JP2590006B2 - Paint film waterproofing composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Object of the Invention [Industrial Application Field] The present invention relates to a composition used for coating film-preventing water using a resin emulsion, especially for a reactive coating film waterproofing, It can be widely used in the field.

[Conventional technology]

It is necessary to apply an appropriate waterproofing treatment to prevent water permeation on the roof, walls, and other surfaces of the structure. Conventional waterproofing methods include (a) sheet waterproofing, (b)
Asphalt waterproofing, (c) mortar waterproofing, (d) coating film waterproofing, and the like.

Among the waterproofing methods described above, the sheet waterproofing method (a) is difficult to apply to a small area, a complicated and complicated place and an elevation, and a seamless waterproof layer cannot be obtained. There is a drawback that many accidents are caused by this. The asphalt waterproofing of (b) requires construction under heating, and there are problems in terms of work danger, odor problem and equipment cost. Further, the obtained coating film is apt to be deformed or deteriorated at a high temperature, and is not satisfactory. The mortar waterproofing of (c) has a drawback that the coating film has no flexibility, cannot follow the deformation or crack of the base, and the film is easily damaged.
The coating waterproofing of (d) includes a type using a solvent type resin such as polyurethane and epoxy resin, and a type using an emulsion or synthetic rubber latex such as acrylic resin and ethylene-vinyl acetate copolymer resin. When a solvent-type resin such as an epoxy resin is used as a coating film forming material, a coating film having good adhesion cannot be directly formed on a wet surface,
There is a difficulty in handling if it is difficult to make a thick coating on the upright surface and if the desired coating film performance cannot be obtained unless the compounding of the curing agent is taken into account.

On the other hand, emulsions and the like used as coating film forming materials include acrylic emulsions, vinyl acetate emulsions, ethylene-vinyl acetate emulsions, synthetic rubber latex, and the like. It has disadvantages, ethylene-
Vinyl acetate emulsions substantially improve the disadvantages of vinyl acetate emulsions, but are inferior to acrylic emulsions in terms of weather resistance and water resistance. Synthetic rubber latex such as styrene butadiene latex or chloroprene latex also has drawbacks in terms of weather resistance and abrasion resistance. Unlike these emulsions, acrylic emulsions can be said to exhibit the best performance as an emulsion used in a waterproofing composition in combination with excellent weather resistance. However, in any case, the conventional emulsion-type waterproof coating film has a disadvantage that the film formation is slow and the working conditions are greatly restricted such as being easily washed away by rainwater or the like. As a method for improving this, there is a method in which cement is used in combination, but at present, an emulsion exhibiting excellent properties when used in combination with cement has not yet been found. That is, when an anionic emulsion is used, the hardening of a hydraulic substance such as cement is easily inhibited by the anionic surfactant, and it takes a long time to form a coating film, resulting in poor workability. Also,
When the amount of the nonionic surfactant is small, the stability of the emulsion is poor, and when the amount is large, it takes a long time to form a coating film, and the formed coating film has poor water resistance. Cationic emulsions are said to be excellent as emulsions for cement admixture, but have the disadvantage of poor stability and gelling in a short time when mixed with an inorganic hydraulic substance.

[Problems to be solved by the invention]

The present inventors have conducted various studies with the object of finding a composition that can solve the above-mentioned problems in a cement combination method used as a means for improving the film formability of an emulsion type coating film waterproofing material. .

(B) Configuration of the Invention [Means and Actions for Solving the Problems] The present inventors emulsify a polymer having a specific amount of a specific monomer as a component and a glass transition point of -20 ° C or lower. Composition comprising an inorganic hydraulic substance such as a cationic or nonionic emulsion and cement dispersed therein has excellent properties, that is, the stability of the emulsion when used in combination with an inorganic hydraulic substance and an aggregate. A composition that exhibits extremely fast film formation without hindrance, and that the resulting film has excellent weather resistance, strength, flexibility, water resistance, etc., and that it sufficiently follows the deformation of the skeleton. The present invention has been completed by finding that the following can be achieved.

That is, the present invention provides 60 to 90% by weight of at least one monomer selected from alkyl acrylates and alkyl methacrylates having an alkyl group having 4 to 10 carbon atoms, methyl or acrylic acid or methacrylic acid. 0.1 to 8% by weight of one or more monomers selected from ethyl esters;
A cationic or nonionic emulsion obtained by emulsifying and dispersing a polymer having a glass transition point of −20 ° C. or less as an essential constituent monomer of 0.01 to 30% by weight of a monomer represented by the following general formula, and the emulsion: The present invention relates to a coating film waterproofing composition comprising 10 to 200 parts by weight of an inorganic hydraulic substance with respect to 100 parts by weight of a resin component therein.

(Where R ₁ is hydrogen or a methyl group, R ₂ is hydrogen or an alkyl group having 1 to 4 carbon atoms) In the present invention, the alkyl acrylate or alkyl methacrylate having an alkyl group having 4 to 10 carbon atoms is , Weather resistance to the coating film obtained from the emulsion, indispensable to impart cold resistance, specifically butyl,
Isobutyl, 2-ethylhexyl, n-octyl, n-
Esters of acrylic acid or methacrylic acid having an alkyl group such as hexyl are mentioned. Esters having an alkyl group having less than 4 carbon atoms cannot be used for the above-mentioned purposes in terms of alkali resistance, and those having an alkyl group having more than 10 carbon atoms cannot be used because of reduced cold resistance. .

The above-mentioned monomers are appropriately selected in the range of 60 to 90% by weight of the total monomers. In the present invention, a methyl or ethyl ester of acrylic acid or methacrylic acid is used as a part of the monomer, but a methyl ester of acrylic acid is preferred for the present invention. These have favorable effects such as causing internal cross-linking of the emulsion by Ca due to hydrolysis with cement alkali and increasing the strength of the coating film. These can be appropriately selected in the range of 0.1 to 8% by weight based on the total monomers, but if it is more than 8% by weight, the water resistance and alkali resistance of the coating film are extremely reduced, and the role of the waterproofing agent is maintained. Can not.

General formula (However, R ₁ is hydrogen or methyl group, R ₂ is hydrogen or carbon number 1
And N-methylolacrylamide, N- (butoxymethyl) acrylamide and the like. Although their effects are unknown, they have effects such as stabilizing the emulsion when mixed with an inorganic hydraulic substance such as cement, enhancing the drying property of the coating film, and enhancing the adhesion to the substrate. The combined amount of these monomers is 0.
It can be appropriately selected in the range of 01 to 30% by weight. When the content is less than 0.01% by weight, the effect is not obtained. More preferably, it is 0.1 to 10% by weight.

Further, in addition to the above two monomers, a monomer having an unsaturated ethylene bond copolymerizable therewith can be used if necessary. Specifically, styrene, acrylonitrile,
Vinyl acetate, vinylidene chloride, etc., and also include all other monomers that are commonly used as copolymer monomers in acrylic polymers, but monomers having a carboxyl group or a sulfonic acid group as a functional group; Ordinary cationic monomers are not preferred because they reduce the stability of the system. These copolymerizable monomers can be added to a weight ratio of about 1/1 to the alkyl acrylate or alkyl methacrylate.

Among the polymers obtained by polymerizing these monomers, those used in the present invention have a glass transition point (hereinafter referred to as Tg point).
Is used because it is a polymer having a temperature of -20 ° C or lower, even if it is applied as a waterproofing agent at a thickness of several hundred μm or more at a time, so as not to cause cracks, cracks and the like.

Here, when using a polymer having a Tg point exceeding −20 ° C., if the film thickness of the waterproofing agent is several hundred μ or more, cracks, cracks, and the like are liable to occur at the time of film formation. Water leakage occurs due to cracks, cracks, etc., and the waterproof performance cannot be sufficiently exerted even with a thick coating.

The second reason is to provide followability to a base crack.

In other words, even if a crack of several mm occurs on the ground due to the movement of the building, the coating does not produce pinholes etc.
It can follow well, and particularly when it is used in combination with the above-mentioned undercoating film, it can follow a remarkably large underground crack.

Conversely, when a polymer having a Tg point exceeding -20 ° C is used, there is almost no crack followability, and almost no effect as a waterproofing agent can be expected.

A composition that forms a waterproof coating containing a polymer having a Tg point of -20 ° C or less has good coatability at low temperatures and excellent film-forming performance. Ideal for membranes.

The Tg point of the polymer used in the emulsion in the present invention is a temperature at which various properties of the amorphous polymer suddenly change, and below this temperature, a temperature at which the motion of the molecular segment of the amorphous portion of the polymer is frozen. is there.

To actually measure the Tg point of the polymer, as an example, measure the thermal expansion at various temperatures, plot the specific volume for each temperature, and calculate the temperature at the point where the curve bends in the obtained curve. Is used.

However, since the value of the Tg point of a polymer composed of individual single monomers is actually known, the value of the Tg point of the copolymer can be obtained by the following formula.

CA; weight fraction of component A CB; weight fraction of component B TgA; Tg of component A homopolymer (゜ K) TgB; Tg of component B homopolymer (゜ K) where CA + CB = 1.

Next, as an example, first, a main homopolymer having a Tg point of −20 ° C. or lower (all the Tg points in the arc) will be described as polyethyl acrylate (−22 ° C.), poly n-butyl acrylate (−54 ° C.).
C), poly 2-ethylhexyl acrylate (-85 C)
When the Tg point is -20 ° C or higher, the polymer includes polymethyl acrylate (8 ° C), polystyrene (87 ° C), polyvinyl acetate (30 ° C), and the like. Examples include polymethacrylic acid (130 ° C.).

Next, an example of calculating the Tg point of the copolymer will be described.
For example, the Tg point of a copolymer of 75 parts of ethyl acrylate and 25 parts of vinyl acetate is −13 ° C. according to the formula (1).

80 parts of 2-ethylhexyl acrylate, 20 parts of styrene
Similarly, the Tg point of the copolymer in part is obtained from the equation (1) as −
It will be 72 ° C.

In addition, the calculation was omitted for trace components with unknown Tg points.

Although the Tg point of the polymer used in the emulsion in the method of the present invention measured as described above is −20 ° C. or less, by using such a soft polymer, it was thickly used as a waterproofing agent. No cracks, cracks, etc. occur during coating.

The acrylic emulsion used in the present invention is obtained by polymerizing the above-mentioned monomer in the presence of a cationic or nonionic surfactant.

Examples of the cationic surfactant that can be used in the present invention include quaternary ammoniums such as trimethyloctadecyl ammonium chloride, trimethyl dodecyl ammonium chloride, trimethyl hexadecyl ammonium chloride, alkyl dimethyl benzyl ammonium chloride, distearyl dimethyl ammonium chloride, and trimethyl stearyl ammonium chloride. Salt or dimethyloctylamine, dimethyldecylamine, dimethyllaurylamine, dimethylmyristylamine, dimethylpalmitylamine, dimethylstearylamine, dimethyloleylamine, trioctylamine, N-methylmorpholin, dimethylbenzylamine, polyoxyethylene alkylamine Such tertiary amines can be exemplified.

As the nonionic surfactant, any of those usually used for acrylic emulsions can be used. For example, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenol ether, polyoxyethylene nonyl phenol ether, polyoxyethylene alkyl and alkyl phenol ethers, sorbitan monostearate, sorbitan Monolaurate, sorbitan distearate,
Sorbitan fatty acid esters such as sorbitan monooleate and sorbitan trioleate; polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate; polyethylene glycol fatty acid esters; and glycerin monofatty acid esters. Among these surfactants, it is preferable to use a polyethylene oxide-based nonionic surfactant having an HLB value of 15 or more, particularly in terms of improving polymerization stability, mechanical stability, and chemical stability.

The amount of the surfactant may vary depending on the properties required for the emulsion. However, in order to improve the stability of the emulsion, it is desirable that the amount of the surfactant is large, and the drying property and the water resistance of the coating film are improved. In order to improve the properties, a smaller amount is desirable. A preferable range of the compounding amount is 1 to 5% by weight based on the polymer solid content of the emulsion, and the compounding amount may be determined according to the purpose.

As a catalyst used for producing the emulsion used in the present invention, there are a general nonionic catalyst and a cationic catalyst. Among them, it is preferable to use 2,2'-azobis (2-amidinopropane) which is a cationic catalyst.

The emulsion used in the present invention is produced by a general emulsion polymerization method.

The cationic or nonionic emulsion used in the present invention preferably has a high concentration, and if the concentration is low, the drying property is poor and the physical properties of the film deteriorate. Therefore, the concentration is preferably about 40 to 65% by weight.

The composition of the present invention is used for a reactive coating film waterproofing and comprises the above emulsion and an inorganic hydraulic substance. Inorganic hydraulic substances are crosslinked by polyvalent metals such as calcium in emulsions,
It affects the adhesion to the substrate and the flexibility and film strength of the coating film. That is, if the amount of the inorganic hydraulic substance is large, the kneadability with the emulsion is deteriorated and the workability is reduced. On the other hand, drying of the coating film is quicker, but the formed coating film is harder and less flexible. As the inorganic hydraulic substance, for example, ordinary bolt land cement, early-strength cement, blast furnace cement, white cement, silica cement, fly ash cement, alumina cement and the like can be used, and alumina cement is particularly preferable. The mixing amount of the inorganic hydraulic substance is 10 to 200 parts by weight based on 100 parts by weight of the resin component in the emulsion. If the amount is less than 10 parts by weight, the drying property of the coating film is slow. If the amount is more than 200 parts by weight, the physical properties of the formed coating film, especially the elongation, are deteriorated and the film does not function as a waterproof material. More preferably, it is 20 to 70 parts by weight.

When an aggregate is used in combination with the composition of the present invention, effects such as improvement of coating properties, securing of coating film thickness, toughness of coating film, flexibility, reduction of tack and improvement of kneading properties are recognized. . The amount of the aggregate is preferably about 20 to 600 parts by weight based on 100 parts by weight of the inorganic hydraulic substance. If the amount is less than 20 parts by weight, the amount of the inorganic hydraulic substance becomes excessive and the formed film has poor elongation properties, and if it is more than 600 parts by weight lacking the flexibility of the film, the effect of the inorganic hydraulic substance is reduced. More preferably, it is 150 to 400 parts by weight. Specific examples of aggregates include silica sand, talc,
Foams, mica, ferrite, etc. of calcium carbonate, gypsum, diatomaceous earth, titanium oxide, silica, perlite, etc.
Examples thereof include carbon black. Further, a fibrous material can be blended if necessary.

When the composition of the present invention is used for waterproofing, a thickening agent which is further blended with a normal coating film waterproofing agent, if necessary,
An antifoaming agent, a film forming aid, and a reaction retarder can be added.

The method of waterproofing with the composition of the present invention is not particularly limited, but the emulsion, the inorganic hydraulic substance and the aggregate are mixed at the construction site with a mixer, and a brush, a roller brush, a coating method using a rubber lake or the like is applied. It is performed using a spraying method with a gun.

In application, the viscosity of the waterproofing composition using the emulsion of the present invention is preferably set to about 4000 to 15000 cps in order to obtain a large coating thickness in one application.

The material of the construction surface is not particularly limited, and the construction surface can be directly constructed on a structure made of concrete, mortar, or the like, or can be constructed on slate, metal, glass, plastic, or the like.
In addition, in order to improve the adhesion to the substrate, it is preferable to apply after applying a suitable primer according to a conventional method. The waterproofing composition using an emulsion may be colored for the purpose of cosmetics. Further, another paint can be applied as a top coat on the waterproof film.

〔Example〕

Hereinafter, the composition of the present invention will be described more specifically with reference to Examples and Comparative Examples.

Production of Emulsion-1 114.2 parts of ion-exchanged water was placed in a stainless steel reactor equipped with a stirrer having an inner volume of 500 l, and the internal temperature was heated to 80 ° C., followed by 231 parts of 2-ethylhexyl acrylate, 9 parts of methyl acrylate, and 51 parts of styrene. N-methylolacrylamide 9 parts Polyoxyethylene nonylphenol ether (HLB-18.9) surfactant 5 parts as emulsifier, defoamer
A mixture of 0.03 parts and 100 parts of ion-exchanged water, a solution consisting of 2.2 'as a polymerization initiator, 1.2 parts of azobis (2-amidinopropane) hydrochloride and 10.8 parts of ion-exchanged water are continuously added to carry out a polymerization reaction. After 4 hours, the polymerization reaction was completed to obtain the emulsion of the present invention. This emulsion consisted of 56% of a resin having a glass transition point of -58.3 ° C. and had a viscosity of 256 cps and a pH of 5.7. (This emulsion is referred to as No.-1.) (Freezing and thawing stability) 400 cc of the above emulsion No.-1 is put in a polyethylene bag, sealed, and then left in a thermo-hygrostat manufactured by Nagoya Scientific Instruments Co., Ltd. at −10 ° C. 6 After 8 cycles under the conditions of 60 ° C. for 6 hours, the emulsion state was observed, but no suspicious matter was generated and the viscosity was 290 cps, which was good.

Emulsion Production-2 An emulsion was produced under the raw material composition and polymerization conditions shown in Table 1, and the viscosity and resin content of the resin were measured.

Examples 1 to 10 Using the obtained emulsions, waterproof compositions having the composition shown in Table 2 were prepared, and various physical properties and film physical properties were measured. The results were described in Second Examples 1 to 10, Good results were obtained.

Each test method is as shown below.

(Pot life) Put the kneaded waterproofing composition in a polyethylene cup.
The viscosity was measured by standing in a constant temperature room at 20 ° C., and the time when the viscosity was 30,000 cps or less was defined as the pot life.

(Coating film curing time) An epoxy primer is applied to a 300 x 300 x 3 m / m slate plate, and the kneaded waterproofing composition is sprayed to a flow rate of ² kg / m2, and the mixture is placed in an atmosphere at 20 ° C and 60% RH. The specimen was allowed to stand and subjected to a weight test to measure the curing time of the coating film.

* Weight test: Stand a pencil on the coating surface, apply a 1kg weight for 15 seconds, and measure the time until almost no pencil mark is left on the coating surface.

(Adhesion) an epoxy-based primer was applied to a slate plate of 150 × 300 × 6m / m, poppy spray a waterproofing composition as to be 2 kg / m ² was kneaded, 20 ℃, 60% RH atmosphere After 2 weeks, the adhesion was measured with a Kenken-type tensile tester.

(Film physical properties) The tensile test was performed in accordance with JIS A 6021 “Roof prevention coating material”.

(Swelling ratio after immersion in water) A test film was punched out from the coating film used for film physical properties with a dumbbell No. 3 mold, left in water for one week, and the length of the coating film immediately after being taken out of the water was measured.

Emulsion Production-3 An emulsion was produced under the raw material composition and polymerization conditions shown in Table 3, and the viscosity and resin content of the resin were measured.

Example 11 Using the obtained emulsion No.-13, a waterproofing composition having the composition shown in Table 4 was prepared, and various physical properties and film physical properties were tested by the same test methods as in the above Examples.

The results are as shown in Table 5, and those using a polymer emulsion consisting only of the essential constituent monomers in the present invention are also excellent coating film waterproofing compositions.

Comparative Examples 1 to 9 Using the obtained emulsions, various physical properties and film physical properties of two types of waterproofing compositions having the composition shown in Table 2 and a commercially available waterproofing material were tested by the same test methods as in the examples. The results are shown in Table 2 Comparative Examples 1 to 9. As can be seen from Comparative Example-1, without the cement, the coating film hardening time is long, the strength of the film is reduced, and the swelling ratio when immersed in water is poor.

In Comparative Example 2, acrylamide was used, but the curing time of the coating film was as long as 21:00 or more, and the curing time could not be improved.

In Comparative Example-3, when an emulsion excluding the acrylamide-based monomer, which is an essential condition in the present invention, was used, the viscosity increased violently immediately after kneading, resulting in gelation.

In Comparative Example-4, since an emulsion was used in which the methyl or ethyl ester of acrylic acid or methacrylic acid, which is an essential condition in the present invention, was used, the coating film curing time was slow, and the film strength and water resistance were poor.

In Comparative Example-5, an emulsion having a large amount of methyl acrylate was used, so that the pot life was short and workability was poor. In addition, the elongation of the film was reduced, and the swelling ratio after immersion in water became poor.

In Comparative Example-6, since an anionic emulsion was used, the pot life was very short, the gelation was rapid, and a test specimen could not be prepared.

In Comparative Example-7, a cationic emulsion was prepared by copolymerizing a cationic acrylic monomer containing an amino group, but the curing time could not be improved.

In Comparative Example-8, a commercially available ethylene-vinyl acetate emulsion was used, but the film properties at low temperatures, particularly the elongation, were poor.

In Comparative Example-9, a commercially available acrylic rubber-based coating film waterproofing material was evaluated. As a result, the coating film curing time and the swelling ratio after immersion in water were inferior.

As is evident from the above results, the cationic or nonionic emulsion used in the present invention has good freezing stability and does not rapidly increase in viscosity or gel even when an inorganic hydraulic substance and an aggregate are blended. Has sufficient pot life. In addition, the waterproofing composition of the present invention has excellent performance in weather resistance, adhesion, flexibility, water resistance and the like even in a coating film obtained by forming a coating film very quickly.

(C) Effects of the Invention The following effects can be obtained by the composition of the present invention.

(1) A composition having a good pot life because the cationic or nonionic emulsion used has excellent stability and stability is not impaired even when an inorganic hydraulic substance such as cement and an aggregate are blended. Becomes

(2) The cationic or nonionic emulsion used is excellent in freeze-thaw stability, and can be easily returned to the original emulsion state even when frozen during storage.

(3) The composition of the present invention has a very high film-forming rate,
The restrictions on the construction conditions as a waterproofing agent were greatly reduced, and the construction period could be shortened.

(4) Self-leveling is good and a smooth coating film can be easily obtained.

(5) Since the coating film has good weather resistance and good flexibility, it can sufficiently follow the deformation and cracking of the base and has excellent waterproof performance.

(6) Even in a low temperature environment, the elongation of the coating film is not lost, and the coating film hardly deteriorates.

(7) Because of good water resistance, re-emulsification due to rainwater or the like hardly occurs, and blistering of the coating film hardly occurs.

 ──────────────────────────────────────────────────の Continuing from the front page Judge of the Joint Panel Judge Yoshinobu Ishida Judge Hisao Tanaka Judge Eriko Suzuki (56) References JP-A-60-137917 (JP, A) JP-A 58-4747 (JP, B2) 1984-1984 (JP, B2)

Claims (1)

(57) [Claims] An alkyl acrylate and an alkyl methacrylate having an alkyl group having 4 to 10 carbon atoms, and 60 to 90% by weight of at least one monomer selected from the group consisting of methyl and ethyl acrylate or methacrylate. 0.1 to 8% by weight of one or more monomers selected from esters, 0.01 to 30% by weight of a monomer represented by the following general formula are essential constituent monomers, and the glass transition point is -20 ° C. A cationic or nonionic emulsion obtained by emulsifying and dispersing the following polymer and an inorganic water-curable substance for 100 to 100 parts by weight of a resin component in the emulsion for coating film waterproofing characterized by comprising 10 to 200 parts by weight. Composition. (However, R ₁ is hydrogen or a methyl group, R ₂ is hydrogen or an alkyl group having 1 to 4 carbon atoms.)