JP3384268B2 - Epoxy-containing organopolysiloxane, method for producing the same, and ultraviolet-curable composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an epoxy group-containing organopolysiloxane which is excellent in releasability and slipperiness with respect to an adhesive substance and does not show a decrease in adhesive force of an adhesive layer, a method for producing the same, and an ultraviolet curable composition. Regarding

[0002]

BACKGROUND OF THE INVENTION For the purpose of preventing adhesion or sticking between a pressure sensitive adhesive substance and a substrate such as paper, processed paper or plastic film, heat or heat is applied to the substrate surface. A cured film of an ultraviolet or electron beam curable silicone composition has been formed, and this is generally called release paper.

A composition for forming a releasable cured film is required to be cured at a low temperature in a short time in order to improve productivity and save energy and also to be applied to a substrate having poor heat resistance. In particular, in order to prevent the base material from being deformed by heat, it is advantageous to form a cured film on the base material by irradiating it with ultraviolet rays.

As a useful method for producing a composition for forming a peelable cured film, there is a method in which a composition comprising an organopolysiloxane having an epoxy group-containing organic group and an onium salt photoinitiator is cured by irradiation with ultraviolet rays. However, the releasability and slipperiness of the cured film with respect to the adhesive substance depend on the epoxy group content of the organopolysiloxane having an epoxy group-containing organic group, and the greater the epoxy group content, the heavier the peeling force of the cured film. And the slipperiness decreases.

As a conventional technique, an organopolysiloxane having a trifunctional siloxane unit and an epoxy group has been disclosed (JP-A-2-283858). This is 1,
(HMe ₂ SiO _1/2 ) ₅ (MeSiO _3/2 ) ₃ was synthesized from 1,3,3-tetramethyldisiloxane and methyltrimethoxysilane, and ₃ was obtained by equilibration reaction of this with octamethylcyclotetrasiloxane. The organohydropolysiloxane having a functional siloxane unit and a SiH group is used, and the desired product is obtained by an addition reaction of the organohydropolysiloxane with a compound having an epoxy group and an alkenyl group. In this example, in order to improve curability, An organopolysiloxane having a trifunctional siloxane unit is used for the production of release paper because the surface of the cured film does not have slipperiness because the epoxy group-containing organic group is delocalized in one molecule. At times, it was inferior in workability such as winding and attaching tape.

Japanese Unexamined Patent Publication No. 7-242828 discloses an example in which a non-reactive organopolysiloxane is used together with an organopolysiloxane having an epoxy group-containing organic group and a photoinitiator. In this example, since the non-reactive organopolysiloxane is used, the slip property is improved, but the non-reactive organopolysiloxane migrates from the surface of the cured film to the surface in contact with it, and the residual adhesion ratio, that is, the pressure-sensitive adhesive There is a problem that the adhesive strength of the layer is reduced.

Further, in JP-A-7-216308, for the purpose of improving curability, a vinyl-functional silicone and a hydrogen-functional silicone are reacted in advance, and then this is reacted with an olefin epoxy compound. A light-peeling UV-curable epoxy silicone composition containing the above pre-crosslinked epoxy silicone is disclosed. ≡SiCH ₂ CH ₂ Si≡ formed by this reaction is disclosed.
Bonding was not always favorable for light release.

The present invention has been made in view of the above circumstances, and provides a photocationically curable type epoxy group-containing organopolysiloxane having excellent slipperiness and residual adhesiveness with light peeling, a method for producing the same, and an ultraviolet ray curable composition. The purpose is to do.

[0009]

Means for Solving the Problems and Modes for Carrying Out the Invention As a result of intensive studies to achieve the above-mentioned objects, the present inventors have found that the following general formula (5) in which both ends of the molecular chain are blocked with hydroxyl groups: A first step of dehydrogenatively condensing the organopolysiloxane represented by and the organohydropolysiloxane represented by the following general formulas (6) and / or (7) under a platinum catalyst, and SiH groups remaining in the reaction product. From the second step in which the epoxy group and the alkenyl group in the alkenyl compound are subjected to an addition reaction, the epoxy group-containing organopolysiloxane represented by the following general formulas (1) to (4) and (4 ′) can be obtained, and further the above-mentioned epoxy group-containing organopolysiloxane, in order to have O (R ₂ SiO) organopolysiloxane chain of the epoxy group-free represented by _n, it therefrom and an onium salt photoinitiator Cured film of the ultraviolet curable composition, releasability, excellent sliding property, and found that keeping the residual adhesion ratio well, the present invention has been accomplished.

Therefore, the present invention provides the following general formula (1),
Provided is an epoxy group-containing organopolysiloxane represented by (2), (3), (4) or (4 ').

[0011]

[Chemical 3] (In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, p and r are integers of 2 or more, q and s are integers of 0 or more, and n is an integer of 2 or more, E represents an epoxy group-containing organic group.)

The present invention also provides the following general formula (5) HO (R ₂ SiO) _n H (5) (wherein R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, n Is an integer of 2 or more.) The hydroxyl groups of the organopolysiloxane having both ends of the molecular chain blocked with hydroxyl groups and Si of the organohydropolysiloxane represented by the following general formula (6) and / or (7)
First step of dehydrogenative condensation with H group in the presence of platinum catalyst, and addition reaction of alkenyl group of epoxy group and alkenyl group-containing compound with residual SiH group in the reaction product obtained in the first step. A method for producing an epoxy group-containing organopolysiloxane, which comprises a second step,
Furthermore, there is provided an ultraviolet-curable composition comprising the above-mentioned organopolysiloxane having an epoxy group and an onium salt photoinitiator.

[0013]

[Chemical 4] (In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, a is 0 or 1, p and r are integers of 2 or more,
q and s are integers of 0 or more. )

The present invention will be described in more detail below.
The epoxy group-containing organopolysiloxane of the present invention is produced by using, as a raw material, an organopolysiloxane having a hydroxyl group at both terminals, an organohydropolysiloxane, and an epoxy group- and alkenyl group-containing compound.

Organopolysiloxane having OH groups at both ends
As the sun, use the one represented by the following general formula (5).
can do.         HO (R₂SiO )_nH (5)

R is a methyl group, an ethyl group, a propyl group,
An alkyl group such as a butyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group and a tolyl group, or a part or all of the hydrogen atoms bonded to the carbon atoms of these groups are a hydroxy group or a cyano group. A substituted or unsubstituted monovalent hydrocarbon having 1 to 10 carbon atoms selected from a hydroxypropyl group substituted with a halogen atom, a cyanoethyl group, a 1-chloropropyl group, a 3,3,3-trifluoropropyl group, and the like. Indicates a group. In this case, R is preferably an alkyl group or an aryl group from the viewpoint of the releasability of the cured product of the epoxy group-containing organopolysiloxane of the present invention. Further, it is desirable that 80 mol% or more of the R groups of all siloxane units are methyl groups.
n is an integer of 2 or more, and 2 of this organopolysiloxane
It is preferable that the viscosity at 5 ° C. is 1 to 1,000,000 cP, particularly 50 to 50,000 cP. The compound of formula (5) may be a single compound or a mixture of two or more compounds.

Specific examples include the following.
Me represents a methyl group and Ph represents a phenyl group (the same applies hereinafter). HO (Me ₂ SiO) ₅₀ H HO (Me ₂ SiO) ₃₀₀ H HO (Me ₂ SiO) ₆₀₀ H HO (Me ₂ SiO) ₃₀₀ (Ph ₂ SiO) ₃₀ H

As the organohydropolysiloxane, those represented by the following general formulas (6) and / or (7) can be used.

[0019]

[Chemical 5]

R has the same meaning as described above, a is 0 or 1, p and r are integers of 2 or more, q and s are integers of 0 or more,
The organohydropolysiloxane has a viscosity at 25 ° C. of 1 to 50,000 cP, preferably 10 to 10,000.
It is a number that becomes cP. 2-10 of all siloxane units
It is preferable that 0 mol%, particularly 2 to 70 mol%, are HRSiO units. The above organohydropolysiloxane may be a mixture of two or more kinds, or may be used alone.

Specific examples include the following.

[0022]

[Chemical 6]

The epoxy group- and alkenyl group-containing compound is an organic compound having at least one epoxy group and at least one alkenyl group in one molecule. in this case,
The epoxy group can be provided as an epoxy group-containing organic group of the formulas (i) to (iv) described later. Examples of the alkenyl group include those having 2 to 8 carbon atoms such as vinyl group, allyl group, propenyl group and butenyl group. Examples thereof include 4-vinylcyclohexene oxide, 4-isopropenyl-1-methylcyclohexene oxide, allyl glycidyl ether, 1,5-hexadiene monoxide, and glycidyl (meth) acrylate.

In the production of the epoxy group-containing organopolysiloxane of the present invention, first, a dehydrogenative condensation reaction between an organopolysiloxane having OH groups at both ends and an organohydropolysiloxane is carried out.

At this time, the use ratio of the organopolysiloxane having OH groups at both ends and the organohydropolysiloxane is: organohydropolysiloxane / OH at both ends.
The weight ratio of the organopolysiloxane having a group is 99/1 to
It is preferably 5/95. If it exceeds 99/1, the light releasability and slipperiness may be insufficient. 5/9
If it is less than 5, the curability and the residual adhesion ratio may decrease, and 98/2 to 30/70 is preferable. Furthermore, it is preferable that the number of molecules of the organohydropolysiloxane is at least twice the number of molecules of the organopolysiloxane having OH groups at both ends. The SiH group / OH group molar ratio is preferably 2 or more.

A dehydrogenative condensation catalyst is used in the dehydrogenative condensation reaction. As this catalyst, chloroplatinic acid, alcohol solution of chloroplatinic acid, reaction product of chloroplatinic acid and alcohol, reaction product of chloroplatinic acid and olefin compound, reaction product of chloroplatinic acid and vinyl group-containing siloxane, etc. There is a platinum catalyst. The amount of these catalysts added is not particularly limited, but is 0.01 to 5 of the total weight of the organopolysiloxane having OH groups at both terminals and the organohydropolysiloxane.
Wt% may be sufficient. This reaction is usually carried out at room temperature to 300 ° C, but the reaction proceeds faster when heated to 50 ° C or higher. Although the reaction time is not particularly limited, it is preferably 1 to 10 hours. The reaction is carried out in a solvent if necessary. As the solvent, aromatic solvents such as toluene and xylene, aliphatic solvents such as hexane and octane, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate and isobutyl acetate, diisopropyl ether, 1 , An ether solvent such as 4-dioxane, an alcohol solvent such as isopropanol, or a mixed solvent thereof can be used. The reaction atmosphere may be either in air or in an inert gas.

After the completion of the dehydrogenative condensation reaction, an epoxy group- and alkenyl group-containing compound is added to the reaction mixture of the dehydrogenative condensation reaction, or the reaction mixture of the dehydrogenative condensation reaction is added to the epoxy group- and alkenyl group-containing compound and left. SiH
The addition reaction of the group and the alkenyl group is performed.

In this case, after the completion of the dehydrogenative condensation reaction, the dehydrogenative condensation reaction product of the organopolysiloxane having an OH group at each end and the organohydropolysiloxane may be isolated and purified from the reaction mixture. For this, the dehydrogenation condensation catalyst is removed by treating the reaction mixture with an adsorbent such as activated carbon. When a solvent is used, it is distilled off under heating and / or reduced pressure.

The ratio of the dehydrogenative condensation reaction product of the organopolysiloxane having OH groups at both ends and the organohydropolysiloxane to the epoxy group- and alkenyl group-containing compound is such that the number of alkenyl groups is greater than the number of SiH groups. It is preferable to increase the amount of alkenyl group / SiH
The molar ratio of the groups is 1.00 or more, preferably 1.05 to 1.
It is preferably 5. In the addition reaction, an addition reaction catalyst such as a platinum catalyst is used. In this case, a platinum-based catalyst is used as the dehydrogenative condensation reaction catalyst, and since the platinum-based catalyst exists in the system, it is not necessary to add an additional addition reaction catalyst, and the reaction vessel in which the dehydrogenative condensation reaction is performed does not need to be added with epoxy. Conveniently, the group and alkenyl group containing compound can be added to carry out the next addition reaction.

The above reaction may be carried out usually at room temperature to 200 ° C., but the reaction proceeds faster when heated to 50 ° C. or higher. If it exceeds 200 ° C, the reaction mixture may gel. The reaction time is not particularly limited, and the reaction is carried out in the above-mentioned solvent, if necessary. The reaction atmosphere may be either in air or in an inert gas.

After the completion of the addition reaction, the reaction mixture is washed with water or treated with an activated carbon to remove the addition reaction catalyst. When a solvent is used, it is distilled off under heating and / or reduced pressure to obtain an epoxy group-containing organopolysiloxane.

The epoxy group-containing organopolysiloxane of the present invention thus obtained has the following general formula (1):
(2), (3), (4) or (4 ').

[0033]

[Chemical 7] (In the formula, R, p, q, r, s, and n are the same as above,
E represents an epoxy group-containing organic group. )

In this case, examples of the epoxy group-containing organic group include the following groups.

[0035]

[Chemical 8] (However, x = 1 to 10, especially an integer of 2 to 8)

The proportion of epoxy group-containing siloxane units in all siloxane units of the epoxy group-containing organopolysiloxane according to the present invention is preferably 2 to 40 mol%. If it is less than 2 mol%, the curability and the residual adhesion ratio may decrease. When it exceeds 40 mol%, the light releasability and slipperiness are insufficient, and 5 to 25 mol% is preferable.

Specific examples of the epoxy group-containing organopolysiloxane of the present invention include the following.

[0038]

[Chemical 9]

The epoxy group-containing organopolysiloxane of the present invention may be used alone or in combination with the same kind of organopolysiloxane having a different degree of polymerization or epoxy group content, or different epoxy group-containing organopolysiloxanes. And a photoinitiator may be added to obtain a UV-curable organopolysiloxane composition.
This composition is obtained by uniformly mixing predetermined amounts of each component. If necessary, an epoxy-based diluent, a vinyl ether-based diluent, an adhesion improver to a substrate, a leveling agent, an antistatic agent, an antifoaming agent, a pigment, or another type of organopolysiloxane may be added. Alternatively, it may be diluted with an organic solvent before use.

Onium salt photoinitiators are suitable as the above-mentioned photoinitiator, for example, R ¹ ₂ I ⁺ X ⁻ , R ¹ ₃ S ⁺ X ⁻ , R.
_{^{1 3 Se + X -, R}} 1 4 P + X -, R 1 N + X - (R 1 is an aryl group, X ^- is _{^{SbF 6 -, AsF 6 -,}} PF 6 -, BF 4
^- , Anion such as HSO ₄ ⁻ , ClO ₄ ^−, etc.), a triarylsulfonium salt, a triarylselenonium salt, a tetraarylphosphonium salt, an aryldiazonium salt, and the like. The addition amount of the onium salt may be 0.1 to 20 parts by weight with respect to 100 parts by weight of the composition. If it is less than this range, the curability becomes insufficient, and if it is more than that range, the surface condition of the cured film is adversely affected, and the peeling property may deteriorate.

Since the composition of the present invention is easily cured by irradiation with ultraviolet rays in a short time, it can be used as a back-treating agent for pressure-sensitive adhesives, protective coating agents for metals and plastics, and bases for paints.

When a release paper is produced using the composition of the present invention, the base material is a paper base material such as glassine paper, kraft paper or clay coated paper, polyethylene laminated high quality paper,
Laminated paper such as polyethylene laminated kraft paper, plastic film obtained from synthetic resins such as polyester, polypropylene, polyethylene, polyvinyl chloride, polytetrafluoroethylene and polyimide,
Examples thereof include a sheet, a metal foil such as aluminum, and the like.

To apply the composition of the present invention to a substrate, known methods such as roll coating, gravure coating, wire doctor coating, air knife coating and dipping coating can be used. As coating amount, 0.02-100g
/ M ² , and this coating film is easily cured by irradiation with ultraviolet rays. A high-pressure mercury lamp as a light source of ultraviolet rays,
Examples thereof include a medium pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, and a mercury arc lamp. In order to cure the coating film, when a high pressure mercury lamp (80 W / cm) is used, irradiation may be performed from a distance of 5 to 20 cm for 0.01 to 10 seconds.

[0044]

EXAMPLES The present invention will be specifically described below by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples. All parts in the examples are parts by weight.

The evaluation methods adopted in the following examples are as follows. Peeling power The silicone composition was applied to the surface of polyethylene laminated high-quality paper using an offset transfer machine so that the solid content was 0.8 g / m ^2, and a high pressure mercury lamp of 80 W / cm was applied for 8 c.
Irradiation was performed from a distance of m to form a cured film. Acrylic solvent-based adhesive BPS-8170 is applied to the surface of the cured film.
(Toyo Ink Mfg. Co., Ltd.) was applied and heat-treated at 100 ° C. for 3 minutes. Next, a high-quality paper having a basis weight of 64 g / m ² was attached to the treated surface, and the sample was cut into a width of 50 mm,
After aging at 20 ° C. for 20 hours, the laminated paper of the sample was peeled off at a peeling speed of 0.3 m / min at an angle of 180 ° using a tensile tester, and the force required for peeling (g
/ 50 mm) was measured.

Residual Adhesion Rate A cured film of the silicone composition was formed on the surface of the substrate in the same manner as in the measurement of peeling force. Polyester pressure-sensitive adhesive tape 31B (manufactured by Nitto Denko Corporation) was attached to this surface and aged at 70 ° C. for 20 hours under a load of 20 g / cm ² . The tape after this aging was peeled off and attached to a polyester film. Peeling speed of this tape from polyester film at 180 °
It was peeled off in minutes, and the force required for peeling (g / 25 mm) was measured. On the other hand, the force (g / 25 mm) required for peeling the untreated tape not bonded to the silicone cured film from the polyester film was measured, and the ratio of these was taken and expressed as a percentage.

Dynamic Friction Coefficient A cured film of the silicone composition was formed on the surface of the base material in the same manner as in the measurement of peeling force. This was attached to a glass plate and supported horizontally with the surface of the cured silicone film facing up.
On the other hand, the base material having the cured coating formed on the bottom surface of the 200 g weight was also attached so that the silicone surface was facing down. A weight was placed on a horizontally supported silicone film, and the force required for pulling in the horizontal direction at a speed of 0.3 m / min was measured to determine the dynamic friction coefficient.

Example 1 A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a dropping funnel was charged with toluene (78 parts) and dimethyl having OH groups at both ends and having a viscosity of 700 cP at 25 ° C. Polysiloxane (20.6
Parts) and an organohydropolysiloxane represented by the following average composition formula (116 parts). _{Me 3 SiO- (HMeSiO) 3 -} (Me 2 SiO) 25
-SiMe ₃

A 2% solution of platinum catalyst in toluene (0.62 parts) was added thereto, and the mixture was refluxed at 117 ° C. for 3 hours. After cooling to 80 ° C., 4-vinylcyclohexene oxide (23.7 parts) was added dropwise over 2 hours. After the completion of dropping, the mixture was stirred at 80 ° C. for 1 hour. 80 ° C, 3 Torr
Toluene and volatile components were distilled off with a sample 1 (144
Part). Sample 1 had a viscosity of 189 cP and an epoxy equivalent of 1,200.

Example 2 Toluene (172 parts) was added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a dropping funnel, and the viscosity at 25 ° C. was 5,000 cP.
Dimethylpolysiloxane with OH groups at both ends (2
8.9 parts) and organohydropolysiloxane represented by the following average composition formula (163 parts) were charged. _{Me 3 SiO- (HMeSiO) 4 -} (Me 2 SiO) 24
-SiMe ₃

A 2% toluene solution of a platinum catalyst (0.56 parts) was added thereto, and the mixture was refluxed at 117 ° C. for 3 hours. After cooling to 80 ° C., 4-vinylcyclohexene oxide (48.4 parts) was added dropwise over 2 hours. After the completion of dropping, the mixture was stirred at 80 ° C. for 1 hour. 80 ° C, 2 Torr
Toluene and volatile components are distilled off with a sample 2 (220
Part). Sample 2 had a viscosity of 524 cP and an epoxy equivalent of 866.

Example 3 A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a dropping funnel was charged with toluene (125 parts) and dimethyl having OH groups at both ends and having a viscosity of 700 cP at 25 ° C. Polysiloxane (80 parts)
And organohydropolysiloxane (153 parts) represented by the following average composition formula. _{Me 3 SiO- (HMeSiO) 4 -} (Me 2 SiO) 24
-SiMe ₃

A 2% solution of platinum catalyst in toluene (0.55 part) was added thereto, and the mixture was refluxed at 122 ° C. for 3 hours. After cooling to 80 ° C., 4-vinylcyclohexene oxide (45.2 parts) was added dropwise over 2 hours. After the completion of dropping, the mixture was stirred at 80 ° C. for 1 hour. 80 ° C, 2 Torr
Toluene and volatile components are distilled off with a sample 3 (252
Part). Sample 3 had a viscosity of 555 cP and an epoxy equivalent of 1,060.

Example 4 A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a dropping funnel was charged with toluene (127 parts) and dimethyl having OH groups at both ends and having a viscosity of 700 cP at 25 ° C. Polysiloxane (65.5
Part), 1,3,5,7-tetrahydrocyclotetrasiloxane (3.2 parts), and organohydropolysiloxane (153 parts) represented by the following average composition formula. _{Me 3 SiO- (HMeSiO) 4 -} (Me 2 SiO) 24
-SiMe ₃

A 2% toluene solution of platinum catalyst (0.82 parts) was added thereto, and the mixture was refluxed at 117 ° C. for 3 hours. After cooling to 80 ° C., 4-vinylcyclohexene oxide (51.7 parts) was added dropwise over 2 hours. After the completion of dropping, the mixture was stirred at 80 ° C. for 1 hour. 80 ° C, 2 Torr
Toluene and volatile components are distilled off with a sample 4 (243
Part). Sample 4 had a viscosity of 1,400 cP and an epoxy equivalent of 988.

The above samples 1 to 4 are represented by the following formula.

[0057]

[Chemical 10]

Example 5 Sample 1 (100 parts) obtained in Example 1 and an iodonium salt photoinitiator (2 parts) were mixed to prepare a treatment liquid. The peeling force and the residual adhesive force of the cured film of this treatment liquid were measured by the above evaluation methods. The results are shown in Table 1.

Example 6 Sample 2 (100 parts) obtained in Example 2 and the iodonium salt photoinitiator (2 parts) were mixed to prepare a treatment liquid. The peeling force and the residual adhesive force of the cured film of this treatment liquid were measured by the above evaluation methods. The results are shown in Table 1.

Example 7 Sample 3 (100 parts) obtained in Example 3 and the iodonium salt photoinitiator (2 parts) were mixed to prepare a treatment liquid. The peeling force and the residual adhesive force of the cured film of this treatment liquid were measured by the above evaluation methods. The results are shown in Table 1.

Example 8 Sample 4 (100 parts) obtained in Example 4 and an iodonium salt photoinitiator (2 parts) were mixed to prepare a treatment liquid. The peeling force and the residual adhesive force of the cured film of this treatment liquid were measured by the above evaluation methods. The results are shown in Table 1.

Comparative Example 1 The following average composition formula Me ₃ SiO— (EMeSiO) ₃ — (Me ₂ SiO) ₂₅
-SiMe ₃ (E is beta-(3,4-epoxycyclohexyl) ethyl) and organopolysiloxane (100 parts) having an epoxy group represented by the iodonium salt photoinitiator (2 parts)
Were mixed to prepare a treatment liquid. The peeling force and the residual adhesive force of the cured film of this treatment liquid were measured by the above evaluation methods. The results are shown in Table 1.

Comparative Example 2 1,1,3,3-tetramethyi
Ludisiloxane (98 parts) and methyltrimethoxysilane
The mixture of (102 parts) was cooled to 5 ° C. in 24% hydrochloric acid water.
In a mixture of (120 parts) and isopropanol (40 parts)
Slowly add dropwise with stirring to the reaction mixture after completion of the addition
Toluene (40 parts) was added to the product, and the mixture was stirred at 25 ° C for 5 hours.
It was After the hydrochloric acid layer was separated, the toluene layer was washed with water and decompressed.
Upon concentration, a fluid product of the following formula (120 parts) was obtained.
It was (HMeSiO_1/2)_Five(Me SiO_3/2)₃

Organopolysiloxane of the above formula (25
Part) and octamethylcyclotetrasiloxane (317
Parts), add concentrated sulfuric acid (10 parts) and add at room temperature for 20
After allowing the reaction to equilibrate for a period of time, water (17 parts) was added, and further 2
After stirring for an hour, separate the sulfuric acid layer and wash the siloxane layer with water.
Pressure-concentrated and the following formula (HMeSiO_1/2)_Five(Me₂SiO)₉₂(Me SiO
_3/2)₃ Organohydropoly having T unit and SiH group
Siloxane (295 parts) was obtained. This organohydropo
Lisiloxane (100 parts) with toluene (50 parts), 4-
Vinylcyclohexene oxide (10 parts), platinum catalyst
In a mixed solution consisting of 2% toluene solution (0.72 parts)
The mixture was added dropwise at 80 ° C over 2 hours. After dropping, at 90 ℃
Stir for 8 hours. Toluene volatilizes at 80 ° C and 2 Torr
After distilling off the components, the following average composition formula (EMeSiO_1/2)_Five(Me₂SiO)₉₂(Me SiO
_3/2)₃ (E is β- (3,4-epoxycyclohexyl) ethyl
Organopolysiloxane having an epoxy group represented by
Sun sample 5 (105 parts) was obtained. Viscosity 146 cP,
The epoxy equivalent was 1,630.

This organopolysiloxane (100 parts)
And an iodonium salt photoinitiator (2 parts) were mixed to prepare a treatment liquid. The peeling force and the residual adhesive force of the cured film of this treatment liquid were measured by the above evaluation methods. The results are shown in Table 1.

Comparative Example 3 The following average composition formula Me ₃ SiO— (EMeSiO) ₃ — (Me ₂ SiO) ₂₅
-SiMe ₃ (E is a β- (3,4-epoxycyclohexyl) ethyl group) having an epoxy group-containing organopolysiloxane (95 parts) and the following formula Me ₃ SiO— (Ph ₂ SiO) ₅₀ — (Me ₂ SiO) ₄₅₀
A non-reactive organopolysiloxane represented by —SiMe ₃ (5 parts) and an iodonium salt photoinitiator (2 parts) were mixed to prepare a treatment liquid. The peeling force and the residual adhesive force of the cured film of this treatment liquid were measured by the above evaluation methods. The results are shown in Table 1.

[0067]

[Table 1]

[0068]

The epoxy group-containing organopolysiloxane according to the present invention has an epoxy group-free organopolysiloxane chain derived from an organopolysiloxane having OH groups at both ends, and therefore it is the main component. The cured film of the curable composition has excellent releasability and slipperiness for an adhesive substance and does not reduce the adhesive strength of the adhesive layer.

Continuation of the front page (56) Reference JP-A-6-240001 (JP, A) JP-A-8-48781 (JP, A) JP-A-7-331175 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) C08G 77/00-77/62

Claims (3)

(57) [Claims] 1. The following general formulas (1), (2), (3),
An epoxy group-containing organopolysiloxane represented by (4) or (4 ′). [Chemical 1] (In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, p and r are integers of 2 or more, q and s are integers of 0 or more, and n is an integer of 2 or more, E represents an epoxy group-containing organic group.) 2. The following general formula (5) HO (R ₂ SiO) _n H (5) (wherein R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and n is 2 or more). Is an integer) and the hydroxyl groups of the organopolysiloxane in which both ends of the molecular chain are blocked with hydroxyl groups and the following general formulas (6) and / or (7) (In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, a is 0 or 1, p and r are integers of 2 or more,
q and s are integers of 0 or more. ) A first step of dehydrogenative condensation of a SiH group of an organohydropolysiloxane represented by: in the presence of a platinum catalyst, an alkenyl group of an epoxy group- and alkenyl group-containing compound, and a reaction product obtained in the first step And a second step of subjecting the remaining SiH groups to an addition reaction to produce an epoxy group-containing organopolysiloxane. 3. An ultraviolet-curable composition comprising the epoxy group-containing organopolysiloxane according to claim 1 and an onium salt photoinitiator.