JP2932974B2 - Resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has excellent resistance to a road surface deicing agent mainly composed of a metal halide such as calcium chloride, magnesium chloride or zinc chloride, and has excellent impact resistance, rigidity and heat resistance. The present invention relates to polyamide underhood parts for automobiles.

[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 to resin for the purpose of reducing weight, improving rust resistance and sound insulation for improving fuel efficiency. Above all, 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, top and base of radiator tanks, cylinder head covers, oil pans, etc. Various functional parts such as gears, valves, brake pipes, tubes for fuel pipes, other exhaust system parts, and electric system parts such as connectors have been applied.

[0003] In general, a large amount of a deicing agent mainly composed of calcium chloride, magnesium chloride, zinc chloride or the like is sprayed on roads in cold regions to prevent road surface freezing in winter. Materials with high resistance to agents are required.

On the other hand, nylon 6 and nylon 66
Resin composition in which nylon 11 and nylon 12 are blended with nylon and their reinforced products (Japanese Patent Application Laid-Open No. 60-8806).
6, JP-A-57-212252), a polyamide resin composition in which an aliphatic polyamide and an aromatic polyamide are blended and their reinforced products (JP-A-58-120665, JP-A-58-53950, etc.), and a polyamide with phenol Resin compositions blended with resins and modified polyolefins and their reinforced products (JP-A-60-188456, JP-A-6-188456)
1-76540).

[0005]

With the recent rise in the temperature of the engine room of automobiles and the development of microelectronics due to technological innovation, there has been a demand for molding materials that can withstand use in high-temperature atmospheres.

However, these resin compositions are insufficient in mechanical properties such as tensile strength and flexural modulus and heat resistance as a metal substitute material, and are extremely restricted in applications due to high material prices. Only applied.

[0007]

SUMMARY OF THE INVENTION In view of the above circumstances, the present inventors have developed an automobile underhood component which is inexpensive, has good resistance to a road deicing agent, and has excellent impact resistance, rigidity and heat resistance. As a result of the study, they have found that a specific terephthalic acid-containing polyamide resin composition can solve all problems, and have reached the present invention.

That is, the present invention provides a repeating unit

Embedded image And repeat units

Embedded image (Wherein R represents an aliphatic group having 6 carbon atoms, and R ′ represents an aliphatic group having 4 carbon atoms), and the weight ratio of (I) / (II) is 10/90 to 90/10. Copolyamide [A]
Modified polyolefin [B] 1 to 100 parts by weight
100 parts by weight of a resin composition for an automobile underhood component comprising 1 to 100 parts by weight of a filler [C], and an automobile underhood component and an automobile cylinder head cover obtained by molding the resin composition. It is.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The copolymerized polyamide resin [A] of the present invention is defined as (I) an aliphatic alkylene terephthalamide synthesized from an aliphatic alkylene diamine having 6 carbon atoms and terephthalic acid, and optionally (II) A) a condensate formed from an aliphatic alkylenediamine having 6 carbon atoms and an aliphatic alkylenedicarboxylic acid having 6 carbon atoms. Specific examples of the aliphatic alkylenediamine having 6 carbon atoms include 1,4-diamino-1, 1-dimethylbutane and 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-
Examples thereof include diamino-2,3-dimethylbutane, 1,2-diamino-1-butylethane, 1,5-diamino-2-methylpentane, 1,6-diaminohexane and the like. Among these alkylenediamine components, 1,6-diaminohexane is preferred. As a specific example of the aliphatic alkylenedicarboxylic acid component unit having 6 carbon atoms, adipic acid is exemplified.

The copolymerization ratio of the copolymerized polyamide of the present invention must be such that (I) / (II) is in the range of 10/90 to 90/10 by weight, preferably 20/80 to 9/10.
0/10, more preferably 30/70 to 90/10. If the copolymerization ratio is less than 10/90, the resistance to metal halides decreases, and the resistance to road deicers decreases, which is not preferred. The degree of polymerization of the polyamide used here is not particularly limited, and the relative viscosity (ηr) at 25 ° C. of a 1% sulfuric acid solution is usually 1.5 to 1.5%.
What is in 5.0 can be used arbitrarily.

The method for producing the copolymerized polyamide of the present invention is not particularly limited, but the aqueous solution of the monomers or salts of the constituents (I) to (II) is stirred at a water vapor pressure of 20 kg / cm ² -G or less, 150 to 320 g. ° C, and ηr = 1.01-1.
A method of producing a low-order condensate of 6, and then performing a solid-phase polymerization at a temperature below the melting point or a method of increasing the degree of polymerization using a single-screw or twin-screw extruder with a vent port is simple and suitable. I have.

According to the present invention, the presence of a phosphorus-based catalyst is effective for obtaining good pellets having a high degree of polymerization in the melt extrusion step, and the amount of addition is 0.02 to 2 w
t% is preferable, and more preferably 0.05 to 1.2 wt%
%. Specific examples of phosphorus compounds include H ₃ PO ₄ and H
₃ PO ₃ , H ₃ PO ₂ , H ₄ P ₂ O ₇ , 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, N
_{a 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 P
O ₂ ) ₂ and (C ₆ H ₅ O) ₃ P. Preferred are H ₃ PO ₄ and H ₄ P ₂ O ₇ . There is no particular limitation on the method of adding the phosphorus compound, and a simple and suitable method is used for producing a low-order condensate, or a method of previously blending with the low-order condensate and melt-extruding.

The modified polyolefin [B] of the present invention includes ethylene, propylene, butene-1, pentene-1,4-
Methylpentene-1, isobutylene, 1,4-hexadiene, dicyclobentadiene, 2,5-norpolnadiene, 5-ethylidenenorporene, 5-ethyl-2,5
-Norbornadiene, 5- (1'-probenyl) -2-
Carboxylic acid group, carboxylic acid ester group, carboxylic acid metal group, carboxylic acid anhydride group, carboxylic acid amide group are added to polyolefin obtained by radical polymerization of at least one olefin selected from norpolene, butadiene, isoprene and styrene. A modified polyolefin obtained by introducing a component (hereinafter, referred to as a functional group-containing component) into a monomer having at least one functional group selected from an imide group and an aminohydroxyethyl group.

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 their carboxylic acid metal salts, methyl hydrogen maleate, methyl hydrogen itaconate, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth)
2-ethylhexyl acrylate, hydroxyethyl (meth) acrylate, aminoethyl (meth) acrylate, dimethyl maleate, dimethyl itaconate, maleic anhydride, itaconic anhydride, citraconic anhydride, endobicyclo- [2,2, Α, β-unsaturated carboxylic acid derivatives such as 1] -5-heptene-2,3-dicarboxylic acid and endobicyclo- [2,2,1] -5-heptane-2,3-dicarboxylic anhydride; The α, β-unsaturated carboxylic acid, its ester, its anhydride, glycidyl (meth) acrylate, (meth) acryl glycidyl ether, vinyl glycidyl ether and the like epoxy-containing saturated compounds described above in ammonia, methylamine, ethylamine, Butylamine, hexylamine, dodecylamine, oleylamine, stearyl Min, 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-monomethylamino-ε-caprolactam, α-monoethylamino-ε-caprolactam, α-monobenzylamino-ε-caprolactam,
N-substituted amide compounds, N-substituted imide compounds, N-substituted hydroxyethyl compounds, etc. obtained by adding a nylon oligomer having a terminal amino group.

The method for introducing these functional group-containing components is not particularly limited, and a method such as mixing with a main component olefin and copolymerizing it, or graft-introducing a polyolefin with a radical initiator is used. be able to. The amount of the functional group-containing component to be introduced is usually in the range of 0.001 to 40 mol%, preferably 0.01 to 35 mol%, based on the entire modified polyolefin.
If the content of the functional group-containing component is less than 0.001 mol%, the affinity between the modified polyolefin and the copolymerized polyamide is insufficient,
The effect of imparting impact resistance 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 polyolefins particularly useful in the present invention include ethylene / (meth) acrylic acid copolymers, and those in which some or all of the carboxylic acid moieties in these copolymers are sodium, lithium, zinc, Salted with calcium, potassium, etc., ethylene / (meth)
Methyl acrylate copolymer, ethylene / ethyl (meth) acrylate copolymer, ethylene / ethyl (meth) acrylate-g-maleic anhydride copolymer (“g” represents a graft; the same applies 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 copolymer and partially saponified products of these copolymers, ethylene / propylene g Maleic anhydride copolymer, ethylene / butene 1-g
-Maleic anhydride copolymer, 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-g-N-phenylmaleimide copolymer, styrene / butadiene-g-maleic anhydride Acid copolymers, styrene / maleic anhydride copolymers and the like can be mentioned.

The compounding amount of the modified polyolefin is 1 to 100 parts by weight based on 100 parts by weight of the copolymerized polyamide.
Preferably it is in the range of 5 to 90 parts by weight. The amount is 1
If the amount is less than 100 parts by weight, the resulting molded article has insufficient impact resistance, and if it exceeds 100 parts by weight, the heat resistance of the molded article is insufficient.

The filler [C] referred to in the present invention includes glass fibers or beads, talc, carion, wollastonite, mica, silica, alumina, diatomaceous earth, clay, gypsum, red iron oxide, graphite, titanium dioxide, Examples thereof include powdery or plate-like inorganic compounds such as zinc oxide, copper, and stainless steel, and other polymer fibers (carbon fibers), and preferably glass fibers. Particularly preferred as glass fibers are glass chopped strands and glass threads having a diameter of about 3 to 20 μm. The mixing ratio of the filler is 1 to 1 with respect to 100 parts by weight of the copolyamide.
It must be in the range of 00 parts by weight, preferably in the range of 5 to 90 parts by weight, particularly preferably in the range of 10 to 90 parts by weight. If the compounding amount of the filler exceeds 100 parts by weight, the fluidity at the time of melting is deteriorated, and not only is it difficult to injection-mold the molded product, but also the appearance of the molded product is deteriorated.

The method of blending the filler with the copolymerized polyamide of the present invention is not particularly limited, and any known method can be used. Specific examples of the compounding method include a method in which a modified polyolefin and a filler are dry-blended into pellets of a copolymerized polyamide and melt-kneaded with a single screw or twin screw extruder.

The automotive underhood component of the present invention is molded by subjecting the polyamide resin composition to a known molding method such as injection molding, extrusion molding, blow molding, vacuum molding and the like. Examples of molded products include cooling fans,
Examples include a radiator tank, a cylinder head cover, an oil pan, a gear, a valve, a brake pipe, a fuel pipe, other tubes, pipes, other exhaust gas system components, and connectors.

Incidentally, the molded part obtained in this way can be subjected to secondary processing such as painting, vapor deposition, lamination and the like.

In addition, the resin composition of the present invention for automobile underhood parts may contain other components such as a pigment, a dye, a heat-resistant agent, a catalyst, an antioxidant, and the like in any step as long as the moldability and physical properties are not impaired. Agents, weathering agents, lubricants,
Crystal nucleating agents, antistatic agents, plasticizers, other polymers and the like can be added.

[0023]

The present invention will be described in more detail with reference to the following 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 heating rate of 20 ° C./min using DSC (PERKIN-ELMER7 type) is defined as (T). . Samples 8 to 10 mg are heated at a heating rate of 20 ° C./min, and T + 2
Hold at 0 ° C. for 5 minutes, then cool to 30 ° C. at a rate of 20 ° C./min, hold at 30 ° C. for 5 minutes,
Heat to T + 20 ° C at 0 ° C / min. The maximum value of the melting curve at this time was defined as the melting point (Tm). (2) Calcium chloride resistance Underwater molded product is immersed in hot water at 90 ° C for 24 hours, then left in a oven at 100 ° C, and sprayed with a 50% calcium chloride solution in the form of water drops every hour. Was taken as one cycle, and the number of cycles until cracks occurred in the molded article was measured. (3) Appearance of molded article The surface of the molded article was observed to be rough, bubbles, color tone, gloss and the like. ：: 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 article were measured by the following methods. Tensile strength: ASTM-D638 Flexural strength: ASTM-D790 Flexural modulus: ASTM-D790 Izod impact strength: ASTM-D256 Thermal deformation temperature (HDT): ASTM-D648 Load 4.6 kgf / cm ² Load 18.6 kgf / cm ²

Example 1 5.89 kg of terephthalic acid and 6 of hexamethylenediamine
6.37 kg of a 4.5 wt% aqueous solution, 10.00 kg of hexamethyleneammonium adipate (66 salt) and 6.66 kg of ion-exchanged water were charged into a 0.05 m ³ batch-type pressure gun rear pot, and were charged in the same manner as in Example 1. The following condensate was made:
The low-order condensate obtained had Tm = 296 ° C. and ηr = 1.26.
Met. After vacuum drying this low-order condensate at 100 ° C. for 24 hours, it was melt-extruded at a temperature of melting point + 20 ° C. using a vent-type twin screw extruder of 30 mmφ, and ηr =
3.25, pellets with Tm = 295 ° C. were obtained. 100 parts by weight of the pellets contain 43 parts by weight of a glass fiber chopped strand having a length of 3 mm and a diameter of 13 μφ and 2 mol% of maleic anhydride, and a melt index of 7 g /
After dry blending 20 minutes by weight of an ethylene / ethyl acrylate / maleic anhydride copolymer for 10 minutes,
Was melt-kneaded and pelletized at a temperature of Tm + 20 ° C. using a twin screw extruder of No.

After the pellets are vacuum dried, the cylinder temperature is Tm + 20 ° C. and the mold temperature is 80 ° C. by an injection molding machine.
ASTM standard physical property test piece and length 450m
A box-shaped cylinder head cover of m, width 200 mm, height 80 mm, and thickness 3.5 mm was formed. Table 1 shows the results of evaluating the mechanical properties, heat distortion temperature, and resistance to metal halides using the molded pieces obtained here.

Examples 2-3 The properties of test pieces and molded articles obtained by performing the same operations as in Example 1 by changing the type of polyamide, the type of modified polyolefin, the type of filler, and the amount of compounding were evaluated. The results are shown in Table 1.

[0027]

[Table 1]

Comparative Example 1 Diameter 3 m with respect to 100 parts by weight of nylon 66 pellets
m, glass fiber chopped strand 4 with a diameter of 13μφ
3 parts by weight were dry blended to prepare a test piece and a cylinder head cover in the same manner as in Example 1. Table 2 shows the evaluation results. The calcium chloride resistance of this molded article was poor.

Comparative Example 2 65 parts by weight of glass fiber chopped strands were dry blended with 12 parts by weight of nylon and 100 parts by weight, and a test piece and an underhood part 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 3 7.21 kg of terephthalic acid and 6 of hexamethylenediamine
7.80 kg of a 4.5 wt% aqueous solution, 5.25 kg of ε-caprolactam and 6.10 kg of ion-exchanged water are 0.05 m in length.
^After charging into a batch-type pressure polymerization reactor of No. ³ and sufficiently replacing with nitrogen, heating was continued under a steam pressure of 17.5 kg / cm ² -G. After heating under stirring 5hr over 230 ° C., it was allowed to proceed for an additional 30min between reaction at 230 ° C. to 245 ° C., the pressure difference from the polymerization can bottom stop stirring 17.5 kg / cm ² -
In G, the lower condensate was extracted into water. The obtained low-order condensate had Tm = 303 ° C. and ηr = 1.21. The low-order condensate is vacuum-dried at 100 ° C. for 24 hours, and then dried under a N ₂ blow atmosphere using a kneader having an internal volume of 30 L.
Solid-state polymerization was carried out at a temperature of 3 ° C. for 3 hours to obtain a polymer having a high degree of polymerization. The obtained polymer had ηr = 2.75 and Tm =
303 ° C.

With respect to 100 parts by weight of the highly polymerized pellets, 43 parts by weight of a glass chopped strand having a length of 3 mm and a diameter of 13 μφ were dry blended, a molded article was prepared by the method of Example 1, and the evaluation results were obtained. The results are shown in Table 2. Impact resistance was low.

COMPARATIVE EXAMPLE 4 Ethylene / propylene / butene-1-ene containing 2 mol% of maleic anhydride and a melt index of 0.4 g / 10 min based on 100 parts by weight of the polymer having a high degree of polymerization obtained in Comparative Example 3. 20 parts by weight of the g-maleic anhydride copolymer were dry blended to form a molded article according to the method of Example 1, and the evaluation results are shown in Table 2. Flexural modulus was low.

Comparative Example 5 With respect to 100 parts by weight of the highly polymerized polymer of Comparative Example 3,
The same copolymer and glass fiber as in Example 1 were dry-blended to form a molded article by the method of Example 1, and the evaluation results are shown in Table 1. Polymer used in this comparative example (nylon 6T
/ 6) has a higher melting point than the polymer of Example 1 (nylon 6T / 66), but has a higher heat distortion temperature (HDT (18.6 kgf).
/ cm2)) and calcium chloride resistance were low.

[0034]

[Table 2]

[0035]

The underhood parts for automobiles obtained from the present invention have high rigidity, high impact resistance and high heat resistance, and are resistant to a road surface deicing agent mainly composed of a metal halide such as calcium chloride or zinc chloride. Good.

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-2-67360 (JP, A) JP-A-60-144362 (JP, A) JP-A-2-127466 (JP, A) JP-A-60-144 118735 (JP, A) JP-A-58-53950 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08L 77/00-77/12 C08K 3/00-3/40 C08L 23/26-23/36 F02B 77/00-77/14

Claims (3)

(57) [Claims] 1. A repeating unit And the repeating unit (Wherein R represents an aliphatic group having 6 carbon atoms, and R ′ represents an aliphatic group having 4 carbon atoms), and the weight ratio of (I) / (II) is 10/90 to 90/10. Copolyamide [A]
Modified polyolefin [B] 1 to 100 parts by weight
A resin composition for automobile under-hood parts, comprising a blend of 100 parts by weight and 1 to 100 parts by weight of a filler [C]. 2. An underhood part for automobiles, which is obtained by molding the resin composition according to claim 1. 3. An automobile cylinder head cover formed by molding the resin composition according to claim 1.