Functional eva sheet, method for manufacturing functional eva sheet, and mouthpiece for oral cavity

Abstract

To provide a functional EVA sheet which exhibits sufficient adsorption function and decomposition function for an adhered organic matter, compared to a conventional product of the same kind, and is flexible as a hole, and has good workability at the time of molding into a product and mountabilities to a human body, a method for manufacturing the same, and a mouthpiece for oral cavity using the functional EVA sheet.SOLUTION: A functional EVA sheet S1 is an EVA sheet where a photocatalyst apatite T having a plurality of powdery or granular photocatalyst capability is dispersed and embedded in at least one surface side of front and back sides, wherein each of the photocatalyst apatite T is composed of an exposure part T1a exposed to outside in an embedded state, and a non-exposure part T1b embedded in the sheet in a form of preventing fall-off to outside the sheet. A mouthpiece 1 for oral cavity has such a structure that is integrally molded by thermally welding an upper jaw mouthpiece part 12 and a lower jaw mouthpiece part 13 formed of the functional EVA sheet S1, and is airtight in an inward / outward direction of oral cavity.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a functional EVA sheet, a manufacturing method for the functional EVA sheet, and an oral mouthpiece. More specifically, the present invention relates to a functional EVA sheet that exhibits sufficient adsorption and decomposition functions for adsorbed (attached) organic matter compared to conventional products of the same type, has overall flexibility, and is easy to process when molded into products and to wear on the human body, a manufacturing method for the functional EVA sheet, and an oral mouthpiece using the functional EVA sheet. [Background technology]

[0002] The present inventor has conducted extensive research into oral mouthpieces and obtained a patent for an oral mouthpiece manufacturing method and an oral mouthpiece (Patent No. 6504992). According to the oral mouthpiece manufacturing method, it is possible to provide an oral mouthpiece that secures an airway by pulling the tongue root toward the inside of the oral cavity due to the vacuum effect that occurs when the mouthpiece is worn, thereby improving the symptoms of obstructive sleep apnea syndrome. Also, the oral mouthpiece secures an airway by pulling the tongue root toward the inside of the oral cavity due to the vacuum effect that occurs when the mouthpiece is worn, thereby improving the symptoms of obstructive sleep apnea syndrome. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6504992 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, the present inventors adopted sheet-shaped EVA (ethylene-vinyl acetate copolymer, hereinafter referred to as "EVA sheet"), a thermoplastic resin, as a soft resin material from the viewpoints of ease of processing and safety to the human body, and processed this to form the oral mouthpiece described above. The oral mouthpiece made of EVA sheet was easy to process and had good wearability.

[0005] However, while continuing to manufacture the oral mouthpieces made of the above-mentioned EVA sheets, the inventors became dissatisfied with the lack of antibacterial properties and the ease with which existing EVA sheets became discolored (easy discoloration). In particular, the oral mouthpieces they manufactured had discolored over time, which made them look unattractive. They were also dissatisfied with the effort of soaking the mouthpieces in disinfectant during storage and the slime that was felt when first put on due to the disinfectant.

[0006] Therefore, the inventors considered applying titanium oxide having photocatalytic properties to EVA sheets, but general titanium oxide does not have sufficient or insufficient adsorption and decomposition functions for organic substances. Next, titanium-doped apatite ((Ca,Ti) 10 (OH)2(PO4)6. Calcium hydroxyapatite (Ca 10 We focused on photocatalytic apatite (a composition containing (PO4)6(OH)2) and titanium (Ti; hereafter referred to as "photocatalytic apatite" in this specification and claims) and produced a sheet (prototype sheet 1) in which photocatalytic apatite was kneaded into EVA.

[0007] However, in the case of prototype sheet 1, the photocatalytic apatite was not mixed uniformly into the EVA during kneading, and it was difficult to expose the desired amount of photocatalytic apatite on the surface when the sheet was processed. In addition, prototype sheet 1 had a harder texture than a sheet that was not kneaded, and it lacked flexibility, making it difficult to process and causing an uncomfortable feeling when worn (reduced wearing comfort).

[0008] Next, the inventors produced a prototype sheet (Prototype Sheet 2) in which fine powdered photocatalytic apatite was sprayed onto the surface of an EVA sheet and fixed thereon. However, due to the liquid-repellent and powder-repellent properties of the EVA sheet, the photocatalytic apatite in Prototype Sheet 2 was prone to falling off.

[0009] The present invention has been devised in light of the above points, and aims to provide a functional EVA sheet which, compared with conventional similar products, exhibits sufficient adsorption and decomposition functions for adsorbed (attached) organic matter, is flexible overall, and has good processability when formed into products and wearability on the human body, a manufacturing method for said functional EVA sheet, and an oral mouthpiece using said functional EVA sheet. [Means for solving the problem]

[0010] In order to achieve the above-mentioned objective, the functional EVA sheet of the present invention is a sheet of EVA having a plurality of powdered or granular photocatalytic apatite particles having photocatalytic activity dispersed and embedded on at least one side of the front or back surface, and each of the photocatalytic apatite particles is composed of an exposed portion that is exposed to the outside while embedded, and a non-exposed portion that is embedded within the sheet in such a manner that it is unlikely to fall off outside the sheet.

[0011] The exposed parts of each photocatalytic apatite exhibit the organic matter adsorption and decomposition functions of the photocatalytic apatite, adsorbing and decomposing organic matter. As a result, if the functional EVA sheet is dried in the sun (exposed to sunlight) without being immersed in a disinfectant, the adsorbed (attached) organic matter is decomposed by the photocatalytic reaction caused by ultraviolet rays, and the sheet can be kept clean while preventing discoloration caused by the organic matter. For example, the sheet can be used favorably in sanitary products such as oral mouthpieces and compression belts (for lower back pain, etc.) made by processing the sheet.

[0012] The unexposed parts of each photocatalytic apatite are embedded in the EVA sheet, and the engagement force generated at the contact points with the EVA sheet keeps the embedded state and prevents it from falling off. Also, photocatalytic apatite has a lower decomposition effect on resin components than titanium oxide, so it is prevented from falling off the EVA sheet due to deterioration caused by the decomposition force.

[0013] Furthermore, the above-mentioned functional EVA sheet has each photocatalytic apatite disposed only on the surface portion of the EVA sheet, and compared to sheets in which the photocatalytic apatite is mixed throughout the EVA sheet, including deeper within, the flexibility of the EVA sheet as a whole is not lost, and it is also easy to process when formed into products and easy to wear on the human body.

[0014] The surface on which the photocatalytic apatite is embedded may be at least one of the front side or the back side, or may be both the front and back sides. The photocatalytic apatite may be at least either powdery or granular, and may be a mixture of powdery and granular photocatalytic apatite.

[0015] Furthermore, the range of the exposed portion of the functional EVA sheet of the present invention described above may be 10% to 60% of the surface of each photocatalytic apatite. In this case, if the exposed portion is within the above-mentioned numerical range, the photocatalytic apatite's organic matter adsorption and decomposition functions are fully exhibited, and organic matter is adsorbed and decomposed more efficiently.

[0016] According to the inventor's tests, when the exposed portion is less than 10% of the surface of the photocatalytic apatite, it is not preferable because the organic matter adsorption and decomposition functions will not be sufficiently exerted, and when the exposed portion is more than 60% of the surface of the photocatalytic apatite, the buried portion (in other words, the unexposed portion) will be reduced and the effect of inhibiting falling off from the EVA sheet will be reduced, which is also not preferable.

[0017] Furthermore, in order to ensure sufficient organic matter adsorption and decomposition performance and sufficient retention by the EVA sheet, it is more preferable that the range of the exposed portion mentioned above be 30% or more and 50% or less of the surface of the photocatalytic apatite.

[0018] Furthermore, the functional EVA sheet of the present invention described above may be one in which the number of poorly exposed areas, where the exposed area is less than 10% of the surface of the photocatalytic apatite, is less than 30% of the total number of photocatalytic apatite. In this case, even if the functional EVA sheet has the poorly exposed areas described above, it can still exhibit sufficient organic matter adsorption and decomposition performance.

[0019] However, due to errors in the manufacturing process or other reasons, functional EVA sheets may have (exist) poorly exposed areas in which some of the photocatalytic apatite is either completely unexposed (completely buried within the EVA sheet) or the exposed area is less than 10% of the surface of the photocatalytic apatite. If there are a large number of poorly exposed areas, the organic matter adsorption and decomposition functions will not be exerted at all or will be exerted only insufficiently.

[0020] However, after extensive research, the present inventors have found that if the poorly exposed areas in the functional EVA sheet are less than 30% of the total amount of embedded photocatalytic apatite (in other words, if the above-mentioned exposed areas (areas where 10% or more of the embedded photocatalytic apatite is exposed to the outside) in the functional EVA sheet are 70% or more (within the range of 70% to 100%) of the total amount of embedded photocatalytic apatite), the organic matter adsorption performance and organic matter decomposition performance can be fully demonstrated. For this reason, it is preferable for the poorly exposed areas of the functional EVA sheet to be less than 30% of the total amount of embedded photocatalytic apatite.

[0021] In order to achieve the above object, the manufacturing method of the functional EVA sheet of the present invention comprises a first step of heating and softening an area in an EVA sheet before processing, in which powdered or granular photocatalytic apatite having photocatalytic activity is to be embedded; a second step of substantially uniformly applying an aqueous solution containing powdered or granular photocatalytic apatite to the area in the heated EVA sheet after the first step; a third step of drying the applied aqueous solution on the coating surface of the coated EVA sheet formed after the second step; and a fourth step of applying a pressing member to the coating surface of the dried EVA sheet formed after the third step, while at least the coating surface is still soft, with a pressing force sufficient to embed the photocatalytic apatite in the EVA sheet.

[0022] In the first step, the area of ​​the EVA sheet before processing where powdered or granular photocatalytic apatite is to be embedded is heated and softened. The EVA sheet before processing is liquid- and powder-repellent, and even if powdered or granular photocatalytic apatite is scattered or an aqueous solution containing photocatalytic apatite is applied without processing, the fixation (embedding) of the photocatalytic apatite is extremely difficult, but by heating (preheating) and softening the surface of the EVA sheet, the liquid- and powder-repellent properties are reduced, making it easier to fix (embedding) the photocatalytic apatite.

[0023] In the second step, the aqueous solution of the photocatalytic apatite described above is applied approximately uniformly to the area of ​​the heated EVA sheet that has been through the first step, making it easier for the photocatalytic apatite to be distributed evenly than if powdered or granular photocatalytic apatite were simply scattered over it.

[0024] In the third step, the applied aqueous solution is dried (in other words, the water is evaporated) on the coated surface of the EVA sheet after coating, so that only powdered or granular photocatalytic apatite remains on the coated surface.

[0025] In the fourth step, after drying, while at least the coated surface of the EVA sheet is still soft, a pressing member is applied to the coated surface with a pressing force sufficient to embed the photocatalytic apatite within the EVA sheet, thereby embedding the photocatalytic apatite within the EVA sheet.

[0026] According to the manufacturing method of the functional EVA sheet of the present invention which includes each of the steps described above, the exposed portions of each photocatalytic apatite exhibit the organic matter adsorption and organic matter decomposition functions of the photocatalytic apatite, and a functional EVA sheet which adsorbs and decomposes organic matter can be obtained.

[0027] The functional EVA sheet obtained by the manufacturing method of the present invention can be dried in the sun (exposed to sunlight) without being immersed in a disinfectant, and the adsorbed (attached) organic matter is decomposed by a photocatalytic reaction caused by ultraviolet rays, thereby suppressing discoloration caused by the organic matter and keeping the sheet clean. Therefore, the functional EVA sheet can be suitably used for, for example, hygiene products such as oral mouthpieces and compression belts (for lower back pain, etc.) made by processing the sheet.

[0028] The unexposed parts of each photocatalytic apatite are embedded in the EVA sheet, and the engagement force generated at the contact points with the EVA sheet keeps the embedded state and prevents it from falling off. Also, photocatalytic apatite has a lower decomposition effect on resin components than titanium oxide, so it is prevented from falling off the EVA sheet due to deterioration caused by the decomposition force.

[0029] Furthermore, the functional EVA sheet obtained by the manufacturing method of the present invention has each photocatalytic apatite disposed only on the surface portion of the EVA sheet, and compared to a sheet in which the photocatalytic apatite is mixed throughout the EVA sheet, including deeper within, the flexibility of the EVA sheet as a whole is not lost, and it is also easy to process when formed into products and easy to wear on the human body.

[0030] The surface on which the photocatalytic apatite is embedded may be at least one of the front side or the back side, or may be both the front and back sides. The photocatalytic apatite may be at least either powdery or granular, and may be a mixture of powdery and granular photocatalytic apatite.

[0031] In the above-mentioned first step, the means or method for heating and softening the surface of the EVA sheet before processing is not particularly limited, and for example, a heat irradiation lamp, a high-temperature air blower, a dryer, or the like may be used, or a heating method using a burner, etc. may also be used.

[0032] In the second step described above, a coating machine is preferably used to apply the aqueous solution containing the photocatalytic apatite since it is easy to apply the solution uniformly, but the means or method are not particularly limited, and application by a brush or the like is not excluded.

[0033] In the above-mentioned third step, the means or method for drying the aqueous solution containing the photocatalytic apatite is not particularly limited, and for example, a means such as a blower or dryer may be used. Also, in order to make the "coated surface soft" in the above-mentioned fourth step, a means or method for drying the coated surface and making the coated surface soft may be adopted, and for example, a means such as a high-temperature blower or dryer may be used, or a drying method using a burner or the like may be used.

[0034] In the aforementioned fourth step, the pressing member applied to the coating surface is not particularly limited as long as it is a member capable of pressing with a pressing force sufficient to embed the photocatalytic apatite in the EVA sheet, and examples thereof include a member with a flat pressing surface, at least a pair of roller members between which the EVA sheet can pass, a member having a roller between which the EVA sheet can pass and a flat pressing surface, etc. Furthermore, in order to soften the coating surface or to enable the coating surface to be maintained in a soft state, the pressing member itself may be equipped with a heating capacity such as a heater.

[0035] Furthermore, in the above-mentioned method for producing a functional EVA sheet of the present invention, the content of photocatalytic apatite in the aqueous solution may be 25% by mass or more and 45% by mass or less. In this case, since the solvent is water, the powdery or granular photocatalytic apatite, which is the solute, is easily dissolved uniformly, making it easier to apply the aqueous solution in the above-mentioned second step and easier to form a substantially uniform coating surface.

[0036] In the third step, water, which is the solvent, evaporates easily, which leads to a reduction in work time, and since nothing remains on the coating surface after evaporation other than the solute photocatalytic apatite, there is no need to consider the adverse effects of residues on the human body when the processed product of the functional EVA sheet obtained by the manufacturing method of the present invention is a sanitary product such as an oral mouthpiece. Furthermore, since the content of photocatalytic apatite in the aqueous solution is within the aforementioned numerical range, it is possible to achieve a sufficient amount of photocatalytic apatite distribution with little unevenness and good coating properties.

[0037] Incidentally, if the photocatalytic apatite content in the aqueous solution is less than 25 mass %, the aqueous solution will flow on the coated surface due to excess moisture, which is likely to result in uneven distribution of photocatalytic apatite on the coated surface after drying, and the amount of photocatalytic apatite required to cause a photocatalytic reaction will be insufficient or slightly insufficient, which is undesirable.

[0038] On the other hand, if the photocatalytic apatite content in the aqueous solution exceeds 45 mass %, the viscosity of the photocatalytic apatite aqueous solution will increase, making it prone to clogging when a paint sprayer is used, and even when painting with a brush, the spread of the aqueous solution will decrease, making the paint prone to unevenness, reducing workability. Furthermore, although the amount of photocatalytic apatite required to cause a photocatalytic reaction is sufficient, the surface will harden and flexibility will decrease, which is undesirable in terms of workability when formed into products and wearability on the human body.

[0039] In the above-mentioned method for producing a functional EVA sheet of the present invention, the steps from step 1 to step 4 may be repeated two or three times. In this case, a functional EVA sheet can be produced in which the organic adsorption performance and organic decomposition performance are further improved and the flexibility of the sheet is sufficiently ensured.

[0040] Initially, the inventors thought that by increasing the amount of embedded photocatalytic apatite when manufacturing a functional EVA sheet, sufficient organic adsorption and decomposition performance could be achieved, and so they conducted a test in which steps 1 to 4 of the above-mentioned manufacturing method for the functional EVA sheet were repeated multiple times (hereinafter referred to as "repeated execution").

[0041] As a result, it was found that increasing the number of repeated applications increases the total amount of embedded photocatalytic apatite, but also increases the hardness of the sheet. It was also found that as the hardness of the sheet increases, its workability decreases, and when processed into products (especially those worn on the human body), the lack of flexibility causes pain and other discomfort when worn (in other words, the fit decreases).

[0042] In addition, for the exposed portions of the photocatalytic apatite that was embedded the first time (for example, the first time), when the number of repeated applications increases from the next time onwards (for example, the fourth time), the melted portions of the EVA sheet caused by the processing performed from the fourth time onwards overlap, and there were many cases in which the initially embedded photocatalytic apatite was completely unexposed (completely buried in the EVA sheet) or had insufficient exposure, which did not necessarily lead to an improvement in the organic matter adsorption and decomposition performance.

[0043] As a result of extensive research by the inventors, it was found that the number of times that can ensure that there are no exposed parts of the initially embedded photocatalytic apatite or that there are few insufficiently exposed parts, and that the flexibility of the sheet is sufficiently ensured, is at most 3 times, and more preferably 2 times. When the number of repeated operations is within the aforementioned number of times (2 to 3 times), a functional EVA sheet can be manufactured that has further improved organic matter adsorption performance and organic matter decomposition performance, and that ensures sufficient flexibility of the sheet.

[0044] In order to achieve the above-mentioned object, the oral mouthpiece of the present invention is an EVA sheet having a plurality of powdered or granular photocatalytic apatites having photocatalytic activity dispersed and embedded on at least one side of the front or back surface, and each of the photocatalytic apatites uses a functional EVA sheet consisting of an exposed portion that is exposed to the outside in an embedded state, and a non-exposed portion that is embedded within the sheet in a manner that makes it difficult for them to fall off outside the sheet, and the mouthpiece comprises upper and lower mouthpiece parts modeled with the functional EVA sheet based on a previously created dental model of the wearer's upper and lower jaws, and the upper and lower mouthpiece parts are integrated in an arrangement that allows the wearer to maintain a centric occlusion position, with a heat-welded portion that is continuously heat-welded between the left molar and the right molar, to form an airtight structure in both the inside and outside of the oral cavity.

[0045] The oral mouthpiece described above is formed using a functional EVA sheet, and the exposed portions of the photocatalytic apatite in the functional EVA sheet exert the organic matter adsorption and decomposition functions of the photocatalytic apatite, adsorbing and decomposing organic matter. As a result, if the oral mouthpiece described above is dried in the sun (exposed to sunlight) without being immersed in a disinfectant, the adsorbed (attached) organic matter is decomposed by the photocatalytic reaction caused by ultraviolet rays, and coloring caused by organic matter is suppressed and the mouthpiece can be kept clean.

[0046] The non-exposed portions of each photocatalytic apatite are those portions where the photocatalytic apatite bites into the oral mouthpiece (EVA sheet) and maintains the embedded state by the engagement force generated at the contact portion with the oral mouthpiece (EVA sheet), thereby preventing it from falling off. Furthermore, photocatalytic apatite has a lower decomposition effect on resin components compared to titanium oxide, so falling off from the EVA sheet due to deterioration caused by the decomposition force is prevented. In other words, the oral mouthpiece of the present invention can prevent the photocatalytic apatite from falling off into the oral cavity when worn.

[0047] Furthermore, the above-mentioned functional EVA sheet has each photocatalytic apatite disposed only on the surface portion of the EVA sheet, and compared to sheets in which the photocatalytic apatite is mixed throughout the EVA sheet, including deeper within, the flexibility of the EVA sheet as a whole is not lost, and it is also easy to process when molded into an oral mouthpiece and easy to wear on the human body (oral cavity).

[0048] In the oral mouthpiece described above, the upper and lower mouthpiece parts are modeled based on the wearer's upper and lower jaw dental models, so they fit well, and because they are modeled from the aforementioned functional EVA sheet, which is a soft resin, pain felt when wearing them is unlikely to occur. In addition, the upper and lower mouthpiece parts after being combined are positioned so that the wearer can maintain the centric occlusion position, reducing the possibility of side effects such as toothache, jaw pain, and changes in bite alignment seen in sleep splint therapy.

[0049] Furthermore, the upper mouthpiece part and the lower mouthpiece part are integrated with each other so that the part between the left molar and the right molar is continuously heat-welded to be airtight in the inside and outside of the oral cavity, which makes it impossible to breathe through the mouth, and reduces the possibility of side effects such as dry mouth and excessive saliva production seen in sleep splint therapy.In addition, by wearing the above-mentioned oral mouthpiece that is airtight in the inside and outside of the oral cavity, the oral cavity of the wearer who breathes through the nose is repeatedly put into a negative pressure state every time he or she inhales air, and under this negative pressure state, the tongue root is pulled up to the inside of the oral cavity, and the airway is secured.

[0050] More specifically, since mouth breathing is no longer possible, the wearer must breathe through the nose, and the inhaled air travels from the nasal cavity through the pharynx to the trachea. However, every time the wearer inhales, the air in the sealed oral cavity is drawn through the pharynx to the trachea, creating a negative pressure in the oral cavity. When the oral cavity is in a negative pressure state, a suction force is generated toward the back of the oral cavity (in the direction of the anterior teeth, oral vestibule, and hard palate) as viewed from the pharynx, and the entire tongue is pulled up, and the tongue base is also pulled up inside the oral cavity. Obstructive sleep apnea is caused by the tongue base blocking the airway due to muscle relaxation caused by sleep, but as described above, by wearing the oral mouthpiece of the present invention, the tongue base is pulled up inside the oral cavity by the vacuum effect generated when wearing the mouthpiece, securing the airway, and improving the symptoms of obstructive sleep apnea syndrome. Effect of the Invention

[0051] The functional EVA sheet, the manufacturing method for the functional EVA sheet, and the oral mouthpiece of the present invention have a simple structure compared to conventional similar products, yet exhibit sufficient adsorption and decomposition functions for adsorbed (attached) organic matter, and are flexible overall, making them easy to process when molded into products and easy to wear on the human body. [Brief description of the drawings]

[0052] [Figure 1] 1 is an enlarged image of a functional EVA sheet according to the present invention. [Diagram 2]FIG. 2 is a schematic diagram showing a plurality of embedded states of photocatalytic apatite in the functional EVA sheet shown in FIG. 1, with the photocatalytic apatite particles being enlarged for ease of explanation. [Diagram 3] FIG. 2 is a side view of the oral mouthpiece of the present invention. [Figure 4] 4 is a perspective view showing upper and lower dental casts produced in a manufacturing process of the oral mouthpiece of FIG. 3. FIG. [Diagram 5] FIG. 5 shows the process of creating mouthpiece parts from the dental model shown in FIG. 4, where (a) is an explanatory oblique view of a sheet-like mouthpiece part modeled from the dental model, and (b) is an explanatory oblique view of the mouthpiece part cut away from the sheet. [Figure 6] FIG. 5 is an explanatory diagram showing, from the side, a state in which the upper and lower dental models shown in FIG. 4 are attached to an articulator with guide pins, with a part enlarged. [Figure 7] FIG. 7 is an explanatory diagram showing, from the side, a state in which mouthpiece parts are attached to cover each dental cast attached to the articulator with guide pins shown in FIG. 6, with a part enlarged. [Figure 8] FIG. 7 is an explanatory diagram showing, from a side, a state in which contact portions of the upper and lower mouthpiece parts are thermally welded in the articulator with guide pins shown in FIG. 6, with a part enlarged. [Figure 9] FIG. 4 shows the state of the pharynx and airflow during sleep in a patient with obstructive sleep apnea syndrome, where (a) shows a patient not wearing an oral mouthpiece, and (b) shows a patient wearing the oral mouthpiece shown in FIG. 3, illustrating the usage state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0053] The embodiments of the present invention will be described in more detail with reference to Figures 1 to 9. Furthermore, the reference numerals in each drawing are given within the scope of reducing complexity and facilitating understanding, and when multiple equivalent parts are given the same reference numerals, the reference numerals may be given to only some of them.

[0054] [Functional EVA sheet] The functional EVA sheet S will be described with reference to FIGS. The functional EVA sheet S1 is a sheet of EVA (S2) having thermoplasticity with a plurality of fine powders of photocatalytic apatite T dispersed and embedded on both sides. In Fig. 1, the lower transparent or semi-transparent part is the area where photocatalytic apatite T is not embedded, and the middle to upper whitish parts are the areas where photocatalytic apatite T is embedded.

[0055] Please refer to Fig. 2. Each of the embedded photocatalytic apatite T is composed of an exposed portion T1a that is exposed to the outside while embedded, and a non-exposed portion T1b that is embedded in the sheet in such a manner that it is unlikely to fall out of the EVA (S2) sheet.

[0056] In the functional EVA sheet S1, the exposed portions T1a of the photocatalytic apatite T normally embedded as intended (hereinafter referred to as "normal photocatalytic apatite portions T1") are provided so as to occupy 10% to 60% of the surface of the normal photocatalytic apatite portions T1. The functional EVA sheet S1 is provided so that the amount of poorly exposed photocatalytic apatite T (hereinafter referred to as "defective photocatalytic apatite portions T2", which correspond to the above-mentioned "poorly exposed portions") is less than 30% of the total amount of photocatalytic apatite T.

[0057] For example, in the photocatalytic apatite T1 located at the leftmost position in Fig. 2, the exposed portion T1a is about 40% of the surface of the normal portion T1 of the photocatalytic apatite, and the unexposed portion T1b is about 60% of the surface of the normal portion T1 of the photocatalytic apatite, which corresponds to the normal portion T1 of the photocatalytic apatite. In addition, in the photocatalytic apatite T1 located second from the left in Fig. 2, the exposed portion T1a is about 25% of the surface of the normal portion T1 of the photocatalytic apatite, and the unexposed portion T1b is about 75% of the surface of the normal portion T1 of the photocatalytic apatite, which also corresponds to the normal portion T1 of the photocatalytic apatite.

[0058] On the other hand, the photocatalytic apatite T located third from the left in Fig. 2 has exposed portion T2a that is approximately 8% of the surface of the photocatalytic apatite T1, and non-exposed portion T2b that is approximately 92% of the surface of the photocatalytic apatite T1, so this corresponds to the defective photocatalytic apatite portion T2. ​​And the photocatalytic apatite T located fourth from the left (rightmost) in Fig. 2 has no exposed portion (T2a) and consists only of non-exposed portion T2b, so this also corresponds to the defective photocatalytic apatite portion T2.

[0059] [Method of manufacturing functional EVA sheet] The method for producing a functional EVA sheet includes the following first to fourth steps, which are repeated twice.

[0060] (1) In the first step, an operation is performed to heat and soften the area of ​​the EVA (S2) sheet before processing, in which the fine powder of photocatalytic apatite T is to be embedded. In this embodiment, the surface of the EVA (S2) sheet is heated and softened by a burner, but as described above, other means or methods such as a heat irradiation lamp may be used.

[0061] (2) In the second step, an aqueous solution containing fine powder of photocatalytic apatite T is applied substantially uniformly to the area of ​​the heated EVA (S2) sheet that has been subjected to the first step where the fine powder of photocatalytic apatite T is to be embedded.

[0062] In this embodiment, the photocatalytic apatite used is "PHOTOHAP PCAP-100 (product name, manufactured by Taihei Chemical Industry Co., Ltd.)", but this is not limited to this and similar products from other companies may be used. In this embodiment, the aqueous solution contains 30% by mass of photocatalytic apatite T and 70% by mass of water (set so that the total of photocatalytic apatite T and water is 100% by mass) in order to ensure good workability and quality (to prevent clogging of the nozzle hole of the applicator used for application and to achieve uniform distribution of photocatalytic apatite T after drying).

[0063] In this embodiment, the application of the aqueous solution described above is carried out using a coating machine, but as described above, other means or methods such as application with a brush, etc. may also be used. When a coating machine is not used, there is no need to consider clogging of the nozzle hole, so the aqueous solution described above may be of a higher concentration (for example, 31 to 45% by mass of photocatalytic apatite T and 55 to 69% by mass of water, with the total of water and photocatalytic apatite T being set to 100% by mass).

[0064] (3) In the third step, the water content of the aqueous solution applied to the coated surface of the coated EVA (S2) sheet formed through the second step is dried (evaporated). In this embodiment, the coated surface of the aqueous solution is dried by a dryer, but as described above, it may be dried by a means or method such as a blower.

[0065] (4) In the fourth step, while the coated surface of the dried EVA (S2) sheet formed through the third step is still soft, a pressing member is applied to the coated surface, and the photocatalytic apatite T is pressed with a pressing force sufficient to embed the EVA (S2) sheet. Note that in this embodiment, the pressing member uses a pair of heated roller members through which the EVA sheet can pass and the gap can be adjusted (to form the sheet to the desired thickness), but other pressing members or other means or methods as described above may also be used.

[0066] (effect) The operation of the method for producing a functional EVA sheet will be described, and the operation of the functional EVA sheet obtained thereby will be described.

[0067] In the first step, the liquid repellency and powder repellency are reduced by heating (preheating) and softening the surface of the EVA (S2) sheet, making it easier to fix (embed) the photocatalytic apatite T.

[0068] The second step makes it easier to distribute the photocatalytic apatite T evenly compared to simply scattering fine powder photocatalytic apatite. And since the solvent of the above-mentioned aqueous solution is water, the solute photocatalytic apatite is easily dissolved evenly, the aqueous solution is easy to apply, and a substantially uniform applied surface is easily formed.

[0069] Furthermore, since the aqueous solution has the above-mentioned formulation, uneven distribution of the photocatalytic apatite is unlikely to occur on the surface to which the aqueous solution is applied, the amount of photocatalytic apatite required to cause a photocatalytic reaction is sufficient, the viscosity is such that it does not cause clogging or the like when a coating machine is used, so workability is not impaired, and the aqueous solution is flexible, and the processability when formed into products and the wearability on the human body are good.

[0070] In the third step, the coating surface dries as the water evaporates, and only the fine powder of photocatalytic apatite T remains on the coating surface. At this time, the solvent water evaporates easily, which leads to a reduction in work time, and furthermore, since nothing remains on the coating surface after evaporation other than the solute photocatalytic apatite, there is no need to consider the adverse effects of residues on the human body when the processed product of the functional EVA sheet S1 obtained by this manufacturing method is a hygiene product such as an oral mouthpiece.

[0071] In the fourth step, the photocatalytic apatite T is embedded in the EVA (S2) sheet.

[0072] By repeating the manufacturing method including each of the above-mentioned steps twice, a functional EVA sheet S1 can be obtained in which the organic adsorption performance and organic decomposition performance are further improved and the flexibility of the sheet is sufficiently ensured.

[0073] In the obtained functional EVA sheet S1, the exposed portion T1a of each of the photocatalytic apatite T exerts the organic matter adsorption and organic matter decomposition functions of the photocatalytic apatite, adsorbing and decomposing organic matter. As a result, if the functional EVA sheet S1 is dried in the sun (exposed to sunlight) without being immersed in a disinfectant, the adsorbed (attached) organic matter is decomposed by a photocatalytic reaction caused by ultraviolet rays, and coloring caused by the organic matter is suppressed and the sheet can be kept clean, so that the sheet can be suitably used, for example, for sanitary products made by processing the sheet.

[0074] The non-exposed portion T1b of each of the photocatalytic apatite T is embedded in the EVA (S2) sheet, and the engagement force generated at the contact portion with the EVA (S2) sheet keeps the embedded state and prevents it from falling off (see Fig. 2). Also, since photocatalytic apatite T has a lower decomposition effect on resin components compared to titanium oxide, it is prevented from falling off from the EVA (S2) sheet due to deterioration caused by the decomposition force.

[0075] The functional EVA sheet S1 has photocatalytic apatite T disposed only on the surface portion of the EVA (S2) sheet, and compared to a sheet in which the photocatalytic apatite is mixed throughout the EVA sheet, including deep within, the flexibility of the EVA sheet as a whole is not lost, and it is also easy to process when formed into a product and easy to wear on the human body.

[0076] As described above, the functional EVA sheet S1 is provided such that the exposed portion T1a of the normal portion T1 of the photocatalytic apatite is 10% to 60% of the surface of the normal portion T1 of the photocatalytic apatite. This allows the photocatalytic apatite T to fully exert its organic matter adsorption and decomposition functions, efficiently adsorbing and decomposing organic matter, while the photocatalytic apatite T exerts a sufficient effect of suppressing falling off from the EVA (S2) sheet.

[0077] Furthermore, as described above, the functional EVA sheet S1 is provided such that the number of defective photocatalytic apatite sites T2 in each of the photocatalytic apatite T is less than 30% of the total number of the photocatalytic apatite T. As a result, even if the functional EVA sheet S1 has defective photocatalytic apatite sites T2, it is possible to exhibit sufficient organic matter adsorption performance and organic matter decomposition performance in terms of quantity.

[0078] [Oral mouthpiece 1] The oral mouthpiece 1 will be described with reference to Fig. 3. The oral mouthpiece 1 is formed by integrally molding an upper jaw mouthpiece part 12 and a lower jaw mouthpiece part 13, which are formed from a functional EVA sheet S1, by thermally welding them together, and this thermally welded part is set at a position where the wearer can maintain a centric occlusion position and a mandibular rest position, and is airtight in both the inside and outside of the oral cavity.

[0079] (Method of manufacturing oral mouthpiece 1) A method for producing the oral mouthpiece 1 will be described with reference to Figs.

[0080] (1) Dental model making process First, dental models of the upper and lower jaws of the wearer H are created. This process is the same as the process of creating dental models performed in dental treatment, etc. Specifically, impression material is placed on a tray used in dentistry to take impressions, and the tray is placed in the mouth of the wearer H to take impressions of the upper and lower jaws, and so-called female models of the dental models are created. Plaster or the like is poured into the created female models of the upper and lower jaws, and the ones that are removed after hardening (so-called male models) become the upper jaw dental model M1 and the lower jaw dental model M2 (see Figure 4).

[0081] (2) Mouthpiece parts production process Based on the upper jaw dental model T1 and the lower jaw dental model T2 created in the above-mentioned step (1), the upper and lower jaw mouthpiece parts (reference numerals 12, 13) are created separately. In this embodiment, each mouthpiece part is created using a vacuum former (not shown). The upper jaw dental model M1, the lower jaw dental model M2, and the functional EVA sheet S1 are set in the vacuum former, and heating and vacuum suction are performed. The upper jaw dental model M1 and the lower jaw dental model M2 are positioned so that the tips of the teeth face the functional EVA sheet S1 side.

[0082] At this time, the heated functional EVA sheet S1 is deformed by vacuum suction to conform to the outer shapes of the teeth and gums of the upper jaw dental model M1 and the lower jaw dental model M2 (i.e., the functional EVA sheet S1 models the shapes of the upper jaw dental model M1 and the lower jaw dental model M2), and as a result, the mouthpiece part prototypes for the upper and lower jaws are formed on one molded functional EVA sheet S3 (originally the functional EVA sheet S1) shown in Figure 5(a). Then, by cutting each of the mouthpiece part prototypes from the molded functional EVA sheet S3, the part modeled after the upper jaw dental model M1 becomes the upper jaw mouthpiece part 12, and the part modeled after the lower jaw dental model M2 becomes the lower jaw mouthpiece part 13 (see Figure 5(b)).

[0083] (3) Preparation process for gluing mouthpiece parts Each of the maxillary dental model M1 and the mandibular dental model M2 is attached to an articulator D with guide pins. The attached maxillary dental model M1 and mandibular dental model M2 are adjusted to be in centric occlusion, and the arrangement of the maxillary dental model M1 and the mandibular dental model M2 is further adjusted to be in the mandibular rest position (see FIG. 6). At this time, the floating of the lower end of the guide pin G that occurs when the maxillary dental model M1 and the mandibular dental model M2 are closed is adjusted to 0 mm (see the enlarged portion of FIG. 6).

[0084] The articulator D with guide pins shown in Figures 6 to 8 is commonly used in the dental laboratory industry, so a description of its function will be omitted, but it is assumed to have the position adjustment function and occlusion confirmation function using guide pins that are common to articulators with guide pins.

[0085] This step is performed as a preparation before bonding the upper jaw mouthpiece part 12 and the lower jaw mouthpiece part 13 created in step (2). This work is for adjusting the positions of the upper jaw dental model M1 and the lower jaw dental model M2, which serve as the mounting base for the articulator D with guide pins used during the bonding work, so that the positioning of the upper jaw mouthpiece part 12 and the lower jaw mouthpiece part 13 after bonding is optimal for the wearer.

[0086] Next, the upper jaw mouthpiece part 12 is attached to the upper jaw dental model M1, and the lower jaw mouthpiece part 13 is attached to the lower jaw dental model M2 so as to cover them (see FIG. 7). When the articulator D with guide pins is closed in this state so that the upper jaw dental model M1 and the lower jaw dental model M2 mesh with each other, the guide pins G float at a height equivalent to the thickness of the teeth of the upper jaw mouthpiece part 12 and the lower jaw mouthpiece part 13 (approximately 2 to 4 mm) (see the enlarged portion of FIG. 7).

[0087] (4) Finishing the mouthpiece Open the articulator D with guide pins, and heat the areas of the upper jaw mouthpiece part 12 and the lower jaw mouthpiece part 13 that come into contact with each other when biting with a handy gas burner or the like until they can be welded together. Then close the articulator D with guide pins again to bring the upper jaw mouthpiece part 12 and the lower jaw mouthpiece part 13 into contact with each other (see Figure 8).

[0088] Next, the articulator D with guide pins is pressed from above, and the upper jaw mouthpiece part 12 and the lower jaw mouthpiece part 13 are integrated (thermal welded) so that the floating of the lower end of the guide pin G is 2 mm or less (as close to 0 mm as possible, see the enlarged part in Fig. 8) and the contact parts of the upper jaw mouthpiece part 12 and the lower jaw mouthpiece part 13 are airtight in the inside and outside of the oral cavity (see Fig. 8). Note that "2 mm or less (as close to 0 mm as possible)" is stated from the viewpoint that it is better to make the thickness of the contact parts of each mouthpiece part as small as possible in order to reproduce the centric occlusion position and the mandibular rest position of the wearer's upper and lower jaws when worn, and does not exclude the case where it exceeds 2 mm, but if it exceeds 2 mm, it may cause side effects such as discomfort in the oral cavity and change in bite, which is not preferable.

[0089] Here, in order to bring the floating of the lower end of the guide pin G closer to 0 mm, for example, (a) the contact area between the upper jaw mouthpiece part 12 and the lower jaw mouthpiece part 13 is heated with a handy gas burner or the like until it can be welded, and the tips of the upper jaw dental model M1 and the lower jaw dental model M2 bite into and break through the molten contact area between the upper jaw mouthpiece part 12 and the lower jaw mouthpiece part 13, opening a hole in part of the area where the upper jaw dental model M1 and the lower jaw dental model M2 come into contact (i.e., a hole is opened in a part of the contact area to connect the inner spaces of the upper jaw mouthpiece part 12 and the lower jaw mouthpiece part 13). or (a) heating one of the contacting portions of the upper jaw mouthpiece part 12 and the lower jaw mouthpiece part 13 with a handy gas burner or the like until it can be welded, and then pressing the contacting portion of the heated mouthpiece part against the unheated mouthpiece part so that the lower end of the guide pin G is pressed into the contacting portion until the float of the lower end of the guide pin G is 0 mm, thereby integrating the two parts so that they are airtight in both directions of the oral cavity.

[0090] When the integrated upper jaw mouthpiece part 12 and lower jaw mouthpiece part 13 are removed from the articulator D with guide pins (in other words, the upper jaw dental model M1 and the lower jaw dental model M2), the oral mouthpiece 1 is obtained.

[0091] In this embodiment, the impression material used is an alginate impression material, an agar impression material, etc., but is not particularly limited as long as it is a material that can be used to form a dental model. In addition, in this embodiment, the material used to form the dental model is gypsum, but is not limited to this, and may be, for example, any material that can be used to form a dental model, such as various synthetic resins, and more preferably, a material that has a certain degree of heat resistance (heat resistance that can withstand the temperature of a heated soft resin sheet).

[0092] In this embodiment, a vacuum former is used to form the mouthpiece parts, but the present invention is not limited to this, and for example, a heated functional EVA sheet may be pressed against the created dental model and manually molded to fit the mold. In addition, in this embodiment, a process of creating dental models of the upper and lower jaws of the wearer is provided prior to the process of individually forming each mouthpiece part corresponding to the upper and lower jaws, but the present invention is not limited to this, and for example, the process of creating the dental models may be outsourced.

[0093] (effect) The function of the oral mouthpiece 1 will be described with reference to FIG. In Fig. 9(a), arrows indicate the state of the pharynx and airflow during sleep of a patient with obstructive sleep apnea syndrome who is not wearing an oral mouthpiece (hereafter referred to as "non-user N"). Non-user N shown in Fig. 9(a) has muscles relaxed during sleep, causing the base of the tongue 2 and soft palate 3 to drop, blocking the airway 4 in the pharynx, causing obstructive sleep apnea.

[0094] Figure 9(b) shows with arrows the state of the pharynx and the airflow during sleep of a patient with obstructive sleep apnea syndrome (hereafter referred to as "user H") who wears the oral mouthpiece 1. In Figure 9(b), the tongue base 2 and soft palate 3 do not drop even when the muscles of user H relax during sleep. This phenomenon is presumably caused by the following mechanism.

[0095] (a) When the oral mouthpiece 1 is worn, the heat-welded portions of the upper jaw mouthpiece part 12 and the lower jaw mouthpiece part 13 are formed so as to be airtight both inside and outside the oral cavity, so that the wearer H can no longer breathe through his / her mouth and must breathe through his / her nose.

[0096] (a) Inhaled air passes through the nasal cavity and reaches the airway 4, which includes the pharynx, and heads toward the lungs. At this time, the air in the oral cavity, which is in a sealed state, is drawn by the flow of inhaled air passing from the nasal cavity through the airway 4 and flows out toward the pharynx. As a result, negative pressure is created in the oral cavity each time air is inhaled.

[0097] (c) When negative pressure is created in the oral cavity, a pulling force (suction force) is generated toward the back as viewed from the pharyngeal side (in other words, toward the front teeth, oral vestibule, and hard palate). This causes the base of the tongue 2 and soft palate 3, which would normally hang down due to muscle relaxation, to be pulled up toward the inside of the oral cavity, thereby securing the airway 4.

[0098] (e) As mentioned above, obstructive sleep apnea is caused by muscle relaxation during sleep, which causes the base of the tongue 2 etc. to block the airway 4. When wearer H wears oral mouthpiece 1, a vacuum effect is created in the mouth, which pulls the base of the tongue 2 etc. toward the inside of the mouth, securing the airway 4 and improving the symptoms of obstructive sleep apnea syndrome.

[0099] Wearing the oral mouthpiece 1 reduces the possibility of side effects such as dry mouth and excessive saliva production seen in sleep splint therapy. Furthermore, because the heat-welded parts of the upper jaw mouthpiece part 12 and the lower jaw mouthpiece part 13 are formed to a thickness of 0 to 2 mm, the wearer's centric occlusion position and mandibular rest position are reproduced when worn, reducing the possibility of side effects such as discomfort in the oral cavity and changes in bite alignment.

[0100] According to the manufacturing method of the oral mouthpiece 1 described above, it is possible to provide an oral mouthpiece 1 in which the vacuum effect generated when the mouthpiece is worn pulls the tongue base 2 etc. toward the inside of the mouth, thereby securing the airway 4 and improving the symptoms of obstructive sleep apnea syndrome.Furthermore, it is possible to obtain an oral mouthpiece 1 with high processing precision without the need for the hands of a skilled dental technician.

[0101] Continuous positive airway pressure therapy, currently the mainstream treatment method, requires the traveler to carry an air supply device with them, which is inconvenient, but the oral mouthpiece 1 is convenient because it can be worn simply by putting it on. Wearing the oral mouthpiece 1 also helps prevent snoring and teeth grinding.

[0102] In addition, since the oral mouthpiece 1 uses the functional EVA sheet S1, the exposed portion T1a of each photocatalytic apatite T exerts the organic matter adsorption and organic matter decomposition functions of the photocatalytic apatite, and efficiently adsorbs and decomposes organic matter. As a result, the oral mouthpiece 1 can be kept clean by drying in the sun (exposing to sunlight) without immersion in a disinfectant, as the attached organic matter can be decomposed by the photocatalytic reaction caused by ultraviolet rays, reducing the effort required for hygiene management. In addition, the decomposition of the attached organic matter by the photocatalytic reaction suppresses coloration caused by the organic matter, and deterioration of the appearance over time can be suppressed.

[0103] Furthermore, the functional EVA sheet S1 does not lose flexibility as a whole sheet, and is easy to process when molding the oral mouthpiece 1, and has a good fit (fit) to the oral cavity (human body) when worn. In addition, in the oral mouthpiece 1, the normal parts T1 of the photocatalytic apatite are embedded in the above-mentioned manner, so that the photocatalytic apatite T is unlikely to fall off from the oral mouthpiece 1, and even if defective parts T2 of the photocatalytic apatite are present, the photocatalytic apatite T can exhibit sufficient organic matter adsorption performance and organic matter decomposition performance in terms of quantity.

[0104] The terms and expressions used in this specification and the claims are merely explanatory and not limiting, and are not intended to exclude terms and expressions equivalent to the features described in this specification and the claims or parts thereof. It goes without saying that various modifications are possible within the scope of the technical idea of ​​the present invention. In addition, when words such as first and second are used, they do not mean rank or importance, but are used to distinguish one element from another element. [Explanation of symbols]

[0105] S1 Functional EVA Sheet S2 EVA S3 Functional EVA sheet after molding T Photocatalytic apatite T1 Photocatalytic apatite normal area T1a exposed part T1b non-exposed part T2 Photocatalytic apatite defective area T2a exposed part T2b non-exposed part 1 Oral mouthpiece 12 Upper jaw mouthpiece parts 13 Lower jaw mouthpiece parts 2 Tongue base 3 soft palate 4. Airway H Recipient N Non-user M1 Upper jaw dental model M2 lower jaw tooth model D Articulator with guide pin G Guide pin

Claims

1. This is an EVA sheet having a plurality of powdered or granular photocatalytic apatite particles having photocatalytic activity dispersed and embedded on at least one side of the front or back surface, and each of the photocatalytic apatite particles is composed of an exposed portion that is exposed to the outside in an embedded state, and a non-exposed portion that is embedded within the sheet in such a manner that it is unlikely to fall off outside the sheet. Functional EVA sheet.

2. The range of the exposed portion is 10% to 60% of the surface of each of the photocatalytic apatites. The functional EVA sheet according to claim 1.

3. For each of the photocatalytic apatites, the range of the exposed portion is less than 10% of the surface of the photocatalytic apatite, and the number of the poorly exposed portions is set to be less than 30% of the total number of the photocatalytic apatite. The functional EVA sheet according to claim 1 or 2.

4. A first step of heating and softening a region of an EVA sheet before processing in which powdery or granular photocatalytic apatite having photocatalytic activity is to be embedded; A second step of substantially uniformly applying an aqueous solution containing a powder or granular photocatalytic apatite to the intended embedding region of the heated EVA sheet that has been subjected to the first step; a third step of drying the aqueous solution applied on the coated surface of the coated EVA sheet formed through the second step; A fourth step of applying a pressing member to the coated surface of the dried EVA sheet formed through the third step while at least the coated surface is still soft, and pressing the photocatalytic apatite with a pressing force sufficient to embed the photocatalytic apatite in the EVA sheet; Equipped A manufacturing method of a functional EVA sheet.

5. The content of the photocatalytic apatite in the aqueous solution is 25% by mass or more and 45% by mass or less. A method for producing the functional EVA sheet according to claim 4.

6. The first to fourth steps are repeated two or three times. A method for producing the functional EVA sheet according to claim 4 or 5.

7. A functional EVA sheet is used in which a plurality of powdery or granular photocatalytic apatite particles having photocatalytic activity are dispersed and embedded on at least one side of the front or back surface, and each of the photocatalytic apatite particles has an exposed portion that is exposed to the outside in an embedded state, and a non-exposed portion that is embedded within the sheet in such a manner that it is difficult for the photocatalytic apatite particles to fall out of the sheet, The dental device includes an upper mouthpiece part and a lower mouthpiece part, which are formed from the functional EVA sheet based on a previously prepared dental model of the upper and lower jaws of a wearer, The upper mouthpiece part and the lower mouthpiece part are arranged so that the wearer can maintain the centric occlusion position, and the part between the left molar and the right molar is continuously heat-welded, and the structure is integrated so that it is airtight in both the inside and outside of the oral cavity. Mouthpiece for the mouth.

Images