JP3304955B2 - Curable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a novel curable composition containing a reactive silicon group-containing oxypropylene polymer, a plasticizer, and a specific filler.

[0002]

BACKGROUND OF THE INVENTION An oxy group having a reactive silicon group (a silicon atom-containing group containing a silicon atom bonded to a hydroxyl group or a hydrolyzable group and capable of forming a siloxane bond). The propylene polymer can be a liquid polymer, and is cured at room temperature by moisture or the like to produce a rubber-like cured product. For this reason, it is used as an elastic sealant for buildings. The rubber-like cured product desirably has large elongation characteristics and breaking strength as tensile characteristics.

The present inventors have studied a curable composition using an oxypropylene polymer having a reactive silicon group. As a result, the present inventors have found that a composition comprising an oxypropylene polymer having a narrow molecular weight distribution and a specific filler and a plasticizer is used. However, the present inventors have found that a cured product having extremely excellent tensile properties can be obtained, and have reached the present invention.

[0004]

The curable composition of the present invention comprises (A) a polymer having a main chain of

Embedded image In consists repeating unit represented, a oxypropylene polymer having at least one silicon atom-containing group (reactive silicon group) containing bound silicon atom of a hydroxyl group or a hydrolyzable group, Mw / Mn (weight-average (Molecular weight / number average molecular weight) of 1.6 or less and a number average molecular weight (Mn) of 6.0
Oxypropylene polymer having an average particle diameter of 0.0 or more, (B) a phthalate ester plasticizer, and (C) an average particle diameter of 0.0 treated with a fatty acid.
1 to 0.15 μm of calcium carbonate, and 100 parts by weight of the component (A) and the components (B) 1 to 1
50 parts by weight and 1 to 200 parts by weight of the component (C).

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The reactive silicon group contained in the oxypropylene polymer of the component (A) used in the present invention is not particularly limited. And a group represented by the following general formula:

[0006]

Embedded image [Wherein, R ¹ and R ² each represent an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms,
An aralkyl group of 20 or a triorganosiloxy group represented by (R ′) ₃ SiO—, wherein R ¹ or R ² is 2
When there are more than one, they may be the same or different. Here, R 'is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and the three R's may be the same or different. X represents a hydroxyl group or a hydrolyzable group, and when two or more Xs 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

Embedded image B in may be different. m shows the integer of 0-19. However, it is assumed that a + Σb ≧ 1 is satisfied. ].

The hydrolyzable group represented by X is not particularly limited, and may be any conventionally known hydrolyzable group. Specifically, for example, a hydrogen atom, a halogen atom, an alkoxy group, an acyloxy group, a ketoxime group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group,
An alkenyloxy group and the like can be mentioned. 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 preferred, but from the viewpoint of gentle hydrolysis and easy handling, alkoxy groups such as methoxy group are preferred. Groups are particularly preferred.

This hydrolyzable group or hydroxyl group can be bonded to one to three silicon atoms, and (a + Δb) is 1
-5 is preferred. When two or more hydrolyzable groups or hydroxyl groups are present in the reactive silicon group, they may be the same or different.

The reactive silicon group may have one silicon atom or two or more silicon atoms. 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 required. There may be degrees.

[0010] A reactive silicon group represented by the following general formula (5) is preferable from the viewpoint of easy availability.

[0011]

Embedded image (In the formula, R ² , X and a are the same as described above.).

Specific examples of R ¹ and R ² in the above general formula and Chemical Formula 3 include alkyl groups such as methyl group and ethyl group, cycloalkyl groups such as cyclohexyl group, aryl groups such as phenyl group and the like. And an aralkyl group such as a benzyl group, and a triorganosiloxy group represented by (R ′) ₃ SiO— wherein R ′ is a methyl group or a phenyl group. As R ¹ , R ² and R ′, a methyl group is particularly preferred. At least one reactive silicon group per molecule of the oxypropylene polymer, preferably 1.1 to 5
It is good that there exist. When the number of reactive silicon groups contained in one molecule of the polymer is less than one, the curability becomes insufficient and it becomes difficult to exhibit good rubber elasticity behavior.

The reactive silicon group may be present at the terminal of the molecular chain of the oxypropylene polymer or may be present inside. When the reactive silicon group is present at the terminal of the molecular chain, the effective network chain amount of the oxypropylene polymer component contained in the finally formed cured product increases, so that it exhibits high elasticity, high elongation and low elastic modulus. It becomes easier to obtain a rubbery cured product.

The oxypropylene polymer constituting the polymer main chain in the component (A) used in the present invention includes:

Embedded image In it is made of repeating units represented. The oxypropylene polymer may be linear or branched, or a mixture thereof.

As the number average molecular weight (Mn) of the oxypropylene polymer, those having a number average molecular weight (Mn) of 6,000 or more can be effectively used, but those having a number average molecular weight of 6,000 to 30,000 are preferred. Furthermore, in this oxypropylene polymer, the ratio (Mw / Mn) between the weight average molecular weight and the number average molecular weight is 1.6 or less, and the molecular weight distribution is extremely narrow (high monodispersity). The value of Mw / Mn is preferably 1.5 or less, more preferably 1.4 or less. The molecular weight distribution can be measured by various methods, and is usually determined by gel permeation chromatography (GPC).
Measurement by the method is common. Since the molecular weight distribution is narrow despite the large number average molecular weight, the composition of the present invention has a low viscosity before curing and is easy to handle, and shows good rubber-like elastic behavior after curing. .
In particular, a cured product of the composition of the present invention has higher elongation characteristics and breaking strength than a composition using an oxypropylene polymer having a reactive silicon group having a wide molecular weight distribution.

The oxypropylene polymer having a reactive silicon group serving as the component (A) of the present invention is preferably obtained by introducing a reactive silicon group into an oxypropylene polymer having a functional group.

The oxypropylene polymer having a high molecular weight and a narrow molecular weight distribution and having a functional group can be obtained by a usual polymerization method of oxypropylene (anionic polymerization method using caustic alkali) or a chain extension reaction method using this polymer as a raw material. Although it is extremely difficult, a special polymerization method
1-1197631, JP-A-61-215622, JP-A-61-215623, JP-A-61-218632
No., JP-B-46-27250 and JP-B-59-153
No. 36 or the like.
When a reactive silicon group is introduced, the molecular weight distribution tends to be broader than that of the polymer before the introduction, so that the molecular weight distribution of the polymer before the introduction is preferably as narrow as possible.

The introduction of the reactive silicon group may be performed by a known method. That is, for example, the following method is used.

(1) An oxypropylene 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 which are reactive with the functional group. Hydrosilylation is performed by reacting a hydrosilane having a hydrolyzable group on the reaction product.

(2) A oxypropylene 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 a terminal thereof, a functional group having reactivity with the Y functional group (Hereinafter referred to as Y 'functional group) and a compound having a reactive silicon group.

Examples of the silicon compound having a Y 'functional group include 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, γ-mercaptopropylmethyldimethoxysilane; γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, etc. Epoxysilanes; vinyl-type unsaturated group-containing silanes such as vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-acryloyloxypropylmethyldimethoxysilane; and γ-chloropropyltrimethoxysilane. Silanes containing chlorine atoms;
γ-isocyanatopropyltriethoxysilane, γ-
Isocyanate-containing silanes such as isocyanate propyl methyl dimethoxy silane; hydrosilanes such as methyl dimethoxy silane, trimethoxy silane, methyl diethoxy silane and the like can be specifically exemplified, but are not limited thereto. Absent.

Among the above methods, the method (1) or the method (2) of reacting a polymer having a terminal hydroxyl group with a compound having an isocyanate group and a reactive silicon group is preferable.

Phthalate ester plasticizer (hereinafter referred to simply as "ester plasticizer" ) used as component (B) in the present invention.
As also referred to), for example, dioctyl phthalate, dibutyl phthalate, and butyl benzyl phthalate ani
I can do it. It is also possible in addition to these ester plasticizer in combination with other plasticizers. Examples of plasticizers that can be used in combination include polyethers such as polypropylene glycol and derivatives thereof; polystyrenes such as poly-α-methylstyrene and polystyrene; polybutadiene, alkyd resin, butadiene-acrylonitrile copolymer, polychloroprene, polyisoprene, and polybutene. And a plasticizer such as chlorinated paraffins. Plasticizer alone or 2
It can be used arbitrarily in the form of a mixture of more than one kind.

The amount of the ester plasticizer is from 1 to 150 parts, preferably from 10 to 120 parts, per 100 parts (parts by weight, hereinafter the same) of the reactive silicon group-containing oxypropylene polymer.
Parts, particularly preferably 20 to 100 parts. The amount is 1
If it is less than the part, the effect as a plasticizer will not be exhibited,
If the amount exceeds 150 parts, there is a problem that the mechanical strength of the cured product is insufficient. When a plasticizer other than the ester plasticizer is used in combination, 50% of the ester plasticizer is contained in all the plasticizers.
Desirably, it is present in a weight percent or more.

[0025] The carbonated calcium Ru used as the component (C) of the present invention, colloidal calcium carbonate can be exemplified. The average particle size is 0 . 01-0.15 μm , calcium carbonate surface-treated with fatty acids .

As the calcium carbonate as the component (C), white luster O, carmos, white luster CC, white luster CCR,
Examples are those commercially available under trade names such as VIGOT-15.

Other fillers can be used in combination with the calcium carbonate used as the component (C) of the present invention. Examples of fillers that can be used in combination include reinforcing fillers such as fume silica, precipitated silica, silicic anhydride, hydrous silicic acid and carbon black; calcium carbonate, magnesium carbonate, diatomaceous earth, and calcined clay other than the component (C) of the present invention. , Clay, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, zinc oxide, activated zinc flower,
Fillers such as hydrogenated castor oil and shirasu balloon; fibrous fillers such as asbestos, glass fibers and filaments.

These fillers may be used alone or in combination of two or more.

The amount of calcium carbonate used as component (C) in the present invention is preferably 1 to 200 parts, more preferably 5 to 200 parts, per 100 parts of the reactive silicon group-containing oxypropylene polymer. When a filler other than the component (C) is used in combination, it is preferable that the component (C) is present in an amount of 50% by weight or more in all the fillers.

The curable composition of the present invention may be used by adding a curing catalyst, if necessary.

As curing catalysts, titanates such as tetrabutyl titanate and tetrapropyl titanate; tin carboxylate salts such as dibutyltin dilaurate, dibutyltin maleate, dibutyltin diacetate, tin octylate, tin naphthenate; dibutyltin oxide and phthalate Reaction products with acid esters; dibutyltin diacetylacetonate; organic aluminum compounds such as aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminum ethylacetoacetate; zirconium tetraacetylacetonate, titanium tetraacetylacetonate Chelate compounds of the formula: lead octylate; butylamine, octylamine, laurylamine, dibutylamine, Nolamine, 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 of these amine compounds with carboxylic acids and the like; Low molecular weight polyamide resin obtained from excess polyamine and polybasic acid; reaction product of excess polyamine and epoxy compound; γ-aminopropyltrimethoxysilane, N- (β
Silanol condensation catalysts such as silane coupling agents having an amino group such as -aminoethyl) 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 amount of these curing catalysts to be used is 0.1 to 100 parts of the reactive silicon group-containing oxypropylene polymer.
It is preferably about 1 to 20 parts, more preferably about 1 to 10 parts. If the amount of the curing catalyst used is too small relative to the amount of the reactive silicon group-containing oxypropylene polymer, the curing rate may be slow, and the curing reaction may not proceed sufficiently. On the other hand, if the amount of the curing catalyst is too large relative to the reactive silicon group-containing oxypropylene polymer, local heat generation or foaming occurs during curing, and it is difficult to obtain a good cured product, which is not preferable.

The method for preparing the curable composition of the present invention is not particularly limited. For example, the above-mentioned components are blended and kneaded at room temperature or under heat using a mixer, roll or kneader, or a suitable solvent is added. Use a small amount to dissolve the ingredients,
Ordinary methods such as mixing can be employed. Also, by appropriately combining these components, a one-pack or two-pack composition can be prepared and used.

When the curable composition of the present invention is exposed to the atmosphere, the curable composition forms a three-dimensional network by the action of moisture and cures into a solid having rubber-like elasticity.

In using the curable composition of the present invention, if necessary, an adhesion improver, a physical property modifier,
Storage stability improvers, anti-aging agents, ultraviolet absorbers, metal deactivators, ozone deterioration inhibitors, light stabilizers, amine radical chain inhibitors, phosphorus peroxide decomposers, lubricants, pigments,
Various additives such as a foaming agent can be appropriately added.

The curable composition of the present invention is particularly useful as an elastic sealant and can be used as a sealant for buildings, ships, automobiles, roads and the like. Further, since it can adhere to a wide range of substrates such as glass, porcelain, wood, metal, and resin moldings alone or with the aid of a primer, it can be used as various types of sealing compositions and adhesive compositions. . Further, it is also useful as an adhesive, a paint, a coating film waterproofing agent, a food packaging material, a cast rubber material, a molding material, and a foam material.

[0037]

According to the composition of the present invention, as compared with a composition using a polymer having a wide molecular weight distribution as the component (A), the cured product has higher elongation characteristics and breaking strength.

The reactive silicon group-containing oxypropylene polymer used as the component (A) in the curable composition of the present invention has a narrow molecular weight distribution despite its large number average molecular weight. Therefore, before curing, the composition of the present invention has a lower viscosity and is easier to handle than a conventional composition containing a reactive silicon group-containing oxypropylene polymer having the same molecular weight and a wide molecular weight distribution.

As described above, since the viscosity before curing is low, not only the workability is good, but also a large amount of filler can be blended to obtain an excellent room temperature curable composition.

Further, chemical resistance such as acid resistance is unexpectedly greatly improved, and solvent resistance and water resistance are also excellent.

[0041]

EXAMPLES In order to further clarify the present invention, examples are given below.

Synthesis Example 1 A 1.5-liter pressure-resistant glass reaction vessel was charged with a molecular weight of 15.0
00 polyoxypropylene triol (Mw / Mn =
1.38 g (0.081 equivalent) of 1.38 and a viscosity of 89 poise were charged and placed under a nitrogen atmosphere.

At 137 ° C., 19.1 g (0.099%) of a 28% methanol solution of sodium methoxide was added through a dropping funnel.
Was added dropwise and reacted for 5 hours, followed by devolatilization under reduced pressure.
Return under nitrogen atmosphere, 9.0 g of allyl chloride (0.118
Was added dropwise and reacted for 1.5 hours, and then 5.6 g of a 28% methanol solution of sodium methoxide (0.5 g) was added.
029 equiv) and 2.7 g of allyl chloride (0.035 equiv)
Allylation was carried out using.

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

270 g (0.065 equivalent) of this polymer
Was charged into a pressure-resistant glass reaction vessel 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 thereto, followed by stirring for 30 minutes. 6.24 g (0.059 equivalents) of dimethoxymethylsilane was added from a dropping funnel, reacted at 90 ° C. for 4 hours, and then devolatilized to obtain 260 g of a yellow transparent polymer.

Synthesis Example 2 A polyoxypropylene triol having a number average molecular weight of 15,000 (Mw / Mn = 1.38,
220 g (0.0447 equivalent) of viscosity and 89 g of dibutyltin dilaurate were charged, and 8.45 g (0.0447 equivalent) of γ-isocyanatopropylmethyldimethoxysilane was added dropwise at room temperature under a nitrogen atmosphere.
After the completion of the dropwise addition, the reaction was carried out at 75 ° C. for 1.5 hours. And IR spectrum, after confirming the formation of C = O absorption near disappearance 1730 cm ^-1 of the NCO absorption at about 2280 cm ^-1, the reaction was terminated. 213 g of a colorless and transparent polymer were obtained. 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-resistant reaction vessel made of pressure-resistant glass. Sodium hydroxide 40
g was added and reacted at 60 ° C. for 13 hours, and then 19 g of bromochloromethane was reacted at 60 ° C. for 10 hours. (The Mw / Mn of the obtained polymer is 2.1 and the viscosity is 38
5 poise. ).

Subsequently, 15 g of allyl chloride was added and reacted for 36 hours. After the completion of the reaction, the pressure was reduced to remove volatile substances.

The contents were taken out into 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
The ₆ · _6H 2 O 25g Isopropyl alcohol 500
g), and then added with 12 g of dimethoxymethylsilane and reacted at 80 ° C. for 4 hours. After the completion of the reaction, the pressure was reduced to remove volatile substances, and 550 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 at 23 ° C. using a B-type viscometer (BM type rotor No. 4, 12 rpm). The number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) of each polymer were analyzed by GPC. GPC was analyzed at a oven temperature of 40 ° C. using tetrahydrofuran as a distillation solvent in a column packed with polystyrene gel (manufactured by Tosoh Corporation). Table 1 shows the results.

[0050]

[Table 1]

Example 1 and Comparative Example 1 Polymer 10 obtained in Synthetic Example 1 or Comparative Synthetic Example 1
For 0 part, colloidal calcium carbonate (trade name "Shiraishika CCR" manufactured by Shiraishi Industry Co., Ltd., average particle size 0.08μ)
m) 155 parts, dioctyl phthalate 60 parts, antioxidant 2 parts, titanium dioxide (manufactured by Ishihara Sangyo Co., Ltd., trade name "R-820") 4 parts were added, kneaded well with three paint rolls, and then octyl. 3 parts of tin oxide and 0.5 part of laurylamine were added and kneaded uniformly. Among the obtained compositions, the composition of Example 1 (using the polymer of Synthesis Example 1) had a higher viscosity than the composition of Comparative Example 1 (using the polymer of Comparative Synthesis Example 1). It was low and easy to handle.

After a sheet having a thickness of 2 mm was prepared using these compositions, the sheet was heated at 23 ° C. for 2 days and then at 50 ° C. for 3 days.
Cured for days.

From this cured product sheet, JIS K630
Punch No. 3 dumbbell according to 1 and pulling speed 50
A tensile test was performed at 0 mm / min. Table 2 shows the results. In the table, M100 is the stress at 100% elongation, TB
Represents breaking strength, and EB represents elongation at break.

[0054]

[Table 2] As is clear from Table 2, the composition of the present invention has excellent breaking strength as compared with the case where the oxypropylene polymer having a wide molecular weight distribution is used.

Reference Examples 1, 2 Polymer 10 obtained in Synthesis Example 1 or Comparative Synthesis Example 1
To 0 part, 3 parts of tin octylate, 0.5 part of laurylamine, and 0.6 part of pure water were added and mixed well, and a tensile test was performed in the same manner as in Example 1 and Comparative Example 1. Table 3 shows the results.

[0056]

[Table 3] As is clear from Tables 2 and 3, when an oxypropylene polymer having a wide molecular weight distribution was used, the cured product obtained by adding the composition to the composition without the addition of the ester plasticizer and calcium carbonate had a somewhat improved tensile strength. Has characteristics. On the other hand, when the oxypropylene polymer having a narrow molecular weight distribution is used, the improvement in the tensile properties, particularly the improvement in the breaking strength is remarkable.

Example 2 A curable composition was obtained in the same manner as in Example 1 except that the polymer obtained in Synthesis Example 2 was used instead of the polymer obtained in Synthesis Example 1. The cured product of this composition also had excellent tensile properties.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-43449 (JP, A) JP-A-61-37839 (JP, A) JP-A-59-138259 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C08L 71/00-71/14

Claims (4)

(57) [Claims] (A) The polymer main chain is represented by the following formula: In consists repeating unit represented, a oxypropylene polymer having at least one silicon atom-containing group containing bound silicon atom of a hydroxyl group or a hydrolyzable group, M
An oxypropylene polymer having a w / Mn of 1.6 or less and a number average molecular weight of 6,000 or more, (B) a phthalate ester-based plasticizer, and (C) an average particle diameter of 0.1 treated with a fatty acid. 0
1 to 0.15 μm or less of calcium carbonate, and 100 parts by weight of the component (A) and the component (B) 1
A curable composition comprising -150 parts by weight and 1-200 parts by weight of the component (C). 2. The polymer of component (A) has a Mw / Mn of 1.5.
The curable composition according to claim 1, wherein: 3. The polymer of component (A) has a number average molecular weight of 6,
The curable composition according to claim 1, wherein the amount is from 000 to 30,000. 4. The polymer according to claim 1, wherein a silicon atom-containing group is present at a molecular chain terminal in the polymer of the component (A).
The curable composition according to item.