JPH11162210A - Lamp for vehicle and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent water and dust, etc., from invading inside by integratedly molding a lens and a lamp housing. SOLUTION: A lamp for a vehicle is obtained comprising a lens and 1 and a lamp housing 2 which are integratedly molded by a die slide injection molding method. Although, a resin comprised by the lamp housing 2 is not particularly limited, similarly to the lens 1, it is preferable to use a resin having excellent transparent performance such as acrylic resin, e.g. polycarbonate, and polymethylmethacrylate. The lamp housing 2 comprises the resin having excellent transparent performance, so that at a predetermined portion on the outer surface of the lamp housing 2, a reflecting film comprising aluminium and silver, etc., is molded, thereby enabling a lamp for vehicle having high total reflectance and excellent performance to be provided. Preferably, the reflecting film is molded by a specific silver mirror reaction, and thereby to enable the reflecting film which is even to be efficiently molded for a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens and a lamp housing which are integrally formed,
The present invention relates to a vehicle lamp having no seal portion and a method of manufacturing the same. The lens and the lamp housing can be integrally formed by a die slide injection molding method, so that entry of water, dust, and the like into the lamp is reliably prevented. Further, in the vehicle lamp of the present invention, a reflective film having a uniform thickness can be easily formed on the outer surface of the lamp housing.

[0002]

2. Description of the Related Art Conventionally, a vehicle lamp has a cross section shown in FIG.
As shown in FIG. 1, the lens 1 and the lamp housing 2 formed separately are combined. For example, a concave portion provided on the peripheral edge of the front opening of the lamp housing is fitted with a convex portion provided on the peripheral edge of the lens, and the fitting portion 5 is filled with a hot melt adhesive 6 or the like. Then, they are integrally formed by joining and sealing. The light source bulb 8 used in the vehicle lamp generates considerable heat when turned on. Therefore, the resin constituting the lens and the lamp housing needs to have appropriate heat resistance, and is usually a resin that can withstand a temperature of about 80 to 130 ° C. for a considerable time.

As a resin capable of withstanding the heat generated by the light source bulb, conventionally, as a resin constituting the lamp housing, polypropylene or the like blended with an inorganic filler such as talc has been used. Further, as a resin constituting the lens, polycarbonate or an acrylic resin is used because excellent transparency is required in addition to heat resistance. And
Usually, a reflective film made of aluminum is provided on the inner surface of the lamp housing. This reflection film is formed by a conventional method such as a coating method, a vacuum evaporation method, and a hot stamping method.

[0004]

However, in a conventional vehicle lamp in which a lens and a required portion of a lamp housing are fitted, filled with an adhesive or the like, joined, and sealed, the fitting portion extends over a long period of time. It is not easy to reliably seal. In addition, deterioration of the adhesive and the like over time is inevitable,
Water, dust, etc. may enter the lamp. Further, in the conventional vehicle lamp, since the lamp housing is opaque, the reflection film is necessarily formed on the inner surface of the housing. However, it is not easy to form a required reflective film having a uniform thickness in a concave portion such as the inner surface of the housing by painting, vapor deposition, or the like. Further, it is not easy to adjust the reflectivity to a predetermined film thickness and to obtain a film having a small variation in the reflectivity.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and is excellent in the integration between a lens and a lamp housing, and is intended for a vehicle for preventing water, dust and the like from entering at least from a portion where they are joined. An object of the present invention is to provide a lamp and a method for manufacturing the lamp. In addition, according to the present invention, a reflective film can be provided on the outer surface of the lamp housing, and a vehicle lamp including the reflective film having excellent reflection performance can be easily obtained. In particular, by utilizing a specific silver mirror reaction, a reflective film having a uniform thickness can be efficiently formed in a short time.

[0006]

According to a first aspect of the present invention, there is provided a vehicle lamp comprising a lens and a lamp housing integrally formed by die slide injection molding.

A fifth aspect of the present invention is a method of manufacturing a vehicle lamp by a die slide injection molding method, wherein a lens is formed by one of the molds in a primary injection step. After molding the lamp housing with the other mold, open the mold, then move the movable mold to a position where the lens and the lamp housing face each other, then close the mold, and then perform the secondary injection process. Wherein resin is injected into an outer peripheral portion of a contact surface between the lens and the lamp housing, and the lens and the lamp housing are integrally joined.

The above-mentioned "vehicle lamp" is composed of complicated aspects for both the lens and the lamp housing.
Is advantageous. When a single-axis injection molding machine is used, the lens and the lamp housing are made of the same resin, but the resin injected to join the lens and the lamp housing together may be used. It is preferable to use the same or at least similar ones. By thus joining the lens made of the same resin and the lamp housing with the same or similar resin, it is possible to obtain a more firmly integrated vehicle lamp. The term "similar resin" means that the resins are of the same type but differ in molecular weight, crystallinity, etc., or differ in the blending of various additives.

On the other hand, if a two-axis injection molding machine is used, the lens and the lamp housing can be made of different resins. If the lens and the lamp housing are joined by a resin that can be joined with sufficient strength to both the lens and the resin constituting the lamp housing, a vehicle lamp having no problem in terms of integrity, strength, etc. can be obtained. it can. Further, according to the two-axis injection molding machine, the lens can be colored and transparent, and the lamp housing can be opaque or colorless and transparent. In particular, the resin is an "acrylic resin" such as "polycarbonate" (hereinafter abbreviated as "PC") or polymethyl methacrylate (hereinafter abbreviated as "PMMA"), the lens is colored and transparent, and the lamp housing is used. Is colorless and transparent, it is possible to obtain a vehicle lamp having high practicality and design. The lens can be colored to a required color such as red, green, orange, amber, and amber depending on the type of lamp.

In a vehicle lamp, the lamp housing is usually provided with a reflective film. When the lens and the lamp housing are integrally formed by die slide injection molding, the reflective film is formed as in the second invention. , At the required location on the "outer surface" of the lamp housing. Therefore, in the vehicle lamp of the first invention, even when a two-axis injection molding machine is used, as in the third invention,
It is preferable that not only the lens but also the lamp housing be formed of an acrylic resin such as PC or PMMA which is excellent in transparency. Thereby, a vehicle lamp having excellent regular reflectance can be obtained. PC or PMMA is more expensive than polypropylene which is conventionally used as a resin constituting the lamp housing and which is blended with an inorganic filler such as talc. However, the rigidity is high,
Since the thickness can be reduced, there is no disadvantage in terms of product price.

In the first aspect of the invention, the lens and the lamp housing are integrally joined in-line. Therefore, in applications where a reflective film needs to be provided, the reflective film is formed on the outer surface of the colorless and transparent lamp housing as described above. Forming a reflective film on the outer surface of such a lamp housing is much easier to work and improves productivity as compared to the case where a reflective film is provided on the inner surface. Further, the thickness of the reflection film can be made more uniform, and the reflectance can be easily adjusted. Further, even if there is a variation in the film thickness, the reflection performance is not affected at all. This reflective film can be formed by applying a solution containing aluminum, silver, or the like and drying the solution. The film may be formed by a method such as vapor deposition or sputtering, but is preferably formed by a method using a “solution containing silver” as in the sixth invention. According to the method using the silver mirror reaction, it is possible to form a reflection film made of a silver plating layer having excellent reflection performance in a short time, and to obtain the vehicle lamp of the fourth invention provided with the reflection film. it can.

In forming the silver plating layer, first,
A synthetic resin paint such as an alkyd resin paint which is a main component of an undercoat agent for forming an undercoat layer is selected. This synthetic resin paint is prepared and stored in an appropriate composition in consideration of the effect of the gloss of the silver plating layer and the like on the performance of the reflective film. If the synthetic resin paint has insufficient adhesion to the outer surface of the lamp housing, a transparent primer may be applied to the outer surface of the lamp housing.

On the other hand, a catalyst solution is prepared by adding epoxysilane or epoxy resin to an alkoxytitanium ester such as butyl titanate dimer, tetra-n-butoxytitanium and a polymer thereof, and tetraisopropoxytitanium. As the epoxy silane, an epoxy silane such as β- (3,4-epoxycyclohexyl) ethyl trimethoxy silane or γ-glycidyloxypropyl methoxy silane having a high affinity for the coating material can be used. These epoxy silanes are added in an amount of 2 to 4 parts by weight based on 100 parts by weight of a synthetic resin such as an alkyd resin contained in the paint. Further, as the epoxy resin, an epoxy resin such as a bisphenol A type, a phenol novolak type, and a cresol novolak type can be used. These epoxy resins are likewise synthetic resin 1
It is added so as to be 7 to 13 parts by weight with respect to 00 parts by weight. By adding an appropriate amount of epoxy silane or epoxy resin, the adhesiveness between the undercoat layer and the silver plating layer is improved.

The undercoat agent is prepared by adding 15 to 20 parts by weight of an alkoxytitanium ester to which epoxysilane or epoxy resin has been added to a synthetic resin paint that has been stored, based on 100 parts by weight of the synthetic resin contained in the paint. Parts. This undercoat agent is applied to a required portion on the outer surface of the lamp housing. The alkoxy titanium ester has an effect of accelerating silver precipitation. The ester also facilitates drying of the undercoat agent, and improves the adhesion between the undercoat agent and the silver plating layer. The undercoating agent can be applied to the outer surface of the lamp housing by an appropriate method such as brushing or spraying, but is preferably sprayed.

[0015] In addition, those obtained by adding epoxy silane or epoxy resin to alkoxy titanium ester are usually
Since it can be stored stably for about one month, there is no need to mix immediately before use. However, after mixing with the paint,
Since the pot life differs completely depending on the type of paint, it is preferable to mix only the required amount. Further, the alkoxy titanium ester is sensitive to moisture, and is preferably used at a relative humidity of 65% or less. If the humidity is high,
Due to the fogging phenomenon, the occurrence of unevenness due to insufficient leveling, and the like, it may not be possible to form a silver plating layer having the required reflection performance on the outer surface of the lamp housing.

The thickness of the coating film of the undercoat agent is 2 to 15
Microns, particularly about 3 to 8 microns, which is dried to form an undercoat layer. The undercoat layer has a clean surface, has high catalytic activity for depositing silver, and has excellent adhesion to the silver plating layer. Further, the gloss of the obtained silver plating layer can be easily changed as desired by the composition of the undercoat layer. Silver precipitated by the catalytic action of the alkoxy titanium ester is fixed to the surface of the undercoat layer by the ester residue and the epoxy silane or epoxy resin, and is not easily separated.

The coating film made of an undercoat agent formed on the outer surface of the lamp housing is dried at a temperature of 60 to 70 ° C. for 15 to 30 minutes by a hot air drying furnace or the like. If the drying is insufficient, the silver plating layer may be clouded or cracked due to the effect of the residual solvent. On the other hand, if the drying is excessive, hydrolysis of the alkoxy titanium ester proceeds too much, resulting in insufficient silver precipitation and poor adhesion to the undercoat layer. The lower the temperature of this drying is, the better the operation is because the allowable range of the drying time is widened. Also, depending on the type of paint, 20
It may be dried at a normal temperature of about 35 ° C. for about 2 to 4 hours. Further, it is necessary to take care that dust and dirt in the air do not adhere in the drying step, but by washing the surface of the undercoat layer with pure water or other chemicals for 1 to 2 seconds immediately before the silver mirror reaction. I can deal with it.

An aqueous solution containing silver is applied to the surface of the undercoat layer. The application of the aqueous solution is performed, as in the seventh invention, by using an aqueous solution containing silver and an aqueous solution containing a reducing agent.
Is preferably sprayed and applied, and it is more preferable to spray these aqueous solutions simultaneously with a two-head gun. That is, an ammoniacal silver nitrate aqueous solution and a reducing aqueous solution are simultaneously sprayed by a spray coating machine having a two-head gun, for 1 to 10 seconds, particularly 2 to 7 seconds.
A silver plating layer having a good appearance and the like can be formed within a short time of about 2 seconds to about 5 seconds. The higher the concentration of the above two solutions, the more silver is precipitated, and the lower the concentration, the slower the silver. Therefore, it is necessary to appropriately adjust the concentration according to the size of the spray area, the temperature of the working environment, and the like.
In order to improve the wettability of the aqueous solution containing silver on the undercoat layer, a surfactant can be added to the aqueous solution containing silver. Since the aqueous solution containing silver is an ionic solution, nonionic surfactants that do not react, especially nonionic surfactants having an ethylene oxide group and a hydroxyl group as hydrophilic groups, are used as the surfactant. Agents are preferred.

At room temperature of about 20 to 35 ° C., the aqueous solution containing silver contains 0.3 to 3% by weight, particularly about 0.6 to 2% by weight of silver nitrate in an aqueous ammoniacal silver nitrate solution. As the reducing aqueous solution, a reducing agent such as glyoxal is used in an amount of 2 to 10% by weight, particularly 3 to 7% by weight.
An aqueous solution containing a certain amount is used. A good silver plating layer can be formed by simultaneously spraying an equal amount of the aqueous solution having such a concentration on the surface of the undercoat layer. The effect of the temperature of the working environment is very large, 10 ° C
At low temperatures before and after, silver precipitation is hardly observed in the above-mentioned aqueous solution having the normal concentration, and an aqueous solution having a concentration of 5 to 6 times is required, which is uneconomical. In such a case, measures such as raising the temperature of the aqueous solution are required. On the other hand, when the temperature is unnecessarily high and the silver deposition rate is too high, the silver plating layer becomes cloudy. Therefore, it is preferable to set the temperature of the working environment to about 20 to 35 ° C. in consideration of the speed at which the silver plating layer is formed, workability, cost, and the like.

Further, if necessary, a top coat layer can be formed on the surface of the silver plating layer to protect the silver plating layer. As the top coat layer, a paint used on the surface of a plating layer formed by a normal electrolytic plating method can be used. However, the silver plating layer formed by this silver mirror reaction has a slightly inferior adhesive property with the undercoat layer as compared with a general aluminum film or the like, so that a paint having an excellent adhesive property such as a silicone-modified resin paint is used. Preferably, it is used. The thickness of the top coat layer is not particularly limited, and may be a thickness that covers all of the silver plating layer and sufficiently prevents peeling from the undercoat layer.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for integrally molding a lens and a lamp housing by die slide injection molding and a method for forming a reflection film by silver mirror reaction will be described below. (1) Integral Molding of Lens and Lamp Housing FIG. 1A shows that a lens 1 is molded in one cavity provided between a movable mold A and a fixed mold B by a primary injection step. This shows a state in which the lamp housing 2 is molded in the other cavity. After molding the lens 1 made of acrylic resin such as PC or PMMA and the lamp housing 2 in this manner, the movable mold A and the fixed mold B are opened, and the lens 1 is moved to the movable mold A.
FIG. 1B shows a state in which the lamp housing 2 is housed in the cavity of the fixed mold B.

Thereafter, as shown in FIG.
The movable mold A is slid to move the lens 1 housed in the cavity of the movable mold A to a position facing the lamp housing 2 housed in the fixed mold B. Next, the mold is closed at a position where the lens 1 and the lamp housing 2 face each other, and the lens 1 and the lamp housing 2 are closed.
Are brought into contact with each other at the periphery of the end face thereof, and then the same type of resin as that of the lens 1 and the lamp housing 2 is injected into the outer peripheral edge of the contact surface between the lens 1 and the lamp housing 2 by a secondary injection process. FIG. 1D shows a state in which the lens 1 and the lamp housing 2 are integrally joined.

(2) Formation of reflection film, ie, silver plating layer Toluene was used as a solvent, and 30 g of an alkyd resin was dissolved in 34 ml of the solvent to prepare a coating material. On the other hand, butyl titanate dimer (manufactured by Mitsubishi Gas Chemical Co., Ltd.) 5
1 g of epoxysilane (trade name "KP-392", manufactured by Shin-Etsu Silicone Co., Ltd.) was added to the g. Thereafter, the butyl titanate dimer to which the epoxy silane was added was blended into a paint, stirred and mixed to prepare an undercoat agent. Next, the undercoat agent was applied by spraying to a required portion of the outer surface of the lamp housing 2 formed in (1) to form a coating film having a thickness of 5 microns. Then, at a temperature of 65 ° C., 20
After drying for a minute, an undercoat layer having a thickness of 5 μm was formed.

Next, an aqueous solution containing silver was sprayed onto the surface of the undercoat layer by a spray coating machine having a two-head gun to apply the solution. Examples of the aqueous solution containing silver include:
An aqueous solution containing 5% by weight of silver nitrate was used. Also,
As the reducing aqueous solution, an aqueous solution containing 5% by weight of glyoxal was used. The temperature of the working environment including the temperature of these aqueous solutions was set to 25 ° C., and equal amounts of both aqueous solutions were sprayed. After a few seconds, a silver-plated layer having a clear, glossy and beautiful appearance was formed. When the adhesion (adhesion) of this silver plating layer was evaluated by the grid method of JIS K 5400, it was found that there was almost no peeling, and that the silver plating layer had extremely excellent adhesion.

Thereafter, a silicone-modified resin paint (trade name “KR-
5206 ”) was similarly applied by a spray method to form a coating having a thickness of 5 μm. Next, this was dried in a hot air drying furnace at a temperature of 75 ° C. for 40 minutes to form a top coat layer. The silver plating layer was sufficiently protected by this top coat layer.

[0026]

According to the first aspect of the invention, the lens and the lamp housing are integrally formed by the die slide injection molding method, so that water, dust, etc., due to poor sealing at the fitting portion between the lens and the lamp housing. Is prevented from entering the interior. Further, a sealant such as an adhesive is not required, and a product having excellent design properties can be obtained. Further, a seal margin for fitting is not required, and the width of the lamp can be made substantially the same as that of the light source bulb, so that the product can be easily miniaturized.

Further, by forming the lamp housing from a resin having excellent transparency, a reflective film can be formed on the outer surface of the lamp housing, which facilitates the operation, improves the productivity and makes the film thickness of the reflective film uniform. Can be Further, even if the film thickness varies, the function of the reflection film is not impaired at all.

The vehicle lamp of the present invention has the following effects in addition to the above effects. Since the process is simplified and the number of molds can be reduced, the product cost can be reduced. It is easy to recycle the lens, the lamp housing, and the same or similar resin as the resin that integrally joins them. Since the lens and the lamp housing are melted and joined in the secondary injection step, the integration is very high. Both the lens and the lamp housing can be formed by lens-cut molding, and a vehicle lamp excellent in light-collecting performance or design can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a step of integrally molding a lens and a lamp housing by a die slide injection molding method.

FIG. 2 is a cross-sectional view of a vehicle lamp of the present invention including a lens and a lamp housing formed integrally.

FIG. 3 is a cross-sectional view of a conventional vehicle lamp in which a separately molded lens and a lamp housing are fitted and sealed with an adhesive.

[Explanation of symbols]

A: movable mold, B: fixed mold, C: hydraulic device, 1; lens, 2; lamp housing, 3; joint, 4; reflective film provided on the outer surface of the lamp housing, 5; ,
6; hot melt adhesive; 7; reflective film provided on the inner surface of the lamp housing; 8; light source bulb; 81; bulb socket.

Claims (7)

[Claims] 1. A vehicular lamp comprising a lens and a lamp housing integrally formed by a die slide injection molding method. 2. The vehicle lamp according to claim 1, wherein a reflection film is provided at a required position on an outer surface of the lamp housing. 3. The vehicle lamp according to claim 1, wherein said lens and said lamp housing are made of polycarbonate or acrylic resin. 4. The reflection film is a silver plating layer formed by applying an aqueous solution containing silver to the required portion on the outer surface of the lamp housing and drying it.
The vehicle lamp as described. 5. A method of manufacturing a vehicle lamp by a die slide injection molding method, wherein in a primary injection step, a lens is molded by one mold and a lamp housing is molded by the other mold. The mold is opened, then the movable mold is moved to a position where the lens and the lamp housing face each other, and then the mold is closed. Then, in a secondary injection step, a contact surface between the lens and the lamp housing is formed. A method for manufacturing a vehicle lamp, comprising: injecting a resin into an outer peripheral portion of the lens, and integrally joining the lens and the lamp housing. 6. The vehicle according to claim 5, wherein after the lens and the lamp housing are integrally joined, an aqueous solution containing silver is applied to an outer surface of the lamp housing and dried to form a silver plating layer. Method of manufacturing lamps. 7. After the lens and the lamp housing are integrally joined, an aqueous solution containing silver and an aqueous solution containing a reducing agent are sprayed on the outer surface of the lamp housing, applied and dried, and then dried. The method for manufacturing a vehicle lamp according to claim 5, wherein a plating layer is formed.