JPH073223A - Adhesive tape for welding and method for welding - Google Patents

Abstract

PURPOSE:To provide an adhesive tape for welding, capable of simply, highly reliably and surely welding metal members each other even by an amateur not skilled in a flame operation, etc., and a welding method using the adhesive tape. CONSTITUTION:An adhesive tape for welding comprises an adhesive agent layer containing 5-60 vol.% of a brazing metal. A method for welding comprises sticking the tape to at least one of both metal members as welding targets, sticking both the metal members to each other into a desired shape, and subsequently heating the tape to burn organic materials contained in the adhesive agent layer and simultaneously melting the brazing metal for bonding the metal members to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive tape for welding containing a metal brazing material, and more particularly to a welding adhesive tape which can easily carry out a metal brazing welding of a conventional metallic member which requires dangerous and specialized skill. The present invention relates to an adhesive tape and a welding method using the same.

[0002]

2. Description of the Related Art Welding using metal brazing is generally performed as a method for joining metal members. For example, silver brazing and gold brazing are performed in joining members made of copper or brass.

These joining methods have involved joining members together by melting, for example, a rod-shaped silver solder or gold solder using a flame at the joints of the target members.

However, in this method, since the joining portion has to be heated to a considerably high temperature, the operator who operates the flame is always in danger of burns and the like.
Further, since it is a highly skilled work to apply silver braze or gold braze uniformly to a desired thickness, it is difficult for a skilled person to reliably obtain the bonding strength. There are few skilled craftsmen who can perform such joining work, and there is also a problem that the social needs that require joining work cannot be satisfied.

Further, in the conventional brazing work, there is a problem that the molten brazing material flows even to a portion which is not desired to be brazed.

[0006]

In view of the above problems, the present invention provides an adhesive tape for welding, which enables even an unskilled person who is not skilled in flame operations and the like to easily and reliably perform reliable joining. An object is to provide a welding method using the same.

[0007]

In order to achieve the above object, the pressure-sensitive adhesive tape for welding according to the present invention comprises a pressure-sensitive adhesive and a metal braze, and has a pressure-sensitive adhesive layer containing 5 to 60% by volume of the metal braze. It is characterized by.

The photopolymerizable composition of the present invention is a composition for obtaining the above-mentioned adhesive tape for welding, which is a monomer composition containing a monomer having a polymerizable unsaturated double bond and a photopolymerization initiator. And a metal braze, and the metal braze is contained in an amount of 5 to 60% by volume.

The method of manufacturing the adhesive tape for welding according to the present invention comprises:
It is characterized in that after the photopolymerizable composition is applied to a sheet-shaped substrate, it is irradiated with ultraviolet rays.

In the welding method of the present invention, the above-mentioned adhesive tape for welding is attached to at least one of both metal members to be welded, and both metal members are brought into close contact with a desired shape,
It is characterized in that the tape is heated to burn the organic matter in the pressure-sensitive adhesive layer, and at the same time, the metal brazing material is melted to bond the metal members to each other.

Next, the present invention will be described in detail.

In the present invention, as the pressure-sensitive adhesive, a known pressure-sensitive adhesive that exhibits tackiness at room temperature or by heating is used. Examples of this include a rubber type made of natural rubber or a synthetic rubber, and an acrylic type made of an acrylic ester polymer.

As the synthetic rubber, styrene-butadiene random copolymers and block copolymers, styrene-isoprene random copolymers and block copolymers, and hydrides thereof are preferably used. Also ethylene
Vinyl acetate copolymer, amorphous polypropylene, etc. can also be used. It is preferable to blend a tackifying resin capable of imparting tackiness to these rubber components.

Examples of such adhesive resins include rosin resins, modified rosin resins, terpene resins, terpene phenol resins, aromatic modified terpene resins, C ₅ and C ₉ petroleum resins, and coumarone resins.

Of these, terpene phenol resins and modified rosin ester resins are particularly effective for improving the adhesion to adherends having a low energy surface such as olefins.

The acrylic pressure-sensitive adhesive is specifically selected from the group consisting of alkyl acrylates and methacrylic acid alkyl esters having an alkyl group having 1 to 12 carbon atoms, preferably 4 to 12 carbon atoms. A composition containing 60 to 100% by weight of at least one acrylate-based monomer and 0 to 40% by weight of a vinyl-based monomer copolymerizable with the acrylate-based monomer is prepared by a thermal polymerization method or based on a monomer composition. It can be manufactured by a so-called photopolymerization method in which the material is coated with light energy after coating.

When carrying out photopolymerization, it is necessary to add a known photoinitiator as an essential component to the composition.
Examples thereof include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone [Darocur 2959: manufactured by Ciba Geigy], α-hydroxy-
α, α-Dimethyl-acetophenone [Darocur 117
3: manufactured by Ciba-Geigy], methoxyacetophenone,
Acetophenone series such as 2,2-dimethoxy-2-phenylacetophenone; Benzoin ether series such as benzoin dimethyl ether, benzoin ethyl ether and benzoin isopropyl ether; Ketal series such as benzyl dimethyl ketal; Others, halogenated ketones,
Acyl phosphinoxide, acyl phosphonate, etc. can be mentioned.

When a welding tape is produced by the photopolymerization method, an acrylate monomer having an alkyl group is further compounded with a so-called epoxy acrylate or urethane acrylate having epoxy or urethane in the main chain skeleton of the polymer, Although it can be developed without a separator in the tape winding shape, a so-called self-adhesive pressure-sensitive adhesive tape having sufficient adhesiveness to its back surface when wound on an adherend can be produced.

The self-adhesive pressure-sensitive adhesive tape without such a separator is more efficient because the work of attaching the welding tape does not require the work of separating the separator.

In the case of an acrylic adhesive, it is preferable to add a crosslinking agent. Since the polymer is cross-linked by the incorporation of the cross-linking agent, the adhesive layer of the adhesive tape for welding does not sag from the adherend when the tape burns.

When the pressure-sensitive adhesive is a solution type, the cross-linking agent preferably has a plurality of functional groups reactive with the cross-linkable functional group in the polymer such as diisocyanates, diepoxys and diimines. Used.

When the pressure sensitive adhesive is produced by photopolymerization, a polyfunctional vinyl compound may be contained in the monomer composition as a crosslinking agent. Such compounds include:
Examples thereof include hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, and trimethylolpropane tri (meth) acrylate.

Further, in the present invention, a tackifying resin,
You may mix | blend normally used additives, such as a thickener, a thixotropic agent, a bulking agent, and a filler.

The thickness of the polymer layer is 5 to 150.
It is preferably about μm.

In the present invention, the metal braze is uniformly dispersed in the pressure-sensitive adhesive layer. The metal wax is preferably granular. The particle size is preferably 1 to 200 μm from the viewpoint of miscibility with the pressure-sensitive adhesive and coatability of the composite with the pressure-sensitive adhesive.

Examples of the metal solder used in the present invention include silver solder, gold solder, aluminum alloy solder, brass solder, phosphor copper solder, nickel solder, special nickel solder, palladium solder and various solders. The type of the metal brazing material is appropriately selected depending on the type and properties of the metal member to be welded.

In the present invention, the adhesive contains 5 to 60% by volume of a metal wax. If the metal brazing is less than 5% by volume, the amount of tape for securing the metal brazing necessary for welding becomes large and the practicality is lowered. On the other hand, if the metal brazing exceeds 60% by volume, the tackiness becomes poor. Is lost. Moreover, the content of the preferable metal brazing is 10 to 30.
% By volume.

The thickness of the obtained pressure-sensitive adhesive layer is generally 50 to
It is about 500 μm and is appropriately selected according to the application.

[0029]

In the pressure-sensitive adhesive tape for welding according to the present invention, since the metal brazing material is uniformly dispersed in the pressure-sensitive adhesive layer, after the tape is attached to the metal member to be welded, the tape is heated to
By burning the organic matter in the pressure-sensitive adhesive layer and melting the metal braze, a brazing material layer having a uniform film thickness is provided, and the joining target members can be strongly joined.

Further, according to the welding method of the present invention, the work of attaching the adhesive tape for welding to the members to be joined can be easily carried out before heating, and in the subsequent burning step, the worker approaches the welded part. Since it is not necessary, joining can be performed very safely.

[0031]

EXAMPLES Next, the present invention will be specifically described by way of examples, but the present invention is not limited to these.

[Example 1] 1) Production of acrylic copolymer In a reactor equipped with a cooling pipe, 60 parts by weight of 2-ethylhexyl acrylate, 38 parts by weight of butyl acrylate and 2 parts by weight of acrylic acid were added to 80 parts by weight of ethyl acetate. The mixture was charged with 100 parts by weight of the mixture, the temperature was raised, and the mixture was kept at the reflux temperature for 30 minutes.
A solution dissolved in 0 part by weight was added dropwise and reacted for 7 hours.

After this, a solution of 0.1 part by weight of benzoyl peroxide in 10 parts by weight of ethyl acetate was further added dropwise to the reaction solution, and the reaction was carried out for 4 hours.

Then, 22 parts by weight of toluene was added thereto and cooled to obtain an acrylic copolymer solution.

This acrylic copolymer solution has a solid content of 4
The viscosity was 4.8% and the viscosity was 14,000 cps (20 ° C.).

2) Production of pressure-sensitive adhesive composition 100 parts by weight of an acrylic copolymer solution and 10 parts by weight of average particle size
40 parts by weight (7.8% by volume) of 0 μm silver brazing powder was mixed, and 0.5 parts by weight of tolylene diisocyanate was further added to obtain a pressure-sensitive adhesive composition.

3) Production of Adhesive Tape for Welding This adhesive composition was coated with a peelable surface having a thickness of 38 μm.
m polyethylene terephthalate film
It was dried at 80 ° C. for 5 minutes and cured. The formed pressure-sensitive adhesive layer had a thickness of 150 μm.

A silver brazing layer was formed on the surface layer and was slightly tacky, but the adhesive surface to the release film had sufficient tackiness.

The 180 ° peeling force of the adhesive surface of the release film to the stainless steel plate was measured and found to be 700 gf per 25 mm width.

Example 2 1) Production of Photopolymerizable Composition 70 parts by weight of 2-ethylhexyl acrylate, 30 parts by weight of carboxyethyl acrylate, Irgacure 651
(Ciba Geigy, trade name) 0.2 parts by weight, hexanediol diacrylate 0.2 parts by weight, and acrylic rubber (Toa Paint Co., trade name PS250) 2.5 parts by weight were mixed and stirred.

The viscosity of this composition measured by a Brookfield viscometer was 1000 cps.

Further, 100 parts by weight (9.1% by volume) of silver wax powder having an average particle size of 100 μm was added to this composition and mixed by stirring to obtain a photopolymerizable composition.

2) Production of Adhesive Tape for Welding This photopolymerizable composition was applied to a polyethylene terephthalate film having a releasable surface in a thickness of 0.3 mm.

The coating layer was covered with another polyethylene terephthalate film having a peelable surface.

Light irradiation was performed through this cover film using an ultrahigh pressure mercury lamp. Light intensity of the irradiation surface is 3m
W / cm ² and irradiation time was 5 minutes. Further, this partially cured film was turned upside down, and light irradiation was performed again under the same conditions.

The obtained tape had double-sided adhesiveness, and its 180 ° peeling force to the stainless steel plate was 900 gf per 25 mm width.

[Example 3] 100 parts by weight of styrene-isoprene-styrene block copolymer (manufactured by Nippon Zeon Co., Quintac 3435), 30 parts by weight of tackifying resin (manufactured by Nippon Zeon Co., Quinton U-185), average particle size 1
200 parts by weight of silver powder of 00 μm (13.3% by volume)
Were mixed and stirred in a 160 ° C. bath.

This was applied to a crepe paper having a peeling interface so as to have a thickness of 300 μm by a hot melt applicator (LH2 manufactured by Accumeter Co., Ltd.).

180 with respect to the stainless plate on the side of the release paper
Degree peeling force was measured, 700g per 25mm width
It was f.

[Example 4 (Welding)] The adhesive tape for welding obtained in Example 1 was wound so as to overlap a joint portion of two cylindrical copper tubes having a tube diameter of 20 cm. The tape section was then burned for 5 minutes with a burner.

The organic compound portion of each tape was incinerated,
The silver solder melted and the pipe ends could be welded. The brazing filler metal layer in the welded portion had a uniform film thickness, and the copper pipes were firmly joined together.

Further, the welding adhesive tapes obtained in Examples 2 and 3 were also subjected to the same weldability test as above. As a result, good results equivalent to those of the tape of Example 1 were obtained. .

[0053]

According to the welding tape and the welding method of the present invention, the brazing work which has been possible only by the skilled person can be performed.
It can be performed safely and easily even by an amateur.

Further, according to the present invention, since only the portion to which the welding tape having an arbitrary shape is attached can be welded, only the desired welded portion can be welded even if the welded portion is extremely small.

Further, since the welding tape can be attached by a known automatic attaching machine, the brazing work can be automated by combining this with the combustion line.

Claims (4)

[Claims] 1. A pressure-sensitive adhesive tape for welding, comprising a pressure-sensitive adhesive and a metal braze, and having a pressure-sensitive adhesive layer containing 5 to 60% by volume of the metal braze. 2. A photopolymerizable composition comprising a monomer composition containing a monomer having a polymerizable unsaturated double bond and a photopolymerization initiator, and a metal wax, and containing 5 to 60% by volume of the metal wax. 3. A method for producing a pressure-sensitive adhesive tape for welding, which comprises applying the photopolymerizable composition according to claim 2 to a sheet-shaped substrate and then irradiating it with ultraviolet rays. 4. The adhesive tape for welding according to claim 1 is affixed to at least one of both metal members to be welded, the both metal members are brought into close contact with a desired shape, and then the tape is heated to give an adhesive. A welding method, characterized in that an organic substance in a layer is burned, a brazing metal is melted, and metallic members are joined to each other.