JPH05166498A - Beam lamp with front-glass - Google Patents

Abstract

PURPOSE:To provide a beam lamp with a front-glass having no problem in outer appearance and having a very excellent adhesion between a front glass and a mirror, in which, particularly in case the adhesive agent having a low content of low molecular weight siloxane is used, the adhesion is excellent and the frosting of the front glass is prevented. CONSTITUTION:A front glass 6 is bonded using a colorless or minutely colored addition reaction type silicon adhesive agent containing a heat-resistance improver.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a halogen lamp beam lamp with a windshield, and more particularly to a beam lamp in which an adhesive used for adhering a front windshield and the like to a mirror is improved.

[0002]

2. Description of the Related Art In recent years, beam lamps such as halogen lamp bulbs with dichroic mirrors, which are equipped with a windshield for the purpose of safety and prevention of ultraviolet rays, are increasing in number. For the adhesion between the windshield and the dichroic mirror, an epoxy adhesive, a condensation type silicone adhesive or the like has been conventionally used. Since the beam lamp with a windshield itself has a substantially sealed structure, the temperature inside the beam lamp may rise more sharply than in the case without the windshield, and the temperature of the adhesive portion may reach about 250 ° C in some cases. In the case of conventional epoxy adhesives, heat resistance and ultraviolet resistance are not sufficient. Therefore, particularly in the high power type, there is a drawback that the adhesive deteriorates and the windshield comes off, resulting in lack of reliability.

Although ordinary condensation type silicones have the same problem, they are slightly improved as compared with epoxy type. Among the condensation silicone type, some have excellent heat resistance at 250 ° C., but since the condensation type silicone adhesive reacts with water vapor in the air and cures at room temperature, it cures and exhibits adhesiveness. There is a problem in that it takes a long time to work, and a low-molecular weight compound generated during curing remains, vaporizes and adheres to the windshield after long-time lighting, and white fog occurs.

Therefore, the present inventors have previously found that, in order to solve these problems, an addition type silicone adhesive compounded with iron oxide is used to solve the above problems (Japanese Patent Application No. 2000-242242). No. 2-145846) has a problem that the iron oxide blended to impart heat resistance causes the appearance to be reddish-colored and the coated surface to be noticeably abnormal. Therefore, the development of an achromatic or fine-colored adhesive Was desired. Further, although the problem that the inner surface of the windshield becomes cloudy when the lamp is lit for a long time due to the volatilization of the low-molecular-weight siloxane has been largely solved, further improvement is desired.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems by providing a beam having an adhesive layer between the windshield and the mirror, which has excellent appearance and heat resistance and does not cause fog. Is to provide a lamp.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve this object, the present inventors have used an addition type adhesive containing a heat resistance improver and exhibiting an achromatic color or a faint color. As a result, it has been found that the problem can be solved and the appearance and characteristics of the beam lamp can be greatly improved, and the present invention has been completed.

That is, the beam lamp of the present invention is characterized in that the windshield is adhered by an achromatic or microchromatic addition reaction type silicone adhesive containing a heat resistance improver.

The addition type silicone adhesive used in the present invention is basically an achromatic or finely colored composition containing the following components and is cured to form an adhesive layer. (A) a polyorganosiloxane base polymer containing a vinyl group bonded to a silicon atom; (B) a polyorganohydrogensiloxane crosslinker containing a hydrogen atom bonded to a silicon atom; (C) a curing catalyst (D) adhesiveness An imparting agent; and (E) a heat resistance improver.

In addition to the above basic components, depending on the purpose,
Any filler, additive, etc. may be blended within a range that does not impair the achromatic or finely colored appearance.

The achromatic color includes transparent or translucent colorless, white, gray white, gray, gray black, black, etc.
It refers to a color tone that does not cause selective reflection of visible light of a specific wavelength, and a fine color is a color that, although accompanied by some other color, is in a range that does not matter in appearance and is ivory-based. , Light blue colors; white, gray white, gray, gray black, and black with reddish, greenish, yellowish, bluish, etc. are exemplified. From the viewpoint of the effect of the present invention, colorless or white to gray lightness is preferable.

Constituting Addition Type Silicone Adhesive (A)
The component polyorganosiloxane base polymer has at least two vinyl groups bonded to silicon atoms in one molecule. If the amount of vinyl groups in the molecule is less than 2, polyorganosiloxane that does not participate in crosslinking is formed, and the composition obtained by curing does not become a rubber-like elastic body. Of the organic groups bonded to the silicon atom of the polyorganosiloxane of (A), the groups other than the vinyl group include alkyl groups such as methyl, ethyl, propyl, and butyl; cycloalkyl groups such as cyclohexyl; phenyl groups; Substituted monovalent hydrocarbon groups such as chloromethyl group and trifluoropropyl group are exemplified, but it is easy to synthesize,
A methyl group is preferred because it is easy to handle the uncured state and the degree of polymerization of the polyorganosiloxane required to maintain good physical properties after curing is easily obtained. The polyorganosiloxane represented by (A) is preferably substantially linear because it is easy to synthesize, but in order to improve the mechanical properties, it may be partially or wholly branched. You may use what has a vinyl group at the terminal. From the workability of the composition before curing and the physical properties of the adhesive after curing, especially its mechanical strength, the viscosity at 25 ° C. is preferably in the range of 50 to 100,000 cSt.

The polyorganohydrogensiloxane crosslinking agent as the component (B) reacts with the vinyl group of the polyorganosiloxane as the component (A) to form a rubber-like cured product. In order to obtain a high molecular weight polysiloxane,
The component (B) must contain at least three hydrogen atoms bonded to silicon atoms in one molecule. Examples of the organic group bonded to the silicon atom include the same groups as the organic groups in the component (A) described above, but a methyl group is most preferable because of ease of synthesis. Moreover, an alkenyl group such as a vinyl group may be present. Such a polyorganohydrogensiloxane may have a linear, branched or cyclic siloxane skeleton, and
It may be a mixture of these. The blending amount of the component (B) is the vinyl group 1 of the polyorganosiloxane of the component (A).
The amount is preferably 0.5 to 4 hydrogen atoms bonded to silicon atoms in the component (B), and the weight ratio of both components is 0 relative to 100 parts by weight of the component (A). .01-
A range of 10 parts by weight is common. If the amount of hydrogen atoms in the component (B) is too large or too small, the cured adhesive will not have sufficient mechanical properties and thermal stability.

The curing catalyst of the component (C) is a catalyst used for an addition reaction between a vinyl group and a hydrosilyl group.
Examples of such a catalyst include platinum, rhodium, and palladium as a simple substance or a compound, but a platinum compound is preferable from the viewpoint of catalytic effect and easiness of work. Examples of the platinum compound include chloroplatinic acid and its alcohol solution, a complex of chloroplatinic acid and an alcohol, and a vinylsiloxane complex of chloroplatinic acid. A solution of chloroplatinic acid or a vinylsiloxane complex is desirable from the viewpoint of dispersibility. The blending amount of the component (C) is based on the total amount of the components (A) and (B).
An amount of 0.1 to 1000 ppm is preferable.

As the adhesiveness-imparting agent of the component (D), a silane derivative or a siloxane derivative having the following plural functional groups combined in the same molecule is preferable. Si-H bond and epoxy group; Si-H bond and alkoxy group, or in addition ester bond; Vinyl group and / or epoxy group and alkoxy group; Allyl group and alkoxy group; (Meth) acryloxy group and alkoxy group

Examples of compounds having these functional groups include compounds represented by the following formulas (I) to (VI).
However, in the formula, Me represents a methyl group.

[0016]

[Chemical 1]

[0017]

[Chemical 2]

The blending amount of the component (D) is 100 parts of the component (A).
The amount is preferably 0.001 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on parts by weight. If the amount of component (D) is too small, the adhesiveness of the composition will be insufficient and
Too much will adversely affect the properties of the cured adhesive.

The heat resistance imparting agent as the component (E) is the most characteristic component in the present invention, which maintains a good adhesive function even under severe conditions of use and suppresses the fog phenomenon. Further, due to the relationship that the silicone adhesive is achromatic or finely colored, there are restrictions on the hue. Examples of those having the function of imparting such heat resistance include additives that suppress the oxidation and thermal decomposition of polysiloxane in the silicone adhesive, and those that also function as a filler.

Examples of the former additive-like heat resistance imparting agent include inorganic cerium compounds such as cerium oxide and cerium hydroxide; cerium octanoate, cerium naphthenate,
Organic acid salts of transition metals such as lanthanum octanoate, mixed rare earth metal octanoate, iron octanoate, and iron naphthenate; and their complexes; Cerium-modified polysiloxane having: and M _x O _y
(In the formula, M is beryllium, magnesium, calcium,
Strontium, barium, indium, rare earth elements,
Represents chromium, molybdenum, tungsten or zinc;
x and y each represent the number corresponding to the valence of the metal element)
Composite iron oxide ferrite containing 1 to 50% by weight of the metal oxide portion represented by (Japanese Patent Application Laid-Open No. 53-58557).
And so on. The compounding amount of such an additive-like heat resistance imparting agent is 0.0 with respect to 100 parts by weight of the component (A).
A range of 01 to 10 parts by weight is preferable. Outside this range, the adhesive will not have sufficient heat resistance.

As an example of the heat resistance-imparting agent having the function of the latter filler, titanium oxide can be mentioned. In this case, the blending amount is 500 parts by weight or less, preferably 20 to 75 parts by weight, based on 100 parts by weight of the component (A). If this blending amount is too large, it becomes brittle and the mechanical strength and adhesive strength are impaired.

Of these heat resistance-imparting agents, cerium octanoate, iron octanoate and titanium oxide are preferable in terms of their effects. Titanium oxide, in addition to the effect of giving heat resistance to the adhesive, imparts good elongation to the adhesive after curing as a rubber-like elastic body, so that the adhesive layer can be applied to the adhesive layer due to the temperature change caused by turning on and off the beam lamp. It is particularly preferable because it has an effect of absorbing applied stress to prevent damage to the adhesive layer, and its high hiding power suppresses some coloring factors due to additives added for other purposes.

Such heat resistance imparting agents may be used alone or in combination of two or more.

A filler is generally added to the silicone adhesive of the present invention in order to impart mechanical strength as an elastic body after curing. As the filler, in addition to those which also serve as the heat resistance imparting agent shown as the component (E), fumed silica and precipitated silica which are generally used as a reinforcing filler for silicone rubber; ground quartz which is a non-reinforcing filler Examples thereof include calcium carbonate, alumina, zinc oxide, carbon black and the like. In the case of the reinforcing filler, it may be used as it is, or may be one which is hydrophobized by reacting the silanol group on the surface of the fine powder with cyclic polydimethylsiloxane, hexamethyldisilazane, or the like.
It is not preferable that such a low molecular weight organosilicon compound remains in the adhesive as it is for the reason described below. The compounding amount of the filler is 50 with respect to 100 parts by weight of the component (A).
It is 0 part or less, and in terms of mechanical strength and adhesive strength, it is 5 to 2
00 parts by weight is preferred.

In the present invention, in order to improve the function of the silicone adhesive as the adhesive of the beam lamp, the low molecular siloxane in the polysiloxane compounded as (A) and (B) in the adhesive, For example, it is preferable to lower the content of octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and the like. The content of the low-molecular-weight siloxane is preferably 1,000 ppm or less of the total amount of both components (A) and (B), and 30
It is more preferably 0 ppm or less. In order to reduce the content of the low molecular siloxane, it is general to reduce the content of the low molecular siloxane in the component (A) which is the base polymer. This has the effect of preventing fogging of the windshield and improving the adhesion.

The silicone adhesive used in the present invention can be hardened to form an adhesive layer by blending a predetermined amount of each of the above-mentioned components and mixing them uniformly. However, when components (A) to (C) are mixed, a crosslinking reaction occurs even at room temperature and the composition hardens. Therefore, at least one of these components is stored in a separate two-pack type and mixed immediately before use, By adding an addition reaction inhibitor such as a known ethylenically unsaturated isocyanurate such as allyl isocyanurate, it is stored as one package and used.

Next, an example of the structure and manufacturing method of the beam lamp of the present invention is shown in FIG.

First, the sealing portion (21) of a light source, for example, a halogen bulb (2) is inserted into the base portion (13) of the dichroic mirror (1), and the focus is adjusted to the inorganic cement (4). Then, it is filled so that air is not ventilated from the mouthpiece part (13), and heated and dried.

The uncured addition reaction type silicone adhesive (5) is applied to the flange portion (11) at the end of the dichroic mirror (1) with the light source (2), and the windshield (6) is applied to this portion. Put. Next, the mirror (1) and the windshield (6) are put in a heating furnace in a high temperature atmosphere of 200 to 250 ° C., the adhesive (5) is cured, and the mirror (1) and the windshield are mixed. (6) are fixed to each other.

After the above combination, the dichroic mirror (1) with the windshield (6) is taken out into the atmosphere (20 to 30 ° C.) and cooled. At this time, the internal pressure surrounded by the windshield (6) and the dichroic mirror (1) becomes lower than the outside air, and the outside air pressurizes the windshield (6) and the dichroic mirror (1) uniformly. Then, the beam lamp with a windshield can be obtained by pressing and adhering so that the thickness of the adhesive (5) becomes uniform.

[0031]

According to the present invention, by using an achromatic or light-colored addition reaction type silicone adhesive, there is no appearance problem for a wide range of use, and the adhesion between the windshield and the mirror. A beam lamp with a windshield in excellent condition can be obtained. Especially when the above-mentioned adhesive having a low content of low-molecular-weight siloxane is used,
It has excellent adhesiveness and can prevent fogging of the windshield.

[0032]

EXAMPLES The present invention will be described below with reference to examples. In addition, the part in a composition is a weight part and each measured value is a value in 25 degreeC. The invention is not limited by these examples.

Examples 1 to 7 of Table 1 are silicone compositions which cure to form an addition reaction type silicone adhesive layer.
And the compositions of Comparative Examples 1 to 4 were prepared by uniformly mixing the components. Of the ingredients of the composition,
As the components (A) to (D), those shown in Table 2 were used.

[0034]

[Table 1]

[0035]

[Table 2]

As shown in FIG. 2, these compositions were applied to the flange portion (11) of the dichroic mirror, and the windshield (6) was placed on the flange portion (1) and pressure-bonded at 180 ° C.
An adhesive (5) layer was formed by heating for 5 minutes for adhesion and curing, and a model of a beam lamp with a windshield having no light source portion was prepared and subjected to a practical test.

That is, this model was placed in a high temperature dryer at 270 ° C., and the appearance (cloudiness) and the adhesiveness under long-term heating were evaluated. For the evaluation of adhesiveness, compressed air of 5 kgf / cm ² was sent from the base of the beam lamp in the direction of the arrow.

Separately, the compositions of the above Examples and Comparative Examples were tested for shear adhesion. That is, according to the JIS K6850 test method, but 1 mm
Each composition was applied to an aluminum plate so as to have a sample thickness of, and heated at 180 ° C. for 15 minutes to be bonded and cured to prepare a test piece, and the shear adhesive strength was measured. The test was performed on the normal state and the one that was left in a constant temperature dryer at 270 ° C. for 100 hours and returned to normal temperature. The appearance of this sample was observed.

The above results are shown in Table 1. The adhesives of Comparative Examples 1, 2 and 4 show a remarkable decrease in shear adhesiveness after heating,
The results of the practical tests also show that the heat resistance of the adhesive is poor. The adhesive of Comparative Example 3 is superior in heat resistance to that, but has a practical limitation because it has a reddish brown appearance. On the other hand, the adhesives of Examples 1 to 7 according to the present invention have the advantages that they have higher heat resistance than any of these and exhibit an achromatic color from colorless translucent to black. Is shown in.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a beam lamp with a windshield showing an embodiment of the present invention.

FIG. 2 is a diagram showing a method for evaluating adhesive strength. The left side (excluding the base) is a sectional view.

[Explanation of symbols]

 1 Dichroic mirror 2 Light bulb (eg halogen lamp) 3 Terminal pin 4 Inorganic cement 5 Adhesive 6 Windshield 11 Dichroic mirror flange 12 Lens 13 Dichroic mirror base 21 Light bulb sealing

Claims (1)

[Claims] 1. A beam lamp, wherein a windshield is adhered with an achromatic or microcolored addition reaction type silicone adhesive containing a heat resistance improver.