KR101389496B1 - Powder coating composition having high abrasion resistance and excellent flexibility - Google Patents

Abstract

A powder coating composition having excellent wear resistance and bendability is disclosed. The powder coating composition of the present invention is 10 to 80% by weight epoxy resin, 1 to 50% by weight rubber-modified epoxy resin, 0.1 to 30% by weight curing agent, 0.01 to 1.0% by weight curing aid, 1 to 50% by weight inorganic filler and pigment It consists of 1 to 50% by weight. As a result, by increasing the content of the inorganic filler to improve the wear resistance while including a rubber-modified epoxy resin, it is possible to minimize the deterioration of the bendability and impact resistance, it is possible to improve the physical properties of the epoxy resin as a whole.

Description

Powder coating composition having excellent abrasion resistance and flexibility {POWDER COATING COMPOSITION HAVING HIGH ABRASION RESISTANCE AND EXCELLENT FLEXIBILITY}

The present invention relates to a powder coating composition, and more particularly, to an epoxy resin powder coating composition for pipe coating having excellent wear resistance and flexibility.

Epoxy resin powder coatings have been used to prevent corrosion and improve durability of pipelines buried underground or undersea. However, as the pipe embedding environment becomes harsh, such as the application of directional drilling and rock backfill, it is required to improve the thermal, chemical and physical properties of the epoxy coating to protect the pipe from corrosion.

Gases and oils buried underground go through various environments such as drilling, transportation, storage, and refinery. Until this process, the pipes are transported through pipes such as steel pipes. have.

Accordingly, the pipe coating film needs to protect the base from impact, scratches, and the like, and to prevent corrosion due to contact with moisture and soil. In addition, excellent flexibility is required at the same time to effectively protect the bent pipeline according to the transfer section.

SUMMARY OF THE INVENTION An object of the present invention is to provide an epoxy resin powder coating composition which increases the content of the inorganic filler in order to increase the wear resistance of the epoxy resin powder coating composition and does not reduce the flexibility in forming the coating film.

Powder coating composition having excellent wear resistance and bendability of the present invention for achieving the above object is 10 to 80% by weight epoxy resin, 1 to 50% by weight rubber modified epoxy resin, 0.1 to 30% by weight curing agent, 0.01 to 1.0 curing agent Weight percent, inorganic filler 1-50 weight percent, and pigment 1-50 weight percent.

The epoxy resin is a bisphenol A type epoxy resin having an epoxy equivalent of 400 to 3000, a novolac modified epoxy resin having an epoxy equivalent of 400 to 3000, an isocyanate modified epoxy resin having an epoxy equivalent of 100 to 3000, and a cresol novolac epoxy resin having an epoxy equivalent of 10 to 3000. It may be any one selected from the group consisting of.

The rubber-modified epoxy resin may be a material synthesized by mixing in a weight ratio of bisphenol-A epoxy resin: rubber modified polymer = 95: 5 ~ 40:60.

The rubber modified polymer may be a butadiene polymer or a butadiene-acrylonitrile copolymer.

The rubber-modified epoxy resin may be an epoxy equivalent range of 100 to 1500.

The butadiene polymer or butadiene-acrylonitrile copolymer may be one of which a functional group selected from the group consisting of a carboxyl group, an amino group, a methacrylate group and an epoxy group is bonded to the terminal.

The butadiene-acrylonitrile copolymer may contain 18 to 26% by weight of acrylonitrile based on the butadiene-acrylonitrile copolymer.

The curing agent may be any one selected from the group consisting of a phenolic curing agent, dicyandiamide curing agent, hydrazide curing agent, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride and benzophenone tetracarboxylic anhydride. .

The hardening aid is imidazole, imidazole modified epoxy, dibi oil (1,8-Diazabicyclo [5.4.0] undec-7-ene), dibisulphate (1,8-Diazabicyclo [5.4.0] undec- 7-ene salt), triphenylphosphine and metal chelate may be any one selected from the group consisting of.

The inorganic filler may be at least one selected from the group consisting of feldspar, barium sulphate, silica, alumina hydroxide, titanium dioxide, calcium carbonate, magnesium carbonate, alumina, mica, olastonite and talc.

The powder coating composition may further include a flow improver of 0.1 to 5.0% by weight based on the total weight of the powder coating composition.

The powder particle size of the powder coating composition may be 30 ~ 80㎛.

Since the powder coating composition of the present invention includes a rubber-modified resin, it is possible to improve the physical properties of the epoxy resin by minimizing bendability and impact resistance while improving the wear resistance by increasing the content of the inorganic filler.

Hereinafter, the powder coating composition of the present invention will be described.

The powder coating composition of the present invention is 10 to 80% by weight epoxy resin, 1 to 50% by weight rubber modified epoxy resin, 0.1 to 30% by weight curing agent, 0.01 to 1% by weight curing aid, 1 to 50% by weight inorganic filler and pigment It consists of 1 to 50% by weight.

As the epoxy resin, bisphenol A-type epoxy, novolac-modified epoxy resin, isocyanate-modified epoxy resin, cresol novolac epoxy resin and the like can be applied.

The bisphenol A-type epoxy resin may be an epoxy equivalent of 400 to 3000, it is more preferable to use an epoxy equivalent of 400 to 1500 in order to ensure flexibility, corrosion resistance and manufacturing workability.

The novolac-modified epoxy resin can be used an epoxy equivalent of 400 to 3000, it is more preferable to use an epoxy equivalent of 400 to 1500 in order to improve flexibility, corrosion resistance and manufacturing workability.

The isocyanate-modified epoxy resin may be an epoxy equivalent of 100 to 3000, more preferably 200 to 1000 can be used.

The cresol novolac epoxy resin may be an epoxy equivalent of 10 to 3000, more preferably 10 to 1000 can be used.

As described above, the epoxy resin is used in the range of 10 to 80% by weight, and if it is smaller than the above range, the mechanical properties may be lowered, and if it is larger than the above range, the corrosion resistance may be lowered.

The rubber modified epoxy resin is obtained by synthesizing a bisphenol A-type epoxy resin and a rubber modified polymer. The rubber-modified polymer may be used alone, but may be used in a form synthesized with the bisphenol A-type epoxy resin because the workability may be decreased during coating dispersion when used alone.

Preferably, the bisphenol-A epoxy resin: rubber modified polymer = 95: 5 ~ 40: 60 can be used in the form of a mixture by mixing in a weight ratio. It is preferable that the said rubber modified epoxy resin is 100-1500 in epoxy equivalent range.

The rubber modified polymer may be a butadiene polymer or a butadiene-acrylonitrile copolymer, and the butadiene polymer or butadiene-acrylonitrile may have a terminal functional group. For example, CTBN (Carboxyl Terminated Butadiene Acrylonitrile) having a carboxyl group as a functional group, ATBN (Amine Terminated Butadiene Acrylonitrile) having an amine group as a functional group, in addition to a methacrylate, a rubber modified polymer having an epoxy functional group. At this time, the rubber modified polymer is preferably contained in the rubber material 20 to 30% by weight.

Chemical structures of the CTBN and chemical structures of the ATBN are shown in the following Chemical Formulas 1 and 2, respectively.

Such a rubber-modified polymer is formed with appropriate solubility, glass transition temperature, viscosity, etc. according to the acrylonitrile content, the content is 0 to 40% by weight.

The higher the content of acrylonitrile, the higher the solubility, the resistance to oil and the glass transition temperature of the rubber-modified polymer, but the lower the content of acrylonitrile, the lower the moisture resistance. Therefore, it is preferable to synthesize | combine it to bisphenol A type epoxy resin using the rubber modified polymer containing 18-26 weight% of acrylonitrile.

The rubber-modified epoxy resin according to the composition affects the impact properties, the peel adhesion strength and the tensile shear bond strength, it can improve the wear resistance and bendability when applying the paint.

As described above, the rubber-modified epoxy resin is preferably used 1 to 50% by weight, when used below the above range, the wear resistance and bendability synergistic effect may be reduced.

The curing agent may be a phenol-type curing agent, dicyanamide-based curing agent, hydrazide-based curing agent, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetra carboxylic anhydride and the like, more preferably, A phenolic hardening | curing agent or the dicyandiamide type hardening | curing agent can be used.

As described above, the curing agent is preferably used 0.1 to 30% by weight based on the total weight of the powder coating composition, the mechanical properties may be lowered if out of the above range.

The curing aids are imidazoles, imidazole modified epoxy, dibi oil (1,8-Diazabicyclo [5.4.0] undec-7-ene), dibi salts (1,8-Diazabicyclo [5.4.0] undec-7 -ene salt), triphenylphosphine, metal chelate and the like can be applied.

As described above, the curing aid is preferably included in an amount of 0.01 to 1% by weight based on the total weight of the powder coating composition, the mechanical properties may be reduced when out of the range.

The inorganic filler may be any one or a mixture of two or more selected from feldspar, barium sulfate, silica, alumina hydroxide, titanium dioxide, calcium carbonate, magnesium carbonate, alumina, mica, olastonite and talc.

As described above, the inorganic filler is preferably included 1 to 50% by weight based on the total weight of the powder coating composition, if outside the above range may be reduced mechanical properties or flexibility.

The pigment may be applied to all pigments commonly used in pipe powder coating, and, in the case of a white pigment, it is preferable to use titanium dioxide.

The content of the pigment is preferably 1 to 50% by weight as described above, if outside the range of the content, the hiding power of the coating film to which the powder coating composition of the present invention is applied may not be sufficiently secured.

In addition to the components of the powder coating composition, necessary materials may be further added according to the use purpose and environment of the powder coating.

The powder coating composition may further include a flow improver of 0.1 to 5.0% by weight based on the total weight of the composition. If it is out of the above range, the flowability may be deteriorated.

The flow improver may be an acrylic flow improver, a silicone flow improver, or the like, and by using a flow improver to prevent cracking and improve surface tension to improve the appearance of the coating using the paint. have.

In addition, dispersants such as amide, polypropylene, olefin, and teflon waxes may be further added to facilitate smooth dispersion during powder coating.

In addition, a flow improver may be further added to prevent clogging in the powder coating device and to improve fluidity. As the fluidity improving agent, polypropylene wax, hydrophilic or hydrophobic silica may be used in a usual amount of use.

It is preferable that the powder coating composition of this invention exists in the range of 30-80 micrometers in average particle size of the powder which comprises a coating material.

Hereinafter, a method of preparing a powder coating composition having excellent wear resistance and flexibility of the present invention.

First, the ingredients of the powder coating composition are blended using a container mixer and uniformly mixed.

Next, the mixed composition is melt mixed through a kneader or an extruder at 80 to 120 ° C., and then powder powder having an average particle size of 30 to 80 μm may be manufactured using a grinder. have.

The coating film formation method using the powder coating composition of this invention coats the powder coating composition of this invention 200-500 micrometers thick with the electrostatic spray spraying machine, while preheating a pre-blasted steel pipe to 180-250 degreeC. Thereafter, the substrate may be heated to 180 to 250 ° C. to form a post heating film, and may be left in air to form a coating film.

Hereinafter, a preferred embodiment of the powder coating composition having excellent wear resistance and flexibility of the present invention will be described.

Components (brand name and content) constituting the powder coating composition according to Example 1 are as follows.

Epoxy Resin: Bisphenol A epoxy resin, Epoxy equivalent 900 (KCC), 90g

Rubber modified epoxy resin: AlK84L (CV), 10g

Curing agent: 1400 F (air product), 2 g

Curing Aid: 2-M (Shikoku), 1.5g

Inorganic Filler: FM200 (Grade Material), 80g

Colored Pigment: Biperox 130M (Bayer), 5g

Flow improver: PLP-100 (KS Chemical), 0.5g

The components of the powder coating composition according to Example 2 were the same as those of Example 1, except that 55g of epoxy resin, 45g of rubber epoxy resin, and 90g of inorganic filler were used.

The components of the powder coating composition according to Example 3 were the same as those of Example 1, except that 20g of epoxy resin, 80g of rubber epoxy resin, and 100g of inorganic filler were used.

Comparative Example 1

Component of the powder coating composition according to Comparative Example 1 excluded the rubber-modified epoxy resin from the component of the composition of Example 1. The remaining components were all the same. In addition, 100g was used for the epoxy resin.

[Comparative Example 2]

The components of the powder coating composition according to Comparative Example 2 were the same as the components of the composition of Comparative Example 1, except that 70 g of an inorganic filler was used.

[Comparative Example 3]

The components of the powder coating composition according to Comparative Example 3 were the same as those of the composition of Comparative Example 1, except that 40 g of an inorganic filler was used.

[Comparative Example 4]

The components of the powder coating composition according to Comparative Example 4 were the same as the components of the composition of Comparative Example 1, except that 30 g of an inorganic filler was used.

Test Example  One: Flexibility  exam

In order to fabricate a test specimen for flexibility, 25 mm (width) × 300 mm (length) × 6 mm (thickness) steel was prepared, and grit blasting surface treatment was performed.

After preheating the surface-treated steel to 230 ℃, the coating thickness of the powder coating composition according to Examples 1 to 3, Comparative Examples 1 to 4 by the electrostatic spray method on the surface of the steel 200 ~ 500㎛ It was painted so as to prepare a specimen.

Thereafter, the temperature of the specimen was set to -30 ° C., and the crack of the coating film was measured when the specimen was bent using a mandrel having an angle of 3 ° to the pipe diameter. Here, the specimen preparation and the property evaluation method was performed according to CSA Z245.20, the Canadian standard for pipes.

Test Example  2: wear resistance test

Specimens for abrasion resistance test were prepared in the same manner as in Test Example 1, except that steel was prepared in a circular shape having a diameter of 100 mm and a hole in the center.

Thereafter, the specimens were polished by 500 cycles of 10 cycles of CS 17 wheels mounted on an automatic polishing machine, and then tested by a method of measuring the difference in weight after polishing from the initial weight. At this time, the test was performed according to ASTM D4060.

Table 1 summarizes the components of the powder coating compositions according to Examples 1 to 3 and Comparative Examples 1 to 3, and the results according to Test Examples 1 and 2.

Constituent
(Unit: g) Example Comparative Example One 2 3 One 2 3 4 Furtherance Epoxy resin 90 55 20 100 100 100 100 Rubber modified epoxy resin 10 45 80 Hardener 2 2 2 2 2 2 2 Hardening
Supplements 1.5 1.5 1.5 1.5 1.5 1.5 1.5 weapon
filling 80 90 100 80 70 40 30 Colored
Pigment 5 5 5 5 5 5 5 Flowability
Enhancer 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Properties Abrasion resistance Great Great Great Great Great Poor Poor Flexibility Good Good Good fracture fracture Good Good

According to Table 1, the powder coating composition according to Examples 1 to 3 of the present invention in which the rubber-modified epoxy resin was introduced was found to have excellent wear resistance compared to Comparative Examples 3 and 4 having a relatively low content of the inorganic filler. On the other hand, the content of the inorganic filler was relatively high, but it was confirmed that the flexibility is excellent compared to Comparative Examples 1 and 2 do not include a rubber-modified epoxy resin.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It is possible.

Claims (12)

Abrasion resistance consisting of 10 to 80% by weight of epoxy resin, 1 to 50% by weight of rubber-modified epoxy resin, 0.1 to 30% by weight of curing agent, 0.01 to 1.0% by weight of curing aid, 1 to 50% by weight of inorganic filler, and 1 to 50% by weight of pigment In the powder coating composition having a flexible property,
The above-
Selected from the group consisting of bisphenol A type epoxy resins having an epoxy equivalent of 400 to 3000, a novolac modified epoxy resin having an epoxy equivalent of 400 to 3000, an isocyanate modified epoxy resin having an epoxy equivalent of 100 to 3000 and a cresol novolac epoxy resin having an epoxy equivalent of 10 to 3000 Which one,
The rubber modified epoxy resin,
Bisphenol-A epoxy resin: Rubber modified polymer = a material synthesized by mixing in a weight ratio of 95: 5 ~ 40:60,
The curing agent is a phenol-based curing agent or dicyanamide-based curing agent, characterized in that the powder coating composition for pipe coating having abrasion resistance and flexibility.
delete delete The method according to claim 1,
The rubber modified polymer,
Powder coating composition for pipe coating which has abrasion resistance and bendability which is a butadiene polymer or a butadiene-acrylonitrile copolymer.
The method according to claim 1,
The rubber modified epoxy resin,
Powder coating composition for pipe coating which has abrasion resistance and bendability which is the epoxy equivalent range 100-1500.
The method of claim 4,
The butadiene polymer or butadiene-acrylonitrile copolymer,
Powder coating composition for pipe coating having wear resistance and bendability, characterized in that any one functional group selected from the group consisting of carboxyl group, amino group, methacrylate group and epoxy group is bonded to the terminal.
The method of claim 4,
The butadiene-acrylonitrile copolymer,
Powder coating composition for pipe coating having abrasion resistance and bendability, characterized in that containing 18 to 26% by weight of acrylonitrile based on the total weight of the butadiene-acrylonitrile copolymer.
delete The method according to claim 1,
The above-
Powder coating composition for coating a pipe having wear resistance and bendability, characterized in that any one selected from the group consisting of imidazoles, imidazole modified epoxy, di oil, di oil salt, triphenyl phosphine and metal chelate.
The method according to claim 1,
The inorganic filler,
Feldspar, barium sulfate, silica, alumina hydroxide, titanium dioxide, calcium carbonate, magnesium carbonate, alumina, mica, olestonite and talc at least one selected from the group consisting of pipe coating powder having abrasion resistance and flexibility Paint compositions.
The method according to claim 1,
The powder coating composition,
Pipe coating powder coating composition having abrasion resistance and bendability, characterized in that it further comprises a flow improver of 0.1 to 5.0% by weight based on the total weight of the powder coating composition.
The method according to claim 1,
Powder particle size of the powder coating composition,
Powder coating composition for pipe coating which has abrasion resistance and bendability which is 30-80 micrometers.