JPH0648864A - Surface treatment of natural stone - Google Patents

Abstract

PURPOSE:To tightly and surely adhere a planer ceramic layer excellent in resistances against water, contamination, heat and scratching by applying a compsn. essentially consisting of specified silane, silicate, vinyl resin, Al compd., etc. CONSTITUTION:An undercoating material S1 and an overcoating material S2 are used. These coating materials essentially consist of a partially condensed product of a specified organoalkoxysilane, tetraalkylsilicate, silyl group-contg. vinyl resin containing silyl groups in the polymer molecule and having Si atoms coupled with hydrolytic groups in the end of the molecule or in the side chains, and an Al compd. and/or partially hydrolyzed compd. The undercoating material S1 containing 60-180 pts.wt. of the silyl group-contg. vinyl resin to 100 pts.wt. of the organoalkoxysilane is applied on the surface 1a of natural stone material 1 to form an undercoating layer 2. Then, after curing, the layer 2 is polished so that only the embedded part 4 in the under-surface area 3 remains. Then the polished surface is coated with the overcoating material S2 containing 10-60 pts.wt. of the silyl group-contg. vinyl resin to 100 pts.wt. organoalkoxysilane to form a ceramic layer 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment method for natural stone materials.

[0002]

2. Description of the Related Art Natural stone materials such as marble and granite are widely favored for their design, texture, and high quality, and they are used as building materials for interiors and exteriors, table tops, kitchen tops, vanity tops, bathroom walls, floors. Widely used for etc.

[0003]

However, natural stone materials are porous and have cracks, cracks, etc. depending on the type of stone, and are easily penetrated by water or oil and easily contaminated.

Therefore, in the application around water, many stains and stains are generated, and once they are generated, the stains and the like cannot be removed.

Further, when the natural stone material is marble, its main component is calcium carbonate, which is weak against acid, and when used as an exterior material, it has a drawback that it is easily eroded by acid rain.

Therefore, a surface treatment for coating natural stone with a coating layer of a silane-based water absorption inhibitor, a silicone-based resin, a fluororesin, a urethane-based resin, an acrylic-based resin or the like has come to be performed.

However, even when such a surface treatment is performed, the desired water resistance and antifouling property are obtained, and at the same time,
The heat resistance, the abrasion resistance, and the adhesion to the natural stone were not sufficiently satisfied.

Further, the natural stone material has many small holes and cracks on its surface. When the above-mentioned coating layer is formed in this state, irregularities are formed on the front surface of the coating layer due to the small holes and cracks. There is also the drawback that it will be done.

Therefore, it has become necessary to fill small holes, cracks, etc. on the surface of natural stone with resin.

However, the resin to be filled is an epoxy resin or the like, which is not transparent and requires color matching for each natural stone material, and further impairs the original beauty of the natural stone material.

A method has also been developed in which the filling of holes and the antifouling treatment are simultaneously performed with an ester resin, but in this case, multiple coatings (5 to 10 times) are required, and each coating is performed at room temperature. Since it has to be cured, the workability is poor and the cost is high.

Therefore, according to the present invention, it is possible to surely adhere a flat ceramic layer on the surface of a natural stone material, the surface of which is not uneven, and the natural stone material is water-resistant and stain-proof. It is an object of the present invention to provide a surface treatment method for natural stone which is excellent in heat resistance, heat resistance and abrasion resistance and does not impair the original beauty of stone.

[0013]

In order to achieve the above-mentioned object, a surface treatment method for a natural stone material according to the present invention comprises a general formula RSi (OR ¹ ) ₃ (wherein R represents a carbon number of 1 to 8). Organic group, R ¹ is an alkyl group having 1 to 5 carbon atoms or 1 to 5 carbon atoms
4 represents an acyl group) and a tetraalkyl represented by the general formula Si (OR ² ) ₄ (wherein R ² represents an alkyl group having 1 to 4 carbon atoms). A silicate, a silyl group-containing vinyl resin having at least one silyl group having a silicon atom bound to a hydrolyzable group at a terminal or a side chain in a polymer molecule, and a general formula Al (OR ³ ) _n [OR (R ⁴ )
= CHCOR ⁵ ] _3-n (wherein R ³ and R ⁴ are alkyl groups, R ⁵ is an alkyl group or an alkoxy group, and n is 0 to
An aluminum compound represented by the formula 3) and at least one selected from the group of partial hydrolysates of the aluminum compound, and a ceramic layer comprising a coating composition containing as a main component a surface of a natural stone material. A method for surface treatment of natural stone to be formed, wherein the silyl group-containing vinyl resin is 60 to 100 parts by weight of organoalkoxysilane.
180 parts by weight of the coating composition as an undercoating agent, applied to the surface of the natural stone material, small holes on the surface, an undercoating layer having an embedded portion embedded in a non-planar portion consisting of cracks,
Then, after the undercoat layer is cured, the undercoat layer is polished until the surface of the natural stone is exposed, leaving the buried portion, and then the silyl group-containing vinyl-based resin is 100 parts by weight of organoalkoxysilane. 10 to 60 parts by weight of the coating composition as a topcoating agent is applied to the polished surface of the natural stone to form a ceramic layer on the surface of the natural stone.

[0014]

[Function] When the undercoating agent is applied to the surface of the natural stone to form the undercoating layer, the buried portion of the undercoating layer fills the non-planar portion of the surface of the natural stone with small holes and cracks. It

Thereafter, the undercoat layer is polished, but in this case, the portions other than the buried portion are removed. That is, the polished surface is flat and has no uneven portion.

When a top coat is applied to the polished surface, a ceramic layer is formed on the surface of the natural stone.

Therefore, the front surface of the ceramic layer has a flat surface with no irregularities, and the undercoating agent and the topcoating agent contain the same silyl group-containing vinyl resin. The adhesiveness is good, the transparency is high, and the appearance of the natural stone material is not impaired.

[0018]

The present invention will be described in detail below with reference to the drawings illustrating the embodiments.

First, as shown in FIG. 2, the surface 1a of the natural stone material 1 is cleaned and degreased with water, alcohol or a ketone solvent to bring it into a clean state.

Next, an undercoat agent S ₁ is applied on the surface 1a as shown in FIG. 3 to form an undercoat layer 2.

As a coating method, a brush coating, a spatula coating, a flow coater, a bar coater, a roll coater, an air spray, an airless spray, or the like can be used.

Therefore, the undercoating agent S ₁ penetrates into the non-planar portion 3 such as small holes and cracks on the surface 1a, and the undercoating layer 2 thus formed has the embedded portion 4 embedded in the non-planar portion 3. To be done.

The undercoating agent S ₁ is selected from the group consisting of a partial condensate of organoalkoxysilane, a tetraalkyl silicate, a vinyl resin containing a silyl group, an aluminum compound and a partial hydrolyzate of the aluminum compound. And at least one of the following.

In addition, the primer S ₁ contains 60 to 180 parts by weight of the silyl group-containing vinyl resin with respect to 100 parts by weight of the organoalkoxysilane.

Thus, a partial condensate of an organoalkoxysilane has the general formula RSi (OR ¹ ) ₃ (wherein R is an organic group having 1 to 8 carbon atoms, R ¹ is an alkyl group having 1 to 5 carbon atoms, or It represents an acyl group having 1 to 4 carbon atoms).

The tetraalkyl silicate is represented by the general formula Si (OR ² ) ₄ (wherein R ² represents an alkyl group having 1 to 4 carbon atoms).

Further, the silyl group-containing vinyl resin has at least one silyl group having a silicon atom bonded to a hydrolyzable group at the terminal or side chain in the polymer molecule.

The aluminum compound has the general formula A
l (OR ³ ) _n [OR (R ⁴ ) = CHCOR ⁵ ]
_3-n (wherein R ³ and R ⁴ are alkyl groups, R ⁵ is an alkyl group or an alkoxy group, and n is an integer of 0 to 3)
It is represented by.

Therefore, the above-described undercoating agent S ₁ has a viscosity of 50 to 150 cps, and when this undercoating agent S ₁ is applied to the surface 1a, the undercoating agent S ₁ is applied to the non-planar portion 3 of the surface 1a. Surely penetrates. Note that the undercoating agent S ₁ does not penetrate into the back surface 1b side of the crack 3b reaching the back surface 1b of the natural stone material 1 as shown in the figure.

However, when the silyl group-containing vinyl resin is 180 parts by weight or more with respect to 100 parts by weight of the organoalkoxysilane, the viscosity becomes 150 cps or more, and the reaction becomes a slow substance, which often occurs in the subsequent curing step. However, if the silyl group-containing vinyl resin is 60 parts by weight or less, the viscosity is 50 cps.
Below, the undercoating agent S ₁ that has penetrated into the cracks 3b becomes the back surface 1
It reaches up to b and the effect of the sealing agent disappears.

Next, dehydration and dealcoholization are carried out to 100
The undercoat layer 2 is cured by heating at 220 ° C (preferably 140 to 200 ° C) for 10 to 60 minutes.

After curing, the undercoat layer 2 is polished. In this case, as shown in FIG. 4, polishing is performed until the surface 1a is exposed.

Therefore, in the undercoat layer 2, only the embedded portion 4 filling the non-planar portion 3 remains, and the polishing surface 5 thereof has a planar shape.

Further, since dust is generated during polishing, after polishing, the polishing surface 5 is cleaned and degreased with water, alcohol, a ketone solvent or the like to bring it into a clean state.

Incidentally, the polishing surface 5 is finished to about # 200 to # 1000, preferably about # 400 to # 800 (that is, a slightly rough finish), but it is a mirror finish such as a main polishing finish generally called a stone material. May be.

The natural stone material 1 generally has a surface 1
Since waxing is performed to polish a, the wax will be removed by this polishing.

Next, a top coat S ₂ is applied to the polishing surface 5 by air spray or airless spray to form a ceramic layer 6 as shown in FIG.

Thus, the overcoating agent S ₂ is the undercoating agent S ₁
Similarly to, a partial condensate of an organoalkoxysilane, a tetraalkyl silicate, a silyl group-containing vinyl resin, and at least one selected from the group consisting of an aluminum compound and a partial hydrolyzate of the aluminum compound, as a main component. Which is a coating composition.

Moreover, the top coat agent S ₂ contains 10 to 60 parts by weight of the silyl group-containing vinyl resin per 100 parts by weight of the organoalkoxysilane and has a viscosity of 10 to 50 cps.
It is said that

When applying the overcoat S ₂ , the polishing surface 5
Is in a clean state, the adhesion of the top coat agent S _{2 to} the stone material 1 is improved, and further, the contamination of the coating film due to dust, dirt, etc. of the natural stone material 1 can be prevented. Furthermore, polishing surface 5
Is polished in a slightly rough state, so that the overcoating agent S ₂ easily adheres to it.

Before applying the top coat S ₂ , the stone material 1
Wax surface 1a has been removed, topcoat S ₂
Repelling is prevented, and the adhesion with the stone material 1 is improved.

Next, after the application, the natural stone material 1 is held horizontally (hereinafter referred to as leveling).

That is, since the topcoat agent S ₂ has a viscosity of 10 to 50 cps as described above, it appropriately flows and forms a coating film having a uniform wall thickness.

When the viscosity is 50 cps or more, it becomes difficult to flow and a uniform coating film is not formed. On the contrary, when the viscosity is 10 cps or less, compatibility inside the coating composition is lost and cracks are likely to occur. Is.

The low-viscosity compound may be diluted with a solvent such as alcohol.

The thickness of the overcoating agent S ₂ formed is 10 to 100 μm, preferably 20 to 50 μm in the dry state.
It is about μm.

This is because if the thickness is less than 10 μm, it is difficult to prepare a uniform coating film and the durability is poor.
If it is above, it is difficult to produce a coating film having high hardness due to cracks, and if the wall thickness is too large, it becomes so-called "sticky", and the texture of the natural stone material 1 This is because the design may be impaired.

The spray pressure at the time of application is set so that the top coating agent S ₂ does not bounce after hitting the polishing surface 5, and is 3.0 kg / cm ² or less, preferably 1.0 to 2.0 kg / cm ^2. And

Therefore, the proportion of the main components formed by the partial condensate of organoalkoxysilane, the tetraalkyl silicate, and the silyl group-containing vinyl resin contained in the coating composition used is preferably 20 to 75%.

That is, if it is 20% or less, sufficient adhesion to the stone material 1 cannot be obtained, and the coating film cannot be made excellent in abrasion resistance, heat resistance and the like. If it is 75% or more, the range of the coating film thickness is limited to a narrow range, and although the coating film having high hardness can be obtained, the production of the coating film becomes difficult due to the generation of cracks due to the film strain.

At this time, it is preferable to use a solvent having a boiling point of 100 ° C. or higher as the viscosity adjusting solvent.

The method of applying the overcoat S ₂ is as follows.
Flow coaters, roll coaters, bar coaters, etc. can be used freely.

Next, after leveling for 1 to 15 minutes, it is conducted at 100 to 220 ° C. (preferably 140 to 200 ° C.) for 10 to 10 minutes.
After heating for 60 minutes, dehydration, dealcoholization,
The top coat S ₂ is hardened to form the ceramic layer 6 on the surface 1 a of the natural stone material 1.

By the way, as described above, since the solvent used has a boiling point of 100 ° C. or higher, when the solvent is heated, the overcoat S
_The solvent does not evaporate before the ₂ is cured, so that the surface of the coating film (ceramic layer 6) formed is not uneven and the appearance is not impaired.

That is, if the boiling point of the solvent is 100 ° C. or less, the solvent evaporates before curing and the surface uniformity and appearance of the ceramic layer 6 are impaired.

Depending on the stone type of the natural stone material 1, the water contained in the stone material evaporates into bubbles during heating,
Since the formed ceramic layer 6 is not uniform, a uniform coating film is formed by applying preheating at 50 ° C. or lower and evaporating the water inside the stone material before applying the overcoating agent S _2. be able to.

It is also preferable to add a pigment to the topcoat S ₂ to obtain a matte texture, depending on the intended use.

Further, it is possible to add an appropriate amount of additives generally used in paints such as an inhibitor for preventing the natural stone material 1 from dripping, an adhesion-imparting agent for improving adhesion, and an antifoaming agent.

Next, an experimental example will be shown.

Marble (Rosso Asiago) is used as the natural stone material 1, the surface of the marble is washed and degreased, and the surface of the marble is coated with the undercoating agent S ₁ brush shown in Table 1. At this time, the undercoating agent S is applied to the non-planar portion 3 such as the small holes 3a and the cracks 3b.
Make sure ₁ is fully filled. The thickness of the marble was 12 mm.

[0061]

[Table 1]

In Table 1, the reactive siloxane oligomer means a dimer type reactive siloxane oligomer having a functional group at one end of pentamethyldisiloxane or / and a dimer type having a functional group at both ends of tetramethyldisiloxane. It is a reactive siloxane oligomer.

This reactive siloxane oligomer is effective as a bonding promoter and a buffering agent between the components of the composition.

Next, the marble (natural stone material 1) coated with the undercoating agent S ₁ is heated at 150 ° C. for 30 minutes to cure the undercoating agent S ₁ to form the undercoat layer 2.

Then, the undercoat layer 2 is polished until the surface of the marble is exposed.

After polishing, cleaning and degreasing are performed, and the overcoating agent S ₂ shown in Table 1 is applied by spraying so that the film thickness after curing becomes 20 mm.

After coating, leveling was carried out for 5 minutes, then heating was carried out at 150 ° C. for 30 minutes, and the mixture was allowed to stand at room temperature for 24 hours.

Then, the obtained stone materials and the stone materials obtained in the comparative examples described below were evaluated.

As shown in Table 2, Comparative Example 1 is a natural stone material (marble) that does not use the overcoating agent S ₂ and the undercoating agent S ₁ , and the Comparative Example 2 is the undercoating agent S ₁ Is a stone material (marble) using the overcoating agent S ₂ of the composition shown in Table 2 without using the above, and Comparative Examples 3 to 6 show the undercoating agent S ₁ of the composition shown in Tables 2 and 3. It is a stone material (marble) using the above and the overcoating agent S ₂ .

[0070]

[Table 2]

[0071]

[Table 3]

In Comparative Examples 2 to 6, the undercoat layer 2 and the ceramic layer 6 were formed in the same manner as in the experimental example.

The evaluation was performed by the following method, and the results are shown in Table 4.

Appearance Evaluation It is observed visually whether or not the surface texture of the stone is impaired.

Evaluation of Adhesion (a) A steel ball having a diameter of 19.5 mm and a weight of 28.1 g was
It is allowed to fall freely on the ceramic layer 6 from the height of, and the state of the ceramic layer 6 due to the impact is observed.

(B) The ceramic layer 6 has 25 mm intervals of 2 mm.
Individual squares are cut, and then an adhesive tape is attached on the squares, then the adhesive tape is peeled off, and the peeled state is observed.

Evaluation of scratch resistance The hardness of the ceramic layer 6 is observed with a pencil having a hardness (7H).

Evaluation of heat resistance A plate heated to 200 ° C. is placed on the ceramic layer 6 and left for 20 minutes, then the plate is removed and the state of the ceramic layer 6 is observed.

Acid resistance evaluation Dilute hydrochloric acid to 10%, drop the diluted hydrochloric acid on the ceramic layer 6 with a pipette, leave it for 24 hours, and observe the state of the ceramic layer 6.

Evaluation of Contamination Resistance Oil-based magic (black), crayon (black), vinegar, soy sauce are applied or dropped onto a circular area having a diameter of 10 mm, and left standing for 24 hours, followed by washing with water or alcohol. The state of the ceramic layer 6 is observed.

Evaluation of sealing effect A solution prepared by dissolving a commercially available red acid dye in water at a concentration of 1 g / liter was dropped near the cracked portion of the marble and left for 2 hours as it was, followed by washing with water and cracking. Examine the state of penetration into the interior of the part and the back surface of the marble.

[0082]

[Table 4]

In addition to the above-mentioned evaluations, Table 4 also evaluated the good and bad curing times of the coating composition.

Therefore, it is understood that the stone material subjected to the surface treatment as in the experimental example is excellent in all evaluations.

[0085]

Since the present invention is configured as described above, it has the following effects.

A coating film (ceramic layer 6) having high hardness and excellent in abrasion resistance, water resistance, heat resistance, and stain resistance can be formed on the surface 1a of the natural stone material 1.

The natural stone material 1 having excellent adhesion of the ceramic layer 6 to the natural stone material 1 and surface-treated by this method is used as an interior material for kitchen tops, vanity tops, counter tops, and water areas. Even if it does, it can exhibit excellent antifouling property and waterproof property over a long period of time.

Since the undercoating agent S ₁ and the overcoating agent S ₂ contain the same type of silyl group-containing vinyl resin, they have good adhesion and are not easily peeled off.

The undercoating agent S ₁ and the overcoating agent S ₂ are highly transparent, and can maintain the natural beauty of the natural stone material 1 without impairing the appearance and design of the natural stone material 1.

All the operations can be completed in a relatively short time, and the workability is excellent and the processing can be performed at low cost.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of an essential part of a natural stone material in a state of being surface-treated by a surface treatment method for a natural stone material according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of a natural stone material before surface treatment.

FIG. 3 is an enlarged cross-sectional view of a main part with an undercoat layer formed.

FIG. 4 is an enlarged cross-sectional view of a main part in a state where an undercoat layer is polished.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Natural stone 1a Surface 2 Undercoat layer 3 Non-planar part 4 Buried part 5 Polished surface 6 Ceramic layer S ₁ Undercoat agent S ₂ Topcoat agent

Claims (1)

[Claims] 1. A general formula RSi (OR ¹ ) ₃ (wherein R represents an organic group having 1 to 8 carbon atoms, R ¹ represents an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms). ) A partial condensate of an organoalkoxysilane represented by the general formula Si
A tetraalkyl silicate represented by (OR ² ) ₄ (wherein R ² represents an alkyl group having 1 to 4 carbon atoms) and a silyl group having a silicon atom bonded to a hydrolyzable group at the terminal or side chain. A silyl group-containing vinyl resin having at least one polymer molecule, and a general formula Al (OR ³ )
Aluminum represented by _n [OR (R ⁴ ) = CHCOR ⁵ ] _3-n (wherein R ³ and R ⁴ are alkyl groups, R ⁵ is an alkyl group or an alkoxy group, and n is an integer of 0 to 3) A surface treatment method for a natural stone material, which comprises forming a ceramic layer composed of a coating composition containing at least one selected from the group consisting of a compound and a partial hydrolyzate of the aluminum compound on the surface of the natural stone material. As a primer, a coating composition in which the silyl group-containing vinyl resin is 60 to 180 parts by weight with respect to 100 parts by weight of organoalkoxysilane is applied to the surface of the natural stone material, and small pores on the surface, After forming an undercoat layer having an embedding portion embedded in a non-planar portion composed of cracks, etc., then, after the undercoat layer is cured, the undercoating is left until the surface of the natural stone is exposed leaving the embedding portion. Polish the layers, 10 After, silyl group-containing vinyl resin relative organoalkoxysilane 100 parts by weight of
A surface treatment method, characterized in that a coating composition of from about 60 parts by weight is applied as an overcoat to the polished surface of the natural stone to form a ceramic layer on the surface of the natural stone.