JPH10195337A - Primer for porous inorganic substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a primer improved in adhesion to a substrate and low- temperature curability and giving a primer coat having low shrinkage and elasticity by using a composition comprising a silyl-containing vinyl polymer and optionally a curing catalyst as the base. SOLUTION: One component of a composition which is the base of the primer, namely, a silyl-containing vinyl polymer the main chain of which substantially consists of a vinyl polymer chain and which has at least one hydrolyzable-group- bonded silicon-containing group (hereinbelow referred to as a hydrolyzable silyl group) at a terminal and/or in a side chain can give a primer excellent in durability and chemical resistance, etc., because its main chain substantially consists of a vinyl polymer. When a substrate is primed with this primer, and then finish-coated with e.g. acrylurethane, the adhesion is good. The hydrolyzable silyl groups forms a silanol group in the presence of water and forms a siloxane bond to improve the chemical resistance, etc., of the cured product. The silyl- containing vinyl polymer contains a vinyl polymer having a glass transition temperature (Tg) of 10 deg.C or below and a vinyl polymer having a Tg of 30 deg.C or above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a primer for a porous inorganic substrate. More specifically, the present invention relates to a primer for a porous inorganic substrate, which is based on a composition comprising a specific silyl group-containing vinyl polymer and a curing catalyst which may be contained.

[0002]

2. Description of the Related Art In recent years, a wide range of inorganic plate-like products for residential use has been developed from a cement extruded plate having a dense surface to a porous ALC.

In general, inorganic base materials such as inorganic plate-like materials have characteristics such as extremely high water absorption and strong alkalinity as compared with plastic base materials and the like. A method of coating and adjusting them and then performing a top coating is employed.

[0004] Among the primers used as described above, epoxy primers have relatively favorable properties.

[0005]

However, in the case of the epoxy-based primer, even those having a dense surface among inorganic base materials, the anchor effect to the base material is not sufficient and the adhesion is poor. Porous materials such as ALC are required to have low shrinkage or elasticity due to their fragile surface, but epoxy-based primers have the drawback that they are hard and cannot be said to have low shrinkage. doing.

In addition, primer coating is performed not only on a factory line but also on site, and is sometimes used at a low temperature of about 5 ° C. in winter. Therefore, the development of a primer having good low-temperature curability instead of an epoxy-based primer is desired.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the problems in the epoxy primer, and as a result, have completed the present invention.

That is, according to the present invention, the main chain is substantially composed of a vinyl polymer chain, and has at least one silicon-containing group bonded to a hydrolyzable group at a terminal and / or a side chain in one molecule. The present invention relates to a primer for a porous inorganic substrate, which is based on a composition comprising a silyl group-containing vinyl polymer and a curing catalyst which may be contained.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION As one component of a composition serving as a base of a primer of the present invention, a main chain is substantially composed of a vinyl polymer chain, and a terminal and / or a side chain is bonded to a hydrolyzable group. A silyl group-containing vinyl polymer having at least one silicon-containing group (hereinafter also referred to as a hydrolyzable silyl group) in one molecule is used.

The phrase that the main chain of the silyl group-containing vinyl polymer is substantially composed of a vinyl polymer chain means that the main chain is composed of a vinyl monomer unit such as a segment having a urethane bond or a siloxane bond in the main chain. Segments other than the segment, which means that the silyl group-containing vinyl polymer may be contained in a range that does not substantially impair the properties as a vinyl polymer, generally the atom of the atom constituting the main chain Even if a segment other than the segment comprising the vinyl monomer unit is contained in the range of about 50 atomic% or less, the characteristics as the vinyl polymer are not substantially impaired. As described above, since the main chain is substantially composed of a vinyl polymer, the primer is excellent in durability and chemical resistance. In addition, when a top coat such as acrylic urethane, acrylic silicon, or one-component acrylic is applied after the primer is applied, an effect that adhesion to the pliers is extremely good can be obtained.

The silicon-containing group bonded to the hydrolyzable group is a group containing a group capable of decomposing a group (X) bonded to a silicon atom (Si) into SiOH and XH by hydrolysis. Since such a group is contained in the silyl group-containing vinyl polymer, there is a feature that a silanol group is generated as long as water is present, and a siloxane bond can be generated.

The term "having at least one hydrolyzable silyl group in one molecule at the terminal and / or side chain of the silyl group-containing vinyl polymer" means that the polymer has a main chain terminal or side chain. Has at least one, preferably two or more hydrolyzable silyl groups per molecule.
Since it has at least one hydrolyzable silyl group per molecule, it has a high molecular weight or gels in the presence of moisture, generates a chemically stable siloxane bond, and improves the chemical resistance of the cured product. In addition, since the hydrolyzable silyl group has a good affinity for the inorganic base material and causes a crosslinking reaction due to the presence of moisture, the coating film has good adhesion to the inorganic base material, and the base material has a water absorbing property. Even if it is, the effect of not being adversely affected by the moisture and causing blistering or peeling is obtained.

The molecular weight of one hydrolyzable silyl group present in the silyl group-containing vinyl polymer is about 1,000 to 20,000 in terms of chemical resistance and adhesion. Is preferred.

The molecular weight of the silyl group-containing vinyl polymer is not particularly limited, and is usually from 2,000 to 30,0.
About 00, preferably 3,000 to 25,000
Some are used.

The glass transition point (Tg) of the polymer is not particularly limited. For example, when the Tg is lowered to 10 ° C. or less, the polymer has a characteristic of low shrinkage, and the Tg is lowered. When the temperature is as high as 30 ° C. or more, characteristics such as improvement of chemical resistance, water resistance, and reinforcing property of the base material arise.

The above-mentioned silyl group-containing vinyl polymer is obtained, for example, by copolymerization of a vinyl monomer and a hydrolyzable silyl group-containing monomer (hereinafter also referred to as a silyl group-containing monomer). The polymer may be polymerized so as to include a segment formed by a urethane bond or a siloxane bond in a part of the side chain.

The vinyl monomer is not particularly limited, and specific examples thereof include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl ( (Meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, polycarboxylic acid (maleic acid, fumaric acid, itaconic acid, etc.) and carbon number 1 Esters of unsaturated carboxylic acids such as diesters or half-esters with up to 20 linear or branched alcohols; styrene, α-methylstyrene, chlorostyrene, styrenesulfonic acid, 4-hydroxystyrene, vinyltoluene, etc. Aromatic hydrocarbon-based vinyl compounds; vinyl esters and allyl compounds such as vinyl acetate, vinyl propionate and diallyl phthalate; vinyl compounds containing nitrile groups such as (meth) acrylonitrile; vinyl compounds containing epoxy groups such as glycidyl (meth) acrylate; Amino group-containing vinyl compounds such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, vinylpyridine and aminoethyl vinyl ether; (meth) acrylamide, itaconic diamide, α-ethylacrylamide, methacrylamide, crotonamide, and maleic Acid diamide, fumaric acid diamide, N-vinylpyrrolidone, N-butoxymethyl (meth) acrylamide, N, N-dimethylacrylamide, N-methylacrylamide, acrylo Amide group-containing vinyl compounds such as rumorpholine; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl vinyl ether, N-methylol (meth) acrylamide, Alonix 5700 (Toa Gosei Chemical Industry Co., Ltd. )), Pla
ccel FA-1, Placel FA-4, Pl
hydroxyl-containing vinyl compounds such as accel FM-1 and Placel FM-4 (manufactured by Daicel Chemical Industries, Ltd.); (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, and salts thereof (alkali metal salts, ammonium salts) , Amine salts, etc.), unsaturated carboxylic acids such as maleic anhydride, acid anhydrides or salts thereof; vinyl methyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, isoprene, maleimide, N-vinylimidazole, vinyl sulfone And other vinyl compounds such as acids.

For example, when producing a silyl group-containing vinyl polymer having a low Tg such as 10 ° C. or lower, vinyl monomers such as butyl acrylate and 2-ethylhexyl (meth) acrylate are used. It is sufficient to use many vinyl monomers having a low Tg of the homopolymer, and when producing a high Tg having a Tg of 30 ° C. or more, the homopolymer such as methyl methacrylate, ethyl methacrylate, and styrene may be used. What is necessary is just to use many vinyl monomers with high Tg of a polymer.

The silyl group-containing monomer is not particularly limited, but specific examples thereof include, for example,

[0020]

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[0021]

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And the like.

The method for producing a silyl group-containing vinyl polymer from the silyl group-containing monomer and the vinyl monomer is not particularly limited.
No. 5, No. 57-36109, No. 58-157
No. 810, the solution polymerization using an azo radical initiator such as azobisisobutyronitrile facilitates handling of the initiator, and the polymerization reaction mixture is used as it is. Most preferred in terms of availability.

In the above production, n-dodecyl mercaptan, t-dodecyl mercaptan, n-butyl mercaptan, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane,
γ-mercaptopropylmethyldimethoxysilane, γ-
Mercaptopropylmethyldiethoxysilane, (CH ₃
O) ₃ Si—S—S—Si (OCH ₃ ) ₃ , (CH ₃ O) ₃
It is possible to adjust the molecular weight using a chain transfer agent such as _{Si-S 8 -S-Si (} OCH 3) 3.

In particular, when a chain transfer agent having a hydrolyzable silyl group in the molecule, for example, γ-mercaptopropyltrimethoxysilane, a hydrolyzable silyl group can be introduced into the terminal of the silyl group-containing vinyl polymer. .

Examples of the polymerization solvent include hydrocarbons (toluene, xylene, n-hexane, cyclohexane, etc.),
Acetates (eg, ethyl acetate, butyl acetate), alcohols (eg, methanol, ethanol, isopropanol, n-butanol), ethers (eg, ethyl cellosolve, butyl cellosolve, cellosolve acetate), ketones (methyl ethyl ketone, ethyl acetoacetate, acetylacetone) And non-reactive solvents such as diacetone alcohol, methyl isobutyl ketone, and acetone.

As the other component of the composition serving as the base of the primer of the present invention, the above-mentioned silyl group-containing vinyl polymer curing catalyst can be used. When the curing catalyst is used, the curing of the silyl group-containing vinyl polymer is accelerated as compared with when the curing catalyst is not used. In particular, even at a low temperature such as about 5 ° C. in winter, the curing is promoted, the crosslinking is easily formed, and the remarkable effect that the physical properties as a primer are rapidly exhibited is obtained.

Specific examples of the curing catalyst include organic tin compounds such as dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dilaurate, dioctyltin dimaleate, and tin octylate; phosphoric acid, monomethyl phosphate, monoethyl phosphate, and the like. Monobutyl phosphate, monooctyl phosphate, monodecyl phosphate, dimethyl phosphate,
Phosphate esters such as diethyl phosphate, dibutyl phosphate, dioctyl phosphate, and didecyl phosphate; alkyl titanates; organoaluminum; acidic compounds such as maleic acid and p-toluenesulfonic acid;
Hexylamine, di-2-ethylhexylamine, N,
Amines such as N-dimethyldodecylamine and dodecylamine; and alkaline compounds such as sodium hydroxide and potassium hydroxide. These curing catalysts may be used alone or in combination of two or more.

In the present invention, a composition serving as a base of the primer of the present invention is prepared from the silyl group-containing vinyl polymer and a curing catalyst which may be contained.

When a curing catalyst is used, the blending ratio of the silyl group-containing vinyl polymer and the curing catalyst in the composition varies depending on the type of the curing catalyst, etc., but cannot be specified unconditionally. Usually 100 parts by weight of the silyl group-containing vinyl polymer (100 parts by weight, hereinafter the same)
It is about 1 to 20 parts, preferably about 0.01 to 10 parts.

Further, the vinyl polymer containing a silyl group is
and a silyl group-containing vinyl polymer having a Tg of not more than 10 ° C.
When prepared to contain a silyl group-containing vinyl polymer having a Tg of 10 ° C. or less, particularly when applied to a porous inorganic base material such as ALC. Is preferable for improving characteristics such as low shrinkage, and a silyl group-containing vinyl polymer having a Tg of 30 ° C. or more is effective for improving reinforcing properties and water resistance, and is therefore preferable.

In this case, the use ratio of the silyl group-containing vinyl polymer having a Tg of 10 ° C. or lower to the silyl group-containing vinyl polymer having a Tg of 30 ° C. or higher is preferably about 1/9 to 8/2 by weight ratio.

Tg can be calculated by the following Fox equation.

[0034]

(Equation 1)

[0035] (wherein, Tg _i is Tg of i component, m _i represents the weight fraction of the i component.) Of the silyl group-containing vinyl polymer and consists also be curing catalyst be contained composition There is no particular limitation on the preparation method, and these may be mixed and prepared by an ordinary method. At this time, if necessary, hydrocarbons such as toluene and xylene; acetates such as butyl acetate; alcohols such as methanol and isopropanol; other ethers; and solvents such as ketones may be used.

The above composition may or may not contain a dehydrating agent. However, a dehydrating agent is blended in order to ensure stability that does not cause a problem even when used repeatedly and long-term stability. More preferred.

Specific examples of such a dehydrating agent include, for example, methyl orthoformate, ethyl orthoformate, methyl orthoacetate, ethyl orthoacetate, methyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane,
Hydrolyzable ester compounds such as vinyltrimethoxysilane, methyl silicate, and ethyl silicate are exemplified.

In the above description, the hydrolyzable ester compound is added at the time of preparing the composition. However, it may be added before the polymerization of the silyl group-containing vinyl polymer and also used as a solvent. And may be added when the primer of the present invention is prepared using this composition.

In the above composition, 1
One or more amines having a silicon-containing group bonded to at least one hydrolyzable group in the molecule (hereinafter also referred to as a silyl group-containing amine) can be contained. When the silyl group-containing amine is contained, for example, when the primer of the present invention is applied to an inorganic substrate having a dense surface such as a cement extruded plate, the adhesion is significantly improved. Can be obtained.

Specific examples of the silyl group-containing amine include, for example, γ-aminopropyltriethoxysilane,
a silane coupling agent such as γ-aminopropyltrimethoxysilane and N-β-aminoethyl-γ-aminopropyltrimethoxysilane; a silane coupling agent containing the amino group and ethylene oxide, butylene oxide,
Epichlorohydrin, epoxidized soybean oil, Epicort 828, Epicort 100 manufactured by Yuka Shell Epoxy Co., Ltd.
And a reaction product with an epoxy group-containing compound such as 1.

The amount of the silyl group-containing amine to be used is 1 to 100 parts of the silyl group-containing vinyl polymer.
About 500 parts are preferable, and about 5 to 200 parts is more preferable.

When the silyl group-containing amine is used in combination with the silyl group-containing vinyl polymer, when an alkyl alcohol having 1 to 4 carbon atoms is added, the composition in a container may be used repeatedly or for a long time. It is effective in stabilizing and preventing thickening and curing during storage. Specific examples of the alkyl alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol and sec-butanol. The amount of the alkyl alcohol to be used is preferably about 1 to 200 parts, more preferably about 5 to 100 parts, per 100 parts of the silyl group-containing amine.

In the above description, the silyl group-containing amine is blended at the time of preparing the composition, but it goes without saying that it may be blended at the time of preparing the primer of the present invention.

The composition used in the present invention prepared as described above generally has a resin concentration and a solution viscosity or a diluent viscosity suitable for a usual coating method, for example, brush coating or spray coating.

The primer of the present invention may be composed of only the above-mentioned composition. However, depending on the use, additives such as various pigments, dyes, anti-settling agents, leveling agents and the like; nitrocellulose, cellulose acetate butyrate, etc. Cellulose; alkyd resin, acrylic resin, vinyl chloride resin,
It may be prepared by adding a resin such as chlorinated propylene resin, chlorinated rubber and polyvinyl butyral. In particular, the addition of a pigment is effective in discriminating a portion coated with a primer.

For example, when the primer of the present invention is used as a primer for ALC, Tg is 10 ° C.
The ratio of the following silyl group-containing vinyl polymer and the silyl group-containing polymer having a Tg of 30 ° C. or more is 1/9 to 8/2 by weight ratio.
A primer blended to a certain degree is used as a base resin, and a primer such as a pigment colored with titanium oxide or the like is preferred from the viewpoint of improving the balance between low shrinkage, water resistance, and substrate reinforcement. When used as a primer for a cement extruded board, a silyl group-containing vinyl polymer 1
5 parts to 200 parts of a silyl group-containing amine are added to 00 parts, and the alkyl alcohol having 1 to 4 carbon atoms is added to
A primer prepared by adding 100 parts and coloring with titanium oxide or the like is preferred from the viewpoints of good adhesion to a substrate and good stability of viscosity during storage.

The primer of the present invention thus prepared generally has a resin solid content concentration suitable for a general coating method such as brush coating or spray coating, and a property of having a solution viscosity or a diluent viscosity. However, since these characteristics also vary depending on the type, amount, use, and the like of the components to be contained, it goes without saying that the characteristics may be out of the above range.

As described above, the primer of the present invention is coated on a porous inorganic substrate, and the water absorption of the porous inorganic substrate can be adjusted.

Since the primer of the present invention is based on a silyl group-containing vinyl polymer, the hydrolyzable silyl groups present in the polymer are hydrolyzed by moisture to form SiOH groups, and the porous inorganic substrate Because a strong bond is generated by reacting with the SiOH group present on the surface,
For example, the adhesiveness is good even for a dense material such as a cement extruded plate. In addition, since the hydrolysis of the hydrolyzable silyl group and the subsequent formation of siloxane bonds occur even at a low temperature such as about 5 ° C. in winter, for example, it cannot be used at a low temperature in a conventional epoxy primer. Is eliminated. Furthermore, since the main chain of the silyl group-containing vinyl polymer is composed of a soft main chain as compared to the epoxy resin, which is a vinyl polymer chain, even if it is applied to a porous and fragile surface such as ALC, the epoxy resin may be used. There is no problem such as in the case of a primer.

Specific examples of the porous inorganic substrate include:
For example, concrete, mortar, ALC, cellular concrete, brick, tile, slate, calcium silicate board, ceramics, tile, stone, wood chip cement board, cement extruded board, slag, gypsum cement board and the like can be mentioned.

The coating method of the primer of the present invention is not particularly limited, and the amount of the coating varies depending on the density, water absorption, etc. of the surface of the porous inorganic base material to be coated, the composition of the primer and the like, and cannot be specified unconditionally. However, for a substrate having a dense surface such as a cement extrusion molded plate, the solid content is generally about 10 to 100 g / m ² , and for a substrate having a porous surface such as ALC, the solid content is generally 50 to 200 g / m ^2.
It is about.

As described above, the porous inorganic base material coated with the primer of the present invention has excellent chemical resistance, reinforcing property, water resistance or adhesion to a topcoat material, and has excellent long-term durability. It can be suitably used as a material.

Next, the primer of the present invention will be described based on examples.

Synthesis Examples 1 to 3 360 g of xylene was charged into a reactor equipped with a stirrer, thermometer, nitrogen inlet tube, dropping funnel and cooling tube.
Heated. After that, 295 g of butyl acrylate,
579 g of methyl methacrylate, 117 g of γ-methacryloxypropyltrimethoxysilane, acrylamide 9
g and a solution of 8.5 g of azobisisobutyronitrile were continuously added to the reactor over 3 hours. After the addition of the monomer is completed, separately prepared azobisisobutyronitrile 2
g and a solution of 140 g of toluene were further added over 1 hour, and after 1 hour, polymerization was carried out to obtain a solution of a silyl group-containing vinyl resin (a-1).

The obtained resin solution has a nonvolatile concentration of 63%.
Met. The number average molecular weight of the resin measured by GPC was 15,000. PW of silyl group-containing vinyl resin
Titanium oxide (CR-90 manufactured by Ishihara Sangyo Co., Ltd.) was dispersed so as to have a C5% and a paint solid content concentration of 50% to prepare a white enamel. Dispersion was performed for 2 hours with a paint shaker using glass beads.

On the other hand, two kinds of hydrolyzable silyl group-containing vinyl resins were used in the same manner as in the above (Synthesis Example 1) except that the proportions of the monomer and azobisisobutyronitrile were changed as shown in Table 1. The solutions of (a-2) and (a-3) were obtained to prepare white enamel.

[0057]

[Table 1]

Synthesis Example 4 100 g of xylene, 80 g of methanol, and 56 g of Epicoat 828 (bisphenol A type epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd.) were placed in a reactor equipped with a stirrer, thermometer, nitrogen introduction tube, and cooling tube. , A1100 (γ-aminopropyltriethoxysilane manufactured by Nippon Unicar Co., Ltd.) 6
4 g were charged and reacted at room temperature for 30 minutes and then at 70 ° C. for 2 hours to obtain a silyl group-containing amine solution (a-4). (A-4) shows a reaction solution containing methanol or xylene.

When the obtained reaction product was analyzed by infrared spectroscopy, the absorption of the epoxy group at 910 cm ^-1 had disappeared.

Examples 1 to 4 and Comparative Example 1 Dioctyltin maleate was added to mortar boards prepared using standard sand of JIS R 5201 and 10 parts of the white enamel obtained in Synthesis Examples 1 to 3 in Table 2. Each of the added amount and the commercially available epoxy primer was coated so that the thickness after drying became about 10 μm, and was immediately cured at 5 ° C. Two hours later, the coated sample was completely immersed in water, stored at 5 ° C. for one day, and visually observed for any change in appearance. Table 2 shows the results.

[0061]

[Table 2]

Examples 5 to 9 and Comparative Example 2 The entire surface of an ALC plate (manufactured by Nippon Test Panel Industry Co., Ltd.)
The thickness of the primer shown in Table 3 after drying was about 10 μm.
After leaving the sample at room temperature for 7 days, the sample was completely immersed in water. The following freeze-thaw test was carried out, and the presence or absence of a change in appearance (generation of cracks) was visually observed. The number and weight change after 5 cycles were measured. Table 3 shows the results.

The freeze-thaw test was performed at -20 ° C. for 3 hours for 60 hours.
The cycle was performed at 3 ° C. for 3 hours.

[0064]

[Table 3]

Examples 10 to 13 and Comparative Example 3 Extruded cement board (trade name: Asrock, manufactured by Nozawa Co., Ltd.)
Then, a primer having a composition shown in Table 4 was applied so that the thickness after drying became about 10 μm, left at room temperature for 7 days, and then the sample was completely immersed in water. A freeze-thaw test was performed, and the occurrence of blisters or cracks was visually observed to determine the number of cycles in which these occurred. At the end of 50 cycles, an adhesion test was performed. Table 4 shows the results.

A1120 in Table 4 is N-β-aminoethyl-γ-aminopropyltrimethoxysilane. Further, the adhesion was evaluated by a cellophane tape peeling method using a 1 mm goban.

[0067]

[Table 4]

[0068]

When the primer of the present invention is used, the disadvantage of using a conventional epoxy primer is A
When applied to a porous and fragile surface such as LC, the coating film tends to crack and is inferior in durability, and has insufficient adhesion to dense surfaces such as cement extruded plates. And the disadvantage that it cannot be used at low temperatures can be eliminated.

Claims (7)

[Claims] 1. A silyl group-containing vinyl having a main chain substantially consisting of a vinyl polymer chain and having at least one silicon-containing group bonded to a hydrolyzable group at a terminal and / or a side chain in one molecule. A primer for a porous inorganic substrate based on a composition comprising a base polymer and a curing catalyst which may be contained. 2. The silyl group-containing vinyl polymer having at least a glass transition point (Tg) of 10 ° C. or less and a glass transition point (Tg) of 3 or less.
The primer according to claim 1, comprising a silyl group-containing vinyl copolymer at 0 ° C or higher. 3. The primer according to claim 1, which comprises at least one amine having at least one silicon-containing group in the molecule bonded to a hydrolyzable group. 4. The primer according to claim 3, comprising an alkyl alcohol having 1 to 4 carbon atoms. 5. The primer according to claim 1, wherein the primer contains a pigment. 6. The primer according to claim 2, wherein the inorganic substrate is ALC. 7. The primer according to claim 3, wherein the inorganic substrate is a cement extrusion plate.