JP5476658B2 - Primer composition that can be ejected in foam and primer construction method using the same - Google Patents

Description

  The present invention relates to a primer composition that can be ejected in a foam shape useful for construction in waterproofing work such as architecture and civil engineering, and a primer construction method using the same.

Conventionally, in waterproofing work and sealing work to maintain airtightness, prior to the construction of waterproofing material and sealing material, mainly improve the adhesion between the waterproofing material and sealing material and the base material, waterproofing and airtightness Primer application work to a base material for holding the surface is widely performed. In particular, in the field of architecture and civil engineering, a sealing material is mainly constructed for the purpose of waterproofing. When this sealing material is constructed, for example, concrete, aluminum sash, etc. In order to further strengthen the adhesiveness to the substrate, a substrate to be an adherend is treated with a primer. In addition, even if the sealing material itself has good adhesion, the groundwork such as concrete and sash may be dirty with chips and dust, and if the groundwork is insufficiently cleaned, poor adhesion will occur. In order to prevent this, primer treatment is required (see Patent Document 1). Although it is a primer application work widely performed in this way, the part where the application work is performed may be a flat surface, a curved surface, a concave shape, a groove shape, a step shape, etc. In addition, there are many cases where the base material such as a flat shape, a concave shape, a groove shape, and a step shape is vertical, and there are some places where it is difficult to apply. A liquid primer in which a resin, various additives, and the like are dissolved or dispersed in an organic solvent or water is applied to such a portion with a brush, a roller, a spray, or the like. It is good if the part to be applied is flat and horizontal, but if it is curved, concave, grooved, stepped, etc., it may be difficult to paint, leaving unpainted, If the brush is moved too quickly in brush coating or the like, there may be a portion where the primer solution is not on the base, or a so-called coating unevenness in which the primer solution is small even if it is placed. Furthermore, if it is vertical or curved, the liquid primer may sag (run down), and the sag primer may be wiped off after the work so that it does not cause subsequent contamination. Thus, although it is primer construction to secure the adhesion between the waterproofing material or sealing material and the adherend that is the base, it is difficult to ensure stable adhesion due to uneven coating, unpainted, etc. There is. In addition, the liquid primer may become sagging, and dust or the like may adhere to it, become dirty, or change color after being cured, which may cause problems in design (see Patent Document 2).
Japanese Unexamined Patent Publication No. 64-43576 JP-A-4-148862

  The purpose of the present invention is to prevent coating unevenness and coating leakage in the primer coating operation to ensure stable adhesion to the base material of waterproofing material or sealing material, and to suppress foaming due to thick coating application and adhesion And a primer composition that can be ejected in the form of a foam capable of performing efficient work with excellent workability by suppressing dripping during application work and contamination due to scattering to the surroundings. It is to provide a primer construction method.

In order to achieve the object, the present invention includes the following (1) to ( 5 ).
(1) A primer composition containing a resin (A1), a solvent (A2), a surfactant (A3), and a propellant (B), which can be ejected in a foam shape, wherein the resin (A1) is an isocyanate A group-containing urethane-based prepolymer or a crosslinkable silyl group-containing resin, wherein the solvent (A2) is an organic solvent, and the surfactant (A3) is a fluorine-based nonionic surfactant. Primer composition that can be ejected in the form of foam.
(2) The primer composition that can be ejected in the form of foam (1), wherein the solvent (A2) is an organic solvent that is not reactive with an isocyanate group-containing urethane prepolymer or a crosslinkable silyl group-containing resin.
(3) The propellant (B) contains at least one selected from the group consisting of dimethyl ether, carbon dioxide, nitrogen, nitrous oxide, petroleum gas (LPG), propane, isobutane and n-butane. The primer composition which can be ejected in the foam shape of (1) or (2).
(4) The primer composition which further contains an additive and can be ejected in the foam of any one of (1) to (3).
(5) The primer composition that can be jetted out in the form of a foam according to any one of (1) to (4) is sprayed in a foamy form on a work part of an adherend, and is coated and cured. Primer construction method.

  According to the present invention, it is possible to prevent application unevenness and application leakage in the primer application work to ensure stable adhesion to a base material of a waterproof material or a seal material, and to suppress foaming due to thick coating application and to adhere Further, it is possible to prevent deterioration of the liquid and to prevent the liquid from dripping at the time of the coating operation and the contamination due to scattering to the surroundings, and to achieve an excellent effect that an efficient operation with excellent workability can be performed.

The present invention will be described in detail below.
Specifically, the resin (A1) constituting the primer (A) in the present invention is an isocyanate group-containing urethane prepolymer or a crosslinkable silyl group-containing resin that is excellent in workability .

An isocyanate group-containing urethane-based prepolymer is a compound that contains at least one isocyanate group in a molecule that reacts with moisture to form a urea bond to crosslink and cure, and specifically includes an organic isocyanate and an active hydrogen described later. It is obtained by reacting a group-containing compound with an isocyanate group in excess.
Examples of organic isocyanates include organic polyisocyanates and mixtures of organic polyisocyanates and organic monoisocyanates. Specific examples of organic polyisocyanates include 2,4-toluene diisocyanate and 2,6-toluene diisocyanate. Toluene diisocyanates, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate and other diphenylmethane diisocyanates, 1,2-phenylene diisocyanate, 1,3-phenylene diisocyanate, 1, Phenylene diisocyanates such as 4-phenylene diisocyanate, 2,4,6-trimethylphenyl-1,3-diisocyanate, 2,4,6-triisopropyl Naphthalene diisocyanates such as phenyl-1,3-diisocyanate, 1,4-naphthalene diisocyanate, 1,5-naphthalene diisocyanate, chlorophenylene-2,4-diisocyanate, 4,4'-diphenyl ether diisocyanate, 3,3'-dimethyl Aromatic diisocyanates such as diphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate, 1,6-hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2,2,4 -Aliphatic diisocyanates such as trimethyl-1,6-hexamethylene diisocyanate, 2,4,4-trimethyl-1,6-hexamethylene diisocyanate, decamethylene diisocyanate, lysine diisocyanate , Aliphatic diisocyanates such as xylylene diisocyanates such as o-xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, 1,4-cyclohexyl diisocyanate, isophorone diisocyanate, hydrogenated toluene diisocyanate, hydrogenated xylylene Examples include alicyclic diisocyanates such as range isocyanate and hydrogenated diphenylmethane diisocyanate. Furthermore, organic polyisocyanates such as polymethylene polyphenyl polyisocyanate and crude toluene diisocyanate can also be used. In addition, modified isocyanates containing one or more uretdione bonds, isocyanurate bonds, allophanate bonds, burette bonds, uretonimine bonds, carbodiimide bonds, urethane bonds, urea bonds and the like obtained by modifying these organic polyisocyanates can also be used.
Organic monoisocyanates include organic compounds such as n-butyl monoisocyanate, n-hexyl monoisocyanate, n-hexadecyl monoisocyanate, n-octadecyl monoisocyanate, p-isopropylphenyl monoisocyanate, and p-benzyloxyphenyl monoisocyanate. A monoisocyanate is mentioned.
Any of these may be used alone or in combination of two or more.

As active hydrogen group-containing compounds, polyols, polyamines, or known active hydrogen group-containing compounds such as monools and monoamines can be used for modification of isocyanate group-containing urethane prepolymers. The number average molecular weight of the active hydrogen group-containing compound is preferably 100 or more, more preferably 100 to 10,000, and particularly preferably 200 to 3,000. When the number average molecular weight is less than 100, the elongation of the obtained primer is deteriorated, and when it exceeds 10,000, the viscosity becomes too high, which is not preferable. Specific examples include polyester polyols, polyester amide polyols, polycarbonate polyols, polyether polyols, polyolefin polyols, acrylic polyols, and animal and plant polyols.
Any of these may be used alone or in combination of two or more.
Of these, polyether polyols are preferred because of their excellent workability, adhesion, water resistance, weather resistance, and the like.

Examples of the polyester polyol include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, naphthalenedicarboxylic acid, and trimellitic acid. One or more of polycarboxylic acid such as acid, acid ester or acid anhydride, and ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butane Diol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonane Diol, diethylene glycol, dipropylene glycol, 1 4-cyclohexanedimethanol, ethylene oxide or propylene oxide adduct of bisphenol A, low molecular alcohols such as trimethylolpropane, glycerin and pentaerythritol, low molecular amines such as hexamethylenediamine, xylylenediamine and isophoronediamine, mono Examples thereof include polyester polyols or polyester amide polyols obtained by a dehydration condensation reaction with one or more low molecular amino alcohols such as ethanolamine and diethanolamine.
Also, for example, lactone polyester polyols obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone using low molecular alcohols, low molecular amines, and low molecular amino alcohols as initiators. Is mentioned.

  Examples of the polycarbonate polyol include dehydrochlorination reaction of low molecular alcohols and phosgene used in the synthesis of the polyester polyol described above, or esters of the low molecular alcohols with diethylene carbonate, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and the like. What is obtained by an exchange reaction is mentioned.

Examples of polyether polyols include ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran, etc. using low molecular alcohols, low molecular amines, and low molecular amino alcohols used in the synthesis of the above-described polyester polyol as initiators. Polyoxyethylene polyols, polyoxypropylene polyols, polytetramethylene ether polyols, polyether polyols obtained by copolymerizing these, and polyester ether polyols using the above-described polyester polyols and polycarbonate polyols as initiators. In addition, polyoxyalkylene monools obtained by ring-opening polymerization of propylene oxide or the like to monoalcohols (initiators) such as methyl alcohol, ethyl alcohol, and propyl alcohol are also used for modification of isocyanate group-containing urethane prepolymers. it can.
Of these, polyoxypropylene polyol is particularly preferable.

  Examples of the polyolefin polyol include hydroxyl group-containing polybutadiene, hydrogenated hydroxyl group-containing polybutadiene, hydroxyl group-containing polyisoprene, hydrogenated hydroxyl group-containing polyisoprene, hydroxyl group-containing chlorinated polypropylene, and hydroxyl group-containing chlorinated polyethylene.

  As the acrylic polyol, for example, a monomer of an acrylic acid compound containing a hydroxyl group such as 2-hydroxyethyl acrylate, hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, and / or methacryl containing a hydroxyl group. Batch polymerization or continuous polymerization of an acid-based compound monomer and one or more other ethylenically unsaturated compounds in the presence or absence of a radical polymerization initiator and in the presence or absence of a solvent What is obtained by making it react by well-known radical polymerization methods, such as superposition | polymerization, is mentioned.

  Examples of animal and plant polyols include castor oil-based diols.

  Moreover, if it has an active hydrogen group, for example, in addition to dimer acid diol and hydrogenated dimer acid diol, epoxy resin, polyamide resin, polyester resin, rosin resin, urea resin, melamine resin, phenol resin, Resins such as coumarone resin and polyvinyl alcohol can also be used as the polymer polyol.

  For the synthesis of an isocyanate group-containing urethane-based prepolymer, a salt of a metal such as zinc, tin, lead, zirconium, bismuth, cobalt, manganese, iron and the like and an organic acid such as octylic acid and naphthenic acid, such as zinc octenoate, Known urethanization catalysts such as salts of organic metals and organic acids such as dibutyltin dilaurate and dioctyltin dilaurate, organic amines such as triethylenediamine, triethylamine and tri-n-butylamine and salts thereof can be used. Of these, dibutyltin dilaurate is preferred. Further, a known organic solvent can also be used.

  The isocyanate group-containing urethane prepolymer can be synthesized by either a batch charge reaction method or a multistage charge reaction method, but it is necessary to leave an isocyanate group in the molecule of the prepolymer. The equivalent ratio of isocyanate group / active hydrogen group between the isocyanate group of the organic isocyanate and the active hydrogen group of the active hydrogen group-containing compound is preferably 1.1 to 5.0, more preferably 1.3 to 2.0. The isocyanate group-containing urethane prepolymer thus obtained preferably has an isocyanate group content of 0.1 to 15.0 mass%, particularly preferably 0.3 to 10.0 mass%, most preferably 0.5. -6.0 mass%. When the isocyanate group content is less than 0.1% by mass, the molecular weight becomes too large, the viscosity increases, and the workability decreases. Moreover, since there are few crosslinking points in resin, sufficient adhesiveness cannot be obtained. When the isocyanate group content exceeds 15.0 mass%, the molecular weight of the resin is too small, the rubber elasticity is deteriorated, and foaming occurs due to generation of carbon dioxide gas.

  Examples of the crosslinkable silyl group-containing resin include those generally called silicone resins and modified silicone resins, and react with moisture or (condensation) polymerization with a curing agent to form a siloxane bond. It is a resin containing 0.5 or more crosslinkable silyl groups in the molecule that forms a rubber-like cured product by cross-linking. Among these, a modified silicone resin containing 0.5 or more crosslinkable silyl groups in the molecule is preferable.

The silicone resin has an organopolysiloxane in the main chain and contains 0.5 or more crosslinkable silyl groups in the molecule.
Specifically, a one-part silicone resin containing an organopolysiloxane having a silanol group at the terminal as a main component and a low-molecular compound containing a crosslinkable silyl group as a crosslinking component, and an organopolysiloxane having a silanol group at the terminal as a main component A typical example is a two-part silicone resin containing siloxane and an aminoxyalkylsilane as a curing agent. Examples of the crosslinkable silyl group-containing low molecular weight compound include acyloxyalkylsilane, aminoxyalkylsilane, and alkoxyalkylsilane.

As the modified silicone resin, for example, JP-A-52-73998, JP-A-55-9669, JP-A-59-122541, JP-A-60-6747, JP-A-61-233043 JP-A-63-112642, JP-A-3-79627, JP-A-4-283259, JP-A-5-70531, JP-A-5-287186, JP-A-11-80571. Examples disclosed in Japanese Patent Laid-Open Nos. 11-116763 and 11-130931 can be given. Specifically, the main chain contains 0.5 or more crosslinkable silyl groups in the molecule and the main chain is a polyoxyalkylene polymer, a vinyl-modified polyoxyalkylene polymer, a vinyl polymer, polyisoprene or polyisoprene. Diene polymers such as butanediene, polyester polymers, acrylic and / or methacrylic (hereinafter referred to as (meth) acrylic) acid ester polymers, polysulfide polymers, copolymers thereof, any two or more And the like.
The main chain of the modified silicone resin is preferably a polyoxyalkylene polymer and / or a vinyl-modified polyoxyalkylene polymer, from the viewpoint of physical properties such as tensile adhesion after curing and modulus, and a polyoxypropylene polymer and A (meth) acryl-modified polyoxypropylene polymer is more preferable. Here, the modification includes not only a modification by copolymerization or reaction but also a blend.

It is preferable that 0.5-5 crosslinkable silyl groups are contained in a molecule | numerator from points, such as the sclerosis | hardenability of a primer, and the physical property after hardening.
Further, the crosslinkable silyl group is preferably one represented by the following general formula (1) which is easy to crosslink and easy to produce.

（式中、Ｒは炭化水素基であり、炭素数１〜２０のアルキル基、炭素数６〜２０のアリール基又は炭素数７〜２０のアラルキル基が好ましく、メチル基が最も好ましい。Ｘで示される反応性基はハロゲン原子、水素原子、水酸基、アルコキシ基、アシルオキシ基、ケトキシメート基、アミド基、酸アミド基、メルカプト基、アルケニルオキシ基及びアミノオキシ基より選ばれる基であり、Ｘが複数の場合には、Ｘは同じ基であっても異なった基であってもよい。このうちＸはアルコキシ基が好ましく、メトキシ基又はエトキシ基が最も好ましい。ａは０、１又は２の整数であり、０又は１が最も好ましい。）

Wherein R is a hydrocarbon group, preferably an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms, and most preferably a methyl group. The reactive group is a group selected from a halogen atom, a hydrogen atom, a hydroxyl group, an alkoxy group, an acyloxy group, a ketoximate group, an amide group, an acid amide group, a mercapto group, an alkenyloxy group, and an aminooxy group. In this case, X may be the same group or different groups, among which X is preferably an alkoxy group, most preferably a methoxy group or an ethoxy group, and a is an integer of 0, 1 or 2. , 0 or 1 is most preferred.)

Introduction of the crosslinkable silyl group into the main chain can be performed, for example, by the following known method.
(1) A polyoxyalkylene polymer having a functional group such as a hydroxyl group at the terminal is reacted with an organic compound (for example, allyl isocyanate) having an active group and an unsaturated group that are reactive with the functional group, and then Then, hydrosilylation is carried out by allowing hydrosilane having a hydrolyzable group to act on the obtained reaction product.
(2) A compound having a functional group and a crosslinkable silyl group reactive to this functional group to a polyoxyalkylene polymer having a functional group such as a hydroxyl group, an amino group, an epoxy group or an isocyanate group at the terminal. React.
Examples of the compound having a reactive functional group and a crosslinkable silyl group include amino group-containing silanes, mercapto group-containing silanes, epoxy group-containing silanes, vinyl type unsaturated bond-containing silanes, chlorine atom-containing silanes, and isocyanates. Examples thereof include group-containing silanes and hydrosilanes.
(3) A compound having a polymerizable unsaturated bond and a crosslinkable silyl group (for example, CH ₂ ═CHSi (OCH ₃ ) ₃ ) and a (meth) acrylic acid alkyl ester monomer are copolymerized.
(4) A compound having a polymerizable unsaturated bond and a functional group (for example, hydroxyethyl (meth) acrylate) is added to a (meth) acrylic acid alkyl ester monomer for copolymerization, and then the resulting copolymer is the above-mentioned copolymer compounds having a reactive functional group and a crosslinking silyl group (e.g., an isocyanate group and a -Si (OCH ₃₎ compounds having ₃ group) Ru reacted with.

As the solvent (A2) constituting the primer (A) in the present invention, specifically, Ri organic solvent der dissolving or dispersing the resin (A1), it has a reactive resin having a reactive functional group Organic solvents that are not suitable are further used to adjust the viscosity to be suitable for the coating operation or to have permeability to the adherend that is the base material. Specifically, for example, alcohol solvents such as ethanol, n-propanol, isopropanol, butanol, n-hexanol, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-pentanone, ethyl acetate, propyl acetate, acetic acid Ester solvents such as butyl, ether solvents such as diethyl ether and dipropyl ether, aliphatic hydrocarbon solvents such as n-hexane and n-heptane, aromatic hydrocarbon solvents such as toluene, xylene and ethylbenzene, cyclohexane And alicyclic hydrocarbon solvents such as industrial gasoline, mineral spirits, ligroin, kerosene and other petroleum solvents . These may be used alone or in combination of two or more.
Among these, when an isocyanate group-containing urethane prepolymer is used as the resin (A1), a ketone solvent, an ester solvent, an ether solvent, an aliphatic hydrocarbon solvent, an aromatic hydrocarbon solvent, an alicyclic group. Hydrocarbon solvents, petroleum solvents, and the like can be suitably used, but ketone solvents and ester solvents are preferable in terms of solubility, dispersibility, or safety, and methyl ethyl ketone and ethyl acetate are more preferable. .
When a crosslinkable silyl group-containing resin is used as the resin (A1), an alcohol solvent, a ketone solvent, an ester solvent, an ether solvent, an aliphatic hydrocarbon solvent, an aromatic hydrocarbon solvent, an alicyclic carbonization Hydrogen-based solvents, petroleum-based solvents, and the like can be suitably used, but alcohol-based solvents, ketone-based solvents, and ester-based solvents are preferable from the viewpoint of excellent solubility, dispersibility, or safety, and methanol, ethanol , Methyl ethyl ketone, and ethyl acetate are preferred.
The solvent (A2) is preferably blended in an amount of 10 to 20,000 parts by weight, more preferably 100 to 10,000 parts by weight, and particularly preferably 100 to 2,000 parts by weight with respect to 100 parts by weight of the resin (A1). When it exceeds 20,000 parts by mass, the effect as a primer is remarkably reduced.

The surfactant (A3) constituting the primer (A) in the present invention is used for forming bubbles (including fine bubbles and having fluidity or non-fluidity, emulsion bubbles). Specifically, it is a fluorine-based nonionic surfactant such as a perfluoroalkyl compound (manufactured by AGC Seimi Chemical Co., Surflon 381, Surflon 386, Surflon 393) .

Surfactants constituting the primer (A) in this onset bright (A3) is 0.01 to 15.0% by weight of the total composition, preferably from 0.1 to 10.0 wt%, well in this range It can be applied in the form of foam.

The propellant (B) in the present invention may be any liquefiable gas usually used for aerosol (spray), and various conventionally known ones can be used. Specifically, dimethyl ether, carbon dioxide, nitrogen, nitrous oxide, petroleum gas (LPG), propane, isobutane, and n-butane can be preferably exemplified. These can be used alone or in admixture of two or more.
The propellant (B) is 5 to 20% by mass, preferably 5 to 15% by mass, based on the total composition. If it is less than 5% by mass, there is a problem in ejecting in a foam state, and if it exceeds 20% by mass, the resin content in the primer ejected in a foam state is lowered, which is not desirable for ensuring stable adhesion.

  Examples of the additive in the present invention include an adhesion improver, a storage stability improver (dehydrating agent), a weather resistance stabilizer, a curing catalyst, and a dye. These additives can be arbitrarily added in combination as appropriate according to the purpose and use of the primer.

  Adhesion improver is used to improve the adhesion of the primer after curing. Coupling agent, epoxy resin, phenol resin, acrylic resin, alkyl titanates, organic isocyanate, active hydrogen group-containing coupling And a reaction product of an agent and an organic isocyanate compound.

  Examples of the coupling agent include various coupling agents such as silane-based, aluminum-based, and zircoaluminum-based and / or partial hydrolysis-condensation products thereof. Of these, silane coupling agents are particularly preferable.

  Specific examples of the silane coupling agent include active hydrogen group-containing silane coupling agents such as aminosilane coupling agents and mercaptosilane coupling agents, and other silane coupling agents. Examples of aminosilane coupling agents include N-phenyl-3-aminopropyltrimethoxysilane, aminomethyltriethoxysilane, N- (2-aminoethyl) aminomethyltrimethoxysilane, aminomethyldiethoxysilane, N- (2-aminoethyl) methyltributoxy Silane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminoisobutyltrimethoxysilane, N-bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, N- (2- Aminoethyl) -3-amino Trimethoxysilane, N- (2- aminoethyl) -3-aminopropyl methyl dimethoxysilane, N- (2- aminoethyl) -3-like amino-2-methylpropyl trimethoxysilane. Examples of the mercaptosilane coupling agent include 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylethyldimethoxysilane, 3 -Mercaptopropylethyldiethoxysilane, 3-mercaptopropyldimethylmethoxysilane, 2-mercaptoethylmethyldimethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane and the like. Other silane coupling agents include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, 3,4-epoxycyclohexylethylmethyldimethoxy. Vinyl groups such as epoxy silane coupling agents such as silane, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxylane, vinylmethyldimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, etc. Silane coupling agent containing (meth) acryloyl group, and methyl silicate, methyltrimethoxysilane, ethyltrimethoxysilane, butyltrimethoxysilane, octyltrimethoxysila Hydrocarbon group-containing silane coupling agents such as dodecyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, dibutyldimethoxysilane, diphenyldimethoxysilane, trimethylmethoxysilane, triethylmethoxysilane, triphenylmethoxysilane, etc. Is mentioned.

  As a partial hydrolysis-condensation product of a silane coupling agent, the partial hydrolysis-condensation product of the silane coupling agent mentioned above and the number average molecular weight are 250-2500. Such a partial hydrolysis-condensation product is produced at room temperature to 100 ° C by mixing a silane coupling agent alone or in combination, adding a necessary amount of water, and adding a small amount of a condensation catalyst such as hydrochloric acid or sulfuric acid as necessary. It can be easily obtained by proceeding with condensation while removing methanol.

  Examples of the compound having a methoxysilyl group as a partial hydrolysis condensate of methyl silicate include Methyl silicate 47, Methyl silicate 51, Methyl silicate 55, Methyl silicate 58 and Methyl silicate 60 manufactured by Nippon Colcoat Co., Ltd. As a compound containing a methoxysilyl group as a partial hydrolysis condensate such as dimethyldimethoxysilane, AFP-1, AFP-6, KR213, KR217, KR9218 manufactured by Shin-Etsu Chemical; TRS165, TR3357 manufactured by Toshiba Silicone; Japan Examples include Y-1587, FZ-3701, FZ-370 and the like manufactured by Unicar. Further, as a partial hydrolysis condensate of N- (2-aminoethyl) -3-propyltrialkoxysilane and dimethyldialkoxysilane, C1-031-07 manufactured by Nippon Unicar Co., Ltd. and 3-aminopropyltrialkoxysilane Examples of the partially hydrolyzed condensate include C1-031-09 manufactured by Nippon Unicar Company.

  Specifically, the reaction product of the active hydrogen group-containing coupling agent and the organic isocyanate compound includes an isocyanate group of the organic isocyanate similar to the organic isocyanate for the synthesis of the isocyanate group-containing urethane prepolymer and the silane cup. Active hydrogen group-containing silane coupling agents such as aminosilane coupling agents and mercaptoaminosilane coupling agents mentioned as the ring agent are reacted with active hydrogen groups of the same silane coupling agent, and hydrolyzed in the molecule. It is a reaction product having at least one silyl group and not having an isocyanate group or having at least one isocyanate group. The reaction equivalent ratio of isocyanate groups to active hydrogen groups (isocyanate groups / active hydrogen groups) is preferably 0.1 or more / 1, more preferably 0.5-10 / 1. If it is less than 0.1 / 1, the water-resistant adhesiveness is inferior, and if it exceeds 10/1, the content of hydrolyzable silyl groups in the reaction product is reduced, especially when the base is an inorganic material. descend. In the reaction, a known organic solvent such as toluene or ethyl acetate, a known urethanization catalyst similar to the curing catalyst described later, or the like can be used.

  The adhesion improver is preferably blended in an amount of 0 to 30 parts by mass, particularly 0.1 to 10 parts by mass with respect to 100 parts by mass of the resin (A1).

The storage stability improver (dehydrating agent) is used as needed for the purpose of improving storage stability by reacting or adsorbing moisture in the primer and dehydrating, and specifically, for example, Examples thereof include vinyltrimethoxysilane, p-toluenesulfonyl isocyanate, orthoformate and the like.
The storage stability improver (dehydrating agent) is preferably blended in an amount of 0 to 20 parts by mass, particularly 0.1 to 10 parts by mass with respect to 100 parts by mass of the resin (A1).

  The weather resistance stabilizer is used to prevent oxidation, photodegradation and thermal degradation after curing of the resin (A1), and to improve not only the weather resistance but also the heat resistance. Specific examples include hindered phenol-based antioxidants, hindered amine-based antioxidants, ultraviolet absorbers, and photocurable compounds.

  Examples of the hindered phenol antioxidant include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-). tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexane-1,6-diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenylpropionamide)], benzenepropanoic acid Examples include 3,5-bis (1,1-dimethylethyl) -4-hydroxy C7-C9 side chain alkyl ester, 2,4-dimethyl-6- (1-methylpentadecyl) phenol, and the like.

  Examples of the hindered amine antioxidant include bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl. ] Butyl malonate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, methyl-1,2,2,6,6-pentamethyl-4-piperidyl sebacate, 4-benzoyloxy- Examples include 2,2,6,6-tetramethylpiperidine. In addition to Sanyo LS-292, trade names manufactured by Sankyo Co., Ltd., trade names Adeka Stub series LA-52, LA-57, LA-62, LA-67, LA-77, LA- 82, LA-87 and other low molecular weight hindered amine antioxidants with a molecular weight of less than 1,000, also LA-63P, LA-68LD or Ciba Specialty Chemicals' product names CHIMASSORB series 119FL, 2020FDL, 944FD, 944LD And high molecular weight hindered amine antioxidants having a molecular weight of 1,000 or more.

  Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers such as 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, and 2- (4,6-diphenyl- Triazine-based UV absorbers such as 1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol, benzophenone-based UV absorbers such as octabenzone, 2,4-di-tert-butylphenyl Examples include benzoate-based ultraviolet absorbers such as -3,5-di-tert-butyl-4-hydroxybenzoate.

  Examples of the photocurable compound include a compound containing one or more groups that are reactively cured by light such as an acryloyl group or a methacryloyl group in the molecule. Specifically, for example, a hydroxyl group-containing acrylate compound is added to an isocyanate group-containing urethane resin. Polyester acrylate or polyester methacrylate such as urethane acrylate, urethane methacrylate, ester acrylate or ester methacrylate such as trimethylolpropane triacrylate or trimethylolpropane trimethacrylate, acrylate or methacrylate of polyethylene adipate polyol, etc. Polyether acrylate such as ether polyol acrylate or methacrylate, polyether methacrylate, or poly Examples thereof include vinyl cinnamates and azido resins, and monomers and oligomers having a molecular weight of 10,000 or less, and more preferably a molecular weight of 5,000 or less are preferred. Particularly, acryloyl groups and / or methacryloyl groups are averaged per molecule. The thing containing 2 or more is preferable.

  The weathering stabilizer is preferably blended in an amount of 0 to 30 parts by mass, particularly 0.1 to 20 parts by mass with respect to 100 parts by mass of the resin (A1).

Curing catalyst, a curing catalyst for promoting the curing of the iso cyanate group-containing urethane prepolymer and a crosslinkable silyl group-containing resin can be mentioned up.
Specific examples of the curing catalyst for accelerating the curing of the isocyanate group-containing urethane-based prepolymer and the crosslinkable silyl group-containing resin include organometallic compounds and amines, such as tin octylate and naphthenic acid. Divalent organotin compounds such as tin, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dimaleate, dibutyltin distearate, dioctyltin dilaurate, dioctyltin diversate, dibutyltin oxide, dibutyltin bis (triethoxysilicate) ), Tetravalent organic tin compounds such as a reaction product of dibutyltin oxide and phthalate ester, dibutyltin bis (acetylacetonate), tin chelate compound EXCESTAR C-501 manufactured by Asahi Glass Co., zirconium tetrakis (acetylacetate) Natto), titanium tetrakis (acetylacetonate), aluminum tris (acetylacetonate), aluminum tris (ethylacetoacetate), acetylacetone cobalt, acetylacetone iron, acetylacetone copper, acetylacetone magnesium, acetylacetone bismuth, acetylacetone nickel, acetylacetone zinc, acetylacetone manganese Chelate compounds of various metals such as manganese, such as lead octylate and zirconium octylate, metal organic acid salts of metals such as iron, cobalt, copper, zinc, zirconium and lead and organic acids such as octylic acid and naphthenic acid, Titanates such as tetra-n-butyl titanate and tetrapropyl titanate, organic bismuth compounds such as bismuth octylate and bismuth versatate, , Primary amines such as octylamine, secondary amines such as dibutylamine and dioctylamine, alkanolamines such as monoethanolamine, diethanolamine and triethanolamine, primary amines such as diethylenetriamine and triethylenetetramine , Secondary amines, triethylamine, tributylamine, triethylenediamine, tertiary amines such as N-ethylmorpholine, or salts of these amines with carboxylic acids, inorganic acid compounds such as kaolin clay and hydrochloric acid Organic phosphoric acid compounds such as ethyl acid phosphate and 2-ethylhexyl acid phosphate, or salts of these with amines. Of these, organotin compounds and metal chelate compounds are preferred, tin-based chelate compounds are preferred, and dibutyltin bis (acetylacetonate) is the most preferred because of its high reaction rate and low toxicity and low volatility. better not.
It is preferable that the curing catalyst is blended in an amount of 0 to 10 parts by mass, particularly 0.01 to 2 parts by mass with respect to 100 parts by mass of the resin (A1) from the viewpoints of curing speed and physical properties of the cured product.

  As the dye, conventionally known dyes such as water-soluble (anionic and cationic), water-insoluble (including dispersed type), and insoluble can be used according to the resin (A1) and the solvent (A2). .

  In the present invention, each additive component can be used alone or in combination of two or more.

Although the manufacturing method of the primer in this invention is not specifically limited, For example, it can manufacture using a stainless steel or iron reaction apparatus, stirring, and a mixing apparatus. A method in which the above components are charged, mixed, dissolved, and dispersed in a state where nitrogen gas is passed through these devices and moisture is blocked, or a reaction product of the organic polyisocyanate and the active hydrogen group-containing compound. When using isocyanate group-containing urethane-based prepolymers, silane coupling agents, and partial hydrolysis condensates of silane coupling agents, etc., the product obtained by reaction in advance is mixed and dispersed with other components. (In this case, other components may be present during the reaction, or may be added and mixed after the reaction). The isocyanate group-containing urethane prepolymer, which is a reaction product of the organic isocyanate and the active hydrogen group-containing compound, can be produced by a conventionally known method.
Further, the primer composition (A) thus obtained can be filled into the aerosol container together with the propellant (B) to obtain a primer composition that can be ejected in the form of foam of the present invention. Rather than a double structure type in which the contents and propellant are filled separately, an aerosol container with a normal structure is suitable. In addition, the container nozzle may be either an upright type that is used in an upright state or an inverted type that is used upside down, and there is a degree of freedom in selecting the nozzle diameter, and the nozzle diameter and shape can be changed as required. It is desirable to change it.
The primer composition that can be ejected in the form of foam of the present invention can be used as a primer for various applications, but is preferably used mainly for surface treatment when constructing sealing materials for buildings and civil engineering. In particular, it is suitable as a primer for the surface treatment of a sealing material for construction.

As a method for applying the primer of the present invention, specifically, for example, under pressure of various joints such as a building or a civil engineering building (working part of an adherend) prior to filling with a sealing material. A primer is applied by jetting out from a sealed container through a nozzle in the form of foam, and left to dry for a predetermined time (usually 10 minutes to 1 hour). Next, the foamed primer is visually confirmed that the foam state has disappeared and the base is uniformly wet, and then a pre-prepared sealing material is filled and applied to remove the excess sealing material. Scrape with a spatula, and then finish the leveling surface flat.
Although not particularly limited to the waterproofing material and sealing material used, for example, various sealing materials such as silicone-based, modified silicone-based, polyurethane-based, acrylic urethane-based, polysulfide-based, modified polysulfide-based, butyl rubber-based, acrylic-based, etc. Of these, polyurethane-based sealing materials and modified silicone-based materials are preferred from the viewpoints of good rubber elastic properties after curing and cost advantages. In addition, waterproofing materials and sealing materials used include two-component types in which a main agent and a curing agent are mixed at the time of construction, and one-component types that are reactively cured with moisture (humidity) in the air. Although there is a problem, a one-component moisture-curing waterproofing material and a sealing material are preferable in that there is no problem due to mixing trouble or mixing failure and the construction work is easy.
Various base materials to which the construction method of the present invention can be applied include, for example, wood-based materials such as wood and plywood, various metal-based materials such as iron, stainless steel, aluminum, and titanium, acrylic resins, and phenol resins. Various types of synthetic resin materials such as epoxy resin, polyester resin, FRP, inorganic materials such as glass, tile, mortar, concrete, slate, ALC, siding, rock-based materials such as marble and granite, or paint on these surfaces And the like colored with the above. Of these, the effects of the construction method of the present invention are good, wood based materials such as wood, plywood, various synthetic resin based materials such as acrylic resin, phenol resin, epoxy resin, polyester resin, FRP, tile, mortar, There are joint materials for sealing materials for civil engineering, construction and civil engineering, where inorganic materials such as concrete, slate, ALC, siding, etc., rock materials such as marble and granite, or those whose surfaces are often colored with paint, etc. Is preferred.

Hereinafter, the present invention will be described in more detail with reference to examples and the like.
[Synthesis of isocyanate group-containing urethane prepolymer]
Synthesis example 1
A reactor equipped with a stirrer, a thermometer, a cooling tube and a dry nitrogen introduction tube was charged with 572.8 g of ethyl acetate and 112.8 g of polyoxypropylene triol having a molecular weight of 300, and 237.8 g of isophorone diisocyanate with stirring. Further, after adding 0.3 g of dibutyltin dilaurate, gradually heating to 70 ° C. while paying attention to heat generation, the urethanization reaction is carried out until the isocyanate group content becomes 4.6% by mass, and the viscosity is about 8 mPa · s. An isocyanate group-containing urethane prepolymer solution (P-1) having a nonvolatile content of 38% by mass was obtained.

Synthesis example 2
A reactor equipped with a stirrer, a thermometer, a cooling tube and a dry nitrogen introduction tube was charged with 513.2 g of ethyl acetate and 112.8 g of polyoxypropylene triol having a molecular weight of 300, and 201.5 g of xylylene diisocyanate with stirring. . Further, after adding 0.3 g of dibutyltin dilaurate, gradually heating to 70 ° C. while paying attention to heat generation, the urethanization reaction is carried out until the isocyanate group content becomes 5.1% by mass, and the viscosity is about 11 mPa · s, An isocyanate group-containing urethane prepolymer solution (P-2) having a nonvolatile content of 38% by mass was obtained.

Example 1
To 100.0 g of the isocyanate group-containing urethane prepolymer solution P-1 obtained in Synthesis Example 1, 1.8 g of KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd., 3-glycidoxypropyltrimethoxysilane), Surflon S-381 (AGC Seimi Chemical Co., Ltd., perfluoroalkyl compound fluorine-based nonionic surfactant) 3.2 g was added and mixed, then pressurized and sealed in an aerosol can with 18.0 g of dimethyl ether, and then sprayed into a foam. A possible primer composition was prepared and used for testing.

Example 2
To 100.0 g of the isocyanate group-containing urethane-based prepolymer solution P-2 obtained in Synthesis Example 2, 2.0 g of KBM-573 (manufactured by Shin-Etsu Chemical Co., Ltd., N-phenyl-3-aminopropyltrimethoxysilane), Surflon S -381 (AGC Seimi Chemical Co., Ltd., perfluoroalkyl compound fluorine-based nonionic surfactant) was added and mixed, then pressurized and sealed in an aerosol can with 18.0 g of dimethyl ether, and ejected in the form of foam A primer composition that can be applied was prepared and used for testing.

Example 3
In Example 1, a primer composition that can be ejected in the same manner except that 6.3 g of Surflon S-381 (manufactured by AGC Seimi Chemical Co., perfluoroalkyl compound fluorine-based nonionic surfactant) was used was prepared. And subjected to the test.

Example 4
In Example 1, foam was similarly produced except that 6.3 g of Surflon S-386 (manufactured by AGC Seimi Chemical Co., Ltd., perfluoroalkyl compound fluorine-based nonionic surfactant) was used instead of 3.2 g of Surflon S-381 A primer composition that can be ejected in a shape was prepared and subjected to a test.

Example 5
In Example 1, foam was similarly produced except that 6.3 g of Surflon S-393 (manufactured by AGC Seimi Chemical Co., Ltd., a perfluoroalkyl compound fluorine-based nonionic surfactant) was used instead of 3.2 g of Surflon S-381. A primer composition that can be ejected in a shape was prepared and subjected to a test.

Example 6
In Example 1, a primer composition that can be ejected in the same manner except that 3.2 g of Surflon S-386 was further added was prepared and used for the test.

Example 7
In Example 1, a primer composition that can be ejected in the same manner except that 3.2 g of Surflon S-393 was further added was prepared and used for the test.

Example 8
In Example 1, a primer composition that can be ejected in the same manner as in Example 1 except that 3.2 g of Novec 4430 (manufactured by Sumitomo 3M Limited, fluorine-based surfactant) was added was prepared and used for the test.

Example 9
In Example 1, a primer composition that can be ejected in the same manner except that 3.2 g of Sunfin DM-200 (manufactured by Sanyo Chemical Industries, polyethylene glycol dimethyl ether nonionic surfactant) was added, was prepared. It used for the test.

Example 10
In Example 1, a primer composition was prepared in the same manner as above except that 3.2 g of SY Glyster OE750 (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., erucic acid ester nonionic surfactant) was added. It was used for.

Example 11
In Example 1, a primer composition that can be ejected in the same manner except that 3.2 g of S-Face IS-204P (manufactured by Sakamoto Pharmaceutical Co., Ltd., polyglycerin fatty acid ester nonionic surfactant) was added. Prepared and subjected to testing.

Example 12
In Example 1, a primer composition that can be ejected in the same manner except that 3.2 g of Polyflow KL245 (manufactured by Kyoeisha Chemical Co., Ltd., base material wetting material) was added was prepared and used for the test.

Comparative Example 1
A primer composition was prepared by adding 1.8 g of KBM-403 to 100.0 g of the isocyanate group-containing urethane-based prepolymer solution P-1 obtained in Synthesis Example 1, and subjected to a test.

Comparative Example 2
In Example 1, a primer composition was prepared in the same manner except that the surfactant was not used, and was subjected to the test.

Comparative Example 3
A primer composition was prepared in the same manner as in Example 1 except that dimethyl ether was not used and 3.2 g of SY Glyster OE750 was used instead of 3.2 g of Surflon S-381.

Comparative Example 4
A primer composition was prepared in the same manner as in Example 1 except that dimethyl ether was not used and 3.2 g of S-Face IS-204P was used instead of 3.2 g of Surflon S-381, and it was subjected to the test.

Comparative Example 5
A primer composition was prepared in the same manner as in Example 1 except that dimethyl ether was not used and 3.2 g of Polyflow KL245 was used instead of 3.2 g of Surflon S-381.

Test method (Coating unevenness)
A ceramic siding board is pasted on the plywood, and two joints with a width of 10 mm x depth of 18 mm x length of 1000 mm are formed side by side, and each joint is filled with a square backer of width 10 mm x thickness 10 mm x length 1000 mm. The joint depth was adjusted to 8 mm. The prepared two joints were used as vertical joints, and the primer composition was spray-coated on the vertical joints having a total length of 2000 mm from top to bottom (foam-like) once and within a predetermined time (5 seconds). When the ceramic siding board edge of the joint was visually observed, it was evaluated whether the coated surface was uniformly coated without any unpainted or unevenness.
Yes, when there is no unpainted or uneven coating on the small edge surface, x when there is a lot of unpainted or uneven coating on the coated surface, and a small amount of unpainted or uneven coating can be confirmed on the coated surface The case was rated as Δ.
[Foamability]
(Foam-like) The foamability when the primer composition was spray-coated was visually observed and evaluated.
The case where the primer composition containing fine bubbles was formed on the small area of the ceramic siding board small circle was marked with ◯, the case where bubbles were not formed was marked with ×, and the case where bubbles were formed but partly marked with Δ.
[Simultaneous application on both sides]
A ceramic siding board is pasted on the plywood, and two joints with a width of 10 mm x depth of 18 mm x length of 1000 mm are formed side by side, and each joint is filled with a square backer of width 10 mm x thickness 10 mm x length 1000 mm. The joint depth was adjusted to 8 mm. The prepared two joints were used as vertical joints, and the primer composition was spray-coated on the vertical joints having a total length of 2000 mm from top to bottom (foam-like) once and within a predetermined time (5 seconds). At this time, the left and right ceramics-type siding board edge surfaces in the joint were visually observed, and it was evaluated whether or not there was no unpainted or uneven coating on both edge surfaces.
○, when there is no unpainted or uneven coating on both facets, and when there is a lot of unpainted or unevenness on both facets and it is not evenly applied and it is necessary to apply again. A case where the unpainted residue or unevenness was slightly confirmed and the coating work was not performed uniformly and the coating operation was required again was marked with Δ.
〔Adhesiveness〕
The adhesion was evaluated by a peel test. After spraying (foam-like) primer composition on a flexible board of 50 mm x 50 mm x 8 mm and curing at room temperature for 15-30 minutes, an auton siding sealant (manufactured by Auto Chemical Industries) is about 15 mm wide and about 10 mm high The test specimens were cured and cured for 3 days at 50 ° C. and 80% relative humidity. After curing and curing, the end of the bead-like cured product is picked, a cut is made between the end of the cured product and the primer coating film with a cutter knife or the like, and the bead-like cured product is folded 180 ° in the length direction and pulled (180 ° ) And visually evaluated the state of destruction.
○ when the rate of cohesive failure of the sealing material in the sealing material adhesion area is 50% or more, △ when the rate of cohesive failure of the sealing material in the sealing material adhesion area is 30% or more and less than 50%, primer peeling ( The case where the primer coating film peels from the adherend) and the sealing material easily peels from the primer coating film (the rate of cohesive failure of the sealing material in the sealing material adhesion area is less than 30%) was evaluated as x.
[Pollution prevention]
A ceramic siding board is pasted on the plywood, and two joints with a width of 10 mm x depth of 18 mm x length of 1000 mm are formed side by side, and each joint is filled with a square backer of width 10 mm x thickness 10 mm x length 1000 mm. The joint depth was adjusted to 8 mm. The prepared two joints were used as vertical joints, and the primer composition was spray-coated on the vertical joints having a total length of 2000 mm from top to bottom (foam-like) once and within a predetermined time (5 seconds). At that time, the surface of the ceramic siding board and the basement of the left and right sides of the joint were visually observed to evaluate whether the surface of the ceramic siding board and the sagging of the basement were observed.
The case where there was no splashing on the surface of the ceramic siding board and the sagging of the basement part was evaluated as “◯”, the case where much scattering and sagging could be confirmed was evaluated as “X”, and the case where the scattering and sagging could be confirmed slightly was evaluated as “Δ”.
Tables 1 to 3 collectively show these results and the composition of the (foam-like) primer composition.

Claims (5)

A primer composition containing a resin (A1), a solvent (A2), a surfactant (A3), and a propellant (B), which can be ejected in the form of a foam,
The resin (A1) is an isocyanate group-containing urethane prepolymer or a crosslinkable silyl group-containing resin, the solvent (A2) is an organic solvent, and the surfactant (A3) is a fluorine-based nonionic surfactant. A primer composition that can be ejected in the form of a foam. The primer composition which can be ejected in the foam form of Claim 1 whose said solvent (A2) is an organic solvent which does not have reactivity with an isocyanate group containing urethane type prepolymer or crosslinkable silyl group containing resin. The propellant (B) is a propellant containing at least one selected from the group consisting of dimethyl ether, carbon dioxide, nitrogen, nitrous oxide, petroleum gas (LPG), propane, isobutane, and n-butane. The primer composition which can be ejected to the foam form of Claim 1 or 2. The primer composition which can be ejected in the foam form as described in any one of Claims 1-3 which further contains an additive. A primer composition capable of being jetted out in a foam form according to any one of claims 1 to 4, sprayed in a foam form on a construction part of an adherend, coated, and cured. Construction method.