WO2002026661A1

WO2002026661A1 - Decorated enamel sheet, production method and the use of said sheet in the ceramic industry

Info

Publication number: WO2002026661A1
Application number: PCT/ES2001/000328
Authority: WO
Inventors: Francisco Sanmiguel Roche; Carlos Concepcion Heydorn; Vicente Ferrando Catala; Juan Vicente Corts Ripoll
Original assignee: Torrecid S.A.
Priority date: 2000-09-28
Filing date: 2001-08-23
Publication date: 2002-04-04
Also published as: AU2001285953A1; CN1392872A; ES2169685B1; BR0107286A; JP2004509832A; ES2169685A1

Abstract

The invention relates to a new material that makes it possible to encompass any type of surface finishing and that is characterized in that it provides both the base enamel and the decoration for the decoration of ceramic products. The composition of the sheet comprises mixtures of frits and natural and/or synthetic raw materials, the size of the particles being controlled, in addition to the additives required to obtain appropriate forming of the sheet. The invention also relates to the production method of the sheet. The inventive sheets are used to decorate and/or enamel ceramic objects that undergo temperatures ranging between 1,000-1,250 °C during production.

Description

Title

Decorated enamel sheet, manufacturing method and its use in the ceramic industry.

BACKGROUND OF THE INVENTION The present invention refers to a new material that can be used in the ceramic industry to proceed with the decoration and / or enamelling of different ceramic products.

The manufacture of refractory ceramic powder sheets (oxides, carbides, nitrides, borides, and sulphides of lithium, potassium, beryllium, magnesium, boron, aluminum, silicon, copper, calcium, strontium, barium, zinc, cadmium, gallium is widely known. , indium, titanium, zirconium, bismuth or manganese) by the ribbon cocking process, the patents and articles being numerous in which reference is made to the characteristics, compositions and method of preparation thereof. Patent No. US405412 describes in detail the method of preparing sheets of alumina organic base in Patent No. US4480045 said process becomes waterborne, whereas in Patent No. ^s US5473008 and US5057360 are They indicate different compositions both in reference to the additives used and the incorporation of other ceramic refractory powders other than alumina. All these types of sheets are normally used in the electronics industry to obtain plates for manufacturing integrated circuits, etc. using temperatures in the sintering process of the sheets above 1300 ° C. In no case are these types of sheets suitable for decorating and / or enamelling traditional ceramic products (tiles, dishes, etc.) in which the cooking temperatures range between 1000 ° C and 1250 ° C. The aforementioned ceramic refractory powder sheets also have the disadvantage of their coefficient of thermal expansion, which is very different from that of traditional ceramic products, and also that in certain cases they cannot be sintered in oxidizing atmospheres, so if they will try

SUBSTITUTE SHEET (RULE 26) using such sheets of refractory ceramic powders in the traditional ceramic industry would generate multiple defects, mainly cracking, occluded bubbles, blackening, etc. in the final product, which would make its commercialization unfeasible. On the other hand it is also known to use decals (decorated sheets) to decorate very different types of ceramic materials (tiles, dishes, etc.). There are innumerable patents that refer to this type of sheets, but all are based on decorating, by different well-known methods, a plastic sheet, which can have very different compositions. The decorated plastic sheet (decal) is applied on the object to be decorated by thermo-transfer, wetted with water, etc., and once the decoration has been transferred to the object in question, it is necessary to remove the plastic sheet, already without the decoration. Therefore this type of sheets are only valid for decorating on the surface of objects and not in interior areas (for example in sandwich). They also have the disadvantage that it is only possible to provide the decoration, the incorporation of enamels to proceed with the enamelling of the ceramic object and being able to confer different surface finishes is not feasible.

Another type of sheet product is that described in Patent No. IT040151. It is a sheet of paper on which, in certain areas as a mosaic, colored ceramic material has been deposited by silkscreen printing, which is the reason for decoration. It is used to decorate tiles and is applied in the press in the process of forming the tile, having to remove the excess paper on which the colored ceramic material had been deposited once the forming stage was finished. The colored ceramic material is of the same nature as that used to form the thickness of the tile, being basically constituted by different clays. Therefore this type of sheet has the disadvantages that it is only

SUBSTITUTE SHEET (RULE 26) possible its application in the press, enamels that allow to extend the type of surface finishes cannot be incorporated and in no case it will be possible to cover the entire surface of the tile since the colored ceramic material is only applied in certain areas of the tile surface as a Mosaic Finally, there is also evidence of the existence in the market of a product marketed by the firm Dedra that consists of a sheet composed in its 70% by a. organic material and the remaining 30% by granules whose particle size is always above 150 μm. The decoration in question is applied to the sheet by screen printing, roller or other known technique. This type of sheets are used to decorate steps or objects with irregular geometry and is applied on the object already formed, adapting the sheet to said object by means of silicone rollers and applying heat so that it is adhered. This type of sheets have the disadvantage that they must be applied on the ceramic object already formed and it is not possible to incorporate particles lower than 150 μm in its composition, which completely restricts the field of application and the aesthetic effects that can be achieved .

On the contrary, decorated enamel sheets, object of the present invention come to solve all the problems raised above. It is possible to incorporate in its composition particles of very different nature (from frits to natural and synthetic raw materials) and particle size, even below 1 μm. It is also possible to modify their thickness at will, ranging from values close to 50 μm to 3000 μm. These characteristics allow covering any type of surface finish, adapting the characteristic parameters commonly used in traditional ceramics (expansion coefficient, melt viscosity, transition temperature, etc.) to the needs of each specific case and adjusting the working temperature to any value within the 1000 interval

SUBSTITUTE SHEET (RULE 26) - 1250 ° C mentioned above. On the other hand they are perfectly manageable and transportable sheets, even in the form of a roll, being able to apply them by very different methods both on already formed objects and during the process of forming the object in question, also allowing it to be applied in sandwich. All this, in short, allows these sheets to be used not only as an element that provides decoration, as is the case of most of the sheets mentioned in the state of the art, but as an element that jointly provides the base enamel and the decoration, which supposes an important novelty with respect to the existing plates until the moment. By way of example, and without this implying any type of restriction to the scope of the present invention, objects that can be decorated and / or enameled with the sheets object of the present invention can be cited as follows: tiles, dishes , steps, skirting boards, porcelain, etc.

For a better understanding of the object of the present invention, the manufacturing process of decorated enamel sheets is described below.

It is based on a slip of the enamel that wants to form in the form of a sheet, which, by any of the methods known and existing in the market (tape, curtain, etc.) is deposited on a support, usually of a plastic nature , although you can also use glass, metal, etc., forming a thin layer. Once said enamel layer is dried, it separates from the support, obtaining the corresponding sheet, which is decorated with the desired design by means of any of the known and existing methods in the market (screen printing, roller, decal, etc.). The drying of the sheet on the support can be free or controlled by different methods (air flow, electrical resistance, infrared, etc.), depending on the drying times of the chosen method.

SUBSTITUTE SHEET (RULE 26) A slipper means a suspension of particles of one or several frits and natural or synthetic raw materials (quartz, alumina, zirconium silicate, kaolin, clay, dolomite, feldspar, wollastonite, ceramic pigments, etc.) in water or other medium, including the necessary additives (binders, deflocculants, suspensions, plasticizers, defoamers, etc.) to achieve rheological, drying conditions, etc. suitable for a correct conformation of the sheet following the method described in the previous paragraph. The size of the particles that make up the slip is less than 800 μm, preferably less than 75 μm. The compositions of the sheets (mixture of frits, natural or synthetic raw materials and additives) are designed according to the product and final finish that is intended to be obtained. Thus, parameters such as softening temperature, expansion coefficient, melt viscosity, etc. must be optimized in each case, which is achieved by modifying the proportions of frit and raw materials. As a general rule, the higher the temperature at which the final product must be processed, the less amount of fritted material must be incorporated into the composition and a greater amount of natural and / or synthetic raw materials. As frits and natural or synthetic raw materials, all those normally used in the formulation of glazes for tiles, dishes, sanitary ware and other enameled ceramic products can be used, which are widely known and can be easily found in the state of art.

It is also necessary to optimize the rheological and forming conditions of the starting slip, which is achieved by modifying the proportions of the additives used. Basically, binders and plasticizers are used, which act as conformators, deflocculants, which act as theological regulators, antifoams, which act as deaerators and crosslinking agents, which act as stabilizers against moisture, although there may be others.

SUBSTITUTE SHEET (RULE 26) Among the possible use binders are polyvinyl acetate, polysaccharides, celluloses, polyvinyl alcohol, synthetic resins, polyvinyl pyrridone, acrylic binders, esterified polysaccharides, as well as copolymers of the foregoing, such as copolymer _. polyvinyl pyrridone with vinyl acetate, polyvinyl pyrrolidone with caprolactam or polyvinyl plasticized with ethylene, although others may exist. The proportion of binder in the slipper composition is normally less than 15 parts by weight per 100 parts of ceramic base (fried + raw materials) and preferably between 3 and 6 parts per 100 parts of ceramic base.

Among the plasticizers of recommended use are glycerin, polyethylene glycol, bentonite and clays, although the use of different ones is also possible. The proportion of plasticizer in the slipper composition is normally less than 6 parts by weight per 100 parts of ceramic base and preferably between 2 and 5 parts by weight per 100 parts of ceramic base. As deflocculants, defoamers and crosslinking agents, most of those on the market can be used, although their proportion in the slip is less than 5 parts per 100 parts of ceramic base and preferably 2 parts per 100 parts Ceramic base.

With regard to the medium or solvent, water is normally used, although it is also possible to use ethanol or isopropanol or a mixture thereof or other solvents of an organic nature. The proportion of medium in the slip is less than 35 parts per 100 parts of ceramic base and preferably less than 25 parts per 100 parts of ceramic base.

In short, the slip from which the decorated enamel sheet is formed will consist of 100 parts of ceramic base (mixture of frits and natural and / or synthetic raw materials), less than 35 parts of medium (preferably less than 25 ), less than 15 parts of binder, preferably between 3 and 6 parts, less than 6 parts

SUBSTITUTE SHEET (RULE 26) of plasticizer, preferably between 2 and 5 parts, less than 5 parts of deflocculant, preferably less than 2 parts, less than 5 parts of defoamer, preferably less than 2 parts and less than 5 parts of crosslinking agent, preferably less than 2 parts . Another different method for obtaining enamel sheets consists in initially preparing the enamel in question in the form of granules by any known method (granulation, atomization, etc.) and introducing said granules in a roller rolling equipment, which basically consists of two parallel cylindrical rollers located at a distance such that there is a space between their surfaces that matches the required thickness of the sheet to be formed. The enamel granules must have the necessary additives so that when they pass between the two rollers they join together forming the desired sheet. Said sheet can be decorated with the design selected by any of the methods known and existing in the market (screen printing, roller, decal, etc.). By any of the methods described, sheets of a specific format or continuous sheets of a given can be manufactured. width that can be rolled around an axis. These continuous sheets can subsequently be cut to the required sizes. The lamination methods set forth above have been mentioned by way of example only, since in the state of the art different methods can be found that are also perfectly valid for obtaining decorated enamel sheets.

Example 1: Decorated enamel sheet obtained by layered tape to decorate and / or glaze ceramic objects that are thermally processed at temperatures between 1180 and 1230 ° C.

SUBSTITUTE SHEET (RULE 26) A slip of the composition 1 of Table I is prepared by milling in alumina ball mill together with the amount of water necessary to reach a density of 1.84 g / cc, so that 95% of the particles of said slip are found below 45 μm. Once the air retained inside the slip has been removed by means of a vacuum pump, a homogeneous layer of the same is deposited by means of the technique of tape taping on a Mylar-type plastic support. The colage is made using an automatic gauge of 0.9 mm thick with a speed of advance of the plastic support of 0.15 m / min. The drying of the sheet is carried out with countercurrent air at a temperature between 60 and 90 ° C initially to subsequently pass to 100 ° C until a residual humidity of less than 0.5% is reached. The sheet detaches freely without the help of the plastic support, finally having a thickness of 0.4 mm and a weight of 650 g / m ² . On the enamel sheet obtained, screen printing pastes of the compositions 2, 3 and 4 indicated in Table 1 are applied by screen printing. The preparation of the screen printing pastes is carried out by any of the methods commonly used in the pavement and cladding sector. ceramic. Each of the silkscreen pastes provides a different color and drawing, so that overlapping them on the enamel sheet gives us a decorated enamel sheet that already has the appearance of the marble that is intended to be obtained. The decorated enamel sheet thus obtained is perfectly manageable and transportable, and can be used to decorate and / or glaze ceramic objects that are thermally processed at temperatures between 1180 and 1230 ° C.

SUBSTITUTE SHEET (RULE 26) TABLE

SUBSTITUTE SHEET (RULE 26)

Example 2: Decorated enamel sheet obtained by lacing on tape to decorate and / or glaze ceramic objects that are thermally processed at temperatures between 1050 and 1150 ° C.

The procedure is similar to that set forth in Example 2, but by grinding the composition 5 indicated in Table II. The sheet obtained is decorated by screen printing with screen printing paste of compositions 6, 7 and 8 of Table II. The decorated enamel sheet thus obtained is suitable for decorating and / or enamelling ceramic objects that are thermally processed at temperatures between 1050 and 1150 ° C. TABLE II

SUBSTITUTE SHEET (RULE 26)

SUBSTITUTE SHEET (RULE 26)

Example 3: Decorated enamel sheet obtained by rolling with rollers to decorate and / or glaze ceramic objects that are thermally processed at temperatures between 1050 and 1150 ° C.

To 100 parts of ceramic powder of particle size smaller than 75 micrometers composed of 85 parts of frit 3 and 15 parts of frit 4, 10 parts of polyvinyl alcohol are added and the intimate mixing thereof is carried out. Subsequently 23 parts of solvent are added, which in turn consists of 21 parts of water and 2 parts of glycerin. After an energetic mixture of all these components, the assembly is introduced into an extruder where, by performing a vacuum, a complete and homogeneous mixture of all the components has just been achieved, and then it is extruded. The exempted material is used to feed a roller rolling equipment, finally obtaining a 0.5 mm thick sheet that can be decorated by screen printing with screen printing pastes of the compositions 6, 7 and 8 indicated in Table II. The decorated enamel sheet is valid for decorating and / or enamelling ceramic objects that are thermally processed at temperatures between 1050 ° C and 1150 ° C.

SUBSTITUTE SHEET (RULE 26)

Claims

1'3 CLAIMS.

1.-Decorated enamel sheet, manufacturing method and its use in the ceramic industry, which allows obtaining any type of surface finish in the ceramic industry, characterized in that a mixture of frits and natural and / or synthetic raw materials are involved , of controlled particle size, together with necessary additives, such as binders, deflocculants, suspensions, plasticizers, etc., in amounts convenient to achieve adequate rheological properties to obtain a correct conformation of the sheet, and characterized in that it contributes in itself the decoration that you want to have in the ceramic object.

2. Enamel sheet according to claim 1, characterized in that the thickness of the decorated sheet can vary between 50 and 3000 μm.

3. Enamel sheet according to claim 1, characterized in that the size of the particles used in its formation is less than 800 μm, preferably less than 75 μm.

4. Enamel sheet according to claim 1, characterized in that a binder in less than 15 parts, preferably between 3 and 6 parts, a plasticizer intervenes per 100 parts by weight of ceramic base in an amount less than 6 parts, preferably between 2 and 5 parts, and a deflocculant, antifoam and crosslinking agents, each in an amount less than 5 parts, preferably 2 parts.

5. Method of manufacturing a decorated enamel sheet, according to claim

1, characterized in that either: a) a slipper or suspension of particles of one or more frits and natural or synthetic raw materials, such as quartz, alumina, zirconium silicate, kaolin, clay, dolomite, feldspar, wollastonite, ceramic pigments, etc., in water or other means,

SUBSTITUTE SHEET (RULE 26) together with the necessary additives to achieve good rheological properties, it is deposited on a support of plastic, metal, glass, etc., forming a thin layer, then drying the assembly by appropriate methods and times for each case, then separating the sheet formed of the support, or: b) the enamel is initially prepared in the form of granules, by known methods, such as granulation, atomization, etc., and said granules, together with the convenient additives, are introduced into a roller rolling equipment parallel, located at a distance from each other that coincides with the thickness of the sheet to be shaped, and then decorating, with the desired design, the sheet obtained, by known methods, such as screen printing, roller, decal, etc.

6. Use of an enamel sheet, according to claim 1, to decorate and / or glaze ceramic objects that have to undergo in their preparation temperatures between 1000-1250 ° C.

SUBSTITUTE SHEET (RULE 26)