JP2963466B2 - Method for producing fluororesin film-coated cement molding and member for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is excellent in weather resistance, air pollution resistance and chemical resistance,
In particular, the present invention relates to a method for producing a fluororesin film-coated cement molded product suitable for a wide range of applications requiring durability outdoors and indoors, and a member for producing the same.

[Prior Art] Conventionally, a cement molding (hereinafter, concrete structure and cement product are collectively referred to as cement molding)
Is widely used in large quantities as it is durable and durable for long-term use, and is also used as social capital and public goods such as roads, bridges, railways and buildings. It has become very important.

However, these cement moldings, which were considered to be able to withstand long-term use, began to deteriorate and age due to various factors after the start of use, making them unsuitable for long-term use. Limits are emerging. The causes of such deterioration and aging are concrete neutralization, penetration of chloride ions, freezing damage, delamination and destruction of concrete due to alkali-aggregate reaction, and rusting and breakage of reinforcing steel. It is recognized as. The main cause of these factors, and the most problematic, is that substances such as carbon dioxide, chlorine and oxygen supplied from outside the concrete penetrate into the concrete, Reinforcement or rupture of the reinforcing bar may be mentioned. Therefore, in order to use a cement molded product that can withstand long-term use, it is necessary to prevent the penetration of these substances such as carbon dioxide, chlorine, and oxygen.

[Problems to be Solved by the Invention] In general, as a method for preventing the above-mentioned substances such as carbon dioxide, chlorine, and oxygen from penetrating into the concrete, coating methods such as coating film and coating film waterproofing have been adopted because of simplicity of operation. Is applied. However, in coating, the surface of the cement molded product is not necessarily smooth, so that a pinhole or the like is formed in the coating film, and since the film thickness of the coating film is non-uniform, the harmful substances as described above are used. The effect of preventing penetration may be insufficient. Further, since the film thickness is not uniform, it is impossible to follow the deformation of the cement molded product, so that local cracking or peeling may occur. In particular, the performance of the object to be coated greatly depends on the difference in the coating technique of the worker.

In addition, general coating materials such as vinyl chloride resin and epoxy resin have poor long-term durability in the harsh environment (sunlight, seawater, freezing, dust, etc.) where cement moldings are placed. It is unsuitable as a coating material for a cement molded product that is desired to withstand use. In particular, development of a weather-resistant cement molded product for an outer wall is desired.

SUMMARY OF THE INVENTION The present invention has been made in order to improve such conventional drawbacks, and provides a method for producing a fluororesin-based film-coated cement molding having excellent weather resistance, air pollution resistance, and chemical resistance. It is intended for.

Means for Solving the Problems In view of the above problems, the present inventors maintain and maintain a cement molded product at a high level, and furthermore, have a longer life and a longer service life than before. As a result of intensive studies, cement molding was achieved by coating and protecting a cement molded product with a film composed mainly of fluororesin as a main component, which has excellent weather resistance, air pollution resistance, and chemical resistance. They found that the durability of the product could be improved, and completed the present invention.

That is, in the present invention, the outer frame is temporarily fixed such that the film surface is in contact with the laminate composed of the anchor layer, the reinforcing base material layer, and the film mainly composed of the fluororesin, and then the laminate is temporarily fixed. After assembling a casting mold having an anchor layer on the inner surface using at least one outer frame, a kneaded material of a cement molding is poured into the casting mold, and after curing, the outer frame is removed and laminated with the cement molding. A method for producing a fluororesin-based film-coated cement molded product, which comprises integrally forming a body.

Further, the present invention is characterized in that a laminate comprising an anchor layer, a reinforcing base material layer and a film containing a fluorine-based resin as main components is temporarily fixed to an outer frame so that the film surfaces are in contact with each other. This is a member for producing a system film-coated cement molded product.

 Hereinafter, the present invention will be described in detail.

The present invention is characterized in that a fluororesin film excellent in weather resistance, air pollution resistance and chemical resistance is used as a surface layer, and a cement molded product is covered and protected by the fluororesin film. However, as a fluororesin film, the fluororesin is 50% by weight or more, preferably 60% by weight.
What contains the above is used. If the amount is less than 50% by weight, effects such as weather resistance, air pollution resistance and chemical resistance of the cement molded product cannot be sufficiently obtained. Examples of the fluororesin used include homopolymers and copolymers of vinylidene fluoride (PVDF), tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, and vinyl fluoride. Examples of the copolymer include vinylidene fluoride and tetrafluoroethylene copolymer, vinylidene fluoride and hexafluoropropylene copolymer, copolymer of ethylene and tetrafluoroethylene, and copolymer of tetrafluoroethylene and hexafluoropropylene. And the like.

For the purpose of imparting other properties such as adhesiveness, a resin compatible with the fluorine-based resin can be used as the fluorine-based resin. For example, a resin compatible with vinylidene fluoride includes a methacrylate ester-based resin.
The methacrylate-based resin refers to a homopolymer of methyl methacrylate (MMA), a copolymer of a monomer copolymerizable with methyl methacrylate, and a blend of polymethyl methacrylate and an acrylic rubber. Examples of the copolymerizable monomer include methacrylic acid esters having 2 to 4 carbon atoms, acrylates having 1 to 8 carbon atoms including butyl acrylate, styrene, α-methylstyrene, acrylonitrile, acrylic acid, and others. And ethylenically unsaturated monomers. The content of the above resin other than the fluororesin contained in the fluororesin film is 50% by weight or less based on the total amount of the resin used. Preferred examples of the fluororesin-based film include a composition containing 100 to 50% by weight of vinylidene fluoride and 0 to 50% by weight of methyl methacrylate as main components.

Further, a pigment, an ultraviolet absorber, a stabilizer, a filler, a processing aid, and the like can be added to the fluororesin film as needed.

As the pigment that can be used for the fluororesin film, any of an inorganic pigment and an organic pigment may be used.
As the inorganic pigment, for example, a composite oxide-based inorganic pigment, which is said to form a new crystal structure by firing two or more metal oxides and develop color by crystal field splitting, can be used as a main colored pigment. The main composite oxide-based inorganic pigments are Ti
Rutile-type or briderite-type titanium-yellow-based crystals containing O ₂ · Sb ₂ O ₃ · BaO · NiO · Cr ₂ O ₃ as main components, ZnO · Fe ₂ O ₃ ·
Zinc spinel crystals mainly composed of Cr ₂ O ₃ - iron brown, cobalt blue-based spinel crystals mainly composed of _{CoO · Al 2 O 3 · Cr} 2 O 3, TiO 2 · CoO · NiO · Green based on ZnO, black based spinel based on CuO ・ Cr ₂ O ₃ and CuO ・ Fe ₂ O ₃・ Mn ₂ O ₃ , violet based on CuO and Mn ₂ O ₃ etc. is there. Rutile-type titanium oxide, zinc white, calcium carbonate, barium sulfate and other inorganic pigments can be used together with these colored pigments.

In addition, examples of the organic pigment include the following pigments.

○ Monoazo pigments Azo lake type Lake red C Watchchan red Priantian carmine 6B Benzimidazolone type PV orange HL ○ Disazo pigment diallylide yellow type Permanent yellow HR Pyrazolone type Benzidine red ○ Condensed azo pigment Condensed azo type Condensed azo yellow Condensed azo red ○ Polycyclic pigments Quinacridone quinacridone red Dioxazine dioxazine violet Isoindolinone yellow 3RLT Bat perylene red Perinone orange Induthrone blue Phthalocyanine phthalocyanine blue Phthalocyanine green The amount of pigment added to the resin used for the fluororesin film is as follows: 0 to 100, preferably 1 to 100 parts by weight of the resin
50 parts by weight. If it exceeds 100 parts by weight, the film strength will be reduced. Further, in order to protect the reinforcing base material layer used for reinforcing the fluororesin-based film, it is preferable to add a pigment so as to have an impure force.

The ultraviolet absorber may be any one that is compatible with the resin used for the fluororesin film, and a high molecular weight ultraviolet absorber is preferable to prevent volatilization.
Examples of the ultraviolet absorber include benzotriazole-based, oxalic acid-based, benzophenone-based, hindered amine-based, and many other types of known ones. More specifically, 2- (3,5-di-allophordimethylbenzyl-2-hydroxyphenyl) benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) benzotriazole, -(3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-butyl-2)
-Hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole, 2-ethoxy-2'-ethyloxac acid bisanilide, 2-ethoxy- 5
-T-butyl-2'-ethyloxacacid bisanilide, 2-hydroxy-4-n-octoxybenzophenone, bis (1,2,2,6,6-pentimethyl-4-piperidyl) sebacate, bis (1 , 2,2,6,6-tetramethyl-4-piperidyl) sebacate, dimethyl-2- (4-
Hydroxy-2,2,6,6-tetramethyl-1-piperidyl) ethanol, 1- [2-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy]-
2,2,6,6-T-tetramethylpiperidine and the like. The amount of the ultraviolet absorber added is 0.1 to 15 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the resin. If the addition amount is less than 0.1 part by weight, the ultraviolet absorption amount is small, so that the performance as UV protection becomes insufficient.

The thickness of the fluororesin-based film is in the range of 0.1 to 500 μm, preferably 1 to 200 μm, for the purpose of imparting weather resistance of the intended cement molded product and preventing penetration of harmful substances from the atmosphere and the outside. . The fluororesin-based film may be a single layer or a laminate of two or more layers. For example, a laminate of two layers of films having different fluorine resin contents may be used.

Examples of the cement molded product covered and protected by the fluororesin film include concrete structures and cement products. For example, outdoor and indoor materials such as outer wall materials (curtain walls), roof materials, and inner wall materials. And cement moldings widely used regardless of the type. In particular, the above-mentioned fluororesin-based film is suitable for protecting a cement molded product which is exposed outdoors and is easily deteriorated.

Next, as a reinforcing substrate layer of the fluororesin film used in the present invention (hereinafter, referred to as a substrate layer),
(1) Films, sheets and plate-like materials mainly composed of thermoplastic resin and thermosetting resin, (2) metal plate, (3)
Rubber products, (4) nonwoven fabrics, woven fabrics and tents.

As the thermoplastic resin, a general thermoplastic resin is used. For example, methacrylate resin, polycarbonate, vinyl chloride (hard or soft), ABS resin, polyethylene, polypropylene, polyvinyl chloride-vinyl acetate copolymer, polystyrene, Impact polystyrene, polyamide, polyacetal, polycarbonate, polycarbonate-ABS
Resins such as alloy, polycarbonate-AES alloy, modified PPE, polyester, polyvinylidene chloride, polyvinyl alcohol, AES, AAS, phenylmaleimide ABS, polyphenylene sulfide, polyarylate, polyether sulfone, polyimide, and polysulfone are used.

As the thermosetting resin, a general thermosetting resin is used, for example, phenol resin, furan resin, xylene resin, formaldehyde and ketone resin, melamine resin, aniline resin, sulfonamide resin, aluminide resin, unsaturated polyester resin, Epoxy resins and the like can be mentioned.

Furthermore, in consideration of the adhesiveness with the fluororesin film among the thermoplastic resins forming the base material layer, a mixture of a methacrylate ester resin and a methacrylate ester resin and a vinylidene fluoride resin is preferable, and Preferably, a composition mainly containing 100 to 50% by weight of methyl methacrylate and 0 to 50% by weight of vinylidene fluoride is preferred.

These thermoplastic resins and thermosetting resins are the above-mentioned pigments and ultraviolet absorbers and other stabilizers, fillers, processing aids,
Glass fibers, carbon fibers, potassium titanate fibers and the like can be used in combination.

Further, foamed films, sheets and plate-like materials can also be used as the thermoplastic resin molded products.

Examples of the metal plate include a steel plate, a zinc-treated steel plate, a tin plate, a stainless steel plate, an aluminum plate, and an aluminum foil. For bonding the fluororesin film and the metal plate, a general adhesive such as an epoxy resin, an acrylic resin, or a urethane resin can be used.

As the rubber molded product, general synthetic rubber and natural rubber molded products are used. For example, SBR, NBR, butyl rubber, chloroprene rubber, acrylic rubber, urethane rubber,
Molded products such as isoprene rubber are exemplified.

Nonwoven fabrics, woven fabrics and tents are used as they are laminated on a fluororesin film, but may be used as a composite of these and a thermoplastic resin.

The base material layer only needs to be able to reinforce the fluororesin film, and its thickness is not particularly limited, but is naturally limited in terms of workability and economy. Generally 0.005mm ~ 2
0 mm, preferably 0.01 mm to 10 mm. Further, the base material layer may be composed of a laminate composed of two or more different resin compositions.

Next, in the present invention, an anchor layer is used,
The anchor layer is used for fixing the base material layer and the fluororesin-based film to the cement molding without using an adhesive. The anchor layer is formed in a spot-like or continuous form on the back surface layer of the base material layer, and is suitable for a method of manufacturing a resin-coated cement molded product of the present invention by driving a kneaded cement molded product described below.

Components forming the anchor layer include thermoplastic resin molded products, metal molded products, and fibrous materials.

The shape of the anchor layer is not particularly limited as long as the substrate layer and the cement molded product are firmly fixed, and the shape is not particularly limited, and examples thereof include a columnar shape, a plate shape, and a net shape. An example of the specific shape is shown in FIGS.

The thickness of the anchor layer is not particularly limited, but is usually 1
Those having a range of 100100 mm, preferably 5-30 mm are used. The bonding between the anchor layer and the base layer is usually performed by using an adhesive or by thermal bonding. However, the base layer and the anchor layer may be integrally formed at the same time. As the mesh, for example, a high-density polyethylene net is used.

In the present invention, a protective layer is used to protect the fluororesin-based film from damage such as scratches during the production and transportation of the resin-coated cement molding. The protective layer is provided on the fluororesin-based film, and the protective layer is formed by adding an adhesive to one or both sides of a generally used thermoplastic resin film, and the thermoplastic resin film itself. Those having adhesive strength can be used without an adhesive. Examples of the thermoplastic resin film include a polyethylene film, a polypropylene film, a polyester film, a polycarbonate film, a polyvinyl alcohol film, an ethylene vinyl alcohol copolymer film, a nylon film, a vinylidene chloride film, a vinyl chloride film, cellophane, an acrylonitrile-based film, and the like. Can be

Next, a method for producing a fluororesin film will be described. The fluororesin-based film in the present invention is composed of one or two or more layers, and there is no particular limitation on the production method, but generally, a method carried out by melt extrusion molding is used. In addition to a single screw extruder generally used for melt extrusion, a twin screw extruder is also used. In the case of a structure having two or more layers, a co-extrusion method in which a plurality of layers are integrally bonded is used. It is preferred to employ

A multi-manifold die is used in a co-extrusion molding method using a T-die in which a resin is bonded in a molten state by using a plurality of extruders to form a multilayer. There is a method in which the resin is eroded and bonded, and a method in which a plurality of resins are bonded and then spread in a film shape. Also, a multilayer film can be formed by a method using a round die, which is called an inflation molding method.

In addition, there is no particular limitation on the method of mixing additives such as an inorganic pigment and an ultraviolet absorber in the resin components of the fluororesin film and the base material layer.For example, the resin and the additives are mixed in advance, A method of melt kneading using a generally used single screw extruder may be used.

The base material layer is composed of one or more layers, and the production method is not particularly limited, but the same method as that for the fluororesin film is used.

The method for producing a laminate of a fluororesin film and a substrate layer may be such that the fluororesin film and the substrate layer are separately produced and integrated by thermocompression bonding or the like. And the base material layer can be simultaneously co-extruded.

Further, as a method of saving labor in a method of manufacturing a laminate of the anchor layer, the base material layer and the fluororesin film, a method of simultaneously forming the fluororesin film, the base material layer and the anchor layer is also used.

Next, a method for producing the resin-coated cement molded product of the present invention will be described. The cement molded product used in the present invention includes concrete structures and cement products as described above. Among them, Portland cement, alumina cement, mixed cement and other hardened cement bodies, as well as high-temperature It also includes a cured product of calcium silicate obtained by high-pressure treatment.

The method for producing a resin-coated cement molded product of the present invention is that, before the casting, a fluororesin-based coating material is installed inside the mold beforehand, and a kneaded product of the cement molded product is cast and cured. A method of installing the fluororesin-based coating material on the surface of a cement molded product by removing a mold
This is referred to as a pre-installation method. In addition, a fluororesin-based coating material represents a fluororesin-based film / substrate layer / anchor layer.

Next, in the pre-installation method, a fluororesin-based coating material is temporarily fixed in advance to the inside of a casting mold, a kneaded material of a cement molded product is cast and cured, and the fluororesin-based coating material is cured on the surface of the cement molded product. Specifically, an outer frame in which an anchor layer, a base material layer and a laminate made of a fluororesin film are temporarily fixed to the outer frame so that the film surfaces thereof are in contact with each other, and then the outer frame is temporarily fixed to the laminate After assembling a casting mold having an anchor layer on the inner surface using at least one surface, a kneaded material of a cement molding is poured into the casting mold, and after curing, the outer frame is removed to remove the cement molding and the laminate. This is a method of integrally forming. This method is more advantageous in terms of process than the retrofitting method for work on site.

As a method of temporarily fixing the fluororesin-based coating material to the casting mold, it is preferable to use an easily peelable adhesive or a double-sided tape, since it is necessary to peel off the cement molding from the casting mold later. Easy-to-peel adhesives and double-sided tapes consist of glucose-based polymers (starch,
Dextrin), polymer latex (polyvinyl chloride, ethylene-vinyl acetate copolymer, polyvinyl-vinyl acetate copolymer, etc.), water-soluble polymer (poval, methylcellulose, etc.), and the like. However, the present invention is not limited to this. Also, among the adhesives containing these as main components, those having strong adhesive strength are not preferable. In any case, it is important to use a material that can be easily removed later.

Next, by kneading the kneaded material of the cement molded product into a casting mold where the fluororesin-based coating material is temporarily fixed, the fluororesin-based coating material is placed on the surface of the cement molded product. The installation method in this case is performed by a method of providing an anchor layer on a fluororesin-based coating material.

The anchor layer physically adheres the fluororesin-based coating material and the cement molded product, and there is no limitation on the shape, size, material, and the like. Examples include, as described above, a resin-based or metal-based projection bonded to the back surface of a fluororesin-based coating, a resin-based projection welded, or integrally molded with a fluororesin-based coating. There are things.

Next, FIG. 4 shows an example of a member for producing a resin-coated cement molding used in the pre-fixing method using an anchor layer. In the member shown in FIG. 1, a laminate composed of the anchor layer 3, the base layer 2, the fluororesin film 1, and the protective layer 4 is attached to the outer frame 9 such that the fluororesin film surface is in contact with the outer layer 9 via the protective layer 4. Is temporarily fixed at the position. A member comprising an outer frame to which the laminate is temporarily fixed is used on at least one surface of the casting form, and is assembled so as to have an anchor layer on the inner surface of the casting form, and then cement-molded into the casting form. A kneaded material is driven in and a pre-receiving method is performed. After the cement molding has hardened, the outer frame 9 is removed together with the protective layer 4.

According to the above-mentioned construction method (pre-installation construction method), the cement molding and the fluororesin-based coating material are combined at the construction site, but during the work, the fluorine-resin-based film is prevented from being damaged. It is preferable to use a protective film as a protective layer on the surface of the resin-based film. This protective layer prevents adhesion of the temporary fixing adhesive in the case of the pre-applying method. Furthermore, in the case of the pre-installation method, when the peeling surface with the casting mold is provided between the protective layer and the fluororesin-based coating material when the cement molded product is released from the mold, the peeling can be performed relatively easily, and the fluorine can be removed. There is an advantage that the surface of the resin film can be kept in a good state. After the combination work, the protective layer can be peeled off.

[Example] Hereinafter, the present invention will be described more specifically with reference to examples.

Reference Example 1 and Comparative Examples 1 and 2 Using a concrete having a nominal strength of 270 kg / cm ² and a slump of 15 cm, a neutralization promotion test of carbon dioxide in the cement molded product of the present invention was performed. The basic mix of concrete is as shown in Table 1 below.

Using this concrete, a cylindrical test specimen with a diameter of 10 cm and a height of 20 cm was created.
It was left in a constant humidity and humidity curing room of% RH. On the 7th day of the material age, the mold was removed, and divided into Reference Example 1 and Comparative Example 1.2, each of which was treated. That is, in Reference Example 1, after performing a degreasing treatment on a concrete cylindrical specimen, a fluororesin-based coating material was carefully adhered to the entire surface along the circumferential direction using an epoxy resin for adhesion (KONISHI BOND E206). . In addition,
The fluororesin coating used was vinylidene fluoride resin.
A pellet-like melt consisting of 90 parts by weight, 10 parts by weight of methyl methacrylate resin and 5 parts by weight of titanium oxide as a pigment was subjected to 50 μm by using a film production facility equipped with a T-die.
A film formed to a thickness of m was used.

Further, as Comparative Example 1, after a cylinder specimen was degreased, a commercially available anticorrosive epoxy resin-based paint was carefully brushed over the entire surface along the circumferential direction. Further, an untreated cylindrical specimen was also tested as Comparative Example 2.

These cylindrical specimens were cured in a constant temperature and humidity room at 20 ° C. and 80% RH until the age of 28 days. On the 28th day of material age, these cylindrical specimens were allowed to stand in a pressure vessel, and using a vacuum pump,
After degassing at 10 mmHg or less for 15 minutes, inject carbon dioxide,
It was pressurized at a pressure of 3 kg / cm ² for 4 hours. Thereafter, the cylindrical test body was taken out, split into two by splitting, and a phenolphthalein solution was sprayed on the split fracture surface. Assuming that the portion that did not turn red by phenolphthalein was neutralized, that is, it was affected by carbon dioxide, the depth to that position was measured using calipers. The results are shown in Table 2 below. In the test specimen left outdoors for 2 years, neutralization was not observed in this reference example, but neutralization was slightly observed in the comparative example. The color difference of the fluororesin film was 1.6, and there was little discoloration from the start of the test, and the weather resistance was good.

Reference Example 2 In Reference Example 1, 80 parts by weight of vinylidene fluoride resin, 20 parts by weight of methyl methacrylate resin, and TiO ₂ as a pigment were used for a fluororesin film of a fluororesin coating material.
A pellet-like melt composed of 5 parts by weight of a green pigment containing CoO, NiO and ZnO as main components, and 80 parts by weight of a methyl methacrylate resin and 20 parts of a vinylidene fluoride resin as a base material layer;
A 20 μm fluororesin film produced by a co-extrusion molding method using a pellet-like melt consisting of 5 parts by weight of a green pigment mainly composed of TiO ₂ , CoO, NiO, ZnO as a pigment and a 60 μm base The same procedure was performed except that a two-layer film composed of material layers was used.

Neutralization was not observed in the specimen left outdoors for 2 years, the color difference on the surface was 1.4, and the weather resistance was good.

Example 1 A test for promoting neutralization with carbon dioxide was performed using concrete having a nominal strength of 210 kg / cm ² and a slump of 20 cm. The basic mix of concrete is as shown in Table 3 below.

Using this concrete, a cylindrical test specimen with a diameter of 10 cm and a height of 20 cm was created.
It was left in a constant humidity and humidity curing room of% RH. In this example, the fluororesin-based coating material was temporarily fixed to the inner surface of the cylindrical form by a starch paste. The fluororesin-based coating material used was the fluororesin-based film used in Reference Example 2 which was colored green.
On the layer film, a methyl methacrylate plate with a thickness of 0.5 mm is further laminated by thermal bonding as a base layer, and further, a polycarbonate prism having a length of 5 mm, a width of 5 mm, and a height of 15 mm is welded at a pitch of 20 mm as an anchor layer. The used coating material was used. When the mold was removed on day 7 of the material age, the covering material was firmly adhered. The neutralization test was performed in the same manner as in Reference Example 1.

No neutralization was observed in the test specimen left outdoors for two years, and the color difference of the fluororesin-based film was 1.2, indicating good weather resistance.

Example 2 Example 1 was repeated in the same manner as in Example 1 except that a commercially available polyethylene film obtained by applying an adhesive treatment to one surface was used to protect the fluororesin film of the fluororesin coating material. Neutralization was not observed, and the color difference of the fluororesin-based film was 1.5 and the weather resistance was good.

Example 3 and Comparative Examples 3 and 4 The concrete used in Example 1 was subjected to a chloride ion permeation test in a cement molded product. First, a fluororesin-based coating material was temporarily fixed to the inner surface of a cylindrical form by a starch paste. The fluororesin-based coating material used was a 1-mm-thick polycarbonate plate laminated by thermal bonding as a base material layer on the two-layer film used in Reference Example 2, and a 10-mm-long, 10-mm-wide anchor layer was formed. A coating material in which 10 mm-long polycarbonate prisms were welded at a pitch of 15 mm was used. On the 7th day, the mold was removed, and the covering material was firmly adhered.

Further, as a comparative example, the same anticorrosion coating as that of Comparative Example 1 was applied to a cylindrical test specimen which was removed from the mold on the 7th day. Furthermore, an untreated one was used. Immediately after removing these cylindrical specimens
Immerse in NaCl 5% solution, take out at various ages, split it into two parts by splitting, spray a fluorescein sodium 0.2% solution and silver nitrate 0.1N solution, and permeate the discolored part with chlorine ions The area was determined, and the depth was measured. The results are shown in Table 4 below.

Examples 4 to 6 The same material as that of the fluororesin-based coating material of Reference Example 2 was used.
(B) Fluororesin-based film 60μm, base layer 5mm, (c)
A neutralization promotion test and a chloride ion permeation test were performed using a 10 cm square concrete cube in the same manner as in Example 3 except that a laminate composed of a fluororesin film 100 μm and a base material layer 15 mm was used. However, good results were obtained in each case.

[Effects of the Invention] As described above, according to the present invention, since the surface of the cement molded product is coated with a fluororesin-based film having excellent weather resistance and capable of preventing permeation of harmful substances, the weather resistance is improved. Moldings with excellent heat resistance, air pollution resistance, and chemical resistance can be obtained, and the durability of the cement moldings increases.
It can withstand long-term use.

In addition, in the case of a newly-installed cement molding, it can be maintained and managed at a high level, and it is possible to have a longer life and a beautiful surface than before.

Furthermore, if a pattern or printing is performed on the surface of the fluororesin-based film, an aesthetically beautiful one can be obtained, and the long-term beauty can be maintained by the antifouling property of fluorine.

Further, according to the production method of the present invention, since the fluororesin-based coating material having a fluororesin-based film on the surface and the cement molded product can be satisfactorily fixed, the fluororesin-based coating material can be maintained without peeling. It is free and can withstand long-term use.

[Brief description of the drawings]

1 to 3 are explanatory views showing the shape of the anchor layer. FIG. 1 shows a pillar-shaped anchor layer, FIG. 2 shows a plate-shaped anchor layer, and FIG. 3 shows a mesh-shaped anchor layer. It is explanatory drawing which shows an example of the member for manufacture of the resin-coated cement molding used for the pre-installation method used. DESCRIPTION OF SYMBOLS 1 ... Fluororesin-based film 2 ... Base layer 3 ... Anchor layer 4 ... Protective layer 9 ... Outer frame

Claims (4)

(57) [Claims] 1. A laminate comprising an anchor layer, a reinforcing base material layer and a film containing a fluororesin as a main component is temporarily fixed to an outer frame so that the film surface is in contact with the laminate, and then the laminate is temporarily fixed. After assembling a casting mold having an anchor layer on the inner surface by using the frame on at least one surface, a kneaded material of a cement molding is poured into the casting mold, and after curing, the outer frame is removed to remove the cement molding and the laminate. A method for producing a cement molded article coated with a fluororesin film, characterized by integrally forming 2. The method according to claim 1, wherein a protective layer is provided on the film containing the fluororesin as a main component. 3. A fluororesin-based material comprising a laminate comprising an anchor layer, a reinforcing base material layer and a film containing a fluororesin as a main component, which is temporarily fixed to an outer frame so that the film surfaces are in contact with each other. A member for producing a film-coated cement molding. 4. The member for producing a cement molded article coated with a fluororesin film according to claim 3, wherein a protective layer is provided on the film containing the fluororesin as a main component.