JPH02222471A - Coating agent having high weather-resistance - Google Patents

Abstract

PURPOSE:To provide the subject coating agent containing a polymer produced by the solution polymerization of a monomer having hydrolyzable silyl group and a vinyl monomer containing a fluorine-containing vinyl monomer and capable of giving a coating film simultaneous to the curing of an inorganic substrate. CONSTITUTION:The objective coating agent contains (A) a monomer having hydrolyzable silyl group and (B) a polymer produced by the solution polymerization of a vinyl monomer containing a fluorine-containing vinyl monomer. Preferably, the component A is (meth)acryloxyalkyl alkoxysilane and the fluorine- containing monomer of the component B is a monomer containing 3-21C perfluoroalkyl group.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention enables painting of ceramic building materials before curing, and furthermore, forms a coating film at the same time as curing the inorganic base material by high-temperature and high-pressure steam curing. The present invention relates to highly weather-resistant coating agents.

[Prior Art] In recent years, there has been a great demand for ceramic building materials, mainly as exterior walls and roofing materials for residential buildings. This is because it has good weather resistance, durability, and appearance. Ceramic building materials are obtained by molding inorganic base materials and curing and curing them, but for the sake of beauty and protection, surface coating is performed by various methods after molding the inorganic base materials. There are two methods of surface coating for inorganic base material molded products: one after curing and the other before curing.

(1) Painting methods after curing and curing include: ■ Applying paint directly to the surface of the molded product and drying; ■ Applying a colored cement slurry to the surface of the molded product immediately after curing and applying colored or transparent paint after curing. A drying method is used.

(2) As a coating method before curing and curing, immediately after molding the inorganic base material, ■ apply a colored paint, ■ apply a colored cement slurry and then apply a transparent paint, or ■ apply a composite coating of a colored cement slurry and a synthetic resin emulsion. There is a method of curing and drying after applying a coating such as coating wood.

(3) In recent years, the durability of paint films (weather resistance, water resistance, adhesion, secondary efflorescence, etc.) and the appearance of paint films (discoloration, deterioration, cracking, bubbles, secondary efflorescence, etc.) With the increasing demand for lighter weight and higher strength ceramic building materials in order to improve performance (e.g.), shorten the production process, and reduce production costs, we are incorporating high-temperature and high-pressure steam curing into the production process. A method has been proposed in which a coating agent is applied before curing to simultaneously cure the inorganic substrate and harden the coating agent. As a coating agent used for this purpose, for example, a synthetic resin emulsion described in JP-A-63-61011 is known.

[Problems to be solved by the invention] Both conventional methods (1) and (2) are insufficient to improve the durability of the coating film, improve the appearance of the coating film, shorten the production process, reduce production costs, etc. However, there were problems such as a decrease in the gloss of the coating film, discoloration, and the occurrence of cracks due to long-term use. Also (2)
In this case, there were problems such as wet film-forming properties caused by the synthetic resin emulsion and deterioration of the coating film due to alkaline content generated during curing. Method (3) is useful for shortening the production process and reducing production costs.

However, commonly used acrylic emulsions have poor wet film-forming properties and efflorescence prevention properties, and furthermore, heating significantly accelerates alkaline deterioration of the coating film, making it difficult to apply the coating before curing with high-temperature, high-pressure steam. There was also the problem that the resulting ceramic building materials lacked durability. That is, until now, there has been no coating agent that can be applied to high-temperature, high-pressure steam curing methods and that can achieve both the formation of a coating film and the durability of the coating film.

As described above, none of the conventional coating methods and coating agents has been able to satisfy the currently increasing demands for maintenance-free, high durability, and high stain resistance.

[Means for Solving the Problems] The present inventors have focused on the property of coating agents that harden due to moisture, and have further improved the durability of the coating film by applying the coating while the substrate is wet and then heating it. The present invention was achieved as a result of various studies on a method for increasing the amount of water and a coating agent suitable for the method.

That is, the present invention is a polymer obtained by solution polymerization, the constituent components of which are a monomer unit (a) containing a hydrolyzable silyl group and another vinyl monomer unit (b). It is a highly weather-resistant coating agent that forms a coating film under high temperature and high humidity conditions.

In the present invention, the monomer that becomes the monomer unit (a) containing a hydrolyzable silyl group has the following formula % [wherein, R2 is an organic group having a polymerizable double bond, and R2 is the number of carbon atoms] A monovalent hydrocarbon group selected from 1 to 10 alkyl groups, aryl groups and aralkyl groups, X is from the group consisting of halogen, alkoxy, acyloxy, ketoximate, amino, acid amide, aminooxy, mercapto and alkenyloxy groups selected hydrolyzable group, n is 1
The hydrolyzable silyl group-containing vinyl compound represented by the following formula represents an integer of 3 to 3. Specifically, for example, hydrolyzable silyl group-containing vinylsilane [CH2=CH51(O
CH3) 3, CH2=CH51 (OCH2CH3)
a, CI, =CH5i(OCH2CH20Ct13)
3, etc.], hydrolyzable silyl group-containing (meth)acryloxysilane [CH2=CIC0OCH2CH2CH2S
l (OCRs) a, CH2=CHC00CHzCH
zCH2Si(OCH2CHs) s, cH2=CHC
0CH2CH2CH2SiC], , allylsilane containing group [CH2=CHCH251(OCH2CH3)
s, CH2=CHCH2NHCH2CH2CH25i
(OCH3) 3, C, PISCH20COCH=CH
,,C,F,C1,DCDC(Me)=CH2,CF3
(cF2) zcH20cOc(Me)=CHz, C
F s (cF 2) S (cI(2) 20 COC
(Me) = CH2, CF s (cF 2) s (
cH2) 20COC(Me)=CH2, other hydrolyzable silyl group-containing unsaturated silanes [CHz=CHCg
H4CH2CH,5i(OCHs) s, CH2=(J
IC6H4CH2NHCH2CH2CH2Si (OC
H2CH3) 3, etc.].

Among these, hydrolyzable silyl group-containing (meth)acryloxysilane is preferred.

Examples of other polymerizable monomer units (b) include fluorine-containing vinyl monomer units (c). Specific examples of monomers providing the unit include the following compounds.

(1) The following perfluoroalkyl group-containing (meth)acrylic acid ester: C, F,, CHzCHCH, OCOC(Me)=CH,
, H CsF I 7 (cH2) I+ 0COC(Me)
=CH2,C? F r 5cON (Et) (cH
2) 20COC(Me) = CH2, C6F I3
S02N (Me) (cH2) 20COCH=CH
2. CsF I? 502N (Pr) (cH2)
20COCH=CH2, C8F, isO□N(Me)
(cH2) zOcOc(Me)=CHz, CsF l
7S02N (Me) (cH2) 1oOcOcH
2cH=cH2, CH2=CHCOOCH2CH2, (:sF l 7SO2N (cHzCHzOCOCH
=Cilz) 2, HCFz(cFz)ycHzOcO
c(Me)=CH2, etc.

C) Maleic acid mono- or diester having a perfluoroalkyl group similar to the above (meth)acrylic acid ester: CsF+t (cH2)++DCOCI=CHCOOM
e.

Cl1F! 7 (cH2)+10CDCI=CHCOO
CH2C7FIS etc.

(3) Vinyl ether having the same perfluoroalkyl group as above is allyl ether: C7FISCH2
0CH=CH2, (, rF+5CHzOCHzCH=C
tlz etc.

(4) Vinyl sulfonic acid having a perfluoroalkyl group similar to the above (meth)acrylic acid ester: C, P, 7SO2NHCH2SO□Cll=CH, etc.

(5) Fluoroolefin monomers: chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, etc.

[In the above, Et represents an ethyl group, and Pr represents a propyl group. ] Preferred among these are (meth)acrylic esters containing a perfluoroalkyl group having 3 to 21 carbon atoms.

Monomers that provide other polymerizable monomer units other than (c), which may be used as necessary, include (meth)acrylic acid alkyl esters [alkyl esters having 1 to 12 carbon atoms, such as methyl (meth)acrylate, Ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, etc.]; Hydroxyalkyl (meth)acrylate (alkyl group has 2 to 1 carbon atoms)
0) [hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxyhexyl (meth)acrylate]; aromatic vinyl monomer (styrene, α-methylstyrene, α-chlorostyrene, etc.);
Halogen-containing monomers (vinyl chloride, vinylidene chloride, etc.); alkyl or cycloalkyl vinyl ethers (methyl vinyl ether, cyclohexyl vinyl ether, etc.); vinyl esters (vinyl acetate, etc.); nitrile group-containing monomers (acrylonitrile, etc.); amide group-containing Monomers [(meth)acrylamide, crotonamide, N-methylolacrylamide, fumaric acid diamide, etc.];
Carboxyl group-containing monomer [(meth)acrylic acid, ? L
/inic acid, maleic anhydride, etc.]; Non-hydrolyzable silyl group-containing monomers include, for example, alkylsilane-containing monomers such as trimethylvinylsilane, tributylvinylsilane, dibutylmethylvinylsilane, allyltrimethylsilane, and trimethyl. Examples include vinyloxysilane and allyloxytrimethylsilane. 1,3.5-)samethyl-1 as a monomer containing a polysiloxane group
, 3,5-trivinylcyclotrisiloxane, 1.1.
1.3.3-pentamethyl-3-vinylsiloxane, C
H2=C(cH3)C00(cH2) 3si[03i
(c1, > 311, CH2=CHCOO(cH2)
s [Si (cH3) 20] ,,Si (cH3
) s, CHz=C(cHs)C00CgH4[5i(
cH3)zO]n5i(cHa)a, CH2=C(cH
3) C00 (cH2) 3 [sl (cHa) 20]
,,St (cl(,) 3, Cl2=C(c)+3)
COO (cH2), [Si (cH3) (c, tl
s)0]hSi (cH3) 3, Ctlz=C(cH
s) COO (cHz) a[si (c6H5) 20
],,5i(cL)s,CHz=CHSt(0[5i
(ctla) 201-St (cH3) 3) a
(However, n=0 to 130).

Preferred among these are alkyl (meth)acrylates and aromatic vinyl monomers, and particularly preferred are methyl methacrylate, n-butyl acrylate, and styrene.

The content of each unit in the copolymer is usually 1 to 3 (a)
0 parts by weight, (b) is 70 to 99 parts by weight, preferably (a) is 2 to 20 parts by weight, and (5) is 80 to 98 parts by weight, particularly preferably (a) is 3 to 10 parts by weight. Parts by weight, et al.
is 90 to 97 parts by weight. If (a) is less than 1 part by weight, the applied coating film will not be sufficiently cured and the coating film will become brittle or have poor adhesion. If it exceeds 30 parts by weight, the crosslinking density of the coating film due to curing of the silyl groups under the high temperature and high humidity conditions in an autoclave will be too high, causing cracks in the coating film. If (b) is less than 70 parts by weight, 30 parts by weight of (a)
If it exceeds 99 parts by weight, the result will be the same as if (a) is less than 1 part by weight.

Furthermore, when (c) is introduced as a unit of (b), the weather resistance of the resulting coating film is further improved and stain resistance is also exhibited. (c)
The content of the units is usually 1 to 70 parts by weight, preferably 5 to 50 parts by weight. If (c) is less than 1 part by weight, no improvement in weather resistance due to fluorine will be observed and stain resistance will not be developed. Even if more than 70 parts by weight is used, the weather resistance and stain resistance due to fluorine will not be improved any further, which is uneconomical.

The copolymer in the present invention can be produced by bulk or solution polymerization of each monomer (a) and (b) according to radical polymerization such as thermal polymerization, photopolymerization, or radiation polymerization.

A preferred polymerization method is radical polymerization using a radical initiator in an organic solvent [In the case of solution polymerization, the organic solvents used include aromatic hydrocarbons (toluene, xylene, ethylbenzene, etc.), aliphatic hydrocarbons (hexane, heptane, cyclohexane, etc.), aliphatic esters (ethyl acetate, n-butyl acetate, etc.), aliphatic ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, di-
n-butylketone, cyclohexanone, etc.), aliphatic ethers (dioxane, tetrahydrofuran, etc.), cellosolves (ethyl cellosolve, n-butyl cellosolve, cellosolve acetate, etc.), halogenated hydrocarbons (carbon tetrachloride, ethylene dichloride, etc.), and these Examples include mixtures of two or more of these. Preferred are toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, n-butyl acetate, cellosolve acetate and ethylene dichloride, singly or in mixtures of two or more thereof.

The ratio of the organic solvent to the total weight of each monomer (a), et al. can be arbitrarily selected, but is usually 0.2:2 to 5:11, preferably 0.5:1 to 2:1.

When carrying out a radical polymerization reaction, the radical polymerization initiators used include azo compounds (azobisisobutyronitrile, azobisisovaleronitrile, etc.), peroxides (
Examples include benzoyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, etc.), redox compounds (benzoyl peroxide/N, N-dimethylaniline, etc.). Preferred are azo compounds.

The amount of the polymerization initiator added is usually 0.001 to 20%, preferably 0.1 to 10%, based on the total solid weight of each monomer (a) and (b).

In some cases, a chain transfer agent (n-laurylmercaptan, n-dodecylmercaptan, 2-dodecylmercaptan, T-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, etc.) may be added to adjust the molecular weight. .

The reaction temperature of the radical polymerization reaction is usually 50 to 150°C, preferably 70 to 130°C. The reaction time is usually 1 to 1
0 hours, preferably 2 to 7 hours.

The end point of polymerization is the double bond absorption (1
This can be confirmed by the disappearance of 648 cm −' ) and by the decrease of unreacted monomers in gas chromatography analysis.

The molecular weight of the polymer containing a hydrolyzable silyl group is not particularly limited, but is usually i,ooo to 100,000, preferably 3,000 to 50,000. Since the polymer contains hydrolyzable silyl groups, it will harden by forming a network structure at room temperature even when exposed to the atmosphere, but in the case of high-temperature, high-pressure steam curing, it will harden even further due to the moisture in the system and the high temperature. promoted. The curing mechanism is based on moisture curing of hydrolyzable silyl groups as shown below.

-3i-0-R+ H2O→ -5i-OH+ R
OH-Si-OH+HO-Si-→-St 0-5i-
+ H20 As the highly weather-resistant coating agent in the present invention, a hydrolyzable silyl group-containing polymer may be used alone to form a film, but other film resins may be added thereto. Other resins include various resins currently used as paints and coatings, such as lacquer paints, acrylic lacquer paints, thermosetting acrylic paints, alkyd paints,
Examples include those used in epoxy paints, ester paints, silicone paints, silyl group-containing paints, and the like. Particularly preferred are those used in silyl group-containing paints.

The coating agent of the present invention may contain, if necessary, a curing catalyst for hydrolyzable silyl groups, stabilizers, solvents, fillers, pigments, and additives (ultraviolet absorbers, heat resistance improvers, leveling agents, anti-sagging agents, matting agents). etc.) can be used in combination.

The curing catalyst for hydrolyzable silyl groups may be those conventionally used as silanol condensation catalysts, such as organic titanate compounds [isopropyl triisostearoyl titanate, isopropyl tri(dioctyl pyrophosphate) titanate, tetraisoprobyl di(lauryl phosphate), etc. phyto) titanates, etc.], organic aluminum compounds (acetalkoxyaluminum diisopropylate, etc.), carboxylic acid type tin compounds (tin dioctylate, dibutyltin dilaurate, dibutyltin malate, etc.)
, sulfide type, mercaptide type, and other sulfur-containing organotin compounds (dibutyltin sulfide, etc.), other carboxylic acid metal salts (sodium acetate, zinc caproate, lead octylate, cobalt naphthenate, etc.), acidic phosphate esters (
monomethyl acid phosphate, dimethyl acid phosphate, diethyl acid phosphate, monobutyl acid phosphate, etc.), carboxylic acids and their acid anhydrides (adipic acid, maleic acid, citric acid, itaconic acid, succinic acid,
Phthalic acid, trimellitic acid, maleic anhydride, phthalic anhydride, etc.), aminosilanes (γ-aminopropyltriethoxysilane, T-aminopropyltrimethoxysilane, etc.), amines and their salts (triethylamine, dibutylamine-2-hexoate, etc.) , cyclic amidine and its salts), and quaternary ammonium salts (tetrabutylammonium hydroxide, etc.). These catalysts may be used alone or in combination of two or more. The amount of curing catalyst added is usually 0.001 to 20% by weight based on the silyl group-containing polymer.

As stabilizers for silyl groups, hydrolyzable esters, alcohols, and complete esters of carbonic acid, halonic acid, phosphoric acid, phosphorous acid, etc. are preferred. Hydrolyzable esters include trialkyl orthoformates (trimethyl orthoformate, orthoformate, trimethyl orthoformate, orthoformate, etc.). triethyl acid, etc.), trialkyl orthoacetate (trimethyl orthoacetate, etc.), silanes (methyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, tetra-n-butoxysilane, vinyltriethoxysilane,
γ-methacryloxypropyltrimethoxysilane, T-
(glycidoxypropyltrimethoxysilane, T-ureidopropyltriethoxysilane, silicate, etc.). Examples of the alcohol include methanol, ethanol, impropatol, isobutyl alcohol, octyl alcohol, cellosolve, methyl cellosolve, and the like. Examples of complete esters of carbonic acid, phosphoric acid, phosphoric acid, and phosphoric acid without P-OH include carbonic acid diesters (dimethyl carbonate, diethyl carbonate, ethylene carbonate, di-n-butyl carbonate, diphenyl carbonate, etc.), oxalic acid triesters (triethyl phosphate, tri-n-butyl phosphate, triphenyl phosphate, etc.), phosphoric acid triester (triethyl phosphate, trilobyl phosphate, triphenyl phosphate, etc.), P-
Examples include phosphoric acid monoesters or diesters without DH (diesters such as diethyl ethyl phosphate and diphenyl phenyl phosphate, methyl dimethyl phosphate, ethyl diethyl phosphate, phenyl diphenyl phosphate, etc.). The amount of stabilizer is preferably 1 to 30% based on the silyl group-containing polymer.

The solvent may be the same as that used in producing the polymer of the present invention, but it is also possible to dilute it with a further solvent. The amount of solvent is usually 0 to 600% by weight, based on the polymer.

Fillers and pigments may also be added. These include extender pigments (calcium carbonate, kaolin, talc, aluminum silicate, Aerosil, etc.), inorganic pigments (titanium oxide, iron oxide,
yellow lead, cadmium oxide, carbon black, aluminum scales, etc.), organic pigments (azo-based, azo lake-based, phthalocyanine-based, quinacridone-based, isoindolinone-based organic pigments, etc.).

It is also possible to mix commonly used ultraviolet absorbers, heat resistance improvers, leveling agents, anti-sag agents, matting agents, and the like.

The coating agent of the present invention may be prepared by mixing the polymer, resin, and other components by ordinary stirring alone, or by dispersing and mixing the polymer, resin, and other components using a mixing device (ball mill, niegu, sand grinder, roll mill, flat stone mill, etc.). It can also be obtained by

The substrate to which the coating agent of the present invention is applied is preferably a ceramic building material. These are roofing and wall materials mainly made of inorganic materials such as cement-based, calcium silicate-based, gypsum-based, and asbestos-based materials. Asbestos calcium silicate board, magnesium carbonate board, asbestos cement board,
There are ALC boards, etc.

These ceramic building materials are obtained by curing their constituent parts with high temperature and high pressure steam. The curing conditions are usually 3 to 16 hours at a temperature of 100 to 220°C, a pressure of 1 to 22 atm, and a steam atmosphere, preferably a temperature of 160 to 200°C, a pressure of 6 to 15 atm, and a steam atmosphere. The time is 5 to 15 hours.

When applying the coating agent of the present invention to ceramic building materials, the coating agent is dissolved and mixed in a suitable solvent, adjusted to a desired viscosity, and applied by any coating method such as spray coating or brush coating. Overcoating is also possible.

The application amount is usually about 5 to 300g/lft” (solid content)
This is the percentage of

The coating film obtained by applying this coating agent and curing under the above conditions has good adhesion as the hydrolyzable silyl group reacts with the inorganic base material. A siloxane bond formed by condensation of a silyl group improves heat resistance and moisture resistance, and also improves the weather resistance of the coating film. Furthermore, the introduction of fluorine further improves the heat resistance during high-temperature, high-pressure steam curing, and further improves the weather resistance of the coating film. Furthermore,
The use of fluorine imparts stain resistance to the coating film, further increasing its added value.

[Examples] The present invention will be further explained below with reference to production examples, comparative production examples, and examples, but the present invention is not limited thereto.

Production Example 1 100 g of xylene was charged into a 300 rd four-piece Locolben and heated to 90° C. while stirring.

CF3(cF2)t(cHz)20cOc(Me)=C
Hz 10g, methyl methacrylate 60. g, n-butyl methacrylate 25 g 1 γ-methacryloxybrobyl trimethoxysilane 5 g 1 n-lauryl mercaptan 2
A mixed solution of g1 and 3 g of azobisisobutyronitrile (hereinafter referred to as AIBN) was added dropwise over 3 hours. After reacting at the same temperature for 2 hours, 3 g of AIBN O was added,
The reaction was continued for an additional 2 hours. In this way, 50% xylene
A solution of polymer was obtained.

Production example 2 Styrene Log, CF3(cF2)S(cH2)20
COCH=CH220g, n-butyl acrylate 20g
1 20 g of methyl methacrylate 1 20 g of n-butyl methacrylate, 10 g of r-methacryloxypropyltrimethoxysilane, 2 g of n-lauryl mercaptan, AIB
Polymerization was carried out in the same manner as in Production Example 1 using 3 g of N to obtain a polymer in a 50% xylene solution.

Production example 3 n-butyl methacrylate 35 g 1 γ-methacryloxypropylmethyldimethoxysilane 15 g 1 (cF3) 2C
F(cF2)11(cH2)20COCH=CH250
g, n-lauryl mercaptan 2 g, AIBN
Using 3 g, polymerization was carried out in the same manner as in Production Example 1 to obtain a polymer in a 50% xylene solution.

Production example 4 Methyl methacrylate 53g1 n-butyl methacrylate 2
2g1 2-ethylhexyl acrylate 10g.

T-methacryloxypropyltrimethoxysilane 10g
Polymerization was carried out in the same manner as in Production Example 1 using 5 g of 2-hydroxyethyl methacrylate, 2 g of n-lauryl mercaptan, and 3 g of AIBN to obtain a silyl group-containing polymer in a 50% xylene solution.

Comparative Production Example 1 Two parts of deionized water were added to a 11 separable kolben equipped with a stirrer, a thermometer, a dropping funnel, a nitrogen gas introduction pipe, and a cooling pipe.
00g, polyoxyethylene octylphenol ether 2g, polyoxyethylene lauryl ether sodium sulfate (12g, and sodium bicarbonate 1g) were charged, and the temperature was raised to 75°C in a water bath while purging with nitrogen.

1 of a mixture (first stage) of 72 g of 2-ethylhexyl acrylate, 55 g of methyl methacrylate, and 55 g of styrene.
0%, 5 g of 10% ammonium persulfate aqueous solution was added to start polymerization, and the polymerization reaction was carried out for 30 minutes. While adjusting the internal temperature to 80°C, the remaining 90% of the mixture was added dropwise over 3 hours, and at the same time, 5 g of 10% ammonium persulfate aqueous solution was added over 4 hours to 8 g of polyoxyethylene octylphenol ether and 0.8 g of sodium polyoxyethylene lauryl ether sulfate. was continuously added over a period of 2 hours to advance the polymerization reaction.

After stirring for 3 hours, 2-ethylhexyl acrylate 18
A mixture (second stage) of g1 methyl methacrylate 14 g 1 styrene 14 g 1 methacrylic acid 2 g was added dropwise over 50 minutes to carry out a polymerization reaction.

After stirring for 3 hours, a mixture (third step) of 12 g of ethylene glycol dimethacrylic acid ester and 5 g of r-methacryloxypropyltrimethoxysilane (third step) was added dropwise over 20 minutes to carry out a polymerization reaction.

After the dropwise addition was completed, the internal temperature was raised to 85° C., and the mixture was further aged for 2 hours, and then cooled to room temperature. Adjust the pH to 8. with ammonia water.
5 and filtered through a 100-mesh wire mesh to obtain a resin emulsion.

Comparative Production Example 2 A resin emulsion was obtained in the same manner as in Comparative Production Example 1. The composition is as follows.

(First stage) A mixture of 61 g of 2-ethylhexyl acrylate, 46 g of methyl methacrylate, and 46 g of styrene (2nd stage) A mixture of 28 g of 2-ethylhexyl acrylate, 22 g of methyl methacrylate, 22 g of styrene, and 3 g of methacrylic acid (3rd stage) Ethylene glycol dimethacrylic acid ester 12g1
γ-methacryloxypropyltrimethoxysilane 5g
Mixtures (Examples 1 to 6, Comparative Example 1.2) Painting agents (Examples 1 to 6, Comparative Example 1.2) were obtained using the amounts (parts by weight) shown in Table 1 below.

Table 1 (1) (Coating film test) 100 parts of Portland cement (parts by weight, the same applies hereinafter)
A mortar paste containing 200 parts of No. 8 silica sand and 95 parts of water was placed on a mold and pressure-molded at 100 kg/cm''. Apply 200μ (dry film thickness) of the agent with a spray gun, leave it to dry at room temperature for 1 hour, and then dry at 60℃ and humidity 8.
Steam curing was carried out for 8 hours in 3 atmospheres of 0% RH, and further autoclave curing was carried out for 10 hours in saturated steam at a temperature of 160 to 180°C to prepare coated molded plates, and each test was conducted. The results are shown in Table-2.

Table-1 (2) note) Catalyst Nidioctyltin dilaurate Table-2 The mark ◎ indicates that the evaluation is particularly excellent.

(Test method and evaluation method) Paint film appearance (2) Abnormalities after autoclave curing (discoloration, deterioration,
Cracks, bubbles, and secondary efflorescence) were visually evaluated.

Weather resistance: The gloss retention rate (%) after 2000 hours of weathering was measured.

Water resistance: After immersing the test plate in tap water at 20℃ for 10 days,
Visual evaluation was performed.

Adhesion: Evaluated by a 2 mm square cellophane tape peel test of the coating film.

Secondary efflorescence: The back side of the test plate was immersed in tap water for 1 day and then air-dried for 1 day. This was considered as 1 cycle, and abnormalities in the coating film were visually evaluated after 10 cycles.

[Effects of the Invention] A coating film obtained under high temperature and high humidity using the highly weather resistant coating agent of the present invention exhibits the following effects.

(1) There is no discoloration, deterioration, cracking, or bubbles, and the efflorescence property is good, and the coating film has an excellent appearance.

(2) Good weather resistance, water resistance, adhesion, and excellent durability.

Claims (1)

[Claims] 1. A polymer obtained by solution polymerization, the constituent components of which consist of a monomer unit (a) containing a hydrolyzable silyl group and another vinyl monomer unit (b) A highly weather-resistant coating agent that forms a coating film under high temperature and high humidity conditions and is characterized by containing a polymer. 2. The highly weather resistant coating agent according to claim 1, wherein the other vinyl monomer unit (b) contains a fluorine-containing vinyl monomer unit (c). 3. A polymer in which (a) is a (meth)acryloxyalkylalkoxysilane and (c) is a vinyl monomer unit containing a perfluoroalkyl group having 3 to 21 carbon atoms,
The content of (a) in the polymer is 1 to 30% by weight, (c)
The highly weather resistant coating agent according to claim 2, wherein the amount is 1 to 70% by weight. 4. The highly weather resistant coating agent according to any one of claims 1 to 3, wherein the coating film is formed under high temperature and high humidity conditions at the same time as curing of the inorganic base material under high temperature and high pressure steam.