JPH09194272A - Anticorrosive concrete pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anticorrosive concrete pipe provided with an anticorrosive lining layer excellent in characteristic such as acid resistance and useful as a sewer pipe. SOLUTION: A mixture consisting of 1-22wt.% alkoxysilyl group-contg. monomer shown by R<1> R<2> (3-n) SiXn (where R<1> is a univalent org. group having a polymerizable double bond, R<2> is 1-4C alkyls, X is 1-4C alkoxyl group, and (n) is an integer of 1 to 3) and 80-99wt.% monomer copolymerizable with the former monomer is emulsion-copolymerized, an anticorrosive lining layer consisting of the obtaine dcopolymer and having -35 to 50 deg.C glass transition temp. is produced on the inner face of a concrete layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anticorrosion concrete pipe having an anticorrosion lining layer having excellent adhesion to a concrete surface, acid resistance, and abrasion resistance on the inner surface, and particularly useful as a sewer pipe. Is.

[0002]

2. Description of the Related Art Recently, concrete pipes have been found to be ragged in about 20 years due to the frequent occurrence of road collapses caused by breakage of sewer pipes. When concrete pipes corrode, their surfaces melt and become ragged, and the terrible ones can even collapse when touched. Corrosion / deterioration of this concrete pipe causes sulfur contained in sewage in the form of sulfate to be converted to hydrogen sulfide by a microorganism called sulfate-reducing bacteria, which is then converted to sulfuric acid by a microorganism called sulfur-oxidizing bacteria in the gas phase. Then, it reacts with the concrete components to produce ethrin guide (3CaO ・ Al ₂ O ₃ / 3CaSO ₄・ 32H ₂ O),
It is known that this reaction occurs when concrete takes in bound water and expands.

As measures against this, some methods have been proposed in which a corrosion-proof lining layer is provided on the inner surface of a concrete pipe during the production thereof so that the generated sulfuric acid does not directly corrode the concrete layer. Currently, as a method for producing an anticorrosion concrete pipe that has been put into practical use, after the cement concrete layer is compacted, this concrete layer is in an uncured state, and the resin is made of acid-resistant resin or resin and inorganic fine aggregate. There is a method of forming an anticorrosion lining layer on the inner surface of a pipe by a centrifugal force method using mortar. Examples of the acid-resistant resin used in this method include polyvinyl chloride, poly (meth) acrylic acid ester [(meth) acrylic is a generic term for acrylic and methacrylic, and the same applies hereinafter], polystyrene, and vinyl polymers such as polyfluorinated olefins. Especially, vinyl chloride resin is the best.

[0004]

However, since these resins have a poor affinity with the cement phase (including hydrates and non-hydrates) and inorganic aggregates, the anticorrosion lining layer after formation has a base concrete. There are problems such as peeling from the layer, desorption of the contained fine aggregate from the resin mortar layer and generation of pores, and loss of acid resistance and water impermeability. The object of the present invention is to solve the above problems, the anticorrosion lining layer is excellent in water resistance, acid resistance, toughness, wear resistance, excellent adhesiveness, peeling and cracking and fine aggregate drop-off. The purpose of the present invention is to provide a corrosion-resistant concrete pipe having extremely excellent acid water blocking properties and durability.

[0005]

The anticorrosive concrete pipe of the present invention has a structure of (a) a general formula R ¹ R ² _(3-n) SiX _n (wherein R ¹ is a polymerizable double bond) on the inner surface of the concrete layer. A monovalent organic group having, R ² is an alkyl group having 1 to 4 carbon atoms, X is an alkoxyl group having 1 to 4 carbon atoms, and n is an integer of 1 to 3). 1 to 20% by weight and (b) 80 to 99% by weight of a monomer copolymerizable with the above (a) by emulsion copolymerization and the glass transition temperature is -35 to 50 ° C. It is characterized by comprising an anticorrosion lining layer containing the copolymer as a constituent component.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The alkoxysilyl group-containing monomer of the component (a) in the present invention is an alkoxysilyl group as a side chain to the alkoxysilyl group-containing copolymer used in the present invention (hereinafter referred to as the copolymer according to the present invention). It is a monomer for introducing a compound represented by the general formula R ¹ R ² _(3-n) SiX _n . R ¹
Is a monovalent organic group having a polymerizable double bond, a vinyl group,
(Meth) acryloxyalkyl group, vinylphenyl group and the like, R ² is an alkyl group having 1 to 4 carbon atoms, X is an alkoxyl group having 1 to 4 carbon atoms, and n is selected from 1, 2, and 3. Be done.

Examples of this monomer include vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, vinyltris (β-methoxyethoxy) silane and γ- (meth).
Acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ
-(Meth) acryloxypropyldimethylmethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ- (meth) acryloxypropyldimethylethoxysilane, trimethoxy Examples include silylstyrene, dimethoxymethylsilylstyrene, triethoxysilylstyrene, diethoxymethylsilylstyrene and the like. One or more of these are used in an amount of 1 to 20% by weight based on the total amount of the monomer components. If it is less than 1% by weight, the formed film has a low crosslink density, and the durability such as water resistance and abrasion resistance is insufficient. If it exceeds 20% by weight, the crosslink density is too high and the formed film is It becomes brittle, and further, an emulsion of a copolymer obtained by emulsion copolymerization (hereinafter,
The storage stability of the copolymer emulsion according to the present invention) is also impaired.

The monomer as the component (b) is the main component of the copolymer according to the present invention, and is 80 to 99% by weight based on the total amount of the monomer components in order to obtain the required characteristics. It is possible to use a system monomer or a diene monomer, but for the purpose of the present invention, it is necessary that the copolymer according to the present invention has excellent water resistance and acid resistance. For this reason, it is preferable to occupy a large proportion of the component (b). Examples of the monomer include vinyl chloride, vinylidene chloride, styrene, a methacrylic acid ester having an alkyl group having 1 to 18 carbon atoms, and an alkyl group having 2 carbon atoms. Examples thereof include acrylic acid ester of -18, vinyl ester of fatty acid having carbon number of propionic acid or more, acrylonitrile, ethylene, propylene, butadiene, isoprene and chloroprene. It is preferable that the monomer which accounts for this large proportion is 90 to 99.5% by weight in the component (b).

Further, it is a monomer having a functional group other than the polymerizable double bond, which contributes to the stability of the copolymer emulsion according to the present invention and the adhesiveness of the film, and is used in a relatively small amount. Examples of the monomer include a carboxyl group-containing monomer such as acrylic acid, methacrylic acid and maleic anhydride, or an anhydride group-containing monomer thereof, 2-hydroxyethyl (meth) acrylate, 2-
Hydroxyl group-containing monomer such as hydroxypropyl (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth)
Amide group-containing monomers such as acrylamide and diacetone (meth) acrylamide, amino group-containing monomers such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate, methoxyethyl (meth) acrylate, butoxyethyl ( Alkoxyl group-containing monomers such as (meth) acrylate, glycidyl (meth)
Acrylics, glycidyl group-containing monomers such as glycidyl allyl ether are exemplified, and divinyl is used as a monomer used in a small amount to improve the elasticity and strength of the copolymer according to the present invention by crosslinking during polymerization. Benzene, allyl (meth) acrylate, ethylene glycol di (meth)
Examples thereof include monomers having two or more radically polymerizable double bonds in one molecule such as acrylate, diethylene glycol di (meth) acrylate, and trimethylolpropane tri (meth) acrylate. Also, vinyl acetate and methyl acrylate can be used in a small amount. It is possible to simultaneously satisfy the required performance by using two or more kinds of the monomers as the component (b) in combination rather than one kind. But,
The combination of monomers and the determination of the amount ratio must first be made in consideration of the glass transition temperature of the copolymer according to the present invention.

The copolymer according to the present invention can be produced by a known emulsion polymerization method using each of the above monomers. The obtained emulsion of this copolymer, that is, the copolymer emulsion according to the present invention, is advantageous because it can be used as an emulsion without isolation of the copolymer. The copolymerization method includes a batch polymerization method in which monomers are collectively polymerized, a monomer alone or deionized water, an additional polymerization method of a monomer emulsion liquid emulsified with a surfactant, and a single amount of core and shell. Examples thereof include a core / shell polymerization method in which the body composition is changed, and a power polymerization method in which the monomer composition is continuously changed and polymerized. Of these methods, the core / shell polymerization method is also useful as a means for suppressing the progress of the crosslinking reaction of the alkoxysilyl groups in the copolymer emulsion or the blend thereof according to the present invention. That is, the core portion is copolymerized with an alkoxysilyl group-containing monomer, and the core portion is protected by an alkoxysilyl group-free shell portion, or a highly reactive trimethoxysilyl group-containing monomer is added to the core portion. There is also a method in which a dimethoxysilyl group, a triethoxysilyl group, and a diethoxysilyl group-containing monomer having low reactivity are copolymerized with the shell portion.

Surfactants used in emulsion polymerization include anionic surfactants such as alkyl or alkylallyl sulphates, alkyl or alkylallyl sulfonates, dialkyl sulfosuccinates, alkyl trimethyl ammonium chloride, alkyl benzyl ammonium chloride, etc. And cationic surfactants, nonionic surfactants such as polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl ethers and polyoxyethylene carboxylic acid esters. These surfactants may be used alone or in combination of two or more, but if the amount is too small, a large amount of agglomerates will be generated in the produced copolymer emulsion of the present invention. However, the resulting coating also does not exhibit good physical properties.
Also, if the amount is too large, the particle size of the emulsion particles becomes fine, the emulsion viscosity increases too much, and the water resistance of the coating film becomes poor. Therefore, the amount of the surfactant used is preferably 0.5 to 15 parts by weight, more preferably 1 to 7 parts by weight, based on 100 parts by weight of all the monomers.

Further, in order to remarkably improve the durability such as water resistance of the film formed from the obtained copolymer emulsion according to the present invention and obtain the performance close to that of the solution type, a surfactant as a surfactant is used at the time of polymerization. Preference is given to using reactive surfactants. Examples of this reactive surfactant include JP-A-54-144317, JP-A-55-115419, JP-A-62-34947, JP-A-58-203960, JP-A-4-53802, and JP-A-62- 104802,
Anionic reactive surfactants described in JP-A-49-40388, JP-A-52-134658 and JP-B-49-46291, and JP-A-53-126093 and JP-A-56-28208. , JP
4-50204, JP-A-62-104802, JP-A-50-98484, etc., and polymerizable with nonionic reactive surfactants or quaternary ammonium salts and tertiary amine salts. Examples include cationic reactive surfactants containing groups.

The radical polymerization initiator used in the present invention includes water-soluble persulfates such as potassium persulfate and ammonium persulfate, hydrogen peroxide solution, t-butyl hydroperoxide, and azobisamidinopropane hydrochloride. Examples include oil-soluble types such as benzoyl peroxide, cumene hydroperoxide, dibutyl peroxide, diisopropyl peroxydicarbonate, cumyl peroxyneodecanoate, cumyl peroxy octoate, and azobisisobutyronitrile. To be done. Furthermore, if necessary, acidic sodium sulfite, Rongalit, L
-A redox system in combination with a reducing agent such as ascorbic acid can also be used. The amount of the polymerization initiator used is usually 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of all the monomers.

In producing the copolymer emulsion according to the present invention, it is preferable to control the pH during the polymerization to 6.5 to 7.5 in order to suppress the hydrolysis and condensation of the alkoxysilyl group. The polymerization is usually carried out at a temperature of 10 to 90 ° C. At the end of emulsion polymerization, it is preferable to adjust the pH to 7 to 8 by adding a basic substance in order to prevent an undesirable crosslinking reaction of the copolymer and further improve the storage stability. Examples of the basic substance include ammonia, amines, alkanolamines, caustic alkali and the like. Although the copolymer emulsion according to the present invention can be obtained as described above, it can be used as it is in the form of an emulsion as described above.

The copolymer according to the present invention is required to have a glass transition temperature of -35 to 50 ° C. If it is lower than -35 ° C, the film formed from this copolymer will be soft. Too much, the mechanical strength and wear resistance decrease,
When the temperature is higher than 50 ° C, a continuous film is not formed at 60-80 ° C, which is the heating and curing temperature in the existing centrifugal reinforced concrete pipe manufacturing method, and good acid resistance and water resistance cannot be obtained. The glass transition temperature (Tg) of the copolymer is a value calculated by the following formula. 1 / Tg = Σ (Wi / Tgi) Tg: glass transition temperature of copolymer (absolute temperature display) Tgi: glass transition temperature of homopolymer of monomer component (i) (absolute temperature display) Wi: co-weight Weight fraction of component (i) in coalescence (TG. Fox, method of Bull. Am. Phys. Soc. Vol. 1, p. 123, published in 1956)

The anticorrosion concrete pipe of the present invention is a general term for an anticorrosion lining layer (a resin layer made of the copolymer according to the present invention or a resin mortar layer made of the copolymer and fine aggregates) on the inner surface of the concrete pipe. .), But when the inner surface of the concrete pipe is extremely rough due to coarse aggregate such as gravel and crushed stone in the concrete layer, in order to completely cover the rough surface with the anticorrosion lining layer, The average thickness of the anticorrosion lining layer must be increased, resulting in cost increase. In such a case, it is advisable to provide a resin cement mortar using cement, an inorganic fine aggregate and a copolymer emulsion as an intermediate layer, and to further smooth the surface before applying the anticorrosion lining layer. The use of the copolymer emulsion in the cement mortar of the intermediate layer improves the fluidity of the cement mortar, and
This is to ensure complete adhesion between the concrete and the intermediate layer.

When the protective layer on the inner surface of the concrete pipe is formed of two layers, that is, the intermediate layer and the anticorrosion lining layer, the two copolymer emulsions used are usually the copolymer emulsion according to the present invention (usually, It gives a film that withstands the alkalinity of cement.), But it is also possible to use the copolymer emulsion according to the present invention only for the anticorrosion lining layer and use another copolymer emulsion for the intermediate layer. Is. The copolymer emulsion used for the intermediate layer has film-forming properties at the curing temperature of anticorrosion concrete pipes, and if the resulting film is water and alkali resistant and has excellent miscibility with cement mortar, it has alkoxysilyl It does not need to have a group, and can be widely selected from various synthetic resins and synthetic rubber emulsions. Examples of the main component in such an emulsion include vinyl chloride / (meth) acrylic acid ester, vinyl chloride / higher fatty acid vinyl, styrene / (meth) acrylic acid ester, styrene / butadiene, styrene / isoprene, methyl methacrylate / butadiene. , Vinylidene chloride / (meth)
Examples thereof include acrylic acid esters, combinations of (meth) acrylic acid esters having different alkyl group carbon atoms, and copolymers of vinyl chloride / ethylene / vinyl acetate, ethylene / vinyl acetate and the like.

Although any known method can be used for producing the anticorrosion concrete pipe of the present invention, after the cement concrete pipe is compacted, only the copolymer emulsion according to the present invention is obtained in a state where the concrete layer is uncured. The resin layer used is centrifugal lining, and the resin mortar layer using the copolymer emulsion and fine aggregate according to the present invention is centrifugal lining, and an intermediate layer using cement, inorganic aggregate and copolymer emulsion is used. A resin layer using only the copolymer emulsion according to the present invention was subjected to sequential centrifugal lining while each inner layer was in an uncured state, or a cement, an inorganic aggregate and a copolymer emulsion were used. A resin mortar layer using the intermediate layer, the copolymer emulsion according to the present invention, and a fine aggregate is formed in an uncured inner layer. By sequentially centrifugal lining in the state,
A method of forming on the inner surface of the concrete pipe and curing and curing is preferable.

The resin layer using only the copolymer emulsion according to the present invention is obtained as it is because the copolymer emulsion is obtained as an emulsion having a solid content concentration of 30 to 60% by weight and a viscosity of 10 to 1,000 cP. Centrifugal force Put into the inner surface of each layer in the uncured state inside the rotating frame, rotate the mold, and paint by centrifugal force (high speed rotation of 30 to 50 G × 1 to 2
Minutes). The obtained resin layer is the general curing condition for existing centrifugal reinforced concrete pipes.
It can be sufficiently cured at -80 ° C for 1 to 4 hours.
This resin layer has a solid content concentration and a viscosity of about 0.05 to 0.3 mm in one injection of the copolymer emulsion according to the present invention.
Since the thickness can be obtained, it is possible to obtain a desired thickness by adding it in several times as necessary. The final thickness of the resin layer after curing is preferably in the range of 0.1 to 3 mm, more preferably 0.3 to 1 mm. Thickness is 0.1
If the thickness is less than 3 mm, pinholes are likely to occur, and the sulfuric acid aqueous solution may soak in, corroding the concrete layer or the intermediate layer. If the thickness exceeds 3 mm, the effect will reach the ceiling and
This results in an increase in manufacturing cost due to an increase in the number of times the copolymer emulsion according to the present invention is charged, and an increase in raw material cost due to an increase in the amount of resin used.

On the other hand, for forming a resin mortar layer using the copolymer emulsion according to the present invention and fine aggregates, fine aggregates such as river sand, silica sand, cold water sand, shirasu balloon, glass fiber, and ceramic pipe are used.・ Inorganic aggregates such as FRPM pipes (reinforced plastic pipes), polymer cement concrete, fine aggregates used in resin concrete, etc., such as ceramic crushed powder for roof tiles and pottery, synthetic resin powder, crushed synthetic resin, etc. It is possible to use the organic aggregate of the above. The fine aggregate has a particle diameter of 1/3 to 1/4 or less of the thickness of the resin mortar layer. The advantage of the anticorrosion lining by the resin mortar layer is that the price per unit weight can be lowered by blending the inexpensive fine aggregate, and therefore the anticorrosion lining layer can be made thicker, so The point is that greater resistance is imparted than the lining by the polymer emulsion alone.

In the preparation of the resin mortar, it is preferable to add 500 parts by weight or less of the fine aggregate to 100 parts by weight of the solid content of the copolymer emulsion according to the present invention, and more preferably 300 parts by weight or less. It is advisable to add water appropriately according to this blending amount to obtain a viscosity suitable for the work. Fine aggregate
If it exceeds 500 parts by weight, the proportion of the copolymer is reduced and micropores are generated, so that the sulfuric acid content easily penetrates into the resin mortar layer. The thickness of the resin mortar layer after curing is preferably thicker than the resin layer using only the above-mentioned copolymer emulsion according to the amount of the aggregate compounded, and is 5 mm at maximum, more preferably 2 to 3 mm or less. And can be arbitrarily selected according to the size of the aggregate. This resin mortar layer can also be subjected to centrifugal force coating (high speed rotation of 30 to 50 G for 3 to 5 minutes) to cure the concrete pipe simultaneously with steam curing.

For the formation of the intermediate layer, resin cement mortar in which cement and inorganic aggregate are mixed with the copolymer emulsion is used. This cement includes Portland cement, alumina cement, hydraulic cement,
Examples of natural cement include inorganic aggregates such as various natural and artificial aggregates such as sand, asbestos, and talc. If necessary, known gypsum, calcined gypsum, calcium chloride, magnesium oxychloride, etc. may be used in combination therewith. The amount of copolymer emulsion used in resin cement mortar is 100 parts by weight of cement,
The solid content of the copolymer emulsion is preferably 5 to 45 parts by weight. When the amount of the inorganic aggregate used is too small, the volume change due to drying shrinkage of the resin cement mortar layer is large, which causes cracks and the like. On the contrary, when the amount is too large, a mechanically fragile intermediate layer is formed. Therefore, although it is selected from the range of 50 to 900 parts by weight with respect to 100 parts by weight of cement, it is generally more preferable to set it to 200 to 300 parts by weight. The method of mixing these is not particularly limited, and it is sufficient to simply knead cement, sand, polymer emulsion, water, etc., but if necessary, some additives, for example (especially low molecular weight) surfactant , Plasticizer, pigment,
You may add a solvent etc.

In the resin cement mortar, after the base material cement concrete layer is compacted, the squeezed water is discharged in the same manner as in the centrifugal reinforced concrete pipe manufacturing process, and the base material cement cocrete layer is uncured. Then, it is put into the inner surface of the base material concrete pipe and is lined by centrifugal force. The lining conditions may be almost the same as the forming conditions of the base material concrete, and the low speed rotation of 3 to 5 G × 3 to
Make the input material uniform in 5 minutes and rotate at a medium speed of 10 to 15G.
After the material is laterally moved in 3 minutes, it is compacted by high speed rotation of 30 to 50 G for 1 to 2 minutes to form an intermediate layer. The intermediate layer is composed of a copolymer, cement and an inorganic aggregate, and the centrifugal lining increases the distribution density of the copolymer phase having a specific gravity smaller than that of the cement phase on the inner surface side of the pipe in the intermediate layer. The composition provides higher adhesion, but if this layer is too thin, a well-defined graded composition will be difficult to distinguish. In addition, the inorganic aggregate used for this needs to be sieved to a grain size of 1/3 to 1/4 or less of the thickness of the intermediate layer, and if the intermediate layer is too thin, the rough surface of the base material concrete pipe Causes a drawback that it cannot be erased sufficiently. Further, if the expensive intermediate layer is too thick compared to the base material concrete layer, it is disadvantageous in terms of cost, so the thickness of the intermediate layer after curing is preferably 0.5 to 15 mm, more preferably 1 to
5 mm. By the way, the particle size of the aggregate is 0.15 mm according to JIS,
It is defined as 0.3mm, 0.6mm, 1.2mm, 2.5mm, 5.0mm. When the thickness of the intermediate layer is 5mm, the aggregate with a grain size of 1.2mm or less and the thickness of the intermediate layer is 2mm. If the particle size is 0.6mm
The following aggregates must be screened and used.

The copolymer according to the present invention has an alkoxysilyl group, which can be stabilized in water as described above and crosslinks during film formation due to evaporation of water to provide toughness and abrasion resistance. Contributes to the formation of the film that it has, and also to the improvement of the adhesiveness because the alkoxysilyl group and the silanol group that is its hydrolyzate react with the cement phase composed of silicate or silica sand and the silanol group on the aggregate surface. To do. Due to these characteristics, the anticorrosion concrete pipe is provided which is free from peeling and cracking of the anticorrosion lining layer, and does not drop out of fine aggregate, and which has extremely excellent acid water blocking property and durability.

[0025]

Next, the present invention will be specifically described based on examples and comparative examples, but the present invention is not limited to the description of the examples. In the examples, parts and% indicate parts by weight and% by weight, respectively.

Example 1 A polymerization vessel equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet was charged with 100 parts of deionized water and 0.03 part of sodium carbonate as a pH buffer and 0.3 part of boric acid, and the mixture was stirred with stirring. After raising the temperature to ℃, it was replaced with nitrogen. Add 0.15 parts of Rongalit and 1 part of disodium ethylenediaminetetraacetate.
% Aqueous solution 0.08 part, 1% ferric sulfate aqueous solution 0.04 part, and at the same time, γ-methacryloxypropyltriethoxysilane 2 parts, n-butyl acrylate 47 parts, methyl methacrylate 50 parts, and 2-hydroxymethacrylate. Ethyl 1
Part, reactive surfactant represented by the following structural formula, Aqualon RN-20 (trade name of Dai-ichi Kogyo Seiyaku Co., Ltd.) 3.2 parts, Aqualon HS-10 (trade name of Dai-ichi Kogyo Seiyaku Co., Ltd.) 1.4 parts and t-
104.9 parts of a mixed solution of 0.3 part of butyl hydroperoxide (69% of pure content) was uniformly added with stirring for 3 hours while maintaining the internal temperature at 60 ° C, and further reacted at 60 ° C for 1 hour to carry out polymerization. finished. Next, the inside of the vessel was cooled to 30 ° C., and 5 parts of nonion HS-240 (trade name of polyoxyethylene octylphenyl ether manufactured by NOF CORPORATION) and KM-681 were used.
FA (Shin-Etsu Chemical Co., Ltd. product name, silicone defoamer)
Add 1 part, adjust the pH to 8.5 with caustic soda, and at room temperature
Aged for 24 hours. The obtained copolymer emulsion has a solid content concentration of 50.5%, and the glass transition temperature of the copolymer is
It was 6.7 ° C.

[0027]

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On the other hand, a unit cement amount of 450 kg / m ³ , a water cement ratio of 40%, a mixture of 100 parts of ordinary Portland cement, 300 parts of coarse aggregate and 100 parts of fine aggregate, a hardened cement, an inner diameter of 306 mm and a length of 350 mm. Put it in the rotating formwork of 15
0 rpm (4 G) x 3 minutes → 265 rpm (12 G) x 2 minutes → 480 rpm
It was compacted under the condition of (40 G) × 1 minute, and the squeezed water was discharged to produce a concrete pipe having an inner diameter of 250 mm, a thickness of 28 mm, and a length of 350 mm. Next, this concrete pipe was left uncured, and on its inner surface, the above copolymer emulsion was used, and 200 parts per 100 parts of the solid content of No. 6 silica sand for casting (JIS G 590
1) was blended and tap water was added so that the total solid content would be 40%, and the resin mortar was added in an amount of 15.8 kg / m ² , and centrifugal force was applied under the conditions of 480 rpm (40 G) x 3 minutes. The inner surface was coated with a lining to form a resin mortar layer, which was used as an anticorrosion lining layer. After that, steam curing was carried out under the conditions of 80 ° C. × 2 hours and room temperature for 14 days.

This concrete pipe was cut into curved plate-shaped test pieces each having a length of 100 mm and a circumference of 100 mm, and the thickness of the resin mortar layer was measured to be about 3 mm.
mm. The remaining 5 surfaces of the test piece, on which the anticorrosion lining layer was not formed, were brushed with the above copolymer emulsion to form a 0.5 to 0.6 mm resin layer having no pinhole. After that, the acid resistance, the adhesiveness, and the abrasion resistance of the anticorrosion lining layer were measured, and the film-forming property of the copolymer emulsion was measured. The results shown in Table 1 were obtained. In addition, the measurement of each characteristic was performed as follows.

A. The acid resistant test piece was immersed in a 10% H ₂ SO ₄ aqueous solution at 50 ° C. for 28 hours, and the surface condition was observed and evaluated according to the following criteria. A: no erosion, B: partially eroded, C: almost eroded b. Adhesive Use a knife on the surface of the anticorrosion layer to make 5 vertical and 5 horizontal cuts in each side and 24mm in that area.
A gum tape having a width was adhered, and the surface condition when strongly peeled was observed and evaluated according to the following criteria. A: No peeling, B: Partial peeling, C: Most peeling c. Abrasion resistance After immersing the test piece in warm water at 50 ℃ for 7 days, JIS A 6909
The test was performed according to the abrasion test method of 5.16, and evaluated according to the following criteria. A: no peeling, B: partial peeling, C: almost peeling d. The emulsion was applied to a film-forming glass plate so as to obtain a thickness of 0.15 mm, and dried in a dryer at 80 ° C. for 5 minutes. The film-forming property of the obtained film was visually observed. A: A continuous film is formed, B: A discontinuous film is partially present,
C: Discontinuous film on the entire surface

Examples 2 to 6 and Comparative Examples 1 to 5 Copolymer emulsions were prepared in the same manner as in Example 1 using the types and amounts of monomers and surfactants shown in Table 1 or Table 2. , Manufactured concrete pipes. The properties of the obtained concrete pipe were evaluated in the same manner, and the results are shown in Table 1 or Table 2. The surfactants used are as follows. Aqualon RN-20 (above), Aqualon HS-10 (above), Emar O (sodium lauryl sulfate,
Kao company's product name), Nonipol 400 (polyoxyethylene nonyl phenyl ether Sanyo Chemical Co., Ltd. product name)

[0032]

[Table 1]

[0033]

[Table 2]

Example 7 The inner surface of an uncured concrete pipe obtained in the same manner as in Example 1 had a water cement ratio of 35% and a resin cement ratio of 20%. Size
Resin cement mortar in which 300 parts of 1.2 mm) and 20 parts of the emulsion obtained in Example 1 as a solid content were mixed,
Add only the amount that becomes kg / m ² , 150 rpm (4G) × 3 minutes → 26
It was compacted under the conditions of 5 rpm (12 G) × 2 minutes → 480 rpm (40 G) × 1 minute, and excess water was discharged to form a resin cement mortar layer having a thickness of 5 mm. Further on, Nonion HS-2
The emulsion prepared in the same manner as in Example 1 except that 40 was not added was added to the inner surface of the tube in an amount of 0.79 kg / m ² to coat the inner surface under the conditions of 480 rpm (40 G) × 1 minute. Then, the same amount was added, the inner surface was coated under the same conditions to form a resin layer, and the same steam curing and room temperature curing as in Example 1 were performed. This concrete pipe was cut to prepare a test piece similar to that of Example 1, and the thickness of the resin layer was measured and found to be about 0.3 mm. Copolymer emulsion was applied to the remaining 5 surfaces of the test piece on which the resin layer was not formed to form a resin layer by the same method as in Example 1, and the same measurement was carried out. The adhesiveness was A.

Example 8 Instead of the copolymer emulsion used for forming the resin cement mortar layer in Example 7, VINYBLAN 705 (trade name, manufactured by Nissin Chemical Industry Co., Ltd., vinyl chloride / acrylic acid ester type copolymer emulsion) ) Was used to form a resin cement mortar layer, and a concrete pipe was prepared in the same manner, and the same measurement was carried out. The acid resistance was A and the adhesiveness was A.

Example 9 The copolymer emulsion obtained in Example 1 was applied to the inner surface of an uncured resin-cement mortar layer of a concrete pipe obtained in the same manner as in Example 7 to obtain 200 parts per 100 parts of solid content. Mixing No. 6 silica sand (JIS G 5901) for molds, the total solid content is
A resin mortar containing 40% of tap water was used to form an anticorrosion lining layer in the same manner as in Example 1,
When the same measurement was performed, the acid resistance was A, the adhesiveness was A,
The abrasion resistance was A.

Example 10 In place of the copolymer emulsion used for forming the resin cement mortar layer in Example 9, Vinibran 2622 (trade name of Nisshin Chemical Industry Co., Ltd., acrylic ester emulsion)
When a concrete pipe was prepared in the same manner as above except that the resin cement mortar layer was formed using the above, the same measurement was carried out. The acid resistance was A, the adhesiveness was A, and the abrasion resistance was A.

[0038]

INDUSTRIAL APPLICABILITY According to the present invention, as a resin constituting an acid resistant resin layer or a resin mortar layer which is an anticorrosion lining layer, a resin having excellent water resistance and acid resistance and having a hydrolyzable alkoxysilyl group is used. By using a polymer, the alkoxysilyl group is crosslinked to form a crosslinked resin having toughness and wear resistance, and since the alkoxysilyl group and its hydrolyzable group also react with the cement phase and aggregate,
Since the anticorrosion lining layer has extremely excellent adhesiveness, durability and water impermeability, it is possible to provide a reinforced concrete pipe which is particularly useful as a sewer pipe in which the problem of corrosion due to hydrogen sulfide and microorganisms is serious.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C09D 157/00 PDC C09D 157/00 PDC F16L 9/08 F16L 9/08 // B28B 21/94 B28B 21/94 (72) Inventor Shuichiro Shinohara 2-17-33 Kitafu, Takefu City, Fukui Prefecture Nisshinka Gaku Kogyo Co., Ltd. (72) Inventor Akio Nakamura 1-406 1 Yoshino-cho, Omiya-shi, Saitama Shin-Etsu Polymer Inside the Product Laboratory Co., Ltd. (72) Hiroshi Matsumoto 1-406-1 Yoshino-cho, Omiya City, Saitama Prefecture Shin-Etsu Polymer Co., Ltd. Inside the Product Research Center (72) Tsutomu Saga 1-406-1 Yoshino-cho, Omiya City, Saitama Prefecture Yue Polymer Co., Ltd. Product Research Center

Claims (1)

[Claims] 1. On the inner surface of the concrete layer, (a) the general formula R ¹ R ² _(3-n) SiX _n (wherein R ¹ is a monovalent organic group having a polymerizable double bond, R ² is the number of carbon atoms). 1 to 4 alkyl groups, X is an alkoxyl group having 1 to 4 carbon atoms, and n is an integer of 1 to 3) 1 to 20% by weight of an alkoxysilyl group-containing monomer, and (b) the above ( Anticorrosion lining containing a copolymer having a glass transition temperature of −35 to 50 ° C. obtained by emulsion copolymerizing a monomer mixture consisting of 80 to 99% by weight of a) Anticorrosion concrete pipe characterized by having layers.