KR102184247B1 - A protective coating having secondary damage preventing ability - Google Patents

Abstract

The present invention is a polymer composition for forming a matrix; And a microcapsule containing a healing material and dispersed in the polymer composition, wherein the healing material is composed of a mixture of vegetable oil and divinyl compound. When the self-healing coating solution is applied on a substrate such as a structural material and the formed coating material is damaged by cracks or scratches, the microcapsules of the damaged area break and the healing material flows out, filling the damaged area, and then chemical reaction by the action of oxygen in the atmosphere. Is converted into a viscoelastic material. Since the viscoelastic material can prevent secondary damage from occurring in the healed part, it is possible to improve the stability and economy of the coating material and/or the structural material.

Description

Self-healing protective coating with secondary damage prevention function {A protective coating having secondary damage preventing ability}

The present invention relates to a self-healing coating solution having a secondary damage prevention function and a self-healing coating material using the same.

Materials such as concrete or steel, which are mainly used as structural materials, may undergo corrosion by moisture, chlorine ions, and the like, and thus the mechanical performance of the material may be significantly reduced. Therefore, in order to prevent corrosion of the structural material as described above, it is common to apply a protective coating formulation to the surface of the structural material.

However, conventionally, the protective coating, dried by applying a protective coating solution on the substrate, does not have a self-healing function, so when damage to the protective coating material occurs, moisture, chlorine ions, etc. may penetrate into the damaged gap and corrosion could continue. . Accordingly, in order to prevent corrosion, the damaged portion of the coating material had to be repaired or replaced, and thus, there was a problem in that the cost of the repair or replacement occurred.

The self-healing properties of polymer materials are recently given to allow the material to heal itself in the event of damage such as cracks, thereby dramatically increasing the life of coating materials and/or structural materials, and reducing the cost of repair or replacement. The self-healing protective coating technology, which is economically advantageous and has various other advantages, is attracting much attention.

Among them, a representative technology is a microcapsule type self-healing protective coating material technology in which microcapsules containing healing substances are dispersed in a coating liquid composition. In the method developed so far, when the coating material is damaged, the microcapsules in the damaged area are broken, and the healing material in the damaged area leaks out, fills the damaged area and causes a polymerization reaction to become a hard solid. However, in this method, secondary damage is likely to occur in the healed part, and since the capsule of the damaged part is already broken and the healing substance is consumed, there is a problem that it is impossible to repeatedly heal.

In particular, structural materials used in bridges, tunnels, buildings, etc. are exposed to various vibrations caused by automobile traffic and machine operation, and such vibrations can create and propagate secondary damage to the self-healing solid part. In addition, in the conventional microcapsule type self-healing protective coating material technology, most of the catalysts for polymerizing healing substances are used, and measures such as light irradiation are often required.

Korean Patent Registration No. 10-1168038 Korean Patent Registration No. 10-1780451

Soo Hyoun Cho, Scott R. White, and Paul V. Braun, Self-Healing Polymer Coatings, Adv. Mater. 2009, 21, 645-649. Hye-In Yang, Dong-Min Kim, Hwan-Chul Yu, and Chan-Moon Chung, Microcapsule-Type Organogel-Based Self-Healing System Having Secondary Damage Preventing Capability, ACS Appl. Mater. Interfaces, 2016, 8, 11070-11075.

The present invention was conceived to solve the above problems, and the healing material was converted to a vegetable oil-based polymer having viscoelasticity after filling the damaged area, thereby preventing the generation and propagation of secondary damage, and a self-healing coating solution using the same. It was intended to provide a self-healing coating material.

In one embodiment of the present invention for achieving the above object, a polymer composition for forming a matrix; And a microcapsule containing a healing material and dispersed in the polymer composition, wherein the healing material contains a mixture of vegetable oil and divinyl compound, and the self-healing coating solution is applied on a substrate to form a coating material When the damage is damaged, the microcapsules of the damaged part are broken and the healing material flows out, and the healing material fills the damaged part and then provides a self-healing coating solution that is converted into a viscoelastic material.

In another embodiment of the present invention, a method for preparing the self-healing coating solution includes: (a) preparing a microcapsule containing a vegetable oil and a divinyl compound; (b) Injecting microcapsules into a polymer composition for forming a matrix and uniformly dispersing a self-healing coating solution is provided.

In another embodiment of the present invention, it provides a self-healing coating material formed by applying the self-healing coating solution on a substrate.

According to the present invention, since it is possible to prevent secondary damage from occurring in the damaged portion of the coating material formed by applying the self-healing coating liquid on the substrate, it is possible to improve the stability and economy of the coating material and/or structural material.

In addition, according to the present invention, a catalyst is not used when activating the performance of a coating material formed by applying a self-healing coating solution on a substrate, and there is an effect that the performance can be expressed without additional conditions such as light irradiation.

1 shows a schematic structure of a microcapsule prepared according to Example 1 of the present invention:
The core part contains healing substances, and the capsule part is made of a polymer.
FIG. 2 is a scanning electron microscope (SEM) photograph showing that damage was not caused to (a) a control coating containing no microcapsules according to Example 3 of the present invention, (b ) SEM photograph showing self-healing when damage occurred to the self-healing coating material containing microcapsules, and (c) secondary damage was not occurred when vibration (10~30 Hz) was applied to the self-healing coating material in which healing occurred. This is an SEM picture showing the sound.

Terms used throughout the specification including the detailed description and claims of the present invention are defined as follows.

In the present invention, the term “self-healing” refers to the original protection of the coating material when damage such as cracks or scratches occurs in the microcapsule-type self-healing protective coating material, and the healing material flows out to fill the damaged part and convert it into a healing reaction product. It means that the function recovers on its own without artificial measures from the outside.

In addition, in the present invention, “microcapsule” refers to a capsule having a micro size, and “capsule” herein refers to a microcontainer that may contain solid, liquid, gas, or a combination thereof.

Hereinafter, the present invention will be described in detail.

Self-healing coating solution according to an embodiment for achieving the object of the present invention, a polymer composition for forming a matrix; It contains microcapsules containing a mixture of vegetable oil and divinyl compounds as healing substances in the capsule membrane.

When the coating material coated with the self-healing coating solution is damaged, the microcapsule breaks from the damaged area and the healing material flows out, fills the damaged area, and causes a chemical reaction by the action of oxygen in the atmosphere to convert it into a viscoelastic material. Healing takes place.

The vegetable oil according to an embodiment of the present invention is linseed oil, tung oil, rapeseed oil, paulownia oil, soybean oil, dehydrated castor oil, rapeseed oil, sesame oil, perilla oil, cottonseed oil, rice bran oil (rice bran oil), it is preferred to include at least one selected from the group consisting of soybean oil and corn oil.

The divinyl compound according to an embodiment of the present invention is 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, ethylene glycol dimethacrylate, diurethane dimethacrylate, 1,6 -Hexanediol dimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate Rate, 1,6-hexanediol ethoxylate diacrylate, bisphenol A ethoxylate diacrylate, bisphenol A propoxylate diacrylate, polyethylene glycol diacrylate, tetra(ethylene glycol) diacrylate, di( At least one selected from the group consisting of ethylene glycol) diacrylate, ethylene glycol diacrylate, ethylene diacrylate, neopentyl glycol diacrylate, poly(propylene glycol) diacrylate, and tri(propylene glycol) diacrylate It includes the above.

In the healing material, the divinyl compound is preferably contained in the range of 0.1 to 30% by weight based on the total weight of the healing material. When the healing material contains less than 0.1% by weight of the divinyl compound, the healing material flows out of the microcapsules and the resulting film tends to be torn by vibrations of 10 to 30 Hz. When the healing material contains more than 30% by weight of the divinyl compound, the healing material flows out of the microcapsules and the resulting film tends to be broken by the vibration of 10 to 30 Hz. Therefore, the divinyl compound of the present invention must be contained in the range of 0.1 to 30% by weight based on the total weight of the healing substance to exhibit the effect provided by the present invention.

The microcapsule according to an embodiment of the present invention comprises a mixture of the vegetable oil and divinyl compound as a core part, and a polymer capsule film surrounding the core part (FIG. 1).

The capsule membrane serves to shield and protect the healing material contained in the core from the external environment, and when damage occurs to the self-healing coating material containing the microcapsule, the capsule membrane breaks and the healing material flows out. have.

It is preferable that the capsule membrane has suitable mechanical properties that are not broken during handling and can be broken only when damage occurs. In addition, while preventing the core existing in the capsule film from leaking to the outside, it should be able to prevent foreign substances from entering the core, and should have excellent thermal stability and excellent adhesion to the matrix material.

The material of the capsule film of the microcapsule according to an embodiment of the present invention may be a polymer selected from the group consisting of urea-formaldehyde polymer, urea-melamine-formaldehyde polymer, and melamine-formaldehyde polymer.

The microcapsule is not particularly limited in shape and may be a spherical shape mainly including a circular or elliptical shape.

The diameter of the microcapsules according to an embodiment of the present invention may be 5 to 500 µm, more specifically 20 to 200 µm. If the diameter of the microcapsule is less than 5 μm, the amount of the healing material flowing out is insufficient, so that self-healing may be insufficient, and if the diameter of the microcapsule is 500 μm or more, there may be a problem of protruding from the coating material surface.

The microcapsules are dispersed in the composition for forming a matrix, and the composition for forming the matrix is enamel paint, acrylic resin, vinyl resin, epoxy resin, chlorinated rubber resin, polyurethane resin, polyester resin, polyacrylate resin. It may include at least one composition selected from the group consisting of resin, melamine-based resin, epoxide-based coating material, polyester-epoxide-based resin, and silicone-based resin.

The content of the microcapsules in the self-healing coating solution according to an embodiment of the present invention may be 5 to 50% by weight, more specifically 10 to 40% by weight, based on the total weight of the coating solution. If the microcapsule is less than 5% by weight based on the total weight of the coating liquid, there may be a problem that sufficient healing does not occur in the damaged area.On the contrary, if the microcapsule exceeds 50% by weight based on the total weight of the coating solution, the adhesion strength of the self-healing coating material There is a problem with falling.

In one embodiment of the present invention for preparing the self-healing coating solution as described above, the method for preparing the self-healing coating solution includes the steps of: (1) preparing a microcapsule containing a mixture of vegetable oil and divinyl compound; (2) Injecting the microcapsules into the composition for forming a matrix and uniformly dispersing.

The present invention also provides a coating material in which the self-healing coating solution is coated on a substrate. The substrate according to an embodiment of the present invention may be one or more materials selected from the group consisting of metal, concrete, ceramic, mortar, plastic, composite material, stone, and wood, but if a material capable of applying a coating solution is specially limited. It is not.

When the above coating material is damaged, the microcapsule breaks from the damaged area, and the healing material flows out, fills the damaged area, and converts it into a viscoelastic material to perform primary healing of the damaged area. Since the viscoelastic healing material is present in the healed part, secondary damage does not occur, so the lifespan is increased compared to the coating material coated with the conventional microcapsule type self-healing coating solution, thereby improving the safety of the base structure and improving the economy. .

The present invention will be described in more detail through examples and experimental examples of the present invention. However, the Examples and Experimental Examples are intended to aid understanding of the present invention and are not intended to limit the scope of the present invention.

<Example 1> Microcapsule synthesis

Into a 100 mL beaker, 5 mL of a 2.5% by weight ethylene-maleic anhydride copolymer aqueous solution and 20 mL of distilled water were put into a constant temperature bath, and mixed while stirring at 25° C. at 2000 rpm using a digital mixer.

Urea 0.503 g, ammonium chloride 0.050 g, and resorcinol 0.050 g were added to the beaker and dissolved. The pH of the contents of the beaker was adjusted to 3.5 while adding aqueous sodium hydroxide and aqueous hydrochloric acid. Whenever bubbles occurred in the contents of the beaker, 2-3 drops of 1-octanol used as an antifoaming agent were added to remove bubbles.

A mixture of 7.20 g of linseed oil and 0.80 g of ethylene glycol dimethacrylate as a core material was slowly added to the beaker to form an emulsion. For stable formation of the emulsion, the beaker was allowed to stand for about 10 minutes, and then 1.456 g of a 37 wt% formaldehyde aqueous solution was added. Thereafter, the temperature of the beaker was slowly increased to 60° C., and a reaction for forming a capsule film was performed for 4.5 hours from the start of the temperature increase. After the reaction was completed, the beaker was taken out of the thermostat, cooled to 25° C., filtered, and washed with water and ethanol to obtain microcapsules. Microcapsules were obtained by natural drying for more than 24 hours, and the average diameter of the microcapsules was measured to be 50 μm.

<Example 2> Preparation of self-healing coating material

The microcapsules prepared in Example 1 were mixed in a weight ratio of 20:80 to the enamel paint, and then the microcapsules were uniformly dispersed to prepare a self-healing coating solution. The coating solution was applied to a silicon wafer and dried at room temperature for 2 days to obtain a self-healing coating material in the form of a coating film. For comparison, a control coating made of enamel paint without adding capsules was also prepared.

<Example 3> Self-healing and secondary damage prevention performance evaluation test

The self-healing coating material and the comparative coating material were damaged using a razor and left to stand for 48 hours to cause a healing reaction. As a result of observing the surface of the comparative coating material with a scanning electron microscope (SEM), it was confirmed that the crack did not heal (FIG. 2A ).

On the other hand, in the self-healing coating material of the present invention, it was confirmed that the healing material flowed out and filled the damaged area to cause self-healing (Fig. 2b).

In addition, the self-healing coating material in which the healing occurred was attached to a vibration tester, and a vibration of 10 to 30 Hz was applied for 1 hour. Even when a strong vibration was applied to the self-healing coating material, it was confirmed that secondary damage did not occur in the healed area (FIG. 2C).

Claims (11)

A polymer composition for forming a matrix; And
As a self-healing coating liquid containing; microcapsules dispersed in the polymer composition and containing a healing material,
Here, the healing substance is a mixture of vegetable oil and a divinyl compound,
The divinyl compound contains 0.1 to 30% by weight with respect to the total weight of the healing material, and when the coating material formed by applying the self-healing coating solution on the substrate is damaged, the microcapsules of the damaged area break and the healing material flows out of the damaged area. A self-healing coating solution that is converted into a viscoelastic material by oxygen after filling.
The method of claim 1,
The vegetable oil is linseed oil, tung oil, rapeseed oil, paulownia oil, soybean oil, dehydrated castor oil, rapeseed oil, sesame oil, perilla oil, cottonseed oil, rice bran oil, soybean oil, and Self-healing coating liquid comprising at least one selected from the group consisting of corn oil.
The method of claim 1,
The divinyl compound is 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, ethylene glycol dimethacrylate, diurethane dimethacrylate, 1,6-hexanediol dimethacrylate, Triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol Ethoxylate diacrylate, bisphenol A ethoxylate diacrylate, bisphenol A propoxylate diacrylate, polyethylene glycol diacrylate, tetra(ethylene glycol) diacrylate, di(ethylene glycol) diacrylate, ethylene It comprises at least one selected from the group consisting of glycol diacrylate, ethylene diacrylate, neopentyl glycol diacrylate, poly(propylene glycol) diacrylate, and tri(propylene glycol) diacrylate. Self-healing coating liquid.
delete The method of claim 1,
The diameter of the microcapsules is 5 to 500 ㎛ self-healing coating solution.
The method of claim 1,
The polymer as the material of the capsule membrane of the microcapsule is a self-healing coating solution that is a polymer selected from the group consisting of urea-formaldehyde polymers, urea-melamine-formaldehyde polymers, and melamine-formaldehyde polymers.
The method of claim 1,
The polymer composition for matrix formation includes enamel paint, acrylic resin, vinyl resin, epoxy resin, chlorinated rubber resin, polyurethane resin, polyester resin, polyacrylate resin, melamine resin, epoxide coating material, poly Self-healing coating liquid containing at least one polymer selected from the group consisting of ester-epoxide resins and silicone resins.
The method of claim 1,
The content of the microcapsules in the self-healing coating solution is 5 to 50% by weight based on the total weight of the self-healing coating solution.
1) preparing a microcapsule containing a mixture of vegetable oil and divinyl compound;
2) Including the step of injecting the microcapsules of step 1) in the composition for matrix formation and uniformly dispersing,
The divinyl compound contains 0.1 to 30% by weight based on the total weight of the healing material, and the self-healing coating solution is a method of producing a self-healing coating solution that is cured by oxygen.
A self-healing coating material prepared by applying the self-healing coating solution of claim 1 on a substrate.
The method of claim 10,
The substrate is a coating material comprising at least one substrate selected from the group consisting of metal, concrete, ceramic, mortar, plastic, composite material, stone and wood.

Images