UV-activated silicone composition and method for manufacturing adhesive members using the same

Abstract

To provide a method for manufacturing adhesive members that have high adhesive properties and are highly reliable as components. [Solution] A method for manufacturing an adhesive member is provided, comprising the steps of applying an ultraviolet-curable silicone composition containing (A) an organopolysiloxane containing an unsaturated group, (B) an organohydrogenpolysiloxane, and (C) an ultraviolet-activated hydrosilylated platinum catalyst having a cyclopentadienyl group to which a condensed aromatic hydrocarbon group is bonded as a ligand, to a first substrate layer, and (i) bonding the first substrate layer to which the ultraviolet-curable silicone composition has been applied to a second substrate layer via a layer of ultraviolet-curable silicone composition; (ii) depressurizing the ultraviolet-curable silicone composition applied to the first substrate layer under a pressure below atmospheric pressure; and (iii) irradiating the ultraviolet-curable silicone composition applied to the first substrate layer with ultraviolet light; in any order.

Description

[Technical Field]

[0001] The present invention relates to an ultraviolet-activated silicone composition as an adhesive and a method for manufacturing an adhesive member using the same. [Background technology]

[0002] In recent years, flat-panel image display devices such as liquid crystal displays, plasma displays, and organic EL displays have attracted attention. Flat-panel image display devices typically have a display area (image display section) in which a large number of pixels, consisting of semiconductor layers, phosphor layers, or light-emitting layers constituting active elements, are arranged in a matrix between a pair of substrates, at least one of which is light-transmitting, such as glass. Generally, the area around this display area (image display section) and a protective section formed from optical plastics such as glass or acrylic resin is tightly sealed with an adhesive. As the adhesive used here, ultraviolet-curable resin compositions such as ultraviolet-curable acrylic resins and ultraviolet-curable silicone resin compositions are used (Patent Document 1).

[0003] UV-curable silicone resin compositions can utilize a hydrosilylation reaction with a platinum catalyst, and although a means to sufficiently cure areas not reached by UV light may be necessary, they are used as compositions that can be cured under relatively mild conditions (Patent Documents 2-5). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2008-282000 [Patent Document 2] International Public Gazette No. 2023 / 112925 [Patent Document 3] Special Publication No. 2023-514372 [Patent Document 4] Japanese Patent Publication No. 2020-158548 [Patent Document 5] Japanese Patent Publication No. 2001-89491 [Overview of the project] [Problems that the invention aims to solve]

[0005] UV-curable silicone compositions can be efficiently and uniformly cured at room temperature and are used in optical bonding and as encapsulants for LEDs. In bonding components, a process of placing the bonded material under reduced pressure is sometimes included to remove air bubbles and highly volatile substances such as solvents that may be present in the adhesive, thereby achieving uniform and good adhesive strength. However, the inventors have found that conventional UV-curable silicone compositions, such as those used in the above-mentioned patent documents, may experience a decrease in curability when placed under reduced pressure. In particular, with the recent trend towards thinner image display devices, the thickness of the adhesive layer also needs to be reduced, and the decrease in curability when the adhesive layer is thin and subjected to reduced pressure treatment was significant. The curability of UV-curable silicone compositions is a property that can affect adhesiveness, and there is a demand for compositions that improve in this respect.

[0006] The present invention aims to improve upon the above-mentioned problems and provide an adhesive made of a silicone composition with excellent curability, as well as an adhesive member with high adhesiveness and high reliability as a component, and a method for manufacturing the same. [Means for solving the problem]

[0007] The inventors have found that conventional UV-curable silicone compositions may lose some of their platinum catalyst when placed under a reduced-pressure atmosphere. To solve this problem, they have found a more suitable catalyst design. Specifically, they have found that a platinum complex having a cyclopentadienyl group with a fused cyclic aromatic hydrocarbon substituent as a ligand is effective as a catalyst. [Effects of the Invention]

[0008] The present invention provides an adhesive made of a silicone composition with excellent curability, an adhesive member with high adhesiveness and reliability as a component, and a method for manufacturing the same. In other words, the present invention relates to the inventions described in the following sections. [1] A method for manufacturing an adhesive member, (A) Organopolysiloxanes containing at least two unsaturated groups bonded to silicon atoms in one molecule, (B) An organohydrogenpolysiloxane having at least three hydrogen atoms bonded to a silicon atom in one molecule, and (C) UV-activated hydrosilylated platinum catalyst having a cyclopentadienyl group bonded to a condensed aromatic hydrocarbon group as a ligand, The process includes the step of applying an ultraviolet-curable silicone composition containing to a first substrate layer, (i) A step of bonding a first substrate layer to which an ultraviolet-curable silicone composition has been applied to a second substrate layer via a layer of ultraviolet-curable silicone composition; (ii) A step of depressurizing the ultraviolet-curable silicone composition applied to the first substrate layer under a pressure below atmospheric pressure; and (iii) A step of irradiating the UV-curable silicone composition applied to the first substrate layer with ultraviolet light; A method that includes the following in any order. [2] The method according to [1], wherein steps (i), (ii), and (iii) are performed in the order of step (ii), step (iii), and step (i). [3] The method according to [1], wherein steps (i), (ii), and (iii) are performed in the order of step (iii), step (ii), and step (i). [4] The method according to any one of [1] to [3], wherein step (iii) is a step of irradiating with ultraviolet light having a wavelength of 365 nm or more. [5] The method according to any one of [1] to [4], wherein the component (A) is a linear organopolysiloxane. [6] The method according to any one of [1] to [5] above, wherein the unsaturated group of the organopolysiloxane in (A) is an alkenyl group. [7] The method according to any one of [1] to [6], wherein the ratio of the amount of substance (H / Vi ratio) of hydrogen directly bonded to silicon in (B) to the unsaturated group in (A) is in the range of 0.2 to 2.0. [8] The method according to any one of [1] to [7], wherein the UV-activated hydrosilylated platinum catalyst of (C) is [1-methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatinum or [1-methyl-3-(9'-phenanthryl)-cyclopentadienyl]trimethylplatinum. [9] The method according to any one of [1] to [8], wherein the first or second substrate is selected from the group consisting of epoxy resin, polyester resin, polycarbonate resin, acrylic resin, polarizing plate, and glass.

[10] (A)Organopolysiloxanes containing at least two unsaturated groups bonded to silicon atoms in one molecule, (B) Organohydrogenpolysiloxane having at least 3 hydrogen atoms bonded to a silicon atom in one molecule, (C) UV-activated hydrosilylated platinum catalyst having a cyclopentadienyl group bonded to a condensed aromatic hydrocarbon group as a ligand, A UV-curable silicone composition for bonding substrates, containing [the specified ingredient].

[11] The UV-curable silicone composition according to

[10] , wherein the UV-activated hydrosilylated platinum catalyst of (C) is [1-methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatinum or [1-methyl-3-(9'-phenanthryl)-cyclopentadienyl]trimethylplatinum.

[12] A member having a layer bonded with the ultraviolet-curable silicone composition described in

[10] or

[11] above.

[13] (A)Organopolysiloxanes containing at least two unsaturated groups bonded to silicon atoms in one molecule, (B) Organohydrogenpolysiloxane having at least 3 hydrogen atoms bonded to a silicon atom in one molecule, (C) UV-activated hydrosilylated platinum catalyst having a cyclopentadienyl group bonded to a condensed aromatic hydrocarbon group as a ligand, An ultraviolet-curable silicone composition containing an organic solvent that is liquid at room temperature and pressure and volatilizes under reduced pressure, with the content of the organic solvent being 0% by mass relative to the entire composition. [Modes for carrying out the invention]

[0009] The present invention will be described in detail below, item by item, including the composition for bonding substrates and the bonding method. In this specification, the "~" indicating a numerical range is used to mean that the numbers written before and after it are included as the lower limit and upper limit.

[0010] As used herein, "organic group" means a group containing carbon. The valency of an organic group is indicated by "n-valenced," where n is any natural number. Therefore, for example, a "monovalent organic group" means a group containing carbon that has only one bond. The bond may be held by an element other than carbon. Even if the valency is not specifically stated, a person skilled in the art can determine the appropriate valency from the context.

[0011] As used herein, "hydrocarbon group" means a group containing carbon and hydrogen, from which at least one hydrogen atom has been removed from the molecule. Such hydrocarbon groups are not particularly limited, but include hydrocarbon groups having 1 to 20 carbon atoms, which may be substituted with one or more substituents, such as aliphatic hydrocarbon groups and aromatic hydrocarbon groups. The above-mentioned "aliphatic hydrocarbon group" may be linear, branched, or cyclic, and may be saturated or unsaturated. Furthermore, the hydrocarbon group may contain one or more ring structures. In addition, such hydrocarbon groups may have one or more heteroatoms or structures containing heteroatoms, such as nitrogen (N), oxygen (O), sulfur (S), silicon (Si), amide bonds, sulfonyl bonds, siloxane bonds, carbonyl groups, and carbonyloxy groups, at their terminals or in their molecular chains.

[0012] As used herein, the substituent of "hydrocarbon group" is not particularly limited. For example, a halogen atom; a C 1-6 alkyl group, a C 2-6 alkenyl group, a C 2-6 alkynyl group, a C 3-10 cycloalkyl group, a C 3-10 unsaturated cycloalkyl group, a 5- to 10-membered heterocyclyl group, a 5- to 10-membered unsaturated heterocyclyl group, a C 6-10 aryl group, and a group selected from 5- to 10-membered heteroaryl groups may be mentioned.

[0013] In this specification, unless otherwise specified, the alkyl group and the phenyl group may be unsubstituted or substituted. The substituent of such a group is not particularly limited. For example, a halogen atom, a C 1-6 [[ID=—18]]alkyl group, a C 2-6 alkenyl group, and a C 2-6 alkynyl group, one or more groups selected therefrom may be mentioned.

[0014] [UV-curable silicone composition] · Component (A) The UV-curable silicone composition of the present invention contains at least one organopolysiloxane containing an unsaturated group bonded to at least two silicon atoms in one molecule as component (A). Component (A) functions as a base polymer of the UV-curable silicone composition. The unsaturated group can be present at any position in the polyorganosiloxane molecule. For example, it may have an unsaturated group at the molecular terminal, or may be present as a side chain at a site other than the terminal. In the case of a linear polyorganosiloxane, the unsaturated group is preferably present at least one at each of both ends of the molecular main chain of component (A). Here, in this specification, the molecular main chain of component (A) represents the relatively longest bonding chain in the molecule of component (A).

[0015] The type of unsaturated group is not particularly limited as long as it is a functional group that undergoes an addition reaction with component (B), which will be described later, and an alkenyl group is a typical example. The unsaturated group of the organopolysiloxane of component (A) is preferably an alkenyl group. The type of alkenyl group is not particularly limited as long as it has a carbon-carbon double bond and is capable of an addition reaction. The number of carbon atoms in the alkenyl group is preferably 2 to 20, preferably 2 to 8, and more preferably 2 to 6. The alkenyl group may have a branched structure or a cyclic structure. The position of the carbon-carbon double bond in the hydrocarbon constituting the alkenyl group can be any position. From the viewpoint of reactivity, it is preferable that the carbon-carbon double bond is at the end of the group. A preferred example of an alkenyl group is the vinyl group, because it facilitates the synthesis of polyorganosiloxanes.

[0016] The molecular skeleton of component (A) is not particularly limited, as long as the siloxane bond is the main skeleton. The siloxane in the molecular skeleton may be linear, branched, cyclic, or a combination thereof, and may form a molecular skeleton with a three-dimensional extent. Component (A) is preferably a linear organopolysiloxane. The siloxane skeleton may also be interrupted by divalent organic groups. Hereinafter, when describing the structure of siloxane compounds in this specification, structural units of siloxane compounds may be described by the following abbreviations.Hereinafter, these structural units may be referred to as "M units," "D units," etc. M:-Si(CH3)3O 1 / 2 M H :-SiH(CH3)2O 1 / 2 M Vi :-Si(CH=CH2)(CH3)2O 1 / 2 D:Si(CH3)2O 2 / 2 D H :SiH(CH3)O 2 / 2 T:Si(CH3)O 3 / 2 Q:SiO4 / 2 In this specification, siloxane compounds are constructed by combining the above structural units, but may at least partially include those in which the methyl group of the above structural unit is replaced by another group, such as a halogen such as fluorine or a hydrocarbon group such as a phenyl group. In this case, to indicate that the unit is substituted with a substituent, the D unit substituted with a phenyl group is referred to as D. Ph It is sometimes written like this. Also, for example, D Ph 20 D 20 When written as such, the notation is intended to indicate that a total of 20 phenyl groups are contained within the 40 D units. Ph It is not intended that 20 units are followed by 20 D units. Each unit may be arranged arbitrarily, and SiPh2O 2 / 2 (D Ph2 It is understood that the compound may contain structural units represented as shown above. Siloxane compounds can take on various three-dimensional structures using T or Q units, but component (A) can take on a linear molecular skeleton formed by arbitrarily combining the above M and D units.

[0017] In one embodiment of the present invention, component (A) is not particularly limited as long as it has an average of two or more unsaturated groups, particularly alkenyl groups, bonded to silicon atoms in one molecule, and can form a network structure by addition reaction with the hydrosilyl group (Si-H group) of component (B), which will be described later. Component (A) is typically represented by general formula (1): (R 1 ) m (R 2 ) n SiO (4-m-n) / 2 (1) (In the formula, R 1 This is an unsubstituted or substituted monovalent hydrocarbon group that does not have an aliphatic unsaturated bond; R 2 is an unsaturated group, preferably an alkenyl group; m is an integer between 0 and 2; n is an integer between 1 and 3, where m+n is between 1 and 3. The molecule contains at least two unsaturated group-containing siloxane units, as shown by .

[0018] One specific example of component (A) is the following formula (2): (R a ) 3-p R p Si-O-(Si(R) r (R a ) 2-r O) n -SiR q (R a ) 3-q ...(2) (In the formula, R a Each of these is independently an unsaturated group, preferably an alkenyl group. Each R is independently a monovalent organic group. p and q are independently 0, 1, or 2. r is independently 0, 1, or 2. n is a number representing a viscosity between 0.1 and 500 Pa·s at 23°C. A linear polyorganosiloxane represented by is an example. R is preferably a hydrocarbon group, particularly an alkyl group, an alkenyl group, or an aryl group. From the viewpoint of controlling physical properties such as refractive index, at least a portion of R may be an aryl group such as a phenyl group. Polyorganosiloxanes in which all R are methyl are preferably used due to their availability, but from the viewpoint of adjusting the refractive index, 1 to 40 mol% of R may be C6 to C6. 12 It is preferable that the group be an aryl group, and from the viewpoint of viscosity and thixotropy, 1 to 20 mol% of R should be C6 to C6. 12 It is preferable that the group be an aryl group. Regarding the position of the unsaturated group (alkenyl group), a polyorganosiloxane in which r is 2 in formula (2) above is preferred, that is, a linear polyorganosiloxane in which at least one unsaturated group (alkenyl group) is present only at each end of the molecule.

[0019] As for polyorganosiloxanes having unsaturated groups, it is preferable that in formula (2) above, p and q are 2 and r is 2, that is, that there are a total of two unsaturated groups, one at each of the molecular ends, preferably alkenyl groups, and especially vinyl groups. Commercially available polyorganosiloxanes can be used as such component (a). Alternatively, polyorganosiloxanes to which curable functional groups have been introduced by known reactions may be used. Component (A) may be classified by the position or type of substituents, degree of polymerization, etc., and only one compound may be used, or two or more compounds may be mixed and used. Since component (A) is a polyorganosiloxane, it may be a mixture of polyorganosiloxanes having various degrees of polymerization.

[0020] The amount of component (A) is not particularly limited, as long as it is within a range of viscosity that the UV-curable silicone composition can handle. Based on the amount of component (A), the amounts of other components can be appropriately set within the preferred ranges shown individually below.

[0021] ·Component (B) The ultraviolet-curable silicone composition of the present invention includes a compound that has reactivity with the curable functional group of component (A) as a crosslinking agent (hereinafter sometimes simply referred to as "component (B)"). The inclusion of a crosslinking agent improves the physical properties of the cured product obtained from the curable composition, such as tensile strength and elastic modulus. As component (B), an organohydrogenpolysiloxane having at least three hydrogen atoms bonded to silicon atoms (Si-H bonds) in one molecule as crosslinking groups is used. An example of component (B) is an organohydrogenpolysiloxane obtained by any number and type combination of structural units shown in the following formula, wherein the total number of Si-H bonds is 3 or more. (H (3-a) R 1 a SiO 1 / 2 ) (M H unit) (R 1 3SiO 1 / 2 ) (HR1 SiO 2 / 2 ) (D H unit) (R 1 2SiO 2 / 2 ) (HSiO 3 / 2 ) (R 1 SiO 3 / 2 ) (SiO 4 / 2 ) (In each of the above formulas, R 1 Each of these independently represents an unsubstituted or substituted monovalent hydrocarbon group that does not have an aliphatic unsaturated bond, and a is either 1 or 2.

[0022] Examples of preferred component (B) include linear organohydrogenpolysiloxanes represented by the following formula (3), which have Si-H bonds in the parts of the molecular chain other than the ends. (R 1 3SiO 1 / 2 )2(HR 1 SiO 2 / 2 ) c (R 1 2SiO 2 / 2 ) d ...(3) (In the formula, R 1 (where a is as defined above, c is a number greater than or equal to 3, and d is a number greater than or equal to 0) Component (B) has three or more Si-H bonds per molecule, including at least one in the side chain, which allows it to form a network structure through a crosslinking reaction. Component (B) may be used alone or two or more simultaneously.

[0023] R 1 Each of these independently represents an unsubstituted or substituted monovalent hydrocarbon group that does not have an aliphatic unsaturated bond. 1 As such, hydrocarbon groups, for example alkyl or aryl groups, particularly methyl or phenyl groups are preferred. From the viewpoint of controlling physical properties such as refractive index, R 1 At least a portion of it may be an aryl group such as a phenyl group.

[0024] As another example of component (B), a linear organohydrogenpolysiloxane having a Si—H bond at the terminal and represented by the following formula (4) can be mentioned. (H (3-a) R 1 a SiO 1 / 2 ) b (R 1 3SiO 1 / 2 ) 2-b (HR 1 SiO 2 / 2 ) e (R 1 2SiO 2 / 2 ) d ···(4) (In the formula, R 1 , a, and d are as defined above, b is 0, 1, or 2, and e is a number of 1 or more)

[0025] The siloxane skeleton in the organohydrogenpolysiloxane preferably has a mainly linear skeleton. The main chain of such an organohydrogenpolysiloxane may have a branched structure as a substituent although it has a linear skeleton. Further, the number of hydrogen groups (that is, equivalent to Si—H bonds) bonded to silicon atoms contained in one molecule is 3 or more, more preferably 5 or more on average per molecule, and even more preferably 8 or more. Other conditions in the organohydrogenpolysiloxane, organic groups other than hydrogen groups, bonding positions, degree of polymerization, structure, etc. are not particularly limited. In the case of a linear organohydrogenpolysiloxane, when the value of c + d + 2 in the above formula (3) is expressed as the degree of polymerization, a degree of polymerization in the range of 5 to 200, particularly 10 to 120, is preferable because the handleability of the resulting composition tends to be more improved. Specific examples of the organohydrogenpolysiloxane that can be used are linear organohydrogenpolysiloxanes having a skeleton and containing 8 or more units (M H or D H units) having a Si—H bond and having a degree of polymerization in the range of 10 to 120.

[0026] The blending amount of component (B) can be designed to fall within an appropriate range while using the criteria described below, according to the amount of unsaturated groups in component (A). As component (B), depending on the position or type of the crosslinking group, the degree of polymerization of the organohydrogenpolysiloxane, etc., only one type of compound may be used, or two or more types of compounds may be mixed and used. Component (B) may be a mixture of organohydrogenpolysiloxanes having various degrees of polymerization.

[0027] Component (B) has H at both ends (3-a) R 1 a SiO 1 / 2 units or R 1 3SiO 1 / 2 units and is blocked, and the intermediate units have at least one HR 1 SiO 2 / 2 units and any number of R 1 2SiO 2 / 2 units, and is a linear organohydrogenpolysiloxane. The hydrogen atoms bonded to the silicon atoms are at least one in the intermediate units, and the remaining at least two may be present at the ends or in the intermediate units. As in the above formula (3), it is preferable that the hydrogen atoms bonded to the silicon atoms are present within the intermediate units.

[0028] H As component (B), (B1-1) a linear polymethylhydrogen siloxane in which both ends are blocked with M units (trimethylsiloxane units) and the intermediate units consist only of D H units (methylhydrogensiloxane units), (B1-2) a linear polymethylhydrogen siloxane in which both ends are blocked with M units (trimethylsiloxane units) and the intermediate units consist only of D units (dimethylsiloxane units) and D

[0029] units (methylhydrogensiloxane units), and the amount of methylhydrogensiloxane units is 0.1 to 3.0 moles per 1 mole of dimethylsiloxane units, is particularly preferable. Component (B) may be one type or a combination of two or more types.The amount of component (B) is preferably such that there are 0.2 to 2.0 hydrogen atoms directly bonded to silicon atoms for each curable functional group (alkenyl group) of component (A). If the amount is less than 0.2, curing may not proceed at a sufficient rate, and if it exceeds 2.0, the cured product may become too hard and may adversely affect the physical properties after curing. In other words, the amount of polyorganosiloxane having alkenyl groups (especially vinyl groups) in the molecule can be adjusted by the ratio of the amount of Si-H bonds to vinyl groups (H / Vi ratio) of the organohydrogenpolysiloxane. The H / Vi ratio is more preferably in the range of 0.2 to 2.0, and even more preferably in the range of 0.5 to 1.7. By setting the H / Vi ratio to 0.5 or higher, curing at a sufficient rate can be achieved, and better adhesion to various substrates can also be observed. Furthermore, by setting the H / Vi ratio to 2.0 or less, sufficient curing of the composition can be achieved, the hardness can be maintained at an appropriate level, heat resistance can be preserved, and better adhesion can be maintained.

[0030] ·Component (C) The composition of the present invention includes a curing catalyst capable of catalyzing the crosslinking reaction between component (A) and component (B) (hereinafter sometimes simply referred to as "component (C)"). As the curing catalyst, an ultraviolet-activated hydrosilylated platinum catalyst having a cyclopentadienyl group to which a condensed aromatic hydrocarbon group, preferably a naphthyl group, is bonded as a ligand is used. The amount of the catalyst added is such that it is 0.1 to 1000 ppm of platinum relative to component (A). If the amount is less than 0.1 ppm, it may not be possible to achieve sufficient catalytic efficiency for the composition to cure properly, and if it exceeds 1000 ppm, no particular improvement in curing speed can be expected.

[0031] A specific example of a curing catalyst is shown in the following formula. [(R x ) x (R y ) y H 4-x-y C5]Pt(R z )3 (In the formula, R x It is a condensed aromatic hydrocarbon group having 7 to 20 carbon atoms. R y These are condensed aromatic hydrocarbon groups having 7 to 20 carbon atoms or aliphatic hydrocarbon groups having 1 to 22 carbon atoms. R z Each of these is independently an aliphatic hydrocarbon group or a trialkylsilyl group having 1 to 22 carbon atoms. x is an integer from 1 to 3, When y is an integer from 0 to 3, and x+y is an integer from 1 to 4, and x or y is 2 or 3, each R x or R y (They may be the same or different from each other.) This is a platinum-cyclopentadienyl complex represented by [formula].

[0032] base R x As a condensed aromatic hydrocarbon group, it is acceptable to have a structure in which two or more aromatic rings are condensed, such as a naphthyl group (C 10 H7), phenanthryl group (C 14 H9), anthracenyl group (C 14 H9), pyrenyl group (C 16 Examples include H9), but it is preferably a naphthyl group or a phenanthryl group, and particularly preferably a naphthyl group. These groups may be further substituted with one or more substituents such as a methyl group, an isopropyl group, a tert-butyl group, or a phenyl group. Substituent R of the cyclopentadienyl group x The present invention is based on the discovery that by using a platinum complex having a condensed aromatic hydrocarbon group, particularly a naphthyl group, the platinum complex is not lost from the composition by sublimation or other means even under reduced pressure, and the curability of the UV-curable silicone composition is not impaired.

[0033] base R y , R z As the aliphatic hydrocarbon group having 1 to 22 carbon atoms, an alkyl group having 1 to 6 carbon atoms is preferred, and a methyl group is more preferred. base R zExamples include trialkylsilyl groups having three alkyl groups with 1 to 6 carbon atoms. The alkyl groups bonded to silicon may be of different types, but trimethylsilyl groups are preferred.

[0034] Platinum ligand [(R x ) x (R y ) y H 4-x-y C5] forms a substituted cyclopentadienyl group and is bonded to platinum by a σ bond. That is, one of the carbon atoms forming the 5-membered ring of the cyclopentadienyl group is bonded to platinum. Therefore, substituent R on the cyclopentadienyl group x and R y The total number is between 1 and 4. x and R y The substitution position, i.e., R x or R y There are no particular restrictions on which carbon atom is bonded to which carbon atom of the cyclopentadienyl group.

[0035] More specific examples of curing catalysts include [(1'-naphthyl)-cyclopentadienyl]trimethylplatinum; [(2'-naphthyl)-cyclopentadienyl]trimethylplatinum; [1-methyl-3-(1'-naphthyl)-cyclopentadienyl]trimethylplatinum; [1-methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatinum; [(9'-phenanthryl)-cyclopentadienyl]-trimethylplatinum; [ Examples of curing catalysts include [1-methyl-3-(9'-phenanthryl)-cyclopentadienyl]-trimethylplatinum; [1-(2'-anthracenyl)-3-methyl-cyclopentadienyl]-trimethylplatinum; [(2'-anthracenyl)-cyclopentadienyl]trimethylplatinum; [(1'-pyrenyl)-cyclopentadienyl]trimethylplatinum; and [1-methyl-3-(1'-pyrenyl)-cyclopentadienyl]trimethylplatinum. More preferred curing catalysts are [1-methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatinum or [1-methyl-3-(9'-phenanthryl)-cyclopentadienyl]trimethylplatinum. Other curing catalysts that can be represented by the above formula may be used, and two or more curing catalysts may be used in combination.

[0036] As the platinum complex, commercially available ones may be used, or those synthesized by known means may be used. For example, the desired platinum complex can be obtained by reacting a lithium salt of a substituted cyclopentadiene with a platinum(IV) complex having a leaving group such as a halogen or phosphate. Alternatively, for the purpose of handling and achieving uniformity in the composition, a solution in which the platinum complex is dissolved in a solvent such as aromatic hydrocarbons such as toluene, hydrocarbons such as heptane, ethers, ketones, or alcohols may be used. However, in order to suppress the amount of volatile components in the composition, it is preferable to use a small amount of solvent, and it is more preferable to use the platinum complex as a solid rather than in solution.

[0037] Depending on the application of the UV-curable silicone composition, the activity of the catalyst can be suppressed by adding a reaction inhibitor to obtain a longer pot life. Known reaction inhibitors for platinum group metals include acetylene alcohols such as 2-methyl-3-butyne-2-ol, 3,5-dimethyl-1-hexyne-3-ol, and 1-ethynyl-2-cyclohexanol, diallyl maleate, and tertiary amines such as tetramethylethylenediamine and pyridine.

[0038] ·Composition The UV-curable silicone composition of the present invention contains the above-mentioned components (A) to (C). In particular, the present invention is a UV-curable silicone composition containing the above-mentioned components (A) to (C), wherein the content of organic solvents that volatilize under reduced pressure is 0.5% by mass or less, preferably 0.1% by mass or less, relative to the entire composition. The preferred embodiments of the essential components (A) to (C) are as described above, but components (A) and (B) can be appropriately selected from commercially available or known products according to the desired physical properties. For example, from the viewpoint of controlling the refractive index, it is preferable to introduce phenyl groups into components (A) and (B). In that case, it is preferable to design the cured product to have a refractive index of 1.56 or less.

[0039] The UV-curable silicone composition of the present invention has no particular limitations on its properties, as long as each component is uniformly mixed and it has sufficient fluidity to be applied to a substrate. The viscosity of the composition can be controlled mainly by the viscosity of component (A), and is preferably in the range of 0.1 to 500 Pa·s from the viewpoint of operability. It is more preferable that the viscosity of the composition is in the range of 0.1 to 50 Pa·s. Because the UV-curable silicone composition of the present invention has high stability, its viscosity does not fluctuate much even during long-term storage and it is easy to handle. A composition in which the viscosity of the composition after one week at 80°C under light shielding is 50 Pa·s or less is particularly preferred. Furthermore, UV-curable silicone compositions can be either a one-component composition in which all components are mixed together, or a two-component composition in which components (B) and (C) are blended separately. The choice between a one-component and a two-component composition can be appropriately selected considering factors such as workability and curing conditions, and the method for doing so is well known to those skilled in the art.

[0040] The UV-curable silicone composition of the present invention may contain other known components as long as they do not impair its purpose and effect. Flame retardants, adhesion promoters, heat-resistant agents, diluents, organic solvents, inorganic or organic pigments, etc., may be appropriately added as additives. Furthermore, siloxane resins that do not fall under component (A) or (B) may also be added. Examples of such resins include polyorganosiloxanes having only one curable functional group, and polyorganosiloxanes without curable functional groups, such as dimethylsiloxane. These resins can be used as diluents.

[0041] <Other resins> The UV-curable silicone composition may further contain a siloxane resin other than those corresponding to components (A) and (B). Such a resin can also be used as a diluent to adjust viscosity. Such a siloxane resin may be one of the resins obtained from the combination of the M, D, T, and Q units that has no curable functional group or has only one, particularly the following formula (5): R a R2Si-O-(SiR2O) n -SiR3···(5) (In the formula, R a ,R and n are as defined in formula (2), and R does not have a curable functional group. Siloxanes having only one curable functional group, as shown by formula (6): R3Si-O-(SiR2O) n -SiR3···(6) (In the formula, R and n are as defined in formula (2), and R does not have a curable functional group.) Siloxanes without curable functional groups, as shown in [the formula], can be used. By using such siloxane resins, it is possible to control the hardness of the UV-curable silicone composition when it is cured, as well as the viscosity of the composition, thereby accommodating a wide range of handling requirements and desired physical properties.

[0042] Such resins can be included in an ultraviolet-curable silicone composition in amounts of, for example, 50 parts by mass or less per 100 parts by mass of component (A), more specifically, 0.1 to 50 parts by mass, and more specifically, 1 to 30 parts by mass.

[0043] The composition may further contain a polyorganohydrogensiloxane having two hydrogen atoms bonded to a silicon atom in the molecule. Such a siloxane can function as a chain extender by addition reaction with component (A). An example of such a siloxane is as described for component (B), except that it has two hydrogen atoms bonded to a silicon atom in the molecule. Such a siloxane is the H of general formula (3) or (4) described above. (3-a) R 1 a SiO 1 / 2 or HR 1 SiO 2 / 2 The unit shown is preferably present in two units in the molecule, such that the number of Si-H bonds is 2.

[0044] The siloxane skeleton in this component may be linear, branched, or cyclic, but linear is preferred. Furthermore, the siloxane in this component has both ends independently of each other, R 5 3SiO 1 / 2 The unit is closed, and the intermediate unit is R 5 2SiO 2 / 2 Consists of units only (in the formula, R 5 Each of these is independently a monovalent hydrocarbon group that does not have a hydrogen atom or an aliphatic unsaturated bond, but there are two R groups per molecule. 5It is more preferable that the component is a linear polyorganosiloxane (where the silicon atom is a hydrogen atom). The hydrogen atom bonded to the silicon atom may be located at the end or in the intermediate unit, but it is preferable that it be located at the end. Therefore, as a siloxane of this component, both ends are M H Polymethylhydrogensiloxane is particularly preferred, which is occluded by units (dimethylhydrogensiloxane units) and whose intermediate units consist only of D units (dimethylsiloxane units).

[0045] <Adhesion-enhancing agent> The UV-curable silicone composition may further contain an adhesion promoter, provided that this does not impair the objectives and effects of the present invention. The adhesion promoter is a component that improves the adhesion of the cured product of the composition to a substrate such as glass, metal, or plastic. Examples of adhesion promoters include metal alkoxides, compounds having a hydrolyzable silyl group, compounds having a hydrolyzable silyl group and a reactive organic functional group in one molecule, compounds having a hydrogen atom bonded to a silicon atom and a divalent aromatic group in one molecule, compounds having a hydrogen atom bonded to a silicon atom and a reactive organic functional group in one molecule, and / or partially hydrolyzed condensates thereof. Examples of metal alkoxides include aluminum alkoxides such as aluminum triethoxide, aluminum trippropoxide, and aluminum tributoxide; and titanium alkoxides such as titanium tetraethoxide, titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, titanium tetraisobutoxide, and titanium tetraisopropenyloxide. Examples of organic compounds used as adhesion promoters include amino group-containing silanes, isocyanurates, and carbasilatran compounds. Specific examples include tetraethoxysilane, oligomers of tetramethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, and 3-methacryloxypropylmethyldiethoxysilane. It is preferable to blend these components in amounts of less than 5 parts by mass per 100 parts by mass of the base polymer (A), particularly in order to prevent haze buildup under high temperature and high humidity conditions.

[0046] Further examples of adhesion-improving agents include the following: (E1)Si(OR 3 ) nOrganosilicon compounds having a group and an epoxy group-containing group, and / or partially hydrolyzed condensates thereof, (E2)Si(OR 3 ) n Silane compounds having a group and an aliphatic unsaturated hydrocarbon group, and / or partially hydrolyzed condensates thereof, (E3)Si(OR 4 A tetraalkoxysilane compound represented by 4, and / or a partially hydrolyzed condensate thereof. (E4) Siloxane compounds having at least two hydrogen atoms bonded to a silicon atom in one molecule, and one hydrolyzable group bonded to the siloxane skeleton via a heteroatom-containing structure. (In each of the above formulas, R 3 R represents an alkyl group having 1 to 4 carbon atoms or a 2-methoxyethyl group; 4 (where n is an integer between 1 and 3 carbon atoms, and n is an integer between 1 and 3 carbon atoms)

[0047] (E1), (E2), (E3), and (E4) may each be used individually or in combination of two or more types.

[0048] <<(E1)>> (E1) is introduced into the crosslinked siloxane structure by a co-hydrolysis and condensation reaction between an alkoxy group bonded to a silicon atom and the alkoxy groups bonded to the silicon atoms of (E2) and / or (E3). The epoxy group acts as the part that exhibits adhesiveness, contributing to the improvement of the adhesion of the composition at room temperature, particularly to plastics.

[0049] R 3 Since it provides good adhesion, methyl and ethyl groups are preferred, with methyl groups being particularly preferred. n is preferably 2 or 3. As for epoxy group-containing groups, aliphatic epoxy group-containing groups containing an ether oxygen atom, such as 3-glycidoxypropyl group; and alicyclic epoxy group-containing groups, such as 2-(3,4-epoxycyclohexyl)ethyl group are preferred because they are easy to synthesize, not hydrolyzable, and exhibit excellent adhesion. Si(OR 3 ) nThe group may have two or more elements in the molecule. 3 The number of groups in the molecule is preferably two or more. 3 The group and the epoxy group-containing group may be bonded to the same silicon atom or to different silicon atoms.

[0050] Examples of (E1) include alkoxysilanes containing a 3-glycidoxypropyl group, such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropyl(methyl)dimethoxysilane; alkoxysilanes containing a 2-(3,4-epoxycyclohexyl)ethyl group, such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyl(methyl)dimethoxysilane; partially hydrolyzed condensates of these silanes with n of 2 or more; and carbon / silicon bifunctional siloxanes in which some of the methyl groups of a linear or cyclic methylsiloxane are replaced with a trimethoxysiloxy group or a 2-(trimethoxysilyl)ethyl group and the epoxy group-containing group mentioned above.

[0051] <<(E2)>> (E2) undergoes an addition reaction with (B) during the curing of the composition and is introduced into the siloxane structure crosslinked by the addition reaction with (A) and (B). The alkoxy groups present in the side chains act as adhesive parts, contributing to the improvement of the composition's adhesion at room temperature, particularly its adhesion to metals. Furthermore, the alkoxy groups of (E2) also contribute to the introduction of (E1) and / or (E3) into the crosslinked siloxane structure through co-hydrolysis and condensation reactions with the alkoxy groups of (E1) and / or (E3). (E2) is Si(OR 3 ) n Preferably, it is a silane compound having a group and one aliphatic unsaturated hydrocarbon group, and / or a partially hydrolyzed condensate thereof.

[0052] R 3The group provides good adhesion, so methyl and ethyl groups are preferred, with methyl groups being particularly preferred. n is preferably 2 or 3. The aliphatic unsaturated hydrocarbon group is preferably a monovalent group. In the case of alkenyl groups such as vinyl, allyl, and 3-butenyl, the aliphatic unsaturated hydrocarbon group may be directly bonded to the silicon atom, or, as in 3-acryloxypropyl and 3-methacryloxypropyl, an unsaturated acryloxy group may be bonded to the silicon atom via three or more carbon atoms. As unsaturated hydrocarbon group-containing groups, vinyl groups, methacryloxypropyl groups, etc. are preferred because they are easy to synthesize and handle. Si(OR 3 ) n The group may have two or more elements in the molecule. 3 The number of groups in the molecule is preferably two or more. 3 The group and the aliphatic unsaturated hydrocarbon group may be bonded to the same silicon atom or to different silicon atoms.

[0053] Examples of (E2) include alkenylalkoxysilanes and / or their partial hydrolysis condensates, such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, methylvinyldimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, and methylallyldimethoxysilane; and (meth)acryloxypropyl(methyl)di- and (meth)acryloxypropyltri-alkoxysilanes and / or their partial hydrolysis condensates, such as 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-acryloxypropyl(methyl)dimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-methacryloxypropyl(methyl)dimethoxysilane.

[0054] <<(E3)>> (E3) is a component that further improves the adhesion of the composition to metal at room temperature. 4Examples of alkyl groups include linear or branched alkyl groups such as methyl, ethyl, propyl, and isopropyl. Methyl and ethyl groups are preferred because they are readily available, easy to handle, and significantly improve adhesion. Furthermore, while (E3) can be used as a tetraalkoxysilane compound alone, it is preferable that it be a partially hydrolyzed condensate of a tetraalkoxysilane compound due to its excellent hydrolysis properties and lower toxicity.

[0055] <<(E4)>> (E4) is a siloxane compound having a hydrogen atom bonded to a silicon atom and a hydrolyzable group, functioning as an adhesion promoter. The hydrolyzable group here is bonded to the siloxane skeleton via a structure containing a heteroatom. During the curing of the composition, (E4) undergoes an addition reaction with component (A) and is introduced into the siloxane structure crosslinked by the addition reaction with (A) and (B), contributing to the adhesion of the composition at room temperature as the part that exhibits adhesion. However, components corresponding to (A) or (B) are excluded from this component.

[0056] A "heteroatom-containing structure" is a divalent functional group containing at least one of the following: oxygen, nitrogen, sulfur, or phosphorus. The structure is not particularly limited as long as the skeleton connecting the hydrolyzable group and the siloxane skeleton with the fewest number of atoms contains a heteroatom. Examples of heteroatom-containing structures include those in which at least one of the -CH2- portions of a divalent alkylene group is replaced with an ether (-O-), amino (-NR-; where R is a hydrogen atom or a monovalent hydrocarbon group), sulfide (-S-), sulfonyl (-SO2-), phosphino (-PR-), ester (-O(C=O)-), thioester (-S(C=O)-), etc.

[0057] When used herein, "hydrolyzable group" means a group that can undergo hydrolysis, that is, a group that can be removed from the main skeleton of the compound by hydrolysis. In (E4), there is preferably only one hydrolyzable group in the molecule, and this group is bonded to the siloxane skeleton via a structure containing a heteroatom. Examples of hydrolyzable groups include -OR', -OCOR', -ON=CR'2, -NR'2, -NHR', epoxy, halogen atoms (wherein R' represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms). -OR' (i.e., an alkoxy group) is preferred because it is less likely to cause corrosion to various substrates and is chemically stable as a silicone composition. Examples of R' include unsubstituted alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, and isobutyl groups; and substituted alkyl groups such as chloromethyl groups. Among these, alkyl groups, especially unsubstituted alkyl groups, are preferred, and methyl or ethyl groups are more preferred. In other words, one preferred embodiment is that the hydrolyzable group is an alkoxy group such as a methoxy group, ethoxy group, propoxy group, or butoxy group. The hydroxyl group is not particularly limited, but may be a group formed by the hydrolysis of a hydrolyzable group. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms, of which chlorine is preferred.

[0058] (E4) consists of a hydrogen atom bonded to a silicon atom and the following formula bonded to a silicon atom: [ka] Examples of organosilicon compounds having the structure shown are provided. (In each of the above formulas, Q 1 Q represents a linear or branched alkylene group that forms a carbon chain having two or more carbon atoms between a silicon atom and an ester bond; 2 R represents a linear or branched alkylene group that forms a carbon chain having three or more carbon atoms between an oxygen atom and a silicon atom of the structure; 3(This represents an alkyl group having 1 to 4 carbon atoms or a 2-methoxyethyl group.)

[0059] Q 1 Ethylene groups and 2-methylethylene groups are preferred because they are easy to synthesize and handle. 2 Trimethylene groups are preferred because they are easy to synthesize and handle. 3 Because it provides good adhesion and the alcohol produced by hydrolysis is easily volatile, methyl and ethyl groups are preferred, with methyl groups being particularly preferred.

[0060] In the above formula, the hydrogen atom and the structure are preferably bonded to separate silicon atoms for ease of synthesis. Therefore, the basic part of (E4) is preferably a chain, branched, or cyclic siloxane skeleton. The number of Si-H bonds in (E4) is one or any number, and in the case of a cyclic siloxane compound, two or three are preferred.

[0061] Examples of (E4) include reaction products of cyclic organohydrogenpolysiloxanes with silane compounds having acrylic or methacrylic groups. Such compounds are preferred because their synthesis routes are established, and because it is easy to control the number of Si-H bonds and hydrolyzable groups per molecule, thereby facilitating uniform control of the overall properties of the composition. More specific examples of (E4) include the following compounds. [ka] Other components (E4) include the following: [ka] Examples include compounds having a hydrogen atom bonded to a silicon atom and a reactive organic functional group within a single molecule.

[0062] <<Other adhesion promoters>> Other adhesion-imparting agents besides (E1) to (E4) include aluminum alkoxides such as aluminum triethoxide, aluminum trippropoxide, and aluminum tributoxide; titanium alkoxides such as titanium tetraethoxide, titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, titanium tetraisobutoxide, and titanium tetraisopropenyloxide; zirconium acylates such as zirconium octanoate, zirconium tetra(2-ethylhexanoate), and zirconium stearate; zirconium alkoxides such as n-propyl zirconate and n-butyl zirconate (excluding zirconium chelates); and metal alkoxides such as zirconium chelates such as tributoxyzirconium acetylacetonate, dibutoxyzirconium bis(ethylacetoacetate), zirconium tetraacetylacetonate, zirconium monoacetylacetonate, and zirconium ethylacetoacetate.

[0063] Other adhesion-improving agents include, [ka] [ka] Compounds having a hydrolyzable silyl group and a reactive organic functional group in one molecule, and / or partially hydrolyzed condensates thereof (excluding those falling under (E1) to (E4)); [ka] Examples include compounds having a hydrogen atom bonded to a silicon atom and a divalent aromatic group in a single molecule (wherein k is an integer from 1 to 3). The adhesive strength can be further enhanced by using other adhesion promoters in combination.

[0064] The adhesion promoter may be included in the UV-curable silicone composition in amounts of, for example, 10 parts by mass or less per 100 parts by mass of component (A), more specifically, 0.01 to 10 parts by mass, and more specifically, 0.1 to 5 parts by mass. The adhesion promoter may be used alone or in a mixture of two or more types.

[0065] <Solvent> The UV-curable silicone composition may contain an organic solvent that is liquid at room temperature and pressure and volatilizes under reduced pressure, to the extent that it does not impair the effects of the present invention. The solvent used to dissolve the platinum complex of component (C) above can also be used as the solvent. In this case, the UV-curable silicone composition can be dissolved in a suitable solvent at a desired concentration depending on its application and purpose. Including a solvent can adjust the viscosity of the curable composition and improve its handling properties, but from the viewpoint of suppressing the content of volatile components, it is preferable to use a small amount of solvent, and more preferably to use no solvent at all. That is, the UV-curable silicone composition of the present invention preferably contains 1% by mass or less of an organic solvent that is liquid at room temperature and pressure and volatilizes under reduced pressure, and more preferably 0% by mass, relative to the total composition.

[0066] One aspect of the present invention is the above-mentioned ultraviolet-curable silicone composition for bonding substrates. Accordingly, the present invention provides an adhesive containing the above-mentioned ultraviolet-curable silicone composition. The adhesive preferably contains an adhesion promoter in addition to the above-mentioned components (A) to (C).

[0067] [Method for manufacturing adhesive members] One aspect of the present invention is a method for manufacturing an adhesive member, comprising the step of applying the ultraviolet-curable silicone composition to a first substrate layer, and (i) A step of bonding a first substrate layer to which an ultraviolet-curable silicone composition has been applied to a second substrate layer via a layer of ultraviolet-curable silicone composition; (ii) A step of depressurizing the ultraviolet-curable silicone composition applied to the first substrate layer under a pressure below atmospheric pressure; and (iii) A step of irradiating the UV-curable silicone composition applied to the first substrate layer with ultraviolet light; This concerns methods, including in no particular order.

[0068] ·Base material The substrate to which the adhesive containing the UV-curable silicone composition of the present invention is applied is not particularly limited in material. Suitable substrates include metals such as aluminum, copper, nickel, iron, brass, and stainless steel; engineering plastics such as epoxy resin, polyester resins such as polyethylene terephthalate and polybutylene terephthalate (PBT) resin, polycarbonate resin, acrylic resin, polyimide resin, phenolic resin, polyamide resin, polyphenylene sulfide (PPS) resin, and modified polyphenylene ether (PPE) resin; and glass. Of these, it is preferable to use a substrate selected from the group consisting of epoxy resin, polyester resin, polycarbonate resin, acrylic resin, polarizing plate, and glass. If necessary, the walls of the voids, etc., may be subjected to conventional treatments such as primer treatment, corona treatment, plasma treatment, and excimer treatment according to standard methods. In addition, in the method of the present invention, a first substrate to which the UV-curable silicone composition is applied and a second substrate to which the first substrate is bonded are used, but the first and second substrates to be bonded may be made of different materials.

[0069] • Application to substrates Adhesives containing UV-curable silicone compositions are applied to the areas to be bonded on the surface of a component, including a substrate, to a predetermined thickness by methods such as dropping, injection, casting, extrusion from a container, bar coating, roll coating, slit die coating, screen printing, dipping, brush coating, spraying, and dispensing. In particular, coating by slit die coating, which is suitable for application as a uniform thin film, is used as a method of application to the substrate. These methods are known to those skilled in the art. The composition may be applied evenly and uniformly to the entire surface of the component, or it may be applied unevenly or partially, such as in linear, stripe, or dot patterns. The application thickness of the composition is usually 0.01 to 3 mm, preferably 0.05 to 2 mm. When applied to a substrate, the UV-curable silicone composition can be used as either a one-component or two-component adhesive. When used as a two-component adhesive, it is preferable to mix it using a commonly used mixing device such as a static mixer before applying it to the substrate.

[0070] The method of the present invention includes the step of (i) bonding a first substrate layer to which an ultraviolet-curable silicone composition is applied to a second substrate layer via a layer of ultraviolet-curable silicone composition. The first substrate to which the ultraviolet-curable silicone composition is applied is bonded to the second substrate to obtain a bonded member. The bonding method is not particularly limited, and any means can be used. The ultraviolet-curable silicone composition may also be applied to the second substrate. In an article using the ultraviolet-curable silicone composition of the present invention as an adhesive, it is sufficient that the composition and each substrate have an adhesive portion, and the shape, thickness, etc., are not particularly limited. Furthermore, the bonding step may be carried out under reduced pressure or ultraviolet irradiation conditions as described later.

[0071] • Depressurization process The method of the present invention includes (ii) a step of depressurizing the ultraviolet-curable silicone composition applied to the first substrate layer under a pressure below atmospheric pressure. The object subjected to depressurization here may be the first substrate to which the ultraviolet-curable silicone composition has been applied before the second substrate is bonded to it, or it may be a bonded member to which the second substrate has been bonded. The conditions for depressurization are not particularly limited as long as they are sufficient to remove gases such as air and volatile solvents contained in the ultraviolet-curable silicone composition. The conditions for the depressurization step depend on the size of the bonded member, etc., but the pressure is below atmospheric pressure, preferably 30 kPa or less, more preferably 10 kPa or less. The time for depressurization is 10 seconds or more, preferably 30 seconds or more, more preferably 1 minute or more, and can usually be completed in a time of 5 minutes or less. The pressure and time conditions can be combined within a range that can achieve the objective. In addition, in order to efficiently remove air bubbles and the like, a heat treatment may be performed separately or simultaneously within the range of the heat resistance of the substrate.

[0072] ·Curing process The method of the present invention includes (iii) irradiating a UV-curable silicone composition applied to a first substrate layer with ultraviolet light. The first substrate or bonded member to which the composition of the present invention is applied can be cured and bonded by irradiation with ultraviolet light. The amount of ultraviolet light irradiated is 100 to 10,000 mJ / cm². 2 Preferably, and more preferably, 300 to 6,000 mJ / cm² 2 And more preferably 500 to 4,000 mJ / cm². 2The irradiation dose is a measured value of UVA. Here, UVA refers to ultraviolet light in the range of 315 to 400 nm. The composition exhibits good curability when irradiated with ultraviolet light having a wavelength range of, for example, 250 to 450 nm. In particular, the UV-curable silicone composition of the present invention exhibits good curability even when irradiated with relatively low-energy ultraviolet light in the wavelength range of 365 nm or higher. Examples of light sources that emit ultraviolet light of this wavelength include high-pressure mercury lamps (UV-7000) and metal halide lamps (UVL-4001M3-N1) manufactured by Ushio Inc., metal halide lamps (JM-MTL 2KW) manufactured by JM tech Co., Ltd. (South Korea), ultraviolet irradiation lamps (OSBL360) manufactured by Mitsubishi Electric Corporation, ultraviolet irradiation units (UD-20-2) manufactured by Japan Storage Battery Co., Ltd., fluorescent lamps (FL-20BLB) manufactured by Toshiba Corporation, H-bulbs, H-plus bulbs, V-bulbs, D-bulbs, Q-bulbs, and M-bulbs manufactured by Heraeus, and LED lamps (HLDL-155UV) manufactured by CCS Corporation.

[0073] The curing time of the composition is generally 30 minutes or less, although this depends on the amount of ultraviolet light irradiated. Whether the composition has cured can be determined by visual inspection or by qualitative evaluation, such as whether the surface is tack-free (whether it feels sticky to the touch). It can also be quantitatively evaluated by measuring the storage modulus G' and the loss modulus G''. For example, under conditions of 23°C after ultraviolet irradiation, if the time it takes for the storage modulus G' and the loss modulus G'' to become equal is 30 minutes or less, it is preferable because the curing time is short and the handling is excellent.

[0074] The method of the present invention includes the step of applying the ultraviolet-curable silicone composition to a first substrate layer, and is a method that includes the steps (i), (ii), and (iii) described above. The method of the present invention only needs to include these three steps, and the order in which the steps (i), (ii), and (iii) are performed is not specified and can be performed in any order. For example, the steps (i), (ii), and (iii) can be performed in the order of (i), (ii), and (iii), or in the order of (iii), (ii), and (i). These steps may be performed sequentially, or two or three steps may be performed simultaneously, for example, by performing bonding under reduced pressure.

[0075] One aspect of the present invention is a component having a layer bonded with the UV-curable silicone composition. The UV-curable silicone composition of the present invention uses a low-volatility platinum catalyst, which allows the curing reaction to proceed smoothly. As a result, articles obtained using the component of the present invention have excellent durability, including water resistance of the bonded surface and sealed area, and can be used as various components in the field of electronic materials. Furthermore, it has good curability and can therefore be used, for example, as an adhesive for bonding image display devices such as liquid crystal, plasma, and organic EL. The component of the present invention contains a non-volatile platinum catalyst in the adhesive layer containing the UV-curable silicone composition, and its amount can be measured. The amount of platinum in the adhesive layer depends on the concentration of the platinum catalyst in the composition, but is generally between 0.1 ppm and 50 ppm. [Examples]

[0076] The compositions of the present invention will be described more specifically through the following examples, but the present invention is not limited to the embodiments of these examples.

[0077] The materials used in the examples and comparative examples are as follows: Here, M, D, D HThe meanings of the symbols used to describe siloxane compounds are as described above. Unless otherwise specified, the amount of each composition is expressed in parts by mass. <Polyorganosiloxane resin: component (A)> α,ω-divinylpolydimethylsiloxane; viscosity 3 Pa·s <Organohydrogenpolysiloxane: Ingredient (B)> MD 17 D H 23 Organohydrogenpolysiloxane represented by M <Platinum catalyst: component (C)> [1-methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatinum or [1-methyl-3-(9'-phenanthryl)-cyclopentadienyl]trimethylplatinum <Silane compound (D)>DD H A cyclic siloxane represented by 3 is subjected to an addition reaction with 3-methacryloxypropyltrimethoxysilane.

[0078] [Test Example 1: GelTime] Using a viscoelasticity measuring device (MCR302) (manufactured by Anton Paar Japan Co., Ltd.), the composition was extruded onto a lower parallel quartz plate at 23°C. The composition was then sandwiched between upper parallel plates (8 mm in diameter) to a thickness of 300 μm, and irradiated with an LED at an intensity of 100 mW and a wavelength of 365 nm for 10 seconds. The storage modulus G' (Pa) and loss modulus G'' (Pa) were measured every second at a frequency of 1 Hz and a strain of 1%. The time (in minutes) until the storage modulus G' and loss modulus G'' became equal was defined as the G'G'' crossover point and the curing time of the composition.

[0079] [Test Example 2: Gel Time After Decompression] The composition was coated to a thickness of 90 μm, and the thin film was left to stand under 1 kPa for 5 minutes. After returning to atmospheric pressure, the gel time of the treated composition was measured using the method described in Test Example 1.

[0080] [Test Example 3: Tack Free Time] Using a 405nm wavelength LED irradiator (CLDL-120V0-NWPSC, manufactured by CCS), ultraviolet light at an irradiation intensity of 200mW was applied for 20 seconds. The surface was touched every 30 seconds, and the time it took for curing to occur was determined as the tack-free time.

[0081] <Preparation of UV-curable silicone composition> [Example 1] [1-methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatin was added to polyorganosiloxane resin (A) to a weight ratio of 0.05%, and the mixture was heated in an oven at 95°C and then stirred to obtain a platinum catalyst solution. The polyorganosiloxane resin (A), organohydrogenpolysiloxane (B), platinum catalyst solution, and silane compound (D) were mixed in the proportions shown in the table to obtain composition 1.

[0082] [Example 2] An ultraviolet-curable silicone composition was prepared in the same manner as in Example 1, except that the platinum catalyst was replaced with the same amount of [1-methyl-3-(9'-phenanthryl)-cyclopentadienyl]trimethylplatinum solution in terms of platinum element.

[0083] [Comparative Example 1] An ultraviolet-curable silicone composition was prepared in the same manner as in Example 1, except that the platinum catalyst was replaced with methylcyclopentadienyltrimethylplatinum ([MeCpPtMe3]) in the same amount as the platinum element equivalent.

[0084] [Comparative Example 2] Platinum catalyst is equivalent to the same amount of pentamethylcyclopentadienyltrimethylplatinum ([Cp * A UV-curable silicone composition was prepared in the same manner as in Example 1, except that it was changed to PtMe3).

[0085] [Comparative Example 3] When attempting to prepare a platinum solution using the same method as in Example 1, bisacetylacetonatoplatinum ([Pt(acac)2]) did not show solubility. Therefore, a 0.05% solution was prepared using 2-2-methoxyethoxyethanol to serve as the platinum catalyst solution. An ultraviolet-curable silicone composition was prepared in the same manner as in Example 1, except that the platinum catalyst was replaced with the same amount of bisacetylacetonatoplatinum ([Pt(acac)2]) in terms of platinum element. The results of Test Examples 1 to 3 in each example and comparative example are shown in Table 1.

[0086] [Table 1]

[0087] Table 1 shows that the UV-curable silicone composition of the present invention using a specific platinum catalyst exhibited a short gelation time and excellent curability. Furthermore, its curability was not impaired even after being subjected to reduced pressure treatment, making it suitable for the manufacture of components that include a reduced pressure treatment step during bonding. In addition, this UV-curable silicone composition using a specific platinum catalyst showed excellent curability even when irradiated with long-wavelength ultraviolet light. On the other hand, compositions using other platinum catalysts cured, but the time to gelation was somewhat longer, and this tendency became even stronger when subjected to reduced pressure treatment.

Claims

1. A method for manufacturing adhesive members, (A) An organopolysiloxane containing at least two unsaturated groups bonded to silicon atoms in one molecule, wherein the following formula (2): (R a ) 3-p R p Si-O-(Si(R) r (R a ) 2-r O) n -SiR q (R a ) 3-q ...(2) (In the formula, Ra and a are each unsaturated groups, Each R is independently a monovalent alkyl group. p and q are independently 0, 1, or 2. r is independently 0, 1, or 2. n is a number representing a viscosity of 0.1 to 500 Pa·s at 23°C. Linear polyorganosiloxanes represented by, (B) Organohydrogenpolysiloxane having at least three hydrogen atoms bonded to a silicon atom in one molecule, (C) A UV-activated hydrosilylated platinum catalyst having a cyclopentadienyl group bonded to a condensed aromatic hydrocarbon group as a ligand, and Each molecule has at least two hydrogen atoms bonded to a silicon atom, and the following formula is bonded to the silicon atom: 【Chemistry 1】 (In the formula, Q1 represents a linear or branched alkylene group that forms a carbon chain having two or more carbon atoms between a silicon atom and an ester bond; Q2 represents a linear or branched alkylene group that forms a carbon chain having three or more carbon atoms between an oxygen atom and a silicon atom of the said structure; R3 represents an alkyl group having 1 to 4 carbon atoms or a 2-methoxyethyl group.) Siloxane compounds having the structure shown The process includes the step of applying an ultraviolet-curable silicone composition containing to a first substrate layer, (i) A step of bonding a first substrate layer to which an ultraviolet-curable silicone composition has been applied to a second substrate layer via a layer of ultraviolet-curable silicone composition; (ii) A step of reducing the pressure of the ultraviolet-curable silicone composition applied to the first substrate layer under a pressure below atmospheric pressure; and (iii) A step of irradiating the UV-curable silicone composition applied to the first substrate layer with ultraviolet light; A method in which the steps (iii), (ii), and (i) are performed in that order.

2. The method according to claim 1, wherein step (iii) is a step of irradiating with ultraviolet light having a wavelength of 365 nm or more.

3. The method according to claim 1, wherein the unsaturated group of the organopolysiloxane in (A) is an alkenyl group.

4. The method according to claim 1, wherein the ratio of the amount of substance (H / Vi ratio) of hydrogen directly bonded to silicon in (B) to the unsaturated group in (A) is in the range of 0.2 to 2.

0.

5. The method according to claim 1, wherein the UV-activated hydrosilylated platinum catalyst of (C) is [1-methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatinum or [1-methyl-3-(9'-phenanthryl)-cyclopentadienyl]trimethylplatinum.

6. The method according to any one of claims 1 to 5, wherein the first or second substrate is selected from the group consisting of epoxy resin, polyester resin, polycarbonate resin, acrylic resin, polarizing plate, and glass.

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