JP2000038560A - Moisture-curing adhesive composition excellent in transparency - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide modified silicone resin based moisture-curing adhesive compositions which show good extrusion characteristics from an adhesive container and give excellent transparency and polymer internal reinforcement and good adhesion after curing. SOLUTION: A moisture-curing adhesive composition comprises a polyoxypropylene based modified silicone resin containing an acrylic polymer having a silicon atom-containing functional group, a curing agent therefor, a hydrophobic fine powdered silica and a silane coupling agent containing an amino group. It is preferred that the amounts of the curing agent, the fine powdered silica and the coupling agents are 0.1-10 pts.wt., 2-50 pts.wt. and 0.1-10 pts.wt., respectively, based on 100 pts.wt. modified silicone resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a modified silicone resin-based moisture-curable adhesive composition having excellent transparency.

[0002]

2. Description of the Related Art A polymer having a silicon atom-containing reactive group crosslinks and cures in the presence of moisture. Among these polymers, for example, a curable composition using a polymer having a main chain skeleton of polyoxypropylene is used. Is a liquid at room temperature and has the property of becoming a rubber elastic body upon curing, and is widely used in architectural sealants, industrial sealants, elastic adhesives and the like. By mixing silica fine powder with the composition comprising the polyoxypropylene-type modified silicone resin and the curing agent as described above, a technique for improving the viscosity, reinforcing the cured product, and improving the transparency is known. ing. However, in the above-mentioned compounding system, there is a defect that the adhesiveness is poor, and in order to improve the adhesiveness, it is common to mix a coupling agent such as aminosilane, but by adding the coupling agent. It significantly reduces the transparency of the cured product.

[0003]

The present invention shows good extrudability from containers such as cartridges and tubes until curing, and after curing, excellent transparency and reinforcing properties of the cured product and good It is an object of the present invention to provide a modified silicone resin-based moisture-curable adhesive composition that provides excellent adhesion.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies on a composition system comprising the above modified silicone resin, curing agent, silica fine powder and aminosilane. As a result, the modified silicone resin contains a silicon atom-containing functional group. The present inventors have found that the object of the present invention can be achieved by using a hydrophobic silica fine powder as a silica fine powder for a polyoxypropylene-type modified silicone resin containing an acrylic polymer having a group, and completed the present invention. Furthermore, it has been found that by using hydrophobic silica fine powder obtained by treating the silica fine powder with a specific silicon compound, the transparency of the cured product is remarkably improved.

That is, the present invention provides (1) a polyoxypropylene-type modified silicone resin containing an acrylic polymer having a silicon atom-containing functional group, (2) the curing agent of the above (1), (3) a finely divided hydrophobic silica, (4) A moisture-curable adhesive composition containing a silane coupling agent having an amino group.

[0006] The moisture-curable adhesive composition of the present invention comprises:
Per 100 parts by weight of the modified silicone resin, the curing agent is 0.1 to 10 parts by weight, the finely divided silica is 2 to 50 parts by weight, and the coupling agent is 0.1 to 10 parts by weight. I do. The moisture-curable adhesive composition of the present invention is characterized in that the finely divided silica is obtained by treating fumed silica with hexamethyldisilazane.
The moisture-curable adhesive composition of the present invention is characterized in that the finely divided silica is obtained by treating silica airgel with dimethylsiloxane and / or hexamethyldisilazane.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A polyoxypropylene-type modified silicone resin containing a silicon atom-containing functional group-containing acrylic polymer (hereinafter referred to as component (a)), which is one component of the composition of the present invention, contains a silicon atom-containing compound. It is a mixture of an acrylic polymer having a functional group (hereinafter, referred to as component (a-1)) and a polyoxypropylene-type modified silicone resin (hereinafter, referred to as component (a-2)).

The component (a-1) has the general formula [-CH ₂ -C
(R) (COOR ¹ )-] (where R represents a hydrogen atom or a methyl group, and R ¹ represents an alkyl group having 1 to 20 carbon atoms). It is a polymer and has a silicon atom-containing functional group. Examples of R ¹ include methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, hexadecyl and the like.

The component (a-1) represented by the above general formula is
For example, (1) the general formula [CH ₂ ＣC (R) (COO
R ¹ )] (wherein, R and R ¹ have the same meanings as described above) by converting the (meth) acrylate monomer represented by the general formula [CH ₂ ＣC (R) —Q _n —Si (CH ₃ )
(X) _3-n ] (wherein R is as defined above, and Q is -COO
R ^2- (R ² is a divalent alkylene group having 1 to 6 carbon atoms), n is an integer of 0, 1 or 2, and X is a hydrolyzable group (preferably a halogen atom or an alkoxy group). )
The polymerization is carried out in the presence of a compound having a polymerizable unsaturated bond and a reactive silicon atom-containing functional group represented by the formula (2), or (2) the polymerizable unsaturated bond and the reactive functional group After copolymerizing a compound having a group,
It can be produced by reacting with a compound having a functional group capable of reacting with the silicon atom-containing functional group and the polymerizable unsaturated bond and the reactive functional group.

The compound having a polymerizable unsaturated bond and a reactive functional group which can be used in the method (2) includes allyl (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6 Hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate and the like, which can also react with the above-mentioned silicon atom-containing functional group and the polymerizable unsaturated bond and the reactive functional group. As the compound having a functional group, particularly as a hydrosilane compound, trichlorosilane, methyldichlorosilane, halogenated silane such as trimethylsiloxydichlorosilane, trimethoxysilane, triethoxysilane, alkoxysilane such as phenyldimethoxysilane,
Acyloxysilanes such as methyldiacetoxysilane and trimethylsiloxymethylacetoxysilane, ketoximesilanes such as bis (dimethylketoximeto) methylsilane, bis (cyclohexylketoxymate) methylsilane, and hydrosilanes such as dimethylsilane and trimethylsiloxymethylsilane And alkenyloxysilanes such as methyltri (isopropenyloxy) silane.

The component (a-2) is a polymer having a repeating unit of oxypropylene represented by the general formula [—CH (CH ₃ ) CH ₂ —O—] in its molecule, and comprises a silicon atom-containing functional group. Group, preferably an alkoxysilyl group such as a methoxysilyl group and an ethoxysilyl group. Component (a-2) has a number average molecular weight of 4,000 to 30,00.
A value of 0 is preferred. Such a component (a-2)
For example, Japanese Patent Publication Nos. 45-36319 and 46-1215.
No. 4, JP-A-50-156599, JP-A-54-6096
Nos. 55-13468, 55-13767, 57-164123, 61-197631, and 6
1-215622, 61-2215623, 61-
Although it can be manufactured by the method described in each gazette such as No. 218632, there are also commercially available products such as Kanebuchi Chemical Industry Co., Ltd. product name: Cyril 5A03, MS polymer, Asahi Glass Co., Ltd. product name: Exter 2410 etc. , They can also be used.

The component (a) is a mixture of the above-mentioned component (a-1) and the above-mentioned component (a-2). The mixing ratio of the two is 100 parts by weight of the above-mentioned component (a-2). Component (a-1) is 10 to 500 parts by weight. Such a component (a) consisting of a mixture ratio of the above-mentioned component (a-1) and the above-mentioned component (a-2) is commercially available. For example, trade names: Cyril MA430, Cyril MA44, manufactured by Kanegafuchi Chemical Industry Co., Ltd.
They can be used, such as 0. Component (a) is
Two or more different types can be used in combination.

As the curing catalyst of the above component (a) (hereinafter referred to as component (b)), organotin, metal complexes, basic substances and organic phosphoric compounds can be used. Specifically, examples of the organic tin include dibutyltin dilaurate, dioctyltin dimaleate, dibutyltin phthalate, stannous octylate, dibutyltin methoxide, dibutyltin diacetylacetate, and dibutyltin diversate. Examples of the metal complex include titanate compounds such as tetrabutyl titanate, tetraisopropyl titanate, and triethanolamine titanate; metal carboxylate such as lead octylate, lead naphthenate, nickel naphthenate, and cobalt naphthenate; and aluminum acetylacetonate complex. And metal acetylacetonate complexes such as vanadium acetylacetonate complex. Examples of the basic substance include quaternary ammonium salts such as tetramethylammonium chloride and benzalkonium chloride, and a plurality of nitrogen-containing linear or cyclic salts such as DABCO (registered trademark) series and DABCO BL series manufactured by Sankyo Air Products. Of tertiary amines and quaternary ammonium salts. Examples of the organic phosphoric acid compound include monomethyl phosphoric acid, di-n-butyl phosphoric acid, and triphenyl phosphate.

Examples of the hydrophobic fine powdered silica (hereinafter referred to as component (c)) used in the present invention include fumed silica (fumed silica) which is often used as a thixotropic agent in adhesives and the like. Fine powdered silica such as silica airgel is treated with an organic silicon compound, for example, dimethyldichlorosilane, hexamethyldisilazane, dimethylsiloxane, trimethoxyoctylsilane, etc., and can be made hydrophobic. Those treated with hexamethyldisilazane and those treated with silica airgel with dimethylsiloxane and / or hexamethyldisilazane are preferred.

The hydrophobizing treatment is carried out by stirring the finely divided silica and the organic silicon compound at a high speed of about 100 to 400 ° C. It is desirable to carry out the contact in a medium such as an organic solvent in order to uniformly contact the two. The contact ratio between the finely divided silica and the organic silicon compound is usually 3 to 40 parts by weight of the organic silicon compound per 100 parts by weight of the finely divided silica.

The silane coupling agent having an amino group (hereinafter referred to as component (d)) used in the present invention includes a primary or secondary amino group, preferably a primary amino group, A silane compound having an alkoxy group is preferable, for example, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyl-methyldiethoxysilane, γ-aminopropyl-methyldimethoxysilane, N-phenyl -Γ-
Aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-
β (aminoethyl) -γ-aminopropyltriethoxysilane, N-β (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) -γ
-Aminopropylmethyldiethoxysilane, and other special aminosilanes manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM
6063, X-12-896, KBM576, X-12
-565, X-12-580, X-12-806, X-
12-666, X-12-5263, KBM6123,
X-12-577, X-12-575, X-12-56
3B, X-12-562 and the like.

The adhesive composition of the present invention comprises the modified silicone resin (component (a)), the curing agent (component (b)),
It comprises the finely divided silica (component (c)) and the coupling agent (component (d)).
The component ratios are 0.1 to 10 parts by weight of component (b) and 2 to 50 parts by weight of component (c) per 100 parts by weight of component (a).
It is desirable that the amount of component (d) be 0.1 to 10 parts by weight. If the amount of the component (b) is less than 0.1 part by weight per 100 parts by weight of the component (a), the curing rate is too low. If the amount of the component (c) is less than 2 parts by weight, the effect of reinforcing the effected product cannot be sufficiently obtained. When the amount of the component (d) is less than 0.1 part by weight, the effect of imparting adhesiveness is not sufficient. When the amount exceeds 10 parts by weight, the curability is lowered, which is not preferable.

The composition of the present invention having the above constitution may be added to an adhesive, for example, if necessary, for example, a plasticizer, various additives, a solvent, a dehydrating agent and the like. As a plasticizer, dioctyl phthalate, dibutyl phthalate, dioctyl adipate, dibutyl adipate, etc., as various additives, an antioxidant, an ultraviolet absorber, a pigment, various tackifiers, etc., as a solvent,
Examples of various organic solvents and dehydrating agents having a water content of 500 ppm or less include quicklime, orthosilicate, anhydrous sodium sulfate, methylsilicate, ethylsilicate, and vinyltrimethoxysilane.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. Various compounds used in Examples and Comparative Examples are as follows. Component (a) Cyril MA430: trade name of Kanebuchi Chemical Co., Ltd. Component (b) No. 918 (dibutyltin dilaurate): product name (c) manufactured by Sankyoki Gosei Co., Ltd. R972 (fumed silica hydrophobically treated with dimethyldichlorosilane): product name R812 manufactured by Nippon Aerosil Co., Ltd. (hydrophobic treatment with hexamethyldisilazane) Smoke-free silica): Product name manufactured by Nippon Aerosil Co., Ltd. Silohovic 200 (Silica aerogel hydrophobically treated with dimethylsiloxane): Product name manufactured by Fuji Silysia Chemical Ltd. Component (d) KBE903 (γ-aminopropyltriethoxysilane): Shin-Etsu Chemical industry Co., trade name other MS203 (polypropylene type modified silicone resin):
A200 (untreated fumed silica) manufactured by Shin-Etsu Chemical Co., Ltd .: manufactured by Nippon Aerosil Co., Ltd. The evaluation method of the composition of the present invention was as follows.

The absorbance of the cured product at a wavelength of 500 nm was measured and evaluated according to the following criteria. ◎: what absorbance of less than 0.2 ○: what absorbance of less than 0.2 to 0.5 △: what absorbance of less than 0.5 to 1.0 ×: cured absorbance of 1.0 or more of It was measured of dumbbell physical properties JIS K6301 in accordance with tensile strength. Bead adhesion to acrylic plate The composition was applied in a bead form on an acrylic resin plate, and
After leaving still at 14 ° C. and RH 50% for 14 days, the bead was peeled off from the end by hand, and the peeled state was observed. ：: cohesive failure ×: interfacial fracture viscosity The viscosity of the composition before curing was measured using a BH type viscometer (Rotor 7) at a rotation speed of 10 rpm and 23 ° C. Workability The composition in which the composition had not been cured was placed in a tube and extruded by hand, and the ease of extrusion at that time was observed, and judged according to the following criteria. ：: easy to extrude. X: Hard to extrude.

Examples 1-4 Components (a) shown in Table 1
The components (b), (c) and (d) were mixed in the proportions shown in Table 1 (all parts by weight, hereinafter the same) to obtain the composition of the present invention. The physical properties of the obtained composition were measured as described above, and the results are shown in Table 1. Further, the obtained composition is cured, and the physical properties of the cured product are measured as described above,
The results are shown in Table 1.

(Comparative Examples 1 and 2) A composition was obtained in the same manner as in Example 1 or 2, except that the component (c) was changed to A200 which was untreated fine powdered silica. The physical properties of the obtained composition and its cured product were measured as described above, and the results are shown in Table 1.
It was shown to.

(Comparative Example 3) Component (a) was added to MS203, which is a modified polypropylene resin, and component (c) was added.
Was replaced with A200 which is untreated fine powdered silica, and a composition was obtained in the same manner as in Example 1 except that KBE903 as the component (d) was not used. The physical properties of the obtained composition and its cured product were measured as described above, and the results are shown in Table 1.

(Comparative Example 4) Component (a) was added to MS203 which is a modified polypropylene resin of the type, and component (c) was added.
Was obtained in the same manner as in Example 1 except that A200, which was untreated fine powdered silica, was used. The physical properties of the obtained composition and its cured product were measured as described above, and the results are shown in Table 1.

[0025]

[Table 1] From Table 1, it can be seen that the cured product of the composition of the present invention shows excellent transparency, and in particular, a composition using fumed silica treated with hexamethyldisilazane and silica airgel treated with dimethylsiloxane as hydrophobic finely divided silica. It can be seen that the effect is remarkable. In addition, it can be seen that the composition of the present invention is excellent in extrusion workability, and the cured product is also excellent in reinforcing property and adhesiveness. Furthermore, by using an increased amount of silica airgel treated with dimethylsiloxane, a tougher cured product can be obtained without impairing the viscosity (workability).

On the other hand, those using finely divided silica which is not subjected to a hydrophobic treatment have a high viscosity and are therefore inferior in workability and poor in transparency. When the amount of the fine powder silica is increased, it becomes extremely difficult to prepare a cured product, and the transparency is extremely deteriorated. Also, as a modified silicone resin, if a polypropylene-type modified silicone resin is used and no aminosilane is used, the transparency of the cured product is excellent, but its rigidity is low,
Poor adhesion. When aminosilane is used, adhesiveness is improved, but transparency is deteriorated.

[0027]

The composition of the present invention is excellent in extrusion workability, and its cured product exhibits extremely excellent transparency, as well as excellent reinforcing properties and adhesiveness.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J040 DF041 DF051 DF061 DF062 DN061 DN062 EF042 EF052 EK111 EK112 GA03 GA08 GA29 GA31 HA306 HB07 HB20 HB24 HB27 HC01 HC20 HD24 HD27 HD36 HD42 HD43 JB04 KA03 KA07 KA07

Claims (4)

[Claims] 1. A polyoxypropylene-type modified silicone resin containing an acrylic polymer having a silicon atom-containing functional group, (2) the curing agent of the above (1), (3) a finely divided hydrophobic silica, and (4) A moisture-curable adhesive composition containing a silane coupling agent having an amino group. 2. The curing agent is 0.1 to 10 parts by weight, the finely divided silica is 2 to 50 parts by weight, and the coupling agent is 0.1 to 1 part by weight per 100 parts by weight of the modified silicone resin.
2. The moisture-curable adhesive composition according to claim 1, wherein the amount is 0 part by weight. 3. The moisture-curable adhesive composition according to claim 1, wherein the fine silica powder is obtained by treating fumed silica with hexamethyldisilazane. 4. The finely divided silica obtained by treating silica airgel with dimethylsiloxane and / or hexamethyldisilazane.
The moisture-curable adhesive composition as described in the above.