JPWO2020121672A1 - Primer composition - Google Patents

Abstract

Even when applied to a porous building material, the primer composition does not easily penetrate into the porous building material, and it is possible to exhibit high film-forming properties, and the film strength after application is strong. Provided is a primer composition capable of satisfactorily adhering a material and having excellent jointability when used for a pre-cast sealing material. The primer composition contains a methyl methacrylate-based polymer in which the proportion of methyl methacrylate contained in the resin (A) is 80% by weight or more and a weight average molecular weight of 60,000 or more, and the resin (B). It contains an alkoxysilyl group-containing methyl methacrylate-based polymer in which the proportion of methyl methacrylate contained is less than 80% by weight.

Description

The present invention relates to primer compositions.

Conventionally, in a residential building, a primer is applied to the adhered surface of the sealing material before it is applied to the adhered surface of the outer wall material. By applying the primer to the adherend surface of the outer wall material or the like, the adhesiveness between the adherend and the sealing material can be improved, and the adherend surface having a weak surface strength can be strengthened. In recent years, due to the demand for longer life of houses and maintenance-free, exterior wall materials and sealing materials with high durability performance have been developed, and in line with this, high durability performance has been improved for primers for building sealing materials. It is required.

In addition, ceramic-based or wood-based siding boards are often used as exterior wall materials for wooden houses, but since these siding boards are porous, they are easily affected by moisture and the primer easily penetrates. .. Therefore, good adhesive durability, particularly adhesive durability under wet conditions, has not always been obtained due to reasons such as a decrease in the film-forming property of the primer on the surface to which the outer wall material is adhered.

Therefore, (A) a primer composition containing a saturated hydrocarbon-based polymer having a hydroxyl group or a hydrolyzable group bonded to a silicon atom and having at least one silicon-containing group that can be crosslinked by forming a siloxane bond. Is known (see, for example, Patent Document 1). In the primer composition according to Patent Document 1, long-term adhesiveness can be improved. Further, (A) a hydroxyl group or alkoxy group-containing organopolysiloxane resin bonded to a silicon atom, (B) an amino group-containing silane compound, (C) an alkoxysilyl group-containing isobutylene-based polymer, and (D) a tin (IV) compound as a catalyst. , And (E) a primer composition composed of an organic solvent is known (see, for example, Patent Document 2). In the primer composition according to Patent Document 2, it has been proposed that it can be used for a porous surface.

On the other hand, after the sealing material is applied to the construction part such as the adherend surface, it may be necessary to repair the construction part due to deterioration of the sealing material or the like. In this case, when a new sealing material (post-casting sealing material) is applied after removing the existing sealing material, that is, the pre-casting sealing material, the pre-casting sealing material may not be completely removed. In this case, the post-casting sealing material must be succeeded to the pre-casting sealing material. In the jointing of the sealing material, the pre-cast sealing material and the post-cast sealing material are required to have good adhesiveness, but the adhesiveness often does not reach the desired target, and generally, the jointing is performed. Primers are also used in.

However, even if a primer is used in the jointing of the sealing materials, there may be a problem that the jointability between these sealing materials is inferior or that the sealing materials cannot be joined.

Therefore, a) a polyisocyanate having an isocyanurate ring, b) an epoxysilane compound, c) an aminosilane compound having a structure represented by a predetermined formula, an aminosilane compound having a structure represented by a predetermined formula, and a predetermined An epoxy containing at least one silane compound selected from the group consisting of ketimine silane compounds having a structure represented by a formula, d) a film-forming resin, and b) an epoxy silane compound being represented by a predetermined formula. Substitution of a modified silicone-based sealant which is a condensate of at least one kind of silane or a condensate of at least one kind of epoxysilane represented by a predetermined formula and at least one kind of alkoxysilane represented by a predetermined formula. A primer composition for use is known (see, for example, Patent Document 3).

Further, the primer composition is not a mere auxiliary material of the sealing material, for example, reduction of leaching of water, alkali, etc. from the inside of the porous substance to the sealing material adhesive surface, a plasticizer from the adherend or the sealing material, etc. There is also a demand for a role of reducing the migration of (see, for example, Non-Patent Document 1).

Japanese Unexamined Patent Publication No. 11-343429 Japanese Unexamined Patent Publication No. 2000-86990 Japanese Patent No. 4802448

Architectural Sealant Handbook, Japan Sealant Manufacturers Association, 2017, 19

However, although the primer composition described in Patent Document 1 can improve the adhesiveness to glass and metal, it cannot exert a sufficient effect on porous building materials. Further, although the primer composition described in Patent Document 2 is said to be applicable to a porous surface, it does not exhibit sufficient adhesive durability in practical use. That is, due to recent technological innovations, optimization of materials, simplification of the manufacturing process, and / or shortening of the manufacturing process, the characteristics required for the primer have been improved, and the conventional primer (primer composition) has been used. Does not have a primer composition that satisfies high levels of adhesiveness (for example, initial adhesiveness, water resistance, and heat resistance) to various adherends such as ceramic siding boards and aluminum coated plates. Further improvement is required.

Further, the primer composition for splicing described in Patent Document 3 merely exerts splicing property by aminosilane, and has high splicing property (normal adhesiveness, water resistance) and the like to a pre-cast sealing material. Since the standard is not satisfied, further improvement of these properties of the primer composition for splicing is required. Further, the primer composition has a property of reducing the leaching of water, alkali, etc. from the inside of the porous substance to the adhesive surface of the sealing material and the transfer of the plasticizer, etc. from the adherend and the sealing material (hereinafter referred to as the present specification). This property is also referred to as "barrier property").

Therefore, an object of the present invention is that the primer composition does not easily penetrate into the porous building material even when applied to the porous building material, can exhibit high film-forming property, and has strong film strength after application. An object of the present invention is to provide a primer composition capable of satisfactorily adhering a sealing material to a porous building material. Further, it is an object of the present invention to provide a primer composition having excellent splicability when used for a pre-cast sealing material.

In order to achieve the above object, the present invention comprises (A) a methyl methacrylate-based polymer in which the proportion of methyl methacrylate contained in the resin is 80% by weight or more and the weight average molecular weight is 60,000 or more. (B) A primer composition containing an alkoxysilyl group-containing methyl methacrylate-based polymer in which the proportion of methyl methacrylate contained in the resin is less than 80% by weight is provided.

In addition, the primer composition may further contain (C) an amino group-containing silane.

Further, the primer composition may further contain (D) epoxy resin.

Further, the primer composition may also contain (E) a silane-based cross-linking agent.

According to the primer composition of the present invention, even when applied to a porous building material, the primer composition does not easily penetrate into the porous building material, high film-forming property can be exhibited, and the film strength after application is strong. Therefore, it is possible to provide a primer composition which can adhere the sealing material satisfactorily to the porous building material and also has excellent jointability when used for the pre-cast sealing material.

<Definition and meaning of numerical values and terms>
The definitions and meanings of the terms used in this specification are as follows.

(Definition of room temperature)
The “room temperature (normal temperature)” in the present specification is a temperature of 23 ° C.

(Meaning of term: solid at room temperature (state))
As used herein, the term "solid at room temperature (state)" refers to a substance in which the substance of interest (eg, a given composition) is crystalline, partially crystalline, and / or glassy amorphous. It means that the material has a softening point (measured by the ring and sphere method) higher than 23 ° C., or a melting point. Here, the melting point is, for example, the maximum value of the curve measured during the heating operation by dynamic differential calorimetry (differential scanning calorimetry [DSC]), and the target material changes from the solid state to the liquid state. The temperature.

(Weight average molecular weight)
In the present specification, the weight average molecular weight can be measured by using, for example, HLC-8220 (manufactured by Tosoh Corporation) and using polystyrene as a standard substance under the following conditions.

Columns used: TSKgel SuperMultipore HZ-M x 2, TSKguardvolume SuperMP (HZ) -M x 1, TSKgel SuperMultipore HM-L x 1 Solvent: THF
Flow velocity: 1.0 ml / min
Measurement temperature: 40 ° C

(Glass-transition temperature)
The glass transition temperature (hereinafter, may be referred to as “Tg”) can be easily estimated from the type and amount of the monomer component by using the following Fox formula.

1 / Tg = W ₁ / Tg ₁ + W ₂ / Tg ₂ + ... + W _n / Tg _n (Fox formula)

In the Fox equation, Tg is, for example, the glass transition temperature (K) of the acrylic resin, W ₁ , W ₂ , ..., W _n is the weight fraction of each monomer, and Tg ₁ , Tg. _2, · · ·, Tg _n is the glass transition temperature of the homopolymer of each monomer. As the glass transition temperature of the homopolymer used in the Fox formula, the values described in the literature can be used. For example, the acrylic ester catalog of Mitsubishi Rayon Co., Ltd. (1997 edition) and Kyozo Kitaoka, " New Polymer Bunko 7 Introduction to Synthetic Resins for Paints ”, Polymer Publishing Association, p168-p169, etc.

<Overview of primer composition>
From the viewpoint of improving each property required for the primer composition, the present inventor has made various studies. For example, it is known that the use of aminosilane has excellent compatibility with a modified silicone-based sealing material and improves the jointability with the sealing material, but in the prior art, an acrylic component is used as a film-forming resin. (For example, Japanese Patent No. 4802448), there has been no prior art in which the improvement of adhesiveness by an acrylic component has been recognized. The present inventor has found the adhesiveness-imparting property of the acrylic component in the primer composition, and investigated a configuration that maximizes the properties thereof. As a result, by using a predetermined acrylic polymer and a silyl group-containing polymer, it is difficult for the polymer to penetrate into the porous building material, exhibit high film-forming property, and the film strength after coating is strong and porous. It has been found that a primer composition capable of satisfactorily adhering a sealing material to a building material and having excellent jointability can be obtained.

That is, the primer composition according to the present invention comprises (A) a methyl methacrylate-based polymer (hereinafter, referred to as a component (A)) and (B) an alkoxysilyl group-containing methyl methacrylate-based polymer (hereinafter, a component). It is a composition containing (referred to as (B)). Further, the primer composition according to the present invention includes (C) amino group-containing silane (hereinafter referred to as component (C)), (D) epoxy resin (hereinafter referred to as component (D)), and (E). A silane-based cross-linking agent (hereinafter referred to as component (E)) and / or other additives may be contained.

<Details of primer composition>
The primer composition according to the present invention contains (A) a methyl methacrylate-based polymer having a predetermined weight average molecular weight and (B) an alkoxysilyl group-containing methyl methacrylate-based polymer having a predetermined weight average molecular weight. It is composed. Further, the primer composition according to the present invention is prepared by adding the component (C), the component (D), the component (E), and / or other additives to the component (A) and the component (B). You can also. The primer composition according to the present invention has a property of being moisture-cured at room temperature.

<(A) Methyl methacrylate polymer>
As the methyl methacrylate-based polymer (A) according to the present invention, the proportion of methyl methacrylate contained in the resin solid at room temperature is 80% by weight or more, and the weight average molecular weight is Mw (GPC [gel permeation chromatography] method). A resin having an apparent weight average molecular weight in terms of polymethylmethacrylate) of 60,000 or more is preferable.

By setting the proportion of methyl methacrylate contained in the resin to 80% by weight or more and the weight average molecular weight to 60,000 or more, even when the primer composition according to the present invention is applied to a porous building material, it is porous. It becomes difficult for the primer composition to penetrate into the building material. As a result, the primer composition according to the present invention can exhibit high film-forming property, the film strength after coating becomes strong, and excellent adhesiveness is exhibited.

The resin includes a copolymer of methyl methacrylate, methyl methacrylate and methyl acrylate, ethyl acrylate, butyl acrylate, acrylonitrile, acrylic acid, methacrylic acid, 2-hydroxyacrylate, maleic anhydride, styrene, α-methylstyrene, etc. Copolymers with any one or more of the copolymerizable monomers of the above are included.

As the copolymerizable monomer, alkyl acrylate having an alkyl group having 1 to 4 carbon atoms such as methyl acrylicate, ethyl acrylate, and n-butyl acrylate, and (meth) acrylic acid are preferable, and methyl acrylate, ethyl acrylate, and the like. (Meta) acrylic acid is more preferable, and methyl acrylate and (meth) acrylic acid are further preferable. By copolymerizing methyl methacrylate with these monomers, the solubility of the component (A) in the solvent is increased, and the viscosity of the primer composition according to the present invention becomes an appropriate viscosity (thickening), so that the porous building material It becomes difficult to penetrate into. Therefore, the primer composition according to the present invention can exhibit high film-forming properties, strengthen the film strength after coating, and exhibit excellent adhesiveness.

As a commercially available product of the component (A), for example, Delpouda (registered trademark) 80N (manufactured by Asahi Kasei Kogyo Co., Ltd., polymethylmethacrylate, methylmethacrylate / methylacrylate = 97.5 / 2.5), which is a copolymer with methyl acrylate. Weight ratio, weight average molecular weight 100,000, reduction viscosity 0.54 deciliter / g, glass transition temperature 105 ° C), and Dianal (registered trademark) BR-84 (Mitsubishi Rayon), which is a copolymer with (meth) acrylic acid. Examples thereof include polymethyl methacrylate, a weight average molecular weight of 100,000, a glass transition temperature of 105 ° C., and an acid value of 6.5 mgKOH / g).

The weight average molecular weight Mw of the component (A) is preferably 60,000 or more, more preferably 70,000 or more, further preferably 80,000 or more, and particularly preferably 90,000 or more. The weight average molecular weight Mw of the component (A) according to the present invention is usually preferably 200,000 or less, more preferably 180,000 or less, further preferably 160,000 or less, and particularly preferably 140,000 or less. .. When the weight average molecular weight Mw of the component (A) is 60,000 or more, the barrier property, the adhesive durability, and the adhesiveness to the porous surface of the primer composition are increased, and the weight average molecular weight Mw is 200,000 or less. When this is the case, good adhesive durability, workability, and adhesiveness to the porous surface of the primer composition can be obtained.

The proportion of methyl methacrylate contained in the component (A) is preferably 80% by weight or more, more preferably 90% by weight or more, still more preferably 95% by weight or more. The glass transition temperature of the component (A) is preferably 80 ° C. or higher, more preferably 90 ° C. or higher, further preferably 95 ° C. or higher, preferably 140 ° C. or lower, more preferably 120 ° C. or lower, further preferably 110 ° C. or lower. ..

The amount of the component (A) added to the primer composition is preferably 1% or more, more preferably 2% or more, further preferably 3% or more, preferably 20% or less, more preferably 15% or less, and 10% or less. More preferred. If the amount added to the primer composition exceeds 20%, the viscosity during the coating operation may increase and the workability may decrease. If the amount is less than 1%, the primer composition becomes porous when applied to the porous building material. It may penetrate into building materials and may not be able to exhibit high film-forming properties. In addition, this addition amount shows the ratio when the mass of the whole primer composition is 100%.

<(B) Alkoxysilyl group-containing methyl methacrylate polymer>
(B) The alkoxysilyl group-containing methyl methacrylate-based polymer is a (meth) acrylic ester polymer having an alkoxysilyl group and using methyl methacrylate, which is solid at room temperature, as an essential monomer.

As the (B) alkoxysilyl group-containing methyl methacrylate-based polymer according to the present invention, the proportion of methyl methacrylate contained in the resin is less than 80% by weight, and the weight average molecular weight is Mw (GPC [gel permeation chromatography] method). A resin having a polystyrene-equivalent apparent weight average molecular weight) of less than 60,000 is preferable.

Due to the component (B), the primer composition exhibits excellent adhesiveness to the cured product (pre-cast sealing material) of the sealing material, and realizes good jointability. Further, when the component (B) and the component (C) described later are used in combination, better adhesiveness and good jointability of the sealing material to the cured product (pre-cast sealing material) are exhibited. Further, the alkoxysilyl group of the component (B) and the alkoxysilyl group of the component (C) described later are cured to exhibit excellent adhesiveness to a base material (siding board or the like). Further, by cross-linking the silyl group of the component (B) and the silyl group of the component (C), the hot water adhesion resistance to the substrate can be improved.

(Alkoxysilyl group)
The alkoxysilyl group of the component (B) has an alkoxy group bonded to a silicon atom and can be crosslinked by a silanol condensation reaction. Examples of the alkoxysilyl group include a group represented by the following general formula (1).

In the general formula (1), R ¹ is an alkyl group having 1 to 20 carbon atoms, a substituted alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and carbon. an aralkyl group having 7 to 20, when the R ¹ there are two or more, they may be the same or may be different. X represents an alkoxysilyl group, and when two or more Xs are present, they may be the same or different. a indicates 0, 1, 2, or 3. It is preferable that a is 2 or 3 in the alkoxysilyl group of the general formula (1). When a is 3, the curing rate is higher than when a is 2.

Specific examples of R ¹ include an alkyl group such as a methyl group and an ethyl group, a substituted alkyl group such as a methoxymethyl group, and a cycloalkyl group such as a cyclohexyl group. Of these, a methyl group is preferable, and a substituted alkyl group in which α carbon is substituted with a polar group is preferable from the viewpoint of increasing the curing rate.

The alkoxysilyl group represented by X is not particularly limited, and any conventionally known alkoxysilyl group may be used. Among the alkoxy groups, the group having a small number of carbon atoms has a higher reactivity, and the reactivity decreases as the number of carbon atoms increases in the order of methoxy group> ethoxy group> propoxy group. Although it can be selected according to the purpose and application, a methoxy group or an ethoxy group is usually used. In the case of the alkoxysilyl group represented by the general formula (1), a is preferably 2 or more in consideration of curability.

Specifically, examples of the alkoxysilyl group include a trialkoxysilyl group such as a trimethoxysilyl group and a triethoxysilyl group (-Si (OR ² ) ₃ ); a di-dimethoxysilyl group such as a methyldimethoxysilyl group and a methyldiethoxysilyl group. Alkoxysilyl groups (-SiR ¹ (OR ² ) ₂ ) can be mentioned. Here, R ¹ is the same as described above, and R ² is an alkyl group such as a methyl group or an ethyl group. As the alkoxysilyl group, a trimethoxysilyl group and a triethoxysilyl group are preferable, and a trimethoxysilyl group is more preferable, from the viewpoint of high reactivity. A methyldimethoxysilyl group and a methyldiethoxysilyl group are preferable from the viewpoint of obtaining a cured product having flexibility.

Further, the alkoxysilyl group may be used alone or in combination of two or more. The alkoxysilyl group may be present in either the main chain or the side chain.

The number (average value) of the alkoxysilyl groups of the component (B) is preferably 0.3 or more, more preferably 0.5 or more, further preferably 1 or more, and preferably 5 or less per molecule of the polymer. 3, 3 or less is more preferable, and 2.5 or less is further preferable. If the number of alkoxysilyl groups contained in the molecule is less than 0.3, the curability becomes insufficient, and if it is too large, the network structure becomes too dense, so that good mechanical properties are not exhibited.

(Method of introducing alkoxysilyl group)
In the preparation of the component (B), various known methods can be used for the introduction of the alkoxysilyl group into the (meth) acrylic acid ester polymer. For example, the following method can be mentioned as an example of the method for introducing an alkoxysilyl group.

(1) Copolymerize an unsaturated compound having an alkoxysilyl group.
(2) Polymerization is carried out using an initiator or chain transfer agent having an alkoxysilyl group.
(3) A (meth) acrylic acid ester polymer having a functional group such as a hydroxyl group is reacted with another functional group such as epoxysilane that can react with the functional group and a compound having an alkoxysilyl group.

Among these methods for introducing an alkoxysilyl group, (1) a method of copolymerizing an unsaturated compound having an alkoxysilyl group is preferable from the viewpoint that an alkoxysilyl group can be easily introduced. Further, a method in which the method (1) and the method (2) are used in combination is also preferable. For example, methyl methacrylate, 2-ethylhexyl methacrylate, 3-methacryloxypropyltrimethoxysilane, titanosendichloride as a metal catalyst, 3-mercaptopropyltrimethoxysilane (acting as an initiator by the action of titanosendichloride, and also as a chain transfer agent. It works.) And a benzoquinone solution as a polymerization initiator, and by using a synthesis method according to Synthesis Example 4 of WO2015-088021, an alkoxysilyl group-containing methyl methacrylate-based polymer containing a trimethoxysilyl group. A (meth) acrylic polymer can be obtained.

(Unsaturated compound having an alkoxysilyl group)
As the unsaturated compound having an alkoxysilyl group used for copolymerization, a (meth) acrylic acid alkyl ester having an alkoxysilyl group or vinylsilane is preferable. Examples of the compound include 3- (meth) acrylic such as 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, and 3- (meth) acryloxypropyltriethoxysilane. Examples thereof include vinyl alkoxysilanes such as loxypropylalkoxysilane and vinyltriethoxysilane. Among these, a (meth) acrylic acid alkyl ester having a substituted alkyl group having an alkoxysilyl group having 10 or less carbon atoms, preferably 3 or less carbon atoms is preferable.

(Other monomers other than the monomer having an alkoxysilyl group used in the component (B))
As the other monomer other than the monomer having an alkoxysilyl group used in the component (B) according to the present invention, a repeating unit represented by the general formula (2) containing methyl methacrylate as an essential monomer component is used. Examples thereof include a methyl methacrylate-based random copolymer having.

-CH ₂ C (R ³ ) (COOR ⁴ )-(2)

In the general formula (2), R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents a hydrocarbon group which may have a substituent. The (meth) acrylic acid ester means an acrylic acid ester and / or a methacrylic acid alkyl ester.

As the monomer having an alkoxysilyl group and other monomers other than methyl methacrylate used for synthesizing the polymer of the component (B) according to the present invention, a (meth) acrylic acid alkyl ester is preferable, and an alkyl group of an alkyl group is preferable. A (meth) acrylic acid alkyl ester having 1 to 30 carbon atoms is more preferable, and a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 30 carbon atoms and having no substituent is particularly preferable.

Examples of the (meth) acrylic acid alkyl ester compound include known compounds. For example, methyl acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate and the like can be mentioned. ..

Further, from the viewpoint of exhibiting excellent adhesion to the cured sealant (pre-cast sealant) and achieving good jointability, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, A (meth) acrylic acid alkyl ester having an ester group having 8 or more carbon atoms such as stearyl (meth) acrylic acid is preferable. From the viewpoint of imparting flexibility to the component (B), n-butyl acrylate (Tg; -55 ° C.), 2-ethylhexyl acrylate (Tg; -70 ° C.), lauryl acrylate (Tg; -3 ° C.) It is preferable to use a (meth) acrylic acid alkyl ester having a glass transition temperature (Tg) of 0 ° C. or lower. The glass transition temperature in this paragraph indicates the glass transition temperature of the homopolymer.

The hydrocarbon group such as the alkyl group of the (meth) acrylic acid ester may have a substituent such as a hydroxyl group, an alkoxy group, a halogen atom or an epoxy group. Examples of such compounds include (meth) acrylic acid ester having a hydroxyl group such as hydroxyethyl (meth) acrylate, (meth) acrylic acid ester having an alkoxy group such as methoxyethyl (meth) acrylate, and glycidyl (meth). Examples thereof include (meth) acrylic acid ester having an epoxy group such as acrylate, and (meth) acrylic acid ester having an amino group such as diethylaminoethyl (meth) acrylate. An unsaturated compound (macromonomer or macromer) having a polymer chain such as an acrylic acid ester having a polystyrene chain can also be used.

Further, the alkoxysilyl group-containing methyl methacrylate-based polymer of the component (B) contains a repeating unit derived from a compound having copolymerizability with the repeating unit derived from the (meth) acrylic acid ester compound. But it may be. Examples of compounds having copolymerizability with (meth) acrylic acid ester compounds include acrylic acids such as (meth) acrylic acid; amide compounds such as (meth) acrylamide, vinyl ether compounds such as alkyl vinyl ethers; other acrylonitrile, styrene, etc. Examples thereof include α-methylstyrene, vinyl chloride and vinyl acetate.

(Polymer usage ratio)
The amount of methyl methacrylate in the polymer of the component (B) is less than 80% by mass, preferably 20% by mass or more, more preferably 30% by mass or more, still more preferably 40% by mass or more. Further, the ratio of the compound having copolymerizability with the (meth) acrylic acid ester compound is preferably 20% by mass or less, more preferably 10% by mass or less, and 5% by mass or less in the polymer of the component (B). More preferred. However, when a macromonomer is used, the amount of the macromonomer is preferably 10% by mass or less, more preferably 5% by mass or less, and 3% by mass or less in the polymer of the component (B). Is particularly preferable.

(Glass-transition temperature)
The component (B) has a glass transition temperature (Tg) of 0 ° C. or higher and 120 ° C. or lower. The glass transition temperature is preferably 0 ° C. or higher, more preferably 20 ° C. or higher, and even more preferably 40 ° C. or higher. Further, it is preferably 120 ° C. or lower, more preferably 100 ° C. or lower, and even more preferably 80 ° C. or lower. If the glass transition temperature is less than 0 ° C., the adhesive strength immediately after adhesion tends to be inferior. Further, when the glass transition temperature exceeds 120 ° C., the viscosity becomes high, and it tends to be difficult to apply the primer to the adherend. The glass transition temperature can be easily estimated using the Fox equation described above.

The molecular weight of the component (B) is a weight average molecular weight (polystyrene-equivalent molecular weight measured by the GPC method), preferably 1,000 or more, more preferably 2,000 or more, further preferably 3,000 or more, and 20,000 or less. Is preferable, 10,000 or less is more preferable, and 6,000 or less is further preferable. If the weight average molecular weight is less than 1,000, the initial adhesive force after coating is low, and if it exceeds 20,000, the viscosity during coating work becomes too high and workability deteriorates. Further, the polymer of the component (B) is preferably a solid at room temperature or has a ring-ball method softening point of 80 ° C. or higher.

The amount of the component (B) added to the primer composition is preferably 5% or more, more preferably 10% or more, further preferably 20% or more, preferably 60% or less, more preferably 50% or less, and 40% or less. More preferred. If the addition amount exceeds 60%, the viscosity at the time of coating work becomes too high, the workability deteriorates, and if it is less than 5%, good jointability cannot be realized. In addition, this addition amount shows the ratio when the mass of the whole primer composition is 100%.

(Polymerization method of component (B))
As the polymerization method of the component (B), a radical polymerization method can be used. For example, a usual solution polymerization method or bulk polymerization method using a thermal polymerization initiator such as benzoyl peroxide or azobisisobutyronitrile can be used. Further, a method of irradiating light or radiation with a photopolymerization initiator to polymerize can also be used. In radical copolymerization, a chain transfer agent such as lauryl mercaptan or 3-mercaptopropyltrimethoxysilane may be used to adjust the molecular weight. Further, a radical polymerization method using a thermal polymerization initiator can be used, and a polymer of the component (B) according to the present invention can be easily obtained by such a method. In addition, other polymerization methods such as the living radical polymerization method described in JP-A-2000-086998 may be used.

<(C) Amino group-containing silane>
From the viewpoint of not only improving the adhesiveness to the base material (adhesive member), but also improving the adhesiveness to the cured sealant (pre-cast sealing material) when used in combination with the component (B), resulting in excellent transferability. Therefore, it is preferable that the primer composition according to the present invention further contains (C) an amino group-containing silane. Examples of the amino group of the (C) amino group-containing silane include a monovalent functional group obtained by removing hydrogen from a primary amine or a secondary amine, and a ketimine group. Specifically, examples of the (C) amino group-containing silane according to the present invention include aminosilanes and ketimine-based silanes. The ketimine-based silane is a silane compound that produces a predetermined amine by reacting with water, and in the present invention, the ketimine-based silane is also included in the component (C).

Examples of aminosilanes include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (β-aminoethyl) -3-aminopropyltrimethoxysilane, and N- (β-aminoethyl) -3-. Mono-silylaminosilanes such as aminopropyltriethoxysilane, N- (β-aminoethyl) -3-aminopropylmethyldiethoxysilane, bis- (trimethoxysilylpropyl) amines, bis- (triethoxysilylpropyl) amines, Examples thereof include bis- (triethoxysilylpropyl) ethylenediamine, N- [2- (vinylbenzylamino) ethyl] -3-aminopropyltrimethoxysilane, and bis-silylaminosilane such as aminoethyl-aminopropyltrimethoxysilane.

Further, as the aminosilane, the above-mentioned reaction product of aminosilane and epoxysilane, the reaction product of aminosilane and silane having a (meth) acryloyloxy group, aminosilane and epoxy resin (bisphenol A diglycidyl ether, phenylglycidyl ether, etc.) Aminosilane reactants such as the reactants of aminosilane and polyacrylate; a condensate of the above silanes partially condensed (preferably a mixture of the above aminosilane, aminosilane reactants, and reactants). Aminosilane condensate); derivatives obtained by modifying these are also mentioned.

Examples of the ketimine-based silane include N- (1,3-dimethylbutylidene) -3- (trimethoxysilyl) -1-propaneamine and N- (1,3-dimethylbutylidene) -3- (triethoxy). Cyril) -1-propaneamine, N- (1,3-dimethylbutylidene) -3- (methyldimethoxysilyl) -1-propaneamine, N- (1,3-dimethylbutylidene) -3- (methyldi) Ethoxysilyl) -1-propaneamine and the like can be mentioned.

The blending amount of the component (C) is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, and 1 part by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B). The above is more preferable, 20 parts by mass or less is preferable, 10 parts by mass or less is more preferable, and 5 parts by mass or less is further preferable. The blending amount of the component (B) indicates the blending amount of the solid content obtained by removing the solvent component from the component (B).

<(D) Epoxy resin>
The primer composition according to the present invention can further contain (D) an epoxy resin. The (D) epoxy resin reacts with the (C) amino group-containing silane to strengthen the network structure obtained after the primer composition is cured, and has adhesiveness, water resistance, and adhesion durability under high temperature and high humidity conditions. Improve sex. In addition, the strong mesh structure enhances the barrier performance and prevents discoloration and deterioration of the sealant bonding portion of the adherend and the peripheral portion. In particular, the (D) epoxy resin reacts with a compound having a reactive active group to suppress migration of the active compound, thereby preventing discoloration, deterioration, etc. due to a compound having a reactive active group with respect to an epoxy group such as an amine compound. It exerts an excellent effect on.

As the epoxy resin (D), various epoxy resins can be used. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol S type epoxy resin and epoxy resin hydrogenated with these, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, alicyclic epoxy Resins, aliphatic epoxy resins, novolac type epoxy resins, urethane-modified epoxy resins with urethane bonds, fluorinated epoxy resins, rubber-modified epoxy resins (eg, polybutadiene, styrene-butadiene rubber (SBR), nitrile rubber (NBR), and CTBN. (Epoxy resin modified with any of the above rubbers, etc.), flame-retardant epoxy resin such as glycidyl ether of tetrabromobisphenol A, and the like. These epoxy resins can be used alone or in combination of two or more.

Among these epoxy resins, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy from the viewpoint of balance of workability, curability, adhesive strength, versatility of adherend, water resistance, durability, etc. Resins, bisphenol S-type epoxy resins and bisphenol A-type epoxy resins hydrogenated with them are preferable, bisphenol A-type epoxy resins and bisphenol F-type epoxy resins are more preferable, and bisphenol A-type epoxy resins are most preferable.

The molecular weight of the component (D) is not particularly limited, but the weight average molecular weight is preferably 300 or more, more preferably 350 or more, preferably 1,000 or less, and preferably 600 or less. More preferred. Further, from the viewpoint of ease of handling, it is preferable to use the (D) epoxy resin which is liquid at room temperature.

Molar ratio (EP group / amino) of active hydrogen derived from the amino group of the epoxy group of the component (D) and the amino group (primary amine or secondary amine and ketimine group) (the ketimine group is the active hydrogen after hydrolysis). The active hydrogen derived from the group) is preferably 0.4 or more, more preferably 0.6 or more, further preferably 0.8 or more, preferably 3.0 or less, more preferably 2.0 or less, and 1.0 or less. Is more preferable.

The blending amount of the component (D) is preferably 0.1 part by mass or more, more preferably 0.3 part by mass or more, and 0.5 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B). More than parts by mass is more preferable, 40 parts by mass or less is preferable, 30 parts by mass or less is more preferable, and 20 parts by mass or less is further preferable. The blending amount of the component (B) indicates the blending amount of the solid content obtained by removing the solvent component from the component (B).

<(E) Silane-based cross-linking agent>
The primer composition according to the present invention can further contain (E) a silane-based cross-linking agent. Examples of the (E) silane-based cross-linking agent include silane compounds having two or more alkoxysilyl groups excluding the component (C). The silane-based cross-linking agent has the effect of strengthening the network structure obtained after the primer composition is cured and improving the adhesiveness, water-resistant adhesiveness, and adhesive durability under high-temperature and high-humidity conditions. Further, the (E) silane-based cross-linking agent can also improve the barrier property of the primer composition by promoting cross-linking. Therefore, from the viewpoint of improving the crosslink density, the number of alkoxysilyl groups in the component (E) is preferably 2 or more, and more preferably 3 or more.

As the component (E), isocyanurate silane, carbacilatran, a silane reaction product, a silane condensate, or the like can be used.

Examples of the isocyanate silane include tris- (trimethoxysilylpropyl) isocyanate. Examples of carbacilatran include a reaction product of 1.0 mol of 3-aminopropyltrimethoxysilane and 2.0 mol of 3-glycidoxypropyltrimethoxysilane described in Japanese Patent No. 3831481.

As a silane reaction product and a silane condensate (however, in this paragraph, compounds containing a primary amino group and a secondary amino group are excluded), a reaction product of aminosilane and an epoxysilane, and a reaction of aminosilane and isocyanatesilane. A product, a reaction product of aminosilane and a silane having a (meth) acryloyloxy group, a reaction product of aminosilane and an epoxy resin (bisphenol A diglycidyl ether, phenylglycidyl ether, etc.), a reaction product of aminosilane and polyisocyanate, a reaction product of aminosilane and Aminosilane reaction product such as a reaction product with a polyacrylate; Aminosilane condensation product obtained by partially condensing the above silanes (preferably, the above aminosilane, isocyanate silane, aminosilane reaction product, and a mixture of the reactants are partially condensed. Body); Examples thereof include amino-modified silyl polymers and silylated amino polymers, which are derivatives obtained by modifying these.

When the component (E) is used, the blending amount of the (E) silane-based cross-linking agent is preferably 0.1 part by mass or more with respect to 100 parts by mass of the total amount of the component (A) and the component (B), and 1 mass by mass. More than parts is more preferable, 2 parts by mass or more is further preferable, 60 parts by mass or less is more preferable, 30 parts by mass or less is more preferable, and 15 parts by mass or less is further preferable. The blending amount of the component (B) indicates the blending amount of the solid content obtained by removing the solvent component from the component (B).

<Other additives>
The primer composition of the present invention may contain other additives, if necessary. Examples of such additives include solvents, condensation reaction accelerating catalysts, dehydrating agents, silane-based adhesion-imparting agents, polyisocyanate compounds, chlorinated polymers, polyurethane-based resins, pigments, dyes, anti-aging agents, and antistatic agents. , Flame retardants and the like.

(solvent)
Examples of the solvent include aliphatic compounds (n-hexane, heptane, etc.), aromatic compounds (toluene, xylene, etc.), alcohols (methanol, ethanol, isopropyl alcohol, butanol, etc.), ketones (acetone, methyl ethyl ketone, etc.), esters. Examples thereof include organic solvents such as (ethyl acetate, butyl acetate, etc.), ether (tetratetra, butyl cellosolve, etc.), and ligroin. As the solvent, one or more of these can be used, and an appropriate amount can be added to the primer composition according to the present invention.

Among these solvents, methyl ethyl ketone and ethyl acetate are preferable from the viewpoint of improving the adhesion speed and workability. The solvent is preferably used after being sufficiently dried or dehydrated.

The content of the solvent is preferably 40% or more and 90% or less, and preferably 50% or more and 80% or less, based on the total mass of the primer composition according to the present invention. When the content of the solvent is in this range, good coatability can be obtained. The content of the solvent in the primer composition according to the present invention can be appropriately changed according to the use, purpose and the like of the composition.

(Condensation reaction accelerator)
As a catalyst for accelerating the condensation reaction of the alkoxysilyl group, a widely known curing catalyst can be widely used, and for example, a silanol condensation catalyst is preferably used. Examples of the silanol condensation catalyst include a metal-based catalyst, a tin-based catalyst, an amine-based catalyst, and the like, and examples of the amine-based catalyst include organic metal compounds, amines (particularly, tertiary amines), and tertiary amines. And salts of carboxylic acid and the like.

Specifically, examples of the organic metal compound include divalent organic tin compounds such as tin octylate; dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, and a reaction product of dibutyltin oxide and a phthalate ester. Tetravalent organic tin compounds; chelate compounds of various metals such as dibutyltin bis (acetylacetonate), titanium tetrakis (acetylacetonate), aluminum tris (acetylacetonate), acetylacetone bismuth; titanic acid esters such as tetrapropyl titanate. Kind and the like.

Examples of amines include primary and secondary amines such as octylamine; polyamines; cyclic amines such as N-methylmorpholine and 1,8-diazabicyclo [5,4,0] -7-undecene (DBU). Amine compounds such as aminophenol compounds such as 2,4,6-tris (dimethylaminomethyl) phenol and carboxylates thereof; reaction products of excess polyamines and epoxy compounds and the like. In addition, these catalysts can be used alone or in combination of two or more.

Among these, tin-based catalysts and amine-based catalysts are preferable, and tin-based catalysts are particularly preferable, from the viewpoint of having a large amount of catalytic ability in a small amount. Either one or both of the tin catalyst and the amine catalyst may be used. As the tin-based catalyst, either one of divalent or tetravalent can be used alone, or both can be used in combination. As the amine-based catalyst, it is preferable to use tertiary amines.

When a condensation reaction accelerating catalyst is used, the blending amount of the condensation reaction accelerating catalyst is preferably 0.01 parts by mass or more, preferably 0.05 parts by mass, based on 100 parts by mass of the total amount of the components (A) and (B) components. More than parts are more preferable, 0.1 parts by mass or more is further preferable, 10 parts by mass or less is more preferable, 2 parts by mass or less is more preferable, and 1 part by mass or less is further preferable.

(Dehydrating agent)
Examples of the dehydrating agent include silane compounds such as vinyltrimethoxysilane, dimethoxydiphenylsilane, methyltrimethoxysilane, phenyltrimethoxysilane, tetraethoxysilane and tetramethoxysilane; and ester compounds such as methyl orthostate and ethyl orthostate. be able to. These dehydrating agents may be used alone or in combination of two or more. As the dehydrating agent, a silane compound is preferable, and dimethoxydiphenylsilane and phenyltrimethoxysilane are more preferable.

When a dehydrating agent is used, the blending amount of the dehydrating agent is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, based on 100 parts by mass of the total amount of the component (A) and the component (B). 1, 1 part by mass or more is further preferable, 20 parts by mass or less is preferable, 10 parts by mass or less is more preferable, and 5 parts by mass or less is further preferable.

(Silane adhesive)
The silane-based adhesion imparting agent can be added to the primer composition according to the present invention from the viewpoint of being excellent in the effect of improving the adhesiveness to the poorly adhesive coated surface. Examples of the silane-based adhesive imparting agent include epoxy silane, acrylic silane, mercapto silane, urea silane-based coupling agent, and isocyanate silane.

Examples of the epoxysilane include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 3-glycidoxypropylmethyldi. Examples thereof include ethoxysilane. Examples of the acrylic silane include 3-methacryloxypropyltrimethoxysilane. Examples of the mercaptosilane include 3-mercaptopropyltrimethoxysilane. Examples of the ureasilane-based coupling agent include 3-ureidopropyltrimethoxysilane and 3-ureidopropyltriethoxysilane. Examples of isocyanatesilane include 3-isocyanatepropyltriethoxysilane.

From the viewpoint of adhesiveness, epoxy silane, acrylic silane-based silane, urea silane-based coupling agent, and isocyanate silane are preferable, and epoxy silane is more preferable.

When a silane-based adhesive-imparting agent is used, the blending amount of the silane-based adhesive-imparting agent is preferably 0.1 part by mass or more, preferably 0.5 parts by mass or more, based on 100 parts by mass of the total amount of the component (A) and the component (B). More than parts by mass is more preferable, 1 part by mass or more is further preferable, 20 parts by mass or less is more preferable, 10 parts by mass or less is more preferable, and 5 parts by mass or less is further preferable.

(Polyisocyanate compound)
The primer composition according to the present invention may further contain a polyisocyanate compound. The polyisocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups in the molecule. The polyisocyanate compound can exhibit high film-forming properties, strengthen the film strength after coating, and exhibit excellent adhesiveness. Further, the isocyanate group is cured to exhibit excellent adhesiveness to a base material (siding board or the like), and the isocyanate group is crosslinked, so that the hot water adhesiveness to the base material and the heat resistant adhesiveness can be improved.

Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), and polymethylene polyphenyl isocyanate (polymeric MDI); hexamethylene diisocyanate (HDI). And other aliphatic polyisocyanates; alicyclic polyisocyanates such as isophorone diisocyanate (IPDI); adducts using addition reactants of these polyisocyanates, such as trimethylolpropane and glycol; these isocyanurate-modified polyisocyanates; Alohanate-modified polyisocyanate; Bullet-modified polyisocyanate and the like. Such polyisocyanate compounds may be used alone or in combination of two or more.

The polyisocyanate compound preferably has three or more isocyanate groups from the viewpoint of good film-forming property and better adhesiveness to a poorly adhesive coated surface. Examples of the polyisocyanate compound having three or more isocyanate groups include a polyisocyanate-adduct obtained by reacting the above polyisocyanate compound with a compound such as tris (phenylisocyanate) thiophosphate or trimethylolpropane (TMP). And adduct, biuret form, isocyanurate form and the like of the polyisocyanate compound are also mentioned. Hereinafter, such a polyisocyanate compound is referred to as an "isocyanate adduct". These can be used alone or in combination of two or more.

Examples of such an isocyanate adduct include an HDI-TMP adduct obtained by reacting HDI with TMP, an XDI-TMP adduct obtained by reacting XDI with TMP, and a TDI obtained by reacting TMP. TDI-TMP adduct, TMXDI-TMP adduct obtained by reacting TMXDI with TMP, HXDI-TMP adduct obtained by reacting HXDI with TMP, IPDI-TMP adduct obtained by reacting IPDI with TMP , HDI biuret, HDI isocyanurate, IPDI isocyanurate, TDI isocyanurate and the like. Among these, the TDI-TMP adduct and the isocyanurate modified product obtained by reacting TDI and TMP are preferable.

As the polyisocyanate compound having an isocyanurate ring, an isocyanurate-modified form of the diisocyanate compound obtained by trimerizing the diisocyanate compound is preferable. Examples of the diisocyanate compound include the aromatic polyisocyanates exemplified above. Of these, the polyisocyanate compound having an isocyanurate ring obtained by reacting a mixture of TDI and HDI has better initial adhesiveness and hot water adhesiveness to a poorly adhesive coated surface, and sufficient adhesiveness can be obtained. It is preferable from the viewpoint of being able to be used.

Commercially available products of the polyisocyanate compound include, for example, tris (phenylisocyanate) thiophosphate (dismodule RFE, manufactured by Bayer), and a polyisocyanate compound (dismodule) having an isocyanurate ring obtained by reacting a mixture of HDI and TDI. HL, manufactured by Bayer), polymethylene polyphenyl isocyanate (Sumijour 44V-10, manufactured by Sumika Bayer Urethane Co., Ltd.) and the like.

(Chlorinated polymer)
The chlorinated polymer can exhibit high film-forming properties, strengthen the film strength after coating, and exhibit excellent adhesiveness. The chlorinated polymer includes chlorinated isoprene-based synthetic rubber, chlorinated polyethylene, chlorinated polypropylene, chlorinated polyethylene / propylene copolymer, chlorinated polybutadiene, chlorinated polystyrene, chlorinated polybutadiene / styrene copolymer, and chloro. Examples thereof include sulphonized polyethylene, chlorosulphonized polyethylene and vinyl acetate copolymers.

(Polyurethane resin)
Polyurethane-based resins can exhibit high film-forming properties, strengthen the film strength after coating, and exhibit excellent adhesiveness. The polyurethane resin is a compound in which a monomer is copolymerized by a urethane bond in which an isocyanate group and an alcohol group are condensed. As the polyurethane-based resin, various polyurethane-based resins can be used as long as the effects of the present invention are exhibited. The polyurethane resin preferably has a number average molecular weight of 3,000 or more and 60,000 or less from the viewpoint of adhesiveness of the primer composition. The polyurethane resin may be used alone or in combination of two or more.

Polyurethane resins include polyurethane resin (Pandex (registered trademark) T-5205, number average molecular weight: 60,000, manufactured by DIC Corporation), polyurethane resin (Pandex (registered trademark) T-5201, number average molecular weight: 55). , 000, manufactured by DIC Corporation) and other commercially available products can be used.

(Pigment)
Examples of the pigment include one or both of an inorganic pigment and an organic pigment. For example, organic pigments such as titanium dioxide, zinc oxide, ultramarine, red iron oxide, lithopone, lead, cadmium, iron, cobalt, aluminum, hydrochloride, sulfate inorganic pigments, azo pigments, and copper phthalocyanine pigments can be used.

(dye)
As the dye, a conventionally known dye can be used. For example, black dye, yellow dye, red dye, blue dye, brown dye and the like can be mentioned.

(Anti-aging agent)
Examples of the antiaging agent include hindered phenol compounds, hindered amine compounds, benzotriazole compounds and the like.

(Antistatic agent)
Examples of the antistatic agent include hydrophilic compounds such as quaternary ammonium salts, polyglycols, and ethylene oxide derivatives.

(Flame retardants)
Examples of the flame retardant include chloroalkyl phosphate, dimethyl / methyl phosphonate, bromine / phosphorus compound, ammonium polyphosphate, neopentyl bromide-polyether, brominated polyether and the like.

<Preparation method of primer composition>
The method for preparing the primer composition according to the present invention is not particularly limited, and for example, it can be produced using a mixer capable of uniformly mixing liquids. For example, the materials (component (A), component (B), component (C), component (D), component (E), and / or other additives) constituting the primer composition are weighed in a predetermined amount and weighed. Each of these materials can be produced by mixing them using a stirrer with a single-screw or two-screw shaft or a tank having a pulsator or the like at the bottom. In particular, it is preferable to use a device provided with a jacket and capable of variably adjusting the material temperature.

<Method of applying primer composition>
The method for applying the primer composition according to the present invention to an adherend is not particularly limited, but as an example, the following application method is preferable. First, the primer composition according to the present invention is lifted with a brush, a brush, or the like to drain the liquid so that the liquid does not fall, and then uniformly applied to the adherend surface at a coating amount of ^{50 to 400 ml / m 2.} do. After 30 minutes to 8 hours have passed after application, the sealing material is applied. It is preferable to avoid construction in rainy weather and use in an environment where water droplets or the like remain on the adherend surface, and it is preferable to perform construction under conditions of 5 ° C. or higher and 35 ° C. or lower.

<Use>
The primer composition according to the present invention can be suitably used for applications such as primer compositions for construction, civil engineering, concrete, wood, metal, glass, plastic, etc., sealing materials, adhesives, and the like. .. In addition, the primer composition according to the present invention is excellent in jointability to a cured product of the sealing material, and therefore can be particularly preferably used for the sealing material.

Further, the primer composition according to the present invention can also be suitably used as a primer for a poorly adhesive coating member. Examples of the material of the poorly adhesive coating member to which the primer composition according to the present invention can be used include an acrylic electrodeposition coating member, a fluorine baking coating member, an anodizing coating member and the like. Further, the primer composition according to the present invention can be used for members other than the poorly adhesive coating member.

<Effect of embodiment>
The primer composition according to the present invention is composed of a component (A) and a component (B) containing an alkoxysilyl group, and the component (A) and / or the component (B) has a predetermined weight average molecular weight and /. Alternatively, since it has a predetermined ratio of methyl methacrylate, the primer composition is porous even when it is applied or brought into contact with a porous building material as an adherend (for example, the surface of a small edge such as a siding material). It has an effect that does not easily penetrate into building materials. Therefore, the primer composition according to the present invention can exhibit high film-forming property and can strengthen the film strength after coating. In addition, the primer composition according to the present invention can be easily applied with a brush or the like, and can exhibit high workability. Therefore, the primer composition according to the present invention can also be applied to an outer wall material such as a ceramic-based or wood-based siding board, particularly an outer wall material coated with a sealer, a paint, or the like.

Further, since the primer composition according to the present invention has a high barrier property, it is possible to suppress the transfer of the plasticizer or the like from the adherend or the sealing material, and to exhibit high adhesive durability for a long period of time. can. The primer composition according to the present invention can exhibit high adhesiveness even on a wet surface.

An embodiment will be described below in more detail. Needless to say, these examples are examples and should not be construed in a limited manner.

(Synthesis Example 1: Alkoxysilyl Group-Containing Methacrylate Resin)
As an alkoxysilyl group-containing methacrylic resin, a (meth) acrylic polymer having a trimethoxysilyl group was synthesized. Specifically, methyl methacrylate 70.00 g, 2-ethylhexyl methacrylate 30.00 g, 3-methacryloxypropyltrimethoxysilane 12.00 g, titanosendichloride 0.10 g as a metal catalyst, 3-mercaptopropyltrimethoxysilane 8.60 g. Using 20.00 g of a benzoquinone solution (95% THF solution) as a polymerization terminator, a (meth) acrylic polymer having a trimethoxysilyl group was obtained according to the method of Synthesis Example 4 of WO2015-088021.

The solid content of the obtained ethyl acetate solution of the reaction product was determined by heating at 105 ° C. and found to be 70.5%. The polystyrene-equivalent molecular weight of the obtained polymer measured by gel permission chromatography (GPC) was 4,000 in weight average molecular weight (Mw) and 2.4 in molecular weight distribution (Mw / Mn). .. Furthermore, ^{it was confirmed by 1} H-NMR measurement (measured in CDCl ₃ solvent using NMR400 manufactured by Shimadzu Corporation) that the number of trimethoxysilyl groups contained was 2 per molecule. The glass transition temperature was 61 ° C.

(Example, comparative example)
For each of Examples 1 to 12 and Comparative Examples 1 to 3, component (A), component (A'), component (B), component (C), component (D), component (E), and others. The additives were mixed at the blending ratios shown in Table 1 and stirred and mixed. As a result, the primer compositions according to Examples and Comparative Examples were obtained. Then, the following evaluations were carried out for each of the obtained primer compositions of Examples 1 to 12 and Comparative Examples 1 to 3. The results are shown in Table 1. In Table 1, the unit of the blending amount of each compounding substance is "g".

The details of the materials shown in Table 1 are as follows. The blending amount of the component (B) in Table 1 is the amount containing the solvent.
(Ingredient (A))
-Delpouda (registered trademark) 80NS: Asahi Kasei Kogyo Co., Ltd., polymethyl methacrylate, MMA / MA = 97.5 / 2.5 weight ratio, weight average molecular weight: 100,000, reduced viscosity: 0.54 deciliters / g, glass Transition temperature (Tg): 105 ° C
-Dianal BR84: manufactured by Mitsubishi Rayon, polymethylmethacrylate, weight average molecular weight: 100,000, glass transition temperature (Tg): 105 ° C., acid value: 6.5 mgKOH / g

(Ingredient (A'))
-Alfon (registered trademark) UH-2170: manufactured by Toa Synthetic Co., Ltd., styrene, acrylic, weight average molecular weight: 14,000, OH value: 88 mgKOH / g, glass transition temperature (Tg): 60 ° C / DSC

(Component (C))
KBM903: Shin-Etsu Chemical Co., Ltd., amine-based coupling agent, weight average molecular weight: 179, 3-aminopropyltrimethoxysilane ・ Dynasylan1124: Ebonic, weight average molecular weight: 343, amine-based coupling agent, bis (3-) Trimethoxysilylpropyl) amine / ketimine-based coupling agent: N- (1,3-dimethylbutylidene) -3- (trimethoxysilyl) -1-propaneamine, weight average molecular weight: 261

(Component (D))
-JER828: Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, liquid, weight average molecular weight: 370, d = 1.17, epoxy equivalent: 184 to 194
EP1001: Mitsubishi Chemical Corporation, epoxy resin, solid, weight average molecular weight: 900, d = 1.19, softening point: 97 ° C., epoxy equivalent: 450-500

(Component (E))
X-12-965: Shin-Etsu Chemical Co., Ltd., isocyanurate-based coupling agent, weight average molecular weight: 616, number of Si groups: 3, tris- (trimethoxysilylpropyl) isocyanurate

(Dehydrating agent)
-KBM202SS: Shin-Etsu Chemical Co., Ltd., phenyl-based coupling agent, diphenyldimethoxysilane-A-1630: Momentive Co., Ltd., coupling agent, trimethoxymethylsilane

(catalyst)
-U-360: Nitto Kasei Co., Ltd., mercapto-based catalyst, dibutyltin isooctylthioglycolate

(Evaluation method: Workability)
In the evaluation of workability, the brush coating property and film forming property of the primer composition were evaluated. Specifically, with regard to brush coatability, first, the primer composition according to Example 1 was applied to the edge surface of a siding material (Moen Siding M, manufactured by Nichiha Corporation) using a brush. Similarly, as a comparison target, a primer composition for comparison (MP3000, manufactured by Cemedine Co., Ltd.) was used, and the siding material (Moen Siding M, manufactured by Nichiha Corporation) was applied to the edge surface of the siding material using a brush.

Then, with respect to the brush coatability, the ease of coating the primer composition at the time of application was evaluated by comparing the primer composition according to Example 1 with the primer composition for comparison. The evaluation criteria are as follows.

"○": The ease of painting is equal to or higher than that of MP3000.
"X": Harder to apply than MP3000.

Regarding the film-forming property, the state of the film formed by the primer composition on the fore-edge surface was visually evaluated without all of the primer composition applied to the fore-edge surface penetrating into the fore-edge surface. The evaluation criteria are as follows.

"○": Uniform film formation is observed.
"X": Sparse (partially infiltrated, disappeared) film formation is observed.

Other examples and comparative examples were evaluated in the same manner. The evaluation results are shown in Table 1.

(Evaluation method: Joint adhesiveness)
The joint adhesiveness was evaluated as follows. First, a sample obtained by curing a modified silicone-based sealing material (“POS Seal LM” manufactured by Cemedyne) as an adherend for pre-casting in a 23 ° C. and 50% RH environment for 7 days was prepared. Next, the primer composition according to Example 1 was applied to the surface of the cured sealing material (adhesive body), left for 30 minutes in a 23 ° C. and 50% RH environment, and then modified for splicing on the surface. A silicone-based sealing material (“POS Seal LM Super Weatherproof” manufactured by Cemedyne) was cast into a bead shape to prepare a test piece. This test piece was cured in a 23 ° C. and 50% RH environment for 3 days, and then cured in a 50 ° C. and 40% RH environment for 4 days, and then a part of the adhesive interface (that is, an adherend and a modified silicone system). A part of the adhesive interface with the sealant) was cut with a knife, and this cut portion was peeled off by hand. Then, the fractured state was evaluated by visually observing the peeled state. The evaluation results are shown in the column of "Splicting Adhesiveness: POS Seal LM" in Table 1. The evaluation criteria are as follows.

"○": The pre-strike and / or post-strike sealant is coagulated and broken.
"X": The cured product of the primer composition is interfacially fractured from the pre-cast sealant.

In addition, except that a sample obtained by curing a modified silicone-based sealing material (“POS Seal LM Super Weatherproof” manufactured by Cemedyne) in a 23 ° C. and 50% RH environment for 7 days was prepared as an adherend for pre-casting, as described above. The joint adhesiveness was evaluated in the same manner. The evaluation results are shown in the column of "Split Adhesiveness: POS Seal LM Super Weatherproof" in Table 1. Furthermore, other examples and comparative examples were evaluated in the same manner. The evaluation results are shown in Table 1.

(Evaluation method: Barrier property)
The barrier property was evaluated as follows. A chlorinated polypropylene-based coating agent (20% ethyl acetate solution of Supercron 814HS (manufactured by Nippon Paper Industries, Ltd.)) is applied to the surface of the stainless steel plate and left for 24 hours in an environment of 23 ° C. to obtain chlorinated polypropylene. A stainless steel plate on which a coating layer was formed was obtained. The primer according to Example 1 was applied onto the coating layer of the obtained stainless steel plate (0.02 g / cm ² ), and dried in an environment of 23 ° C. for 1 hour.

A sealing material (POS seal LM super weather resistant) is placed in a bead shape on the dried primer and cured for 3 days in a 23 ° C. 50% RH environment and for 4 days in a 50 ° C. 40% RH environment. Was cured. After further heating and accelerating in an environment of 70 ° C. for 3 days, the sealing material was cut off with a cutter along the adhesive interface, and the coating layer portion touched by the sealing material was observed to confirm the color change. The evaluation criteria are as follows.

"◎": No change "○": Almost no change "△": Slight change is seen "×": Change (discoloration) is seen

Other examples and comparative examples were evaluated in the same manner. The evaluation results are shown in Table 1.

(Evaluation method: Tension adhesiveness)
Regarding the test method of tensile adhesiveness and the method of measuring the characteristics, it conforms to the NPO corporation housing exterior technical center standard "JTC S-0001 Ceramic siding sealant (2004)", and is 5.1.6 of the same standard. The described type I test piece was prepared and carried out. First, a siding board (Moen Siding M, manufactured by Nichiha Corporation) was cut into a size of 50 mm in length and 50 mm in width to prepare a first siding board and a second siding board. Then, the first siding board and the second siding board obtained by cutting are opposed to each other in the vertical direction at an interval of 10 mm, that is, the edge of the first siding board and the edge of the second siding board. The edges were fixed facing each other so that the distance between the edges was 10 mm. Then, a foamed polyethylene backup material having a length of 50 mm, a width of 10 mm, and a thickness of 6 mm is placed on the lower surface of the gap between the edge of the first siding board and the edge of the second siding board, and the first siding board and the first siding board are placed. The surface of the siding board of No. 2 was covered with masking tape. Then, the primer composition according to Example 1 is applied to the region in contact with the sealing material (that is, the edge of the first siding board and the edge of the second siding board), and the gap (joint) having an interval of 10 mm is sealed. After filling the material (POS seal LM super weather resistant, manufactured by Cemedine Co., Ltd.) to a thickness of 8 mm, the masking tape was removed to prepare a test sample.

Then, in order to evaluate the normal adhesiveness, the test sample was cured in an environment of 23 ° C. and 50% RH for 1 week, then cured in an environment of 30 ° C. for 1 week, and then pulled at a tensile speed of 50 mm / min in an environment of 23 ° C. Adhesion test was carried out. (“Tension Adhesiveness (Normal / Moen M)” in Table 1). Further, in order to evaluate the heat-resistant adhesiveness, another test sample was cured in an environment of 23 ° C. and 50% RH for 1 week, further cured in an environment of 30 ° C. for 1 week, and then cured in an environment of 80 ° C. for 2 weeks. Then, after each curing was completed, a tensile adhesiveness test was carried out in an environment of 23 ° C. at a tensile speed of 50 mm / min (“Tensile adhesiveness (80 ° C. 2w / Moen M)” in Table 1). Further, in order to evaluate the water resistance and adhesion, another test sample was cured in a 23 ° C. 50% RH environment for 1 week, further cured in a 30 ° C. environment for 1 week, and then immersed in warm water at 60 ° C. for 2 weeks. Then, after each curing was completed, a tensile adhesiveness test was carried out in an environment of 23 ° C. at a tensile speed of 50 mm / min (“Tensile adhesiveness (60 ° C. hot water 2w / Moen M)” in Table 1). In the tensile adhesiveness test, the load (MPa), the maximum load (T _max (MPa)), and the elongation rate (E _max (%)) at the maximum load were measured when the elongation rate was 50%. The "50% modulus" in Table 1 is the load when the elongation rate is 50%.

Other examples and comparative examples were evaluated in the same manner. The evaluation results are shown in Table 1.

As can be seen from Table 1, all of the primer compositions according to the examples are excellent in workability, joint adhesiveness, and barrier property, and the primer compositions according to the examples are also used for tensile adhesiveness under various conditions. If so, it was shown to exhibit good properties. By referring to Examples and Comparative Examples, it can be seen that the combination of the component (A) and the component (B) exhibits good workability, joint adhesiveness, and barrier property.

Although the embodiments and examples of the present invention have been described above, the embodiments and examples described above do not limit the invention according to the claims. In addition, not all combinations of features described in the embodiments and examples are indispensable for the means for solving the problems of the invention, and various kinds as long as they do not deviate from the technical idea of the present invention. It should be noted that it can be transformed.

Claims (4)

(A) A methyl methacrylate-based polymer having a proportion of methyl methacrylate contained in the resin of 80% by weight or more and a weight average molecular weight of 60,000 or more.
(B) A primer composition containing an alkoxysilyl group-containing methyl methacrylate-based polymer in which the proportion of methyl methacrylate contained in the resin is less than 80% by weight. (C) The primer composition according to claim 1, further comprising an amino group-containing silane. (D) The primer composition according to claim 1 or 2, further comprising an epoxy resin. (E) The primer composition according to any one of claims 1 to 3, further comprising a silane-based cross-linking agent.