JP6992930B2 - Adhesive sheet - Google Patents

Description

The present invention relates to a pressure-sensitive adhesive sheet containing an ultraviolet absorber.

It has excellent weather resistance for exterior members such as gate posts and window frames, outdoor signboards such as advertising towers and field signs, vehicles such as motorcycles and automobiles, marking films used for play equipment, and UV-resistant protective films. However, it is required that the performance can be maintained for a long time.

For example, in Patent Document 1, a first layer of an adhesive layer, a second layer of a film layer, and a third layer of a surface protective layer are laminated in this order, and the first layer and the second layer have an ultraviolet absorption wavelength region. A pressure-sensitive adhesive sheet containing an ultraviolet absorber containing different ultraviolet absorbers and having an ultraviolet absorption wavelength region overlapping with both the ultraviolet absorption wavelength regions of the first layer and the second layer is described as the third layer. As described above, Patent Document 1 proposes a method in which each layer contains the above-mentioned ultraviolet absorbers having different ultraviolet absorption wavelength regions in order for the pressure-sensitive adhesive sheet to exhibit high weather resistance.

Further, as the member or the like for the above-mentioned use, for example, there is a plastic product or the like using a polyvinyl chloride sheet as a base material and a decorative sheet provided with a decorative layer, a surface protective layer and the like as needed (for example, Patent Documents). 2).

JP-A-2017-132928 Special Publication No. 58-14321

However, the pressure-sensitive adhesive sheet of Patent Document 1 has obtained only 144 hours of weather resistance in the accelerated weather resistance test, and cannot be said to have sufficiently satisfactory weather resistance. In particular, it is desired that the weather resistance of the adhesive sheet used outdoors is maintained for a longer period of time.

Further, when the decorative sheets of Patent Documents 1 and 2 are attached to a substrate to manufacture a decorative member, there is a problem that the end face of the decorative sheet is peeled off due to insufficient initial adhesion strength, that is, so-called springback occurs. .. Decorative sheets that generate springback are not sufficiently suitable for construction.
On the other hand, when the decorative member having the above-mentioned decorative sheet attached to the substrate is used, the substrate constituting the decorative sheet provided on the outermost surface is deteriorated due to the influence of moisture in the atmosphere, wind and rain, and ultraviolet rays due to sunlight. In addition, there is a problem that the decorative sheet is peeled off from the substrate due to deterioration of the adhesive that adheres the decorative sheet and the substrate.

Therefore, the present invention is excellent in that it has excellent weather resistance for a long period of time, maintains adhesion between layers, has high initial adhesion strength in the construction process, is excellent in construction suitability, and does not cause peeling even after long-term use. An object of the present invention is to provide a pressure-sensitive adhesive sheet that exhibits long-term adhesion and a decorative member having the pressure-sensitive adhesive sheet.

As a result of diligent studies to solve the above problems, the present inventor came up with the following invention and found that the problems can be solved.
That is, the present invention is as follows.

[1] It has an A layer including a surface protective layer containing an ultraviolet absorber 1 and a B layer including an adhesive layer containing an ultraviolet absorber 2.
The _average value of the absorbance A1 of the A layer measured in accordance with JIS K0115: 2004 at a wavelength of 300 nm or more and 360 nm or less is 0.8 or more, and the A layer and measured in accordance with JIS K0115: 2004. The average value of the absorbance A ₂ of the B layer at a wavelength of 300 nm or more and 360 nm or less is 1.2 or more.
The moisture permeability measured in accordance with the moisture permeability test method (cup method) of the moisture-proof packaging material specified in JIS Z0208: 1976 of the adhesive sheet is 0.75 g / m 2.24 h or ^more and 45 g / ^m 2.24 h or less. Is an adhesive sheet.
[2] A decorative member having the pressure-sensitive adhesive sheet and the substrate of the above-mentioned [1] via an adhesive layer so that the film layer of the pressure-sensitive adhesive sheet and the substrate face each other.

According to the present invention, the weather resistance is excellent for a long time, the adhesion between each layer is maintained, the initial adhesion strength in the construction process is high, the construction suitability is excellent, and peeling does not occur even after long-term use. It is possible to provide a pressure-sensitive adhesive sheet that exhibits long-term adhesion and a decorative member having the pressure-sensitive adhesive sheet.

It is sectional drawing which shows one Embodiment of the adhesive sheet of this invention. It is sectional drawing which shows one Embodiment of the decorative member of this invention.

[Adhesive sheet]
Hereinafter, the adhesive sheet of the present invention will be described. In addition, in this specification, the numerical values relating to "greater than or equal to" and "less than or equal to" regarding the description of the numerical range are numerical values that can be arbitrarily combined, and the numerical values of Examples are numerical values that can be used for the upper and lower limits of the numerical range.

The pressure-sensitive adhesive sheet of the present invention has an A layer including a surface protective layer containing an ultraviolet absorber 1 and a B layer including a pressure-sensitive adhesive layer containing an ultraviolet absorber 2.
The _average value of the absorbance A1 of the A layer measured in accordance with JIS K0115: 2004 at a wavelength of 300 nm or more and 360 nm or less is 0.8 or more, and the A layer and measured in accordance with JIS K0115: 2004. The average value of the absorbance A ₂ of the B layer at a wavelength of 300 nm or more and 360 nm or less is 1.2 or more.
The moisture permeability measured in accordance with the moisture permeability test method (cup method) of the moisture-proof packaging material specified in JIS Z0208: 1976 of the adhesive sheet is 0.75 g / m 2.24 h or ^more and 45 g / ^m 2.24 h or less. It is characterized by being.
Further, the pressure-sensitive adhesive sheet of the present invention may be a sheet in which the layer A further includes a film layer containing an ultraviolet absorber 3, and has a surface protective layer, a film layer, and a pressure-sensitive adhesive layer in this order.

Hereinafter, "the average value of the absorbance A ₁ in the wavelength range of 300 nm or more to 360 nm of the layer A measured according to JIS K0115: 2004" was measured according to "absorbance A ₁ " and "JIS K0115: 2004". , The average value of the absorbance A ₂ at a wavelength of 300 nm or more and 360 nm or less of the layers A and B "may be referred to as" absorbance A ₂ ". Further, the "A layer" means a layer including both a surface protection layer and a film layer, and the "B layer" means a layer including an adhesive layer.
Further, "absorbance A ₂ at a wavelength of 300 nm or more and 360 nm or less of the A layer and B layer" is an average value of absorbance at a wavelength of 300 nm or more and 360 nm or less measured from the A layer side in a state where the A layer and the B layer are laminated. means.

FIG. 1 is a cross-sectional view showing an embodiment of the pressure-sensitive adhesive sheet 100 of the present invention.
The pressure-sensitive adhesive sheet 100 of FIG. 1 has a surface protective layer 10, a film layer 30, and a pressure-sensitive adhesive layer 20 in this order.

<Asorbance>
The pressure-sensitive adhesive sheet of the present invention has an absorbance A ₁ of 0.8 or more and an absorbance A ₂ of 1.2 or more. A large absorbance A ₁ means that there is little light having a wavelength of 300 nm or more and 360 nm or less that reaches the surface protective layer itself, which is the A layer, or the surface protective layer and the film layer, and a large absorbance A ₂ means that there is little light. It means that there is little light having a wavelength of 300 nm or more and 360 nm or less that reaches the adhesive layer which is the B layer.
Although the degree of various UV absorbers varies depending on the material, all of them are lost over time due to bleeding out from the layer to the outside, and the concentration thereof decreases. Therefore, even if the deterioration of each layer below the surface protective layer due to ultraviolet rays can be suppressed in the short term, the suppression of deterioration due to ultraviolet rays cannot be sustained for a long period of time. Generally, weather resistance is the time it takes for each layer below the surface protective layer (that is, the entire adhesive sheet) to reach a predetermined degree of deterioration due to UV rays when exposed to sunlight including UV rays. Be evaluated. Therefore, there is a limit to the improvement of weather resistance in the design in which _only the absorbance A1 of the layer A including the surface protective layer is increased. Further, by increasing the amount of the ultraviolet absorber in the surface protective layer in advance, even if a certain amount of the ultraviolet absorber bleeds out from the surface protective layer, the predetermined weather resistance (time until deterioration is reached). ) Can be maintained. However, in that case, there are problems such as deterioration of physical properties such as scratch resistance and stain resistance of the surface protective layer due to excessive addition of the ultraviolet absorber, and deterioration of the appearance such as white turbidity of the surface due to the bleed-out ultraviolet absorber. , Such a design was also practically difficult to adopt.
Furthermore, even if two types of average absorbance values (absorbance A ₁ and absorbance A ₂ ) are specified, if the absorbance A ₁ is less than 0.8 or the absorbance A ₂ is less than 1.2, With respect to the pressure-sensitive adhesive sheet obtained by laminating each layer including the pressure-sensitive adhesive layer, deterioration over time due to ultraviolet rays cannot be sufficiently suppressed, and the weather resistance deteriorates.

The absorbance A ₁ and the absorbance A ₂ defined in the present invention are both average values of the absorbances of light having a wavelength of 300 nm or more and 360 nm or less, and are also characterized in that the wavelength of ultraviolet rays to be absorbed is specified in the present invention. ..
The resin used for the pressure-sensitive adhesive layer has an absorption wavelength, and most of them have an absorption wavelength of about 300 nm or more and 360 nm or less. It is considered that photons of these wavelengths contribute to the deterioration of the resin contained in the pressure-sensitive adhesive layer.
In the present invention, attention is paid to two types of absorbances related to light having a wavelength of 300 nm or more and 360 nm or less, which are common to most of the resins contained in the pressure-sensitive adhesive layer, and absorbance A ₁ and absorbance A ₂ are used as the average values of the two types of absorbances. By setting the range to a specific range, photodegradation of the pressure-sensitive adhesive layer can be suppressed. That is, since the pressure-sensitive adhesive layer is protected by setting the absorbance A ₁ and the absorbance A ₂ in a specific range, the adhesiveness between the pressure-sensitive adhesive layer and the substrate to which the pressure-sensitive adhesive sheet is attached, and the pressure-sensitive adhesive layer and the film layer Adhesion can be maintained. Therefore, it is possible to suppress deterioration of the pressure-sensitive adhesive sheet due to ultraviolet rays over time, and it is possible to impart excellent weather resistance to the pressure-sensitive adhesive sheet for a long period of time.

The absorbance A ₁ is preferably 1.0 or more, more preferably 1.1 or more, and even more preferably 1.2 or more. In addition, increasing the absorbance A ₁ increases the content of the ultraviolet absorber in the A layer, increases the thickness of the A layer, and increases the ultraviolet absorbers 1 and 3 contained in the A layer, which will be described later. It can be achieved by making adjustments such as making a suitable selection.
The absorbance A ₁ is preferably 5.0 or less, more preferably 4.0 or less, and even more preferably 3.0 or less. When the absorbance A ₁ is 5.0 or less, the bleed-out of the ultraviolet absorber in the A layer can be further suppressed, and the scratch resistance of the surface protective layer tends to be improved. Further, since the increase in the film thickness of the surface protective layer can be suppressed, the processability of the pressure-sensitive adhesive sheet can be improved.

The absorbance A ₂ is preferably 1.3 or more, more preferably 1.4 or more, and even more preferably 1.5 or more.
The upper limit of the absorbance A ₂ is not particularly limited, but in consideration of bleed-out, it is preferably 7.0 or less, more preferably 6.5 or less, and further preferably 6.0 or less.
In addition, increasing the absorbance A ₂ can be achieved by selecting the content of the ultraviolet absorber, the thickness of each layer, the selection of the ultraviolet absorber 2, and further the selection of the ultraviolet absorbers 1 and 3, as in the case of the above-mentioned absorbance A ₁ . ..

For the absorbance _A2 of the A layer and the B layer laminate, the absorbance of the laminate having the A layer formed on the B layer at a wavelength of 300 nm or more and 360 nm or less is measured in accordance with JIS K0115: 2004, and the average value is calculated. Obtained by doing.
Further, the absorbance A ₁ of the layer A is obtained by obtaining the average value absorbance A ₀ of the absorbance of the layer B at a wavelength of 300 nm or more and 360 nm or less in accordance with JIS K0115: 2004, and subtracting the absorbance A ₀ from the absorbance A ₂ . (Absorptance A ₁ = Absorbance A ₂ -Asorbance A ₀ ).
In the measurement of the absorbance of each layer (single layer or laminate) at a wavelength of 300 nm or more and 360 nm or less, when a measurement sample for the A layer and the A layer and the B layer laminate is obtained, the absorbance of these layers is measured. By performing the measurement, the absorbance A ₁ and the absorbance A ₂ can be directly obtained, respectively.
If the layer A and the layer B can be separated from the laminated body of the pressure-sensitive adhesive sheet without changing the ultraviolet absorption characteristics of each layer, the absorbance of the pressure-sensitive adhesive sheet and the layer B separated from the pressure-sensitive adhesive sheet should be measured. Then, the absorbance A ₁ and the absorbance A ₂ can be directly obtained, respectively.

Further, in order to more effectively suppress the photodegradation of the resin contained in the pressure-sensitive adhesive layer, the absorbance of the layer A is 0.8 or more at the individual maximum absorption wavelengths of the resin used in the pressure-sensitive adhesive layer, and A. It is preferable that the absorbance of the layer and the B layer is 1.2 or more.
That is, the absorbance of the A layer measured in accordance with JIS K0115: 2004 at a wavelength of 300 nm or more and 360 nm or less and at the maximum absorption wavelength of the resin used for the pressure-sensitive adhesive layer is 0.8 or more, and the A layer is A layer. And a pressure-sensitive adhesive sheet having an absorbance of the B layer of 1.2 or more is preferable.

Specifically, when the resin used for the pressure-sensitive adhesive layer is an acrylic resin, the absorbance of the A layer is 0.8 or more at the maximum absorption wavelength of 315 nm of the acrylic resin, and the absorbance of the A layer and the B layer. It is preferable that the pressure-sensitive adhesive sheet has a value of 1.2 or more.
The maximum absorption wavelength of the resin used for the pressure-sensitive adhesive layer at a wavelength of 300 nm or more and 360 nm or less is, for example, a maximum absorption wavelength of 341 nm in the case of a polyurethane-based resin, and a polystyrene-based resin and a rubber-based resin containing a styrene component. Has a maximum absorption wavelength of 318 nm, and in the case of a polyester resin, has a maximum absorption wavelength of 325 nm. At the maximum absorption wavelength of each resin used for the pressure-sensitive adhesive layer, the absorbance of the A layer is 0.8 or more, and the absorbance of the A layer and the B layer is 1.2 or more, which is sufficient for the effect of the present invention. It is preferable because it plays. Although some resins have an absorption region at a shorter wavelength, they are strongly absorbed by the ozone layer of the earth and the Hartley band (200 nm or more and 300 nm or less), and the amount that reaches the adhesive sheet on or near the ground is small. Therefore, there is no particular problem in itself that the resin of the pressure-sensitive adhesive layer in the present invention has a maximum absorption wavelength in a wavelength band of less than 300 nm. However, even a resin having a small absorption amount in the band having a wavelength of 300 nm or more and 360 nm or less may be adopted as the resin for the pressure-sensitive adhesive layer in the present invention as long as the effect of the present invention is not impaired.
In the maximum absorption wavelength of each resin used for the pressure-sensitive adhesive layer, the more preferable range of the absorbance of the _A layer is the same as the preferred embodiment of the above-mentioned absorbance A1, and the more preferable range of the absorbance of the A layer and the B layer is. This is the same as the preferred embodiment of the absorbance A ₂ described above.

<Humidity permeability>
The adhesive sheet of the present invention has a moisture permeability of 0.75 g / m 2.24 h or more and 45 g / m ² measured in accordance with the moisture permeability test method (cup method) of the moisture ^- proof packaging material specified in JIS Z0208: 1976. -It is characterized by being 24 hours or less.
The pressure-sensitive adhesive sheet of the present invention exhibits high initial adhesion strength in the process of constructing the pressure-sensitive adhesive sheet by setting the moisture permeability within the above-mentioned specific range. For this reason, it is possible to suppress the occurrence of so-called springback in which the end face of the adhesive sheet is peeled off due to insufficient initial adhesion strength during construction, so that construction efficiency can be improved. On the other hand, when the pressure-sensitive adhesive sheet and the substrate are used as a decorative member via an adhesive layer, deterioration of the adhesive layer between the pressure-sensitive adhesive sheet and the substrate can be suppressed. Therefore, peeling due to deterioration of the adhesive layer is suppressed, and peeling does not occur even after long-term use, and excellent long-term adhesion is exhibited. That is, by setting the moisture permeability of the adhesive sheet of the present invention within a specific range, it is possible to achieve both excellent construction suitability due to the high initial adhesion strength in the construction process and long-term adhesion that does not cause peeling even after long-term use. Will be.

The pressure-sensitive adhesive sheet of the present invention has a moisture permeability of 0.75 g / m 2.24 h or ^more and 45 g / ^m 2.24 h or less. When the moisture permeability is less than 0.75 g / ^m 2.24 hours, when the adhesive is attached to the substrate via the adhesive layer to form a decorative member, the adhesive used for the adhesive layer has poor adhesion due to poor curing. Since it is likely to occur, excellent initial adhesive strength cannot be obtained, and excellent construction suitability cannot be obtained. On the other hand, when the moisture permeability exceeds 45 g / ^m 2.24 h, the film layer is deteriorated due to the influence of moisture in the atmosphere, wind and rain, and ultraviolet rays due to sunlight during long-term use, and the adhesive used for the adhesive layer is deteriorated. Deterioration due to hydrolysis is likely to cause peeling between the pressure-sensitive adhesive sheet and the substrate, so that long-term adhesion that does not cause peeling even after long-term use cannot be obtained. Therefore, as described above, the adhesive sheet of the present invention has excellent construction suitability due to high initial adhesion strength in the construction process by setting the moisture permeability within a specific range, and long-term use does not cause peeling. Achieves both adhesion and adhesion.

In order to improve the long-term adhesion as well as the workability, the moisture permeability is ^1.2 g / m 2.24 h or more, more preferably 1.5 g / m 2.24 h or more, still more preferably ^2.5 g / ^m 2.24 h or more. The above is more preferably 4.5 g / ^m 2.24 h or more, and the upper limit is preferably 40 g / ^m 2.24 h or less, more preferably 35 g / ^m 2.24 h or less, still more preferably 30 g / ^m 2.24 h or less. Below, it is even more preferably ²⁰ g / m 2.24 h or less.
In the present invention, the moisture permeability can be adjusted mainly by the type of material constituting the film layer described later.

<UV absorber>
The surface protective layer and the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet of the present invention contain ultraviolet absorbers 1 and 2, respectively.
When the pressure-sensitive adhesive sheet of the present invention is composed of a surface protective layer and a layer including a pressure-sensitive adhesive layer, the ultraviolet absorber 1 has a maximum absorption wavelength of 300 nm or more and 360 nm or less, and is a resin used for the surface protection layer. It is preferable to have an absorption band at the maximum absorption wavelength and the maximum absorption wavelength of the resin used for the pressure-sensitive adhesive layer.
Further, when the pressure-sensitive adhesive sheet of the present invention is composed of a layer including a surface protective layer and a pressure-sensitive adhesive layer, the ultraviolet absorber 2 has a maximum absorption wavelength of 300 nm or more and 360 nm or less and is used for the pressure-sensitive adhesive layer. It is preferable to have an absorption band at the maximum absorption wavelength of the resin to be obtained.

Further, the pressure-sensitive adhesive sheet of the present invention has a film layer containing an ultraviolet absorber 3.
In relation to the ultraviolet absorber 3, the ultraviolet absorber 1 has a maximum absorption wavelength of 300 nm or more and 360 nm or less, and has a maximum absorption wavelength of the resin used for the surface protection layer and a maximum absorption wavelength of the resin used for the film layer. It is preferable to have an absorption band in.
The ultraviolet absorber 3 preferably has a maximum absorption wavelength of 300 nm or more and 360 nm or less, and has an absorption band at the maximum absorption wavelength of the resin used for the film layer and the maximum absorption wavelength of the resin used for the pressure-sensitive adhesive layer.
Further, it is preferable that the ultraviolet absorber 2 has a maximum absorption wavelength of 300 nm or more and 360 nm or less, and has an absorption band at the maximum absorption wavelength of the resin used for the pressure-sensitive adhesive layer.

When the ultraviolet absorbers 1 to 3 contained in each layer are in the above-mentioned preferred embodiment, the ultraviolet absorbers 1 to 3 are contained within a wavelength range of 300 nm or more and 360 nm or less in which the resin contained in the pressure-sensitive adhesive layer is susceptible to photodegradation. The absorption wavelength of the resin of each of the contained layers itself and the absorption wavelength of the resin of the layer immediately below the layer (when a further layer is provided under the layer) are absorbed by the ultraviolet absorber. As described above, according to the structure of the pressure-sensitive adhesive sheet of the present invention, it is possible to suppress photodegradation of the layer containing the ultraviolet absorber and the layer directly below the layer, and as a result, it exists in the bottom layer of the pressure-sensitive adhesive sheet. It becomes possible to more effectively protect the pressure-sensitive adhesive layer from deterioration due to ultraviolet rays.
In the present invention, the pressure-sensitive adhesive layer is protected from ultraviolet rays not only by the ultraviolet absorber 2 contained in the pressure-sensitive adhesive layer but also by each layer on the pressure-sensitive adhesive layer. Therefore, the adhesiveness between the pressure-sensitive adhesive layer, the substrate, and the surface protective layer or the film layer is maintained, and the pressure-sensitive adhesive sheet of the present invention can suppress deterioration over time due to ultraviolet rays, and has excellent weather resistance over a long period of time. Can be shown.

(Triazine-based UV absorber)
As the ultraviolet absorber contained in each layer of the pressure-sensitive adhesive sheet of the present invention, it is preferable that at least one of the ultraviolet absorbers 1 and 2 or at least one of the ultraviolet absorbers 1 to 3 is a triazine-based ultraviolet absorber. It is more preferable that all the ultraviolet absorbers contained in each layer are triazine-based ultraviolet absorbers. If it is a triazine-based ultraviolet absorber, it can easily exhibit excellent weather resistance, and in the case of a surface protective layer, it is difficult to discolor even by irradiation with ionizing radiation described later. Further, the triazine-based ultraviolet absorbers contained in each layer may be the same or different, or may be used alone or in combination of two or more.

As the triazine-based ultraviolet absorber, a hydroxyphenyltriazine-based ultraviolet absorber in which at least one organic group selected from a hydroxyphenyl group, an alkoxyphenyl group and an organic group containing these groups is linked to a triazine ring is more preferable. , The hydroxyphenyltriazine-based ultraviolet absorber represented by the following general formula (1) is more preferable. Since the hydroxyphenyltriazine-based ultraviolet absorber represented by the following general formula (1) has a branched structure, it is expected that it will be difficult to bleed out, and it is particularly preferable for the purpose of improving weather resistance.

In the general formula (1), R ¹¹ is a divalent organic group, R ¹² is an ester group represented by −C (= O) OR ¹⁵ , and R ¹³ , R ¹⁴ and R ¹⁵ are independent of each other. It is a monovalent organic group, and n ₁₁ and n ₁₂ are independently integers of 1 or more and 5 or less.

Examples of the divalent organic group of R ¹¹ include an aliphatic hydrocarbon group such as an alkylene group and an alkaneylene group, and an alkylene group is preferable for the purpose of improving weather resistance, and the carbon number thereof is preferably 1 or more. The upper limit is preferably 20 or less, more preferably 12 or less, still more preferably 8 or less, and particularly preferably 4 or less. The alkylene group and the alkenylene group may be linear, branched or cyclic, but the linear or branched group is preferable.
Examples of the alkylene group having 1 or more and 20 or less carbon atoms include a methylene group, a 1,1-ethylene group, a 1,2-ethylene group, a 1,3-propylene, a 1,2-propylene and a 2,2-propylene group. Various propylene groups (hereinafter, "various" means linear, branched, and those containing isomers thereof), various butylene groups, various pentylene groups, various hexylene groups, various heptylene groups, Various octylene groups, various nonylene groups, various decylene groups, various undecylene groups, various dodecylene groups, various tridecylene groups, various tetradecylene groups, various pentadecylene groups, various hexadecylene groups, various heptadecylene groups, various octadecylene groups, various nonadecilene groups, various icosilene groups. The group is mentioned.

Examples of the monovalent organic group of R ¹³ and R ¹⁴ include an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an arylalkyl group and the like, and an aromatic hydrocarbon group such as an aryl group and an arylalkyl group can be used. Aryl groups are preferred. Of these, a phenyl group is preferable as the monovalent organic group of R ¹³ and R ¹⁴ .
As the aryl group, an aryl group having preferably 6 or more carbon atoms, preferably 20 or less as an upper limit, more preferably 12 or less, still more preferably 10 or less, for example, a phenyl group, various methylphenyl groups, various ethylphenyl groups, Examples thereof include various dimethylphenyl groups, various propylphenyl groups, various trimethylphenyl groups, various butylphenyl groups, various naphthyl groups and the like. As the arylalkyl group, an arylalkyl group having preferably 7 or more carbon atoms, preferably 20 or less as an upper limit, more preferably 12 or less, still more preferably 10 or less, for example, a benzyl group, a phenethyl group, various phenylpropyl groups, etc. Examples thereof include various phenylbutyl groups, various methylbenzyl groups, various ethylbenzyl groups, various propylbenzyl groups, various butylbenzyl groups, various hexylbenzyl groups and the like.

^Examples of the monovalent organic group of R15 include an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an arylalkyl group and the like, and an aliphatic hydrocarbon group such as an alkyl group and an alkenyl group is preferable. Is more preferable. That is, as R ¹² , an alkyl ester group and an alkenyl ester group are preferable, and an alkyl ester group is more preferable.
As the alkyl group, an alkyl group having a carbon number of preferably 1 or more, more preferably 2 or more, still more preferably 6 or more, and an upper limit of preferably 20 or less, more preferably 16 or less, still more preferably 12 or less, for example, methyl. Groups, ethyl groups, various propyl groups, various butyl groups, various pentyl groups, various hexyl groups, various octyl groups, various nonyl groups, various decyl groups, various undecyl groups, various dodecyl groups, various tridecyl groups, various tetradecyl groups, various Examples thereof include a pentadecyl group, various hexadecyl groups, various heptadecyl groups, various octadecyl groups, various nonadecil groups, and various icosyl groups.
As the alkenyl group, an alkenyl group having a carbon number of preferably 2 or more, more preferably 3 or more, still more preferably 6 or more, and an upper limit of preferably 20 or less, more preferably 16 or less, still more preferably 12 or less, for example, vinyl. Groups, various propenyl groups, various butenyl groups, various pentenyl groups, various hexenyl groups, various octenyl groups, various nonenyl groups, various decenyl groups, various undecenyl groups, various dodecenyl groups, various tridecenyl groups, various tetradecenyl groups, various pentadecenyl groups, Examples thereof include various hexadecenyl groups, various heptadecenyl groups, various octadecenyl groups, various nonadesenyl groups, and various icosenyl groups.

More specifically, as the hydroxyphenyltriazine compound represented by the general formula (1), R ¹¹ is an alkylene group having 1 or more carbon atoms and 20 or less carbon atoms, and R ¹² and R ¹⁵ are alkyl groups having 1 or more carbon atoms and 20 or less carbon atoms. It is an alkyl ester group as a group, R ¹³ and R ¹⁴ are aryl groups having 6 or more carbon atoms and 20 or less carbon atoms, and a hydroxyphenyltriazine compound having n ₁₁ and n ₁₂ of 1 is preferable, and R ¹¹ has 1 or more carbon atoms and 12 carbon atoms. The following alkylene groups, R ¹² and R ¹⁵ are alkyl ester groups having 2 or more and 16 or less carbon atoms, and R ¹³ and R ¹⁴ are aryl groups having 6 or more and 12 or less carbon atoms, and n ₁₁ And a hydroxyphenyltriazine compound having n ₁₂ of 1 is more preferable, R ¹¹ is an alkylene group having 1 or more and 8 or less carbon atoms, and R ¹² and R ¹⁵ are alkyl groups having 6 or more and 12 or less carbon atoms. R ¹³ and R ¹⁴ are aryl groups having 6 or more and 10 or less carbon atoms, hydroxyphenyltriazine compounds having n ₁₁ and n ₁₂ of 1 are more preferable, and R ¹¹ is an alkylene group having 1 or more and 4 or less carbon atoms. , R ¹² and R ¹⁵ are ester groups which are alkyl groups having 8 carbon atoms, R ¹³ and R ¹⁴ are phenyl groups, and hydroxyphenyl triazine compounds having n ₁₁ and n ₁₂ of 1 are particularly preferable.

As the hydroxyphenyltriazine compound represented by the general formula (1), more specifically, an ester group represented by the following chemical formula (2) in which R ¹¹ is an ethylene group and R ¹² and R ¹⁵ are isooctyl groups. , R ¹³ and R ¹⁴ are phenyl groups, and n ₁₁ and n ₁₂ are 1 hydroxyphenyltriazine compounds, ie 2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl) -4, 6-Bis (4-phenylphenyl) -1,3,5-triazine is preferable, and this hydroxyphenyltriazine compound is available as a commercially available product (“TINUVIN479”, manufactured by BASF), for example.
The triazine-based ultraviolet absorber may be used alone or in combination of two or more.

Further, each layer of the pressure-sensitive adhesive sheet may contain an ultraviolet absorber other than the triazine-based ultraviolet absorber. Examples of UV absorbers other than triazine-based UV absorbers include cyanoacrylate-based UV absorbers, benzotriazole-based UV absorbers, and benzophenone-based UV absorbers, which are used alone or in combination of two or more. You may.

The content of the ultraviolet absorber ₁ in the surface protective layer is not particularly limited as long as the absorbance A1 is 0.8 or more, but usually 0.5 part by mass with respect to 100 parts by mass of the resin constituting the surface protective layer. More than 10.0 parts by mass is preferable, 1.0 part by mass or more and 9.5 parts by mass or less is more preferable, 2.0 parts by mass or more and 9.0 parts by mass or less is further preferable, and 2.0 parts by mass or more and 8. More preferably, it is 5 parts by mass or less.

The content of the ultraviolet absorber 3 in the film layer is not particularly limited as long as the absorbance A1 is 0.8 or _more , but is usually 0.1 part by mass with respect to 100 parts by mass of the resin constituting the film layer. More than 10.0 parts by mass is preferable, 0.1 parts by mass or more and 9.5 parts by mass or less is more preferable, 0.1 parts by mass or more and 9.0 parts by mass or less is further preferable, and 0.1 parts by mass or more and 8. More preferably, it is 5 parts by mass or less.

The content of the ultraviolet absorber 2 in the pressure-sensitive adhesive layer is not particularly limited as long as the absorbance A ₂ is 1.2 or more, but is usually 0.1 with respect to 100 parts by mass of the resin constituting the pressure-sensitive adhesive layer. It is preferably by mass or more and 10.0 parts by mass or less, more preferably 0.2 parts by mass or more and 9.5 parts by mass or less, further preferably 0.3 parts by mass or more and 9.0 parts by mass or less, and 0.4 parts by mass or more. More preferably, it is 8.5 parts by mass or less.

<Surface protective layer>
The surface protective layer may be formed of a single layer, or may be formed of two or more layers of the same type or different types.
The surface protective layer preferably contains a cured product of a curable resin composition in order to improve surface properties such as scratch resistance of the pressure-sensitive adhesive sheet.
Further, the ratio of the cured product of the curable resin composition to the total resin components constituting the surface protective layer is preferably 50% by mass or more, more preferably 70% by mass or more, and 90% by mass. The above is more preferable, and 100% by mass is even more preferable.
Examples of the cured product of the curable resin include a cured product of a thermosetting resin composition, a cured product of an ionizing radiation curable resin composition, or a mixture thereof. Among these, a cured product of an ionizing radiation curable resin composition is preferable in order to increase the crosslink density of the surface protective layer and improve scratch resistance and light resistance. Further, the cured product of the ionizing radiation curable resin composition can be applied without a solvent and is easy to handle. Therefore, the cured product of the electron beam curable resin composition is more preferable.
From the above, it is one of the preferable embodiments that the surface protective layer is made of only a cured product (100% by mass) of the ionizing radiation curable resin composition.

The thermosetting resin composition is a composition containing at least a thermosetting resin, and is a resin composition that is cured by heating. Examples of the thermosetting resin include acrylic resin, urethane resin, phenol resin, urea melamine resin, epoxy resin, unsaturated polyester resin, silicone resin and the like. To the thermosetting resin composition, a curing agent is added to these curable resins as needed.

(Ionizing radiation curable resin)
The ionizing radiation curable resin composition is a composition containing a compound having an ionizing radiation curable functional group (hereinafter, also referred to as “ionizing radiation curable compound”). The ionizing radiation curable functional group is a group that is crosslinked and cured by irradiation with ionizing radiation, and a functional group having an ethylenic double bond such as a (meth) acryloyl group, a vinyl group, and an allyl group is preferable.
Further, ionizing radiation means an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing or cross-linking a molecule, and usually, an ultraviolet ray (UV) or an electron beam (EB) is used. Electromagnetic waves such as X-rays and γ-rays, and charged particle beams such as α-rays and ion rays are also included.
Specifically, the ionizing radiation curable compound can be appropriately selected and used from the polymerizable monomers and polymerizable oligomers conventionally used as ionizing radiation curable resins.

As the polymerizable monomer, a (meth) acrylate-based monomer having a radically polymerizable unsaturated group in the molecule is preferable, and a polyfunctional (meth) acrylate monomer is particularly preferable. Here, "(meth) acrylate" means "acrylate or methacrylate".
Examples of the polyfunctional (meth) acrylate monomer include a (meth) acrylate monomer having two or more ionizing radiation curable functional groups in the molecule and having at least a (meth) acryloyl group as the functional group.
In order to improve the processing characteristics, scratch resistance and light resistance, the number of functional groups of the polyfunctional (meth) acrylate monomer is preferably 2 or more and 8 or less, more preferably 2 or more and 6 or less, and further preferably 2 or more and 4 or less. 2, 2 or more and 3 or less are more preferable. These polyfunctional (meth) acrylates may be used alone or in combination of two or more.

Examples of the polymerizable oligomer include (meth) acrylate oligomers having two or more ionizing radiation curable functional groups in the molecule and having at least a (meth) acryloyl group as the functional groups. Examples thereof include urethane (meth) acrylate oligomers, epoxy (meth) acrylate oligomers, polyester (meth) acrylate oligomers, polyether (meth) acrylate oligomers, polycarbonate (meth) acrylate oligomers, acrylic (meth) acrylate oligomers and the like.
Further, as the polymerizable oligomer, a highly hydrophobic polybutadiene (meth) acrylate-based oligomer having a (meth) acrylate group in the side chain of the polybutadiene oligomer, and a silicone (meth) acrylate-based oligomer having a polysiloxane bond in the main chain. In a molecule such as an aminoplast resin (meth) acrylate-based oligomer in which an aminoplast resin having many reactive groups in a small molecule is modified, or a novolak type epoxy resin, a bisphenol type epoxy resin, an aliphatic vinyl ether, an aromatic vinyl ether, etc. There are oligomers and the like having cationically polymerizable functional groups.

These polymerizable oligomers may be used alone or in combination of two or more. Urethane (meth) acrylate oligomer, epoxy (meth) acrylate oligomer, polyester (meth) acrylate oligomer, polyether (meth) acrylate oligomer, polycarbonate (meth) acrylate oligomer to improve processing properties, scratch resistance and light resistance. , Acrylic (meth) acrylate oligomers are preferable, urethane (meth) acrylate oligomers and polycarbonate (meth) acrylate oligomers are more preferable, and urethane (meth) acrylate oligomers are even more preferable.

The number of functional groups of these polymerizable oligomers is preferably 2 or more and 8 or less, more preferably 6 or less, still more preferably 4 or less, in order to improve processing characteristics, scratch resistance and light resistance. 3, 3 or less is even more preferable.
The weight average molecular weight of these polymerizable oligomers is preferably 2,500 or more and 7,500 or less, more preferably 3,000 or more and 7,000 or less, in order to improve processing characteristics, scratch resistance and light resistance. It is preferable, and more preferably 3,600 or more and 6,000 or less. Here, the weight average molecular weight is an average molecular weight measured by GPC analysis and converted into standard polystyrene.

A monofunctional (meth) acrylate can be used in combination with the ionizing radiation curable resin composition for the purpose of reducing the viscosity of the ionizing radiation curable resin composition. These monofunctional (meth) acrylates may be used alone or in combination of two or more.

(Light stabilizer)
The surface protective layer preferably contains another weather resistant agent in addition to the above-mentioned ultraviolet absorber 1, and more preferably contains a light stabilizer. In particular, since the surface protective layer is the layer to which ultraviolet rays are first incident among the layers constituting the pressure-sensitive adhesive sheet, it is preferable to contain a light stabilizer. The light stabilizer may be used alone or in combination of two or more.
The light stabilizer is preferably a hindered amine-based light stabilizer. When the surface protective layer contains an ultraviolet absorber 1, particularly a triazine-based ultraviolet absorber and a hindered amine-based light stabilizer, the effect of suppressing bleed-out is enhanced, and the weather resistance can be further improved. As described above, it is preferable that the surface protective layer contains a triazine-based ultraviolet absorber as the ultraviolet absorber 1 and further contains a hindered amine-based light stabilizer.

Further, the surface protective layer preferably contains, as a hindered amine-based light stabilizer, one or both of the non-reactive light stabilizer and the reactive light stabilizer with the resin used for the surface protective layer.
(Non-reactive hindered amine-based light stabilizer)
The non-reactive hindered amine-based light stabilizer is, for example, one that does not have an ethylenic double bond that can be polymerized with an ionizing radiation curable resin composition. As the non-reactive hindered amine-based light stabilizer, only one kind may be used, or two or more kinds may be used.
Non-reactive hindered amine-based light stabilizers include 4-benzoyloxy-2,2,6,6-tetramethylpiperidin, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sevacate, bis (1-octyl oshiki-2,2,6,6-tetramethyl-4-piperidinyl) sevakate, bis (1,2,2) , 6,6-Pentamethyl-4-piperidinyl) sevakate, methyl (1,2,2,6,6-pentamethyl-4-piperidinyl) sevakate, 2,4-bis [N-butyl-N- (1-cyclohexyloxy) -2,2,6,6-tetramethyl-4-piperidinyl) amino] -6- (2-hydroxyethylamine) -1,3,5-triazine), tetrakis (1,2,2,6,6-pentamethyl) -4-piperidyl) -1,2,3,4-butanetetracarboxylate, bis- (1,2,2,6,6-pentamethyl-4-piperidyl) -2- (3,5-di-t-) Butyl-4-hydroxy-benzyl) -2-n-butylmalonate and the like can be mentioned.

(Reactive hindered amine-based light stabilizer)
The reactive hindered amine-based light stabilizer is, for example, one having an ethylenic double bond polymerizable with an ionizing radiation curable resin composition. Examples of the group having an ethylenically double bond include a (meth) acryloyl group, a crotonoyl group, a vinyl group and an allylic group, and among these, a (meth) acryloyl group is preferable. That is, the reactive hindertoamine-based light stabilizer preferably has a (meth) acryloyl group.
The number of ethylenic double bonds in the reactive hindered amine-based light stabilizer is not particularly limited, and may be one or two or more. Further, only one kind of reactive hindered amine-based light stabilizer may be used, or two or more kinds may be used.

Reactive hindered amine-based photostabilizers include 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine and 4- (meth) acryloylamino-2,2,6,6-tetra. Methylpiperidin, 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6-pentamethylpiperidin, 4-cyano -4- (Meta) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine and 4-crotonoylamino-2,2,6 , 6-Tetramethylpiperidin, the compound of CAS number 1010692-24-6 and the compound of CAS number 1010692-21-3.
Reactive hindered amine-based photostabilizers having two or more ethylenic double bonds include 1- (meth) acryloyl-4- (meth) acryloylamino-2, 2,6,6-tetramethylpiperidine, 1 -(Meta) acryloyl-4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotoyloxy-2,2,6,6-tetramethyl Examples include piperidine, the compound of CAS No. 1954659-42-7 and the compound of CAS No. 106092-23-5.

The lower limit of the content of the light stabilizer in the surface protective layer is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and 2 parts by mass or more with respect to 100 parts by mass of the resin constituting the surface protective layer. More preferred. The upper limit of the content of the light stabilizer in the surface protective layer is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and further preferably 6 parts by mass or less with respect to 100 parts by mass of the resin constituting the surface protective layer. preferable. If the content of the light stabilizer is within the above range, it can be expected that the weather resistance will be better without bleeding out.

(Additive)
If necessary, the surface protective layer may contain an additive other than the above-mentioned ultraviolet absorber 1 and the above-mentioned light stabilizer which is preferably used. Examples of the above-mentioned additives include abrasion resistance improver, polymerization accelerator, polymerization inhibitor, cross-linking agent, infrared absorber, antistatic agent, adhesiveness improver, leveling agent, tincture imparting agent, coupling agent, and plasticizer. , Antifoaming agent, solvent, colorant and the like. The above additives can be used alone or in combination of two or more. The amount of the additive added is not particularly limited and can be appropriately set according to the required characteristics and the like.

(thickness)
The thickness of the surface protective layer is not particularly limited and can be appropriately specified as long as the effect of the present invention is not impaired, but bleed-out can be suppressed, excellent weather resistance, and the surface protective layer or the film layer. The lower limit is preferably 1.5 μm or more, more preferably 2 μm or more, still more preferably 3 μm or more, in order to have adhesiveness and further improve processing characteristics and scratch resistance. The upper limit of the thickness of the surface protective layer is preferably 20 μm or less, more preferably 15 μm or less, still more preferably 10 μm or less.

<Film layer>
The pressure-sensitive adhesive sheet of the present invention has a film layer as the A layer, preferably a surface protective layer, a film layer, and a pressure-sensitive adhesive layer in this order. The film layer is a layer provided for the purpose of providing the above-mentioned predetermined moisture permeability and protecting the pressure-sensitive adhesive layer.

As the resin constituting the film layer, for example, a polyolefin resin, a polyester resin, an acrylic resin, a polycarbonate resin, a polyurethane resin, a polystyrene resin, a vinyl chloride resin, a vinyl acetate resin and the like are preferably mentioned. Of these, polyolefin resins are preferable in order to improve weather resistance. Further, the polyolefin resin and the vinyl chloride resin are preferable, and the polyolefin resin is more preferable, considering that the moisture permeability is within the above range and the long-term adhesion is improved as well as the workability. Examples of the polyolefin resin include polypropylene, polyethylene and the like, and polypropylene is preferable. In the present invention, the above resins can be used alone or in combination of two or more. When a plurality of types are combined, a film layer made of various single resins may be combined, or a plurality of types of resins may be mixed and used as one film layer.

More specifically, the polyolefin resin includes homopolymers of olefins such as ethylene, propylene and butene; various copolymers such as block copolymers of ethylene-propylene and random copolymers; at least one of ethylene and propylene. And a polymer with at least one other olefin such as butene, pentene, hexene; a polymer of at least one of ethylene and propylene with at least one other monomer such as vinyl acetate and vinyl alcohol; And so on.
Among the above, polyethylene-based resin containing ethylene as a constituent unit and polypropylene-based resin containing propylene as a constituent unit are preferable, and polypropylene-based resin is preferable in order to easily keep the moisture permeability within the above range and to improve construction suitability and long-term adhesion. Resin is preferred.

It is preferable to adjust the moisture permeability by adjusting the thickness of a layer in which a resin such as a film layer can be used because it is easy and more reliable. In order to keep the moisture permeability of the pressure-sensitive adhesive sheet within the above-mentioned predetermined range in the present invention, the thickness of the film layer or the like is set in consideration of the ratio of the thickness to the total thickness of the pressure-sensitive adhesive sheet in the laminated structure of the pressure-sensitive adhesive sheet. It is preferably in a predetermined range depending on the type of the material constituting these layers, preferably the resin.
In order to facilitate the moisture permeability of the pressure-sensitive adhesive sheet within the above-mentioned predetermined range, the thickness of the film layer is preferably 40 μm or more and 200 μm or less when a polyethylene-based resin, a polypropylene-based resin, and a vinyl chloride-based resin is used. It may be selected from the range in consideration of the laminated structure of the adhesive sheet and the desired moisture permeability.

More specifically, the polyethylene-based resin may be a homopolymer of ethylene, that is, polyethylene, or ethylene and another comonomer copolymerizable with ethylene (eg, propylene, 1-butene, 1-). It may be a copolymer with α-olefin such as hexene and 1-octene, vinyl acetate, vinyl alcohol and the like). Examples of polyethylene include high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), ultra-low-density polyethylene (VLDPE), and ultra-high molecular weight polyethylene (UHMWPE). ), Crosslinked polyethylene (PEX) and the like. These polyethylene-based resins may be used alone or in combination of two or more.

The polypropylene-based resin may be a homopolymer of propylene, that is, polypropylene, or propylene and another comonomer copolymerizable with propylene (for example, ethylene, 1-butene, 1-hexene, 1-octene, etc.). Α-Olefin; vinyl acetate, vinyl alcohol, etc.) may be a copolymer. These polypropylenes may be used alone or in combination of two or more.

When a homopolymer of propylene (polypropylene) is used, the moisture permeability of the film layer can be adjusted by adjusting the crystallinity, and as a result, the moisture permeability of the pressure-sensitive adhesive sheet can be adjusted. Generally, the higher the crystallinity, the lower the moisture permeability of the polypropylene resin. When the polypropylene resin having a thickness in the range of 40 μm or more and 200 μm or less is used as the film layer, the crystallinity is preferably 30% or more, more preferably 40% or more, and the upper limit is preferably 80% or less. It is preferably 70% or less.
Further, when a homopolymer of propylene (polypropylene) is used, the moisture permeability of the film layer can be adjusted by adjusting the mass ratio of the isotactic polypropylene and the atactic polypropylene. In general, the moisture permeability of the film layer can be reduced by adding the isotactic polypropylene as compared with the case where the ratio of the atactic polypropylene in the polypropylene is 100% by mass. In this case, the mass ratio of the atactic polypropylene to the isotactic polypropylene is preferably 0/100 to 20/80 in consideration of the ease of adjusting the moisture permeability.

When a vinyl chloride resin is used, the vinyl chloride resin is a copolymer of a homopolymer of a vinyl chloride monomer, that is, polyvinyl chloride or a vinyl chloride monomer, and a monomer copolymerizable with the vinyl chloride monomer. The copolymer thus obtained can also be used.
Examples of the monomer copolymerizable with the vinyl chloride monomer include vinyl esters such as vinyl acetate and vinyl propionate; acrylic acid esters such as methyl acrylate and butyl acrylate; and methacrylate esters such as methyl methacrylate and ethyl methacrylate; butyl malate and the like. Maleic acid esters such as diethyl malate; Fumaric acid esters such as dibutyl fumarate and diethyl fumarate; Vinyl ethers such as vinyl methyl ether, vinyl butyl ether and vinyl octyl ether; Vinyl cyanide such as acrylonitrile and methacrylonitrile Olefins such as ethylene, propylene, butylene and styrene; Dienes such as isoprene and butadiene; Vinylidene halides other than vinyl chloride such as vinylidene chloride and vinyl bromide, vinyl halides; Allyl phthalates such as diallylphthalate , Etc. can be mentioned. These monomers may be used alone or in combination of two or more.

The average degree of polymerization of the vinyl chloride resin is preferably 500 or more and 4000 or less, more preferably 700 or more and 3900 or less, and 1000 or more in order to easily keep the moisture permeability within the above range and to improve the long-term adhesion as well as the workability. 3800 or less is more preferable. When the average degree of polymerization is within the above range, excellent mechanical strength and moldability can also be obtained. In the present specification, the average degree of polymerization is the average degree of polymerization measured in accordance with JIS K6721.

In the present embodiment, when a vinyl chloride resin is used, a plasticizer may be added in order to easily keep the moisture permeability within the above range, improve the long-term adhesion as well as the workability, and further improve the processability. preferable.
The plasticizer is not particularly limited as long as it is compatible with the vinyl chloride resin, and is, for example, dibutyl phthalate (DBP), dioctyl phthalate (DOP), diisononyl phthalate (DINP), diisodecyl phthalate (Plasticizer). DIDP), phthalic acid-based plasticizers such as diundecyl phthalate (DUP); adipic acid-based plasticizers such as dibutyl adipate; phosphate-based plasticizers such as tributyl phosphate, tricresyl phosphate, triphenyl phosphate; trimellitic acid Trimellitic acid-based plasticizers such as tributyl acid and trioctyltrimellitic acid; various known polyester-based plasticizers such as adipic acid-based polyester; citrate esters such as acetyltributylcitrate and acetyltrioctylcitrate; and the like can be mentioned. .. Among them, phthalic acid-based plasticizers, adipic acid-based plasticizers, and polyester-based plasticizers are preferable in order to easily keep the moisture permeability within the above range, improve long-term adhesion as well as workability, and further improve processability. , Phtalic acid-based plasticizers and polyester-based plasticizers are more preferable. In addition, these plasticizers may be used alone or in combination of two or more.

The content of the plasticizer may be appropriately adjusted and used according to the desired moisture permeability, and it cannot be said unconditionally, but usually, the additive of the plasticizer is increased and the moisture permeability of the vinyl chloride resin is increased. Tend to do. In consideration of this point, the content of the plasticizer is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and further preferably 25 parts by mass or more with respect to 100 parts by mass of the vinyl chloride resin. The upper limit is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and further preferably 35 parts by mass or less. By setting the content of the plasticizer within the above range, it becomes easy to adjust the moisture permeability to a desired range, and it is possible to improve the long-term adhesion as well as the work suitability. Further, by setting the content of the plasticizer to 20 parts by mass or more, the vinyl chloride resin can be made flexible and the processability can be improved. On the other hand, when the content of the plasticizer is 50 parts by mass or less, the bleed-out of the plasticizer is suppressed, the moisture permeability can be stably adjusted to a desired range, and the long-term adhesion can be improved as well as the work suitability.

In particular, when a phthalate ester-based plasticizer is used, for example, in order to easily adjust the moisture permeability to a desired range and to improve the workability and long-term adhesion, the content thereof is 100 mass of vinyl chloride resin. It is preferably 25 parts by mass or more, more preferably 30 parts by mass or more, still more preferably 35 parts by mass or more, and the upper limit is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, still more preferably 45 parts by mass or more. It is 40 parts by mass or less. When a polyester-based plasticizer is used, its content is preferably 15 parts by mass or more, more preferably 18 parts by mass or more, and further preferably 20 parts by mass or more with respect to 100 parts by mass of the vinyl chloride resin. The upper limit is preferably 35 parts by mass or less, more preferably 30 parts by mass or less, and further preferably 25 parts by mass or less.

(Additive)
The film layer may contain additives, if necessary. As the additive, for example, those exemplified as additives that can be blended in the surface protective layer can be used. The above additives can be used alone or in combination of two or more. The amount of the additive added is not particularly limited and can be appropriately set according to the required characteristics and the like.

(thickness)
The thickness of the film layer is not particularly limited and can be appropriately specified as long as the effect of the present invention is not impaired. The lower limit is preferably 20 μm or more, more preferably 40 μm or more, in order to improve the protection of the pressure-sensitive adhesive layer and the handling of the pressure-sensitive adhesive sheet while maintaining the adhesion between the surface protective layer and the pressure-sensitive adhesive layer. 60 μm or more is further preferable, the upper limit is 150 μm or less, 120 μm or less is more preferable, and 100 μm or less is further preferable.

<Transparent resin layer>
The pressure-sensitive adhesive sheet of the present invention may have a transparent resin layer in addition to the film layer. It is preferable to use the film layer and the transparent resin layer in combination in order to improve the weather resistance, easily adjust the moisture permeability within the above range, and improve the long-term adhesion as well as the workability. In this case, the transparent resin layer may be provided in contact with the film layer, and it is preferable that the transparent resin layer, the film layer, and the surface protective layer are provided in this order. If the film layer has a predetermined moisture permeability, excellent workability and long-term adhesion can be obtained. Therefore, it is not necessary to provide a transparent resin layer, and the workability and long-term adhesion are improved. If required at an extremely high level, a transparent resin layer may be provided. In either case, the necessity of the transparent resin layer may be determined according to the desired construction suitability and long-term adhesion.

The resin constituting the transparent resin layer can be selected from those exemplified as the resin constituting the above-mentioned film layer. Further, the polyolefin resin and the vinyl chloride resin are preferable, and the polyolefin resin is more preferable, considering that the moisture permeability is within the above range and the long-term adhesion is improved as well as the workability.
The transparent resin layer may or may not contain an ultraviolet absorber. The pressure-sensitive adhesive sheet of the present invention may be determined in consideration of the required weather resistance. When an ultraviolet absorber is used, it may be selected from the ultraviolet absorbers exemplified as those that can be contained in the above film layer, and the amount used thereof is also the same.
The thickness of the transparent resin layer may be appropriately selected from the preferable range of the thickness of the film layer, considering that the moisture permeability is within the above range and the long-term adhesion is improved as well as the workability.

<Adhesive layer>
The pressure-sensitive adhesive composition used for the pressure-sensitive adhesive layer is not particularly limited, and known ones can be used. Resins used for the pressure-sensitive adhesive include acrylic resin, polyester resin, polyurethane resin, polyolefin resin, polyamide resin, styrene resin, cellulose resin, imide resin, vinyl chloride resin, polystyrene resin, fluororesin, silicone resin, and rubber resin. Examples include resin. These resins can be used alone or in admixture of two or more. Among these, acrylic resin, polyester resin, polyurethane resin, silicone resin, and rubber resin are preferable, and acrylic resin is more preferable, because they are excellent in adhesiveness, weather resistance, and durability. Further, in order to keep the moisture permeability within the above range and improve the long-term adhesion as well as the workability, the polyolefin resin and the vinyl chloride resin are preferable, and the polyolefin resin is more preferable.

Examples of the acrylic resin include an acrylic acid ester copolymer obtained by copolymerizing an acrylic acid ester with another monomer.
Examples of the acrylic acid ester include ethyl acrylate, -n-butyl acrylate, -2-ethylhexyl acrylate, isooctyl acrylate, isononyl acrylate, hydroxylethyl acrylate, propylene glycol acrylate, acrylamide, glycidyl acrylate and the like. Be done. These acrylic acid esters may be used alone or in combination of two or more.
Examples of the above other monomers include methyl acrylate, methyl methacrylate, styrene, acrylonitrile, vinyl acetate, acrylic acid, methacrylic acid, itaconic acid, hydroxylethyl acrylate, hydroxylethyl methacrylate, propylene glycol acrylate, and acrylamide. Examples thereof include methacrylic acid, glycidyl acrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, -tert-butylaminoethyl methacrylate, n-ethylhexyl methacrylate and the like. These other monomers may be used alone or in combination of two or more.

The pressure-sensitive adhesive layer can be formed by cross-linking and curing the pressure-sensitive adhesive composition by heating or light irradiation. Therefore, the pressure-sensitive adhesive composition may contain a cross-linking agent. As the cross-linking agent, known ones can be used, and examples thereof include an epoxy-based cross-linking agent, an isocyanate-based cross-linking agent, and a metal chelate-based cross-linking agent. These cross-linking agents may be used alone or in combination of two or more. The cross-linking agent is usually about 0.1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the resin used for the pressure-sensitive adhesive.

(Additive)
Further, the pressure-sensitive adhesive composition according to the present invention may contain additives, if necessary. Examples of the additive include lubricants, plasticizers, fillers, fillers, antistatic agents, antiblocking agents, light stabilizers, colorants and the like. The above additives can be used alone or in combination of two or more. The amount of the additive added is not particularly limited and can be appropriately set according to the required characteristics and the like.
The pressure-sensitive adhesive composition can be prepared by mixing each of the above-mentioned components by a known method, kneading and dispersing as necessary. Further, in order to form the pressure-sensitive adhesive layer A layer, a coating liquid containing the pressure-sensitive adhesive composition can be used, and in order to adjust the viscosity of the coating liquid, a diluting solvent is added to the pressure-sensitive adhesive composition to form each component. May be mixed.

(thickness)
The thickness of the pressure-sensitive adhesive layer is not particularly limited and can be appropriately specified as long as the effect of the present invention is not impaired, but it has excellent weather resistance and adhesion to the surface protective layer or the film layer. For the purpose of maintaining the adhesiveness with the substrate, 1 μm or more is preferable, the lower limit is more preferably 5 μm or more, further preferably 10 μm or more, and the upper limit is preferably 100 μm or less, more preferably 50 μm or less, still more preferably 30 μm or less. ..

(Other layers)
The pressure-sensitive adhesive sheet of the present invention may have a primer layer in order to improve the interlayer adhesion of each layer.
The primer layer is preferably composed of at least a binder resin, and is a layer that may further contain a weathering agent such as an ultraviolet absorber and a light stabilizer, if necessary, and is a resin composition containing at least a binder resin. It is preferable that the layer is made of a resin composition containing a weathering agent such as an ultraviolet absorber and a light stabilizer.

As the binder resin, urethane resin, acrylic polyol resin, acrylic resin, ester resin, amide resin, butyral resin, styrene resin, urethane-acrylic copolymer, polycarbonate-based urethane-acrylic copolymer (carbonate bond to the polymer main chain). Urethane-acrylic copolymer derived from a polymer (polycarbonate polyol) having two or more hydroxyl groups at the terminal and side chains), vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-acrylic co-weight Resins such as a coalesced resin, a chlorinated propylene resin, a nitrocellulose resin (nitrated cotton), and a cellulose acetate resin are preferably mentioned, and these can be used alone or in combination of two or more. For example, a mixture of a polycarbonate-based urethane-acrylic copolymer and an acrylic polyol resin can be used as the binder resin.
Further, if necessary, a curing agent such as an isocyanate compound such as hexamethylene disosocyanate may be used.

The thickness of the primer layer is preferably 1 μm or more and 10 μm or less, more preferably 2 μm or more and 8 μm or less, and further preferably 3 μm or more and 6 μm or less.

The pressure-sensitive adhesive sheet of the present invention may further have a decorative layer in order to improve the design. The decorative layer is provided between the film layer and the surface protective layer, or between the film layer and the pressure-sensitive adhesive layer.

The decorative layer may be, for example, a colored layer that covers the entire surface (so-called solid colored layer), or may be a pattern layer formed by printing various patterns using ink and a printing machine. It may be good, or it may be a combination of these.
The pattern given by the decorative layer may be selected as desired without particular limitation, and for example, a wood grain pattern or a marble pattern (for example, travertin marble) that imitates the appearance of the board surface of various trees such as cedar, cypress, and pine. Pattern), stone pattern that imitates the surface of rock such as the open surface of a granite board, cloth pattern that imitates cloth grain or cloth-like pattern, leather (leather grain) pattern that expresses leather grain, tiled pattern, brick Examples include patterns such as pile patterns, hairlines, perforated grooves, satin finishes, grain, letters, symbols, geometric patterns, parquet, patchwork, block patterns, etc. that combine these patterns. Further, as a pattern in which these are combined, for example, an artificial stone in which crushed stone such as marble is mixed with white cement, hardened, and polished to be finished like marble, that is, a pattern like so-called artificial marble can be mentioned.

The thickness of the decorative layer may be appropriately selected according to the desired pattern, but is preferably 0.5 μm or more and 20 μm or less, and 1 μm or more and 10 μm or less in order to conceal the ground color of the substrate and improve the design. More preferably, it is more preferably 2 μm or more and 5 μm or less.

<Manufacturing method of adhesive sheet>
As a method for producing the pressure-sensitive adhesive sheet of the present invention, a known method can be used.
For example, first, a resin composition for forming a surface protective layer is applied onto a film to be a film layer, and then the surface protective layer is formed by curing by heating or light irradiation. Next, the pressure-sensitive adhesive composition is applied to the surface of the film layer opposite to the surface on which the surface protective layer is formed, cured in the same manner as described above, and finally the release sheet is removed. The adhesive sheet can be manufactured by the above steps.
As the release sheet, conventionally known release sheets such as separate paper, separate film, separate paper, release film, and release paper can be preferably used.

In the pressure-sensitive adhesive sheet of the present invention, since the pressure-sensitive adhesive layer is protected by the above-mentioned structure, the adhesion between the substrate, the film layer and the surface protection layer is ensured, and the weather resistance is excellent for a long time. Therefore, the adhesive sheet of the present invention includes exterior members such as gate posts and window frames, members exposed to sunlight such as near windows even for indoor use, outdoor signboards such as advertising towers and field signboards, vehicles such as motorcycles and automobiles, and playsets. It can be used for marking films used in the above, protective films for ultraviolet rays, and the like.

[Cosmetic material]
The decorative member of the present invention has the above-mentioned pressure-sensitive adhesive sheet and substrate of the present invention so that the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet and the substrate face each other. Further, the decorative member of the present invention preferably has an adhesive layer between the pressure-sensitive adhesive layer and the substrate in order to further improve the adhesion.
FIG. 2 is a cross-sectional view showing one of the preferred embodiments of the decorative member 200 of the present invention.
The decorative member 200 of FIG. 2 has a pressure-sensitive adhesive sheet 100 and a base material 210 having a surface protective layer 110, a film layer 130, and a pressure-sensitive adhesive layer 120 in this order so that the pressure-sensitive adhesive layer 20 and the base material 210 face each other. Moreover, the adhesive layer 220 is provided between the pressure-sensitive adhesive layer 20 and the substrate 210.

The substrate may be appropriately selected depending on the intended use of the decorative member, and is not particularly limited, and examples thereof include flat plates of various materials, plate materials such as curved plates, three-dimensional shaped articles, sheets (or films), and the like.
For example, wood single board made of various kinds of wood such as cedar, cypress, pine, and lauan, wood plywood, laminated wood, particle board, wood substrate such as MDF (medium density fiber board); metal such as iron, copper, aluminum, and titanium. Substrate: Ceramics such as glass and ceramics, non-cement ceramic materials such as gypsum, ceramic substrate such as ALC (lightweight bubble concrete) board; acrylic resin, polyester resin, polystyrene resin, polyolefin resin such as polypropylene, ABS (acrylonitrile-butadiene) -A styrene copolymer) resin, a phenol resin, a vinyl chloride resin, a cellulose resin, a resin substrate such as rubber, and the like can be mentioned. In addition, these substrates can be used alone or in combination of two or more.

The substrate may be appropriately selected from the above depending on the application, and when the marking film used for a member exposed to sunlight even for outdoor or indoor applications, the UV resistant protective film, etc. are used, the metal substrate and the substrate It is preferably composed of at least one kind of substrate selected from resin substrates.

The thickness of the substrate may be appropriately selected depending on the intended use and material, and is preferably 0.1 mm or more and 10 mm or less, more preferably 0.3 mm or more and 5 mm or less, and further preferably 0.5 mm or more and 3 mm or less.

The adhesive used for the adhesive layer is not particularly limited, and known adhesives can be used. For example, a moisture-curable adhesive, an anaerobic curable adhesive, a dry-curable adhesive, and a UV-curable adhesive can be used. Adhesives such as adhesives, heat-sensitive adhesives (for example, hot melt type adhesives), and pressure-sensitive adhesives are preferable. A moisture-curable adhesive and a heat-sensitive adhesive are preferable in consideration of compatibility with the pressure-sensitive adhesive sheet of the present invention having a predetermined water vapor transmission rate, ease of handling, and the like. Further, a moisture-curable adhesive and a heat-sensitive adhesive are more preferable.
The heat-sensitive adhesive is preferable in that the molten liquid adhesive layer is cooled and solidified, and at the same time, the adhesive force rises to a saturated state.
The decorative material of the present embodiment has a moisture permeability of 0.75 g / ^m for 2.24 hours or more. Therefore, the moisture-curable adhesive can be exposed to an appropriate amount of moisture in the construction process, and the initial adhesion strength of the adhesive used for the adhesive layer can be easily increased. Further, the decorative material of the present embodiment has a moisture permeability of 45 g / ^m 2.24 h or less. For this reason, the moisture-curable adhesive does not come into contact with excessive moisture, and thus the deterioration of the adhesiveness due to the deterioration of the moisture-curable adhesive due to hydrolysis is suppressed, resulting in better construction suitability. At the same time, long-term adhesion can be easily obtained. Further, the moisture-curable adhesive is preferable in terms of ease of handling and the like.

Examples of the resin used for the adhesive constituting this adhesive layer include acrylic resin, polyurethane resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer resin, styrene-acrylic copolymer resin, and polyester resin. , Polyamide resin and the like, and these can be used alone or in combination of two or more. Further, a two-component curable polyurethane-based adhesive or a polyester-based adhesive using an isocyanate compound or the like as a curing agent can also be applied.

A moisture-curable adhesive, which is one of the adhesives preferably used in the present invention, and which has a urethane resin resin, contains a prepolymer having an isocyanate group at the molecular terminal as an essential component. The prepolymer is usually a polyisocyanate prepolymer having one or more isocyanate groups at both ends of the molecule, and is in the state of a solid thermoplastic resin at room temperature. As such a polyisocyanate prepolymer, for example, a solid polyester polyol which is crystalline at room temperature is used as a polyol component, and a polyisocyanate composed of 4,4-diphenylmethane diisocyanate, tolylene diisocyanate, or the like is used as a polyisocyanate component. Can be mentioned.

The thickness of the adhesive layer is not particularly limited, but is preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 50 μm or less, and further preferably 10 μm or more and 30 μm or less, for the purpose of obtaining excellent adhesiveness.

<Manufacturing method of decorative parts>
The decorative member can be manufactured through a step of laminating the pressure-sensitive adhesive sheet and the substrate of the present invention.
This step is a step of laminating the substrate and the pressure-sensitive adhesive sheet of the present invention, in which the surface of the substrate that requires decoration and the surface of the pressure-sensitive adhesive sheet on the pressure-sensitive adhesive layer side are opposed to each other and laminated. Examples of the method of laminating the substrate and the pressure-sensitive adhesive sheet include a laminating method in which the pressure-sensitive adhesive sheet is pressurized and laminated on a plate-shaped substrate with a pressure roller via an adhesive layer.

When a hot melt adhesive (heat sensitive adhesive) is used as the adhesive, the heating temperature is preferably 160 ° C or higher and 200 ° C or lower, and 100 for the reactive hot melt adhesive, although it depends on the type of resin constituting the adhesive. It is preferably ℃ or more and 130 ℃ or less. Further, in the case of vacuum forming processing, it is common to perform processing while heating, and the heating temperature is preferably 80 ° C. or higher and 130 ° C. or lower, more preferably 90 ° C. or higher and 120 ° C. or lower.
The decorative member obtained as described above can be arbitrarily cut, and the surface and the end of the wood can be arbitrarily decorated by grooving, chamfering, etc. using a cutting machine such as a router or a cutter.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

1. 1. Evaluation and measurement method 1-1. Absorbance Using an ultraviolet-visible near-infrared spectrophotometer (manufactured by Hitachi, Ltd., trade name: U-4000), on the adhesive layer obtained in each Example and Comparative Example in accordance with JIS K0115: 2004. The absorbance A ₂ of the pressure-sensitive adhesive sheet on which the surface protective layer was formed or the pressure-sensitive adhesive sheet on which the film layer and the surface protection layer were formed was measured at a wavelength of 300 nm or more and 360 nm or less. Further, the absorbance A0 of the pressure-sensitive adhesive layer (B layer) at a wavelength of 300 nm or more and 360 nm or less is measured by the same means, and the absorbance _A0 is subtracted from the _{absorbance A2} to obtain a surface protective layer, or a film layer and a surface protective layer ( The absorbance A1 of the layer _A ) was calculated.

1-2. Measurement of Moisture Permeability The adhesive sheets obtained in Examples and Comparative Examples were measured for moisture permeability in accordance with the moisture permeability test method (cup method) for moisture-proof packaging materials specified in JIS Z0208: 1976.

1-3. Evaluation of weather resistance Using the following ultra-accelerated weather resistance test equipment, the adhesive sheets obtained in Examples and Comparative Examples were irradiated with ultraviolet rays for 20 hours under the conditions of a black panel temperature of 63 ° C. and an illuminance of 100 mW / cm ² . After that, the cycle of dew condensation was repeated for 4 hours. After 800 hours, the appearance of the adhesive sheet was visually evaluated according to the following criteria.
<Ultra-accelerated weather resistance test equipment>
UV lamp (trade name: M04-L21WB / SUV, manufactured by Iwasaki Electric Co., Ltd.), lamp jacket (trade name: WJ50-SUV, manufactured by Iwasaki Electric Co., Ltd.) and illuminance meter (trade name: UVD-365PD, manufactured by Iwasaki Electric Co., Ltd.) Super accelerated weather resistance test device (trade name: Eye Super UV Tester SUV-W161 ", manufactured by Iwasaki Electric Co., Ltd.)
<Evaluation criteria for weather resistance>
A: No significant change was confirmed in appearance.
B: A slight crack was confirmed on the adhesive sheet.
C: Large cracks were confirmed in the pressure-sensitive adhesive sheet, and at least one of abnormalities such as peeling and floating was confirmed between the substrate and the pressure-sensitive adhesive sheet or in each layer constituting the pressure-sensitive adhesive sheet.

1-4. Evaluation of construction suitability The pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples and a substrate (material: polyvinyl chloride (PVC)) on a flat plate with a width of 25 mm are combined with a moisture-curable and hot-melt type urethane resin adhesive (molecule). A polyurethane prepolymer having an isocyanate group inside, "1308.20 (product name)", manufactured by TAKA) is melted at 120 ° C. and attached via an adhesive layer having a thickness of 50 μm, and then the adhesive is applied. The layer was solidified by cooling at room temperature 23 ° C. Next, the decorative sheet and the substrate to which the decorative sheet was attached were left to stand in an environment of 90 ° C. for 1 hour to prepare a sample. The sample was subjected to a Tencilon universal material tester (“Tencilon RTC-1250A (product name)”, manufactured by Orientec Co., Ltd.) under a temperature environment of 25 ° C., tensile speed: 10 mm / min, peeling direction. A peeling test was performed under the conditions of 90 ° and a distance between chucks of 30 mm, and the peeling strength was measured as the initial adhesive strength. The measurement results were evaluated according to the following criteria. If it is B evaluation or higher, the evaluation of construction suitability is passed.
<Evaluation criteria for construction suitability>
A: The peeling strength was 1.0 N / mm or more.
B: The peeling strength was 0.5 N / mm or more and less than 1.0 N / mm.
C: The peeling strength was less than 0.5 N / mm.

1-5. Evaluation of long-term adhesion After leaving the sample prepared in the above "1-4. Evaluation of construction suitability" in a moist heat environment of 70 ° C and 90% RH for 6 weeks, a Tencilon universal material test was conducted in a temperature environment of 25 ° C. Using a machine (“Tencilon RTC-1250A (product name)”, manufactured by Orientec Co., Ltd.), a peeling test was conducted under the conditions of a tensile speed of 50 mm / min and a peeling direction of 90 °, and the peeling strength was measured. The measurement results were evaluated according to the following criteria. If it is B evaluation or higher, the evaluation of long-term adhesion is passed.
<Evaluation criteria for long-term adhesion>
A: The peeling strength was 2.0 N / mm or more.
B: The peeling strength was 1.0 N / mm or more and less than 2.0 N / mm.
C: The peeling strength was less than 1.0 N / mm.

1-6. Processing aptitude When preparing a sample in the above "1-4. Evaluation of construction aptitude", visually confirm the floating of the decorative material at the bent part (bending angle: 1 mmR) when laminating. Evaluated according to the criteria of. If it is B evaluation or higher, the processing suitability is acceptable.
<Evaluation criteria for processing suitability>
A: No floating was confirmed.
B: Floating was hardly confirmed.
C: Floating was confirmed and peeling occurred.

[Example 1]
An adhesive sheet having an adhesive layer, a film layer, and a surface protective layer in this order was produced according to the following procedure.
The film layer comprises a resin composition containing 100 parts by mass of a polypropylene resin and 0.2 parts by mass of a triazine-based ultraviolet absorber 3 (trade name: Adecastab LA-F70, manufactured by ADEKA Co., Ltd., having a maximum absorption wavelength of around 355 nm). A film layer of a transparent polypropylene resin layer with a thickness of 60 μm (also referred to as “PO-A”) and a transparent polypropylene resin layer with a thickness of 100 μm (transparent resin layer, crystallinity: 70%, UV absorber: not contained). , Also referred to as “PO-1”), and a polypropylene resin layer having a two-layer structure was formed by coextrusion molding. The polypropylene resin layer having the above two layers was formed and then subjected to double-sided corona discharge treatment.
A composition composed of a polycarbonate-based urethane-acrylic copolymer and an acrylic polyol and hexamethylene diisocyanate are placed on a film layer of a transparent polypropylene resin layer containing an ultraviolet absorber 3 in the above-mentioned two-layer polypropylene resin layer. , 100: 5 mass ratio mixed composition was applied and then dried to form a primer layer having a thickness of 4 μm.
Next, on the primer layer, a hydroxyphenyltriazine-based ultraviolet absorber 1 (trade name: TINUVIN479, manufactured by BASF) was applied to 100 parts by mass of an ionizing radiation curable resin composition composed of a trifunctional urethane acrylate oligomer having a weight average molecular weight of 4000. , A composition containing 2 parts by mass of a maximum absorption wavelength of around 320 nm) and 3 parts by mass of a hindered amine light stabilizer (trade name: TINUVIN123, manufactured by BASF), and then irradiated with an electron beam to form an ionizing radiation curable resin. By curing the object, a surface protective layer having a thickness of 5 μm was formed.
Next, an acrylic resin (trade name: SK Dyne 2094, manufactured by Soken Kagaku Co., Ltd.) is placed on a transparent polypropylene resin layer (transparent resin layer) on the side opposite to the side on which the surface protective layer is formed. 100 parts by mass, 0.27 parts by mass of cross-linking agent (E-5XM, Soken Kagaku Co., Ltd.), and 0.4 mass of triazine-based ultraviolet absorber 2 (trade name: TINUVIN460, manufactured by BASF, near maximum absorption wavelength of 350 nm). After applying the acrylic pressure-sensitive adhesive composition containing the portion, the pressure-sensitive adhesive composition was dried to form a pressure-sensitive adhesive layer having a thickness of 25 μm, and the pressure-sensitive adhesive sheet of Example 1 was obtained.

[Examples 2 to 4]
An adhesive sheet was obtained in the same manner as in Example 1 except that the film layer and the transparent polypropylene resin layer (transparent resin layer) were changed to those shown in Table 1.

[Comparative Example 1]
The ultraviolet absorber 1 used in Example 1 was prepared and adhered in the same manner as in Example 1 except that the ultraviolet absorber 1 was a benzotriazole-based ultraviolet absorber (trade name: TINUVIN384-2, manufactured by BASF, with a maximum absorption wavelength of around 345 nm). I got a sheet.

[Comparative Example 2]
The ultraviolet absorber 3 used in Example 2 was prepared in the same manner as in Example 2 except that the triazine-based ultraviolet absorber (trade name: ADEKA STAB LA-46, manufactured by ADEKA Corporation, maximum absorption wavelength around 280 nm) was used. Obtained an adhesive sheet.

[Comparative Examples 3 to 4]
An adhesive sheet was obtained in the same manner as in Example 1 except that the film layer and the transparent polypropylene resin layer (transparent resin layer) were changed to those shown in Table 1.

The materials used for the film layer and the transparent polypropylene resin layer (transparent resin layer) in Table 1 and their thicknesses are as follows.
-PO-A: Polypropylene resin sheet (thickness: 60 μm)
-PO-1: Polypropylene resin sheet (propylene-ethylene random copolymer (ethylene content: 4.5% by mass or less), thickness: 100 μm, crystallinity: 70%)
-PO-2: Polypropylene resin sheet (propylene-ethylene random copolymer (ethylene content: 4.5% by mass or less), thickness: 80 μm, crystallinity: 50%)
-PO-3: Polypropylene resin sheet (propylene-ethylene random copolymer (ethylene content: 4.5% by mass or less), thickness: 80 μm, crystallinity: 40%)
-PO-4: Polypropylene resin sheet (propylene-ethylene random copolymer (ethylene content: 4.5% by mass or less), thickness: 120 μm, crystallinity: 70%)
-PVC1: Polyvinyl chloride resin sheet (thickness: 120 μm)
It is produced by extruding a resin composition obtained by adding 38 parts by mass of a phthalate ester-based plasticizer (Undecyl phthalate (DUP)) as a plasticizer to 100 parts by mass of a polyvinyl chloride resin.
-PVC2: Polyvinyl chloride resin sheet (thickness: 120 μm)
In the above PVC1, the plasticizer was a polyester-based plasticizer (adipic acid-based polyester), and the content thereof was 33 parts by mass with respect to 100 parts by mass of the polyvinyl chloride resin. It was done.

Since the pressure-sensitive adhesive layer is protected in the pressure-sensitive adhesive sheet of the present invention, the adhesion between the substrate, the film layer and the surface protection layer is guaranteed, and the weather resistance is excellent for a long period of time. Marking used for members exposed to sunlight, especially for outdoor and indoor applications, because it has high adhesion strength and excellent construction suitability, is less likely to peel off even after long-term use, and can have excellent long-term adhesion. It is suitably used as a film, a protective film for ultraviolet rays, and the like.
On the other hand, the sheets of Comparative Examples 1 and 2 did not have excellent weather resistance because the absorbance was out of the predetermined range, and the sheets of Comparative Examples 3 and 4 were excellent because the moisture permeability was out of the predetermined range. Construction suitability, long-term adhesion, and processing suitability could not be obtained.

100: Adhesive sheet 110: Surface protective layer 120: Adhesive layer 130: Film layer 200: Decorative member 210: Base 220: Adhesive layer

Claims (16)

It has an A layer including a surface protective layer containing an ultraviolet absorber 1 and a film layer containing an ultraviolet absorber 3, and a B layer including an adhesive layer containing an ultraviolet absorber 2.
The _average value of the absorbance A1 of the A layer at a wavelength of 300 nm or more and 360 nm or less, which was measured according to JIS K0115: 2004, was 0.8 or more and 1.4 or less , and was measured according to JIS K0115: 2004. The average value of the absorbance A ₂ of the A layer and the B layer at a wavelength of 300 nm or more and 360 nm or less is 1.2 or more and 1.8 or less .
The moisture permeability measured in accordance with the moisture permeability test method (cup method) of the moisture-proof packaging material specified in JIS Z0208: 1976 of the adhesive sheet is 0.75 g / m 2.24 h or ^more and 45 g / ^m 2.24 h or less. Is an adhesive sheet. The ultraviolet absorber 1 has a maximum absorption wavelength of 300 nm or more and 360 nm or less, and has an absorption band at the maximum absorption wavelength of the resin used for the surface protective layer and the maximum absorption wavelength of the resin used for the film layer. ,
The ultraviolet absorber 3 has a maximum absorption wavelength of 300 nm or more and 360 nm or less, and has an absorption band at the maximum absorption wavelength of the resin used for the film layer and the maximum absorption wavelength of the resin used for the pressure-sensitive adhesive layer.
The pressure-sensitive adhesive sheet according to claim 1, wherein the ultraviolet absorber 2 has a maximum absorption wavelength of 300 nm or more and 360 nm or less, and has an absorption band at the maximum absorption wavelength of the resin used for the pressure-sensitive adhesive layer. The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein at least one of the ultraviolet absorbers 1 to 3 is a triazine-based ultraviolet absorber. The absorbance of the A layer measured in accordance with JIS K0115: 2004 at a wavelength of 300 nm or more and 360 nm or less and at the maximum absorption wavelength of the resin used for the pressure-sensitive adhesive layer is 0.8 or more, and the above-mentioned The pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the A layer and the B layer have an absorbance of 1.2 or more. The pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein the ultraviolet absorber 1 is a triazine-based ultraviolet absorber, and the surface protective layer further contains a hindered amine-based light stabilizer. The pressure-sensitive adhesive sheet according to claim 5, wherein the hindered amine-based light stabilizer contains one or both of a non-reactive light stabilizer or a reactive light stabilizer with the resin used for the surface protective layer. .. The pressure-sensitive adhesive sheet according to any one of claims 1 to 6, wherein the surface protective layer contains a cured product of an ionizing radiation curable resin composition. The pressure-sensitive adhesive sheet according to any one of claims 1 to 7, wherein the film layer contains a polypropylene-based resin. The pressure-sensitive adhesive sheet according to any one of claims 1 to 8, which has a transparent resin layer on the surface of the film layer opposite to the surface protective layer. The pressure-sensitive adhesive sheet according to claim 9, wherein the transparent resin layer contains a copolymer of propylene and ethylene. One of claims 1 to 10, wherein the film layer contains a vinyl chloride resin and a plasticizer, and contains 15 parts by mass or more and 50 parts by mass or less of the plasticizer with respect to 100 parts by mass of the vinyl chloride resin. Adhesive sheet described in. A decorative member having the pressure-sensitive adhesive sheet and the substrate according to any one of claims 1 to 11 so that the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet and the substrate face each other. The decorative member according to claim 12 , which has an adhesive layer between the pressure-sensitive adhesive sheet and the substrate. The decorative member according to claim 13 , wherein the adhesive layer is made of a urethane-based adhesive. The decorative member according to claim 14 , wherein the urethane-based adhesive is a moisture-curable adhesive. The decorative member according to any one of claims 12 to 15 , wherein the substrate is a resin substrate or a metal substrate.

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