JP2876027B2 - Display method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a display method for ceramics, for example, glazed ceramic substrates, pottery products such as toilet bowls, metals, for example, engine blocks, glass, for example, CRTs for televisions, etc. is there.

[Conventional technology]

Conventionally, various surface coatings have been applied to inorganic objects such as ceramics, metals, and glass for the purpose of improving the properties such as surface smoothness, abrasion resistance, corrosion resistance, and surface hardness, and for decorative purposes. Have been done.

As a method therefor, there is a method of surface coating by a vacuum deposition method, a sputtering method, or the like. However, these methods have disadvantages such as expensive equipment and difficulty in forming a thick coating layer.

As another method, there is a method of applying a paste containing an inorganic powder and a resin binder as main components by a screen printing method and firing the paste. However, this method also has many drawbacks, such as the screen printing method, which limits the film thickness that can be formed at one time, and has other problems such as poor workability and extremely difficulty in printing on a curved surface.

In order to solve such difficulties of the conventional coating method, a composition containing glass powder and a resin binder as main components, and adding an inorganic powder as necessary, is applied as it is or on an appropriate supporting substrate. A method has been proposed in which a glass powder sheet is adhered to an inorganic object via a pressure-sensitive adhesive layer, and then fired.

In this method, since the glass powder is used in advance as a sheet using a resin binder together with the inorganic powder as necessary, the thickness of the coating layer can be freely selected, and the thick coating layer can be easily formed. And the thickness of the coating layer can be accurately defined. Therefore, a device such as a conventional vacuum vapor deposition method or a sputtering method is not required, and there is no difficulty based on the screen printing method. Further, in this method, when laminating the powder sheets, the lamination is performed via the pressure-sensitive adhesive layer, so that it can be performed extremely easily and easily.

[Problems to be solved by the invention]

This method is a method of coating an inorganic substance with a glass powder. However, if the above-mentioned excellent features of this method are used as they are, printing is performed on one surface of the powder sheet with a heat-resistant ink, that is, display is performed. It is considered that heat resistance can be easily and easily displayed on the inorganic object.

The present inventor has started substantial research on this display method based on the above technical idea, and has found out the following. That is, due to the presence of the pressure-sensitive adhesive layer, the powder sheet can be easily and easily adhered to the inorganic object. However, when the powder sheet is fired, the pressure-sensitive adhesive layer disappears by firing, and the powder sheet becomes inorganic material. It has been found that a phenomenon of peeling or moving from the body may occur. This peeling or movement is by no means desirable in terms of dimensional stability, and particularly in the case of display with heat-resistant ink, the fact that peeling or movement of the ink cannot be performed clearly is a fatal problem. It is a difficult point.

Therefore, the problem to be solved by the present invention is to solve the above-mentioned new difficulties found in the study of the present inventors.

[Means for solving the problem]

The problem is that glass powder and a resin binder are the main components, and inorganic powder is added as needed to form a powder sheet. A printing layer is formed on one side of the obtained powder sheet with heat-resistant ink, and pressure-sensitive adhesive is bonded on the other side. A pressure-sensitive adhesive layer on the object to be coated via the pressure-sensitive adhesive layer, and then sintering, and the thermal decomposition temperature of the pressure-sensitive adhesive layer is such that the powder sheet The problem is solved by using a resin binder which is at least 30 ° C. higher than the thermal decomposition temperature of the constituent resin binder.

[Configuration and operation of the invention]

In the present invention, a pressure-sensitive adhesive whose thermal decomposition temperature is at least 30 ° C. higher than the thermal decomposition temperature of the resin binder constituting the powder sheet is used. The reason for this is that when the temperature is less than 30 ° C., the thermal decomposition temperature difference is small, and the decomposition of the pressure-sensitive adhesive occurs before the decomposed product of the resin binder disappears, and the decomposed product may not be reliably removed, which is not preferable. .

In the present invention, the following effects are exhibited by using a material which is at least 30 ° C. higher. First, by using the pressure-sensitive adhesive, even if the resin binder of the powder sheet disappears in the baking process, the powder sheet adheres to the object to be coated due to the presence of the pressure-sensitive adhesive and does not peel off. Thus, printing or display with extremely excellent dimensional stability can be performed. In other words, the heat-resistant ink is printed by an appropriate means such as a thermal transfer method, and then, after baking, the sticking workability is good based on the above-mentioned excellent effect by the pressure-sensitive adhesive, and the dimensional stability is extremely high. It is possible to produce excellent heat-resistant printed matter. or,
By forming the pressure-sensitive adhesive layer on the other surface of the powder sheet in advance, temporary attachment to the release liner becomes possible, and the powder sheet with the adhesive layer can be kept in a labeler shape, and handling is easy. Also, the formation of the printing layer is facilitated.

Usually as the glass powder in the present invention PbO-B ₂ O ₃
-SiO ₂ glass and Na ₂ O- for lead-free type
Known materials such as B ₂ O ₃ —SiO ₂ and BaO—CaO—SiO ₂ can be used. The size of the glass powder at this time is usually 0.
It is about 1 μ to 50 μ, preferably about 0.5 μ to 10 μ.

If necessary, an inorganic powder may be added to the glass powder. This inorganic powder is used for the purpose of improving the surface properties and imparting a coloring function, and its particle size is usually about 0.1 μ to 100 μ, preferably about 0.5 μ to 50 μ. The amount used is about 1 to 50 parts by weight based on 100 parts by weight of the glass powder. Preferred as inorganic powders are SiC, SiN ₄ , BN, Al ₂ O ₃ , Zr
O ₂ , SiO ₂ , TiO ₂ , BaTiO _{3 and the} like can be exemplified.

On the other hand, as the resin binder, a hydrocarbon polymer, a vinyl resin, an acetal resin, an acrylic resin, a styrene resin, a polyester resin, a synthetic polymer such as a polyurethane resin or a semi-synthetic polymer such as a cellulose resin can be used. Hydrocarbon resins, acrylic resins, acetal resins, and cellulose resins are preferred because of easy thermal decomposition, and acrylic resins are particularly preferred. Thus, the amount varies depending on the specific gravity and particle size of the glass powder or the inorganic powder, but is preferably in the range of 5 to 40 parts by weight with respect to 100 parts by weight of the glass powder. If it is too small, it causes foaming. If the amount is too small, the strength of the powder sheet is reduced, so that the workability is significantly deteriorated. Further, in the present invention, a dispersant can be used in order to enhance the uniform mixing of the glass powder or the inorganic powder with the resin binder. As the dispersant at this time, other various surfactants, fatty acids, fatty acid esters, fish oils, acrylic oligomers and the like can be used. The amount of the dispersant used at this time is 0.0 with respect to 100 parts by weight of the total amount of the glass powder and the inorganic powder.
It is about 1 to 10 parts by weight, preferably about 0.1 to 2 parts by weight.

When preparing a powder sheet, a suitable solvent, an additive such as an antifoaming agent, etc. are added to the above-mentioned composition components, and a powder sheet can be prepared by a usual doctor blade method or the like. That is, a glass powder, a resin binder, a solvent, and additives such as an inorganic powder dispersant and a release agent, if necessary, are mixed with a ball mill, and a powder sheet having good thickness accuracy can be obtained by casting with a doctor blade. it can. In addition, by sufficiently defoaming the slurry before casting, it is possible to prevent bubbles from remaining inside the sheet. In preparing the powder sheet, an appropriate base film may be used and cast thereon. As the base film at this time, one that disappears in the subsequent baking step is used, and examples thereof include various synthetic resin films.

The heat-resistant ink used in the present invention contains a metal oxide and a heat-fusible binder as main components, and further contains various additives as necessary.

Various types of metal oxides are widely used, and examples thereof include oxides containing at least one kind of metal such as cobalt, chromium, iron, copper, manganese, aluminum, and titanium. And (CuMn), (CrMn) ₂ O ₄ , CuCr ₂ O ₄ ,
(CoFe) (FeCr) ₂ O _{4 and the} like.

As the heat-fusible binder, wax is generally widely used, and the type thereof is not particularly limited. Preferably used wax, for example, paraffin wax,
Micro wax, paraffin wax such as polyethylene wax, natural wax such as beeswax, carnauba wax, wood wax, esters such as Hoechst wax, higher alcohol wax such as stearyl alcohol, palmityl alcohol, stearoamide, oleoamide And higher ester amide waxes such as butyl stearate, ethyl palmitate and myristyl stearate.

A polymer may be used in combination as the heat-fusible binder. Either a hydrophilic polymer or a hydrophobic polymer can be used, and a polymer having a softening point of 40 to 200 ° C. based on the ring and ball method is preferably used. Examples of hydrophilic polymers include gelatin, derivatives thereof, cellulose derivatives, natural products such as proteins such as casein and polysaccharides such as starch, derivatives thereof, polyvinyl alcohol, polyvinyl pyrrolidone, and water-soluble synthetic polymers such as acrylamide polymers; Polymer latex such as vinyl latex and urethane latex are exemplified. Examples of the hydrophobic polymer that can be preferably used include polyvinyl butyral, polyvinyl formal, polyethylene, polypropylene, polyamide, ethyl cellulose, cellulose acetate,
Polystyrene, polyvinyl acetate, and the like can be given.

The composition ratio of the metal oxide, the wax, and the polymer in the heat-resistant ink may be appropriately determined. Generally metal oxide
Per 100 parts by weight, 10 to 500 parts by weight of wax, preferably
30-400 parts by weight, polymer 0-500 parts by weight, preferably 1
~ 400 parts by weight are used. The ink is prepared by appropriately mixing them.

The ink of the present invention may be printed on a powder sheet as it is, or may be formed into a sheet in advance. In this case, the ink sheet is usually held by applying or impregnating the support base material with ink.

As a supporting substrate, for example, plain paper, condenser paper,
Laminated paper, papers such as coated paper, films or paper-film composites made of resin such as polyethylene, polypropylene, polyester, polystyrene, polyimide, metal sheets such as aluminum foil, cloth made of fibers such as nylon, polyester, etc. can give.

The method for holding the ink on the supporting substrate is not particularly limited, and a known method may be applied. As an example thereof, there is a method in which a liquid obtained by dissolving or dispersing the ink in an appropriate solvent is applied to a supporting substrate. At that time, as the solvent, an appropriate solvent such as toluene, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, methanol, ethanol, isopropanol, solvent naphtha, hexane, heptane and the like may be used. The coating may be performed using an appropriate coating machine such as a reverse roll coater, an extrusion coater, a gravure coater, or a wire bar. When the ink is provided as a coating layer on a supporting substrate, its thickness is suitably 15 μm or less, and preferably 2 to 8 μm. The surface of the supporting substrate on which the ink coating layer is not provided may be arbitrarily configured.

Using the obtained ink sheet or printing the ink as it is on a glass powder-containing powder sheet by a suitable method such as a thermal transfer method. This pattern can be arbitrarily displayed such as printing, barcode, picture, and the like. As a printing method, not only a thermal transfer method but also various methods such as a screen printing method can be adopted.

In the present invention, the above-mentioned powder sheet, which has been subjected to arbitrary printing using a heat-resistant ink, is adhered to an object to be coated via a pressure-sensitive adhesive. As objects to be coated,
A wide variety of materials can be used as long as they do not deteriorate in the next firing step, and typical examples thereof include ceramic, glass, and metal.More specifically, glazed ceramic substrates, ceramics for toilet bowls, and engine blocks. And glass such as a CRT of a television, and ceramic and glass are particularly preferable.

As a method of sticking, a pressure-sensitive adhesive is applied to one surface of the powder sheet in advance. At this time, in order to obtain a product having a heat resistant display with good appearance, the powder sheet needs to be sufficiently adhered to the object to be coated, and the resin binder in the powder sheet disappears during firing. It is important that the powder sheet does not peel before. Therefore, by increasing the thermal decomposition temperature of the pressure-sensitive adhesive by at least 30 ° C. higher than that of the resin binder constituting the powder sheet, even after the resin binder constituting the powder sheet is burned down in the subsequent sintering process. Even so, the adhesion is still good, and a printed matter having excellent dimensional stability, that is, a display matter can be obtained. In addition, by setting the thermal decomposition temperature of the pressure-sensitive adhesive layer to be particularly higher by 30 ° C. than that of the resin binder, it is possible to obtain a printed layer having no damage on the surface and excellent appearance accuracy. That is, if the thermal decomposition temperature of the pressure-sensitive adhesive is not set at least 30 ° C. higher than the resin binder, it is difficult for the decomposed product of the pressure-sensitive adhesive to disappear, and the adhesiveness and abrasion resistance are lacking. The appearance accuracy of the print layer surface is reduced.

In other words, the disappearance of the decomposed product of the resin binder forms a bypass in which the decomposed product of the pressure-sensitive adhesive disappears, whereby the decomposed product of the pressure-sensitive adhesive is reliably eliminated.

Acrylic pressure-sensitive adhesives containing butyl acrylate, 2-ethylhexyl acrylate, etc. as main components as pressure-sensitive adhesives,
Alternatively, a rubber-based pressure-sensitive adhesive containing butyl rubber or the like as a main component is preferable. The thickness is preferably in the range of 1 to 50 μm. If it is too thin, the adhesion is not sufficient, and if it is too thick, it causes foaming.

The object to which the powder sheet obtained as described above is adhered is fired at a temperature higher than the melting temperature of the glass powder. This temperature is usually 350 to 1400 ° C., and the resin binder and the pressure-sensitive adhesive used for forming the sheet disappear during this firing.

〔The invention's effect〕

By this method, an arbitrary display pattern is printed on a powder sheet in advance with a heat-resistant ink and at least 30 ° C. higher than a thermal decomposition temperature for an object such as ceramic, glass, metal, etc. Printing with excellent abrasion and extremely excellent dimensional stability, that is, display can be performed. In particular, by setting at least 30 ° C. higher than the thermal decomposition temperature, a printed layer having no damage on the surface and having excellent appearance accuracy can be obtained.

Further, by forming a pressure-sensitive adhesive layer on the other surface of the powder sheet, handling becomes easy and formation of a printed layer becomes easy.

〔Example〕

Examples are shown below. In the following examples, parts are by weight.

Example 1 A copolymer of butyl acrylate, methyl methacrylate, and methacrylamide (60: 35: 5, thermal decomposition temperature of 560 ° C.) 15 with respect to 100 parts of a SiO ₂ —CaO—BaO-based glass powder of 325 mesh or less15
Parts, 1 part of oleic acid as a dispersant, 24 parts of toluene and 16 parts of methyl ethyl ketone were mixed at room temperature using a ball mill, and then cast on a polyester film (thickness: 75 μm) using a doctor blade to form a powder sheet having a thickness of 100 μm. Obtained. Next, a pressure-sensitive adhesive mainly composed of a 100 μm butyl acrylate copolymer was laminated.
However, the composition of this pressure-sensitive adhesive is butyl acrylate / acrylic acid (100/5), and its thermal decomposition temperature is 590 ° C.

Separately, 50 parts of CuCr ₂ O ₄ (pH 6.0), 45 parts of paraffin wax, and 5 parts of ethylene / vinyl acetate copolymer were uniformly dispersed in toluene by a roll mill to prepare a heat-resistant ink coating solution.

This coating solution is applied on a 5 μm-thick polyester film by a coating machine so that the thickness after drying is about 5 μm,
After drying, an ink sheet was prepared.

Next, the ink sheet was cut into a predetermined width to form a thermal transfer ribbon, which was housed in a case to obtain an ink ribbon cartridge for thermal transfer.

Using a normal thermal transfer printer through the above ink ribbon cartridge, a predetermined bar code pattern is printed on the glass powder containing layer of the powder sheet obtained by the above method,
A pattern sheet was obtained. Next, on a ceramic molded body made of silicon nitride, a powder sheet coated with the above adhesive was attached, and after debinding at 400 ° C. for 30 minutes, the temperature was raised at a rate of 20 ° C./min for 10 minutes at 1000 ° C. Holding and firing. Prints having good appearance accuracy were formed on the surface of the obtained molded body. The printed pattern had good heat resistance and abrasion resistance. Note that the paraffin wax and the ethylene / vinyl acetate copolymer in the heat resistant ink were burned off during firing.

The following 150 mesh containing Example 2 PbO 80 wt% PbO-B ₂ O ₂
90 parts of system glass powder and alumina powder of 325 mesh or less 10
Of the mixture, 10 parts of isobutyl methacrylate (pyrolysis temperature: 400 ° C.) as a resin binder, 1 part of lauric acid as a dispersant, and 35 parts of toluene as a plasticizer were mixed at room temperature in a ball mill. And cast it with an applicator to a thickness of 80μ.
Powder sheet was obtained. Next, a pressure-sensitive adhesive mainly composed of butyl rubber was laminated to a thickness of 10 μm to obtain a powdery tape-like sheet. However, the thermal decomposition temperature of the pressure-sensitive adhesive was 460 ° C. Next, a pattern sheet was formed on the glass powder-containing layer by the same method using the same heat-resistant ink as in Example 1 above.

Then, the tape-like sheet is attached onto a LiO ₂ -Al ₂ O ₃ -SiO ₂ based heat-resistant glass molding, and the temperature is raised to 10 ° C./min.
It baked by holding for 10 minutes. The obtained pattern had good precision, had no problem in appearance, and had excellent heat resistance and abrasion resistance.

Example 3 A predetermined barcode pattern was printed on the glass powder-containing layer of the glass powder-containing sheet obtained in Example 2 by using a normal thermal transfer printer via the ink ribbon cartridge manufactured by the method of Example 1. Thus, a pattern sheet was obtained.

The above-mentioned pattern sheet was adhered to an alumina molded body whose surface was heated and oxidized via the pressure-sensitive adhesive layer.
Similarly, baking was performed at 500 ° C. for 10 minutes to form a baking pattern.

The obtained fired pattern was excellent in heat resistance and abrasion resistance and excellent in appearance accuracy.

Example 4 A heat-resistant pattern was formed in the same manner as in Example 3 except that SUS430 (thickness: 0.2 mm) was used instead of the alumina molded body in Example 3. It was excellent in heat resistance, abrasion resistance, appearance and accuracy.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Souji Nishiyama 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nichidenki Kogyo Co., Ltd. (72) Inventor Makoto Honda 1-1-1, Shimohozumi, Ibaraki-shi, Osaka No. 2 Nitto Electric Industry Co., Ltd. (56) References JP-A-56-126467 (JP, A) JP-A-63-71366 (JP, A) JP-A-58-215395 (JP, A)

Claims (3)

(57) [Claims] (1) A powder sheet is formed by adding (b) a glass powder and a resin binder as main components and, if necessary, an inorganic powder on the object to be coated. A sheet in which a printing layer is formed on one side of the sheet with a heat-resistant ink and a pressure-sensitive adhesive layer is provided on the other side are laminated under pressure through the adhesive layer, and (e) subsequent firing. ,
(F) The thermal decomposition temperature of the pressure-sensitive adhesive layer is at least lower than the thermal decomposition temperature of the resin binder constituting the powder sheet.
A display method characterized by being 30 ° C higher. 2. The display method according to claim 1, wherein the resin binder is an acrylic resin. 3. The display method according to claim 1, wherein the heat-resistant ink comprises a metal oxide and a heat-fusible binder.