KR101693224B1 - Composition of heavy duty coating - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to a coating liquid composition, and more particularly, to an environmentally friendly heavy liquid coating composition comprising hydroxyalkyl methyl cellulose ether, hydroxypropylmethyl cellulose and the like.

Description

TECHNICAL FIELD [0001] The present invention relates to a composition for a high-

TECHNICAL FIELD The present invention relates to a coating liquid composition, and more particularly, to an environmentally friendly heavy liquid coating liquid composition having excellent anticorrosive properties and adhesiveness, including hydroxyalkylmethyl cellulose ether, hydroxypropyl methylcellulose and the like.

Generally, most of the structures including iron are exposed to the corrosive environment in the natural environment. Therefore, in order to improve the weatherability of the structure, corrosion prevention treatment is generally applied on the surface of the structure to prevent corrosion. Such treatment is referred to as a heavy-duty coating, which protects bridges, steel towers, offshore structures, nuclear power plants, large water bodies of various plants, ships or other structures lying in the corrosive environment from corrosion, . That is, the coating agent for heavy metals is a coating agent that exhibits functions such as insulation, corrosion resistance, heat resistance, acid resistance, abrasion resistance, antifouling property and chemical resistance.

Currently used heavy-duty coatings include aluminum-based coatings, fluororesin-based coatings, urethane-based coatings, and ceramic coatings.

First, the aluminum-based coating is excellent in corrosion resistance, durability, weatherability, and basicity, and is excellent in workability by using the same paint as the undercoat, middle, and topcoat, The initial construction cost is high, and it is difficult to mix the adhesive and the metal mixture, so that only a skilled engineer can construct the construction.

The fluororesin-based coating is advantageous in that the liquid epoxy epoxy-based zinc primer is used as a primer, the thick film epoxy is used as a middle layer, and the fluororesin is applied twice as a top coat, , The initial construction cost is high and the work process is also complicated.

The urethane-based coating uses a liquid epoxy-based zinc primer as a primer, a thick-film epoxy as a middle layer, and a polyurethane as a top coat, and the corrosion resistance, durability, weather resistance, In particular, the maintenance cost is increased because the life span is short.

In general, ceramic coatings, which are widely used for heavy-duty coatings, use ceramic urethane as a top coat and undercoat and middle coat coatings. They are excellent in corrosion resistance, durability, weatherability and resistance to alkalinity, There is a problem that the initial cost of the coating film and the initial cost are high.

In general, the ceramic coating uses colloidal silica as an inorganic binder, but the inorganic binder can not maintain the inorganic characteristics of SiO ₂ for a long time because of its low adhesive strength. Ceramic coating agents using many existing colloidal silica as binders increase the possibility of fire by using petroleum based organic materials such as epoxy, silicone, or urethane to solve the adhesion problem of the coating agent, However, the lack of adhesion was not solved. For this reason, in order to improve the adhesion, a strict surface treatment process is required before applying the ceramic coating agent, for example, pretreatment of the iron plate, removal of the existing paint, or grinding treatment for surface roughness, .

Korean Patent No. 0764081 proposes a waterborne coating composition and a binder resin composition for eco-friendly ultra-heavy and ultra-weathering systems. However, the prior art has various problems such as a short life time, a decrease in adhesive force depending on the kind of metal, and difficulty in application to non-metal surfaces.

Korea Patent No. 0764081

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art,

It is environmentally friendly and contains water retention capacity, adhesiveness, antiseptic properties, and the like, including organic compounds such as hydroxyalkyl methyl cellulose ether (HMC) and hydroxypropyl methyl cellulose (HPMC) And an object of the present invention is to provide an excellent coating composition for a heavy-duty food.

Further, it is an object of the present invention to provide a coating composition for a middle-range edible liquid which has a sufficient heat resistance and is a one-part type and has a simple coating process and a long life time.

According to the present invention,

(HMC) and hydroxypropylmethylcellulose (HPMC): octylsilane: isopropyl alcohol: methyltriethoxysilane = 0.1 to 0.3: 0.1 to 0.3: 0.3 to 0.6: 1 were mixed The first reaction solution;

And a second reaction solution in which distilled water: silica sol (colloidal silica) = 1.0 to 1.8: 1 is mixed in a weight ratio of the first reaction solution to the second reaction solution.

The coating liquid composition of the present invention contains two kinds of modified cellulose derived from cellulose, and has environment-friendly characteristics, and is excellent in anticorrosion, heat resistance, and can provide an effect of controlling drying time.

Also, it is possible to provide a coating liquid composition which is excellent in adhesiveness to metals and base metals, has a long lifetime, is excellent in economy, and is easy to work as a one-part type and applicable to various industrial fields.

FIG. 1 is a schematic view illustrating a process for producing a coating composition for a heavy metal corrosion inhibitor according to the present invention.

Hereinafter, the present invention will be described in detail.

According to the present invention,

A first reaction solution in which hydroxyalkylmethylcellulose ether and hydroxypropylmethylcellulose: octylsilane: isopropyl alcohol: methyltriethoxysilane = 0.1 to 0.3: 0.1 to 0.3: 0.3 to 0.6: 1 are mixed in a weight ratio; And

And a second reaction solution in which distilled water: silica sol (colloidal silica) = 1.0 to 1.8: 1 is mixed in a weight ratio.

According to a preferred embodiment of the present invention, the present invention relates to a composition comprising hydroxyalkyl methyl cellulose (HMC) and hydroxypropyl methyl cellulose (HPMC), one of the modified cellulose of water-soluble natural polymers, Thereby providing a coating liquid composition.

HMC can be obtained by reacting cellulose extracted from wood with methyl chloride and alkylene oxide. It can be used as a thickener, a repairing agent and a pressure-sensitive adhesive in mixed use with architectural and edible materials such as plastic, adhesive, tile cement and mixed mortar to improve workability Uniform condensation and high strength. Especially, it is used as a material for foodstuffs. One of the characteristics of HMC is water retention capacity which protects and maintains water. Therefore, it can increase the workability and slowly release moisture to attach the substrate firmly. have. Therefore, it is possible to solve the problem of adhesion failure of a ceramic coating agent or the like using a conventional chemical organic pressure-sensitive adhesive.

However, when only H. CM is contained as an organic component, the drying time becomes long and it is difficult to further coat other coatings having other functions, and the surface may be contaminated due to foreign substances during drying. Accordingly, the present invention provides a coating liquid composition characterized by containing hydroxypropylmethyl cellulose (H.P.M.C) having a degree of substitution and a particle distribution similar to those of H.M.C as other organic components, and this problem can be solved through this.

Hydroxypropylmethylcellulose (H.P.M.C) is widely used as a pharmaceutical ingredient such as a thickening stabilizer, a suspension agent and a moisturizer. Generally, the particle size of the derivative is smaller than that of H.M.C. However, since the hydroxpropyl group has a relatively low hydration bond strength to water as compared with the hydroxyxy group, it does not have a significant effect on the viscosity. The drying time can be reduced by reducing the amount of H.P.M.C used when the working environment is easy and not greatly affected by the drying time, and by increasing the amount of H.P.M.C to be higher than H.M.C when fast curing is required. H.P.M.C has properties that facilitate mixing with H.M.C but do not affect the chemical action.

In the present invention, the use ratio of H.M.C and H.P.M.C is not particularly limited, but it is preferably 1: 0.1 to 1: 3 by weight, more preferably 1: 0.5 to 1: 2 by weight. When the content is within the above range, the curing rate and water retention can be excellent.

As described above, the heavy edible coating liquid composition of the present invention contains hydroxyalkylmethyl cellulose ether and hydroxypropylmethyl cellulose: octylsilane: isopropyl alcohol: methyltriethoxysilane in a ratio of 0.1: 0.3: 0.1 to 0.3: 0.3 To 0.6: 1 are mixed.

As a method for producing the first reaction solution, an ordinary method can be applied, but the following method can be used as an example.

In order to prepare the first reaction solution, HMC and HPMC: octylsilane: isopropyl alcohol: methyltriethoxysilane were first prepared at a weight ratio of 0.1-0.3: 0.1-0.3: 0.3-0.6: 1, Methyltriethoxysilane is added. At this time, the mixing vessel may be maintained at a temperature of 25 to 35 ° C, and the first reaction solution may be prepared in the range of the above-mentioned temperature. A stirrer and a heating or cooling device for controlling the temperature may be installed in the mixing vessel. After adding methyltriethoxysilane, a predetermined amount of octylsilane is put into the mixing vessel and stirred. While isopropyl alcohol is added and stirred, HMC and HPMC are added together and stirring is continued. The order of addition of each component is not particularly limited since the product may affect the particle size, content, viscosity, dissolution rate, stirring speed, etc. of HMC or HPMC. However, it may be preferable that the HMC and the HPMC are added so that the separation of the two components does not occur, considering the quality of the resultant product.

In addition, the heavy edible coating liquid composition of the present invention is characterized by comprising a second reaction solution in which distilled water: silica sol (colloidal silica) = 1.0 to 1.8: 1 is mixed in a weight ratio as described above. Here, the silica sol refers to colloidal silica in which silica or silicon dioxide (SiO ₂ ) exists in a colloidal state. Colloidal silica is amorphous spherical silica present in a liquid phase and may be made from alkali silicates, but is not limited thereto. The distilled water refers to water not containing an alkali or acidic ion component such as ion-exchanged water, and preferably has a pH of 7.

In the present invention, the silica sol may be prepared by mixing ethanol: distilled water: Tetra Ethyl Ortho Silicate (TEOS): hydrochloric acid = 0.5-0.6: 1.5-2.5: 1.2-1.00: 0.004-0.006 in weight ratio It is not.

As a method for producing the second reaction solution, an ordinary method can be applied, but the following method can be used as an example.

Ethanol: Distilled water: TEOS: Hydrochloric acid is prepared at a weight ratio of 0.5-0.6: 1.5-2.5: 1.2-1.5: 0.004-0.006, ethanol is added to a stirrer equipped with a temperature controller, and TEOS is slowly added. The distilled water is slowly injected in the rapidly stirred state, and the following reaction proceeds. (CH ₃ CH ₂ O) ₄ Si + 4H ₂ O → (OH) ₄ Si + 4CH ₃ CH ₂ OH (OH) ₄ Si + SiO ₂ + 2H ₂ )

After 5 minutes, add hydrochloric acid little by little and keep stirring at a constant temperature of 50 ° C for 1 hour and 30 minutes.

In addition, when using commercially available silica sol (colloidal silica), it is possible to prepare the second reaction solution by mixing with distilled water, but the result may vary depending on the ratio of the distilled water.

The average diameter of the silica sol for preparing the second reaction solution according to the present invention may be 10 to 200 nm. When the diameter is within the above-mentioned range, there is an advantage that the improvement in water retention of the composition mixed with the first reaction solution is maximized. The silica solid content based on the total weight of the silica sol may preferably be 30 to 50 wt%, more preferably 30 to 40 wt%. As an example, if the prepared silica sol contains 40% by weight of solids, the second reaction solution may be prepared by mixing distilled water: silica sol = 1.0 to 1.8: 1 by weight. The order of introduction for the preparation of the silica sol is not particularly limited in the present invention.

As described above, when the first reaction solution and the second reaction solution are prepared, they can be mixed to prepare the heavy edible coating liquid composition of the present invention. The mixing ratio of the first reaction solution and the second reaction solution is not particularly limited, but is preferably a weight ratio of the first reaction solution: the second reaction solution = 2.0 to 2.5: 1. If the weight ratio is as described above, it is advantageous to mix the first reaction solution and the second reaction solution.

The method for preparing the heavy edible coating liquid composition of the present invention by mixing the first reaction solution and the second reaction solution may be a conventional method in the art.

The first reaction solution is connected to a mixing vessel having a second reaction solution by a tube provided with a valve that can be opened and closed in the reaction vessel, and the solution can be mixed. When the first reaction solution and the second reaction solution are mixed and stirred, heat may be generated because an exothermic reaction proceeds. Therefore, the mixing vessel needs to be maintained at a constant mixing temperature by using a cooling device, preferably at a temperature of 30 to 45 ° C. If the temperature exceeds the above range, the water-retentivity of the two modified cellulose may deteriorate. The reaction rate may be from about 120 to about 180 minutes after the second reaction solution is completely introduced into the first reaction solution, but the present invention is not limited thereto.

When the first reaction solution and the second reaction solution are mixed and the stirring is completed, a filler having a functional property may be further added. Examples of the filler include aluminum oxide (Al ₂ O _{3 )} , titanium dioxide (TiO ₂ ), potassium carbonate (CaCO ₃ ) and pigments, but not limited thereto, and at least one of them can be selected and used . It is also possible to fit the coloring material to the coating object by inserting the filler material as described above. It is preferable that the filler material is added in an amount of 5 to 25% by weight based on the total weight of the coating liquid composition of the present invention. When the filler is used within the above-mentioned range, it is preferable since the desired color can be exhibited without affecting the characteristics of the coating liquid composition.

The heavy metal coating liquid composition according to the present invention is advantageous in that it can be coated by a brush, a roller or a spray method, has a simple working process, and does not affect the environment due to its environmentally friendly composition.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the following examples illustrate the present invention and the present invention is not limited by the following examples, and various modifications and changes may be made. The scope of the present invention will be determined by the technical idea of the following claims.

< Example  And Comparative Example >

Example  One.

Step 1: 100 kg of methyltriethoxysilane was charged into the mixing vessel and maintained at 40 占 폚. 25 kg of octylsilane was added thereto and stirred. Then, 60 kg of isopropyl alcohol was added, and 10 kg of H.M.C and 5 kg of H.P.M.C were added simultaneously with stirring to prepare a first reaction solution (H.M.C .: H.P.M.C = 1: 0.5 weight ratio)

Second Step: 50 kg of silica sol having a solid content of 40% by weight and 50 kg of distilled water were put into a mixing vessel and stirred to prepare a second reaction solution.

Step 3: To 200 kg of the first reaction solution, 100 kg of the second reaction solution was added with stirring and the temperature was maintained at 35 캜. After the addition of the second reaction solution was completed, stirring was continued for 150 minutes.

Step 4: After the third step, 15 kg of titanium dioxide (TiO ₂ ) for negative power was added as a filler to prepare a coating solution composition for heavy drinking.

In order to confirm the performance of the coating solution prepared from the coating solution composition, the following test examples were tested and the results are shown in Table 1.

Example  2 to 4.

(Example 2, HMC: HPMC = 1: 1 weight ratio) and 15 kg (Example 3, HMC: HPMC = 1: 1 weight ratio) were prepared in the same manner as in Example 1, 1: 1.5 weight ratio) or 20 kg (Example 4, HMC: HPMC = 1: 2 weight ratio).

< Test Example >

As the coating conditions, the coating liquid compositions of Examples 1 to 4 were coated on a test piece treated with a pretreatment standard ISO SA 2.5 by using an air spray coating machine so that the coating liquid composition was 200 탆 or less once with a dry coating film. The prepared coating film was evaluated as follows.

Touch dry time  evaluation

Table 1 below shows the time required for curing the coating film coated at the same thickness with the coating compositions of Examples 1 to 4 at 25 DEG C and touching with the fingers until there is no tackiness.

Viscosity evaluation

The viscosity of the coating liquid compositions of Examples 1 to 4 was evaluated to evaluate coating properties. The viscosity was measured using a rotary viscometer (DV-11 from Brookfield) and the results are shown in Table 1 below.

Adhesion evaluation

The adhesion of the coating liquid compositions of Examples 1 to 4 was evaluated according to the test method of ASTM D 4541, and the results are shown in Table 1 below.

Performance evaluation

As a method performance evaluation method for the coating film formed using the coating liquid compositions of Examples 1 to 4, the impedance change according to Electrochemical Impedance Spectroscopy (EIS) was measured. Specifically, the change of impedance (resistance) was measured while contacting the coated specimen with the etching solution for a predetermined period of time, and the performance of the coating film was evaluated. In this case, it was evaluated that the corrosion resistance was excellent when the reduction rate of the resistance according to the contact time was small and the rate of change of the reduction rate with time was small. Each impedance reduction ratio was derived by the following formula.

Impedance reduction rate (%) = (Initial impedance measurement - Impedance measurement after time) / (Initial impedance measurement) 100

H.M.C .: H.P.M.C Touch dry time
(Room temperature 25 ° C) Viscosity
(cps) Adhesion evaluation
(25 DEG C) Performance evaluation
15-day reduction rate (%) Example 1 1: 0.5 50 minutes 600 1100 psi 70 Example 2 1: 1 38 minutes 500 1050 psi 65 Example 3 1: 1.5 30 minutes 500 957 psi 65 Example 4 1: 2 26 minutes 500 912 psi 70

As shown in Table 1, all of the coating liquid compositions of Examples 1 to 4 exhibited a drying time of less than 60 minutes and a good adhesion level of 900 psi or more. Also, it can be confirmed that the viscosity of the coating liquid composition according to the content of H.P.M.C does not affect the viscosity when the content exceeds the above amount. Therefore, it is easy to appropriately adjust the content of H.P.M.C according to purposes.

The performance of the coating compositions of Examples 2 to 3 was found to be the most excellent in the effect of reducing the impedance with time, and in Examples 1 to 4, the reduction rate was 70% or less Therefore, it can be confirmed that the level is suitable for use.

Claims (6)

A first reaction solution in which hydroxyalkylmethylcellulose ether and hydroxypropylmethylcellulose: octylsilane: isopropyl alcohol: methyltriethoxysilane = 0.1 to 0.3: 0.1 to 0.3: 0.3 to 0.6: 1 are mixed in a weight ratio; And
And a second reaction solution in which distilled water: silica sol = 1.0 to 1.8: 1 is mixed in a weight ratio. The method according to claim 1,
Wherein the first reaction solution and the second reaction solution are mixed at a weight ratio of 2 to 2.5: 1. The method according to claim 1,
Wherein the weight ratio of hydroxyalkylmethylcellulose ether to hydroxypropylmethylcellulose is 1: 0.1 to 1: 3. The method according to claim 1,
Wherein the solid content of silica is 30 to 50% by weight based on the total weight of the silica sol. The method according to claim 1,
And a filler. &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt; The method of claim 2,
Wherein the mixing of the first reaction solution and the second reaction solution is performed at 30 to 45 캜.

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