JPH05287189A - Curable composition - Google Patents

Abstract

PURPOSE:To provide the curable composition having a low viscosity, good in workability, and useful for sealants, adhesives, etc., which comprises a reactive silicon group-containing oxyalkylene polymer and an oxyalkylene polymer having a specific number-average mol.wt. and a specified mol.wt. distribution. CONSTITUTION:The objective curable composition comprises (A) an oxyalkylene polymer containing at least one reactive silicon group in the molecule and prepared by reacting an oxypropylene polymer having allyl ether groups at the molecular ends in an amount of 97% of the whole molecular ends and having an average mol.wt. of approximately 8000 with methyldimethoxysilane in a chloroplatinic acid catalyst solution and (B) an oxyalkylene polymer having a number-average mol.wt. of >=3000 and a mol.wt. distribution Mw/Mn (weight- average mol.wt./number-avrerage mol. wt.) of <=1.5. The curable composition has good workability owing to its viscosity, and gives cured products permitting to be coated with alkyd coatings under ordinary conditions and subsequently dried, and can form good alkyd coating films.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an oxyalkylene system having a reactive silicon group (a silicon atom-containing group containing a silicon atom to which a hydroxyl group or a hydrolyzable group is bonded and capable of forming a siloxane bond). The present invention relates to a curable composition containing a polymer and a high molecular weight oxyalkylene polymer.

[0002]

2. Description of the Related Art An oxyalkylene polymer having a reactive silicon group is cured at room temperature even by moisture in the air like a room temperature curable silicone rubber to form a rubber-like material. It is a polymer to give. Since this cured product has excellent elongation properties, strength, adhesiveness, etc.,
Used for sealants, adhesives, etc.

One of the characteristics of this reactive silicon group-containing oxyalkylene polymer is that the main chain is an oxyalkylene polymer, so that it is
This has the advantage that most commonly used paints can be applied to the surface of the cured product. (In the case of silicone rubber, the surface is water and oil repellency, and it is impossible to actually apply a paint.) However, even with a cured product using an oxyalkylene polymer having a reactive silicon group However, when an alkyd-based paint is applied on top of this, the drying property of the coating film is poor and there is a problem that it is actually difficult to use the paint for the cured product.

As a result of repeated studies on the cause of the deterioration of the drying property of the alkyd paint, the present inventors have found that a plasticizer is added to a curable composition containing an oxyalkylene polymer having a reactive silicon group. It was found that the dryness was deteriorated when Since it is a simple method to use a plasticizer to reduce the viscosity of the composition and improve the tensile properties of the cured product, the present inventors have searched for a plasticizer that does not deteriorate the drying property of the alkyd paint, It has been found that the above problem is improved by using an oxyalkylene polymer as a plasticizer (JP-A 1-279958).

The present inventors have further searched for a plasticizer which improves the drying property of alkyd paints. As a result, when an oxyalkylene polymer having a high molecular weight and a narrow molecular weight distribution is used as the plasticizer, the drying property is improved. I found that.

[0006]

That is, the curable composition of the present invention comprises (A) a silicon containing at least one reactive silicon group (a silicon atom having a hydroxyl group or a hydrolyzable group bonded thereto in one molecule). An oxyalkylene polymer containing an atom-containing group capable of forming a siloxane bond, and (B) a number average molecular weight of 3,000 or more, and Mw / Mn (weight average molecular weight / number average) Molecular weight)
Of 1.5 or less is included in the oxyalkylene polymer.

In the present invention, an oxyalkylene polymer having at least one reactive silicon group in one molecule (hereinafter, also referred to as oxyalkylene polymer (A)).
Is used.

The oxyalkylene polymer (A) is
JP-B-45-36319, JP-A-46-12154, JP-A-49-32673, JP-A-50-156599, JP-A-51-73561, JP-A-54-6096, and JP-A-55-8.
No. 2123, No. 55-123620, No. 55-125.
No. 121, No. 55-131022, No. 55-1351
No. 35, No. 55-137129, and the like.

The molecular chain of the oxyalkylene polymer (A) is essentially of the general formula

[Chemical 1] (In the formula, R ¹ is a divalent hydrocarbon group, but most preferably most is an alkylene group having 3 or 4 carbon atoms.) It is preferable to have a repeating unit represented by the following. As a specific example of R ¹ ,

[Chemical 2] And so on. The oxyalkylene molecular chain of the alkylene polymer (A) may consist repeating units of only one kind may be made of two or more kinds of repeating units. The preferred R ^1, in particular

[Chemical 3] Is preferred.

The main chain of the oxyalkylene polymer (A) has the general formula

[Chemical 4] Although it may consist of only the repeating unit represented by, it may contain other repeating units. When containing other repeating units, the general formula

[Chemical 5] The repeating unit represented by 60% (% by weight,
The same shall apply hereinafter), more preferably 80% or more.

The reactive silicon group which can be crosslinked and / or polymerized by forming a siloxane bond in the oxyalkylene polymer (A) is a well-known functional group and is characterized in that it can be crosslinked even at room temperature. Have The reactive silicon group is not particularly limited, but representative examples thereof include a group represented by the following general formula [Chemical formula 6].

[0012]

[Chemical 6] [In the formula, R ² represents a substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms or a triorganosiloxy group,
The (2-a) + 3-b) R ^{2 s} may be different.
X is a hydroxyl group or a hydrolyzable group, and (ma + b) X's may be different. a is 0, 1 or 2, b
Represents 0, 1, 2 or 3, respectively, and (ma +
b) ≧ 1 and m is an integer from 0 to 19. m

[Chemical 7] A in may be different. Among the reactive silicon groups represented by the above general formula [Chemical formula 6], the group represented by the following general formula [Chemical formula 8] is preferable from the viewpoint of economy.

[0013]

[Chemical 8] (In the formula, R ² is the same as above, and n is 1, 2 or 3.) Specific examples of the hydrolyzable group which is one kind of X in the above general formula [Chemical Formula 6] include, for example, a halogen atom, Examples thereof include a hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amido group, an aminooxy group, a mercapto group and an alkenyloxy group. Of these, alkoxy groups such as methoxy group and ethoxy group are preferable from the viewpoint of mild hydrolyzability.

Specific examples of R ² in the general formula [Chemical Formula 6] include alkyl groups such as methyl group and ethyl group, cycloalkyl groups such as cyclohexyl group, aryl groups such as phenyl group and benzyl group. An aralkyl group or (R ′) ₃ SiO— (wherein R ′ is a methyl group,
(A substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms such as a phenyl group, and three R's may be different)
And a triorganosiloxy group.
Of these, a methyl group is particularly preferable.

The number of reactive silicon groups in the oxyalkylene polymer (A) may be 1 or more per molecule, but from the viewpoint of obtaining sufficient curability, the average is 1.
It is preferably 1 or more, more preferably 1.5 to 4. Further, the reactive silicon group is preferably present at the terminal of the molecular chain of the oxyalkylene polymer (A).

The number average molecular weight of the oxyalkylene polymer (A) is preferably 3,000 to 30,000,
Those of 6,000 to 15,000 are more preferable. The oxyalkylene polymer (A) may be used alone or in combination of two or more kinds.

The oxyalkylene polymer (A) includes, for example, a hydrosilane compound in which a hydrogen atom is bonded to the group represented by the above general formula [Chemical Formula 6], and a general formula

[Chemical 9] (In the formula, R ³ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, R ⁴ is a divalent organic group having 1 to 20 carbon atoms, and c is 0.
Or 1. ) An oxyalkylene polymer having an olefin group represented by
It is produced by a method such as an addition reaction using a Group I transition metal compound as a catalyst.

Examples of methods other than the above for producing the oxyalkylene polymer (A) include the following methods (1) to (5), but the present invention is not limited to these methods. .

The hydroxyl group-terminated oxyalkylene polymer is reacted with a polyisocyanate compound such as toluene diisocyanate to give an isocyanate group-terminated oxyalkylene polymer, and then the isocyanate group is added with a general formula

[Chemical 10] (W is a hydroxyl group, a carboxyl group, a mercapto group,
Alternatively, it is an active hydrogen-containing group such as a primary or secondary amino group, and n, R ² , R ⁴ and X are the same as defined above. ) A method of reacting a W group of a silicon compound represented by

In the olefin group of the oxyalkylene polymer having the olefin group represented by the general formula [Chem. 9],
A method of subjecting a mercapto group of a silicon compound represented by the general formula [Chemical Formula 10] in which W is a mercapto group to an addition reaction.

The hydroxyl group of the hydroxy-terminated oxyalkylene polymer has the general formula

[Chemical 11] (Wherein R ² , R ⁴ , X and n are the same as defined above).

In the method of reacting a hydrosilyl compound having a hydrogen atom bonded to the group represented by the general formula [Chemical formula 6] with an oxyalkylene polymer having an olefin group represented by the general formula [Chemical formula 9], After reacting with, a part or all of the X groups may be converted into other hydrolyzable groups or hydroxyl groups. For example, when the X group is a halogen atom or a hydrogen atom, it is preferable to convert these groups into an alkoxy group, an acyloxy group, an aminooxy group, an alkenyloxy group, a hydroxyl group or the like before use.

In the general formula [Chem. 9], R ³ is a hydrogen atom or a substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms, preferably a hydrogen atom or a hydrocarbon group, It is preferably a hydrogen atom.

Further, although R ⁴ is a divalent organic group having 1 to 20 carbon atoms,

[Chemical 12] (In the formula, R ⁵ is a divalent hydrocarbon group having 1 to 10 carbon atoms.)
And the like, and particularly preferably a methylene group.

A specific method for producing an oxyalkylene polymer having an olefin group represented by the general formula [Chem. 9] is, for example, as disclosed in JP-A No. 54-6097, an oxyalkylene polymer. A method in which a terminal hydroxyl group of a polymer is reacted with a compound having an unsaturated group and bonded by an ether bond, an ester bond, a urethane bond, a carbonate bond, or the like, or an epoxy compound such as ethylene oxide or propylene oxide is polymerized. At that time, a method of introducing an olefin group-containing epoxy compound such as allyl glycidyl ether and copolymerizing it to introduce an olefin group into a side chain can be exemplified.

The composition of the present invention together with the oxyalkylene polymer (A) has an oxyalkylene polymer having a number average molecular weight of 3,000 or more and Mw / Mn of 1.5 or less (hereinafter, high molecular weight). An oxyalkylene polymer (B) is also used.

The high molecular weight oxyalkylene polymer (B) used in the present invention has a number average molecular weight of 3,000 or more, preferably 6,000 or more. When the number average molecular weight is less than 3,000, the drying property (curability) of the coating film when the alkyd-based coating material is applied to the cured product tends to deteriorate.

The cured product to which the alkyd-based paint is applied in the present specification is not limited to the one in which the composition completely cures and exhibits the predetermined characteristics, and it may be cured even after the construction. It is a concept that includes those that can be painted.

The main chain of the high molecular weight oxyalkylene polymer (B) is essentially the same as in the case of the oxyalkylene polymer (A), that is, 60% or more of the monomer units constituting the main chain. , Preferably 80% or more is the general formula

[Chemical 13] (In the formula, R ¹ is the same as above.), Which has good compatibility with the oxyalkylene polymer (A) and is excellent in the effect of lowering the viscosity. It is also preferable from the viewpoint of lowering the elastic modulus and increasing the elongation of the cured product. Furthermore, the fact that the number of molecular terminals is small or the number of hydroxyl groups at the molecular terminals is small can lower the viscosity of the composition and improves the drying property of the alkyd-based coating material coated on the cured product. From the above, those having substantially no hydroxyl group at the molecular end are more preferable. For the same reason, it is more preferable that the terminal has an alkyl ether group, an allyl ether group, an aryl ether group, or the like.

Further, if the proportion of the components having a number average molecular weight of 1,000 or less is 10% (the proportion from the value measured by the GPC (gel permeation chromatography) method, the same applies hereinafter) or less, the drying property of the alkyd paint is It is preferable that it is 5% or less because it is improved.

The high molecular weight oxyalkylene polymer (B) has a narrow molecular weight distribution, that is, Mw / M.
It is preferable that n (weight average molecular weight / number average molecular weight) is small, because the viscosity of the composition can be reduced and the drying property of the alkyd-based coating material coated on the cured product is improved. The high molecular weight oxyalkylene polymer (B) used in the present invention has Mw / Mn of 1.5 or less, preferably 1.3 or less. The molecular weight and the molecular weight distribution are measured by the GPC method.

The viscosity of the high molecular weight oxyalkylene polymer (B) at room temperature (23 ° C.) is preferably 80 poise or less in order to enhance the plasticizing effect of the composition. It is more preferably 50 poise or less. That is,
The effect as a plasticizer is preferably one having a low molecular weight, and preferably one having a high molecular weight in view of the drying property of the alkyd-based paint. However, the component (B) of the present invention has a higher molecular weight than that having a wide molecular weight distribution. Despite its high price, it has a great effect as a plasticizer.

Specific examples of such a high molecular weight oxyalkylene polymer (B) include polyoxypropylene glycol having a number average molecular weight of 3,000 or more and Mw / Mn of 1.5 or less. Polyoxypropylene glycol having one end, preferably both ends, whose hydroxyl groups are blocked by alkyl ether bond, alkylphenyl ether bond, alkenyl ether bond, allyl ether bond, urethane bond, ester bond, urea bond, amide bond , Those having a hydroxyl group blocked by a group such as an alkyl group, an aryl group, or an alkenyl group by a bond such as a carbonate bond.
It is not limited to these.

High molecular weight and narrow molecular weight distribution (Mw / Mn
It is difficult to obtain an oxyalkylene-based polymer by a usual polymerization method of oxyalkylene (anionic polymerization method using caustic alkali) or a chain extension reaction method using this polymer as a raw material. 61-197631
No. 61-215622 and 61-215.
623, JP-A-61-218632, JP-B-46-
It can be obtained by the methods described in No. 27250 and Japanese Patent Publication No. 59-15336.

The high molecular weight oxyalkylene polymer (B) may be used alone or in combination of two or more kinds. The high molecular weight oxyalkylene polymer (B) may be blended as a solvent during the production of the oxyalkylene polymer (A).

The amount of the above-mentioned high molecular weight oxyalkylene polymer (B) used is such that the oxyalkylene polymer (A) 1
10 to 500 parts are preferable, and 20 to 200 parts are more preferable, relative to 00 parts (parts by weight, the same applies hereinafter). The amount is 1
If it is less than 0 part, the plasticizing effect is small and it becomes impractical in terms of lowering the elastic modulus and increasing elongation of the cured product, and if it exceeds 500 parts, curing tends to be very slow.

If necessary, a curing accelerator, a filler, and other additives may be added to the composition of the present invention.

The curing accelerator usable in the present invention includes:
Examples include organic tin compounds, acidic phosphoric acid esters, reaction products of acidic phosphoric acid esters and amines, saturated or unsaturated polyvalent carboxylic acids or acid anhydrides thereof, organic titanate compounds, organic aluminum compounds, organic zirconium compounds. To be

Specific examples of the organic tin compound include dibutyltin dilaurate, dioctyltin dimaleate, dibutyltin phthalate, tin octylate and dibutyltin methoxide.

The above-mentioned acidic phosphate ester is

[Chemical 14] A phosphoric acid ester containing a moiety, for example,

[Chemical 15] (In the formula, d is 1 or 2, and R is an organic residue.)

[Chemical 16]

[Chemical 17]

[Chemical 18] And so on.

Further, examples of the organic titanate compound include titanic acid esters such as tetrabutyl titanate, tetraisopropyl titanate and triethanolamine titanate.

Examples of the filler include heavy calcium carbonate, light calcium carbonate, colloidal calcium carbonate,
Examples thereof include kaolin, talc, silica, titanium oxide, aluminum silicate, magnesium oxide, zinc oxide and carbon black.

Examples of the other additives include hydrogenated castor oil, an anti-sagging agent such as organic bentonite, a coloring agent, and an antiaging agent.

Further, it goes without saying that a low molecular weight plasticizer such as dioctyl phthalate may be used as a plasticizer in the composition of the present invention as long as the effect of the present invention is achieved.

The composition of the present invention as described above comprises an adhesive,
It can be usefully used as an adhesive, a paint, a waterproof film, a sealant composition, a molding material, a cast rubber material, a foam material and the like.

For example, when applied as a building sealant, 10 to 300 parts of an inorganic filler such as calcium carbonate, talc or kaolin is usually added to 100 parts of the oxyalkylene polymer (A), and if necessary. Titanium oxide, pigments such as carbon black, UV absorbers, anti-aging agents such as radical chain inhibitors, air-drying compounds such as drying oil, synthetic drying oil, etc.
By applying a kneader or paint roll that has been kneaded sufficiently uniformly and exposing it to moisture in the air, it quickly cures, for example, in about 1 hour to several days, and has good weather resistance, transparency, and tensile elongation. The rubber elastic body shown is obtained.

When it is applied as a paint, it cures in the same manner as described above, and a cured product having a tensile elongation and weather resistance much higher than generally thought is obtained, and a highly elastic paint for construction, a primer for concrete structure, It has excellent properties as a waterproofing agent.

When applied as a waterproof film for coating film, it has an excellent balance of breaking strength and elongation, and has good durability and water resistance, so that deterioration such as blistering and peeling is improved as compared with the existing technology. It

Further, when it is applied as an adhesive, it is expected to be applied to a structural adhesive as an adhesive having excellent adhesive strength, and in particular a well-balanced peel adhesive strength and shear adhesive strength.

When an alkyd coating is applied onto a cured product obtained from the composition of the present invention, the composition is almost completely cured before coating. Therefore, it is preferable because it can be easily coated, and the coating film does not hinder the supply of water necessary for curing. However, when the composition is in a tack-free state and the surface layer is solidified, the composition can be applied.

The alkyd paint is not particularly limited, and polybasic acids (phthalic anhydride, maleic anhydride, etc.) and polyhydric alcohols (glycerin, pentaerythritol,
So-called oil-modified alkyd resins obtained by modifying condensates with ethylene glycol, trimethylolethane, etc.) with fatty oils or fatty acids (linseed oil, soybean oil, castor oil, safflower oil, etc.) and alkyd resins of various resins or vinyl A paint that uses a modified alkyd resin modified with a monomer as the main element for forming a coating film.Alkyd resin varnish, alkyd resin enamel, and construction used for vehicle, aircraft, and industrial coating. , Alkyd resin compound paints (also called synthetic resin compound paints) used for painting railway bridges, ships, etc., alkyd resin compound paints used as substrate paints for automobiles, machinery, electrical products, furniture, etc. It may be in the form. The effect is remarkable especially in long-oil alkyd paints, which are widely used and have a large amount of drying oil.

The alkyd-based paint dries faster than the oil-based paint, and the coating film is hard and glossy, and has good adhesion and
It is excellent in most aspects such as weather resistance, oil resistance, and resistance, and its physical properties can be adjusted in a wide range depending on the type of modified oil, oil length, type of modification, etc. is there.

The composition of the present invention is excellent in coatability of the alkyd-based paint on the surface of the cured product, but is also excellent in workability because the composition itself has a low viscosity.

[0054]

EXAMPLES Next, the composition of the present invention will be specifically described based on Examples.

Synthesis Example 1 800 g of an oxypropylene-based polymer having an allyl ether group introduced at 97% of all terminals and an average molecular weight of about 8,000 was placed in a pressure resistant reactor equipped with a stirrer, and 19 g of methyldimethoxysilane was added. Then, a chloroplatinic acid catalyst solution (H ₂ Pt
Cl ₆ · 6H ₂ O solution was dissolved in isopropyl alcohol 18ml and tetrahydrofuran 160ml of 8.9g of) After addition of 0.34 ml, allowed to react for 6 hours at 80 ° C..

The amount of residual hydrosilyl groups in the reaction solution is calculated as I
As a result of quantification by R spectrum analysis, almost no residue remained. Moreover, when the reactive silicon group was quantified by the NMR method, it was confirmed that (CH ₃ O) ₂ Si
_{(CH 3) CH 2 CH 2} CH 2 O- group oxypropylene polymer having about 1.7 per molecule was obtained.

Example 1 and Comparative Examples 1-2 As shown in Table 1, the oxypropylene polymer (A) obtained in Synthesis Example 1 and the high molecular weight oxyalkylene polymer (B) shown in Table 1 Mix ingredients such as, mix well,
A composition was made. The viscosity of the obtained composition is shown in Table 1.

Further, using the composition, a sheet having a thickness of 3 mm was prepared and cured at room temperature for one day, and then alkyd paint (trade name: Rock Coat, manufactured by Rock Paint Co., Ltd.) was applied. The curability of the alkyd paint when left for the number of days shown in Table 1 was examined. The results are shown in Table 1.

In Table 1, the column of the high molecular weight oxyalkylene polymer (B) indicates that the number average molecular weight is 9,0.
An oxypropylene polymer having an Mw / Mn of 1.25 and an allyl ether group at both ends is an oxypropylene polymer having a number average molecular weight of 7,500 and an Mw / Mn of 1.8 and an allyl ether group at both ends. The polymer is an oxypropylene polymer having a number average molecular weight of 5,200 and Mw / Mn of 1.6 and allyl ether groups at both ends. Measurement of molecular weight and molecular weight distribution is made by Tosoh high-speed GPC device HL
C-8020 is used, and TSK gel G30 is used as a column.
00H and G4000H connected in series, THF as a solvent, a measurement temperature of 40.0 ° C., a solvent flow rate of 1.0 ml / min, and a sample solution of 0.05 g of a sample dissolved in 10 cc of THF were used. I did it.

Regarding the symbols in the curability column of alkyd paint, ◯ means that the applied paint is completely cured, and Δ means that the applied paint is cured but the surface remains sticky.

[0061]

[Table 1] From the results in Table 1, it is understood that the drying property of the alkyd-based coating material applied on the cured product obtained from the composition of the present invention is good.

[0062]

EFFECTS OF THE INVENTION The curable composition of the present invention has a low viscosity and thus has good workability. Further, the cured product obtained from the curable composition of the present invention can be coated with an alkyd-based paint under normal conditions and dried, and a good alkyd-based paint coating film can be formed, It also has an excellent plasticizing effect.

Claims (1)

[Claims] 1. An oxyalkylene polymer containing (A) at least one reactive silicon group in one molecule, and (B) having a number average molecular weight of 3,000 or more and Mw.
A curable composition containing an oxyalkylene polymer having a Mn of 1.5 or less.