JPH07102241A - Sealer for porous inorganic substrate - Google Patents

Abstract

PURPOSE:To obtain a water-base sealer which has no danger of fire or risk of environmental pollution and which is excellent in water resistance, adhesive properties, etc., and long durable. CONSTITUTION:This sealer contains, as the binder, a mixture comprising 30-85wt.% acrylic emulsion resin and 70-15wt.% lithium silicate represented by the general formula: Li2O.SiO2 (wherein n is 3-8).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealer for an inorganic porous base material, which has excellent adhesion to a base material and a top coating film, water resistance, frost damage resistance and the like.

[0002]

2. Description of the Related Art Ceramic siding base materials such as flexible boards, calcium silicate boards, gypsum slag perlite boards, wood chip cement boards, precast concrete boards and ALC boards, and inorganic porous base materials such as moctal and concrete base materials are A paint is usually applied on the surface in order to have a beautiful appearance and to improve water resistance. However, when the paint is directly applied to the surface, the base material is porous, so that a smooth coating film cannot be obtained, and the water resistance and the adhesion are likely to be poor. Conventionally, it is common to interpose a sealer layer before coating a coating on an inorganic porous substrate (hereinafter simply referred to as a porous substrate).

As a sealer, various resins such as low molecular weight urethane resin type, epoxy resin type, acrylic resin type, chlorinated rubber type and silane type resins of Comparative Examples are dispersed or dissolved in an organic solvent, and if necessary, a coloring pigment, Organic solvent-based sealers mixed with extender pigments, water-soluble sealers in which various water-soluble resins are dissolved in water or various water-dispersible resins are dispersed in water, and further colored pigments, extender pigments, etc. are added Known as a typical sealer.

[0004]

However, the above-mentioned organic solvent-based sealer has problems such as fire risk and environmental pollution. Therefore, the water-based sealer has been attracting attention, but the one using a water-soluble resin has poor water resistance, while the one using a water-dispersible resin has good water resistance, but is a porous substrate. There was a problem that the adhesiveness was inferior because the impregnation property into the was poor.

In view of the above situation, the present inventors have developed a water-based sealer which is free from fire risk and environmental pollution, and has long-term durability which is excellent in water resistance and adhesion. As a result of intensive studies, the present invention has been achieved.

[0006]

Means for Solving the Problems That is, the present invention comprises: (i) 30 to 85% by weight of an acrylic emulsion resin; and (ii) a general formula Li ₂ O.nSiO ₂ (where n is a numerical value of 3 to 8). And a sealer for an inorganic porous substrate using a mixture of 70 to 15% by weight of lithium silicate as a binder.

The present invention will be described in detail below. As the porous base material as referred to in the present invention, the above-mentioned ones are mentioned as typical ones, and particularly suitable for the porous base material having an apparent specific gravity of 1.3 or less and the porous base material including the cut portion. I can. The sealer of the present invention has a binder composed of an acrylic emulsion resin and lithium silicate described below and water as essential components, and if necessary, various coloring pigments, extender pigments,
It is composed of a small amount of an organic solvent or a dispersant, a thickener, an antifoaming agent, an antiseptic, an antifungal agent, a film forming agent, and various additives such as a curing catalyst.

The acrylic emulsion resin has acrylic acid or methacrylic acid (both are expressed as (meth) acrylic acid). ] C1-C8 alkyl ester,
Specifically, monomers such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, and octyl (meth) acrylate are used alone. Polymers or copolymers or these monomers and other copolymerizable monomers such as (meth) acrylic acid, itaconic acid,
Functional monomers such as fumaric acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide; styrene, vinyltoluene, ( (Meth) acrylonitrile, vinyl chloride, a copolymer with a non-functional monomer such as butadiene, and the like, these are appropriately combined with the above monomers,
Typical examples include those obtained by emulsion polymerization in the presence of an emulsifier according to a conventional method, or those obtained by partially using a carboxyl group-containing monomer as the above-mentioned monomer and neutralizing after emulsion polymerization.

These acrylic emulsion resins preferably have a molecular weight of about 50,000 to 300,000, preferably 100,000 to 200,000, and a minimum film forming temperature of about 30 ° C. or more in order to obtain a film tensile strength of 60 kg / cm or more. Further, the particle diameter of the acrylic emulsion resin is 0.01 to 1 μm, and in particular, the colloidal emulsion resin having a particle diameter of 0.01 to 0.08 μm is preferable from the viewpoint of impregnation into the porous substrate. The acrylic emulsion resin may be a normal dry type or a baking type, and a self-crosslinking type resin in which zinc oxide, a metal complex salt, a hydrazide compound or the like is used in combination is also usable.

As the lithium silicate, one having a molar ratio of silicic acid to lithium of 3 to 8 is used as shown in the water-soluble general formula. If the molar ratio is smaller than the above range, the water resistance is poor, whereas if it is larger than the above range, the stability and impact resistance of the sealer are deteriorated, and therefore both are not preferable. It should be noted that the one using potassium silicate, sodium silicate, or aluminum silicate instead of lithium silicate is not suitable in the present invention because either the adhesion to the substrate or the water resistance is poor.

Since the binder used in the sealer of the present invention also uses a mixture of the acrylic emulsion resin and lithium silicate, the synergistic effect of the two, that is, the adhesion of the acrylic emulsion resin to the top coating film and the water resistance. And the like, and the effect of improving the adhesion to the substrate due to the ease of impregnating the substrate with lithium silicate, etc., and an excellent sealer layer is formed.

The mixing ratio (solid content) of the acrylic emulsion resin and the lithium silicate is preferably 30 to 85:70 to 15 in order to exert the above effects, and is preferably (4).
0 to 80:60 to 20) (weight basis). When the amount of acrylic emulsion resin is more than the above range, the impregnation property into the porous substrate is lowered, and as a result, the adhesion to the substrate is deteriorated, while when it is less than the above range, the lithium silicate is relatively increased. In particular, both of them are not preferable because the adhesion to the organic top coating composition is deteriorated.

The solid content of the sealer of the present invention during coating is 1
5 to 60% by weight, preferably 20 to 50% by weight is suitable, and the amount of the binder in the solid content is suitably 50 to 100% by weight. As a method for coating the sealer on the porous substrate, known coating means such as air spray, airless spray, shower coat, roll coat, flow coat, and brush can be adopted, and the coating amount (Wet amount) is 30 to 180 g / m. ² , preferably 50 to 130 g / m ² , and after coating, it is naturally dried or forcedly dried at a temperature of 60 to 130 ° C.
The sealer-coated porous substrate is finished by coating with various known topcoat paints such as acrylic resin emulsion paints, if necessary.

[0014]

Since the sealer of the present invention uses water as a diluent, there is no risk of fire caused by an organic solvent, environmental pollution, etc., and it can be omitted. Further, since a binder composed of an acrylic emulsion resin and lithium silicate is used, a synergistic effect between the two enables good interlayer adhesion to both the porous substrate and the top coating film. Further, it becomes possible to form a sealer layer having excellent water resistance and frost damage resistance.

Therefore, the sealer of the present invention can be suitably applied to various kinds of porous substrates for new coating and repair coating.

[0016]

EXAMPLES The present invention will now be described in more detail by way of examples. In the examples, "parts" and "%" are shown by weight. Examples 1 to 3 and Comparative Examples 1 to 3 The components shown in Table 1 were mixed and dispersed to prepare a sealer.

[0017]

[Table 1]

Note 1) Copolymer emulsion of methyl methacrylate / butyl acrylate = 53/47 (solid content 41%, particle size 0.03 to 0.05 μm, film tensile strength 100 kg / cm, minimum film forming temperature 41 ° C.) Note 2) "Acronal YJ-1850D""Product name of Mitsubishi Yuka Birdish Co., Ltd." (solid content 41%, particle size 0.03)
~ 0.05μm, film tensile strength 100kg / cm, minimum film forming temperature 50 ℃) Note 3) Methyl methacrylate / butyl acrylate = 7
0/30 copolymer emulsion (solid content 45%, particle size 0.04 to 0.06 μm, film tensile strength 105 kg /
cm, minimum film forming temperature 53 ° C) Note 4) SiO ₂ : 20%, Li ₂ O: 2.9%, n value: 3.5 Note 5) SiO ₂ : 20%, Li ₂ O: 2.2%, n value 4.5 Note 6) SiO ₂ : 28 to 30%, K ₂ O: 17 to 18%, n value
2.5-2.7 Note 7) Mixture consisting of dispersant, thickener, film forming aid, defoaming agent and preservative Reference Examples 1 to 3 Pulp-mixed gypsum slag cement board with an apparent specific gravity of 1.10. (According to the molding method) is cut, and the sealers of Example 1, Comparative Example 1 and Comparative Example 3 are airless sprayed on a plate material having grooves with a width of 3 cm and a depth of 3 mm at intervals of 10 cm.
g / m ² (wet amount) was applied and dried at 120 ° C. for 3 minutes. Next, the top coating composition shown in Table 1 was applied by airless spray at 80 g / m ² (wet amount) and dried at 120 ° C. for 10 minutes. After leaving the obtained coating material at room temperature for 7 days, adhesion, water resistance and frost damage resistance tests were conducted, and the results are shown in Table 2.
It was shown to. Reference Examples 4 to 5 A gypsum slag perlite plate having an apparent specific gravity of 1.05 (by the papermaking method) was cut in the same manner as in Reference Example 1 and the sealer of Example 2 and Comparative Example 2 was airless sprayed to 70 g.
/ M ² (wet amount) was applied and dried at 120 ° C. for 4 minutes.
Then, a top coating composition was applied in the same manner as in Reference Example 1 and the same test was conducted. Reference Examples 6 to 7 The sealer of Example 3 and Reference Example 1 was applied to a calcium silicate plate (papermaking method) having an apparent specific gravity of 1.15 by airless spraying 80.
After applying g / m ² (wet amount) and pressing the roll, 120 ℃
It was dried for 1 minute. Next, the top coating composition shown in Table 1 was applied with a coating sponge roll coater at 50 g / m ² (wet amount), dried at 120 ° C. for 10 minutes, and the same test as in Reference Example 1 was performed.

[0019]

[Table 2]

Note 8) Cellulophane tape peeling test for 4 mm goggles of initial coating material Note 9) Adhesion test after immersion in water (20 ° C) for 20 days Note 10) Freezing in water at -20 ° C for 16 hours → 20 ° C for 8 hours Adhesion test after 50 cycles of dissolution in water ⊚: 25/25, ∘: 22/25 to 24/25, Δ: 1
5/25 to 21/25, x: 14/25> As is clear from Table 2, Reference Examples 1, 4, and 6 using the sealer of the present invention have excellent adhesion, water resistance, and frost damage resistance. Was there.

On the other hand, in Reference Examples 2 and 7 in which the sealer containing no lithium silicate (Comparative Example 1) was used, the adhesion between the base material and the sealer was particularly poor after the freeze-thaw test.
Further, in Reference Example 5 using a sealer containing no acrylic emulsion resin (Comparative Example 2), the adhesion between the sealer and the top coating film was poor. Reference Example 3 using a sealer (comparative example 3) using potassium silicate instead of lithium silicate had poor water resistance and adhesion after freeze-thaw test.

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[Procedure amendment]

[Submission date] December 18, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art Ceramic siding base materials such as flexible boards, calcium silicate boards, gypsum slag bar light boards, wood chip cement boards, precast concrete boards and ALC boards, and inorganic porous base materials such as mortar and concrete base materials , A paint is usually applied on the surface to give it a beautiful appearance and to improve water resistance. However, when the paint is directly applied to the surface, the base material is porous, so that a smooth coating film cannot be obtained, and the water resistance and the adhesion are likely to be poor. Conventionally, it is common to interpose a sealer layer before coating a coating on an inorganic porous substrate (hereinafter simply referred to as a porous substrate).

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

As the sealer, various resins having relatively low molecular weight such as urethane resin, epoxy resin, acrylic resin, chlorinated rubber and silane are dispersed or dissolved in an organic solvent, and if necessary, a coloring pigment, Organic solvent-based sealers mixed with extender pigments, water-soluble sealers in which various water-soluble resins are dissolved in water or various water-dispersible resins are dispersed in water, and further colored pigments, extender pigments, etc. are added Known as a typical sealer.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

The present invention will be described in detail below. The porous base material as referred to in the present invention includes those mentioned above as typical ones, and is particularly preferably applied to a porous base material having an apparent specific gravity of 1.3 or less and a porous base material including a cut portion thereof. I can. The sealer of the present invention has a binder consisting of an acrylic emulsion resin and lithium silicate described below and water as essential components, and if necessary, various coloring pigments, extender pigments, small amounts of organic solvents or dispersants, thickeners, Antifoam,
It is made up of various additives such as antiseptics, antifungal agents, film forming aids , curing catalysts and the like.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

As the lithium silicate, one having a molar ratio of silicic acid to lithium of 3 to 8 is used as shown in the water-soluble general formula. If the molar ratio is smaller than the above range, the water resistance is poor, whereas if it is larger than the above range, the stability and impact resistance of the sealer are deteriorated, and therefore both are not preferable. In addition, instead of lithium silicate, potassium silicate, sodium silicate , silicate
Those using monium are not suitable in the present invention because they have poor adhesion or water resistance to the substrate.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

Since the binder used in the sealer of the present invention also uses a mixture of the acrylic emulsion resin and lithium silicate, the synergistic effect of the two, that is, the adhesion of the acrylic emulsion resin to the top coating film and the water resistance. And the like, and the effect of improving the adhesion to the base material due to the ease of impregnating the base material with lithium silicate and the like, thereby forming an excellent sealer layer.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

[0014]

Since the sealer of the present invention uses water as a diluent, there is no risk of fire due to organic solvents, environmental pollution, etc., and resource saving is possible. Further, since a binder composed of acrylic emulsion resin and lithium silicate is used, the interlayer adhesion to both the porous substrate and the top coating film is good due to the synergistic effect of both. Further, it becomes possible to form a sealer layer having excellent water resistance and frost damage resistance.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

Note 1) Copolymer emulsion of methyl methacrylate / butyl acrylate = 53/47 (solid content 41%, particle size 0.03 to 0.05 μm, film tensile strength 100 kg / cm, minimum film forming temperature 41 ° C.) Note 2) "Acronal YJ-1850D""trade name of Mitsubishi Yuka Birdish Co., Ltd." (solid content 41%, particle size 0.0
3 to 0.05 μm, film tensile strength 100 kg / c
m, minimum film forming temperature 50 ° C) Note 3) Methyl methacrylate / butyl acrylate = 7
0/30 copolymer emulsion (solid content 45%, particle size 0.04 to 0.06 μm, film tensile strength 105
(kg / cm, minimum film forming temperature 53 ° C.) Note 4) SiO ₂ : 20%, Li ₂ O: 2.9%, n value
3.5 Note 5) SiO ₂ : 20%, Li ₂ O: 2.2%, n value
4.5 Note 6) SiO ₂ : 28 to 30%, K ₂ O: 17 to 18
%, N value 2.5 to 2.7 Note 7) Mixture of dispersant, thickener, film forming aid, defoaming agent and preservative Reference Examples 1 to 3 Pulp-mixed gypsum slag with apparent specific gravity of 1.10. A cement plate (by extrusion molding method) was cut, and a sealer of Example 1, Comparative Example 1 and Comparative Example 3 was applied to the plate material having grooves of 3 cm in width and 3 mm in depth at 10 cm intervals by airless spray at 80 g / m ² (wet amount) was applied and dried at 120 ° C. for 3 minutes. Then, the top coating composition shown in Table 1 was applied by airless spray at 80 g / m ² (wet amount), and 120
C., and dried for 10 minutes. The coating material thus obtained was allowed to stand at room temperature for 7 days and then tested for adhesion, water resistance and frost damage resistance. The results are shown in Table 2. Reference Examples 4 to 5 A gypsum slag perlite plate (by papermaking method) having an apparent specific gravity of 1.05 was machined in the same manner as in Reference Example 1 and the sealer of Example 2 and Comparative Example 2 was airless sprayed to 70 g.
/ M ² (wet amount) was applied and dried at 120 ° C. for 4 minutes. Then, a top coating composition was applied in the same manner as in Reference Example 1 and the same test was conducted. Reference Examples 6 to 7 The calcium silicate plate (papermaking method) having an apparent specific gravity of 1.15 and the sealer of Example 3 and Reference Example 1 were applied by airless spraying 8
After applying 0 g / m ² (wet amount) and pressing the roll, 1
It was dried at 20 ° C. for 1 minute. Next, the top coating composition shown in Table 1 was applied to a sponge roll coater at 50 g / m ² (wet amount).
The composition was applied, dried at 120 ° C. for 10 minutes, and the same test as in Reference Example 1 was performed.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

Note 8) Cellulophane tape peeling test for 4 mm goggles of initial coating material Note 9) Adhesion test after immersion in water (20 ° C) for 20 days Note 10) Freezing in water at -20 ° C for 16 hours → 20 ° C for 8 hours Adhesion test after 50 cycles of melting in water ⊚: 25/25, ∘: 22/25 to 24/25, Δ: 1
5/25 to 21/25, x: 14/25> As is clear from Table 2, Reference Examples 1, 4, and 6 using the sealer of the present invention have excellent adhesion, water resistance, and frost damage resistance. Was there.

Claims (1)

[Claims] 1. (i) Acrylic emulsion resin 30
~ 85 wt%, (ii) General formula Li ₂ O · nSiO ₂ (where n is a numerical value of 3 to 8)
Lithium silicate
A sealer for an inorganic porous substrate, which uses a mixture of 70 to 15% by weight as a binder.