JP5149030B2 - Transparent material for vehicle lamp and vehicle lamp using the same - Google Patents

Description

  The present invention relates to a transparent material for a vehicle lamp and a vehicle lamp using the same, and in particular, a transparent such as a headlight, a taillight, and a lens incorporated in another lamp used in a four-wheeled vehicle, a two-wheeled vehicle, and other vehicles. The present invention relates to a transparent material that is suitably used for parts and is lightweight and excellent in weather resistance and light resistance, and a vehicle lamp using the transparent material.

  Such a vehicular lamp is mainly attached to a lamp body formed in a container shape having an open front surface, a lamp unit attached to the lamp body and having a light source (lamp), and a front opening of the lamp body. It is composed of a lens (outer lens) as a lamp cover.

  Conventionally, resins such as polymethyl methacrylate (PMMA) and polycarbonate (PC) have been used as materials for such lamp covers (see Patent Documents 1 to 4).

  However, PMMA is excellent in light transmittance, weather resistance, and light resistance, but has disadvantages that are inferior in mechanical strength, chemical resistance, and light weight, and PC is excellent in heat resistance and impact resistance. However, since the specific gravity is large, it is heavy and the transmittance of ultraviolet rays is as low as 60% or less, so that in addition to weather resistance and light resistance, there is a problem that light transmittance is inferior.

  For this reason, as a material that is lightweight and excellent in weather resistance and light resistance, a polymer obtained by ring-opening polymerization of a cyclic olefin and then hydrogenating has been proposed (see Patent Documents 5 to 7). However, it has not been able to fully meet the market demands in recent years. That is, in recent years, market demands have become more and more severe, and the use of HID (High Intensity Discharge) lamps has demanded further improvement in weather resistance and light resistance, and further weight reduction to improve fuel consumption. Under the circumstances, the cyclic olefin-based polymer described in Patent Document 5 and the like can sufficiently meet the demand for further weight reduction, although the weight, weather resistance, and light resistance are improved as compared with PC. I didn't get it. In addition, the cyclic olefin polymer described in Patent Document 5 and the like has insufficient weather resistance and light resistance due to a large amount of tertiary carbon in the polymer skeleton.

JP-A-7-282602 JP 2001-266617 A Japanese Patent Laid-Open No. 10-305453 Japanese Patent Laid-Open No. 11-39910 JP 11-339520 A JP 2000-48608 A JP 2004-296281 A

  Here, the present invention has been made against the background of such circumstances, and the problem to be solved is to provide a transparent material for vehicle lighting that has high heat resistance, weather resistance and light resistance, and is lighter. In particular, another object is to provide a useful vehicle lamp using such a transparent material.

  As a result of intensive investigations to solve such problems, the present inventors have advantageously obtained the desired transparent material for vehicle lamps and vehicle lamps by using a predetermined β-pinene polymer. The inventors have found that the present invention can be obtained and have completed the present invention.

  That is, the present invention provides a transparent material for vehicle lamps characterized by comprising a β-pinene polymer having a specific gravity of 0.85 or more and less than 1.0 and a glass transition temperature of 100 ° C. or more. The gist.

  According to one of the desirable embodiments of the transparent material for vehicle lighting according to the present invention, the β-pinene polymer is hydrogenated and ([hydrogenated olefin The number of ionic double bonds] / [number of olefinic double bonds in the polymer before hydrogenation]) × 100 is 95% or more.

  Moreover, the gist of the present invention is also a vehicle lamp characterized by using the transparent material as described above.

Thus, in the vehicle lamp transparent material according to the present invention and the vehicle lamp using the same, since the predetermined β-pinene polymer is used as the forming material, the β-pinene polymer is used. Due to the excellent characteristics of the following effects can be obtained.
(1) Since the β-pinene polymer used as a material for forming a transparent material for a vehicle lamp is a polymer having a low specific gravity, the weight of the target transparent material for a vehicle lamp, and thus the vehicle lamp, can be effectively reduced. It is possible to reduce the weight.
(2) Since such β-pinene polymer has high heat resistance and low water absorption, it is effective for the transparent material for vehicle lamps to be deformed by the heat of the light source or to be deformed by the adsorption / desorption of water. Can be prevented.
(3) Since the transparent material for vehicle lighting according to the present invention has a high balance between elastic modulus and impact resistance, it is possible to advantageously reduce the thickness of the intended vehicle lighting.
(4) Since the transparent material for vehicle lighting according to the present invention has a low water vapor transmission rate, it is possible to effectively suppress the occurrence of problems due to condensation inside the vehicle lighting.
(5) The transparent material for vehicle lamps according to the present invention has a feature that no harmful gas is generated even if it is discarded and then incinerated.
(6) Since the β-pinene polymer used in the present invention has a low melt viscosity with respect to the molecular weight, it is possible to obtain a transparent material for a vehicle lamp in which a finer surface pattern is formed.
(7) Since the transparent material for vehicle lighting according to the present invention has high transparency, it is possible to increase the light use efficiency.
(8) Since the transparent material for vehicle lamps according to the present invention has high weather resistance and light resistance, it has an advantage that the performance is not deteriorated when used for a long time.
(9) Since the β-pinene polymer used in the present invention can be obtained from a raw material derived from a natural product, it is a carbon neutral material and has environmentally friendly characteristics.

  By the way, the β-pinene polymer used as a transparent material for vehicle lamps in the present invention has a specific gravity of 0.85 or more and less than 1.0 and a glass transition temperature of 100 ° C. or more. It is a coalescence. Here, the β-pinene polymer in the present specification and claims refers to a polymer (polymer) having a β-pinene content of 50% by mass or more. In the transparent material for vehicle lighting according to the present invention, a β-pinene polymer having a β-pinene content of 60% by mass or more is advantageously used, and more preferably, the β-pinene content is 70% by mass. The above β-pinene polymer is used.

  As the β-pinene used as a raw material for producing such β-pinene polymer, any conventionally known one can be used. For example, it is possible to use a terpene such as α-pinene collected from a plant or a petroleum-derived compound, as well as it can be directly used after purification from a plant such as pine or citrus. Β-pinene and the like produced according to a more known technique (for example, the technique disclosed in US Pat. No. 3,278,623) can also be used. The β-pinene polymer obtained using such plant-derived β-pinene is a carbon-neutral material. In this respect, the transparent material for vehicle lamps according to the present invention is a It can contribute to the prevention of global warming.

  Further, the β-pinene polymer used in the present invention may be a homopolymer of the above-described β-pinene, or at least one kind of other copolymerizable monomers with β-pinene. There is no problem even if it is a copolymer of. Examples of monomers copolymerizable with β-pinene include cationic polymerizable monomers, radical polymerizable monomers, coordination polymerizable monomers, and plant-derived terpenes.

  In the present invention, the cationically polymerizable monomer, radically polymerizable monomer, and coordination polymerizable monomer that are used when producing the β-pinene polymer are generally used conventionally. It is possible to use what is. Plant-derived terpenes can also be used as the polymerizable monomer in any of the cationic polymerization method, radical polymerization method and coordination polymerization method. Specifically, as the cationic polymerizable monomer, isobutylene, isoprene, butadiene, styrene, α-methylstyrene, p-methylstyrene, p-methoxystyrene, pt-butoxystyrene, indene, alkyl vinyl ether, norbornene Further, as the radical polymerizable monomer, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate (Meth) acrylates such as 2-hydroxypropyl (meth) acrylate and glycidyl (meth) acrylate; nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile; amide group-containing vinyl monomers such as acrylamide and methacrylamide Chromatography; vinyl acetate, vinyl pivalate, vinyl esters such as vinyl benzoate, vinyl chloride, vinylidene chloride, maleic anhydride, maleic acid, fumaric acid, fumaric acid esters, may be mentioned maleimide. Examples of coordination polymerizable monomers include ethylene, propylene, 1-hexene, cyclopentene, norbornene, and plant-derived terpenes include myrcene, alloocimene, omecine, α-pinene. , Dipentene, limonene, α-ferrandrene, α-terpinene, γ-terpinene, 2-carene, 3-carene and the like. Among these, one or more types are appropriately selected and used according to the amount of β-pinene used. Since the β-pinene polymer is advantageously obtained by the cationic polymerization method, among the polymerizable monomers as described above, the cationic polymerizable monomer is particularly advantageously used.

  In the case where the copolymerizable monomer is copolymerized with β-pinene, the amount of copolymerization is preferably 0.001 to 50% by mass in the polymer, and more preferably 0.01 to 20% by mass. Preferably, 0.05-10 mass% is the most preferable. If the amount of copolymerization is too large, problems such as increased water absorption and reduced heat resistance are undesirable.

  On the other hand, a small amount of bifunctional or higher crosslinkable monomer (hereinafter referred to as a crosslinkable monomer) is copolymerized together with or in place of the above copolymerizable monomer. You can also Such a crosslinkable monomer is generally used as a branching agent or a crosslinking agent in the production of a polymer, but has a so-called long chain branching structure by reducing the amount used. A β-pinene polymer having a molecular weight that does not cause an insoluble part in an organic solvent is advantageously obtained. Specific examples of the crosslinkable monomer that can be used in the present invention include m-diisopropenylbenzene, p-diisopropenylbenzene, m-divinylbenzene, p-divinylbenzene, and 1,4-cyclohexanedimethanoldi. Bifunctional vinyl compounds such as vinyl ether and ethylene glycol divinyl ether can be mentioned, and among them, m-diisopropenylbenzene is preferably used from the viewpoints of economy and reactivity.

  When such a crosslinkable monomer is copolymerized with β-pinene (and a monomer copolymerizable with β-pinene), the copolymerization amount is 0.001 to 7% by mass in the polymer. Among them, 0.01 to 5% by mass is more preferable, and 0.05 to 4% by mass is most preferable. If the amount of copolymerization is too large, the resulting β-pinene polymer becomes gel and loses thermoplasticity, which is not preferable.

  By the way, the polymerization method of the β-pinene polymer used in the present invention is not particularly limited, and a known polymerization method suitable for the polymerizable monomer can be appropriately selected. For example, any one of an anionic polymerization method, a cationic polymerization method, a radical polymerization method and a coordination polymerization method can be selected and used, but in general, a cationic polymerization method is adopted.

In the case of obtaining the β-pinene polymer used in the present invention according to the cationic polymerization method, a known cationic polymerization catalyst is appropriately used as the polymerization catalyst. Specifically, BF ₃ , BF ₃ OEt ₂ , BBr ₃ , BBr ₃ OEt ₂ , AlCl ₃ , AlBr ₃ , AlI ₃ , TiCl ₄ , TiBr ₄ , TiI ₄ , FeCl ₃ , FeCl ₂ , SnCl ₂ , SnCl ₄ , WCl ₆ , MoCl ₅ , SbCl ₅ , TeCl _2, etc., Group 3-16 group metal halogen compounds; HF, HCl, HBr, etc. hydrogen acids; H ₂ SO ₄ , H ₃ BO ₃ , HClO ₄ , oxo acids such as CH ₃ COOH, CH ₂ ClCOOH, CHCl ₂ COOH, CCl ₃ COOH, CF ₃ COOH, p-toluenesulfonic acid, CF ₃ SO ₃ H, H ₃ PO ₄ , P ₂ O ₅ , and these Polymer compounds such as ion exchange resins having a group; heteropolyacids such as phosphomolybdic acid and phosphotungstic acid; SiO ₂ , Al ₂ O ₃ , SiO ₂ -Al ₂ O ₃ , MgO-SiO ₂ , B ₂ O ₃ —Al ₂ O ₃ , WO ₃ —Al ₂ O ₃ , Zr ₂ O ₃ —SiO ₂ , sulfated zirconia, tungstate zirconia, zeolite exchanged with H ⁺ or rare earth elements, activated clay, acidic Examples thereof include solid acids such as solid phosphoric acid in which clay, γ-Al ₂ O ₃ , and P ₂ O ₅ are supported on diatomaceous earth.

These cationic polymerization catalysts may be used in combination, and other compounds may be added to the polymerization system. Such other compounds are compounds that can improve the activity of the catalyst, for example, by adding them. Examples of compounds that improve the activity of metal halide compounds as acidic compounds include MeLi, EtLi, BuLi, Et ₂ Mg, EtMgBr, Et ₃ Al, Et ₂ AlCl, EtAlCl ₂ , Et ₃ Al ₂ Cl ₃ , (I-Bu) ₃ Al, Et ₂ Al (OEt), metal alkyl compounds such as Me ₄ Sn, Et ₄ Sn, Bu ₄ Sn, Bu ₃ SnCl; 2-methoxy-2-phenylpropane, t-butanol, 1 , 4-bis (2-methoxy-2-propyl) benzene, 2-phenyl-2-propanol, and the like are exemplified as compounds used as a polymerization initiator in living cationic polymerization.

  Further, as a polymerization method of the β-pinene polymer used in the present invention, a solution polymerization method using a solvent may be used. The solvent that can be used varies depending on the polymerization method employed, and thus it is difficult to define it uniquely. For example, aromatic hydrocarbon solvents such as benzene, toluene, xylene, etc .; pentane, hexane, heptane, Aliphatic hydrocarbon solvents such as octane, cyclopentane, cyclohexane, methylcyclohexane, decalin; halogenated hydrocarbon solvents such as methyl chloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethylene; esters, Examples thereof include oxygen-containing solvents such as ether. In view of reactivity, it is preferable to use an aromatic hydrocarbon solvent, an aliphatic hydrocarbon solvent, a halogenated hydrocarbon solvent, or the like. These solvents may be used alone or in combination of two or more.

  The amount of such a solvent used is not particularly limited, but is usually about 100 to 10000 parts by mass, preferably 150 to 5000 parts by mass, with respect to 100 parts by mass of a monomer such as β-pinene. Preferably it is 200-3000 mass parts. When the amount of the solvent is small, uniform mixing of the polymerization catalyst becomes difficult, so that the reaction becomes non-uniform, and a uniform polymer cannot be obtained, or the control of the reaction becomes difficult. On the other hand, when the amount of solvent is large, there is a problem that productivity is lowered.

  And when performing a polymerization reaction, -80 degreeC-100 degreeC is preferable normally, -40 degreeC-80 degreeC is more preferable especially, -20 degreeC-80 degreeC is the most preferable especially. If this reaction temperature is too low, the progress of the reaction is slow, and if it is too high, it becomes difficult to control the reaction and it is difficult to obtain reproducibility.

  The reaction pressure for conducting the polymerization reaction is not particularly limited, but is preferably about 0.5 to 50 atm, and more preferably 0.7 to 10 atm. Usually, the polymerization reaction is performed at around 1 atm.

  Furthermore, the reaction time for conducting the polymerization reaction is not particularly limited, and the reaction time may be appropriately determined so that a β-pinene polymer is obtained in good yield according to conditions such as reaction temperature and reaction pressure. Good. Usually, it is about 0.01 to 24 hours, preferably 0.2 to 10 hours.

  By the way, the β-pinene polymer produced by the polymerization reaction can be obtained by, for example, reprecipitation, solvent removal under heating, solvent removal under reduced pressure, solvent removal with steam (steam stripping), etc. It can be separated and obtained from the reaction mixture by a normal operation in isolation from the solution.

The β-pinene polymer used in the present invention preferably has hydrogenated olefinic double bonds from the viewpoints of weather resistance, light resistance, impact resistance, heat resistance and the like. The hydrogenation rate is generally preferably 90% or more, more preferably 95% or more, and most preferably 99% or more. . In the present invention, the β-pinene polymer is hydrogenated and shows the hydrogenation rate ([number of hydrogenated olefinic double bonds] / [before hydrogenation]). The number of olefinic double bonds in the polymer]]) × 100 is desirably 95% or more. The hydrogenation rate of the unsaturated double bond (carbon-carbon double bond) in the hydrogenated polymer is determined by iodine titration method, infrared spectroscopic spectrum measurement, nuclear magnetic resonance spectrum ( ¹ H-NMR spectrum). It can be calculated using an analysis means such as measurement.

  Here, the method for hydrogenating the β-pinene polymer used in the present invention is not particularly limited, and a known method can be used. For example, homogeneous catalysts such as Wilkinson complex, cobalt acetate / triethylaluminum, nickel acetylacetonate / triisobutylaluminum, diatomaceous earth, magnesia, alumina, silica, alumina-magnesia, silica-magnesia, silica-alumina, synthetic zeolite, etc. A known method using a heterogeneous catalyst or the like in which a catalyst metal such as nickel, palladium, or platinum is supported on a support can be used.

  As a solvent that can be used for hydrogenation, any organic solvent that dissolves the polymer and is inert to the hydrogenation catalyst can be used. Specifically, aromatic hydrocarbon solvents such as benzene, toluene, xylene; aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, cyclopentane, cyclohexane, methylcyclohexane, decalin; methyl chloride, methylene chloride Halogenated hydrocarbon solvents such as 1,2-dichloroethane, 1,1,2-trichloroethylene; oxygen-containing solvents such as esters and ethers. In view of reactivity, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents and the like are preferable. These solvents may be used alone or in combination of two or more.

Furthermore, although the reaction temperature of the hydrogenation reaction depends on the hydrogenation catalyst used and the hydrogen pressure, it is generally preferably about 20 ° C to 250 ° C, more preferably 25 ° C to 150 ° C, and even more preferably 40 ° C to 100 ° C. Is most preferred. If the reaction temperature is too low, the reaction will not proceed smoothly, and if the reaction temperature is too high, side reactions and molecular weight will tend to occur. The hydrogen pressure is preferably about normal pressure to about 200 kgf / cm ² , more preferably 5 to 100 kgf / cm ² . If the hydrogen pressure is too low, the reaction does not proceed smoothly, and if the hydrogen pressure is too high, there are restrictions on the apparatus.

  In addition, the density | concentration of (beta) -pinene polymer in such a hydrogenation reaction system is about 2 mass%-40 mass% normally, Preferably it is 3 mass%-30 mass%, More preferably, it is 5 mass%-20 % By mass. If the concentration of β-pinene polymer is low, productivity is likely to decrease, which is not preferable. Moreover, when the density | concentration of (beta) -pinene polymer is too high, the hydrogenated polymer may precipitate or the viscosity of a reaction mixture may become high and it may become difficult to perform stirring smoothly, and is unpreferable.

  The reaction time of the hydrogenation reaction depends on the hydrogenation catalyst used, the hydrogen pressure, and the reaction temperature, but is usually about 0.1 to 50 hours, preferably 0.2 to 20 hours, more preferably 0.5 hours to 10 hours will be employed.

  Furthermore, the β-pinene polymer after the hydrogenation reaction may be polymerized by, for example, reprecipitation, solvent removal under heating, solvent removal under reduced pressure, or solvent removal with steam (steam stripping). The product is separated and obtained from the reaction mixture by a normal operation for isolation from the solution.

  By the way, the molecular weight of the β-pinene polymer used in the present invention is 30,000 to 100 in terms of weight average molecular weight from the viewpoints of the viscosity and melt viscosity of the polymerization solution, moldability, strength of the transparent material for vehicle lamps, and heat resistance. It is preferably about 10,000, more preferably 40,000 to 500,000, particularly preferably 60,000 to 250,000, and most preferably 90,000 to 200,000. The weight average molecular weight of the polymer can be calculated using a known analysis method such as gel permeation chromatography (GPC) obtained in terms of polystyrene or static light scattering measurement (SLS).

  In addition, the glass transition temperature (Tg) of the β-pinene polymer used in the present invention is preferably higher from the usage environment of the transparent material for vehicle lamps. Among these, it is more preferable that the temperature is 110 ° C. or higher. The upper limit of the glass transition temperature is not particularly defined, but is preferably about 200 ° C. This is because, in an amorphous polymer such as the β-pinene polymer used in the present invention, if the glass transition temperature is too high, the entanglement of the polymer is reduced and the molded product may become brittle.

  Further, the total light transmittance of the β-pinene polymer used in the present invention is preferably higher. Generally, it is preferably 80% or more in a flat specimen having a thickness of 3.2 mm, more preferably 85% or more. More preferably, 90% or more is most preferable.

  Furthermore, the β-pinene polymer used in the present invention preferably has a lower water absorption rate from the viewpoint of dimensional stability. The water absorption of such β-pinene polymer is preferably 0.2% or less as saturated water absorption when placed in an atmosphere of 60 ° C. and 90% RH (relative humidity), and more preferably 0.1% or less. In particular, 0.05% or less is most preferable. A β-pinene polymer giving such a water absorption rate is advantageously selected.

  The β-pinene polymer used in the present invention is also characterized by a low specific gravity. Since the specific gravity is small, a lighter transparent material for vehicle lighting can be obtained. Accordingly, the specific gravity of the β-pinene polymer used in the present invention needs to be 0.85 or more and less than 1.0, and more preferably 0.85 to 0.98. This is because it is difficult to obtain a polymer having a specific gravity smaller than 0.85, and when the specific gravity is 1.0 or more, the object of weight reduction cannot be sufficiently achieved.

  In addition, since the β-pinene polymer used in the present invention has a large flexural modulus and is difficult to be deformed due to bending, it is possible to make a transparent material for a vehicle lamp made of such a β-pinene polymer thinner. It has features that can be done. In general, the flexural modulus of the β-pinene polymer is preferably 2500 MPa or more, more preferably 2700 MPa or more.

  In addition, the β-pinene polymer for molding the transparent material for vehicle lamps according to the present invention may contain various known compounding agents as needed, as long as the object of the present invention is not impaired. Or two or more types can be used in combination.

  Specific examples of such various compounding agents are not particularly limited as long as they are usually used in the resin industry. For example, antioxidants, ultraviolet absorbers, light stabilizers, near infrared absorption And compounding agents such as a colorant such as a colorant, a dye and a pigment, a lubricant, a plasticizer (softening agent), an antistatic agent, a fluorescent brightening agent, and a filler.

  Among them, examples of antioxidants include phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, etc. Among them, phenolic antioxidants are preferable, and alkyl-substituted phenolic oxidations. Inhibitors are particularly preferred.

  As the phenolic antioxidant used here, specifically, conventionally known ones can be used. For example, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methyl Benzyl) -4-methylphenyl acrylate, 2,4-di-t-amyl-6- (1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl) phenyl acrylate, etc. Acrylate compounds such as those described in JP-A-179953 and JP-A-1-168463; octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,2′-methylene -Bis (4-methyl-6-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5- Limethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis (methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxy) Phenylpropionate) methane [i.e. pentaerythrimethyl-tetrakis (3- (3,5-di-t-butyl-4-hydroxyphenylpropionate)], triethylene glycol bis (3- (3-t-butyl- Alkyl-substituted phenolic compounds such as 4-hydroxy-5-methylphenyl) propionate); 6- (4-hydroxy-3,5-di-t-butylanilino) -2,4-bisoctylthio-1,3,5 -Triazine, 4-bisoctylthio-1,3,5-triazine, 2-octylthio-4,6-bis- (3,5-di-t-butyl-4-oxyani Roh) triazine group-containing phenol compounds such as 1,3,5-triazine.

The phosphorus antioxidant is not particularly limited as long as it is usually used in the general resin industry. For example, triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris ( Nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, 10- (3,5-di-t-butyl-4-hydroxybenzyl)- Monophosphite compounds such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tri Decylphosphite), 4,4′-isopropylidene-bis (phenyl-di-alkyl (C ₁₂ -C ₁₅ ) phosphite) And diphosphite-based compounds. Among these, monophosphite compounds are preferable, and tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite and the like are particularly preferable.

  Furthermore, examples of the sulfur antioxidant include dilauryl 3,3-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl 3,3-thiodipropionate, lauryl stearyl 3,3. -Thiodipropionate, pentaerythritol-tetrakis- (β-lauryl-thiopropionate), 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro [5,5 ] Undecane etc. can be mentioned.

  And these antioxidant can be used individually or in combination of 2 or more types, respectively. The blending amount of such an antioxidant is appropriately determined within a range where the object of the present invention is not impaired, but is usually 0.001 with respect to 100 parts by mass of the β-pinene polymer. It is about -5 mass parts, Preferably it is the range of 0.01-1 mass part.

  Examples of the ultraviolet absorber include 2- (2-hydroxy-5-methylphenyl) 2H-benzotriazole, 2- (3-t-butyl-2-hydroxy-5-methylphenyl) -5-chloro- 2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) ) -2H-benzotriazole, 5-chloro-2- (3,5-di-t-butyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (3,5-di-t-amyl-2-) Benzotriazole ultraviolet absorbers such as hydroxyphenyl) -2H-benzotriazole; 4-t-butylphenyl-2-hydroxybenzoate, phenyl-2-hydroxy Zoate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2- (2H- Benzotriazol-2-yl) -4-methyl-6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol, 2- (2-hydroxy-5-t-octylphenyl) -2H-benzotriazole Benzoate ultraviolet absorbers such as 2- (2-hydroxy-4-octylphenyl) -2H-benzotriazole; 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone -5-sulfonic acid trihydrate, 2-hydroxy-4-octyloxybenzophenone, 4 Benzophenone series such as dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone UV absorbers; acrylate UV absorbers such as ethyl-2-cyano-3,3-diphenyl acrylate, 2′-ethylhexyl-2-cyano-3,3-diphenyl acrylate; [2,2′-thiobis (4- t-octylphenolate)]-2-ethylhexylamine nickel and other metal complex ultraviolet absorbers and the like can be used.

  Furthermore, examples of the light stabilizer include 2,2,6,6-tetramethyl-4-piperidylbenzoate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, and bis (1,2 , 2,6,6-pentamethyl-4-piperidyl) -2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate, 4- (3- (3,5 -Di-t-butyl-4-hydroxyphenyl) propionyloxy) -1- (2- (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy) ethyl) -2,2, Examples thereof include hindered amine light stabilizers such as 6,6-tetramethylpiperidine.

  In addition, as the near-infrared absorber, for example, cyanine-based near-infrared absorber; pyrylium-based near-infrared absorber; squarylium-based near-infrared absorber; croconium-based near-infrared absorber; Infrared absorbers; dithiol metal complex-based near infrared absorbers; naphthoquinone near infrared absorbers; anthraquinone near infrared absorbers; indophenol near infrared absorbers; As commercially available near infrared absorbers, SIR-103, SIR-114, SIR-128, SIR-130, SIR-132, SIR-152, SIR-159, SIR-162 (above, Mitsui Toatsu Dye Co., Ltd.) Company-made), Kayasorb IR-750, Kayasorb IRG-002, Kayasorb IRG-003, Kayasorb IR-820B, Kayasorb IRG-022, Kayasorb IRG-023, Kayasorb CY9, Kayasorb CY9, , Manufactured by Nippon Kayaku Co., Ltd.).

  The dye is not particularly limited as long as it is uniformly dispersed / dissolved in the β-pinene polymer to be used, but has excellent compatibility with the β-pinene polymer used in the present invention. Therefore, oil-soluble dyes (various CI solvent dyes) are widely used. Specific examples of the oil-soluble dye include “Color Index” published in The Society of Dyers and Colorists, Vol. 3. Various C.I. I. Solvent dyes may be mentioned.

  Among the pigments, organic pigments include, for example, diarylide pigments such as Pigment Red 38; azo lake pigments such as Pigment Red 48: 2, Pigment Red 53, and Pigment Red 57: 1; Pigment Red 144 and Pigment Red 166. Pigment Red 220, Pigment Red 221 and Pigment Red 248; condensed azo pigments such as Pigment Red 171, Pigment Red 175, Pigment Red 176, Pigment Red 185 and Pigment Red 208; Pigment Red 122 and the like Quinacridone pigments; perylene pigments such as Pigment Red 149, Pigment Red 178, and Pigment Red 179; and anthraquinone pigments such as Pigment Red 177. Examples of inorganic pigments include titanium oxide, carbon black, red pepper, chrome red, molybdenum red, resurge, and iron oxide.

  As the lubricant, organic compounds such as fatty alcohol esters, polyhydric alcohol esters or partial esters, inorganic fine particles, and the like can be used. Here, examples of the organic compound include glycerol monostearate, glycerol monolaurate, glycerol distearate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and the like.

  In addition, inorganic fine particles can generally be used as other lubricants. Here, the inorganic fine particles include oxides, sulfides, hydroxides, nitrides, halides, carbonates, sulfates, acetic acids of the elements of Groups 1, 2, 4, and 6-14 of the periodic table. Examples thereof include fine particles of salts, phosphates, phosphites, organic carboxylates, silicates, titanates, borates and their hydrates, composite compounds centered on them, natural compounds, and the like.

  Examples of the plasticizer include tricresyl phosphate, trixylenyl phosphate, triphenyl phosphate, triethylphenyl phosphate, diphenyl cresyl phosphate, monophenyl dicresyl phosphate, diphenyl monoxylenyl phosphate. Phosphate triester plasticizers such as phosphate, monophenyldixylenyl phosphate, tributyl phosphate, triethyl phosphate; dimethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-n-octyl phthalate, di-phthalate Phthalate plasticizers such as 2-ethylhexyl, diisononyl phthalate, octyldecyl phthalate, and butylbenzyl phthalate; fatty acid monobasic acids such as butyl oleate and glycerol monooleate Plasticizers; dihydric alcohol ester plasticizers; oxyester plasticizers and the like can be used. Of these, phosphate triester plasticizers are preferred, and tricresyl phosphate and trixylenyl phosphate are preferred. Particularly preferred.

Furthermore, as specific examples of other plasticizers, squalane (C ₃₀ H ₆₂ , Mw = 422.8), liquid paraffin (white oil, ISO VG10, ISO VG15, ISO VG32, ISO VG32 as defined in JIS-K-2231) VG68, ISO VG100, ISO VG8 and ISO VG21), polyisobutene, hydrogenated polybutadiene, hydrogenated polyisoprene, and the like. Among these, squalane, liquid paraffin, and polyisobutene are preferably used.

  Furthermore, examples of the antistatic agent include long-chain alkyl alcohols such as stearyl alcohol and behenyl alcohol, fatty acid esters of polyhydric alcohols such as glycerol monostearate and pentaerythritol monostearate, and stearyl alcohol and behenyl alcohol. Particularly preferred.

  These compounding agents can be used alone or in combination of two or more thereof, but the combination ratio is appropriately selected within a range not impairing the object of the present invention. Further, the respective compounding amounts of the above-mentioned compounding agents are also appropriately selected within a range that does not impair the object of the present invention, but for each compounding agent, usually with respect to 100 parts by mass of the β-pinene polymer, A range of about 0.001 to 5 parts by mass, preferably 0.01 to 1 part by mass is employed.

  The β-pinene polymer for molding the transparent material for vehicle lamps according to the present invention as described above is blended with other polymer components as needed within a range not impairing the object of the present invention. I can do it. As this other polymer, for example, there is a rubbery polymer compounded to improve impact resistance. Specifically, natural rubber, polybutadiene rubber, polyisoprene rubber, acrylonitrile / butadiene copolymer rubber, etc. Diene rubber: styrene / butadiene copolymer rubber, styrene / isoprene copolymer rubber, styrene / butadiene / isoprene terpolymer rubber; hydrogenated diene rubber; ethylene such as ethylene / propylene copolymer・ Saturated polyolefin rubber such as α-olefin copolymer, propylene / other α-olefin copolymer; ethylene / propylene / diene copolymer, α-olefin / diene copolymer, isobutylene / isoprene copolymer, Α-olefin / diene polymer rubber such as isobutylene / diene copolymer; Tan rubber, silicone rubber, polyether rubber, acrylic rubber, propylene oxide rubber, special rubber such as ethylene / acrylic rubber; heat of styrene / butadiene / styrene block copolymer rubber, styrene / isoprene / styrene block copolymer rubber, etc. Mention may be made of a plastic elastomer; a hydrogenated thermoplastic elastomer; a urethane-based thermoplastic elastomer; a polyamide-based thermoplastic elastomer; a 1,2-polybutadiene-based thermoplastic elastomer. The blending amount is appropriately selected within a range not impairing the object of the present invention, but is usually about 3 to 30 parts by mass, preferably 5 with respect to 100 parts by mass of the β-pinene polymer. It is the range of -20 mass parts.

  The β-pinene polymer used in the present invention is mixed as necessary with the above-described blending components and used as a molding material. There is no particular limitation as long as these compounding agents are sufficiently dispersed. For example, a method of kneading a resin in a molten state with a mixer, a twin-screw kneader, a roll, a brabender, an extruder, a method of dissolving and dispersing in an appropriate solvent and solidifying, a casting method, or a direct drying method The method of removing is used. Among them, when a biaxial kneader is used, it is often used as a molding material after kneading, usually extruded into a rod shape in a molten state, cut into an appropriate length with a strand cutter, and pelletized.

  The lamp cover and the reflector in the vehicle lamp targeted by the present invention are obtained by molding the molding material. As the molding method, conventionally known molding methods are appropriately employed. For example, injection molding, press molding, extrusion blow molding, injection blow molding, multilayer blow molding, connection blow molding, double wall blow molding, stretch blow Molding, vacuum molding, rotational molding, etc. will be used. In terms of molding accuracy, injection molding or press molding is preferably employed. Although the melting temperature of the resin at the time of molding varies depending on the type of β-pinene polymer, it is usually about 100 to 400 ° C, preferably 200 to 350 ° C.

  In the present invention, the “lamp” is used as having at least a light source and a lamp cover, and the “vehicle” is a two-wheeled vehicle, a three-wheeled vehicle, a four-wheeled vehicle, other vehicles, a railway. It is used to mean vehicles in a broad sense such as vehicles, forklifts and other industrial vehicles. “Vehicle lamp” means a lamp for illumination, identification, or signage mounted on such various vehicles, and is not particularly limited, but includes a headlamp, a taillamp, a brake. A lamp (stop lamp), a direction indicator lamp (so-called blinker), a vehicle width lamp, a reverse lamp, and the like are applicable.

  In addition, the light source is not particularly limited, but a lamp with low power consumption and high illuminance is preferable. For example, an HID lamp or the like is used. Furthermore, a lens that is a lamp cover broadly means a lens that protects a light source and transmits light from the light source to irradiate the outside. The transparent material according to the present invention is mainly intended for a lens that is a lamp cover in such a vehicle lamp, but can also be used as a reflector or the like. When used as a reflector, a reflection film such as a metal oxide film is formed on the surface as well known.

  It should be noted that the transparent material according to the present invention, particularly the lens, can be provided with a protective layer as necessary so that the surface thereof is not scratched or soiled. The method for forming the protective layer is not particularly limited. For example, there is a method in which an ultraviolet curable resin or a thermosetting resin is applied to the surface of a molded article by a method such as spin coating, spray coating, dipping, or flow coating, and then cured.

  Hereinafter, some examples of the present invention will be shown and the present invention will be more specifically clarified, but the present invention is not limited by the description of such examples. It goes without saying. In addition to the following examples, the present invention can be subjected to various changes, corrections, improvements and the like based on the knowledge of those skilled in the art without departing from the spirit of the present invention. Should be understood.

  First, a β-pinene polymer hydrogenated product was synthesized as follows as a material for forming a transparent material for a vehicle lamp according to the present invention.

  About the fully dried glass flask with a cock, after the inside was sufficiently substituted with nitrogen, dehydrated N-hexane: 184 parts by mass, dehydrated methylene chloride: 210 parts by mass, and dehydrated diethyl ether : 0.5 part by mass was added and cooled to -78 ° C. While stirring the mixture at -78 ° C, hexane solution of ethylaluminum dichloride (concentration: 1.0 mol / L): 7.2 parts by mass was further added. Next, in a state where the inside of the flask was kept at −78 ° C., when 3.0 parts by mass of a hexane solution of p-dicumulyl chloride (concentration: 0.1 mol / L) was added, the color changed to red amber. Thereafter, 60 parts by mass of β-pinene that was immediately purified by distillation was added to the flask over 1 hour. The solution gradually became dark blue and the viscosity of the solution increased. After the addition of β-pinene, 30 parts by mass of methanol was added to terminate the reaction. In the flask, an aqueous solution obtained by adding 5 parts by mass of citric acid to 100 parts by mass of distilled water is added and stirred for 5 minutes. Then, the aqueous layer is extracted, and the aqueous layer becomes neutral by adding distilled water. Until the aluminum compound was removed. The obtained organic layer was reprecipitated in a mixed solvent of methanol / acetone (50/50 vol%): 5000 parts by mass and then sufficiently dried to obtain 60 parts by mass of β-pinene polymer (A1). . The obtained β-pinene polymer (A1) had a weight average molecular weight of 116,000, a number average molecular weight of 51,000, and a glass transition temperature of 95 ° C.

By adding 70 parts by mass of cyclohexane and 30 parts by mass of the β-pinene polymer (A1) obtained as described above to a pressure vessel equipped with a stirrer substituted with nitrogen, and stirring the mixture, a β-pinene polymer ( A1) was completely dissolved. Next, 5% palladium-supported alumina (manufactured by NE ChemCat) as a hydrogenation catalyst: 30 parts by mass was added and sufficiently dispersed by stirring, and then the inside of the pressure vessel was sufficiently replaced with hydrogen. While stirring at 1000 rpm, the mixture was reacted at 100 ° C. and hydrogen pressure of 40 kgf / cm ² for 6 hours, and then returned to normal pressure. The reaction solution was diluted by adding 200 parts by mass of cyclohexane, filtered through a 0.5 μm Teflon (registered trademark) filter to separate and remove the catalyst, and then a mixed solvent of methanol / acetone (50/50 vol%): 5000 After re-precipitation in parts by mass, it was sufficiently dried to obtain 29 parts by mass of β-pinene polymer hydrogenated product (H1). When the hydrogenation rate of the obtained β-pinene polymer hydrogenated product (H1) was determined from ¹ H-NMR, it was 99.9%, the weight average molecular weight was 112,000, and the number average molecular weight was 50,800. The glass transition temperature was 130 ° C. and the specific gravity was 0.930.

  Thereafter, 0.2 mass of 2- (5-methyl-2hydroxyphenyl) benzotriazole, which is an ultraviolet absorber, was added to 100 parts by mass of the thus obtained high molecular weight β-pinene polymer hydrogenated product (H1). After mixing a mass part and 0.2 parts by mass of Irganox 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.), which is a phenolic antioxidant, using a Henschel mixer, melt-kneading using an extruder, A pellet-like β-pinene polymer hydrogenated composition (M1) was obtained.

  In addition, about the material obtained at each above-mentioned process, and the material manufactured at the following process, the physical-property measurement was performed as follows.

-Molecular weight-
The number average molecular weight and the weight average molecular weight are both determined in terms of polystyrene based on measurement by gel permeation chromatography (GPC). Here, HLC-8020 (product number) manufactured by Tosoh Co., Ltd. is used as the GPC device, and TSKgel / GMH-M manufactured by Tosoh Co., Ltd. and one G2000H are connected in series as the column. Using.

-Hydrogenation rate-
^{From the 1} H-NMR spectrum, the hydrogenation rate {([number of hydrogenated olefinic double bonds] / [hydrogen] is determined by the reduction rate (%) of olefinic double bond protons (4 to 6 ppm) of the raw material resin. The number of olefinic double bonds in the polymer before addition]) × 100 (%)} was determined.

-Glass transition temperature (Tg)-
It measured by the differential scanning calorimetry (DSC) using the sample which fully dried and removed the solvent. First, a sample is heated from 25 ° C. to 200 ° C. at a rate of temperature increase of 10 ° C./min under a stream of nitrogen of 100 ml / min to obtain a DSC curve. Next, using the obtained DSC curve, as shown in FIG. 1, a parallel line E passing through the intersection of the center tangent B and the base line C before the transition and parallel to the temperature axis, and the center tangent B A parallel line F passing through the intersection of the base line D after the transition and parallel to the temperature axis is drawn. In this specification, the temperature A at the intersection of the parallel line G that bisects the two parallel lines E and F and the DSC curve is defined as the glass transition temperature (Tg). In addition, here, DSC30 (product number) manufactured by METTLER TOLEDO Co., Ltd. was used as a measuring device.

-Specific gravity-
It measured according to A method of JIS-K-7112: 1999. Judgment criteria are as follows.
○: Specific gravity <1.0
Δ: 1.0 ≦ specific gravity <1.1
×: 1.1 ≦ specific gravity

-Total light transmittance-
About the obtained test piece which consists of a transparent material for vehicle lamps, it measured based on JIS-K-7361-1 using HR-100 (product number) by Murakami Color Research Laboratory.

-Water absorption rate-
A press-molded plate having a length of 140 mm, a width of 60 mm, and a thickness of 0.8 mm was placed in an atmosphere of 60 ° C. and 90% RH for 10 days, and the ratio of the weight increased from the initial weight. Was the water absorption. The arithmetic expression is as follows.
Water absorption (%) = Weight increase x 100 / initial weight

-Light resistance-
Using a sunshine weather meter S80 manufactured by Suga Test Instruments Co., Ltd., an accelerated exposure test was conducted for 2000 hours under the conditions of black panel temperature: 63 ° C., relative humidity: 50%, spray cycle: 18 minutes / 2 hours, The yellowing degree (ΔYI) before and after the test was measured and evaluated according to the following criteria. YI was measured according to JIS-K-7103.
○: ΔYI ≦ 1 Long-term light resistance is very good ×: 1 <ΔYI Long-term light resistance is poor

-Flexural modulus-
Using the test piece, the flexural modulus at 23 ° C. was measured using an autograph (manufactured by Shimadzu Corporation) according to JIS-K-7171. In addition, the determination criteria are as follows.
○: Flexural modulus is 2500 MPa or more ×: Flexural modulus is less than 2500 MPa

-Solvent resistance-
The test pieces were immersed in an aqueous sodium carbonate solution of pH 9 and hydrochloric acid and ethanol of pH 4 for 48 hours, respectively, and their appearances were observed and evaluated according to the following evaluation criteria.
○: No change in appearance with any solvent, no change in turbidity and total light transmittance ×: Change in appearance with any solvent. Turbidity and total light transmittance decreased

Example 1
The high molecular weight β-pinene polymer hydrogenated composition (M1) obtained above is melt-kneaded using an extruder, extruded at an extruded resin temperature of 250 ° C., width: 100 mm, thickness: A transparent material (P1) for vehicle lamps of 2 mm was obtained. And this transparent material for vehicle lamps (P1) obtained was evaluated, and the results are shown in Table 1 below.

-Comparative Example 1-
Instead of the β-pinene polymer hydrogenated composition (M1) of Example 1, Zeonore 1060R (manufactured by ZEON CORPORATION) was used as the norbornene-based ring-opening polymer hydrogenated product, and Example 1 Similarly, a transparent material (Q1) for vehicle lamps was obtained. And it carried out similarly to the Example about the obtained transparent material (Q1) for vehicle lamps. The evaluation results are shown in Table 1 below.

-Comparative Example 2-
Instead of the β-pinene polymer hydrogenated composition (M1) of Example 1, Parapet GH-S (manufactured by Kuraray Co., Ltd.) was used as polymethyl methacrylate, in the same manner as in Example 1, A transparent material (Q2) for vehicle lighting was obtained. And the evaluation result of the obtained transparent material for vehicle lamps (Q2) is shown in Table 1 below.

  As is apparent from the results in Table 1, it can be seen that the transparent material for vehicle lighting according to the present invention is excellent in transparency, heat resistance, light resistance and solvent resistance, and is lightweight. Further, it is recognized that the bending elastic modulus is high, and even a thin molded body is hardly deformed.

It is explanatory drawing which shows the method of calculating | requiring the glass transition temperature in an Example from a DSC curve.

Claims (3)

  A transparent material for a vehicle lamp characterized by comprising a β-pinene polymer having a specific gravity of 0.85 or more and less than 1.0 and a glass transition temperature of 100 ° C. or more.   The β-pinene polymer is hydrogenated, and ([number of olefinic double bonds hydrogenated] / [number of olefinic double bonds in the polymer before hydrogenation] 2) The transparent material for vehicle lighting according to claim 1, wherein the value of x100 is 95% or more. A vehicle lamp characterized by using the transparent material according to claim 1 or 2.

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