JPH04168186A - One-pack type urethane-based adhesive for tile - Google Patents

Abstract

PURPOSE:To obtain the subject adhesive excellent in adhesion to wet surfaces, slippage resistance of tiles and storage stability by blending an active isocyanate group-containing urethane prepolymer with a moisture absorbing plasticizer, silica and a surface-treated calcium carbonate. CONSTITUTION:The objective adhesive is obtained by blending (A) an active isocyanate group-containing urethane prepolymer prepared by reacting a polyether polyol with an excess polyisocyanate compound with (B) 1-15wt.% moisture absorbing plasticizer preferably expressed by the formula (R1O is monohydric alcohol residue; R2 is 1-8C alkyl or 1-4C alkylcarbonyl; n is 7-50; m is 0-6), (C) 1-10wt.% silica and (D) 5-30wt.% surface-treated calcium carbonate. Furthermore, the aforementioned adhesive is in conformity with the JIS specifications.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a one-component urethane adhesive for tiles, and more specifically, to a one-component urethane adhesive for tiles, which has particularly excellent wet surface adhesion, tile shear resistance, and storage stability, and which complies with JIS standards. This invention relates to a novel compatible one-component urethane adhesive for tiles.

PRIOR ART AND PROBLEMS TO BE SOLVED BY THE INVENTION Tile adhesives are generally standardized in JIS A-5548, in which adhesives applied to wet base materials are categorized as Type I. Traditionally, two-component epoxy adhesives have been used as adhesives for tiles of this type.However, there are many operational problems such as problems and skin rashes caused by mixing the two components. There is.

The present inventors conducted intensive studies to solve the above-mentioned problems with two-component epoxy adhesives and to develop a new type I tile adhesive that complies with the JIS A-5548 standard. By blending a hygroscopic plasticizer, silica, and surface-treated calcium carbonate with a group-containing urethane prepolymer, a one-component product that does not cause any operational problems and has particularly good wet surface adhesion, tile shear resistance, and storage stability can be obtained. The present inventors have discovered that a urethane adhesive for tiles can be obtained that can exhibit superior performance on surfaces, and have completed the present invention.

That is, the present invention relates to an active isocyanate group-containing urethane prepolymer (hereinafter referred to as NG) obtained by reacting a polyether polyol with an excess polyisocyanate compound.
The present invention provides a corrugated urethane adhesive for tiles, which is characterized by blending a hygroscopic plasticizer, silica, and surface-treated calcium carbonate into an O-containing prepolymer (referred to as an O-containing prepolymer).

The NCO-containing prepolymer in the present invention contains a polyether polyol and an excess of a polyisocyanate compound, that is, the hydroquine group (OH
), for example, I
70-10 at the ratio of 3≦NG Olo H≦10
It is produced by reacting at 0°C for several hours and is usually N
The GO content is adjusted to 5 to 25% (weight %, the same applies hereinafter).

In this reaction, a conventional catalyst, plasticizer or solvent may be used.

Examples of the polyether polyol include low molecular weight active hydrogen compounds having two or more active hydrogen atoms (for example, diols such as ethylene glycol, propylene glycol, butylene glycol, 6-hexanediol, glycerin, trimethylolpropane, 2.
obtained by ring-opening polymerization of propylene oxide and ethylene oxide in the presence of one or more of triols such as 6-hexandriol, and amines such as ammonia, methylamine, ethylamine, propylamine, and butylamine. Examples include polyoxytetramethylene glycol obtained by ring-opening polymerization of random or block copolymer polyoxyethylene-propylene polyol or tetrahydrofuran, and usually have a molecular weight of 300 to 7000. May be used.

Examples of the polyisocyanate compounds include aliphatic polyisocyanates such as hexamethylene diisonanate and lysine methyl ester diisocyanate, alicyclic polyisocyanates such as hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, and hydrogenated tolylene diisocyanate, and tolylene diisocyanate. Isocyanate (TDI), diphenylmethane diisocyanate (MD
I), aromatic isocyanates such as naphthylene diisocyanate, xylylene diisocyanate, and mixtures thereof. Particularly preferred polyisocyanate compounds are aromatic polyisocyanates, such as TDI and MDI.

The hygroscopic plasticizer blended in the present invention is a component that improves wet surface adhesion, and specifically, for example, monohydric alcohol (methanol, ethanol, butanol, propyl alcohol, etc.) with propylene oxide or propylene Terminal O of polyalkylene ether polyol made by addition polymerization of oxide and ethylene oxide
H is alkylated or esterified, with the formula: [In the formula, R and O are monohydric alcohol residues, and R7 is
-8 alkyl group or C1-C4 alkylcarbonyl group, n is 7-50, and m is 0-6]. Such compounds usually have a molecular weight of 400 to 5000, preferably 1000 to 300.
0 may be used. The blending amount is usually 1-15%, preferably 2-15% of the total amount of the adhesive component (the same applies below).
It may be selected within a range of 10%. If it is less than 1%, the desired effect of improving wet surface adhesion cannot be obtained, and if it exceeds 15%, storage stability tends to decrease.

The silica blended in the present invention is a component that imparts normal thixotropy, and the blending amount is usually 1 to 10%, preferably 2%.
It may be selected within the range of ~5%.

Although the desired thixotropy is expressed by the above-mentioned combination of glue forces, silica alone tends to have poor stability during adhesive storage and a concomitant decline in speciation effect.To prevent this, Surface treated calcium carbonate (for example, surface treated with a fatty acid ester treatment agent) (hereinafter referred to as
Used in combination with treated charcoal (called treated charcoal). The blending amount of such treated charcoal may be selected in the range of usually 5 to 30%, preferably 10 to 20%.

The one-component urethane adhesive for tiles according to the present invention is composed of the above-mentioned NCO-containing prepolymer and a predetermined amount of a hygroscopic plasticizer, silica, and treated charcoal, and if necessary, Common fillers (clay, talc, silica sand, slate powder, etc.), plasticizers (phthalate esters such as di-n-octyl phthalate (DOP) and dibutyl phthalate, di-n-butyl ambate and diasodecyl azide) Adipate esters such as esters), curing accelerating catalysts (dibutyltin dilaurate (DBTDL), triethylamine, lead octylate, etc.), high boiling point solvents, adhesion agents (e.g. epoxyalkoxysilane), etc. may be blended in appropriate amounts. .

The adhesive of the present invention, which has a structure that exceeds the effects of the invention, can be used for various base materials [e.g., mortar board, asbestos slate (flexible board), inorganic board (gypsum board, silica board), plywood, etc.]. It can be used to bond tiles of two-part stone quality, without the problems of poor mixing and skin irritation of conventional two-component epoxy adhesives, and has good wet surface adhesion, tile shear resistance, and storage stability. It is an extremely useful tile adhesive that exhibits excellent effects in terms of properties and fully complies with JIS A-5548 standards.

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Examples 1 to 3 and Comparative Examples 1 to 3 (1) Production of NGO-containing prepolymer Polyoxypropylene triol 29 with a molecular weight of 3000
4,4°-
Diphenylmethane diisocyanate-based compound (manufactured by Sumitomo Bayer Co., Ltd., Crude MDI) 4409 was added, and 80
The reaction was carried out for 5 hours at °C to obtain an NGO-containing prepolymer with an NGO content of 12.1% and a viscosity of 6000 cps/20 °C.

(2) Preparation of adhesive for tiles To the NGO-containing prepolymer of (1) above, various components (parts by weight) shown in Table 1 below were added, stirred and defoamed, and then a small amount of high boiling point solvent (mineral spirit, b.

The tile adhesive is prepared by adjusting the viscosity at 170-200°C). In Comparative Example 3, a commercially available two-component epoxy adhesive (Penguin Cement 1021, manufactured by Sunstar Giken Co., Ltd.) was used.

(3) Performance test Regarding the tile adhesive mentioned in (2) above, the adhesive strength (JI
SA-5548), storage stability (40℃ x
(2 weeks) and the slip resistance of the tiles were tested, and the results are also listed in Table 1.

(Margins below) Note ■) Manufactured by Sanyo Chemical Co., Ltd., 5K-500, in the above formula, R
,O”CH30,R,=COCH3,n=30,m=0 ■) Manufactured by Cabot Corporation, TS-720 ■) Manufactured by Maruo Calcium Co., Ltd., Sealets 300 ■) Manufactured by Chisso Corporation, S-510 ■) Based on the JIS A3548 standard test.G is mortar fracture, A is adhesive layer fracture, GA is interface fracture between mortar and adhesive layer, AB is interface fracture between adhesive layer and tile, G/A, GA/ A.

GA/G, AB/A, and AB/GA respectively. For example, G/A indicates a mixed state of G and A.

■)○: Viscosity change rate less than 20%, △: Viscosity change rate 20~
100% ■) According to JIS A3548 tile slip resistance test method. , Patent applicant Sunstar Giken Co., Ltd.

Claims (1)

[Claims] 1. A urethane prepolymer containing active isocyanate groups obtained by reacting a polyether polyol with an excess of a polyisocyanate compound, blended with a hygroscopic plasticizer, silica, and surface-treated calcium carbonate. A one-component urethane adhesive for tiles. 2. The hygroscopic plasticizer has the formula: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R_1O is a monohydric alcohol residue, and R_2 is an alkyl group having 1 to 8 carbon atoms or an alkyl group having 1 to 4 carbon atoms. The adhesive according to claim 1, which is a compound represented by a carbonyl group, n is 7 to 50, and m is 0 to 6. 3. The adhesive according to claim 1 or 2, which contains 1 to 15% by weight of a hygroscopic plasticizer, 1 to 10% by weight of silica, and 5 to 30% by weight of surface-treated calcium carbonate.