KR100709071B1 - Eco-friendly epoxy paint composition for waterproof coating without solvent - Google Patents

Abstract

The present invention relates to an environment-friendly low-temperature curing solvent-free epoxy coating, and more particularly, to a coating composition for a waterproofing coating film, which is composed mainly of a low viscosity epoxy resin and an amineamide curing agent. The coating composition according to the present invention is excellent in adhesiveness and does not need to use a solvent as a low viscosity, and has excellent properties in water resistance, chemical resistance, hardness, gloss and low temperature curing, and does not generate amine brushing.

Epoxy paint, film waterproofing agent, amineamide curing agent, eco-friendly, solventless

Description

Eco-friendly epoxy paint composition for waterproof coating without solvent}

The present invention relates to an environment-friendly low-temperature curing solvent-free epoxy coating composition used as a coating film waterproofing agent.

Epoxy resins are generally used by adding a curing agent and various compounding materials and changing them into thermosetting materials. Since epoxy resins can exhibit various physical properties, they can be used in various fields such as electrical, electronics, civil engineering, construction, automobiles, adhesives, fillers, It is used in various applications such as abrasives, coatings, waterproofing agents, and insulations.

Epoxy resin can be cured at various temperature ranges according to the type of curing agent to be added. Therefore, an appropriate curing agent is selected and used as needed. The room temperature curing agent of epoxy resin is mainly used polyamines, amine derivatives and polyamide resins. There is also a Mannich base.

In the case of using an aliphatic polyamine as a curing agent, it generally has a fast curing speed and low viscosity, but has a disadvantage in that amine brushing occurs at a short pot life and at low temperatures. On the other hand, when polyamide resin is used as a curing agent, it is most widely used because of its long pot life, excellent adhesion and high mechanical strength, but its high viscosity, low curing rate at low temperatures, and poor compatibility with epoxy resins. have. Although organic solvents can be added to the manufacturing and work processes to reduce the viscosity of the resin and control the pot life, the use of these volatile organic solvents is not only harmful to the human body but also adversely affects the environment. .

In addition, although a small amount of an epoxy resin and an aliphatic amine in advance are used as a curing agent, in order to obtain such an adduct, an excess of aliphatic amines are reacted with an epoxy resin. By forming a carbamic salt by reacting with water or carbon dioxide in the air, there is a disadvantage of lowering gloss and causing amine brushing. Although the above disadvantages can be solved to some extent by removing aliphatic amines through distillation under reduced pressure after synthesis of the adduct, this method not only consumes excessive manufacturing costs but also causes amine brushing at low temperatures.

Recently, Mannich bases are used as a curing accelerator in combination with polyamide resins, but they have poor flexibility and poor water resistance, and because of the characteristics of the tertiary amine groups contained in Mannich bases, the coating is fragile and smelly. And yellowing phenomenon occurs.

Accordingly, the present invention is excellent in low-temperature curing properties, does not generate amine brushing even in winter, and does not use an organic solvent, it is an object to provide a low-viscosity epoxy paint that is environmentally friendly and excellent in adhesion, water resistance, chemical resistance, hardness, glossiness do.

The coating composition according to the present invention is composed of an epoxy resin, an amineamide compound, a filler and a diluent, and an additive, and is composed of a main part consisting of an epoxy resin, a filler and a diluent, an additive, and a curing agent part consisting of an amineamide compound, a diluent, and an additive. It is provided in the form of a two-part paint.

In the present invention, an epoxy resin having an epoxy equivalent of 50-500, more preferably 80-300, having at least two or more epoxy groups in one molecule is used. When the epoxy resin is out of this range, the viscosity is too high and the dispersibility of the paint It is not suitable because of poor paintability. Epoxy resins satisfying the above conditions may be in various forms such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, glycidyl ester type epoxy resins, cyclohexanediol epoxy resins, phenol block type epoxy resins, cresol type epoxy resins, and the like. There is already a commercial one. In the present invention, one type of the epoxy resin is selected and used, or two or more types are selected and used.

The amineamide compound according to the present invention is prepared by reacting a polyamine containing a primary amine with formamide. More specifically, the primary amine and formamide in an aliphatic polyamine containing a primary amine are reacted in an equivalent ratio. And ammonia is generated as a by-product of the reaction. The structural formula of the amineamide compound as a product according to the above reaction is described in the following Chemical Formula 1, and the reaction scheme is described in the following Scheme 1.

Amineamide Compounds

In Formula 1 n is an integer of 0-5.

Scheme 1. Preparation of Amineamide Compound

In Scheme 1, n is an integer of 0-5.

The amineamide compound according to the present invention has a low viscosity and has excellent compatibility and reactivity with the low viscosity modified epoxy resin. The amount of the amineamide compound added in the coating composition is such that the equivalent ratio with the epoxy resin is in the range of 0.9 to 1.5, thereby preventing the unreacted residue from deteriorating the physical properties of the coating film.

Fillers and diluents in the present invention to adjust the viscosity, gel time, mechanical strength, hardness, density, gloss, flowability, etc. of the paint and to improve the weather resistance, corrosion resistance, chemical resistance, water resistance, flame retardancy, hiding properties, etc. Can be used. However, when the content of the filler and the diluent is too low, the purpose of use is not achieved. On the contrary, when the content of the filler and the diluent is too high, the coating property or the curing speed may be affected. Therefore, it is preferable to use 80-150 parts by weight based on 100 parts by weight of the epoxy resin.

As a filler, various components such as TALC, calcium carbonate, aluminum hydroxide, silica, talc and activated carbon can be used. In addition, titanium dioxide and carbon black. Fillers with toning functions such as cyanine blue, cyanine green, YIO, IOR, antimony trioxide, calcium silicate can also be used. Diluents can be classified into reactive diluents and non-reactive diluents. Reactive diluents, including glycidyl ethers, can be used to control hardness and flexibility, and non-reactive diluents, including phthalate, can be used to lower the viscosity. .

Additives used in the present invention include a colorant, a catalyst, a dispersant, an antifoaming agent, a sedimentation inhibitor and the like, and is selected and applied according to the purpose.

The coating composition according to the present invention contains an epoxy resin, an amineamide compound, a filler and a diluent, and an additive according to the above, and is composed of a main portion consisting of an epoxy resin, a filler and a diluent, and an additive, an amineamide compound, a diluent, and an additive. It is provided in the form of a two-part paint composed of a hardener portion. Each component in the coating composition contains 80-150 parts by weight of the amineamide compound, 50-200 parts by weight of the filler and diluent, and 1-20 parts by weight of the additive with respect to 100 parts by weight of the epoxy resin.

Embodiments according to the present invention can be described as follows, which is presented to aid the understanding of the present invention, the present invention is not limited thereto.

Example 1 Preparation of Main Section

190 g of liquid bisphenol A type epoxy resin and 190 g of liquid bisphenol F type epoxy resin were added to a container, mixed, and stirred. The bisphenol A type epoxy resin and the bisphenol F type epoxy resin were YD128 and YDF170 of Kukdo Chemical, and the structural formulas are shown in Chemical Formulas 2 and 3.

Structural formula of bisphenol A epoxy resin (YD128)

In Formula 2 n is an integer of 0-3.

Structural formula of bisphenol F type epoxy resin (YDF170)

In Formula 3 n is an integer of 0-3.

150 g of silica, 350 g of calcium silicate and 66 g of benzyl alcohol were added to the mixture of the epoxy resins, followed by mixing. Then, 1 g of antisettling agent, 5 g of dispersant, 13 g of antifoaming agent, and 35 g of colorant were added and stirred until uniform.

Example 2 Preparation of Amineamide Compound Using Diethylenetriamine

103 g of diethylenetriamine and 90 g of formamide were added to a clean four-necked flask, and the mixture was sufficiently stirred at room temperature and reacted while gradually raising the temperature to 80 ° C. The amine equivalents of the substances in the reaction vessel were measured while collecting the ammonia gas, which began to be generated when the temperature reached 60 ° C., through the vessel containing water. When the amine equivalent weight was 160, the reaction was terminated and the collector was removed from the flask. The structural formula of the product according to the reaction is shown in the following formula (4).

Amineamide Compounds According to Formula 4

Example 3 Preparation of Amineamide Compound Using Triethylenetetraamine

146 g of triethylenetetraamine and 90 g of formamide were added to a clean four-necked flask, and the mixture was sufficiently stirred and reacted while gradually raising the temperature to 90 ° C. The amine equivalents of the substances in the reaction vessel were measured while collecting the ammonia gas, which began to develop as the temperature reached 67 ° C., through the vessel containing water. When the amine equivalent weight was 101, the reaction was terminated and the collector was removed from the flask. The structural formula of the product according to the reaction is shown in the following formula (5).

Amineamide Compounds According to Formula 3

Example 4 Preparation of Amineamide Compound Using Tetraethylenepentaamine

189 g of tetraethylenepentaamine and 90 g of formamide were added to a clean four-necked flask, and the mixture was sufficiently stirred and reacted while gradually raising the temperature to 100 ° C. The ammonia equivalent of the material in the reaction vessel was measured while collecting the ammonia gas, which began to develop when the temperature reached 75 ° C, through the vessel containing water. The reaction was terminated when the amine equivalent weight was 82 and the collector was removed from the flask. The structural formula of the product according to the reaction is shown in the following formula (6).

Amineamide Compounds According to Formula 4

Example 5 Preparation of Curing Agent Part and Paint

30g of the amineamide compound produced in Example 2, 8g of benzyl alcohol and 1g of K-54 were uniformly mixed to prepare a curing agent part. 40 g of the curing agent and 200 g of the main part prepared according to Example 1 were uniformly mixed to prepare a paint 1. Paint 2 and paint 3 were prepared by the same method as paint 1, following the composition of Table 1 below.

Table 1. Composition ratio of paint

Paint 1 Paint 2 Paint 3 Part 200 200 200  Curing agent part Amineamide compounds  30  26  24 Benzyl alcohol   8  12  14 K-54   2   2   2 Sum 240 240 240

Experiment 1. Physical Properties of Coating Film

The coating material according to Example 2 was coated on an iron specimen under a condition of 25 ° C at room temperature so as to have a dry coating thickness of 300 μm, thereby forming a coating film. Gel time was measured 100g tack free time, and the glossiness was measured at a light receiving angle of 60 °. The water resistance was measured by comparing the ASTM D714 and blister after immersing the coating film in fresh water for 30 days, and the acid resistance was measured by comparing the ASTM D714 and blister after immersing the coating film in 5% sulfuric acid solution for 7 days. Hardness was measured by Shore D hardness, and shear adhesion was measured using UTM in the method specified in KSM3734. Amine brushing formed a coating film at 5 ° C and confirmed the occurrence of whitening phenomenon. The experimental results accordingly are shown in Table 2 below.

Table 2. Experimental Results of Coating Films

Paint 1 Paint 2 Paints 3 Gel time (min) 65 60 54  Hardness (SHORE D) 12 hours 45-50 55-60 60-65 24 hours 65-60 65-70 70-75 48 hours 70-75 75-80 78-82 72 hours 78 81 83 Glossiness (GU) 98 or more 98 or more 98 or more Shear Adhesion (Kgf / ㎠) 167 200 220 Blister none none none Blister none none none Amine brushing Does not appear Does not appear Does not appear

As shown in Table 2, the coating composition according to the present invention has a low viscosity, excellent adhesion, water resistance, acid resistance, hardness, gloss and low temperature curability, and does not occur amine brushing. Therefore, the epoxy paint according to the present invention can be particularly useful as a coating film waterproofing agent due to the above characteristics.

As described above, the waterproofing coating composition mainly composed of the low viscosity modified epoxy resin and the amineamide compound according to the present invention has a low viscosity and is excellent in adhesion, water resistance, chemical resistance, hardness, glossiness, and low temperature curing property. In addition, since it does not require a solvent, it has eco-friendly characteristics in the manufacturing process and the painting process and does not reduce the thickness of the coating film due to solvent evaporation. In addition, excellent low-temperature curing properties and amine brushing does not occur, it is easy to form a thick film even during winter outdoor coating has the effect of shortening the coating process and reducing the cost.

Claims (4)

Hardening agent for epoxy paints containing the compound of following formula (1). Formula 1.

In Formula 1, n is an integer of 0 to 5. Epoxy coating composition for waterproofing coating film containing said hardening | curing agent of Claim 1. A curing agent for epoxy paints containing any one of compounds selected from the following formulas (4), (5) and (6). Formula 4.

Formula 5.

Formula 6.

Epoxy coating composition for waterproofing coating film containing said hardening | curing agent of Claim 3.