US 3385748 A
Description (OCR text may contain errors)
May 28, 1968 K. w. J. NEALE ETAL. 3,385,748
WATER RELEASE TRANSFER Filed July l5. 1963 fggggcmr PRorEcr/vE DES/6N Z 2 4 LAYER 3 LAYER. Y
ADHESIVE F'LM 525%@ 7 United States Patent O 3,385,748 WATER RELEASE TRANSFER Kenneth William James Neale and David Wellings Pointon, Stoke-on-Trent, England, assignors to Johnson, Matthey & Company Limited, London, England, a British company Filed July 15, 1963, Ser. No. 295,054 Claims priority, application Great Britain, July 17, 1962, 27,390/ 62 1 Claim. (Cl. 161-6) 'This invention relates generally to improvements in and relating to the decoration of heat-resisting bases, that is to say, bases capable of withstanding firing at a temperature of at least 400 C. such as glass, fused silica, or pottery, and is more particularly concerned with the decoration of such bases with a design or decoration in gold by mean-s of decalcomanias or transfers.
A decalcomania or transfer for use in the decoration of a heat-resisting base usually comprises a sheet or backingor absorbent paper carrying a layer of Water-soluble gum to 'which is directly :applied either a cellulose support film, which itself carries a design to be applied to the base, or the design itself, which is then covered by a support film, which thus constitutes a covercoat as well as a support for the design after its release from the paper backing and before firing of the base decorated therewith. The design, which may be applied to the transfer paper in -any suitable manner, such as by the silk-screen printing method, may consist of a ceramic color or vitrifiable enamel or of a metallic Lustre composition, such, for example, as lthat known as Liquid Gold, which consists essentially of a solution of a sulpho-resinate of gold in lsuitable solvents, or of a mixtu-re of the two materials.
Whilst either of the -above two kinds of decalcomania may be employed for the application of vitrifiable enamel decorations, it has been found that the successful application of decorations in gold cannot be achieved with decalcomanias in which the design is `applied over the support film, but that it is essential to employ decalcom-anias of the covercoat type, that is to say those in which the support film overlies the design.
The covercoat support film at present used on decalcornanias carrying gold designs is of a cellulosic nature and based on ethyl cellulose. Such a covercoat enables a bright gold ldecoration to -be obtained on a glass or pottery base after firing, but is unfortunately not sufficiently fiexible for ease of handling and, consequently, diiculty is often experienced in applying a design film to an article of complicated shape such as is frequently produced in the pottery industry.
On the other hand, covercoat-type decalcomanias, carrying designs in ceramic color or vitrifiable enamel, usually employ resinous or resin-based covercoats, such, for example, as an acrylic resin, which possesses the physical characteristics, such as Iflexibility, required for ease of application to complicated shapes and is consequently much to be prefer-red to cellulose-based materials.
Whilst resin-based covercoat decalcomanias have proved eminently suitable for use for applying ceramic colors, attempts to use such covercoats with gold-designcarrying decalcomanias have met with little or no success, mainly owing to the fact .that reaction occurs between the lgold `design film and the covercoat which destroys not only the brightness of the fired gold film, but also its adherence to the base. It appears, moreover, that the usual solvents employed in the covercoat solution tend to dissolve the gold film and separate the 4resinous material in the gold composition.
The principal object of this invention is to overcome the above disadvantage in the use of resin-based coverlCe coats and to enable such covercoats to be successfully used with decalcomanias carrying a design :in gold.
Another object is to provide an improved gold-carrying decalcomania for use in the decoration of heat-resisting bases.
A further object of the invention is to provide an -improved method of decorating a heat-resisting base with designs in gold.
With these and other objects in view, the invention provides a decalcomania or transfer of the c-overcoat support film type in which the design is applied to -a paper backing beneath the support film Whichconstitutes the covercoat, which comprises a design layer formed of, or comprising a gold-containing composition, a covercoat support film formed of a resin-based material, and, between the `design layer and the covercoat film, a protective layer of an oxidizable or polymerizable material which is impervious to the covercoat material and is inert to the gold in the design layer.
By this means the `disadvantages -hitherto associated with resin-based covercoats on gold-design-carrying decalcomanias are entirely obviated yas the intermediate protective layer prevents penetration of any solvents from the covercoat film to the gold design and also prevents any reaction -between the resin in -the covercoat and the gold in the design layer during firing of the design on the base.
The invention also comprises a method of making a decalcomania or transfer of the covercoat support film type including the steps of applying 'a gold-containing design layer to a paper backing, applying, to the said layer, an intermediate protective layer of an oxidizable or polymerizable material which is inert to the gold in the design laye-r and then -applying to said intermediate layer a covercoat support film formed of a resin-based -material, said intermedate layer also being impervious to said covercoat material.
The intermediate protective layer may consist of :an alkyd resin, a phenolic resin, or a urea resin.
The covercoat support film may consist of any known resin-based covercoat solution at present used with cer-amic color or enamel decalcomanias, such, for example, as a methyl methacrylate resin-based film.
In carrying out the invention in practice, the intermediate polymerizable protective layer may advantageously have the following composition, namely,
Percent Short oil alkyl resin (60% non-volatile in xylol) 25.00
Cellulose nitrate 6.25 Plasticizer 6.25 High boiling solvent 62.50
A suitable covercoat support film may have the following composition:
The gold-containing design layer used may be any known and commercially available Liquid Gold preparation. The composition of such materials forms no part of this invention, and it will sufiice to Say that in general they are composed of -a sulpho-resinate of gold in suitable solvents, usually with the addition of the resinates of other metals. The design layer may consist solely of a gold preparation, or of a mixture of such a preparation and one or more ceramic colors or vitrifiable enamels, -according to the requirements of the final desired decoration.
The invention is illustrated, by way of example, in the accompanying diagrammatic drawing, the single figure of which represents a section through a transfer or decalcomania embodying the invention.
In the drawing, 1 represents a gummed paper backing, the adhesive layer being represented at 1a; 2 a design film or layer formed of a Liquid Gold preparation, 3 an alkyd resin protective layer of the above specified composition, and 4 a covercoat support lm also having the composition given above.
The layers 2, 3 and 4 are each preferably applied by the silk-screen printing method, the gold design layer being applied through a plain weave mesh screen having 200 strands to the inch. A coarser mesh screen having 90 strands to the inch is preferably used for applying the the composition given above.
Whilst in the above one example of the invention has been described, it is to be understood that the invention is in no way limited to, or by, this example, but that modications may be made thereto without departing from the scope of the invention. For example, any other suitable Liquid Gold design preparation may be used, and linseed oil or tung oil or another polymerizable resin other than an alkyd resin may be employed. Again, the covercoat may have a different composition from that given above. Furthermore, the constituent layers of the decalcomania need not be applied by the silk-screen printing method but any other suitable method, such as spraying or painting may be used instead.
It is, moreover, to be understood that the invention is intended to include within its scope a method of decorating a heat-resisting base with a design or decoration in gold with the use of decalcomania in accordance with,
or when made by the method of, the invention and any heat-resisting base when so decorated.
What we claim is:
1. A water release transfer of the covercoat support film kind comprising a paper backing carrying a layer of a water-soluble adhesive, a design layer comprising a sulfo-resinate of gold on the said layer of water-soluble adhesive, a protective layer comprising a material selected from the group consisting of alkyd resins, phenolic resins, and urea resins covering said design layer and a flexible covercoat lm formed of resin-based material covering the said protective layer including the edges of said protective layer and the edges of said design layer, the protective layer being impervious to the covercoat film and inert to the gold in the design layer.
References Cited UNITED STATES PATENTS 1,634,617 7/1927 Hart 156-240 1,658,263 2/1928 Stanley 40-21 1,888,154 11/1932 Allen et al. 117-3.3 2,017,367 10/1935 Kurz 117-3.3 2,124,232 7/1938 Kittredge et al. 117-122 2,970,076 1/ 1961 Porth 156-89 3,156,580 11/1964 Howard 117-75 FOREIGN PATENTS 784,966 10/ 1957 Great Britain.
EARL M. BERGERT, Primary Examiner.
H. F. EPSTEIN, Assistant Examiner.