JP3834925B2 - Molding material for automotive lamp housing and automotive lamp housing parts - Google Patents

Description

【００５４】
【表２】

【００５５】
表１，２より、本発明の組成範囲内の成形材料よりなる自動車用ランプハウジングであれば、耐衝撃性、耐熱性、耐溶剤性、耐候性、二次加工性、レンズ溶着性に優れることが明らかである。
【００５６】
【発明の効果】
以上詳述した通り、本発明の自動車用ランプハウジングの成形材料及び自動車用ランプハウジング部品によれば、耐熱性、耐溶剤性、耐候性、レンズとハウジングとの溶着性、二次加工性に優れた自動車用ランプハウジングが提供される。[0001]
BACKGROUND OF THE INVENTION
The present invention is an automotive lamp having excellent heat resistance, solvent resistance, weather resistance, excellent weldability between a lens and a housing, and good secondary workability such as coating, plating, vapor deposition, and sputtering on the housing. The present invention relates to a molding material for a housing and a lamp housing part for an automobile.
[0002]
[Prior art]
Conventionally, in an automotive lamp housing, as an assembling method of the lamp housing and the lens, there are melt bonding, hot plate welding, vibration welding, ultrasonic welding, and the like. Among these, the melt bonding method employs talc-containing polypropylene as a housing material in consideration of cost, solvent resistance, weather resistance, etc., but this melt bonding method is a problem of water leakage due to the construction method. Therefore, in recent years, there is a tendency for the adoption of a welding method using heat-resistant ABS, AES, AAS resin, or the like as a housing material to increase.
[0003]
On the other hand, there are two types of automotive lamp housings that are subjected to secondary processing such as painting, plating, vapor deposition, sputtering, etc. on the design, and in the former case, the secondary processing is easy. However, in the latter case, the weather resistance is required for the resin material itself constituting the housing.
[0004]
In addition, in the automotive lamp, due to the recent high output and downsizing, the temperature in the lamp tends to be higher, and the resin material constituting the housing is required to have higher heat resistance. ing. In addition, there is a demand for improved solvent resistance against gasoline and the like.
[0005]
However, when a styrene resin such as heat resistant ABS, AES, or AAS resin is used as the housing material, the required characteristics cannot be sufficiently satisfied with respect to heat resistance, impact resistance, and the like.
[0006]
As for the purpose of improving heat resistance, impact resistance and the like, JP-A-60-212450 discloses a graft copolymer to a styrene-maleimide copolymer and a rubbery polymer, or an aromatic polycarbonate, etc. A housing material made of a resin composition in which is mixed is described.
[0007]
Japanese Patent Publication No. 3-80818 discloses a resin composition having improved resistance to environmental stress cracking, in which an acrylate ester homopolymer or a copolymer thereof, a rubber-containing styrenic resin and a polycarbonate are mixed. A resin composition is described.
[0008]
[Problems to be solved by the invention]
However, although the resin composition described in JP-A-60-212450 has improved heat resistance and impact resistance, it has a problem in solvent resistance due to the aromatic polycarbonate. When butadiene or the like is used alone as the rubbery polymer, there is a drawback that it is inferior in weather resistance.
[0009]
In addition, in the wide composition range disclosed in Japanese Patent Publication No. 3-80818, good results can be obtained in environmental stress cracking resistance. However, when a molding material for housing is used, the weldability between the lens and the housing is not satisfactory. A sufficient range is included. Therefore, the lamp housing using this resin composition has a drawback that the possibility of peeling at the joint portion with the lens is extremely high, and water leakage in the lamp may occur.
[0010]
The present invention solves the above-mentioned conventional problems, is excellent in heat resistance, solvent resistance, and weather resistance, and is excellent in weldability between the housing and the lens, and secondary workability of the housing (painting, plating, vapor deposition) The object is to provide a molding material for an automotive lamp housing and an automotive lamp housing component which are excellent in sputtering and the like.
[0011]
[Means for Solving the Problems]
The molding material of the automotive lamp housing of the present invention comprises 30 to 65 parts by weight of an aromatic polycarbonate (a), an aromatic vinyl monomer and a vinyl cyanide monomer in a rubber component containing an acrylic ester polymer. 5 to 40 parts by weight of a copolymer (b) in which the content of an acrylic ester polymer in the copolymer is 30 to 70% by weight, and an aromatic polymer It is characterized by comprising a thermoplastic resin containing 20 to 50 parts by weight of a copolymer (c) obtained by copolymerizing a vinyl monomer and a vinyl cyanide monomer.
[0012]
The total amount of the aromatic polycarbonate (a), the rubbery polymer (b) and the copolymer (c) is 100 parts by weight.
[0013]
The automotive lamp housing component of the present invention is formed by molding such a molding material for an automotive lamp housing.
[0014]
If it is a resin composition in which a rubber-like polymer (b) containing an aromatic polycarbonate (a) and an acrylate-based rubber and a copolymer (c) are blended within a predetermined range, the moldability, Excellent heat resistance, solvent resistance, weather resistance, secondary workability such as painting, plating, vapor deposition, sputtering, etc. and high compatibility with the lens, so it has excellent weldability between the housing and the lens. Lamp housing for automobiles excellent in performance, solvent resistance, weather resistance, weldability between lens and housing, and secondary workability.
[0015]
The copolymer (c) may be a copolymer of an aromatic vinyl monomer, a vinyl cyanide monomer, and other monomers copolymerizable therewith.
[0016]
The molding material of the present invention further contains a rubbery polymer (d) obtained by grafting an aromatic vinyl monomer and a vinyl cyanide monomer to a rubber component other than the acrylate polymer. May be.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0018]
The aromatic polycarbonate constituting the thermoplastic resin according to the present invention is not particularly limited, and an aromatic polycarbonate using 2,2-bis- (4-oxyphenyl) propane which is easily available as a raw material is suitable. .
[0019]
The rubber-like polymer (b) according to the present invention is composed of a continuous phase composed of a glassy polymer in which a rubber component is dispersed in the form of particles and a part of the rubber-dispersed particles is chemically bonded. Is.
[0020]
Examples of the rubber component of the rubbery polymer (b) include butadiene, a butadiene polymer, a copolymer of a vinyl monomer copolymerizable with butadiene, an acrylate polymer, and an acrylate polymer. Examples thereof include a copolymer with a copolymerizable vinyl monomer, ethylene-propylene or butene-nonconjugated diene copolymer, etc. In the present invention, the rubbery polymer (b) is methyl acrylate, ethyl acrylate. Acrylate polymers such as n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-methylpentyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate An essential ingredient such as acrylic Containing 30 to 70 wt% in the copolymer ester-based polymer (b). When the content of the acrylic ester polymer is less than 30% by weight, the impact strength of the obtained molded product is inferior, and when it exceeds 70% by weight, the heat resistance is inferior. In the present invention, as the rubbery polymer, a rubbery polymer obtained by grafting an aromatic vinyl monomer and a vinyl cyanide monomer to the rubber component as described above other than the acrylic ester polymer. (D) may be contained.
[0021]
As the aromatic vinyl monomer constituting the rubber-like polymer (b), the rubber-like polymer (d) and the copolymer (c), styrene, α-methylstyrene, or a mixture thereof is preferably used. In addition to these, p-methylstyrene, halogenated styrene and the like can be used as necessary. As the vinyl cyanide monomer, acrylonitrile, methacrylonitrile, or a mixture thereof may be used, and acrylonitrile is particularly preferable.
[0022]
Examples of other copolymerizable monomers used as necessary in the copolymer (c) include maleimide compounds, such as N-methylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide, and the like. N-phenylmaleimide is particularly preferable.
[0023]
In the present invention, suitable blending compositions of the rubber-like polymer (b), the copolymer (c) and the rubber-like polymer (d) are as follows.
[0024]
Rubbery polymer (b) (wt%)
Acrylic acid ester polymer: 30-70
Rubber components other than acrylic ester polymers: 0 to 36
Aromatic vinyl monomer: 15-40
Vinyl cyanide monomer: 5-30
Copolymer (c) (wt%)
Aromatic vinyl monomer: 50-80
Vinyl cyanide monomer: 15-35
Other monomers such as maleimide compounds: 0-30
Rubbery polymer (d) (wt%)
Rubber components other than acrylic ester polymers: 30 to 70
Aromatic vinyl monomer: 15-40
Vinyl cyanide monomer: 5-30
The molding material of the present invention contains these polymers in the following proportions (however, the total amount is 100 parts by weight).
[0025]
Aromatic polycarbonate (a): 30 to 65 parts by weight Rubber polymer (b): 5 to 40 parts by weight Copolymer (c): 20 to 50 parts by weight Rubber polymer (d): 0 to 36 parts by weight When the rubber-like polymer (d) is contained, the total amount of the rubber-like polymer (b) and the rubber-like polymer (d) is preferably in the range of 5 to 40 parts by weight.
[0026]
In the present invention, when the content of the aromatic polycarbonate is less than 30 parts by weight, the resulting molded article has poor impact resistance, and when it is more than 65 parts by weight, the moldability and solvent resistance are lowered.
[0027]
Moreover, when the content of the rubber-like polymer (b) is less than 5 parts by weight, the solvent resistance of the obtained molded product is inferior, and when it exceeds 40 parts by weight, the heat resistance is inferior.
[0028]
If the content of the copolymer (c) is less than 20 parts by weight, the compatibility between the polycarbonate (a) and the rubber-like polymer (b) is lowered, and not only the solvent resistance but also various physical properties are lowered. If the amount exceeds 50 parts by weight, the impact resistance is lowered.
[0029]
When rubber-like polymer (d) is blended, butadiene or the like is used as its rubber component, so that paintability and plating properties are maintained, and weather resistance is maintained by using ethylene-propylene-nonconjugated diene rubber. However, the paintability can be further improved. However, if this ratio exceeds 36 parts by weight, the weather resistance is lowered when the rubber component is butadiene, and the solvent resistance is lowered when the rubber component is an ethylene-propylene-nonconjugated diene rubber. The coalescence (d) is 36 parts by weight or less.
[0030]
In addition, there is no restriction | limiting in particular in the manufacturing method of the rubber-like polymer and copolymer which concern on this invention, Any generally well-known polymerization techniques, such as suspension polymerization, emulsion polymerization, block polymerization, and solution polymerization, are employable. .
[0031]
The molding material of the present invention comprises an aromatic polycarbonate (a) and a rubber-like polymer (b), a copolymer (c) and, if necessary, a rubber-like polymer (d) together with ordinary kneading means such as extrusion. It can be obtained by uniformly kneading using a machine, a Banbury mixer or the like.
[0032]
In addition, the molding material of this invention may contain additives, such as a stabilizer, a plasticizer, a ultraviolet absorber, and a pigment, in the range which does not impair the characteristic.
[0033]
Representative molded products of the automotive lamp housing parts of the present invention include automotive headlamp cases, headlamp doors, position lamp cases, reflectors, back lamp cases, brake lamp cases, etc., and automotive lamp housings of the present invention. It is easily molded in accordance with a conventional method using a molding material.
[0034]
【Example】
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to synthesis examples, examples, and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In the examples, “parts” means “parts by weight”.
[0035]
Synthesis Example 1: Production of rubber-like polymer (b-1) An AAS rubber-like polymer was synthesized by an emulsion polymerization method with the following composition.
[0036]
[Combination]
Styrene 30 parts Acrylonitrile 15 parts Polybutyl butyl 55 parts Disproportionated potassium rosin acid 1 part Potassium hydroxide 0.03 parts t-Dodecyl mercaptan 0.1 part Cumene hydroperoxide 0.3 parts Ferrous sulfate 0.007 Part Sodium pyrophosphate 0.1 part Crystal glucose 0.3 part Distilled water 190 parts Autoclave is charged with distilled water, disproportionated potassium rosinate, potassium hydroxide and polybutyl acrylate latex (solid content) at 60 ° C After heating, ferrous sulfate, sodium pyrophosphate and crystalline glucose were added, and styrene, acrylonitrile, t-dodecyl mercaptan and cumene hydroperoxide were continuously added over 2 hours while maintaining the temperature at 60 ° C. The temperature was raised and maintained for 1 hour to complete the reaction. An antioxidant was added to the AAS latex obtained by this reaction, then coagulated with sulfuric acid, sufficiently washed with water, and dried to obtain an AAS graft copolymer.
[0037]
Synthesis Example 2: Production of rubber-like polymer (b-2) Same as Synthesis Example 1 except that 25 parts of acrylonitrile and 60 parts of styrene were reacted in the presence of 15 parts of polybutyl acrylate latex (solid content) Thus, an AAS graft copolymer was obtained.
[0038]
Synthesis Example 3: Production of rubber-like polymer (b-3) Same as Synthesis Example 1, except that 5 parts of acrylonitrile and 15 parts of styrene were reacted in the presence of 80 parts of polybutyl acrylate latex (solid content) Thus, an AAS graft copolymer was obtained.
[0039]
Synthesis Example 4: Production of copolymer (c-1) 120 parts of water, 0.002 part of sodium alkylbenzene sulfonate, 0.5 part of polyvinyl alcohol, 0.3 part of azoisobutylnitrile, and acrylonitrile in a nitrogen-substituted reactor A vinyl monomer mixture consisting of 30 parts and 70 parts of styrene was added, heated to 60 ° C. for 5 hours, heated to 120 ° C., reacted for 4 hours, and the polymer was taken out. The conversion rate was 98%.
[0040]
Synthesis Example 5: Production of copolymer (c-2) 15 parts by weight of methyl methacrylate in water using styrene as a fatty acid salt, lauryl peroxide as a polymerization initiator, dodecyl lucaptan as a chain transfer agent, styrene 25 parts, 15 parts of α-methylstyrene, 25 parts of acrylonitrile and 20 parts of N-phenylmaleimide were polymerized by a known emulsion polymerization method to obtain a copolymer.
[0041]
Synthesis Example 6: Production of rubber-like polymer (d-1) 70 parts (solid content) of ethylene propylene non-conjugated diene copolymer rubber latex (ethylene: propylene = 75: 25 (parts)) having a gel content of 65% by weight AES graft copolymer was obtained in the same manner as in Synthesis Example 1, except that 30 parts of a vinyl monomer mixture composed of 70% by weight of styrene and 30% by weight of acrylonitrile was made 100 parts in total.
[0042]
Synthesis Example 7: Production of rubber-like polymer (d-2) An ABS graft copolymer was prepared in the same manner as in Synthesis Example 1 except that 15 parts of acrylonitrile and 35 parts of styrene were reacted in the presence of 50 parts of polybutadiene latex. Obtained.
[0043]
Examples 1-6, Comparative Examples 1-9
Polymer synthesized in the above synthesis example using “Panlite-1250”: aromatic polycarbonate resin made from 2,2-bis- (4-oxyphenyl) propane as a raw material as polycarbonate (a) Were mixed in the formulation shown in Tables 1 and 2, kneaded with a Banbury mixer, and then pelletized.
[0044]
Using the obtained pellets, a headlamp case having a length × width × depth of 100 mm × 220 mm × 150 mm was formed and evaluated by the following method.
[0045]
(1) Falling ball impact test A 1 Kg hard ball was dropped from a height of 1 m onto each corner of the housing and observed for cracking, and evaluated according to the following criteria.
[0046]
Evaluation Criteria ◎ No crack at all ○ No crack, but whitening or deformation × One or more cracks ▲ 2 ▼ Heat deformation test The housing is left in an oven at 150 ° C for 2 hours, its deformation amount is obtained, and its deformation rate Of less than 1% was judged as good (◯), and over 1% was judged as bad (x).
[0047]
(3) Cut out the long side (horizontal side) of the solvent-resistant housing, fix it to a jig that applies distortion, apply Toyota brake fluid (Toyota genuine DOT4), change the curvature of the distortion, and cause a destruction phenomenon The curvature was defined as the critical strain, and the evaluation was performed according to the following criteria depending on the magnitude of the critical strain.
[0048]
Evaluation criteria ◎ Limit strain 0.7% or more ○ Limit strain 0.5% to 0.7%
X Limit strain Less than 0.5% (4) The weatherproof housing was left in a sunshine weatherometer and subjected to an accelerated weather resistance test under the following conditions, and evaluated according to the following criteria depending on the degree of discoloration.
[0049]
Test conditions Acceleration time: 2000 hours Acceleration condition: 63 ± 3 ° C
Spray: 18 minutes out of 120 minutes
Evaluation criteria ◎ ΔE ≦ 2
○ 2 <ΔE <5
× 5 ≦ ΔE
▲ 5 ▼ Secondary workability (paintability, plating characteristics)
Cut out the long side (horizontal side) of the housing, paint and plate by the usual methods, peel off with a cellophane tape that is generally available, check the adhesion, and evaluate the peeling condition according to the following criteria did.
[0050]
Evaluation Criteria ◎ No peeling ○ Slightly peeling × Completely peeling (6) A hot plate weldable housing was placed on a hot plate at 220 ° C., and the housing was instantaneously bonded to the lens in a molten state. This joint portion was cut out and peeled off by pulling with a constant load of 10 kg / cm ² peeling conditions, and the peeling state was evaluated according to the following criteria.
[0051]
Evaluation criteria ◎ No peeling ○ Slightly peeling × Completely peeling ▲ 7 ▼ Vibration weldability The housing and lens are welded by vibration, this joint is cut out, and peeling by pulling, constant load of 10 kg / cm ² peeling condition The peeling condition was evaluated according to the following criteria.
[0052]
Evaluation criteria ◎ No peeling ○ Slight peeling × Completely peeling results are shown in Tables 1 and 2.
[0053]
[Table 1]

[0054]
[Table 2]

[0055]
From Tables 1 and 2, if the automotive lamp housing is made of a molding material within the composition range of the present invention, it is excellent in impact resistance, heat resistance, solvent resistance, weather resistance, secondary workability, and lens weldability. Is clear.
[0056]
【The invention's effect】
As described above in detail, according to the molding material of the automotive lamp housing and the automotive lamp housing component of the present invention, the heat resistance, the solvent resistance, the weather resistance, the weldability between the lens and the housing, and the secondary workability are excellent. An automotive lamp housing is provided.

Claims (5)

30 to 65 parts by weight of aromatic polycarbonate (a),
A rubbery polymer obtained by grafting an aromatic vinyl monomer and a vinyl cyanide monomer to a rubber component containing an acrylate ester polymer, wherein the acrylate ester polymer in the copolymer 5 to 40 parts by weight of copolymer (b) having a content of 30 to 70% by weight;
Copolymer obtained by copolymerizing aromatic vinyl monomer and vinyl cyanide monomer (c)
A molding material for an automotive lamp housing, comprising a thermoplastic resin containing 20 to 50 parts by weight. The copolymer (c) according to claim 1, wherein the copolymer (c) is a copolymer of an aromatic vinyl monomer, a vinyl cyanide monomer, and another monomer copolymerizable therewith. Molding material for automotive lamp housing. 3. The molding material according to claim 1, wherein the molding material further contains a rubbery polymer (d) obtained by grafting an aromatic vinyl monomer and a vinyl cyanide monomer to a rubber component other than the acrylate polymer. A molding material for a lamp housing for an automobile. An automotive lamp housing part formed by molding the molding material of the automotive lamp housing according to any one of claims 1 to 3. 5. The automotive lamp housing part according to claim 4, wherein the lamp housing part is an automotive head lamp case, a position lamp case, a back lamp case, a brake lamp case, or a reflector.