JP4231870B2 - Reactive hot melt adhesive composition and bonding method - Google Patents

Description

The present invention relates to a reactive hot-melt adhesive composition that is applied by heat-melt coating and cures by irradiation with active energy rays, and a bonding method using the same, and more specifically, the curing speed is increased. The present invention relates to a reactive hot melt adhesive composition and an adhesion method.

Hot melt adhesives are widely used to bond paper, fiber, wood, glass, plastic, metal, etc. in various fields such as bookbinding, wrapping, textile processing, woodworking, weak electricity or transportation.

When bonding with a hot melt adhesive, the hot melt adhesive is usually heated and melted at a temperature of about 100 to 200 ° C. in the applicator. Next, a hot melt adhesive in a molten state is applied to the adherends, and the adherends are bonded together. The adherends are bonded to each other by cooling and solidifying the hot melt adhesive.

In the case of a hot melt adhesive, the adhesive strength is quickly increased by cooling and solidification. Therefore, the time until the sufficient adhesion strength is achieved after the adherends are bonded is usually very short, within 1 minute. Therefore, the bonding operation can be completed in a short time.

However, in the above hot melt adhesive, an adhesive force is expressed when the adhesive is solidified. Therefore, even if the adherends are once bonded to each other through the hot melt adhesive, the hot melt adhesive is exposed to a high temperature atmosphere. There was a problem that the adhesive was softened or melted, and the adhesive strength was significantly reduced. As a solution to such a problem, a reactive hot melt adhesive containing a urethane prepolymer having an isocyanate group at a molecular end, an ethylene-vinyl acetate copolymer, and a tackifying resin has been proposed (patent) Reference 1).

However, even in the reactive hot melt adhesive described in this prior art, after applying the hot melt adhesive to one or both adherends, and increasing the application time until the adherends are bonded together, There was a problem that the curing progressed due to moisture in the surrounding atmosphere, and adhesion could not be achieved. In addition, there is a problem in that it takes a long time for the adhesive to exhibit heat resistance after bonding, and it varies greatly depending on the season and weather.
Japanese Patent Publication No. 51-30898

The object of the present invention is to adhere the adherends to each other reliably and to exhibit heat resistance after bonding even when the application time from application to bonding to bonding is sufficiently long. It is an object to provide a reactive hot melt adhesive that is short in time and hardly affected by the season and weather, and a bonding method using the same.

The reactive hot melt adhesive composition according to the first aspect of the present invention comprises a bisphenol-type epoxy resin having a softening point of 50 to 180 ° C. according to a ring and ball measurement method, an epoxy compound other than a bisphenol-type epoxy resin, and an activity. A reactive hot melt adhesive composition comprising a cationic polymerization initiator for polymerizing and curing a cationically polymerizable compound by irradiation with energy rays, wherein the epoxy compound is a terminal epoxidized polyether polyol And

Furthermore, the reactive hot melt adhesive composition according to another aspect of the present invention includes a polymer block mainly composed of a vinyl aromatic compound, a polymer block mainly composed of a conjugated diene compound, or a partially hydrogenated product thereof. An epoxy-modified block copolymer obtained by epoxidizing an unsaturated carbon double bond of a conjugated diene compound of a block copolymer having a polymer block in the same molecule, an epoxy compound, and a cation by irradiation with active energy rays And a cationic polymerization initiator for cationically polymerizing and curing the polymerizable compound.

As the cationic polymerization initiator, at least one selected from the group consisting of an aromatic iodonium salt, an aromatic sulfonium salt, and a metallocene salt as described in claim 2 is preferably used.

Further, the invention described in claim 3 is a method in which the reactive hot melt adhesive composition according to any one of claims 1 and 2 is heated and melted and applied in a molten state to one or both of the adherends. It is an adhesion method characterized in that the reactive hot melt adhesive composition is irradiated with active energy rays, and then the adherends are bonded together and pressure-bonded at room temperature or under heating.
The present invention is described in detail below.

(Epoxy Modified Block Copolymer in Reactive Hot Melt Adhesive Composition According to Another Embodiment of the Present Invention)
In another embodiment of the present invention, the epoxy-modified block copolymer includes a polymer block mainly composed of a vinyl aromatic compound, a polymer block mainly composed of a conjugated diene compound, or a partially hydrogenated product thereof, as described above. The conjugated diene compound of the block copolymer having the same polymer block in the same molecule is epoxidized with an unsaturated carbon double bond, and constitutes a cationically polymerizable compound.

Examples of the vinyl aromatic compound constituting the polymer block mainly composed of the vinyl aromatic compound include styrene, α-methylstyrene, vinyltoluene, p-tertiary butylstyrene, divinylbenzene, p-methylstyrene, Examples thereof include 1,1-diphenylstyrene, and one or more of these can be used, and among them, styrene is preferable.

Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene, phenyl-1,3- Butadiene can be used, and one or more of these can be used. Of these, butadiene, isoprene and combinations thereof are preferable.

Here, the block copolymer refers to a block copolymer composed of a polymer block mainly composed of a vinyl aromatic compound and a polymer block mainly composed of the conjugated diene compound. The copolymerization ratio of the vinyl aromatic compound and the conjugated diene compound is preferably in the range of 5:95 to 70:30 by weight.

The weight average molecular weight of the block copolymer is preferably in the range of 10,000 to 400,000, and the ratio Mw / Mn between the weight average molecular weight Mw and the number average molecular weight Mn is preferably 10 or less.

The molecular structure of the block polymer may be linear, branched, radial, or any combination thereof. Furthermore, the unsaturated bond of the conjugated diene compound of the block polymer may be partially hydrogenated.

The epoxy-modified block copolymer is obtained by epoxidizing the above-described block copolymer. For example, it can be obtained by reacting the block copolymer with an epoxidizing agent such as hydroperoxides and peracids in an inert solvent.

As an epoxy-modified block copolymer obtained by epoxidizing the unsaturated carbon double bond of the conjugated diene compound as described above, an epoxidized styrene butadiene styrene copolymer (trade name: Epofriend A1020, manufactured by Daicel Chemical Industries, Ltd.) ) Etc. can be used.

(Epoxy compound used in another embodiment of the hot melt adhesive assembly of the present invention)
In a reactive hot melt adhesive composition according to another aspect of the present invention, the epoxy compound is a compound other than the above-described epoxy-modified block copolymer, and has at least one oxirane ring that can be polymerized by cationic polymerization. The epoxy compound may be a monomer, an oligomer, or a polymer, and may be any aliphatic, alicyclic, or aromatic epoxy compound. The epoxy compound preferably has an average of 1 or more epoxy groups per molecule, more preferably an average of 2 or more epoxy groups per molecule.

The number of “average” per molecule of epoxy groups can be obtained by dividing the number of epoxy groups in the epoxy compound by the total number of epoxy molecules present.

Examples of the epoxy compound that is a polymer include a linear polymer having a terminal epoxy group (for example, diglycidyl ether of polyoxyalkylene glycol), a polymer having an oxirane unit in the skeleton (for example, polybutadiene polyepoxide), and an epoxy in the side chain. And a polymer having a group (glycidyl (meth) acrylate polymer or copolymer).

The molecular weight of the epoxy compound is not particularly limited, but may range from about 58 to about 100,000. Specific examples of the epoxy compound include, for example, aromatic epoxy resins such as bisphenol A type epoxy resin, alicyclic epoxy resins such as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, Aliphatic epoxy resins such as methylolpropane triglycidyl ether, 2,2-bis [4- (2,3-epoxypropoxy) cyclohexyl] propane, and oxirane rings in the molecule such as glycidyl (meth) acrylate (meth) Examples include, but are not limited to, acrylate polymers or copolymers, epoxidized polybutadiene, and epoxidized products of copolymers of butadiene and other monomers, and modified products of these respective epoxy resins. Absent. Moreover, the said epoxy compound may be used independently and may be used together 2 or more types.

Moreover, the said epoxy compound has a preferable thing compatible with the epoxy modified block copolymer mentioned above, and an epoxidized unsaturated oil and an epoxidized polybutadiene can be mentioned as a particularly preferable epoxy compound. Examples of the epoxidized unsaturated oil include epoxidized linseed oil and epoxidized soybean oil, but are not particularly limited thereto.

In addition, the epoxidized polybutadiene includes epoxidized unsaturated carbon double bonds of polybutadiene or partially hydrogenated polybutadiene; polybutadiene or partially hydrogenated polybutadiene, or fully hydrogenated polybutadiene. Although the thing which introduce | transduced the epoxy group into the terminal can be mentioned, it does not specifically limit to these.

It is preferable to mix | blend the said epoxy compound in 5-400 weight part with respect to 100 weight part of epoxy modified block copolymers, More preferably, it is the range of 10-200 weight part. When the blending ratio is less than 5 parts by weight, the progress of the cross-linking reaction is slow, and it may take a long time until the post-adhesion heat resistance is developed. In some cases, the cohesive strength of the resin decreases and the adhesive strength immediately after bonding decreases.

(Bisphenol Type Epoxy Resin and Epoxy Compound According to Invention of Claim 1) In the reactive hot melt adhesive composition according to the invention of claim 1, the bisphenol type epoxy resin is used. The epoxy resin is not particularly limited as long as the softening point by the ring and ball measurement method is in the range of 50 to 180 ° C., and is not limited to bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol. Any bisphenol-type epoxy resin such as an S-type epoxy resin can be used.

When the softening point of the bisphenol-type epoxy resin is lower than 50 ° C., the cohesive force as a hot melt adhesive is lowered, and the adhesive strength immediately after the bonding is reduced. On the other hand, when the temperature is higher than 180 ° C., the melt viscosity becomes extremely high and it becomes difficult to blend the adhesive, and when the temperature is raised to facilitate blending, thermal deterioration of the adhesive is caused.

In addition, you may use together the said bisphenol type epoxy resin 2 or more types. Specific examples of the bisphenol type epoxy resin include a product name: Epicoat 1004 (bisphenol A type epoxy resin) manufactured by Yuka Shell Epoxy Co., Ltd.

In the reactive hot melt adhesive composition according to the first aspect of the present invention, the epoxy compound may be at least one polymerizable by cationic polymerization, similar to the epoxy compound according to the first aspect of the present invention. What consists of an organic compound which has an oxirane ring can be used. However, in another aspect of the invention, it is necessary to use an epoxy compound other than the bisphenol-type epoxy resin as the epoxy compound. Since it is the same as that of the epoxy compound used in the reactive hot-melt-adhesive composition which concerns on another aspect of this invention about another point, using description of the epoxy compound about this invention of another aspect, and To do.

That is, in the reactive hot melt adhesive according to the invention described in claim 1, the epoxy compound may be any of a monomer, an oligomer, and a polymer, such as aliphatic, alicyclic, and aromatic. Those having various structures can be used, and preferably those having one or more epoxy groups per molecule, more preferably those having two or more epoxy groups per molecule are used. Moreover, what was mentioned above can also be used about a polymer epoxy compound.

In the reactive hot melt adhesive composition according to the first aspect of the present invention, the epoxy compound is preferably blended in a proportion of 5 to 400 parts by weight, more preferably 100 parts by weight of the bisphenol type epoxy resin. Is blended at a ratio of 10 to 200 parts by weight. When the blending ratio of the epoxy compound is less than 5 parts by weight, the progress of the cross-linking reaction is slow, and the time until the heat resistance after adhesion is developed may be long. Moreover, when more than 400 weight part, the cohesion force as a hot-melt-adhesive agent will fall, and the adhesive strength immediately after adhesion | attachment will become small.

In the invention according to claim 1, a terminal epoxidized polyether polyol is particularly preferable as the epoxy compound. The terminal epoxidized polyether polyol is a glycidyl ether of a polyol having a polyalkylene glycol structure in the molecule such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and preferably at least one at the end of the molecular chain, preferably at least It has two epoxy groups.

Here, the polyol having the polyalkylene glycol structure in its molecule includes polyhydroxyalkanes (ethylene glycol, propylene glycol, trimethylolpropane, glycerin, etc.), non-reducing sugars and sugar derivatives (sorbitol, sucrose, etc.), polyphenols. It can be obtained by adding alkylene oxide or the like to a hydroxyl group-containing compound such as (bisphenol A, bisphenol F, etc.) or natural oil (castor oil, etc.). Two or more of the terminal epoxidized polyether polyols may be used in combination.

(Poval and epoxy compound in the reactive hot melt adhesive according to another aspect of the invention)
In the reactive hot melt adhesive according to another aspect of the invention, poval is used as described above. The poval is not particularly limited as long as it is obtained by saponifying polyvinyl acetate, but the saponification degree is preferably 0.1 to 60%, more preferably 1 to 40%. When the saponification degree is smaller than 0.1% and larger than 60%, the progress of the cross-linking reaction becomes slow, and it may take a long time to develop heat resistance after adhesion. The “degree of saponification” refers to the ratio of the number of hydroxyl groups after saponification to the number of acetate groups of polyvinyl acetate before saponification.

Moreover, it is desirable that the poval has a softening point in the range of 40 to 180 ° C. according to the ring and ball measurement method. When the softening point is lower than 40 ° C., the cohesive force as a hot melt adhesive is reduced, and the adhesive strength immediately after bonding may be reduced. When the softening point is higher than 180 ° C., the melt viscosity becomes extremely high, so May be difficult, and if the temperature is increased to facilitate blending, thermal deterioration of the adhesive may be caused. About the said poval, you may use 2 or more types together. Poval can be produced by a known method such as an acid saponification method or an alkali saponification method.

In another aspect of the invention, as the epoxy compound, any epoxy compound composed of an organic compound having at least one oxirane ring that can be polymerized by cationic polymerization can be used. About such an epoxy compound, since the epoxy compound similar to the epoxy compound used in this invention of another aspect can be used, suppose that description of the epoxy compound in this invention of another aspect is used.

That is, in another aspect of the invention, the epoxy compound may be in any form of a monomer, an oligomer, or a polymer, and has any structure such as aliphatic, alicyclic, and aromatic. There may be. Moreover, an epoxy compound having one or more epoxy groups per molecule is preferably used, and an epoxy compound having two or more epoxy groups per molecule is more preferably used.

Moreover, the polymer epoxy compound mentioned above can also be used, and also about an epoxy compound, you may use 2 or more types together. However, in another aspect of the invention, it is preferable that the above epoxy compound is compatible with POVAL uniformly. As such an epoxy compound, bisphenol A type epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd. Name: Epicoat 828, manufactured by Union Carbide Corporation, alicyclic epoxy resin, trade name: ERL4221, etc.

The epoxy compound is preferably blended at a rate of 5 to 400 parts by weight, more preferably 10 to 200 parts by weight, with respect to 100 parts by weight of Poval. If the blending ratio is less than 5 parts by weight, the progress of the cross-linking reaction is delayed, and it may take a long time to develop the heat resistance after bonding. If it exceeds 400 parts by weight, the heat resistance after bonding due to the addition of poval The effect of shortening the time until the onset of sex may not be sufficiently obtained.

(Ethylene-glycidyl (meth) acrylate copolymer in a reactive hot melt adhesive according to another aspect of the invention)
In the reactive hot melt adhesive composition according to another aspect of the invention, an ethylene-glycidyl (meth) acrylate copolymer is used as the cationic polymerizable compound, and as this ethylene-glycidyl (meth) acrylate copolymer, Is not particularly limited, but is preferably obtained by copolymerizing 10 to 99.9% by weight of ethylene and 90 to 0.1% by weight of glycidyl acrylate or glycidyl methacrylate, Preferably, those obtained by copolymerizing ethylene at a ratio of 50 to 99.9% by weight of ethylene and 50 to 0.1% by weight of glycidyl acrylate or glycidyl methacrylate are used.

When the ethylene content is more than 99.9% by weight, the progress of the cross-linking reaction is slowed down, and the time until the heat resistance after adhesion is developed may be longer. When the ethylene content is less than 10% by weight, The cohesive force as a hot melt adhesive may be reduced, and the adhesive strength immediately after bonding may be reduced.

The ethylene-glycidyl (meth) acrylate copolymer preferably has a softening point in the range of 40 to 180 ° C. by a ring and ball measurement method. When the softening point is lower than 40 ° C., the cohesive force as a hot melt adhesive may be reduced, and the adhesive strength immediately after bonding may be reduced. When the softening point is higher than 180 ° C., the melt viscosity becomes extremely high, and the adhesive composition is increased. In addition, if the temperature is increased to facilitate blending, thermal deterioration of the adhesive may be caused.

The ethylene-glycidyl (meth) acrylate copolymer may be a multi-component copolymer obtained by polymerizing another radical polymerizable monomer. Examples of such copolymerizable radical polymerizable monomers include, but are not limited to, vinyl acetate, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and the like. It is not a thing.

The ethylene-glycidyl (meth) acrylate copolymer may be used in combination of two or more, and the ethylene-glycidyl (meth) acrylate copolymer is produced by a known method such as a conventional free radical polymerization method. be able to.

Specific examples of the ethylene-glycidyl (meth) acrylate copolymer include, for example, trade name: Bond First CG5001 (reactive ethylene-glycidyl methacrylate copolymer) manufactured by Sumitomo Chemical Co., Ltd., and trade name: Examples include Bond First 20M.

(Hydroxyl group-containing polyolefin as an optional component in another aspect of the invention)
In the reactive hot melt adhesive composition according to another aspect of the invention, preferably, a hydroxyl group-containing polyolefin is further blended. The hydroxyl group-containing polyolefin is not particularly limited as long as it is uniformly compatible with the ethylene-glycidyl (meth) acrylate copolymer, and may be a liquid, a solid, or at least one, Those having at least two hydroxyl groups are preferably used. The hydroxyl group may be at the molecular end or may be a side group of a polymer or copolymer.

Examples of the hydroxyl group-containing polyolefin include, but are not limited to, hydrogenated polybutadiene having a terminal hydroxyl group.

Two or more of the hydroxyl group-containing polyolefins may be used in combination. The hydroxyl group-containing polyolefin can be produced by a known method.

When the hydroxyl group-containing polyolefin is solid, the softening point by ring-and-ball measurement is preferably 100 ° C. or less. When the softening point is higher than 100 ° C., the progress of the crosslinking reaction is slow, and the time until the heat resistance is developed after adhesion may be long.

The hydroxyl group-containing polyolefin is blended in an amount of preferably 5 to 400 parts by weight, more preferably 10 to 200 parts by weight with respect to 100 parts by weight of the ethylene-glycidyl (meth) acrylate copolymer. When the blending ratio of the hydroxyl group-containing polyolefin is less than 5 parts by weight, the effect of shortening the time until the heat resistance after adhesion due to the hydroxyl group-containing polyolefin is expressed may not be sufficiently obtained. When it exceeds, progress of a crosslinking reaction will become slow and time until heat resistance after adhesion | attachment may be expressed may become long.

(Cationic polymerization initiator)
The cationic polymerization initiator is not particularly limited as long as it can generate a cation for initiating polymerization of a cationically polymerizable compound by irradiation with active energy rays. Preferably, aromatic iodonium is used. Salts, aromatic sulfonium salts, and / or metallocene salts. The above-mentioned aromatic iodonium salts and aromatic sulfonium salts useful as cationic polymerization initiators are disclosed, for example, in US Pat. No. 4,256,828. The metallocene salt is disclosed in US Pat. No. 5,089,536. The amount of the cationic polymerization initiator varies depending on the type and intensity of the active energy ray, the type and amount of the cationic polymerizable compound, the type of the cationic polymerization initiator, and the like, but preferably with respect to 100 parts by weight of the cationic polymerizable compound. 0.01 to 10 parts by weight is blended.

(Other ingredients that can be added)
If necessary, the reactive hot melt adhesive composition according to the present invention may contain a hydroxyl compound. In the reactive hot melt adhesive composition according to another aspect of the invention, as the hydroxyl compound, a hydroxyl compound other than the hydroxyl group-containing polyolefin is contained as necessary.

The hydroxyl compounds that can be used may be liquid or solid, but have at least one, preferably at least two hydroxyl groups. In this case, the hydroxyl group may be at the end of the compound and may be present in a side group of the polymer or copolymer.

Examples of the hydroxyl compound include alkylene glycol, polyhydroxyalkane, polyoxyalkylene polyol and the like, but are not limited thereto. Moreover, a hydroxyl compound may be added independently and may be used together 2 or more types.

Moreover, in the reactive hot-melt-adhesive composition which concerns on invention of another aspect , you may contain an epoxy compound as needed. As an epoxy compound in this case, since the thing similar to the epoxy compound used in the invention of Claims 1-2 can be used, suppose that description of these epoxy compounds is used.

Moreover, in the reactive hot melt adhesive composition according to the present invention, a hot melt resin can be added as necessary. That is, when the cationic polymerizable compound itself is a hot melt resin, it is not always necessary to use another hot melt resin, but when the cationic polymerizable compound is not a hot melt resin, hot melt adhesion is not necessary. In order to be able to be used as an agent, it is preferable to add a hot melt resin.

As the above-mentioned hot melt type resin, those having an appropriate molecular weight from low molecular weight to high molecular weight can be used. For example, they are commonly used as tackifying resins such as styrene resins, petroleum resins and natural resins. Resins, polyolefin resins such as ethylene-vinyl acetate copolymer resins, rubber resins such as butadiene-styrene block copolymers, acrylic copolymer resins, polyester resins, or a variety of these hot melt resins Examples of the modified products are not limited to these, and two or more of these hot melt resins may be used in combination.

Furthermore, in the reactive hot melt adhesive composition according to the present invention, if necessary, an adhesion improver (such as a silane coupling agent or a titanium coupling agent), a sensitizer, a dehydrating agent, an anti-aging agent. , Stabilizers, plasticizers, waxes, fillers, flame retardants, foaming agents, antistatic agents, antifungal agents, viscosity modifiers, and the like can be added. It is not limited to ingredients. Moreover, 2 or more types of the components which can be added may be added. In addition, these components may be added in advance during the production of the hot-melt type resin described above, and that case is also acceptable.

(Method for producing reactive hot melt adhesive composition)
As for the method for producing the reactive hot melt adhesive composition according to the present invention, any method may be adopted as long as the components to be blended can be mixed and uniformly dispersed. It is necessary to manufacture under the heating condition. In addition, mixing and dispersion of each component during production may be performed without a solvent or in an inert solvent. Specifically, it can be carried out by using one or more of a double helical ribbon bath or gate bath, a butterfly mixer, a planetary mixer, a three roll, a kneader-louder type kneader or an extruder type kneading extruder. However, the apparatus for kneading each component is not limited to these.

In the case of mixing and dispersing each component using any equipment, it is preferable to mix and disperse under anhydrous conditions since the mixing of moisture, which is a component that inhibits cationic polymerization, is reduced. In mixing and dispersing the components, mixing and dispersion is performed under atmospheric pressure, or if necessary, at or above atmospheric pressure.

In addition, the order of adding the components during production is not particularly limited, but in order to shorten the melting time or reduce the deterioration of the obtained composition, it is generally difficult to melt or It is desirable to prepare in order from those which are not easily deteriorated by heat or mechanical shearing force. In addition, when manufacturing the reactive hot-melt-adhesive composition which concerns on this invention, it is necessary to carry out in the state which interrupted the active energy ray effective for the start of hardening.

The method for storing the reactive hot melt adhesive composition is not particularly limited as long as it can block the active energy ray effective for initiation of curing, but preferred storage containers include pail cans, tin cans, and drum cans. , Containers, mold release boxes, mold release trays, cardboard containers, paper bags, plastic bags (for example, composite films sandwiched with aluminum foil), etc. Can do. However, it is not limited to these containers, and the material of these containers is not particularly limited as long as the active energy ray can be blocked. Moreover, the reactive hot melt adhesive composition according to the present invention may be used immediately after production without being stored.

(Adhesion method)
According to a third aspect of the present invention, there is provided a reactive hot melt adhesive in which the reactive hot melt adhesive composition is heated and melted and applied to one or both adherends in a molten state. After irradiating the composition with active energy rays, the adherends are bonded together and bonded by pressing at room temperature or under heating.

The method for applying the hot-melt adhesive composition by heating and melting is not particularly limited. 1. a method of applying a hot melt adhesive composition heated and melted by a normal hot melt applicator or hot melt coater to an adherend; 2. a method of immersing an adherend in a hot-melt reactive hot melt adhesive composition; 3. a method of spraying an adherend with a hot-melt adhesive composition heated and melted by a hot-melt air gun or the like; Examples thereof include a method of extruding a hot melt adhesive composition heated and melted by an extruder or the like onto the surface of an adherend.

Also, the hot melt adhesive composition may be supplied to the hot melt applicator using a pail unloader, cartridge dispenser, etc., and in the form of sticks, pellets, slugs, blocks, pillows, billets, etc. A melt adhesive composition may be supplied.

As for heating, the entire reactive hot melt adhesive composition may be heated and melted, or may be heated and melted only in the vicinity of the heating body. Whichever melt coating method is used, it is desirable that the melt coating be performed in a state where active energy rays effective for the start of curing are blocked.

As the active energy ray, an appropriate active energy ray can be used as long as a cation can be generated from the cationic polymerization initiator, and the type of active energy ray is appropriately selected according to the type of the cationic polymerization initiator. Preferably, light, in particular UV light, is used. Preferably, light having a wavelength of 200 to 600 nm is used. In particular, when an aromatic iodonium salt, aromatic sulfonium salt, metallocene salt, or the like is used as a cationic polymerization initiator, light having a wavelength of 200 to 400 nm should be used. Is desirable.

The irradiation amount of the active energy ray also varies depending on the type of the cationic polymerization initiator and the thickness and amount of the portion to which the reactive hot melt adhesive composition is applied. Desirably, the range is from 001J to 10J.

When ultraviolet rays are used as the source of active energy rays, those generally used as ultraviolet ray irradiation sources such as fluorescent lamps and high-pressure mercury lamps can be used.

As for the irradiation method of the active energy ray, the hot melt adhesive may be directly irradiated, or an effective amount of the active energy ray is applied to the hot melt adhesive through a transparent or translucent adherend. There is no particular limitation.

For bonding and bonding methods of adherends, 1. A method in which a reactive hot melt adhesive composition is applied to one adherend and then the other adherend is bonded and pressed at an appropriate pressure and temperature for a required time. Examples thereof include a method in which a reactive hot melt adhesive composition is applied to both adherends and then pressed at an appropriate pressure and temperature for a necessary time.

The reactive hot melt adhesive composition according to the present invention can be sufficiently cured by irradiation with the active energy ray under normal conditions, but may be heated to an appropriate temperature if it is desired to further shorten the curing time. . In this case, since the heating method differs depending on the type of the reactive hot melt adhesive composition, the shape and properties of the adherend, the heating conditions, etc., it cannot be uniquely determined. 1. a method of blowing warm air; 2. Place in a heated oven. A method of heating with a heater can be used, and two or more of these may be used in combination. However, the heating method is not limited to the above method. In addition, about the heating temperature in the case of shortening hardening time, it is desirable to set it as temperature lower than the temperature at which the reactive hot-melt-adhesive composition itself softens. Otherwise, the adhesive portion may be displaced due to the softening of the composition.

(Applicable adherend)
The adherend to which the reactive hot melt adhesive composition according to the present invention is applied and the adherend used in the bonding method according to the present invention are not particularly limited, but examples thereof include iron and aluminum. It can be applied to adherends made of a wide variety of materials such as metals or alloys, plastics or plastic mixtures, inorganic materials such as glass, concrete, stone, mortar and ceramic, cellulosic materials such as wood and paper, and leather. Also, the shape of the adherend may be in an appropriate form such as a plate, lump, rod, sheet, string, fiber, honeycomb, tube, particle, etc., and used for bonding adherends of different forms. Is also possible.

(Use)
The reactive hot melt adhesive composition according to the present invention can be used as a reactive hot melt adhesive, particularly as an elastic adhesive, a structural adhesive, a pressure sensitive adhesive, a sealing material, and the like. Such reactive hot-melt adhesive compositions include, for example, door panels, partitions, shutters, furniture, blackboards, white boards, adhesion of sandwich panels such as housing panels for office equipment, and surface materials, furniture, partitions. It is preferably used for applications such as adhesion between a core material and a surface material in door panels and ceiling materials of automobile interior materials. However, the use of the reactive hot melt adhesive is not limited to the above use.

Action The reactive hot melt adhesive composition according to the present invention is melted and softened by heating, and therefore can be applied to an adherend in the same manner as a normal hot melt adhesive. Moreover, after application | coating to a to-be-adhered body, a cationic polymerization initiator produces | generates a cation by irradiating an active energy ray, A cationically polymerizable compound superposes | polymerizes by this cation, and it will become high molecular weight, and hardening will advance. That is, in another aspect of the present invention, the epoxy-modified block copolymer and the epoxy compound are polymerized and curing proceeds. In the invention according to claim 1, the bisphenol-type epoxy resin and the epoxy compound are polymerized, Curing proceeds, and in another aspect of the invention, poval and epoxy compounds are polymerized and curing proceeds, and in another aspect of the invention, ethylene-glycidyl (meth) acrylate copolymer is polymerized and curing proceeds. To do. Therefore, in the present invention, an adhesive cured product having excellent heat resistance can be obtained, and the hot melt adhesive is less deteriorated by heat, so that the adhesive performance as designed can be surely exhibited.

Therefore, since the curing starts only by the irradiation of the active energy ray, after applying the reactive hot melt adhesive composition to the adherend, the active energy ray is irradiated in accordance with the bonding timing, so that the bonding is performed. It is possible to prevent the curing from proceeding before the alignment. In other words, the application time can be set to a sufficient length by timing the irradiation of active energy rays. In addition, since the curing proceeds by irradiation with active energy rays, the time from adhesion to the development of heat resistance is not affected by the humidity of the surrounding atmosphere.

Moreover, in another aspect of the present invention, a combination of the above-mentioned epoxy modified block copolymer and an epoxy compound. In the invention described in claim 1, in a combination of a bisphenol type epoxy resin and an epoxy compound, in another aspect of the invention. In another aspect of the invention, a combination of poval and an epoxy compound uses an ethylene-glycidyl (meth) acrylate copolymer, so that the cross-linking reaction proceeds faster and heat resistance is exhibited after bonding. The time until is shortened. That is, by combining the above-mentioned epoxy modified block copolymer, bisphenol type epoxy resin or poval with an epoxy compound, or by using an ethylene-glycidyl (meth) acrylate copolymer as a cationic polymerizable compound, the crosslinking reaction proceeds. Speeded up.

In the invention described in claim 2 , since an aromatic iodonium salt, aromatic sulfonium salt and / or metallocene salt is used as the cationic polymerization initiator, light as an active energy ray having a wavelength of 200 to 400 nm is irradiated. Thus, the curing can proceed promptly and the adhesive has excellent storage stability.

In the invention according to claim 3 , the reactive hot melt adhesive composition of the present invention is heated and melted, and then applied to one or both of the adherends in a molten state, and the applied reactive hot melt adhesive is applied. Adhesion is performed by irradiating the composition with the active energy ray and then bonding the adherend and then crimping at room temperature or under heating. By doing so, the application time can be lengthened. That is, by extending the time from application to irradiation with active energy rays, it is possible to extend the application time, and it is possible to set an optimal application time according to the application and the adhesion part.

Moreover, as described above, the reactive hot melt adhesive of the present invention, after bonding the crosslinking proceeds rapidly, because the time to heat expression is shortened, in the invention according to claim 3, after the bonding Exhibits sufficient heat resistance in a short time.

In addition, since the reactive hot melt adhesive composition cures only by irradiation with active energy rays, the time until the heat resistance is developed varies depending on the surrounding humidity and weather. hard.

In the reactive hot melt adhesive composition according to the present invention, it can be easily applied by heating and melting in the same manner as the conventional hot melt adhesive, and the epoxy modified block copolymer, bisphenol type epoxy resin or poval Since the epoxy compound or the ethylene-glycidyl (meth) acrylate copolymer is cured by increasing the molecular weight, the heat resistance of the adhesive cured product is enhanced, and the above-described various cationic polymerizable compounds are used. The reaction proceeds rapidly, and the time from bonding to the development of heat resistance is shortened.

In addition, since curing does not proceed until the high molecular weight of the cationic polymerizable compound proceeds by irradiation with active energy rays, the timing of irradiation with active energy rays is set after applying the reactive hot melt adhesive composition. By doing so, the application time can be extended. That is, even when the time until irradiation with active energy rays is extended after coating, the adherends can be easily bonded together because curing does not proceed until irradiation with active energy rays is performed.

Therefore, the application time can be set to an optimum time according to the application and the situation of the bonded portion. In addition, the time until the bonded cured product exhibits heat resistance after bonding is not greatly affected by the season or the weather.

In the bonding method according to the present invention, the reactive hot melt adhesive composition according to the present invention is heated and melted, and then applied to at least one of the adherends in a molten state, and the applied reactive hot melt adhesive composition is applied. The adherends are bonded to each other after being irradiated with active energy rays, and are bonded at room temperature or under heating. By adjusting the time from application to irradiation with active energy rays, the adherend The application time can be easily controlled according to the type and the adhesion part of the adhesive, and even in such a case, the adherends can be bonded together reliably, and the adhesive cured product has excellent heat resistance. Can be given.

In addition, since the various cationic polymerizable compounds described above are used, the cross-linking proceeds rapidly after bonding, and the time until heat resistance is developed is shortened. Therefore, the adhesive cured product can be suitably used for applications that require heat resistance.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Epoxy resin used)
In the following Examples and Comparative Examples, the following epoxy resins were used as appropriate.
Epoxy resin 1: manufactured by Daicel Chemical Industries, epoxidized styrene-butadiene-styrene, trade name: Epofriend A1020, 180 ° C. melt viscosity 4170 poise, butadiene / styrene weight ratio 60/40.

Epoxy resin 2—Daicel Chemical Industries, Epoxidized soybean oil, trade name: Daimac S-300K, liquid at room temperature, oxirane oxygen 7.0%.
Epoxy resin 3… manufactured by Nippon Soda Co., Ltd., epoxy resin modified polyptadiene, trade name: EPB-1054, liquid at normal temperature, epoxy equivalent 361.

Epoxy resin 4 ... made by Yuka Shell Epoxy Co., Ltd., bisphenol A type epoxy resin, trade name: Epicoat 1004, softening point 97 ° C, epoxy equivalent 875-975.
Epoxy resin 5: manufactured by Shin Nippon Rika Co., Ltd., bisphenol A-containing polyethylene glycol type epoxy resin, trade name: Rica Resin BEO-60E, liquid at normal temperature, epoxy equivalent 356.

Epoxy resin 6—manufactured by Nagase Kasei Co., Ltd., polyethylene glycol diglycidyl ether, trade name: Denacol EX-861, melting point 45 ° C., epoxy equivalent 587.
Epoxy resin 7: manufactured by Yuka Shell Epoxy Co., Ltd., bisphenol A type epoxy resin, trade name: Epicoat 828, liquid at room temperature, epoxy equivalents 184 to 194.
Epoxy resin 8: manufactured by Union Carbide Japan, alicyclic epoxy resin, trade name: ERL4221, pour point -37 ° C, epoxy equivalents 131-143.

(Used ethylene-glycidyl (meth) acrylate copolymer)
In the following examples and comparative examples, the following ethylene-glycidyl (meth) acrylate copolymer was used.

Copolymer 1 ... manufactured by Sumitomo Chemical Co., Ltd., ethylene copolymer, trade name: Bondfast CG5001, glycidyl methacrylate content 18% by weight, MFR 350 g / 10 min. Copolymer 2: manufactured by Sumitomo Chemical Co., Ltd., reactive ethylene copolymer, trade name: Bondfast 20M, glycidyl methacrylate content 6% by weight, methyl acrylate content 30% by weight, MFR 20 g / 10 min.

(Reference Example 1)
70 parts by weight of epoxy resin 1 as an epoxy-modified block copolymer, 30 parts by weight of epoxy resin 2, and a cationic polymerization initiator (Asahi Denka Kogyo Co., Ltd., aromatic sulfonium salt-based cationic polymerization catalyst, trade name: SP170, liquid at normal temperature, catalyst: solvent = weight ratio 50:50) 1 part by weight (catalyst amount) is charged with raw materials other than the cationic polymerization initiator into a jacketed planetary mixer capable of circulating heated oil. After mixing at 180 ° C. for 30 minutes at 30 rpm, and covering with an aluminum foil, the above cationic polymerization initiator was added and mixed at 150 ° C. for 30 minutes at 30 rpm to obtain a hot melt adhesive.

(Reference Examples 2 to 4)
As shown in Table 1 below, a reactive hot melt adhesive was obtained in the same manner as in Reference Example 1, except that the blending ratio of the epoxy-modified block copolymer and the type of the epoxy resin used were changed. .

( Reference Example 5 )
70 parts by weight of epoxy resin 4 and 30 parts by weight of epoxy resin 5 were put into a planetary mixer with jacket that can circulate heated oil, mixed at 30 ° C. for 30 minutes at 120 ° C., and then the whole with aluminum foil Covering, 1 part by weight (catalyst amount) of the cationic polymerization initiator used in Reference Example 1 was added and mixed at 120 ° C. at 30 rpm for 10 minutes to obtain a reactive hot melt adhesive.

( Reference Example 6, Examples 1-2 )
A reactive hot melt adhesive was obtained in the same manner as in Reference Example 5 except that the type and blending ratio of the epoxy resin were changed as shown in Table 2 below.

( Reference Example 7 )
Planetar with jacket that can circulate heated oil with 70 parts by weight of Poval (product name: UMR-10L, trade name: UMR-10L, degree of saponification 35.3%, degree of polymerization 250) and 30 parts by weight of epoxy resin 7 The mixture was introduced into a Lee mixer and mixed at 120 ° C. at 30 rpm for 30 minutes, and then the whole was covered with aluminum foil, and 1 part by weight (catalyst amount) of the cationic polymerization initiator used in Reference Example 1 was introduced at 120 ° C. A reactive hot melt adhesive was obtained by mixing at 30 rpm for 10 minutes.

( Reference Examples 8 to 10 )
A reactive hot melt adhesive was obtained in the same manner as in Reference Example 7 except that the blending ratio of poval and the kind and blending ratio of the epoxy resin were changed as shown in Table 3 below.

( Reference Example 11 )
100 parts by weight of copolymer 1 as an ethylene-glycidyl (meth) acrylate copolymer was weighed out and placed in a jacketed planetary mixer capable of circulating heated oil, and mixed at 180 ° C. and 30 rpm for 30 minutes. The whole was covered with aluminum foil, 1 part by weight (catalyst amount) of the cationic polymerization initiator used in Reference Example 1 was charged, and mixed at 30 rpm for 10 minutes at a temperature of 150 ° C. to obtain a reactive hot melt adhesive.

( Reference Examples 12-15 )
The reaction was performed in the same manner as in Reference Example 1 except that copolymer 1 was replaced by 100 parts by weight and copolymer 1 or 2 and olefin resin 1 or 2 were used as shown in Table 4 below. Hot melt adhesive was obtained.

The olefin resins 1 and 2 are as follows.
Olefin resin 1: manufactured by Mitsubishi Chemical Corporation, polyolefin polyol, trade name: Polytail H, melting point 60-70 ° C., hydroxyl value 45.2 KOH mg / g.
Olefin resin 2 ... manufactured by Nippon Soda Co., Ltd., hydrogenated polybutadiene resin, trade name: GI-1000, liquid at room temperature, hydroxyl value 65.8 KOHmg / g.

(Comparative Example 1)
As Comparative Example 1, Sekisui Chemical Co., Ltd., reactive hot melt adhesive, trade name: Esdyne 9613 (moisture reaction hardening type, softening point 68 ° C.) was prepared.

(Evaluation of Examples and Comparative Examples)
Using the reactive hot melt adhesive compositions of Reference Examples 1 to 15 , Examples 1 to 2 and Comparative Example 1, initial adhesive strength and heat resistant adhesive strength were evaluated in the following manner, and the results are shown in Tables 1 to 4 It was.

(1) Initial adhesive strength: Using a roll coater set at 150 ° C. (Comparative Example 1 is 120 ° C.), the reactive hot melt adhesive composition was applied to a SPCC dull steel plate of 25 mm × 125 mm × 1.6 mm, 50 It was applied at a thickness of ˜150 μm. Thereafter, an active energy ray with a wavelength of 365 nm is applied to the applied reactive hot melt adhesive composition for 30 seconds using an ORK Seisakusho high pressure mercury lamp “Jetlight JL2300” so that the illuminance is 25 mW / cm ^2. irradiated, further superimposed No. 9 cotton canvas 25 mm × 125 mm, 2 min at 120 ° C., was heat-pressed under a pressure of 0.5 kg / cm ^2, 2 min at 23 ℃, 0.5kg / cm ² The pressure test was applied and cooled, and the adhesion test piece of the conditions without curing shown in Table 1 was produced. Immediately after producing this adhesion test piece, a floating roller method peel test was performed at 23 ° C. according to JIS K6854, and the peel strength was measured to obtain the initial bond strength without curing.

In the same manner as described above, except that the reactive hot melt adhesive composition was applied to the SPCC dull steel plate and then cured for 7 days at 23 ° C. and a relative humidity of 60%. Pieces were prepared and the initial bond strength in the case of post-curing conditions was measured.

(2) Heat-resistant adhesive strength (1) After being prepared in the same manner as the adhesive test piece prepared for the evaluation of initial adhesive strength, 23 ° C., relative humidity 30%, 3 days or 23 ° C., relative humidity 95% shown in Table 1 After curing under two conditions for 3 days, a floating roller method peel test was performed at 100 ° C. according to JIS K6854, the peel strength was measured, and the heat resistant adhesive strength was obtained.

As is clear from Tables 1 to 4, in Reference Examples 1 to 15 and Examples 1 to 2 , sufficient adhesive strength was obtained even in the case of no curing and in the case of curing at 23 ° C. and RH 60% for 7 days. Indicated. In addition, in the heat resistant adhesive strength evaluation, high adhesive strength was exhibited regardless of the humidity level.

On the other hand, in the reactive hot melt adhesive of Comparative Example 1, in the initial adhesive strength evaluation, when it was bonded after being cured at 23 ° C. and a relative humidity of 60% for 7 days, the curing had already progressed. Adhesive strength was not expressed. Even in the evaluation of heat-resistant adhesive strength, when it was cured under conditions where the relative humidity was as low as 30%, sufficient adhesive strength could not be obtained.

According to the present invention, the adherends can be reliably bonded to each other and heat resistance is exhibited after bonding even when the application time after application of the adhesive to the bonding is sufficiently long. It is possible to provide a reactive hot melt adhesive and a bonding method using the reactive hot melt adhesive that are short in time and are not greatly affected by the season and weather.

Claims (3)

Cationic polymerization for polymerizing and curing a cation-polymerizable compound by irradiation with active energy rays, a bisphenol-type epoxy resin having a softening point of 50 to 180 ° C. by ring-and-ball measurement method , an epoxy compound other than the bisphenol-type epoxy resin A reactive hot melt adhesive composition comprising an initiator,
The reactive hot melt adhesive composition, wherein the epoxy compound is a terminal epoxidized polyether polyol . The reactive hot melt adhesive composition according to claim 1, wherein the cationic polymerization initiator is at least one selected from the group consisting of an aromatic iodonium salt, an aromatic sulfonium salt, and a metallocene salt. Claim 1 or by heating and melting the reactive hot melt adhesive composition wherein, thereafter was coated on one or both in a molten state of the adherend, the applied reactive hot-melt adhesive activity composition An adhesion method characterized by adhering adherends to each other after irradiation with energy rays and pressure bonding at room temperature or under heating.