A production method of odorless antibacterial flexible polyurethane foam having cooling effect and formulation thereof

Abstract

The invention is related to a production method of slabstock flexible polyurethane foam and formulation thereof, which are developed for using in the sectors of textile, medical, bed, shoes... etc. where antibacterial, cooling provider and odor remover, moisture absorber properties are together.

Description

[0001] A PRODUCTION METHOD OF ODORLESS ANTIBACTERIAL FLEXIBLE POLYURETHANE FOAM HAVING COOLING EFFECT AND FORMULATION THEREOF

[0002] Technical Field

[0003] The invention is related to a production method of slabstock flexible polyurethane foam and formulation thereof, which are developed for using in the sectors of textile, medical, bed, shoes... etc. where antibacterial, cooling provider and odor remover, moisture absorber properties are provided to be together.

[0004] Prior Art

[0005] In the prior art, there are production techniques of flexible or rigid polyurethane foam (slabstock or mold) having a wide variety of recipes and production processes comprising various steps. Despite all of them have advantages and disadvantages on their own merits, polyurethane foams having new types of recipes and production processes need to be developed to solve ongoing problems.

[0006] In the patent titled ‘Polyurethane Foam Insole’ and numbered CN113150533A at the state of the art, polyurethane foam insole has been obtained inside mold by using 10-15 parts of rubber powder, 10-15 parts of polyurethane powder, 1.5-2 parts of carboxymethyl starch, 6- 8 parts of antibacterial powder, 8-12 parts of active carbon powder. In said document, amounts of filler such as rubber powder and polyurethane powder are quite high. When there is high amount of filler, weakening in polyurethane bonds occurs and this affects mechanical properties of polyurethane foam negatively.

[0007] In the patent titled ‘Insole Including Activated Carbon Nonwoven / Form’ and numbered KR20120001338U at another state of the art, insole has been obtained inside mold by getting layers of elastic ethylene vinyl acetate (EVA) and polyurethane foam including active carbon together to remove moisture, odor, antibacterial problems.

[0008] In the patent titled ‘Manufacturing Method of Shoes Insole Which Having Natural Substance’ and numbered KR20130105998A at another state of the art, EVA foam insole has been synthesized in mold by adding 5-15 parts of active carbon powder. In said document, mold production method has been preferred. However, it has been stated that since active carbon does not show homogeneous distribution, various problems occur in forming of polyurethane foam cells. That’s why, active carbon has been used inside EVA foam instead of polyurethane foam in the document.

[0009] In the patent titled ‘Polyurethane Foam Having Deodorization Property or Antibacterial Effect’ and numbered US7432312B2 at another state of the art, polyurethane foam has been produced in mold and by using carbon powder, titanium dioxide and silver as antibacterial agent.

[0010] In the patent titled ‘A Composite Material Formed by Using Boron During Production of A Polyurethane Base Material’ and numbered EP4127043A1 at another state of the art, polyurethane composite foam, in which at least 40 parts of boron compounds (borax pentahydrate, borax decahydrate, boric acid, anhydrous borax, zinc borate, boric acid etc.) have been added, has been synthesized and healing and therapeutic effects of boron compounds on skin have been studied. In the patent titled ‘Boron-Modified Flexible Polyurethane Foam for Hygiene and A Method of Production Therefor’ and numbered WO2021029836A1 at another state of the art, a hygienic flexible polyurethane foam having antibacterial, antimicrobial and antifungal properties has been produced with slabstock method and it has been used in foams of beds, pillows, insoles, floorings, bras.

[0011] Despite high amounts of fillers used in mold production techniques at the state of the art form negative effect in mechanical properties of foam, high amounts of said fillers does not pose a problem during polyurethane foam formation. Because the product produced inside mold is formed by rising on its own. However, because conveyor moves during foam formation in the production of slabstock flexible polyurethane foam, usage of filler in high ratios may cause flexible polyurethane foam on the conveyor to collapse before complete formation. Therefore, the amount of filler used in productions of slabstock flexible polyurethane foam needs to be optimized very well.

[0012] In any of studies at the state of the art, boron compound as an antibacterial agent for antibacterial properties, microcrystalline cellulose as a moisture absorber and active carbon composition as an odor remover have never been used together in production of flexible polyurethane foam and a flexible polyurethane foam formed by getting together three of them in a tunnel has not been produced. Summary of the Invention

[0013] The aim of the invention is to realize a formulation and production method for flexible polyurethane foam where air permeable, moisture, sweat and odor absorber, cooling and antibacterial properties are together by using active carbon, boron compound and microcrystalline cellulose together.

[0014] Because the amounts of fillers used in invention (microcrystalline cellulose, active carbon, boron compound) are such that they will not form a negative effect on polyurethane bonds, the mechanical properties of polyurethane foam (rigidity, breaking strength, elasticity, deformation etc.) are not affected.

[0015] In this invention, differently from the prior art, odor remover and moisture absorber properties have been gained to the flexible polyurethane foam except of antibacterial property by adding also active carbon and microcrystalline cellulose to the system in addition to boron compound.

[0016] The flexible polyurethane foam produced with the method and formulation of the invention can be used in the products where it contacts with human body and therefore, a more hygienic product is obtained by preventing negative effects such as odor, moisture, sweat. Said foam material is a healthy material contacting with human body.

[0017] In the previous studies, these three substances were used separately, but three substances were not used together. Each of said three substances adds a different property to the material.

[0018] In the invention, polyurethane foam reaction is performed in a tunnel not in a mold and for this reason, no heat is needed for the reaction. Active carbon, boron compound and microcrystalline cellulose used in said reaction have been dispersed in polyol and then isocyanate has been added to the system, by mixing with high speed mixer, flexible polyurethane foam has been obtained.

[0019] In the invention, tunnel method has been preferred for production with higher capacity and more homogeneous distribution. The percentage of each substance used in the invention has been preferred such that it can provide odor remover property, cooling property and antibacterial property in the most effective manner.

[0020] In the invention, the flexible polyurethane foam is produced in a tunnel and with a homogeneous distribution, various problems occurring in formation of polyurethane foam cells because of showing nonhomogeneous distribution in some production methods at the prior art have been solved with the invention.

[0021] Despite flexible polyurethane foam is produced by using molding method at the prior art, tunnel method has been used differently from other methods in the invention. Although slabstock method is a known method, this method causes some difficulties for polyurethane foam produced by getting all of three materials together. To be able to overcome these difficulties, if and only if usage percentages of all of three substances are the preferred percentages in the method of invention and the order indicated in the method realizes, the problems have been removed, the production of desired flexible polyurethane foam has been performed.

[0022] The invention has been developed for use in sectors such as textile, medical, bedding, shoes etc.

[0023] Detailed Description of the Invention

[0024] In the invention, slabstock flexible polyurethane foam comprising active carbon, microcrystalline cellulose and boron compound powders has been synthesized homogeneously in a tunnel and therefore, production has been performed in harmony with polyurethane foam cells. The slabstock method is a production method performed in a tunnel. The production is not made in a mold by using heat, it is made in a tunnel by leaving it on its own. That’s why, no heat is needed for the reaction. For antibacterial properties, boron compound as antibacterial agent, microcrystalline cellulose as moisture absorber have been used, and active carbon as odor remover, has been used together with them. Therefore, antibacterial, cooling and odor remover properties have been gained to the flexible polyurethane foam at the same time. In addition, the property of flexible polyurethane foam produced with the formulation and process (method) of invention has been gained due to boron compounds used. Active carbon provides odor adsorption due to its porous structure and high surface area. Boron compound is used due to its antibacterial property. Another reason for using boron compound is that it is commonly present in Turkiye. Microcrystalline cellulose is used due to its moisture absorber property. By using three of them together, a hygienic product which is not harmful to health is obtained. Because flexible polyurethane foam is used in a lot of fields, it is very important to be a hygienic product in terms of human health.

[0025] Due to high porous structure and surface area of active carbon used in the synthesis of flexible polyurethane foam of the invention, adsorption of the odor which will form when it contact with human body (shoes, bra, bed etc.) is provided. Boron compound provides a hygienic environment for foot with its antibacterial and antifungal properties. Besides, a dry environment is provided for foot with sweat and moisture absorption properties of microcrystalline cellulose. Microcrystalline cellulose makes the material gain cooling property due to its moisture absorption property. To sum up, boron compound for providing antibacterial property, microcrystalline cellulose for sweat adsorption, active carbon for odor adsorption have been used in the content of flexible polyurethane foam.

[0026] In the invention, it is not easy as in mold production to obtain slabstock flexible polyurethane foam whose reaction is completed by raising while moving on a conveyor by using the percentage of filler (carboxymethyl starch) whose formulation is given at the state of the art (at the prior art, 1.5-2 parts are used.).

[0027] For providing all of antibacterial, cooling, moisture absorber and odor remover effects; the slabstock flexible polyurethane foam formulation of the invention comprises polyether polyol comprising 20-30 parts of styrene acrylo nitrile by weight (its functionality is 3, its molecular weight is 2000 g / mol, its number of OH is 30 mg KOH / g), 10-20 parts of poly ether polyol by weight (its functionality is 3, its molecular weight is 5000 g / mol, its number of OH is 33 mg KOH / g), 60-70 parts of visco polyether polyol by weight (its functionality is 3, its molecular weight is 700 g / mol, its number of OH is 250 mg KOH / g) and the composition of active carbon, microcrystalline cellulose and boron compound, 0.5-2 parts of water by weight, 0.8-2 parts of silicon by weight, 0.1 -0.7 parts of amine catalyst by weight, 0.01-0.1 parts of tin catalyst by weight and 40-60 parts of diisocyanate by weight. Only when the percentages for all of three substances given in the invention are preferred, these three substances can be brought together in a tunnel. With these percentages, the desired reaction can be performed only in the tunnel.

[0028] Said visco polyether polyol (its functionality is 3, its molecular weight is 700 g / mol, its number of OH is 250 mg KOH / g) and the composition of active carbon, microcrystalline cellulose and boron compound comprise 75-91% visco polyether polyol by weight, 1-6% active carbon by weight, 1-6% microcrystalline cellulose by weight and 7-13% boron compound by weight.

[0029] In the preferred embodiment of the invention, visco polyether polyol and the composition of active carbon, microcrystalline cellulose and boron compound comprise 84-88% visco polyether polyol by weight, 2-3% active carbon by weight, 2-3% microcrystalline cellulose by weight and 8-10% boron compound by weight.

[0030] Isocyanates used in the formulation are polycarbodiimide modified 4,4-diphenylmethane diisocyanate and / or carbodiimide-uretonimine modified 4,4-diphenylmethane diisocyanate and / or 4,4-diphenylmethane diisocyanate (pure MDI) and / or 2,4 and 4,4-diphenylmethane diisocyanate (MDI) with 80 / 20 ratio and / or polymeric MDI and / or 2,4 and 2,6 toluene diisocyanate with 80 / 20 ratio (TDI 80) and / or 2,4 and 2,6 toluene diisocyanate with 65 / 35 ratio (TDI 65).

[0031] The substances and their functions used in the formulation have been given in the Table-1.

[0032] Table-1: Slabstock flexible polyurethane foam formulation

[0033] The formulation of the invention is prepared according to 100 parts of polyol. The slabstock flexible polyurethane foam production method comprises the steps below with the order indicated:

[0034] In the first step, mixing visco polyether polyol and the composition of active carbon, microcristalline cellulose and boron compound in predetermined percentages,

[0035] In the second step, pumping visco polyether polyol and the composition of active carbon, microcristalline cellulose and boron compound used, polyether polyol comprising styrene acrylo nitrile, cell opener polyether polyol, amine catalysts, silicon, water, tin catalyst and diisocyanate in predetermined percentages to the mixer respectively,

[0036] In the third step, mixing the mixture obtained with a high speed for a predetermined period, for example 1-2 seconds,

[0037] In the fourth step, transferring the mixed mixture to the chamber (or trough) and raising of the mixture flowing from the trough in the moving conveyor inside the tunnel and lastly, formation of flexible polyurethane foam after blow off.

[0038] The flexible polyurethane slabstock foams produced are waited for a predetermined period, for example one day, for curing. After the waiting period ends, slabstock polyurethane foams are cut in desired sizes. This step is included to the physical production phase after the chemical production. In the first step, the mixture of 60-70 parts of visco polyether polyol by weight (its functionality is 3, its molecular weight is 700 g / mol, its number of OH is 250 mg KOH / g) and the composition of active carbon, microcrystalline cellulose and boron compound is prepared with 75-91% visco polyether polyol by weight, 1-6% active carbon by weight, 1-6% microcristalline cellulose by weight and 7-13% boron compound by weight. In the preferred embodiment of the invention, in the first step, visco polyether polyol and the composition of active carbon, microcristalline cellulose and boron compound comprise 84-88% visco polyether polyol by weight, 2-3% active carbon by weight, 2-3% microcristalline cellulose by weight and 8-10% boron compound by weight.

[0039] At the beginning, since the substances are solid and they are sent to the system with pump, the substances should be mixed with a liquid material, preferably with polyol by applying the first step in this way.

[0040] In the second step, 60-70 parts of visco poly ether polyol by weight (its functionality is 3, its molecular weight is 700 g / mol, its number of OH is 250 mg KOH / g) and the composition of active carbon, microcristalline cellulose and boron compound, polyether polyol comprising 20-30 parts of styrene acrylo nitrile by weight (its functionality is 3, its molecular weight is 2000 g / mol, its number of OH is 30 mg KOH / g), 10-20 parts of polyether polyol by weight (its functionality is 3, its molecular weight is 5000 g / mol, its number of OH is 33 mg KOH / g), 0.5-2 parts of water by weight, 0.8-2 parts of silicon by weight, 0.1-0.7 parts of amine catalysts by weight, 0.01-0.1 parts of tin catalyst by weight and 40-60 parts of diisocyanate by weight are pumped to the mixer.

[0041] Isocyanates mentioned in the second step are polycarbodiimide modified 4,4- diphenylmethane diisocyanate and / or carbodiimide-uretonimine modified 4,4- diphenylmethane diisocyanate and / or 4,4-diphenylmethane diisocyanate (pure MDI) and / or 2,4 and 4,4-diphenylmethane diisocyanate (MDI) with 80 / 20 ratio and / or polymeric MDI and / or 2,4 and 2,6 toluene diisocyanate with 80 / 20 ratio (TDI 80) and / or 2,4 and 2,6 toluene diisocyanate with 65 / 35 ratio (TDI 65).

[0042] Silicon used as the surface active agent provides formation of cells and homogeneous distribution of cells by decreasing surface tension.

[0043] The density of the foam obtained changes between 30-100 density. When the tunnel method is used, the products are taken as blocks, this provides more product to be obtained in a shorter time than mold method. Tunnel method is more efficient than mold method.

[0044] For being able to understand that foams obtained with said formulation and production process show antibacterial property, their antibacterial effects have been tested quantitatively according to the standard of ASTM E2149-01. Said test results have been shown in the

[0045] Table-2

[0046] Table-2: The antibacterial (Hygiene) values of the foam against Staphylococcus Aureus (ATCC 6538)

[0047] A bacteria suspension with a concentration of 6.4xl05(log 5,80) cfu / ml has been added to each sample in the Table-2. % bacteria values given as (+) show increase in the number of bacteria, % bacteria values given as (-) show decrease in the number of bacteria.

[0048] Said samples comprise 60-70 parts of visco polyether polyol by weight (its functionality is 3, its molecular weight is 700 g / mol, its number of OH is 250 mg KOH / g) and the composition of active carbon, microcristalline cellulose and boron compound comprising the mixture of 75-91% visco polyether polyol by weight, 1-6% active carbon by weight, 1- 6% microcristalline cellulose by weight and 7-13% boron compound by weight.

[0049] Sample 3 comprises visco polyether polyol and the composition of active carbon, microcristalline cellulose and boron compound comprising 2-3% active carbon by weight, 2-3% microcristalline cellulose by weight, 8-10% boron compound by weight and 84-88% visco polyether polyol by weight. For sample 3 having this content, as understood from the Table-2, it is seen that it shows the best effect with 90% decrease at the end of 24 hours in terms of antibacterial properties.

[0050] Industrial Applicability of the Invention

[0051] The invention is related to a formulation and production method for production of air permeable, moisture, sweat and odor absorber, antibacterial slabstock flexible polyurethane foam by using active carbon, boron compound and microcrystalline cellulose in predetermined amounts, and it is industrially applicable.

[0052] The invention is not limited to the descriptions above, a skilled person in the art can perform different embodiments of the invention easily. These should be interpreted within the protection scope of the invention claimed with the claims.

Claims

CLAIMS1. For gaining all the properties such as antibacterial, cooling and odor removing, moisture absorbing at the same time, a slabstock flexible polyurethane foam formulation comprising polyether polyol comprising 20-30 parts of styrene acrylo nitrile by weight (its functionality is 3, its molecular weight is 2000 g / mol, its number of OH is 30 mg KOH / g), 10-20 parts of polyether polyol by weight (its functionality is 3, its molecular weight is 5000 g / mol, its number of OH is 33 mg KOH / g), 0.5-2 parts of water by weight, 0.8-2 parts of silicon by weight, 0.1-0.7 parts of amine catalyst by weight, 0.01-0.1 parts of tin catalyst by weight and 40-60 parts of diisocyanate by weight; characterized by comprising 60-70 parts of visco polyether polyol by weight (its functionality is 3, its molecular weight is 700 g / mol, its number of OH is 250 mg KOH / g) and the composition of active carbon, microcrystalline cellulose and boron compound comprising the mixture of 75-91% visco poly ether polyol by weight, 1-6% active carbon by weight, 1-6% microcristalline cellulose by weight and 7-13% boron compound by weight.

2. Slabstock flexible polyurethane foam formulation according to claim 1, characterized by comprising visco polyether polyol and the composition of active carbon, microcrystalline cellulose and boron compound comprising 2-3% active carbon by weight, 2-3% microcrystalline cellulose by weight, 8-10% boron compound by weight and 84-88% visco polyether polyol by weight.

3. Slabstock flexible polyurethane foam formulation according to claim 2, characterized by isocyanate which can be polycarbodiimide modified 4,4-diphenylmethane diisocyanate and / or carbodiimide-uretonimine modified 4,4-diphenylmethane diisocyanate and / or 4,4-diphenylmethane diisocyanate (pure MDI) and / or 2,4 and 4,4- diphenylmethane diisocyanate (MDI) with 80 / 20 ratio and / or polymeric MDI and / or 2,4 and 2,6 toluene diisocyanate with 80 / 20 ratio (TDI 80) and / or 2,4 and 2,6 toluene diisocyanate with 65 / 35 ratio (TDI 65).

4. For gaining all the properties such as antibacterial, cooling and odor removing, moisture absorbing at the same time, production method of slabstock flexible polyurethane foam characterized by comprising the steps below with the order indicated:In the first step, mixing visco polyether polyol and the composition of active carbon, microcristalline cellulose and boron compound in predetermined percentages,In the second step, pumping visco polyether polyol and the composition of active carbon, microcristalline cellulose and boron compound used, polyether polyol comprising styrene acrylo nitrile, cell opener polyether polyol, amine catalysts, silicon, water, tin catalyst and diisocyanate in predetermined percentages to the mixer respectively, In the third step, mixing the mixture obtained with a high speed for a predetermined period, for example 1-2 seconds,In the fourth step, transferring the mixed mixture to the chamber (or trough) and raising of the mixture flowing from the trough in the moving conveyor inside the tunnel and lastly, formation of flexible polyurethane foam after blow off.

5. A method according to claim 4, characterized in that 60-70 parts of visco polyether polyol by weight (its functionality is 3, its molecular weight is 700 g / mol, its number of OH is 250 mg KOH / g) and the composition of active carbon, microcrystalline cellulose and boron compound mentioned in the first step is the mixture of 75-91% visco polyether polyol by weight, 1-6% active carbon by weight, 1-6% microcristalline cellulose by weight and 7-13% boron compound by weight.

6. A method according to claim 5, characterized in that visco poly ether polyol and the composition of active carbon, microcrystalline cellulose and boron compound mentioned in the first step is 84-88% visco polyether polyol by weight, 2-3% active carbon by weight, 2-3% microcrystalline cellulose by weight and 8-10% boron compound by weight.

7. A method according to claim 6, characterized in that 60-70 parts of visco polyether polyol by weight (its functionality is 3, its molecular weight is 700 g / mol, its number of OH is 250 mg KOH / g) and the composition of active carbon, microcristalline cellulose and boron compound, polyether polyol comprising 20-30 parts of styrene acrylo nitrile by weight (its functionality is 3, its molecular weight is 2000 g / mol, its number of OH is 30 mg KOH / g), 10-20 parts of cell opener poly ether polyol by weight (its functionality is 3, its molecular weight is 5000 g / mol, its number of OH is 33 mg KOH / g), 0.5-2 parts of water by weight, 0.8-2 parts of silicon by weight, 0.1-0.7 parts of amine catalysts by weight, 0.01-0.1 parts of tin catalyst by weight and 40-60 parts of diisocyanate by weight mentioned in the second step are pumped to the mixer.

8. A method according to claim 7, characterized in that there is isocyanate which can be polycarbodiimide modified 4,4-diphenylmethane diisocyanate and / or carbodiimide- uretonimine modified 4,4-diphenylmethane diisocyanate and / or 4,4-diphenylmethanediisocyanate (pure MDI) and / or 2,4 and 4,4-diphenylmethane diisocyanate (MDI) with 80 / 20 ratio and / or polymeric MDI and / or 2,4 and 2,6 toluene diisocyanate with 80 / 20 ratio (TDI 80) and / or 2,4 and 2,6 toluene diisocyanate with 65 / 35 ratio (TDI 65).

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