JP2002317169A - Bonding method of photoreactive hot melt adhesive - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To be applied by heat melting coating or applied as an adhesive sheet, and quickly cured by light irradiation,
In addition, even when at least one of the adherends is an adherend having a cationic polymerization reaction inhibiting property, a photoreaction capable of obtaining a bonded body exhibiting excellent normal adhesive strength and excellent heat resistant adhesive strength after curing. Provided is a method for bonding a hot melt adhesive. SOLUTION: This is a method for bonding a photoreactive hot-melt adhesive containing a cationically polymerizable compound and a cationic photopolymerization initiator, wherein an adherend (A) having a cationic polymerization reaction inhibitory property is cationically polymerized. In bonding the adherend (B) having no reaction inhibition property, the above-mentioned hot melt type adhesive is heated and melt-coated on the above-mentioned adherend (B), and then applied to the surface of the hot melt type adhesive. A method of bonding a photoreactive hot-melt adhesive in which the above-mentioned adherend (A) is attached to a light-irradiated surface after light irradiation, and an adherend (A) having a cationic polymerization reaction inhibiting property is an IC card The method for bonding the photoreactive hot-melt adhesive as an inlet film constituting the above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for bonding a photo-reactive hot-melt adhesive which is applied by heat-melt coating or applied as an adhesive sheet and is cured by irradiation with light.

[0002]

2. Description of the Related Art A hot-melt type adhesive has an advantage that it exhibits a high adhesive force and is advantageous in terms of safety and hygiene because it is a solventless type. , Light electricity, transportation and other fields,
It is widely used for bonding various adherends such as paper, fiber, wood, plastic, metal and glass.

[0003] The hot-melt type adhesive is usually used in an applicator for hot-melt for 100 to 100 hours.
It is heated and melted at a temperature of about 200 ° C., and is applied to the adherend in a molten state. The melt-coated hot melt adhesive adheres to the adherend by cooling and solidifying. Such a hot-melt type adhesive has the advantage that the time from bonding the adherends to the development of the bonding strength is very fast, usually within 1 minute, and the bonding operation can be performed in a very short time. Having.

[0004] However, hot-melt type adhesives have a problem that they need to be melted by heating and are therefore composed of a thermoplastic component, and generally have insufficient heat resistance. Therefore, when applying or laminating hot melt type adhesive, by introducing a curing system by some kind of chemical reaction,
Studies for improving heat resistance have been widely conducted.

As a hot-melt type adhesive into which the above-mentioned curing system has been introduced, for example, JP-A-49-98445 discloses a derivative of urethane prepolymer, ethylene-vinyl acetate copolymer and abietic acid type rosin, terpene-phenol. A moisture-reactive (moisture-curable) hot-melt adhesive made of a copolymer resin is disclosed.

However, the moisture-reactive hot-melt type adhesive disclosed in the above-mentioned publication has a curing reaction that proceeds due to moisture (humidity) in the air or in an adherend, and therefore generally has a slow curing reaction. In particular, when the adherend is made of a moisture-impermeable material, the curing becomes insufficient or the curing takes a very long time, and the moisture-curing reaction proceeds at room temperature, so that the storage stability is low. There is a problem that it is inhibited, or that it contains an isocyanate-based compound (urethane prepolymer), which adversely affects the working environment.

On the other hand, as a curing system instead of a moisture reaction (moisture curing), curing of a cationically polymerizable compound such as an epoxy compound by using a photo-cationic polymerization initiator capable of decomposing by light to generate a Lewis acid. For example, Japanese Patent Application Laid-Open No. H6-306
No. 346, a total of 100 parts by weight of about 2 to 95 parts by weight of an epoxy compound and about 98 to 5 parts by weight of a polyester compound, and an effective amount of a cationic photopolymerization initiator for radiation curing of a hot melt composition. And a room temperature solid hot melt composition comprising a hydroxyl group-containing compound having at least one hydroxyl value and capable of melting into a liquid when heated.

[0008] The hot melt composition disclosed in the above-mentioned publication increases the adhesive strength (initial adhesive strength) immediately after laminating by blending a polyester compound which is solid at room temperature, so that the curing is completed. No temporary fixing jigs such as clamps or temporary fixing work are required.

However, the above hot melt composition initiates cationic polymerization by a Lewis acid generated by a cationic photopolymerization initiator, but the adherend is composed of, for example, a nitrogen atom or a phosphorus atom. In the case of an adherend comprising a resin containing a large number of functional groups that can be a Lewis base having, that is, in the case of an adherend having a cationic polymerization reaction inhibiting property, the catalytic action of Lewis acid is inhibited by the Lewis base. However, the hot melt composition at the adherend interface is not sufficiently cured, and the adhesive strength, especially when exposed to a high-temperature atmosphere, becomes insufficient. is there.

In recent years, in the production of IC cards, photoreactive hot-melt adhesives do not require moisture unlike moisture-curable hot-melt adhesives, and cure quickly.
It has been drawing attention as a reactive hot-melt adhesive that exhibits excellent properties after curing.

However, in the production of IC cards,
In many cases, the inlet film constituting the C card is formed of a resin containing a large number of nitrogen atoms, such as a polyimide resin.
Generally, an adhesive layer mainly composed of a resin containing a large number of nitrogen atoms, such as a polyurethane resin, is formed on an inlet film to bond a C chip, an antenna, or the like. Since an adherend having a cationic polymerization reaction inhibitory property is often used, an IC is formed by a normal bonding method using a photoreactive hot-melt adhesive.
When a card is manufactured, if the IC card is exposed to a high temperature, for example, if the IC card is left in a car parked outdoors, or if it is accidentally washed with clothes and put into a dryer, the cations of the adherend may be reduced. Insufficient heat resistant adhesive strength due to the effect of polymerization reaction inhibition, inlet film and IC
The same problem as described above occurs in that the adhesive interface between the chip and the antenna or the like easily shifts.

[0012]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to apply the composition by heating and melting or to apply it as an adhesive sheet, which cures quickly by irradiation with light, and Even when at least one of the bodies is an adherend having a cationic polymerization reaction inhibiting property, a photoreactive hot melt adhesive capable of obtaining a bonded body exhibiting excellent adhesive strength and excellent heat resistance after curing. To provide a bonding method.

[0013]

According to the first aspect of the present invention, there is provided a method for bonding a photoreactive hot-melt adhesive comprising a cationically polymerizable compound having an average of at least one cationically polymerizable reactive group per molecule and a photopolymerizable compound. A method for bonding a photoreactive hot-melt adhesive containing a cationic polymerization initiator, comprising: an adherend (A) having a cationic polymerization reaction inhibitory property and an adherend (A) having no cationic polymerization reaction inhibiting property ( In bonding with (B), the hot-melt adhesive is heated and melt-coated on the adherend (B), and then the surface of the hot-melt adhesive is irradiated with light. It is characterized in that the adherend (A) is bonded.

According to a second aspect of the present invention, there is provided a method for bonding a photoreactive hot-melt adhesive comprising a cationically polymerizable compound having an average of at least one cationically polymerizable reactive group per molecule and a cationic photopolymerization initiator. A method for adhering a photoreactive hot-melt type adhesive, comprising the steps of: subjecting adherends (A) having a cation polymerization reaction inhibitory property to each other or a cation polymerization reaction with an adherend (A) having a cation polymerization reaction inhibitory property; In bonding the non-inhibiting adherend (B), a photoreactive hot-melt adhesive sheet made of the above-mentioned photoreactive hot-melt type adhesive is prepared in advance, and on one or both sides of the hot-melt adhesive sheet After irradiating the light, the adherend (A) is attached to the light irradiation surface.

According to a third aspect of the present invention, there is provided the method for bonding a photoreactive hot melt adhesive according to the first or second aspect. The hot-melt adhesive is characterized by further containing a thermoplastic resin.

The method for bonding a photoreactive hot-melt adhesive according to claim 4 is the same as the method for bonding a photoreactive hot-melt adhesive according to any one of claims 1 to 3 above. The adherend (A) having a cationic polymerization reaction inhibiting property is an inlet film constituting an IC card.

The photoreactive hot melt adhesive used in the present invention is a cationically polymerizable compound having an average of at least one cationically polymerizable reactive group per molecule (hereinafter simply referred to as “cationically polymerizable compound”). And a cationic photopolymerization initiator.

The cationically polymerizable reactive group is not particularly limited, but may be, for example, a compound represented by the following general formula (1):
And a cationically polymerizable reactive group represented by

Embedded image (Wherein R ₁ , R ₂ , R ₃ and R ₄ represent a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, an isoamyl group or a phenyl group, and R ₅ , R ₆ and R ₇ represent a hydrogen atom or Represents an organic group, and m and n represent 0, 1 or 2)

The cationically polymerizable compound contained in the photoreactive hot-melt adhesive used in the present invention includes, for example, a cationically polymerizable reactive group represented by the above general formula (1) in a molecular skeleton or in a molecule. It may be present at the end of the skeleton or as a side chain. Further, the cationically polymerizable compound may contain a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, or the like as a constituent atom.

The structure, molecular weight, properties and the like of the cationic polymerizable compound are not particularly limited, and may be any of a monomer, an oligomer, a polymer and the like. The cationically polymerizable compound is solid at room temperature, and may be a hot-melt resin itself, or may be a semi-solid or liquid at room temperature.

The cationically polymerizable compound is not particularly limited, but examples thereof include cyclic ether compounds such as epoxy compounds, oxetane compounds, and oxolane compounds. Epoxy compounds are preferably used because of their excellent polymerizability. Further, these cationically polymerizable compounds may be used alone or in combination of two or more.

The epoxy compound is an organic compound having at least one oxirane ring polymerizable by cationic polymerization, and may be any of a monomer, an oligomer, and a polymer. formula,
Any of aromatic compounds may be used. The epoxy compound may contain a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, or the like as a constituent atom, and the structure is not particularly limited, but is preferably Is a compound having an average number of epoxy groups of 2 or more per molecule. Here, the average number of epoxy groups per molecule is determined by dividing the number of epoxy groups in the epoxy compound by the total number of existing epoxy molecules.

The above-mentioned polymeric epoxy compound includes:
For example, a linear polymer having an epoxy group at a terminal such as a diglycidyl ether of a polyoxyalkylene glycol; a polymer having an oxirane unit in a skeleton such as a polybutadiene polyepoxide; and an epoxy in a side chain such as a glycidyl (meth) acrylate polymer or copolymer. Polymers having a group are included.

Specific examples of such an epoxy compound are not particularly limited. For example, bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, etc. Aromatic epoxy resin; trimethylolpropane triglycidyl ether and 2,2-
Aliphatic epoxy resin such as bis [4- (2,3-epoxypropoxy) cyclohexyl] propane; polymer or copolymer of (meth) acrylate having an oxirane ring in a molecule such as glycidyl (meth) acrylate; epoxidation Epoxidized products of polybutadiene and copolymers of butadiene and other monomers; and modified products of these various epoxy compounds. These epoxy compounds may be used alone or in combination of two or more. Further, the molecular weight of the epoxy compound is not particularly limited, and may be 58 to 100,000 or more.

The cationic photopolymerization initiator contained in the photoreactive hot melt adhesive used in the present invention includes:
Irradiation of light may be any as long as it can generate a cation for initiating polymerization of the cationically polymerizable compound,
Although not particularly limited, for example, an ionic photoacid generating type photocationic polymerization initiator may be mentioned. These cationic photopolymerization initiators may be used alone,
Two or more types may be used in combination.

The ionic photoacid generating type cationic photopolymerization initiator is not particularly restricted but includes, for example, aromatic iodonium salts, aromatic sulfonium salts, aromatic diazonium salts, aromatic halonium salts and the like. Organic metal complexes such as onium salts, metallocene salts, arylsilanol / aluminum complexes, iron / allene complexes, titanocene complexes, and the like. These ionic photoacid generating type photocationic polymerization initiators may be used alone or in combination of two or more.

Specific examples of these cationic photopolymerization initiators include:
For example, aromatic iodonium salts and aromatic sulfonium salts are disclosed in U.S. Pat. No. 4,256,828, and metallocene salts are disclosed in U.S. Pat.
No. 089536.

By including a photo-cationic polymerization initiator in the photo-reactive hot-melt adhesive, for example, the wavelength 2
By irradiating light including light of 00 to 600 nm,
The curing of the photoreactive hot-melt adhesive can proceed promptly. In addition, if light is blocked, no curing reaction occurs, so that storage stability is also excellent.

The amount of the cationic photopolymerization initiator in the photoreactive hot-melt adhesive depends on the type and intensity of light, the type and amount of the cationically polymerizable compound, and the type of the cationic photopolymerization initiator. It is not particularly limited as long as it is appropriately set, but generally, it is preferably 0.01 to 10 parts by weight of the cationic photopolymerization initiator based on 100 parts by weight of the cationically polymerizable compound.

If the amount of the cationic photopolymerization initiator is less than 0.01 part by weight per 100 parts by weight of the cationically polymerizable compound, the photopolymerization reaction of the cationically polymerizable compound may not proceed smoothly, and Polymerizable compound 10
When the blending amount of the cationic photopolymerization initiator is 0
If the amount is more than 10 parts by weight, the physical properties of the cured product of the photoreactive hot-melt adhesive may be rather deteriorated.

The photoreactive hot-melt adhesive used in the present invention further comprises a thermoplastic resin (including a thermoplastic elastomer) in addition to the cationic polymerizable compound and the photocationic polymerization initiator which are essential components. Preferably, it is contained.

The thermoplastic resin may be any resin that can be melted by heating and solidified by cooling, and is not particularly limited. Examples thereof include polyolefin resins such as polyethylene and polypropylene, polybutadiene, and the like.
Elastomers such as polychloroprene, polyisoprene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polyether resins such as polyethylene oxide, polypropylene oxide, polytetramethylene oxide, polyvinyl acetate, ethylene-vinyl acetate copolymer Coal, polyvinyl chloride, ethylene-vinyl chloride copolymer, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl resin such as polyvinyl formal, polyvinyl butyral, polyvinyl ether, and (meth) acrylate ester Polyacrylic resin such as polymer, polystyrene resin, polyester resin, polycarbonate resin, ketone resin, acrylonitrile-styrene copolymer resin, acrylonitrile -Butadiene-styrene copolymer resin, etc., among which, among them, because the adhesiveness of the cured product of the photoreactive hot-melt adhesive becomes excellent, polyvinyl resin, polyacrylic resin, polyester A resin, a polycarbonate resin and the like are preferably used. These thermoplastic resins may be used alone or in combination of two or more.

The mixing ratio of the thermoplastic resin to the cationically polymerizable compound is not particularly limited, but the thermoplastic resin / cationically polymerizable compound is 5/95 to 5% by weight.
It is preferably 95/5, more preferably 10 /
90-80 / 20.

When the ratio of the thermoplastic resin / cationic polymerizable compound (weight ratio) is less than 5/95, the effect obtained by blending the thermoplastic resin may not be sufficiently obtained. Polymerizable compound (weight ratio) is 95
When the ratio exceeds / 5, the photoreactivity (photocurability) of the obtained photoreactive hot melt adhesive may be insufficient.

The photoreactive hot-melt type adhesive used in the present invention may have, if necessary, an adhesion improving agent such as a silane coupling agent or a titanium coupling agent as long as the object of the present invention is not hindered. Agents, benzophenone and 9,10
-Photosensitizers such as anthraquinone, curing accelerators, curing retarders, dehydrating agents, antioxidants (antiaging agents), heat stabilizers, softeners, plasticizers, waxes, fillers, flame retardants, foaming agents, One or more of various additives such as an antistatic agent, a fungicide, a viscosity modifier, and a coloring agent may be blended.

One or more of the above additives may be previously blended with each of the above-mentioned components such as the cationically polymerizable compound, the photo-cationic polymerization initiator and the thermoplastic resin. It may be blended after preparing a composition comprising the components.

The method for producing the photoreactive hot-melt adhesive used in the present invention is not particularly limited.
Any kneading equipment or kneading method may be adopted as long as the components to be blended can be uniformly kneaded, but it is preferable to produce the components under appropriate heating conditions under which the components can be melted. In addition, kneading of each component during production may be performed without a solvent,
After kneading in an inert solvent, the solvent may be removed. Specific kneading equipment is not particularly limited, for example, double helical ribbon bath, gate bath, butterfly mixer, planetary mixer, three rolls, kneader-ruder type kneader, extruder-type kneading extruder, etc. But are not limited to these. Further, as these kneading equipment and kneading method, a single equipment or a single method may be used, or two or more kinds of equipment or two or more kinds of methods may be used in combination.

The production of the photoreactive hot-melt adhesive is preferably carried out under anhydrous conditions in order to reduce the incorporation of water, which is a component that inhibits the cationic polymerization reaction of the cationically polymerizable compound. Further, the above production may be performed under atmospheric pressure, or may be performed under reduced pressure or under increased pressure as needed. Further, the above-mentioned production is preferably performed in a state in which light including light having a wavelength effective for initiating curing by the cationic polymerization reaction is substantially blocked. The heating temperature range during the production is not particularly limited, but is 50 to
The temperature is preferably 250 ° C, more preferably 80 to 200 ° C.

The thus obtained photoreactive hot-melt adhesive is preferably solid at room temperature, may have tackiness (tack) at room temperature, or may be non-tacky at room temperature. There may be.

The photoreactive hot-melt adhesive used in the present invention undergoes a cationic polymerization reaction upon irradiation with light. Therefore, upon storage, light containing light having a wavelength effective for starting curing by the cationic polymerization reaction is used. It is preferable to use a storage container that can be substantially shut off. Preferred storage containers include, for example, pail, tin can, drum, cartridge, release box, release tray, cardboard case, paper bag,
Examples of the opaque container and the material of the container, such as a plastic container, which do not transmit light, include, but are not limited to, these containers and the material of the container. Further, the photoreactive hot-melt adhesive does not employ these storage methods,
It may be used immediately after production.

In the method for adhering the photoreactive hot-melt adhesive according to the present invention (hereinafter simply referred to as "adhesion method"), the adherend (A) having a cation polymerization reaction inhibiting property and the cation polymerization reaction inhibiting In bonding the adherend (B) having no property, a photoreactive hot-melt adhesive is applied to the adherend (B) by heating and melting, and then the surface of the hot-melt adhesive is After irradiation with light, it is necessary to attach the adherend (A) to the light irradiation surface.

The adherend (A) having a cationic polymerization reaction-inhibiting property referred to in the present invention refers to an adherend composed of a resin containing a large number of functional groups which can be a Lewis base composed of a nitrogen atom or a phosphorus atom. means.

Specific examples of the adherend (A) having the cationic polymerization reaction-inhibiting property are not particularly limited. For example, polyimide-based resin, polyurethane-based resin, acrylonitrile-butadiene-styrene copolymer Resins.

The photoreactive hot-melt type adhesive used in the present invention is characterized in that the photocationic polymerization initiator contained in the adhesive generates Lewis acid upon irradiation with light,
The cationic polymerization reaction of the cationically polymerizable compound contained in the adhesive is started. When at least one of the adherends is the adherend (A) having the above-described cationic polymerization reaction inhibitory property, the cationic photopolymerization is performed. The catalytic action of the Lewis acid generated from the initiator is inhibited by coming into contact with the Lewis base contained in the adherend (A) having a cationic polymerization reaction inhibiting property, and the light located near the interface of the adherend (A) is inhibited. There is a problem that the reactive hot-melt adhesive is not sufficiently cured, and the bonding strength and heat resistance of the obtained joined body are insufficient.

However, in the bonding method of the present invention, when the adherend (A) having no cationic polymerization reaction inhibiting property and the adherend (B) having no cationic polymerization reaction inhibiting property are adhered, first, the cationic polymerizing reaction is inhibited. A photoreactive hot-melt adhesive is heated and melt-coated on the adherend (B) having no reaction inhibition property, and then the surface of the hot-melt adhesive is irradiated with light to be contained in the adhesive. After the cationic polymerization reaction of the cationically polymerizable compound is excited and started, an adhesion method is employed in which an adherend (A) having a cationic polymerization reaction inhibiting property is attached to the light irradiation surface. In the bonding method, since the cationically polymerizable compound in the photoreactive hot-melt adhesive has already started the cationic polymerization reaction, the cationic polymerization by contact with the Lewis base contained in the adherend (A) is performed. Hardly affected by reaction inhibition. In addition, since the cationically polymerizable compound at the time of being bonded to the adherend (A) has not yet terminated the cationic polymerization reaction,
It can also react to some extent with the interface of the adherend (A). Therefore,
According to the bonding method of the present invention, even when one of the adherends is the adherend (A) having a cationic polymerization reaction inhibitory property, a bonded body that exhibits excellent adhesive strength and excellent heat resistance is obtained. be able to.

In the above bonding method, the adherend (B)
Is transparent and light-transmitting, the surface of the photoreactive hot-melt adhesive is directly irradiated with light, and is irradiated indirectly through the adherend (B). May be.

The method of heat-melting and coating the photoreactive hot-melt type adhesive on the adherend (B) having no cationic polymerization reaction inhibiting property is not particularly limited. A method in which a photoreactive hot-melt adhesive that has been heated and melted by a melt applicator or a hot-melt coater is applied to the bonding surface of the adherend (B). A method of immersing (dipping) the bonding surface of the body (B), a method of spraying (spraying) a photoreactive hot-melt type adhesive which is heated and melted by a hot melt air gun or the like to the bonding surface of the adherend (B), A method of extruding and coating a photoreactive hot-melt type adhesive which has been heated and melted by a machine or the like onto the joining surface of the adherend (B), but is not limited to these coating methods. Not.

In the above coating, the photoreactive hot-melt adhesive may be supplied to a hot-melt applicator or a hot-melt coater using a pail unloader or a cartridge dispenser, or may be in the form of a stick or pellet. The shape, slug, block, pillow, billet, etc. may be supplied to the above-mentioned various coating apparatuses. Further, upon the heating and melting, the entire photoreactive hot melt adhesive may be heated and melted,
Only the photoreactive hot melt adhesive located near the heating device may be heated and melted. In any of the above-mentioned heat-melt coating methods, it is preferable to perform the method in a state where light including light having a wavelength effective for initiating curing of the photoreactive hot-melt adhesive by the cationic polymerization reaction is blocked.

In the bonding method of the present invention, the adherends (A) having a cationic polymerization reaction inhibiting property or the adherends having a cationic polymerization reaction inhibiting property (A) and the adherend having no cationic polymerization reaction inhibiting property are used. When bonding with (B), a photoreactive hot-melt adhesive sheet made of the photoreactive hot-melt adhesive is prepared in advance, and one or both surfaces of the hot-melt adhesive sheet are irradiated with light. A method of attaching the adherend (A) to the light irradiation surface may be adopted.

That is, when the adherends (A) having a cationic polymerization reaction inhibitory property are bonded to each other, light is applied to both surfaces of the photoreactive hot melt adhesive sheet, and then the adherence is applied to both light-irradiated surfaces. The bodies (A) may be attached to each other. or,
When the adherend (A) having a cationic polymerization reaction inhibiting property and the adherend (B) having no cationic polymerization reaction inhibiting property are bonded, light is applied to one surface of the photoreactive hot melt adhesive sheet. After the irradiation, the adherend (A) is bonded to the light irradiation surface, and the adherend (B) is bonded to the other surface of the photoreactive hot melt adhesive sheet, or the photoreactive hot melt is bonded. After irradiating both surfaces of the adhesive sheet with light, the adherend (A) may be attached to one light irradiation surface and the adherend (B) may be attached to the other light irradiation surface.

By employing such an adhesion method, even when one or both of the adherends are the adherends (A) having a cationic polymerization reaction inhibiting property, a sheet-form photoreactive hot melt type adhesive can be used. The agent is hardly affected by the above-mentioned cation polymerization reaction inhibiting action due to contact with the Lewis base contained in the adherend (A).
Since the cationically polymerizable compound contained in the hot-melt adhesive formed into a sheet at the time when it is bonded to the substrate has not yet terminated the cationic polymerization reaction, it may react to some extent with the interface of the adherend (A). Is possible,
It is possible to obtain a joined body that exhibits excellent normal adhesive strength and excellent heat resistant adhesive strength.

The method for producing the photoreactive hot melt adhesive sheet from the photoreactive hot melt adhesive is not particularly limited, and may be, for example, a roll coater, a flow coater, a bar coater, an extruder, or the like. The desired photoreactive hot melt adhesive sheet can be obtained by applying or extruding the hot-melt adhesive which has been heated and melted onto a release-treated surface of a release material such as a release paper or a release film. it can.

The light used for exciting and initiating the cationic polymerization reaction of the photoreactive hot-melt adhesive used in the present invention may be any light as long as it can generate cations from the photocationic polymerization initiator. Of light can be used. The type of light may be appropriately selected according to the type of the cationic photopolymerization initiator.
It is preferable to use light including light having a wavelength of 0 to 600 nm. In particular, onium salts such as aromatic iodonium salts and aromatic sulfonium salts as a cationic photopolymerization initiator,
When a metallocene salt or the like is used, 200 to 400
It is preferable to use light including light having a wavelength of nm.

Although the amount of light irradiation varies depending on the type of the cationic photopolymerization initiator and the coating thickness and the coating amount of the photoreactive hot-melt adhesive, it is difficult to determine the amount of light, but it is generally difficult to determine. , 0.001 to 10 J. The photoreactive hot-melt adhesive used in the present invention cures even with a relatively low irradiation amount of light.
If it is about 00 μm, it is sufficiently cured with a light irradiation amount of 60 mJ or more. The light irradiation source is not particularly limited when, for example, ultraviolet light is used as the light, and examples thereof include a fluorescent lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a chemical lamp, and a xenon lamp. These irradiation sources may be used alone or in combination of two or more.

The photoreactive hot-melt type adhesive used in the present invention can be sufficiently cured by irradiating light. However, if it is desired to further shorten the curing time, an appropriate heating may be carried out during or after light irradiation. May be performed. As a heating method in this case, an appropriate method may be appropriately adopted depending on the type of the photoreactive hot melt adhesive, the shape and properties of the adherend, the heating conditions, and the like, for example, blowing hot air or hot air. Examples thereof include a method, a method of placing in a heated oven, and a method of heating with a heater, but are not limited to these heating methods. These heating methods may be used alone or in combination of two or more.

The bonding method of the present invention is suitably applied when at least one of the adherends constituting the bonded body is the adherend (A) having a cationic polymerization reaction inhibiting property. It is particularly preferably applied when the body (A) is an inlet film constituting an IC card.

In the manufacture of an IC card, the inlet film constituting the IC card is often formed of a resin containing a large number of nitrogen atoms, such as a polyimide resin. In general, an adhesive layer mainly composed of a resin containing a large number of nitrogen atoms, such as a polyurethane resin, is formed on an inlet film in order to adhere the resin to the cation polymerization reaction. When an IC card is manufactured by a normal bonding method using a photoreactive hot-melt adhesive, the IC card is exposed to a high temperature.
Since the heat-resistant adhesive strength is insufficient under the influence of the cationic polymerization reaction inhibitory property of the adherend (A), the adhesive interface between the inlet film and the IC chip, the antenna, or the like is likely to shift.

However, by applying the bonding method of the present invention, the photo-reactive hot-melt type adhesive has an effect of inhibiting the cationic polymerization reaction of the inlet film itself or the adhesive layer formed on the inlet film. Almost no reception occurs, and the interface can react to some extent with the interface of the inlet film itself and the adhesive layer formed on the inlet film, so that an IC card exhibiting excellent adhesive strength and excellent heat resistance can be manufactured. .

[0059]

The bonding method of the present invention comprises the steps of: first applying a hot-melt adhesive to the surface of a hot-melt adhesive coated by heating and melting; After irradiating light to excite and start the cationic polymerization reaction of the cationically polymerizable compound contained in the photoreactive hot melt adhesive, the adherend having a cationic polymerization reaction inhibiting property on the light irradiation surface Since the method of laminating (A) is employed, the cationically polymerizable compound has already started the cationic polymerization reaction, and the adherend (A)
Is almost unaffected by the cationic polymerization reaction inhibitory action due to contact with the Lewis base contained in In addition, since the cationically polymerizable compound at the time of being bonded to the adherend (A) has not yet terminated the cationic polymerization reaction, it may react to some extent with the interface of the adherend (A). Therefore, according to the bonding method of the present invention, even when at least one of the adherends is the adherend (A) having a cationic polymerization reaction-inhibiting property, a conjugate exhibiting excellent adhesive strength and excellent heat resistance is provided. Can be obtained.

[0060]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” means “parts by weight”.

Example 1 70 parts of a polyester resin (trade name "UE3400", manufactured by Unitika) and a bisphenol A type epoxy resin (trade name "Epicoat 100")
1 ", manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts were put into a planetary mixer equipped with a jacket capable of circulating heating oil, and the surface was covered with aluminum foil. The mixture was stirred and kneaded. Then, while continuing stirring, the temperature of the content was lowered to 130 ° C., and an aromatic sulfonium salt (trade name “Siracure UVI-699”) was used as a photocationic polymerization initiator.
0 ", manufactured by Union Carbide Co.)
After stirring and kneading for a minute, the mixture was extracted to produce a photoreactive hot melt adhesive.

Using a roll coater set at 130 ° C., the photoreactive hot-melt adhesive obtained above was used as an adherend (B) having no cation polymerization reaction inhibitory property as an SPCC dull steel sheet (25 mm in width). × length 125 mm × thickness 1.6 mm) so as to have a coating thickness of 300 µm and a coating length of 25 mm from the end. Next, using a high-pressure mercury lamp (trade name “Jetlight JL2300”, manufactured by ORK Mfg. Co., Ltd.), a wavelength of 36 nm was applied to the surface of the coated adhesive.
Light (ultraviolet light) was applied for 60 seconds so that the illuminance of 5 nm light was 25 mW / cm ² . Next, light irradiation end 1
After 0 seconds, a polyimide resin film (width 25 mm x length 125 mm) is attached as the adherend (A) having a cationic polymerization reaction inhibiting property, the bonding area is width 25 mm x length 25 mm, and both ends are in the same direction. They were pasted together. Next, in order to prevent the polyimide resin film from adhering to the SPCC dull steel sheet during hot pressing, a polyethylene terephthalate film (both sides demolded) that has been subjected to mold release treatment on both sides in advance between the SPCC dull steel sheet and the polyimide resin film PET), temperature 75 ° C, pressure 4
Hot pressing was performed for 1 minute under the condition of 9 kPa to produce a joined body of the SPCC dull steel plate and the polyimide resin film. This was used as a test piece for measuring peel adhesion strength. In addition, one end of the polyimide resin film was overlapped so that the bonding area was 25 mm in width × 25 mm in length, and the other end was bonded in the opposite direction. Next, in order to prevent the polyimide resin film from adhering to the SPCC dull steel plate during hot pressing, a double-sided release PET is sandwiched between the SPCC dull steel plate and the polyimide resin film in advance, at a temperature of 75 ° C and a pressure of 49 kPa. A hot press was performed for 1 minute to produce a joined body of the SPCC dull steel plate and the polyimide resin film. This was used as a test piece for measuring heat resistance.

(Example 2) Epoxy resin (trade name "Epicoat 4010P", manufactured by Yuka Shell Epoxy) 20
Part, epoxy resin (trade name “Epicoat 4004P”,
10 parts of Yuka Shell Epoxy Co., Ltd.) and 10 parts of polytetramethylene glycol (weight average molecular weight: 650, manufactured by Mitsubishi Chemical Corporation) are put into a planetary mixer equipped with a jacket capable of circulating heated oil, and the surface is made of aluminum. After covering with a foil, the mixture was stirred and kneaded at 170 ° C. at a rotation speed of 30 rpm for 60 minutes. Next, while continuing stirring, the temperature of the content was lowered to 130 ° C., and 0.8 part of an aromatic sulfonium salt “Siracure UVI-6990” was added as a photocationic polymerization initiator, followed by stirring for 10 minutes. After kneading, it was extracted and a photoreactive hot melt adhesive was produced.

The same procedure as in Example 1 was carried out except that the photoreactive hot-melt adhesive obtained above was used.
A joined body of the SPCC dull steel plate and the polyimide resin film was produced.

Example 3 Using a hot-melt coater (manufactured by Nordson), the photoreactive hot-melt adhesive obtained in Example 1 was subjected to a mold-releasing treatment on one side with a single-sided release PET ( The product is coated at 130 ° C. so that the coating thickness becomes 300 μm on the release treated surface of the product number “5011” (manufactured by Lintec Corporation), and the release treated surface of another single-sided release PET “5011” is laminated. A photoreactive hot melt adhesive sheet having a thickness of 300 μm was prepared, and the photoreactive hot melt adhesive sheet was cut into a size of 25 mm in width × 25 mm in length. Next, the one-sided release PET on one side was peeled off, and the wavelength of 365 nm was applied to the exposed surface of the photoreactive hot melt adhesive sheet using a high pressure mercury lamp “Jetlight JL2300”.
Was irradiated for 60 seconds so that the illuminance of the light was 25 mW / cm ² . Next, 10 seconds after the end of the light irradiation, a polyimide resin film (25 mm wide × 125 m long) was used as the adherend (A) having a cationic polymerization reaction inhibiting property.
m) was bonded so that the bonding length was 25 mm from the end, and then the single-sided release PET on the other surface was peeled off.
An SPCC dull steel plate (width 25 mm x length 125 mm x thickness 1.6 mm) was used as the adherend (B) having no cationic polymerization reaction inhibition property, and the bonding area was 25 mm width x 2 length.
Attachment was performed so that both ends overlapped in the same direction at 5 mm. Next, in order to prevent the polyimide resin film from adhering to the SPCC dull steel plate during hot pressing,
A double-sided release PET was sandwiched between the PCC dull steel plate and the polyimide resin film, and hot-pressed at a temperature of 75 ° C. and a pressure of 49 kPa for 1 minute to produce a joined body of the SPCC dull steel plate and the polyimide resin film. This was used as a test piece for measuring peel adhesion strength. In addition, SPCC dull steel plate (width 25mm x length 125mm x thickness 1.6m)
m) were laminated such that one end was overlapped so that the bonding area was 25 mm wide × 25 mm long, and the other end was located in the opposite direction. Next, in order to prevent the polyimide resin film from adhering to the SPCC dull steel plate during hot pressing, a double-sided release PET is sandwiched between the SPCC dull steel plate and the polyimide resin film in advance, at a temperature of 75 ° C and a pressure of 49 kPa. A hot press was performed for 1 minute to produce a joined body of the SPCC dull steel plate and the polyimide resin film. This was used as a test piece for measuring heat resistance.

Example 4 A photoreactive hot-melt adhesive sheet and an SPCC dull steel sheet were prepared in the same manner as in Example 3 except that the photoreactive hot-melt adhesive obtained in Example 2 was used. And a polyimide resin film were produced.

(Comparative Example 1) Using a roll coater set at 130 ° C, the photoreactive hot melt adhesive obtained in Example 1 was used as an adherend (A) having a cationic polymerization reaction inhibiting property. Polyimide resin film (25 mm width x
(Length 125 mm) so that the coating thickness was 300 μm and the coating length was 25 mm from the end. Next, using a high-pressure mercury lamp “Jetlight JL2300”, a wavelength of 365 was applied to the surface of the coated photoreactive hot-melt adhesive.
Light (ultraviolet light) was applied for 60 seconds so that the illuminance of the light having a wavelength of 25 nm was 25 mW / cm ² . Then, 10 seconds after the end of the light irradiation, the adherend (B) having no cationic polymerization reaction inhibitory property
As SPCC dull steel plate (width 25mm x length 125mm
× thickness 1.6mm), the bonding area is width 25mm ×
The pieces were bonded so that both ends were overlapped in the same direction at a length of 25 mm. Next, in order to prevent the polyimide resin film from adhering to the SPCC dull steel plate during hot pressing,
A double-sided release PET is sandwiched between the SPCC dull steel sheet and the polyimide resin film at a temperature of 75 ° C and a pressure of 49 kPa in advance.
The hot press was performed for 1 minute under the conditions described above to prepare a joined body of the SPCC dull steel sheet and the polyimide resin film. This was used as a test piece for measuring peel adhesion strength. Also, SP
CC dull steel plate (width 25mm x length 125mm x thickness 1.
6mm), the bonding area is 25mm wide x 25m long
One end was overlapped so as to obtain m, and the other end was stuck in the opposite direction. Next, in order to prevent the polyimide resin film from adhering to the SPCC dull steel plate during hot pressing, sandwich the double-sided release PET in advance between the SPCC dull steel plate and the polyimide resin film,
A hot press was performed for 1 minute at a temperature of 75 ° C. and a pressure of 49 kPa to produce a joined body of the SPCC dull steel plate and the polyimide resin film. This was used as a test piece for measuring heat resistance.

Comparative Example 2 A joined body of an SPCC dull steel sheet and a polyimide resin film was produced in the same manner as in Comparative Example 1 except that the photoreactive hot-melt adhesive obtained in Example 2 was used. Was prepared.

(Comparative Example 3) Using a hot melt coater (manufactured by Nordson), the photoreactive hot melt type adhesive obtained in Example 1 was applied to the release treated surface of a single-sided release PET “5011”. 130 ° C so that the working thickness is 300 μm
And a release treatment surface of another single-sided release PET “5011” is laminated to produce a photoreactive hot-melt adhesive sheet having a thickness of 300 μm. It was cut to a size of 25 mm in length.
Next, the single-sided release PET on one side was peeled off, and the surface of the exposed photoreactive hot melt adhesive sheet was exposed to light at a wavelength of 365 using a high-pressure mercury lamp “Jetlight JL2300”.
Light (ultraviolet light) was applied for 60 seconds so that the illuminance of the light having a wavelength of 25 nm was 25 mW / cm ² . Then, 10 seconds after the end of the light irradiation, the adherend (B) having no cationic polymerization reaction inhibitory property
As SPCC dull steel plate (width 25mm x length 25mm x
(1.6mm thickness) and the length is 25mm from the end
After laminating so that the other side of the single-sided release PE
T is peeled off, and a polyimide resin film (width 25 mm x length 125 mm) is adhered as an adherend (A) having a cationic polymerization reaction inhibiting property, and the bonding area is width 25 mm x length 25 mm, and both ends are in the same direction. And then stuck together. Next, in order to prevent the polyimide resin film from adhering to the SPCC dull steel plate during hot pressing, a double-sided release PET is sandwiched between the SPCC dull steel plate and the polyimide resin film in advance, at a temperature of 75 ° C and a pressure of 49 kPa. A hot press was performed for 1 minute to produce a joined body of the SPCC dull steel plate and the polyimide resin film. This was used as a test piece for measuring peel adhesion strength. In addition, one end of the polyimide resin film was overlapped so that the bonding area was 25 mm in width × 25 mm in length, and the other end was bonded in the opposite direction. Next, when hot pressing, the polyimide resin film
Double-sided release PET between SPCC dull steel sheet and polyimide resin film to prevent adhesion to dull steel sheet.
, And hot-pressed for 1 minute at a temperature of 75 ° C. and a pressure of 49 kPa to produce a joined body of the SPCC dull steel sheet and the polyimide resin film. This was used as a test piece for measuring heat resistance.

Comparative Example 4 A photoreactive hot melt adhesive sheet and an SPCC dull steel sheet were prepared in the same manner as in Comparative Example 3 except that the photoreactive hot melt adhesive obtained in Example 2 was used. And a polyimide resin film were produced.

The performances (peeling adhesive strength and heat resistance) of the joined bodies obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were evaluated by the following methods. The results were as shown in Table 1.

Peel adhesive strength: 23 ° C.-65%
After curing for 7 days in an atmosphere of RH, a 180 ° angle peel test was performed under the same atmosphere using a tensile tester in accordance with JIS K-6854 “Testing method for peeling adhesive strength of adhesive”. The peel adhesion strength (N / 25 mm) was measured. Heat resistance: The bonded body was heated at 23 ° C-65% RH in an atmosphere of 7%.
After curing for one day, 0.0294 MPa (300 g / c) was applied to one end (non-adhesive end) of the polyimide resin film in the shearing direction.
m ² ) Hang the weight so that a static load is applied, put it in an oven, raise the temperature to 200 ° C. at a heating rate of 0.6 ° C./min, and measure the temperature at which the polyimide resin film peels and falls. And heat resistance (° C.).

[0073]

[Table 1]

As is clear from Table 1, the joined bodies of Examples 1 to 4 produced by the bonding method of the present invention were made of a photoreactive hot-melt adhesive and a photoreactive hot-melt adhesive sheet made of polyimide resin. Since the film was not affected by the cationic polymerization reaction inhibitory property of the film, it exhibited excellent peel adhesion strength and excellent heat resistance.

On the other hand, in the joined body of Comparative Example 1 produced by applying a photoreactive hot-melt adhesive to a polyimide resin film and then irradiating the polyimide resin film, the polyimide resin film inhibited the cationic polymerization reaction. As compared with the joined body of Example 1, the peel adhesive strength and heat resistance were poor.
Further, the joined body of Comparative Example 2 produced by the same method as that of Comparative Example 1 was affected by the cationic polymerization reaction inhibitory property of the polyimide resin film of the photoreactive hot-melt adhesive. The heat resistance was poor as compared with the joined body of No. 2.

Further, in the joined body of Comparative Example 3 produced without bonding the polyimide resin film to the light-irradiated surface of the photoreactive hot melt adhesive sheet, the polyimide resin film inhibited the cationic polymerization reaction. Peel strength and heat resistance were inferior to those of the joined body of No.
In addition, the joined body of Comparative Example 4 produced by the same method as that of Comparative Example 3 had poor heat resistance as compared with the joined body of Example 4 because the polyimide resin film inhibited the cationic polymerization reaction. .

[0077]

As described above, in the bonding method of the present invention, the photoreactive hot-melt type adhesive or the photoreactive hot-melt adhesive sheet is used before bonding with the adherend having the cationic polymerization reaction inhibiting property. Since light irradiation is performed, the cationically polymerizable compound contained in the hot melt adhesive and the hot melt adhesive sheet has already started a cationic polymerization reaction, and the Lewis base contained in the adherend It is hardly affected by the cationic polymerization reaction inhibitory action due to contact. In addition, since the cationically polymerizable compound at the time of bonding to the adherend has not yet terminated the cationic polymerization reaction, it may react to some extent with the interface of the adherend. Therefore, according to the bonding method of the present invention, even when at least one of the adherends is an adherend having a cationic polymerization reaction inhibitory property, it is possible to obtain a bonded body that exhibits excellent adhesive strength and excellent heat resistance. Can be.

The bonding method of the present invention is suitably applied to the production of various conjugates when at least one of the adherends has an inhibitory effect on the cationic polymerization reaction. The present invention is particularly suitably applied to the production of an IC card using an inlet film having properties. That is, according to the bonding method of the present invention, a high-performance IC card exhibiting excellent adhesive strength and excellent heat resistance can be efficiently manufactured.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4J040 CA061 CA062 CA081 CA082 CA091 CA092 CA161 CA162 DA031 DA032 DA051 DA052 DA111 DA112 DB041 DB042 DB051 DB052 DC031 DC032 DC041 DC042 DC071 DC072 DD021 DD022 DF031 DD052 DD031 DD051 DF081 DF082 EB011 EB012 EC031 EC032 EC041 EC042 EC061 EC062 EC171 EC172 EC211 EC212 EC231 EC232 ED001 ED002 EF021 EF022 EF031 EF032 EL021 EL022 JA06 JA12 JB01 JB07 KA13 KA15 LA06 PA18 MA18

Claims (4)

[Claims] 1. A method for bonding a photoreactive hot-melt adhesive comprising a cationically polymerizable compound having an average of at least one cationically polymerizable reactive group per molecule and a cationic photopolymerization initiator, comprising: When bonding the adherend (A) having no polymerization reaction inhibition and the adherend (B) having no cationic polymerization reaction inhibition, the hot-melt adhesive is heated and melted on the adherend (B). Coating, then
A method for bonding a photoreactive hot-melt adhesive, which comprises irradiating the surface of the hot-melt adhesive with light and then bonding the adherend (A) to the light-irradiated surface. 2. A method for bonding a photoreactive hot-melt adhesive comprising a cationically polymerizable compound having an average of at least one cationically polymerizable reactive group per molecule and a cationic photopolymerization initiator, comprising: When the adherends (A) having a polymerization reaction inhibiting property or the adherends (A) having a cationic polymerization reaction inhibiting property and the adherend (B) having no cationic polymerization reaction inhibiting property are adhered to each other, A photoreactive hot-melt adhesive sheet made of a photoreactive hot-melt adhesive is prepared, and one or both sides of the hot-melt adhesive sheet are irradiated with light, and then the adherend (A) is attached to the light-irradiated surface. A method for bonding a photoreactive hot-melt adhesive, which is characterized by combining. 3. The method for bonding a photo-reactive hot melt adhesive according to claim 1, wherein the photo-reactive hot melt adhesive further comprises a thermoplastic resin. . 4. The photoreactive hot water according to claim 1, wherein the adherend (A) having a cationic polymerization reaction inhibiting property is an inlet film constituting an IC card. Bonding method of melt type adhesive.