JP7412705B2 - Surface protection sheets for structures and structures with surface protection sheets - Google Patents

Description

The present invention relates to a structural surface protection sheet used for structures such as concrete. The present invention also relates to a structure with a surface protection sheet, which includes the surface protection sheet for structures described above.

BACKGROUND ART In structures such as bridges and tunnels, cracks, junks, etc. may occur if construction defects occur during construction, or if a long period of time has passed after construction. In structures where cracks, junkers, etc. occur, the strength of the structure decreases. Many of these structures support social infrastructure such as traffic and transportation, and therefore cannot be easily rebuilt or demolished. Furthermore, it is difficult to perform large-scale repairs or reinforcement by stopping infrastructure functions.

Also, concrete is usually alkaline. However, concrete gradually becomes neutral from the surface toward the inside due to the effects of carbon dioxide and acid rain in the air. When the inside of a concrete structure becomes neutral, the reinforcing bars corrode and the strength of the concrete structure decreases significantly. In particular, if there are cracks or junks, the material tends to change to neutrality from there toward the inside, and the strength of the concrete structure tends to decrease.

Therefore, a method is known in which the concrete surface is protected with a protective sheet or the like to prevent the concrete surface portion from peeling off or to suppress a decrease in the strength of the concrete structure.

Patent Document 1 listed below includes a concrete structure and a protective sheet covering the surface of the concrete structure, and the protective sheet has a protective structure for the concrete structure including a base material made of resin and a carbon film. Disclosed.

Further, Patent Document 2 below discloses a protective structure for a hardened cement structure, which includes a hardened cement structure and a protective sheet that covers the surface of the hardened cement structure via an adhesive layer. There is. In this protective structure for a cement cured structure, the protective sheet is a laminate including a resin layer and a carbon film laminated on the resin layer, and the adhesive layer is a cured modified silicone resin and an epoxy resin. This is a cured resin layer containing a cured product.

Japanese Patent Application Publication No. 2014-009508 JP2017-008626A

When a protective sheet as described in Patent Documents 1 and 2 is placed on the surface of the structure, a decrease in the strength of the structure can be suppressed. However, in conventional protective sheets such as those described in Patent Documents 1 and 2, the protective sheet is damaged due to hydrolysis of the resin component contained in the protective sheet due to ultraviolet rays and moisture such as water vapor in the air and rainwater. Gradually deteriorates. Therefore, with conventional protective sheets, if a long period of time has passed since the protective sheet was placed on the surface of a structure (for example, after 20 to 50 years), the protective sheet does not function sufficiently, and as a result, the structure strength decreases.

In addition, with the protective sheets as described in Patent Documents 1 and 2, it is difficult to suppress a decrease in the strength of the concrete structure due to cracks generated inside the concrete structure and the accompanying water intrusion into the inside.

An object of the present invention is to provide a surface protection sheet for structures that can considerably suppress a decrease in the strength of the structure. Moreover, the objective of this invention is to provide the structure with a surface protection sheet provided with the said surface protection sheet for structures.

According to a broad aspect of the present invention, there is provided a surface protection sheet for protecting the surface of a structure, comprising a base material and a resin layer containing a compound capable of releasing carbonate ions or calcium ions. A surface protection sheet is provided.

In a particular aspect of the surface protection sheet for structures according to the present invention, the resin layer is disposed on the first surface side of the base material, and the resin layer is an adhesive resin layer, The material of the resin layer contains a curable component.

In a particular aspect of the surface protection sheet for structures according to the present invention, the curable component includes a modified silicone compound and an epoxy compound.

In a particular aspect of the surface protection sheet for structures according to the present invention, the curable component includes a modified silicone compound, an epoxy compound, a silanol condensation catalyst, and an epoxy curing agent.

In a particular aspect of the surface protection sheet for structures according to the present invention, in the material of the resin layer, the content of the epoxy compound is 1 part by weight or more and 100 parts by weight based on 100 parts by weight of the modified silicone compound. It is as follows.

In a particular aspect of the surface protection sheet for structures according to the present invention, the compound capable of releasing carbonate ions or calcium ions is tricalcium silicate, dicalcium silicate, calcium aluminate, calcium aluminoferrite, hydroxide Calcium, calcium oxide, calcium sulfate, calcium carbonate, calcium bicarbonate, sodium carbonate, or sodium bicarbonate.

In a particular aspect of the surface protection sheet for structures according to the present invention, the content of the compound capable of releasing carbonate ions or calcium ions is 5% by weight or more in 100% by weight of the resin layer.

In a particular aspect of the surface protection sheet for structures according to the present invention, the base material includes polyethylene terephthalate, polypropylene, or polyethylene.

In a particular aspect of the surface protection sheet for structures according to the present invention, the surface protection sheet for structures includes a carbon film on the surface of the base material.

According to a broad aspect of the present invention, a structure with a surface protection sheet includes a structure and the above-mentioned structure surface protection sheet, and the structure surface protection sheet is disposed on the surface of the structure. things are provided.

The surface protection sheet for structures according to the present invention is a surface protection sheet for protecting the surface of a structure, and includes a base material and a resin layer containing a compound capable of releasing carbonate ions or calcium ions. Since the surface protection sheet for structures according to the present invention has the above-mentioned configuration, it is possible to considerably suppress a decrease in the strength of the structure.

FIG. 1 is a cross-sectional view schematically showing a structure with a surface protection sheet according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a structure with a surface protection sheet according to a second embodiment of the present invention.

The details of the present invention will be explained below.

(Surface protection sheet for structures)
The surface protection sheet for structures (hereinafter sometimes abbreviated as "protective sheet") according to the present invention is used to protect the surface of structures. The protective sheet according to the present invention includes a base material and a resin layer containing a compound capable of releasing carbonate ions or calcium ions (hereinafter sometimes referred to as "compound X"). The resin layer contains compound X.

Since the protective sheet according to the present invention has the above-mentioned configuration, it is possible to considerably suppress a decrease in the strength of the structure.

The mechanism by which the reduction in strength of a structure can be suppressed by using the protective sheet according to the present invention will be described below.

The protective sheet according to the present invention is placed on the surface of the structure from the resin layer side. When the resin layer or the surface of the structure comes into contact with rainwater, water vapor in the air, moisture attached to concrete, etc., the moisture infiltrates into the structure through cracks and the like. Furthermore, when the compound X contained in the resin layer comes into contact with these moistures, it flows out or diffuses into the structure. At this time, the carbonate ions or calcium ions contained in these moisture and the carbonate ions or calcium ions released from the above compound X chemically react on the surface and inside of the structure, and calcium carbonate (cement) is generated. . That is, a calcium carbonate layer is generated at the interface between the surface of the structure and the resin layer, and inside the structure (for example, in cracks that are paths for moisture infiltration). The structure of the structure is further protected by the generated calcium carbonate. Moreover, even if the protective film is degraded by ultraviolet rays or the like, the surface of the structure is strongly protected by the generated calcium carbonate. Therefore, by using the protective sheet according to the present invention, it is possible to considerably suppress a decrease in the strength of the structure. Note that calcium carbonate is generally thought to be produced over several months to several years.

Examples of the structures include concrete structures, RC elevated structures, mountain tunnels, underground tunnels, and the like. Since the effects of the present invention can be exhibited even more effectively, it is preferable that the structure is a concrete structure. The surface protection sheet for structures is preferably a surface protection sheet for concrete structures.

Further, the above-mentioned structure may be a newly constructed structure or a structure having defective parts such as cracked parts and junker parts.

The details of each component used in the protective sheet according to the present invention will be explained below.

(Base material)
The protective sheet includes a base material.

The above-mentioned base material is not particularly limited. Examples of the base material include metal, plastic, paper, and cloth. Examples of the plastics include polyethylene terephthalate (PET), polyethylene naphthalate, polycarbonate, polyamide, acrylic resin, phenol resin, melamine resin, epoxy resin, urea resin, vinyl chloride resin, polyethylene, and polypropylene.

Preferably, the base material includes polyethylene terephthalate, polypropylene, or polyethylene. In this case, the strength of the base material can be increased, deterioration of the base material can be effectively suppressed, and the handleability of the protective sheet can be improved.

The base material may contain an antioxidant. The base material preferably contains the antioxidant. A conventionally known antioxidant can be used as the antioxidant. By using an antioxidant, deterioration of the base material can be effectively suppressed.

The thickness of the base material is preferably 1 μm or more, more preferably 10 μm or more, and preferably 1000 μm or less, more preferably 500 μm or less. When the thickness of the base material is not less than the lower limit and not more than the upper limit, it is possible to effectively prevent the inside of the concrete structure from becoming neutral, and the effects of the present invention can be exhibited even more effectively. can do. Moreover, when the thickness of the base material is at least the above lower limit and below the above upper limit, cracks or cracks in the base material can be effectively suppressed, and the handleability and workability of the protective sheet can be improved. .

The coefficient of linear expansion of the base material is preferably 10×10 ⁻⁵ /K or less, more preferably 5×10 ⁻⁵ /K or less. When the coefficient of linear expansion of the base material is below the upper limit, cracks or cracks in the base material can be effectively suppressed, and when the protective sheet includes a carbon film, cracks or cracks in the carbon film can be effectively suppressed. can be effectively suppressed.

The coefficient of linear expansion of the base material is measured in accordance with JIS K7197.

(resin layer)
The protective sheet includes a resin layer containing compound X. The resin layer is preferably placed on the first surface side of the base material. In addition, the said resin layer may be arrange|positioned directly on the 1st surface of the said base material, and may be arrange|positioned through other layers, such as a carbon film.

The resin layer may be a resin layer that does not have adhesive properties, or may be a resin layer that has adhesive properties. Examples of methods for adhering the protective sheet to the surface of the structure include a method using an adhesive, a method using an adhesive, a method using anchoring, and a method using screws. Two or more of these methods may be used. An adhesive may or may not be interposed between the protective sheet and the surface of the structure.

From the viewpoint of improving the workability of the protective sheet on the surface of the structure, the resin layer is preferably a resin layer having adhesive properties. That is, the resin layer is preferably an adhesive layer.

The resin layer preferably contains a thermoplastic resin, a hot melt resin, a thermosetting resin, or a moisture curable resin. The resin layer preferably contains a thermoplastic resin, a hot melt resin, a cured product of a thermosetting resin, or a cured product of a moisture-curable resin.

The resin layer contains the compound X. The material of the resin layer contains the compound X described above. The material for the resin layer preferably contains a curable component. The resin layer preferably contains a semi-cured product of the curable component, and preferably contains a cured product of the curable component.

<Curable component>
The material for the resin layer preferably contains a curable component. The above-mentioned curable component is a curable component. The above-mentioned curable component may be liquid at 23°C, paste-like at 23°C, or semi-solid at 23°C. Examples of the curable component include a curable compound, a curing agent, a photopolymerization initiator, and the like. The curable component preferably includes the curable compound and the curing agent. The curable component is preferably a mixture of the curable compound and the curing agent. Each of the curable compound, curing agent, and photopolymerization initiator may be used alone or in combination of two or more.

The curable component may be a resin that is solid at 23° C. obtained by heating and drying a resin-containing solution in which a resin and a solvent are mixed and removing the solvent, or a resin that is solid at 23° C. by polymerizing a monomer solution or an oligomer solution. The resulting polymer may be solid at 23°C, or it may be a polymer that is solid at 23°C obtained by reacting two or more types of monomers or two or more types of oligomers.

Examples of the curable compound include silicone compounds, epoxy compounds, polyol compounds, phenol compounds, vinyl ester compounds, and naphthoxazine compounds.

Examples of the silicone compound include organopolysiloxanes having two or more alkenyl groups bonded to silicon atoms. The main chain of the organopolysiloxane is generally a diorganosiloxane polymer, but may have a partially branched structure or a cyclic structure. Examples of the alkenyl group that the organopolysiloxane has include a vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, butenyl group, 1-methyl-2-propenyl group, petenyl group, hexenyl group, octenyl group, and a cyclohexenyl group.

The silicone compound may be a modified silicone compound. The silicone compound is preferably a modified silicone compound.

The above-mentioned modified silicone compound is not particularly limited, but includes moisture-curable modified silicone compounds and the like. The moisture-curable modified silicone compound has a hydrolyzable silicon group. The modified silicone compound having a hydrolyzable silicon group has a main chain (a portion excluding the hydrolyzable silicon group) of a polyether polymer, a polyolefin polymer, or an acrylic polymer. Therefore, examples of monomers that serve as materials for the main chain include alkylene oxide monomers, olefin monomers, and acrylic monomers. The above polymer may be a homopolymer or a copolymer. When the above polymer is a copolymer, examples of monomers used include alkylene oxide monomers, olefin monomer components, acrylic monomers, and vinyl monomers. Only one type of modified silicone compound may be used, or two or more types may be used in combination.

Examples of the alkylene oxide monomer include ethylene oxide, propylene oxide, and butylene oxide. From the viewpoint of improving elongation after curing and viscous ease of handling, the alkylene oxide monomer is preferably polypropylene oxide obtained by polymerizing propylene oxide.

Examples of the olefin monomer include isobutylene and the like.

Examples of the acrylic monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, and 2-ethylhexyl. (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isomyristyl (meth)acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 2-Butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol Di(meth)acrylate, propylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol Tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 3-hydroxy-3 -Methylbutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, pentaerythritol tri(meth)acrylate, 2-[(meth)acryloyloxy]ethyl 2-hydroxyethylphthalate, 2-[(meth) ) acryloyloxy]ethyl 2-hydroxypropylphthalate and the like. In addition, when the acrylic polymer is copolymerized with another vinyl monomer component, the hydrolyzable silicon group can be introduced by copolymerizing the vinyl monomer component having a hydrolyzable silicon group.

From the viewpoint of improving weather resistance, the main chain of the modified silicone compound preferably has a structural unit derived from an acrylic monomer.

From the viewpoint of improving weather resistance, the content of structural units derived from acrylic monomers in 100% by weight of the main chain in the modified silicone compound is preferably 5% by weight or more, and preferably 20% by weight or less.

The above-mentioned hydrolyzable silicon groups include, but are not particularly limited to, halogenated silyl groups, alkenyloxysilyl groups, acyloxysilyl groups, aminosilyl groups, aminooxysilyl groups, oximesilyl groups, amidosilyl groups, and alkoxysilyl groups. Can be mentioned.

The number of hydrolyzable groups bonded to silicon atoms in the hydrolyzable silicon group is preferably 1 or more, and preferably 3 or less. The number of hydrolyzable groups bonded to one silicon atom may be one, or two or more. The above-mentioned hydrolyzable group and non-hydrolyzable group may be bonded to one silicon atom. The hydrolyzable silicon group is preferably a monoalkoxysilyl group, a dialkoxysilyl group, or a trialkoxysilyl group because they have excellent stability and are easy to handle.

The number average molecular weight of the modified silicone compound is preferably 1,000 or more, more preferably 4,000 or more, even more preferably 10,000 or more, and preferably 500,000 or less, more preferably 100,000 or less, still more preferably 30,000 or less. When the number average molecular weight of the modified silicone compound is equal to or higher than the lower limit, it is possible to shorten the time required to harden the material of the resin layer and create the resin layer, and the durability of the resin layer can be further improved. can be improved. When the number average molecular weight of the modified silicone compound is below the above upper limit, the viscosity of the material of the resin layer can be improved, and the handleability can be improved.

The number average molecular weight of the modified silicone compound can be measured using GPC (gel permeation chromatography).

When the curable component contains the modified silicone compound, the curable component preferably contains a silanol condensation catalyst. That is, the curable component preferably includes the modified silicone compound and a silanol condensation catalyst. By using the above silanol condensation catalyst, the material of the resin layer containing the modified silicone compound can be cured in a short time, and the resin layer can be obtained satisfactorily in a short time. As for the said silanol condensation catalyst, only 1 type may be used, and 2 or more types may be used together.

Examples of the silanol condensation catalyst include tin catalysts such as monoalkyl tin esters and dialkyl tin esters, poly(dialkyl stannoxane) disilicate compounds, and organic titanates.

Examples of the monoalkyl tin ester include butyltin tris(2-ethylhexanoate). Examples of the dialkyltin ester include dibutyltin acetate, dibutyltin dilaurate, dibutyltin dioctoate, dibutyltin dioleate, dibutyltin dimethoxide, dibutyltin diphenoxide, dibutyltin diacetylacetonate, dibutyltin acetoacetate, and stannous octoate. etc.

Examples of the organic titanates include titanium alkoxides such as tetrabutyl titanate, tetraisopropyl titanate, tetramethyl titanate, tetra(2-ethylhexyltitanate) triethanolamine titanate, titanium tetraacetylacetonate, titanium ethyl acetoacetate, and octylene. Examples include titanium chelates such as glycolate.

The content of the silicone condensation catalyst is preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, preferably 10 parts by weight or less, and more preferably 5 parts by weight based on 100 parts by weight of the modified silicone compound. It is as follows. When the content of the silicone condensation catalyst is at least the above lower limit, the material of the resin layer containing the modified silicone compound can be cured in a short time, and the resin layer can be obtained satisfactorily in a short time. When the content of the silicone condensation catalyst is at most the above upper limit, the adhesive strength of the resin layer can be increased.

The above-mentioned epoxy compounds include bisphenol type epoxy compounds such as bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, and hydrogenated products thereof; glycidyl ether type epoxy compounds such as polypropylene glycol diglycidyl ether type epoxy compounds; Epoxy compounds; ester type epoxy compounds such as phthalate diglycidyl ester type epoxy compounds; novolak type epoxy compounds such as phenol novolac type epoxy compounds, bisphenol A novolac type epoxy compounds, cresol novolac type epoxy compounds, and hydrogenated products thereof; Trisphenol-type polyfunctional epoxy compounds such as triphenolmethane-type epoxy compounds; nitrogen-containing compounds such as triglycidyl isocyanurate-type epoxy compounds, tetraglycidyldiaminodiphenylmethane-type epoxy compounds, tetraglycidyl metaxylene diamine-type epoxy compounds, hydantoin-type epoxy compounds, etc. Cyclic polyfunctional epoxy epoxy compounds; fused ring epoxy compounds such as naphthalene epoxy compounds; biphenyl epoxy compounds; dicyclopentadiene epoxy compounds; ether ester epoxy compounds; 3,4-epoxycyclohexylmethyl-3',4 Examples include epoxy compounds having an alicyclic structure such as '-epoxycyclohexanecarboxylate; urethane type epoxy compounds; rubber-modified epoxy compounds having a rubber skeleton such as polybutadiene and acrylonitrile butadiene rubber (NBR), and the like.

When the curable component contains the epoxy compound, the curable component preferably contains a curing agent for the epoxy compound (epoxy curing agent). That is, the curable component preferably contains the epoxy compound and an epoxy curing agent. Moreover, it is preferable that the said curable component contains the said modified silicone compound, the said epoxy compound, the said silanol condensation catalyst, and the said epoxy curing agent. In this case, in the resulting resin layer, toughness can be increased due to the cured product of the epoxy compound, and elasticity can be increased due to the cured product of the modified silicone compound.

Examples of the curing agent for the epoxy compound (epoxy curing agent) include amine compounds, imidazole compounds, amide compounds, and cyano compounds. Examples of the above amine compounds include ethylene diamine, propylene diamine, diethylene triamine, triethylene tetramine, amine adducts thereof, metaphenylene diamine, diaminodiphenylmethane, and diaminodiphenyl sulfone. Examples of the imidazole compounds include methylimidazole, 2-ethyl-4-methylimidazole, 1-isobutyl-2-methylimidazole, 1-benzyl-2-methylimidazole, 2-ethyl-4-methylimidazole, ethylimidazole, and isopropylimidazole. , 2,4-dimethylimidazole, phenylimidazole, undecylimidazole, heptadecylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5 -Hydroxymethylimidazole and the like. Examples of the above-mentioned amide compound include polyamide and the like. Examples of the cyano compound include dicyandiamide and the like.

The epoxy compound may be a latent curing agent such as ketimine in which the active amine is blocked and is activated under predetermined conditions such as moisture. For example, ketimine exists stably in the absence of water, but in the presence of water it generally becomes a primary amine and reacts with an epoxy compound. Specifically, 2,5,8-triaza-1,8-nonadiene, 2,10-dimethyl-3,6,9-triaza-2,9-undecadiene, 2,10-diphenyl-3,6,9 -triaza-2,9-undecadiene, 3,11-dimethyl-4,7,10-triaza-3,10-tridecadiene, 3,11-diethyl-4,7,10-triaza-3,10-tridecadiene, 2 , 4,12,14-tetramethyl-5,8,11-triaza-4,11-pentadecadiene, 2,4,20,22-tetramethyl-5,12,19-triaza-4,19-tri Examples include eicosadiene, 2,4,15,17-tetramethyl-5,8,11,14-tetraaza-4,14-octadecadiene, and the like.

A cured product of the epoxy compound can be obtained by reacting the epoxy compound with the epoxy curing agent.

From the viewpoint of exhibiting the effects of the present invention even more effectively, the epoxy compound preferably contains an epoxy compound having an aromatic skeleton, and is preferably a bisphenol A-type epoxy compound or a bisphenol F-type epoxy compound. More preferred.

From the viewpoint of exhibiting the effects of the present invention even more effectively, the epoxy curing agent is preferably an amine curing agent (amine compound).

The blending ratio of the epoxy compound and the epoxy curing agent can be changed as appropriate depending on the combination of the epoxy compound and the epoxy curing agent. The blending ratio of the epoxy compound and the epoxy curing agent can be set, for example, based on the epoxy equivalent (active hydrogen equivalent). With respect to 100 parts by weight of the epoxy compound, the content of the epoxy curing agent is preferably 10 parts by weight or more, more preferably 20 parts by weight or more, and preferably 120 parts by weight or less, more preferably 100 parts by weight or less. It is.

In the material of the resin layer, the content of the epoxy compound is preferably 1 part by weight or more, more preferably 2 parts by weight or more, and even more preferably 10 parts by weight or more, based on 100 parts by weight of the modified silicone compound. , preferably 100 parts by weight or less, more preferably 80 parts by weight or less, still more preferably 50 parts by weight or less. When the content of the epoxy compound is equal to or higher than the lower limit, toughness can be further effectively improved in the resin layer. When the content of the epoxy compound is at most the above upper limit, the elasticity of the resin layer can be improved even more effectively.

The above polyol compounds include bisphenol A, bisphenol F, phenol novolac, cresol novolac, cyclohexanediol, methylcyclohexanediol, isophoronediol, dicyclohexylmethanediol, dimethyldicyclohexylmethanediol, ethylene glycol, propylene glycol, butanediol, pentanediol, hexane. Diols, polyester polyols, polyether polyols, polymers obtained by dehydration condensation of polybasic acids and polyhydric alcohols, polymers obtained by ring-opening polymerization of lactones such as ε-caprolactone or α-methyl-ε-caprolactone. Examples include merging.

Examples of the curing agent for the polyol compound include polyisocyanate compounds. Examples of the polyisocyanate compounds include aromatic polyisocyanates, alicyclic polyisocyanates, aliphatic polyisocyanates, and the like. Examples of the aromatic polyisocyanate include phenylene diisocyanate, toluene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, dimethyldiphenylthane diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, and polymethylene polyphenyl polyisocyanate. . Examples of the alicyclic polyisocyanate include cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and dimethyldicyclohexylmethane diisocyanate. Examples of the aliphatic polyisocyanate include methylene diisocyanate, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate.

A urethane resin can be obtained by subjecting the polyol compound and the polyisocyanate compound to a curing reaction.

From the viewpoint of exhibiting the effects of the present invention even more effectively, the polyol compound is preferably a polyester polyol or a polyether polyol. From the viewpoint of exhibiting the effects of the present invention even more effectively, the curing agent (polyisocyanate compound) for the polyol compound is preferably diphenylmethane diisocyanate or toluene diisocyanate.

The blending ratio of the polyol compound and the polyisocyanate compound can be changed as appropriate depending on the combination of types of the polyol compound and the polyisocyanate compound. The blending amount of the polyisocyanate compound is preferably such that the amount of hydroxyl groups in the polyol compound and the amount of isocyanate groups (NCO amount) in the polyisocyanate compound are equivalent.

Examples of the silicone compound include organopolysiloxanes having two or more alkenyl groups bonded to silicon atoms. The main chain of the organopolysiloxane is generally a diorganosiloxane polymer, but may have a partially branched structure or a cyclic structure. Examples of the alkenyl group that the organopolysiloxane has include a vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, butenyl group, 1-methyl-2-propenyl group, petenyl group, hexenyl group, octenyl group, and a cyclohexenyl group.

Examples of the curing agent (crosslinking agent) for the silicone compound include organohydrogenpolysiloxane having two or more SiH groups. The organohydrogenpolysiloxane mentioned above includes phenylmethylhydrogenpolysiloxane, 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, methyl endblocked with trimethylsiloxy groups at both ends. Hydrogenpolysiloxane, dimethylsiloxane/methylhydrogensiloxane copolymer with both ends blocked with trimethylsiloxy groups, dimethylpolysiloxane with both ends blocked with dimethylhydrogensiloxy groups, dimethylsiloxane/methylhydrogensiloxane with both ends blocked with dimethylhydrogensiloxy groups Polymers, methylhydrogensiloxane/diphenylsiloxane copolymers with trimethylsiloxy groups blocked at both ends, and methylhydrogensiloxane/diphenylsiloxane/dimethylsiloxane copolymers with trimethylsiloxy groups blocked at both ends.

Examples of the above-mentioned phenol compounds include novolak-type phenol, biphenol-type phenol, naphthalene-type phenol, dicyclopentadiene-type phenol, aralkyl-type phenol, and dicyclopentadiene-type phenol.

Examples of the curing agent for the phenol compound include hexamethylenetetramine, paraformaldehyde, and the like.

Examples of the vinyl ester compound include a reaction product of an epoxy compound and an unsaturated monobasic acid. Examples of the above-mentioned epoxy compounds include bisphenol A diglycidyl ether and its high molecular weight homologues, novolak type polyglycidyl ether and its high molecular weight homologs, and aliphatic glycidyl ethers such as 1,6-hexanediol diglycidyl ether. Can be mentioned. Examples of the unsaturated monobasic acids include acrylic acid and methacrylic acid. Examples of the reaction products of the epoxy compound and the acrylic acid and methacrylic acid include epoxy (meth)acrylate and the like.

Examples of the curing agent for the vinyl ester compound include organic peroxides and the like. Examples of the organic peroxides include ketone peroxide, perbenzoate, hydroperoxide, diacyl peroxide, peroxyketal, hydroperoxide, diallyl peroxide, peroxy ester, and peroxydicarbonate.

When the curable component contains the vinyl ester compound, the curable component may contain a radically polymerizable unsaturated monomer. Examples of the radically polymerizable unsaturated monomer include styrene monomer, α-, o-, m-, p-alkyl, nitro, cyano, amide, and ester derivatives of styrene, chlorostyrene, vinyltoluene, and divinylbenzene. Styrenic monomers, dienes such as butadiene, 2,3-dimethylbutadiene, isoprene, and chloroprene; ethyl (meth)acrylate, methyl (meth)acrylate, n-propyl (meth)acrylate, (meth)acrylic Acid-i-propyl, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, (Meth)acrylic acid esters such as tetrahydrofuryl (meth)acrylate, acetoacetoxyethyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and phenoxyethyl (meth)acrylate; (meth)acrylic acid amide and ( (meth)acrylic acid amides such as meth)acrylic acid N,N-dimethylamide; vinyl compounds such as (meth)acrylic acid anilide; unsaturated dicarboxylic acid diesters such as diethyl citraconate; monomaleimide compounds such as N-phenylmaleimide ;N-(meth)acryloyl phthalimide and the like.

The content of the curable compound in 100% by weight of the material of the resin layer is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, and preferably 90% by weight or less. , more preferably 70% by weight or less, still more preferably 60% by weight or less. When the content of the curable compound is not less than the above lower limit and not more than the above upper limit, the effects of the present invention can be exhibited even more effectively.

Note that, for example, the resin layer may be prepared by preparing a material for the resin layer containing a modified silicone compound, an epoxy compound, a silanol condensation catalyst, an epoxy curing agent, and compound X. Also, for example, a first composition containing a modified silicone compound and an epoxy curing agent and not containing or containing compound X, and a second composition containing an epoxy compound and a silanol condensation catalyst and not containing or containing compound X. The above-mentioned resin layer may be prepared by preparing a composition and mixing these to prepare a material for the resin layer. In this case, even if there are irregularities or cracks on the surface of the structure, the adhesion between the structure and the resin layer can be improved, and the weather resistance of the protective sheet can also be improved.

<Compound capable of releasing carbonate ions or calcium ions (compound X)>
The resin layer contains a compound (compound X) capable of releasing carbonate ions or calcium ions. The resin layer contains the compound X. The compound X may be a compound capable of releasing carbonate ions, a compound capable of releasing calcium ions, or a compound capable of releasing both carbonate ions and calcium ions, It may be a mixture of a compound capable of releasing carbonate ions and a compound capable of releasing calcium ions. Only one type of the above compound X may be used, or two or more types may be used in combination.

Examples of the compound X capable of releasing carbonate ions include carbonates, hydrogen carbonates, and the like. Examples of the carbonate include ammonium carbonate, potassium carbonate, sodium carbonate, barium carbonate, magnesium carbonate, lithium carbonate, copper (II) carbonate, iron (II) carbonate, and silver (I) carbonate. Examples of the above-mentioned hydrogen carbonate include ammonium hydrogen carbonate, potassium hydrogen carbonate, calcium hydrogen carbonate, and sodium hydrogen carbonate.

Examples of the compound X capable of releasing calcium ions include tricalcium silicate, dicalcium silicate, calcium aluminate, calcium aluminoferrite, calcium hydrogen carbonate, calcium hydroxide, calcium oxide, and calcium sulfate.

Calcium carbonate is an example of the compound X capable of releasing both carbonate ions and calcium ions.

The above-mentioned compound is preferred. The compound X is more preferably calcium carbonate, calcium hydrogen carbonate, sodium carbonate, or sodium hydrogen carbonate. In this case, the effects of the present invention can be exhibited even more effectively.

In the material of the resin layer, the content of the compound X is preferably 20 parts by weight or more, more preferably 50 parts by weight or more, and preferably 300 parts by weight or less, based on 100 parts by weight of the curable compound More preferably, it is 200 parts by weight or less. When the content of the compound X is not less than the lower limit and not more than the upper limit, carbonate ions or calcium ions are released even more effectively, and calcium carbonate is produced satisfactorily. Further, when the content of the compound X is not less than the above lower limit and not more than the above upper limit, the physical properties of the curable resin can be maintained favorably.

In the material of the resin layer, the content of the compound X is preferably 20 parts by weight or more, more preferably 50 parts by weight or more, and preferably 300 parts by weight or less, based on 100 parts by weight of the curable component More preferably, it is 200 parts by weight or less. When the content of the compound X is not less than the lower limit and not more than the upper limit, carbonate ions or calcium ions are released even more effectively, and calcium carbonate is produced satisfactorily. Further, when the content of the compound X is not less than the above lower limit and not more than the above upper limit, the physical properties of the curable component can be maintained favorably.

The content of the compound X is preferably 20 parts by weight or more, more preferably 50 parts by weight or more, and preferably 300 parts by weight or less, with respect to 100 parts by weight of the components of the resin layer excluding the compound Preferably it is 200 parts by weight or less. When the content of the compound X is not less than the lower limit and not more than the upper limit, carbonate ions or calcium ions are released even more effectively, and calcium carbonate is produced satisfactorily. Further, when the content of the compound X is not less than the above lower limit and not more than the above upper limit, the physical properties of the resin layer can be maintained favorably.

In 100% by weight of the resin layer, the content of the compound is 60% by weight or less. When the content of the compound X is not less than the lower limit and not more than the upper limit, carbonate ions or calcium ions are released even more effectively, and calcium carbonate is produced satisfactorily. Further, when the content of the compound X is not less than the above lower limit and not more than the above upper limit, the physical properties of the resin layer can be maintained favorably.

The compound X may be contained in a microcapsule. The resin layer may include microcapsules containing the compound X as an inclusion. The surface of the compound X may be coated. When the compound X is contained in a microcapsule or the surface of the compound X is coated, the timing and amount of carbonate ions or calcium ions released from the compound X can be controlled.

Preferably, the microcapsules are capable of releasing the compound X. It is preferable that the membrane constituting the microcapsule collapses when it comes into contact with moisture. In this case, the timing and amount of carbonate ions or calcium ions released from compound X can be better controlled.

The membrane materials constituting the microcapsules and coating agents for coating the surface of compound X include hydrolyzable proteins such as ethyl cellulose and gelatin, alginic acid, starch, polylactic acid, polybutylene succinate, and polybutylene Examples include adipate terephthalate, polyurethane, polyvinyl alcohol, polymethyl methacrylate resin, polycarbonate, polyethylene terephthalate, and polybutylene terephthalate.

<Other ingredients>
The resin layer and the material of the resin layer may contain components other than the curable component and the compound X, if necessary. Examples of the other components include a dehydrating agent, an epoxy silane coupling agent, an antioxidant, a filler, a plasticizer, an anti-sagging agent, an ultraviolet absorber, a pigment, a solvent, and a fragrance. Only one type of the above-mentioned other components may be used, or two or more types may be used in combination.

The thickness of the resin layer is not particularly limited. The thickness of the resin layer is preferably 100 μm or more, more preferably 200 μm or more, and preferably 1000 μm or less, more preferably 800 μm or less. When the thickness of the resin layer is equal to or greater than the lower limit, the elasticity of the resin layer can be improved, and the adhesion to the surface of the structure can be further effectively improved. When the thickness of the resin layer is equal to or less than the upper limit, the resin layer can be easily produced.

The stress at 10% elongation of the resin layer is preferably 0.7 N/mm ² or less, more preferably 0.5 N/mm ² or less, and even more preferably 0.3 N/mm ² . When the stress at the time of 10% elongation of the resin layer is below the above upper limit, the stress to the protective sheet is effectively absorbed when the protective sheet is placed on the surface of the structure. Furthermore, when the protective sheet includes a carbon film, cracks or cracks in the carbon film can be effectively suppressed.

The stress at 10% elongation of the resin layer is measured in accordance with JIS K6251.

The resin layer may have a sea-island structure. When the resin layer has a sea-island structure, it is preferable that the island portion contains more components derived from the epoxy compound and the epoxy curing agent than the sea portion.

In the protective sheet before being adhered to the structure, the resin layer may be a cured layer or a semi-cured layer of the material of the resin layer. In the protective sheet after being adhered to the structure, the resin layer is preferably a cured layer of the material of the resin layer.

(carbon film)
The protective sheet may or may not include a carbon film. From the viewpoint of effectively suppressing the permeability of water vapor and the viewpoint of effectively suppressing the carbonation of concrete, the protective sheet preferably includes a carbon film on the surface of the base material, and It is more preferable to provide the carbon film between the layers.

Examples of the carbon film include a diamond-like carbon (DLC) film and a graphite film. From the viewpoint of suppressing carbonation of concrete more effectively, the carbon film is preferably a diamond-like carbon (DLC) film. The DLC film is an amorphous film having a diamond structure (sp3 bonds) and a graphite structure (sp2 bonds). The DLC film may or may not contain hydrogen atoms. Note that the mixing ratio of the diamond structure and the graphite structure in the DLC film and the content rate of hydrogen atoms are not particularly limited. Examples of the DLC film containing hydrogen atoms include a ta-C:H film, an a-C:H film, and the like. Examples of the DLC film that does not contain hydrogen atoms include a ta-C film, an a-C film, and the like.

The hardness of the carbon film is not particularly limited. The hardness of the carbon film may be 1 GPa or more, or less than 1 GPa. In the present invention, since the resin layer has the above configuration, cracking of the carbon film can be effectively suppressed even if the hardness of the carbon film is 1 GPa or more.

The hardness of the carbon film can be measured by a nanoindentation method. The nanoindentation method is a method in which an indenter is pushed into the sample surface and the hardness, Young's modulus, etc. of a minute area are measured from the load and displacement amount. In the present invention, a triangular pyramid-shaped diamond indenter called a Berkovich type indenter is applied perpendicularly to the carbon film surface, and a load is gradually applied from the carbon film surface to an indentation amount of 10% of the carbon film thickness, and then the load is reduced to 0. Gradually return to . The value P/A obtained by dividing the maximum load P at this time by the projected contact area A of the indenter contact portion is calculated as the hardness of the carbon film.

Examples of the measuring device include "Hysitron Triboscope" manufactured by BRUKER.

The thickness of the carbon film is preferably 0.01 μm or more, more preferably 0.02 μm or more, and preferably 1 μm or less, more preferably 0.5 μm or less. When the thickness of the carbon film is greater than or equal to the lower limit and less than or equal to the upper limit, water vapor permeability can be suppressed even more effectively, and carbonation of concrete can be suppressed even more effectively. .

(Other details of the protective sheet)
The thickness of the protective sheet is preferably 110 μm or more, more preferably 200 μm or more, and preferably 2000 μm or less, more preferably 1000 μm or less. When the thickness of the protective sheet is not less than the above lower limit and not more than the above upper limit, the effects of the present invention can be exhibited even more effectively.

The above-mentioned protective sheet can be produced, for example, as follows.

A material for the resin layer is placed on the first surface of the base material or on the surface of the carbon film opposite to the base material. Methods for arranging the material for the resin layer include coating, dipping, and spraying. Next, the material of the resin layer is cured. Note that the conditions for curing the material of the resin layer can be changed as appropriate depending on the type of curable component and the like.

(Structure with surface protection sheet)
A structure with a surface protection sheet according to the present invention includes a structure and the above-mentioned protection sheet, and the protection sheet is arranged on the surface of the structure. In the structure with a surface protection sheet, the protection sheet is adhered to the surface of the structure from the resin layer side. The resin layer and the surface of the structure are adhered to each other.

FIG. 1 is a cross-sectional view schematically showing a structure with a surface protection sheet according to a first embodiment of the present invention.

The structure 11 with a surface protection sheet includes a structure 10 and a protection sheet (surface protection sheet for structures) 4. A protective sheet 4 is arranged on the surface of the structure 10.

The protective sheet 4 includes a base material 1 , a carbon film 3 , and a resin layer 2 . A carbon film 3 is arranged on the first surface 1a of the base material 1, and a resin layer 2 is arranged on the surface of the carbon film 3 on the opposite side from the base material 1. Therefore, the resin layer 2 is arranged on the first surface 1a side of the base material 1.

When the surface of the resin layer 2 or the surface of the structure 10 comes into contact with moisture due to the influence of rainwater or water vapor in the air, carbonate ions or calcium ions contained in this moisture and compound X contained in the resin layer 2 The released carbonate ions or calcium ions undergo a chemical reaction, and calcium carbonate (cement) is generated at the contact surface between the resin layer 2 and the structure 10. That is, a calcium carbonate layer is generated between the surface of the structure 10 and the resin layer 2. The generated calcium carbonate protects the surface of the structure 10 even more strongly. Moreover, even if the protective sheet 4 is deteriorated by ultraviolet rays or the like, the surface of the structure 10 is strongly protected by the generated calcium carbonate. Therefore, by using the protective sheet 4, a decrease in the strength of the structure 10 can be considerably suppressed.

FIG. 2 is a cross-sectional view schematically showing a structure with a surface protection sheet according to a second embodiment of the present invention.

The structure 11A with a surface protection sheet includes a structure 10 and a protection sheet (surface protection sheet for structures) 4A. A protective sheet 4A is arranged on the surface of the structure 10.

The protective sheet 4A includes a base material 1A and a resin layer 2A. A resin layer 2A is placed directly on the first surface 1Aa of the base material 1A.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples. The invention is not limited only to the following examples.

The following materials were prepared.

(Base material)
Polyethylene terephthalate film (PET film, "X10S" manufactured by Toray Industries, thickness 0.125 mm)

(Material of resin layer)
Curable component:
Modified silicone-epoxy adhesive (mixture of 100 parts by weight of modified silicone compound and 70 parts by weight of epoxy compound)
Compound X:
Compound capable of releasing carbonate ions: Sodium bicarbonate

(Example 1)
Preparation of protective sheet:
50 parts by weight of sodium hydrogen carbonate was mixed with 100 parts by weight of the modified silicone-epoxy adhesive to obtain a material for the resin layer. The resin layer material was uniformly coated onto the first surface of the PET film using a rubber spatula to a thickness of 2 mm. Thereafter, it was left standing at 23° C. for 24 hours to harden the material of the resin layer. In this way, a protective sheet was produced.

(Example 2)
A protective sheet was obtained in the same manner as in Example 1, except that 100 parts by weight of sodium hydrogen carbonate was mixed with 100 parts by weight of the modified silicone-epoxy adhesive.

(evaluation)
(1) Immersion test The obtained protective sheet was cut into a length of 2 cm x width of 2 cm to prepare a test sample (test sample comprising a base material and a resin layer) weighing about 2 g. The weight of this test sample was taken as the weight of the test sample before immersion. The test sample was then immersed in 100 g of a 4% by weight calcium chloride solution (assuming 100 times the concentration of seawater). After 5, 14, and 21 days of immersion, the test samples were taken out and their weights were measured. The weight increase rate of the test sample was determined based on the test sample before immersion.

The results are shown in Table 1.

In the test samples obtained in Examples 1 and 2, the weight tended to increase as the immersion time became longer. Furthermore, when the test samples obtained in Examples 1 and 2 were observed 21 days after immersion, the surface of the resin layer had turned gray (cement color). On the other hand, there was no change in the surface of the base material. Therefore, it is considered that the weight of the test samples obtained in Examples 1 and 2 increased due to the calcium carbonate formed on the surface of the resin layer.

1,1A...Base material 1a,1Aa...First surface 2,2A...Resin layer 3...Carbon film 4,4A...Protection sheet (surface protection sheet for structures)
10... Structure 11, 11A... Structure with surface protection sheet

Claims (8)

A surface protection sheet for protecting the surface of a structure,
base material and
Equipped with a resin layer containing a compound capable of releasing carbonate ions ,
The compound capable of releasing carbonate ions is sodium carbonate or sodium hydrogen carbonate,
The material of the resin layer contains a curable component,
A surface protection sheet for a structure, wherein the content of the compound capable of releasing carbonate ions is 50 parts by weight or more based on 100 parts by weight of the curable component in the material of the resin layer . the resin layer is arranged on the first surface side of the base material,
The surface protection sheet for structures according to claim 1 , wherein the resin layer is an adhesive resin layer. The surface protection sheet for structures according to claim 1 or 2, wherein the curable component contains a modified silicone compound and an epoxy compound. The surface protection sheet for structures according to any one of claims 1 to 3, wherein the curable component contains a modified silicone compound, an epoxy compound, a silanol condensation catalyst, and an epoxy curing agent. The surface protection for structures according to claim 3 or 4, wherein in the material of the resin layer, the content of the epoxy compound is 1 part by weight or more and 100 parts by weight or less with respect to 100 parts by weight of the modified silicone compound. sheet. The surface protection sheet for structures according to any one of claims 1 to 5 , wherein the base material contains polyethylene terephthalate, polypropylene, or polyethylene. The surface protection sheet for structures according to any one of claims 1 to 6 , comprising a carbon film on the surface of the base material. structure and
and a surface protection sheet for structures according to any one of claims 1 to 7 ,
A structure with a surface protection sheet, wherein the surface protection sheet for structures is disposed on a surface of the structure.

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