JP6798622B2 - Method for manufacturing a laminate containing a curable bonding material - Google Patents

Description

The present invention relates to a method for manufacturing a laminated body using a bonding material that can be used for laminating members used in an image display device.

In recent years, liquid crystal display devices have been widely used as display devices for televisions, smartphones, personal assistant devices (PADs), tablet computers, car navigation systems, and the like.

The liquid crystal display device generally includes a liquid crystal display panel, a planar lighting device (backlight device) arranged on the back surface of the liquid crystal display panel to illuminate the liquid crystal display panel, a circuit board (board), and other electronic components. It is known that the chassis to which the liquid crystal is mounted and a member such as a heat sink for diffusing heat generated from the components are laminated.

In order to stack the members of the liquid crystal display device, usually, for the purpose of firmly fixing the members to each other and preventing the members from falling off over time, an epoxy adhesive is used between the members. , A method of joining two members to each other by interposing a joining layer composed of an adhesive such as a urethane-based adhesive is often used (see, for example, Patent Document 1).

Further, in the method of joining the members to each other, for example, when the surface of the members to be laminated has bending or unevenness, an adhesive is applied, and after the adhesive is made to follow the bending or unevenness, the thickness unevenness of the coated surface is caused. In order to remove the adhesive, the surface to which the adhesive is applied is smoothed by squeezing the applied adhesive, and then the other member is laminated (see, for example, Patent Document 2).

In the current production, it is necessary to use an adhesive having a long curing time in order to secure the construction time required for the above-mentioned laminating process. As a result, a step of curing for a long time was required until the adhesive after the above-mentioned laminating step exhibited sufficient bonding strength.

Heat curing of the adhesive was also considered as a means for accelerating the progress of curing of the adhesive after the laminating step, but there was a risk that the members of the liquid crystal display device would be damaged by the heat during curing. In addition, due to the difference in thermal expansion of each member, there are problems such as deformation of the member due to strain between the members generated when cooling, cracks between the joining material and the member, and peeling, so an adhesive is used. There was a problem in the joining method.

Further, in order to shorten the curing time, if an adhesive having excellent curability at room temperature is used, the construction time required for the above-mentioned laminating step cannot be secured, and the curing proceeds before laminating. Occasionally, sufficient bonding strength was not developed.

In addition, as a means to complete curing at low temperature in a short time, a joining method by irradiating light was also studied, but it could not be used for a member that cannot transmit light, the applicable members were limited, and it was difficult to put it into practical use. ..

From the above background, there is a strong demand for a new joining method that can be completed in a short time and at a low temperature and can be suitably joined to a light-impermeable material.

Japanese Patent No. 5546136 Japanese Unexamined Patent Publication No. 2003-136677

The problem to be solved by the present invention is to provide a new method for producing a laminated body, which can be completed in a short time and at a low temperature and can be suitably bonded to a light-impermeable material. is there.

As a result of diligent research focusing on a method for producing a laminate, the present inventors have found that the above-mentioned problems can be solved by a production method having the following steps [1] to [3], and the present invention has been developed. It came to be completed.

That is, the present invention is a method for producing a laminate containing an adherend (C1) and a bonding material (X), which comprises a step [1] of activating a reactive site of the bonding material (X) and an adherend. This is a manufacturing method including a step [2] of attaching to (C1) and a step [3] of curing the bonding material (X) in this order.

In the present invention, since the reactive portion of the bonding material (X) is activated, the curing reaction of the bonding material (X) can proceed in a short time and at a low temperature.

In the present invention, since the reactive portion of the bonding material (X) can be activated and then attached to the adherend (C1), it can be applied to various members such as members that cannot transmit light. Is possible.

The production method of the present invention is a method for producing a laminate containing an adherend (C1) and a bonding material (X), and includes a step [1] of activating a reactive site of the bonding material (X) and bonding. This is a manufacturing method including a step [2] of attaching the material (X) to the adherend (C1) and a step [3] of curing the bonding material (X) in this order.

In the production method of the present invention, since the reaction site of the bonding material (X) is activated and then attached to the adherend (C1), curing proceeds in a state where the reactivity of the bonding material (X) is enhanced. Can be done. This makes it possible for the curing to proceed at a low temperature as compared with the non-activated state. In addition, the curing can proceed in a short time as compared with the non-activated state.

In the production method of the present invention, in step [1], the step of activating the reactive site of the bonding material (X) is performed, and the bonding material (X) has a reactive site in the material. This reactive site refers to a site that is activated by giving an external stimulus and becomes ready to react with another site.

The means for activating the reactive site of the bonding material (X) includes, but is not limited to, heat, light, humidity, etc., but it is preferable to use heat or light, and it is more preferable to use light. preferable. The bonding material (X) activated by light has good storage stability and can activate the reactive site at a low temperature. Further, the external stimulus may be used alone or in combination of two or more.

As means for activating the reaction site with the light, photoradical polymerization, photocationic polymerization, photoanimation

On-polymerization can be mentioned, but the use of photocationic polymerization or photoanionic polymerization does not hinder oxygen during curing, the reaction proceeds continuously even after irradiation with light, and a member that does not transmit light. However, it is also preferable because the bonding material can be laminated with the adherend after being irradiated with light. Further, it is more preferable to use photocationic polymerization because it has excellent reactivity at the time of light irradiation and high bondability after curing can be easily obtained. Further, these polymerization methods may be used alone or in combination of two or more.

Further, the manufacturing method of the present invention is a method for manufacturing a laminated body in which an adherend (C1) and an adherend (C2) are included via a bonding material (X), and the adhering material (X) is included in the adherend. The step [01] of sticking to (C2), the step [1] of activating the reactive portion of the bonding material (X), the step [2] of sticking to the adherend (C1), and the bonding material. Step [3] in which (X) is cured is included in this order, and step tracking is performed in at least one of the steps [01] and [1] and between the steps [2] and [3]. It is a manufacturing method including the step (curing step) [02].

In the step of following the step in the step [02], the bonding material (X) is attached to the adherend (C1) and / or the adherend (C2) having bending and / or unevenness. Then, a step of filling the bending and / or unevenness is performed.

In the step [02], curing is started by going through the step [1] for activating the reactive site of the bonding material (X) described above, so that one of the adherends to be bonded by this production method is used. When the bending and / or unevenness is present in the step [02], the step [02] is performed in order to secure a sufficient time (curing time) for the bonding material to follow the bending and / or unevenness. ] And before the step [1].

The step [01] may include a step of heating as long as the members to be laminated are not damaged or the bonding material is not excessively deformed and flows. By including the heating step, when the bonding material (X) is attached to the adherend (C2), it adheres more firmly and a high bonding strength can be obtained.

In the step [01], the heating temperature is preferably 10 ° C. or higher and 150 ° C. or lower, more preferably 20 ° C. or higher and 120 ° C. or lower, further preferably 30 ° C. or higher and 100 ° C. or lower, and most preferably 40 ° C. or higher and 90 ° C. or lower. Within the above range, damage to the member can be suppressed, excessive deformation of the bonding material can be suppressed, and the bonding can be more firmly adhered to obtain high bonding strength.

The step [02] may include a step of heating as long as the members to be laminated are not damaged or the bonding material is not excessively deformed and flows. By including the heating step, when the bonding material (X) follows the step of the adherend (C2), the time required for following the step of the bonding material (X) is shortened, and the production of the present invention is performed. The method can be completed in a short time.

In the step [02], the heating temperature is preferably 20 ° C. or higher and 150 ° C. or lower, more preferably 40 ° C. or higher and 120 ° C. or lower, further preferably 55 ° C. or higher and 100 ° C. or lower, and most preferably 70 ° C. or higher and 90 ° C. or lower. Within the above range, it is possible to follow the step while suppressing damage to the members to be laminated and excessive deformation of the joint material when following the step.

The step [2] is preferably performed within 24 hours, more preferably within 12 hours, further preferably within 3 hours, and within 1 hour after the step [1] is performed. Most preferably done. Within the above range, when the bonding material (X) is attached to the adherend (C1), the bonding material (X) adheres more firmly and a high bonding strength can be obtained.

In the step [2], the members may be attached while being heated as long as the members to be laminated are not damaged, the members are not deformed due to strain between the members, or cracks are not generated between the joining material and the members. Good. By including the heating step, when the bonding material (X) is attached to the adherend (C1), it adheres more firmly and a high bonding strength can be obtained.

In the step [2], the heating temperature is preferably 10 ° C. or higher and 150 ° C. or lower, more preferably 20 ° C. or higher and 120 ° C. or lower, further preferably 30 ° C. or higher and 100 ° C. or lower, and most preferably 40 ° C. or higher and 80 ° C. or lower. Within the above range, damage to the member can be suppressed, excessive deformation of the bonding material can be suppressed, and the bonding can be more firmly adhered to obtain high bonding strength.

The step [3] includes a step of curing the bonding material (X). By curing the bonding material (X), the bonding material (X) and the adherend (C1) are more firmly adhered to each other, and high bonding strength can be obtained.

The step [3] may include a step of heating as long as the members to be laminated are not damaged or strain is generated between the members to deform the members or cracks are not generated between the joining material and the members. Good. By including the heating step, the time required for curing the bonding material (X) after laminating the bonding material (X) and the adherend (C1) is shortened, and the production method of the present invention can be obtained. It can be completed in a short time.

In the step [3], the heating temperature is preferably 20 ° C. or higher and 150 ° C. or lower, more preferably 40 ° C. or higher and 120 ° C. or lower, further preferably 55 ° C. or higher and 100 ° C. or lower, and most preferably 70 ° C. or higher and 90 ° C. or lower. Within the above range, damage to the members can be suppressed, and deformation of the members due to strain between the members and cracks generated between the joining material and the members can be prevented.

In the step [01], the bonding material (X) preferably has a storage elastic modulus in the range of 5.0 × 10 ³ Pa or more, and 5.0 × 10 ⁴ Pa to 1.0 ×. more preferably in the range of 10 ^8, more preferably ^{5.0 × 10 5 Pa~1.0 × 10 7} Pa. By setting the range to the above range, it is possible to facilitate the handling of the joint material before curing and to prevent the joint material from being deformed and flowing.

Further, as the bonding material (X), in the step [02], the storage elastic modulus of the bonding material (X) at the time of following a step is preferably less than 5.0 × 10 ³ Pa, and 1.0 × It is more preferably 10 ³ Pa or less, and further preferably 1.0 × 10 ² Pa or less. Within the above range, it is possible to obtain a bonding material having further improved followability to the stepped portion.

The storage elastic modulus of the bonding material (X) at 25 ° C. after the step [3] is preferably 1.0 × 10 ⁵ Pa or more, more preferably 1.0 × 10 ⁶ Pa or more. It is more preferably × 10 ⁸ Pa or more. Within the above range, the bonding strength of the cured product of the bonding material (X) can be further improved.

The storage elastic modulus of the bonding material (X) is a numerical value measured at a frequency of 1.0 Hz.

As the bonding material (X) used in the production method of the present invention, a composition containing a polymerizable compound or the like described later can be used, and the polymerizable compound is particularly produced if polymerization is induced by an external stimulus. There is no limitation.

As the bonding material (X), it is preferable to use a material previously molded into a sheet shape because it is easy to handle before curing and its thickness can be easily adjusted.

As the sheet-shaped bonding material, it is preferable to use a material having a thickness in the range of 50 to 2000 μm, more preferably 100 to 1000 μm, and most preferably 200 to 800 μm. preferable. Within the above range, the handleability before curing is excellent, and it is possible to follow the surface of the adherend having steps such as unevenness and bending.

The polymerizable compound preferably contains a thermopolymerizable compound and a photopolymerizable compound, but it is preferable to use the photopolymerizable compound for storage stability prior to the production step [1] of the bonding material (X). It is more preferable because the property is improved and the reactive site can be activated at a low temperature.

Examples of the photopolymerizable compound include a photoradical polymerizable compound, a photocationic polymerizable compound, and a photoanionic polymerizable compound. These may be used alone or in combination, but the use of a photocationically polymerizable compound or a photoanionic polymerizable compound does not cause oxygen inhibition during curing and continues even after light irradiation. Further, it is preferable that the bonding material is irradiated with light and then laminated with the adherend, so that the bonding material can be laminated even on a member that does not transmit light. Further, it is more preferable to use a cationically polymerizable compound because it has excellent reactivity after light irradiation and high bondability after curing can be easily obtained.

The cationically polymerizable compound is not particularly limited as long as it has one or more cationically polymerizable functional groups in one molecule. The photocationically polymerizable compound shall have one or more cationically polymerizable functional groups such as an epoxy group, an oxetanyl group, a hydroxyl group, a vinyl ether group, an episulfide group, an ethyleneimine group and an oxazoline group in one molecule. Is preferable. Above all, a cationically polymerizable compound having an epoxy group is more preferable in order to obtain high curability and bonding strength after curing.

As the epoxy resin, a compound having one or more epoxy groups in one molecule can be used. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, polyhydroxynaphthalene type epoxy resin, isocyanate-modified epoxy resin, 10- (2,5-dihydroxyphenyl) ) -9,10-Dihydro 9-oxa-10-phosphophenanthrene-10-oxide-modified epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, hexanediol type epoxy resin, triphenylmethane type epoxy resin, tetra Phenylethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin, naphthol novolac type epoxy resin, naphthol aralkyl type epoxy resin, naphthol-phenol co-condensed novolac type epoxy resin, naphthol-cresol co-condensed Novolak type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resin, biphenyl modified novolac type epoxy resin, trimethylolpropan type epoxy resin, alicyclic epoxy resin, acrylic resin having epoxy group, polyurethane having epoxy group A resin, a polyester resin having an epoxy group, an epoxy resin having flexibility, and the like can be used.

Among them, when the alicyclic epoxy resin or the polyfunctional aliphatic epoxy resin is used as the epoxy resin, the cationically polymerizable property is excellent, so that a bonding material having excellent curability can be obtained.

Further, other resin components and the like may be blended or added to these to increase the flexibility, and the adhesive force and the bending force may be improved. As such a modified product, CTBN (terminal) is used. Carboxyl group-containing butadiene-acrylonitrile rubber) modified epoxy resin; epoxy resin in which various rubbers such as acrylic rubber, NBR, SBR, butyl rubber, or isoprene rubber are dispersed in resin; epoxy resin modified with liquid rubber as described above; acrylic , Urethane, urea, polyester, styrene and other epoxy resins added; chelate-modified epoxy resin; polyol-modified epoxy resin and the like can be used.

Specific examples of the photocationically polymerizable compound having a cationically polymerizable functional group other than the epoxy group include 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene and 1,4-bis [(. 3-Methyl-3-oxetanylmethoxy) methyl] benzene, 3-methyl-3-glycidyloxetane, 3-ethyl-3-glycidyloxetane, 3-methyl-3-hydroxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane , Oxetane compounds such as di {1-ethyl (3-oxetanyl)} methyl ether and the like.

As the bonding material (X) used in the production method of the present invention, a material containing other components in addition to the above-mentioned polymerizable compound can be used.

As the bonding material (X) used in the production method of the present invention, it is preferable to use a polymerization initiator capable of reacting with the polymerizable compound.

The polymerization initiator may be one that is activated by an external stimulus. For example, when a cationically polymerizable compound is used as the polymerizable compound, a functional group capable of reacting with a cationically polymerizable functional group. It is preferable to use the one having.

Further, the polymerization initiator includes a photopolymerization initiator and a thermal polymerization initiator, which may be used alone or in combination of two. Above all, in order to obtain a reaction at a low temperature and a good curing reaction, it is preferable to use a photopolymerization initiator in which the reaction proceeds by light as an external stimulus. As a result, high bonding strength can be obtained without damaging the members to be laminated, deforming the members due to strain between the members, or causing cracks between the bonding material and the members.

As the light, appropriate light such as ultraviolet light or visible light can be used, but it is preferable to use light having a wavelength of 300 nm or more and 420 nm or less.

The photopolymerization initiator may be any one that is activated by light, and examples thereof include a photoradical polymerization initiator, a photocationic polymerization initiator, and a photoanionic polymerization initiator. For example, the photopolymerizable compound is light. When a cationically polymerizable compound is used, it is preferable to use a photocationic polymerization initiator.

The photocationic polymerization initiator is not particularly limited as long as it can induce a ring-opening reaction of a cationically polymerizable functional group with light having a wavelength of 300 to 370 nm, but it is cationically polymerized with light having a wavelength of 300 to 370 nm. Compounds that induce a ring-opening reaction of a sex functional group and are inactive in a wavelength region exceeding 370 nm are preferably used. Such compounds include, for example, aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfoniums. Examples include onium salts such as salts.

Specific examples of such onium salts include, for example, Optomer SP-150, Optomer SP-170, Optomer SP-171 (all manufactured by ADEKA), UVE-1014 (manufactured by General Electronics), OMNICAT250, OMNICAT270 (all of which are manufactured by ADEKA). IGM Resin), IRGACURE290 (BASF), Sun Aid SI-60L, Sun Aid SI-80L, Sun Aid SI-100L (all manufactured by Sanshin Chemical Industry Co., Ltd.), CPI-100P, CPI-101A, CPI-200K (Both are manufactured by Sun Appro) and the like.

The photocationic polymerization initiator may be used alone or in combination of two or more. Further, a plurality of photocationic polymerization initiators having different effective active wavelengths may be used for two-step curing.

The photocationic polymerization initiator may be used in combination with an anthracene-based or thioxanthone-based sensitizer, if necessary.

The blending ratio of the photocationic polymerization initiator is preferably in the range of 0.001 part by mass to 30 parts by mass, and 0.01 to 20 parts by mass with respect to 100 parts by mass of the photocationic polymerization initiator. It is preferably used in the range, and more preferably in the range of 0.1 parts by mass to 10 parts by mass. If the blending ratio of the photocationic polymerization initiator is too small, the curing required for developing high bonding strength will be insufficient, and if it is too large, the curability will be improved, but the time required for application after irradiation with light will be improved. It can be too short.

As the bonding material (X), it is preferable to use an adhesive resin having a weight average molecular weight in the range of 2000 to 2000000 because it is easy to handle before curing and its thickness can be easily adjusted. The more preferable range of the weight average molecular weight is 5000 to 1,000,000, and the more preferable range of the weight average molecular weight is 5000 to 800000. If the weight average molecular weight is too small, the cohesive force of the bonding material before curing is insufficient, and the bonding material exudes over time, resulting in poor handleability. Further, if the weight average molecular weight is too large, the compatibility with the polymerizable compound may decrease.

Examples of the adhesive resin include polyester, polyurethane, poly (meth) acrylate and the like. These adhesive resins may be a homopolymer or a copolymer. Further, these adhesive resins may be used alone or in combination of two or more.

It is preferable that the adhesive resin has adhesiveness at room temperature because the adhesiveness when laminating the bonding material on the adherend is improved. In order to impart the adhesiveness of the adhesive resin, the glass transition temperature of the adhesive resin is preferably in the range of -40 to 20 ° C, more preferably in the range of -30 to 10 ° C. .. When the glass transition temperature is within the above range, the pressure-sensitive adhesive layer can be imparted with adhesiveness and a high elastic modulus can be imparted, and the bonding strength of the bonding material can be improved. The glass transition temperature of the adhesive resin is measured by using, for example, a dynamic viscoelasticity tester (manufactured by Leometrics, trade name: Ares 2KSTD) between the parallel disks, which is the measurement unit of the tester. Can be calculated as the temperature at which the loss tangent (Tan δ), which can be calculated by measuring the storage elastic modulus (G') and the loss elastic modulus (G ″) at a frequency of 1.0 Hz, becomes the maximum value.

Since the adhesive resin may be crosslinked, a functional group capable of reacting with a crosslinking agent or a functional group contained in the polymerizable compound may be introduced. Examples of the functional group include a hydroxyl group, a carboxyl group, an epoxy group, an amino group and the like, and it is preferable to select them in a timely manner as long as the above-mentioned polymerizable compound does not inhibit the polymerization.

The adhesive resin is preferably used in the range of 5 parts by mass to 900 parts by mass, preferably in the range of 10 to 700 parts by mass, and 20 parts by mass to 20 parts by mass with respect to 100 parts by mass of the curable resin. It is more preferable to use it in the range of 400 parts by mass. If the blending ratio of the adhesive resin is too large, the curing required for developing high bonding strength is insufficient, and the handling before curing is improved if the amount is too small, but the strength required for bonding may decrease.

As the bonding material (X), it is preferable to use a material previously molded into an arbitrary shape such as a sheet as described above. In order to improve the work efficiency when molding the composition containing the polymerizable compound or the like into the sheet shape or the like, the composition contains a solvent in addition to the polymerizable compound or the polymerization initiator. It is preferable to do so.

Examples of the solvent include ester solvents such as methyl acetate, ethyl acetate, propyl acetate and butyl acetate; ketone solvents such as acetone, methyl ketyl ketone, methyl isobutyl ketone, diisobutyl ketone and cyclohexanone; aromatics such as toluene and xylene. A hydrocarbon solvent or the like can be used.
"

Further, as the bonding material (X), a material containing other components can be used. As the other components, for example, fillers such as aluminum hydroxide, aluminum oxide, aluminum nitride, magnesium hydroxide, magnesium oxide, mica, talc, boron nitride, and glass flakes can be used.

Further, as the bonding material (X), in addition to the above-mentioned ones, for example, a filler, a softening agent, a stabilizer, an adhesion accelerator, a leveling agent, a defoaming agent, and a plasticizer, as long as the effects of the present invention are not impaired. , Adhesive-imparting resins, fibers, antioxidants, UV absorbers, antioxidants, thickeners, colorants such as pigments, and additives such as fillers can be used.

The bonding material (X) of the present invention can be produced by mixing the polymerizable compound with an arbitrary component such as the polymerization initiator and the solvent.
When the above-mentioned components are mixed to produce the bonding material (X), a dissolver, a butterfly mixer, a BDM twin-screw mixer, a planetary mixer, or the like can be used, if necessary, and a dissolver or a butterfly mixer should be used. When the conductive fillers are used, it is preferable to use a planetary mixer in order to improve their dispersibility.

The polymerization initiator is preferably used before curing the bonding material (X) or before forming it into a sheet or the like.
Further, in the sheet-shaped bonding material, for example, after producing a composition containing the polymerizable compound and an arbitrary component such as the polymerization initiator and the solvent, the surface of the release liner is coated and dried. Can be manufactured by
It is preferable that the drying is carried out at a temperature of preferably 40 ° C. to 120 ° C., more preferably 50 ° C. to 90 ° C. in order to suppress the progress of the curing reaction of the sheet-shaped bonding material. Further, it is preferable because foaming of the sheet surface due to rapid volatilization of the solvent or the like can be suppressed.

The sheet-shaped bonding material may be sandwiched by the release liner until it is used.
Examples of the release liner include paper such as kraft paper, glassin paper, and high-quality paper; resin films such as polyethylene, polypropylene (OPP, CPP), and polyethylene terephthalate; laminated paper obtained by laminating the paper and the resin film, and the paper. It is possible to use a product which has been sealed with clay or polypropylene alcohol, and which has been subjected to a peeling treatment such as a silicone resin on one side or both sides.

Since the laminate of the present invention is relatively flexible before curing, it has excellent step-following ability with respect to the adherend, and after curing, it becomes extremely hard, so that the adherend can be sufficiently bonded. It can be used as a material for firmly joining various members used in an image display device.

Examples of the image display device include mobile terminals (PDAs) such as personal computers, mobile phones, smartphones and tablet PCs, game machines, televisions (TVs), car navigation systems, touch panels, pen tablets and the like, LCDs, PDPs or ELs, organic ELs, etc. Examples of components of a flat image display device using an image display panel equipped with a micro LED, a quantum dot (QD), and the like can be mentioned. Examples of the components include an image display panel, a circuit board, a rear cover, a bezel, a frame, and a chassis.

Examples and comparative examples will be specifically described below.

<Adjustment of acrylic copolymer (1)>
Preparation of Acrylic Copolymer In a reaction vessel equipped with a stirrer, a cold current cooler, a thermometer, a dropping funnel and a nitrogen gas inlet, 25 parts by mass of n-butyl acrylate, 80 parts by mass of 2-methoxyethyl acrylate, and 2-hydroxyethyl 1 part by mass of acrylate and 0.2 part of 2,2'-azobisisobutylnitrile as a polymerization initiator are dissolved in 100 parts by mass of ethyl acetate, polymerized at 80 ° C. for 8 hours after substitution with nitrogen, and the solid content is 50. An acrylic copolymer (1) having a mass% and a weight average molecular weight of 750,000 was obtained. The glass transition temperature was −25 ° C.

<Preparation of polyurethane (1)>
50 parts by mass of an aliphatic polycarbonate polyol having a number average molecular weight of 2000, and 1,6-hexanediol and adipic acid obtained by reacting 1,5-pentanediol, 1,6-hexanediol and dialkyl carbonate are placed in a reaction vessel. 30 parts by mass of a polyester polyol having a number average molecular weight of 4500 obtained by the reaction was mixed and heated to 100 ° C. under reduced pressure conditions to dehydrate the mixture until the water content reached 0.05% by mass.

Next, the mixture of the aliphatic polycarbonate polyol and the polyester polyol was cooled to 70 ° C., mixed with 14.5 parts by mass of dicyclohexylmethane-4,4'-diisocyanate, and then heated to 100 ° C. It was allowed to react for 3 hours. Then, polyurethane (1) was obtained by preparing methyl ethyl ketone so that the solid content was 50% by mass. The glass transition temperature was −28 ° C.

<Adjustment of joining material (A-1)>
EX-321L (manufactured by Nagase Chemtech Co., Ltd., trimethylolpropane polyglycidyl ether type epoxy resin) 50 parts by mass, the acrylic copolymer (1) 100 parts by mass, CPI-100P (manufactured by San Apro Co., Ltd., sulfonium salt type) 2 mass parts 0.20 parts by mass of Burnock DN980 (hexamethylene diisocyanate type isocyanate cross-linking agent manufactured by DIC Co., Ltd.) was mixed to obtain a bonding resin coating material (a-1).

Next, the adhesive resin coating material (a-1) was applied to the surface of a release liner (one side of a polyethylene terephthalate film having a thickness of 75 μm was peeled off with a silicone compound) using a rod-shaped metal applicator. , The coating was applied so that the thickness after drying was 100 μm.

Further, the coated product was put into a dryer at 85 ° C. for 5 minutes to be dried, and one side of the dried coated product was peeled off with a release liner (one side of a polyethylene terephthalate film having a thickness of 38 μm was peeled off with a silicone compound. Things) were pasted together. Then, it was aged at 40 ° C. for 72 hours to obtain a sheet-shaped bonding material (A-1) having a thickness of 100 μm.

Since the bonding material (A-1) has a photopolymerization initiator and an epoxy group as a reaction site, the curing reaction of the epoxy group is activated by irradiating with light. It is possible to do.

The storage elastic modulus of the bonding material (A-1) at 23 ° C. was 1.7 × 10 ⁴ Pa, and the storage elastic modulus at 70 ° C. was 2.9 × 10 ³ Pa.

The storage elastic modulus of the bonding material (A-1) at 23 ° C. and 70 ° C. was measured by using a dynamic viscoelasticity tester (manufactured by Leometrics, trade name: Ares 2KSTD). The test piece was sandwiched between the parallel disks, and the temperature was measured in the range of a temperature rising rate of 3 ° C./min, a measurement frequency of 1.0 Hz, and a measurement temperature range of 0 to 200 ° C., and calculated respectively. As the test piece used in the above measurement, after removing the release liner on one surface of the bonding material (A-1), the test pieces are laminated to a thickness of 1 mm and cut into a circle having a diameter of 8 mm. I used the one that I did.

<Adjustment of joining material (A-2)>
Except for using CEL2021P (Daicel, alicyclic epoxy resin) instead of 50 parts by mass of EX-321L (Trimethylolpropane polyglycidyl ether type epoxy resin, Nagase Chemtech), the bonding material (Alicyclic epoxy resin) A bondable resin paint (a-2) and a bonding material (A-2) were obtained in the same manner as in the adjustment of A-1).

Since the bonding material (A-2) has a photopolymerization initiator and an epoxy group as a reaction site, the curing reaction of the epoxy group is activated by irradiating with light. It is possible to do.

The storage elastic modulus of the bonding material (A-2) at 23 ° C. was 9.3 × 10 ³ Pa, and the storage elastic modulus at 70 ° C. was 1.0 × 10 ³ Pa.

<Adjustment of joining material (A-3)>
A bonding resin coating material (A-1) is prepared in the same manner as the bonding material (A-1), except that 2.0 parts by mass of DICY-7 (manufactured by Mitsubishi Chemical Corporation, dicyandiamide) is used instead of CPI-100P. a-3) and a bonding material (A-3) were obtained.

Since the bonding material (A-3) has a thermal polymerization initiator and an epoxy group as a reaction site, the curing reaction of the epoxy group is activated by heating. Is possible.

The storage elastic modulus of the bonding material (A-3) at 23 ° C. was 9.6 × 10 ³ Pa, and the storage elastic modulus at 70 ° C. was 1.0 × 10 ³ Pa.

As the adherend used in this example and the comparative example, an aluminum plate having a smooth surface and a thickness of 0.05 mm was cut into a width of 15 mm and a length of 150 mm, and this was designated as an adherend (I). Further, an epoxy glass plate (manufactured by Shin-Kobe Electric Machinery Co., Ltd./KEL-GEF) having a smooth surface and a thickness of 1.0 mm was cut into a width of 15 mm and a length of 150 mm, and this was used as an adherend (II). The adherend (I) and the adherend (II) are light-impermeable materials.

<Adjustment of joining material (A-4)>
100 parts by mass of polyurethane (1) was used instead of the acrylic copolymer (1), and the amount of CEL-2021P (alicyclic epoxy resin manufactured by Daicel) was changed from 50 parts by mass to 21 parts by mass. The amount of CPI-100P (manufactured by San Appro, sulfonium salt type, solid content concentration 50%) was changed from 2 parts by mass to 2.9 parts by mass, and Bernock DN980 (manufactured by DIC Co., Ltd., hexamethylene diisocyanate type isocyanate cross-linking) was changed. The adhesive resin coating material (a-4) and the bonding material (a-4) are prepared in the same manner as the adjustment of the bonding material (A-1) except that the amount of the agent) used is changed from 0.20 parts by mass to 0 parts by mass. A-4) was obtained.

Since the bonding material (A-4) has a photopolymerization initiator and an epoxy group as a reaction site, the curing reaction of the epoxy group is activated by irradiating with light. It is possible to do.

The storage elastic modulus of the bonding material (A-4) at 25 ° C. was 4.9 × 10 ⁴ Pa, and the storage elastic modulus at 70 ° C. was 1.2 × 10 ¹ Pa.

(Example 1)
A test sample was obtained by cutting the bonding material (A-1) into a size of 10 mm in width × 10 mm in length. One of the release liners of the test sample was removed and attached to the adherend (I) at 23 ° C.
It was allowed to stand in an environment of 70 ° C. for 30 minutes with a load of 1 kg from the top of the patch.
After the standing, the load of 1 kg was removed from the patch and left in an environment of 23 ° C. for 30 minutes. Then, the release liner was removed from the other surface of the test sample, and the exposed surface layer of the bonding material was irradiated with ultraviolet rays at 250 mJ / cm ² using an electrodeless lamp (fusion lamp H bulb).
After the irradiation, the mixture was left at 23 ° C. for 2 minutes, the adherend (II) was attached to the surface of the bonded material layer after the irradiation, and the mixture was applied at 0.5 MPa using a heat press device heated to 40 ° C. Press-pressed for 10 seconds under pressure.
The laminate after press crimping was left to heat at 70 ° C. for 1 hour and left to cool in an environment of 23 ° C. for 30 minutes, which was used as an evaluation sample (X-1).

The time required for preparing the evaluation sample (X-1) was 2 hours 32 minutes 10 seconds. In addition, the time required for curing the evaluation sample (X-1) was 1 hour.

In the evaluation sample (X-1), the ends of the adherend (I) and the adherend (II) are chucked, respectively, and a tensile tester is used in the 180-degree direction at a tensile speed of 10 mm / min. The shear adhesive force of the evaluation sample (X-1) was determined by a tensile test. The shear adhesive force of the evaluation sample (X-1) at this time was 920 Pa.

Further, the storage elastic modulus of the cured product (B-1) of the sheet-shaped bonding material (A-1) obtained by the same curing method as the evaluation sample (X-1) at 25 ° C. is 5.7 × 10. It was ⁵ Pa.

Further, the storage elastic modulus of the cured product (B-1) of the sheet-shaped bonding material (A-1) at 25 ° C. was determined by using a dynamic viscoelasticity measuring device (RSA III manufactured by TA Instruments). The temperature rise rate was 3 ° C./min, the measurement frequency was 1.0 Hz, and the measurement temperature range was 0 to 200 ° C., and the storage elastic moduli (G') at 25 ° C. and 100 ° C. were calculated, respectively.

(Example 2)
A test sample was obtained by cutting the bonding material (A-1) into a size of 10 mm in width × 10 mm in length. One of the release liners of the test sample was removed and attached to the adherend (I) at 23 ° C.
The patch was left in an environment of 23 ° C. for 30 minutes. Then, the release liner was removed from the other surface of the test sample, and the exposed surface layer of the bonding material was irradiated with ultraviolet rays at 250 mJ / cm ² using an electrodeless lamp (fusion lamp H bulb).
After the irradiation, the mixture was left at 23 ° C. for 2 minutes, the adherend (II) was attached to the surface of the bonded material layer after the irradiation, and the mixture was applied at 0.5 MPa using a heat press device heated to 40 ° C. Press-pressed for 10 seconds under pressure.
The laminate after press crimping was left to heat at 70 ° C. for 1 hour and left to cool in an environment of 23 ° C. for 30 minutes, which was used as an evaluation sample (X-2).

The time required for preparing the evaluation sample (X-2) was 2 hours, 2 minutes and 10 seconds. The time required for curing the evaluation sample (X-2) was 1 hour.

The shear adhesive force of the evaluation sample (X-2) was determined by the same method as in Example 1. The shear adhesive force of the evaluation sample (X-2) at this time was 880 Pa.

Further, the storage elastic modulus of the cured product (B-2) of the sheet-shaped bonding material (A-1) obtained by the same curing method as the evaluation sample (X-2) at 25 ° C. is 4.9 × 10. It was ⁵ Pa.

(Example 3)
An evaluation sample (X-3) was prepared in the same manner as in Example 1 except that the bonding material (A-2) was used.
The time required for preparing the evaluation sample (X-3) was 2 hours 32 minutes 10 seconds. Further, the time required for curing the evaluation sample (X-3) was 1 hour.
The shear adhesive force of the evaluation sample (X-3) was determined by the same method as in Example 1. The shear adhesive force of the evaluation sample (X-3) at this time was 1100 Pa.

Further, the storage elastic modulus of the cured product (B-3) of the sheet-shaped bonding material (A-1) obtained by the same curing method as the evaluation sample (X-3) at 25 ° C. is 6.3 × 10. It was ⁶ Pa.

(Example 4)
Using the bonding material (A-4), except for changing the amount of ultraviolet irradiation using an electrodeless lamp (Fusion lamp H bulb) from 250 mJ / cm ² to 500 mJ / cm ^2, as in Example 1 An evaluation sample (X-4) was prepared by the method.

The time required for preparing the evaluation sample (X-4) was 2 hours 32 minutes 10 seconds. Further, the time required for curing the evaluation sample (X-4) was 1 hour.

The shear adhesive force of the evaluation sample (X-4) was determined by the same method as in Example 1. The shear adhesive force of the evaluation sample (X-4) at this time was 3700 Pa.

Further, the storage elastic modulus of the cured product (B-4) of the sheet-shaped bonding material (A-1) obtained by the same curing method as the evaluation sample (X-4) at 25 ° C. is 5.8 × 10. It was ⁸ Pa.

(Example 5)
A test sample was obtained by cutting the bonding material (A-4) into a size of 10 mm in width × 10 mm in length. One of the release liners of the test sample was removed and attached to the adherend (I) at 23 ° C.
Then, the patch was left in an environment of 23 ° C. for 30 minutes. Then, the release liner was removed from the other surface of the test sample, and the exposed surface layer of the bonding material was irradiated with ultraviolet rays at 500 mJ / cm ² using an electrodeless lamp (fusion lamp H bulb).
After the irradiation, the mixture was left at 23 ° C. for 2 minutes, the adherend (II) was attached to the surface of the bonded material layer after the irradiation, and the mixture was applied at 0.5 MPa using a heat press device heated to 40 ° C. Press-pressed for 10 seconds under pressure.
Then, it was allowed to stand in an environment of 70 ° C. for 5 minutes with a load of 1 kg from the top of the patch.
After the standing, the 1 kg load was removed from the patch, the mixture was heated and left at 70 ° C. for 55 minutes, and left at 23 ° C. for 30 minutes to be cooled, which was used as an evaluation sample (X-5).

The time required for preparing the evaluation sample (X-5) was 2 hours, 2 minutes and 10 seconds. Further, the time required for curing the evaluation sample (X-5) was 1 hour.

The shear adhesive force of the evaluation sample (X-4) was determined by the same method as in Example 1. The shear adhesive force of the evaluation sample (X-4) at this time was 3500 Pa.

Further, the storage elastic modulus of the cured product (B-4) of the sheet-shaped bonding material (A-1) obtained by the same curing method as the evaluation sample (X-4) at 25 ° C. is 4.3 × 10. It was ⁸ Pa.

(Comparative Example 1)
A test sample was obtained by cutting the bonding material (A-1) into a size of 10 mm in width × 10 mm in length. One of the release liners of the test sample was removed, and the adherend (I) was attached.
It was allowed to stand for 30 minutes in an environment of 70 ° C. with a load of 1 kg on the patch.
After the standing, the load of 1 kg was removed from the patch and left in an environment of 23 ° C. for 30 minutes. Then, the release liner was removed from the other surface of the test sample, the adherend (II) was attached to the surface of the bonded material layer after the irradiation, and the heat press device heated to 40 ° C. was used. Press-pressed for 10 seconds while pressurized at 0.5 MPa.
After the crimping, ultraviolet rays were irradiated at 250 mJ / cm ² from the attached adherend (I) side using an electrodeless lamp (fusion lamp H bulb).
The laminated body after the irradiation was left to be heated at 70 ° C. for 1 hour and then left to cool in an environment of 23 ° C. for 30 minutes, which was used as an evaluation sample (X'-1).

The time required for preparing the evaluation sample (X'-1) was 2 hours 30 minutes 10 seconds. The time required for curing the evaluation sample (X'-1) was 1 hour.

The shear adhesive force of the evaluation sample (X'-1) was determined by the same method as in Example 1. At this time, the shear adhesive force of the evaluation sample (X'-1) was 40 Pa.

Further, the storage elastic modulus of the cured product (B'-1) of the sheet-shaped bonding material (A-1) obtained by the same curing method as the evaluation sample (X'-1) at 25 ° C. is 1.7. It was × 10 ⁴ Pa.

(Comparative Example 2)
A test sample was obtained by cutting the bonding material (A-1) into a size of 10 mm in width × 10 mm in length. One of the release liners of the test sample was removed, and the adherend (I) was attached.
The patch was left in an environment of 23 ° C. for 30 minutes. Then, the release liner was removed from the other surface of the test sample, the adherend (II) was attached to the surface of the bonded material layer after the irradiation, and the heat press device heated to 40 ° C. was used. Press-pressed for 10 seconds while pressurized at 0.5 MPa.
After the crimping, ultraviolet rays were irradiated at 250 mJ / cm ² from the affixed adherend (II) side using an electrodeless lamp (fusion lamp H bulb).
The laminated body after the irradiation was left to heat at 70 ° C. for 1 hour, and left to cool in an environment of 23 ° C. for 30 minutes, which was used as an evaluation sample (X'-2).

The time required for preparing the evaluation sample (X'-2) was 2 hours and 10 seconds. The time required for curing the evaluation sample (X'-2) was 1 hour.

The shear adhesive force of the evaluation sample (X'-2) was determined by the same method as in Example 1. The shear adhesive force of the evaluation sample (X'-2) at this time was 38 Pa.

Further, the storage elastic modulus of the cured product (B'-2) of the sheet-shaped bonding material (A-1) obtained by the same curing method as the evaluation sample (X'-2) at 25 ° C. is 1.7. It was × 10 ⁴ Pa.

(Comparative Example 3)
A test sample was obtained by cutting the bonding material (A-3) into a size of 10 mm in width × 10 mm in length. One of the release liners of the test sample was removed, and the adherend (I) was attached.
It was allowed to stand in an environment of 70 ° C. for 30 minutes with a load of 1 kg from the top of the patch.
After the standing, the load of 1 kg was removed from the patch and left in an environment of 23 ° C. for 30 minutes. Then, the release liner was removed from the other surface of the test sample, the adherend (II) was attached to the surface of the bonded material layer after the irradiation, and the heat press device heated to 40 ° C. was used. Press-pressed for 10 seconds while pressurized at 0.5 MPa.
The pressurized laminate was left to be heated at 180 ° C. for 1 hour and left to cool in an environment of 23 ° C. for 30 minutes, which was used as an evaluation sample (X'-3).

The total time required to prepare the evaluation sample (X'-3) was 2 hours 30 minutes 10 seconds. The time required for curing the evaluation sample (X'-3) was 1 hour. When the evaluation sample (X'-3) was visually confirmed, the adherend (II) deteriorated and turned yellow.

The shear adhesive force of the evaluation sample (X'-3) was determined by the same method as in Example 1. The shear adhesive force of the evaluation sample (X'-3) at this time was 203 Pa.

Further, the storage elastic modulus of the cured product (B'-3) of the sheet-shaped bonding material (A-1) obtained by the same curing method as the evaluation sample (X'-3) at 25 ° C. is 7.5. It was × 10 ⁶ Pa.

(Comparative Example 4)
A test sample was obtained by cutting the bonding material (A-3) into a size of 10 mm in width × 10 mm in length. One of the release liners of the test sample was removed, and the adherend (I) was attached.
It was allowed to stand in an environment of 70 ° C. for 30 minutes with a load of 1 kg from the top of the patch.
After the standing, the load of 1 kg was removed from the patch and left in an environment of 23 ° C. for 30 minutes. Then, the release liner was removed from the other surface of the test sample, the adherend (II) was attached to the surface of the bonded material layer after the irradiation, and the heat press device heated to 40 ° C. was used. Press-pressed for 10 seconds while pressurized at 0.5 MPa.
The pressurized laminate was left to be heated at 70 ° C. for 3 hours and left to cool in an environment of 23 ° C. for 30 minutes, which was used as an evaluation sample (X'-4).

The time required for preparing the evaluation sample (X'-4) was 4 hours 30 minutes 10 seconds. The time required for curing the evaluation sample (X'-4) was 3 hours.

The shear adhesive force of the evaluation sample (X'-4) was determined by the same method as in Example 1. The shear adhesive force of the evaluation sample (X'-4) at this time was 115 Pa.

Further, the stored elastic modulus of the cured product (B'-3) of the sheet-shaped bonding material (A-1) obtained by the same curing method as the evaluation sample (X'-3) at 25 ° C. is 6.5. It was × 10 ⁴ Pa.

From the above results, it can be seen that in Examples 1 to 5, a laminated body can be produced in a short time and at a low temperature, and sufficient bonding can be obtained even for an opaque adherend, while Comparative Examples. In 1 and 2, although the laminated body was produced in a short time and at a low temperature, the bonding material was not cured and sufficient bonding could not be obtained. Further, in Comparative Example 3, although the bonding was obtained in a short time, the adherend was deteriorated because the curing required a high temperature. In Comparative Example 4, although the bonding was obtained at a low temperature, it took a lot of time.

Claims (4)

A method for producing a laminate in which an adherend (C1) and an adherend (C2) are contained via a bonding material (X) containing an acrylic copolymer or polyurethane, an epoxy resin, and a photocationic polymerization initiator. The step [01] of attaching the bonding material (X) to the adherend (C2), the step [1] of activating the reaction site of the bonding material (X) by light irradiation, and the bonding material (X). ) Is attached to the adherend (C1) in this order, and the step [3] for curing the bonding material (X) is included, and between the steps [01] and [1], and In at least one of the steps [2] and [3], the step following the step (curing step) [02] is included.
The step [02] includes a step of heating.
Production method storage modulus of the bonding material (X) is 1.0 × ¹⁰ 5 Pa or more at 25 ° C. after the step [3]. The method for manufacturing a laminate according to claim 1, wherein the step [02] is a step of heating to fill a step. The method for producing a laminate according to claim 1, wherein the bonding material (X) contains an acrylic copolymer or polyurethane having a weight average molecular weight of 2000 to 2000000, an epoxy resin, and a photopolymerization initiator . The method for producing a laminate according to any one of claims 1 to 3, which includes a step of following a step (curing step) [02] between the step [01] and the step [1].