JP2012184849A - Gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gasket not generating toxic halogen based gas when being burned having high flame retardance.SOLUTION: The gasket 10 is mainly comprised of a pressure-sensitive adhesive sheet 10 containing a non-halogenated flame retardant, and at least one surface 10A, 10B thereof is comprised of a main face (a pressure-sensitive adhesive face) of the pressure-sensitive adhesive sheet 1 containing a non-halogenated flame retardant. A base film 2 is laminated on one face of the pressure-sensitive adhesive sheet 10 containing a non-halogenated flame retardant, one face of the gasket 10 is comprised of a surface of the base film 2, and the other one face of the gasket 10 is comprised of an adhesive face of the pressure-sensitive adhesive sheet 1 containing a non-halogenated flame retardant.

Description

  The present invention relates to a flame retardant gasket that does not generate a toxic halogen-based gas during combustion.

  Conventionally, a gasket is interposed between the mating surfaces of the two surfaces in order to prevent liquid and gas movement between the mating surfaces of the two surfaces in various machines, equipment or other structures. Things have been done.

  For example, an antenna for assisting communication between an aircraft and a remote location is provided on the outer surface of the aircraft body wall (outer plate). Many of these antennas have an electrical connector projecting on one side. A flat plate-shaped mounting plate, one side of which the connector of the mounting plate protrudes is overlaid on the outer surface of the aircraft outer plate, and the connector is inserted into the aircraft through the hole drilled in the outer plate of the aircraft. Connected to the appropriate internal electrical circuit. At this time, the antenna mounting plate is usually detachably attached to the aircraft outer plate with bolt parts, and a gasket is interposed between the outer surface of the aircraft outer plate and the inner surface of the antenna mounting plate. Thus, the mounting portion of the antenna is sealed.

  That is, through holes for bolting are formed at corresponding positions of the antenna mounting plate and the aircraft outer plate, and the through holes are formed between the antenna mounting plate and the aircraft outer plate at positions corresponding to these through holes. Inserting a bolt from the outside of the antenna mounting plate into the through hole of the antenna mounting plate, gasket and aircraft outer plate, and attaching a blind nut to the inner surface of the aircraft outer plate The antenna is fixed, but at that time, the gasket is compressed by the deformation of the mounting plate by tightening the bolt, and the gap between the bolt and the bolt hole and the space between the outer plate and the mounting plate of the aircraft are sealed, and moisture enters the aircraft. Is prevented.

  As a gasket used for sealing the antenna mounting portion on the outer plate of such an aircraft, for example, Patent Document 1 proposes a gasket provided with a flexible polyurethane gel layer on both front and back surfaces of a carrier sheet (base film). Has been. According to this publication, a gasket provided with a polyurethane gel layer is not limited to a polyurethane gel having excellent flexibility, elasticity, compressibility, flexibility and the like. It is described that excellent sealing performance is sustained because it is non-reactive with aluminum (including aluminum) and water (including salt water).

  On the other hand, not only the mating surface of the functional article mounting portion on the outer skin of the aircraft as described above, but also inside the aircraft, the two members face each other (that is, the two surfaces). There are many structural parts that are fixed (by forming a mating surface).

  By the way, in general, since high flame resistance is required for aircraft members, high flame resistance is also required for the gasket, and the halogen flame retardant exhibiting high flame resistance is blended in the gasket. However, gaskets containing halogenated flame retardants exhibit high flame retardancy, but a large amount of toxic halogen gas is generated during molding and combustion, causing equipment to corrode and adversely affect the human body and the environment. There is a risk. For this reason, there is a need for a gasket exhibiting high flame retardancy that does not generate toxic halogen-based gases during combustion. Further, most of the adherends to which the gasket is adhered are metal plates, and the gasket is required to have a property that does not discolor or corrode the metal plates.

US Patent Application Publication No. 2004/0070156

The present invention has been made in view of the above circumstances, and the problem to be solved is to provide a highly flame retardant gasket that does not generate a toxic halogen-based gas during combustion. is there.
Another object of the present invention is to provide a highly flame retardant gasket that does not generate a toxic halogen-based gas during combustion and does not cause corrosion or discoloration of a metal member as an adherend.

  As a result of diligent research to solve the above problems, the present inventors have obtained a pressure-sensitive adhesive sheet obtained by blending a non-halogen flame retardant (especially a phosphorus flame retardant) with a polyoxyalkylene-based, acrylic-based, or silicone-based pressure-sensitive adhesive. However, the present inventors have found that it can be a gasket exhibiting sufficiently high flame retardancy, and further research based on such knowledge has led to the completion of the present invention.

  That is, the present invention relates to a gasket characterized in that it mainly comprises a non-halogen flame retardant-containing pressure-sensitive adhesive sheet, and at least one surface is composed of the main surface (adhesive surface) of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet.

  In the gasket of the present invention, the non-halogen flame retardant is preferably a phosphorus flame retardant.

  In the gasket of the present invention, the non-halogen flame retardant-containing pressure-sensitive adhesive sheet preferably contains a tackifier resin, and the tackifier resin is preferably a terpene-based tackifier resin and / or a rosin-based tackifier resin. It is. The rosin tackifier resin is preferably rosin esters, and the terpene tackifier resin is preferably a terpene phenol resin.

In the gasket of the present invention, the non-halogen flame retardant-containing pressure-sensitive adhesive sheet is preferably a polyoxyalkylene-based pressure-sensitive adhesive sheet containing a non-halogen flame retardant, and the polyoxyalkylene-based pressure-sensitive adhesive sheet containing the non-halogen flame retardant is The sheet preferably comprises a cured product of a composition containing the following components A to D.
A: Polyoxyalkylene polymer having at least one alkenyl group in one molecule B: Compound having an average of two or more hydrosilyl groups in one molecule C: Hydrosilylation catalyst D: Non-halogen flame retardant

  Moreover, the gasket of this invention contains the aspect which both surfaces of the gasket used as the contact | adherence surface to a to-be-adhered body consist of the main surface (adhesion surface) of a non-halogen flame retardant containing adhesive sheet.

  In the gasket of the present invention, the base film is laminated on one main surface (adhesive surface) of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet, and one side of the gasket that serves as an adhesion surface to the adherend is the base. In the gasket of this embodiment, including the aspect of the other main surface (adhesive surface) of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet, the other side of the gasket consisting of the surface of the material film and serving as the adhesion surface to the adherend, The base film is preferably a fluororesin film.

  The present invention also provides a sealing method between two mating surfaces, wherein the gasket is interposed between the two mating surfaces.

  According to the present invention, it is possible to realize a flame retardant gasket that has a practically sufficient sealing property and does not generate a toxic halogen-based gas at the time of combustion, and has a practically sufficient sealing property. It is possible to realize a flame retardant gasket that does not generate a toxic halogen-based gas at the time of combustion and does not cause corrosion or discoloration of a metal member as an adherend.

Further, in a preferred embodiment, the high flame retardancy particularly required for aircraft components (that is, the grade “V-0” in the US UL (Underwriters Laboratories) standard “UL-94”).
), A flame retardant gasket that does not generate toxic halogen-based gas during combustion, and that does not cause corrosion or discoloration of the metal part that is the adherend. can do.

FIG. 1 is a schematic cross-sectional view of a typical example of the gasket of the present invention. FIG. 2 is a cross-sectional view schematically showing a state in which the gasket of FIG. 1 is interposed between two adherends and a space between two mating surfaces is sealed. FIG. 3 is a schematic cross-sectional view showing a main part of a modified example of the gasket of the present invention. FIG. 4A is a schematic view of a rolled state of the gasket of the present invention, and FIG. 4B is an enlarged sectional view of a part of the gasket shown in FIG. 5 (A) to 5 (C) are schematic views showing a manufacturing process of the gasket shown in FIG.

Hereinafter, the present invention will be described with reference to preferred embodiments.
FIG. 1 is a schematic cross-sectional view of a gasket 10 according to an example of the present invention, and FIG. 2 is a schematic view of a state in which the gasket 10 is interposed between two adherends and a gap between two mating surfaces is sealed. FIG.

  The gasket of the present invention is mainly composed of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1 as shown in the gasket 10 of this example, and is located between the opposing surfaces of the two adherends 20 and 21 (that is, the alignment of the two surfaces). Between the surfaces) (FIG. 2).

  At least one of the double-sided gaskets 10A and 10B to be adhered to the adherends 20 and 21 (that is, at least one side of the gasket) is formed by the main surface (adhesive surface) 1A of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1. In addition, the main surface (adhesive surface) 1A of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1 is attached to one adherend 20, so that the gasket 10 is displaced between the opposed surfaces of the two adherends 20 and 21. Arranged without waking up.

  In the gasket 10 of the example, the base film 2 is laminated on one main surface 1B of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1, and the surface 2A of the base film 2 is adhered to the adherend 21. However, the gasket of the present invention is composed of only the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1 without laminating the base film 2, and the two main surfaces of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1 are adhered to each other. You may make it stick on a body.

Further, in the gasket 10 of the example, the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1 is a sheet body that does not include a core body, but as shown in FIG. 3, on both front and back surfaces of the core body film 3 as an intermediate layer. A non-halogen flame retardant-containing pressure-sensitive adhesive layer 1a, 1b may be formed in the form of a pressure-sensitive adhesive sheet containing a core.

[Non-halogen flame retardant-containing adhesive sheet]
The non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1 in the present invention is a pressure-sensitive adhesive sheet containing a non-halogen flame retardant, and is composed of a pressure-sensitive adhesive containing a non-halogen flame retardant.

  In general, the thickness of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1 is preferably 300 μm or more, more preferably 800 μm or more from the viewpoint that adhesion to an adherend, sealing performance at the time of bolt penetration, and the like are further improved. is there. Further, from the viewpoint of suppressing the sticking out and preventing deterioration of workability, the thickness is preferably 2000 μm or less, and more preferably 1500 μm or less.

  The pressure-sensitive adhesive used for the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1 is not particularly limited, but is preferably one that can form a pressure-sensitive adhesive sheet excellent in elasticity, compressibility, and adhesion. Examples include oxyalkylene-based pressure-sensitive adhesives. Among them, the polyoxyalkylene-based adhesive is excellent in elasticity, compressibility and adhesion, and can form an adhesive sheet with excellent removability, so by using a polyoxyalkylene-based adhesive, maintenance can be performed. This is preferable because the gasket can be easily detached from the adherend.

(Acrylic adhesive)
As the acrylic pressure-sensitive adhesive, specifically, an acrylic pressure-sensitive adhesive having an acrylic polymer having a main skeleton of an alkyl (meth) acrylate monomer unit as a base polymer is preferable (where “(meth) acrylate” Means "acrylate and / or methacrylate").

  The average carbon number of the alkyl group of the alkyl (meth) acrylate constituting the main skeleton of the acrylic polymer is preferably about 1 to 12, and specific examples of such alkyl (meth) acrylate include methyl (meth) acrylate, ethyl ( Examples include (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, and the like. Used in combination. Of these, alkyl (meth) acrylates having 1 to 9 carbon atoms in the alkyl group are preferred.

In the acrylic polymer, one or more kinds of various monomers are introduced by copolymerization for the purpose of improving the adhesion and heat resistance of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet to the adherend. Specific examples of such copolymerization monomers include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (meth) acrylic acid 6 Hydroxyl group-containing monomers such as hydroxyhexyl, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate and (4-hydroxymethylcyclohexyl) -methyl acrylate Carboxyl group-containing monomers such as (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid and crotonic acid; acid anhydrides such as maleic anhydride and itaconic anhydride Monomer-containing monomer; Caprolac of acrylic acid Adducts such as styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid, etc. And sulfonic acid group-containing monomers such as 2- (phosphonooxy) ethyl acrylate, and the like. Moreover, nitrogen-containing vinyl monomers are mentioned, for example, maleimide, N-cyclohexylmaleimide, N-phenylmaleimide; N-acryloylmorpholine; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N- Diethyl (meth) acrylamide, N-hexyl (meth) acrylamide, N-methyl (meth) acrylamide, N-butyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (N-substituted) amide monomers such as (meth) acrylamide; aminoethyl (meth) acrylate, aminopropyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, (meth) acrylic acid t -Butylaminoethyl, 3- (3 (Meth) acrylic acid alkylaminoalkyl monomers such as (pyridyl) propyl (meth) acrylate; (meth) acrylic acid alkoxyalkyl monomers such as (meth) acrylic acid methoxyethyl and (meth) acrylic acid ethoxyethyl; N- ( Examples thereof include succinimide monomers such as (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyoctamethylene succinimide, and N-acryloylmorpholine.

  Further, vinyl acetate, vinyl propionate, N-vinyl pyrrolidone, methyl vinyl pyrrolidone, vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piperazine, vinyl pyrazine, vinyl pyrrole, vinyl imidazole, vinyl oxazole, vinyl morpholine, N-vinyl carboxylic acid amide , Vinyl monomers such as styrene, α-methylstyrene, N-vinylcaprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; (meth) acrylic Polyethylene glycol acid, polypropylene glycol (meth) acrylate, methoxyethylene glycol (meth) acrylate, methoxypolypropylene (meth) acrylate Glycol acrylic ester monomers such as recall; (meth) acrylic acid tetrahydrofurfuryl, fluorine (meth) acrylate, and silicone (meth) acrylate and acrylic ester monomers such as 2-methoxyethyl acrylate may also be mentioned.

  Among these, when an isocyanate type crosslinking agent is used as a crosslinking agent, a hydroxyl group-containing monomer is preferable because of its good reactivity with an isocyanate group. In addition, a carboxyl group-containing monomer such as (meth) acrylic acid is preferable, and acrylic acid is particularly preferable from the viewpoints of adhesion to the adherend of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet, adhesion durability, weather resistance, and the like. It is.

  The ratio of the copolymerization monomer in the acrylic polymer is preferably about 0.1 to 10% by weight in weight ratio.

  The average molecular weight of the acrylic polymer is not particularly limited, but the weight average molecular weight is generally about 300,000 to 2.5 million.

  The acrylic polymer is produced by various known methods, and for example, a radical polymerization method such as a bulk polymerization method, a solution polymerization method, and a suspension polymerization method can be appropriately selected. As the radical polymerization initiator, various known azo and peroxide initiators can be used. The reaction temperature is usually about 50 to 80 ° C., and the reaction time is 1 to 8 hours.

Acrylic pressure-sensitive adhesives can contain a crosslinking agent in addition to the base polymer, and the crosslinking agent can improve the adhesion and durability with the optical plate. Holding can be achieved. As the crosslinking agent, known crosslinking agents such as isocyanate, epoxy, peroxide, metal chelate, and oxazoline can be appropriately used. These crosslinking agents can be used alone or in combination of two or more. The amount of the crosslinking agent used is 10 parts by weight or less, preferably 0.01 to 5 parts by weight, and more preferably 0.02 to 3 parts by weight with respect to 100 parts by weight of the acrylic polymer. When the proportion of the crosslinking agent used exceeds 10 parts by weight, it is not preferable in that crosslinking may proceed excessively and adhesiveness may be lowered.

(Silicone adhesive)
The silicone pressure-sensitive adhesive is not particularly limited, and is generally used as a peroxide cross-linked silicone pressure-sensitive adhesive (peroxide-curing silicone pressure-sensitive adhesive) or an addition reaction type silicone pressure-sensitive adhesive. Can be suitably used. These peroxide-crosslinked silicone pressure-sensitive adhesives and addition reaction-type silicone pressure-sensitive adhesives can be commercially available. Specific examples of peroxide-crosslinked silicone pressure-sensitive adhesives include KR- manufactured by Shin-Etsu Chemical. 3006A / BT, SH 4280 PSA manufactured by Toray Dow Corning Silicone, and the like. Specific examples of the addition reaction type silicone pressure sensitive adhesive include X-40-3501 manufactured by Shin-Etsu Chemical, BY 24-712 manufactured by Toray Dow Corning Silicone, TSE32X manufactured by GE Toshiba Silicone, and the like. .

(Polyoxyalkylene adhesive)
As a polyoxyalkylene type adhesive, the hardened | cured material of the composition containing the following AC component is preferable.
A: Polyoxyalkylene polymer having at least one alkenyl group in one molecule B: Compound having an average of two or more hydrosilyl groups in one molecule C: Hydrosilylation catalyst

  The “polyoxyalkylene polymer having at least one alkenyl group in one molecule” of the component A is not particularly limited, and various types can be used. Among them, the main chain of the polymer is What has a repeating unit shown by following General formula (1) is suitable.

Formula (1): —R ¹ —O—
(Wherein R ¹ is an alkylene group)

R ¹ is preferably a linear or branched alkylene group having 1 to 14 carbon atoms, more preferably 2 to 4 carbon atoms.

Specific examples of the repeating unit represented by the general formula (1) include —CH ₂ O—, —CH ₂ CH ₂ O—, —CH ₂ CH (CH ₃ ) O—, —CH ₂ CH (C ₂ H _{5 ) O -, - CH 2 C} (CH 3) 2 O -, - CH 2 CH 2 CH 2 CH 2 O- and the like. The main chain skeleton of the polyoxyalkylene polymer may be composed of only one type of repeating unit, or may be composed of two or more types of repeating units. In particular, a polymer having —CH ₂ CH (CH ₃ ) O— as the main repeating unit is preferred from the viewpoint of availability and workability. The main chain of the polymer may contain a repeating unit other than the oxyalkylene group. In this case, the total of oxyalkylene units in the polymer is preferably 80% by weight or more, and particularly preferably 90% by weight or more.

  The polymer of component A may be a linear polymer or a branched polymer, or a mixture thereof, but the adhesive layer exhibits good adhesion to various materials. Further, it is preferable to contain 50% by weight or more of a linear polymer.

  The molecular weight of the component A polymer is preferably 500 to 50,000, and more preferably 5,000 to 30,000, in terms of number average molecular weight. When the number average molecular weight is less than 500, the resulting cured product tends to be too brittle, and conversely, when the number average molecular weight exceeds 50,000, the viscosity becomes too high and the workability tends to be remarkably lowered. This is not preferable. The number average molecular weight here is a value determined by a gel permeation chromatography (GPC) method.

  Further, the polymer of component A preferably has a relatively narrow molecular weight distribution in which the ratio of the weight average molecular weight to the number average molecular weight (Mw / Mn) is 1.6 or less, and the Mw / Mn is 1.6 or less. In the polymer, the viscosity of the composition is lowered and workability is improved. Therefore, Mw / Mn is more preferably 1.5 or less, and even more preferably 1.4 or less. In addition, Mw / Mn here is a value calculated | required by the gel permeation chromatography (GPC) method.

Here, the measurement of the molecular weight by GPC method is a polystyrene conversion value measured using a GPC apparatus (HLC-8120GPC) manufactured by Tosoh Corporation, and the measurement conditions are as follows.
Sample concentration: 0.2% by weight (THF solution)
Sample injection volume: 10 μl
Eluent: THF
Flow rate: 0.6 ml / min
Measurement temperature: 40 ° C
Column: Sample column TSKgel GMH-H (S)
Detector: Differential refractometer

  In the polymer of component A (polyoxyalkylene polymer having at least one alkenyl group in one molecule), the alkenyl group is not particularly limited, but an alkenyl group represented by the following general formula (2) is preferable. It is.

General formula (2): H ₂ C═C (R ² )
(Wherein R ² is hydrogen or a methyl group)

  The bonding mode of the alkenyl group to the polyoxyalkylene polymer is not particularly limited, and examples thereof include a direct bond of an alkenyl group, an ether bond, an ester bond, a carbonate bond, a urethane bond, and a urea bond.

Specific examples of the polymer of component A include
Formula ^{_{(3): {H 2 C}} = C (R 3a) -R 4a -O} a 1 R 5a
(In the formula, R ^3a is hydrogen or a methyl group, R ^4a is a divalent hydrocarbon group having 1 to 20 carbon atoms, and one or more ether groups may be contained, and R ^5a is a polyoxy group. alkylene polymer residue, a ₁ is a positive integer.)
The polymer shown by these is mentioned. Specifically, R ^4a in the formula is —CH ₂ —, —CH ₂ C
_{H 2 -, - CH 2 CH} 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH 2 CH 2 CH 2 CH 2 -, - CH 2 CH 2 OCH 2 CH 2 -, or -CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ — and the like can be mentioned, but —CH ₂ — is preferable from the viewpoint of ease of synthesis.

In general formula ^{_{(4): {H 2 C}} = C (R 3b) -R 4b -OCO} a 2 R 5b
(In formula, R ^<3b> , R ^<4b> , R ^<5b> and a ^< ₂ > are synonymous with R ^{< 3a>} , R ^<4a> , R ^<5a> , a ^< ₁ >, respectively.
The polymer which has an ester bond shown by these is mentioned.

In general formula ^{_{(5): {H 2 C}} = C (R 3c)} a 3 R 5c
(In the formula, R ^3c , R ^5c and a ₃ have the same meanings as R ^3a , R ^5a and a ₁ , respectively.)
The polymer shown by these is also mentioned.

Moreover, the general formula ^_(6): in ^{{H 2 C = C (R} 3d) -R 4d -O (CO) O} a 4 R 5d ( ^{wherein, R 3d, R 4d, R} 5d and _{a 4,} respectively R ^3a , R ^4a , R ^5a and a ₁
Is synonymous with )
The polymer which has a carbonate bond shown by these is also mentioned.

The alkenyl group should be present in at least 1, preferably 1 to 5, more preferably 1.5 to 3 in one molecule of the component A polymer. When the number of alkenyl groups contained in one molecule of the component A polymer is less than 1, the curability is insufficient, and when the number is more than 5, the network structure becomes too dense. May not be shown. The polymer of component A can be synthesized according to the method described in JP-A-2003-292926. In addition, what is marketed may use a commercial item.

  The B component “compound containing two or more hydrosilyl groups on average in one molecule” can be used without particular limitation as long as it has a hydrosilyl group (group having a Si—H bond). From the viewpoint of ease of compatibility and compatibility with the component A, organohydrogenpolysiloxane modified with an organic component is particularly preferable. The polyorganohydrogensiloxane modified with the organic component is more preferably one having 2 to 8 hydrosilyl groups on average in one molecule. Specifically showing the structure of the polyorganohydrogensiloxane, for example,

(In the formula, 2 ≦ m ₁ + n ₁ ≦ 50, 2 ≦ m ₁ , 0 ≦ n _1. R ^6a is a hydrocarbon group having 2 to 20 carbon atoms in the main chain, and is one or more phenyl groups. Group may contain),

(In the formula, 0 ≦ m ₂ + n ₂ ≦ 50, 0 ≦ m ₂ , 0 ≦ n _2. R ^6b is a hydrocarbon group having 2 to 20 carbon atoms in the main chain, and is one or more phenyl groups. Group may contain),
Or

(In the formula, 3 ≦ m ₃ + n ₃ ≦ 20, 2 ≦ m ₃ ≦ 19, 0 ≦ n ₃ <18. R ^6c is a hydrocarbon group having 2 to 20 carbon atoms in the main chain, May contain more than one phenyl group)
The chain or ring shown by etc., and having two or more of these units,

_{(Wherein, 1 ≦ m 4 + n 4} ≦ 50,1 ≦ m 4, 0 ≦ n is ₄ ^{.R 6d} is a hydrocarbon group having 2 to 20 carbon atoms in the main chain, one or more phenyl 2 ≦ b _1. R ^8a is a divalent to tetravalent organic group, and R ^7a is a divalent organic group, provided that R ^7a depends on the structure of R ^8a . Is not necessary.)

(In the formula, 0 ≦ m ₅ + n ₅ ≦ 50, 0 ≦ m ₅ , 0 ≦ n ₅ ; R _6e is a hydrocarbon group having 2 to 20 carbon atoms in the main chain, and is one or more phenyl groups) 2 ≦ b _2. R ^8b is a divalent to tetravalent organic group, and R ^7b is a divalent organic group, provided that R ^7b depends on the structure of R ^8b . Is not necessary.), Or

(In the formula, 3 ≦ m ₆ + n ₆ ≦ 50, 1 ≦ m ₆ , 0 ≦ n _6. R ^6f is a hydrocarbon group having 2 to 20 carbon atoms in the main chain, and is one or more phenyl groups. 2 ≦ b _3. R ^8c is a divalent to tetravalent organic group, and R ^7c is a divalent organic group, provided that R ^7c depends on the structure of R ^8c . Is not necessary.)
And the like.

  The “compound having an average of two or more hydrosilyl groups in one molecule” of the B component is preferably a compound having good compatibility with the A component and the C component or good dispersion stability in the system. In particular, when the viscosity of the whole system is low, if a component having low compatibility with the above components is used as the B component, phase separation may occur and poor curing may occur.

  Specific examples of the B component having relatively good compatibility with the A component and the C component or relatively stable dispersion stability include the following.

(In the formula, n ₇ is an integer of 4 or more and 10 or less.)

(In the formula, 2 ≦ m ₈ ≦ 10, 0 ≦ n ₈ ≦ 5, and R ^6g is a hydrocarbon group having 8 or more carbon atoms.)
Preferable specific examples of the component B include polymethylhydrogensiloxane. In order to ensure compatibility with the component A and to adjust the amount of SiH, α-olefin, styrene, α-methylstyrene, allyl are used. Examples include compounds modified with alkyl ethers, allyl alkyl esters, allyl phenyl ethers, allyl phenyl esters, and the like, and examples thereof include the following structures.

(Wherein 2 ≦ m ₉ ≦ 20 and 1 ≦ n ₉ ≦ 20)

  Component B can be synthesized by a known method, but commercially available products may be used.

The “hydrosilylation catalyst” of component C is not particularly limited, and any one can be used. Specific examples include, for example, chloroplatinic acid; platinum alone; solid platinum supported on a carrier such as alumina, silica, carbon black; platinum-vinylsiloxane complex {eg, Pt _n (ViMe ₂ SiOSiMe ₂ Vi) _m , Pt [(MeViSiO) ₄ ] _m, etc.]; platinum-phosphine complex {eg, Pt (PPh ₃ ) ₄ , Pt (PBu ₃ ) ₄ etc.}; platinum-phosphite complex {eg, Pt [P (OPh) ₃ ] ₄ , Pt [P (OBu) ₃ ] ₄ etc}; Pt (acac) ₂ ; platinum-hydrocarbon complexes described in Ashby et al. US Pat. Nos. 3,159,601 and 3,159,662; Lamoreaux et al., US Pat. No. 3,220,972 And platinum alcoholate catalysts described in the above No. In these formulas, Me represents a methyl group, Bu represents a butyl group, Vi represents a vinyl group, Ph represents a phenyl group, acac represents acetylacetonato, and n and m represent integers.

Examples of catalysts other than platinum compounds include RhCl (PPh ₃ ) ₃ , RhCl ₃ , Rh / Al ₂ O ₃ , RuCl ₃ , IrCl ₃ , FeCl ₃ , AlCl ₃ , PdCl ₂ .2H ₂ O, NiCl _2. , TiCl _{4 and the} like.

These catalysts may be used alone or in combination of two or more. From the viewpoint of catalytic activity, chloroplatinic acid, platinum-phosphine complex, platinum-vinylsiloxane complex, Pt (acac) _{2 and the} like are preferable.

The amount of component C is not particularly limited, but is generally 1 × 10 ^{−1 with} respect to 1 mol of alkenyl groups in component A from the viewpoint of ensuring the pot life of the composition and the transparency of the cured product (adhesive layer). mol or less, preferably 5.3 × 10 ⁻² mol or less, and more preferably 3.5 × 10 ⁻² mol or less, particularly preferably 1.4 ×, from the viewpoint of transparency of the cured product (adhesive layer). 10 ⁻³ mol or less. When it exceeds 1 × 10 ⁻¹ mol with respect to 1 mol of the alkenyl group in the component A, the finally obtained cured product (adhesive layer) tends to yellow, and the transparency of the cured product (adhesive layer) tends to be impaired. It becomes. If the amount of component C is too small, the curing rate of the composition tends to be slow and the curability tends to become unstable. Therefore, the amount of component C is preferably 8.9 × 10 ⁻⁵ mol or more. 1.8 × 10 ⁻⁴ mol or more is more preferable.

  The composition containing the A to C components described above is cured by heating. That is, an alkenyl group in component A (polyoxyalkylene polymer having at least one alkenyl group in one molecule) has an average of 2 in one molecule of component B in the presence of a hydrosilylation catalyst (component C). Curing is achieved by hydrosilylation with a hydrosilyl group (a group having a Si-H bond) of a compound having one or more hydrosilyl groups, and a crosslinked structure proceeds. Such a cured product has a feature that it can exhibit adhesive properties (adhesive function to other objects) even when no tackifying resin is added or in a small amount. In addition, its activity is low, and it does not react even when it comes into contact with various substances such as water, metal, and plastic materials.

  In the composition containing the components A to C, the component A and the component B are such that the hydrosilyl group of the component B (compound B) has a functional group ratio of 0.3 or more to the alkenyl group of the component A (compound A). It is preferable to mix | blend so that it may become less, More preferably, it is the range of 0.4 or more and less than 1.8, More preferably, it is the range of 0.5 or more and less than 1.5. When the functional group ratio exceeds 2, the crosslink density increases, and it may become impossible to obtain tackiness when no tackifying resin is added or when a small amount is added. On the other hand, when the functional group ratio is less than 0.3, crosslinking in the cured product becomes too loose, and it may be difficult to maintain characteristics at high temperatures. Thus, by selecting the blending ratio of the A component and the B component within a specific range, the composition can exhibit good adhesive properties without blending the tackifier resin, and the composition is practically sufficient. The pressure-sensitive adhesive sheet can be obtained while being cured at a high line speed.

(Non-halogen flame retardant)
In the present invention, the non-halogen flame retardant is not particularly limited, and includes a known halogen atom-free flame retardant such as a hydrated metal compound system, an inorganic compound system, a phosphorus system, a silicone system, a nitrogen compound system, and an organometallic compound system. Can be used. Among these, phosphorus-based flame retardants are preferable in that they are excellent in the effect of imparting flame retardancy, suppression of drip during combustion, compatibility with environmental regulations, and the like.

Examples of the hydrated metal compound flame retardant include aluminum hydroxide, magnesium hydroxide, calcium hydroxide and the like. Inorganic compound flame retardants include antimony compounds, zinc borate, zinc stannate, molybdenum compounds, zinc oxide, zinc sulfide, zeolite, titanium oxide, nanofillers (montmorillonite (MMT), nanohydrated metal compounds, silica). , Carbon nanotubes, calcium carbonate and the like.

  Examples of phosphorus flame retardants include phosphate esters, aromatic condensed phosphate esters, and ammonium polyphosphates. Specific examples of phosphate esters include triphenyl phosphate, tricresyl phosphate (TCP), cresyl diphenyl phosphate (CDP), 2-ethylhexyl diphenyl phosphate, triethyl phosphate (TEP), tri n-butyl phosphate, trixylate. Nyl phosphate, xylenyl diphenyl phosphate (XDP) and the like can be mentioned. Specific examples of the aromatic condensed phosphates include resorcinol bisdiphenyl phosphate, bisphenol A bis (diphenyl phosphate), resorcinol bisdixylenyl phosphate, and the like. Specific examples of ammonium polyphosphates include ammonium polyphosphate (APP), melamine-modified ammonium polyphosphate, and coated ammonium polyphosphate. Here, the coated ammonium polyphosphate is water-resistant by coating or microencapsulating ammonium polyphosphate with a resin. In addition, phosphate ester, aromatic condensed phosphate ester, and ammonium polyphosphate can be used together. Above all, phosphoric acid can be made flame retardant both in the solid phase and in the gas phase by combining the flame retardant effect of carbonized layer formation with phosphate esters and the flame retardant effect of incombustible gas generation with ammonium polyphosphates. The combined use of esters and ammonium polyphosphates is preferred.

  Examples of the silicone flame retardant include dimethyl silicone, amino-modified silicone, and epoxy-modified silicone.

  Examples of the nitrogen compound flame retardant include hindered amine compounds, melamine cyanurates, triazine compounds, and guanidine compounds.

  Examples of the organometallic compound flame retardant include ethylenediaminetetraacetic acid copper acetate and calcium perfluorobutanesulfonate.

  One or two or more non-halogen flame retardants can be used in combination. In addition, although the amount used varies depending on the type of flame retardant, generally, from the viewpoint that flame retardancy is imparted, drip suppression effect due to carbonized layer formation and the like can be obtained more effectively, 100 parts by weight of the adhesive. The amount is preferably 10 parts by weight or more, more preferably 20 parts by weight or more, and particularly preferably 30 parts by weight or more. Moreover, from a viewpoint that a more favorable adhesive characteristic, preservability, etc. are obtained, 350 weight part or less is preferable, 250 weight part or less is more preferable, 150 weight part or less is especially preferable.

(Tackifying resin)
In the present invention, the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1 can contain a tackifier resin in order to improve the adhesion of the gasket to the adherend and the flame retardancy. Examples of the tackifier resin include terpene tackifier resins, phenol tackifier resins, rosin tackifier resins, and petroleum tackifier resins. One or more tackifying resins can be used.

  Examples of terpene-based tackifier resins include terpene resins such as α-pinene polymers, β-pinene polymers, dipentene polymers, and modified terpene resins (phenol-modified, aromatic-modified, hydrogenated-modified). Modified terpene resins such as terpene phenol resins, styrene modified terpene resins, aromatic modified terpene resins, hydrogenated terpene resins, and the like.

  Examples of phenolic tackifying resins include condensates of various phenols (eg, phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcin, etc.) with formaldehyde (eg, alkylphenolic resin, xyleneformaldehyde resin). And the like, and resols obtained by addition reaction of the phenols and formaldehyde with an alkali catalyst, and novolaks obtained by condensation reaction of the phenols and formaldehyde with an acid catalyst.

  Examples of rosin-based tackifying resins include unmodified rosins (raw rosins) such as gum rosin, wood rosin, tall oil rosin, and modified rosin (water) modified by hydrogenation, disproportionation, polymerization, etc. Rosin, disproportionated rosin, polymerized rosin, other chemically modified rosins, etc.) and various rosin derivatives. Examples of the rosin derivatives include rosin ester compounds obtained by esterifying unmodified rosin with alcohols, modified rosin ester compounds obtained by esterifying modified rosins such as hydrogenated rosin, disproportionated rosin, and polymerized rosin with alcohols. Rosin esters such as: Unmodified rosin and modified rosins (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.) modified with unsaturated fatty acids; Unsaturated fatty acid modified rosins; Rosin esters modified with unsaturated fatty acids Unsaturated fatty acid-modified rosin esters: Reduced carboxyl groups in unmodified rosin, modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.), unsaturated fatty acid-modified rosins or unsaturated fatty acid-modified rosin esters Rosin alcohols; unmodified rosin, modified rosin, various rosin derivatives, etc. Oxazines (especially, rosin esters) and the like metal salts of. In addition, as the rosin derivative, a rosin phenol resin obtained by adding phenol to an rosin (unmodified rosin, modified rosin, various rosin derivatives, etc.) with an acid catalyst and thermal polymerization can be used.

  The alcohols used in obtaining the rosin esters are dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and neopentyl glycol, trihydric alcohols such as glycerin, trimethylolethane, and trimethylolpropane, penta Examples thereof include tetrahydric alcohols such as erythritol and diglycerin, and hexahydric alcohols such as dipentaerythritol, and these are used alone or in combination of two or more.

Examples of petroleum-based tackifier resins include aromatic petroleum resins, aliphatic petroleum resins, alicyclic petroleum resins (aliphatic cyclic petroleum resins), aliphatic / aromatic petroleum resins, aliphatic / alicyclic rings. Known petroleum resins such as group petroleum resins, hydrogenated petroleum resins, coumarone resins and coumarone indene resins can be used. Specifically, as the aromatic petroleum resin, for example, a vinyl group-containing aromatic hydrocarbon having 8 to 10 carbon atoms (styrene, o-vinyltoluene, m-vinyltoluene, p-vinyltoluene, α -Methyl styrene, β-methyl styrene, indene, methyl indene, etc.) are used alone or in combination of two or more. As the aromatic petroleum resin, an aromatic petroleum resin (so-called “C9 petroleum resin”) obtained from a fraction such as vinyltoluene or indene (so-called “C9 petroleum fraction”) can be preferably used. The aliphatic petroleum resin is selected from dienes such as olefins having 4 to 5 carbon atoms (for example, butene-1, isobutylene, pentene-1, etc.), butadiene, piperylene, 1,3-pentadiene, isoprene and the like. And polymers obtained by using one or more of them. In addition, as the aliphatic petroleum resin, an aliphatic petroleum resin (so-called “C4 petroleum”) obtained from a fraction such as butadiene, piperylene, isoprene (so-called “C4 petroleum fraction”, “C5 petroleum fraction”, etc.). Resin "," C5-based petroleum resin ", etc.) can be suitably used. As the alicyclic petroleum resin, for example, an alicyclic hydrocarbon obtained by cyclizing and dimerizing an aliphatic petroleum resin (so-called “C4 petroleum resin”, “C5 petroleum resin”, etc.) is used. Polymers, cyclic diene compounds (cyclopentadiene, dicyclopentadiene, ethylidene norbornene, dipentene, ethylidenebicycloheptene, vinylcycloheptene, tetrahydroindene, vinylcyclohexene, limonene, etc.) or hydrogenated products thereof, And alicyclic hydrocarbon resins obtained by hydrogenating aromatic rings of the following aliphatic hydrocarbon resins and aliphatic / aromatic petroleum resins. Examples of the aliphatic / aromatic petroleum resins include styrene-olefin copolymers. As the aliphatic / aromatic petroleum resin, so-called “C5 / C9 copolymer petroleum resin” or the like can be used.

  In the present invention, the tackifier resin is preferably a terpene tackifier resin and / or a rosin tackifier resin, particularly preferably a rosin tackifier resin, from the viewpoint of flame retardancy of the gasket. Terpene-based tackifier resins and rosin-based tackifier resins are likely to be effective as flame retardant aids, and by using these, the flame retardancy of the gasket is more pronounced as well as the adhesion of the gasket to the adherend. Can be improved. The terpene-based tackifier resin is particularly preferably a terpene phenol resin, and the rosin-based tackifier resin is particularly preferably a rosin ester (that is, an ester of an unmodified rosin, hydrogenated rosin, disproportionated rosin or polymerized rosin). The rosin ester is preferably a trihydric or higher polyhydric alcohol ester, particularly preferably a tetravalent to hexavalent polyhydric alcohol ester.

  The tackifying resin can be used alone or in combination of two or more, and the amount used is not particularly limited. However, from the viewpoint that the effect as an auxiliary of the phosphorus flame retardant is sufficiently exhibited as a carbon source. 5 parts by weight or more is preferable with respect to 100 parts by weight of the agent, 10 parts by weight or more is more preferable, and 15 parts by weight or more is particularly preferable. In addition, from the viewpoint of maintaining adhesive properties, storage stability, handling properties, dispersibility, and the like, the amount is preferably 100 parts by weight or less, more preferably 60 parts by weight or less, and particularly preferably 40 parts by weight or less.

  In the present invention, the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1 may be provided with a filler, pigment, colorant, antioxidant, which is made of a plasticizer, glass fiber, glass beads, metal powder, or other inorganic powder, as necessary. In addition, various additives such as an ultraviolet absorber can be appropriately blended.

  Moreover, in the gasket of the aspect which has the base film 2, in order to improve the adhesiveness with the base film 2 to the halogen-free flame retardant containing adhesive sheet 1, an adhesion imparting agent can be added. Examples of the adhesion imparting agent include various silane coupling agents and epoxy resins. Among them, a silane coupling agent having a functional group such as an epoxy group, a methacryloyl group, or a vinyl group is preferable because it has a large effect on the expression of adhesiveness. Moreover, the catalyst for making a silyl group or an epoxy group react can be added together with a silane coupling agent and an epoxy resin. In the case of a non-halogen flame retardant-containing pressure-sensitive adhesive sheet using a polyoxyalkylene-based pressure-sensitive adhesive (pressure-sensitive adhesive made of a cured product of the composition containing the components A to C) as the pressure-sensitive adhesive, the catalyst generates a pressure-sensitive adhesive. The influence on the curing reaction (hydrosilylation reaction) must be taken into account.

In the case of a non-halogen flame retardant-containing pressure-sensitive adhesive sheet using a polyoxyalkylene pressure-sensitive adhesive as the pressure-sensitive adhesive, a storage stability improver may be added for the purpose of improving storage stability. As the agent, a known compound known as a storage stabilizer for the component B can be used without limitation. For example, a compound containing an aliphatic unsaturated bond, an organic phosphorus compound, an organic sulfur compound, a nitrogen-containing compound, a tin compound, an organic peroxide, or the like can be preferably used. Specifically, 2-benzothiazolyl sulfide, benzothiazole, thiazole, dimethylacetylene dicarboxylate, diethylacetylene dicarboxylate, 2,6-di-t-butyl-4-methylphenol, butylhydroxyanisole, vitamin E, 2- (4-morpholinyldithio) benzothiazole, 3-methyl-1-buten-3-ol, 2-methyl-3-buten-2-ol, acetylenically unsaturated group-containing organosiloxane, acetylene alcohol , 3-methyl-1-butyl-3-ol, diallyl fumarate, diallyl maleate, diethyl fumarate, diethyl maleate, dimethyl maleate, 2-pentenenitrile, 2,3-dichloropropene, and the like. It is not limited to these.

(Base film)
In the gasket of the present invention, the base film 2 gives self-supporting property to the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1 to improve the mounting workability of the gasket, and more strictly contact moisture to the adherend. It is provided to prevent That is, when the adhesive surface of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet is in direct contact with the adherend, moisture absorbed by the non-halogen flame retardant-containing pressure-sensitive adhesive sheet due to long-term use of the gasket comes into contact with the adherend. When the metal member is not subjected to anticorrosion treatment or the like, the metal member may be corroded or discolored, and the intended function of the adherend may be impaired. Therefore, as shown in FIG. 2, of the two adherends 20 and 21 to which the gasket is closely attached, the adherend 21 on the side where corrosion and discoloration should be prevented at a higher level is non-halogen-based. The surface 2A of the base film 2 laminated on one main surface of the flame-retardant-containing pressure-sensitive adhesive sheet 1 is brought into close contact.

  Therefore, in the present invention, the base film 2 is preferably a film not only having the heat resistance required for the gasket, but also having excellent water repellency and / or a material having high moisture permeability, For example, polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), perfluoroalkoxy fluororesin (PFA), tetrafluoroethylene / hexafluoropropylene A plastic film made of a fluororesin such as a copolymer (FEP), an ethylene / tetrafluoroethylene copolymer (ETFE), an ethylene / chlorotrifluoroethylene copolymer (ECTFE), or a silicone resin is particularly preferable. A fluororesin film, particularly preferably Li polytetrafluoroethylene (PTFE) is a film.

  The thickness of the base film 2 is preferably about 10 to 500 μm, more preferably 50 to 300 μm, and more preferably 100 to 200 μm from the viewpoint of improving the good adhesion of the gasket to the adherend and the peeling workability during maintenance. Is particularly preferred.

  Further, the surface of the base film 2 on the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1 side is preferably subjected to corona treatment, sputtering treatment, sodium treatment, etc. for improving the adhesion between the pressure-sensitive adhesive sheet and the base material, These surface treatments can be performed in combination of two or more.

(Core film)
The core film 3 used when the gasket of the present invention is in the form of a core-containing pressure-sensitive adhesive sheet shown in FIG. 3 is not particularly limited, and is polyester (for example, polyethylene terephthalate (PET)); nylon; Polyvinyl chloride; polyvinylidene chloride; polyolefin (eg, polyethylene, polypropylene, reactor TPO, ethylene-vinyl acetate copolymer, etc.); fluororesin (eg, polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), Polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), perfluoroalkoxy fluororesin (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), ethylene / tetrafluoroethylene copolymer (ETFE) , Ethylene chlorotrif Examples thereof include a film (single layer film) made of one or two or more kinds of plastics selected from an ethylene copolymer (ECTFE) and the like, a metal foil, or a laminate film in which two or more selected from these are laminated. It is done. These films may be used in the form of a solid film (non-porous film) or may be used as a perforated film that has been mechanically perforated. In addition, a knitted fabric using one or more fibers selected from synthetic polymer fibers such as polyester (for example, polyethylene terephthalate (PET)), natural fibers such as cotton and hemp, metal fibers, and glass fibers, A fiber sheet (single layer sheet, two or more laminated sheets) such as a woven fabric or a nonwoven fabric, or a laminate obtained by laminating one or two or more of such fiber sheets on the plastic film is also used as the core film 3. Can be used.

Among these, from the viewpoint of moisture permeation resistance (moisture barrier property), those having few air holes through which moisture passes are preferable, and nonporous plastic films are particularly preferable. Moreover, it is preferable that a plastic film has transparency from a viewpoint of workability | operativity. When bolting is performed after the gasket is placed, a glass fiber sheet (particularly glass cloth) is preferable for the core film from the viewpoints of workability at the time of bolting and imparting strength at the time of peeling. The basis weight of the glass fiber sheet is preferably in the range of 5 to 1000 g / m ² from the viewpoint of strength and transparency, and the thickness (diameter) of the glass fiber is preferably about 0.01 to 1 mm. . In the case of glass cloth, examples of the glass cloth include plain weave, satin weave, twill weave and nanako weave. Moreover, the glass cloth can improve adhesiveness with an adhesion layer by surface-treating with a silane coupling agent.

  The thickness of the core film varies depending on the material and form of the film (sheet), but is generally selected from the range of 10 to 200 μm, preferably 30 to 150 μm, and most preferably 50 to 100 μm.

In the gasket of the present invention, the method for producing the non-halogen flame retardant-containing pressure-sensitive adhesive sheet is not particularly limited, and a general method for producing a pressure-sensitive adhesive sheet can be applied.
Preparation of a non-halogen flame retardant-containing pressure-sensitive adhesive sheet using an acrylic pressure-sensitive adhesive is, for example, a photopolymerizable composition obtained by blending a main skeleton monomer and a copolymerization monomer of a base polymer with a radical polymerization initiator, a crosslinking agent, etc. A non-halogen flame retardant is further mixed with the product, and it is applied onto the release treatment surface of the release sheet so as to form a coating film of a predetermined thickness. The method of forming an adhesive sheet by irradiating an ultraviolet-ray and making a polymerization reaction advance is mentioned. When the non-halogen flame retardant-containing pressure-sensitive adhesive sheet contains a tackifier resin and other additives, they may be mixed with the photopolymerizable composition together with the non-halogen flame retardant. Moreover, when obtaining the gasket of the aspect which has a base film, it uses the base film instead of a release sheet, and the above except apply | coating the photopolymerizable composition containing a non-halogen flame retardant etc. on a base film In the same manner as described above, a non-halogen flame retardant-containing pressure-sensitive adhesive sheet may be formed.

  For non-halogen flame retardant-containing pressure-sensitive adhesive sheets using silicone-based pressure-sensitive adhesive, a silicone pressure-sensitive adhesive mixed with non-halogen flame retardant is applied on the release sheet surface of the release sheet, and then the release sheet is peeled off. It can be formed by bonding the surfaces and performing predetermined heat drying. When obtaining a gasket having an aspect having a base film, the base film is used instead of the release sheet, and the same as above except that a photosilicone adhesive containing a non-halogen flame retardant is applied on the base film. Thus, a non-halogen flame retardant-containing pressure-sensitive adhesive sheet may be formed.

  In both the production of non-halogen flame retardant-containing pressure-sensitive adhesive sheets using acrylic pressure-sensitive adhesives and non-halogen flame retardant-containing pressure-sensitive adhesive sheets using silicone-based pressure-sensitive adhesives, the release treatment of the release sheet requires silicone-based peeling. A general release agent such as an agent and a fluorine-based release agent can be appropriately used.

A non-halogen flame retardant-containing pressure-sensitive adhesive sheet using a polyoxyalkylene pressure-sensitive adhesive is produced, for example, by the following method. First, the above-described components A to C and the non-halogen flame retardant (D component) are charged into an agitator equipped with a vacuum function together with an organic solvent as necessary, and defoamed by stirring in a vacuum state (under vacuum). Then, a defoamed mixture (composition) is prepared. When the non-halogen flame retardant-containing pressure-sensitive adhesive sheet contains a tackifier resin and other additives, a mixture (composition) is prepared by adding the tackifier resin and other additives together with the components A to D. Next, a composition (mixture) containing the components A to D after the defoaming treatment is applied on the release treatment surface of the release sheet so as to form a coating film having a predetermined thickness, and the release sheet is peeled thereon. The treated surfaces are bonded together, and a predetermined heat treatment is performed to cure the composition (mixture) containing components A to D. In the curing reaction, the alkenyl group in component A (polyoxyalkylene polymer having at least one alkenyl group in one molecule) is converted into one molecule of component B in the presence of a hydrosilylation catalyst (component C). This is achieved by hydrosilylation of a compound having an average of two or more hydrosilyl groups with a hydrosilyl group (a group having a Si—H bond) to proceed with a crosslinked structure. When obtaining the gasket of the aspect which has a base film, except using a base film instead of a release sheet and apply | coating the composition (mixture) containing AD component after a defoaming process on a base film In the same manner as described above, a non-halogen flame retardant-containing pressure-sensitive adhesive sheet may be formed.

  The mixture can be applied by a known coating apparatus such as a roll coater such as gravure, kiss, or comma, a die coater such as slot or phanten, a squeeze coater, or a curtain coater. The heat treatment is preferably performed at 50 to 200 ° C. (preferably 100 to 160 ° C.) for about 0.01 to 24 hours (preferably 0.05 to 4 hours). In addition, what is necessary is just to use the well-known stirring apparatus with a vacuum apparatus as a stirring apparatus provided with the vacuum function, and specifically, a planetary type (revolution / autorotation system) stirring deaerator, a deaerator with a disper, etc. are used. Can be mentioned. Moreover, as a grade of the pressure reduction at the time of performing vacuum defoaming, 10 kPa or less is preferable and 3 kPa or less is more preferable. Moreover, although stirring time changes with stirrers and the processing amount of a fluid, about 0.5 to 2 hours are preferable in general. By the defoaming treatment, the formed adhesive layer is substantially free from bubbles (voids), whereby high transparency is obtained.

  For the release treatment of the release sheet, a silicone release agent, a fluorine release agent, a long-chain alkyl release agent, or the like can be used. Among them, a silicone release agent is preferable, and a curing method is ultraviolet irradiation, electron beam irradiation, or the like. It is preferable to use this curing method. Furthermore, among the silicone-based release agents, cationically polymerizable UV-curable silicone-type release agents are preferable. Cationic polymerizable UV curable silicone release agent is a mixture containing cationic polymerization type silicone (polyorganosiloxane having epoxy functional group in the molecule) and onium salt photoinitiator, but onium salt photoinitiator It is particularly preferable that the agent is made of a boron photoinitiator, and it is particularly good when such an onium salt photoinitiator is a cationic polymerizable UV curable silicone release agent comprising a boron photoinitiator. Peelability (release property) is obtained. The cationic polymerization type silicone (polyorganosiloxane having an epoxy functional group in the molecule) has at least two epoxy functional groups in one molecule, and is linear or branched or A mixture thereof may be used. The type of epoxy functional group contained in the polyorganosiloxane is not particularly limited as long as ring-opening cationic polymerization proceeds with an onium salt photoinitiator. Specific examples include γ-glycidyloxypropyl group, β- (3,4-epoxycyclohexyl) ethyl group, β- (4-methyl-3,4 epoxy cyclohexyl) propyl group and the like. Such cationic polymerization type silicone (polyorganosiloxane having an epoxy functional group in the molecule) is commercially available, and a commercially available product can be used. For example, UV9315, UV9430, UV9300, TPR6500, TPR6501 manufactured by Toshiba Silicone Co., Ltd., X-62-7622, X-62-7629, X-62-7655, X-62-7660, X-62-7660 manufactured by Shin-Etsu Chemical Co., Ltd. Examples thereof include Poly200, Poly201, RCA200, RCA250, and RCA251 manufactured by Arakawa Chemical Co., Ltd.

  Among the cationic polymerizable silicones, polyorganosiloxanes comprising the following structural units (A) to (C) are particularly preferable.

  Further, in the polyorganosiloxane composed of the structural units (A) to (C), the composition ratio ((A) :( B) :( C)) of the structural units (A) to (C) is 50 to 95: What is 2-30: 1-30 (mol%) is especially preferable, and what is 50-90: 2-20: 2-20 (mol%) is especially preferable. In addition, the polyorganosiloxane which consists of this structural unit (A)-(C) can be obtained as Poly200, Poly201, RCA200, X-62-7622, X-62-7629, X-62-7660.

On the other hand, known onium salt photoinitiators can be used without particular limitation. Specific examples include, for example, (R ¹ ) ₂ I ⁺ X ⁻ , ArN ₂ ⁺ X ⁻ , or (R ¹ ) ₃ S ⁺ X ⁻ , wherein R ¹ is an alkyl group and / or an aryl group. the, Ar is an aryl group, X ^- is _{[B (C 6 H 5)} 4] -, [B (C 6 F 5) 4] -, [B (C 6 H 4 CF 3) 4] -, [ (
C ₆ F ₅ ) ₂ BF ₂ ] ⁻ , [C ₆ F ₅ BF ₃ ] ⁻ , [B (C ₆ H ₃ F ₂ ) ₄ ] ⁻ , BF ₄ ⁻ ,
PF ₆ ⁻ , AsF ₆ ⁻ , HSO ₄ ⁻ , ClO ₄ ^{− and the} like are shown. ), Among these, X ^{− in} the formula is [B (C ₆ H ₅ ) ₄ ] ⁻ , [B (C ₆ F ₅ ).
₄ ] ⁻ , [B (C ₆ H ₄ CF ₃ ) ₄ ] ⁻ , [(C ₆ F ₅ ) ₂ BF ₂ ] ⁻ , [C ₆ F ₅ BF ₃ ] ⁻
, [B (C ₆ H ₃ F ₂ ) ₄ ] ⁻ or BF ₄ ^— (boron-based photoinitiator) is preferable, and (R ¹ ) ₂ I ⁺ [B (C ₆ F ₅ ) ₄ is particularly preferable. (Wherein R ¹ represents a substituted or unsubstituted phenyl group) (alkyliodonium, tetrakis (pentafluorophenyl) borate). As an onium salt photoinitiator, an antimony (Sb) -based initiator has been conventionally known. However, when an antimony (Sb) -based initiator is used, heavy peeling occurs, and the transparent adhesive sheet is released. It tends to be difficult to peel off from the sheet.

  The amount of the onium salt photoinitiator used is not particularly limited, but is preferably about 0.1 to 10 parts by weight with respect to 100 parts by weight of the cationic polymerization type silicone (polyorganosiloxane). If the amount used is less than 0.1 parts by weight, the silicone release layer may be insufficiently cured. If the amount used is more than 10 parts by weight, it is not practical in terms of cost. When the cationic polymerization type silicone (polyorganosiloxane) and the onium salt photoinitiator are mixed, the onium salt initiator may be dissolved or dispersed in an organic solvent and mixed with the polyorganosiloxane. Specific examples of the organic solvent include alcohol solvents such as isopropyl alcohol and n-butanol; ketone solvents such as acetone and methyl ethyl ketone; ester solvents such as ethyl acetate.

Application | coating of a peeling process agent can be performed using general coating apparatuses, such as a roll coater method, a reverse coater method, a doctor blade method, for example. The application amount (solid content) of the release treatment agent is not particularly limited, but is generally about 0.05 to 6 mg / cm ² .

  As shown in FIGS. 4 (A) and 4 (B), the gasket of the present invention is preferably configured as a roll-shaped object 100 before being mounted between two mating surfaces. In this case, the base film 2 is a film that has undergone a peeling treatment on the back surface (one surface opposite to the surface on which the non-halogen flame retardant-containing pressure-sensitive adhesive sheet 1 is formed). In addition, the code | symbol 4 in a figure is a release sheet.

When the non-halogen flame retardant-containing pressure-sensitive adhesive sheet is in the form of the pressure-sensitive adhesive sheet with a core shown in FIG. 3, the gasket of the present invention is produced by the method shown in FIG.
First, the halogen-free flame retardant-containing adhesive layer 1b is formed on one surface of the base film 2, and the core film 3 is bonded to the halogen-free flame retardant-containing adhesive layer 1b (FIG. 5A).

  A release sheet 4 is prepared, and a non-halogen flame retardant-containing adhesive layer 1a is formed on one surface of the release sheet 4 (FIG. 5B).

  The non-halogen flame retardant-containing adhesive layer 1a formed on one surface of the release sheet 4 is bonded to one surface (adhesive layer non-formed surface) of the core film 3 (FIG. 5C).

  The gasket of the present invention is interposed between the mating surfaces of the two surfaces, and a bolt is passed through a through hole formed at a predetermined position and bolted to seal the two mating surfaces without a gap.

  The gasket of the present invention can be used to seal between two mating surfaces in machines, equipment and structures of various technical fields. For example, the main body of an aircraft, a car, a train, or the like, or a part where various devices or equipment are mounted on the outer plate (body) of the vehicle, an aircraft, a car, a train, etc. And a structural part that is fixed by facing each other (that is, by forming a mating surface of two surfaces). In particular, since it has high flame retardancy and does not corrode metals, it is particularly advantageous as an aircraft material.

  When the gasket of the present invention is a gasket formed using a non-halogen flame retardant-containing pressure-sensitive adhesive sheet using a polyoxyalkylene-based pressure-sensitive adhesive, the main surface (adhesive surface) of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet is the adherend. Adhesive strength (peeling force) increases over time after being applied to the surface, so that even better sealing performance can be obtained, and even if it is applied to the adherend for a long time, the adhesive strength (peeling force) is excessive. Since it does not rise, it is preferable because the gasket can be easily detached from the adherend during maintenance.

Moreover, the non-halogen flame retardant-containing pressure-sensitive adhesive sheet using a polyoxyalkylene pressure-sensitive adhesive has a shear storage elastic modulus (G ′) at −30 ° C. of 6.0 × 10 ⁵ (Pa) or less, preferably 5.5. × 10 ⁵ (Pa) or less is shown. The shear storage modulus (G ′) is known as an index of the hardness of the viscoelastic body, but the non-halogen flame retardant-containing pressure-sensitive adhesive sheet using a polyoxyalkylene pressure-sensitive adhesive has a shear storage modulus (G ') Is 6.0 × 10 ⁵ (Pa) or less, and since it does not become rigid at low temperatures, it is considered that high flexibility is maintained even at temperatures below freezing. In consideration of the temperature-time conversion rule, the characteristics of the viscoelastic body at a lower temperature influence the high-speed deformation at a certain temperature. Therefore, when discussing the adhesive strength at −30 ° C., it is necessary to consider viscoelastic behavior at a lower temperature. The non-halogen flame retardant-containing pressure-sensitive adhesive sheet using the polyoxyalkylene pressure-sensitive adhesive in the gasket of the present invention also has a shear storage modulus at −50 ° C. of 6.0 × 10 ⁵ or less. Therefore, it is considered that the adhesion stability at a low temperature is very excellent. The “shear storage modulus (G ′)” here is measured by the following method.

[Shear storage modulus (G ')]
A plurality of samples in which an adhesive layer is formed on the release treatment surface of the release sheet are prepared, and the obtained adhesive layers are bonded together to obtain a laminate having a thickness of about 0.5 to 1 mm. The laminate is punched into a circle having a diameter of 7.9 mm, and a measurement sample is used.
Measuring device: ARES manufactured by Rheometric Scientific
Measurement conditions: Measurement temperature -30 ° C and -50 ° C
Measurement frequency: 1 Hz (6.28 rad / sec)

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In addition, the physical property evaluation test of the gasket of an Example and a comparative example was done with the following method.

1. Initial adhesive strength to SUS plate A PET film having a thickness of 25 μm was bonded to the adhesive layer on one side of the gasket, and cut into a width of 25 mm to prepare a sample. The other adhesive layer of the sample was attached to a SUS304 plate by reciprocating a 2 kg roller, and left at room temperature for 30 minutes. After that, using a tensile tester, the initial adhesive strength was 300 mm / min and the peel angle was 180 °. Was measured.

2. Removability A 25 μm thick PET film was bonded to one side (adhesive side) of the gasket and cut to a width of 25 mm to prepare a sample. When the other adhesive layer of the sample was attached to the SUS304 plate by reciprocating a 2 kg roller once, and left in an environment of temperature: 23 ° C. and humidity: 65% RH for 240 hours, the sample was peeled off from the SUS plate by hand. The gasket breaking condition was observed. At this time, the case where the gasket peels off at the interface with the adherend without breaking (PASS), the case where the gasket breaks and the adhesive layer remains on the adherend is rejected (×) did.

3. Combustion test Compliant with UL standard “UL-94”.
That is, three types of samples having a length of 5 inches × width of 1 inch, a maximum thickness, a minimum thickness, and an intermediate thickness were prepared and tested under the following conditions. In addition, 5 samples were prepared for each of the maximum, minimum, and intermediate thicknesses, and the test was performed on a total of 15 samples.
Test atmosphere: In the air Ignition: 10 seconds Test procedure: After 10 seconds of flame contact, remove the test flame and record the flaming and glowing time. If the fire stops within 30 seconds, flame contact for another 10 seconds.

(Evaluation criteria)
Compliant with UL standard “UL-94”. Evaluation by grade (5VA, 5VB, V-0, V-1, V-2, HB).

4). Metal corrosivity A 1 inch × 1 inch size gasket was stuck on a copper plate and left under humid conditions (40 ° C. × 92% atmosphere) for 100 hours. After taking out from humidification conditions, the gasket was peeled off, the surface of the copper plate was observed, and the presence or absence of discoloration was visually confirmed.
The case where no discoloration was observed was judged as good (◯), the case where slight discoloration was observed was accepted (Δ), and the case where discoloration was remarkable was judged as impossible (×).

5. Halogen content Conforms to JISK0127.
If a halogen such as Cl or Br of 5 ppm or more was detected, it was rejected (x), and if the detected amount was less than 5 ppm, it was determined to be acceptable (◯).

Example 1
A component polyoxyalkylene polymer, B component hydrosilyl compound (the amount of the hydrosilyl group is 1: 2 in terms of the functional group ratio to the alkenyl group amount of the component A polyoxyalkylene polymer) , C component hydrosilylation catalyst (0.04 mol relative to 1 mol of alkenyl group in component A), D component (non-halogen flame retardant) tricresyl phosphate (TCP) (A to C components) 50 parts by weight with respect to 100 parts by weight of the total amount) and a composition containing rosin pentaerythritol (25 parts by weight per 100 parts by weight of the total amount of the components A to C) on the release-treated surface of the release sheet made of polyethylene terephthalate film Apply, heat-treat at 130 ° C for 10 minutes, and overlie the release treatment surface of the release sheet made of polyethylene terephthalate film. Te, to form a pressure-sensitive sheet having a thickness of 1000 .mu.m.

Example 2
Instead of tricresyl phosphate (TCP), an adhesive sheet was prepared in the same manner as in Example 1 except that ammonium polyphosphate (APP) (50 parts by weight with respect to 100 parts by weight of the total amount of components A to C) was used. Formed.

Example 3
A pressure-sensitive adhesive sheet was formed in the same manner as in Example 1 except that 25 parts by weight of tricresyl phosphate (TCP) and 25 parts by weight of ammonium polyphosphate (APP) were used with respect to 100 parts by weight of the total amount of components A to C. did.

Example 4
The composition containing components A to C, tricresyl phosphate (TCP) and rosin pentaerythritol used in Example 1 was applied to the release-treated surface of the release sheet made of polyethylene terephthalate film, and the composition was applied at 130 ° C. for 10 minutes. It heat-processed and the polytetrafluoroethylene film (thickness: 130 micrometers) sodium treatment surface was piled up on it, and the 1000-micrometer-thick adhesive sheet was formed.

Example 5
The composition containing A to C components, ammonium polyphosphate (APP) and rosin pentaerythritol used in Example 2 was applied to the release-treated surface of the release sheet made of polyethylene terephthalate film and heated at 130 ° C. for 10 minutes. Treatment, A sodium-treated surface of a polytetrafluoroethylene film (thickness: 130 μm) was stacked thereon to form an adhesive sheet having a thickness of 1000 μm.

Example 6
The composition containing the components A to C, tricresyl phosphate (TCP), ammonium polyphosphate (APP), and rosin pentaerythritol used in Example 3 was applied to the release-treated surface of the release sheet made of polyethylene terephthalate film. Then, heat treatment was performed at 130 ° C. for 10 minutes, and a sodium-treated surface of a polytetrafluoroethylene film (thickness: 130 μm) was stacked thereon to form an adhesive sheet having a thickness of 1000 μm.

Example 7
The composition containing the components A to C, tricresyl phosphate (TCP) and terpene phenol (25 parts by weight per 100 parts by weight of the total amount of the components A to C) used in Example 1 was released from the polyethylene terephthalate film. The pressure-sensitive adhesive sheet having a thickness of 1000 μm was formed by coating the sheet peeling-treated surface, heating at 130 ° C. for 10 minutes, and superposing the sodium-treated surface of the polytetrafluoroethylene film (thickness: 130 μm) thereon.

Example 8
1 part by weight of an isocyanate-based crosslinking agent (Coronate L-45 manufactured by Nippon Polyurethane Co., Ltd., solid content: 45%) and tricresyl phosphate (butyl acrylate copolymer solution and 100 parts by weight of butyl acrylate copolymer solution) A composition containing 50 parts by weight per 100 parts by weight of the total amount of isocyanate-based crosslinking agent) and rosin pentaerythritol (25 parts by weight per 100 parts by weight of the total amount of butyl acrylate copolymer solution and isocyanate-based crosslinking agent) A release sheet made of terephthalate film was coated on the release surface, heat-treated at 80 ° C. for 3 minutes, and a sodium-treated surface of a polytetrafluoroethylene film (thickness: 130 μm) was stacked thereon to form an adhesive sheet having a thickness of 1000 μm. Formed.

Example 9
A pressure-sensitive adhesive sheet was formed in the same manner as in Example 8 except that terpene phenol (25 parts by weight with respect to 100 parts by weight of the total components A to C) was used instead of rosin pentaerythritol.

Example 10
A composition containing tricresyl phosphate (50 parts by weight per 100 parts by weight of the cyclohexyl acrylate copolymer) is applied between 100 parts by weight of the cyclohexyl acrylate copolymer and sandwiched between the PET films subjected to the silicone release treatment. , UV irradiation from one side (1 mW / cm ^{2 for} 3 minutes, then 7 mW / cm ^{2 for} 3 minutes) to complete photopolymerization,
A pressure-sensitive adhesive sheet having a thickness of 1000 μm was formed.

Example 11
A composition containing tricresyl phosphate (50 parts by weight per 100 parts by weight of the cyclohexyl acrylate copolymer) is applied between 100 parts by weight of the cyclohexyl acrylate copolymer and sandwiched between the PET films subjected to the silicone release treatment. , UV irradiation from one side (1 mW / cm ^{2 for} 3 minutes, then 7 mW / cm ^{2 for} 3 minutes) to complete photopolymerization,
The PET film on one side was peeled off, and the sodium-treated surface of a polytetrafluoroethylene film (thickness: 130 μm) was stacked to form an adhesive sheet having a thickness of 1000 μm.

Example 12
A component polyoxyalkylene polymer, B component hydrosilyl compound (the amount of the hydrosilyl group is 1: 2 in terms of the functional group ratio to the alkenyl group amount of the component A polyoxyalkylene polymer) , C component hydrosilylation catalyst (0.04 mol relative to 1 mol of alkenyl group in component A), D component (non-halogen flame retardant) tricresyl phosphate (TCP) (A to C components) Release of a polyethylene terephthalate film release sheet from a composition containing 20 parts by weight with respect to 100 parts by weight in total) and ammonium polyphosphate (APP) (50 parts by weight per 100 parts by weight of the total amount of components A to C) It is applied to the treated surface and heat-treated at 130 ° C. for 10 minutes, and then polytetrafluoroethylene film (thickness: 130 μm) Overlapping sodium-treated surface, to form a pressure-sensitive sheet having a thickness of 1000 .mu.m.

Example 13
A composition in which rosin pentaerythritol (10 parts by weight per 100 parts by weight of the total amount of components A to C) was further added to the composition used in Example 12 was used. A pressure-sensitive adhesive sheet having a thickness of 1000 μm was formed.

Example 14
A composition in which rosin pentaerythritol (20 parts by weight per 100 parts by weight of the total amount of components A to C) was further added to the composition used in Example 12 was used. A pressure-sensitive adhesive sheet having a thickness of 1000 μm was formed.

Comparative Example 1
A component polyoxyalkylene polymer, B component hydrosilyl compound (the amount of the hydrosilyl group is 2: 5 in terms of functional group ratio relative to the alkenyl group amount of the component A polyoxyalkylene polymer) A composition comprising a hydrosilylation catalyst as component C (amount to be 1 mol with respect to 1 mol of alkenyl group in component A) and rosin pentaerythritol (25 parts by weight per 100 parts by weight of the total amount of components A to C), It is applied to the release treatment surface of the release sheet made of polyethylene terephthalate film, and the release treatment surface of the release sheet made of polyethylene terephthalate film is overlaid on the release treatment surface. A sheet was formed.

Comparative Example 2
A composition containing a urethane resin solution, a polyfunctional isocyanate, and hexacyclobromododecane (20 parts by weight per 100 parts by weight of the total amount of the urethane resin solution and the polyfunctional isocyanate component) is applied to the release treatment surface of the release sheet made of polyethylene terephthalate film. The adhesive sheet having a thickness of 1000 μm was formed by applying and heat-treating at 100 ° C. for 2 minutes.

Comparative Example 3
A composition containing a urethane resin solution, a polyfunctional isocyanate, and hexacyclobromododecane (urethane resin solution, 20 parts by weight per 100 parts by weight of the total amount of the polyfunctional isocyanate components) is a sodium of a polytetrafluoroethylene film (thickness: 130 μm). The pressure-sensitive adhesive sheet having a thickness of 1000 μm was formed by applying to the treated surface and heat-treating at 100 ° C. for 2 minutes.

Comparative Example 4
1 part of an isocyanate-based cross-linking agent (Coronate L-45 manufactured by Nippon Polyurethane Co., Ltd., solid content: 45%) and rosin pentaerythritol (butyl acrylate copolymer solution and isocyanate system) per 100 parts by weight of the butyl acrylate copolymer solution A composition containing 25 parts by weight per 100 parts by weight of the cross-linking agent is applied to a release sheet release surface made of polyethylene terephthalate film, heated at 80 ° C. for 3 minutes, and then released from polyethylene terephthalate film. The peel-treated surface of the mold sheet was stacked to form an adhesive sheet having a thickness of 1000 μm.

  The above-mentioned test was implemented with respect to each adhesive sheet produced in the above Examples 1-14 and Comparative Examples 1-4.

  As can be seen from Table 1, the gasket of the present invention has excellent flame retardancy, does not contain a halogen atom, and can suppress the corrosion of the metal even when brought into contact with the metal. To achieve a gasket. In particular, it can be seen that the gaskets of Examples 4 to 7 achieve a high-performance flame retardant gasket that does not corrode the metal in contact and exhibits extremely high flame retardancy. In addition, the gaskets of Examples 13 to 14 in which the compounding amount of the tackifying resin is 10 to 20 parts by weight can prevent foaming of the pressure-sensitive adhesive sheet, which is a manufacturing problem, while maintaining removability and flame retardancy. It was possible to obtain a gasket having an excellent appearance.

DESCRIPTION OF SYMBOLS 1 Non-halogen flame retardant containing adhesive sheet 2 Base film 3 Core film 4 Release sheet 10 Gasket 10A, 10B Adhesive surface of gasket to adherend 20,21 Adherent

Claims (12)

  A gasket mainly composed of a non-halogen flame retardant-containing pressure-sensitive adhesive sheet, wherein at least one surface is composed of the pressure-sensitive adhesive surface of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet.   The gasket according to claim 1, wherein the non-halogen flame retardant is a phosphorus flame retardant.   The gasket according to claim 1 or 2, wherein the non-halogen flame retardant-containing pressure-sensitive adhesive sheet contains a tackifying resin.   The gasket according to claim 3, wherein the tackifying resin is a terpene tackifying resin and / or a rosin tackifying resin.   The gasket according to claim 4, wherein the rosin-based tackifying resin is a rosin ester.   The gasket according to claim 4, wherein the terpene-based tackifying resin is a terpene phenol resin.   The gasket of any one of Claims 1-6 which both surfaces of the said gasket consist of an adhesive surface of a halogen-free flame retardant containing adhesive sheet.   A base film is laminated on one side of the non-halogen flame retardant-containing pressure-sensitive adhesive sheet, one side of the gasket is composed of the surface of the base film, and the other side of the gasket is a non-halogen flame retardant-containing pressure-sensitive adhesive sheet The gasket according to any one of claims 1 to 6, comprising an adhesive surface.   The gasket according to claim 8, wherein the base film is a fluororesin sheet.   The gasket according to any one of claims 1 to 9, wherein the non-halogen flame retardant-containing adhesive sheet is a polyoxyalkylene adhesive sheet containing a non-halogen flame retardant. The gasket of Claim 10 whose polyoxyalkylene type adhesive sheet containing a non-halogen flame retardant is a sheet | seat consisting of the hardened | cured material of the composition containing the following AD component.
A: Polyoxyalkylene polymer having at least one alkenyl group in one molecule B: Compound having an average of two or more hydrosilyl groups in one molecule C: Hydrosilylation catalyst D: Non-halogen flame retardant   A sealing method between two mating surfaces, wherein the gasket according to any one of claims 1 to 11 is interposed between the mating surfaces of two surfaces.

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