KR101371583B1 - Method for manufacturing stone chip coated steel tile - Google Patents

Abstract

According to the present invention, the method for manufacturing a metal roof tile coated with a mineral matter includes: a step of forming a metal base plate by using a metal plate material (a); a step of forming a mineral coating layer on a surface of a metal base plate by attaching a mineral matter to a surface of the metal base plate coated with a primer adhesive (b); a step of coating the mineral coating layer with a top coating adhesive (c); and a step of curing the mineral coating layer formed on the base plate by heating the mineral coating layer (d). The primer adhesive is an aqueous acrylic-based adhesive including 2-Ethyl hexyl acrylate (2-EHA) and Methyl Metha Acrylate (MMA) as a main monomer, surfactants, and half of N-Methylol acrylamide (N-MAM-P) and Phosphate group as a functional monomer. The top coating adhesive is an aqueous acrylic-based adhesive including Styrene as a main monomer, Butyl acrylate (BA) and Acrylonitrile (AN), and half of N-Methylol acrylamide (N-MAM-P) as a functional monomer. the present invention can manufacture a metal roof tile to have excellent quality and long service life by using the primer adhesive and the top coating adhesive with excellent properties. [Reference numerals] (S10) Forming a metal base plate; (S20) Attaching a mineral matter to a metal base plate using primer adhesive; (S30) Applying top coating adhesive on a mineral coating layer formed on the metal base plate; (S40) Heating and curing the mineral coating layer coated with the top coating adhesive

Description

Method for manufacturing metal tile coated with minerals {Method for manufacturing stone chip coated steel tile}

The present invention relates to a method of manufacturing a metal roof, and more particularly, to a method of manufacturing a metal roof coated with a mineral formed by coating a metal base plate with a mineral such as stone powder.

Metal roof tile is a building material used for finishing roofs of houses. The metal tile is manufactured by folding a metal plate into a shape of or close to a tile to form a metal base plate, and coating the anticorrosive coating on the surface with mineral particles.

In addition to the metal roof, the building materials used for finishing the roof include traditional roof tiles and asphalt shingle. Ojigiwa is made by drying clay and baking it at a high temperature of about 1,200 ℃. It has virtually no deformation even in severe climate change and has high energy efficiency. However, there is a disadvantage that the tile is heavy, fragile, and expensive to manufacture. Asphalt shingle is a roofing material in which asphalt is impregnated in asphalt felt and then melted with inorganic glass fiber, and pigmented with mineral powder or colored rut. The asphalt shingle has a problem of bending or rolling due to lack of strength of the glass fiber mat at the center and curling, cracking, splitting, and the like. Also, it is fragile due to loss of shrinkage expansion ability due to external temperature change and hardening phenomenon due to solar heat and temperature change. Furthermore, the tillage and asphalt shingle have a short durability and are difficult to dispose of due to the generation of environmental waste when repairing or replacing.

Due to the shortcomings of the existing roofing materials, in the recent roofing materials market, there is a growing interest in long metal roof tiles that can be recycled, environment-friendly and durable for more than 20 years. In addition, the metal tile is economical, durable, and easy to construct, and its market size is increasing by more than 20% every year in the world. In Korea, sales are increasing with the recent increase in the number of rural homes. Such metal tiles are disclosed in Korean Unexamined Utility Model Publication No. 2010-0001625 (published on Feb. 06, 2010).

Typically, the metal tile is formed into a tile shape using a press or the like, and coated with a mineral base such as stone powder on the metal base plate using an adhesive solution, and then cured at a high temperature to finish it. When the mineral material is adhered to the metal base plate, the undercoat adhesive and the topcoat adhesive are used. The undercoat adhesive is applied to the metal base plate to attach the mineral to the metal base plate. Cover and hold the mineral on the plate.

In the manufacture of metal tiles, the top coat liquid is not easily applied to the minute portions between the uneven mineral particles constituting the mineral coating layer. When moisture penetrates into the minute portions between the mineral particles that are not coated with the top coat adhesive, the bottom coat adhesive is used in combination with the filler, so that the filler absorbs the moisture and an interface between the metal base plate and the adhesive liquid occurs. When the expansion and contraction phenomenon between the metal base plate and the adhesive liquid is repeated due to the temperature difference after the interface between the metal base plate and the adhesive liquid occurs, the interface between the metal base plate and the adhesive liquid is separated and the mineral coating layer is peeled off from the metal base plate. Will occur.

The present invention has been made in view of this point, and an object of the present invention is to stably form a mineral coating layer made of a mineral on a metal base plate to improve the quality of the product, and to reduce the energy consumption to reduce the manufacturing cost It is to provide a method for producing the coated metal tile.

In order to achieve the above object, the present invention provides a method of manufacturing a metal tile coated with minerals, comprising the steps of: (a) forming a metal base plate using a metal plate, and (b) adhering to the surface of the metal base plate. Forming a mineral coating layer on the surface of the metal base plate by applying a liquid and attaching a mineral thereto; (c) applying a top coat adhesive solution on the mineral coating layer; and (d) the metal base plate. And curing the mineral coating layer by applying heat, wherein the undercoat adhesive includes 2-ethylhexyl acrylate (2-EHA; 2-Ethyl hexyl acrylate) and MMA (Methyl Metha Acrylate) as a main monomer, and a surfactant. And, an aqueous acrylic adhesive liquid containing N-MAM-P (N-Methylol acrylamide, 50%) and a phosphate group-containing monomer as a functional monomer, and the top coating liquid is styrene (Styrene) as a main monomer. BA (Bu tyl acrylate) and AA (Acrylic acid), and an aqueous acrylic adhesive liquid containing N-MAM-P (N-Methylol acrylamide, 50%) as a functional monomer.

In the curing process of step (d), the curing temperature is maintained at 50 ° C. for 5 minutes, then at 70 ° C. for 120 minutes, and then at 140 ° C. for 10 minutes to cure the mineral coating layer. .

The method for producing a mineral-coated metal tile according to the present invention includes 2-ethylhexyl acrylate (2-EHA) and methyl methacrylate (MMA), which are main monomers, and acrylic acid (AA), which is a functional monomer that improves heat resistance and cohesion. , An N-methylol acrylamide (N-MAM-P) that improves the degree of crosslinking, and a melamine-based resin that is an additive, and has an excellent adhesive strength, stability, accelerated weather resistance, moisture resistance, and heat resistance compared to conventional undercoat adhesives. And a non-ionic surfactant, acrylic acid (AA), itaconic acid (IA), and a fluorine-based water repellent, and have a white turbidity, mineral loss, accelerated weather resistance, moisture resistance, and water repellency compared to conventional undercoat adhesives. By coating a mineral material on the metal base plate by using, it is possible to produce a metal tile with excellent quality and long life.

In addition, the method of manufacturing a mineral coated metal tile according to the present invention uses an improved undercoat adhesive and a topcoat adhesive, and cures the mineral coated on the metal base plate for a shorter time at a lower curing temperature than in the prior art. By doing so, the quality of the product can be improved compared to the conventional one, and the energy consumption in the curing process can be greatly reduced, thereby reducing the manufacturing cost.

In addition, the manufacturing method of the metal tile coated with the mineral material according to the present invention is environmentally friendly by reducing the emission of carbon or environmental pollutants during manufacturing by using less fuel such as electricity, kerosene, LPG in the curing process.

1 illustrates a step of manufacturing a metal tile using a method of manufacturing a metal tile coated with a mineral according to an embodiment of the present invention.
2 shows a curing temperature control program in a conventional curing process.
Figure 3 shows an optimized curing temperature control program in the curing process of the manufacturing method of the mineral-coated metal tile according to an embodiment of the present invention.
Figure 4 shows the wear loss change graph according to the number of years of construction of the metal roof derived from the average wear loss of the collected on-site construction metal tiles and samples.
FIG. 5 is a graph illustrating a change in wear loss according to the number of construction years of metal tiles estimated from the graph of FIG. 4.
FIG. 6 shows a graph showing a change in wear loss of metal tiles according to accelerated deterioration time derived through surface mineral loss test.
Figure 7 shows the wear resistance tester used in the wear test by KS L 1001.
FIG. 8 is a graph showing a change in wear loss according to accelerated deterioration time derived from data obtained through abrasion resistance test using the abrasion resistance tester shown in FIG. 7.
Figure 9 shows a graph of the correlation analysis between the change in wear loss according to the years of installation of the field construction sample and the change in wear loss according to the years of installation obtained through the wear test.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a method of manufacturing a metal tile coated with a mineral according to the present invention.

In describing the present invention, the sizes and shapes of the components shown in the drawings may be exaggerated or simplified for clarity and convenience of explanation. In addition, terms that are specifically defined in consideration of the configuration and operation of the present invention may vary depending on the intention or custom of the user or operator. These terms are to be construed in accordance with the meaning and concept consistent with the technical idea of the present invention based on the contents throughout the present specification.

1 illustrates a step of manufacturing a metal tile using a method of manufacturing a metal tile coated with a mineral according to an embodiment of the present invention.

As shown in FIG. 1, a method of manufacturing a metal tile coated with a mineral according to an embodiment of the present invention includes a metal base plate forming step (S10), a mineral attaching step (S20) using a bottom coating liquid, and a metal. The coating liquid coating process (S30) for the mineral coating layer formed on the surface of the base plate, and the curing process (S40) by applying heat to the mineral coating layer coated with the coating liquid. Curing process is a process of curing the adhesive liquid, the adhesive liquid is cured by a cross-linking reaction that forms a complete chemical bond, such as a covalent bond or an ionic bond between molecules and molecules through heating. The metal base plate is manufactured by pressing a metal plate such as galvalume (aluminum 55% + 45% zinc) plated steel sheet, and as the mineral material, stone powder coated with a pigment of volcanic stone powder may be used.

In mineral coated metal roof tiles, whether or not the mineral coating layer is peeled off after being applied to a roof or an exterior wall of a building is an important evaluation factor in evaluating the quality of a product. In order to stably attach the mineral to the surface of the metal base plate, the use of an adhesive liquid and a curing process are important. According to the present invention, a method of manufacturing a metal-coated mineral tile according to the present invention improves the quality of a product by improving a curing process, together with an improvement on an undercoat adhesive and a topcoat adhesive for attaching a mineral to a metal base plate surface. It can increase the reliability and reduce the manufacturing cost.

As described above, the adhesive liquid for attaching the mineral to the metal base plate includes a bottom coat adhesive liquid and a top coat adhesive liquid. Since the adhesive solution is applied to the surface of the metal base plate to fix the mineral to the metal base plate, a strong adhesive force between the metal base plate and the mineral is required, and should have a property of curing at high temperature. Since the top coat adhesive is for preventing the separation of minerals and improving the water resistance, adhesion and water resistance with the minerals are required, and the top adhesive liquid must have a characteristic that does not change with external environments such as cold and cold.

First, since the base adhesive has strong adhesive strength between the metal base plate and the mineral, it is an important physical property. Therefore, an acrylic main monomer which determines the type and appropriate content of the surfactant which is exposed to the surface during drying and adversely affects the physical properties ( It is important to select monomers, to apply small amounts, but to select and apply functional monomers, functional monomers and additives that affect drying time, degree of cure, heat resistance and adhesion.

Cohesion between dissimilar materials is affected by differences in chemical electronegativity (polarity) and surface tension. Since the steel plate is generally a material having a polarity, when the aqueous emulsion adhesive applied to the adhesive is nonpolar, the adhesive strength is reduced compared to the polar adhesive. Applicant has applied a functional acrylic monomer having a polarity containing a phosphate group (Phosphate group) to improve the adhesion to the metal, glass, and inorganic materials by making the polarizer to the polarizer. In addition, by appropriately selecting the type and composition ratio of the components constituting the undercoat adhesive solution to prepare a sample of the undercoat adhesive of various compositions, by performing a variety of tests on the prepared undercoat adhesive sample, the high adhesion force while working at a low temperature An undercoat adhesive liquid having an optimum composition ratio exerted was developed.

In the case of the top coat adhesive, after the mineral is coated on the bottom coat, the adhesive is applied to prevent the separation of the mineral and to improve the water resistance. Such top coat adhesives should have high adhesiveness and water resistance to minerals, and have no characteristic of leaving and turbidity of minerals due to external environment such as moisture, cold and heat.

Here, the clouding phenomenon is a phenomenon in which the color of the mineral substance adhering to the surface of the metal packaging material is partially deformed to white, which is a factor that inhibits the aesthetics of the metal group. The clouding phenomenon occurs when a surfactant, which is a low molecular material necessarily applied for dispersion polymerization of water and an acrylic monomer, is exposed to the surface after drying in an aqueous emulsion adhesive liquid, which is a top coat adhesive liquid, and comes into contact with external moisture. In addition, due to this effect, the top coat adhesive partially loses the adhesive strength, thereby increasing the amount of mineral loss. Therefore, in the production of a top coat adhesive liquid, it is important to select an acrylic monomer capable of improving water resistance, weather resistance and adhesion to minerals and to determine the content thereof. In addition, by adding a water-repellent agent and the like excellent in weather resistance to reduce the surface tension it is necessary to prevent contact with moisture to improve the prevention of turbidity and adhesion.

Applicant prepared a top coat adhesive sample of various compositions by appropriately selecting the type and composition ratio of the components constituting the top coat adhesive liquid, and after performing various tests on the prepared top adhesive liquid sample, excellent water resistance and cold resistance And, an environmentally friendly aqueous acrylic topcoat adhesive was developed.

The bottom coat liquid sample and the top coat liquid sample were prepared using emulsion radical polymerization. Radical polymerization is largely classified into four types: bulk polymerization, solution polymerization, emulsion polymerization and suspension polymerization. Among them, the emulsion polymerization method is a method of thermal polymerization using water, an acrylic monomer (oil), an initiator, and a surfactant, and disperses water and an acrylic monomer in the form of particles without separating them to prepare an adhesive liquid which is a polymerized product in the particles. That's how. Therefore, unlike other polymerization methods, since the base is water, there is no risk of explosion, and it is environmentally friendly, harmless to human body.

The manufacturing process of the undercoat adhesive sample is briefly described as follows. Distilled water was added to a 2-liter five-necked flask and stirred while distilled water and 2-ethylhexyl acrylate (2-EHA), butyl acrylate (BA), methyl methacrylate (MMA), and styrene (SM) acrylate ester system In order to form particles of acrylic acid (AA), methacrylic acid (MAA), which are monomers containing monomers and carboxyl groups, and functional monomers, micelles (Micell), which are polymerization sites, a surfactant was added and stirred at a high speed to prepare an emulsion. The prepared emulsion was mixed with distilled water in a 2-liter five-necked flask with a polymerization initiator of ammonium persulfate and sodium bisulfite at 80 to 84 ° C. for about 3 hours, and then The polymerization was time aging. After aging, the temperature was cooled to 40 ° C. or lower, and ammonium hydroxide (NH ₄ OH) was added to adjust the acidity. After stirring, an antifoaming agent and an additive were added to improve product properties and stability to prepare an aqueous acrylic coating solution.

Table 1 below shows the components and composition ratios for the prepared adhesive solution samples.

After preparing the adhesive sample as described above, Lab test was performed on the samples of the bottom coat adhesive shown in Table 1 above to find the optimum composition ratio of the bottom coat adhesive that exhibits high adhesion while operating at low temperature. Proceeded. Lab testing proceeded as closely as possible to the module production process. That is, calcium carbonate, pigment, and paint, which are given for adhesion and workability, are added to each prepared undercoating solution sample by adding the same amount as in the production process as shown in Table 2, and then a metal base for metal tile. Test samples were prepared by attaching minerals to the plates and comparing them with physical properties.

Specific physical property comparison experiment was carried out in the following way. After drying for 30 minutes at a drying temperature of 100 ℃ and curing the drying temperature for 30 minutes at 160 ℃ by increasing the drying temperature by 5 ℃ every 5 minutes, soaked in boiling water of about 80 ℃ for 1 hour and scraped with a metal piece to compare the adhesive strength. In addition, the crosslinking temperature was lowered from 130 ° C. to 140 ° C. in order to reduce raw materials and shorten the curing time of the drying furnace.

The test results showed that 2-ethylhexyl acrylate (2-EHA), methyl methacrylate (MMA), the main monomers that are highly involved in adhesion, and acrylic acid (AA), a functional monomer that improves heat resistance and cohesion, and N, which improves the degree of crosslinking -Samples of the adhesive coating solution using methylol acrylamide (N-MAM-P) had better adhesion between the metal base plate and the mineral compared to the conventional products, but the cohesiveness was not good, causing cohesive failure when scratched with metal pieces. Occurred. When butyl acrylate (BA), styrene (SM) and methacrylic acid (MMA) were used as main monomers to improve cohesion, cohesion was good, but the adhesion was poor.

As a result, it was evaluated that it is desirable to adjust the monomer 2-ethylhexyl acrylate (2-EHA) to 20% and methyl methacrylate (MMA) to around 22% to improve adhesion and cohesion. In addition, acrylic acid (AA) is used alone as methacrylic acid (MAA) as the functional monomer, but it is evaluated that acrylic acid (AA) is preferably applied in an amount of 1 to 2% in consideration of viscosity increase and polymerization exotherm. . In the case of the surfactant, when the particle size is 3% or more, the particle size decreases and the drying property and the water resistance deteriorate. Therefore, it is evaluated that the application is within 2.5% in consideration of the stability over time. In addition, when the monomer-b, which is a crosslinking monomer which crosslinks at a relatively low temperature, is applied, the crosslinking temperature is slightly improved, but the degree of polymerization is poor, and thus the adhesive strength is not good at heat resistance, and the viscosity increases when the content is increased (2% or more). It was evaluated that the application of N-methylol acrylamide (N-MAM-P) at about 1.5% was advantageous in terms of stability and adhesion.

In addition, when the monomer-a containing the phosphate group is applied to improve the adhesion, the adhesion is improved, but it is preferable to limit the content to within 0.5% because the stability of the product is impaired due to the increase in viscosity over time and the destruction of micelles. Was evaluated. In addition, when melamine resin is used as an additive, increasing its content shows good adhesion even at low crosslinking temperature (140 ℃), but when used excessively, the surface becomes too hard, causing problems of mineral loss. It was evaluated that it was desirable to limit the content to within 1.5%.

The final evaluation results can be summarized in Table 3 below. In the following [Table 3], the adhesive force represents the adhesive force between the metal base plate and the undercoating adhesive sample, and the crosslinking temperature represents the degree of cohesion of the adhesive sample under the crosslinking reaction. Stability is the stability of the test sample after the crosslinking reaction at 140 ° C., which indicates whether there is a swelling phenomenon of the test sample after the crosslinking reaction.

(×: poor, △: medium, ○: good, ◎: very good)

Table 3 shows that the undercoat adhesive sample # 8 has the most excellent properties as the undercoat adhesive. That is, the preferred undercoating solution is 52.1% of distilled water, 2.0% and 0.4% of Anion (Sodium lauryl sulfate) and Nonion (NP free type), which are surfactants, and APS (Ammonium persulfate) as an initiator, respectively. ) And SBS (Sodium metabisulfate) were 0.2% and 0.1%, respectively, and 2-ethylhexyl acrylate (2-EHA; 2-Ethyl hexyl acrylate) and methyl methacrylate (MMA) were 19.4 as main monomers, respectively. % And 21.3%, N-MAM-P (N-Methylol acrylamide, 50%) as functional monomer and 1.5% and 0.5% as Monomer-a, respectively, and acrylic acid (AA; Acrylic acid) is 1.5%, antifoaming agent 0.1%, ammonium hydroxide (NH ₄ OH) 0.8%, additives containing 1% acrylic adhesive. Herein, the monomer-a, which is a functional monomer, is a phosphate group-containing monomer, and the phosphate group has a polarity to the acrylic monomer, thereby increasing adhesion to metals, glass, and inorganic materials. And the additive is melamine resin (Melamine resin), which serves to strengthen the adhesive strength of the adhesive and the metal base plate and lower the surface strength of the adhesive when the crosslinking temperature is lowered.

In addition, the accelerated weathering test, the moisture resistance test, and the heat resistance test for each coat of adhesive samples showed that the coat of the sample # 8 had better performance than the other samples.

Accelerated weathering test is a test for verifying the product's environmental resistance performance by rapidly deteriorating materials by realizing harsh environmental conditions by controlling artificial light sources such as UV lamps and temperature and humidity conditions. For the accelerated weathering test of the samples, the method specified in Korean Industrial Standard KS F 4751 was used. That is, the test samples were continuously irradiated with light in the wavelength range of 300 to 700 nm at a black panel temperature of 63 ± 3 ° C. using a sunshine ± 255% ± 10% W / m 2 using a Sunshine Carbon Arc Weathermeter. At this time, the light irradiation was performed by simultaneously performing a water spray and light irradiation for 18 minutes after 102 minutes light irradiation. After the test, the result was judged by visually confirming whether the sample was discolored, cracked, or swollen before and after the test.

Moisture resistance test is a test to check the water resistance of the product and the resistance to turbidity under high temperature and humidity conditions by controlling temperature and humidity. The method specified in Korean Industrial Standard KS F 4751 is the same as the accelerated weathering test. Evaluation was carried out by applying. The evaluation was carried out by accommodating the test sample in a constant temperature / humidity temperature of 49 ± 1 ° C. and a relative humidity of 95% or more for the evaluation time, and then visually confirming whether the sample was discolored, cracked, or swollen.

The heat resistance test is a test to check the resistance to high temperature, which is an essential evaluation in building exterior materials, and after accepting the sample in the hot air dryer for the evaluation time, visually inspecting whether the sample is discolored, cracked, or swollen before and after the test. Confirmed.

Hereinafter, the development process of an environmentally friendly aqueous acrylic top coat adhesive liquid will be described.

The process of preparing the top coat adhesive sample to find the optimum component and composition ratio is similar to the process of preparing the bottom coat adhesive sample described above. Distilled water and 2-ethylhexyl are added to the emulsification tank while stirring with distilled water in a 2-liter 5-neck flask. 2 or more types of acrylic ester monomers of acrylate (2-EHA), butyl acrylate (BA), methyl methacrylate (MMA), styrene (SM) and acrylonitrile (AN), containing a carboxyl group which is a functional group The acrylic acid (AA), itaconic acid (IA), etc. which are a monomer, some functional crosslinking monomers, and surfactant were added, and the mixture was stirred at high speed to prepare an emulsion. The prepared emulsion was thermally polymerized in a 2 L five-neck flask with a polymerization initiator of ammonium persulfate and sodium bisulfite at a temperature of 80 to 84 ° C. for about 3 hours, and then aged for 2 to 3 hours. After cooling, an aqueous acrylic adhesive liquid was prepared using ammonium hydroxide (NH ₄ OH), a polyester antifoaming agent, and an additive.

  The top coat adhesive is applied over the mineral fixed with the bottom coat adhesive to prevent the loss of adhesion of the metal base plate and the mineral. Therefore, the top coat adhesive is most likely to be affected by the external environment when the metal tile is installed outdoors, the cohesive force of the adhesive solution itself is excellent in the weather resistance, there should be no clouding phenomenon in the moisture.

Table 4 below shows the constituents and composition ratios for the prepared adhesive solution samples.

After preparing the top coat adhesive sample as described above, the top coat adhesive shown in Table 4 above to find the optimal composition ratio of the top coat adhesive which is excellent in cohesion and strong in weather resistance and hardly cloudy due to moisture. Physical property tests were performed on the samples. To test the physical properties of the top coat adhesive, a mineral material was attached to the metal base plate for metal tile using the bottom coat adhesive, and the top coat adhesive sample was sprayed twice at a distance of 20 cm with an atomizer. In this case, a galvalume steel sheet (melted 55% aluminum zinc alloy plated steel sheet, KS D 3770) was used as the metal base plate, and mineral powder was used as the stone powder colored with volcanic stone. Was used.

The test sample thus made was dried at 140 ° C. for 5 minutes or 160 ° C. for 4 minutes and then soaked in tap water for 1 to 2 days at room temperature. Thereafter, the loss of minerals and turbidity of each test sample were compared with the existing products, and the loss of minerals and cloudiness at room temperature were compared after experiments at -20 ° C for 24 hours in a cold test.

As a result of the test, when comparing the turbidity phenomenon and mineral loss, the application of the surfactant to the nonion alone was less than the application of Anion, but when the content was too small, the amount of micelle particles was insufficient. It was evaluated that it was desirable to limit the content to about 0.8 to 1.5%. In the case of functional monomers and functional monomers applied to improve adhesion and crosslinking degree, the functional monomers are about 2% of N-methylol acrylamide (N-MAM-P), and the functional monomers are itaconic acid (AA) rather than the application of acrylic acid (AA) alone. The use of IA) in a mixture of 50% and 1% was considered to be advantageous in forming a stable and good product without adhesion, cloudiness and gelation.

In addition, the main monomer that most affects the adhesion and water resistance is generally applied at about 35% in consideration of drying and workability, and styrene (SM) is more water-resistant than methyl methacrylate (MMA). As the amount of butyl acrylate (BA) and acrylonitrile (AN) was increased, cohesive force and adhesion were improved, resulting in less turbidity. However, too much butyl acrylate (BA) is the cause of poor gelation and stability during polymerization, the content is preferably limited to about 17 ~ 19%, and the increase of acrylonitrile (AN) also loses adhesion It was evaluated that it was preferable to cause it and to limit the content to about 7-8%.

In addition, if the glass transition temperature (Tg) is low, Tacky is excellent, and the initial adhesive strength is good, but the adhesive strength is low over time, and if the glass transition temperature (Tg) is too high, the cold resistance may not be good, so that the turbidity may occur. Considering the glass transition temperature (Tg) was evaluated to be preferably adjusted to about 4 ~ 5 ℃. It was evaluated that the particle size is preferably about 0.1 to 0.2 µm in consideration of the difference in adhesive strength depending on the dryness.

  In addition, by adding a fluorine-based water repellent as an additive to improve water resistance, weather resistance and surface contact angle, it was evaluated that the surface tension can be lowered to improve water repellency (prevention of moisture absorption) during outdoor installation. Although a water repellent additive improves water repellency, it causes the fall of adhesive force and heat resistance, and raises a product cost, it was evaluated that it is desirable to restrict the content to about 1.5%.

In addition, by increasing the aging time after the completion of the polymerization in order to improve the odor of the acrylic product caused by the acrylic monomer remaining due to the solid content yield and unreacted, the solid matter yield is increased and the odor problem is improved compared to the existing sample In addition, the effect of reducing the cloudiness and improving the adhesive strength was obtained.

The final evaluation result is shown in [Table 5] below.

(×: poor, △: medium, ○: good, ◎: very good)

As shown in Table 5, the test results for each of the top coat adhesive samples contained only a nonionic surfactant, mixed use of acrylic acid (AA) and itaconic acid (IA), and a glass transition temperature (Tg). ) Is 4 ~ 5 ℃, test sample # 10 prepared by extending the maturation time was found to have the best physical properties to the top coat adhesive liquid. Specifically, test sample # 10 was 59.2% of distilled water, 0.9% of nonion (NP free type) as a surfactant, 0.2% and 0.1% of APS (Ammonium persulfate) and SBS (Sodium metabisulfate) as an initiator, and styrene as a main monomer, respectively. (Styrene), BA (Butyl acrylate) and AN (Acrylonitrile) 9.2%, 17.7%, 8.0%, respectively, functional monomers N-MAM-P (N-Methylol acrylamide, 50%) 1.6%, functional monomers AA ( 0.4% of acrylic acid) and IA (Itaconic acid), 0.1% of antifoam, 0.6% of ammonium hydroxide (NH ₄ OH), and 1.5% of fluorine-based water repellent as an additive.

In addition, the accelerated weather resistance test, the moisture resistance test, and the water repellency test for each of the top coat adhesive samples showed that the top coat adhesive sample # 10 had better performance than the other samples.

The accelerated weather resistance test and the moisture resistance test were carried out in the same manner as the accelerated weather resistance test and the moisture resistance test of the undercoat adhesive sample described above. The good or bad water repellency is the difference between poor wetness and easy wetness. Water repellency can be assessed by the contact angle size of the droplets forming on the surface of the sample. The larger the contact angle of the water droplets, the easier the water droplets flow off the surface of the sample. Generally, when the contact angle of the water droplets exceeds 100 °, the water repellency is evaluated to be good. As a result of the water repellency test using the contact angle tester (KYOWA Dropmaster 500) applying the water droplet method specified in the KS L 2110, the contact sample of the conventional top coat adhesive was found to have a contact angle of 60 ° to 70 °. The test sample to which the adhesive liquid sample # 10 was applied was found to have a contact angle of 90 ° or more.

As described above, the present applicant has developed a method for reducing the manufacturing cost by improving the curing process during the manufacturing process of the metal tile with the development of the base coat liquid and the top coat liquid which can improve the quality of the metal tile. Improvements to the curing process, along with the development of adhesive solutions that react at low temperatures, are essentially lowering the curing temperature and reducing curing time while maintaining the adhesion of minerals above a certain level. Optimized curing temperature control over time is required to lower the curing temperature and reduce the curing time while maintaining the adhesion of minerals above a certain level.

For this purpose, a metal tile test sample was prepared using the newly developed undercoat adhesive solution (corresponding to the undercoat adhesive sample # 8) and the top coat adhesive solution (corresponding to the topcoat adhesive sample # 10) as described above. A galvanium steel sheet was used as the metal base plate of the metal tile and the test sample.

Specifically, calcium carbonate (10 kg), a thickener (1 kg) and a pigment (0.2 kg) were mixed with the undercoat adhesive sample # 8 (50 kg), and the metal base plate (340 mm × 457 mm) was prepared using the mixed adhesive solution. The mineral (coated stone colored with pigment on volcanic stone powder) was coated on it, and a top coat adhesive sample # 10 was applied thereon to prepare a metal tile test sample.

The metal groups and test samples thus prepared were cured according to the existing curing temperature control program as shown in FIG. 2, and then immersed in water at 80 ° C. for about 1 hour, and then confirmed whether the mineral coating layer was peeled off, resulting in partial swelling. 80 out of 100 cases occurred. This problem was analyzed to occur due to the rapid drying of the surface portion when the adhesive liquid dries.

In order to solve this problem, the applicant has improved the curing temperature control program as shown in FIG. 3. This curing temperature control program suppresses the sudden rise in temperature by increasing the rise time and reducing the stall period. According to this new curing temperature control program, the same metal groups and test samples were cured, and then immersed in water at 80 ° C. for about 1 hour, and then confirmed whether the mineral coating layer was peeled off.

As such, the present invention improves the curing temperature control program to cure minerals coated on the metal base plate for a shorter time at lower curing temperatures than in the prior art, thereby greatly reducing energy consumption in the curing process. .

Applicant manufactures sample metal roof tiles using newly developed undercoat adhesive (corresponding to undercoat adhesive sample # 8) and topcoat adhesive (corresponding to topcoat adhesive sample # 10) and a new curing temperature control program. Physical property tests (promoting weather resistance, moisture resistance, heat resistance, surface mineral loss amount, acid resistance and alkali resistance, cold and hot repeated tests) were conducted. Galvanium steel sheet was used as a metal base plate used in the manufacture of metal roof tiles, and as a mineral material coated on the metal base plate, volcanic stone powder was colored with pigments.

Among the physical property tests, the accelerated weather resistance test (Korean Industrial Standard KS F 4751), the moisture resistance test (Korean Industrial Standard KS F 4751), and the thermal performance test (Korean Industrial Standard KS F 4751) are performed in the same manner as the evaluation of the adhesive solution described above. It became. As a result of this test, the accelerated weather resistance (1,700 hours) was not abnormal, the moisture resistance (1,500 hours) was not abnormal, and the heat resistance (500 minutes) was not abnormal.

The surface mineral loss test is carried out by dropping the surface of the sample with a soft brush, etc., and then measuring the mass.The surface mineral loss tester is mounted on the surface mineral loss tester with the surface of the sample up, and 50 round trips / s with a 2,300 ± 5g test iron brush on the surface of the sample. After rubbing at a speed of min, remove the separated minerals from the surface of the test object and measure the mass to evaluate the difference from the mass measured before the test. These tests can be used to physically assess the adhesion between steel and minerals by the method specified in KS F 4751. As a result of testing on three samples, the amount of surface mineral loss of the sample metal tile was 0.27g, 0.25g and 0.24g, which was smaller than the conventional one.

Acid and alkali resistance test is a test for evaluating the chemical resistance of the metal coating mineral coating layer and the back steel sheet, the test method is as follows. First, a polyethylene ring having an open top and bottom on a metal tile is placed therein, and an acidic or alkaline liquid is filled therein at least 1/2, the top of which is opened with a glass plate is covered, and then left to stand at an evaluation time of 20 ± 2 ° C. 2% sulfuric acid solution was used as acid solution in acid resistance test and saturated lime water was used as alkaline solution in alkali resistance test. Thereafter, the polyethylene ring is removed, the metal group and the surface are washed with water and left in the room for 1 hour, and then the surface is visually inspected to check the discoloration and peeling of the mineral and the metal base plate. As a result of the test (KS F 4751), the sample metal tile was found to have no abnormality in acid resistance (120 hours) and alkali resistance (120 hours).

The cold and cold repetition test is a test to evaluate the degree of damage of the product by generating thermal fatigue caused by repeated heating and cooling.The test conditions of [Table 6] below are applied to one cycle using the test method of KS F 5602. The test was repeated to determine whether the minerals in the sample fell and changed color, cracks, and swelling before and after the test.

The cold and hot test (1,200 hours, 50 cycles) showed no abnormality.

On the other hand, the most closely related to the life of the product among the causes of the failure of the metal tile and the factor that can be easily applied to the life expectancy is the amount of surface mineral loss. Applicant has designed the life assessment method by focusing on the weight loss of the product due to wear and the correlation between the loss of minerals caused by various environmental factors and product life.

To this end, first of all, the actual construction metals and samples for each year can be collected, and the production lot unit weight was identified when the product was actually produced, and compared with the unit weight of the sample actually collected. The change trend was measured. After the accelerated deterioration of the existing metal tile and the improved metal tile and the sample under the same conditions as the accelerated weathering test described above at regular time intervals, a certain form of abrasion test was performed to change the weight loss similar to the weight loss trend of the actual product. In addition, the lifespan of the improved metal roof tiles was predicted through correlation analysis between the actual situation and the shortened life span by the accelerated deterioration test.

More than three field samples were collected from actual construction metal tiles and samples selected between 2002 and 2009. Although the initial unit weight of the collected sample cannot be accurately determined, the representative number of the production lot unit weight (g / m 2) at the time of production can be known from the serial numbers of the samples. The weight (g / m 2) was estimated. The actual weight of the collected samples was repeatedly measured to measure the average unit weight (g / ㎡) of the collected samples by year, and the average wear loss (g / ㎡) was obtained by subtracting the unit weight of the actual sample from the initial unit weight. . The average wear reduction values for each year of the actual field samples thus obtained are shown in Table 7 below.

Several repeated measurements showed that the yearly wear loss of the field samples is the same as the graph shown in FIG. 4. Looking at the graph of Figure 4 it can be seen that the wear loss is steadily increased as the number of installation years increases. On the basis of the change trend shown in the graph of FIG. 4, a graph as shown in FIG. 5 was derived by analyzing the subsequent change under the assumption that “the actual product continuously decreases its weight according to the number of years of installation without failure”. Through this, the wear loss by year can be expected as shown in [Table 8] below.

In order to evaluate the problems that may occur due to the construction of real metal roof tiles outdoors, an environmental resistance test that combines accelerated deterioration and abrasion tests was conducted. The reason is that the accelerated deterioration test of KS F 2274 alone can not realize the wear condition, so the wear test was added to simulate the test condition as closely as possible. Environmental resistance tests of metal roofs were carried out in the accelerated deterioration test of light irradiation and water spray by the open flame carbon-arc lamp presented in KS F 2274, and the surface mineral loss test presented in KS F 4751, KS L 1001. The presented wear tests were conducted in parallel, and then compared with the expected data estimated by the actual wear loss.

First, accelerated deterioration of existing and improved products was sampled every 100 hours, and then surface mineral loss experiments were conducted. As a result, as shown in the graph shown in Figure 6 there was a difference from the actual expected wear loss. The weight of the sole used during wear was so heavy that abrasion increased rapidly after more than 500 hours of accelerated deterioration. Since it is not easy to experiment by changing the weight of the wear brush in this experiment, the subsequent abrasion test was carried out by abrasion resistance test using the abrasive material specified in KS L 1001.

The abrasion test of KS L 1001 was carried out by dropping the silicon carbide abrasive (C, particle size 20) specified in KS L 6508 at a height of 1,100 mm using a wear tester as shown in FIG. By doing so, the amount of wear can be adjusted in accordance with the amount of the abrasive to be dropped. As a result of experiment by changing the amount of grinding material by 5kg, when the amount of grinding material was used 15kg, the change was the most similar to the actual wear loss data. As a result, the wear loss value as shown in [Table 9] can be obtained. there was.

And based on these data, the wear loss change graph according to the accelerated deterioration time as shown in FIG. Looking at the graph of Figure 8, it can be clearly seen that the improvement of the reliability of the improved metal group compared to the existing metal group. Although it is not apparent at the early stage of accelerated degradation, the difference is apparent after 500 hours of accelerated degradation. This means that the existing product rapidly deteriorates after 500 hours of accelerated deterioration. When a failure such as discoloration occurs around 700 hours before and after the actual deterioration, the correlation between actual wear loss data and wear loss data after accelerated deterioration and wear test It can be determined that the comparison is sufficiently reliable. In fact, as a result of analyzing the correlation between the years of installation and the accelerated deterioration time based on the wear loss, the result was linear as shown in FIG. 9, and the coefficient of determination was 0.99, which is close to 1.

On the basis of this analysis, the lifespan of the existing metal roof tiles and the improved metal roof tiles manufactured by the manufacturing method according to the present invention was estimated. In the case of the existing products, failures such as discoloration occurred after about 700 hours in the accelerated deterioration test. In the case of the product, it was evaluated that no failure occurred for more than 1,300 hours. It is estimated that existing products of 700 hours of accelerated degradation have a lifespan of less than 15 years, and 1,300 hours of improved degradation have a lifespan of about 25 years or more. In conclusion, this study found that life expectancy increased by more than 10 years.

As described above, the coating solution for mineral adhesion according to the present invention is 2-ethylhexyl acrylate (2-EHA) and methyl methacrylate (MMA), which are main monomers, and acrylic acid, which is a functional monomer that improves heat resistance and cohesion. AA), N-methylol acrylamide (N-MAM-P), which improves the degree of crosslinking, and a melamine-based resin as an additive, and have adhesive strength, stability, accelerated weather resistance, moisture resistance, heat resistance, etc. The overall required physical properties required for the adhesive coating are excellent.

In addition, the top coat liquid for adhesion of minerals according to the present invention contains a nonionic surfactant, acrylic acid (AA), itaconic acid (IA), and a fluorine-based water repellent, and has a higher turbidity, mineral loss, Excellent overall physical properties required for top coat adhesives such as accelerated weather resistance, moisture resistance and water repellency.

In addition, the method of manufacturing a mineral coated metal tile according to the present invention uses an improved undercoat adhesive and a topcoat adhesive, and cures the mineral coated on the metal base plate for a shorter time at a lower curing temperature than in the prior art. By doing so, the quality of the product can be improved compared to the conventional one, and the energy consumption in the curing process can be greatly reduced, thereby reducing the manufacturing cost.

The embodiments of the present invention described above and shown in the drawings should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and those skilled in the art can improve and modify the technical idea of the present invention in various forms. Accordingly, these modifications and variations are intended to fall within the scope of the present invention as long as it is obvious to those skilled in the art.

Claims (9)

(a) forming a metal base plate using the metal plate;
(b) forming a mineral coating layer on the surface of the metal base plate by applying an undercoat adhesive to the surface of the metal base plate and attaching a mineral to it;
(c) applying a top coat adhesive on the mineral coating layer; And
and (d) curing the mineral coating layer formed on the metal base plate by applying heat.
The bottom coating liquid is 2-ethylhexyl acrylate (2-EHA; 2-Ethyl hexyl acrylate) and methyl methacrylate (MMA) as a main monomer, a surfactant, and en-methylol as a functional monomer. It is an aqueous acrylic adhesive liquid containing acrylamide (N-MAM-P; N-Methylol acrylamide, 50%) and a phosphate group-containing monomer,
The top coat liquid is Styrene, Butyl acrylate (BA) and Acrylonitrile (AN) as the main monomer, and N-MAM-P as the functional monomer. It is an aqueous acrylic adhesive liquid containing N-Methylol acrylamide, 50%),
The undercoat adhesive further includes acrylic acid (AA) as a functional monomer and a melamine resin as an additive,
The upper adhesive liquid further includes acrylic acid (AA; Acrylic acid) and itaconic acid (IA) as functional monomers, and a fluorine-based water repellent as an additive.
In the curing process of step (d), the curing temperature is increased to 25 ° C. for 25 minutes at room temperature, and maintained at 50 ° C. for 5 minutes, and then increased to 25 ° C. from 50 ° C. to 70 ° C., at 70 ° C. Maintaining for 120 minutes, and then raised for 25 minutes from 70 ℃ to 140 ℃, and 10 minutes at 140 ℃ to cure the mineral coating layer, characterized in that the metal roof. delete The method of claim 1,
The content of the functional group monomer is 1 to 2%, and the content of the additive is 1.5% or less. delete The method of claim 1,
Content of the said functional group monomer is about 1%, and the content of the said additive is about 1.5%, The manufacturing method of the metal tile. The method of claim 1,
The surfactant of the undercoat adhesive is sodium lauryl sulfate (Sodium lauryl sulfate) and the method of producing a metal tile, characterized in that the mixture is made of a free type (NP free type). The method of claim 1,
The surfactant of the top coat adhesive is a method of producing a metal tile, characterized in that the NP free type (NP free type). delete delete

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