Label continuum and producing method thereof

Abstract: This invention relates to a label continuum comprising a long label substrate, an adhesive layer formed on the back thereof, a heat-sensitive developing layer formed on the surface of the label substrate and a release layer formed on the surface of the label substrate opposite to the adhesive layer when the label substrate is rolled up. The invention also relates to a producing method of the label continuum which comprises a step 1 of preparing a process sheet with at least either surface thereof having a releasability and forming an adhesive layer on the release surface of the process sheet, a step 2 of preparing a long label substrate with the back to which the adhesive layer is transferred and stuck and of mating together the back of the label substrate and the adhesive layer of the process sheet, a step 3 of forming a release layer on the surface of the label substrate, a step 4 of releasing only the process sheet from the surface of the adhesive layer transferred to the back of the label substrate, and a step 5 of rolling up the label substrate so that the release layer and the adhesive layer are false-stuck to each other.

Description: Field of the Invention: The present invention relates to a method of producing label continuum formed of a plurality of continued labels and, in particular, the so-called non-separable type of label continuum with no release paper which is particularly suitable for e.g. price tag or barcode label and a producing method thereof. Description of the Prior Art: As a so-called non-separable label with no release paper, there has hitherto been a label with a delayed tack type of heat-active pressure-sensitive adhesive layer formed on the back of a heat-resistant substrate. Such continuum of labels with a heat-active type of pressure-sensitive adhesive layer formed on one side thereof can be used in a rolled form without any release paper on the back side thereof. That is to say, if such continuum of labels are rolled up, they don't adhere because such a label has no adhesiveness before pressure sensitivity is imparted by melting the sensitive layer. Such prior art non-separable type label, however, requires a large-scale production equipment, which is inevitably expensive, and the label's substrate is required to be heat-resistant such as paper since it has to be heated to activate the adhesive agent. Further, the substrate is required to be safe against any of the components of the adhesive forming the adhesive layer, consequently, the width of selection is quite limited. EP-A-0 579 430 and EP-A-0 600 622 disclose a non-separable label with no release paper in which the label continuum comprises a long label substrate with a pressure-sensitive adhesive layer on one side of the label substrate and a thermosensitive layer and a release coating on the other side of the label substrate, such label continuum being capable of being wound to form a roll of label continuum. Heating of the pressure-sensitive adhesive layer, such as of the water-based, solvent-based or hot-melt types, during the formation thereof must be carried out under conditions which do not cause significant adverse reaction of the thermosensitive layer. The substrate for use in the label continuum may be supplied in the form of conventional thermal paper. EP-A-0 579 430 also discloses a non-separable label in which a pressure-sensitive adhesive layer is applied on one side of a long label substrate and a release coating is applied to the other side. The label continuum is heated following application of the pressure-sensitive adhesive and before being wound in roll form. SUMMARY OF THE INVENTION Therefore, the object of the present invention is to widen the range of selection for the label substrate and the adhesive layer and to provide a method of producing a label continuum suitable for production of variegated small lots. The present invention is defined by a method of producing a label continuum comprising: a step 1 of preparing a process sheet with at least one surface thereof having releasibility and forming an adhesive layer on the release surface of said process sheet; a step 2 of preparing a long label substrate to a first side of which said adhesive layer is transferred and stuck and of mating together said first side of said label substrate and said adhesive layer of said process sheet; a step 3 of forming a heat-sensitive layer, which develops upon heating, on the opposite side of said label substrate; a step 4 of forming a release layer and/or printed layer on the opposite side of said label substrate; a step 5 of releasing only said process sheet from the surface of the adhesive layer transferred to the first side of said label substrate; and a step 6 of rolling up said label substrate so that said release layer and/or printed layer are false-stuck to said adhesive layer. A first embodiment of the invention relates to the above-described method of producing a label continuum in which a release layer is formed in step 4. In the first embodiment of the invention, the adhesive layer is formed on the label substrate's surface by the use of the process sheet having a release surface, and hence the adhesive layer is transferred to the surface of the long label substrate from the process sheet when it is pressed against the long label substrate. According to the first embodiment of the invention, the adhesive layer formed on the surface of the process sheet and the surface of the long label substrate onto which the adhesive layer is to be transferred and stuck are pressed together and the adhesive layer is transferred from the process sheet's surface to one side of the long label substrate at room temperature, and hence even if the label substrate is relatively low in heat resistance and extremely thin, an adhesive layer can be formed. Further a thermal paper made to develop when heated may be selected as the label substrate. Also, since the solvent contained in the adhesive agent for formation of the adhesive layer when it is in emulsion form is removed as the adhesive layer is formed on the process sheet, there is no risk of solvent or the like affecting the label substrate. Hence, the width of selection for the label substrates and adhesive agents for formation of the adhesive layers is by far greater and this is suited for variegated small lot production. The process sheet can be reused many times over, this being advantageous for reuse of resources as well as for dust saving. In the first embodiment of the invention, the step 1 may include the step of preparing the releasable process sheet by printing or coating the sheet's surface with releasing agent. In this embodiment, since the adhesive layer is formed by the process sheet made releasable by printing or coating the surface of the sheet with a release agent, hence the adhesive layer is transferred from the process sheet to the surface of the long label substrate when it is put on the long label substrate surface. According to this invention, the adhesive layer is formed on the release surface of the process sheet and when it is mated with the one side the long label substrate onto which the adhesive layer is to be transferred and stuck, it is possible to transfer the adhesive layer from the process sheet to the back of the long label substrate by the action of the release agent. In the first embodiment of the invention, the step 2 of preparing the wide and long label substrate and mating one side of the label substrate with the adhesive layer of the process sheet may include a step of rolling up after slitting in a proper width. In this invention, the adhesive layer formed on the process sheet is transferred to one side of the label substrate. When the adhesive layer is formed as a plurality of label substrates of a predetermined width, waste parts may result in the side borders but, according to the invention, first long label substrate wider than the label substrate of the predetermined width and the process sheet are prepared, and the label substrate is formed by slitting it in a proper width, the adhesive layer formed on the release surface of the process sheet can be formed with some excessive side parts of the process sheet, the waste parts on both sides of the process sheet can be reduced, and the label substrate of the predetermined width can be increased, this being very useful. In the first embodiment of invention, the steps 4 and 5 may include the step of unrolling the rolled up label substrate for formation of printed and/or release layers. In this embodiment, roll-like laminates of label substrate and the process sheet with an adhesive layer in between are unrolled for formation of the printed layer and/or release layer. According to this invention, it is possible to have the printed layer and/or release layer formed in the predetermined position properly, this being very useful. A second embodiment of the invention relates to a method of producing a label continuum wherein step 4 involves forming a printed layer and a release layer on said opposite side of the label substrate, whereby upon rolling up the label substrate the release layer and the adhesive layer are false-stuck to each other. In the second embodiment of the invention, the adhesive layer is formed on the label substrate's surface by the use of the process sheet having a release surface, and hence the adhesive layer is transferred to the surface of the long label substrate from the process sheet when it is pressed against the long label substrate. According to the second embodiment of the invention, the adhesive layer formed on the release surface of the process sheet and the surface of the long label substrate onto which the adhesive layer is to be transferred and stuck to are pressed together and the adhesive layer is transferred from the process sheet's surface to one side of the long label substrate at room temperature, and hence even if the label substrate is relatively low in heat resistance and extremely thin, an adhesive layer can be formed. Further a thermal paper made to develop when heated may be selected as the label substrate. Also, since the solvent contained in the adhesive agent for formation of the adhesive layer when it is in emulsion form is removed as the adhesive layer is formed on the process sheet, there is no risk of solvent or the like affecting the label substrate. Hence, the width of selection for the label substrates and adhesive agents for formation of the adhesive layers is by far greater and this is suited for variegated small lot production. The process sheet can be reused many times over, this being advantageous for reuse of resources as well as for dust saving. In the first or the second embodiment of the invention, the step of releasing only the process sheet from the surface of the adhesive layer transferred to the back of the label substrate may include a step of slitting the label substrate and the process sheet together with other layers laminated in a previous step in a proper width. In such embodiment, the process sheet and the long label substrate are cut together with the other layers. Although if the adhesive layers are formed as a plurality of label substrates of the predetermined width, waste parts should occur in both side borders of each label substrate, it is possible in this invention that the long label substrate wider than the label substrates and process sheet are first prepared and then piled one upon another by the use of the adhesive layer and then slit to have its width adjusted to the predetermined value and it is possible to have the adhesive layer formed on the process sheet's release surface, and narrow margins on both right and left ends of the process sheet and the waste parts in both side borders are decreased, this enabling formation of more label substrates of the predetermined width and being very useful. In the first or the second embodiment of the invention, the step of releasing only the process sheet from the surface of the adhesive layer transferred to the back of the label substrate may include a step of die-cutting to a proper width together with other layers laminated in a previous step. In this embodiment, the process sheet is not cut and the label substrate and other layer are cut together. According to this embodiment, the wide and long label substrate and the process sheet are prepared, these are laid one upon the other by means of adhesive layer and then the label substrates are die-cut in a proper width. The label intended first can thus be properly formed, this being very useful. In the first or the second embodiment of the invention, the step of forming the release layer on the surface of the label substrate may include a step of printing or coating a release agent on the surface of the label substrate. In this embodiment, since the label substrate is rolled up for the release layer and the adhesive layer on the label substrate to be opposed and false-stuck to each other, the rolled up label continuum can be unrolled. According to this invention, when an adhesive layer is formed on the release surface of the process sheet and then pressed against one side of the long label substrate onto which the adhesive layer is to be transferred, the adhesive layer can be transferred from the process sheet to such side of the long label substrate by the action of the process sheet. In the first and the second embodiment of the invention, the step of forming the release layer on the surface of the label substrate may include a step of forming a release layer on the surface of the label substrate through lamination of films or sheets having excellent releasability characteristics for the purposes of this invention. In this embodiment, since the label substrate is rolled up with the release layer and the adhesive layer false-stuck to each other, the rolled up label continuum can be unrolled. According to this invention, an adhesive layer is formed on the release surface of the process sheet and it is possible to transfer the adhesive layer from the process sheet to one side of the long label substrate by the action of the process sheet having a release surface. A third embodiment of the invention relates to a method of producing a label continuum wherein step 4 involves forming on one side of the label substrate a printed layer having excellent releasability characteristics for the purposes of this invention. In the third embodiment of the invention, the adhesive layer is formed on the surface of the process sheet by the use of a process sheet having a release surface and hence the adhesive layer is transferred from the process sheet to the surface of the long label substrate when they are put together. According to the third embodiment of the invention, the adhesive layer formed on the release surface of the process sheet and the surface of the long label substrate onto which the adhesive layer is to be transferred are put together and the adhesive layer is transferred from the surface of the process sheet to one side of the long label substrate at room temperature, and hence even if the label substrate is relatively low in heat resistance and extremely thin, the adhesive layer can be formed, since the solvent contained in the adhesive agent for formation of the adhesive layer when it is in emulsion form is removed from the process sheet before the adhesive layer is transferred from the surface of the process sheet for formation of the adhesive layer on the label substrates. Further a thermal paper made to develop when heated may be selected as the label substrate. Also, since the solvent has been previously removed, there is no risk of the label substrate being affected by solvent or the like. Hence, the width of selection for the label substrates and the adhesive agents for formation of the adhesive layer is quite large and the method of the invention is suited for variegated small lot production. The process sheet can be reused many times over, this being advantageous for reuse of resources as well as for dust saving. In the third embodiment of the invention, the step 5 may include a step of slitting the label substrate laminated in the steps 1-4 in a proper width and the process sheet together with other layers formed. In this embodiment, the process sheet and the long label substrate are cut together with other layers. Although if the adhesive layers are formed as a plurality of label substrates of the predetermined width, waste parts should occur in both side borders of each substrate, it is possible in this invention that first the long label substrates and process sheet are prepared and then they are piled one upon another by the use of the adhesive layer and then slit to have its width adjusted to the predetermined value and it is possible to have the adhesive layer formed on the process sheet's release surface, and narrow margins on both right and left ends of the process sheet and the waste parts in both side borders are decreased, this enabling formation of more label substrates of the predetermined width, and being very useful. In the third embodiment of the invention, the step 5 may include a step of die-cutting the label substrates laminated in the steps 1-4 together with other layers in the predetermined width. In this embodiment, the process sheet is not cut, while the label substrate is cut together with the other layers. According to this invention, the wide and long label substrate and the process sheet are prepared, they are laid one upon the other by means of the adhesive layers, and by die-cutting the label substrate in a proper width for formation of a proper label width, the predetermined labels can be formed, this being very useful. In the third embodiment of the invention, the step 4 may include a step of printing or coating a printing ink having excellent releasability characteristics for the purposes of this invention on one side of the label substrate. In this embodiment, since the label substrate is rolled up for the printed layer and/or release layer and the adhesive layer to be opposed and false-stuck to each other, the rolled label continuum can be unrolled. According to this invention, the adhesive layer is formed on the release surface of the process sheet, and when it is mated with one side of the long label substrate bonded through transfer of the adhesive layer, it is possible to transfer the adhesive layer from the process sheet to one side of the long label substrate through the action of the release surface of the process sheet. In the third embodiment of the invention, the step 4 may include a step of forming the printed layer and of forming a release layer having excellent releasability characteristics for the purposes of this invention on one side of the label substrate. In this invention, since the label substrate is rolled up so that the printed layer and/or the release layer and the adhesive layer are false-stuck, the rolled up label continuum can be unrolled. According to this invention, the adhesive layer is formed on the release surface of the process sheet and when it is mated with one side of the long label substrate onto which the adhesive layer is to be transferred and stuck , it is possible to transfer the adhesive layer from the process sheet to the long label substrate by the action of the release surface of the process sheet. The aforementioned objects, other objects, features, phases and advantages will become further apparent from reading the detailed description of the embodiments with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an embodiment of the present invention pertaining to a label continuum, of which (A) is a perspective view and (B) is a sectional view. Fig. 2 is an illustratory view showing an example of the method of producing what is shown in Fig. 1, showing the first half of the process. Fig. 3 is another illustratory view showing an example of the method of producing what is shown in Fig. 1, showing the second half of the process. Fig. 4 is a sectional view of a label continuum as another embodiment of the invention. Fig. 5 is an illustratory view showing another example of the method of producing what is shown in Fig. 4. Fig. 6 is a sectional view showing another embodiment of the invention pertaining to a continuum of label. Fig. 7 is an illustratory view showing an example of the method of producing what is shown in Fig. 6. DESCRIPTION OF THE PREFERRED EMBODIMENTS A label continuum 10 may be produced by the method of the invention, formed as a belt-like repetition of a plurality of labels 12, each label 12 being separated by cutting along the border line therebetween. The pressure sensitive adhesive layer is formed by transferring to the back of a long label substrate 14, an adhesive layer 16 having adhesion at room temperature and stuck to the substrate when a low pressure is applied. The other side of the label substrate 14 has formed thereon a release layer 18 and a printed layer 20 is formed on the label substrate 14 and between the label substrate 14 and the release layer 18. The printed layer 20 is formed intermittently, i.e. with the predetermined spaces between the expressions of adjacent labels 12 having border line therebetween. As shown in Fig. 1 (A), the label continuum 10 is rolled up before use as labels with the release layer 18 and the adhesive layer 16 false-stuck to each other. In this embodiment, a heat-sensitive layer 22 is formed on the release layer 18 side's surface of the label substrate 14. The long label substrate 14 in this embodiment is made of, for example, paper, synthetic paper, plastic film or sheet such as of cellophane, polystyrene and polyester or aluminium foil. In order to cut the long belt type of label continuum without seams between the individual labels 12, however, such material is required to be cut by hand or proper machine such as a cutter. It is also possible to provide seams at the predetermined intervals (not shown) for cutting off each oblong label 12. The adhesive layer 16 formed by application of an adhesive agent to the back of the label substrate 14 is for imparting adhesive force to each label 12 and for this purpose known adhesive agents such as of acrylic copolymer or rubber-type adhesive agent are used. The heat-sensitive layer 22 is formed on the surface of the label substrate 14 by coating and drying a heat-sensitive developing agent including a mixture of e.g. transparent or single-color leuco dyes, acid substance and binders. As leuco dyes may be cited, for example, crystal violet lactone, 3-indolino-3-p-dimethylaminophenyl-6-dimethylaminophthalid, 3-diethylamino-7-chlorofluoran, 2-diethylamino-7-cyclohexylaminofluoran, 3-diethylamino-5-methyl-7-t-butylfluoran, 3-diethylamino-6-methyl-7-anilinofluoran, and 3-diethylamino-6-methyl-7-p-butylanilinofluoran. As acid substances may be cited, for example, 2,2-bis (4'-oxyphenyl) propane, 4-phenylphenol, 4-hydroxyacetophenone, 2,2'-dihydroxydiphenyl, 2,2'-methylene bis (4-methyl-6-t-butylphenol), 4,4'-isopropylidenediphenol, 4,4'-isopropyriden bis (2-chlorophenol), 4,4'-isopropyridene bis (2-methylphenol), 4,4'-ethylene bis (2-methylphenol) and 4,4'-thiobis (6-t-butyl-3-methylphenol). As binders may be cited, for example, aqueous solution or emulsion of polyvinyl alcohol, methoxy cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyacrylamide, polyacrylic acid, starch, gelatin, polystyrene, vinyl chloride-acetic acid vinyl copolymer. The heat-sensitive layer 22 is developed when heated by the thermal head etc. of a printer. On the surface of the heat-sensitive layer 22 of the label substrate 14, the printed layer 20 is formed for expression on the display parts of the individual labels 12 at the predetermined intervals with the border lines therebetween. This printed layer 20 is formed using a general printing ink by a known printing method such as planographic printing, relief printing or offset printing. The release layer 18 on the surface of the label substrate 14 over the heat-sensitive layer 22 and the printed layer 20 is formed by printing or coating of the release agent such as silicone resin which, for instance, can be cured without affecting the heat-sensitive layer 22. In this embodiment, may preferably be selected as the release agent constituting the release layer 18 UV silicone (the so-called silicone of the UV-hardening type) and EB silicone (the so-called silicone of the electronic ray curing type) being cured by UV or electronic ray without affecting the heat-sensitive layer 22. The release layer 18 may be formed by laminating and bonding a film or sheet having excellent releasability characteristics for the purposes of this invention. In reference to Figs. 1-3, first a rolled up long belt-like process sheet 24 made of rolled paper, plastic film or sheet is provided. This process sheet 24 is used only in the production process and is no longer included in the finished label continuum 10. On the surface of the process sheet 24 is formed a release layer 24a made by printing or coating a release agent such as silicone resin or fluorine resin. Then an adhesive agent 26 for formation of the adhesive layer 16 is printed or applied to the surface of the release layer 24a of the process sheet 24. An adhesive coating device 100 includes two rollers 102a and 102b. The roller 102a has its lower part dipped in the adhesive agent 26 in a pan 104. Hence, by rotating the roller 102a and 102b, the adhesive agent 26 is printed on or applied to the surface of the release layer 24a of the process sheet 24 led to the position. As adhesive agent coating device may as well be used a gravure roll coater, reverse roll coater or air knife coater and a known printing machine such as a screen printing machine may also be used. The process sheet 24 printed or coated with the adhesive layer 26 may be led to a drier 106 including, for example, a heater. In the dryer 106, the adhesive agent 26 printed or coated on the process sheet 24 is dried for formation of the adhesive layer 16. When the adhesive agent 26 is a watersoluble aqueous resin such as of EVA type, vinyl acetate type and acrylic type or solvent type adhesive agent comprising polyvinyl chloride, urethane, acryl etc. , a dryer is used, while a cooler is to be used when the adhesive agent used is of the hot melt type such as of the rubber type or EVA type. On the release layer 24a of the process sheet 24 the adhesive layer 16 is formed, and to the back thereof, paper 14a as the label substrate 14 is laminated. The paper 14a of the label substrate 14, too, is formed in the same width as that of the process sheet 24, and on the surface of the paper 14a as the label substrate 14 is already formed the heat-sensitive layer 22. The heat-sensitive layer 22 is formed on the side opposite to the aforementioned adhesive layer 26. Thus, the laminate of the process sheet 24, adhesive layer 26 and the label substrate 14 is, before it is led to the next printing process or the like, slit in approximately the same width as the width of the label continuum 10 as the final product by a slitter 108 and then rolled up after slitting. A laminate 30 of the process sheet 24 and the label substrate 14 is false-stuck by the adhesive layer 16 and rolled up and led to the next step of using the printing and release agent coating device shown in Fig. 3. Next, the rolled up laminate 30 is loaded on the production system shown in Fig. 3, the laminate 30 is unrolled and led to the printing device 110 for formation of the printed layer 20. This printing device 110 is for printing the expression constituting each label 12, for example, letters such as trade name, proper patterns etc. by a known printing device for planographic, relief printing or offset printing. The laminate 30 with printed layer 20 thereon is led to a release agent coating device 120 to have the release layer 18 formed on the surface of the printed layer 20 on the label substrate 14. This release agent coating device 120 is made up of a main roller 122a and a roller 122b formed opposite to the main roller 122a. The main roller 122a has its lower part dipped in a dissolved release agent 32 in a pan 124 and the release agent 32 is applied by the main roller 122a to the surface of the label substrate 14 of the laminate 30 passing through between the main roller 122a and the roller 122b. The laminate 30 printed or coated with the release agent 32 is moved to a dryer 126 including e.g. a heater. In the dryer 126, the release agent 32 printed or coated on the laminate is dried and the release layer 18 is formed. The label continuum 10 of the laminate 30 with release layer 18 formed thereon is led to the process sheet removing device 130. This process sheet removing device 130 includes a roller 132 and peels the process sheet 24 off from the surface of the adhesive layer 16 of the laminate 30 and the peeled process sheet 24 is rolled up for reuse. Meanwhile, the laminate 30 constituting the label continuum 10 is rolled up with its both sides or either side being slit by a slitter 140 to make its width to be optimum. It may as well be possible to die-cut the label substrate 14, adhesive layer 16, printed layer 20 and heat-sensitive developing layer 22 only to be finished by cutting. Fig. 4 is a sectional view of a label continuum which can be produced by a method of the present invention, and Fig. 5 is an illustratory view showing an example of a method of producing what is shown in Fig. 4. In the label continuum 10 of this embodiment, a first printed layer 21a is formed by a printing ink having excellent releasability characteristics for the purposes of this invention where the release layer 18 is not formed on the surface of the label continuum 10 and a second printed layer 21b is formed in a portion of the surface of the label substrate 14 between the release layer 18 and the label substrate 14. In this embodiment, too, the heat-sensitive layer 22 is formed on the surface of the label substrate 14 on the same side as the release layer 18. This means that the release layer 18 is formed on one side of the label substrate 14, that is to say, on the surface of the heat-sensitive layer 22 and the second printed layer 21b. The second printed layer 21b is formed with an ordinary printing ink and is formed intermittently at a constant distance between the expression of the individual labels 12 so that the expression of each label 12 is formed apart from its border line. That is to say, in this embodiment is shown on the surface of the heat-sensitive layer 22 the second printed layer 21b forming the expression of each label 12 apart from its border line. This second printed layer 21b is printed and formed with an ordinary printing ink by a known method of printing such as planographic, relief printing and offset printing. However, this second printing layer 21b may not be formed. Of the label continuum 10 shown in Fig. 4, the laminate 30 of the label substrate 14 and the process sheet 24 for the first half of the production process is produced by the same device as shown in Fig. 2 and the production device for the second half of the production process for the label continuum 10 shown in Fig. 4 is shown in Fig. 5. The rolled laminate 30 is loaded in the production device shown in Fig. 5 and is unrolled and led to a printing device 110 for formation of the second printed layer 21b. This printing device 110 is for printing the expression constituting each label 12 and, for example, letters such as trade name and proper pattern are printed by a known printing device such as planographic, relief printing and offset printing machine. Then, the laminate 30 with the second printed layer 21b formed thereon is led to a release agent coating device 120 for forming the release layer 18 on the surface of the second printed layer 21b. This release agent coating device 120 includes the main roller 122a and the roller 122b formed opposite to the main roller 122a. And, the main roller 122a has its lower part dipped in the release agent 32 in the pan 124 and the release agent 32 is applied to the laminate 30 through between the main roller 122a and the roller 122b by means of the main roller 122a. The laminate 30 with the release agent 32 printed on or applied to is moved to the dryer 126 including, for example, a heater. In the drier 126, the release agent 32 printed on or applied to the laminate is dried to form the release layer 18. Then, the laminate 30 is led to a printing device 115 for forming the first printed layer 21a with a printing ink excellent in releasability where the release layer 18 is not formed. The laminate 30 with the first printed layer 21a formed thereon is sent to a dryer 117. Thereafter, the label continuum 10 formed by lamination of the first printed layer 21a, the release layer 18 and the laminate 30 is led to a process sheet removing device 130. The process sheet removing device 130 includes the roller 132, and the process sheet 24 is removed from the surface of the adhesive layer 16 of the laminate 30 and rolled up for reuse. Meanwhile, the laminate 30 constituting the label continuum 10 is rolled up with its both sides or either side being slit by the slitter 140 with its width to become optimum. Instead of slitting, die-cutting may be possible. Fig. 6 is a sectional view of a label continuum which can be produced by a method of the invention, and Fig. 7 is an illustratory view showing an example of a method of producing what is shown in Fig. 6. This label continuum 50 has a release layer 58 formed on its surface on one side of a label substrate 54, being different from the examples shown in Figs. 1 and 4. Further, a first printed layer 60 is formed on the surface of the release layer 58. It is same as in the examples shown in Fig. 1 and Fig. 4 insofar as an adhesive layer 56 is formed on the opposite side of the label substrate 54, and it is also the same as in the examples shown in Fig. 1 and Fig. 4 insofar as a heat-sensitive developing layer 62 is formed on the surface of the label substrate 54. As the printing ink for formation of the first printed layer 60, it is necessary to select one having releasability itself. As to the label continuum 50 shown in Fig. 6, a laminate 70 of the label substrate 54 and a process sheet 64 for the first half of the production process is produced by the same device as shown in Fig. 2. The production device for the second half of the production process for the label continuum 50 shown in Fig. 6 is so arranged that a release agent 72 is printed on or applied to the surface of the laminate 70 on one side of the label substrate 54 by means of a release agent coating device 220 and the release agent 72 so printed or applied to is cured by the curing device for formation of the release layer 58 and downstream the printed layer 60 is formed on the release layer 58 by the use of a printing device 210, as shown in Fig. 7. In Fig. 7, different from Figs. 3 and 5, a slitter 240 for slitting the label substrate 54 for its width adjusted to the optimum width of the label continuum 50 is positioned downstream immediately before rolling up but after process sheet 64 is stripped from the pressure sensitive type adhesive layer 56 by a process sheet removing device 230. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims: A method of producing a label continuum (10,50) comprising: a step 1 of preparing a process sheet (24,64) with at least one surface thereof having releasibility and forming an adhesive layer (16,56) on the release surface of said process sheet (24,64); a step 2 of preparing a long label substrate (14,54) to a first side of which said adhesive layer (16,56) is transferred and stuck and of mating together said first side of said label substrate (14,54) and said adhesive layer (16,56) of said process sheet (24,64); a step 3 of forming a heat-sensitive layer (22, 62), which develops upon heating, on the opposite side of said label substrate (14, 54); a step 4 of forming a release layer (18,58) and/or printed layer (21a,60) on the opposite side of said label substrate (14,54); a step 5 of releasing only said process sheet (24,64) from the surface of the adhesive layer (16,56) transferred to the first side of said label substrate (14, 54); and a step 6 of rolling up said label substrate (14,54) so that said release layer (18,58) and/or printed layer (21a,60) are false-stuck to said adhesive layer (16,56). A method in accordance with Claim 1, wherein the step 1 includes a step of preparing a process sheet (24,64) with its surface made releasable by printing or coating a release agent. A method in accordance with Claim 1 or 2, wherein the step 2 includes a step of preparing wide and long label substrate (14,54) and laying the back of said label substrate (14,54) on the adhesive layer (16,56) of said process sheet (24,64), this followed by slitting in a proper width and rolling up. A method in accordance with Claim 3, wherein the step 4 and step 5 include a step of unrolling the rolled up label substrate (14,54) and of forming thereon a release layer (18,58) and/or printed layer (21a,60). A method in accordance with Claim 1 including both a step of forming a printed layer (21a,21b,60) and a step of forming a release layer (18,58) on said opposite side of said label substrate (14,54). A method in accordance with Claim 1 or 5, wherein the step of releasing only said process sheet (24,64) from the surface of said adhesive layer (16,56) transferred to said first side of said label substrate (14,54) includes a step of slitting in a proper width said label substrate (14,54) and said process sheet (24,64) laminated in the previous step together with other layers formed. A method in accordance with any one of Claims 1-4, wherein the step of forming a release layer (18,58) on said opposite side of said label substrate (14,54) includes a step of printing or applying a release agent on said opposite side of said label substrate (14,54). A method in accordance with Claim 1 or 6 including the step of forming a printed layer (21 a,60) by printing or coating an ink high in releasability. A method in accordance with Claim 1 or 6 including the step of forming a release layer (18,58) high in releasability on said opposite side of said label substrate (14,54) together with said printed layer (21a,60). A method of producing a label continuum according to Claim 1, wherein said adhesive is a pressure-sensitive adhesive. A method of producing a label continuum according to Claim 1, wherein in step 4 the release layer is formed on said opposite side of said label substrate by lamination and bonding of a film or sheet.

Inventors: OSAKA SHOZO, OSAKA, SHOZO
Applicants: PETTER CO LTD, PETTER CO., LTD.
Application year: 1995
Main classification: G09F3
IPC codes: G09F3, B31D1