CA1282913C - Security paper containing vesiculated beads - Google Patents
Security paper containing vesiculated beadsInfo
- Publication number
- CA1282913C CA1282913C CA000519706A CA519706A CA1282913C CA 1282913 C CA1282913 C CA 1282913C CA 000519706 A CA000519706 A CA 000519706A CA 519706 A CA519706 A CA 519706A CA 1282913 C CA1282913 C CA 1282913C
- Authority
- CA
- Canada
- Prior art keywords
- paper
- security paper
- recited
- beads
- vesiculated beads
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
- D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
- D21H21/40—Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper
- D21H21/44—Latent security elements, i.e. detectable or becoming apparent only by use of special verification or tampering devices or methods
- D21H21/48—Elements suited for physical verification, e.g. by irradiation
Landscapes
- Paper (AREA)
Abstract
SECURITY PAPER CONTAINING
VESICULATED BEADS
ABSTRACT
Security paper contains polymeric vesiculated beads having a volume average particle size of at least about 10 microns up to about 35 microns, these beads containing dye or pigment which glows when irradiated with nonvisible radiation, and being hard to see when the paper is viewed with the naked eye under normal visible light.
VESICULATED BEADS
ABSTRACT
Security paper contains polymeric vesiculated beads having a volume average particle size of at least about 10 microns up to about 35 microns, these beads containing dye or pigment which glows when irradiated with nonvisible radiation, and being hard to see when the paper is viewed with the naked eye under normal visible light.
Description
~2~3~9~3 SECURITY VAPER CONTAINING
~ES I CULATED BEADS
DESCRIPTION
Technical rield This inven-tion relates to security paper containing vesiculated beads which are not visible when viewed by visible light, but which are easily seen when exposed to nonvisible radiation.
Background Art Special papers have been developed for security purposes to help insure that the document is genuine. These papers are illustrated by the use of colored fibers, planchettes, water marks or special dyes. I-t is desired to provide papers which will be 15 more difficult for the counterfeiter to duplicate.
The special character of some of these papers is easily seen by close inspection under ordinary light, so anyone viewing the paper is alerted to the need for using a paper having a special appearance, and it 20 is not too difficult to provide a duplicate paper.
In some instances a special light is needed to see a dye in the paper, but it is still not too difficult to provide a paper containing a comparable concentration of the same dye. It is desired to 25 provide security paper which contains very easily visible identification when viewed by nonvisible light, whereas this identification is not visible when the paper is vlewed under normaL lighting. In this way, one attcmpting to mimic the document may 30 not be alert to the fact that ordinary papcr cannot be usecl~ Moreover, it is clesired to provide paper which is not easily duplicated even when the party attempting to mimic the document is alert to the fact that the paper has a peculiar appearance under 35 nonvisible light.
~ES I CULATED BEADS
DESCRIPTION
Technical rield This inven-tion relates to security paper containing vesiculated beads which are not visible when viewed by visible light, but which are easily seen when exposed to nonvisible radiation.
Background Art Special papers have been developed for security purposes to help insure that the document is genuine. These papers are illustrated by the use of colored fibers, planchettes, water marks or special dyes. I-t is desired to provide papers which will be 15 more difficult for the counterfeiter to duplicate.
The special character of some of these papers is easily seen by close inspection under ordinary light, so anyone viewing the paper is alerted to the need for using a paper having a special appearance, and it 20 is not too difficult to provide a duplicate paper.
In some instances a special light is needed to see a dye in the paper, but it is still not too difficult to provide a paper containing a comparable concentration of the same dye. It is desired to 25 provide security paper which contains very easily visible identification when viewed by nonvisible light, whereas this identification is not visible when the paper is vlewed under normaL lighting. In this way, one attcmpting to mimic the document may 30 not be alert to the fact that ordinary papcr cannot be usecl~ Moreover, it is clesired to provide paper which is not easily duplicated even when the party attempting to mimic the document is alert to the fact that the paper has a peculiar appearance under 35 nonvisible light.
~8Z9~3 23158-1563 It is also important to provide a paper which is economically producible, which is printable, as by enyraving procèsses, without damage, and which can be viewed to insure its genuine nature from either side of the paper.
_sclosure of Invention In accordance with this invention, there is incorporated into the paper furnish, cross-linked, polymeric vesiculated beads havlng transparen-t walls and a volume average particle size of at least about 10 microns, preferably at least 20 microns, up to about 35 microns, and which include pigment or dye which responds to nonvisible radiation, especially to ultraviolet light. These polymeric vesiculated beads are small enough so that they are not visible to the unaided eye, even when these beads are colored when so viewed and incorporated into white paper. ~Iowever, under nonvisible light, these beads glow and provided bright spots (which may have a distinctive coloration or combination of colora-tions) to identify the paper and distinguish it from ordinary paper as well as other special papers having a different density of bright spots and/or spots of different coloration.
In preferred practice, the security paper will contain from 0.1 to 15 weight percent of such beads, preferably from 0.5 to 596 thereof, based on the total weight of the paper. This paper may be calendered or uncalendered.
It is desired to point out that prior security papers are frequently single sided in that the fibers or other identify-ing devices concentrate at the wire side of the paper. In this invention, the beads which are incorporated in the paper become visible under nonvisible liyht at both sides of the BZ9~3 paper, and this eases the burden of examination.
It is stressed that the vesiculated beads under consideration contain many cells and are quite different from ordinary hollow polymer beads in being S load bearing. As a result, these beads can be present in paper which sustains the pressure of the calendering and engraving processes which are involved in the procduction of security papers.
The beads under consideration normally 10 contain an average of at leas-t about 5 cells per bead, preferably at least about 10 cells per bead.
It appears that the presence of a large number of cells in each bead is what allows the bead to avoid collapse when paper containing the same is compressed 15 under the considerable force imposed in the calendering operation.
It is stressed that the beads in this invention have transparent walls, and the multiplicity of cells retroreflects the incident 20 light to produce a very bright spot of emitted light when the paper is appropriately irradiated. It is very difficult to duplicate the brightness of the vesiculated beads using plastic beads of different character. Moreover, the most effective way to 25 provide the beads which are used herein is to incorporate the pigment or dye into the cell walls at the time of their production, and it would be very difficult to add a corresponding coloration after the beads have been Eormed. I-t is unlikely that one 30 attempting to duplicate a security paper woul(l he able to mimic the beads which are used herein.
It is also stressecl tha-t the appearance of invisibility in ordinary light and easy visibility in nonvisible light is an aspect of the fact that the 35 beads are ulliformly distributed throughou-t the body ~28Z9~
of the paper. This uniform distribution of the beads throughout the body of the paper requires that the vesiculated beads be added to the paper furnish. It is found that when the beads are so added, they are effectively retained in the paper as th0 water and some of the fines and mineral filler used in papermaking pass through the Fourdrinier wire in conventional papermaking.
Bead retention can be enhanced when 10 conventional retention aids are employed, though this is not essential. Both anionic and cationic retention aids are useful, but anionic retention aids are more efficient. The vesiculated beads are distributed quite uniformly throughout the paper and, 15 while many of them are buried within the paper so as to be invisible on casual inspection, they will nonetheless pick up nonvisible light and glow in the visible range to provide a bright spot which is easily seen.
The retention aids which have been found to be useful herein are themselves well known, and many are available in commerce. Acrylamide and methacrylamide copolymers with monoethylenic acids or monoethylenic amines are preferred, these generally 25 containing from 5% to 50~ of the acid or amine monorner, balance the amide monomer. Ihe anionic copolymers which are preferred will usually contain acrylic or methacrylic acid as the acid component, and these are rendered anionic with the aid of an 30 amine, which is preferably ammonia. Thus, a copolymer of 20% methacrylic acid with 80% acrylami(le is illustrative of a preferred anionic retention aid.
The cationic amide copolymers are illustrated by copolymers of acrylamide Wit}l diethyl 35 aminoethyl methacrylamide.
~3LZ82~3 Various other anionic and cationic resins which may be used as the retention aid are discussed in the Kirk Othmer "Encyclopedia of Chemical Technology, third edition" Volume 16, at page 804 which points out that the usual fillers having a size up to 5 microns are not effectively retained because they are so small, thus provoking the use of retention aids in the paper furnish. The beads used herein are generally much larger, but their retention 10 on the Fourdrinier wire is enhanced by the conventional retention agents nonetheless.
The preferred vesiculated beads are styrene-cross-linked unsaturated polyester resins.
These are made into a vesiculated bead in 15 conventional fashion, as illustrated by U.S. Pat. No.
_sclosure of Invention In accordance with this invention, there is incorporated into the paper furnish, cross-linked, polymeric vesiculated beads havlng transparen-t walls and a volume average particle size of at least about 10 microns, preferably at least 20 microns, up to about 35 microns, and which include pigment or dye which responds to nonvisible radiation, especially to ultraviolet light. These polymeric vesiculated beads are small enough so that they are not visible to the unaided eye, even when these beads are colored when so viewed and incorporated into white paper. ~Iowever, under nonvisible light, these beads glow and provided bright spots (which may have a distinctive coloration or combination of colora-tions) to identify the paper and distinguish it from ordinary paper as well as other special papers having a different density of bright spots and/or spots of different coloration.
In preferred practice, the security paper will contain from 0.1 to 15 weight percent of such beads, preferably from 0.5 to 596 thereof, based on the total weight of the paper. This paper may be calendered or uncalendered.
It is desired to point out that prior security papers are frequently single sided in that the fibers or other identify-ing devices concentrate at the wire side of the paper. In this invention, the beads which are incorporated in the paper become visible under nonvisible liyht at both sides of the BZ9~3 paper, and this eases the burden of examination.
It is stressed that the vesiculated beads under consideration contain many cells and are quite different from ordinary hollow polymer beads in being S load bearing. As a result, these beads can be present in paper which sustains the pressure of the calendering and engraving processes which are involved in the procduction of security papers.
The beads under consideration normally 10 contain an average of at leas-t about 5 cells per bead, preferably at least about 10 cells per bead.
It appears that the presence of a large number of cells in each bead is what allows the bead to avoid collapse when paper containing the same is compressed 15 under the considerable force imposed in the calendering operation.
It is stressed that the beads in this invention have transparent walls, and the multiplicity of cells retroreflects the incident 20 light to produce a very bright spot of emitted light when the paper is appropriately irradiated. It is very difficult to duplicate the brightness of the vesiculated beads using plastic beads of different character. Moreover, the most effective way to 25 provide the beads which are used herein is to incorporate the pigment or dye into the cell walls at the time of their production, and it would be very difficult to add a corresponding coloration after the beads have been Eormed. I-t is unlikely that one 30 attempting to duplicate a security paper woul(l he able to mimic the beads which are used herein.
It is also stressecl tha-t the appearance of invisibility in ordinary light and easy visibility in nonvisible light is an aspect of the fact that the 35 beads are ulliformly distributed throughou-t the body ~28Z9~
of the paper. This uniform distribution of the beads throughout the body of the paper requires that the vesiculated beads be added to the paper furnish. It is found that when the beads are so added, they are effectively retained in the paper as th0 water and some of the fines and mineral filler used in papermaking pass through the Fourdrinier wire in conventional papermaking.
Bead retention can be enhanced when 10 conventional retention aids are employed, though this is not essential. Both anionic and cationic retention aids are useful, but anionic retention aids are more efficient. The vesiculated beads are distributed quite uniformly throughout the paper and, 15 while many of them are buried within the paper so as to be invisible on casual inspection, they will nonetheless pick up nonvisible light and glow in the visible range to provide a bright spot which is easily seen.
The retention aids which have been found to be useful herein are themselves well known, and many are available in commerce. Acrylamide and methacrylamide copolymers with monoethylenic acids or monoethylenic amines are preferred, these generally 25 containing from 5% to 50~ of the acid or amine monorner, balance the amide monomer. Ihe anionic copolymers which are preferred will usually contain acrylic or methacrylic acid as the acid component, and these are rendered anionic with the aid of an 30 amine, which is preferably ammonia. Thus, a copolymer of 20% methacrylic acid with 80% acrylami(le is illustrative of a preferred anionic retention aid.
The cationic amide copolymers are illustrated by copolymers of acrylamide Wit}l diethyl 35 aminoethyl methacrylamide.
~3LZ82~3 Various other anionic and cationic resins which may be used as the retention aid are discussed in the Kirk Othmer "Encyclopedia of Chemical Technology, third edition" Volume 16, at page 804 which points out that the usual fillers having a size up to 5 microns are not effectively retained because they are so small, thus provoking the use of retention aids in the paper furnish. The beads used herein are generally much larger, but their retention 10 on the Fourdrinier wire is enhanced by the conventional retention agents nonetheless.
The preferred vesiculated beads are styrene-cross-linked unsaturated polyester resins.
These are made into a vesiculated bead in 15 conventional fashion, as illustrated by U.S. Pat. No.
3,879,314. The size of the vesiculated beads under consideration may vary considerably, but is generally larger ~han a volume average oE about 10 microns in diameter. For example, beads having a volume average 20 diameter of from about 10 to about 35 microns are conveniently prepared and fully useful in this invention. As the bead size increases above about 20 microns, they become particularly easy to see when properly exposed, and are thus preferred for use 25 herein.
Various other patents are of interest to the formation of vesiculated beads useEul in this invention, particular attention being directed to U.S. patents Nos. 3,8Z2,22~, 3,923,70~ and 30 3,933,579. This last~namecl patent clescribes the vesiculatecl beads which are preferred herein, namely, those having a ratio of granular diameter to mean vesicle diameter of at least 5:1, a vesicle volulne of Erom 5% to 95% of the volurne oE the granule, and not 35 more than about G0% pigment, by volume.
~X1~2~13 The vesiculated beads used herein have a highly cross-linked polymeric body which is preEerably constituted by a carboxyl-functional unsaturated polyester resin cross-linked with an ethylenically unsaturated monomer copolymerizable therewith. The unsaturation in the polyester is preferably maleate unsaturation, these polyesters being themselves well known and illustrated hereinafter. It is preferred that the polyester have 10 an acid value of 10 to ~5 mgm K0~l per gm.
The unsaturated monomers used for cross-linking are also well known and are water insoluble monomers typically illustrated by styrene or vinyl toluene. The polyesters and monomers are 15 more fully discussed in U.S. Pat. No. 3,879,314 which shows the production of vesiculated beads using a water-soluble polyamine containing at least three amine groups per molecule and having a dissociation constant in water (pKa value) of 8.5-10.5, typically 20 illustrated by diethylene triamine. The polyamine is used in a concentration providing at least 0.3 amine groups per polyester carboxyl group, usually from 0.5 to 1.4 amine groups per polyester carboxyl group. It is preferred to have from 35% to 45% o~ the 25 unsaturated polyester cross-linked with from 55% to 65% of styrene.
The invention is illustrated as follows, it being understood that all parts and proportions are by weight, unless otherwise specified.
30 Example Suitable pigmented vesiculated beads in accordance with this invention are illllstrated in ll.S. Patent No. 3,879,314 issued ~pril 22, 1975, see particularly ~xample II. By proceeding in accordance 35 with said Example II and Usillg a polyester of 18%
~2~2~3 phthalic anhydride, 37~ maleic anhydride and 45%
propylene glycol dissolved in styrene to form a solution containing ~1.8% of the polyester, vesiculated beads pigmented with a pigment which glows when irradiated with ultraviolet light, to contain about 19.0% pigment, by volume, are provided. These beads haYe an average size of about 25 microns and contain an average of more than 10 cells per bead.
These beads are typically incorporated into a 10 paper furnish in wllich 800 pounds per ton of softwood kraft, 1200 pounds per ton of hardwood kraft, 300 pounds per ton of clay, 20 pounds per ton of rosin size, and 30 pounds per ton of alum are mixed into water to a consistency of about 3%~ The pH is 15 adjusted to a pH in the range of ~.5 to 6.5 by the addition of concentrated sulfuric, and this provides the furnish which is modified by the addition of beads in this invention. The above proportions are in pounds per ton of finished paper basis. This furnish 20 is modified to include 4% or 6% of the vesiculated beads and 1.5% of titanium dioxide, anatase, based on solids content and is supplied to the head box by passing the mixture through a valve in which the solids concentration is reduced to 1.5%.
The paper made from this bead-containing furnish had a basis weight in the range of 37 to ~0 pounds per ream, and it was passed through a size press in conventional Eashion and then calendered at either 150 or 900 pounds per llnear inch at a 30 temperature of about 150~. to provide a printable paper. This paper, when viewed with ordinary light, appeared to be an ordinary paper, but when viewed with ultraviole-t light was seen to have glowing spots all over it, like salt scattered on black paper.
Various other patents are of interest to the formation of vesiculated beads useEul in this invention, particular attention being directed to U.S. patents Nos. 3,8Z2,22~, 3,923,70~ and 30 3,933,579. This last~namecl patent clescribes the vesiculatecl beads which are preferred herein, namely, those having a ratio of granular diameter to mean vesicle diameter of at least 5:1, a vesicle volulne of Erom 5% to 95% of the volurne oE the granule, and not 35 more than about G0% pigment, by volume.
~X1~2~13 The vesiculated beads used herein have a highly cross-linked polymeric body which is preEerably constituted by a carboxyl-functional unsaturated polyester resin cross-linked with an ethylenically unsaturated monomer copolymerizable therewith. The unsaturation in the polyester is preferably maleate unsaturation, these polyesters being themselves well known and illustrated hereinafter. It is preferred that the polyester have 10 an acid value of 10 to ~5 mgm K0~l per gm.
The unsaturated monomers used for cross-linking are also well known and are water insoluble monomers typically illustrated by styrene or vinyl toluene. The polyesters and monomers are 15 more fully discussed in U.S. Pat. No. 3,879,314 which shows the production of vesiculated beads using a water-soluble polyamine containing at least three amine groups per molecule and having a dissociation constant in water (pKa value) of 8.5-10.5, typically 20 illustrated by diethylene triamine. The polyamine is used in a concentration providing at least 0.3 amine groups per polyester carboxyl group, usually from 0.5 to 1.4 amine groups per polyester carboxyl group. It is preferred to have from 35% to 45% o~ the 25 unsaturated polyester cross-linked with from 55% to 65% of styrene.
The invention is illustrated as follows, it being understood that all parts and proportions are by weight, unless otherwise specified.
30 Example Suitable pigmented vesiculated beads in accordance with this invention are illllstrated in ll.S. Patent No. 3,879,314 issued ~pril 22, 1975, see particularly ~xample II. By proceeding in accordance 35 with said Example II and Usillg a polyester of 18%
~2~2~3 phthalic anhydride, 37~ maleic anhydride and 45%
propylene glycol dissolved in styrene to form a solution containing ~1.8% of the polyester, vesiculated beads pigmented with a pigment which glows when irradiated with ultraviolet light, to contain about 19.0% pigment, by volume, are provided. These beads haYe an average size of about 25 microns and contain an average of more than 10 cells per bead.
These beads are typically incorporated into a 10 paper furnish in wllich 800 pounds per ton of softwood kraft, 1200 pounds per ton of hardwood kraft, 300 pounds per ton of clay, 20 pounds per ton of rosin size, and 30 pounds per ton of alum are mixed into water to a consistency of about 3%~ The pH is 15 adjusted to a pH in the range of ~.5 to 6.5 by the addition of concentrated sulfuric, and this provides the furnish which is modified by the addition of beads in this invention. The above proportions are in pounds per ton of finished paper basis. This furnish 20 is modified to include 4% or 6% of the vesiculated beads and 1.5% of titanium dioxide, anatase, based on solids content and is supplied to the head box by passing the mixture through a valve in which the solids concentration is reduced to 1.5%.
The paper made from this bead-containing furnish had a basis weight in the range of 37 to ~0 pounds per ream, and it was passed through a size press in conventional Eashion and then calendered at either 150 or 900 pounds per llnear inch at a 30 temperature of about 150~. to provide a printable paper. This paper, when viewed with ordinary light, appeared to be an ordinary paper, but when viewed with ultraviole-t light was seen to have glowing spots all over it, like salt scattered on black paper.
Claims (12)
1. A security paper containing cross-linked, polymeric vesiculated beads having transparent walls and a volume average particle size of at least about 10 microns up to about 35 microns, said vesiculated beads containing dye or pigment which glows when irradiated with nonvisible radiation, and said vesiculated beads being hard to see when the paper is viewed with the naked eye under normal visible light.
2. A security paper as recited in claim 1 in which said vesiculated beads have a volume average particle size of at least about 20 microns.
3. A security paper as recited in claim 1 in which said vesiculated beads are present in an amount of from 0.1 to 15%.
4. A security paper as recited in claim 3 in which said vesiculated beads contain an average of at least 5 cells per bead.
5. A security paper as recited in claim 4 in which said vesiculated beads have a ratio of granular diameter to mean vesicle diameter of at least 5:1, a vesicle volume of from 5% to 95% of the volume of the granule, and not more than about 60%
pigment, by volume.
pigment, by volume.
6. A security paper as recited in claim 1 in which said vesiculated beads are incorporated in the furnish to be relatively uniformly distributed throughout the body of the paper.
7. A security paper as recited in claim 6 in which said paper is calendered.
8. A security paper as recited in claim 6 in which the polymeric body of said beads is constituted by a carboxyl-functional unsaturated polyester resin cross-linked by an ethylenically unsaturated monomer copolymerizable therewith.
9. A security paper as recited in claim 8 in which said polyester contains maleate unsaturation and is cross-linked with styrene.
10. A security paper as recited in claim 9 in which from 35% to 45% of unsaturated polyester is cross-linked with from 55%
to 65% of styrene.
to 65% of styrene.
11. A security paper as recited in claim 1 in which said pigment or dye is associated with the walls of said cells.
12. A security paper as recited in claim 11 in which said vesiculated beads are present in an amount of from 0.5% to 5%.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US78462085A | 1985-10-04 | 1985-10-04 | |
| US784,620 | 1985-10-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1282913C true CA1282913C (en) | 1991-04-16 |
Family
ID=25133025
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000519706A Expired - Fee Related CA1282913C (en) | 1985-10-04 | 1986-10-03 | Security paper containing vesiculated beads |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0219743A1 (en) |
| CA (1) | CA1282913C (en) |
| FI (1) | FI864014A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0226367B1 (en) * | 1985-12-05 | 1990-02-28 | The Wiggins Teape Group Limited | Security paper |
| JP3978961B2 (en) * | 1998-12-25 | 2007-09-19 | 特種製紙株式会社 | Fluorescent coloring particles used for anti-counterfeit paper, manufacturing method thereof, and anti-counterfeit paper using fluorescent coloring particles |
| EP1342768A1 (en) * | 2000-11-22 | 2003-09-10 | Tokushu Paper Manufacturing Co. Ltd | Particles emitting fluorescence by irradiation of infrared ray and forgery preventing paper using the same |
| US20020066543A1 (en) * | 2000-12-05 | 2002-06-06 | Spectra Systems Corporation | Fluorescent micro-particles embedded in a pigmented fluorescent coating for optical document security |
| DE10116315A1 (en) | 2001-04-02 | 2002-10-10 | Giesecke & Devrient Gmbh | Color coding for marking objects |
| DE10322841A1 (en) | 2003-05-19 | 2004-12-16 | Merck Patent Gmbh | Dual security feature |
| FR2868093B1 (en) * | 2004-03-26 | 2007-07-13 | Honnorat Rech S & Services Sar | LAYER SAFETY PAPER |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3933579A (en) * | 1968-11-28 | 1976-01-20 | Dulux Australia Limited | Vesiculated polymer granules |
| DE2443164C2 (en) * | 1974-09-10 | 1976-09-02 | Hoechst Ag | THERMOPLASTIC PLASTIC FILM WITH RADIATION CHANGING PARTICLES |
| FR2478695A1 (en) * | 1980-03-21 | 1981-09-25 | Aussedat Rey | Security paper incorporating dispersed luminescent particles - visible only in UV light, prepd. by adding particles suspension to finished pulp |
-
1986
- 1986-10-02 EP EP86113634A patent/EP0219743A1/en not_active Withdrawn
- 1986-10-03 FI FI864014A patent/FI864014A/en not_active Application Discontinuation
- 1986-10-03 CA CA000519706A patent/CA1282913C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| FI864014A0 (en) | 1986-10-03 |
| EP0219743A1 (en) | 1987-04-29 |
| FI864014A (en) | 1987-04-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |