Binary room temperature condensation curable organopolysiloxane composition

Abstract

A binary room temperature condensation curable organopolysiloxane composition is provided, which imparts a cured product with high light transmittance, low hardness and flexibility, and has fast curing properties and deep curing properties. The binary room temperature condensation curable organopolysiloxane composition is composed of a first component and a second component, wherein the first component contains (A) component: a diorganopolysiloxane having hydroxyl groups at both ends of the molecular chain and (B) component: a β-ketoester compound; the second component contains (C) component: a hydrolyzable organosilane compound having three or more organic oxygen groups bonded to silicon atoms in one molecule and / or its partial hydrolysis condensate, (D) component: an amino-containing hydrolyzable organosilane compound and / or its partial hydrolysis condensate other than component (C) and (E) component: a curing catalyst.

Description

Technical Field

[0001] The present invention relates to a two-component room temperature condensation-curable organopolysiloxane composition which can be exposed to a moisture-containing atmosphere (air) at room temperature (23°C ± 15°C) to undergo condensation curing (crosslinking), thereby providing a silicone rubber cured product having low hardness, high elongation, excellent light transmittance and flexibility, and having good rapid curing properties and deep curing properties. Background Art

[0002] Room temperature curable (RTV) silicone rubber compositions (i.e., condensation curing type room temperature rapid curing organopolysiloxane compositions) that undergo crosslinking by condensation curing reaction with moisture in the atmosphere are used in various fields such as sealing materials for building materials and adhesives in the electrical and electronic fields because they are easy to handle and have excellent weather resistance and electrical properties. Most of these RTV silicone rubbers are designed using organopolysiloxanes having silanol groups at the ends as raw materials.

[0003] Condensation-curing organopolysiloxane compositions that are quick-curing at room temperature are known to be either one-component types that reduce the amount of crosslinking agent to the limit and increase the crosslinking speed by hydrolysis, or two-component types that package the crosslinking agent and the curing agent separately. However, the one-component type composition has a quick curing speed only on the surface, and it takes a certain amount of time to cure deep inside, so it is difficult to call it quick curing.

[0004] In the two-component type of the composition, although the deep curing property is relatively excellent, there are disadvantages that the operation is cumbersome when the mixing ratio of the two components is not 1:1, and it is difficult to be suitable for automatic mixers. Furthermore, in order to fully cure it to the depth, it is necessary to strictly control the amount of crosslinking agent and curing agent added or add water as a deep curing agent. On the other hand, in the addition-curing type organopolysiloxane composition, although its operability is excellent when the mixing ratio of the two components is 1:1, it usually requires heating to cure. In addition, there is a disadvantage that the composition is limited in use in an environment where the effect of the curing catalyst is hindered.

[0005] In order to solve these problems, Japanese Patent Application Laid-Open No. 2002-338811 (Patent Document 1) discloses a method of using water generated by a neutralization reaction of a carboxylic acid generated by hydrolyzing a hydrolyzable silane having at least two acyloxy groups in the molecule or a partial hydrolyzate thereof with an inorganic filler as a deep curing agent. However, since the room temperature fast curing organopolysiloxane composition that generates carboxylic acid has the problem of corrosive metals, its application range is very narrow.

[0006] In addition, Japanese Patent Publication No. 2002-12767 (Patent Document 2) discloses a method of using a composition as a deep curing agent by directly supplying water to the composition by mixing with water-containing wet silica. However, if water is directly supplied, it is difficult to control the speed of the curing reaction, and it is even more difficult to ensure the operability of the composition.

[0007] In addition, the production of water in the composition system is effective in promoting rapid curing and deep curing of the composition. Japanese Patent No. 2811134 (Patent Document 3) discloses a method of using water produced as a deep curing agent by a ketimine reaction between an organic compound having at least one C=O group in one molecule and an organic compound having at least one NH2 group in one molecule. Japanese Patent No. 2841155 (Patent Document 4) discloses a method of using water produced as a deep curing agent by a ketone compound produced by alkenyloxysilane and a primary amine compound. However, although rapid curing can be achieved in any of the above methods, the composition lacks transparency due to the filler, and the hardness of the cured product is high, making it difficult to be widely and permanently used in the optical field.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1 Japanese Patent Application Publication No. 2002-338811

[0011] Patent Document 2: Japanese Patent Application Publication No. 2002-12767

[0012] Patent Document 3: Japanese Patent No. 2811134

[0013] Patent Document 4: Japanese Patent No. 2841155 Summary of the invention

[0014] Problem that the invention aims to solve

[0015] Therefore, an object of the present invention is to provide a binary room temperature condensation curable organopolysiloxane composition. The composition utilizes water generated in the system by a β-ketoester compound having a C=O group and an amino group-containing hydrolyzable organosilane compound and / or a partially hydrolyzed condensate thereof to provide a cured product having high light transmittance, low hardness and flexibility, and has fast curing properties and deep curing properties.

[0016] Solutions for solving problems

[0017] To achieve the above-mentioned purpose, the inventors have compiled the results of careful research and developed the following binary room temperature condensation-curable organopolysiloxane composition, a method for curing the composition, and products bonded, coated or packaged with the cured product of the composition, thereby completing the present invention.

[0018] Therefore, the present invention provides the following binary room temperature condensation-curable organopolysiloxane composition, a method for curing the composition, and products bonded, coated or packaged with the cured product of the composition.

[0019] [1] A binary room temperature condensation curable organopolysiloxane composition, comprising a first component and a second component, wherein

[0020] The first component contains

[0021] Component (A): 100 parts by mass of a diorganopolysiloxane having both ends of the molecular chain blocked with hydroxyl groups;

[0022] (B) component: 0.01 to 2 parts by mass of a β-keto acid ester compound based on 100 parts by mass of (A) component,

[0023] The second component contains

[0024] (C) component: 0.1 to 15 parts by mass of a hydrolyzable organosilane compound having three or more organooxy groups bonded to silicon atoms in one molecule and / or a partially hydrolyzed condensate thereof, based on 100 parts by mass of (A) component;

[0025] (D) component: 0.1 to 5 parts by mass of an amino group-containing hydrolyzable organosilane compound other than component (C) and / or a partially hydrolyzed condensate thereof, based on 100 parts by mass of component (A);

[0026] (E) Component: 0.001 to 5 parts by mass of a curing catalyst based on 100 parts by mass of (A) component.

[0027] [2] The binary room temperature condensation-curable organopolysiloxane composition according to [1], which does not contain an inorganic filler.

[0028] [3] The binary room temperature condensation-curable organopolysiloxane composition according to [1] or [2], which is used for optics.

[0029] [4] The binary room temperature condensation-curable organopolysiloxane composition according to any one of [1] to [3],

[0030] The present invention can provide a silicone rubber cured product, wherein the light transmittance of the cured product having a thickness of 2.5 mm after being cured for 3 days under the conditions of 23° C. / 50% RH in the wavelength region of 400 to 800 nm is 80% or more.

[0031] [5] The binary room temperature condensation-curable organopolysiloxane composition according to any one of [1] to [4], wherein

[0032] The amount of the amine groups in the component (D) is 1 to 5 molar equivalents to the carbonyl groups in the β-ketoester compound of the component (B).

[0033] [6] The binary room temperature condensation-curable organopolysiloxane composition according to any one of [1] to [5], wherein the ratio of the first component to the second component is 50:50 to 90:10 by mass.

[0034] [7] a product,

[0035] The bonding, coating or sealing is performed using the cured product of the binary room temperature condensation-curable organopolysiloxane composition described in any one of [1] to [6].

[0036] [8] A method for curing the binary room temperature condensation-curable organopolysiloxane composition according to any one of [1] to [6],

[0037] The method comprises the steps of applying the first component containing the component (A) and the component (B) on the surface of a first substrate, applying the second component containing the component (C), the component (D) and the component (E) on the surface of a second substrate, placing the substrates facing each other and in contact with each other in such a manner that the first component and the second component are in contact with each other, and then laminating and curing the first component and the second component.

[0038] Effects of the Invention

[0039] The two-component room temperature condensation-curable organopolysiloxane composition having the fast curing property and deep curing property of the present invention can provide a cured product having high light transmittance, low hardness and flexibility, and can be used for optical purposes for the first time, widely and permanently, for example, as an encapsulation resin for bendable LEDs used in street lamps, etc. DETAILED DESCRIPTION

[0040] Hereinafter, the present invention will be described in detail.

[0041] [(A) ingredient]

[0042] The diorganopolysiloxane in which both ends of the molecular chain of component (A) are blocked with hydroxyl groups (silanol groups) is the main component (base polymer) of the binary room temperature condensation-curable organopolysiloxane composition of the present invention, and is represented by the following general formula (1) as a representative one.

[0043] HO-(R 1 2SiO) n -H (1)

[0044] (In general formula (1), R 1 are each independently an unsubstituted or substituted monovalent hydrocarbon group, and n is an integer greater than 10.)

[0045] As R 1 , for example, an alkyl group having 1 to 20 carbon atoms, preferably 1 to 8 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, preferably 2 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms, preferably 6 to 12 carbon atoms, and a group in which a part or all of the hydrogen atoms of these hydrocarbon groups are substituted by halogen atoms such as fluorine. Examples of the alkyl group include methyl, ethyl, propyl, and cyclohexyl. Examples of the alkenyl group include vinyl and allyl. Examples of the aryl group include phenyl and tolyl. Examples of the halogen atom substituent include 3,3,3-trifluoropropyl. Among these, methyl, vinyl, and phenyl are preferred, and methyl is particularly preferred.

[0046] Represents the diorganosiloxane unit (R 1 2SiO) is an integer greater than 10, but may generally be an integer of about 10 to 2000, preferably an integer of about 50 to 1200, and more preferably an integer of about 100 to 1000. It should be noted that the degree of polymerization (or molecular weight) in the present invention can be obtained, for example, as a number average degree of polymerization (or number average molecular weight) calculated in terms of polystyrene by gel permeation chromatography (GPC) analysis using toluene or the like as a developing solvent.

[0047] The viscosity of the diorganopolysiloxane at 25° C. is preferably 10 to 1,000,000 mPa·s, more preferably 100 to 100,000 mPa·s, and particularly preferably 300 to 50,000 mPa·s. If the viscosity of the diorganopolysiloxane is too low, the hardness of the cured product may increase, and the desired properties may not be obtained; on the contrary, if the viscosity of the diorganopolysiloxane is too high, the viscosity of the composition may increase, and the operability may decrease. Here, the viscosity can be measured by a rotational viscometer (for example, BL type, BH type, BS type, cone and plate type, and rheometer, etc.).

[0048] Preferred specific examples of the component (A) include the following compounds.

[0049] [Chemical formula 1]

[0050] HO-(Me2SiO) n -H

[0051] HO-(Me2SiO) n1 -(PhMeSiO) n2 -H

[0052] HO-(Me2SiO) n1 -(Ph2SiO) n2 -H

[0053] HO-[(CF3C2H4)(Me)SiO] n -H

[0054] HO-(Me2SiO) n1 -[(CF3C2H4)(Me)SiO] n2 -H

[0055] (In the general formula, n is an integer greater than or equal to 10, n1 and n2 are integers greater than or equal to 1 that satisfy n1+n2=n, Me represents a methyl group, and Ph represents a phenyl group.)

[0056] In the composition of the present invention, the component (A) is contained in an amount of preferably 50 to 95% by mass, more preferably 60 to 93% by mass, and even more preferably 70 to 90% by mass.

[0057] [(B) ingredient]

[0058] The β-ketoester compound of the component (B) reacts with the amino group-containing hydrolyzable organosilane and / or its partially hydrolyzed condensate of the component (D) described later in the system (composition) to generate water (ketimine reaction), thereby acting as a fast curing agent and a deep curing agent that impart fast curing properties and deep curing properties to the composition of the present invention. Examples thereof include compounds represented by the following general formula (2).

[0059] [Chemical formula 2]

[0060]

[0061] (In general formula (2), R 2 and R 3 Each is independently an unsubstituted or substituted monovalent hydrocarbon group.)

[0062] As R 2 and R 3, for example, an alkyl group having 1 to 20 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, preferably 2 to 8 carbon atoms, and more preferably 2 to 4 carbon atoms, an aryl group having 6 to 20 carbon atoms, preferably 6 to 12 carbon atoms, and more preferably 6 to 8 carbon atoms, and groups in which a part or all of the hydrogen atoms of these hydrocarbon groups are substituted with halogen atoms such as fluorine. Examples of the alkyl group include methyl, ethyl, propyl, and cyclohexyl. Examples of the alkenyl group include vinyl and allyl. Examples of the aryl group include phenyl and tolyl. Examples of the halogen atom substituent include 3,3,3-trifluoropropyl. As R 3 , from the viewpoint of reactivity with the component (D), it is preferably a methyl group, an ethyl group, an n-propyl group, or a vinyl group, and particularly preferably a methyl group and an ethyl group. Specific examples of the component (B) include methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, isopropyl acetoacetate, butyl acetoacetate, isobutyl acetoacetate, methyl propionylacetate, and ethyl propionylacetate. Among them, ethyl acetoacetate is preferred.

[0063] The amount of component (B) is in the range of 0.01 to 2 parts by mass, preferably in the range of 0.05 to 2 parts by mass, and particularly preferably in the range of 0.1 to 1 part by mass, relative to 100 parts by mass of component (A). If the amount of component (B) is less than 0.01 parts by mass, the curability is deteriorated, and it is difficult to obtain the desired room temperature condensation curable organopolysiloxane composition. In addition, if the amount of component (B) exceeds 2 parts by mass, not only the desired physical properties cannot be obtained, but also bleeding from the composition may occur, which is more disadvantageous in terms of cost.

[0064] [(C) ingredient]

[0065] The hydrolyzable organosilane compound and / or its partially hydrolyzed condensate of the component (C) is, for example, a hydrolyzable organosilane compound and / or its partially hydrolyzed condensate having three or more (usually three or four) organic oxygen groups bonded to silicon atoms in one molecule represented by the following general formula (3), and serves as a curing agent (crosslinking agent) for the composition of the present invention. It should be noted that the "partially hydrolyzed condensate" in the present invention means an (organo)siloxane oligomer having at least two, preferably three, residual hydrolyzable groups in a molecule generated by partial hydrolysis and condensation of the (organo)silane compound.

[0066] R 4 x -Si(OR 5 ) 4-x (3)

[0067] (In general formula (3), R4 is an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, R 5 R 4 OR 5 The residue of a ketoximine group having 3 to 10 carbon atoms, wherein x is 0 or 1. )

[0068] As R 4 , for example, alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, and tert-butyl; cyclic alkyl groups such as cyclohexyl; alkenyl groups such as vinyl and allyl; and aryl groups such as phenyl and tolyl. 5 , in addition to the R 4 In addition to the unsubstituted monovalent hydrocarbon groups exemplified above, -OR 5 The residues of ketoxime groups such as dimethyl ketoxime group, methyl ethyl ketoxime group, methyl isobutyl ketoxime group, etc. are formed.

[0069] Among these, as R 4 , preferably methyl, ethyl and vinyl, particularly preferably methyl and ethyl. 5 , which are independently preferably methyl, ethyl and -OR 5 The residues of dimethyl ketoxime and methyl ethyl ketoxime are formed. 4 , R 5 They may be the same or different. x is an integer of 0 or 1. Specific examples of the component (C) include alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, methyl silicate, ethyl silicate, tetra-n-propoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, ethyltrimethoxysilane and ethyltriethoxysilane; methyltri(dimethylketoxime)silane, methyltri(methylethylketoxime)silane, ethyltri(methylethylketoxime)silane, methyltri(methyl) Ketoximate silanes such as tri(methylisobutylketoxime)silane, vinyltri(methylethylketoxime)silane and phenyltri(methylethylketoxime)silane; silanes containing isopropenyloxy groups such as methyltriisopropenyloxysilane, ethyltriisopropenyloxysilane, vinyltriisopropenyloxysilane and phenyltriisopropenyloxysilane; acetoxysilanes such as methyltriacetoxysilane, ethyltriacetoxysilane and vinyltriacetoxysilane, and partial hydrolysis condensates (siloxane oligomers) of these silanes, etc. Among them, methyltrimethoxysilane, tetraethoxysilane and tetra-n-propoxysilane are preferred.

[0070] It should be noted that the hydrolyzable organosilane compound and / or its partial hydrolysis condensate as component (C) is clearly different from the amino group-containing hydrolyzable organosilane compound and / or its partial hydrolysis condensate as component (D) described later in that it does not contain a monovalent hydrocarbon group substituted with a functional group containing a hetero atom such as an oxygen atom, a nitrogen atom, a sulfur atom, etc. in the molecule, except for the hydrolyzable group bonded to the silicon atom.

[0071] The amount of component (C) is in the range of 0.1 to 15 parts by mass, preferably in the range of 0.1 to 12 parts by mass, and particularly preferably in the range of 1 to 10 parts by mass relative to 100 parts by mass of component (A). If the amount of component (C) is less than 0.1 parts by mass, it is difficult to obtain a room temperature condensation curable organopolysiloxane composition that imparts a silicone rubber cured product with rubber elasticity for the desired purpose. In addition, if the amount of component (C) exceeds 15 parts by mass, the mechanical properties of the obtained cured product (silicone rubber) are easily reduced, and there is also the possibility that the curing speed of the composition is also slowed down.

[0072] [(D) ingredient]

[0073] The amino group-containing hydrolyzable organosilane compound and / or its partially hydrolyzed condensate as component (D) reacts (ketimine reaction) with the β-ketoester compound as component (B) as described above in the system (in the composition) to generate water, thereby functioning as a fast curing agent and a deep curing agent that impart fast curing properties and deep curing properties to the composition of the present invention.

[0074] As the amino group-containing hydrolyzable organosilane compound of component (D), known compounds can be suitably used, and specifically, examples thereof include γ-aminopropyl trimethoxysilane, γ-aminopropyl triethoxysilane, 3-(2-aminoethylamino)propyl trimethoxysilane, 3-(2-aminoethylamino)propyl triethoxysilane, 3-(2-aminoethylamino)propyl triethoxysilane, 3-(2-aminoethylamino)propyl (methyl) dimethoxysilane, 3-(2-aminoethylamino)propyl (methyl) diethoxysilane, etc. Among them, aminoalkyl-containing alkoxysilanes such as γ-aminopropyl triethoxysilane and 3-(2-aminoethylamino)propyl trimethoxysilane are particularly preferred.

[0075] Relative to 100 parts by mass of component (A), component (D) is mixed with 0.1 to 5 parts by mass, and particularly preferably with 1 to 5 parts by mass. If the mixing amount of component (D) is less than 0.1 parts by mass, the desired curability cannot be obtained. In addition, if the mixing amount of component (D) exceeds 5 parts by mass, the mechanical properties of the obtained cured product may be easily reduced, and it is also disadvantageous in terms of cost.

[0076] The amount of the amine groups in the component (D) is preferably within a range of 1 to 5 molar equivalents relative to the carbonyl groups in the β-ketoester compound of the component (B) described above.

[0077] [(E) ingredient]

[0078] The curing catalyst of component (E) may be used alone or as a mixture of two or more. Examples of the curing catalyst of component (E) include organic carboxylates or alcoholates of at least one metal selected from tin, titanium, zirconium, iron, antimony, bismuth and manganese; organic titanates and organic titanium chelates. More specifically, examples include dibutyltin dilaurate, dibutyltin dioctoate, dioctyltin dilaurate, dimethyltin dineodecanoate, dioctyltin dineodecanoate, dialkyltin diolates such as dibutyltin dimethanol and dibutyltin diethanol, maleic ester dibutyltin, stannous octoate and other tin compounds; titanium compounds such as tetrabutyl titanate, diisopropoxybis(acetylacetonate)titanium, diisopropoxybis(ethyl acetoacetate)titanium; amine compounds such as dibutylamine and laurylamine and their salts; guanidine compounds such as tetramethylguanidine and tetramethylguanidinopropyltrimethoxysilane and their salts. Since the composition of the present invention has excellent curing properties such as rapid curing and deep curing, it is preferred to add a tin compound, and among them, dialkyltin dialkoxide and dialkyltin dicarboxylate are preferably added. The amount added is 0.001 to 5 parts by mass, preferably 0.01 to 1.5 parts by mass, and particularly preferably 0.01 to 1 part by mass, relative to 100 parts by mass of component (A).

[0079] If the amount of component (E) is less than 0.001 parts by mass, the composition cannot obtain sufficient curability. In addition, if the amount of component (E) exceeds 5 parts by mass, it may cause problems such as price disadvantage and reduced curing speed.

[0080] [Other ingredients]

[0081] In addition, in the present invention, other components (optional components) other than the above components can be appropriately matched as needed. As other components (optional components), known additives can be added as long as they do not damage the purpose of the present invention. For example, polyether as a wetting agent (dispersant) or a thixotropic modifier, non-reactive dimethyl silicone oil as a plasticizer, isoparaffin as a solvent, trimethylsiloxy unit [(CH3)3SiO 1 / 2 unit] (M unit) and SiO 4 / 2 Three-dimensional network organopolysiloxane resin composed of units (Q units), etc.

[0082] Furthermore, as required, colorants such as fluorescent whitening agents, fungicides, antibacterial agents, non-reactive phenyl silicone oil as oil oozing, solvents such as toluene, xylene, solvent volatile oil, cyclohexane, methylcyclohexane, and low-boiling point isoparaffin, etc., may also be added. These optional components may be added to any one of the first component and / or the second component.

[0083] It should be noted that, from the viewpoint of maintaining light transmittance and low hardness, high elongation, flexibility and other properties of the cured product, the binary room temperature condensation-curable organopolysiloxane composition of the present invention is preferably a so-called non-filler composition that does not contain silica fine powder, metal oxide particles such as titanium oxide, metal carbonate particles such as calcium carbonate fine powder, inorganic fillers (inorganic fillers) such as carbon black in the composition.

[0084] <Method for producing composition>

[0085] The binary room temperature condensation curable organopolysiloxane composition of the present invention is firstly prepared by mixing the above-mentioned various components to be formulated in the first component and the second component and other components as required in accordance with a conventional method until they are uniform, and then the first component and the second component are separately manufactured, and the first component and the second component are mixed when used. It is preferred that the first component and the second component are stored in an atmosphere avoiding moisture. When curing the composition of the present invention, these first component and the second component are mixed in an appropriate mixing ratio until they are uniform, and by placing the mixture in an atmosphere (atmosphere) at room temperature (23°C ± 15°C) and containing moisture, usually exposing it for 10 minutes to 5 days, it can be completely cured to the depth of the composition. Therefore, the composition of the present invention is excellent in rapid curing and deep curing.

[0086] In addition, as an example of a method for curing a binary room temperature condensation-curable organopolysiloxane composition when it is applied to various substrates as an adhesive, coating agent, or encapsulant and cured, for example, a method may be used in which a first component containing components (A) and (B) is applied to the surface of a first substrate, and a second component containing components (C), (D), and (E) is applied to the surface of a second substrate, and the substrates are brought toward and in contact with each other so that the first component and the second component are in contact, and the first component and the second component are bonded together and cured.

[0087] The binary room temperature condensation curable organopolysiloxane composition of the present invention can provide a silicone rubber cured product having excellent light transmittance, low hardness, high elongation, and excellent flexibility. The silicone rubber cured product obtained from the binary room temperature condensation curable organopolysiloxane composition of the present invention has a light transmittance of 80% or more in the wavelength region of 400 to 800 nm at a thickness of 2.5 mm. In addition, the silicone rubber cured product obtained from the binary room temperature condensation curable organopolysiloxane composition of the present invention has flexibility. For example, even if a substrate having a 3 mm thick silicone rubber cured product layer on the outer surface (for example, a snake-shaped LED substrate) is bent inward by 180° together with the silicone rubber cured product layer, the silicone rubber cured product layer on the outer surface will not crack.

[0088] The silicone rubber cured product obtained by curing the composition of the present invention has high light transmittance, low hardness and flexibility, and is used for the first time in a wide range of optical applications. In particular, it is useful as a bendable LED encapsulation resin for street lamps, etc.

[0089] [Example]

[0090] Hereinafter, examples and comparative examples are shown to specifically illustrate the present invention, but the present invention is not limited to the following examples. The viscosity is a value measured at 25° C. using a rotational viscometer.

[0091] Modulation of the first component A

[0092] Under reduced pressure, 60 parts by mass of dimethylpolysiloxane (in the above general formula (1), R 1 methyl group, n is equivalent to about 615) and 20 parts by mass of dimethyl polysiloxane having a viscosity of 1500 mPa·s at 25°C and having both ends of the molecular chain capped with hydroxyl groups (silanol groups) (in the above general formula (1), R 1 is methyl, n is equivalent to about 305) and 0.2 parts by mass of ethyl acetoacetate for 60 minutes to obtain the first component A.

[0093] Modulation of the first group B

[0094] Under reduced pressure, 60 parts by mass of dimethylpolysiloxane (in the above general formula (1), R 1methyl group, n is equivalent to about 615) and 20 parts by mass of dimethyl polysiloxane having a viscosity of 1500 mPa·s at 25°C and having both ends of the molecular chain capped with hydroxyl groups (silanol groups) (in the above general formula (1), R 1 is methyl, n is equivalent to about 305) and 0.3 parts by mass of ethyl acetoacetate for 60 minutes to obtain the first component B.

[0095] Preparation of the second component A

[0096] Under normal pressure (1 atmosphere), 20 parts by mass of dimethylpolysiloxane (non-reactive dimethyl silicone oil) with a viscosity of 100 mPa·s at 25° C. and end-capped molecular chains with trimethylsiloxy groups, 3 parts by mass of tetraethoxysilane, 3 parts by mass of γ-aminopropyltriethoxysilane and 0.03 parts by mass of dimethyltin dineodecanoate were mixed for 20 minutes to obtain a second component A.

[0097] Modulation of the second group B

[0098] Under normal pressure (1 atmosphere), 20 parts by mass of dimethylpolysiloxane (non-reactive dimethyl silicone oil) with a viscosity of 100 mPa·s at 25° C. and end-capped molecular chains with trimethylsiloxy groups, 4 parts by mass of tetraethoxysilane, 3 parts by mass of γ-aminopropyltriethoxysilane, and 0.03 parts by mass of dimethyltin dineodecanoate were mixed for 20 minutes to obtain a second component B.

[0099] [Example 1]

[0100] The first component A and the second component A were mixed at a mixing ratio of 4:1 (mass) for 5 minutes, and after obtaining the composition 1, the composition 1 was cured for 3 days under the conditions of 23°C / 50%RH in a manner to form a thickness of 2.5 mm, thereby obtaining a cured product of the composition 1.

[0101] [Example 2]

[0102] The first component B and the second component A were mixed at a mixing ratio of 4:1 (mass) for 5 minutes, and after obtaining the composition 2, the composition 2 was cured for 3 days under the conditions of 23°C / 50%RH in a manner to form a thickness of 2.5 mm, thereby obtaining a cured product of the composition 2.

[0103] [Example 3]

[0104] The first component A and the second component B were mixed at a mixing ratio of 4:1 (mass) for 5 minutes, and after obtaining the composition 3, the composition 3 was cured for 3 days under the conditions of 23°C / 50%RH in a manner to form a thickness of 2.5 mm, thereby obtaining a cured product of the composition 3.

[0105] [Example 4]

[0106] The first component B and the second component B were mixed at a mixing ratio of 4:1 (mass) for 5 minutes, and after obtaining composition 4, the composition 4 was cured for 3 days under conditions of 23°C / 50%RH in a manner to have a thickness of 2.5 mm, thereby obtaining a cured product of composition 4.

[0107] [Comparative Example 1]

[0108] Although an attempt was made to use the first component A without adding ethyl acetoacetate as the first component, and to mix the first component and the second component A at a mixing ratio of 4:1 (by mass) for 5 minutes, and after obtaining the composition 5, the composition 5 was cured for 3 days under the conditions of 23°C / 50% RH in a manner to have a thickness of 2.5 mm, the composition 5 was not sufficiently cured.

[0109] [Comparative Example 2]

[0110] Although an attempt was made to use the second component A without adding γ-aminopropyltriethoxysilane as the second component, and the first component A and the second component were mixed at a mixing ratio of 4:1 (mass) for 5 minutes, and after obtaining the composition 6, the composition 6 was cured for 3 days under the conditions of 23°C / 50%RH in a manner to have a thickness of 2.5 mm, the composition 6 was not fully cured.

[0111] Evaluation items

[0112] i) Curing

[0113] Compositions 1 to 6 in which the first component and the second component were mixed at a mixing ratio of 4:1 (mass) were placed in 200 mL polypropylene containers, and the time required for the composition 1 to 6 to completely stop flowing (i.e., curing time) was measured under 23°C / 50%RH conditions. The specific measurement method is described below.

[0114] The polypropylene containers containing the compositions 1 to 6 were tilted at 90 degrees, and the time required for the composition to stop flowing was measured.

[0115] ii) Rubber properties

[0116] According to JIS K6249 standard, the hardness (Durometer.A), elongation at break (%), tensile strength (MPa) and density (g / cm 3 ) determination.

[0117] iii) Light transmittance

[0118] The light transmittance (%) of the cured products of the above compositions 1 to 6 at 400 nm, 500 nm and 800 nm was measured using a spectrophotometer U-3310 manufactured by Hitachi, Ltd.

[0119] iv) Bending test

[0120] The above compositions 1 to 6 were respectively packaged on a snake-shaped LED substrate with a thickness of 3 mm and cured for 3 days under the environmental conditions of 23°C / 50%RH. Afterwards, the snake-shaped LED substrate was bent 180° and the cured products of the above compositions 1 to 6 were visually checked for cracks. The evaluation criteria are as follows.

[0121] ○: No cracks occurred in the cured product

[0122] ×: Cracks occurred in the cured product

[0123] result

[0124] Table 1 shows the evaluation results of Compositions 1 to 6 and their cured products by the above-mentioned method.

[0125] Table 1

[0126]

[0127] *1: Ethyl acetoacetate not added

[0128] *2: γ-aminopropyltriethoxysilane is not added

[0129] The flow stop time (curing time) of the composition containing the first component B is shorter than the flow stop time (curing time) of the composition containing the first component A. This is because the content of ethyl acetoacetate in the component (B) that reacts with γ-aminopropyltriethoxysilane in the component (D) in the first component B is greater than that in the first component A, and more water molecules are produced as by-products.

[0130] It is to be noted that even when the combination of the first component A and the first component B and the combination of the second component A and the second component B were changed, it was confirmed that the rubber properties and the light transmittance were the desired values.

[0131] In Composition 5 or Composition 6, since ethyl acetoacetate or γ-aminopropyltriethoxysilane was not added, the curability was poor, and no cured product could be obtained even after 3 days, and the rubber properties thereof could not be measured. Therefore, the light transmittance could not be measured, and the bending test could not be performed.

[0132] Examples and comparative examples using other components (C) are described below.

[0133] Modulation of the second component C

[0134] At normal pressure, 20 parts by mass of dimethylpolysiloxane (non-reactive dimethyl silicone oil) with a viscosity of 100 mPa·s at 25°C and end-capped with trimethylsiloxy groups at both ends of the molecular chain, 3 parts by mass of tetra-n-propoxysilane, 2 parts by mass of γ-aminopropyltriethoxysilane and 0.03 parts by mass of dimethyltin dineodecanoate were mixed for 20 minutes to obtain a second component C.

[0135] Preparation of the second component D

[0136] At normal pressure, 20 parts by mass of dimethylpolysiloxane (non-reactive dimethyl silicone oil) with a viscosity of 100 mPa·s at 25°C and end-capped with trimethylsiloxy groups at both ends of the molecular chain, 3 parts by mass of tetra-n-propoxysilane, 3 parts by mass of γ-aminopropyltriethoxysilane and 0.03 parts by mass of dimethyltin dineodecanoate were mixed for 20 minutes to obtain a second component D.

[0137] [Example 5]

[0138] The first component A and the second component C were mixed at a mixing ratio of 4:1 (mass) for 5 minutes, and after obtaining the composition 7, the composition 7 was cured for 3 days under the conditions of 23°C / 50%RH in a manner to form a thickness of 2.5 mm, thereby obtaining a cured product of the composition 7.

[0139] [Example 6]

[0140] The first component B and the second component C were mixed at a mixing ratio of 4:1 (mass) for 5 minutes, and after obtaining the composition 8, the composition 8 was cured for 3 days under the conditions of 23°C / 50%RH in a manner to form a thickness of 2.5 mm, thereby obtaining a cured product of the composition 8.

[0141] [Example 7]

[0142] The first component A and the second component D were mixed at a mixing ratio of 4:1 (mass) for 5 minutes, and after obtaining the composition 9, the composition 9 was cured for 3 days under the conditions of 23°C / 50%RH in a manner to form a thickness of 2.5 mm, thereby obtaining a cured product of the composition 9.

[0143] [Example 8]

[0144] The first component B and the second component D were mixed at a mixing ratio of 4:1 (mass) for 5 minutes, and after obtaining the composition 10, the composition 10 was cured for 3 days under conditions of 23°C / 50%RH in a manner to form a thickness of 2.5 mm, thereby obtaining a cured product of the composition 10.

[0145] [Comparative Example 3]

[0146] Although an attempt was made to use the first component A without adding ethyl acetoacetate as the first component, and to mix the first component and the second component C at a mixing ratio of 4:1 (by mass) for 5 minutes, and after obtaining the composition 11, the composition 11 was cured for 3 days under the conditions of 23°C / 50% RH in a manner to have a thickness of 2.5 mm, the composition 11 was not sufficiently cured.

[0147] [Comparative Example 4]

[0148] Although an attempt was made to use the second component C without adding γ-aminopropyltriethoxysilane as the second component, and the first component A and the second component were mixed at a mixing ratio of 4:1 (mass) for 5 minutes, and after obtaining the composition 12, the composition 12 was cured for 3 days under conditions of 23°C / 50% RH in a manner to have a thickness of 2.5 mm, the composition 12 was not fully cured.

[0149] result

[0150] Table 2 shows the results of evaluation of Compositions 7 to 12 and their cured products by the above-mentioned method.

[0151] Table 2

[0152]

[0153] *1: Ethyl acetoacetate not added

[0154] *2: γ-aminopropyltriethoxysilane is not added

[0155] The flow stop time (curing time) of the composition containing the first component B is shorter than the flow stop time (curing time) of the composition containing the first component A. This is because the content of ethyl acetoacetate in the component (B) that reacts with γ-aminopropyltriethoxysilane in the component (D) in the first component B is greater than that in the first component A, and the by-produced water molecules are also greater.

[0156] It is to be noted that even when the combination of the first component A and the first component B is changed and the combination of the second component C and the second component D is modified, it can be confirmed that the rubber properties and the light transmittance are the desired values.

[0157] In Composition 11 or Composition 12, since ethyl acetoacetate or γ-aminopropyltriethoxysilane was not added, the curability was poor, and no cured product could be obtained even after 3 days, and the rubber properties could not be measured. Therefore, the light transmittance could not be measured, and the bending test could not be performed.

[0158] Even when tetra-n-propoxysilane (second component C and second component D) was used in the second component instead of tetraethoxysilane (second component A and second component B), it was confirmed that the rubber properties and light transmittance were the desired values.

Claims

1. A binary room temperature condensation curable organopolysiloxane composition, which consists only of a first component and a second component, wherein The first component consists of: Component (A): 100 parts by mass of a diorganopolysiloxane having both ends of the molecular chain blocked with hydroxyl groups; (B) component: 0.01 to 2 parts by mass of a β-keto acid ester compound based on 100 parts by mass of the (A) component; The second component consists of: (C) component: 0.1 to 15 parts by mass of a hydrolyzable organosilane compound having three or more organooxy groups bonded to silicon atoms in one molecule and / or a partially hydrolyzed condensate thereof, based on 100 parts by mass of the (A) component; (D) component: 0.1 to 5 parts by mass of an amino group-containing hydrolyzable organosilane compound other than the component (C) and / or a partially hydrolyzed condensate thereof, based on 100 parts by mass of the component (A); (E) component: 0.001 to 5 parts by mass of a curing catalyst based on 100 parts by mass of the (A) component; and Non-reactive dimethicone; The curing catalyst is an organic carboxylate or alkoxide of at least one metal selected from tin, titanium, zirconium, iron, antimony, bismuth and manganese; The binary room temperature condensation-curable organopolysiloxane composition can provide a silicone rubber cured product having a light transmittance of 80% or more in the wavelength range of 400 to 800 nm after curing for 3 days at 23° C. / 50% RH for a cured product with a thickness of 2.5 mm.

2. The binary room temperature condensation-curable organopolysiloxane composition according to claim 1, It contains no inorganic fillers.

3. The binary room temperature condensation-curable organopolysiloxane composition according to claim 1 or 2, It is used in optics.

4. The binary room temperature condensation curable organopolysiloxane composition according to claim 1, wherein The present invention can provide a silicone rubber cured product, wherein when a cured product layer of the silicone rubber cured product having a thickness of 3 mm formed on the outer surface of a substrate is bent inwardly by 180° together with the substrate, cracks will not be generated in the cured product layer.

5. The binary room temperature condensation curable organopolysiloxane composition according to claim 1 or 2, wherein The amount of the amine groups in the component (D) is 1 to 5 molar equivalents to the carbonyl groups in the β-ketoester compound of the component (B).

6. The binary room temperature condensation-curable organopolysiloxane composition according to claim 1 or 2, The mass ratio of the first component to the second component is 50:50 to 90:

10.

7. A product, The cured product of the binary room temperature condensation-curable organopolysiloxane composition according to claim 1 or 2 is used for bonding, coating or packaging.

8. A method for curing a binary room temperature condensation-curable organopolysiloxane composition according to any one of claims 1 to 6, The method comprises the steps of applying the first component composed of the component (A) and the component (B) on the surface of a first substrate, applying the second component composed of the component (C), the component (D), the component (E), and the non-reactive dimethyl silicone oil on the surface of a second substrate, and bringing the substrates facing each other and in contact with each other in such a manner that the first component and the second component are in contact with each other, and then laminating and curing the first component and the second component.

Images