JP2001167736A - Flash bulb - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flash bulb which is excellent in flexibility and explosion- proof characteristic of a cured coating film, does not result in generation of an environmental pollution substance even in acierated, further enabling the manufacturing time to be shortened. SOLUTION: On the outer surface of the bulb is formed a explosion preventing protection film consisting of a blend of an urethane (meth)acrylate resin (A), a reactive diluent (B), and a photopolymerization initiator (C). As the reactive diluent (B), there is used an ethylenic unsaturated compound (B1) which has one ethylenic unsaturated group per molecule and which has a glass transition temperature ranging from 80 to 160 deg.C when being present as a homopolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flash lamp,
More specifically, the present invention relates to a flash lamp having a protective film for preventing explosion or explosion of the lamp during the light emission.

[0002]

2. Description of the Related Art A flash light bulb has been conventionally used as a light source for photographing and the like, and is usually constructed by sealing a photosensitive material, oxygen and an appropriate ignition structure in a glass bulb. An extremely high-brightness flash can be generated by instantaneously burning the photosensitive material in the glass bulb. However, it is known that since the photosensitive material is instantaneously burned at the time of light emission, the glass bulb may explode or explode, which may cause inconvenience. An appropriate protective film is formed on the outer surface of the glass bulb.

For such a protective film, cellulose acetate has been used as a main component in the past, and vinyl chloride resin has been used at present. For example, JP-B-44-10436 and JP-B-46-34677 disclose a protective film formed by adding a predetermined amount of a plasticizer and a stabilizer to a predetermined amount of a vinyl chloride resin. It has been shown to be advantageous in terms of formation time and explosion resistance.

However, a protective film containing vinyl chloride as a main component is excellent in explosion resistance as described above and does not melt and emit stickiness after light emission. Since there is a risk of generating harmful substances, flash lamps having a protective film containing a vinyl chloride resin as a main component have a problem that, for example, there is a concern about environmental pollution due to incineration at the time of disposal.

[0005] Further, the formation time of a protective film mainly composed of a vinyl chloride resin can be formed in a shorter time than that of a protective film mainly composed of cellulose acetate. However, it was not yet satisfactory as a reduction in the manufacturing time of a flash bulb.

To solve such a problem, Japanese Patent Laid-Open No.
No. 47658, a urethane acrylate containing at least two reactive double bonds, a reactive diluent,
A transparent ultraviolet-curable resin film comprising a coating composition comprising a photopolymerization initiator and a sensitizer is disclosed in JP-A-7-94145.
In Japanese Patent Application Laid-Open No. 8-96775, a protective coating made of a urethane resin or a butadiene rubber material is proposed, and the present applicant also discloses a urethane (meth) acrylate resin and a reactive diluent. Was proposed.

[0007]

However, as a result of a detailed study by the present inventors, the above and the techniques disclosed in the publication do not discuss urethane acrylate or a reactive diluent in detail, nor do the techniques disclosed in the publication. In technology,
Although the physical properties of the coating film as a protective film for a flash lamp are satisfactory to some extent, subsequent studies have revealed that there is still room for improvement in the flexibility of the coating film. Therefore, in the present invention, in such a background, the cured film has excellent flexibility and explosion resistance, does not generate substances that cause environmental pollution even when burned, and can further reduce the manufacturing time. It is an object of the present invention to provide a flash lamp that can be used. Further, in the present invention, the resistance to piercing by glass fragments can be improved.

[0008]

Means for Solving the Problems However, the present inventors have conducted intensive studies in view of such circumstances, and as a result, have found that urethane (meth) acrylate resin (A) and reactive diluent (B)
And a photopolymerization initiator (C). The reactive diluent (B) has one ethylenically unsaturated group per molecule, and has a glass transition temperature of a homopolymer. An ethylenically unsaturated compound (B
The inventor has found that a flash lamp in which a rupture prevention protective film using the method 1) is formed on the outer surface of the bulb meets the above object, and the present invention has been completed.

In the present invention, as the reactive diluent (B),
Furthermore, the glass transition temperature of a single polymer having one ethylenically unsaturated group and a homopolymer of −10 is obtained.
When the ethylenically unsaturated compound (B2) having a temperature of ６０60 ° C. is used, the effects of the present invention are remarkably exhibited. Further, as a reactive diluent (B), an ethylenically unsaturated compound (B) having 2 to 6 ethylenically unsaturated groups per molecule.
It is also preferable to use 3).

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The flash light bulb of the present invention, on the outer surface of the bulb glass bulb,
A rupture prevention protective film is formed, wherein the rupture prevention protective film comprises a urethane (meth) acrylate resin (A),
A composition obtained by blending a reaction diluent (B) and a photopolymerization initiator (C) is applied to the outer surface of a glass bulb of a light bulb and cured by ultraviolet irradiation. The urethane (meth) acrylate resin (A) used in the present invention is not particularly limited, but is preferably a urethane (meth) acrylate resin obtained by reacting a polyol, a polyisocyanate, and hydroxy (meth) acrylate.

The polyol is not particularly limited and includes, for example, ethylene glycol, propylene glycol, butylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methylpentanediol, neopentyl glycol, Cyclohexanedimethanol, hydrogenated bisphenol A, polycaprolactone, trimethylolethane, trimethylolpropane, polytrimethylolpropane, pentaerythritol, polypentaerythritol, sorbitol, mannitol, glycerin, polyglycerin, diethylene glycol, triethylene glycol, tetraethylene glycol , Dipropylene glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetra Polyhydric alcohols such as tylene glycol, and maleic anhydride, maleic acid, fumaric acid, itaconic anhydride, itaconic acid, adipic acid, polyester polyols that are condensates with polybasic acids such as isophthalic acid, Caprolactone-modified polyol,
Polyolefin-based polyols, polybutadiene-based polyols, ethylene oxide and / or propylene oxide block copolymerized polyols, ethylene oxide and / or propylene oxide random polyols, and the like can be given. Among them, polypropylene glycol, ethylene oxide and / or propylene oxide random polyol are preferably used.

The polyisocyanate is not particularly restricted but includes, for example, aromatic, aliphatic, cycloaliphatic and alicyclic polyisocyanates. Among them, tolylene diisocyanate (TDI), Diphenylmethane diisocyanate (MDI), hydrogenated diphenylmethane diisocyanate (H-MDI), polyphenylmethane polyisocyanate (crude MDI), modified diphenylmethane diisocyanate (modified MDI), hydrogenated xylylene diisocyanate (H-XDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), trimethylhexamethylene diisocyanate (TMXDI), tetramethylxylylene diisocyanate (m-TMXDI), isophorone diisocyanate ( PDI), norbornane diisocyanate (NBDI), 1,3-bis (isocyanatomethyl) cyclohexane (H ₆ XDI) polyisocyanate or trimer compounds of these polyisocyanates, such as,
Reaction products of these polyisocyanates and polyols are preferably used.

Further, the hydroxy (meth) acrylate is not particularly restricted but includes, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, -Hydroxyethylacryloyl phosphate, 4-butylhydroxy (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxypropylphthalate, glycerin di (meth) acrylate, 2-hydroxy-3-acryloyloxypropyl (meth) ) Acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, caprolactone-modified 2-hydroxyethyl (meth) acrylate, and the like. Le (meth) acrylate, 2-hydroxypropyl (meth) acrylate is preferably used.

The method for producing the urethane (meth) acrylate resin (A) is not particularly limited as long as it is a method of reacting a polyol, a polyisocyanate, and hydroxy (meth) acrylate, and a known method is employed. For example, a method in which three components of polyol, polyisocyanate, and hydroxy (meth) acrylate are mixed and reacted at once, a urethane isocyanate intermediate containing one or more isocyanate groups per molecule by reacting polyol and polyisocyanate. Reacting the intermediate with hydroxy (meth) acrylate after forming a polyisocyanate, a polyisocyanate and hydroxy (meth) acrylate
A method of reacting an acrylate to form a urethane (meth) acrylate intermediate containing one or more isocyanate groups per molecule and then reacting the intermediate with a polyol may be used. The method in terms of time reduction is preferred.

For example, after reacting a polyol and a polyisocyanate at a reaction molar ratio of 1: 2 (theoretical value) (an error of about several% is allowable in actual preparation),
If necessary, a polyol may be further added to the reaction product by n: n-
1 (n is an integer of 2 or more) (theoretical value), and the reaction product is further reacted with hydroxy (meth) acrylate at a ratio of 1: 2 (theoretical value) (approximately several% in actual charging). It is preferable to carry out the reaction at a reaction molar ratio of In the above reaction, it is also preferable to use a catalyst such as dibutyltin dilaurate for the purpose of accelerating the reaction.

Thus, the urethane (meth) acrylate resin (A) is obtained. In the present invention, the urethane (meth) acrylate resin is used.
The acrylate resin (A) preferably has a weight average molecular weight in terms of standard polystyrene molecular weight of 800 to 30,000, and more preferably 1600 to 1.
When the weight average molecular weight is less than 800, the protective film is likely to be broken or broken at the time of light emission.
If it exceeds, stickiness of the surface of the protective film is likely to occur, which is not preferable.

The weight-average molecular weight in terms of standard polystyrene molecular weight is defined as high-performance liquid chromatography ("Showex GPC system-1" manufactured by Showa Denko KK).
Type 1 "), column: Shodex GPC KF-8
06 L (exclusion limit molecular weight: 2 × 10 ⁷ , separation range: 10
0 to 2 × 10 ⁷ , theoretical plate number: 10,000 stages / unit, filler material: styrene-divinylbenzene copolymer, filler particle size: 10 μm). .

Further, the urethane (meth) acrylate resin (A) preferably has 2 to 6 (meth) acryloyl groups per molecule. If the number of the (meth) acryloyl groups is less than 2, stickiness after curing by irradiation with ultraviolet rays occurs, and the film strength becomes extremely low. If it exceeds 6, the elongation of the film after curing with ultraviolet rays is sufficient. This is not preferable because the glass is liable to be scattered when the glass is broken in the case of a flash bulb.

The urethane (meth) acrylate resin (A) obtained above has an elastic modulus after curing of 100 to 100.
Is preferably 2,000 kg / cm ^2, more preferably 200~1,000kg / cm ^2, particularly preferably 350~800kg / cm ^2. If the elastic modulus is less than 100 kg / cm ² , the resistance of the coating to piercing breakage by the projections becomes weak, and 2,000 kg / c 2
If it exceeds m ² , it is difficult to follow abrupt deformation, and the coating tends to break, which is not preferable.

The above-mentioned elastic modulus after curing means that a urethane (meth) acrylate resin (A) is applied on a polyethylene terephthalate film (thickness: 100 μm) using a 125 μm doctor blade, and a high-pressure mercury lamp of 80 W / cm ² is applied. Is the elastic modulus after curing at a line speed of 5 m / min at a distance of 18 cm from the substrate (ultraviolet integrated light amount of 365 nm is 230 mJ / cm ² ).
The elastic modulus is measured according to JIS K7127.

The reactive diluent (B) has a glass transition temperature (Tg) of 80 to 160 when it has one ethylenically unsaturated group per molecule and is a homopolymer.
An ethylenically unsaturated compound (B1) having a temperature of ° C. is used. When the glass transition temperature (Tg) is less than 80 ° C., the elasticity of the cured film due to the irradiation of ultraviolet rays becomes low, the film becomes sticky and the strength of the film becomes low. No longer
When the glass is broken, the glass is easily scattered, and the effect of the present invention is not exhibited.

The ethylenically unsaturated compound (B1) is not particularly limited as long as it is within the above glass transition temperature (Tg). For example, dicyclopentanyl acrylate (Tg: 120 ° C., for example, Hitachi "Fancryl FA-513A" manufactured by Kasei Kogyo Co., Ltd., dicyclopentenyl acrylate (Tg: 120C, for example, "Fancryl FA-511A" manufactured by Hitachi Chemical Co., Ltd.), isobonyl acrylate (Tg: 94C, e.g., Kyoeisha Chemical Co., Ltd., “Light Acrylate IB-XA”), acryloyl morpholine (Tg: 145 ° C., for example, Kojin Co., Ltd.)
“ACMO”). Among them, acryloylmorpholine is preferably used.

In the present invention, the reactive diluent (B) further has one ethylenically unsaturated group per molecule, and has a glass transition temperature (Tg) of-when it is a homopolymer. The combined use of the ethylenically unsaturated compound (B2) at 10 to 60 ° C can be performed at room temperature (10 to 40
C) is low in that the viscosity is kept low. If the glass transition temperature (Tg) of the ethylenically unsaturated compound (B2) used in combination is less than -10 ° C, stickiness of the cured film occurs, and the film strength is lowered, and if it exceeds 60 ° C, elongation of the cured film is sufficient. It is not preferable because the glass is easily scattered when the glass is broken.

The ethylenically unsaturated compound (B2) is not particularly limited as long as it is within the above-mentioned glass transition temperature (Tg). For example, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, -Hydroxypropyl methacrylate, phenol ethylene oxide modified (n = 2) acrylate, 2
-Hydroxy-3-phenoxypropyl acrylate,
Nonylphenol propylene oxide modification (n = 2.
5) Acrylate, glycidyl methacrylate, lauryl acrylate, n-butyl methacrylate, n-stearyl methacrylate, benzyl methacrylate, and the like. Among them, lauryl acrylate, phenol ethylene oxide modified (n = 2) acrylate, nonylphenol propylene oxide modified (n = 2.5)
Acrylate and 2-hydroxy-3-phenoxypropyl acrylate are preferably used.

The glass transition temperature (Tg) is a glass transition temperature (Tg) when the ethylenically unsaturated compound (B1) or (B2) is a homopolymer, and is measured as follows.

The ethylenically unsaturated compound is poured into a rubber mold, and a glass plate (1 mm) and a polyethylene terephthalate (PET) film (50 mm) are placed immediately under a UV lamp.
μm) UV irradiation from the front and back sides for 30 seconds each from the front side, the glass plate and the PET film were peeled off, and the cured product was directly irradiated with UV light for 2 minutes from the front side and back side,
A fully cured sample was used as a measurement sample, and a differential scanning calorimeter (DSC220 type, manufactured by Seiko Denshi Kogyo KK) was used.
C) Using a device, in a nitrogen stream, the temperature was raised at a rate of 10 ° C./min.
The inflection point of the DSC curve was defined as the glass transition temperature.

The UV irradiation conditions are as follows. Apparatus: UV irradiation unit U, manufactured by Eye Graphics Co., Ltd.
E32-5B Light source: 60 W / cm parallel high-pressure mercury lamp (having a parabolic reflector and emitting parallel light) Height of light source: 30 cm UV peak intensity: 30 mW / cm ² Standard coating thickness 1 mm As a photoinitiator, benzyldimethyl ketal was used in an amount of 1% by weight based on the ethylenically unsaturated compound.

In the present invention, the use of an ethylenically unsaturated compound (B3) having 2 to 6 ethylenically unsaturated groups per molecule in combination with the reactive diluent (B) by ultraviolet irradiation is also preferred. It is preferable in that the elastic modulus is improved without lowering the elongation of the cured film.

The ethylenically unsaturated compound (B3) is not particularly restricted but includes, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, di (meth) acrylate of other ethylene glycol oligomers, propylene Glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, other di (meth) acrylates of propylene glycol oligomer, 1,6-hexanediol di (meth) acrylate, other di (meth) acrylate, trimethylol Propane tri (meth) acrylate, pentaerythritol tri (meth)
Acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like can be mentioned. Among them, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate are preferably used.

When only the ethylenically unsaturated compound (B3) is used as the reactive diluent (B), the elongation at break of the cured film due to the irradiation of ultraviolet rays is remarkably reduced, and the externally applied to the bulb-coated product is reduced. Since the film cannot easily follow the deformation due to the stress, and the film is easily broken, the effect of the present invention is not exhibited.

In the present invention, as described above, the reaction diluent (B)
Is preferably used as the ethylenically unsaturated compound (B1), and more preferably an ethylenically unsaturated compound (B2) and / or
Alternatively, an ethylenically unsaturated compound (B3) is used in combination. The mixing amount of the reactive diluent (B) is 30 to 220 parts by weight based on 100 parts by weight of the urethane (meth) acrylate resin (A).
Parts by weight, more preferably 50 to 1 parts by weight.
It is 50 parts by weight, particularly preferably 81 to 130 parts. If the amount is less than 30 parts by weight, the viscosity of the mixture becomes high at room temperature, making it difficult to coat the bulb. If the amount exceeds 220 parts by weight, the viscosity of the mixture becomes low at room temperature, and the amount of the mixture applied to the bulb ( Thickness) is undesirably difficult to control.

The amount of the ethylenically unsaturated compound (B1) is 100 parts by weight of the urethane (meth) acrylate resin (A).
The amount is preferably from 25 to 100 parts by weight, particularly preferably from 35 to 60 parts by weight, and the compounding amount of the ethylenically unsaturated compound (B2) is from 5 to 100 parts by weight, particularly preferably from 45 to 100 parts by weight. And the amount of the ethylenically unsaturated compound (B3) is 0 to 20 parts by weight, preferably 1 to 10 parts by weight. If the amount of the ethylenically unsaturated compound (B1) is less than 25 parts by weight, the cured film will be sticky and the film strength will be low. If it exceeds 100 parts by weight, the elongation of the cured film will be insufficient, which is not preferable.
If the amount of the ethylenically unsaturated compound (B2) is less than 5 parts by weight, the cured film will not have sufficient elongation, and if it exceeds 100 parts by weight, the cured film will be sticky and the film strength will be undesirably low. If the amount of the ethylenically unsaturated compound (B3) is more than 20 parts by weight, the cured film will not have sufficient elongation and the glass will be easily scattered when the glass is broken, which is not preferable.

The photopolymerization initiator (C) used in the present invention is not particularly limited, and known photopolymerization initiators can be used. For example, P, P'-bis (dimethylamino) benzophenone, P, P'-bis (diethylamino) benzophenone, P, P'-bis (dibutylamino) benzophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin phenyl ether, benzoin isobutyl ether, Benzoylbenzoic acid, methyl benzoylbenzoate,
Benzyldiphenyl disulfide, benzyldimethyl ketal, dibenzyl, diacetyl, anthraquinone, naphthoquinone, 3,3′-dimethyl-4-methoxybenzophenone, benzophenone, dichloroacetophenone,
2-chlorothioxanthone, 2-methylthioxanthone, 2,4-diethylthioxanthone, 2,2-diethoxyacetophenone, 2,2-dichloro-4-phenoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, phenylglyoxylate, α- Hydroxyisobutylphenone, dibenzosparone, 1- (4-
Isopropylphenyl) -2-hydroxy-2-methyl-1-propanone, 2-methyl- [4- (methylthio)
Phenyl] -2-morpholino-1-propanone, tribromophenylsulfone, tribromomethylphenylsulfone.

Further, 2,4,6- [tris (trichloromethyl)]-1,3,5-triazine, 2,4- [bis (trichloromethyl)]-6- (4'-methoxyphenyl) -1 , 3,5-Triazine, 2,4- [bis (trichloromethyl)]-6- (4'-methoxynaphthyl)-
1,3,5-triazine, 2,4- [bis (trichloromethyl)]-6- (piperonyl) -1,3,5-triazine, 2,4- [bis (trichloromethyl)]-6
Triazine derivatives such as (4'-methoxystyryl) -1,3,5-triazine, acridine derivatives such as acridine and 9-phenylacridine, 2,2'-bis (o-
(Chlorophenyl) -4,5,4 ', 5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis (o-
(Chlorophenyl) -4,5,4 ', 5'-tetraphenyl-1,1'-biimidazole, 2,2'-bis (o-
Fluorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,1′-biimidazole, 2,2′-bis (o
-Methoxyphenyl) -4,5,4 ', 5'-tetraphenyl-1,1'-biimidazole, 2,2'-bis (p-methoxyphenyl) -4,5,4', 5'-tetra Phenyl-1,1′-biimidazole, 2,4
2 ', 4'-bis [bi (p-methoxyphenyl)]-
5,5′-diphenyl-1,1′-biimidazole,
2,2′-bis (2,4-dimethoxyphenyl) -4,
5,4 ′, 5′-diphenyl-1,1′-biimidazole, 2,2′-bis (p-methylthiophenyl) -4,
5,4 ', 5'-diphenyl-1,1'-biimidazole, bis (2,4,5-triphenyl) -1,1'-biimidazole and the like and disclosed in JP-B-45-37377. Hexaarylbiimidazole derivatives such as tautomers covalently bonded at 1,2′-, 1,4′- and 2,4′-, triphenylphosphine, and 2-
Benzoyl-2-dimethylamino-1- [4-morpholinophenyl] -butane and the like can be mentioned.

The compounding amount of the photopolymerization initiator (C) is 1 to 20 parts by weight based on 100 parts by weight of the total of the urethane (meth) acrylate resin (A) and the reactive diluent (B). Is preferred, more preferably 2 to 10 parts by weight,
Particularly preferably, it is 3 to 10 parts by weight. When the amount is less than 1 part by weight, curing by ultraviolet irradiation does not proceed in a short time and the film strength is low. When the amount exceeds 20 parts by weight, the cured film is brittle and does not elongate.

Further, in the present invention, the glass transition temperature after curing of the composition comprising the urethane (meth) acrylate resin (A), the reactive diluent (B) and the photopolymerization initiator (C) is 10%. To 120 ° C, more preferably 15 to 100 ° C, particularly preferably 20 to 80 ° C. If the glass transition temperature is less than 10 ° C., the surface of the cured film at room temperature becomes sticky and the feel is poor, and the film strength is further lowered. Unsatisfactory deformation cannot be followed and glass fragments are scattered, which is not preferable.
The glass transition temperature of such a composition after curing is determined by the compounding amount of the urethane (meth) acrylate resin (A), the ethylenically unsaturated compound (B1), the ethylenically unsaturated compound (B2), and the ethylenically unsaturated compound (B3). Is adjusted to the above range by adjusting.

Further, in the present invention, in addition to the urethane (meth) acrylate resin (A), the reactive diluent (B) and the photopolymerization initiator (C), the coloring agent (D) is used in combination with the urethane (meth) acrylate resin. (A) 0.01 to 100 parts by weight
5 parts by weight, preferably 0.02 to 2 parts by weight, and the coloring agent (D) is a dye-based coloring agent, for example, C.I. I. Solvent Yellow 21 and a mixture of methyl ethyl ketone, “VALIOSOL YELLOW MYE” manufactured by Orient Chemical Industries, and the like. Further, if necessary, additives such as an antifoaming agent, a surfactant, and a leveling agent can be blended.

Thus, in the present invention, the urethane (meth) acrylate resin (A), the reactive diluent (B) (the ethylenically unsaturated compound (B1), or the ethylenically unsaturated compound (B1) and the ethylenically unsaturated compound (B2) and / or the ethylenically unsaturated compound (B3)) and the photopolymerization initiator (C) are blended to obtain a rupture prevention protective film material.

Next, a method of manufacturing a flash lamp according to the present invention will be described (see FIG. 1). FIG. 1 is a front view including a partial cross section showing an embodiment of a flash lamp according to the present invention.

In FIG. 1, a light emitting material 2 that emits high-intensity light by burning instantaneously inside a glass bulb 1 and a glass bulb that forms an ignition structure for igniting and burning the light emitting material 2 The introduced metal wire 3 and the ignition coil 4 having a thermal expansion coefficient equal to or approximately equal to 1 and oxygen 5 for assisting the burning of the luminescent material 2 are sealed, and the base 6 is connected to the ignition coil 4 via the introduced metal wire 3. To provide ignition energy.

A material for preventing a rupture, comprising a urethane (meth) acrylate resin (A), a reactive diluent (B) and a photopolymerization initiator (C), is applied to the outer surface of a glass bulb of a flash lamp. After coating, the coating is cured by irradiation with ultraviolet light to form a rupture prevention protective film on the outer surface of the flash lamp.

For such a coating, a rupture-preventing protective film material may be applied directly to the outer surface of the glass bulb of the flash lamp. However, from the viewpoint of workability, the flash lamp is placed with the base of the glass bulb of the flash lamp facing upward. The bulb is immersed in the rupture-preventing protective film material up to its base portion, for example, 20-30.
It is preferable that the coating be performed after draining for two seconds.

When irradiating with ultraviolet light, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a chemical lamp, or the like is used as a light source, and 100 to 500 mJ, preferably 150 to 300 mJ.
Irradiation is preferably performed at an integrated irradiation amount of J. In the irradiation, it is preferable to perform irradiation uniformly from six directions, that is, up and down and four sides of the bulb.

The thickness of the rupture-preventing protective film after the irradiation with ultraviolet rays cannot be specified unconditionally, but is preferably from 0.2 to 2.0 mm, more preferably from 0.5 to 1.3 mm.
Particularly preferably, it is 0.8 to 1.0 mm. If the film thickness is less than 0.2 mm, the glass cannot be tolerated by glass breakage at the time of flash light emission and is easily broken. If the film thickness exceeds 2.0 mm, the amount of light emission is reduced due to light absorption by the film.

Thus, the flash lamp of the present invention is obtained, which is free from odor and stickiness, can shorten the formation time, is excellent in explosion resistance, is excellent in flexibility, and has resistance to piercing by glass fragments. Is improved,
Even if it is incinerated at the time of its disposal, it does not generate chlorine or dioxin, resulting in a flash bulb that does not cause environmental pollution.

[0046]

The present invention will be specifically described below with reference to examples. In the examples, “%” and “parts” mean on a weight basis unless otherwise specified.

Urethane (meth) acrylate resin (A-
After introducing air gas into a reaction vessel equipped with a stirrer, a thermometer, a cooling pipe and an air gas introducing pipe of 1) , 2,4-tolylene diisocyanate ("TDI-
100 "), 4.0 mol of neopentyl glycol (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 2.0 mol of the same.
After adding 1.0 mol of “PP-2000”) and reacting,
-2.05 mol of hydroxyethyl acrylate, 0.4 part of hydroquinone monomethyl ether, and dibutyltin dilaurate (manufactured by Tokyo Fine Chemical Company, "LIO
I ") A reaction was carried out by uniformly dropping 0.01 part of the mixed liquid over 3 hours. After completion of the dropwise addition, the reaction was continued for about 5 hours, and the disappearance of the isocyanate was confirmed. The reaction was terminated to obtain a urethane (meth) acrylate resin (A-1) (resin content: 98%, weight average molecular weight: 10). 000, elastic modulus:
490 kg / cm ² ).

The urethane (meth) acrylate resin (A-
2) Production After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 2,4-tolylene diisocyanate (Nippon Polyurethane Co., Ltd., “TDI
-100 ") 4.0 mol, neopentyl glycol (Mitsubishi Gas Chemical Co., Ltd.) 2.0 mol was charged, the temperature was raised to 70 ° C., and reaction was carried out. Further, ethylene oxide / propylene oxide random copolymer polyol (Asahi Denka Co., Ltd.) , "PR-
3007 ") and reacted after adding 2.0 mol of 2-hydroxyethyl acrylate, 0.4 part of hydroquinone monomethyl ether, and dibutyltin dilaurate (" LIOI ", manufactured by Tokyo Fine Chemical Co., Ltd.)
A reaction was carried out by uniformly dropping 0.01 part of the mixed liquid over 3 hours. After completion of the dropwise addition, the reaction was continued for about 5 hours, and the disappearance of the isocyanate was confirmed. The reaction was terminated to obtain a urethane (meth) acrylate resin (A-2) (resin content: 98).
%, Weight average molecular weight: 10,000, elastic modulus: 210 k
g / cm ² ).

Example 1 A rupture prevention protective film material having the following composition was prepared.・ Urethane (meth) acrylate resin (A-1) 51.85 parts ・ Acryloylmorpholine (B1) 22.22 parts (Okinin Co., Ltd., “ACMO”, glass transition temperature (Tg): 145 ° C.) Hydroxy-3-phenoxypropyl acryle 22.22 parts (B2) (manufactured by Toagosei Co., Ltd., “Aronix M-5710”, glass transition temperature (Tg): 17 ° C.) ・ Pentaerythritol triacrylate (B3) 70 parts (Osaka Organic Chemical Industry Co., Ltd., "Biscoat # 300")-1-hydroxycyclohexyl phenyl ketone (C) 3.0 parts (Ciba Specialty Chemicals, Inc., "Irgacure 184")-Methyl benzoylbenzoate (C) 1.5 copies (manufactured by Takahata Sangyo Co., Ltd., "OBM")

The following evaluation was performed on the obtained protective film material. (Tear strength) polyethylene terephthalate (PET)
After applying the above-mentioned protective film material on a film (thickness of 100 μm) using a doctor blade with a gap of 500 μm, a line speed of 5 m / min was passed under a high-pressure mercury lamp installed at a height of 18 cm from the conveyor belt. At a time (integrated light amount of 180 mJ / cm ² ), and cured to form a protective film. Regarding the protective film, JIS K
According to the tear test 6301, tear dumbbell B
Prepare a sample by die punching, 20 ° C, 65% R
Under H atmosphere, distance between chucks 70mm, pulling speed 200
A tear test was performed under the condition of mm / min, and a tear strength was measured.

(Young's modulus, breaking strength, breaking elongation) 100
The protective film material was applied on a polyethylene terephthalate (PET) film having a gap of 125 μm using a doctor blade having a gap of 125 μm, and then 18 c from a conveyor belt.
5m / m under a high-pressure mercury lamp installed at a height of 5m
1 pass at a line speed of in (integrated light amount 90m
J / cm ² ) and cured to form a protective film. With respect to the protective film, a strip-shaped test piece having a width of 15 mm and a length of 100 mm was prepared, and a tensile test was performed under the conditions of 20 ° C. and 65% RH, a distance between chucks of 25 mm and a tensile speed of 10 mm / min. The rate (strength at 1% elongation), breaking strength, and breaking elongation were measured.

(Pencil hardness) A gap of 50 μm is formed on a glass plate.
Apply the above protective film material using a doctor blade.
After that, it was installed at a height of 18 cm from the conveyor belt
5m / min line speed under high pressure mercury lamp
Pass once (integrated light amount 90mJ / cm ^Two), Cured
Then, a protective film was formed. Regarding the protective film, JIS K
 The pencil hardness was measured according to 5400.

Further, the above-mentioned protective film material was coated on a flash lamp, and 5 m / m ² under a high-pressure mercury lamp of 80 W / cm ² output installed at a height of 18 cm from the conveyor belt.
At a line speed of min, irradiation was performed once in each of the upper, lower, and four directions, and the light was passed through a total of six times to produce a flash lamp having a 1.0 mm protective film formed on the outer surface of the lamp.
The flash lamp used was the one shown in FIG.

The following evaluation was performed on the obtained flash lamp. (Crack resistance of protective film) The obtained flash lamp was subjected to a light emission test and evaluated according to the following criteria.・ ・ ・: No crack in the protective film was observed. X: Cracking of the protective film was observed.

(Protrusion of glass shards) After a light emission test of the obtained flash lamp was performed, a stepping test of the lamp was performed, and the evaluation was made based on the following criteria.・ ・ ・: There was no projection of the glass. X: Glass jumping out was observed. (Stackiness of Protective Film) The obtained flash lamp was subjected to a touch test using an index finger.

Example 2 In Example 1, the urethane (meth) acrylate resin (A-1) was replaced with the urethane (meth) acrylate resin (A-
Except having changed to 2), it carried out similarly and evaluated similarly to Example 1.

Example 3 The procedure of Example 1 was repeated, except that the composition of the protective film for rupture prevention was changed to the following composition.・ Urethane (meth) acrylate resin (A-1) 55.25 parts ・ Acroylmorpholine (B1) 25.25 parts (manufactured by Kojin Co., Ltd., “ACMO”, glass transition temperature (Tg): 145 ° C.) -Hydroxy-3-phenoxypropyl acrylate 19.0 parts (B2) (manufactured by Toagosei Co., Ltd., "Aronix M-5710", glass transition temperature (Tg): 17 ° C)-Pentaerythritol triacrylate (B3) 4.2 parts (“Biscoat # 300” manufactured by Osaka Organic Chemical Industry Co., Ltd.) 3.0 parts of 1-hydroxycyclohexyl phenyl ketone (C) (“Irgacure 184” manufactured by Ciba Specialty Chemicals) ・ Methyl benzoylbenzoate (C 1.5 parts (manufactured by Takahata Sangyo Co., Ltd., "OBM")-Colorant (D) 0.05 parts (manufactured by Orient Chemical Co., Ltd. VALIOSOL YELLOW MYE ")

Comparative Example 1 The procedure of Example 1 was repeated, except that the composition of the protective film for rupture prevention was changed to the following composition.・ 80 parts of urethane (meth) acrylate resin (A-1) ・ 20 parts of dipentaerythritol hexaacrylate (B) (manufactured by Nippon Kayaku Co., Ltd., “DPHA”, glass transition temperature (Tg): 250 ° C. or more) ・ 1- 0.4 parts of hydroxycyclohexyl phenyl ketone (C) (Irgacure 184, manufactured by Ciba Specialty Chemicals)

Comparative Example 2 The procedure of Example 1 was repeated, except that the composition of the protective film for rupture prevention was changed to the following composition. 50 parts of urethane (meth) acrylate resin (A-1) 50 parts of tripropylene glycol diacrylate (B) (manufactured by Osaka Organic Chemical Industry Co., Ltd., “Biscoat # 310HP”, glass transition temperature (Tg): 90 ° C.) 0.4 parts of 1-hydroxycyclohexyl phenyl ketone (C) (“Irgacure 184” manufactured by Ciba Specialty Chemicals)

Comparative Example 3 The procedure of Example 1 was repeated, except that the composition of the protective film for rupture prevention was changed to the following composition. -Urethane (meth) acrylate resin (A-1) 40 parts-Isobutylene acrylate (B) 60 parts (manufactured by Osaka Organic Chemical Industry Co., Ltd., "AIB", glass transition temperature (Tg): -26C)-1-hydroxycyclohexyl 0.4 parts of phenyl ketone (C) (“Irgacure 184” manufactured by Ciba Specialty Chemicals) The results of the examples and comparative examples are shown in Tables 1 and 2.

[Table 1] Glass tearing Young's modulus Breaking Breaking Pencil transfer temperature Strength Strength Elongation Hardness (° C) (kg / cm ² ) (kg / cm ² ) (kg / cm ² ) (%) Example 1 40 45 4100 180 70 2B 〃 225 37 3800 210 110 5B ３ 344 50 4300 250 60 B Comparative Example 1 250 or more 5 32000 980 5.4H 〃 2 250 or more 12 11000 520 13 H ３ 3025 30 70 100 100 B

[Table 2] Cracking resistance of protective film of glass fragments of protective film Projection condition Stickiness Example 1 ○ ○ None ○ 2 ○ ○ None 3 ○ ○ None Comparative Example 1 ○ × None × 2 ○ × None〃 3 × × Available

[0063]

The flash lamp of the present invention has no odor or stickiness, can shorten the formation time, is excellent in explosion resistance, is excellent in flexibility, and has resistance to piercing by glass fragments. It shows an improved effect, and does not generate chlorine or dioxin even if it is incinerated at the time of disposal, and is a flash lamp that does not cause environmental pollution, and is highly expected.

[Brief description of the drawings]

FIG. 1 is a front view including a partial cross section showing an embodiment of a flash lamp according to the present invention.

[Description of Signs] 1 ... Glass bulb 2 ... Luminescent material 3 ... Introduced metal wire 4 ... Ignition coil 5 ... Oxygen 6 ... Base 7 ... Rupture prevention protective film

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Shoji Aoki 1-88, Oyodonaka, Kita-ku, Osaka-shi Nippon Gosei Chemical Industry Co., Ltd. No. 95 West Electric Co., Ltd. F term (reference) 4J027 AG02 AG03 AG04 AG13 AG14 AG23 AG24 BA07 BA20 BA21 BA23 BA26 BA28 CC04 CD08 CD10

Claims (9)

[Claims] 1. A mixture comprising a urethane (meth) acrylate resin (A), a reactive diluent (B) and a photopolymerization initiator (C), and one reactive diluent (B) per molecule. A protective film made of an ethylenically unsaturated compound (B1) having an ethylenically unsaturated group and having a glass transition temperature of 80 to 160 ° C. when formed into a homopolymer is provided on the outer surface of the electric bulb. A flash lamp characterized by being formed. 2. The reactive diluent (B) which further has one ethylenically unsaturated group per molecule and has a glass transition temperature of -10 to 60 ° C. in the case of a homopolymer. The flash lamp according to claim 1, wherein the unsaturated unsaturated compound (B2) is used. 3. The reactive diluent (B) further comprising an ethylenically unsaturated compound (B3) having from 2 to 6 ethylenically unsaturated groups per molecule. Flashlight as described. 4. The urethane (meth) acrylate resin (A) having a weight average molecular weight of 800 to 30,000 in terms of standard polystyrene molecular weight and having 2 to 6 (meth) acryloyl groups per molecule. The flash lamp according to any one of claims 1 to 3, wherein a (meth) acrylate resin is used. 5. The urethane (meth) acrylate resin (A) has an elastic modulus of 100 to 2,000 k after curing.
The flash lamp according to any one of claims 1 to 4, wherein a urethane (meth) acrylate resin having a g / cm < ² > ratio is used. 6. A glass transition temperature after curing of a compound comprising a urethane (meth) acrylate resin (A), a reactive diluent (B) and a photopolymerization initiator (C).
The flash lamp according to any one of claims 1 to 5, wherein the temperature is 120 ° C. 7. A reactive diluent (B) is added to 100 parts by weight of the urethane (meth) acrylate resin (A).
The flash lamp according to any one of claims 1 to 6, wherein 0 to 220 parts by weight and 1 to 20 parts by weight of the photopolymerization initiator (C) are blended. 8. An ethylenically unsaturated compound (B1) of 25 to 100 parts by weight and an ethylenically unsaturated compound (B2) of 5 to 100 parts by weight based on 100 parts by weight of the urethane (meth) acrylate resin (A). The flash lamp according to any one of claims 1 to 7, further comprising 0 to 20 parts by weight of an ethylenically unsaturated compound (B3). 9. The flash lamp according to claim 1, further comprising a coloring agent (D).