JP2001302934A - Curable composition excellent in room-temperature curability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dealcoholization-type room-temperature-curable composition improved so that its curing rate is higher than that obtained by prior art. SOLUTION: This composition, excellent in room-temperature curability, contains (A) 100 pts.mass polymer having, on average, more than one hydrolysable group per molecule, (B) 1-25 pts.mass methoxysilance represented by the formula: R3bSi(OCH3)4-b (wherein R3 is a 1-8C hydrocarbon group; and (b) is 0 or 1) or its partial hydrolyzate condensate, and (C) 0.5-10 pts.mass chelate-type methyl titanate represented by the formula.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a room temperature curable composition, and more particularly to a room temperature curable composition having a high curing rate at room temperature.

[0002]

2. Description of the Related Art Conventionally, there have been known many compositions which cure at room temperature while releasing an alcohol by reacting an alkoxysilyl group upon contact with moisture in the air. Among these, a curable composition in which the polymer component is a polysiloxane, particularly a diorganopolysiloxane, is disclosed in
There have been many proposals, such as -3742. There have been many proposals for compositions in which the polymer component is a polyoxyalkylene, such as in JP-A-5-287261. Further, a composition in which the polymer component is polyisobutylene is described in J. Am. Many proposals have been made by Saam et al. In JP-A-8-165389.

[0003] Among these room-temperature curable compositions, those using organotitanate as a curable catalyst can be easily converted into a one-pack type composition in which there is no need to mix a main agent and a curing agent immediately before curing. known as a technology, for example, Japanese Patent Publication No. Sho 39-27643 (hydroxyl terminated _{polysiloxane, R n Si (oR) 4} -n -type silane and siloxane rubber raw material composition comprising an organic titanium compound), and JP-B 43-18625 JP have been proposed, such as the (hydroxyl terminated polysiloxane, R _n Si (oR) consisting _4-n-type silane and the organic titanium compound cold-curable sealant). Each of them,
As a base, a curable composition containing a diorganopolysiloxane having a terminal silanol group, an organotrialkoxysilane as a crosslinking agent, and a tetraalkyl titanate as a curing catalyst was used as a basic component.

However, this composition has two major problems. First, there was a problem with the cure speed. Specifically, there has been a problem that the curing speed is low, the curing speed is reduced during storage, the mechanical properties after curing are reduced, and finally the curability is lost. Second, there was a problem with the composition manufacturing process. Specifically, when the diorganopolysiloxane having a silanol group at a terminal is brought into contact with the diorganopolysiloxane, an extreme increase in viscosity occurs temporarily, so that the production method is extremely limited.

In US Pat. No. 3,334,067 or Japanese Patent Publication No. 56-14701, a composition using a chelated alkyl titanate instead of a tetraalkyl titanate (hydroxyl-terminated polysiloxane, R _n Si (OR A cold-curable composition comprising a _4-n type silane and a chelated alkyl titanate) is disclosed. According to these compositions, the problem of an extreme increase in viscosity when the polymer component comes into contact with the titanate catalyst is solved. However, even with these compositions,
The problem of the curing speed of the composition as disclosed in JP-B-39-27643 (the problem that the curing speed is low and the curing speed further decreases during storage) remains unsolved. It had been.

As another method for simultaneously solving the two problems in the means described in JP-B-39-27643, JP-A-55-43119 discloses a method.
A diorganopolysiloxane having a dialkoxysilyl group or a trialkoxysilyl group as a polymer component, and an organotrialkoxysilane as a crosslinking agent;
A curable composition containing a tetraalkyl titanate as a curing catalyst as a basic component is disclosed.

[0007] This composition improves the low curing rate, and makes it possible to produce a composition without causing an extreme increase in viscosity even when the tetraalkyl titanate catalyst is brought into contact with the polymer component. The problem of a gradual decrease in cure rate during storage has also been alleviated. However, the improvement in the reduction of the curing rate during storage is not sufficient, and when stored at a temperature of about 50 ° C., a clear reduction in the curing rate is observed in the order of several weeks, and especially when the composition is stored in summer. Is often a problem.

Further, Japanese Patent Publication No. 56-14701 discloses that a tetraalkyl titanate is a chelate type alkyl titanate (it is also described that an alkyl group bonded to titanium via oxygen is a lower alkyl group). In other words, a curable organopolysiloxane composition having improved storage stability (silanol-terminated polydiorganosiloxane is used as a polymer component, and organotrialkoxysilanes as a cross-linking agent, and a chelating alkyl titanate as a curing catalyst are used. Curable composition as a basic component)
Is disclosed.

[0009] The means described in Japanese Patent Publication No. 5-88866 is to restrict the particulate silica necessary for exhibiting the reinforcing property of the elastomer to hydrophobic silica.
To further improve storage stability, furthermore, a trialkoxysilyl group at a terminal, a trialkoxysilane as a crosslinking agent,
It is intended to obtain a higher curing rate by using a titanium chelate catalyst as a catalyst, limited to tetraalkoxysilane or a hydrolyzate thereof.

As another means for solving the problem of storage stability, Japanese Patent Application Laid-Open No. 2-133490 discloses that an organic titanium catalyst is prepared by forming an ethylene bond instead of a siloxane bond to a terminal alkoxysilyl group. Preferred catalysts are described as tetrabutyl titanate, tetraisopropyl titanate, bis (acetylacetonyl) diisopropyl titanate, and 2,5-diisopropoxy-bis (acetylacetonyl) diisopropyl titanium.臓 containing storage-stable sealant composition (alkoxy-terminated polyorganosiloxane, R _n Si (O
R) a curable composition comprising a _4-n type silane and an organotitanium catalyst).

As described above, there are various proposals for the problems of the cure rate and the storage stability of dealcoholated elastomer compositions using titanate soot, especially dealcoholated silicone elastomer compositions, and the composition manufacturing process. Has been improved. However, when compared to other room temperature-curable silicone elastomer curing systems such as de-acetic acid-type and de-oxime-type, the cure rate of the alcohol-free type is still at a low level. .

Before describing the constitution of the present invention, the prior art of a chelate type alkyl titanate catalyst will be described.
The above catalyst has two alkoxy groups bonded to the titanium atom of the chelate type alkyl titanate, or has one or more alkanedioxylate moieties having two or more bonding parts to the titanium atom in one molecule. It is common to have an oxylate moiety.

As described above, Japanese Patent Publication No. 56-14701 discloses many proposals that two alkoxy groups of a chelate type alkyl titanate can use a lower alkoxy group. Contains a methoxy group having 1 carbon atom.

However, the composition described in Japanese Patent Publication No. 56-14701 includes a silanol-terminated polydiorganosiloxane as a polymer component as described above. In addition, the publication does not specifically disclose a chelate-type titanate compound having a methoxy group. An example in which a chelated titanate compound having a methoxy group is specifically used can be found in U.S. Pat. No. 3,334,067, but as described above, the composition disclosed therein is a polymer. This is a room-temperature-curable composition using a hydroxyl-terminated polysiloxane as a component, which differs from the present invention in terms of the component, and does not disclose any features when the alkoxy group of the chelate type titanate compound is a methoxy group.

[0015]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a dealcoholizable composition which cures at room temperature with an improved cure speed which is higher than in the prior art.
More specifically, it is an object of the present invention to provide an improved dealcohol-type room temperature-curable composition which is easy to produce, has high storage stability, and has an unprecedentedly high curing rate.

[0016]

The present invention relates to (A) a polymer having an average of more than one hydrolyzable group per molecule, 100 parts by mass, and (B) a general formula: R ² _b Si ( OCH
₃ ) _4-b (wherein R ² is a hydrocarbon group having 1 to 8 carbon atoms, b
Is methoxysilane represented by 0 or 1) or a partially hydrolyzed condensate thereof, 0.1 to 25 parts by mass, and (C)
Chelating methyl titanate represented by the following general formula,
0.1 to 10 parts by mass,

Embedded image

[Where R¹Is a hydrocarbon having 1 to 8 carbon atoms
Group, a halogenated hydrocarbon group having 1 to 8 carbon atoms (hydrocarbon group
A part of the hydrogen atoms of
Or a perfluoroalkyl group having 1 to 8 carbon atoms (a
All hydrogen atoms in the alkyl group are replaced by fluorine atoms
A is -R^ThreeOr -0R^Three｛Where
-R ^ThreeIs a hydrocarbon group having 1 to 8 carbon atoms, and a halo having 1 to 8 carbon atoms.
Genated hydrocarbon group (Part of the hydrogen atoms in the hydrocarbon group
Is substituted with a halogen atom), or having 1 to 1 carbon atoms.
8 perfluoroalkyl group (the hydrogen atom of the alkyl group
All are substituted with fluorine atoms)⁸
Represents a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms, or
1 to 8 halogenated hydrocarbon groups (water with hydrocarbon groups)
In which some of the atoms are replaced by halogen atoms).
Devour. ] A curable composition having excellent curability at room temperature containing
You.

Further, the present invention relates to the above-mentioned inventions,
The polymer of the component (A) is selected from a polyorganosiloxane or a hydrocarbon polymer having an average of more than one hydrolyzable group in one molecule, and has excellent curability at room temperature. A composition.

Further, the invention of the present application is a curable composition excellent in room-temperature curability in which the polyorganosiloxane has a hydrolyzable group bonded to the silicon atom via an alkylene group in each of the above inventions. .

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The concrete form of the curable composition of the present invention will be described below. [(A) Polymer having more than one hydrolyzable group on average in one molecule] Component (A) serves as a base material of the curable composition of the present invention. The component (A) forms a cured product or a cured film by a condensation reaction with the crosslinking agent of the component (B). For this reason, a polymer having an average of more than one hydrolyzable group in one molecule is used as the component (A).

The chemical type of the component (A) polymer and the basic structure of the polymer as long as they satisfy the above conditions and do not adversely affect the excellent curability at room temperature, which is the effect of the present invention. The size and the like of the polymer are not particularly limited. Rather, for specific applications, those requirements are selected from the physical properties required of the cured product or cured film.
Examples of such a polymer will be described later, but typically include a polydiorganosiloxane, a hydrocarbon polymer or a copolymer thereof.

The structure of these polymers may be a linear polymer (which may have a branched structure arbitrarily) or a resin.

The size of the polymer varies depending on the type of the polymer, the size of the side chain substituent, etc., and will be described later. For example, in the case of polydiorganosiloxane, the curable composition of the present invention Considering the workability when applied to the application target and the physical properties after curing, the viscosity at room temperature is recommended to be 20 to 1,000,000 mPa · s. If it exceeds this range, the workability will fall below a practical level, and if it falls below this range, the properties of the cured product or cured film will be insufficient. Various polymers can be used as the polymer to which the hydrolyzable group is bonded, and polysiloxane-based polymers, polyoxyalkylene-based polymers, poly (meth) acryl-based polymers, polyisobutylene-based polymers, and polyethylene-based polymers can be used. Polymers. Hereinafter, suitable polymers will be further described.

[Polysiloxane-based polymer] Examples of the polysiloxane-based polymer include diorganopolysiloxanes such as polydimethylsiloxane, dimethyl-methylphenylsiloxane copolymer and polymethyltrichloropropylsiloxane, or RSi O _3/2 siloxane units;
₂ SiO _2/2 siloxane unit, R ₃ SiO _1/2 siloxane unit, or _{SiO 4/2} siloxane unit (wherein R
Is an unsubstituted or substituted monovalent hydrocarbon group, an alkoxy group,
Or a group selected from a hydroxyl group).

Among them, polydiorganosiloxane polymers are the most common, and among them, when polydimethylsiloxane is used, preferable characteristics can be obtained as a room temperature-curable silicone elastomer. RSi O
_3/2 siloxane unit, R ₂ SiO _2/2 siloxane unit,
When a polyorganosiloxane containing R ₃ SiO _1/2 siloxane units and _{SiO 4/2} siloxane units as main components is used, a composition which cures to give a resinous silicone can be obtained.

As an example of the case where the component A is a polydiorganosiloxane, there can be mentioned a silicone oil represented by the following general formula. General _{^{formula: (R 12 0) 3-}} k R 16 k Si-Y- [R 13 R 13 SiO] n -R 13 R 13 Si-
Y-Si (OR ¹² ) _3-k R ¹⁶ _k (R ¹² is independently an alkyl group having 1-6 carbon atoms or 2-8 carbon atoms.
R ¹³ is an organic group having 1 to 10 carbons independently, R ¹⁶ is independently a hydrocarbon group having 1 to 8 carbon atoms or a halogenated hydrocarbon group having 1 to 8 carbon atoms, k is O
, 1 or 2, and Y is an oxygen atom or a divalent hydrocarbon group having 2 to 5 carbon atoms, and n has a viscosity of 0.02 to 1,000 Pa · s at 25 ° C.
Is a positive number such that Here, considering the curability, the value of k is desirably O or 1, and more preferably, k = O is recommended.

In the above general formula, examples of R ¹³ include:
Alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, octyl, and decyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; alkenyl groups such as vinyl and allyl; aryl groups such as phenyl, tolyl and naphthyl; benzyl and phenylethyl Aralkyl groups such as phenylpropyl, and the like; and halogenated hydrocarbon groups such as chloromethyl, trifluoromethyl,
Chloropropyl, 3,3,3-trifluoropropyl, chlorophenyl, dibromophenyl, tetrachlorophenyl, difluorophenyl group and the like are exemplified, and as the cyanoalkyl group, β-cyanoethyl, γ-cyanopropyl, β-cyanopropyl group and the like. Is exemplified.

Examples of R ¹² include an alkyl group such as methyl, ethyl, propyl, butyl, and hexyl; and an alkoxy-substituted alkyl group such as methoxyethyl, ethoxyethyl, methoxydipropyl, and methoxybutyl. R ¹² and R ¹³ each preferably have 1 to 3 carbon atoms, more preferably a methyl group or an ethyl group. Y is an oxygen atom or a divalent hydrocarbon group, the divalent hydrocarbon radical _{-CH 2 CH 2 -, - CH} 2 CH 2 CH
_{2 -, - CH 2 C (} CH 3) H- alkylene group such as and the like.

When the component (A) is a polydiorganosiloxane, the viscosity at 25 ° C. is preferably in the range of 0.02 to 1000 Pa · s. This is because it is difficult to give the cured elastomer excellent physical properties, particularly flexibility and high elongation if it is smaller than O.02 Pa · s, and 1000 Pa
-If it is larger than s, the viscosity of the composition becomes high, and the workability at the time of construction deteriorates remarkably. Therefore, it is more preferably in the range of 0.1 to 500 Pa · s. As described above, various polymers can be used as the polyorganosiloxane-based polymer (see JP-A-55-43119).

[Polyoxyalkylene polymer] Any polyoxyalkylene polymer having an average of more than one hydrolyzable group in one molecule can be used as the polymer (A) of the present invention. The polyoxyalkylene-based polymer has a repeating unit whose main chain skeleton is -RO- (wherein R represents a divalent organic group).

The repeating unit is not particularly limited, but may be, for example, —CH ₂ O—, —CH ₂ CH ₂ O
_{-, - CH 2 CH (CH} 3) O -, - CH 2 CH (C 2
_{H 5) O -, - CH} 2 C (CH 3) 2 O -, - CH 2 C
H ₂ CH ₂ CH ₂ O— and the like can be mentioned. Further, the main chain skeleton may be a combination of two or more of them. Specifically, examples of the polyoxyalkylene polymer include polyoxyethylene and polyoxypropylene. In particular, when polyoxypropylene is used, it is possible to obtain a composition which cures at room temperature used for a sealant or the like and becomes an elastomer.

The main chain skeleton of the oxyalkylene-based polymer may contain other components such as a urethane bond component as long as the properties of the oxyalkylene-based polymer are not significantly impaired. The urethane binding component is not particularly limited, and examples thereof include aromatic polyisocyanates such as toluene (tolylene) diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate; aliphatic polyisocyanates such as isophorone diisocyanate and hexamethylene diisocyanate; Examples thereof include those obtained from a reaction with a polyol having a repeating unit.

The hydrolyzable group of the polyoxyalkylene-based polymer may be located at the terminal of the polyoxyalkylene or at (part of) the main chain structure of the polyoxyalkylene. It may include both of them. The polyoxyalkylene may be linear or have a branched structure, and has a molecular weight of 50.
It is preferably about 0 to 50,000 (number average molecular weight). As described above, various polymers can be used as the polyoxyalkylene-based polymer (see, for example, JP-A-11-80533 as an example of an oxyalkylene-based copolymer containing at least one reactive silicon in one molecule). )

[Polyacrylic Polymer] As the polymer component (A) of the present invention, an acrylic polymer having more than one hydrolyzable group on average in one molecule can be used. The hydrolyzable group may be located at the terminal of the acrylic polymer, or may be introduced as a side chain.

Specific examples of the polymethacrylate-based polymer include acrylic polymers such as a polymer mainly composed of polymethyl methacrylate and a copolymer mainly composed of polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate and the like. Examples are based polymers.

The method for producing an acrylic polymer in the present invention is, for example, when the hydrolyzable group is an alkoxysilyl group, copolymerization of acrylic acid, methacrylic acid, or a derivative thereof with an alkoxysilyl group-containing vinyl monomer. Can be mentioned.

The acrylic polymer in the present invention may contain a segment formed by a siloxane bond in the main chain as long as the effects of the present invention are not reduced. Further, the acrylic polymer may be a copolymer of the above monomer and other components. Examples of this include:

Aromatic vinyl compounds such as styrene, α-methylstyrene, chlorostyrene, styrenesulfonic acid, 4-hydroxystyrene and vinyltoluene; unsaturated carboxylic acids such as maleic acid, fumaric acid and itaconic acid; Salts thereof (alkali metal salts, ammonium salts, amine salts, etc.), their acid anhydrides (maleic anhydride, etc.), or diesters or halfesters thereof with linear or branched alcohols having 1 to 20 carbon atoms Esters of unsaturated carboxylic acids such as;

Vinyl esters and allyl compounds such as vinyl acetate, vinyl propionate and diallyl phthalate; vinyl compounds containing amino groups such as vinyl pyridine and aminoethyl vinyl ether; itaconic diamide, crotonamide, maleic diamide, fumaric diamide; N
Amide group-containing vinyl compounds such as vinylpyrrolidone; 2-hydroxyethyl vinyl ether, methyl vinyl ether,

Cyclohexyl vinyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, isoprene, fluoroolefin maleimide,
Other vinyl compounds such as N-vinylimidazole and vinylsulfonic acid are included.

The molecular weight (number average amount) of the acrylic polymer is from 1000 to 30 in view of the physical properties of the cured product.
000 is preferred. As described above, various polymers can be used as the polyacrylic polymer (see, for example, JP-A-5-230318 as an example of the alkoxysilyl group-containing acrylic copolymer according to the present invention).

[Polyisobutylene-based Polymer] As the polymer component (A) of the present invention, polyisobutylene having more than one hydrolyzable group on average per molecule can be used.

The hydrolyzable group may be located at the terminal of polyisobutylene, or may be introduced as a side chain. The molecular weight (number average molecular weight) of the polyisobutylene is 1000 to 400 in consideration of the physical properties of the cured product.
A range of 00 is preferred. The polyisobutylene may be a copolymer containing the following units in the main chain.

Specifically, 1-butene, 2-butene, 2
-Methyl-1-butene, 3-methyl-1-butene, pentene, 4-methyl-1-pentene, hexene, cyclohexene, vinylcyclohexene, styrene, α-methylstyrene, dimethylstyrene, monochlorostyrene, dichlorostyrene, β Aliphatic olefins such as -pinene, 5-ethylidene norbornene, indene; butadiene;
Dienes such as isoprene and cyclopentadiene; styrenes such as styrene, α-methylstyrene and p-chlorostyrene;

Alkenyl ethers such as methyl vinyl ether, ethyl vinyl ether and isobutyl vinyl ether; divinyldimethylsilane, vinyltrimethylsilane, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, trivinylsilane, tetravinylsilane, Alkenylsilanes such as allyltrimethylsilane and diallylmethylsilane can be exemplified. As described above, various polymers can be used as the polyisobutylene-based polymer (see JP-A-9-286895, JP-A-8-165389, etc.).

[Polyethylene Polymer] As the polymer component (A) of the present invention, polyethylene having more than one hydrolyzable group on average in one molecule can be used. The hydrolyzable group may be located at the terminal of the polyethylene or may be introduced as a side chain. Polyethylene molecular weight (number average molecular weight)
Is from 1,000 to 40,000 in consideration of the physical properties of the cured product.
A range of 0 is preferred. Further, an alkoxysilyl group is preferable as the hydrolyzable group for this polyethylene. Polyethylene may be a copolymer with another ethylene-based monomer. As described above, various kinds of polymers can be used as the polyethylene-based polymer (Japanese Unexamined Patent Publication No.
286895, etc.).

The term "hydrolyzable group" as used herein refers to a hydrolyzable group in a polymer having a hydrolyzable group, which has a silicon atom and is capable of undergoing a condensation reaction by hydrolysis. It is not particularly limited as long as it does not generate by-products that adversely affect the environment.
Typically, those selected from the following (a), (b) or (c) are mentioned.

[0048]

Embedded image (Where R is independently a hydrocarbon group having 1 to 8 carbon atoms, or a halogenated hydrocarbon group having 1 to 8 carbon atoms, W is independently an alkoxy group having 1 to 6 carbon atoms, Alkoxy substituted alkoxy, acyloxy [RC (= O) -0-, R
Is an alkyl group] (representative example is an acetoxy group), alkenyloxy group (representative example is a propenoxy group [CH ₂ CC (CH ₃ ) —O—
]), An aryloxy group [RO- and R are aryl groups]
(A typical example is a phenoxy group) or an oxime group, an amino group, an amide group, an aminooxy group or a mercapto group represented by R ₂ C = NO- [R is an aliphatic hydrocarbon group]. . In particular, a polymer in which an alkoxysilyl group or an alkoxy-substituted alkoxysilyl group is bonded to a polyorganosiloxane via a chain hydrocarbon is preferable. The alkoxysilyl group will be described in detail below.

A curable composition in which the hydrolyzable group of the polymer (A) is represented by the following general formula (1) or (2) is excellent in storage stability and curing speed.

[0050]

Embedded image (Wherein, R ⁴ is independently a C1-8 hydrocarbon group or halogenated hydrocarbon group having 1 to 8 carbon atoms, R ⁵ is C 1 -C
To 6 alkyl groups or alkoxy substituted alkyl groups having 2 to 8 carbon atoms)

Regarding the number of hydrolyzable groups, the case where the hydrolyzable group is an alkoxysilyl group will be representatively described.
It is necessary that the above various polymers have more than one alkoxysilyl group on average in one molecule as described above. When the average number of alkoxysilyl groups is 1 or less, insufficient curing results are obtained. When the average number of alkoxysilyl groups such that the alkoxysilyl groups are present only at both ends of the linear polymer is 2, a room-temperature curable composition suitable for an elastomer can be obtained. When the average number of alkoxysilyl groups is more than 1 and less than 2, a room-temperature curable composition suitable for a gel-like or soft elastomer can be obtained. When the average number of alkoxysilyl groups exceeds 2, the cured composition increases in hardness, and finally becomes a composition suitable for obtaining a resinous cured product.

The same tendency is observed not only in the case of a linear polymer but also in the case of using a polymer having a branched or three-dimensionally densely crosslinked structure. These are all useful cured products and can be used as the component (A) of the present invention.

The hydrolyzable group is bonded to the polymer (A) directly or via an alkylene group (bonding group).
As the bonding group, a methylene group (-CH ₂ -), ethylene group (-CH ₂ CH ₂ -), propylene (-CH ₂
CH ₂ CH ₂ -) and the like are exemplified. Although it has been described that the case of bonding via an alkylene group is preferred, the cured product obtained generally increases flexibility as the number of carbon atoms of the bonding group increases.

A curable composition containing a polymer component having a hydrolyzable group via a bonding group other than an alkylene group may adversely affect the physical properties of the cured polymer composition, and should be avoided. . For example, when the alkoxysilyl group is bonded to an organic polymer via a silicon-oxygen-carbon bond, the cured portion is susceptible to hydrolysis after curing,
As a result, there is a possibility that problems such as deterioration of properties after curing due to water or moisture may occur, so it is better to avoid them.

On average, one molecule in component (A) constitutes one component.
When the polymer having more than one hydrolyzable group has an alkoxysilyl group as the hydrolyzable group, the alkoxysilyl group can be used if it has a structure in which one or more alkoxy groups are bonded to a silicon atom. . The alkoxy group has 1 to 6 carbon atoms, and specific examples thereof include a methoxy group, an ethoxy group, a normal propoxy group, an isopropoxy group, a normal butoxy group, an isobutoxy group and a t-butoxy group. . One to three such alkoxy groups are bonded to the silicon atom bonded to the polymer. One or two monovalent hydrocarbon groups or monovalent halogenated hydrocarbon groups may be bonded to the silicon atom to which the alkoxy group is bonded, in addition to the alkylene group as a bonding group to the polymer. As such a monovalent hydrocarbon group, those having 1 to 8 carbon atoms are preferable, and specifically, an alkyl group such as a methyl group and an ethyl group, an alkenyl group such as a vinyl group, and an aryl group such as a phenyl group are preferable. Can be exemplified. Further, as the monovalent halogenated hydrocarbon group,
Those having 1 to 8 carbon atoms are preferred, and specific examples include a 3,3,3-trifluoropropyl group.

Specific examples of the above-mentioned alkoxysilyl groups having three alkoxy groups include trimethoxysilyl, triethoxysilyl, and tripropoxysilyl.

Specific examples of the alkoxysilyl group having two alkoxy groups include methyldimethoxysilyl, vinyldimethoxysilyl, ethyldimethoxysilyl, methyldiethoxysilyl, vinyldiethoxysilyl,
Examples thereof include a methyldipropoxysilyl group, a methyldibutoxysilyl group, a vinyldibutoxysilyl group, and a vinyldipropoxysilyl group.

Specific examples of the alkoxysilyl group having one alkoxy group include dimethylmethoxysilyl, divinylmethoxysilyl, diethylmethoxysilyl, dimethylethoxysilyl, divinylethoxysilyl,
Examples thereof include a dimethylpropoxysilyl group, a dimethylbutoxysilyl group, and a divinylbutoxysilyl group.

In order to obtain higher curability, a silyl group having three alkoxy groups or a silyl group having two alkoxy groups is desirable. In this case, a methoxy group or an ethoxy group is recommended as the alkoxy group. Specific examples include a silyl group having three methoxy groups, a silyl group having three ethoxy groups, a silyl group having two methoxy groups, and a silyl group having two ethoxy groups. The above-mentioned tendency regarding the alkoxysilyl group can be said to be the same for other hydrolyzable groups.

[Method of Introducing Hydrolyzable Group such as Alkoxysilyl Group] A known method can be used to introduce the alkoxysilyl group into the polymer. For example, a method in which a hydrosilane having an alkoxysilyl group is allowed to act on a polymer having a functional group such as a hydroxyl group at a terminal or a polymer in which a hydroxyl group is introduced into a polymer basic skeleton by copolymerization with an epoxy compound, to perform hydrosilylation. To the unsaturated group of the polymer containing the unsaturated group introduced by
Method for reacting a compound having a mercapto group and an alkoxysilyl group, a compound having a functional group such as a hydroxyl group, an epoxy group, and an isocyanate group introduced into a polymer and having another functional group and an alkoxysilyl group reactive with the functional group And the like. In a similar manner, other hydrolyzable groups can be introduced into the polymer.

[(A) Polymer Having Alkoxysilyl Group] Specific examples of the polymer having an alkoxysilyl group suitable as the polymer of the component (A) used in the present invention include a linear polymer. Examples of the polydiorganosiloxane having an alkoxysilyl group at the terminal include those represented by the following formula.

[0062]

Embedded image

Further, a diorganopolysiloxane having an alkoxysilyl group in the middle of a diorganopolysiloxane chain in addition to both terminals represented by the following formula can also be exemplified.

Embedded image

The average unit formula is represented by the following formula:
An organopolysiloxane having an alkoxysilyl group having a highly branched structure can also be exemplified. (CH ₃ SiO _3/2 ) / ((CH ₃ ) ₂ SiO) / (C
H ₃ O _1/2 )

[(B) Methoxysilane or a partial addition thereof
Hydrolysis condensate] The meth of the component (B) used in the present invention
Xysilane or its partial hydrolyzate is used as a crosslinking agent.
Having a function, a general formula: R^Two _bSi (OCH_Three)_4-b(formula
Medium, R ^TwoIs a hydrocarbon group having 1 to 8 carbon atoms, b is 0 or 1
Methoxysilane or a partial hydrolyzate thereof
It is a decomposition condensate.

Specific examples of the component (B) include:
Methyltrimethoxysilane, ethyltrimethoxysilane,
Trifunctional methoxysilanes such as vinyltrimethoxysilane and phenyltrimethoxysilane: tetrafunctional tetramethoxysilane, and hydrolysis condensates thereof. As the component (B), these compounds may be used alone, or two or more kinds may be used as a mixture. Also, methoxy oligosiloxanes obtained by partially hydrolyzing these methoxy silanes can be used.

Component (B) is added in an amount of 0.1 to 25 parts by mass, preferably 1 to 10 parts by mass, per 100 parts by mass of component (A). This is because if the amount is too small, the composition of the present invention will be insufficiently cured, or will tend to gel during storage due to thickening, and if too large, the curing will be slow or cost disadvantageous. Because it becomes.

[(C) Chelating Methyl Titanate] The component (C) used in the present invention is a chelating methyl titanate represented by the following general formula.

Embedded image[Where R¹Is a hydrocarbon group having 1 to 8 carbon atoms,
8 halogenated hydrocarbon group (hydrogen source of hydrocarbon group)
Or a carbon atom is partially substituted with a halogen atom) or carbon
A perfluoroalkyl group of the formulas 1 to 8 (hydrogen of the alkyl group
All of the atoms have been replaced by fluorine atoms)
Is -R^ThreeOr -0R^ThreeWhere -R ^ThreeIs 1 carbon
To 8 hydrocarbon groups, halogenated hydrocarbons having 1 to 8 carbon atoms
Group (Part of the hydrogen atoms of the hydrocarbon group are halogen atoms
) Or perfluorinated with 1 to 8 carbon atoms
All alkyl group hydrogen atoms are fluorine atoms
Selected from｝, R⁸Is hydrogen atom, charcoal
A hydrocarbon group having 1 to 8 carbon atoms or a halogen group having 1 to 8 carbon atoms
Hydrogenated hydrocarbon group (part of the hydrogen atoms of the hydrocarbon group
Substituted with a halogen atom). ]

This functions as a curing catalyst in the composition of the present invention. Examples of such chelated methyl titanates include compounds having the following groups.

[Examples of R ¹ ] Hydrocarbon groups having 1 to 8 carbon atoms: methyl, ethyl, propyl, t-butyl, n-butyl, t-pentyl and the like halogens having 1 to 8 carbon atoms Hydrocarbon group: 3,3,3-trifluoropropyl group, etc. Perfluoroalkyl group having 1 to 8 carbon atoms: trifluoromethyl group, pentafluoroethyl group, etc.

[0071] [Exemplary A] (when A is -R ³⁾ a hydrocarbon group having 1-8 carbon atoms: methyl, ethyl, propyl, t - butyl, n - butyl group, t - pentyl Halogenated hydrocarbon group having 1 to 8 carbon atoms: 3,3,3-trifluoropropyl group, etc.Perfluoroalkyl group having 1 to 8 carbon atoms: trifluoromethyl group, pentafluoroethyl group, etc.

(When A is —OR ³ ) An alkoxy group having 1 to 8 carbon atoms: a methoxy group, an ethoxy group, a propoxy group, a butoxy group and the like. Of these, a methoxy group is preferably selected.

[Examples of R ⁸ ] Methyl group, ethyl group, propyl group, hydrogen atom, etc.

The addition amount of the component (C) is in the range of 0.1 to 10 parts by mass, preferably 1 to 5 parts by mass, per 100 parts by mass of the component (A). This is because if the addition amount is too small, the curing of the composition of the present invention is delayed,
If the amount is too large, the storage stability deteriorates, and the cost becomes disadvantageous.

The composition of the present invention comprises the component (A)
(C) It consists of a component, In addition to these components, various additives, for example, a diluent, a plasticizer, a physical property modifier after curing, an adhesion imparting agent, an inorganic filler, an organic solvent, a fungicide, a flame retardant Incorporation of a heat-resistant agent, a thixotropy-imparting agent, a curing accelerator, a curing speed regulator, an antioxidant, an ultraviolet absorber, a light stabilizer, a pigment, etc. may be used as long as the object of the present invention is not impaired. Although these additives are conventionally known substances, among them, inorganic fillers often play an important role in improving the mechanical properties of the composition after curing. Silica, precipitated silica, quartz fine powder, calcium carbonate, fumed titanium dioxide, diatomaceous earth, aluminum hydroxide powder, alumina powder, magnesium powder, zinc oxide powder, zinc carbonate powder, and organosilanes, silazane And hydrophobicized by surface treatment with siloxane oligomers.

The composition of the present invention comprises the components (A) to (C)
It can be easily produced by uniformly mixing the components and, if necessary, various additives under the exclusion of moisture. If the obtained composition of the present invention is sealed and stored in a closed container and released into the air at the time of use, it can be cured by the moisture present in the air. Further, the composition of the present invention can be used by storing the components (A) to (C) separately in two packages and mixing them immediately before curing. For example, a method of uniformly mixing the components (A) and (B) into a first package and separating and storing the component (C) as a second package can be shown. Accordingly, various additives are generally added to the first or second package and uniformly mixed.

The composition of the present invention as described above can be stored stably for a long period of time as a composition in which all the components are uniformly mixed under the condition that moisture is cut off. Since it cures quickly, it is extremely effective as a coating agent, a sealing agent, a potting agent, an adhesive, a sealant, and the like.

[0078]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. In the examples, the viscosity is a value measured at 25 ° C. The surface hardening time is determined by skin over time (SOT: Skini)
ng Over Time) and tack free time (T
FT: Tack FreeTime).

[Measurement of SOT] The curable composition of the present invention was applied to a substrate (PET film) to a thickness of about 3 mm, and the surface was left under a condition of 20 ° C. and a relative humidity of 55%. Observation was performed by touch, and when the surface was touched with a fingertip, the time until the curable composition did not adhere to the fingertip (elapsed time after application) was measured.

[Measurement of TFT] The curable composition of the present invention was applied to a substrate (PET film) to a thickness of about 3 mm, and a polyethylene film was formed thereon at 20 ° C. and a relative humidity of 55%. After placing on the top and further placing a 30 g weight thereon for 30 seconds, the polyethylene film was peeled off, and the time until the curable composition did not adhere (elapsed time after application) was measured. The measurement is performed at the initial stage (elapsed
Minutes) to 10 minutes, every 1 minute (peel the polyethylene film every 1 minute of elapsed time; the same applies hereinafter), and every 10 minutes to 20 minutes, every 2 minutes, 20 minutes of elapsed time The test was performed every 5 minutes up to 160 minutes.

Example 1 α, ω- having a viscosity of 20 Pa · s
Triethoxysilylethylene polydimethylsiloxane 9
3 parts by mass, 5 parts by mass of methyltrimethoxysilane, and bis (methylacetoacetate) dimethyltitanate 2
A room temperature curable composition was prepared by uniformly mixing the parts by mass and transferred to a glass bottle. After 2 hours, a small amount of the composition is put into the air and the skin over time (SOT)
And tack free time (TFT) were measured. SOT was 6 minutes and TFT was 12 minutes. The composition is heated at 50 ° C. for 10
After storage for a few days, a small amount of the composition is taken out into the air and
T and TFT were measured again. SOT is 6 minutes, TFT is 1
Two minutes.

Comparative Example 1 A curable composition at room temperature was prepared in the same manner as in Example 1 except that bis (methyl acetoacetate) dimethyl titanate in Example 1 was changed to bis (methyl acetoacetate) diisopropyl titanate. Then, the surface curability was measured in the same manner as in Example 1.
2 hours after composition preparation, SOT is 8 minutes, TFT is 13 minutes,
After aging for 10 days at 50 ° C., the SOT was 9 minutes,
The FT was 15 minutes. Example 1 and Comparative Example 1 show that in the case of titanate in which methyl acetoacetate is chelated and the alkoxy group directly bonded to the titanium atom is a methoxy group, room temperature curability is higher than that in the case of an isopropoxy group. Was.

Comparative Example 2 The α, ω-ditriethoxysilylethylene polydimethylsiloxane of Example 1 was replaced with a polydimethylsiloxy-α, ω- having a viscosity of 19 Pa · s.
A room temperature curable composition was prepared in the same manner as in Example 1 except that the diol was changed, and the surface curability was measured in the same manner as in Example 1. SOT after 2 hours of composition preparation is 10 minutes, T
FT is 18 minutes, after aging for 10 days at 50 ° C.
OT was 35 minutes and TFT was 48 minutes. Even when a chelate-type methyl titanate was used, when the component (A) was a silanol-functional polymer, the curing rate was low, and the curing rate was further reduced over time. And Comparative Example 2.

Example 2 A room temperature curable composition was prepared in the same manner as in Example 1 except that bis (methyl acetoacetate) dimethyl titanate in Example 1 was changed to bis (methyl pivaloyl acetate) dimethyl titanate. Was prepared and the surface curability was measured in the same manner as in Example 1. After 2 hours from the preparation of the composition, the SOT was 6 minutes and the TFT was 12 minutes.
After aging at 0 ° C. for 10 days, SOT was 6 minutes, TF
T was 12 minutes.

Comparative Example 3 A curable composition at room temperature was prepared in the same manner as in Example 2 except that bis (methylpivaloylacetonyl) dimethyltitanate in Example 2 was changed to bis (methylpivaloylacetonyl) diisopropyl titanate. A composition was prepared, and the surface curability was measured in the same manner as in Example 2. The SOT was 2 minutes after the preparation of the composition was 7 minutes, the TFT was 15 minutes, the SOT after aging at 50 ° C. for 10 days was 8 minutes, and the TFT was 18 minutes.

Comparative Example 4 The bis (methylpivaloylacetonyl) dimethyltitanate of Example 2 was replaced with
(Methylpivaloylacetonyl) A room temperature curable composition was prepared in the same manner as in Example 2 except that di-t-butyl titanate was used, and the surface curability was measured in the same manner as in Example 2. The SOT was 2 minutes after the preparation of the composition was 7 minutes, the TFT was 12 minutes, the SOT after aging at 50 ° C. for 10 days was 8 minutes, and the TFT was 14 minutes. Methyl pivaloyl acetate is a chelate coordinated titanate, and when the alkoxy group directly bonded to the titanium atom is a methoxy group, it shows higher room temperature curability than the isopropoxy group or the t-butoxy group. This is shown in Example 2 and Comparative Examples 3 and 4.

Example 3 α, ω-Ditrimethoxydisiloxypolydimethylsiloxane (content: 69% by mass)
α-trimethoxydisiloxy-ω-trimethylsiloxydimethylpolysiloxane (content 28% by mass), α, ω
100 parts by mass of polydimethylsiloxane having a viscosity of 17 Pa · s (average content of 1.67 alkoxysilyl groups in one molecule) composed of ditrimethylsiloxypolydimethylsiloxane (content 3% by mass), and the surface thereof was treated with dimethylchlorosilane. After uniformly mixing 12 parts by mass of fumed silica (BET specific surface area: 120 m ² / g) subjected to hydrophobizing treatment, 4.5 parts by mass of methyltrimethoxysilane, γ-aminopropyltrimethoxysilane and γ-glycidoxypropyl Reaction mixture of trimethoxysilane (γ-aminopropyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane were mixed at a molar ratio of 1: 2, and then mixed at a temperature of 25 ° C. and a humidity of 50%. Left for a week)
0.5 parts by mass, and bis (methyl acetoacetate)
A room temperature-curable composition was prepared by uniformly mixing 3 parts by mass of dimethyl titanate under the condition that air and moisture were not mixed, and transferred to a polyethylene cartridge.
After the composition was stored at 50 ° C. for 10 days, it was taken out into the air, and SOT and TFT were measured again. SOT is 3 minutes, T
The FT was 12 minutes. Make a sheet about 3mm thick and 7
The mechanical properties measured after curing for one day were as follows: The hardness was 28, the tensile strength was 22.4 kPa, and the maximum elongation was 360%.

Comparative Example 5 A room temperature curable composition was prepared in the same manner as in Example 3 except that bis (methyl acetoacetate) dimethyl titanate in Example 3 was changed to bis (methyl acetoacetate) diisopropyl titanate. The cure speed and post-cure mechanical properties were measured. SOT
Was 4 minutes and TFT was 18 minutes. The mechanical properties measured after forming a sheet having a thickness of about 3 mm and curing for 7 days were as follows. Hardness 27, tensile strength 23.5 kPa
(23 kg / cm ² ) and the maximum elongation was 380%.

Example 4 10 g of polyisobutylene having a viscosity of 10 Pa · s having 3-methyldimethoxysilylpropyl groups at both ends and liquid paraffin having a viscosity of 0.4 Pa · s (Daphne Oil KP (manufactured by Idemitsu Kosan Co., Ltd.)) 5
g, methyltrimethoxysilane 0.25 g, and bis (methylacetoacetate) dimethyltitanate 3.8 g were uniformly mixed and transferred to a glass bottle. After aging this composition at 50 ° C. for 10 days, the surface curability was measured. S
OT was 2.5 hours and TFT was 4 hours.

Comparative Example 6 A room temperature curable composition was prepared in the same manner as in Example 4 except that bis (methyl acetoacetate) dimethyl titanate in Example 4 was changed to bis (methyl acetoacetate) diisopropyl titanate. Then, the surface curability was measured in the same manner as in Example 4.
SOT was 3 hours and TFT was 5 hours.

[0091]

The curable composition of the present invention comprises a component (A) and a component (C), in particular, a polymer having an alkoxysilyl group as the component (A) and a chelate-type methyl titanate as the component (C). As a result, the composition has an unprecedented high-speed curability, and the curability hardly changes during storage of the composition before curing.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 83/02 C08L 83/02 83/04 83/04 83/06 83/06 // C09D 183/02 C09D 183/02 183/04 183/04 183/06 183/06 201/02 201/02 F-term (reference) 4J002 BB04W BB18W BB20W BG02W CH05W CP02X CP03W CP03X CP08W EE047 EX036 FD010 FD157 GH00 GJ01 GJ02 4J03 AB01AB12A CA06K CA061 EA01 EB03 HA01 LB02 LB03 4J038 CA021 CA081 CB031 CB131 CC031 CD021 CD081 CF021 CG071 CG091 CG141 CJ081 CK021 CK031 CK041 DF011 DL021 DL022 DL032 DL071 EA011GA01 GA01 GA03

Claims (4)

[Claims] (A) More than one molecule on average per molecule.
Polymer having a water-decomposable group, 100 parts by mass, (B) general
Formula: R^Two _bSi (OCH_Three)_4-b(Where R^TwoIs the carbon number
1 to 8 hydrocarbon groups, b is 0 or 1)
Xysilane or a partially hydrolyzed condensate thereof, 0.1 to 2
5 parts by mass, (C) a chelate type methyl compound represented by the following general formula
Lutitanate, 0.1 to 10 parts by mass[Where R¹Is a hydrocarbon group having 1 to 8 carbon atoms,
8 halogenated hydrocarbon group (hydrogen source of hydrocarbon group)
Or a carbon atom is partially substituted with a halogen atom) or carbon
A perfluoroalkyl group of the formulas 1 to 8 (hydrogen of the alkyl group
All of the atoms have been replaced by fluorine atoms)
Is -R^ThreeOr -0R^ThreeWhere -R ^ThreeIs 1 carbon
To 8 hydrocarbon groups, halogenated hydrocarbons having 1 to 8 carbon atoms
Group (Part of the hydrogen atoms of the hydrocarbon group are halogen atoms
) Or perfluorinated with 1 to 8 carbon atoms
All alkyl group hydrogen atoms are fluorine atoms
Selected from｝, R⁸Is hydrogen atom, charcoal
A hydrocarbon group having 1 to 8 carbon atoms or a halogen group having 1 to 8 carbon atoms
Hydrogenated hydrocarbon group (part of the hydrogen atoms of the hydrocarbon group
Substituted with a halogen atom). ]
A curable composition having excellent room temperature curability. 2. The curable composition excellent in room temperature curability according to claim 1, wherein the hydrolyzable group of the polymer (A) is represented by the following general formula (1) or (2). . Embedded image (Wherein, R ⁴ is a C 1-8 hydrocarbon group or a C 1-8 halogenated hydrocarbon group, and R ⁵ is a C 1-6 alkyl group or a C 2-8 alkoxy group substitution. Alkyl group) 3. The polymer (A) is selected from a polyorganosiloxane or a hydrocarbon polymer having an average of more than one hydrolyzable group in one molecule.
The curable composition according to claim 1, which has excellent curability at room temperature. 4. The curable composition excellent in room temperature curability according to claim 2, wherein the polyorganosiloxane has a hydrolyzable group bonded to the silicon atom via an alkylene group.