JP7378535B2 - Removable adhesive sheet for process use - Google Patents

Description

The present invention relates to a removable pressure-sensitive adhesive sheet for process use.

2. Description of the Related Art There is a wiring pattern board on which a wiring pattern for transmitting signals is arranged, which is incorporated into various electronic components such as touch panels, liquid crystal displays, organic EL displays, solar cell modules, and printed wiring boards. This wiring pattern board is often manufactured through a patterning method that includes an exposure process using ultraviolet irradiation, and in this method, an adherend consisting of a single-sided laminate with a wiring formation layer formed on the entire surface is used for temporary fixing. A method is known in which a wiring pattern is finally formed on one side of the base film by fixing it to a workbench using double-sided adhesive tape, then applying various treatments such as exposure to ultraviolet rays from the front side of the wiring formation layer. (Patent Document 1).
On the other hand, since the manufactured wiring pattern board needs to be peeled off and removed from the adhesive tape after processing is completed, a removable adhesive is usually used in the adhesive layer of the adhesive tape. As a removable adhesive, one containing an adhesive polymer whose main chain and/or side chain is a crystalline polymer is known (Patent Document 2).

Japanese Patent Application Publication No. 2014-154402 Japanese Patent Application Publication No. 9-251923

According to the conventional method disclosed in Patent Document 1, a single-sided laminate was disposed on only one side of the adhesive tape, resulting in poor processing efficiency (manufacturing efficiency of wiring pattern boards), and there is a need for improvement. Ta.

On the other hand, the adhesive disclosed in Patent Document 2 has sufficient adhesive strength during use, but the adhesive strength decreases when cooled to below room temperature (23°C), making it difficult to peel off the adherend after treatment. It makes it easier. It also has the advantage that it can be reused even after the adhesive force is once lowered and the adherend is peeled off after completion of treatment.
However, although the adhesive of Patent Document 2 can reliably adhere to the adherend during film processing or transportation under heating conditions (e.g. 60°C) (tackiness during heating is sufficient, releasability during heating is poor). Good), it is difficult to maintain the adherend at room temperature because the initial peeling force is small (initial tack is small. Initial peelability at room temperature is poor), and it is difficult to maintain the adherend at room temperature due to the small initial peeling force. When it is required to peel the adherend from the adhesive layer after processing, there is a tendency for adhesive residue to occur on the adherend when it is peeled off after the purpose of use has been completed and it is no longer needed (removal properties after heating). is defective). Such a problem becomes particularly serious when the adherend is a very thin laminate and is processed.

It is an object of the present invention to contribute to the efficient formation of various fine patterns on a substrate through a patterning method including an exposure step by irradiation with ultraviolet rays, and to form a single-sided laminate on which a pattern forming layer is formed on the entire surface. It can be reattached to adherends at room temperature, retains the adherend well, and remains in close contact with the adherend during processing or transportation under heated conditions (e.g., 60°C). Another object of the present invention is to provide a removable pressure-sensitive adhesive sheet for process use that can be easily peeled off from an adherend even after processing under high-temperature conditions (for example, 150° C. for 1 hour).

The present inventors have conducted extensive research in order to solve the above problems, and have completed the present invention. That is, according to the present invention, there is provided a pressure-sensitive adhesive sheet having pressure-sensitive adhesive layers having the following configuration on each of one surface and the other surface of a base film.

The adhesive layer of the present invention has an initial peel force of 0.05 (N/25 mm) or more at 23°C (room temperature), a peel force of 0.05 (N/25 mm) or more when heated at 60°C, and a peel strength of 150 It is characterized by having a peeling force (post-heating peeling force) at room temperature after heating at ℃ for 1 hour of 0.7 (N/25 mm) or less, and an ultraviolet shielding rate of 90% or more.

The adhesive sheet of the present invention preferably has a total light transmittance of 87% or more and a haze of 5% or less.

The adhesive layer of the present invention preferably has a thickness of 3 μm to 20 μm.

The adhesive composition constituting the adhesive layer of the present invention has at least a resin component (A) containing A1 and A2, a crosslinking agent (B), and an ultraviolet absorber (C) shown below, and the A It is preferable that the blending ratio (A1:A2) of A1 and A2 in the inside is 95:5 to 65:35 in terms of mass, and the blending amount of C is 5 to 40 parts by mass relative to 100 parts by mass of A. .

A1 (first acrylic resin) has a glass transition temperature (Tg1) and a mass average molecular weight (Mw1), and A2 (second acrylic resin) has a glass transition temperature (Tg2) and a mass average molecular weight (Mw2). )have.
The relationship between Tg1 and Tg2 is Tg1<Tg2 (Tg2 is higher than Tg1).
Both Mw1 and Mw2 are 100,000 or more.

In the adhesive composition constituting the adhesive layer of the present invention, the blending ratio (A1:A2) of A1 and A2 in A is preferably 90:10 to 80:20 in terms of mass.

In the adhesive composition constituting the adhesive layer of the present invention, Tg1 is -70 to -25°C, Tg2 is -15 to 30°C, and the difference between Tg2 and Tg1 (Tg2-Tg1) is 10°C or more. It is preferable.

In the adhesive composition constituting the adhesive layer of the present invention, the ratio of Mw2 to Mw1 (Mw2/Mw1) is preferably 0.5 to 2.

In the adhesive composition constituting the adhesive layer of the present invention, the compositions of A1 and A2 are not particularly limited. As an example, A2 may be formed of at least a copolymer of A11, A12, and A13 shown below. As an example, A1 may be formed of at least a copolymer of A12 and A13 shown below.

A11: ethyl methacrylate or methyl methacrylate,
A12: (meth)acrylate having a functional group capable of reacting with B and an alkyl group having 2 to 8 carbon atoms;
A13: Monomer having an ethylenically unsaturated double bond (excluding ethyl methacrylate and methyl methacrylate).

In the adhesive sheet of the present invention, when forming a fine pattern on a substrate through a patterning method including an exposure step by irradiation with ultraviolet rays, a pattern forming layer is formed on the entire surface of one side of the substrate via the adhesive layer, Two adherends consisting of two single-sided laminates each having a resist formed on the entire surface of the pattern forming layer are bonded together with their base surfaces facing each other, and then wiring is applied to one of the single-sided laminates on the resist. Ultraviolet rays are irradiated with the first mask corresponding to the pattern placed, and ultraviolet rays are irradiated with the second mask corresponding to the wiring pattern placed on the other single-sided laminate. It is used in the process of peeling off from each base material surface.

As a single-sided laminate, for example, a photosensitive film in which a photosensitive layer consisting of a laminate of a pattern forming layer and a photosensitive resin layer is provided on a substrate, a substrate in which a pattern forming layer is formed on the entire surface of one side, Examples include a laminate with a dry film resist corresponding to a photosensitive resin layer. That is, the mere "resist" as used in the present invention includes a dry film resist as well as a photosensitive resin layer of a photosensitive film.

The adhesive sheet of the present invention has an adhesive layer that exhibits predetermined performance on each of one side and the other side of the base film. Therefore, by using the adhesive sheet of the present invention, ultraviolet rays irradiated from one side through the adhesive sheet are prevented from being transmitted/irradiated to the back side. As a result, even if single-sided laminates are attached to both the front and back surfaces of one adhesive sheet and exposed to light, the exposure of one single-sided laminate will not affect the other single-sided laminate. For this reason, if the adhesive sheet of the present invention is used, single-sided laminates can be attached to both the front and back sides of one adhesive sheet and exposed to light (that is, two single-sided laminates can be exposed to light). This technology can double the processing efficiency compared to previous technology, which could only expose one single-sided laminate to one adhesive sheet.

In addition, since the adhesive layer exhibits the specified performance, it is possible to re-attach the adherend at room temperature to an adherend consisting of a single-sided laminate on which a pattern formation layer is formed on the entire surface, and it also maintains the adherend. It has good properties and adheres reliably to the adherend during processing and transportation under heated conditions (e.g. 60°C), and does not peel off from the adherend even after processing under high temperature conditions (e.g. 150°C for 1 hour). can be made easier.

That is, according to the present invention, it is possible to contribute to the efficient formation of various fine patterns on a substrate through a patterning method including an exposure step by irradiation with ultraviolet rays, and also to form a single-sided laminate on which a pattern forming layer is formed on the entire surface. It can be reattached at room temperature to adherends made of Thus, it is possible to provide a process-use removable pressure-sensitive adhesive sheet that can be easily peeled off from an adherend even after processing under high-temperature conditions (for example, 150° C. for 1 hour).

The adhesive sheet of the present invention has an adhesive layer on one side and the other side of the base film, and each adhesive layer is formed so as to exhibit the following performance with respect to the adherend. It is characterized by

First, the initial peeling force at 23° C. (initial peeling force at room temperature (X1)) is 0.05 (N/25 mm) or more. If X1 is less than 0.05 (N/25 mm), the adhesion to the adherend may become poor, which may lead to inconveniences such as reduced workability, and this is to prevent this. In this example, it is preferable that X1 is 0.15 (N/25 mm) or more. Note that the upper limit of X1 is, for example, about 1 (N/25 mm).

Second, the peeling force in a heated atmosphere of 60° C. (peeling force during heating (X2)) is 0.05 (N/25 mm) or more. If X2 is less than 0.05 (N/25 mm), the adhesion to the adherend will be poor during the heating process, which may lead to inconveniences such as lifting or peeling from the adherend, and this is to prevent this. . In this example, it is preferable that X2 is 0.07 (N/25 mm) or more. Note that the upper limit of X2 is, for example, about 1 (N/25 mm).

Thirdly, the peeling force at room temperature after heating at 150° C. (1 hour) (peeling force after heating (X3)) is 0.7 (N/25 mm) or less. If X3 exceeds 0.7 (N/25mm), it becomes difficult to peel off the adhesive from the adherend, which may cause curls or adhesive residue on the adherend, or cause cohesive failure. , in order to prevent this. In this example, it is preferable that X3 is 0.3 (N/25 mm) or less. Note that the lower limit of X3 is theoretically 0 (N/25 mm).

Fourthly, the ultraviolet shielding rate (X4) is 90% or more. The advantage of having a configuration capable of blocking 90% or more of ultraviolet rays will be explained in conjunction with the exposure process described later. Note that the upper limit of X4 is theoretically 100%.

Ultraviolet rays generally refer to near ultraviolet rays (wavelength 200 to 380 nm), far ultraviolet rays (wavelength 10 to 200 nm), and extreme ultraviolet rays (10 to 121 nm), but in the present invention, ultraviolet rays mainly refer to near ultraviolet rays (wavelength 200 to 380 nm). means. Examples of lamps that emit light in the near-ultraviolet wavelength range include high-pressure mercury lamps, metal halide lamps, high-efficiency metal halide lamps, and high-power metal halide lamps.
High-pressure mercury lamps efficiently emit ultraviolet rays of 254 nm, 303 nm, and 313 nm with a main wavelength of 365 nm, and metal halide lamps emit ultraviolet rays over a wide range from 200 nm to 450 nm.

High-efficiency metal halide lamps emit ultraviolet rays with 20% higher illuminance at 365 nm than the metal halide lamps described above, and high-power metal halide lamps emit ultraviolet rays with particularly high output between 400 and 450 nm.
In this example, in the case of radiation from a high-pressure mercury lamp, it is preferable that the blocking rate is 90% or more, especially for light on the shorter wavelength side than 380 nm, and in the case of radiation from a metal halide lamp, especially for light on the shorter wavelength side than 450 nm. It is preferable that the light shielding rate is 90% or more.

The composition of each adhesive layer that exhibits the above-mentioned performance (physical properties) is not particularly limited, but each adhesive layer can be composed of, for example, the adhesive composition shown below.

The adhesive composition according to one example contains a resin component (A), a crosslinking agent (B), and an ultraviolet absorber (C) as essential components.

As the resin component (A), for example, at least two (two or more) acrylic resins are used. The two or more types of acrylic resins include at least a component (A1) that maintains X1 (that is, maintains adhesion when bonded to the adherend), and a component (A1) that maintains X2 (that is, maintains adhesion when bonded to the adherend); It is desirable to include a component (A2) for suppressing an increase in X3 and improving re-peelability at room temperature while maintaining adhesion at room temperature.

In order to suppress the increase in X3 while maintaining X1 and X2, A1 and A2 should both have moderately high mass average molecular weights (Mw1, Mw2) (Mw1 and Mw2 are 100,000 or more), and A2 should be a glass of A1. A material having a glass transition temperature (Tg2) higher than the transition temperature (Tg1) is used (Tg1<Tg2).

As A1 (first acrylic resin), one having a mass average molecular weight (Mw1) of 100,000 or more and a glass transition temperature (Tg1) of -25° C. or less is used. If Mw1 is less than 100,000, the peeling force after heating tends to increase, which is not preferable. The reason why Tg1 is set to be −25° C. or less is based on the fact that adhesive strength begins to develop at around +30° C. (Tg + 30° C.) above the glass transition temperature (Tg) of the adhesive. It should be noted that if Mw1 is too high, the compatibility with A2 tends to deteriorate or the initial peeling force is insufficient at room temperature, and if Tg1 is too low, the peeling force during heating is likely to be insufficient. Therefore, for A1, in addition to satisfying the above conditions (Mw1 is 100,000 or more and Tg1 is -25°C or less), Mw1 is 1 million or less and/or Tg1 is -70°C or more. Something is desirable.

A1 is, for example, a (meth)acrylate (A12) having an alkyl group having 2 to 8 carbon atoms as well as a functional group that can react with the crosslinking agent (B) described later, and a monomer (A12) having an ethylenically unsaturated double bond. A13), etc.

A12 is a component for improving the cohesive force of the adhesive layer to be formed and preventing adhesive residue from being left on the adherend. Examples of the functional group include a hydroxyl group, a carboxyl group, an amino group, an acetoacetoxyethyl group, an epoxy group, and from the viewpoint of versatility, it is preferably at least one selected from a hydroxyl group and an amino group. Examples of A12 having such a functional group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and diethylene glycol mono(meth)acrylate as monomers having a hydroxyl group. ) acrylate, N-methylol acrylamide, allyl alcohol, p-hydroxystyrene, etc. Examples of monomers having a carboxyl group include β-carboxyethyl (meth)acrylate, (meth)acrylic acid, itaconic acid, crotonic acid, maleic acid, and maleic anhydride. Examples of monomers containing amino groups include aminomethyl (meth)acrylate, methylaminomethyl (meth)acrylate, methylaminoethyl (meth)acrylate, methylaminopropyl (meth)acrylate, and acrylamide. Examples of monomers containing an acetoacetoxyethyl group include acetoacetoxyethyl (meth)acrylate. Examples of monomers containing epoxy groups include glycidyl (meth)acrylate. Among them, by using at least one selected from 2-hydroxyethyl methacrylate (HEMA) and 2-hydroxyethyl acrylate (HEA), which are monomers having a hydroxyl group, the cohesive force of the adhesive layer can be further improved, and the adhesive layer can be more easily bonded to the adherend. It is possible to prevent adhesive residue from forming on the surface.

A13 is a component for adjusting the peeling force from the adherend and making it easier to adjust the Tg of the entire adhesive layer to an appropriate range. A13 is a (meth)acrylate having an alkyl group having 2 to 8 carbon atoms (excluding ethyl methacrylate and methyl methacrylate), such as ethyl acrylate (EA), methyl acrylate, butyl (meth)acrylate (BA, BMA), 2-ethylhexyl (meth)acrylate (2-EHA, 2-EHMA), propyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, vinyl acetate (VA), vinyl propionate, vinyl ether, Examples include styrene and (meth)acrylonitrile. Among them, by using at least one selected from ethyl acrylate, butyl (meth)acrylate, acrylonitrile (AN), methyl acrylate, 2-ethylhexyl (meth)acrylate, and vinyl acetate, the peeling force from the adherend can be further adjusted. In addition to making it easier to adjust the Tg of the entire adhesive layer to an appropriate range.

A preferable mass ratio of A12 and A13 that can constitute A1 is as follows. A12 has a lower limit of 0.5% by mass or more, further 1% by mass or more, an upper limit of 10% by mass or less, further 5% by mass or less, and A13 has a lower limit of 30% by mass or more, further 50% by mass. % or more, and the upper limit is preferably 99.5% by mass or less, and more preferably 70% by mass or less.

As A2 (second acrylic resin), one having a mass average molecular weight (Mw2) of 100,000 or more and a glass transition temperature (Tg2) higher than Tg1 is used. If Mw2 is less than 100,000, the peeling force after heating tends to increase. On the other hand, if Tg2 is less than Tg1 (Tg2≦Tg1), the peeling force during heating tends to be insufficient, which is not preferable. Note that if Mw2 is too high, the compatibility with A1 tends to deteriorate and the initial peeling force at room temperature is insufficient, and if Tg2 is too high, the peeling force at room temperature after heating tends to increase. Therefore, as A2, in addition to satisfying the above conditions (Mw2 is 100,000 or more and Tg2 is higher than Tg1 (Tg2>Tg1)), Mw2 is 1 million or less and/or Tg2 is 30 It is desirable that the temperature is below ℃.

A2 can be composed of, for example, a copolymer of A12 and A13 described above and A11 (ethyl methacrylate or methyl methacrylate).
A11 is a component that does not reduce the thickness of the adhesive layer and prevents adhesive residue from forming on the adherend even after being attached to the adherend and heated at high temperature.

A preferable mass ratio of A11, A12, and A13 that can constitute A2 is as follows. A11 has a lower limit of 20% by mass or more, preferably 30% by mass or more, more preferably 50% by mass or more, and an upper limit of 80% by mass or less, preferably 70% by mass or less, more preferably 65% by mass, and A12 has a lower limit of 0.5% by mass or more, preferably 1% by mass or more, and an upper limit of 10% by mass or less, preferably 5% by mass or less, and A13 has a lower limit of 10% by mass or more, preferably 25% by mass. Above, it is more preferably 30% by mass or more, and the upper limit is preferably 79.5% by mass or less, preferably 69% by mass or less, and still more preferably 49% by mass or less.

The blending ratio of A1 and A2 (A1:A2) is preferably in the range of 95:5 to 65:35 (preferably 90:10 to 80:20) in terms of mass. When the blending ratio of A2 is less than 95:5, the peeling force during heating is likely to be insufficient and the peeling force after heating tends to increase.On the other hand, when the blending ratio of A2 exceeds 65:35, the initial peeling force is and the compatibility tends to deteriorate.

From the viewpoint of increasing the peeling force during heating, A1 and A2 are preferably selected so that the difference between Tg2 and Tg1 (Tg2-Tg1) is 10° C. or more. Additionally, or in addition to this, it is preferable to select A1 and A2 so that the ratio of Mw2 and Mw1 (Mw2/Mw1) is 0.5 to 2. By setting Mw2/Mw1 to 0.5 or more, it is easier to suppress the increase in peel force after heating, and by setting Mw2/Mw1 to 2 or less, compatibility can be further improved, so that the desired It is possible to easily obtain a high-performance adhesive layer.

The crosslinking agent (B) means a substance that can crosslink A1 and/or A2 described above to form a crosslinked polymer. By forming a crosslinked polymer, it becomes easy to exhibit sufficient adhesive strength during film processing and excellent releasability after cooling.
As B, isocyanate crosslinking agents, metal chelate crosslinking agents, epoxy crosslinking agents, and the like are generally known, and in the present invention, isocyanate crosslinking agents can be preferably used.

As the isocyanate crosslinking agent, conventionally known isocyanate crosslinking agents such as polyvalent isocyanate compounds, oligomers and prepolymers thereof, etc. can be suitably used. Examples of the polyvalent isocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, and diphenylmethane. -2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, lysine isocyanate, etc. . Among them, alicyclic diisocyanates such as isophorone diisocyanate can be preferably used. This crosslinking agent is preferable in that it can provide excellent removability and heat resistance. Note that the "crosslinking agent" may be used alone or in combination of two or more types.

The blending ratio of B is not particularly limited as it varies depending on the type of crosslinking agent, the number of functional groups, etc.; The amount is preferably in the range of 1.5 to 6 parts by mass, and more preferably 1.5 to 6 parts by mass. By setting the blending ratio of B to 1 part by mass or more, the increase in peeling force after heating can be suppressed and it can be easily peeled off without any residue, and by setting the blending ratio to 8 parts by mass or less, initial peeling at room temperature can be improved. It is possible to suppress the decrease in power.

The ultraviolet absorber (C) should be one that can block at least 90% (preferably 95% or more) of the light emitted from a high-pressure mercury lamp or metal halide lamp by the entire adhesive layer when it is included in the adhesive layer. There are no particular limitations, and examples include benzotriazole-based ultraviolet absorbers and triazine-based ultraviolet absorbers. These may be used alone or in combination of two or more.

The blending ratio of C is not particularly limited as it varies depending on the type of ultraviolet absorber and the thickness of the adhesive layer, but it is 5 to 40 parts by mass per 100 parts by mass of A (for example, the sum of A1 and A2). The amount is preferably in the range of 10 to 20 parts by mass, and more preferably 10 to 20 parts by mass. By setting the blending ratio of C to 5 parts by mass or more, it is possible to ensure a UV shielding rate of 90% or more in the entire adhesive layer, and by setting the blending ratio to 40 parts by mass or less, excessive content can be prevented. Precipitation of the absorbent can be prevented, and the peeling force can be easily adjusted as a whole.

The adhesive composition of this example can be prepared by adding (A), (B), and (C) described above, and, if necessary, various conventionally used additives in any order, and dissolving or dispersing them. Obtainable. The above-mentioned raw materials can be mixed using a mixer or kneader such as a dissolver, a planetary mixer, or a butterfly mixer.

Examples of various additives include crosslinking accelerators, antioxidants, stabilizers, viscosity modifiers, tackifying resins, and organic or inorganic fillers. Examples of the crosslinking accelerator include those based on triethylamine, cobalt naphthenate, tin, zinc, titanium, and zirconium. When the crosslinking agent is an isocyanate-based crosslinking agent, zinc-based, titanium-based, and zirconium-based promoters such as alkoxides, acylates, and complexes, stannous chloride, tetra-n-butyltin, stannic chloride, and trimethyltin hydroxide are used. It is preferred to use tin-based accelerators such as , dimethyltin dichloride, di-n-butyltin dilaurate, and the like. Furthermore, when using an epoxy resin as a crosslinking agent, a phenol containing three tertiary amines in one molecule, known as TMP-30, is particularly effective. Furthermore, examples of the antioxidant include phenolic antioxidants. By incorporating an appropriate amount of an antioxidant into the adhesive composition of this example, it is possible to further suppress an increase in peel strength after heating when used as an adhesive layer.

The adhesive layer of this example can be obtained by applying the above-mentioned adhesive composition to one side and the other side of the base film, and drying as necessary.

The base film used in the pressure-sensitive adhesive sheet of the present invention is not particularly limited, but preferably has heat resistance, such as polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, as well as polyimide resins and polycarbonate. Films made of resins, polystyrene resins, polyamide resins, polyetherimide resins, polyetherketone resins, polyphenylene sulfide resins, polyacrylate resins, polyester ether resins, polyamideimide resins, polymethyl methacrylate resins, fluorine resins, etc., are economical. Polyethylene terephthalate is a particularly preferred base material in terms of properties and performance. The base film may be transparent or opaque, may be colored, or may be made of a material that blocks ultraviolet rays. However, materials that reflect ultraviolet rays are not so preferred because they may reduce the accuracy of pattern formation by exposure to ultraviolet rays. Further, when a transparent material is used, it is preferable because both sides can be simultaneously confirmed during precise appearance defect confirmation using a camera or the like in the exposure process.

The thickness of the base film may be the thickness that has been conventionally used as a base film, for example, about 10 to 125 μm, as long as it can protect the adherend and support it with the necessary strength. A material with a thickness of .

The surface of the base film can be subjected to surface treatment if desired. Examples of surface treatments at this time include (1) discharge treatment such as corona discharge treatment and glow discharge treatment, (2) plasma treatment, (3) flame treatment, (4) ozone treatment, and (5) ultraviolet treatment and electron beam treatment. , ionizing active ray treatment such as radiation treatment, (6) surface roughening treatment such as sand mat treatment and hairline treatment, (7) chemical treatment, and (8) anchor layer formation. As the anchor layer, polyurethane resin, polyester resin, acrylic resin, polyester polyurethane resin, etc. are used. The thickness of this anchor layer typically ranges from 0.01 to 1.5 μm.

The thickness of each adhesive layer is not particularly limited as long as it has predetermined peeling performance (X1 to X3) and shielding performance (X4), and is generally about 2 to 50 μm, preferably about 3 to 20 μm. If the thickness is thinner than this, X1 will be small and it will be difficult for X2 to satisfy 0.05 (N/25mm) or more, resulting in lifting or peeling of the adherend during the process, or lowering X4, which is necessary. If the light shielding rate is not satisfied, ultraviolet rays may pass through the back surface, reducing exposure accuracy. Moreover, when this range is exceeded, X1 becomes high and X3 also becomes large, which may impede re-peelability.

In the pressure-sensitive adhesive sheet of the present invention, it is desirable that the total light transmittance of the entire sheet (excluding the separator described below; the same applies hereinafter) is adjusted to 87% or more, and the haze is adjusted to 5% or less. By setting it in such a range, transparency is good as an adhesive sheet, and both sides can be checked at the same time when checking appearance defects precisely using a camera or the like, which is preferable.

In order to facilitate handling of the adhesive sheet of the present invention, a removable separator may be attached to each surface of each adhesive layer until it is attached to an adherend. Any known separator can be used, and its thickness is preferably about 15 to 200 μm, for example.

The adhesive sheet of the present invention can be used, for example, to form a fine pattern on a base material through a patterning method including an exposure step (described later) by irradiating ultraviolet rays (manufacturing a fine pattern substrate in which a fine pattern is arranged on a base material). It can be used for a wide range of purposes.
Examples of the fine pattern include a decorative pattern of a decorative film, a wiring pattern for transmitting signals, and the like. A wiring pattern board having a wiring pattern arranged on a base material is used by being incorporated into various electronic components such as a touch panel, a liquid crystal display, an organic EL display, a solar cell module, and a printed wiring board, for example. Decorative pattern substrates with decorative patterns arranged on a base material are used, for example, in electronic devices, interiors and exteriors of vehicles, and the like.

For example, the adherend that is the basis of the micropatterned substrate includes a pattern formation layer (a layer that becomes the basis of the micropattern, such as a wiring pattern formation layer or a decorative pattern formation layer) and a photosensitive resin layer on the substrate. Examples include a photosensitive film provided with a photosensitive layer consisting of a laminate, and a laminate of a base material with a pattern forming layer formed on the entire surface of one side and a dry film resist corresponding to the photosensitive resin layer. In this example, a pattern forming layer is provided on the base material, and a photosensitive resin layer is provided on the pattern forming layer.

As the base material used for the adherend, a polymer film or plate-like material having heat resistance and solvent resistance can be preferably used. The present invention works effectively when the base material used for the adherend has high ultraviolet transmittance (low ultraviolet shielding performance; for example, the ultraviolet shielding rate at 380 nm is 20% or less). Examples of the polymer film include polyethylene terephthalate film, polyethylene film, polypropylene film, and polycarbonate film. The thickness of the base material can be, for example, 5 μm to 300 μm.

The pattern forming layer is a layer that becomes the basis of a fine pattern. The wiring pattern forming layer, which is an example of the pattern forming layer, is a layer that becomes the base of the wiring pattern, and its material is not particularly limited, and examples thereof include tin oxide, indium oxide, antimony oxide, zinc oxide, cadmium oxide, ITO, etc. The transparent conductive layer may be made of a metal oxide, silver nanowire, carbon nanotube, conductive polymer, or the like. The wiring forming layer can be formed entirely on the base film by, for example, a vacuum evaporation method, a sputtering method, an ion plating method, a CVD method, a roll coater method, or the like. The thickness of the wiring formation layer can be, for example, 5 nm to 5000 nm.
The decorative pattern forming layer, which is another example of the pattern forming layer, is a layer that forms the base of a decorative pattern, and its material is, for example, a metal vapor deposition layer such as aluminum, titanium, or nickel.

As the photosensitive resin layer, either a negative type or a positive type can be used. The photosensitive resin layer can be formed using, for example, a photosensitive resin composition containing a binder resin, a photopolymerizable compound having an ethylenically unsaturated bond, and a photopolymerization initiator. Examples of the binder resin include acrylic resin, styrene resin, epoxy resin, amide resin, amide epoxy resin, alkyd resin, phenol resin, ester resin, urethane resin, and epoxy acrylate resin obtained by reaction of epoxy resin and (meth)acrylic acid. Examples include acid-modified epoxy acrylate resins obtained by reacting epoxy acrylate resins and acid anhydrides. These may be used alone or in combination of two or more.

Examples of photopolymerizable compounds having ethylenically unsaturated bonds include compounds obtained by reacting polyhydric alcohols with α,β-unsaturated carboxylic acids, and compounds obtained by reacting glycidyl group-containing compounds with α,β-unsaturated carboxylic acids. Examples thereof include compounds obtained by oxidation, urethane monomers such as (meth)acrylate compounds having urethane bonds, phthalic acid compounds, and (meth)acrylic acid alkyl esters. These may be used alone or in combination of two or more.

Examples of photopolymerization initiators include aromatic ketones, benzoin ether compounds, benzoin compounds, oxime ester compounds, benzyl derivatives, 2,4,5-triarylimidazole dimers, acridine derivatives, N-phenylglycine, N-phenyl Examples include radical polymerization initiators such as glycine derivatives, coumarin compounds, and oxazole compounds. These may be used alone or in combination of two or more.

The photosensitive resin layer may further contain various additives as necessary. Examples of additives include plasticizers, fillers, antifoaming agents, flame retardants, stabilizers, adhesion agents, leveling agents, peel accelerators, antioxidants, fragrances, imaging agents, thermal crosslinking agents, etc. I can do it. These may be contained alone or in combination of two or more.

The photosensitive resin layer can be formed, for example, by applying a solution of a photosensitive resin composition dissolved in a solvent onto a pattern forming layer formed on a base material, and then drying the solution. The thickness of the photosensitive resin layer after drying can be, for example, 1 μm to 200 μm.

In addition, in order to facilitate handling of the photosensitive film as an adherend, it is preferable to provide a separator on the photosensitive resin layer. The separator can be constructed using the same material as the base film.

Examples of uses of the pressure-sensitive adhesive sheet of the present invention are as follows. This example includes a preparation process, a lamination process, an exposure process, a development process, an etching process, and a hot press process in this order.

In the preparation step, two of the above-mentioned photosensitive films that will become the basis of the fine pattern substrate and one adhesive sheet of the present invention are prepared.

In the lamination process, the first photosensitive film is placed so that the base material of one photosensitive film (hereinafter abbreviated as "first photosensitive film") faces one adhesive layer (hereinafter abbreviated as "first adhesive layer") of the adhesive sheet. The base material of the other photosensitive film (hereinafter abbreviated as "second photosensitive film") is placed on the surface (for example, the top surface) of the first adhesive layer, and the base material of the other photosensitive film (hereinafter referred to as "second adhesive layer") is A second photosensitive film is placed on the surface (for example, the bottom surface) of the second adhesive layer so as to face the second adhesive layer, and the first photosensitive film/adhesive sheet/second photosensitive film are heated at a temperature of, for example, 60 to 120°C. After adhesion, a laminate is obtained by pressure bonding (thermal lamination).
In this example, instead of a photosensitive film, a base material with a pattern forming layer formed on the entire surface of one side and a dry film resist corresponding to the photosensitive resin layer are prepared. Substrate)/(first adhesive layer/base film/second adhesive layer)/(substrate/pattern forming layer)/dry film resist in the stated order and press-bonded (thermal lamination) while heating. A laminate may be formed after deposition.

In the exposure process, light (hereinafter simply referred to as "ultraviolet rays") is irradiated from a high-pressure mercury lamp, metal halide lamp, etc. to a predetermined portion of the photosensitive resin layer of the first photosensitive film placed on the upper surface of the laminate after deposition. At the same time, a predetermined portion of the photosensitive resin layer of the second photosensitive film disposed on the lower surface of the laminate is irradiated with ultraviolet rays. That is, after deposition, the laminate is exposed to light from both its upper and lower surfaces. The exposure timing may be simultaneous exposure of the upper and lower surfaces, or exposure may be performed on one side at a time.

Specifically, for example, after adhering, the laminate is irradiated with ultraviolet rays while the first mask is placed in front of (above) the photosensitive resin layer of the first photosensitive film, and the second photosensitive film is Ultraviolet rays can be irradiated with the second mask placed in front of (below) the photosensitive resin layer.

More specifically, first, the first mask is positioned and fixed on the photosensitive resin layer of the first photosensitive film placed on the upper side of the laminate after being applied, and the first mask is placed on the underside of the laminate after being applied. A second mask is positioned and fixed on the photosensitive resin layer of the second photosensitive film to be placed. Both the first mask and the second mask have a formation pattern of a fine pattern corresponding to the overall shape of the fine pattern in a plan view. When the photosensitive resin layer is a negative type, the formation pattern of the fine pattern is a window portion (transparent portion) formed in the first mask and the second mask. In addition, when a positive type is used as the photosensitive resin layer, the formation pattern of the fine pattern becomes a mask part other than the window part (transparent part) formed in the 1st mask and the 2nd mask. Next, ultraviolet rays are irradiated from the front (upper) side of the first mask and the front (lower) side of the second mask. Ultraviolet rays can be irradiated using, for example, an ultraviolet irradiation lamp, a mercury lamp, a high-pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, etc. In this example, a high-pressure mercury lamp or a metal halide lamp is particularly used. The exposure intensity and exposure time of ultraviolet rays can be appropriately set depending on the photosensitive characteristics of the photosensitive resin layer.

In this example, the photosensitive resin layer is exposed in a pattern corresponding to the planar shape of each fine pattern by irradiating ultraviolet rays imagewise through the first mask and the second mask. As a result, the portion of the photosensitive resin layer exposed to ultraviolet rays is cured in a manner corresponding to the planar shape of the fine pattern, while the other portion remains uncured.

In this example, since the first adhesive layer has an ultraviolet shielding rate (X4) of 90% or more, the transmission/irradiation of ultraviolet rays to the back side (second photosensitive film) is suppressed, and as a result, the The exposure to light on the photosensitive resin layer of the first photosensitive film does not affect the photosensitive resin layer of the second photosensitive film. Similarly to the first adhesive layer, the second adhesive layer also suppresses the transmission/irradiation of ultraviolet rays to its back side (first photosensitive film), and as a result, the exposure to the photosensitive resin layer of the second photosensitive film is suppressed. This does not affect the photosensitive resin layer of the first photosensitive film. These are the advantages of having each of the first adhesive layer and the second adhesive layer capable of blocking 90% or more of ultraviolet rays.

In the developing step, parts of the photosensitive layers (photosensitive resin layers) of the first photosensitive film and the second photosensitive film are developed. Specifically, after exposure and adhesion, the uncured parts (unnecessary parts) of the photosensitive resin layer of the laminate are removed, and the cured parts (necessary parts) of the photosensitive resin layer corresponding to the cured parts are patterned. do. For example, the uncured portion of the photosensitive resin layer is removed by wet development using a developer depending on the chemical properties of the photosensitive resin layer. As a result, a cured portion consisting of a cured product of the photosensitive resin layer cured in the exposure step is left. Note that when the uncured portion of the photosensitive resin layer is removed, a part of the pattern forming layer corresponding to the uncured portion (corresponding to an unnecessary portion described below) is exposed.

Wet development is performed using, for example, an alkaline aqueous solution, an aqueous developer, an organic solvent developer, or the like by a known method such as spraying, oscillating immersion, brushing, or scraping.

As the developer, an alkaline aqueous solution is preferred because it is safe, stable, and has good operability. Examples of the alkaline aqueous solution include 0.1 to 5 mass% sodium carbonate aqueous solution, 0.1 to 5 mass% potassium carbonate aqueous solution, 0.1 to 5 mass% sodium hydroxide aqueous solution, and 0.1 to 5 mass% sodium carbonate aqueous solution. An aqueous sodium tetraborate solution is preferred. Further, the pH of the alkaline aqueous solution used for development is preferably in the range of 9 to 11. The temperature of the alkaline aqueous solution is adjusted according to the developability of the photosensitive resin layer. Further, the alkaline aqueous solution may contain a surfactant, an antifoaming agent, a small amount of an organic solvent for accelerating development, and the like.

Further, an aqueous developer consisting of water or an aqueous alkaline solution and one or more organic solvents can be used. Here, in addition to the above-mentioned bases, examples of bases contained in the alkaline aqueous solution include borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1 , 3-propanediol, 1,3-diamino-2-propanol, and morpholine.

Examples of organic solvents include methyl ethyl ketone, acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether. can be mentioned.

The content of the organic solvent in the aqueous developer is preferably 2 to 90% by mass. The temperature of the aqueous developer can be adjusted depending on the developability. The pH of the aqueous developer is preferably as low as possible within a range that allows sufficient development of the photosensitive resin layer. The pH of the aqueous developer is preferably 8 to 12, more preferably 9 to 10. The aqueous developer may contain a small amount of a surfactant, an antifoaming agent, and the like.

Examples of organic solvent-based developers include 1,1,1-trichloroethane, N-methylpyrrolidone, N,N-dimethylformamide, cyclohexanone, methylisobutylketone, and γ-butyrolactone. These organic solvent-based developers preferably contain water in a range of 1 to 20% by mass to prevent ignition.

Examples of development methods include a dip method, a battle method, a spray method (high-pressure spray method, etc.), brushing, and slapping.

In the etching process, the exposed parts (unnecessary parts) of the pattern forming layer corresponding to the removed uncured parts of the photosensitive resin layer are removed, and the uncured parts of the pattern forming layer corresponding to the remaining cured parts of the photosensitive resin layer are removed. Pattern the exposed areas (necessary areas). For example, the pattern is etched at 40°C to 60°C for 3 to 10 minutes using an etching solution depending on the chemical properties of the pattern forming layer (for example, a mixed liquid of copper sulfate and hydrogen peroxide). Remove the exposed portion of the forming layer. Thereafter, the cured portion of the photosensitive resin layer remaining on the non-exposed portion of the pattern forming layer is removed using, for example, a strong alkaline solution and washed with water at room temperature.

In the heat pressing process, a coverlay film is placed from the top and bottom of the adherend after the cured portion of the photosensitive resin layer has been removed, and the coverlay film is bonded by heat pressing at, for example, 150°C for 1 hour, and then heated at room temperature. After cooling to (23° C.), the adhesive sheet is peeled off and removed to obtain two intermediate materials suitable for manufacturing a fine pattern substrate. After the next step, the obtained intermediate material is used to finally obtain a finely patterned substrate.

The present invention will be specifically described below based on experimental examples (including examples and comparative examples), but the present invention is not limited to these examples.

1. Production of adhesive sheet [Experimental Examples 1 to 12]
On one side of the base film (50 μm, polyethylene terephthalate), apply adhesive layer forming coating liquids a to s prepared by uniformly mixing and dissolving the following components at the solid content ratio (in terms of mass) listed in Table 2. Each was applied using a Baker type applicator so that the dry film thickness was approximately 7 μm. In addition, the total solid content in each coating liquid was adjusted to 30% by mass. Thereafter, an adhesive layer was formed by drying at 160° C. for 1 minute, and then a 25 μm thick PET film (separator), one surface of which had been subjected to silicone release treatment, was bonded to the surface of this adhesive layer. Next, an adhesive layer was formed on the other side of the base film using the same adhesive layer forming coating solution as above, and a separator was attached in the same manner. Thereafter, the adhesive sheets were cured at room temperature to obtain adhesive sheets of each example in which adhesive layers were formed on each of one side and the other side of the base film.

《Components of adhesive layer forming coating liquids a to s》
- First acrylic resin (A1, A1'): type/composition listed in Table 1 and solid content ratio listed in Table 2 - Second acrylic resin (A2, A2'): type/composition listed in Table 1 Solid content ratio/Crosslinking agent (B) listed in Table 2: Solid content ratio/Crosslinking agent (B) listed in Table 2: Solid content ratio listed in Table 2 (Takenate D-140N, alicyclic diisocyanate, Mitsui Chemicals, Inc. made)
・Ultraviolet absorber (C): Solid content ratio listed in Table 2 (benzotriazole absorbent)
・Antioxidant: Solid content ratio listed in Table 2 (phenolic antioxidant)
・Solvent (mixed solvent of toluene and methyl isobutyl ketone): Appropriate amount

2. Evaluation Regarding the adhesive sheets obtained in each example, the physical properties of the adhesive layer were measured and evaluated by the following method.

(2-1) Initial peeling force X1 (N/25mm)
Under conditions of 23° C. and 65% RH, a 2 cm x 10 cm adhesive sheet obtained in the experimental example was prepared, and one separator was peeled off and the exposed adhesive layer was used as an adherend and a PET film (thickness 50 μm, Lumirror T-60 (manufactured by Toray Industries, Inc.) was bonded by pressing a 2 kg rubber roller back and forth at a speed of 300 mm/min, and left for 20 minutes under the same conditions (23°C, 65% RH) for testing. Got a piece. Next, the peeling force (initial peeling force ), and was evaluated using the following criteria. The results are shown in Table 3.

"◎": 0.15 (N/25 mm) or more (excellent bonding properties).
"○": 0.05 (N/25 mm) or more and less than 0.15 (N/25 mm) (good bonding properties).
"x": less than 0.05 (N/25 mm) (poor bonding properties).

(2-2) Peeling force during heating X2 (N/25mm)
After preparing a test piece in the same manner as in (2-1) above, with the adhesive sheet portion of the test piece in contact with a 60°C hot plate, apply the peel force ( The peeling force during heating (X2) was measured (Table 2) and evaluated based on the following criteria. The results are shown in Table 3.

"◎": 0.07N/25mm) or more (excellent adhesion).
"○": 0.05 (N/25 mm) or more, less than 0.07 (N/25 mm) (good adhesion).
"x": less than 0.05 (N/25 mm) (poor adhesion).

(2-3) Peeling force after heating X3 (N/25mm)
After preparing a test piece in the same manner as in (2-1) above, the test piece was heated in an atmosphere of 150°C for 1 hour, cooled at 23°C and 65% RH, and then heated in the same manner as in (2-1) above. The peeling force (post-heating peeling force X3) was measured in the same manner as in 1) (Table 2), and evaluated based on the following criteria. The results are shown in Table 3.

"◎": 0.3 (N/25 mm) or less (excellent releasability).
"○": more than 0.3 (N/25 mm) and less than 0.7 (N/25 mm) (good removability).
"x": Exceeded by 0.7 (N/25 mm) (poor peelability).

(2-4) Compatibility of acrylic resin (A1) and acrylic resin (A2) in coating liquid First acrylic resin (A1) and second acrylic resin (A2) in adhesive layer forming coating liquid The conditions of the coating liquid and the surface of the adhesive layer were visually evaluated to determine whether the compatibility with A2) was good. The results are shown in Table 3.

"◎": The coating liquid is transparent without clouding, and there is no whitening on the adhesive layer surface (excellent compatibility)
"○": The coating liquid becomes slightly cloudy, but there is no whitening on the adhesive layer surface (good compatibility)
"×": The coating liquid becomes cloudy and there is whitening on the surface of the adhesive layer (poor compatibility)

(2-5) Ultraviolet shielding rate X4 (%)
With both separators of the adhesive sheet obtained in the experimental example peeled off, the ultraviolet shielding rate of the entire sheet was measured using an ultraviolet-visible near-infrared spectrophotometer (V-660, manufactured by JASCO Corporation), and it was measured according to the following criteria. It was evaluated by The results are shown in Table 3.

"◎": 380 nm light shielding rate is 95% or more (excellent shielding rate)
"○": 380 nm light shielding rate is 90% or more and less than 95% (good shielding rate)
"×": The shielding rate of 380 nm light is less than 90% (the shielding rate is not very good)

(2-6) Transparency To evaluate transparency, total light transmittance (%) and haze (%) were measured and evaluated.

With both separators of the adhesive sheet obtained in the experimental example peeled off, the total light transmittance (based on JIS 27361) and haze (based on JIS 27136) of the entire sheet were measured using a haze meter (NDH4000, manufactured by Nippon Denshoku Co., Ltd.). It was measured and evaluated based on the following criteria. The results are shown in Table 3.

(Total light transmittance)
"◎": Total light transmittance of 87% or more (excellent transparency)
"○": Total light transmittance is 80% or more and less than 87% (good transparency)
"×": Total light transmittance is less than 80% (transparency is not very good)

(Haze)
"◎": Haze is 3% or less (excellent transparency)
"○": Haze is more than 3% and less than 5% (good transparency)
"×": Haze exceeds 5% (transparency is not very good)

3. Consideration
Experimental Examples 2 to 4, 4a, 4b, 5, 5b to 5d, 6, 7, 9, and 10 have Mw (Mw1, Mw2) of 100,000 or more as A1 and A2 (A1a, A2a, A2b, A2c) was used, and those used as A2 (A2a, A2b, A2c) had a glass transition temperature Tg2 higher than the glass transition temperature Tg1 of A1, and the blending ratio of A1 and A2 (A1 :A2) satisfies 95:5 to 65:35 in terms of mass, and furthermore, the content of C to 100 parts by mass of A (total of A1 and A2) is 5 to 40 parts by mass. It was a pressure-sensitive adhesive sheet having on one side and the other side (that is, both sides) of the base film (Tables 1 and 2). These adhesive sheets had sufficient initial tack and good adhesion properties (X1 was ○ or ◎), and had sufficient adhesion during heating (X2 was ○ or ◎). . Further, there was no glue remaining after the heat treatment, and the releasability was good (X3: ○ or ◎), and the UV shielding rate was sufficient (X4: ○ or ◎). Furthermore, the compatibility of A1 and A2 in the coating liquid was also good (compatibility: ○ or ◎) (Table 3).

In particular, in Experimental Examples 3, 4, 5, and 6, the blending ratio of A1 and A2 (A1:A2) satisfied 90:10 to 80:20 in terms of mass, but X1, X2, X3, Excellent results were obtained for both X4 and compatibility.

On the other hand, Experimental Example 1 contained an adhesive layer belonging to A1 (A1a) but did not contain an adhesive layer belonging to A2 (Table 2). As a result, compared to Experimental Examples 2 to 4, 4a, 4b, 5, 5b to 5d, 6, 7, 9, and 10, X2 was lower and X3 was higher (Table 3). From this, in comparison with Experimental Examples 2 to 4, 4a, 4b, 5, 5b to 5d, 6, 7, 9, and 10, it is desirable that the adhesive layer contains A2 as well as A1. I understand that.

In addition, in Experimental Example 8, the blending ratio of A1 and A2 (A1:A2) in the adhesive layer was 64:36 (not satisfying 95:5 to 65:35) in terms of mass, and the adhesive sheet contained a large amount of A2. (Table 2). As a result, X1 was lower than in Experimental Examples 2 to 4, 4a, 4b, 5, 5b to 5d, 6, 7, 9, and 10. Furthermore, the compatibility of A1 and A2 in the coating liquid was poor, resulting in a high haze (Table 3). From this, in comparison with Experimental Examples 2 to 4, 4a, 4b, 5, 5b to 5d, 6, 7, 9, and 10, it is desirable that the adhesive layer contains A1 and A2 in an appropriate blending ratio. I understand that.

Furthermore, in Experimental Example 11, the adhesive layer contained A1, but did not contain any material belonging to A2, and instead contained one (A2d) with Mw2 of 24,000 (less than 100,000). (Table 1, Table 2). As a result, X3 was higher than in Experimental Examples 2 to 4, 4a, 4b, 5, 5b to 5d, 6, 7, 9, and 10 (Table 3). From this, in comparison with Experimental Examples 2 to 4, 4a, 4b, 5, 5b to 5d, 6, 7, 9, and 10, the adhesive layer is A, and together with A1, the adhesive layer that belongs to A2 has Mw2 of 100,000 or more. It can be seen that it is desirable to contain

In addition, Experimental Example 12 contains A1 as an adhesive layer, but does not contain anything belonging to A2, and instead does not contain A11, and has a Mw1 of 27,000 (less than 100,000) (A1b). (Table 1, Table 2). As a result, X3 was higher than in Experimental Examples 2 to 4, 4a, 4b, 5, 5b to 5d, 6, 7, 9, and 10 (Table 3). From this, in comparison with Experimental Examples 2 to 4, 4a, 4b, 5, 5b to 5d, 6, 7, 9, and 10, the adhesive layer contained A1 as well as A2, that is, A11. However, it can be seen that it is desirable to contain one having an Mw of 100,000 or more.

In addition, in Experimental Examples 5a and 5e, materials (A1a, A2a) with Mw (Mw1, Mw2) both of 100,000 or more were used as A1 and A2, and the material used as A2 (A2a) was A1 glass. It has a glass transition temperature Tg2 higher than the transition temperature Tg1, and the blending ratio of A1 and A2 (A1:A2) satisfies 95:5 to 65:35 in terms of mass, and it does not contain C. It was something. Experimental Example 5a contained an antioxidant, whereas Experimental Example 5e did not contain an antioxidant (Tables 1 and 2). When Experimental Examples 5a and 5e were compared, X3 was lower in Experimental Example 5a (Table 2). From this, it can be seen that in comparison with Experimental Examples 5a and 5e, X3 can be further reduced by adding an antioxidant to the adhesive layer.

Claims (5)

When forming a fine pattern on a substrate through a patterning method that includes an exposure step by irradiating ultraviolet rays, a pattern forming layer is formed on the entire surface of one side of the substrate via an adhesive layer, and the entire surface of the pattern forming layer is formed on the entire surface of one side of the substrate through an adhesive layer. Adherents consisting of two single-sided laminates each having a resist formed thereon are bonded together with their respective base surfaces facing each other, and then a first mask corresponding to the fine pattern is placed on one of the single-sided laminates on the resist. At the same time, UV rays are irradiated to the other single-sided laminate while a second mask corresponding to the fine pattern is placed on the resist. An adhesive sheet used in the process of peeling from
Having an adhesive layer on each of one side and the other side of the base film,
The adhesive layer has an initial peel force of 0.05 (N/25 mm) or more at 23°C, a peel force of 0.05 (N/25 mm) or more when heated at 60°C, and is heated at 150°C for 1 hour. An adhesive sheet having a peeling force after heating at room temperature of 0.7 (N/25 mm) or less and an ultraviolet shielding rate of 90% or more. The adhesive sheet according to claim 1, wherein the adhesive sheet has a total light transmittance of 87% or more, a haze of 5% or less, and a thickness of the adhesive layer from 3 μm to 20 μm. The adhesive layer includes a first acrylic resin (A1) and a second acrylic resin (A2) having a glass transition temperature (Tg2) higher than the glass transition temperature (Tg1) of the A1, An adhesive composition comprising at least a resin component (A) in which the mass average molecular weight (Mw1) of A2 and the mass average molecular weight (Mw2) of A2 are both 100,000 or more, a crosslinking agent (B), and an ultraviolet absorber (C). It is made up of things,
The blending ratio (A1:A2) of A1 and A2 in A is 95:5 to 65:35 in terms of mass, and the blending amount of C is 5 to 40 parts by mass with respect to 100 parts by mass of A. The pressure-sensitive adhesive sheet according to claim 1 or 2. The pressure-sensitive adhesive sheet according to claim 3, wherein A1 and A2 have a Tg1 of -70 to -25°C and a Tg2 of -15 to 30 °C . The pressure-sensitive adhesive sheet according to claim 3, wherein the difference between Tg2 and Tg1 (Tg2-Tg1) is 10°C or more.