KR20200115066A - Colored adhesive sheet, and display element - Google Patents

Abstract

The present invention relates to a colored adhesive sheet which can improve the design of a display body, and to a display body with improved design. The colored adhesive sheet (1) contains a colored adhesive layer (11) containing a colorant for bonding one display body constituting member and another display body constituting member, wherein the average haze is 1% or more and 60% or less in the colored adhesive sheet (1), and the average haze is an average value of a haze value at wavelength of 780 nm and a haze value at wavelength of 380 nm of the colored adhesive layer (11).

Description

A colored adhesive sheet, and a display body TECHNICAL FIELD [COLORED ADHESIVE SHEET, AND DISPLAY ELEMENT}

The present invention relates to a colored adhesive sheet used to bond a display member constituting member, and a display body using the colored adhesive sheet.

Recent displays (displays), e.g., vehicle instrument panels, car navigation systems, displays for vehicle installations in various instruments installed on consoles, displays such as tablet terminals for general users, commercial In a display body such as a tablet terminal or a digital signage of a computer, and a display body such as an outdoor digital signage, a liquid crystal display device is increasingly used.

As described above, in the display body including the vehicle installation, when the display body is turned off, it may be required to show a sense of unity with a peripheral member of the display body, for example, a frame member, and to improve designability. For this purpose, it is considered to color the display body, and for example, in Patent Documents 1 to 4, inventions relating to the coloration of the display body are disclosed.

Patent Document 1: Japanese Patent Laid-Open No. 2000-313871 Patent Document 2: Japanese Patent Laid-Open No. 2009-188298 Patent Document 3: Japanese Patent Laid-Open No. 2012-234028 Patent Document 4: Japanese Patent Laid-Open No. 2017-57375

However, in the techniques disclosed in Patent Documents 1 to 4, all of the purposes of coloring are different, so that a sense of unity of the peripheral members is provided to the display body, and the designability cannot be improved.

The present invention has been made in view of the above-described realities, and an object of the present invention is to provide a colored adhesive sheet capable of improving the designability of a display body, and a display body having improved designability.

In order to achieve the above object, the first invention is a colored pressure-sensitive adhesive sheet provided with a colored pressure-sensitive adhesive layer made of a pressure-sensitive adhesive containing a colorant for bonding one display member and another display member, the above There is provided a colored pressure-sensitive adhesive sheet characterized in that the average haze, which is an average value of the haze value at a wavelength of 780 nm and a haze value at a wavelength of 380 nm of the colored pressure-sensitive adhesive layer, is 1% or more and 60% or less (Invention 1).

According to the above invention (invention 1), when a colored pressure-sensitive adhesive layer satisfying the above physical properties is applied to a display body, the designability of the display body, in particular, appearance harmony can be improved when the display body is turned off. For example, a sense of unity with peripheral members (especially a black frame material, etc.) can be imparted to the display body.

In the above invention (invention 1), it is preferable that the difference between a haze value at a wavelength of 780 nm and a haze value at a wavelength of 380 nm of the colored pressure-sensitive adhesive layer is 15 points or less (invention 2).

In the above invention (Invention 1 and 2), it is preferable that the standard deviation of the haze value of the colored pressure-sensitive adhesive layer is 5 or less at each wavelength of a 5 nm pitch in a wavelength range of 380 nm to 780 nm (Invention 3).

In the above inventions (Inventions 1 to 3), the total light transmittance of the colored pressure-sensitive adhesive layer is 10% or more and less than 95%, and the chromaticity a* and chromaticity b defined by the CIE1976 L*a*b* color system of the colored pressure-sensitive adhesive layer It is preferable that * is -7-7, respectively (invention 4).

In the above invention (Inventions 1 to 4), the average haze value of the haze value at a wavelength of 780 nm and a haze value at a wavelength of 380 nm of the liquid obtained by diluting the coloring agent 10,000 times with ethyl acetate is 1% or more and 60%. It is preferable that it is the following (invention 5).

In the above inventions (Inventions 1 to 5), it is preferable that the difference between the haze value at a wavelength of 780 nm and a haze value at a wavelength of 380 nm of the liquid obtained by diluting the colorant 10,000 times with ethyl acetate is 30 points or less. (Invention 6).

In the above invention (inventions 1 to 6), it is preferable that the colorant is a black pigment (invention 7).

In the above inventions (inventions 1 to 7), it is preferable that the pressure-sensitive adhesive is an acrylic pressure-sensitive adhesive (invention 8).

In the above inventions (inventions 1 to 8), it is preferable that the pressure-sensitive adhesive is crosslinked with an adhesive composition containing a (meth)acrylic acid ester polymer (A), a crosslinking agent (B), and a colorant (C) (invention 9).

In the above inventions (Inventions 1 to 9), it is preferable to provide two release sheets and the colored pressure-sensitive adhesive layer sandwiched between the release sheets so as to come into contact with the release surfaces of the two release sheets (invention 10).

A second aspect of the present invention is a display body provided with one display member, another display member, and a colored pressure-sensitive adhesive layer for bonding the one display member and the other display member to each other, the A display body characterized in that the colored pressure-sensitive adhesive layer is a colored pressure-sensitive adhesive layer of the colored pressure-sensitive adhesive sheets (inventions 1 to 10) is provided (invention 11).

In the above invention (invention 11), it is preferable that at least one of the one display member constituting member and the other display member constituting member has a level difference on at least a side surface bonded by the colored pressure-sensitive adhesive layer (invention 12). .

In the above invention (invention 11 and 12), it is preferable to have a black frame material (invention 13).

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

1 is a cross-sectional view of a colored adhesive sheet according to an embodiment of the present invention.
2 is a cross-sectional view of a display body according to an embodiment of the present invention.
3 is a plan view of a display body having a frame member according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described.

[Colored adhesive sheet]

The colored pressure-sensitive adhesive sheet according to an embodiment of the present invention includes a colored pressure-sensitive adhesive layer made of a pressure-sensitive adhesive containing a colorant for bonding one display member and another display member, and preferably, the above It is formed by laminating a release sheet on one or both sides of the colored pressure-sensitive adhesive layer. The display body and the display body constituting member will be described later.

A specific configuration as an example of the colored adhesive sheet according to the present embodiment is shown in FIG. 1.

As shown in Fig. 1, the colored pressure-sensitive adhesive sheet 1 is in contact with the two release sheets 12a and 12b and the release surfaces of the two release sheets 12a and 12b. It consists of the colored pressure-sensitive adhesive layer 11 sandwiched between 12a and 12b). In addition, the peeling surface of a release sheet in this specification refers to the surface which has peelability in a peeling sheet, and includes either a peeling-treated surface and a surface exhibiting peelability even if no peeling-processing is performed.

1.Each member

1-1. Colored adhesive layer

The average haze which is the average value of the haze value at a wavelength of 780 nm and a haze value at a wavelength of 380 nm of the colored pressure-sensitive adhesive layer 11 of the colored pressure-sensitive adhesive sheet 1 according to the present embodiment is 1% or more and 60% or less. In addition, the haze value in this specification is a value measured according to JISK7136:2000.

When the colored pressure-sensitive adhesive layer 11 satisfying the above physical properties is applied to a display body, the designability of the display body can be improved when the display body is turned off. As such a design, an example is the appearance harmony at the time of turning off. In this case, the display body can be given a sense of unity with a peripheral member, for example, a black frame material, and thereby, a sense of luxury can be exhibited. Specifically, the average haze is 1% or more, and when the display body is turned off, light incident on the screen of the display body is properly scattered, making it difficult to see the boundary between the display portion and its surrounding members (seamless). I can. This improves the sense of unity between the display body and the peripheral members when the display body is turned off. On the other hand, since the average haze is not more than 60%, when the display body is turned off, whiteness of the display body screen is suppressed, and the sense of unity of the peripheral members is improved. That is, when the average haze is 1% or more and 60% or less, it is possible to provide a sense of unity between the display body and the peripheral members when the display body is turned off, thereby exhibiting an excellent appearance. According to the colored pressure-sensitive adhesive sheet 1 according to the present embodiment, the designability of the display body can be improved in this way.

As the peripheral member, specifically, a dashboard of an automobile with a brightness L* of 23.2, a chromaticity a* of -0.5, and a chromaticity b* of -1.5 as defined by the CIE1976 L*a*b* color system. have. As the color taste of the peripheral member, the brightness L* is 5 to 90, the chromaticity a* is -40 to 40, the chromaticity b* is preferably -40 to 40, and in particular, the brightness L* is 10 to 80, It is preferable that the chromaticity a* is -30 to 30, the chromaticity b* is -30 to 30, and the brightness L* is 15 to 70, the chromaticity a* is -20 to 20, and the chromaticity b* is -20 to It is preferably 20. The colored pressure-sensitive adhesive sheet 1 according to the present embodiment can be suitably used for a display body having a peripheral member having the color taste.

The average haze is required to be 1% or more, preferably 1.5% or more, particularly preferably 1.8% or more, from the viewpoint of making it difficult to see the boundary between the display portion and its surrounding members when the display body is turned off. It is preferably at least 2.2%. On the other hand, the average haze is required to be 60% or less, preferably 45% or less, more preferably 30% or less, especially from the viewpoint of suppressing the whiteness of the display screen when the display is turned off. It is preferably 20% or less, and more preferably 12% or less.

The value (absolute value) of the difference between the haze value at a wavelength of 780 nm and a haze value at a wavelength of 380 nm of the colored pressure-sensitive adhesive layer 11 in this embodiment is preferably 15 points or less, particularly preferably 10 points or less. , And it is preferably 7 points or less. Accordingly, when the colored pressure-sensitive adhesive layer 11 in the present embodiment is applied to a display body, when the display body is lit, the balance of color taste on the screen does not change regardless of the observation position or angle. As a result, when the display body is lit, the visibility of an image/video (wide-angle visibility) when viewed from various angles is improved, and good image quality can be provided.

The lower limit of the difference between the haze values may be 0 points, but from the viewpoint of making it easy to adjust the average haze to a desired value, it is preferably 1 point or more, more preferably 2 points or more, and particularly 3 points. It is preferable that it is above, and it is preferable that it is 4 points or more.

The haze value at a wavelength of 780 nm of the colored pressure-sensitive adhesive layer 11 in the present embodiment is the viewpoint that it becomes easy to adjust the above-described average haze, the difference between the haze value and the standard deviation of the haze value described later to a desired value. In this, it is preferably 0.1 to 50%, more preferably 0.5 to 30%, particularly preferably 0.7 to 20%, and further preferably 1 to 10%.

In addition, the haze value at a wavelength of 380 nm of the colored pressure-sensitive adhesive layer 11 in this embodiment is easy to adjust the above-described average haze, the difference between the haze value and the standard deviation of the haze value described later to a desired value. From the viewpoint of losing, it is preferably 0.1 to 60%, more preferably 1 to 40%, particularly preferably 2 to 30%, further preferably 4 to 20%, and most preferably 5 to 15%. desirable.

At each wavelength (i.e., 380 nm, 385 nm, 390 nm, ..., 775 nm, 780 nm) of a 5 nm pitch in a wavelength range of 380 nm to 780 nm of the colored pressure-sensitive adhesive layer 11 in this embodiment The standard deviation of the haze value of is preferably 5 or less, particularly preferably 3 or less, and further preferably 2 or less. Accordingly, when the colored pressure-sensitive adhesive layer 11 in the present embodiment is applied to a display body, when the display body is lit, the balance of color taste on the screen does not change regardless of the observation position or angle. As a result, when the display body is lit, the visibility of an image/video (wide-angle visibility) when viewed from various angles is improved, and good image quality can be provided.

The lower limit of the standard deviation is most preferably 0, but is usually preferably 0.1 or more, particularly preferably 0.4 or more, and preferably 0.8 or more.

The total light haze value of the colored pressure-sensitive adhesive layer 11 in the present embodiment is preferably 0.1 to 60% from the viewpoint of making it easy to adjust the above-described average haze, the difference between the haze value and the standard deviation to a desired value. And, it is more preferably 0.5 to 40%, particularly preferably 1 to 30%, further preferably 1.5 to 20%, and most preferably 2 to 15%.

The total light transmittance (value measured in accordance with JIS K7361-1: 1997) of the colored pressure-sensitive adhesive layer 11 in this embodiment is preferably 10% or more and less than 95%, and CIE1976 L of the colored pressure-sensitive adhesive layer 11 The chromaticity a* and the chromaticity b* defined by the *a*b* color system are preferably -7 to 7, respectively. In addition, the measurement methods of chromaticity a* and chromaticity b* in this specification are as shown in the test example mentioned later.

When the colored pressure-sensitive adhesive layer 11 satisfies the above optical properties and is applied to a display, the black portion increases when the display is turned off, and the design of the display (for example, appearance harmony when turned off) Can be further improved. Specifically, with respect to the display body, particularly the vehicle-mounted display body, the sense of unity with the peripheral member, for example, a black frame member can be further improved. In addition, since the total light transmittance is 10% or more, the visibility as a display (image/video visibility due to the brightness of the screen) can be ensured satisfactorily.

The upper limit of the total light transmittance is preferably less than 95%, more preferably 90% or less, and particularly 85% from the viewpoint of making it easy to adjust the above-described average haze, the difference between the haze value and the standard deviation to a desired value. It is preferable that it is below, and it is preferable that it is 80% or less. In addition, the lower limit of the total light transmittance is preferably 25% or more, more preferably 40% or more, particularly preferably 50% or more, and further preferably 60% or more from the viewpoint of visibility of the display.

The chromaticity a* is preferably -7 to 7 from the viewpoint of designability of the above-described display body, more preferably -5 to 5, particularly preferably -3 to 3, and further -1 to 1 It is preferable to be. In addition, the chromaticity b* is preferably -7 to 7, more preferably -5 to 5, particularly preferably -3 to 3, and further -1 from the viewpoint of designability of the display body described above. It is preferably ~ 1.

On the other hand, the brightness L* defined by the CIE1976 L*a*b* color system of the colored pressure-sensitive adhesive layer 11 makes it easy to adjust the above-described average haze to 1% or more, making it difficult to see the boundary between the display body and the peripheral member. From a possible viewpoint, it is preferably 99 or less, more preferably 95 or less, particularly preferably 92 or less, and more preferably 91 or less. In addition, the brightness L* makes it easy to adjust the above-described average haze value to 60% or less, thereby suppressing the whiteness of the screen, or making it easy to adjust the difference and standard deviation of the above-described haze value to a desired value. From a possible viewpoint, it is preferably 10 or more, more preferably 25 or more, particularly preferably 50 or more, and more preferably 70 or more, and most preferably 80 or more.

The above optical properties can be achieved by appropriately selecting the kind and content of the colorant contained in the pressure-sensitive adhesive constituting the colored pressure-sensitive adhesive layer 11.

The colorant preferably has a lower limit of average haze, which is an average value of a haze value at a wavelength of 780 nm and a haze value at a wavelength of 380 nm, of a liquid obtained by diluting the colorant 10,000 times with ethyl acetate, of 1% or more, particularly 2 It is preferably at least %, and more preferably at least 3%. In addition, the upper limit of the average haze in the colorant is preferably 60% or less, preferably 40% or less, particularly preferably 30% or less, and further preferably 25% or less. By using such a colorant in an appropriate amount, the average haze of the colored pressure-sensitive adhesive layer 11 is easily satisfied.

In addition, the colorant, the difference between the haze value at a wavelength of 780 nm and a haze value at a wavelength of 380 nm of a liquid obtained by diluting the colorant 10,000 times with ethyl acetate is preferably 30 points or less, and 25 points or less. More preferably, it is more preferably 20 points or less, and more preferably 16 points or less. By using such a colorant in an appropriate amount, the difference between the haze value of the colored pressure-sensitive adhesive layer 11 is easily satisfied.

In addition, the lower limit of the difference between the haze value may be 0 point, but it is easy to adjust the average haze of the above-described colored adhesive layer 11 to 1% or more, or the difference between the haze value of the above-described colored adhesive layer 11 And from the viewpoint of being able to easily adjust the standard deviation to a desired value, it is preferably 0.1 point or more, particularly preferably 0.5 point or more, and more preferably 1 point or more.

The haze value of the liquid obtained by diluting the coloring agent 10,000 times with ethyl acetate at a wavelength of 780 nm is preferably 0.1 to 50%, more preferably 0.5 to 40%, and particularly preferably 1 to 30%, And, it is preferably 2 to 25%. In addition, the haze value of the liquid obtained by diluting the colorant 10,000 times with ethyl acetate at a wavelength of 380 nm is preferably 1 to 60%, more preferably 3 to 50%, and particularly 6 to 40%. It is preferable, and it is preferable that it is 10-30%. As a result, the average haze, the value of the difference between the haze value and the standard deviation of the haze value described later are easily satisfied.

In addition, each wavelength of the liquid obtained by diluting the colorant 10,000 times with ethyl acetate with a 5 nm pitch in the wavelength range of 380 nm to 780 nm (i.e., 380 nm, 385 nm, 390 nm, ..., 775 nm, 780 nm) The standard deviation of the haze value in is preferably 10 or less, more preferably 8 or less, particularly preferably 6 or less, and further preferably 5 or less. The lower limit of the standard deviation is most preferably 0, but usually preferably 0.1 or more, particularly preferably 0.2 or more, and preferably 0.3 or more. Thereby, the standard deviation of the haze value of the above-described colored pressure-sensitive adhesive layer 11 is easily satisfied.

The colorant may be a pigment or a dye. The pigment may be an inorganic pigment or an organic pigment. In terms of durability of the obtained pressure-sensitive adhesive, inorganic pigments are preferred. The color of the colorant can be appropriately selected in accordance with the color of the peripheral member for which a sense of unity is desired, but in general, it is preferably a dark or dark color such as black, brown, dark blue, purple, and blue, and particularly preferably black.

Examples of inorganic pigments include carbon black, cobalt pigment, iron pigment, chromium pigment, titanium pigment, vanadium pigment, zirconium pigment, molybdenum pigment, ruthenium pigment, platinum pigment, ITO (indium pigment). Tin oxide)-based pigments, ATO (antimony tin oxide)-based pigments, and the like.

In addition, as organic pigments and organic dyes, for example, aminium pigments, cyanine pigments, merocyanine pigments, chromium pigments, squarylium pigments, azrenium pigments, polymethine pigments, Naphthoquinone pigments, pyrillium pigments, phthalocyanine pigments, naphthalocyanine pigments, naphtholactam pigments, azo pigments, condensed azo pigments, indigo pigments, perinone pigments, perylene pigments, dioxazine pigments, Quinacridone dye, isoindolinone dye, quinophthalone dye, pyrrole dye, thioindigo dye, metal complex dye (metal complex dye), dithiol metal complex dye, indole phenol dye, triallyl And methane-based dyes, anthraquinone-based dyes, dioxazine-based dyes, naphthol-based dyes, azomethine-based dyes, benzimidazolone-based dyes, pyranthone-based dyes, and srene-based dyes.

Examples of the black pigment include carbon black, copper oxide, iron tetraoxide, manganese dioxide, aniline black, and activated carbon. Moreover, as a black dye, a high-concentration vegetable dye, an azo dye, etc. are mentioned, for example.

The pigments or dyes described above can be suitably mixed and used so as to obtain the desired physical properties from the colored pressure-sensitive adhesive layer 11.

Among the above colorants, carbon black, nigrosine-based black dye and chromate-based black dye are preferable from the viewpoint of being easy to satisfy the above-described physical properties and to easily exhibit the sense of unity of peripheral members. Further, carbon black may or may not be subjected to a predetermined treatment (for example, a hydrophilic treatment) to the surface.

The type of the pressure-sensitive adhesive constituting the colored pressure-sensitive adhesive layer 11 of the colored pressure-sensitive adhesive sheet 1 according to the present embodiment is not particularly limited, and for example, an acrylic pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, a polyurethane-based pressure-sensitive adhesive, and a rubber-based pressure-sensitive adhesive And silicone pressure-sensitive adhesives may be used. Further, the pressure-sensitive adhesive may be an emulsion type, a solvent type, or a solvent-free type, and may be a crosslinked type or a non-crosslinked type. Among these, an acrylic pressure-sensitive adhesive having excellent adhesion properties, optical properties, and the like are preferred.

Moreover, as an acrylic adhesive, an active energy ray-curable thing may be sufficient, and an active energy ray non-curable thing may be sufficient as it. Further, as the acrylic pressure-sensitive adhesive, a crosslinked type is preferable, and a thermally crosslinked type is preferable.

Specifically, the pressure-sensitive adhesive is formed by crosslinking an adhesive composition containing a (meth)acrylic acid ester polymer (A), a crosslinking agent (B) and a colorant (C) (hereinafter sometimes referred to as “adhesive composition P”). It is desirable. Further, when the pressure-sensitive adhesive is used as an active energy ray-curable pressure-sensitive adhesive, it is preferable that the pressure-sensitive adhesive composition P further contains an active energy-ray-curable component (D).

The coloring agent (C) contained in the adhesive composition P is the above-described coloring agent. The pressure-sensitive adhesive obtained from such a pressure-sensitive adhesive composition P can exhibit excellent optical properties, adhesive strength, and durability (step tracking property under high temperature and high humidity conditions). In addition, in this specification, (meth)acrylic acid means both acrylic acid and methacrylic acid. The same goes for other similar terms. In addition, the concept of "copolymer" shall be included in "polymer".

(1) Components of the adhesive composition

(1-1) (meth)acrylic acid ester polymer (A)

It is preferable that the (meth)acrylic acid ester polymer (A) in the present embodiment contains a reactive group-containing monomer having a reactive group reacting with the crosslinking agent (B) in a molecule as a monomer unit constituting the polymer. The reactive group derived from this reactive group-containing monomer reacts with the crosslinking agent (B) to form a crosslinked structure (three-dimensional network structure) to obtain a pressure-sensitive adhesive having a desired cohesive force.

Examples of the reactive group-containing monomer include preferably a monomer having a hydroxyl group in the molecule (a monomer containing a hydroxyl group), a monomer having a carboxyl group in the molecule (a monomer containing a carboxyl group), a monomer having an amino group in the molecule (a monomer containing an amino group), and the like. . Among these, a hydroxyl group-containing monomer or a carboxyl group-containing monomer excellent in reactivity with the crosslinking agent (B) is preferable, and a combination of a hydroxyl group-containing monomer and a carboxyl group-containing monomer is also 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)acrylic acid hydroxyalkyl esters such as 3-hydroxybutyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate. Among them, (meth)acrylic acid hydroxy (meth)acrylic acid having a hydroxyalkyl group having 1 to 4 carbon atoms in terms of the reactivity of the hydroxyl group of the obtained (meth)acrylic acid ester polymer (A) with the crosslinking agent (B) and copolymerization with other monomers. Alkyl esters are preferred. Specifically, for example, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and the like are preferably mentioned, and in particular, 2-hydroxyethyl acrylate or 4-hydroxybutyl acrylate Are preferably mentioned. These may be used alone or in combination of two or more.

As a carboxyl group-containing monomer, ethylenically unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid, are mentioned, for example. Among them, acrylic acid is preferred from the viewpoint of reactivity of the carboxyl group of the obtained (meth)acrylic acid ester polymer (A) with the crosslinking agent (B) and copolymerization with other monomers. These may be used alone or in combination of two or more.

As an amino group-containing monomer, aminoethyl (meth)acrylate, n-butylaminoethyl (meth)acrylate, etc. are mentioned, for example. 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 of 1% by mass or more as a monomer unit constituting the polymer, more preferably 5% by mass or more, and particularly 10 It is preferable to contain it in mass% or more. In addition, since the dispersibility of the colorant (C) in the pressure-sensitive adhesive tends to become more favorable, it is more preferable to contain 12 mass% or more, and most preferably contain 15 mass% or more. On the other hand, the (meth)acrylic acid ester polymer (A) preferably contains a reactive group-containing monomer as an upper limit of 35% by mass or less, more preferably 30% by mass or less, as a monomer unit constituting the polymer, It is particularly preferable to contain 20% by mass or less. Moreover, it is more preferable to contain 18 mass% or less from the point which the dispersibility of the coloring agent (C) in an adhesive tends to become more favorable. When the (meth)acrylic acid ester polymer (A) contains a reactive group-containing monomer in the above amount as a monomer unit, a good crosslinked structure is formed in the obtained pressure-sensitive adhesive to obtain a desired cohesive strength. Further, the dispersibility of the colorant (C) in the pressure-sensitive adhesive tends to be good, and the resulting pressure-sensitive adhesive has good reproducibility and uniformity of the optical properties described above, and exhibits excellent design properties and visibility. Further, in the case where the reactive group-containing monomer is a hydroxyl group-containing monomer, the content is particularly preferably 15% by mass or more. In this case, a predetermined amount of hydroxyl groups remain in the adhesive. The hydroxyl group is a hydrophilic group, and if such a hydrophilic group is present in the pressure-sensitive adhesive in a predetermined amount, even when the pressure-sensitive adhesive is placed under high temperature and high humidity conditions, compatibility with moisture infiltrating the adhesive under the high temperature and high humidity conditions is good, and as a result, When returned to room temperature and humidity, whitening of the pressure-sensitive adhesive is suppressed (excellent moisture-heat whitening resistance).

In addition, it is preferable that the (meth)acrylic acid ester polymer (A) does not contain a carboxyl group-containing monomer as a monomer unit constituting the polymer. Since the carboxyl group is an acid component, it does not contain a carboxyl group-containing monomer, so that a defect is caused by an acid on the adhesive object, for example, a transparent conductive film such as tin-doped indium oxide (ITO), or Even when a metal film or the like is present, these defects (corrosion, change in resistance value, etc.) caused by acid can be suppressed. However, it is allowed to contain a predetermined amount of the carboxyl group-containing monomer to the extent that such defects do not occur. Specifically, it is permissible to contain a carboxyl group-containing monomer as a monomer unit in an amount of 0.1% by mass or less, preferably 0.01% by mass or less, more preferably 0.001% by mass or less in the (meth)acrylic acid ester polymer (A). do.

It is preferable that the (meth)acrylic acid ester polymer (A) contains a (meth)acrylic acid alkyl ester as a monomer unit constituting the polymer. Thereby, good adhesiveness can be expressed. The alkyl group may be linear or branched.

As the (meth)acrylic acid alkyl ester, (meth)acrylic acid alkyl ester having 1 to 20 carbon atoms of the alkyl group is preferable from the viewpoint of adhesiveness and dispersibility of the colored ring (C). Examples of (meth)acrylate alkyl esters having 1 to 20 carbon atoms in the alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, (meth) Acrylic acid n-pentyl, (meth) acrylic acid n-hexyl, (meth) acrylic acid 2-ethylhexyl, (meth) acrylic acid isooctyl, (meth) acrylic acid n-decyl, (meth) acrylic acid n-dodecyl, (meth) acrylic acid Myristyl, palmityl (meth)acrylate, stearyl (meth)acrylate, and the like. Among them, from the viewpoint of further improving the adhesiveness, (meth)acrylic acid ester having 1 to 8 carbon atoms of the alkyl group is preferable, and methyl (meth)acrylate, n-butyl (meth)acrylate or 2-ethylhexyl (meth)acrylate This is particularly preferred, and methyl methacrylate, n-butyl acrylate, or 2-ethylhexyl acrylate is more preferred. Moreover, these may be used individually or may be used in combination of 2 or more types.

The (meth)acrylic acid ester polymer (A) preferably contains 50% by mass or more, particularly preferably 60% by mass or more, and 65% by mass as a monomer unit constituting the polymer. It is preferable to contain at least %. If the lower limit of the content of the (meth) acrylic acid alkyl ester is the above, the (meth) acrylic acid ester polymer (A) can exhibit suitable adhesiveness. Further, there is a tendency that the dispersibility of the colorant (C) in the pressure-sensitive adhesive can be improved, and the (meth)acrylic acid ester polymer (A) does not impair the desired adhesion. Thereby, the obtained adhesive can exhibit suitable adhesiveness, and the reproducibility and uniformity of the optical properties described above are good, and excellent designability and visibility are exhibited. On the other hand, the (meth)acrylic acid ester polymer (A) preferably contains 99% by mass or less, more preferably 95% by mass or less, and in particular contains (meth) acrylate alkyl ester as a monomer unit constituting the polymer. It is preferable to contain 90 mass% or less, and it is preferable to contain 85 mass% or less. If the upper limit of the content of the (meth) acrylic acid alkyl ester is the above, a suitable amount of other monomer components such as a reactive functional group-containing monomer can be introduced into the (meth) acrylic acid ester polymer (A).

It is also preferable that the (meth)acrylic acid ester polymer (A) contains a monomer having an alicyclic structure in a molecule (a monomer containing an alicyclic structure) as a monomer unit constituting the polymer. Since the alicyclic structure-containing monomer has a large volume, it is estimated that the gap between the polymers is widened by presenting it in the polymer, and the obtained pressure-sensitive adhesive can be made excellent in flexibility. Thereby, the pressure-sensitive adhesive becomes excellent in level difference followability.

The alicyclic structure carbocyclic ring in the alicyclic structure-containing monomer may have a saturated structure or may have an unsaturated bond in part. Further, the alicyclic structure may be a monocyclic alicyclic structure, or a polycyclic alicyclic structure such as bicyclic or tricyclic. It is preferable that the alicyclic structure is a polycyclic alicyclic structure (polycyclic structure) from the viewpoint of making the obtained (meth)acrylic acid ester polymer (A) appropriate for each other, and imparting high stress relaxation property by an adhesive. Do. Further, in consideration of the compatibility of the (meth)acrylic acid ester polymer (A) with other components, the polycyclic structure is particularly preferably bicyclic to tetracyclic. In addition, from the viewpoint of imparting stress relaxation properties 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 in the case where a plurality of rings exist independently, refers to the total number of carbon atoms) , Usually, it is 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 as described above, from the viewpoint of compatibility, it is preferably 15 or less, and particularly preferably 10 or less.

As the alicyclic structure-containing monomer, specifically, (meth) acrylate cyclohexyl, (meth) acrylate dicyclopentanyl, (meth) acrylate adamantyl, (meth) acrylate isobornyl, (meth) acrylate dicyclophene Tenyl, dicyclopentenyloxyethyl (meth)acrylate, and the like. Among them, dicyclopentanyl (meth)acrylic acid (carbon number of alicyclic structure: 10) and (meth)acrylic acid exhibiting more excellent step-following properties. Adamantyl (carbon number of the alicyclic structure: 10) or isobornyl (meth)acrylate (the number of carbon atoms of the alicyclic structure: 7) is preferred, particularly isobornyl (meth)acrylate, and isobornyl acrylate is preferred. . These may be used individually by 1 type, and may be used in combination of 2 or more types.

When the (meth)acrylic acid ester polymer (A) contains an alicyclic structure-containing monomer as a monomer unit constituting the polymer, it is preferable to contain 1% by mass or more of the alicyclic structure-containing monomer, and in particular 4% by mass It is preferable to contain it above, and it is preferable to contain it more than 8 mass %. In addition, the (meth)acrylic acid ester polymer (A) preferably contains 30% by mass or less of alicyclic structure-containing monomer as a monomer unit constituting the polymer, particularly preferably 22% by mass or less, and 14 It is preferable to contain it by mass% or less. When the content of the alicyclic structure-containing monomer is within the above range, the obtained pressure-sensitive adhesive has more excellent step-following properties and more excellent adhesive strength to plastics.

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 presenting a nitrogen atom-containing monomer as a constituent unit in the polymer, a predetermined polarity is imparted to the pressure-sensitive adhesive, and the affinity can be made excellent even for an adherend having a certain degree of polarity such as glass. As the nitrogen atom-containing monomer, a monomer having a nitrogen-containing heterocycle is preferable from the viewpoint of giving the (meth)acrylic acid ester polymer (A) appropriate rigidity. In addition, from the viewpoint of increasing the degree of freedom of the part derived from the nitrogen atom-containing monomer in the higher-order structure of the pressure-sensitive adhesive to be constituted, the nitrogen atom-containing monomer is one polymerization used in polymerization to form the (meth)acrylic acid ester polymer (A) It is preferable not to contain a reactive unsaturated double bond group other than a sexual group.

As a monomer having a nitrogen-containing heterocycle, for example, N-(meth)acryloylmorpholine, N-vinyl-2-pyrrolidone, N-(meth)acryloylpyrrolidone, N-(meth) Acryloylpiperidine, N-(meth)acryloylpyrrolidine, N-(meth)acryloylaziridine, aziridinylethyl (meth)acrylate, 2-vinylpyridine, 4-vinylpyridine, 2- Vinylpyrazine, 1-vinylimidazole, N-vinylcarbazole, N-vinyl phthalimide, and the like, and among them, N-(meth)acryloylmorpholine, which exhibits more excellent adhesion, is preferable, In particular, N-acryloylmorpholine is preferred. These may be used individually by 1 type, and may be used in combination of 2 or more types.

When the (meth)acrylic acid ester polymer (A) contains a nitrogen atom-containing monomer as a monomer unit constituting the polymer, it is preferable to contain 1% by mass or more of the nitrogen atom-containing monomer, and particularly 4% by mass or more. It is preferable to do, and it is preferable to contain 8 mass% or more. In addition, the (meth)acrylic acid ester polymer (A) preferably contains 20% by mass or less of the nitrogen atom-containing monomer as a monomer unit constituting the polymer, particularly preferably 16% by mass or less, and 12 It is preferable to contain it 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 exhibit excellent adhesion 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 even in order not to impede the above-described action of the reactive functional group-containing monomer. Examples of such monomers include (meth)acrylate 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.

It is preferable that the (meth)acrylic acid ester polymer (A) is a linear polymer. Since it is a straight-chain polymer, entanglement of molecular chains is likely to occur, and cohesive strength can be expected to be improved.Therefore, the storage modulus, gel fraction, and adhesive strength of the obtained pressure-sensitive adhesive tend to be suitable, and the level difference tracking property under high temperature and high humidity conditions It becomes excellent.

In addition, it is preferable that the (meth)acrylic acid ester polymer (A) is a solution polymerized product obtained by a solution polymerization method. Since it is a solution polymer, it is easy to obtain a polymer of high molecular weight, and an improvement in cohesive force can be expected, so that the storage modulus, gel fraction, and adhesive strength of the obtained pressure-sensitive adhesive tend to be suitable, and the level difference followability under high temperature and high humidity conditions becomes excellent. .

The polymerization form 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 as a lower limit, particularly preferably 300,000 or more, and further preferably 400,000 or more, and from the viewpoint of dispersibility of the colorant (C), It is more preferably 500,000 or more, and particularly preferably 700,000 or more. If the lower limit of the weight average molecular weight of the (meth)acrylic acid ester polymer (A) is the above, the storage elastic modulus, gel fraction, and adhesive strength of the obtained pressure-sensitive adhesive tend to be suitable, and the step followability under high temperature and high humidity conditions becomes more excellent. In addition, there is a tendency that the dispersibility of the colorant (C) in the pressure-sensitive adhesive can be improved, and therefore, the resulting pressure-sensitive adhesive has good reproducibility and uniformity of the optical properties described above, and exhibits excellent design properties and visibility.

In addition, the weight average molecular weight of the (meth)acrylic acid ester polymer (A) is preferably 2 million or less as an upper limit, particularly preferably 1.5 million or less, and more preferably 1 million or less. If the upper limit of the weight average molecular weight of the (meth)acrylic acid ester polymer (A) is the above, the storage elastic modulus, gel fraction, and adhesive force of the obtained pressure-sensitive adhesive tend to be suitable, and the initial step followability becomes more excellent. In addition, the weight average molecular weight in this specification is a standard polystyrene conversion value measured according to a gel permeation chromatography (GPC) method.

Moreover, in the adhesive composition P, the (meth)acrylic acid ester polymer (A) may be used individually by 1 type, and may be used in combination of 2 or more types.

(1-2) crosslinking agent (B)

The crosslinking agent (B) crosslinks the (meth)acrylic acid ester polymer (A) by heating the adhesive composition P, so that a three-dimensional network structure can be formed satisfactorily. Thereby, the cohesive force of the obtained pressure-sensitive adhesive is improved, and the level difference followability under high temperature and high humidity conditions becomes excellent.

The crosslinking agent (B) may be any one that reacts with a reactive group possessed by the (meth)acrylic acid ester polymer (A). For example, an isocyanate crosslinking agent, an epoxy crosslinking agent, an amine crosslinking agent, a melamine crosslinking agent, an aziridine crosslinking agent, hydrazine Crosslinking agents, aldehyde crosslinking agents, oxazoline crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, and ammonium salt crosslinking agents. 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 crosslinking agent having excellent reactivity with a hydroxyl group, and the reactive group of the (meth)acrylic acid ester polymer (A) is a carboxyl group In the case of, it is preferable to use an epoxy-based crosslinking agent excellent in reactivity with a carboxyl group. In addition, crosslinking agent (B) can be used individually by 1 type or in combination of 2 or more types.

The isocyanate crosslinking 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 diisocyanate, and hydrogenated diisocyanate. Alicyclic polyisocyanates such as phenylmethane diisocyanate, etc., and their biuret body, isocyanurate body, and low-molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor oil, etc. The adduct body etc. which are reactants of are mentioned. Among them, from the viewpoint of reactivity with a hydroxyl group, trimethylolpropane-modified aromatic polyisocyanates, particularly trimethylolpropane-modified tolylene diisocyanate and trimethylolpropane-modified xylylene diisocyanate are preferred.

Examples of the epoxy crosslinking agent include 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-xylylene Diamine, ethylene glycol diglycidyl ether, 1,6-hexane diol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl aniline, diglycidylamine, etc. are mentioned. Among them, 1,3-bis(N,N-diglycidylaminomethyl) cyclohexane is preferable from the viewpoint of reactivity with a carboxyl group.

The content of the crosslinking agent (B) in the adhesive composition P is preferably 0.01 parts by mass or more, particularly preferably 0.05 parts by mass or more, and 0.1 parts by mass or more with respect to 100 parts by mass of the (meth)acrylic acid ester polymer (A). It is desirable. Further, 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. When the content of the crosslinking agent (B) is in the above range, the obtained pressure-sensitive adhesive exhibits good cohesive strength, it is easy to satisfy the desired storage modulus, gel fraction, adhesive strength, etc., and the step followability under high temperature and high humidity conditions becomes more excellent.

(1-3) Colorant (C)

The coloring agent (C) is the above-described coloring agent. The specific type is as described above.

The content of the coloring agent (C) with respect to 100 parts by mass of the (meth)acrylic acid ester polymer (A) is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, particularly preferably 0.1 parts by mass or more, and further 0.2 It is preferably not less than parts by mass. Further, the content is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, particularly preferably 2 parts by mass or less, and further preferably 1 part by mass or less. When the content of the colorant (C) is in the above range, it becomes easy to satisfy the aforementioned optical properties.

(1-4) Active energy ray-curable component (D)

In an active energy ray-cured adhesive formed by crosslinking the adhesive composition P, the active energy ray-curable component (D) is polymerized with each other, and the polymerized active energy ray-curable component (D) is a (meth)acrylic acid ester polymer (A It is assumed that it is attached to the crosslinked structure (three-dimensional network structure). The pressure-sensitive adhesive having such a high-order structure exhibits very excellent durability, and becomes particularly excellent in step followability under high temperature and high humidity conditions.

The active energy ray-curable component (D) is not particularly limited as long as it is a component in which the above effects are obtained by curing by irradiation with active energy rays, and may be any one of a monomer, an oligomer, or a polymer, or a mixture thereof. Among them, a polyfunctional acrylate monomer having more excellent blister resistance is preferably mentioned.

As a polyfunctional acrylate monomer, for example, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol Di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, hydroxypibarate neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, tricyclodecanedimethanol ( Meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphoric acid di(meth)acrylate, di(acryloxyethyl) isocyanurate, allylated cyclohexyl di(meth) Bifunctional types such as acrylate, ethoxylated bisphenol A diacrylate, and 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene; Trimethyrolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethyrolpropane Trifunctional types such as tri(meth)acrylate, tris(acryloxyethyl) isocyanurate, and ε-caprolactone-modified tris-(2-(meth)acryloxyethyl) isocyanurate; Tetrafunctional types such as diglycerin tetra(meth)acrylate and pentaerythritol tetra(meth)acrylate; 5-functional types, such as propionic acid-modified dipentaerythritol penta (meth) acrylate; 6-functional types, such as dipentaerythritol hexa(meth)acrylate and caprolactone-modified dipentaerythritol hexa(meth)acrylate, etc. are mentioned. These may be used individually by 1 type, and may be used in combination of 2 or more types. In addition, 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 blister resistance of the obtained pressure-sensitive adhesive, di(acryloxyethyl) isocyanurate, tris(acryloxyethyl) isocyanurate, and ε-caprolactone-modified tris-(2-(meth)acryloxy A polyfunctional acrylate monomer containing an isocyanurate structure in a molecule such as ethyl) isocyanurate, or a cyclic structure (especially a cycloalkane structure) in a molecule such as tricyclodecanedimethanol (meth)acrylate The polyfunctional acrylate monomer is preferably a polyfunctional acrylate monomer having a trifunctional or higher function, and a polyfunctional acrylate monomer having an isocyanurate structure in the molecule, or a bifunctional or higher polycyclic structure (especially of a cycloalkane A polyfunctional acrylate monomer containing polycyclic structure) is more preferable, and ε-caprolactone-modified tris-(2-(meth)acryloxyethyl) isocyanurate or tricyclodecanedimethanol (meth)acrylate is Particularly preferred, ε-caprolactone-modified tris-(2-acryloxyethyl) isocyanurate or tricyclodecanedimethanol acrylate is more preferred, and ε-caprolactone-modified tris-(2-acryloxyethyl) iso Most preferred is cyanurate.

The content of the active energy ray-curable component (D) in the adhesive composition P is 100 parts by mass of the (meth)acrylic acid ester polymer (A) from the viewpoint of making the pressure-sensitive adhesive after active energy ray curing more excellent in step-following properties under high temperature and high humidity conditions. With respect to, as the lower limit, it is preferably 1 part by mass or more, particularly preferably 3 parts by mass or more, and more preferably 4 parts by mass or more. On the other hand, the above content is preferably 20 parts by mass or less, particularly preferably 12 parts by mass or less, and more preferably 8 parts by mass or less as an upper limit from the viewpoint of the adhesive strength of the pressure-sensitive adhesive after curing with active energy rays.

(1-5) Photopolymerization initiator (E)

When using ultraviolet rays as an active energy ray for curing the adhesive composition P, it is preferable that the adhesive composition P further contains a photopolymerization initiator (E). By containing the photoinitiator (E) in this way, the active energy ray-curable component (D) can be efficiently polymerized, and the polymerization curing time and the irradiation amount of the active energy ray can be reduced.

As such a photoinitiator (E), for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylamino Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydro Roxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan 1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2 -Propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiary-butylanthraquinone, 2-aminoanthraquinone, 2-methyl thioxanthone, 2-ethyl thioxanthone, 2-chloro thioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, 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)-phenyl phosphine oxide, etc. are mentioned. These may be used alone or in combination of two or more.

Among the above, a phosphine oxide-based photopolymerization initiator is preferred because it is easy to decompose and reliably cure the pressure-sensitive adhesive even when irradiated with ultraviolet rays beyond a plastic plate containing an ultraviolet absorber. Specifically, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenyl phosphine oxide, and the like are preferable.

The content of the photoinitiator (E) in the adhesive composition P is preferably 0.1 parts by mass or more as a lower limit, particularly preferably 1 part by mass or more, and 5 parts by mass, based on 100 parts by mass of the active energy ray-curable component (D). It is preferably more than one part. Moreover, it is preferable that it is 30 mass parts or less as an upper limit, especially it is preferable that it is 20 mass parts or less, and it is preferable that it is 12 mass parts or less.

The mass ratio of the amount of the photopolymerization initiator (E) to the amount of the colorant (C) (photoinitiator (E) / colorant (C)) is preferably 0.01 or more, particularly preferably 0.1 or more, and further preferably 0.2 or more. . Further, the mass ratio is preferably 5 or less, particularly preferably 3 or less, and further preferably 1 or less. Since the ratio of the amount of the photopolymerization initiator (E) to the amount of the colorant (C) is in the above range, it is easy to obtain a pressure-sensitive adhesive having suitable cohesive strength or tackiness by curing with active energy rays while satisfying the optical properties described above. , It is easy to become more excellent in step followability under high temperature and high humidity conditions.

(1-6) Various additives

To the adhesive composition P, as desired, various additives commonly used in acrylic adhesives, such as silane coupling agents, rust inhibitors, ultraviolet absorbers, antistatic agents, tackifiers, antioxidants, light stabilizers, softeners, refractive index adjusters, etc. are added. can do. In addition, it is assumed that the polymerization solvent and the diluting solvent described later are not included in the additive constituting the adhesive composition P.

It is preferable that the adhesive composition P contains a silane coupling agent among the above. Thereby, even if the adherend is a plastic plate or a glass member, the adhesion with the adherend is improved, and the level difference tracking property under high temperature and high humidity conditions becomes more excellent.

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

Examples of such silane coupling agents include silicon compounds containing polymerizable unsaturated groups such as vinyl trimethoxysilane, vinyl triethoxysilane, and methacryloxypropyltrimethoxysilane, and 3-glycidoxypropyltrimethoxysilane. Silicon compounds having an epoxy structure such as silane, 2-(3,4-epoxycyclohexyl) ethyl trimethoxysilane, 3-mercaptopropyl trimethoxysilane, 3-mercaptopropyl triethoxysilane, 3-mer Mercapto group-containing silicon compounds such as captopropyl dimethoxymethyl silane, 3-aminopropyl trimethoxysilane, N-(2-aminoethyl)-3-aminopropyl trimethoxysilane, N-(2-aminoethyl) Amino group-containing silicon compounds such as -3-aminopropyl methyl dimethoxy silane, 3-chloropropyl trimethoxysilane, 3-isocyanate propyl triethoxysilane, or at least one of these and methyl triethoxysilane, ethyl triethoxy Condensates with alkyl group-containing silicon compounds, such as silane, methyl trimethoxysilane, ethyl trimethoxysilane, etc. are mentioned. These may be used individually by 1 type, and may be used in combination of 2 or more types.

The content of the silane coupling agent in the adhesive composition P is preferably 0.01 parts by mass or more, particularly preferably 0.05 parts by mass or more, and also 0.1 parts by mass or more with respect to 100 parts by mass of the (meth)acrylic acid ester polymer (A). desirable. Further, the content is preferably 1 part by mass or less, particularly preferably 0.5 part by mass or less, and further preferably 0.3 parts by mass or less.

(2) Preparation of adhesive composition

The adhesive composition P mixes the (meth)acrylic acid ester polymer (A) obtained by preparing the (meth)acrylic acid ester polymer (A), the crosslinking agent (B) and the colorant (C), and optionally, an active energy ray-curable component It can be manufactured by adding (D), a photoinitiator (E), an additive, etc.

The (meth)acrylic acid ester polymer (A) can be produced by polymerizing a mixture of monomers constituting the polymer by a conventional radical polymerization method. The polymerization of the (meth)acrylic acid ester polymer (A) is preferably performed according to a solution polymerization method using a polymerization initiator as desired. However, the present invention is not limited to this and may be polymerized with no solvent. As a polymerization solvent, ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, methyl ethyl ketone, etc. are mentioned, for example, and two or more types may be used together.

Examples of the polymerization initiator include an azo compound, an organic peroxide, and the like, and two or more types may be used in combination. As an azo compound, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane 1- Carbonitrile), 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], etc. are mentioned.

As an organic peroxide, for example, benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropylperoxydicarbonate, di-n-propylperoxydicarbonate, di(2-ethoxyethyl)peroxydi Carbonate, t-butylperoxyneodecanoate, t-butylperoxypivalate, (3,5,5-trimethylhexanoyl)peroxide, dipropionyl peroxide, diacetyl peroxide, and the like.

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

When the (meth)acrylic acid ester polymer (A) is obtained, in a solution of the (meth)acrylic acid ester polymer (A), a crosslinking agent (B), a colorant (C), and optionally a diluted solvent, an active energy ray-curable component (D) ), a photopolymerization initiator (E), an additive, and the like are added, and sufficiently mixed to obtain an adhesive composition P (coating solution) diluted with a solvent. In addition, in the case of using a solid one in any of the above components, or in the case of causing precipitation when mixing with other components in an undiluted state, the component alone is previously dissolved or diluted in a dilute solvent, You may mix it 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, butanol, and 1-meth. Alcohol such as oxy-2-propanol, acetone, methyl ethyl ketone, 2-pentanone, isophorone, ketones such as cyclohexanone, esters such as ethyl acetate and butyl acetate, cellosolve solvents such as ethyl cellosolve, etc. Is used.

The concentration and viscosity of the coating solution thus prepared may be within a range that can be coated, and is not particularly limited, and can be appropriately selected depending on the situation. For example, it is diluted so that the concentration of the adhesive composition P becomes 10-60 mass %. In addition, when obtaining a coating solution, addition of a diluting solvent etc. is not a necessary condition, and it is not necessary to add a diluting solvent as long as it is a viscosity that can coat the adhesive composition P. In this case, the adhesive composition P becomes a coating solution using the polymerization solvent of the (meth)acrylic acid ester polymer (A) as a diluting solvent.

(3) Formation of colored adhesive layer

The colored pressure-sensitive adhesive layer 11 in this embodiment is preferably made of a pressure-sensitive adhesive obtained by crosslinking the pressure-sensitive adhesive composition P (the applied layer). Crosslinking of the adhesive composition P can usually be performed by heat treatment. In addition, this heat treatment can also serve as a drying treatment when volatilizing a diluted solvent or the like from the coating layer of the adhesive composition P applied to a desired object.

The heating temperature of the heat treatment is preferably 50 to 150°C, and particularly preferably 70 to 120°C. In addition, 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 (eg, 23° C., 50%RH). When this curing period is required, after the curing period has elapsed, and when the curing period is unnecessary, after the heat treatment is completed, the adhesive is formed.

The (meth)acrylic acid ester polymer (A) is sufficiently crosslinked through the crosslinking agent (B) by the above heat treatment (and curing). The pressure-sensitive adhesive obtained in this way tends to satisfy a desired storage modulus, gel fraction, adhesive strength, and the like, and becomes excellent in step followability under high temperature and high humidity conditions.

(4) Physical properties of adhesive

It is preferable that the adhesive of this embodiment has the following physical properties.

(4-1) gel fraction

In this embodiment, the lower limit of the gel fraction of the pressure-sensitive adhesive is preferably 20% or more, more preferably 40% or more, particularly preferably 50% or more, and still more preferably 60% or more. If the lower limit of the gel fraction of the pressure-sensitive adhesive is the above, the cohesive strength of the pressure-sensitive adhesive becomes high, and the level difference tracking property under high temperature and high humidity conditions becomes more excellent. In addition, the gel fraction of the pressure-sensitive adhesive according to the present embodiment is preferably 100% or less as an upper limit, more preferably 90% or less, particularly preferably 80% or less, and further preferably 70% or less. 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 followability and the step followability under high temperature and high humidity conditions are excellent. Moreover, good adhesive force is expressed, and the adhesiveness with an adherend becomes more excellent.

Here, the measuring method of the gel fraction of an adhesive is as shown in the test example mentioned later. In the case of an active energy ray-curable adhesive, it is assumed that it is the gel fraction of the adhesive after curing with an active energy ray. In addition, in the case of an active energy ray-curable adhesive, the gel fraction of the adhesive before curing with an active energy ray is preferably 20 to 70%, and in particular, 30 to 60%, from the viewpoint of improving the initial step followability. It is preferable, and it is more preferable that it is 40-55%.

(4-2) storage modulus

The storage modulus at 23° C. of the pressure-sensitive adhesive according to the present embodiment is preferably 0.001 MPa or more, more preferably 0.01 MPa or more, and particularly preferably 0.05 MPa or more, and further preferably 0.1 MPa or more as a lower limit. When the lower limit of the storage elastic modulus is as described above, the step tracking property under high temperature and high humidity conditions is excellent. In addition, the storage modulus is preferably 2 MPa or less as an upper limit, more preferably 1 MPa or less, particularly preferably 0.8 MPa or less, further preferably 0.4 MPa or less, and most preferably 0.2 MPa or less. When the upper limit of the storage elastic modulus is the above, the initial step followability and the step followability under high temperature and high humidity conditions are excellent.

Here, the storage modulus in this specification is a value measured according to the torsional shear method at a measurement frequency of 1 Hz in accordance with JIS K7244-6. Specifically, it is as shown in the test example mentioned later. In the case of an active energy ray-curable adhesive, it is assumed that it is the storage modulus of the adhesive after curing with an active energy ray. In addition, in the case of an active energy ray-curable adhesive, the storage modulus of the adhesive before curing with an active energy ray is preferably 0.01 to 1 MPa, and in particular, 0.02 to 0.5 MPa, from the viewpoint of improving the initial step followability. It is preferable, and it is more preferable that it is 0.04 to 0.1 MPa.

(5) thickness of colored adhesive layer

As the lower limit, the thickness of the colored pressure-sensitive adhesive layer 11 is preferably 1 μm or more, more preferably 2 μm or more, and particularly preferably 4 μm or more. If the lower limit of the thickness of the colored pressure-sensitive adhesive layer 11 is the above, the above-described optical properties are likely to be satisfied in relation to the content of the coloring agent (C), and a desired adhesive force is easily exhibited. In addition, from the viewpoint of making it easy to exhibit excellent step-following properties, the lower limit is preferably 10 μm or more, more preferably 20 μm or more, particularly preferably 50 μm or more, and even more preferably 80 μm or more.

On the other hand, the thickness of the colored pressure-sensitive adhesive layer 11 is preferably 500 μm or less, more preferably 300 μm or less, particularly preferably 200 μm or less, and further preferably 150 μm or less as an upper limit. If the upper limit of the thickness of the colored pressure-sensitive adhesive layer 11 is the above, workability becomes good, and appearance defects due to pressing marks and the like are less likely to occur. Further, in relation to the content of the colorant (C), the above-described optical properties are likely to be satisfied. Further, the colored 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 sheet

The release sheets 12a and 12b protect the colored pressure-sensitive adhesive layer 11 until the colored pressure-sensitive adhesive sheet 1 is used, and are peeled when the colored pressure-sensitive adhesive sheet 1 (colored pressure-sensitive adhesive layer 11) is used. . In the colored adhesive sheet 1 according to the present embodiment, one or both of the release sheets 12a and 12b are not necessarily required.

As the release sheets 12a, 12b, for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene Naphthalate film, polybutylene terephthalate 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, poly Carbonate film, polyimide film, fluororesin film, etc. are used. Moreover, these crosslinked films are also used. Moreover, these laminated films may be sufficient.

It is preferable that the peeling treatment is performed on the peeling surface (particularly the surface in contact with the colored pressure-sensitive adhesive layer 11) of the peeling sheets 12a and 12b. Examples of the release agent used in the release treatment include alkyd, silicone, fluorine, unsaturated polyester, polyolefin, and wax release agents. In addition, it is preferable that one of the release sheets 12a and 12b be used as a medium-release type release sheet having a large peeling force, and the other release sheet be used as a light-release type release sheet having a small peeling force.

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

2. Physical properties (adhesion)

The adhesive force of the colored pressure-sensitive adhesive sheet 1 according to the present embodiment to the soda lime glass is preferably 1 N/25 mm or more, more preferably 2 N/25 mm or more, and 4 N/25 mm or more as a lower limit. It is particularly preferable, and it is more preferably 8 N/25 mm or more. If the lower limit of the adhesive force is the above, the step followability under high temperature and high humidity conditions becomes more excellent. In addition, the adhesive strength of the colored pressure-sensitive adhesive sheet 1 according to the present embodiment to the soda lime glass is preferably 80 N/25 mm or less, more preferably 50 N/25 mm or less, and 30 N/25 as an upper limit. It is particularly preferred that it is mm or less. If the upper limit of the adhesive force is the above, when good rework properties are obtained and a bonding error occurs, a display member constituting member, particularly an expensive display member constituting member, can be reused.

Here, the adhesive force in the present specification basically refers to the adhesive force measured according to 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 attached to the adherend. After sticking and pressurizing at 0.5 MPa and 50°C for 20 minutes, it is allowed to stand for 24 hours under conditions of normal pressure, 23°C and 50% RH, and then the measurement is performed at a peel rate of 300 mm/min. In addition, in the case of an active energy ray-curable pressure-sensitive adhesive, it is assumed that it is the adhesive force to the colored pressure-sensitive adhesive layer cured with active energy ray after the adherend is affixed. In addition, in the case of an active energy ray-curable adhesive, the adhesive strength of the adhesive before curing with an active energy ray is preferably 1 to 80 N/25 mm from the viewpoint of adhesiveness and rework property with an adherend, and 2 to 50 N/ It is particularly preferably 25 mm, and more preferably 4 to 30 N/25 mm.

3. Preparation of colored adhesive sheet

As an example of manufacture of the colored adhesive sheet 1, a coating solution of the adhesive composition P is applied to the peeling surface of one release sheet 12a (or 12b), followed by heat treatment to thermally crosslink the adhesive composition P. Then, after forming the coating layer, the peeling surface of the other peeling sheet 12b (or 12a) is laminated on the coating layer. When a curing period is required, a curing period is provided, and when a curing period is unnecessary, the coating layer becomes the colored pressure-sensitive adhesive layer 11 as it is. Thereby, the said colored adhesive sheet 1 is obtained. The conditions for heat treatment and curing are as described above.

As another production example of the colored adhesive sheet 1, the coating solution of the adhesive composition P is applied to the peeling surface of one release sheet 12a, and heat treatment is performed to thermally crosslink the adhesive composition P, and the coating layer Is formed to obtain a release sheet 12a having a coating layer. Further, to the peeling surface of the other peeling sheet 12b, the coating solution of the adhesive composition P is applied, and heat treatment is performed to thermally crosslink the adhesive composition P, forming a coating layer, and a release sheet having a coating layer ( 12b) is obtained. Then, the release sheet 12a having the coating layer and the release sheet 12b having the coating layer were bonded together so that both coating layers were in contact with each other. Here, a plurality of release sheets having a coating layer may be produced, and the coating layers may be bonded by a desired number. When a curing period is required, a curing period is provided, and when a curing period is unnecessary, the laminated coating layer becomes the colored pressure-sensitive adhesive layer 11 as it is. Thereby, the said colored adhesive sheet 1 is obtained. According to this manufacturing example, even when the colored pressure-sensitive adhesive layer 11 is thick, it becomes possible to stably manufacture.

As a method of applying the application 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, or the like can be used.

[Display]

Examples of the type of display (display) according to the present embodiment include, for example, a vehicle instrument panel, a car navigation system, a vehicle-mounted display body for various instruments installed in a console, and a tablet terminal for general users. A display body, a display body such as a commercial tablet terminal or a digital signage, and a display body such as an outdoor digital signage, etc. are mentioned. Such a display body may be required for appearance harmony with peripheral members, luxury, and the like. 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 component 21 (one display body component member) and a second display body component 22 ( Other display member constituent members), and a colored pressure-sensitive adhesive layer 11 in which the first display member 21 and the second display member 22 are bonded to each other.

At least one of the first display member 21 and the second display member 22 may have a level difference at least on the side to be bonded by the colored pressure-sensitive adhesive layer 11. In the present embodiment shown in FIG. 2, the first display member 21 has a level difference such as the printing layer 3 on the surface on the side of the colored pressure-sensitive adhesive layer 11.

The colored pressure-sensitive adhesive layer 11 in the display body 2 is the colored pressure-sensitive adhesive layer 11 of the colored pressure-sensitive adhesive sheet 1 described above.

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

It is preferable that the 1st display body constituent member 21 is a protective panel which consists of a glass plate, a plastic plate, etc. and a laminated body including these. In this case, the printing layer 3 is generally formed on the side of the colored pressure-sensitive adhesive layer 11 in the first display member 21 in a liquid form.

It does not specifically limit as said glass plate, For example, chemically strengthened glass, alkali free glass, quartz glass, soda lime glass, barium-strontium-containing glass, aluminosilicate glass, lead glass, borosilicate glass, barium borosilicate glass, etc. Can be mentioned. The thickness of the glass plate is not particularly limited, but is usually 0.1 to 5 mm, preferably 0.2 to 2 mm.

The plastic plate is not particularly limited, and examples thereof include an acrylic plate and a polycarbonate plate. The thickness of the plastic plate is not particularly limited, but is usually 0.2 to 5 mm, preferably 0.4 to 3 mm.

Further, various functional layers (transparent conductive film, metal layer, silica layer, hard coat layer, anti-glare layer, etc.) may be provided on one or both surfaces of the glass plate or plastic plate, or an optical member may be laminated. Further, the transparent conductive film and the metal layer may be patterned.

The second display member 22 is an optical member to be affixed to the first display member 21, a display module (e.g., a liquid crystal (LCD) module, a light emitting diode (LED) module, An organic electroluminescence (organic EL) module, etc.), an optical member as a part of a display module, or a laminate including a display module is preferable.

As the optical member, for example, a scattering prevention 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, a diffusion film, A semi-transmissive and reflective film, a transparent conductive film, etc. are mentioned. Examples of the scattering prevention film include a hard coat film formed by forming a hard coat layer on one side of a base film.

The material constituting the printing layer 3 is not particularly limited, and a known material for printing is used. The thickness of the printing 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. When the lower limit is more than the above, it is possible to sufficiently secure concealability such as making the electrical wiring invisible from the viewer side. In addition, the upper limit value is preferably 50 μm or less, more preferably 35 μm or less, particularly preferably 25 μm or less, and still more preferably 20 μm or less. When the upper limit is below the above, it is possible to prevent deterioration of the level difference followability of the colored pressure-sensitive adhesive layer 11 with respect to the printing layer 3.

In order to manufacture the display body 2, as an example, one peeling sheet 12a of the colored pressure-sensitive adhesive sheet 1 is peeled off, and the exposed colored pressure-sensitive adhesive layer 11 of the colored pressure-sensitive adhesive sheet 1 is prepared as a first It adheres to the surface of the display body constituent member 21 on the side where the print layer 3 is present.

Then, the other release sheet 12b is peeled from the colored pressure-sensitive adhesive layer 11 of the colored pressure-sensitive adhesive sheet 1, and the exposed colored pressure-sensitive adhesive layer 11 and the second display of the colored pressure-sensitive adhesive sheet 1 The sieve member 22 is bonded together. In addition, as another example, the order of bonding of the first display member 21 and the second display member 22 may be changed.

When the colored pressure-sensitive adhesive layer 11 is curable with active energy rays, the first display member 21 and the second display member 22 are attached through the colored pressure-sensitive adhesive layer 11 as described above. After combining, the colored pressure-sensitive adhesive layer 11 is irradiated with active energy rays. Thereby, the energy ray-curable component (C) in the colored pressure-sensitive adhesive layer 11 is polymerized, and the colored pressure-sensitive adhesive layer 11 is cured. Irradiation of energy rays to the colored pressure-sensitive adhesive layer 11 is usually performed over either the first display member 21 or the second display member 22, and preferably, as a protective panel. It is carried out over the first display member constituting member 21.

The active energy ray refers to an electromagnetic wave or a charged particle ray having both energy, and specifically, an ultraviolet ray, an electron beam, and the like. Among the active energy rays, ultraviolet rays that are easy to handle are particularly preferred.

The irradiation of ultraviolet rays can be performed by a high-pressure mercury lamp, a fusion H lamp, a xenon lamp, etc., and the irradiation amount of ultraviolet rays is preferably about 50 to 1000 mW/cm 2, and preferably about 100 to 500 mW/cm 2 Do. In addition, the amount of light is preferably 50 to 10000 mJ/cm 2, more preferably 200 to 7000 mJ/cm 2, and particularly preferably 500 to 3000 mJ/cm 2. On the other hand, the electron beam irradiation 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 krad.

Here, as shown in FIG. 3, it is preferable that the display body 2 according to the present embodiment has a frame member 4 at the periphery of the display body 2. It is preferable that this frame member 4 is black. In addition, as the color taste of the frame material 4, the preferable ranges of the brightness L*, the chromaticity a*, and the chromaticity b* defined by the CIE1976 L*a*b* color system are as described above as the color taste of the peripheral member. The frame material 4 has such a color taste and is easily recognized as a visually luxurious frame material by the human eye. In addition, in the colored pressure-sensitive adhesive layer 11 in the present embodiment, the frame member 4 has the color taste, and the sense of unity with the frame member 4 increases, and the appearance coordination is improved.

In the display body 2, due to the physical properties of the colored pressure-sensitive adhesive layer 11 described above, the appearance of whiteness when turned off is suppressed, and the designability is improved. As a result, for example, a sense of unity with the black frame member 4 is imparted, and an excellent appearance coordination is obtained. In addition, the display body 2 secures visibility as a display body.

In addition, in the display body 2, when the colored pressure-sensitive adhesive layer 11 is formed of the adhesive composition P, the colored pressure-sensitive adhesive layer 11 has excellent step-level followability under high-temperature and high-humidity conditions, so that the display body 2, For example, even when placed under a high temperature and high humidity condition (for example, 85°C, 85%RH), it is suppressed that lifting, peeling, etc. occur in the vicinity of the step.

The level difference following property can be determined by using the level difference tracking rate (%) as an index. As for the colored pressure-sensitive adhesive layer 11, the step difference following rate (%) represented by the following formula is preferably 10% or more, more preferably 20% or more, particularly preferably 40% or more, and further 60% or more as the lower limit. It is desirable. In addition, although it does not specifically limit as an upper limit of the step difference tracking rate, it is usually preferably 80% or less, and particularly preferably 70% or less.

Step tracking rate (%) = ｛(After a predetermined durability test, the height of the step in which the buried state is maintained (μm)) / thickness of the colored adhesive layer)｝ × 100

In addition, the test method of the level difference following rate is as shown in the test example mentioned later.

The embodiments described above are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents falling within the technical scope of the present invention.

For example, either or both of the release sheets 12a and 12b in the colored pressure-sensitive adhesive sheet 1 may be omitted, and a desired optical member may be laminated in place of the release sheets 12a and/or 12b. good. Moreover, the 1st display body structural member 21 may not have a level difference. Further, not only the first display member 21 but also the second display member 22 may have a level difference on the side of the colored pressure-sensitive adhesive layer 11.

Example

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

[Example 1]

1. Preparation of (meth)acrylic acid ester polymer

70 parts by mass of 2-ethylhexyl acrylate, 15 parts by mass of methyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate were copolymerized by a solution polymerization method 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 800,000.

2. Preparation of adhesive composition

100 parts by mass of the (meth)acrylic acid ester polymer (A) obtained in the above step 1 (in terms of solid content; the same as below) and trimethylolpropane-modified tolylene diisocyanate (manufactured by TOYOCHEM CO., LTD., as a crosslinking agent (B)) Product name "BHS8515") 0.2 parts by mass, 0.4 parts by mass of carbon black black pigment (C1) as a coloring agent (C), and 0.2 parts by mass of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent are mixed, and sufficiently stirred Then, by diluting with methyl ethyl ketone, a coating solution of the adhesive composition was obtained.

Here, each formulation (solid content conversion value) of the adhesive composition in the case where the (meth)acrylic acid ester polymer (A) is 100 parts by mass (in terms of solid content) is shown in Table 1. In addition, details, such as the abbreviation shown in Table 1, are as follows.

[(Meth)acrylic acid ester polymer (A)]

2EHA: 2-ethylhexyl acrylate

MMA: methyl methacrylate

HEA: 2-hydroxyethyl acrylate

IBXA: Isobornyl acrylate

ACMO: N-acryloylmorpholine

BA: n-butyl acrylate

AA：acrylic acid

[Coloring agent (C)]

C1 to C6: Carbon black-based black pigment having the physical properties shown in Table 2

3. Preparation of colored adhesive sheet

The coating solution of the adhesive composition obtained in the above step 2 was applied to the peeling-treated surface of a heavy-release type release sheet (manufactured by LINTEC Corporation, product name ``SP-PET752150'') in which one side of the polyethylene terephthalate film was peeled off with a silicone-based release agent. After coating with, heat treatment was performed at 90° C. for 1 minute to form a coating layer (thickness: 50 μm). In the same way, the peeling-treated side of a light-release type release sheet (manufactured by LINTEC Corporation, product name ``SP-PET381130'') in which one side of a polyethylene terephthalate film was peeled off with a silicone-based release agent with the coating solution of the adhesive composition obtained in step 2 above. Then, after application|coating with a knife coater, it heat-processed at 90 degreeC for 1 minute, and the coating layer (thickness: 50 micrometers) was formed.

Then, the heavy-release type release sheet having the coating layer obtained above and the light-release type release sheet having the coating layer obtained above are bonded so that both coating layers are in contact with each other, and under conditions of 23°C and 50%RH for 7 days. Curing was carried out to prepare a colored pressure-sensitive adhesive sheet composed of a medium-release type release sheet/colored pressure-sensitive adhesive layer (thickness: 100 μm)/a light-release type release sheet.

In addition, the thickness of the colored pressure-sensitive adhesive layer is a value measured using a static pressure thickness measuring instrument (manufactured by TECLOCK, product name "PG-02") in accordance with JIS K7130.

(Examples 2 to 8, Comparative Examples 1 to 2)

The type and ratio of each monomer constituting the (meth)acrylic acid ester polymer (A), the weight average molecular weight (Mw) of the (meth)acrylic acid ester polymer (A), the type and amount of the colorant (C), and the amount of the silane coupling agent. , And the thickness of the colored pressure-sensitive adhesive layer were changed as shown in Table 1, and a colored pressure-sensitive adhesive sheet was produced in the same manner as in Example 1. However, in Example 5, ε-caprolactone-modified tris-(2-acryloxyethyl) isocyanurate (manufactured by Shin-Nakamura Chemical Co., Ltd.) as an active energy ray-curable component (D), the product name "NK" Ester 　A-9300-1 CL") 5.0 parts by mass, and 0.5 parts by mass of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide as a photopolymerization initiator (E) were further added to obtain an active energy ray-curable adhesive. Got it. In Comparative Example 1, the coloring agent (C) is not used, but for convenience, the phrases of the colored adhesive layer and the colored adhesive sheet are used.

In addition, about the colored adhesive sheet of Examples 3-8 and Comparative Examples 1-2, it manufactured as follows. A coating solution of the adhesive composition prepared in the same manner as in Example 1 was applied to the peeling-treated side of a heavy-release type release sheet (manufactured by LINTEC Corporation, product name ``SP-PET752150'') in which one side of a polyethylene terephthalate film was peeled off with a silicone-based release agent, After coating with a knife coater, heat treatment was performed at 90° C. for 1 minute to form a coating layer. Peel treatment of a light-release type release sheet (manufactured by LINTEC Corporation, product name ``SP-PET381130'') in which the side of the coated layer side and one side of the polyethylene terephthalate film in the medium-release type release sheet having the obtained coating layer are peeled with a silicone-based release agent The sides were bonded together and cured for 7 days under conditions of 23°C and 50%RH to prepare a colored adhesive sheet having a configuration of a heavy-release type release sheet/colored adhesive layer/light-release type release sheet.

The above-described weight average molecular weight (Mw) is a weight average molecular weight in terms of polystyrene measured under the following conditions (GPC measurement) using gel permeation chromatography (GPC).

<Measurement conditions>

GPC measuring device: manufactured by TOSOH CORPORATION, HLC-8020

GPC column (pass through in the following order): manufactured by TOSOH CORPORATION

TSK guard column HXL-H

TSK gel GMHXL(×2)

TSK gel G2000HXL

-Measurement solvent: Tetrahydrofuran

·Measurement temperature: 40℃

[Test Example 1] (Measurement of the haze value of the colorant diluted solution)

A haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000", optical path length), in accordance with JIS K7136:2000, for a liquid obtained by diluting C1 to C6 colorants 10,000 times with ethyl acetate. 10 mm) was used to measure the haze value (%). From the measured values, the difference between the haze value at the wavelength of 780 nm and the haze value at the wavelength of 380 nm, the average haze that is the average value of the haze value at the wavelength of 780 nm and the haze value at the wavelength of 380 nm, and the wavelength range 380 nm to 780 nm The standard deviation of the haze value at each wavelength of 5 nm pitch was calculated. Table 2 shows each result.

[Test Example 2] (Measurement of gel fraction)

The colored pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples were cut to a size of 80 mm×80 mm, and the colored pressure-sensitive adhesive layer was wrapped in a polyester mesh (mesh size 200), and the mass was weighed with a precision balance, and the mesh The mass of only the adhesive was calculated by subtracting the mass of the individual. 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. After that, the pressure-sensitive adhesive was taken out, air-dried for 24 hours in an environment at 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 mesh alone was subtracted to calculate the mass of the adhesive only. The mass at this time is M2. The gel fraction (%) is represented by (M2/M1) x 100. Table 3 shows the results.

In addition, for the colored adhesive sheet of Example 5, a plastic plate (Mitsubishi Gas Chemical Co., Ltd.,) in which a polymethyl methacrylate resin (PMMA) layer was laminated on a polycarbonate resin (PC) plate on a light-release type release sheet. Inc., product name "Iupilon · Sheet MR58U", thickness: 0.7 mm, containing an ultraviolet absorber) was laminated, and the colored pressure-sensitive adhesive layer was cured by irradiating an active energy ray over the plastic plate under the following conditions. Also about the adhesive of the colored adhesive layer after curing, the gel fraction (after UV) was derived in the same manner as described above.

<Active energy ray irradiation conditions>

·Use of high pressure mercury lamp

·Illuminance 200 mW/㎠, Light intensity 2000 mJ/㎠

·UV illuminance/photometer uses “UVPF-A1” manufactured by iGrafx

[Test Example 3] (Measurement of storage modulus)

The release sheet was removed from the colored pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples, and a plurality of colored pressure-sensitive adhesive layers were laminated to have a thickness of 3 mm. In the laminate of the obtained colored pressure-sensitive adhesive layer, a cylindrical body (3 mm in height) having a diameter of 8 mm was punched out, and this was used as a sample.

With respect to the sample, in accordance with JIS K7244-6, the storage modulus (MPa) was measured under the following conditions according to the torsional shear method using a viscoelasticity measuring device (manufactured by Physica, product name "MCR300"). Table 3 shows the results.

Measurement frequency: 1Hz

Measurement temperature: 23℃

In addition, for the colored pressure-sensitive adhesive sheet of Example 5, in the same manner as in Test Example 2, the colored pressure-sensitive adhesive layer was cured by irradiating an active energy ray, and the storage elastic modulus (after UV) was determined as described above for the colored pressure-sensitive adhesive layer after curing. Measured.

[Test Example 4] (Measurement of haze value)

About the colored pressure-sensitive adhesive layer of the colored pressure-sensitive adhesive sheet obtained in Examples and Comparative Examples, according to JIS K7136:2000, a haze value was used using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000"). (%) was measured. Table 3 shows the obtained total light haze value (%). In addition, from the measured values, the average haze value, which is the average value of the haze value at the wavelength 780 nm and the haze value at the wavelength 380 nm, the difference between the haze value at the wavelength 780 nm and the haze value at the wavelength 380 nm, the wavelength range 380 nm to 780 The standard deviation of the haze value was calculated at each wavelength of a 5 nm pitch of nm.

In addition, for the colored pressure-sensitive adhesive sheet of Example 5, in the same manner as in Test Example 2, the colored pressure-sensitive adhesive layer was cured by irradiating an active energy ray, and for the colored pressure-sensitive adhesive layer after curing, as described above, the total light haze value (after UV ) Was measured. And, from the measured value, the average haze (after UV), which is the average value of the haze value at the wavelength 780 nm and the haze value at the wavelength 380 nm, and the difference between the haze value at the wavelength 780 nm and the haze value at the wavelength 380 nm (after UV ), the standard deviation of the haze value (after UV) was calculated at each wavelength of a 5 nm pitch in a wavelength range of 380 nm to 780 nm. Table 3 shows the results of each.

[Test Example 5] (Measurement of total light transmittance)

The colored pressure-sensitive adhesive layer of the colored pressure-sensitive adhesive sheet obtained in Examples and Comparative Examples was bonded to glass, and this was used as a sample for measurement. After background measurement is performed with glass, the total light transmittance of the sample for measurement is in accordance with JIS K7361-1:1997, and a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000") is used. (%) was measured. In addition, for the colored pressure-sensitive adhesive sheet of Example 5, in the same manner as in Test Example 2, the colored pressure-sensitive adhesive layer was cured by irradiating active energy rays, and for the colored pressure-sensitive adhesive layer after curing, the total light transmittance (after UV) was determined as described above. Measured. Table 3 shows the results.

[Test Example 6] (Measurement of L*a*b*)

For the colored pressure-sensitive adhesive layer of the colored pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples, using a simultaneous photometric spectroscopic colorimeter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SQ2000"), CIE 1976 L*a*b* The brightness L*, the chromaticity a*, and the chromaticity b* defined by the colorimeter were measured. Further, for the colored pressure-sensitive adhesive sheet of Example 5, in the same manner as in Test Example 2, the colored pressure-sensitive adhesive layer was cured by irradiating an active energy ray, and for the colored pressure-sensitive adhesive layer after curing, the brightness L* (after UV) was carried out as described above. , Chromaticity a* (after UV) and chromaticity b* (after UV) were measured. Table 3 shows the results.

[Test Example 7] (Measurement of adhesive force)

The light-release type release sheet was peeled off from the colored pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples, and the exposed colored pressure-sensitive adhesive layer was formed of a polyethylene terephthalate (PET) film (manufactured by TOYOBO CO., LTD.) having an easily-adhesive layer. , The product name "PET　A4300", thickness: 100 μm) was bonded to the easily-adhesive layer to obtain a release sheet/colored adhesive layer/PET film laminate. The obtained laminate was cut into 25 mm width and 100 mm length, and this was used as a sample.

In an environment of 23° C. and 50% RH, the heavy peeling type release sheet was peeled from the sample, and the exposed colored pressure-sensitive adhesive layer was affixed to soda lime glass (manufactured by Nippon Sheet Glass Company, Ltd.), and then Kurihara Seisakusho K.K. It pressurized for 20 minutes at 0.5 MPa and 50 degreeC with the 1st autoclave. Thereafter, after leaving to stand for 24 hours under the conditions of 23°C and 50%RH, using a tensile tester (manufactured by ORIENTEC Co., Ltd., product name "Tensiron"), a peel rate of 300 mm/min and a peel angle of 180 degrees The adhesive force (N/25 mm) was measured at. Conditions other than those described here were measured according to JIS Z0237:2009. Table 3 shows the results.

Further, for the colored pressure-sensitive adhesive sheet of Example 5, in the same manner as described above, the colored pressure-sensitive adhesive layer was affixed to soda lime glass, subjected to autoclave treatment, and then allowed to stand under conditions of 23°C and 50% RH for 24 hours, and then Test Example 2 In the same manner as in the same manner, active energy rays were irradiated to cure the colored pressure-sensitive adhesive layer. Also about the colored pressure-sensitive adhesive layer after curing, the adhesive strength (after UV) was measured in the same manner as described above.

[Test Example 8] (Measurement of step tracking rate)

On the surface of a glass plate (manufactured by NSG Precision, product name ``Corning Glass EAGLE XG'', 90 mm long x 50 mm wide x 0.5 mm thick, UV curable ink (manufactured by Teikoku Printing Inks Mfg. Co., Ltd., product name ``POS-'') 911 Ink") was screen-printed in a liquid form (Appearance: 90 mm long x 50 mm wide, 5 mm wide.) Then, ultraviolet rays were irradiated (80 W/cm 2, 2 metal halide lamps, lamp height 15 cm, Belt speed 10 to 15 m/min), the printed UV curable ink is cured, and the step by printing (step height: 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 50 μm, 60 μm, and 70 μm) A glass plate having a step having a was produced.

The light-release type release sheet was removed from the colored pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples, and the exposed colored pressure-sensitive adhesive layer was a polyethylene terephthalate film having an easily-adhesive layer (TOYOBO CO., LTD., product name "PET　A4300", thickness: 100 μm) of the adhesive layer. Then, the heavy peeling type release sheet was removed, and the colored pressure-sensitive adhesive layer was exposed. Then, using a laminator (manufactured by Fuji Plastics, product name "LPD3214"), the laminate was laminated on a glass plate having each step so that the colored pressure-sensitive adhesive layer covers the liquid-linked printed entire surface, and this was used as a sample for evaluation.

The obtained sample for evaluation was autoclaved for 30 minutes under the conditions of 50°C and 0.5 MPa, and then left at normal pressure, 23°C and 50% RH for 24 hours. Then, it was stored for 72 hours under a high temperature and high humidity condition of 85°C and 85%RH (durability test), and then, the step followability was evaluated. The level difference followability is judged as whether or not the printing level is completely embedded by the colored pressure-sensitive adhesive layer, and when bubbles, lifting, peeling, etc. are observed at the interface between the printed level difference and the colored pressure-sensitive adhesive layer, it is judged that the printing level cannot be followed. do. Here, the step difference followability was evaluated as a step difference following rate (%) expressed by the following equation. Table 3 shows the results. Step tracking rate (%) = ｛(After the endurance test, the height of the step in which the buried state is maintained (μm)) / thickness of the colored adhesive layer)｝×100

In addition, for the colored pressure-sensitive adhesive sheet of Example 5, a product having a colored pressure-sensitive adhesive layer thickness of 25 μm was prepared, and the sample for evaluation obtained in the same manner as above was subjected to an autoclave treatment, and then under conditions of 23° C. and 50% RH for 24 hours. After leaving to stand, it carried out similarly to Test Example 2, and irradiated with active energy rays, and the colored adhesive layer was hardened. About the colored adhesive layer after hardening, it carried out similarly to the above, and measured the step difference following rate (after UV).

[Test Example 9] (Evaluation of design properties)

The colored pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples were cut into a length of 70 mm x a width of 70 mm, and the colored pressure-sensitive adhesive layers of the colored pressure-sensitive adhesive sheets were formed of two soda lime glass (manufactured by Nippon Sheet Glass Company, Ltd., type 70). It was bonded so as to be sandwiched between mm x 70 mm wide x 1.1 mm thick, and this was taken as a sample In addition, about the colored adhesive sheet of Example 5, in the same manner as in Test Example 2, active energy rays were irradiated to cure the colored adhesive layer, This was taken as a sample.

The obtained sample was installed just before the display in the light-off state (manufactured by Fujitsu, product name "LITEBOOKA574/H", size 15.6 inches, resolution 1366×768). At this time, the sample was installed so that the peripheral portion of the sample and the frame member of the display were adjacent. Then, under a three-wavelength fluorescent lamp (distance from the fluorescent lamp: 200 cm), the color taste (looks black or white) of the sample was visually judged, and the designability regarding the color taste of the screen was evaluated according to the following criteria. Table 3 shows the results.

◎: There are dark black areas even under the reflection of fluorescent lamps.

○: If there is no reflection of fluorescent lamp, there is a dark black part.

X: The whole looks white.

Further, the appearance of the boundary between the sample portion and the frame material of the display was visually judged, and the designability regarding seamlessness was evaluated according to the following criteria. Table 3 shows the results.

◎: The boundary cannot be admitted.

○: The boundaries are slightly admitted, but not conspicuous.

×: Borders can be clearly recognized.

In addition, the color taste (CIE1976 L*a*b* colorimeter) of the frame material of the display was measured using a spectrophotometer (manufactured by BYK, product name "SPECTRO GUIDE"), L*: 19.7, a*: -0.3, b*: -1.5.

[Test Example 10] (evaluation of visibility)

The sample produced in the same manner as in Test Example 9 was installed immediately before the illuminated display (manufactured by Fujitsu, product name "LITEBOOKA574/H", size 15.6 inches, resolution 1366×768). At this time, the ARIB multi-format color bar was displayed on the display. Then, under a three-wavelength fluorescent lamp (distance from the fluorescent lamp: 200 cm), visually judge the appearance of the display beyond the sample from the front and inclination (angle of 45°) with respect to the sample, and make visibility according to the following criteria. (Wide-angle visibility) was evaluated. Table 3 shows the results.

◎: The appearance from the front and the appearance from the slope do not change.

○: Compared with the appearance from the front, the appearance from the slope becomes darker, but the color tone does not change.

×: The color tone changes between the appearance from the front and the appearance from the slope.

In addition, in any example, the screen was bright when viewed from the front, and thus the visibility of the image due to the brightness of the screen was good.

As can be seen from Table 3, what used the colored pressure-sensitive adhesive sheet obtained in Examples was excellent in designability (especially designability regarding color taste of the screen) and visibility (in particular, wide-angle visibility and visibility due to brightness of the screen). In addition, the colored pressure-sensitive adhesive sheet obtained in Examples was also excellent in step followability.

The colored pressure-sensitive adhesive sheet of the present invention is suitably used, for example, for bonding display member constituting members in a display body having a black frame material, particularly, bonding a protective panel having a level difference and a desired display member constituting member. I can.

1: colored adhesive sheet
11: colored adhesive layer
12a, 12b: peeling sheet
2: display
21: 1st display body component member
22: second display member constituting member
3: printing layer
4: frame materials

Claims (13)

A colored pressure-sensitive adhesive sheet provided with a colored pressure-sensitive adhesive layer made of a pressure-sensitive adhesive containing a colorant for bonding one display member constituting member and another display member constituting member,
The colored pressure-sensitive adhesive sheet, wherein the average haze of the colored pressure-sensitive adhesive layer, which is an average value of a haze value at a wavelength of 780 nm and a haze value at a wavelength of 380 nm, is 1% or more and 60% or less. The method of claim 1,
The colored pressure-sensitive adhesive sheet, wherein a value of a difference between a haze value at a wavelength of 780 nm and a haze value at a wavelength of 380 nm of the colored pressure-sensitive adhesive layer is 15 points or less. The method of claim 1,
The colored pressure-sensitive adhesive sheet, wherein the standard deviation of the haze value of the colored pressure-sensitive adhesive layer is 5 or less at each wavelength of a 5 nm pitch in a wavelength range of 380 nm to 780 nm. The method of claim 1,
The total light transmittance of the colored pressure-sensitive adhesive layer is 10% or more and less than 95%,
The colored pressure-sensitive adhesive sheet, wherein the chromaticity a* and the chromaticity b* defined by the CIE1976 L*a*b* color system of the colored pressure-sensitive adhesive layer are -7 to 7, respectively. The method of claim 1,
The colored adhesive sheet, wherein the average haze, which is an average value of the haze value at a wavelength of 780 nm and a haze value at a wavelength of 380 nm, of the liquid obtained by diluting the colorant 10,000 times with ethyl acetate is 1% or more and 60% or less. The method of claim 1,
The colored adhesive sheet, wherein the difference between the haze value at a wavelength of 780 nm and a haze value at a wavelength of 380 nm of the liquid obtained by diluting the colorant 10,000 times with ethyl acetate is 30 points or less. The method of claim 1,
The colored adhesive sheet, wherein the colorant is a black pigment. The method of claim 1,
The said adhesive is an acrylic adhesive, The colored adhesive sheet characterized by the above-mentioned. The method of claim 1,
The said adhesive is a colored adhesive sheet characterized by crosslinking an adhesive composition containing a (meth)acrylic acid ester polymer (A), a crosslinking agent (B), and a coloring agent (C). The method of claim 1,
Two release sheets, and
The colored pressure-sensitive adhesive layer sandwiched between the release sheet so as to contact the release surface of the two release sheets,
A colored adhesive sheet comprising a. One indicator component member,
Other indicator components, and
A colored pressure-sensitive adhesive layer for bonding the one display body component member and the other display body component member to each other,
As a display body having,
A display body, wherein the colored pressure-sensitive adhesive layer is a colored pressure-sensitive adhesive layer of the colored pressure-sensitive adhesive sheet according to any one of claims 1 to 10. The method of claim 11,
A display body, wherein at least one of the one display body component member and the other display body component member has a level difference on at least a surface of the side to be bonded by the colored pressure-sensitive adhesive layer. The method of claim 11,
A display body, characterized in that it has a black frame material.

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