JP7395087B2 - Primer composition - Google Patents

Description

The present invention relates to primer compositions.

Primer compositions are conventionally used to adhere architectural sealants to glass substrates. When the above-mentioned architectural sealing material is used around glass constituting a building, for example on the indoor side, sunlight or the like is irradiated through the glass onto the primer layer and the sealing layer.
Therefore, the primer composition used as described above is required to have weather resistance through glass (weather resistance through glass).

Until now, for example, Patent Document 1 has been proposed as a primer composition that has excellent adhesion to glass substrates and weather-resistant adhesion to glass and can be applied to various sealing materials.
Patent Document 1 describes a polymer (A) whose main chain contains an acrylic acid alkyl ester monomer unit and/or a methacrylic acid alkyl ester monomer unit and has at least one hydrolyzable silicon-containing group per molecule. A primer composition containing a silane coupling agent (B), and a solvent (C) is described.

Japanese Patent Application Publication No. 2005-281519

Under these circumstances, the present inventor prepared a primer composition containing a (meth)acrylic resin with reference to Patent Document 1 and evaluated it, and found that the weight average molecular weight or It has become clear that depending on the glass transition temperature, the weather resistance of the resulting primer layer through glass may not meet the level currently required.
It is thought that improving the weather resistance of the primer layer through glass will lead to a longer lifespan of the sealing layer.
Therefore, an object of the present invention is to provide a primer composition that has excellent weather resistance through glass.

As a result of intensive research to solve the above problems, the present inventor discovered that the primer composition
(A) a (meth)acrylic resin having a weight average molecular weight of 40,000 or more and 150,000 or less and a glass transition temperature of 40°C or more and 100°C or less;
(B) a polyisocyanate compound;
(C) a silane coupling agent;
(D) It has been found that the desired effect can be obtained by containing a solvent, and the present invention has been achieved.
The present invention is based on the above-mentioned findings, and specifically aims to solve the above-mentioned problems with the following configuration.

[1] (A) A (meth)acrylic resin having a weight average molecular weight of 40,000 or more and 150,000 or less and a glass transition temperature of 40°C or more and 100°C or less,
(B) a polyisocyanate compound;
(C) a silane coupling agent;
(D) A primer composition containing a solvent.
[2] The primer composition according to [1], wherein the polyisocyanate compound (B) contains an aliphatic and/or alicyclic polyisocyanate having an isocyanurate ring.
[3] The primer composition according to [1] or [2], wherein the silane coupling agent (C) has at least one functional group selected from the group consisting of a mercapto group, an amino group, and a ketimine group.
[4] The primer composition according to any one of [1] to [3], further containing (E) a silicate compound.
[5] The primer composition according to any one of [1] to [4], further containing (F) a curing catalyst.

The primer composition of the present invention has excellent weather resistance through glass.

The present invention will be explained in detail below.
In addition, in this specification, (meth)acrylate represents acrylate or methacrylate, (meth)acryloyl represents acryloyl or methacryloyl, and (meth)acrylic represents acrylic or methacrylic.
Further, in this specification, a numerical range expressed using "-" means a range that includes the numerical values written before and after "-" as lower and upper limits.
In this specification, unless otherwise specified, each component can be used alone or in combination of two or more of the substances corresponding to the component. When a component contains two or more types of substances, the content of the component means the total content of the two or more types of substances.
In this specification, unless otherwise specified, there is no particular restriction on the manufacturing method of each component. For example, conventionally known methods can be used. Moreover, commercially available products can be used as each component.
In this specification, (A) a (meth)acrylic resin having a weight average molecular weight of 40,000 or more and 150,000 or less and a glass transition temperature of 40°C or more and 100°C or less is simply referred to as "component (A)". It is sometimes called. The same applies to (B) the polyisocyanate compound, (C) the silane coupling agent, (D) the solvent, (E) the silicate compound, and (F) the curing catalyst.
In this specification, "the effect of the present invention is better" sometimes means that the weather resistance through glass is better.

[Primer composition]
The primer composition of the present invention (composition of the present invention) includes:
(A) a (meth)acrylic resin having a weight average molecular weight of 40,000 or more and 150,000 or less and a glass transition temperature of 40°C or more and 100°C or less;
(B) a polyisocyanate compound;
(C) a silane coupling agent;
(D) A primer composition containing a solvent.

Since the composition of the present invention has such a configuration, it is considered that the desired effect can be obtained. Although the reason is not clear, it is assumed to be as follows.
Component (A) contained in the composition of the present invention functions as a film-forming component (binder). It is thought that by having the weight average molecular weight of component (A) in the composition of the present invention, which is within the above-mentioned specific range, larger than that of the conventional composition, the weather resistance through glass of the resulting primer layer is improved.
On the other hand, (meth)acrylic resins containing hydrolyzable silicon-containing groups contained in conventional primer compositions have only relatively low weight average molecular weights from the viewpoint of production.
The present inventor also found that a primer composition containing a (meth)acrylic resin that does not have a hydrolyzable silicon-containing group and has a small weight average molecular weight has low weather resistance through glass.
From the above, the present inventors believe that a larger weight average molecular weight of the (meth)acrylic resin in the primer composition is better for the binder than for film formation by the hydrolyzable silicon-containing group of the (meth)acrylic resin. It is believed that the composition of the present invention improves its own weather resistance against sunlight, etc., and as a result, the composition of the present invention has excellent weather resistance through glass.
Each component contained in the composition of the present invention will be described in detail below.

<(A) (meth)acrylic resin>
(A) (meth)acrylic resin contained in the composition of the present invention has a weight average molecular weight of 40,000 or more and 150,000 or less, and a glass transition temperature of 40°C or more and 100°C or less (meth) It is an acrylic polymer.

The repeating units constituting the above component (A) preferably contain repeating units derived from monomers having a (meth)acryloyl group, from the viewpoint of superior effects of the present invention, and monomers having a (meth)acryloyloxy group. It is more preferable to contain a repeating unit derived from (meth)acrylic acid alkyl ester, and even more preferably to contain a repeating unit derived from a (meth)acrylic acid alkyl ester.

Examples of the (meth)acrylic acid alkyl esters include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, and n-acrylate. -Hexyl, heptyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, lauryl acrylate, tridecyl acrylate, myristyl acrylate, cetyl acrylate, stearyl acrylate, behenyl acrylate, Alkyl acrylates such as biphenyl acrylate;
Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, heptyl methacrylate, 2-ethylhexyl methacrylate , nonyl methacrylate, decyl methacrylate, undecyl methacrylate, lauryl methacrylate, tridecyl methacrylate, myristyl methacrylate, cetyl methacrylate, stearyl methacrylate, behenyl methacrylate, and biphenyl methacrylate.

The above (A) (meth)acrylic resin is preferably polyalkyl (meth)acrylate from the viewpoint of superior effects of the present invention,
More preferably, a (meth)acrylic resin formed from a monomer containing ethyl methacrylate, or a (meth)acrylic resin formed from a monomer containing butyl methacrylate and methyl methacrylate,
More preferred are (meth)acrylic resins formed from monomers containing butyl methacrylate and methyl methacrylate.

One preferable embodiment of the above (A) (meth)acrylic resin is that it does not have a functional group such as a hydrolyzable silyl group, silanol group, or hydroxyl group.
The above (A) (meth)acrylic resin is preferably composed only of repeating units derived from an alkyl (meth)acrylic acid ester, from the viewpoint of achieving better effects of the present invention.

<Weight average molecular weight>
In the present invention, the weight average molecular weight (Mw) of the component (A) is 40,000 or more and 150,000 or less.
Since the weight average molecular weight of the component (A) is 40,000 or more and 150,000 or less, the present invention has excellent weather resistance through glass.
Further, since the weight average molecular weight of the component (A) is 150,000 or less, the present invention has excellent adhesiveness to the base material (glass) and/or the sealing material.

The weight average molecular weight of the component (A) is preferably 50,000 to 120,000, from the viewpoint of achieving better effects of the present invention and excellent adhesion to the base material (glass) and/or sealing material. 000 to 120,000 is more preferable, and even more preferably 70,000 to 110,000.

In the present invention, component (A) was analyzed by gel permeation chromatography (GPC), and the weight average molecular weight of component (A) was calculated in terms of polystyrene under the following conditions.
・Device: GPC-8220 (manufactured by Tosoh Corporation)
- Columns: One G7000HXL/7.8mm ID, two GMHXL/7.8mm ID, and one G2500HXL/7.8mm ID were used.
・Medium: Tetrahydrofuran ・Flow rate: 1.0mL/min
・Concentration: 1.5mg/ml
・Injection volume: 300μL
・Column temperature: 40℃

<Glass transition temperature>
In the present invention, the glass transition temperature (Tg) of the component (A) is 40°C or more and 100°C or less.
Since the glass transition temperature of the component (A) is 40°C or more and 100°C or less, the present invention has excellent weather resistance through glass.
Further, since the glass transition temperature of the component (A) is within the above range, the primer layer obtained from the composition of the present invention has excellent mechanical strength and followability to the sealing layer.

The glass transition temperature of the above component (A) is preferably 45 to 95°C, more preferably 50 to 70°C, from the viewpoint of achieving better effects of the present invention and excellent mechanical strength of the primer layer and conformability to the sealing layer. preferable.

In the present invention, the glass transition temperature of component (A) can be measured using a differential scanning calorimeter (DSC).

(Content of (A) component)
The content of the above-mentioned component (A) is set to 100 parts by mass of the component (D) described below, from the viewpoint of achieving better effects of the present invention, and excellent adhesion and workability to the base material (glass) and/or sealing material. On the other hand, it is preferably 0.5 to 30 parts by weight, more preferably 1 to 20 parts by weight.

<(B) Polyisocyanate compound>
The polyisocyanate compound (B) (component (B)) contained in the composition of the present invention is not particularly limited as long as it has two or more isocyanate groups per molecule.
By containing the polyisocyanate compound (B), the composition of the present invention has excellent adhesiveness to a substrate (glass) and/or a sealing material.
The (B) components can react with each other. Moreover, the component (B) may react with the silane coupling agent (C) described below.

(Isocyanate group)
It is more preferable that the polyisocyanate compound (B) has three or more isocyanate groups per molecule, from the viewpoint of achieving the effects of the present invention and having excellent adhesion to the base material (glass) and/or sealing material. .
Isocyanate groups can be attached to hydrocarbon groups. The above hydrocarbon group is not particularly limited. Examples include aliphatic hydrocarbon groups (the concept includes linear or branched chains), alicyclic hydrocarbon groups, aromatic hydrocarbon groups, or combinations thereof. The hydrocarbon group may have a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom.

(B) As the polyisocyanate compound, for example, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), 1,4-phenylene diisocyanate, polymethylene polyphenylene polyisocyanate, xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate ( Aromatic polyisocyanate compounds such as TMXDI), toridine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), triphenylmethane triisocyanate;
Hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI), transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI, structure below), bis(isocyanatemethyl)cyclohexane (H _{6 _} (The above alicyclic is a concept that includes a cyclic aliphatic hydrocarbon group) or a polyisocyanate having a combination of an aliphatic hydrocarbon group and an alicyclic hydrocarbon group as the hydrocarbon group (in the case of the above combination) , the aliphatic hydrocarbon group may be a methylene group or a methyl group in addition to a linear or branched aliphatic hydrocarbon group);
Examples include these isocyanurate-modified polyisocyanates (polyisocyanates having an isocyanurate ring).

(isophorone diisocyanate)
Isophorone diisocyanate is a diisocyanate in which two isocyanate groups are bonded to a hydrocarbon group that is a combination of an alicyclic hydrocarbon group such as a cyclohexane ring and an aliphatic hydrocarbon group such as a methylene group or a methyl group. be.

(Isocyanurate ring)
The isocyanurate ring has a structure represented by the following formula (B1).
The above polyisocyanate compound (B) can have at least one of the above isocyanurate rings per molecule, which provides superior effects of the present invention and excellent adhesion to the base material (glass) and/or sealing material. It is preferable to have one isocyanurate ring.

When the polyisocyanate compound (B) has one isocyanurate ring, the polyisocyanate compound having the isocyanurate ring can have, for example, 1 to 3 isocyanate groups, and the effects of the present invention are more excellent. It is preferable to have three of them.
The isocyanurate ring and the isocyanate group can be bonded via a hydrocarbon group. The hydrocarbon groups capable of bonding the isocyanurate ring and the isocyanate group are each independently an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or a combination thereof ( In the case of the above combination, the aliphatic hydrocarbon group is preferably a methylene group or a methyl group in addition to a linear or branched aliphatic hydrocarbon group.
A polyisocyanate compound having an isocyanurate ring can be formed, for example, as a trimer of a diisocyanate compound having two isocyanate groups. The diisocyanate compounds used to form the isocyanurate ring may be the same or different.

The above component (B) is a polyisocyanate having an isocyanurate ring, an aliphatic polyisocyanate, or a resin, from the viewpoint of having better effects of the present invention and excellent adhesion to the base material (glass) and/or the sealing material. It preferably contains a cyclic polyisocyanate, more preferably an aliphatic and/or alicyclic polyisocyanate having an isocyanurate ring, and even more preferably an isocyanurate of isophorone diisocyanate.

In addition, "aliphatic and/or alicyclic" in the above-mentioned aliphatic and/or alicyclic polyisocyanate having an isocyanurate ring refers to the isocyanurate ring and the isocyanate group in the polyisocyanate having an isocyanurate ring. The intervening hydrocarbon groups are each independently an aliphatic hydrocarbon group (the above-mentioned aliphatic hydrocarbon group is a concept including linear or branched), an alicyclic hydrocarbon group, or a combination thereof ( Note that in the case of the above combination, the aliphatic hydrocarbon group may be a methylene group or a methyl group in addition to a linear or branched aliphatic hydrocarbon group.

((B) Content of polyisocyanate compound)
The content of the above-mentioned (B) polyisocyanate compound is determined based on 100 parts by mass of the above-mentioned (A) component from the viewpoint of achieving better effects of the present invention and excellent adhesion to the base material (glass) and/or sealing material. , preferably 200 to 400 parts by mass, more preferably 250 to 350 parts by mass.

In addition, the content of the polyisocyanate compound (B) is determined from the viewpoint that the effect of the present invention is excellent and the adhesiveness with the base material (glass) and/or sealing material and workability are excellent. It is preferably 5 to 40 parts by weight, more preferably 10 to 30 parts by weight, and even more preferably 13 to 17 parts by weight, based on 100 parts by weight.

<(C) Silane coupling agent>
The silane coupling agent (C) (component (C)) contained in the composition of the present invention is particularly limited as long as it is a compound having a hydrolyzable silyl group and a functional group (excluding the hydrolyzable silyl group). Not done.
By containing the silane coupling agent (C), the composition of the present invention has excellent adhesiveness to a substrate (glass) and/or a sealing material.
Component (C) may react with component (B) above.

-Functional group Examples of the functional group that the silane coupling agent (C) has include an epoxy group, an amino group, a mercapto group, a ketimine group, a (poly)sulfide group, a vinyl group, a (meth)acryloxy group, a carboxy group, Examples include isocyanate groups.
The above (C) silane coupling agent has a mercapto group (-SH), an amino group (-NH ₂ or -NH-) and a ketimine group (>C=N-).

The functional group is preferably a ketimine group from the viewpoint of having excellent long-term adhesion to the base material (glass) and/or the sealing material.
A ketimine group can be formed, for example, from a carbonyl group possessed by a ketone or an aldehyde and a compound having -NH ₂ . Also, the ketimine group can be decomposed into a ketone or aldehyde and a compound with -NH ₂ , for example in the presence of water or by heating.
One of the preferred embodiments is that the compound having --NH ₂ that can constitute a ketimine group further has a hydrolyzable silyl group. The above-mentioned -NH ₂ and the hydrolyzable silyl group can be bonded via an organic group. The above organic group is not particularly limited. For example, conventionally known ones can be mentioned.
The ketone or aldehyde that can constitute the ketimine group is not particularly limited. For example, conventionally known ones can be mentioned.

- Hydrolyzable silyl group The hydrolyzable silyl group that component (C) has is not particularly limited. For example, there may be mentioned a silyl group in which one to three hydrolyzable groups are bonded to one silicon atom.
The above-mentioned hydrolyzable group is not particularly limited, but an alkoxy group is particularly preferred.
The above-mentioned hydrolyzable silyl group is preferably a dialkoxysilyl group or a trialkoxysilyl group, and more preferably a trialkoxysilyl group, from the viewpoint of excellent adhesion to a substrate (glass) and/or a sealing material.
A portion of the hydrolyzable silyl group may be hydrolyzed to form a silanol group.

The above functional group and the hydrolyzable silyl group can be bonded via an organic group. The above organic group is not particularly limited.

Examples of the component (C) include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, and γ-ureidopropyltrimethoxysilane. , N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, N-phenyl- An amino group-containing silane coupling agent such as γ-aminopropyltrimethoxysilane;
Mercapto group-containing silane coupling agents such as γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane;
N-(1,3-dimethylbutylidene)-3-(trimethoxysilyl)-1-propanamine, N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)-1-propanamine, N-(1,3-dimethylbutylidene)-3-(methyldimethoxysilyl)-1-propanamine, N-(1,3-dimethylbutylidene)-3-(methyldiethoxysilyl)-1-propanamine Examples include ketimine group-containing silane coupling agents such as.

((C) Content of silane coupling agent)
The content of the above-mentioned (C) silane coupling agent is determined based on 100 parts by mass of the above-mentioned (A) component from the viewpoint of achieving better effects of the present invention and excellent adhesion to the base material (glass) and/or sealing material. The amount is preferably 100 to 300 parts by weight, more preferably 120 to 220 parts by weight.

In addition, the content of the silane coupling agent (C) mentioned above is determined from the viewpoint of the effect of the present invention, the adhesion to the base material (glass) and/or the sealing material, and the workability, as described in (D) below. The amount is preferably 0.1 parts by weight or more and 20 parts by weight or less, more preferably 3 to 15 parts by weight, and even more preferably 6 to 15 parts by weight, based on 100 parts by weight of the component.

<(D) Solvent>
The solvent (D) contained in the composition of the present invention is not particularly limited as long as it is a compound that is inert to other components and can dissolve or disperse them.
Specifically, for example, aromatic hydrocarbons such as benzene, xylene, and toluene; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; esters such as methyl acetate, ethyl acetate, and butyl acetate; diethyl ether, tetrahydrofuran, and dioxane. Examples include ethers such as. In addition, it is preferable to use the solvent (D) after sufficiently drying or dehydrating it.
(D) The solvent is preferably ethyl acetate or toluene from the viewpoints of low boiling point and excellent drying properties.

((D) Solvent content)
The content of the above-mentioned (D) solvent is not particularly limited, but it is preferably 50 to 90% by mass based on the total amount of the primer composition, since the coating properties and adhesive properties of the primer composition are good.

((E) Silicate compound)
The composition of the present invention preferably further contains (E) a silicate compound (component (E)) from the viewpoint of having excellent adhesiveness to the substrate (glass).

(E) The silicate compound is not particularly limited as long as it is a silicate ester or a condensate thereof.
Examples of the silicic acid ester include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, and tetrapropoxysilane;
Trialkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, and methyltripropoxysilane may be mentioned.

(E) The silicate compound preferably contains a condensate of silicate ester, and preferably contains a condensate of tetraalkoxysilane, from the viewpoint of achieving better effects of the present invention and excellent adhesion to the base material (glass). is more preferable.

((E) Content of silicate compound)
The content of the silicate compound (E) is 20 to 100 parts by mass based on 100 parts by mass of the component (A) from the viewpoint of achieving better effects of the present invention and excellent adhesion to the base material (glass). The amount is preferably 30 to 80 parts by mass, and more preferably 30 to 80 parts by mass.

In addition, the content of the silicate compound (E) is determined based on 100 parts by mass of the component (D), from the viewpoint of the effect of the present invention and the adhesion to the base material (glass) and workability. The amount is preferably 0.1 parts by mass or more and 10 parts by mass or less, and more preferably 0.5 to 5 parts by mass.

((F) Curing catalyst)
The composition of the present invention further contains (F) a curing catalyst (component (F)) from the viewpoint of being superior to the effects of the present invention and having excellent adhesion to the base material (glass) and/or the sealing layer. It is preferable.
(F) The curing catalyst is not particularly limited as long as it is a catalyst that promotes curing of the (B) polyisocyanate compound.
(F) Examples of the curing catalyst include tertiary amine compounds, carboxylic acid metal salts, metal alkoxides, and metal chelates.
Among these, it is preferable that the curing catalyst (F) contains a carboxylic acid metal salt from the viewpoint of being more effective in the present invention and having excellent adhesion to the base material (glass) and/or the sealing layer.

Specifically, the above-mentioned tertiary amine compounds include, for example, N,N,N',N'-tetramethylpropylenediamine, N,N-dimethylbenzylamine, triethylenediamine, pentamethylenediethylenetriamine, and morpholine amine. , triethylamine, and the like.

The carboxylic acid that can constitute the carboxylic acid metal salt is not particularly limited as long as it is a hydrocarbon compound having a carboxy group.
Specific examples of the carboxylic acid metal salts include carboxylic acid salts of tin, zinc, bismuth, zirconium, cobalt, calcium, or cerium.
Among these, it is preferable to contain a tin carboxylate salt, and it is preferable to contain stannous octylate, from the viewpoint of superior effects of the present invention and excellent adhesion to the base material (glass) and/or the sealing layer. is more preferable.

Examples of the metal alkoxides include titanium or zirconium alkoxides, specifically, for example, tetrapropoxytitanium or tetrabutoxytitanium, and condensates thereof.
Examples of the metal chelate include chelates of titanium, aluminum, zirconium, iron, cobalt, etc., and more specifically, aluminum acetylacetonate.

((F) Content of curing catalyst)
The content of the curing catalyst (F) is determined based on 100 parts by mass of the component (A) from the viewpoint of achieving better effects of the present invention and excellent adhesion to the base material (glass) and/or the sealing layer. It is preferably 10 to 50 parts by weight, more preferably 15 to 30 parts by weight.

In addition, the content of the curing catalyst (F) is set to 100% by mass of the component (D) from the viewpoint of achieving better effects of the present invention, excellent adhesion to the base material (glass) and/or sealing layer, and workability. The amount is preferably 0.001 to 10 parts by weight, more preferably 0.05 to 5 parts by weight.

The primer composition of the present invention may contain, for example, a filler, a plasticizer, a thixotropic agent, a dehydrating agent, a softener, a stabilizer, a coloring agent, an anti-sagging agent, a physical property modifier, within a range that does not impair the characteristics of the present invention. Additives such as flame retardants, reinforcing agents, anti-aging agents, antioxidants, dyes, pigments, etc. may also be included.

(Method for producing the primer composition of the present invention)
The primer composition of the present invention can be manufactured by mixing the above-mentioned components. The mixing method is not particularly limited, and conventionally known methods can be used. For example, a method using a ball mill may be mentioned.

(how to use)
The method of using the primer composition of the present invention is the same as that for ordinary primer compositions. That is, the primer composition of the present invention may be applied to a substrate, dried, and then a sealant may be applied and bonded using a conventional method.
The method of applying the primer composition of the present invention to a substrate, drying conditions, etc. are not particularly limited. When drying the primer composition of the present invention, the primer composition of the present invention can be dried, for example, by leaving it under room temperature conditions or by heating it.

(Base material)
The substrate to which the composition of the present invention is applied is not particularly limited, but is preferably glass. The glass to which the composition of the present invention can be applied is not particularly limited.
(sealing material)
The sealant applied to the composition of the present invention is not particularly limited. Examples include architectural sealants. The above-mentioned sealing material is preferably a (meth)acrylic sealing material from the viewpoint of adhesiveness with the primer composition of the present invention. The (meth)acrylic sealant is not particularly limited. For example, conventionally known ones can be mentioned. Specifically, for example, a sealing material composition containing a (meth)acrylic resin or the like having a reactive group can be mentioned.

EXAMPLES The present invention will be specifically described below with reference to Examples. However, the present invention is not limited to these.

<Manufacture of primer composition>
Each component in Table 1 below was used in the composition (parts by mass) shown in the same table, and these were mixed with a stirrer to produce each primer composition.

<Evaluation>
The following evaluations were performed using each primer composition manufactured as described above. The results are shown in Table 1.
(Preparation of initial test specimen)
An initial test specimen was prepared according to JIS A1439:2016 using anodized aluminum and float glass as adherends.
- Formation of primer layer Each primer composition produced as described above was applied to the surface of float glass and dried for 1 hour at 23° C. to form a primer layer.

- Sealing material The following two-component silylated (meth)acrylate sealing material was used as the sealing material applied on the primer layer formed as described above. The formulation of the two-component silylated (meth)acrylate sealant is as follows.
(Composition of two-component silylated (meth)acrylate sealant)
- Polymer (A): terminal-reactive liquid acrylic resin. XMAP SA-410S Manufactured by Kaneka. 50 parts by mass Polymer (B): Polyoxypropylene having trimethoxysilyl groups at both ends. MSP-S203H Manufactured by Kaneka. 50 parts by mass, plasticizer: DINP (diisononyl phthalate) manufactured by J-Plus Co., Ltd. 70 parts by mass Anti-aging agent: Tinuvin 326 manufactured by BASF Japan. 4 parts by mass of heavy calcium carbonate: Super SS manufactured by Maruo Calcium Co., Ltd. 40 parts by mass Colloidal calcium carbonate: Shiroenka CCR Manufactured by Shiroishi Kogyo Co., Ltd. 125 parts by mass / Curing catalyst: Nikka Octix tin (28%) manufactured by Nihon Kagaku Sangyo Co., Ltd. 5 parts by mass Laurylamine: Firmin 20D manufactured by Kao Corporation. 0.5 parts by mass

・Curing of sealant A Type 2 test specimen prepared in accordance with JIS A 1439:2016 was cured at 23°C and 50% RH (relative humidity) for 7 days, and then further cured at 50°C for 7 days to obtain the initial test specimen. was created.

(Accelerated weathering test)
Using each of the initial test specimens prepared as described above, an accelerated weathering test (metal weather test) was conducted on the float glass surface of each initial test specimen.

The metal weather test conditions are as follows. The time required for the metal weather test (unit: hours) is shown in Table 1 using notations such as "250 hours".
Illuminance: 75mW/ ^cm2
Light source: Metal halide lamp Temperature, humidity: 63℃, 50%RH (relative humidity)
Shower: 120sec/2h

(Tensile test)
Using the initial test specimen obtained as described above and the test specimen after the accelerated weathering test, a tensile test was conducted according to JIS A 1439:2016, and the fracture state after the tensile test was visually evaluated.
In Table 1, "CF" represents cohesive failure of the sealing layer, "TCF" represents thin layer failure of the sealing layer, and "AF" represents interfacial peeling between the sealing layer and the float glass.
The numerical value after "CF" is the ratio (%) that "CF" occupies with respect to the entire adhesive area. The same applies to the values after "TCF" and "AF".

(Evaluation criteria for weather resistance through glass)
In the present invention, the weather resistance through glass was evaluated based on the fracture state after the tensile test of the test specimen after the accelerated weather resistance test.
In the present invention, when the fracture state of the test piece after 500 hours (after 500 hours) of the metal weather test was the same as the initial adhesion (CF100), it was evaluated that the weather resistance through glass was excellent.
In addition, even if the time required for the metal weather test is longer than 500 hours (for example, after 750 hours or 1000 hours), if the failure condition remains the same as the initial adhesion (CF100), the weather resistance through glass is It was rated as better.
On the other hand, when the fracture state of the test specimen after 500 hours of the metal weather test included CF and TCF or AF, the weather resistance through glass was evaluated as poor.

Details of each component shown in Table 1 are as follows. In addition, Mw refers to the weight average molecular weight, and Tg refers to the glass transition temperature.
<(A) (meth)acrylic resin>
The following (meth)acrylic resins A-1 to A-4 correspond to component (A) in the present invention. (Meth)acrylic resins A-1 to A-4 do not have functional groups such as hydrolyzable silyl groups, silanol groups, and hydroxyl groups. Further, (meth)acrylic resins A-1 to A-4 are composed only of repeating units derived from (meth)acrylic acid alkyl ester.
- (Meth)acrylic resin A-1: Product name B-813, manufactured by DSM. Mw=40,000, Tg=64°C. (Meth)acrylic resin formed from monomers containing ethyl methacrylate.
- (Meth)acrylic resin A-2: Product name MB-2660, manufactured by Mitsubishi Chemical Corporation. Mw=60,000, Tg=63℃
- (Meth)acrylic resin A-3: Product name B-734, manufactured by DSM. Mw=105,000, Tg=60°C. (Meth)acrylic resin formed from monomers including butyl methacrylate and methyl methacrylate.
- (Meth)acrylic resin A-4: Product name BR-82, manufactured by Mitsubishi Chemical Corporation. Mw=140,000, Tg=100℃

The following acrylic resins A-5 to A-9 do not fall under component (A) in the present invention because their Mw or Tg is outside the predetermined range.
- Acrylic resin A-5: Product name B-864, manufactured by DSM. Mw=160,000, Tg=65°C. (Meth)acrylic resin formed from monomers containing isobutyl methacrylate.
- Acrylic resin A-6: Product name B-891, manufactured by DSM. Mw=35,000, Tg=77°C. (Meth)acrylic resin formed from monomers including butyl methacrylate and methyl methacrylate.
- Acrylic resin A-7: Product name B-811, manufactured by DSM. Mw=40,000, Tg=110°C. (Meth)acrylic resin formed from monomers containing methyl methacrylate.
- Acrylic resin A-8: Product name BR-117, manufactured by Mitsubishi Chemical Corporation. Mw=140,000, Tg=34℃

- Urethane resin: Dismocol 406, manufactured by Sumika Covestro Urethane Co., Ltd.
・Epoxy resin: Bisphenol A type epoxy resin. Trade name: Epotote YD-013, manufactured by Nippon Steel Chemical & Materials Co., Ltd. Acrylic resin A-9: (meth)acrylic resin having a hydrolyzable silyl group. Product name: XMAP SA-100S, manufactured by Kaneka Corporation. Mw=25,000

(D) Solvent: Ethyl acetate (B) Polyisocyanate compound: Isocyanurate of isophorone diisocyanate. Product name: Duranate TPA-100, manufactured by Asahi Kasei Corporation.
(E) Silicate compound: condensate of tetraalkoxysilane. Product name: MKC Silicate MS51, manufactured by Mitsubishi Chemical Corporation.
(C) Silane coupling agent: 3-mercaptopropyltrimethoxysilane. Trade name: KBM-803, manufactured by Shin-Etsu Chemical Co., Ltd. (F) Curing catalyst: stannous octylate. Product name: Stanoct, manufactured by Mitsubishi Chemical Corporation

As is clear from the results shown in Table 1, Comparative Examples 1 to 4 and 7 in which the weight average molecular weight or glass transition temperature of the (meth)acrylic resin was outside the predetermined range had poor weather resistance through glass.
Comparative Examples 5 and 6, which did not contain component (A) but contained urethane resin or epoxy resin instead, had poor weather resistance through glass.

In contrast, the primer composition of the present invention had excellent weather resistance through glass.

Claims (2)

(A) a (meth)acrylic resin having a weight average molecular weight of 40,000 or more and 150,000 or less, a glass transition temperature of 40°C or more and 100°C or less , and having substantially no hydroxyl groups ;
(B) a polyisocyanate compound;
(C) a silane coupling agent;
(D) A one-component primer composition containing a solvent. The polyisocyanate compound (B) contains an aliphatic and/or alicyclic polyisocyanate having an isocyanurate ring,
The silane coupling agent (C) has at least one functional group selected from the group consisting of a mercapto group, an amino group, and a ketimine group,
The primer composition according to claim 1 , further comprising (E) a silicate compound and (F) a curing catalyst .