JPS61270275A - painted natural marble - 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 new and useful painted natural marble, and more particularly, to a natural marble coated with a non-yellowing type urethane paint, used in arts, crafts or architecture. Regarding vine natural marble used in various fields.

Natural marble has been widely used for arts, crafts, and architectural decorations since the Roman era due to its appearance, patterns, tones, and colors. However, because the main component is calcium carbonate, the exterior walls of buildings, sculptures, and other arts and crafts can be affected by acidic substances in the air or acid rain, causing them to become ``fading'' or discolored, or become too hard. If the concrete is used for stairs, handrails, floors, etc., it may become contaminated with contaminants over the years, its shape may change due to wear and tear, or if it is attached as a thin plate to a concrete surface with adhesive, etc. It has defects such as the scum inside seeping out onto the surface of the natural marble, forming scum crystals and discoloring the surface, spoiling its appearance.

[Prior art and problems to be solved by the invention]
In addition, up until now, a special operation called ``polishing (puff finishing)'' had been set up to obtain natural marble with a glossy appearance.

However, these processing operations themselves lack productivity, and moreover, satisfactory results cannot be obtained with these processing operations alone, and for this reason, there are many fields in which this type of natural marble is used as a material. At present, it is difficult to find an improvement measure for removing such defects.

[Means for solving problems]

In view of this situation, the inventors of the present invention considered painting the stone surface as one method to protect it, and as a result of further studies on paints suitable for painting natural marble, they discovered that it is possible to protect the stone surface. In natural marble obtained by painting with non-yellowing urethane paint, the above-mentioned defects can be solved without damaging the appearance characteristics, and in addition, with marble whose surface condition is to a certain degree, by painting with IF paint, the present condition can be solved. The inventors have discovered that a glossy appearance similar to that achieved with polishing can be obtained without performing the polishing work (puff finish) that is commonly used, and have completed the present invention.

That is, the present invention provides "natural marble whose surface is coated with a non-yellowing urethane paint."

Non-yellowing urethane paints that can be used in the present invention include those made from a combination of polyester polyol and non-yellowing polyisocyanate, those made from a combination of polyether polyol and non-yellowing polyisocyanate, and those made from a combination of polyester polyether polyol and non-yellowing polyisocyanate. Examples include combinations with modified polyisocyanates, and non-yellowing polyisocyanates with copolymer polyols obtained by copolymerizing vinyl monomers such as acrylic monomers and vinyl fluoride. From the viewpoint of image quality, durability, abrasion resistance, stain resistance, chemical resistance, etc., those obtained by a combination of a copolymer polyol and a non-yellowing polyisocyanate are most preferred.

As such copolymer polyols, for example, Japanese Patent Publication No. 43-9240.47-13187.47-1318
No. 9 Publications 1 U.S. Patent No. 3,539,658 (19
70), JP-A-55-21450.55-43166.
56-98266.57-51706.59-4132
Aromatic vinyl monomers such as styrene and vinyltoluene; methyl (
Acrylic monomers without functional groups such as meth)acrylate, butyl (meth)acrylate, perfluorocyclohexyl (meth)acrylate, etc.; 2-hydroxyethyl (meth)acrylate, (meth)acrylic acid ~
Acrylic monomers and copolymerizable compounds with hydroxyl groups such as Cardura E+O; α, β-unsaturated carboxylic acids such as (meth)acrylic acid and fumaric acid; or glycidyl (meth)acrylate; fluoroolefins such as vinylidene fluoride α, β-unsaturated carboxylic acid to dieboxide equimole adduct; vinyl ethers; copolymerizable unsaturated bond-containing polyester resins (including oil-modified types); amide group-containing vinyl monomers such as (meth)acrylamide; So-called "acrylic polyol" which has a hydroxyl group that reacts with an isocyanate group in the molecule, which is obtained by copolymerizing a phosphorus atom-containing vinyl monomer such as 2-(meth)acryloyloxyethyl acid phosphate, etc., according to a conventional method. What is called ``Unexamined Patent Publication @57-3''
Examples include fluorine-containing copolymer polyols having hydroxyl groups that react with polyisocyanates, such as those disclosed in Japanese Patent No. 4107.

Examples of non-yellowing polyisocyanates include aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexane diisocyanate; isophorone diisocyanate, methylcyclohexane-2,4-(or 2.6)-diisocyanate), and 4,4'-methylenebis( alicyclic diisocyanates such as cyclohexyl isocyanate) and 1,3-di(isocyanatomethyl)cyclohexane; each of these diisocyanates and polyhydric alcohols such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, and trimethylolpropane; A low molecular weight polyester resin that develops functional groups that react with isocyanate groups (
(including an oil-modified type), an adduct with water, etc., a billet form, or a (co)polymer (including an oligomer) of the above-mentioned diisocyanates.

The blending ratio of polyol and polyisocyanate is OH/NG
O-110.5 to 1/1.5 (equivalent), especially OH/NG
A range of O-110.8 to 1/1.2 is preferred.

In order to improve the drying properties of the non-yellowing type urethane paint that can be used in the present invention, tin octylate, dibutyltin dilaurate, diazabicycloundecene,
A conventional amount of a known urethanization reaction accelerator such as motuptil phosphate or monobutyl phthalate may be added to improve adhesion, drying properties, thinner resistance, gasoline resistance, flexibility, texture, etc. Other resins such as nitrified cotton, cellulose compounds such as cellulose acetate butyrate, various plasticizers such as dibutyl phthalate, polyester resins (including oil-modified ones), other acrylic resins, etc. may also be used for improvement. "Tinuvin 328" and "Tinuvin 770J" can be used to further improve weather resistance.
A conventional amount of an ultraviolet absorber such as (Chill Geigy product) may be added. Further, conventional amounts of known paint additives such as leveling agents and antifoaming agents can be used.

The thus obtained non-yellowing urethane paint is applied to the marble surface to a film thickness of approximately 5 to 70 μm (when dry), and the curing conditions are room temperature drying or 50 to 9
Forced drying at about 0°C is common, and in some cases a vepocure system in which urethane is cured in an atmosphere of an amine compound can also be used. Recommended painting methods include spray painting, curtain flow painting, roll painting, and brush painting.

〔Effect of the invention〕

Natural marble coated with non-yellowing urethane paint as in the present invention has extremely excellent cement resistance, weather resistance, and abrasion resistance, so it is resistant to staining, discoloration, corrosion, abrasion, etc.
It also has a glossy appearance without the need for final polishing (puff finish).

〔Example〕

Next, the present invention will be explained with reference to Examples and Comparative Examples, but the present invention is not limited thereby.

Examples 1 to 5, Comparative Examples Paints having the composition shown in Table 1 were prepared, and toluene/
A mixed solvent of butyl acetate-50150 (weight ratio) was prepared in a round 4 Ford cup for 15 seconds, and then this mixture was heated to 75WX 75. , x 20m (thickness) Yugoslavian Xivec was coated to a film thickness of 45 to 50 μm (dry), baked at 60°C for 40 minutes, and then left at room temperature for 7 days. For comparison, similar physical property tests were conducted on unpainted Sivec.

(Note) 1) Acrylic polyol manufactured by Dainippon Ink Chemical ■; nonvolatile content (NV) = 50%, hydroxyl value -502) Same as above
Acrylic polyol made by Co., Ltd.; NV = 55%, hydroxyl value = 30 3) Same as above Acrylic polyol made by Co., Ltd.; NV =
60%, hydroxyl value = 55 4) Fluororesin manufactured by Asahi Glass ■, NV = 60%, hydroxyl value -31,5 5) Polyisoane anate manufactured by Dainippon Ink Chemical ■; N
V = 75%, NCO content = 12.5% by weight 6) Resident Bayer Urethane special polyisocyanate; NV-7
5%, NGO content -16.5% by weight 7) Polyisocyanate manufactured by Nippon Polyurethane; NV-100%, NG
O content = 21.3% by weight 8) "Tinuvin""Irganoxco" Chill Geigy product 9) Appearance visually judged 10) Goban adhesion test by peeling cellophane tape 11) 75., x 75 A cylinder (diameter 5) fixed to a marble board of 20 mm (thickness) with a silicone sealant.
0ta x height 100m) with mortar cement at a height of 8
Pour to 0 crane and cure for 3 days, then cover with 5fi thick water and observe the leaching state of scum on the back side of the marble 12) Evaluate with a taper abrasion tester (load 500g, 100 rotations, paper C5-1) 13 ) Visually determined

Claims (1)

[Claims] Natural marble made by painting the surface of the stone with non-yellowing urethane paint.