JPS60238311A - Fluorine-containing acrylic resin and elastic finish structure of exterior wall having said resin as top layer - Google Patents

Abstract

PURPOSE:To provide the titled resin for the coating of exterior wall material, having specific molecular weight and glass transition point, and giving a coating film free from cracking and peeling, by copolymerizing an alkyl acrylate, fluoroalkyl acrylate and glycidyl acrylate, etc. CONSTITUTION:The objective resin having a molecular weight of 80,000-150,000 and glass transition point of 30-60 deg.C can be prepared by copolymerizing (A) 50-80mol% one or more alkyl (meth)acrylate monomer, (B) 15-30mol% one or more fluoroalkyl (meth)acrylate monomer, etc. and (C) 5-20mol% one or more monomers selected from glycidyl (meth)acrylate, tetrahydrofuryl (meth)acrylate, etc. An elastic finished structure of exterior wall can be produced by coating an external wall material with an elastic intermediate finishing material, and then with a paint composed of the above resin as the top coating layer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluorine-containing acrylic resin and an outer wall elastic finishing structure using the resin as a top layer.

BACKGROUND ART Conventionally, since fluororesins have excellent weather resistance, heat resistance, chemical resistance, etc., paints containing these resins as main components have recently come into practical use in a wide variety of industrial fields. However, in general, perfluoroethylene,
Homopolymers or copolymers of fluoroolefins such as chlorotrifluoroethylene and perfluoropropylene are often used, but since they are insoluble in organic solvents, they require heating and melting when used as a coating, which poses problems in workability and increases material costs. There are problems with high prices. Therefore, fluoroolefins, vinyl chloride, vinyl acetate,
Modified fluororesins copolymerized with alkyl acrylates, alkyl methacrylates, etc. have been proposed, but they have problems with adhesion to the substrate in paint applications, and the resulting coating film is hard, causing vibration and expansion/contraction behavior of the substrate. It is not possible to follow the conditions in which the paint is applied, and defects such as cracks and peeling occur on the surface of the paint film.

On the other hand, in finishing coatings for exterior wall materials of buildings, in addition to cosmetic properties and base protection properties, waterproof functionality (i.e., preventing the coating film from following vibrations and expansion/contraction displacements and causing the above-mentioned coating film defects) There is an increasing demand for waterproofing.

The purpose of the present invention is to create a new fluororesin that has excellent attributes comparable to conventional fluororesins and modified fluororesins, and to develop its use in paints.

Another object of the present invention is to satisfy the above-mentioned requirements for finishing coating of building exterior wall materials.

As a result of intensive research to achieve this objective, the present inventors have discovered that an acrylic resin containing a fluorine-containing acrylic monomer and glycidyl or tetrahydrofuryl in addition to the alkyl acrylate or alkyl methacrylate used in ordinary acrylic resins. By copolymerizing monomers, the desired fluororesin can be obtained, and if the resin is made into a paint, the weather resistance of the fluororesin will not be impaired.
The adhesion of the base material is improved and elasticity can be imparted, and if such a paint is used as a top paint in the finishing coating of building exterior wall materials, waterproof functionality is ensured due to the conformability of the paint film, and excellent exterior wall elasticity is achieved. They discovered that a finished structure can be obtained and completed the present invention.

That is, the present invention comprises (1) 50 to 80 mol% of a mixture of one or more selected from the group of alkyl acrylates and alkyl methacrylates, and (2) one or two selected from the group of fluoroalkyl acrylates and fluoroalkyl methacrylates. A mixture of 15 to 30
and ■ 1 selected from the group of glycidyl acrylate, glycidyl methacrylate, tetrahydrofuryl acrylate and tetrahydrofuryl methacrylate.
Obtained by copolymerization with 5 to 20 mol% of a species or a mixture of two or more species, and has a molecular weight of 500.

~150,000, a fluorine-containing acrylic resin characterized by having a glass transition point of 30 to 60°C, a top paint for exterior wall elastic finishing structures characterized by having such a fluorine-containing acrylic resin as a main component, and an elastic material for exterior wall materials. In an exterior wall elastic finishing structure in which an intermediate coating finishing material is applied to form an elastic intermediate coating layer, and a top layer is formed by applying a top 1 material to the elastic intermediate coating layer, the above-mentioned exterior wall elastic finishing structure is used as a top coating material. The present invention provides an exterior wall elastic finishing structure characterized by using a top paint.

The fluorine-containing acrylic resin according to the present invention has ■alkyl (
one or a mixture of two or more selected from the group of meth)acrylates (hereinafter, (meth)acrylate refers to acrylate and methacrylate); and one or two selected from the group of fluoroalkyl (meth)acrylates. It is produced by copolymerizing a mixture of at least one species and a mixture of one or more species selected from the group of (1) glycidyl (meth)acrylate and tetrahydrofuryl (meth)acrylate. In addition to the essential monomers (■ to ■), acrylic acid and/or methacrylic acid may be copolymerized as necessary.

Specific examples of the monomer alkyl (meth)acrylate mentioned above include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl acrylate, hexyl acrylate, 2-ethylbutyl acrylate, and pentyl (meth)acrylate. Examples include acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, inoctyl acrylate, nonyl acrylate, and the like. In particular, a monomer that imparts a high glass transition temperature and a monomer that imparts a low glass transition temperature are appropriately selected and used in combination,
It is preferable to adjust the glass transition temperature of the target resin to a desired range. The copolymerization ratio of the monomer (1) is set to be 50 to 80 mol%, preferably 60 to 75 mol% of the total seven monomers. This ratio does not impede the characteristics of the fluorine atoms contained in the target resin, makes it possible to impart elasticity, and is advantageous in terms of economy.

Specific examples of the monomer fluoroalkyl (meth)acrylate mentioned above include 2,2.2-trifluoroethyl (meth)acrylate, 2,2,3°3-tetrafluoropropyl (meth)acrylate, IH9IH15H
-Octafluoropentyl (meth)acrylate, IH
, 'IH, 2H, 2H-heptadecafluorodecyl (meth)acrylate, in particular 2,2,3.3-
Tetrafluoropropyl acrylate, lH, IH, 5
H-octafluoropentyl acrylate is preferred.

Such O monomers, like conventional fluoroolefins,
Because the surface energy is lowered due to the fluorine atoms, it is effective in reducing dust adhering to the surface of the paint film and preventing stains, and also improves water repellency by preventing liquids from getting wet. can be done. The copolymerization ratio is 15 to 30 mol%, preferably 20 to 30 mol% of the total monomers.
The content is set to 25 mol%. If this ratio is
It is advantageous because the above-mentioned effects and economic efficiency of the upper knob are combined.

The above monomer (■) improves the adhesion of the target resin to the base, and its copolymerization ratio is 5 to 5% of all monomers.
The content is set to 20 mol%, preferably 7 to 15 mol%. Since the glycidyl group or tetrahydrofuryl group of the monomer (1) can cause a ring-opening reaction or a crosslinking reaction, it contributes to improving the physical properties of the coating film in addition to improving the adhesive properties mentioned above. In particular, when adding commonly used additives such as pigments when turning the target resin into a paint, as described below, the upper
If the copolymerization ratio is set to 10 to 20 mol %, the reliability of adhesiveness will be improved.

Acrylic acid and methacrylic acid, which are copolymerized as necessary, are used to adjust the hardness and glass transition temperature of the target resin, or to reduce costs, but if they are too large, they reduce chemical resistance, so they are usually used. The copolymerization ratio may be set to 10 mol% or less based on the total monomers.

The above copolymerization may be carried out in a conventional manner. For example, when solution polymerization is employed, a predetermined ratio of copolymerizable monomers is heated and stirred at a temperature of usually 70 to 100°C for 4 to 24 hours in the presence of a polymerization initiator in a reaction solvent (to remove residual unreacted material, 0.5% by weight or less) to carry out copolymerization. In this case, gelation during polymerization can be prevented by setting the solid content in the reaction solvent to 30 to 60% by weight. Examples of the reaction solvent include ketone type (methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ester type (ethyl acetate, cellosolve acetate, etc.), aromatic type (toluene, xylene, etc.), alcohol type (n-butanol, Examples include methyl cellosolve, butyl cellosolvenato), and methyl ethyl ketone and ethyl acetate are particularly preferred from the viewpoint of reducing the viscosity of the solution polymer. Examples of the polymerization initiators include penzoyl peroxide, cumene hydroperoxide, [-butyl hydroperoxide, methyl ethyl ketone oxide, cyclohexanone peroxide, dicumyl peroxide, di[-butyl oxide, L-butyl Examples include peroxyacetate, acetyl peroxide, azobisisobutyronitrile, and the like. The amount of the polymerization initiator used may be appropriately set depending on its type and polymerization conditions, and is usually 0.01 to 5% based on the total amount of copolymerization monomers.
It may be selected in the range of 0.1 to 1.0% by weight, especially since high molecular weight is required to obtain the desired elasticity.
is preferred.

The fluorine-containing acrylic resin produced in this way is
Molecular weight by G, P, C1 method 5oooo~150000
It has a glass transition temperature of 30 to 60° C. as determined by differential thermal analysis, and can be used as a top coating material for exterior wall elastic finishing structures, which will be described later.In addition to such uses, it is also useful as a water repellent.

The top paint for exterior wall elastic finishing structures according to the present invention is composed of the above-mentioned fluorine-containing acrylic resin as a main component,
It may be used as a transparent paint, or it may contain 20 to 30% by weight of pigments such as titanium and red iron to adjust the color tone. In addition, a suitable organic solvent (for example, the reaction solvent used in the resin production) may be blended to adjust the Stoyer viscosity to 40.
If it is set to ~9Qku, it can be applied to any of roller coating, brush coating, or spray coating, and smooth coating work can be achieved.

The present invention is characterized in that the above-mentioned top paint is used in finishing coating of building exterior wall materials.

Usually, JISA6910 is used for finishing coating of building exterior wall materials.
Standard "multi-layer pattern spray finishing material" is often used in
In recent years, finishing materials that impart elasticity have been put into practical use in order to improve the waterproofing function of buildings.

The exterior wall elastic finish structure according to the present invention is comprised of an exterior wall material, an elastic intermediate coating layer, and a top layer laminated in sequence, and is characterized in that the above-mentioned top paint is used to form the top layer.

In forming the elastic intermediate coating layer, an elastic intermediate coating finishing material is used, which is a resin emulsion (acrylic resin emulsion, acrylic-styrene copolymer resin emulsion, vinyl acetate-ethylene copolymer resin emulsion, etc.)
and/or a rubber emulsion (such as an acrylic rubber emulsion) as a main component, and an appropriate amount (preferably 40 to 70% by weight) of filler or aggregate such as calcium carbonate, clay, or silica sand, and further an additive to adjust the viscosity. sticky agent (
(e.g., cellulose), pigments such as titanium, red iron oxide, fibers, preservatives, antifreeze agents, plasticizers, solvents, and other commonly used additives.

As such intermediate coating finishing material, for example, JIS A60
Although it does not completely pass the physical properties of the "roof waterproof coating material" specified in 21, it includes those that generally pass with the exception of some items.

The outer wall elastic finishing structure of the present invention is manufactured as follows. First, apply the above-mentioned elastic intermediate coating finishing material to the exterior wall material once or in 2.3 times using a roller, brush, spray, etc. (in this case, the total application amount is 9/I for a total application amount of 1.5 to 4.0), After drying, an elastic intermediate coating layer having an average thickness of about 0.5 to 2.0 mm is formed. Next, apply the above-mentioned top paint to the elastic intermediate coat layer once or in two or three times using a roller, brush or spray (total coating amount in this case 0.5 to 1.5 to 1),
Dry to form the top layer.

With the exterior wall elastic finish structure obtained in this way, if a normal acrylic resin paint is used as the top paint, the adhesion with the elastic intermediate finish material is insufficient, so JIS
In the freeze-thaw test items of A6910, blistering and peeling of the top layer can be seen after several cycles, but in the case of the present invention, even after 20 or more freeze-thaw cycles, the adhesion between the laminated layers is excellent, and the top layer Since the paint is elastic, abnormalities such as blistering and peeling are not observed.

Furthermore, regarding the excellent physical properties of the outer wall elastic finished structure of the present invention, for example, in a test according to the JIS A6021 standard, the tensile strength at normal state is 10 to 50 KP/ctf, the elongation rate to break is 100 to 500%, and the low temperature ( -20
°C), the tensile strength is 10 to 100 KIi/d and the elongation rate to break is 5 to 50%, and the physical properties after heat aging also have a tensile strength of 10 to 100/9/aR and an elongation rate of 100 to 500%, respectively. It is clear from this. In addition, the change rate at low temperature compared to the physical properties under normal conditions is 100 to 1000% in the case of tensile strength and 1 to 50% in the case of elongation.
%Met.

Next, the present invention will be described in more detail with reference to Examples. Note that "parts" in the example sentences means "parts by weight."

Examples 1 to 7 and Comparative Examples 1 and 2 The parts of copolymerizable monomers, reaction solvent (toluene, ethyl acetate) and polymerization initiator (benzoyl peroxide) shown in Table 1 were accurately weighed, and these were placed in a reaction vessel. A fluorine-containing acrylic resin is obtained by heating and stirring at 80° C. for 8 hours in a nitrogen atmosphere.The molecular weight and glass transition point of this resin are also listed in Table 1.

Examples 8 to 14 and Comparative Examples 3 and 4 To 100 parts of each fluorine-containing acrylic resin solution synthesized in Examples 1 to 7 and Comparative Examples 1 and 2, 20 parts of titanium oxide was added, glass beads were added, and a tabletop sand mill was used. A white fluorine-containing acrylic resin top paint is obtained.

Next, an acrylic rubber-based elastic spray material Beta All Super 3200 (manufactured by Sunstar Giken Co., Ltd.) was applied to the glass plate to a dry film thickness of approximately 1 mm, and after drying for 20'C/1 day, the above-mentioned top paint was applied. diluted twice with thinner to approximately 0.
Coat at a coating weight of 6 kg/d and dry at 20°C for 77 days. After that, the coating sheet was removed from the glass plate, turned over and further dried at 20°C for 7 days.
, vm'/min to measure the tensile strength and elongation at break (heat treatment and alkali treatment methods for the tensile test were performed according to JIS A-6021).

The results are shown in Table 2.

On the other hand, it was coated on a slate board treated with Beta All Super 3200t-sealer (using Beta All Sealer manufactured by Sunstar Giken Co., Ltd.) at a coating amount of about 2 to 9/d, and after drying at 20°C for 1 day, the above The top paint diluted twice with thinner was applied at a coating amount of about 0.6 Ky/d and dried at 20°C for 7 days. Using this as a standard test specimen, 60 degree specular gloss was measured using a gloss needle, and water permeability and weather resistance tests were conducted in accordance with JIS A-6910. In the water repellency test, the specimen is immersed in 10% carbon-dispersed water for about 1 minute, then taken out and left standing vertically for about 10 minutes, and the residual state of carbon is visually evaluated. In the stain resistance test, after being immersed as described above, the sample is taken out and left horizontally for about 1 hour, and the remaining carbon is visually evaluated after washing off the attached carbon with running water. In addition, the adhesion test was carried out in the standard state, and in the standard state, the specimen was immersed in water (underwater/7
(day), repeated hot and cold treatment [(18 hours in water +-20°C)
JI
Perform the basic test specified in SK-5400. In addition,
The test specimens after each treatment were left at 20° C. for 4 hours before testing. The results are shown in Table 3.

Comparative Example 5 Same operation as in Examples 8 to 14 except that a commercially available acrylic resin top paint (Beta All Super Top S manufactured by Sunstar Giken Co., Ltd.) was used instead of the top paint containing a fluorine-containing acrylic resin. A paint test was conducted under the following conditions and the results are shown in Tables 2 and 3.

Comparative Example 6 A paint test was conducted under the same operations and conditions as in Examples 8 to 14, except that a commercially available acrylic resin paint (diamond colored finishing material DL) was used instead of the top paint containing a fluorine-containing acrylic resin. are shown in Tables 2 and 3.

Claims (1)

[Claims] 1. 50 mixtures of one or more selected from the group of alkyl acrylates and alkyl methacrylates;
~80 mol%; ■ 15-30 mol% of one or more mixtures selected from the group of fluoroalkyl acrylates and fluoroalkyl methacrylates; and ■ glycidinogen acrylate, glycidyl methacrylate, tetrahydrofuryl acrylate, and tetrahydrofuryl methacrylate. 5 to 2 mixtures of one or more types selected from the group
Obtained by copolymerization with 0 mol%, molecular weight 5oooo. A fluorine-containing acrylic resin having a glass transition temperature of 30 to 60°C. 2゜■ One or more mixtures selected from the group of alkyl acrylates and alkyl methacrylates 5
0 to 80 mol%, ■ 15 to 30 mol% of one or more mixtures selected from the group of fluoroalkyl acrylates and fluoroalkyl methacrylates, and ■ glycidyl acrylate, glycidyl methacrylate, tetrahydrofuryl acrylate, and tetrahydrofuryl methacrylate. 5 to 2 mixtures of one or more types selected from the group
Obtained by copolymerization with 0 mol%, molecular weight 5oooo. 150,000°C and a glass transition point of 30 to 60°C. 3. In an exterior wall elastic finishing structure in which an elastic intermediate coating finishing material is applied to an exterior wall material to form an elastic intermediate coating layer, and a top paint is applied to the elastic intermediate coating layer to form a top layer, the top coating is , ■ 50 to 80 mol % of a mixture of one or more types selected from the group of alkyl acrylates and alkyl methacrylates, and ■ 15 to 80 mol% of a mixture of one or more types selected from the group of fluoroalkyl acrylates and fluoroalkyl methacrylates. 30 mol% and (1) a mixture of one or more selected from the group of glycidyl acrylate, glycidyl methacrylate, tetrahydrofuryl acrylate and tetrahydrofuryl methacrylate 5-2
Obtained by copolymerization with 0 mol%, molecular weight 5oooo. 150,000 DEG C. and a glass transition point of 30 to 60 DEG C.. 4. The elastic intermediate coating finishing material is added to the resin emulsion and/or rubber emulsion with fillers, thickeners, pigments, fibers,
The external wall elastic finished structure according to item 3 above, which is appropriately blended with commonly used additives such as preservatives, antifreeze agents, plasticizers, and solvents.