FI109190B - Latent image receiving sheet - Google Patents

Abstract

A latent image receiving sheet comprises a substrate bearing microcapsules having walls of a nonmeltable polymer which is a thermosetting aminoplast resin. The walls of the microcapsules have an elongation less than 1%, and the image receiving sheet and microcapsules are resistant to heat. Surprisingly, the latent image receiving sheet capsules nonetheless rupture upon application to the record material of a point source energy input or pulse comprising a DELTA T of at least 115 DEG C per one millisecond. The latent image receiving sheet may be an ink transfer sheet or print plate, a gravure sheet, a cryptic message receiving sheet or an imageable sheet.

Description

109190

LATENT PICTURE RECEIVING SHEET

This invention relates to a sheet for receiving a latent image.

Recording media systems are well known in the art and have been described in many patents, such as U.S. Patents 3,539,375, 3,674,535, 3,746,675, 4,151,748, 4,181,771, 4,246,318 and 4,470,057, which may be referred to for detailed information. In thermosensitive systems, the basic chromogenic agent and the acidic color developer are contained in a coating on the substrate which, when heated to a suitable temperature, melts or softens, thereby allowing a color reaction to occur between the substances.

U.S. Patent 4,529,681 discloses a photosensitive and heat-sensitive recording material using permeable capsules in which the penetration of a color forming component through a thermoplastic capsule wall is achieved by heat.

It is an object of the present invention to provide a latent image receiving sheet using non-fusible microcapsules.

According to a first aspect of the invention there is provided a latent image receiving sheet comprising a substrate containing microcapsules containing a core material, characterized in that the walls of the 30 (a) microcapsules are of non-meltable polymer. with an elongation not exceeding 1% and prepared by in situ polymerisation in aqueous medium from resins selected from melamine and formaldehyde, methylol ··· 35 melamine, or methylated methylol melamine, whereby polymerization is carried out at least 65 ° C, at about 75 ° C; 2 109190 (b) the microcapsules are heat resistant, such that they do not become substantially permeable when placed in an oven at 150 ° C for 1 minute; however, microcapsules are breakable when subjected to a point energy amount comprising at least 115 ° C ΔΤ: η per millisecond, preferably at least 145 ° C per millisecond; 10 provided that the sheet receiving the latent image does not contain complementary reactive imaging reagents on the same surface of the sheet.

The invention also relates to the use of a latent image receiving sheet 15 in a thermal embossing process and to a latent image forming method itself.

The latent pattern receiving sheet may form a variety of inexpensive products to mention: 20 a) Color transfer sheet or printing plate In this embodiment, the microcapsules contain a dye, ink, pigment or dye precursor.

· ,! The latent pattern is recorded by applying a point: energy or energy pulse comprising at least 115 ° C δΤ per millisecond. The sheet is then pressed against another sheet to make it appear * t ·. ·. pattern shift corresponding to them with latency image->.! 30 sheets of capsules broken by a point energy pulse. In one alternative, sublimation dyes can be used and the latent image transferred after capsule breaking '' by heating the latent image sheet to transfer dyes ... · to another sheet.

35 "*. B) Inexpensive Gravure Printing Type Sheet 3 109190 In this embodiment, the microcapsules contain a low boiling or high vapor pressure solvent or gas. When a latent image receiving sheet is subjected to a point energy or energy pulse comprising 5 at least 115 ° C δ , yields a sheet having a selective region of broken capsules. The broken capsule defines a latent pattern. Over time, the contents of the broken capsules evaporate leaving a cheap gravure type sheet. The sheet can be | 10 toned to form ink capsules. the other receiving sheet is pressed against the receiving sheet to transfer to it the pattern corresponding to the broken capsules.

C) Cryptographic sheet In this embodiment, the microcapsules contain a low boiling or high vapor pressure solvent, or gas, as in b) above. Applying a point energy or energy pulse comprising at least 115 ° C δΤ: π in one millisecond to the receiving sheet of the latent image 20 results in a sheet having a selective region of broken capsules. As in (b), this selective region forms a latent image which may be I '·'; 25 selectively according to a predetermined pattern. The pattern can be developed by applying toner particles, such as xerographic toners ("toners") to the sheet. These selectively attach to broken capsule sites.

D) sheet to be patterned In this embodiment, the microcapsules contain either a chromo '* gene or a developer. Applying a latent image receiving> '·, · sheet to a point energy or energy pulse 35 comprising at least 115 ° C δΤ: π in one millisecond results in a sheet having a selective region or pattern of broken capsules. The broken capsules define the latency a · 4 109190 image. The image may be rendered visible by applying to the receiving sheet of the latent image a solvent or dispersion containing either a chromogen or a developer, whichever is not included in the contents of the capsule.

5

The invention will now be described with particular reference to the new capsules of the invention.

The latent image receiving sheet of the invention comprises 10 substrates having microcapsules having walls selected from a non-melting or thermosetting resin. The walls of the microcapsules are selected so that their elongation does not exceed 1%. Unexpectedly, the non-melting walls of microcapsules break when subjected to 15 point energy comprising at least 115 ° C ΔΤ: η in milliseconds.

On the receiving sheet of the latent image are attached microcapsules, the walls of which are heat-curing or 20 non-meltable resins with an elongation not substantially greater than 1%. The thermosetting resin is selected from the preferred methylated methylol melamine, or combinations of melamine and formaldehyde, or methylol melamine polymerized at a temperature of at least 65 ° C, preferably about 75 ° C: 25 °, or urea and formaldehyde, dimethyl, or methylated dimethylol urea, wherein the molar ratio of formaldehyde to urea is 1.9: 1 to 2.1: 1, preferably 2: 1. Table 1 shows the elongations of the various resins. Some of the urea may be replaced by a hydroxy-substituted phenol such as resorcinol. The microcapsule walls are non-meltable.

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Applying a point energy amount of at least 115 ° C, ·, ΔΤ: η ("temperature change") in one millisecond to the sheet receiving the latent image breaks the capsules, which is theoretically believed to be due to the resulting stresses.

5 109190

The microcapsules may contain any substance conventionally used in microcapsulation. They may be combinations of a solvent, a hydrophobic or hydrophilic substance, a liquid, preferably a hydrophobic liquid, a gas, a developer or a chromogen, inks, dyes, tinters or pigments.

The novel microcapsule sheet of the invention has various new uses. When applied to a sheet of microcapsules, a point energy amount of at least 115 ° C ΔΤ: η in milliseconds breaks the microcapsules.

Although the characteristics of microcapsules and sheet material are described with respect to a point energy source such as a thermal print head, it is clear that such recording material or image receiving sheet can also be patterned on a larger device such as a rapidly heating block or multiple thermal print heads assembled. The dot-like sources of the invention may consist of a thermal print head, a laser, a focused hot jet, a heated needle, and the like. The ability to provide a temperature change of at least 115 ° C in one millisecond to the surface of the receiving sheet is required to cause an unusual breakage of the meltable capsules of the invention. However, the invention described herein is not limited to this> · theory, as other mechanisms may affect the phenomenon.

* '30

When aligning the sheet with a suitable δ sop as a selective pattern 1. * V-latent pattern is recorded on the sheet by breaking of the microcapsules, which can be illustrated; a set of closed bottles, of which, however, ____; The component 35 is selectively broken so that it has open ends and thus becomes open containers. A suitable developer can be applied to the surface of the sheet by conventional means such as sponging, spraying, cotton swab or other applicator to produce an image. Alternatively, if a hydrophobic agent is applied to the capsule, the hydrophobic ink or dye applied to the surface of the sheet will selectively adhere to the hydrophobic agent to produce an image.

Unlike prior art capsules, the capsules of the latent image receiving sheet of the invention do not melt or become porous, but instead are broken by rapid thermal decay or energy supply.

If the microcapsules are designed to contain a hydrophobic substance, the hydrophobic ink may be applied to the sheet pin 15 after the latent image is stored on the receiving sheet with a thermal print head, thereby selectively adhering to the capsules whose ends are broken to expose the hydrophobic material. granulated or wiped off the surface of the sheet. Similarly, the hydrophilic agent 20 may be encapsulated for use with hydrophilic dyes. The result is a cheap gravure printing plate or transfer sheet. Alternatively, the ink or dye may be encapsulated in capsules of a similar transfer sheet. form.

25

In the case of use as a printing plate, the substrate is typically selected from "·" 'a more rigid material or also from a synthetic material to improve durability.

k i i 1, · '· 30 The latent image receiving sheet can be used as an optical storage medium, such as to store digitalized information with a laser or thermal print head.

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_ · T The sheet that receives the latent image can also be used * · t * ·; 35 in latent form. This way you can * 'transfer the heat generated head print to encrypted-

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7 109190 na. The latent image can then be developed as described above.

Unlike prior art capsules, the capsule receiving sheet of the latent image of the invention do not melt or become porous when applied to energy, but instead are broken by a rapid change in temperature or by an energy supply such as an energy pulse. Applying energy to the receiving sheet, e.g., with a thermal print head 10 or other source capable of providing a suitable AT, breaks the microcapsules and thus encodes a latent pattern.

Unlike prior art capsules, the capsules of the recording material of the invention do not melt when exposed to energy, but rather are disrupted by a rapid temperature change or energy supply. This has resulted in a significant new material that is heat resistant. It is surprising that the latent image receiving material of the invention can be placed in a hot oven (150 ° C) for substantial periods of time, such as minutes, without becoming permeable to the capsules. Conventional thermal paper, on the other hand, is textured in the oven almost immediately.

The insulation properties of the wall material and the phase change! '! The absence of conduction heat loss appears to result in a high concentration of energy in the contact area between the point source and the capsule '· * *.

* The elongation value of the wall material of the microcapsules with the various resins v · 30 is obtained from the tables. The published values correlate well with the observed phenomena and provide a suitable means for selecting suitable resins. Resins selected as wall materials having an elongation value of no more than 1% lead to microcapsules having non-meltable polymer; 35 wall cladding, or wall materials that have unusual breaking properties due to the resulting thermal stresses.

t! »4 8 109190

Table 1 shows the elongation values for some resins.

TABLE 1

Resin Elongation (%) 5 Acetal 60-75 Acrylic 20-50 I Cellulose 5-100 Fluorocarbon 80-400 Ionomers 100-600 10 Polyamides 25-300 Polycarbonates 60-100 Polyethenes 5-900 Polypropylenes 3-700 Polystyrenes 1-140 15 Vinyls 2-400 epoxies 1-70 phenols 1-2 phenol formaldehyde 0.4-2 melamine formaldehyde 0.6-1.0 20 polyester 40-300 polyester alkyd 0.5-2 silicone 100 urea formaldehyde 0.5 urethane 300-1000 25 nylon 300

The elongation of the polymer shell or wall is defined by the invention; · “For stretching purposes for polymerized bulk resins

i of butter (%) measured by standard tests such as ASTM

V · 30 Test Method D638.

More suitably, elongation values (%) for various resins are available from a variety of sources, e.g., Principles of Polymer Sys- / tems, 2nd Edition, Ferdinand Rodriguez, Cornell University, '35, Hemisphere Publishing Corporation (1970), pages 532-537. The elongation values of the bulk material have correlated 9,109,190 surprisingly well as a predictor of preferred resins in the invention.

Instead of melting, plasticizing with other molten materials, or increasing their permeability due to phase change, the capsule walls of the invention appear to be broken. Breakage of the capsule wall seems to be due to the high temperature gradient and discontinuous heat transfer. Such conditions create local thermal stresses. The amount of strain depends on the properties of the material. A brittle wall does not tolerate much stress and is easily broken.

Stretching properties appear to correlate well with 15 brittleness of the wall, which facilitates resin selection.

The capsules of the invention are surprisingly shattered when exposed to a point energy comprising a temperature change (δΤ) of at least 115 ° C per millisecond.

20 δΤ can be calculated from the following formula: S = E α (T - T0); <i * i 25 where S is the stress E is the modulus of elasticity, a is the linear thermal expansion coefficient

In the previous formula, δΤ is T-T0. The strain S is melaminefor V '30 for maldehyde polymers from 5x103 psi to 13x103 psi and phenol formaldehyde polymers from about 5x103 psi to about 9x103 psi.

J To calculate the lower usable point energy supply

Therefore, (5x10 3) psi is taken. The modulus of elasticity is about (11x105) -. (14x105) psi. Thus, in the lower region, E is taken as 11x105.

'; 35 The linear coefficient of thermal expansion is (4x105) ° C.

Thus, 5x103 = (11x105) (4x105) (T-T0) 10109190 (T-T0) = δΤ = 113.6 ° C, or about 115 ° C per millisecond.

The threshold ΔΤ calculated by this method is about 115 ° C.

5

Another method for accessing iT is based on the data derived from Example 1. Example 1 shows that! the surface temperature of the recording system when using a standard fax machine such as the Canon Fax 230 is higher than 170 ° C.

| 10 This is the temperature that the surface of the paper or medium experiences. The temperature of the thermal print head is higher, but the temperature observed on the surface of the medium alone is relevant to the thermal stresses placed on the capsules on the paper surface.

15

The room temperature is about 25 ° C and should be subtracted from the measured temperature: 170 ° C to 25 ° C = 145 ° C. Based on the amount of dye present, the breakdown AT was calculated to be at least about 115 ° C per millisecond, but preferably at 145 ° C per millisecond.

Because of their non-melting or thermosetting nature, the capsules have no latent thermal capacity and do not undergo any substantial phase change.

25 ,,! In the examples, a thermal printhead was used which broke the capsules of the recording system, as could be seen by a scanning electron microscope.

· ', * ·' 30 The core material of the capsules may contain inks, colorants, chromogens, solvents, gases, liquids and pigments.

The core material of the capsule can be selected relatively independently.

The core can be any substance that is substantially · · insoluble in water. A comprehensive list of nuclear materials can be found in »· * '* | 35 U.S. Patent 4,001,140, which is incorporated herein by reference. The core material can be any material that •: can be dispersed in water and surrounded by 4 · 11 109190 wall materials. It may include air. As a more specific example of a preferred core material, microcapsules may be formulated with an imaging agent such as chromogen, dye, toner or pigment, or the like. Core 5 may be selected from colorless electron donor compounds, dye precursors, or chromogens that form a color upon reaction with the developer. Representative examples of such compounds are the substantially colorless compounds having a lactone, lactam, sulfone, spiropyran, ester, or amino structure on the subframe, such as triarylmethane compounds, bisphenylmethane compounds, xanthene compounds, fluoranes, thiazine compounds, .

Electron donating dye precursors suitable for use in color formation systems, which are chromogenic compounds such as phthalide, leucuramine and fluorane compounds, are well known. Examples of chromogens include crystal violet lactone (3,3-bis (4-20 dimethylaminophenyl) -6-dimethylaminophthalide, U.S. Patent Re. 23,024); phenyl, indole, pyrrole and carbazole-substituted phthalides (e.g., U.S. Patents 3,491,111, 3,491,112, 3,491,116, 3,509,174); nitro, amino, amido, sulfonamido, aminobenzylidene, halo, anilino-substituted fluoranes (e.g., U.S. Patents 3,624,107, 3,627,787, 3,641,011, 3,642,828, 3,681,390); spirodipyrans (U.S. Patent t '3,971,808); and pyridine and pyrazine compounds (e.g., U.S. Patent Nos. 3,775,424, 3,971,808); and pyridine and pyrazine compounds (e.g., U.S. Patents 3,775,424 and 3,853,869).

Other particularly suitable chromogenic compounds include, but are not limited to, the following: 3-diethylamino-6-methyl-7-anilino-fluorane (U.S. Pat.

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; ; '; No. 3,681,390); 2-anilino-3-methyl-6-dibutylamino-fluorane, (U.S. Patent 4,510,513), also known as 3-, 3'-dibutylamino-6-methyl-7-anilino-fluorane; 3-dibutylamino-7- (2-chloroanilino) fluorane; 3- (N-ethyl-N-tetrahydro-hydrofurfuryyliamino) -6-methyl-7-3-5'6 tris (di-methyl

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12 109190 amino) spiro [9 H -fluorene-9'1 (3H) -isobenzofuran] -3'-one; 7- (1-ethyl-2-methylindol-3-yl) -7- (4-diethylamino-2-ethoxyphenyl) -5,7-dihydrofuro [3,4-b] pyridin-5-one (U.S. Patent 4,246,318). ); 3-diethylamino-7- (2-chloroanilino) -5-fluorane (U.S. Patent 3,920, 510); 3- (N-methylcyclohexylamino) -6-methyl-7-anilino-fluorane (U.S. Pat. No. 3,959,571); 7- (1-octyl-2-methylindol-3-yl) -7- (4-diethylamino-2-ethoxyphenyl-5,7-dihydrofuro [3,4-b] pyridin-5-one; diethylamino-7,8-benzofluorane; 3,3-bis (1-ethyl-10 2-methylindol-3-yl) phthalide; 3-diethylamino-7-anilino-fluorane; 3-diethylamino-7-benzylamino-fluoran; 3'-phenyl-7-dibenzylamino-2,2'-spiro-di- [2H-1-benzopyran] and mixtures thereof.

Further, microcapsules may optionally contain the following solvents: 1. Dialkyl phthalates having 4 to 13 carbon atoms in alkyl groups, such as dibutyl phthalate, dioctyl phthalate, dinonyl phthalate, and ditridecyl phthalate. 2. 2,2,4-Trimethyl-1,3-pentanediol ( U.S. Patent 4,027,065) 3. Ethyldiphenylmethane (U.S. Patent 3,996,405) 4. Alkyl biphenyls such as Monoisopropyl Biphenyl (U.S. Patent 3,627,581) •. 5. C10-C14 alkylbenzenes such as dodecylbenzene; 6. diaryl ethers, di (aralkyl) ethers and aryl aralkyl ethers, ethers such as diphenyl ethers, dibenzyl ether and phenyl benzyl ether 30 7. liquid higher dialkyl ethers (containing at least 8 carbon atoms) at least 9 carbon atoms) V · 9 alkyl or aralkyl benzoates, e.g. benz: 35 alkyl benzoates 10. alkylated naphthalenes • 11. partially hydrogenated terphenyls 13 109190

The solvent, if used, may be selected to assist in the dissolution of the dye mixture, if used. If the capsules contain chromogen, the latency of the receiving sheet can be visualized by various conventional acidic developers, preferably in the form of a dispersion or solutions, which are applied to the receiving sheet of the latent image after the latent image is formed. Other alternatives may be to place the acidic developer in a substantially chromogenic medium. The developer can be placed in capsules and the chromogen applied after breakage, or alternatively the chromogen may be placed in capsules.

Examples of suitable acidic developing agents are: clays, treated clays (U.S. Patents 3,622,364 and 3,753,761); aromatic carboxylic acids such as salicylic acid; aromatic carboxylic acid derivatives and their metal salts (U.S. Patent 4,022,936); phenol developers (U.S. Patents 3,244,550 and 4,537,063); acidic poly-20 polymers such as phenol-formaldehyde polymers, etc. (U.S. Patents 3,455,721 and 3,672,935); and metal-modified phenolic resins (U.S. Patents 3,732,120, 3,737,410, 4,165,102, 4,165,103, 4,166,644 and 4,188,456).

Microencapsulation methods are now well known in the art. U.S. Patent No. 2,730,456 describes a process for making capsules. Other inexpensive methods. . for the manufacture of microcapsules are disclosed in U.S. Patents I. 4,001,140, 4,081,376 and 4,089,802, which describe urea and •; 30 formaldehyde reactions; U.S. Patent 4,100,103, '·' ', which describes the reaction between melamine and formaldehyde; British Patent 2,062,750, which describes a process for the manufacture of • V microcapsules, wherein the walls are made by · polymerization of melamine and formaldehyde in a styrene barrier, ·,; 35 in the presence of phonic acid. Preferred methods of the invention; wherein ureaformalde is used to form the microcapsules. hydrous resin and / or melamine formaldehyde resin as described in U.S. Patents 4,001,140, 4,089,802, 4,100,103, 4,105,823 or 4,552,811. The 4,552,811 method is recommended. For further information, reference is made to these patents.

I 5 The recording material comprises a substrate or substrate material, which is generally sheet-like. For the purposes of the invention, the substrate means may be referred to as sheets and also include webs, rolls, tapes, tapes, belts, transparencies, cards and the like. Sheets mean 10 pieces having two large surface dimensions and a relatively small thickness dimension. The substrate or substrate material may be opaque, transparent or translucent and may itself be colored or colorless. The material may be a fibrous material, such as paper, and a synthetic filament material. It may be a film such as molded, extruded or otherwise formed cellophane and a synthetic polymer sheet.

The binder may be added to assist in the attachment of the capsules to the substrate, and may, for example, with butter, e.g. - · '. Acetate and polystyrene may be advantageously used.

The following examples are intended to illustrate. . the invention and should not be construed as limiting it. [In which all parts or parts are by weight and I »»; 30 all dimensions are metric unless otherwise stated.

I · I

109190 15 i EXAMPLE 1

Measuring the Surface Temperature Using a Fax Machine 5 Coatings on a thin translucent paper substrate were prepared from a color forming dispersion. The coating segments were taped to a sheet of bond paper and used as a print sheet on a Canon Fax-230. The melting was clearly visible in clear (amorphous) letters on a relatively opaque-10 wedge background. Using this technique, the temperature on the sample surface was obtained by Canon Fax-230 at least above 170 ° C.

Color Melting Melt + Fax in Melt? 15 ________________ dibutyl N102 «170 ° C yes PSD-150 * 200 ° C no

Green 118 * 230 ° C not 20 + determined using flour dust on Kofler Hot Bar.

EXAMPLE 2 25 PREPARATION OF MICRO CAPSULES Inner phase (IP) • 20 g N102: * 30 180 g trimethylolpropane triacrylate (TMPTA) monomer * 2 g 2-isopropylthioxanthone photoinitiator 2 g ethyl 4-dimethylaminobenzoate> 2-phenylacetophenone photoinitiator »i *. 35 The first two components are combined and dissolved by heat, then the photoinitiators are dissolved.

• ♦ 16 109190

Outer phase (EP) 25 g Colloid 351 (= 25% solids) acrylic polymer, Rhone-Poulenc (butyl acrylate) 5 198 g water is adjusted to pH 5.0 with 20% NaOH.

j Emulation 10 170 g of EP are placed in a blender and the IP solution is added with gentle stirring. The mixer speed is increased to achieve the desired droplet size (e.g., 50% by volume of about 4.0 µ) as measured by a Microtrac particle size analyzer, Leeds and Northrup Instruments, North Wales, PA 19454.

Encapsulation

Combine the following: 20 25 g Colloid 351 (= 25% solids) 42 g water adjust pH. To 4.8 with 20% NaOH 30 g Cymel * 385 (= 80% solids) · ·, 25, ·, ·. 70 g of the above are added to the emulsion and transferred to a water bath. The emulsion is heated while stirring to 65 ° C and allowed to process for several hours !. i time for encapsulation to occur.

: * 30 * · * I I · '·' * Cymel is a trademark of American Cyanamid Company. Cymel 385 is an etherified methylol melamine oligomer.

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»* 17 109190

COVERING

Combined in equal parts: 5 1. Prepare capsule dispersion 2. 10% aqueous solution of Airvol 103 This mixture is applied to paper or any other desired substrate using, for example, a fixed slit spreader set at 0.001 inch. The resulting dried coating can be used to produce a latent image on a thermal printer such as a commercial facsimile machine.

A latent image can be generated by contacting it with a developer suitable for 15 N102 colorformers. A typical example is a 20% solution of Durez # 27691 (p-phenylphenolformaldehyde resin) in xylene. This resin may also be applied as an aqueous dispersion or emulsion and then heated to promote the development of black copy.

20

The resulting copy can, if desired, be "fixed" or deactivated with respect to heat and / or pressure by UV exposure to polymerize the components. About 5 seconds of exposure with a 15-watt GE lamp F15T8-BLB is sufficient to "fix" the copy. After attachment, the sheet will be copied to ·, ·, Resistant to abrasion or abrasion.

i '| ',! Because the coating is reactive in nature prior to application, Γ »,,; If this is done, it may cause handling damage. They can be • · "30 reduced with an overcoat that does not interfere with the thermal pattern 'and subsequent attachment exposure. A typical overcoat is obtained by applying a 10% solution of Airvol * 540 on a # 3 t * t •' / <wire twisted rod.

• »». . 35 * Airvol is a trademark of Air Products and Chemicals, Inc., »*» · ·! and it is polyvinyl alcohol.

»» '# »I · t *» »* 18 109190

Photoinitiators can be omitted from the capsules of the latent image receiving sheet. Chromogen may or may not be used as needed.

EXAMPLE 3

DRY DEVELOPMENT

a. Two sheets were prepared: 10 - a second sheet was coated with the microcapsule composition of Example 2 - a second sheet was coated with a color developer composition 15b. The capsule-coated sheet was patterned using a thermal print head.

c. The textured capsule sheet was superficially combined with a color developer sheet. The developer sheet is a sheet coated with a phenolic resin dispersion 20 (= 50% solids) of Durez 32421 benzoic acid, 2-hydroxypolymer, formaldehyde, nonylphenol and zinc oxide. The sheets joined together were transported between two melting rolls heated to 110 ° C.

25 »d. The color developer sheet substrate was peeled off. Underneath it revealed a fully developed image left on the pattern sheet.

EXAMPLE 4 '30V: INTERNAL PHASE (IP)

160 g TMPTA

! Y: 40 g of Durez 27691 (p-phenylphenol-formaldehyde resin) .35 12 g of 2,2-dimethoxy-2-phenylacetophenone (photoinit.) »I i»! t 'J t

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19 109190

The resin is dissolved by heating to TMPTA, a photo-initiator is added and dissolved. This IP is encapsulated as in Example 2 and the resulting capsule dispersion is coated and overcoated. The coated material is fed through a commercial facsimile machine to form a pattern. This pattern is developed by applying to it a commercial tint, such as Minolta MT Toner II. The black tinting particles selectively attach to the broken capsules. The tint in the background is removed by light-brush brushing or the like. The tintor is thawed in an oven or heating drum or similar.

EXAMPLE 5 15 As in Example 4 but faxing and applying the toner were repeated to add another color. By repeating the process, multi-color images can be obtained.

EXAMPLE 6 20

PAPER ONLY / TRANSFER

a. A tinted plastic sheet (as in Examples 3 or 4) was bonded to bond paper, and sheets I25 were transported together between two melting rolls heated to 90 ° C.

b. The plastic sheet was removed.

• · 30 c. The decal was obtained on paper alone.

EXAMPLE 7V: PATTERNED PATTERN 35a. Melamine formaldehyde (MF) microcapsules of the invention containing only sec-butylbis-109190 phenyl solvent (SureSol 290) were prepared.

b. A patterning sheet was prepared by coating microcapsules on a plastic sheet and applying a PVA overcoat.

! 5 c. A latent image was generated using Canon 230 fax in copy mode.

d. A portion of the sample was placed in a container containing 10 commercial tints (electrostatic dye tinters).

e. The container was tightly closed and shaken to apply a tint to the sample surface.

15 f. After brushing excess tint from the sample, a red image on a white background was obtained.

EXAMPLE 8

20 TEMPERATURE TRANSMISSION TAPE

a. A microencapsulated latent image sheet containing no toner or color developer was used.

25 b. A latent image was recorded on a sheet using a Canon 230 fax machine.

c. The imaged sheet with selectively broken capsules or latent image was brought into contact with the lämpösiir 30 tonauhan-coated side, and passed to heat "melting nettujen between the rolls. 1 · 'd. When the heat transfer tape was removed, a color image was obtained on the micro · · · capsule image sheet.

35 21 109190 EXAMPLE 9

TRANSFER

5a. A latent image was recorded on a sheet of blank or solvent-only microcapsules using a Canon 230 fax machine.

b. Blue ink was uniformly applied to the surface of the sheet.

c. Excess color was removed by squeezing the colored picture sheet against smooth clay coated paper.

15th The colored surface of the previous sheet was placed over a sheet of paper alone and transported through a steel press roll nip. (Pressure used 170 silicon). The paper received a blue high contrast print, silicon = pounds per linear inch.

20 e. Black commercial ink was also used. Excess color was removed from the sample with a sharpened tool. Move | ron paper was followed by a black print on a pure white background.

25 EXAMPLE 10

TRANSFER SHEET

| ; 1 Inner Phase (IP) 30 V 1 180 g Trimethylolpropane Triacrylate (TMPATA) Monomer • 20 g 1,3,3-trimethylindolino-6 'chloro-: 8' methoxybenzopyrylospirane.1.35 12 g 2,2-Dimethoxy-2-phenylacetophenone ! (photoinitiator) • »22 109190

The components are combined and dissolved by heating. IP is encapsulated as in Example 1 and the resulting capsule dispersion is applied to a suitable substrate using a # 12 wire twisted rod. The coating was dried and overcoated with 10 5% aqueous Airvol 540 using a # 3 wire twisted rod. The coated material is transported through a commercial facsimile machine to form a master image.

When the master image is heated in contact with the developer sheet, a copy is obtained as a result of spiral sublimation of the 10 capsules disrupted as shown. The patterned master could be used several times to make additional copies. The textured copies are obtained on a commercially available carbonless CF sheet containing e.g. a p-phenyl-phenol-formaldehyde-type resin.

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Claims (8)

109190: 1. A latent image receiving sheet comprising a substrate bearing a microcapsule containing a nuclear substance, characterized in that: (a) the walls of the microcapsules are of an unmeltable polymer with an elongation not exceeding 1% and are prepared in situ polymerization in an aqueous medium of resins selected from melamine and formaldehyde, methylol melamine, or methylated methylol melamine, wherein the polymerization is carried out at a temperature of at least 65 ° C, at about 75 ° C; (B) the microcapsules are heat resistant, such that they do not become substantially permeable when placed in an oven at 150 ° C for 1 minute; (c) however, the microcapsules are breakable when subjected to a point energy amount comprising at least 115 ° C Δ per millisecond, preferably at least 145 ° C per millisecond; ; provided that the latent image receiving sheet does not contain complementary reactive imaging reagents on the same surface of the sheet. I t> * I 2. Latentbildmottagande ark enligt krav 1, colors kernel-15 materialet innefattar en tryckfärg, farkämne, toner, chromogen, lösningsmedel, gas, hydrophobic varnish pigment. The latent image receiving sheet of claim 1, wherein the core material comprises an ink, a dye, a tinting agent, a chromogen, a solvent, a gas, a hydrophobic liquid or a pigment. ... 3. A latent image receiving sheet according to claim 1 or 2, wherein the sheet is an ink transfer sheet or 35 sheet. 24 109190 3. Latentbildmottagande ark enligt krav 1 eller 2, color-cid arket et tryckfärgsöverföringsark eller tryckp- 20 Age. 4. Latentbildmottagande ark enligt krav 1 eller 2, the colors on the arch and the engraving. The latent image receiving sheet according to claim 1 or 2, wherein the sheet is a gravure printing sheet. i 5. Latentbildmottagande ark enligt krav 1 eller 2, var- '_ · vid arket and ett cryptomedeland-mottagande ark. • · The latent image receiving sheet of claim 1 or 2, wherein the sheet is a cipher sheet. 6. Latentbildmottagande ark enligt krav 1 eller 2, var-vid arkket and bildframställande ark. ! ·: *. 30 The latent image receiving sheet of claim 1 or 2, wherein the sheet is an image forming sheet. 7. Förfarande för att framställa en latent bildpä ett. latentbildmottagande ark enligt face av föregäende krav, 'innefattande steget av att selective applicera en punk-; · * energy efficiency innefattande ΔΤ av minst 115 ° C per mil-; ··; 35 additional hours in the account, at a temperature of 145 ° C per millisecond. 26 109190 A method of generating a latent image on a latent receiving sheet according to any one of the preceding claims, comprising the step of selectively applying to the sheet a point energy comprising at least 115 ° C ΔΤ: η per millisecond, preferably at least 145 ° C per millisecond. . Use of a latent image receiving sheet according to claim 1 in a thermal imaging method wherein the latent image is formed by selectively applying to the sheet 20 points of energy comprising at least 115 ° C · ·· * ΔΤ: η per millisecond, preferably at least 145 ° C. per millisecond. · '.' Patent patent i «: V 2 5 ·. * · 1. Latentbildmottagande ark, innefattande et substrat bärande microkapslar innehällande et kärnmaterial, kän- ·. * ·: Neecknad därav, att J '·'; 30 (a) microcapsular larvae of the polymeric som * »har en working with the 1% ooh framställts genom '. in situ polymerisation i en vattenhaltig framställnings- ,,, bärare av hartser Valda bland melamine och formaldehyd, "·" methylolmelamine, eller methylylad methylolmelamine, colors 35 polymerisationen et förts 65 ° C; 109190 (b) micro-capsule-motif motom, som-fast-genome att inte bli i tirentlig grad genomic transgeneration at 150 ° C per minute; (C) microcapsule emulsifiers for brytbar application applicators, point energy at 115 ° C per millisecond, rotor trough 145 ° C per millisecond; 10 med färutsättning att det latentbildmottagande arket inte uppbär complementary med varandra inbördes reactive bild reagent head off. 8. Användning av et latentbildmottagande ark enligt krav 1 i et thermic bildframställande förfarande, i flash en latent image framställs genomic sliding application av en point energy innefattande ΔΤ av minst 115 ° C 5 per milliseconds arc ark, företrädes . !