Method for manufacturing flexible polyurethane foam having coating layer formed thereon

Abstract

The present invention relates to a method for manufacturing flexible polyurethane foam having a coating layer formed thereon, the coating layer being formed on polyurethane foam (PUF). In addition, the coating layer is characterized by comprising yellow clay, a zeolite mineral, and a germanium raw material. Moreover, as the coating layer further comprises a urushiol extract, the present invention has remarkable effects including minimal alteration of the physical properties of the polyurethane foam, excellent antibacterial properties, enhanced far-infrared radiation, superior deodorization, odor reduction, and dehumidification capabilities, as well as heat-storage and heat-generation properties.

Description

Method for manufacturing soft polyurethane foam in which a coating layer is formed

[0001] The present invention relates to a method for manufacturing a natural antibacterial, deodorizing, dehumidifying, and far-infrared soft polyurethane foam, and more specifically, to a method for manufacturing a natural mineral solution for soft bio-polyurethane foam with added natural antibacterial, far-infrared, deodorizing, odor reduction, dehumidifying, heat storage, and heat generation properties, and a coating method for spraying and adsorbing the manufactured solution onto a finished soft polyurethane foam, and to a manufacturing method that imparts natural antibacterial, far-infrared, deodorizing, odor reduction, heat storage, and heat generation functions with a single application.

[0002] Polyurethane foam is a polymer compound containing urethane bonds within its molecular structure. It is a foamed product obtained by mixing and reacting polyols and isocyanates as main ingredients with blowing agents, catalysts, foam stabilizers, and functional additives, and is classified into rigid, semi-rigid, and flexible types.

[0003] Soft polyurethane is widely used as a raw material for automobiles due to its ability to realize various physical properties and its unique elasticity and lightness. In particular, it is widely used as a cushioning material for bedding because of its excellent elastic recovery and thermal insulation properties.

[0004] However, to reduce bacterial growth, moisture generation, and odor in soft polyurethane foam, various antibacterial agents and deodorizers have been introduced, and attempts have been made to develop bio-polyurethane foam products by powdering or nano-sizing ceramics to generate far-infrared energy that affects the human body.

[0005] To impart antibacterial properties to fully foamed polyurethane foam, commercially available organic antibacterial chemicals, such as organic mercury compounds, organic cotton compounds, organic nitrogen compounds, and organosilicon quaternary ammonium, are selected and added to the polyurethane raw materials. By foaming the polyurethane foam, antibacterial effects and bacterial growth are inhibited.

[0006] When polyurethane foam is manufactured in this manner and used for car seats or bedding, it has good sterilizing properties but is highly toxic; therefore, if inhaled through the respiratory system during prolonged use, it causes allergic reactions and toxicity to the blood, liver, and kidneys, which is fatal to the human body; thus, its application as an antimicrobial agent for polymer materials is prohibited.

[0007] When zeolites, silica alumina, silver, copper, zinc, titanium, silver-bearing materials, ceramic inorganic particles, and metal particles are mixed with or compounded with polyurethane foam raw materials, they have fine pores, a large surface area, and excellent heat resistance, but they have low antibacterial properties and cause changes in physical properties such as degradation of the polymer material or yellowing, and there are limitations in application depending on the characteristics of the material.

[0008] When manufacturing functional polyurethane foam by pulverizing far-infrared radiators such as charcoal, red clay, jade, green tea, maifan stone, and germanium and applying them to the surface of the polyurethane foam to impart far-infrared emissivity and radiant energy functions to the human body, the far-infrared emissivity and radiant energy are insufficient, and the practicality of product development is reduced due to the problem of color contamination on the foam cover when the product is used.

[0009] As mentioned above, methods such as deodorizers and organic antimicrobial agents have been introduced to improve the antibacterial properties and reduce odors of polyurethane foam, but the reality is that there are difficulties in using inorganic and metal particles because they are difficult to disperse and have minimal effects when introduced.

[0010] Recently, attempts have been made to develop products by foaming polyurethane foam using nano-sized ceramic powder and antimicrobial components extracted from plants as antimicrobial agents, but this is virtually impossible due to the phenomenon of nano-particle clumping.

[0011] As an example of prior art, registration number 10-0847882 describes a polyol having 2 to 5 functional groups, an ethylene oxide content of 0 to 30 weight%, and a propylene oxide content of 70 to 100

[0012] A flexible polyurethane foam composition is disclosed, characterized by containing nanoparticles of a polyol, a diisocyanate, and a precious metal, wherein the polyether polyol has a molecular weight in the range of 400 to 7,000 in weight% and 0.1 to 99.9 weight% contains a polymeric polyether polyol having a solid content of 20 to 60 weight% of a copolymerized vinyl compound. Additionally, Patent Publication No. Teuk 2003-0081245 discloses a raw material aging step in which raw materials comprising a polyol, an isocyanate, and tourmaline, which react to produce polyurethane, are mixed in a tank and aged;

[0013] A foaming step in which the raw material, which has been aged in each of the above tanks, is sprayed at high pressure using a pump to foam the polyurethane;

[0014] A curing step in which the polyurethane foam that has undergone the above foaming step is naturally dried in the shade for 24 hours to cure;

[0015] A method for manufacturing a polyurethane foam is disclosed, characterized by including a cutting step for cutting the polyurethane foam that has undergone the above aging step; and

[0016] Publication No. 10-2014-0079700 discloses an antimicrobial bio-polyurethane foam comprising a reaction product of a resin premix and an isocyanate, wherein the resin premix comprises 5 to 20 weight percent of a bio-polyol.

[0017] However, the aforementioned conventional technologies had the disadvantage that the physical properties of the polyurethane foam were prone to change and functions such as antibacterial and deodorizing properties were degraded.

[0018] Therefore, the present invention has been devised to solve the above-mentioned problems,

[0019] The present invention provides a method for manufacturing a natural mineral solution required for manufacturing a soft bio-polyurethane foam with added natural antibacterial, far-infrared, deodorizing, odor reduction, dehumidifying, heat storage, and heat generation properties, and a manufacturing method in which the manufactured solution is applied once as a spray coating to the finished soft polyurethane foam to impart natural antibacterial, far-infrared, deodorizing, odor reduction, heat storage, and heat generation functions without altering the physical properties of the polyurethane foam.

[0020] The present invention relates to a method for manufacturing a soft polyurethane foam in which a coating layer is formed, characterized in that a coating layer is formed on a polyurethane foam (PUF).

[0021] In addition, the coating layer is characterized by containing loess, zeolite minerals, and germanium raw materials.

[0022] In addition, the coating layer is characterized by further including a urushiol extract.

[0023] Therefore, the present invention has significant effects, such as minimal deformation of the physical properties of the polyurethane foam, good antibacterial power, effective far-infrared radiation emission, excellent deodorization, odor reduction, and dehumidification capabilities, as well as heat storage and heat generation properties.

[0024] FIG. 1 is a manufacturing process diagram of the present invention.

[0025] FIG. 2 is a manufacturing process diagram according to the use of raw materials of the present invention.

[0026] Figure 3 is a manufacturing process flowchart of the present invention

[0027] FIG. 4 is a test report of the present invention (far-infrared emissivity, radiant energy comparison report)

[0028] FIG. 5 is a test report (antibacterial test report) of the present invention

[0029] FIG. 6 is the test report of the Kevin filter of the present invention.

[0030] The raw materials of the soft polyurethane foam (PUF) of the present invention are isocyanate and resin premix.

[0031] To begin with, let me explain the definition of Polyurethane Foam (PUF).

[0032] PUF is a foaming agent produced by using petrochemical-based isocyanates and polyols as primary raw materials, blending them with foaming agents, catalysts, activators, and other additives, and then inducing a cross-linking network reaction to enlarge the molecules. Simultaneously, the resulting gas causes the molecules to expand, forming spherical, hemispherical, or polygonal cellular structures, which are then hardened.

[0033] Recently, to achieve uniformity in foam products, differences in open or closed phases of bubbles, and reproducibility of chemical and physical properties, various factors such as changes and rates in the reaction process involving polyols, isocyanates, water or blowing agents, catalysts, and additives, as well as the amount and rate of gas generation and curing time, are intricately intertwined and influence the results; consequently, there is a wide variety of polyurethane foam types. They are primarily classified by differences in density and hardness. Furthermore, to continuously obtain foam with consistent properties, precise raw materials, reliable and reproducible operating methods, and process leveling are required. The size of the cells (bubbles forming the foam) is determined by the stirring speed, ejection pressure, air injection amount, and the method used.

[0034] Polyester foam and polyether foam can be classified depending on the type of polyol used as the main raw material. The criterion for distinguishing between polyether type and polyester type is whether the connection between polyol molecules is a continuous ether bond (-O-) or an ester bond (-COO-).

[0035] The characteristics of a PUF

[0036] Advantages: - Adjustable hardness and good elasticity. - Excellent wear resistance. - High mechanical strength. - Good ozone resistance. - Excellent low-temperature characteristics. - Excellent vibration absorption. - Free molding (mold method). - Excellent adhesion to metal (spray method). Disadvantages: - Poor heat aging resistance. - Tendency to retain heat.

[0037] PUF is classified as follows according to hardness and density.

[0038] Flexible PUF offers good cushioning properties and mechanical strength (elongation, tensile strength, and abrasion resistance). Its open-cell structure ensures good breathability, and a wide range of specific gravities and various physical properties can be controlled through formulation. Applications of flexible PUF are broadly categorized into transportation, furniture, and packaging materials. The respective proportions are approximately 42% for transportation, 47% for furniture, and 11% for packaging and other uses. In the transportation sector, products utilizing MDI-based isocyanates are primarily used. Flexible PUF accounts for about 60% of all polyurethane foams and represents a demand equivalent to 30% of total polyurethane products. Rigid PUF utilizes its inherent properties, such as thermal insulation, lightweightness, and cushioning, to be widely used as insulation, lightweight structural materials, and cushioning materials, either alone or in combination with other materials. Rigid polyurethane foam has the lowest thermal conductivity among practical insulation materials, and its applications as an insulation material account for 80–90% of the total. Rigid polyurethane foam is the only insulation material that can be used in a wide temperature range, from the high-temperature range of 150°C to the cryogenic range of fuel tanks for satellite launch rockets (-235°C). Semi-rigid PUF has characteristics that are intermediate between those of soft and rigid PUF.

[0039] And the classification according to polyol type is as follows.

[0040] ESTER Type ETHER Type Superior mechanical properties compared to ETHER Type Superior wear resistance Superior cold resistance Superior oil resistance Superior elasticity Superior mechanical properties Superior chemical resistance Superior water resistance Superior cold resistance Superior rebound force compared to ESTER Type Superior dynamic fatigue characteristics

[0041] Furthermore, the classification according to manufacturing and methods is as follows. Flexible polyurethane foam is classified into slab foam and mold foam according to the production method, and mold foam is divided into hot cure foam and cold cure foam according to the curing method.

[0042] Slab Foam refers to foam that is used by free-foaming and curing the liquid without injecting it into a mold, and then cutting (skiving) the cured foam into the desired shape; the raw materials used are low molecular weight polyols and TDI. It is a foam that forms a product according to the mold shape by injecting the liquid into a mold of a specific shape. Hot-Cure Foam requires a high curing temperature (120–150°C) for curing, and the raw materials used are low molecular weight polyols and TDI. Cold-Cure Foam cures at a low temperature (curing temperature: 50–65°C), and high molecular weight polyols and TDI or MDI are used.

[0043] The raw material for flexible PUF is 1) isocyanate

[0044] MDI, TDI, and MDI / TDI blend products are used, and in Korea, M / T blend products that complement the advantages and disadvantages of MDI and TDI are generally used.

[0045] 2) Resin premix

[0046] A high molecular weight polyol with low crosslinking strength is used, which is a mixture of polyol, crosslinking agent, catalyst, foaming agent (water), foam stabilizer, and other additives.

[0047] Polyols: Polyether and polyester polyols are used, either alone or in combination, depending on the initiator and the number of functional groups.

[0048] Foam stabilizers: Silicone foam stabilizers are used for resin emulsification, dispersion of foaming gases, prevention of cell rupture, stabilization of cell membranes, and improvement of thermal insulation performance.

[0049] Catalyst: Used to control reaction rate and improve moldability, and 2 to 3 types of catalysts are used in combination.

[0050] Foaming agents: Water, R-11, HCFC-141b, Cyclopentane, etc. are used, and alternative foaming agents such as HFC-245fa are used.

[0051]

[0052] The applications of the flexible PUF of the present invention in the automotive field are as follows.

[0053] The leading fields for soft polyurethane foam technology are applications used for automotive interiors, which require excellent moldability, quality, and physical properties. Most soft polyurethane foam used for automotive interiors is mold foam and is applied in about 10 different areas.

[0054] -SEAT CUSHION & BACK

[0055] -HEAD / ARM REST

[0056] -DOOR TRIM

[0057] - EERGY ABSORBING FOAM

[0058] - SOUND ABSORBING FOAM

[0059] - VIBRATING DAMPING FOAM

[0060] -SUNVISOR

[0061] -INSTRUMENT PANEL

[0062] -STEERING WHEEL

[0063] -FLOOR MAT (Floor Mat)

[0064] -WINDOW ENCAPSULATION

[0065] -CARPET BACKING

[0066] -HEAD LINER

[0067]

[0068] The manufacturing method is roughly as follows.

[0069] This is a process of mixing isocyanate and resin premix (polyol, catalyst, foaming agent, foam stabilizer, and other additives). At this time, a mixing temperature of 28°C ±2°C is suitable.

[0070] A blowing agent is a substance used to manufacture foam that forms bubbles during a polymer reaction; there are continuous foaming and slab foaming processes. This process is the slab foaming process. At this time, the sponge temperature is 150°C to 160°C.

[0071] Following the foaming process, an aging process of approximately 24 hours (36 hours in winter due to low temperatures) is performed to prevent deformation. If the material is cut before undergoing this aging process...

[0072] The problem of deformation occurs. This experiment is an experiment in which a part was removed and pressure was applied immediately after the foaming process.

[0073] After undergoing 24 hours of curing, physical property testing is performed before skiving to meet customer requirements; this testing is conducted first when initial prototypes or new products are developed. Physical property testing tools include UTMs, scales, and flammability testers.

[0074] To connect the two sides of the massive foam in an elliptical shape, the two sides are glued together and then the foam is rotated. The height of the horizontal blade is adjusted to control the T-dimension (height) according to the customer's requirements.

[0075] Check the product Lot No. and perform a final inspection.

[0076] The specific manufacturing process for flexible PUF is as follows.

[0077]

[0078] Polyurethane foam is a polymer compound containing urethane bonds within its molecular structure, and is a product obtained by mixing and reacting foaming agents, catalysts, and foam stabilizers with polyols and isocyanates as the main components. Polyurethane foam uses polyols and isocyanates as the main raw materials, each independent

[0079] Instantly mixed by a high-speed stirring rod at the mixing head through the line

[0080] It is produced through a foaming reaction.

[0081]

[0082] The present invention relates to a process for forming a coating layer on a soft polyurethane foam, comprising: a coating solution preparation step of preparing a natural mineral coating solution; and a coating step of spray-coating the prepared solution onto the finished soft polyurethane foam. The coating method mainly adopts a conventional spray coating method, and the coating thickness is formed to be 0.1 to 1.6 mm. The temperature can be between 5 and 80 degrees. The spray coating is applied once.

[0083] The method for preparing a natural mineral coating solution used in the present invention is as follows.

[0084]

[0085] 1. First stage of basic raw material preparation process

[0086] The functional raw materials were obtained and utilized by heating loess, zeolite minerals, and germanium raw materials to a range of 800–1000°C to perform a sterilization process, crushing them, and separating them into desired particle sizes through sieving. The loess was prepared as a powder that passed through a 2000–5000 mesh sieve, the zeolite mineral as a powder that passed through a 1000–1500 mesh sieve, the germanium as a powder that passed through a 500–1000 mesh sieve, and the tourmaline as a powder that passed through a 1500–3000 mesh sieve. Additionally, the calcined shell powder obtained by calcining shellfish in a high-temperature kiln at a range of 1000±200°C for more than 10 hours and then crushing it was prepared as a powder that passed through a 1000–3500 mesh sieve.

[0087]

[0088] 2. Second stage process of stirring and homogenization

[0089] The above-mentioned natural mineral material powders are mixed with 0.5 kg of the mineral loess powder, 0.3 kg of the zeolite powder, 1 kg of the germanium powder, 0.9 kg of the tourmaline powder, and 0.3 kg of the seashell powder in 7 kg of water to obtain a homogenized solution for use. More specifically, each of the above-mentioned raw material powders is weighed and introduced into a mixing tank, followed by a process of stirring and mixing. At this time, homogenization can be achieved by mixing with a high-speed stirrer rotating at 1200 ± 200 rpm for 3 to 5 days at an internal temperature of 50°C to 85°C in the mixing tank. However, if the internal temperature of the mixing tank is below 50°C, there is a problem in that the extraction efficiency of the main components constituting the natural mineral material powder decreases, and if it is above 85°C, there is a problem in that the far-infrared radiation function of the main components constituting the natural mineral powder decreases; therefore, it is desirable to maintain the internal temperature of the mixing tank within the range of 50°C to 85°C.

[0090]

[0091] 3. Third stage of the supernatant collection process

[0092] After stopping the high-speed stirrer of the mixing tank in the second stage of the above process, the crushed natural mineral powder is allowed to settle naturally for 1.5 to 2.0 hours to settle to the bottom, and then the sedimentation liquid is separated into a funnel-shaped separation container, leaving only the supernatant liquid, so that only the supernatant liquid can be obtained.

[0093]

[0094] 4. Fourth step process for obtaining urushiol extract

[0095] Urushiol, the main component of lacquer tree sap, has a chemical structure in which a chain of 15 carbon atoms is substituted at the 3rd position of a benzene ring on a catechol, and the degree of unsaturation in the carbon chain corresponding to the tail varies. In this study, urushiol was extracted from lacquer tree sap collected from a lacquer tree and applied. Acetone and lacquer tree sap were mixed in a volume ratio of 3:1 and left at room temperature for 8 hours. The supernatant separated into layers was mixed with acetone again, and the supernatant was separated three times using the same method as above. The separated supernatant was then subjected to vacuum distillation to remove acetone, thereby obtaining and using the urushiol extract.

[0096]

[0097] 5. Step 5 process for obtaining castor antibacterial component extract

[0098] Castor beans are known to have strong antibacterial properties due to the presence of fatty acids such as ricylenol, oleic acid, and steroids. In fact, animal studies have reported that castor beans are effective in preventing and treating viral infections, including those caused by bacteria, viruses, fungi, herpes viruses, influenza viruses, and HIV.

[0099] .

[0100] To obtain an acetone extract of castor leaf powder, 2 kg of castor oil was dried at 8–15°C for 3 days. Then, 1 kg of powder made from dried castor leaves ground to 200 mesh was mixed with 3 times the amount of acetone as the powder, and the extraction was repeated twice by stirring at 325 rpm at room temperature for 24 hours. The extracts obtained from the two extractions were combined, filtered once, concentrated under reduced pressure using a rotary evaporator at 45°C, filtered a second time, left at room temperature for 24 hours, and then the supernatant was separated.

[0101]

[0102] 6. Step 5 process for obtaining the coating function solution

[0103] The supernatant obtained from the third step process, the urushiol extract obtained from the fourth step process, and the supernatant obtained from the fifth step process are mixed in a mixing tank equipped with a high-speed stirrer and maintained at an internal temperature range of 50°C to 85°C, wherein the supernatant is simultaneously introduced into the mixing tank at a ratio of 5 parts by weight of urushiol extract to 95 parts by weight of supernatant, maintained at 50°C to 85°C, and mixed and stirred for 3 to 5 days at a stirring speed in the range of 1400±200 rpm, after which a coating solution having far-infrared radiation emission, antibacterial function, deodorizing function, and dehumidifying function is obtained.

[0104]

[0105] As a means to manufacture automotive cabin air filters, polyester raw materials PTA (high-purity terephthalic acid) and EG (ethylene glycol) become a gel-type polymer through a polymerization process in which heat and pressure are applied. After undergoing a process called spinning to draw out threads and a process called stretching to impart various physical properties, the material is cut into short pieces to form cotton and then moved to the next process.

[0106]

[0107] (How to apply)

[0108] 1. In the process of unraveling the cut cotton (directly by hand), the natural antibacterial, deodorizing, dehumidifying, and far-infrared radiation coating solution of the present invention is adsorbed onto the cotton using a humidifier device by a spraying method.

[0109]

[0110] 2. The loosened cotton forms a laminated structure in the form of fibers (fabric) by passing through a carder and a molding machine. After applying the solution of the present invention, which has natural antibacterial, deodorizing, dehumidifying, and far-infrared radiation functions, to the laminated fibers (fabric) using a humidifier spray method (to ensure proper adsorption when applied during the process of loosening the cut cotton, the solution is adsorbed onto the laminated fibers (fabric)), the laminated fabric can be manufactured by passing it through a heat calender that combines the laminated fabrics.

[0111] By applying it as described in 1.2 above, it is possible to manufacture an antibacterial automotive cabin air filter that is harmless to the human body and does not block the airflow of the cabin air filter, thus not affecting the automotive air conditioning system.

[0112]

[0113] Activated carbon filters are said to remove odors by adding an activated carbon layer to conventional filters, filtering the air one last time during air passage. However, a disadvantage of activated carbon filters is that if the replacement period is exceeded, harmful substances adsorbed by the activated carbon enter the indoor environment along with the filter, leading to further indoor air pollution.

[0114] With the release of cabin filters with antibacterial functions, the term "antibacterial filter" has become a proper noun, but problems have been discovered regarding the artificial increase in antibacterial power by applying chemicals to the filter paper surface of some products.

[0115] Conventional automotive air conditioner filters are designed to purify the air inside a vehicle. They consist of a non-woven filter paper, activated carbon placed inside the filter paper, and a binder installed along the perimeter. This configuration allows the filter to remove particles, such as dust, contained in the air entering the vehicle through the filter paper, and to deodorize odors by utilizing the adsorption capacity of the activated carbon. However, automotive air conditioner filters suffer from the problem of not effectively performing deodorization functions because the residual life of the activated carbon used as a deodorizer is relatively short. Furthermore, while some automotive air conditioner filters are designed to enhance antibacterial and sterilization functions by coating the non-woven fabric with an antibacterial agent, there have been many products where the antibacterial agent enters the vehicle interior in nanometer-sized particles, posing a threat to the driver's health. Therefore, there is an urgent need for an automotive air conditioner filter that filters the air entering the vehicle while utilizing natural antibacterial agents.

[0116]

[0117] Automotive air conditioner filters play the role of purifying harmful elements entering from the outside. The use of combination filters, which filter out both fine dust and harmful gases, is also increasing. Higher performance is required as environmental pollution and automotive market regulations become stricter. Typically, filters are manufactured by fixing highly adsorbent activated carbon onto non-woven fabric whose surface has been melted by applying heat.

[0118]

[0119] However, this method makes it difficult to meet the demands of the automotive industry. Applying heat to the front surface and adding a large amount of activated carbon reduces ventilation performance because the pores of the non-woven fabric become clogged. On the other hand, reducing the activated carbon content makes it difficult to properly filter out harmful substances. The chemical binding process that aids in the adhesion and fixation of the activated carbon is also a problem. Using chemicals such as ethylene vinyl acetate actually leads to the inclusion of harmful substances. Chemicals also have an adverse effect on purification performance.

[0120]

[0121] The cabin air filter fabric to which the present invention is applied does not use chemical antibacterial agents, so it is harmless to the human body, and since it is not a coating method using adhesives as in the conventional manufacturing of automotive cabin air filters, it does not block the airflow of the filter fabric and does not have an adverse effect on the automotive air conditioning system.

[0122] The present invention has the efficacy of antibacterial, deodorizing, dehumidifying, and far-infrared radiation functions with a single application of a functional composition, and can also be expected to extend the lifespan of the filter. It can also be applied to household air purifier filters.

[0123]

[0124] In other words, the present invention relates to a method for manufacturing a filter fabric for an automobile cabin air filter, wherein polyester raw materials PTA (high-purity terephthalic acid) and EG (ethylene glycol) become a gel-type polymer through a polymerization process in which heat and pressure are applied, and subsequently undergo a process called spinning to draw out threads and a process called stretching to impart physical properties, followed by a process of cutting into short pieces to form a cotton-like shape, and then moving to the next process.

[0125] The above method for manufacturing filter fabric is

[0126] Raw material preparation step 1, which involves heating loess, zeolite minerals, and germanium raw materials to perform a sterilization process, crushing them, and separating them into desired particle sizes through sieving to obtain and utilize the raw materials;

[0127] Second stage of stirring and homogenization;

[0128] Step 3 of supernatant collection;

[0129] Step 4 for obtaining urushiol extract;

[0130] Step 5 for obtaining the castor antibacterial component extract;

[0131] The method comprises a sixth step of obtaining a coating solution by mixing the supernatant obtained from the third step process, the urushiol extract obtained from the fourth step process, and the castor antibacterial component extract obtained from the fifth step process.

[0132] The above urushiol is obtained by extracting urushiol from lacquer tree sap. The process involves mixing acetone and lacquer sap in a volume ratio of 3:1, leaving the mixture at room temperature for 8 hours, then mixing the separated supernatant with acetone again, separating the supernatant three times in the same manner as above, and removing the acetone by vacuum distillation of the separated supernatant to obtain and use the urushiol extract.

[0133] The chemical structure of urushiol, the main component of the above lacquer sap, is a substance having a structure in which a chain consisting of 15 carbon atoms is substituted at the 3rd position of a benzene ring on catechol, and the degree of unsaturation in the carbon chain corresponding to the tail varies.

[0134] The mixing ratio of water, loess, zeolite mineral, and germanium raw material is 20 to 30 parts by weight of loess, 5 to 10 parts by weight of zeolite mineral, and 5 to 10 parts by weight of germanium raw material, relative to 100 parts by weight of water.

[0135] The mixing ratio of the supernatant obtained in the third stage process, the urushiol extract obtained in the fourth stage process, and the castor antibacterial component extract obtained in the fifth stage process is 5 to 10 parts by weight of urushiol extract and 20 to 30 parts by weight of castor antibacterial component extract relative to 100 parts by weight of supernatant.

[0136] The fifth step of obtaining the above-mentioned castor antibacterial component extract is characterized by a process of drying 2 kg of castor oil at 8–15°C for 3 days to obtain an acetone extract of castor leaf powder, adding 3 times the amount of acetone to 1 kg of powder obtained by grinding the dried castor leaves to 200 mesh, and repeating the stirring extraction at 325 rpm at room temperature for 24 hours twice, combining the extracts obtained from the two times, concentrating under reduced pressure using a rotary evaporator at 45°C after first filtration, performing a second filtration, leaving it at room temperature for 24 hours, and then separating the supernatant.

[0137] Toxins such as ricin are removed from castor leaves through a pretreatment process. Specifically, toxic or allergenic components, such as ricin, are neutralized through fermentation. The fermentation period is approximately 15 to 20 days at room temperature (20 to 25 degrees Celsius), and the leaves are stored in a container. The weight ratio of water to castor leaves is 1:1. Beneficial bacteria, such as lactic acid bacteria, are added to aid in fermentation.

[0138] The above urushiol extract and castor antibacterial component extract are prepared into a masterbatch, and then the masterbatch is used when preparing a coating solution.

[0139] Urushiol extract and castor antibacterial component extract are mixed in a weight ratio of 1:1.5 to 2.

[0140] The masterbatch is stirred in a stirrer at 60 to 70 degrees for 1 hour, and then fermented to remove toxins. The fermentation period is approximately 15 to 20 days at room temperature (20 to 25 degrees), and the mixture is stored in a container. The weight ratio of water to masterbatch is 1:1. Beneficial bacteria, such as lactic acid bacteria, are added to aid fermentation.

[0141] Meanwhile, fermentation is carried out in three stages: the first stage is at 20 to 25 degrees for about 3 to 5 days, the second stage is at 30 to 50 degrees for about 7 to 10 days, and the third stage is at 20 to 25 degrees for about 5 to 10 days. In particular, in the second stage, a solution in which castor leaves are boiled at 100 degrees is added to the total fermentation liquid at a rate of about 3 to 5 weight percent. When boiled, the toxicity of the castor is eliminated and becomes a nutrient for beneficial bacteria to ferment.

[0142] The mixing ratio of the supernatant obtained in the third stage process and the masterbatch is 30 to 40 parts by weight of the masterbatch mixed with 100 parts by weight of the supernatant.

[0143] In cases where the fabric coating layer becomes rancid and discolors, the mixing ratio of the supernatant and the masterbatch is 40 to 50 parts by weight of the masterbatch per 100 parts by weight of the supernatant.

[0144] If the coating layer has weak adhesion and peeling is severe, a PTA solution is added, and 40 to 50 parts by weight of masterbatch and 3 to 5 parts by weight of PTA solution are mixed with respect to 100 parts by weight of supernatant.

Claims

1. A method for manufacturing a polyurethane foam having a coating layer formed thereon, characterized by forming a coating layer on a polyurethane foam (PUF).

2. A method for manufacturing polyurethane foam in which a coating layer is formed, wherein, in claim 1, the coating layer comprises loess, zeolite mineral, and germanium raw material.

3. A method for manufacturing a polyurethane foam having a coating layer formed, wherein, in paragraph 2, the coating layer further comprises a urushiol extract.

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