Abstract: A shaped article such as a sanitary pottery product is formed through a pressure slip casting process. A mold having a molding cavity defined therein and a slip inlet/outlet hole communicating with the molding cavity is positioned on the support surface of a mold table while the mold table is being maintained horizontally. Then, the mold table is tilted through a first angle with respect to a horizontal plane so that an inner end of the slip inlet/outlet hole is positioned near a lowermost end of the molding cavity in the mold. Thereafter, a slip is introduced under pressure into the molding cavity through the slip inlet/outlet hole. After the clay of the introduced slip is deposited to a desired thickness, the excess slip is discharged from the molding cavity through the slip inlet/outlet hole.

Abstract: A casting mold for sanitary earthenware which has vertically dividable mold units having abutting surfaces with a porous portion of the same quality as a filter medium layer in the mold units and at a region between the porous portion and the exterior of the mold is disposed a sealing member, thereby preventing air leakage and slurry leakage from each mold unit.

Abstract: The invention relates to a process for the production of contoured vehicle internal panelling supports having surfaces smooth on both sides on the basis of wood fibers by depositing an aqueous suspension of wood fiber (pulp) on a preforming screen, drying the preform, pressing and hardening. A deposited layer of fibers is dewatered to a residual water content of 20 to 25% by mass, related to the original quality of suspension, dried in an electric alternating field, then compression molded in a tool without a screen and hardened.

Abstract: In pressing wet concrete between a ram and a mold to compact the concrete and express water from it so as to produce a molded slab, a layer of filter material is provided between the ram or the base of the mold and the concrete and the filter material is secured by a discontinuous coat of adhesive applied as a transfer to the ram and/or to the base of the mold. The adhesive is applied over a sufficient area of the filter material to secure adhesion of the filter material to the ram or base of the mold. The discontinuous adhesive coating is provided as a pattern of particles which covers substantially the entire area of the face of the filter and is present over between 2% and 15% of the total surface area of the filter material.

Abstract: A composite ceramic and metal article having a thermal insulating component formed of single phase magnesium stabilized aluminum titanate and an in situ cast structural component formed of a high melting temperature metallic material. The composite article is particularly useful as exhaust port and manifold structures in internal combustion engines.

Abstract: A concrete form with provision for draining excess water and air from wet concrete by placing fabric over a grid on the support portion of the form. A patterned surface of increased hardness results from use of the form. One embodiment results in concrete with a completely smooth surface.

Abstract: A molding method of ceramic body comprising the following steps of:preparing a ceramic slurry by adding, to ceramic raw material powders, a solvent, organic dispersant and caking agent and mixing them altogether; casting said ceramic slurry into a mold; cooling it to a temperature lower than the melting point of said caking agent; and taking it out of the mold.This molding method is capable of dissolving cracking generation during releasing the ceramic body from a mold, facilitating machining, decreasing the binder amount of organic compounds, diminishing a firing shrinkage and obtaining a higher dimension accuracy.

Abstract: A process for producing a printed circuit board includes steps, sequentially conducted of dispersing in water or organic solvent:(A) 95 to 20% by weight of a styrene polymer having a syndiotactic structure, (B) 5 to 80% by weight of a fibrous filler having a fiber length of 1 to 50 mm, and (C) 0.1 to 30 parts by weight of at least one of a binder and a binding fiber in proportion to 100 parts by weight of the total amount of the components (A) and (B), to make a slurry having a concentration of 0.5 to 100 g/l; separating the solids from the slurry and drying and molding them. Thereafter the solids are either subjected to melting with heating and pressure forming into the molded article, or they are impregnated with a thermoplastic resin which is then cured. Finally, a metal layer is provided on the molded article.

Abstract: Concrete forms utilizing a concrete form liner including a two-sided fabric having a different range of pore sizes on one side compared to the opposite side. In one embodiment, a microporous coating, such as an ethylene-vinyl chloride microfoam dispersion, is placed on one side of a porous fabric to controllably reduce the pore size of the fabric on that side to between 0.2 to 20 microns. The coated fabric is used in combination with a support and a grid to form a concrete casting system wherein the coated side of the fabric is placed directly in contact with the concrete. The microporous coating stabilizes the surface fibers of the fabric thereby reducing the tendency of the fibers to stick to the concrete. The pore size of the coated side of the fabric must be small enough to substantially keep all concrete particles from passing through the fabric, but sufficiently open to permit the passage of water and air.

Abstract: A slip casting device has a molding station for molding a casting with a mold, and a releasing station separate from the molding station, for separating the casting from mold members of the mold which carry the casting. The device may include a pair of vertically spaced molds and a common clamping cylinder interposed between the pair of molds.

Abstract: A method and apparatus for injection molding of ceramic suspension is disclosed wherein an elastomeric bladder is disposed within a mold cavity of a mold. The elastomeric bladder, in a relaxed state, can be tubular or can be formed by bonding together sheets of material. A ceramic suspension is injected into the elastomeric bladder, whereby the elastomeric bladder is distended. Distention of the elastomeric bladder applied a significant force to the ceramic suspension for preventing jetting and formation of knit lines within the ceramic suspension. The ceramic suspension distends the elastomeric bladder until the mold cavity is filled. The ceramic suspension is then exposed to conditions sufficient to cause the injected ceramic suspension to form a molded ceramic greenware composite. The molded ceramic greenware composite can then be removed from the mold for drying and for debindering and densification to form a finished ceramic part.

Abstract: A method for making essentially crack free large cross section ceramic articles by injection molding techniques comprises the use of from about 0.1 v/o to about 10 v/o fibers with the ceramic injection molding formulation followed by the injection molding, binder removal and densification steps to form an essentially crack free densified large cross section ceramic article. The fibers are softened prior to the onset of densification and incorporated into the ceramic intergranular phase. This process eliminates the component distortion during densification which would have occurred if the fibers remained in the component.

Abstract: A process of forming a curved sheet rock panel that can later be used in curved ceiling constructions within buildings. Initially a flat sheet rock panel is soaked with water, and then squeezed to remove excess water. The pliable panel is transferred to an arcuate form, where it quickly remolds itself to the arcuate surface contour on the form. The arcuate panel is dried to a stiff, but still pliable, condition in which it can be fastened to an arcuate ceiling framework.

Abstract: Compositions of matter consisting of matrix materials having silicon carbide dispersed throughout them and methods of making the compositions. A matrix material is an alloy of an intermetallic compound, molybdenum disilicide, and at least one secondary component which is a refractory silicide. The silicon carbide dispersant may be in the form of VLS whiskers, VS whiskers, or submicron powder or a mixture of these forms.

Abstract: A mold, used in pressure casting ceramic articles, includes a plurality of mold parts set and clamped in combination. Each of the mold parts includes: a porous body forming a filter layer with a generally even thickness and a plurality of channels formed in the inside or outside surface thereof and most running in parallel with the molding surface of the mold for allowing water and air to flow therethrough; a reinforcing iron frame for fitting the porous body therein; and a filler filling up the space between the porous body and the iron frame.

Abstract: A process for making a hollow spherical shell of silicate glass composition in which an aqueous suspension of silicate glass particles and an immiscible liquid blowing agent is placed within the hollow spherical cavity of a porous mold. The mold is spun to reduce effective gravity to zero and to center the blowing agent, while being heated so as to vaporize the immiscible liquid and urge the water carrier of the aqueous suspension to migrate into the body of the mold, leaving a green shell compact deposited around the mold cavity. The green shell compact is then removed from the cavity, and is sintered for a time and a temperature sufficient to form a silicate glass shell of substantially homogeneous composition and uniform geometry.

Abstract: A porous polymer plastic material and apparatus containing same useful for making molds, and particularly molds for casting confectionery, pharmaceutical and cosmetic products, and process for preparing molded products.

Abstract: A method and apparatus for making fiber reinforced plastic preforms via a wet slurry process. A screen with the desired preform configuration is placed in the bottom of a tank. The tank is then filled with water and chopped fibers to create a slurry. The screen is raised up through the slurry causing fibers to be deposited on the screen in the shape of the preform. The preform is then removed from the screen, placed in a mold and injected with resin to form the desired structure.

Abstract: A mold for slip casting comprising a compact formed out of a mixture having an organic matter and powders, the organic matter being capable of being extracted by supercritical fluid and the powders being incapable of being extracted by the supercritical fluid, and furthermore, a method for slip casting comprising a compact formed out of an organic matter capable of being extracted by supercritical fluid and having a melting point of 0.degree. to 150.degree. C. The organic matter is any one selected from the group of methyl carbonate, t-butyle alcohol, stearic acid stearyl alcohol and paraffin.

Abstract: A method for casting friable asbestos-containing material into a non-friable mass includes the steps of: (1) mixing portland cement, molding plaster, plasticizer, water and friable asbestos-containing material in a mixer; (2) pouring the mixture into a plastic bag positioned in a form; (3) compressing the mixture within the form prior to the curing process; (4) embedding a lifting eye in the mixture; (5) allowing the mixture to cure to a hardened state; (6) removing the form from the hardened mass; and (7) sealing the upper end of the plastic bag to enclose the hardened mass.

Abstract: A method of producing crack free ceramic parts having large cross-sections is disclosed. An initial mixture of ceramic powder containing a binder and from 0.1 v/o to 10 v/o of whiskers or fibers which are made of carbon, graphite or high temperature melting or decomposition point organic polymers. The mixture is either injection molded or slip cast to form a shaped article. The shaped article is heated in a nitrogen atmosphere to a temperature of 450.degree. C. and then in an atmosphere of air at a temperature of 450.degree. C. to 600.degree. C. to completely remove the binder. The resulting binderless shaped article is then heated at 800.degree. C. for a period of time sufficient to completely remove the whiskers or fibers from the shaped articles. The article is then encapsulated in glass and hot isostatically pressed at a pressure of 30,000 psi to densify the article to approximately 99% of theoretical. The resulting article has a complex geometry and a large cross-section but without detrimental cracks.

Abstract: A composite cartridge-type filter effective to substantially reduce low but hazardous concentrations of lead in drinking water to acceptable levels utilizes a porous activated carbon block filter and a powdered deionizing resin which is converted to an ion exchange resin in situ and during use of the filter. The method of operation of the filter results in a substantially extended life for lead removal as compared to similar disposable cartridge filters. The composite filter is also effective in removing dissolved metals which are leached from the soluble ash fraction of the carbon block itself. Powdered deionizing resin, having a greatly enhanced active surface area as compared to the resin beads from which it is formed, is formed by fracturing the resin beads in situ in a slurry filling and drying process which provides a stable packed resin bed.

Abstract: A method for preparing a ceramic suspension using alpha-Al.sub.2 O.sub.3 powder containing agglomerated powder particles includes dissolving ionic or polymeric reagents as additional dispersing agents in water or an organic solvent as a dispersion medium. Alpha-Al.sub.2 O.sub.3 powder is added thereto while being stirred. Ceramic molded articles may be produced from the suspension.

Abstract: Novel processes have been developed by the present invention for producing hollow ceramic articles. Such ceramic articles are produced by using a water-absorbable mold having water non-permeable faces on an inner surface of the mold at locations corresponding to valve holes. The thickness of a ceramic layer deposited on the inner surface of the mold is controlled by measuring an amount of a lowered liquid surface level of the slurry near a slurry-pouring opening of the mold. Open ends of a hollow ceramic article are formed by cutting corresponding closed ends after deposition of the slurry and firing. A uniform thickness of a slurry deposited onto the inner surface of the mold can be attained by rotating the mold around an arbitrary rotary axis at a rotation speed of 1 to 60 rpm. All ceramic material contained in the slurry fed inside the mold may be deposited on the inner surface of the mold while the mold is being rotated or swung.

Abstract: In a method for effectively producing ceramic manifolds for thermally insulating exhaust channels, an intermediate product is first formed by drain casting which includes a main ceramic pipe having a plurality of branch pipes extending therefrom whose ends are connected together by elongated connection members in the form of thin plates or bars. Thereafter, the intermediate product is fired and the ends of the branch pipes are then cut off together with the connection members. In this manner, even ceramic pipes complicated in shape readily can be produced by preventing strains and deformations which would otherwise occur during firing of the intermediate product.

Abstract: A composition consisting of an intermetallic compound, molybdenum disilicide, which is reinforced with VS silicon carbide whiskers dispersed throughout it and a method of making the reinforced composition. Use of the reinforcing material increases fracture toughness at low temperatures and strength at high temperatures, as compared to pure molybdenum disilicide.

Abstract: A method for casting a metal or ceramic powder which comprises casting a slurry of the metal or ceramic powder suspended in a dispersion medium containing at least 10 wt. % of a liquid extractable with a supercritical fluid or a liquefied gas into a porous mold, keeping the slurry placed in the porous mold at a temperature not lower than the melting point of the dispersion medium, and extracting at least 10 wt. % of the dispersion medium with the supercritical fluid or liquefied gas to impart a formability to the extracted body.In the method of the invention, since the volume change of the dispersion medium due to phase change does not occur, the internal strain and deformation of the molded body occur little. As a result, the sintered body obtained has a highly dimensional accuracy.

Abstract: An inner mold construction and an outer mold construction are provided to define a mold cavity or shape into which wet or uncured concrete is introduced. The method includes the sequential steps of compressing the concrete by movement of the inner mold relatively toward the outer mold to remove surplus liquid from the inner surface of the concrete so that the concrete is at least partially cured. The compression applied on the inner surface of the concrete by the inner mold is maintained while inward pressure is applied over the outer surface of the concrete by the outer mold to remove surplus surface liquid from the outer surface of the concrete. The inner and outer surface pressures on the concrete are released to release the molded article from the mold so that it may be separated therefrom.

Abstract: A process for producing improved gypsum models and molds of high duplication accuracy is provided. In the process, bundles of carbon fibers of specified length and amount having a sizing agent deposited thereon are treated to remove the sizing agent from the carbon fibers which are then separated into single fibers in water. A major part of hemihydrate gypsum (CaSO.sub.4.1/2H.sub.2 O) powder is then added to the carbon fibers dispersed in water to obtain a gypsum slurry having the carbon fibers uniformly dispersed therein. The slurry is then cast to obtain the models or molds.

Abstract: A shaping mole including a container section which is to receive a water-containing ceramic composition and which is defined by a non-permeable mold or a combination of a non-permeable mold and a permeable mold. A part of a shaping surface of the non-permeable mold is made of a material having a contact angle of not less than 80.degree. for water. A process for shaping ceramic articles by using such a mold is also disclosed, which including, the steps of preparing a water-containing ceramic composition comprising a ceramic powder containing a sintering assistant, a shaping assistant, and water, pouring the water-containing ceramic material into the shaping mold, pressing the ceramic composition, and releasing the molding from the mold. The water-containing ceramic material is prepared by using at least a gelatinizable water-soluble binder as the shaping assistant.

Abstract: A superconductor comprised of a polycrystalline metal oxide such as YBa.sub.2 Cu.sub.3 O.sub.7-X (where 0<.times.<0.5) is capable of accommodating very large current densities. By aligning the two-dimensional Cu--O layers which carry the current in the superconducting state in the a- and b-directions, i.e., within the basal plane, a high degree of crystalline axes alignment is provided between adjacent grains permitting the metal oxide material to accommodate high current densities. The orthorhombic crystalline particles have a tendency to lie down on one of the longer sides, i.e., on the a- or b-direction. Aligning the crystals in this orientation is accomplished by mechanical working of the material such as by extrusion, tape casting or slip casting, provided a single crystal powder is used as a starting material, to provide a highly oriented, e.g., approximately 90% of the crystal particles have a common orientation, superconducting matrix capable of supporting large current densities.

Abstract: The invention relates to a process for producing green compacts by the slip-casting process, injection-molding process or extrusion process from sinterable mixtures based on a starting powder mixture containing silicon nitride, and, if appropriate, aluminum nitride and/or alumina and other oxides as sinter aids. The dispersant and binder used is a magnesium chloride hydrate as a mixture with magnesium oxide and water and, after molding, the mixtures are hardened at temperatures from 30.degree. to 60.degree. C. In addition, ceramic fibers, such as silicon carbide, can also be processed as fillers. The green compacts thus produced are sufficiently stable, so that they can be worked mechanically.

Abstract: A process for forming a homogeneous sheet from particulate elements, (as herein defined), at least some of which have an inherent vertical mobility (as herein defined) in water at normal temperature and pressure of from about 1 to about 21 cms/sec, which comprises the steps of forming a foamed dispersion of said particulate elements, and depositing and draining said dispersion on a foraminous support.

Abstract: An apparatus for pressure molding ceramic articles includes at least one split mold including a core mold and an outer mold which are joined together for defining a pressure mold cavity therebetween. At least the bottom surface of the pressure mold cavity is inclined longitudinally and laterally, while the split mold per se is not inclined and the slip supply passage for supplying the slip into the pressure mold cavity communicates with the lowermost end of the pressure mold cavity. Due to the above construction, it is no longer necessary to incline the entirety of the split molds so that the frame structure of the apparatus can be vertically constructed on a horizontal floor which permits easy construction installation and adjustment and maintenance of the apparatus. Furthermore, since the bottom surface of the pressure mold cavity is inclined longitudinally and laterally, the surplus slip is discharged completely and smoothly, and does not remain in the pressure mold cavity.

Abstract: Disclosed is a panel which includes a pan having at least one side member with an upper edge portion, the pan having contained therein a fluid based cementitious material pressed for removal of water while within the pan, and at least one trim member attached to the upper edge portion of the side member of the pan, the trim member undergoing telescoping action upon pressing of the material in the pan so as to be rigidly secured to the upper edge portion of the side member of the pan. Also disclosed is an apparatus and process for production of the pan.

Abstract: A process for making silicon nitride articles of manufacture such as an internal combustion engine valve (2) by providing a homogeneous water-base slurry of silicon nitride powder and at least one nitriding agent and permitting the slurry to age for a time effective to enable a chemical reaction to occur and then reducing the water content sufficiently to form the article and thence forming and nitriding the article using a compound nitriding cycle.

Abstract: The method of molding a ceramic product by forming a mixture of ceramic fibers with lengths less than one-fourth inch, water and a deflouculent, the mixture having a consistency which will not flow, placing the mixture in a water-absorbing mold, vibrating the mold to cause the mixture to flow into contact with the mold and eliminate voids in the mixture, allowing a portion of the water of the mixture to be absorbed by the mold leaving a hardened remnant in the mold, removing the hardened remnant from the mold, and heating the hardened remnant to sinter the fibers therein to each other. In one example, granular alumina is mixed with the mass of fibers, water and the deflouculent to form the mixture.

Abstract: A process for producing a green composite structure by isostatic compression and filtration. A suspension of colloidal size matrix powders is established in a carrier liquid. The suspension is incorporated into a die chamber having a filter opening containing a filter which is permeable to filtrate from the suspension under applied pressure but substantially impermeable to the matrix powders. An elevated pressure is isostatically imposed on the colloidal suspension within the die chamber. The pressure is maintained for a period of time to expel at least 20% of the liquid originally in the colloidal suspension through the filter opening. A specific die chamber comprises a rigid cage structure and an expandable bladder within the cage structure into which the colloidal suspension is introduced. The cage structure is disposed within a pressure vessel which can be initially evacuated to cause the bladder to conform to the cage structure and then pressurized with fluid for the isostatic compression procedure.

Abstract: A power-plant clarifier sludge having the following dry composition:______________________________________ SiO.sub.2 2 to 30 weight percent, Fe.sub.2 O.sub.3 2 to 20 weight percent, Al.sub.2 O.sub.3 0.5 to 5 weight percent, CaO 15 to 50 weight percent, MgO 1 to 8 weight percent, MnO 0.01 to 0.5 weight percent, Na.sub.2 O 0.1 to 0.5 weight percent, K.sub.2 O 0.1 to 1 weight percent, SO.sub.3 in sulfate 0.1 to 2 weight percent, and CO.sub.2 in carbonate 5 to 40 weight percent; ______________________________________is used in the desulfurization of power-plant flue gas and the desulfurization slurry is dewatered and pressed into construction blocks.

Abstract: The elastic modulus and density of an amorphous, ceramic article derived from a resinous organosilicon polymer and having a composition consisting essentially of silicon, nitrogen and/or carbon are increased while substantially maintaining or improving tensile strength by heat treating the ceramic article at an elevated temperature under superatmospheric nitrogen pressure to increase its density while avoiding crystallization. During heat treatment, at least some of the conditions of time, temperature, heating rate, cooling rate, pressure and atmosphere are controlled to minimize erosion of the article which could otherwise occur due to the loss to the surrounding atmosphere, as a gas or gaseous component, of at least one of nitrogen, silicon and carbon. The heat treated, ceramic article is amorphous and non-crystalline and has a density substantially greater than 2.5 g/cc together with desirable values of tensile strength and elastic modulus.

Abstract: A process for preparing reinforced thermoset articles of manufacture from a lofted composite sheet employed as a skeleton or preform which is impregnated with a thermoset resin composition and cured. A reinforced thermoset article of manufacture prepared from a lofted composite impregnated with a thermoset resin composition and cured is also provided.

Abstract: A slip or casting composition useful in molding or sheet casting comprising:a mixture of inorganic particulate material, an organic solvent and a dispersant for said particulate material having the structure set forth below: ##STR1## where R.sub.1, R.sub.2, R.sub.3 are linear or branched hydrocarbon chains, where no more than one of the R Groups is CH.sub.3 and the remaining R groups are each at least 6 to 30 carbon atoms long;Y is selected from the group consisting of (CH.sub.2).sub.n where n=1 to 10 and ##STR2## where m=1 to 5; and X is selected from the group consisting of COO-, SO.sub.3 -, PO.sub.3 -.

Abstract: A casting process for the preparation of whiteware ceramic articles employs a polyalkylene polyamine, such as tetraethylene pentamine, as an additive to increase the casting rate. The additive can be employed, e.g., in slip casting, vacuum casting and pressure casting. Optionally, the addtive includes a binder such as a styrene butadiene latex in an amount effective to maintain the green strength of the articles prepared in the casting process.

Abstract: Ceramic moldings, in particular those having geometrically complicated shapes, are produced by a process in which a ceramic powder is mixed with a molding additive and the mixture is injected into a mold. In order to improve the mechanical properties of the molding, a solution of a high molecular weight polymer in a solvent is used as the molding additive. The mixture is injected at a temperature below the boiling point of the solvent and under from 100 to 1,500 bar into a porous, gas-permeable mold which is at a temperature above the boiling point of the solvent, the injection pressure being maintained until gas no longer escapes from the molding material or the mold.

Abstract: A method of making a water soluble weight, the weight being of the type for attachment to a fishing line, hook or lure by means of a closed loop of thread or string embedded in and extending from the weight, is provided. The weights are formed by filling appropriately shaped cavities in a mold with a mixture consisting essentially of water, soil (preferably a silt-loam mixture or silty clay loam) and sand size stone. The mold rests upon a layer of resilient material (e.g., sponge rubber) which in turn is attached to a rigid layer mounted by resilient means upon a base plate. Openings in the resilient layer overlie recesses in the rigid layer, the openings and recesses being aligned with openings in the bottom of each mold cavity to permit insertion, with the aid of a tool having a notched end, of the thread or string through the mixture in the mold cavity into the underlying recess.

Abstract: In a method for forming a cast article by slip casting through casting of a slip of powders of ceramics, etc. as disporsed in a solvent such as water, etc. into a solvent-absorbable, porous casting mold of gypsum, etc., the casting mold as made is heated to considerably lower the strength of the casting mold in a shape-maintainable range, the slip is cast into the cavity of the casting mold and after solidification of the slip into a green body the casting mold is removed to obtain a defect-free green body. The casting mold can be removed with much ease.

Abstract: A highly loaded, uniform ceramic composite can be made by first preparing a highly loaded suspension. Due to the particle-particle interactions of a highly concentrated system, virtually any dopant can be added, including other suspensions, fibers, and whiskers. The process is particularly useful for making composites of materials which coagulate when mixed at low concentration.

Abstract: A shaped article of fiber reinforced material is made by forming a foamed aqueous dispersion having single discrete fibers, and unconsolidated particulate thermoplastic or thermosetting material, laying down and draining the dispersion to form a web, transferring the web to an oven and heating it to form a self-sustaining permeable sheet, transferring the sheet to a through-air heating oven, passing heated air through the sheet to cause substantially uniform and homogeneous heating of the thermoplastic component, transferring the heated sheet to a compression mold, and subjecting the sheet to compression molding to form a shaped fiber reinforced plastic article.

Abstract: A process is disclosed for reacting the oxides of lanthanum and aluminum.

Abstract: A porous mold for pressure slip casting, which includes: a surface porous layer having an average pore diameter of at most 20 microns and a thickness of 5 to 40 mm; an adhesive applied in a pattern to the rear surface of the surface porous layer to leave an unapplied portion on the rear surface; a coarse porous layer covering the adhesive applied and unapplied portions of the rear surface of the surface porous layer and made of a mixture of a liquid resin and a filler of a particle diameter of 0.1 to 5.0 mm at a volume ratio of 15 to 50:100, the coarse porous layer having a thickness of 5 to 30 mm; a sealing adhesive covering substantially the outer surface of the coarse porous layer; and a passage for water from and air into the coarse porous layer.