JP3342927B2 - Tile adhesive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tile adhesive applied to walls around buildings, bathrooms, toilets and kitchens. More specifically, in order to bond ceramic, porcelain, or stone tiles to an inorganic base such as cement mortar, silicate board, cement board, or a wood base such as plywood, at the time of on-site construction or at a factory. The present invention relates to an aqueous paste-like adhesive for tile used in forming a tile panel.

[0002]

2. Description of the Related Art Conventionally, tiles are bonded by so-called dumpling of cement mortar, but recently, in most cases, the bonding method has been changed to a bonding method using an adhesive. This tile adhesive is classified into an aqueous adhesive and a reactive adhesive, and is used depending on the application. The aqueous type is an acrylic emulsion, a styrene-butadiene latex as a base resin, a filler, a tackifying resin, an organic solvent, a plasticizer, a silane coupling agent, and the like are kneaded, and a one-part adhesive in a paste form is used. I have. On the other hand, the reactive type uses a one- or two-part adhesive based on a urethane resin or an epoxy resin and kneaded with various additives.

[0003]

Water-based adhesives have been dominant as tile adhesives for on-site construction because of their low risk of pollution and fire, low cost, and ease of use. However, it lacks water resistance, warm water resistance and the like, and thus is not suitable for uses around water, that is, for bathrooms, kitchens, and the like. In addition, the reactive type is used for both tile panels in the field construction and in the factory, and high adhesive strength, water resistance, hot water resistance, etc. can be obtained, but epoxy adhesives are usually amine-cured at room temperature. Two-part type with combined use of a system hardener, complicating compounding work, poor adhesion due to weighing errors, inability to store two-part formulations, expensive, risk of hardener odor and skin damage (fog), etc. For urethane adhesives, one-pack type is mainly used. However, when used under high temperature and high humidity, the pot life (time until tile bonding) is limited. There is a problem in handling that it is necessary to use up or to seal and store nitrogen gas or dry air, and it is not suitable especially for construction at a construction site, and there is also a problem of price. In recent years, there has been a demand for the development of a water-based emulsion type adhesive which has the adhesion performance of the reactive type adhesive.

[0004]

The inventors of the present invention have conducted various studies to solve the above-mentioned problems, and as a result, have found that an epoxy resin can be used together with an aromatic vinyl compound, an unsaturated carboxylic acid ester and a monomer having an amide group. After forming the polymerized emulsion particles, the outside thereof was subsequently copolymerized with an aromatic vinyl compound, an unsaturated carboxylic acid ester and a monomer having a carboxyl group, a hydroxyl group, and an amide group,
An epoxy-modified acrylic emulsion having a so-called core-shell structure has been found to be extremely effective in adhesion, water resistance, warm water resistance, etc., without a change in viscosity during long-term storage. By blending two or more different fillers, the storage stability,
Without impairing the adhesive performance, found that it is possible to obtain an inexpensive tile adhesive, which has a high viscosity and a high thixotropic viscosity, does not cause displacement even when the adhesive is applied to the vertical surface and the tiles are attached, The present invention has been completed.

That is, the present invention is as follows. 1. The core layer is a copolymer of an aromatic vinyl monomer, an unsaturated carboxylic acid ester monomer, a monomer containing an amide group and an epoxy resin, and the shell layer is formed of an aromatic vinyl monomer, an unsaturated carboxylic acid ester monomer, and a carboxyl group. One-part curable aqueous solution in which an epoxy-modified acrylic emulsion (a) having a core-shell structure, which is a copolymer of a monomer having a hydroxyl group and a monomer having an amide group, is preliminarily blended with a curing agent (b) for an epoxy resin. An adhesive for tiles comprising two or more fillers having different particle sizes mixed with an emulsion. 2. The epoxy-modified acrylic emulsion (a) is characterized in that 5 to 50 parts by weight of an epoxy resin is copolymerized in 100 parts by weight of the solid content of the emulsion. The adhesive for a tile according to the above. 3. The glass transition temperature (Tg) of the epoxy-modified acrylic emulsion (a) is -20 to + 30 ° C. The adhesive for a tile according to the above. 4. The glass transition temperature (Tg) of the core layer of the epoxy-modified acrylic emulsion (a) is -10 to + 60 ° C, and the glass transition temperature (Tg) of the shell layer is -40 to + 10 ° C. The adhesive for a tile according to the above. 5. A one-part curable aqueous emulsion in which a curing agent (b) for an epoxy resin (b) is blended in an amount of 5 to 25 parts by weight as a solid content with respect to 100 parts by weight of a solid content of the epoxy-modified acrylic emulsion (a). . The adhesive for a tile according to the above. 6. The composition is characterized in that 30 to 150 parts by weight of a filler is blended with respect to 100 parts by weight of the solid content of the epoxy-modified acrylic emulsion (a). The adhesive for a tile according to the above.

The epoxy-modified acrylic emulsion (a) having a core-shell structure of the present invention (hereinafter abbreviated as EPAE) is prepared by first preparing a mixed monomer obtained by dissolving an epoxy resin in various monomers used for a core layer. It is gradually added to the activator-containing distilled water with stirring at room temperature to prepare a so-called pre-emulsified monomer. Next, distilled water and a surfactant were charged into a flask equipped with a stirrer and a condenser, and the flask was purged with nitrogen, heated to 70 ° C., a polymerization initiator was administered, and the pre-emulsified monomer was added dropwise over a certain period of time. At the same temperature, the remaining monomers are allowed to react to form emulsion particles serving as the core of the present invention. Subsequently, various monomers used in the shell layer in advance as emulsified monomers in the same manner as in the core layer were dropped into the flask over a certain period of time, and the remaining monomers were allowed to react in the same manner as described above. EPAE having a so-called core-shell structure coated with particles is obtained. After completion of the reaction, the mixture is cooled to 40 ° C. or lower, and adjusted to a pH of 6 to 9 with ammonia water.
The EPAE used in the present invention is obtained by filtration through a 100 mesh wire mesh.

The monomers used in the emulsion polymerization of EPAE of the present invention include styrene and α-methylstyrene as aromatic vinyl monomers, and methyl methacrylate, ethyl methacrylate, isobutyl methacrylate and tert as unsaturated carboxylic acid esters. Acrylic acid or methacrylic acid ester having an alkyl group having 4 to 12 carbon atoms such as butyl methacrylate, vinyl acetate, acrylonitrile, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, 2 ethyl hexyl acrylate, 2 ethyl hexyl methacrylate, and lauryl methacrylate Of these, styrene and n-butyl acrylate are preferred from the viewpoint of economy and ease of emulsion polymerization. As monomers having an amide group, acrylamide, methacrylamide, maleimide,
Examples thereof include N-methylolacrylamide and N-methylol methacrylamide. Among them, methacrylamide or N-methylol methacrylamide is preferable from the viewpoint of water resistance, warm water resistance and boiling resistance. Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid and the like.Among them, acrylic acid or methacrylic acid is preferable from the viewpoint of stability during emulsion polymerization, mechanical and chemical stability. preferable. Examples of the monomer having a hydroxyl group include hydroxyethyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl acrylate, and among them, hydroxyethyl methacrylate is preferred from the viewpoint of stability after blending a curing agent for an epoxy resin.

As epoxy resins, bis-epi type comprising bisphenol A type and epichlorohydrin, cyclic fatty acid type comprising cyclic fatty acid unsaturated compound and peracetic acid, novolak type comprising phenol resin and epichlorohydrin,
Tetraepoxy type composed of glyoxal and phenol and epichlorohydrin, polybutadiene type composed of polybutadiene and peracetic acid, halogenated type composed of halogenated bisphenol A and epichlorohydrin, side chain type composed of bisphenol A and epichlorohydrin and propylene oxide, and other polyalkylene ether types , Ester type, methyl-substituted type and the like. Among these, bisphenol A-
An epichlorohydrin type resin is suitable, and for example, an epoxy resin having an epoxy equivalent of 180 to 270 and a viscosity of 5 to 150 poise is preferable.

The copolymerization ratio of the epoxy resin to 100 parts by weight of the solid content of EPAE is in the range of 5 to 50 parts by weight. That is, it means that the epoxy resin is used for the emulsion core layer. Preferably it is in the range of 10 to 30 parts by weight. If the amount is less than 5 parts by weight, the water resistance, warm water resistance, heat resistance, etc. will be inadequate. If the amount is more than 50 parts by weight, the stability will not be obtained during the emulsion polymerization of the core layer, causing a production problem. The glass transition temperature (Tg) (hereinafter abbreviated as Tg) of the EPAE of the present invention is in the range of −20 to + 30 ° C. More preferably, it is in the range of -5 to 5C. -20 ° C
If it is lower, the adhesive strength, boiling resistance and heat resistance will decrease,
When the temperature is higher than + 30 ° C., the emulsion film is not formed uniformly at a low temperature. Incidentally, Tg expressed in the present invention means a value calculated from all monomers excluding the epoxy resin. Tg of the core layer of EPAE of the present invention is-
The range is from 10 to +60, preferably from 0 to 50 ° C. When the temperature is lower than -10 ° C, hot water resistance and heat resistance cannot be obtained, and when the temperature is higher than + 60 ° C, the adhesive strength decreases. Similarly, the Tg of the shell layer is −40 to + 10 ° C.
And more preferably in the range of -30 to + 5 ° C. When the temperature is lower than -40 ° C, the adhesive strength, hot water resistance and heat resistance cannot be obtained, and when the temperature is higher than + 10 ° C, the emulsion film is not formed uniformly at a low temperature, which poses a practical problem.
The weight ratio of the monomers used in the core layer and the shell layer of EPAE is not particularly limited, but the preferred core-shell composition ratio is in the range of 7/3 to 3/7.

Examples of the curing agent (b) for an epoxy resin include aromatic amines, aliphatic amines, heterocyclic modified amines, amines such as polyamides, polysulfides, and acid anhydrides. Among these, although not particularly limited, those which can be freely diluted with water or those which can be converted into an aqueous emulsion are preferable in view of mixing with an aqueous emulsion. The mixing ratio of the epoxy resin curing agent is in the range of 5 to 25 parts by weight as a solid content with respect to 100 parts by weight of the solid content of EPAE. It is more preferably in the range of 7 to 15 parts by weight. If the amount is less than 5 parts by weight, a sufficient cured product of the adhesive cannot be obtained, and the adhesive strength, water resistance, hot water resistance, heat resistance, and the like are lacking. In addition, problems such as yellowing, decrease in solid content, etc. occur, and an excessive epoxy curing agent exhibits a plasticizing effect and causes a decrease in adhesive strength.

The fillers include light calcium carbonate, heavy calcium carbonate (including surface-treated products), silica, talc, clay, titanium white, carbon, asbestos, glass powder, aluminum powder, mica, shirasu balloon, cold water and the like. Inorganic fillers having an average particle size of 0.2 to 300 microns, fibrous fillers of short fiber or long fiber pulp, plastic powders such as polyester, styrene, acryl and the like, among which economical efficiency and high viscosity And has high thixotropic properties, easy to apply with a comb iron, preventing dripping of the adhesive on the vertical surface and displacement of the tiles, combined use of two or more heavy calcium carbonates with greatly different particle diameters, Further, it is preferable to use a silica-based thixotropic agent for acicular crystals in combination. In the present invention, the amount of the filler is EPA of the present invention.
E and 100 parts by weight of the solid content of the one-part curable aqueous emulsion obtained by blending the epoxy curing agent with 3 parts.
It is in the range of 0 to 150 parts by weight, more preferably 50 to 100 parts by weight. If the amount is less than 30 parts by weight, a high-viscosity and high-thixotropic property of the adhesive cannot be obtained. If the adhesive is applied to a wall or the like on a vertical surface, a problem occurs that the adhesive drips, and the tile is displaced. When the amount is less than 150 parts by weight, the viscosity is too high, which hinders the coating operation and lowers the adhesive strength.

As described above, the one-part curable aqueous emulsion obtained by blending the EPAE with the curing agent for epoxy resin of the present invention and the tile adhesive comprising the filler react with glycidyl groups in the emulsion particles. Despite the coexistence of a carboxyl group and a curing agent for an epoxy resin, the glycidyl group is a particle in a shape protected by a shell layer. When adhesives are applied and tiles are bonded, they have the properties of an aqueous emulsion type adhesive and have adhesive strength, alkali water resistance, hot water resistance, heat resistance, etc. comparable to epoxy adhesives. The practical value as an agent is extremely high. The present adhesive is a dispersant, an antifoaming agent, water, a tackifying resin, an organic solvent, a plasticizer, a coloring agent, an organic thickener, an antifreezing agent, as long as the desired effect is not impaired.
A pH adjuster, a silane coupling agent, or the like may be used.

[0013]

EXAMPLES The present invention will be described below with reference to Production Examples, Examples and Comparative Examples, but is not limited thereto.
In the examples, parts and percentages are by weight unless otherwise specified.

Preparation Examples 1 to 9 A mixture of 100 parts of the mixed monomer for the core and shell layers having the composition ratios shown in Table 1 and a chain transfer agent were weighed in advance, and 50 parts of distilled water and sodium dodecylbenzenesulfonate were respectively measured. It was added dropwise to 0.5 part under stirring conditions to obtain a pre-emulsified monomer. Separately, 100 parts of distilled water and 0.2 parts of sodium dodecylbenzenesulfonate were charged into a 1-liter flask, and heated to 70 ° C. while stirring under a nitrogen seal, and then 0.5 parts of potassium persulfate and an emulsion seed were added. To this end, 0.5 part of a mixed monomer having a ratio of 1: 1: 1 of n-butyl acrylate, methyl methacrylate and hydroxyethyl methacrylate was charged and reacted for 20 minutes to form an emulsion core. Next, the pre-emulsifying monomer for the core was continuously dropped over 3 hours, and the remaining monomer was reacted for 2 hours after completion of the dropping. Subsequently, the emulsifying monomer for shell was similarly added dropwise over 3 hours, and the remaining monomer reaction was carried out at the same temperature for 3 hours.
The mixture was adjusted to H7, and a curing agent for an epoxy resin shown in Table 1 was blended. The mixture was filtered through a 100-mesh wire gauze to obtain a one-part curable aqueous emulsion having a solid content of 50% used in the present invention.

[0015]

[Table 1]

Examples 1 to 1 One-part curable aqueous emulsions 100 obtained in Production Examples 1 to 9
0.5 part of a 5% aqueous solution of sodium tripolyphosphate in
10 parts of distilled water and 0.05 parts of defoamer (San Nopco Co., Ltd.)
(Trade name, Nopco 8034L) was collected in a polyethylene cup and mixed with a homogenizer with stirring. Subsequently, the fillers shown in Table 2 were gradually added under stirring, and after uniform kneading, other additives were subsequently blended in the order shown in the table to obtain the tile adhesive of the present invention. This adhesive was applied to a JIS mortar plate in a bead shape using a comb-like iron in a bead shape at an amount of 350 g / m 2, left at room temperature for 20 minutes, and cut into 4 cm square ceramic tiles (manufactured by INAX Corporation, trade name). Ribeina SP-100 was cut with a special cutter.) After curing for 7 days at room temperature, the adhesion was measured by the following method, which was slightly modified according to the test method of JIS-A5548 (adhesive for ceramic tiles). The evaluation results are shown in Table-3.

1) Storage Stability of Adhesive 500 g of the adhesive was sampled and sealed in a 500 cc polyethylene bottle, and the viscosity change after standing at 40 ° C. for 30 days was measured using a BM-type rotational viscometer and indicated as follows. -The change in viscosity is 10% or less as compared with the initial viscosity. △ Viscosity change of about 50% compared to the initial viscosity is observed. × Viscosity change or aggregation of 100% or more compared to the initial viscosity is observed. 2) Displacement of tile on vertical surface An adhesive of 350 g / m2 is applied to the plate by the above-mentioned method, and the plate is set upright. The original plate of SP-100 was attached, and the displacement length of the tile after 10 minutes was measured and indicated in mm. 3) Adhesive force test An instron tensile test jig was attached to the front and back surfaces of the sample (mortar and tile surfaces), and the adhesive force in the plane tensile direction was measured at a pulling speed of 3 mm / min, and expressed in Kg / square centimeter. ) Standard adhesive strength: adhesive strength after curing at room temperature for 7 days b) Warm water resistance: adhesive strength after immersing the cured product in warm water at 50 ° C for 24 hours and then cooling it at room temperature for 1 hour c) Repeating drying and immersing in water: Adhesion after dipping in water at 20 ° C. for 4 hours, drying in a drier at 60 ° C. for 20 hours for 4 cycles, and cooling at room temperature for 1 hour d) Dipping in alkaline water: dipping in calcium hydroxide saturated aqueous solution at 20 ° C. for 48 hours E) Heat resistance: adhesive strength after leaving in a dryer at 60 ° C. for 672 hours and then cooling at room temperature for 1 hour

Comparative Example 1 An EPAE was prepared using a mixture of the core and shell monomers used in Production Example 1 in accordance with the same emulsion polymerization method as in the core layer of Production Example 1. A mixture containing a curing agent for an epoxy resin was used in the same manner as in Example 1, and the procedure was performed in the same manner as in Example 1 except that calcium carbonate was used as one type. The evaluation results are shown in Table 3.

Comparative Example 2 In place of the one-part curable aqueous emulsion of Example 1, a styrene-butadiene copolymer latex (trade name: Structbond 1341, manufactured by Mitsui Toatsu Chemicals, Inc., solid content: 4)
8%, viscosity 100 cps, PH7, acrylic acid-modified type) 100 parts of epoxy resin emulsion, 100 parts of epoxy resin emulsion (manufactured by Kanebo NSC Co., Ltd., trade name Eporsion EA-3,
Solid content 50%, viscosity 100cps, epoxy equivalent 900)
And a 10% 45% emulsion of a modified aliphatic amine (manufactured by Kanebo NSC Co., Ltd., trade name: Eporsion EB-1). The evaluation was carried out in the same manner as in Example 1, and the evaluation results are shown in Table-3. Was.

Comparative Example 3 In place of the one-part curable aqueous emulsion used in Example 1, an acrylic emulsion (trade name: Almatex E-175, manufactured by Mitsui Toatsu Chemicals, Inc., solid content: 45%, PH)
8, viscosity 1000 cps, Tg-10 ° C., methacrylic acid and acrylamide modified type), and the same procedure as in Example 1 was carried out except that the silica-based filler was omitted. The results are shown in Table 3.

Comparative Example 4 Two-part epoxy adhesive (manufactured by Mitsui Toatsu Chemicals, Inc.)
Adhesion was carried out in the same manner as in Example 1 using a trade name of Structbond E71, the main agent being a bisphenol A type epoxy resin, and the curing agent being an inorganic filler compound containing a modified polyamide as a main component. Indicated.

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

As is clear from the evaluation results in Table 3,
Based on the one-part curable aqueous emulsion obtained by blending the EPAE of the present invention and a curing agent for epoxy resin,
Adhesives containing fillers have excellent storage stability at high temperatures. Even though they are water-based emulsion adhesives, they should have the adhesive strength, water resistance, hot water resistance, alkali resistance, heat resistance, etc. that tile adhesives should have. The practical value of the adhesive for tiles is great because of its performance.

Continuation of front page (56) References JP-A-58-152074 (JP, A) JP-A-56-118473 (JP, A) JP-A-58-69272 (JP, A) JP-A-60-217278 (JP, A) JP-A-60-84372 (JP, A) JP-A-61-183373 (JP, A) JP-A-51-24636 (JP, A) JP-A-6-192641 (JP, A) 57-119945 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09J 151/08 C08G 59/34 C09J 163/00

Claims (6)

(57) [Claims] The core layer is a copolymer of an aromatic vinyl monomer, an unsaturated carboxylic acid ester monomer, an amide group-containing monomer and an epoxy resin, and the shell layer is an aromatic vinyl monomer, an unsaturated carboxylic acid ester. A curing agent (b) for an epoxy resin was previously blended with an epoxy-modified acrylic emulsion (a) having a core-shell structure, which is a copolymer of a monomer, a monomer having a carboxyl group, a monomer having a hydroxyl group, and a monomer having an amide group. An adhesive for tiles obtained by mixing two or more kinds of fillers having different particle diameters with a one-part curable aqueous emulsion. 2. An epoxy-modified acrylic emulsion (a)
The adhesive for tiles according to claim 1, wherein 5 to 50 parts by weight of an epoxy resin is copolymerized in 100 parts by weight of the solid content of the emulsion. 3. An epoxy-modified acrylic emulsion (a)
The adhesive for tiles according to claim 1, wherein the glass transition temperature (Tg) of the adhesive is -20 to + 30 ° C. 4. An epoxy-modified acrylic emulsion (a)
Has a glass transition temperature (Tg) of -10 to +60.
° C, the glass transition temperature (Tg) of the shell layer is -40 to +1
The adhesive for tiles according to claim 1, wherein the temperature is 0 ° C. 5. An epoxy-modified acrylic emulsion (a)
The adhesive for tiles according to claim 1, wherein the one-part curable aqueous emulsion is prepared by blending 5 to 25 parts by weight of a curing agent (b) for epoxy resin as a solid content with respect to 100 parts by weight of the solid content of the above. Agent. 6. An epoxy-modified acrylic emulsion (a)
The adhesive for tiles according to claim 1, wherein 30 to 150 parts by weight of a filler is blended with respect to 100 parts by weight of the solid content of the tile.