KR20200019792A - Photocurable adhesive sheet, adhesive sheet and image display device - Google Patents

Abstract

According to the stepped portion of the bonding surface, it is possible to fill up to the corner, and even if it is irradiated for a long time, the adhesive reliability which does not fall, and the bonding operation can be performed easily is provided. Therefore, it is a photocurable adhesive sheet before photocuring formed from the resin composition containing a (meth) acrylic-type copolymer (A), a crosslinking agent (B), and a photoinitiator (C), and also has following (1) and The adhesive sheet provided with the characteristic of (2) is proposed.
(1) In 0-40 degreeC, shape retention can be performed and self-adhesiveness is shown.
(2) In 70-100 degreeC, a viscosity shows 100-3000 Pa.s.

Description

Photocurable adhesive sheet, adhesive sheet, and image display device {PHOTOCURABLE ADHESIVE SHEET, ADHESIVE SHEET AND IMAGE DISPLAY DEVICE}

The present invention relates to a photocurable pressure sensitive adhesive sheet before photocuring and a pressure sensitive adhesive sheet obtained by photocuring the same. Specifically, the present invention relates to an image display device such as a personal computer, a mobile terminal (PDA), a game machine, a television (TV), a car navigation system, a touch panel, a pen tablet, and the like, and an adhesive sheet that can be suitably used.

In order to improve the visibility of an image display apparatus in recent years, image display panels, such as a liquid crystal display (LCD), a plasma display (PDP), or an electro luminescence display (ELD), and its front side (viewing side) Filling the gap between the protective panel and the touch panel member disposed on the sheet with an adhesive sheet, a liquid adhesive, or the like, and suppressing reflection at the air layer interface of the incident light or the emitted light from the display image is performed. .

As a method of filling the space | gap between such structural members for image display apparatuses using an adhesive, the method of making it irradiate and harden | cure ultraviolet-ray after filling the space | gap with the liquid adhesive resin composition containing an ultraviolet curable resin is known. (Patent Document 1).

Moreover, the method of filling the space | gap between the structural members for image display apparatuses using an adhesive sheet is also known. For example, PTL 2 is a method of manufacturing a laminate for an image display device configuration, which is provided with a configuration in which a structural member for an image display device is laminated on at least one side of an adhesive sheet, and is a pressure sensitive adhesive sheet that is primarily crosslinked by ultraviolet rays. After bonding to the structural member for image display apparatuses, the method of irradiating an adhesive sheet with ultraviolet-ray through a structural member for image display apparatuses and performing a secondary hardening is disclosed.

In addition, Patent Literature 3 discloses a sheet using a hot melt type adhesive composition having a loss tangent at 25 ° C. of less than 1 having a urethane (meth) acrylate having a weight average molecular weight of 20,000 to 100,000 as a main component.

Moreover, in patent document 4, the adhesive layer suitable for bonding of the (meth) acrylic-type polymer obtained by copolymerizing the monomer containing a (meth) acrylic-type monomer which has a crosslinkable functional group, and a specific macromer, and a crosslinking agent is included Is disclosed.

International Publication No. 2010/027041 International Publication 2012/032995 International Publication No. 2010/038366 Japanese Laid-Open Patent Publication No. 2013-18227 Japanese Patent Laid-Open No. 2012-184423

In the field of an image display device mainly on a mobile phone or a mobile terminal, in addition to thinning and high definition, design diversification is progressing, and new problems have arisen accordingly. For example, it is common to print a black concealment in a frame shape on the periphery of the surface protection panel. Therefore, the adhesive sheet for pasting the structural member provided with such a printing part requires the printing step track | trackability which can be filled to a corner following a printing step | step.

Moreover, image display apparatuses, such as a touch panel, have been used extensively, and accordingly, the adhesive sheet which is used for the laminated body for image display apparatus structures does not reduce performance even if it is exposed to light, such as illumination or sunlight for a long time. Reliability is required.

The 1st objective of this invention is an adhesive sheet which can follow the step part of a joining surface in the state before photocuring, and can fill it to a corner, and also the adhesive reliability which does not fall even if it irradiates for a long time in the state after photocuring, An object of the present invention is to provide a new adhesive sheet that can easily perform a lamination work.

According to the second object of the present invention, even when a light impermeable portion such as a printing portion and an image display device structural member having the light transmissive portion are pasted together, the followability to the step portion and the surface flatness can be obtained. Even in the permeation part, distortion and deformation are not generated, and in addition, the adherends can be firmly bonded to each other with high cohesive force, and furthermore, the exposed adhesive surface can be made non-sticky even under severe environments such as high temperature and high humidity. It is in providing the new adhesive sheet which exists.

The third object of the present invention is a pressure-sensitive adhesive sheet capable of photocrosslinking, which has adhesiveness even before photocrosslinking, and in the case of pasting, the pressure-sensitive adhesive material does not flow excessively and the pressure-sensitive adhesive resin composition is not pushed out or crushed. It is providing the adhesive sheet which can acquire sufficient hardness.

This invention is an adhesive sheet before photocuring formed from the resin composition containing the said (meth) acrylic-type copolymer (A), a crosslinking agent (B), and a photoinitiator (C), in order to achieve the 1st objective, Photocurability Furthermore, the adhesive sheet characterized by having the following (1) and (2) characteristics is proposed.

(1) In 0-40 degreeC, shape retention can be performed and self-adhesiveness is shown.

(2) In 70-100 degreeC, a viscosity shows 100-3000 Pa.s.

The pressure-sensitive adhesive sheet proposed in order to achieve the first object of the present invention can hold a sheet shape in a room temperature state of 0 to 40 ° C, that is, a normal state, and can exhibit self-adhesion. Therefore, it is easy to handle and the bonding operation | work etc. can be performed efficiently, for example, being easy to carry out the positioning at the time of sticking. Moreover, when it becomes 70-100 degreeC, since a viscosity becomes 100-3000 Pa * s and shows hot melt property, it can harvest the uneven | corrugated parts, such as a printing step, and can fill an adhesive, for example. Moreover, after photocuring, high cohesion force is expressed, for example, it demonstrates the excellent foaming resistance even after long time light irradiation, and even if it irradiates for a long time, adhesive reliability does not fall. Therefore, the photocurable adhesive sheet proposed by the present invention can be suitably used as a constituent member of an image display device such as a personal computer, a mobile terminal (PDA), a game machine, a television (TV), a car navigation system, a touch panel, a pen tablet, and the like. .

MEANS TO SOLVE THE PROBLEM This invention is an adhesive sheet which contains a (meth) acrylic-type copolymer (A) and is photocured, in order to achieve the 2nd objective, The sheet part whose gel fraction is less than 1%, and the sheet whose gel fraction is 40% or more The adhesive sheet which has a part is proposed.

According to the present invention, the pressure-sensitive adhesive sheet proposed in order to achieve the second object has a sheet portion having a gel fraction of less than 1%, which can achieve followability and surface flatness to a step portion, and can alleviate distortion and deformation in the sheet. On the other hand, by the sheet portion having a gel fraction of 40% or more, not only the adhesive surface can be made sticky, but also the adherends can be firmly adhered to each other with high cohesive force.

Therefore, for example, even when sticking the light-transmissive part, such as a printing part, and the structural member for image display apparatuses which have a light-transmitting part in a joining surface, the followability and surface flatness with respect to a printing step part can be acquired as a whole adhesive sheet. In addition, even in the light-transmissive portion, distortion and deformation are not generated, and further, the adherends can be firmly bonded to each other with high cohesive force. In addition, by making the exposed adhesive surface a hard part, the exposed adhesive surface can be prevented from sticking even in a harsh environment such as under high temperature and high humidity.

This invention is resin containing 100 mass parts of (meth) acrylic-type copolymers (A), 0.5-20 mass parts of crosslinking agents (B), and 0.1-5 mass parts of photoinitiators (C), in order to achieve 3rd objective. a pressure-sensitive adhesive sheet comprising the composition, and offer a pressure-sensitive adhesive sheet, characterized in that the ratio (X ₁ / X ₂₎ of the tensile modulus (X ₁₎ and photo-crosslinking the tensile modulus (X ₂₎ after the pre-photo-crosslinking that is more than three.

The pressure-sensitive adhesive sheet proposed in order to achieve the third object of the present invention has a feature that the difference in tensile modulus (X ₁ , X ₂ ) before and after optical crosslinking is remarkably large, and has adhesiveness even before optical crosslinking. In the case, the pressure-sensitive adhesive material is excessively flowed so that the pressure-sensitive adhesive resin composition is not pushed out or crushed, and sufficient hardness can be obtained after photocrosslinking.

1 is a top perspective view showing an example of an adhesive sheet according to the present invention.
2 is a top perspective view showing another example of the pressure sensitive adhesive sheet according to the present invention.
3 is a top perspective view showing still another example of the pressure sensitive adhesive sheet according to the present invention.
FIG. 4: is a figure which shows an example of the adhesive sheet laminated body provided with the adhesive sheet shown to FIG. 3B, (A) is a top perspective view, (B) is sectional drawing.
5 is a top perspective view showing still another example of the pressure sensitive adhesive sheet according to the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, an example of embodiment of this invention is described in detail. However, this invention is not limited to the following embodiment.

[This adhesive sheet 1]

The adhesive sheet (referred to as "this adhesive sheet 1") which concerns on an example of embodiment of this invention is a (meth) acrylic-type copolymer (1-A), a crosslinking agent (1-B), and a photoinitiator (1-C) ) A photosensitive adhesive sheet formed of a resin composition (called "the present pressure sensitive adhesive composition 1") containing photocurable, and having the properties of the following (1) and (2). It is an adhesive sheet characterized by the above-mentioned.

(1) In 0-40 degreeC, shape retention can be performed and self-adhesiveness is shown.

(2) In 70-100 degreeC, a viscosity shows 100-3000 Pa.s.

Here, the "adhesive sheet before photocuring" should just be an adhesive sheet which has photocurability, and does not mean only the adhesive sheet which has not undergone the photocuring process at all. That is, if the adhesive sheet which passed through the photocuring process is further photocurable and has the effect of this invention, for example, it is contained in this invention.

Since this adhesive sheet 1 is equipped with the characteristics of said (1) and (2) in the state before photocuring, it can hold | maintain a sheet shape in 0 to 40 degreeC room temperature state, when it reduces, and a normal state, Moreover, it has self-adhesion property, ie, the property to exhibit adhesive force in the state as it is. Furthermore, it shows the hot-melt property which melts or flows when it heats, exhibits the outstanding cohesion force after photocuring, for example, can exhibit foaming resistance after long-term light irradiation.

<Characteristics at room temperature>

This adhesive sheet 1 has the characteristic that it can hold | maintain a sheet shape in the room temperature state of 0-40 degreeC in the state before (1) photocuring, and also shows self-adhesion property.

Thus, if a sheet shape can be hold | maintained in room temperature state, ie, a normal state, handling is easy and productivity of a joining member is especially excellent. Moreover, in a normal state, when self-adhesion is shown, it is easy to carry out positioning at the time of sticking, for example, and pasting operation is very convenient.

In order to acquire such a characteristic, what is necessary is just to manufacture this adhesive sheet 1 from the adhesive composition (1-I) or (1-II) mentioned later, for example. However, it is not limited to this.

(180 ° peel at 23 ° C and 40% RH)

This adhesive sheet 1 may have the characteristics of the following (6). That is, (6) It is crimped | bonded to soda-lime glass, and it is 180 degree | times with respect to the glass at the time of peeling the adhesive sheet 1 seen from the said soda-lime glass at peel angle of 180 degrees and peeling rate of 60 mm / min at 23 degreeC40% RH. The peel force can be 3 N / cm or more. When the 180 ° peeling force at 23 ° C. is 3 N / cm or more, it is preferable because it has moderate adhesion to the adherend at normal temperature and is excellent in bonding workability.

From these viewpoints, it is preferable that 180 degree peeling force in 23 degreeC and 40% RH of this adhesive sheet 1 is 3 N / cm or more, Especially, it is 20 N / cm or less, Especially, it is 4 N / cm or more or 15 N / cm or less Especially preferred.

In this adhesive sheet 1, in order to adjust 180 degree peeling force in 23 degreeC40% RH, this adhesive sheet 1 is manufactured from the adhesive composition (1-I) or (1-II) which are mentioned later, for example, Furthermore, what is necessary is just to adjust the kind and composition ratio of a crosslinking agent and a photoinitiator, or to adjust the heating and pressurization conditions at the time of bonding, and the light irradiation conditions after the bonding. However, it is not limited to such a method.

<Characteristics when heating 70 to 100 ° C>

This adhesive sheet 1 has the characteristic that when it heats at 70-100 degreeC before (2) photocuring, a viscosity will be 100-3000 Pa * s and will show fluidity.

If the present adhesive sheet 1 has such hot-melt property, it can be filled by heating and softening or fluidizing to harvest uneven portions such as printing steps to fill the pressure-sensitive adhesive, so that it can be filled without foaming or the like. have.

In order to acquire such a characteristic, what is necessary is just to manufacture this adhesive sheet 1 from the adhesive composition (1-I) or (1-II) mentioned later, for example. However, it is not limited to this.

When this adhesive sheet 1 is heated at 70-100 degreeC, a viscosity will be 100-3000 Pa.s, Especially, it is 150 Pa.s or more or 2700 Pa.s or less, Especially, it is preferable to become 200 Pa.s or more or 2500 Pa.s or less. Do.

 (180 ° peel at 80 ° C and 10% RH)

The present adhesive sheet 1 may have the following features (7). That is, (7) the peeling mode at the time of peeling the adhesive sheet 1 seen from the said soda lime glass with the peeling angle 180 degree and the peeling speed 60mm / min at 80 degreeC10% RH by crimping | bonding to soda-lime glass. As fracture | rupture, 180 degree peeling force with respect to glass can be 1 N / cm or less.

The 180 degree peeling force in 80 degreeC is 1 N / cm or less, since high wettability with respect to a to-be-adhered body is obtained, it is preferable.

From these viewpoints, it is preferable that 180 degree peeling force in 80 degreeC10% RH of this adhesive sheet 1 is 1 N / cm or less, Especially it is 0.8 N / cm or less, Especially, it is especially preferable that it is 0.5 N / cm or less. .

In this adhesive sheet 1, in order to adjust 180 degree peeling force in 80 degreeC10% RH, this adhesive sheet 1 is manufactured from the adhesive composition (1-I) or (1-II) mentioned later, for example, Furthermore, what is necessary is just to adjust the kind and composition ratio of a crosslinking agent and a photoinitiator, or to adjust the heating and pressurization conditions at the time of bonding, and the light irradiation conditions after the bonding. However, it is not limited to such a method.

<Characteristics after Photocuring>

This adhesive sheet 1 can be photocured, and (3) it has the characteristic that the viscosity in 70-100 degreeC will be 3000-50000 Pa * s after photocuring.

It is preferable that the viscosity in 70-100 degreeC will be 3000-500000 Pa.s in this adhesive sheet 1 from a viewpoint of obtaining a high cohesion force after photocuring, Especially, 3500 Pa.s or more or 48000 Pa.s or less, The It is more preferable to become 4000 Pa.s or more or 45000 Pa.s or less among them.

(180 ° Peeling Force at 23 ° C and 40% RH after Photocuring)

This adhesive sheet 1 may have the following (4) features after photocuring. That is, (4) The adhesive sheet after photocuring which was crimped onto soda lime glass and irradiated with light and cured at 23 ° C and 40% RH was adhered from the soda lime glass at a peel angle of 180 ° and a peel rate of 60 mm / min. The 180 degree peeling force with respect to the glass at the time of peeling a sheet can be 3 N / cm or more.

Since the to-be-adhered body can be adhere | attached firmly if the 180 degree peeling force in 23 degreeC after photocuring is 3 N / cm or more, it is preferable.

From these viewpoints, it is preferable that 180 degree peeling force in 23 degreeC after photocuring of this adhesive sheet 1 is 3 N / cm or more, Especially it is 4 N / cm or more, Especially, it is especially preferable that it is 5 N / cm or more or 30 N / cm or less. Do.

(180 ° Peeling Force at 80 ° C and 10% RH after Photocuring)

This adhesive sheet 1 may have the following (5) features after photocuring. That is, (5) The adhesive sheet after photocuring which was crimped onto soda lime glass and irradiated with light to cure was cured from the soda lime glass at a peel angle of 180 ° and a peel rate of 60 mm / min at 80 ° C.10% RH. The 180 degree peeling force with respect to the glass at the time of peeling a sheet can be 3 N / cm or more.

It is preferable from the point which is excellent in foaming resistance in a high temperature environment if 180 degree peeling force in 80 degreeC after photocuring is 3 N / cm or more.

From these viewpoints, it is preferable that 180 degree peeling force in 80 degreeC after the photocuring of this adhesive sheet 1 is 3 N / cm or more, Especially it is 4 N / cm or more, Especially, it is especially preferable that it is 5 N / cm or more or 20 N / cm or less. Do.

In this adhesive sheet 1, in order to adjust 180 degree peeling force in 23 degreeC or 80 degreeC after photocuring, the adhesive sheet 1 seen from the adhesive composition (1-I) or (1-II) mentioned later, for example What is necessary is just to manufacture, and also to adjust the kind and composition ratio of a crosslinking agent and a photoinitiator, or to adjust the heating and pressurization conditions at the time of bonding, and the light irradiation conditions after the bonding. However, it is not limited to such a method.

<Out gas generation amount>

It is preferable that the amount of outgassing after light-irradiating this adhesive sheet 1 after photocuring with the xenon arc lamp type light resistance tester of JISK7350-2 (ISO4892-2) for 24 hours is 40000 ppm or more in conversion of hexadecane.

If outgas generation amount is 40000 ppm or more in conversion of hexadecane, since the tackiness of an adhesive sheet and the wettability with respect to a to-be-adhered body improve, it is preferable.

Therefore, from this viewpoint, it is preferable that the said outgas generation amount in this adhesive sheet 1 is 40000 ppm or more in conversion of hexadecane, Especially, it is preferable that it is 45000 ppm or more, especially especially 50000 ppm or more.

In addition, what is necessary is just to manufacture this adhesive sheet 1 from the adhesive composition (1-I) or (1-II) mentioned later, in order to make the outgas generation amount into the said range in this adhesive sheet 1, for example. However, it is not limited to this.

<Expansion Reliability>

It is preferable that this adhesive sheet 1 after photocuring shows the foaming resistance which the diameter of a bubble becomes 5 mm or less in the next foaming resistance test.

Foam resistance test: A laminate is produced by sandwiching an adhesive sheet between two glass plates having a diagonal length of 5 inches or more and a thickness of 1 mm or less, and according to JIS K7350-2 (ISO4892-2), a xenon arc lamp When irradiated with a light resistance tester for 24 hours, the diameter of the bubble which generate | occur | produced in the adhesive sheet is measured.

Since this adhesive sheet 1 has the characteristic that the viscosity in 70-100 degreeC will be 3000-50000 Pa * s after photocuring, it can show such foaming resistance after photocuring. Therefore, since the reliability which does not fall even if it irradiates for a long time light is exhibited, the adhesive reliability which does not deteriorate even if it is exposed to light, such as illumination and sunlight for a long time, can be obtained, for example for various image display apparatuses.

In order to acquire such a characteristic, what is necessary is just to manufacture this adhesive sheet 1 from the adhesive composition (1-I) or (1-II) mentioned later, for example. However, it is not limited to this.

<This adhesive composition 1>

As a suitable example of this adhesive composition 1 used for preparation of this adhesive sheet 1, The acrylic copolymer (1-A1) which consists of a graft copolymer provided with a macromonomer as a branch component, a crosslinking agent (1-B1), and a photoinitiator The adhesive composition (1-I) containing (1-C1) is mentioned.

Moreover, as another example of this adhesive composition 1, monomer a1 whose glass transition temperature (Tg) is less than 0 degreeC, monomer a2 whose glass transition temperature (Tg) is 0 degreeC or more and less than 80 degreeC, and glass transition temperature (Tg) are 80 (Meth) acrylic copolymer (1) obtained by copolymerizing monomer a3 having a degree of C or higher at a molar ratio of a1: a2: a3 = 10 to 40:90 to 35: 0 to 25, and having a weight average molecular weight of 50000 to 400000 (1 And pressure-sensitive adhesive composition (1-II) containing -A2), a crosslinking agent (1-B2), and a photopolymerization initiator (1-C2).

However, the adhesive composition for forming this adhesive sheet 1 is not limited to adhesive composition (1-I) or (1-II).

In addition, a number average molecular weight and a weight average molecular weight use gel permeation chromatography (GPC), and the conversion value using polystyrene as a reference | standard substance is employ | adopted.

When the pressure-sensitive adhesive sheet 1 is produced from the pressure-sensitive adhesive composition (1-I) or (1-II) adjusted by a known method, self-adhesion can be exhibited while maintaining the sheet shape at room temperature, and when heated in an uncrosslinked state, It has melt-flowing hot-melt property, can further be photocured, and exhibits excellent cohesive force after photocuring.

<Adhesive Composition (1-I)>

As an adhesive composition (1-I), it contains the acryl-type copolymer (1-A1) which consists of a graft copolymer provided with a macromonomer as a branch component, a crosslinking agent (1-B1), and a photoinitiator (1-C1). A pressure-sensitive adhesive composition can be mentioned.

 (Acrylic Copolymer (1-A1))

The acrylic copolymer (1-A1) as the base polymer may be a graft copolymer having a macromonomer as a branch component.

(Stem component)

It is preferable that the stem component of the said acrylic copolymer (1-A1) is comprised from the copolymer component containing the repeating unit derived from (meth) acrylic acid ester.

It is preferable that the glass transition temperature of the copolymer which comprises the stem component of the said acrylic copolymer (1-A1) is -70-0 degreeC.

At this time, the glass transition temperature of the copolymer component which comprises a stem component refers to the glass transition temperature of the polymer obtained by copolymerizing only the monomer component which comprises the stem component of an acryl-type copolymer (1-A1). Specifically, the value calculated by Fox's calculation formula from the glass transition temperature and composition ratio of the polymer obtained from the homopolymer of each component of the said copolymer is meant.

In addition, the calculation formula of Fox is a calculated value calculated | required by the following formula | equation, and can be calculated | required using the value described in a polymer handbook (Polymer HandBook, J. Brandrup, Interscience, 1989).

1 / (273 + Tg) = Σ (Wi / (273 + Tgi))

[Wherein, Wi represents the weight fraction of the monomer i, Tgi represents the Tg (° C.) of the homopolymer of the monomer i.]

The glass transition temperature of the copolymer component which comprises the stem component of the said acrylic copolymer (1-A1) is the softness | flexibility of the adhesive composition (1-I) in a room temperature state, or the adhesive composition (1-I) with respect to a to-be-adhered body. In order to obtain wettability, ie, adhesiveness, the glass transition temperature is preferably -80 ° C to 0 ° C, in order for the pressure-sensitive adhesive composition (1-I) to obtain appropriate adhesion (tackiness) at room temperature. It is especially preferable that they are -75 degreeC or more or -5 degrees C or less, especially -70 degrees C or more or -10 degrees C or less.

However, even if the glass transition temperature of the said copolymer component was the same temperature, viscoelasticity can be adjusted by adjusting molecular weight. For example, it can be made softer by making the molecular weight of a copolymer component small.

As a (meth) acrylic acid ester monomer which the stem component of the said acryl-type copolymer (1-A1) contains, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and isopropyl ( Meta) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl ( Meta) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl Acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylic Late, lau Reel (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, 2- Phenoxyethyl (meth) acrylate, 3,5,5-trimethylcyclohexaneacrylate, p-cumylphenol EO-modified (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylic Elate, dicyclopentenyloxyethyl (meth) acrylate, benzyl (meth) acrylate, etc. are mentioned. It contains hydroxyl groups, such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and glycerol (meth) acrylate which have a hydrophilic group and an organic functional group, etc. in these (meth) Acrylate, (meth) acrylic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxypropyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2 -(Meth) acryloyloxypropylphthalic acid, 2- (meth) acryloyloxyethyl maleic acid, 2- (meth) acryloyloxypropyl maleic acid, 2- (meth) acryloyloxyethyl succinic acid, 2 Carboxyl group-containing monomers such as (meth) acryloyloxypropylsuccinic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleic acid, monomethyl itaconic acid, and acid anhydride groups such as maleic anhydride and itaconic anhydride Monomer, glycidyl (meth) acrylate, -Amino-group-containing (meth) acrylic acid ester, such as epoxy-group-containing monomers, such as glycidyl ethyl acrylate and 3, 4- epoxybutyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and diethylaminoethyl (meth) acrylate System monomer, (meth) acrylamide, Nt-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, Heterocyclic basic monomers, such as monomer containing amide groups, such as diacetone acrylamide, maleic acid amide, and maleimide, vinylpyrrolidone, vinyl pyridine, and vinyl carbazole, etc. can also be used.

Furthermore, styrene, t-butyl styrene, (alpha) -methylstyrene, vinyltoluene, acrylonitrile, methacrylonitrile, vinyl acetate, a vinyl propionate, alkyl vinyl ether, and hydroxyalkyl which can be copolymerized with the said acryl monomer and methacryl monomer are mentioned. Various vinyl monomers, such as a vinyl ether and an alkyl vinyl monomer, can also be used suitably.

Moreover, it is preferable that the stem component of an acryl-type copolymer (1-A1) contains a hydrophobic (meth) acrylate monomer and a hydrophilic (meth) acrylate monomer as a structural unit.

When the stem component of the acrylic copolymer (1-A1) is composed of only hydrophobic monomers, the tendency to wet heat whitening is recognized. Therefore, it is preferable to introduce a hydrophilic monomer into the stem component to prevent wet heat whitening.

Specifically, as the stem component of the acrylic copolymer (1-A1), a hydrophobic (meth) acrylate monomer, a hydrophilic (meth) acrylate monomer, and a polymerizable functional group at the terminal of the macromonomer are randomly copolymerized. The copolymer component which consists of is mentioned.

Here, as said hydrophobic (meth) acrylate monomer, the alkyl ester which does not have a polar group (except methyl acrylate) is preferable, For example, n-butyl (meth) acrylate and isobutyl (meth) ) Acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylic Latex, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, ste Aryl (meth (2) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate And methyl methacrylate.

Moreover, as a hydrophobic vinyl monomer, vinyl acetate, styrene, t-butyl styrene, (alpha) -methylstyrene, vinyltoluene, an alkyl vinyl monomer, etc. are mentioned, for example.

As said hydrophilic (meth) acrylate monomer, methyl acrylate and ester which has a polar group are preferable, For example, methyl acrylate, (meth) acrylic acid, tetrahydrofurfuryl (meth) acrylate, and hydroxyethyl Hydroxyl-containing (meth) acrylates, such as (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and glycerol (meth) acrylate, (meth) acrylic acid, and 2- (meth) ) Acryloyloxyethylhexahydrophthalic acid, 2- (meth) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxypropylphthalic acid, 2- (Meth) acryloyloxyethyl maleic acid, 2- (meth) acryloyloxypropyl maleic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxypropyl succinic acid, crotonic acid , Fumaric acid, maleic acid, Carboxyl group-containing monomers such as taconic acid, monomethyl maleic acid and monomethyl itaconic acid, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride, glycidyl (meth) acrylate, glycidyl (alpha) -ethyl acrylate, ( Alkoxy polyalkylene glycol (meth) acrylates, such as epoxy group containing monomers, such as 3, 4- epoxy butyl methacrylate, and methoxy polyethylene glycol (meth) acrylate, N, N- dimethyl acrylamide, hydroxyethyl acrylamide Etc. can be mentioned.

(Branch ingredient: macromonomer)

It is preferable that an acryl-type copolymer (1-A1) introduce | transduces a macromonomer as a branch component of a graft copolymer, and contains the repeating unit derived from a macromonomer.

A macromonomer is a high molecular monomer which has a terminally polymerizable functional group and a high molecular weight skeleton component.

It is preferable that the glass transition temperature (Tg) of a macromonomer is higher than the glass transition temperature of the copolymer component which comprises the said acrylic copolymer (1-A1).

Specifically, since the glass transition temperature (Tg) of the macromonomer affects the heat melting temperature (hotmelt temperature) of the pressure-sensitive adhesive composition (1-I), the glass transition temperature (Tg) of the macromonomer is 30 ° C to 120 It is preferable that it is ° C, and particularly preferably 40 ° C or more or 110 ° C or less, and more preferably 50 ° C or more or 100 ° C or less.

If it is such a glass transition temperature (Tg), while being excellent in workability and storage stability by adjusting molecular weight, it can adjust so that it may hot melt in 80 degreeC vicinity.

The glass transition temperature of a macromonomer refers to the glass transition temperature of the said macromonomer itself, and can measure it with a differential scanning calorimeter (DSC) (temperature rising rate: 5 degree-C / min, Tg is measured from the inflection point of a baseline shift).

In addition, in a room temperature state, in order that branch components may mutually attract each other and physically bridge | crosslink as an adhesive composition, it may be maintained, and in addition, in order that said physical crosslinking may be loosened and fluidity may be obtained by heating to moderate temperature, a macromonomer It is also preferable to adjust the molecular weight and content of the resin.

From such a viewpoint, it is preferable to contain a macromonomer in the ratio of 5 mass%-30 mass% in an acryl-type copolymer (1-A1), Especially, 6 mass% or more or 25 mass% or less, 8 mass% is especially It is preferable that it is more than 20 mass%.

Moreover, it is preferable that the number average molecular weights of a macromonomer are 500 or more and less than 8000, and especially, it is preferable that they are 800 or more or less than 7500, especially 1000 or more or less than 7000.

As a macromonomer, what is generally manufactured (for example, the macromonomer made from the same synthetic synthetic company etc.) can be used suitably.

It is preferable that the high molecular weight skeleton component of a macromonomer is comprised from an acryl-type polymer or a vinyl type polymer.

As a high molecular weight skeleton component of the said macromonomer, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate Isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, Hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (meth) acrylate, isononyl ( Meth) acrylate, t-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) Acryl Yate, stearyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, 3,5 , 5-trimethylcyclohexane acrylate, p-cumylphenol EO-modified (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylic Latex, benzyl (meth) acrylate, hydroxyalkyl (meth) acrylate, (meth) acrylic acid, glycidyl (meth) acrylate, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, ( (Meth) acrylate monomers such as meta) acrylonitrile, alkoxyalkyl (meth) acrylate, alkoxypolyalkylene glycol (meth) acrylate, styrene, t-butylstyrene, α-methylstyrene, vinyltoluene, alkyl Vinyl monomer, vinyl acetate, alkyl vinyl Various vinyl monomers, such as an ether and hydroxyalkyl vinyl ether, are mentioned, These can be used individually or in combination of 2 or more types.

As a terminal polymerizable functional group of the said macromonomer, a methacryloyl group, acryloyl group, a vinyl group, etc. are mentioned, for example.

 (Cross-linking system (1-B1))

As a crosslinking agent (1-B1), the crosslinking agent which has two or more crosslinkable groups, such as an epoxy group, an isocyanate group, an oxetane group, a silanol group, and a (meth) acryloyl group, can be selected suitably, for example. Especially, from the point of reactivity and the intensity | strength of the hardened | cured material obtained, (meth) acryl which has polyfunctional (meth) acrylate which has two or more (meth) acryloyl groups, three or more especially, an epoxy group, an isocyanate group, etc. Rate is preferred.

By integrating the constituent members for the image display device and then crosslinking the crosslinking agent (1-B1) in the adhesive, the sheet exhibits high cohesive force under a high temperature environment and is excellent in foaming, instead of losing hot meltability. Reliability can be obtained.

As such (meth) acrylate, 1, 4- butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerin di (meth) acrylate, glycerin glycidyl ether di (meth), for example ) Acrylate, 1,6-hexanedioldi (meth) acrylate, 1,9-nonanedioldi (meth) acrylate, tricyclodecanedimethanoldi (meth) acrylate, bisphenol A polyethoxydi (meth ) Acrylate, bisphenol A polyalkoxydi (meth) acrylate, bisphenol F polyalkoxydi (meth) acrylate, polyalkylene glycoldi (meth) acrylate, trimethylolpropanetrioxyethyl (meth) acrylate, ε -Caprolactone modified tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated pentaery Thritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, propoxylated pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate , Polyethylene glycol di (meth) acrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate , Hydroxypivalic acid neopentyl glycol di (meth) acrylate, di (meth) acrylate of ε-caprolactone adduct of hydroxypivalic acid neopentyl glycol, trimethylol propane tri (meth) acrylate, alkoxylated trimethylol Ultraviolet curing type such as propane tri (meth) acrylate and ditrimethylol propane tetra (meth) acrylate In addition to the polyfunctional monomers, polyfunctional acrylic oligomers such as polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, polyether (meth) acrylate, isocyanate (meth) acrylate, 1,1- (bis (meth) acryloyloxymethyl) ethyl isocyanate, 2- (2- (meth) acryloyloxyethyloxy) ethyl isocyanate, glycidyl (meth) acrylate, hydroxyethyl (meth ) Acrylate glycidyl ether, hydroxypropyl (meth) acrylate glycidyl ether, hydroxybutyl (meth) acrylate glycidyl ether, and the like.

Among the above-mentioned, the polyfunctional monomer or oligomer containing polar functional groups, such as a hydroxyl group, is preferable from a viewpoint of improving the adhesiveness to a to-be-adhered body, and the effect of suppressing wet heat whitening.

Especially, it is preferable to use the polyfunctional (meth) acrylic acid ester which has a hydroxyl group or a carboxyl group.

Therefore, from the viewpoint of preventing wet heat whitening, it is preferable to contain a hydrophobic acrylate monomer and a hydrophilic acrylate monomer as the stem component of the acrylic copolymer (1-A1), that is, the graft copolymer. It is preferable to use the polyfunctional (meth) acrylic acid ester which has a hydroxyl group as a crosslinking agent (1-B).

The content of the crosslinking agent (1-B1) is not particularly limited. As a reference, it is preferable that it is 0.5-20 mass parts with respect to 100 mass parts of acrylic copolymers (1-A1), especially 1 mass part or more or 15 mass parts or less, and especially the ratio of 2 mass parts or more or 10 mass parts or less. Do.

By containing a crosslinking agent (1-B1) in the said range, the shape stability of this adhesive sheet 1 in an uncrosslinked state, and the foaming reliability in the adhesive material after crosslinking can be made compatible. However, you may exceed this range by balance with another element.

(Photoinitiator (1-C1))

A photoinitiator (1-C1) functions as a reaction start adjuvant in the crosslinking reaction of the above-mentioned crosslinking agent (1-B1).

As a photoinitiator, a well-known thing can be used suitably now. Especially, the photoinitiator sensitive to the ultraviolet-ray of wavelength 380 nm or less is preferable from a viewpoint of the controllability of a crosslinking reaction.

On the other hand, the photoinitiator which responds to the light of longer wavelength than wavelength 380 nm is preferable at the point which the sensitive light easily reaches to the deep part of this adhesive sheet 1. As shown in FIG.

The photopolymerization initiator is largely classified into two by radical generating mechanisms, and a cleavage type photopolymerization initiator capable of generating a radical by cleaving a single bond of the photopolymerization initiator itself, a photoexcited initiator, and hydrogen in the system. Donors are broadly classified as hydrogen drawing photopolymerization initiators that can form an exciplex and transfer hydrogen of a hydrogen donor.

Among these, the cleavage type photopolymerization initiator decomposes when generating radicals by light irradiation to form another compound, and once excited, it does not have a function as a reaction initiator. For this reason, since it does not remain as active species in the adhesive material after completion | finish of crosslinking reaction, since it is unlikely to cause unexpected light deterioration etc. in an adhesive material, it is preferable.

On the other hand, since the hydrogen-drawn photoinitiator does not generate decomposition products such as cleavage photoinitiators during radical generation reaction by active energy ray irradiation such as ultraviolet rays, it is difficult to become a volatile component after completion of the reaction. It is useful in that damage can be reduced.

As said cleavage type photoinitiator, 2, 2- dimethoxy- 1, 2- diphenyl ethanol 1-one, 1-hydroxy cyclohexyl phenyl ketone, 2-hydroxy-2- methyl-1-phenyl -Propan-1-one, 1- (4- (2-hydroxyethoxy) phenyl) -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- [4- {4- (2-hydroxy-2-methyl-propionyl) benzyl} phenyl] -2-methyl-propane-1-one, oligo (2-hydroxy-2-methyl-1- (4- (1- Methylvinyl) phenyl) propanone), methyl phenylglyoxylate, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2-methyl-1- [4- ( Methylthio) phenyl] -2-morpholinopropane-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl]- 1-butanone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, derivatives thereof, and the like.

As said hydrogen draw type photoinitiator, it is benzophenone, 4-methyl- benzophenone, 2,4,6-trimethyl benzophenone, 4-phenylbenzo phenone, 3,3'- dimethyl- 4-methoxy benzophenone, for example. , 4- (meth) acryloyloxybenzophenone, methyl 2-benzoylbenzoate, methyl benzoyl formate, bis (2-phenyl-2-oxoacetic acid) oxybisethylene, 4- (1,3-acryloyl-1 , 4,7,10,13-pentaoxotridecyl) benzophenone, thioxanthone, 2-chlorothioxanthone, 3-methylthioxanthone, 2,4-dimethylthioxanthone, 2-methylanthraquinone, 2-ethyl anthraquinone, 2-tert- butyl anthraquinone, 2-aminoanthraquinone, its derivatives, etc. are mentioned.

However, it is not limited to the above-mentioned substance as a photoinitiator. Any one of the above-mentioned cleavage type photopolymerization initiator and a hydrogen extraction type photopolymerization initiator may be used, or may be used in combination of 2 or more type.

The content of the photopolymerization initiator (1-C1) is not particularly limited. As a reference | standard, 0.1-10 mass parts with respect to 100 mass parts of acrylic copolymers (1-A1), and 0.5 mass part or more or 5 mass parts or less, especially, it contains in a ratio of 1 mass part or more or 3 mass parts or less. It is preferable.

By making content of a photoinitiator (1-C1) into the said range, suitable reaction sensitivity with respect to an active energy ray can be obtained.

(Other ingredients)

An adhesive composition (1-I) may contain the well-known component mix | blended with a normal adhesive composition as a component of that excepting the above. For example, if necessary, various additives such as tackifier resins, antioxidants, light stabilizers, metal deactivators, anti-aging agents, moisture absorbents, polymerization inhibitors, ultraviolet absorbers, rust inhibitors, silane coupling agents, inorganic particles, etc. may be appropriately contained. It is possible to let.

Moreover, you may contain suitably a reaction catalyst (a tertiary amine compound, a quaternary ammonium compound, a lauryl acid tin compound etc.) as needed.

<Adhesive Composition (1-II)>

As adhesive composition (1-II), monomer a1 whose glass transition temperature (Tg) is less than 0 degreeC, monomer a2 whose glass transition temperature (Tg) is 0 degreeC or more and less than 80 degreeC, and glass transition temperature (Tg) are 80 degreeC or more Monomer a3 is copolymerized in the molar ratio of a1: a2: a3 = 10-40: 90-35: 0-25, and contains the (meth) acrylic acid ester copolymer or vinyl copolymer of the weight average molecular weight 50000-400000. The adhesive composition containing the (meth) acrylic-type copolymer (1-A2), a crosslinking agent (1-B2), and a photoinitiator (1-C2) mentioned above is mentioned.

((Meth) acrylic copolymer (1-A2))

It is preferable that the (meth) acrylic-type copolymer (1-A2) as a base polymer is a (meth) acrylic acid ester copolymer or a vinyl copolymer.

From the viewpoint of making the (meth) acrylic acid ester copolymer or the vinyl copolymer compatible shape retaining properties and hot melt properties at room temperature, the weight average molecular weight is preferably 50000 to 500000, and above all, 60000 or more and 450000 or less, the Especially, it is more preferable that it is 70000 or more or 400000 or less.

In the acrylic ester copolymer, appropriately adjusting the physical properties such as glass transition temperature (Tg) and molecular weight by appropriately selecting the kind, composition ratio, and polymerization conditions of the acrylic monomer and methacryl monomer used to adjust this. It is possible.

At this time, as an acryl monomer which comprises an acrylate ester copolymer, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, n-butyl acrylate, ethyl acrylate etc. are mentioned as a main raw material, for example. have.

In addition to these, the (meth) acryl monomer having various functional groups may be copolymerized with the acryl monomer in accordance with the purpose of imparting cohesive force or imparting polarity.

As the (meth) acryl monomer having the functional group, for example, methyl methacrylate, methyl acrylate, hydroxyethyl acrylate, acrylic acid, glycidyl acrylate, N-substituted acrylamide, acrylonitrile, methacryl Nitrile, fluorine-containing alkyl acrylate, organosiloxy group-containing acrylate and the like.

On the other hand, as a vinyl copolymer, the vinyl copolymer formed by superposing | polymerizing also various vinyl monomers, such as vinyl acetate which can be copolymerized with the said acryl monomer and methacryl monomer, and alkyl vinyl ether, hydroxyalkyl vinyl ether, is mentioned suitably.

As a (meth) acrylic-type copolymer (1-A2) of this adhesive sheet 1, monomer a1 whose glass transition temperature (Tg) is less than 0 degreeC, monomer a2 whose glass transition temperature (Tg) is 0 degreeC or more and less than 80 degreeC, and glass It is preferable that monomer a3 whose transition temperature (Tg) is 80 degreeC or more is a (meth) acrylic acid ester copolymer or vinyl copolymer which copolymerizes in the molar ratio of a1: a2: a3 = 10-40: 90-35: 0-25. Do.

At this time, each glass transition temperature (Tg) of monomers a1, a2, and a3 is the meaning of each glass transition temperature (Tg) at the time of producing a polymer from the said monomer (homopolymerization).

It is preferable that the said monomer a1 is the (meth) acrylic acid ester monomer which has an alkyl group structure which has a C4 or more side chain, for example.

At this time, the side chains having 4 or more carbon atoms may be made of straight chains or may be made of branched carbon chains.

More specifically, it is preferable that the said monomer a1 is a (meth) acrylic acid ester monomer which has a C4-C10 linear alkyl group structure, or is a (meth) acrylic acid ester monomer which has a C6-C18 branched alkyl group structure. .

Here, as "(meth) acrylic acid ester monomer which has a C4-C10 linear alkyl group structure", n-butyl acrylate, n-hexyl acrylate, n-octyl acrylate, n-nonyl acrylate, n-decyl acryl The rate etc. are mentioned.

In addition, as "(meth) acrylic acid ester monomer which has a C6-C18 branched alkyl group structure", 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-methylhexyl acrylate, isooctyl acrylate, iso Nonyl acrylate, isodecyl acrylate, isodecyl methacrylate, etc. are mentioned.

The monomer a2 is a (meth) acrylic acid ester monomer having 4 or less carbon atoms, a (meth) acrylic acid ester monomer having a cyclic skeleton in the side chain, a vinyl monomer having 4 or less carbon atoms, or a vinyl monomer having a cyclic skeleton in the side chain. Is preferably.

Especially, it is especially preferable that the said monomer a2 is a vinyl monomer whose carbon number of a side chain is four or less.

Here, as "the C4 or less (meth) acrylic acid ester monomer", methyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n -Butyl methacrylate, t-butyl acrylate, isobutyl acrylate, isobutyl methacrylate, etc. are mentioned.

As "(meth) acrylic acid ester monomer which has a cyclic skeleton in a side chain", isobornyl acrylate, cyclohexyl acrylate, cyclohexyl methacrylate, 1, 4- cyclohexane dimethanol monoacrylate, tetrahydrofurfuryl meta Acrylate, benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, 2-hydroxy-3-phenoxypropyl acrylate, 3,3,5-trimethylcyclohexanol acrylate And cyclic trimethylol propane formal acrylate, 4-ethoxylated cumylphenol acrylate, dicyclopentenyl oxyethyl acrylate, dicyclopentenyl oxyethyl methacrylate, dicyclopentenyl acrylate and the like.

Examples of the "vinyl monomer having 4 or less carbon atoms" include vinyl acetate, vinyl propionate, vinyl butyrate, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, and the like.

Examples of the "vinyl monomer having a cyclic skeleton in the side chain" include styrene, cyclohexyl vinyl ether, norbornyl vinyl ether, norbornenyl vinyl ether, and the like. Especially, the vinyl monomer whose carbon number of a side chain is four or less, or the acrylic ester monomer whose carbon number of a side chain is four or less is especially suitable.

It is preferable that the said monomer a3 is a (meth) acrylic acid ester monomer whose carbon number of a side chain is 1 or less, or the (meth) acrylic acid ester monomer which has a cyclic skeleton in a side chain.

Here, as a "(meth) acrylic acid ester monomer whose carbon number of a side chain is 1 or less", methyl methacrylate, acrylic acid, methacrylic acid, etc. are mentioned.

As "(meth) acrylic acid ester monomer which has a cyclic skeleton in a side chain", isobornyl methacrylate, 3,3,5-trimethylcyclohexyl methacrylate, dicyclopentanyl acrylate, dicyclopentanyl methacrylate, and dish Clofentenyl methacrylate etc. are mentioned.

 (Meth) acrylic copolymer (1-A2) is obtained by copolymerizing monomer a1, monomer a2 and monomer a3 in a molar ratio of a1: a2: a3 = 10 to 40:90 to 35: 0 to 25 ( If the meta) acrylic acid ester copolymer or vinyl copolymer is included, the peak of Tan-delta can be adjusted to 0-20 degreeC, and a sheet-like shape can be hold | maintained in normal state, ie, room temperature state. In addition, the property of adhering to the adherend in a short time with light force (called "tackiness") can be expressed. Moreover, when heated to the temperature which can be hot melted, fluidity | liquidity will express and it can follow to the step part of a joining surface, and can fill to a corner.

Therefore, from such a viewpoint, the molar ratio of monomer a1, monomer a2, and monomer a3 in the (meth) acrylic acid ester copolymer or vinyl copolymer constituting the (meth) acrylic copolymer (1-A2) is a1. : a2: a3 = 10-40: 90-35: 0-25 is preferable, Especially it is 13-40: 87-35: 0-23, Especially, it is 15-40: 85-38: 2-20 desirable.

Moreover, from the same viewpoint as the above, the molar ratio of monomer a1, monomer a2, and monomer a3 in the (meth) acrylic acid ester copolymer or vinyl copolymer which comprises a (meth) acrylic-type copolymer (1-A2) is , a2> a1> a3.

 (Cross-linking system (1-B2))

By crosslinking agent (1-B2) in this adhesive sheet 1, this adhesive sheet 1 expresses high cohesion force in high temperature environment, and can obtain the outstanding foaming reliability.

As such a crosslinking agent (1-B2), the crosslinking agent which has two or more crosslinkable groups, such as an epoxy group, an isocyanate group, an oxetane group, a silanol group, and a (meth) acryloyl group, can be selected suitably, for example. Especially, from the point of reactivity and the intensity | strength of the hardened | cured material obtained, (meth) acryl which has polyfunctional (meth) acrylate which has two or more (meth) acryloyl groups, three or more especially, an epoxy group, an isocyanate group, etc. Rate is preferred.

As such (meth) acrylate, 1, 4- butanediol di (meth) acrylate, glycerin di (meth) acrylate, 1, 6- hexanediol di (meth) acrylate, 1, 9- furnace, for example Nandiol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, bisphenol A polypropoxydi (meth) acrylate, bisphenol F polyethoxydi (Meth) acrylate, ethylene glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, epsilon -caprolactone modified tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate , Pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, propoxylated Taerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyethylene glycol di (meth) acrylate, tris (acryloxyethyl) isocyanurate, Dipentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, hydroxy pivalic acid neopentyl glycol di (meth) acrylate, hydroxy pivalic acid neopentyl Di (meth) acrylate of the ε-caprolactone adduct of glycol, trimethylolpropane tri (meth) acrylate, trimethylolpropanepolyethoxytri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate In addition to the ultraviolet curing polyfunctional monomers, polyester (meth) acrylate, epoxy (meth) acrylate, Polyfunctional acrylic oligomers, such as urethane (meth) acrylate and polyether (meth) acrylate, isocyanate (meth) acrylate, 1,1- (bis (meth) acryloyloxymethyl) ethyl isocyanate, 2- ( 2- (meth) acryloyloxyethyloxy) ethyl isocyanate, glycidyl (meth) acrylate, hydroxyethyl (meth) acrylate glycidyl ether, hydroxypropyl (meth) acrylate glycidyl ether, Hydroxybutyl (meth) acrylate glycidyl ether etc. are mentioned.

Among the above-mentioned, the polyfunctional monomer or oligomer containing a polar functional group is preferable from a viewpoint of improving the adhesiveness with respect to a to-be-adhered body, the heat resistance, and the effect of suppressing wet heat whitening. Especially, it is preferable to use the polyfunctional (meth) acrylic acid ester which has an isocyanuric ring skeleton.

The content of the crosslinking agent (1-B2) is not particularly limited. As a reference, 0.5-20 mass parts with respect to 100 mass parts of (meth) acrylic-type copolymers (1-A2), 1 mass part or more or 15 mass parts or less, especially 2 mass parts or more or 10 mass parts or less ratio Is preferably.

By containing a crosslinking agent (1-B2) in the said range, the shape stability of this adhesive sheet 1 in an uncrosslinked state, and the foaming reliability in the adhesive sheet after crosslinking can be made compatible. However, you may exceed this range by balance with another element.

(Photoinitiator (1-C2))

A photoinitiator (1-C2) functions as a reaction start adjuvant in the crosslinking reaction of the above-mentioned crosslinking agent (1-B2), and the thing of the base material which concerns on the above-mentioned photoinitiator (1-C1) can be used suitably. .

The content of the photopolymerization initiator (1-C2) is not particularly limited. As a reference, 0.1-10 mass parts with respect to 100 mass parts of (meth) acrylic-type copolymers (1-A2), and 0.5 mass part or more or 5 mass parts or less, especially 1 mass part or more or 3 mass parts or less ratio It is preferable to contain as.

By making content of a photoinitiator (1-C2) into the said range, suitable reaction sensitivity with respect to an active energy ray can be obtained.

(Other ingredients)

An adhesive composition (1-II) may contain the well-known component mix | blended with a normal adhesive composition as a component of that excepting the above. For example, if necessary, various additives such as tackifier resins, antioxidants, light stabilizers, metal deactivators, anti-aging agents, moisture absorbents, polymerization inhibitors, ultraviolet absorbers, rust inhibitors, silane coupling agents, inorganic particles, etc. may be appropriately contained. It is possible to let.

Moreover, you may contain suitably a reaction catalyst (a tertiary amine compound, a quaternary ammonium compound, a lauryl acid tin compound etc.) as needed.

<Lamination composition>

This adhesive sheet 1 may be a sheet which consists of a single layer, or may be a multilayer sheet obtained by laminating two or more layers.

When using this adhesive sheet 1 as a multilayer adhesive sheet, what is necessary is just to comprise the adhesion layer (it is called "this adhesion layer 1") formed from this adhesive composition 1, For example, the laminated structure provided with the intermediate | middle layer and outermost layer. In the case of forming the pressure-sensitive adhesive sheet, it is preferable to form the outermost layer of the present pressure-sensitive adhesive composition 1, especially the pressure-sensitive adhesive composition (1-I) and (1-II).

In addition, this adhesive sheet 1 may be equipped with the structure which forms this adhesive layer 1 formed from this adhesive composition 1 on a release film, and is also a to-be-adhered body, for example, the structure for image display apparatuses mentioned later. It may be provided with the structure which forms the said adhesion layer 1 in a member. For example, the adhesive sheet which has a base material with the structure which forms the said adhesion layer 1 in a base material may be sufficient, and the adhesive sheet which does not have a base material may be sufficient as it. Furthermore, the double-sided adhesive sheet which has the adhesion layer 1 seen on both upper and lower sides may be sufficient, and the single-sided adhesive sheet which has this adhesion layer 1 seen only on the upper and lower single side sides may be sufficient.

<Thickness>

It is preferable that the thickness of the largest thickness part is 250 micrometers or less from a viewpoint that the thickness of this adhesive sheet 1 does not prevent thickness reduction of an image display apparatus. In other words, the present pressure-sensitive adhesive sheet 1 may be a sheet having a uniform thickness, or may be a non-uniform sheet having a partly different thickness. In the case of a sheet having a non-uniform thickness, the thickness of the thickest portion is preferably 250 μm or less. .

Moreover, it is preferable that the thickness of a largest part is 5 micrometers or more, 10 micrometers or more are more preferable, and it is still more preferable that it is 15 micrometers or more from a viewpoint that it does not interfere with adhesive force and impact absorbability with an adherend.

<Use>

Although this adhesive sheet 1 can be used also as it is, it can be used also as follows. However, the usage method of this adhesive sheet 1 is not limited.

This adhesive sheet 1 can be provided as an adhesive sheet laminated body provided with the structure which laminates a release film on one side or both surfaces of this adhesive sheet 1, for example.

<Laminated body 1 for this image display apparatus structure>

In addition, the laminated body for image display apparatus structures provided with the structure formed by laminating | stacking between two structural member for image display apparatus via this adhesive sheet 1 is called "the laminated body 1 for this image display apparatus structure." ) And can be provided.

The laminated body 1 for this image display apparatus structure is laminated | stacked, for example, the structural member for image display apparatuses, and the other structural member for image display apparatuses through the said adhesive sheet 1, and the structure for electronic image display apparatuses, for example. It can be produced by light-irradiating the said adhesive sheet 1 through a member, and photocuring the said adhesive sheet.

As an example of the laminated body 1 for this image display apparatus structure, besides the laminated body which consists of a structure of the protection panel / this adhesive sheet 1 / polarizing film, for example, an image display panel / this adhesive sheet 1 / touch panel, an image display panel / This adhesive sheet 1 / protective panel, image display panel / this adhesive sheet 1 / touch panel / this adhesive sheet 1 / protective panel, polarizing film / this adhesive sheet 1 / touch panel, polarizing film / this adhesive sheet 1 / touch panel / Examples of the structure of the pressure-sensitive adhesive sheet 1 / protective panel may be mentioned.

The protective panel and the image display panel may include a touch panel sensor in the protective panel or the image display panel itself.

<This image display device 1>

The image display apparatus (henceforth "this image display apparatus 1") can also be comprised using this laminated sheet for this adhesive sheet 1 or this image display apparatus structure.

An example of the preferable manufacturing method of this image display apparatus 1 is demonstrated.

First, the present adhesive sheet 1 is heated and hot melted, and the structural member for an image display device and another structural member for an image display device are laminated through the present adhesive sheet 1. In this step, since the present adhesive sheet 1 is moderately flexible, the adhesive sheet 1 can sufficiently follow the step while maintaining the storage stability.

Next, light, such as an ultraviolet-ray, is irradiated from the outer side of the structural member for image display apparatuses. Then, a crosslinking reaction advances and can be photocured, and the outstanding peeling resistance and foaming resistance can be implement | achieved.

Examples of the constituent members for the two image display apparatuses include an image display apparatus such as a personal computer, a mobile terminal (PDA), a game machine, a television (TV), a car navigation system, a touch panel, a pen tablet, and the like. The structural member of this is mentioned. More specifically, the laminated body which consists of any one of the group which consists of a touch panel, an image display panel, a surface protection panel, and a polarizing film, or a combination of 2 or more types is mentioned, for example.

[This adhesive sheet 2]

The adhesive sheet (referred to as "this adhesive sheet 2") which concerns on an example of other embodiment of this invention is an adhesive sheet which contains (meth) acrylic-type copolymer (A) as a base polymer, and is partially photocured. It is an adhesive sheet which has a sheet part (referred to as a "soft part") whose gel fraction is less than 1%, and a sheet part (referred to as a "hard part") whose gel fraction is 40% or more in any of the adhesive sheets.

Extraction by a solvent is mentioned as a measuring method of a gel fraction. Specifically, when the polymer constituting the pressure sensitive adhesive sheet is not crosslinked, a solvent (good solvent) in which the polymer is dissolved is selected, and then the pressure sensitive adhesive sheet is extracted using the solvent. As a solvent at the time of extraction, ethyl acetate, acetone, toluene, xylene, lower alcohol, tetrahydrofuran, etc. are mentioned, for example.

What is necessary is just to set the temperature and time at the time of extraction arbitrarily. After performing the extraction operation, the component (swelling component) which is not dissolved in the solvent may be recovered and dried, and then this weight fraction may be measured. As a specific extraction method, a soxhlet extraction, the method as described in the Example mentioned later, etc. are mentioned.

In addition, when a gel fraction is high, you may crush an adhesive sheet suitably and use it for extraction.

For example, in the display screen of a mobile telephone, a structure in which a polarizing film or the like is laminated on a liquid crystal panel display (LCD), and a protective panel made of plastic is laminated on the adhesive or a sheet thereon is employed. It is common for light impervious parts, such as a printing part, to be provided in the peripheral part of the back surface of a panel.

When pasting the protection panel in which such a printing part was attached through the adhesive sheet with the structural member for image display apparatuses, such as a touch panel, the said adhesive sheet can be filled to a corner following a printing step, If the surface of the sheet is not smooth, the adhesive sheet is distorted or deformed when the image display structural members are pasted together, resulting in a decrease in visibility due to display unevenness, so that the adhesive sheet is required to have flexibility. Moreover, there existed the subject that a distortion and a deformation | transformation tend to arise in an adhesive sheet by printing steps or the like.

On the other hand, even in a harsh environment such as under high temperature and high humidity, it is required that the exposed adhesive surface is not sticky. In addition, the high adhesive force which does not produce peeling or foaming is also calculated | required by the adhesive sheet after pasting the structural member for image display apparatus through the adhesive sheet.

Therefore, according to the present invention, even when a light impervious portion such as a printing portion and an constituent member for an image display device having the light transmitting portion in the pasting surface are pasted together, the followability to the step portion and the surface flatness can be obtained. Even in the light opaque portion, distortion and deformation are not generated, and the adherends can be firmly bonded to each other with high cohesive force, and furthermore, the exposed adhesive surface is not sticky even in a harsh environment such as under high temperature and high humidity. It is to provide a new adhesive sheet 2 that may be.

In the present PSA sheet 2, the soft portion having a gel fraction of less than 1% can obtain the followability to the step portion and the surface flatness, and the distortion and deformation in the sheet can be alleviated, while the hard portion having the gel fraction of 40% or more. By this, not only the adhesive surface can be made sticky, but also the adherends can be firmly adhered to each other with high cohesion.

Therefore, for example, even when sticking the light-transmissive part, such as a printing part, and the structural member for image display apparatuses which have a light-transmitting part in a joining surface, the followability and surface flatness with respect to a printing step part can be acquired as a whole adhesive sheet. In addition, even in the light-transmissive portion, distortion and deformation are not generated, and further, the adherends can be firmly bonded to each other with high cohesive force. In addition, by making the exposed adhesive surface a hard part, the exposed adhesive surface can be prevented from sticking even in a harsh environment such as under high temperature and high humidity.

As shown in FIG. 1 or FIG. 2, this adhesive sheet 2 may be the form which has the said soft part and a hard part in the sheet surface of an adhesive sheet, and also shows (A), (B) or FIG. As shown in 5, the form in which the cross section of at least one side of an adhesive sheet has the said hard part may be sufficient. At this time, the sheet surface of the adhesive sheet may be soft or hard. In addition, as shown in FIG. 5, the form in which the cross section of the at least one side of the adhesive sheet wound in roll shape may have the said hard part may be sufficient.

"Base polymer" in the present invention means the resin that forms the main component of the pressure-sensitive adhesive composition forming each layer. Although it does not prescribe the specific content of a base polymer, As a reference | standard, 50 mass% or more of resin contained in the adhesive composition which forms each layer, especially 80 mass% or more, especially 90 mass% or more (100 mass% is included) Resin). In addition, when there are two or more types of base polymers, those total amounts correspond to the said content.

The gel fraction of the soft portion is preferably less than 1%, particularly less than 0.8%, and particularly less than 0.5%, from the standpoint of followability to the step portion, surface flatness, and furthermore, distortion and deformation in the sheet. Especially preferred.

On the other hand, the gel fraction of the hard part is preferably 40% or more, from the viewpoint that the adhesive surface is not sticky even under severe environments such as high temperature, high humidity, and exhibits high cohesive force and improves adhesiveness. Especially, it is especially preferable that it is 50% or more.

Further, if the glass transition temperature (Tg [S]) of the soft portion measured using a differential scanning calorimeter (DSC) is -70 to -10 ° C, the Tg of the soft portion has moderate flexibility and self-adhesion in the normal temperature region. It is preferable that it is -70-10 degreeC, Especially, it is especially preferable that it is -65 degreeC or more or -15 degreeC or less, Especially, it is -60 degreeC or more or -20 degreeC or less.

On the other hand, when the glass transition temperature (Tg [H]) of the hard part measured using a differential scanning calorimeter (DSC) is -60 to + 10 ° C, high cohesive force can be obtained, so that the Tg of the hard part is -60 to It is preferable that it is +20 degreeC, and it is especially preferable that it is -55 degreeC or more or +15 degreeC or less, especially -50 degreeC or more or +10 degreeC or less.

In addition, when the difference (Tg [H] -Tg [S]) between the glass transition temperature (Tg [S]) of the soft portion and the glass transition temperature (Tg [H]) of the hard portion is 3 ° C or more, the betrayal quality of flexibility and cohesion force is achieved. As a result of being able to make it compatible at a higher level, it is preferable because the following can be compatible with the adhered surface during bonding and excellent foaming reliability after the laminate is obtained. Therefore, it is preferable that the difference (Tg [H] -Tg [S]) of the glass transition temperature (Tg [H]) of a hard part is 3 degreeC or more, and it is especially preferable that it is 5 degreeC or more, especially 7 degreeC or more.

(Asuka hardness of the soft part)

When the Asuka hardness (c) of the soft part in this adhesive sheet 2 is 10 or more, since the suitable hardness related to cutting workability and the ease of processing is obtained, it is preferable. Moreover, since the said Asuka hardness (c) is less than 60, since moderate flexibility and adhesiveness to a to-be-adhered body are obtained, it is preferable.

From such a viewpoint, it is preferable that the asuka hardness (c) of the soft part in this adhesive sheet 2 is 10 or more and less than 60, and it is especially preferable that it is 15 or more or 55 or less, especially 20 or more or 50 or less.

 (Asuka hardness of the hard part)

When the Asuka hardness (d) of the hard part in this adhesive sheet 2 is 40 or more, high cohesion force is obtained and the laminated body excellent in shape stability and foaming resistance can be obtained. Moreover, since the said Asuka hardness (d) is less than 90, since the laminated body which does not fall too much and is excellent in impact resistance is obtained, it is preferable.

From such a viewpoint, it is preferable that the Asuka hardness (d) of the hard part in this adhesive sheet 2 is 40 or more and less than 90, and it is especially preferable that it is 43 or more and 88 or less, especially 45 or more or 85 or less.

Furthermore, in this adhesive sheet 2, since said (d)-(c) is 20 or more, since the followability to the to-be-adhered surface at the time of pasting can be compatible, the excellent foaming reliability after making it a laminated body is compatible. Do.

From this viewpoint, in this adhesive sheet 2, it is preferable that the difference ((d)-(c)) of the Asuka hardness (c) of a soft part and the Asuka hardness (d) of a hard part is 20 or more, Especially, 20 or more or 80 Hereinafter, especially, it is especially preferable that they are 25 or more or 75 or less.

In this adhesive sheet 2, in order to adjust the Asuka hardness (c) of a soft part, and the Asuka hardness (d) of a hard part, in a composition and the manufacturing method, the composition ratio of a crosslinking agent and a photoinitiator is adjusted, or the amount of light irradiation to an adhesive composition is adjusted. You can adjust it. However, it is not limited to such a method.

(180 ° peel force of soft part)

Since the 180 degree peeling force of the soft part in this adhesive sheet 2 is 3 N / cm or more, since it has moderate adhesiveness with respect to a to-be-adhered body at normal temperature, and is excellent in a bonding workability, it is preferable.

From these viewpoints, it is preferable that 180 degree peeling force of the soft part in this adhesive sheet 2 is 3 N / cm or more, and it is especially preferable that it is 20 N / cm or less, especially 4 N / cm or more or 15 N / cm or less.

(180 ° peeling force of the hard part)

Since the 180 degree peeling force of the hard part in this adhesive sheet 2 is 5 N / cm or more, since excellent foam-resistant peeling property is obtained, it is preferable.

From such a viewpoint, it is preferable that the 180 degree peeling force of the hard part in this adhesive sheet 2 is 5 N / cm or more, and it is especially preferable that it is 25 N / cm or less, especially 6 N / cm or more or 20 N / cm or less.

In this adhesive sheet 2, in order to adjust the 180 degree peeling force of a soft part and a hard part, in a composition and the manufacturing method, the kind and composition ratio of a crosslinking agent and a photoinitiator are adjusted, or the heating and pressurization conditions at the time of bonding, or affixing are carried out. What is necessary is just to adjust the following light irradiation conditions. However, it is not limited to such a method.

(40 degrees Celsius holding power of the soft part)

When the holding force in the temperature of 40 degreeC of the soft part in this adhesive sheet 2 is less than shift | offset length 10 mm, the outstanding workability and storage stability can be obtained.

From such a viewpoint, it is preferable that a shift | offset | difference length in temperature of 40 degreeC of the soft part in this adhesive sheet 2 is less than 10 mm, and it is more preferable that it is less than 8 mm and especially less than 5 mm especially.

 (70 degrees Celsius holding power of the soft part)

Moreover, when the adhesion surface shifts and falls further in less than 10 minutes with respect to the holding force in the temperature of 70 degreeC of the soft part in this adhesive sheet 2, the outstanding adhesiveness with respect to the to-be-adhered body at the time of sticking, and the uneven absorption property It is preferable because it is obtained.

From such a viewpoint, about the holding force in the temperature of 70 degreeC of the soft part in this adhesive sheet 2, an adhesion surface shifts and falls further in less than 10 minutes, and an adhesion surface shifts and adds in less than 8 minutes especially. It is more preferable to fall, and it is more preferable that an adhesion surface shifts more than less than 6 minutes especially.

(40 degrees Celsius or 70 degrees Celsius holding power of the hard part)

As for the holding force in the temperature of 40 degreeC and 70 degreeC of the hard part in this adhesive sheet 2, it is preferable that a shift length is less than 1 mm, It is more preferable that it is less than 0.7 mm, It is more preferable that it is less than 0.5 mm.

When the holding force in the temperature of 40 degreeC and 70 degreeC of the hard part in this adhesive sheet 2 is the said range, high cohesion force is obtained and shape stability in a wet heat environment, and foaming reliability can be obtained.

<Production method of this adhesive sheet 2>

This adhesive sheet 2 can be produced as follows.

(1) A part coated with a light impermeable member when the light is irradiated while covering the photocurable pressure sensitive adhesive sheet by covering the portion of the soft portion with a light impermeable member, that is, a member which does not pass light used for photocuring. It can be made into a soft part, and the part which is not coat | covered with the light impermeable member, ie, the part irradiated with light, can be hardened by photocuring.

(2) Moreover, if light is irradiated to the end surface of an adhesive sheet, and light is not irradiated to parts other than the said end surface part, the said end surface part may be made a hard part, and another part may be made a soft part.

For example, light may be irradiated from the vertical direction, the horizontal direction, or the oblique vertical direction (assuming that the front and rear of the sheet is disposed in the vertical up and down direction) with respect to the end face portion of the pressure sensitive adhesive sheet. On the other hand, sheets which do not pass light used for photocuring may be laminated, and light may be irradiated from the vertical direction, the horizontal direction, or the oblique vertical direction. When light is irradiated in this way, it is possible to photocure the cross section of an adhesive sheet. At this time, as the sheet which does not pass light used for photocuring, a UV absorber is placed in a release sheet using polyethylene terephthalate as a base polymer, a polyethylene terephthalate film or a polyolefin film, or a UV absorber is applied to the surface. It is particularly suitable to use a release sheet that does not pass light used for photocuring, such as a release sheet using a film.

In addition, when irradiated with light, the cross-sectional part and its peripheral part may be a hard part.

(3) Moreover, even if the adhesive sheets which respectively have a desired gel fraction are produced separately and both are integrated, the soft part and hard part can be formed in an adhesive sheet.

<Adhesive sheet X>

This adhesive sheet 2 can be formed by partially photocuring using the following adhesive sheet X. However, it is not limited to what forms this adhesive sheet 2 using the following adhesive sheet X. FIG.

It is particularly preferable that the adhesive sheet X has a gel fraction (a) of less than 1%, especially less than 0.8%, and particularly less than 0.5%, from the viewpoint of developing hot melt properties in the state before photocuring.

Moreover, since the adhesive sheet X can obtain high cohesion force after photocuring, and foaming reliability in a wet heat environment is obtained, it is preferable that the gel fraction (b) after photocuring is 40% or more, and 45% or more of these, or It is especially preferable that it is 95% or less, especially 50% or more or 90% or less.

In order to adjust the gel fraction (a) before photocuring and the gel fraction (b) after photocuring as mentioned above, in a composition and the manufacturing method, the composition ratio of a crosslinking agent and a photoinitiator is adjusted, or the temperature and the amount of light irradiation at the time of a process are adjusted. Just do it. However, it is not limited to such a method.

<This adhesive composition 2>

The resin composition (henceforth "this adhesive composition 2") which can be used suitably for forming the said adhesive sheet X is demonstrated. However, it is an example to the last and is not limited to this.

As this adhesive composition 2, it is preferable that it is a photocurable adhesive composition. Especially, it is preferable that it is a resin composition containing a (meth) acrylic-type copolymer (2-A), a crosslinking agent (2-B), and a photoinitiator (2-C).

However, as mentioned above, if the gel fraction after sticking can be changed according to the site | part inside an adhesive sheet, it does not limit the composition of the adhesive composition for forming this adhesive sheet 2. As shown in FIG.

Here, this adhesive sheet 2 can hold | maintain a sheet shape in a normal state, and it has a hot-melt property which melts or flows when it heats in an uncrosslinked state, and is a adhesive sheet which has photocurability which can be photocurable. Especially preferred.

If the sheet shape can be held in the normal state, the handling is easier than the liquid adhesive, and the operation of filling the liquid can be omitted, which is particularly excellent in productivity.

In addition, in a normal state, that is, near room temperature, if it is equipped with the moderate adhesiveness, ie, the property of adhering to a to-be-adhered body in a short time with light force (called "tackiness"), it will be easy to perform positioning at the time of sticking, It is preferable to have tackiness in a normal state, ie, room temperature vicinity from the point which is excellent in the property, and it is more preferable if it has tackiness also in the comparatively low temperature area | region of -5 degreeC-20 degreeC.

Moreover, if it has a hot melt property which melts or flows when it heats, by heating and softening or fluidizing it, it can harvest to an uneven | corrugated part, such as a printing step, and can fill an adhesive, and can fill it without generating foaming etc. .

Furthermore, if it has photocurability, it can be reliably adhere | attached by finally photocuring.

Thus, in order to produce the adhesive sheet which can hold | maintain a sheet shape in a normal state, and melts and flows when it heats in an uncrosslinked state, and can be photocurable, for example, single layer adhesion If it is a sheet, what is necessary is just to produce the single layer adhesive sheet from the adhesive composition (2-I) or (2-II) demonstrated next. On the other hand, when it is set as a multilayer adhesive sheet, for example, the 2 type 2-layer structure which laminated | stacked the adhesive layer which consists of adhesive composition (2-I) or (2-II), and the adhesive layer which consists of another adhesive composition, Two kinds of three-layered constitution which arrange | positioned the adhesive layer which consists of adhesive composition (2-I) or (2-II) on the front and back via an intermediate resin layer, and an adhesive composition (2-I) or (2-II) Three types of three-layered constitution etc. which consist of laminating | stacking the adhesion layer which consists of an intermediate | middle layer consisting of an intermediate resin composition, and the adhesion layer which consists of another adhesive composition in this order are mentioned.

However, the adhesive composition for forming this adhesive sheet 2 is not limited to adhesive composition (2-I) or (2-II).

<Adhesive Composition (2-I)>

As an adhesive composition (2-I), it contains the acryl-type copolymer (2-A1) which consists of a graft copolymer provided with a macromonomer as a branch component, a crosslinking agent (2-B1), and a photoinitiator (2-C1). A resin composition is mentioned.

 (Acrylic Copolymer (2-A1))

The acrylic copolymer (2-A1) as the base polymer may be a graft copolymer having a macromonomer as a branch component.

(Stem component)

It is preferable that the stem component of the said acrylic copolymer (2-A1) is comprised from the copolymer component containing the repeating unit derived from (meth) acrylic acid ester.

It is preferable that the glass transition temperature of the copolymer which comprises the stem component of the said acrylic copolymer (2-A1) is -70-0 degreeC.

At this time, the glass transition temperature of the copolymer component which comprises a stem component refers to the glass transition temperature of the polymer obtained by copolymerizing only the monomer component which comprises the stem component of an acryl-type copolymer (2-A1). Specifically, the value calculated by Fox's calculation formula from the glass transition temperature and composition ratio of the polymer obtained from the homopolymer of each component of the said copolymer is meant.

In addition, the calculation formula of Fox is a calculated value calculated | required by the following formula | equation, and can be calculated | required using the value described in a polymer handbook (Polymer HandBook, J. Brandrup, Interscience, 1989).

1 / (273 + Tg) = Σ (Wi / (273 + Tgi))

[Wherein, Wi represents the weight fraction of the monomer i, Tgi represents the Tg (° C.) of the homopolymer of the monomer i.]

The glass transition temperature of the copolymer component which comprises the stem component of the said acrylic copolymer (2-A1) is the softness | flexibility of the adhesive composition (2-I) in a room temperature state, and the adhesive composition (2-I) with respect to a to-be-adhered body. In order to obtain wettability, i.e., adhesiveness, the glass transition temperature is preferably -70 ° C to 0 ° C, in order for the pressure-sensitive adhesive composition (2-I) to obtain appropriate adhesion (tackiness) at room temperature. It is especially preferable that they are -65 degrees C or more or -5 degrees C or less, especially -60 degrees C or more or -10 degrees C or less.

However, even if the glass transition temperature of the said copolymer component was the same temperature, viscoelasticity can be adjusted by adjusting molecular weight. For example, it can be made more flexible by making the molecular weight of a copolymer component small.

As a (meth) acrylic acid ester monomer which the stem component of the said acrylic copolymer (2-A1) contains, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and isopropyl ( Meta) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl ( Meta) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl Acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylic Late, lau Reel (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, 2- Phenoxyethyl (meth) acrylate, 3,5,5-trimethylcyclohexaneacrylate, p-cumylphenol EO-modified (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylic Elate, dicyclopentenyloxyethyl (meth) acrylate, benzyl (meth) acrylate, etc. are mentioned. It contains hydroxyl groups, such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and glycerol (meth) acrylate which have a hydrophilic group and an organic functional group, etc. in these (meth) Acrylate, (meth) acrylic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxypropyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2 -(Meth) acryloyloxypropylphthalic acid, 2- (meth) acryloyloxyethyl maleic acid, 2- (meth) acryloyloxypropyl maleic acid, 2- (meth) acryloyloxyethyl succinic acid, 2 Carboxyl group-containing monomers such as (meth) acryloyloxypropylsuccinic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleic acid, monomethyl itaconic acid, and acid anhydride groups such as maleic anhydride and itaconic anhydride Monomer, glycidyl (meth) acrylate, -Amino-group-containing (meth) acrylic acid ester, such as epoxy-group-containing monomers, such as glycidyl ethyl acrylate and 3, 4- epoxybutyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and diethylaminoethyl (meth) acrylate System monomer, (meth) acrylamide, Nt-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, Heterocyclic basic monomers, such as monomer containing amide groups, such as diacetone acrylamide, maleic acid amide, and maleimide, vinylpyrrolidone, vinyl pyridine, and vinyl carbazole, etc. can also be used.

Furthermore, styrene, t-butyl styrene, (alpha) -methylstyrene, vinyltoluene, acrylonitrile, methacrylonitrile, vinyl acetate, a vinyl propionate, alkyl vinyl ether, and hydroxyalkyl which can be copolymerized with the said acryl monomer and methacryl monomer are mentioned. Various vinyl monomers, such as a vinyl ether and an alkyl vinyl monomer, can also be used suitably.

Moreover, it is preferable that the stem component of an acryl-type copolymer (2-A1) contains a hydrophobic (meth) acrylate monomer and a hydrophilic (meth) acrylate monomer as a structural unit.

If the stem component of the acrylic copolymer (2-A1) is composed of only hydrophobic monomers, the tendency to wet heat whitening is recognized. Therefore, it is preferable to introduce a hydrophilic monomer into the stem component to prevent wet heat whitening.

Specifically, as the stem component of the acrylic copolymer (2-A1), a hydrophobic (meth) acrylate monomer, a hydrophilic (meth) acrylate monomer, and a polymerizable functional group at the terminal of the macromonomer are randomly copolymerized. The copolymer component which consists of is mentioned.

Here, as said hydrophobic (meth) acrylate monomer, the alkyl ester which does not have a polar group (except methyl acrylate) is preferable, For example, n-butyl (meth) acrylate and isobutyl (meth) ) Acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylic Latex, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, ste Aryl (meth (2) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate And methyl methacrylate.

Moreover, as a hydrophobic vinyl monomer, vinyl acetate, styrene, t-butyl styrene, (alpha) -methylstyrene, vinyltoluene, an alkyl vinyl monomer, etc. are mentioned, for example.

As said hydrophilic (meth) acrylate monomer, methyl acrylate and ester which has a polar group are preferable, For example, methyl acrylate, (meth) acrylic acid, tetrahydrofurfuryl (meth) acrylate, and hydroxyethyl Hydroxyl-containing (meth) acrylates, such as (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and glycerol (meth) acrylate, (meth) acrylic acid, and 2- (meth) ) Acryloyloxyethylhexahydrophthalic acid, 2- (meth) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxypropylphthalic acid, 2- (Meth) acryloyloxyethyl maleic acid, 2- (meth) acryloyloxypropyl maleic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxypropyl succinic acid, crotonic acid , Fumaric acid, maleic acid, Carboxyl group-containing monomers such as taconic acid, monomethyl maleic acid and monomethyl itaconic acid, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride, glycidyl (meth) acrylate, glycidyl (alpha) -ethyl acrylate, ( Alkoxy polyalkylene glycol (meth) acrylates, such as epoxy group containing monomers, such as 3, 4- epoxy butyl methacrylate, and methoxy polyethylene glycol (meth) acrylate, N, N- dimethyl acrylamide, hydroxyethyl acrylamide And the like.

(Branch ingredient: macromonomer)

It is preferable that an acryl-type copolymer (2-A1) introduce | transduces a macromonomer as a branch component of a graft copolymer, and contains the repeating unit derived from a macromonomer.

A macromonomer is a high molecular monomer which has a terminally polymerizable functional group and a high molecular weight skeleton component.

It is preferable that the glass transition temperature (Tg) of a macromonomer is higher than the glass transition temperature of the copolymer component which comprises the said acrylic copolymer (2-A1).

Specifically, since the glass transition temperature (Tg) of the macromonomer affects the heat melting temperature (hot melt temperature) of the pressure-sensitive adhesive composition (2-I), the glass transition temperature (Tg) of the macromonomer is 30 ° C to 120 ° C. It is preferable that it is ° C, and particularly preferably 40 ° C or more or 110 ° C or less, and more preferably 50 ° C or more or 100 ° C or less.

If it is such a glass transition temperature (Tg), while being excellent in workability and storage stability by adjusting molecular weight, it can adjust so that it may hot melt in 80 degreeC vicinity.

The glass transition temperature of a macromonomer refers to the glass transition temperature of the said macromonomer itself, and can measure it with a differential scanning calorimeter (DSC). (The temperature rising rate: 5 degree-C / min, Tg is measured from the inflection point of a baseline shift)

In addition, in a room temperature state, in order that branch components may mutually attract each other and physically bridge | crosslink as an adhesive composition, it may be maintained, and in addition, in order that said physical crosslinking may be loosened and fluidity may be obtained by heating to moderate temperature, a macromonomer It is also preferable to adjust the molecular weight and content of the resin.

From such a viewpoint, it is preferable to contain a macromonomer in the ratio of 5 mass%-30 mass% in an acryl-type copolymer (2-A1), Especially, 6 mass% or more or 25 mass% or less, 8 mass% is especially It is preferable that it is more than 20 mass%.

Moreover, it is preferable that the number average molecular weights of a macromonomer are 500 or more and less than 8000, and especially, it is preferable that they are 800 or more or less than 7500, especially 1000 or more or less than 7000.

As a macromonomer, what is generally manufactured (for example, the macromonomer made from the same synthetic synthetic company etc.) can be used suitably.

It is preferable that the high molecular weight skeleton component of a macromonomer is comprised from an acryl-type polymer or a vinyl type polymer.

As a high molecular weight skeleton component of the said macromonomer, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate Isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, Hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (meth) acrylate, isononyl ( Meth) acrylate, t-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) Acryl Yate, stearyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, 3,5 , 5-trimethylcyclohexane acrylate, p-cumylphenol EO-modified (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylic Latex, benzyl (meth) acrylate, hydroxyalkyl (meth) acrylate, (meth) acrylic acid, glycidyl (meth) acrylate, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, ( (Meth) acrylate monomers such as meta) acrylonitrile, alkoxyalkyl (meth) acrylate, alkoxypolyalkylene glycol (meth) acrylate, styrene, t-butylstyrene, α-methylstyrene, vinyltoluene, alkyl Vinyl monomer, vinyl acetate, alkyl vinyl Various vinyl monomers, such as an ether and hydroxyalkyl vinyl ether, etc. are mentioned, These can be used individually or in combination of 2 or more types.

As a terminal polymerizable functional group of the said macromonomer, a methacryloyl group, acryloyl group, a vinyl group, etc. are mentioned, for example.

(Cross-linking system (2-B1))

As a crosslinking agent (2-B1), the crosslinking agent which has two or more crosslinkable groups, such as an epoxy group, an isocyanate group, an oxetane group, a silanol group, and a (meth) acryloyl group, can be selected suitably, for example. Especially, from the point of reactivity and the intensity | strength of the hardened | cured material obtained, it has a polyfunctional (meth) acrylate which has two or more (meth) acryloyl groups, three or more especially, an epoxy group, an isocyanate group, and a silanol group (meth ) Acrylates are preferred.

After integrating the constituent members for the image display device and then crosslinking the crosslinking agent (2-B1) in the adhesive, the sheet exhibits high cohesive force under a high temperature environment, instead of losing hot meltability, and excellent foaming resistance. Reliability can be obtained.

As such (meth) acrylate, 1, 4- butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerin di (meth) acrylate, glycerin glycidyl ether di (meth), for example ) Acrylate, 1,6-hexanedioldi (meth) acrylate, 1,9-nonanedioldi (meth) acrylate, tricyclodecanedimethanoldi (meth) acrylate, bisphenol A polyethoxydi (meth ) Acrylate, bisphenol A polyalkoxydi (meth) acrylate, bisphenol F polyalkoxydi (meth) acrylate, polyalkylene glycoldi (meth) acrylate, trimethylolpropanetrioxyethyl (meth) acrylate, ε -Caprolactone modified tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated pentaery Thritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, propoxylated pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate , Polyethylene glycol di (meth) acrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate , Hydroxypivalic acid neopentyl glycol di (meth) acrylate, di (meth) acrylate of ε-caprolactone adduct of hydroxypivalic acid neopentyl glycol, trimethylol propane tri (meth) acrylate, alkoxylated trimethylol Ultraviolet curing type such as propane tri (meth) acrylate and ditrimethylol propane tetra (meth) acrylate In addition to the polyfunctional monomers, polyfunctional acrylic oligomers such as polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, polyether (meth) acrylate, isocyanate (meth) acrylate, 1,1- (bis (meth) acryloyloxymethyl) ethyl isocyanate, 2- (2- (meth) acryloyloxyethyloxy) ethyl isocyanate, glycidyl (meth) acrylate, hydroxyethyl acrylate Glycidyl ether, hydroxypropyl (meth) acrylate glycidyl ether, hydroxybutyl (meth) acrylate glycidyl ether, and the like.

Among the above-mentioned, the polyfunctional monomer or oligomer containing polar functional groups, such as a hydroxyl group, is preferable from a viewpoint of improving the adhesiveness to a to-be-adhered body, and the effect of suppressing wet heat whitening.

Especially, it is preferable to use the polyfunctional (meth) acrylic acid ester which has a hydroxyl group or a carboxyl group.

Therefore, from the viewpoint of preventing wet heat whitening, it is preferable to contain a hydrophobic acrylate monomer and a hydrophilic acrylate monomer as the stem component of the acrylic copolymer (2-A1), that is, the graft copolymer. It is preferable to use the polyfunctional (meth) acrylic acid ester which has a hydroxyl group as a crosslinking agent (2-B).

The content of the crosslinking agent (2-B1) is not particularly limited. As a standard, it is 0.5-20 mass parts with respect to 100 mass parts of acrylic copolymers (2-A1), 1 mass part or more or 15 mass parts or less especially, It is preferable that it is the ratio of 2 mass parts or more or 10 mass parts or less especially. Do.

By containing a crosslinking agent (2-B1) in the said range, the shape stability of this adhesive sheet 2 in an uncrosslinked state, and the foaming reliability in the adhesive material after crosslinking can be made compatible. However, you may exceed this range by balance with another element.

(Photoinitiator (2-C1))

A photoinitiator (2-C1) functions as a reaction start adjuvant in the crosslinking reaction of the above-mentioned crosslinking agent (2-B1).

As a photoinitiator, a well-known thing can be used suitably now. Especially, the photoinitiator sensitive to the ultraviolet-ray of wavelength 380 nm or less is preferable from a viewpoint of the controllability of a crosslinking reaction.

On the other hand, the photoinitiator which responds to the light of long wavelength rather than wavelength 380nm is preferable at the point which the light which it senses easily reaches to the core part of this adhesive sheet 2.

The photopolymerization initiator is largely classified into two by radical generating mechanisms, and a cleavage type photopolymerization initiator capable of generating a radical by cleaving a single bond of the photopolymerizable initiator itself, a photoexcited initiator, and a hydrogen donor in the system are excited complexes. To form a hydrogen-based photopolymerization initiator capable of transferring the hydrogen of the hydrogen donor.

Among these, the cleavage type photopolymerization initiator decomposes when generating radicals by light irradiation to form another compound, and once excited, it does not have a function as a reaction initiator. For this reason, since it does not remain as active species in the adhesive material after completion | finish of crosslinking reaction, since it is unlikely to cause unexpected light deterioration etc. in an adhesive material, it is preferable.

On the other hand, since the hydrogen-drawn photoinitiator does not generate decomposition products such as cleavage photoinitiators during radical generation reaction by active energy ray irradiation such as ultraviolet rays, it is difficult to become a volatile component after completion of the reaction. It is useful in that damage can be reduced.

As said cleavage type photoinitiator, 2, 2- dimethoxy- 1, 2- diphenyl ethanol 1-one, 1-hydroxy cyclohexyl phenyl ketone, 2-hydroxy-2- methyl-1-phenyl -Propan-1-one, 1- (4- (2-hydroxyethoxy) phenyl) -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- [4- {4- (2-hydroxy-2-methyl-propionyl) benzyl} phenyl] -2-methyl-propane-1-one, oligo (2-hydroxy-2-methyl-1- (4- (1- Methylvinyl) phenyl) propanone), methyl phenylglyoxylate, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2-methyl-1- [4- ( Methylthio) phenyl] -2-morpholinopropane-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl]- 1-butanone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, derivatives thereof, and the like.

As said hydrogen draw type photoinitiator, it is benzophenone, 4-methyl- benzophenone, 2,4,6-trimethyl benzophenone, 4-phenylbenzo phenone, 3,3'- dimethyl- 4-methoxy benzophenone, for example. , 4- (meth) acryloyloxybenzophenone, methyl 2-benzoylbenzoate, methyl benzoyl formate, bis (2-phenyl-2-oxoacetic acid) oxybisethylene, 4- (1,3-acryloyl-1 , 4,7,10,13-pentaoxotridecyl) benzophenone, thioxanthone, 2-chlorothioxanthone, 3-methylthioxanthone, 2,4-dimethylthioxanthone, 2-methylanthraquinone, 2-ethyl anthraquinone, 2-tert- butyl anthraquinone, 2-aminoanthraquinone, its derivatives, etc. are mentioned.

However, it is not limited to the above-mentioned substance as a photoinitiator. Any one of the above-mentioned cleavage type photopolymerization initiator and a hydrogen extraction type photopolymerization initiator may be used, or may be used in combination of 2 or more type.

The content of the photopolymerization initiator (2-C1) is not particularly limited. As a reference | standard, 0.1-10 mass parts with respect to 100 mass parts of acrylic copolymers (2-A1), and 0.5 mass part or more or 5 mass parts or less, especially, contain in a ratio of 1 mass part or more or 3 mass parts or less. It is preferable.

By making content of a photoinitiator (2-C1) into the said range, suitable reaction sensitivity with respect to an active energy ray can be obtained.

(Other ingredients)

An adhesive composition (2-I) may contain the well-known component mix | blended with a normal adhesive composition as a component of that excepting the above. For example, if necessary, various additives such as tackifier resins, antioxidants, light stabilizers, metal deactivators, anti-aging agents, moisture absorbents, polymerization inhibitors, ultraviolet absorbers, rust inhibitors, silane coupling agents, inorganic particles, etc. may be appropriately contained. It is possible to let.

Moreover, you may contain suitably a reaction catalyst (a tertiary amine compound, a quaternary ammonium compound, a lauryl acid tin compound etc.) as needed.

<Adhesive Composition (2-II)>

As an adhesive composition (2-II), monomer a whose glass transition temperature (Tg) is less than 0 degreeC, monomer b whose glass transition temperature (Tg) is 0 degreeC or more and less than 80 degreeC, and glass transition temperature (Tg) are 80 degreeC or more Monomer c is copolymerized in the molar ratio of a: b: c = 10-40: 90-35: 0-25, and contains the (meth) acrylic acid ester copolymer or vinyl copolymer of the weight average molecular weight 50000-400000. The resin composition containing the (meth) acrylic-type copolymer (2-A2), a crosslinking agent (2-B2), and a photoinitiator (2-C2) mentioned above is mentioned.

In addition, a number average molecular weight and a weight average molecular weight use gel permeation chromatography (GPC), and the conversion value using polystyrene as a reference | standard substance is employ | adopted.

((Meth) acrylic copolymer (2-A2))

It is preferable that the (meth) acrylic-type copolymer (2-A2) as a base polymer is a (meth) acrylic acid ester copolymer or a vinyl copolymer.

It is preferable that the said (meth) acrylic acid ester copolymer or a vinyl copolymer is 50000-400000, and the weight average molecular weight is 60000 or more and 350000 or less from the viewpoint of making shape retention property and hot melt property compatible at room temperature, It is more preferable that it is 70000 or more or 300000 or less among these.

In the acrylic ester copolymer, appropriately adjusting the physical properties such as glass transition temperature (Tg) and molecular weight by appropriately selecting the kind, composition ratio, and polymerization conditions of the acrylic monomer and methacryl monomer used to adjust this. It is possible.

At this time, as an acryl monomer which comprises an acrylate ester copolymer, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, n-butyl acrylate, ethyl acrylate etc. are mentioned as a main raw material, for example. have.

In addition to these, the (meth) acryl monomer having various functional groups may be copolymerized with the acryl monomer in accordance with the purpose of imparting cohesive force or imparting polarity.

As the (meth) acryl monomer having the functional group, for example, methyl methacrylate, methyl acrylate, hydroxyethyl acrylate, acrylic acid, glycidyl acrylate, N-substituted acrylamide, acrylonitrile, methacryl Nitrile, fluorine-containing alkyl acrylate, organosiloxy group-containing acrylate and the like.

On the other hand, as a vinyl copolymer, the vinyl copolymer formed by superposing | polymerizing also various vinyl monomers, such as vinyl acetate which can be copolymerized with the said acryl monomer and methacryl monomer, and alkyl vinyl ether, hydroxyalkyl vinyl ether, is mentioned suitably.

As a (meth) acrylic-type copolymer (2-A2) of this adhesive sheet 2, monomer a whose glass transition temperature (Tg) is less than 0 degreeC, monomer b whose glass transition temperature (Tg) is 0 degreeC or more and less than 80 degreeC, and glass It is preferable that the monomer c whose transition temperature (Tg) is 80 degreeC or more is a (meth) acrylic acid ester copolymer or vinyl copolymer formed by copolymerizing in the molar ratio of a: b: c = 10-40: 90-35: 0-25. Do.

At this time, each glass transition temperature (Tg) of monomers a, b, and c is the meaning of each glass transition temperature (Tg) at the time of preparing a polymer from the said monomer (homopolymerization).

It is preferable that the said monomer a is a (meth) acrylic acid ester monomer which has an alkyl group structure which has a C4 or more side chain, for example.

At this time, the side chains having 4 or more carbon atoms may be made of straight chains or may be made of branched carbon chains.

More specifically, it is preferable that the said monomer a is a (meth) acrylic acid ester monomer which has a C4-C10 linear alkyl group structure, or is a (meth) acrylic acid ester monomer which has a C6-C18 branched alkyl group structure. .

Here, as "(meth) acrylic acid ester monomer which has a C4-C10 linear alkyl group structure", n-butyl acrylate, n-hexyl acrylate, n-octyl acrylate, n-nonyl acrylate, n-decyl acryl The rate etc. are mentioned.

In addition, as "(meth) acrylic acid ester monomer which has a C6-C18 branched alkyl group structure", 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-methylhexyl acrylate, isooctyl acrylate, iso Nonyl acrylate, isodecyl acrylate, isodecyl methacrylate, etc. are mentioned.

The monomer b is preferably a (meth) acrylic acid ester monomer having 4 or less carbon atoms, a (meth) acrylic acid ester monomer having a cyclic skeleton in the side chain, a vinyl monomer having 4 or less carbon atoms, or a vinyl monomer having a cyclic skeleton in the side chain. .

Especially, it is especially preferable that the said monomer b is a vinyl monomer whose carbon number of a side chain is four or less.

Here, as "the C4 or less (meth) acrylic acid ester monomer", methyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n -Butyl methacrylate, t-butyl acrylate, isobutyl acrylate, isobutyl methacrylate, etc. are mentioned.

As "(meth) acrylic acid ester monomer which has a cyclic skeleton in a side chain", isobornyl acrylate, cyclohexyl acrylate, cyclohexyl methacrylate, 1, 4- cyclohexane dimethanol monoacrylate, tetrahydrofurfuryl meta Acrylate, benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, 2-hydroxy-3-phenoxypropyl acrylate, 3,3,5-trimethylcyclohexanol acrylate , Cyclic trimethylolpropane formal acrylate, 4-ethoxylated cumylphenol acrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentenyl acrylate, and the like. .

Examples of the "vinyl monomer having 4 or less carbon atoms" include vinyl acetate, vinyl propionate, vinyl butyrate, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, and the like.

Examples of the "vinyl monomer having a cyclic skeleton in the side chain" include styrene, cyclohexyl vinyl ether, norbornyl vinyl ether, norbornenyl vinyl ether, and the like. Especially, the vinyl monomer whose carbon number of a side chain is four or less, or the acrylic ester monomer whose carbon number of a side chain is four or less is especially suitable.

It is preferable that the said monomer c is a (meth) acrylic acid ester monomer whose carbon number of a side chain is 1 or less, or the (meth) acrylic acid ester monomer which has a cyclic skeleton in a side chain.

Here, as a "(meth) acrylic acid ester monomer whose carbon number of a side chain is 1 or less", methyl methacrylate, acrylic acid, methacrylic acid, etc. are mentioned.

As "(meth) acrylic acid ester monomer which has a cyclic skeleton in a side chain", isobornyl methacrylate, 3,3,5-trimethylcyclohexyl methacrylate, dicyclopentanyl acrylate, dicyclopentanyl methacrylate, and dish Clofentenyl methacrylate etc. are mentioned.

(Meth) which (meth) acrylic-type copolymer (2-A2) copolymerizes monomer a, monomer b, and monomer c in the molar ratio of a: b: c = 10-40: 90-35: 0-25 If the acrylic ester copolymer or vinyl copolymer is included, the peak of Tan δ can be adjusted to 0 to 20 ° C., and the sheet-like shape can be retained in a normal state, that is, at room temperature. In addition, the adhesiveness (called "tackiness") of the peelable grade can be expressed. Moreover, when heated to the temperature which can be hot melted, fluidity | liquidity will express and it can follow to the step part of a joining surface, and can fill to a corner.

Therefore, from such a viewpoint, the molar ratio of the monomer a, the monomer b, and the monomer c in the (meth) acrylic acid ester copolymer or the vinyl copolymer constituting the (meth) acrylic copolymer (2-A2) is a : b: c = 10-40: 90-35: 0-25 is preferable, Especially it is 13-40: 87-35: 0-23, Especially, it is 15-40: 85-38: 2-20 desirable.

Moreover, from the same viewpoint as the above, the molar ratio of the monomer a, the monomer b, and the monomer c in the (meth) acrylic acid ester copolymer or vinyl copolymer which comprises a (meth) acrylic-type copolymer (2-A2) is , b> a> c.

(Cross-linking system (2-B2))

By crosslinking agent (2-B2) in this adhesive sheet 2, this adhesive sheet 2 expresses high cohesion force in a high temperature environment, and can obtain the outstanding foaming reliability.

As such a crosslinking agent (2-B2), the crosslinking agent which has two or more crosslinkable groups, such as an epoxy group, an isocyanate group, an oxetane group, a silanol group, and a (meth) acryloyl group, can be selected suitably, for example. Especially, from the point of reactivity and the intensity | strength of the hardened | cured material obtained, it has a polyfunctional (meth) acrylate which has two or more (meth) acryloyl groups, three or more especially, an epoxy group, an isocyanate group, and a silanol group (meth ) Acrylates are preferred.

As such (meth) acrylate, 1, 4- butanediol di (meth) acrylate, glycerin di (meth) acrylate, 1, 6- hexanediol di (meth) acrylate, 1, 9- furnace, for example Nandiol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, bisphenol A polypropoxydi (meth) acrylate, bisphenol F polyethoxydi (Meth) acrylate, ethylene glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, epsilon -caprolactone modified tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate , Pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, propoxylated Taerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyethylene glycol di (meth) acrylate, tris (acryloxyethyl) isocyanurate, Dipentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, hydroxy pivalic acid neopentyl glycol di (meth) acrylate, hydroxy pivalic acid neopentyl Di (meth) acrylate of the ε-caprolactone adduct of glycol, trimethylolpropane tri (meth) acrylate, trimethylolpropanepolyethoxytri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate In addition to the ultraviolet curing polyfunctional monomers, polyester (meth) acrylate, epoxy (meth) acrylate, Polyfunctional acrylic oligomers, such as urethane (meth) acrylate and polyether (meth) acrylate, isocyanate (meth) acrylate, 1,1- (bis (meth) acryloyloxymethyl) ethyl isocyanate, 2- ( 2- (meth) acryloyloxyethyloxy) ethyl isocyanate, glycidyl (meth) acrylate, hydroxyethyl acrylate glycidyl ether, hydroxypropyl (meth) acrylate glycidyl ether, hydroxybutyl (Meth) acrylate glycidyl ether is mentioned.

Among the above-mentioned, the polyfunctional monomer or oligomer containing a polar functional group is preferable from a viewpoint of improving the adhesiveness with respect to a to-be-adhered body, the heat resistance, and the effect of suppressing wet heat whitening. Especially, it is preferable to use the polyfunctional (meth) acrylic acid ester which has an isocyanuric ring skeleton.

The content of the crosslinking agent (2-B2) is not particularly limited. As a reference, 0.5-20 mass parts with respect to 100 mass parts of (meth) acrylic-type copolymers (2-A2), 1 mass part or more or 15 mass parts or less, especially the ratio of 2 mass parts or more or 10 mass parts or less Is preferably.

By containing a crosslinking agent (2-B2) in the said range, the shape stability of this adhesive sheet 2 in an uncrosslinked state, and the foaming reliability in the adhesive sheet after crosslinking can be made compatible. However, you may exceed this range by balance with another element.

(Photoinitiator (2-C2))

A photoinitiator (2-C2) functions as a reaction start adjuvant in the crosslinking reaction of the above-mentioned crosslinking agent (2-B2), and the thing of the base material which concerns on the photoinitiator (2-C1) mentioned above can be used suitably. .

The content of the photopolymerization initiator (2-C2) is not particularly limited. As a reference, 0.1-10 mass parts with respect to 100 mass parts of (meth) acrylic-type copolymers (2-A2), and 0.5 mass part or more or 5 mass parts or less, especially 1 mass part or more or 3 mass parts or less ratio It is preferable to contain as.

By making content of a photoinitiator (2-C2) into the said range, suitable reaction sensitivity with respect to an active energy ray can be obtained.

(Other ingredients)

An adhesive composition (2-II) may contain the well-known component mix | blended with a normal adhesive composition as a component of that excepting the above. For example, if necessary, various additives such as tackifier resins, antioxidants, light stabilizers, metal deactivators, anti-aging agents, moisture absorbents, polymerization inhibitors, ultraviolet absorbers, rust inhibitors, silane coupling agents, inorganic particles, etc. may be appropriately contained. It is possible to let.

Moreover, you may contain suitably a reaction catalyst (a tertiary amine compound, a quaternary ammonium compound, a lauryl acid tin compound etc.) as needed.

<Method of Making Adhesive Sheet X>

The method of creating the pressure-sensitive adhesive sheet X is a solution coating method in which the pressure-sensitive adhesive compositions (2-I) and (2-II) adjusted by a known method are dissolved in a solvent and coated, or a hot melt coating in which the pressure-sensitive adhesive composition is heated and melted and coated. Law and the like. However, as long as the target adhesive sheet can be obtained, it will not restrict | limit especially, It can create by a well-known method.

In addition, in the above-mentioned adhesive composition (2-I) and (2-II), when shape | molding a thin film of 50 micrometers or less in thickness, it is preferable to employ | adopt the solution coating method from the ease of thickness control. On the other hand, when shape | molding the adhesive sheet of 50 micrometers or more in thickness, it is preferable to employ a hot melt coating method from environmental pollution and the ease of thick film shaping | molding.

<Lamination composition>

This adhesive sheet 2 may be a sheet which consists of a single layer, or may be a multilayer sheet obtained by laminating two or more layers.

When making this adhesive sheet 2 into a multilayer transparent double-sided adhesive material, as a laminated structure, the front and back is specifically, via the 2 type 2-layer constitution which laminated | stacked this adhesive composition 2 and another adhesive resin composition, and an intermediate resin layer. 2 type | mold 3 layer structure which arrange | positioned this adhesive composition 2 to this, 3 type | mold 3 layer structure etc. which laminate this adhesive composition 2, an intermediate resin composition, and another adhesive resin composition in this order, etc. are mentioned. Especially, it is preferable to form outermost layer with this adhesive composition 2, for example, the above-mentioned adhesive composition (2-I) and (2-II).

Moreover, you may shape | mold this adhesive composition 2 and another adhesive resin composition in sheet form on the different release film-the structural member for image display apparatuses, respectively, and may laminate | stack both adhesive surfaces, and may obtain this adhesive sheet 2, The present pressure sensitive adhesive composition 2, the intermediate resin composition, and the pressure sensitive adhesive resin composition may be coextruded in this order to obtain two types and three layers of the present pressure sensitive adhesive sheet 2, and the pressure sensitive adhesive composition 2 or the other pressure sensitive adhesive on the front and back surfaces of the intermediate resin layer. The adhesive composition 2 may be obtained by laminating the resin composition.

For example, the adhesive sheet which has the base material with which the adhesion layer formed from this adhesive composition 2 (referred to as "this adhesive layer 2") with a base material may be sufficient, and the adhesive sheet which does not have a base material may be sufficient as it. . Furthermore, the double-sided adhesive sheet which has the said adhesive layer 2 in the upper and lower sides may be sufficient, and the single-sided adhesive sheet which has the said adhesive layer 2 only in the upper and lower one side may be sufficient.

<Thickness>

It is preferable that the thickness of the largest thickness part is 250 micrometers or less from a viewpoint that the thickness of this adhesive sheet 2 does not prevent thickness reduction of an image display apparatus. In other words, the present pressure sensitive adhesive sheet 2 may be a sheet having a uniform thickness, or may be a non-uniform sheet having a partially different thickness. In the case of a sheet having a non-uniform thickness, the thickness of the thickest portion is preferably 250 μm or less. .

Moreover, it is preferable that the thickness of a largest part is 5 micrometers or more, 10 micrometers or more are more preferable, and it is still more preferable that it is 15 micrometers or more from a viewpoint that it does not interfere with adhesive force and impact absorbability with an adherend.

<Use>

Although this adhesive sheet 2 can be used also as it is, it can be used also as follows. However, the usage method of this adhesive sheet 2 is not limited.

(Adhesive Sheet Laminate 2)

This adhesive sheet 2 can be provided as the adhesive sheet laminated body 2 provided with the structure which laminates a release film on one side or both surfaces of this adhesive sheet 2, for example.

At this time, this adhesive sheet 2 may be a form which has the said soft part and a hard part in a sheet surface, for example, as shown in FIG. 1 or FIG. 2, and also shows to (A), (B) of FIG. As mentioned above, the form in which the cross section of the at least one side of an adhesive sheet has the said hard part may be sufficient. At this time, the said hard part may be sufficient as the said cross section part whole surface, and the said hard part may be a part of the said cross section part. In addition, a hard part may exist in a cross section and a surface.

As shown to Fig.4 (A), (B), if the cross-sectional part of this adhesive sheet 2 is a form with a hard part, even if it is a severe environment, for example under high temperature, high humidity, since an exposed cross-section does not become sticky, It can be stored appropriately.

(Laminated body 2 for this image display apparatus structure)

When this adhesive sheet 2 has the said soft part and the said hard part in a sheet surface, for example, the image provided with the structure formed by laminating | stacking the structural members for two image display apparatuses through this adhesive sheet 2, for example. The laminated body for display apparatus components (henceforth "the laminated body 2 for this image display apparatus structure") can be produced and provided.

The laminated body 2 for this image display apparatus structure is an image display apparatus structural member which has a light impermeable part and a light transmission part on the bonding surface, for example, and another image display structural component through the said adhesive sheet X. It can be laminated | stacked and light-irradiated to the said adhesive sheet X through the former structural member for image display apparatuses, and can produce it by partially photocuring the said adhesive sheet.

As an example of the laminated body 2 for this image display apparatus structure, besides the laminated body which consists of a structure of the protection panel / this adhesive sheet 2 / polarizing film, for example, an image display panel / this adhesive sheet 2 / touch panel, an image display panel / This adhesive sheet 2 / protection panel, image display panel / this adhesion sheet 2 / touch panel / this adhesion sheet 2 / protection panel, polarizing film / this adhesion sheet 2 / touch panel, polarizing film / this adhesion sheet 2 / touch panel / Examples of the composition, such as the present adhesive sheet 2 / protective panel, may be mentioned.

The protective panel and the image display panel may include a touch panel sensor in the protective panel or the image display panel itself.

 (This image display device 2)

The image display apparatus (henceforth "this image display apparatus 2") can also be comprised using this adhesive sheet 2 or the said laminated body for image display apparatus structures.

In other words, the image display device 2 includes at least two constitution members for facing the image display device, and at least one of the constitution members for the image display device includes an image display device having a light impermeable portion and a light transmitting portion on the bonding surface. An image display device having a configuration in which a space between the two image display device constituent members is filled with an adhesive sheet, wherein the gel fraction at the position in contact with the light transmitting portion of the adhesive sheet is 40% or more, The gel fraction at the position in contact with the light impermeable portion is less than 1%, and can be configured as an image display device.

The laminated body 2 for this image display apparatus structure, and this image display apparatus 2 WHEREIN: The part which does not permeate | transmit the light of the wavelength required for photocuring, such as the printing part of the screen periphery (it calls this "light impermeable part" in this invention) And when the component for image display device having a part of the light transmitting wavelength (referred to as "light transmitting part" in the present invention) on the bonding surface and the other member for image display device are joined together, By setting the gel fraction of the position in contact with the light-transmissive portion to less than 1% and the gel fraction of the position in contact with the light-transmissive portion to 40% or more, the stress exerted by the light-impermeable portion can be alleviated. The resulting distortion can be reduced, and the adherends can be firmly adhered to each other with high cohesion.

Moreover, it is especially preferable that the gel fraction of the position which contact | connects a light impermeable part is less than 1%, and especially it is more preferable that it is less than 0.8%.

On the other hand, it is especially preferable that the gel fraction of the position which contact | connects a light transmission part is 40% or more, and especially it is more preferable that it is 45% or more.

An example of the preferable manufacturing method of this image display apparatus 2 is demonstrated.

First, the said adhesive sheet X is heated and hot-melted, and the structural member 1 for image display apparatuses which have the printing part 1, and the structural member 3 for image display apparatuses are laminated | stacked through the said adhesive sheet X. In this step, since the adhesive sheet X is moderately flexible, it can fully follow a step | step while maintaining storage stability.

Next, light, such as an ultraviolet-ray, is irradiated from the outer side of the structural member 1 for image display apparatuses. Then, since the printing unit 1 shields the light, the light does not reach the portion in contact with the printing unit 1, or the reaching light is significantly limited, whereas the light transmitting unit without the printing unit 1 ( Light reaches the part which contact | connects 3) enough, the crosslinking reaction of this part advances, it can photocure, and the outstanding peeling resistance and foaming resistance can be implement | achieved.

Examples of the constituent members for the two image display apparatuses include an image display apparatus such as a personal computer, a mobile terminal (PDA), a game machine, a television (TV), a car navigation system, a touch panel, a pen tablet, and the like. The structural member of this is mentioned. More specifically, the laminated body which consists of any one of the group which consists of a touch panel, an image display panel, a surface protection panel, and a polarizing film, or a combination of 2 or more types is mentioned, for example.

(Adhesive sheet roll)

As shown in FIG. 5, this adhesive sheet 2 may be a form wound by roll shape. For example, after winding the adhesive sheet X in roll shape, light may be irradiated and photocured only to the cross section, and this adhesive sheet 2 which photocured only the cross section may be wound and produced in roll shape. In any case, if the cross section of the pressure-sensitive adhesive sheet in the form of a roll is a photocurable portion, the exposed roll cross section may not be sticky even in a harsh environment such as, for example, under high temperature and high humidity, and thus can be suitably stored.

<This adhesive sheet 3>

The double-sided adhesive sheet (henceforth "this adhesive sheet 3") which concerns on another example of embodiment of this invention is 100 mass parts of (meth) acrylic-type copolymers (3-A), and a crosslinking agent (3-B) 0.5- As a double-sided adhesive sheet which consists of an adhesive resin composition (henceforth "this adhesive resin composition 3") containing 20 mass parts and 0.1-5 mass parts of photoinitiators (3-C), it is optical crosslinking with respect to tensile elasticity modulus. It is an adhesive sheet characterized by the ratio (X ₁ / X ₂ ) of the tensile modulus of elasticity (X ₁ ) before and the tensile modulus of elasticity (X ₂ ) after optical crosslinking being 3 or more.

In the field of an image display device mainly on a mobile phone or a mobile terminal, in addition to thinning and high definition, design diversification is progressing, and new problems have arisen accordingly. For example, it is common to print a black concealment in a frame shape on the periphery of the surface protection panel. Therefore, the adhesive sheet for pasting the structural member provided with such a printing part requires the printing step track | trackability which can be filled to a corner following a printing step | step. At this time, when there was no adhesiveness (tackiness) before light crosslinking, the bonding operation was not easy.

Therefore, the present invention is an adhesive sheet capable of photocrosslinking, which has adhesiveness even before optical crosslinking, and at the time of bonding, the adhesive material does not flow excessively and the adhesive resin composition is pushed out or crushed. It is to provide this adhesive sheet 3 which can be obtained.

The present adhesive sheet 3 has a feature that the difference in tensile modulus (X ₁ , X ₂ ) before and after optical crosslinking is remarkably large, and it has adhesiveness even before photocrosslinking. It is not pushed out or crushed, and after the light crosslinking, sufficient hardness can be obtained.

<This adhesive resin composition 3>

This adhesive resin composition 3 is a resin composition containing a (meth) acrylic-type copolymer (3-A), a crosslinking agent (3-B), and a photoinitiator (3-C) as mentioned above.

<(Meth) acrylic copolymer (3-A)>

It is preferable that the (meth) acrylic copolymer (3-A) as the base polymer is a graft copolymer (3-A1) having a macromonomer as a branch component.

Here, a "base polymer" is the meaning of resin which comprises the main component of this adhesive resin composition 3. Although it does not prescribe the specific content of a base polymer, As a reference | standard, 50 mass% or more of resin contained in this adhesive resin composition 3, especially 80 mass% or more, especially 90 mass% or more (including 100 mass%) as a reference | standard It is the resin which occupies. In addition, when there are two or more types of base polymers, those total amounts correspond to the said content.

(Stem component)

It is preferable that the stem component of the said graft copolymer (3-A1) is comprised from the copolymer component containing the repeating unit derived from (meth) acrylic acid ester.

It is preferable that the glass transition temperature of the copolymer which comprises the stem component of the said graft copolymer (3-A1) is -70-0 degreeC.

At this time, the glass transition temperature of the copolymer component which comprises a stem component refers to the glass transition temperature of the polymer obtained by copolymerizing only the monomer component which comprises the stem component of a graft copolymer (3-A1). Specifically, the value calculated by Fox's calculation formula from the glass transition temperature and composition ratio of the polymer obtained from the homopolymer of each component of the said copolymer is meant.

In addition, the calculation formula of Fox is a calculated value calculated | required by the following formula | equation, and can be calculated | required using the value described in a polymer handbook (Polymer HandBook, J. Brandrup, Interscience, 1989).

1 / (273 + Tg) = Σ (Wi / (273 + Tgi))

[Wherein, Wi represents the weight fraction of the monomer i, Tgi represents the Tg (° C.) of the homopolymer of the monomer i.]

The glass transition temperature of the copolymer component which comprises the stem component of the said graft copolymer (3-A1) is the softness of this adhesive resin composition 3 in room temperature, or the wettability of this adhesive resin composition 3 with respect to a to-be-adhered body, ie In order to affect adhesiveness, in order for this adhesive resin composition 3 to obtain moderate adhesiveness (tackiness) in room temperature state, it is preferable that the said glass transition temperature is -70 degreeC-0 degreeC, and -65 degreeC or more, especially- It is especially preferable that it is 5 degrees C or less, especially -60 degrees C or more or -10 degrees C or less.

However, even if the glass transition temperature of the said copolymer component was the same temperature, viscoelasticity can be adjusted by adjusting molecular weight. For example, it can be made softer by making the molecular weight of a copolymer component small.

As a (meth) acrylic acid ester monomer which the stem component of the said graft copolymer (3-A1) contains, for example, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, n-butyl acrylate, Ethyl acrylate, methyl methacrylate, methyl acrylate, etc. are mentioned. In these, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, acrylic acid, methacrylic acid, glycidyl acrylate, acrylamide having a hydrophilic group or an organic functional group, etc. , N, N-dimethylacrylamide, acrylonitrile, methacrylonitrile and the like can also be used.

Moreover, various vinyl monomers, such as vinyl acetate copolymerizable with the said acryl monomer and methacryl monomer, alkyl vinyl ether, and hydroxyalkyl vinyl ether, can also be used suitably.

Moreover, it is preferable that the stem component of a graft copolymer (3-A1) contains a hydrophobic (meth) acrylate monomer and a hydrophilic (meth) acrylate monomer as a structural unit.

When the stem component of the graft copolymer (3-A1) is composed of only hydrophobic monomers, the tendency to wet heat whitening is recognized. Therefore, it is preferable to introduce a hydrophilic monomer into the stem component to prevent wet heat whitening.

Specifically, as the stem component of the graft copolymer (3-A1), a hydrophobic (meth) acrylate monomer, a hydrophilic (meth) acrylate monomer, and a polymerizable functional group at the terminal of the macromonomer are randomly copolymerized. The copolymer component which consists of is mentioned.

Here, as said hydrophobic (meth) acrylate monomer, the alkyl ester which does not have a polar group (except methyl acrylate) is preferable, For example, n-butyl (meth) acrylate and n-hexyl ( Meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, n-decyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-methylhexyl (meth) acrylic Isooctyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, methyl methacrylate And vinyl acetate .

As said hydrophilic (meth) acrylate monomer, methyl acrylate and ester which has a polar group are preferable, For example, methyl acrylate, (meth) acrylic acid, tetrahydrofurfuryl (meth) acrylate, 2-hydroxy Ethyl (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxy Propyl hexahydrophthalic acid, N, N-dimethyl acrylamide, hydroxyethyl acrylamide and the like.

(Branch ingredient: macromonomer)

As a branch component of a graft copolymer (3-A1), it is preferable to introduce a macromonomer and to contain the repeating unit derived from a macromonomer.

A macromonomer is a high molecular monomer which has a terminally polymerizable functional group and a high molecular weight skeleton component.

It is preferable that the glass transition temperature (Tg) of a macromonomer is higher than the glass transition temperature of the copolymer component which comprises the said graft copolymer (3-A1).

Specifically, since the glass transition temperature (Tg) of the macromonomer affects the heat melting temperature (hotmelt temperature) of the present adhesive resin composition 3, the glass transition temperature (Tg) of the macromonomer is 30 ° C to 120 ° C. It is preferable that it is 40 degreeC or more or 110 degrees C or less, especially, 50 degrees C or more or 100 degrees C or less especially.

If it is such a glass transition temperature (Tg), by adjusting molecular weight, while maintaining excellent workability and storage stability, it can adjust so that it may melt at 80 degreeC vicinity.

The glass transition temperature of a macromonomer refers to the glass transition temperature of the said macromonomer itself, and can measure it with a differential scanning calorimeter (DSC). (The temperature rising rate: 5 degree-C / min, Tg is measured from the inflection point of a baseline shift)

In addition, in the room temperature state, in order to be able to maintain the state which physically bridge | crosslinked as the adhesive resin composition 3 which pulled the branch components mutually, and in addition, in order that the said physical crosslinking may be loosened and fluidity | liquidity is obtained by heating to moderate temperature. It is also preferable to adjust the molecular weight and content of the macromonomer.

From such a viewpoint, it is preferable to contain a macromonomer in the ratio of 5 mass%-30 mass% in a graft copolymer (3-A1), Especially, 6 mass% or more or 25 mass% or less, 8 mass% is especially It is preferable that it is more than 20 mass%.

Moreover, it is preferable that the number average molecular weights of a macromonomer are 500 or more and less than 8000, and especially, it is preferable that they are 800 or more or less than 7500, especially 1000 or more or less than 7000.

As a macromonomer, what is generally produced (for example, the macromonomer made from the same synthetic synthetic company etc.) can be used suitably.

It is preferable that the high molecular weight skeleton component of a macromonomer is comprised from an acryl-type polymer or a vinyl type polymer.

As the high molecular weight skeleton component of the macromonomer, for example, a copolymer of polystyrene, styrene and acrylonitrile, poly (t-butylstyrene), poly (α-methylstyrene), polyvinyltoluene, polymethylmethacrylate, etc. Can be mentioned.

As a terminal polymerizable functional group of the said macromonomer, a methacryloyl group, acryloyl group, a vinyl group, etc. are mentioned, for example.

 (Physical Properties of (meth) acrylic Copolymer (3-A))

It is preferable that the complex viscosity of said (meth) acrylic-type copolymer (3-A) in temperature 130 degreeC and a frequency of 0.02 Hz is 100-800 Pa.s, 150-700 Pa.s is more preferable, 170-600 Pa. S is more preferred.

Since the complex viscosity at the temperature of 130 degreeC of the said (meth) acrylic-type copolymer (3-A) affects the fluidity | liquidity of the adhesive resin composition at the time of hot-melting the said transparent double-sided adhesive material, such a complex viscosity is 100 If it is -800 Pa.s, it can be made excellent hot melt aptitude.

In order to adjust the complex viscosity of the said (meth) acrylic-type copolymer (3-A) to the said range, the glass transition temperature of the copolymer component which comprises the stem component of a graft copolymer (3-A1) is adjusted, for example. It can be mentioned. Preferably -70 degreeC-0 degreeC, especially -65 degreeC or more or -5 degreeC or less, Especially adjusting to -60 degreeC or more or -10 degrees C or less, while adjusting the molecular weight of the said copolymer component, and adjusting a viscoelasticity The method of adjusting is mentioned. However, it is not limited to this method.

<Crosslinking agent (3-B)>

As a crosslinking agent (3-B), the crosslinking agent which has two or more crosslinkable groups, such as an epoxy group, an isocyanate group, an oxetane group, a silanol group, and a (meth) acryloyl group, can be selected suitably, for example. Especially, from the point of reactivity and the intensity | strength of the hardened | cured material obtained, it has a polyfunctional (meth) acrylate which has two or more (meth) acryloyl groups, three or more especially, an epoxy group, an isocyanate group, and a silanol group (meth ) Acrylates are preferred.

As such a polyfunctional (meth) acrylate, for example, 1,4-butanediol di (meth) acrylate, glycerin di (meth) acrylate, glycerin glycidyl ether di (meth) acrylate, 1,6- Hexanedioldi (meth) acrylate, 1,9-nonanedioldi (meth) acrylate, tricyclodecanedimethanoldi (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, bisphenol A polyprop Foxydi (meth) acrylate, bisphenol F polyethoxydi (meth) acrylate, ethylene glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, ε-caprolactone modified tris (2- Hydroxyethyl) isocyanurate tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, Taerythritol tetra (meth) acrylate, propoxylated pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyethylene glycol di (meth) acrylate , Tris (acryloxyethyl) isocyanurate, dipentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, hydroxy pivalic acid neopentyl glycol di (Meth) acrylate, di (meth) acrylate of ε-caprolactone adduct of hydroxypivalic acid neopentyl glycol, trimethylolpropane tri (meth) acrylate, trimethylolpropanepolyethoxytri (meth) acrylate, In addition to ultraviolet-curable polyfunctional monomers such as ditrimethylolpropane tetra (meth) acrylate, Polyfunctional acrylic oligomers, such as a steer (meth) acrylate, an epoxy (meth) acrylate, a urethane (meth) acrylate, and a polyether (meth) acrylate, an isocyanate (meth) acrylate, 1,1- (bis (Meth) acryloyloxymethyl) ethyl isocyanate, 2- (2- (meth) acryloyloxyethyloxy) ethyl isocyanate, glycidyl (meth) acrylate, hydroxyethyl acrylate glycidyl ether, hydrate Hydroxypropyl (meth) acrylate glycidyl ether and hydroxybutyl (meth) acrylate glycidyl ether.

Among the above-mentioned, the polyfunctional monomer or oligomer containing polar functional groups, such as a hydroxyl group, is preferable from a viewpoint of improving the adhesiveness to a to-be-adhered body, and the effect of suppressing wet heat whitening.

Especially, it is preferable to use the polyfunctional (meth) acrylic acid ester which has a hydroxyl group.

Therefore, from the viewpoint of preventing wet heat whitening, as the stem component of the graft copolymer (3-A1), it is preferable to contain a hydrophobic acrylate monomer and a hydrophilic acrylate monomer, and furthermore, a crosslinking agent (3 As -B), it is preferable to use the polyfunctional (meth) acrylic acid ester which has a hydroxyl group.

It is preferable to contain content of a crosslinking agent (3-B) in the ratio of 0.5-20 mass parts with respect to 100 mass parts of (meth) acrylic-type copolymers (3-A), and 1 mass part or more or 15 mass parts or less especially Especially, it is more preferable that it is the ratio of 2 mass parts or more or 10 mass parts or less.

By containing a crosslinking agent (3-B) in the said range, the shape stability of this adhesive sheet 3 in an uncrosslinked state, and the foaming reliability in the adhesive material after crosslinking can be made compatible. However, you may exceed this range by balance with another element.

<Photopolymerization Initiator (3-C)>

A photoinitiator (3-C) functions as a reaction start adjuvant in the crosslinking reaction of the above-mentioned crosslinking agent (3-B).

A photoinitiator can use a well-known thing suitably now. Especially, the photoinitiator sensitive to the ultraviolet-ray of wavelength 380 nm or less is preferable from a viewpoint of the controllability of a crosslinking reaction.

On the other hand, the photoinitiator which responds to the light of longer wavelength than wavelength 380 nm is preferable at the point which the sensitive light is easy to reach to the core part of this adhesive sheet 3.

The photopolymerization initiator is largely classified into two by radical generating mechanisms, and a cleavage type photopolymerization initiator capable of generating a radical by cleaving a single bond of the photopolymerizable initiator itself, a photoexcited initiator, and a hydrogen donor in the system are excited complexes. And a hydrogen drawing photopolymerization initiator capable of transferring the hydrogen of the hydrogen donor.

Among these, the cleavage type photopolymerization initiator decomposes when generating radicals by light irradiation to form another compound, and once excited, it does not have a function as a reaction initiator. For this reason, since it does not remain as active species in the adhesive material after completion | finish of crosslinking reaction, since it is unlikely to cause unexpected light deterioration etc. in an adhesive material, it is preferable.

On the other hand, since the hydrogen-drawn photoinitiator does not generate decomposition products such as cleavage photoinitiators during radical generation reaction by active energy ray irradiation such as ultraviolet rays, it is difficult to become a volatile component after completion of the reaction. It is useful in that damage can be reduced.

As said cleavage type photoinitiator, 2, 2- dimethoxy- 1, 2- diphenyl ethanol 1-one, 1-hydroxy cyclohexyl phenyl ketone, 2-hydroxy-2- methyl-1-phenyl -Propan-1-one, 1- (4- (2-hydroxyethoxy) phenyl) -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- [4- {4- (2-hydroxy-2-methyl-propionyl) benzyl} phenyl] -2-methyl-propane-1-one, oligo (2-hydroxy-2-methyl-1- (4- (1- Methylvinyl) phenyl) propanone), methyl phenylglyoxylate, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2-methyl-1- [4- ( Methylthio) phenyl] -2-morpholinopropane-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl]- 1-butanone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, derivatives thereof, and the like.

As said hydrogen draw type photoinitiator, it is benzophenone, 4-methyl- benzophenone, 2,4,6-trimethyl benzophenone, 4-phenylbenzo phenone, 3,3'- dimethyl- 4-methoxy benzophenone, for example. , 4- (meth) acryloyloxybenzophenone, methyl 2-benzoylbenzoate, methyl benzoyl formate, bis (2-phenyl-2-oxoacetic acid) oxybisethylene, 4- (1,3-acryloyl-1 , 4,7,10,13-pentaoxotridecyl) benzophenone, thioxanthone, 2-chlorothioxanthone, 3-methylthioxanthone, 2,4-dimethylthioxanthone, 2-methylanthraquinone, 2-ethyl anthraquinone, 2-tert- butyl anthraquinone, 2-aminoanthraquinone, its derivatives, etc. are mentioned.

However, it is not limited to the above-mentioned substance as a photoinitiator. Any one of the above-mentioned cleavage type photopolymerization initiator and a hydrogen extraction type photopolymerization initiator may be used, or may be used in combination of 2 or more type.

It is preferable to contain content of a photoinitiator (3-C) in the ratio of 0.1-5 mass parts with respect to 100 mass parts of (meth) acrylic-type copolymers (3-A), Especially 0.5 mass part or more or 3 mass parts Hereinafter, it is more preferable to contain especially in 1 mass part or more ratio.

By making content of a photoinitiator (3-C) into the said range, suitable reaction sensitivity with respect to an active energy ray can be obtained.

<Other ingredients>

This adhesive resin composition 3 may contain the well-known component mix | blended with a normal adhesive resin composition as a component of that excepting the above. For example, if necessary, various additives such as tackifier resins, antioxidants, light stabilizers, metal deactivators, anti-aging agents, moisture absorbents, polymerization inhibitors, ultraviolet absorbers, rust inhibitors, silane coupling agents, inorganic particles, etc. may be appropriately contained. It is possible to let.

Moreover, you may contain suitably a reaction catalyst (a tertiary amine compound, a quaternary ammonium compound, a lauryl acid tin compound etc.) as needed.

<Features of this adhesive sheet 3>

This adhesive sheet 3 can hold | maintain a sheet shape in a normal state, and it can be set as the adhesive sheet which has the hot melt property which melts or flows when it heats in an uncrosslinked state, and has photocurability which can be photocurable. .

When the sheet shape can be held in the normal state, the handling is easier than the liquid adhesive, and the work of filling the liquid can be omitted, which is particularly excellent in productivity. At this time, in the normal state, i.e., around room temperature, if it has a moderate adhesiveness, that is, a property of adhering to the adherend in a short time with light force (called "tackiness"), it is easy to perform positioning when sticking. From the point which is excellent in workability, it is preferable to have tackiness in a normal state, ie, near room temperature, and it is more preferable if it has tackiness also in the comparatively low temperature area | region of -5 degreeC-20 degreeC. Such tackiness can be obtained by using the said graft copolymer (3-A1) as a (meth) acrylic-type copolymer (3-A).

Moreover, if it has hot meltability which melts or flows when it heats, by heating and softening or fluidizing, since an adhesive can be filled in uneven | corrugated parts, such as a printing step, it can be filled, without foaming.

Furthermore, if it has photocurability, it can be reliably adhere | attached by finally photocuring.

As mentioned above, in order to produce the adhesive sheet which can hold | maintain a sheet shape in a normal state, and melts and flows when it heats in an uncrosslinked state, and can be photocurable, for example, What is necessary is just to produce the single-layered adhesive sheet from the said adhesive resin composition 3 as it is an adhesive sheet. On the other hand, when it is set as a multilayer adhesive sheet, the front and back is laminated | stacked via the 2 type | two layer 2-layer structure which laminated | stacked the adhesion layer which consists of this adhesive resin composition 3, and the adhesion layer which consists of another adhesive resin composition, for example. The pressure-sensitive adhesive layer composed of two or three-layered constitution in which the pressure-sensitive adhesive layer made of the present pressure-sensitive adhesive resin composition 3 is disposed, the pressure-sensitive adhesive layer made of the present pressure-sensitive adhesive resin composition 3, the intermediate layer made of the intermediate resin composition, and the other pressure-sensitive adhesive resin composition Three types of three layer structure etc. which are laminated | stacked in order are mentioned.

However, the adhesive resin composition for forming this adhesive sheet 3 is not limited to this adhesive resin composition 3.

(Gel fraction)

It is especially preferable that this adhesive sheet 3 is 5% or less, especially 4% or less, especially 2% or less of the gel fraction (a) before photocuring from a viewpoint which can express hot melt property in the state before photocuring.

Moreover, it is preferable that the gel fraction (b) after photocuring is 50% or more from the viewpoint of this cohesive sheet 3 being able to obtain a high cohesion force after photocuring, and obtaining foaming reliability in a wet heat environment, and especially 60% or more. Or 90% or less, especially 65% or more or 80% or less.

In order to adjust the gel fraction (a) before photocuring and the gel fraction (b) after photocuring as mentioned above, it is a (meth) acrylic-type copolymer (3-A), provided with a macromonomer as a branch component, for example. What is necessary is just to adjust the composition ratio of a crosslinking agent and a photoinitiator, or to adjust the temperature and the amount of light irradiation at the time of processing, using a graft copolymer (A1). However, it is not limited to such a method.

 Tensile Modulus

With respect to the present adhesive sheet 3, when the ratio (X ₁ / X ₂ ) between the tensile modulus (X ₁ ) before the photocrosslinking and the tensile modulus (X ₂ ) after the photocrosslinking is 3 or more, good step absorption and foaming reliability are achieved. Obtained.

From this point of view, the ratio (X ₁ / X ₂ ) of the tensile modulus (X ₁ ) before the optical crosslinking and the tensile modulus (X ₂ ) after the photocrosslinking is preferably 3 or more, and particularly 5 or 30 or less, and particularly 10 It is further more preferable that it is more or less than 27.

Tensile modulus (X ₁₎ prior to photo-crosslinking is preferably not more than 0.01MPa 0.2MPa or less, and among them it is more preferable than 0.05MPa 0.1MPa or less.

On the other hand, the tensile modulus (X ₂ ) after photocrosslinking is preferably 0.8 MPa or more and 2.0 MPa or less, and more preferably 1.0 MPa or more or 1.8 MPa or less.

Tensile Maximum Stress (Y)

With respect to the adhesive sheet 3, the ratio of the tensile maximum stress after tensile maximum stress (Y ₁₎ and photo-crosslinking prior to photo-crosslinking _{(Y 2) (Y 1 /} Y 2) is a 5 or more 20 or less, in a preferred step-absorbent or Foaming reliability is obtained.

From this point of view, the adhesive sheet 3, and the ratio (Y ₁ / Y ₂₎ of the optical cross-tensile maximum stress (Y ₁₎ and tensile maximum stress after a photo-crosslinking (Y ₂₎ prior to or less than 520 is preferred, the It is more preferable that it is 8 or more or 15 or less among these.

Tensile maximum stress before photo-crosslinking (Y ₁₎ is preferably not less than 5N and 0.5N, particularly not more than 0.8N, or less than or equal to 2N is particularly preferable.

On the other hand, the tensile maximum stress (Y ₂ ) after photocrosslinking is preferably 7N or more and 15N or less, and particularly preferably 9N or more or 12N or less.

(Tensile fracture stress (Z))

With respect to the adhesive sheet 3, a ratio (Z ₁ / Z ₂₎ of the tensile fracture before photocrosslinking stress (Z ₁₎ and the optical tensile rupture stress (Z ₂₎ after crosslinking is 10 or more 50 or less, good step absorbent or within the foam Reliability is obtained.

From this viewpoint, it is preferable that the ratio (Z ₁ / Z ₂ ) of the tensile breaking stress Z ₁ before the photocrosslinking and the tensile breaking stress Z ₂ after the photocrosslinking is 10 or more and 50 or less. Especially, it is especially preferable that they are 15 or more or 40 or less.

The tensile stress at rupture (Z ₁₎ prior to photo-crosslinking is preferably not more than 2N 0.1N or less, and among them it is more than 0.2N, or 0.6N or less is particularly preferred.

On the other hand, a tensile stress at rupture (Z ₂₎ after photo-crosslinking is preferably at least 7N and 16N or less, particularly to not more than 9N or 12N or more is particularly preferred.

In this adhesive sheet 3, in order to adjust tensile elasticity modulus, tensile maximum stress, and tensile fracture stress in the said range, it is a (meth) acrylic-type copolymer (3-A), for example, provided with a macromonomer as a branch component. What is necessary is just to adjust the kind and number of copies of the said macromonomer, using a graft copolymer (3-A1). However, it is not limited to this method.

As the (meth) acrylic copolymer (3-A), when the graft copolymer (3-A1) having a macromonomer as a branch component is used, the sheet shape can be retained even in a normal state, and the fluidity is exhibited by heating. By doing this, the step followability can be satisfied, and the curing reaction proceeds by ultraviolet crosslinking to obtain excellent adhesion reliability.

<Lamination composition>

This adhesive sheet 3 may be a sheet which consists of a single layer, or may be a multilayer sheet obtained by laminating two or more layers.

When making this adhesive sheet 3 a multilayer transparent double-sided adhesive material, since it is preferable that outermost layer has both uneven harvestability and foaming reliability similarly to the case of the said single layer, said present adhesive resin composition 3 is It is preferable to shape | mold using.

On the other hand, since the intermediate layer does not contribute to adhesion with the constituent member for an image display device, the intermediate layer has a light transmittance such that it does not impair transparency and does not impair the secondary curing reaction of the outermost layer. It is preferable to have the property to improve handling property.

The kind of base polymer which forms an intermediate | middle layer will not be specifically limited if it is a transparent resin. The base polymer which forms an intermediate | middle layer may be resin same as the base polymer of an outermost layer, or may be different resin. Especially, it is preferable to use the same acrylic resin as the base polymer of an outermost layer from a viewpoint of ensuring transparency, the ease of manufacture, and also the refraction of the light in a laminated interface.

The intermediate layer and the other resin layer may or may not have active energy ray curability. For example, you may form so that it may harden | cure by ultraviolet bridge | crosslinking, and you may form so that it may harden | cure by heat. Moreover, you may form especially in order not to postcure. However, in consideration of the adhesiveness with the outermost layer, it is preferable to form so as to be post-cured, particularly preferably formed so as to crosslink ultraviolet rays.

In that case, when content of a crosslinking initiator increases, light transmittance will fall, It is preferable to contain an ultraviolet crosslinking agent in content rate lower than the content rate in the outer layer of the crosslinking initiator in an intermediate | middle layer.

When making this adhesive sheet 3 into a multilayer transparent double-sided adhesive material, as a laminated structure, specifically, this adhesive resin composition 3 and the other two-layered constitution which laminated | stacked another adhesive resin composition, and the intermediate resin layer through. Two kind three layer structure which arrange | positioned this adhesive resin composition 3 on the front and back, Three kind three layer structure formed by laminating | stacking this adhesive resin composition 3, an intermediate resin composition, and another adhesive resin composition in this order, etc. are mentioned. .

Moreover, you may shape | mold this adhesive resin composition 3 and another adhesive resin composition in sheet form on the different release film thru | or the structural member for image display apparatuses, respectively, laminate | stack both adhesive surfaces, and may obtain this adhesive sheet 3, and The present pressure sensitive adhesive resin composition 3, the intermediate resin composition, and the pressure sensitive adhesive resin composition may be coextruded in this order to obtain the present pressure sensitive adhesive sheet 3 of two kinds and three layers, and the pressure sensitive adhesive resin composition seen on the front and back surfaces of the intermediate resin layer. You may laminate | stack 3 or another adhesive resin composition so that this adhesive sheet 3 may be obtained.

For example, the adhesive sheet with a base material with the structure which forms the said adhesive layer 3 in a base material may be sufficient, and the adhesive sheet without a base material may be sufficient as it. Furthermore, the double-sided adhesive sheet which has the adhesion layer 3 which looked at both upper and lower sides may be sufficient, and the single-sided adhesive sheet which has this adhesion layer 3 seen only in the upper and lower single side | surface side may be sufficient.

<Thickness>

The thickness, that is, the total thickness of the present adhesive sheet 3 is preferably 50 µm to 1 mm, and more preferably 75 µm or more or 500 µm or less, from the viewpoint of not disturbing the thinning of the image display device and the viewpoint of step absorbency. Do.

If the total thickness of this adhesive sheet 3 is 50 micrometers or more, it is possible to track against the unevenness | corrugation, such as a high printing step, and if it is 1 mm or less, it can respond to the request of thickness reduction.

In addition, from the viewpoint that the printing height of the concealed layer around the periphery in the conventional image display device is higher, specifically covering a step of about 80 μm, the total thickness of the present adhesive sheet 3 is more preferably 75 μm or more, It is more preferable that it is especially 100 micrometers or more. On the other hand, it is preferable that it is 500 micrometers or less from a viewpoint which responds to the request of thinning, and it is more preferable that it is 350 micrometers or less especially.

Moreover, it is preferable that the thickness of a largest part is 5 micrometers or more, 10 micrometers or more are more preferable, and it is still more preferable that it is 15 micrometers or more from a viewpoint that it does not interfere with adhesive force and impact absorbability with an adherend.

When it is set as a multilayer structure, it is preferable that the ratio of the thickness of each outermost layer and the thickness of an intermediate | middle layer is 1: 1-1: 20, and especially it is more preferable that it is 1: 2-1: 10.

If the thickness of an intermediate | middle layer is the said range, the contribution of the thickness of the adhesive material layer in a laminated body does not become large too much, it is too flexible, and workability with respect to cutting and a process does not fall, and it is preferable.

If the outermost layer is within the above range, the harvestability to the uneven or curved surface may not be inferior, and adhesion and wettability to the adherend can be maintained, which is preferable.

Moreover, it is preferable that the thickness of the largest thickness part of this adhesive sheet 3 is 250 micrometers or less. In other words, the present pressure-sensitive adhesive sheet 3 may be a sheet having a uniform thickness, or may be a non-uniform sheet having a partially different thickness. In the case of a sheet having a non-uniform thickness, the thickness of the thickest portion is preferably 250 μm or less. .

<Use>

Although this adhesive sheet 3 can be used also as it is, it can be used also as follows. However, the usage method of this adhesive sheet 3 is not limited.

(Adhesive sheet laminate)

This adhesive sheet 3 can be provided as an adhesive sheet laminated body provided with the structure which laminates a release film on one surface or both surfaces of this adhesive sheet 3, for example.

 (Laminated body 3 for this image display apparatus structure)

As an example of the use of this adhesive sheet 3, the laminated body for image display apparatus structures provided with the structure formed by laminating | stacking between the structural members for two image display apparatuses through this adhesive sheet 3 (henceforth "this image display apparatus structure. For the laminate 3).

The laminated body 3 for this image display apparatus structure is comprised, for example with two image display apparatus structural members facing at least, and the at least one structural member for image display apparatuses is a light impermeable part and a light transmissive part to a bonding surface. A laminated body for an image display device configuration having a structure, comprising: a laminate for an image display device configuration having a configuration in which the two member members for image display devices are filled with the present adhesive sheet 3, the configuration for the image display device. The laminated body for image display apparatus structures provided with the structure which irradiates light to the said adhesive sheet through a member and partially photocures the said adhesive sheet is mentioned.

Under the present circumstances, the gel fraction of the position which contact | connects the said light transmitting part of the said adhesive sheet can be 50% or more, and the gel fraction of the position which contact | connects the said light impermeable part can be made less than 5%.

Here, as said structural member for image display apparatus, the laminated body which consists of a combination of any one or two or more types from the group which consists of a touch panel, an image display panel, a surface protection panel, and a polarizing film is mentioned.

As an example of the laminated body 3 for this image display apparatus structure, besides the laminated body which consists of a structure of the protection panel / this adhesive sheet 3 / polarizing film, for example, an image display panel / this adhesive sheet 3 / touch panel, an image display panel / This adhesive sheet 3 / protection panel, image display panel / this adhesive sheet 3 / touch panel / this adhesive sheet 3 / protection panel, polarizing film / this adhesive sheet 3 / touch panel, polarizing film / this adhesive sheet 3 / touch panel / Examples of the structure of the present adhesive sheet 3 / protective panel may be mentioned.

The protective panel and the image display panel may include a touch panel sensor in the protective panel or the image display panel itself.

The laminated body 3 for this image display apparatus structure can be manufactured through the process of following (1)-(3), for example.

However, since the manufacturing method of the laminated body 3 for this image display apparatus structure should have a process of at least following (1)-(3), adding another process or inserting another process between each process is required. It is possible.

(1) A pressure-sensitive adhesive resin composition containing a (meth) acrylic copolymer (3-A), a crosslinking agent (B), and a photopolymerization initiator (C) is prepared, and a single or multi-layered sheet is formed using the pressure-sensitive adhesive resin composition. Molding to prepare the present pressure-sensitive adhesive sheet 3.

(2) The process of sticking and laminating | stacking the two structural member for image display apparatus through this adhesive sheet 3.

(3) The process of irradiating active adhesive ray to this adhesive sheet 3 from the outer side of the at least one structural member for image display apparatuses, bridge | crosslinking this adhesive sheet 3, and bonding two structural member for image display apparatuses.

(Step (1))

In the step (1), the present pressure sensitive adhesive resin composition 3 is prepared by a known method, and the present pressure sensitive adhesive sheet 3 is produced by molding into a single or multi-layer uncrosslinked sheet shape provided with a pressure sensitive adhesive layer made of the pressure sensitive adhesive resin composition. .

The method of shape | molding this adhesive resin composition 3 in a sheet form can employ | adopt a method currently well known arbitrarily.

Under the present circumstances, you may make this adhesive resin composition 3 shape | mold in single-layer or multilayer sheet form on a release film, and produce the single-layer or multilayer transparent double-sided adhesive material provided with an adhesion layer.

Moreover, this adhesive resin composition 3 is shape | molded in the form of a single | mono layer or multilayer on the structural member for image display apparatuses, and the single-layer or multilayer transparent double-sided adhesive material provided with the adhesion layer on the said component for image display apparatuses. You may make it.

(Step (2))

In the step (2), two structural member for image display apparatus can be stuck together and laminated | stacked through the said adhesive sheet 3.

At this time, when the graft copolymer (A1) is used as the base polymer of the present adhesive sheet 3, in the normal state, that is, at room temperature, the macromonomers aggregate to form a physical crosslinked structure, which is superior to the present adhesive sheet 3 Storage stability and cutting processability can be provided.

Furthermore, when the (meth) acrylic copolymer (3-A) has a complex viscosity at a temperature of 130 ° C. and a frequency of 0.02 Hz of 100 to 800 Pa · s, excellent workability is achieved when used as a hot melt sheet during bonding. can do.

In this manner, in the step (2), two component members for image display devices can be stuck together and laminated via the present adhesive sheet 3. By doing in this way, since the adhesiveness which can be easily stuck only by pressing this adhesive sheet 3 to a to-be-adhered body can be obtained, the positioning which sticks an adhesive material is easy, and it is very convenient in operation | work.

Moreover, since this adhesive sheet 3 is excellent in shape retention property and can be processed into arbitrary shapes beforehand, since this adhesive sheet 3 shape | molded this adhesive sheet 3 shape | molded on the release film, of the structural member for image display apparatuses laminated | stacked, It can also be cut to fit the dimensions.

As for the cutting method at this time, punching by a thomson blade, cutting by a super cutter, or a laser is common, and it is more preferable to leave half the release film of one of the front and back in a frame shape so that peeling off of a release film is easy.

Also in process (2), this adhesive sheet 3, ie, a transparent double-sided adhesive material, is in an uncrosslinked state.

(Step (3))

In the step (3), at least one of the constituent members for image display apparatuses is irradiated with the pressure-sensitive adhesive layer of the pressure sensitive adhesive sheet 3 seen from the outside of the constituent members for image display apparatuses, and the tackifier layers are crosslinked to form two constituent members for image display apparatuses. The laminate 3 for the present image display device configuration can be manufactured by adhering.

Since this adhesive sheet 3 contains a crosslinking agent (B) and a photoinitiator (C), it can irradiate the said adhesion layer of this adhesive sheet 3 with an active energy ray, and can crosslink and harden the said adhesion layer, Component members for image display apparatus can be reliably attached.

At this time, as an active energy ray, what is necessary is just to irradiate the energy ray which sensitizes a polymerization initiator, such as a heat ray, an X ray, an electron beam, an ultraviolet-ray, a visible ray. Especially, it is preferable to irradiate an ultraviolet-ray, especially the ultraviolet-ray with a wavelength of 380 nm or less from a viewpoint of the damage suppression to the structural member for image display apparatuses, and the ease of reaction control.

There is no restriction | limiting in particular about ultraviolet irradiation conditions. For example, it is preferable to irradiate so that the accumulated light quantity of the ultraviolet-ray which reaches | attains an adhesive material may be 500-5000mJ / cm <2> in wavelength 365nm. It is from a viewpoint which fully advances a crosslinking reaction, maintaining workability.

However, when the component member for image display devices interposed at the time of irradiating an ultraviolet ray blocks the light of the said wavelength, it is appropriate to adjust the kind of energy ray which an adhesive material responds to according to the kind of polymerization initiator suitably according to the interposition member. desirable.

(Other process)

Between the said process (2) and the said process (3), you may make it insert the process of heating and melting the adhesive layer of a transparent double-sided adhesive material by heating the laminated body obtained by the said process (2). That is, you may make it heat-melt (hot melt) the adhesion layer of this adhesive sheet 3 by heating the laminated body stuck in the process (2).

When this adhesive sheet 3 is heated, the said aggregation of macromonomers will be loosened | dissolved, a physical crosslinked structure will be eliminated, and high fluidity can be expressed. Therefore, when there are unevenness | corrugation, such as a printing level | step, on a surface, when the two structural members for image display apparatus are laminated | stacked, this adhesive sheet 3 is heated and flowed (hot melted), and the uneven | corrugated traceability of an adhesive material and wettability with respect to a to-be-adhered body are carried out. This becomes high and leaves no distortion, and the members can be more firmly integrated.

At this time, it is preferable to heat at 60-100 degreeC and to hot melt. If it is 60 degreeC or more, the fluidity | liquidity of an adhesive material can fully be provided, and an adhesive resin composition can be fully filled with an uneven part. On the other hand, if it is 100 degrees C or less, not only can a heat damage be given to the structural member for image display apparatuses which are a to-be-adhered body, but an adhesive material flows too much and it can also prevent the adhesive resin composition from being pushed out or crushed.

From such a viewpoint, it is preferable that hot melt temperature is 60-100 degreeC, and especially it is more preferable that it is 62 degreeC or more or 95 degreeC or less, especially 65 degreeC or more or 90 degrees C or less.

(This image display device 3)

The image display apparatus (henceforth "this image display apparatus 3") can also be comprised using this adhesive sheet 3 or the said laminated body for image display apparatus structures.

For example, the image display device 3 includes at least two constitution members for facing an image display device, and at least one of the constitution members for an image display device has an image display having a light impermeable portion and a light transmitting portion on a bonding surface. In an apparatus, the image display apparatus provided with the structure which is filled with the adhesive sheet between the said two image display apparatus structural members is mentioned. Under the present circumstances, the gel fraction of the position which contact | connects the said light transmitting part of the said adhesive sheet can be 50% or more, and the gel fraction of the position which contact | connects the said light impermeable part can be made less than 5%.

The laminated body 3 for this image display apparatus structure, and this image display apparatus 3 WHEREIN: The part which does not permeate | transmit the light of the wavelength required for photocuring, such as the printing part of the screen periphery (it calls this "light impermeable part" in this invention) And when the component for image display device having a part of the light transmitting wavelength (referred to as "light transmitting part" in the present invention) on the bonding surface and the other member for image display device are joined together, By setting the gel fraction of the position in contact with the light-transmissive portion to less than 1% and the gel fraction of the position in contact with the light-transmissive portion to 40% or more, the stress exerted by the light-impermeable portion can be alleviated. The resulting deformation can be reduced, and the adherends can be firmly adhered to each other with high cohesion.

An example of the specific example of the preferable manufacturing method of this image display apparatus 3 is demonstrated.

First, this adhesive sheet 3 is heated and hot-melted, and the component for image display apparatus which has a printing part, ie, a light impermeable part, and the component for image display apparatus are laminated | stacked through this adhesive sheet 3. In this step, since the present adhesive sheet 3 is moderately flexible, the adhesive sheet 3 can sufficiently follow the step while maintaining the storage stability.

Next, light, such as an ultraviolet-ray, is irradiated from the outer side of the structural member for image display apparatuses. Then, since the printing portion shields the light, the light does not reach the portion in contact with the printing portion, or the reaching light is significantly limited, whereas the light reaches the portion in contact with the light transmitting portion without the printing portion, and this portion The crosslinking reaction can proceed to photocuring, and excellent peeling resistance and foaming resistance can be realized.

Examples of the constituent members for the two image display apparatuses include an image display apparatus such as a personal computer, a mobile terminal (PDA), a game machine, a television (TV), a car navigation system, a touch panel, a pen tablet, and the like. The structural member of this is mentioned. More specifically, the laminated body which consists of any one of the group which consists of a touch panel, an image display panel, a surface protection panel, and a polarizing film, or a combination of 2 or more types is mentioned, for example.

[Explanation of phrases]

Generally, "sheet" is thin in the definition in JIS, and refers to a product whose thickness is small and flat compared to length and width. Generally, "film" is extremely small compared to length and width, and the maximum thickness is It is a thin flat product, which is arbitrarily defined, and is usually supplied in the form of a roll (Japanese Industrial Standard JIS K6900). However, since the boundary between a sheet and a film is not certain, and it is not necessary to distinguish both in the dialect in this invention, even if it is called "film" in this invention, suppose that "sheet" is included and "sheet" In this case, the "film" shall be included.

In addition, when expressed as a "panel" like an image display panel, a protective panel, etc., a plate body, a sheet and a film, or these laminated bodies are included.

In this specification, when it describes as "X-Y" (X and Y are arbitrary numbers), unless it mentions specially, with the meaning of "X or more and Y or less", it is "preferably larger than X" or " Preferably smaller than Y &quot;.

In addition, when describing as "X or more" (X is arbitrary number), unless otherwise indicated, it contains the meaning of "preferably larger than X", and describes as "Y or less" (Y is arbitrary number). In one case, unless otherwise stated, the phrase "preferably less than Y" is included.

(Example)

Hereinafter, the embodiment will be described in more detail. However, the present invention is not limited at all by these.

Example 1-1

As a (meth) acrylic-type copolymer (1-A), 15 mass parts (18 mol%) and polybutyl methacrylate macromonomer (Tg: 105 degreeC) of number average molecular weight 2400 and butyl acrylate (Tg: -55 degreeC) 81 1 kg of acrylic copolymer (1-A-1) (weight average molecular weight: 230,000) formed by random copolymerization of 4 mass parts (7 mol%) of mass parts (75 mol%) and acrylic acid (Tg: 106 ° C.) and a crosslinking agent (1 -B), 75 g of glycerin dimethacrylate (manufactured by Nichi Corporation, product name: GMR) (1-B-1), 2,4,6-trimethylbenzophenone and 4-methyl as photopolymerization initiator (1-C) 15 g of a mixture of benzophenone (manufactured by Lanberti, product name: Ezacure TZT) (1-C-1) was uniformly mixed to prepare an adhesive composition 1-1.

Two release films, ie, two polyethylene terephthalate films ("Dia foil MRV-V06" made by Mitsubishi Jushi Co., Ltd., thickness 100 micrometers / "Dia foil MRQ" by Mitsubishi Jushi Co., Ltd. make the said composition 1-1 the peeling process, thickness 75) It sandwiched in between, and shape | molded to sheet shape so that it might become 150 micrometers in thickness using a laminator, and produced the adhesive sheet 1-1 (150 micrometers in thickness).

Printing that does not transmit ultraviolet light having a thickness of 60 μm to a peripheral portion (20 mm on the long side and 17 mm on the short side) of glass having a thickness of 238 mm × 182 mm × 0.8 mm, and a non-printing part is 198 mm × 148 mm. A glass plate with a step was prepared.

One release film of the adhesive sheet 1-1 was peeled off, and it roll-bonded to the soda lime glass of 150 mm x 200 mm thickness 1mm.

Subsequently, the remaining release film was peeled off, and four sides of the adhesive face were caught on the printing step on the printing surface of the glass plate with the printing step, and press-pressed using a vacuum press (absolute pressure 5 kPa, temperature 80 ° C., press pressure 0.04 MPa). ) And autoclave treatment (80 ° C., gauge pressure of 0.2 MPa, 20 minutes) were carried out to complete the adhesion. From the glass side which printed, ultraviolet-ray was irradiated with the high pressure mercury lamp so that the ultraviolet-ray of wavelength 365nm might reach 2000mJ / cm <2> to the adhesive sheet 1-1, hardened the adhesive sheet 1-1, and produced the laminated body 1-1. .

Example 1-2

As a (meth) acrylic-type copolymer (1-A), 55 mass parts (36 mol%) of 2-ethylhexyl acrylate (Tg: -70 degreeC), and 40 mass parts (56 mol%) of vinyl acetate (Tg: 32 degreeC) And 1 kg of acrylic copolymer (1-A-2) (weight average molecular weight: 170,000) formed by random copolymerization of 5 parts by mass (8 mol%) of acrylic acid (Tg: 106 ° C) as a crosslinking agent (1-B). 75 g of epsilon caprolactone modified isocyanuric acid triacrylates (1-B-2) (made by Shin-Nakamura Chemical Corporation, a brand name: A9300-1CL), and a photoinitiator (1-C), Ezacure KTO46 (1-C) -2) 5 g of (manufactured by Lanberti) were uniformly mixed to prepare pressure-sensitive adhesive composition 1-2.

The said composition 1-2 was shape | molded in the sheet form like Example 1-1, and the adhesive sheet 1-2 (thickness 150 micrometers) was produced.

Except having used the adhesive sheet 1-2, it carried out similarly to Example 1-1, and produced the laminated body 1-2.

Example 1-3

As a (meth) acrylic-type copolymer (1-A), 10 mass parts (17 mol%) of polymethacrylate methyl macromonomers (Tg: 105 degreeC) of number average molecular weight 1400, and 2-ethylhexyl acrylate (Tg: -70) 1 kg of an acrylic copolymer (1-A-3) (weight average molecular weight: 230,000) formed by random copolymerization of 90 parts by mass (83 mol%) and a crosslinking agent (1-B) as a propoxylated pentaerythritol triacryl 50 g of latex (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: ATM-4PL) (1-B-3) and 15 g of 4-methylbenzophenone (1-C-3) as the photopolymerization initiator (1-C) were uniformly mixed to form an adhesive. Compositions 1-3 were prepared.

The said composition 1-3 was shape | molded in the sheet form like Example 1-1, and the adhesive sheet 1-3 (thickness 150 micrometers) was produced.

Except having used the adhesive sheet 1-3, it carried out similarly to Example 1-1, and produced the laminated body 1-3.

Example 1-4

As a (meth) acrylic-type copolymer (1-A), 12 mass parts (19 mol%) of polymethyl methacrylate macromonomers (Tg: 105 degreeC) of number average molecular weight 2400, and 2-ethylhexyl acrylate (Tg: -70) 1 kg of an acrylic copolymer (1-A-4) (weight average molecular weight: 80,000) formed by random copolymerization of 85 parts by mass (74 mol%) and 3 parts by mass (7 mol%) of acrylic acid (Tg: 106 ° C.), As a crosslinking agent (1-B), 90 g of glycerin dimethacrylate (made by Nichiyo, product name: GMR) (1-B-1), and Ezacure KTO46 (1-C-2) as a photoinitiator (1-C) 5g (manufactured by Lanberti) was uniformly mixed to prepare an adhesive composition 1-4.

The said composition 1-4 was shape | molded in the sheet form like Example 1-1, and the adhesive sheet 1-4 (thickness 150 micrometers) was produced.

Except having used the adhesive sheet 1-4, it carried out similarly to Example 1-1, and produced the laminated body 1-4.

Comparative Example 1-1

Laminated body 5 was produced as follows, corresponding to the example of international publication 2012/032995.

As (meth) acrylic copolymer (1-A), 75 mass parts (57 mol%) of 2-ethylhexyl acrylate (Tg: -70 degreeC), 20 mass parts (33 mol%) of vinyl acetate (Tg: 32 degreeC), To 1 kg of an acrylic copolymer (1-A-5) formed by random copolymerization of 5 parts by mass (10 mol%) of acrylic acid (Tg: 106 ° C), trimethylolpropane triacrylate (1-B-) as a crosslinking agent (1-B) 4) 10 g of 4-methylbenzophenone (1-C-3) was mixed and added as 200 g and a photoinitiator (1-C), and the resin composition for intermediate | middle layers was prepared. The said resin composition for intermediate | middle layers was sandwiched between two polyethylene terephthalate films (Panacox agent, NP75Z01, 75 micrometers in thickness / Toyo spinning yarn, E7006, 38 micrometers in thickness) which carried out the peeling process, so that it might become thickness of 80 micrometers. It molded in the sheet form and produced the intermediate | middle layer sheet ((alpha)).

Then, 20 g of 4-methylbenzophenone (1-C-3) is added and mixed as a photoinitiator (1-C) with respect to 1 kg of the said acrylic copolymer (1-A-5), and the resin composition for adhesive layers is It prepared.

The said resin composition for adhesive layers was made into two release films, ie, two polyethylene terephthalate films (Diafoil MRA by Mitsubishi Jushi Co., Ltd., thickness 75 micrometers / "E7006" by Toyo spinning company, 38 micrometers in thickness). It sandwiched in between, it shape | mold in sheet form so that it might become thickness of 35 micrometers, and produced the resin sheet (beta) for adhesive layers.

Furthermore, the resin composition for adhesive layers was sandwiched between two polyethylene terephthalate films (Mitsubishi Jushi Co., Ltd., diafoil MRF, thickness 75 micrometers / toy spinning company made, E7006, thickness 38 micrometers) which carried out the peeling process, and thickness 35 It was shaped into a sheet so as to have a thickness of µm, and a resin sheet (β ') for an adhesive layer was produced.

While peeling and removing the PET film of both sides of the intermediate | middle layer sheet ((alpha)) sequentially, the PET film of one side of the adhesive sheets ((beta)) and ((beta ')) is peeled off, and the exposed adhesive surface was made into the intermediate | middle layer sheet ((alpha)). The two-sided adhesive sheet which consists of ((beta)) / ((alpha)) / ((beta ')) was sequentially bonded together to both surfaces of the.

Via a PET film remaining on the surfaces of (β) and (β '), ultraviolet rays are irradiated with a high pressure mercury lamp so that the amount of accumulated light having a wavelength of 365 nm is 1000 mJ / cm 2, and (α), (β) and (β'). ) Was crosslinked with ultraviolet rays to prepare Adhesive Sheet 1-5 (thickness: 150 µm).

Except having used the adhesive sheet 1-5, it carried out similarly to Example 1-1, and produced the laminated body 1-5.

Comparative Example 1-2

As a (meth) acrylic-type copolymer (1-A), about 1 kg of commercially available acrylic adhesive (1-A-6) (made by Soken Chemical company, brand name "SK dyne 1882"), isocyanate type hardening | curing agent (made by Soken Chemical Company, brand name " L-45 ") 1.85g and 0.5g of epoxy-type hardening | curing agents (the Soken Chemical company make, brand names" E-5XM ") were mixed uniformly, and the adhesive composition 1-6 was prepared.

The said composition 1-6 is apply | coated to the mold release surface of 50 micrometers in thickness, ie, the release surface of the polyethylene terephthalate film ("MRF75" by Mitsubishi Jushi company: thickness 75 micrometers made by Mitsubishi Jushi Co., Ltd.) so that thickness after drying may be set to 75 micrometers, and it heats The solvent was dried to prepare a pressure-sensitive adhesive sheet having a thickness of 75 µm.

Furthermore, the said composition 1-6 is apply | coated so that the thickness after drying may be 75 micrometers to the mold release surface of a release film, ie, the polyethylene terephthalate film ("Dia foil MRV-V06" made by Mitsubishi Jushi Corporation, thickness 100 micrometers), The solvent was dried by heating to prepare an adhesive sheet having a thickness of 75 µm.

The produced two adhesive sheets adhered each adhesive surface, and cured for 1 week, and produced adhesive sheet 1-6 (thickness 150 micrometers).

Printing that does not transmit ultraviolet light having a thickness of 60 μm to a peripheral portion (20 mm on the long side and 17 mm on the short side) of glass having a thickness of 238 mm × 182 mm × 0.8 mm, and a non-printing part is 198 mm × 148 mm. A glass plate with a step was prepared.

One release film of the adhesive sheet 1-6 was peeled off, and it roll-bonded to the soda lime glass of 150 mm x 200 mm thickness 1mm.

Subsequently, the remaining release film was peeled off, and four sides of the adhesive face were caught on the printing step on the printing surface of the glass plate with the printing step, and press-pressed using a vacuum press (absolute pressure 5 kPa, temperature 80 ° C., press pressure 0.04 MPa). ), Autoclave treatment (80 ° C., gauge pressure of 0.2 MPa, 20 minutes) was carried out, and the final bonding was carried out to prepare laminate 1-6.

Comparative Example 1-3

In accordance with the example of WO2010038366, the laminate 1-7 was produced as follows.

As a replacement for the (meth) acrylic copolymer (1-A), 650 g of a phenoxy resin (1-A-7) (manufactured by InChem, PKHH, weight average molecular weight 5.2 million) and a crosslinking agent (1-B), 1-cyclohexylphenyl ketone (1-C) as 1 kg of polyurethane acrylate (1-B-4) (made by Negami Co., Ltd., UN5500, weight average molecular weight 6.7 million) which has a carbonate skeleton, a photoinitiator (1-C) -4) The pressure-sensitive adhesive composition 1-7 obtained by uniformly mixing 43 g (manufactured by BASF Corporation, Irgacure184) was prepared.

The said composition 1-7 was shape | molded in the sheet form like Example 1-1, and the adhesive sheet 1-7 (thickness 150 micrometers) was produced.

Printing that does not transmit ultraviolet light having a thickness of 60 μm to a peripheral portion (20 mm on the long side and 17 mm on the short side) of glass having a thickness of 238 mm × 182 mm × 0.8 mm, and a non-printing part is 198 mm × 148 mm. A glass plate with a step was prepared.

One release film of the adhesive sheet 1-7 was peeled off, and it rolled together to 80 degreeC of soda-lime glass of 150 mm x 200 mm thickness, heating at 80 degreeC.

Subsequently, the remaining release film was peeled off, and four sides of the adhesive face were caught on the printing step on the printing surface of the glass plate with the printing step, and press-pressed using a vacuum press (absolute pressure 5 kPa, temperature 80 ° C., press pressure 0.04 MPa). ) And autoclave treatment (80 ° C., gauge pressure of 0.2 MPa, 20 minutes) were carried out to complete the adhesion. From the glass side which printed, the ultraviolet-ray was irradiated with the high pressure mercury lamp so that the ultraviolet-ray of wavelength 365nm might reach 2000mJ / cm <2> on the adhesive sheet, the adhesive sheet 1-7 was hardened | cured, and the laminated body 1-7 was produced.

[evaluation]

The adhesive sheet and laminated body which were produced by the Example and the comparative example were evaluated as follows.

(Viscosity measurement)

Using a plurality of PSA sheets 1-1 to 1-7 prepared in Examples and Comparative Examples, each was laminated so as to have a thickness of 1 mm to 2 mm, and a flat sheet having a diameter of 20 mm was produced.

Adhesion jig: Φ 25mm parallel plate, distortion: 0.5%, frequency: 1Hz, temperature increase rate: 3 degrees Celsius / min at 70 degrees Celsius-120 degrees Celsius using a rheometer ("MARS" made by Eiko Seiki Co., Ltd.) The complex viscosity of the pressure sensitive adhesive sheet before photocuring was measured.

About the adhesive sheets 1-1 to 1-5 and 1-7, ultraviolet-ray is irradiated to an adhesive sheet through a polyethylene terephthalate film so that the accumulated light amount of 365 nm may be set to 2000 mJ / cm <2> using a high pressure mercury lamp, The adhesive sheet was cured. The adhesive sheet after hardening was laminated | stacked so that it might become thickness of 1 mm-2 mm, and the thing punched out to the circular shape of diameter 20mm was produced.

Adhesion jig: Φ 25mm parallel plate, distortion: 0.5%, frequency: 1Hz, temperature increase rate: 3 ° C / min at 70 ° C to 120 ° C using a rheometer (`` MARS '' manufactured by Aiko Seiki Co., Ltd.) The complex viscosity of the pressure sensitive adhesive sheet after fire was measured.

 (Adhesion after curing)

One release film of the adhesive sheets 1-1 to 1-7 produced by the Example and the comparative example was peeled off, and 50 micrometers PET film (made by Mitsubishi Jushi Co., Ltd., diafoil T100, thickness 50 micrometers) was laminated | stacked and laminated | stacked as a contacting film. The bosom was prepared.

After cutting the said laminated product into length 150mm and width 10mm, the remaining release film was peeled off and the exposed adhesive surface was roll-bonded to the soda lime glass for 1 round of 2 kg of rolls. After performing the autoclave treatment (80 degreeC, gauge pressure 0.2MPa, 20 minutes) to a pasted product, and sticking it, it irradiates an ultraviolet-ray to the accumulated light amount of 365 nm to 2000mJ / cm <2>, and hardens an adhesive sheet for 15 hours. It cured and set it as the peeling force measurement sample.

Peeling force (N / cm) with respect to glass when the said peeling force measurement sample is peeled off in the environment of 23 degreeC 40% RH and 80 degreeC 10% RH at 180 degree peeling angle and 60 mm / min of peeling speed is measured. And the adhesive strength after hardening was calculated | required.

(Adhesion before hardening)

One release film of the adhesive sheets 1-1 to 1-7 produced by the Example and the comparative example was peeled off, and 50 micrometers PET film (made by Mitsubishi Jushi Co., Ltd., diafoil T100, thickness 50 micrometers) was laminated | stacked and laminated | stacked as a contacting film. The bosom was prepared.

After cutting the said laminated product into length 150mm and width 10mm, the remaining release film was peeled off and the exposed adhesive surface was rolled 1 kg of 2 kg in soda lime glass, and the said adhesive sheet was roll-pressed.

Peeling force (N / cm) with respect to glass when this adhesive force measurement sample is peeled off in the environment of 23 degreeC 40% RH and 80 degreeC 10% RH at 180 degree peeling angle and 60 mm / min of peeling rates is measured, And the adhesive force before hardening were calculated | required.

In addition, about the peeling mode at the time of peeling in 80 degreeC 10% RH environment, "CF" and the thing which were interfacial peeling were described in the table as "AF" that it was cohesive failure.

(Transparency)

One release film of the adhesive sheets 1-1 to 1-7 produced by the Example and the comparative example was peeled off, and the exposed adhesive surface was rolled on two sheets of soda lime glass (82 mm x 53 mm x 0.5 mm thickness). After sticking, autoclave treatment (80 degreeC, gauge pressure 0.2 MPa, 20 minutes) was performed, the final sticking was carried out, and the laminated body for optical evaluation was produced.

About the said laminated body, the haze value according to JISK7136 and the total light transmittance (%) according to JIS K7361-1 were calculated | required using the haze meter (NDH5000 by Nippon Denshoku Industries Co., Ltd.).

(Paste workability)

In the preparation of the laminate for optical evaluation, when the sheets produced in Examples and Comparative Examples were abutted on soda lime glass, they were roll-bonded in an environment of 23 ° C and 40% to be able to be fixed closely to the glass plate. And the glass plate and the sheet | seat did not adhere in the environment of 40 degreeC of 23 degreeC, and it was determined as "x (poor)" that heating was needed at the time of roll bonding.

(Out gas analysis)

The outgas after light irradiation by this invention is detected by the following analysis method.

(Out gas generation method)

The adhesive sheets 1-1 to 1-5 and 1-7 produced by the Example and the comparative example were adhere | attached through the polyethylene terephthalate film so that the accumulated light amount of 365 nm may be 2000 mJ / cm <2> using a high pressure mercury lamp. Ultraviolet was irradiated to the sheet | seat, and the adhesive sheet corresponded after photocuring was created. The adhesive sheet after photocuring was cut out to 1 cm x 3 cm, and put into a 20 ml vial bottle and sealed. The vial bottle was placed in a xenon UV irradiation apparatus (Sun Test CPS: manufactured by Toyo Seiki), and UV irradiation treatment was performed at an illuminance of 765 W / m 2 and a temperature of 60 ° C. for 24 hours.

The adhesive sheets 1-6 of Comparative Example 1-2 were cut out to 1 cm x 3 cm, and put into a 20 ml vial bottle to be sealed. The vial bottle was placed in a xenon UV irradiation apparatus (Sun Test CPS: manufactured by Toyo Seiki), and UV irradiation treatment was performed at an illuminance of 765 W / m 2 and a temperature of 60 ° C. for 24 hours.

(Out gas analysis method)

The generated gas from the resin composition processed by UV as mentioned above can be measured by the gas chromatography analysis method (HS-GC) equipped with the head space sampler.

(1) collection of analytical gases

The generated gas of the said adhesive sheet was collected on condition of the following.

HS Sampler: Tubo Matrix 40 (manufactured by Perkin Elmer)

2. Heating temperature: 80 ℃

3. Heating time: 30 minutes

4. Needle temperature: 110 ℃

5. Transfer temperature: 170 ℃

6. Injection time: 0.1 minutes

7. Column pressure: 16.0 psi

(2) GC analysis

The generated gas was analyzed by GC (Clarus580, manufactured by Perkin Elmer), and the amount of out gas generated was quantified in hexadecane conversion.

(Uneven absorbency)

The laminates 1-1 to 1-7 prepared in the examples and the comparative examples were visually observed, and `` x (poor) '' was observed in the vicinity of the printing step, and bubbles were left in the vicinity of the printing step. It was judged that "(triangle | delta)" that the originating nonuniformity was seen, and the thing which joined together smoothly without bubble was "(good)".

(Expansion Reliability)

The laminated bodies 1-1 to 1-7 which were produced by the Example and the comparative example were put into the xenon UV irradiation apparatus (preliminary test CPS: made by Toyo Seiki), and UV irradiation treatment was performed for 24 hours at roughness 765W / m <2> and 60 degreeC of temperature. The external appearance was observed.

It was determined that "x (poor)" that bubbles having a diameter of 5 mm or more occurred in the pressure sensitive adhesive sheet, "△ (usual)" that bubbles having a diameter of 5 mm or less were seen, and that "o" (good) had no appearance change without foaming. .

(Review)

The adhesive sheets produced in Examples 1-1 to 1-4 have excellent wettability to the adherend surface and followability to the uneven surface, as can be seen from the fact that the peeling mode at high temperature before photocuring is cohesive failure. Not only was it excellent, but the adhesive force after photocuring was high. Therefore, using the adhesive sheets produced in Examples 1-1 to 1-4, a laminate having high reliability without causing peeling, foaming or deformation even under severe environmental tests such as long-term ultraviolet irradiation under high temperature. Could get

In addition, the adhesive sheets produced in Examples 1-1 to 1-4 were shape retainable at 0-40 degreeC, and also showed self-adhesiveness.

In the adhesive sheet of Comparative Example 1-1, when the adhesive resin composition is partially crosslinked by ultraviolet irradiation, that is, when laminated with glass having a printing step due to the state after photocuring, the adhesive sheet is caused by residual distortion of the adhesive sheet in the vicinity of the printing step. Unevenness was seen, and appearance of the pasting was inferior. Moreover, after photocuring this again, since adhesive force was low and cohesion force fell, foaming was seen by the ultraviolet irradiation test, and bonding reliability was also inferior.

In Comparative Example 1-2, since the crosslinking reaction of the pressure-sensitive adhesive resin composition was already completed at the previous stage to be bonded to the member, no change was observed in the viscosity or adhesive force even when irradiated with ultraviolet rays. Moreover, when laminating | stacking with the glass with a printing level | step, some adhesives were not fully filled and the bubble remained in the vicinity of the edge part where a printing level | step crosses. Moreover, the bubble growth was seen in the ultraviolet irradiation test by the distortion of the adhesive material of step vicinity.

Comparative Example 1-3 is a hot-melt type adhesive sheet using an adhesive resin composition having some rigidity in the room temperature region without using a (meth) acrylic copolymer as a main component.

As can be seen from the fact that the adhesive force before photocuring is low, the sheet of Comparative Example 1-3 has very low tackiness in the vicinity of room temperature in comparison with the pressure-sensitive adhesive sheet of the example, Self-adhesiveness was insufficient. The adhesive sheet of Comparative Example 1-3 needs to preheat a to-be-adhered body from the stage of positioning when sticking together, and there existed a problem that work was complicated compared with the adhesive sheet which can be attached at normal temperature only by crimping | bonding.

Example 2-1

As a (meth) acrylic-type copolymer (2-A), 15 mass parts (18 mol%) of macromonomers of the number average molecular weight 2900 which consist of methyl polymethacrylate (Tg: 105 degreeC), and butyl acrylate (Tg: -55) 1 g of acrylic graft copolymer (2-A-1) (weight average molecular weight: 230,000) formed by random copolymerization of 81 parts by mass (75 mol%) and 4 parts by mass (7 mol%) of acrylic acid (Tg: 106 ° C.) 90 g of glycerin dimethacrylate (manufactured by Nichi Corporation, product name: GMR) (2-B-1) as a crosslinking agent (2-B), and 2,4,6-trimethylbenzofe as a photopolymerization initiator (2-C) 15 g of a mixture of paddy rice and 4-methylbenzophenone (manufactured by Lanberti, product name: Ezacure TZT) (2-C-1) was uniformly mixed to prepare an adhesive resin composition 2-1.

Polyethylene terephthalate film Y (made by Mitsubishi Jushi Co., Ltd., diamond foil MRV-V06, thickness 100 micrometers, "release film Y") and peeling process polyethylene terephthalate film Z (made by Mitsubishi Jushi Co., Ltd., diamond foil QQ) The said composition 2-1 was sandwiched between 75 micrometers of thickness and "release film Z", and it shape | molds to sheet shape so that it may become 150 micrometers in thickness using a laminator, and adhesive sheet X1 (thickness 150 micrometers) is made Produced.

A double-sided tape was attached to one side of a black sheet (LSL-8 Inoax Light Transmittance 0%) and cut into 50 mm x 100 mm, and the sheet was cut onto the surface of the release film Z laminated on one side of the pressure-sensitive adhesive sheet X1. The transparent part was formed and the adhesive sheet laminated body which has a light transmitting part and a light impermeable part in the sheet surface was produced.

Next, using a high-pressure mercury lamp, ultraviolet rays are irradiated from the black sheet side of the pressure-sensitive adhesive sheet laminate thus produced so that the accumulated light amount at a wavelength of 365 nm is 2000 mJ / cm 2, and the light transmitting portion of the pressure-sensitive adhesive sheet laminate is cured. , The pressure-sensitive adhesive sheet 2-1 having the soft portion and the hard portion was produced. (See FIG. 2).

Here, a soft part means the site | part of the adhesive sheet shielded by the black sheet, and a hard part means the site | part of the adhesive sheet which is not shielded by the black sheet.

Example 2-2

As a (meth) acrylic-type copolymer (2-A), 55 mass parts (36 mol%) of 2-ethylhexyl acrylate (Tg: -70 degreeC), and 40 mass parts (56 mol%) of vinyl acetate (Tg: 32 degreeC) And 1 kg of acrylic copolymer (2-A-2) (weight average molecular weight: 170,000) formed by random copolymerization of 5 parts by mass (8 mol%) of acrylic acid (Tg: 106 ° C) as a crosslinking agent (2-B). , 70 g of isocyanuric acid EO-modified diacrylate and isocyanuric acid EO-modified triacrylate (2-B-2) (manufactured by Dong-A Synthetic Co., Ltd., product name: Aronix M313), and photopolymerization initiator (2-C) As an example, 5 g of Ezacure KTO46 (2-C-2) (manufactured by Lanberti) was uniformly mixed to prepare an adhesive resin composition 2-2.

The said composition 2-2 was sandwiched between the said release films Y and Z, and it shape | molded to sheet shape so that it might become 150 micrometers in thickness using a laminator, and the adhesive sheet X2 (thickness 150micrometers) was produced.

Except having used the adhesive sheet X2, the adhesive sheet laminated body was produced like Example 2-1, and also the adhesive sheet 2-2 which has a soft part and a hard part was produced similarly to Example 2-1.

Example 2-3

As a (meth) acrylic-type copolymer (2-A), 10 mass parts (17 mol%) of polymethyl methacrylate macromonomer (Tg: 105 degreeC) of number average molecular weight 1400, and 2-ethylhexyl acrylate (Tg: -70) 1 g of acrylic graft copolymer (2-A-3) (weight average molecular weight: 230,000) formed by random copolymerization of 90 parts by mass (83 mol%) and tricyclodecanedimethacryl as a crosslinking agent (2-B) A mixture of 50 g of latex (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: DCP) (2-B-3) and 2,4,6-trimethylbenzophenone and 4-methylbenzophenone as photopolymerization initiator (2-C) (manufactured by Lanberti, Product name: 15 g of Ezacure TZT) (2-C-1) was uniformly mixed to prepare an adhesive resin composition 2-3.

The said composition 2-3 was sandwiched between the said release films Y and Z, and it shape | molded to sheet shape so that it might become 150 micrometers in thickness using a laminator, and the adhesive sheet X3 (thickness 150 micrometers) was produced.

Except having used the adhesive sheet X3, the adhesive sheet laminated body was produced like Example 2-1, and also the adhesive sheet 2-3 which has a soft part and a hard part was produced similarly to Example 2-1. .

Example 2-4

As a (meth) acrylic-type copolymer (2-A), 12 mass parts (19 mol%) of polymethyl methacrylate macromonomers (Tg: 105 degreeC) of number average molecular weight 2400, and 2-ethylhexyl acrylate (Tg: -70) 1 g of acrylic graft copolymer (2-A-4) (weight average molecular weight: 80,000) formed by random copolymerization of 85 parts by mass (74 mol%) and 3 parts by mass (7 mol%) of acrylic acid (Tg: 106 ° C.) , 90 g of glycerin dimethacrylate (manufactured by Nichi Corporation, product name: GMR) (2-B-1) as a crosslinking agent (2-B), and 2,4,6-trimethylbenzofe as a photopolymerization initiator (2-C) 15 g of a mixture of paddy rice and 4-methylbenzophenone (manufactured by Lanberti, product name: Ezacure TZT) (2-C-1) was uniformly mixed to prepare an adhesive resin composition 2-4.

The said composition 2-4 was sandwiched between the said release films Y and Z, and it shape | molded in the sheet form so that it might become 150 micrometers in thickness using a laminator, and the adhesive sheet X4 (thickness 150 micrometers) was produced.

Except having used the adhesive sheet X4, the adhesive sheet laminated body was produced like Example 2-1, and was carried out similarly to Example 2-1, and the adhesive sheet 2-4 which has a soft part and a hard part was produced. .

Example 2-5

1 kg of acrylic copolymer (2-A-1) (weight average molecular weight: 230,000) used in Example 2-1, 70 g of trimethylolpropanetriacrylate (2-B-4) as a crosslinking agent (2-B); 8 g of a mixture of 2,4,6-trimethylbenzophenone and 4-methylbenzophenone (manufactured by Lanberti, product name: Ezacure TZT) (2-C-1) as a photopolymerization initiator (2-C) was uniformly mixed Resin composition 2-5 was produced.

Polyethylene terephthalate film Y (made by Mitsubishi Jushi, DIA foil MRV-V06, thickness 100 micrometers) which carried out the solution which diluted adhesive resin composition 2-5 so that solid content concentration was 40% with ethyl acetate, "release film Y" Polyethylene terephthalate film Z (made by Mitsubishi Jushi Co., Ltd., diamond foil MRQ, thickness 75 micrometers) which carried out the application | coating and drying to the peeling process surface of the said) so that the thickness after drying may be set to 25 micrometers, and then coated on the coated adhesive surface. The "release film Z" was coat | covered and the adhesive sheet X5 (25 micrometers in thickness) was produced.

Except having used the adhesive sheet X5, the adhesive sheet laminated body was produced like Example 2-1, and also the adhesive sheet 2-5 which has a soft part and a hard part was produced similarly to Example 2-1. .

[Comparative Example 2 -1]

75 mass parts (57 mol%) of 2-ethylhexyl acrylate (Tg: -70 degreeC), 20 mass parts (33 mol%) of vinyl acetate (Tg: 32 degreeC), and 5 mass parts (10 mol%) of acrylic acid (Tg: 106 degreeC) ) 200 g of trimethylolpropanetriacrylate (2-B-4) and 10 g of 4-methylbenzophenone (2-C-3) in 1 kg of a (meth) acrylic copolymer (2-A-5) formed by random copolymerization) Was mixed and added to prepare a resin composition for intermediate layers.

The said resin composition for intermediate | middle layers was sandwiched between two polyethylene terephthalate films (Panacox agent, NP75Z01, 75 micrometers in thickness / Toyo spinning yarn, E7006, 38 micrometers in thickness) which carried out the peeling process, so that it might become thickness of 80 micrometers. It shape | molded in the sheet form and created the sheet | seat ((alpha)) for intermediate | middle layers.

Subsequently, 20 g of 4-methylbenzophenone (2-C-3) is added and mixed as the photopolymerization initiator (2-C) to 1 kg of the acrylic copolymer (2-A-5) to prepare a resin composition for the adhesive layer. It prepared.

The said resin composition for adhesion layers was sandwiched between two polyethylene terephthalate films (Mitsubishi Jushi Co., Ltd., diafoil MRA, thickness 75 micrometers / toy spinning company made, E7006, thickness 38 micrometers) which carried out the peeling process, and is 35 micrometers in thickness. It shape | molded to sheet form so that it might become, and the resin sheet ((beta)) for adhesion layers was produced.

On the other hand, the resin composition for adhesion layers was sandwiched between two polyethylene terephthalate films (Mitsubishi Jushi Co., Ltd., diamond foil MRF, thickness 75 micrometers / toy spinning company made, E7006, thickness 38 micrometers) which carried out the peeling process, and thickness 35 It shaped into sheet shape so that it might become micrometer, and the resin sheet for adhesive layers ((beta ')) was produced.

While peeling and removing the PET film of both sides of the intermediate | middle layer sheet ((alpha)) sequentially, the PET film of one side of the adhesive sheets ((beta)) and ((beta ')) is peeled off, and the exposed adhesive surface was made into the intermediate | middle layer sheet ((alpha)). The two-sided adhesive sheet which consists of ((beta)) / ((alpha)) / ((beta ')) was sequentially bonded together to both surfaces of the.

Via a PET film remaining on the surfaces of (β) and (β '), ultraviolet rays are irradiated with a high pressure mercury lamp so that the amount of accumulated light having a wavelength of 365 nm is 1000 mJ / cm 2, and (α), (β) and (β'). ) Was subjected to ultraviolet crosslinking to prepare an adhesive sheet X6 (thickness: 150 µm).

Polyethylene terephthalate film (manufactured by Mitsubishi Jushi Co., Ltd.) which peeled off one side of the adhesive sheet X6 by attaching a double-sided tape to one side of a black sheet (0% light transmittance made by LSL-8 Inoax) and cutting it to 50 mm x 100 mm. It adhere | attached on the surface of diamond foil MRF), the light impermeability was formed, and the adhesive sheet laminated body which has a light transmission part and a light impermeability part in the sheet surface was produced.

Next, using the high pressure mercury lamp, the ultraviolet ray is irradiated so that the accumulated light amount of wavelength 365nm will be 2000mJ / cm <2> from the black sheet side of the adhesive sheet laminated body which produced this adhesive sheet and contact | connects the light transmitting part of a laminated body. Was further irradiated with the pressure-sensitive adhesive of to prepare an adhesive sheet 2-6.

[Comparative Example 2 -2]

Polyurethane acrylate (2-B-4) which has a carbonate frame | skeleton as a substitute of 650 g of phenoxy resins (2-A-6) (made by InChem, PKHH, weight average molecular weight 5.2 million) and a crosslinking agent (2-B) (Made by Negami Co., Ltd., UN5500, weight average molecular weight 6.7 million) As a 1 kg and photoinitiator (2-C), 43-g of 1-cyclohexyl phenyl ketone (2-C-4) (made by BASF, Irgacure184) is uniformly mixed. Adhesive resin composition 2-7 was produced.

The composition 2-7 was sandwiched between two polyethylene terephthalate films (Mitsubishi Jushi Co., Ltd., diamond foil MRV-V06, thickness 100 µm / Mitsubishi Jushi Co., Ltd., diamond foil MRQ, thickness 75 μm). Using a laminator, the sheet was molded into a sheet shape so as to have a thickness of 150 μm, thereby preparing an adhesive sheet X7 (thickness of 150 μm).

Polyethylene terephthalate film (manufactured by Mitsubishi Jushi Co., Ltd.) which peeled off one side of the adhesive sheet X7 by attaching a double-sided tape to one side of a black sheet (0% light transmittance made by LSL-8 Inoax) and cutting it to 50 mm x 100 mm. And the light impermeability were formed by sticking to the surface of diamond foil MRQ), and the adhesive sheet laminated body which has a light transmission part and a light impermeability part in the sheet surface was created.

Next, using a high-pressure mercury lamp, ultraviolet rays are irradiated from the black sheet side of the pressure-sensitive adhesive sheet laminate thus produced so that the accumulated light amount at a wavelength of 365 nm is 2000 mJ / cm 2, and the light transmitting portion of the pressure-sensitive adhesive sheet laminate is cured. And Adhesive Sheet 2-7 were produced.

[Comparative Example 2 -3]

1.85 g of isocyanate-based curing agent (made by Soken Chemical Company, brand name "L-45") and epoxy-based curing agent (Soken) to 1 kg of commercially available acrylic pressure-sensitive adhesive (2-A-7) (manufactured by Soken Chemical Co., Ltd., trade name "SK Dyne 1882") 0.5 g of Chemical Co., Ltd. brand name "E-5XM") was uniformly mixed, and the adhesive resin composition 2-6 was prepared.

The said composition 2-6 is apply | coated to the release surface of the polyethylene terephthalate film (brand name "MRF75": Mitsubishi Jushi Co., Ltd.) which carried out the peeling process of thickness of 50 micrometers so that thickness after drying may be 75 micrometers, and a solvent is dried by heating. To prepare a pressure-sensitive adhesive sheet having a thickness of 75 µm.

Furthermore, the said composition 2-6 was apply | coated to the mold release surface of the polyethylene terephthalate film (Mitsubishi Jushi Co., Ltd., diafoil MRV-V06, thickness 100 micrometers) which peeled, so that the thickness after drying might be 75 micrometers, and it heated by The solvent was dried to prepare an adhesive sheet having a thickness of 75 µm.

About each produced adhesive sheet, each adhesive surface was affixed, cured for 1 week, the hardening | curing agent was made to react, and the adhesive sheet 2-8 (thickness 150 micrometers) was produced.

[evaluation]

The various physical property values of the adhesive sheets 2-1 to 2-8 produced by the Example and the comparative example were measured and evaluated as follows.

(Gel fraction)

The following measurement was performed about taking out the part which contact | connects the light transmission part of the adhesive sheets 2-1 to 2-7 produced by the Example and the comparative example, respectively, the part which contact | connects the light impermeable part, or soft part, respectively. .

About the adhesive sheet 2-8 of Comparative Example 2-3, the following measurement was performed about arbitrary places.

1) The pressure-sensitive adhesive composition is weighed (W1) and wrapped in a 200 mesh SUS mesh W0 weighed in advance.

2) The SUS mesh is immersed in 100 mL of ethyl acetate for 24 hours.

3) The SUS mesh is taken out and dried at 75 ° C. for 4 hours and a half.

4) The weight (W2) after drying is calculated | required, and the gel fraction of an adhesive composition is measured from the following formula.

Gel fraction (%) = 100Σ (W2-W0) / W1

(Glass transition temperature (Tg))

Using a differential scanning calorimeter (DSC-8500) manufactured by Perkin Elmer Co., Ltd., based on JIS K-7121 (ISO3146), the temperature increase was measured at a temperature increase rate of 5 ° C / min. The glass transition temperature (Tg) was calculated | required about the part which contact | connects the light transmissive part of 2-7, ie, the hard part, and the part which contact | connects the light opaque part, respectively.

About the adhesive sheet 2-8 of the comparative example 2-3, the same measurement was performed about arbitrary places.

Asuka hardness

The peeling film of a sheet is peeled off, and the exposed adhesive surface is piled up sequentially, and the several sheets of adhesion are adhered to the part which contact | connects the light-transmissive part of the adhesive sheets 2-1 to 2-7 produced by the Example and the comparative example, and the soft part. The sheets were laminated so that the total thickness was in the range of 5 mm to 7 mm. Thereby, the influence of the hardness of the stage which loads a measurement sample can be reduced, and the indentation hardness peculiar to a material can be compared and measured. And the tip terminal of the Asuka C2L hardness tester was pushed at the speed of 3 mm / min vertically downward by 1 kg of load with respect to the exposed adhesive surface of the laminated adhesive sheet, and the C2 Asuka hardness (c) of the soft part was measured.

In the same manner as above, the adhesive sheet is laminated so as to be within the range of 5 mm to 7 mm, and the C2 of the hard portion is formed in the contacting portion, that is, the hard portion, of the adhesive sheets 2-1 to 2-7 produced in the Examples and Comparative Examples. Asuka hardness (d) was measured.

About the adhesive sheet 2-8 produced by the comparative example 2-3, the same measurement was performed about arbitrary places.

(180 ° peel force of soft part)

After cutting out the part which contact | connects the light impermeable part of the adhesive sheets 2-1 to 2-7 produced by the Example and the comparative example, a soft part, one release film is peeled off and a 50 micrometers PET film (made by Mitsubishi Jushi Co., Ltd.) Diamond foil T100, 50 micrometers in thickness) was stuck together, and the laminated product was prepared.

After cutting the said laminated product into length 150mm and width 10mm, the remaining release film was peeled off and the exposed adhesive surface was rolled 1 kg of 2 kg in soda lime glass, and the said adhesive sheet was roll-pressed.

The point where the adhesive force measurement sample peels (N / cm) with respect to the glass at the time of peeling off at 180 degree peeling angle and peeling rate 60mm / min in 23 degreeC 40% RH environment, and touches an optically opaque part That is, 180 degree peeling force of the soft part was calculated | required.

(180 ° peeling force of the hard part)

One release film was peeled off with respect to the adhesive sheets X1-7 of the state before the light irradiation produced in Examples 2-1 to 2-5 and Comparative Examples 2-1 and 2-2, and a 50 micrometers PET film ( Mitsubishi Jushi Co., Ltd., diamond foil T100, 50 micrometers) were stuck together, and the laminated product was prepared.

After cutting the said laminated product into length 150mm and width 10mm, the remaining release film was peeled off and the exposed adhesive surface was roll-bonded to the soda lime glass for 1 round of 2 kg of rolls. After performing the autoclave treatment (80 degreeC, gauge pressure 0.2MPa, 20 minutes) to a pasted product, and sticking it, it irradiates an ultraviolet-ray to the accumulated light amount of 365 nm to 2000mJ / cm <2>, and hardens an adhesive sheet for 15 hours. It cured and set it as the peeling force measurement sample.

In the environment of 23 degreeC 40% RH, the said peeling force measurement sample measures the peeling force (N / cm) with respect to the glass at the time of peeling off at 180 degree peeling angle and 60 mm / min of peeling rate, and touches a light transmission part. It was set as 180 degree peeling force of a part, ie, a hard part.

About the adhesive sheet 2-8 created by the comparative example 2-3, after cutting out the adhesive sheet about arbitrary places, it measured similarly to the procedure of 180 degreeC peeling force of a soft part.

(Holding power of the soft part)

After cutting the part which contact | connects the light impermeable part of the adhesive sheets 2-1 to 2-7 produced by the Example and the comparative example to 50 mm x 100 mm, the peeling film of one side is peeled off, and the one side of the said adhesive sheet It adhere | attached with the hand roller so that it might overlap on this polyethylene terephthalate film (38 micrometers in thickness) for back contact, This was cut out to the rectangular shape of width 25mm x length 100mm, and it was set as the test piece.

Next, the peeling film which remained was peeled off, and it adhere | attached with the hand roller so that the test piece might be piled up by 20 mm length with respect to the SUS board (thickness 120 mm, 5 mm x 1.5 mm) installed upright. At this time, the adhesion area of a transparent double-sided adhesive sheet and an SUS board is 25 mm x 20 mm.

Thereafter, the test piece was cured in an atmosphere of 40 ° C. and 70 ° C. for 15 minutes, and then a weight of 4.9 N was mounted on the test piece in a vertical direction to allow it to stand for 30 minutes, and then the length where the bonding position between the SUS and the test piece shifted downward. (Mm) was measured. About the dropping of the adhesion surface and the additional fall, the time required for the fall of the weight was measured.

In addition, since the adhesive sheet 2-7 of the comparative example 2-2 does not have self-adhesion property, the test piece laminated | stacked on the SUS board was preheated at 80 degreeC for 5 minutes, and was held in close contact with a to-be-adhered body, and the holding force measurement was performed.

(Holding power of the hard part)

About adhesive sheets X1-7 of the state before the light irradiation produced in Examples 2-1 to 2-5 and Comparative Examples 2-1 and 2-2, it carried out similarly to the holding force measurement before photocuring, After making a laminated body, the polyethylene terephthalate for back contacting while checking the accumulated light quantity with a photometer (Unio Electric Co., UNIMETER UIT250 / Sensor: UVD-C365) so that the ultraviolet-ray of wavelength 365nm may reach 2000mJ / cm <2> in an adhesive sheet. Ultraviolet irradiation was carried out using the high pressure mercury lamp from the film side, and the adhesive sheet corresponded to the part which contact | connects a light transmission part, ie, a hard part.

Thereafter, the specimen was cured for 15 minutes in an atmosphere of 40 ° C. and 70 ° C., and then a weight of 4.9 N was attached to the specimen in a vertical direction, and the specimen was left to stand for 30 minutes. After that, the bonding position between the SUS and the specimen was shifted downward. (Mm) was measured.

The test piece hardly moved, and it described as "<0.1 mm" in Table 3 about the deviation length being less than 0.1 mm.

About the adhesive sheet 2-8 created by the comparative example 2-3, after cutting out the adhesive sheet about arbitrary places, it measured similarly to the holding force measurement procedure of a soft part.

(Transparency)

One release film was peeled off to the part which contact | connects the light transmissive part of the adhesive sheets 2-1 to 2-7 produced by the Example and the comparative example, ie, a hard part, and the exposed adhesive surface was made into two pieces of soda lime glass (82) After roll-joining mm x 53 mm x 0.5 mm), autoclave treatment (80 degreeC, gauge pressure 0.2MPa, 20 minutes) was performed, it stuck together and the laminated body for optical evaluation was produced.

About the adhesive sheet 2-8 created by the comparative example 2-3, the sample was created similarly about arbitrary places.

About the said laminated body, the haze value according to JISK7136 and the total light transmittance (%) according to JIS K7361-1 were calculated | required using the haze meter (NDH5000 by Nippon Denshoku Industries Co., Ltd.).

(Uneven absorbency)

The adhesive sheets X1-4, 6, and 7 of the state before the light irradiation produced by Examples 2-1 to 2-4 and Comparative Examples 2-1 and 2-2 are cut out to 50 mm x 80 mm, and one mold release is performed. The adhesive surface exposed by peeling off the film was vacuumed on the printing surface of soda lime glass (82 mm x 53 mm x 0.5 mm thickness) which printed 80 µm in thickness on the periphery of 3 mm. Press compaction was carried out using a press (absolute pressure 5 kPa, temperature 80 ° C., press pressure 0.04 MPa). Subsequently, the remaining release film was peeled off, and after press-bonding a zeanoa film (Nippon Xeon company, 100 micrometers thickness), autoclave treatment (80 degreeC, gauge pressure 0.2MPa, 20 minutes) was performed and the final sticking was carried out. From the soda-lime glass side which printed, the ultraviolet-ray was irradiated with a high pressure mercury lamp so that the ultraviolet-ray of wavelength 365nm might reach 2000mJ / cm <2> in the sheet | seat X, and the sheet | seat which contact | connects the opening which is not printed, ie, the light transmission part, is opened. It hardened | cured and created laminated bodies 2-1-2-6 for evaluation.

About adhesive sheet X5 created in Example 2-5, the laminated body 2-7 for evaluation was similarly created using what made the printing thickness of the printed soda lime glass into 15 micrometers.

About the adhesive sheet 2-8 created by the comparative example 2-3, the lamination | stacking of the soda lime glass and the zeona film (100 micrometers thickness made by Nippon Zeon) which printed in the same procedure as the above using the adhesive sheet 2-7 After the sieve was prepared, autoclave treatment (80 ° C., gauge pressure of 0.2 MPa, 20 minutes) was performed, and the final bonding was carried out to obtain laminate 2-8 for evaluation.

The produced laminates 2-1 to 2-8 were visually observed, and the "x" and the film were bent in the vicinity of the step and the irregularities caused by the distortion were seen in the vicinity of the printing step without the adhesive material following the step of printing. "△" and the thing bonded together smoothly without bubbles were determined as "(circle)".

(Expansion Reliability)

The evaluation laminates 2-1 to 2-8 prepared in the uneven water absorption evaluation were put in a constant temperature and humidity chamber at 85 ° C and 85% RH, and the appearance after curing for 100 hours was observed. It was determined that "x" and that there was no external appearance change were "(circle)" that bubble was generated in the adhesive sheet.

(Review)

Since the gel fraction of the soft part is less than 1%, the adhesive sheets produced in Examples 2-1 to 2-5 express high fluidity by heating. Therefore, by heating and melting at the time of bonding, not only excellent followability to the uneven surface, but also one of the adherends does not cause bending in the vicinity of the step even if the material is low in rigidity such as a film, thereby obtaining a smooth laminate. Could. Furthermore, since the gel fraction of the hard part was 40% or more, a high cohesive force was expressed even under severe environmental tests such as high temperature and high humidity, and peeling, foaming and deformation were not generated, and a laminate having high reliability was obtained. .

Since the adhesive sheet of the comparative example 2-1 partially crosslinks the adhesive resin composition by ultraviolet irradiation, when laminating glass and a film with a printing step, irregularities due to the printing step are transferred to the film side and the smooth laminate Couldn't get it. Moreover, foaming was seen under the high temperature, high humidity test by the distortion of the adhesive material of step vicinity, and storage stability was inferior.

Comparative Example 2-2 is a hot-melt type adhesive sheet using an adhesive resin composition having some rigidity in a room temperature region without using a (meth) acrylic copolymer.

The sheet | seat of the comparative example 2-2 had very low tackiness in room temperature vicinity compared with the adhesive sheet of an Example. When laminating glass and a sheet with a printing step, the fluidity at the time of heating was low, so that irregularities due to the printing step were slightly transferred to the sheet side, resulting in a decrease in the smoothness of the laminate compared with the adhesive sheet of the example. In addition, as can be seen from the point that the Asuka hardness at the light opaque point is high, since the rigidity of the sheet is high at the time of pasting work and does not have self-adhesion, from the stage of positioning when pasting The adherend needs to be preheated, and there is also a problem that the work is more complicated than the pressure-sensitive adhesive sheet that can be attached at normal temperature only by pressing.

In Comparative Example 2-3, since the crosslinking reaction of the adhesive resin composition of the adhesive sheet 2-7 is already completed, the soft part whose gel fraction is 1% or less does not exist in an adhesive sheet, The irregularities were not transferred to obtain a smooth laminate, and in the vicinity of the corner portion where the printing step intersected, some adhesives were not completely filled and bubbles were left.

The photocurable transparent double-sided adhesive sheet containing a (meth) acrylic copolymer having a soft part having a gel fraction of less than 1% and a hard part having a gel fraction of 40% or more from the results of the above examples and the test results conducted by the inventors up to now. If it is used, it can be considered that like the embodiment, two structural member for image display apparatus can be adhere | attached suitably.

Moreover, it is preferable that the gel fraction of a soft part in an adhesive sheet surface is less than 1%, and it is preferable that the gel fraction of a hard part is 40% or more.

Moreover, it is preferable that the glass transition temperature (actual Tg) of a soft part in an adhesive sheet surface is -70-10 degreeC, and the glass transition temperature (actual Tg) of a hard part is -60- + 20 degreeC, and the glass transition temperature of a hard part It can be considered that it is preferable that the difference (Tg [H] -Tg [S]) between (Tg [H]) and the glass transition temperature (Tg [S]) of the soft portion is 3 ° C or more.

Example 2-6

With respect to the adhesive sheet X1 produced in Example 2-1, a long rolled sheet having a width of 150 mm and a length of 100 m was made of a plastic roll of 6 inches in diameter with an initial winding tension of 70 N and a taper rate of 20%. It wound up in the core and produced the adhesive sheet roll.

The high pressure mercury lamp was used to irradiate light so that the accumulated amount of light with a wavelength of 365 nm might reach 500 mJ / cm <2> and photocured the end surface part, and it was set as the adhesive sheet roll which has a hard part at the end surface part of the produced sheet roll.

[Comparative Example 2-4]

Except not having irradiated light, it carried out similarly to Example 2-6, and produced the adhesive sheet roll.

40 degreeC 90% RH constant temperature with respect to the adhesive sheet roll of the comparative example 2-4 only in the soft part which does not have a hard part produced in this way, and the adhesive sheet roll of Example 2-6 which has a hard part in a cross section. After storing for two weeks in a humidity chamber, the end surface of the adhesive sheet roll was visually observed.

The adhesive sheet roll of Example 2-5 which has a hard part at the end surface part is comparative example 2- which consists only of a soft part, compared with the thing which pulled out from the end part part and the unwinding workability of the sheet was favorable. As the cross section of the PSA sheet roll 4 was pulled out, the cross section was sticky, resulting in a problem in the unwinding operation.

Example 3-1

As a (meth) acrylic-type copolymer (3-A), 15 mass parts (18 mol%) of polymethyl methacrylate macromonomers (Tg: 105 degreeC, number average molecular weight 2400) and butyl acrylate (Tg: -55 degreeC) A graft copolymer (3-A1) formed by random copolymerization of 81 parts by mass (75 mol%) and 4 parts by mass (7 mol%) of acrylic acid (Tg: 106 DEG C) was used.

In this graft copolymer (3-A1), the glass transition temperature of the copolymer constituting the stem component is -60 ° C, and the content in the graft copolymer (3-A1) of the macromonomer is 15% by mass, and the temperature is 130 ° C. , The complex viscosity at a frequency of 0.02 Hz was 260 Pa · s.

1 kg of this graft copolymer (3-A1), 90 g of glycerin dimethacrylate (manufactured by Nichi Corporation, product name: GMR) as the crosslinking agent (3-B), and 2,4,6- as the photopolymerization initiator (3-C) 15 g of a mixture of Trimethylbenzophenone and 4-methylbenzophenone (manufactured by Lanberti, product name: Ezacure TZT) was uniformly mixed to prepare an adhesive resin composition 3-1.

Two release films, ie, two polyethylene terephthalate films ("Dia foil MRV-V06" made by Mitsubishi Jushi Co., Ltd., thickness 100 micrometers / "Dia foil MRQ" by Mitsubishi Jushi Co., Ltd.) to which the said adhesive resin composition 3-1 was peeled off, It sandwiched between 75 micrometers in thickness, it shape | molded in sheet form so that it might become 150 micrometers in thickness using the laminator, and the adhesive sheet 3-1 (thickness 150micrometer) was created.

Example 3-2

Adhesive resin composition 3 in the same manner as in Example 3-1, except that 90 g of glycerin dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: NK ester 701) (3-B-1) was used as the crosslinking agent (3-B). -2 was produced.

The adhesive sheet 3-2 (thickness 150 micrometers) was created like Example 3-1 using the said adhesive resin composition 3-2.

Example 3-3

1 kg of the same graft copolymer (3-A1) as in Example 3-1, 90 g of glycerin dimethacrylate (manufactured by Nichi Corporation, product name: GMR) as a crosslinking agent (3-B), and a photopolymerization initiator (3-C) 15 g of a mixture of 2,4,6-trimethylbenzophenone and 4-methylbenzophenone (manufactured by Lanberti, product name: Ezacure TZT), and 50 g of an ultraviolet light stabilizer (Tiba123, product name: TIN123) were uniformly mixed to form an adhesive. Resin composition 3-3 was produced.

And using the adhesive resin composition 3-3, the adhesive sheet 3-3 (thickness 150 micrometers) was created like Example 3-1.

Example 3-4

As a (meth) acrylic-type copolymer (3-A), 10 mass parts (12 mol%) of polymethyl methacrylate macromonomers (Tg: 105 degreeC, number average molecular weight 2500) and butyl acrylate (Tg: -55 degreeC) A graft copolymer (3-A2) obtained by random copolymerization of 88 parts by mass (84 mol%) and 2 parts by mass (7 mol%) of acrylic acid (Tg: 106 DEG C) was used.

In this graft copolymer (3-A2), the glass transition temperature of the copolymer constituting the stem component is -60 ° C, and the content in the graft copolymer (3-A2) of the macromonomer is 10% by mass, and the temperature is 130 ° C. , The complex viscosity at a frequency of 0.02 Hz was 240 Pa · s.

1 g of this graft copolymer (3-A2), 50 g of trimethylolpropane triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: CLM400) as a crosslinking agent (3-B), and 2,4 as a photopolymerization initiator (3-C) 15 g of a mixture of 6-trimethylbenzophenone and 4-methylbenzophenone (manufactured by Lanberti, product name: Ezacure TZT) was uniformly mixed to prepare an adhesive resin composition 3-4.

And using the adhesive resin composition 3-4, the adhesive sheet 3-4 (thickness 150 micrometers) was created like Example 3-1.

Example 3-5

As a (meth) acrylic-type copolymer (3-A), 8 mass parts (10 mol%) of polymethyl methacrylate macromonomers (Tg: 105 degreeC, number average molecular weight 2500) and butyl acrylate (Tg: -55 degreeC) A graft copolymer (3-A3) formed by random copolymerization of 89 parts by mass (85 mol%) and 3 parts by mass (5 mol%) of acrylic acid (Tg: 106 DEG C) was used.

In this graft copolymer (3-A3), the glass transition temperature of the copolymer constituting the stem component is -40 ° C, and the content in the graft copolymer (3-A3) of the macromonomer is 8% by mass, and the temperature is 130 ° C. , The complex viscosity at a frequency of 0.02 Hz was 220 Pa · s.

1 kg of this graft copolymer (3-A3), 90 g of glycerin dimethacrylate (manufactured by Nichi Corporation, product name: GMR) as the crosslinking agent (3-B), and 2,4,6- as the photopolymerization initiator (3-C) 15 g of a mixture of trimethylbenzophenone and 4-methylbenzophenone (manufactured by Lanberti, product name: Ezacure TZT) was uniformly mixed to prepare pressure-sensitive adhesive resin composition 3-5.

And using this adhesive resin composition 3-5, the adhesive sheet 3-5 (thickness 150 micrometers) was created like Example 3-1.

Comparative Example 3-1

It produced so that it corresponds to the Example of international publication 2012/032995.

That is, as a (meth) acrylic copolymer (3-A), 75 mass parts (57 mol%) of 2-ethylhexyl acrylate (Tg: -70 degreeC) and 20 mass parts (33 mol%) of vinyl acetate (Tg: 32 degreeC) ) And 1 mass of acrylic copolymer (3-A-5) formed by random copolymerization of 5 parts by mass (10 mol%) of acrylic acid (Tg: 106 ° C) as a crosslinking agent (3-B) as trimethylolpropanetriacrylate (3 -B-4) As 200 g and photoinitiator (3-C), 10 g of 4-methylbenzophenone (3-C-3) was mixed and added to prepare the resin composition for intermediate | middle layers.

The resin composition for intermediate | middle layers was sandwiched between two polyethylene terephthalate films (Panacox agent, NP75Z01, 75 micrometers in thickness / Toyo spinning company made, E7006, 38 micrometers in thickness) which peeled, so that it might be set to 80 micrometers in thickness. It shape | molded in the sheet form and created the sheet | seat ((alpha)) for intermediate | middle layers.

Then, 20 g of 4-methylbenzophenone (3-C-3) is added and mixed as a photoinitiator (3-C) with respect to 1 kg of the said acrylic copolymer (3-A-5), and the resin composition for adhesive layers is It prepared.

The said resin composition for adhesive layers was made into two release films, ie, two polyethylene terephthalate films ("Diafoil MRA" by Mitsubishi Jushi Co., Ltd. thickness, 75 micrometers / "E7006" by Toyo spinning company, 38 micrometers in thickness). It sandwiched in between, it shape | mold in sheet form so that it might become thickness of 35 micrometers, and created the resin sheet (beta) for adhesive layers.

Furthermore, the resin composition for adhesive layers was sandwiched between two polyethylene terephthalate films (Mitsubishi Jushi Co., Ltd., diafoil MRF, thickness 75 micrometers / toy spinning company made, E7006, thickness 38 micrometers) which carried out the peeling process, and thickness 35 It molded in the sheet form so that it might become micrometer, and the resin sheet (beta ') for adhesive layers was created.

While peeling and removing the PET film of both sides of the intermediate | middle layer sheet ((alpha)) sequentially, the PET film of one side of the adhesive sheets ((beta)) and ((beta ')) is peeled off, and the exposed adhesive surface was made into the intermediate | middle layer sheet ((alpha)). The two-sided adhesive sheet which consists of ((beta)) / ((alpha)) / ((beta ')) was sequentially bonded together to both surfaces of the.

Via a PET film remaining on the surfaces of (β) and (β '), ultraviolet rays are irradiated with a high pressure mercury lamp so that the amount of accumulated light having a wavelength of 365 nm is 1000 mJ / cm 2, and (α), (β) and (β'). ) Was crosslinked with ultraviolet rays to prepare an adhesive sheet 3-6 (thickness: 150 µm).

Comparative Example 3-2

The adhesive sheet was produced according to Example 6 of WO2010 / 038366.

That is, 650 g of phenoxy resin (manufactured by InChem, PKHH, weight average molecular weight of 5.2 million) as a replacement for the (meth) acrylic copolymer (3-A) and a polycarbonate having a carbonate skeleton as a replacement of the crosslinking agent (3-B) Pressure-sensitive adhesive resin composition 3 obtained by uniformly mixing 43 g of 1-cyclohexylphenyl ketone (manufactured by BASF, Irgacure184) as a urethane acrylate (manufactured by Negami Industry Co., UN5500, weight average molecular weight of 6.7 million) and a photopolymerization initiator (3-C) -7 was produced.

The said composition 3-7 produced the adhesive sheet 3-7 (thickness 150 micrometers) by the method similar to Example 3-1.

[evaluation]

The adhesive sheet and laminated body which were produced by the Example and the comparative example were evaluated as follows.

Tensile Modulus, Breaking Strength, Breaking Elongation

The adhesive sheets 3-1 to 3-7 were cut out to width 20mm, and it was set as the tensile test measurement sample before optical crosslinking.

After cutting the adhesive sheets 3-1 to 3-7 to 20 mm in width, the adhesive sheet was cured by irradiating ultraviolet rays using a high pressure mercury lamp from the release PET side so that the accumulated light amount at 365 nm was 2000 mJ / cm 2, It cured at 23 degreeC 50% RH for 15 hours, and it was set as the tensile test measurement sample after photocrosslinking.

Tensile modulus, tensile strength at break, and tensile strength at break were measured at the test rate of 300 mm / min in the tensile test measurement sample at an environment of 23 ° C. 50% RH.

In addition, the measurement conditions of the tensile elasticity modulus were 30-50 mm in displacement.

(Gel fraction)

The following measurement was performed about taking out the part which contact | connects the light transmission part of the adhesive sheets 3-1 to 3-7 produced by the Example and the comparative example, respectively, the part which contact | connects the light impermeable part, or soft part, respectively. .

1) The pressure-sensitive adhesive resin composition is weighed (W1) and wrapped in a 200 mesh SUS mesh W0 weighed in advance.

2) The SUS mesh is immersed in 100 mL of ethyl acetate for 24 hours.

3) The SUS mesh is taken out and dried at 75 ° C. for 4 hours and a half.

4) The weight (W2) after drying is calculated | required, and the gel fraction of an adhesive resin composition is measured from the following formula.

Gel fraction (%) = 100Σ (W2-W0) / W1

(Workability (storability))

The laminated sheets were produced by sandwiching the adhesive sheets 3-1 to 3-7 cut | disconnected by 50 mm x 50 mm widthwise between two glass plates of thickness 2mm in 100 mm x 100 mm square. The 500-g weight was put on the laminated body, and visual observation was performed whether the adhesive came out of the laminated body after leaving for 24 hours in 60 degreeC environment.

The produced laminated body was visually observed, and it was determined that "(x)" that the adhesive was pushed out as a whole, "(triangle | delta)" that the adhesive was pushed out only at the edge part and "(circle)" that the adhesive was not pushed out.

(Step absorbency)

The adhesive sheets 3-1 to 3-6 in the state before light irradiation produced in Examples 3-1 to 3-5 and Comparative Example 3-1 were cut out to 50 mm x 80 mm, and one release film was peeled off and exposed. The pressure-sensitive adhesive side was pressed onto the printing surface of soda lime glass (82 mm x 53 mm x 0.5 mm thickness), which was printed on the periphery of 3 mm with a thickness of 80 µm, so that the four sides of the adhesive material were caught in the printing step. It crimped | bonded (absolute pressure 5 kPa, temperature 80 degreeC, press pressure 0.04 MPa). Subsequently, the remaining release film was peeled off, and after press-gluing a zeanoa film (Nippon Xeon company make, 100 micrometer thickness), autoclave treatment (80 degreeC, gauge pressure 0.2MPa, 20 minutes) was performed and the final sticking was carried out.

Next, from the soda-lime glass side which printed, the ultraviolet-ray is irradiated with a high pressure mercury lamp so that the ultraviolet-ray of wavelength 365nm may reach | attain 2000mJ / cm <2> to the sheet | seat X, and the point which contact | connects the opening which is not printed, ie, the light transmission part, is made. Sheet was cured to prepare laminates 3-1 to 3-6 for evaluation.

About the adhesive sheet 3-7 created by the comparative example 3-2, the lamination | stacking of the soda lime glass and the zeoa film (100 micrometers thickness made by Nippon Zeon) which printed in the same procedure as the above using the adhesive sheet 3-7 After the sieve was prepared, autoclave treatment (80 ° C., gauge pressure of 0.2 MPa, 20 minutes) was performed, and the final bonding was carried out to obtain laminate 3-7 for evaluation.

The produced laminates 3-1 to 3-7 were visually observed, and the "x" and the film were bent in the vicinity of the step and the irregularities caused by the distortion were seen in the vicinity of the printing step without the adhesive material following the step of printing. "△" and the thing bonded together smoothly without bubbles were determined as "(circle)".

In the adhesive sheets produced in Examples 3-1 to 3-5, the tensile properties were greatly changed before and after photocuring. Since it has such a characteristic, it was confirmed that the adhesive sheets produced in Examples 3-1 to 3-5 have the outstanding level | step difference absorption property before photocuring, but can have the outstanding foaming resistance after photocuring.

On the other hand, in the comparative example, since the change of the tensile characteristic before and after photocuring was inadequate, since the change after photocrosslinking was inadequate in the comparative example 3-1, it became a sheet with low reliability, and in the comparative example 3-2, the optical crosslinking It became the sheet which workability (storability) was inferior before.

Claims (16)

A pressure-sensitive adhesive sheet before photocuring formed of a resin composition containing a (meth) acrylic copolymer (A), a crosslinking agent (B) and a photopolymerization initiator (C), having photocurability, and further comprising the following (1) and (2) With the characteristics of
The said (meth) acrylic-type copolymer (A) is a graft copolymer provided with the macromonomer as a branch component, The adhesive sheet characterized by the above-mentioned.
(1) In 0-40 degreeC, shape retention can be performed and self-adhesiveness is shown.
(2) In 70-100 degreeC, a viscosity shows 100-3000 Pa.s. The method of claim 1,
The stem component of the said graft copolymer contains a hydrophobic (meth) acrylate monomer and a hydrophilic (meth) acrylate monomer as a structural unit, The adhesive sheet characterized by the above-mentioned. A pressure-sensitive adhesive sheet before photocuring formed of a resin composition containing a (meth) acrylic copolymer (A), a crosslinking agent (B) and a photopolymerization initiator (C), having photocurability, and further comprising the following (1) and (2) With the characteristics of
The said (meth) acrylic-type copolymer (A) has monomer a1 whose glass transition temperature (Tg) is less than 0 degreeC, monomer a2 whose glass transition temperature (Tg) is 0 degreeC or more and less than 80 degreeC, and glass transition temperature (Tg) The monomer a3 which is 80 degreeC or more copolymerizes in the molar ratio of a1: a2: a3 = 10-40: 90-35: 0-25, and is a (meth) acrylic-type copolymer whose weight average molecular weights are 50000-400000. The adhesive sheet characterized by the above-mentioned.
(1) In 0-40 degreeC, shape retention can be performed and self-adhesiveness is shown.
(2) In 70-100 degreeC, a viscosity shows 100-3000 Pa.s. The method of claim 1,
Furthermore, it has the characteristic of following (3) after photocuring, The adhesive sheet characterized by the above-mentioned.
(3) The viscosity in 70-100 degreeC is 3000-50000 Pa.s. A pressure-sensitive adhesive sheet containing a (meth) acrylic copolymer (A) and photocured, the pressure-sensitive adhesive sheet having a sheet portion having a gel fraction of less than 1% and a sheet portion having a gel fraction of 40% or more in the adhesive sheet. . The method of claim 5, wherein
The sheet portion having a gel fraction of less than 1% has a glass transition temperature (Tg [H]) of -70 to -10 ° C measured by a differential scanning calorimeter (DSC), and the sheet portion having a gel fraction of 40% or more is a differential scanning calorimeter. The difference between the glass transition temperature (Tg [S]) measured by (DSC) of -60 to + 20 ° C and the glass transition temperature of the sheet portion having a gel fraction of 40% or more and the glass transition temperature of the sheet portion having a gel fraction of less than 1%. The adhesive sheet whose (Tg [H] -Tg [S]) is 3 degreeC or more. The method of claim 5, wherein
The adhesive sheet formed by partially photocuring the sheet | seat formed from the resin composition containing a (meth) acrylic-type copolymer (A), a crosslinking agent (B), and a photoinitiator (C). The method of claim 5, wherein
The said (meth) acrylic-type copolymer (A) is a graft copolymer provided with the macromonomer as a branch component, The adhesive sheet characterized by the above-mentioned. The method of claim 5, wherein
The said (meth) acrylic-type copolymer (A) has monomer a1 whose glass transition temperature (Tg) is less than 0 degreeC, monomer a2 whose glass transition temperature (Tg) is 0 degreeC or more and less than 80 degreeC, and glass transition temperature (Tg) The monomer a3 which is 80 degreeC or more copolymerizes in the molar ratio of a1: a2: a3 = 10-40: 90-35: 0-25, and is a (meth) acrylic-type copolymer whose weight average molecular weights are 50000-400000. The adhesive sheet characterized by the above-mentioned. The method of claim 5, wherein
The adhesive sheet which has the sheet part whose gel fraction is less than 1%, and the sheet part whose gel fraction is 40% or more in the sheet surface of an adhesive sheet. As an adhesive sheet which consists of a resin composition containing 100 mass parts of (meth) acrylic-type copolymers (A), 0.5-20 mass parts of crosslinking agents (B), and 0.1-5 mass parts of photoinitiators (C),
Ratio (X ₁ / X ₂₎ of the tensile modulus before the photo-crosslinking (X ₁₎ and tensile modulus (X ₂₎ after photo-crosslinking is more than 3,
The said (meth) acrylic-type copolymer (A) is a graft copolymer provided with a macromonomer as a branch component, Comprising: The adhesive sheet characterized by containing the said macromonomer in the ratio of 5-30 mass%. The method of claim 11,
The stem component of the said graft copolymer contains a hydrophobic (meth) acrylate monomer and a hydrophilic (meth) acrylate monomer as a structural unit, The adhesive sheet characterized by the above-mentioned. The adhesive sheet laminated body provided with the structure which laminates the adhesive sheet in any one of Claims 1-12, and a release film. The laminated body for image display apparatus structures provided with the structure formed by laminating | stacking the two component display elements for image display apparatuses through the adhesive sheet in any one of Claims 1-12. The method of claim 14,
The said member for image display apparatus is a laminated body which consists of any 1 type, or 2 or more types of combinations of the group which consists of a touch panel, an image display panel, a surface protection panel, and a polarizing film, The laminated body for image display device components characterized by the above-mentioned. The image display apparatus comprised using the laminated body for image display apparatus structures of Claim 14.

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