JP3155035B2 - 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 room temperature curable composition which cures in the presence of moisture.

[0002]

2. Description of the Related Art Hitherto, a method of curing various compounds having a hydrolyzable silicon group at a terminal and using them in sealing materials, adhesives and the like is well known and industrially useful.

[0003] Among such compounds, particularly those having a main chain of polyether are liquid at room temperature, and the cured product retains flexibility even at a relatively low temperature, and is used as a sealing material, an adhesive or the like. In some cases, it has favorable characteristics.

[0004] Such moisture-curable compounds include :
JP 3-72527 and JP-A-3-4782
The end that is described in No. 5 Publication compounds of moisture curable having hydrolyzable silicon groups can be mentioned up. In such a compound having a hydrolyzable silicon group at the terminal, generally, as the molecular weight increases, the flexibility of the cured product increases, but the viscosity of the compound becomes high, and the workability is remarkably deteriorated.

[0005] When the molecular weight of such a compound is small, the viscosity is low, but the cured product is inferior in flexibility.
You . Until now, various plasticizers have been used to reduce the viscosity while maintaining the flexibility of the cured product.

[0006] Such plasticizers include aromatic carboxylic esters, aliphatic carboxylic esters, glycol esters, phosphate esters, epoxy plasticizers,
Chlorinated paraffin is used. However,
Since these plasticizers have a migration property, when used as a sealing material or the like, there is a drawback that contamination around the sealing portion and adversely affect adhesiveness.

[0007]

Therefore, it is possible to reduce the viscosity of a composition containing a compound with respect to a moisture-curable compound having a hydrolyzable silicon group without lowering its flexibility. In addition, as a result of studying additives having extremely low migration properties, the present invention was achieved.

[0008]

That is, according to the present invention, a polyether having a main chain having a molecular weight of 8,000 to 50,000 having an average of 1.5 or more hydrolyzable silicon groups in the molecule is provided.
Le is a hydrolyzable silicon group-containing high polymer (I) and for that 100 parts by weight of the polymer, molecular weight having an average of less than 0.5 to 1.5 hydrolyzable silicon group in a molecule Hydrolyzable silicon group-containing low molecular weight compound (II) 1 to 20 in which the main chain of 300 or more and less than 8000 is a polyether.
It is a room temperature curable composition containing 0 parts by weight.

The polymer (I) containing a hydrolyzable silicon group used in the present invention has an average of 1.5 or more hydrolyzable silicon groups in the molecule, and has a molecular weight of 8,000 to 50,000. is a compound that cures in the presence room temperature, the main chain ing essentially of polyether.

[0010] hydrolyzable silicon group-containing high molecular weight polymer (I) of the present invention is obtained by introducing a hydrolyzable silicon group at an end in a suitable manner to the polyether le terminal hydroxyl groups.

Such a polymer is disclosed, for example, in JP-A-3-4
No. 7825, JP-A-3-72527, JP-A-3-79627, JP-B-46-30711, JP-B-45-36319, and JP-B-46-17.
No. 553, for example.

The polymer (I) containing a hydrolyzable silicon group is produced by introducing a hydrolyzable silicon group into the terminal of a polyether compound having a functional group as described below .

[0013] The polyether compound is an alkali metal catalyst, a double metal cyanide complex catalyst, a metal porphyrin catalyst.
Those having terminal hydroxyl groups prepared by reacting such monoepoxide to an initiator such as hydroxy compounds having at least one hydroxyl group presence of a catalyst such as medium and alkylene oxide are preferred. The number of functional groups in the polyether compound is 2
The above is preferable, and 2 or 3 is particularly preferable.

[0014] Polyether compounds, specifically polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxyethylene hexylene, polyoxytetramethylene and copolymers thereof are exemplified up.

Particularly preferred polyether compounds are polyoxypropylene diol and polyoxypropylene triol. When used in the following methods (1) and (4), olefin-terminated polyether compounds such as allyl-terminated polyoxypropylene monol can also be used.

Examples of the hydrolyzable silicon group in the present invention, silicon group hydrolysis and crosslinking reactions in moisture occurs der
Re Bayoku, commonly known hydrolyzable silicon groups can be used.

For example, a silicon group represented by the general formula (A) is preferable. -SiX _a R _3-a ... (A)

[0018] R in the formula is a monovalent organic group substituted or unsubstituted 1 to 20 carbon atoms, preferably an alkyl group, a phenyl group or a fluoroalkyl group having 8 or less carbon atoms. Particularly preferred are a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, a cyclohexyl group, a phenyl group and the like.

[0019] X is a hydrolyzable group, eg if a halogen atom, an alkoxy group, an acyloxy group, an amide group, an amino group, an amino group, there are etc. ketoximate group.

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, especially methoxy group, ethoxy group, propoxy group,
Examples thereof include a propenyloxy group. a is 1, 2 or 3, and particularly preferably 2 or 3.

The method of the introduction of the general formula (A) to the polyether compound of silicon groups table particularly without limitation, may be introduced, for example, by the following method.

(1) A polyether compound having a functional group having an olefin group introduced into a terminal thereof, and a compound represented by the general formula (B):
A method of reacting a silicon hydride compound represented by the formula: HSiX _a R _3-a (B) (wherein R, X and a are the same as above)

[0023] As a method for introducing wherein olefinic groups, a compound having an unsaturated group and a functional group is reacted at the terminal hydroxyl groups of the polyether compound, an ether bond, an ester bond, a urethane bond, such as by carbonate bond methods of coupling, or when polymerizing alkylene oxide, such as a method of introducing an olefin group in the side chain are exemplified by copolymerization by adding an olefin group-containing epoxy compound such as allyl glycidyl ether.

(2) A method of reacting a compound represented by the general formula (C) with a terminal of a polyether compound having a functional group. ^{_{R 3-a -SiX a -R 1}} NCO ··· (C) ( same .R ¹ wherein R, X, a is the 1 to 17 carbon atoms
Divalent hydrocarbon group. )

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

R _3-a -SiX _a -R ¹ W (D) (wherein R, R ¹ , X and a are the same as above. W is a hydroxyl group, a carboxyl group, a mercapto group and an amino group (1 Active hydrogen-containing group selected from primary or secondary).)

(4) An olefin group is introduced into the terminal of the polyether compound having a functional group,
A method of reacting a mercapto group of a silicon compound represented by the general formula (D) wherein W is a mercapto group.

The hydrolyzable silicon groups on average in the molecular hydrolyzable silicon group-containing high polymer (I) 1.5 to 8
In particular, it is preferably 1.6 to 4.

The hydrolyzable silicon group-containing high polymer (I) of the present invention, molecular weight 8000 to 5000
0 following organic polymer Ru is used. In particular, when the molecular weight of the organic polymer is lower than 8,000, the elongation of the cured product is low, and when the molecular weight is higher than 50,000, the workability is remarkably deteriorated due to the high viscosity. Most preferred molecular weight is 10000 to 40,000.

[0030] In the present invention, the hydrolyzable silicon group-containing high polymer relative to (I), on average in the molecule 0.5
A low-molecular compound (I) having a hydrolyzable silicon group of less than
I) is used as a non-migratory reactive thickener and plasticizer.

As a method for producing such a low molecular weight compound (II) containing a hydrolyzable silicon group, a monofunctional initiator is used to carry out ring-opening polymerization of an alkylene oxide to obtain a polyether monool. It is manufactured by a method of converting into a hydrolyzable silicon group by the methods (1) to (4).

The polyether monol has 1 to 2 carbon atoms.
It is obtained by subjecting an alkylene oxide to ring-opening polymerization by the known method using an aliphatic, alicyclic or aromatic alcohol, thioalcohol, secondary amine, carboxylic acid or the like as an initiator.

[0033] When introducing methods hydrolyzable silicon group of the (1) and (4) may be used polyether monool prepared monol as an initiator having an unsaturated group such as allyl alcohol In this case, the terminal hydroxyl group may be converted to an inert organic group by a method such as reaction with benzoyl chloride.

The hydrolyzable groups in the low molecular weight compound (II) of use hydrolyzable silicon group-containing to the present invention is the average of less than 0.5 and less than 1.5 in the molecular <br/>, especially 0.5 or less
The upper limit is preferably 1.2 or less .

The molecular weight of the low molecular compound of hydrolyzable silicon group-containing used in the present invention (II) is less than 300 or 8000. When the molecular weight of the compound is 8000 or more,
Effect as a viscosity-reducing agent is that a low. Especially 300 or more and 600
0 or less is preferable. The most preferred molecular weight is from 2,000 to 4,000.

In the present invention, 1 to 200 parts by weight of the low molecular weight compound (II) containing a hydrolyzable silicon group is used based on 100 parts by weight of the polymer (I) containing a hydrolyzable silicon group. Preferably 1 to 100 parts by weight, particularly preferably 1 to 100 parts by weight
80 parts by weight.

The composition of the present invention may contain various known curing catalysts, fillers, additives and, if necessary, a plasticizer.

As the curing catalyst, various metal carboxylate salts , acetylacetonate complexes, acetoacetate esterate complexes, various acid and base substances can be used. Specifically, tin octylate, lead octylate, dialkyltin carboxylates, metal salts such as dibutyltin bis-acetyl acetonate, organic amines are exemplified up. These catalysts can be used alone or in combination.

[0039] As fillers, fumed silica, precipitated silica, fillers such as silicic anhydride, hydrous silicic acid, carbon black, calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite Fillers such as organic bentonite, ferric oxide, zinc oxide, activated zinc white, hydrogenated castor oil , shirasu balloon , and fibrous fillers such as asbestos, glass fiber , and filaments can be used.

As the plasticizer, dioctyl phthalate,
Dibutyl phthalate, butyl benzyl phthalate phthalates and the like; dioctyl adipate, isodecyl succinate, dibutyl sebacate, fatty acid esters such as butyl oleate; polio Ruesuteru such as pentaerythritol ester; trioctyl phosphate,
Phosphate esters such as tricresyl phosphate; epoxidized soybean oil, epoxy plasticizers such as benzyl epoxystearate; chlorinated paraffins and the like can be used alone or as a mixture of two or more.

[0041] As additives, phenolic resins, adhesion imparting agents such as an epoxy resin, pigments, various antioxidants, ultraviolet absorbers, etc. can be mentioned up. The room temperature curable resin composition of the present invention can be used particularly for an elastic sealant and an adhesive.

[0042]

EXAMPLES Reference Examples (Examples 1 to 3) and Examples of the present invention will be described below.
(Examples 4-6), elevation gel Comparative Example (Example 7-8) is not intended to be limited thereto. [ Example 1] Starting from 2-ethylhexanol as an initiator,
No. 2527, a propylene oxide is reacted in the presence of a double metal cyanide complex catalyst to produce polyoxypropylene monol, and then a salt is added to the terminal hydroxyl group.
After introducing an unsaturated group is reacted with allyl, further reacted with methyldimethoxysilane, a main chain of polyoxypropylene, Additive A molecular weight 3200 having a methylation dimethoxy silyl propyl group as terminal groups Synthesized. Additive A had a viscosity of 620 cP at 25 ° C.

Example 2 Using 2-ethylhexanol as an initiator, propylene oxide was subjected to ring-opening polymerization in the presence of a double metal cyanide complex catalyst to obtain a polyoxypropylene monol having a molecular weight of 3000. Additive B was synthesized by reacting with an equimolar amount of methyldimethoxysilylpropyl isocyanate. Additive B has a viscosity of 750 cP at 25 ° C.
Met.

Example 3 Propylene oxide was subjected to ring-opening polymerization using allyl alcohol as an initiator to obtain a polyoxypropylene monol having a molecular weight of 2,000 and having an allyloxy group at one terminal. Reacted with benzoyl. The reaction mixture was diluted with five times the amount of hexane and washed with water to remove triethylamine hydrochloride. The hexane was distilled off, and one end was a benzoyloxy group and the other end was a benzoyloxy group.
A compound having an allyl group at the end was obtained. Next, by the usual method,
By reacting with chloroplatinic acid as a catalyst and methyldimethoxysilane to convert an allyl group to a methyldimethoxysilylpropyl group, an additive C having a molecular weight of 2200 was synthesized. Additive C had a viscosity of 700 cP at 25 ° C.

Examples 4 to 6 The terminal of polyoxypropylene triol obtained by reacting propylene oxide with glycerin as an initiator in the presence of a double metal cyanide complex catalyst has an average molecular weight of 2.
Four to silicon group-containing polyoxypropylene polyether compound 100 parts by weight of molecular weight 30000 was introduced methyldimethoxysilylpropyl group, dibutyltin additives A~C each <br/> as 30 parts by weight and a curing catalyst dilaurate 1 part by weight, the addition of phenolic antioxidant 1 part by weight as an additive, a homogeneous mixture, the viscosity before curing, physical properties after curing (50% modulus, breaking strength, elongation), and curing The weight change (weight loss rate) when the product was immersed in the solvent was measured.

[0046] [Example 7-8] Instead of the additive A~C in Examples 4-6, containing no additives, as a and additives dioctyl phthalate (DO
The same study as in Examples 4 to 6 was conducted for those containing P). Table 1 shows the obtained results.

[0047]

[Table 1]

[0048]

According to the present invention, the viscosity of a composition containing a compound can be reduced without lowering the flexibility of a moisture-curable compound having a hydrolyzable silicon group. Moreover, since the additives used in the present invention have very low migration properties, when the composition of the present invention is used as a sealing agent or the like, there is no possibility of contaminating around the sealing portion or adversely affecting the adhesiveness.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08L 1/00-101/16

Claims (2)

(57) [Claims] 1. A molecular weight of 8000 to 50,000 in the main with 1.5 or more hydrolyzable silicon groups on average in the molecule
The hydrolyzable silicon group-containing high molecular polymer (I) having a polyether chain and the hydrolyzable silicon group having an average molecular weight of 0.5 to less than 1.5 based on 100 parts by weight of the polymer. A room temperature curable composition comprising 1 to 200 parts by weight of a hydrolyzable silicon group-containing low molecular weight compound (II) having a main chain of a polyether having a molecular weight of 300 or more and less than 8000 having 2. The room temperature curable composition according to claim 1, wherein the hydrolyzable silicon groups of the high molecular polymer (I) and the low molecular compound (II) are represented by the following general formula (A). —SiX _a R _3-a (A) (wherein R is a substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms, X is a hydrolyzable silicon group, and a is 1, 2 or 3) Is shown.)