JP7300883B2 - Steel covering laminate, steel structure provided with said laminate, and method for protecting or repairing steel structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a steel coating laminate that can be applied to protect or repair steel structures that are exposed to the outdoors. The present invention also relates to a steel structure comprising said laminate. The present invention also relates to a method for protecting or repairing a steel structure using the laminate.

Steel structures such as bridges, sluice gates, buildings, offshore structures, and plants where the main members are made of steel are often installed in an exposed state, and the steel is damaged by the adhesion of moisture and salt. Easy to rust and corrode. When the steel material rusts or corrodes, the thickness of the steel material is partially reduced, and there is a concern that the strength of the steel material may be lowered. Therefore, steel structures installed in an exposed state are generally protected from rust and corrosion by anticorrosive coating using fluororesin or the like (Patent Document 2: JP 2018-135645, Patent Document 8 : JP-A-2008-087242, Patent Document 10: JP-A-2012-143668, Patent Document 12: JP-A-2018-140351)

In addition, there are various techniques for protecting a metal substrate by attaching a metal or resin sheet or the like to the surface of various structures (Patent Document 1: International Publication No. 2016/010013, Patent Document 3: Patent Document 3: JP 2013-071267, Patent Document 4: JP 2005-200958, Patent Document 5: JP H11-262977, Patent Document 6: JP 2000-280402, Patent Document 7: JP 2004 -058583, Patent Document 9: JP-A-2009-138214, Patent Document 11: International Publication No. 2016/152631, Patent Document 13: JP 2018-517000).

WO2016/010013 JP 2018-135645 A JP 2013-071267 A Japanese Patent Application Laid-Open No. 2005-200958 JP-A-11-262977 Japanese Patent Application Laid-Open No. 2000-280402 JP-A-2004-058583 JP 2008-087242 A JP 2009-138214 A JP 2012-143668 A WO2016/152631 JP 2018-140351 A Japanese Patent Application Publication No. 2018-517000

However, even if a steel structure installed exposed to the outdoors is protected by coating, it is inevitable that the coating will fade due to deterioration over time. In particular, it is difficult to ensure the coating thickness at the corners (edge surfaces) of the member, and there is a problem that expected durability (for example, 30 years or more) cannot be obtained. Also, the welded portion has the same problem as the corner portion (edge surface) of the member. When the paint fades, that is, when the paint deteriorates over time, there is a risk of deterioration in appearance and exposure of the steel material to rust and corrosion.

Sheets for protecting various structural parts have also been proposed, but they can be easily applied to steel structures that are exposed to the outdoors, especially painted steel structures, and are effective in preventing corrosion on the surface of steel materials. Sheets with excellent properties and weatherability (resistance to fading) have not yet been clarified.

In view of the above circumstances, it is an object of the present invention to provide a laminate that can be easily attached to a steel structure that is installed in an exposed state and that has excellent corrosion resistance and weather resistance on the surface of the steel material. Make it one of the tasks. Another object of the present invention is to provide a steel structure having such a laminate. Another object of the present invention is to provide a method for protecting or repairing steel structures.

The inventors of the present invention conducted various studies to achieve the above problems, and as a result, put a laminate comprising at least a fluororesin layer and an adhesive layer in this order outdoors with the adhesive layer as the attachment side. The present inventors have found that the above-mentioned problems can be achieved by applying the adhesive to the surface of steel materials used in steel structures that are installed in an exposed state, and have arrived at the present invention exemplified below.

[1]
A fluorine-based resin layer and an adhesive layer containing one or both selected from the group consisting of polyvinylidene fluoride resin and ethylene-chlorotrifluoroethylene copolymer are provided in this order, and installed in a state of being exposed to the outdoors. A laminate for covering steel materials, which is used by attaching an adhesive layer to the surface of steel materials constituting a steel structure.
[2]
The laminate for covering steel materials according to [1], which is used by being attached to the surface of a steel material coated with paint.
[3]
The steel coating laminate according to [2], wherein the paint contains one or more selected from the group consisting of fluororesin paint, polyurethane resin paint, and epoxy resin paint.
[4]
The steel coating laminate according to [2] or [3], wherein the surface of the steel coated with the paint has a water contact angle of less than 90° measured according to the sessile drop method specified in JIS R3257:1999. body.
[5]
The steel coating laminate according to any one of [1] to [4], which has a total light transmittance of 90% or more measured according to the measuring method specified in JIS K7361-1-1997.
[6]
The steel covering laminate according to any one of [1] to [5], which has a HAZE of 60% or less as measured according to the measurement method specified in JIS K7136-2000.
[7]
The steel covering laminate according to any one of [1] to [6], wherein the pressure-sensitive adhesive layer contains a (meth)acrylic pressure-sensitive adhesive.
[8]
The steel coating laminate according to any one of [1] to [7], wherein the laminate is for steel corrosion protection.
[9]
The steel material according to any one of [1] to [8], wherein the fluororesin layer comprises at least the following A layer and B layer in this order, and is a laminate in which the B layer faces the adhesive layer. Coating laminate.
Layer A: A resin composition containing 50 parts by mass to 100 parts by mass of a polyvinylidene fluoride resin and 0 parts by mass to 50 parts by mass of a poly(meth)acrylic acid ester resin (total of both is 100 parts by mass) A layer of things.
B layer: resin composition containing 0 parts by mass or more and less than 50 parts by mass of polyvinylidene fluoride resin and more than 50 parts by mass and 100 parts by mass or less of poly(meth)acrylic acid ester resin (total of both is 100 parts by mass) A layer of things.
[10]
The steel coating laminate according to [9], wherein the total content of the polyvinylidene fluoride resin and the poly(meth)acrylic acid ester resin in the resin composition constituting the layer A is 80% by mass or more.
[11]
The steel covering laminate according to [9] or [10], wherein the total content of the polyvinylidene fluoride-based resin and the poly(meth)acrylic acid ester-based resin in the resin composition constituting the B layer is 80% by mass or more. body.
[12]
[ 9] The steel covering laminate according to any one of [11].
[13]
The steel coating laminate according to any one of [1] to [12], wherein the pressure-sensitive adhesive layer is a two-component mixed pressure-sensitive adhesive.
[14]
A steel structure comprising the steel covering laminate according to any one of [1] to [13], wherein the surface of the steel material constituting the steel structure installed in a state of being exposed to the outdoors, A steel structure to which the steel covering laminate is attached with the pressure-sensitive adhesive layer on the attachment side.
[15]
The pressure-sensitive adhesive layer is attached to the surface of the steel material constituting the steel structure installed in the state where the steel material coating laminate according to any one of [1] to [13] is exposed to the outdoors. As a method for protecting or repairing a steel structure comprising the step of affixing.
[16]
A method for protecting or repairing a steel structure according to [15], comprising the following step 1.
Step 1: A step of attaching the steel coating laminate according to any one of [1] to [13] to the corners (edge surfaces) of the steel members constituting the steel structure.
[17]
In step 1, by folding the steel covering laminate, the steel covering laminate is attached across at least a part of each of a pair of opposing flat surfaces adjacent to the corners (edge surfaces) of the member. A method for protecting or repairing a steel structure according to [16], comprising:
[18]
A method for protecting or repairing a steel structure according to any one of [15] to [17], comprising the following step 2.
Step 2: A step of attaching the steel covering laminate according to any one of [1] to [13] to the welded portion of the steel constituting the steel structure.
[19]
Step 2 includes attaching the steel covering laminate across at least a portion of each of the planar portions of the two members joined via the weld by bending the steel covering laminate. A method for protecting or repairing a steel structure according to [18].
[20]
A method for protecting or repairing a steel structure according to any one of [16] to [19], comprising the following step 3.
Step 3: After step 1 or/and step 2, the step of attaching the steel material coating laminate according to any one of [1] to [13] to the flat portion of the steel material constituting the steel structure. A step of superimposing and pasting onto the end portion of the steel covering laminate pasted in step 1 or/and step 2.
[21]
The method for protecting or repairing a steel structure according to any one of [15] to [20], comprising a step of subjecting the surface of the steel material to keren treatment before the affixing step.

Since the laminate according to one embodiment of the present invention can be attached to a steel structure that is installed in an exposed state to the outdoors, it is possible to secure the coating film thickness at the corners (edge surfaces) and welds of members. Even in difficult places, coating can be easily applied. In addition, the laminate has excellent corrosion resistance and weather resistance on the surface of the steel material. For this reason, the steel structure having the laminate attached to the surface is prevented from deteriorating over a long period of time, and maintenance work for the steel structure can be reduced.

In addition, the laminate according to one embodiment of the present invention has good total light transmittance and/or HAZE, and the surface of the steel material can be easily visually recognized. For this reason, it is possible to grasp the state of the surface of the steel material without peeling off the laminate, and it becomes easy to carry out the deterioration predictive maintenance work of the steel structure. In addition, when the surface of the steel material is painted, the degree of deterioration over time of the painting and the steel structure can be easily determined from the degree of fading of the paint.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing a laminated structure of a steel covering laminate according to an embodiment of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing a laminated structure of a steel structure to which a steel covering laminate according to one embodiment of the present invention is attached; Schematic when the steel material covering laminate according to one embodiment of the present invention is attached to a corner portion (edge surface) of a steel material constituting a part of a steel structure installed in a state of being exposed to the outdoors. is a typical cross-sectional view. FIG. 4 is a schematic cross-sectional view when the steel material covering laminate according to one embodiment of the present invention is attached to a welded portion of a steel material constituting a part of a steel structure installed in a state of being exposed to the outdoors; be. It is a schematic diagram explaining the method of affixing and constructing an anti-corrosion sheet to T-shaped steel.

Embodiments of the present invention will be described below. The embodiments described below are illustrative of representative embodiments of the present invention, and are not intended to narrowly interpret the technical scope of the present invention.

<1. Laminate for steel material coating>
FIG. 1 shows a schematic cross-sectional view showing the laminated structure of a steel covering laminate (100) according to one embodiment of the present invention. The steel covering laminate (100) comprises at least a fluororesin layer (110) and an adhesive layer (120) in this order. Typically, the fluororesin layer (110) and the adhesive layer (120) are directly bonded without any other resin layer interposed between them. The steel material coating laminate (100) is attached to the surface of the steel material constituting the steel structure that is installed in a state of being exposed to the outdoors, with the adhesive layer (120) as the attachment side. It is possible to remarkably improve the corrosion resistance and weather resistance of the steel surface of the object.

The steel covering laminate (100) can be used, for example, to protect steel materials that constitute a new steel structure. By attaching the steel material covering laminate according to the present invention to the surface of the steel material that constitutes a newly installed steel structure, it is possible to improve corrosion resistance and weather resistance. In addition, the steel material covering laminate according to the present invention can be used for repairing the steel material that constitutes an existing steel structure. By attaching the steel material coating laminate according to the present invention to the steel material constituting the existing steel structure, it is possible to delay the deterioration of the steel material due to corrosion or rusting.

The surface of the steel material may be subjected to keren treatment before the steel material coating laminate according to the present invention is attached to the surface of the steel material. The surface of the steel material to be scraped may be painted. Removing rust from the surface of the steel material by scraping is advantageous in improving the adhesion of the steel material coating laminate, particularly when repairing the steel material constituting an existing steel structure.

The steel covering laminate (100) can be provided, for example, in the form of a sheet (including film and tape). It can also be provided as a long tape so that it can be easily attached to elongated portions such as member corners (edge surfaces) and welded portions, which will be described later. The long tape may be provided in a rolled state. The length of the long tape in the longitudinal direction is not particularly limited, and may be appropriately set in consideration of usability. It can also preferably be 10 to 30 m. The length of the long tape in the lateral direction (width direction) is not limited, but assuming that it is attached to the corner (edge surface) or welded part of the member, it can be, for example, 10 to 150 mm. , preferably 20 to 120 mm, more preferably 30 to 100 mm.

In one embodiment, the steel coating laminate (100) has a total light transmittance of 80% or more, preferably 90% or more ( For example, 90-99%). In one embodiment, the steel coating laminate (100) has a HAZE of 60% or less, preferably 50% or less, measured according to the measurement method specified in JIS K7136-2000. preferably 40% or less, still more preferably 30% or less, still more preferably 20% or less, still more preferably 10% or less, still more preferably 5% or less, for example 0 It can range from 0.1 to 60%. Total light transmittance and HAZE are parameters related to transparency, and high total light transmittance and low HAZE mean that the steel coating laminate has high transparency. As a result, deterioration of the steel structure can be visually confirmed even after the steel covering laminate is attached, which facilitates deterioration predictive maintenance work of the steel structure.

As will be described later, the steel material covering laminate (100) may be overlapped and pasted, for example, when it is pasted on the corner (edge face) of a member or when it is pasted on a welded part. Therefore, the surface of the steel covering laminate (100) opposite to the adhesive layer (120) is subjected to, for example, corona discharge treatment, plasma treatment (atmospheric pressure, and vacuum), high-frequency sputter etching, flame, itro, excimer UV, and primer. In addition, surface roughening treatment may be performed by physically scraping the surface with sandpaper, scraping, blasting, or the like. Examples of primers include acrylic primers, ethylene vinyl acetate primers, urethane primers, and epoxy primers. Acrylic primers are preferred from the viewpoint of increasing the adhesive strength between laminated sheets.

The surface of the steel covering laminate (100) opposite to the pressure-sensitive adhesive layer (120) is typically the surface of the fluorine-based resin layer (110), and the fluorine-based resin layer (110) is composed of a plurality of layers. is the surface of the layer A, which will be described later.

A separator (130) can be attached to the surface of the adhesive layer (120) on which the fluororesin layer (110) is not laminated until use. A known general separator can be used as the separator (130). Examples thereof include a PET sheet surface coated with a silicone release agent, and a paper/polyethylene laminate sheet coated with a silicone release agent on the polyethylene side (release paper). The separator (130) is peeled off at the time of construction, and then the steel material coating laminate (100 ) is pasted and installed.

(1-1. Fluorine resin layer)
The fluorine-based resin layer (110) contains one or both selected from the group consisting of polyvinylidene fluoride-based resin and ethylene-chlorotrifluoroethylene copolymer, so that the corrosion resistance and weather resistance of the surface of the steel material are significantly improved. It is preferable to improve the

Ethylene-chlorotrifluoroethylene copolymer (ECTFE) is a combination of ethylene (hereinafter sometimes referred to as "Et") and chlorotrifluoroethylene (also known as "trifluoroethylene chloride", hereinafter referred to as "CTFE"). is a copolymer of
In embodiments of the present invention, the ECTFE resin composition is not limited to a copolymer consisting only of Et and CTFE monomers. In addition to the Et monomer and CTFE monomer, ECTFE in the present embodiment includes, for example, (perfluorohexyl)ethylene, (perfluorobutyl)ethylene, (perfluorooctyl)ethylene, [4-(heptafluoroisopropyl)per Also included are copolymers using fluorobutyl]ethylene or the like as the third monomer.

The composition ratio (molar ratio) of each constitutional unit in the copolymerization of Et and CTFE can be measured by ¹⁹ F-NMR, FT-IR, or the like. The molar ratio of Et and CTFE in ECTFE (Et/CTFE ratio) is not particularly limited, but is preferably Et/CTFE = 30/70 to 70/30, more preferably 40/60 to 60/40. be. When the Et/CTFE ratio is 70/30 or less, the ratio of the CTFE monomer is relatively not excessively lowered, so that the characteristics of the fluororesin such as transparency, weather resistance, and antifouling properties are not impaired. can be done. Moreover, when the Et/CTFE ratio is 30/70 or more, it is possible to prevent the amount of acidic gas generated from becoming too high when used at high temperatures.

As the ECTFE used in the embodiment of the present invention, ECTFE having an arbitrary Et/CTFE ratio may be used alone, or two or more ECTFE having different Et/CTFE ratios may be mixed and used. Further, if necessary, a resin other than ECTFE may be added as long as the transparency of the ECTFE resin composition of the embodiment of the present invention is not impaired. As resins other than ECTFE, for example, polychlorotrifluoroethylene (PCTFE), ethylene-tetrafluoroethylene copolymer (ETFE), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymers, polytetrafluoroethylene (PTFE), polyhexafluoropropylene (HFP), polyperfluoroalkylvinyl ether (PFA), vinylidene fluoride, terpolymers of tetrafluoroethylene, vinylidene fluoride and hexafluoropropylene; be done.

The MFR of the ethylene-chlorotrifluoroethylene copolymer is preferably 2 to 50 g/10 minutes under the measurement conditions of 275° C. and a load of 2.16 kg in accordance with ISO1133. The higher the MFR, the higher the fluidity during melt extrusion, and therefore the moldability tends to improve. The lower the MFR, the higher the impact strength of the laminate. From the viewpoint of achieving both strength and moldability, the MFR is more preferably 4 to 30 g/10 minutes, still more preferably 10 to 30 g/10 minutes, and particularly preferably 15 to 26 g/10 minutes. A preferred embodiment of the polyvinylidene fluoride resin will be described later.

The thickness of the fluororesin layer (110) is preferably 20-200 μm, more preferably 25-150 μm, even more preferably 30-100 μm, and particularly preferably 40-75 μm. If the fluorine-based resin layer (110) is 20 μm or more, a high improvement effect in corrosion resistance, workability and weather resistance can be expected, and if it is 200 μm or less, the flexibility is increased, and even if there is an uneven surface, it can be formed into an uneven shape. It can be easily pasted by folding it together. The fluororesin layer (110) can be molded to a predetermined thickness using, for example, an extruder. At this time, it is preferable to adopt a mirror-finished pinch roll used for taking off the fluororesin layer in order to improve transparency.

Further, the surface of the fluororesin layer (110) on which the adhesive layer (120) is laminated is subjected to, for example, corona discharge treatment, plasma treatment ( atmospheric pressure and vacuum), high-frequency sputter etching, flame treatment, itro treatment, excimer UV treatment, primer treatment, and other surface treatments. In addition, surface roughening treatment may be performed by physically scraping the surface with sandpaper, scraping, blasting, or the like. Examples of primers include acrylic, ethylene-vinyl acetate, urethane, and epoxy primers, with acrylic primers being preferred.

The fluororesin layer (110) may be formed of a single layer, or may be formed of multiple layers. In a preferred embodiment, the fluororesin layer (110) comprises at least the following A layer (110a) and B layer (110b) in this order, with the B layer (110b) facing the adhesive layer (120) .
Layer A: A resin composition containing 50 parts by mass to 100 parts by mass of a polyvinylidene fluoride resin and 0 parts by mass to 50 parts by mass of a poly(meth)acrylic acid ester resin (total of both is 100 parts by mass) A layer of things.
B layer: resin composition containing 0 parts by mass or more and less than 50 parts by mass of polyvinylidene fluoride resin and more than 50 parts by mass and 100 parts by mass or less of poly(meth)acrylic acid ester resin (total of both is 100 parts by mass) A layer of things.

In one embodiment, the A layer includes a polyvinylidene fluoride resin of 50 parts by mass or more and 100 parts by mass or less and a poly(meth)acrylic acid ester resin of 0 parts by mass or more and 50 parts by mass or less (total of both is 100 parts by mass) ) is a layer made of a resin composition containing The mixing ratio of the polyvinylidene fluoride-based resin and the poly(meth)acrylic acid ester-based resin in the A layer is polyvinylidene fluoride-based resin: poly(meth)acrylic acid ester-based resin = 95 for a total of 100 parts by mass of both. ~55 parts by mass: preferably 5 to 45 parts by mass, more preferably 85 to 60 parts by mass: 15 to 40 parts by mass. When the polyvinylidene fluoride resin is 50 parts by mass or more with respect to the total 100 parts by mass of the polyvinylidene fluoride resin and the poly(meth)acrylic acid ester resin, properties such as weather resistance and stain resistance are improved. be able to. Further, by including a small amount of poly(meth)acrylic acid ester-based resin in the A layer, it is possible to improve the adhesiveness and adhesion with the B layer.

In addition to the polyvinylidene fluoride resin and the poly(meth)acrylic acid ester resin, the A layer contains other resins, plasticizers, heat stabilizers, antioxidants, light Stabilizers, crystal nucleating agents, anti-blocking agents, sealability improvers, release agents, colorants, pigments, foaming agents, flame retardants and the like can be contained as appropriate. However, in general, the total content of the polyvinylidene fluoride resin and the poly(meth)acrylic acid ester resin in the A layer is 80% by mass or more, typically 90% by mass or more, and more typically Typically, it is 95% by mass or more, and may be 100% by mass. The A layer may be formed as a single layer, or may be formed as a plurality of layers. Although the layer A may contain an ultraviolet absorber, it is preferable not to contain it from the viewpoint of cost and bleed-out.

In the present invention, the polyvinylidene fluoride resin refers to homopolymers of vinylidene fluoride, as well as copolymers of vinylidene fluoride and monomers copolymerizable with vinylidene fluoride. Examples of monomers copolymerizable with vinylidene fluoride include vinyl fluoride, ethylene tetrafluoride, propylene hexafluoride, isobutylene hexafluoride, ethylene trifluoride, various fluorinated alkyl vinyl ethers, and styrene. , ethylene, butadiene, and propylene, and the like, and these can be used alone or in combination of two or more. Among these, at least one selected from the group consisting of vinyl fluoride, ethylene tetrafluoride, propylene hexafluoride and ethylene trifluoride is preferable, and propylene hexafluoride is more preferable.

Polymerization reactions for obtaining polyvinylidene fluoride resins include known polymerization reactions such as radical polymerization and anionic polymerization. Further, the polymerization method includes known polymerization methods such as suspension polymerization and emulsion polymerization. The degree of crystallinity, mechanical properties, etc. of the resulting resin vary depending on the polymerization reaction and polymerization method.

The melting point of the polyvinylidene fluoride resin is preferably 150° C. or higher, more preferably 160° C. or higher. The upper limit of the melting point of polyvinylidene fluoride resin is preferably 170° C., which is equal to the melting point of polyvinylidene fluoride (PVDF).

The melting point of polyvinylidene fluoride resin can be measured by heat flux differential scanning calorimetry (heat flux DSC). For example, using a differential scanning calorimeter DSC3100SA manufactured by Bruker AXS, a sample mass of 1.5 mg, a DSC curve (first run) obtained when heating from room temperature to 200 ° C. at a heating rate of 10 ° C./min can be obtained from

The MFR of the polyvinylidene fluoride resin is preferably 5 to 50 g/10 minutes under measurement conditions of 230° C. and a load of 3.8 kg according to ISO1133. The higher the MFR, the higher the fluidity during melt extrusion, and therefore the moldability tends to improve. The lower the MFR, the higher the impact strength of the laminate. From the viewpoint of achieving both strength and moldability, the MFR is more preferably 5 to 30 g/10 minutes, still more preferably 10 to 30 g/10 minutes, and particularly preferably 15 to 26 g/10 minutes.

The lower limit of the weight average molecular weight (Mw) of the polyvinylidene fluoride resin is preferably 40,000 or more, more preferably 50,000 or more, and even more preferably 60,000 or more. The upper limit of the weight average molecular weight (Mw) of the polyvinylidene fluoride resin is preferably 1,000,000 or less, more preferably 500,000 or less, and even more preferably 350,000 or less. The higher the weight-average molecular weight (Mw), the higher the impact strength of the laminated sheet, and the lower the weight-average molecular weight (Mw), the higher the fluidity during melt extrusion, which tends to improve moldability. . From the viewpoint of achieving both strength and moldability, the weight average molecular weight (Mw) is preferably 40,000 to 1,000,000, more preferably 50,000 to 500,000, and more preferably 60,000 to 350,000. is more preferred.

The lower limit of the degree of dispersion (Mw/Mn, where Mn is the number average molecular weight) of the polyvinylidene fluoride resin is preferably 1.0 or more, more preferably 1.5 or more, and even more preferably 2.0 or more. . The upper limit of the dispersity (Mw/Mn) of the polyvinylidene fluoride resin is preferably 4.0 or less, more preferably 3.5 or less, and even more preferably 3.0 or less. The greater the degree of dispersion (Mw/Mn), the more the thickness accuracy of the laminate tends to improve, and the smaller the degree of dispersion (Mw/Mn), the better the fluidity during melt extrusion, resulting in improved moldability. tend to From the viewpoint of achieving both thickness accuracy and moldability, the degree of dispersion (Mw/Mn) is preferably 1.0 to 4.0, more preferably 1.5 to 3.5, and 2.0 to 3.0. is more preferred.

The weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (Mw/Mn) of the polyvinylidene fluoride resin can be measured using gel permeation chromatography (GPC). For example, N,N'-dimethylformamide containing 10 mmol/L lithium bromide is used as an eluent, and polyethylene oxide, polyethylene glycol and tetraethylene glycol are used as standard substances.

In the present invention, the poly(meth)acrylic acid ester resin is a homopolymer of (meth)acrylic acid ester such as methyl acrylate and methyl methacrylate, (meth)acrylic acid ester and (meth)acrylic acid ester. A copolymer of polymerizable monomers. Examples of monomers copolymerizable with (meth)acrylates include (meth)acrylates such as butyl (meth)acrylate and ethyl (meth)acrylate; styrene, α-methylstyrene, p-methyl Aromatic vinyl monomers such as styrene, o-methylstyrene, t-butylstyrene, divinylbenzene and tristyrene; Vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; Glycidyl group-containing such as glycidyl (meth)acrylate Monomers; vinyl carboxylate monomers such as vinyl acetate and vinyl butyrate; olefin monomers such as ethylene, propylene and isobutylene; diene monomers such as 1,3-butadiene and isoprene; maleic acid, Unsaturated carboxylic acid-based monomers such as maleic anhydride and (meth)acrylic acid; enone-based monomers such as vinyl methyl ketone; and the like, which can be used alone or in combination of two or more. . Among these, due to the compatibility with polyvinylidene fluoride resin, the strength of the laminate, and the adhesion and adhesion with the B layer, a homopolymer of methyl (meth) acrylate, or (meth) acrylic acid An acrylic rubber-modified acrylic copolymer obtained by copolymerizing an acrylic rubber mainly composed of butyl with a monomer mainly composed of methyl (meth)acrylate is preferable.

The copolymers include random copolymers, graft copolymers, block copolymers (e.g., diblock copolymers, triblock copolymers, linear types such as gradient copolymers, star copolymers polymerized by the arm-first method or the core-first method). polymers, etc.), copolymers (macromonomer copolymers) obtained by polymerization using a macromonomer, which is a polymer compound having a polymerizable functional group, and mixtures thereof. Among them, graft copolymers and block copolymers are preferable from the viewpoint of resin productivity.

Polymerization reactions for obtaining poly(meth)acrylic acid ester resins include known polymerization reactions such as radical polymerization, living radical polymerization, living anion polymerization, and living cationic polymerization. Moreover, the polymerization method includes known polymerization methods such as bulk polymerization, suspension polymerization, emulsion polymerization, and solution polymerization. Polymerization reactions and polymerization methods change the mechanical properties of the resulting resin.

The MFR of the poly(meth)acrylic acid ester-based resin is preferably 2 to 30 g/10 minutes under measurement conditions of 230° C. and a load of 10 kg in accordance with ISO1133. The higher the MFR, the higher the fluidity during melt extrusion, and therefore the moldability tends to improve. The lower the MFR, the higher the impact strength of the laminated sheet. From the viewpoint of achieving both strength and moldability, the MFR is more preferably 3 to 20 g/10 minutes, still more preferably 4 to 15 g/10 minutes, and particularly preferably 5 to 10 g/10 minutes.

The lower limit of the weight average molecular weight (Mw) of the poly(meth)acrylic acid ester resin is preferably 50,000 or more, more preferably 70,000 or more, and even more preferably 100,000 or more. The upper limit of the weight average molecular weight (Mw) of the poly(meth)acrylic acid ester resin is preferably 1,000,000 or less, more preferably 750,000 or less, and even more preferably 500,000 or less. In order to maintain the impact strength of the laminate, the higher the weight-average molecular weight (Mw), the better, and the lower the weight-average molecular weight (Mw), the better the fluidity during melt extrusion, so the moldability tends to improve. From the viewpoint of achieving both strength and moldability, the weight average molecular weight (Mw) is preferably 50,000 to 1,000,000, more preferably 70,000 to 750,000, and more preferably 100,000 to 500,000. More preferred.

The lower limit of the degree of dispersion (Mw/Mn, where Mn is the number average molecular weight) of the poly(meth)acrylic acid ester resin is preferably 1.0 or more, more preferably 1.5 or more, and 2.0. The above is more preferable. The upper limit of the degree of dispersion (Mw/Mn) of the poly(meth)acrylic acid ester resin is preferably 4.0 or less, more preferably 3.5 or less, and even more preferably 3.0 or less. The greater the degree of dispersion (Mw/Mn), the more the thickness accuracy of the laminate tends to improve, and the smaller the degree of dispersion (Mw/Mn), the better the fluidity during melt extrusion, resulting in improved moldability. tend to From the viewpoint of achieving both thickness accuracy and moldability, the degree of dispersion (Mw/Mn) is preferably 1.0 to 4.0, more preferably 1.5 to 3.5, and 2.0 to 3.0. More preferred.

The weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (Mw/Mn) of the poly(meth)acrylic acid ester resin can be measured using gel permeation chromatography (GPC). For example, tetrahydrofuran can be used as an eluent and polystyrene can be used as a standard.

In the acrylic rubber-modified acrylic copolymer, the volume median particle diameter of the rubber-like dispersed particles forming the dispersed phase is preferably 5.0 μm or less. The larger the volume median particle size, the more superior the impact strength of the laminate, and the smaller the volume median particle size, the more superior the transparency. From the viewpoint of achieving both strength and transparency, the volume median particle size is preferably 0.05 to 3.0 μm, more preferably 0.1 to 2.0 μm, and particularly preferably 0.5 to 1.5 μm.

Methods for adjusting the volume-median particle size of the rubber-like dispersed particles include a method of adjusting the stirring speed in the phase inversion region of the rubber particles in the polymerization step, a method of adjusting the amount of the chain transfer agent in the raw material liquid, and the like. mentioned.

The volume-median particle size of the rubber-like dispersed particles can be obtained, for example, by dissolving an acrylic rubber-modified acrylic copolymer in an electrolytic solution (3% tetra-n-butylammonium/97% dimethylformamide solution) and using the Coulter Multisizer method. (Multisizer II manufactured by Coulter; orifice diameter of aperture tube: 30 μm).

The thickness of layer A is preferably 5 to 70 μm, more preferably 9 to 50 μm, even more preferably 15 to 34 μm, particularly preferably 15 to 25 μm. When the A layer is 5 μm or more, the function as a protective layer can be improved, and when it is 70 μm or less, cost reduction can be realized. The layer A may be formed as a single layer or a plurality of layers, but it is desirable that the total thickness is within the thickness described above.

The surface of the A layer on which the B layer is laminated is subjected to, for example, corona discharge treatment, plasma treatment (atmospheric pressure and vacuum), high frequency sputter etching treatment, Surface treatments such as flame treatment, itro treatment, excimer UV treatment, and primer treatment may be applied. Further, surface roughening treatment may be performed by physically scraping the surface with sandpaper, scraping, blasting, or the like. Examples of primers include acrylic primers, ethylene vinyl acetate primers, urethane primers, and epoxy primers. Acrylic primers are preferred from the viewpoint of increasing the adhesive strength with the B layer.

In one embodiment, the B layer is a polyvinylidene fluoride resin of 0 parts by mass or more and less than 50 parts by mass and a poly(meth)acrylic acid ester resin of more than 50 parts by mass and 100 parts by mass or less (total of both is 100 parts by mass) ) is a layer made of a resin composition containing The mixing ratio of the polyvinylidene fluoride-based resin and the poly(meth)acrylic acid ester-based resin in the B layer is polyvinylidene fluoride-based resin: poly(meth)acrylic acid ester-based resin = 5 with respect to a total of 100 parts by mass of both. ~45 parts by mass: preferably 95 to 55 parts by mass, more preferably 15 to 40 parts by mass: 85 to 60 parts by mass. When the poly(meth)acrylic acid ester resin is more than 50 parts by mass with respect to the total of 100 parts by mass of the polyvinylidene fluoride resin and the poly(meth)acrylic acid ester resin, the adhesion with the adhesive layer is improved. can be made In addition, by including a small amount of polyvinylidene fluoride resin in the B layer, the weather resistance and the adhesiveness and adhesion to the A layer can be improved.

In addition to the polyvinylidene fluoride resin and the poly(meth)acrylic acid ester resin, the B layer contains an ultraviolet absorber, another resin, a plasticizer, a heat stabilizer, an oxidation An inhibitor, a light stabilizer, a crystal nucleating agent, an antiblocking agent, a sealability improving agent, a release agent, a coloring agent, a pigment, a foaming agent, a flame retardant, and the like can be appropriately contained. However, generally, the total content of the polyvinylidene fluoride-based resin and the poly(meth)acrylic acid ester-based resin in the B layer is 80% by mass or more, typically 90% by mass or more, and more typically Typically, it is 95% by mass or more, and may be 100% by mass.

The B layer preferably contains an ultraviolet absorber. By containing an ultraviolet absorber in the B layer, ultraviolet rays are blocked and the weather resistance can be effectively improved. Examples of UV absorbers include, but are not limited to, hydroquinone-based, triazine-based, benzotriazole-based, benzophenone-based, cyanoacrylate-based, oxalic acid-based, hindered amine-based, salicylic acid derivatives, and the like. Two or more kinds can be used in combination. Among them, benzotriazole-based and triazine-based compounds are preferable because of the durability of the ultraviolet shielding effect. The content of the ultraviolet absorber in the B layer is preferably 0.05 to 15 parts by mass with respect to the total 100 parts by mass of the polyvinylidene fluoride resin and the poly(meth)acrylic acid ester resin in the B layer. . The content of the ultraviolet absorber in the layer B is 0.05 parts by mass or more with respect to a total of 100 parts by mass of the polyvinylidene fluoride resin and the poly(meth)acrylic acid ester resin, preferably 1 By making it 2 parts by mass or more, more preferably 2 parts by mass or more, it is possible to expect further improvement in weather resistance, UV absorption effect, and further effect of suppressing deterioration of the steel material surface by imparting UV cut property. Further, the content of the ultraviolet absorber in the B layer is set to 15 parts by mass or less with respect to a total of 100 parts by mass of the polyvinylidene fluoride resin and the poly(meth)acrylic acid ester resin, preferably 10 parts by mass. By making it not more than 5 parts by mass, more preferably not more than 5 parts by mass, it is possible to prevent the UV absorber from bleeding out to the surface of the laminate, prevent deterioration of adhesion with the A layer, and reduce the cost. reduction can be realized.

The thickness of the B layer is preferably 10-140 μm, more preferably 16-100 μm, even more preferably 27-66 μm, and particularly preferably 27-50 μm. When the thickness of the B layer is 10 μm or more, the adhesion with the pressure-sensitive adhesive layer (120) can be improved, and when the thickness is 140 μm or less, cost reduction can be realized. The B layer may be formed as a single layer or as a plurality of layers, but it is desirable that the total thickness is within the thickness described above.

A laminate in which the A layer and the B layer are laminated can be produced, for example, by a coextrusion molding method in which a plurality of resins are adhesively laminated in a molten state using a plurality of extruders. The co-extrusion molding method includes a multi-manifold die method in which each layer is contacted and bonded at the tip of the T-die after making multiple resins into a sheet, and a sheet after bonding multiple resins in a confluence device (feed block). There is a feed block die method that spreads into a shape, and a dual slot die method that adheres each layer by contacting each layer at the tip of the outside of the T die after forming a plurality of resins into a sheet. It can also be manufactured by an inflation molding method using a round die.

Also, it is called an extrusion lamination method, in which one of the layers to be integrally bonded is formed into a film in advance, and the other layer is extruded with heat or adhesive (generally in advance). It is also possible to adopt a method of crimping by applying an agent). Furthermore, there is also a method in which both layers are formed into a film in advance and then both layers are integrated using heat or an adhesive agent, but this method is disadvantageous compared to the above method from the viewpoint of the number of steps and cost. .

When forming a laminate in which the A layer and the B layer are laminated, in order to increase the transparency of the laminate, it is preferable to adopt a mirror-finished pinch roll used for taking up the laminate.

<1-2. Adhesive layer>
The adhesive layer (120) is a layer composed of an adhesive, and has a function of ensuring adhesion between the steel material coating laminate when the steel material coating laminate is attached to the surface of the steel material. The adhesive layer (120) is preferably transparent in order to enhance the visibility of the steel surface. The reason why the adhesive is used in the present invention is that the workability is significantly higher than that of the adhesive. The difference between a pressure-sensitive adhesive and an adhesive is that the pressure-sensitive adhesive is a gel-like soft solid from the time it is attached, and while it is in that state, it spreads over the adherend, does not change its shape, and has the ability to resist peeling. In other words, the pressure-sensitive adhesive develops adhesive strength that can withstand practical use as soon as it is pasted together. It is a point that it changes to , strongly binds at the interface, and exerts a force to resist peeling. After bonding, the adhesive requires time for the adhesive to solidify due to a chemical reaction until it develops an adhesive strength that can withstand practical use.

The adhesive preferably has a storage modulus of 1.0×10 ⁴ to 1.0×10 ⁶ Pa at 25° C. and 1.0 Hz and a tan δ of 0.6 or less at 100° C. and 1.0 Hz. More preferably, the storage modulus at 25° C. and 1.0 Hz is 5.0×10 ⁴ to 5.0×10 ⁵ Pa, and the tan δ at 100° C. and 1.0 Hz is 0.4 or less. When the storage modulus is 1.0×10 ⁴ Pa or more, the cohesive force of the adhesive is improved, and after the adhesive film is attached to the adherend, the adhesive film is prevented from slipping or peeling off from the adherend. can do. Further, when the storage elastic modulus is 1.0×10 ⁶ Pa or less, the pressure-sensitive adhesive has appropriate flexibility and can improve conformability to unevenness of the adherend. When the tan δ is 0.6 or less, the heat resistance is improved, and after the adhesive film is attached to the adherend, the pressure-sensitive adhesive film is prevented from being displaced from the adherend or peeled off due to heat such as sunlight. can do.

The storage modulus and tan δ can be measured using a viscoelasticity measuring device manufactured by Rheometric Scientific. The storage elastic modulus in the present invention is the storage elastic modulus G' at 25°C in the shear mode and the frequency of 1.0 Hz, and tan δ is the storage elastic modulus G' and the loss elastic modulus at 100°C in the shear mode and the frequency of 1.0 Hz. The value was obtained from the ratio (G''/G') of the rate G''.

The thickness of the adhesive layer (120) is not particularly limited. However, when the thickness of the pressure-sensitive adhesive layer (120) becomes small, the adhesion to the surface of the steel material tends to decrease. Since the adherence to the adhesive layer (120) decreases, air bubbles tend to enter between the adhesive layer (120) and the surface of the steel material, and the appearance tends to deteriorate. It is more preferably 15 μm or more, and particularly preferably 20 μm or more. When the thickness of the pressure-sensitive adhesive layer (120) exceeds 150 μm, various performances attributed to the pressure-sensitive adhesive layer (120) tend to peak and the cost increases, so the thickness is preferably 150 μm or less. , is more preferably 110 μm or less, even more preferably 100 μm or less, and particularly preferably 75 μm or less. From these viewpoints, the thickness of the adhesive layer (120) is preferably 5 to 150 μm, more preferably 10 to 110 μm, even more preferably 15 to 100 μm, and 20 to 75 μm. It is particularly preferred to have In addition, the said thickness means the thickness (micrometer/Dry) after drying of an adhesive layer (120).

Examples of adhesives include rubber-based adhesives, (meth)acrylic-based adhesives, silicone-based adhesives, urethane-based adhesives, vinyl alkyl ether-based adhesives, polyvinyl alcohol-based adhesives, polyvinylpyrrolidone-based adhesives, poly Acrylamide-based adhesives, cellulose-based adhesives, and the like can be mentioned. Such pressure-sensitive adhesives may be used alone or in combination of two or more.

Adhesives can be classified into hot-melt adhesives, two-component mixed adhesives, thermosetting adhesives, UV-curable adhesives, etc., according to the type of adhesive, and among these, ease of handling and stability A two-liquid mixed pressure-sensitive adhesive can be suitably used for the reason that the adhesive strength is developed as described above.

Among these, a two-liquid mixed type (meth)acrylic pressure-sensitive adhesive can be suitably used from the viewpoint of being transparent and having excellent adhesiveness. (Meth)acrylic means both acrylic and methacrylic. "The pressure-sensitive adhesive layer contains a (meth)acrylic pressure-sensitive adhesive" means that the pressure-sensitive adhesive layer contains one or both of an acrylic pressure-sensitive adhesive and a methacrylic pressure-sensitive adhesive. Details of the (meth)acrylic pressure-sensitive adhesive preferably used in the present invention are described in International Publication No. 2016/010013.

Specific examples of (meth)acrylic adhesives include ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, and n-pentyl (meth)acrylate. , 2-methylbutyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate ) at least one C ₂ -C ₁₂ alkyl ester of (meth)acrylic acid such as acrylate (monomer A), acrylic acid, methacrylic acid, acrylamide, N-methylolacrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate; A copolymer with at least one functional group-containing acrylic monomer (monomer B) can be preferably used. The copolymerization ratio of the monomer A and the monomer B is expressed as a mass ratio in a total of 100 parts by mass of the monomer A and the monomer B, and the monomer A/monomer B = 99.9/0.1 to 70/30, It is preferably in the range of 99/1 to 75/25.

Particularly preferred (meth)acrylic copolymers include copolymers of butyl acrylate (BA) and acrylic acid (AA). In this case, the copolymerization ratio of butyl acrylate (BA) and acrylic acid (AA) is BA/AA = 99.9/0.1 to 70/30, expressed as a mass ratio in 100 parts by mass of BA and AA total. and preferably in the range of 99.5/0.5 to 80/20. When AA is 0.1 parts by mass or more in the total of 100 parts by mass of BA and AA, it becomes easy to control adhesive physical properties in combination with a cross-linking agent. In addition, when AA is 30 parts by mass or less in the total of 100 parts by mass of BA and AA, the glass transition point (Tg) is lowered, the adhesion to the steel material surface at low temperatures is improved, and workability is improved.

The weight average molecular weight (Mw) of the (meth)acrylic copolymer is preferably 200,000 to 1,000,000, more preferably 400,000 to 800,000. and by adding a chain transfer agent. When the weight-average molecular weight (Mw) is 200,000 or more, the cohesion of the (meth)acrylic copolymer is improved, and adhesive residue on structures and peeling of the adhesive sheet can be prevented. Further, when it is 1,000,000 or less, the (meth)acrylic copolymer has appropriate flexibility, and the conformability to irregularities on the surface of the steel material is improved.

Additives such as a cross-linking agent, a tackifier, an ultraviolet absorber, and a light stabilizer can be added to the pressure-sensitive adhesive as necessary.

Examples of cross-linking agents include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, and amine-based cross-linking agents. These may be used alone or in combination of two or more. A particularly suitable cross-linking agent is an isocyanate-based cross-linking agent. parts by mass, preferably 0.5 to 3 parts by mass. When the isocyanate-based cross-linking agent is 0.3 parts by mass or more, the cohesive force of the adhesive is improved, and when the adhesive sheet is peeled off from the structure, it is possible to prevent adhesive residue on the structure and improve the removability. can be done. In addition, when the isocyanate-based cross-linking agent is 4 parts by mass or less, the pressure-sensitive adhesive has appropriate flexibility, improves conformability to the unevenness of the surface of the structure, and prevents air bubbles from being involved when the pressure-sensitive adhesive sheet is attached. can do.

Specific examples of isocyanate-based cross-linking agents include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, and diphenylmethane-4,4'-diisocyanate. , diphenylmethane-2,4′-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, dicyclohexylmethane-2,4′-diisocyanate, polyvalent isocyanate such as lysine isocyanate compounds and the like. These may be used alone or in combination of two or more.

When the pressure-sensitive adhesive contains a crosslinked (meth)acrylic copolymer, the degree of cross-linking (gel fraction) of the pressure-sensitive adhesive is not particularly limited, but is preferably 10% by mass or more, and more preferably 15% by mass or more. Preferably, 20% by mass or more is more preferable, and 25% by mass or more is particularly preferable. The degree of cross-linking (gel fraction) of the adhesive is preferably 80% by mass or less, more preferably 75% by mass or less, still more preferably 70% by mass or less, and particularly preferably 60% by mass or less. That is, the degree of crosslinking (gel fraction) of the adhesive is, for example, preferably 10 to 80% by mass, more preferably 15 to 75% by mass, still more preferably 20 to 70% by mass, and particularly preferably 25 to 60% by mass. . The degree of cross-linking (gel fraction) can be adjusted by, for example, selecting the composition and molecular weight of the (meth)acrylic copolymer base polymer (adhesive), the presence or absence of cross-linking agents, their types, and the amounts used. can be done. In principle, the upper limit of the degree of cross-linking is 100% by mass.

The tackifier can be selected in consideration of the softening point, compatibility with each component, and the like. Examples include terpene resins, rosin resins, hydrogenated rosin resins, coumarone-indene resins, styrene resins, aliphatic petroleum resins, alicyclic petroleum resins, terpene-phenolic resins, xylene resins, and other aliphatic hydrocarbon resins. Alternatively, aromatic hydrocarbon resins and the like may be mentioned. These may be used alone or in combination of two or more.

The ultraviolet absorber can be selected in consideration of the ultraviolet absorbability, compatibility with the (meth)acrylic pressure-sensitive adhesive to be used, and the like. Examples thereof include hydroquinone-based, benzotriazole-based, benzophenone-based, triazine-based, and cyanoacrylate-based. These may be used alone or in combination of two or more.

The light stabilizer can be selected in consideration of compatibility with the (meth)acrylic pressure-sensitive adhesive to be used, thickness, and the like. Examples thereof include hindered amine compounds, hindered phenol compounds, benzoate compounds, nickel complex compounds and the like. These may be used alone or in combination of two or more.

An adhesive layer can be formed by a general method. For example, there is a method (direct coating method) in which an adhesive is directly applied to the bonding surface of the fluororesin layer with the adhesive layer and then dried. There is also a method of applying an adhesive to the separator, drying it, and bonding it to the fluororesin layer.

The adhesive can be applied using conventionally known coating devices such as gravure roll coaters, die coaters, bar coaters, doctor blades, comma coaters and reverse coaters. Alternatively, the adhesive may be applied by impregnation, curtain coating, or the like. The pressure-sensitive adhesive may be applied while cooling, heating, or electron beam irradiation, if necessary.

Drying after coating the adhesive is preferably carried out under heating from the viewpoint of promoting the cross-linking reaction, improving production efficiency, and the like. The drying temperature is, for example, 40° C. or higher (usually 60° C. or higher), preferably about 150° C. or lower (usually 130° C. or lower).

In the step of forming the pressure-sensitive adhesive layer, after the pressure-sensitive adhesive is applied and dried, further adjustment of component migration in the pressure-sensitive adhesive layer, progress of the cross-linking reaction, and distortion that may exist in the steel coating laminate Aging may be performed for the purpose of alleviating the

<2. Steel structure provided with steel covering laminate>
According to one embodiment of the present invention, as shown in FIG. 2, a pressure-sensitive adhesive layer (120) is attached to the surface of a steel material (200) that constitutes a steel structure that is installed in a state of being exposed to the outdoors. As a steel structure to which the steel material covering laminate (100) is attached is provided. The surface of the steel material that constitutes the steel structure that is installed exposed to the outdoors may not be coated with paint, but it is generally coated with paint, and typically with anticorrosive paint. be. For this reason, the surface of steel materials is generally protected with a coating film, typically an antirust coating film. In one embodiment, the steel material coating laminate (100) has the advantage that it can be attached even if the surface of the steel material to which the paint is applied has properties close to a water-repellent area. In one embodiment, the steel surface to which the paint is applied has a water contact angle of less than 90° measured according to the sessile drop method specified in JIS R3257:1999. The contact angle is preferably 60° or more and less than 90°, more preferably 70° or more and 85° or less.

Examples of antirust paints include, but are not limited to, fluorine resin paints, polyurethane resin paints, and epoxy resin paints. Although these may be used alone, it is preferable to use them in combination in order to improve anti-corrosion properties. Before coating, it is preferable to pre-treat the surface of the steel material by blasting or the like in order to improve the adhesion of the coating.

There are no particular restrictions on steel structures that are exposed to the outdoors. Car parks, fences, roofs (for example, structures that support nets for preventing balls from being thrown into highways from golf courses), undulating gates, and the like. A steel structure installed in the open air is exposed to an environment that is likely to corrode due to the adhesion of moisture and salt.

In a preferred embodiment, the surface of the steel material constituting the steel structure installed in the state exposed to the outdoors is coated with a heavy anti-corrosion coating consisting of four layers: an anti-corrosion base, an undercoat layer, an intermediate coat layer, and a top coat layer. can apply. Paints for anticorrosion substrates include, for example, inorganic zinc-rich paints and organic zinc-rich paints. Examples of paints that form the undercoat layer include epoxy resin paints. Examples of paints that form the intermediate coating include epoxy resin paints and fluororesin paints. Examples of paints that form the overcoat layer include fluororesin paints and polyurethane resin paints. The paints forming each layer may be used alone, or may be used in combination of multiple types.

In one embodiment, the steel covering laminate according to the present invention can exhibit high adhesion strength to the steel surface regardless of whether the steel surface is coated or not. Therefore, for example, the laminate for covering steel materials according to the present invention can be used by attaching it to the surface of a steel material to which paint has been applied, that is, so that the pressure-sensitive adhesive layer of the laminate for covering steel materials is in contact with the coated surface. can. In addition, the laminate for covering steel materials according to the present invention is used by attaching it to the surface of a steel material coated with a fluororesin paint, that is, so that the adhesive layer of the laminate for covering steel materials is in contact with the fluororesin coating film. can do. Moreover, the laminate for covering steel materials according to the present invention is attached to the surface of steel materials to which heavy anticorrosion coating has been applied, that is, the pressure-sensitive adhesive layer of the laminate for covering steel materials is in contact with the topcoat layer of the heavy anticorrosion coating. can be used for

On the surface of a steel material that constitutes a steel structure that is installed exposed to the outdoors, there are parts where it is easy to secure the desired coating thickness and parts where it is difficult to secure the desired coating thickness. . In steel structures that are exposed to the outdoors, rust and corrosion often occur starting from portions where it is difficult to ensure a coating film thickness. For this reason, it is preferable in protecting or repairing a steel structure to attach the steel material coating laminate according to the present invention to a portion where it is difficult to secure such a coating film thickness. Even if the steel coating laminate is not attached to the entire surface of the steel material that constitutes the steel structure, if the steel coating laminate can be attached to the part where it is difficult to secure the coating film thickness, a high protection or repair effect can be obtained. is obtained, it is economical.

Parts where it is difficult to ensure the coating film thickness include, but are not limited to, member corners (edge surfaces), welded parts, ridges, and corners (vertex parts of polygons). In addition, the member corner (edge surface) refers to an exposed plate thickness surface of the plate-shaped portion when the steel material constituting the steel structure has the plate-shaped portion. The length of the member corner (edge face) in the plate thickness direction is not limited, but is generally 1.6 to 100 mm, typically 9 to 50 mm.

When attaching the steel material covering laminate according to the present invention to the member corners (edge surfaces) of the steel materials constituting the steel structure, the steel material covering laminate is attached only to the member corners (edge surfaces). Although it is possible to attach it, it is more preferable to attach it across at least a part of each of a pair of adjacent flat portions in order to increase the durability of the steel structure. In FIG. 3, the steel material covering laminate (100) according to the present invention is shown in the member corner (edge surface) (edge surface) of the steel material (200) constituting a part of the steel structure installed in the state of being exposed to the outdoors. 212) is schematically shown. In the illustrated embodiment, a long tape-shaped steel covering laminate (100) is attached to the member corner (edge surface) (212). In addition, the long tape-shaped steel material covering laminate (100) is bent along the ridge (214), and has a pair of opposing planar portions ( 215a, 215b). With this configuration, the steel coating laminate (100) can be applied simultaneously to the member corners (edge surfaces) (212) and the ridges (214), which is efficient.

Furthermore, as described above, the steel material covering laminate (100) according to the present invention is added to the member corner (edge surface) (212) and a pair of members adjacent to the member corner (edge surface) (212) After pasting across at least a part of each of the flat portions (215a, 215b), as shown in FIG. The covering laminates (300a, 300b) may be attached to the plane portions (215a, 215b) of the steel material constituting the steel structure. As a result, the edge of the steel material covering laminate (100) previously attached to the corner (edge surface) (212) of the member is protected, so that it is difficult to peel off.

When attaching the steel material covering laminate according to the present invention to the welded portion of the steel material constituting the steel structure, it is possible to attach the steel material covering laminate only to the welded portion. It is more preferable in terms of increasing the durability of the steel structure to stick the steel material covering laminate over at least a part of each of the planar portions of the two members joined via the joint. FIG. 4 shows a welded portion (216) of a steel material (200) that constitutes a part of a steel structure (200) in which the steel material covering laminate (100) according to the present invention is exposed to the outdoors. The cross-sectional structure when attached to is schematically shown. In the illustrated embodiment, a long tape-like steel coating laminate (100) is attached to the weld (216). In addition, the long tape-shaped steel material covering laminate (100) is bent along the welded portion (216), and the flat portions (217a, 217a, 217b). Such a configuration ensures that the weld (216) is protected or repaired.

Furthermore, in addition to the welded portion (216), the flat portion (217a, 217b), and then, as shown in FIG. 400a, 400b) may be attached to the plane portions (217a, 217b) of the steel material (200) constituting the steel structure. As a result, the edge of the steel material covering laminate (100) previously attached to the welded portion (216) is protected, making it difficult to peel off.

EXAMPLES Hereinafter, the present invention will be described in detail based on examples while comparing with comparative examples.

(1. Material)
As a polyvinylidene fluoride resin, Arkema's product name Kynar720 (vinylidene fluoride homopolymer, MFR (ISO 1133 compliant, 230 ° C., 3.8 kg load): 18 to 26 g / 10 minutes, hereinafter abbreviated as "PVDF1" ) was prepared.
As a poly(meth)acrylic acid ester resin, Mitsubishi Chemical Corporation's product name Hipet HBS000Z60 (methyl methacrylate-butyl acrylate copolymer, MFR (ISO 1133 compliant, 230 ° C., 10 kg weight): 5 to 9 g / 10 minutes, hereinafter abbreviated as “Acrylic 1”) was prepared.
As the ethylene-chlorotrifluoroethylene copolymer, Solvay's product name Halar 500LC (MFR (ISO 1133 compliant, 275°C, 2.16 kg weight): 15 to 22 g/10 minutes, hereinafter abbreviated as "ECTFE1") is prepared. bottom.
As a polyvinyl chloride sheet, a product name Emron manufactured by Morino Kako Co., Ltd. (color: Tomei, surface finish: glossy, thickness: 50 μm, hereinafter abbreviated as “PVC1”) was prepared.
As a polyvinyl fluoride film, Tedlar SP (trade name: 25 μm thick, hereinafter abbreviated as “PVF1”) manufactured by DowDuPont was prepared.
As a polytetrafluoroethylene sheet, trade name NITOFLON No. 2 manufactured by Nitto Denko Corporation. 900UL (thickness 130 μm, hereinafter abbreviated as “PTFE1”) was prepared.
As an ethylene tetrafluoride-perfluoroalkoxyethylene copolymer sheet, a NEOFLON PFA film (thickness: 100 μm, hereinafter abbreviated as “PFA1”) manufactured by Daikin Industries, Ltd. under the trade name was prepared.
As an ethylene-tetrafluoroethylene copolymer film, Aflex 25N 1250S (trade name: 25 μm thick, hereinafter abbreviated as “ETFE1”) manufactured by AGC was prepared.
As a benzotriazole-based UV absorber, BASF's product name Tinuvin234 (hereinafter abbreviated as "UVA1") was prepared.
As a triazine-based ultraviolet absorber, BASF's product name Tinuvin 1577ED (hereinafter abbreviated as "UVA2") was prepared.

(2. Molding of single layer sheet)
<Molding Examples 1 to 5>
Blend at a predetermined ratio according to the molding number so that the content of each material with respect to the total mass of the resin composition constituting the single layer sheet is the value shown in Table 1, and φ30 mm counter-rotating twin screw extruder (manufactured by Kobe Steel, Ltd., KTX-30), the mixture was melt-kneaded under the conditions of an extrusion temperature of 240° C. and a screw rotation speed of 200 rpm, and extruded into a strand. After cooling the strand-shaped kneaded product, it was pelletized by a pelletizer.

A T-die with a lip width of 550 mm was attached to the tip of a short-screw extruder with a diameter of 40 mm. The extrusion temperature was 240°C, the T-die temperature was 240°C, and the cooling roll temperature was 30°C. A mirror-finished pinch roll was used.

<Molding example 6>
ECTFE1 was pelletized under the same conditions as in Molding Examples 1 to 5, except that the extrusion temperature was changed to 285°C. Next, the obtained pellets were subjected to single-layer extrusion molding under the same conditions as in Molding Examples 1 to 5, except that the extrusion temperature was changed to 285 ° C. and the T-die temperature was changed to 285 ° C., and the results shown in Table 1 were obtained. A thick monolayer sheet was formed.

<Molding example 7A>
PVC1 was used as is without further processing.

<Molding example 7B>
PVF1 was used as is without further processing.

<Molding example 7C>
PTFE1 was used as is without further processing.

<Molding example 7D>
PFA1 was used as is without further processing.

<Molding example 7E>
ETFE1 was used as is without further processing.

(3. Molding of two-layer sheet)
<Molding Examples 8 to 27, 29 to 33>
Blend at a predetermined ratio according to the molding number so that the content of each material with respect to the total mass of the resin composition constituting the A layer is the value shown in Table 2, and φ30 mm counter-rotating twin-screw extruder (Kobe Using KTX-30 manufactured by Steel Works Co., Ltd., the mixture was melt-kneaded under the conditions of an extrusion temperature of 240° C. and a screw rotation speed of 200 rpm, and extruded into a strand. After cooling the strand-shaped kneaded product, it was pelletized by a pelletizer.

Similarly, blend at a predetermined ratio according to the molding number so that the content of each material with respect to the total mass of the resin composition constituting the B layer is the value shown in Table 2, and φ 30 mm counter-rotating twin-screw extrusion Using a machine (KTX-30, manufactured by Kobe Steel, Ltd.), the mixture was melt-kneaded under conditions of an extrusion temperature of 240° C. and a screw rotation speed of 200 rpm, and extruded into a strand. After cooling the strand-shaped kneaded product, it was pelletized by a pelletizer.

The pellets for the layer A and the pellets for the layer B prepared above were extruded using a feed block type T die type multilayer extruder equipped with two φ40 mm short screw extruders, a feed block at the tip, and a T die with a lip width of 550 mm. Two types of two-layer co-extrusion molding was carried out using the above method to obtain various sheet-like moldings in which the A layer and the B layer were laminated with the thickness shown in Table 2. Extrusion of the A layer and the B layer was carried out under the conditions of an extrusion temperature of 240°C and a T-die temperature of 240°C. The temperature of the pinch roll closest to the die of the take-up device was set at 30°C. The pinch rolls used were either mirror-finished or embossed, depending on the molding number.

<Molding example 28>
ECTFE1 constituting the A layer was pelletized under the same conditions as in Molding Examples 8 to 27 and 29 to 33, except that the extrusion temperature was changed to 285°C.

ECTFE1 and UVA1 constituting the B layer were blended at the ratio shown in Table 2, and pelletized under the same conditions as in Molding Examples 8 to 27 and 29 to 33, except that the extrusion temperature was changed to 285°C.

Under the same conditions as in Molding Examples 8 to 27 and 29 to 33, except that the extrusion temperature was changed to 285 ° C. and the T die temperature was changed to 285 ° C. for the A layer pellets and B layer pellets produced above. A two-kind two-layer coextrusion molding was carried out to obtain a sheet-shaped molding in which the A layer and the B layer were laminated with the thickness shown in Table 2. A mirror-finished pinch roll was used.

(4. Preparation of adhesive)
Adhesive 1: Adhesive 1 was prepared by blending 100 parts by mass of the acrylic adhesive shown in Table 3 with the isocyanate cross-linking agent shown in Table 3 in the parts by weight shown in Table 3.
Adhesive 2: Adhesive 2 was prepared by blending 100 parts by mass of the acrylic adhesive shown in Table 3 with the isocyanate cross-linking agent shown in Table 3 in the parts by weight shown in Table 3.
Adhesive 1: 66.7 parts by mass of the epoxy adhesive (main agent) shown in Table 3 and the amine curing agent (secondary material) shown in Table 3 are blended in the parts by weight shown in Table 3. Adhesive 1 was prepared.
Adhesive 2: Adhesive 2 is prepared by blending 50 parts by mass of the acrylic adhesive agent A listed in Table 3 with the acrylic cross-linking agent B agent listed in Table 3 in the parts by mass listed in Table 3. bottom.

(5. Preparation of steel materials)
Steel material 1: A rectangular plate-shaped (150 mm x 70 mm x 3.2 mm) ordinary steel material (unpainted) was prepared, one main surface of which was blasted (Sa2.5: ISO 8501-1). The surface of the steel material 1 had a water contact angle of 75° measured according to the static drop method specified in JIS R3257:1999.
Steel material 2: Steel material 1 was prepared by forming an anticorrosion coating film on the surface thereof according to the following procedure. The surface of the steel material 1 was undercoated with an epoxy resin paint in a thickness of 120 μm after drying. Next, an intermediate coating for fluororesin coating (epoxy resin coating) was applied on the undercoat to a thickness of 30 μm after drying. Next, on the intermediate coating, a final coating was applied to a thickness of 25 μm after drying using a fluororesin coating material. The surface of the steel material 2 had a water contact angle of 85° measured according to the static drop method specified in JIS R3257:1999.
Steel material 3: Steel material 1 was prepared by forming an anticorrosive coating film on the surface thereof by the following procedure. The surface of the steel material 1 was coated with a fluororesin paint in a thickness of 25 μm after drying. The surface of the steel material 3 had a water contact angle of 80° measured according to the static drop method specified in JIS R3257:1999.

(6. Production of anti-corrosion sheet)
<Examples 1 to 29, Comparative Examples 1 to 2: Use of adhesive>
The main surface of the single-layer sheet and the two-layer sheet prepared in the molding example above (layer B for the two-layer sheet) on which the pressure-sensitive adhesive is applied was subjected to corona discharge treatment. Next, the adhesive is applied to a release paper (SLB-50BD manufactured by Sumika Kakoshi Co., Ltd.) so that the thickness is 50 μm, dried, and laminated by laminating on the main surfaces of the single-layer sheet and the double-layer sheet. Then, various anti-corrosion sheets having the laminated structures shown in Tables 4 and 5 were produced according to the test numbers.

(7. Combined cycle test (corrosion resistance test))
<Examples 1 to 29, Comparative Examples 1 to 2>
Various anti-corrosion sheets having an adhesive layer prepared by the above procedure were cut into a rectangular shape of 150 mm × 70 mm, the release paper was peeled off, and the adhesive layer side was attached to the blasted surface of the steel material 1. After that, it was aged for 2 days in an environment of 20° C. and 60% relative humidity. The pasting work was performed within 4 hours after the blasting treatment (Sa2.5: ISO 8501-1) on the steel material 1.

Next, using a combined cycle tester CYP-90 (manufactured by Suga Test Instruments Co., Ltd.), 200 cycles of the following steps (1) to (6) are performed on the steel material 1 to which the anticorrosion sheet is attached. A combined cycle test was conducted for accelerated corrosion of
(1) wet (95% RH, 30°C: 1 h) → (2) salt spray (5% NaCl, 30°C: 2 h) → (3) dry (20% RH, 50°C: 1.5 h) → (4) ) Wet (95% RH, 50° C.: 1.5 h) → (5) Dry (20% RH, 50° C.: 1.5 h) → (6) Dry (20% RH, 30° C.: 1.5 h) (however , (3) and (4) are alternately repeated six times during one cycle.)

After the combined cycle test, the appearance of the surface of the steel material to which the anticorrosion sheet was attached was visually checked to investigate the presence or absence of rust and the presence or absence of blistering of the anticorrosion sheet. A sample in which neither rust nor blistering was observed was evaluated as “abnormal”, and a sample in which at least one of rust and blistering was observed was evaluated as “abnormal”. In addition, for those with "abnormality", the ratio of the area where corrosion was confirmed to the surface of the steel material to which the anticorrosive sheet was attached was also obtained. The results are shown in Tables 4 and 5.

<Reference example 1>
The combined cycle test was carried out without attaching the anti-corrosion sheet to the steel material 1 . After that, the same appearance check as above was performed. Table 5 shows the results.

<Reference example 2>
Adhesive 1 was applied to the blasted surface of steel material 1 to a thickness of 0.5 mm after drying, and then aged for 2 days in an environment of 20° C. and 60% relative humidity. Note that the application work of the adhesive 1 was performed within 4 hours after the blasting treatment. Then, the composite cycle test was performed, and the appearance check was performed in the same manner as described above. Table 5 shows the results.

<Comparative Examples 3 to 8>
The main surface of the single-layer sheet and the two-layer sheet prepared in the above molding examples on the side to which the adhesive is applied (layer B in the case of the two-layer sheet) was subjected to corona discharge treatment. These single-layer sheets and double-layer sheets were then cut into rectangular shapes of 150 mm×70 mm. Then, an adhesive corresponding to the test number was applied to the blasted surface of the steel material 1 with a thickness of 25 μm after drying, and the main surfaces of the single-layer sheet and the two-layer sheet were laminated by bonding them together. It was cured for 2 days in an environment with a humidity of 60%. After that, the combined cycle test was performed, and the appearance check was performed in the same manner as described above. Table 5 shows the results.

(8. Adhesion test)
<Examples 1 to 29, Comparative Examples 1 to 2>
Various anti-corrosion sheets having an adhesive layer prepared by the above procedure are cut into a rectangular shape of 150 mm × 70 mm, the main surface opposite to the release paper is corona discharge treated, the release paper is peeled off, and the adhesive is applied. It was attached to the anti-corrosion coating film of the steel material 2 from the layer side. After that, it was aged for 2 days in an environment of 20° C. and 60% relative humidity.

Adhesion test (JIS K5600-5-7: 2014) was performed to measure the adhesion (breaking force) of the anticorrosion sheet to the anticorrosion coating film. In addition, after the above-described combined cycle test was performed on the steel material 2 to which the anticorrosive sheet was attached, the adhesive force test was performed in the same manner to measure the adhesive force (breaking force) of the anticorrosive sheet to the anticorrosive coating film. Tables 4 and 5 show the breaking strength before the combined cycle test as "before acceleration" and the breaking strength after the combined cycle test as "after acceleration".

<Reference example 1>
The adhesive force of the anticorrosion coating film was measured by the same method as above before and after the combined cycle test without attaching the anticorrosion sheet to the steel material 2 . Table 5 shows the results.

<Reference example 2>
After drying, the adhesive 1 was applied to the anticorrosion coating film of the steel material 2 to a thickness of 0.5 mm, and then cured for 2 days under an environment of 20° C. and a relative humidity of 60%. Next, the adhesion of Adhesive 1 to the anticorrosive coating before and after the combined cycle test was measured by the same method as above. Table 5 shows the results.

<Comparative Examples 3 to 8>
For the single-layer sheet and the two-layer sheet produced in the above molding examples, the main surface on which the adhesive is applied (layer B for the two-layer sheet) and the opposite side were subjected to corona discharge treatment. These single-layer sheets and double-layer sheets were then cut into rectangular shapes of 150 mm×70 mm. Then, after applying an adhesive to the anticorrosion coating film of the steel material 2 in a thickness of 25 μm after drying, the main surfaces of the single-layer sheet and the two-layer sheet are laminated by bonding them together, and the temperature is 20 ° C. and a relative humidity of 60%. It was cured in the environment for 2 days. Next, the adhesion of the anticorrosion sheet to the anticorrosion coating film before and after the combined cycle test was measured by the same method as above. Table 5 shows the results.

(9. Weather resistance test)
<Examples 1 to 29, Comparative Examples 1 to 2>
Various anti-corrosion sheets having an adhesive layer prepared by the above procedure were cut into a rectangular shape of 150 mm × 70 mm, the release paper was peeled off, and the anti-corrosion coating film of the steel material 3 was attached from the adhesive layer side. After that, it was aged for 2 days in an environment of 20° C. and 60% relative humidity.

The glossiness of the sheet surface of the steel material 3 to which the anticorrosive sheet was attached was measured using a 60° gloss meter, and the reference color was measured using a colorimetric color difference meter. Next, using a metal halide lamp type super accelerated weathering tester Eye Super UV Tester SUV-W161 (manufactured by Iwasaki Electric Co., Ltd.), UV irradiation intensity was 1,320 w/m ² , humidity was 50%, black panel temperature was 63°C, and UV irradiation was performed. Conditions: 3 cycles of 2 minutes shower, 8 minutes rest for 1 hour, 0.5 hour darkness without shower, total 1.5 hours as one cycle, test time 525 hours, attach anti-corrosion sheet. A weather resistance test was performed on the steel material 3. After the weather resistance test, the sheet surface of steel material 3 to which the anticorrosive sheet was attached was measured for gloss using a 60° gloss meter, and the color difference (ΔE ₅₂₅ ) was measured. Tables 4 and 5 show the gloss retention, which is the ratio of the glossiness after the weather resistance test to the glossiness before the weather resistance test. Tables 4 and 5 show the color difference retention after the weather resistance test compared to before the weather resistance test. Glossiness was determined by measuring 60° specular gloss according to JIS Z8741 using micro-glass 60° manufactured by BYK-Gardner. Color difference was determined by measuring spectral transmittance in accordance with JIS Z8722 using a colorimetric color difference meter (model: ZE6000) manufactured by Nippon Denshoku Industries Co., Ltd. The color difference retention rate was calculated using the following formula.
Color difference retention rate (%) = 100 - ΔE ₅₂₅

<Reference example 1>
The gloss retention rate and color difference retention rate of the anticorrosion coating film before and after the weather resistance test were measured in the same manner as described above without attaching the anticorrosion sheet to the steel material 3 . Table 5 shows the results.

<Reference example 2>
The adhesive 1 was applied to the anticorrosion coating film of the steel material 3 in a thickness of 25 μm after drying, and then cured for 2 days under an environment of 25° C. and 50% relative humidity. Next, the gloss retention and color difference retention of the adhesive surface before and after the weather resistance test were measured in the same manner as above. Table 5 shows the results.

<Comparative Examples 3 to 8>
The main surface of the single-layer sheet and the two-layer sheet prepared in the above molding examples on the side to which the adhesive is applied (layer B in the case of the two-layer sheet) was subjected to corona discharge treatment. These single-layer sheets and double-layer sheets were then cut into rectangular shapes of 150 mm×70 mm. Then, after applying an adhesive to the anticorrosion coating film of the steel material 3 with a thickness of 25 μm after drying, the main surfaces of the single-layer sheet and the two-layer sheet are laminated by bonding together, and the temperature is 25 ° C. and a relative humidity of 50%. It was cured in the environment for 2 days. Next, the gloss retention and color difference retention of the sheet surface before and after the weather resistance test were measured in the same manner as above. Table 5 shows the results.

(10. Workability)
<Examples 1 to 29, Comparative Examples 1 to 2>
Various anti-corrosion sheets 500 having adhesive layers prepared by the above procedure were cut into rectangular shapes of 820×120 mm. Then, as shown in FIG. 5, it was attached to the T-shaped steel material 200 so as to cover the member corner (edge surface) 212, and the time was measured. At this time, the anti-corrosion sheet with adhesive was applied after peeling off the release paper, and the anti-corrosion sheet using an adhesive was applied after applying the adhesive to the surface of the steel material. The average value of two tests was used as the measured value. In addition, the appearance of the anticorrosion sheet after construction was visually confirmed. The results are shown in Tables 4 and 5.

(11. Total light transmittance)
Using a haze meter NDH7000 (manufactured by Nippon Denshoku Industries Co., Ltd.), in accordance with JIS K7361-1-1997, all light rays of the single-layer sheet and double-layer sheet (molding examples 1 to 33) produced in the above molding examples Transmittance was determined. The results are shown in Tables 4 and 5.

(12. HAZE)
Using a haze meter NDH7000 (manufactured by Nippon Denshoku Industries Co., Ltd.), in accordance with JIS K7136-2000, measure the HAZE value of the single-layer sheet and double-layer sheet (molding examples 1 to 33) produced in the above molding examples. bottom. The results are shown in Tables 4 and 5.

<Discussion>
The steel coating laminates according to any of the examples were excellent in combined cycle test (corrosion resistance test), adhesion test, weather resistance test, workability, and transparency (total light transmittance, HAZE). On the other hand, the steel material coating laminate according to the comparative example did not have satisfactory properties in at least one of these properties. Detailed considerations are added below.

From Examples 1 and 5 and Comparative Examples 1 and 2 (2-1 to 2-5), in order to exhibit excellent corrosion resistance, weather resistance and workability, polyvinylidene fluoride resin and It can be seen that it is important to use one or both selected from the group consisting of ethylene-chlorotrifluoroethylene copolymers.

From Examples 2 to 4 and Comparative Example 1, it can be seen that even when polyvinylidene fluoride and poly(meth)acrylic acid ester resin are blended to form a fluorine-based resin layer, anticorrosion properties are exhibited. It is also found that blending polyvinylidene fluoride and poly(meth)acrylic acid ester resin improves the balance between weather resistance and adhesion.

From Examples 6 to 18, even if the compounding ratio of polyvinylidene fluoride and poly(meth)acrylic acid ester resin and resin compositions with different compounding compositions are laminated to form a fluorine resin layer, other physical properties It can be seen that corrosion resistance and weather resistance are exhibited without any influence. In addition, by increasing the blending ratio of polyvinylidene fluoride in layer A and increasing the blending ratio of poly(meth)acrylic acid ester resin in layer B, it can be seen that corrosion resistance and weather resistance are highly expressed. .

From Examples 7, 19 to 25, and Examples 5 and 26, by blending a UV absorber in the B layer, the color difference retention rate after the weather resistance test is improved without affecting other physical properties. I understand.

From Examples 7 and 24, it was confirmed that changing the UV absorber in the B layer did not affect the physical properties.

From Examples 7 and 25, it can be seen that the total light transmittance is maintained without impairing the physical properties other than the HAZE by applying embossing with an embossing roll during the production of the fluororesin layer. As a result, it was confirmed that the film can also be used as a matte film.

From Examples 2, 5, 7, and 27 to 29, it was confirmed that changing the pressure-sensitive adhesive layer did not affect the physical properties.

From Examples 2, 5, 7, 27 to 29 and Comparative Examples 3 to 8, it was found that the use of an adhesive prolongs the time required for attaching the steel material coating sample to the steel material, greatly reducing workability. confirmed.

It can be seen from Reference Examples 1 and 2 that it is important to use a fluororesin layer in order to develop corrosion resistance.

From Example 7 and Examples 30 to 34, it was confirmed that changing the thickness of the fluororesin layer did not affect the physical properties.

The steel material coating laminate according to the present invention can be applied to the surface of steel materials that constitute a steel structure that is installed in an exposed state to the outdoors, so that it can be used for repair work, reinforcement work, and post-construction work for aged-deteriorated structures. It can be widely used for maintenance and deterioration repair work. In addition, by attaching the laminate to a new structure or a structure that has not deteriorated over time, it can be widely used for preventive maintenance such as deterioration progress prevention work and deterioration progress prevention work. Further, in the embodiment in which the steel material covering laminate according to the present invention is transparent, deterioration of the steel material surface can be visually confirmed, so that it can be widely used for deterioration predictive maintenance work. In particular, when the steel material surface is painted, the degree of deterioration over time of the paint and the steel structure can be easily determined from the degree of fading of the paint.

REFERENCE SIGNS LIST 100 steel material covering laminate 110 fluorine-based resin layer 110a A layer 110b B layer 120 adhesive layer 130 separator 200 steel material 212 member corner (edge surface)
214 Ridge portions 215a, 215b Plane portion 216 Welded portion 217a, 217b Plane portion 300a, 300b Steel covering laminate 400a, 400b Steel covering laminate

Claims (22)

A laminate for covering a steel material provided with a fluororesin layer and an adhesive layer in this order containing one or both selected from the group consisting of a polyvinylidene fluoride resin and an ethylene-chlorotrifluoroethylene copolymer is installed outdoors. At least one portion selected from corners (edge surfaces), welds, ridges, and corners (vertex portions of polygons) of steel members that constitute a steel structure installed in an exposed state, A steel structure attached with an adhesive layer as an attachment side. A laminate for covering a steel material provided with a fluororesin layer and an adhesive layer in this order containing one or both selected from the group consisting of a polyvinylidene fluoride resin and an ethylene-chlorotrifluoroethylene copolymer is installed outdoors. A steel structure that is attached to the surface of a steel material that constitutes a steel structure that is installed in an exposed state, with the pressure-sensitive adhesive layer as the attachment side,
A steel structure, wherein the fluororesin layer is a laminate comprising at least the following A layer and B layer in this order, the B layer facing the pressure-sensitive adhesive layer.
Layer A: A resin composition containing 50 parts by mass to 100 parts by mass of a polyvinylidene fluoride resin and 0 parts by mass to 50 parts by mass of a poly(meth)acrylic acid ester resin (total of both is 100 parts by mass) A layer of things.
B layer: resin composition containing 0 parts by mass or more and less than 50 parts by mass of polyvinylidene fluoride resin and more than 50 parts by mass and 100 parts by mass or less of poly(meth)acrylic acid ester resin (total of both is 100 parts by mass) A layer of things. 3. The steel structure according to claim 1 or 2 , wherein the steel material coating laminate is used by being attached to the surface of the steel material to which paint is applied. 4. The steel structure according to claim 3 , wherein said paint contains one or more selected from the group consisting of fluorine resin paint, polyurethane resin paint and epoxy resin paint. 5. The steel structure according to claim 3 or 4 , wherein the surface of the steel material to which the paint is applied has a water contact angle of less than 90° measured according to the sessile drop method specified in JIS R3257:1999. The steel according to any one of claims 1 to 5 , wherein the steel coating laminate has a total light transmittance of 90% or more measured according to the measurement method specified in JIS K7361-1-1997. structure . The steel structure according to any one of claims 1 to 6 , wherein the steel covering laminate has a HAZE of 60% or less, measured according to the measuring method specified in JIS K7136-2000. The steel structure according to any one of claims 1 to 7 , wherein the adhesive layer contains a (meth)acrylic adhesive. The steel structure according to any one of claims 1 to 8 , wherein the steel coating laminate is for steel corrosion protection. 2. The steel structure according to claim 1 , wherein the fluororesin layer is a laminate comprising at least the following A layer and B layer in this order, with the B layer facing the pressure-sensitive adhesive layer.
Layer A: A resin composition containing 50 parts by mass to 100 parts by mass of a polyvinylidene fluoride resin and 0 parts by mass to 50 parts by mass of a poly(meth)acrylic acid ester resin (total of both is 100 parts by mass) A layer of things.
B layer: resin composition containing 0 parts by mass or more and less than 50 parts by mass of polyvinylidene fluoride resin and more than 50 parts by mass and 100 parts by mass or less of poly(meth)acrylic acid ester resin (total of both is 100 parts by mass) A layer of things. The steel structure according to claim 2 or 10 , wherein the total content of the polyvinylidene fluoride resin and the poly(meth)acrylic acid ester resin in the resin composition constituting the A layer is 80% by mass or more. 12. The steel structure according to claim 2, 10, or 11, wherein the total content of the polyvinylidene fluoride resin and the poly(meth)acrylic acid ester resin in the resin composition constituting the B layer is 80% by mass or more. . The resin composition constituting the B layer contains 0.05 to 15 parts by mass of an ultraviolet absorber with respect to a total of 100 parts by mass of polyvinylidene fluoride resin and poly(meth)acrylic acid ester resin. 13. The steel structure according to any one of items 2, 10 to 12 . The steel structure according to any one of claims 1 to 13 , wherein the adhesive layer is a two-component mixed adhesive. A laminate for covering steel materials, which is equipped with a fluororesin layer and an adhesive layer in this order containing one or both selected from the group consisting of a polyvinylidene fluoride resin and an ethylene-chlorotrifluoroethylene copolymer, outdoors. At least one portion selected from corners (edge surfaces), welds, ridges, and corners (vertex portions of polygons) of steel members that constitute a steel structure installed in an exposed state, A method for protecting or repairing a steel structure, comprising a step of attaching an adhesive layer to an attachment side. A laminate for covering steel materials, which is equipped with a fluororesin layer and an adhesive layer in this order containing one or both selected from the group consisting of a polyvinylidene fluoride resin and an ethylene-chlorotrifluoroethylene copolymer, outdoors. A method for protecting or repairing a steel structure, comprising a step of attaching the pressure-sensitive adhesive layer to the surface of a steel material that constitutes the steel structure installed in an exposed state, the adhesive layer being the attachment side,
A method for protecting or repairing a steel structure, wherein the fluororesin layer is a laminate comprising at least the following A layer and B layer in this order, with the B layer facing the adhesive layer.
Layer A: A resin composition containing 50 parts by mass to 100 parts by mass of a polyvinylidene fluoride resin and 0 parts by mass to 50 parts by mass of a poly(meth)acrylic acid ester resin (total of both is 100 parts by mass) A layer of things.
B layer: resin composition containing 0 parts by mass or more and less than 50 parts by mass of polyvinylidene fluoride resin and more than 50 parts by mass and 100 parts by mass or less of poly(meth)acrylic acid ester resin (total of both is 100 parts by mass) A layer of things. 17. A method for protecting or repairing a steel structure according to claim 15 or 16 , comprising the step 1 below.
Step 1: A step of attaching the steel material covering laminate to the member corners (edge surfaces) of the steel material constituting the steel structure. In step 1, by bending the steel covering laminate, the steel covering laminate is attached across at least a part of each of a pair of opposing flat surfaces adjacent to the member corners (edge surfaces). 18. A method of protecting or repairing a steel structure according to claim 17 , comprising: A method for protecting or repairing a steel structure according to any one of claims 15 to 18 , comprising a step 2 below.
Step 2: A step of attaching the steel material covering laminate to the welded portion of the steel material constituting the steel structure. Step 2 includes attaching the steel covering laminate across at least a part of each of the planar portions of the two members joined via the weld by bending the steel covering laminate. 20. A method for protecting or repairing a steel structure according to claim 19 . A method for protecting or repairing a steel structure according to any one of claims 17 to 20 , comprising a step 3 below.
Step 3: After step 1 or/and step 2, a step of attaching the steel material covering laminate to the plane portion of the steel material that constitutes the steel structure, wherein the attachment is performed in step 1 or/and step 2. a step of superimposing and sticking to the end portion of the steel material covering laminate. The method for protecting or repairing a steel structure according to any one of claims 15 to 21 , comprising a step of subjecting the surface of the steel material to keren treatment before the affixing step.

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