JPS6213662A - Repairing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] ['Industrial application field] The present invention relates to a method for repairing cement tiles and factory floors.

[Prior art and its problems]

The surface of the cement tile is undercoated with urethane paint containing cement or acrylic urethane paint, and this surface is then overcoated with this paint to create a painted cement tile or a floor formed by curing epoxy resin containing silica sand. Factory floors coated with paint are known. The top coat layer of these paints is applied to waterproof cement tiles and floors (
4? 1983-73231, 55-5°1782, 50-67832, Special Publication No. 52-48618)
.

When the surface coating layer of these painted memento tiles and factory floors is damaged, it is necessary to repair the rounding to make the house and floor last longer.

Conventionally, for this repair, an aqueous resin dispersion such as a styrene acrylic acid lower alkyl ester copolymer, a vinyl acetate/acrylic acid lower alkyl ester copolymer, etc., or an aqueous resin dispersion such as ordinary Portland cement, silica sand, etc. A resin mortar mixed with fine aggregate is applied to the damaged area, dried, and, if necessary, top coated with the aqueous resin dispersion for repair.

However, the aqueous resin dispersion or resin mortar for repairing damaged parts has weak adhesion to tiles and factory floor bases, and has the disadvantage that the period from repair to next repair is short. Furthermore, when the base coat film is a urethane resin film, it is not possible to obtain a repair film with practical adhesive strength using the resin aqueous dispersion or resin mortar, and it is necessary to place the damaged painted cement tile on a new painted cement tile. The reality is that it is changing.

In order to ensure the repair, an acrylic urethane resin layer is used for the top coat layer of painted cement tiles and factory floors, and as a repair liquid, cationic SBR latex, which is highly compatible with cement, is used, as well as ordinary Portland cement and fine aggregate. It was proposed to use a compounded resin mortar.

This resin mortar provides a coating film with excellent adhesive strength to urethane resin coatings, but this is only possible in seasons with small temperature differences such as spring and autumn, and only in seasons with large temperature differences such as summer and winter. It cannot be said that it is practical enough to use it seasonally.

[Specific measures to solve the problem]

The present invention uses an aqueous resin dispersion containing a hydrazine derivative in an aqueous dispersion of an acrylic copolymer containing a carbonyl group as a repair solution for tiles, floors, etc., thereby achieving adhesion to tiles and floors without being affected by temperature. The present invention provides a repair method that provides a coating film with good properties.

[Structure of the invention]

The present invention is a urethane resin for painters, factory floors, decorative walls, etc.
By applying an aqueous dispersion of room-temperature crosslinking acrylic resin containing the following components (4) and (b) to the top coat resin layer selected from acrylic resin and epoxy resin, and drying. The present invention provides a repair method characterized by forming a coating film of crosslinked resin.

(2) Acrylic copolymer containing carbonyl group (0, hydrazine derivative containing at least two hydrazine residues.

(Adherent material) The adherend material to which the repair solution is applied unevenly is painted cement tiles that have a top coat layer of urethane resin (including acrylic and urethane resin), acrylic resin, and epoxy resin. , factory floors, and decorative walls.

(Repair Liquid) The repair liquid is made of an aqueous dispersion of room-temperature crosslinkable acrylic resin containing the following (4) and (9) components.

(4), acrylic copolymer with carbonyl group■,
A hydrazine derivative having at least two hydrazine residues.

Up to 70% by weight or less of the above-mentioned component of this repair liquid is a non-crosslinkable resin aqueous dispersion, such as n-butyl acrylate copolymer, vinyl acetate-ethyl acrylate copolymer, vinyl chloride/acrylic acid copolymer. It may be replaced with an aqueous emulsion such as a coalescence.

The resin aqueous dispersion consisting of the above components
No. 4-110248, No. 57-3850, No. 58-9
Written in Publication No. 6643 Ji! has been done.

Specifically, the aqueous emulsion of the carbonyl group-containing acrylic copolymer as component (1) contains (a) methyl methacrylate, a vinyl aromatic compound, tert-butyl acrylate,
Monomer 10 selected from vinyl halide and ethylene
~75% by weight, 伽) 25-90% by weight of monomers selected from acrylic or methacrylic esters of alcohols having 2-16 carbon atoms, methyl acrylate, vinyl esters and 1,3-dienes. %, (C) carbonyl group-containing monomer having at least one aldo group or keto group and one polymerizable double bond in the molecule 0.1 to
20% by weight, and (Φ unsaturated carboxylic acid monomer O~1
It can be obtained by emulsion polymerization of monomers containing 0% by weight (see the aforementioned publications).

Examples of the monomer (a) include methyl methacrylate, vinyl aromatic compounds (such as styrene), tert-butyl acrylate, vinyl halides (such as vinyl chloride,
A monomer selected from vinylidene chloride (vinylidene chloride, etc.) and ethylene is used, and the copolymerization ratio of monomer (a) in emulsion polymerization is usually 10 to 75% by weight, preferably 30% by weight, based on the total monomers. ~70% by weight. Two or more types of monomers (a) can be used in combination. Monomer (a) acts to impart hardness to the coating film of the composition of the present invention.

Monomers Cb) include acrylic or methacrylic esters of alcohols having 2 to 16 carbon atoms, methyl acrylate, vinyl esters (e.g. vinyl acetate, vinyl propionate, etc.), and 1,3-dienes. The copolymerization ratio of monomer (b) in emulsion polymerization is usually 25 to 90% by weight, preferably 30% by weight based on the total monomers.
~70% by weight. It is also possible to use two or more monomers (b) in combination. The monomer (among monomers) acts to impart flexibility to the coating film.

As the monomer (c), a carbonyl group-containing monomer having at least one aldo group or keto group and one polymerizable double bond in the molecule is used.

Note that ester bonds (-C-0-) and carboxyl groups (
Compounds having only -C-OH) are not included in this monomer (e). Specific examples of monomer (c) include acrolein, diacetone acrylamide, formylstyrene, vinyl alkyl ketones having 4 to 7 carbon atoms (e.g. vinyl methyl ketone, vinyl ethyl ketone,
vinyl butyl ketone, etc.) General formula (wherein, R1 is H or C, R2 is H or an alkyl group having 1 to 3 carbon atoms, R3 is an alkyl group having 1 to 3 carbon atoms, W is 1 acrylic (representing each alkyl group having ~4 carbon atoms)
or methacrylic)oxyalkylpropanal, diacetone acrylate, diacetone methacrylate, acetonitrile acrylate, 2-hydroxypropyl acrylate-acetylacetate, butanediol-1,4
-Acrylate-acetylacetate etc.=
Particularly preferred are diacetone acrylamide, acrolein and vinyl methyl ketone.

The copolymerization ratio of monomer (e) in emulsion polymerization is usually 0.1 to 20% by weight, preferably 1 to 7% by weight based on the total monomers.
Weight%. Monomer (e) acts to provide a carbonyl group (that is, an aldo group or a keto group) to the carbonyl group-containing copolymer, and the carbonyl group reacts with the organic hydrazine derivative to form a crosslinked structure. This contributes to improving the physical properties of the coating film, particularly the water resistance, chemical resistance, blocking resistance, etc. of the coating film.

Examples of the monomer (d) include unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, and citraconic acid;
Examples include acrylamide, methacrylamide, and N-methylolmethacrylamide.
d) is itaconic acid, or itaconic acid and acrylic acid, itaconic acid and methacrylic acid, or itaconic acid, acrylic acid, and methacrylic acid. The copolymerization ratio of monomer (d) is usually 0
-10% by weight, preferably 0.5-5.0% by weight, more preferably 0.8-2.5% by weight.

In order to obtain a room-temperature crosslinkable carbonyl group-containing copolymer dispersion of the (oral) component, at least the above (a) to (d)
In addition to these monomers (a) to (d), other monomers may be copolymerized in the emulsion polymerization. is possible. Other monomers that can be copolymerized include, for example, butanediol diacrylate, butanediol monoacrylate, acrylonitrile, methacrylonitrile, various unsaturated acid amides, N-alkyl of unsaturated acid amides, and/or Examples include N-alkylol derivatives (eg, acrylamide, N-methylacrylamide, N-imbutylacrylamide, N-methylol acrylamide, N-methylol methacrylamide, etc.).

The emulsion polymerization itself for obtaining the aqueous dispersion of the carboxyl group-containing copolymer as the carrier component is well known to those skilled in the art. Examples of emulsifiers used in the emulsion polymerization include alkyl, rusulfate, alkylbenzene sulfonate, polyoxyethylene alkyl sulfate, polyoxyethylene alkylphenol ether/I/? Anionic surfactants such as rufeate, polyoxyethylene alkylny? Examples include nonionic surfactants such as polyoxyethylene alkylphenol ether, ethylene oxide propylene oxide block copolymer, and sorbitan derivatives. As described below, particularly preferred emulsifiers are alkyl sulfates, alkyl sulfonates, alkylbenzene sulfonates, or combinations of these surfactants with polyoxyethylene alkylphenol ether sulfate.

In addition, as a polymerization initiator in emulsion polymerization, for example, persulfates such as potassium persulfate and ammonium persulfate,
Examples include hydrogen peroxide, organic peroxides such as benzoyl peroxide, cumene hydroperoxide, and tertiary butyl hydroperoxide, and azobisin butyronitrile. Particularly preferred are water-soluble initiators and resox-type initiators.

Next, examples of organic hydrazine derivatives having at least two hydrazine groups include, for example, 2 to 10 hydrazine groups, particularly 4 to 10 hydrazine groups.
Mention may be made of dihydrazides of dicarboxylic acids containing 6 carbon atoms. Namely, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide, and isophthalic acid dihydrazide. Also, aliphatic water-soluble dihydrazines having 2 to 4 carbon atoms, and evaporated ethylene-
Examples include 1,2--)hydrazine, propylene-1,3-dihydrazine, and butylene-1,4-dihydrazine. Particularly preferred organic hydrazine derivatives are adipic acid dihydrazide, inphthalic acid dihydrazide, and sebacic acid dihydrazide.

In the organic hydrazine derivative of the component (2), when the solvent (for example, water) is volatilized to form a coating film, the carbonyl group of the ω component and the hydrazine group of the component (4) form a hydrogen bond to form a crosslinked polymer.

It is assumed that the formation of this crosslinked polymer is a factor in improving the heat resistance and tensile strength of the resulting coating film.

In the above hydration reaction, the organic hydrazine derivative of component
The amount to be added is determined taking into consideration that it will be consumed at a rate of 1 mole. (2) If the amount of the component is small, the effect of improving the adhesive strength to the adherend and the strength of the coating film will be small.

- This emulsion of an acrylic copolymer containing a carbonyl group as the component (■), and a room-temperature crosslinking type emulsion containing an organic hydrazine derivative as the component (■), are Acronal YJ-2715D% YJ-272 from Yuka Verdice ■.
It is sold under the product names 0D and YJ-2740D.

This repair solution contains zinc sulfate, manganese sulfate, water-soluble acetates and nitrates of zinc, manganese, cobalt or lead.
A small amount of curing accelerator such as zinc nitrite and lead nitrite can be blended.

When using this repair solution as a repair solution for painted cement tiles, add 50 to 1,000 parts by weight of Portland cement and 50 to 2 parts by weight of fine aggregate such as silica sand to 100 parts by weight of the solid resin content of the resin emulsion. It is preferable to mix 0.000 parts by weight in terms of improving the adhesion to painted cement roof tiles, drying the repair solution, and making the coating material thicker. Instead of the above Portland cement, white cement, early strength cement, ultra early strength cement, etc., and blast furnace cement called mixed cement,
Silica cement, fly ash cement, etc. can also be used.

This repair solution further contains pigments; extender pigments such as calcium carbonate, talc, clay, mica powder, and pallite; potassium, sodium, or ammonium salts of condensed phosphoric acid such as hexametaphosphoric acid; sodium or ammonium salts of polyacrylic acid. ; Usual anionic or nonionic specific surfactants; Dispersants such as methylcellulose, ethylcellulose, flobylcellulose, carboxymethylcellulose, polyvinyl alcohol; Various components such as plasticizers and thickeners, petroleum resins, rosin, and terpenes - Adhesives such as phenol copolymers can be blended.

The application of the repair liquid to the unevenly placed adherend material is performed using a brush, trowel, spray, roll, or the like.

If necessary, an acrylic resin topcoat or a urethane resin topcoat is applied onto the coating film formed by the repair solution to form a top coat layer with good gloss.

(Effects) The crosslinked coating film formed by the repair liquid used in the present invention has excellent adhesion not only to urethane resins, acrylic resins, and epoxy resins, but also to cement products, and since it is crosslinked, it has low tensile strength and creep. It has the advantage that its performance is not affected by temperature or temperature.

Hereinafter, the present invention will be further explained in detail by giving Examples and Comparative Examples. Parts and percentages in these examples are by weight unless otherwise specified.

Production of acrylic copolymer aqueous emulsion Example 1 Temperature controller, anchor stirrer, reflux condenser, supply container,
The following materials were charged into a reaction vessel equipped with a thermometer and a nitrogen inlet tube.

200 parts of water 10 parts of a 35% aqueous solution of the sodium salt of the sulfuric acid half-ester of p-phenylphenol (anionic emulsifier) reacted with 20 moles of ethylene oxide 1.5 parts of the sodium alkyl sulfate salt Separately, as feed I, a mixture of: prepared.

water 200
Parts 35% aqueous solution of the above anionic emulsifier 20 parts Styrene 150 parts Acrylic acid
2-ethylhexyl ester 17 G'l methyl methacrylate 140 parts diacetone diacrylamide 20 parts acrylic acid
10 parts acrylamide 10
Furthermore, a solution of 2.5 parts of potassium persulfate dissolved in 85 parts of water was prepared as feed (2).

After purging the inside of the reaction vessel containing the above-mentioned charges with nitrogen gas, 10% of feed (2) was added and heated to 90°C, and then 10% of feed (2) was injected.

While heating and stirring at 90°C, feed (1) and the remainder of feed (2) were uniformly fed into the reactor little by little over a period of 3 to 3.5 hours. After the supply was completed, the reaction was continued at 90° C. for another 1.5 hours with stirring, and then the inside of the reactor was cooled to room temperature.

Add ammonia water to the resulting dispersion to adjust the pH to 7-8.
An aqueous dispersion of the copolymer having a solid content of 50% was obtained.

Examples 2 to 4 An aqueous dispersion of an acrylic copolymer was obtained in the same manner as in Example 1, except that the component ratio of the vinyl monomer was changed as shown in Table 1.

(Margin below) Table 1 Examples 1-6, Comparative Examples 1-3 ° A repair solution with the composition shown in Table 2 was prepared.

Apply this repair solution so that a coating film with a thickness of 2 m is obtained on the detonation plate, which has a top coat layer of (a), urethane resin film (b), epoxy resin film (C), and acrylic resin film. After curing and drying at 20°C for 7 days, the following accelerated durability test was carried out, and after drying at 20°C for 48 hours, the adhesive strength of the coating film was determined according to the method of JIS A-6910.

The results are shown in Table 2.

1) After standard curing: Measure immediately after curing at 20°C for 7 days.

2) After immersion in water: After immersing the sample in water for 10 days.

3) @After water test = One cycle consists of soaking the sample in warm water at 60°C for 2 hours, taking it out, and drying it at 80°C for 1 hour, and repeating this cycle 10 times.

4) After cold cycle: After immersing in water at 20°C for 16 hours, freezing at -20°C, holding for 4 hours, and then drying at 80°C for 4 hours, one cycle was repeated 10 times.

(Margin below)

Claims (1)

[Claims] 1) The following component (A) and (B) are applied to the surface of a resin layer selected from urethane resin, acrylic resin, and epoxy resin.
A repair method (A) characterized by forming a coating film of a crosslinked resin by applying an aqueous dispersion of a crosslinkable acrylic resin at room temperature and drying the resin, an acrylic copolymer containing a carbonyl group. (B) A hydrazine derivative having at least two hydrazine residues. 2) The repair method according to claim 1, wherein component (B) is blended in a proportion of 0.02 to 1 mole per mole of carbonyl group of component (A).