JP2006036880A - Photocurable adhesive sheet manufacturing method and manufacturing apparatus, and photocurable adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocurable pressure-sensitive adhesive sheet production method for producing a photocurable pressure-sensitive adhesive sheet having a reduced characteristic difference between both sides with a simple facility at a low cost with an arbitrary photocurable pressure-sensitive adhesive composition.
A method for producing a photocurable pressure-sensitive adhesive sheet is a method for producing a photocurable pressure-sensitive adhesive sheet having a photocurable pressure-sensitive adhesive layer from a photocurable pressure-sensitive adhesive composition, the photocurable pressure-sensitive adhesive composition. The light-curing pressure-sensitive adhesive layer in an uncured state formed by coating is irradiated with light from one side and cured until the polymerization rate becomes 30 to 73%, and then light from the other side. Is cured by irradiation to form a cured photocurable pressure-sensitive adhesive layer. As the photocurable pressure-sensitive adhesive sheet, a photocurable double-sided pressure-sensitive adhesive sheet having a configuration formed only from the photocurable pressure-sensitive adhesive layer is suitable, and each surface of the photocurable pressure-sensitive adhesive layer is composed of two separators. It is preferably protected.
[Selection figure] None

Description

  The present invention relates to a photocurable pressure-sensitive adhesive sheet manufacturing method, a photocurable pressure-sensitive adhesive sheet manufacturing apparatus, and a photocurable pressure-sensitive adhesive sheet.

  Conventionally, as a method for producing a photocurable pressure-sensitive adhesive sheet (sometimes referred to as a “photocurable sheet”), there is a production method by a single-sided irradiation method in which light is irradiated and cured only from one side of a photocurable pressure-sensitive adhesive layer. Generally used. However, in the single-sided irradiation method, in the photo-curing pressure-sensitive adhesive layer, how light strikes on the surface irradiated with light (irradiated surface) and the opposite surface (non-irradiated surface not irradiated with light) Therefore, there may be a difference in the characteristics on each surface. Specifically, for example, there may be a difference in the adhesive strength between the front and back surfaces of the photocurable double-sided pressure-sensitive adhesive sheet. Thus, the tendency that the difference in the characteristic in each surface of the front and back in a photocurable double-sided adhesive sheet becomes remarkable when light is shielded with the thickness or coloring state of a photocurable adhesive sheet.

  Therefore, by using glass powder and polyolefin powder in the photocurable pressure-sensitive adhesive layer, a composite UV-curable adhesive that prevents differences in the adhesive strength between the UV-irradiated side surface and the back surface (non-irradiated side surface). An agent composition and a double-sided pressure-sensitive adhesive tape are disclosed (see Patent Document 1). However, in this method, the material (photocurable pressure-sensitive adhesive composition) for forming the photocurable pressure-sensitive adhesive layer is restricted, and any photocurable pressure-sensitive adhesive composition cannot be used. .

  In order not to cause a difference in the characteristics of the front and back surfaces of the photo-curing double-sided pressure-sensitive adhesive sheet, essentially, light irradiation parts are installed on both sides of the photo-curing pressure-sensitive adhesive layer to be cured, Light irradiation may be performed completely from both sides, but in this case, the number of lamps in the light irradiation unit (specifically, the number of lamps or light sources) increases, resulting in an increase in cost.

  In particular, when a high-illuminance type light source (for example, a metal halide lamp or a high-pressure mercury lamp) is used as the light source, it is not preferable to install the high-illuminance type light source facing each other in terms of safety. Therefore, it becomes necessary to install alternately, or it becomes difficult to install a cooling nozzle for removing heat from the photo-curing pressure-sensitive adhesive sheet, resulting in complicated facilities.

JP 2001-311068 A

  Therefore, an object of the present invention is to use a photocurable pressure-sensitive adhesive sheet in which the difference in characteristics between both sides of the photocurable pressure-sensitive adhesive layer is reduced, using an arbitrary photocurable pressure-sensitive adhesive composition, with a simple facility and low It is providing the manufacturing method of the photocurable adhesive sheet which can be manufactured at cost, the manufacturing apparatus of a photocurable adhesive sheet, and a photocurable adhesive sheet.

  As a result of intensive studies to achieve the above-mentioned object, the present inventors first irradiate light from one surface side to the uncured photocurable pressure-sensitive adhesive layer and cure until a predetermined polymerization rate is obtained. Then, the surface of the front and back surfaces of the photocurable pressure-sensitive adhesive layer in the photocurable pressure-sensitive adhesive sheet is formed by irradiating light from the other surface side and curing to form a cured photocurable pressure-sensitive adhesive layer. It has been found that the difference in characteristics can be reduced or eliminated, and that it is easy (simple) in terms of equipment, and a photocurable pressure-sensitive adhesive sheet can be produced at low cost. The present invention has been completed based on these findings.

  That is, the present invention is a method for producing a photocurable pressure-sensitive adhesive sheet having a photocurable pressure-sensitive adhesive layer by a photocurable pressure-sensitive adhesive composition, which is formed by applying the photocurable pressure-sensitive adhesive composition. The photocurable pressure-sensitive adhesive layer in a state is irradiated with light from one side and cured until the polymerization rate reaches 30 to 73%, and then cured by irradiation with light from the other side. A photocurable pressure-sensitive adhesive sheet is produced by forming a photocurable pressure-sensitive adhesive layer in a state.

  In the method for producing a photocurable pressure-sensitive adhesive sheet of the present invention, a photocurable double-sided pressure-sensitive adhesive sheet having a configuration formed only from a photocurable pressure-sensitive adhesive layer is suitable as the photocurable pressure-sensitive adhesive sheet. Moreover, it is preferable that each surface of the photocurable pressure-sensitive adhesive layer is protected by two separators.

  The present invention is also an apparatus for producing a photocurable pressure-sensitive adhesive sheet having a photocurable pressure-sensitive adhesive layer made of a photocurable pressure-sensitive adhesive composition, wherein light is applied from one surface side of the photocurable pressure-sensitive adhesive layer. And a second light irradiation part for irradiating light from the other surface side of the photocurable pressure-sensitive adhesive layer, and a photocurable pressure-sensitive adhesive composition After irradiating light to the uncured photocurable pressure-sensitive adhesive layer formed by application of the first light irradiation part from one surface side until the polymerization rate becomes 30 to 73%, A photocurable pressure-sensitive adhesive having a configuration capable of forming a cured photocurable pressure-sensitive adhesive layer by irradiating light from the other surface side with a second light irradiation unit. A sheet manufacturing apparatus is provided.

  In the photocurable pressure-sensitive adhesive sheet production apparatus of the present invention, a photocurable double-sided pressure-sensitive adhesive sheet having a configuration formed only from a photocurable pressure-sensitive adhesive layer is suitable as the photocurable pressure-sensitive adhesive sheet. Moreover, it is preferable that each surface of the photocurable pressure-sensitive adhesive layer is protected by two separators. Furthermore, each of the first light irradiation unit and the second light irradiation unit may include a high-pressure discharge type light source as the light source, and the first irradiation zone and the second light irradiation by the first light irradiation unit. A cooling unit for removing heat from the photocurable pressure-sensitive adhesive sheet may be installed in each of the second irradiation zones formed by the unit.

  The present invention is also a photocurable pressure-sensitive adhesive sheet having a photocurable pressure-sensitive adhesive layer made of a photocurable pressure-sensitive adhesive composition, which is manufactured using the method for producing a photocurable pressure-sensitive adhesive sheet. A photocurable pressure-sensitive adhesive sheet is provided.

  According to the method for producing a photocurable sheet of the present invention, a photocurable pressure-sensitive adhesive sheet in which the difference in characteristics between both sides of the photocurable pressure-sensitive adhesive layer is reduced, using an arbitrary photocurable pressure-sensitive adhesive composition, It can be manufactured with simple equipment and at low cost.

[Method for producing photocurable pressure-sensitive adhesive sheet]
In the method for producing a photocurable pressure-sensitive adhesive sheet of the present invention, as shown in FIG. 1, one surface side is applied to an uncured photocurable pressure-sensitive adhesive layer formed by application of a photocurable pressure-sensitive adhesive composition. By irradiating with light and curing until the polymerization rate becomes 30 to 73%, by irradiating with light from the other surface side to cure, and forming a cured photocurable pressure-sensitive adhesive layer, The photocurable adhesive sheet which has the photocurable adhesive layer by the photocurable adhesive composition is manufactured. FIG. 1 is a schematic view partially showing an example of a method for producing a photocurable pressure-sensitive adhesive sheet of the present invention. In FIG. 1, 1 is a light irradiation treatment zone part in a photocurable adhesive sheet manufacturing apparatus, 1a is a first irradiation zone, 1b is a second irradiation zone, 2 is a first light irradiation part, and 2a is a first light irradiation part. The light source in 2, 3 is the second light irradiation unit, 3 a is the light source in the second light irradiation unit 3, 4 is a photocurable adhesive sheet (a photocurable adhesive sheet having a cured photocurable adhesive layer), 4 a Is a light-curing pressure-sensitive adhesive sheet member having an uncured photo-curing pressure-sensitive adhesive layer (sometimes referred to as “uncured light-curing pressure-sensitive adhesive sheet”), and 5 is a line moving direction in the light irradiation treatment zone 1 (The flow direction of the photocurable adhesive sheet 4 or the uncured photocurable adhesive sheet 4a).

  The light irradiation treatment zone unit 1 in the photocurable pressure-sensitive adhesive sheet manufacturing apparatus shown in FIG. 1 is first provided with one of the photocurable pressure-sensitive adhesive layers in the supplied (introduced) uncured photocurable pressure-sensitive adhesive sheet 4a. The first irradiation zone 1a for irradiating light from the side (lower side in FIG. 1) until the predetermined polymerization rate is reached, and then light from the other side (upper side in FIG. 1) until the cured state is reached. And a second irradiation zone 1b for irradiation. Specifically, the uncured photocurable pressure-sensitive adhesive sheet 4a has an uncured photocurable pressure-sensitive adhesive layer formed by application of the photocurable pressure-sensitive adhesive composition, and the light irradiation treatment zone 1 When the uncured photocurable pressure-sensitive adhesive sheet 4a is supplied in the direction of the line moving direction 5, the uncured photocurable pressure-sensitive adhesive layer in the uncured photocurable pressure-sensitive adhesive sheet 4a in the first irradiation zone 1a. First, the first light irradiation unit 2 is irradiated with light from the light source 2a from one side (lower side in FIG. 1) and cured until the polymerization rate reaches 30 to 73%, and then the second irradiation zone 1b. Then, the second light irradiation unit 3 causes the other side (upper side in FIG. 1) to be applied to the photocurable pressure-sensitive adhesive layer cured until the polymerization rate in the uncured photocurable pressure-sensitive adhesive sheet 4a is 30 to 73%. From the light source 3a to be cured, and the cured photocurable pressure-sensitive adhesive layer Form, the photocurable pressure-sensitive adhesive sheet (i.e., the light-curable pressure-sensitive adhesive sheet having a light-curable pressure-sensitive adhesive layer cured) manufactures 4.

  As described above, in the present invention, the uncured photocurable pressure-sensitive adhesive layer is irradiated with light from one surface side and cured until the polymerization rate becomes 30 to 73%, and then the other surface side. To form a cured photo-curing pressure-sensitive adhesive layer, which is not simply irradiated from one side and then irradiated from the other side. The light is not irradiated simultaneously or alternately. Therefore, even if any photocurable pressure-sensitive adhesive composition is used as the photocurable pressure-sensitive adhesive layer for forming the photocurable pressure-sensitive adhesive layer, it is effectively irradiated with light and photocured in an uncured state. The mold pressure-sensitive adhesive layer can be cured, and a difference in characteristics (particularly, a difference in adhesiveness) between both surfaces of the photocurable pressure-sensitive adhesive layer can be reduced or eliminated. In addition, as described above, since light is not irradiated simultaneously or alternately from both sides of the photocurable pressure-sensitive adhesive layer, the equipment of the apparatus is not complicated, and a high-illuminance type light source is used as the light source. Thus, it can be manufactured with simple equipment and at low cost.

  In the present invention, when the uncured photocurable pressure-sensitive adhesive layer is cured by irradiating light from one surface side (when irradiating and curing light for the first time), the polymerization rate is 30 to 73. It is important to perform light irradiation so that it becomes%. In this case, the lower limit of the polymerization rate may be 30% or more, preferably 35% or more (more preferably 40% or more, particularly 45% or more, especially 50% or more). In addition, the upper limit of the polymerization rate at the time of curing by irradiating light for the first time may be 73% or less, preferably 70% or less (more preferably 67% or less, particularly 65% or less). Is desirable. The effect of reducing the difference in characteristics between the front and back sides of the photo-curing pressure-sensitive adhesive layer when the light irradiation is performed outside the range of 30 to 73% when the light is irradiated and cured for the first time. Decreases, and the difference in characteristics between the front and back surfaces of the photocurable pressure-sensitive adhesive layer increases.

  On the other hand, after curing at a polymerization rate of 30 to 73%, the photocuring pressure-sensitive adhesive layer with a polymerization rate of 30 to 73% is applied to the other surface side (on the surface irradiated with light when first cured). When curing by irradiating light from the opposite surface side (when irradiating and curing light for the second time), light irradiation is performed so that the photocurable pressure-sensitive adhesive layer is cured. is important. Accordingly, the polymerization rate at the time of curing by irradiating with light for the second time is 100% as long as the photocurable pressure-sensitive adhesive layer can be regarded as being substantially cured. Desirably, it may be less than 100%. Specifically, the polymerization rate at the time of curing by irradiation with light for the second time may be, for example, 98% or more (preferably 99% or more, more preferably 99.8% or more).

In addition, the polymerization rate of a photocurable adhesive layer can be calculated | required using the measuring method of a well-known polymerization rate. Specifically, for example, the polymerization rate of the photocurable pressure-sensitive adhesive layer can be easily obtained by the following (Simple polymerization rate measurement method).
(Simple measurement method of polymerization rate)
After measuring the weight (W ₁ ) of the photocurable pressure-sensitive adhesive layer, it was dried at 130 ° C. for 3 hours, and again measured for weight (W ₂ ). From the weight change before and after this drying, the polymerization rate ( %) Is obtained from the following formula (1).
Polymerization rate (%) = (W ₂ / W ₁ ) × 100 (1)

Moreover, the polymerization rate of a photocurable adhesive layer can also be measured by a gas chromatograph. Specifically, the polymerization rate of the photocurable pressure-sensitive adhesive layer can be measured more precisely by the following (method for measuring the polymerization rate by gas chromatography).
(Measurement method of polymerization rate by gas chromatograph)
About 10 cm ² is taken from the photo-curing pressure-sensitive adhesive layer, and a so-called “aluminum foil” (aluminum foil or sheet-like aluminum base material; weight is measured in advance) on one side (one side). With the other surface open, the sample was immediately weighed and weighed to determine the weight (W ₃ ) of the photocurable pressure-sensitive adhesive layer. Placed in a jar and sealed. Then, the bottle containing the photocurable pressure-sensitive adhesive layer as a sample was heated at 150 ° C. for 30 minutes by a headspace sampler (“HP7694” manufactured by HEWLETT PACKARD), and 1.0 ml of heated gas was added. Then, it is injected into a gas chromatograph apparatus (“HP6890” manufactured by HEWLETT PACKARD), the amount of generated gas (W ₄ ) is determined, and the polymerization rate (%) is determined by the following formula (2).
Polymerization rate (%) = [(W ₃ −W ₄ ) / W ₃ ] × 100 (2)

In the method for measuring the polymerization rate by gas chromatography, the measurement conditions are as follows.
About headspace sampler Pressurization time: 0.12 minutes Loop filling time: 0.12 minutes Loop equilibration time: 0.12 minutes Injection time: 3 minutes Sample loop temperature: 160 ° C
Transfer line temperature: 200 ° C
About gas chromatograph column: DB-FFAP 1.0 μm (0.539 mmφ × 30M)
Carrier gas and flow rate: Helium (He) 5 ml / min (constant flow mode)
Column head pressure: 23 kPa (40 ° C)
Inlet: Split (Split ratio 12: 1 Temperature 250 ° C)
Column temperature: 40 ° C. (0 min) − <+ 10 ° C./min>−250° C. (9 min) [After raising the temperature from 40 ° C. to 250 ° C. at a heating rate of 10 ° C./min, hold at 250 ° C. for 9 minutes. means]
Detector: FID (temperature 250 ° C)

[Photocurable adhesive sheet manufacturing equipment]
In such a method for producing a photocurable pressure-sensitive adhesive sheet of the present invention, as shown in FIG. 1, a first light irradiation unit for irradiating light from one surface side of the photocurable pressure-sensitive adhesive layer, A second light irradiating part for irradiating light from the other surface side of the curable pressure-sensitive adhesive layer, and being formed by application of the photo-curable pressure-sensitive adhesive composition, a photocurable type in an uncured state The pressure-sensitive adhesive layer is irradiated with light from one surface side by the first light irradiation unit and cured until the polymerization rate becomes 30 to 73%, and then light is irradiated from the other surface side by the second light irradiation unit. The manufacturing apparatus of the photocurable adhesive sheet which has the structure which can be irradiated and hardened and can form the cured photocurable adhesive layer can be used.

  The 1st light irradiation part and the 2nd light irradiation part (these may be named generically as a "light irradiation part") in the manufacturing apparatus of a photocurable adhesive sheet harden the uncured photocurable adhesive layer. It is important to have a light source capable of irradiating each surface of the uncured photocurable pressure-sensitive adhesive layer with light capable of being irradiated. The light source of the light irradiation part is not particularly limited as long as it can emit light capable of curing the uncured photocurable pressure-sensitive adhesive layer. Accordingly, the light source of the light irradiation unit can be appropriately selected from known light sources according to the type of the photocurable pressure-sensitive adhesive composition for forming the photocurable pressure-sensitive adhesive layer. Specifically, as a light source, for example, a high-pressure discharge type light source (for example, a metal halide lamp, a high-pressure mercury lamp, etc.), a low-pressure discharge type light source (for example, a black light, a fluorescent lamp for insect traps, a chemical lamp, etc.), etc. Can be used. In such a light source, the wavelength and illuminance are not particularly limited, and may be appropriately selected according to the type of the photocurable pressure-sensitive adhesive composition forming the photocurable pressure-sensitive adhesive layer, the type of the light source, and the like. it can. As the light source, for example, those capable of emitting ionizing radiation (α rays, β rays, γ rays, neutron rays, electron beams, etc.) and active energy rays (particularly, ultraviolet rays) such as ultraviolet rays are suitable. Can be used. A light source can be used individually or in combination of 2 or more types.

  In the first light irradiation unit and the second light irradiation unit, one light source may be used, but usually a plurality of light sources are used. In particular, when light irradiation is performed while moving the photocurable pressure-sensitive adhesive sheet on a line, a plurality of light sources are usually used. When each of the first light irradiation unit and the second light irradiation unit has a plurality of light sources, all of the light sources in each light irradiation unit may be the same light source, and are partially or entirely different. It may be a light source. Therefore, each of the first light irradiation unit and the second light irradiation unit may include a light source in which, for example, a high pressure discharge type light source and a low pressure discharge type light source are combined.

  Moreover, the 1st light irradiation part and the 2nd light irradiation part may have the same light source, and may have a different light source. Further, the wavelength and illuminance of the light emitted from the light source may be the same or different between the first light irradiation unit and the second light irradiation unit.

  In any case, the first light irradiator is irradiated in the first irradiation zone so that the polymerization component in the photocurable pressure-sensitive adhesive layer can be cured until the polymerization rate becomes 30 to 73%. The moving speed of the line, the width of the first irradiation zone, the distance between the photocurable pressure-sensitive adhesive layer and the light source, the number of light sources, the wavelength of light, the illuminance of light, and the like can be appropriately selected. On the other hand, the second light irradiation unit polymerizes the polymerization components in the photocurable pressure-sensitive adhesive layer in the second irradiation zone, and the irradiation time or line is set so that the photocurable pressure-sensitive adhesive layer is in a cured state. The moving speed, the width of the second irradiation zone, the distance between the photocurable pressure-sensitive adhesive layer and the light source, the number of light sources, the wavelength of light, the illuminance of light, and the like can be appropriately selected.

For example, in the first light irradiation unit or the second light irradiation unit, the illuminance of light from the light source is 0.1 to 500 mW / cm ² (preferably 1 to 300 mW / cm ² , more preferably 50 to 200 mW / cm. ² ) Can be selected from the range.

  The polymerization of the photocurable pressure-sensitive adhesive layer usually proceeds rapidly at the beginning of the polymerization, but the polymerization rate decreases at the later stage. Therefore, the irradiation time of the light or the moving speed of the line, the width of the irradiation zone (first irradiation zone, second irradiation zone) by each light irradiation unit, the distance between the photocurable pressure-sensitive adhesive layer and the light source, the number of light sources, the light The wavelength, the illuminance of light, and the like can be set separately for the first light irradiation unit and the second light irradiation unit. For example, when light irradiation is performed while moving the photocurable pressure-sensitive adhesive sheet on the line at a constant line speed, the width of the first irradiation zone by the first light irradiation unit is usually larger than that by the second light irradiation unit. The width of the two irradiation zones is wider, and the number of light sources is larger in the second light irradiation section than in the first light irradiation section.

  In the first light irradiation part and the second light irradiation part, the polymerization rate cured by light irradiation is the above-described range (for example, the lower limit value of the polymerization rate at the time of curing by light irradiation for the first time, It is important to select from the range defined by the upper limit value and the range of the polymerization rate when curing by irradiating light for the second time.

  In the present invention, light irradiation may be performed on the photocurable pressure-sensitive adhesive layer from one side and then from the other side, and may be performed first from either side of the photocurable pressure-sensitive adhesive layer. Also good. Therefore, for example, as shown in FIG. 1, the light curable pressure-sensitive adhesive layer may be first irradiated with light from the lower side and then irradiated with light from the upper side. The agent layer may be irradiated with light from the upper side and then irradiated with light from the lower side.

  In the photocurable pressure-sensitive adhesive sheet manufacturing apparatus of the present invention, heat removal of the light-curable pressure-sensitive adhesive sheet and monomer in the first irradiation zone by the first light irradiation unit and the second irradiation zone by the second light irradiation unit, respectively. A cooling unit (a unit having a cooling mechanism) for preventing evaporation of components may be installed. In the production apparatus of the present invention, from one side of the photocurable pressure-sensitive adhesive layer, after irradiating light so as to have a predetermined polymerization rate, irradiating light so as to be in a cured state from the other side, Since light is not irradiated simultaneously or alternately from both sides of the photocurable pressure-sensitive adhesive layer, the equipment of the apparatus is not complicated and simple, and the cooling unit can be easily installed. ing.

  Such a cooling unit is not particularly limited, and in the production of the photocurable pressure-sensitive adhesive sheet, a known cooling unit used for heat removal of the photocurable pressure-sensitive adhesive sheet and prevention of evaporation of the monomer component. Arbitrary cooling units can be appropriately selected and used. Specifically, as the cooling unit, a cooling nozzle that can eject a cooled gas component, a cooling roll unit in which a cooled liquid component (such as cooling water) is circulated, or the like can be used. In the cooling nozzle, examples of the cooled gas component ejected include a gas component cooled to a predetermined temperature by a cooling medium such as liquid nitrogen. In addition, as temperature to cool, the temperature of the separator formed on the photocurable adhesive sheet or the photocurable adhesive layer is 30 ° C. or less (preferably 20 ° C. or less, more preferably 10 ° C. or less). It is preferred that the temperature be able to.

[Photo-curing adhesive sheet]
In the manufacturing method of the photocurable adhesive sheet of this invention, the photocurable adhesive sheet has the photocurable adhesive layer by a photocurable adhesive composition. The photocurable pressure-sensitive adhesive sheet is a photocurable double-sided pressure-sensitive adhesive sheet having a structure in which a photocurable pressure-sensitive adhesive layer is formed on both sides of a substrate (sometimes referred to as “photocurable double-sided pressure-sensitive adhesive sheet with a substrate”). A photo-curing double-sided pressure-sensitive adhesive sheet having a configuration formed only from a photo-curing pressure-sensitive adhesive layer (may be referred to as “substrate-less photo-curing double-sided pressure-sensitive adhesive sheet”) is preferable.

  The photocurable pressure-sensitive adhesive composition for forming the photocurable pressure-sensitive adhesive layer is not particularly limited as long as it is a photocurable pressure-sensitive adhesive composition that is cured by light irradiation and exhibits adhesiveness. A curable pressure-sensitive adhesive composition (for example, an acrylic photocurable pressure-sensitive adhesive composition, a polyester-based photocurable pressure-sensitive adhesive composition, an epoxy-based photocurable pressure-sensitive adhesive composition, etc.) can be selected as appropriate. A photocurable pressure-sensitive adhesive composition can be suitably used. Such a photocurable pressure-sensitive adhesive composition contains at least a monomer component or a partial polymer thereof and a photopolymerization initiator.

(Monomer component)
In the photocurable pressure-sensitive adhesive composition, (meth) acrylic acid ester is suitably used as the monomer component in the acrylic photocurable pressure-sensitive adhesive composition. As such a (meth) acrylic acid ester, a (meth) acrylic acid alkyl ester can be suitably used. As for (meth) acrylic acid ester, only 1 type may be used and 2 or more types may be used in combination.

Examples of the (meth) acrylic acid alkyl ester include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth) Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, Octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate , Undecyl (meth) acrylate, dodecyl (meth) acrylate, ( T) Decyl acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, (meta ) (Meth) acrylic acid C _1-20 alkyl ester such as eicosyl acrylate [preferably (meth) acrylic acid C _2-14 alkyl ester, more preferably (meth) acrylic acid C _2-10 alkyl ester] and the like. It is done.

  Moreover, as (meth) acrylic acid ester other than (meth) acrylic acid alkyl ester, for example, it has an alicyclic hydrocarbon group such as cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate ( And (meth) acrylic acid ester and (meth) acrylic acid ester having an aromatic hydrocarbon group such as phenyl (meth) acrylate.

  In addition, (meth) acrylic acid ester is used as a main component of a monomer component. Therefore, it is important that the ratio of (meth) acrylic acid ester [particularly (meth) acrylic acid alkyl ester] is, for example, 50% by weight or more, preferably 70% by weight or more ( More preferably, it is 80% by weight or more.

  In addition, various copolymerizable monomers (ethylenically unsaturated monomers) such as polar group-containing monomers and polyfunctional monomers may be used as the monomer component. By using a copolymerizable monomer as the monomer component, for example, the adhesive force to the adherend can be improved, or the cohesive force of a photocurable pressure-sensitive adhesive (such as a pressure-sensitive adhesive) can be increased. it can. A copolymerizable monomer can be used individually or in combination of 2 or more types.

  As the polar group-containing monomer, a monoethylenically unsaturated monomer having a polar group can be suitably used. Specifically, examples of the polar group-containing monomer include carboxyl group-containing monomers such as (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid, or anhydrides thereof (anhydrous anhydride). Maleic acid etc.); hydroxyl-containing monomers such as (meth) acrylic acid hydroxyethyl, (meth) acrylic acid hydroxypropyl, (meth) acrylic acid hydroxyalkyl such as hydroxybutyl acrylate; acrylamide, methacrylamide, Amide group-containing monomers such as N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide; amino (meth) acrylate Ethyl, dimethylaminoethyl (meth) acrylate, (meth Amino group-containing monomers such as t-butylaminoethyl acrylate; glycidyl group-containing monomers such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate; cyano group-containing monomers such as acrylonitrile and methacrylonitrile N-vinyl-2-pyrrolidone, (meth) acryloylmorpholine, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N- Examples thereof include heterocyclic-containing vinyl monomers such as vinylimidazole and N-vinyloxazole. As the polar group-containing monomer, a carboxyl group-containing monomer such as acrylic acid or an anhydride thereof is suitable.

  The amount of the polar group-containing monomer used is desirably 30% by weight or less (for example, 1 to 30% by weight, preferably 3 to 20% by weight) based on the total amount of the monomer components. If the amount of the polar group-containing monomer exceeds 30% by weight based on the total amount of the monomer components, for example, the cohesive force of the acrylic photocurable pressure-sensitive adhesive becomes too high, and the pressure-sensitive adhesiveness may decrease. is there. In addition, when there is too little usage-amount of a polar group containing monomer (for example, it is less than 1 weight% with respect to monomer component whole quantity), for example, the cohesion force of an acrylic type photocurable adhesive will fall and it will be high Shear force cannot be obtained.

  Examples of the polyfunctional monomer include hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, and neopentyl glycol di (meth). ) Acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, allyl (meth) Acrylate, vinyl (meth) acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyl di (meth) acrylate, hexyl di (meth) acrylate Such as theft and the like. Such a polyfunctional monomer can also be used as a cross-linking agent as shown below.

  The amount of the polyfunctional monomer used is desirably 0.5% by weight or less (for example, 0.01 to 0.5% by weight) with respect to the total amount of the monomer components. If the amount of the polyfunctional monomer used exceeds 0.5% by weight with respect to the total amount of the monomer components, for example, the crosslink density increases, and the necessary peeling force may not be obtained. In addition, when there is too little usage-amount of a polyfunctional monomer (for example, it is less than 0.01 weight% with respect to the monomer component whole quantity), for example, the cohesion force of an acrylic type photocurable adhesive will fall. .

  Examples of copolymerizable monomers other than polar group-containing monomers and polyfunctional monomers include vinyl esters such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene and vinyltoluene. Olefins or dienes such as ethylene, butadiene, isoprene and isobutylene; vinyl ethers such as vinyl alkyl ether; vinyl chloride; alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate Sulfonic acid group-containing monomers such as sodium vinyl sulfonate; phosphate group-containing monomers such as 2-hydroxyethylacryloyl phosphate; imide group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide; 2-methacryloyloxyethyl Isocyanate group-containing monomers such as isocyanate; fluorine-containing (meth) acrylate; and a silicon atom-containing (meth) acrylate.

(Photopolymerization initiator)
The photopolymerization initiator is not particularly limited, and for example, benzoin ether photopolymerization initiator, acetophenone photopolymerization initiator, α-ketol photopolymerization initiator, aromatic sulfonyl chloride photopolymerization initiator, photoactivity An oxime photopolymerization initiator, a benzoin photopolymerization initiator, a benzyl photopolymerization initiator, a benzophenone photopolymerization initiator, a ketal photopolymerization initiator, a thioxanthone photopolymerization initiator, or the like can be used. A photoinitiator can be used individually or in combination of 2 or more types.

  Specifically, examples of the benzoin ether photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane- Examples include 1-one and anisole methyl ether. Examples of the acetophenone photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloro. Examples include acetophenone. Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) -phenyl] -2-hydroxy-2-methylpropane-1- ON etc. are mentioned. Examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime.

  The benzoin photopolymerization initiator includes, for example, benzoin. Examples of the benzyl photopolymerization initiator include benzyl. Examples of the benzophenone photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, polyvinyl benzophenone, α-hydroxycyclohexyl phenyl ketone, and the like. Examples of the ketal photopolymerization initiator include benzyl dimethyl ketal. Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4. -Diisopropylthioxanthone, dodecylthioxanthone and the like are included.

  Moreover, as another photoinitiator, an acyl phosphine oxide etc. are mentioned, for example.

  The amount of the photopolymerization initiator used is not particularly limited. However, if the amount is too large, a low molecular weight polymer (copolymer) is likely to be generated. On the other hand, if the amount is too small, the polymerization reaction is difficult to proceed. For example, 0.01 to 2 parts by weight (preferably 0.05 to 1 part by weight) with respect to 100 parts by weight of all monomer components [particularly, all monomer components having (meth) acrylic acid ester as the main monomer component] It is desirable to select from the range.

  In the activation of the photopolymerization initiator, light (particularly, active energy ray) can be used. In such light, examples of the active energy ray include ionizing radiation such as α rays, β rays, γ rays, neutron rays, electron rays, and ultraviolet rays, and ultraviolet rays are particularly preferable. The irradiation energy of light such as active energy rays is not particularly limited as long as the photopolymerization initiator can be activated to cause a reaction of the monomer component. Such light is used in the first light irradiation unit and the second light irradiation unit.

  In addition, the photocurable pressure-sensitive adhesive composition may contain appropriate additives in addition to the above components (monomer component or a partial polymer thereof, a photopolymerization initiator, etc.). Examples of such additives include fillers, crosslinking agents (for example, polyisocyanate crosslinking agents, silicone crosslinking agents, epoxy crosslinking agents, alkyl etherified melamine crosslinking agents), and tackifiers (for example, Rosin derivative resin, polyterpene resin, petroleum resin, oil-soluble phenol resin, etc., solid, semi-solid or liquid at normal temperature), plasticizer, anti-aging agent, antioxidant, colorant (pigment, dye, etc.), interface An active agent etc. are mentioned.

  In particular, a filler can be suitably used as an additive in order to increase the shear adhesive force or improve workability. Such a filler may be either an inorganic filler or an organic filler. The inorganic filler is not particularly limited, and examples thereof include silica, calcium carbonate, clay, titanium oxide, glass balloon, and alumina balloon. The organic filler is not particularly limited, and examples thereof include beads and balloons made of various resins such as polyester beads, polyvinylidene chloride balloons, and polyacrylic balloons.

  In addition, a crosslinking agent and a polyfunctional monomer can be used as a cross-linking agent. As such a crosslinking agent and polyfunctional monomer, those exemplified above can be used. The amount of the cross-linking agent used is 0.5% by weight or less (for example, 0.01 to 0.5% by weight) with respect to the total amount of the monomer components, similarly to the amount of the polyfunctional monomer used. It is desirable. When the amount of the cross-linking agent used exceeds 0.5% by weight with respect to the total amount of the monomer components, for example, the crosslinking density becomes high, and a necessary peeling force may not be obtained. For example, the cohesive force of the acrylic photo-curing pressure-sensitive adhesive is reduced.

  Moreover, in order to color a photocurable adhesive layer, the pigment (colored pigment) may be used by the usage-amount which does not inhibit photopolymerization. As the photocurable pressure-sensitive adhesive sheet, black is often preferred, and as the pigment, a black pigment such as carbon black is preferably used. The amount of pigment used can be appropriately selected according to the type of pigment. For example, the amount of carbon black used is preferably 1% by weight or less with respect to the total amount of monomer components, and if it exceeds 1% by weight, photopolymerization may not be performed.

  By applying such a photocurable pressure-sensitive adhesive composition to a predetermined surface of a support, a photocurable pressure-sensitive adhesive sheet member having an uncured photocurable pressure-sensitive adhesive layer (uncured photocurable pressure-sensitive adhesive) Sheet). In addition, as a photocurable adhesive composition, the photocurable adhesive obtained by adjusting a monomer mixture by mixing a monomer component, a photoinitiator, and an additive as needed, for example. The composition may be a composition obtained by mixing a monomer component, a photopolymerization initiator, and an additive as necessary, and then irradiating light to polymerize only a part of the monomer component. It may be a photocurable pressure-sensitive adhesive composition (syrup). As the photocurable pressure-sensitive adhesive composition, a photocurable pressure-sensitive adhesive composition (syrup) having a partially polymerized monomer component obtained by polymerizing a part of the monomer component is preferably used.

  The thickness of the uncured photocurable pressure-sensitive adhesive layer is not particularly limited, but is 0.4 mm or more (preferably 0.8 mm or more, more preferably 1 mm or more) in order to effectively express the effects of the present invention. ) Is preferable. If the thickness of the uncured photocurable pressure-sensitive adhesive layer exceeds 5 mm, photocuring by light irradiation becomes difficult, so the upper limit of the thickness of the uncured photocurable pressure-sensitive adhesive layer is 5 mm or less. (Preferably 4 mm or less, more preferably 3 mm or less).

  In applying the photocurable pressure-sensitive adhesive composition, for example, a conventional coater (for example, comma roll coater, die roll coater, gravure roll coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife) A coater, a spray coater, etc.).

  The predetermined surface of the support on which the photocurable pressure-sensitive adhesive composition is applied can be any surface of the release surface (non-adhesive surface) of the separator or the substrate for the pressure-sensitive adhesive sheet. When the photocurable pressure-sensitive adhesive sheet is a substrate-less photocurable double-sided pressure-sensitive adhesive sheet, the predetermined surface of the support to which the photocurable pressure-sensitive adhesive composition is applied is usually the release surface of the separator.

  A conventional release paper or the like can be used as the separator (release liner). Specifically, as the separator, for example, in addition to a substrate having a release treatment layer (release treatment layer) with a release treatment agent (release treatment agent) on at least one surface, a fluorine-based polymer (eg, polytetrafluoroethylene). Low adhesive substrates made of fluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene / hexafluoropropylene copolymer, chlorofluoroethylene / vinylidene fluoride copolymer, etc. A low-adhesive substrate made of an adhesive polymer (for example, an olefin resin such as polyethylene or polypropylene) can be used. In the case of a low-adhesive substrate, both surfaces can be used as a release surface. On the other hand, in a substrate having a release treatment layer, the surface of the release treatment layer is changed to a release surface (release treatment surface or non-adhesive surface). Can be used as a sex processing surface).

  As the separator, for example, a separator (base material having a release treatment layer) in which a release treatment layer is formed on at least one surface of the separator base material can be suitably used. Examples of the separator substrate include polyester films (polyethylene terephthalate film, etc.), olefin resin films (polyethylene film, polypropylene film, etc.), polyvinyl chloride films, polyimide films, polyamide films (nylon film), rayon films, etc. In addition to plastic base film (synthetic resin film) and papers (quality paper, Japanese paper, kraft paper, glassine paper, synthetic paper, top coat paper, etc.), these are laminated by lamination or coextrusion. (2-3 layer composite) etc. are mentioned. As a separator substrate, a plastic substrate film (especially polyethylene terephthalate film) that can block oxygen is used when light irradiation is not performed in air or in an inert gas atmosphere. A substrate can be suitably used.

  On the other hand, the release treatment agent constituting the release treatment layer is not particularly limited, and for example, a silicone release treatment agent, a fluorine release treatment agent, a long-chain alkyl release treatment agent, or the like is used. it can. A mold release processing agent can be used individually or in combination of 2 or more types.

  In addition, as a separator, what can permeate | transmit at least the light effective in hardening the uncured photocurable adhesive layer can be used suitably. The thickness and manufacturing method of the separator are not particularly limited.

  When the photocurable pressure-sensitive adhesive sheet is a substrate-less photocurable double-sided pressure-sensitive adhesive sheet, both sides of the photocurable pressure-sensitive adhesive layer are protected by respective separators (separator / photocurable pressure-sensitive adhesive layer / It is preferable to have a form having a separator layer structure. Of course, it is important for the photocurable pressure-sensitive adhesive sheet to have a laminated form so that the release surface of the separator is in contact with the surface of the photocurable pressure-sensitive adhesive layer.

  Therefore, in the present invention, the uncured photocurable pressure-sensitive adhesive layer (uncured photocurable pressure-sensitive adhesive sheet) that is irradiated with light is uncured and has both sides protected by respective separators. A curable pressure-sensitive adhesive layer can be suitably used. That is, as the photocurable pressure-sensitive adhesive sheet of the present invention, one surface side of the photocurable pressure-sensitive adhesive layer is applied to a photocurable pressure-sensitive adhesive layer in an uncured state and both surfaces are protected by respective separators ( That is, after irradiating light from one separator side) and curing until the polymerization rate reaches 30 to 73%, light is emitted from the other surface side (that is, the other separator side) of the photocurable pressure-sensitive adhesive layer. A photocurable pressure-sensitive adhesive sheet obtained by irradiating and curing until a cured state is formed to form a cured photocurable pressure-sensitive adhesive layer is suitable. As described above, when an uncured photocurable pressure-sensitive adhesive layer is used as an uncured photocurable pressure-sensitive adhesive sheet and is sandwiched between separators, the uncured photocurable pressure-sensitive adhesive layer includes: Since the light is irradiated through the separator, it is important that the separator can transmit at least light effective for curing the uncured photocurable pressure-sensitive adhesive layer.

  In this invention, as a photocurable adhesive sheet produced by the said manufacturing method, it may have the form wound by roll shape, and may have the form on which the sheet | seat was laminated | stacked. . That is, the photocurable pressure-sensitive adhesive sheet of the present invention can have a form such as a tape or sheet.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In the following Examples and Comparative Examples, the polymerization rate (%) was determined by the following (Method for measuring polymerization rate).
(Method for measuring polymerization rate)
After measuring the weight (W ₁ ) of the photocurable pressure-sensitive adhesive composition and the photocurable pressure-sensitive adhesive layer, it is dried at 130 ° C. for 3 hours, and the weight (W ₂ ) is measured again. And a polymerization rate (%) is calculated | required from following formula (1).
Polymerization rate (%) = (W ₂ / W ₁ ) × 100 (1)

(Example 1)
A monomer mixture in which 90 parts by weight of 2-ethylhexyl acrylate and 10 parts by weight of acrylic acid were mixed as a monomer component, and a trade name “Irgacure 651” (manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator. ): After 0.2 part by weight was mixed and mixed, ultraviolet rays (UV) were irradiated in a nitrogen atmosphere to prepare a partially polymerized composition (syrup). The polymerization rate of this syrup was determined to be 8%.

  The syrup: 100 parts by weight, as a photopolymerization initiator, trade name “Irgacure 184” (manufactured by Ciba Specialty Chemicals): 0.2 part by weight, 1,6-hexanediol dimer as a cross-linking agent Acrylate (polyfunctional monomer): 0.15 parts by weight, Pigment (trade name “Icrolith Black CT” manufactured by Ciba Specialty Chemicals, Inc., containing 35% by weight of carbon black): 0. 02 parts by weight and glass balloon (trade name “Cell Star Z-27” manufactured by Tokai Kogyo Co., Ltd.): 10 parts by weight were mixed to prepare a coating liquid (photocurable pressure-sensitive adhesive composition).

  After the defoaming of the coating liquid, a non-adhesive treated surface of a polyethylene terephthalate film (thickness: 50 μm) subjected to non-adhesive treatment as a separator has a thickness after drying and curing of 1.2 mm. To form an uncured photocurable pressure-sensitive adhesive layer, and a non-adhesive polyethylene terephthalate film (thickness) as a separator on the photocurable pressure-sensitive adhesive layer. : 50 μm) is laminated in such a manner that the non-adhesive treatment surface is in contact with the surface of the photocurable pressure-sensitive adhesive layer, and a photocurable pressure-sensitive adhesive sheet member having an uncured photocurable pressure-sensitive adhesive layer (uncured light) A curable pressure-sensitive adhesive sheet (sometimes referred to as “web”) was prepared.

The said web was supplied to the light irradiation process zone part in the manufacturing apparatus of a photocurable adhesive sheet as shown in FIG. Specifically, the light irradiation treatment zone unit in the photocurable pressure-sensitive adhesive sheet manufacturing apparatus first applies light to the supplied web from one side (for example, the lower side) until a predetermined polymerization rate is reached. A first irradiation zone for irradiating and a second irradiation zone for irradiating light from the other side (for example, the upper side) until the cured state is reached. The metal halide lamp (light source) with a maximum illuminance of about 100 mW / cm ² from one surface side (the lower surface side) of the web while moving in the first irradiation zone at a constant speed. After irradiating with ultraviolet rays until the polymerization rate reaches 41%, it is supplied into the second irradiation zone, and the inside of the second irradiation zone has a constant speed (the moving speed in the first irradiation zone and On the other side of the web From; (upper surface side surface side opposite to the surface irradiated in the first irradiation zone), the maximum illuminance by about 100 mW / cm ² of a metal halide lamp (light source), by irradiating ultraviolet rays, It was completely cured to obtain a substrate-less type photocurable pressure-sensitive adhesive sheet (polymerization rate was almost 100%).

(Example 2)
In the same manner as in Example 1, a photocurable pressure-sensitive adhesive sheet member (web) having an uncured photocurable pressure-sensitive adhesive layer was prepared, and the polymerization rate in the first irradiation zone was 51%. Except for this, ultraviolet rays were irradiated in the same manner as in Example 1 to obtain a substrate-less type photocurable pressure-sensitive adhesive sheet.

(Example 3)
In the same manner as in Example 1, a photocurable pressure-sensitive adhesive sheet member (web) having an uncured photocurable pressure-sensitive adhesive layer was produced, and the polymerization rate in the first irradiation zone was 63%. Except for this, ultraviolet rays were irradiated in the same manner as in Example 1 to obtain a substrate-less type photocurable pressure-sensitive adhesive sheet.

(Example 4)
Similarly to Example 1, a photocurable pressure-sensitive adhesive sheet member (web) having an uncured photocurable pressure-sensitive adhesive layer was produced, and the polymerization rate in the first irradiation zone was 69%. Except for this, ultraviolet rays were irradiated in the same manner as in Example 1 to obtain a substrate-less type photocurable pressure-sensitive adhesive sheet.

(Comparative Example 1)
In the same manner as in Example 1, a photocurable pressure-sensitive adhesive sheet member (web) having an uncured photocurable pressure-sensitive adhesive layer was produced. The web is supplied into the second irradiation zone without being supplied into the first irradiation zone, and a constant speed (the same speed as the movement speed in the first irradiation zone in Example 1) is supplied in the second irradiation zone. ) From one surface side (upper surface side) of the web while irradiating it with ultraviolet rays from a metal halide lamp (light source) having a maximum illuminance of about 100 mW / cm ² to completely cure the web. A material-less photocurable adhesive sheet was obtained.

  That is, in the comparative example 1, light irradiation is performed only from one surface side of the web.

(Comparative Example 2)
In the same manner as in Example 1, a photocurable pressure-sensitive adhesive sheet member (web) having an uncured photocurable pressure-sensitive adhesive layer was prepared, and the polymerization rate in the first irradiation zone was 29%. Except for this, ultraviolet rays were irradiated in the same manner as in Example 1 to obtain a substrate-less type photocurable pressure-sensitive adhesive sheet.

(Comparative Example 3)
In the same manner as in Example 1, a photocurable pressure-sensitive adhesive sheet member (web) having an uncured photocurable pressure-sensitive adhesive layer was prepared, and the polymerization rate in the first irradiation zone was 75%. Except for this, ultraviolet rays were irradiated in the same manner as in Example 1 to obtain a substrate-less type photocurable pressure-sensitive adhesive sheet.

(Evaluation)
For the substrate-less type photocurable pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples, after peeling the separator, the adhesive strength of each surface (upper surface, lower surface) was determined by the following adhesive force measurement method. The difference in adhesive strength between each surface of the material-less type photocurable pressure-sensitive adhesive sheet was determined.

(Adhesive strength measurement method)
A photocurable pressure-sensitive adhesive sheet is cut to a width of 25 mm to prepare a sample. After bonding one surface of the sample to a polished stainless steel plate by a one-way crimping method with a 5 kg roller, the other surface of the sample is adhered to a polyester film (thickness: 50 μm) to produce a test piece. . This test piece was aged for 20 minutes in an RT atmosphere [(20 ± 2) ° C., (65 ± 5)% RH atmosphere], and then photocured under the conditions of a tensile rate of 50 mm / min and a 180 ° peel. The mold pressure-sensitive adhesive sheet is peeled from the stainless steel plate, and the adhesive force (N / 25 mm) on one surface of the photocurable pressure-sensitive adhesive sheet is measured. Similarly, the adhesive force (N / 25 mm) on the other surface of the photocurable pressure-sensitive adhesive sheet is measured. Then, a difference (absolute value) in adhesive strength between both surfaces is obtained. The measurement results are shown in Table 1.

  As is clear from Table 1, the polymerization rate in the first irradiation zone is set within a predetermined range, and then the remainder is polymerized in the second irradiation zone, whereby the adhesive force on both sides of the photocurable pressure-sensitive adhesive sheet is obtained. It was confirmed that the difference between the two was reduced. Therefore, it was confirmed that the production method can eliminate or suppress the occurrence of a difference in physical properties on both sides of the photocurable pressure-sensitive adhesive sheet.

It is the schematic which shows partially an example of the manufacturing method of the photocurable adhesive sheet of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light irradiation process zone part in the manufacturing apparatus of a photocurable adhesive sheet 1a 1st irradiation zone 1b 2nd irradiation zone 2 1st light irradiation part 2a Light source in 1st light irradiation part 2 3 2nd light irradiation part 3a 2nd light Light source in irradiation unit 3 4 Photo-curing pressure-sensitive adhesive sheet 4a Photo-curing pressure-sensitive adhesive sheet member having uncured photo-curing pressure-sensitive adhesive layer 5 Line moving direction in light irradiation treatment zone 1

Claims (9)

A method for producing a photocurable pressure-sensitive adhesive sheet having a photocurable pressure-sensitive adhesive layer by a photocurable pressure-sensitive adhesive composition, which is an uncured photocurable pressure-sensitive adhesive formed by application of a photocurable pressure-sensitive adhesive composition The agent layer is irradiated with light from one side and cured until the polymerization rate reaches 30 to 73%, and then cured by irradiating with light from the other side, and the cured photocurable adhesive A method for producing a photocurable pressure-sensitive adhesive sheet, comprising forming an agent layer. The method for producing a photocurable pressure-sensitive adhesive sheet according to claim 1, wherein the photocurable pressure-sensitive adhesive sheet is a photocurable double-sided pressure-sensitive adhesive sheet having a configuration formed only from a photocurable pressure-sensitive adhesive layer. The method for producing a photocurable pressure-sensitive adhesive sheet according to claim 2, wherein each surface of the photocurable pressure-sensitive adhesive layer is protected by two separators. An apparatus for producing a photocurable pressure-sensitive adhesive sheet having a photocurable pressure-sensitive adhesive layer with a photocurable pressure-sensitive adhesive composition, comprising: a first for irradiating light from one side of the photocurable pressure-sensitive adhesive layer It has 1 light irradiation part and the 2nd light irradiation part for irradiating light from the other surface side of a photocurable adhesive layer, and was formed by application | coating of a photocurable adhesive composition The uncured photocurable pressure-sensitive adhesive layer is irradiated with light from the one surface side by the first light irradiating part and cured until the polymerization rate becomes 30 to 73%, and then from the other surface side. An apparatus for producing a photocurable pressure-sensitive adhesive sheet, characterized by having a configuration capable of forming a cured photocurable pressure-sensitive adhesive layer by irradiating light with a two-light irradiation unit. The apparatus for producing a photocurable pressure-sensitive adhesive sheet according to claim 4, wherein the photocurable pressure-sensitive adhesive sheet is a photocurable double-sided pressure-sensitive adhesive sheet having a configuration formed only from a photocurable pressure-sensitive adhesive layer. The apparatus for producing a photocurable pressure-sensitive adhesive sheet according to claim 5, wherein each surface of the photocurable pressure-sensitive adhesive layer is protected by two separators. The apparatus for producing a photocurable pressure-sensitive adhesive sheet according to any one of claims 4 to 6, wherein each of the first light irradiation unit and the second light irradiation unit has a high-pressure discharge type light source as a light source. The cooling part for the heat removal of a photocurable adhesive sheet is respectively installed in the 1st irradiation zone by a 1st light irradiation part, and the 2nd irradiation zone by a 2nd light irradiation part. The manufacturing apparatus of the photocurable adhesive sheet as described in any one of the items. It is a photocurable adhesive sheet which has a photocurable adhesive layer by a photocurable adhesive composition, Comprising: Utilizing the manufacturing method of the photocurable adhesive sheet in any one of Claims 1-3 A photocurable pressure-sensitive adhesive sheet characterized by being manufactured.

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