KR101025639B1 - Method for producing a medium-temperature water-curable epoxy resin coating composition for lining the internal water and sewage pipe. - Google Patents

Abstract

Water and sewage pipes are used to transfer water, and most of the pipelines are buried underground, so it is easy to have water remaining inside the pipelines or rainwater flowing in during the laying of steel pipes or renovation of old pipes. However, the residual water inflow is concentrated in the pipeline due to the gradient of the pipeline, so it is difficult to completely drain the water, and dew condensation occurs frequently on the inner surface of the pipeline because the air is not well communicated and the moisture is not completely removed. Lining construction to prevent corrosion on the surface to be coated in the above environment is because the coating film is not bonded by the moisture of the surface to be coated with the hardened coating film of the paint on the surface of the steel pipe or concrete fume pipe can not achieve the purpose of preventing corrosion. The problem is solved by a method of manufacturing an underwater curable epoxy resin composition composed of a material having a function of exerting adhesion even in water and wet surfaces in which water in water and sewage pipes exist.

Description

Resin composition and method for producing, the middle temperature forwater-curing epoxy resin, for water and sewage pipe.}

The present invention is the epoxy resin coating material for the construction of new pipes for the construction of water pipes for industrial water and agricultural water pipes and concrete fume pipes of sewage pipes and renovation of old pipes is hardened in the wet surface and water of the painted surface, The present invention relates to a method for preparing a composition of an underwater curing type epoxy resin coating material having excellent adhesion in the wet state and the water surface of a steel pipe or concrete surface, thereby achieving the purpose of preventing corrosion of steel pipes and leakage of concrete pipes. Water and sewage pipes are mainly made of inorganic materials such as iron and concrete, so the surface is hydrophilic and has a large polarity. Moreover, wetting is large due to moisture, so it becomes wet. No adhesion on moisture Therefore, the method of producing a large amount of the hydroxyl group (-OH), which is a hydrophilic group generated during the curing process of the hydrophobic epoxy resin composition, and the composition of the hydrophobic epoxy resin-based composition by mixing a polar material with excellent wettability, wetting It is a technology of the structure that improves the adhesive strength by increasing the hydrogen bonding density by hydrogen bonding with the polar group on the surface of the inorganic material in the cotton state.

In general, the conventional method of the epoxy resin in water-curable epoxy resin composition by adding a long carbon chain amine, such as stearylamine with excellent wettability and the ability to replace the water at the interface to the curing agent of the epoxy resin as an additive The amine (Amin) in the epoxy resin composition wets the metal surface preferentially and replaces it with water, and the epoxy resin composition blended using an excessive amount of polyamide (polyamide), which is a kind of hardener component, functions as described above. The method of substituting with water is mainly used. Since the conventional method of the present invention imparts a water substitution ability only to the curing agent in the epoxy resin material consisting of the main agent and the curing agent, the water at the interface of the coating surface can be removed to some extent by the substitution ability of the epoxy resin coating material. Although it is possible to completely remove moisture harmful to the adhesion of the coating film, the adhesive strength is lowered compared to the coating surface is cured in the dry state of the coating surface, and the excess amine is used to increase the water substitution ability. Since the physical strength and chemical resistance of the cured coating film of the epoxy resin is lowered and the excess amine is eluted, there is a disadvantage that it cannot be used as an epoxy resin for water supply. Since the inside of the sewage and sewer pipes are always in the water, the coating film of the water and sewage pipes must achieve the purpose of long-term corrosion prevention and leakage prevention with strong adhesive force.

In general, epoxy resins are resins used as base resins, which have epoxy groups at both ends of the central molecular skeleton, and the main components of the central molecular skeleton are bisphenol A, bisphenol F, or novolac phenol resins, and both ends. It is generally used that the epoxy group of the group is made of glycidyl ether (CH ₂ · O · CH ₂ —CH ₂ —CH ₂ —O—R). The epoxy resin of bisphenol A diglycidyl ether resin or bisphenol F diglycidyl ether has two epoxy groups at both ends, so that the amine groups of the polyamine or polyamide in which the epoxy groups at both ends are used as a curing agent (NH ₂ -R-NH ₂ The epoxy group of the epoxy resin is ring-opened by reacting with active hydrogen of), and the curing reaction of the epoxy resin proceeds to form a three-dimensional network molecule.

The reaction formula of the epoxy group of an epoxy resin and the amine of a hardening | curing agent is as follows.

R-NH ₂ + CH ₂ · O-CH-R´ → R-NH-CH ₂ -CH

R-NH-CH ₂ -CH.OH.-R '+ CH ₂ -O.CH-R'

→ R'· OH · CH - CH 2 - NR - CH 2 - CH · OH · ~R˝

In the above reaction, the ring-opening reaction of the epoxy group generates a hydroxyl group (R-OH) that enhances the adhesion to the surface of the object, and expresses strong adhesion to the surface of the object.

However, when the epoxy resin paint is in water or wet surface, the presence of water between the coated object and the epoxy resin paint lowers the adhesion to the adhesive interface. The method of substituting moisture after making the surface wet with the hardening | curing agent excellent in wettability is taken. Conventional methods like this add a long-chain aliphatic amine, such as stearylamine, to the hardener of the paint, whereby the amine preferentially wets the surface of metals and inorganics and gradually replaces it with water. Substituted water is emulsified inside the coating layer, dispersed in the coating film, and finally, evaporated and cured in the coating film, and another conventional method uses a polyamide curing agent that is insoluble in water, about less than the theoretical amount of epoxy resin. By mixing 15 ~ 50 wt% of excess, the excess amount of polyamide until the epoxy resin is cured in water becomes larger than the affinity for the coated surface. Substitute water molecules.

As such, the cured product using an excessive amount of polyamide (Poly Amide) has a lower physical strength, chemical resistance, and water resistance when comparing the cured coating performance of a composition in which the main epoxy resin equivalent and the amine equivalent of the curing agent are quantitatively designed. There is a disadvantage in that amines which should not be eluted from the coating film for tap water are eluted. In the conventional method as described above, although the water replacement of the surface to be coated is made to some extent, the adhesive strength is lowered compared to the coating film of the epoxy resin coating material on the surface of the dry surface to be used for the water and sewage pipes to be used in the present invention. It has a disadvantage that it can not be used for long-term corrosion protection purposes and leak prevention of concrete pipes.

Since conventional epoxy resins used are bisphenol A-based or bisphenol F-based diglycidyl ether type epoxy resins, the average number of epoxy groups in these resins is 1.95 per molecule, resulting in ring opening reaction of epoxy groups. There are 1.95 hydroxyl groups.

Since the adhesive strength of the epoxy resin film decreases in water or on the wet side, in order to improve the adhesive force, it is necessary to increase the adhesion strength by increasing the density of hydrogen bonds capable of forming a strong hydrogen bond by designing a large amount of epoxy groups in one molecule. Since the conventional water curable epoxy resin mainly uses bisphenol A epoxy resin, it is not suitable as the water curable epoxy resin for water and sewage to be used in the present invention.

Water and sewage pipes are in a state of being deposited in water for long periods of time when water is passed, and in particular, sulfuric acid is generated and discharged from sewage by bacterial bacteria in sewage pipes. Can be achieved. The present invention exhibits strong adhesive strength even when the steel and concrete surfaces of the inorganic material are in the water or wet surface state, and can be easily impregnated into the material of Fiber Reinforce plastic, and also prevent the paint flow from the vertical coating surface. Invented a base resin composition with a large surface polarity that can be controlled and has affinity with water by introducing a polar group, and can be cured at room temperature according to the choice of curing agent. An object of the invention is to invent a composition of a mesophilic curing agent which can be cured at ℃.

In order to achieve the above object, the present invention does not use a bisphenol A or F type epoxy resin having an average of 1.95 epoxy groups in one molecule of epoxy resin, and has an average number of 3.3 epoxy groups in one molecule of epoxy resin. Epoxy resins of volacic glycidyl ether or allocresol novolac type glycidyl ether (hereinafter referred to as novolac epoxy resins) are used. Novolak-type epoxy resins are mainly semi-solid or solid materials. The softening point is about 50 ~ 95 ℃, so it is a low-viscosity liquid aliphatic resin to dissolve the novolac-type epoxy resin, and 3 or more epoxy groups are present in 1 molecule. It is mixed and dissolved with trimethylol floppan triglyceryl ether resin to give a base resin of odorless epoxy resin composition. The above theme is that some components of trimethylolfurophan trigrisidyl ether have a slightly soluble polarity and are mixed with a novolak type epoxy resin which is insoluble in hydrophobic water so that the composition is insoluble in water but is resinous. Wetting is first given to the coated surface of the wet surface by the polar group of. The curing agent modifies the polyamine (Poly Amin) to invent a room temperature curing type hydrocuring agent and a medium temperature curing type hydrocuring agent. The room temperature curing type hydrocuring agent is a mixture of lauryl glycidyl ether and trimethylol furophan triglycidyl ether having a long carbon chain in a mixed solution of diethanolamine added to either dieethylene triamine or triethylenetetramine. The reaction was carried out to pre-react a portion of the active hydrogens in diethylene triamine or triethylenetetramine to further synthesize the hydroxyl group (-OH) produced in this reaction, the hydroxyl group (-OH) of diethanolamine and the long carbon chain of lauryl. It is synthesized by the modified adducter of polyamine. Since the curing agent has a property of increasing molecular weight and does not dissolve in water, and has a large amount of a hydroxyl group (-OH), which is a hydrophilic group, the curing agent has affinity for the coated surface of the wet surface. Wetting occurs.

The mesophilic curing agent is reacted with a mixture of tetraethylenepentaamine and diethanolamine with a mixture of trimethylolfurophane triglycidyl ether and lauryl glycidyl ether to give active hydrogen and diethanolamine in the amine group of triethylenepentamine. A pre-reacted part of the active hydrogen is synthesized to synthesize a polyamine modified by addition of a large number of hydroxyl groups (-OH) and lauryl long carbon chain produced in this reaction. In this way, the synthesized room temperature curing agent and the medium temperature curing agent are very large in molecular weight, so that the solubility in water is very low, and the hydrophilic group (-OH), which is produced, has an affinity for wet coating surfaces. The preferential wetting on the surface to be coated is facilitated, and the ability to absorb and replace the moisture on the surface to be coated is generated. In addition, increasing the number of active hydrogens of tetraethylenepentamine further increases the preliminary reaction, thereby increasing the gel time when the main agent and the curing agent are mixed.

Base Resin, which is a mixture of a novolak-type epoxy resin and trimethylol furophane triglyceridyl ether, prepared as described above, has a conventional number of bisphenol-based diglycidyl ethers of epoxy groups in one molecule of epoxy resin solution. Compared to the bisphenol-based diglycidyl ether series, the amount of curing agent is increased. Therefore, the composition of the whole epoxy resin is very polar, so that it is possible to use additives such as stearamine. There is no need to use excess hardener. Since the ratio of the main body and the curing agent of the above-mentioned water-curable composition is used in a ratio of 70-110 parts by weight based on 100 parts by weight of the main body, the amount of the modified polyamine having a large number of hydrophilic groups is increased at the initial stage of coating of the epoxy resin for water curing. Wetting occurs on the wet surface of the surface to be coated, and as the hydrogen bonding density increases due to the substitution of water and the formation of many hydroxyl groups in the process of hardening, strong adhesion occurs.

Such water-curable epoxy resin paints not only increase the water substitution capacity of the coated surface of water or wet surface, but also the physical properties of the cured product of the epoxy resin paint are optimal because the mixed equivalent ratio of the main material and the curing agent is quantitatively equal to the theoretical amount. The physical strength, chemical resistance, and water resistance of the cured coating film of epoxy resin are excellent, and it is suitable as a coating material for water supply, and in the case of increase of hydrogen bond density with the surface to be coated and heat curing in the case of medium temperature curing, As a result of dehydration, some of the hydrogen bonds form a covalent bond structure, resulting in a stronger adhesion and physical strength. The composition using the medium temperature curing type hydrocuring agent having such a composition not only has a long gel time, but also a hardening time by heating has a property of rapidly progressing due to the high activity of the main epoxy, so the hardening time is shortened to improve workability. have. Hereinafter, the present invention will be described in detail. The composition of the present invention is a novolak-type epoxy resin 20% to 60% by weight of 20% to 60% trimethylol purophane triglycidyl ether resin 80 to 40% by mixing according to the viscosity to adjust the temperature and about 60 ~ 90 It is heated to ℃, stirred, cooled to make a homogeneous solution, and made into a water-curable epoxy resin. According to the purpose of using a hardening | curing agent composition, a composition is invented as a room temperature hardening type water hardener and a medium temperature hardening type water hardener. The room temperature curing type hydrocuring agent is any one of 103 parts by weight of diethylene triamine or 146 parts by weight of triethylene tetraamine and 50 to 70 parts by weight of diethanolamine in a reactor with a cooling jacket and a heating coil, and the temperature is increased to 80 to 90 ° C. After heating, the mixture was mixed with 5-10 parts by weight of trimethylolfurophane triglyceridyl ether and 360-411 parts by weight of laugricidyl ether at 110 ° C. or lower for 2 hours and then 110 ° -120 ° C. for 2 hours. After the reaction, the mixture is cooled and mixed with 30 to 50 parts by weight of 2,4,6 trisdimethylmethyl methyl phenol as a curing accelerator to obtain a room temperature curing type hydrocuring agent. Mid-temperature curing type hydrocuring agent is 190 parts by weight of tetraethylene pentamine and 50 to 70 parts by weight of diethanolamine are put in a reactor with a cooling jacket and a heating coil, and heated to 80-90 ° C., and trimethylolpurophan trigrisidyl ether 10 to 15 parts by weight of lauryl-glycidyl ether 400 ~ 480 parts by weight of the mixture is dropped at 110 ℃ or less for 3 hours, the temperature is reacted at 110 ~ 120 ℃ for 2 hours and then cooled to 2.4.6 tris 30-50 weight part of dimethylaminomethyl phenol is mixed and stirred, and it is set as a moderate temperature hardening type water hardening agent. The mixing ratio of the main ingredient and the curing agent thus prepared calculates the average epoxy equivalent weight of the main ingredient, and the curing agent calculates the amine equivalent weight of the modified polyamine of the synthesized normal temperature curing agent or medium temperature curing agent, and the amine equivalent is the epoxy equivalent. The number obtained by multiplying the value divided by 100 is used as the curing agent mixing amount, and the mixing amount is the weight part of the curing agent with respect to 100 parts by weight of the main body.

As described above, according to the present invention, an excessive curing agent is not used to replace the water at the interface between the surface to be coated and the water-curable epoxy resin paint, and not only replaces water but also improves the adhesion of the surface to be coated with water and sewage pipes. As a result, the water-retaining performance of the pipeline constantly dipped in water was improved.

Specific contents of the present invention was prepared by the composition of the present invention as shown in the following table. Table 1 is the composition of the water-curable epoxy resin motif, Table 2 is a room temperature curing type hydrocuring agent composition, Table 3 is a medium temperature curing type hydrocuring agent composition, the present invention is not limited by the examples.

Underwater curing type epoxy resin main composition (wt%) Product Name product name Compounding cost Epoxy equivalent (g / eq) Novolac Epoxy Resin YDPN631 (Kukdo Chemical) 40 165 Trimethylolfurophane Triglyceridyl Ether YH-300 (Kukdo Chemical) 60 135 -Epoxy equivalent: 145.7-Viscosity (Gardner 20 ℃): Y

Room temperature curing type hydrocuring agent composition (parts by weight) Product Name Compounding cost Active hydrogen water Molecular Weight Triethylene tetramine 146 6 146.23 Trimethylol Furophane Trigrisidil Etel 5 - 302.36 Lauryl Grisidil Etel 360 - 242 2.4.6 Tris Dimethyl Amino Methylphenol 25 - - Diethanolamine 60 One 105.1 -Amine equivalent: 103.8

Medium temperature curing type water curing agent composition (parts by weight) Product Name Compounding cost Active hydrogen water Molecular Weight Tetra ethylene penta
Min 190 7 189.31 Diethanolamine 50 One 105.1 Trimethylol Furophane
Triglycidyl ether 10 - 302.36 Lauryl Grisidil etel 400 - 242 2.4.6 Tris Dimethyl
Diamino methylphenol 35 - - -Amine equivalent: 130

The main composition of the water curable epoxy resin composition for water and sewage prepared as described above, the amount of the curing agent and the performance of the cured product are shown in Table 4 below.

Item Room temperature curing type water curing epoxy Mid-temperature curing underwater curing epoxy subject
100 parts by weight Hardener
70 parts by weight subject
100 parts by weight Hardener
90 parts by weight Gel Time (150g, 25 ℃) 2 hours 45 hours Gel Time (150g, 2 ℃) 2 days 3 days Curing time (20 ℃) 24 hours - Curing Time (70 ℃, OVEN) 15 minutes 60 minutes Adhesiveness (25/25 5mm each) 25/25 25/25

for
Exodus
city
Hum flavor clear clear smell clear clear Turbidity 0.5 or less 0.5 or less Permanganese Potassium Consumption 0.8 0.9 Residual Chlorine Reduction 0.3 0.3 Phenols Not detected Not detected Cyan Not detected Not detected Amines Not detected Not detected Epichlorohydrin Not detected Not detected Toluene diisocyanate Not detected Not detected

The dissolution test item whose cured coating performance of the water-curable epoxy resin composition for water and sewage pipes of the above embodiment was a prerequisite for water supply resulted in conformity with the standards of KS D 8502, and was satisfactory in adhesion to water and wet surfaces. Was evaluated.

Claims (2)

The main composition is mixed and adjusted according to the viscosity to be used at 20 to 60% by weight of the novolak-type epoxy resin and 80 to 40% by weight of trimethylol furophane triglyceridyl ether resin, and the temperature is heated to about 60 to 90 ° C. Stirring and cooling to make a uniform solution, based on water-curable epoxy resin;
The medium temperature curing type hydrocuring agent is 190 parts by weight of tetraethylenepentamine and 50 to 70 parts by weight of diethanolamine in a reactor with a cooling jacket and a heating coil, and heated to 80-90 ° C. 10 to 15 parts by weight of lauryl-glycidyl ether 400 ~ 480 parts by weight of the mixture is dropped at 110 ℃ or less for 3 hours, the temperature is reacted at 110 ~ 120 ℃ for 2 hours and then cooled to 2.4.6 tris 30-50 parts by weight of dimethylaminomethylphenol is mixed and stirred to prepare a medium temperature curing type water-based curing agent;
The medium-temperature curing type water-curable epoxy resin is used by mixing the main body of water-based epoxy resin and the medium-temperature-curing water-based curing agent. Method for producing a medium-temperature water-curable epoxy resin coating composition for lining the internal water and sewage pipe, characterized in that it is used. delete