JP3186848B2 - Room temperature curable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a room temperature curable composition which cures in the presence of moisture.

[0002]

2. Description of the Related Art Conventionally, a method of using a compound having a hydrolyzable silicon group at a terminal, such as a modified silicone resin, by utilizing a curing reaction of the compound for a sealing material, an adhesive or the like is often used. It is a known and industrially useful method.

[0003]

Among the compounds having a hydrolyzable silicon group at the terminal [0005], in particular a hydrolyzable silicon group
In the case of using a compound having an A alkoxysilyl group, in order to impart temperature-curable, it is common practice to use so-called cure catalyst.

[0004] Such curing catalysts, metal salt of carboxylic acid, such as acidic or basic compounds are known, carboxylate or other organic tin compound of tin Among
Things are common.

However, dibutyltin dilaurate, dibutyltin Geographic click Tano benzoate, a tetravalent organotin compounds such as dibutyltin diacetate, when used as a curing catalyst of a compound having an alkoxysilyl group as a hydrolyzable silicon group, the curing reaction There were drawbacks such as being slow and the cured product having poor compression set.

On the other hand, if a divalent tin carboxylate such as tin 2-ethylhexanoate is used as a curing catalyst, curing is quick and the compression set is improved, but the tin compound itself is not cured. Due to low moisture stability,
Particularly sealants one-part there is difficulty Iketsu point used.

[0007] Furthermore, the use of sealing materials and the like in winter is
Assuming that the speed of the curing reaction at low temperatures is also importantBecome
However, this point is not particularly true with these conventional curing catalysts.
It was enough.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve such a drawback, and has at least one compound in a molecule.
The silicon-containing polymer (A) having two hydrolyzable silicon groups and 100 parts by weight thereof were used as curing catalysts of the formula (1)
It is a room temperature curable composition containing 0.01 to 10 parts by weight of the organotin compound (B) represented by the formula: Y-Sn (R ¹ ) (R ² )-[O-Sn (R ¹ ) (R ² )] _n -Z (1) (wherein R ¹ and R ² are 1 to 20 carbon atoms) valent hydrocarbon group .Y, Z is a two radicals different, each carbon number 1
Or a monovalent organic group having a moiety capable of coordinating to Sn in the molecule. n is an integer of 0-10. )

In the present invention, the organotin compound (B) used together with the silicon-containing polymer (A) is represented by the above formula (1)
It is a compound represented by these.

[0010] The compounds known as silicon group-containing organic polymer of the catalyst described in JP-A-61-141761,
There is a compound represented by the formula (3) or the formula (4). For these compounds, the rate of the curing reaction at room temperature was significantly improved, but the rate at low temperatures was still inadequate. _{Q 2 Sn (OT) 2 ···} (3) [Q 2 Sn (OT)] 2 O ··· (4) (Q is a monovalent hydrocarbon group having 1 to 20 carbon atoms .T 1 carbon atoms To 20 monovalent hydrocarbon groups or organic groups having a moiety capable of coordinating with Sn in the molecule.)

[0011] Y In the present invention bound to the Sn in equation (1), Z is different from the required conditions, the curing rate at low temperatures Ru significantly improved by using organic tin compound (B). Organotin compound in its reasons are not clear the onset light for the structure of (B) is sufficiently exhibited catalytic activity even at low temperatures reduces the crystallinity in order to be asymmetrical, also silicon-containing polymer (A) It is considered that the solubility of the compound increases.

In particular, a combination in which one of Y and Z is a monovalent organic group having a moiety capable of coordinating to Sn in the molecule and the other is an alkoxy group, and one of Y and Z is A combination in which the alkoxy group has a high molecular weight and the other is an alkoxy group having a low molecular weight is preferable.

R ¹ and R ² in the formula (1) each have ¹ to ² carbon atoms.
0 is a monovalent hydrocarbon group. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, and a phenyl group. A methyl group, a butyl group, and an octyl group are preferable in terms of economy.

Y and Z in the formula (1) are an alkoxy group having 1 to 20 carbon atoms or a monovalent organic group having a moiety capable of coordinating with Sn in the molecule. Specifically, methoxy, n- butoxy, n- octyl group, a 2-ethylhexyl group, n- dodecyloxy group of which alkoxy group, an acetyl acetonate group, propionyl acetonate group, 2-aminoethoxy group, Examples of the organic group include a coordinating organic group such as a 3-aminopropoxy group, a 3- (N, N-dimethylamino) propoxy group, and a 3-mercaptopropoxy group.

As Y and Z, two different groups selected from these groups are used. Y, when Z is any alkoxy radical, Y, one is an alkoxy group on the number of 4 or more carbon atoms other Z is an alkoxy group having 3 hereinafter carbons, the difference in the number of carbon atoms in both It is preferably 2 or more, especially 4 or more. The above acetylacenate group, propionyl aceto
The nath groups are represented by formulas (5) and (6), respectively. This
Of the carbonyl groups are considered to coordinate with Sn
Has been obtained.

[0016]

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In the formula (1), n is an integer of 0 to 10.
The larger the value of n, the higher the activity as a catalyst, but the more difficult it is for the organotin compound (B ) to dissolve in the silicon-containing polymer (A) . n is particularly preferably 7 or less.

In the present invention, the above-mentioned organotin compound (B)
With 0.01 to 100 parts by weight of the silicon-containing polymer (A) having at least one hydrolyzable silicon group in the molecule.
Use up to 10 parts by weight. Preferably it is 0.1 to 3 parts by weight.

In the present invention, the silicon-containing polymer (A) having at least one hydrolyzable silicon group in the molecule is:
A hydrolysis reaction and a cross-linking reaction occur due to moisture, and the rubber-like elastic material is changed.

Such moisture-curable compounds include:
Many compounds have been studied so far, for example, JP-A-3-47820, JP-A-3-72527, JP-A-3-79627, and JP-B-46-307.
No. 11, JP-B-45-36319, JP-B-4
It has been proposed in, for example, JP-A-6-17553.

The silicon-containing polymer (A) used in the present invention comprises:
As described below, those having a main chain composed of polyoxyalkylene are particularly preferred. Such a compound is produced , for example, by introducing a hydrolyzable silicon group into a terminal of a polyoxyalkylene compound having a functional group. Such a compound is liquid at room temperature, and the cured product retains flexibility even at a relatively low temperature, and has preferable characteristics when used as a sealing material, an adhesive or the like.

The polyoxyalkylene compound is prepared by reacting a monoepoxide such as an alkylene oxide with an initiator such as a hydroxy compound having at least one hydroxyl group in the presence of a catalyst such as an alkali metal catalyst, a double metal cyanide complex catalyst, and a metal porphyrin. Hydroxyl-terminated ones produced by the above method are preferred. The number of functional groups of the polyoxyalkylene compound is preferably 2 or more, and particularly preferably 2 or 3.

Specific examples of the polyoxyalkylene compound include polyoxyethylene compounds, polyoxypropylene compounds, polyoxybutylene compounds, polyoxyhexylene compounds, polyoxytetramethylene compounds and / or copolymers thereof. Can be

Particularly preferred polyoxyalkylene compounds are polyoxypropylene compounds, and specifically, polyoxypropylene diol and polyoxypropylene triol are preferred. When used in the following methods (a) and (d), a polyoxyalkylene compound having an unsaturated group terminal such as an allyl-terminated polyoxypropylene monol can also be used.

The hydrolyzable silicon group in the present invention may be any silicon group that undergoes hydrolysis and cross-linking reaction in the presence of moisture to form a siloxane bond, and generally known hydrolyzable silicon groups are used. it can.

For example, a silyl group represented by the formula (2) is preferable. ^{_{-SiX a R 3 3-a ···}} (2)

[0027] In R ³ formula is a monovalent hydrocarbon radical or halogenated hydrocarbon radical, preferably having 1 to 20 carbon atoms, more
It is preferably an alkyl group having 8 or less carbon atoms, a phenyl group or a fluoroalkyl group. Particularly preferably, a methyl group, an ethyl group, a propyl group, blanking butyl group, a hexyl group, a cyclohexyl group, a phenyl group.

X is a hydrolyzable group,An exampleFor example, halogen
Atom, alkoxy group, acyloxy group,Carbamoyl
Group, amino group, aminooxy group, ketoximateBasicTh
There is.

Of these, the number of carbon atoms of the hydrolyzable group having a carbon atom is preferably 6 or less, particularly preferably 4 or less. Preferred hydrolyzable groups are lower alkoxy groups having 4 or less carbon atoms, particularly methoxy , ethoxy, propoxy ,
Do etc. can be exemplified. a is 1, 2 or 3, and particularly preferably 2 or 3.

The method of the introduction into the polyoxyalkylene compound silyl group represented by the formula (2) is not particularly limited, cut with introduced, for example, by the following method.

(A) A method of reacting a polyoxyalkylene compound having a functional group with an unsaturated group introduced at a terminal thereof with a hydrosilyl compound represented by the formula (7). ^{_{HSiX a R 3 3-a ···}} (7) ( wherein R ^3, X, a are as defined above.)

Here, as a method for introducing an unsaturated group,
By reacting a compound having an unsaturated group and a functional group with a terminal hydroxyl group of a polyoxyalkylene compound, an ether bond,
An ester bond, a urethane bond, a method of bonding such as by carbonate bond, or when polymerizing alkylene oxide, an unsaturated group into the side chain by copolymerization by addition of an unsaturated group-containing epoxy compound such as allyl glycidyl ether The method of introduction is mentioned.

(B) A method of reacting a compound represented by the formula (8) with a terminal of a polyoxyalkylene compound having a functional group. R ³ _3-a SiX _a -R ⁴ NCO (8) (wherein R ³ , X and a are the same as above. R ⁴ has 1 to 1 carbon atoms)
7 divalent hydrocarbon group. )

(C) A polyisocyanate compound such as tolylene diisocyanate is reacted with the terminal of the polyoxyalkylene compound having a functional group to form an isocyanate group terminal, and the silicon compound represented by the formula (9) is added to the isocyanate group. Reacting the W group of

R ³ _3-a SiX _a -R ⁴ W (9) (wherein R ³ , R ⁴ , X and a are the same as above. W is a hydroxyl group,
An active hydrogen-containing group selected from a carboxyl group, a mercapto group and an amino group (primary or secondary). )

(D) An unsaturated group is introduced into the terminal of the polyoxyalkylene compound having a functional group, and the unsaturated group is
A method of reacting a mercapto group of a silicon compound represented by the formula (9) wherein W is a mercapto group.

The number of hydrolyzable silicon groups is preferably 50% or more, and more preferably 70% or more, in all terminal groups on average.

The molecular weight of the silicon-containing polymer (A) of the present invention is not particularly limited. For example, a compound having a molecular weight of 2000 or more can be used. Preferably the molecular weight is 8,000 to 50,000
The polymer can be used. When the molecular weight of the polymer is lower than 8000, the cured product is hard and has low elongation. When the molecular weight exceeds 50,000, the flexibility and elongation of the cured product are not problematic, but the viscosity of the polymer itself is extremely large. <br/> Ri Na, practicality is reduced. The molecular weight is especially 10,000 to 3
0000 is preferred.

Further, if the viscosity of the organic tin compounds (B) in the present invention is to be high or semi-solid Ru can also be diluted with a suitable diluent. As such a diluent, various solvents commonly used and compounds known as plasticizers can be used.

Examples of such compounds include phthalic esters such as dioctyl phthalate, dibutyl phthalate and butylbenzyl phthalate; and aliphatic carboxylic acids such as dioctyl adipate, isodecyl succinate, dibutyl sebacate and butyl oleate. ester; polio Ruesuteru such as pentaerythritol ester; trioctyl phosphate, phosphoric acid esters such as tricresyl phosphate, epoxy soybean oil, epoxy plasticizers such as epoxy stearic acid benzyl; and chlorinated paraffins either alone or two or more Can be used in mixtures.

The composition of the present invention may further contain various known fillers and additives. As a filler,
Fillers such as fumed silica, precipitated silica, silicic anhydride, hydrous silicic acid and carbon black, calcium carbonate,
Magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, acid ferric, zinc oxide, activated zinc white, fillers such as hydrogenated castor oil and shirasu balloons, asbestos, such as glass fibers and filaments Fibrous fillers can be used.

As the additive, an adhesion imparting agent such as a phenol resin and an epoxy resin, a pigment, various antioxidants, an ultraviolet absorber and the like can be used.

The room temperature curable group composition as the present invention can be used in particular for elastic sealants, as adhesives.

[0044]

EXAMPLES Examples of the present invention are shown below, but the Lena have limited thereto.

Examples 1 to 3 100 parts by weight of a polyoxypropylene polymer having an average molecular weight of 20,000 having a methyldimethoxysilylpropyl group at 90% of both ends of the molecular chain, and calcium carbonate 130
Parts by weight, titanium oxide 20 parts by weight, dioctyl phthalate 2
0 parts by weight, 5 parts by weight of hydrogenated castor oil, and 1 part by weight of a phenolic antioxidant are kneaded under the condition that moisture does not enter.
One part by weight of the organotin compound A of formula (0), the organotin compound B of formula (11), or the organotin compound C of formula (12) was added and mixed well. The mixture was bisected, and one was left at room temperature to see the cured state after 1 hour and 2 hours. On the other hand saw cured state and after 12 hours was allowed to stand for 6 hours under 5 ° C..

[0046]

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Comparative Examples 1 to 3 Dibutyltin dilaurate (organotin compound D) was used instead of the organotin compounds A, B or C in the above examples.
Dibutyltin di methoxide (organic tin compound E) or dibutyltin bis acetylacetonate (organotin compound F) using 1 part by weight, likewise viewed cured state at room temperature and at 5 ° C.. The results are shown in Table 1 together with the examples. However,
The evaluation of the cured state is as follows. ：: Completely cured without stickiness. ：: Almost completely cured, with little stickiness. Δ: Hardening is advanced, but stickiness is large. X: Poor curing.

[0048]

[Table 1]

[0049]

The curing catalyst used in the present invention is excellent as a curing catalyst for a room temperature curable composition containing a polymer containing a hydrolyzable silicon group as a main component. composition than using hardens faster, particularly curing of the composition at low temperatures have a quick diplomatic fruit.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 1/00-101/16 C08K 3/00-13/08

Claims (2)

(57) [Claims] 1. A silicon-containing polymer (A) having at least one hydrolyzable silicon group in a molecule and 100 parts by weight of the same, an organotin compound (B) represented by the formula (1) as a curing catalyst. ), Which is 0.01 to 10 parts by weight. Y-Sn (R ¹ ) (R ² )-[O-Sn (R ¹ ) (R ² )] _n -Z (1) (wherein R ¹ and R ² are 1 to 20 carbon atoms) valent hydrocarbon group .Y, Z is a two radicals different, each carbon number 1
Or a monovalent organic group having a moiety capable of coordinating to Sn in the molecule. n is an integer of 0-10. ) 2. A silicon-containing polymer (A) is, molecular weight 8000
50000 a is and the main chain or polyoxyalkylene
The room temperature curable composition according to claim 1, which is a compound consisting of: