KR101221321B1 - A polyurea resin paint composition for coating of steel pipes and its preparation process - Google Patents

Abstract

PURPOSE: A polyurea resin composition is provided to have excellent physical properties and chemical properties and to have excellent resistance to cathode separation. CONSTITUTION: A polyurea resin composition comprises 40-60 weight% of a base part and 40-60 weight% of a hardening agent part. The base part contains a polymerization inhibitor and an urethane prepolymer which is generated by polymerizing diisocyanate, polyoxyalkylene glycol, and alkylene carbonate. The hardening part contains polyether amine, a wetting dispersant, a pigment, a chain extender, an adhesion enhancer, a defoamer, and a flowability controller.

Description

Polyurea resin coating composition for internal and external coating of steel pipes and its manufacturing method {A POLYUREA RESIN PAINT COMPOSITION FOR COATING OF STEEL PIPES AND ITS PREPARATION PROCESS}

The present invention relates to a polyurea resin coating composition for internal and external coating of steel pipes and a method of manufacturing the same, and more particularly to diisocyanate, polyoxyalkylene glycol, and alkylene carbonate. Part of the curing agent containing a polyetheramine, a wet dispersant, a pigment, a chain extender, an adhesion enhancer, an antifoaming agent, and a fluidity control agent to the main portion containing the urethane prepolymer produced by the polymerization reaction of In the case of preparing a polyurea resin coating composition by mixing, a polymerization inhibitor (Polymerization inhibitor) is added to the main portion to terminate the polymerization reaction of the urethane prepolymer by preventing the increase of viscosity or gelation due to the reaction of unreacted isocyanate. This improves long-term storage stability, as well as improving physical and chemical properties. Polyurea resin coating composition for environmentally-friendly steel pipe coating and its manufacturing method that can be applied to water, sewage, general water and other underground pipes such as steel pipes used for transporting fluids. It is about.

In general, steel pipes used for city gas, water supply, sewage, and various fluid transportation include a polyethylene coating layer on the outer surface, and a coating layer containing inorganic, epoxy, polyurethane, and polyurea as the main components on the inner surface thereof. It prevents damage to the product from being generated or from external shocks.

The paint coated on the inside or outside of the steel pipe has high pressure, heat, chemical reaction, etc., so it must satisfy the characteristics such as water resistance, corrosion resistance, durability, bending resistance, impact resistance, abrasion resistance, and chemical resistance, and also meets drinking water standards. In the case of the coating method using inorganic and epoxy resins, there is a disadvantage in that the curing speed is slow and humans need to work directly, and there is a fear of cracking of the coating due to poor durability, impact resistance and cold resistance. This may cause clogging inside the pipe. In addition, in the case of the coating method using only epoxy resin, it is necessary to apply heat because curing is slow, and bisphenol A, which is contained in the coating material for internal coating, may remain harmful to the human body. In addition, the impact resistance and the bending resistance are weak, so there is a high possibility of damage due to impact or partial peeling at the bent portion.

On the other hand, in the case of the coating method using polyurethane, the adhesion of the paint is good, but there is a possibility that the coating film is foamed because the curing speed is generally slow and sensitive to humidity, whereas in the case of the coating method using polyurea, It is stable to humidity, but the curing speed is too fast, so the airtightness and adhesion with material are low, and the specific gravity is low because it does not use extender pigments (calcium carbonate, barium sulfate, silica, etc.), and it is sprayed under high temperature and high pressure. In this case, a lot of dust is generated.

Accordingly, the development of paints suitable for the internal and external coating of steel pipes is steadily required, but the current pipe condition of our country is very poor compared to the developed countries, in particular, the coating material for the internal coating of water pipes is durable, water resistance, corrosion resistance In addition to poor chemical resistance, adhesion and wear resistance, there is a problem that it is difficult to form a uniform coating film.

Actually, since the binding of the coating agent to the steel pipe has various variables such as the roughness of the bonding surface or the plastic deformation of the coating agent, it is difficult to explain the adhesion and durability of the coating agent simply by physical or chemical adhesion. In order to prevent corrosion of water pipes and sewage pipes and to prevent contamination, they have been treated with a coating using epoxy resin.

As such, in order to prevent corrosion of water and sewage pipes and to prevent contamination, the film has been mainly treated with epoxy resins in Korea, but in recent years, epoxy resins contain many harmful substances and have many side effects when used as water pipes. It is known that there is a lot of effort in the development of paint using polyurethane or polyurea.

In spite of such efforts, the polyurethane paint is difficult to be practical due to the poor adhesion and uneven reactivity, but recently, the practical use of the adhesive strength is about 1200psi maximum. In addition, in order to increase the physical adhesive strength of the coating agent, the surface of the steel pipe is treated with blasting by shot, grit, sand, and the like. In some cases, a polyurea resin is sprayed directly onto the surface of a steel pipe to paint.

Looking at the prior art with respect to the present invention, the Republic of Korea Patent No. 10-0860009 (Date: 2008. 09. 25) is slightly lower initial reactivity compared to the conventional polyurea, but the synthetic polymerization during the polymerization reaction is almost the same In order to prevent the formation of microbubbles in the minute portion as it proceeds, (A) mixing a diisocyanate, polyoxyalkylene glycol and alkylene carbonate to synthesize a prepolymer, (B) a curing agent comprising an amine chain extender and an antifoaming agent Providing a composition, (C) reacting the prepolymer and the curing agent composition to synthesize a polyurea coating agent, the invention has a reaction step proceeds in two steps and during the reaction In the manufacturing method of the polyurea coating agent which does not use a solvent, by combination of a specific component The generated prepolymer and poly description of the manufacturing method and the coating method of the coating material for synthesizing urea by mixing in a heated state, the curing agent compositions are described.

In addition, the polyurethane-polyurea paint for internal water pipe coating disclosed in Korean Patent Registration No. 10-0993243 (Date: 2010. 11. 10) is a urethane prepolymer obtained by the reaction of diisocyanate and polyol, the first 100 parts by weight of the main portion formed by reacting the pigment and the first reaction additive, and 40 to 70 parts by weight of the curing agent portion formed by reacting the amine, the second pigment, the filler, and the second reaction additive, wherein the isocyanate group of the main portion and the curing agent portion The molar ratio of amine groups is 1: 0.8 to 1: 1. The water coating inner coating film formed of the above-described paint is excellent in flexibility by urethane prepolymer, excellent in durability by urea, and can be quickly carried out due to fast curing time, and can maintain waterproof performance for a long time.

On the other hand, the present invention is the polymerization of the isocyanate (-NCO) and the compound (-OH, -NH, -SH) and the reacting compound (-OH, -NH, -SH) used in synthesizing the urethane prepolymer at a high temperature as the time remaining when the unreacted isocyanate groups remain In order to prevent increase in viscosity or gelation due to the reaction of unreacted isocyanate, additional polymerization inhibitor can be added to terminate the reaction to ensure long-term storage stability, and the polyurea resin coating composition prepared therefrom is uniform and excellent. The present invention has been completed by paying attention to the fact that the coating quality can be secured.

An object of the present invention is to provide a polyether to the main portion containing a urethane prepolymer produced by polymerization of diisocyanate, polyoxyalkylene glycol and alkylene carbonate. When a polyurea resin coating composition is prepared by mixing a curing agent portion containing an amine, a wet dispersant, a pigment, a chain extender, an adhesion enhancer, an antifoaming agent, and a fluidity control agent, a polymerization inhibitor (Polymerization) is prepared in the main part. by adding an inhibitor) to prevent the increase of viscosity or gelation due to the reaction of unreacted isocyanate and to terminate the polymerization reaction of urethane prepolymer, so that not only the storage stability of the paint but also the coating film coated on the surface of the steel pipe Physical properties such as bending resistance, impact resistance, abrasion resistance, and saline resistance, water resistance, egg resistance Polyurea resin for internal and external coating of steel pipes that has excellent chemical properties such as chemical resistance, gasoline resistance, and resistance to cathodic disbondment test, and does not cause damage or peeling of coating due to local current. The present invention provides a coating composition and a method of manufacturing the same.

Another object of the present invention is a solvent-free type of hardening type paint, the viscosity of which is maintained uniformly to improve the airtightness and adhesion of the inner and outer surfaces of the steel pipe, and to control the thickness of the coating film freely, and also high temperature (40 ℃ or more), Even when applied under high pressure spraying pressure (1500psi or higher), thick film coating is possible compared to the existing paint, and dust generation is reduced, thus reducing the waste of materials and good workability and environmentally friendly poly for internal and external coating of steel pipe. The present invention provides a urea resin paint composition and a method of manufacturing the same.

Polyurea resin coating composition for internal and external coating of the steel pipe of the present invention for solving the above problems, 55 to 70 parts by weight of diisocyanate, 25 to 35 parts by weight of polyoxyalkylene glycol (Polyoxyalkylene glycol) And a main part containing 0.01 to 0.1 parts by weight of a polymerization inhibitor based on 100 parts by weight of a urethane prepolymer produced by a polymerization reaction of 5 to 15 parts by weight of alkylene carbonate. 0.1 to 0.4 parts by weight of a wet dispersant, 4 to 7 parts by weight of pigment, 5 to 8 parts by weight of chain extender, 0.4 to 0.7 parts by weight of adhesion enhancer, and 0.4 to 0.7 antifoaming agent based on 100 parts by weight of polyether amine It is composed of a hardener portion containing 0.1 parts by weight to 2.0 parts by weight of the flow control agent, wherein the main portion and the hardener portion is characterized in that it comprises a ratio of 40 to 60% by weight, respectively.

In addition, the production method of the polyurea resin coating composition for coating the inner and outer coating of the steel pipe of the present invention, diisocyanate 55 ~ 70 parts by weight, polyoxyalkylene glycol 25 ~ 35 parts by weight, alkylene 5-15 parts by weight of carbonate (Alkylene carbonate) was added to the reaction vessel and then gradually heated up with stirring to maintain isothermal temperature at 60-90 ° C. for 2-5 hours, and the content of isocyanate group (-N = C = O). When the 15 to 25% of the heat is cut and gradually cooled to synthesize a urethane prepolymer (Urethane prepolymer), at 50 ℃ or less based on 100 parts by weight of the polymerization reaction inhibitor (Polymerization inhibitor) by adding 0.01 ~ 0.1 parts by weight Uniformly stirring for 0.5 to 1.5 hours to form a main portion; 25 to 30 parts by weight of polyether amine, 0.1 to 0.4 parts by weight of a wet dispersant, and 4 to 7 parts by weight of a pigment are added to a separate container and dispersed to have a particle size of 20 μm or less, and then polyetheramine ( Polyether amine) 65 ~ 70 parts by weight, chain extender 5 ~ 8 parts by weight, adhesion enhancer 0.4 ~ 0.7 parts by weight, antifoaming agent 0.4 ~ 0.7 parts by weight, fluidity regulator 0.1 ~ 2.0 parts by adding 1 to 2 hours at 2000rpm Stirring to form a hardener portion; The main portion and the curing agent formed as described above is characterized in that it comprises a step of mixing at a ratio of 40 to 60% by weight, respectively.

And the method of coating the polyurea resin coating composition on the surface of the steel pipe of the present invention comprises the steps of preparing a main portion and a hardener portion formed as described above; The polyurea resin coating composition prepared by mixing the main portion and the hardener portion at a temperature of 50 to 80 ° C. at a ratio of 40 to 60% by weight, respectively, was sprayed at a pressure of 1500 to 3000 psi to the inside or the outside of the steel pipe. Characterized in that it comprises a step of applying.

Hereinafter, each component in the specific Example of this invention is as follows.

The polymerization inhibitor is used any one or more of 2-ethylhexyl acid phosphate (2-Ethylhexyl acid Phosphate), phosphoric acid (H ₃ PO ₄ , Phosphoric acid).

The wet dispersant is a high molecular weight block copolymer solution having a pigment affinity group, an alkylammonium salt solution of an acidic polymer, a hydroxy functional group carboxylic ester solution having a pigment affinity group, a low molecular unsaturated polycarboxylic acid polymer solution, a polysiloxane air Any one or more of copolymer and low molecular weight unsaturated polycarboxylic acid polymer solution, alkylammonium salt solution of polycarboxylic acid, copolymer solution having acidic group, and low molecular weight unsaturated polycarboxylic acid polymer can be used.

The pigment may be any one or more of titanium dioxide, carbon black, phthalocyanine blue, phthalocyanine green, phthalocyanine green, zinc oxide, and zinc sulfide.

The chain extender is diethyl-toluenediamine (DETDA), dimethylthio-toluenediamine (DMTDA), N, N'-di (sec-butyl) -amino-biphenylmethane (N, N′-di (sec.butyl) -amino-biphenyl methane, DBMDA), 4,4′-methylenebis- (3-chloro-2,6-diethyl) -aniline (4,4′-methylenebis -(3-chloro, 2,6-diethyl) -aniline, MCDEA), cycloaliphatic amine, Secondary aliphatic amine, Secondary aliphatic diamine, Secondary aromatic diamine Any one or more of (Secondary aromatic diamine) can be used.

The adhesion enhancing agent is 2- (3,4 epoxycyclohexyl) -ethyltrimethoxysilane (2- (3,4 epoxycyclohexyl) -ethyltrimethoxysilane), 3-glycidoxypropylmethyl diethoxysilane, 3-aminopropyl triethoxysilane, N- (2-aminoethyl) 3-aminopropyl methyl dimethoxysilane (N- (2-aminoethyl) 3-aminopropylmethyl dimethoxysilane), N- (2 -Aminoethyl) 3-aminopropyl trimethoxysilane (N- (2-aminoethyl) 3-aminopropyl trimethoxysilane), N- (2-aminoethyl) 3-aminopropyl triethoxysilane (N- (2-aminoethyl) 3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxysilane, 3-mercaptopropyl trimethoxysilane, 3-glycidoxypropyl trimethoxysilane (3- Glycidoxypropyl trimethoxysilane, gamma-glycidoxypropyl trimethoxysilane Select at least any one silane coupling that can be used for agent (Silane coupling agent).

The antifoaming agent may be any one or more of mineral oil-based antifoaming agent, silicone antifoaming agent, non-silicone-based polymer antifoaming agent.

The fluidity regulator may be any one or more of fumed silica, urea resin, polyamide wax, and bentonite.

Polyurea resin coating composition for coating the inner and outer coatings of the steel pipe of the present invention is a urethane prepolymer produced by the polymerization of diisocyanate, polyoxyalkylene glycol and alkylene carbonate ( In addition to storage stability, the urethane prepolymer can be terminated by preventing the increase of viscosity or gelation due to the reaction of unreacted isocyanate by the action of the polymerization inhibitor (Polymerization inhibitor) on the main part containing urethane prepolymer. The coated film coated on the surface of the steel pipe has excellent physical properties such as adhesion to the surface, bending resistance, impact resistance and abrasion resistance, and chemical properties such as salt water resistance, water resistance, alkali resistance, and gasoline resistance, and also cathodic disbondment. ) The resistance to the test is very good, so that the coating film is damaged and There is an effect of forming a high-strength, high durability coating film that does not occur.

In addition, the polyurea resin coating composition for coating the inner and outer coating of the steel pipe manufactured by the manufacturing method of the present invention, the viscosity is uniformly maintained to improve the airtightness and adhesion of the inner and outer surfaces of the steel pipe, the high temperature (40 ℃)), even when applied under high pressure spraying pressure (1500psi or more), it generates less dust than conventional coatings, so it is less waste of materials and has good workability. It is a solvent-free type of fast curing paint Thick film (1 mm or more) is not only possible to paint, but also has an effect of providing an environmentally friendly coating film because the harmful substances do not leak.

Method for producing a polyurea resin coating composition for coating the inner and outer coating of the steel pipe of the present invention, diisocyanate 55 to 70 parts by weight, polyoxyalkylene glycol 25 to 35 parts by weight, alkylene carbonate ( Alkylene carbonate) 5-15 parts by weight were added to a reaction vessel, and then gradually warmed up with stirring to maintain isothermal temperature at 60-90 ° C. for 2-5 hours, and the content of isocyanate group (-N = C = O) was 15 ~ 25% to cut off the heat and slowly cool to synthesize a urethane prepolymer (Urethane prepolymer), at 50 ℃ or less based on 100 parts by weight of the polymerization reaction (Polymerization inhibitor) 0.01 ~ 0.1 parts by weight of 0.5 ~ Stirring uniformly for 1.5 hours to form the main part; 25 to 30 parts by weight of polyether amine, 0.1 to 0.4 parts by weight of a wet dispersant, and 4 to 7 parts by weight of a pigment are added to a separate container and dispersed to have a particle size of 20 μm or less, and then polyetheramine ( Polyether amine) 65 ~ 70 parts by weight, chain extender 5 ~ 8 parts by weight, adhesion force enhancer 0.4 ~ 0.7 parts by weight, antifoaming agent 0.4 ~ 0.7 parts by weight, fluidity regulator 0.1 ~ 2.0 parts by adding 1 to 2 hours at 2000rpm Stirring to form a hardener portion; It comprises a step of mixing the main portion and the curing agent portion formed as described above in a ratio of 40 to 60% by weight, respectively.

Hereinafter, the operation of the configuration of the present invention will be described in detail, which is intended to illustrate to the extent that one of ordinary skill in the art to which the present invention pertains can easily carry out the invention, and thus the technical scope of the present invention. It should be understood to include equivalents or substitutes included therein, which does not mean that the technical spirit and scope of the present invention are limited.

First, forming the main part, 55 to 70 parts by weight of diisocyanate, 25 to 35 parts by weight of polyoxyalkylene glycol, 5 to 15 parts by weight of alkylene carbonate in the reaction vessel After the addition, the mixture is gradually heated while stirring and isothermally maintained at 60 to 90 ° C. for 2 to 5 hours. When the content of the isocyanate group (-N = C = O) is 15 to 25%, the heat is blocked and gradually cooled. By synthesizing the urethane prepolymer (Prepolymer), by adding 0.01 ~ 0.1 parts by weight of a polymerization inhibitor (Polymerization inhibitor) based on 100 parts by weight of the urethane prepolymer at 50 ℃ or less to uniformly stirred for 0.5 to 1.5 hours.

The urethane prepolymer of the main part reacts with diisocyanate, polyoxyalkylene glycol, alkylene carbonate to form a urethane bond, and has strength and flexibility suitable for paint for internal and external coating of steel pipe. In general, the end of the urethane prepolymer is reacted to maintain the isocyanate group to less than 15%, but in the present invention, when the isocyanate group residual ratio in the urethane prepolymer is 15 to 25%, the heat is blocked and a polymerization inhibitor is added to prevent the reaction. By preventing the increase in viscosity or gelation due to the reaction of the reaction isocyanate and terminating the polymerization reaction of the urethane prepolymer, the storage stability is improved and the adhesion to the inner and outer surfaces of the steel pipe is improved. At this time, the molecular weight of the urethane prepolymer is preferably 5,000 to 100,000, which is when the molecular weight of the urethane prepolymer is less than 5,000, the flexibility and impact resistance of the coating film is weak, if the molecular weight exceeds 100,000, the paint viscosity is high spray workability Because it gets worse.

The diisocyanate is a compound used to synthesize a urethane prepolymer and forms a hard block in a coating film, thereby providing mechanical strength, tensile strength, elasticity, wear resistance, aging resistance, oil resistance, solvent resistance, impact resistance, and low temperature. It shows the characteristics of stability, and its type can be used both aliphatic isocyanate and aromatic isocyanate without particular limitation, but in general, when aromatic isocyanate is used, the melting point and hardness is higher than that of synthesized polyurethane (or polyurea) using aliphatic isocyanate. Higher materials are synthesized.

In the present invention, as the diisocyanate compound, 4,4'-diphenylmethane diisocyanate (MDI), cyclohexylmethane diisocyanate (H12MDI), 1,6-hexamethylene diisocyanate (1,6-Hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI) or the like was used alone or mixed, and used as a 55 ~ 70 parts by weight based on 100 parts by weight of the urethane prepolymer It has been studied to be suitable for showing both flexibility and flexibility, and at the same time, good durability. If the reaction proceeds by adding an isocyanate group in excess, it may react with other newly formed functional groups in the polymer.

The polyoxyalkylene glycol is an alkylene oxide derivative and is a transparent colorless liquid and has a low pour point. Since the molecular weight distribution curve is very narrow, polyol compounds having a hydroxyl functional group (-OH, Hydroxyl group) of diol or triol are frequently used in the urethane prepolymer polymerization reaction, and elongation, wear resistance, high elasticity and tensile strength are used. It is used for the purpose of improving hardness and flexibility.

The alkylene carbonate is used for the purpose of improving the storage properties and viscosity of the polyurethane prepolymer, lowering the uniformity of the main part and the curing agent, and improving the leveling of the coating surface during spray coating of the paint.

And the polymerization inhibitor is 0.01 ~ 0.1 based on 100 parts by weight of any one or more of the 2-ethylhexyl acid phosphate (2-Ethylhexyl acid phosphate) or phosphoric acid (H ₃ PO ₄ , Phosphoric acid) when the urethane prepolymer is synthesized By weight part, the polymerization of the isocyanate (-NCO) and the compound (-OH, -NH, -SH) and the reacting compound (-OH, -NH, -SH) used to synthesize the urethane prepolymer at a high temperature, the time after the unreacted isocyanate group remaining This prevents the increase in viscosity or gelation caused by the reaction of unreacted isocyanate and terminates the reaction, thereby increasing the long-term storage stability of the polyurethane prepolymer and obtaining a polyurea resin composition having good adhesion.

Next, the step of forming the curing agent portion, 25 to 30 parts by weight of polyetheramine, 0.1 to 0.4 parts by weight of the wet dispersant, 4 to 7 parts by weight of the pigment is added to a separate container and dispersed so that the particle size is 20㎛ or less Again, 65 to 70 parts by weight of polyetheramine, 5 to 8 parts by weight of chain extender, 0.4 to 0.7 parts by weight of adhesion enhancer, 0.4 to 0.7 parts by weight of antifoaming agent, and 0.1 to 2.0 parts by weight of flow control agent were added at 1 to 2000 rpm. Stir for 2 hours.

The first step of forming the curing agent portion, 25 to 30 parts by weight of polyetheramine, 0.1 to 0.4 parts by weight of the wet dispersant, 4 to 7 parts by weight of the pigment is added to a separate container and dispersed so that the particle size is 20㎛ or less In this case, the polyetheramine Various compounds with a molecular weight of 200 to 5,000 g / mol with primary amine groups are very fast to react with isocyanate functional groups (-NCO), allowing for improved flexibility, toughness and low viscosity formulations. This makes it possible to produce a homogeneous product by adding and dispersing an appropriate amount of the wet dispersant and the pigment.

The wet dispersant is a high molecular weight block copolymer solution having a pigment affinity group, an alkylammonium salt solution of an acidic polymer, a hydroxy functional group carboxylic ester solution having a pigment affinity group, a low molecular unsaturated polycarboxylic acid polymer solution, a polysiloxane air 0.1 to 0.4 parts by weight of any one or more of a polymer and a low molecular unsaturated polycarboxylic acid polymer solution, an alkyl ammonium salt solution of polycarboxylic acid, a copolymer solution having an acidic group, a low molecular unsaturated polycarboxylic acid polymer Uniformly disperse solid pigments in resin (resin or binder) to prevent agglomeration and sedimentation during storage, to improve color separation, color change, flowability, smoothness after painting and to prevent gloss of cured coating film It works. In addition, the contact angle between the pigment and the resin solution is lowered to allow the liquid to penetrate into the pigment aggregate structure more quickly. The dispersant adsorbs onto the pigment surface to maintain a constant gap between the pigment due to electrostatic repulsion or steric hindrance. This prevents pigments from reaggregating.

The pigment is used 4 to 7 parts by weight of any one or more of titanium dioxide, carbon black (Carbon black), phthalocyanine blue (Phthalocyanine blue), phthalocyanine green (Phthalocyanine green), zinc oxide, zinc sulfide, Disperse into fine particles together with the liquid resin to give the color of the coating film, mainly white, black, blue, green and gray. In addition, it may be added within about 1 to 3% by weight based on the total weight of the main part or the curing agent to determine the mixing stability by distinguishing the main part and the curing agent.

The second step of forming the curing agent portion, in addition to the dispersion prepared by the dispersion process in the first step, 65 to 70 parts by weight of polyetheramine, 5 to 8 parts by weight of chain extender, 0.4 ~ 0.7 adhesion strength enhancer By adding 0.4 to 0.7 parts by weight of the antifoaming agent and 0.1 to 2.0 parts by weight of the antifoaming agent and stirring at 2000 rpm for 1 to 2 hours, the desired properties required by the present invention are determined by appropriate composition and action of each component. Will be exercised.

The chain extender is diethyl-toluenediamine (DETDA), dimethylthio-toluenediamine (DMTDA), N, N'-di (sec-butyl) -amino-biphenylmethane (N, N′-Di (sec.butyl) -amino-biphenyl methane, DBMDA), 4,4′-methylenebis- (3-chloro-2,6-diethyl) -aniline (4,4′-Methylenebis -(3-chloro, 2,6-diethyl) -aniline, MCDEA), cycloaliphatic amine, Secondary aliphatic amine, Secondary aliphatic diamine, Secondary aromatic diamine 5 to 8 parts by weight of any one or more of (Secondary aromatic diamine), which contributes to the formation of a hard block (Hard block) when forming a coating film, imparts heat resistance of the cured coating film, delays (controls) reactivity This improves the coating workability and the smoothness of the coating film.

The adhesion enhancing agent is 2- (3,4 epoxycyclohexyl) -ethyltrimethoxysilane (2- (3,4 Epoxycyclohexyl) -ethyltrimethoxysilane), 3-glycidoxypropylmethyl diethoxysilane, 3-aminopropyl triethoxysilane, N- (2-aminoethyl) 3-aminopropyl methyl dimethoxysilane, N- (2 -Aminoethyl) 3-aminopropyl trimethoxysilane (N- (2-Aminoethyl) 3-aminopropyl trimethoxysilane), N- (2-aminoethyl) 3-aminopropyl triethoxysilane (N- (2-Aminoethyl) 3-aminopropyl triethoxysilane), 3-aminopropyl trimethoxysilane, 3-mercaptopropyl trimethoxysilane, 3-glycidoxypropyl trimethoxysilane (3- Glycidoxypropyl trimethoxysilane, gamma-glycidoxypropyl trimethoxysilane A silane coupling agent which is selected at least one kinds (Silane coupling agent) to include 0.4 to 0.7 parts by weight, to enhance the reaction and the bonding strength between the different types of sojimyeon thereby giving excellent adhesion.

The antifoaming agent includes 0.4 to 0.7 parts by weight of any one or more of a mineral oil-based antifoaming agent, a silicone-based antifoaming agent, and a non-silicone-based polymer antifoaming agent, which is a liquid having a low surface tension and incorporated into the paint during the manufacturing process of the coating or during the painting operation. By removing the bubbles generated by the bubbles or the shape of the object in a short time, it serves to maintain the physical properties and improve the appearance of the dried coating film.

The fluidity regulator includes 0.1 to 2.0 parts by weight of any one or more of fumed silica, urea resin, polyamide wax, bentonite, and the like. For example, fumed silica particles containing silanol groups on the surface of the coating film form a three-dimensional structure by hydrogen bonding to increase viscosity and give thixotropy, and urea resin has a very fine crystal shaped needle structure. When the three-dimensional network is formed and the network formed in the paint that requires a low viscosity while the paint is applied is sufficiently destroyed by the low shear force, the structure of the coating is very fast because the structure is regenerated very quickly after the paint is applied. To exhibit the effect of preventing the pigment flow.

Finally, the mixing step is to mix the main portion and the curing agent portion formed as described above in a ratio of 40 to 60% by weight, respectively, the characteristics typically required by the above mixing ratio, for example, adhesion strength, flex resistance , Impact resistance, water absorption, hardness, wear resistance, chemical resistance, etc. have been studied to satisfy sufficiently, most preferably, the volume ratio of the main part and the hardener part is set to 1.00 and the weight ratio is set to 1.10 to 1.30. Good to do.

In addition, the method of coating the polyurea resin coating composition prepared according to the present invention on the surface of the steel pipe as an example, will be described, respectively, in the state of heating the main portion and the hardener portion prepared as described above at a temperature of 50 ~ 80 ℃ After preparing a polyurea resin coating composition by mixing at a ratio of 40 to 60% by weight, the coating is completed by applying a spray injection pressure of 1500 ~ 3000psi to the inside and / or outside of the steel pipe. Is about 50 to 150 seconds (23 ° C. standard) and shows relatively fast curing properties.

As described above, the present invention has been completed through numerous experiments. Hereinafter, the present invention will be described through preferred embodiments to be easily understood and implemented by those skilled in the art.

≪ Example 1 >

(Production of the subject matter)

55 parts by weight of 4,4'-diphenylmethane diisocyanate (MDI), 35 parts by weight of polyoxyalkylene glycol, 10 parts by weight of alkylene carbonate The solution was gradually heated and stirred at 70 ° C. for 3 hours. Then, when the content of the isocyanate group (-N = C = O) was 15-25%, the heat was cut off and cooled slowly. Synthesis of a prepolymer (Urethane prepolymer) was carried out at 50 ° C or less, based on 100 parts by weight of the urethane prepolymer, 0.01 parts by weight of 2-ethylhexyl acid phosphate was added and stirred uniformly for 1 hour to prepare a main part. .

(Production of Hardener Part)

25 parts by weight of polyether amine, 0.1 parts by weight of a wet dispersant, and 5 parts by weight of pigment are added to a separate container, dispersed to have a particle size of 20 μm or less, and then 70 parts by weight of polyether amine. , 6 parts by weight of chain extender, 0.5 parts by weight of adhesion enhancer, 0.5 parts by weight of antifoaming agent, 1.5 parts by weight of fluidity regulator were added and stirred at 2000 rpm for 1 to 2 hours to prepare a curing agent part.

(Formation of Coating Film)

High Pressure Collision Mixer (Two Line System) Two main lines are supplied with the main part and the hardener part, and are sprayed by high pressure impact mixing from the mix module inside the spray gun GRACO 'REACTOR E-XP2' Polyurea resin coating composition in which the main portion and the curing agent portion were mixed at a weight ratio of 40:60, respectively, was applied to the inside of the water supply pipe at an injection pressure of 1500 to 3000 psi at a temperature of about 70 ° C. to form a coating film. At this time, the dry contact time of the paint was 60 seconds based on 23 ℃.

<Example 2>

(Production of the subject matter)

60 parts by weight of 4,4'-Diphenylmethane diisocyanate (MDI), 30 parts by weight of polyoxyalkylene glycol, 10 parts by weight of alkylene carbonate The solution was gradually heated and stirred at 80 ° C. for 3 hours. Then, when the content of the isocyanate group (-N = C = O) was 15-25%, the heat was cut off and gradually cooled to urethane. Synthesis of a prepolymer (Urethane prepolymer), at 50 ℃ or less based on 100 parts by weight of the urethane prepolymer was added to 0.05 parts by weight of 2-ethylhexyl acid phosphate (2-Ethylhexyl acid phosphate) was uniformly stirred for 1 hour to prepare a main part. .

(Production of Hardener Part)

25 parts by weight of polyether amine, 0.2 parts by weight of a wet dispersant, and 5 parts by weight of pigment are added to a separate container, and dispersed to have a particle size of 20 μm or less, and then 70 parts by weight of polyether amine. , 7 parts by weight of chain extender, 0.6 parts by weight of adhesion enhancer, 0.6 parts by weight of antifoaming agent, and 1 part by weight of flow control agent were added, followed by stirring at 2000 rpm for 1 to 2 hours to prepare a curing agent part.

(Formation of Coating Film)

High Pressure Collision Mixer (Two Line System) Two main lines are supplied with the main part and the hardener part, and are sprayed by high pressure impact mixing from the mix module inside the spray gun GRACO 'REACTOR E-XP2' Polyurea resin coating composition mixed with the main portion and the curing agent portion at a weight ratio of 50: 50 was applied to the inside of the water supply pipe at an injection pressure of 1500 to 3000 psi at a temperature of about 60 ° C. to form a coating film. At this time, the dry contact time of the paint was 90 seconds based on 23 ℃.

<Example 3>

(Production of the subject matter)

65 parts by weight of 4,4'-diphenylmethane diisocyanate (MDI), 25 parts by weight of polyoxyalkylene glycol, 10 parts by weight of alkylene carbonate The solution was gradually heated and stirred at 80 ° C. for 3 hours. Then, when the content of the isocyanate group (-N = C = O) was 15-25%, the heat was cut off and gradually cooled to urethane. Synthesis of a prepolymer (Urethane prepolymer), but at 50 ℃ or less based on 100 parts by weight of the urethane prepolymer 0.1 parts by weight of 2-ethylhexyl acid phosphate (2-Ethylhexyl acid phosphate) was added to uniformly stirred for 1 hour to prepare a main part. .

(Production of Hardener Part)

30 parts by weight of polyether amine, 0.2 parts by weight of a wet dispersant, and 5 parts by weight of pigment are added to a separate container and dispersed to have a particle size of 20 μm or less, and then 65 parts by weight of polyether amine. , 8 parts by weight of chain extender, 0.7 parts by weight of adhesion enhancer, 0.7 parts by weight of antifoaming agent, 0.5 parts by weight of fluidity regulator was added and stirred at 2000 rpm for 1 to 2 hours to prepare a curing agent part.

(Formation of Coating Film)

High Pressure Collision Mixing Special Sprayer (Two Line System, two separate lines, main part and resin part are supplied and sprayed by high pressure impact mixing from the mixing module inside the spray gun.) GRACO 'REACTOR E-XP2' Polyurea resin coating composition mixed with the main portion and the curing agent portion at a weight ratio of 60: 40, respectively, was applied to the inside of the water supply pipe at an injection pressure of 1500 to 3000 psi at a temperature of about 60 ° C. to form a coating film. At this time, the touch drying time of the paint was 120 seconds based on 23 ° C.

<Comparative Example 1> to <Comparative Example 3>

Preparation of the polyurea resin coating composition according to Comparative Examples 1 to 3 was carried out in each of Examples 1 to 3, except that 2-ethylhexyl acid phosphate was not added as a polymerization inhibitor during synthesis of the main part. Prepared under the same conditions and the same components, and by the same method was applied inside the water pipe to form a coating film. At this time, the touch-drying time of the paint is represented as 40 seconds, 65 seconds, 100 seconds based on 23 ℃.

<Experimental Example>

The coating films formed in Examples 1 to 3 and Comparative Examples 1 to 3, respectively, were repeatedly measured five times according to the test criteria defined in the American Water Association (AWWA C 222-99). The average values are shown in Table 1 below.

Item Test condition and unit Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Bond strength psi 1,830 2,170 2,430 1,450 1,570 1,675 Flexibility 4 ″ mandrel over 180 ° bending More than
none More than
none More than
none Cracks Cracks Cracks Impact resistance 500g × 100cm × 5 / 8˝ More than
none More than
none More than
none Pinhole
Occur Pinhole
Occur Pinhole
Occur Absorption rate 23 ° C, 24 hours (%) 1.0 0.7 0.5 1.6 1.9 2.4 Hardness Shore d 69 72 75 64 69 72 Pinhole test 3000 V More than
none More than
none More than
none Pinhole
Occur Pinhole
Occur Pinhole
Occur Cathode Peeling -1.5V, room temperature 28 days 6 mm radius 4 mm radius 2 mm radius 20 mm radius 17 mm radius 15 mm radius Wear resistance CS-17 Wheel, 1㎏, 1000 revolutions 3mg 5mg 10 mg 17mg 23mg 35mg









Chemical resistance
(Immersion for 30 days at room temperature)

10% H ₂ SO ₄ weight
% Change 1.5 1.2 0.7 2.2 2.0 1.8 diameter
% Change 0.5 0.4 0.1 0.8 0.7 0.5 thickness
% Change 0.4 0.4 0.3 0.8 0.8 0.6

30% NaCl weight
% Change 0.9 0.7 0.4 1.3 1.3 1.2 diameter
% Change 0.2 0.2 -0.1 0.5 0.3 0.3 thickness
% Change 0.1 0.1 0.0 0.3 0.2 0.2

30% NaOH weight
% Change 0.5 0.3 -0.2 1.0 0.9 0.9 diameter
% Change 0.1 -0.1 0.0 0.4 0.4 0.2 thickness
% Change 0.3 0.3 0.2 0.8 0.7 0.6

# 2 diesel fuel oil weight
% Change 1.7 1.5 -0.1 2.8 2.6 2.2 diameter
% Change 0.4 0.3 -0.1 0.9 0.8 0.6 thickness
% Change 0.5 0.3 0.2 1.0 0.8 0.7

As shown in Table 1, Example 1 to Example 3, wherein the coating film is formed inside the water supply pipe according to the present invention, by adding a polymerization inhibitor when synthesizing the urethane prepolymer, the adhesive strength, bending resistance, and The physical and chemical properties such as impact, water absorption, hardness, pinhole test, negative electrode peeling, abrasion resistance, and chemical resistance were remarkably improved, and the viscosity of the paint was kept uniform and the drying time was delayed by about 20 seconds. It was confirmed that the airtightness and adhesion to the inner and outer surfaces of the steel pipe were improved.

And even if the polyurea resin coating composition of the present invention is applied at a spray injection pressure of high temperature (40 ℃ or more) and high pressure (1500 psi or more), the generation of dust is reduced compared to the conventional paint is less waste of material and good workability, It is a solvent-free type of quick-curing paint that can not only coat thick films (1 mm or more) at a time, but also has the advantage that no harmful substances are spilled.

Accordingly, the polyurea resin coating composition for coating the inner and outer coatings of the steel pipe of the present invention may be substituted, modified, and changed in various ways without departing from the technical spirit of the present invention, and water, sewage, general water, and other fluids. It is an environmentally friendly material that can be used for various purposes such as waterproofing and anticorrosive purposes of underground buried steel structures such as steel pipes used for transportation piping, and can be used in various uses and forms.

Claims (10)

Urethane prepolymer produced by polymerization of 55 to 70 parts by weight of diisocyanate, 25 to 35 parts by weight of polyoxyalkylene glycol and 5 to 15 parts by weight of alkylene carbonate A main part containing 0.01 to 0.1 parts by weight of a polymerization inhibitor based on 100 parts by weight;
0.1 to 0.4 parts by weight of wet dispersion agent, 4 to 7 parts by weight of pigment, 5 to 8 parts by weight of chain extender, 0.4 to 0.7 parts by weight of adhesion enhancer, and 0.4 to 0.7 antifoaming agent based on 100 parts by weight of polyether amine Part by weight, a curing agent part containing 0.1 to 2.0 parts by weight of a fluidity regulator; Lt; / RTI &gt;
The main portion and the hardener portion of the polyurea resin coating composition for the inner and outer coating of the steel pipe, characterized in that comprises a ratio of 40 to 60% by weight, respectively. The method of claim 1,
The polymerization inhibitor is a polyurea resin coating composition for internal and external coating of steel pipes, characterized in that any one or more of 2-ethylhexyl acid phosphate, phosphoric acid (H ₃ PO ₄ , Phosphoric acid). . The method of claim 1,
The wet dispersant is a high molecular weight block copolymer solution having a pigment affinity group, an alkylammonium salt solution of an acidic polymer, a hydroxy functional group carboxylic ester solution having a pigment affinity group, a low molecular unsaturated polycarboxylic acid polymer solution, a polysiloxane air Inner and outer coating of steel pipes, characterized in that any one or more of a polymer and a low molecular unsaturated polycarboxylic acid polymer solution, an alkyl ammonium salt solution of polycarboxylic acid, a copolymer solution having an acidic group, a low molecular unsaturated polycarboxylic acid polymer Polyurea resin paint composition. The method of claim 1,
The pigment may be any one or more of titanium dioxide, carbon black, carbon black, phthalocyanine blue, phthalocyanine green, phthalocyanine green, zinc oxide, and zinc sulfide. Polyurea resin paint composition for coating. The method of claim 1,
The chain extender is diethyl-toluenediamine (DETDA), dimethylthio-toluenediamine (DMTDA), N, N'-di (sec-butyl) -amino-biphenylmethane (N, N′-Di (sec.butyl) -amino-biphenyl methane, DBMDA), 4,4′-methylenebis- (3-chloro-2,6-diethyl) -aniline (4,4′-Methylenebis -(3-chloro, 2,6-diethyl) -aniline, MCDEA), cycloaliphatic amine, Secondary aliphatic amine, Secondary aliphatic diamine, Secondary aromatic diamine Polyurea resin coating composition for internal and external coating of steel pipes, characterized in that at least one of (Secondary aromatic diamine) The method of claim 1,
The adhesion enhancing agent is 2- (3,4 epoxycyclohexyl) -ethyltrimethoxysilane (2- (3,4 Epoxycyclohexyl) -ethyltrimethoxysilane), 3-glycidoxypropylmethyl diethoxysilane, 3-aminopropyl triethoxysilane, N- (2-aminoethyl) 3-aminopropyl methyl dimethoxysilane, N- (2 -Aminoethyl) 3-aminopropyl trimethoxysilane (N- (2-Aminoethyl) 3-aminopropyl trimethoxysilane), N- (2-aminoethyl) 3-aminopropyl triethoxysilane (N- (2-Aminoethyl) 3-aminopropyl triethoxysilane), 3-aminopropyl trimethoxysilane, 3-mercaptopropyl trimethoxysilane, 3-glycidoxypropyl trimethoxysilane (3- From Glycidoxypropyl trimethoxysilane, Gamma-glycidoxypropyl trimethoxysilane Polyurea resin coating composition for internal and external coating of steel pipe, characterized in that composed of any one or more selected silane coupling agent (Silane coupling agent). The method of claim 1,
The antifoaming agent is a polyurea resin coating composition for internal and external coating of steel pipes, characterized in that any one or more of mineral oil-based defoamer, silicone-based defoamer, non-silicone-based polymer defoamer. The method of claim 1,
The fluidity modifier is a polyurea resin coating for internal and external coating of steel pipes, characterized in that any one or more of fumed silica, urea resin, polyamide wax, bentonite Composition. 55 to 70 parts by weight of diisocyanate, 25 to 35 parts by weight of polyoxyalkylene glycol, and 5 to 15 parts by weight of alkylene carbonate were added to the reaction vessel, and the temperature was gradually increased while stirring. Urethane isothermal is maintained at ~ 90 ℃ for 2 to 5 hours, when the content of isocyanate group (-N = C = O) is 15 to 25%, heat is blocked and gradually cooled to synthesize urethane prepolymer However, at 50 ° C. or less, based on 100 parts by weight of the urethane prepolymer, 0.01 to 0.1 parts by weight of a polymerization inhibitor (Polymerization inhibitor) is added to uniformly stir for 0.5 to 1.5 hours to form a main part;
25 to 30 parts by weight of polyether amine, 0.1 to 0.4 parts by weight of a wet dispersant, and 4 to 7 parts by weight of a pigment are added to a separate container and dispersed to have a particle size of 20 μm or less, and then polyetheramine ( Polyether amine) 65 ~ 70 parts by weight, chain extender 5 ~ 8 parts by weight, adhesion force enhancer 0.4 ~ 0.7 parts by weight, antifoaming agent 0.4 ~ 0.7 parts by weight, fluidity regulator 0.1 ~ 2.0 parts by adding 1 to 2 hours at 2000rpm Stirring to form a hardener portion;
Mixing the main portion and the hardener portion formed as described above at a ratio of 40 to 60% by weight, respectively;
Method for producing a polyurea resin coating composition for internal and external coating of steel pipe, characterized in that consisting of. Preparing a main part and a curing agent part according to any one of claims 1 to 8;
Polyurea resin coating composition prepared by mixing the main portion and the hardener portion at a temperature of 50 to 80 ° C. at a ratio of 40 to 60% by weight, respectively, with a spray injection pressure of 1500 to 3000 psi inside or outside the steel pipe. Applying;
Method for coating a polyurea resin coating composition on the surface of the steel pipe comprising a.