JP2021050353A - Adhesive sheet, display body, and method of manufacturing display body - Google Patents

Abstract

To provide an adhesive sheet capable of improving designability of a display body, and a display body improved in designability.SOLUTION: An adhesive sheet 1 includes a colored adhesive layer 11 for bonding one display body constituent member 21 and another display body constituent member 22 together. The colored adhesive layer 11 comprises an active energy ray-curable colored adhesive and has a haze value of 80% or less and a lightness L* defined by the CIE 1976 L*a*b* color system of 95 or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to an adhesive sheet used for laminating display body constituent members, a display body using the adhesive sheet, and a method for manufacturing the display body.

Recent display bodies (displays), for example, in-vehicle displays in automobile instrument panels, car navigation systems, various instruments provided in consoles, display bodies such as tablet terminals for general users, commercial tablets A liquid crystal display device is often used in a display body such as a terminal or a digital signage, or a display body such as an outdoor digital signage.

As described above, in a display body for in-vehicle use or the like, when the display body is turned off, it is required to give a sense of unity with peripheral members of the display body, for example, a frame material, and improve the design. Sometimes. For that purpose, it is conceivable to color the display body. For example, Patent Documents 1 to 4 disclose inventions relating to coloring the display body.

Japanese Unexamined Patent Publication No. 2000-313871 Japanese Unexamined Patent Publication No. 2009-188298 Japanese Unexamined Patent Publication No. 2012-234028 JP-A-2017-57375

However, since the techniques disclosed in Patent Documents 1 to 4 have different purposes of coloring, it is not possible to give the display body a sense of unity with the peripheral members and improve the design.

The present invention has been made in view of the above-mentioned actual conditions, and an object of the present invention is to provide an adhesive sheet capable of improving the design of a display body and a display body having an improved design.

In order to achieve the above object, first, the present invention is an adhesive sheet provided with an adhesive layer for adhering one display body constituent member and another display body constituent member, and the adhesive. The agent layer is composed of an active energy ray-curable pressure-sensitive adhesive containing a colorant, the total light transmittance of the pressure-sensitive adhesive layer is 3% or more, and the CIE1976L * a * b * color system of the pressure-sensitive adhesive layer. Provided is an pressure-sensitive adhesive sheet having a brightness L * defined by the above (Invention 1).

According to the above invention (Invention 1), when applied to a display body, the design property (appearance harmony as an example) of the display body can be improved. For example, when the display body is turned off, the display body can be given a sense of unity with a peripheral member, for example, a black frame material, thereby enhancing the appearance harmony and giving a high-class feeling. It becomes. Further, by having the above-mentioned total light transmittance, visibility as a display body can be ensured.

In the above invention (Invention 1), the haze value of the pressure-sensitive adhesive layer is preferably 0.01% or more and 80% or less (Invention 2).

In the above inventions (Inventions 1 and 2), the colorant is preferably a black pigment or dye (Invention 3).

In the above inventions (Inventions 1 to 3), the following formula (I) can be satisfied when the content of the colorant in the pressure-sensitive adhesive is X% by mass and the thickness of the pressure-sensitive adhesive layer is Z μm. Preferred (Invention 4).
5 ≦ X × Z <300 ・ ・ ・ (I)

In the above inventions (Inventions 1 to 4), the content of the colorant in the active energy ray-curable pressure-sensitive adhesive is preferably 0.01% by mass or more and 2.0% by mass or less (Invention 5). ).

In the above inventions (Inventions 1 to 5), the pressure-sensitive adhesive is preferably an acrylic pressure-sensitive adhesive (Invention 6).

In the above inventions (Inventions 1 to 6), the pressure-sensitive adhesive comprises a (meth) acrylic acid ester polymer (A), a cross-linking agent (B), an active energy ray-curable component (C), and a colorant (D). It is preferable that the sticky composition contained therein is crosslinked (Invention 7).

In the above inventions (Inventions 1 to 7), it is preferable to provide two release sheets and the pressure-sensitive adhesive layer sandwiched between the release sheets so as to be in contact with the release surfaces of the two release sheets (invention). 8).

Secondly, the present invention comprises a cured pressure-sensitive adhesive layer that adheres one display body component, another display body component, and the one display body component and the other display body component to each other. The post-curing pressure-sensitive adhesive layer is a post-curing pressure-sensitive adhesive layer obtained by subjecting the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet (Inventions 1 to 8) to active energy ray-curing. (Invention 9).

In the above invention (Invention 9), at least one of the display body constituent member and the other display body constituent member may have a step on the surface on the side to be bonded by the adhesive layer after curing. Preferred (Invention 10).

In the above inventions (Inventions 9 and 10), it is preferable to have a black frame material (Invention 11).

Thirdly, in the present invention, a laminated body formed by laminating one display body constituent member and another display body constituent member via the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet (Invention 1 to 8) is produced. Provided is a method for producing a display body, which comprises irradiating the pressure-sensitive adhesive layer of the laminated body with active energy rays and curing the pressure-sensitive adhesive layer to form a pressure-sensitive adhesive layer after curing (Invention 12). ..

According to the adhesive sheet according to the present invention, the design of the display body can be improved. In addition, the display body according to the present invention has improved design.

It is sectional drawing of the pressure-sensitive adhesive sheet which concerns on one Embodiment of this invention. It is sectional drawing of the display body which concerns on one Embodiment of this invention. It is a top view of the display body which has a frame material which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
[Adhesive sheet]
The pressure-sensitive adhesive sheet according to an embodiment of the present invention includes a pressure-sensitive adhesive layer for adhering one display body component and another display body component, preferably one side of the pressure-sensitive adhesive layer. Alternatively, release sheets are laminated on both sides. The display body and the display body constituent members will be described later.

FIG. 1 shows a specific configuration as an example of the pressure-sensitive adhesive sheet according to the present embodiment.
As shown in FIG. 1, the adhesive sheet 1 is sandwiched between the two release sheets 12a and 12b and the two release sheets 12a and 12b so as to be in contact with the release surfaces of the two release sheets 12a and 12b. It is composed of a pressure-sensitive adhesive layer 11. The peeling surface of the release sheet in the present specification means a surface of the release sheet that has peelability, and includes both a surface that has been peeled and a surface that exhibits peelability without peeling. ..

1. 1. Each member 1-1. Adhesive layer The adhesive layer 11 of the adhesive sheet 1 according to the present embodiment is made of an active energy ray-curable adhesive containing a colorant. The total light transmittance of the pressure-sensitive adhesive layer 11 (value measured in accordance with JIS K7361-1: 1997) is 3% or more, which is defined by the CIE1976L * a * b * color system of the pressure-sensitive adhesive layer 11. The brightness L * to be obtained is 95 or less. The method for measuring the brightness L * in the present specification is as shown in a test example described later.

When the pressure-sensitive adhesive layer 11 satisfying the above physical properties is applied to a display body, the design property (appearance harmony as an example) of the display body can be improved when the display body is turned off. Specifically, it is possible to give the display body a sense of unity with a peripheral member, for example, a black frame material, thereby enhancing the appearance harmony and giving a high-class feeling. Further, when the total light transmittance is 3% or more, the visibility as a display body can be ensured.

Specifically, as the peripheral members, the brightness L * defined by the CIE1976L * a * b * color system is 23.2, the chromaticity a * is -0.5, and the chromaticity b * is -1. The dashboard of the automobile which is No. 5 can be mentioned. As for the color tones of the peripheral members, it is preferable that the lightness L * is 5 to 95, the chromaticity a * is -40 to 40, and the chromaticity b * is -40 to 40, and in particular, the lightness L *. Is 10 to 80, the chromaticity a * is -30 to 30, the chromaticity b * is preferably -30 to 30, and the lightness L * is 15 to 70, and the chromaticity a *. Is preferably -20 to 20, and the chromaticity b * is preferably -20 to 20. The pressure-sensitive adhesive sheet 1 according to the present embodiment can be suitably used for a display body having the peripheral member having the above-mentioned color.

From the viewpoint of visibility as a display body, the total light transmittance of the pressure-sensitive adhesive layer 11 is 3% or more, preferably 10% or more, particularly preferably 25% or more, and further preferably 50% or more. Is. The upper limit of the total light transmittance is not particularly limited, but is usually 100% or less, and in consideration of the relationship with the brightness L *, it is preferably 98% or less, and particularly preferably 95% or less. Further, it is preferably 90% or less.

Further, from the viewpoint of improving the design due to the appearance harmony, the lightness L * of the pressure-sensitive adhesive layer 11 is 95 or less, preferably 92 or less, particularly preferably 89 or less, and further preferably 86 or less. .. On the other hand, from the viewpoint of improving the design due to the appearance harmony and the visibility of the display body, the lower limit of the brightness L * is preferably 10 or more, more preferably 20 or more, and particularly 30 or more. It is preferable, more preferably 40 or more, and most preferably 55 or more.

Further, the chromaticity a * defined by the CIE1976L * a * b * color system of the pressure-sensitive adhesive layer 11 is preferably -40 or more, more preferably -30 or more, and particularly -20 or more. It is preferably -15 or more, and most preferably -10 or more. Further, the chromaticity a * is preferably 40 or less, more preferably 30 or less, particularly preferably 20 or less, further preferably 15 or less, and 10 or less. Is the most preferable. When the chromaticity a * is in the above range, the designability, particularly the designability (particularly the appearance harmony) in the vehicle-mounted display body is further improved.

Further, the chromaticity b * defined by the CIE1976L * a * b * color system of the pressure-sensitive adhesive layer 11 is preferably -40 or more, more preferably -30 or more, and particularly -20 or more. It is preferably -15 or more, and most preferably -10 or more. Further, the chromaticity b * is preferably 40 or less, more preferably 30 or less, particularly preferably 20 or less, further preferably 15 or less, and 10 or less. Is the most preferable. When the chromaticity b * is in the above range, the designability, particularly the designability (particularly the appearance harmony) in the vehicle-mounted display body is further improved.

The haze value of the pressure-sensitive adhesive layer 11 is usually 0% or more, and when the colorant in the pressure-sensitive adhesive layer 11 is a dye, it is preferably 0.01% or more, preferably 0.05% or more. Is more preferable, and particularly preferably 0.1% or more. When the colorant in the pressure-sensitive adhesive layer 11 is a pigment, the haze value of the pressure-sensitive adhesive layer 11 is preferably 0.1% or more, more preferably 1% or more, and 6% or more. It is particularly preferable to be present, and most preferably 12% or more. When the lower limit of the haze value of the pressure-sensitive adhesive layer 11 is the above, it becomes easier to impart a sense of unity with the peripheral member (for example, the frame material) to the obtained display body. On the other hand, the haze value of the pressure-sensitive adhesive layer 11 is preferably 80% or less, more preferably 70 or less, particularly preferably 60% or less, and further preferably 50% or less. Most preferably, it is 40% or less. Since the upper limit of the haze value of the pressure-sensitive adhesive layer 11 is the above, the total light transmittance is likely to fall within the above range, and the obtained display body has a sense of unity with the peripheral member (for example, the frame material). It becomes easier to give. The haze value in the present specification is a value measured according to JIS K7136: 2000.

The total light transmittance, haze value, lightness L *, chromaticity a *, and chromaticity b * of the pressure-sensitive adhesive layer 11 were obtained by curing the pressure-sensitive adhesive layer 11 by irradiation with active energy rays to obtain a cured pressure-sensitive adhesive layer. After that, there is almost no change.

For the above-mentioned total light transmittance and lightness L * (furthermore, chromaticity a * and b *, and haze value), the type and content of the colorant contained in the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 11 are appropriately selected. By doing so, it is possible to achieve this.

The colorant may be a pigment or a dye. The pigment may be an inorganic pigment or an organic pigment. From the viewpoint of durability (particularly blister resistance) of the obtained pressure-sensitive adhesive, inorganic pigments are preferable. The color of the colorant can be appropriately selected according to the color of the peripheral member for which a sense of unity is desired, but in general, it may be a dark color or a dark color such as black, brown, navy blue, purple, or blue. It is preferable, and black is particularly preferable.

Examples of inorganic pigments include carbon black, cobalt pigments, iron pigments, chromium pigments, titanium pigments, vanadium pigments, zirconium pigments, molybdenum pigments, ruthenium pigments, platinum pigments, and ITO (indium). Examples thereof include tin oxide) dyes and ATO (antimons tin oxide) dyes.

Examples of organic pigments and organic dyes include aminium pigments, cyanine pigments, merocyanine pigments, croconium pigments, squalium pigments, azulenium pigments, polymethine pigments, naphthoquinone pigments, and pyririum pigments. Phthalocyanin pigments, naphthalocyanine pigments, naphtholactum pigments, azo pigments, condensed azo pigments, indigo pigments, perinone pigments, perylene pigments, dioxazine pigments, quinacridone pigments, isoindolinone pigments, quinophthalones Dyes, pyrrole dyes, thioindigo dyes, metal complex dyes (metal complex salt dyes), dithiol metal complex dyes, indolphenol dyes, triallylmethane dyes, anthraquinone dyes, dioxazine dyes, naphthol dyes, azomethine Examples thereof include pigments, benzimidazolone pigments, pyranthron pigments and slene colors.

Examples of the black pigment include carbon black, copper oxide, iron tetraoxide, manganese dioxide, aniline black, activated charcoal and the like. Examples of the black dye include high-concentration vegetable dyes and azo dyes.

The above pigments or dyes can be appropriately mixed and used so that the desired physical properties can be obtained in the pressure-sensitive adhesive layer 11.

Among the above-mentioned colorants, carbon black, niglosin-based black dye and chromium acid are easy to achieve the above-mentioned total light transmittance and lightness L * (further haze value) and to give a sense of unity with peripheral members. Salt-based black dyes are preferred. The surface of the carbon black may or may not be subjected to a predetermined treatment (for example, a solvent-containing treatment).

The content X mass% of the colorant in the pressure-sensitive adhesive is preferably a value that satisfies the following formula (I) when the thickness of the pressure-sensitive adhesive layer 11 is Z μm.
5 ≦ X × Z <300 ・ ・ ・ (I)
When the value of X × Z is in the above range, the above-mentioned total light transmittance and brightness L * (further haze value) can be easily achieved. The thickness of the pressure-sensitive adhesive layer 11 in the present specification is a value measured according to JIS K7130.

From the above viewpoint, the lower limit of X × Z is preferably 8 or more, particularly preferably 10 or more, and further preferably 15 or more. The upper limit of X × Z is preferably 250 or less, more preferably 150 or less, particularly preferably 100 or less, and further 60 or less from the viewpoint of blister resistance. Is preferable, and 30 or less is most preferable.

In order to make it easier for the value of X × Z to fall within the above range, the content of the colorant (X mass%) in the pressure-sensitive adhesive is preferably 0.01 mass% or more as a lower limit value, and 0. It is more preferably 05% by mass or more, particularly preferably 0.1% by mass or more, and further preferably 0.12% by mass or more. The content (X% by mass) of the colorant is preferably 2.0% by mass or less, more preferably 1.0% by mass or less, and particularly 0.5% by mass or less, as an upper limit value. It is preferable that it is 0.2% by mass or less.

The type of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 1 according to the present embodiment is not particularly limited as long as it is active energy ray-curable, but has adhesive physical characteristics, optical properties, and durability (particularly blister resistance). ) And the like, an active energy ray-curable acrylic pressure-sensitive adhesive is preferable. The acrylic pressure-sensitive adhesive may be an emulsion type, a solvent type or a solvent-free type, and may be either a crosslinked type or a non-crosslinked type. Among them, a cross-linked acrylic pressure-sensitive adhesive having an active energy ray curability is preferable.

The pressure-sensitive adhesive has a pressure-sensitive composition containing, in particular, a (meth) acrylic acid ester polymer (A), a cross-linking agent (B), an active energy ray-curable component (C), and a colorant (D). It is preferably formed by cross-linking a substance (hereinafter, may be referred to as "adhesive composition P"). The colorant (D) is the colorant described above. The pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition P can exhibit excellent optical properties, adhesive strength, durability (step followability and blister resistance under high temperature and high humidity conditions) and the like. In addition, in this specification, (meth) acrylic acid means both acrylic acid and methacrylic acid. The same applies to other similar terms. In addition, the concept of "polymer" shall be included in "polymer".

(1) Ingredients of Adhesive Composition (1-1) (Meta) Acrylic Ester Polymer (A)
The (meth) acrylic acid ester polymer (A) in the present embodiment contains a reactive group-containing monomer having a reactive group in the molecule that reacts with the cross-linking agent (B) as a monomer unit constituting the polymer. Is preferable. The reactive group derived from this reactive group-containing monomer reacts with the cross-linking agent (B) to form a cross-linked structure (three-dimensional network structure), and a pressure-sensitive adhesive having a desired cohesive force can be obtained.

Examples of the reactive group-containing monomer include a monomer having a hydroxyl group in the molecule (hydroxyl group-containing monomer), a monomer having a carboxy group in the molecule (carboxy group-containing monomer), and a monomer having an amino group in the molecule (amino group-containing monomer). ) Etc. are preferably mentioned. Among these, a hydroxyl group-containing monomer and a carboxy group-containing monomer having excellent reactivity with the cross-linking agent (B) are preferable, and a hydroxyl group-containing monomer having less adverse effect on the adherend is particularly preferable.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and (meth). ) Hydroxyalkyl esters of (meth) acrylic acid such as 3-hydroxybutyl acrylate and 4-hydroxybutyl (meth) acrylic acid can be mentioned. Above all, from the viewpoint of the reactivity of the obtained (meth) acrylic acid ester polymer (A) with the cross-linking agent (B) of the hydroxyl group and the copolymerizability with other monomers, hydroxy having 1 to 4 carbon atoms A (meth) acrylic acid hydroxyalkyl ester having an alkyl group is preferable. Specifically, for example, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and the like are preferable, and 2-hydroxyethyl acrylate or 4-hydroxybutyl acrylate are particularly preferable. Be done. These may be used alone or in combination of two or more.

Examples of the carboxy group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. Of these, acrylic acid is preferable from the viewpoint of reactivity of the obtained (meth) acrylic acid ester polymer (A) with the cross-linking agent (B) of the carboxy group and copolymerizability with other monomers. These may be used alone or in combination of two or more.

Examples of the amino group-containing monomer include aminoethyl (meth) acrylate and n-butylaminoethyl (meth) acrylate. These may be used alone or in combination of two or more.

The (meth) acrylic acid ester polymer (A) preferably contains a reactive group-containing monomer as a lower limit value of 1% by mass or more, and particularly 5% by mass or more, as a monomer unit constituting the polymer. It is preferable that the content is 8% by mass or more, and when the reactive group-containing monomer is a hydroxyl group-containing monomer, it is particularly preferably contained in an amount of 15% by mass or more. Further, the (meth) acrylic acid ester polymer (A) preferably contains a reactive group-containing monomer as an upper limit value of 35% by mass or less, particularly 30% by mass or less, as a monomer unit constituting the polymer. It is preferably contained in an amount of 25% by mass or less, and when the reactive group-containing monomer is a carboxy group-containing monomer, it is preferably contained in an amount of 20% by mass or less and 12% by mass or less. Is particularly preferable. When the (meth) acrylic acid ester polymer (A) contains the reactive group-containing monomer in the above amount as the monomer unit, a good crosslinked structure is formed in the obtained pressure-sensitive adhesive, and a desired cohesive force can be obtained. Further, the dispersibility of the colorant (D) in the pressure-sensitive adhesive tends to be good, and the obtained pressure-sensitive adhesive has total light transmittance and lightness L * (further, chromaticity a * and b *, and haze value). The reproducibility and uniformity of the above are good, and excellent appearance harmony and character visibility are exhibited. Further, when the reactive group-containing monomer is a hydroxyl group-containing monomer, if the content is 15% by mass or more, a predetermined amount of hydroxyl groups remains in the pressure-sensitive adhesive. Hydroxyl groups are hydrophilic groups, and when such hydrophilic groups are present in a predetermined amount of the pressure-sensitive adhesive, even if the pressure-sensitive adhesive is placed under high-temperature and high-humidity conditions, it penetrates into the pressure-sensitive adhesive under the high-temperature and high-humidity conditions. It has good compatibility with the water content, and as a result, whitening of the adhesive when returned to normal temperature and humidity is suppressed (excellent in moisture-heat whitening resistance).

Further, it is also preferable that the (meth) acrylic acid ester polymer (A) does not contain a carboxy group-containing monomer as a monomer unit constituting the polymer. Since the carboxy group is an acid component, by not containing the carboxy group-containing monomer, the adhesive to which the adhesive is attached may have problems due to the acid, such as a transparent conductive film such as tin-doped indium oxide (ITO) or a metal film. Even if it exists, those defects (corrosion, change in resistance value, etc.) due to acid can be suppressed. However, it is permissible to contain a predetermined amount of the carboxy group-containing monomer so as not to cause such a problem. Specifically, in the (meth) acrylic acid ester polymer (A), the carboxy group-containing monomer is contained in an amount of 0.1% by mass or less, preferably 0.01% by mass or less, more preferably 0.001 as a monomer unit. It is permissible to contain in an amount of mass% or less.

The (meth) acrylic acid ester polymer (A) preferably contains a (meth) acrylic acid alkyl ester as a monomer unit constituting the polymer. Thereby, good adhesiveness can be exhibited. The alkyl group may be linear or branched chain.

As the (meth) acrylic acid alkyl ester, a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms is preferable from the viewpoint of adhesiveness. Examples of the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, propyl (meth) acrylic acid, and n- (meth) acrylic acid. Butyl, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-decyl (meth) acrylate, (meth) acrylate Examples thereof include n-dodecyl, myristyl (meth) acrylate, palmityl (meth) acrylate, and stearyl (meth) acrylate. Among them, (meth) acrylic acid ester having 1 to 8 carbon atoms of the alkyl group is preferable from the viewpoint of further improving the adhesiveness, and methyl (meth) acrylate, n-butyl (meth) acrylate or (meth) acrylic. 2-Ethylhexyl acrylate is particularly preferred, and methyl methacrylate, n-butyl acrylate or 2-ethylhexyl acrylate is even more preferred. These may be used alone or in combination of two or more.

The (meth) acrylic acid ester polymer (A) preferably contains (meth) acrylic acid alkyl ester in an amount of 40% by mass or more, and particularly 50% by mass or more, as a monomer unit constituting the polymer. It is preferable, and it is preferable that the content is 60% by mass or more. When the lower limit of the content of the (meth) acrylic acid alkyl ester is as described above, the (meth) acrylic acid ester polymer (A) can exhibit suitable tackiness. Further, the (meth) acrylic acid ester polymer (A) preferably contains 99% by mass or less of the (meth) acrylic acid alkyl ester as a monomer unit constituting the polymer, and particularly contains 95% by mass or less. It is preferable that the content is 90% by mass or less. When the upper limit of the content of the (meth) acrylic acid alkyl ester is as described above, a suitable amount of another monomer component such as a reactive functional group-containing monomer is introduced into the (meth) acrylic acid ester polymer (A). be able to.

The (meth) acrylic acid ester polymer (A) preferably contains a monomer having an alicyclic structure in the molecule (alicyclic structure-containing monomer) as a monomer unit constituting the polymer. Since the alicyclic structure-containing monomer is bulky, it is presumed that the presence of the monomer in the polymer widens the distance between the polymers, and the obtained pressure-sensitive adhesive can be made excellent in flexibility. .. As a result, the adhesive has excellent step followability.

The alicyclic structure carbon ring in the alicyclic structure-containing monomer may have a saturated structure or may have an unsaturated bond as a part. Further, the alicyclic structure may be a monocyclic alicyclic structure or a polycyclic alicyclic structure such as two rings or three rings. From the viewpoint of making the distance between the obtained (meth) acrylic acid ester polymers (A) appropriate and imparting high stress relaxation property to the pressure-sensitive adhesive, the alicyclic structure is a polycyclic alicyclic structure. Polycyclic structure) is preferable. Further, in consideration of the compatibility between the (meth) acrylic acid ester polymer (A) and other components, the polycyclic structure is particularly preferably bicyclic to tetracyclic. Further, from the viewpoint of imparting stress relaxation property as described above, the number of carbon atoms in the alicyclic structure (referring to the total number of carbon atoms in the portion forming the ring, and when a plurality of rings exist independently) , The total number of carbon atoms) is usually preferably 5 or more, and particularly preferably 7 or more. On the other hand, the upper limit of the number of carbon atoms in the alicyclic structure is not particularly limited, but from the viewpoint of compatibility as described above, it is preferably 15 or less, and particularly preferably 10 or less.

Specific examples of the alicyclic structure-containing monomer include cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, adamantyl (meth) acrylate, isobornyl (meth) acrylate, and (meth) acrylic. Dicyclopentenyl acid, dicyclopentenyloxyethyl (meth) acrylate, etc., among others, dicyclopentanyl (meth) acrylate (carbon number of alicyclic structure:) which exhibits better step followability: 10), adamantyl (meth) acrylate (carbon number of alicyclic structure: 10) or isobornyl (meth) acrylate (carbon number of carbon number of alicyclic structure: 7) is preferable, and isobornyl (meth) acrylate is particularly preferable. Further, isobornyl acrylate is preferable. These may be used individually by 1 type, and may be used in combination of 2 or more type.

When the (meth) acrylic acid ester polymer (A) contains an alicyclic structure-containing monomer as a monomer unit constituting the polymer, it preferably contains 1% by mass or more of the alicyclic structure-containing monomer. In particular, it is preferably contained in an amount of 4% by mass or more, and more preferably 8% by mass or more. Further, the (meth) acrylic acid ester polymer (A) preferably contains 30% by mass or less of an alicyclic structure-containing monomer, and particularly 22% by mass or less, as a monomer unit constituting the polymer. It is preferable that the content is 14% by mass or less. When the content of the alicyclic structure-containing monomer is in the above range, the obtained adhesive has more excellent step-following property and blister resistance, and has more excellent adhesive force to plastic.

Further, it is also preferable that the (meth) acrylic acid ester polymer (A) contains a nitrogen atom-containing monomer as a monomer unit constituting the polymer. By allowing a nitrogen atom-containing monomer to be present in the polymer as a constituent unit, a predetermined polarity is imparted to the pressure-sensitive adhesive, and the adhesive has excellent affinity for an adherend having a certain degree of polarity such as glass. Can be. As the nitrogen atom-containing monomer, a monomer having a nitrogen-containing heterocycle is preferable from the viewpoint of imparting appropriate rigidity to the (meth) acrylic acid ester polymer (A). Further, from the viewpoint of increasing the degree of freedom of the portion derived from the nitrogen atom-containing monomer in the higher-order structure of the constituent pressure-sensitive adhesive, the nitrogen atom-containing monomer forms the (meth) acrylic acid ester polymer (A). It is preferable that no reactive unsaturated double bond group is contained other than one polymerizable group used for the polymerization of. The above-mentioned reactive functional group-containing monomer is excluded from the nitrogen atom-containing monomer referred to here.

Examples of the monomer having a nitrogen-containing heterocycle include N- (meth) acryloyl morpholine, N-vinyl-2-pyrrolidone, N- (meth) acryloyl pyrrolidone, N- (meth) acryloyl piperidine, and N- (meth) acryloyl. Pyrrolidine, N- (meth) acryloyl azylidine, aziridinyl ethyl (meth) acrylate, 2-vinylpyridine, 4-vinylpyridine, 2-vinylpyrazine, 1-vinylimidazole, N-vinylcarbazole, N-vinylphthalimide, etc. Among them, N- (meth) acryloylmorpholin, which exhibits more excellent adhesive strength, is preferable, and N-acryloylmorpholin is particularly preferable. These may be used individually by 1 type, and may be used in combination of 2 or more type.

When the (meth) acrylic acid ester polymer (A) contains a nitrogen atom-containing monomer as a monomer unit constituting the polymer, the (meth) acrylic acid ester polymer (A) preferably contains the nitrogen atom-containing monomer in an amount of 1% by mass or more, particularly 4% by mass. It is preferably contained in an amount of% or more, and more preferably 8% by mass or more. Further, the (meth) acrylic acid ester polymer (A) preferably contains the nitrogen atom-containing monomer in an amount of 20% by mass or less, particularly 16% by mass or less, as a monomer unit constituting the polymer. It is preferable, and it is preferable that the content is 12% by mass or less. When the content of the nitrogen atom-containing monomer is within the above range, the obtained pressure-sensitive adhesive can sufficiently exert excellent adhesive strength to glass.

If desired, the (meth) acrylic acid ester polymer (A) may contain another monomer as a monomer unit constituting the polymer. As the other monomer, a monomer containing no reactive functional group is preferable so as not to inhibit the above-mentioned action of the reactive functional group-containing monomer. Examples of such monomers include (meth) acrylic acid alkoxyalkyl esters such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate, vinyl acetate, and styrene. These may be used alone or in combination of two or more.

The (meth) acrylic acid ester polymer (A) is preferably a linear polymer. Since it is a linear polymer, entanglement of molecular chains is likely to occur, and improvement in cohesive force can be expected. Therefore, an adhesive having excellent step followability and blister resistance under high temperature and high humidity conditions can be obtained. easy.

Further, the (meth) acrylic acid ester polymer (A) is preferably a solution polymer obtained by a solution polymerization method. Since it is a solution polymer, it is easy to obtain a high molecular weight polymer, and it is expected that the cohesive force is improved. Therefore, it is easy to obtain an adhesive having excellent step followability and blister resistance under high temperature and high humidity conditions. ..

The polymerization mode of the (meth) acrylic acid ester polymer (A) may be a random copolymer or a block copolymer.

The weight average molecular weight of the (meth) acrylic acid ester polymer (A) is preferably 200,000 or more, particularly preferably 300,000 or more, and further preferably 400,000 or more as the lower limit value. When the lower limit of the weight average molecular weight of the (meth) acrylic acid ester polymer (A) is as described above, the step-following property and blister resistance of the obtained adhesive under high temperature and high humidity conditions become more excellent. ..

The weight average molecular weight of the (meth) acrylic acid ester polymer (A) is preferably 2 million or less, more preferably 1.5 million or less, and particularly preferably 900,000 or less, as an upper limit value. Further, it is preferably 600,000 or less. When the upper limit of the weight average molecular weight of the (meth) acrylic acid ester polymer (A) is as described above, the step-following property of the obtained pressure-sensitive adhesive becomes more excellent. The weight average molecular weight in the present specification is a standard polystyrene-equivalent value measured by a gel permeation chromatography (GPC) method.

In the adhesive composition P, the (meth) acrylic acid ester polymer (A) may be used alone or in combination of two or more.

(1-2) Crosslinking agent (B)
The cross-linking agent (B) can cross-link the (meth) acrylic acid ester polymer (A) by heating the adhesive composition P to form a three-dimensional network structure satisfactorily. As a result, the cohesive force of the obtained adhesive is improved, and the step followability under high temperature and high humidity conditions is excellent.

The cross-linking agent (B) may be any as long as it reacts with the reactive group of the (meth) acrylic acid ester polymer (A). For example, an isocyanate-based cross-linking agent, an epoxy-based cross-linking agent, and an amine-based cross-linking agent. , Melamine-based cross-linking agent, aziridine-based cross-linking agent, hydrazine-based cross-linking agent, aldehyde-based cross-linking agent, oxazoline-based cross-linking agent, metal alkoxide-based cross-linking agent, metal chelate-based cross-linking agent, metal salt-based cross-linking agent, ammonium salt-based cross-linking agent, etc. Can be mentioned. Among the above, when the reactive group of the (meth) acrylic acid ester polymer (A) is a hydroxyl group, it is preferable to use an isocyanate-based cross-linking agent having excellent reactivity with the hydroxyl group, and the (meth) acrylic acid ester. When the reactive group of the polymer (A) is a carboxy group, it is preferable to use an epoxy-based cross-linking agent having excellent reactivity with the carboxy group. The cross-linking agent (B) may be used alone or in combination of two or more.

The isocyanate-based cross-linking agent contains at least a polyisocyanate compound. Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanates, and alicyclic polyisocyanates such as hydrogenated diphenylmethane diisocyanate. , And their biurets, isocyanurates, and adducts, which are reactants with low molecular weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Of these, trimethylolpropane-modified aromatic polyisocyanates, particularly trimethylolpropane-modified tolylene diisocyanate and trimethylolpropane-modified xylylene diisocyanate, are preferable from the viewpoint of reactivity with hydroxyl groups.

Examples of the epoxy-based cross-linking agent include 1,3-bis (N, N-diglycidyl aminomethyl) cyclohexane, N, N, N', N'-tetraglycidyl-m-xylylenediamine, and ethylene glycol diglycidyl ether. , 1,6-Hexanediol diglycidyl ether, trimethylpropan diglycidyl ether, diglycidyl aniline, diglycidyl amine and the like. Of these, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane is preferable from the viewpoint of reactivity with a carboxy group.

The content of the cross-linking agent (B) in the adhesive composition P is preferably 0.01 part by mass or more with respect to 100 parts by mass of the (meth) acrylic acid ester polymer (A), and is 0.03. It is more preferably parts by mass or more, particularly preferably 0.05 parts by mass or more, and further preferably 0.1 parts by mass or more. The content is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, particularly preferably 1 part by mass or less, and further preferably 0.4 parts by mass or less. Is preferable, and 0.25 parts by mass or less is most preferable. When the content of the cross-linking agent (B) is in the above range, the obtained pressure-sensitive adhesive exhibits a good cohesive force, and is excellent in step-following property under high temperature and high humidity conditions.

(1-3) Active energy ray-curable component (C)
The post-curing pressure-sensitive adhesive (the pressure-sensitive adhesive constituting the post-curing pressure-sensitive adhesive layer) obtained by cross-linking the pressure-sensitive adhesive composition P according to the present embodiment with active energy ray-curable. It is presumed that the components (C) are polymerized with each other, and the polymerized active energy ray-curable component (C) is entwined with the crosslinked structure (three-dimensional network structure) of the (meth) acrylic acid ester polymer (A). The pressure-sensitive adhesive having such a high-order structure exhibits extremely excellent durability, and is particularly excellent in step followability and blister resistance under high temperature and high humidity conditions.

The active energy ray-curable component (C) is not particularly limited as long as it is a component that is cured by irradiation with active energy rays and obtains the above effects, and may be any monomer, oligomer or polymer, and they may be used. May be a mixture of. Among them, a polyfunctional acrylate-based monomer having excellent blister resistance can be preferably mentioned.

Examples of the polyfunctional acrylate-based monomer include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and polyethylene glycol di (meth) acrylate. , Neopentyl glycol adipate di (meth) acrylate, neopentyl glycol di (meth) acrylate of hydroxypivalate, dicyclopentanyl di (meth) acrylate, tricyclodecanedimethanol (meth) acrylate, caprolactone-modified dicyclopentenyldi ( Meta) acrylate, ethylene oxide modified di (meth) acrylate, di (acryloxyethyl) isocyanurate, allylated cyclohexyl di (meth) acrylate, ethoxylated bisphenol A diacrylate, 9,9-bis [4- (2-) Bifunctional type such as acryloyloxyethoxy) phenyl] fluorene; trimethylpropantri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid-modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate , Protinoxide-modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, ε-caprolactone-modified tris- (2- (meth) acryloxyethyl) isocyanurate, etc. Four-functional types such as meta) acrylate and pentaerythritol tetra (meth) acrylate; pentafunctional type such as propionic acid-modified dipentaerythritol penta (meth) acrylate; dipentaerythritol hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa ( Examples thereof include a hexafunctional type such as meta) acrylate. These may be used individually by 1 type, and may be used in combination of 2 or more type. Further, from the viewpoint of compatibility with the (meth) acrylic acid ester polymer (A), the polyfunctional acrylate-based monomer preferably has a molecular weight of less than 1000.

Among the above, from the viewpoint of the blister resistance of the obtained adhesive, di (acryloxyethyl) isocyanurate, tris (acryloxyethyl) isocyanurate, ε-caprolactone-modified tris- (2- (meth) acryloxyethyl). A polyfunctional acrylate-based monomer having an isocyanurate structure in the molecule such as isocyanurate, or a polyfunctional acrylate-based monomer having a cyclic structure (particularly a cycloalkane structure) in the molecule such as tricyclodecanedimethanol (meth) acrylate. Is preferable, a polyfunctional acrylate-based monomer having a trifunctionality or higher and containing an isocyanurate structure in the molecule, or a polyfunctional acrylate-based monomer having a bifunctionality or higher and having a polycyclic structure (particularly a cycloalkane polycyclic structure) in the molecule. Functional acrylate-based monomers are more preferred, ε-caprolactone-modified tris- (2- (meth) acryloxiethyl) isocyanurate or tricyclodecanedimethanol (meth) acrylate is particularly preferred, and ε-caprolactone-modified tris- (2-acrylate). Loxyethyl) isocyanurate or tricyclodecanedimethanol acrylate is more preferred, and ε-caprolactone-modified tris- (2-acryloxyethyl) isocyanurate is most preferred.

The content of the active energy ray-curable component (C) in the adhesive composition P is a (meth) acrylic acid ester polymer (meth) from the viewpoint of making the blister resistance of the obtained post-curing adhesive more excellent. A) With respect to 100 parts by mass, the lower limit is preferably 1 part by mass or more, particularly preferably 3 parts by mass or more, and further preferably 4 parts by mass or more. On the other hand, the above content is preferably 20 parts by mass or less as an upper limit value from the viewpoint of the adhesive strength of the obtained cured adhesive, and by extension, the step followability and blister resistance under high temperature and high humidity conditions. It is particularly preferably less than or equal to parts by mass, and even more preferably less than or equal to 8 parts by mass.

(1-4) Colorant (D)
The colorant (D) is the colorant described above. The specific type and the content in the pressure-sensitive adhesive are as described above.

The content of the colorant (D) with respect to 100 parts by mass of the (meth) acrylic acid ester polymer (A) is preferably 0.01 part by mass or more, more preferably 0.05 part by mass or more. In particular, it is preferably 0.1 part by mass or more, and further preferably 0.15 part by mass or more. The content is preferably 2 parts by mass or less, more preferably 1 part by mass or less, particularly preferably 0.5 parts by mass or less, and further preferably 0.2 parts by mass or less. It is preferable to have.

(1-5) Photopolymerization Initiator (E)
When ultraviolet rays are used as the active energy rays for curing the adhesive composition P, the adhesive composition P preferably further contains a photopolymerization initiator (E). By containing the photopolymerization initiator (E) in this way, the active energy ray-curable component (C) can be efficiently polymerized, and the polymerization curing time and the irradiation amount of the active energy rays can be reduced. it can.

Examples of such a photopolymerization initiator (E) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, and 2,2-dimethoxy. -2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4- (Methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylamino Benzophenone, Dichlorobenzophenone, 2-Methylanthraquinone, 2-Ethylanthraquinone, 2-Turrary-butylanthraquinone, 2-Aminoanthraquinone, 2-Methylthioxanthone, 2-Ethylthioxanthone, 2-Chlorothioxanthone, 2,4-dimethylthioxanthone, 2 , 4-Diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, oligo [2-hydroxy-2-methyl-1 [4- (1-methylvinyl) phenyl] propanone], 2,4 , 6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide and the like. These may be used alone or in combination of two or more.

Among the above, a phosphine oxide-based photopolymerization initiator that easily cleaves and reliably cures the pressure-sensitive adhesive even when ultraviolet rays are irradiated through a plastic plate containing an ultraviolet absorber is preferable. Specifically, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide and the like are preferable.

The content of the photopolymerization initiator (E) in the adhesive composition P is preferably 0.1 part by mass or more as a lower limit value with respect to 100 parts by mass of the active energy ray-curable component (C). In particular, it is preferably 1 part by mass or more, and more preferably 5 parts by mass or more. Further, the upper limit value is preferably 30 parts by mass or less, particularly preferably 20 parts by mass or less, and further preferably 12 parts by mass or less.

The mass ratio of the amount of the photopolymerization initiator (E) to the amount of the colorant (D) (photopolymerization initiator (E) / colorant (D)) is preferably 0.5 or more, and particularly 1 or more. Is preferable, and more preferably 2 or more. The ratio is preferably 20 or less, more preferably 12 or less, particularly preferably 8 or less, and further preferably 4 or less. Since the ratio of the amount of the photopolymerization initiator (E) to the amount of the colorant (D) is in the above range, it is more suitable for active energy ray curing while making the total light transmittance and the brightness L * suitable. A pressure-sensitive adhesive having cohesive power and adhesiveness can be easily obtained, and the blister resistance tends to be more excellent.

(1-6) Various Additives The adhesive composition P contains various additives usually used for acrylic pressure-sensitive adhesives, such as silane coupling agents, rust preventives, ultraviolet absorbers, and antistatic agents, if desired. , Antistatic agents, light stabilizers, softeners, refractive index adjusters and the like can be added. The polymerization solvent and the diluting solvent described later are not included in the additives constituting the adhesive composition P.

The adhesive composition P preferably contains a silane coupling agent among the above. As a result, regardless of whether the adherend is a plastic plate or a glass member, the adhesion to the adherend is improved, and the step followability and blister resistance under high temperature and high humidity conditions are more excellent. It will be a blister.

The silane coupling agent is an organosilicon compound having at least one alkoxysilyl group in the molecule, which has good compatibility with the (meth) acrylic acid ester polymer (A) and has light transmittance. preferable.

Examples of such a silane coupling agent include polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, and methacrypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 2-(. 3,4-Epoxycyclohexyl) Silicon compounds having an epoxy structure such as ethyltrimethoxysilane, mercapto group-containing silicon compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyldimethoxymethylsilane , 3-Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane and other amino group-containing silicon compounds, 3-Chloropropyltrimethoxysilane, 3-isocyanuppropyltriethoxysilane, or at least one of these, and alkyl group-containing silicon compounds such as methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, and ethyltrimethoxysilane. Examples thereof include a condensate of. These may be used individually by 1 type, and may be used in combination of 2 or more type.

The content of the silane coupling agent in the adhesive composition P is preferably 0.01 part by mass or more, particularly 0.05 parts by mass, based on 100 parts by mass of the (meth) acrylic acid ester polymer (A). It is preferably 7 parts by mass or more, and more preferably 0.08 parts by mass or more. The content is preferably 1 part by mass or less, particularly preferably 0.5 part by mass or less, and further preferably 0.3 part by mass or less.

(2) Preparation of Adhesive Composition The adhesive composition P produced a (meth) acrylic acid ester polymer (A), and the obtained (meth) acrylic acid ester polymer (A) and a cross-linking agent ( It can be produced by mixing B), the active energy ray-curable component (C), and the colorant (D), and adding an additive if desired.

The (meth) acrylic acid ester polymer (A) can be produced by polymerizing a mixture of monomers constituting the polymer by a usual radical polymerization method. The polymerization of the (meth) acrylic acid ester polymer (A) is preferably carried out by a solution polymerization method using a polymerization initiator, if desired. Examples of the polymerization solvent include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, methyl ethyl ketone and the like, and two or more of them may be used in combination.

Examples of the polymerization initiator include azo compounds and organic peroxides, and two or more of them may be used in combination. Examples of the azo compound include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane1-carbonitrile), and 2, , 2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis (2-methylpropionate) 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropionitrile), 2,2'-azobis [2- (2-imidazolin-2-yl)) Propane] and the like.

Examples of the organic peroxide include benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxy dicarbonate, di-n-propyl peroxy dicarbonate, and di (2-ethoxyethyl) peroxy. Examples thereof include dicarbonate, t-butylperoxyneodecanoate, t-butylperoxyvivarate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, and diacetyl peroxide.

In the above polymerization step, the weight average molecular weight of the obtained polymer can be adjusted by adding a chain transfer agent such as 2-mercaptoethanol.

Once the (meth) acrylic acid ester polymer (A) is obtained, the cross-linking agent (B), the active energy ray-curable component (C), and the colorant (colorant) are added to the solution of the (meth) acrylic acid ester polymer (A). D) and, if desired, a diluting solvent and additives are added and mixed well to obtain a solvent-diluted tacky composition P (coating solution). If any of the above components is in the form of a solid, or if precipitation occurs when the component is mixed with another component in an undiluted state, the component is used alone as a diluting solvent in advance. It may be dissolved or diluted and then mixed with other ingredients.

Examples of the diluting solvent include aliphatic hydrocarbons such as hexane, heptane and cyclohexane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, methanol, ethanol, propanol and butanol. Alcohols such as 1-methoxy-2-propanol, ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone and cyclohexanone, esters such as ethyl acetate and butyl acetate, and cellosolve solvents such as ethyl cellosolve are used.

The concentration and viscosity of the coating solution prepared in this manner may be any range as long as it can be coated, and is not particularly limited and can be appropriately selected depending on the situation. For example, the adhesive composition P is diluted so as to have a concentration of 10 to 60% by mass. It should be noted that the addition of a diluting solvent or the like is not a necessary condition when obtaining the coating solution, and the diluting solvent may not be added as long as the adhesive composition P has a coatable viscosity. In this case, the adhesive composition P becomes a coating solution using the polymerization solvent of the (meth) acrylic acid ester polymer (A) as it is as a diluting solvent.

(3) Formation of Adhesive Layer The pressure-sensitive adhesive layer 11 in the present embodiment is preferably made of a pressure-sensitive adhesive obtained by cross-linking the pressure-sensitive adhesive composition P (coating layer). Crosslinking of the adhesive composition P can usually be carried out by heat treatment. In addition, this heat treatment can also serve as a drying treatment when volatilizing the diluting solvent or the like from the coating layer of the adhesive composition P applied to the desired object.

The heating temperature of the heat treatment is preferably 50 to 150 ° C, particularly preferably 70 to 120 ° C. The heating time is preferably 10 seconds to 10 minutes, and particularly preferably 50 seconds to 2 minutes.

After the heat treatment, if necessary, a curing period of about 1 to 2 weeks may be provided at room temperature (for example, 23 ° C., 50% RH). If this curing period is required, the adhesive is formed after the curing period has elapsed, and if the curing period is not required, after the heat treatment is completed.

By the above heat treatment (and curing), the (meth) acrylic acid ester polymer (A) is sufficiently crosslinked via the crosslinking agent (B). The pressure-sensitive adhesive thus obtained has excellent step followability under high temperature and high humidity conditions.

(4) Physical Properties of Adhesive The gel fraction of the adhesive according to the present embodiment is preferably 20% or more, more preferably 30% or more, and particularly preferably 40% or more as the lower limit value. It is preferable, and more preferably 45% or more. When the lower limit of the gel fraction of the pressure-sensitive adhesive is the above, the cohesive force of the pressure-sensitive adhesive becomes high, and the step followability under high temperature and high humidity conditions becomes more excellent. The gel fraction of the pressure-sensitive adhesive according to the present embodiment is preferably 90% or less, more preferably 80% or less, particularly preferably 70% or less, and further preferably 60% or less as an upper limit value. % Or less is preferable. When the upper limit of the gel fraction of the pressure-sensitive adhesive is the above, the pressure-sensitive adhesive does not become too hard, and both the initial step-following property and the step-following property after durability are excellent. In addition, good adhesive strength is exhibited, and the adhesiveness with the adherend becomes more excellent. Here, the method for measuring the gel fraction of the pressure-sensitive adhesive is as shown in a test example described later.

(5) Thickness of Adhesive Layer The thickness (Z μm) of the adhesive layer 11 in the adhesive sheet 1 according to the present embodiment is preferably a value satisfying the above-mentioned X × Z formula (I).

Specifically, the thickness of the pressure-sensitive adhesive layer 11 is preferably 25 μm or more, and more preferably 40 μm or more as the lower limit value. When the lower limit of the thickness of the pressure-sensitive adhesive layer 11 is the above, the total light transmittance and the lightness L * (furthermore, the chromaticities a * and b *, as described above, in relation to the content of the colorant (D), are described. In addition, the haze value) is easily satisfied, and the desired adhesive strength is easily exhibited. Further, from the viewpoint of facilitating excellent step followability and blister resistance, the lower limit value is preferably 50 μm or more, more preferably 75 μm or more, and particularly preferably 100 μm or more. It is more preferably 120 μm or more.

The thickness of the pressure-sensitive adhesive layer 11 is preferably 1000 μm or less, more preferably 500 μm or less, particularly preferably 300 μm or less, and further preferably 250 μm or less as an upper limit value. When the upper limit of the thickness of the pressure-sensitive adhesive layer 11 is the above, the processability becomes good. In addition, appearance defects due to push marks and the like are less likely to occur. Further, in relation to the content of the colorant (D), the above-mentioned total light transmittance and lightness L * (furthermore, chromaticities a * and b *, and haze value) are easily satisfied. The pressure-sensitive adhesive layer 11 may be formed as a single layer, or may be formed by laminating a plurality of layers.

1-2. Peeling Sheets The peeling sheets 12a and 12b protect the pressure-sensitive adhesive layer 11 until the time when the pressure-sensitive adhesive sheet 1 is used, and are peeled off when the pressure-sensitive adhesive sheet 1 (the pressure-sensitive adhesive layer 11) is used. In the pressure-sensitive adhesive sheet 1 according to the present embodiment, one or both of the release sheets 12a and 12b are not always necessary.

Examples of the release sheets 12a and 12b include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, and polybutylene. Telephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, fluorine A resin film or the like is used. In addition, these crosslinked films are also used. Further, these laminated films may be used.

It is preferable that the peeling surfaces (particularly the surfaces in contact with the pressure-sensitive adhesive layer 11) of the peeling sheets 12a and 12b are subjected to a peeling treatment. Examples of the release agent used in the release treatment include alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents. Of the release sheets 12a and 12b, it is preferable that one release sheet is a heavy release type release sheet having a large release force and the other release sheet is a light release type release sheet having a small release force.

The thickness of the release sheets 12a and 12b is not particularly limited, but is usually about 20 to 150 μm.

2. Production of Adhesive Sheet As an example of production of the adhesive sheet 1, the coating solution of the adhesive composition P is applied to the peeling surface of one of the release sheets 12a (or 12b) and heat-treated to perform the adhesive composition. After P is thermally crosslinked to form a coating layer, the peeling surface of the other release sheet 12b (or 12a) is superposed on the coating layer. When the curing period is required, the curing period is set, and when the curing period is not required, the coating layer becomes the adhesive layer 11 as it is. As a result, the adhesive sheet 1 is obtained. The conditions for heat treatment and curing are as described above.

As another production example of the pressure-sensitive adhesive sheet 1, the coating solution of the pressure-sensitive adhesive composition P is applied to the peel-off surface of one of the release sheets 12a, heat-treated to heat-crosslink the pressure-sensitive adhesive composition P, and then coated. A layer is formed to obtain a release sheet 12a with a coating layer. Further, the coating solution of the adhesive composition P is applied to the peeling surface of the other release sheet 12b, heat treatment is performed to thermally crosslink the adhesive composition P to form a coating layer, and the coating layer is attached. To obtain the release sheet 12b of. Then, the release sheet 12a with the coating layer and the release sheet 12b with the coating layer are bonded so that both coating layers are in contact with each other. Here, a plurality of release sheets with a coating layer may be prepared, and a desired number of the coating layers may be bonded together. When the curing period is required, the curing period is set, and when the curing period is not required, the laminated coating layer becomes the pressure-sensitive adhesive layer 11. As a result, the adhesive sheet 1 is obtained. According to this production example, even when the pressure-sensitive adhesive layer 11 is thick, stable production is possible.

As a method of applying the coating solution of the adhesive composition P, for example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method and the like can be used.

[Display body]
Types of displays according to this embodiment include, for example, in-vehicle displays in automobile instrument panels, car navigation systems, various instruments provided on consoles, tablet terminals for general users, and the like. Examples thereof include a display body, a display body such as a commercial tablet terminal and a digital signage, and a display body such as an outdoor digital signage. These display bodies may be required to have an appearance harmony with peripheral members and a sense of quality. However, the display body according to the present invention is not limited to these.

As shown in FIG. 2, the display body 2 according to the present embodiment includes a first display body constituent member 21 (one display body constituent member) and a second display body constituent member 22 (another display body constituent member). ) And a cured pressure-sensitive adhesive layer 11'positioned between them and for bonding the first display body constituent member 21 and the second display body constituent member 22 to each other.

At least one of the first display body constituent member 21 and the second display body constituent member 22 may have a step on the surface on the side to be bonded by the adhesive layer 11'after curing. In the present embodiment shown in FIG. 2, the first display body component 21 has a step such as a printing layer 3 on the surface on the adhesive layer 11'side after curing.

The cured pressure-sensitive adhesive layer 11'in the display body 2 is obtained by curing the pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 1 described above by irradiation with active energy rays. When the adhesive composition P is used for forming the adhesive layer 11, the post-curing adhesive constituting the post-curing pressure-sensitive adhesive layer 11'is a (meth) acrylic acid ester polymer (A) and a cross-linking agent (D). ), A cured product (polymer) of the active energy ray-curable component (C) is contained, and in some cases, a photopolymerization initiator (E) and an additive are further contained. It is presumed that the active energy ray-curable component (C) is polymerized to form a three-dimensional network structure in which the network is roughened to some extent, and is entwined with the above-mentioned crosslinked structure to form a higher-order structure. .. With such a structure, excellent blister resistance is exhibited.

As for the photopolymerization initiator (E) contained in the post-curing pressure-sensitive adhesive constituting the post-curing pressure-sensitive adhesive layer 11', the photopolymerization initiator (E) contained in the adhesive composition P has active energy. It remained without being cleaved even by beam irradiation. Therefore, the content thereof is not large, and is usually 0.0001% by mass or more and 0.1% by mass or less, preferably 0.0001% by mass or more and 0.01% by mass or less in the pressure-sensitive adhesive. ..

The thickness of the pressure-sensitive adhesive layer 11'after curing is basically the same as the thickness of the pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 1.

The gel fraction of the post-curing pressure-sensitive adhesive constituting the post-curing pressure-sensitive adhesive layer 11'is preferably 55% or more, more preferably 60% or more, and particularly 65% or more as a lower limit value. It is preferable, and more preferably 67% or more. When the lower limit of the gel fraction of the cured pressure-sensitive adhesive is as described above, the blister resistance of the cured pressure-sensitive adhesive layer 11'will be more excellent. The gel fraction of the cured adhesive is preferably 95% or less, more preferably 90% or less, particularly preferably 80% or less, and further preferably 74% or less as an upper limit value. It is preferable to have. When the upper limit of the gel fraction of the cured adhesive is the above, the adhesive strength of the cured adhesive layer 11', and by extension, the step followability and blister resistance under high temperature and high humidity conditions become more excellent. .. The method for measuring the gel fraction of the cured adhesive is as shown in a test example described later.

The adhesive strength of the cured pressure-sensitive adhesive layer 11'to soda lime glass is preferably 10 N / 25 mm or more, preferably 20 N / 25 mm or more, and more preferably 30 N / 25 mm or more as a lower limit value. It is particularly preferably 40 N / 25 mm or more, and further preferably 50 N / 25 mm or more. When the lower limit of the adhesive force is the above, the step followability and the blister resistance under high temperature and high humidity conditions become more excellent. The upper limit of the adhesive strength is not particularly limited, but is preferably 100 N / 25 mm or less, more preferably 80 N / 25 mm or less, and particularly preferably 60 N / 25 mm or less.

Here, the adhesive strength in the present specification basically means the adhesive strength measured by the 180-degree peeling method according to JIS Z0237: 2009, but the measurement sample is 25 mm wide and 100 mm long, and the measurement sample is used. It is attached to an adherend, pressurized at 0.5 MPa and 50 ° C. for 20 minutes, left at normal pressure, 23 ° C. and 50% RH for 24 hours, and then measured at a peeling speed of 300 mm / min. It shall be.

Examples of the display body 2 include a liquid crystal (LCD) display, a light emitting diode (LED) display, an organic electroluminescence (organic EL) display, electronic paper, and the like, and may be a touch panel.

The first display body component 21 is preferably a protective panel made of a glass plate, a plastic plate, or the like, or a laminated body containing them, and in particular, is made of a plastic plate, a laminated body including the plastic plate, or the like. It is preferably a protective panel. In this case, the printed layer 3 is generally formed in a frame shape on the cured pressure-sensitive adhesive layer 11'side of the first display body constituent member 21.

The glass plate is not particularly limited, and for example, chemically strengthened glass, non-alkali glass, quartz glass, soda lime glass, barium / strontium-containing glass, aluminosilicate glass, lead glass, borosilicate glass, barium borosilicate. Examples include glass. The thickness of the glass plate is not particularly limited, but is usually 0.1 to 5 mm, preferably 0.2 to 2 mm.

Normally, when the plastic plate is placed under high temperature conditions, for example, 85 ° C., the low boiling point components inside are vaporized, and bubbles and floats are formed at the interface between the plastic plate and the cured adhesive layer 11'. , There is a risk of blister such as peeling. However, even if the display body 2 according to the present embodiment includes such a plastic plate, when the adhesive composition P is used for forming the adhesive layer 11, the adhesive layer 11'after curing causes blisters. Can be satisfactorily suppressed.

The plastic plate is not particularly limited, and is, for example, an acrylic resin plate such as a polycarbonate resin (PC) plate or a polymethyl methacrylate resin (PMMA) plate, or an acrylic resin such as a polymethyl methacrylate resin layer on the polycarbonate resin plate. Examples thereof include a plastic plate in which layers are laminated. The above-mentioned polycarbonate resin plate may contain a resin other than the polycarbonate resin as a material constituting the above-mentioned polycarbonate resin plate, and the above-mentioned acrylic resin plate may contain a resin other than the acrylic resin as the material constituting the above-mentioned acrylic resin plate. It may be contained. The plastic plate may contain an ultraviolet absorber.

The thickness of the plastic plate is not particularly limited, but is usually 0.2 to 5 mm, preferably 0.4 to 3 mm, particularly preferably 0.6 to 2.5 mm, and further preferably 1 to 1. It is 2.1 mm.

Various functional layers (transparent conductive film, metal layer, silica layer, hard coat layer, antiglare layer, etc.) may be provided on one side or both sides of the glass plate or the plastic plate, or optical members are laminated. It may have been done. Further, the transparent conductive film and the metal layer may be patterned.

The second display body constituent member 22 is an optical member to be attached to the first display body constituent member 21, a display body module (for example, a liquid crystal (LCD) module, a light emitting diode (LED) module, and an organic electroluminescence (organic). An EL) module or the like), an optical member as a part of the display body module, or a laminated body including the display body module is preferable.

Examples of the optical member include a shatterproof film, a polarizing plate (polarizing film), a polarizer, a retardation plate (phase difference film), a viewing angle compensation film, a brightness improving film, a contrast improving film, a liquid crystal polymer film, and a diffusion film. , Semi-transmissive reflective film, transparent conductive film and the like. Examples of the shatterproof film include a hard coat film in which a hard coat layer is formed on one side of the base film.

The material constituting the print layer 3 is not particularly limited, and a known material for printing is used. The thickness of the print layer 3, that is, the lower limit of the height of the step is preferably 3 μm or more, more preferably 5 μm or more, particularly preferably 7 μm or more, and most preferably 10 μm or more. preferable. When the lower limit value is equal to or higher than the above value, it is possible to sufficiently secure concealment such as making the electrical wiring invisible to the viewer. The upper limit is preferably 50 μm or less, more preferably 35 μm or less, particularly preferably 25 μm or less, and even more preferably 20 μm or less. When the upper limit value is not more than the above, it is possible to prevent deterioration of the step followability of the adhesive layer 11'after curing with respect to the printing layer 3.

In order to manufacture the display body 2, as an example, one of the release sheets 12a of the pressure-sensitive adhesive sheet 1 is peeled off, and the exposed pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 1 is separated from the printed layer of the first display body component 21. It is affixed to the surface on the side where 3 exists.

Next, the other release sheet 12b is peeled from the pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 1, and the exposed pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 1 and the second display body component 22 are bonded to each other to obtain a laminated body. .. Further, as another example, the bonding order of the first display body constituent member 21 and the second display body constituent member 22 may be changed.

Then, the pressure-sensitive adhesive layer 11 in the laminated body is irradiated with active energy rays. As a result, the energy ray-curable component (C) in the pressure-sensitive adhesive layer 11 is polymerized, and the pressure-sensitive adhesive layer 11 is cured to become the pressure-sensitive adhesive layer 11'after curing. The pressure-sensitive adhesive layer 11 is usually irradiated with energy rays through either the first display body component 21 or the second display body component 22, preferably the first display body as a protective panel. This is done through the component 21.

Here, the active energy beam refers to an electromagnetic wave or a charged particle beam having an energy quantum, and specific examples thereof include an ultraviolet ray and an electron beam. Among the active energy rays, ultraviolet rays, which are easy to handle, are particularly preferable.

Irradiation of ultraviolet rays, a high-pressure mercury lamp, a fusion H lamp, can be carried out by a xenon lamp or the like, the dose of ultraviolet ray is preferably illuminance is 50~1000mW / cm ² approximately, 100~500mW / cm ² of about Is preferable. Further, the light quantity is preferably 50~10000mJ / cm ^2, more preferably 200~7000mJ / cm ^2, and particularly preferably 500~3000mJ / cm ^2. On the other hand, the irradiation of the electron beam can be performed by an electron beam accelerator or the like, and the irradiation amount of the electron beam is preferably about 10 to 1000 grad.

As shown in FIG. 3, the display body 2 according to the present embodiment preferably has a frame member 4 at the peripheral edge of the display body 2. The frame material 4 is preferably black. Further, the preferable ranges of the lightness L *, the chromaticity a * and the chromaticity b * defined by the CIE1976L * a * b * color system as the color of the frame material 4 are as described above as the color of the peripheral members. Is. Since the frame material 4 has such a color, it is easily recognized by the human eye as a frame material having a visually high-class feeling. Further, the cured pressure-sensitive adhesive layer 11'in the present embodiment has the above-mentioned color in the frame material 4, so that the feeling of unity with the frame material 4 is increased and the harmony is improved.

In the display body 2, the adhesive layer 11'after curing, which inherits the physical characteristics (total light transmittance, brightness L *, etc.) of the adhesive layer 11 described above, imparts a sense of unity with the black frame material 4. , Has excellent appearance harmony. Further, the display body 2 ensures visibility as a display body.

Further, in the display body 2, when the pressure-sensitive adhesive layer 11 is formed from the pressure-sensitive adhesive composition P, the pressure-sensitive adhesive layer 11'after curing is excellent in step-following property under high temperature and high humidity conditions. Even when the body 2 is placed under high temperature and high humidity conditions (for example, 85 ° C., 85% RH), the generation of air bubbles, floats, peeling, etc. in the vicinity of the step is suppressed.

Further, in the display body 2, when the pressure-sensitive adhesive layer 11 is formed from the pressure-sensitive adhesive composition P, the pressure-sensitive adhesive layer 11'after curing has excellent blister resistance, so that the display body 2 is, for example, high temperature and high temperature. After curing, the pressure-sensitive adhesive layer 11 even when outgas is generated from the first display body component 21 and / or the second display body component 22 under wet conditions (for example, 85 ° C., 85% RH). It is possible to suppress the generation of blister such as air bubbles, floating, and peeling at the interface between the display body constituent members 21 and 22.

The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

For example, either or both of the release sheets 12a and 12b in the pressure-sensitive adhesive sheet 1 may be omitted, and desired optical members may be laminated in place of the release sheets 12a and / or 12b. Further, the first display body constituent member 21 may not have a step. Further, not only the first display body constituent member 21 but also the second display body constituent member 22 may have a step on the adhesive layer 11'side after curing.

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope of the present invention is not limited to these Examples and the like.

[Example 1]
1. 1. Preparation of (meth) acrylic acid ester polymer 65 parts by mass of 2-ethylhexyl acrylate, 10 parts by mass of isobornyl acrylate, 10 parts by mass of N-acryloyl morpholine, and 15 parts by mass of 2-hydroxyethyl acrylate are copolymerized by a solution polymerization method. It was polymerized to prepare a (meth) acrylic acid ester polymer (A). When the molecular weight of this (meth) acrylic acid ester polymer (A) was measured by the method described later, the weight average molecular weight (Mw) was 500,000.

2. Preparation of Adhesive Composition 100 parts by mass (solid content conversion value; the same applies hereinafter) of the (meth) acrylic acid ester polymer (A) obtained in the above step 1 and trimethylolpropane-modified bird as a cross-linking agent (B). 0.2 parts by mass of range isocyanate (manufactured by Toyochem Co., Ltd., product name "BHS8515") and ε-caprolactone-modified tris- (2-acryloxyethyl) isocyanurate (C1: new) as an active energy ray-curable component (C). Nakamura Chemical Co., Ltd., product name "NK ester A-9300-1CL") 5.0 parts by mass and carbon black black pigment as colorant (D) (Toyo Color Co., Ltd., "Multilac Black") 0. 08 parts by mass, 0.5 parts by mass of a mixture (E1) of 1-hydroxycyclohexylphenyl ketone and benzophenone as a photopolymerization initiator (E) in a mass ratio of 1: 1 and 3-glyceride as a silane coupling agent. A coating solution of the adhesive composition was obtained by mixing with 0.1 part by mass of sidoxylpropyltrimethoxysilane, stirring well, and diluting with methyl ethyl ketone.

Here, Table 1 shows each formulation (solid content conversion value) of the adhesive composition when the (meth) acrylic acid ester polymer (A) is 100 parts by mass (solid content conversion value). In addition, the mass ratio of the amount of the photopolymerization initiator (E) to the amount of the colorant (D) (photopolymerization initiator (E) / colorant (D)) was calculated and shown in Table 1. Details of the abbreviations and the like shown in Table 1 are as follows.
[(Meta) Acrylic Ester Polymer (A)]
2EHA: 2-ethylhexyl acrylate IBXA: isobornyl acrylate ACMO: N-acryloylmorpholin HEA: 2-hydroxyethyl acrylate MMA: methyl methacrylate BA: n-butyl acrylate AA: acrylic acid
[Crosslinking agent (B)]
TDI: Trimethylolpropane-modified tolylene diisocyanate (manufactured by Toyochem, product name "BHS8515")
XDI: Trimethylolpropane-modified xylylene diisocyanate (manufactured by Soken Chemical Co., Ltd., product name "TD-75")
Epoxy: 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane (manufactured by Mitsubishi Gas Chemical Company, product name "TETRAD-C")
[Active energy ray-curable component (C)]
C1: ε-caprolactone-modified tris- (2-acryloxyethyl) isocyanurate (manufactured by Shin Nakamura Chemical Industry Co., Ltd., product name "NK ester A-9300-1CL")
C2: Tricyclodecanedimethanol diacrylate
[Colorant (D)]
Pigment: Carbon black black pigment (manufactured by Toyo Color Co., Ltd., "Multi Rack Black")
Dye: Niglosin black dye (manufactured by Orient Chemical Industry Co., Ltd., product name "NUBIAN BLACK PA-2802")
[Photopolymerization Initiator (E)]
E1: 1-Hydroxycyclohexylphenyl ketone and benzophenone mass ratio 1: 1 mixture E2: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide

3. 3. Manufacture of adhesive sheets

Peeling of a heavy peeling type release sheet (manufactured by Lintec Corporation, product name "SP-PET752150") obtained by peeling one side of a polyethylene terephthalate film with a silicone-based release agent from the coating solution of the adhesive composition obtained in the above step 2. The treated surface was coated with a knife coater. Then, the coating layer was heat-treated at 90 ° C. for 1 minute to form a coating layer (thickness: 25 μm), thereby producing a heavy peeling type release sheet with a coating layer.

On the other hand, a light peeling type release sheet (manufactured by Lintec Corporation, product name "SP-PET382120") obtained by peeling one side of a polyethylene terephthalate film with a silicone-based release agent from the coating solution of the adhesive composition obtained in the above step 2. It was applied to the peeled surface of the above with a knife coater. Then, the coated layer was heat-treated at 90 ° C. for 1 minute to form a coated layer (thickness: 25 μm), thereby producing four lightly peelable release sheets with the coated layer.

The surface on the coating layer side of the heavy peeling type release sheet with the coating layer obtained above and the surface on the coating layer side in one of the light peeling type release sheets with the coating layer obtained above are attached. In combination, a coating layer having a thickness of 50 μm was obtained as a first laminate sandwiched between the heavy-release type release sheet and the light-release type release sheet.

Next, the light release type release sheet is peeled off from the first laminate, and the exposed surface of the exposed coating layer and the coating layer in one of the light release type release sheets with the coating layer obtained above. The side surfaces were bonded to each other to obtain a second laminate in which a coating layer having a thickness of 75 μm was sandwiched between the heavy release type release sheet and the light release type release sheet. By repeating the same steps as this, a fourth laminated body in which the coating layer having a thickness of 125 μm was sandwiched between the heavy release type release sheet and the light release type release sheet was obtained.

Then, the fourth laminate is cured under the conditions of 23 ° C. and 50% RH for 7 days to form a heavy release type release sheet / adhesive layer (thickness: 125 μm) / light release type release sheet. An adhesive sheet made of was manufactured.

The thickness of the pressure-sensitive adhesive layer is a value measured using a constant pressure thickness measuring device (manufactured by Teclock Co., Ltd., product name "PG-02") in accordance with JIS K7130.

[Examples 2 to 11, Comparative Examples 1 to 2, Reference Example 1]
Types and proportions of each monomer constituting the (meth) acrylic acid ester polymer (A), weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer (A), type and blending amount of the cross-linking agent (B). , Type and amount of active energy ray-curable component (C), type and amount of colorant (D), type and amount of photopolymerization initiator (E), and amount of silane coupling agent. An adhesive sheet was produced in the same manner as in Example 1 except for the modification as shown in 1.

Here, X × when the content of the colorant in the pressure-sensitive adhesive layer (tacky composition) formed in Examples, Comparative Examples and Reference Examples is X mass% and the thickness of the pressure-sensitive adhesive layer is Z μm. Z was calculated. The results are shown in Table 1.

The above-mentioned weight average molecular weight (Mw) is a polystyrene-equivalent weight average molecular weight measured under the following conditions (GPC measurement) using gel permeation chromatography (GPC).
<Measurement conditions>
-GPC measuring device: HLC-8020 manufactured by Tosoh Corporation
-GPC column (passed in the following order): TSK guard volume HXL-H manufactured by Tosoh Corporation
TSK gel GMHXL (x2)
TSK gel G2000HXL
-Measurement solvent: tetrahydrofuran-Measurement temperature: 40 ° C

[Test Example 1] (Measurement of gel fraction)
The adhesive sheets obtained in Examples, Comparative Examples and Reference Examples are cut into a size of 80 mm × 80 mm, the adhesive layer is wrapped in a polyester mesh (mesh size 200), and the mass is weighed with a precision balance. , The mass of the adhesive alone was calculated by subtracting the mass of the mesh alone. The mass at this time is M1.

Next, the pressure-sensitive adhesive wrapped in the polyester mesh was immersed in ethyl acetate at room temperature (23 ° C.) for 24 hours. Then, the adhesive was taken out, air-dried for 24 hours in an environment of a temperature of 23 ° C. and a relative humidity of 50%, and further dried in an oven at 80 ° C. for 12 hours. After drying, the mass was weighed with a precision balance, and the mass of the adhesive alone was calculated by subtracting the mass of the mesh alone. The mass at this time is M2. The gel fraction (%) is represented by (M2 / M1) × 100. As a result, the gel fraction of the pressure-sensitive adhesive (before UV irradiation) was derived. The results are shown in Table 2.

On the other hand, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheets obtained in Examples, Comparative Examples and Reference Examples is irradiated with active energy rays (ultraviolet rays; UV) through the light-release type release sheet under the following conditions, and the pressure-sensitive adhesive is applied. The layer was cured to form an adhesive layer after curing. Regarding the adhesive sheet of Example 7, a plastic plate (manufactured by Mitsubishi Gas Chemical Company, Inc.) in which a polymethyl methacrylate resin (PMMA) layer is laminated on a polycarbonate resin (PC) plate on a light peeling type release sheet (manufactured by Mitsubishi Gas Chemical Company, Inc.) "Iupilon sheet MR58U", thickness: 0.7 mm, containing an ultraviolet absorber) was placed on top of each other, and active energy rays were irradiated through the plastic plate. Regarding the pressure-sensitive adhesive in the pressure-sensitive adhesive layer after curing, the gel fraction (after UV irradiation) was derived in the same manner as above. The results are shown in Table 2.

<Activation energy ray irradiation conditions>
・ Uses high-pressure mercury lamp ・ Illuminance 200mW / cm ² , light intensity 2000mJ / cm ²
・ UV illuminance / photometer uses "UVPF-A1" manufactured by iGraphics.

[Test Example 2] (Measurement of total light transmittance)
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheets obtained in Examples, Comparative Examples and Reference Examples was bonded to glass, and this was used as a measurement sample. After performing background measurement with glass, all light rays of the above measurement sample were measured using a haze meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., product name "NDH-5000") in accordance with JIS K7361-1: 1997. The transmittance (%) was measured. The results are shown in Table 2.

[Test Example 3] (Measurement of haze value)
Haze of the adhesive layer of the adhesive sheet obtained in Examples, Comparative Examples and Reference Examples using a haze meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., product name "NDH-5000") according to JIS K7136: 2000. The value (%) was measured. The results are shown in Table 2.

[Test Example 4] (Measurement of L * a * b *)
For the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheets obtained in Examples, Comparative Examples, and Reference Examples, a simultaneous photometric spectroscopic chromaticity meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., product name "SQ2000") was used, and CIE1976L * a * b. * The brightness L *, chromaticity a *, and chromaticity b * defined by the color system were measured. The results are shown in Table 2.

[Test Example 5] (Measurement of adhesive strength)
The light release type release sheet was peeled off from the adhesive sheets obtained in Examples, Comparative Examples and Reference Examples, and the exposed adhesive layer was a polyethylene terephthalate (PET) film having an easy adhesive layer (manufactured by Toyo Boseki Co., Ltd., product name " It was bonded to an easy-adhesive layer of "PET A4300" (thickness: 100 μm) to obtain a laminate of a heavy release type release sheet / adhesive layer / PET film. The obtained laminate was cut into a width of 25 mm and a length of 100 mm, and this was used as a sample.

In an environment of 23 ° C. and 50% RH, the heavy-release type release sheet is peeled off from the above sample, the exposed adhesive layer is attached to soda lime glass (manufactured by Nippon Sheet Glass Co., Ltd.), and then the autoclave manufactured by Kurihara Seisakusho Co., Ltd. is used. The pressure was increased at 0.5 MPa and 50 ° C. for 20 minutes. Then, it was left for 24 hours under the condition of 23 ° C. and 50% RH.

Next, the heavy peeling type release sheet was irradiated with active energy rays under the same conditions as in Test Example 1 to cure the pressure-sensitive adhesive layer to obtain a cured pressure-sensitive adhesive layer. Regarding the adhesive sheet of Example 7, a plastic plate (manufactured by Mitsubishi Gas Chemical Company, product name "Iupilon sheet MR58U", thickness: 0. 7 mm, containing an ultraviolet absorber) was placed on top of each other, and the active energy rays were irradiated through the plastic plate. Further, in Reference Example 1, the state in which the active energy rays were not irradiated was set. Then, using a tensile tester (manufactured by Orientec Co., Ltd., product name "Tencilon"), the adhesive strength (N / 25 mm) was measured under the conditions of a peeling speed of 300 mm / min and a peeling angle of 180 degrees. Conditions other than those described here were measured in accordance with JIS Z0237: 2009. The results are shown in Table 2.

[Test Example 6] (Evaluation of appearance harmony)
The adhesive sheets obtained in Examples, Comparative Examples and Reference Examples were cut into a length of 70 mm × width of 70 mm, and the adhesive layer of the pressure-sensitive adhesive sheet was formed into two soda lime glass plates (manufactured by Nippon Sheet Glass Co., Ltd., length 70 mm × width). It was bonded so as to be sandwiched between 70 mm and 1.1 mm in thickness. Next, one of the soda lime glass plates was irradiated with active energy rays under the same conditions as in Test Example 1 to cure the pressure-sensitive adhesive layer to obtain a cured pressure-sensitive adhesive layer, which was used as a sample. In Reference Example 1, the state in which the active energy rays were not irradiated was set.

The obtained sample was placed on a black printed paper (L *: 29.8, a *: −0.7, b *: 0.6) as a background. Then, whether or not the sample is familiar with the background (has a sense of unity with the background) is visually judged under a three-wavelength fluorescent lamp (distance from the fluorescent lamp: 200 cm), and the appearance is determined according to the following criteria. Harmony was evaluated. The results are shown in Table 2.
⊚: The sample was very familiar to the background.
◯: The sample was familiar to the background to some extent.
X: The sample was clearly unfamiliar with the background.

The color of the paper printed in black (CIE1976L * a * b * L * a * b * defined by the color system) is a spectrophotometer (manufactured by BYK, product name "Spectro-Guide"). ) Is used for measurement.

[Test Example 7] (Evaluation of character visibility)
On a display with a size of 15.6 inches and a resolution of 1366 x 768 (manufactured by Fujitsu Limited, product name "LITEBOOK A574 / H"), white background and black characters (font: MS P Gothic) are 5 to 20 points in size. It was displayed 100% in 1-point increments.

A sample prepared in the same manner as in Test Example 6 was placed on the display. Then, the size of the characters visually recognizable was confirmed at a position 50 cm from the display, and the character visibility was evaluated according to the following criteria. The results are shown in Table 2.
⊚: 8 points of characters could be visually recognized.
◯: The 8-point character was not completely visible, but the 15-point character was visible.
X: The 15-point character could not be visually recognized.

[Test Example 8] (Evaluation of step followability)
On the surface of a glass plate (manufactured by NSG Precision Co., Ltd., product name "Corning Glass Eagle XG", length 90 mm x width 50 mm x thickness 0.5 mm), UV curable ink (manufactured by Teikoku Ink Co., Ltd., product name "POS-911 ink") ) Was screen-printed in a frame shape (outer shape: length 90 mm × width 50 mm, width 5 mm). Next, the printed ultraviolet curable ink is cured by irradiating with ultraviolet rays (80 W / cm ² , 2 metal halide lamps, lamp height 15 cm, belt speed 10 to 15 m / min), and a step (height of the step) due to printing is cured. A stepped glass plate having (5 μm, 10 μm) was produced.

The light release type release sheet is peeled off from the adhesive sheets obtained in Examples, Comparative Examples and Reference Examples, and the exposed adhesive layer is a polyethylene terephthalate (PET) film having an easy adhesive layer (manufactured by Toyobo Co., Ltd., product name "PET". It was bonded to an easy-adhesion layer of "A4300", thickness: 100 μm). Next, the heavy-release type release sheet was peeled off to expose the pressure-sensitive adhesive layer. Then, using a laminator (manufactured by Fujipla, product name "LPD3214"), the laminate was laminated on each stepped glass plate so that the adhesive layer covered the entire surface of the frame-shaped print. Then, it was autoclaved for 20 minutes under the conditions of 50 ° C. and 0.5 MPa, and left at normal pressure at 23 ° C. and 50% RH for 24 hours.

Next, the PET film was irradiated with active energy rays under the same conditions as in Test Example 1 to cure the pressure-sensitive adhesive layer to obtain a cured pressure-sensitive adhesive layer. Regarding the adhesive sheet of Example 7, a plastic plate in which a PMMA layer was laminated on a PC plate on the PET film (manufactured by Mitsubishi Gas Chemical Company, product name "Iupilon sheet MR58U", thickness: 0.7 mm, (Containing an ultraviolet absorber) was placed on top of each other, and active energy rays were irradiated through the plastic plate. Subsequently, it was stored for 72 hours under moist heat conditions of 85 ° C. and 85% RH. After that, the step followability was evaluated based on the following criteria. The step followability is judged to be good when the printed step is completely filled with the cured adhesive layer, and when floating or peeling is observed at the interface between the printed step and the cured adhesive layer, it is judged to be good. , It is judged that the printing step could not be followed. In Reference Example 1, the step followability was evaluated in the same manner as described above except that the active energy rays were not irradiated. The results are shown in Table 2.
⊚: Good at a printing step of 10 μm ○: Good at a printing step of 5 μm ×: There is floating and peeling at a printing step of 5 μm

[Test Example 9] (Evaluation of blister resistance)
The light peeling type peeling sheet was peeled off from the adhesive sheets obtained in Examples, Comparative Examples and Reference Examples, and the exposed adhesive layer was a plastic plate in which a PMMA layer was laminated on a PC plate (manufactured by Mitsubishi Gas Chemical Company, product name " Iupilon sheet MR58U ”, thickness: 0.7 mm, containing an ultraviolet absorber) was affixed to the PC plate side to obtain a plastic plate with an adhesive layer.

The heavy-release type release sheet is peeled off from the plastic plate with the adhesive layer obtained above, and the plastic plate is separated through the exposed adhesive layer into a soda lime glass plate having a size of 70 mm × 150 mm (manufactured by Nippon Sheet Glass Co., Ltd.). , Thickness: 0.7 mm). Then, it was autoclaved for 20 minutes under the conditions of 50 ° C. and 0.5 MPa, and left at normal pressure at 23 ° C. and 50% RH for 24 hours.

Next, the pressure-sensitive adhesive layer was irradiated with active energy rays through a soda lime glass plate under the same conditions as in Test Example 1 to cure the pressure-sensitive adhesive layer to obtain a cured pressure-sensitive adhesive layer. In Example 7 only, the active energy rays were irradiated not through the soda lime glass plate but through the plastic plate. In this way, a structure (70 mm × 150 mm) in which a plastic plate and a glass plate were bonded to each other by an adhesive layer after curing was obtained.

The above components were stored for 72 hours under high temperature and high humidity conditions of 85 ° C. and 85% RH. Then, after curing, the state at the interface between the adhesive layer and the adherend (plastic plate, glass plate) was visually confirmed, and the blister resistance was evaluated according to the following criteria. In Reference Example 1, the blister resistance was evaluated in the same manner as above except that the active energy rays were not irradiated. The results are shown in Table 2.
◎… There were no bubbles, floats, or peeling.
○… There was no floating or peeling, and a few bubbles were generated, but it was at a level that was not a problem.
Δ: There was no floating or peeling, but many bubbles were generated.
×… Floating / peeling occurred.

As can be seen from Table 2, the one using the adhesive sheet obtained in the examples was excellent in appearance harmony and character visibility, as well as in step followability and blister resistance.

The adhesive sheet of the present invention is suitably used, for example, for bonding display body constituent members to each other in a display body having a black frame material, particularly for bonding a protective panel having a step and a desired display body constituent member. can do.

1 ... Adhesive sheet 11 ... Adhesive layer 12a, 12b ... Peeling sheet 2 ... Display 11'... After curing Adhesive layer 21 ... First display component 22 ... Second display component 3 ... Printing layer 4 … Frame material

Claims (15)

An adhesive sheet provided with a colored adhesive layer for adhering one display body component and another display body component.
The colored pressure-sensitive adhesive layer comprises an active energy ray-curable colored pressure-sensitive adhesive.
The haze value of the colored pressure-sensitive adhesive layer is 80% or less.
A pressure-sensitive adhesive sheet having a brightness L * defined by the CIE1976 L * a * b * color system of the colored pressure-sensitive adhesive layer of 95 or less. The pressure-sensitive adhesive sheet according to claim 1, wherein the colored pressure-sensitive adhesive contains a colorant. The pressure-sensitive adhesive sheet according to claim 2, wherein the colorant is a black pigment or dye. The pressure-sensitive adhesive sheet according to claim 2 or 3, wherein the content of the colorant in the color-sensitive adhesive is 0.01% by mass or more and 2.0% by mass or less. The pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein the colored pressure-sensitive adhesive contains a photopolymerization initiator. The colored pressure-sensitive adhesive contains a photopolymerization initiator and
The pressure-sensitive adhesive sheet according to any one of claims 2 to 4, wherein the mass ratio of the amount of the photopolymerization initiator to the amount of the colorant is 0.5 or more and 20 or less. The pressure-sensitive adhesive sheet according to claim 5 or 6, wherein the photopolymerization initiator is a phosphine oxide type. After the colored pressure-sensitive adhesive layer is attached to soda lime glass and irradiated with active energy rays, the adhesive strength of the colored pressure-sensitive adhesive layer to soda lime glass is 10 N / 25 mm or more and 100 N / 25 mm or less. The adhesive sheet according to any one of claims 1 to 7. Two release sheets and
The pressure-sensitive adhesive sheet according to any one of claims 1 to 8, further comprising the colored pressure-sensitive adhesive layer sandwiched between the two release sheets so as to be in contact with the peel-off surfaces of the two release sheets. One display body component and
With other display body components,
A display body including a cured colored pressure-sensitive adhesive layer that adheres the one display body component and the other display body component to each other.
The post-curing colored pressure-sensitive adhesive layer is a post-curing colored pressure-sensitive adhesive layer obtained by subjecting the colored pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to any one of claims 1 to 9 to active energy ray-curing. Display body to do. The tenth aspect of the present invention, wherein at least one of the display body constituent member and the other display body constituent member has a step on the surface on the side to be bonded by the colored pressure-sensitive adhesive layer after curing. Display body. The display body according to claim 10 or 11, wherein at least one of the display body component and the other display body component contains an ultraviolet absorber. The display body according to any one of claims 10 to 12, wherein the display body has a black frame material. A laminate formed by laminating one display body component and another display body component via the colored pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to any one of claims 1 to 9 is produced.
A method for producing a display body, which comprises irradiating the colored pressure-sensitive adhesive layer of the laminated body with active energy rays and curing the colored pressure-sensitive adhesive layer to form a colored pressure-sensitive adhesive layer after curing. A laminate formed by laminating one display body component and another display body component via the colored pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to claim 7 is produced.
The colored pressure-sensitive adhesive layer of the laminated body is irradiated with ultraviolet rays through one display body component containing an ultraviolet absorber, and the colored pressure-sensitive adhesive layer is cured to form a colored pressure-sensitive adhesive layer after curing. A method of manufacturing a characteristic display body.

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