GB2189895A

GB2189895A - Photosensitive recording medium comprising microcapsules

Info

Publication number: GB2189895A
Application number: GB08707847A
Authority: GB
Inventors: Jun Sakai
Original assignee: Brother Industries Ltd
Current assignee: Brother Industries Ltd
Priority date: 1986-04-02
Filing date: 1987-04-02
Publication date: 1987-11-04
Also published as: FR2596881A1; GB8707847D0; DE3710578A1; JPS62232638A

Description

GB2189895A 1 SPECIFICATION medium to change color. More particularly a

desired color is developed on the developing Photo and pressure sensitive recording me- medium, thus forming a color image corre dia sponding to a manuscript.

70 With the modified embodiment, a first com This invention relates to a photo and pressure ponent released from ruptured microcapsules sensitive recording medium capable of record- reacts with a second component which is ing an image by using visible light and/or in- coated on the supporting member to develop frared light. a color in accordance with the exposed image A photo and pressure sensitive medium 75 on the recording medium.

capable of recording an image by using ultra- The invention will be further described by violet rays has been proposed as disclosed in way of non-limitative example with reference the United States Patent Specification Nos. to the accompanying drawings, in which:

4399209 and 4440846. Fig. 1 is an enlarged partial sectional view However, ultraviolet rays are harmful to hu- 80 showing a first embodiment of this invention; man bodies so that when using such photo Fig. 2 is a diagrammatic representation and pressure sensitive recording medium it is showing an exposure step; necessary to use a complicated mechanism Fig. 3 is a diagram showing the step of that can prevent leakage of the ultraviolet rupturing the microcapsules; rays. 85 Fig. 4 is an enlarged partial sectional view Accordingly, it is an object of this invention showing a second embodiment of this inven to provide an improved photo and pressure tion; and sensitive recording medium not requiring a Fig. 5 is a diagram showing the step of complicated mechanism for preventing leakage rupturing the microcapsule.

of ultraviolet rays. 90 As shown in Fig. 1, a plurality of spherical According to this invention there is provided microcapsules 2 are juxtaposed on the surface a photo- and pressure-sensitive recording me- of a supporting member la made e.g. of pa dium comprising a sheet shaped supporting per, which comprises a photo and pressure member; and microcapsules coated on one recording medium 1. Each capsule 2 comsurface of said supporting member and con- 95 prises a hollow spherical shell 2a and a liquid taining a first component which changes its component 2b enveloped therein. The liquid color or optical density or reflectivity when it component 2b contains a dye precursor that reacts with a second component and a third reacts with a chromogenic material to develop component which changes the mechanical a color, and a photo-curable substance that strength of said microcapsules when irradiated 100 hardens when irradiated with infrared rays.

with visible and/or infrared light. The walls of the microcapsules are, of course, According to a modification of this inven- of a material which permits visible or infrared tion, there is provided a photo- and pressurelight to which the component 2b reacts to sensitive recording medium comprising; enter the capsule and impinge on the compo- a sheet shaped supporting member; 105 nent 2b.

a plurality of microcapsules containing a first As the dye precursor can be used a triallyl component and coated on one surface of said methane component, a bisphenyl methane supporting member; and compound, a Xanthene compound, a thiazine a second component coated on said sup- compound, a spiropyrane compound and mix- porting member end reacts with said first 110 tures thereof. The chromogenic material component for changing color or optical den- causes the dye precursor to develop a special sity or reflectivity of said one surface of said color. Clay, organic acids, an acidec polymer, supporting member; metal salts, aromonic carboxylic acids and said microcapsules containing a third com- mixture thereof can be used as the chromo ponent which changes mechanical strength of 115 genic material. As the photo-curable substance said microcapsules on exposure to visible an- may be used a photo- polymerizing substance d/or infrared light. including ethylene type unsaturated com With the first embodiment, only portions of pounds, trimethytal propane, for example an the microcapsules exposed to visible or infra- acrylate prepolymer, or the like. These com red light change their mechanical strength 120 pounds are used in combination with a photo against rupture. That is, the mechanical polymerizing initiator which is used for initiat strength of the microcapsules exposed to light ing polynerization of the resin in response to increases or decreases. As a consequence infrared rays, and may comprise such organic when the recording medium is passed be- or inorganic peracid compounds as diacyl per tween pressure applying rollers, only the mi- 125 oxide, kentone peroxide, arkyl peroxide, arkyl crocapsules whose strength is decreased or hydroperoxide, sulphonyl peroxide, peroxydi not increased are ruptured so that the compo- carabonate, etc.

nent therein flows to the outside. The re- The microcapsules can be prepared by such leased component reacts with another compo- well known techniques as the core celivation nent which is coated on a separate developing 130 method and the interface polymerization 2 GB2189895A 2 method and contains therein the dye precursor Just like the recording medium 1 described and the photo-curable substance. above, this recording medium 20 too can re A binder, a filler, a viscosity adjusting agent cord an image in the same manner as shown or the like are added to the microcapsules and in Fig. 2. Then as shown in Fig. 5 the cap theresulting mixture is coated on the support- 70 sules are ruptured by the rollers 26. The hard ing member with a coating roller, a spray or a ened microcapsules h20 would not be rup doctor knife. tured because their mechanical strength has Any image can be recorded on a photo and been increased by internal hardening when pressure sensitive recording medium 1 formed they pass through the rollers 26. On the other by a method as shown in Fig. 2. When infra- 75 hand microcapsules s20 not exposed to light red ray is projected onto the recording me- and hence not hardened would be ruptured so dium 1 through a manuscript 10 from a that their internal component leaks to the out source of infrared light, not shown, the in- side. Since each microcapsule is enveloping terior of the microcapsules 2 on the recording therein a dye precursor that reacts with the medium 1 are caused to harden by the infra- 80 chromogenic material 22 carried by the sup red rays passing through portion other than porting member 20a for developing color, por opaque portions 10a such as pigment on the tions not exposed to light develop color, manuscript 10 whereby the mechanical these producing the image of the manuscript strengths against rupture increases. Among on the recording medium 20.

the microcapsules 2 those designed by sl are 85 Although in the foregoing embodiments co not irradiated with the infrared rays, so that lors are developed by the reaction between they are not hardened. On the other hand mi- the dye precursor and the chromogenic ma crocapsules hl are caused to harden by the terial, when a first component in each micro irradiated rays. capsule comprises a bleaching agent having Then, as illustrated in Fig. 3, the recording 90 oxydation-reduction performance or such a demedium 1 and a developing medium 16 1 colorizing agent as a sensitivity decreasing coated with the chromogenic material 14 ther- agent that separates the dye precursor from eon are superposed and passed between rol- the chromogenic material and where a second lers 18 so as to rupture the unhardened mi- component comprises a dye which is deco- crocapsules st However, hardened microcap- 95 lored by the first component, it is possible to sules hl would not be ruptured by the rollers produce the image of the manuscript by 18 because their mechanical strength has changing the hue, brightness and saturation by been increased by hardening. decolorization.

On the other hand, microcapsules sl envel- Further, instead of forming the image by oped a dye precursor which reacts with the 100 passing the infrared light through the manu chromogenic material carried by the develop- script above, images can be formed on the ing medium 16 corresponding to portions of recording media 1 and 20 by directly project the recording medium 1 where microcapsules ing visible or infrared laser beam thereon.

are ruptured develop color thus fixing the im- Moreover, instead of the photo-curable sub- age of the manuscript 10 on the developing 105 stance, a photo-softenable substance such as medium 16. 3-oxyamino-butanon methacrylate which In the above embodiment, the developing senses a visible light may be enveloped in medium 16 comprises a paper but the other each microcapsule. In this case, microcapsules materials such as a cloth and a vinyl film can irradiated with light are softened while notbe adopted. Thus, with the above embodi- 110 irradiated microcapsules remain their hardness, ment, desired patterns can be printed on vari- and thus the negative image of the manuscript ous subjects including dress materials, hand- can be formed on the recording medium or on kerchives, post cards and so on. the developing medium by applying the pres A second embodiment of this invention will sure thereon.

be described with reference to Figs. 4 and 5, 115 Since the photo and pressure sensitive re in which Fig. 4 is an enlarged sectional view cording medium of this invention is con showing a portion of a photo and pressure structed as above, a desired image can be sensitive recording medium 20. More particu- formed by light exposure without using ultra larly, the surface of a supporting member 20a violet rays. For this reason, when using the made of paper is coated with a layer of a 120 photo and pressure sensitive recording me chromogenic material 22, and microcapsules dium of this invention, it is not necessary to 24 are coated on the layer 22 of the chromo- use a complicated mechanism for preventing genic material 22. Like the microcapsule 2 of leakage of ultraviolet rays.

the previous embodiment, each microcapsule

Claims

24 comprises an outer shell 24a and a liquid 125 CLAIMS component

enveloped therein. The liquid com- 1. A photo- and pressure- sensitive recording ponent 24b consists of a dye precursor that medium comprising a sheet shaped supporting reacts with the chromogenic material to demember; and microcapsules coated on one velop color and a photo-curable substance surface of said supporting member and con- which hardens in response to infrared rays. 130 taining a first component which changes its 3 GB2189895A 3 color or optical density or reflectivity when it claim 10 wherein said microcapsules are reacts with a second component and a third coated on said second component laid on said component which changes the mechanical supporting member.

strength of said microcapsules when irradiated 12. The recording medium according to with visible and/or infrared light. 70 claim 11 wherein said second component 2. The recording medium according to claim comprises a chromogenic materials.

1 wherein each of said microcapsules com- 13. The recording medium according to prises a hollow outer shell, said first compo- claim 10 wherein each microcapsule com nent comprise a dye precursor that reacts prises a hollow outer shell and a liquid com- with a chromogenic material for developing 75 ponent enveloped therein, said liquid compo color and said third component comprises a nent containing a dye precursor that develop photo-curable substance which hardens in re- color by reacting with a chromogenic material, sponse to said light. and a photo-curable hardened by infrared light.

3. The recording medium according to claim 14. A recording medium substantially as 2 wherein said precursor a triallyimethane 80 hereinbefore described with reference to and component, a bisphenyl methane compound, a as illustrated in Figures 1 to 3 or Figures 4 xanthene compound, a thiazine compound, a and 5 of the accompanying drawings.

spiropyrane compound, or a mixture thereof. 15. A method of recording an image using 4. The recording medium according to claim a recording medium according to any one of 2 wherein said chromogenic material is clay, 85 the preceding claims comprising exposing said organic acids, an acidic polymer, metal salts, one surface of the recording medium to visible aromatic carboxylic acids or a mixture thereof. or infrared light modulated in accordance with 5. The recording medium according to claim the image to be recorded, so as to cause 2 wherein said photo-curable substance is differences in mechanical strengths in the mi photo-polymerizable resin and wherein said 90 crocapsules in accordance with their expo substance is incorporated with a polymerizat- sures to the light and thereafter subjecting the ing consisting of organic or inorganic peroxide microcapsules to pressure to cause differential with a polymerization initiating agent consist- rupturing of microcapsules.

ing of organic or inorganic peroxide. Printed for Her Majesty's Stationery Office 6. The recording medium according to any by Burgess & Son (Abingdon) Ltd, Dd 8991685, 1987.

one of claims 1 to 5 wherein said first com- Published at The Patent Office, 25 Southampton Buildings, ponent is a decolorizing agent and said sec- London, WC2A 1 AY, from which copies may be obtained.

ond component is a dye which is separated into a dye precursor and a chromogenic ma- terial with said decolorizing agent.

7. The recording medium according to any one of claims 1 to 5 wherein said first component is a bleaching agent having oxidation reduction performance and said second com- ponent is a dye which is decolorized with said bleaching agent.

8. The recording medium according to any one of the preceding claims wherein said third component comprises a photo-softenable sub- stance which is softened in response to said light.

9. The recording medium according to claim 8 wherein said photo-softenable substance is 3-oxyamino-butanon methacrylate.

10. A photo- and pressure-sensitive record ing medium comprising; a sheet shaped supporting member; a plurality of microcapsules containing a first component and coated on one surface of said supporting member; and a second component coated on said supporting member and reacts with said first component for changing color or optical density or reflectivity of said one surface of said supporting member; said microcapsules containing a third component which changes mechanical strength of said microcapsules on exposure to visible and/or infrared light.

11. The recording medium according to