JP2001040066A - Ultraviolet-curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ultraviolet-curable composition capable of forming a cured coated film having excellent peelability from an adhesive substance and excellent adhesivity to various substrates by ultraviolet irradiation. SOLUTION: This ultraviolet curable composition comprises (a) a vinyl polymer containing an alicyclic epoxy group and a siloxane unit-containing group of the formula -(COO)a-A-SiR2O-[R2SiO]n-SiR2-A-(OOC)a- (A is a bifunctional hydrocarbon group or an alkyleneoxyalkylene group; R is a monofunctional hydrocarbon group containing no aliphatic unsaturated bond; (a) is 0 or 1; n is an integer of >=10) at the side chain, (b) an organosilicon compound containing one or more alicyclic epoxy groups in the molecule and (c) an onium salt-based photocuring catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet-curable composition, and more particularly, to crosslinking of a siloxane unit-containing vinyl polymer with an alicyclic epoxy group-containing organosilicon compound by ultraviolet irradiation in the presence of an onium salt photocuring catalyst. The present invention relates to an ultraviolet curable composition which reacts to form a cured film having excellent releasability from an adhesive substance.

[0002]

2. Description of the Related Art Conventionally, it has been difficult to use a silicone-based curable composition or a silicone / organic copolymer-based curable composition in order to impart releasability, water repellency and releasability to paper and various plastic surfaces. For example, when treating a substrate which is susceptible to heat with such a composition, a composition which is cured by irradiation with ultraviolet rays is applied. Examples of the ultraviolet-curable silicone composition include, for example, an ultraviolet-curable silicone composition comprising a hexenyl group-containing organopolysiloxane, a mercapto group-containing organopolysiloxane, an organopolysiloxane containing a hexenyl group and a mercapto group, and a photosensitizer. Release agents are known (see JP-A-6-16944). Examples of the UV-curable silicone / organic copolymer-based composition include epoxy monomers, silicone-based graft copolymers, and epoxy groups. An ultraviolet-curable silicone / organic copolymer-based release agent comprising an organopolysiloxane containing a polyether group and an onium salt-based curing catalyst has been proposed (see JP-A-4-323284). However, although a silicone-based release agent forms a cured film having excellent releasability with respect to an adhesive substance, there is a problem that adhesion to a substrate such as a polyester film is low. In addition, although the cured film of the silicone / organic copolymer release agent has excellent adhesion to the polyester film, a cured film having excellent release properties for adhesive substances such as silicone-based release agents cannot be obtained. There was a point. On the other hand, a curable composition containing a vinyl polymer containing an alicyclic epoxy group and a siloxane chain as a main component is also known (JP-A-8-269293,
JP-A-8-301954 and JP-A-9-16543
No. 6 and JP-A-10-140078). However, the vinyl polymer used in these compositions is obtained by reacting a silicone macromonomer having vinyl polymerization reactivity at one end of the molecular chain with an alicyclic epoxy group-containing vinyl polymerization reactive monomer, The composition using the vinyl polymer has a disadvantage that the curability may be insufficient.

[0003]

DISCLOSURE OF THE INVENTION The present inventors have made intensive studies to solve the above problems, and as a result, have reached the present invention. That is, an object of the present invention is to provide a UV-curable composition which forms a cured film having excellent releasability from an adhesive substance by irradiation with ultraviolet light, and further, the film has excellent adhesion to various substrates. is there.

[0004]

The present invention relates to (a) a vinyl polymer having an alicyclic epoxy group and a siloxane unit-containing group represented by the following general formula (I) in the side chain; : - (COO) aA-SiR 2 O- [R 2 SiO] n -SiR 2 -A -(OOC) a- (wherein, A is a divalent hydrocarbon group or an alkyleneoxyalkylene group, R is a monovalent hydrocarbon group containing no aliphatic unsaturated bond, and a is 0 or 1. , N is 10
Is an integer greater than or equal to. ), (B) an organosilicon compound containing at least one alicyclic epoxy group in the molecule, and (c)
The present invention relates to an ultraviolet curable composition comprising an onium salt-based photocuring catalyst.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION (a) Used in the composition of the present invention
The vinyl polymer of the component is a polymer having an alicyclic epoxy group and a siloxane unit-containing group represented by the following general formula (I) in a side chain. General formula (I): - (COO) aA-SiR 2 O- [R 2 SiO] n -SiR 2 -A -(OOC) a- In the above formula, A is a divalent hydrocarbon group or an alkyleneoxyalkylene group, and examples of the divalent hydrocarbon group include an ethylene group, a propylene group, a butylene group, and a hexylene group; Examples of the alkylene group include an ethyleneoxypropylene group. R is a monovalent hydrocarbon group not containing an aliphatic unsaturated bond, and is an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group; an aryl group such as a phenyl group, a tolyl group, and a xylyl group. Groups; aralkyl groups such as benzyl and phenethyl; a is 0 or 1; n is an integer of 10 or more, preferably in the range of 10 to 500, and particularly preferably in the range of 20 to 200. Examples of the alicyclic epoxy group include groups represented by the following formula.

Embedded image In the above formula, A, R and a are the same as described above. R ⁴ is a divalent or similar divalent hydrocarbon group, and includes a methylene group,
Examples thereof include an alkylene group such as an ethylene group, a propylene group, a butylene group, and a hexylene group; and an arylene group such as a phenylene group. m is an integer of 0 to 2, and k is an integer of 0 or more. The number average molecular weight of the vinyl polymer (a) is usually 500,000 or less,
Preferably in the range of 100 to 100,000,
More preferably, it is in the range of 000 to 50,000.

As the vinyl polymer of the component (a), a vinyl polymer represented by the following general formula is exemplified. General formula:

Embedded image In the above formula, A, R, n and a are the same as described above. R ¹ is a hydrogen atom or a monovalent hydrocarbon group containing no aliphatic unsaturated bond, and examples of the monovalent hydrocarbon group include the same groups as R. R ² is a hydrogen atom, a halogen atom, or the same or different monovalent organic group except for an alkenyl group, an acryloxy group, a methacryloxy group, an acrylamide group, and a methacrylamide group. As these monovalent organic groups,
For example, monovalent hydrocarbon groups such as aryl groups and cycloalkyl groups, cyano groups and formulas:

Embedded image And the group represented by In the above formula, R ³ is a hydrogen atom,
Alternatively, it is a monovalent organic group excluding an alkenyl group, an acryloxy group, and a methacryloxy group, and examples of the monovalent organic group include a monovalent hydrocarbon group and a carbinol group. This R
Specific examples of ³ include a group represented by the following formula.

Embedded image Since the curing rate of the composition of the present invention changes depending on the selection of R ² , for example, in applications where a faster curing rate is required, the use of R ² exhibiting basicity should be avoided. B is a group containing one or more alicyclic epoxy groups, for example, a group represented by the following formula.

Embedded image In the above formula, A, R, R ⁴ , m and k are the same as described above. x, y, z, x ', y' and z 'are x> 0, y
> 0, z ≧ 0, x ′> 0, y ′> 0, z ′ ≧ 0,
Preferably, (x + x ′) :( y + y ′) :( z +
z ′) is 0.01 to 20: 0.1 to 80: 0 to 99.8.
9, and more preferably (x +
x ′): (y + y ′): (z + z ′) is 0.05 to 1
0: 0.5 to 90: 0 to 99.45.

The vinyl polymer of the component (a) is, for example, (d) a general formula: Y- (COO) aA-SiR ₂ O- [R ₂ SiO
] _n -SiR ₂ -A -(OOC) a-Y (wherein Y is a vinyl polymerizable group, and A, R, a and n are the same as described above.)
And an alicyclic compound represented by (e) a general formula: Y- (COO) a-B (wherein, Y, a and B are the same as those described above). It is produced by polymerizing an epoxy group-containing vinyl polymerizable monomer and, if necessary, (f) a polymerizable vinyl monomer other than the components (d) and (e) under conditions that do not cause gelation.

The component (d) is an organopolysiloxane having a vinyl polymerizable group at both molecular chain terminals represented by the above general formula, and imparts properties derived from the polysiloxane chain to the cured film of the composition of the present invention. It is a component for. In the above formula, Y
Is a vinyl polymerizable group, and examples thereof include a vinyl group, an acryloxy group, a methacryloxy group, and a methacryloxyethyloxy group. Examples of the component (d) include a siloxane represented by the following formula.

Embedded image

The component (e) is a monomer represented by the above general formula and having a vinyl polymerizable group at one terminal and an alicyclic epoxy group at the other terminal. This component (e)
The component (a) is a component for controlling the content of the alicyclic epoxy group in the component, and examples thereof include a compound represented by the following formula.

Embedded image

The component (f) is a polymerizable vinyl monomer other than the components (d) and (e), and (d)
It is a component that can be copolymerized with the component and the component (e). The component (f) may be any one capable of vinyl polymerization, such as various esters of acrylic acid or methacrylic acid, ethylene or its derivatives, acrylic acid, methacrylic acid,
In addition to vinyl acetate, vinylidene chloride, vinyl chloride, and polyalkylene glycol monomethacrylate, compounds represented by the following formulas may be mentioned.

Embedded image In addition, this component can also use these in combination of 2 or more types.

The vinyl polymer of the component (a) is usually synthesized by radical copolymerization of the component (d), the component (e) and, if necessary, the component (f). In addition, conventionally known polymerization methods such as anionic polymerization and group transfer polymerization can be used.
The copolymerization ratio of the components (d) to (f) varies depending on the degree of polymerization of the polysiloxane of the component (d) and the type of the copolymerized monomer component, but the component (d): the component (e): the component (f)
0.1 to 40% by weight of components: 1 to 95% by weight: 0 to 9
It is preferably in the range of 8.9% by weight, more preferably 0.5 to 20% by weight: 5 to 70% by weight: 10 to 10% by weight.
It is in the range of 94.5% by weight. Since component (d) has vinyl polymerizable groups at both molecular chain terminals, gelation may occur during the reaction if the degree of polymerization of the polysiloxane is small or if the blending ratio during copolymerization is large. Therefore, in order to prevent gelation, it is desirable to increase the degree of polymerization of the polysiloxane of the component (d) or to reduce the amount of the component (d) used during copolymerization. In addition, even for a composition that may cause gelation, if the amount of the radical polymerization initiator is increased or the molecular weight of the reaction product is reduced by using a general chain transfer agent during radical polymerization, for example, In some cases, copolymerization can be performed without gelation. From these facts, the molecular weight of the reaction product obtained varies depending on the reaction conditions, so it cannot be said unconditionally. However, generally, gelation is prevented when the degree of polymerization of the polysiloxane (d) is 30 or less. Means that the content of the component (d) in the components (d) to (f) is 10
% Or less, and when the degree of polymerization of the polysiloxane (d) is 70 or more, the content is preferably 20% by weight or less. That is, generally, (d)
As the degree of polymerization of the component increases, the content of the component (d) in the component (a) can be increased. As chain transfer agents, benzene, toluene, diphenylmethane,
Benzene derivatives such as 2,4-diphenyl-4-methyl-1-pentene; chlorinated hydrocarbons such as chloroform and carbon tetrachloride; ketone compounds such as acetone and methyl ethyl ketone; alcohols such as n-butanol and isobutanol; Examples thereof include acetic acid, dioxane, dimethylacetamide, acetonitrile, triethylamine, and n-butylmercaptan. However, those containing a basic group are not preferred because they may capture cations generated from the onium salt-based photocuring catalyst of the component (c) upon irradiation with ultraviolet rays and delay curing. Usually, mercaptans such as n-butyl mercaptan have the largest chain transfer coefficient and are said to have high efficiency. Examples of the radical polymerization initiator used in the radical copolymerization include azo compounds such as azobisisobutyronitrile; benzoyl peroxide;
A peroxide such as dicumyl peroxide is exemplified. Examples of the polymerization method include a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, and a bulk polymerization method.
A solution polymerization method capable of uniformly dissolving the component (e) and the component (f) and polymerizing in a homogeneous system is preferable. The solvent used depends on the type and content of the component (f), but is generally an aromatic hydrocarbon such as benzene, toluene or xylene; a ketone such as methyl ethyl ketone or methyl isobutyl ketone; an ester such as ethyl acetate or butyl acetate. And ethers such as tetrahydrofuran, dioxane and diethyl ether. Further, two or more of these solvents may be used in combination. After the completion of the copolymerization reaction, low-boiling substances such as a solvent are removed by a method such as distillation under reduced pressure by heating to obtain a vinyl polymer as the component (a).

The organosilicon compound having at least one alicyclic epoxy group in the molecule of the component (b) used in the composition of the present invention reacts with the alicyclic epoxy group in the component (a). Is a component that acts as a crosslinking agent for curing the composition of the present invention. As the organosilicon compound as the component (b), various conventionally known compounds having one or more alicyclic epoxy groups in one molecule can be used.
It is preferably an organopolysiloxane having a plurality of alicyclic epoxy groups in the molecule. Such an organopolysiloxane may have a linear, branched or cyclic molecular structure and a number average molecular weight of several tens to
Hundreds of thousands of wide ranges can be used. Specifically, an organopolysiloxane represented by the following formula is exemplified.

Embedded image The amount of the component (b) is usually in the range of 1 to 100,000 parts by weight, and preferably in the range of 10 to 10,000, based on 100 parts by weight of the component (a).

The component (c) used in the composition of the present invention
Ni-based photocuring catalyst accelerates ring-opening reaction of epoxy group
A known onium salt can be used. example
If the formula: ArN_Two ⁺Z^-Wherein Ar is an aryl group
And Z is BF_Four, PF₆, AsF₆ , SbF₆, SbC
l₆, HSO_Four, ClO_FourNon-basic and non-nucleophilic like
Is an anion. A) a diazonium salt of the formula:
R^Three _TwoI⁺Z^-(Where R^ThreeAnd Z are the same as above.
The iodonium salt shown by these is mentioned. This (c)
Amount of the component (a) and the reactivity of the component (b)
It can be increased or decreased as appropriate depending on the desired curing speed,
Based on 100 parts by weight of the total of the components (a) and (b)
Preferably in the range of 0.1 to 20 parts by weight,
More preferably, it is in the range of 1 to 10 parts by weight. this
If the amount is less than 0.1 part by weight, the composition of the present invention is cured.
When the content exceeds 20 parts by weight, the cured film is separated.
This is because moldability and peelability may be reduced.

The composition of the present invention comprises the components (a) to (c) described above.
It is obtained by uniformly mixing a predetermined amount of the components,
If necessary, an inorganic filler such as silica, a pigment,
An organic solvent or the like may be added and blended.

The ultraviolet curable composition of the present invention as described above uses a pre-crosslinked vinyl polymer in which the main chain is crosslinked by siloxane units as component (a), so that it has excellent curability. In addition, the surface of the obtained cured product can be arbitrarily imparted with properties such as releasability, releasability, water repellency, low surface tension, and low friction derived from the siloxane chain. In addition, since the alicyclic epoxy group-containing organosilicon compound of the component (b) is blended, the composition of the present invention has excellent curability by ultraviolet irradiation, and the obtained cured film has good adhesion to a substrate. Is excellent. Further, the composition of the present invention has an advantage that it can be used as a solventless type by using a low-viscosity organosilicon compound as the component (b). That is, if the low-viscosity component (b) having a viscosity of about 1 to 5,000 mPa · s is used as the reactive diluent, the viscosity that can be applied to various substrates without dilution with an organic solvent (usually, 20, 000 mPa · s or less), resulting in an advantage that the composition can be applied to a substrate having poor solvent resistance. From these facts, the ultraviolet-curable composition of the present invention is useful as a coating agent for a sheet-like base material such as paper, film, metal foil, etc., which is required to be peelable from an adhesive substance. In addition, the amount of the composition of the present invention applied to various substrates is not limited depending on the type of the substrate, but generally, when the composition of the present invention is used as a solvent, the composition of the present invention is 0.1 to 0.1%. 1.0 g / m ²
When the composition of the present invention is used as a solventless type, the composition of the present invention is 1.0 to 2.0 g /
m ² .

[0016]

The present invention will be described below in detail with reference to examples. In the examples, the viscosity is a value measured at 25 ° C.
e represents a methyl group. The number average molecular weight of the obtained vinyl polymer was a value measured by gel permeation chromatography (GPC) in terms of standard polystyrene. Further, the curability of the ultraviolet curable composition and the peel resistance value and the residual adhesiveness of the obtained cured film were measured according to the following methods. -Curability The ultraviolet curable composition was applied to the polyethylene surface of polyethylene laminated paper and cured, and the resulting cured film was rubbed with a finger to measure the curability. If the film is formed and the surface of the film is not cloudy even when rubbed with a finger,
The case where the film was formed but the surface of the film became cloudy when rubbed strongly was evaluated as Δ, and the case where the film was not formed was evaluated as ×. ○ Peeling resistance value A cured film obtained by applying and curing the ultraviolet curable composition on the polyethylene surface of polyethylene laminated paper,
An acrylic pressure-sensitive adhesive (manufactured by Toyo Ink Manufacturing Co., Ltd., trade name: Olivine BPS5127) is applied, and
PET film (made by Ushigome Slitter Co., Ltd., trade name:
(Mirror, thickness: 25 μm) was compressed by reciprocating a 2 kg tape roller. This was cut into a width of 5.0 cm to obtain a test piece. This test piece was subjected to 20 g / cm at room temperature.
^The test piece for measurement was prepared by being left for 24 hours with the load of ² applied. A PET film was obtained from this test piece,
The film was peeled off at a speed of 300 mm / min and an angle of 180 ° using Tensilon, and the force (g) required at that time was measured. ○ Residual adhesion rate (adhesion to substrate) The cured film obtained by applying and curing the ultraviolet curable composition on the polyethylene surface of polyethylene laminated paper,
A commercially available pressure-sensitive adhesive tape having a width of 38 mm [trade name: 31B, manufactured by Nitto Denko Corporation] is pressure-bonded by reciprocating a 2 kg tape roller, and then 20 g / cm ² on the pressure-sensitive adhesive tape.
Under a load of 20 ° C. for 20 hours.
After releasing the load, the adhesive tape was peeled off at an angle of 180 degrees. Further, the pressure-sensitive adhesive tape was pressed against the polyethylene surface of the polyethylene laminated paper by reciprocating a 2 kg tape roller, and allowed to stand at room temperature for 30 minutes with a load of 20 g / cm ² applied thereto. After standing, the load was released again, and the pressure-sensitive adhesive tape was peeled at a speed of 3 using Tensilon.
The film was peeled off at an angle of 180 degrees at 00 mm / min, and the peel resistance was measured. This was defined as the residual adhesive strength. In addition, the above-mentioned blank was used except that a Teflon sheet (trade name: Naflon tape TOMBO9001 manufactured by Nichias Corporation) was used as a blank in place of the cured film of the ultraviolet-curable composition formed on the polyethylene surface of the polyethylene laminated paper. The peel resistance was measured in the same manner as described above, and this was used as the basic adhesive strength. These adhesive forces were substituted into the following equation to determine the residual adhesive ratio. Residual adhesion rate (%) = (Residual adhesive strength / Basic adhesive strength) × 10
0

[0017]

Reference Example 1 15 g of toluene was charged into a 100 ml flask equipped with a stirrer, a thermometer, a cooling tube, and a nitrogen gas inlet tube, and then nitrogen gas was bubbled for 30 minutes to remove dissolved oxygen. 8.5 g of butyl acrylate
(66.3 mmol), formula:

Embedded image 1 g of an alicyclic epoxy group-containing vinyl polymerizable monomer represented by the following formula (manufactured by Daicel Chemical Industries, Ltd., trade name: A200)
(5.5 mmol), average composition formula:

Embedded image And 0.5 g (0.0464 mmol) of vinyl polymerizable dimethylpolysiloxane at both ends and 0.1 g of azobisisobutyronitrile were charged, and nitrogen gas was bubbled for 30 minutes. The reaction mixture is placed under a nitrogen atmosphere,
After heating and stirring at 00 ° C. for 3 hours, 0.1 g of azobisisobutyronitrile was added, and 10 g was further added under a nitrogen atmosphere.
The mixture was heated and stirred at 0 ° C. for 3 hours. When the toluene solution obtained here was analyzed by GPC, it was found that the peaks of the raw materials butyl acrylate, the alicyclic epoxy group-containing vinyl polymerizable monomer, and the vinyl polymerizable dimethyl polysiloxane at both ends were almost disappeared. found. Therefore, low-boiling substances were removed from the obtained reaction solution by heating under reduced pressure to obtain 9.9 g of a semi-solid polymer. This is NMR
Analysis revealed that the obtained reaction product was a vinyl polymer having an alicyclic epoxy group and a siloxane unit-containing group represented by the following average composition formula. The number average molecular weight of this vinyl polymer was 12,000.

Embedded image (x + x ′) :( y + y ′) :( z + z ′) = 0.07: 7.
73: 92.2

[0018]

REFERENCE EXAMPLE 2 15 g of toluene was charged into a 100 ml flask equipped with a stirrer, thermometer, cooling tube and nitrogen gas inlet tube, and then nitrogen gas was bubbled for 30 minutes to remove dissolved oxygen. To this, 6.1 g of butyl acrylate
(47.6 mmol), formula:

Embedded image Alicyclic epoxy group-containing vinyl polymerizable monomer represented by the formula (manufactured by Daicel Chemical Industries, Ltd., trade name: A200) 3.4
g (8.9 mmol), average composition formula:

Embedded image , 0.5 g (0.09 mmol) of a vinyl polymerizable dimethylpolysiloxane at both ends, α-methylstyrene dimer (trade name: AMSD, manufactured by Goi Chemical Co., Ltd.)
1 g and 0.1 g of azobisisobutyronitrile were charged, and nitrogen gas was bubbled for 30 minutes. The reaction mixture was heated and stirred at 100 ° C. for 3 hours under a nitrogen atmosphere, and then 0.1 g of azobisisobutyronitrile was added.
Further, the mixture was heated and stirred at 100 ° C. for 3 hours under a nitrogen atmosphere.
When the toluene solution obtained here was analyzed by GPC, it was found that the peaks of the raw materials butyl acrylate, the alicyclic epoxy group-containing vinyl polymerizable monomer, and the vinyl polymerizable dimethyl polysiloxane at both ends were almost disappeared. found. For this reason, low-boiling substances are removed from the obtained reaction solution by heating under reduced pressure to obtain a semi-solid polymer 9.8.
g was obtained. NMR analysis revealed that the obtained reaction product was a vinyl polymer having an alicyclic epoxy group and a siloxane unit-containing group represented by the following average composition formula. The number average molecular weight of this vinyl polymer was 11,500.

Embedded image (x + x ′) :( y + y ′) :( z + z ′) = 0.16: 1
5.88: 83.96

[0019]

REFERENCE EXAMPLE 3 15 g of toluene was charged into a 100 ml flask equipped with a stirrer, thermometer, cooling tube and nitrogen gas inlet tube, and then nitrogen gas was bubbled for 30 minutes to remove dissolved oxygen. To this, 6.0 g of butyl acrylate
(46.8 mmol), formula:

Embedded image Alicyclic epoxy group-containing vinyl polymerizable monomer represented by Formula (manufactured by Daicel Chemical Industries, Ltd., trade name: A200) 3.0
g (16.5 mmol), average composition formula:

Embedded image 1.0 g (0.18 mmol) of a vinyl polymerizable dimethylpolysiloxane at both ends represented by, 0.1 of α-methylstyrene dimer (Goi Chemical Industry Co., Ltd., trade name: AMSD) 0.1
g and azobisisobutyronitrile were charged, and nitrogen gas was bubbled for 30 minutes. This reaction mixture was heated and stirred at 100 ° C. for 3 hours under a nitrogen atmosphere.
0.1 g of azobisisobutyronitrile was added, and the mixture was further heated and stirred at 100 ° C. for 3 hours under a nitrogen atmosphere. When the toluene solution obtained here was analyzed by GPC, it was found that the peaks of the raw materials butyl acrylate, the alicyclic epoxy group-containing vinyl polymerizable monomer, and the vinyl polymerizable dimethyl polysiloxane at both ends were almost disappeared. found. For this reason, low-boiling substances were removed from the obtained reaction solution by heating under reduced pressure, and 9.9 g of a semi-solid polymer was removed.
I got NMR analysis revealed that the obtained reaction product was a vinyl polymer having an alicyclic epoxy group and a siloxane unit-containing group represented by the following average composition formula. The number average molecular weight of this vinyl polymer was 11,300.

Embedded image (x + x '): (y + y'): (z + z ') = 0.30: 2
7.7: 72.0

[0020]

Reference Example 4 15 g of toluene was charged into a 100 ml flask equipped with a stirrer, a thermometer, a cooling tube, and a nitrogen gas inlet tube, and then nitrogen gas was bubbled for 30 minutes to remove dissolved oxygen. To this, 6.0 g of butyl acrylate
(46.8 mmol), 3.5 g (9.1 mmol) of 1- (3 ′, 4′-epoxycyclohexyl) ethyl-3-methacryloxypropyl-tetramethyldisiloxane,
Average composition formula:

Embedded image And 0.5 g (0.09 mmol) of vinyl polymerizable dimethylpolysiloxane at both ends and 0.1 g of azobisisobutyronitrile were charged, and nitrogen gas was bubbled for 30 minutes. The reaction mixture is placed under a nitrogen atmosphere at 100
After heating and stirring at 3 ° C. for 3 hours, 0.1 g of azobisisobutyronitrile was added, and the mixture was further heated at 100 ° C. under a nitrogen atmosphere.
For 3 hours. When the toluene solution obtained here was analyzed by GPC, it was found that butyl acrylate, 1- (3 ′, 4′-epoxycyclohexyl) ethyl-3-methacryloxypropyl-tetramethyldisiloxane and vinyl polymerization at both ends were used as raw materials. It was found that the peak of the hydrophobic dimethylpolysiloxane almost disappeared. Therefore, low-boiling substances were removed from the obtained reaction solution by heating under reduced pressure to obtain 9.8 g of a semi-solid polymer. This is N
MR analysis revealed that the obtained reaction product was a vinyl polymer having an alicyclic epoxy group and a siloxane unit-containing group represented by the following average composition formula. The number average molecular weight of this vinyl polymer is 20,333.
Met.

Embedded image (x + x ′) :( y + y ′) :( z + z ′) = 0.15: 1
4.50: 85.35

[0021]

REFERENCE EXAMPLE 5 15 g of toluene was charged into a 100 ml flask equipped with a stirrer, thermometer, cooling tube and nitrogen gas inlet tube, and then nitrogen gas was bubbled for 30 minutes to remove dissolved oxygen. To this, 5.0 g of butyl acrylate
(39.0 mmol), formula:

Embedded image Alicyclic epoxy group-containing vinyl polymerizable monomer represented by the formula (manufactured by Daicel Chemical Industries, Ltd., trade name: A200) 5.0
g (27.4 mmol) and 0.2 g of azobisisobutyronitrile were added, and nitrogen gas was bubbled for 30 minutes. The reaction mixture is heated at 60 ° C. under a nitrogen atmosphere.
After 24 hours of heating and stirring at, analysis by GPC revealed that the peaks of the starting materials butyl acrylate and the alicyclic epoxy group-containing vinyl polymerizable monomer had almost disappeared. Therefore, low-boiling substances were removed from the obtained reaction solution by heating under reduced pressure to obtain 10.0 g of a semi-solid polymer. NMR analysis revealed that the resulting reaction product was an alicyclic epoxy group-containing vinyl polymer represented by the following average composition formula.
The number average molecular weight of this vinyl polymer was 44,000.

Embedded image y: z = 41: 59

[0022]

Reference Example 6 15 g of toluene was charged into a 100 ml flask equipped with a stirrer, a thermometer, a cooling tube, and a nitrogen gas inlet tube, and then nitrogen gas was bubbled for 30 minutes to remove dissolved oxygen. To this, 6.0 g of butyl acrylate
(46.8 mmol), formula:

Embedded image Alicyclic epoxy group-containing vinyl polymerizable monomer represented by Formula (manufactured by Daicel Chemical Industries, Ltd., trade name: A200) 3.0
g (16.5 mmol), average composition formula:

Embedded image , 1.0 g (0.14 mmol) of vinyl polymerizable dimethylpolysiloxane at one end and α-methylstyrene dimer (Goi Chemical Industry Co., Ltd., trade name: AMSD) 0.1
g and azobisisobutyronitrile were charged, and nitrogen gas was bubbled for 30 minutes. This reaction mixture was heated and stirred at 100 ° C. for 3 hours under a nitrogen atmosphere.
0.1 g of azobisisobutyronitrile was added, and the mixture was further heated and stirred at 100 ° C. for 3 hours under a nitrogen atmosphere. When the toluene solution obtained here was analyzed by GPC, it was found that the peaks of the raw materials butyl acrylate, alicyclic epoxy group-containing vinyl polymerizable monomer, and vinyl polymerizable dimethylpolysiloxane at one end were almost disappeared. found. Therefore, low-boiling substances were removed from the obtained reaction solution by heating under reduced pressure, and 9.8 g of a semi-solid polymer was removed.
I got NMR analysis revealed that the obtained reaction product was a vinyl polymer represented by the following average composition formula and having an alicyclic epoxy group and a siloxane chain grafted to a side chain. The number average molecular weight of this vinyl polymer was 10,320.

Embedded image x: y: z = 0.22: 25.78: 74.0

[0023]

Example 1 An average composition formula was added to 20 parts by weight of the vinyl polymer synthesized in Reference Example 1.

Embedded image 80 parts by weight of an alicyclic epoxy group-containing organopolysiloxane (viscosity: 360 mPa · s) and an onium salt-based photocuring catalyst (manufactured by General Electric Co., trade name:
(UV9380C) 2 parts by weight were added and mixed uniformly to prepare a solventless ultraviolet curable composition having a viscosity of 2,000 mPa · s. The obtained composition was applied to the polyethylene surface of polyethylene-laminated paper using a bar coater so that the coating amount of the solid content was 1.0 g / m ² . After coating, it was left in an oven at 50 ° C. for 30 seconds. Then, the coated surface was irradiated with ultraviolet rays using an ultraviolet irradiation device equipped with a high-pressure mercury lamp (irradiation amount 260
mj / cm ² ) to form a cured film. The curability, peel resistance and residual adhesion of the cured film thus obtained were measured. The results are shown in Table 1.

[0024]

Example 2 An average composition formula was added to 40 parts by weight of the vinyl polymer synthesized in Reference Example 2.

Embedded image And 60 parts by weight of an alicyclic epoxy group-containing organopolysiloxane (viscosity: 360 mPa · s) and an onium salt-based photocuring catalyst (manufactured by General Electric Co., trade name:
UV9380C) (2 parts by weight) was added and mixed uniformly to prepare a solvent-free ultraviolet curable composition having a viscosity of 800 mPa · s. The obtained composition was applied to the polyethylene surface of polyethylene-laminated paper using a bar coater so that the coating amount of the solid content was 1.0 g / m ² . After coating, it was left in an oven at 50 ° C. for 30 seconds. Next, the coated surface was irradiated with ultraviolet rays using an ultraviolet irradiation device equipped with a high-pressure mercury lamp (irradiation amount 260 m
j / cm ² ) to form a cured film. The curability, peel resistance and residual adhesion of the cured film thus obtained were measured. The results are shown in Table 1.

[0025]

Example 3 An average composition formula was added to 50 parts by weight of the vinyl polymer synthesized in Reference Example 3.

Embedded image Are added and 2 parts by weight of an onium salt-based photocuring catalyst (trade name: UV9380C, manufactured by General Electric Co., Ltd.) are added, and these are uniformly mixed to cure with ultraviolet light. A composition was prepared. The obtained composition was dissolved in n-hexane so that the solid content concentration was 8% by weight, and this solution was coated on a polyethylene surface of polyethylene laminated paper using a bar coater so that the solid content was 0.5 g. / M ² . After coating, it was left in an oven at 70 ° C. for 30 seconds. Then, the coated surface was irradiated with ultraviolet rays using an ultraviolet irradiation device equipped with a high-pressure mercury lamp (irradiation amount 26
0 mj / cm ² ) to form a cured film. The curability, peel resistance and residual adhesion of the cured film thus obtained were measured. The results are shown in Table 1.

[0026]

Example 4 An average composition formula was added to 30 parts by weight of the vinyl polymer synthesized in Reference Example 4.

Embedded image And 70 parts by weight of an alicyclic epoxy group-containing organopolysiloxane (viscosity: 360 mPa · s) and an onium salt-based photocuring catalyst (manufactured by General Electric Co., trade name:
(UV9380C) 2 parts by weight were added and mixed uniformly to prepare a solventless ultraviolet curable composition having a viscosity of 3,500 mPa · s. The obtained composition was applied to the polyethylene surface of polyethylene-laminated paper using a bar coater so that the coating amount of the solid content was 1.0 g / m ² . After coating, it was left in an oven at 50 ° C. for 30 seconds. Then, the coated surface was irradiated with ultraviolet rays using an ultraviolet irradiation device equipped with a high-pressure mercury lamp (irradiation amount 260
mj / cm ² ) to form a cured film. The curability, peel resistance and residual adhesion of the cured film thus obtained were measured. The results are shown in Table 1.

[0027]

Comparative Example 1 An average composition formula was added to 50 parts by weight of the vinyl polymer synthesized in Reference Example 2.

Embedded image And 50 parts by weight of a glycidoxypropyl group-containing organopolysiloxane and an onium salt-based photocuring catalyst (manufactured by General Electric Co., trade name: UV9380C) 2
Parts by weight and uniformly mixed to give a viscosity of 600
A solvent-free composition of mPa · s was prepared. The obtained composition was applied to the polyethylene surface of polyethylene laminated paper in the same manner as in Example 1 and irradiated with ultraviolet rays, but no cured film was formed.

[0028]

Comparative Example 2 An average composition formula was added to 70 parts by weight of the vinyl polymer synthesized in Reference Example 5.

Embedded image Were added and 2 parts by weight of an onium salt-based photocuring catalyst (manufactured by General Electric Co., trade name: UV9380C) were added and mixed. The components were not uniformly mixed. A heterogeneous composition was obtained. This composition was applied to the polyethylene surface of polyethylene-laminated paper in the same manner as in Example 1 and irradiated with ultraviolet rays. However, the composition was not cured because the composition was non-uniform, and no film was formed.

[0029]

Comparative Example 3 An average composition formula was added to 40 parts by weight of the vinyl polymer synthesized in Reference Example 6.

Embedded image Are added and 2 parts by weight of an onium salt-based photo-curing catalyst (trade name: UV9380C, manufactured by General Electric Co., Ltd.) are added, and these are uniformly mixed and cured by ultraviolet light. A composition was prepared. The obtained composition was dissolved in n-hexane so that the solid content concentration became 8% by weight, and this solution was used to form a cured film in the same manner as in Example 3. The resulting cured film had low physical strength due to insufficient curing, and the surface of the film became cloudy when strongly rubbed with a finger. For this reason, the peel resistance value and the residual adhesive force could not be measured.

[0030]

Comparative Example 4 In Example 1, no vinyl polymer was blended, and the average composition formula was:

Embedded image The solvent-free ultraviolet curable composition having a viscosity of 360 mPa · s was prepared in the same manner as in Example 1 except that the amount of the alicyclic epoxy group-containing organopolysiloxane represented by the formula was changed to 100 parts by weight. This composition was used to form a cured film in the same manner as in Example 1, and its curability and peel resistance were measured. Further, when the residual adhesive force was measured, there was a portion where the pressure-sensitive adhesive tape and the substrate were firmly adhered and did not peel off, and the residual adhesive ratio could not be measured. The results are shown in Table 1.

[0031]

[Table 1]

[0032]

The ultraviolet-curable composition of the present invention comprises the components (a) to (c), in particular, a specific vinyl polymer of the component (a) and an alicyclic epoxy group-containing organic compound of the component (b). Since it is used in combination with a silicon compound, it shows excellent curability when crosslinked by irradiation with ultraviolet light. Further, the obtained cured film has characteristics that it has excellent releasability to an adhesive substance and excellent adhesion to various substrates. Further, by using the component (b) having a low viscosity, it has a feature that it can be used as a solventless curable composition.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J036 AB07 AB20 AJ21 AK17 EA04 FA05 FA11 GA01 GA02 GA03 GA04 GA24 HA02 JA01

Claims (3)

[Claims] 1. (a) A vinyl polymer having an alicyclic epoxy group and a siloxane unit-containing group represented by the following general formula (I) in a side chain: General formula (I):-(COO) aA-SiR ₂ O- [R ₂ SiO] _n -SiR ₂ -A -(OOC) a- (wherein, A is a divalent hydrocarbon group or an alkyleneoxyalkylene group, R is a monovalent hydrocarbon group containing no aliphatic unsaturated bond, and a is 0 or 1. , N is 10
Is an integer greater than or equal to. ), (B) an organosilicon compound containing at least one alicyclic epoxy group in the molecule, and (c)
An ultraviolet curable composition comprising an onium salt-based photocuring catalyst. 2. The ultraviolet curable composition according to claim 1, wherein the component (b) is an organopolysiloxane containing at least one alicyclic epoxy group in a molecule. 3. The ultraviolet-curable composition according to claim 1, which is used for forming a peelable cured film.