JP2994038B2 - Concrete article and method of manufacturing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a concrete article and a method for producing the same,
In particular, the present invention relates to a concrete article having improved corrosion resistance and durability, which is suitable as a material for civil engineering and construction, and a method for producing the same.

BACKGROUND ART The main materials of civil engineering and construction include metal materials such as soil, rock, cement, mortar, concrete, and steel. Among them, mortar and concrete containing cement as a main component are used in various types of construction and civil engineering. It is very useful in manufacturing structures. It is inexpensive, has excellent workability, can be easily manufactured in any shape, and the resulting concrete article shows excellent performance in terms of mechanical strength and forms the basis of material civilization. It is.

Of such concrete articles, the present invention is directed to concrete molded articles such as concrete water / sewer pipes, box culverts, manholes, tunnel walls, gutters, and various types of masu. In the middle of molding, the ready-mixed concrete surface that has maintained its shape can take a state in which resin can be applied. Among such concrete articles, for example, regarding concrete fume pipes, concrete fume pipes are advantageous in that they are inexpensive and have high strength, but cannot be said to have good acid resistance and chemical resistance. . Over time under corrosive environmental conditions, there is a problem that the inner surface of the pipe itself corrodes and a fragile layer is formed.

In order to prevent such pipe body corrosion, for example,
A coating agent such as polyester resin, urethane resin, epoxy resin or acrylic resin is applied to the inner or outer surface of the pipe body and coated with the coating, or a film or sheet of polyvinyl chloride or polyolefin, such as polyester or polyolefin. Non-woven fabrics and nets are bonded to the inner and outer surfaces of the tube body together with resin to form a composite with the tube body (JP-A-48-55553, JP-A-59-62794, Kaisho 62-71614, JP-A-63-2758
No. 90).

By the way, in the various treatments described above, when a coating film is formed, the coating agent used has excellent adhesiveness to the tube body, water resistance, and chemical resistance, and the formed coating film is appropriately flexible. When a crack or the like is generated in the pipe main body, it is required to have a property capable of following the crack and close the crack, and a property of being excellent in abrasion resistance to violent flowing and sewage.

However, the corrosion-resistant layer obtained by applying a coating agent and forming a coating film is peeled off at the interface with the concrete layer due to differences in the coefficient of thermal expansion and shrinkage from the concrete layer, and the strength and The function as a composite pipe cannot be sufficiently exhibited in terms of chemical resistance. In addition, the corrosion-resistant layer has rigidity but is not flexible,
When a crack or the like occurs in the pipe body, there is a problem that the crack cannot be closed following the crack.

In addition, regarding the adhesiveness of the coating agent to the concrete layer, even when the surface of the concrete layer on which the coating film is to be formed is wet or covered with water, the coating film adheres to the water. Is desired. However, when a coating film is formed with a commercially available epoxy resin such as a bisphenol A type epoxy resin or an acrylic resin, these resins have, in addition to the property that adhesion to concrete is not very good, If water is present in the concrete coating film formation location, it is very difficult to form a good coating film that is firmly bonded to the concrete, and there is a problem that gas barrier properties and solvent resistance are not sufficient.

In addition, since the coating films of these resins have rigidity as described above, they are not flexible, so that the ability to follow cracks generated in concrete is not sufficient. Therefore, it is conceivable to soften the resin to improve crack followability,
Then, the chemical resistance and the water resistance decrease. Further, there is a problem that the wear resistance is not at a satisfactory level.

On the other hand, in the case of a process in which various resin sheets or nonwoven fabrics are adhered to the inner surface of the pipe body, the construction work is considerably complicated,
At the same time, the adhesive used for bonding sheets and nonwoven fabrics has the same problem as the case of the coating agent at the time of the formation of the coating film, so that the adhesiveness becomes insufficient and the gas barrier property is lowered.

As described above, in the conventional treatment for imparting corrosion resistance to the inner surface or the outer surface of a concrete pipe or the like, there has been a problem that sufficient corrosion resistance is not always obtained, and the construction work is complicated.

Accordingly, an object of the present invention is to provide a concrete article having a cured polysulfide-modified epoxy resin layer having excellent adhesiveness, having excellent corrosion resistance, and having good durability, and a method for producing the same. .

DISCLOSURE OF THE INVENTION The concrete article of the present invention is characterized by having a mixed layer of concrete and polysulfide-modified epoxy resin as an intermediate layer between a concrete layer and a cured polysulfide-modified epoxy resin layer.

Further, the method of the present invention for producing the above-mentioned concrete article is characterized by applying a composition containing a polysulfide-modified epoxy resin to uncured concrete.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a state near a boundary between a cured layer of a polysulfide-modified epoxy resin of a concrete article according to one embodiment of the present invention and a mixed layer of concrete and polysulfide-modified epoxy resin, () Is a schematic diagram showing an uneven state by FE-SEM observation, and (B) is a schematic diagram showing the amount of sulfur (S) by SEM-XMA observation.

BEST MODE FOR CARRYING OUT THE INVENTION The concrete article of the present invention has a mixed layer of concrete and polysulfide-modified epoxy resin between a concrete layer and a cured polysulfide-modified epoxy resin layer.

First, each layer of the concrete article of the present invention will be described.

(A) Polysulfide-modified epoxy resin cured material layer The resin component used in the cured resin layer of the concrete article of the present invention is excellent in adhesive peel strength, chemical resistance, and corrosion resistance, and is suitable for water wet surfaces and oil surfaces. A polysulfide-modified epoxy resin is used because it has a strong adhesive force, a skeleton structure of polysulfide, and flexibility and impact resistance. A concrete article coated with a cured film of a polysulfide-modified epoxy resin is excellent in corrosion resistance and can follow even when cracks occur in concrete, so that the overall durability is particularly improved. Further, since the coating film can be applied not only to the dry surface but also to the surface where water is present, the application work is very easy. In the case of a completed concrete article, for example, a tubular body, even if the pipe wall is perforated, the polysulfide-modified epoxy resin has excellent adhesive strength and impact resistance, so that peeling or breakage of the coating film portion does not occur. On the other hand, the conventional epoxy resin is brittle, so that cracks and defects are likely to occur at the time of drilling.

As the polysulfide-modified epoxy resin, a resin represented by the following general formula (1) is preferable.

(Wherein, R ¹ and R ² each represent an organic group, and X and Y
Are each -S- group, a substituent selected from the -O- group and the -NH- group, R ³ and R ⁴ are residues of epoxy prepolymer having two or more epoxy groups in each the molecule A represents an integer of 0 to 5 (provided that, when a = 0, at least one of X and Y is an -S- group);
Each represents an integer of 50. The organic groups of R ¹ and R ^{2 in} the general formula (1) include, for example, CH _{2 m} , CH ₂ OCH _{2 m} , CH ₂ CH (OH) CH _{2 m} , CH ₂ CH ₂ OCH ₂ OCH ₂ CH _{2 m} , CH ₂ CH ₂ O _m CH ₂ CH ₂ — (wherein, m represents an integer of 1 or more, preferably an integer of 1 to 10), and the like. be able to. In particular, R ¹
—CH ₂ CH ₂ OCH ₂ OCH ₂ CH ₂ — is preferred in view of ease of production and physical properties of a cured product.

As R ³ and R ⁴ , for example, OCH ₂ CH _{2 n} OCH ₂ CH (OH) CH ₂ , (Wherein, n is 1 or more, preferably an integer of 1 to 15,
⁵ represents H or CH ₃ respectively. ) And the like.

Further, in the general formula (1), the range of the average content a of S is 0 to 5 (however, when a = 0, at least one of X and Y is a -S- group), preferably 1.5 And the average content b of the skeleton is in the range of 1 to 50, preferably 1 to 30.

Compounds represented by such a general formula (1) include, for example, -S- group, -SS- group, -SS-S- group, -S
A sulfur-bonding group such as a -S-S-S-S- group or the like (except when a = 0), and both ends of which are -OH
Two sulfur-containing polymer or sulfur-containing oligomer epoxy group and closed with a reactive functional group such as SH group in the molecule - group, -NH ₂ group, -NRH group (R represents an organic group), It can be synthesized by the addition reaction with the epoxy prepolymer having an epoxy group described above.

The above epoxy prepolymer is synthesized by a condensation reaction of an aliphatic polyol or an aromatic polyol with epichlorohydrin and has two or more epoxy groups in a molecule. Examples thereof include bisphenol A type epoxy resin and bisphenol F type epoxy resin. Resins, bisphenol skeleton type epoxy resins such as halogenated bisphenol A type epoxy resins, and epoxy resins having a similar molecular structure to these resins can be given.

In synthesizing the compound of the general formula (1), the above-mentioned epoxy prepolymer is added to and reacted with the sulfur-containing polymer or the sulfur-containing oligomer in an amount of 2 equivalents or more.

Examples of such a polysulfide-modified epoxy resin include “FLEP-10” and “FLEP” manufactured by Toraythiol Co., Ltd.
EP-50 "and" FLEP-60 ".

In addition, only one kind of the polysulfide-modified epoxy resin as described above may be used, or a plurality of compounds may be used in combination.

The cured polysulfide-modified epoxy resin layer is formed by blending a curing agent with the above-described polysulfide-modified epoxy resin, applying the resulting composition to a desired location, and then leaving the coating at room temperature or heating. Can be. As the curing agent, amines, acid anhydrides and the like are mainly used. As the amines, any of a room temperature curing type, a medium temperature curing type, and a high temperature curing type can be used. Further, as the amines, any of a primary amine, a secondary amine and a tertiary amine can be used. Examples of the amines described above include aliphatic polyamines such as triethylenetetramine, polyamides such as a condensate of dimer acid and polyethylene polyamine, and aromatic polyamines such as m-xylenediamine. Modified polyamines such as adducts of polyamines with phenylglycidyl ether or ethylene oxide can also be used. This modified polyamine is preferred because of its low volatility and toxicity.

Examples of the acid anhydride include phthalic anhydride, hexahydrophthalic anhydride, and chlorendic acid.

The amount of the curing agent used is the epoxy equivalent of the polysulfide-modified epoxy resin (the weight of the polysulfide-modified epoxy resin per mole of epoxy group) and the active hydrogen equivalent of the compound having an amino group at the terminal (the amount of the compound per mole of active hydrogen). Weight), but the chemical equivalent of active hydrogen per mole of epoxy group (1 mole) 0.7 to 0.7
It is preferably 1.4 times.

Known curing accelerators, curing retarders, and the like can be further added to these curing agents.

The polysulfide-modified epoxy resin may contain an epoxy resin or another epoxy resin monomer or oligomer obtained by polymerizing an epoxy prepolymer added excessively during the synthesis, and may contain a polysulfide-modified epoxy resin. A resin having compatibility (for example, an alkyd resin, polyvinyl formal, a phenol resin, a polyvinyl acetal, a urea resin, a melamine resin, or various kinds of fatty acids) may be contained in an amount of about 50% by weight or less.

In addition, the mixed liquid of the above-mentioned polysulfide-modified epoxy resin may further include various kinds of liquids for the purpose of lowering the viscosity of the mixed liquid at the time of application to enhance film forming properties, and thereby improving the performance of the cured film. Can be added.

Examples of the solvent include ketones such as methyl ethyl ketone, esters such as ethyl acetate, chlorinated hydrocarbons such as 1,2-dichloroethane, aromatics such as toluene, and ethers such as diethyl ether. And the like.

The amount of the solvent to be added is preferably about 0.5 to 500 parts by weight based on 100 parts by weight of the polysulfide-modified epoxy resin.

When volatilization of the solvent becomes a problem or when it is desired to change the performance of the cured film, various reactive diluents suitable for the purpose may be added. As such a reactive diluent, for example, those having one or more reactive epoxy groups in the molecule are preferable.

Further, a pigment, an extender, a reinforcing material, and the like may be added to the above-mentioned homogeneous mixture. As pigments, for example, talc, calcium carbonate, kaolin, polyethylene,
Inorganic and organic fine powders such as polystyrene, organic and inorganic pigments added for coloring (earth, metal powder, lake, pigment color, carbon, etc.), triphenylmethane, anthraquinone, naphthol, etc. And the like.

Examples of fillers and reinforcing materials include, for example, inorganic powders such as cement powder, silica fume, mica, glass flakes, asbestos, fine aggregate, gravel, and fibers such as polyolefin fibers, polyacrylonitrile fibers, carbon fibers, and glass fibers. And the like. In particular, when used in applications where pebbles, sand, or gravel flows during use, such as concrete fume pipes, the purpose is to improve wear resistance.
It is preferable to add silica powder such as silica sand.

About the compounding ratio of the above additives, 100 parts by weight of polysulfide-modified epoxy resin, in the case of a pigment 0.001
It is preferable that the amount is from 300 to 300 parts by weight, 1 to 400 parts by weight for the filler, and 0.1 to 30 parts by weight for the reinforcing material.

In addition, the addition of the inorganic particles may be entirely added to the polysulfide-modified epoxy resin, or after adding a part and applying a liquid resin to the ready-mixed concrete surface, the resin is kept in a liquid state. The remaining amount may be added while the resin is in the liquid state by gravity or centrifugal force to settle in the resin liquid. May be added to the mixture, and settled in the resin solution by gravity or centrifugal force. The addition of such an extender also reduces the amount of resin used, and is also effective in terms of cost.

The thickness of such a cured polysulfide-modified epoxy resin layer can be appropriately set depending on the intended use and the like, but is preferably from 0.1 to 10 mm, particularly preferably from 0.5 to 5 mm.

(B) Mixed layer of concrete and polysulfide-modified epoxy resin In the present invention, the mixed layer of concrete and polysulfide-modified epoxy resin refers to a layer existing between the concrete layer and the cured polysulfide-modified epoxy resin layer. However, the composition is not particularly limited as long as the composition is a mixture of concrete and polysulfide-modified epoxy resin.

The specification of the mixed layer can be performed, for example, by observing the vicinity of the fracture surface by FE-SEM and measuring the distribution of sulfur by SEM-XMA.

For example, FIG. 1 shows an example of observing the form near the boundary between the polysulfide-modified epoxy resin cured material layer and the mixed layer in one embodiment of the concrete article of the present invention. First
In the figure, (A) is FE-SEM (X65 manufactured by Hitachi, Ltd.).
0, a microscopic scanning X-ray analyzer), schematically showing the unevenness between the mixed layer and the polysulfide-modified epoxy resin cured layer observed at 300 ×, (B) shows SEM-XMA (Co., Ltd.)
The distribution state of S when observed at 300 times with a Hitachi S-800 (field emission electron microscope) is schematically shown. In this concrete article, a solution of the above-mentioned polysulfide-modified epoxy resin (consisting of 100 parts by weight of the polysulfide-modified epoxy resin and 28 parts by weight of the curing agent) was placed on a 2.5 cm thick fresh concrete layer with a thickness of 4 mm. It was obtained by coating on a.

As is apparent from FIG. 1, a large amount of sulfur is distributed on the side of the cured polysulfide-modified epoxy resin layer (the area on the left side of the broken line in FIG. 1B), and the boundary (see FIG. The distribution of sulfur does not immediately become zero even after exceeding the broken line in ()), and the distribution of sulfur is recognized up to about 120 μm. This indicates that the polysulfide-modified epoxy resin has entered the concrete layer, that is, it can be seen that a mixed layer of the polysulfide-modified epoxy resin layer and the concrete layer is formed over about 120 μm.

Since the polysulfide-modified epoxy resin in such a mixed layer is formed by dispersing the cured polysulfide-modified epoxy resin layer in a concrete layer as described later, the same resin as the polysulfide-modified epoxy resin layer is used. It is generally formed.

The interface between the cured polysulfide-modified epoxy resin layer and the mixed layer preferably has irregularities as shown in FIG. 1A, and the degree of the irregularities is determined by the boundary between any two points on the boundary. And the linear distance between the two points. FE-SEM near the interface
When the linear distance (A) between any two points and the length (B) of the boundary between the two points are measured on the micrograph (× 300) obtained by The degree of unevenness is preferably 2 to 50.

The thickness of the mixed layer of the polysulfide-modified epoxy resin and concrete as described above is preferably from 5 to 500 μm, and particularly preferably from 10 to 300 μm.
When the thickness of the mixed layer is less than 5 μm, the adhesive strength becomes weak,
On the other hand, it is difficult to make the thickness more than 500 μm in terms of the production method.

(C) Concrete Layer In the present invention, as the concrete layer, sand, pebbles, gravel, crushed stone, soil, clay, or the like is used as an aggregate, and cement (eg, CaO 65% by weight, SiO ₂ 22% by weight, Al ₂
O ₃ 6 wt%, Fe ₂ O ₃ 3 wt%, SO ₃ 2 wt%, etc.) can be used. The mixing ratio of the aggregate in the concrete is preferably 40 to 90% by weight based on the solid content.

The thickness of the concrete layer as described above depends on its form,
It is about 1.5-50cm depending on the size etc.

Next, a method for producing the concrete article of the present invention comprising the above-described layers will be described.

First, a concrete layer is formed. The form of the concrete layer is not particularly limited, for example, a fume pipe,
Various shapes such as box culverts, manholes for water supply and sewerage, tunnel walls, gutters, sewage masu, underground passages, etc. can be used.

For example, when a tubular body such as a fume tube is formed, ready-mixed concrete may be poured into a cylindrical steel pipe frame and centrifuged.

Next, for wet ready-mixed concrete immediately after molding,
A mixture (composition) containing the above-described polysulfide-modified epoxy resin is applied.

As the above-mentioned application method, a method according to the situation, such as a spray method, a brush coating method, a diping method, a spraying method, can be used. When a cured product layer of a polysulfide-modified epoxy resin is formed inside a tubular body such as a fume tube, the ready-mixed concrete is poured into a cylindrical steel pipe frame and subjected to centrifugal molding to obtain an uncured tubular body. A mixture containing a polysulfide-modified epoxy resin may be dropped into a tube of a tubular body, and the mixture may be cast by centrifugal molding. In addition, the said application process can be performed several times as needed.

At the time of application, in order to complement the adhesiveness between the coating film and concrete, for example, a primer such as aminosilanes, urethane, or alkoxysilanes may be applied to the uncured concrete surface in advance, but a primer is used. It is preferred to apply directly without using. Further, a cloth-like material or a net-like material such as a polyolefin fiber or a polyacrylonitrile fiber may be laminated on the inner and outer layers of the coating layer.

As described above, the mixed solution containing the polysulfide-modified epoxy resin as described above is applied to the ready-mixed concrete, and then the ready-mixed concrete is cured, and the coating film is cured in the process, so that the concrete layer is formed. And a polysulfide-modified epoxy resin, whereby a mixed layer of concrete and polysulfide-modified epoxy resin is formed, whereby the concrete article of the present invention can be obtained.

Since the concrete article of the present invention obtained as described above uses a polysulfide-modified epoxy resin as a concrete coating agent, a mixture of a specific concrete and a polysulfide-modified epoxy resin between the concrete layer and the resin layer is obtained. A layer is formed. The reason why this mixed layer is formed is not necessarily clear, but is considered as follows.

(1) Polysulfide-modified epoxy resin contains S in the molecule
Since it contains a polysulfide bond such as a -S bond as a repeating unit, it has a higher affinity for concrete than ordinary epoxy resins.

(2) The polysulfide-modified epoxy resin is not denatured and deteriorated by water during curing, and forms a flexible and tough coating film.

(3) Since the polysulfide-modified epoxy resin has a higher specific gravity than water (approximately 1.2 g / cm ³ ), it can be replaced with water near the surface of the ready-mixed concrete by gravity or centrifugal force.

For the reasons described above, it is considered that the polysulfide-modified epoxy resin takes a structure deeply rooted near the surface of the ready-mixed concrete (forms a mixed layer).

The ready-mixed concrete article coated with the polysulfide-modified epoxy resin layer is further processed through a curing acceleration process such as steam curing, and becomes a product. Since the adhesive strength to the concrete does not decrease, it is possible to obtain a concrete article far superior to a conventional article coated with an epoxy resin.

In addition, the polysulfide-modified epoxy resin exhibits the following excellent properties as compared with conventional epoxy resins.
In other words, since the polysulfide-modified epoxy resin contains a flexible polysulfide chain containing sulfur in the molecule, it has a moderate flexibility as compared with the conventional hard and brittle epoxy resin, and has excellent impact resistance and abrasion resistance. Sex has also been improved. The conventional epoxy resin with improved flexibility decreases other physical properties such as chemical resistance (acid / alkali), solvent resistance, gas barrier property, etc., whereas polysulfide-modified epoxy resin has the opposite effect. The above physical properties are improved, and the properties are superior to those of a hard epoxy resin. These properties are believed to affect the manufacturing process and performance of the concrete articles of the present invention.

 The present invention is described in more detail by the following examples.

Example 1 Unit cement amount 400 kg / m ³ or more, water cement ratio 37-45
%, And a cement composition prepared in the range of slumps 5 to 12 cm flows into a cylindrical mold (inner diameter 26 cm, length 30 cm) rotating at an acceleration of 10 G by a centrifugal molding machine, and is almost uniformly spread on the inner surface. After casting, the gravitational acceleration of 30G
The cement composition was compacted by rotating the mold for minutes, and a hollow ready-mixed concrete pipe (thickness 30 mm) was formed.

Then, without removing the ready-mixed concrete tube from the formwork, while slowly rotating the formwork, 100 parts by weight of a polysulfide-modified epoxy resin (“FLEP-60” manufactured by Toraythiol Co., Ltd.) was applied to the inner surface of the ready-mixed concrete tube. When,
100 g of a mixed liquid composed of 28 parts by weight of a modified aliphatic polyamine ("Ditoclar X-2392" manufactured by Daito Sangyo Co., Ltd.) was gradually dropped as a curing agent.

After the completion of the dropping, the mold was again rotated at a gravitational acceleration of 30 G for 10 minutes, and the mixed solution was cast and applied to the inner surface of the ready-mixed concrete pipe.

Subsequently, the mold was removed from the centrifugal molding machine, and at room temperature until the ready-mixed concrete pipe reached practical strength.
Cured for 28 days. After curing, the concrete tube was released from the mold to obtain a concrete tube having a polysulfide-modified epoxy resin cured film having a thickness of about 500 μm on the inner surface.

The cured coating film was subjected to an adhesion peeling test using a Kenken-type adhesion tester. As a result, it was confirmed that the peeling of the cured film was entirely due to the destruction of the concrete layer, and that the adhesion of the cured film to concrete was extremely excellent.

Also, cut this concrete pipe and change its cross-sectional form.
Observation and composition analysis by SEM-XMA (X-650, manufactured by Hitachi, Ltd., microscopic scanning X-ray analyzer) revealed that an average of 123 μm was found on the boundary between the concrete layer and the cured polysulfide-modified epoxy resin layer. An intermediate layer in which the thick concrete and the polysulfide-modified epoxy resin were mixed was confirmed.

Furthermore, the coated surface of the concrete pipe was
When immersed in a 3% aqueous sulfuric acid solution for 3 months, no change was observed in the cured product film, and the adhesion to concrete did not change.

Example 2 A cement composition was obtained by mixing 950 g of cement, 1910 g of sand, 400 g of water, and 19 g of a fluidizing agent (“Cell Flow DF” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). This composition was rotated by a centrifugal molding machine at an acceleration of 10 G in a cylindrical form (inner diameter 20 cm, length 20 c
m), and cast so that the inner surface becomes almost uniform.
The number of revolutions was further increased, and the mold was rotated at a gravitational acceleration of 30 G for 10 minutes to compact the cement composition, thereby forming a hollow ready-mixed concrete pipe (thickness: 13 mm).

Then, without removing the ready-mixed concrete tube from the formwork, while slowly rotating the formwork at a gravitational acceleration of 2 to 3 G, a polysulfide-modified epoxy resin (“FLEP- 6
200 g of a mixed solution comprising 100 parts by weight of 0 ") and 28 parts by weight of a modified aliphatic polyamine (" Ditoclar X-2392 "manufactured by Daito Sangyo Co., Ltd.) as a curing agent was gradually added dropwise.

After the completion of the dropping, the mold was again rotated at a gravitational acceleration of 30 G for 5 minutes, and the mixed solution was cast and applied to the inner surface of the ready-mixed concrete pipe. 440g of silica sand (No.5) while rotating at 30G
Was added almost uniformly, and the mixture was rotated for 20 minutes to cure the polysulfide-modified epoxy resin mixture.

Subsequently, the mold was removed from the centrifugal molding machine, and at room temperature until the ready-mixed concrete pipe reached practical strength.
Cured (10 days). After curing, the concrete tube was released from the mold to obtain a concrete fume tube having a polysulfide-modified epoxy resin cured film having a thickness of about 4 mm on the inner surface.

The cured coating film was subjected to an adhesion peeling test using a Kenken-type adhesion tester. As a result, the adhesive strength is 42 kgf / cm ²
All of the peeling of the cured film was due to the destruction of the concrete layer, and it was confirmed that the adhesion of the cured film to the concrete was extremely excellent.

The thickness of the intermediate layer determined by cutting this concrete fume pipe and observing the cross-sectional form by SEM-XMA in the same manner as in Example 1 was 100 μm on average.

Upon cutting the fume tube, the concrete layer and the resin layer were integrated and did not peel off during cutting. Similarly, chipping and peeling did not occur in the perforation of the tube wall.

On a micrograph (300 times) obtained by FE-SEM (S-800, manufactured by Hitachi, Ltd., field emission electron microscope),
The linear distance (A) between any two points and the boundary length (B) between them were measured, and the degree of unevenness (B / A) was determined. The degree of unevenness was about 3.5.

In addition, the coated surface of the concrete pipe is 10%
When immersed in a sulfuric acid aqueous solution for 3 months, no change was observed in the cured product film, and the adhesiveness to concrete did not change.

Example 3 In Example 2, 100 parts by weight of a polysulfide-modified epoxy resin (“FLEP-60” manufactured by Toray Thiokol Co., Ltd.) was used without using silica sand (No. 5), and a modified aliphatic polyamine (Daito Sangyo ( Co., Ltd. “Daitoclar X-239”
2 ") A composite fume tube made of concrete was manufactured by a centrifugal molding machine in the same manner except that only 200 g of a mixed solution consisting of 28 parts by weight was coated, and a cured film of a polysulfide-modified epoxy resin having a thickness of about 3 mm was formed on the inner surface. Was obtained.

The cured coating film was subjected to an adhesion peeling test using a Kenken-type adhesion tester. As a result, the adhesive strength is 39 kgf / cm ²
All the peeling of the cured film was due to the destruction of the concrete layer, and it was confirmed that the adhesion of the cured film to the concrete was extremely excellent.

The thickness of the intermediate layer obtained by cutting this concrete fume pipe and observing the cross-sectional form by SEM-XMA in the same manner as in Example 1 was 95 μm on average, and the same as in Example 2 by FE-SEM. When the degree of unevenness at the boundary between the cured polysulfide-modified epoxy resin layer and the intermediate layer was measured, the degree of unevenness was about 3.1.

In addition, the coated surface of this concrete pipe at 25 ℃,
When immersed in a 10% sulfuric acid aqueous solution for 3 months, no change was observed in the cured product film, and the adhesiveness to concrete did not change.

Example 4 100 parts by weight of a polysulfide-modified epoxy resin ("FLEP-60" manufactured by Toraythiol Co., Ltd.) and 28 parts by weight of a modified aliphatic polyamine ("Ditoclar X-2392" manufactured by Daito Sangyo Co., Ltd.) as a curing agent And 20 parts by weight of methylene chloride and silica fine particles (“Aerosil manufactured by Nippon Aerosil Industries, Ltd.)
R202 ") A concrete fume tube was manufactured by a centrifugal molding machine in the same manner as in Example 2 except that 250 g of a mixed solution consisting of 5 parts by weight was used, and a polysulfide-modified epoxy having a thickness of about 3.8 mm was formed on the inner surface. A concrete fume tube having a cured resin film was obtained.

The cured coating film was subjected to an adhesion peeling test using a Kenken-type adhesion tester. As a result, the adhesive strength is 42 kgf / cm ²
All the peeling of the cured film was due to the destruction of the concrete layer, and it was confirmed that the adhesion of the cured film to the concrete was extremely excellent.

The thickness of the intermediate layer obtained by cutting this concrete fume pipe and observing the cross-sectional form with SEM-XMA as in Example 1 was 120 μm on average, and as in Example 2 with FE-SEM. When the degree of unevenness at the boundary between the cured polysulfide-modified epoxy resin layer and the intermediate layer was measured, the degree of unevenness was about 3.5.

Example 5 A cement composition was obtained by mixing 475 g of cement, 955 g of sand, 200 g of water and 8 g of a fluidizing agent (“Cell Flow DF” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). This composition is placed in a box-shaped form (length 260 mm ×
(200 mm wide x 40 mm deep). On this wet ready-mixed concrete, 100 parts by weight of a polysulfide-modified epoxy resin (“FLEP-60” manufactured by Toray Thiokol Co., Ltd.) and a modified aliphatic polyamine (“Ditoclar X-manufactured by Daito Sangyo Co., Ltd.”) as a curing agent were used. 250 g of a mixed solution consisting of 28 parts by weight of 2392 ") was applied.

After curing this mold at room temperature for 10 days, a concrete piece on which the resin was laminated was released from the mold to obtain a concrete piece having a resin layer laminated to a thickness of about 4 mm.

An adhesive peel test was performed on the cured film of the polysulfide-modified epoxy resin of the concrete piece using a Kenken-type adhesion tester. As a result, the adhesive strength is 35 kgf / cm ²
All of the peeling of the cured film was due to the destruction of the concrete layer, and it was confirmed that the adhesion of the cured film to the concrete was extremely excellent.

The thickness of the intermediate layer obtained by cutting this concrete fume pipe and observing the cross-sectional form by SEM-XMA in the same manner as in Example 1 was 95 μm on average, and the same When the degree of unevenness at the boundary between the cured polysulfide-modified epoxy resin layer and the intermediate layer was measured, the degree of unevenness was about 3.1.

Comparative Example 1 In the same manner as in Example 1, a hollow ready-mixed concrete pipe (25 mm in thickness) was molded.

After curing for 10 days, the inner surface between the fumes was sanded to remove latencies. Next, 100 parts by weight of a polysulfide-modified epoxy resin (“FLEP-60” manufactured by Toray Thiokol Co., Ltd.) and a modified aliphatic polyamine (“Ditoclar X-2392” manufactured by Daito Sangyo Co., Ltd.) Example 2 200 g of a mixed solution consisting of parts by weight
Then, it was centrifugally molded in the same manner as described above, and was coated with a polysulfide-modified epoxy resin resin to a thickness of about 4 mm. After the resin was completely cured, the cured film was subjected to an adhesion peeling test using a Kenken-type adhesion tester. As a result, the adhesive strength was as low as 23 kgf / cm ^2, and the cured film was peeled off at the adhesive surface.

The thickness of the intermediate layer obtained by cutting this concrete fume pipe and observing the cross-sectional form by SEM-XMA as in Example 1 was 2 μm on average, and
When the degree of unevenness at the boundary between the polysulfide-modified epoxy resin cured material layer and the intermediate layer was measured by FE-SEM in the same manner as described above, the degree of unevenness was about 1.3.

Comparative Example 2 A concrete fume tube was manufactured in the same manner as in Comparative Example 1, and a polysulfide-modified epoxy resin was directly coated without removing the latence on the inner surface of the fume tube to manufacture a composite fume tube made of concrete. After the resin was completely cured, the cured film was subjected to an adhesion peeling test using a Kenken-type adhesion tester. As a result, the adhesive strength was as low as 9 kgf / cm ^2, and the cured film was broken at the adhesive interface.

The thickness of the intermediate layer obtained by cutting this concrete fume tube and observing the cross-sectional form by SEM-XMA in the same manner as in Example 1 was 3 μm on average.
When the degree of unevenness at the boundary between the cured polysulfide-modified epoxy resin layer and the intermediate layer was measured by FE-SEM in the same manner as in the above, the degree of unevenness was about 1.5.

Comparative Example 3 In the same manner as in Example 5, the cement composition was put into a box-shaped formwork, which was cured for 10 days in a tube, and then a flat plate made of concrete alone was obtained. On this concrete plate, a polysulfide-modified epoxy resin (“FLEP-6” manufactured by Toray Thiokol Co., Ltd.)
0 ") 100 parts by weight and a mixed liquid consisting of 28 parts by weight of a modified aliphatic polyamine (" Ditoclar X-2392 "manufactured by Daito Sangyo Co., Ltd.) as a curing agent was applied, and the tube was cured for 10 days. A polysulfide-modified epoxy resin layer having a thickness of about 4 mm was formed.

Thereafter, the concrete flat plate on which the resin was laminated was released from the mold, and the cured coating film was subjected to an adhesion peeling test using a Kenken-type adhesion tester. As a result, the adhesive strength is 14
kgf / cm ² , the cured film broke at the adhesive interface.

The thickness of the intermediate layer obtained by cutting this concrete fume tube and observing the cross-sectional form by SEM-XMA in the same manner as in Example 1 was 3 μm on average.
When the degree of unevenness at the boundary between the cured polysulfide-modified epoxy resin layer and the intermediate layer was measured by FE-SEM in the same manner as in the above, the degree of unevenness was about 1.2.

Comparative Example 4 In Example 2, as the resin for the resin layer formed on the inner surface of the concrete, 100 parts by weight of a polysulfide-modified epoxy resin (“FLEP-60” manufactured by Toray Thiokol Co., Ltd.)
Instead of 200 g of a mixed solution comprising 28 parts by weight of a modified aliphatic polyamine ("Ditoclar X-2392" manufactured by Daito Sangyo KK) as a curing agent, a wet adhesive epoxy resin ("ADEKARESIN" manufactured by Asahi Denka Kogyo KK) 100 parts by weight of EPES ") and a curing agent (" ADEKA HARDNER ER235G "manufactured by Asahi Denka Kogyo KK) 30
Using a mixed solution of 200 parts by weight, this was dropped on the inner surface of the ready-mixed concrete tube, and a composite fume tube made of concrete was manufactured in the same manner by a centrifugal molding machine except that it was cast and applied. A concrete fume tube having a thick cured film was obtained.

The cured coating film was subjected to an adhesion peeling test using a Kenken-type adhesion tester. As a result, the adhesive strength was 11 kgf / cm ²
All the peeling of the cured film occurred on the adhesive surface.

The perforation of the obtained fume tube into the tube wall was performed in Example 2.
As a result, the resin was separated from the concrete.

Comparative Example 5 In Example 2, 100 parts by weight of a polysulfide-modified epoxy resin (“FLEP-60” manufactured by Toraythiol Co., Ltd.) was used as a resin for the resin layer formed on the inner surface of the concrete.
Instead of 200 g of a mixed liquid comprising 28 parts by weight of a modified aliphatic polyamine ("Ditoclar X-2392" manufactured by Daito Sangyo Co., Ltd.) as a curing agent, an epoxy resin ("Epicoat 828" manufactured by Yuka Shell Epoxy Co., Ltd.) was used. ) 200 g of a mixed solution consisting of 100 parts by weight of a hardening agent ("Ditoclar I-2095" manufactured by Daito Sangyo Co., Ltd.) was dropped onto the inner surface of a ready-mixed concrete pipe, and cast and applied. A composite fume tube made of concrete was manufactured by a centrifugal molding machine in the same manner except that
A concrete fume tube having a hardened film with a thickness of about 4 mm on the inner surface was obtained.

The cured coating film was subjected to an adhesion peeling test using a Kenken-type adhesion tester. As a result, the adhesive strength is 2.5 kgf / cm ²
All the peeling of the cured film occurred on the adhesive surface.

INDUSTRIAL APPLICABILITY The concrete article of the present invention has a high coating density because the cured coating is made of a polysulfide-modified epoxy resin, and has improved chemical and solvent resistance to acids and alkalis compared to ordinary epoxy resins. It also has good gas barrier properties and excellent corrosion resistance. Therefore, this concrete article has excellent durability. Also,
Since the cured coating of the concrete article is moderately flexible and has excellent flexibility and impact resistance, even if a crack is generated in the main body, it is possible to close the crack according to the crack.

In addition, since the cured coating can be easily formed on a water-moistened surface or a fresh concrete surface, the work on the concrete body is easier than before. Therefore, a concrete article excellent in corrosion resistance and durability can be manufactured with high productivity.

Furthermore, in the concrete article of the present invention, a mixed layer of a polysulfide-modified epoxy resin and concrete is formed near the surface of the ready-mixed concrete, and the polysulfide-modified epoxy resin has a structure deeply rooted, so that the polysulfide-modified epoxy resin has The adhesion of the cured epoxy resin layer to concrete is extremely strong.

Such concrete articles of the present invention include concrete water and sewer pipes, box culverts, manholes,
It is suitable for concrete moldings such as tunnel walls, gutters, and various types of masu.

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroyoshi Kuramoto 3220-5 Anesaki, Ichihara-shi, Chiba W-203 (58) Field surveyed (Int. Cl. ⁶ , DB name) B32B 13/00-13/14 B28B 21 / 30,19 / 00 F16L 58/10

Claims (12)

(57) [Claims] 1. A concrete article comprising a mixed layer of concrete and polysulfide-modified epoxy resin as an intermediate layer between a concrete layer and a cured polysulfide-modified epoxy resin layer. 2. The concrete article according to claim 1, wherein said intermediate layer has a thickness of 5 to 500 μm. 3. The concrete article according to claim 1 or 2, wherein said polysulfide-modified epoxy resin has the following general formula: (Wherein, R ¹ and R ² each represent an organic group, and X and Y
Are each -S- group, a substituent selected from the -O- group and the -NH- group, R ³ and R ⁴ are residues of epoxy prepolymer having two or more epoxy groups in each the molecule A represents an integer of 0 to 5 (provided that, when a = 0, at least one of X and Y is an -S- group);
Each represents an integer of 50. A concrete article characterized by being a polymer epoxy compound represented by the formula: 4. The concrete article according to claim 3, wherein R ¹ in the polysulfide-modified epoxy resin represented by the general formula is —CH ₂ CH ₂ OCH ₂ OCH ₂ CH ₂ —, and the average of a Value is 1.5 or more 2.
Concrete article characterized by being 5 or less. 5. The concrete article according to claim 1, wherein the cured polysulfide-modified epoxy resin layer contains an extender and / or a reinforcing material. Concrete goods. 6. A concrete article according to claim 1, wherein said concrete article is a fume tube. 7. A method for producing a concrete article having a mixed layer of concrete and a polysulfide-modified epoxy resin as an intermediate layer between a concrete layer and a cured polysulfide-modified epoxy resin layer, the method comprising: A method for producing a concrete article, comprising applying a composition containing a polysulfide-modified epoxy resin to the composition. 8. The method for manufacturing a concrete article according to claim 7, wherein said intermediate layer has a thickness of 5 to 500 μm. 9. The method for producing a concrete article according to claim 7, wherein said polysulfide-modified epoxy resin has the following general formula: (Wherein, R ¹ and R ² each represent an organic group, and X and Y
Are each -S- group, a substituent selected from the -O- group and the -NH- group, R ³ and R ⁴ are residues of epoxy prepolymer having two or more epoxy groups in each the molecule A represents an integer of 0 to 5 (provided that, when a = 0, at least one of X and Y is an -S- group);
Each represents an integer of 50. A method for producing a concrete article, which is a polymer epoxy compound represented by the following formula: 10. The method for producing a concrete article according to claim 9, wherein R ¹ in the polysulfide-modified epoxy resin represented by the general formula is —CH ₂ CH ₂ OCH ₂ OCH ₂ CH ₂ —, The average value of a is 1.5 or more 2.
A method for producing a concrete article, wherein the number is 5 or less. 11. The concrete article according to any one of claims 7 to 10, wherein the cured polysulfide-modified epoxy resin layer contains a filler and / or a reinforcing material. A method of manufacturing a concrete article. 12. The method for producing a concrete article according to any one of claims 7 to 11, wherein the fluid fresh concrete is formed into a tubular shape by a centrifugal molding method, and then the uncured concrete is formed. A method for producing a concrete article, comprising centrifugally applying a composition containing a polysulfide-modified epoxy resin to an inner surface.