Ultraviolet active silicone composition and method for manufacturing a bonding member using the same

Abstract

A method for manufacturing an adhesive component is provided, comprising applying a UV-curable silicone composition to a first substrate layer, the UV-curable silicone composition comprising: (A) an organopolysiloxane containing unsaturated groups; (B) an organohydropolysiloxane; and (C) a UV-active platinum hydrogen silane catalyst having a cyclopentadienyl group bonded to a fused aromatic hydrocarbon group as a ligand. The method for manufacturing the adhesive component further comprises, in any order: (i) a step of bonding the first substrate layer to which the UV-curable silicone composition is applied to a second substrate layer via a layer of the UV-curable silicone composition; (ii) a step of depressurizing the UV-curable silicone composition applied to the first substrate layer under a pressure less than atmospheric pressure; and (iii) a step of irradiating the UV-curable silicone composition applied to the first substrate layer with ultraviolet light. Additionally, an adhesive formed from a silicone composition with excellent curability and an adhesive component with high adhesion and high reliability as a component are provided.

Description

Technical Field

[0001] The present invention relates to a UV-active silicone composition as an adhesive and a method for manufacturing an adhesive component using the UV-active silicone composition. Background Technology

[0002] In recent years, flat-panel image display devices such as liquid crystal displays (LCDs), plasma displays, and organic EL displays have attracted attention. Flat-panel image display devices typically have a display area (image display section) between a pair of substrates, at least one of which is transparent, such as glass. This display area arranges multiple pixels, including semiconductor layers, phosphor layers, or light-emitting layers constituting active elements, in a matrix configuration. Typically, this display area (image display section) is hermetically sealed around a protective portion formed of an optical plastic such as glass or acrylic resin with an adhesive. Here, as the UV-curable resin composition used as the adhesive, a UV-curable acrylic resin and a UV-curable silicone resin composition are used (Patent Document 1).

[0003] UV-curable silicone resin compositions can be used for hydrosilylation reactions based on platinum catalysts. Although it is sometimes necessary to fully cure the parts that are not reached by UV light, they are used as compositions that can be cured under relatively mild conditions (Patent Documents 2-5).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2008-282000

[0007] Patent Document 2: International Publication No. 2023 / 112925

[0008] Patent Document 3: Japanese Patent Publication No. 2023-514372

[0009] Patent Document 4: Japanese Patent Application Publication No. 2020-158548

[0010] Patent Document 5: Japanese Patent Application Publication No. 2001-89491 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] UV-curable silicone compositions can effectively and uniformly cure at room temperature and are used in optical adhesives and as sealants for LEDs. In bonding components, to achieve uniform and good adhesion by removing highly volatile substances such as air bubbles and solvents sometimes contained in the adhesive, the bonding process sometimes includes a process under reduced pressure. However, according to the research of the inventors, if the conventional UV-curable silicone compositions used in the aforementioned patent documents are placed under reduced pressure, the curing performance sometimes decreases. In particular, with the recent trend towards thinner image display devices, the thickness of the adhesive layer also needs to be reduced; however, when the adhesive layer is thin, the decrease in curing performance during reduced pressure treatment is significant. The curing performance of UV-curable silicone compositions can also affect adhesion, and there is a need for compositions that improve in this respect.

[0013] The purpose of this invention is to improve the above-mentioned problems, provide an adhesive formed from an organosilicon composition with excellent curability, and provide an adhesive component with high adhesion and high reliability as a component, as well as a method for manufacturing the same.

[0014] Methods for solving problems

[0015] According to the researchers of the present invention, if conventional UV-curable silicone compositions are placed under reduced pressure, a portion of the platinum catalyst used in the curing reaction may volatilize. Therefore, to solve this problem, a suitable catalyst was discovered through catalyst design. Specifically, platinum complexes having a cyclopentadienyl group as a ligand, wherein the cyclopentadienyl group has a fused-ring aromatic hydrocarbon as a substituent, were found to be effective as catalysts.

[0016] Invention Effects

[0017] According to the present invention, an adhesive formed from an organosilicon composition with excellent curability is provided, as well as an adhesive component with high adhesion and high reliability as a component, and a method for manufacturing the same are provided. That is, the present invention relates to the inventions described in the following embodiments.

[0018] [1] A method for manufacturing an adhesive component, comprising the step of applying a UV-curable silicone composition to a first substrate layer, wherein the UV-curable silicone composition comprises:

[0019] (A) An organopolysiloxane containing at least two unsaturated groups bonded to silicon atoms in one molecule;

[0020] (B) An organohydrogen polysiloxane having at least three hydrogen atoms bonded to silicon atoms in one molecule; and

[0021] (C) A UV-active platinum hydrogen silane catalyst with a cyclopentadienyl group bonded to a fused aromatic hydrocarbon group as a ligand.

[0022] Furthermore, the method for manufacturing the aforementioned adhesive component includes, in any order:

[0023] (i) A process of bonding a first substrate layer to a second substrate layer via a layer of a UV-curable silicone composition.

[0024] (ii) A process of depressurizing the UV-curable silicone composition applied to the first substrate layer at a pressure less than atmospheric pressure; and

[0025] (iii) A process of irradiating the UV-curable silicone composition applied to the first substrate layer with ultraviolet light.

[0026] [2] According to the method described in [1] above, the above processes (i), (ii), and (iii) are performed in the order of process (ii), process (iii), and process (i).

[0027] [3] According to the method described in [1] above, the above-mentioned processes (i), (ii), and (iii) are performed in the order of process (iii), process (ii), and process (i).

[0028] [4] According to any one of the methods described in [1] to [3] above, wherein the above step (iii) is a step of irradiating with ultraviolet light having a wavelength of 365 nm or more.

[0029] [5] According to any one of [1] to [4] above, wherein the above-mentioned component (A) is a linear organopolysiloxane.

[0030] [6] According to any one of the methods described in [1] to [5] above, wherein the unsaturated group of the organopolysiloxane in (A) above is an alkenyl group.

[0031] [7] According to any one of [1] to [6] above, the molar ratio (H / Vi ratio) of the hydrogen directly bonded to silicon contained in (B) above to the unsaturated group contained in (A) above is in the range of 0.2 to 2.0.

[0032] [8] According to any one of [1] to [7] above, wherein the ultraviolet-active hydrogenated silane platinum catalyst of (C) above is [1-methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatinum or [1-methyl-3-(9'-phenanthyl)-cyclopentadienyl]trimethylplatinum.

[0033] [9] According to any one of [1] to [8] above, the first substrate or the second substrate is selected from epoxy resin, polyester resin, polycarbonate resin, acrylic resin, polarizing plate, and glass.

[0034]

[10] An ultraviolet-curable silicone composition for bonding a substrate, comprising: (A) an organopolysiloxane containing at least two unsaturated groups bonded to silicon atoms in one molecule;

[0035] (B) An organohydrogen polysiloxane having at least three hydrogen atoms bonded to silicon atoms in one molecule;

[0036] (C) A UV-active platinum hydrogen silane catalyst with a cyclopentadienyl group bonded to a fused aromatic hydrocarbon group as a ligand.

[0037]

[11] According to the ultraviolet-curable organosilicon composition described in

[10] above, wherein the ultraviolet-active hydrosilyl platinum catalyst of (C) above is [1-methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatinum or [1-methyl-3-(9'-phenanthyl)-cyclopentadienyl]trimethylplatinum.

[0038]

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

[10] or

[11] above.

[0039]

[13] A UV-curable silicone composition comprising:

[0040] (A) An organopolysiloxane containing at least two unsaturated groups bonded to silicon atoms in one molecule;

[0041] (B) An organohydrogen polysiloxane having at least three hydrogen atoms bonded to silicon atoms in one molecule;

[0042] (C) A UV-active platinum hydrogen silane catalyst with a cyclopentadienyl group bonded to a fused aromatic hydrocarbon group as a ligand.

[0043] The content of organic solvents that are liquid at room temperature and pressure and evaporate under reduced pressure relative to the composition as a whole is 0 by mass. Detailed Implementation

[0044] Hereinafter, the present invention will be described in detail item by item, including the composition for bonding substrates, bonding methods, etc. It should be noted that in this specification, the "~" indicating a numerical range is used to mean that the values ​​described before and after it are both lower and upper limits.

[0045] When used in this specification, "organic group" refers to a carbon-containing group. The valence of an organic group is indicated by setting n to any natural number and denoteing it as "n-valent". Thus, for example, "monovalent organic group" refers to a carbon-containing group having only one bond. Elements other than carbon can also have bonds. Even when the valence is not explicitly stated, those skilled in the art can determine the appropriate valence from the context.

[0046] When used in this specification, "hydrocarbon group" refers to a group containing carbon and hydrogen, obtained by removing at least one hydrogen atom from the molecule. There is no particular limitation on the hydrocarbon group; examples include hydrocarbon groups with 1 to 20 carbon atoms that can be replaced by one or more substituents, such as aliphatic hydrocarbon groups and aromatic hydrocarbon groups. The aforementioned "aliphatic hydrocarbon group" can be any of the following: linear, branched, or cyclic; and it can be any of the following: saturated or unsaturated. Furthermore, the hydrocarbon group can contain one or more ring structures. It should be noted that the hydrocarbon group can also 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, or carbonyl groups, at its terminal or in the molecular chain.

[0047] When used in this specification, the term "hydrocarbon group" is not particularly limited, and examples include: halogen atoms; and atoms selected from C that can be substituted by one or more halogen atoms. 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 3-10 cycloalkyl, C 3-10 Unsaturated cycloalkyl groups, 5-10 membered heterocyclic groups, 5-10 membered unsaturated heterocyclic groups, C 6-10 Groups in aryl and 5- to 10-membered heteroaryl groups.

[0048] In this specification, alkyl and phenyl groups may be unsubstituted or substituted unless otherwise specified. Substituents for this group are not particularly limited; examples include those selected from halogen atoms, C atoms, and C atoms. 1-6 Alkyl, C 2-6 alkenyl and C 2-6 One or more groups in the alkynyl group.

[0049] [UV-curable silicone composition]

[0050] ·Ingredients (A)

[0051] In the UV-curable silicone composition of the present invention, component (A) comprises at least one organopolysiloxane containing at least two unsaturated groups bonded to silicon atoms in one molecule. Component (A) functions as the base polymer of the UV-curable silicone composition. The unsaturated groups can be present at any position in the polysiloxane molecule. For example, unsaturated groups can be present at the ends of the molecule, or they can exist as side chains at sites other than the ends. In the case of linear polysiloxanes, it is preferable that at least one unsaturated group is present at each end of the molecular backbone of component (A). Furthermore, in this specification, the molecular backbone of component (A) refers to the longest bonded chain in the molecule of component (A).

[0052] 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) described later; alkenyl is a representative example. The unsaturated group in the organopolysiloxane of component (A) is preferably alkenyl. The type of alkenyl group is not particularly limited as long as it has a carbon-carbon double bond and is capable of undergoing an addition reaction. The number of carbon atoms in the alkenyl group is preferably 2 to 20, more preferably 2 to 8, and more preferably 2 to 6. The alkenyl group can 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 arbitrary. From a reactivity perspective, the carbon-carbon double bond is preferably located at the end of the group. As a preferred example of an alkenyl group, vinyl groups are advantageous for the easy synthesis of polyorganosiloxanes.

[0053] There are no particular restrictions on the molecular skeleton of component (A) as long as it is based on siloxane bonds. The siloxane in the molecular skeleton can be linear, branched, cyclic, or a combination thereof, and can also form a molecular skeleton with a three-dimensional extended structure. As component (A), a linear organopolysiloxane is preferred. Furthermore, the siloxane skeleton can also be interrupted by divalent organic groups. Herein, when describing the structure of siloxane compounds in this specification, the structural units of siloxane compounds are sometimes referred to by the following abbreviations. Hereinafter, these structural units are sometimes referred to as "M unit," "D unit," etc.

[0054] M:-Si(CH3)3O 1 / 2

[0055] M H :-SiH(CH3)2O 1 / 2

[0056] M Vi :-Si(CH=CH2)(CH3)2O 1 / 2

[0057] D: Si(CH3)2O 2 / 2

[0058] D H :SiH(CH3)O 2 / 2

[0059] T: Si(CH3)O 3 / 2

[0060] Q: SiO 4 / 2

[0061] In this specification, siloxane compounds are compounds constructed by combining the above-described structural units. They may also include structural units in which the methyl group of the above-described structural units is substituted with other groups such as halogens like fluorine or hydrocarbon groups like phenyl groups. In this case, to express a state of substituent substitution, the phenyl-substituted D unit is sometimes described as D... Ph Additionally, for example, in denoted as D... Ph 20 D 20 In this context, the statement refers to the presence of a total of 20 phenyl groups within 40 D units. This statement does not imply that there are a total of 20 D units. Ph The unit is followed by 20 consecutive D units. Each unit is understood to be arbitrarily arranged and may contain SiPh2O. 2 / 2 (represented as D) Ph2 The structural unit shown is ). Siloxane compounds can achieve various three-dimensional structures through T units or Q units, but component (A) can take the form of a linear molecular skeleton formed by arbitrarily combining the above M and D units.

[0062] In one aspect of the invention, as component (A), there is no particular limitation as long as it is a substance having an average of two or more unsaturated groups, particularly alkenyl groups, bonded to silicon atoms in a molecule, and capable of forming a network structure by an addition reaction with the hydride silyl (Si-H group) of component (B) described later. Component (A) is typically a siloxane unit containing unsaturated groups as shown in general formula (1) in a molecule.

[0063] (R) 1 ) m (R) 2 ) n SiO （4-m-n） / 2 (1)

[0064] (In the formula,

[0065] R 1 It is an unsubstituted or substituted monovalent hydrocarbon group that does not have an aliphatic unsaturated bond;

[0066] R 2 It is an unsaturated group, preferably an alkenyl group;

[0067] m is an integer from 0 to 2;

[0068] n is an integer from 1 to 3, where m + n is from 1 to 3.

[0069] As one specific example of component (A), a linear polyorganosiloxane as shown in formula (2) below can be exemplified.

[0070] (R) a ) 3-p R p Si-O-(Si(R)) r (R) a ) 2-r O) n SiR q (R) a ) 3-q ···(2)

[0071] (In the formula,

[0072] R a Each group is independently unsaturated, preferably an alkenyl group.

[0073] R are each an independent monovalent organic group.

[0074] p and q are each independently 0, 1, or 2.

[0075] r can be 0, 1, or 2 independently.

[0076] n is the number that makes the viscosity at 23°C between 0.1 and 500 Pa·s.

[0077] R is preferably a group having a hydrocarbon group, particularly an alkyl, alkenyl, or aryl group. From the viewpoint of controlling physical properties such as refractive index, at least a portion of R can be an aryl group such as phenyl. From the perspective of ease of acquisition, it is preferable to use a polyorganosiloxane in which R is entirely methyl, but from the perspective of adjusting the refractive index, it is preferable that 1 to 40 mol% of R is C6 to C4. 12 Aryl groups, considering viscosity and thixotropy, preferably have 1-20 mol% of C6-C6 in R. 12 Aryl. Regarding the position of the unsaturated group (alkenyl), it is preferred to be a polyorganosiloxane with r=2 in the above formula (2), that is, a linear polyorganosiloxane with at least one unsaturated group (alkenyl) at each end of the molecule.

[0078] As a polyorganosiloxane having unsaturated groups, it is preferred to be a polyorganosiloxane having p and q = 2 and r = 2 in the above formula (2), that is, having only one unsaturated group at each end of the molecule, for a total of two unsaturated groups, preferably alkenyl, and especially vinyl. Commercially available polyorganosiloxanes can be used as such component (a). Alternatively, polyorganosiloxanes with curable functional groups introduced by known reactions can also be used. Regarding component (A), depending on the position or type of substituents, degree of polymerization, etc., only one compound can be used, or two or more compounds can be mixed. Since component (A) is a polyorganosiloxane, it can also be a mixture of polyorganosiloxanes with various degrees of polymerization.

[0079] The amount of component (A) is not particularly limited as long as the UV-curable silicone composition is within a manageable viscosity range. Based on the amount of component (A), the amounts of other components can be appropriately set within the preferred ranges shown below.

[0080] • Ingredient (B)

[0081] The UV-curable silicone composition of the present invention contains a compound (hereinafter, sometimes simply referred to as "component (B)") that is reactive with the curable functional groups of component (A) as a crosslinking agent. By including the crosslinking agent, the physical properties of the cured product obtained from the curable composition, such as tensile strength and elastic modulus, become good. As component (B), an organohydrogen polysiloxane having at least three hydrogen atoms (Si-H bonds) bonded to silicon atoms in one molecule as crosslinking groups is used. Examples of component (B) include organohydrogen polysiloxanes obtained by combining any number and type of structural units shown in the following formula, wherein the total number of Si-H bonds is 3 or more.

[0082] (H) （3-a） R 1 a SiO 1 / 2 (M) H unit)

[0083] (R) 1 3SiO 1 / 2 )

[0084] (HR) 1 SiO 2 / 2 (D) H unit)

[0085] (R) 1 2SiO 2 / 2 )

[0086] (HSiO) 3 / 2 )

[0087] (R) 1 SiO 3 / 2 )

[0088] (SiO) 4 / 2 )

[0089] (In the above formulas, R) 1 Each independently represents an unsubstituted or substituted monovalent hydrocarbon group without an aliphatic unsaturated bond, where a is 1 or 2.

[0090] As an example of a preferred component (B), a linear organohydrogen polysiloxane with Si-H bonds in the portion other than the ends of the molecular chain, as shown in the following formula (3), can be cited.

[0091] (R) 1 3SiO 1 / 2 )2 (HR) 1 SiO 2 / 2 ) c (R) 1 2SiO 2 / 2 ) d ···(3)

[0092] (where R) 1 (a is as defined above, c is a number greater than 3, and d is a number greater than 0.)

[0093] Component (B) has at least three Si-H bonds per molecule that serve as crosslinking groups, with at least one bond in each side chain. Therefore, it can form a network structure through a crosslinking reaction. Component (B) can be used alone or in combination with two or more components.

[0094] R 1 Each independently represents an unsubstituted or substituted monovalent hydrocarbon group that does not possess an aliphatic unsaturated bond. As R 1 Preferably, it has a hydrocarbon group, such as an alkyl or aryl group, especially a methyl or phenyl group. From the viewpoint of controlling physical properties such as refractive index, R 1 At least a portion of it can be aryl groups such as phenyl.

[0095] As another example of component (B), a linear organohydrogen polysiloxane with Si-H bonds at the end, as shown in formula (4), can be cited.

[0096] (H) （3-a） R 1 a SiO 1 / 2 ) b (R) 1 3SiO 1 / 2 ) 2-b (HR) 1 SiO2 / 2 ) e (R) 1 2SiO 2 / 2 ) d ···(4)

[0097] (where R) 1 (a, d are defined as above, b is 0, 1 or 2, and e is a number greater than or equal to 1.)

[0098] Preferably, the main part of the siloxane backbone in the organohydrogen polysiloxane is a linear backbone. While the main chain of such organohydrogen polysiloxanes is a linear backbone, it can also be a backbone with branched structures that act as substituents. Furthermore, the number of hydrogen groups (i.e., equivalent to Si-H bonds) bonded to silicon atoms in one molecule is three or more, more preferably five or more per molecule, and even more preferably eight or more. There are no particular limitations on other conditions in the organohydrogen polysiloxane, such as the organic groups other than hydrogen groups, bonding positions, degree of polymerization, or structure. In the case of linear organohydrogen polysiloxanes, if 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, tends to further improve the processability of the resulting composition, which is therefore preferred. Specific examples of usable organohydrogen polysiloxanes include units containing eight or more Si-H bonds (M... H Or D H Organohydrogen polysiloxanes with a linear backbone and a degree of polymerization ranging from 10 to 120 (units).

[0099] The amount of component (B) can be designed, using the criteria described later, to fall within an appropriate range, based on the amount of unsaturated groups present in component (A). Component (B) can be differentiated based on the position or type of crosslinking groups, the degree of polymerization of the organohydrogen polysiloxane, etc., and may consist of only one compound or a mixture of two or more compounds. Component (B) may also be a mixture of organohydrogen polysiloxanes with different degrees of polymerization.

[0100] Component (B) is a linear organohydrogen polysiloxane, with H+ at both ends. （3-a） R 1 a SiO 1 / 2 Unit or R 1 3SiO 1 / 2 The unit is closed, and the intermediate unit contains at least one HR. 1 SiO 2 / 2 Units and any number of R 1 2SiO 2 / 2Unit. At least one hydrogen atom bonded to a silicon atom is present in the intermediate unit, and the remaining at least two can be present at the end or in the intermediate unit. As shown in equation (3) above, the hydrogen atom bonded to the silicon atom is preferably present in the intermediate unit.

[0101] As component (B), it is particularly preferred that (B1-1) has both ends closed by M units (trimethylsiloxane units) and the middle unit contains only D. H The unit (methylhydrosiloxane unit) is a linear polymethylhydrosiloxane, (B1-2) with both ends closed by M units (trimethylsiloxane units), and the middle unit contains only D units (dimethylsiloxane units) and D... H A linear polymethylhydrosiloxane with a unit (methylhydrosiloxane unit) and the methylhydrosiloxane unit being 0.1 to 3.0 moles relative to 1 mole of dimethylsiloxane unit. Component (B) may be one or a combination of two or more.

[0102] Regarding the amount of component (B), it is preferable that the number of hydrogen atoms directly bonded to silicon atoms is 0.2 to 2.0 relative to one curable functional group (alkenyl group) of component (A). If the number is less than 0.2, curing may not proceed at a sufficient speed; if the number exceeds 2.0, the cured material may become too hard, which can also adversely affect the physical properties of the cured product. In other words, the amount of polyorganosiloxane containing alkenyl groups (especially vinyl groups) within the molecule can be adjusted by the molar ratio (H / Vi ratio) of the Si-H bonds in the organohydrogen polysiloxane to the vinyl groups. 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 making the H / Vi ratio 0.5 or higher, curing can be achieved at a sufficient speed, and better adhesion to various substrates can also be exhibited. Furthermore, by keeping the H / Vi ratio below 2.0, the composition can be cured in sufficient quantity, maintaining moderate hardness, heat resistance, and better adhesion.

[0103] • Ingredient (C)

[0104] The composition of the present invention comprises a curing catalyst (hereinafter, sometimes simply referred to as "component (C)") capable of catalyzing the crosslinking reaction of the above-described components (A) and (B). As the curing catalyst, a UV-active platinum hydrogenation catalyst having a cyclopentadienyl group, preferably a naphthyl group, as a ligand can be used. Its amount is 0.1 to 1000 ppm relative to component (A), calculated as platinum. If less than 0.1 ppm, the catalyst efficiency may not be sufficient to achieve adequate curing of the composition; furthermore, even if it exceeds 1000 ppm, a significant increase in curing rate cannot be expected.

[0105] A specific example of a curing catalyst is a platinum-cyclopentadienyl complex as shown in the following formula.

[0106] [(R)] x ) x (R) y ) y H 4-x-y C5]Pt(R) z 3

[0107] (where R) x It is a fused aromatic hydrocarbon group with 7 to 20 carbon atoms.

[0108] R y It is a fused aromatic hydrocarbon group with 7 to 20 carbon atoms or an aliphatic hydrocarbon group with 1 to 22 carbon atoms.

[0109] R z Each is independently an aliphatic hydrocarbon group or a trialkylsilyl group having 1 to 22 carbon atoms.

[0110] x is an integer from 1 to 3.

[0111] y is an integer from 0 to 3, and x + y is an integer from 1 to 4. When x or y is 2 or 3, each R x Or R y They can be the same or different.

[0112] As a group R x For fused aromatic hydrocarbon groups, any structure consisting of two or more fused aromatic rings is acceptable; an example is the naphthyl (C 10 H7), Figi (C) 14 H9), anthracene (C 14 H9), pyrene (C 16 H9), etc., preferably naphthyl or phenanthrene, particularly naphthyl. These groups may also be further substituted with one or more substituents such as methyl, isopropyl, tert-butyl, phenyl, etc. The present invention is based on the discovery that by using a substituent R having a fused aromatic hydrocarbon group, particularly naphthyl, as a cyclopentadienyl group. x The platinum complex does not sublimate or disappear from the composition even under reduced pressure, thus not impairing the curability of the UV-curable silicone composition.

[0113] As a group R y R z It is an aliphatic hydrocarbon group with 1 to 22 carbon atoms, preferably an alkyl group with 1 to 6 carbon atoms, and more preferably a methyl group.

[0114] As a group R zExamples include trialkylsilyl groups having 3 alkyl groups having 1 to 6 carbon atoms. The alkyl groups bonded to silicon can be of different types, with trimethylsilyl being the most preferred.

[0115] As a platinum ligand [(R x ) x (R) y ) y H 4-x-y C5] forms a substituted cyclopentadienyl group and bonds to platinum via a σ bond. That is, any one of the carbon atoms in the 5-membered ring constituting the cyclopentadienyl group forms a bond with platinum. Therefore, the substituent R on the cyclopentadienyl group... x and R y The total number is 1 to 4. For group R... x and R y The replacement 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.

[0116] 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'-phenanthyl)-cyclopentadienyl]trimethylplatinum; [1-methyl-3-(9'-phenanthyl)-cyclopentadienyl]trimethylplatinum; [1-(2'-anthrayl)-3-methyl-cyclopentadienyl]trimethylplatinum; [(2'-anthrayl)-cyclopentadienyl]trimethylplatinum; [(1'-pyrene)-cyclopentadienyl]trimethylplatinum; [1-methyl-3-(1'-pyrene)-cyclopentadienyl]trimethylplatinum. More preferred curing catalysts are [1-methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatinum or [1-methyl-3-(9'-phenanthyl)-cyclopentadienyl]trimethylplatinum. Curing catalysts other than those can be used as long as they can be represented by the above formula, and two or more curing catalysts can be used in combination.

[0117] As platinum complexes, commercially available products or platinum complexes synthesized by known methods can be used. For example, the target platinum complex can be obtained by reacting a lithium salt substituted with cyclopentadiene with a platinum(IV) complex having a leaving group such as a halogen or phosphate ester. Furthermore, for the purpose of obtaining processability and homogeneity in the composition, a solution-like substance dissolved in solvents such as toluene (aromatic hydrocarbons), heptane (hydrocarbons), ethers, ketones, or alcohols can be used. However, to suppress the amount of volatile components in the composition, it is preferable to use a small amount of solvent in which it is dissolved; more preferably, the platinum complex is used in solid form instead of as a solution.

[0118] Depending on the intended use of the UV-curable silicone composition, a reaction inhibitor can be added to suppress catalyst activity in order to obtain a longer pot life. Examples of known reaction inhibitors for platinum group metals include alkynyl alcohols such as 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, and 1-ethynyl-2-cyclohexanol, diallyl maleate, and tertiary amines such as tetramethylethylenediamine and pyridine.

[0119] • Composition

[0120] The UV-curable silicone composition of the present invention contains the above-described components (A) to (C). In particular, the present invention is a UV-curable silicone composition containing the above-described components (A) to (C), wherein the content of organic solvents volatilized under reduced pressure is 0.5% by mass or less, preferably 0.1% by mass or less, relative to the total composition. The preferred manner for components (A) to (C), which are essential components, is as described above. For components (A) and (B), the appropriate substances can be selected from commercially available and known substances 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 this case, it is preferable to design the composition so that the refractive index when the cured product is 1.56 or less.

[0121] The properties of the UV-curable silicone composition of the present invention are not particularly limited as long as the components are uniformly mixed and have a degree of fluidity suitable for application to a substrate. The viscosity of the composition can be mainly controlled by the viscosity of component (A), and from an operability point of view, a range of 0.1 to 500 Pa·s is preferred. A range of 0.1 to 50 Pa·s is more preferred. The UV-curable silicone composition of the present invention exhibits high stability, therefore, viscosity variation is small even during long-term storage, resulting in excellent processability. A composition with a viscosity of 50 Pa·s or less after one week at 80°C under light-shielding conditions is particularly preferred.

[0122] Furthermore, the UV-curable silicone composition can be a single-component composition in which all components are completely mixed, or a two-component composition in which components (B) and (C) are separately formulated. The choice between a single-component or two-component composition can be appropriately made considering factors such as workability and curing conditions, and such methods are well known to those skilled in the art.

[0123] Regarding the UV-curable silicone composition of the present invention, other known ingredients may be incorporated as long as their purpose and effect are not impaired. As additives, flame retardants, adhesive agents, heat-resistant agents, diluents, organic solvents, inorganic or organic pigments, etc., may be appropriately incorporated. Additionally, silicone resins not belonging to components (A) or (B) above may also be incorporated. 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.

[0124] <Other Resins>

[0125] The UV-curable silicone composition may further include a siloxane resin that is not one of the components (A) and (B) above. Such a resin can also be used as a diluent for adjusting viscosity. As such a siloxane resin, a siloxane resin that does not have a curable functional group or has only one curable functional group in the resin obtained by the combination of the above M, D, T, and Q units can be used, especially the siloxane with only one curable functional group shown in formula (5) below, and the siloxane without a curable functional group shown in formula (6).

[0126] R a R2Si-O-(SiR2O) n SiR3···(5)

[0127] (where R) a As defined in equation (2), R and n, R does not have a curing functional group.

[0128] R3Si-O-(SiR2O) n SiR3···(6)

[0129] (In the formula, R and n are as defined in formula (2), and R does not have a curing functional group)

[0130] By using such siloxane resins, it is possible to control the hardness of the UV-curable silicone composition during curing, control the viscosity of the composition, and broadly address the required processability and physical properties.

[0131] In a UV-curable silicone composition, for example, less than 50 parts by weight of such resin may be included relative to 100 parts by weight of component (A), specifically, 0.1 to 50 parts by weight, and more specifically, 1 to 30 parts by weight.

[0132]

[0133] The composition may further comprise a polyorganohydrosiloxane having two hydrogen atoms bonded to silicon atoms in the molecule. Such a siloxane can act as a chain extender by undergoing an addition reaction with component (A). Examples of such siloxanes, in addition to having two hydrogen atoms bonded to silicon atoms in the molecule, are as described in component (B). Such siloxanes preferably have two of the above general formulas (3) or (4) in the molecule, with the number of Si-H bonds being two. （3-a） R 1 a SiO 1 / 2 or HR 1 SiO 2 / 2 The unit shown.

[0134] The siloxane backbone in this component can be any of linear, branched, or cyclic, preferably linear. Furthermore, the siloxane in this component is more preferably characterized by each end being independently R-terminated. 5 3SiO 1 / 2 The unit is closed, and the intermediate unit contains only R. 5 2SiO 2 / 2 Unit (where R) 5 Each molecule consists independently of a hydrogen atom or a monovalent hydrocarbon group without aliphatic unsaturated bonds, with 2 R atoms per molecule. 5 A linear polyorganosiloxane (containing hydrogen atoms). The hydrogen atoms bonded to silicon atoms can be present at the ends or in the middle units, but are preferably present at the ends. Therefore, the siloxane used in this formulation is particularly preferred to have M atoms bonded to both ends. H Polymethylhydrosiloxane is a polymethylhydrosiloxane with closed units (dimethylhydrosiloxane units) and intermediate units consisting only of D units (dimethylsiloxane units).

[0135] <Adhesive-enhancing agents>

[0136] Regarding UV-curable silicone compositions, adhesive-improving agents may be further included, provided that the purpose and effects of the present invention are not impaired. Adhesive-improving agents are components that enhance the adhesion of the cured composition to substrates such as glass, metal, and plastic. Examples of adhesive-improving agents include metal alkoxides, compounds having hydrolyzable silyl groups, compounds having both hydrolyzable silyl groups and reactive organic functional groups in one molecule, compounds having a hydrogen atom bonded to a silicon atom and a divalent aromatic group in one molecule, compounds having both 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 triethoxyaluminum, tripropoxyaluminum, and tributoxyaluminum; and titanium alkoxides such as tetraethoxytitanium, tetrapropoxytitanium, tetraisopropoxytitanium, tetrabutoxytitanium, tetraisobutoxytitanium, and tetraisopropoxytitanium. Examples of adhesive agents for organic compounds include amino-containing silanes, isocyanurates, and carbazide silanes. Specific examples include tetraethoxysilanes, oligomers of tetramethoxysilanes, vinyltrimethoxysilanes, vinyltriethoxysilanes, 3-epoxypropoxypropyltrimethoxysilanes, 3-epoxypropoxypropyltriethoxysilanes, 3-epoxypropoxypropylmethyldimethoxysilanes, 3,4-epoxycyclohexylethyltrimethoxysilanes, 3-acryloyloxypropyltrimethoxysilanes, 3-methacryloyloxypropyltrimethoxysilanes, 3-acryloyloxypropylmethyldimethoxysilanes, 3-methacryloyloxypropylmethyldimethoxysilanes, and 3-methacryloyloxypropylmethyldiethoxysilanes. In particular, in terms of preventing haze increase under high temperature and high humidity conditions, formulations in which these components are less than 5 parts by mass relative to 100 parts by mass of component (A) as the base polymer are preferred.

[0137] Examples of substances that can be used as adhesive agents include the following.

[0138] (E1) has Si(OR) 3 ) n Organosilicon compounds containing radicals and epoxy groups, and / or their partial hydrolytic condensates;

[0139] (E2) has Si(OR) 3 ) n Silane compounds of alkyl and aliphatic unsaturated hydrocarbon groups, and / or their partially hydrolyzed condensates; and

[0140] (E3)Si(OR) 4 The tetraalkoxysilane compound shown in 4, and / or its partial hydrolysis condensate.

[0141] (E4) A siloxane compound having at least two hydrogen atoms bonded to silicon atoms in one molecule and having one hydrolyzable group bonded to the siloxane skeleton via a heteroatom-containing structure.

[0142] (In the above formulas, R) 3 Indicates an alkyl group or a 2-methoxyethyl group having 1 to 4 carbon atoms; R 4 This refers to alkyl groups with 1 to 3 carbon atoms; where n is an integer from 1 to 3.

[0143] (E1), (E2), (E3) and (E4) can each be used in one type or in combination of two or more types.

[0144] <<(E1)>>

[0145] (E1) is introduced into the cross-linked siloxane structure through a co-hydrolysis-condensation reaction of alkoxy groups bonded to silicon atoms and alkoxy groups bonded to silicon atoms of (E2) and / or (E3). The epoxy groups, as the adhesive part, are components that help improve the adhesion of the composition at room temperature, especially the adhesion to plastics.

[0146] From the perspective of providing good adhesion, R 3 Methyl and ethyl groups are preferred, with methyl being particularly preferred. n is preferably 2 or 3. As the epoxy-containing group, from the perspectives of ease of synthesis, non-hydrolysis, and excellent adhesive properties, aliphatic epoxy-containing groups such as 3-epoxypropoxypropyl containing an ether oxygen atom are preferred; groups containing alicyclic epoxy groups such as 2-(3,4-epoxycyclohexyl)ethyl are also preferred. Si(OR) 3 ) n There can be more than two groups in a molecule. 3 The number of groups is preferably two or more in the molecule. OR 3 The group and the epoxy group can be bonded to the same silicon atom or to different silicon atoms.

[0147] Examples of (E1) include alkoxysilanes containing 3-epoxypropoxypropyl groups, such as 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropyltriethoxysilane, and 3-epoxypropoxypropyl(methyl)dimethoxysilane; alkoxysilanes containing 2-(3,4-epoxycyclohexyl)ethyl groups, such as 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane and 2-(3,4-epoxycyclohexyl)ethyl(methyl)dimethoxysilane; partially hydrolyzed condensates of these silanes with n being 2 or more; and carbon / silicon bifunctional siloxanes formed by replacing a portion of the methyl group of a chain or cyclic methylsiloxane with trimethoxysilyloxy or 2-(trimethoxysilyl)ethyl, and the aforementioned epoxy-containing groups.

[0148] <<(E2)>>

[0149] (E2) undergoes an addition reaction with (B) during composition curing, and is incorporated into the crosslinked siloxane structure formed by the addition reactions with (A) and (B). The alkoxy groups present in the side chains act as adhesive components, contributing to improved adhesion of the composition at room temperature, particularly to metals. Furthermore, the alkoxy groups of (E2) also facilitate the incorporation 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 preferably composed of Si(OR) 3 ) n Silane compounds containing one aliphatic unsaturated hydrocarbon group and / or their partially hydrolyzed condensates.

[0150] From the perspective of providing good adhesion, R 3 Methyl and ethyl groups are preferred, with methyl being particularly preferred. n is preferably 2 or 3. The aliphatic unsaturated hydrocarbon group is preferably a monovalent group. When the aliphatic unsaturated hydrocarbon group is an alkenyl group such as vinyl, allyl, or 3-butenyl, it can be directly bonded to the silicon atom, or, as with 3-acryloyloxypropyl or 3-methacryloyloxypropyl, the unsaturated acryloyloxy group is bonded to the silicon atom via three or more carbon atoms. From the perspective of ease of synthesis and processing, vinyl, methacryloyloxypropyl, etc., are preferred as groups containing unsaturated hydrocarbon groups. Si(OR) 3 ) n There can be more than two groups in a molecule. 3 The number of groups is preferably two or more in the molecule. OR 3 The radical and the aliphatic unsaturated hydrocarbon radical can be bonded to the same silicon atom or to different silicon atoms.

[0151] Examples of (E2) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethoxy)silane, methylvinyldimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, methylallyldimethoxysilane, and alkenylalkoxysilane and / or their partial hydrolysis condensates; 3-acryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltriethoxysilane, 3-acryloyloxypropyl(methyl)dimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxypropyl(methyl)dimethoxysilane and (meth)acryloyloxypropyltrialkoxysilane and / or their partial hydrolysis condensates, etc.

[0152] <<(E3)>>

[0153] (E3) is a component that further improves the adhesion of the composition to metals at room temperature. As R 4 Examples of suitable alkyl groups include straight-chain or branched alkyl groups such as methyl, ethyl, propyl, and isopropyl. Methyl and ethyl groups are preferred due to their ease of availability, ease of processing, and significant improvement in adhesion. Additionally, (E3) may use a tetraalkoxysilane monomer. Partially hydrolyzed condensates of tetraalkoxysilane compounds are preferred due to their excellent hydrolytic properties and reduced toxicity.

[0154] <<(E4)>>

[0155] (E4) is a siloxane compound that functions as an adhesive agent, having hydrogen atoms bonded to silicon atoms and hydrolyzable groups. The hydrolyzable groups are bonded to the siloxane backbone via a heteroatom-containing structure. During composition curing, (E4) undergoes an addition reaction with component (A), being incorporated into the crosslinked siloxane structure formed by addition reactions with (A) and (B), thus contributing to the adhesive properties of the composition at room temperature. However, substances belonging to component (A) or (B) are excluded from this composition.

[0156] "A structure containing heteroatoms" is a divalent functional group containing at least one of oxygen, nitrogen, sulfur, or phosphorus. There are no particular restrictions on the structure as long as the skeleton, in which the group capable of hydrolysis is linked to the siloxane skeleton with a minimum number of atoms, contains heteroatoms. Examples of structures containing heteroatoms include those obtained by substituting the -CH2- portion of a divalent alkylene group with at least one ether group (-O-), amino group (-NR-; where R is a hydrogen atom or a monovalent hydrocarbon group), thioether group (-S-), sulfonyl group (-SO2-), phosphonyl group (-PR-), ester group (-O(C=O)-), thioester group (-S(C=O)-), etc.

[0157] In the context of this specification, "hydrolyzable group" refers to a group capable of undergoing a hydrolysis reaction, that is, a group that can be removed from the main skeleton of the compound through a hydrolysis reaction. In (E4), it is preferable that the molecule contains only one hydrolyzable group, which is bonded to the siloxane skeleton via a heteroatom-containing structure. Examples of hydrolyzable groups include -OR', -OCOR', -ON=CR'2, -NR'2, -NHR', epoxy groups, halogen atoms (in these formulas, R' represents an alkyl group with 1 to 4 substituted or unsubstituted carbon atoms), etc. -OR' (i.e., alkoxy group) is preferred for reasons such as preventing corrosion of various substrates and ensuring chemical stability of the organosilicon composition. Examples of R' include unsubstituted alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, and isobutyl; and substituted alkyl groups such as chloromethyl. Among these, alkyl groups are preferred, especially unsubstituted alkyl groups, and methyl or ethyl groups are more preferred. That is, as a hydrolyzable group, an alkoxy group such as methoxy, ethoxy, propoxy, or butoxy is preferred. The hydroxyl group is not particularly limited and can also be a hydroxyl group generated by hydrolyzing a hydrolyzable group. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine, with chlorine being preferred.

[0158] As (E4), examples can be given of organosilicon compounds having hydrogen atoms bonded to silicon atoms and structures represented by the following formulas bonded to silicon atoms.

[0159] [Chemical Formula 1]

[0160]

[0161] (In the above formulas, Q) 1 This refers to a linear or branched alkylene group in which a carbon chain with two or more carbon atoms forms between a silicon atom and an ester bond; Q 2 This indicates the formation of a linear or branched alkylene group with three or more carbon atoms between an oxygen atom and a silicon atom in this structure; R 3 (Indicates alkyl or 2-methoxyethyl groups having 1 to 4 carbon atoms)

[0162] From the perspective of ease of synthesis and processing, Q 1 Ethylene and 2-methylethylene are preferred. From the perspective of ease of synthesis and processing, Q... 2 Trimethylene is preferred. From the perspective of providing good adhesion and the easy volatility of the alcohol produced by hydrolysis, R... 3 Methyl and ethyl are preferred, with methyl being particularly preferred.

[0163] From the perspective of ease of synthesis, the hydrogen atoms in the above formula and the above structure are preferably bonded to different silicon atoms. Therefore, the basic part of (E4) preferably forms a chain-like, branched, or cyclic siloxane skeleton. The number of Si-H bonds contained in (E4) is any number of one or more, and in the case of cyclic siloxane compounds, two or three are preferred.

[0164] As an example of (E4), the reaction products of cyclic organohydrogen polysiloxanes and silane compounds having acryloyl or methacryloyl groups can be cited. Such compounds are preferred from the viewpoints of establishing a synthetic route, easily controlling the number of Si-H bonds and the number of hydrolyzable groups per molecule, and easily and uniformly controlling the overall physical properties of the composition. More specifically, the following compounds can be cited as examples of (E4).

[0165] [Chemical Formula 2]

[0166]

[0167] Other components (E4) include compounds such as [Chemical Formula 3] which have hydrogen atoms bonded to silicon atoms and reactive organic functional groups in one molecule.

[0168] [Chemical Formula 3]

[0169]

[0170] <<Other Adhesive Additives>>

[0171] Other adhesive agents besides (E1) to (E4) include aluminum alkoxides such as aluminum triethoxyaluminum, aluminum tripropoxyaluminum, and aluminum tributoxyaluminum; titanium alkoxides such as titanium tetraethoxyaluminum, titanium tetrapropoxyaluminum, titanium tetraisopropoxyaluminum, titanium tetrabutoxyaluminum, titanium tetraisobutoxyaluminum, and titanium tetraisopropoxyaluminum; zirconium acylates such as zirconium octoate, zirconium tetra(2-ethylhexanoate), and zirconium stearate; zirconium alkoxides such as n-propyl zirconate and n-butyl zirconate (but excluding zirconium chelates); and zirconium chelates such as zirconium tributoxyaluminate, zirconium dibutoxybis(ethyl acetoacetate), zirconium tetraacetylacetone, zirconium monoacetylacetone, and zirconium ethylacetoacetate, as well as other metal alkoxides.

[0172] Other adhesive agents include compounds having a hydrolyzable silyl group and a reactive organic functional group in one molecule, such as [Formula 4] and [Formula 5], and / or their partially hydrolyzed condensates (except for substances belonging to (E1) to (E4)).

[0173] [Chemical Formula 4]

[0174]

[0175] [Chemical Formula 5]

[0176]

[0177] Compounds containing hydrogen atoms bonded to silicon atoms and divalent aromatic groups in one molecule, such as [Chemical Formula 6], etc.

[0178] [Chemical Formula 6]

[0179]

[0180] (In the formula, k is an integer from 1 to 3). Bond strength can be further improved by using other adhesive agents.

[0181] In a UV-curable silicone composition, for example, less than 10 parts by weight of an adhesive agent may be included relative to 100 parts by weight of component (A), specifically, 0.01 to 10 parts by weight, and more specifically, 0.1 to 5 parts by weight. The adhesive agent may be used alone or in combination of two or more types.

[0182] <Solvent>

[0183] Regarding the UV-curable silicone composition, an organic solvent that is liquid at room temperature and pressure and evaporates under reduced pressure may also be included, to a extent that does not impair the effects of the present invention. The solvent used to dissolve the platinum complex of the aforementioned component (C) may also be used as the solvent. In this case, the UV-curable silicone composition can be used by dissolving it in a suitable solvent at a desired concentration, depending on its intended use and purpose. By including a solvent, the viscosity of the curable composition can be adjusted to improve processability; however, from the viewpoint of suppressing the content of volatile components, a small amount of solvent is preferred, and solvent-free is more preferable. That is, in the UV-curable silicone composition of the present invention, the content of the organic solvent that is liquid at room temperature and pressure and evaporates under reduced pressure is preferably 1% by mass or less, more preferably 0% by mass, relative to the total composition.

[0184] One aspect of the present invention is the aforementioned UV-curable silicone composition for bonding substrates. Therefore, according to the present invention, an adhesive comprising the aforementioned UV-curable silicone composition is provided. Preferably, the adhesive comprises an adhesive-improving agent in addition to the aforementioned components (A) to (C).

[0185] [Manufacturing method of adhesive components]

[0186] One aspect of the present invention relates to a method for manufacturing an adhesive member, comprising the step of applying the aforementioned UV-curable silicone composition to a first substrate layer, wherein the method for manufacturing the adhesive member comprises, in any order:

[0187] (i) A process of bonding a first substrate layer to a second substrate layer via a layer of a UV-curable silicone composition.

[0188] (ii) A process of depressurizing the UV-curable silicone composition applied to the first substrate layer at a pressure less than atmospheric pressure; and

[0189] (iii) A process of irradiating the UV-curable silicone composition applied to the first substrate layer with ultraviolet light.

[0190] Substrate

[0191] Regarding the substrate for which the adhesive containing the UV-curable silicone composition of the present invention is applied, there are no particular limitations on its material. As a substrate, metals such as aluminum, copper, nickel, iron, brass, and stainless steel can be used; engineering plastics such as epoxy resin, polyethylene terephthalate (PET), polybutylene terephthalate (PBT) resin, polycarbonate resin, acrylic resin, polyimide resin, phenolic resin, polyamide resin, polyphenylene sulfide (PPS) resin, and modified polyphenylene ether (PPE) resin can be used; and glass, etc. Among these, substrates selected from epoxy resin, polyester resin, polycarbonate resin, acrylic resin, polarizing plate, and glass are preferred. Furthermore, as needed, conventional treatments such as primer treatment, corona treatment, plasma treatment, and excimer laser treatment can be performed on the walls of the voids, etc., according to conventional methods. In the method of the present invention, a first substrate to which the UV-curable silicone composition is applied and a second substrate bonded to the first substrate are used, but the first and second substrates being bonded can be substrates of different materials.

[0192] Application of substrates

[0193] The adhesive comprising a UV-curable silicone composition is applied to the bonding area on the surface of a component containing a substrate at a predetermined thickness by methods such as dripping, injection, casting, extrusion from a container, rod coating, roller coating, die coating, screen printing, dipping, brushing, spraying, and dispensing. In particular, coating using a slit die, suitable for application as a uniform thin film, is used as an application method to the substrate. These methods are well known to those skilled in the art. The composition can be applied integrally and uniformly to the surface of the component, or it can be applied unevenly or partially, such as in lines, stripes, or dots. The application thickness of the composition is typically 0.01–3 mm, preferably 0.05–2 mm. In the application to the substrate, the aforementioned UV-curable silicone composition can be used as a single-component adhesive or as a 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.

[0194] The method of the present invention includes: (i) a step of bonding a first substrate layer to a second substrate layer via a layer of ultraviolet-curable silicone composition. A bonded member is obtained by bonding the first substrate to the second substrate. The bonding method is not particularly limited, and any means can be used. The ultraviolet-curable silicone composition can also be applied to the second substrate side. For articles obtained by using the ultraviolet-curable silicone composition of the present invention as an adhesive, there are no particular limitations on its shape, thickness, etc., as long as the composition has an adhesive portion with each substrate. Furthermore, the bonding step can be performed under reduced pressure or ultraviolet irradiation conditions described later.

[0195] • Pressure reduction process

[0196] The method of the present invention includes: (ii) a step of performing a decompression treatment on a UV-curable silicone composition applied to a first substrate layer under a pressure less than atmospheric pressure. Here, the object subjected to the decompression treatment can be the first substrate to which the UV-curable silicone composition has been applied before bonding to the second substrate, or it can be a bonding member to which the second substrate has been bonded. The conditions for the decompression treatment are not particularly limited as long as they are sufficient to remove gases such as air and volatile solvents contained in the UV-curable silicone composition. While the conditions for the decompression step also depend on the size of the bonding member, the pressure is less than atmospheric pressure, preferably 30 kPa or less, more preferably 10 kPa or less. The decompression treatment time is 10 seconds or more, preferably 30 seconds or more, more preferably 1 minute or more, and can generally be completed within a time of 5 minutes or less. The pressure and time conditions can be combined within a range that achieves the desired effect. Furthermore, in order to efficiently remove bubbles, etc., a heat treatment may be performed separately or simultaneously within the range relevant to the heat resistance of the substrate.

[0197] Curing process

[0198] The method of the present invention includes: (iii) a step of irradiating a UV-curable silicone composition applied to a first substrate layer with ultraviolet light. The first substrate or bonding member to which the composition of the present invention is applied can be bonded by partially curing the composition through ultraviolet irradiation. The ultraviolet irradiation dose is preferably 100 to 10000 mJ / cm². 2 More preferably, it is 300–6000 mJ / cm². 2 Further preferably, it is 500–4000 mJ / cm 2 It should be noted that the irradiation dose is a measured value of UVA. Here, UVA refers to ultraviolet light in the range of 315–400 nm. The composition exhibits good curability when irradiated with ultraviolet light of wavelengths, for example, in the range of 250–450 nm. In particular, the UV-curable silicone composition of the present invention exhibits good curability even when irradiated with lower energy ultraviolet light in the wavelength range above 365 nm. Examples of light sources that emit ultraviolet light at such wavelengths include high-pressure mercury lamps (UV-7000) and metal halide lamps (UVL-4001M3-N1) manufactured by USHIO Electric Co., Ltd.; metal halide lamps (JM-MTL 2KW) manufactured by JM Tech Co., Ltd. of South Korea; ultraviolet irradiation lamps (OSBL360) manufactured by Mitsubishi Electric Co., Ltd.; ultraviolet irradiation machines (UD-20-2) manufactured by Nippon Battery Co., Ltd.; fluorescent lamps (FL-20BLB) manufactured by Toshiba Co., Ltd.; H bulbs, H+ bulbs, V bulbs, D bulbs, Q bulbs, and M bulbs manufactured by Heraeus Co., Ltd.; and LED lamps (HLDL-155UV) manufactured by CCS Co., Ltd.

[0199] While the curing time of the composition also depends on the amount of ultraviolet radiation, it is generally less than 30 minutes. Whether the composition has cured can be qualitatively judged by visual inspection or by whether the surface is non-sticky (whether it feels sticky upon contact). Alternatively, it can be quantitatively evaluated by measuring the storage modulus G' and loss modulus G'". For example, if, under ultraviolet radiation and at 23°C, the time until the storage modulus G' and loss modulus G' become equal is less than 30 minutes, then the curing time is short, the processability is excellent, and therefore it is preferred.

[0200] The method of the present invention includes the step of applying the above-described UV-curable silicone composition to a first substrate layer, and 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 steps (i), (ii), and (iii) are performed is not particularly limited and can be performed in any order. For example, steps (i), (ii), and (iii) can be performed in the order of steps (i), (ii), and (iii), or in the order of steps (ii), (ii), and (i). These steps can be performed continuously, or two or three steps can be performed simultaneously, such as bonding under reduced pressure.

[0201] One aspect of the present invention is a component having a layer bonded from the aforementioned UV-curable silicone composition. Because the UV-curable silicone composition of the present invention uses a low-volatility platinum catalyst, the curing reaction proceeds well. As a result, articles obtained using the component of the present invention exhibit excellent durability, particularly in terms of water resistance at the bonded surfaces and sealing areas, making them suitable for use in various electronic components. Furthermore, due to its good curability, it can be used, for example, as an adhesive for bonding image display devices such as liquid crystal displays, plasma displays, and organic EL displays. It should be noted that the component of the present invention contains a non-volatile platinum catalyst in the adhesive layer containing the aforementioned UV-curable silicone composition, the amount of which can be measured. The amount of platinum in the adhesive layer also depends on the concentration of the platinum catalyst in the composition, and is approximately 0.1 ppm or more and 50 ppm or less.

[0202] Example

[0203] The compositions of the present invention are illustrated in more detail by way of the following examples, but the present invention is not limited to the manner of these examples.

[0204] The materials used in the embodiments and comparative examples are described below. Here, M, D, and D are used to describe...H The symbols for siloxane compounds have the meanings described above. Furthermore, unless otherwise specified, the proportions of each composition are expressed in parts by mass.

[0205] <Polyorganosiloxane resin: Component (A)> α,ω-divinyl polydimethylsiloxane; viscosity 3 Pa·s

[0206] <Organohydrogen polysiloxane: Ingredient (B)>MD 17 D H 23 M represents an organohydrogen polysiloxane.

[0207] <Platinum Catalyst: Composition (C)> [1-Methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatinum or [1-Methyl-3-(9'-phenanthyl)-cyclopentadienyl]trimethylplatinum

[0208] <Silane compound (D)> reacts 3-methacryloyloxypropyltrimethoxysilane with DD H The substance obtained by the addition reaction of the cyclic siloxane shown in Figure 3

[0209] [Experimental Example 1: Gel Time]

[0210] Using a viscoelasticity measuring apparatus (MCR302) (manufactured by Anton Paar Japan Co., Ltd.), the composition was ejected onto a lower parallel quartz plate at 23°C. Then, the composition was held in place with an upper parallel plate (8 mm in diameter) to a thickness of 300 μm, and irradiated for 10 seconds with an LED at an intensity of 100 mW and a wavelength of 365 nm. 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' become equal was taken as the G'G' crossover point and defined as the curing time of the composition.

[0211] [Experimental Example 2: Gel Time After Decompression]

[0212] The composition was coated to a thickness of 90 μm, and the film was placed at 1 kPa for 5 minutes. The gel time of the composition after being treated and returned to normal pressure was determined using the method of Example 1.

[0213] [Experimental Example 3: No-viscosity time]

[0214] Irradiate the surface with 200mW ultraviolet light for 20 seconds using a 405nm LED irradiation machine (CCS HLDL-120V0-NWPSC). Touch the surface every 30 seconds to confirm the curing time as the non-sticky time.

[0215] <Preparation of UV-curable silicone compositions>

[0216] [Example 1]

[0217] [1-Methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatinum was added to polyorganosiloxane resin (A) to a weight ratio of 0.05%, and the solution was heated to 95°C in an oven and stirred to obtain a platinum catalyst solution. Polyorganosiloxane resin (A), organohydrogen polysiloxane (B), platinum catalyst solution, and silane compound (D) were mixed in the proportions shown in the table to obtain composition 1.

[0218] [Example 2]

[0219] Except for replacing the platinum catalyst with an equivalent amount of [1-methyl-3-(9'-phenanthyl)-cyclopentadienyl]trimethylplatinum solution (calculated by converting platinum elements), the same procedure as in Example 1 was followed to prepare a UV-curable organosilicon composition.

[0220] [Comparative Example 1]

[0221] Except for changing the platinum catalyst to an equivalent amount of methylcyclopentadienyltrimethylplatinum ([MeCpPtMe3]), the same procedure as in Example 1 was followed to prepare a UV-curable organosilicon composition.

[0222] [Comparative Example 2]

[0223] In addition to changing the platinum catalyst to pentamethylcyclopentadienyltrimethylplatinum ([Cp]), which is equivalent in amount to platinum element (in terms of the amount of platinum element), * Except for PtMe3), a UV-curable silicone composition was prepared by operating in the same manner as in Example 1.

[0224] [Comparative Example 3]

[0225] An attempt was made to prepare a platinum solution using the same method as in Example 1, but platinum diacetylacetonate ([Pt(acac)2]) did not show any solubility. Therefore, a 0.05% solution was prepared using 2-2-methoxyethoxyethanol to form a platinum catalyst solution. Except for changing the platinum catalyst to an equivalent amount of platinum diacetylacetonate ([Pt(acac)2]), the same procedure as in Example 1 was followed to prepare a UV-curable silicone composition. The results of Test Examples 1-3 in the various Examples and Comparative Examples are shown in Table 1.

[0226] [Table 1]

[0227]

[0228] As shown in Table 1, the UV-curable silicone compositions of the present invention using a specific platinum catalyst exhibit short gelation times and excellent curing properties. Furthermore, it was found that their curing properties are not impaired even after depressurization, making them suitable for manufacturing components where depressurization is included during bonding. Additionally, the UV-curable silicone compositions using this specific platinum catalyst also demonstrate excellent curing properties when irradiated with long-wavelength ultraviolet light. On the other hand, for compositions using other platinum catalysts, although curing occurs, the time until gelation is slightly longer, and this trend is further enhanced by depressurization.

Claims

1. A method for manufacturing an adhesive component, comprising the step of applying a UV-curable silicone composition to a first substrate layer, the UV-curable silicone composition comprising: (A) An organopolysiloxane containing at least two unsaturated groups bonded to silicon atoms in one molecule; (B) An organohydrogen polysiloxane having at least three hydrogen atoms bonded to silicon atoms in one molecule; and (C) A UV-active platinum hydrogen silane catalyst with a cyclopentadienyl group bonded to a fused aromatic hydrocarbon group as a ligand. Furthermore, the method for manufacturing the adhesive component includes, in any order: (i) A process of bonding a first substrate layer to a second substrate layer via a layer of a UV-curable silicone composition. (ii) A process of depressurizing the UV-curable silicone composition applied to the first substrate layer at a pressure less than atmospheric pressure; as well as (iii) A process of irradiating the UV-curable silicone composition applied to the first substrate layer with ultraviolet light.

2. The method according to claim 1, wherein, The procedures (i), (ii), and (iii) shall be performed in the order of procedure (ii), procedure (iii), and procedure (i).

3. The method according to claim 1, wherein, The procedures (i), (ii), and (iii) shall be performed in the order of procedure (iii), procedure (ii), and procedure (i).

4. The method according to claim 1, wherein, The process (iii) is the process of irradiating with ultraviolet light with a wavelength of 365 nm or higher.

5. The method according to claim 1, wherein, The component (A) is a linear organopolysiloxane.

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

7. The method according to claim 1, wherein, The molar ratio of the hydrogen directly bonded to silicon in (B) to the unsaturated groups in (A), i.e., the H / Vi ratio, is in the range of 0.2 to 2.

0.

8. The method according to claim 1, wherein, The ultraviolet-active hydrogenated silane platinum catalyst of (C) is [1-methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatinum or [1-methyl-3-(9'-phenanthyl)-cyclopentadienyl]trimethylplatinum.

9. The method according to any one of claims 1 to 8, wherein, The first or second substrate is selected from epoxy resin, polyester resin, polycarbonate resin, acrylic resin, polarizing plate, and glass.

10. A UV-curable silicone composition for bonding substrates, comprising: (A) An organopolysiloxane containing at least two unsaturated groups bonded to silicon atoms in one molecule; (B) An organohydrogen polysiloxane having at least three hydrogen atoms bonded to silicon atoms in one molecule; (C) A UV-active platinum hydrogen silane catalyst with a cyclopentadienyl group bonded to a fused aromatic hydrocarbon group as a ligand.

11. The method according to claim 10, wherein, The ultraviolet-active hydrogenated silane platinum catalyst of (C) is [1-methyl-3-(2'-naphthyl)-cyclopentadienyl]trimethylplatinum or [1-methyl-3-(9'-phenanthyl)-cyclopentadienyl]trimethylplatinum.

12. A component having a layer bonded using the UV-curable silicone composition of claim 10 or 11.

13. A UV-curable silicone composition comprising: (A) An organopolysiloxane containing at least two unsaturated groups bonded to silicon atoms in one molecule; (B) An organohydrogen polysiloxane having at least three hydrogen atoms bonded to silicon atoms in one molecule; (C) A UV-active platinum hydrogen silane catalyst with a cyclopentadienyl group bonded to a fused aromatic hydrocarbon group as a ligand. The content of organic solvents that are liquid at room temperature and pressure and evaporate under reduced pressure relative to the composition as a whole is 0 by mass.

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