CURABLE COMPOSITION

Abstract

A curable composition includes an organic polymer containing a reactive silicon group (A), and a bound substance of kaolinite and quartz (B) at a proportion of 30-200 parts by weight relative to 100 parts by weight of the organic polymer containing a reactive silicon group (A).

Claims

1. A curable composition comprising an organic polymer containing a reactive silicon group (A), and a bound substance of kaolinite and quartz (B) at a proportion of 30-200 parts by weight relative to 100 parts by weight of the organic polymer containing a reactive silicon group (A).

2. The curable composition according to claim 1, wherein the organic polymer containing a reactive silicon group (A) comprises a reactive silicon group-containing polyoxyalkylene-based polymer (A1) and/or a reactive silicon group-containing (meth)acrylate-based polymer (A2).

3. The curable composition according to claim 1, wherein the organic polymer containing a reactive silicon group (A) comprises a polyoxyalkylene-based polymer (a1) and/or a (meth)acrylate-based polymer (a2) as a main chain.

4. (canceled)

5. The curable composition according to claim 1, wherein the bound substance of kaolinite and quartz (B) has a kaolinite content of not more than 15 wt %.

6. The curable composition according to claim 1, wherein the bound substance of kaolinite and quartz (B) has a D.sub.50 particle size of 1-3 m.

7. The curable composition according to claim 1, wherein the bound substance of kaolinite and quartz (B) is calcined.

8. The curable composition according to claim 1, wherein the bound substance of kaolinite and quartz (B) is surface-treated.

9. The curable composition according to claim 1, further comprising an epoxy group-containing silane coupling agent (C) and an amidine compound (D).

10. The curable composition according to of claim, further comprising an organotin-based compound.

11. An adhesive comprising the curable composition according to claim 1.

12. A cured product obtained by curing the curable composition according to claim 1.

13. An adhered structure of wood and a cured product obtained by curing the curable composition according to claim 1.

Description

EXAMPLES

[0175] While the present invention is explained in more detail in the following by referring to Examples, the present invention is not limited by the following Examples.

Synthetic Example 1

[0176] Using polyoxypropylene triol having a number average molecular weight of about 3,000 as an initiator, propyleneoxide was polymerized by a zinc hexacyanocobaltate glyme complex catalyst to give polyoxypropylene triol having a number average molecular weight of 26,000. Then, a solution of NaOMe (sodium methoxide) (1.2 equivalents relative to a hydroxyl group of the hydroxyl group terminal polyoxypropylene triol) in methanol was added and methanol was evaporated. 3-Chloro-1-propene (1.2 equivalents relative to the hydroxyl group) was added to convert the terminal hydroxyl group to an allyl group. To the obtained allyl group terminal polyoxypropylene (500 g) was added platinum divinyldisiloxane complex (3 wt % isopropanol solution based on platinum) (50 l), and TES (triethoxysilane) (8.5 g) was slowly added dropwise with stirring. The mixed solution was reacted at 90 C. for 2 hr, and unreacted TES was evaporated under reduced pressure. Furthermore, methanol (100 g) and HCl (12 ppm) were added to convert the terminal ethoxy group to a methoxy group at 90 C. to give reactive silicon group-containing polyoxypropylene polymer (A-1) containing a trimethoxysilyl group on the terminal and 2.0 silicon groups on average per 1 molecule.

Synthetic Example 2

[0177] Isobutanol (51.1 parts by weight) was placed in a four-mouthed flask provided with a stirring machine, and the temperature was raised under a nitrogen atmosphere to 105 C. A mixed solution of methyl methacrylate (65.0 parts by weight), 2-ethylhexyl acrylate (25.0 parts by weight), 3-methacryloxypropyltrimethoxysilane (10.0 parts by weight), 3-mercaptopropyltrimethoxysilane (8.0 parts by weight), and 2,2-azobis(2-methylbutyronitrile) (2.5 parts by weight) in isobutanol (22.7 parts by weight) was added dropwise thereto over 5 hr. Polymerization was performed at 105 C. for 2 hr to give an isobutanol solution (solid content 60%) of reactive silicon group-containing (meth)acrylic polymer (A-2) having 1.6 silicon groups on average per 1 molecule and a number average molecular weight of 2,100.

Examples 1-4

Comparative Examples 1-4

[0178] The reactive silicon group-containing polyoxypropylene polymer (60.0 parts by weight) obtained in Synthetic Example 1 and an isobutanol solution (66.7 parts by weight) of the reactive silicon group-containing (meth)acrylic polymer obtained in Synthetic Example 2 were mixed, isobutanol was evaporated under reduced pressure to give reactive silicon group-containing organic polymer (A) having a polymer weight ratio (A-1)/(A-2)=60/40.

[0179] Respective components shown in the following Table 1 were mixed at the amounts shown in the following Table to give a curable composition. In the Table, numerical values other than the test results are in parts by weight.

[0180] Using the thus-obtained curable compositions, the following adhesiveness evaluation was performed. The results are shown in Table 1.

(Initial Shear Strength)

[0181] Beechwood (3 mm25 mm100 mm) was used as an adherend and, as a pre-treatment, the surface was smoothed with P100 sandpaper. A curable composition as an adhesive was applied to the beechwood by using Sellotape (No. 405) manufactured by NICHIBAN at a thickness of 50 over the area of 2510 mm. With an open time being 0 min, an adherend was adhered immediately after application and fixed with a bulldog clip (manufactured by KOKUYO, width 20 mm). Thereafter, it was aged under 23 C. 50% RH conditions for 1 week. Then, a tensile test was performed by AR-5422 manufactured by Shimadzu Corporation. The test speed was 50 mm/min.

(Shear Strength After Water-Resistant Test)

[0182] Industrial water (about 20 L) was placed in a metal container (about 50 cm40 cmheight 40 cm), and the adherend produced and fixed with the clip as mentioned above was immersed in water at room temperature. The adherend was stood in this state for 4 days and a tensile test was performed by AR-5422 manufactured by Shimadzu Corporation. The test speed was 50 mm/min.

TABLE-US-00001 TABLE 1 Comp. Comp. Comp. Comp. Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 1 Ex. 2 Ex. 3 Ex. 4 polymer organic 100 100 100 100 100 100 100 100 polymer A bound substance of kaolinite and Aktifit VM 50 100 100 quartz (calcined) bound substance of kaolinite and Sillitin 100 quartz (uncalcined) Z-86 kaolin ASP-170 50 calcium carbonate C110S 50 100 100 dehydrating agent A-171 5 6.7 6.7 6.7 5 5 6.7 6.7 MS curing catalyst S-1 1 0.1 0.1 0.3 1 1 0.1 0.3 amidine compound DBU 2 2 2 epoxy silane A-187 5 4 4 5 5 4 aminosilane A-1120 2 2 2 2 2 epoxy resin JER 828 20 20 20 epoxy curing agent H-30 13.8 13.8 13.8 antioxidant IRGANOX 1 1 1 1 1 1 1 1 1010 initial shear strength (MPa) 13.83 9.75 7.65 9.64 11.48 12.11 4.55 5.69 shear strength (MPa) after 3.27 4.26 3.76 3.32 2.29 2.26 3.67 2.69 water-resistant test

[0183] In Table 1, each additive was as follows. Aktifit VM: vinylsilane-treated calcined Sillitin (kaolinite content: 10 wt %, D.sub.50 particle size: 2.0 m) manufactured by Hoffmann Mineral

[0184] Sillitin Z-86: uncalcined Sillitin (kaolinite content: 30 wt %, D.sub.50 particle size: 1.9 m) manufactured by Hoffmann Mineral

[0185] ASP-170: kaolin manufactured by BASF

[0186] C110S: surface-treated ground calcium carbonate manufactured by Imerys

[0187] A-171: vinyltrimethoxysilane manufactured by Momentive

[0188] S-1: dioctyltin compound manufactured by NITTO KASEI

[0189] DBU: 1,8-diazabicyclo[5.4.0]undec-7-ene manufactured by Tokyo Chemical Industry

[0190] A-187: -glycidoxypropyltrimethoxysilane manufactured by Momentive

[0191] A-1120: N--aminoethyl--aminopropyltrimethoxysilane manufactured by Momentive

[0192] JER 828: bisphenol A type epoxy resin manufactured by Mitsubishi Chemical Corporation

[0193] H-30: ketimine manufactured by Mitsubishi Chemical Corporation

[0194] IRGANOX 1010: hindered phenol-based antioxidant manufactured by BASF

[0195] A comparison of Example 1 and Comparative Examples 1, 2 reveals that a curable composition containing a bound substance of kaolinite and quartz shows good shear strength even after the water-resistant test. This shows that a firm intermolecular force acts between the curable composition of Example 1 and the wood, and maintains adhesiveness even after the water-resistant test. In addition, a comparison of Examples 2 and 3 reveals that a calcined product (component (B)) having a kaolinite content of not more than 15% is superior in the initial shear strength, and shear strength after water-resistant test.

[0196] This application is based on a patent application No. 2014-010525 filed in Japan, the contents of which are incorporated in full herein.

[0197] Although the disclosure has been described with respect to only a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that various other embodiments may be devised without departing from the scope of the present invention. Accordingly, the scope of the invention should be limited only by the attached claims.