JP2013245280A - Radiation-curable silicone composition and release sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation-curable silicone composition, from which such a silicone cured coating can be formed that can develop a sufficient heavy release effect even when a small amount of a heavy release additive is added, and that can suppress decrease in a release force with lapse of time.SOLUTION: A radiation-curable silicone composition comprises: (A) an epoxy group-containing cation polymerizable organopolysiloxane expressed by formula (1):RRSiO(where Rrepresents an epoxy group-containing organic group); (B) a photoacid generator; and (C) a heavy release additive comprising a condensation product obtained by dehydration condensation of (i) a polydiorganosiloxane having an average polymerization degree of 100 to 3,000 and having a hydroxyl group or a hydrolyzable group and (ii) a polyorganosiloxane resin having a (SiO) unit and a (RSiO) unit (in which the total content of hydroxyl groups and hydrolyzable groups is 2.1 mass% or more and less than 10.0 mass%).

Description

  The present invention relates to a radiation curable silicone composition used for a release paper application, and particularly to a radiation curable silicone composition and a release sheet suitable for forming a release paper and a release film for heavy release applications.

  There are various methods for curing the silicone composition. However, in recent years, the curing method by radiation irradiation is energy saving compared to the heat curing type, can be applied even if the installation space is small, and further to the environment. Interest is high due to its characteristics such as a gentle curing system, and it is expected to be used in various fields in the future. Among them, a photoacid generator is used to perform ring opening of an epoxy group, and a curing method using cationic polymerization is less susceptible to curing by oxygen than conventional radical polymerization using an acrylic group or the like. Use is expanding because of its excellent operability (Patent Documents 1 and 2).

  In general, most release papers and release films used for labels and production process papers are surface-treated with a silicone composition mainly composed of polyorganosiloxane, but the release paper and release film silicone used for release papers and release films. Compositions having various peeling forces are required depending on the purpose.

  For example, for industrial labeling that operates at high speed, a release paper or release film having heavy release or variable release characteristics is required. In order to avoid premature release of the label from the release paper, it is desirable that the silicone release agent be a heavy release. The variable release characteristics are such that a peelable double-sided laminate, that is, a light-releasable silicone composition on one side and a heavy-removable silicone composition on the other side is applied and cured to make a difference in peel force. This is useful when providing a laminated body. Furthermore, when the heavy peeling property is necessary, the peeling force does not change with the passage of time, and the properties such as the release paper and the like do not change.

  For applications that require heavy peeling, compositions containing an organopolysiloxane resin are widely used. However, when the organopolysiloxane resin is simply mixed, there is no sufficient heavy peeling effect, and even if it is added in a large amount, the desired peeling force may not be achieved. Therefore, it has been studied to produce release papers and release films having a high heavy release effect by reacting various organosiloxane resins.

Japanese Patent No. 3488272 (Patent Document 3) includes (SiO _4/2 ) unit (Q unit), (R ₃ SiO _1/2 ) unit (M unit), epoxy functional M unit as component (A). , (R ₃ SiO) unit (D unit) or (R ₃ SiO _3/2 ) unit (T unit) and at least one of Q unit, R ² SiO unit (D unit), RSiO _3/2 20 to 80% by mass of a cationically polymerizable organopolysiloxane having a total of at least 5 parts of M units per 10 parts of units (T units) and epoxy functional M units, and epoxy functionality as component (B) An ultraviolet curable resin containing a cationically polymerizable organopolysiloxane containing 80 to 20% by mass of a cationically polymerizable terminal organopolysiloxane containing M units and having an epoxy equivalent of more than 1000 in the formulation, and an onium-based photocatalyst. Poxysilicone compositions have been proposed.
In the examples in Patent Document 3, there is little change in peel strength with time, but 60 parts of organosiloxane resin containing (SiO _4/2 ) units and (R ₃ SiO _1/2 ) units and 50 parts or more of the blend. It is necessary to mix in a large amount, and it is considered that the heavy peeling effect of the heavy peeling component containing the organopolysiloxane resin in Patent Document 3 is small.

  In JP 2010-37557 A (Patent Document 4), the molar ratio of (a1) M unit to Q unit is 0.6 to 1.0, and the content of hydroxyl group or alkoxy group is 0.3. 100 parts by mass of MQ resin in the range of -2.0% by mass and (a2) 20-150 parts by mass of chain diorganosiloxane having an average polymerization degree of 100-1,000 having a hydroxyl group or an alkoxy group were subjected to a condensation reaction. A release regulator composed of an organopolysiloxane resin-organopolysiloxane condensation reaction product has been proposed. Patent Document 4 is an invention related to a heavy release additive for release paper, but there is no particular description regarding radiation curable silicone. In addition, although the peel force in the examples has little change in peel force over time, it increases only 1.4 to 2.2 times at a low speed (0.3 m / min) as compared with the comparative example in which no condensation reaction product is added. In other words, sufficient heavy release hardening has not been obtained.

Japanese Patent No. 3384268 Japanese Patent No. 3993533 Japanese Patent No. 3488272 JP 2010-37557 A

  The present invention has been made in view of the above circumstances, is excellent in the heavy peeling effect, can exhibit a sufficient heavy peeling effect even when a small amount of a heavy peeling additive is added, and can suppress a decrease in peeling force over time. An object of the present invention is to provide a radiation curable silicone composition capable of forming a cured silicone film and a release sheet on which the cured film is formed.

As a result of intensive studies to achieve the above object, the present inventors have obtained an average degree of polymerization of 100 to 3,000, and a polydiorganosiloxane having one or more hydroxyl groups or hydrolyzable groups in one molecule. And a (SiO _4/2 ) unit and a (R ³ ₃ SiO _1/2 ) unit [wherein R ³ independently represents a monovalent hydrocarbon having 1 to 12 carbon atoms and having no aliphatic unsaturated bond. Group or an alkenyl group having 2 to 6 carbon atoms. ], The ratio of (R ³ ₃ SiO _1/2 ) units to (SiO _4/2 ) units is 0.6 to 1.2, and the total content of hydroxyl groups and hydrolyzable groups is It has been found that a condensation reaction product obtained by subjecting a polyorganosiloxane resin having a content of 2.1% by mass or more and less than 10.0% by mass to a dehydration condensation reaction under a catalyst has an excellent heavy release effect and is effective as a heavy release additive. Furthermore, by adding a reaction product of the polydiorganosiloxane having one or more hydrolyzable groups and a polyorganosiloxane resin as a heavy release additive to the radiation-curable cationic polymerizable silicone composition, It has been found that even when a small amount of a peeling additive is added, there is a large heavy peeling effect and a reduction in peeling force with time can be suppressed.
Therefore, the radiation curable silicone composition described below was difficult to achieve when conventional heavy release additives were used, and a sufficient heavy release effect was obtained even when a small amount of heavy release additive was added. It was confirmed that the decrease in peel strength over time could be suppressed, and the present invention was completed.

（式中、Ｒｆは水素原子の８０モル％以上がフッ素原子で置換された炭素原子数１〜８のアルキル基を表す。ｐはその個数を示し、１〜５の整数である。ｐ個のＲｆはそれぞれ同一であっても異なっていてもよい。）
〔８〕 （Ａ）成分における１価のエポキシ官能性有機基で置換されたケイ素原子が全ケイ素原子中１〜３０モル％あることを特徴とする〔１〕〜〔７〕のいずれかに記載の放射線硬化性シリコーン組成物。
〔９〕 〔１〕〜〔８〕のいずれかに記載の放射線硬化性シリコーン組成物の硬化皮膜がシート状基材に形成された剥離シート。 Accordingly, the present invention provides the following radiation curable silicone composition and release sheet.
[1] (A) The following average composition formula (1)
R ¹ _m R ² _n SiO _{(4-mn) / 2} (1)
(Wherein R ¹ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ² is an organic group containing an epoxy group, and m> 0, n> 0, 0 <M + n ≦ 3.)
A cationically polymerizable organopolysiloxane containing an epoxy group represented by the formula: 100 parts by mass (B) Photoacid generator component exhibiting catalytic action for radiation curing reaction of the cationically polymerizable organopolysiloxane (A): 0.05 to 20 parts by mass (C) (i): a polydiorganosiloxane having an average degree of polymerization of 100 to 3,000 and having one or more hydroxyl groups or hydrolyzable groups in one molecule;
(Ii): (SiO _4/2 ) unit and (R ³ ₃ SiO _1/2 ) unit [wherein R ³ is independently monovalent from 1 to 12 carbon atoms not having an aliphatic unsaturated bond. It is a hydrocarbon group or an alkenyl group having 2 to 6 carbon atoms. ] As a main component, and the ratio of (R ³ ₃ SiO _1/2 ) units to (SiO _4/2 ) units is 0.6 to 1.2 in terms of molar ratio, and the total of hydroxyl groups and hydrolyzable groups Heavy release additive comprising a condensation reaction product obtained by subjecting a polyorganosiloxane resin having a content of 2.1% by mass or more and less than 10.0% by mass to a dehydration condensation reaction: 0.5 to 50 parts by mass A radiation curable silicone composition characterized by that.
[2] The radiation curable silicone composition according to [1], wherein the total content of hydroxyl groups and hydrolyzable groups in the component (ii) is 3.0% by mass or more and less than 10.0% by mass. .
[3] The radiation curable silicone composition according to [1] or [2], wherein the polydiorganosiloxane as the component (i) has an average degree of polymerization of 200 to 2,500.
[4] The heavy release additive of the component (C) is a condensation reaction product obtained by a dehydration condensation reaction in which the ratio of the component (i) to the component (ii) is 30:70 to 70:30 as a mass ratio. The radiation-curable silicone composition according to [1], [2] or [3].
[5] The heavy release additive of component (C) is diluted with an organopolysiloxane, and the organopolysiloxane used for the dilution is a cationic polymerizable organopolysiloxane containing an epoxy group. [1] The radiation curable silicone composition according to any one of [4].
[6] The radiation-curable silicone composition according to [5], wherein the cationic polymerizable organopolysiloxane used for dilution has a viscosity of 2 to 200 mPa · s.
[7] The component (B) is a fluorinated alkylfluorophosphate, diaryliodonium hexafluoroantimonate, triarylsulfonium salt, triarylselenonium salt, tetraarylphosphonium salt represented by the following composition formula (2) The radiation curable silicone composition according to any one of [1] to [6], wherein the radiation curable silicone composition is selected from aryl diazonium salts.

(In the formula, Rf represents an alkyl group having 1 to 8 carbon atoms in which 80 mol% or more of hydrogen atoms are substituted with fluorine atoms. P represents the number and is an integer of 1 to 5. Rf may be the same or different.
[8] The silicon atom substituted with a monovalent epoxy functional organic group in the component (A) is 1 to 30 mol% in all silicon atoms, [1] to [7] Radiation curable silicone composition.
[9] A release sheet in which a cured film of the radiation curable silicone composition according to any one of [1] to [8] is formed on a sheet-like substrate.

  The radiation-curable silicone composition of the present invention can exhibit a sufficient heavy peeling effect as compared with the conventional heavy peeling additive even when a small amount of the heavy peeling additive component is added, and peels with time. A decrease in force can be suppressed, and a release sheet such as release paper and release film excellent in heavy release effect can be obtained.

  The radiation curable silicone composition of the present invention contains the components (A), (B), and (C), and will be described in detail below with respect to the individual components.

The component (A) in the radiation curable silicone composition of the present invention is a cationic polymerizable organopolysiloxane, and those represented by the following average composition formula (1) are preferable.
R ¹ _m R ² _n SiO _{(4-mn) / 2} (1)
In the formula (1), R ¹ is an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group or a tolyl group, or a carbon atom of these groups From a hydroxypropyl group, a cyanoethyl group, a 1-chloropropyl group, a 3,3,3-trifluoropropyl group, etc., in which some or all of the hydrogen atoms bonded to are substituted with a hydroxy group, a cyano group, a halogen atom, etc. The unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ² is a cationic polymerizable epoxy functional group. m and n are m> 0, n> 0, 0 <m + n ≦ 3, and 80 mol% or more of R ¹ is preferably an alkyl group, and more preferably a methyl group. As the cationic polymerizable epoxy functional group of R ^2, the following structure is preferable.

  As the component (A), a cation polymerizable organopolysiloxane in which the silicon atom substituted with a monovalent epoxy-functional organic group is 1 to 30 mol% in all silicon atoms is preferable from the viewpoint of curability, and more The cationically polymerizable organopolysiloxane is preferably 2 to 25 mol%, more preferably 3 to 20 mol%. If the amount of this epoxy functional group is less than 1 mol%, the curing rate may be slowed, resulting in poor curing.

  From this point, m and n are sufficient if the amount of the epoxy functional group of the organopolysiloxane is the above value, and the viscosity is preferably in the range of 1,000,000 mPa · s or less. In this case, the preferable range of m is 1.6 to 2.4, more preferably 1.65 to 2.35, still more preferably 1.70 to 2.30, and the preferable range of n is 0.01 to 0. .30, more preferably 0.2 to 0.25, still more preferably 0.3 to 0.20.

  The organopolysiloxane preferably has a viscosity of 1,000,000 mPa · s or less, more preferably 100,000 mPa · s or less. When it exceeds 1 million mPa · s, the viscosity of the composition becomes high and handling may be difficult. In this case, the lower limit of the viscosity is preferably 5 mPa · s or more, and particularly preferably 10 mPa · s or more. The viscosity is a value measured using a BN type rotational viscometer. Moreover, the blending ratio of the other components is adjusted based on 100 parts by weight of the cationic polymerizable organopolysiloxane (A).

  The component (B) in the radiation curable silicone composition of the present invention is a photoacid generator component that exhibits a catalytic action on the radiation curing reaction of the cationic polymerizable organopolysiloxane (A). Examples of the component (B) include fluorinated alkyl fluorophosphates represented by the following composition formula (2) and those represented by the following general formula (3).

In the composition formula (2), [(Rf) _p PF _6-p ] ⁻ is a fluorinated alkylfluorophosphate anion, Rf represents an alkyl group substituted with a fluorine atom, and preferably has 1 to 8 carbon atoms. Furthermore, the more preferable carbon atom number is 1-4. Specific examples of the alkyl group include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl and octyl, branched alkyl groups such as isopropyl, isobutyl, sec-butyl and tert-butyl, and cyclopropyl, cyclobutyl and cyclopentyl. And cycloalkyl groups such as cyclohexyl and the like. The proportion of alkyl group hydrogen atoms replaced by fluorine atoms is usually 80 mol% or more, preferably 90 mol% or more, and more preferably 100 mol%. When the substitution rate of fluorine atoms is less than 80 mol%, the cationic polymerization initiating ability of the onium salt of the present invention may be lowered.

Particularly preferred Rf is a linear or branched perfluoroalkyl group having 1 to 4 carbon atoms and a fluorine atom substitution rate of 100 mol%. Specific examples include CF ₃ , CF ₃ CF ₂ , (CF ₃ ) ₂ CF, CF ₃ CF ₂ CF ₂ , CF ₃ CF ₂ CF ₂ CF ₂ , (CF ₃ ) ₂ CFCF ₂ , CF ₃ CF ₂ (CF ₃ ) CF, (CF ₃ ) ₃ C may be mentioned. .
Moreover, in Formula (2), the number p of Rf is an integer of 1-5, Preferably it is 2-4, Most preferably, it is 2 or 3. The p Rf's may be the same or different. Specific examples of preferred fluorinated alkyl fluorophosphate anions include
[(CF ₃ CF ₂ ) ₂ PF ₄ ] ⁻ , [(CF ₃ CF ₂ ) ₃ PF ₃ ] ⁻ , [((CF ₃ ) ₂ CF) ₂ PF ₄ ] ⁻ , [((CF ₃ ) ₂ CF) ₃ PF ₃ ] ⁻ , [(CF ₃ CF ₂ CF ₂ ) ₂ PF ₄ ] ⁻ , [(CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ] ⁻ , [((CF ₃ ) ₂ CFCF ₂ ) ₂ PF ₄ ] _{^{-, [((CF 3)}} 2 CFCF 2) 3 PF 3] -, [(CF 3 CF 2 CF 2 CF 2) 2 PF 4] - and _{[(CF 3 CF 2 CF 2} CF 2) 3 PF 3] ^- Of these, [(CF ₃ CF ₂ ) ₃ PF ₃ ] ⁻ , [(CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ] ⁻ , [((CF ₃ ) ₂ CF) ₃ PF ₃ ] ⁻ , [( CF ₃ ) ₂ CF) ₂ PF ₄ ] ⁻ , [((CF ₃ ) ₂ CFCF ₂ ) ₃ PF ₃ ] ⁻ and [((CF ₃ ) ₂ CFCF ₂ ) ₂ PF ₄ ] ⁻ are particularly preferred. )

What is represented by the general formula (3) is as follows.
R ⁴ ₂ I ⁺ X ⁻ , R ⁴ ₃ S ⁺ X ⁻ , R ⁴ ₃ Se ⁺ X ⁻ , R ⁴ ₄ P ⁺ X ⁻ , or R ⁴ ₄ N ⁺ X ⁻ (3)
(Wherein R ⁴ is a substituted or unsubstituted aryl group such as a phenyl group, a tolyl group, and a 4- (ethyl) phenyl group), a substituted or unsubstituted heterocyclic group such as a pyridyl group, N-methylpyridyl, and an indolyl group. , A substituted or unsubstituted aryloxy group such as a methoxyphenyl group and an isopropoxyphenyl group, a substituted or unsubstituted heterocyclic oxy group such as a 4-methoxypyridyl group, and R ⁴ are bonded to each other and bonded to each other. , S, Se, P or N may form a ring structure, and X ⁻ is an anion such as SbF ₆ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , BF ₄ ⁻ , HSO ₄ ⁻ or ClO ₄ ^−. is there.)
And diaryl iodonium salts, triaryl sulfonium salts, triaryl selenonium salts, tetraaryl phosphonium salts, aryl diazonium salts and the like. Among them, diaryl iodonium salts such as diaryl iodonium hexafluoroantimonate and triarylsulfonium hexafluoroantimonate are preferable from the viewpoint of curing reactivity.

  The amount of component (B) added is not particularly limited as long as it is an effective amount as an onium salt photoinitiator, that is, an amount effective to cure the silicone composition of the present invention by irradiation with ultraviolet rays. ) 0.05 to 20 parts by mass with respect to 100 parts by mass of the component.

  The component (C) of the radiation curable silicone composition of the present invention is a heavy release additive comprising a condensation reaction product obtained by subjecting the following components (i) and (ii) to a dehydration condensation reaction under a catalyst.

（式（Ａ−１ａ）中、Ｒ^1aは同一又は異種の脂肪族不飽和結合を有さない炭素原子数１〜１０の一価炭化水素基であり、Ｒ^2aは水酸基又は加水分解性基である。ｅは１００〜３，０００の整数である。） The component (i) is a polydiorganosiloxane having an average degree of polymerization of 100 to 3,000 and having one or more hydroxyl groups or hydrolyzable groups in one molecule, and is represented by the following general formula (A-1a). The thing can be illustrated.

(In Formula (A-1a), R ^1a is a monovalent hydrocarbon group having 1 to 10 carbon atoms that does not have the same or different aliphatic unsaturated bond, and R ^2a is a hydroxyl group or a hydrolyzable group. E is an integer from 100 to 3,000.)

In the general formula (A-1a), R ^1a is a monovalent hydrocarbon group having 1 to 10 carbon atoms that does not have the same or different aliphatic unsaturated bond, such as a methyl group, an ethyl group, or a propyl group. An alkyl having 1 to 6 carbon atoms, such as a butyl group, preferably a cyclohexyl group, preferably 5 to 8 carbon atoms, preferably an aryl having 6 to 10 carbon atoms such as a cycloalkyl group, a phenyl group, a tolyl group, etc. Group, etc., and a methyl group is particularly preferable.
R ^2a is a hydroxyl group or a hydrolyzable group, and the hydrolyzable group means an alkoxy group having 1 to 6 carbon atoms, a halogen atom, an acyloxy group, an oxime group, and the like. R ^2a is preferably a hydroxyl group, particularly preferably those having two hydroxyl groups in one molecule, particularly those having hydroxyl groups at both ends. Moreover, as an alkoxy group, a C1-C6 thing is preferable and a methoxy group, an ethoxy group, a propoxy group, a butoxy group etc. can be mentioned as an example. As a halogen atom, a chlorine atom, a bromine atom, etc. can be mentioned as an example.

The average degree of polymerization, that is, the average degree of polymerization e in the above formula (A-1a) is 100 to 3,000, preferably 200 to 2,500. When the average degree of polymerization is less than 100, the fluidity of the component (C) is lowered, but unreacted silicone molecules are increased and the peeling force is often lowered. Moreover, when the average degree of polymerization exceeds 3,000, the viscosity of the reaction product becomes high, and it may be difficult to uniformly disperse the radiation-curable silicone composition.
The average degree of polymerization corresponds to -Si (R ^1a ) ₂ -O-unit (D unit) and CH ₃ -Si (R ^1a ) ₂ -O-unit (M unit) in ²⁹ Si-NMR. converting the respective integral values of peaks M ₂ D _X, it was determined polymerization degree X (hereinafter the same). R ^1a is as described above.

The component (ii) includes (SiO _4/2 ) units (Q units) and (R ³ ₃ SiO _1/2 ) units (M units) [wherein R ³ each independently has an aliphatic unsaturated bond. A monovalent hydrocarbon group having 1 to 12 carbon atoms or an alkenyl group having 2 to 6 carbon atoms. ] As a main component. In this case, the ratio of (R ³ ₃ SiO _1/2 ) units to (SiO _4/2 ) units is 0.6 to 1.2 as a molar ratio, and 0.7 to 1.1 is particularly preferable. A range of 0.75 to 1.0 is more preferable. When the ratio of M units to Q units is less than 0.6, the viscosity of the dehydration condensation reaction product becomes too high, making synthesis difficult. If it exceeds 1.2, the degree of polymerization cannot be increased, so that the effect of heavy peeling also decreases.

R ³ in the above formulas independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms or an alkenyl group having 2 to 6 carbon atoms which does not have an aliphatic unsaturated bond, and the carbon atom of R ³ The monovalent hydrocarbon group of 1 to 12 is preferably a methyl group, an ethyl group, a propyl group, a butyl group or the like, preferably an alkyl group having 1 to 6 carbon atoms, a phenyl group or a tolyl group, preferably a carbon atom number Examples thereof include aralkyl groups having 7 to 10 carbon atoms such as 6 to 10 aryl groups and benzyl groups. Examples of the alkenyl group having 2 to 6 carbon atoms include a vinyl group, an allyl group, and a butenyl group.
In this case, the polyorganosiloxane resin can be obtained by cohydrolysis / condensation of tetraorganoxysilane and triorganomonoorganoxysilane, and therefore R ³⁰ iO _3/2 units derived from tetraorganoxysilane. (T unit), and optionally R ³⁰ ₂ SiO _2/2 unit (D unit).
R ³⁰ is a hydroxyl group or a hydrolyzable group such as an alkoxy group having 1 to 6 carbon atoms, an acyloxy group, an oxime group, or a halogen atom, but not all R ³⁰ are a hydroxyl group, preferably a hydroxyl group, A methoxy group, an ethoxy group or a propoxy group;

  The total content of hydroxyl groups and hydrolyzable groups means the total content of hydroxyl groups and the above hydrolyzable functional groups, and is 2.1% by mass or more and less than 10.0% by mass in the polyorganosiloxane resin. Preferably it is 2.5 mass% or more and 7.0 mass% or less, More preferably, it is 4.0 mass% or more and 6.0 mass% or less. When the content is less than 2.1% by mass, the heavy peeling effect is not large. The reason for this is not clear, but it is probably due to the low crosslinking density due to the condensation reaction. Moreover, in the case of 10.0 mass% or more, the adhesiveness to a base material will deteriorate remarkably.

The (B) component polyorganosiloxane resin may further contain R ³ ₂ SiO _2/2 units or R ³ SiO _3/2 units (R ³ is as described above). In this case, the total of these units is 0 to 30 mol%, preferably 0 to 20 mol%, more preferably 0 to 10 mol% of the whole polyorganosiloxane resin.

  When the component (i) and the component (ii) are subjected to a dehydration condensation reaction, in the presence of a catalyst, first, a hydroxyl group of the component (i), a hydrolyzable group such as an alkoxy group of the component (ii), and a component (ii) The hydroxyl group and hydrolyzable group of each other are condensed. Thereafter, most of the hydrolyzable groups gradually change to hydroxyl groups, and condensation between the hydroxyl groups proceeds.

  The (i) component and the (ii) component can produce a sticky compound by performing a condensation reaction at room temperature or under heating, preferably at 20 to 80 ° C., using a catalyst. Examples of the catalyst include ammonia water, amines such as ethylamine, bases such as potassium hydroxide and sodium hydroxide, titanium compounds such as tetrabutyl titanate, hexamethyldisilazane, and the like. In addition, the usage-amount of a catalyst has preferable 0.1-3,000 ppm with respect to the total amount of (i) component and (ii) component.

  The mixing ratio of the component (i) and the component (ii) is preferably 30:70 to 70:30, more preferably 40:60 to 60:40, as a mass ratio. When the mixing ratio of the component (i) is less than 30, the viscosity of the condensate increases rapidly and handling may be difficult. On the other hand, when the mixing ratio of the component (i) exceeds 70, the heavy peeling effect may be extremely deteriorated.

In the dehydration condensation reaction product of component (i) and component (ii), the amount of remaining hydroxyl group is preferably 0.3% by mass or less (0.017 mol / 100 g or less), more preferably 0.26 mass. % Or less (0.015 mol / 100 g or less). When the amount of the remaining hydroxyl group exceeds 0.3% by mass, the adhesion may be deteriorated.
When the amount of hydroxyl group remaining in component (C), which is a condensation reaction product of component (i) and component (ii), is large, the number of hydroxyl groups can be reduced by adding chlorosilane in a post reaction. Thereby, the problem of the viscosity increase of a radiation curable silicone composition can be suppressed. In this case, the amount of chlorosilane used is preferably 0.1 to 10 parts by mass, more preferably 1 to 8.0 parts by mass with respect to component (ii).

  Since the heavy release additive according to the present invention has a high viscosity, it is preferably diluted with an organopolysiloxane and finally used at a viscosity of 100 to 100,000 mPa · s (25 ° C.). The organopolysiloxane used as the diluent is preferably a cationically polymerizable polysiloxane having a viscosity at 25 ° C. of 2 to 200 mPa · s. Using a cationic polymerizable polysiloxane in the above viscosity range not only reduces the viscosity of the heavy release additive (C), but also has a cationic polymerizable functional group so that a diluent can be incorporated into the cured structure. Bleeding out of the agent onto the cured film can be prevented. The viscosity is a value measured with a BN type rotational viscometer.

  Further, as the cationically polymerizable organopolysiloxane used as a diluent, the content of the epoxy group which is a cationically polymerizable group is arbitrary, but the silicon atom substituted with a monovalent epoxy functional organic group is all silicon. If it is 1-30 mol% in an atom, the bleed-out on a cured film can be suppressed more.

  In some cases, the heavy release additive according to the present invention can be diluted with an organic solvent for use, but preferably no organic solvent is used.

  The radiation curable silicone composition of the present invention is obtained by blending a predetermined amount of the above components, but in addition to the above components, as optional components, a filler, an antistatic agent, a flame retardant, an antifoaming agent, Additives such as flow regulators, light stabilizers, solvents, non-reactive resins, and radical polymerizable compounds can be used. The amount of the optional component added can be a normal amount as long as the effects of the present invention are not hindered.

The radiation curable silicone composition of the present invention can be cured by irradiation with radiation energy rays. As the radiation energy ray, any radiation energy ray may be used as long as it has energy that induces decomposition of the photoacid generator as the component (B). Preferably, it is a high-pressure or ultrahigh-pressure mercury lamp, metal halide lamp, xenon lamp, carbon arc lamp. Energy beams in the ultraviolet to visible light region (about 100 to about 800 nm) obtained from fluorescent lamps, semiconductor solid lasers, argon lasers, He—Cd lasers, KrF excimer lasers, ArF excimer lasers, F ₂ lasers, and the like are used. A radiation light source having a strong light hardness of 200 to 400 nm is preferable. The ultraviolet irradiation amount is preferably 5 to 1,000 mJ, particularly preferably 10 to 500 mJ. Furthermore, radiation having high energy such as electron beam and X-ray can be used. The irradiation time of radiation energy is usually about 0.1 seconds to 10 seconds at room temperature. However, when the energy ray transmission is low or the film thickness of the curable composition is large, the irradiation time is longer. It may be preferable to spend time. If necessary, after irradiation with energy rays, it can be heated at room temperature to 150 ° C. for several seconds to several hours, and aftercured.

In this case, when the release sheet is formed, the solid content is added to a thin film material such as paper, glassine paper, polyethylene laminated paper, clay coated paper, polyethylene film, polypropylene film, PET film, polyimide, and polyvinyl chloride. Can be applied to a thickness of 0.1 to 5 g / m ² and irradiated with radiation as described above to form a cured film having desired releasability.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited by this. In the following examples, the physical properties in the table are measured by the following test methods. The viscosity is a value at 25 ° C. measured with a BN type rotational viscometer. The average degree of polymerization was determined in the same manner as described above. In order to evaluate the cured film of the silicone composition of the present invention, the peel force was measured as follows.

Moreover, Me in a structural formula shows a methyl group and Ep shows the following epoxy functional group.

<Initial peeling force>
After preparing the radiation-curable silicone composition, it was coated on a polyethylene laminate fine paper at a coating amount of about 0.8 g / m ² by roll coating to obtain a coating film. The obtained coating film was irradiated with ultraviolet rays having an irradiation amount of 50 mJ / cm ² using two 80 W / cm high-pressure mercury lamps to form a cured coating film. After the obtained cured film was stored at 23 ° C. for 20 hours, an acrylic adhesive tape TESA7475 (trade name) having a width of 25 mm was pasted on the surface of the cured film, and a 2 kg roller was reciprocated once for pressure-bonding. A sample was made.
The sample was aged at 70 ° C. for 20 to 24 hours while applying a load of 70 g / cm ² . Then, the force (N / 25 mm) required for pulling and peeling the bonded tape was measured using a tensile tester at an angle of 180 ° and a peeling speed of 0.3 m / min.

<Aging force>
After preparing the radiation-curable silicone composition, it was coated on a polyethylene laminate fine paper at a coating amount of about 0.8 g / m ² by roll coating to obtain a coating film. The obtained coating film was irradiated with ultraviolet rays having an irradiation amount of 50 mJ / cm ² using two 80 W / cm high-pressure mercury lamps to form a cured coating film. After the obtained cured film was stored at 50 ° C. for 7 days, an acrylic pressure-sensitive adhesive tape TESA7475 (trade name) having a width of 25 mm was applied to the surface of the cured film, and a 2 kg roller was reciprocated once for pressure-bonding. A sample was made.
The sample was aged at 70 ° C. for 20 to 24 hours while applying a load of 70 g / cm ² . Then, the force (N / 25 mm) required for pulling and peeling the bonded tape was measured using a tensile tester at an angle of 180 ° and a peeling speed of 0.3 m / min.

Synthesis of heavy release additives listed in Table 1 [Synthesis Example 1]

50 parts by mass of the linear dimethylpolysiloxane corresponding to the component (i) which is the component of the present invention and represented by the above average composition formula (i-1) and having both ends being hydroxydimethylsiloxy groups, Corresponds to a certain component (ii) and consists of Me ₃ SiO _0.5 unit (M unit), SiO ₂ unit (Q unit), (CH ₃ O) SiO _3/2 unit and (HO) SiO _3/2 unit. MQ resin, M / Q (molar ratio) = 0.8, total content of hydroxyl group and alkoxy group 4.29% by mass (hydroxyl group content 1.19% by mass, alkoxy group content 3.1% by mass) 50 parts by mass (125 parts by mass including volatile components) of solid polyorganosiloxane resin containing 60% by mass of toluene, 10 parts by mass of toluene, 0.4% of 28% by mass of ammonia water The solution mixed with parts by mass is at room temperature. After stirring for 6 h, fitted with a Dean-Stark tube, reflux toluene at an inner temperature of 110 to 120 ° C., to remove ammonia and water.
The non-volatile content of the obtained reaction mixture was measured, and the silicon atoms substituted with monovalent epoxy-functional organic groups as diluents were 20% by mass with respect to the non-volatile content of 80% by mass. A cationically polymerizable organopolysiloxane having a content of 10 mol% and a viscosity of 20 mPa · s is added, the temperature is raised to 100 ° C. under reduced pressure and nitrogen bubbling conditions, and toluene is removed to obtain a viscosity of 4,500 mPa · s. -The heavy peeling additive (c-1) of s was prepared (the amount of residual hydroxyl groups of the condensation reaction product; 0.26% by mass).

[Synthesis Example 2]
The linear dimethylpolysiloxane in which both ends described in Synthesis Example 1 are hydroxydimethylsiloxy groups corresponds to the component (i) that is a component of the present invention, except that it is the following average composition formula (i-2). Then, by performing the same procedure as in Synthesis Example 1, a heavy release additive (c-2) having a viscosity of 5,000 mPa · s was prepared (the amount of residual hydroxyl groups in the condensation reaction product: 0.24% by mass).

[Synthesis Example 3]
Synthesizing except that the linear dimethylpolysiloxane whose both ends are hydroxydimethylsiloxy groups described in Synthesis Example 1 corresponds to the component (i) which is a component of the present invention and is the following average composition formula (i-3). By carrying out the same procedure as in Example 1, a heavy release additive (c-3) having a viscosity of 5,500 mPa · s was prepared (the amount of residual hydroxyl groups of the condensation reaction product: 0.23% by mass).

[Synthesis Example 4]
The linear dimethylpolysiloxane in which both ends described in Synthesis Example 1 are hydroxydimethylsiloxy groups corresponds to the component (i) which is a component of the present invention, except that it is the following average composition formula (i-4). By carrying out the same procedure as in Synthesis Example 1, a heavy release additive (c-4) having a viscosity of 6,500 mPa · s was prepared (the amount of residual hydroxyl groups in the condensation reaction product: 0.22% by mass).

[Synthesis Example 5]
As compounds corresponding to the component (ii) described in Synthesis Example 1, Me ₃ SiO _0.5 unit (M unit), SiO ₂ unit (Q unit), (CH ₃ O) SiO _3/2 unit, and (HO) SiO MQ resin composed of _3/2 units, M / Q (molar ratio) = 0.8, total content of hydroxyl group and alkoxy group 1.89% (hydroxyl group content 0.34% by mass, alkoxy group contained) 1.55% by mass), and the same procedure as in Synthesis Example 1 except that 50 parts by mass (125 parts by mass including volatile components) of a solid polyorganosiloxane resin in which toluene accounts for 60% by mass was used. Was performed to prepare a heavy release additive (c-5) having a viscosity of 4,000 mPa · s (the amount of residual hydroxyl groups of the condensation reaction product: 0.11% by mass).

[Synthesis Example 6]
By performing the same procedure as in Synthesis Example 1 except that the linear dimethylpolysiloxane having both ends of hydroxydimethylsiloxy group described in Synthesis Example 1 has the following average composition formula (i-5), the viscosity is increased. A heavy release additive (c-6) of 75 mPa · s was prepared (the amount of residual hydroxyl groups in the condensation reaction product; 0.20% by mass).

[Example 1]
It corresponds to the component (A) according to the present invention, and is a cationically polymerizable organopolysiloxane represented by the following average composition formula (a), wherein the silicon atoms substituted with monovalent epoxy-functional organic groups are 8 out of all silicon atoms. 90 parts by mass of organopolysiloxane (a) having a viscosity of 2% by mass and a viscosity at 25 ° C. of 150 mPa · s is 50% in toluene corresponding to the photoacid generator (B) which is a component according to the present invention. 1.0 mass part of 4- (isopropyl) phenyl (p-tolyl) iodonium tris (pentafluoroethyl) trifluorophosphate solution (b-1) dissolved in mass%, (C) heavy release addition which is a component according to the present invention 12.5 parts by mass of the heavy release additive (c-1) of Synthesis Example 1 corresponding to the agent was uniformly mixed to obtain a silicone composition 1. The peel strength of this silicone composition 1 was measured, and the results are shown in Table 1.

[Example 2]
The (B) photoacid generator according to the present invention is 1.0 mass of a bis- [4-nalkyl (C10-C13) phenyl] iodonium hexafluoroantimonate solution (b-2) dissolved in 92 mass% in acetonitrile. The silicone composition 2 was obtained by performing the same procedure as Example 1 except the point which is a part. The peel strength of this silicone composition 2 was measured, and the results are shown in Table 1.

[Example 3]
By performing the same procedure as in Example 2 except that (C) the heavy release additive according to the present invention is 12.5 parts by mass of the heavy release additive (c-2) of Synthesis Example 2, the silicone composition Product 3 was obtained. The peel strength of this silicone composition 3 was measured, and the results are shown in Table 1.

[Example 4]
By performing the same procedure as in Example 2 except that (C) heavy release additive which is a component according to the present invention is 12.5 parts by mass of heavy release additive (c-3) of Synthesis Example 3. A silicone composition 4 was obtained. The peel strength of this silicone composition 4 was measured, and the results are shown in Table 1.

[Example 5]
By performing the same procedure as in Example 2 except that (C) heavy release additive which is a component related to the present invention is 12.5 parts by mass of heavy release additive (c-4) of Synthesis Example 4. A silicone composition 5 was obtained. The peel strength of this silicone composition 5 was measured, and the results are shown in Table 1.

[Comparative Example 1]
100 parts by mass of the organopolysiloxane (a) represented by the above average composition formula (a) corresponding to the average composition formula (1) which is a component according to the present invention, and (B) photoacid generation which is a component according to the present invention. A silicone composition was uniformly mixed with 1.0 part by mass of a bis- [4-nalkyl (C10-C13) phenyl] iodonium hexafluoroantimonate solution (b-2) dissolved in 92% by mass of acetonitrile corresponding to the agent. 6 was obtained. The peel strength of this silicone composition 6 was measured, and the results are shown in Table 1.

[Comparative Example 2]
The silicone composition 7 was obtained by performing the same procedure as Example 2 except that the heavy release additive was 12.5 parts by mass of the heavy release additive (c-5) of Synthesis Example 5. The peel strength of this silicone composition 7 was measured, and the results are shown in Table 1.

[Comparative Example 3]
The silicone composition 8 was obtained by performing the procedure similar to Example 2 except the heavy peeling additive is 12.5 mass parts of heavy peeling additives (c-6) of the synthesis example 6. The peel strength of this silicone composition 8 was measured, and the results are shown in Table 1.

＊ 光酸発生剤の固形分の質量部

* Mass part of solid content of photoacid generator

Claims (9)

(A) The following average composition formula (1)
R ¹ _m R ² _n SiO _{(4-mn) / 2} (1)
(Wherein R ¹ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ² is an organic group containing an epoxy group, and m> 0, n> 0, 0 <M + n ≦ 3.)
A cationically polymerizable organopolysiloxane containing an epoxy group represented by the formula: 100 parts by mass (B) Photoacid generator component exhibiting catalytic action for radiation curing reaction of the cationically polymerizable organopolysiloxane (A): 0.05 to 20 parts by mass (C) (i): a polydiorganosiloxane having an average degree of polymerization of 100 to 3,000 and having one or more hydroxyl groups or hydrolyzable groups in one molecule;
(Ii): (SiO _4/2 ) unit and (R ³ ₃ SiO _1/2 ) unit [wherein R ³ is independently monovalent from 1 to 12 carbon atoms not having an aliphatic unsaturated bond. It is a hydrocarbon group or an alkenyl group having 2 to 6 carbon atoms. ] As a main component, and the ratio of (R ³ ₃ SiO _1/2 ) units to (SiO _4/2 ) units is 0.6 to 1.2 in terms of molar ratio, and the total of hydroxyl groups and hydrolyzable groups Heavy release additive comprising a condensation reaction product obtained by subjecting a polyorganosiloxane resin having a content of 2.1% by mass or more and less than 10.0% by mass to a dehydration condensation reaction: 0.5 to 50 parts by mass A radiation curable silicone composition characterized by that.   The radiation curable silicone composition according to claim 1, wherein the total content of hydroxyl groups and hydrolyzable groups in component (ii) is 3.0% by mass or more and less than 10.0% by mass.   The radiation-curable silicone composition according to claim 1 or 2, wherein the polydiorganosiloxane as the component (i) has an average degree of polymerization of 200 to 2,500.   The heavy release additive of component (C) is a condensation reaction product obtained by a dehydration condensation reaction in which the ratio of the component (i) to the component (ii) is 30:70 to 70:30 as a mass ratio. Item 4. The radiation curable silicone composition according to item 1, 2 or 3.   The heavy release additive of component (C) is diluted with an organopolysiloxane, and the organopolysiloxane used for the dilution is a cationic polymerizable organopolysiloxane containing an epoxy group. 5. The radiation curable silicone composition according to any one of 4 above.   6. The radiation curable silicone composition according to claim 5, wherein the viscosity of the cationically polymerizable organopolysiloxane used for dilution is 2 to 200 mPa · s. The component (B) is a fluorinated alkylfluorophosphate, diaryliodonium hexafluoroantimonate, triarylsulfonium salt, triarylselenonium salt, tetraarylphosphonium salt, and aryldiazonium salt represented by the following composition formula (2) The radiation curable silicone composition according to claim 1, wherein the radiation curable silicone composition is selected from the group consisting of:

(In the formula, Rf represents an alkyl group having 1 to 8 carbon atoms in which 80 mol% or more of hydrogen atoms are substituted with fluorine atoms. P represents the number and is an integer of 1 to 5. Rf may be the same or different.   The radiation curable composition according to any one of claims 1 to 7, wherein the silicon atom substituted with a monovalent epoxy-functional organic group in component (A) is 1 to 30 mol% of all silicon atoms. Silicone composition.   A release sheet in which a cured film of the radiation curable silicone composition according to claim 1 is formed on a sheet-like substrate.