KR20230104906A - UV Curable Compositions and Uses Thereof - Google Patents

Abstract

[Problem] To provide an ultraviolet curable composition containing silicon atoms, wherein a product obtained by curing has a low refractive index and has excellent workability when applied to a substrate. [Solution] The ultraviolet curable composition of the present invention contains at least one organosilicon compound (A) having an average of at least one ultraviolet reactive functional group in one molecule, and the entire composition is measured at 25°C using an E-type viscometer. The viscosity of is 80 mPa·s or less, and the composition does not contain an organic solvent, and the cured product after curing has a refractive index of 1.45 or less measured at 25°C and a wavelength of 589 nm.

Description

UV Curable Compositions and Uses Thereof

The present invention relates to an ultraviolet curable composition curable by actinic rays, for example ultraviolet rays or electron rays, in particular an ultraviolet curable composition comprising an organosilicon compound, preferably an organosilane and/or an organopolysiloxane, in particular from It relates to an ultraviolet curable composition in which the obtained cured product has a low refractive index and is excellent in coatability. The curable composition of the present invention has a low refractive index of 1.45 or less, and is suitable as an insulating material for electronic devices and electrical devices, particularly as a material for use as a coating agent. In addition, it has excellent applicability and excellent wettability to a substrate, and is useful as an inkjet printing material.

Due to its high heat resistance and excellent chemical stability, silicone resins have been used as coating agents, potting agents, insulating materials and the like for electronic devices and electrical devices. Among silicone resins, ultraviolet curable silicone compositions have been reported so far.

Touch panels are used in various display devices such as mobile devices, industrial equipment, and car navigation systems. In order to improve the detection sensitivity, it is necessary to suppress electrical influence from a light emitting portion such as a light emitting diode (LED) or an organic EL device (OLED), and an insulating layer is usually disposed between the light emitting portion and the touch screen.

On the other hand, thin display devices such as OLED have a structure in which many functional thin layers are stacked. In recent years, studies have begun to improve the luminance of the entire display device by combining a layer with a high refractive index and a layer with a low refractive index and laminating the touch screen layer. In addition, for the purpose of improving productivity, an inkjet printing method is employed as a processing method for an organic layer. Therefore, also regarding the said insulating layer, the material which can be processed by the inkjet printing method is calculated|required.

Japanese Unexamined Patent Publication No. 2019-73588 discloses a photocurable resin composition composed of an aromatic compound containing an unsaturated bond and a compound having a mercapto group, and Japanese Unexamined Patent Publication No. 2020-26515 discloses a naphthalene compound containing an unsaturated bond as a main component A photocurable resin composition is disclosed. Any of the compositions can be applied by an inkjet method, but the cured product has a refractive index of 1.60 or more, which is characterized by a high refractive index.

On the other hand, in Japanese Patent Publication No. 6200591, a sealant for an electronic device for inkjet coating composed of a polysiloxane silicone containing an ultraviolet curable functional group and a specific curable compound, and in Japanese Laid-Open Patent Publication No. 2019-189844, a polyfunctional cation A photocurable resin composition for electronic devices comprising a polymerizable compound and a specific monofunctional cationically polymerizable compound is disclosed. Although these patent documents do not describe the refractive index after curing of the composition, when the refractive index is calculated based on the monomer structure in the curable composition, the value is 1.48 or more in any case.

Patent Document 1: Japanese Unexamined Patent Publication No. 2019-73588 Patent Document 2: Japanese Unexamined Patent Publication No. 2020-26515 Patent Document 3: Japanese Patent Publication No. 6200591 Patent Document 4: Japanese Unexamined Patent Publication No. 2019-189844

As described above, some ultraviolet curable organopolysiloxane compositions are known, but a cured product thereof has a low refractive index of 1.45 or less, and at the same time, an ultraviolet curable composition having excellent workability for application to a substrate, particularly low viscosity, is still required. It is becoming. An object of the present invention is to provide a curable composition containing silicon atoms, particularly an ultraviolet curable composition, in which a product obtained by curing has a low refractive index and has excellent workability when applied to a substrate.

In the present invention, an ultraviolet curable composition obtained by using at least one organosilicon compound (A) having an average of at least one ultraviolet reactive functional group in one molecule has a low viscosity and is excellent in workability when applied to a substrate, In addition, it was completed by discovering that the cured product exhibits a low refractive index. In particular, the curable composition of the present invention contains, as component (A), (A1) one or more organosilicon compounds, particularly organopolysiloxanes, having an average of two or more ultraviolet-reactive functional groups in one molecule, and (A2) one in one molecule. It is preferable to use at least one organosilicon compound having an ultraviolet-reactive functional group, particularly at least one organosilicon compound selected from the group consisting of organosilanes and organopolysiloxanes. As component (A) of the composition of the present invention, at least one organosilicon compound selected from the group consisting of component (A1) and component (A2) can be used in a mass ratio of 100/0 to 0/100 (A1/A2). there is. That is, components (A1) and (A2) may be used in combination as component (A) in the curable composition of the present invention, or component (A1) or component (A2) may be used alone, respectively. In the case of using only the component (A2) as the component (A), the reactive functional group capable of reacting with the UV-reactive functional group of the component (A2), preferably more than one UV-reactive functional group per molecule, preferably It is preferable to use together the compound which has 2 or more.

The present invention relates to an ultraviolet curable composition comprising an organosilicon compound, particularly an ultraviolet curable organopolysiloxane composition, wherein the composition is cured by formation of a bond by an ultraviolet curable functional group, but the curing method thereof is limited to ultraviolet irradiation. However, any method in which the ultraviolet curable functional group can cause a curing reaction may be used, and the composition of the present invention may be cured using, for example, electron beam irradiation.

The ultraviolet curable composition of the present invention contains at least one organosilicon compound (A) having at least one ultraviolet reactive functional group on average in one molecule, and the viscosity of the entire composition measured at 25°C using an E-type viscometer is 80 mPa·s or less, the composition does not contain an organic solvent, and the cured product when the composition is cured has a refractive index of 1.45 or less measured at 25°C and a wavelength of 589 nm.

In addition, unless otherwise specified in this specification, the viscosity of the material is a value measured using an E-type viscometer at 25 ° C.

It is preferable that the ultraviolet-reactive functional group which component (A) of this invention has is a cationically polymerizable reactive group. Moreover, it is preferable that a cationically polymerizable reactive group is an epoxy group containing group.

It is preferable that the ratio of component (A) in the ultraviolet curable composition of this invention is 80% or more of the mass of the whole composition.

The component (A) of the present invention comprises (A1) at least one organosilicon compound, preferably an organopolysiloxane, having an average of two or more ultraviolet-reactive functional groups per molecule, and (A2) one ultraviolet-reactive functional group per molecule. At least one organosilicon compound having a functional group, preferably one or more organosilicon compounds selected from the group consisting of organosilanes and organopolysiloxanes, in a mass ratio of 100/0 to 0/100 (A1/A2) it is desirable Thus, component (A) may be component (A1) alone, component (A2) alone, or a combination of components (A1) and (A2).

The component (A2) has an average compositional formula:

R _c R' _d SiO _(4-cd)/2 (2)

(Wherein, R is an ultraviolet reactive functional group,

R' is a group selected from monovalent hydrocarbon groups, hydroxyl groups, and alkoxy groups, excluding ultraviolet-reactive functional groups;

c and d are numbers satisfying the following conditions: 1<c+d≤4 and 0.05≤c/(c+d)≤0.25, and the number of R in the molecule is 1.)

It is preferably an organosilicon compound selected from the group consisting of linear, branched or cyclic organosilanes and organopolysiloxanes represented by .

It is preferable that the ratio of component (A2) contained in the ultraviolet curable composition of this invention is 80 mass % or more of the whole composition.

The component (A1) has an average compositional formula:

R _a R' _b SiO _(4-ab)/2 (1)

(Wherein, R is an ultraviolet reactive functional group,

R' is a group selected from monovalent hydrocarbon groups, hydroxyl groups, and alkoxy groups, excluding ultraviolet-reactive functional groups;

a and b are numbers satisfying the following conditions: 1≤a+b≤3 and 0.01≤a/(a+b)≤0.34, and have at least two R's in the molecule.)

It is preferably a linear, branched or cyclic organopolysiloxane represented by .

Component (A1) has a viscosity of 1 to 1000 mPa.s at 25°C.

The organosilicon compound of component (A2) is of the formula (3'):

[Tue 1]

(Wherein, among all R ¹ to R ⁸ groups, only one UV-reactive functional group exists in the molecule; in addition, R ¹ to R ⁸ are each independently an unsubstituted or fluorine-substituted monovalent hydrocarbon group; n is It is a numerical value of 0 or more and 3 or less) organopolysiloxane represented by;

Or, the following formula (4'):

[Tue 2]

(Wherein, each R is independently a group selected from a UV-reactive functional group and an unsubstituted or fluorine-substituted monovalent hydrocarbon group, x is an integer of 3 to 5, and has only one UV-reactive functional group in the molecule) A cyclic organopolysiloxane represented by

or the formula (5'):

RSiR' ₃ (5')

(Wherein, R is a UV-reactive functional group, and R' is a group selected from monovalent hydrocarbon groups, hydroxyl groups and alkoxy groups excluding the above-mentioned UV-reactive functional groups)

It is preferably a silicon-containing compound selected from the group consisting of organosilanes represented by &lt;RTI ID=0.0&gt;and&lt;/RTI&gt;

In addition, the organosilicon compound of the component (A1) has the following formula (3):

[Tue 3]

(Wherein, among all R ¹ to R ⁸ groups, an average of 2 or more per molecule is an ultraviolet reactive functional group; other R ¹ to R ⁸ are each independently an unsubstituted or fluorine-substituted monovalent hydrocarbon group; n is a numerical value at which the viscosity of the organopolysiloxane represented by formula (3) is 1 to 1000 mPa s at 25 ° C, and n may be 0) organopolysiloxane represented by;

Mean unit formula:

(R ₃ SiO _1/2 ) _e (R ₂ SiO _2/2 ) _f (RSiO _3/2 ) _g (SiO _4/2 ) _h (4)

(Wherein, each R is independently a group selected from a UV-reactive functional group and an unsubstituted or fluorine-substituted monovalent hydrocarbon group, and among all R, at least two are UV-reactive functional groups, and (g + h) is an amount is a number, e is 0 or a positive number, and f is a number in the range of 0 to 10.)

An organopolysiloxane represented by

Equation (5):

[Tuesday 4]

(Wherein, each R is independently a group selected from a UV-reactive functional group and an unsubstituted or fluorine-substituted monovalent hydrocarbon group, x is an integer of 3 to 10, and has at least two UV-reactive functional groups in the molecule) A cyclic organopolysiloxane represented by

and at least one organopolysiloxane having an ultraviolet reactive functional group selected from the group consisting of a mixture of two or more organopolysiloxanes arbitrarily selected from these.

It is preferable that the number of UV-reactive functional groups of the component (A1) is two on average per molecule.

It is preferable that the said component (A2) is organopolysiloxane which has one ultraviolet-reactive functional group in a molecule|numerator.

The UV-curable composition of the present invention preferably has a viscosity of 80 mPa·s or less, particularly in the range of 5 to 30 mPa·s, as measured at 25° C. using an E-type viscometer.

Component (A) is (A2) 1,1,1,3,5,5,5-heptamethyl-3-[2-(3,4-epoxycyclohexyl)ethyl]trisiloxane, or (A2) 1 ,1,1,3,5,5,5-heptamethyl-3-[2-(3,4-epoxycyclohexyl)ethyl]trisiloxane and at least one compound selected from (A1) below It is a mixture, and the mass ratio thereof is preferably in the range of 100/0 to 20/80 (A2/A1).

(A1):

1,3-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3-tetramethyldisiloxane, 1,5-bis[2-(3,4-epoxycyclohexyl) Ethyl]-1,1,3,3,5,5-hexamethyltrisiloxane, methyl(tris[2-(3,4-epoxycyclohexyl)ethyl]dimethylsiloxy)silane, tetrakis([2-( 3,4-epoxycyclohexyl)ethyl]dimethylsiloxy)silane, 1,3,5,7-tetramethyl-1,3,5,7-tetra[2-(3,4-epoxycyclohexyl)ethyl] -Cyclotetrasiloxane, 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane, 1,5-bis(3-glycidoxypropyl)-1,1, 3,3,5,5-hexamethyltrisiloxane, methyl[tris(3-glycidoxypropyl)dimethylsiloxy]silane, tetrakis[(3-glycidoxypropyl)dimethylsiloxy]silane, 1,3 ,5,7-tetramethyl-1,3,5,7-tetra(3-glycidoxypropyl)-cyclotetrasiloxane.

However, the mass ratio of the component (A2) to the component (A1) is in a particularly preferred range, and even if the ratio of the component (A1) to the total amount of the component (A2) and the component (A1) is greater than 80 mass% and is 100 mass%, The curable composition of the present invention can be obtained. That is, only component (A1) may be used as component (A).

In one preferred embodiment of the present invention, the curable composition of the present invention, as the component (A), (A2) 1,1,1,3,5,5,5-heptamethyl-3-[2-(3, 4-epoxycyclohexyl) ethyl] trisiloxane is included in the range of 50 to 95% by mass of the total composition.

In one preferred embodiment of the ultraviolet curable composition of the present invention, the composition further contains (B) a compound having one or more, preferably two or more ultraviolet reactive functional groups in one molecule and having no silicon atom, The mass ratio of component (B) to the sum of component (A1), component (A2) and component (B) is less than 20%.

In the case of using the above component (B), component (A) may be either only component (A1), only component (A2), or a combination of component (A1) and component (A2), but as component (A) When the component (A2) having one ultraviolet-reactive functional group in one molecule is used and the component (A1) is not used, it is particularly preferable to use the component (B).

The present invention also provides an insulating coating agent containing the ultraviolet curable composition. The ultraviolet curable composition of the present invention is useful as an insulating coating agent.

The present invention also provides a method of using the cured product of the ultraviolet curable composition as an insulating coating layer.

The present invention also provides a display device including a layer made of a cured product of the UV curable composition, for example, a liquid crystal display or an organic EL display.

Hereinafter, the configuration of the present invention will be described in more detail.

The ultraviolet curable composition of the present invention contains, as an essential component, at least one organosilicon compound (component (A)) having at least one ultraviolet reactive functional group on average in one molecule, and, if necessary, a photocationic polymerization initiator and various additives. It may contain components selected from. However, the curable composition of the present invention is characterized in that it does not contain an organic solvent.

In this specification, the term "organosilicon compound" is used as a term meaning a concept including organosilanes, organosiloxane oligomers, and organopolysiloxanes.

In the present specification, the term "polysiloxane" refers to a siloxane unit (Si-O) having a degree of polymerization of 2 or more, that is, an average of 2 or more Si-O bonds per molecule, and polysiloxanes include disiloxane, trisiloxane, and tetrasiloxane. Siloxane oligomers, such as siloxane, and siloxane polymers with a higher degree of polymerization are contained.

Component (A) is selected from (A1) at least one organosilicon compound having an average of two or more ultraviolet-reactive functional groups per molecule, and (A2) at least one organosilicon compound having one ultraviolet-reactive functional group per molecule. It is one type or two or more types, and the ratio of (A1) component / (A2) component is selectable in the range of 100/0 to 0/100. Here, when component (A) is a component having only one ultraviolet-reactive functional group in one molecule (for example, composed only of component (A2)), in order to advance the crosslinking reaction of the entire composition, (B) one molecule It is preferable to include as a cross-linking component a compound having one or more, preferably two or more ultraviolet-reactive functional groups and no silicon atom in the composition. In addition, when component (A) contains at least one organosilicon compound having an average of two or more ultraviolet-reactive functional groups in one molecule (A1), the crosslinking reaction proceeds throughout the composition even if component (B) does not exist. do. That is, component (B) is a crosslinking component that can be used arbitrarily depending on the type of component (A).

[Component (A): an organosilicon compound having an average of one or more ultraviolet-reactive functional groups in one molecule]

The organosilicon compound having a UV-reactive functional group used as component (A), preferably at least one compound selected from organosilanes and organopolysiloxanes, has an average of at least one ultraviolet-reactive functional group per molecule, and this Its molecular structure may be arbitrary as long as the purpose can be achieved. The UV-reactive functional group of component (A) is particularly preferably a cationically polymerizable functional group, and more preferably an epoxy group-containing group.

Component (A) is more specifically preferably one or more organosilicon compounds selected from the group consisting of component (A1) and component (A2) described below.

Component (A1) and component (A2) may each be used alone or in combination as component (A), and the ratio of component (A1) to component (A2) is 100/0 to 0/100 (A1/A2) may be the mass ratio of It is preferable that this mass ratio is 100/20 - 0/100 (A1/A2). An aspect using only the component (A2) as the component (A) is also one of the preferable aspects.

Component (A) preferably has a viscosity of 1 to 1000 mPa·s at 25°C, more preferably 1 to 500 mPa·s, particularly preferably 1 to 100 mPa·s, and 1 to 50 mPa·s. s is most preferred.

In addition, component (A) contains 1 to 20, preferably 1 to 4, silicon atoms per molecule.

<Component (A1): an organosilicon compound having an average of 2 or more ultraviolet-reactive functional groups in one molecule>

The organosilicon compound of component (A1) has the following average compositional formula:

R _a R' _b SiO _(4-ab)/2 (1)

It is a linear, branched or cyclic organopolysiloxane represented by , preferably a linear or branched, particularly preferably a linear organopolysiloxane.

In formula (1),

R is an ultraviolet reactive functional group,

R' is a group selected from monovalent hydrocarbon groups, hydroxyl groups and alkoxy groups, excluding ultraviolet-reactive functional groups;

a and b satisfy the following conditions: 1≤a+b≤3 and 0.01≤a/(a+b)≤0.34, preferably 2≤a+b≤3 and 0.05≤a/(a+b)≤0.34 is a satisfactory number.

The ultraviolet-reactive functional group represented by R in formula (1) is an organic group capable of generating bonds with each other by irradiation of ultraviolet rays in the presence or absence of a photoinitiator. Examples of the ultraviolet reactive functional group include radical polymerizable groups and cationic polymerizable groups. The radical polymerizable group is not particularly limited as long as it is a functional group capable of forming a new bond, particularly a bond between radical polymerizable groups, depending on the radical reaction mechanism, but includes, for example, an acrylic group, a methacrylic group, a maleimide group, and any of these groups. organic groups can be mentioned. Specific examples include groups such as acryloxypropyl, methacryloxypropyl, acrylamide propyl, methacrylamide propyl, and 3-(N-maleimide)propyl as the radical polymerizable group. As the cationic polymerizable group, groups such as vinyl ether group, epoxy group-containing group, oxetane group-containing group, for example, CH ₂ =CH-O-(CH ₂ )n- (n is an integer of 3 to 20), glyc groups such as cidyloxy-(CH ₂ ) _n - (n is an integer of 3 to 20) and 3,4-epoxycyclohexyl- (CH ₂ ) _n - (n is an integer of 2 to 20); there is.

It is preferable that the ultraviolet-reactive functional group is an epoxy group-containing group. Particularly preferred groups include glycidyloxyalkyl groups such as glycidyloxypropyl groups and epoxycyclohexylalkyl groups, particularly 3,4-epoxycyclohexylethyl groups. The linear, branched or cyclic organopolysiloxane represented by the average compositional formula has at least two ultraviolet-reactive functional groups (R) per molecule on average. The number of ultraviolet curable groups per molecule is, on average, preferably 2 to 6, still more preferably 2 to 4, particularly preferably 2 to 3, and most preferably 2.

R' is a monovalent hydrocarbon group, which includes unsubstituted monovalent hydrocarbon groups and fluorine-substituted monovalent hydrocarbon groups. The unsubstituted or fluorine-substituted monovalent hydrocarbon group is preferably a group selected from unsubstituted or fluorine-substituted alkyl, cycloalkyl, arylalkyl and aryl groups having 1 to 20 carbon atoms. Examples of the alkyl group include groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, pentyl, and octyl, and a methyl group is particularly preferred. As said cycloalkyl group, cyclopentyl, cyclohexyl, etc. are mentioned. As said arylalkyl group, benzyl, a phenylethyl group, etc. are mentioned. As said aryl group, a phenyl group, a naphthyl group, etc. are mentioned. Examples of monovalent hydrocarbon groups substituted with fluorine include 3,3,3-trifluoropropyl and 3,3,4,4,5,5,6,6,6-nonafluorohexyl groups. As the monovalent hydrocarbon group substituted with fluorine, a 3,3,3-trifluoropropyl group is preferable.

The organopolysiloxane represented by the formula (1) has a viscosity at 25°C of 1 to 1000 mPa·s, 1 to 500 mPa·s, or 1 to 100 mPa·s, most preferably 1 to 50 mPa·s. is s. The viscosity of the organopolysiloxane can be adjusted by changing the ratio and molecular weight of a and b in formula (1).

The organopolysiloxane represented by the formula (1) has preferably 2 to 20 silicon atoms, still more preferably 2 to 5 silicon atoms, on average per molecule.

In one preferred embodiment, the organopolysiloxane of component (A1) is

Equation (3):

[Tuesday 5]

is a compound represented by

Similar to the compound represented by the above formula (1), the organopolysiloxane represented by the formula (3) has an average of two or more ultraviolet-reactive functional groups per molecule. In Formula (3), among all the R ¹ to R ⁸ groups, two or more on average are ultraviolet-reactive functional groups per molecule. The ultraviolet-reactive functional groups are organic groups capable of generating bonds with each other by irradiation of ultraviolet rays in the presence or absence of a photoinitiator. Examples of the ultraviolet reactive functional group include radical polymerizable groups and cationic polymerizable groups. The radical polymerizable group is not particularly limited as long as it is a functional group capable of forming a new bond, particularly a bond between radical polymerizable groups, by a radical reaction mechanism, but includes, for example, an acrylic group, a methacrylic group, a maleimide group, and any of these groups. An organic group can be mentioned. Specific examples include groups such as acryloxypropyl, methacryloxypropyl, acrylamide propyl, methacrylamide propyl, and 3-(N-maleimide)propyl as the radical polymerizable group. As the cationic polymerizable group, groups such as vinyl ether group, epoxy group-containing group, oxetane group-containing group, for example, CH ₂ =CH-O-(CH ₂ )n- (n is an integer of 3 to 20), glyc groups such as cidyloxy-(CH ₂ ) _n - (n is an integer of 3 to 20) and 3,4-epoxycyclohexyl- (CH ₂ ) _n - (n is an integer of 2 to 20); there is.

It is preferable that it is 1 or more types of epoxy group containing groups as an ultraviolet-ray reactive functional group. As a particularly preferable group, a glycidyloxyalkyl group, particularly a 3-glycidyloxypropyl group, and an epoxycyclohexylalkyl group, particularly a 3,4-epoxycyclohexylethyl group, are exemplified.

In formula (3), R ¹ to R ⁸ other than the UV-reactive functional group are each independently an unsubstituted or fluorine-substituted monovalent hydrocarbon group, preferably an unsubstituted or fluorine-substituted alkyl group having 1 to 20 carbon atoms. , a group selected from cycloalkyl, arylalkyl and aryl groups. Examples of the alkyl group include groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, pentyl, and octyl, and a methyl group is particularly preferred. As said cycloalkyl group, cyclopentyl, cyclohexyl, etc. are mentioned. Examples of the arylalkyl group include benzyl and phenylethyl groups. A phenyl group, a naphthyl group, etc. are mentioned as said aryl group. Examples of monovalent hydrocarbon groups substituted with fluorine include 3,3,3-trifluoropropyl and 3,3,4,4,5,5,6,6,6-nonafluorohexyl groups. As the monovalent hydrocarbon group substituted with fluorine, a 3,3,3-trifluoropropyl group is preferable. By introduce|transducing a fluorine atom into the organopolysiloxane of Formula (3), the refractive index of the hardened|cured material obtained from the composition of this invention may be further reduced.

The number of UV-reactive functional groups of the organopolysiloxane of the formula (3) as component (A1) is 2 to 6, preferably 2 to 5, still more preferably 2 to 4, particularly preferably per molecule on average. 2 to 3, most preferably 2.

In particular, it is preferable that one of R ₁ to R ₃ and one of R ₆ to R ₈ in formula (3) is an ultraviolet reactive functional group. Moreover, it is particularly preferable that only one of R ₁ to R ₃ and only one of R ₆ to R ₈ in formula (3) are ultraviolet-reactive functional groups.

n in formula (3) is such that the organopolysiloxane represented by formula (3) has a viscosity at 25°C of preferably 1 to 1000 mPa·s, still more preferably 1 to 500 mPa·s, particularly preferably 1 ~ 100 mPa·s, most preferably a value of 1 to 50 mPa·s. A person skilled in the art can easily determine the value of n without excessive trial and error so that the viscosity of the organopolysiloxane of formula (3) falls within the aforementioned viscosity range. However, in general, it is preferable that the number of silicon atoms per molecule is 2 to 20, particularly 2 to 5, so that the compound of formula (3) has a desired viscosity.

The organopolysiloxane of formula (3) can be used alone or as a mixture of two or more. When two or more organopolysiloxanes are used as a mixture, it is preferable that the viscosity of the mixture at 25 DEG C is the above-mentioned viscosity.

Moreover, the organopolysiloxane represented by the following average unit formula (4) may be sufficient as the compound of said formula (1).

Mean unit formula:

(R ₃ SiO _1/2 ) _e (R ₂ SiO _2/2 ) _f (RSiO _3/2 ) _g (SiO _4/2 ) _h (4)

In formula (4), each R is independently a group selected from an ultraviolet reactive functional group and an unsubstituted or fluorine-substituted monovalent hydrocarbon group, at least two of all R are ultraviolet reactive functional groups, and (g + h) is A positive number, e is 0 or a positive number, and f is a number in the range of 0 to 10.

The UV-reactive functional group and the monovalent hydrocarbon group are as defined for Formula (1) above. In addition, the preferred viscosity of the organopolysiloxane represented by the formula (4) is also as defined for the organopolysiloxane represented by the formula (1) above.

The number of UV-reactive functional groups of the organopolysiloxane represented by formula (4) per molecule is preferably 2 to 5, still more preferably 2 to 4, particularly preferably 2 to 3, and most preferably It is two.

The organopolysiloxane represented by formula (4) preferably has 2 to 20, particularly 2 to 5 silicon atoms per molecule.

Specific examples of the organopolysiloxane represented by the formula (1), particularly formula (3) or (4), include 1,3-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1; 3,3-tetramethyldisiloxane, 1,5-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5-hexamethyltrisiloxane, methyl (tris[ 2-(3,4-epoxycyclohexyl)ethyl]dimethylsiloxy)silane, tetrakis([2-(3,4-epoxycyclohexyl)ethyl]dimethylsiloxy)silane, 1,3-bis(3- glycidoxypropyl) -1,1,3,3-tetramethyldisiloxane, 1,5-bis (3-glycidoxypropyl) -1,1,3,3,5,5-hexamethyltrisiloxane, Methyl[tris(3-glycidoxypropyl)dimethylsiloxy]silane, tetrakis[(3-glycidoxypropyl)dimethylsiloxy]silane, both terminals (3,4-epoxycyclohexylethyldimethylsilyl)-poly Dimethylsiloxane, both ends (3-glycidoxypropyldimethylsilyl)-polydimethylsiloxane, both ends trimethylsilyl-dimethylsiloxy/(methyl-3,4-epoxycyclohexylethylsiloxy) copolymer, both ends trimethylsilyl -Dimethylsiloxy/(methyl-3-glycidoxypropylsiloxy) copolymer, both ends (3,4-epoxycyclohexylethyldimethylsilyl)-dimethylsiloxy/(methyl-3,4-epoxycyclohexylethyl siloxy) copolymer, and (3-glycidoxypropyldimethylsilyl)-dimethylsiloxy/(methyl-3-glycidoxypropylsiloxy) copolymer at both ends.

In addition, the compound of the formula (1) is the following formula (5):

[Tue 6]

(Wherein, each R is independently a group selected from a UV-reactive functional group and an unsubstituted or fluorine-substituted monovalent hydrocarbon group, x is an integer of 3 to 10, and has at least two UV-reactive functional groups in the molecule) It may also be a cyclic organopolysiloxane represented by

The UV-reactive functional group and the unsubstituted or fluorine-substituted monovalent hydrocarbon group represented by R in formula (5) are as defined for formula (1) above.

In addition, the preferred viscosity of the organopolysiloxane represented by the formula (5) is also as defined for the organopolysiloxane represented by the formula (1) above.

Specific examples of the cyclic organopolysiloxane represented by formula (5) include 1,3,5-trimethyl-1,3,5-tri[2-(3,4-epoxycyclohexyl)ethyl]cyclotrisiloxane, 1, 3,5-trimethyl-1,3,5-tri(3-glycidoxypropyl)cyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetra[2-(3 ,4-epoxycyclohexyl)ethyl]cyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetra(3-glycidoxypropyl)cyclotetrasiloxane, 1,3,5 ,7,9-pentamethyl-1,3,5,7,9-penta[2-(3,4-epoxycyclohexyl)ethyl]cyclopentasiloxane, 1,3,5,7,9-pentamethyl- and 1,3,5,7,9-penta(3-glycidoxypropyl)cyclopentasiloxane.

The organopolysiloxanes represented by the formulas (1) and (3) to (5) described above can be used singly or in combination of two or more arbitrarily as the component (A1).

As component (A1), in particular, one or more organosilicon compounds selected from the group consisting of organopolysiloxanes represented by the above formula (3), cyclic organopolysiloxanes represented by formula (5), and combinations thereof are used. it is desirable

The viscosity of component (A1) as a whole is preferably 1 to 1000 mPa s, 1 to 500 mPa s, 1 to 100 mPa s, preferably 1 to 50 mPa s at 25 ° C. .

When component (A1) is used in combination with component (A2) and/or component (B), even if the viscosity of component (A1) is high to some extent, component (A2) and/or component (B) have low viscosity. By using a compound, the composition as a whole can be set to a desired viscosity.

Particularly preferred compounds as component (A1) are 1,3-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3-tetramethyldisiloxane, 1,5-bis[2- (3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5-hexamethyltrisiloxane, methyl (tris[2-(3,4-epoxycyclohexyl)ethyl]dimethylsiloxy) Silane, tetrakis([2-(3,4-epoxycyclohexyl)ethyl]dimethylsiloxy)silane, 1,3,5,7-tetramethyl-1,3,5,7-tetra[2-(3 ,4-epoxycyclohexyl)ethyl]-cyclotetrasiloxane, 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane, 1,5-bis(3-glycidoxypropyl) Cydoxypropyl)-1,1,3,3,5,5-hexamethyltrisiloxane, methyl[tris(3-glycidoxypropyl)dimethylsiloxy]silane, tetrakis[(3-glycidoxypropyl) dimethylsiloxy]silane and 1,3,5,7-tetramethyl-1,3,5,7-tetra(3-glycidoxypropyl)-cyclotetrasiloxane, or two or more compounds selected from the group consisting of It is a combination of compounds.

[Component (A2): an organosilicon compound having one ultraviolet-reactive functional group in one molecule]

Component (A2) is an organosilicon compound having an organosilane or organopolysiloxane skeleton with one ultraviolet-reactive functional group per molecule, mainly controlling the crosslinking density of a cured product obtained from the composition of the present invention to adjust physical properties of the cured product. And, at the same time, it has the effect of reducing the viscosity of the composition. Its molecular structure may be arbitrary as long as this object can be achieved. As an example, the organosilicon compound of component (A2) is

The following average composition formula;

R _c R' _d SiO _(4-cd)/2 (2)

(Wherein, R is an ultraviolet curable functional group,

R' is a group selected from monovalent hydrocarbon groups, hydroxyl groups and alkoxy groups, excluding ultraviolet curable functional groups;

c and d are numbers satisfying the following conditions: 1≤c+d≤4 and 0.05≤c/(c+d)≤0.25. Also, the number of R in the molecule is 1.)

It is an organosilane represented by , or a linear, branched or cyclic organopolysiloxane. One type selected from the group consisting of these organosilanes and organopolysiloxanes may be used, or any two or more types may be used in combination.

The ultraviolet-reactive functional group represented by R in formula (2) is an organic group capable of generating bonds with each other by irradiation of ultraviolet rays in the presence or absence of a photoinitiator. Examples of the ultraviolet reactive functional group include radical polymerizable groups and cationic polymerizable groups. The radical polymerizable group is not particularly limited as long as it is a functional group capable of forming a new bond, particularly a bond between radical polymerizable groups, by a radical reaction mechanism, but includes, for example, an acrylic group, a methacrylic group, a maleimide group, and any of these groups. organic groups can be mentioned. Specific examples include groups such as acryloxypropyl, methacryloxypropyl, acrylamide propyl, methacrylamide propyl, and 3-(N-maleimide)propyl as the radical polymerizable group. As the cationic polymerizable group, groups such as vinyl ether group, epoxy group-containing group, oxetane group-containing group, for example, CH ₂ =CH-O-(CH ₂ )n- (n is an integer of 3 to 20), glyc groups such as cidyloxy-(CH ₂ ) _n - (n is an integer of 3 to 20) and 3,4-epoxycyclohexyl- (CH ₂ ) _n - (n is an integer of 2 to 20); there is.

It is preferable that it is 1 or more types of epoxy group containing groups as an ultraviolet-ray reactive functional group. As a particularly preferable group, a glycidyloxyalkyl group, especially a glycidyloxypropyl group, an epoxycyclohexylalkyl group, especially a 3,4-epoxycyclohexylethyl group is mentioned. The organosilicon compound represented by the above average compositional formula has one ultraviolet-reactive functional group (R) in one molecule.

The monovalent hydrocarbon groups represented by R' in formula (2) are independently groups selected from the group consisting of unsubstituted monovalent hydrocarbon groups and fluorine-substituted monovalent hydrocarbon groups. The unsubstituted or fluorine-substituted monovalent hydrocarbon group is preferably a group selected from unsubstituted or fluorine-substituted alkyl, cycloalkyl, arylalkyl and aryl groups having 1 to 20 carbon atoms. Examples of the alkyl group include groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, pentyl, and octyl, and a methyl group is particularly preferred. As said cycloalkyl group, cyclopentyl, cyclohexyl, etc. are mentioned. As said arylalkyl group, benzyl, a phenylethyl group, etc. are mentioned. As said aryl group, a phenyl group, a naphthyl group, etc. are mentioned. Examples of monovalent hydrocarbon groups substituted with fluorine include 3,3,3-trifluoropropyl and 3,3,4,4,5,5,6,6,6-nonafluorohexyl groups. As the monovalent hydrocarbon group substituted with fluorine, a 3,3,3-trifluoropropyl group is preferable. By introduce|transducing a fluorine atom into organopolysiloxane of Formula (2), the refractive index of the hardened|cured material obtained from the composition of this invention may be further reduced.

The organosilicon compound represented by the formula (2) preferably has a viscosity of 1 to 500 mPa s at 25°C, more preferably 1 to 100 mPa s, and more preferably 1 to 50 mPa s. particularly preferred. By changing the ratio and molecular weight of c and d in formula (2), the viscosity of the organosilicon compound can be adjusted.

The organic silicon compound represented by the formula (2) is preferably a compound having 1 to 20, preferably 1 to 4, silicon atoms per molecule.

In one preferred embodiment, the organosilicon compound of component (A2) is

Formula (3'):

[Tue 7]

It is an organopolysiloxane compound represented by

Similar to the compound represented by the above formula (2), in the organopolysiloxane represented by the formula (3'), one of all R ¹ to R ⁸ groups is a UV-reactive functional group.

Like the compound represented by the above formula (2), the ultraviolet-reactive functional groups are organic groups capable of generating bonds with each other by irradiation of ultraviolet rays in the presence or absence of a photoinitiator. Examples of the ultraviolet curable functional group include radical polymerizable groups and cationic polymerizable groups. The radical polymerizable group is not particularly limited as long as it is a functional group capable of forming a new bond, particularly a bond between radical polymerizable groups, by a radical reaction mechanism, but includes, for example, an acrylic group, a methacrylic group, a maleimide group, and any of these groups. organic groups can be mentioned. Specific examples include groups such as acryloxypropyl, methacryloxypropyl, acrylamide propyl, methacrylamide propyl, and 3-(N-maleimide)propyl as the radical polymerizable group. As the cationic polymerizable group, groups such as vinyl ether group, epoxy group-containing group, oxetane group-containing group, for example, CH ₂ =CH-O-(CH ₂ )n- (n is an integer of 3 to 20), glyc groups such as cidyloxy-(CH ₂ ) _n - (n is an integer of 3 to 20) and 3,4-epoxycyclohexyl- (CH ₂ ) _n - (n is an integer of 2 to 20); there is.

It is preferable that it is 1 or more types of epoxy group containing groups as an ultraviolet-ray reactive functional group. As a particularly preferable group, a glycidyloxyalkyl group, such as a glycidyloxypropyl group, an epoxycyclohexylalkyl group, especially a 3,4-epoxycyclohexylethyl group is mentioned.

In formula (3'), R ¹ to R ⁸ other than the UV-reactive functional group are each independently an unsubstituted or fluorine-substituted monovalent hydrocarbon group, preferably an unsubstituted or fluorine-substituted monovalent hydrocarbon group having 1 to 20 carbon atoms. It is a group selected from alkyl, cycloalkyl, arylalkyl and aryl groups. Examples of the alkyl group include groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, pentyl, and octyl, and a methyl group is particularly preferred. As said cycloalkyl group, cyclopentyl, cyclohexyl, etc. are mentioned. As said arylalkyl group, benzyl, a phenylethyl group, etc. are mentioned. As said aryl group, a phenyl group, a naphthyl group, etc. are mentioned. Examples of the monovalent hydrocarbon group substituted with fluorine include 3,3,3-trifluoropropyl and 3,3,4,4,5,5,6,6,6-nonafluorohexyl groups. As the monovalent hydrocarbon group substituted with fluorine, a 3,3,3-trifluoropropyl group is preferable. By introduce|transducing a fluorine atom into the organopolysiloxane of Formula (3'), the refractive index of the hardened|cured material obtained from the composition of this invention can be further reduced in some cases.

The organopolysiloxane represented by Formula (3') has one ultraviolet-reactive functional group in one molecule.

There is no restriction on the position of the UV-curable functional group in the organopolysiloxane represented by formula (3'), and the molecular end group, namely, one of R ₁ to R ₃ or R ₆ to R ₈ may be an UV-reactive functional group. Alternatively, only one of the non-terminal groups R ₄ to R ₅ in formula (3') may be made into an ultraviolet reactive functional group.

n in formula (3') is preferably a value such that the organopolysiloxane represented by formula (3') has a viscosity at 25°C of 1 to 500 mPa·s, and more preferably a value of 1 to 100 mPa·s. It is preferable, and it is especially preferable that it is a value used as 1-50 mPa*s. A person skilled in the art can easily determine the value of n without excessive trial and error so that the viscosity of the organopolysiloxane of formula (3') falls within the aforementioned viscosity range. In general, the number of silicon atoms per molecule is preferably 2 to 20, and more preferably 2 to 5 so that the compound of formula (3') has a desired viscosity.

The organopolysiloxane of formula (3') can be used singly or as a mixture of two or more. When two or more organopolysiloxanes are used as a mixture, the viscosity of the mixture at 25°C is 1 to 500 mPa s, preferably 1 to 100 mPa s, still more preferably 1 to 50 mPa s, Especially preferably, it is 5-20 mPa*s.

Specific examples of the organopolysiloxane having one ultraviolet-reactive functional group in the molecule represented by formula (3') include 1-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3, 3-pentamethyldisiloxane, 1-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3,5,5,5-heptamethyltrisiloxane, 3-[2-(3 ,4-epoxycyclohexyl)ethyl]-1,1,1,3,5,5,5-heptamethyltrisiloxane, and 1-[2-(3,4-epoxycyclohexyl)ethyl]-1,1 ,3,3,5,5,7,7,7-nonamethyltetrasiloxane, 1-(3-glycidoxypropyl)-1,1,3,3,3-pentamethyldisiloxane, 1-(3 -Glycidoxypropyl)-1,1,3,3,5,5,5-heptamethyltrisiloxane, 3-(3-glycidoxypropyl)-1,1,1,3,5,5,5 -heptamethyltrisiloxane, and 1-(3-glycidoxypropyl)-1,1,3,3,5,5,7,7,7-nonamethyltetrasiloxane.

Moreover, the organosilicon compound of said formula (2) may be a cyclic organopolysiloxane represented by following formula (4').

ceremony:

[Tue 8]

In formula (4'), each R is independently a group selected from a UV-reactive functional group and an unsubstituted or fluorine-substituted monovalent hydrocarbon group, x is an integer of 3 to 5, and only one UV-reactive functional group in the molecule. have

The ultraviolet reactive functional group and the monovalent hydrocarbon group are as defined for the above formula (2).

The preferred viscosity of the cyclic organopolysiloxane represented by the formula (4') is also as defined for the organopolysiloxane represented by the formula (2) above. Therefore, the viscosity at 25°C is preferably 1 to 500 mPa·s, more preferably 1 to 100 mPa·s, and particularly preferably 1 to 50 mPa·s.

Specific examples of the cyclic organopolysiloxane represented by the formula (4') include [2-(3,4-epoxycyclohexyl)ethyl]-pentamethylcyclotrisiloxane, [2-(3,4-epoxycyclohexyl)ethyl ]-Heptamethylcyclotetrasiloxane, [2-(3,4-epoxycyclohexyl)ethyl]-nonamethylcyclopentasiloxane, 3-glycidoxypropyl-pentamethylcyclotrisiloxane, 3-glycidoxypropyl-hepta methylcyclotetrasiloxane and 3-glycidoxypropyl-nonamethylcyclopentasiloxane.

Moreover, the organosilane represented by following formula (5') may be sufficient as component (A2).

Formula: RSiR' ₃ (5')

In formula (5'), R is an ultraviolet-reactive functional group, and R' is a group selected from monovalent hydrocarbon groups, hydroxyl groups, and alkoxy groups excluding ultraviolet-reactive functional groups.

The UV-reactive functional group and the monovalent hydrocarbon group are as defined in Formula (2) above, and the alkoxy group is an alkoxy group having 1 to 20 carbon atoms, preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, or 5 carbon atoms. It is a cycloalkyl group of ~20. Specifically, a methoxy group, an ethoxy group, an isopropoxy group, a cyclopentyl group, or a cyclohexyl group is preferable.

In addition, the preferable viscosity of organosilane represented by formula (5') is the same as the viscosity previously defined for the organopolysiloxane represented by formula (2). Therefore, the viscosity at 25°C is preferably 1 to 500 mPa·s, more preferably 1 to 100 mPa·s, and particularly preferably 1 to 50 mPa·s.

Specific examples of the organosilane represented by the formula (5') include [2-(3,4-epoxycyclohexyl)ethyl]triethylsilane and [2-(3,4-epoxycyclohexyl)ethyl]dimethylphenylsilane. , [2-(3,4-epoxycyclohexyl)ethyl]dimethyloctylsilane, [2-(3,4-epoxycyclohexyl)ethyl]dimethylcyclohexylsilane, [2-(3,4-epoxycyclohexyl) Ethyl]trihexylsilane, [2-(3,4-epoxycyclohexyl)ethyl]tributylsilane, 3-glycidoxypropyltriethylsilane, 3-glycidoxypropyldimethylphenylsilane, 3-glycidoxypropyl Dimethyloctylsilane, 3-glycidoxypropyl dimethylcyclohexylsilane, 3-glycidoxypropyltrihexylsilane, and 3-glycidoxypropyltributylsilane.

The organosilicon compounds represented by the above formulas (2), (3'), (4') or (5') can be used individually by one type or in combination of two or more types arbitrarily. That is, an organosilicon compound represented by formula (2), (3'), (4') or (5') and a mixture of two or more types arbitrarily selected from them can be used as component (A2) of the composition of the present invention. there is.

As component (A2), it is preferable to use an organosiloxane compound selected from organopolysiloxanes represented by formula (3'), cyclic organopolysiloxanes represented by formula (4'), and combinations thereof.

Particular preference is given to using 1,1,1,3,5,5,5-heptamethyl-3-[2-(3,4-epoxycyclohexyl)ethyl]trisiloxane as component (A2).

As the component (A), only the component (A1) or only the component (A2) may be used, or the component (A1) and the component (A2) may be used together, and the mass ratio of the components (A1) and (A2) may be any mass ratio in the range of 100/0 to 0/100 (A1/A2), but the ratio of component (A2) is 50% by mass or more relative to 100% by mass of the total amount of components (A1) and (A2) , preferably 65% by mass or more, still more preferably 70% by mass or more, and most preferably 75% by mass or more.

In the curable composition of the present invention, the ratio of component (A) to the total mass of the composition is 80% by mass or more, preferably 85% by mass or more, and preferably 90% by mass or more. The curable composition of the present invention may consist only of component (A), and therefore the upper limit of this ratio is 100% by mass.

When component (A1) and component (A2) are used together as component (A), the following compounds as component (A1):

1,3-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3-tetramethyldisiloxane, 1,5-bis[2-(3,4-epoxycyclohexyl) Ethyl]-1,1,3,3,5,5-hexamethyltrisiloxane, methyl(tris[2-(3,4-epoxycyclohexyl)ethyl]dimethylsiloxy)silane, tetrakis([2-( 3,4-epoxycyclohexyl)ethyl]dimethylsiloxy)silane, 1,3,5,7-tetramethyl-1,3,5,7-tetra[2-(3,4-epoxycyclohexyl)ethyl] -Cyclotetrasiloxane, 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane, 1,5-bis(3-glycidoxypropyl)-1,1, 3,3,5,5-hexamethyltrisiloxane, methyl[tris(3-glycidoxypropyl)dimethylsiloxy]silane, tetrakis[(3-glycidoxypropyl)dimethylsiloxy]silane and 1,3 ,5,7-tetramethyl-1,3,5,7-tetra(3-glycidoxypropyl)-cyclotetrasiloxane

One compound or a combination of two or more compounds selected from the group consisting of 1,1,1,3,5,5,5-heptamethyl-3-[2-(3,4) as component (A2) -Epoxycyclohexyl)ethyl]trisiloxane is preferably used in combination, and the mass ratio of component (A2) to component (A1) is preferably 100/0 to 20/80 (A2/A1), still more preferably 100/A1. It is a range of 0 to 50/50, particularly preferably 100/0 to 75/25. However, the mass ratio of the component (A1) and the component (A2) is a value defining a particularly preferable range, and the curable composition of the present invention can also be prepared using only the component (A1).

The curable composition of the present invention contains (A2) 1,1,1,3,5,5,5-heptamethyl-3-[2-(3,4-epoxycyclohexyl)ethyl]trisiloxane as component (A). When included, the amount thereof is within the range of 50 to 95%, preferably 65 to 95%, and even more preferably 75 to 95% of the total mass of the curable composition.

As the component (A), when the component (A1) and the component (A2) are used together, it is preferable that the UV-reactive functional group of the component (A1) and the UV-reactive functional group of the component (A2) are the same reactive functional group. do. Therefore, when the UV-reactive functional group of component (A1) is a radical polymerizable group, it is preferable that the UV-reactive functional group of component (A2) is also a radical polymerizable group. Moreover, when the ultraviolet-reactive functional group which component (A1) has is a cationic polymerizable group, it is preferable that the ultraviolet-ray reactive functional group which component (A2) has is also a cationic polymerizable group. It is preferable that both components (A1) and (A2) have a cationically polymerizable reactive group as an ultraviolet-reactive functional group.

[Component (B): A compound having at least one ultraviolet-reactive functional group in one molecule and not having a silicon atom]

In the curable composition of the present invention, in addition to the above component (A) or component (A1) and/or component (A2), a compound (component (B )) may be further added. In particular, when using only the component (A2) as the component (A), it is preferable to use the component (B) in addition to the component (A2). The curability of the composition may be improved by using the component (B) in combination with the component (A2).

The UV-reactive functional group of component (B) may be the same as those listed with respect to components (A), (A1) and (A2). The difference between component (B) and component (A), component (A1) and component (A2) is that the latter has a silicon atom in its molecule, whereas component (B) has no silicon atom in its molecule. The chemical structure thereof is not particularly limited, and any compound can be used as component (B) as long as it does not contain a silicon atom in the molecule and has at least one ultraviolet-reactive functional group described above in the molecule.

As the component (B), an organic compound having an epoxy group in the molecule, particularly a compound having an epoxy group and not having a cyclic structure can be used. Preferred specific examples of component (B) include 2-ethylhexyl glycidyl ether, glycidyl lauryl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl diyl ether, 1,2-epoxydecane, 1,2-epoxydodecane and 1,7-octadiene diepoxide. As component (B), 1,2-epoxydodecane, 1,7-octadiene diepoxide, and 1,4-butanediol diglycidyl ether are particularly preferred.

As component (B), an organic compound having a radically polymerizable reactive group as an ultraviolet-reactive functional group in a molecule is also exemplified. Specific examples thereof include known (meth)acrylic acid ester compounds having one radical polymerizable reactive group in the molecule and (meth)acrylic acid ester compounds having two or more radically polymerizable reactive groups.

It is preferable that the ultraviolet-reactive functional group of component (B) is the same functional group as the ultraviolet-reactive functional group of component (A) or component (A1) and/or component (A2) used in combination with component (B). Therefore, for example, when the UV-reactive functional group of component (A1) and/or component (A2) is a radical polymerizable group, it is preferable that the UV-reactive functional group of component (B) is also a radical polymerizable group. Moreover, when the ultraviolet-reactive functional group which component (A1) and/or component (A2) has is a cationic polymerizable group, it is preferable that the ultraviolet-ray reactive functional group which component (B) has is also a cationic polymerizable group. It is preferable that component (A1) and/or component (A2) and component (B) all have a cationically polymerizable reactive group as an ultraviolet-reactive functional group, especially preferably an epoxy group.

The viscosity of component (B) is preferably 1 to 1000 mPa s, even more preferably 1 to 500 mPa s, particularly preferably 1 to 100 mPa s, and most preferably 1 to 50 mPa s at 25°C. mPa·s.

In the case of using component (B) in addition to the above components (A1) and/or (A2), the component ( The mass proportion of B) is less than 20%, preferably less than 10% and particularly preferably less than 5%.

[Composition not containing organic solvent]

In this specification, not containing an organic solvent means that the content of the organic solvent is less than 0.05% by mass of the total composition, preferably below the analysis limit using an analysis method such as gas chromatography. In the present invention, by adjusting the molecular structure and molecular weight of component (A) and component (B), a desired viscosity can be achieved without using an organic solvent.

[Photoinitiator]

In addition to the said component (A), a photoinitiator can be added to the ultraviolet curable composition of this invention as needed. In that case, when the UV-reactive functional group of component (A) is a cationically polymerizable functional group containing epoxy or vinyl ether, a photocationic polymerization initiator is used as the photopolymerization initiator. As the photocationic polymerization initiator, a compound capable of generating a Broensted acid or a Lewis acid by irradiation with ultraviolet rays or electron beams, a so-called photoacid generator, is known. It is known to cause reaction between cationically polymerizable functional groups. Further, when the ultraviolet-reactive functional group is a radically polymerizable functional group, a radical photopolymerization initiator can be used as the photopolymerization initiator. The radical photopolymerization initiator generates free radicals upon irradiation with ultraviolet rays or electron beams, and causes a radical polymerization reaction to cure the composition of the present invention. When curing the composition of the present invention by electron beam irradiation, a polymerization initiator is usually unnecessary.

(1) photocationic polymerization initiator

The photocationic polymerization initiator used in the curable composition of the present invention may be arbitrarily selected and used from those known in the art, and is not particularly limited to a specific one. As the photocationic polymerization initiator, strong acid generating compounds such as diazonium salts, sulfonium salts, iodonium salts, and phosphonium salts are known, and these can be used. Examples of photocationic polymerization initiators include bis(4-tert-butylphenyl)iodonium hexafluorophosphate, cyclopropyldiphenylsulfonium tetrafluoroborate, dimethylphenacylsulfonium tetrafluoroborate, diphenyliodonium Hexafluorophosphate, diphenyliodonium hexafluoroarsenate, diphenyliodonium tetrafluoromethanesulfonate, 2-(3,4-dimethoxystyryl)-4,6-bis(trichloro) Methyl) -1,3,5-triazine, 2-[2-(furan-2-yl)vinyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 4-iso Propyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate, 2-[2-(5-methylfuran-2-yl)vinyl]-4,6-bis(trichloromethyl)- 1,3,5-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxystyryl)- 4,6-bis(trichloromethyl)-1,3,5-triazine, 4-nitrobenzenediazonium tetrafluoroborate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium bromide, tri-p- Tolylsulfonium hexafluorophosphate, tri-p-tolylsulfonium trifluoromethanesulfonate, diphenyliodonium triflate, triphenylsulfonium triflate, diphenyliodonium nitrate, bis(4-tert -Butylphenyl)iodonium perfluoro-1-butanesulfonate, bis(4-tert-butylphenyl)iodonium triflate, triphenylsulfonium perfluoro-1-butanesulfonate, N-hydroxy Naphthalimide triflate, p-toluenesulfonate, diphenyliodonium p-toluenesulfonate, (4-tert-butylphenyl)diphenylsulfonium triflate, tris(4-tert-butylphenyl)sulfonium Triflate, N-hydroxy-5-norbornene-2,3-dicarboximide perfluoro-1-butanesulfonate, (4-phenylthiophenyl)diphenylsulfonium triflate and 4-(phenylthio ) Phenyldiphenylsulfonium triethyltrifluorophosphate and the like, but are not limited thereto. As a photocationic polymerization initiator, in addition to the above compounds, Omnicat 250, Omnicat 270 (above, IGM Resins B.V.), CPI-310B, IK-1 (above, San-Apro Ltd.), DTS- Commercially available photoinitiators such as 200 (Midori Kagaku Co., Ltd.) and Irgacure 290 (BASF Corporation) are exemplified.

The amount of photocationic polymerization initiator added to the curable composition of the present invention is not particularly limited as long as the desired photocuring reaction occurs, but is generally 0.1 to 10% by mass relative to the total amount of component (A) of the present invention, preferably. It is preferable to use a photocationic polymerization initiator in an amount of 0.2 to 5% by mass, particularly 0.5 to 4% by mass.

When the UV-reactive functional group of component (A) is a photocationic polymerization initiator such as an epoxy group, a photoradical polymerization initiator described below may be used as the polymerization initiator in addition to the photocationic polymerization initiator described above. By using both initiators together, the curability of the ultraviolet curable organopolysiloxane composition may be improved.

(2) Photoradical polymerization initiator

Radical photopolymerization initiators are broadly divided into photocleavage type and dehydrogenation type. The photoradical polymerization initiator used in the composition of the present invention can be arbitrarily selected and used from those known in the art, and is limited to a particularly specific one. It doesn't work. Examples of photoradical polymerization initiators include acetophenone, p-anisyl, benzyl, benzoin, benzophenone, 2-benzoyl benzoic acid, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(dimethyl amino) benzophenone, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin ethyl ether, 4-benzoyl benzoic acid, 2,2'-bis(2-chlorophenyl)-4,4', 5,5'-tetraphenyl-1,2'-biimidazole, methyl 2-benzoyl benzoate, 2-(1,3-benzodioxol-5-yl)-4,6-bis(trichloromethyl) -1,3,5-triazine, 2-benzyl-2-(dimethylamino)-4'-morpholino butyrophenone, (±)-camphor-quinone, 2-chlorothioxanthone, 4,4' -Dichlorobenzophenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,4-diethylthioxanthen-9-one, diphenyl (2,4,6- Trimethylbenzoyl)phosphine oxide, ethyl(2,4,6-trimethylbenzoyl)phenyl phosphinate, 1,4-dibenzoyl benzene, 2-ethylanthraquinone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy -2-methylpropiophenone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, 2-isopropylthioxanthone, lithium phenyl (2,4,6-trimethyl Benzoyl) phosphinate, 2-methyl-4'-(methylthio)-2-morpholinopropiophenone, 2-isonitrosopropiophenone, 2-phenyl-2-(p-toluenesulfonyloxy) acetophenone and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; and the like, but are not limited thereto. In addition, as photo-radical polymerization initiators, in addition to the above compounds, Omnirad 651, 184, 1173, 2959, 127, 907, 369, 369E and 379EG (alkylphenone-based photopolymerization initiators, manufactured by IGM Resins B.V.), Omnirad TPO H, TPO-L and 819 (acylphosphine oxide photopolymerization initiator, IGM RESINS B.V.), Omnirad MBF and 754 (intra-molecular hydrogen removal type photopolymerization initiator, IGM Resins B.V.), Irgacure OXE01 and OXE02 (oxime ester photopolymerization initiator, BASF), etc. of initiators.

The amount of photoradical polymerization initiator added to the composition of the present invention is not particularly limited as long as the desired photopolymerization reaction or photocuring reaction occurs, but is generally 0.01 to 5% by mass, preferably 0.01 to 5% by mass, based on the total mass of the composition of the present invention. is used in an amount of 0.05 to 1% by mass.

In addition, a photosensitizer may be used in combination with the photocationic polymerization initiator or photoradical polymerization initiator. The use of a sensitizer can increase the photon efficiency of the polymerization reaction, and since a longer wavelength light can be used for the polymerization reaction than when only a photoinitiator is used, when the coating thickness of the composition is relatively thick, or a relatively long wavelength LED light source It is known that it is particularly effective when using Examples of the sensitizer include anthracene-based compounds, phenothiazine-based compounds, perylene-based compounds, cyanine-based compounds, merocyanine-based compounds, coumarin-based compounds, benzylidene ketone-based compounds, (thio)xanthene or (thio)xantone-based compounds, For example, isopropylthioxanthone, 2,4-diethylthioxanthone, squarylium-based compounds, (thia) pyrylium-based compounds, porphyrin-based compounds, etc. are known, but are not limited thereto, and any photosensitizer can be used in the curable composition of the present invention.

The cured product obtained from the curable composition of the present invention is the molecular chain length of component (A) or component (A1) and/or component (A2), the number of UV-reactive functional groups per molecule, the position of the UV-reactive functional group in the molecule, and the molecular Depending on the structure, it is possible to design so that the desired physical properties of the cured product and the curing speed of the curable composition are obtained, and the viscosity of the curable composition becomes a desired value. In addition, a cured product obtained by curing the curable composition of the present invention is also included in the scope of the present invention. In addition, the shape of the cured product obtained from the composition of the present invention is not particularly limited, and may be a thin coating layer or a sheet-shaped molded product. , it can also be used as a sealing material, an intermediate layer, such as a laminated body or a display device. The cured product obtained from the composition of the present invention is particularly preferably in the form of a thin film coating layer, and particularly preferably an insulating coating layer.

The curable composition of the present invention is suitable for use as a coating or potting agent, particularly as an insulating coating or potting agent for electronic devices and electrical devices.

The curable composition of the present invention preferably has a viscosity of 80 mPa·s or less, preferably 30 mPa·s or less, and even more preferably 20 mPa·s or less, as measured at 25° C. using a type E viscometer.

A cured product obtained by curing the curable composition of the present invention has a characteristic of having a refractive index of 1.45 or less measured at 25°C and a wavelength of 589 nm.

If desired, the cured product obtained by curing the curable composition of the present invention can be designed to have a dielectric constant of less than 3.0, less than 2.8, etc., and the curable composition of the present invention can also be used to form a coating layer having a low dielectric constant. Available.

When the curable composition of the present invention is used as a coating agent, in order to have fluidity and workability suitable for applying the composition to a substrate, the viscosity of the entire composition is measured using an E-type viscometer, preferably at 25 ° C. is 80 mPa·s or less, more preferably 1 to 60 mPa·s, still more preferably 5 to 30 mPa·s, and particularly preferably 5 to 20 mPa·s. In order to adjust the viscosity of the entire curable composition to a desired viscosity, a compound having a desired viscosity can be used as each component so that the viscosity of the entire composition has a desired viscosity.

In order to adjust the viscosity of the curable composition, improve the coating properties, and adjust the physical properties of the cured product, the above-described component (B), a compound having one or more ultraviolet reactive functional groups in one molecule and not containing a silicon atom, is added to the composition. It may be added, or the addition amount may be adjusted. The content of component (B) in the curable composition of the present invention is preferably an amount such that the mass ratio of component (B) to the total of components (A) and (B) is less than 50% in order to suppress an increase in refractive index. do. The mass proportion of component (B) to the sum of components (A) and (B) is preferably less than 20%, more preferably less than 10%, even more preferably less than 5%.

[Component (C)]

When the ultraviolet curable organopolysiloxane composition of the present invention is applied as a coating agent to the surface of a substrate by any method, in order to improve the wettability of the composition to the substrate and form a defect-free coating film, comprising the above-mentioned components Component (C) selected from the following may be further added to the composition of the present invention. It is particularly preferred to use an inkjet printing method as a method for coating the composition of the present invention on a substrate. Therefore, component (C) is a component that improves the wettability of the ultraviolet curable organopolysiloxane composition of the present invention to a substrate, and in particular, remarkably improves inkjet printing properties. Component (C) is at least one compound selected from the group consisting of (C1), (C2) and (C3) below.

(i) Component (C1)

Component (C1) is a non-acrylic nonionic surfactant that does not contain a silicon atom, that is, a non-acrylic nonionic surfactant. The non-acrylic type means that the surfactant does not have a (meth)acrylate group in its molecule. As surfactants usable as component (C1), organic nonionic surfactants such as glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, alkyl glycosides, acetylene glycol polyethers, and fluorine-based nonionic surfactants, etc., and these may be used alone or in combination of two or more. Specific examples of component (C1) include Kao Corporation Emulgen series, RHEODOL series, Evonik Industries product Surfynol (as an organic nonionic surfactant) SURFYNOL) 400 series, Nissin Chemical Industry Co., Ltd.'s OLFINE E series, and as fluorine-based nonionic surfactants, 3M's FC-4400 series, DIC Corporation's Gaisha's MEGAFACE 550 and 560 series.

Among these, Surfynol 400 series and Olfin E series, which are alkynol polyethers, are particularly preferred.

(ii) Component (C2) is a nonionic surfactant containing a silicon atom and having an HLB value of 4 or less. Here, the HLB value is a value indicating the degree of affinity of the surfactant for water and organic compounds, and here, as the HLB value, a value defined by the Griffin method (20 × total formula of hydrophilic parts/molecular weight) is used. Silicon polyether having polyether as a hydrophilic part, glycerol silicone having a (di)glycerol derivative as a hydrophilic part, carbinol silicone having a hydroxyethoxy group as a hydrophilic part, etc. are known as silicon-containing nonionic surfactants. Among these surfactants, those having an HLB value of 4 or less, that is, those having a mass fraction of the hydrophilic portion of 20% by mass or less are preferably used in the composition of the present invention. Among these, carbinol silicone is especially preferable.

(iii) Component (C3) is a silicone oil having a viscosity of 90 mPa·s or less at 25°C. Examples of the silicone oil include trimethylsilyl-polydimethylsiloxane at both ends, dimethylvinylsilyl-polydimethylsiloxane at both ends, trimethylsilyl-dimethylsiloxy/methylvinylsiloxy copolymer at both ends, and dimethylvinylsilyl-dimethylsiloxy/methyl at both ends. Vinylsiloxy copolymer, both ends trimethylsilyl-dimethylsiloxy/methylphenylsiloxy copolymer, both ends trimethylsilyl-dimethylsiloxy/diphenylsiloxy copolymer, both ends dimethylvinylsilyl-dimethylsiloxy/methylphenylsiloxy copolymers, dimethylvinylsilyl-dimethylsiloxy/diphenylsiloxy copolymers at both ends, and the like, but trimethylsilyl-polydimethylsiloxane at both ends and dimethylvinylsilyl-polydimethylsiloxane at both ends can be preferably used. A preferred viscosity range of the silicone oil is 2 to 50 mPa·s, a more preferred range is 2 to 30 mPa·s, and a further preferred viscosity range is 5 to 20 mPa·s. In addition, the value of the viscosity here is the value measured at 25 degreeC using the rotational viscometer described in the Example.

As for the components (C1) to (C3) described above, one or a combination of two or more of these can be used. The amount of component (C) in the curable composition is not particularly limited. It is preferable that the sum of (C3) (these are collectively referred to as component (C)) is 0.05% by mass or more and 1% by mass or less. If the amount of component (C) is less than 0.05% by mass with respect to 100% by mass of the total amount of components (A) and (B), the effect of improving the wettability of the curable composition to the substrate may not be sufficiently obtained. This is because if the amount of (C) exceeds 1% by mass with respect to 100% by mass of the total amount of components (A) and (B), component (C) may bleed out from the cured product after curing.

As component (C), it is preferable to use the silicone oil of component (C3) alone or in combination with one or more components selected from the group consisting of component (C1) and component (C2). It is particularly preferable to use component (C3) alone as (C).

<Other additives>

In addition to the above components, additional additives may be added to the composition of the present invention as desired. As an additive, although the thing enumerated below can be illustrated, it is not limited to these.

[adhesive imparting agent]

An adhesion promoter may be added to the composition of the present invention in order to improve adhesion or adhesion to a substrate in contact with the composition. When the curable composition of the present invention is used for applications requiring adhesiveness or adhesion to substrates such as coating agents and sealing materials, it is preferable to add an adhesiveness imparting agent to the curable composition of the present invention. As this adhesion promoter, any known adhesion promoter can be used as long as it does not inhibit the curing reaction of the composition of the present invention.

As examples of the adhesion promoter usable in the present invention, a trialkoxysiloxy group (e.g., trimethoxysiloxy group, triethoxysiloxy group) or a trialkoxysilylalkyl group (e.g., trimethoxysilylethyl group, trimethoxysilylethyl group) ethoxysilylethyl group) and an organosilane having a hydrosilyl group or an alkenyl group (eg, vinyl group, allyl group), or a linear structure, branched structure or cyclic structure having about 4 to 20 silicon atoms. nosiloxane oligomers; An organosilane having a trialkoxysiloxy group or a trialkoxysilylalkyl group and a methacryloxyalkyl group (eg, 3-methacryloxypropyl group), or a linear structure of about 4 to 20 silicon atoms, a branched structure, or cyclic organosiloxane oligomers; A trialkoxysiloxy group or a trialkoxysilylalkyl group and an epoxy group bonded alkyl group (eg, 3-glycidoxypropyl group, 4-glycidoxybutyl group, 2-(3,4-epoxycyclohexyl)ethyl group, 3-( organosilanes having a 3,4-epoxycyclohexyl)propyl group) or organosiloxane oligomers having a linear structure, a branched structure, or a cyclic structure having about 4 to 20 silicon atoms; organic compounds having two or more trialkoxysilyl groups (eg, trimethoxysilyl group, triethoxysilyl group); reactants of aminoalkyltrialkoxysilanes and epoxy group-bonded alkyltrialkoxysilanes, and ethylpolysilicates containing an epoxy group; specifically, vinyltrimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, and hydrogentrier Toxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethyne Toxysilane, 3-methacryloxypropyltriethoxysilane, 1,6-bis(trimethoxysilyl)hexane, 1,6-bis(triethoxysilyl)hexane, 1,3-bis[2-(tri) methoxysilyl)ethyl]-1,1,3,3-tetramethyldisiloxane, a reaction product of 3-glycidoxypropyltriethoxysilane and 3-aminopropyltriethoxysilane, silanol-capped methylvinylsiloxane oligomer and Condensation product of 3-glycidoxypropyltrimethoxysilane, condensation product of silanol-capped methylvinylsiloxane oligomer and 3-methacryloxypropyltriethoxysilane, tris(3-trimethoxysilylpropyl)isocyanurate can be heard

The amount of the adhesion promoter added to the curable composition of the present invention is not particularly limited, but since it does not promote the curing properties of the curable composition or discoloration of the cured product, it is 0.01 to 5 with respect to 100 parts by mass of components (A) and (B) in total. It is preferably within the range of parts by mass or within the range of 0.01 to 2 parts by mass.

[Other additives]

In the composition of the present invention, other additives may be added as desired in addition to or instead of the adhesion imparting agent described above. As additives that can be used, a leveling agent, a silane coupling agent not included in the above-mentioned adhesion imparting agent, an ultraviolet absorber, an antioxidant, a polymerization inhibitor, a filler (functionality such as a reinforcing filler, an insulating filler, and a thermally conductive filler) filler) and the like. If desired, appropriate additives may be added to the composition of the present invention. In addition, a thixotropy imparting agent may be added to the composition of the present invention, if necessary, particularly when used as a potting agent or sealing material.

[Refractive index of the cured product of the composition of the present invention]

A cured product obtained from the ultraviolet curable organopolysiloxane composition of the present invention may have a low refractive index, the refractive index of which is 1.45 or less as measured at 25°C and a wavelength of 589 nm.

[Usage]

The ultraviolet curable organopolysiloxane composition of the present invention can be cured not only by ultraviolet rays but also by using an electron beam, which is also one aspect of the present invention.

The curable composition of the present invention has low viscosity and is particularly useful as a material for forming insulating layers constituting various articles, particularly electronic devices and electrical devices. The composition of the present invention can be applied on a substrate, or sandwiched by two substrates, at least one of which is made of a material that transmits ultraviolet rays or electron beams, and the composition is cured by irradiating the composition with ultraviolet rays or electron beams to form an insulating layer. . In that case, pattern formation may be performed when the composition of the present invention is applied to a substrate, and then the composition may be cured, or when the composition is applied to a substrate and cured, the cured portion and the uncured portion by irradiation of ultraviolet rays or electron beams It is also possible to form an insulating layer of a desired pattern by leaving a portion and then removing the uncured portion with a solvent. In particular, when the cured layer according to the present invention is an insulating layer, it can be designed to have a low dielectric constant of less than 3.0.

Since the curable composition of the present invention has good transparency of a cured product obtained therefrom, it is particularly suitable as a material for forming an insulating layer of display devices such as touch panels and displays. In this case, the insulating layer may form a desired arbitrary pattern as described above, if necessary. Accordingly, display devices such as touch panels and displays including an insulating layer obtained by curing the ultraviolet curable organopolysiloxane composition of the present invention are also one aspect of the present invention.

In addition, by using the curable composition of the present invention, an article can be coated and then cured to form an insulating coating layer (insulating film). Therefore, the composition of the present invention can be used as an insulating coating agent. In addition, a cured product formed by curing the curable composition of the present invention can also be used as an insulating coating layer.

The insulating film formed from the curable composition of the present invention can be used for various purposes. In particular, it can be used as a constituent member of an electronic device or as a material used in a process of manufacturing an electronic device. Electronic devices include electronic devices such as semiconductor devices and magnetic recording heads. For example, the curable composition of the present invention can be used for semiconductor devices such as LSI, system LSI, DRAM, SDRAM, RDRAM, D-RDRAM, and multi-chip module insulating films of multilayer wiring boards, interlayer insulating films for semiconductors, etching stopper films, surfaces It can be used as a protective film, a buffer coating film, a passivation film for LSIs, a cover coating for a flexible copper clad board, a solder resist film, and a surface protective film for optical devices.

In addition to being used as a coating agent, the ultraviolet curable composition of the present invention is also suitable for use as a potting agent, particularly as an insulating potting agent for electronic devices and electrical devices.

The composition of the present invention can be used particularly as a material for forming a coating layer on the surface of a substrate using an inkjet printing method, and in that case, it is particularly preferable that the composition of the present invention contains the above-mentioned component (C).

The present invention will be further described below based on examples, but the present invention is not limited to the examples below.

Example

The ultraviolet curable composition and cured product thereof of the present invention are described in detail by examples. In addition, the measurement and evaluation in Examples and Comparative Examples were performed as follows.

[Viscosity of Curable Composition]

The viscosity (mPa·s) of the composition at 25°C was measured using a rotational viscometer (TOKIMEC INC. product, E-type viscometer VISCONIC EMD).

[Refractive index of curable composition and cured product thereof]

The refractive index (nD) of the cured product at 25°C was measured using a digital refractometer (RX-7000α manufactured by ATAGO CO., LTD.).

[Appearance of curable composition and cured product obtained therefrom]

Visually, the appearance of the curable composition and the cured product obtained therefrom was observed and evaluated.

[Preparation of Curable Composition]

Each material in the amount shown in Table 1 below was placed in a brown plastic material container and mixed well using a planetary mixer to prepare a curable composition.

[Curing of Curable Composition]

About 0.2 g of the curable composition was injected between two glass substrates with a spacer having a thickness of 0.18 mm therebetween. The composition was cured by irradiating LED light with a wavelength of 405 nm at an energy amount of 2 J/cm ² through one glass substrate from the outside, and a plate-shaped cured product having a side of 30 mm and a thickness of 0.18 mm was produced.

[Examples and Comparative Examples]

Using each of the following components, an ultraviolet curable composition having a composition (parts by mass) shown in Table 1 was prepared.

(A1a) 1,3-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3-tetramethyldisiloxane

(A1b) 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane

(A2) 1,1,1,3,5,5,5-heptamethyl-3-[2-(3,4-epoxycyclohexyl)ethyl]trisiloxane

(B1) 1,2-epoxydodecane

(B2) 1,7-octadiene diepoxide

(C) a catalyst masterbatch consisting of the following components

C: (C1)/(X)/(A2)=30/2.4/67.6 (mass ratio)

(C1): 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate

(X): 2-isopropylthioxanthone

ingredient Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 (A1a) 5.0 5.0 10.0 (A1b) 14.8 (A2) 81.9 91.7 91.7 (B1) 91.7 86.7 (B2) 5.0 (C) 3.3 3.3 3.3 3.3 3.3 Sum 100.0 100.0 100.0 100.0 99.9 Mass ratio of A2 [percentage]: 84.1 93.9 93.9 0 0 Mass ratio in the curable component of B [percentage]: (B1 + B2) / (A1a + A1b + A2 + B1 + B2) 0 0 5.1 92.7 87.6 Appearance of Curable Composition Transparency Transparency Transparency Transparency Transparency Cured product appearance Transparency Transparency Transparency not cured Transparency Viscosity of the composition 7 8 6 2 3 Refractive index of cured material 1.45 1.45 1.45 --- 1.47

As shown in Table 1, the ultraviolet curable compositions (Examples 1 to 3) of the present invention have a viscosity suitable for application to a substrate as a coating agent at 25° C. and have high transparency. Moreover, the refractive index of hardened|cured material is 1.45 or less. On the other hand, in the compositions containing no component (A2) (Comparative Examples 1 and 2), the cured product had a refractive index of 1.46 or more, or curing properties were insufficient.

The ultraviolet curable composition of the present invention is particularly suitable for the above-mentioned applications, particularly as a material for forming an insulating layer of display devices such as touch panels and displays.

Claims (20)

It contains at least one organosilicon compound (A) having at least one ultraviolet reactive functional group on average in one molecule, and the viscosity of the entire composition measured at 25°C using an E-type viscometer is 80 mPa·s or less, and An ultraviolet curable composition characterized in that the composition does not contain an organic solvent, and the cured product after curing has a refractive index of 1.45 or less as measured at 25°C and a wavelength of 589 nm. The ultraviolet curable composition according to claim 1, wherein the ultraviolet reactive functional group is a cationically polymerizable functional group. The ultraviolet curable composition according to claim 1 or 2, wherein the ultraviolet reactive functional group is an epoxy group-containing group. The ultraviolet curable composition according to any one of claims 1 to 3, wherein the proportion of component (A) in the curable composition is 80% by mass or more. The method according to any one of claims 1 to 4, wherein component (A) is (A1) at least one organosilicon compound having an average of two or more UV-reactive functional groups in one molecule and (A2) one in one molecule. An ultraviolet curable composition comprising at least one organosilicon compound selected from the group consisting of at least one organosilicon compound having an ultraviolet reactive functional group in a mass ratio of 100/0 to 0/100 (A1/A2). 6. The method of claim 5, wherein component (A2) has an average composition formula:
R _c R' _d SiO _(4-cd)/2 (2)
(Wherein, R is an ultraviolet reactive functional group,
R' is a group selected from monovalent hydrocarbon groups, hydroxyl groups, and alkoxy groups, excluding ultraviolet-reactive functional groups;
c and d are numbers satisfying the following conditions: 1<c+d≤4 and 0.05≤c/(c+d)≤0.25, and the number of R in the molecule is 1.)
An organosilicon compound selected from the group consisting of linear, branched or cyclic organosilanes and organopolysiloxanes represented by an ultraviolet curable composition. The ultraviolet curable composition according to claim 5 or 6, wherein the proportion of component (A2) in the composition is 80% by mass or more. 8. The method according to any one of claims 5 to 7, wherein component (A1) has an average composition formula:
R _a R' _b SiO _(4-ab)/2 (1)
(Wherein, R is an ultraviolet reactive functional group,
R' is a group selected from monovalent hydrocarbon groups, hydroxyl groups, and alkoxy groups, excluding ultraviolet-reactive functional groups;
a and b are numbers satisfying the following conditions: 1≤a+b≤3 and 0.01≤a/(a+b)≤0.34, and have at least two R's in the molecule.)
A UV curable composition which is a linear, branched or cyclic organopolysiloxane represented by 9. The organosilicon compound of any one of claims 5 to 8, wherein the organosilicon compound of component (A2) is of the formula (3'):
[Tue 1]

(Wherein, among all R ¹ to R ⁸ groups, only one UV-reactive functional group exists in the molecule; in addition, R ¹ to R ⁸ are each independently an unsubstituted or fluorine-substituted monovalent hydrocarbon group; n is It is a numerical value of 0 or more and 3 or less) organopolysiloxane represented by;
Or, the following formula (4'):
[Tue 2]

(Wherein, each R is independently a group selected from a UV-reactive functional group and an unsubstituted or fluorine-substituted monovalent hydrocarbon group, x is an integer of 3 to 5, and has only one UV-reactive functional group in the molecule) A cyclic organopolysiloxane represented by
Or, the following formula (5'):
RSiR' ₃ (5')
(Wherein, R is a UV-reactive functional group, R' is a group selected from a monovalent hydrocarbon group, a hydroxyl group and an alkoxy group excluding the above-mentioned UV-reactive functional group) An ultraviolet curable composition that is a silicon-containing compound having one functional group in a molecule. 10. The method according to any one of claims 5 to 9, wherein the organosilicon compound of component (A1) is of the formula (3):
[Tue 3]

(Wherein, among all R ¹ to R ⁸ groups, an average of 2 or more per molecule is an ultraviolet reactive functional group; other R ¹ to R ⁸ are each independently an unsubstituted or fluorine-substituted monovalent hydrocarbon group; n is a numerical value at which the viscosity of the organopolysiloxane represented by formula (3) is 1 to 1000 mPa s at 25 ° C, and n may be 0) organopolysiloxane represented by;
Mean unit formula:
(R ₃ SiO _1/2 ) _e (R ₂ SiO _2/2 ) _f (RSiO _3/2 ) _g (SiO _4/2 ) _h (4)
(Wherein, each R is independently a group selected from a UV-reactive functional group and an unsubstituted or fluorine-substituted monovalent hydrocarbon group, and among all R, at least two are UV-reactive functional groups, and (g + h) is an amount is a number, e is 0 or a positive number, and f is a number in the range of 0 to 10.)
An organopolysiloxane represented by
Equation (5):
[Tuesday 4]

(Wherein, each R is independently a group selected from a UV-reactive functional group and an unsubstituted or fluorine-substituted monovalent hydrocarbon group, x is an integer of 3 to 10, and has at least two UV-reactive functional groups in the molecule) A cyclic organopolysiloxane represented by
and at least one organopolysiloxane having an ultraviolet-reactive functional group selected from the group consisting of mixtures of two or more organopolysiloxanes arbitrarily selected therefrom. The ultraviolet curable composition according to any one of claims 5 to 10, wherein the number of ultraviolet reactive functional groups of component (A1) is two on average per molecule. The ultraviolet curable composition according to any one of claims 5 to 11, wherein the component (A2) is an organopolysiloxane having one ultraviolet reactive functional group in its molecule. The ultraviolet curable composition according to any one of claims 1 to 12, wherein the viscosity of the entire composition measured at 25°C using an E-type viscometer is in the range of 5 to 30 mPa·s. 14. The method according to any one of claims 5 to 13, wherein component (A) is (A2) 1,1,1,3,5,5,5-heptamethyl-3-[2-(3,4-epoxy cyclohexyl)ethyl]trisiloxane, or (A2) 1,1,1,3,5,5,5-heptamethyl-3-[2-(3,4-epoxycyclohexyl)ethyl]trisiloxane; An ultraviolet curable composition which is a mixture of at least one compound selected from the following (A1), the mass ratio of which is in the range of 100/0 to 20/80 (A2/A1):
(A1):
1,3-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3-tetramethyldisiloxane, 1,5-bis[2-(3,4-epoxycyclohexyl) Ethyl]-1,1,3,3,5,5-hexamethyltrisiloxane, methyl(tris[2-(3,4-epoxycyclohexyl)ethyl]dimethylsiloxy)silane, tetrakis([2-( 3,4-epoxycyclohexyl)ethyl]dimethylsiloxy)silane, 1,3,5,7-tetramethyl-1,3,5,7-tetra[2-(3,4-epoxycyclohexyl)ethyl] -Cyclotetrasiloxane, 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane, 1,5-bis(3-glycidoxypropyl)-1,1, 3,3,5,5-hexamethyltrisiloxane, methyl[tris(3-glycidoxypropyl)dimethylsiloxy]silane, tetrakis[(3-glycidoxypropyl)dimethylsiloxy]silane, 1,3 ,5,7-tetramethyl-1,3,5,7-tetra(3-glycidoxypropyl)-cyclotetrasiloxane. 15. The method according to any one of claims 5 to 14, wherein as component (A) (A2) 1,1,1,3,5,5,5-heptamethyl-3-[2-(3,4-epoxy) A UV curable composition comprising cyclohexyl) ethyl] trisiloxane within the range of 50 to 95% by mass of the total composition. The compound according to any one of claims 5 to 15, further comprising (B) a compound having at least one ultraviolet-reactive functional group in one molecule and not having a silicon atom, component (A1), component (A2) ) and the mass ratio of component (B) to the sum of component (B) is less than 20%. The ultraviolet curable composition according to claim 16, comprising only component (A2) as component (A) or a combination of component (A1) and component (A2) as component (A). An insulating coating agent comprising the ultraviolet curable composition according to any one of claims 1 to 17. A method of using a cured product of the ultraviolet curable composition according to any one of claims 1 to 17 as an insulating coating layer. A display device comprising a layer made of a cured product of the ultraviolet curable composition according to any one of claims 1 to 17.