AU652828B2 - Multilayered printable sheet structure - Google Patents

Description

OPI DATE 30/12/92 AOJP DATE 11/02/93 APPLN. ID 17507/92 PCT NUMBER PCT/AU92/00218 IIIll l illll III 1 11111 1111111 AU9217507 INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) International Patent Classification 5 (11) International Publication Number: WO 92/21119 G09F3/10 Al (43) International Publication Date: 26 November 1992 (26.11.92) (21) International Application Number: (22) International Filing Date: PCT/AU92/00218 15 May 1992 (15.05.92) lVrinr~ty Jaw PK 6204 (81) Designated States: AU. CA. GB. JP. US.

Published With inter.'ational search report.

652828 17 1%1ay l991 (17,05.91) (71) Applicant (for all designated States except US): NYLEX CORPORATION LIMITED [AU/AU]: 15th Floor, 390 St. Kilda Road, Melbourne, VIC 3004 (AU).

(72) Inventor; and Inventor/Applicant (for US onlr) GEMMELL, Daniel, Paterson [GB/AU]: 20 Cyril Grove, Noble Park, VIC 3174

(AU).

(74)Agent: PHILLIPS ORMONDE FITZPATRICK; 367 Collins Street, Melbourne, VIC 3000 (AU).

(54) Title: MULTILAYERED PRINTABLE SHEET STRUCTURE (57) Abstract A multilayered printable sheet structure comprising a self-adhesive film consisting of: a vinyl base layer having a first and second surface; (ii) a printable layer bonded to said first surface, said printable layer including one or more fillers and/or pigments; and (iii) an adhesive layer on said second surface; and a backing sheet consisting of: (iv) a paper backing layer having a first and second surface; an adhesive-release agent layer on said first surface intermediate said paper backing layer and said adhesive layer; and (vi) a moisture barrier layer on said second surface of said backing layer.

WO 92/21119 PCI/A U92~r/0 02 8 1 MULTILAYERED PRINTABLE SHEET STRUCTURE This invention relates to a multilayered sheet structure and more particularly to a sheet structure incorporating a self adhesive label and backing sheet. It will be convenient to describe the invention with r ffELci to itb alicicu mu ouccoc- :itut.u.s and being printed upon by laser printer or photocopier.

However it should be noted that the invention has a wider application.

Various types of self-adhesive paper labels are known. Self-adhesive paper labels are, for example, commonly used to provide address indicia for envelopes.

The address indicia may be printed on to such labels by means of offset printing or other conventional printing techniques; or alternatively, the labels may be blank and receptive to typed or hand written address indicia.

It will be appreciated that the usefulness of self-adhesive labels is not confined to use on envelopes; such labels are also used as "bumper stickers" oi "decals". However, paper labels are not generally suitable for outdoor use because they do not have the required durability and resistance to weather, so outdoor self-adhesive labels are generally made from polymeric materials.

It is generally difficult to write or print onto polymeric materials because they are generally not as receptive to ink or other forms of marking as is paper.

Moreover, the inks which do print on polymeric materials generally utilize hazardous solvents. Thus labels suitable for outdoor use are normally pre-printed and do not allow a user to insert information of his choice, as do paper labels.

With the present widespread use of photocopiers and laser printers, and with the increasing availability of colour photocopiers and colour laser printers, it has become easy and convenient for people to create their own signs, posters and other graphic materials. In certain applications, the usefulness of such materials and designs WO 92/21119 PC/A U92/00218 2 is enhanced if the medium on which they are printed is in the form of a self-adhesive label particularly on labels which are weatherproof.

A particular problem arises in the use of self-adhesive labels in conventional laser printers and photocopiers, in that laser printers and photocopiers normally operate by fusing toner onto the paper or other print medium, so that the print medium must be able to T^thstand a high temperature and pressure. This presents particular problems when the print medium is a self-adhesive label, in that the label, the adhesive, and the backing sheet must all be able to withstand the high temperatures and pressures.

Adhesives often break down at high temperatures, but adhesives which can withstand high temperatures are known. A more important problem is the provision of a backing sheet which can withstand high temperatures. A common problem with backing sheets for self-adhesive labels is that they shrink or distort when subjected to high temperatures. This results in wrinkling or curling of the label. As modern laser printers and photocopiers require that the material being printed remain flat, such deformation leads to unsatisfactory performance of the printing onto the self-adhesive labels.

Accordingly, there is a need for a self-adhesive printable label suitable for outdoor use which can withstand the temperatures and pressures encountered in modern photocopiers and laser printers without deforming during the printing process.

Accordingly, the present invention provides a multilayered printable sheet structure comprising a self-adhesive film consisting of:a vinyl base layer having a first and second surface; (ii) a printable layer bonded to said first surface, said printable layer including one or more fillers and/or pigments; and (iii) an adhesive layer on said second surface; and a backing sheet consisting of:- WO 92/21119 PC/AU192/0021 8 3 (iv) a paper backing layer having a first and second surface; an adhesive-release agent layer on said first surface intermediate said paper backing layer and said adhesive layer; and (vi) a moisture barrier layer on said second surfac: of said backirg iayei.

The vinyl base layer may be of any suitable size, shape and thickness. The base layer must be of suitable thickness to impart sufficient strength to the film so that the film does not stretch or shrink excessively once removed from the backing sheet. The base layer may be of any width and length convenient for manufacture by way of conventional polymeric film manufacturing equipment.

Optionally, various modifiers may be added to the vinyl base layer to impart desirable characteristics to the layer. For example various ultraviolet stabilizers, plasticizers and pigments may be added to the base layer so to provide desired properties as is well known in the art.

A printable layer is bonded to one surface of the vinyl base layer. The printable layer is preferably capable of accepting toner used in conventional laser printers and photocopiers. Preferably it should also be sufficiently thermally stable so as not to deform when subjected to the temperatures and pressures normally encountered in such machines. In a preferred embodiment, the printable layer comprises a vinyl based lacquer including a filler and pigments. Suitable fillers may include cellulose to improve printability of the printable layer. The filler may act as a binder to bind pigment particles together and to the vinyl base layer and to assit adhesion of the printable layer to the t, .se layer.

Suitable binders include poly(vinyl alcohol), acrylic based emulsions and poly(vinyl acetate) suitable pigments include titanium dioxide, magnesium oxide, calcium carbonate, kaolin clays, and silicas. Coloured p' rnents may be included in the printable layer. In a preferred embodiment of the present invention the printable layer 6VO 92/21119 PC'/AU92/00218 4 comprises 85% to 95% vinyl, 1% to 10% cellulose, 1% to titanium dioxide and 1% to 5% magnesium oxide.

The adhesive layer is on the opposite side of the base layer to the printable layer. The adhesive may be any suitable temperature stable adhesive known in the art. Preferably, the adhesive is a permanent acrylic adhesive.

The backing sheet consists essentially of:a backing layer; (ii) an adhesive-release agent on one side of the backing layer; and (iii) a moisture barrier layer on the opposite side of the backing layer.

The paper backing layer may be any suitable paper backing known in the art. The paper layer is preferably of suitable thickness and strength such that the backing sheet can be removed from tie self-adhesive film in one piece. Preferably, the weight of the paper used in the paper layer is between 80 and 170 grams per square metre, most preferably between about 130 to 140 grams per squaru metre.

The adhesive-release agent layer is provided on the side of the paper backing layer which contacts the adhesive layer on the self-adhesive film. The adhesive-release agent layer co-operates with the adhesive layer so that the backing sheet is removably bonded to the self-adhesive film during printing, but can be easily removed when the self-adhesive film is ready to be affixed to an object. Preferably, the adhesive-release agent layer is a silicon based layer.

The moisture barrier layer is bonded to the paper backing layer on the opposite side to the adhesive-release agent layer. The moisture barrier layer is essential to enable the multilayered printable sheet structure to be printed upon in a laser printer or photocopier without deforming. By preventing moisture loss from the sheet structure subjected to the high temperatures of the printing machine, water loss from the sheet structure is minimized and thus curling of the sheet structure is WO 92/21119 PCT/AU92/00218 5 thereby limited. This enables the products to remain flat which is critical during the laser printing operation.

Moreover, the moisture barrier layer gives the multilayered printable sheet structure stability against variations in humidity or temperature. The moisture barrier layer may be formed from any suitable moisture resistant compound as polyvinylid n, c.loride, polyethylene, chlorinated vinyl-acrylate co-polymer. In a preferred embodiment, the moisture barrier layer comprises a PVDC emulsion comprising water, polyvinylidene chloride and one or more wetting agents. In a most preferred embodiment, the moisture barrier layer is applied to the paper backing layer as an emulsion which comprises about water, 28% PVDC and about 2% wetting agents. A suitable PVDC emulsion is Kuroform 193 D (recognized trade mark). Suitable wetting agents are Surfynol S.E. and Antarox LF222 (both recognized trade marks).

The invention will now be described in more detail with reference to the following example. It is to be understood that the example and following description relate to a preferred embodiment only, and is not intended to limit the scope of the present invention.

EXAMPLE

A printable layer is comprised of a vinyl based lacquer with the following additives:- Component Quantity (parts) Vinyl based lacquer 100 Cellulose Titanium dioxide Magnesium oxide The above ingredients are mixed together with high speed stirring and coated onto a vinyl base layer by rotogravure coating. The printable layer is coated at a coating weight of 50 grams per square metre.

WO 92/21119 PC-/A U92!002 i 8 The printable layer and vinyl base layer are then heat fused together. This forms a stable synthetic substrate with a durable surface receptive to all forms of label printing.

A moisture barrier layer is prepared as follows:- Component Quantity (parts) Water 100 .Kuroform 193 D (55% PVDC, 45% water) 100 Surfynol S.E. 2 Antarox LF222 1 The above ingredients are mixed gently to minimize foaming. The resulting emulsion which contains the wetting agents to facilitate smoothness of coating and surface texture is applied either by gravure coating or reverse gravure coating. The emulsion is applied to the paper layer at a coating weight of 10 grams per square metre (dry weight).

The paper weight may be between 80 and 170 grams per square metre. Preferably, the paper weight is 130 grams per square metre. Prior to coating of the paper layer, dilution of the emulsion allows further penetration of the emulsion into the paper.

After coating, the structure is cured in a direct gas fired oven at 60 metres per minute web speed.

The coated vinyl base layer and printable layer and (ii) paper backing layer and moisture barrier layer are then laminated using a permanent acrylic adhesive using a transfer coating method known in the art to achieve the finished product.

It will be appreciated that various modifications, additions and/or alterations may be made to the structure previously described without departing from the ambit of the present invention.

Claims (13)

1. A multilayered printable sheet structure comprising a self-adhesive film consisting of:- a vinyl base layer having a first and second surface; (ii) a printable layer bonded to said first surfact, saii printahlb ]ayci ainclu.ing ons cr more fillers and/or pigments; and (iii) an adhesive layer on said second sur ace; and a backing sheet consisting of:- (iv) a paper backing layer having a first and second surface; an adhesive-release agent layer on said first surface intermediate said paper backing layer and said adhesive layer; and (vi) a moisture barrier layer on said second surface of said backing layer.

2. A multilayvered printable sheet structure according to claim 1 wherein said printable layer includes one or more fillers and/or binders selected from the group consisting of cellulose, poly(vinyl)alcohol, acrylic-based emulsions, poly(vinyl acetate), titanium dioxide, magnesium oxide, calcium carbonate, kaolin clays and silicas.

3. A multilayered printable sheet structure according to claim 1 or 2 wherein the printable layer comprises between 85% to 95% vinyl, 1% to 10% cellulose, 1% to titanium dioxide and 1% to 5% magnesium oxide.

4. A multilayer printable sheet structure according to any one of claims 1 to 3 wherein said printable layer is coated onto said vinyl base layer at a coating weight of grams per square metre.

A multilayered printable sheet structure according to any one of claims 1 to 4 wherein the moisture barrier layer is comprised of polyvinylidene chloride, polyethylene, or chlorinated vinyl-acrylate co-polymer, or a combination thereof.

6. A multilayered printable sheet structure according to claim 5 comprising polyvinylidene chloride and a WO 92/21119 PC'F/AU92/00218 8 wetting agent.

7. A multilayered printable sheet structure according to any one of claims 1 to 6 wherein said paper backirg layer has a mass of between 80 and 173 grams per square metre.

8. A multilayered printable sheet structure according to any one of claims 1 to 7 wherein said sheet structure is capable of being printed upon by xerography.

9. A method of forming a multilayered printable sheet structure comprising the steps of:- coating a mixture of a vinyl-based lacquer and one or more fillers and/or pigments onto a vinyl-base layer; (ii) subjecting said vinyl-based layer and coating mixture to heat to fuse said layer and mixture; (iii) coating a paper layer with a moisture barrier emulsion of polyvinylidene chloride and one or more surfactants and/or wetting agents; (iv) curing said coated paper; applying an adhesive to the vinyl base layer; (vi) applying an adhesive release agent to the uncoated side of coated paper; and (vii) adhering said adhesive to said adhesive release agent.

10. A method according to claim 9 wherein said mixture of vinyl based lacquer and fillers and/or pigments comprises between 85% to 95% by weight of vinyl, between 1% to 10% cellulose, between 1% to 5% by weight of titanium dioxide and between 1% to 5% by weight of magnesium oxide.

11. A method according to claim 9 or 10 wherein said moisture barrier emulsion comprises between 50% to 80% by weight of water, between 20% to 50% by weight of polyvinylidene chloride and between about 1% to 5% by weight of wetting agents.

12. A multilayer printable sheet structure substantially as hereinbefore described with reference to the example.

13. A method substantially as hereinbefore described with reference to the example. International ADDlication No. PCT/AU 92/00218 INTERNATIONAL SEARCH REPORT I. CLASSIFICATION OF SUBJECT MATTER (if several classification symbols apply, indicate all) e According to International Patent classification (IPC) or to both National Classification and IPC Int. Cl.' G09F 3/10 II. FIELDS SEARCHED Minimum Documentation Searched 7 Classification System Classification Symbols IFC GOF- 3/10 Documentation Searched other than Minimum Do urpentation to the xtent that such locuments aro Included in the ields Searched a AU IPC as above III. DOCUMENTS CONSIDERED TO BE RELEVANT Category' Citation of Document, I with indication, where appropriate of the relevant passages 12 Relevant to Claim No 3 A GB,A, 2177373 (CRAIG) 21 January 1987 (21.01.87) A EP,A, 195427 (ZWECKFORM WERK GmbH) 24 September 1986 (24.09.86) A GB,A, 2068833 (KIMBERLY-CLARK CORP) 19 August 1981 (19.08.81) A US,A, 3963851 (TOYODA) 15 June 1976 (15.06.76) S Special categories of cited documents 10 Later document published after the international filing date or priority date end not in conflict Document defining the general state of the art which is with the application but cited to understand the not considered to be of particular relevance principle or theory underlying the invention earlier document but published on or after the document of particular relevance; the claimed international filing date invention cannot be considered novel or cannot be document which may throw doubts on priority claim(s) considered to involve an inventive step or which is cited to establish the publication date of document of particular relevance; the claimed another citation or other special reason (as specified) invention cannot be considered to involve an "O0 document referring to an oral disclosure, use, inventive step when the document is combined exhibition or other means with one or more other such documents, such document published prior t the international filing date combination being obvious to a person skilled in but later than the priority date claimed the art document member of the same patent family IV. CERTIFICATION Date of the Actual Completion of the International Search Date of Mailing of this International Search Report 31 July 1992 (31.07.92) 6 AuQust 1992 (06.08.92) International Searching Authority Signature of Authorized Officer AUSTRALIAN PATENT OFFICE J W THOMSON id^ hor -o Form PCT/IPS/210/ Isecond shelt) (January 19861 ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL APPLICATION NO. PCT/AU 92/00218 This Annex lists the known publication level patent family members relating to the patent documents cited in the above-mentioned international search report. The Australian Patent Office is in no way liable for these particulars which are merely given for the purpose of information. Patent Document Cited in Search Patent Family Member Report EP 195427 DE 8508203 GB 2068833 AU 66692/81 DE 3102850 FR 2475459 IT 8167167 JP 56127446 NL 8100594 US 4398985 US 3963851 DE 2237076 GB 1404018 JP 50029738