JP2014028889A - Automobile under-hood component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automobile under-hood component exhibiting a fresh color and in which discoloring and fading by heating is reduced.SOLUTION: An automobile under-hood component is produced by molding a red polyamide resin composition containing 100 pts.wt. of a polyamide resin (A), 0.10 to 2.5 pts.wt. of an inorganic pigment (B) and 0.10 to 0.50 pts.wt. of an organic pigment (C) and satisfies a relation of values of a color space coordinate in a CIE1976(L,a,b) colorimetric system of L≥26, a≥32 and b≥22.

Description

  The present invention relates to an automobile underhood component formed by molding a red polyamide resin composition that is vivid and has little color change due to heat.

  In recent years, with increasing environmental awareness, there has been a strong demand for weight reduction with resin to improve automobile fuel efficiency. Polyamide is a material that is well balanced in terms of cost as well as excellent strength and heat resistance, and is already used in various automobile parts. In particular, polyamide is widely used for automotive underhood parts.

  However, depending on the environment in which the polyamide is used, the polyamide may change color after a lapse of time. In particular, the discoloration after the aging becomes prominent in an environment used for automobile underhood parts that are strongly affected by heat. For example, a non-colored polyamide resin molded product may change from yellow to brown when used in a high-temperature environment, and the appearance may be significantly reduced. For this reason, many polyamide resin molded products are blackened.

  Recently, automotive underhood parts are sometimes required to have a design, and one of them is the need for red parts. As a method of coloring polyamide in red, a method of adding an appropriate amount of a dye, an organic pigment, or an inorganic pigment is known, but there is no method that satisfies both color development and color fading.

  As the red resin composition, there has been proposed a resin composition for a laser light absorbing member containing 0.001 to 10 parts by weight of a red inorganic pigment with respect to 100 parts by weight of a thermoplastic resin (for example, , See Patent Document 1). In addition, a composition comprising a specific amount of polyamide resin, an inorganic colorant, zinc sulfide, copper halide, potassium halide, and a triazine derivative has been proposed as a colored polyamide resin composition excellent in fading and fading due to heat and light. (For example, refer to Patent Document 2). However, a molded product obtained by molding such a resin composition has a problem in color development.

JP 2007-177053 A JP-A-1-156364

  An object of the present invention is to provide an automobile underhood component that expresses a vivid color and reduces discoloration due to heat.

  The present inventors have found that by using a polyamide resin composition in which an inorganic pigment and an organic pigment are used in combination, a vivid color is expressed and a color fading due to heat is reduced. That is, the configuration of the present invention is as follows.

(1) The inorganic pigment (B) is contained at a ratio of 0.10 to 2.5 parts by weight with respect to 100 parts by weight of the polyamide resin (A), and the organic pigment (C) is 0.10 to 0.00. A red polyamide resin composition containing 50 parts by weight is molded, and the color space coordinate (JIS Z8729) value in the CIE 1976 (L ^* , a ^* , b ^* ) notation is L ^* ≧ 26, a An automotive underhood component satisfying the relationship of ^* ≧ 32 and b ^* ≧ 22.

(2) The automobile underhood component according to (1), wherein the red polyamide resin composition contains the inorganic filler (D) in a proportion of 20 to 80 parts by weight.

(3) The automobile underhood component according to (1) or (2), wherein the inorganic pigment (B) contains bengara.

(4) The automobile underhood component according to any one of (1) to (3), wherein the organic pigment (C) contains a perinone / perylene compound.

(5) The automobile underhood component according to any one of (1) to (4), wherein the color change ΔE ^* after holding at 120 ° C. for 1000 hours is 5 or less.

  ADVANTAGE OF THE INVENTION According to this invention, the motor vehicle under hood component which expresses a vivid color and there is little discoloration by heat can be provided.

  Embodiments of the present invention will be described below. The polyamide resin (A) used in the present invention is a polyamide resin mainly composed of amino acids, lactams or diamines and dicarboxylic acids. Representative examples of the main components include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid, lactams such as ε-caprolactam and ω-laurolactam, tetramethylenediamine, hexamethylenediamine, Aliphatic diamines such as 2-methylpentamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, Examples thereof include aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid and dodecanedioic acid, terephthalic acid or esters thereof, and aromatic dicarboxylic acids derived from acid halides. In the present invention, nylon homopolymers or copolymers derived from these raw materials can be used, and two or more of these may be used.

  Specific examples of the polyamide resin (A) particularly preferably used in the present invention include polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), polyhexamethylene sebacamide (polyamide 610). , Polyhexamethylene dodecanamide (polyamide 612), polyundecanamide (polyamide 11), polydodecanamide (polyamide 12), polycaproamide / polyhexamethylene adipamide copolymer (polyamide 6/66), polyhexamethylene adipa And an amide / polyhexamethylene terephthalamide copolymer (polyamide 66 / 6T) and copolymers thereof. Two or more of these may be used.

  Of these, polyamide 6, polyamide 66, polyamide 610, polyamide 6/66 copolymer, and polyamide 66 / 6T copolymer are preferably used, and polyamide 6, polyamide 66, and polyamide 66 / 6T copolymer are particularly preferable in terms of mechanical properties and welding properties.

  The degree of polymerization of the polyamide resin (A), that is, the viscosity number measured according to ISO 307 using 96% sulfuric acid as a solvent is in the range of 100 to 180 ml / g in terms of mechanical properties and fluidity. From the viewpoint of toughness, welding strength and fluidity, those having a viscosity number of 120 to 160 ml / g are particularly preferable.

  The red polyamide resin composition used in the present invention contains 0.10 to 2.5 parts by weight of the inorganic pigment (B) with respect to 100 parts by weight of the polyamide resin (A). By containing the inorganic pigment (B), it is possible to suppress discoloration and fading of automobile underhood parts formed by molding the resin composition.

  As the inorganic pigment (B), for example, iron oxide (for example, iron oxide (III) such as Bengala, Malthread, etc.), red lead (lead trioxide, Mitsumetan), red such as molybdenum red, cadmium red, etc. An inorganic pigment is mentioned, You may contain 2 or more types of these. Of these inorganic pigments, iron oxides such as bengara (iron oxide (III) and the like) are particularly preferable.

  When the content ratio of the inorganic pigment (B) is less than 0.10 parts by weight, the effect of suppressing discoloration is not sufficiently obtained, and discoloration due to heat of the automobile underhood component increases, so the content ratio is 0.5. It is preferable that it is at least parts by weight. On the other hand, when the content ratio of the inorganic pigment (B) exceeds 2.5 parts by weight, the mechanical properties of the molded product are lowered, and the strength as an automobile underhood part becomes insufficient. The amount is preferably 0 part by weight or less.

  The red polyamide resin composition used in the present invention contains 0.10 to 0.50 parts by weight of the organic pigment (C) with respect to 100 parts by weight of the polyamide resin (A). By containing the organic pigment (C), the initial color developability of the molded product can be improved.

  Examples of organic pigments (C) include orange or red pigments [β-naphthol azo compounds such as Pigment Red 1,3,4,6,48,57: 1 (Red No. 202); Pigment Red 37, Pigment Pyrazolone azo compounds such as orange 13; perinone / perylene compounds (red pigments such as pigment red 178, 179, 190); anthraquinone compounds (pigment red 83, 177 etc.); quinacridone compounds (pigment red 202) Thioindigo; pigment red 88; hansa yellow; permanent red, lake red, watch chan red, brilliant carmine 6B; diketopyrrolopyrrole, etc.], purple pigment [quinacridone compounds (pigment violet 19 etc.); dioxazine compound (Pigment Violet 23); indirubin, etc.] and the like. Of these organic compounds, perinone / perylene compounds (eg, red pigments such as Pigment Red 178, 179 and 190) and quinacridone compounds (Pigment Red 202) are preferably used, and vivid red color developability for automotive underparts. Can be granted. Perinone / perylene compounds are more preferably used.

  When the content of the organic pigment (C) is less than 0.10 parts by weight, the red color developability of the molded product becomes insufficient, and the initial color developability of the automobile underfood component may be lowered. On the other hand, when the content ratio of the organic pigment (C) exceeds 0.50 parts by weight, the mechanical properties of the molded product are deteriorated, so that the strength as an automobile underhood component may be insufficient.

  The red polyamide resin composition may further contain a red dye or a non-red pigment if necessary. Examples of red dyes include orange dyes [azo dyes (such as Disperse Orange 3), condensed polycyclic quinone dyes (such as Vat Orange 3)], red dyes [azo dyes (such as Disperse Orange 3, Disperse Thread 1) Anthraquinone dyes (Disperse Red 11, 15, etc.), condensed polycyclic quinone dyes (But Orange 3 etc.), selenium dyes (Bat Red 23 etc.), perinone dyes etc.], purple dyes (Disperse Violet 1 etc.) Anthraquinone dyes; indigoid dyes such as vat violet 2). Non-red pigments include, for example, white pigments (titanium dioxide, zinc oxide, zinc sulfide, calcium carbonate, lithopone, etc.), extenders (calcium carbonate, barium sulfate, silica, aluminum hydroxide, kaolin clay, talc, bentonite, etc.) , Yellow pigment (titanium yellow, resurge, yellow lead, yellow iron oxide, cadmium yellow, zinc chromate, ocher (ocher), chenner, etc.), orange pigment (mals orange, etc.), brown pigment (mals brown, etc.), blue pigment ( Bitumen, ultramarine blue, cobalt blue (tenal blue, etc.), green pigments (chrome green, mars green, etc.), purple pigments (mals violet, etc.) and the like.

  The red polyamide resin composition may further contain an inorganic filler (D). By containing the inorganic filler, the mechanical strength of the molded product can be further improved, and a higher-strength automobile underhood component can be obtained. The content of the inorganic filler (D) is preferably 20 parts by weight or more with respect to 100 parts by weight of the polyamide resin (A), which is advantageous in that the mechanical strength can be further improved. On the other hand, 80 parts by weight or less is preferable with respect to 100 parts by weight of the polyamide resin (A), which is advantageous in that the fluidity of the resin composition can be kept high.

  The inorganic filler (D) is not particularly limited, and examples thereof include glass fibers, PAN-based and pitch-based carbon fibers, stainless steel fibers, aluminum fibers and brass fibers, gypsum fibers, ceramic fibers, asbestos fibers, Fibrous fillers such as zirconia fiber, alumina fiber, silica fiber, titanium oxide fiber, silicon carbide fiber, rock wool, potassium titanate whisker, silicon nitride whisker, glass beads, talc, mica, calcium carbonate, wollastonite, silica, etc. Granular fillers and other various fillers. From the viewpoint of mechanical properties, glass fibers, carbon fibers, glass beads, talc, and wollastonite are preferably used, and glass fibers are more preferably used.

  The surface of the inorganic filler (D) is preferably treated with a known coupling agent (for example, silane coupling agent, titanate coupling agent, etc.) or other surface treatment agent. This is advantageous in that excellent mechanical strength can be obtained.

  The red polyamide resin composition preferably further contains a copper compound, which is advantageous in that long-term heat resistance can be improved. Specific examples of the copper compound include cuprous chloride, cupric chloride, cupric bromide, cuprous iodide, cuprous iodide and other inorganic copper halide compounds, cupric sulfate, Cupric nitrate, copper phosphate, cuprous acetate, cupric acetate, cupric salicylate, cupric stearate, cupric benzoate and inorganic copper halide compounds and xylylenediamine, 2-mercapto Examples thereof include compounds with benzimidazole, benzimidazole and the like. Of these, monovalent inorganic copper halide compounds are preferred, and cuprous iodide is particularly preferred. In addition, the proportion of the copper compound is preferably 0.01 to 1 part by weight, particularly preferably 0.02 with respect to 100 parts by weight of the polyamide resin (A) in terms of heat resistance and coloring. -0.1 parts by weight. It is also possible to mix an alkali halide compound in a form used in combination with a copper compound. Examples of the alkali halide compound include lithium bromide, lithium iodide, potassium bromide, potassium iodide, sodium bromide and sodium iodide, and potassium iodide is particularly preferred.

  The red polyamide resin composition may further contain a polyhydric alcohol. The content ratio of the polyhydric alcohol is preferably 0.10 to 10 parts by weight, particularly preferably 1.0 to 5.5 parts by weight with respect to 100 parts by weight of the polyamide resin (A) in terms of heat resistance and coloring. 0 parts by weight.

  Specific examples of the polyhydric alcohol include glycerol, trimethylpropane, 2,3-di- (2′-hydroxy-ethyl) -cyclohexane-1-ol, hexane-1,2,6-triol, 1,1 , 1-tris- (hydroxymethyl) ethane, 3- (2′-hydroxyethoxy) -propane-1,2-diol, 3- (2′-hydroxypropoxy) -propane-1,2-diol, 2- (2′-hydroxyethoxy) -hexane-1,2-diol, 6- (2′-hydroxypropoxy) -hexane-1,2-diol, 1,1,1-tris-[(2′-hydroxyethoxy) -Methyl] -ethane, 1,1,1-tris-[(2'-hydroxypropoxy) -methyl] -propane, 1,1,1-tris- (4'-hydroxyphenyl) Ethane, 1,1,1- (hydroxyphenyl) -propane, 1,1,3-tris- (dihydroxy-3-methylphenyl) -propane, 1,1,4-tris- (dihydroxyphenyl) -butane, , 1,5-tris- (dihydroxyphenyl) -3-methylpentane, di-trimethylolpropane, trimethylolpropane ethoxylate or trimethylolpropane propoxylate, polyhydric alcohols (for example, pentaerythritol, dipentaerythritol, tripenta Erythritol) and monosaccharides (for example, cyclodextrin, D-mannose, glucose, lactose, sucrose, fructose, xylose, arabinose, D-mannitol, D-sorbitol, D- or L-arabitol, xylitol, y Tall, talitol, allitol, Alto triol, Guiritoru, erythritol, Suretoru, D- Guronikku -y- lactone) and the like. Of these, polyhydric alcohols are preferable, and dipentaerythritol is particularly preferable.

  In the red polyamide resin composition, other components such as antioxidants and heat stabilizers (hindered phenols, hydroquinones, phosphites, substitutes thereof, etc.), weather resistance, etc. are used within the range not impairing the effects of the present invention. Agents (resorcinol, salicylate, benzotriazole, benzophenone, hindered amine, etc.), mold release agents and lubricants (montanic acid and its metal salts, esters, half esters, stearyl alcohol, stearamide, various bisamides, bisureas) And polyethylene wax, etc.), crystal nucleating agents (talc, silica, kaolin, clay, etc.), plasticizers (octyl p-oxybenzoate, N-butylbenzenesulfonamide, etc.), antistatic agents (alkyl sulfate type anionic antistatic agents) Agent, polyoxyethylene sorbitan Nonionic antistatic agents such as stearates, betaine amphoteric antistatic agents, etc.), flame retardants (eg, red phosphorus, melamine cyanurate, magnesium hydroxide, aluminum hydroxide and other hydroxides, ammonium polyphosphate, bromine) Polystyrene, brominated polyphenylene ether, brominated polycarbonate, brominated epoxy resin or a combination of these brominated flame retardants and antimony trioxide), and other polymers.

  Next, a method for obtaining a red polyamide resin composition will be described with an example. There is no restriction | limiting in particular in the manufacturing method of a red polyamide resin composition, For example, each component can be obtained by melt-kneading by a well-known kneading method. The treatment method may be either a batch type or a continuous type, but the continuous type is preferred from the viewpoint of productivity. There is no restriction | limiting also in a concrete kneading apparatus, For example, a single screw or a twin screw extruder, a kneader, a kneader etc. are mentioned, Especially a twin screw extruder is preferable in terms of productivity. Although there is no restriction | limiting in particular also in screw arrangement, It is preferable to provide a kneading zone in order to disperse | distribute each component more uniformly. When using an extruder, (i) a method of supplying each raw material to the extruder at once, or (ii) a plurality of arbitrary components are previously melt-kneaded and pelletized, and the remaining components are extruded into the extruder. And (iii) when an extruder having two or more supply ports is used, any or a plurality of components are supplied from the first (upstream) supply port, and the second A method of supplying the remaining arbitrary or plural components from the subsequent (downstream) supply ports can also be employed. From the viewpoint of productivity, the method (iii) is preferable. In particular, when the inorganic filler (D) is contained, a polyamide resin, an inorganic pigment, an organic pigment and, if necessary, a copper compound are supplied from the first supply port by the method (iii), and melt-kneaded in advance. In addition, the method of supplying the inorganic filler from the second supply port is preferable in terms of dispersibility of each component, mechanical characteristics, and the like. After melt-kneading, it is discharged into a strand shape, cut into pellets by water cooling, and a red polyamide resin composition pellet can be obtained.

Next, automobile underhood parts will be described. The automobile underhood component of the present invention is a molded product formed by molding the red polyamide resin composition, and the color space coordinate value in the CIE 1976 (L ^* , a ^* , b ^* ) color system is L ^*. The relations ≧ 26, a ^* ≧ 32, and b ^* ≧ 22 are satisfied.

L ^* , a ^* and b ^* can be measured by, for example, a color difference meter (color difference meter SM-5 manufactured by Suga Test Instruments). L ^* represents brightness, white is 100, and black is 0. a ^* and b ^* represent saturation ^. The plus side of a ^* represents red, the minus side represents green, the plus side of b ^* represents yellow, and the minus side represents blue. When a ^* is set as the X-axis and b ^* is set as the Y-axis, (a ^* , b ^* ) = (0, 0) means an achromatic color and is preferable because the saturation increases as the distance from the origin increases. Since automobile underhood parts express vivid colors, it is necessary to satisfy the relationship of L ^* ≧ 26, a ^* ≧ 32, and b ^* ≧ 22.

It is preferable that the color change ΔE after the automobile underhood component is held at 120 ° C. for 1000 hours is 5 or less. The color change ΔE is determined by, for example, heating an automobile under hood component at 120 ° C. for 1000 hours using an oven or the like, then obtaining L ^* , a ^*, and b ^* by the above method, and ΔE = ((ΔL ^* )) ² + (Δa ^* ) ² + (Δb ^* ) ² ) ^0.5 can be obtained. Here, ΔL ^* , Δa ^*, and Δb ^* represent changes in L ^* , a ^*, and b ^* before and after heat treatment, respectively. If ΔE is 5 or less, discoloration over time can be suppressed even when strongly influenced by heat.

In addition, for the measurement of the color space coordinate value and the color tone change ΔE in the CIE 1976 (L ^* , a ^* , b ^* ) color system, the conditions under which a red polyamide resin composition is molded into an automobile underhood part are schematically shown. It can also be measured by using a test piece formed under the same conditions as those described above.

  The automobile underhood parts refer to products represented by, for example, an engine cover, a radiator tank, an intake manifold, an engine mount, and the like under the hood of the automobile. Because it is used in a high-temperature environment, it is a component that tends to discolor from yellow to brown, but by using the above-mentioned red polyamide resin composition, it develops a vivid red color at the beginning and further discolors due to heat. Therefore, it is possible to obtain an automotive underhood component having excellent design properties that satisfies the above range.

  A known method can be used as a method of forming an automobile underhood part. Examples include extrusion molding, injection molding, injection compression molding, blow molding, press molding, and the like, and are not particularly limited, but injection molding is preferable from the viewpoint of productivity. The obtained molded product may be subjected to processing such as vibration welding, ultrasonic welding, spin welding, and laser welding.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited by a following example.

(Examples 1-3, Comparative Examples 1-9)
(1) Raw materials (A) Polyamide 6: CM1010 (manufactured by Toray Industries, Inc.), viscosity number 135 ml / g
(B) Red inorganic pigment (Bengara): Pigment Red 101 (manufactured by Toda Kogyo)
(C) Red organic pigment (perinone / perylene compound): Pigment Red 178 (manufactured by BASF)
Red dye: Solvent Red 179 (Nippon Kayaku)
(D) Inorganic filler: Glass fiber (fiber diameter 13 μm, T289 manufactured by Nippon Electric Glass Co., Ltd.)

(2) Compound The necessary ingredients except the inorganic filler (D) were mixed in advance with the composition shown in Table 1 to obtain a blend material. The blend material was supplied to the extruder (ZSK57 manufactured by Werner-Pfleiderer) from the first supply port, and the inorganic filler (D) was supplied from the second supply port, melt-kneaded, and pelletized.

(3) Molding The obtained pellets were molded with an S-2000i molding machine manufactured by FANUC in accordance with ISO1874-2.

  Further, a reduced molded product (approximate size 300 × 300 mm, wall thickness 3 mm) imitating an engine cover was molded using a J220EII-2M molding machine manufactured by Nippon Steel Works.

(4) Physical property evaluation Using the test piece for evaluation prepared in the above (3), the tensile strength was measured according to ISO527-1 and -2, and the Charpy impact strength was measured according to ISO179.

(5) Color tone evaluation About the test piece for evaluation immediately after molding produced in the above (3), L ^* , a ^* and b ^* were measured using a color difference meter (color difference meter SM-5 manufactured by Suga Test Instruments). Next, the evaluation test piece immediately after molding was subjected to a dry heat treatment at 120 ° C. for 1000 hours using a gear oven PHH-201M manufactured by ESPEC, and then L ^* , a ^* and b ^* were measured in the same manner before and after the dry heat treatment. ΔE = ((ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ) ^0.5 was determined. Here, ΔL ^* , Δa ^*, and Δb ^* represent changes in L ^* , a ^*, and b ^* before and after heat treatment, respectively.

(6) Appearance evaluation The reduced color molded product imitating the engine cover produced in the above (3) was visually observed for color tone after being processed at 120 ° C. for 1000 hours using a gear oven PHH-201M manufactured by ESPEC, Excellent ones were marked with ○, inferior ones with ×, and middle ones with Δ.

  The evaluation results of Examples 1 to 3 and Comparative Examples 1 to 9 are shown in Table 1.

The automobile underhood component according to the present invention can be widely used as an automobile underhood component that requires excellent color development.

Claims (5)

The inorganic pigment (B) is contained at a ratio of 0.10 to 2.5 parts by weight and the organic pigment (C) is 0.10 to 0.50 parts by weight with respect to 100 parts by weight of the polyamide resin (A). And a color space coordinate value in the CIE 1976 (L ^* , a ^* , b ^* ) notation is L ^* ≧ 26, a ^* ≧ 32, and b ^*. An automotive underhood component characterized by satisfying a relationship of ≧ 22.   The automobile underhood component according to claim 1, wherein the red polyamide resin composition contains the inorganic filler (D) in a proportion of 20 to 80 parts by weight.   The automobile underhood part according to claim 1 or 2, wherein the inorganic pigment (B) contains bengara.   The automobile underhood component according to any one of claims 1 to 3, wherein the organic pigment (C) contains a perinone / perylene compound. The automobile underhood component according to any one of claims 1 to 4, wherein a color tone change ΔE ^* after holding at 120 ° C for 1000 hours is 5 or less.