JPS61202882A - Picture forming device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

BACKGROUND OF THE INVENTION The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus in which a colorless image forming fluid is fully applied to an opaque open-cell microporous layer provided on a substrate having a contrast. It relates to a device for.

Several U.S. patents (e.g. No. 2,299,991,
No. 3,031,328, and W. 3,508,34.
No. 4) IC discloses a composite sheet material in which a layer of light-coloured, opaque brushed lacquer is coated on a support sheet which is either darkly colored or imprinted with contrasting indicia. The opaque and light color of the paint-painted lacquer film is due to the fact that it contains a large number of micropores; (1) heat or pressure (either of which irreversibly destroys the micropores); or (2) Localized application of a non-solvent liquid (which fills the micropores) selectively renders the coating transparent or translucent, and the underlying support becomes visible. The harmless non-solvent liquid used to impart transparency to the opaque microporous Jl11 can later evaporate to restore its original appearance. The liquid, which is the solvent for the lacquer coating, will of course become permanently transparent by destroying the micropores.

U.S. Pat. No. 2,854,350 describes a structure functionally similar to that described above, except that the single layer of brushed lacquer was replaced by a microporous layer of finely divided calcium carbonate in an organic binder. is listed. Transparency is imparted by applying pressure locally or by treating selected areas with a wax, oil or grease having a refractive index similar to that of calcium carbonate. Other pigments may be incorporated into the microporous highly plasticized resin binder; see US Pat. No. 3,247,006.

It is often desirable to have a microvoided sheet material that can be repeatedly cleared by the application of liquid, but not by the application of heat or pressure.

In such circumstances, the U.S. patent owned by the assignee may have a
Microvoided layers of the type described in US Pat. No. 9,880 are preferred. This patent states that the microvoid content consists essentially of particles held in pseudo-sintered parallelism by a thermosetting binder and that the agglomerated n1t-
A structure having the following structure is disclosed.

Tatami cohesion values are estimated by knife-coating a dispersion of the composition onto a clean gray cold-rolled steel panel, drying and curing as appropriate for the composition and applying a 50-60μ thick coating.
It was obtained by providing . ``Balance Beam Screezo Adsorption'', sold by Garner-Uza-Radley's, Inc., Petesda, Maryland.
A sapphire-tipped needle is lowered into contact with the panel under test using an "Anr. Marr Tester" and held in place while the panel is moved by a mounting platform supported on pole bearings. The minimum I force required to form a 50 μm deep scratch in the coating in one pass at 40× magnification is determined and reported as the cohesion value.

Products of the above type incorporate organic polymers into the microporous layer that gelatinize the clarifying liquid and prevent lateral movement, thus allowing the display to retain its initial sharpness. Further improvements can be made by: see, for example, US Pat. No. 4,418,098.

If the microporous coating is sufficiently durable (particularly of the type described in U.S. Pat. No. 4,199,880), it can be reused many times and therefore can be used in student workbooks, overlays, etc. It has the potential to be incorporated into Hella transparencies, computer cars, optical peripheral recognition devices, bingo cars, steno bluff pads, easel parts, etc. This type of micro? @Nitrolayer can also be used on the surface of three-dimensional objects, such as a doll whose apparently pale lips become temporarily red when a clarifying "lipstick" is applied to reveal the color of the bottom. It enables the development of unique toys such as For all applications of this type, it is important that the evaporation of the clarifying liquid is complete so that the original appearance is restored. U.S. Patent No. 4,29
No. 9,880 and No. 4,418,098, a particular marking fluid is selected based in large part on its evaporation rate, which is inversely proportional to image persistence.

Although there are a number of techniques by which a clarifying liquid can be applied to the surface of a microporous layer, such as by stamping, typewriter ribbon, or sponge, particularly preferred imaging devices include felt, extruded polymer, or A pen with a porous nib made of compressed fiber bundles. Unfortunately, however, once the clarifying liquid is incorporated into an imaging device, the expected number of possible uses is much lower than anticipated. In some cases, even two applications of the same-area summation device for a given microporous substrate have resulted in the presence of permanently visible "ghost" images.

SUMMARY After extensive research, the inventors have determined that the purity of the imaging fluid is of great importance in obtaining an imaging device that can be used repeatedly without leaving permanent marks on the transparentizable substrate. It was confirmed. Not only is it important to use an imaging fluid that is itself essentially free of contaminants, but also any contact parts of the reservoir and the receptacle in which it is housed are free from contaminants. It is important to be free from pollution. pollution is
It can result from the presence of any solid or liquid substance that is dissolved in the imaging fluid and has an evaporation rate that is less than about one half of the evaporation rate of the imaging fluid. Problems arising from the use of solid pollutants are easily foreseeable. However, it is equally true that liquid materials that evaporate much more slowly than the imaging fluid will cause highly undesirable image persistence.

The present invention includes a reservoir incorporated into a receptacle, an imaging fluid within the reservoir, and directing the fluid from the reservoir to a location where a mark is to be applied to a substrate. To provide an image forming apparatus which is combined with a means for feeding out. This imaging fluid is an 8A clear colorless harmless liquid (
i.e., it does not dissolve or disrupt the microporous layer to which it is applied, nor has it been demonstrated to be harmful even in small amounts taken into the body). . In addition, the liquid must be completely evaporative and have an evaporation rate of the order of 20 to 10-6 (compared to vinegar dn-decyl = i,o o). The core of the invention is that the fluid has a concentration of about 500 ppm or less (preferably 50 ppm or less, more preferably about 5 ppm) by weight.
contaminants having an evaporation rate of less than about 100 ml of the liquid. This pollutant is the Yotsu button mentioned earlier.
It may be another liquid present in the imaging liquid or it may be a solid. If the contaminants in the imaging fluid are present in amounts of 500 ppm or less, the microporous substrate can be imaged and imaged repeatedly at least about 100 times before any ghosting is observed. When the contamination level 'lr is reduced to 50 ppm, the number of uses increases to approximately 1000, and the value is further reduced to 50 ppm.
When lowering to ppm, the number of times it can be used without ghosting increases by about 10,0 OOIC.

A particularly preferred embodiment of the invention is a pen of the type in which either a long cylindrical felt nib or a longitudinally porous relatively stiff polymer nib extends from the reservoir to act as a writing tip. be. In many such constructions, the reservoir consists of a bundle of fine fibers (often sealed within a tubular film envelope) that is mounted inside the pen body. A vent may extend vertically through the reservoir to equalize the internal and external pressures as the imaging fluid is drawn from the reservoir of the pen by capillary action during use. Sources of contamination in this type of construction are the plasticizers typically added to the PVC venting tube, the surface finishes applied to the fibers during processing, the plastic sheath surrounding the fibrous reservoir, and the pen barrel. A female agent or a low molecular weight polymer attached to the inside, etc. All such contaminants can be removed by washing the pen components in acetone, heptane, etc. or for a period long enough to evaporate, oxidize, or carbonize the contaminants (e.g.
It can be removed from the pen components by heating the pen components (at 120° C. for 72 hours).

I prepared four identical felt-tip pens. Each is 2u
diameter nib and a reservoir consisting of polyester fibers encased within a polyester film with a pair of 1 mm outer diameter plasticized polyvinyl chloride CPVC) degassing tubes extending the entire length of the reservoir. It generally had a cylindrical shell.

The length of the reservoir was 9.6α and the diameter was 7.8B, so the total volume was about 4.4d. Then, add an evaporation rate of 0.18 (vinegar 111n) to the control pen reservoir.
-Detyl=1.00; ASTM test D3539
2.81! Ll was added. The pen was mounted in a holder at a 60° angle to the horizontal, and the pen was contacted with a microporous sheet material of the type described in Example 1 of U.S. Pat. No. 4,299,880. When moving along a 12.5m path while maintaining the condition &
A vertical pressure of C100, SF was applied to leave a 2IIIE wide visible image on the sheet.

After 5 minutes (during which time virtually all of the isoparaffin solvent has evaporated), 5-
I felt a strain. After an additional 5 minutes, the image was still visible, indicating the presence of relatively non-volatile contaminants. The reservoir was then removed from the pen and squeezed to squeeze out as much of the isoparaffin imaging liquid as possible.

The liquid was then injected into a packed chromatography column (see A8TM Test 8260-73). It showed that the amount of contaminants was about 50,000 ppm.

The microporous layer was approximately 25 μm thick; it is clear that the contamination tolerance of the imaging liquid is directly related to the thickness of this layer. In reality, the thickness is approximately 10±2μm~
The range may be 40±6 μm. The exact nature of the components of the microporous layer (particularly the fillers) may also affect specific results.

The other three pens were then tested in the same manner as the control, except as noted below.

Example 1: PVC venting tube was eliminated.

Example 2: The PVC gas vent was removed, and the insertion port was thoroughly cleaned with acetone and dried. Additionally, prior to filling with isoparaffin, the tubular reservoir was placed 5 with the lower end in a tray of acetone and an absorbent mat of blown microfibers was contacted with the upper end. When the acetone was wicked up by the fibers, the contaminants were transported along with it. After 7 hours, the reservoir was inverted and a drop of liquid was squeezed out from the upper end, placed on a microscope slide, and allowed to evaporate. If significant residue remained, this process was repeated until the droplets left no appreciable residue after evaporation, after which the reservoir was allowed to air dry for at least 16 hours. (The main contaminant was found to be glycerol trizotylate.) Example 3: PVC venting tube was eliminated. In addition,
Before filling with isoparaffin, the spigot and reservoir should be
Heated at 0°C for 72 hours.

The results are as follows: Control 50.000 11
10.000 53
50 1.000 (estimated) Example 4 Same as Examples 1-3 except that the reservoir was made of cellulose acetate fibers, there was no venting tube, and the main source of contamination was glycerol) IJ acetate. Two essentially identical felt-tip pens were prepared. Cfu~C8
Examples 1-3 Using Isoparaffin Imaging Liquid
The test procedure was repeated. The isoparaffin evaporation rate was 2.8 (n-decyl acetate-1,00) and the image durability was 6 seconds. In Example 4, the cellulose monoacetate fibers were removed before introducing the imaging liquid and replaced with cellulose acetate fibers without surface lubricant before loading with isoparaffin. The results are as follows: Control 50.000 1 Examples 5 and 6 Polynocopylene 4 instead of cellulose fibers in the reservoir
J! Two pens were prepared that were substantially the same as those used in Example 4, except that fibers were used.

The imaging liquid used in this case was diisobutyl ketone with an evaporation rate of 0.14.

It was found that extractable low molecular weight polyzolopyrene was still attached to the fiber surface. In Example 5, the shell and fibrous reservoir were thoroughly rinsed with cleI ethane according to the procedure of Example 20 prior to addition of the imaging fluid. In Example 6, the polypropylene fibers were replaced with special lubricant-free fibrillated polyzolopylene fibers. The results are tabulated below: Control 10.000 56
33 1.000 (estimated) 薯I
LZ Length 7.8311E, width 12.5iow, thickness 0.12m installed in polyphenylene oxygen cartridge
The woven nylon fiber typewriter ribbon has an evaporation rate of 0.
001 diethyl azopic acid imaging fluid 5 dt-filled. The sample was then mounted on a typewriter and struck 10 bits on the sheet material of the tights used in the previous example, and the imaging fluid was allowed to evaporate.

(Nominal image persistence of 3 hours was reduced by heating the imaged sheet material to 100° C. for about 30 seconds.) Then, the same processing top H1-beat again and this process was "yeasted" after heating. This process was repeated until the image could be detected.

In Example 7, 1 ml of sulfur was added before filling the can with diethyl adipate (to remove the main contaminant, light mineral oil).
, 1.1-trichloroethane and dried. The results are tabulated below: Control 2.000 257
50 1.000] and 12.7 (1!1!) installed in a polypropylene container.
A control standard stamp parar made of cotton felt measuring 7.6 m x 51111 mm was prepared. (This felt was found to contain a light mineral oil lubricant.) This band was given an evaporation rate of 10-6, indicating that the expected persistence of the image would be 1.5 years under indoor conditions. directly charged with 10 d of tributyl citrate. In Example 8, before impregnation with tributyl citrate, J'! A similar pad was used except that the cotton felt of e[IIL was replaced with pure cellulose fiber felt ("100 Chikoton Unizolyl Handy Packet" supplied by Kendall). A 12.7 m diameter circular clean cotton felt stamp was forced into tight contact with the imaging fluid-containing pad and then applied to the surface of the sheet material used in the previous example. Since it is clearly impractical to wait 18 months for the imaging fluid to evaporate, the imaged sheet material was heated to -175 DEG C. for about 15 seconds after each imaging step. The results are summarized below: Control 1,200 4
08 500 100 (estimated) The product of Example 8 shows that the image can last for a considerable period of time and, when it no longer serves its purpose, can be "erased" by heat, allowing the sheet material to be used repeatedly. ing.

Claims (5)

[Claims] (1) a reservoir incorporated into the receptacle, an imaging fluid within the reservoir, and a recirculation of the fluid from the reservoir to a location where a mark is to be applied to the substrate; An image forming apparatus consisting of a combination of means for producing an image,
The imaging fluid is clear, colorless, and non-toxic.
consisting essentially of a fully evaporable liquid with an evaporation rate of the order of 6 (n-butyl acetate = 1.00);
Less than about 500 ppm of the fluid is about 1% of the evaporation rate of the liquid.
The device comprises a base covered with a relatively light-colored opaque open-cell microvoided layer that becomes translucent when the microvoids are filled with liquid. can be used repeatedly to apply an indicia to the same area of a substrate of a type having an indicia, such repeated uses leaving no visible trace of previously applied indicia;
An image forming apparatus characterized by: (2) The image forming apparatus of claim 1, wherein about 50 ppm or less of the fluid comprises a substance having an evaporation rate less than 1/2 of the evaporation rate of the liquid. (3) about 5 ppm or less of the fluid is 1 % of the evaporation rate of the liquid;
2. The image forming apparatus of claim 1, comprising a material having an evaporation rate of less than /2. (4) The image forming apparatus of claim 1, wherein the reservoir comprises a bundle of fine fibers sealed within a tubular film envelope. (5) The device is a pen having as a dispensing means a relatively rigid, axially porous, elongated polymeric nib, one end of which extends into the reservoir and the other end of which is inserted into the reservoir. 5. The image forming apparatus of claim 4, wherein the image forming apparatus extends from the mouth and constitutes means for applying the mark to the substrate.