JPH09194797A - Flame-retardant photopolymerizable composition, flame-retardant adhesive sheet and flame-retardant adhesive tape using the same - Google Patents

Abstract

(57) Abstract: A photopolymerizable composition having excellent shear strength, peeling strength and flame retardancy, and an adhesive tape and an adhesive tape using the same are provided. (A) An alkyl group having 1 to 12 carbon atoms
(Meth) acrylic acid ester monomer (a) 50 to 98
% By weight, 50 to 2% by weight of a monomer (b) having a polar group and copolymerizable with the monomer (a), and copolymerizable with these monomers (a) and (b) and in the molecule. Monomer (c) 0.01 having two or more unsaturated double bonds
0.01 to 5 parts by weight of (B) the photopolymerization initiator, and (c) to 100 parts by weight of the monomer mixture having 1 to 1% by weight.
A composition comprising 5 to 70 parts by weight of a flame retardant such as ammonium polyphosphate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a flame-retardant photopolymerizable composition, a flame-retardant adhesive sheet and a flame-retardant adhesive tape using the same.

[0002]

2. Description of the Related Art Conventionally, various foams such as polyethylene foams, chloroprene foams, urethane foams and acrylic foams have been used as a tape base material, and acrylic adhesive layers have been provided on both sides of the tape base material. Unlike double-sided adhesive coating, so-called double-sided adhesive foam tape has excellent work efficiency because it does not volatilize solvent during bonding work and develops adhesive strength quickly. In many industrial fields such as materials, it is widely used for joining work as an alternative to adhesives.

However, in the double-sided pressure-sensitive adhesive foam tape, since the foam itself which is the base material has a low mechanical strength, the adhesive strength evaluated by quality characteristics such as shear strength and peel strength is the foam base. Since it is determined by the cohesive failure strength of the material,
There is a problem that higher breaking strength, that is, higher adhesive strength cannot be obtained.

In recent years, it is not uncommon for the above-mentioned industrial fields to be strongly required to have flame retardancy, but a double-sided pressure-sensitive adhesive tape provided with photo-polymerization and having flame retardancy has not been found so far. As a method of imparting flame retardancy, a method of adding a halogen-containing compound is generally adopted. Although flame retardancy can be imparted by this method, smoke may be generated at the time of processing or combustion, and it is necessary to take measures against smoke separately, so flame retardancy due to non-halogen compounds that do not use halogen-containing compounds Grant is strongly desired.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, has excellent shear strength and peel strength, and is also flame retardant photopolymerizable composition excellent in flame retardancy. An object of the present invention is to provide a flame-retardant adhesive sheet and a flame-retardant adhesive tape using the same.

[0006]

The flame-retardant photopolymerizable composition according to the invention of claim 1 has an alkyl group having 1 to 1 carbon atoms.
2 (meth) acrylic acid ester monomer (a) 50-
A monomer (b) having a polar group of 98% by weight and copolymerizable with the (meth) acrylic acid ester monomer (a).
50 to 1% by weight and 0.01 to 1% by weight of a monomer (c) copolymerizable with the monomers (a) and / or (b) and having two or more unsaturated double bonds in the molecule. 100 parts by weight of a monomer mixture (A) containing 0.01 to 5 parts by weight of a photopolymerization initiator and ammonium polyphosphate of 5 to 70 parts by weight.
"Parts by weight".

The flame-retardant photopolymerizable composition according to the inventions of claims 2 to 5 has the following characteristics: "in the invention of claim 1, 5 to 70 parts by weight of ammonium polyphosphate is replaced with ammonium polyphosphate 5 to 5 parts by weight. 70 parts by weight and 2 to 30 parts by weight of red phosphorus, ammonium polyphosphate, a mixture of a nitrogen-containing compound represented by the following general formula and a metal oxide (B) 5 to 7
Containing 0 parts by weight, containing 5 to 50 parts by weight of a phosphorus compound and 2 to 15 parts by weight of thermally expansive graphite, 5 to 50 parts by weight of a halogen-based flame retardant, or 5 to 50 of the halogen-based flame retardant. Any one of a total of 2 parts by weight and 2 to 25 parts by weight of antimony trioxide is employed. "

[0008]

Embedded image

In the general formula (I), R ¹ , R ² , R ³
Represents a hydrogen atom, a hydroxylalkyl group having 1 to 16 carbon atoms, a dihydroxylalkyl group, or a hydroxylaryl group or a dihydroxylaryl group having 6 to 16 carbon atoms.

The flame-retardant adhesive sheet according to the invention of claim 6 is characterized in that "the release sheet is covered with claim 1, 2, 3, 4 or 5
It is formed by applying the flame-retardant photopolymerizable composition described above and irradiating the flame-retardant photopolymerizable composition with light.

A flame-retardant pressure-sensitive adhesive tape according to a seventh aspect of the invention is characterized in that "a pressure-sensitive adhesive layer is formed on at least one surface of the flame-retardant adhesive sheet according to the sixth aspect". .

The monomer mixture (A) used as the main component of the flame-retardant photopolymerizable composition of the present invention contains a (meth) acrylic acid ester monomer (a) having an alkyl group having 1 to 12 carbon atoms. A monomer (b) having a polar group and copolymerizable with the monomer (a), a monomer (a) and / or
Alternatively, it contains a monomer (c) copolymerizable with (b) and having two or more unsaturated double bonds in the molecule.

The (meth) acrylic acid ester monomer (a) is a (meth) acrylic acid ester having an alkyl group having 1 to 12 carbon atoms, preferably 4 to 1 carbon atoms.
Those having 2 alkyl groups can be mentioned. Specific examples thereof include n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, isobornyl. Examples thereof include (meth) acrylate, and these may be used alone or in combination of two or more kinds.

Considering the balance between the tackiness and the cohesiveness of the flame-retardant photopolymerizable composition, a (meth) acrylic acid ester having a homopolymer glass transition temperature (Tg) of -50 ° C. or lower is usually used. It is preferable to use a main component in combination with a (meth) acrylic acid ester having a lower alkyl group such as methyl (meth) acrylate or ethyl (meth) acrylate.

The above (meth) acrylic acid ester monomer (a) is contained in the monomer mixture (A) in an amount of 50 to 98% by weight.
The content is preferably in the range of 70 to 90% by weight. When the content of the monomer (a) is less than 50% by weight, the cohesive force of the resulting monomer mixture (A) becomes too high, and the adhesive sheet obtained by using the flame-retardant photopolymerizable composition Alternatively, the cohesive force of the adhesive tape becomes high and the adhesive force becomes insufficient. On the other hand, when it exceeds 98% by weight, the cohesive force of the obtained monomer mixture (A) becomes weak, the cohesive force of the adhesive sheet or the adhesive tape obtained becomes weak, and the shear strength becomes insufficient.

Next, as the monomer (b), a monomer having a polar group and copolymerizable with the (meth) acrylic acid ester monomer (a) is used. Examples of such a monomer (b) include carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, fumaric acid and itaconic acid, or anhydrides thereof; (meth) acrylonitrile,
Nitrogen-containing monomers such as N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine, (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropylacrylamide; 2-hydroxyethyl (meth) Hydroxyl group-containing monomers such as acrylate, 2-hydroxypropyl methacrylate and 2-hydroxybutyl acrylate are preferably used.

The monomer (b) is contained in the monomer mixture (A) in an amount of 1 to 50% by weight, preferably 10 to 30% by weight. When the content of the monomer (b) is less than 1% by weight, the adhesive force of the adhesive sheet or the pressure-sensitive adhesive tape obtained by using the flame-retardant photopolymerizable composition becomes insufficient and exceeds 50% by weight. In this case, the resulting adhesive sheet or pressure-sensitive adhesive tape has insufficient shear strength.

Next, as the monomer (c), those which are copolymerizable with the above-mentioned monomers (a) and (b) and have two or more unsaturated double bonds in the molecule are used.
Examples of such a monomer (c) include hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, penta. Erythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate
In addition to acrylate, trimethylolpropane trimethacrylate, allyl (meth) acrylate, vinyl (meth) acrylate and divinylbenzene, bifunctional epoxy acrylate, polyester acrylate, urethane acrylate and the like are preferably used.

The above-mentioned monomer (c) is contained in the monomer mixture (A) in an amount of 0.01 to 1% by weight.
When a low molecular weight monomer such as hexanediol diacrylate or divinylbenzene is used, it is preferably contained in the monomer mixture (A) in the range of 0.02 to 0.08% by weight. When a high molecular weight monomer such as diacrylate or urethane acrylate is used, it is preferably contained in the monomer mixture (A) in an amount of 0.2 to 0.8% by weight.

Monomer (c) in monomer mixture (A)
When the content is less than 0.01% by weight, the adhesive sheet or adhesive tape obtained has insufficient cohesive force and insufficient creep resistance. When it exceeds 1% by weight, the cohesive force is insufficient. Becomes too high, and the peel strength decreases.

Examples of the photopolymerization initiator used in the flame-retardant photopolymerizable composition of the present invention include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl).
Ketones such as ketone [Ciba Geigy, Darocure 2959]; α-hydroxy-α, α′-dimethyl-acetophenone [Ciba Geigy, Darocure 117
3], methoxyacetophenone, 2,2-dimethoxy-
2-Phenylacetophenone [Ciba Geigy, Irgacure 651], 2-Hydroxy-2-cyclohexylacetophenone [Ciba Geigy, Irgacure 1]
84] and the like; ketals such as benzyl dimethyl ketal; and other halogenated ketones, acylphosphinoxides, acylphosphonates and the like.

The above photopolymerization initiator is used in an amount of 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight, based on 100 parts by weight of the monomer mixture (A). When the content of the photopolymerization initiator is less than 0.01 part by weight, the polymerization reaction is difficult to proceed, and thus a sufficient conversion cannot be obtained, and when it exceeds 5 parts by weight, the radical generation amount is The degree of polymerization of the copolymer does not increase as the amount increases.

The above-mentioned monomer mixture (A) and the photopolymerization initiator are common to the inventions described in claims 1 to 5, and the flame retardant described below is described in claims 1 to 5.
In the invention described in 5, the different components are used, and the invention relating to each flame-retardant photopolymerizable composition is characterized.

In the inventions of claims 1 to 3, the ammonium polyphosphate used as a flame retardant or as a component in the flame retardant preferably has a degree of polymerization of 200 to 1000, and further has a surface of melamine / It is preferable to use a free-flowing powdery form coated with a formaldehyde resin and sparingly soluble in water.

The ammonium polyphosphate in the inventions of claims 1 and 2 is used in the range of 5 to 70 parts by weight, preferably 10 to 40 parts by weight, based on 100 parts by weight of the monomer mixture (A). , And more preferably 15 to 30 parts by weight. When the content of ammonium polyphosphate is less than 5 parts by weight, sufficient flame retardancy cannot be obtained, and when it exceeds 70 parts by weight, the light transmittance of the obtained flame retardant photopolymerizable composition. Becomes smaller and the rate of the polymerization reaction is significantly reduced.

In the invention of claim 2, as red phosphorus, which is a component other than ammonium polyphosphate used as a flame retardant, commercially available red phosphorus can be adopted, but moisture resistance and handling safety ( It is preferable that the surface of the red phosphorus particles is coated with a resin in view of (self-ignition due to impact). Red phosphorus is used in the range of 2 to 30 parts by weight with respect to 100 parts by weight of the monomer mixture (A). When the content of red phosphorus is less than 2 parts by weight, sufficient flame retardancy cannot be obtained, and when it exceeds 30 parts by weight, the light transmittance of the obtained flame retardant photopolymerizable composition is low. It becomes small and the rate of the polymerization reaction is remarkably reduced.

In the invention according to claim 3, as the flame retardant, in addition to the above-mentioned ammonium polyphosphate, 3 of a nitrogen-containing compound represented by the above-mentioned general formula (I) and a metal oxide is used.
A mixture of component systems (B) is used.

Examples of the nitrogen-containing compound represented by the general formula (I) include isocyanuric acid, mono (hydroxymethyl) isocyanurate and bis (hydroxymethyl).
Isocyanurate, tris (hydroxymethyl) isocyanurate, mono (dihydroxymethyl) isocyanurate, bis (dihydroxymethyl) isocyanurate,
Tris (dihydroxymethyl) isocyanurate, mono (2-hydroxyethyl) isocyanurate, bis (2
-Hydroxyethyl) isocyanurate, tris (2-
Hydroxyethyl) isocyanurate, tris (1,2)
-Dihydroxyethyl) isocyanurate, tris (3
-Hydroxypropyl) isocyanurate, tris (2,3-dihydroxypropyl) isocyanurate,
Tris (4-hydroxybutyl) isocyanurate, Tris (3,4-dihydroxybutyl) isocyanurate, Tris (8-hydroxyoctyl) isocyanurate, Tris (4-hydroxyphenyl) isocyanurate, Tris (2,4-dihydroxyphenyl) ) Isocyanurate, tris (2,3-dihydroxyphenyl) isocyanurate and the like can be mentioned, and these may be used alone or in combination of two or more kinds. Among these, tris (2-hydroxyethyl) isocyanurate, which is particularly excellent in flame retardancy, is recommended.

Examples of the above metal oxides include magnesium oxide, aluminum oxide, titanium oxide, cobalt oxide, vanadium oxide, chromium oxide, manganese oxide, iron oxide, nickel oxide, zinc oxide, etc. Any which produces multiple oxides may be used. Of these, titanium dioxide is particularly preferable.

In the invention of claim 3, the composition ratio of the three-component system in the mixture (B) is such that ammonium polyphosphate: nitrogen-containing compound: metal oxide = 40 to 94.
It is preferably used in the range of 9% by weight: 5 to 40% by weight: 0.1 to 20% by weight. This three-component flame retardant is one in which the carbonized layer expands upon heating and exhibits flame retardancy. If the composition ratio deviates from this range, the volume expansion of the residue after heating will be small and sufficient flame retardancy will be achieved. The sex is not demonstrated.

In the third aspect of the invention, the mixture (B) comprising the three-component flame retardant is the monomer mixture (A).
It is used in the range of 5 to 70 parts by weight, preferably 10 to 50 parts by weight, and more preferably 2 to 100 parts by weight.
0 to 40 parts by weight. The content of the mixture (B) is
If the amount is less than 5 parts by weight, sufficient flame retardancy cannot be obtained and 70
When the amount is more than parts by weight, the light transmittance of the obtained flame-retardant photopolymerizable composition becomes small and the rate of the polymerization reaction remarkably decreases.

In the invention according to claim 4, as the flame retardant, a phosphorus compound and heat-expandable graphite are used in combination.

Examples of the phosphorus compounds include phosphoric acid esters such as triphenyl phosphate, octyl diphenyl phosphate, trioctyl phosphate, tricresyl phosphate; metal phosphate salts such as sodium phosphate, potassium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate and the like. Or hydrates of these metal phosphates; salts of phosphoric acid with ammonia or amines such as ammonium phosphate, ammonium polyphosphate, phosphates of ethylenediamine, phosphates of diethylenetriamine, and their condensates; phosphates of guanidine. , Phosphines, phosphine oxides, t-butylphosphones, phenylphosphones, melamine-modified ammonium polyphosphate, red phosphorus and the like, and these may be used alone or in combination of two or more. .

Of the above phosphorus compounds, ammonium polyphosphate is particularly preferable because it is easy to handle and excellent flame retardancy can be obtained. Incidentally, as ammonium polyphosphate,
It is preferable that the polymerization degree is 200 to 1000, and that it is preferable to use a free-flowing powdery substance whose surface is coated with a melamine / formaldehyde resin and which is hardly soluble in water. This is the same as the case of the ammonium polyphosphate in the inventions described in Items 1 to 3.

As the above-mentioned thermally expandable graphite, conventionally known ones can be adopted. For example, powdery ones such as natural flaky graphite, pyrolytic graphite, quiche graphite and the like are concentrated sulfuric acid, nitric acid and selenic acid. An inorganic acid such as
It is a layered structure of carbon that is produced by treating with a strong oxidizing agent such as concentrated nitric acid, perchloric acid, perchlorate, permanganate, dichromate, hydrogen peroxide, etc. to form a graphite intercalation compound. It is a crystalline compound while maintaining.

Further, it is preferable that the heat-expandable graphite obtained by the above acid treatment is further neutralized with ammonia, an aliphatic lower amine, an alkali metal compound, an alkaline earth metal compound or the like before use. Examples of the aliphatic lower amines include monomethylamine, dimethylamine, trimethylamine, ethylamine, propylamine and butylamine, and examples of the alkali metal compound and alkaline earth metal compound include potassium, sodium, calcium and barium. Hydroxides of metals such as magnesium
Examples thereof include oxides, carbonates and organic acid salts.

When the volume expansion coefficient of the above-mentioned heat-expandable graphite when expanded is small, sufficient flame retardancy cannot be obtained. Therefore, when the heat-expansion graphite is rapidly heated to 800 ° C. or higher, the volume expansion coefficient is It is preferable to use 100 times or more. Whether or not the graphite has such a volume expansion coefficient can be confirmed, for example, by performing a test according to the following procedure.

That is, 1 ml of the heat-expandable graphite was put into a platinum crucible having an inner volume of 100 ml and placed in an electric furnace preheated to 800 ° C. or higher. After input, 3
After 0 seconds, remove the crucible and let it cool to room temperature. It can be easily confirmed by whether or not the amount of the heat-expandable graphite expanded by heating exceeds the amount that completely fills the volume in the crucible.

If the particle size of the heat-expandable graphite becomes smaller, the degree of thermal expansion becomes smaller and sufficient flame retardancy cannot be obtained, and if it becomes larger, the dispersibility becomes poor and the physical properties of the obtained sheet or tape deteriorate. It is preferable to use one having a size of ˜200 mesh.

In the invention of claim 4, the weight ratio of the phosphorus compound and the thermally expandable graphite is 1: 9 to 9: 1.
It is preferable to use it in the range. This is because if the blending ratio deviates from this range, there is not much difference in flame retardancy from the case where the phosphorus compound and the thermally expandable graphite are used alone.

In the invention according to claim 4, the content of the phosphorus compound, which is one component of the flame retardant, with respect to 100 parts by weight of the monomer mixture (A) is used in the range of 5 to 50 parts by weight, preferably. 10 to 40 parts by weight, more preferably 1
5 to 30 parts by weight. When the content of the phosphorus compound is less than 5 parts by weight, sufficient flame retardancy cannot be obtained, and when it exceeds 50 parts by weight, the light transmittance of the obtained flame retardant photopolymerizable composition is low. It becomes small and the rate of the polymerization reaction is remarkably reduced.

The content of the heat-expandable graphite which is another component of the flame retardant in 100 parts by weight of the monomer mixture (A) is 2 to 15 parts by weight, preferably 3 to 12 parts by weight. Parts by weight, more preferably 5 to 10 parts by weight. When the content of the heat-expandable graphite is less than 2 parts by weight, sufficient flame retardancy cannot be obtained, and when it exceeds 15 parts by weight, the light transmission of the obtained flame-retardant photopolymerizable composition is obtained. The rate becomes small and the rate of the polymerization reaction remarkably decreases.

In the invention according to claim 5, as the flame retardant, a halogen-based flame retardant, or the halogen-based flame retardant and antimony trioxide are used in combination.

Examples of the halogen-based flame retardant include halogenated aromatic compounds, halogenated aliphatic compounds, halogenated aromatic compounds,
Examples thereof include halogenated alicyclic compounds. From the viewpoint of flame retardancy, it is preferable to select and use a compound having a bromine content of 40% or more. Examples of such halogen-based flame retardants include decabromodiphenyl oxide, hexabromobenzene, tris (2,3-dibromopropyl) isocyanurate, and 2,2-bis (4-hydroxy-3,5).
Dibromophenyl) propane and the like.

In the invention of claim 5, when a halogen-based flame retardant is used as the flame retardant or as one component of the flame retardant, the content is 5 to 50 per 100 parts by weight of the monomer mixture (A). It is used in the range of 10 parts by weight, preferably 10 to 40 parts by weight, more preferably 15 to 30 parts by weight.
Parts by weight. When the content of the halogen-based flame retardant is less than 5 parts by weight, sufficient flame retardancy cannot be obtained, and when it exceeds 50 parts by weight, the light transmission of the obtained flame retardant photopolymerizable composition is obtained. The rate becomes small and the rate of the polymerization reaction remarkably decreases.

In the invention according to claim 5, when the halogen-based flame retardant and antimony trioxide are used in combination, the content of antimony trioxide with respect to 100 parts by weight of the monomer mixture (A) is 2 to 25 parts by weight. Used in part range. When the content is less than 2 parts by weight, sufficient flame retardancy cannot be obtained, and when the content exceeds 25 parts by weight, the light transmittance of the obtained flame-retardant photopolymerizable composition becomes small, and the polymerization becomes difficult. The reaction rate is significantly reduced.

In order to improve heat resistance, the flame-retardant photopolymerizable composition of each of the above-mentioned inventions has a Tg of 0 ° C. or higher, such as vinyl acetate or vinyl propionate.
You may mix | blend the monomer which has.

Further, a tackifying resin may be blended. Specific examples include rosin resins, modified rosin resins, terpene resins, terpene phenol resins, C
5 and C9 petroleum resins, chroman resins, hydrogenated products of these resins, and the like. These may be used alone or in combination of two or more kinds. However, when a monomer having a Tg of 0 ° C. or higher or a tackifying resin is compounded in a composition and polymerized, the polymerization rate may decrease or the molecular weight may decrease. ,
It is preferable to appropriately adjust the blending amount of the monomer (c) in the monomer mixture (A).

The chain transfer agent is used for adjusting the molecular weight of the copolymer obtained by photopolymerizing the composition.
For example, a mercapto compound is preferable, and specific examples thereof include n-dodecyl mercaptan (also referred to as dodecanethiol) and t-dodecyl mercaptan. These chain transfer agents can be used in the range of 0.01 to 0.1 parts by weight with respect to 100 parts by weight of the monomer mixture (A).

In order to prepare the flame-retardant photopolymerizable composition of the invention described in claims 1 to 5, the above-mentioned monomer mixture (A),
The photopolymerization initiator, flame retardant and other additives may be mixed with uniform stirring according to a conventional method.

Next, the flame-retardant adhesive sheet according to the invention of claim 6 will be described. This sheet does not necessarily require a so-called tape substrate. The invention according to any one of claims 1 to 5 above, simply on a release sheet provided with releasability, that is, a sheet made of a synthetic resin such as paper, cloth, or polyethylene terephthalate (PET) whose surface is release-treated. It is obtained by applying the flame-retardant photopolymerizable composition (1) and photopolymerizing the coating film as described later. The release sheet is usually left as it is as a part of the product and is peeled off from the adhesive sheet at the time of use.

To produce this flame-retardant adhesive sheet,
First, in order to make the surface of the desired flame-retardant adhesive sheet smooth, the flame retardant (C) is particularly contained in the components constituting the composition.
The prepared composition is further sufficiently stirred and thickened to impart thixotropy property so that it is uniformly dispersed in the monomer mixture (A) and the photopolymerization initiator (B). Next, this composition may be coated on a release sheet to have a predetermined thickness, and then the coated surface may be irradiated with light. A known technique is used as a coating means.

The flame-retardant adhesive sheet can thus be formed to have a thickness in the range of 50 μm to 5 mm. When a tape having a thickness of 100 μm or less is produced, it can be obtained by applying a composition having a viscosity of about 1000 cps and a thixotropic index (TI) value of about 1.5 showing thixotropic property. When producing a tape having a thickness of more than 100 μm, it is preferable that the composition has a higher viscosity.

A means for increasing the viscosity of the flame-retardant photopolymerizable composition is a thermoplastic elastomer such as acrylic rubber, nitrile rubber, diblock rubber such as styrene-isoprene-styrene block (SIS), or triblock rubber. , Thermoplastic resin such as polymethylmethacrylate (PMMA), polystyrene (PSt), etc. may be dissolved, or silica particles having an average particle diameter of 5 μm or less, alumina particles, etc. may be mixed with the composition.

When an inorganic substance is added among the above-mentioned additives, it is preferable to use particles whose surface is subjected to a hydrophobizing treatment from the viewpoint that primary particles can be dispersed more quickly. Further, as another method for increasing the viscosity, there is a method of previously partially polymerizing a part of the composition without adding the above-mentioned additives, as will be described later.

This partial polymerization must be carried out before adding the monomer (c) to prevent microgel formation. If microgel is partially formed, it is likely to cause streaks and the like during coating, so caution is required. The amount of monomers to be partially polymerized must be in the range of 1.5 to 60% by weight of the total monomer mixture, that is, the monomer mixture (A). If the amount of the partially polymerized monomer is less than 1.5% by weight, the required viscosity cannot be obtained, and if the amount is more than 60% by weight, the viscosity of the obtained composition becomes too high and the composition is applied. Can be difficult.

To irradiate the flame-retardant photopolymerizable composition coated on the release sheet as described above with light, the following procedure is carried out.

For light irradiation, lamps having a light emission distribution at a light wavelength of 400 nm or less are used. Such lamps include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, chemical lamps, black light lamps,
Examples include microwave-excited mercury lamps and metal halide lamps. Among these, the chemical lamp efficiently emits light in the active wavelength region of the photopolymerization initiator, and components other than the photopolymerization initiator in the composition do not absorb light in this wavelength region so much. Light can be transmitted to the inside, and a thick film sheet can be manufactured.

The light irradiation intensity of the above-mentioned lamps is a factor that influences the degree of polymerization of the obtained polymer, and is appropriately controlled depending on the performance of the target product. For example, when a cleavage type photopolymerization initiator having a commonly used acetophenone group is used, light in a wavelength region effective for its photodecomposition (a wavelength region of 365 to 420 nm, which varies depending on the photopolymerization initiator) is used. The light irradiation intensity is 0.1 to 100 mW /
It is preferably in the range of cm ² .

In the photopolymerization according to the sixth aspect of the invention, the reaction is inhibited by oxygen in the air and oxygen dissolved in the composition. For this reason, it is preferable that the light irradiation is carried out by using a method that is not affected by oxygen. As such a method, for example, the coated flame-retardant photopolymerizable composition is covered with a transparent film such as PET or polytetrafluoroethylene whose surface has been subjected to a release treatment, and light is applied to the composition through the transparent film. There is a method of irradiation.

As another method, there is a method of irradiating light from the outside through an optically transparent window in an inert zone in which oxygen is replaced by an inert gas such as nitrogen gas or carbon dioxide gas to cause a reaction. . In the method of reacting in an inert zone, the oxygen concentration in the irradiation atmosphere is 5000 ppm or less in order to sufficiently complete the photopolymerization until the conversion of the composition becomes 99.7% or more. It is preferably, and more preferably 300 ppm or less.

When the photopolymerization reaction proceeds rapidly, the release sheet to be coated or the cover release sheet may be expanded or contracted by heat due to the polymerization heat, and streaks or the like may occur on the obtained sheet or tape. . The generation of such streaks suppresses the radiant heat from the lamp by the light cut filter,
This can be prevented by bringing the back surface on the opposite side of the irradiation surface into contact with a cooling plate to cool it.

The flame-retardant adhesive sheet according to the sixth aspect of the invention is obtained by curing the flame-retardant photopolymerizable composition coated on the release sheet by photopolymerization. When the glass transition temperature (Tg) of the flame-retardant adhesive sheet crosslinked by this photopolymerization is 50 ° C. or less, the adhesive sheet made of this crosslinked body is slightly heated by a dryer or the like during the joining operation. A heat-sensitive (= hot melt type) flame-retardant adhesive sheet that exhibits adhesive strength by itself.

When the Tg of the flame-retardant adhesive sheet is 20 ° C. or less, a sheet having tackiness at room temperature can be obtained. When importance is attached to the field workability in winter when the atmospheric temperature is 0 ° C. or lower, it is preferable to set Tg to 5 ° C. or lower. The improvement of the adhesive strength of the flame-retardant adhesive sheet can be achieved by adjusting the composition of the flame retardant, regardless of the Tg of the adhesive layer obtained by polymerization.

Next, the flame-retardant pressure-sensitive adhesive tape of the invention of claim 7 will be described. This tape is obtained by forming a pressure-sensitive adhesive layer on at least one surface of the flame-retardant adhesive sheet according to the sixth aspect of the present invention. That is, in this case, the flame-retardant adhesive sheet itself serves as the base material of the tape. As the pressure-sensitive adhesive forming the newly laminated pressure-sensitive adhesive layer, acrylic, rubber-based, silicone-based pressure-sensitive adhesives can be used, and those pressure-sensitive adhesives are solvent-based, water-dispersed, hot-melt. Any type of mold may be used.

When the pressure-sensitive adhesive used is a hot-melt type or a photopolymerization type, it can be directly applied and laminated on the flame-retardant adhesive tape as a base material. When the pressure-sensitive adhesive used is a solvent type or a water-dispersed type, the pressure-sensitive adhesive is coated on a release sheet and dried to form a pressure-sensitive adhesive layer, and then the above-mentioned flame-retardant which becomes a base material. On the adhesive sheet,
A method of transferring and laminating the pressure-sensitive adhesive layer is used.

When a solvent-type or water-dispersion type pressure-sensitive adhesive is applied directly regardless of the transfer method, the solvent or water diffuses into the flame-retardant adhesive sheet, and it takes a long time to dry it. It may cost. When the adhesive used is a photopolymerization type,
Of course, it is necessary to irradiate the surface again with light after coating.

The composition and composition of the above-mentioned pressure-sensitive adhesive are preferably changed according to the adherend. For example, when the adherend is a polyolefin such as polyethylene or polypropylene, it is preferable to use an acrylic adhesive or a natural rubber adhesive containing 20 to 35% by weight of a tackifying resin.
When the adherend is a soft vinyl chloride resin, an acrylic adhesive containing N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine, etc. as a polar component and containing no carboxyl group is used. A flame-retardant adhesive tape excellent in heat aging resistance can be obtained.

(Function) The flame-retardant photopolymerizable composition of the present invention,
The flame-retardant adhesive sheet and the flame-retardant pressure-sensitive adhesive tape using the same are characterized in that the composition comprises a monomer mixture (A) consisting of a specific acrylic monomer mixture, a photopolymerization initiator and a specific flame retardant. The obtained adhesive sheet or pressure-sensitive adhesive tape has excellent flexibility and excellent adhesive strength and flame retardancy as indicated by shear strength and peel strength.

Although the reason is not always clear,
It is considered that by blending a specific flame retardant in an acrylic crosslinked product having a specific composition, not only the flame retardancy but also the elastic modulus is increased and the shear strength is improved due to the synergistic effect of the two.

[0071]

Embodiments of the present invention will be described below in detail.

Example 1 In a separable flask equipped with a cooling tube, a thermometer and a stirrer, 900 g of 2-ethylhexyl acrylate, 100 g of acrylic acid, and 2-hydroxy-2-cyclohexylacetophenone (trade name as a photopolymerization initiator) : 0.3 g of Irgacure 184), 200 g of ammonium polyphosphate (made by Hoechst), 50 g of red phosphorus (made by Rin Kagaku Kogyo, trade name: Novalet 120), stirred and mixed until uniformly dispersed, and then nitrogen Dissolved oxygen was removed by purging the gas.

Next, when the composition in the flask was irradiated with ultraviolet rays using a black light lamp, the temperature of the composition increased and the viscosity increased at the same time. Light irradiation was stopped when the temperature of the composition rose by 5 ° C. The composition obtained is hereinafter referred to as "partial photopolymerization thickening composition". The partially photopolymerized thickening composition had a conversion of 4.1% and a viscosity of 2300 cps.

Further, 0.5 g of hexanediol diacrylate was added to this partially photopolymerized thickening composition to obtain a composition of the present invention.

Next, as shown in FIG. 1, this composition was formed on the release-treated surface of a release sheet 1a made of PET having a thickness of 38 μm so that the thickness at the end of the polymerization was 1.0 ± 0.1 mm. Was applied to form a composition layer 2, and the same release sheet 1b was used to cover the composition layer 2 so that its release-treated surface was in contact with the composition layer 2.

Then, using a chemical lamp, the irradiation intensity on the release sheet 1b used for this cover was 2 mW / c.
The flame retardance of the invention according to claim 6, wherein the lamp height is adjusted to m ² and the composition layer 2 is photopolymerized by irradiation for 8 minutes to have an adhesive layer 2a between the release sheets 1a and 1b. The adhesive sheet 10 was obtained. The residual monomer in the adhesive layer 2a of the flame-retardant adhesive sheet 10 was 0.1%, and the gel fraction was 86.
%Met.

Using the flame-retardant adhesive sheet 10 thus obtained, shear strength, T-peel strength and flame retardancy were measured and evaluated, and the results are shown in Table 1. When performing these measurements, the release sheets 1a and 1b used for the cover were removed and only the adhesive layer 2a was used.

The methods for measuring and evaluating the shear strength, T-peel strength and flame retardancy are as follows. Shear strength As shown in FIG. 2, a primer surface-treated width of 25 m was applied to both surfaces of the adhesive layer 2a having a width of 20 mm and a length of 20 mm.
The edges of a polycarbonate plate 3 of m × length 100 mm × thickness 2 mm were stuck together and left at room temperature for 24 hours to give a test piece, and the shear strength was measured using a tensile tester. still,
The pulling speed is 50 mm / min, and the arrow indicates the pulling direction. T Peel Strength As shown in FIG. 3, a primer surface-treated thickness of 30 was applied to both surfaces of the adhesive layer 2a having a width of 20 mm and a length of 70 mm.
The aluminum foil 4 having a thickness of 0 μm was attached and left at room temperature for 24 hours to prepare a test piece, and the T peel strength was measured using a tensile tester. The pulling speed is 200 mm / min, and the arrows indicate the peeling location and the peeling direction. Flame retardance Flame retardancy was evaluated by testing flammability according to JIS D1201.

Example 2 Isononyl acrylate 95
0 g, acrylic acid 10 g, N-vinylpyrrolidone 40
g and ammonium polyphosphate (600 g) were stirred and mixed with a disper at 1000 rpm for 4 hours to obtain a viscous liquid. To this, 0.3 g of a photopolymerization initiator (Irgacure 184) and 0.25 g of vinyl methacrylate were added, stirred and mixed until uniform, and then nitrogen gas was purged to remove dissolved oxygen. Using the composition of the invention according to claim 1 thus obtained, the following Example 1
After obtaining a flame-retardant adhesive sheet in the same manner as above, the same measurement and evaluation as in Example 1 were carried out, and the results are shown in Table 1.

(Example 3) 700 g of 2-ethylhexyl acrylate, 200 g of isooctyl acrylate, 100 g of acrylic acid, 60 g of ammonium polyphosphate, and 50 g of red phosphorus were stirred and mixed with a disper for 30 minutes at 1000 rpm to obtain a viscous liquid. It was To this, 0.3 g of allyl acrylate and a photopolymerization initiator (Irgacure 651)
0.3 g was added, and the mixture was stirred and mixed until it became uniform, and then nitrogen gas was purged to remove dissolved oxygen. After obtaining a flame-retardant adhesive sheet in the same manner as in Example 1 below, using the obtained composition of the invention of claim 1,
The same measurements and evaluations as in Example 1 were performed, and the results are shown in Table 1.
It was shown to.

Example 4 In a separable flask equipped with a condenser, a thermometer and a stirrer, 200 g of 2-ethylhexyl acrylate, 700 g of n-butyl acrylate,
After charging 100 g of N-vinylpyrrolidone, 2 g of 2-hydroxyethyl methacrylate, 2 g of n-dodecanethiol and 900 g of ethyl acetate, the temperature was raised to reflux under a nitrogen gas atmosphere, and the temperature was maintained for 20 minutes, and then 1 g of benzyl peroxide was added to 100 g of ethyl acetate. The solution dissolved in was dropped and reacted for 4 hours. After that, the solution is further dropped,
The reaction was performed for 3 hours. Next, stir 400 g of toluene.
By mixing, a pressure-sensitive adhesive solution (D) having a viscosity of 12000 cps was obtained. The solids content was 39.5% by weight.

To 100 g of this pressure-sensitive adhesive solution (D), 300 g of ammonium polyphosphate, 80 g of red phosphorus and 4 g of an isocyanate type curing agent (manufactured by Nippon Polyurethane Co., trade name Coronate L55E) were added and thoroughly mixed, followed by defoaming. As shown in FIG. 4, the release sheet 1c made of release-treated PET was applied to form a pressure-sensitive adhesive layer 5a having a thickness of 40 μm. Then, immediately, the release sheet 1a of the flame-retardant adhesive sheet 10 obtained in Example 1 was removed, and transferred to one adhesive surface by a hot laminating method so that the obtained adhesive layer 5a contacted. A pressure-sensitive adhesive layer is formed, and
A flame-retardant adhesive tape 20 of the described invention was obtained.

As shown in FIG. 5, a soft vinyl chloride resin plate 6 (Shore D hardness = 50, width 25 mm × length 100 mm)
20 mm in width obtained in Example 4 at the edge of (thickness 5 mm)
The release sheets 1a and 1b of the flame-retardant adhesive tape 20 having a length of m × 20 mm are removed, the surface of the adhesive layer 5a is attached, and the surface of the other adhesive layer 2a is attached to the edge of the polycarbonate plate 3. Together, they were heat aged at 80 ° C. for 1 week. A test piece was thus obtained, and the shear strength was measured using this test piece. The pulling speed is 50 mm / min, and the arrow indicates the pulling direction.

With respect to the flame-retardant pressure-sensitive adhesive tape obtained in Example 4, the shear strength and the flame retardancy similar to those in Example 1 were measured and evaluated, and the results are shown in Table 1.

Comparative Example 1 A photopolymerizable composition was obtained in the same manner as in Example 1 except that the flame retardant (C) was not added at all. The conversion rate of the composition thus obtained was 5.
1% and the viscosity was 4100 cps. A flame-retardant adhesive sheet was obtained in the same manner as in Example 1 using the obtained composition. With respect to this flame-retardant pressure-sensitive adhesive sheet, shear strength, T-peel strength and flame retardancy were measured or evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 2 100 g of the adhesive solution (D) obtained in Example 4 was added with 300 g of ammonium polyphosphate,
When 50 g of red phosphorus and 4 g of an isocyanate-based curing agent (manufactured by Nippon Polyurethane Co., Ltd., trade name Coronate L55E) were added, the flame retardant (C) caused coagulation and precipitation, and thus a flame retardant adhesive sheet could not be obtained. Therefore, the shear strength and flame retardancy could not be measured or evaluated.

Comparative Example 3 The flame-retardant adhesive sheet 10 obtained in Comparative Example 1 was used instead of the flame-retardant adhesive sheet 10 obtained in Example 1, and the pressure-sensitive adhesive layer 5a was not laminated. Except for the above, the shear strength and flame retardancy were measured or evaluated in the same manner as in Example 4. That is, as shown in FIG.
The edge of the soft vinyl chloride resin plate 6 was attached to one of the adhesive surfaces of the adhesive sheet 2b obtained in 1., and the edge of the polycarbonate plate 3 was attached to the other adhesive surface to obtain a test piece. The arrow indicates the pulling direction.

(Comparative Example 4) As in Example 4 except that the flame-retardant adhesive sheet obtained in Comparative Example 1 was used in place of the flame-retardant adhesive sheet 10 obtained in Example 1. Similarly, the adhesive tape 2b was obtained, and the shear strength and flame retardancy were measured or evaluated. That is, as shown in FIG. 7, a soft vinyl chloride resin plate 6 is formed on the laminate of the pressure-sensitive adhesive layer 5a and the adhesive sheet 2b.
And each edge of the polycarbonate plate 3 was stuck together to make a test piece. The arrow indicates the pulling direction.

[0089]

[Table 1]

Example 5 As a flame retardant (C), 100 g of ammonium polyphosphate, 50 g of tris (2-hydroxyethyl) isocyanurate (manufactured by Wako Pure Chemical Industries, Ltd.) which is a nitrogen-containing compound, and titanium dioxide (rutile type, Ishihara Sangyo Kaisha, Ltd.) was used in the same manner as in Example 1 except that 20 g was used, and the composition of the invention of claim 3 was obtained.
After obtaining the flame-retardant adhesive sheet of the described invention, the shear strength, T peel strength and flame retardancy were measured and evaluated in the same manner as in Example 1, and the results are shown in Table 2.

Example 6 The same procedure as in Example 2 was repeated except that 50 g of ammonium polyphosphate, 30 g of tris (2-hydroxyethyl) isocyanurate and 10 g of titanium dioxide were used as the flame retardant (C). After obtaining the composition of the invention of claim 3 and further obtaining the flame-retardant adhesive sheet of the invention of claim 6, the same shear strength, T peel strength and flame retardancy as in Example 1 are measured or The evaluation was performed, and the results are shown in Table 2.

Example 7 As flame retardant (C), 400 g of ammonium polyphosphate, 200 g of tris (2-hydroxyethyl) isocyanurate, and 50 titanium dioxide.
Same as Example 3 except that g was used. After obtaining the composition of the invention of Claim 3 and further obtaining the flame-retardant adhesive sheet of Claim 6, the same as Example 1. Na, shear strength,
The T-peel strength and flame retardancy were measured and evaluated, and the results are shown in Table 2.

Example 8 100 g of adhesive solution (D)
As a flame retardant (C), ammonium polyphosphate 150
g, tris (2-hydroxyethyl) isocyanurate 50 g, titanium dioxide 5 g and an isocyanate curing agent (manufactured by Nippon Polyurethane Company, trade name Coronate L55E).
A pressure-sensitive adhesive layer having a thickness of 40 μm was formed in the same manner as in Example 4 except that 4 g was added, and immediately thereafter, Example 5 was used.
A pressure-sensitive adhesive layer is laminated on one of the adhesive surfaces of the adhesive tape obtained in 1. in the same manner as in Example 4 to obtain the flame-retardant adhesive tape according to claim 7 as shown in FIG. , Measurement and evaluation of shear strength and flame retardancy similar to Example 4,
The results are shown in Table 2.

Comparative Example 5 100 g of adhesive solution (D)
As a flame retardant (C), ammonium polyphosphate 80
g, 20 g of tris (2-hydroxyethyl) isocyanurate, 5 g of titanium dioxide, and an isocyanate curing agent (manufactured by Nippon Polyurethane Co., trade name Coronate L55E).
When 4 g was added, the flame retardant (C) caused coagulation and precipitation, and thus a flame retardant adhesive sheet could not be obtained. Therefore, the shear strength and flame retardancy could not be measured or evaluated.

[0095]

[Table 2]

(Example 9) Except that 100 g of ammonium polyphosphate and 50 g of thermally expansive graphite (Nippon Kasei Co., Ltd., trade name: CA60S) were used as the flame retardant (C).
After obtaining the composition of the invention of claim 4 and the flame-retardant adhesive sheet of the invention of claim 6 in the same manner as in Example 1, the shear strength, the T-peel strength and the flame-retardant property are obtained. Measurement or evaluation was performed, and the results are shown in Table 3.

Example 10 A composition according to claim 4 was prepared in the same manner as in Example 2 except that 50 g of ammonium polyphosphate and 80 g of thermally expanded graphite were used as the flame retardant (C). After obtaining the flame-retardant pressure-sensitive adhesive tape of the invention according to claim 6, the shear strength, T-peel strength and flame retardancy were measured and evaluated, and the results are shown in Table 3.

(Example 11) As the flame retardant (C), t-
A composition of the invention according to claim 4 was obtained in the same manner as in Example 3 except that 400 g of butylphosphonic acid (manufactured by Aldrich) and 20 g of thermally expanded graphite were used. After obtaining the flame-retardant pressure-sensitive adhesive tape, shear strength, T-peel strength and flame retardancy were measured or evaluated, and the results are shown in Table 3.

(Example 12) 100 g of adhesive solution (D)
70 g of ammonium polyphosphate as a flame retardant (C),
Example 4 except that 30 g of thermally expandable graphite was used
A pressure-sensitive adhesive layer having a thickness of 40 μm was formed in the same manner as described above, and immediately thereafter, the pressure-sensitive adhesive layer was laminated on one adhesive surface of the adhesive sheet obtained in Example 9 in the same manner as in Example 4 and the same figure was used. After obtaining the flame-retardant adhesive tape according to the invention of claim 7 as shown in 4, the shear strength and flame retardancy were measured and evaluated, and the results are shown in Table 3.

(Comparative Example 6) 100 g of adhesive solution (D)
70 g of ammonium polyphosphate as a flame retardant (C),
When 30 g of heat-expandable graphite and 4 g of isocyanate-based curing agent (product name: Coronate L55E, manufactured by Nippon Polyurethane Co., Ltd.) were added, the flame retardant (C) caused cohesive precipitation, and thus a flame retardant adhesive sheet could not be obtained. . Therefore, the shear strength and flame retardancy could not be measured or evaluated.

[0101]

[Table 3]

Example 13 As a flame retardant (C), decabromodiphenyl oxide (manufactured by Asahi Glass Co., Ltd.) 200 was used.
g, antimony trioxide (manufactured by Mikuni Smelting Co., Ltd.) 50 g was used in the same manner as in Example 1 to obtain the composition of the invention of claim 5, and the flame retardancy of the invention of claim 6. After obtaining the adhesive sheet, shear strength, T peel strength and flame retardancy were measured and evaluated, and the results are shown in Table 4.

(Example 14) A composition of the present invention according to claim 5 was obtained in the same manner as in Example 2 except that 450 g of decabromodiphenyl oxide was used as the flame retardant (C). After obtaining the flame-retardant adhesive sheet of the invention described in 6, the shear strength, T-peel strength and flame retardancy were measured or evaluated, and the results are shown in Table 4.

Example 15 A composition according to claim 5 was prepared in the same manner as in Example 3 except that 70 g of decabromodiphenyl oxide and 50 g of antimony trioxide were used as the flame retardant (C). After obtaining the flame-retardant adhesive sheet of the invention of claim 6, the shear strength, T-peel strength and flame retardancy were measured and evaluated, and the results are shown in Table 4.

(Example 16) Decabromodiphenyl oxide 300 was used as the flame retardant (C) in the adhesive solution (D).
g, an adhesive layer 53 having a thickness of 40 μm was formed in the same manner as in Example 4 except that 80 g of antimony trioxide was used, and immediately thereafter, one adhesive surface of the adhesive tape 32 obtained in Example 13 Then, the pressure-sensitive adhesive layer 53 was laminated in the same manner as in Example 4 to obtain the flame-retardant pressure-sensitive adhesive sheet of the invention according to claim 7 as shown in FIG. 4, and then the shear strength and flame retardancy were measured. The results were shown in Table 4.

(Comparative Example 7) 100 g of adhesive solution (D)
As a flame retardant (C), ammonium polyphosphate 100
g, 50 g of red phosphorus and 4 g of an isocyanate-based curing agent (trade name: Coronate L55E manufactured by Nippon Polyurethane Co., Ltd.) were added, the flame retardant (C) caused coagulation and precipitation.
No flame-retardant adhesive sheet was obtained. Therefore, the shear strength and flame retardancy could not be measured or evaluated.

[0107]

[Table 4]

[0108]

【The invention's effect】

The flame-retardant photopolymerizable composition of the present invention, the flame-retardant adhesive sheet and the flame-retardant flame-retardant pressure-sensitive adhesive tape using the same include a specific acrylic monomer mixture, a photopolymerization initiator and a specific acrylic monomer mixture. A composition containing a flame retardant, and the adhesive sheet or pressure-sensitive adhesive tape obtained by using this composition does not use a tape base material made of a material having poor mechanical strength such as foam, so that shear strength or It is possible to obtain a product having excellent adhesive strength as indicated by peel strength and flame retardancy. Further, by using the flame-retardant adhesive sheet and flame-retardant adhesive tape of the present invention,
It is possible to easily perform the work of joining the above-described structures and the like.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a flame-retardant adhesive sheet obtained by using the flame-retardant photopolymerizable composition of the present invention.

FIG. 2 is a schematic cross-sectional view showing a method for measuring the shear strength of the flame-retardant adhesive sheet of the present invention.

FIG. 3 is a schematic cross-sectional view showing a method for measuring the T peel strength of the flame-retardant adhesive sheet of the present invention.

FIG. 4 is a schematic cross-sectional view showing a flame-retardant pressure-sensitive adhesive tape obtained by using the flame-retardant photopolymerizable composition of the present invention.

FIG. 5 is a schematic cross-sectional view showing a method for measuring the shear strength of another flame-retardant adhesive sheet of the present invention.

FIG. 6 is a schematic cross-sectional view showing a method for measuring the shear strength of the flame-retardant pressure-sensitive adhesive tape of the present invention.

FIG. 7 is a schematic cross-sectional view showing a method for measuring the shear strength of the flame-retardant adhesive tape of the present invention.

[Explanation of symbols]

 1a, 1b Release sheet 2 Composition layer 2a Flame-retardant adhesive sheet 2b Flame-retardant adhesive sheet 3 Polycarbonate plate 4 Aluminum foil 5a Adhesive layer 6 Soft vinyl chloride resin plate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C09J 7/02 JHR C09J 7/02 JHR

Claims (7)

[Claims] 1. A (meth) acrylic acid ester monomer (a) having an alkyl group having 1 to 12 carbon atoms, 50 to 98% by weight, a polar group and a (meth) acrylic acid ester monomer (a). Copolymerizable monomer (b) 50-1
% By weight, and 0.01 to 1% by weight of a monomer (c) copolymerizable with these monomers (a) and / or (b) and having two or more unsaturated double bonds in the molecule. 100 parts by weight of the monomer mixture (A) contained, 0.01 to 5 parts by weight of a photopolymerization initiator, and ammonium polyphosphate 5 to 70
A flame-retardant photopolymerizable composition, characterized in that it comprises 1 part by weight. 2. A monomer mixture (A) 1 according to claim 1.
A flame-retardant photopolymerizable composition, which comprises: 00 parts by weight, 0.01 to 5 parts by weight of a photopolymerization initiator, 5 to 70 parts by weight of ammonium polyphosphate, and 2 to 30 parts by weight of red phosphorus. 3. A monomer mixture (A) 1 according to claim 1.
00 parts by weight, 0.01 to 5 parts by weight of a photopolymerization initiator, and 5 to 70 parts by weight of a mixture (B) of ammonium polyphosphate and a nitrogen-containing compound represented by the following general formula (I) and a metal oxide. A flame-retardant photopolymerizable composition, characterized in that Embedded image (Wherein, R ¹ , R ² , and R ³ are a hydrogen atom, a carbon number of 1 to 1)
6 represents a hydroxylalkyl group, a dihydroxyalkyl group, or a hydroxylaryl or dihydroxyaryl group having 6 to 16 carbon atoms) 4. A monomer mixture (A) 1 according to claim 1.
A flame-retardant photopolymerizable composition, which comprises 00 parts by weight, 0.01 to 5 parts by weight of a photopolymerization initiator, 5 to 50 parts by weight of a phosphorus compound, and 2 to 15 parts by weight of thermally expandable graphite. 5. The monomer mixture (A) 1 according to claim 1.
00 parts by weight, 0.01 to 5 parts by weight of a photopolymerization initiator, 5 to 50 parts by weight of a halogen-based flame retardant or 5 to 50 parts by weight of the halogen-based flame retardant and 2 to 25 parts by weight of antimony trioxide. A flame-retardant photopolymerizable composition. 6. The release sheet according to claim 1, 2, 3, 4,
Alternatively, a flame-retardant adhesive sheet characterized by being formed by applying the flame-retardant photopolymerizable composition according to 5 and irradiating the flame-retardant photopolymerizable composition with light. 7. A flame-retardant pressure-sensitive adhesive tape, comprising a pressure-sensitive adhesive layer formed on at least one surface of the flame-retardant adhesive sheet according to claim 6.