Crosslinkable composition and method for producing coatings using the same

Abstract

Provided is a crosslinkable composition that can be cured to form a coating that has good repeatable paintability and excellent repeatable removability, is smooth, and exhibits certain hardness. Crosslinkable composition comprising, as components (A)-(I), diorganopolysiloxanes whose molecular chain ends are terminated with triorganosilyl groups, as components (A)-(II), diorganopolysiloxanes having a specific amino group and a specific alkoxy group, as component (B), a certain silane and / or a partial hydrolysate thereof, as component (C) an alkoxysilane having two or more alkoxy groups having 5 or less carbon atoms; and an organosilicon compound having a group containing an NH2 group as component (D).

Description

Technical Field

[0001] The present invention relates to a crosslinkable composition based on organosilicon compounds, and to a method for producing and using the crosslinkable composition, in particular to the use of the crosslinkable composition for forming a coating that allows repeated painting and repeated removal.

[0002] Graffiti on surfaces of building facades, stone structures, railway vehicles, bridge piers, fences, traffic signs, etc. has become a social problem. Therefore, anti-graffiti sheets and coatings have been developed.

[0003] For example, PTL 1 aims to provide a silicone composite antifouling sheet that exhibits stable long-term antifouling properties, cleanability, ease of cleaning, and wear resistance, can be easily attached to an adherend, and can have its shape conform to cracks and displacements on the application surface. Therefore, PTL 1 discloses a silicone composite antifouling sheet that includes a base layer composed of a fluororesin and a silicone adhesive layer laminated on one surface of the base layer.

[0004] PTL 2 discloses a crosslinkable composition useful for an anti-graffiti coating that adheres well to the underlying surface without primer pretreatment but is mostly not adhered to by graffiti.

[0005] All the sheets and coatings for preventing graffiti represented by the above-mentioned documents have properties that make it difficult for graffiti to adhere and easy to remove graffiti. Therefore, the surface on which graffiti hardly adheres has poor paintability, resulting in a problem that it cannot be painted with a sufficient aesthetic appearance.

[0006] Furthermore, in PTL 1, although graffiti can be removed with tape, there is a problem that it takes time and labor to remove graffiti over a large area.

[0007] Citation List

[0008] Patent Literature

[0009] PTL 1: Japanese Patent Application Laid-Open No. 2022-092493

[0010] PTL 2: Japanese translation of PCT Patent Application Publication No. 2019-527245 (corresponding to WO2018 / 162033) Summary of the invention

[0011] Technical issues

[0012] In recent years, the use of the following paint has become increasingly popular. That is, paint is applied to the surface of a concrete wall, etc., and after observing the paint for a period of time, it is removed and replaced with another paint. Alternatively, paint, notes, etc. on an outdoor iron plate are repeatedly erased and replaced.

[0013] In such applications, it is necessary to form a coating which not only allows easy removal of the paint attached to the layer but also has good paintability and writability to prevent the paint from being repelled or washed off.

[0014] Furthermore, in order to apply a paint with a good appearance, the coating as the surface to be painted needs to be smooth and have a certain degree of hardness.

[0015] Especially when large painted surfaces are used outdoors, it is desirable to be able to remove paint from the coating with a stream of water instead of solvents, dry erasers, tapes, etc., from the standpoint of easy handling, reduced environmental impact, and safety.

[0016] For example, the anti-graffiti coating using the composition disclosed in PTL 2 has the following problems: the paint to be applied to the coating surface does not adhere thereto to a great extent, resulting in painting failure, or the paint is repelled on the coating surface, making it difficult to maintain a sufficient aesthetic appearance.

[0017] In view of the above, an object of the present invention is to provide a crosslinkable composition which can be cured to form a coating having good repaintability, excellent re-removability and a certain hardness.

[0018] Solution to the problem

[0019] The present inventors have found that the above-mentioned problems can be solved by a crosslinkable composition comprising the following components, thereby completing the present invention: components (A) to (I), which are diorganopolysiloxanes whose molecular chain terminals are blocked with triorganosilyl groups; components (A) to (II), which are diorganopolysiloxanes having specific amino groups and specific alkoxy groups; component (B), which are certain silanes and / or partial hydrolyzates thereof; component (C), which are alkoxysilanes having two or more alkoxy groups having 5 or less carbon atoms; and component (D), which are organosilicon compounds having a group containing an NH2 group.

[0020] Specifically, the present invention provides a crosslinkable composition comprising:

[0021] Components (A) to (I) are diorganopolysiloxanes having a linear or branched structure, the molecular chain ends of which are capped with triorganosilyl groups;

[0022] Components (A)-(II) having at least two (R2 R 3 NCH2) groups and at least four (OR 4 ) group of straight chain or branched structure of diorganopolysiloxane

[0023] (R 2 represents a hydrogen atom or an optionally substituted monovalent straight or branched hydrocarbon group having 1 to 6 carbon atoms,

[0024] R 3 is an optionally substituted monovalent straight or branched hydrocarbon group having 1 to 6 carbon atoms, a cyclic saturated hydrocarbon group having 5 or 6 carbon atoms, or a phenyl group, and

[0025] R 4 , which may be the same as or different from each other, and each represents an optionally substituted monovalent hydrocarbon group);

[0026] Component (B), which is a silane represented by the following formula (1) and / or a partial hydrolyzate thereof,

[0027] (R 2 R 3 NCH2)Si(OR 4 )3(1);

[0028] Component (C), which is an alkoxysilane represented by the following formula (2),

[0029] R 21 4-x Si(OR 22 ) x (2)

[0030] (In formula (2), R 21 , which may be the same as or different from each other, represent an optionally substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and

[0031] R 22 , which may be the same as or different from each other, each representing an optionally substituted monovalent hydrocarbon group having 1 to 5 carbon atoms, wherein x is 2, 3 or 4); and

[0032] Component (D), which is an organosilicon compound comprising a unit represented by the following formula (3), wherein at least one group D is present per molecule, and at least one group D has an NH2 group,

[0033] D f Si(OR 32 ) e R 31 d O (4-d-e-f) / 2 (3)

[0034] (In formula (3), R 31, which may be the same as or different from each other, represent optionally substituted, nitrogen-free, monovalent SiC-bonded organic groups,

[0035] R 32 , which may be the same as or different from each other, represent a hydrogen atom or an optionally substituted hydrocarbon group,

[0036] D, which may be the same as or different from each other, represents a monovalent SiC-bonded group having at least one nitrogen atom which is not bonded to a carbonyl group (C═O),

[0037] d is 0 or 1,

[0038] e is 0, 1, 2, or 3,

[0039] f is 0 or 1, and

[0040] The sum of d, e and f is 4 or less).

[0041] The crosslinkable composition is applied to a substrate such as concrete and cured to form a coating. When a paint is applied to the surface of the coating, the coating exhibits good paintability without craters, etc., and also exhibits good removability when the applied paint is removed, thereby exhibiting little paint residue. In addition, the coating maintains good paintability and removability after multiple application / removal cycles. Therefore, the coating can be used as a coating that allows repeated painting and repeated removal.

[0042] The paint applied to the coating of the present invention is not particularly limited. Examples of paints include lacquers, powder paints, aqueous (water-based) paints and synthetic resin paints, such as epoxy resin paints, polyurethane resin paints, fluororesin paints, polyester resin paints, melamine resin paints and acrylic resin paints.

[0043] The crosslinkable composition of the present invention may be in any aspect and form as long as it is in the form of at least one or more liquids and can be cured by moisture to finally form a cured product of the composition.

[0044] Components (A)-(I) have good compatibility with each of components (A)-(II), (B), (C) and (D) (which are silanes or siloxanes). Therefore, components (A)-(I) in an uncured state exist in a state uniformly dispersed in a crosslinkable composition comprising these components. When a crosslinkable composition in which each component is uniformly mixed is applied to a substrate such as concrete or wood, it undergoes a crosslinking reaction with water content such as moisture in the air and produces a coating by wet curing. The formed coating includes a matrix formed by crosslinking of components (A)-(II), (B), (C) and (D), and also includes components (A)-(I) dispersed in the matrix and not participating in the crosslinking reaction.

[0045] In this method, components (A)-(II) have (R 2 R 3 NCH2) groups and (OR 4 ) groups and the NH2 groups possessed by component (D) promote adhesion of the coating to the substrate, so that the coating adheres well to the substrate.

[0046] On the other hand, since the components (A)-(I) without crosslinkable groups do not participate in matrix formation, after the crosslinkable composition is cured, the components (A)-(I) seep out to the surface of the coating over time. When a paint or the like is applied to the surface of the coating, the paint can be removed by a solvent, by scrubbing with a cloth, a sponge, or by an adhesive tape, etc. However, since the components (A)-(I) have water repellency and oil repellency, the paint can be easily removed by a water stream without using a solvent, an adhesive tape, or the like.

[0047] If the amount of oozing out of components (A) to (I) is excessive, although the paint can be easily removed, the paint is repelled by the coating surface, resulting in a problem that the paint cannot be applied with a sufficient aesthetic appearance.

[0048] However, in the present invention, the presence of component (C), i.e. alkoxysilane, in the matrix increases the hardness of the coating and simultaneously reduces the amount of exudation of components (A)-(I) to the surface of the coating compared to the absence of component (C). Therefore, even with a coating obtained by curing a composition comprising components (A)-(I), the surface can be painted with a sufficient aesthetic appearance without shrinkage cavities. In addition, even when the coating comprises component (C), a certain amount of components (A)-(I) also exudes to the surface of the coating, thereby maintaining the removability of the paint.

[0049] In a coating containing component (C), when the paint is removed by a stream of water, components (A) to (I) remain on the surface of the coating without being washed off due to their water repellency, and components (A) to (I) gradually seep out from the inside of the coating over a long period of time. Therefore, even if painting and paint removal are repeated, the characteristic that the paint can be easily removed can be maintained for a long period of time.

[0050] In addition, it was confirmed that the hardness of the coating containing component (C) was enhanced compared with a coating not containing component (C) or a coating containing an alkoxysilane having two or more alkoxy groups with 6 or more carbon atoms. Even when the paint is repeatedly applied and removed, the high hardness coating is less likely to crack and peel off from the substrate. Therefore, it is particularly suitable for long-term repeated use and outdoor use.

[0051] Component (C) itself also has low viscosity and reduces the viscosity of the crosslinkable composition as a whole before curing. Therefore, when the composition is applied to a substrate, its workability is good. Since the composition can be applied uniformly and thinly, a smooth surface of the coating can be obtained, so that the paint applied to the coating surface shows a good aesthetic appearance. DETAILED DESCRIPTION

[0052] Herein, the present invention will be described in detail.

[0053] According to a first aspect of the present invention, a crosslinkable composition comprises:

[0054] Components (A) to (I) are diorganopolysiloxanes having a linear or branched structure, the molecular chain ends of which are capped with triorganosilyl groups;

[0055] Components (A)-(II) having at least two (R 2 R 3 NCH2) groups and at least four (OR 4 ) group of straight chain or branched structure of diorganopolysiloxane

[0056] (R 2 represents a hydrogen atom or an optionally substituted monovalent straight or branched hydrocarbon group having 1 to 6 carbon atoms,

[0057] R 3 is an optionally substituted monovalent straight or branched hydrocarbon group having 1 to 6 carbon atoms, a cyclic saturated hydrocarbon group having 5 or 6 carbon atoms, or a phenyl group, and

[0058] R 4 , which may be the same as or different from each other, and each represents an optionally substituted monovalent hydrocarbon group);

[0059] Component (B), which is a silane represented by the following formula (1) and / or a partial hydrolyzate thereof,

[0060] (R 2 R 3 NCH2)Si(OR 4 )3(1);

[0061] Component (C), which is an alkoxysilane represented by the following formula (2),

[0062] R 21 4-x Si(OR 22 ) x (2)

[0063] (In formula (2), R 21, which may be the same as or different from each other, represent an optionally substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and

[0064] R 22 , which may be the same as or different from each other, each representing an optionally substituted monovalent hydrocarbon group having 1 to 5 carbon atoms, wherein x is 2, 3 or 4); and

[0065] Component (D), which is an organosilicon compound comprising a unit represented by the following formula (3), wherein at least one group D is present per molecule, and at least one group D has an NH2 group,

[0066] D f Si(OR 32 ) e R 31 d O (4-d-e-f) / 2 (3)

[0067] (In formula (3), R 31 , which may be the same as or different from each other, represent optionally substituted, nitrogen-free, monovalent SiC-bonded organic groups,

[0068] R 32 , which may be the same as or different from each other, represent a hydrogen atom or an optionally substituted hydrocarbon group,

[0069] D, which may be the same as or different from each other, represents a monovalent SiC-bonded group having at least one nitrogen atom which is not bonded to a carbonyl group (C═O),

[0070] d is 0 or 1,

[0071] e is 0, 1, 2, or 3,

[0072] f is 0 or 1, and

[0073] The sum of d, e and f is 4 or less).

[0074] According to the second aspect of the present invention, the above-mentioned crosslinkable composition can serve as a composition for forming a coating layer that allows repeated painting.

[0075] The term "coating that allows repeated painting" as used herein refers to the coating per square meter ( / m 2 ) A coating having 10 or fewer shrinkage cavities with a diameter φ of 2 mm or less (φ<2 mm) and no shrinkage cavities with a diameter φ of 2 mm or greater (φ≥2 mm) per square meter, as determined by the repeated paintability evaluation method described below.

[0076] Repeat paintability evaluation method:

[0077] The crosslinkable composition is applied to a substrate and then cured to form a coating.

[0078] On the surface of the resulting coating, acrylic spray paint (brown) manufactured by Nippon Paint Co., Ltd. was sprayed in an area of ​​30 cm×20 cm from 30 cm above the coating surface (before drying, the application amount was 100 g / m 2 ). After standing for 2 hours, the paint was removed by spraying water on the paint at a distance of 10 cm from the coating surface using a household high-pressure cleaner. These processes were repeated 10 times to obtain surface evaluation test pieces for repeated paintability evaluation.

[0079] On the surface evaluation test piece for repeated paintability evaluation, acrylic spray paint (brown) manufactured by Nippon Paint Co., Ltd. was sprayed in an area of ​​30 cm×20 cm from 30 cm above the coating surface, and the presence or absence of shrinkage cavities was visually checked.

[0080] The following are the evaluation criteria for repaintability.

[0081] A: No visible shrinkage cavities

[0082] B: more than 0 and less than 10 shrinkage holes (where φ<2mm) / m 2 And there is no shrinkage cavity of φ≥2mm

[0083] C: 10 or more shrinkage holes (φ<2mm) / m 2 , more than 0 and less than 10 shrinkage holes (2mm≤φ<5mm) / m 2 , and there is no shrinkage cavity of φ≥5mm

[0084] D: 10 or more shrinkage holes (2mm≤φ<5mm) / m 2 , and there is no shrinkage cavity of φ≥5mm

[0085] E: There are shrinkage holes with a diameter of φ≥5mm

[0086] Therefore, the coating obtained by curing the crosslinkable composition according to the present invention was evaluated as grade A or B by the above-mentioned evaluation method.

[0087] The crosslinkable composition may be a crosslinkable composition according to the third aspect of the present invention, characterized in that the crosslinkable composition comprises components (A)-(I), (A)-(II), (B), (C) and (D), and the addition of component (c) enhances the re-paintability of the coating obtained by curing the crosslinkable composition.

[0088] Component (A)-(I):

[0089] After the crosslinkable composition is cured, components (A) to (I) penetrate from the interior of the coating to the surface of the coating, and the components help remove the paint applied to the surface of the coating.

[0090] Specifically, components (A)-(I) are non-functional diorganopolysiloxanes having a linear or branched structure, the molecular chain ends of which are terminated by triorganosilyl groups, wherein the structure has a main chain consisting of diorganosiloxane units as repeating units. Specifically, the main chain consists of repeating units represented by the following formula (4), wherein c is 1 or 2:

[0091] R c SiO 4-c / 2 (4).

[0092] The number of repeating units per molecule of components (A) to (I) (polymerization degree) may be 1 to 500, and preferably 10 to 200, and more preferably 10 to 100. The polymerization degree can be measured, for example, as a number average polymerization degree (or number average molecular weight) in terms of a polystyrene equivalent value in gel permeation chromatography analysis using toluene or the like as a developing solvent.

[0093] Components (A) to (I) may contain Si-OH groups at the molecular chain ends and / or at a portion of the side chains of the molecular chains. In this case, the content of the Si-OH groups is preferably 5 mol % or less, more preferably 1 mol % or less, even more preferably 0.1 mol % or less, relative to R in components (A) to (I).

[0094] The group R (when c is 2) is determined independently, and examples of the group R include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, 1-n-butyl, 2-n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl groups such as n-hexyl, heptyl groups such as n-heptyl, octyl groups such as n-octyl and isooctyl (including 2,2,4-trimethylpentyl), nonyl groups such as n-nonyl, decyl groups such as n-decyl, dodecyl groups such as n-dodecyl, octadecyl groups such as n-octadecyl; cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl and methylcyclohexyl; alkenyl groups such as 1-propenyl and 2-propenyl; aryl groups such as phenyl, naphthyl, anthracenyl and phenanthryl; alkylaryl groups such as o-tolyl, m-tolyl, p-tolyl, xylyl and ethylphenyl; and aralkyl groups such as benzyl, α-phenylethyl and β-phenylethyl.

[0095] When R is a substituted group and c is 2, the groups R are each independently determined, and examples of the groups R include halogenated alkyl groups such as 3,3,3-trifluoroprop-1-yl, 1,1,1,3,3,3-hexafluoroprop-2-yl and heptafluoroprop-2-yl.

[0096] The group R is preferably a monovalent hydrocarbon group having 1 to 18 carbon atoms which is optionally substituted by a halogen atom, more preferably an alkyl group, particularly preferably a methyl group.

[0097] Components (A) to (I) used in the present invention are preferably liquid at 25° C. and 1,000 hPa.

[0098] Components (A)-(I) used in the present invention may have a viscosity of 20 to 100,000 mPa·s at 25° C., preferably 50 to 10,000 mPa·s, even more preferably 70 to 500 mPa·s.

[0099] A type of diorganopolysiloxane having a viscosity within the above range can be used alone as component (A)-(I), or two or more types thereof can be used in combination as appropriate. When the viscosity falls within the above range, the viscosity of the crosslinkable composition as a whole before curing falls within an appropriate range, so that the processability is good, and the smoothness of the resulting coating is good. In particular, in applications where the viscosity of the crosslinkable composition as a whole needs to be kept low so that the processability needs to be improved, the viscosity can be in the range of, for example, 70mPa·s to 500mPa·s. On the other hand, the following situation is assumed: a high viscosity of the entire crosslinkable composition is allowed, and it is necessary to slow the exudation rate of component (A)-(I), while maintaining the re-paintability and re-removability of the resulting coating over a long period of time. In this case, a compound with a higher viscosity can be used as part or all of component (A)-(I).

[0100] Note that, unless otherwise specified, the viscosity described herein is a value measured using a rotational viscometer (in accordance with JIS K7117-2) at 25° C. and a shear rate of 10 / s.

[0101] The blending amount of components (A)-(I) may be 1 part by mass or more and less than 20 parts by mass, more preferably 2 parts by mass or more and 15 parts by mass or less, and even more preferably 5 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the total amount of components (A)-(I) and (A)-(II).

[0102] When the content of components (A) to (I) falls within the above range, surface adhesion of the coating layer or a phenomenon in which the coating layer repels a paint applied to the surface thereof can be suppressed.

[0103] Components (A)-(I) (diorganopolysiloxane) may be selected from commercially available compounds or compounds prepared by methods known to those skilled in the art.

[0104] Components (A)-(II):

[0105] Components (A) to (II) are the main components constituting the matrix formed by curing the crosslinkable composition, and also serve to promote good adhesion of the coating obtained after curing to the substrate.

[0106] Components (A) to (II) are each having at least two (R 2 R 3 NCH2) groups and at least four (OR 4 ) groups. Specifically, components (A)-(II) are composed of repeating units represented by the following formula (4) and the following formula (5), wherein the following formula (4) is the same as that for components (A)-(I):

[0107] R c SiO 4-c / 2 (4), and

[0108] (R 2 R 3 NCH2)(OR 4 ) m SiO 3-m / 2 (5).

[0109] In this paper, R 2 represents a hydrogen atom or an optionally substituted monovalent straight or branched hydrocarbon group having 1 to 6 carbon atoms,

[0110] R 3 is an optionally substituted monovalent straight or branched hydrocarbon group having 1 to 6 carbon atoms, a cyclic saturated hydrocarbon group having 5 or 6 carbon atoms, or a phenyl group, and

[0111] R 4 , which may be the same as or different from each other, each represent an optionally substituted monovalent hydrocarbon group.

[0112] The degree of polymerization of the main chain of components (A) to (II) may be 1 to 2,500, preferably 10 to 1,000, more preferably 10 to 800, per molecule.

[0113] One type of diorganopolysiloxane having a main chain polymerization degree falling within the above range may be used alone as component (A)-(II), or two or more types thereof may be used in combination as appropriate. When the polymerization degree falls within the above range, the hardness of the coating obtained from the crosslinkable composition can be set to an appropriate range.

[0114] Components (A) to (II) may contain Si-OH groups at the molecular chain ends and / or at a portion of the side chains of the molecular chains. In this case, relative to (OR 4), the content of Si-OH groups is preferably 5 mol % or less, more preferably 1 mol % or less, even more preferably 0.1 mol % or less.

[0115] Hydrocarbon R 2 Examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, 1-n-butyl, 2-n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl and hexyl groups such as n-hexyl.

[0116] Group R 2 Preferred is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group or a 1-n-butyl group, more preferred is an ethyl group or a 1-n-butyl group, or particularly preferred is an n-butyl group.

[0117] Group R 3 Examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, 1-n-butyl, 2-n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, and hexyl groups such as n-hexyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; and phenyl groups.

[0118] Group R 3 Preferred is a methyl group, an ethyl group, an n-propyl group, a 1-n-butyl group or a cyclohexyl group, more preferably an ethyl group, an n-butyl group or a cyclohexyl group, or particularly preferably an n-butyl group.

[0119] Preferably, the group R 2 and R 3 are the same group.

[0120] Group (R 2 R 3 NCH2) is preferably N,N-dimethylaminomethyl, N,N-diethylaminomethyl, N,N-di-n-propylaminomethyl, N,N-di-n-butylaminomethyl, N-n-butylaminomethyl, N-but-2-ylaminomethyl, N-cyclopentylaminomethyl or N,N-cyclohexylaminomethyl, more preferably N,N-dimethylaminomethyl, N,N-diethylaminomethyl, N,N-di-n-propylaminomethyl or N,N-di-n-butylaminomethyl, or particularly preferably N,N-di-n-butylaminomethyl.

[0121] Group R 4 Examples of include those defined for the group R. Specifically, the group R 4 Preferably each independently is an alkyl group having 1 to 6 carbon atoms, particularly preferably a methyl group or an ethyl group.

[0122] The blending amount of components (A)-(II) may be 80 parts by mass or more and less than 99 parts by mass, more preferably greater than 85 parts by mass and less than 98 parts by mass, even more preferably greater than 90 parts by mass and less than 95 parts by mass or less, relative to 100 parts by mass of the total amount of components (A)-(I) and (A)-(II).

[0123] The total amount of components (A)-(I) and (A)-(II) may be 20 parts by mass or more and 95 parts by mass or less, more preferably 30 parts by mass or more and 90 parts by mass or less, even more preferably 40 parts by mass or more and 85 parts by mass or less, relative to 100 parts by mass of the total amount of the entire crosslinkable composition.

[0124] When the contents of components (A)-(I) and (A)-(II) fall within the above respective ranges, good removability and good paintability can be simultaneously obtained.

[0125] Components (A) to (II) used in the present invention are known compounds and can be prepared, for example, by dealcoholating an α,ω-dihydroxydiorganopolysiloxane (A0) with a silane represented by the formula (1).

[0126] (R 2 R 3 NCH2)Si(OR 4 )3(1)

[0127] If desired, components (A) to (II) can also be prepared in situ during the production of the crosslinkable composition according to the invention. The α,ω-dihydroxydiorganopolysiloxane (A0) used to prepare components (A) to (II) used in the present invention has a number average molar mass Mn of preferably less than 45,000 g / mol, more preferably less than 40,000 g / mol, even more preferably less than 35,000 g / mol, particularly preferably less than 30,000 g / mol.

[0128] The units represented by formula (4) present in the components (A) to (II) used in the present invention are preferably those in which c is substantially 2. As a result of the preparation, the components (A) to (II) may also contain units represented by formula (4) in which c is 1. The components (A) to (II) used according to the present invention preferably contain at most one unit represented by formula (4) in which c is 1 per molecule, and particularly preferably contain no such unit.

[0129] Components (A) to (II) used in the present invention are preferably represented by the following formula (6):

[0130] [(R 4 O)2(R 2 R 3NCH2)SiO-(SiR2O) n -] o (OR 4 ) 2-o (R 2 R 3 NCH2)SiO-(SiR2O) n -Si(R 2 R 3 NCH2)(OR 4 ) 2-o [O-(SiR2O) n -Si(R 2 R 3 NCH2)(OR 4 )2] o (6)

[0131] In formula (6), o may be the same as or different from each other, and represents 0, 1 or 2. In addition, n may be the same as or different from each other, and represents an integer of 10 to 600.

[0132] -(SiR2O) in formula (6) n The moieties each independently have a number average molar mass Mn of preferably less than 45,000 g / mol, more preferably less than 40,000 g / mol, even more preferably less than 35,000 g / mol and particularly preferably less than 30,000 g / mol.

[0133] Examples of components (A) to (II) used in the present invention include:

[0134] (EtO)2[(n-C4H9)2NCH2]SiO-(SiMe2O) x -Si[CH2N(n-C4H9)2](OEt)2,

[0135] (EtO)2[(n-C4H9)2NCH2]SiO-(SiMe2O) x (OEt)[(n-C4H9)2NCH2]SiO-(SiMe2O) x -Si[CH2N(n-C4H9)2](OEt)2,

[0136] (EtO)2[(n-C4H9)2NCH2]SiO-(SiMe2O) x (OEt)[(n-C4H9)2NCH2]SiO-(SiMe2O) x -Si[CH2N(n-C4H9)2](OEt)-(SiMe2O) x -Si[CH2N(n-C4H9)2](OEt)2,

[0137] [(EtO)2[(n-C4H9)2NCH2]SiO-(SiMe2O) x ]2[(n-C4H9)2NCH2]SiO-(SiMe2O) x -Si[CH2N(n-C4H9)2]((OEt)2,

[0138] [(EtO)2[(n-C4H9)2NCH2]SiO-(SiMe2O) x ]2[(n-C4H9)2NCH2]SiO-(SiMe2O) x -Si[CH2N(n-C4H9)2](OEt)-(SiMe2O) x -Si[CH2N(n-C4H9)2](OEt)2, and

[0139] [(EtO)2[(n-C4H9)2NCH2]SiO-(SiMe2O) x ]2[(n-C4H9)2NCH2]SiO-(SiMe2O) x -Si[CH2N(n-C4H9)2][-(SiMe2O) x -Si[CH2N(n-C4H9)2](OEt)2]2. Specifically, component (A)-(II) is preferably (EtO)2[(n-C4H9)2NCH2]SiO-(SiMe2O) x -Si[CH2N(n-C4H9)2](OEt)2 or (EtO)2[(n-C4H9)2NCH2]SiO-(SiMe2O) x (OEt)[(n-C4H9)2NCH2]SiO-(SiMe2O) x -Si[CH2N(n-C4H9)2](OEt)2, and particularly preferably (EtO)2[(n-C4H9)2NCH2]SiO-(SiMe2O) x -Si[CH2N(n-C4H9)2](OEt)2. In the formula, Me is a methyl group, Et is an ethyl group, and x may be the same as or different from each other and represents an integer of 10 to 405.

[0140] Components (A) to (II) used in the present invention are preferably liquid at 25° C. and 1,000 hPa.

[0141] Components (A) to (II) used in the present invention may have a viscosity of 400 to 20,000 mPa·s, preferably 800 to 15,000 mPa·s, and even more preferably 1,000 to 10,000 mPa·s at 25° C. When the viscosity thereof falls within this range, the viscosity of the crosslinkable composition as a whole before curing falls within an appropriate range, and thus the workability and smoothness of the resulting coating are good.

[0142] Component (B):

[0143] Component (B) in the present invention is a silane represented by the following formula (1) and / or a partial hydrolyzate thereof:

[0144] (R 2 R 3 NCH2)Si(OR 4 )3(1).

[0145] Component (B) used in the present invention is a known compound and can be easily prepared by conventional methods in silicon chemistry.

[0146] Examples of component (B) used in the present invention include:

[0147] N,N-dimethylaminomethyltriethoxysilane,

[0148] N,N-Diethylaminomethyltriethoxysilane,

[0149] N,N-Di-n-propylaminomethyltriethoxysilane,

[0150] N,N-di-n-butylaminomethyltriethoxysilane,

[0151] N-butylaminomethyltriethoxysilane,

[0152] N-Butyl-2-aminomethyltriethoxysilane,

[0153] N-Cyclopentylaminomethyltriethoxysilane,

[0154] N-Cyclohexylaminomethyltriethoxysilane,

[0155] N,N-dimethylaminomethyltrimethoxysilane,

[0156] N,N-Diethylaminomethyltrimethoxysilane,

[0157] N,N-di-n-propylaminomethyltrimethoxysilane,

[0158] N,N-di-n-butylaminomethyltrimethoxysilane,

[0159] N-butylaminomethyltrimethoxysilane,

[0160] N-Butyl-2-aminomethyltrimethoxysilane,

[0161] N-Cyclopentylaminomethyltrimethoxysilane,

[0162] N-cyclohexylaminomethyltrimethoxysilane, and partial hydrolysis products of these. Specifically, component (B) is preferably

[0163] N,N-dimethylaminomethyltriethoxysilane,

[0164] N,N-Diethylaminomethyltriethoxysilane,

[0165] N,N-Di-n-propylaminomethyltriethoxysilane,

[0166] N,N-di-n-butylaminomethyltriethoxysilane,

[0167] N-Cyclopentylaminomethyltriethoxysilane,

[0168] N-cyclohexylaminomethyltriethoxysilane, or a partial hydrolysis product thereof. Component (B) is particularly preferably

[0169] N,N-Diethylaminomethyltriethoxysilane,

[0170] N,N-di-n-butylaminomethyltriethoxysilane,

[0171] N-Cyclohexylaminomethyltriethoxysilane, or a partial hydrolysis product thereof.

[0172] If component (B) takes the form of a partial hydrolyzate of the silane represented by formula (1), component (B) is preferably a partial hydrolyzate having 2 to 10 silicon atoms.

[0173] The content of component (B) in the crosslinkable composition according to the present invention may be 5 parts by mass or more and 20 parts by mass or less, preferably 5 parts by mass or more and 15 parts by mass or less, and even more preferably 5 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the total amount of components (A)-(I) and (A)-(II).

[0174] Component (B) helps to form a matrix with the cross-linking reaction of components (A)-(II), (C) and (D). Therefore, the component (B) included in an amount falling within the above-mentioned range can keep the cross-linking density within a suitable range, and can form a coating with sufficient hardness. In addition, the component (B) included in such an amount can keep the good removability of the paint vehicle while keeping the good adhesion between the substrate and the coating.

[0175] Component (C):

[0176] Component (C) which is an alkoxysilane is a component incorporated to increase the hardness of the coating by crosslinking into the matrix formed by the crosslinkable composition and to keep the bleed-out amount of components (A) to (I) to the coating surface reduced.

[0177] The low viscosity of component (C) can reduce the viscosity of the crosslinkable composition as a whole, and the workability when the crosslinkable composition is applied to a substrate is improved. The composition containing component (C) can be uniformly applied to a substrate without causing unevenness, and thus a smooth coating can be obtained after curing.

[0178] Component (C) is an alkoxysilane represented by the following formula (2), and preferably has no nitrogen atom:

[0179] R 21 4-x Si(OR 22 ) x (2)

[0180] (In formula (2), R 21 , which may be the same as or different from each other, represent an optionally substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and

[0181] R 22 , which may be the same as or different from each other, each represent an optionally substituted monovalent hydrocarbon group having 1 to 5 carbon atoms, wherein x is 2, 3 or 4).

[0182] Independently determine the group R 21 (when x is 2), and the group R 21 Examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, 1-n-butyl, 2-n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl groups such as n-hexyl, heptyl groups such as n-heptyl, octyl groups such as n-octyl and isooctyl (including 2,2,4-trimethylpentyl), nonyl groups such as n-nonyl, decyl groups such as n-decyl, dodecyl groups such as n-dodecyl, octadecyl groups such as n-octadecyl; cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl and methylcyclohexyl; alkenyl groups such as 1-propenyl and 2-propenyl; aryl groups such as phenyl, naphthyl, anthracenyl and phenanthryl; alkylaryl groups such as o-tolyl, m-tolyl, p-tolyl, xylyl and ethylphenyl; and aralkyl groups such as benzyl, α-phenylethyl and β-phenylethyl.

[0183] When R 21 is a substituted group and x is 2, each independently determines the group R 21 , and the group R 21Examples include halogenated alkyl groups such as 3,3,3-trifluoroprop-1-yl, 1,1,1,3,3,3-hexafluoroprop-2-yl, and heptafluoroprop-2-yl.

[0184] Group R 21 It is preferably an unsubstituted straight-chain or branched alkyl group or a phenyl group having 1 to 6 carbon atoms, particularly preferably a methyl group, an ethyl group, a vinyl group, an n-pentyl group or an n-hexyl group. 21 With 6 or less carbon atoms, a coating having sufficient hardness can be obtained.

[0185] Group R 21 A non-aromatic hydrocarbon group is preferred because the removability is further improved.

[0186] Group R 22 Each is a group as defined for the R group.

[0187] Group R 22 Preferably each is independently an alkyl group having 1 to 6 carbon atoms, particularly preferably a methyl group or an ethyl group, most preferably an ethyl group.

[0188] In formula (2), x represents 2, 3 or 4, preferably 3 or 4, and even more preferably 4. When x is 3 or more, the hardness of the obtained coating is more suitable. For example, when x is 3 or more, the Shore A hardness of the obtained coating can be 30 or more, and when x is 4 or more, the Shore A hardness can be 40 or more.

[0189] Examples of component (C) include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetraisobutoxysilane, tetra-tert-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltri-n-propoxysilane, n-butyltrimethoxysilane and n-butyltrimethiethoxysilane.

[0190] The blending amount of component (C) may be 10 parts by mass or more and less than 200 parts by mass, more preferably 15 parts by mass or more and 150 parts by mass or less, and even more preferably 20 parts by mass or more and 100 parts by mass or less, relative to 100 parts by mass of the total amount of components (A)-(I) and (A)-(II).

[0191] When component (C) is included in an amount falling within the above range, the hardness of the resulting coating can be set to an appropriate range (for example, a Shore A hardness of 30 or more and 60 or less), and the amount of exudation of components (A)-(I) to the coating surface can be set to an appropriate range.

[0192] Component D:

[0193] Component (D) as an organosilicon compound is a catalyst for the crosslinking reaction of the crosslinkable composition and also acts as a reactive catalyst incorporated into the matrix formed by the crosslinking reaction to form a coating. Component (D) also has the function of enhancing the adhesion of the coating to the substrate.

[0194] In the crosslinkable composition of the present invention, a catalyst other than component (D) may be used as a catalyst combination, but the use of a catalyst containing a metal is undesirable from the viewpoint of environment and safety.

[0195] Component (D) is an organosilicon compound comprising a unit represented by the following formula (3), wherein at least one group D is present per molecule, and at least one group D has an NH2 group,

[0196] D f Si(OR 32 ) e R 31 d O (4-d-e-f) / 2 (3)

[0197] (In formula (3), R 31 , which may be the same as or different from each other, represent optionally substituted, nitrogen-free, monovalent SiC-bonded organic groups,

[0198] R 32 , which may be the same as or different from each other, represent a hydrogen atom or an optionally substituted hydrocarbon group,

[0199] D, which may be the same as or different from each other, represents a monovalent SiC-bonded group having at least one nitrogen atom which is not bonded to a carbonyl group (C═O),

[0200] d is 0 or 1,

[0201] e is 0, 1, 2, or 3,

[0202] f is 0 or 1, and

[0203] The sum of d, e and f is 4 or less).

[0204] Component (D) in the present invention may be any compound selected from silane (i.e., a compound represented by formula (3) where d+e+f=4) and siloxane (i.e., a compound comprising a unit represented by formula (3) where d+e+f≤3). Component (D) is preferably silane.

[0205] More preferably, component (D) in the present invention is a silane having at least one alkoxy group.

[0206] Examples of the group D include groups represented by the formulae: H2NCH2-, H2N(CH2)3-, H2N(CH2)2NH(CH2)3-, H2N(CH2)2NH(CH2)3NH(CH2)3-, H3CNH(CH2)3-, C2H5NH(CH2)3-, H2N(CH2)4-, H2N(CH2)5-, H(NHCH2CH2)2-(CH2)3-, C4H9NH(CH2)2NH(CH2)3-, cyclo-C6H 11 NH(CH2)3-, (CH3)2N(CH2)3- and (C2H5)2N(CH2)3-.

[0207] The group D is preferably a H2N(CH2)3-group, a H2N(CH2)2NH(CH2)3-group, a H3CNH(CH2)3-group, a C2H5NH(CH2)3-group, or a cyclo-C6H 11 NH(CH2)3-group, more preferably H2N(CH2)2NH(CH2)3-group, or cyclo-C6H 11 NH(CH2)3- group, particularly preferably H2N(CH2)2NH(CH2)3- group.

[0208] Examples of component (D) (i.e., the organosilicon compound) include 3-aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, 3-(2-aminoethyl)aminopropyldiethoxymethylsilane, 3-aminopropyldiethoxymethylsilane, ethoxy-terminated 3-aminopropyl(methyl)silsesquioxane (CAS No. 128446-60-6), hydroxy-terminated poly[3-(2-aminoethyl)aminopropyl]methylsiloxane (CAS No. 106214-80-6), and 3-(2-aminoethyl)aminopropylsiloxane-dimethylsiloxane copolymer (CAS No. 67923-07-3).

[0209] Component (D) is preferably 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyldiethoxymethylsilane, ethoxy-terminated 3-aminopropyl(methyl)silsesquioxane (CAS No. 128446-60-6), or 3-(2-aminoethyl)aminopropylsiloxane-dimethylsiloxane copolymer (CAS No. 67923-07-3). Component (D) is particularly preferably 3-(2-aminoethyl)aminopropyltrimethoxysilane, ethoxy-terminated 3-aminopropyl(methyl)silsesquioxane (CAS No. 128446-60-6), or 3-(2-aminoethyl)aminopropylsiloxane-dimethylsiloxane copolymer (CAS No. 67923-07-3).

[0210] The number of amino groups in component (D) is not particularly limited as long as the component contains at least one amino group. When component (D) contains two or more amino groups, the adhesion strength between the substrate and the coating tends to be further enhanced.

[0211] The content of component (D) in the crosslinkable composition according to the present invention may be 0.1 parts by mass or more and 2 parts by mass or less, preferably 0.1 parts by mass or more and 1.5 parts by mass or less, more preferably 0.1 parts by mass or more and 1.0 parts by mass or less, relative to 100 parts by mass of the total amount of components (A)-(I) and (A)-(II).

[0212] If the amount is not less than 0.1 parts by mass, the hydrolysis and condensation reaction of the crosslinkable composition (containing components (A)-(I) and (A)-(II)) can be accelerated. On the other hand, when the content is less than 0.1 parts by mass, the effect of catalyzing the hydrolysis and condensation reaction is reduced, and the adhesion is reduced. In addition, when component (D) is blended in an amount exceeding 2 parts by mass and the crosslinkable composition of the present invention is a moisture-curable composition, hydrolysis and condensation reactions may be carried out during the storage of the moisture-curable composition, and the storage stability may be deteriorated, for example, gelation and curing may occur during storage.

[0213] Component (D) used according to the invention, i.e. the organosilicon compound, is known and can be prepared by methods commonly used in chemistry. Commercially available component (D) can be purchased from WACKER Chemie AG, Munich, Germany under the trade names GENIOSIL (registered trademark) GF91, GENIOSIL (registered trademark) GF93, GENIOSIL (registered trademark) GF94, GENIOSIL (registered trademark) GF95, GENIOSIL (registered trademark) GF96, WACKER HAFTVERMITTLER AMS60 and WACKER HAFTVERMITTLER AMS70.

[0214] In addition to the above-mentioned components (A)-(I), (A)-(II), (B), (C) and (D), the crosslinkable composition according to the present invention may further contain any material conventionally used in compositions, which can be crosslinked by a condensation reaction. Examples of the material may include an organosiloxane as component (E), a filler as component (F), an organic solvent as component (G), a plasticizer as component (H), a catalyst as component (I) and a pigment as component (J).

[0215] Preferably, the crosslinkable composition according to the invention does not comprise any additional components besides components (A) to (I) to (J).

[0216] Component (E):

[0217] The component (E) which may be optionally blended is a component which contributes to the hardness enhancement of the coating layer.

[0218] Component (E) is an organosiloxane containing 2 to 30 units represented by the following formula (4): Component (E) contains at least one unit of formula (4) per molecule, wherein b is not zero.

[0219] R 6 a (R 7 O) b SiO (4-a-b) / 2 (4)

[0220] (In formula (4), R 6 , which may be the same as or different from each other, represent a monovalent SiC-bonded hydrocarbon group optionally substituted by a halogen atom or a Si-bonded halogen atom,

[0221] R 7 , which may be the same as or different from each other, represent an optionally substituted monovalent hydrocarbon group,

[0222] a is 0 or 1,

[0223] b is 0, 1, 2, or 3, and

[0224] a+b<4).

[0225] Component (E) used in the present invention is known and is commercially available, for example, under the name Wacker (registered trademark) TES40 from WACKER Chemie AG.

[0226] Examples of component (E) include:

[0227] (MeSiO 3 / 2 ) 0.37 (MeSi(OEt)O 2 / 2 )0.46 (MeSi(OEt)2O 1 / 2 ) 0.17 (wherein Mw = 2,400 g / mol, Mn = 900 g / mol, and Mw / Mn = 2.7),

[0228] (MeSiO 3 / 2 ) 0.38 (MeSi(OEt)O 2 / 2 ) 0.46 (MeSi(OEt)2O 1 / 2 ) 0.15 (Me2SiO 2 / 2 ) 0.01 (wherein Mw = 2,800 g / mol, Mn = 1,000 g / mol, and Mw / Mn = 2.8),

[0229] (MeSiO 3 / 2 ) 0.30 (MeSi(OMe)O 2 / 2 ) 0.47 (MeSi(OMe)2O 1 / 2 ) 0.23 (wherein Mw = 2,300 g / mol, Mn = 600 g / mol, Mw / Mn = 3.8),

[0230] (MeSiO 3 / 2 ) 0.32 (MeSi(OMe)O 2 / 2 ) 0.48 (MeSi(OMe)2O 1 / 2 ) 0.20 (where Mw = 3,300 g / mol, Mn = 900 g / mol, and Mw / Mn = 3.7)

[0231] (Si(OEt)2O 2 / 2 ) 0.42 (Si(OEt)O 3 / 2 ) 0.19 (Si(OEt)3O 1 / 2 ) 0.39 (wherein Mw = 1,000 g / mol, Mn = 800 g / mol, and Mw / Mn = 1.2)

[0232] (Si(OEt)2O 2 / 2 ) 0.48 (Si(OEt)O 3 / 2 ) 0.35 (Si(OEt)3O 1 / 2 ) 0.09 (SiO 4 / 2 ) 0.08(wherein Mw = 1,400 g / mol, Mn = 900 g / mol, and Mw / Mn = 1.6),

[0233] (iso-OctSi(OMe)O 2 / 2 ) 0.09 (iso-OctSiO 3 / 2 ) 0.06 (iso-OctSi(OMe)2O 1 / 2 ) 0.08 (MeSiO 3 / 2 ) 0.23 (MeSi(OMe)O 2 / 2 ) 0.35 (MeSi(OMe)2O 1 / 2 ) 0.19 (wherein Mw = 1,400 g / mol, Mn = 600 g / mol, and Mw / Mn = 2.3), and

[0234] (iso-OctSi(OMe)O 2 / 2 ) 0.12 (iso-OctSiO 3 / 2 ) 0.05 (iso-OctSi(OMe)2O 1 / 2 ) 0.08 (MeSiO 3 / 2 ) 0.22 (MeSi(OMe)O 2 / 2 ) 0.33 (MeSi(OMe)2O 1 / 2 ) 0.20 (wherein Mw=1,600 g / mol, Mn=700 g / mol, and Mw / Mn=2.3) In the formula, Me represents a methyl group, Et represents an ethyl group, and iso-Oct represents a 2,4,4-trimethylpentyl group.

[0235] Component (E) is preferably a group represented by formula (4) wherein R 6 is methyl (Me), R 7 is ethyl (Et), a is 0 or 1 and b is 1, 2 or 3. Examples thereof include:

[0236] (MeSiO 3 / 2 ) 0.37 (MeSi(OEt)O 2 / 2 ) 0.46 (MeSi(OEt)2O 1 / 2 ) 0.17 (wherein Mw = 2,400 g / mol, Mn = 900 g / mol, and Mw / Mn = 2.7)

[0237] (MeSiO 3 / 2 ) 0.38 (MeSi(OEt)O 2 / 2 ) 0.46 (MeSi(OEt)2O 1 / 2 ) 0.15 (Me2SiO 2 / 2 ) 0.01 (wherein Mw = 2,800 g / mol, Mn = 1,000 g / mol, and Mw / Mn = 2.8),

[0238] (MeSiO 3 / 2 ) 0.30 (MeSi(OMe)O 2 / 2 ) 0.47 (MeSi(OMe)2O 1 / 2 ) 0.23 (wherein Mw = 2,300 g / mol, Mn = 600 g / mol, and Mw / Mn = 3.8),

[0239] (MeSiO 3 / 2 ) 0.32 (MeSi(OMe)O 2 / 2 ) 0.48 (MeSi(OMe)2O 1 / 2 ) 0.20 (wherein Mw = 3,300 g / mol, Mn = 900 g / mol, and Mw / Mn = 3.7),

[0240] (Si(OEt)2O 2 / 2 ) 0.42 (Si(OEt)O 3 / 2 ) 0.19 (Si(OEt)3O 1 / 2 ) 0.39 (wherein Mw = 1,000 g / mol, Mn = 800 g / mol, and Mw / Mn = 1.2), and

[0241] (Si(OEt)2O 2 / 2 ) 0.48 (Si(OEt)O 3 / 2 ) 0.35 (Si(OEt)3O 1 / 2 ) 0.09 (SiO 4 / 2 ) 0.08 (wherein Mw=1,400 g / mol, Mn=900 g / mol, and Mw / Mn=1.6) Component (E) is particularly preferably a group represented by formula (4) wherein R 7 is Et and a is 0. Examples include:

[0242] (Si(OEt)2O 2 / 2 ) 0.42 (Si(OEt)O 3 / 2 ) 0.19 (Si(OEt)3O 1 / 2 ) 0.39 (wherein Mw = 1,000 g / mol, Mn = 800 g / mol, and Mw / Mn = 1.2), and

[0243] (Si(OEt)2O 2 / 2 ) 0.48 (Si(OEt)O 3 / 2 ) 0.35 (Si(OEt)3O 1 / 2 ) 0.09 (SiO 4 / 2 ) 0.08 (wherein Mw = 1,400 g / mol, Mn = 900 g / mol, and Mw / Mn = 1.6).

[0244] Component (E) has a weight-average molar mass Mw of preferably 500 to 10,000 g / mol, particularly preferably 500 to 8,000 g / mol.

[0245] Component (E) has a number average molar mass Mn of preferably 200 to 5,000 g / mol, particularly preferably 200 to 3,000 g / mol.

[0246] Component (E) has a polydispersity Mw / Mn of preferably 1 to 5, particularly preferably 1 to 4.

[0247] In the present invention, the weight-average molar mass Mw and the number-average molar mass Mn are determined according to DIN 1333: 1992-02, paragraph 4, by gel permeation chromatography (GPC) or size exclusion chromatography (SEC), according to DIN 55672-1, using polystyrene standards and a differential refractive index detector (RI detector), rounded to the nearest 100. Unless otherwise stated, THF is used as the eluent for phenyl-containing components and toluene is used as the eluent for phenyl-free components. The analysis is carried out at a column temperature of 45° C. The polydispersity is represented by the quotient Mw / Mn.

[0248] Component (E) is preferably liquid at 25° C. and 1,000 hPa.

[0249] The content of component (E) in the crosslinkable composition according to the present invention may be 0 parts by mass or more and 40 parts by mass or less, preferably 1 part by mass or more and 20 parts by mass or less, more preferably 4 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the total amount of components (A)-(I) and (A)-(II).

[0250] When component (E) is included within the above range, the viscosity of the crosslinkable composition can be made within a range suitable for applying the composition to a substrate, and workability is good.

[0251] The addition of component (C) can reduce the viscosity of the crosslinkable composition and obtain a coating having a smooth surface. In addition, the use of component (E) together to coexist therein can enhance the hardness of the coating while suppressing a significant increase in the viscosity of the crosslinkable composition.

[0252] Component (F):

[0253] Component (F) which may be optionally blended is a filler. Component (F) functions as an anti-sagging agent for the crosslinkable composition.

[0254] Examples of the optionally added component (F) include reinforcing fillers such as carbon black and silica. As the component (F), silica is preferred, and fumed silica is particularly preferred.

[0255] The component (F), ie, silicon dioxide, used according to the present invention may be surface-treated. In particular, the fumed silica used as component (F) is surface-modified with trimethylsiloxy groups.

[0256] In the case where the crosslinkable composition according to the present invention contains component (F), the content of component (F) may be 0 parts by mass or more and 30 parts by mass or less, preferably 5 parts by mass or more and 30 parts by mass or less, more preferably 8 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of the total amount of components (A)-(I) and (A)-(II). The crosslinkable composition according to the present invention preferably contains component (F).

[0257] Component (G):

[0258] Component (G) which may be optionally blended is an organic solvent.

[0259] Examples of optional component (G) include saturated hydrocarbons having 6 to 20 carbon atoms, which may be linear, branched or cyclic, such as a mixed hydrocarbon mixture of CAS No. 64742-47-8.

[0260] The optional component (G) is preferably a hydrocarbon mixture of saturated hydrocarbons having 6 to 20 carbon atoms selected from branched compounds and cyclic compounds.

[0261] Component (G) is preferably liquid at 25° C. and 1,000 hPa.

[0262] The solvent (G) preferably has an initial boiling point (IBP) (ASTM D86) within a temperature range of 90°C to 270°C and a dry point (DP) (ASTM D86) within a temperature range of 100°C to 310°C.

[0263] The optional solvent (G) has a molecular weight of 0.699 to 0.831 g / cm 3 Density at 15.6°C within the range (EN ISO 12185).

[0264] The optional solvent (G) preferably has a molecular weight of 0.5 mm 2 / s to 8mm 2 / s, particularly preferably 2mm 2 / s to 5mm 2 / s kinematic viscosity at 40°C (ASTM D445).

[0265] In the case where the crosslinkable composition according to the present invention contains component (G), the content of component (G) may be 0 parts by mass or more and 40 parts by mass or less, preferably 5 parts by mass or more and 30 parts by mass or less, more preferably 10 parts by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the total amount of components (A)-(I) and (A)-(II). The crosslinkable composition according to the present invention preferably contains component (G).

[0266] Component (H):

[0267] Component (H) which may be optionally blended is a plasticizer.

[0268] The optional component (H) is preferably a diorganopolysiloxane whose terminals are blocked with triorganosiloxy groups, and particularly preferably a dimethylpolysiloxane whose terminals are blocked with trimethylsiloxy groups.

[0269] Component (H) is preferably liquid at 25° C. and 1,000 hPa.

[0270] Specifically, component (H) is a dimethylpolysiloxane whose terminals are blocked with trimethylsiloxy groups and which is liquid at 25° C. and 1,000 hPa.

[0271] Component (H) preferably has a viscosity at 25° C. of 5 to 1000 mPa·s, particularly preferably 35 to 100 mPa·s.

[0272] In the case where the crosslinkable composition according to the present invention contains component (H), the content of component (H) may be 0 parts by mass or more and 20 parts by mass or less, preferably 5 parts by mass or more and 20 parts by mass or less, more preferably 5 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the total amount of components (A) to (I) and (A) to (II).

[0273] Component (I):

[0274] Component (I) which may be optionally blended is a catalyst.

[0275] The optional component (I), ie the optional catalyst, is any compound conventionally used in moisture curing systems. Examples of such catalysts include diorganotin compounds, titanium alkoxides, titanium chelates, zinc 2-ethylhexanoate and bismuth (III) 2-ethylhexanoate.

[0276] It is preferred that the crosslinkable composition according to the invention preferably does not contain any metal-containing catalyst (I). Furthermore, it is particularly preferred that the crosslinkable composition according to the invention does not contain any catalyst (I).

[0277] Component (J):

[0278] Component (J) which may be optionally blended is a pigment.

[0279] Examples of optional component (J) include inorganic pigments such as titanium dioxide and yellow, red and black iron oxide pigments.

[0280] In the case where the crosslinkable composition according to the present invention contains component (J), the content of component (J) may be 0 parts by mass or more and 2 parts by mass or less, preferably 0.5 parts by mass or more and 2.0 parts by mass or less, relative to 100 parts by mass of the total amount of components (A) to (I) and (A) to (II).

[0281] The viscosity of the crosslinkable composition as a final product containing components (A)-(I) to (D) and optional components as required is not particularly limited, and is preferably, for example, in the range of 1,000 mPa·s or more to 5,000 mPa·s or less. When the viscosity falls within the above range, the workability when the crosslinkable composition is applied to a substrate is good, and a smooth coating can be obtained after the crosslinkable composition is cured.

[0282] The present invention also provides a crosslinkable composition comprising: relative to 100 parts by mass of the total amount of components (A)-(I) and (A)-(II),

[0283] 5 parts by mass or more and 20 parts by mass or less of component (B),

[0284] 10 parts by mass or more and 200 parts by mass or less of component (C),

[0285] 0.1 parts by mass or more and 2 parts by mass or less of component (D),

[0286] Optionally, component (E) in an amount of 0 parts by mass or more and 40 parts by mass or less,

[0287] Optionally, component (F) in an amount of 0 parts by mass or more and 30 parts by mass or less, and

[0288] Optionally, component (G), ie, an organic solvent, is in an amount of 0 parts by mass or more and 40 parts by mass or less.

[0289] The crosslinkable composition of the present invention is a moisture-curable composition and may be a multi-component composition, such as a two or more component composition, or may be a one-component composition. When the crosslinkable composition is used as a moisture-curable coating agent for obtaining a coating by applying the composition to a substrate, the crosslinkable composition is particularly preferably a one-component composition that does not require mixing work during application.

[0290] The method for producing the crosslinkable composition of the present invention for use as a one-component moisture-curable coating agent is not particularly limited, and the crosslinkable composition can be produced by mixing the respective components in any order.

[0291] Furthermore, the method for producing the crosslinkable composition of the present invention preferably comprises:

[0292] a first mixing step of blending components (A)-(I) into a mixture of components (A)-(II) and component (B);

[0293] a second mixing step of blending component (C) into the mixture obtained in the first mixing step; and

[0294] A third mixing step of blending component (D) into the mixture obtained in the second mixing step.

[0295] First Mixing Step:

[0296] Components (A) to (II) used in the first mixing step of the above method for producing a crosslinkable composition can be obtained by a known method of mixing a diorganopolysiloxane having a silanol group at each end of the molecular chain with an excess of component (B) and causing a dealcoholization reaction.

[0297] In the first mixing step, components (A)-(I) are introduced into a mixture of unreacted component (B) and components (A)-(II) obtained as described above and mixed. The temperature during mixing is not particularly limited, and it may be 0° C. or higher and 80° C. or lower, preferably 20° C. or higher and 50° C. or lower.

[0298] In case the crosslinkable composition contains filler (F), filler (F) can be blended with components (A)-(II) in the first mixing step. When filler (F) is contained, it is preferred to mix by a mixing method applying high shear force, for example using a dissolver mixer or the like.

[0299] If component (F) is introduced before the other liquid components ((A)-(I), (B), (C), (D), etc.), the viscosity of the mixture increases and shearing force is easily applied. Thus, the dispersibility of component (F) in the crosslinkable composition is improved.

[0300] When component (F) is contained, in order to obtain good dispersibility, the viscosity of the mixture after mixing component (F), that is, the mixture of components (A)-(I), components (A)-(II), component (B) and component (F) is preferably 10,000 mPa·s or more and 100,000 mPa·s or less, more preferably 2,000 mPa·s or more and 50,000 mPa·s or less.

[0301] Second Mixing Step:

[0302] The second mixing step in the above-mentioned method for producing a crosslinkable composition is a step of introducing and mixing component (C) into the mixture obtained in the first mixing step. The temperature during mixing is not particularly limited, and it may be 0° C. or higher and 80° C. or lower, preferably 20° C. or higher and 50° C. or lower.

[0303] In case the crosslinkable composition comprises component (E), component (E) may be blended together with component (C) in a second mixing step.

[0304] Third Mixing Step:

[0305] The third mixing step in the above-mentioned method for producing a crosslinkable composition is a step of introducing and mixing component (D) into the mixture obtained in the second mixing step. The temperature during mixing is not particularly limited, and it may be 0°C or higher and 80°C or lower, preferably 20°C or higher and 50°C or lower. If the mixture is placed in an environment containing moisture, a crosslinking reaction is performed after the component (D) is blended. Therefore, after the component (D) is introduced in the third mixing step, the mixture is preferably stored in a nitrogen atmosphere or under reduced pressure.

[0306] The crosslinkable composition of the present invention has storage stability in the temperature range of 20° C. or higher and 40° C. or lower in the absence of water, and the crosslinkable composition undergoes a crosslinking reaction when in contact with water.

[0307] The present invention further provides a method for producing a coating, comprising:

[0308] an application step of applying the crosslinkable composition described above to a substrate; and

[0309] A curing step of moisture-curing the crosslinkable composition applied in the applying step.

[0310] Specific examples of the application method in the applying step include an application method to a substrate surface by a generally and conventionally known application method such as painting, blowing, blade coating, roller coating, spraying, brushing, pouring, knife coating, dipping or roller coating.

[0311] In the method of the present invention, the amount of crosslinkable composition applied is 50 g or more and 400 g or less, preferably 70 g or more and 200 g or less per square meter of substrate surface area. For smooth substrates such as metal substrates, the amount applied may be 50 g or more and 200 g or less, and for porous substrates such as wood, the amount applied may be 100 g or more and 400 g or less.

[0312] The substrate to which the crosslinkable composition is applied is not particularly limited, and examples of the substrate include cement-based materials, gypsum board, asphalt, wood, metal, resin, tile, glass, natural stone, artificial stone, and combinations thereof.

[0313] These substrates may be pre-treated with a primer.

[0314] Examples of the metal used as the substrate include iron, aluminum, titanium, copper, and alloys containing these. The metal may be processed by electrodeposition coating or the like.

[0315] Examples of the metal oxide used as the substrate include silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, and a mixture of these metal oxides.

[0316] Examples of cement-based materials used as the substrate include concrete, mortar, siding, ALC (lightweight aerated concrete), stone board, calcium silicate board, and wood cement board.

[0317] Examples of wood used as a substrate include solid natural wood and wood products such as particleboard made of wood, boards made of wood chips, plywood, laminates, and veneers. Examples of solid natural wood include fir, spruce, alder, beech, pine, oak, poplar, basswood, willow, maple, cedar, birch, rubber tree, cherry, larch, juniper, yew, black locust, elm, walnut, mahogany, rosewood, teak, Borneo teak, cedar and olive, but are not limited thereto.

[0318] As the resin used as the base, for example, the type is not particularly limited, and examples of the resin include synthetic resins such as acrylic resins, acrylic urethane resins, acrylic silicone resins, polyurethane resins, alkyd resins, amino resins, unsaturated polyester resins, epoxy resins, vinyl butyral resins, and vinyl chloride resins.

[0319] The coating obtained by curing the crosslinkable composition of the present invention has a suitable hardness (e.g., a Shore A hardness of 30 or more and 60 or less). Here, although the coating has hardness, it also has flexibility. Therefore, a coating that is advantageously adhered to a stretchable material such as wood and hardly cracks or peels off after curing can be obtained.

[0320] The crosslinkable composition may be further applied (overcoated) to the surface of the coating obtained by applying and curing the crosslinkable composition on the substrate surface by the above method before curing. That is, when cracks, chips, scratches, etc. occur in the coating due to aging degradation, physical impact, etc., the coating can be repaired by applying the crosslinkable composition.

[0321] The surface of the coating has good paintability, and even when the crosslinkable composition is overcoated on the surface of the coating, overcoating can be performed without causing shrinkage cavities. The crosslinkable composition after overcoating forms a cured product having the same chemical composition as the coating before overcoating by wet curing. Therefore, the new coating adheres well to the previous coating before overcoating and is less likely to be peeled off by high-pressure washing water or the like. Therefore, the new coating obtained after overcoating can also show good re-paintability and re-removability while maintaining its hardness.

[0322] The crosslinkable composition may contain any one or two or more selected from octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), tetradecamethylcycloheptasiloxane (D7) and hexadecamethylcyclooctasiloxane (D8).

[0323] The total content of (D4), (D5), (D6), (D7) and (D8) may be less than 0.1 parts by mass (ie, less than 1,000 ppm) relative to 100 parts by mass of the total amount of the crosslinkable composition.

[0324] When the total content of (D4) to (D8) contained in the crosslinkable composition falls within the above range, the flash point of the entire composition can be increased, and safety during storage can be improved.

[0325] A crosslinkable composition containing less than 0.1 parts by mass of (D4) to (D8) in terms of the total content of (D4) to (D8) relative to 100 parts by mass of the total amount of the crosslinkable composition can be produced by using components (A)-(I) and (A)-(II) wherein the total content xA of (D4) to (D8) is less than 0.1 parts by mass, component (B) wherein the total content xB of (D4) to (D8) is less than 0.1 parts by mass, and component (C) wherein the total content xC of (D4) to (D8) is less than 0.1 parts by mass, such that the total content Xa+xB+xC is less than 0.1 parts by mass.

[0326] The content of each of (D4) to (D8) is measured by gas chromatography. The measurement conditions of the gas chromatography can be appropriately selected according to a conventionally known method.

[0327] As a method for reducing the content of (D4) to (D8) in the crosslinkable composition, a method of subjecting each component to a heat treatment under reduced pressure is well known. For example, it is preferred that a heat treatment under reduced pressure is performed at 180° C. and 20 mmHg for about 8 hours during the production of each or all of the raw materials for components (A)-(I) to (D).

[0328] The crosslinkable composition of the present invention may contain optional components other than the above components as long as the objects of the present invention are achieved. For example, any other materials such as defoamers, curing rate regulators, additives, etc. may be contained.

[0329] The present invention further provides a crosslinkable composition, characterized in that the crosslinkable composition comprises the above-mentioned components (A)-(I), (A)-(II), (B), (C) and (D), and blending 10 parts by mass or more and 200 parts by mass or less of component (C) relative to 100 parts by mass of the total amount of components (A)-(I) and (A)-(II) improves the re-paintability of the cured product of the crosslinkable composition and enhances the hardness.

[0330] The repaintability of the cured products described herein can be evaluated by the following evaluation method.

[0331] Repeat paintability evaluation method:

[0332] On the surface of the coating obtained by curing the crosslinkable composition of the present invention, acrylic spray paint (brown) manufactured by Nippon Paint Co., Ltd. was sprayed in an area of ​​30 cm×20 cm from 30 cm above the coating surface (before drying, the application amount was 100 g / m 2 ). After standing for 2 hours, the paint was removed by spraying water on the paint at a distance of 10 cm from the coating surface using a household high-pressure cleaner. These processes were repeated 10 times to obtain surface evaluation test pieces for repeated paintability evaluation.

[0333] On the surface evaluation test piece for repeated paintability evaluation, acrylic spray paint (brown) manufactured by Nippon Paint Co., Ltd. was sprayed in an area of ​​30 cm×20 cm from 30 cm above the coating surface, and the presence or absence of shrinkage cavities was visually checked.

[0334] The present invention also provides a laminate, which includes a substrate and a coating obtained by curing the above-mentioned crosslinkable composition. The laminate has a coating with excellent repeatability and removability on the surface. Therefore, the laminate can be used as a plate for expected reuse. For example, this plate is painted on the surface, and after observing the paint for a period of time, it is removed with high-pressure washing water and replaced with another paint. The laminate can be used for example to be installed in the outer surface of a steel plate, a guardrail, a vehicle (such as a packaged advertising vehicle) at a construction site or an outdoor gathering place, an advertising sign, a viaduct pier surface, the outer wall of a public structure, etc.

[0335] The hardness of the cured product can be evaluated by measuring the Shore A hardness with a type A durometer based on the method defined in JIS K 6253.

[0336] Example

[0337] The present invention will be specifically described based on Examples and Comparative Examples and respective blending amounts and evaluation results of components in Tables 1 and 2, but the present invention is not limited to the following Examples.

[0338] Method for preparing evaluation test pieces:

[0339] The crosslinkable composition obtained by mixing the respective components shown in Tables 1 and 2 was applied to a slate substrate in an amount of 100 g per square meter of substrate surface area with a roller. Then, the applied substrate was allowed to stand for 7 days under the conditions of a temperature of 23° C. and a humidity of 50%. The cured product (coating) thus obtained was used as a test piece for evaluating paintability, repeated paintability, paint retention, repeated paint retention, removability, repeated removability, and smoothness.

[0340] Processability evaluation method:

[0341] The viscosity of the crosslinkable composition before curing was measured using a rotational viscometer under a temperature condition of 25° C. In this measurement, if the viscosity was 1,000 mPa·s or more and 5,000 mPa·s or less, the workability was evaluated as good.

[0342] Paintability evaluation method:

[0343] On the surface of the evaluation test piece, acrylic spray paint (brown) manufactured by Nippon Paint Co., Ltd. was sprayed in an area of ​​30 cm×20 cm from 30 cm above the coating surface, and the presence or absence of shrinkage cavities was visually checked.

[0344] In the following evaluation criteria, A or B was evaluated as good paintability.

[0345] A: No visible shrinkage cavities

[0346] B: more than 0 and less than 10 shrinkage holes (where φ<2mm) / m 2 And there is no shrinkage cavity of φ≥2mm

[0347] C: 10 or more shrinkage holes (φ<2mm) / m 2 , more than 0 and less than 10 shrinkage holes (2mm≤φ<5mm) / m 2 , and there is no shrinkage cavity of φ≥5mm

[0348] D: 10 or more shrinkage holes (2mm≤φ<5mm) / m 2 , and there is no shrinkage cavity of φ≥5mm

[0349] E: There are shrinkage holes with a diameter of φ≥5mm

[0350] Repeat paintability evaluation method:

[0351] On the surface of the evaluation test piece, acrylic spray paint (brown) manufactured by Nippon Paint Co., Ltd. was sprayed in an area of ​​30 cm×20 cm from 30 cm above the coating surface (before drying, the application amount was 100 g / m 2 ). After standing for 2 hours, the paint was removed by spraying the paint at a distance of 10 cm from the surface of the evaluation test piece using a household high-pressure cleaner. These processes were repeated 10 times to obtain a surface evaluation test piece for repeated paintability evaluation.

[0352] On the surface evaluation test piece for repeated paintability evaluation, acrylic spray paint (brown) manufactured by Nippon Paint Co., Ltd. was sprayed in an area of ​​30 cm×20 cm from 30 cm above the coating surface, and the presence or absence of shrinkage cavities was visually checked.

[0353] In the following evaluation criteria, A or B was evaluated as good repaintability.

[0354] A: No visible shrinkage cavities

[0355] B: more than 0 and less than 10 shrinkage holes (where φ<2mm) / m 2 And there is no shrinkage cavity of φ≥2mm

[0356] C: 10 or more shrinkage holes (φ<2mm) / m 2 , more than 0 and less than 10 shrinkage holes (2mm≤φ<5mm) / m 2 , and there is no shrinkage cavity of φ≥5mm

[0357] D: 10 or more shrinkage holes (2mm≤φ<5mm) / m 2 , and there is no shrinkage cavity of φ≥5mm

[0358] E: There are shrinkage holes with a diameter of φ≥5mm

[0359] Evaluation method for paint retention:

[0360] At 25°C, at 0.1kgf / cm 2 The evaluation test piece was sprayed with water from a height of 30 cm for 30 minutes under the conditions of . After the test piece was allowed to stand for 2 hours and dried, the surface of the test piece was visually inspected. In the following evaluation criteria, A or B was evaluated as good paint retention.

[0361] A: No visible peeling

[0362] B: No visible peeling, but some cracks

[0363] C: Visible peeling, peeling area less than 5%

[0364] D: 5% or more and less than 30% of the peeling area

[0365] E: 30% or more peeling area

[0366] Repeated painting retention evaluation method:

[0367] At 25°C, at 0.1kgf / cm 2 The surface of the evaluation test piece was sprayed with water from a height of 30 cm for 30 minutes under the conditions of , and then the test piece was allowed to stand for 2 hours and dried. After repeating these processes 10 times, the surface of the test piece was visually inspected. In the following evaluation criteria, A or B was evaluated as good repeated painting retention.

[0368] A: No visible peeling

[0369] B: No visible peeling, but some cracks

[0370] C: Visible peeling, peeling area greater than 0% and less than 5%

[0371] D: 5% or more and less than 30% of the peeling area

[0372] E: 30% or more peeling area

[0373] Removability evaluation method:

[0374] On the surface of the evaluation test piece, acrylic spray paint (brown) manufactured by Nippon Paint Co., Ltd. was sprayed in an area of ​​30 cm×20 cm from 30 cm above the coating surface (before drying, the application amount was 100 g / m 2 ), and then the test piece was allowed to stand for 2 hours. Afterwards, the paint was removed by spraying water on the paint at a distance of 10 cm from the surface using a high-pressure cleaner at a pump pressure of 100 bar, and the degree of removal (residual paint of acrylic lacquer) was visually evaluated. In the following evaluation criteria, A or B was evaluated as good removability.

[0375] A: No paint residue

[0376] B: Residual paint greater than 0% and 5% or less

[0377] C: More than 5% and 10% or less residual paint

[0378] D: Residual paint greater than 10% and less than 30%

[0379] E: 30% or more of residual paint

[0380] Repeatability evaluation method:

[0381] On the surface of the evaluation test piece, acrylic spray paint (brown) manufactured by Nippon Paint Co., Ltd. was sprayed in an area of ​​30 cm×20 cm from 30 cm above the coating surface (before drying, the application amount was 100 g / m 2 ), and then the test piece was allowed to stand for 2 hours. Afterwards, the paint was removed by spraying water on the paint at a distance of 10 cm from the surface using a high-pressure cleaner under a pump pressure of 100 bar. These processes were repeated 10 times. Then, the above-mentioned acrylic paint spray was sprayed on the surface of the evaluation test piece, and the paint was removed by spraying water on the paint at a distance of 10 cm from the surface using a high-pressure cleaner with a pump pressure of 100 bar. Then, the degree of removal (residual paint of the paint) was visually evaluated. In the following evaluation criteria, A or B was evaluated as good reproducibility.

[0382] A: No paint residue

[0383] B: Residual paint greater than 0% and 5% or less

[0384] C: More than 5% and 10% or less residual paint

[0385] D: Residual paint greater than 10% and less than 30%

[0386] E: 30% or more of residual paint

[0387] Smoothness evaluation method:

[0388] The surface of the test piece was evaluated by visual inspection. In the following evaluation criteria, A or B was evaluated as good smoothness.

[0389] A: Almost no uneven paint

[0390] B: Some paint is uneven

[0391] C: A lot of uneven paint

[0392] Evaluation method of dry-to-touch time:

[0393] The film was touched with a finger 30 minutes after film formation, every hour from 1 hour to 7 hours, and after 24 hours. When it was felt that the film did not stick to the finger at the specified time, it was determined that the dry to touch condition had been reached, and this time was taken as the dry to touch time.

[0394] Evaluation method for hardness of test piece:

[0395] The Shore A hardness of the cured product of a 5 mm thick sheet was measured in accordance with JIS K 6249.

[0396] Embodiment 1:

[0397] A fumed silica filler as component (F) is added to a mixture of a linear polydimethylsiloxane having a viscosity of 5,240 mPa·s at 25° C. and containing (N,N-di-n-butylaminotriethoxy)diethoxysilyl groups at both ends as components (A) to (II) and (N,N-di-n-butylaminotriethoxy)triethoxysilane as component (B).

[0398] Note that components (A)-(II) comprise a mixture of two components, one having a viscosity of 6,000 mPa·s at 25° C. and the other having a viscosity of 2,000 mPa·s at 25° C., having different numbers of dimethylsiloxy units in a mass ratio of 53.0:40:9.

[0399] To the resulting mixture was added a linear polydimethylsiloxane having a viscosity of 100 mPa·s and containing trimethylsilyl groups at both ends as components (A) to (I). The mixture was stirred at 25° C. at a stirring speed of 400 rpm for 10 minutes.

[0400] Then, tetraethoxysilane as component (C), tetraethoxysilane oligomeric hydrolyzate as component (E) and isoparaffin solvent as component (G) were added to the mixture, and the resulting mixture was stirred at 25° C. at a stirring speed of 400 rpm for 5 minutes.

[0401] Finally, 3-(2-aminoethyl)aminopropyltrimethoxysilane was added as component (D), and the mixture was stirred at 400 rpm for 5 minutes at 25° C. The mixture was then stirred for another 25 minutes at a pressure of 100 hPa for degassing to obtain a crosslinkable composition according to Example 1.

[0402] Here, the fumed silica filler is fumed silica commercially available from WACKER Chemie AG as HDK (registered trademark) H2000. The fumed silica has a carbon content of 2.3 to 3.2% by weight (according to DIN ISO 10694) and a tap density of 100 to 250 g / l (according to DIN EN ISO 787011), and has been surface-modified with trimethylsiloxy groups. Before the surface treatment, the BET surface area of ​​the fumed silica is 190 to 210 m 2 / g.

[0403] Tetraethoxysilane oligomeric hydrolysate is commercially available from WACKER Chemie AG as WACKER (registered trademark) TES40 and has a carbon content of 1.06 to 1.07 g / cm at 20°C. 3 Density (DIN51757), flash point of 62°C (DIN 51755) and SiO2 content of about 41%.

[0404] The isoparaffin solvent is an organic solvent commercially available as ISOPAR (registered trademark) M from ExxonMobil Chemical.

[0405] The obtained crosslinkable composition had a low viscosity of 3,200 mPa·s and good processability, and the coating obtained after curing showed good smoothness.

[0406] The results for paintability and repaintability were also very good. The repaintability was also good, and the removability and removability were also very good. The Shore A hardness of the coating was 52, which was adequate.

[0407] Embodiment 2:

[0408] A crosslinkable composition according to Example 2 was obtained in the same manner as in Example 1 except that the tetraethoxysilane oligomeric hydrolyzate as component (E) was not mixed.

[0409] The viscosity of the obtained crosslinkable composition was slightly higher than that in Example 1. However, the coating obtained after curing showed good smoothness. Although the Shore A hardness of the coating was lower than that in Example 1, it was within the range of sufficient hardness.

[0410] Embodiment 3:

[0411] A crosslinkable composition according to Example 3 was obtained in the same manner as in Example 1, except that methyltriethoxysilane was used as component (C) instead of tetraethoxysilane.

[0412] The evaluation results are almost the same as those of Example 1, but the Shore A hardness of the coating is lower than that of Example 1.

[0413] Embodiment 4:

[0414] A crosslinkable composition according to Example 4 was obtained in the same manner as in Example 1, except that tetramethoxysilane was used as component (C) instead of tetraethoxysilane.

[0415] The evaluation results were as good as those of Example 1.

[0416] Embodiment 5:

[0417] A crosslinkable composition according to Example 5 was obtained in the same manner as in Example 1, except that methyltrimethoxysilane was used as component (C) instead of tetraethoxysilane.

[0418] The evaluation results are almost the same as those of Example 1, but the Shore A hardness of the coating is lower than that of Example 1.

[0419] Based on the results of Examples 1, 3 and 5, it was confirmed that adding a component having four alkoxy groups bonded to a silicon atom (4-functional silane) as component (C) can improve the hardness of the coating more than adding a component having three alkoxy groups bonded to a silicon atom (3-functional silane).

[0420] Embodiment 6:

[0421] A crosslinkable composition according to Example 6 was obtained in the same manner as in Example 1, except that the amount of tetraethoxysilane used as component (C) was reduced to about half of that in Example 1, and SILRES MSE 100 manufactured by WACKERChemie AG, which is an oligomer of methyltrimethoxysilane, was further added as component (E).

[0422] Paintability, repaintability and paint retention were slightly inferior to those of Example 1. This is believed to be due to the poor compatibility of SILRES MSE 100 with the other components in the composition. On the other hand, with regard to removability and removability, favorable results like those in Example 1 were obtained.

[0423] Embodiment 7:

[0424] A crosslinkable composition according to Example 7 was obtained in the same manner as in Example 1, except that aminopropyltrimethoxysilane was used as component (D) instead of 3-(2-aminoethyl)aminopropyltrimethoxysilane.

[0425] The same good results as in Example 1 were obtained, except that the viscosity of the crosslinkable composition increased slightly.

[0426] Embodiment 8:

[0427] A crosslinkable composition according to Example 8 was obtained in the same manner as in Example 1, except that phenyltriethoxysilane was blended as component (C) instead of tetraethoxysilane.

[0428] The removability and repeated removability decreased slightly but were within the permissible range.

[0429] Comparative Example 1:

[0430] A crosslinkable composition according to Comparative Example 1 was obtained in the same manner as in Example 1, except that the components corresponding to the component (C) and the component (E) were not blended.

[0431] Since component (C) is not included, the viscosity of the crosslinkable composition is high and the processability is poor. In addition, it is observed that the coating obtained is highly non-uniform, resulting in poor smoothness.

[0432] The paintability was very poor, and this was considered to be due to a large amount of components (A)-(I) seeping out to the surface and causing the paint to repel. After removing the paint 10 times, the repeated paintability improved slightly, but the result was not satisfactory. It is believed that although the paintability was improved from the initial stage due to the reduction of components (A)-(I) on the surface by removing the paint multiple times, the result was still not satisfactory.

[0433] The results of paint retention and repeated paint retention were also poor. The hardness of the coating was also insufficient.

[0434] On the other hand, removability and repeated removability are good.

[0435] Comparative Example 2:

[0436] A crosslinkable composition according to Comparative Example 2 was obtained in the same manner as in Example 1, except that the component corresponding to component (C) was not blended, but component (E) was blended.

[0437] Compared with the results of Comparative Example 1, the processability, paintability, repeated paintability, paint retention, repeated paint retention and hardness of the coating were slightly improved. This is considered to be the effect of blending component (E). However, these evaluation results are not satisfactory.

[0438] Comparative Example 3:

[0439] A crosslinkable composition according to Comparative Example 3 was obtained in the same manner as in Example 1, except that the component corresponding to component (C) was not blended and methyltrimethoxysilane oligomer SILRES MSE 100 manufactured by WACKER Chemie AG was blended as component (E) instead of tetraethoxysilane oligomeric hydrolyzate.

[0440] Due to the high viscosity of the crosslinkable composition, the smoothness of the obtained coatings was poor. In addition, the removability and repeated removability were poor.

[0441] Comparative Example 4:

[0442] A crosslinkable composition according to Comparative Example 4 was obtained in the same manner as in Example 1, except that isooctyltriethoxysilane was blended as component (C) instead of tetraethoxysilane.

[0443] The obtained coating was very soft and lacked hardness, and the paint retention was slightly reduced. It is assumed that the organic group (isooctyl group) of isooctyltriethoxysilane is bulky, which causes steric hindrance and reduces the crosslinking density.

[0444] In each of Examples 1 to 8 and Comparative Examples 1 to 4, the dry-to-touch time was 2 hours or more and 3 hours or less.

[0445] Furthermore, in Examples 1 to 7, the total content of octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), tetradecamethylcycloheptasiloxane (D7) and hexadecamethylcyclooctasiloxane (D8) is less than 0.3 parts by mass relative to 100 parts by mass of the entire crosslinkable composition.

[0446]

[0447] Some or all of the above embodiments may be described as the following appendices, but are not limited to the following description. Each appendix may also be combined with each claim recorded in the claims section.

[0448] (Appendix 1)

[0449] A crosslinkable composition comprising:

[0450] Components (A) to (I) are diorganopolysiloxanes having a linear or branched structure, the molecular chain ends of which are capped with triorganosilyl groups;

[0451] Components (A)-(II) having at least two (R 2 R 3 NCH2) groups and at least four (OR 4 ) group of straight chain or branched structure of diorganopolysiloxane

[0452] (R 2 represents a hydrogen atom or an optionally substituted monovalent straight or branched hydrocarbon group having 1 to 6 carbon atoms,

[0453] R 3 is an optionally substituted monovalent straight or branched hydrocarbon group having 1 to 6 carbon atoms, a cyclic saturated hydrocarbon group having 5 or 6 carbon atoms, or a phenyl group, and

[0454] R 4 , which may be the same as or different from each other, and each represents an optionally substituted monovalent hydrocarbon group);

[0455] Component (B), which is a silane represented by the following formula (1) and / or a partial hydrolyzate thereof,

[0456] (R 2 R 3 NCH2)Si(OR 4 )3(1);

[0457] Component (C), which is an alkoxysilane represented by the following formula (2),

[0458] R 21 4-x Si(OR 22 ) x (2)

[0459] (In formula (2), R 21 , which may be the same as or different from each other, represent an optionally substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and

[0460] R 22, which may be the same as or different from each other, each representing an optionally substituted monovalent hydrocarbon group having 1 to 5 carbon atoms, wherein x is 2, 3 or 4); and

[0461] Component (D), which is an organosilicon compound comprising a unit represented by the following formula (3), wherein at least one group D is present per molecule, and at least one group D has an NH2 group,

[0462] D f Si(OR 32 ) e R 31 d O (4-d-e-f) / 2 (3)

[0463] (In formula (3), R 31 , which may be the same as or different from each other, represent optionally substituted, nitrogen-free, monovalent SiC-bonded organic groups,

[0464] R 32 , which may be the same as or different from each other, represent a hydrogen atom or an optionally substituted hydrocarbon group,

[0465] D, which may be the same as or different from each other, represents a monovalent SiC-bonded group having at least one nitrogen atom which is not bonded to a carbonyl group (C═O),

[0466] d is 0 or 1,

[0467] e is 0, 1, 2, or 3,

[0468] f is 0 or 1, and

[0469] The sum of d, e and f is 4 or less).

[0470] Addendum 2:

[0471] The crosslinkable composition according to Appendix 1 further comprises:

[0472] Component (E) which is an organosiloxane containing 2 to 30 units represented by the following formula (4) per molecule and containing at least one unit of formula (4) in which b is not 0:

[0473] R 6 a (R 7 O) b SiO (4-a-b) / 2 (4)

[0474] (In formula (4), R 6 , which may be the same as or different from each other, represent a monovalent SiC-bonded hydrocarbon group optionally substituted by a halogen atom or a Si-bonded halogen atom,

[0475] R 7 , which may be the same as or different from each other, represent an optionally substituted monovalent hydrocarbon group,

[0476] a is 0 or 1,

[0477] b is 0, 1, 2, or 3, and

[0478] a+b<4).

[0479] Addendum 3:

[0480] The crosslinkable composition according to Appendix 1 or 2, wherein the group R in the component (C) 22 It is ethoxy.

[0481] Addendum 4:

[0482] The crosslinkable composition according to any one of Appendixes 1 to 3, wherein the groups (R 2 R 3 NCH2) is one selected from N,N-dimethylaminomethyl, N,N-diethylaminomethyl, N,N-di-n-propylaminomethyl and N,N-di-n-butylaminomethyl.

[0483] Addendum 5:

[0484] The crosslinkable composition according to any one of Appendices 1 to 4, further comprising component (F) as a filler.

[0485] Addendum 6:

[0486] The crosslinkable composition according to any one of Appendices 1 to 5, comprising: relative to 100 parts by mass of the total amount of components (A)-(I) and (A)-(II),

[0487] 5 parts by mass or more and 20 parts by mass or less of component (B),

[0488] 10 parts by mass or more and 200 parts by mass or less of component (C),

[0489] 0.1 parts by mass or more and 2 parts by mass or less of component (D),

[0490] Optionally, component (E) in an amount of 0 parts by mass or more and 40 parts by mass or less,

[0491] Optionally, component (F) in an amount of 0 parts by mass or more and 30 parts by mass or less, and

[0492] Optionally, component (G), ie, an organic solvent, is in an amount of 0 parts by mass or more and 40 parts by mass or less.

[0493] Addendum 7:

[0494] A one-component moisture-curable coating agent comprising the crosslinkable composition according to any one of Appendices 1 to 6.

[0495] Addendum 8:

[0496] A method for preparing a crosslinkable composition according to any one of Appendices 1 to 6, comprising:

[0497] a first mixing step of blending components (A)-(I) into a mixture of components (A)-(II) and component (B);

[0498] a second mixing step of blending component (C) into the mixture obtained in the first mixing step; and

[0499] A third mixing step of blending component (D) into the mixture obtained in the second mixing step.

[0500] Addendum 9:

[0501] A method for preparing a coating, comprising:

[0502] An application step of applying a crosslinkable composition according to any one of Appendices 1 to 6 to a substrate; and

[0503] A curing step of moisture-curing the crosslinkable composition applied in the applying step.

[0504] Addendum 10:

[0505] The method according to Appendix 9, wherein the crosslinkable composition is used in an amount of 50 g or more and 400 g or less per square meter of substrate surface area.

[0506] Addendum 11:

[0507] A method for repairing a coating, wherein the coating is a cured product of a crosslinkable composition according to any one of Appendices 1 to 6, the method comprising applying the crosslinkable composition according to any one of Appendices 1 to 6 on the surface of the coating.

[0508] Addendum 12:

[0509] The method according to any one of Appendices 9 and 10, wherein the substrate is one selected from cement-based materials, gypsum board, asphalt, wood, metal, resin, tile, glass, natural stone, artificial stone and combinations thereof.

[0510] Addendum 13:

[0511] A crosslinkable composition comprising components (A)-(I), components (A)-(II), component (B), component (C) and component (D), wherein

[0512] Component (C) is blended in an amount of 10 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the total amount of components (A)-(I) and (A)-(II) to improve re-paintability and hardness of a cured product of the crosslinkable composition.

[0513] Addendum 14:

[0514] A laminate comprising a substrate and a coating layer, the coating layer being obtained by curing the above crosslinkable composition according to any one of Appendices 1 to 6.

Claims

1. A crosslinkable composition comprising: Components (A) to (I) are diorganopolysiloxanes having a linear or branched structure and the molecular chain ends are capped with triorganosilyl groups; Components (A)-(II) having at least two (R 2 R 3 NCH2) groups and at least four (OR 4 ) group having a linear or branched structure of diorganopolysiloxane (R 2 represents a hydrogen atom or an optionally substituted monovalent straight or branched hydrocarbon group having 1 to 6 carbon atoms, R 3 is an optionally substituted monovalent straight or branched hydrocarbon group having 1 to 6 carbon atoms, a cyclic saturated hydrocarbon group having 5 or 6 carbon atoms, or a phenyl group, and R 4 , which may be the same as or different from each other, and each represents an optionally substituted monovalent hydrocarbon group); Component (B), which is a silane represented by the following formula (1) and / or a partial hydrolyzate thereof, (R 2 R 3 NCH2)Si(OR 4 )3(1); Component (C), which is an alkoxysilane represented by the following formula (2), R 21 4-x Si(OR 22 ) x (2) (In formula (2), R 21 , which may be the same as or different from each other, represent an optionally substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and R 22 , which may be the same as or different from each other, each representing an optionally substituted monovalent hydrocarbon group having 1 to 5 carbon atoms, wherein x is 2, 3 or 4); and Component (D), which is an organosilicon compound comprising a unit represented by the following formula (3), wherein at least one group D is present per molecule, and at least one group D has an NH2 group, D f Si(OR 32 ) e R 31 d O (4-d-e-f) / 2 (3) (In formula (3), R 31 , which may be the same as or different from each other, represent optionally substituted, nitrogen-free, monovalent SiC-bonded organic groups, R 32 , which may be the same as or different from each other, represent a hydrogen atom or an optionally substituted hydrocarbon group, D, which may be the same as or different from each other, represents a monovalent SiC-bonded group having at least one nitrogen atom which is not bonded to a carbonyl group (C═O), d is 0 or 1, e is 0, 1, 2, or 3, f is 0 or 1, and The sum of d, e and f is 4 or less).

2. The crosslinkable composition according to claim 1, further comprising: Component (E) which is an organosiloxane containing 2 to 30 units represented by the following formula (4) per molecule and containing at least one unit of formula (4) in which b is not 0: R 6 a (R 7 O) b SiO (4-a-b) / 2 (4) (In formula (4), R 6 , which may be the same as or different from each other, represent a monovalent SiC-bonded hydrocarbon group optionally substituted by a halogen atom or a Si-bonded halogen atom, R 7 , which may be the same as or different from each other, represent an optionally substituted monovalent hydrocarbon group, a is 0 or 1, b is 0, 1, 2, or 3, and a+b<4).

3. The crosslinkable composition according to claim 1 or 2, wherein the group R in the component (C) 22 It is ethoxy.

4. The crosslinkable composition according to claim 1 or 2, wherein the group (R 2 R 3 NCH2) is one selected from the group consisting of N,N-dimethylaminomethyl, N,N-diethylaminomethyl, N,N-di-n-propylaminomethyl and N,N-di-n-butylaminomethyl.

5. The crosslinkable composition according to claim 1 or 2, further comprising a component (F), wherein the component (F) is a filler.

6. The crosslinkable composition according to claim 1 or 2, comprising, relative to 100 parts by mass of the total amount of the components (A)-(I) and (A)-(II): 5 parts by mass or more and 20 parts by mass or less of the component (B), 10 parts by mass or more and 200 parts by mass or less of the component (C), 0.1 parts by mass or more and 2 parts by mass or less of the component (D), 0 parts by mass or more and 40 parts by mass or less of component (E), the component (E) being an organosiloxane containing 2 to 30 units represented by the following formula (4) per molecule and containing at least one unit of formula (4) in which b is not 0: R 6 a (R 7 O) b SiO (4-a-b) / 2 (4) (In formula (4), R 6 , which may be the same as or different from each other, represent a monovalent SiC-bonded hydrocarbon group optionally substituted by a halogen atom or a Si-bonded halogen atom, R 7 , which may be the same as or different from each other, represent an optionally substituted monovalent hydrocarbon group, a is 0 or 1, b is 0, 1, 2 or 3, and a+b<4), Component (F) which is a filler in an amount of 0 parts by mass or more and 30 parts by mass or less, and Component (G) which is an organic solvent in an amount of 0 parts by mass or more and 40 parts by mass or less.

7. A one-component moisture-curable coating agent comprising the crosslinkable composition according to claim 1 or 2.

8. A method for producing a crosslinkable composition according to claim 1 or 2, comprising: a first mixing step of blending the components (A)-(I) into a mixture of the components (A)-(II) and the component (B); a second mixing step of blending the component (C) into the mixture obtained in the first mixing step; and A third mixing step of blending the component (D) into the mixture obtained in the second mixing step.

9. A method for producing a coating, comprising: an application step of applying the crosslinkable composition according to claim 1 or 2 to a substrate; and a curing step of moisture-curing the crosslinkable composition applied in the applying step.

10. The method according to claim 9, wherein the crosslinkable composition is used in an amount of 50 g or more and 400 g or less per square meter of substrate surface area.

11. A method for repairing a coating, wherein the coating is a cured product of the crosslinkable composition according to claim 1 or 2, the method comprising applying the crosslinkable composition according to claim 1 or 2 on the surface of the coating.

12. The method of claim 9, wherein the substrate is one selected from the group consisting of cement-based materials, gypsum board, asphalt, wood, metal, resin, tile, glass, natural stone, artificial stone, and combinations thereof.

13. A crosslinkable composition comprising: Components (A) to (I) are diorganopolysiloxanes having a linear or branched structure, the molecular chain ends of which are capped with triorganosilyl groups; Components (A)-(II) having at least two (R 2 R 3 NCH2) groups and at least four (OR 4 ) group having a linear or branched structure of diorganopolysiloxane (R 2 represents a hydrogen atom or an optionally substituted monovalent straight or branched hydrocarbon group having 1 to 6 carbon atoms, R 3 is an optionally substituted monovalent straight or branched hydrocarbon group having 1 to 6 carbon atoms, a cyclic saturated hydrocarbon group having 5 or 6 carbon atoms, or a phenyl group, and R 4 , which may be the same as or different from each other, and each represents an optionally substituted monovalent hydrocarbon group); Component (B), which is a silane represented by the following formula (1) and / or a partial hydrolyzate thereof, (R 2 R 3 NCH2)Si(OR 4 )3(1); Component (C), which is an alkoxysilane represented by the following formula (2), R 21 4-x Si(OR 22 ) x (2) (In formula (2), R 21 , which may be the same as or different from each other, represent an optionally substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and R 22 , which may be the same as or different from each other, each representing an optionally substituted monovalent hydrocarbon group having 1 to 5 carbon atoms, wherein x is 2, 3 or 4); and Component (D), which is an organosilicon compound comprising a unit represented by the following formula (3), wherein at least one group D is present per molecule, and at least one group D has an NH2 group, D f Si(OR 32 ) e R 31 d O (4-d-e-f) / 2 (3) (In formula (3), R 31 , which may be the same as or different from each other, represent optionally substituted, nitrogen-free, monovalent SiC-bonded organic groups, R 32 , which may be the same as or different from each other, represent a hydrogen atom or an optionally substituted hydrocarbon group, D, which may be the same as or different from each other, represents a monovalent SiC-bonded group having at least one nitrogen atom which is not bonded to a carbonyl group (C═O), d is 0 or 1, e is 0, 1, 2, or 3, f is 0 or 1, and The sum of d, e and f is 4 or less), where The component (C) is blended in an amount of 10 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the total amount of the components (A)-(I) and (A)-(II), thereby improving the re-paintability and hardness of the cured product of the crosslinkable composition.

14. A laminate comprising: substrate; And a coating obtained by curing the crosslinkable composition according to claim 1 or 2.

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