CN108431157B - Bonding method using photocurable adhesive - Google Patents

Abstract

The invention provides a photocurable adhesive, an adhesive-containing product, a bonding method and a product manufacturing method. The photocurable adhesive contains: (A) a monoacrylate represented by general formula (1) that suppresses oxygen inhibition, an organic compound selected from the group consisting of (B1) a monofunctional (meth) acrylate and (B2) a liquid organic polymer, and (C) a photoinitiator. (in the general formula (1), R¹Represents a hydrogen atom or a methyl group, R²To R⁶Each independently is a hydrogen atom or a substituent. )

Description

Bonding method using photocurable adhesive

Technical Field

The present invention relates to an adhesion method using a photocurable adhesive that rapidly undergoes photocuring even in air.

Background

Patent document 1 discloses a method in which a photocurable composition containing a photopolymerizable acrylate is applied to one adherend, and then irradiated with ultraviolet rays to polymerize the acrylate to increase the viscosity (referred to as B-staging, which is considered to impart tackiness), and in this state, another adherend is adhesively fixed. As a specific example, manufacturing of a Radio Frequency Identification (RFID) tag is shown in which an antenna member is used as one adherend and an IC chip is used as another adherend. In patent document 1, a moisture-curable resin is further used in the photocurable composition to reliably perform adhesion.

It is considered that the method of applying the photocurable composition containing the photopolymerizable acrylate to one adherend, polymerizing the acrylate by irradiation with light to impart tackiness, and then bonding the other adherend is useful particularly in the production of electronic devices. This is because, with such a method, peeling is easily performed for the purpose of aligning the temporarily bonded adherends, for example. This is because, although the same method can be carried out using an adhesive sheet or an adhesive tape, it is often difficult to place the adhesive sheet or the adhesive tape in a predetermined shape at a predetermined position, and the uncured photocurable composition is relatively easily applied to a predetermined position by the above-mentioned bonding method.

However, although acrylate has photopolymerization properties, it is known that polymerization is inhibited in the presence of oxygen such as in air, and therefore, polymerization does not proceed, or long-term irradiation or strong light irradiation is required. Actually, in example 1 of patent document 1, phenoxyethyl acrylate is used as the acrylic acid ester, but a time of 1 hour or less is necessary for photopolymerization. In the manufacture of electronic devices, it is considered that the photopolymerization is preferably performed for a time of a second unit from the viewpoint of productivity. In order to solve the problem of oxygen inhibition, light irradiation may be performed under a nitrogen atmosphere or may be performed using a transparent coating film to block oxygen, but equipment is additionally necessary.

Documents of the prior art

Patent document

Patent document 1: japanese patent application laid-open No. 2009-530441

Patent document 2: international publication WO2013-161812

Disclosure of Invention

Problems to be solved by the invention

An object of the present invention is to provide a bonding method for bonding a plurality of adherends using a photocurable adhesive containing an acrylate, wherein photopolymerization of the acrylate is rapidly performed even in the presence of oxygen and long-term light irradiation or oxygen blocking equipment is not required.

Means for solving the problems

The present inventors have found that when an acrylate having a hydroxyl group disclosed in patent document 2 is used as the acrylate, photopolymerization of the acrylate proceeds rapidly even in the presence of oxygen, and finally the present invention has been completed. In patent document 2, as described in, for example, examples of paragraph 0071 of patent document 2, an ultraviolet-curable adhesive composition is coated on a release-treated polyester film, and is pre-cured by UV irradiation, and then a cured product coated surface is bonded to the release-treated polyester film to block air, and is cured by UV irradiation to obtain an adhesive layer. That is, the adhesive layer is obtained by pre-curing, not by increasing the viscosity of the surface of the composition but by increasing the viscosity of the inside, bonding the composition to a release-treated polyester film in this state to block air, and curing the composition again by light irradiation. Therefore, patent document 2 neither describes nor discloses a point of view of oxygen inhibition required for the adhesive composition in field work requiring work in air without using release paper. Therefore, the object of the present invention cannot be achieved. That is, the present invention is the following bonding method.

The present invention provides a bonding method for bonding a plurality of adherends, the bonding method including the steps of:

a coating step of applying a photocurable adhesive exhibiting adhesiveness by light irradiation to at least one adherend,

a light irradiation step of irradiating light to the photocurable adhesive applied to one adherend, and

a bonding step of bonding a photo-curable adhesive applied to one adherend and irradiated with light to another adherend, in which a protective sheet having a bonding surface removed as another adherend,

the photocurable adhesive contains:

(A) a monoacrylate represented by the following general formula (1),

at least one organic compound selected from the group consisting of (B1) monofunctional (meth) acrylates and (B2) liquid organic polymers, and

(C) a photoinitiator.

[ chemical formula 1]

In the general formula (1), R¹Represents a hydrogen atom or a methyl group, R²To R⁶Each independently is a hydrogen atom or a substituent.

In the above bonding method, the photocurable adhesive may further contain (D) a tackifier resin (tack resin).

In the above bonding method, the photocurable adhesive may further contain (E) a compound containing 2 or more photoradically polymerizable vinyl groups.

In the above bonding method, (E) the compound containing 2 or more photo radical polymerizable vinyl groups may be a polymer.

In the above bonding method, (B2) the liquid organic polymer may be a polymer having a crosslinkable silicone group.

In order to achieve the above object, the present invention provides an adhesive body produced by the adhesive method according to any one of the above aspects.

In order to achieve the above object, the present invention provides a photocurable adhesive for field construction, which exhibits adhesiveness when irradiated with light, the photocurable adhesive for field construction comprising:

(A) a monoacrylate represented by the general formula (1),

(B1) at least one organic compound selected from the group consisting of monofunctional (meth) acrylates and (B2) liquid organic polymers, and

(C) a photoinitiator.

[ chemical formula 2]

In the general formula (1), R¹Represents a hydrogen atom or a methyl group, R²To R⁶Each independently is a hydrogen atom or a substituent.

Further, patent document 2 discloses an ultraviolet-curable adhesive composition containing a predetermined polyfunctional urethane (meth) acrylate oligomer, a tackifier (tagrifier), a monofunctional epoxy ester (meth) acrylate, and a photopolymerization initiator, but the ultraviolet-curable adhesive composition according to patent document 2 is different from the present invention and is not used for field application but is used for a purpose different from the present invention.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the bonding method of the present invention, there can be provided a bonding method for bonding a plurality of adherends using a photocurable adhesive containing an acrylate, in which photopolymerization of the acrylate is rapidly performed even in the presence of oxygen, and long-term light irradiation or oxygen cut-off equipment is not required.

Drawings

Fig. 1 is a schematic diagram showing a printed circuit board and an LED chip used in an LED chip bonding test.

Fig. 2 is a schematic view showing a process of bonding an LED chip to a printed board.

Detailed Description

The bonding method of the present invention is not a method for producing an adhesive product such as an adhesive sheet or an adhesive tape, but a method comprising: the material that becomes an adhesive by light irradiation is directly applied to an adherend to produce an adhesive on the adherend, and another adherend is bonded thereto. That is, in the bonding method of the present invention, the photocurable adhesive is used without being molded into a body such as an adhesive tape, but is directly applied to one adherend and used for bonding to another adherend (that is, the other adherend is not a film such as a release liner (liner), but is actually bonded to the adherend of the one adherend).

The bonding method of the present invention can be used for bonding electronic and electric components, and is particularly suitable for bonding electronic components. Here, in the present invention, "for field construction" means that the photocurable adhesive is used in order to be bonded as it is in a field where electronic components and the like are manufactured. That is, the present invention does not refer to an application in which an adhesive is processed into a shape such as a tape to be molded, and the molded article is used in a place different from the processing place; the term "pressure-sensitive adhesive" refers to an application in which the photocurable pressure-sensitive adhesive of the present invention is applied as it is to one adherend and the one adherend is attached to another adherend in this state (or on the spot).

The photocurable adhesive of the present invention is a photocurable adhesive which exhibits adhesion rapidly by irradiation with light such as active energy rays. That is, the photocurable adhesive contains: (A) a compound capable of exhibiting cohesive force (cohesive force) and inhibiting oxygen inhibition by oxygen in the environment, (B) a compound capable of exhibiting flexibility, and (C) a compound capable of generating radicals by irradiation with light. Specifically, the photocurable adhesive of the present invention comprises: (A) a monoacrylate represented by the following general formula (1), at least one organic compound selected from the group consisting of (B1) monofunctional (meth) acrylate as the B component and (B2) liquid organic polymer as the B component, and (C) a photoinitiator. The photocurable adhesive may further contain (D) a tackifier resin. The photocurable adhesive may further contain (E) a polyfunctional monomer containing a photoradically polymerizable vinyl group and/or (E) a polyfunctional polymer containing a photoradically polymerizable vinyl group.

[ chemical formula 3]

In the general formula (1), R¹Represents a hydrogen atom (-H) or a methyl group (-CH)₃)，R²To R⁶Each independently is a hydrogen atom or a substituent. Examples of the substituent include a nitro group, a cyano group, a hydroxyl group, a halogen atom, an acetyl group, a carbonyl group, a substituted or unsubstituted allyl group, a substituted or unsubstituted alkyl group (preferably an alkyl group having 1 to 5 carbon atoms), a substituted or unsubstituted alkoxy group (preferably an alkoxy group having 1 to 5 carbon atoms), an unsubstituted or substituted aryl group, an unsubstituted or substituted aryloxy group, a heterocyclic structure-containing group, a group having a plurality of rings, or a combination thereof. R²～R⁶Any of which may be bonded to each other to form a ring structure. At a position selected from R²～R⁶When at least 2 groups in the group are bonded to each other to form a cyclic structure, the following structure may be formed: a structure obtained by condensing a plurality of benzene rings, a structure obtained by condensing a benzene ring with a heterocyclic ring or a non-aromatic ring, a ring to which a functional group such as a carbonyl group is bonded, or the like. Among these substituents, preferred is a substituted or unsubstituted alkyl group, and more preferred is a substituted or unsubstituted alkyl groupA substituted alkyl group having 1 to 5 carbon atoms.

(component A: monoacrylate)

The component a contained in the photocurable adhesive is a compound having a plurality of electron-withdrawing groups, and is a compound that easily generates active radicals in a portion sandwiched between the plurality of electron-withdrawing groups. The present inventors speculate that the compound having such a structure can suppress polymerization inhibition by oxygen, and have studied the characteristics of a photocurable adhesive using various compounds, and as a result, have found that the component a of the photocurable adhesive of the present invention is preferable. That is, it was found that the component a is preferably a monofunctional compound containing: in clamping on a plurality of-CH₂Radical (in particular 2-CH)₂Group), and electron-withdrawing groups located at both ends of the molecule. Specifically, the component A is a monoacrylate represented by the general formula (1). Specific examples of the component A include 2-hydroxy-3-phenoxypropyl acrylate and the like.

Here, the effects of the present invention cannot be obtained with respect to monoacrylates having a hydroxyl group (e.g., 4-hydroxybutyl acrylate, 2-hydroxybutyl acrylate, etc.) other than the monoacrylate represented by general formula (1).

In view of the following points, it is preferable that the component A is not polyfunctional, and a monoacrylate is preferably used. This view is: the pressure-sensitive adhesive obtained from a photocurable pressure-sensitive adhesive and a cured product obtained by post-curing the pressure-sensitive adhesive are used in view of providing a cured product having more flexibility than a cured product obtained from epoxy acrylate, acrylamide, or the like, and/or in view of using a compound having a relatively low glass transition temperature than the glass transition temperature of epoxy acrylate, acrylamide, or the like.

Here, the mechanism of suppressing polymerization inhibition by oxygen is assumed to be the following mechanism. That is, polymerization inhibition by oxygen is caused in radical polymerization, and the reaction rate of the monomer is lowered. In particular, a reduction in the reaction rate occurs in the surface layer in contact with air. Regarding oxygen inhibition, polymerization reaction is stopped due to low polymerization ability of a peroxy radical generated by capturing an initial radical generated from a photoinitiator or a polymerization terminal radical generated during polymerization of a monomer by oxygen, thus causing. Here, it is considered that when a monoacrylate having a component a functioning as a chain transfer agent is present in the system, a peroxygenated radical having a hydrogen abstraction ability abstracts hydrogen from the monoacrylate, and thus a carbon radical of a newly generated secondary hydroxyl group initiates polymerization. It is also considered that the α carbon radical of the generated secondary hydroxyl group also captures oxygen, and therefore, the effect of reducing the oxygen concentration in the system is obtained. From these mechanisms, inhibition of oxygen inhibition is presumed.

When a crosslinkable silicon group-containing monoacrylate is used as the monoacrylate, the photocurable adhesive exhibits adhesiveness by irradiation with light, and is then easily post-cured (adhesive) with time. The liquid organic polymer is converted into a monoacrylate containing a crosslinkable silicon group by introducing a crosslinkable silicon group as a substituent. Specific structure of the crosslinkable silicon group includes trialkoxysilyl [ -Si (OR) such as trimethoxysilyl group₃]Dialkoxysilyl [ -Si (CH) such as methyldimethoxysilyl₃)(OR)₂]From the viewpoint of high reactivity, trialkoxysilyl [ -Si (OR)₃]Is preferred, more preferably trimethoxysilyl. Here, R is an alkyl group such as a methyl group or an ethyl group.

(component B1: monofunctional (meth) acrylate)

The component B1 is a compound that allows the photocurable adhesive to exhibit flexibility. The monofunctional (meth) acrylate is a compound having 1 (meth) acryloyloxy group, and any of a monomer (hereinafter, also referred to as a monomer) and a polymer can be used, and a monomer having a (meth) acryloyloxy group is preferable from the viewpoint of viscosity. Further, a polymer having a (meth) acryloyloxy group is preferable from the viewpoint of physical properties of a cured product. As to the monomer having 1 (meth) acryloyloxy group, in the case of a compound having 1 (meth) acryloyloxy group,there is no particular limitation. For example, monofunctional (meth) acrylate monomers are listed. The (meth) acrylate group is preferably an acrylate group from the viewpoint of reactivity. In addition, regarding the monofunctional (meth) acrylate monomer, the T of a homopolymer obtained from the monofunctional (meth) acrylate monomer is considered to be excellent in adhesiveness of the photocurable adhesive_gPreferably 40 ℃ or lower, more preferably 10 ℃ or lower, and most preferably 0 ℃ or lower. The component B1 is preferably in a liquid state from the viewpoint of ease of mixing.

As the monofunctional (meth) acrylate monomer, for example, there are enumerated

CH₂＝CR^αCOO(C_mH_2mO)_nR^β···(2)

(in the general formula (2), R^αis-H or-CH₃M is an integer of 2 to 4, n is an integer of 1 to 20, R^βrepresents-H or unsubstituted or substituted alkyl, unsubstituted or substituted phenyl). Specifically, as the monofunctional (meth) acrylate monomer, there are listed: in the general formula (2) R^βA compound represented by H, an aliphatic epoxy (meth) acrylate, or a hydroxyl group-containing (meth) acrylate; in the general formula (2) R^β(meth) acrylates having an alkoxy group such as unsubstituted or substituted alkyl compounds; in the general formula (2) R^βAromatic (meth) acrylates such as unsubstituted or substituted phenyl compounds and aryl (meth) acrylates; a long-chain hydrocarbon (meth) acrylate having 8 to 20 carbon atoms; an alicyclic (meth) acrylate; a (meth) acrylate having a heterocyclic group; (meth) acrylate having a carboxyimide group; (meth) acrylates having crosslinkable silicon groups, and the like. From the viewpoint of excellent adhesion of the photocurable adhesive, a long-chain hydrocarbon (meth) acrylate having 8 to 20 carbon atoms and/or a compound of the general formula (2) is preferred, a long-chain hydrocarbon (meth) acrylate having 8 to 20 carbon atoms, a (meth) acrylate having a hydroxyl group, and a (meth) acrylate having an alkoxy group are more preferred, and a long-chain hydrocarbon (meth) acrylate having 8 to 20 carbon atoms is most preferred.

Specific examples of the monofunctional (meth) acrylate are as follows. First, as the (meth) acrylate having a hydroxyl group, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hexaethyleneglycol mono (meth) acrylate, octapropyleneglycol mono (meth) acrylate, 2-hydroxy-3-octyloxypropyl acrylate, and the like are exemplified. Examples of the (meth) acrylate having an alkoxy group include methoxytriethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, and dicyclopentenyloxyethyl (meth) acrylate. As the aromatic (meth) acrylate, phenoxyethyl (meth) acrylate, nonylphenoxyethyl (meth) acrylate, benzyl (meth) acrylate and the like are exemplified. The long-chain hydrocarbon (meth) acrylate having 8 to 20 carbon atoms includes 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, and isostearyl (meth) acrylate, and from the viewpoint of ease of acquisition, a long-chain hydrocarbon (meth) acrylate having 8 to 18 carbon atoms is preferable. Examples of the alicyclic (meth) acrylate include cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and isobornyl (meth) acrylate. Examples of the (meth) acrylate having a heterocyclic group include tetrahydrofurfuryl (meth) acrylate and the like. Further, N- (meth) acryloyloxyethylhexahydrophthalimide and the like are exemplified. Examples of the (meth) acrylate having a crosslinkable silicon group include 3- (trimethoxysilyl) propyl (meth) acrylate.

In addition, as for the polymer having 1 (meth) acryloyloxy group, a polymer having 1 (meth) acryloyloxy group may be used. Examples thereof include acrylic polymers having an acrylic polymer having 1 (meth) acryloyloxy group as a skeleton, urethane (meth) acrylate polymers, polyester (meth) acrylate polymers, polyether (meth) acrylate polymers, and epoxy (meth) acrylate polymers.

(component B2: liquid organic Polymer)

As the main chain skeleton of the liquid organic polymer, specific examples are: polyoxyalkylene polymers such as polyoxypropylene, polyoxytetramethylene, and polyoxyethylene-polyoxypropylene copolymers; hydrocarbon polymers such as ethylene-propylene copolymers, polyisobutylene, polyisoprene, polybutadiene, and hydrogenated polyolefin polymers obtained by hydrogenating these polyolefin polymers; polyester polymers obtained by condensation of a dibasic acid such as adipic acid with a diol or ring-opening polymerization of lactones; a (meth) acrylate polymer obtained by radical polymerization of monomers such as ethyl (meth) acrylate and butyl (meth) acrylate; vinyl polymers obtained by radical polymerization of monomers such as (meth) acrylate monomers, vinyl acetate, acrylonitrile, and styrene; a graft polymer obtained by polymerizing a vinyl monomer in an organic polymer; a polysulfide polymer; a polyamide-based polymer; a polycarbonate-series polymer; diallyl phthalate polymers, and the like. These skeletons may also contain 2 or more kinds of them in blocks or randomly.

Further, saturated hydrocarbon polymers such as polyisobutylene, hydrogenated polyisoprene, and hydrogenated polybutadiene, polyoxyalkylene polymers, and (meth) acrylate polymers are preferable because the glass transition temperature is relatively low, and the resulting photocurable adhesive is excellent in cold resistance. The polyoxyalkylene polymer and the (meth) acrylate polymer are particularly preferable because they have high moisture permeability and excellent deep curing properties when they are produced as a one-pack composition.

The liquid organic polymer may be linear or branched, and has a number average molecular weight of about 500 to 100,000, more preferably 1,000 to 50,000, and particularly preferably 3,000 to 30,000 in terms of polystyrene in GPC. When the number average molecular weight is less than 500, there is a tendency that it is inconvenient in terms of the elongation characteristics of the photocurable adhesive; when the viscosity exceeds 100,000, the viscosity becomes high, and thus the workability tends to be inconvenient.

(polyoxyalkylene polymer)

The polyoxyalkylene polymer is a polymer having a repeating unit represented by the general formula (3).

-R⁷-O-···(3)

In the general formula (3), R⁷Is a linear or branched alkylene group having 1 to 14 carbon atoms, preferably a linear or branched alkylene group having 1 to 14 carbon atoms, and more preferably a linear or branched alkylene group having 2 to 4 carbon atoms.

As specific examples of the repeating unit represented by the general formula (3), there may be mentioned-CH₂CH₂O-、-CH₂CH(CH₃)O-、-CH₂CH₂CH₂CH₂O-, etc. The main chain skeleton of the polyoxyalkylene polymer may be composed of only 1 kind of repeating unit, or may be composed of 2 or more kinds of repeating units.

The method for synthesizing the polyoxyalkylene polymer includes, for example, polymerization using an alkali catalyst such as KOH and polymerization using a double metal cyanide complex catalyst, but is not particularly limited. According to the polymerization method based on the double metal cyanide complex catalyst, a polyoxyalkylene polymer having a high molecular weight and a narrow molecular weight distribution, wherein the number average molecular weight is 6,000 or more and the Mw/Mn is 1.6 or less, can be obtained.

The main chain skeleton of the polyoxyalkylene polymer may contain other components such as urethane bond components. As the urethane bond component, for example, there are listed: and a component obtained by reacting an aromatic polyisocyanate such as toluene (tolylene) diisocyanate or diphenylmethane diisocyanate, or an aliphatic polyisocyanate such as isophorone diisocyanate with a polyoxyalkylene polymer having a hydroxyl group.

(saturated Hydrocarbon Polymer)

The saturated hydrocarbon polymer is a polymer substantially free of carbon-carbon unsaturated bonds other than aromatic rings. The polymer forming the skeleton thereof can be obtained by the following method: (1) a method of polymerizing an olefin compound having 2 to 6 carbon atoms such as ethylene, propylene, 1-butene, isobutylene, or the like as a main monomer, or (2) a method of homopolymerizing a diene compound such as butadiene, isoprene, or the like, or copolymerizing a diene compound and an olefin compound, followed by hydrogenation. The isobutylene polymer or hydrogenated polybutadiene polymer is preferably, particularly preferably, an isobutylene polymer because functional groups can be easily introduced into the terminal groups, the molecular weight can be easily controlled, and the number of terminal functional groups can be increased. When the main chain skeleton is a saturated hydrocarbon polymer, the resin composition is excellent in heat resistance, weather resistance, durability, and moisture barrier properties.

The isobutylene polymer may be a copolymer of all monomer units formed of isobutylene units and other monomers. From the viewpoint of rubber properties, a polymer containing 50 mass% or more of repeating units derived from isobutylene is preferable, a polymer containing 80 mass% or more of repeating units derived from isobutylene is more preferable, and a polymer containing 90 to 99 mass% of repeating units derived from isobutylene is particularly preferable.

((meth) acrylate-based Polymer)

As the (meth) acrylate monomer constituting the main chain of the (meth) acrylate polymer, various monomers can be used. Examples thereof include alkyl (meth) acrylate monomers such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and stearyl (meth) acrylate; an alicyclic (meth) acrylate monomer; an aromatic (meth) acrylate monomer; a (meth) acrylate monomer such as 2-methoxyethyl (meth) acrylate; silyl group-containing (meth) acrylate monomers such as γ - (methacryloyloxy) propyltrimethoxysilane and γ - (methacryloyloxy) propyldimethoxymethylsilane; derivatives of (meth) acrylic acid; fluorine-containing (meth) acrylate monomers, and the like.

In the case of the (meth) acrylate polymer, the following vinyl monomers may be copolymerized together with the (meth) acrylate monomer. Examples of the vinyl monomer include styrene, maleic anhydride, and vinyl acetate.

These may be used alone or in combination. Further, by using a silyl group-containing (meth) acrylate monomer in combination, the number of silicon groups in the (meth) acrylate polymer (a) can be controlled. Since the adhesiveness is good, a methacrylate ester polymer containing a methacrylate monomer is particularly preferable. In addition, when the viscosity is reduced, flexibility is imparted, and adhesiveness is imparted, it is preferable to use an acrylate monomer as appropriate. The (meth) acrylic acid means acrylic acid and/or methacrylic acid.

The method for producing the (meth) acrylate polymer is not particularly limited, and for example, a radical polymerization method using a radical polymerization reaction can be used. As the radical polymerization method, there are listed: a radical polymerization method (radical polymerization method) in which a predetermined monomer unit is copolymerized using a polymerization initiator, or a controlled radical polymerization method in which a reactive silyl group can be introduced at a controlled position such as a terminal. However, a polymer obtained by a radical polymerization method using an azo compound, a peroxide or the like as a polymerization initiator generally has a molecular weight distribution of 2 or more, and has a high viscosity. Therefore, in order to obtain a (meth) acrylate polymer having a narrow molecular weight distribution, a low viscosity, and a high proportion of crosslinkable functional groups at the molecular chain terminals, it is preferable to use a controlled radical polymerization method.

The controlled Radical Polymerization method includes a Radical Polymerization method or a Living Radical Polymerization method using a chain Transfer agent having a specific functional group, and more preferably a Living Radical Polymerization method such as a Reversible Addition-Fragmentation chain Transfer (RAFT) Polymerization method or a Radical Polymerization method using a Transition Metal complex (Transition-Metal-medical Polymerization). In addition, it is also preferable that: a reaction using a thiol compound having a reactive silyl group, and a metallocene compound.

The (meth) acrylate-based polymer having a crosslinkable silicon group may be used alone, or 2 or more kinds may be used in combination.

These liquid organic polymers may be used alone, or 2 or more kinds may be used in combination. Specifically, an organic polymer obtained by blending 2 or more selected from the group consisting of a polyoxyalkylene polymer, a saturated hydrocarbon polymer, and a (meth) acrylate polymer may also be used.

Various methods are exemplified as a method for producing an organic polymer obtained by blending a polyoxyalkylene polymer and a (meth) acrylate polymer. For example, there is a method of blending a polyoxyalkylene polymer into a copolymer having a molecular chain substantially containing a (meth) acrylate monomer unit represented by the general formula (4) and a (meth) acrylate monomer unit represented by the general formula (5)

-CH₂-C(R⁸)(COOR⁹)-···(4)

(in the formula, R⁸Is a hydrogen atom or a methyl group, R⁹Represents an alkyl group having 1 to 5 carbon atoms)

-CH₂-C(R⁸)(COOR¹⁰)-···(5)

(in the formula, R⁸Same as above, R¹⁰Represents an alkyl group having 6 or more carbon atoms).

R as formula (4)⁹Examples thereof include alkyl groups having 1 to 5 carbon atoms, preferably 1 to 4 carbon atoms, and more preferably 1 to 2 carbon atoms such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups. And R is⁹The alkyl group(s) may be used alone or in combination of 2 or more.

R as formula (5)¹⁰Examples thereof include a long-chain alkyl group having 6 or more carbon atoms, usually 7 to 30 carbon atoms, and preferably 8 to 20 carbon atoms, such as a 2-ethylhexyl group, a lauryl group, and a stearyl group. And R is¹⁰Alkyl of (2) with R⁹The same applies to the case of (2) or more.

The molecular chain of the (meth) acrylate copolymer substantially contains monomer units of the formulae (4) and (5). Here, "substantially" means that the total of the monomer units of the formulae (4) and (5) present in the copolymer exceeds 50% by mass. The total of the monomer units of the formulae (4) and (5) is preferably 70% by mass or more. The ratio of the monomer unit of formula (4) to the monomer unit of formula (5) is preferably 95:5 to 40:60, and more preferably 90:10 to 60:40, in terms of mass ratio.

The number average molecular weight of the (meth) acrylate polymer is preferably 600 to 10,000, more preferably 600 to 5,000, and still more preferably 1,000 to 4,500. When the number average molecular weight is in this range, the compatibility with the polyoxyalkylene polymer is improved. The (meth) acrylate-based polymer may be used alone, or 2 or more kinds thereof may be used in combination. The blending ratio of the polyoxyalkylene polymer and the (meth) acrylate polymer is not particularly limited, but the (meth) acrylate polymer is preferably within a range of 10 to 60 parts by mass, more preferably within a range of 20 to 50 parts by mass, and even more preferably within a range of 25 to 45 parts by mass, based on 100 parts by mass of the total of the (meth) acrylate polymer and the polyoxyalkylene polymer. When the amount of the (meth) acrylate polymer is more than 60 parts by mass, the viscosity becomes high, and the workability is deteriorated, which is not preferable.

Further, as to a method for producing an organic polymer obtained by blending a (meth) acrylate copolymer, in addition to the above, there can be used: a method for polymerizing a (meth) acrylate monomer in the presence of an organic polymer.

When 2 or more kinds of polymers are blended and used, the amount of the saturated hydrocarbon polymer and/or the (meth) acrylate polymer is preferably 10 to 200 parts by mass, more preferably 20 to 80 parts by mass, based on 100 parts by mass of the polyoxyalkylene polymer.

Even when 2 or more organic polymers are used, even when a solid organic polymer is contained, if the organic polymer is an organic polymer that becomes liquid when the solid organic polymer is mixed with another organic polymer (that is, the solid organic polymer is dissolved in another organic polymer and becomes liquid), the component B2 of the present invention can be used. Further, the liquid organic polymer is preferably in a liquid state at 20 ℃, more preferably in a liquid state at 0 ℃, and still more preferably in a liquid state at-10 ℃ from the viewpoint of ensuring ease of handling when blended with other components.

In the case where a liquid organic polymer containing a crosslinkable silyl group is used as the liquid organic polymer, the photocurable adhesive exhibits adhesiveness by light irradiation, and is then easily post-cured (adhesive) with time. The liquid organic polymer is prepared by introducing a crosslinkable silyl group into a liquid organic polymer containing a crosslinkable silyl group.

(crosslinkable silicon group-containing liquid organic Polymer)

As the crosslinkable silyl group of the crosslinkable silyl group-containing liquid organic polymer, for example, a group represented by the general formula (6) is preferable.

[ chemical formula 4]

In the formula (6), R^γRepresents an organic group. And R is^γPreferably a hydrocarbon group having 1 to 20 carbon atoms. In which R is^γMethyl is particularly preferred. R^γMay have a substituent. There being more than 2R^γIn the case of (2), a plurality of R^γMay be the same or different. W represents a hydroxyl group or a hydrolyzable group, and when 2 or more W's are present, the plural W's may be the same or different. a is any one of integers of 0, 1,2 or 3. In order to obtain a photocurable adhesive having a sufficient curing speed in consideration of curability, a in formula (6) is preferably 2 or more, and more preferably 3.

The hydrolyzable group and/or hydroxyl group may be bonded to 1 silicon atom in the range of 1 to 3. When 2 or more hydrolyzable groups and/or hydroxyl groups are bonded to the crosslinkable silicon group, they may be the same or different.

The hydrolyzable group represented by W is not particularly limited as long as it is a group other than F atom. Examples thereof include an alkoxy group, an acyloxy group, a ketoximate group, an aminooxy group, and an alkenyloxy group. The alkoxy group is preferable in terms of mild hydrolyzability and easy handling. Among the alkoxy groups, one of the alkoxy groups having a small carbon number has high reactivity, and the reactivity decreases as the carbon number increases, as in the order of methoxy group > ethoxy group > propoxy group. May be selected according to purpose and/or use, but a methoxy group and/or an ethoxy group is generally used.

Specific structures of the crosslinkable silicon group include trialkoxysilyl [ -Si (OR) such as trimethoxysilyl group and triethoxysilyl group₃]Dialkoxysilyl [ -SiR ] such as methyldimethoxysilyl group and methyldiethoxysilyl group¹(OR)₂]From the viewpoint of high reactivity, trialkoxysilyl [ -Si (OR)₃]Is preferred, more preferably trimethoxysilyl. Here, R is an alkyl group such as a methyl group or an ethyl group.

The number of crosslinkable silicon groups may be 1 or 2 or more. The crosslinkable silicon groups may be present in the main chain or in the side chains or in either.

The compounding ratio of the monofunctional (meth) acrylate and the liquid organic polymer is preferably 10 to 80 parts by mass, more preferably 20 to 70 parts by mass, and most preferably 30 to 60 parts by mass, based on 100 parts by mass of the component a and the component B1 and/or the component B2 (when both the component B1 and the component B2 are used, the total of the component a, the component B1, and the component B2 [ hereinafter, also referred to as 100 parts by mass of the liquid AB component ]). The compounding ratio of the monofunctional (meth) acrylate and the liquid organic polymer is preferably 10 parts by mass or more from the viewpoint of suitably maintaining the hardness of the cured product and exerting sufficient adhesive force, and the compounding ratio of the monofunctional (meth) acrylate and the liquid organic polymer is preferably 80 parts by mass or less from the viewpoint of exerting the effect of suppressing oxygen inhibition by the component a and exerting sufficient adhesive force.

(component C: photoinitiator)

As the photoinitiator, a photoradical generator, a photobase generator, and the like can be used. The photo radical generator is a compound that generates radicals by irradiation with active energy rays such as ultraviolet rays or electron beams. Examples of the photo radical generator include benzoin ether derivatives, benzophenone derivatives, acetophenone derivatives, oxime ketone (oxime ketone) derivatives, acylphosphine oxide derivatives, titanocene (titanocene) derivatives, thioxanthone derivatives, quinone derivatives, and the like, and derivatives obtained by increasing the molecular weight thereof.

The photobase generator functions as a curing catalyst for the liquid organic polymer (B2) when irradiated with light. In particular, when the organic polymer contains a crosslinkable silicon group, a high effect is obtained. The photobase generator generates a base and a radical by the action of an active energy ray such as ultraviolet ray, electron beam, X-ray, infrared ray, and visible ray. It is possible to use: (1) a salt of an organic acid and a base which are decomposed by decarboxylation (decarboxylation) by irradiation with active energy rays such as ultraviolet rays, visible light, and infrared rays, (2) a compound which is decomposed by an intramolecular nucleophilic substitution reaction, a rearrangement reaction, or the like to release an amine, or (3) a compound which releases a base by a predetermined chemical reaction caused by irradiation with energy rays such as ultraviolet rays, visible light, and infrared rays. The radical generated by the photobase generator has a function of curing the component a, and the base generated by the photobase generator has a function of curing the liquid organic polymer containing a crosslinkable silyl group.

The base generated by the photobase generator is preferably an organic base such as an amine compound, and examples thereof include primary alkyl amines, primary aromatic amines, secondary alkyl amines, amines having a secondary amino group and a tertiary amino group, tertiary alkyl amines, tertiary heterocyclic amines, tertiary aromatic amines, amidines, and phosphazene (phosphazene) derivatives described in WO2015-088021 (hereinafter, also referred to as "document 1"). Among these, amine compounds having a tertiary amino group are preferable, and amidines and phosphazene (phosphazene) derivatives, which are strong bases, are more preferable. The amidine may be any of acyclic amidines and cyclic amidines, and more preferably a cyclic amidine. These bases may be used alone or in combination of 2 or more.

Examples of the acyclic amidines include guanidine compounds and biguanide (biguanide) compounds described in document 1. Among the acyclic amidine compounds, for example, the aryl-substituted guanidine compounds described in document 1 or the photobase generators that generate aryl-substituted biguanide compounds are preferable because when a catalyst that is a liquid organic polymer (B2) is used, the curability of the surface tends to be good, and the adhesiveness of the obtained cured product tends to be good.

Examples of the cyclic amidines include cyclic guanidine compounds, imidazoline compounds, imidazole compounds, tetrahydropyrimidine compounds, triazabicylene compounds, and diazabicycloalkene compounds described in document 1.

Among cyclic amidines, 1, 8-diazabicyclo [5.4.0] undec-7-ene (DBU) and 1, 5-diazabicyclo [4.3.0] non-5-ene (DBN) are particularly preferable from the viewpoint of easy industrial availability and the pKa value of the conjugate acid is 12 or more and high catalytic activity is exhibited.

As the photobase generator, various photobase generators can be used. The photolatent amine compound is preferably a photolatent amine compound which generates an amine compound under the action of an active energy ray. As the photolatent amine compound, there can be used: the photosensitive composition is characterized by comprising any one of a photolatent primary amine which generates an amine compound having a primary amino group by the action of an active energy ray, a photolatent secondary amine which generates an amine compound having a secondary amino group by the action of an active energy ray, and a photolatent tertiary amine which generates an amine compound having a tertiary amino group by the action of an active energy ray. From the viewpoint of generating a base exhibiting high catalytic activity, a photolatent tertiary amine is more preferable.

Examples of the photolatent primary amine and the photolatent secondary amine include: an o-nitrobenzyl carbamate compound described in document 1; dimethoxybenzyl carbamate compounds; benzoins of carbamic acid; o-acyloximes; o-carbamoyl oximes; n-hydroxyimidocarbamates; formanilide (formanilide) derivatives; aromatic sulfonamides; cobalt amine complexes, and the like.

As the photolatent tertiary amine, for example, there are listed: α -aminoketone derivatives, α -ammonium ketone (α -ammonium ketone) derivatives, benzylamine derivatives, benzylammonium salt derivatives, α -aminoolefin derivatives, α -ammonium olefin (α -ammonium alkone) derivatives, aminimides, benzyloxycarbonylamine derivatives that generate amidines by light, salts of carboxylic acids and tertiary amines, and the like described in document 1.

As the α -aminoketone compound, for example, there are listed: 5-naphthoylmethyl-1, 5-diazabicyclo [4.3.0] nonane, 5- (4' -nitro) phenacyl (phenacyl) -1, 5-diazabicyclo [4.3.0] nonane and the like give an alpha-aminoketone compound of amidine type, 4- (methylthiobenzoyl) -1-methyl-1-morpholinyl (morpholino) ethane (Irgacure 907), 2-benzyl-2-dimethylamino-1- (4-morpholinylphenyl) -butanone (Irgacure 369), 2- (4-methylbenzyl) -2-dimethylamino-1- (4-morpholinylphenyl) -butanone (Irgacure379), and the like give α -aminoketone compounds of tertiary amines having a tertiary amine group consisting of one nitrogen atom.

Examples of the α -ammonium ketone derivative include 1-naphthoylmethyl- (1-azonia) -4-azabicyclo [2,2,2] -octane) tetraphenylborate, and 5- (4' -nitro) phenacyl- (5-azonia-1-azabicyclo [4.3.0] -5-nonylidene) tetraphenylborate.

As the benzylamine derivative, for example, benzylamine derivatives such as 5-benzyl-1, 5-diazabicyclo [4.3.0] nonane, 5- (anthracen-9-yl-methyl) -1, 5-diazabicyclo [4.3.0] nonane, and 5- (naphthoyl-2-yl-methyl) -1, 5-diazabicyclo [4.3.0] nonane are exemplified.

Examples of the benzylammonium salt derivative include (9-anthryl) methyl-1-azabicyclo [2.2.2] octanium (octanium) tetraphenylborate, and 5- (9-anthrylmethyl) -1, 5-diazabicyclo [4.3.0] -5-nonenylium (nonenium) tetraphenylborate.

Examples of the α -aminoolefin derivative include 5- (2' - (2 "-naphthyl) allyl) -1, 5-diazabicyclo [4.3.0] nonane.

Examples of the α -ammonium olefin derivative include 1- (2' -phenylallyl) - (1-azonial-4-azabicyclo [2,2,2] -octane) tetraphenylboronate and the like.

Examples of the benzyloxycarbonylamine derivative which generates an amidine by utilizing light include benzyloxycarbonylimidazoles, benzyloxycarbonylguanidines, and diamine derivatives described in document 1.

As the salt of the carboxylic acid and the tertiary amine, an ammonium salt of α -ketocarboxylic acid and an ammonium salt of carboxylic acid described in document 1 are listed.

Among the photobase generators, a photolatent tertiary amine is preferable from the viewpoint of exhibiting high catalytic activity for generating a base, and a benzylammonium salt derivative, a benzyl-substituted amine derivative, an α -aminoketone derivative, and an α -aminoketone derivative are preferable from the viewpoint of high generation efficiency of a base, good storage stability as a photocurable adhesive, and the like. In particular, the α -aminoketone derivative and the α -aminoketone derivative are more preferable because the alkali generation efficiency is better, and the α -aminoketone derivative is more preferable in view of solubility in the compound. Among the α -aminoketone derivatives, α -aminoketone compounds in which the generated base is an amidine are preferable in view of the strength of the basicity to generate the base, and α -aminoketone compounds in which a tertiary amine having a tertiary amino group composed of one nitrogen atom is generated are exemplified from the viewpoint of the easiness of acquisition.

These photoinitiators may be used alone, or in combination of 2 or more. The mixing ratio of the photoinitiator is not particularly limited, but is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 40 parts by mass, and still more preferably 0.5 to 30 parts by mass with respect to 100 parts by mass of the liquid AB component.

The photocurable adhesive may contain a catalytic action accelerator that accelerates the catalytic action by being used together with a photoinitiator (in particular, a base generated from a photobase generator) within a range that does not inhibit the function and curing of the photocurable adhesive, thereby increasing the curing speed of the photocurable adhesive. Examples of the catalyst promoter include silicon compounds having an Si — F bond, fluorine compounds, and the like.

(silicon Compound having Si-F bond)

As the silicon compound having an Si — F bond, various compounds containing a silicon group having an Si — F bond (hereinafter, may be referred to as a "fluorosilyl group") can be used. As the silicon compound having an Si — F bond, any of an inorganic compound and an organic compound can be used, and any of a low molecular compound and a high molecular compound can be used without particular limitation. As the silicon compound having an Si — F bond, in the present invention, an organic compound having a fluorosilyl group is preferable, and an organic polymer having a fluorosilyl group is highly safe and more preferable. In addition, from the viewpoint of low viscosity of the photocurable adhesive, a low molecular weight organosilicon compound having a fluorosilyl group is preferable.

As the silicon compound having an Si — F bond, specifically, preferred examples include: examples of the fluorinated silane compound include fluorosilanes represented by the formula (7) described in document 1, compounds having a fluorosilyl group represented by the formula (8) described in document 1 (hereinafter, also referred to as fluorinated compounds), and organic polymers having a fluorosilyl group described in document 1 (hereinafter, also referred to as fluorinated polymers).

R¹¹ _4-dSiF_d···(7)

(in the formula (7), R¹¹Each independently represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or R¹²SiO-(R¹²Each independently a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or a fluorine atom). d is any one of 1 to 3, and d is preferably 3. R¹¹And R¹²When a plurality of the compounds exist, they may be the same or different. )

-SiF_dR¹¹ _eZ_f···(8)

(in the formula (8), R¹¹And d is the same as formula (7), each Z is independently hydroxyl or other hydrolytic groups except fluorine, e is any one of 0-2, f is any one of 0-2, d + e + f is 3. R¹¹、R¹²And when there are a plurality of Z, they may be the same or different. )

Examples of the fluorosilanes represented by formula (7) include fluorosilanes represented by formula (7). Examples thereof include fluorodimethylphenylsilane, vinyltrifluorosilane, γ -methacryloxypropyltrifluorosilane, and octadecyltrifluorosilane.

In the compound having a fluorosilyl group represented by the formula (8), the hydrolyzable group represented by Z is preferably an alkoxy group, and R is preferably R, from the viewpoint of mild hydrolyzability and easy handling¹¹Preferably methyl. The hydrolyzable group is preferably an alkenyloxy group, and particularly preferably an alkoxy group from the viewpoint of mild hydrolyzability and easy handling.

When the fluorosilyl group represented by the formula (8) is exemplified, a silicon group or R having no hydrolyzable group other than fluorine is preferred¹¹The fluorosilyl group which is a methyl group, more preferably a trifluorosilyl group.

The compound having a fluorosilyl group represented by the formula (8) is not particularly limited, and either a low-molecular compound or a high-molecular compound can be used. For example, mention may be made of: inorganic silicon compounds, low molecular weight organosilicon compounds such as vinyldifluoromethoxysilane, vinyltrifluorosilane, phenyldifluoromethoxysilane, phenyltrifluorosilane, and the like, and high molecular weight compounds such as fluorinated polysiloxane having a fluorosilyl group represented by formula (8) at the terminal; preferred are fluorosilanes represented by the formula (7) and polymers having a fluorosilyl group represented by the formula (8) at the end of the main chain or side chain.

As the organic polymer having a fluorosilyl group (hereinafter, also referred to as a fluorinated polymer), various organic polymers having an Si — F bond can be used.

As regards the fluorinated polymer, it may be: a single polymer in which the fluorosilyl groups and the main chain skeleton are the same, that is, a single polymer in which the number of fluorosilyl groups per 1 molecule, the bonding positions thereof, the number of F groups contained in the fluorosilyl groups, and the main chain skeleton are the same; it can also be: any one of them, or all of them, is a mixture of different polymers. Any of these fluorinated polymers can be preferably used as a resin component of a photocurable adhesive exhibiting rapid curability.

As the main chain skeleton of the fluorinated polymer, specifically, a main chain skeleton of a crosslinkable silicon group-containing organic polymer can be used, and since the ease of handling and the physical properties are good, a polyoxyalkylene polymer such as polyoxypropylene, polyoxytetramethylene, and a polyoxyethylene-polyoxypropylene copolymer, a (meth) acrylate copolymer, and the like are preferable, a polyoxyalkylene polymer is more preferable, and polyoxypropylene is most preferable.

The fluorinated polymer may be linear or may have a branch. The number average molecular weight of the fluorinated polymer is preferably 3,000 to 100,000, more preferably 3,000 to 50,000, and particularly preferably 3,000 to 30,000 in terms of polystyrene in GPC. When the number average molecular weight is less than 3,000, it is inconvenient in view of the elongation properties of the cured product, and when it exceeds 100,000, it becomes high viscosity, so that it is inconvenient in view of workability.

The compounding ratio of the silicon compound having an Si — F bond is not particularly limited, but is preferably 0.01 to 30 parts by mass, and more preferably 0.05 to 20 parts by mass, based on 100 parts by mass of the total of the components a and B. When a high molecular compound having a number average molecular weight of 3,000 or more such as a fluorinated polymer is used as the silicon compound having an Si — F bond, the amount is preferably 0.01 to 80 parts by mass, more preferably 0.01 to 30 parts by mass, and still more preferably 0.05 to 20 parts by mass, based on 100 parts by mass of the liquid AB component. When a low-molecular-weight compound having a fluorosilyl group with a number average molecular weight of less than 3,000 (for example, a low-molecular-weight organosilicon compound having a fluorosilane group represented by formula (7) and/or a fluorosilyl group represented by formula (8), an inorganic silicon compound having a fluorosilyl group, or the like) is used as the silicon compound having an Si — F bond, the amount is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, based on 100 parts by mass of the liquid AB component.

(fluorine-containing Compound)

The fluorine-based compound includes 1 or more fluorine-based compounds selected from the group consisting of boron trifluoride, a complex of boron trifluoride, a fluorinating agent, and an alkali metal salt of a multi-fluorine compound. The fluorine-based compound functions as a compound that promotes a hydrolytic condensation reaction of the crosslinkable silicon group.

Examples of the complex of boron trifluoride include an amine complex, an alcohol complex, and an ether complex of boron trifluoride. Among the complexes of boron trifluoride, particularly preferred are amine complexes having both stability and catalytic activity.

Examples of the amine compound used in the amine complex of boron trifluoride include monoethylamine and piperidine.

The mixing ratio of the fluorine-based compound is not particularly limited, but is preferably 0.001 to 10 parts by mass, more preferably 0.001 to 5 parts by mass, and still more preferably 0.001 to 2 parts by mass, relative to 100 parts by mass of the liquid AB component. These fluorine-containing compounds may be used alone, or 2 or more kinds may be used in combination.

The photocurable adhesive may contain 1 or more selected from the group consisting of silicon compounds having Si — F bonds and fluorine compounds. In particular, in the case where the photocurable adhesive functions as an adhesive for post-curing (i.e., an adhesive), it is preferable that the liquid organic polymer (B2) contains an organic polymer containing a crosslinkable silicon group, and the photocurable adhesive contains a silicon compound having an Si — F bond.

(component D: tackifying resin)

The tackifier resin as the component D is not particularly limited, and examples thereof include resins having a polar group such as rosin ester resin, phenol resin (phenol resin), xylene resin, xylene phenol resin, terpene phenol resin (terpene phenol resin), various petroleum resins such as aromatic series, aliphatic-aromatic copolymer series, and alicyclic series having relatively small polarity, and general tackifier resins such as benzofuran resin, low-molecular weight polyethylene resin, terpene resin (terpene resin), and hydrogenated resins thereof. These may be used alone, or 2 or more of them may be used in combination.

Specific examples of the resins include aromatic styrene resins such as an α -methylstyrene single polymer resin [ FTR Zero series, manufactured by Mitsui chemical Co., Ltd ], a styrene monomer single polymer resin [ FTR 8000 series, manufactured by Mitsui chemical Co., Ltd ], a styrene monomer/aromatic monomer copolymer resin [ FMR series, manufactured by Mitsui chemical Co., Ltd ], and an α -methylstyrene/styrene copolymer resin [ FTR2000 series, manufactured by Mitsui chemical Co., Ltd ]. Examples of the aliphatic-aromatic copolymer-based petroleum resin include aliphatic-aromatic copolymer-based styrene resins such as styrene-based monomer/aliphatic monomer copolymer-based resin [ FTR 6000 series, manufactured by mitsui chemical co., ltd ], styrene-based monomer/α -methylstyrene/aliphatic monomer copolymer-based resin [ FTR 7000 series, manufactured by mitsui chemical co., ltd ].

From the viewpoint of compatibility with the component B, the solubility parameter (hereinafter, abbreviated as "SP value" in principle) calculated by the Small method using the Hoy constant is preferably 7.9 to 11.0, more preferably 8.2 to 9.8, and most preferably 8.5 to 9.5. From the viewpoint of the adhesive strength of the pressure-sensitive adhesive, it is preferable to select a resin having a polarity comparable to that of the adherend. When the tackifier resin is used for an adherend having a low polarity, it is preferable to use the tackifier resin having a low polarity, and when the tackifier resin is used for an adherend having a high polarity, it is preferable to use the tackifier resin having a high polarity. When the tackifier resin is used for a wide range of adherends from a highly polar adherend to a less polar adherend, it is preferable to use the tackifier resin having a low polarity and the tackifier resin having a high polarity in a mixed state. Regarding the polarity (SP value) of the terpene phenol resin, the SP value of the U series of YS Polystar (manufactured by Yasuhara Chemical co., ltd.) was 8.69, the SP value of the T series was 8.81, the SP value of the S series was 8.98, the SP value of the G series was 9.07, and the SP value of the K series was 9.32. By selecting the polarity (SP value), it is possible to adapt to various kinds of polar adherends ranging from an adherend having low polarity to an adherend having high polarity.

The tackifier resin is preferably a terpene phenol resin or an aromatic petroleum resin from the viewpoint of good compatibility with the component B. The aromatic petroleum resin is preferably an aromatic styrene resin or an aliphatic-aromatic copolymer styrene resin, and more preferably a terpene phenol resin or an aliphatic-aromatic copolymer styrene resin. From the viewpoint of excellent adhesion, a terpene phenol resin is most preferable. In addition, from the viewpoint of VOC, an aliphatic-aromatic copolymer-based styrene resin is preferably used.

The blending ratio of the tackifier resin is preferably 5 to 200 parts by mass, more preferably 10 to 150 parts by mass, per 100 parts by mass of the components a and B1 and/or B2 (when both the components B1 and B2 are used, 100 parts by mass of the total of the components a, B1 and B2). From the viewpoint of developing the adhesive force, it is preferably 5 parts by mass or more; from the viewpoint of maintaining the hardness of the cured product appropriately, exerting sufficient adhesive force, and ensuring good workability, 200 parts by mass or less is preferable.

(component E: a polyfunctional monomer having a photoradically polymerizable vinyl group, a polyfunctional polymer having a photoradically polymerizable vinyl group)

The photocurable adhesive of the present invention may contain a polyfunctional monomer from the viewpoint of ensuring adhesiveness at high temperature. The higher the functional group of the polyfunctional monomer is, the higher the adhesive force of the photocurable adhesive at high temperature becomes. In addition, the number of functional groups of the polyfunctional monomer is preferably 2 or more, since the hardness of the photocurable adhesive after curing becomes a predetermined hardness or more when the number of functional groups is a predetermined number or more. Further, when the molecular weight of the polyfunctional monomer is equal to or more than a predetermined molecular weight, it contributes to maintaining flexibility of the photocurable adhesive.

As the polyfunctional monomer, for example, a compound (E) having a photo radical polymerizable vinyl group is used. In addition, as the (E) compound having a photo radical polymerizable vinyl group, various polyfunctional monomers having a photo radical polymerizable vinyl group can be used. For example, a compound having a (meth) acryloyl group, an N-vinyl compound in which a vinyl group is directly bonded to a nitrogen atom, or the like can be used.

In addition, it is preferable that the photocurable adhesive contains a polyfunctional (meth) acrylate as a crosslinking agent for the purpose of imparting heat resistance, high-temperature cohesive strength, or the like. As the polyfunctional (meth) acrylate, a polyfunctional (meth) acrylate monomer, an oligomer/polymer of a polyfunctional (meth) acrylate (also, an oligomer and a polymer may be combined to be referred to as a polymer) are listed. For the purpose of maintaining flexibility of the photocurable adhesive, it more preferably contains: a polyfunctional polymer having a photoradically polymerizable vinyl group is used as a polyfunctional (meth) acrylate polymer in which the crosslinking distance can be made longer.

Examples of the polyfunctional (meth) acrylate monomer having 2 or more (meth) acryloyl groups include 2-functional (meth) acrylate monomers such as 1, 6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, polypropylene glycol di (meth) acrylate, 2-bis (4- (meth) acryloyloxydiethoxyphenyl) propane, 2-bis (4- (meth) acryloyloxytetraethoxyphenyl) propane and the like, trimethylolpropane tri (meth) acrylate, tris [ (meth) acryloylethyl ] isocyanurate and the like, and (meth) acrylate monomers having 4 or more functional groups such as dimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, and pentaerythritol ethoxytetra (meth) acrylate. From the viewpoint of maintaining flexibility of the photocurable adhesive, a 2-functional (meth) acrylate monomer is preferable, and from the viewpoint of good reactivity, a 3-functional (meth) acrylate monomer and a 4-or more-functional (meth) acrylate monomer are preferable.

The amount of the polyfunctional (meth) acrylate monomer is preferably 0.01 to 5 parts by weight based on 100 parts by weight of the component A, the component B1, and/or the other monofunctional (meth) acrylate monomer. The amount of the polyfunctional (meth) acrylate monomer blended is preferably 0.01 parts by weight or more from the viewpoint of ensuring sufficient cohesive force under high-temperature conditions, and preferably 5 parts by weight or less from the viewpoint of ensuring good adhesive properties.

As the polyfunctional (meth) acrylate polymer, there are enumerated: polyether urethane (meth) acrylates (e.g., "UV-3700B", "UV-6100B" manufactured by Nippon Synthesis Co., Ltd.), polyester urethane (meth) acrylates (e.g., "UV-2000B", "UV-3000B", "UV-7000B" manufactured by Nippon Synthesis Co., Ltd., "KHP-11", "KHP-17", non-aromatic polycarbonate urethane (meth) acrylates (e.g., "Art Resin UN-9200A" manufactured by Nippon Synthesis Co., Ltd.), acrylic (meth) acrylates (e.g., "RC-300", "RC-100", "RC-200", 1, 2-polybutadiene terminal urethane (meth) acrylates (e.g., "TE-2000" manufactured by Nippon soda Co., Ltd., "TE-2000"), "TEA-1000"), a hydrogenated product of 1, 2-polybutadiene terminal urethane (meth) acrylate (e.g., "TEAI-1000" manufactured by japan caoda), 1, 4-polybutadiene terminal urethane (meth) acrylate (e.g., "BAC-45" manufactured by osaka organic chemical company), polyisoprene terminal (meth) acrylate, bisphenol a type epoxy (meth) acrylate, and the like.

From the viewpoint of compatibility with the components a and B, polyether urethane (meth) acrylate, acrylic (meth) acrylate, polyester urethane (meth) acrylate, and non-aromatic polycarbonate urethane (meth) acrylate are preferable, and from the viewpoint of good compatibility with the components a and B and ensuring flexibility of the cured product, polyether urethane (meth) acrylate and acrylic (meth) acrylate are more preferable, and polyether urethane (meth) acrylate is even more preferable.

The molecular weight of the polyfunctional (meth) acrylate polymer is 500 to 50,000, and from the viewpoint of flexibility of the cured photocurable adhesive, the molecular weight is preferably 3,000 to 45,000, and more preferably 5,000 to 20,000. The glass transition temperature (Tg) is preferably 0 ℃ or lower from the viewpoint of maintaining or improving the adhesive performance of the photocurable adhesive.

The amount of the polyfunctional (meth) acrylate polymer is preferably 3 to 30 parts by weight, more preferably 5 to 25 parts by weight, based on 100 parts by weight of the component A, the component B1, and/or the other monofunctional (meth) acrylate. The amount of the crosslinking agent is preferably 3 parts by weight or more from the viewpoint of exhibiting sufficient cohesive force under high-temperature conditions, and preferably 30 parts by weight or less from the viewpoint of ensuring good adhesive properties.

(other additives)

The photocurable adhesive of the present invention may also contain, as required, various additives such as a conductive filler, an N-vinyl compound, a compound having a (meth) acrylamide group, a silane coupling agent, a photosensitizer, an extender, a plasticizer, a moisture absorber, a curing catalyst, a physical property modifier for improving tensile properties, a reinforcing agent, a coloring agent, a flame retardant, a sagging inhibitor, an antioxidant, an antiaging agent, an ultraviolet absorber, a solvent, a perfume, a pigment, a dye, a filler, and a diluent.

(conductive Filler)

As for the conductive filler, there can be used: carbon particles, metal particles such as silver, copper, nickel, gold, tin, zinc, platinum, palladium, iron, tungsten, molybdenum, and solder, or alloy particles, or conductive particles such as particles prepared by coating the surfaces of these particles with a conductive coating layer such as a metal. For example, conductive particles obtained by applying conductive coating of a metal or the like to the surface of polymer particles, which are nonconductive particles made of polyethylene, polystyrene, a phenol resin, an epoxy resin, an acrylic resin, or a benzoguanamine resin, or to the surface of inorganic particles made of glass beads, silica (silica), graphite, or ceramics may be used.

As the shape of the conductive filler, various shapes (for example, spherical shape, elliptical shape, cylindrical shape, sheet, needle shape, resin shape, whisker (whisker), plate, pellet, crystal, needle shape (acicular), or the like) can be employed. The conductive filler may be slightly roughened or may have a jagged surface. The shape of the conductive filler is not particularly limited. The conductive filler can be used in the photocurable adhesive by combining the particle shape, size, and/or hardness of the conductive filler. In order to further improve the conductivity of the photocurable adhesive, it is preferable to combine a plurality of conductive fillers having different particle shapes, sizes, and/or hardnesses from each other. As an example, it is preferable to use a mixture of a granular conductive filler and a flake conductive filler. The number of the conductive fillers to be combined is not limited to 2, and may be 3 or more.

(N-vinyl Compound having vinyl group)

Examples of the N-vinyl compound having a vinyl group include N-vinylpyrrolidone and N-vinylcaprolactam. In the present invention, an N-vinyl compound is preferable from the viewpoint of reactivity and difficulty in causing oxygen inhibition.

(Compound having N-methyl (meth) acrylamide group)

Examples of the compound having an N-meth (meth) acrylamide group include N-meth (meth) acrylamide, N- (meth) acryloylmorpholine, and acryloylmorpholine is preferable because the balance among curability, physical properties, and safety is good.

(silane coupling agent)

The silane coupling agent functions as an adhesion imparting agent. Examples of the silane coupling agent include epoxy group-containing silanes such as γ -glycidoxypropyltrimethoxysilane and β - (3, 4-epoxycyclohexyl) ethyltrimethoxysilane; amino group-containing silanes such as γ -aminopropyltrimethoxysilane and N- (β -aminoethyl) - γ -aminopropyltrimethoxysilane; ketimine (ketimine) type silanes such as N- (1, 3-dimethyl (meta) butylene) -3- (triethoxysilyl) -1-propanamine; mercapto group-containing silanes such as gamma-mercaptopropyltrimethoxysilane; silanes containing a vinyl-type unsaturated group such as vinyltrimethoxysilane and gamma-methacryloxypropyltrimethoxysilane; silanes containing chlorine atoms such as gamma-chloropropyltrimethoxysilane; silanes containing an isocyanate group such as γ -isocyanatopropyltriethoxysilane; alkylsilanes such as decyltrimethoxysilane; and phenyl group-containing silanes such as phenyltrimethoxysilane, but not limited thereto. Further, there may be used a modified amino group-containing silane obtained by reacting an amino group-containing silane with an epoxy group-containing compound, an isocyanate group-containing compound, and a (meth) acryloyl group-containing compound, including the above-mentioned silanes, to modify the amino group.

(silanes containing amino group)

The amino group-containing silanes function as silanol condensation catalysts, and the ketimine-type silanes generate amino group-containing silanes in the presence of moisture, which function as silanol condensation catalysts. Therefore, silane coupling agents other than amino group-containing silanes or ketimine type silanes are preferably used. When amino group-containing silanes or ketimine-type silanes are used, they should be used in amounts and with attention to the type of silanes or the amount of silanes used, within the range of achieving the objects and effects of the present invention.

(Photoaminosilane-generating Compound)

As described above, there are cases where the use of the amino group-containing silanes or ketimine-type silanes in the present invention is limited. However, in the case where amino group-containing silanes or ketimine type silanes are preferably used as the adhesiveness imparting agent, it is possible to use: a compound which does not generate a compound having an amino group before light irradiation and generates a silane compound containing an amino group by light irradiation (hereinafter, also referred to as a photo-aminosilane generating compound). As the photo-aminosilane generating compound, there are listed: the photofunctional group described in document 1 is a compound such as o-nitrobenzyl, p-nitrobenzyl, oxime residue (oxime), benzyl, benzoyl, or substituted of these groups. Examples of the photo-aminosilane-generating compound having a photo-functional group of o-nitrobenzyl group include 2-nitrobenzyl-N- [3- (trimethoxysilyl) propyl ] carbamate, 2-nitrobenzyl-N- [3- (triethoxysilyl) propyl ] carbamate, and 3, 4-dimethoxy-2-nitrobenzyl-N- [3- (trimethoxysilyl) propyl ] carbamate. Examples of the photo-aminosilane-generating compound having a p-nitrobenzyl group as a photo-functional group include 4-nitrobenzyl-N- [3- (trimethoxysilyl) propyl ] carbamate. Examples of the photo-aminosilane-generating compound having a photo-functional group of benzyl group include 1- (3, 5-dimethoxyphenyl) -1-methylethyl-N- [3- (trimethoxysilyl) propyl ] carbamate and the like. As the photo-aminosilane generating compound whose photo-functional group is an oxime residue, benzophenone O- { [3- (trimethoxysilyl) propyl ] } oxime and the like are exemplified.

The compounding ratio of the silane coupling agent is not particularly limited, but is preferably 0.01 to 20% by mass, more preferably 0.025 to 10% by mass in the photocurable adhesive. These silane coupling agents may be used alone, or 2 or more of them may be used in combination.

(moisture absorbent)

As the moisture absorbent, the aforementioned silane coupling agent or silicate (silicate) is preferable. The silicate is not particularly limited, and examples thereof include tetramethoxysilane, tetraalkoxysilane, and the like, and a partial hydrolysis condensate thereof.

(other condensation reaction promoting catalysts)

As the other condensation reaction promoting catalyst other than the component (C) or the compound having an Si-F bond, a known curing catalyst can be widely used, and there are no particular limitations on the catalyst, and examples thereof include organic metal compounds, amines, fatty acids, organic acid phosphate ester compounds, and the like, and particularly, a silanol condensation catalyst is preferably used. As the silanol condensing catalyst, for example, organotin compounds are cited; a dialkyltin oxide; a reactant of dibutyltin oxide and phthalic acid ester, etc.; titanates; organoaluminum compounds; chelate compounds such as titanium tetraacetylacetonate; organic acid bismuth, and the like. However, the organotin compound may increase the toxicity of the obtained photocurable adhesive depending on the amount of the compound added. Since the component (C) or the compound having an Si — F bond of the present invention functions as a condensation reaction promoting catalyst, when a curing catalyst other than these is used, it is preferably used in a range that can achieve the object or effect of the present invention.

(Filler)

As for the filler other than the conductive filler, a resin filler (resin fine powder) or an inorganic filler can be used. As the resin filler, a particulate filler containing an organic resin or the like can be used. For example, organic fine particles such as a polyethylacrylate resin, a polyurethane resin, a polyethylene resin, a polypropylene resin, a urea resin, a melamine resin, a benzoguanamine resin, a phenol resin, an acrylic resin, and a styrene resin can be used as the resin filler.

As the resin filler (resin fine powder), a filler in a regular spherical shape which is easily obtained by suspension polymerization or the like of a monomer (for example, methyl methacrylate) is preferable. The resin filler is preferably contained in the photocurable adhesive as a filler, and is preferably a spherical crosslinked resin filler. When the photocurable adhesive for manufacturing a peripheral portion of a liquid crystal display device or the like is used in an application requiring light-shielding properties, the resin filler preferably contains a black resin filler. By using a black resin filler having an average particle diameter of 1 to 150 μm, good deep-part curability can be obtained even when a single-wavelength LED lamp or the like is used, and excellent light-shielding properties and deep-part curability can be achieved.

Examples of the inorganic filler extender include talc, clay, calcium carbonate, magnesium carbonate, anhydrous silicon, hydrous silicon, calcium silicate, titanium dioxide, carbon black and the like. These may be used alone, or 2 or more of them may be used in combination.

(Diluent)

The photocurable adhesive of the present invention may further contain a diluent. The physical properties such as viscosity of the photocurable adhesive can be adjusted by adding a diluent. The diluent is not particularly limited, and examples thereof include various solvents such as saturated hydrocarbon solvents such as normal paraffin and isoparaffin, α -olefin derivatives such as HS dimer (trade name, manufactured by yokoku corporation), alcohol solvents such as aromatic hydrocarbon solvents and diacetone alcohol, ester solvents, citrate solvents such as triethyl acetylcitrate, and ketone solvents.

The flash point (flash point) of the diluent is not particularly limited, but when the safety of the photocurable adhesive is taken into consideration, the flash point of the photocurable adhesive is preferably high, and the volatile matter derived from the photocurable adhesive is preferably low. Therefore, the flash point of the diluent is preferably 60 ℃ or higher, more preferably 70 ℃ or higher. When 2 or more diluents are mixed, the flash point of the diluent obtained by mixing is preferably 70 ℃ or higher. In general, since a diluent having a high flash point tends to have a low dilution effect with respect to a photocurable adhesive, the flash point is preferably 250 ℃ or lower.

In consideration of both safety and dilution effect of the photocurable adhesive, the diluent is preferably a saturated hydrocarbon solvent, and more preferably n-alkane or isoparaffin. The number of carbon atoms of the normal paraffin and the isoparaffin is preferably 10 to 16.

The blending ratio of the diluent is not particularly limited, but from the viewpoint of improving the coating workability by blending and reducing the balance of physical properties, the blending ratio is preferably 0 to 25%, more preferably 0.1 to 15%, and still more preferably 1 to 7% in the photocurable adhesive. These diluents may be used alone or in combination of 2 or more.

(method for producing photocurable adhesive)

The method for producing the photocurable adhesive is not particularly limited, and for example, it can be produced by blending predetermined amounts of the components a, B1 and/or B2, and C, and further blending other blending substances as necessary, and degassing and stirring them. The order of compounding the respective ingredients and other compounding substances is not particularly limited and can be determined as appropriate.

The photocurable adhesive of the present invention may be in a single form or in a double form as required, but it is particularly preferable to use it in a single form. The photocurable adhesive of the present invention is a photocurable adhesive which exhibits adhesiveness by irradiation with light and is cured, can be cured at room temperature (for example, 23 ℃), and is suitable as a room-temperature photocurable adhesive, but if necessary, can be cured by heating as appropriate.

The photocurable adhesive of the present invention exhibits adhesiveness when irradiated with light and cures. This curing can be used to obtain a cured product of the photocurable adhesive. The photocurable adhesive of the present invention can be used to produce various adhesive-containing products such as electronic circuits, electronic components, building materials, and automobiles.

The photocurable adhesive of the present invention is not particularly limited as the conditions for irradiation with light, but when active energy rays are irradiated at the time of curing, in addition to light rays such as ultraviolet rays, visible rays, and infrared rays, electromagnetic waves such as X-rays and γ -rays, electron beams, proton beams, and neutral beams can be used as the active energy rays. From the viewpoints of curing speed, ease and price of acquisition of an irradiation device, ease of handling under sunlight and/or general illumination, and the like, curing by ultraviolet ray or electron beam irradiation is preferable, and curing by ultraviolet ray irradiation is more preferable. In addition, the ultraviolet ray also includes g-line (wavelength: 436nm), h-line (wavelength: 405nm), i-line (wavelength: 365nm), and the like. The active energy source is not particularly limited, but depending on the nature of the photobase generator used, examples thereof include a high-pressure mercury lamp, a low-pressure mercury lamp, an electron beam irradiation device, a halogen lamp, a light-emitting diode, a semiconductor laser, and a metal halide, and a light-emitting diode is preferable.

The irradiation energy is preferably 10 to 20,000mJ/cm in the case of ultraviolet rays, for example²More preferably 20 to 10,000mJ/cm²More preferably 50 to 5,000mJ/cm². Less than 10mJ/cm²In the case where the curing property is insufficient, the curing property may be more than 20,000mJ/cm²In the case of this, even if light is irradiated in an amount more than necessary, time and cost may be wasted, and the substrate may be damaged.

The method of applying the photocurable adhesive of the present invention to an adherend is not particularly limited, but application methods such as screen printing, stencil printing, roll printing, dispenser (dispenser) application, and spin coating are preferably used.

The time of application and light irradiation of the photocurable adhesive to an adherend is not limited. For example, a product (i.e., an adhesive body) can be produced by irradiating a photocurable adhesive with light and then bonding the adhesive to an adherend. In addition, a product can be produced by applying a photocurable adhesive to an adherend and irradiating the adherend with light to cure the photocurable adhesive.

For example, when adherends are bonded to each other, the photocurable adhesive of the present invention is applied to at least one of the adherends (application step). In the coating step, a photocurable adhesive may be applied to one adherend, or a photocurable adhesive may be applied to each of both adherends. In addition, from the viewpoint of simplifying the coating process, the photocurable adhesive may be applied to only one adherend. Next, the photocurable adhesive is irradiated with light (light irradiation step). The photocurable adhesive exhibits adhesion upon irradiation with light. Next, after the light irradiation, the other adherend is brought into contact with the photocurable adhesive applied to the one adherend and irradiated with the light. That is, the other adherend is bonded to the one adherend by sandwiching the photocurable adhesive applied to the one adherend between the other adherend (bonding step). Then, the other adherend is bonded to the one adherend (bonding step). In this way, a product (i.e., an adherend) obtained by bonding adherends to each other is produced. However, a protective member such as a protective sheet on the pressure-sensitive adhesive surface is removed from the other adherend. This is because the photocurable adhesive used in the bonding method of the present invention is for on-site work, and one adherend is directly bonded to another adherend using the photocurable adhesive.

The photocurable adhesive of the present invention is a quick-curing type photocurable adhesive having excellent workability, and can be preferably used as an adhesive.

(effects of the embodiment)

The photocurable adhesive of the present invention is in a liquid state before light irradiation, and thus can be applied not only directly to an adherend but also to an adherend having a complicated shape. Further, the photocurable adhesive exhibits adhesion rapidly by light irradiation even without being blocked from the outside air. Therefore, according to the photocurable adhesive of the present invention, since the photocurable adhesive is applied to one adherend, irradiated with light, and then the other adherend is bonded to the photocurable adhesive exhibiting adhesiveness, even when the adherend does not transmit light such as ultraviolet light, a plurality of adherends can be easily bonded to each other.

That is, the photocurable adhesive of the present invention is a photocurable adhesive which is not cured when no active energy ray is irradiated and is cured by irradiation with an active energy ray even without being blocked from the outside air (i.e., even if not covered with a film or the like), and is a photocurable adhesive having quick curability and excellent initial adhesion after irradiation with an active energy ray. Therefore, a predetermined possible time for bonding can be secured after the light irradiation.

Examples

The following examples are given to illustrate the present invention more specifically. These examples are illustrative and should not be construed as being limitative.

Synthesis example 1 Synthesis of polyoxyalkylene Polymer A1 having trimethoxysilyl group at the end

Propylene oxide was reacted with ethylene glycol as an initiator in the presence of a zinc hexacyanocobaltate-glyme (glyme) complex catalyst to obtain a polyoxypropylene glycol. According to the method of synthetic example 2 of WO2015-088021, a polyoxyalkylene polymer having an allyl group at the end of polyoxypropylene diol was obtained. On the other hand, a polyoxyalkylene polymer having an allyl group at the terminal thereof was reacted by adding a platinum vinylsiloxane complex isopropanol solution of trimethoxysilane as a silicon hydride compound to obtain a polyoxyalkylene polymer A1 having a trimethoxysilyl group at the terminal thereof.

The molecular weight of the obtained polyoxyalkylene polymer A1 having trimethoxysilyl groups at the terminals was measured by GPC, and the peak top molecular weight was 25,000, and the molecular weight distribution was 1.3. According to¹The number of trimethoxysilyl groups at the end was 1.7 per 1 molecule as determined by H-NMR.

Synthesis example 2 Synthesis of polyoxyalkylene Polymer A2 having trimethoxysilyl group at the end

Propylene oxide was reacted with ethylene glycol as an initiator in the presence of a zinc hexacyanocobaltate-glyme complex catalyst to obtain a polyoxypropylene glycol. According to the method of synthetic example 2 of WO2015-088021, a polyoxyalkylene polymer having an allyl group at the end of polyoxypropylene diol was obtained. On the other hand, a polyoxyalkylene polymer having an allyl group at the terminal thereof was reacted by adding a platinum vinylsiloxane complex isopropanol solution of trimethoxysilane as a silicon hydride compound to obtain a polyoxyalkylene polymer A2 having a trimethoxysilyl group at the terminal thereof.

The molecular weight of the obtained polyoxyalkylene polymer A2 having trimethoxysilyl groups at the terminals was measured by GPC, and the peak top molecular weight was 12,000, and the molecular weight distribution was 1.3. According to¹The number of trimethoxysilyl groups at the end was 1.7 per 1 molecule as determined by H-NMR.

Synthesis example 3 Synthesis of (meth) acrylic Polymer A3 having trimethoxysilyl group

(meth) acrylic polymer A3 having a trimethoxysilyl group was obtained by the method of Synthesis example 4 of WO2015-088021 using 70.00g of methyl methacrylate, 30.00g of 2-ethylhexyl methacrylate, 12.00g of 3-methacryloxypropyltrimethoxysilane, 0.10g of titanocene dichloride (titanocene dichloride) as a metal catalyst, 8.60g of 3-mercaptopropyltrimethoxysilane, and 20.00g of a benzoquinone solution (95% THF solution) as a polymerization stopper. The (meth) acrylic polymer a3 had a peak top molecular weight of 4,000 and a molecular weight distribution of 2.4. According to¹The trimethoxysilyl group content was 2.00 per 1 molecule as determined by H-NMR.

Synthesis example 4 Synthesis of fluorinated Polymer

A polyoxypropylene diol having a molecular weight of about 2,000 was used as an initiator, and propylene oxide was reacted in the presence of a zinc hexacyanocobaltate-glyme complex catalyst to obtain a polyoxypropylene diol having a molecular weight distribution of 1.3 and a hydroxyl value equivalent to 14,500. According to the method of synthetic example 2 of WO2015-088021, a polyoxyalkylene polymer having an allyl group at the end of polyoxypropylene diol was obtained. Platinum vinyl siloxane complex obtained by adding methyldimethoxysilane as a hydrosilicon compound to polyoxyalkylene polymer having allyl group at the terminalThe reaction was carried out in an isopropanol solution to obtain a polyoxyalkylene polymer A4 having a methyldimethoxysilyl group at the terminal. The molecular weight of the obtained polyoxyalkylene polymer A4 having methyldimethoxysilyl groups at the terminal was measured by GPC, and the peak top molecular weight was 15,000 and the molecular weight distribution was 1.3. According to¹The number of terminal methyldimethoxysilyl groups was 1.7 per 1 molecule as determined by H-NMR.

Then, use BF₃2.4g of the ether complex, 1.6g of dehydrated methanol, 100g of the polymer A4, and 5g of toluene, a polyoxyalkylene polymer having a fluorosilyl group at the terminal (hereinafter referred to as "fluorinated polymer") was obtained in accordance with the method of synthetic example 4 of WO 2015-088021. Measuring the obtained fluorinated polymers¹H-NMR spectrum (NMR 400 manufactured by Shimazu corporation, in CDCl)₃Measured in a solvent), the result was silylmethylene (-CH) of the polymer A4 as a starting material₂-Si) disappears, and a broad peak appears on the low magnetic field side (0.7ppm to 0.63 ppm).

Synthesis example 5 Synthesis of crosslinkable silyl group-containing Compound F1 in which amino group was formed Using light

15.3 parts of 2-nitrobenzyl alcohol and 344 parts of toluene were added to the flask and refluxed at about 113 ℃ for 60 minutes. Then, 20.5 parts of 3-isocyanatopropyltrimethoxysilane was added dropwise thereto and the mixture was stirred for 5 hours to obtain a composition (a crosslinkable silyl group-containing compound represented by the following formula (9) in which an amino group is formed by utilizing light (hereinafter referred to as "photo-aminosilane-generating compound F1")). As a result of IR spectrum measurement of the aminosilane-producing compound F1, no — N ═ C ═ O bond was detected.

[ chemical formula 5]

(example 1)

The photocurable adhesive was prepared by adding each of the compounding materials to a flask equipped with a stirrer, a thermometer, a nitrogen inlet, a monomer-charging tube, and a water-cooled condenser at the compounding ratios shown in table 1, and mixing and stirring the materials.

TABLE 1

In table 1, the unit of the compounded amount of each compounded substance is "g". The details of the compounding agent are as follows. The component B includes a component B1 and a component B2.

[ component A: monoacrylate ]

(2HPPA-M600A) 2-hydroxy-3-phenoxypropyl acrylate (product name: M-600A, manufactured by Kyoeisha chemical Co., Ltd.)

[ B1 ingredient: monofunctional (meth) acrylates ]

(LA) lauryl Acrylate (product name: Light Acrylate L-A, manufactured by Kyoeisha chemical Co., Ltd.)

(2HEA) hydroxyethyl acrylate (product name: HEA, manufactured by Osaka organic chemical Co., Ltd.)

(2HBA) 2-hydroxybutyl acrylate (product name: HOB-A, of Kyoeisha chemical Co., Ltd.)

(ACMO) 4-acryloylmorpholine (product name: ACMO, manufactured by KJ Chemicals Corporation)

[ B2 ingredient: liquid organic Polymer ]

(PPG) polyether polyol (polyoxypropylene glycol, Mw: 15,000, product name: Preminol S4015, manufactured by Asahi glass Co., Ltd.)

(Polymer A1) polyoxyalkylene Polymer A1 synthesized in Synthesis example 1

(Polymer A2) polyoxyalkylene Polymer A2 synthesized in Synthesis example 2

(Polymer A3) (meth) acrylic Polymer A3 having trimethoxysilyl group, synthesized in Synthesis example 3

[ component C: photoinitiator (C)

(IRGACURE379)2- (dimethylamino) -2- [ (4-methylphenyl) methyl ] -1- [4- (4-morpholinyl) phenyl ] -1-butanone (product name: IRGACURE379 EG, manufactured by BASF)

(IRGACURE TPO)2,4, 6-trimethyl-benzoyl-diphenyl-phosphine oxide (product name: IRGACURE TPO, manufactured by BASF corporation)

[ component D: tackifying resins ]

(YS Polystar K125) terpene phenol (terpene phenol) copolymer (SP value 9.32, softening point 125 ℃ C., product name: YS Polystar K125, Yasuhara Chemical Co., Ltd.; manufactured by Ltd.)

[ component E: polyfunctional (meth) acrylates ]

(UV3300B) photoradically vinyl group-containing polyfunctional Polymer (urethane acrylate, Mw: 13,000, Tg: 30 ℃ C., number of functional groups: 2, product name: UV3300B, manufactured by Nippon synthetic chemical Co., Ltd.)

[ Compound having Si-F bond ]

(fluorinated Polymer) fluorinated Polymer synthesized in Synthesis example 4

(BF₃-MEA) boron trifluoride monoethylamine

(Peel Strength test)

The photocurable adhesive according to example 1 was applied to the 1 st adherend (adherend) (PET film) using a glass rod. The thickness of the photocurable adhesive was 250. mu.m. Next, the photocurable adhesive on the 1 st adherend was irradiated with Ultraviolet (UV) [ irradiation conditions: UV-LED lamp (wavelength 365nm, illumination: 1000 mW/cm)²) And integrated light quantity: 3000mJ/cm²]. Immediately after the UV irradiation, the 2 nd adherend (adherend made of polymethyl methacrylate resin (PMMA)) was bonded to the 1 st adherend with the UV-irradiated photocurable adhesive interposed therebetween in an area of 25mm × 80mm, and a pressure was applied using a 2kg roller. After the application of the pressure, the peel strength was measured at a test speed of 300 mm/min in accordance with JIS K6854-2 (adhesive-peel adhesion strength test method 2: 180 degree peel method). The test results are shown in Table 1. The unit of peel strength in Table 1 is "N/25 mm".

(surface curability (touch test))

The photocurable adhesive according to example 1 was applied to an adherend (PE) using a glass rodT film). The thickness of the photocurable adhesive was 250. mu.m. Next, the photocurable adhesive on the adherend was irradiated with Ultraviolet (UV) [ irradiation conditions: UV-LED lamp (wavelength 365nm, illumination: 1000 mW/cm)²) And integrated light quantity: 3000mJ/cm²]. Immediately after the UV irradiation, the surface curability was tested by finger touch in an environment of 23 ℃ and 50% RH in a dark room. The test results are shown in Table 1. In table 1, the case where no uncured material was adhered to the finger was indicated by "o", the case where the uncured material was slightly adhered by "Δ", the case where the liquid material remained on the surface of the finger was indicated by "x", and the case where the liquid material was not cured was indicated by "uncured".

(examples 2 to 6 and comparative examples 1 to 6)

A photocurable adhesive was obtained in the same manner as in example 1 except that the compounded material was changed as shown in table 1, and then the properties of the obtained photocurable adhesive were evaluated in the same manner as in example 1. The results are shown in Table 1.

As shown in table 1, the photocurable adhesive according to the examples can be cured in a short time, and exhibits excellent initial adhesion. Further, the photocurable adhesive involved in the examples showed excellent peel strength. In comparative example 6, although curing was performed in the surface curing test, no tackiness was observed.

(example 7)

Photocurable adhesives that were readily post-cured were prepared in the same manner as in example 1 at the compounding ratios shown in table 2.

TABLE 2

In table 2, the unit of the compounded amount of each compounded substance is "g". The details of the compounding agent are as follows. Further, A component B, A component C, A component D, A component E, A fluorinated polymer and BF are excluded from ECA, KBM5103, P-EO-A and 4HBA₃Any of which is the same as table 1.

(2HPPA-PGA) acrylic acid 2-hydroxy-3-phenoxypropyl ester (product name: PGA, first Industrial pharmaceutical Co., Ltd.)

(ECA) Ethyl Carbitol acrylate (product name: Viscoat #190, manufactured by Osaka organic chemical industry Co., Ltd.)

(KBM5103)3- (trimethoxysilyl) propyl acrylate (trade name: KBM5103, manufactured by shin-Etsu chemical Co., Ltd.)

(PP-EO-A) O-phenylphenol EO-modified acrylate (product name: ORD-01, manufactured by Nippon catalyst Co., Ltd.)

(4HBA) 4-hydroxybutyl acrylate (brand: 4HBA, manufactured by Osaka organic chemical Co., Ltd.)

(YS Polystar T130) terpene phenol copolymer (SP value 8.81, softening point 130 ℃ C., product name: YS Polystar T130, Yasuhara Chemical Co., Ltd., manufactured by Ltd.)

(UV3700B) a photoradically vinyl-containing polyfunctional polymer; (urethane acrylate, Mw: 38,000, Tg: 6 ℃ C., functional group number: 2, product name: UV3700B, manufactured by Nippon synthetic chemical Co., Ltd.)

(photo-aminosilane) Compound F1 was produced from the photo-aminosilane synthesized in Synthesis example 5

(Peel adhesion Strength test)

The photocurable adhesive according to example 7 was applied to the 1 st adherend (PET film) using a glass rod. The thickness of the photocurable adhesive was 200. mu.m. Next, the photocurable adhesive on the 1 st adherend was irradiated with Ultraviolet (UV) [ irradiation conditions: UV-LED lamp (wavelength 365nm, illumination: 1000 mW/cm)²) And integrated light quantity: 3000mJ/cm²]. Immediately after the UV irradiation, a2 nd adherend (an adherend made of aluminum treated with a sulfuric acid anodic oxide film (sulfuric acid アルマイト)) was bonded to a1 st adherend with a UV-irradiated photocurable adhesive interposed therebetween in an area of 25mm × 80mm, and pressure was applied using a 2kg roller. After applying pressure, the test was conducted at a test speed in accordance with JIS K6854-2 (adhesive-peel adhesion Strength test method No. 2: 180 degree peel method)The peel strength was measured at 300 mm/min. The test results are shown in the column "peel test 1" in table 2.

In the same manner as described above, immediately after the UV irradiation, the 2 nd object to be bonded was bonded to the 1 st object to be bonded so as to sandwich the UV-irradiated photocurable adhesive, and then the bonded was pressed (press-bonded) using a 2kg roller and cured at 23 ℃ and 50% RH for 7 days, thereby producing a cured sample. In addition, the peel strength of the sample was measured in the same manner as described above. The test results are shown in the column "peel test 2" in table 2. The unit of peel adhesion strength in Table 2 is "N/25 mm".

(shear adhesion Strength test)

The photocurable adhesive according to example 7 was applied to the 1 st adherend (an aluminum adherend subjected to sulfuric acid anodic oxidation coating treatment) using a glass rod. The thickness of the photocurable adhesive was 200. mu.m. Next, the photocurable adhesive on the 1 st adherend was irradiated with Ultraviolet (UV) [ irradiation conditions: UV-LED lamp (wavelength 365nm, illumination: 1000 mW/cm)²) And integrated light quantity: 3000mJ/cm²]. Immediately after the UV irradiation, a2 nd adherend (an aluminum adherend subjected to a sulfuric acid anodic oxide film treatment) was bonded to the 1 st adherend with a UV-irradiated photocurable adhesive interposed therebetween over an area of 25mm × 25mm, and pressure was applied using a small-sized large iron clip (bulldog clip). After the pressure was applied, the tensile shear adhesion strength was measured at a test speed of 50 mm/min in accordance with the tensile shear adhesion strength test method for JIS K6850 rigid adherend. The test results are shown in the column "shear test 1" in table 2.

In the same manner as described above, immediately after the UV irradiation, the 2 nd adherend was bonded to the 1 st adherend so as to sandwich the UV-irradiated photocurable adhesive therebetween, and fixed by applying pressure using a small-sized large iron clamp, and cured at 23 ℃ and 50% RH for 7 days, thereby producing cured samples. In addition, the tensile shear adhesion strength was measured in the same manner as described above with respect to this sample. Will test the knotThe results are shown in table 2 under the column "shear test 2". The tensile shear bond strength in Table 2 is expressed in the unit of "N/mm²”。

In the peel test and the shear test in table 2, the results determined according to the following criteria are shown by predetermined symbols.

"peeling test 1 (immediately after irradiation)": the peel adhesion strength was 5N/25mm or more and described as "excellent", 1N/25mm or more and described as "O", and less than 1N/25mm and described as "X".

"peeling test 2 (curing for 7 days)": the peel adhesion strength was 10N/25mm or more and described as "excellent", the peel adhesion strength was 3N/25mm or more and described as "good", and the peel adhesion strength was less than 3N/25mm and described as "poor".

"shear test 1 (immediately after irradiation)": the tensile shear bonding strength is 0.4N/mm²The above is described as ". circlein", 0.2N/mm²The above results are described as "O", and the value is less than 0.2N/mm²In the case of (2), the description is "X".

"shear test 2 (curing for 7 days)": the tensile shear bonding strength is 1N/mm²The above is described as ". circinatus" 0.5N/mm²The above results are described as "O", and the value is less than 0.5N/mm²In the case of (2), the description is "X".

(examples 8 to 15 and comparative examples 7 to 10)

A photocurable adhesive that was easily post-cured was obtained in the same manner as in example 7, except that the compounded material was changed as shown in table 2, and then the properties of the obtained photocurable adhesive were evaluated in the same manner as in example 7. The results are shown in Table 2. In addition, "0" in the measurement values of the evaluations (the peeling tests 1 and 2 and the shear tests 1 and 2) of the comparative example 10 indicates that the surface was insufficiently cured (that is, slightly slippery was present when touched with a finger), and that the adhesiveness and the adhesiveness were not exhibited.

As shown in table 2, the photocurable adhesives described in the examples exhibited excellent adhesion immediately after UV irradiation and exhibited excellent adhesion with time.

(LED chip bonding test)

Fig. 1(a) and (b) show an outline of a printed board and an LED chip used in an LED chip bonding test. Fig. 2 shows an outline of a process of bonding the LED chip to the printed board. 3 fig. 32 3 is 3 described 3 using 3 a 3 section 3 a 3- 3 a 3 in 3 fig. 3 1 3. 3 Fig. 1 and 2 are schematic diagrams, and do not correspond to actual shapes and sizes.

In this test, a bonding test of the LED chip was performed using the photocurable adhesive according to example 1. Specifically, first, the printed board 10 shown in fig. 1(a) and 2(a) is prepared, and the printed board 10 is printed with the wiring pattern 12 and the wiring pattern 14 formed of copper, the mounting portion 16 and the mounting portion 18 formed of copper, and the terminal electrode 20 and the terminal electrode 22 formed of copper. An LED chip 30 (product model: HT17-21SRWC, manufactured by Linkman corporation, emission wavelength at a forward current of 20 mA: 624nm to 630nm) as shown in FIG. 1(b) was prepared. The LED chip 30 includes: the LED package includes a chip substrate 32, an LED element (not shown) mounted on the chip substrate 32, a connection electrode 34 electrically connected to an anode electrode of the LED element and provided at one end of the chip substrate 32, a connection electrode 36 electrically connected to a cathode electrode of the LED element and provided at the other end of the chip substrate 32, and a sealing portion 38 sealing the LED element.

Next, the metal mask 40 having the opening 40a is provided on the printed substrate 10. Specifically, as shown in fig. 2(b), the metal mask 40 is provided on the printed board 10 so as to correspond to the opening 40a in the mounting portions 16 and 18 of the printed board 10. Then, a moisture-curable conductive adhesive layer 42 and a moisture-curable conductive adhesive layer 44, which are formed of a moisture-curable conductive adhesive (modified (poly) siloxane-based product name: SX-ECA48, cemidine co., ltd.) (see fig. 2(c)), were formed by screen printing. The thickness of the moisture-curable conductive adhesive layer 42 and the moisture-curable conductive adhesive layer 44 was set to 115 μm.

Next, as shown in fig. 2(d), the photocurable adhesive 46 according to example 1 was applied by a dispenser (dispenser) with a thickness of 100 μm between the mounting portion 16 and the mounting portion 18 of the printed circuit board 10. Then, Ultraviolet (UV) rays were irradiated to the photocurable adhesive 46 on the printed board 10 (irradiation conditions: UV-LED lamp (wavelength: 365nm, illuminance: 1000 mW/cm)²) And irradiation time: 3 seconds)). Immediately after the UV irradiation, the LED chip 30 is mounted on the printed substrate 10 as shown in fig. 2 (e). In this case, the connection electrode 34 is attached to the moisture-curable conductive adhesive layer 42 on the mounting portion 16, and the connection electrode 36 is attached to the moisture-curable conductive adhesive layer 44 on the mounting portion 18, so that the photocurable adhesive 46 is in contact with the bottom of the LED chip 30 except for the connection electrode 34 and the connection electrode 36.

Immediately after mounting, a force is applied to the LED chip 30 (the direction of the applied force is a shear direction). As a result, it was confirmed that the LED chip 30 was sufficiently fixed to the printed board 10.

After that, the moisture-curable conductive adhesive layer 42 and the moisture-curable conductive adhesive layer 44 were cured while being left at 23 ℃ and 50% RH for 24 hours, and then a current of 20mA was applied to the LED chip 30 through the terminal electrode 20 and the terminal electrode 22, and it was confirmed that the LED chip 30 emitted red light.

Although the embodiments and examples of the present invention have been described above, the embodiments and examples described above are not limited to the inventions described in the patent claims. In addition, the following two points should be noted: all combinations of the features described in the embodiments and examples are not limited to the combinations necessary for solving the problems of the invention; and various modifications can be made without departing from the technical idea of the present invention.

Description of the reference numerals

10 printed circuit board

12. 14 wiring pattern

16. 18 mounting part

20. 22 terminal electrode

30 LED chip

32 chip substrate

34. 36 connecting electrode

38 seal part

40 Metal mask

40a opening part

42. 44 moisture-curable conductive adhesive layer

46 photo-curable adhesive.

Claims (6)

1. A bonding method for bonding a plurality of adherends, the bonding method comprising the steps of:

a coating step of applying a photocurable adhesive exhibiting adhesiveness by light irradiation to at least one adherend,

a light irradiation step of irradiating the photocurable adhesive applied to the one adherend with light in the presence of oxygen, and

a bonding step of bonding another adherend to the photocurable adhesive applied to the one adherend and irradiated with the light, wherein a protective sheet having a pressure-sensitive adhesive surface removed as the other adherend,

the photocurable adhesive contains:

(A) a monoacrylate represented by the following general formula (1),

at least one organic compound selected from the group consisting of (B1) monofunctional (meth) acrylates and (B2) liquid organic polymers, and

(C) a photo-initiator,

in the general formula (1), R¹Represents a hydrogen atom or a methyl group, R²To R⁶Each independently is a hydrogen atom or a substituent;

the (B1) monofunctional (meth) acrylate is a compound selected from the group consisting of a long-chain hydrocarbon (meth) acrylate having 8 to 20 carbon atoms and a compound represented by the following general formula (2);

CH₂＝CR^αCOO(C_mH_2mO)_nR^β···(2)

in the general formula (2), R^αis-H or-CH₃M is an integer of 2 to 4, n is an integer of 1 to 20, R^βrepresents-H or unsubstituted or substituted alkyl, unsubstituted or substituted phenyl;

the liquid organic polymer (B2) is a liquid organic polymer that exhibits a liquid state at 20 ℃ and is selected from the group consisting of a polyoxyalkylene polymer and a liquid organic polymer containing a crosslinkable silyl group.

2. The bonding method according to claim 1, wherein the photocurable adhesive further comprises (D) a tackifier resin.

3. The bonding method according to claim 1 or 2, wherein the photocurable adhesive further comprises (E) a compound containing 2 or more photoradically polymerizable vinyl groups.

4. The bonding method according to claim 3, wherein the compound (E) containing 2 or more photo radical polymerizable vinyl groups is a polymer.

5. An adhesive body produced by using the adhesive method according to any one of claims 1 to 4.

6. A photocurable adhesive for field construction, which exhibits adhesion by irradiation with light in the presence of oxygen,

the photocurable adhesive for field construction comprises:

(A) a monoacrylate represented by the following general formula (1),

at least one organic compound selected from the group consisting of (B1) monofunctional (meth) acrylates and (B2) liquid organic polymers, and

(C) a photo-initiator,

in the general formula (1), R¹Represents a hydrogen atom or a methyl group, R²To R⁶Each independently is a hydrogen atom or a substituent;

the (B1) monofunctional (meth) acrylate is a compound selected from the group consisting of a long-chain hydrocarbon (meth) acrylate having 8 to 20 carbon atoms and a compound represented by the following general formula (2);

CH₂＝CR^αCOO(C_mH_2mO)_nR^β···(2)

in the general formula (2), R^αis-H or-CH₃M is an integer of 2 to 4, n is an integer of 1 to 20, R^βrepresents-H or unsubstituted or substituted alkyl, unsubstituted or substituted phenyl;

the liquid organic polymer (B2) is a liquid organic polymer that exhibits a liquid state at 20 ℃ and is selected from the group consisting of a polyoxyalkylene polymer and a liquid organic polymer containing a crosslinkable silyl group.

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