JP2006312254A - Anti-staining sheet and anti-staining outdoor waterproof sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-staining sheet having a photocatalyst present therein in a dotted state, low in cost, having good welder processability and capable of also ensuring lightweight properties. <P>SOLUTION: The anti-staining sheet is constituted by integrally providing a resin film at least on one side of a fiber base material, and by providing at least one photocatalyst selected from an apatite coated photocatalyst. A silica coated photocatalyst, both of which are coated with a hydrophilic inorganic compound, is present at least on one side of the resin film. The average primary particle size of the photocatalyst is 1-below 100 nm, and the photocatalyst is adsorbed and fixed on the surface of the resin film in the dotted state to occupy <50% of the surface area of the resin film. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an antifouling sheet and an outdoor waterproof sheet that can be easily welded to form a tent or an edge, have excellent drape, and have been imparted with an antifouling property by a photocatalyst.

  Recently, as an antifouling waterproof sheet, an antifouling treatment using a photocatalyst carried by attaching a hydrophilic film containing a photocatalyst to the surface or carrying a photocatalyst particle by thermocompression bonding on the entire surface of the waterproof film is becoming widespread. As an example of the former, as disclosed in Patent Document 1, a photocatalyst is mixed with a resin that forms a surface film, or as disclosed in Patent Document 2, a photocatalyst is placed on a waterproof film. What is fixed through a binder resin or, as disclosed in Patent Document 3, a resin in which a photocatalyst is kneaded is disposed in a part of the surface layer to reduce the amount of photocatalyst used. Has been tried. As an example of the latter, as disclosed in Patent Document 4, photocatalyst particles are supported on a surface coating by thermocompression bonding.

  The photocatalyst has a function to oxidize organic substances on the surface of the photocatalyst and not only oxidatively decomposes organic dirt but also oxidatively degrades the resin holding or supporting the photocatalyst. Many photocatalyst processed products that cover the photocatalyst and protect the resin by avoiding direct contact with the resin holding or carrying the photocatalyst directly have been proposed. Any of the processed products characterized by antifouling properties using a photocatalyst that protects these resins has a photocatalyst uniformly disposed on the entire surface coating.

  The waterproof sheet whose surface is covered with resin for waterproofing has water leakage or seepage from the seam when it is sewn with thread, and adhesive molding (sewing) by high-frequency fusion (welder) processing that can be easily bonded is desirable The waterproof sheet material is required to have a welder processability, and most of the currently popular waterproofing sheets coated with vinyl chloride are sewn by the welder process. To weld a vinyl chloride-coated waterproof sheet that is coated with a thick resin and is calendered and smoothed, and the resin is infiltrated and exposed to the back. The thickness of the smoothed surface thermoplastic resin is required to be 80 μm or more. That is, when two sheets of vinyl chloride-coated waterproof sheets are overlapped with their surfaces facing up and welded, the minimum amount of resin used for adhesion corresponds to a thickness of 80 μm or more. The same applies to thermoplastic resins other than resins.

In addition, the waterproof sheet needs a function that can be folded and stored, such as a tent or a cover of an automobile, and is strongly desired to be soft and excellent in drape so that it can be easily folded. In addition, the occurrence of creases and cracks in the epidermis when folded is out of the question, and the resin forming the epidermis is desired to be soft and highly weather resistant. However, when particles such as photocatalyst are mixed with the resin, it becomes hard and drapability is lowered, and creases are likely to occur. Also, the mixed particles become an obstacle, leading to a decrease in welder processing. Antifouling waterproof sheets have been slow to spread due to the convenience of processing and use, and because of the high cost of conventional photocatalysts due to the use of large amounts of expensive photocatalysts.
Japanese Patent Laid-Open No. 9-78454 JP 2001-162172 A JP 2003-211569 A Japanese Patent No. 2939524

  The above-mentioned photocatalyst is still expensive for general use and economically inconvenient for adding the photocatalyst to all 80 μm resin necessary for welder processing. Although it is formed of at least two layers, a layer containing a photocatalyst and a layer not containing a photocatalyst, the number of added photocatalysts exposed on the surface of the antifouling waterproof sheet is in any case mixed with resin. Because it is only economical, and it is uneconomical, and the photocatalyst is distributed throughout the layer, oxidation deterioration from the inside of the resin layer also occurs, and there is a risk of peeling of the welder adhesion part, etc. At the time of welder processing, the photocatalyst layer is peeled off to expose a resin layer to which no photocatalyst is added, and these layers are welded and bonded together. The solution to this disadvantage is a waterproof sheet with a method of thermocompression-bonding on the surface of the waterproof sheet that prevents the photocatalyst particles from being soiled. There was a problem that did not go well. In any case, since these contain or carry a large amount of inorganic photocatalyst, there is a problem in that the drapability is also lowered.

  In addition, even if the photocatalyst is fixed to the base material via the binder resin as in Patent Document 2 and Patent Document 3, when used as an outdoor sheet, the photocatalyst is deteriorated when the binder resin is exposed to light. There was a problem that peeled off.

  In order to solve the above-mentioned conventional problems, the present invention is present so that the catalytic function of the photocatalyst can be efficiently exhibited, the cost is low, the welder processability is good, and the antifouling sheet and the antifouling can ensure lightness. Providing outdoor waterproof sheets.

  The antifouling sheet of the present invention is a sheet in which a synthetic resin film is integrated on at least one surface of a fiber base material and has a resin coating, and at least one surface of the resin film is made of a hydrophilic inorganic compound. The coated photocatalyst is present, the average primary particle diameter of the photocatalyst is 1 nm or more and less than 100 nm, and the photocatalyst is adsorbed and fixed to the surface of the synthetic resin film in a dot shape.

  In the present invention, the photocatalyst of fine photocatalyst is adsorbed and fixed in the form of dots on the surface of the synthetic resin film without using a binder resin. In addition, an antifouling sheet can be provided which is good and can secure light weight.

  Further, the antifouling outdoor waterproof sheet of the present invention exhibits the catalytic function of the photocatalyst efficiently, is inexpensive and has good welder processability, and therefore has excellent durability when used outdoors.

  The present inventor has shown that an apatite-based photocatalyst in which the periphery of the photocatalyst is coated with an inorganic apatite is commercially available in order to prevent the photocatalyst from oxidatively degrading the organic matter and the surrounding organic matter. Since this apatite photocatalyst is available, apatite is easy to adsorb, and the photocatalyst coated with fine apatite is white and easy to physically adsorb, this suspension emulsion liquid of this apatite photocatalyst When the film was applied to a synthetic resin film and its adhesion was observed, a film that easily wets water (hydrophilic) can be applied thinly and evenly. Although it became a film of appearance, I learned that the adsorption effect was large and it was not possible to easily remove the applied apatite-coated photocatalyst

  For this reason, the waterproof sheet of the base material used in the present invention is as hydrophilic as possible on at least the surface on which the photocatalyst is applied in order to make it more effective to apply the photocatalyst suspended in water in the form of dots. It is preferable to make it. As the hydrophilization treatment, corona discharge treatment is most preferable from an economic viewpoint, but hydrophilic treatment used for adhesion improvement treatment using an adhesive such as plasma treatment, sulfonation treatment, ozone oxidation treatment or fluorine treatment is also preferably used. Can do. Moreover, the hydrophilic treatment using the chemical | medical agent and coating material which provide hydrophilicity by the anchor process etc. which are used for the adhesive improvement process using an adhesive agent can also be used conveniently. The hydrophilic sustainability of the corona discharge treatment described above is not long. However, when the photocatalyst used in the present invention is attached once, even after 3 months, it shows the same sticking ability by the same solid adsorption as at the beginning. It is better to make it hydrophilic when you do it.

  Further, it is preferable that this film is hot-pressed at a temperature higher than the softening point of the resin constituting the film and close to the melting point, since the adhesion is further strengthened.

  The film was exposed outdoors to observe the function of the photocatalyst. However, the photocatalyst did not easily fall off, and the antifouling effect of the photocatalyst was exhibited.

  Using a suspension emulsion of an apatite-based photocatalyst instead of a flexographic ink engraved with many fine dots, dots were applied to these hydrophilic films to occupy 25% of the surface area. The photocatalyst could be fixed by adsorption without whitening (whiteness) seen at the time. Adhesion due to adsorption was confirmed from the fact that an antifouling effect was exhibited by outdoor exposure.

  Examples of the photocatalyst coated with the hydrophilic inorganic compound used in the present invention include an apatite-coated photocatalyst and a silica-coated photocatalyst. The apatite photocatalyst or silica photocatalyst as used in the present invention refers to a photocatalyst covered with an apatite compound or silica compound. The hydrophilic inorganic compound is preferably a porous inorganic compound. When a silica-based photocatalyst coated with silica more hydrophilic than the apatite was examined, the same good results were obtained. Hereinafter, an apatite photocatalyst will be described for simplification.

  As a result of investigating the traceability, which is another subject matter of the present invention, the resin coating for waterproofing uses a soft resin, and it is preferable that the coating is as thin as possible. The thickness is preferably 80 μm or more.

  In addition, as thermoplastic resins that can be welded using a welder processing machine for vinyl chloride resin, there are polyurethane elastomers and ethylene-vinyl acetate copolymers with good weather resistance that are used in impregnated adhesives for artificial leather. For applications that dislike vinyl chloride resin in response to trends in dechlorinated polymers that require environmentally friendly disposal, the use of this polyurethane elastomer or ethylene-vinyl acetate copolymer is similar to that of vinyl chloride resin-coated waterproof sheets. Welder processing is possible.

  Examples of the fiber base material include polyethylene terephthalate fiber, polypropylene fiber, polyamide fiber, polyaramid fiber, polyvinyl alcohol fiber, acrylic fiber, cellulose fiber such as cotton or rayon, and one or more kinds of fibers selected from glass fiber. A woven fabric, a knitted fabric or a non-woven fabric can be used.

  The synthetic resin film is a heat selected from, for example, a soft vinyl chloride resin containing a plasticizer, an ethylene-vinyl acetate copolymer, a chloroprene rubber, a chlorosulfonated ethylene rubber, or a urethane elastomer resin having a melting point of 140 ° C. or less. A plastic resin is used.

  The synthetic resin film is integrated with at least one surface of the fiber base material to provide a resin coating.

  The average primary particle diameter of the photocatalyst is 1 nm or more and less than 100 nm, and preferably less than 50 nm.

The average area of the dots is preferably less than 0.13 mm ² .

  In order to form the dots, a photocatalyst coated with a hydrophilic inorganic compound, such as an apatite-coated photocatalyst, by a coating method having a number of points such as circles or squares having a fine area by means such as flexo, offset or dot coating And / or a silica-coated photocatalyst is applied, the area occupied by the photocatalyst is less than 50%, and the photocatalyst is fixed to the surface of the synthetic resin film by adsorbing and adhering the hydrophilic inorganic compound to the application surface. -It is supported and can be adhesive-molded by welder processing.

  The woven fabric is preferably made of polyethylene terephthalate fiber, and is a weather-resistant fiber in which a benzotriazole-based ultraviolet absorber is added to the resin constituting the fiber.

  It is preferable that at least the resin coating is formed of a resin having flame retardancy or imparted with flame retardancy, and at least the entire sheet is flame retarded in flame retardancy evaluation from the coating side.

  In addition, soft vinyl chloride resin is used as a synthetic resin film, and one side of a woven fabric made of polyethylene terephthalate fibers is smoothed with a calender roll and subjected to corona discharge treatment to temporarily enhance hydrophilicity. An apatite-coated photocatalyst and / or a silica-coated photocatalyst coated with a hydrophilic inorganic compound suspended in the solution can be applied and dried with a heat calender roll or a dryer.

  A woven fabric composed of polyethylene terephthalate fiber and polypropylene fiber as a woven fabric was impregnated with the soft vinyl chloride resin and the polyurethane elastomer, respectively, and a coating layer of the same resin having a thickness of 90 μm was formed on one surface thereof. On this coating layer, using a flexo coating machine engraved with many fine dots, an apatite-coated anatase-type titanium oxide emulsion suspended in water was applied so that the coating area was 25% of the entire surface, It dried and it was set as the antifouling waterproof sheet. Most of the photocatalyst firmly adheres to the obtained sheet in both the finger and peel test using an adhesive tape. When exposed to exposure outside the room for 3 months, the dirt is removed by rainwater and the antifouling property is obtained. It was confirmed to have

  In applications where photocatalyst fixing is more desirable, it is also possible to improve durability by further applying the calendering of the antifouling waterproof sheet with a heat roll to improve the familiarity between the photocatalyst and the resin film. is there.

  These waterproof sheets have 75% exposed soft resin coating on the welded surface, so when they are welded and welded using a vinyl chloride resin welder machine, sufficient bonding and strong sewing However, it was not exposed to dirt as compared to the waterproof sheet that was not subjected to antifouling treatment, and there was no noticeable difference in draping before and after the antifouling treatment. Thus, the desired welder processing can be easily performed, the drapeability is excellent, and the outdoor waterproof sheet imparted with the antifouling property by the photocatalyst can be obtained.

  Since the antifouling waterproof sheet of the present invention has at least one surface covered with a photocatalyst coated with a hydrophilic inorganic compound adhering to fine dots by adsorption, the surface is used as a surface, as a tent or a hood, and outdoors. Even if it is used in, the antifouling property is remarkably excellent, the dullness due to organic dirt is extremely small, compared to the waterproof sheet colored by the raw material coloring that is entirely covered with the conventional photocatalyst, A sheet having no whiteness and excellent color vividness can be obtained. Furthermore, if a flexo coater, gravure coater or dot coater is used, any pigment can be applied to areas where the photocatalyst is not applied, so it is easy to draw letters and design pictures simultaneously with the photocatalyst application. . Since these are mostly used for viewing from a certain distance rather than close-up, the purpose of display can be sufficiently exhibited. In addition, in order to confirm the application state of the photocatalyst, a dye such as methylene blue having no weather resistance is added to the photocatalyst coating solution, and when applied, the state of the application state can be easily grasped. Is oxidatively decomposed and colorless, and returns to the same state as the product without addition. Using this principle, it is possible to apply dimensional display and shape of a tent, etc. to facilitate sewing and to apply precautions for use to the end user.

  In the present invention, when used outdoors as an antifouling waterproof sheet, the photocatalyst activated by light to become superhydrophilic is fixed to the surface of the sheet by adsorbing a large number of fine dots. When the raindrop comes into contact with the photocatalyst arranged in the dot shape, the raindrop is captured due to its super hydrophilicity. When the number of raindrops is large or large, it is presumed that the adjacent photocatalyst also comes into contact with the entire surface of the sheet, and the entire surface of the sheet is covered with rainwater, thereby cleaning away dirt adhering to the surface of the sheet and developing a cleaning effect. That is, the same cleaning effect is exhibited even when the photocatalyst is not applied to the entire sheet surface.

  In the antifouling sheet of the present invention, at least one surface is covered with a photocatalyst coated with a hydrophilic inorganic compound arranged in fine dots, but the majority of the surface is for waterproofing involved in welder adhesion. Unlike the conventional antifouling waterproof sheet, which is covered with a layer made of photocatalyst like the conventional antifouling waterproof sheet, the resin between the sheets to be bonded is compatible and firmly bonded by welder processing. Since the coating is exposed to the welded surface as much as possible, it can be easily welded as it is.

  The antifouling sheet of the present invention is a urethane elastomer that can be easily flame retardant with a phosphorus-based flame retardant because it is a chlorine-containing thermoplastic resin such as a flame retardant vinyl chloride resin or a polycondensation polymer. Since it is coated, it can be easily made flame retardant and compatible with applications that require flame retardancy.

  In general, an antifouling waterproof sheet using a photocatalyst is used by kneading or mixing the photocatalyst with a thermoplastic resin for waterproofing, and the photocatalyst is expensive, so it is kneaded only in the upper layer which is a part of the waterproof coating. It has been attempted to reduce the amount of photocatalyst used, for example, by placing a resin in which a photocatalyst is kneaded on a part of the surface layer. All of these have taken measures to prevent oxidative degradation of the resin kneaded with the photocatalyst alone or with an inorganic compound, but the resin is used as an adhesive to fix the photocatalyst to the sheet. The photocatalyst was not intended to be held on the sheet by adsorption.

  In the present invention, a photocatalyst covered with fine adsorbing apatite is used, and the photocatalyst is adsorbed and held on a sheet by the apatite adsorbing force. By applying, the absolute area and amount of the photocatalyst are reduced, the whitishness due to the entire photocatalyst application is avoided, and welder processing is possible.

  The present invention uses a coating means such as flexo coating, offset coating or dot coating, performs fine dot coating of the photocatalyst, and exhibits an antifouling action by oxidizing and decomposing dirt adhered to the sheet, Antifouling using a photocatalyst that ensures sufficient surface exposure of a waterproof synthetic resin film for welder adhesion that is not coated with a photocatalyst, which is sufficient for welder adhesion This is a waterproof sheet.

  The present invention relates to a waterproof coating that can be welded, a water-wettable (hydrophilic) thermoplastic resin, a soft vinyl chloride resin containing a plasticizer, an ethylene-vinyl acetate copolymer, chloroprene rubber, chlorosulfone Polyethylene terephthalate fiber, polypropylene, which is generally used as a base fabric for waterproof sheet, which is made of hydrogenated ethylene rubber or urethane elastomer resin having a melting point of 140 ° C. or less and is covered and waterproofed with these resins It is preferable to use a fabric comprising one or more kinds of fibers selected from fiber, polyamide fiber, polyaramid fiber, polyvinyl alcohol fiber, acrylic fiber, cellulose fiber such as cotton or rayon, and glass fiber. Apatite coated with a hydrophilic inorganic compound by the point coating method in which the surface of this water-wettable (hydrophilic) waterproof coating that can be welded has many points such as circles or squares with the above-mentioned fine area. By applying a coated photocatalyst and / or a silica-coated photocatalyst to the entire surface, a tent or the like can be sewn by a welder process, and the antifouling outdoor waterproof sheet retains antifouling properties.

  In addition, the photocatalyst coated with the hydrophilic inorganic compound to be applied is, for example, an aqueous suspension emulsion liquid mainly composed of water, and in this case, if the surface to be applied is not in a state that is easy to be familiar with water, Since smooth application is not possible due to the problem of repellency, the hydrophilicity of the application surface is important. The thermoplastic resin forming the sheet surface described above is at least not water-repellent and can be applied as it is, but in order to clarify the coating pattern, it is more preferable to make the sheet surface more hydrophilic. This hydrophilization means is most preferably a corona discharge treatment from an economic point of view, but a hydrophilization treatment used for adhesion improvement treatment using an adhesive such as plasma treatment, sulfonation treatment, ozone oxidation treatment or fluorine treatment can be preferably used. . Moreover, the hydrophilic treatment using the chemical | medical agent and coating material which provide hydrophilicity by the anchor process etc. which are used for the adhesive improvement process using an adhesive agent can also be used conveniently. It is also preferable to fix the photocatalyst by taking measures to enhance smoothness and hydrophilicity, such as coating the photocatalyst coating surface very thinly with an acrylic resin.

  In the description of the present invention, as described above, the discussion proceeds with the aqueous suspension of the photocatalyst. However, for the demand for quick drying in production, the combined use of an organic solvent soluble in water such as alcohol or acetone is also preferable. .

  In applying the photocatalyst, at least the surface of the sheet is hydrophilic during application, and at least the hydrophilic inorganic compound encapsulating the photocatalyst is adsorbed and fixed to the hydrophilic sheet surface. That is, the photocatalyst adheres to the surface of the synthetic resin film by adsorption through the hydrophilic inorganic compound. In other words, the photocatalyst is fixed and supported on the surface of the application surface.

  Adhesion by this adsorption is firmly fixed as described above, the adsorption effect is large, and it is easy to easily remove the photocatalyst (apatite-coated photocatalyst) coated with the coated hydrophilic inorganic compound. Can do.

  In the present invention, as described above, the photocatalyst is applied to the sheet surface with dot-like dots, but since it is also intended to adopt a sewing method in which welding is performed and bonded, the synthetic exposed on the surface It is desirable that the ratio of the resin film to the sheet surface (application surface) exceeds 50%, and more preferably exceeds 60%. On the contrary, it is particularly preferable that the total area of the photocatalyst spot coating is 40% or less of the coated surface. When the area occupied by the photocatalyst on the sheet surface is 50% or more, an unbonded portion is generated, and welder bonding cannot be performed completely, leading to the occurrence of water leakage from the sheet, which is not preferable. Conversely, the area occupied by the photocatalyst on the sheet surface is preferably less than 50%.

In the present invention, as described above, the photocatalyst is applied to the sheet surface with dot-like dots to exhibit the antifouling effect due to the oxidation effect of the photocatalyst, but the surface coating ratio is a dot-like per unit area. The coverage ratio can be reduced as the number of dots increases. When the area occupied by the photocatalyst on the sheet surface is less than 50%, in order to increase the number of dots, the area per dot-like dot is set to less than 0.13 mm ² to provide a sufficient antifouling effect. Can be. Although depending on the smoothness of the sheet, when the dot-like dots are regularly arranged at regular intervals, a sufficient antifouling effect is exhibited if the coating ratio of the photocatalyst to the sheet surface is 10% or more. More preferably, when the coating ratio is 20 to 40%, the antifouling effect and the welder processability are excellent. Of course, even if the area per dot-like dot exceeds 0.13 mm ² , the antifouling sheet of the present invention can be obtained, but in order to increase the number of dot-like dots, the surface coating with a photocatalyst is possible. Since it is necessary to make the ratio as close to 50% as possible, the amount of photocatalyst used is also increased, which is economically disadvantageous.

Further, it is preferable from the viewpoint of the antifouling effect to reduce the area per dot-like dot to increase the number of dot-like dots, but it is necessary to make the engraving of the coating jig more precise, Considering the wear resistance of the coating jig, it is not economically preferable to reduce the area unnecessarily. The area per dot-like dot is usually 0.06 to 0.12 mm ^{2 and} can be conveniently used.

  The use amount of the photocatalyst of the present invention is 50% compared to the method of applying the entire surface to the surface even if the coating ratio of the sheet surface is 50%, compared with the conventional resin impregnation method generally used. The amount used is 5% or less, and even if the cost for coating is somewhat increased, the economic effect is great in achieving the same antifouling effect.

  As the photocatalyst used in the present invention, known photocatalysts such as anatase-type titanium oxide are conveniently used, and these photocatalysts are coated with a hydrophilic inorganic compound for the purpose of reducing deterioration of the surrounding resin. This coated photocatalyst is used. Anatase type titanium oxide may be doped with any element such as antimony.

  In addition, as the photocatalyst used in the present invention, a commercially available ultrafine powder is used, but those having an average primary particle diameter of less than 100 nm are also commercially available. A photocatalyst having a primary particle size of less than 100 nm is used. The preferable average primary particle diameter of the photocatalyst is 80 nm or less, and more preferably 50 nm or less. It is preferable to avoid secondary agglomeration of the fine powder as much as possible, and the number of secondary agglomerated particles when agglomerated is small and the diameter is preferably less than 1 μm. More preferably, the average secondary particle diameter is 500 nm or less, and the smaller the surface area, the larger the surface area and the better the adsorbing power and the higher the adhering power.

  Furthermore, the substance covering the photocatalyst used in the present invention is preferably a hydrophilic inorganic compound. Examples of hydrophilic inorganic compounds include apatite and silica, and it is known that these fine powders are very easy to adsorb gas and the like. The present inventors have confirmed that the coated apatite-coated photocatalyst or silica-coated photocatalyst has a high adsorbability like a single compound, and conversely, a phenomenon that the adsorbed and fixed to the hydrophilic polymer itself. In addition, the adsorption phenomenon is larger as the surface area is larger for the same adsorbent, and the surface area per unit mass is larger as the particle size is smaller in the powder, that is, the smaller the adsorbent is, the more hydrophilic polymer is. It will be easy to adsorb. For this reason, the particle diameter of the photocatalyst used in the present invention is determined.

  The base fabric used as the base material of the antifouling sheet of the present invention is a factor responsible for physical properties such as strength. For example, the 2000 Ministry of Construction announcement specifying a building with a simple structure such as a tent warehouse Fabrics made of glass fiber, polyamide fiber, polyaramid fiber, polyester fiber and polypinyl alcohol fiber described in the document No. 1443 are conveniently used, and in addition, polypropylene fiber, acrylic fiber, cotton fiber or cellulose fiber such as rayon. The resulting fabric is equally convenient. In addition, these fibers are preferably yarns such as spun yarn, multifilament fiber, and core yarn because they are easy to weave. In addition, when the fiber is a split type composite fiber, it is preferable to use a woven fabric of these yarns including a superfine fiber that has been split and processed by high-pressure hydroentanglement because the drape can be improved.

When the antifouling sheet of the present invention is used as an outdoor waterproof sheet for building applications such as a tent warehouse, the thickness of the sheet is 0.5 mm to 0.7 mm, and the basis weight is 600 to 900 g / m ² . Yes, the tensile strength is 400 to 900 cN / cm, and the water resistance is preferably 2000 mmH ₂ O. The sheet for the waterproof cover is 400 to 700 g / m ² with a reduced basis weight, but there is no inconvenience other than this depending on the application.

  As the thermoplastic resin for waterproofing the woven fabric, in addition to the vinyl chloride resin, chloroprene rubber and chlorosulfonated ethylene rubber of the notice, a soft vinyl chloride resin containing a plasticizer, an ethylene-vinyl acetate copolymer, or A urethane elastomer resin having a melting point of 140 ° C. or lower can also be used conveniently. The former is mainly an outdoor tarpaulin for buildings such as tent warehouses, and the latter is an outdoor tarpaulin for waterproof covers such as a truck tarpaulin requiring drape.

  The resin for forming the surface to which the photocatalyst used for the antifouling outdoor waterproof sheet of the present invention is applied is not a special welder processing machine, but is widely used for bonding a waterproof sheet formed with a film with a current vinyl chloride resin. It is most preferable that it can be processed by a welder processing machine. However, as described above, it is limited to a soft vinyl chloride resin containing a plasticizer or a urethane elastomer resin having a melting point of 140 ° C. or lower, but other non-water-repellent thermoplastics that can be welded. There is no problem even if it is resin. However, from the viewpoint of welder processing, a resin having a melting point of 140 ° C. or lower is more preferable. In addition, the resin material is limited in the present invention because the majority of the applications that require weather resistance as the material occupy a track record of weather resistance, for example, by applying a photocatalyst to currently available waterproof sheets. This is because an antifouling waterproof sheet is also considered. The reason why the melting point of the urethane elastomer resin is set to 140 ° C. or less is due to the restriction of the workability of a commonly used vinyl chloride resin welder processing machine, and there is no limitation if a special welder processing machine is prepared. Needless to say, the thermoplastic resin having a melting point that is at least 20 ° C. lower than the fibers forming the base fabric is preferable for processing.

  As for the antifouling outdoor waterproof sheet of the present invention, a resin coating on one side is sufficient for the purpose of finishing products by sewing instead of welder processing with emphasis on weight reduction and drapeability of automobile covers and tents, When welder processing such as a tent warehouse is an indispensable requirement, the resin forming the coating penetrates into the woven fabric, and the resin is exposed on the other side. is important. That is, the thickness of the coating film (synthetic resin film) forming the surface on which the photocatalyst is applied in the waterproof sheet of the present invention is such that the resin forming the coating penetrates into the inside of the fabric and the resin is exposed on the other surface. In the case of this state, it is at least 50 μm, more preferably 80 μm. In the case where the resin is not exposed to the other surface, it is important to make it thicker when the resin-coated surfaces are not bonded to each other. The latter case occurs when weight reduction is intended, and basically, adhesive molding is performed by bonding the resin coated surfaces.

  In addition, for the convenience of sewing them with a welder process, the melting point exceeds 100 ° C. and is preferably 140 ° C. or less. Even if the melting point is high, the plasticizer is added and the apparent melting point (softening point) is 140 ° C. or less. ). In particular, the upper limit of the temperature for urethane elastomer resin is that sewing with a welder processing machine used for the vinyl chloride resin most widely used in Japan is possible. The reason why the temperature of other resins is not limited is that resin types that can be welded are known.

  Furthermore, in the present invention, the resin impregnated and the resin forming the skin may be different for the convenience of processing molding and quality assurance, and the amount of plasticizer added and the softening temperature are different even for the same type. There is no problem with different types.

  The antifouling outdoor waterproof sheet according to the present invention is not weather-resistant and contains no inorganic substance other than the photocatalyst. When the base fabric is made of polyethylene terephthalate fiber, an ultraviolet absorber is added to the fiber to provide weather resistance. It is important to enhance the property, and it is preferable to use a benzotriazole-based ultraviolet absorber as a drug. Even when other base fabrics are used, it is desirable to add a weathering agent.

  If there is a demand to color the antifouling sheet of the present invention, the coating resin is kneaded with an inorganic pigment for coloring or an organic pigment or dye having good weather resistance to form a raw material-colored sheet or no photocatalyst is applied. It is also preferable to color the portion by applying a point colored with an inorganic pigment for coloring or an organic pigment or dye having good weather resistance. In the latter case, it is easy to apply a character or a picture in the same manner to obtain a design sheet.

  In addition, the antifouling sheet of the present invention is almost colorless and transparent even when a photocatalyst is applied, so it is difficult to distinguish it from those that are not applied, and it is colored by adding an organic dye with poor light resistance to the photocatalyst solution. It is also possible to make it easy to discriminate. In addition, it is also preferable to apply construction notes with this solution, and these sheets are discolored and become uncolored after several weeks of use due to the action of the photocatalyst.

  Unlike the conventional antifouling sheet, the antifouling sheet of the present invention is not coated with a binder resin at all on the surface of the photocatalyst, so that it can exhibit an antifouling effect from the beginning, but the excess applied excessively. In order to prevent the photocatalyst from dropping and the photocatalyst from adhering to other objects, water is applied or sprayed on the photocatalyst application surface in advance, and then the photocatalyst is activated by irradiating the photocatalyst with ultraviolet light. It is also possible to make it possible to exhibit the antifouling effect without dropping off the photocatalyst immediately after use.

  In the antifouling treatment method using the photocatalyst of the present invention, at least one surface is coated with a coating of a synthetic resin film capable of being welded on the surface of a sheet, and apatite type or A photocatalyst covered with a silica-based compound is applied, so that the total application area is less than 50% of the entire application surface, that is, the portion not covered with the photocatalyst covered with a hydrophilic inorganic compound is 50% or more. It was made to be. At least a synthetic resin film exposed in a portion not covered with the photocatalyst is used for an adhesive molding process by a welder process so that the welder process can be performed satisfactorily.

Next, the present invention will be specifically described with reference to examples and comparative examples. In the following description, the apatite-coated photocatalyst will be described, but the silica-coated photocatalyst is also the same, and the photocatalyst coated with another hydrophilic inorganic compound will not be described, but it can be easily used with reference to the following description. I can do it. Moreover, although it demonstrates mainly with a polyethylene terephthalate fiber fabric, another fabric can be implemented similarly.
[Photocatalyst to be used]
A specific example of the photocatalyst covered with the apatite compound used in the present invention is commercially available under the trade name “Jupiter” manufactured by Showa Denko KK, and its average primary particle size is about 30 nm and aggregated. The average secondary particle diameter is 200 to 500 nm. The photocatalyst is applied using a solution in which the photocatalyst is uniformly dispersed in a solvent. The average particle diameter can be measured by a microscope method or a light scattering method.

  To uniformly disperse this photocatalyst, for example, in water, a very small amount of dispersion thickener or penetrant, and in some cases alcohols, are added to prevent sedimentation of the particles, improving the stability of the aqueous suspension and It is convenient to use it as a coating solution that is substantially free of binder resin and has been improved in coating suitability.

  The photocatalyst to be used is fine, and when it is applied in a dot shape with a fine area and placed on the film, it is adsorbed and fixed on the surface of the film.

  In addition, the photocatalyst used for this invention can be similarly used by covering not only anatase type titanium oxide but a generally well-known photocatalyst with an apatite type or a silica type compound.

  The size of the photocatalyst covered with the apatite-based or silica-based compound used in the present invention is preferably less than 1 μm because the photocatalyst is mainly adsorbed and fixed, and a photocatalyst coating solution designed to prevent secondary aggregation as much as possible Is preferred. Furthermore, the size of the primary particles of the photocatalyst is preferably as fine as possible with an average particle diameter of 100 nm and further 50 nm or less.

  For the reasons described above, the photocatalyst manufactured by Showa Denko Co., Ltd. will be described in the following examples. However, as a photocatalyst, a silica-based photocatalyst coated with hydrophilic silica as well as apatite is also an apatite-based photocatalyst. It was the same.

The coating solution used in the examples of the present invention is water containing 20% by mass of apatite-based photocatalyst fine particles coated with an apatite compound manufactured by Showa Denko KK having the above particle size and 0.5% by mass of a penetrant for dispersing the particles. The dispersion is mixed with 0.4% by mass of a dispersion thickener for making it difficult to settle and separate the dispersed photocatalyst fine particles during storage. An aqueous dispersion having a viscosity of several hundred (about 300) centipoise is mixed. Using. Viscosity can be set arbitrarily by changing the amount of dispersion thickener added, and is adapted to the flexo applicator.
[Base fabric of waterproof sheet used]
A staple fiber made of polyethylene terephthalate (PET) resin with a fineness of 7 dtex was spun and a 10th single yarn (indicated as 10 s / 1) was used, with 46 warps / inch (indicated as weaving density 46), 43 wefts / inch. A PET woven fabric A having a basis weight of 230 g / m ² (designated as woven density 43) was used.

Similarly, weaving density (49 length / inch, width 46 / inch) basis weight of 250 g / weight with double yarn (indicated as 20 s / 2) of 20th PET spun yarn as warp and weft as (10 s / 1) It was set as m ² PET fabric B.

A PET fiber made of 2 dtex polypropylene (PP) resin is spun into a 10 s / 1 spun yarn, and a woven density (length 46 / inch, width 43 / inch) PP woven fabric C with a basis weight of 230 g / m ² It was.

Similarly, a No. 10 cotton thread was used to form a woven fabric D having a weaving density (length 49 / inch, width 46 / inch) and a basis weight of 250 g / m ² .

A PET fabric E having a total fineness of 5.5 dtex and a multi-twisted PET multifilament having 72 filaments and having a weaving density (length 14 / inch, width 14 / inch) and a basis weight of 155 g / m ² did.

A glass fiber plain fabric having a basis weight of 365 g / m ² and made of glass fiber having a diameter of 3 μm was designated as glass fabric F.
[Waterproof sheet to be used]
The woven fabric A, the woven fabric C, and the woven fabric D are made of a paste vinyl chloride resin to which the following plasticizers and additives are added, and an organosol 1 using toluene as a solvent. Inject uniformly, pull it up and squeeze with mangle roller, impregnate and adhere at least one side uniformly with vinyl chloride resin, dry and heat-treat with hot air dryer at 150 ° C and 175 ° C for 1 minute respectively, Again, dip the other side into the organosol 1 bath and uniformly inject the organosol 1 from the other side. Pull it up and squeeze it with a mangle roller so that at least the other side is uniformly impregnated with vinyl chloride resin. In the same manner as before, the sample was dried and heat-treated for 1 minute each with a hot air dryer at 150 ° C. and 175 ° C., and then at least with a hot roll at 180 ° C. To smooth the surface of the face, thickness impregnation amount of the vinyl chloride resin in 310 g / m ² was about 0.5mm sheet A1, sheets C1 and sheet D1.

The fabric B and fabric A are less impregnated with vinyl chloride resin in the first organosol 1 bath, the second impregnation is increased to the same amount of impregnation as the sheet A1, and this surface is smoothed with a hot roll, The impregnation amount of the vinyl chloride resin was 300 g / m ² , the fabric B was a sheet B1 having a thickness of about 0.6 mm, and the fabric A was a sheet A3 having a thickness of about 0.5 mm.

Sheet A1, sheet C1, and sheet D1 were impregnated on one side, dried and heat-treated, and immediately smoothed on one side with a hot roll at 180 ° C., the impregnation amount of vinyl chloride resin was 155 g / m ² and the thickness was about The sheet A2, the sheet C2, and the sheet D2 were 0.5 mm, respectively.

  Similarly to the sheet A1, a PET woven fabric E and a glass woven fabric F were impregnated and adhered from both sides with a vinyl chloride resin to obtain a sheet E1 and a sheet F1 having a thickness of about 0.5 mm, respectively.

In addition, an acrylic resin (using a product name “Sony Bond SC-474” having a solid content of 30% by mass) with a basis weight of 12 g / m ² is applied on one side of the sheet A1 with a roll coater to prevent additive volatilization, and 100 It dried with the hot-air dryer of ° C, and it was set as sheet A4 with an additive volatilization prevention layer.
[Paste vinyl chloride resin with added plasticizer and additives]
Paste vinyl chloride resin (P-1600) 100 parts by mass Plasticizer (adipic acid polyester and DINP, etc.) 65 parts by mass Other modified soybean oil, mildew-proofing agent, coloring material, stabilizer, curing agent, etc. 16 parts by mass Solvent (toluene) ) 20 parts by mass [Examples 1 to 5, Comparative Example 1]
Using a flexo machine on the surface smoothed by the hot rolls of sheet A1, sheet C1, sheet D1, sheet E1 and sheet F1, one dot-like dot with the above-mentioned aqueous coating solution of apatite-coated photocatalyst manufactured by Showa Denko KK The antifouling property of the present invention (10 g / m ^{2 was} applied so that the applied area occupies 40% of the total target area with an area of 0.1 mm ² and adhered as shown in FIG. Waterproof sheet. At first glance, it cannot be determined that the photocatalyst is applied, but it can be determined by comparing the surface illumination with the reflected light viewed obliquely. When the sheet A1 not coated with the photocatalyst was exposed to sunlight outdoors in the summer for three months, the sheet A1 of the comparative example was noticeably soiled. However, there was no rain streak from the first rainfall and there was no change from the beginning of exposure.

Although these were tried to be bonded with a welder processing machine for vinyl chloride resin, the photocatalyst-coated surfaces were firmly bonded to each other, and there was no problem at all for use as a tent.
[Examples 6 to 7]
Using a flexo coater on the surface smoothed by the hot rolls of the sheet B1 and the sheet A3, the area per dot-like dot is set to 0.1 mm ² with the above-described aqueous coating solution of apatite compound manufactured by Showa Denko K.K. 6 g / m ^{2 was} applied so that the applied area occupies 25% of the total target area to obtain an antifouling (waterproof) sheet of the present invention. These antifouling properties and welder workability were the same as those of the sheet A1 of Example 1, and both were good.
[Example 8]
On the acrylic resin layer of the sheet A4 with the additive volatilization preventing layer, a photocatalyst was applied in the same manner as the sheet A1 of Example 1 to obtain an antifouling (waterproof) sheet of the present invention. The antifouling property and welder workability were the same as the sheet A1 of Example 1, and the photocatalyst was adsorbed and both were good.
[Examples 9 to 11]
The photocatalyst was applied to the surfaces of the sheets A2, C2 and D2 impregnated with the vinyl chloride resin in the same manner as the sheet A1 of Example 1 to obtain an antifouling (waterproof) sheet of the present invention. This antifouling property was the same as that of the sheet A1 of Example 1, and the photocatalyst was adsorbed, and both were good. In addition, the welder processability was good when the surfaces impregnated with the vinyl chloride resin were put together to be the same as the sheet A1 of Example 1.
[Example 12]
In the sheets A1 and A4, the surface smoothed with a hot roll was subjected to corona discharge machining, and then a photocatalyst was applied in the same manner as the sheet A1 in Example 1 to obtain an antifouling (waterproof) sheet of the present invention. The coating property of the photocatalyst was improved, and the coating of the photocatalyst became clearer when viewed with an electron microscope. The antifouling property and welder workability were the same as the sheet A1 of Example 1, and both were good.
[Example 13]
A sheet of A1 on which one side of the sheet A1 is mixed with 8% by mass of aluminum powder and added with the following plasticizer and additives is passed through a 170 ° C. calender roll and rolled into a 0.2 mm film. The film was bonded by thermocompression bonding with a roll, and a photocatalyst was applied thereon in the same manner as the sheet A1 of Example 1 to obtain a heat reflection type antifouling (waterproof) sheet of the present invention. The antifouling property and welder workability were the same as the sheet A1 of Example 1, and the photocatalyst was adsorbed and both were good.
[Vinyl chloride resin with plasticizer and additives]
Paste vinyl chloride resin (P-1000) 100 parts by mass Plasticizer (adipate polyester and polymer plasticizer, etc.) 90 parts by mass Other modified soybean oil, mildew-proofing agent, colorant, stabilizer, curing agent, etc. 20 parts by mass Light reflecting material (aluminum powder) 8 parts by mass [Example 14]
In Example 1, a photocatalyst was applied in the same manner as in Example 1 using a gravure coater instead of a flexo coater. Although the coating was slightly disturbed, the antifouling property and welder workability were the same as the sheet A1 of Example 1, and the photocatalyst was adsorbed, and both were good.
[Comparative Example 2]
A photocatalyst coated with apatite, which was obtained several years ago, with a particle size of more than 1 μm and using 2 to 3 μm, it was hand-painted on one side of sheet A1, but when it dries it peels off and adheres to the sheet It was bad.

It is an example which shows the application shape of the photocatalyst in this invention (a circular part is a dot-like photocatalyst).

Claims (11)

A sheet comprising a resin film integrated with a resin film on at least one surface of a fiber substrate,
A photocatalyst coated with a hydrophilic inorganic compound is present on at least one surface of the resin film, and the average primary particle diameter of the photocatalyst is 1 nm or more and less than 100 nm, and the photocatalyst is adsorbed on the surface of the synthetic resin film in the form of dots. An antifouling sheet characterized by being fixed.   The antifouling sheet according to claim 1, wherein the average primary particle size of the photocatalyst is less than 50 nm. The antifouling sheet according to claim 1, wherein an average area of the dots is less than 0.13 mm ² .   The antifouling sheet according to claim 1 or 2, wherein an area occupied by the photocatalyst is less than 50%.   2. The antifouling sheet according to claim 1, wherein the synthetic resin film penetrates into the fiber base material and the resin is exposed on the other side.   The antifouling sheet according to claim 1 or 5, wherein the synthetic resin film is colored by including an inorganic pigment, a weather-resistant organic pigment or a dye for coloring.   The antifouling sheet according to claim 1, 2 or 4, wherein a portion other than the photocatalyst is colored with an inorganic pigment, a weatherable organic pigment or a dye for coloring.   The antifouling sheet according to claim 1, wherein the photocatalyst-coated surface of the synthetic resin film is hydrophilized.   The antifouling sheet according to claim 1, wherein the photocatalyst coated with a hydrophilic inorganic compound is at least one photocatalyst selected from an apatite-coated photocatalyst and a silica-coated photocatalyst.   The antifouling outdoor waterproof sheet, wherein the resin film in the antifouling sheet according to claim 1 is a waterproof film.   The antifouling outdoor waterproof sheet according to claim 10, wherein the waterproof sheet can be bonded by welding.

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