JP2003013015A - Method of production for pressure sensitive adhesive sheet and pressure sensitive adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing a pressure sensitive adhesive sheet using a UV-curing adhesive composition, excellent in productivity including possibility of a high speed polymerization, balance of adhesion such as adhesive strength, cohesive strength or the like and accuracy of the surface of the adhesive. SOLUTION: This method for producing the pressure sensitive adhesive sheet having an adhesive layer comprising a cured polymerized product of the UV- curing adhesive composition by coating the UV-curing adhesive composition including a vinyl-based monomer as the main ingredient on a material and then irradiating UV-ray, the UV-irradiating process comprises a first process irradiating UV-ray having >=30 mW/cm<2> of optical intensity of illumination and a second process irradiating UV-ray having intensity of illumination lower than the first process to substantially complete the polymerization reaction.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a pressure-sensitive adhesive sheet. The present invention also relates to the pressure-sensitive adhesive sheet obtained by the manufacturing method, and further to the pressure-sensitive adhesive formed on the substrate of the pressure-sensitive adhesive sheet.

[0002]

2. Description of the Related Art Conventionally, acrylic pressure-sensitive adhesives have been prepared by solution polymerization of a vinyl-based monomer having an alkyl acrylate-based monomer as a main component, and the solvent-based adhesive is applied to a substrate and dried. As a result, pressure-sensitive adhesive sheets have been manufactured. In recent years, pressure-sensitive adhesive sheets have been manufactured using ultraviolet curable adhesive compositions in consideration of air pollution, environmental problems and the like. The UV-curable adhesive composition can be used without a solvent and is particularly advantageous in terms of safety and environment.

As a method for producing a pressure-sensitive adhesive sheet or tape using an ultraviolet-curable adhesive composition, for example, US Pat. No. 4,181,752 discloses a photopolymerization of a vinyl-based monomer containing an alkyl acrylate-based monomer as a main component. The substrate is coated or impregnated with the liquid composition added with the initiator, and the illuminance at a wavelength of 300 to 400 nm is 0.1.
There is disclosed a method of polymerizing the vinyl-based monomer by irradiating with ultraviolet rays of ˜7 mW / cm ² . This method is to increase the molecular weight of the polymer by the vinyl monomer by making the light intensity of ultraviolet light relatively low,
As a result, the performance (cohesion) of the adhesive is improved. However, since the photopolymerization rate is proportional to the square root of the product of the amount of photopolymerization initiator and the illuminance of ultraviolet light, when UV irradiation with a low irradiation degree is performed as in the above method, the cohesive force is improved by the increase in the molecular weight, but the polymerization It slows down and causes production problems. In view of such a problem, it is conceivable to increase the amount of the photopolymerization initiator in the case of irradiating with ultraviolet light of low illuminance in consideration of productivity. However, when a large amount of the photopolymerization initiator is added, the molecular weight of the product does not become sufficiently high, and the cohesive force required for the adhesive cannot be obtained, resulting in deterioration of performance.

To solve these problems, Japanese Patent Publication No. 7-538
In No. 49, the light illuminance is 0.1 to 30 mW / cm ^{2 at the beginning.}
A method is shown in which both productivity and adhesive performance can be achieved by irradiating at least 90% by weight of the vinyl-based monomer to cause a polymerization reaction, and then irradiating with ultraviolet light having a higher light illuminance than the above light illuminance. ing. However, in the above method, since the ultraviolet irradiation at the start of irradiation has a low illuminance, the induction period until the start of polymerization is long, and since irradiation with low illuminance of ultraviolet rays is performed until most of the polymerization reaction ends, the polymerization reaction time There is a problem that it becomes long and the productivity is poor. In addition, since the polymerization rate is slow, it takes time for the shape of the sheet to stabilize in the ultraviolet irradiation zone after coating, the adhesive surface thickness is not sufficient, and the adhesive surface accuracy is likely to be rough. The problem of occurs.

[0005]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above problems, and is a method for producing a pressure-sensitive adhesive sheet using an ultraviolet-curable adhesive composition,
An object of the present invention is to provide a method for producing a pressure-sensitive adhesive sheet which is capable of high-speed polymerization and is excellent in productivity, and also has an excellent balance of adhesive strength such as adhesive strength and cohesive strength, and good adhesive surface precision of the adhesive layer. To do. Another object of the present invention is to provide a pressure-sensitive adhesive sheet obtained by the manufacturing method, and further to provide a pressure-sensitive adhesive formed on a substrate of the pressure-sensitive adhesive sheet.

[0006]

Means for Solving the Problems The present inventors have found that the above objects can be achieved by the manufacturing method of the pressure-sensitive adhesive sheet manufacturing method shown below as a result of diligent research to solve the above problems. The invention was completed.

That is, according to the present invention, a UV-curable adhesive composition containing a vinyl-based monomer as a main component is coated on a substrate and then irradiated with UV rays to polymerize and cure the UV-curable adhesive composition. In the method for producing a pressure-sensitive adhesive sheet having an adhesive layer composed of a material, the ultraviolet irradiation step comprises a first step of performing ultraviolet irradiation with a light illuminance of 30 mW / cm ² or more, and then an ultraviolet irradiation with a light illuminance lower than that of the first step. And a second step of substantially completing the polymerization reaction.

In the present invention, first, the first step of ultraviolet irradiation is carried out.
Light illuminance of 30 mW / cm ² UV irradiation above
I do. In this way, in the first stage ultraviolet rays of relatively high illuminance
By irradiating, the polymerization of vinyl monomer is started.
The high-speed polymerization can shorten the polymerization induction period
Productivity is improved. Also, the polymerization reaction proceeded rapidly.
Therefore, the obtained sheet shape is stable and the adhesive surface accuracy is improved.
The light illuminance in the first step is 35 mW / cm² The above is
preferable. The light illuminance in the first step is 30 to 350 mW.
/ Cm² It is preferable to carry out in the range of.

Next, in the second step, ultraviolet rays having an illuminance lower than that of the light irradiation in the first step are irradiated until the polymerization reaction is substantially completed, so that the polymerization cured product of the ultraviolet curable adhesive composition has a high molecular weight. Thus, an adhesive layer having an excellent balance of adhesive performance such as adhesive strength and cohesive strength can be obtained. The substantial completion of the polymerization reaction means that the polymerization rate of the cured polymer is about 98% or more.

In the present invention, the ultraviolet-curable adhesive composition containing a vinyl-based monomer as a main component is coated on a substrate and then irradiated with ultraviolet rays to polymerize and cure the ultraviolet-curable adhesive composition. In the method for producing a pressure-sensitive adhesive sheet having an adhesive layer composed of a material, the ultraviolet irradiation step comprises a first step of performing ultraviolet irradiation with a light illuminance of 30 mW / cm ² or more, and then an ultraviolet irradiation with a light illuminance lower than that of the first step. Has a second step of increasing the degree of polymerization of the cured product of the UV-curable adhesive composition to at least 70%, and then a third step of irradiating the UV with a light illuminance of 30 mW / cm ² or more to substantially complete the polymerization reaction. A method of manufacturing a pressure-sensitive adhesive sheet, comprising:

In order to further improve the productivity in the method for producing the pressure-sensitive adhesive sheet of the present invention, the UV-curable adhesive composition of the UV-curable adhesive composition can be obtained without substantially completing the polymerization by the UV irradiation in the second step. To further shorten the time until the completion of the polymerization reaction by setting the polymerization rate of the cured product to at least 70% and then irradiating it again with UV light of relatively high illuminance of 30 mW / cm ² or more for the required time. Is possible. The light illuminance of the third step is the same as that of the first step.
It is preferably 35 mW / cm ² or more. The light illuminance in the third step is also preferably in the range of 30 to 350 mW / cm ² .

In the method for producing a pressure-sensitive adhesive sheet, the ultraviolet irradiation time in the first step is preferably 20% or less of the total irradiation time of ultraviolet rays.

When the time of the relatively high illuminance ultraviolet irradiation in the first step is prolonged, the time of the relatively low illuminance ultraviolet irradiation in the second step is shortened, so that the polymerized and cured product of the ultraviolet curable adhesive composition can be sufficiently obtained. Since it is difficult to obtain an adhesive layer that does not have a high molecular weight and has a good balance of adhesive properties such as adhesive strength and cohesive strength, the ultraviolet irradiation time in the first step is 20% of the total irradiation time of ultraviolet rays.
Or less, preferably 15% or less, more preferably 10%
It is the following. The UV irradiation time in the first step is usually preferably 2% or more of the total UV irradiation time. The polymerization rate of the ultraviolet curable adhesive composition in the first step is preferably 40% or less, preferably 30% or less, more preferably 20% or less.

In the method for producing the pressure-sensitive adhesive sheet, the light illuminance of ultraviolet rays in the second step is 30 mW / cm.
It is preferably less than ² .

The light illuminance due to the UV irradiation in the second step is not particularly limited as long as it is lower than the light illuminance in the first step, but in order to make the polymerization cured product of the UV curable adhesive composition have a high molecular weight, The light illuminance of ultraviolet light in the two steps is less than 30 mW / cm ² , more preferably 0.2.
-25 mW / cm ² , and more preferably 1-10 mW / cm ² .

The present invention also relates to the pressure-sensitive adhesive sheet obtained by the method for producing the pressure-sensitive adhesive sheet.
Further, the present invention relates to a pressure-sensitive adhesive formed on a substrate in the pressure-sensitive adhesive sheet obtained by the method for producing a pressure-sensitive adhesive sheet.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The ultraviolet-curable adhesive composition of the present invention contains a vinyl-based monomer used as an adhesive composition as a main component. The vinyl-based monomer has an alkyl (meth) acrylate as a main component. In addition, with an alkyl (meth) acrylate, means an alkyl acrylate and / or an alkyl methacrylate, and the following (meth) has the same meaning.

As the alkyl (meth) acrylate,
The alkyl group has a carbon number in the range of about 1 to 14, and preferably the alkyl group has a carbon number in the range of about 4 to 14. Examples of such alkyl (meth) acrylates include methyl (meth) acrylate and n-
Examples thereof include butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, and isononyl (meth) acrylate.

The UV-curable adhesive composition may contain, in addition to the alkyl (meth) acrylate, a polar group-containing monomer copolymerizable therewith. Examples of polar group-containing monomers include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and other carboxyl group-containing monomers; maleic anhydride, anhydrous Acid anhydride monomers such as itaconic acid; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4- (meth) acrylic acid
Hydroxybutyl, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) Hydroxyl group-containing monomer such as methyl (meth) acrylate; styrenesulfonic acid, allylsulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, (meth) acrylamidopropanesulfonic acid, sulfopropyl (meth) acrylate, ( (Meth) acryloyloxynaphthalenesulfonic acid-containing monomers such as sulfonic acid group; 2-hydroxyethyl acryloyl phosphate-containing monomers such as phosphoric acid group; acrylamide, acrylonitrile, acryloylmorpholine Isobornyl acrylate and styrene.

These polar group-containing monomers can be contained in a proportion of 30% by weight or less based on the total vinyl monomers. The polar group-containing monomer is 10 of all vinyl-based monomers.
It is preferably contained in a proportion of not more than wt%. These polar group-containing monomers preferably contain 1% by weight or more, and more preferably 2% by weight or more of the total vinyl-based monomers in terms of adhesive properties. That is, the ultraviolet-curable adhesive composition has an alkyl (meth) as a vinyl-based monomer.
Those containing 70 to 99% by weight of acrylate, 30 to 1% by weight of polar group-containing monomer, particularly 90 to 98% by weight of alkyl (meth) acrylate, and 10 to 2% by weight of polar group-containing monomer are preferable.

The UV-curable adhesive composition contains a photopolymerization initiator. As the photopolymerization initiator, benzoin methyl ether, benzoin isopropyl ether, 2,2-
Benzoin ethers such as dimethoxy-1,2-diphenylethan-1-one, substituted benzoin ethers such as anisole methyl ether, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxy-cyclohexyl -Phenyl-
Substituted acetophenone such as ketone, substituted alpha-ketol such as 2-methyl-2-hydroxypropiophenone, aromatic sulfonyl chloride such as 2-naphthalene sulfonyl chloride, 1-phenyl-1,1-propanedione-2- (o- Examples thereof include photoactive oximes such as etoxycarbonyl) -oxime and acylphosphine oxides. These photopolymerization initiators are added in an amount of 0.01 to 5 with respect to 100 parts by weight of the vinyl-based monomer.
It is used in a proportion of parts by weight, preferably 0.1 to 3 parts by weight.

The UV-curable adhesive composition may contain, in addition to the above-mentioned components, a polyfunctional (meth) acrylate having two or more functional groups. Examples of polyfunctional (meth) acrylates include trimethylolpropane tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth). Acrylate 1,2-ethylene glycol di (meth) acrylate, 1,6-hexanediol (meth) diacrylate, 1,12-dodecanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly ) Propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate and the like can be mentioned.

The amount of these polyfunctional (meth) acrylates to be used varies somewhat depending on the number of functional groups, etc., but the insoluble fraction of the cured polymer when the polymerization of the UV-curable adhesive composition is substantially completed. 5 to 90% by weight, preferably 10
It is preferable to add 70% by weight, more preferably 20 to 50% by weight. When a polyfunctional (meth) acrylate is used in such a range, even if a decrease in cohesive force due to chain transfer to a tackifier or the like is observed, this is compensated for by the crosslinking effect of the above-mentioned monomer and a good cohesive force is obtained. Can be maintained and the holding property is improved. The insoluble fraction is obtained by weighing the polymerized cured product, putting it in ethyl acetate, and leaving it at room temperature for 1 week or more, then taking out only the insoluble component and drying and removing the solvent contained in the insoluble component. After that, it is weighed, and the ratio of insoluble matter = insoluble matter weight / initial weight × 100 (%) is obtained.

In addition to the above, the UV-curable adhesive composition may further include an optional component such as an isocyanate group, an epoxy group, an aziridinyl group, an oxazoline group, or a carbodiimide group, which can react with the polar functional group of the polar group-containing monomer. A crosslinkable compound having a functional group, a tackifier, a plasticizer,
Various conventionally known additives such as softening agents, fillers, pigments, dyes and the like can be appropriately added within a range that does not impair the photopolymerizability.

The UV-curable adhesive composition has a viscosity adjusted by adding a viscosity increasing polymer or partially polymerizing a monomer component in order to adjust the viscosity of the adhesive composition to a level suitable for coating. It can be an enhanced monomer syrup.
When a partially polymerized monomer syrup having a polymerization rate of 10% is used as the ultraviolet curable adhesive composition, the polymerization rate of 10% is included in the polymerization rate in each step. For example,
When a partially polymerized monomer syrup having a polymerization rate of 10% is used, the polymerization rate after irradiation in the first step is 20% when the polymerization rate in the first step is substantially 10%.

In the present invention, the above-mentioned ultraviolet-curable adhesive composition is applied to a substrate and then irradiated with ultraviolet rays,
A pressure-sensitive adhesive sheet having an adhesive layer composed of a cured product of the ultraviolet-curable adhesive composition is produced.

As the base material, various base materials such as a synthetic resin film such as a polyester film used for a pressure-sensitive adhesive sheet or a fiber base material can be used. One or both surfaces of the base material can be used as an ultraviolet curable adhesive. By directly applying the composition and irradiating it with ultraviolet rays, adhesive sheets in the form of a sheet or tape can be obtained. The UV-curable adhesive composition coated on the base material can also be exposed to UV radiation by laminating a release paper. Further, release paper can be used as the base material, and the polymerized cured product once formed on the release paper by ultraviolet irradiation can be transferred to the adherend to be the pressure-sensitive adhesive sheet. The thickness of the adhesive layer at this time is arbitrary, but is generally 20 to 200.
It is about μm.

The ultraviolet irradiation is carried out by a first step of irradiating ultraviolet rays having an illuminance of 30 mW / cm ² or more, and then a second step of irradiating ultraviolet rays having an illuminance lower than that of the first step to substantially complete the polymerization reaction. Or light illuminance 30mW / c
m ² or more ultraviolet ray irradiation, then the second step to make the polymerization rate of the polymerized and cured product of the ultraviolet curable adhesive composition at least 70% by irradiation with ultraviolet light having a light intensity lower than that of the first step, and then the light intensity It is carried out by a method of performing a third step of irradiating ultraviolet rays of 30 mW / cm ² or more to substantially complete the polymerization reaction.

As an ultraviolet lamp used for ultraviolet irradiation, one having a spectral distribution in the wavelength range of 300 to 400 nm is used.
Black light (trade name of Toshiba Lighting & Technology Corporation),
Low pressure mercury lamp, high pressure mercury lamp, super high pressure mercury lamp,
Examples include metal halide lamps.

Of these, ultraviolet lamps such as a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, and a metal halide lamp are used for the ultraviolet irradiation in the first step and the third step, and for the ultraviolet irradiation in the second step. , Chemical lamps,
An ultraviolet lamp such as a black light is used. The illuminance of ultraviolet light in each step is set to a desired illuminance by adjusting the distance from the ultraviolet lamp to the ultraviolet irradiation target (ultraviolet curable adhesive composition) and the voltage. It should be noted that the ultraviolet irradiation in each step is performed in each of a plurality of stages, whereby the adhesive performance can be adjusted more precisely.

[0032]

EXAMPLES Examples and comparative examples of the present invention will be shown below.
Parts in each example mean parts by weight. The adhesive tape was evaluated by the following methods.

(I) Polymerization rate The weight (X ₁ g) of the sample whose polymerization rate is to be measured is weighed, dried in a dryer at 130 ° C. for 3 hours, and then weighed again (X ₂ g). Based on the weight of X ₁ g and X ₂ g, the polymerization rate was calculated as (X ₂ / X ₁ ) × 100 (%).

(II) Heat-resistant holding power A pressure-sensitive adhesive sheet adhered to a 25 μm polyethylene terephthalate film was used as a sample tape, which was adhered to a Bakelite plate so that the adhesive area was 10 mm wide and 20 mm long, and the temperature was 80 ° C. After being left for 30 minutes in a constant temperature, a shift distance (mm) after 1 hour when a load of 500 g was applied was measured.

(III) Adhesive strength A sample tape prepared by using a polyethylene terephthalate film having a thickness of 25 μm as a base material and cut into a width of 20 mm was prepared according to JIS Z-1522, and a stainless steel plate was used as an adherend. N / 20 mm) was measured.

(IV) Paste surface accuracy The unevenness and roughness of the adhesive surface were visually evaluated according to the following criteria. No unevenness or roughness: ○. There is unevenness and roughness: ×.

Example 1 0.12 parts of 2,2-dimethoxy-1,2-diphenylethan-1-one and 1-hydroxy-oxygen were added to a mixed monomer solution consisting of 95 parts of butyl acrylate and 5 parts of acrylic acid.
A solution containing 0.12 parts of cyclohexyl-phenyl-ketone was charged into a four-necked flask, and exposed to ultraviolet rays under a nitrogen atmosphere to partially photopolymerize (polymerization rate: 10%), thereby containing a prepolymer. A syrup (viscosity 30 poise) was obtained. To 100 parts of this partially polymerized syrup,
0.2 parts of trimethylolpropane triacrylate were uniformly mixed to prepare an ultraviolet curable adhesive composition.

This adhesive composition was applied to a polyethylene terephthalate film having a thickness of 25 μm, which had been subjected to a low-adhesion peeling treatment, so that the thickness after irradiation with light would be 50 μm. The mold-treated polyethylene terephthalate film was covered.

Metal halide lamp (80
W / cm) was used to irradiate ultraviolet light having a light illuminance of 70 mW / cm ² (measured with Topcon UVR-T1 having a peak sensitivity maximum wave of 350 nm) for 10 seconds (irradiation in the first step). Subsequently, a black light (15 W / cm) was used to irradiate ultraviolet rays having a light illuminance of 7 mW / cm ^{2 for} a necessary time until the polymerization rate reached 98% (irradiation in the second step). The heat-resistant holding power, adhesive strength, and surface accuracy of the obtained adhesive sheet were evaluated. Table 1 shows the total irradiation time and the evaluation results.

Comparative Example 1 In Example 1, the irradiation condition of ultraviolet rays was set to 7 mW of light irradiation by ultraviolet irradiation with a single illuminance using a black light.
An adhesive sheet was produced in the same manner as in Example 1 except that the ultraviolet ray of / cm ² was continuously irradiated. Moreover, the same evaluation as in Example 1 was performed. Table 1 shows the total irradiation time and the evaluation results.

Comparative Example 2 In Example 1, the ultraviolet irradiation conditions were the same as in Example 1 except that the ultraviolet irradiation with a single illuminance using a metal halide lamp was performed and the ultraviolet irradiation with the light illuminance of 70 mW / cm ² was continuously applied. To produce an adhesive sheet. Moreover, the same evaluation as in Example 1 was performed. Table 1 shows the total irradiation time and the evaluation results.

[0042]

[Table 1] From Table 1, in the method for producing the adhesive sheet of Example 1, the time until the completion of the polymerization is short, the productivity is good, the heat-resistant holding power,
It can be seen that the adhesive strength and adhesive surface accuracy are excellent. On the other hand, in the production method of Comparative Example 1 in which ultraviolet rays of low illuminance are continuously irradiated, it takes a long time to complete the polymerization, and it is recognized that the adhesive surface accuracy is also poor. In Comparative Example 2 in which ultraviolet rays with high illuminance were continuously irradiated, the time until the completion of the polymerization was short, but the high molecular weight was not sufficient, the cohesive force was lowered, and the heat resistance was poor.

Example 2 An adhesive sheet was produced in the same manner as in Example 1 except that the irradiation conditions of ultraviolet rays were changed as follows. Moreover, the same evaluation as in Example 1 was performed. Table 2 shows the total irradiation time and the evaluation results.

Irradiation in the first step: A metal halide lamp (80 W / cm) was used to irradiate ultraviolet rays having a light illuminance of 70 mW / cm ² for 4 seconds. Irradiation in the second step: Subsequently, black light (15 W / c
m) was used to irradiate ultraviolet rays having a light illuminance of 7 mW / cm ² for 60 seconds. The polymerization rate of the cured product at this stage is 90%
Met. Irradiation in the third step: Metal halide lamp (80W / c
m) was used to irradiate ultraviolet rays having a light illuminance of 70 mW / cm ^{2 for} a necessary time until the polymerization rate reached 98%.

Comparative Example 3 An adhesive sheet was produced in the same manner as in Example 1 except that the irradiation conditions of ultraviolet rays were changed as follows. Moreover, the same evaluation as in Example 1 was performed. Table 2 shows the total irradiation time and the evaluation results.

Irradiation in the first step: Black light (15 W
/ Cm) to generate 7 mW / cm ² of ultraviolet light.
Irradiate for 0 seconds. The polymerization rate of the cured product at this stage is 9
It was 0%. Irradiation in the second step: Next, metal halide lamp (80W
/ Cm) for 40 seconds until a polymerization rate of 98% was reached with ultraviolet light having an illuminance of 70 mW / cm ² .

[0047]

[Table 2] From Example 2 in Table 2, by performing the irradiation of the third step, the time until the completion of the polymerization is further shortened as compared with Example 1,
It is recognized that it is possible to produce an adhesive sheet having excellent adhesiveness while improving productivity. In Comparative Example 3, the UV irradiation is performed in two stages, but the adhesive surface accuracy is poor, and the adhesive strength is inferior to that of the Example.

Continued front page    F term (reference) 4J004 AA01 AA17 AB01 AB07 CA06                       CB01 CC02 DB02 EA05 GA01                       GA02

Claims (6)

[Claims] 1. A polymerization-cured product of the ultraviolet-curable adhesive composition is obtained by applying an ultraviolet-curable pressure-sensitive adhesive composition containing a vinyl-based monomer as a main component onto a substrate and then irradiating the ultraviolet-ray. In the method for producing a pressure-sensitive adhesive sheet having an adhesive layer, the ultraviolet irradiation step comprises first irradiation with ultraviolet light having an illuminance of 30 mW / cm ² or more, and then irradiation with ultraviolet light having a lower illuminance than the first step. A method for producing a pressure-sensitive adhesive sheet, which comprises a second step of completing a polymerization reaction. 2. A polymerization-cured product of the ultraviolet-curable adhesive composition is obtained by applying an ultraviolet-curable adhesive composition containing a vinyl-based monomer as a main component on a substrate and then irradiating with ultraviolet light. In the method for producing a pressure-sensitive adhesive sheet having an adhesive layer, the ultraviolet irradiation step comprises a first step of performing ultraviolet irradiation with a light illuminance of 30 mW / cm ² or more, and then an ultraviolet curing by an ultraviolet irradiation with a light illuminance lower than that of the first step. Step of increasing the polymerization rate of the polymerized and cured product of the water-based adhesive composition to at least 70%, and then the light intensity of 30
A process for producing a pressure-sensitive adhesive sheet, which comprises a third step of irradiating ultraviolet rays of mW / cm ² or more to substantially complete the polymerization reaction. 3. The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein the ultraviolet irradiation time in the first step is 20% or less of the total irradiation time of ultraviolet rays. 4. The illuminance of ultraviolet light in the second step is 30.
It is less than mW / cm < ² >, The Claims 1-3 characterized by the above-mentioned.
The method for producing a pressure-sensitive adhesive sheet according to any one of 1. 5. A pressure-sensitive adhesive sheet obtained by the production method according to claim 1. 6. A pressure-sensitive adhesive formed on a base material in a pressure-sensitive adhesive sheet obtained by the manufacturing method according to claim 1.