JPS6360712B2 - - Google Patents

Description

[Detailed description of the invention]

This invention combines polyolefin with a coloring pigment, a phenolic antioxidant, an ultraviolet absorber and/or a polyolefin.
Or it relates to a steel sheet pile having an anti-corrosion coating layer consisting of a colored plastic layer made of a specific polyolefin composition containing carbon black and an adhesive layer. Generally, steel sheet piles are driven underground and connected and used for seawalls in ports, rivers, etc.
Conventional corrosion protection for steel sheet piles does not have long-term corrosion protection or weather resistance (for about 20 years or more) in harsh natural environments where they are alternately exposed to waves, wind, snow, sunlight, etc., and their mechanical strength is poor. (particularly impact resistance, etc.) and were not sufficient. In addition, in places where the living environment and natural environment should be maintained comfortably and beautifully (for example, seaside new towns, seaside resort towns, national parks, quasi-national parks, seaside parks, and other natural parks), the living environment,
It was necessary to color the steel sheet piles to match the natural environment, but in the harsh natural environment mentioned above, simply coloring the steel sheet piles with paint would not work.
The coloring had been lost in a short period of several years, and no other suitable method of coloring steel sheet piles was known. Therefore, in general steel sheet piles, steel sheet piles that are colored and provided with a coating layer that has long-term corrosion resistance and weather resistance have not been used at all. As a result of extensive research into steel sheet piles that are colored in various colors and have a coating layer that has long-term corrosion resistance and weather resistance, the inventors found that polyolefins, coloring pigments, and phenolic antioxidants were used. The above-mentioned steel sheet pile is provided with an anti-corrosion coating layer consisting of a colored plastic layer and an adhesive layer formed from a specific polyolefin composition containing an ultraviolet absorber and/or carbon black. find satisfaction in purpose,
completed this invention. That is, in this invention, 100 parts by weight of polyolefin, 0.1 to 5 parts by weight of color pigment, 0.01 to 0.5 parts by weight of phenolic antioxidant, and 0.01 part by weight of ultraviolet absorber.
~0.5 parts by weight and/or carbon black
The present invention relates to a steel sheet pile with a colored coating layer, characterized in that a plastic layer made of a polyolefin composition containing 0.01 to 0.3 parts by weight is coated on the surface of the steel sheet pile via an adhesive layer. The steel sheet piles of this invention are colored in various colors (for example, green, blue, gray, red, white, etc.) and are made of a specific polyolefin that has excellent corrosion resistance, mechanical strength, durability, etc. for a long period of time. This is a new steel sheet pile that has a coating layer consisting of an adhesive layer and an adhesive layer, so it has a beautiful color that matches cities, natural parks, etc., and has excellent anticorrosion performance for a long time. . This invention will be explained in more detail below. In this invention, the polyolefin layer of the coating layer of the steel sheet pile contains (a) 0.1 to 5 parts by weight, preferably 0.5 to 4 parts by weight of a coloring pigment to 100 parts by weight of the polyolefin.
parts by weight, (b) 0.01 to 0.5 parts by weight of a phenolic antioxidant;
Preferably 0.05 to 0.4 parts by weight, (c) 0.01 to 0.5 parts by weight of ultraviolet absorber, preferably
From a polyolefin composition containing 0.05 to 0.4 parts by weight and/or (d) 0.01 to 0.3 parts by weight, preferably 0.02 to 0.25 parts by weight,
It can be formed using various methods. Examples of the polyolefin include high-density or low-density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, and ethylene-vinyl acetate copolymer.
Examples include propylene copolymers, and ethylene-based polymers are particularly preferred. The coloring pigment may be a coloring pigment containing any of known heat-resistant organic or inorganic pigment components, and may also be a mixture of several types of these pigment components or other additive components. In particular, the pigment used in the polyolefin composition of the present invention is a masterbatch type pigment in which the aforementioned pigment component is blended in the polyolefin resin in an amount of about 10 to 70% by weight, especially about 20 to 60% by weight. Suitable for preparing polyolefin compositions. Examples of the pigment components include white pigments such as titanium white (rutile type titanium,
Anatase type titanium, etc.), zinc white, lead white, lithopone For blue pigments, ultramarine (natural products, synthetic products),
Prussian blue (potassium ferrocyanide), copper phthalocyanine blue, phthalocyanine blue, phosto sky blue For green pigments, chromium oxide, chrome green (mixture of yellow lead and navy blue), zinc green (mixture of zinc yellow and navy blue) , chlorinated copper phthalocyanine green, phthalocyanine green For yellow pigments, yellow lead, zinc yellow, first yellow, Hansa yellow, auramine lake For red pigments, red lead, red iron oxide, basic lead chromate, vermilion, cadmium red, Examples include Paraled, Brilliant Carmine (condensed azo red), Brilliant Scarlet, Quinacridone Red, Lysol Red, and Vermilion. The above-mentioned coloring pigments are not suitable because if the addition ratio is too small, the color will not be vivid, and if the addition ratio is too large, the strength, weather resistance, etc. of the polyethylene layer of the coating layer will be reduced. It's not appropriate. Examples of the above-mentioned phenolic antioxidants include 4,4'-thiobis(3-methyl-t-butylphenol), tetrakis[methylene-3-
(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, stearin-β
(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 1,1,3-tris(2
-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,
4,6-tris(3,5-di-t-butyl-4-
hydroxybenzyl)benzene, octadecyl-
3-(3,5-di-t-butyl-4'-hydroxyphenyl)propionate, 2,6-di-t-butyl-p-cresol, 4,4'-butylidenebis(6-t-butyl-m -cresol). The above-mentioned phenolic antioxidant is particularly effective in improving weather resistance and heat resistance when blended into the polyolefin composition, and if the blending ratio is too small, the weather resistance will decrease, so it is not appropriate. If the blending ratio becomes too large, it bleeds out from the composition, and the addition of the excess amount becomes meaningless. Furthermore, the ultraviolet absorber may be any of various ultraviolet absorbers commonly used for polyolefins such as polyethylene and polypropylene, such as benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, and phenyl salicylate ultraviolet absorbers. Examples include ultraviolet absorbers, aromatic amine ultraviolet absorbers, and phenyl sulfide ultraviolet absorbers. In particular, in this invention, benzotriazole ultraviolet absorbers, aromatic amine ultraviolet absorbers, Optimal in terms of weather resistance when used with color pigments. As the benzotriazole ultraviolet absorber, for example, 2(2'-hydroxy-3',5'-di-t
-butylphenyl) 5-chlorobenzotriazole, 2(2'-hydroxy-5'-methylphenyl)
Benzotriazole, 2(2'-hydroxy-3'-
t-Butyl-5'-methylphenyl)benzotriazole, 2(2'-hydroxy-3'-t-butyl-
Examples of aromatic amine ultraviolet absorbers include bis(2,2,6,
Examples include 6-tetramethyl-4-pideridine) sebacate, [2-2'-thiobis(4-t-octylphenolate)]-n-butylamine nickel, and benzophenone ultraviolet absorbers include 2 Examples include '-hydroxy-4-n-octyloxybenzophenone and 4-dodecyloxy-2-hydroxy-benzophenone. In this invention, the above-mentioned ultraviolet absorber is especially blended into the polyolefin composition and is effective for long-term weather resistance, and if the blending ratio is too small, the weather resistance will be significantly reduced, so it is not suitable. Moreover, if the blending ratio becomes too large, it bleeds out from the composition, and the addition of the excess amount becomes meaningless. In this invention, it is optimal for the polyolefin composition to contain a coloring pigment, an antioxidant, an ultraviolet absorber, and carbon black from the viewpoint of long-term weather resistance of the plastic layer. . In addition, in the above polyolefin composition,
If the blending ratio of carbon black exceeds 0.3 parts by weight, the coloring effect of the coloring pigment will be lost, resulting in a dark black color, which is not suitable. In this invention, the polyolefin composition is
In addition to the above-mentioned components, other polymers, known plasticizers, flame retardants, various coloring aids, fillers, etc. may be blended. The above polyolefin composition is coated on the surface of a steel sheet pile as the outermost plastic layer of the coating layer, and the tensile strength of the plastic layer is 50 to 300 Kg/cm ² as measured by ASTM G14. Impact resistance (per 1 mm thickness) is 10 to 200 kg.
cm. Therefore, it is preferable to prepare a polyolefin composition by appropriately selecting the above-mentioned polyolefin resin and various other compounding agents so as to obtain a plastic layer with such performance. In this invention, the adhesive layer is heated to about 50-200°C.
Any type of adhesive may be used as long as it has a bonding temperature within the range of A heat-fusible adhesive (such as a hot melt type adhesive) containing an olefin-based (co)polymer as a main component, or the above-mentioned (co)polymer and a tackifier as a main component, or It is a thermosetting adhesive, etc. that maintains appropriate elasticity or flexibility after bonding and does not become too hard or brittle. Adhesive strength to steel plate surface (180 degree peeling, tensile speed 10
mm/min, 20℃) is about 2Kg/cm or more, especially 4 to 20
It is preferable that the adhesive is made of an adhesive having a tensile strength of approximately Kg/cm. Examples of olefinic (co)polymers used in such adhesives include polyethylene, polypropylene, polyvinyl chloride, ethylene/vinyl acetate copolymer, ethylene/propylene copolymer,
Examples include ethylene/lower alkyl (meth)acrylate copolymers, ethylene/(meth)acrylic acid copolymers, and modified polymers thereof (e.g., maleated polyethylene, maleated polypropylene, etc.), which may be used alone. Alternatively, it may be used as a mixture of two or more types. The tackifier can be arbitrarily selected from tackifiers commonly used in known adhesive compositions, and examples of the tackifier include rosin and rosin derivatives, Examples include pinene resin, coumaron resin, coumaron-indene resin, other aliphatic hydrocarbon resins, aromatic hydrocarbon resins, and alicyclic hydrocarbon resins. In this invention, the adhesive layer contains, in addition to the above-mentioned components, an inorganic filler such as talc, charcoal, silica, alumina, mica, and carbon black, or an antioxidant, a coloring agent, and a softening agent. Additives, as well as corrosion inhibitors, such as metal chromates, metal phosphates, metal phosphites,
Inorganic corrosion inhibitors such as metal nitrites, metal salts of aromatic carboxylic acids, aliphatic or aromatic compounds having multiple hydroxyl groups, and organic corrosion inhibitors such as tannic acid may be added. . In addition, in the present invention, the steel sheet pile having an adhesive layer has its surface subjected to some kind of treatment in advance before forming the adhesive layer on its surface to improve its resistance to corrosion. It may be something that has been done. In addition, if steel sheet piles have had their surface mill scale, red rust, dirt, etc. removed by shot blasting, sandblasting, pickling, etc. prior to being coated with adhesive, the plastic layer will not adhere to the adhesive. This is preferable because it increases the bonding force to the steel sheet pile through the layers. In addition, prior to coating the surface of the steel sheet pile with the adhesive layer, the surface of the steel sheet pile is subjected to chromic acid treatment, phosphoric acid treatment, and/or
Alternatively, if an epoxy resin primer is applied, the adhesion and corrosion protection will be even better. In this invention, the steel sheet pile to be covered with the plastic layer preferably has an adhesive layer on the surface to be coated, and the adhesive layer is formed on the steel sheet pile in advance by a known method. Alternatively, a softened adhesive layer may be formed by extruding an adhesive onto the surface of the steel sheet pile to be coated almost simultaneously with or immediately before coating with the plastic layer described above. good. In this invention, the coating layer of the steel sheet pile has a plastic layer thickness of about 0.4 to 5.0 mm, although the overall thickness and the thickness of each layer are not particularly limited.
The thickness of the adhesive layer is about 0.05 to 2.0
mm, and the thickness ratio of the plastic layer to the adhesive layer is preferably 1:2 to 100:1,
Furthermore, the thickness of the entire coating layer is approximately 0.5 to 60 mm,
In particular, it is preferably about 1.0 to 3.5 mm. The anti-corrosion coated steel sheet pile of the present invention can be manufactured by various methods, for example, by forming a plastic sheet from the above-mentioned polyolefin composition and, if necessary, crosslinking the sheet with an electron beam. A method of heat-bonding the sheet to the surface of a steel sheet pile having an adhesive layer in a heated state, or a method of continuously extruding the above-mentioned polyolefin composition from an extrusion molding machine to continuously supply a steel sheet pile having an adhesive layer. It can be manufactured by heating and bonding along the surface of the steel sheet pile and continuously forming a coating layer on the surface of the steel sheet pile. The colored anti-corrosion coated steel sheet pile of this invention is
A plastic layer made from a specific polyolefin composition is bonded to the inner or outer surface of a steel sheet pile for civil engineering and construction via a heat-adhesive adhesive layer to form an anticorrosive coating layer. In addition to having a beautiful color that matches the natural environment, it also has extremely excellent impact resistance.
It also has weather resistance and durability against the natural environment, and when steel sheet piles are driven into the ground, underground stones and
It can sufficiently resist the impact caused by strong contact with gravel, gravel, etc., or the impact and erosive force caused by being struck by river water, seawater, or even drifting objects, and furthermore,
The plastic layer and the adhesive layer are in close contact with and protect the surface of the steel sheet pile, and the surface of the steel sheet pile is not brought into direct contact with or exposed to water, air, or sunlight. , for a long period of time (e.g., about
It shows a high level of corrosion protection performance for more than 20 years, especially for about 30 years. Examples and comparative examples of the present invention will be shown below. Examples 1 to 10 Low density polyethylene (density; 0.925, MI; 5.0
A pigment masterbatch was used in which 6 parts by weight of 6 parts by weight of the pigment components listed in Table 1 (the amounts of each component used were approximately equal) were blended, and the antioxidant a) Tetrakis [Methylin-3]. -(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane and UV absorber b) 2(2'-hydroxy-3',5'-di-t-butylphenyl)-
5-chlorobenzotriazole, low density polyethylene (density: 0.925, MI: 0.3g/10
The polyolefin compositions shown in Table 1 were prepared by blending these additives into the polyolefin composition shown in Table 1.

[Table] Each of the polyolefin compositions described above was formed into a sheet (thickness: 0.8 mm), which was heat-bonded at about 135°C to a U-shaped steel sheet pile having an adhesive layer with the composition shown below. A steel sheet pile having a coating layer consisting of a gas layer and an adhesive layer was manufactured. Adhesive composition Ethylene/α-olefin copolymer (MI: 3.2
g/10 minutes, density: 0.88 g/cm ³ ) 17 parts ethylene/vinyl acetate copolymer (melting point: 95°C, softening point: 78°C) 20 parts styrene/butadiene/styrene block copolymer (density: 0.94 g / ^cm3 ) 17 parts Coumarone resin (softening point: 93℃) 17 parts terpene/phenol copolymer (softening point: 100℃)
20 parts Hydrogenated rosin ester (softening point: 68°C) 9 parts The bonding temperature of this adhesive is approximately 130°C. Table 2 shows the results of a weather resistance test performed on the plastic layer of the anti-corrosion coated steel sheet pile obtained by these coatings.

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【table】

Claims (1)

[Claims] 1 100 parts by weight of polyolefin, 0.1 to 0.1 to 100 parts by weight of color pigment
5 parts by weight, phenolic antioxidant 0.01-0.5
parts by weight, ultraviolet absorber 0.01-0.5 parts by weight and/or
Or steel with a colored coating layer, characterized in that a plastic layer made of a polyolefin composition containing 0.01 to 0.3 parts by weight of carbon black is coated on the surface of the steel sheet pile via an adhesive layer. Sheet pile.