2,3-dimethylhexane, 1,
7-diamino-2,4-dimethylheptane, 1,7-diamino-2,5-dimethylheptane, 1,7-diamino-2,2-dimethylheptane, 1,10-diaminodecane, 1,8-diamino- 1,3-dimethyloctane, 1,8-diamino-1,4-diaminooctane, 1,8-diamino-2,4-dimethyloctane, 1,8-diamino-3,4-dimethyloctane, 1,8- Diamino-4,5-dimethyloctane, 1,8-diamino-2,2
-Dimethyloctane, 1,8-diamino-3,3-dimethyloctane, 1,8-diamino-4,4-dimethyloctane, 1,6
-Diamino-2,4-diethylhexane, 1,9-diamino-
5-methylnonane, 1,11-diaminoundecane, 1,12-
Diaminododecane etc. can be illustrated. Of these alkylenediamine components, 1,6-diaminohexane, 1,8-diaminooctane, 1,10-diaminodecane, 1,12-diaminododecane or a mixture thereof is preferable. Further, specific examples of the aliphatic alkylenedicarboxylic acid component unit having 6 to 18 carbon atoms include adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, praciric acid,
Examples thereof include tetradecanedioic acid, pentadecanedioic acid and octadecanedioic acid. Of these aliphatic alkylenedicarboxylic acid components, adipic acid, sebacic acid, undecanedioic acid and dodecanedioic acid are preferred. (III) is a compound formed from a lactam or an aliphatic aminocarboxylic acid component having 5 to 18 carbon atoms. Specific examples of the lactams include ε-caprolactam, ζ-enanthlactam, η-capryllactam, ω-laurolactam, and the like, and ε-caprolactam is particularly preferable. Carbon number 5
Specific examples of the aliphatic aminocarboxylic acid component of ~ 18 are 6
-Aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and the like can be exemplified.

The copolymerization ratio of the (co) polymerized polyamide of the present invention must be such that the weight ratio of (I) / [(II) or (III) is in the range of 20/80 to 100/0, preferably 20 / 80-90 / 10,
It is more preferably 30/70 to 90/10. Copolymerization ratio is 20/8
If it is less than 0, the resistance to metal halides decreases, and the road deicing agent resistance decreases, which is not preferable. The degree of polymerization of the polyamide used here is not particularly limited, and one having a relative viscosity (ηr) of a 1% sulfuric acid solution at 25 ° C. of 1.5 to 5.0 can be arbitrarily used.

The method for producing the (co) polymerized polyamide of the present invention is not particularly limited, but the water vapor pressure is 20 kg / cm ² -G or less, 150
Heat at ~ 320 ° C to make a low-order condensate with ηr = 1.01 to 1.6 and solid-phase polymerize it at a temperature below the melting point, or use a single screw or ventilated screw extruder for high polymerization The method of grading is simple and suitable.

According to the present invention, the presence of a phosphorus-based catalyst is effective for obtaining a good highly polymerized pellet in the melt extrusion step,
The addition amount is preferably 0.02 to 2 wt% with respect to the low-order condensate,
More preferably, it is 0.05 to 1.2 wt%. Specific examples of phosphorus compounds include H ₃ PO ₄ , H ₃ PO ₃ , H ₃ PO ₂ , H ₄ P ₂ O ₇ , and NaH ₂ PO _4.
2 H ₂ O, Na ₂ HPO ₄ , 12H ₂ O, Na ₃ PO ₄ , 12H ₂ O, NaH ₂ PO ₄ , H
₂ O, Na ₄ P ₂ O ₇ · 10H ₂ O, Na ₂ H ₂ P ₂ O ₇ · 6H ₂ O, Na ₅ P ₃ O ₁₀ , C _{6
H 5 P (OH) 2,} C 6 H 5 PO (ONa) 2, C 6 H 5 PO (OH) 2, Mn (H 2 PO 2) 2,
(C6 ₆ H ₅ O) ₃ P and the like can be mentioned. Preferably H ₃ PO
₄ , H ₄ P ₂ O ₇ . The addition method of the phosphorus compound is not particularly limited, and a method of preparing a low-order condensate, or a method of previously blending with the low-order condensate and melt-extruding is convenient and suitable.

The modified polyolefin [B] of the present invention is ethylene, propylene, butene-1, pentene-1,4-methylpentene-1, isobutylene, 1,4-hexadiene, dicyclopentadiene, 2,5-norpornadiene, 5-ethylidene. Polyolefin obtained by radical polymerization of at least one olefin selected from norporne, 5-ethyl-2,5-norbornadiene, 5- (1'-probenyl) -2-norbornene, butadiene, isoprene and styrene. A monomer having at least one functional group selected from a carboxylic acid group, a carboxylic acid ester group, a carboxylic acid metal group, a carboxylic acid anhydride group, a carboxylic acid amide group, an imide group, and an aminohydroxyethyl group. Is a modified polyolefin obtained by introducing a component (hereinafter referred to as a functional group-containing component).

Examples of the functional group-containing component include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, methylmaleic acid, methylfumaric acid, mesaconic acid,
Citraconic acid, glutaconic acid and carboxylic acid metal salts thereof, methyl hydrogen maleate, methyl hydrogen itacone, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid 2 -Ethylhexyl, hydroxyethyl (meth) acrylate, aminoethyl (meth) acrylate, dimethyl maleate, dimethyl itaconate, maleic anhydride, itaconic anhydride, citraconic anhydride, endobicyclo- [2,2,
1] -5-heptene-2,3-dicarboxylic acid, α, β-unsaturated carboxylic acid derivatives such as endobicyclo- [2,2,1] -5-heptane-2,3-dicarboxylic acid anhydride, and here The α, β-unsaturated carboxylic acid, its ester, its anhydride, glycidyl (meth) acrylate, (meth) acrylic glycidyl ether, epoxy-containing saturated compounds such as vinyl glycidyl ether, ammonia, methylamine, ethylamine, Butylamine, hexylamine,
Dodecylamine, oleylamine, stearylamine,
Cyclohexylamine, benzylamine, aniline, naphthylamine, dimethylamine, diethylamine, methylethylamine, dibutylamine, distearylamine, dicyclohexylamine, ethylcyclohexylamine, methylaniline, phenylnaphthylamine, melamine, ethanolamine, 3-amino-1-propanol , Diethanolamine, morpholine, α-amino-2
-Pyrrolidone, α-amino-ε-caprolactam, α-
N-substituted amide compounds obtained by adding monomethylamino-ε-caprolactam, α-monoethylamino-ε-caprolactam, α-monobenzylamino-ε-caprolactam, nylon oligomers having terminal amino groups, N-substituted imides Compounds, N-substituted hydroxyethyl compounds and the like.

The method of introducing these functional group-containing components is not particularly limited, and it is possible to use a method of mixing with the main component olefins for copolymerization, or a method of graft-introducing the polyolefin with a radical initiator. . The amount of the functional group-containing component to be introduced is usually 0.001 to 40 mol%, preferably 0.01 to 35 mol%, based on the whole modified polyolefin. The amount of functional group-containing components is 0.001
If the amount is less than mol%, the affinity between the modified polyolefin and the copolyamide is insufficient, and the impact resistance imparting effect tends to be insufficient. On the other hand, when the amount of the functional group-containing component exceeds 40 mol%, side reactions such as gelation tend to occur easily.

Specific examples of the modified polyolefin particularly useful in the present invention include ethylene / (meth) acrylic acid copolymers, and some or all of the carboxylic acid moieties in these copolymers are sodium, lithium, zinc, calcium and potassium. And the like, a salt thereof, an ethylene / (meth) acrylate copolymer, an ethylene / (meth) acrylate copolymer, an ethylene / (meth) acrylate-g-maleic anhydride copolymer (“ g "represents a graft. The same shall apply hereinafter), ethylene / methyl (meth) acrylate-g-maleic anhydride copolymer, ethylene / ethyl (meth) acrylate copolymer, ethylene / ethyl acrylate-g-maleimide Copolymer, ethylene / ethyl acrylate-g-
Phenylmaleimide copolymers and partially saponified products of these copolymers, ethylene / propylene g-maleic anhydride copolymers, ethylene / butene 1-g-maleic anhydride copolymers, ethylene / propylene / 1,4-hexadiene -G
-Maleic anhydride copolymer, ethylene / propylene / dicyclopentadiene-g-maleic anhydride copolymer, ethylene / propylene / 2,5-norbornadiene-g-maleic anhydride copolymer, ethylene / propylene-g- N-
Phenylmaleimide copolymer, ethylene / butene-1-
Examples thereof include g-N-phenylmaleimide copolymer, styrene / butadiene-g-maleic anhydride copolymer, and styrene / maleic anhydride copolymer.

The amount of modified polyolefin is 100
1 to 100 parts by weight, preferably 5 to 9 parts by weight
It is within the range of 0 parts by weight. If the blending amount is less than 1 part by weight, the resulting molded article lacks impact resistance, and if it exceeds 100 parts by weight, the molded article lacks heat resistance, which is not preferred.

The filler [C] referred to in the present invention means glass fibers or beads, talc, carion, wollastonite, mica, silica, alumina, diatomaceous earth, clay, gypsum, red iron oxide, graphite, titanium dioxide, zinc oxide, Powdery or plate-like inorganic compounds such as copper and stainless steel, other polymer fibers (carbon fibers), etc., and preferably glass fibers. Particularly preferred glass fibers are glass chopped strands and glass threads having a diameter of about 3 to 20 μm. The blending ratio of such a filler must be in the range of 1 to 100 parts by weight, preferably 5 to 90 parts by weight, particularly preferably 10 to 90 parts by weight, based on 100 parts by weight of the copolyamide. is there. If the blending amount of the filler exceeds 100 parts by weight, the fluidity at the time of melting deteriorates,
Not only is it difficult to injection-mold molded parts,
This is not preferable because the appearance of the molded product will deteriorate.

The method of adding the filler to the copolyamide of the present invention is not particularly limited, and any known method can be used. Specific examples of the mixing method include a method in which pellets of copolyamide are dry-blended with a modified polyolefin and a filler, and the resulting mixture is melt-kneaded with a single-screw or twin-screw extruder.

The underhood component for automobiles of the present invention is molded by subjecting the above polyamide compound to a known molding method such as injection molding, extrusion molding, blow molding, or vacuum molding.
Examples of molded products include cooling fans, radiator tanks, cylinder head covers, oil pans, valves, brake pipes, fuel pipes, other tubes, pipes, other exhaust gas system parts, connectors and the like.

The molded parts thus obtained may be subjected to secondary processing such as painting, vapor deposition and lamination.

In addition, in the underhood parts for automobiles of the present invention, other components such as pigments, dyes, heat-resistant agents, catalysts and
Antioxidants, weathering agents, lubricants, crystal nucleating agents, antistatic agents, plasticizers, other polymers and the like can be added.

<Examples> The present invention will be described in more detail below with reference to Examples.
Various properties in the examples and comparative examples were measured by the following methods.

(1) Melting point (Tm) The temperature showing the maximum value of the melting curve obtained by measuring 8 to 10 mg of a sample at a temperature rising rate of 20 ° C / min using DSC (PERKIN-ELMER7 type) is defined as (T). . Heat 8 to 10 mg of sample at a heating rate of 20 ° C / min and hold at T + 20 ° C for 5 minutes, then
After cooling to 30 ° C. at a temperature decrease rate of ° C./min, holding at 30 ° C. for 5 minutes, heating again to 20 ° C./min to T + 20 ° C.
The maximum value of the melting curve at this time was taken as the melting point (Tm).

(2) Calcium chloride resistance test After immersing an underhood molded product in warm water at 90 ° C for 24 hours, leave it in a gear oven at 100 ° C, and spray 50% calcium chloride solution every hour with water drops. Processing 1
As a cycle, the number of cycles until cracking occurred in the molded product was measured.

(3) Appearance of molded product The surface of the molded product was observed to be rough, air bubbles, color tone and gloss.

：: glossy and smooth surface.

Δ: The gloss is reduced, but the surface is smooth.

X: The surface is rough without gloss.

(4) The physical properties of the molded product were measured by the following methods.

Tensile strength: ASTM-D638 Bending strength: ASTM-D790 Bending elastic modulus: ASTM-D790 Izod Impact strength: ASTM-D256 Heat distortion temperature (HDT): ASTM-D648 Load 4.6kgf / cm ² Load 18.6kgf / cm ² Comparative example 1 7.21kg of terephthalic acid, 64.5 of hexamethylenediamine
A wt% aqueous solution of 7.80 kg, ε-caprolactam of 5.25 kg, and ion-exchanged water of 6.10 kg were charged into a 0.05 m ³ batch-type pressure polymerization kettle, and after sufficiently purging with nitrogen, a steam pressure of 17.5 kg / cm ² -G
Heating was continued under pressure. After heating to 230 ℃ for 5 hours with stirring, and further proceeding the reaction at 230 ℃ ~ 245 ℃ for 30 minutes, stop stirring and lower-order condensate at the differential pressure of 17.5 kg / cm ² -G from the bottom of the polymerization vessel. Was extracted into the water. The low-order condensate obtained is
Tm = 303 ° C. and ηr = 1.21. 100% of this low-order condensate
After vacuum-drying at 24 ° C. for 24 hours, solid-state polymerization was performed for 3 hours at 250 ° C. in a N ₂ blow atmosphere using a kneader with an internal volume of 301 to obtain a highly polymerized polymer. The obtained polymer had ηr = 2.75 and Tm = 303 ° C. This polymer 100
Contains 43 parts by weight of glass fiber chopped strands having a true diameter of 13 μφ and 3 parts by weight with respect to parts by weight, and 2 mol% of maleic anhydride, and has a melt index of 0.4 g / 10 min ethylene / propylene / butene-1-g-anhydrous. After 20 parts by weight of the maleic acid copolymer was dry blended, it was melt-kneaded and pelletized by using a 30 mmφ twin screw extruder at a temperature condition of Tm + 20 ° C.

After vacuum-drying these pellets, an injection molding machine is used to measure the ASTM standard physical properties under a cylinder temperature of Tm + 20 ° C and a mold temperature of 80 ° C, and a box type with a length of 450 mm, a width of 200 mm, a height of 80 mm, and a wall thickness of 3.5 mm. A cylinder head cover was molded.
Table 2 shows the results of evaluation of mechanical properties, heat distortion temperature, and resistance to metal halides using the molded pieces obtained here.

Examples 1 to 5 Test pieces and molded articles obtained by performing the same operation as in Comparative Example 1 while changing the type of polyamide, the type of modified polyolefin, the type of filler, the compounding amount, and the like. The results of evaluating these characteristics are shown in Table 1.

Comparative Example 2 43 parts by weight of glass fiber chopped strands having a diameter of 3 mm and a diameter of 13 μφ were dry blended with 100 parts by weight of nylon 66 pellets to prepare a test piece and a cylinder head cover in the same manner as in Comparative Example 1. The calcium chloride resistance of this molded product was poor.

Comparative Example 3 65 parts by weight of glass fiber chopped strands were dry blended with 100 parts by weight of nylon 12 pellets, and a test piece and a cylinder head cover were prepared in the same manner as in Example 1. When the physical properties of the obtained test piece were evaluated, the rigidity and the heat distortion temperature were insufficient as shown in Table 2.

Comparative Example 4 With respect to 100 parts by weight of the highly polymerized pellets of Comparative Example 1,
Glass chopped strand 43 with a length of 3 mm and a diameter of 13 μφ
By weight blending parts by weight, a molded product was prepared by the method of Comparative Example 1, and the evaluation results are shown in Table 2. The impact resistance was low.

Comparative Example 5 Ethylene / propylene / butene-1 containing 2 mol% of maleic anhydride based on 100 parts by weight of the highly polymerized pellets obtained in Comparative Example 1 and having a melt index of 0.4 g / 10 min.
20 parts by weight of -g-maleic anhydride copolymer was dry-blended, a molded product was prepared by the method of Comparative Example 1, and the evaluation results are shown in Table 2. Flexural modulus was low.

Comparative Example 6 The modified polyolefin and the filler shown in Table 2 were blended with the high degree of polymerization pellets obtained in Comparative Example 1,
A molded product was prepared in the same manner as in Comparative Example 1. Table 2 shows the evaluation results. Although the polyamide of this comparative example (nylon 6T / 6) has a higher melting point than the nylon 12T / 66 of Example 1, the heat distortion temperature (HDT (18.6 kgf
/ cm ² )) was low.

<Effects of the Invention> The underhood parts for automobiles of the present invention have high rigidity, high impact resistance and high heat resistance, and have good resistance to a road surface antifreezing agent containing a metal halogen compound such as calcium chloride or zinc chloride as a main component. is there.

Claims (1)

(57) [Claims] 1. The repeating unit And any of repeating units (II) and (III), (In the formula, R is an aliphatic group having 8 to 18 carbon atoms, and R'is 6 to 8 carbon atoms.
18 is an aliphatic group, R ″ is an aliphatic group having 4 to 18 carbon atoms or And n represents an integer of 5-18. ) And (I) / [(II) or (III)] in a weight ratio of 20/80 to 100/0 (co) polymerized polyamide [A] 100
The composition comprises 1 to 100 parts by weight of the modified polyolefin [B] and 1 to 100 parts by weight of the [C] filler, and is required to have resistance to a road surface antifreezing agent. Under hood parts for automobiles, which are parts that are