AU624330B2 - Printing pad device for transferring specific quantities of printing medium per unit area - Google Patents

Abstract

In the printing pad device described, the surface of the pad (20) is recessed while retaining essentially the same external form and volume. Also described is the use of the pad for at least partially coating a substrate (22) with a predetermined pattern. The substrate (22) is a printed circuit board for manufacturing integrated circuits, a component of a pharmaceutical presentation and/or dosage form, a label with raised characters, a prepolymer or similar.

Description

Neuwied, Declared at. West Germany this 2nddaof My8 LTS LOHMA.NN.Therapie"-Systie Signe& A. 4 Status I 1(Dr.Al Hoffmnann)' (MaaB) Decfa&,Mjqtq~ Director (Head of Production)

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AU-AI -19356/88 *l 22<

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STWELTORGANISATION FfR GEISTIGES EGNU r6T Internationales Br INTERNATIONALE ANMELDUNG VEROFFENTLIGHT NACH DEM VERTRAGr OBER DIE INTERNATIu.,kALE ZUSAMMENARBEIT AUF DEM GEBIET DES PATENTW ESENS (PCT) (51) Internationale Patentklassjf-,ktiofl (11) Internationale Verofffentlichungsnummer: WO 89/ 01410 B41F 17/00, 1/16 Al (43) Iner (ati DnJA 2.0.9

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(21) Internationales Aktenzeichen: PCT/DE88/00364 (22) Internationales Anmieldedatumn: 16. Juni 1988 (16.06.88) (31) Prioritiitsaktenzeichen: (32) Prioritfitsdatum: P 37 27214.4 14. August 1987 (14.08.87) (33) Prioritlitsland: (71) Anmneder (ffar alle Bestimmungsstaaten ausser US): LTS LOHMANN THERAPIE-SYSTEME GMBH CO.

KG. (DE/DE]; Irlicher Strage 55, D-5450 Neuwied 12

(DE).

(72) Erfinder;und Erfindo.r/Anm elder (nur fiir US) ANHXUSER, Dieter [DE/DE]; Rengsdorfer Stra~e 4, D-5451 Meisbach KLEIN, Robert-Peter [DE/DE]; Wikinger Stra- Re 3, D-5450 Neuwied I I (DE).

(74) Anwalt: NEIDL-STIPPLER, Cornelia; Rauchstra~e 2, D-8000 Miinchen 80 (DE), (81) Bestimmungsstaaten: AU, DK, Fl, HU, JP, KR, NO, us.

Verbffentlicht Mit internationalem Recherchenberic?'t.

XDJP 2 7 APR 1989 S AUSTRALIAN -9 M'AIN) 1989 L_ PATEN rOI'Fic.F (54) Title: PRINTING PAD DEVICE FOR TRANSFERRING SPECIFIC QUANTITIES OF PRINTING MEDIUM PER UNIT AREA (54) Bezeichnung: TAMPONDRUCKVORRICHTUNG ZUR CJBERTRAGUNG DEFINIERTER MENGEN DRUCKMEDIUM PRO FLACHENEINHELT (57) Abstract in the printing pad device described, the surface of the pad (20) is recessed while retaining essentially the same external form and volume. Also described is the use of the pad for at least partially coating a substrate (22) with a predetermined pattern. The substrate (22) is a printed circuit board for manufacturing integrated circuits, a component of a pharmaceutical presentation and/or dosage form, a label with raised c;haracters, a prepolymer or similar.

(57) Zusammenfassung Die Erfindung betrifft eine Tampondruckvorrichtung zur Clbertragung definierter Mengen Druckmedium pro Fldcheneinheit, be; der die Oberfldche des Tampons (20) tinter Beibehaltung im wesentlichen der gleichen Au~enform und Formvoiumens vergbgert ist sowie deren Verwendung zur zumindest teilweisen Beschichtung von Substraten (22) in einem vorherbestimmten Muster, wobei das Substrat (22) eine Leiterplatte zur Herstelluing von integrierten Schaltungen, emn Bestandteil einer p harm azeutischen Darreichungs- und/oder Dosierungsform; emn Schila mit erhabenem Schriftzug, emn Prdpolymer u.dgl. ist.

22 2' 1 The invention relates to a pad printing device for transfer of clearly defined quantities of printing medium per surface unit, as well as the use thereof.

Pad printing processes have been known since 1968 and are also suitable for printing uneven surfaces to which adapt the flexible printing medium-transferring pad. An example of such a pad printer is described in US-A-4 060 031 (DE-OS 19 39 437). The pictorial element to be printed is etched in sunk manner in a block, that is, the printing form. The printing medium is transferred into said block following a doctor blade process which doses the printing medium received in the block, the pad completely absorbs the printing medium left behind in the block and transfers 0 0 it to the object to be printed. A survey of the uses and 0 0 So° 15 characteristics of the pad printing process appears in the brochure of Tampoprint GmbH, Daimlerstrasse 27/1, Korntal- Munchingen, to which reference should be made to avoid unnecessary repetition.

0'00' Due to their limited space requirements, pad printers 20 are very advantageous, because they can be integrated without difficulty in production lines and can also be encapsulated, which is helpful when processing highly 1 active or toxic printing media, such as medicaments, etching inks, polymerization initiators, etc., for the protection of operating personnel and for reducing the evaporation rate of volatile substanxces.

Hitherto no attempt has been made to use pad printers jcspe.023/lts 91 7 23 Ik 4 ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION NO. DE 8800364 SA 22752 74

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2 for the delivery of precisely controlled printing medium quantities. It has surprisingly been found that the known pad printing process permits an accurate dosing of weights per unit area of up to 26 g/m 2 in a printing process with a variance of 2% and below.

As described in AU-A-13959/88, even highly sensitive medicaments or control membranes for active substance deliveries can be applied with a constant weight per unit area to corresponding substrates.

The use of the hitherto known means, namely variation of the pad material (more printing medium is transferred in the case of softer pads) and the viscosity of the printing medium could only lead to the delivery of a slightly increased, but still constant quantity of printing medium to a substrate. However, this quantity was not sufficient for coating with higher weights per unit area, such as over 100 g/m 2 so that despite excellent characteristics, the pad printing process was unsuitable for uses such as the production of thicker layers of materials in a predetermined pattern and there has also been no interest up to now in applying coatings by using this process.

Instead complicated and costly screen-process printing or complicated multistage application processes were used.

The problem of the present invention is to so develop the known device that it is also possible to transfer to a substrate larger printing medium quantities than is possible with conventional pads.

jcspe.023/lts 91 7 23 1-) 1~ r s i:r E;i ;li~ w!:i 1 a rl i 1 _i i 2a- The invention provides a pad printing device for transferring clearly defined quantities of printing medium per surface unit, characterized in that the surface of the pad is enlarged whilst essentially retaining the same external shape and shape volume.

The surface enlargement can e.g. comprise screening, roughening, grooving or burling the pad surface and by working a finished pad body, or by producing the enlarged pad surface during moulding of the pad body in a suitable mould. Compared with conventional pads with a smooth surface, the novel pad is suitable for transferring more than three times the hitherto transferable printing medium quantity.

As a result of the inventive development of the known 15 pad printer, it is possible for the first time to use these machines or this process S a o a. jcspe.023/lts 91 7 23 -74 a1- -L i I- il i- -1 .~-01

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-3in completely new fields and in advantageous manner for producing coatings. It is therefore e.g. usable in the production of signboards with a thicker paint application, integrated circuits, in which photolacquers or conductor materials can be printed, as well as for the planned application of polymerization initiators to prepolymers, for applying etching liquids for producing etching patterns, for transferring porcelain paints, for producing pharmaceutical adminisl:ration and/or dosage forms, such as tablets, as well as dermally applicable systems, which also includes those systems supplying substances through mucous membranes, i.e. rectal and vaginal administration forms. A particularly preferred use is in the production of plaster-like, transdermal therapeutic systems.

The invention makes it possible to unexpectedly increase the printing medium quantity delivered in a printing process and still obtain a constant dosing vithin narrow limits.

The inventive device makes it possible for the first time to produce in a desired form active substance-containing printing media and small active substance doses without any loss of the active substance, such as has been hitherto possible in the surface coating processes, e.g.

for transdermal therapeutic systems, whereby expensive active substance is saved and it is possible to obviate the problem of active substance waste elimination.

It is now possible in a single production stage through the use of suitable blocks to apply simultaneously and in spatially clearly separated manner several printing media, such as e.g. several dyes, dyes and adhesive, adhesive and an aseptic or active substance-containing product in the case of plasters or therapeutic systems and consequently to save one production stage. The block and also the pad can be thermally controlled, in the case of having to process temperature-sensitive materials, or materials only processable in the heated state, such as certain adhesives. It is possible in the same way to cool the same and the complete device, if temperature-sensitive materials are to be worked or processed.

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a i ti ii r ,i Through the choice of a suitable pad material it is possible to take account of the different requirements, so that all rubber-elastic materials known to the Expert are suitable, such as natural and synthetic rubber and in particular silicone rubber, which can be selected in accordance with the required properties, such as workability, solvent resistance, thermal stability or adequate elasticity at low temperatures.

The pad shape can be chosen in accordance with the substrate to be processed. Thus, it is possible to use any conventional shape, such as frustum-shaped, as well as flat or oval pads with an enlarged printing surface.

By means of the inventive device, it is possible in one printing process to transfer a weight per unit area of approximately 200 g/m 2 of printing medium and more. A further improvement to the transfer quantity can be achieved by process improvements known to the Expert, such as the use of softer pads, other printing media, etc.

Further features and advantages of the invention can be gathered from the following description relative to the drawings, wherein show: Fig. 1 a pad printer on applying a printing medium coating to a substrate.

Fig. 2 the pad printer according to fig. 1 on taking up new printing medium from the block.

SFig. 3 an inventive pad with an enlarged surface area.

Fig. 4 a further inventive pad with an enlarged surface area.

Fig. 5 a cross-section through a transdermal, plaster-like, therapeutic system produced by the inventive device.

Fig. 6 a plan view of a further active substance coating produced I I 5 with the inventive pad printer and having two different active substances.

Fig. 7 a further preferred administration form, namely a dragee produced with the inventive device.

Fig. 1 shows the application of a printing medium coating with an inventively constructed pad 20 to a flat substrate 22. An elastic, oval silicone rubber pad 20 with a printing medium coating on the enlarged surface area 23 taken in the preceding working stage of the device from the cavity of a block 24 shaped in accordance with the desired pattern for the application of the printing medium (cf. fig. which was printed on the flat substrate 22, on which it leaves a uniform printing medium coating thickness following the removal of pad 20. It is possible in the same way to print uneven substrates, e.g. circular substrates or corrugated substrate surfaces, such as utensil shapes, etc.

Fig. 3 shows a preferred development of an inventive oval pad 20, on whose upper area 23 used for printing medium transfer are formed groovelike depressions as a surface enlargement and as a result of which it is possible to absorb and transfer larger printing medium quantities.

The absorbed printing medium quantity in the present process is determined by the etching depth and shape of the pad 24 from which the printing medium is completely removed, after previously being placed in a uniform coating thickness on the block by means of a doctor blade process and in this form is removed and transferred.

Fig. 4 shows another preferred development of the pad 20, which in this case is essentially roller-like. On the transfer or application surface of the pad are formed cups for enlarging the surface and which also serve to receive increased printing medium quantities.

Fig. 5 shows an active substance-containing plaster which can be produced by means of the device according to the invention. This can e.g. be produced by the uniform pressing of a ring-like, active substance- 1-

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-6 impermeable acrylate contact adhesive coating 16 to a cover film which in this case is siliconized paper removed prior to the use of the plaster, as well as a circular control coating 18, which controls through constant thickness and its physicochemical characteristics the substance passage and printing on by means of an inventive pad printer an active substance-containing reservoir coating 14 and subsequent lamination with an impermeable backing, in this case an aluminium-polyester laminate 10. Both the control coating 18, whose characteristics are only ensured in the case of high thickness constancy, and the active substance coating 14, whose active substance content is also only ensurable in the case of high thickness and surface constancy of the applied coating in a form suitable for pharmaceutical uses, can be applied by means of the inventive device.

Fig. 6 shows a plaster as in fig. 5 prior to the application of the backing 10, this plaster having two active substances 14 and 14'. This embodiment can also be produced with a single active substance application stage using the inventive pad printer, it once again being possible to see the active substance-impermeable contact adhesive ring 16.

Fig. 7 shows another pharmacological administration form which can be produced with the inventive device, namely a sugar-coated dragee with a two-coat core 34,36, which can be produced by printing the coating 36 on a circular substrate 34, without any wastage of the substrate material 34, or the print coating 36.

Further developments, combinations and uses of the inventive device are readily apparent to the Expert and fall within the protective scope of the present claims.

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Claims (7)

1. A pad printing device for transferring clearly defined quantities of printing medium per surface unit, said device using a flexible elastic pad for transferring the said clearly defined quantities, characterized in that the surface of the pad is enlarged whilst essentially retaining the same external shape and shape volume.

2. A device according to claim 1, characterized in that the surface enlargement comprises screening, roughening, grooving or burling of at least part of the pad surface used for transferring the printing medium. C C¢

3. A device according to claim 1 or claim 2, characterized in that the enlargement of the pad surface takes place by working a finished pad body.

4. A device according to claim 1 or claim 2, character- ized in that the enlarged pad surface part can be produced in a suitable mould during the moulding of the pad body.

5. The device according to any preceding claim when used for the at least partial coating of substrates in a predetermined pattern, the substrate being a circuit board for producing integrated circuits, a component of a pharmaceutical administration and/or dosage form, a signboard with raised characters, a prepolymer, etc.

6. The device according to claim 5, characterized in that the pharmaceutical administration and/or dosage forms is a dermally applyable system, such as a transdermal r therapeutic system. jcspe.023/lts 92 3 Ai ~~:rlii 1i 8

7. A pad printing device substantially as herein described with reference to the accompanying drawings. DATED this 23 July 1991 CARTER SMITH BEADLE Fellows Institute of Patent Attorneys of Australia Patent Attorneys for the Applicant: LTS LOHMANN THERAPIE-SYSTEME GmbH CO KG a o* o o a a4 a o o o aD *6o e De 6 0 jcspe.023/lts 91 7 23 ij i:, ji i: jj -L 1 -li -P C