JPH0565400A - Curable composition - Google Patents

Abstract

(57) [Summary] [Structure] (A) Oxyalkylene containing at least one reactive silicon group in one molecule, having a number average molecular weight of 6,000 or more and Mw / Mn of 1.6 or less. 100 parts by weight of polymer, and (B) photocurable substance 0.01 to 20
It consists of parts by weight. [Effect] The room temperature curable composition of the present invention exhibits a remarkable antifouling effect when exposed for a long period of time.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a room temperature curable composition, and more particularly to a room temperature curable composition containing an oxyalkylene polymer containing at least one reactive silicon group in one molecule as a main component. .

[0002]

Oxygen having at least one 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) in one molecule. A room temperature curable composition based on an alkylene polymer can be used, for example, as a sealant for buildings, and is inexpensive and has excellent performance. However, this composition, depending on the composition and curing conditions,
The surface of the cured product is contaminated by the adhesion of dust or the like to impair the appearance, which is not preferable (hereinafter, abbreviated as "contamination").
Becomes

Therefore, various compositions have been proposed so far in order to improve this drawback. For example, JP-A-55-36
No. 241, by adding a photocurable resin to a silicon-modified polyoxyalkylene, and JP-A 1-149.
No. 851 is intended to prevent contamination of the surface of a cured product by adding a liquid diene polymer to silicon-modified polyoxyalkylene.

[0004]

However, although these compositions have been found to have a certain antifouling effect, they have the drawback of not being sufficiently effective when exposed for a long period of time. .

Therefore, an object of the present invention is to provide a room temperature curable composition which can solve the above-mentioned drawbacks and improves the surface of the cured product to be non-tacky, thereby exhibiting a remarkable anti-staining effect. It is in.

[0006]

The room temperature curable composition of the present invention contains (A) at least one reactive silicon group in one molecule, and has a number average molecular weight (Mn) of 6,000 or more. Further, it is composed of 100 parts by weight of an oxyalkylene polymer having Mw / Mn (weight average molecular weight / number average molecular weight) of 1.6 or less, and 0.01 to 20 parts by weight of the (B) photocurable substance.

The reactive silicon group referred to in the present invention is not particularly limited, but a typical example thereof is a group represented by the following general formula [Chemical formula 1].

[0008]

[Chemical 1]

[Wherein R ¹ and R ² are each an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or (R ′) ₃ S
a triorganosiloxy group represented by iO-, R ¹
Alternatively, when two or more R ² are present, they may be the same or different. Here, R'is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and three R's may be the same or different. X represents a hydroxyl group or a hydrolyzable group, and when two or more X are present, they may be the same or different. a represents 0, 1, 2 or 3 and b represents 0, 1 or 2. Also, m

[0010]

[Chemical 2]

B in the above may be different. m is 0
An integer of -19 is shown. However, it is assumed that a + Σb ≧ 1 is satisfied. The hydrolyzable group represented by X is not particularly limited as long as it is a conventionally known hydrolyzable group. Specific examples include 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, an aminooxy group, a mercapto group and an alkenyloxy group. Of these, a hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an aminooxy group, a mercapto group and an alkenyloxy group are preferable, but a methoxy group is preferable from the viewpoint of easy hydrolysis and easy handling. Particularly preferred are alkoxy groups such as

One to three hydrolyzable groups or hydroxyl groups can be bonded to one silicon atom, and (a + Σb) is 1
It is preferably -5. When two or more hydrolyzable groups or hydroxyl groups are present in the reactive silicon group, they may be the same or different.

There may be one silicon atom or two or more silicon atoms in the reactive silicon group, but in the case of a reactive silicon group in which silicon atoms are linked by a siloxane bond or the like, 20 silicon atoms are included. There may be a degree.

The reactive silicon group represented by the following general formula [Chemical Formula 3] is preferable from the viewpoint of easy availability.

[0015]

[Chemical 3]

(In the formula, R ² , X and a are the same as above.) Specific examples of R ¹ and R ² in the above-mentioned general formula [Chemical Formula 1] include, for example, alkyl such as methyl group and ethyl group. Groups, cycloalkyl groups such as cyclohexyl groups, aryl groups such as phenyl groups, aralkyl groups such as benzyl groups, R'is methyl groups, phenyl groups, etc. (R ')
_{3 A} triorganosiloxy group represented by SiO— and the like can be mentioned. A methyl group is particularly preferable as R ¹ , R ² and R ′.

At least one reactive silicon group, preferably 1.1 to 5 is present in one molecule of the oxyalkylene polymer. When the number of reactive silicon groups contained in one molecule of the polymer is less than 1, the curability becomes insufficient,
It becomes difficult to exhibit good rubber elasticity behavior.

The reactive silicon group may be present at the terminal of the oxyalkylene polymer molecular chain or may be present inside. When the reactive silicon group is present at the terminal of the molecular chain, the amount of effective network chains of the oxyalkylene polymer component contained in the finally formed cured product increases, so that high strength, high elongation, and low elastic modulus are achieved. The rubber-like cured product shown is easily obtained.

The oxyalkylene polymer constituting the polymerization main chain in the component (A) of the present invention has a general formula

[0020]

[Chemical 4]

(Wherein R is a divalent alkylene group having 1 to 4 carbon atoms) can be used, but from the viewpoint of easy availability,

[0022]

[Chemical 5]

An oxypropylene polymer containing a repeating unit represented by: is preferred. The oxypropylene polymer may be linear or branched, or may be a mixture thereof. Further, other monomer units and the like may be contained, but the monomer unit represented by [Chemical Formula 5] is present in the polymer in an amount of 50% by weight or more, preferably 80% by weight or more. preferable.

The reactive silicon group-containing oxyalkylene polymer which is the component (A) of the present invention is preferably obtained by introducing a reactive silicon group into an oxyalkylene polymer having a functional group.

High molecular weight and narrow molecular weight distribution (Mw / Mn by GPC (gel permeation chromatography) is small)
It is extremely difficult to obtain an oxyalkylene polymer having a functional group 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, Polymerization methods, JP-A-61-197631 and JP-A-61-2156.
No. 22, JP-A-61-215623, JP-A-61-2
18632, Japanese Patent Publication No. 46-27250 and Japanese Patent Publication No. 5
It can be obtained by the method described in 9-15336 or the like. Since the molecular weight distribution of the reactive silicon group-containing oxyalkylene polymer depends on the molecular weight distribution of the corresponding polymer before the introduction of the reactive silicon group, the molecular weight distribution of the polymer before the introduction is preferably as narrow as possible.

The reactive silicon group may be introduced by a known method. That is, for example, the following methods can be mentioned.

(1) An oxyalkylene polymer having a functional group such as a hydroxyl group at the terminal is reacted with an organic compound having an active group and an unsaturated group reactive with this functional group, or an unsaturated group An unsaturated group-containing oxyalkylene polymer is obtained by copolymerization with the contained epoxy compound.
Then, the obtained reaction product is hydrosilylated by reacting hydrosilane having a reactive silicon group.

(2) The unsaturated group-containing oxyalkylene polymer obtained in the same manner as in the method (1) is reacted with a compound having a mercapto group and a reactive silicon group.

(3) An oxyalkylene polymer having a functional group such as a hydroxyl group, an epoxy group or an isocyanate group (hereinafter referred to as a Y functional group) at the terminal, has a functional group reactive with the Y functional group (hereinafter , Y ′ functional group) and a reactive silicon group.

Examples of the silicon compound having the Y'functional group are γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane and γ-aminopropyltriethoxysilane. Amino group-containing silanes such as; γ-
Mercapto group-containing silanes such as mercaptopropyltrimethoxysilane and γ-mercaptopropylmethyldimethoxysilane; such as γ-glycidoxypropyltrimethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane Epoxy silanes; vinyl-type unsaturated group-containing silanes such as vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-acryloyloxypropylmethyldimethoxysilane; γ-chloropropyltrimethoxysilane, etc. Chlorine atom-containing silanes;
γ-isocyanatopropyltriethoxysilane, γ-
Isocyanate-containing silanes such as isocyanatopropylmethyldimethoxysilane and the like; hydrosilanes and the like such as methyldimethoxysilane, trimethoxysilane, methyldiethoxysilane and the like can be specifically exemplified, but are not limited thereto. Absent.

Among the above methods, the method (1) or the method (3) of reacting a polymer having a hydroxyl group at the terminal with a compound having an isocyanate group and a reactive silicon group is preferable.

The polymer which is the component (A) of the present invention has a number average molecular weight (Mn) of 6,000 or more and Mw / Mn.
Since the (ratio of the weight average molecular weight to the number average molecular weight) is 1.6 or less, the effect of making the surface of the composition of the present invention faster and making the surface non-tacky when cured is remarkable. When the number average molecular weight is less than 6,000 or Mw / Mn exceeds 1.6, the effect of non-adhesiveness decreases. The preferred number average molecular weight is 10,000 or more. From the effect of non-adhesiveness, the smaller Mw / Mn is preferable, and the Mw / Mn is preferably 1.5 or less.

The photocurable substance of the component (B) used in the present invention is a substance which undergoes a chemical change in the molecular structure in a fairly short time by the action of light to cause a change in physical properties such as curing. Many compounds such as organic monomers, oligomers, resins or compositions containing them are known as compounds of this type, and any commercially available compounds can be adopted. As a typical example, an unsaturated acrylic compound, polyvinyl cinnamate, or an azide resin can be used.

The unsaturated acrylic compound is a monomer, an oligomer or a mixture thereof having 1 to several acrylic or methacrylic unsaturated groups, and is propylene (or butylene, ethylene) glycol di (meth) acrylate, Neopentyl glycol di (meta)
Examples thereof include monomers such as dimethacrylate and oligoesters having a molecular weight of 10,000 or less.

Examples of polyvinyl cinnamate include a photosensitive resin having a cinnamoyl group as a photosensitive group, which is obtained by esterifying polyvinyl alcohol with cinnamic acid, and many polyvinyl cinnamate derivatives.

The azide resin is known as a photosensitive resin having an azide group as a photosensitive group, and is usually a rubber photosensitive liquid to which a diazide compound is added as a photosensitive agent, as well as a "photosensitive resin" (3, 1972). Published on 17th of March, published by The Printing Institute of Japan, page 93-, page 106-, page 117-). These are used alone or in combination, and a sensitizer is added if necessary. Can be used.

The amount of these used is 0.01 to 20 parts by weight based on 100 parts by weight of the reactive silicon group-containing oxyalkylene polymer as the component (A). If it is less than 0.01 parts by weight, the effect is small, and if it exceeds 20 parts by weight, the physical properties may be adversely affected. The effect may be enhanced by adding a sensitizer such as a ketone or a nitro compound or an accelerator such as an amine.

A curing catalyst, a plasticizer, a filler, and other additives may be added to the composition of the present invention, if necessary.

Specific examples of the curing catalyst include metal carboxylic acid salts such as tin octylate, dibutyltin dilaurate, dibutyltin maleate and dibutyltin phthalate; reaction products of organic tin oxide and ester; tetrabutyl titanate, organo. Organic titanic acid esters such as siloxytitanium; amines, amine salts, quaternary ammonium salts, granidine compounds and the like. These can be used alone or in combination. These curing catalysts are 0 to 100 parts by weight of the reactive silicon group-containing oxyalkylene polymer.
Use about 10 parts by weight.

Specific examples of the plasticizer include phthalic acid esters such as dibutyl phthalate, diheptyl phthalate, di (2-ethylhexyl) phthalate, butylbenzyl phthalate and butylphthalyl butyl glycolate; dioctyl adipate, dioctyl sebacate. And non-aromatic dibasic acid esters such as; tricresyl phosphate, tributyl phosphate, and other phosphoric acid esters, and the like. Examples of relatively high molecular weight plasticizers include dibasic acids and dihydric alcohols. Polyester plasticizers such as polyesters; Polyethers such as polypropylene glycol and its derivatives; Poly-α-
Examples thereof include polystyrenes such as methylstyrene and polystyrene. These can be used alone or in combination. These plasticizers are used in an amount of about 20 to 100 parts by weight based on 100 parts by weight of the reactive silicon group-containing oxyalkylene polymer.

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. When a filler is used, its amount is preferably in the range of 10 to 300 parts by weight with respect to 100 parts by weight of the reactive silicon group-containing oxyalkylene polymer.

Examples of the other additives include hydrogenated castor oil, anti-sagging agents such as organic bentonite, colorants, anti-aging agents, and adhesion-imparting agents.

The composition of the present invention thus obtained is useful as an adhesive, a pressure-sensitive adhesive, a paint, a waterproof film, a sealant composition, a molding material, a cast rubber material, a foam material and the like. Can be used. Above all, application to a sealant is particularly useful.

[0044]

EXAMPLES The composition of the present invention will be described in detail below with reference to examples.

Synthesis Example 1 A reactor having a pressure resistance of 1.5 liter and having a molecular weight of 9.00
0 polyoxypropylene glycol (Mw / Mn =
400 g (0.089 equivalent) of 1.24 and a viscosity of 41 poise) was charged and placed under a nitrogen atmosphere.

At 137 ° C, 21.1 g (0.109) of a 28% solution of sodium methoxide in methanol was added from a dropping funnel.
(Equivalent weight) was added dropwise and the mixture was reacted for 7 hours, and then degassed under reduced pressure.
Return to nitrogen atmosphere 12.9 g (0.16 g) of allyl chloride
(9 equivalents) was added dropwise and reacted for 2 hours for allylation.

After the reaction product was dissolved in hexane and subjected to adsorption treatment with aluminum silicate, hexane was removed under reduced pressure to obtain 310 g of a yellow transparent polymer (viscosity 33 poise).

250 g (0.056 equivalents) of this polymer
Was charged into a pressure-resistant glass reaction container and placed under a nitrogen atmosphere. Catalyst solution of chloroplatinic acid _{(H 2 PtCl 6 · 6H 2} O
0.05 ml of a solution prepared by dissolving 25 g in 500 g of isopropyl alcohol) was added, and the mixture was stirred for 30 minutes. After adding 8.25 g (0.078 equivalent) of dimethoxymethylsilane from a dropping funnel and reacting at 90 ° C. for 3 hours, degassing gave 240 g of a yellow transparent polymer.

Synthesis Example 2 In a 1.5 liter pressure-resistant glass reaction vessel, the molecular weight was 15,0.
00 polyoxypropylene triol (Mw / Mn =
Then, 401 g (0.081 equivalent) of 1.38 and viscosity 89 poise) was charged and placed under a nitrogen atmosphere.

At 137 ° C., 19.1 g (0.099) of a 28% solution of sodium methoxide in methanol was added from a dropping funnel.
(Equivalent weight) was added dropwise, the mixture was reacted for 5 hours, and then degassed under reduced pressure.
Return to nitrogen atmosphere 9.0 g allyl chloride (0.118
(Equivalent amount) was added dropwise, and the mixture was reacted for 1.5 hours, and then 5.6 g (0.2%) of a 28% methanol solution of sodium methoxide.
029 equivalents) and allyl chloride 2.7 g (0.035 equivalents)
Was used for allylation.

After the reaction product was dissolved in hexane and subjected to adsorption treatment with aluminum silicate, the hexane was removed under reduced pressure to obtain 311 g of a yellow transparent polymer (viscosity 68 poise).

270 g (0.065 equivalents) of this polymer
Was charged into a pressure-resistant glass reaction container and placed under a nitrogen atmosphere. Catalyst solution of chloroplatinic acid _{(H 2 PtCl 6 · 6H 2} O
0.075 ml of a solution obtained by dissolving 25 g in 500 g of isopropyl alcohol) was added, and the mixture was stirred for 30 minutes. Dimethoxymethylsilane (6.24 g, 0.059 equivalent) was added through the dropping funnel, reacted at 90 ° C. for 4 hours and then degassed to obtain 260 g of a yellow transparent polymer.

Comparative Synthesis Example 1 420 g of polyoxypropylene glycol having a number average molecular weight of 3,000 and 80 g of polyoxypropylene triol having a number average molecular weight of 3,000 were charged into a nitrogen-substituted pressure-resistant glass reaction vessel. Sodium hydroxide 40
g was added and the mixture was reacted at 60 ° C. for 13 hours, and then 19 g of bromochloromethane was reacted at 60 ° C. for 10 hours. (Mw / Mn of the obtained polymer was 2.1, and viscosity was 38.
It was 5 poise. ) Subsequently, 15 g of allyl chloride was added and reacted for 36 hours. After the reaction was completed, the pressure was reduced to remove volatile substances.

The contents were taken out in a beaker and dissolved in hexane. After adsorption treatment with aluminum silicate, hexane was removed under reduced pressure.

500 g of this polymer was charged into a reaction vessel purged with nitrogen, and a catalyst solution of chloroplatinic acid (H ₂ PtCl) was added.
The ₆ · _6H 2 O 25g Isopropyl alcohol 500
0.03 g of a solution dissolved in g) was added, and then 12 g of dimethoxymethylsilane was added and reacted at 80 ° C. for 4 hours. After the reaction was completed, the pressure was reduced to remove volatile substances, and 500 g of a pale yellow transparent polymer was obtained.

The viscosities of the polymers obtained in Synthesis Examples 1 and 2 and Comparative Synthesis Example 1 were measured using a B-type viscometer (BM-type rotor N
o. 4, 12 rpm) and was measured at 23 ° C. In addition, the number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) of each polymer are determined by GPC (gel permeation chromatography).
Was analyzed by. GPC was analyzed at an oven temperature of 40 ° C. using tetrahydrofuran as a distillation solvent in a column filled with polystyrene gel (manufactured by Tosoh Corporation). The results are shown in [Table 1].

[0057]

[Table 1]

Examples 1 to 4 and Comparative Examples 1 to 4 100 g of the polymer obtained in Synthesis Example 1, the polymer obtained in Synthesis Example 2 or the polymer obtained in Comparative Synthesis Example 1 On the other hand, after adding a photocurable substance in an amount (g) shown in [Table 2], colloidal calcium carbonate (manufactured by Maruo Calcium Co., Ltd., trade name Viscolite R)
120 g, heavy calcium carbonate (manufactured by Shiraishi Industry Co., Ltd., trade name Whiten SB) 20 g, dioctyl phthalate 5
0 g, hindered phenol anti-aging agent (Ciba Geigy, trade name Irganox 1010) 1 g, benzotriazole ultraviolet absorber (Ciba Geigy, trade name Tinupine 327) 1 g, tin octylate (II) 3
g and 1 g of laurylamine were added and sufficiently kneaded and then passed through a small three-piece paint roll three times to prepare a sheet having a thickness of about 5 mm.

After curing this at 23 ° C. and 60% RH, it was exposed outdoors in Kobe City, Hyogo Prefecture (slope of 45 ° on the south side), and the contamination state of the surface of the test piece was observed. The results are shown in [Table 2].

The photocurable substances in Table 2 are all oligoester acrylates manufactured by Toagosei Co., Ltd. and have the following structures.

[0061]

[Chemical 6]

Further, in the evaluation of the contamination state in [Table 2], ⊚ is not contaminated at all, ∘ is hardly contaminated, Δ is slightly contaminated, x is considerably contaminated, and x is considerably contaminated. X represents a state of being extremely contaminated.

[0063]

[Table 2]

As is clear from [Table 2], the room temperature curable composition of the present invention has excellent stain resistance even after long-term exposure, and obviously does not use a photocurable substance. It is different from the system. Further, the effect of its use is remarkably improved as compared with a system using a reactive silicon group-containing oxyalkylene polymer having a Mw / Mn exceeding 1.6 as a curing component.

In recent years, the market demand for stain resistance has been extremely demanding from the viewpoint of giving importance to aesthetics as well. However, the room temperature curable composition of the present invention is particularly useful for sealing construction, automobiles, ships and roads. It is useful as a material and sealant.

[0066]

INDUSTRIAL APPLICABILITY The room temperature curable composition of the present invention exhibits a remarkable antifouling effect when exposed for a long period of time.

Claims (3)

[Claims] 1. (A) 100 weight of an oxyalkylene polymer containing at least one reactive silicon group in one molecule, having a number average molecular weight of 6,000 or more and Mw / Mn of 1.6 or less. Part and (B) 0.01 to 20 parts by weight of a photocurable substance, a room temperature curable composition. 2. The room temperature curable composition according to claim 1, wherein the oxyalkylene polymer as the component (A) has a number average molecular weight of 10,000 or more. 3. The photocurable substance as the component (B) is at least one selected from the group consisting of unsaturated acrylic compounds, polyvinyl cinnamates and azide resins. The room temperature curable composition according to 1 or 2.