JP3315210B2 - Curable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curable composition having excellent mechanical properties and deep curability and capable of imparting heat resistance, weather resistance and the like.

[0002]

2. Description of the Related Art A silicon atom-containing group having a hydroxyl group or a hydrolyzable group bonded to a silicon atom and capable of crosslinking by forming a siloxane bond (hereinafter referred to as "reactive silicon group")
Oxyalkylene-based polymer having a polymer terminal at the molecular end is already known, and is cured by moisture even at ordinary temperature,
Since it has an interesting property that a rubber-like cured product can be obtained, it is used in a large amount. However, the oxyalkylene polymer has a problem in that the cured product obtained by curing the polymer has insufficient properties such as heat resistance, water resistance, and weather resistance.

In order to solve such problems, for example, isobutylene-based polymers having a reactive silicon group at the terminal of a molecular chain have been studied (Japanese Patent Application Laid-Open No. 63-6041). However, the heat resistance, weather resistance, and moisture barrier properties of the cured product from these isobutylene-based polymers are significantly improved as compared with those of the cured product from the oxyalkylene-based polymer, but the cured product is Because of its good moisture barrier properties, when cured with moisture in the air, there is a problem that it takes about one week for a thick cured product to cure from the surface and completely cure.

In order to solve the above problems, a method of using a low molecular compound having a silanol group as a crosslinking component has been studied (Japanese Patent Laid-Open No. 2-196842). However, there is a problem in compatibility between the crosslinking component and the polymer, and there is a problem that the physical properties of the cured product are adversely affected.
Attempts have also been made to produce compounds having a silanol group at the terminal, but the silanol group has high reactivity and has not been produced stably.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems of the prior art, to cure quickly at room temperature, and to cure deeply (easiness of curing inside the cured product), An object of the present invention is to provide a curable composition which can provide a rubber-like cured product having heat resistance, water resistance, weather resistance, high strength and high elongation.

[0006]

Means for Solving the Problems As a result of earnest studies, the present inventors have conducted hydrolysis after a hydrosilylation reaction between a saturated hydrocarbon polymer having an unsaturated group and a specific silicon hydride compound, thereby carrying out hydrolysis. The present invention has been accomplished by stably producing a saturated hydrocarbon polymer having a silanol group, and using this saturated hydrocarbon polymer as one component of a curable composition.

[0007] The present invention, under Symbol (A), (B), the curable composition comprising the component (C) has a hydroxyl group bonded to (A) a silicon atom, of crosslinking by forming a siloxane bond (B) a silicon having a hydrolyzable group (excluding a hydroxyl group) bonded to a silicon atom and capable of being crosslinked by forming a siloxane bond, A saturated hydrocarbon polymer having at least one atom in a molecule, (C) a silanol condensation catalyst.

[0008] The component (A) of the curable composition of the present invention is not particularly limited as long as it is a saturated hydrocarbon polymer having a silanol group. The method for producing the component (A) is not particularly limited, but may be represented by the general formula (I):

[0009]

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(Wherein R ¹ and R ² are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms) At least one saturated hydrocarbon polymer in the molecular chain, and a compound represented by the general formula (II):

[0011]

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(Wherein, R ^{3 to} R ⁶ each have 1 to 1 carbon atoms)
An alkyl group having 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or (R ′) ₃ SiO—
(R ′ is a monovalent hydrocarbon group having 1 to 20 carbon atoms;
R ′ may be the same or different), and R ^{3 to} R ⁶ may be the same or different. R
^{When 3} or R ⁵ is present in two or more, they may be the same or different. Z is an oxygen atom,
An alkyl chain having 1 to 20 carbon atoms or an aryl chain having 6 to 20 carbon atoms is shown. m represents 0 or an integer of 1 to 18)
After the hydrosilylation reaction with the silicon hydride compound represented by the following formula, a hydrolysis reaction is preferred. According to this production method, a saturated hydrocarbon polymer having a silanol group, which has been unstable conventionally, can be produced stably.

Hereinafter, the method for producing the component (A) will be described in detail. This manufacturing method is performed in two stages, 1
In the step, a saturated hydrocarbon polymer having an unsaturated group represented by the general formula (I) is reacted with a silicon hydride compound represented by the general formula (II) in the presence of a hydrosilylation catalyst to obtain a saturated hydrocarbon. This is a step of introducing a Si-H group into the system polymer.

The skeleton of the saturated hydrocarbon polymer having an unsaturated group represented by the general formula (I) used in this step is (a) ethylene, propylene, 1-butene, isobutylene, 2-butene, C1-C6 such as 2-methyl-1-butene, 3-methyl-1-butene, pentene, 4-methyl-1-pentene, hexene, vinylcyclohexane, etc.
Polymerizing an olefinic compound as a main monomer,
(B) It can be obtained by a method such as hydrogenation of a homopolymer of a diene compound such as butadiene or isoprene, or a copolymer of the above-mentioned olefin compound and a diene compound. The isobutylene-based polymer and the hydrogenated polybutadiene-based polymer are preferred from the viewpoints of easy introduction and easy control of the molecular weight.

The term "saturated hydrocarbon-based polymer" as used herein is a concept meaning a polymer substantially containing no carbon-carbon unsaturated bond other than aromatic. In the isobutylene-based polymer, all of the monomer units may be formed from isobutylene units, and a monomer unit having copolymerizability with isobutylene is 50% by weight (hereinafter, “%”) in the isobutylene-based polymer. ), Preferably 30% or less, more preferably 10% or less. Examples of the monomer copolymerizable with isobutylene include olefins having 4 to 12 carbon atoms, vinyl ethers, aromatic vinyl compounds, vinyl silanes, allyl silanes, and the like. More specifically, methyl vinyl ether, styrene, α-methyl styrene, vinyl trichlorosilane, vinyl methyl dichlorosilane, allyl trichlorosilane, allyl dimethyl trichlorosilane and the like can be mentioned. When vinyl silanes and allyl silanes having copolymerizability with the above-mentioned isobutylene are used, the silicon content increases, the number of groups that can act as a silane coupling agent increases, and the adhesiveness of the resulting composition improves.

The polybutadiene-based polymer and other saturated hydrocarbon-based polymers also contain other monomer units in addition to the main monomer units, as in the case of the isobutylene-based polymer. May be. The number average molecular weight of the saturated hydrocarbon polymer, preferably an isobutylene polymer or a hydrogenated polybutadiene polymer is from 500 to 300.
It is preferably about 00, especially 1000 to 1500
Those having a liquidity of about 0 to a fluidity are preferable in terms of easy handling.

The method for producing a saturated hydrocarbon polymer will be described. Of the isobutylene polymers, an isobutylene polymer having a functional group at a molecular chain terminal is a polymerization method called an inifer method (initiation ability called an inifer). (Cationic polymerization method using a specific compound having a chain transfer ability), preferably an all-terminal functional isobutylene-based polymer. Such a production method is described, for example, in Japanese Patent Application No. 61-14889.
No. 5, No. 61-150088, No. 62-90078
Nos. 62-179733 and 62-194838.

The isobutylene polymer having a functional group in the molecular chain can be produced by adding the above-mentioned vinylsilane or allylsilane having a functional group to a monomer mainly composed of isobutylene and copolymerizing the same. The above-mentioned hydrogenated polybutadiene-based polymer is obtained, for example, by first converting the hydroxyl group of the terminal hydroxy-hydrogenated polybutadiene-based polymer to-
After being converted to an oxymetal group such as ONa or —OK, a general formula (III);

[0019]

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(Where Y is a halogen atom such as a chlorine atom or an iodine atom, and R ⁷ is —R ⁸ —, —R ⁸ —OCO—, —
A divalent organic group represented by R ⁸ —CO— (R ⁸ is a hydrocarbon group having 1 to 20 carbon atoms, and specific examples thereof include an alkylene group, a cycloalkylene group, an arylene group, and an aralkylene group). Is reacted to produce a hydrogenated polybutadiene-based polymer having a terminal olefin group.

Methods for converting a terminal hydroxyl group of a terminal hydroxy hydrogenated polybutadiene polymer into an oxymetal group include alkali metals such as Na and K; metal hydrides such as NaH; metal alkoxides such as NaOCH ₃ ;
A method of reacting with caustic soda or caustic alkali such as caustic potash can be used. In the above method, a terminal olefin hydrogenated polybutadiene-based polymer having substantially the same molecular weight as the terminal hydroxy-hydrogenated polybutadiene-based polymer used as the starting material can be obtained. Before reacting the organic halogen compound of (III), react with a polyvalent organic halogen compound having two or more halogen atoms in one molecule such as methylene chloride, bis (chloromethyl) benzene, bis (chloroethyl) ether, etc. By doing so, the molecular weight can be increased, and thereafter, by reacting with an organic halogen compound represented by the general formula (III), a hydrogenated polybutadiene-based polymer having a higher molecular weight and having an olefin group at a terminal can be obtained. Can be done.

Specific examples of the organic halogen compound represented by the general formula (III) include allyl chloride, allyl bromide, vinyl (chloromethyl) benzene, allyl (chloromethyl) benzene, allyl (bromomethyl) benzene, allyl (chloromethyl) Methyl) ether, allyl (chloromethoxy) benzene, 1-butenyl (chloromethyl) ether, 1-hexenyl (chloromethoxy) benzene, allyloxy (chloromethyl) benzene, and the like, but are not limited thereto. Of these, allyl chloride is preferred because it is inexpensive and easily reacts.

The introduction of the Si—H group into the saturated hydrocarbon polymer is carried out by a hydrosilylation reaction with a silicon hydride compound represented by the general formula (II). The silicon hydride compound represented by the general formula (II) is not particularly limited, but is preferably a compound having two or more Si—H groups in a molecule. On the other hand, if the hydrosilylation reaction activity is too high, all the Si-H groups react, and a polymer having silanol groups cannot be obtained. Suitable silicon hydride compounds include 1,1,3,3-tetradimethylsiloxane, 1,4-bis (dimethylsilyl) benzene,
1,1,1,3,5,7,7,7-octamethyltetrasiloxane and the like. 1,1, for easy handling
1,3,5,7,7,7-octamethyltetrasiloxane is more preferred.

Examples of the hydrosilylation catalyst used in the hydrosilylation reaction include platinum alone, alumina and silica carbon black on which solid platinum is supported.
Chloroplatinic acid, complexes of chloroplatinic acid with alcohols, aldehydes, ketones, etc., platinum-olefin complexes (for example, Pt
_{(CH 2 = CH 2) 2} (PPh 3) 2 Pt (CH 2 = CH 2) 2 C
l ₂ ); a platinum-vinylsiloxane complex (for example, Pt
_n (ViMe ₂ SiOSiMe ₂ Vi) _m , Pt [(MeVi
SiO) ₄ ] _m ), a platinum-phosphine complex (for example, Pt (P
_{Ph 3) 4, Pt (PBu} 3) 4), platinum - phosphite complex _{(e.g., Pt [P (OPh) 3} ] 4, Pt [P (OB
u) ₃ ] ₄ (where Me is a methyl group, Bu is a butyl group, V
i represents a vinyl group, Ph represents a phenyl group, and n and m represent integers), dicarbonyldichloroplatinum, and the like are useful in the present invention.

In the second step, the S obtained in the first step
This is a step of hydrolyzing a saturated hydrocarbon polymer into which an iH group has been introduced. The hydrolysis may be carried out by using a known method. For example, the reaction is carried out with a buffer solution in the presence of a Pd / C catalyst (J. Org. Chem., 31, p885 (1966)), or with a buffer solution in the presence of a platinum catalyst. A reaction method or the like can be used.

The component (B) of the curable composition of the present invention is not particularly limited as long as it is a saturated hydrocarbon polymer having at least one reactive silicon group (not containing a hydroxyl group). Here, the skeleton of the saturated hydrocarbon polymer of the component (B) is the same as that of the component (A). The reactive silicon group is not particularly limited as long as it does not contain a hydroxyl group. However, when a typical one is represented by the general formula (I)
V)

[0027]

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(Wherein R ⁹ and R ¹⁰ each have 1 carbon atom)
To 20 alkyl groups, aryl groups having 6 to 20 carbon atoms, aralkyl groups having 7 to 20 carbon atoms, or (R ′) ₃ SiO—
(R ′ is a monovalent hydrocarbon group having 1 to 20 carbon atoms;
R ′ may be the same or different), and represents a triorganosiloxy group represented by R ⁹ or R ^9
When two or more ¹⁰ are present, they may be the same or different. X represents a hydrolyzable group (excluding a hydroxyl group), and when two or more Xs are present, they may be the same or different. a is 0, 1, 2
Or 3, b is 0, 1, or 2, m is 0 or 1.
Which represents an integer from to 18).

As the hydrolyzable group represented by X,
It is not particularly limited as long as it is not a hydroxyl group, and includes a conventionally known hydrolyzable group, specifically, a hydrogen atom, a halogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, Examples include an aminooxy group, a mercapto group, and an alkenyloxy group. Among these, a hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group,
An acid amide group, an aminooxy group, a mercapto group, and an alkenyloxy group are preferred, and an alkoxy group is preferred from the viewpoint that the hydrolyzability proceeds secretly and is easy to handle.

The hydrolyzable group has 1 to 1 silicon atom.
Can be combined in three ranges, and the value of (a + b) is 1
The range of ~ 5 is preferred. When two or more hydrolyzable groups are bonded to the reactive silicon group, they may be the same or different. Specific examples of R ⁹ and R ¹⁰ in the general formula (IV) include an alkyl group such as a methyl group and an ethyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group, and an aralkyl group such as a benzyl group. And a triorganosiloxy group represented by (R ′) ₃ SiO— in which the R ′ group is a methyl group, a phenyl group, or the like. Of these, a methyl group is preferred.

At least one reactive silicon group is preferably present in one molecule of the saturated hydrocarbon polymer of the component (B), preferably 1.5.
Preferably, there are up to five. If the number of reactive silicon groups contained in the molecule is less than one, the curability will be insufficient and it will be difficult to exhibit good rubber elasticity behavior. The reactive silicon group may exist at the terminal of the molecular chain of the saturated hydrocarbon polymer of the component (B), may exist inside, or may exist at both. In particular, when the reactive silicon group is present at the molecular chain terminal, the effective network chain amount of the saturated hydrocarbon-based polymer component contained in the finally formed cured product increases, so that high strength and high elongation are obtained. It is preferable from the viewpoint that a rubber-like cured product is easily obtained. The molar ratio of the hydrolyzable group in the component (B) / the hydroxyl group in the component (A) is not particularly limited.
No.

In the present invention, a silanol condensation catalyst can be used as the component (C). Conventionally known silanol condensation catalysts can be widely used. Specific examples include titanates such as tetrabutyl titanate and tetrapropyl titanate; tin carboxylate salts such as dibutyltin dilaurate, dibutyltin malate, dibutyltin acetate, tin octylate, tin naphthenate; and dibutyltin oxide and phthalate. Reactants; dibutyltin diacetylacetonate: organoaluminum compounds such as aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminum ethylacetoacetate; zirconium tetraacetylacetonate;
Chelating compounds such as titanium tetraacetylacetonate; lead octylate; butylamine, octylamine dibutylamine, monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine, benzylamine, diethylaminopropylamine; Xylylenediamine, triethylenediamine, guanidine, diphenylguanidine, 2,4,6-tris (dimethylaminomethyl) phenol, morpholine, N
Amine compounds such as -methylmorpholine, 2-ethyl-4-methylimidazole and 1,8-diazabicyclo (5,4,0) undecene-7 (DBU) or salts thereof with carboxylic acids or the like; Low molecular weight polyamide resin obtained from polybasic acid; reaction product of excess polyamine and epoxy compound; silane coupling agent having amino group, for example, γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) Examples include silanol condensation catalysts such as aminopropylmethyldimethoxysilane, and other known silanol condensation catalysts such as other acidic catalysts and basic catalysts. These catalysts may be used alone or in combination of two or more.

The composition of the present invention further comprises a plasticizer, an adhesion improver, a physical property modifier, a storage stability improver, a filler, a sulfur-based antioxidant, an ultraviolet absorber, a metal deactivator, Various additives such as an ozone deterioration inhibitor, a light stabilizer, an amine-based radical chain inhibitor, a phosphorus-based peroxide decomposer, a lubricant, a pigment, and a foaming agent can be appropriately added.

[0034]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the invention thereto. Example 1 a) Synthesis of polyisobutylene having a silanol group Synthesis Example 1 Polyisobutylene having an unsaturated group (molecular weight: about 5000) 10 according to the method described in Japanese Patent Application No. 1-144634.
In 0 g, 1,1,1,3,5,7,7,7-octamethyltetrasiloxane was added with an unsaturated group having an Si-H group of 1.
2 equivalents of H ₂ PtCl ₆ (10% methanol solution) was added to give 5 × 10 ⁻⁴ equivalents to the unsaturated group, and 70 ° C.
For 6 hours. 80 g of the obtained polymer
3. 0.5 g of Pd / C, buffer solution (pH 6.8)
5 ml, dioxane 50 ml, n-hexane 100 ml
Was added and reacted at 60 ° C. for 80 hours. The obtained polymer was polyisobutylene having a silanol group from IR and NMR.

B) Synthesis of polyisobutylene having methyldimethoxysilyl group Synthesis Example 2 Tricumyl chloride is polymerized with isobutylene using boron trichloride as a catalyst, and then dehydrochlorinated. 200 g of an isobutylene polymer having a propenyl group and a molecular weight of about 5000 and 10 g of toluene were collected in a 500 ml four-necked flask,
Degassed under reduced pressure at 0 ° C. for 2 hours. Next, 120 ml of dry heptane and methyldichlorosilane at room temperature under a nitrogen atmosphere.
5 g and chloroplatinic acid catalyst solution 0.1 ml (H ₂ PtCl ₆
・ 1 g of 6H ₂ O was dissolved in 9 g of 1,2-dimethoxyethane and 1 g of ethanol), and the mixture was reacted at 90 ° C. for 12 hours. When the amount of the remaining isopropenyl group of the isobutylene-based polymer in the reaction solution was quantified by IR spectroscopy, it was found that there was almost no residual.
Then 21.2 g of methyl orthoformate and 6.4 g of methanol
And reacted at 70 ° C. for 3 hours. At this time, the pH of the reaction system became about 7, and became neutral. After the volatile components were distilled off under reduced pressure, 50 ml of hexane was added to the remaining components, and the mixture was stirred well, and the insoluble components were removed by filtration. By distilling off hexane from the filtrate, the both ends _{-Si (CH 3) (OCH 3} ) 2
An isobutylene-based polymer having a group was obtained. As a result of NMR analysis of the obtained polymer, about 80% of molecular terminals were-
It was found that Si (CH ₃ ) (OCH ₃ ) ₂ groups had been introduced.

C) The silanol-terminated polyisobutylene-based polymer obtained in Synthesis Example 1 and the methyldimethoxysilyl-terminated polyisobutylene-based polymer obtained in Synthesis Example 2 are blended in the ratio shown in Table 1 and sufficiently stirred. To prepare a homogeneous composition. The resulting composition was cast into a sheet having a thickness of 3 mm, cured at room temperature for 4 days, and then aged at 50 ° C. for 4 days. After observing the curing state of the obtained sheet, the tensile properties of the cured product were measured. Table 1 shows the results.

[0037]

[Table 1]

Example 2 d) The silanol-terminated polyisobutylene polymer obtained in Synthesis Example 1 and the methyldimethoxysilyl-terminated polyisobutylene polymer obtained in Synthesis Example 2 were blended in the ratio shown in Table 2. And sufficiently stirred to prepare a homogeneous composition. The resulting composition was cast into a plate having a thickness of about 1 cm, cured at room temperature for 4 days, and then aged at 50 ° C. for 4 days. The obtained cured product was cut, and the center of the cut surface was touched with the tip of a toothpick. Table 2 shows the results.

[0039]

[Table 2]

[0040]

The curable composition of the present invention has excellent weather resistance, heat resistance, water resistance and moisture barrier properties, remarkably excellent strength and elongation properties, and also has excellent deep section curability. Can be obtained. Further, since the polymer used as the component (A) or the component (B) in the present invention contains a reactive silicon group, various adherends such as glass, aluminum, natural rubber, butyl rubber, epoxy resin, It can be adhered to various substrates such as acrylic resin, vinyl chloride resin, nylon, and galvanized iron, and can have good water resistance, heat resistance and the like. Therefore, the composition of the present invention is suitably used as a sealant composition such as an adhesive, a pressure-sensitive adhesive, a paint, a sealing agent for double-glazing, a waterproofing agent, a spraying agent, a molding material, a cast rubber material, and the like. Can be done.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-196842 (JP, A) JP-A-1-252670 (JP, A) JP-A-4-13767 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C08L 1/00-101/16

Claims (3)

(57) [Claims] 1. A lower Symbol (A), (B), (C) a curable composition consisting of components; (A) has a hydroxyl group bonded to a silicon atom, silicon which can be crosslinked by forming a siloxane bond A saturated hydrocarbon polymer having at least one atom in the molecule, (B) a silicon atom having a hydrolyzable group (excluding a hydroxyl group) bonded to a silicon atom and capable of crosslinking by forming a siloxane bond; (C) a silanol condensation catalyst having at least one saturated hydrocarbon polymer per molecule. 2. A saturated hydrocarbon polymer wherein the main chain skeleton of the saturated hydrocarbon polymer in the component (A) is selected from the group consisting of polyisobutylene, hydrogenated polyisoprene, hydrogenated polybutadiene, and copolymers thereof. The curable composition according to claim 1 , which is: 3. A saturated hydrocarbon polymer wherein the main chain skeleton of the saturated hydrocarbon polymer in the component (B) is selected from the group consisting of polyisobutylene, hydrogenated polyisoprene, hydrogenated polybutadiene and copolymers thereof. Claim 1 or
Is the curable composition according to 2.