MXPA99011697A - Pad including adhesively adhered sheets - Google Patents

Abstract

A pad of paper sheets is constructed so that individual sheets may be removed from the pad without the individual sheets having any aggressively tacky or repositionably tacky coatings on exposed surfaces of the sheets after removal. There is no need for padding compounds or coatings on exterior edges or sides of the pads. A process for forming such a pad of sheets which can be separated into individual sheets having no aggressively or repositionably tacky surfaces comprising the steps of:(a) applying a coating of adhesive to a surface of a first sheet of paper, causing a first bond strength between said adhesive and said surface, and leaving an unbonded surface of adhesive exposed away from said paper, (b) for a measurable period of time allowing said adhesive to alter its physical properties so that its tackiness on its unbonded surface decreases, (c) contacting a second sheet of paper to said unbonded surface to bond said unbonded surface to said second sheet of paper, the bond between said second sheet of paper and the adhesive having a bond strength which is at least 10%lower than the bond strength between said adhesive and said first sheet of paper, (d) repeating steps (a), (b) and (c) on said second sheet of paper to create a stack of sheets which are individually separable from each other.

Description

BLOC THAT INCLUDES SHEETS ADHERED ADHESIVELY BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to flexible sheet blocks and to a method for forming said blocks. The invention relates more particularly to adhered, stacked blocks of sheets which are adhesively secured to one another but which have little or no adhesive property to other surfaces when the sheets are removed from the pad. Background of the Technique Blocks of flexible paper sheets, often called note blocks or note blocks, have been available for a time in a number of sheets and in different configurations including rectangular, round, oval, regular, irregular and from another periphery. The sheets in these blocks can be printed, optionally, with lines, drawings, tops, names of companies or corporations, or that can provide a form that will be used by a person or a business. These blocks are often made by forming large master sheets whether printed or not, by assembling the master sheets in a master pad with a rigid backsheet as well as the bottom sheet, by cutting a plurality of blocks of a desired size from the master block by using a guillotine or die, and then applying a block former (e.g., a block former based on water or organic solvents or a hot melt adhesive block former) to the surface of the the edges of the blocks to secure the individual sheets in a secured pad. The individual sheets can then be removed from the top of the blocks by detaching them from the shaper of the pad. In some of these blocks (usually with a large number of sheets forming a block, generally in the form of a cube), graphics are printed for purposes such as advertising or decoration, along the exposed edges of the sheets in the bloc and alo long of the block former that adheres to the sheets in the pad. Such an impression will have a different appearance along the block former than along the edges of the sheets, which may be undesirable. Blocks of flexible paper sheets that have bands of repositionable pressure-sensitive adhesive on the adjacent edges of the main surfaces of the sheets that adhere the sheets together in the blocks, have been available for some time under the brand of named notes Commercial name "Post-it" (TM) of Minnesota Mining and Manufacturing Company, St. Paul, Minnesota. Such blocks are available with repositionable pressure-sensitive adhesive strips along the edges of the sheets that are placed on a side surface of the stack. Additionally, said blocks are available with the band of repositionable pressure sensitive adhesive on each successive sheet in the pad along all the edges of the sheets that are placed on a side surface of the stack. Additionally, said blocks are available with the band of repositionable pressure-sensitive adhesive on each successive sheet in the pad along with a surface of the two opposite of the pad as taught in the U.S. Patent. No. 4,781,306 (Smith). This last block structure facilitates the dispensing of the sheets of the blocks of the dispensers of the types described in the Patents of E.U.A. 4,781,306 (Smith), 4,653,666 (Mertens) and 5,080,255 (Windorski). Blocks of any of these types may have graphics printed on the edges of the sheets along all of their side surfaces and those graphics may have a similar appearance on all sides of the pad. Provided the band of repositionable pressure sensitive adhesive on the sheets in said pad, the cost of the pad is increased, however, and for some purposes, the repositionable pressure sensitive adhesive strip on the sheets removed from the pad is not necessary or It may be undesirable. For example, when notes are to be written on the sheets and carried in a bag or purse, the repositionable pressure sensitive adhesive, and especially a pressure sensitive adhesive plus source, causes the sheet to adhere to surfaces or collect Dispersed matter and getting dirty.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention comprises both an article and a process for forming said articles. The process for forming a pad of sheets that can be separated into individual sheets that do not have aggressively tacky surfaces comprises the steps of: a) applying a coating of adhesive to a surface of a first sheet of paper, causing a first bonding strength between the sheet adhesive and the surface and leaving a non-bonded surface of exposed adhesive away from the paper, b) for a measurable period, allowing said adhesive to alter its physical properties so that its tackiness on its unbonded surface decreases; c) contacting a second sheet of paper to the non-bonded surface to join said non-bonded surface to the second sheet of paper, the bond between the second sheet of paper and the adhesive having a bond strength that is at least 10%. % lower than the bond strength between the adhesive and the first sheet of paper, d) repeating steps a), b) and c) on the second sheet of paper to create a stack of sheets that are individually separable from one another. The articles of the present invention include: 1) a pad comprising a multiplicity of sheets of paper having first sheets and second adjacent sheets adhered to one another along only a portion of faces of the first sheets and second sheets that are they contact between them within the pad, the first and second sheets being adhered between them on an area comprising an adhesive on the surface of a first sheet having a first bonding strength to the first sheet and a second bonding strength to the second sheet, said first bond strength being at least 10% greater than said second bond strength, and 2) a block comprising a multiplicity of sheets of paper having adjacent sheets adhered therebetween along only a portion of faces of the sheets that contact each other within the pad, the sheets being adhered to each other over an area comprising an adhesive over e the surface of adjacent sheets and a release liner on a surface of a sheet in contact with the surface of the sheet having adhesive thereon. It is preferred that the release coating comprises a varnish, preferably a varnish containing hydrophobic functionality and especially a UV curable varnish having hydrophobic siloxane groups therein. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a side view of a pad according to the present invention with all the adhesive connections between the sheets on only one side of the sheets of the pad.

Figure 2 shows a side view of a pad according to the present invention with alternating adhesive connections on opposite sides of alternative sheets in the pad, forming a Z-fold distribution of the sheets within the pad. Figure 3 shows a side view of a pad according to the present invention with an alternative distribution of adhesive and varnish of the construction shown in Figure 1. Figure 4 shows a side view of a pad according to the present invention only with layers of adhesive between the adjacent sheets of paper within the pad. Figure 5 shows a side view of a Z-folded pad according to the present invention only with layers of adhesive between the adjacent sheets of paper inside the pad. DETAILED DESCRIPTION OF THE INVENTION The present invention provides a pad of flexible paper sheets which, like the blocks of the prior art described above that are formed using a block former, are not costly in construction and may have individual sheets removed from the pad. They do not have bands of adhesive that will adhere to most common surfaces. The blocks and sheets of the present invention, unlike the blocks of the prior art described above, if desired, they can be printed on all sides of the stack to provide a uniform appearance on each of their sides and can also be adapted for dispensing from various dispensers including dispensers of cartons, other dispensers using a linked sheet following, or systems such as those described in US Patents us. 4,781, (Smith), 4,653,666 (Mertens) and 5,080,255 (Windorski). In accordance with the present invention, there is provided a pad including a stack of flexible paper sheets and a pad forming means which does not completely cover an outer edge of the pad, the pad forming means releasably adhering to portions of the leading surfaces of adjacent sheets in the stack until the individual sheets of the pad are detached. The tablet forming means comprises at least some of the sheets having patches of a non-tacky adhesive, especially a cold-rolling adhesive (as described herein) coated on the main surfaces of the sheets and preferably the adhesive is optionally adhered to the patterns of a release layer, such as a varnish layer, on the opposite sides of the adjacent sheets in the stack to the releasable adhesion portions of the major surfaces of those adjacent sheets together in relation to each other. Surface to surface until these patterns come off. The blocks without an opposite coating of the release layer could comprise an adhesive (which is not sticky when dried or cured) which is applied in such a way that the adhesive adheres more securely to an opposite sheet within the block. than to another opposite sheet inside the pad. Commonly, to simplify fabrication, the non-tacky adhesive layer when dried, will be secured to the sheets so that a single sheet will have only one layer of adhesive more securely adhered to it without the adjacent layers of adhesive being secured more securely. to the only sheet that to any of the two sheets of paper adjacent to the pad. Preferred materials for use in the respective layers comprise paper varnishes as the release layer, particularly varnishes having hydrophobic functionality included within the composition, as silicone resin or silicone block or graft functionality within the polymer and the adhesives Cold rolling as the adhesive material. Cold rolling or cold transfer adhesives are known materials within the art, particularly within the flexographic printing technique, which is coated as a wet layer and which dries or cures to a non-tacky state, but which retains a Controllable degree of stickiness during the drying or curing stage. It is described in the flexographic technique as particularly useful for the transfer of laminates. Therefore, while the opposing patterns of cold-rolled adhesive and varnish can adhere the sheets to the pad, the cold-rolled adhesive and varnish patterns will not adhere individually to most other surfaces, so that sheets will not adhere to most surfaces after they are removed from the pad. The cold-rolled adhesive patterns and the release layer (e.g., a UV varnish) could have many different shapes, including areas of adhesive in the center of the sheets, which can have any shape such as circular , rectangular, etc., and are particularly useful when applied as strips or narrow strips (1 to 20 mm wide). Some or all of the sheets in the pad, such as those sheets having separable sheets attached to the main surfaces of the sheets, may each have a first strip or strip of cold-rolled adhesive on a first major surface and may have a second one. Release lining band, such as a varnish for U.V. on a second main surface with bellows bands being adjacent to the same shore. This can provide the most common form of pad in which all sheets are attached to the pad along the same side or edge of the main surfaces of the pad. A fundamental aspect of the present invention is to provide a stack of individual sheets that are not aggressively tacky and that are not sensitive to pressure when removed from the stack. Each individual sheet within the stack adheres to each of the two sheets that are adjacent to each individual sheet (the upper and lower sheets, of course, not having two adjacent sheets, but only a single adjacent sheet). A bonding of adhesives is present between the individual sheets and the adjacent sheets, the adhesive connection or both between the sheets being effected by an adhesive, preferably a cold-rolled adhesive on a main surface of one of the individual sheets and a coating of release, preferably a varnish (preferably a radiation-cured varnish, more preferably a varnish cured with UV radiation) on a main surface of an adjacent sheet. At least some area of the two coatings, the cold-rolling adhesive and the varnish, are present on the areas of the main surface that are directly opposite each other so that the varnish on a main surface of a sheet is in contact with the cold-rolled adhesive on a main surface of an adjacent sheet. The contact between the cold-rolled adhesive on the main surface of a sheet that attaches or secures the sheet to an adjacent sheet by overlapping contact with a coating of varnish on an adjacent sheet is called adhesive contact or adhesive bond in practice of the present invention. The coating areas of the two different contact materials on the opposite surfaces may be identical in size and shape or they may be extremely different, then the physical requirement being only that there is sufficient overlap in the contact area between the two surface coatings opposite to provide the adhesive bond between the two adjacent sheets. The size and shape of two different coatings can be perfectly matched to one another with identical shapes, or they can overlap along a line, or they can have regions of overlap in various portions of their shape but the preferred configuration is to have the size and shape of the almost equal coatings (eg, no more than a difference of twenty-five percent in the total area of the coatings) to maximize the efficiency of the coating and bonding. In any case, there should be sufficient overlap in the contact areas of these coatings to provide adhesion between the two adjacent sheets. The areas where the varnish on the main surface of the first sheet of a pair of adjacent sheets is in adhesive contact with an area of a main surface of the other sheet of a pair of adjacent sheets is termed as the matched area. The two opposite sheets that are secured or joined by an equal area are called the matched sheets. Where there are stacks of sheets, as in the practice of the present invention, to form blocks of these sheets, except the upper and lower sheets, each sheet in the pad is equated to two different adjacent sheets, one relatively above the sheet within. of the pad and the other relatively below the sheet inside the pad. The middle sheet in the consecutive pairs of the leaves, is named as the leaf enters the consecutive pairs of leaves and the remaining equal leaves within the consecutive pairs of leaves are named as the upper sheet and the lower sheet of the consecutive pair , depending on the orientation of the pad. A consecutive pair of leaves, therefore, comprises three consecutive sheets with the central sheet matching the upper and lower sheets. The compositions and materials used in the practice of the present invention can be selected from a wide array of commercially available materials or they can be individually tailored to specific blocks by a user. For example, the most preferred paper stack in the practice of the present invention comprises 18.2 kg satin continuous paper, but materials comprising continuous paper of 3.6 kg to 90.1 kg can be used, and materials are still contemplated outside the scale general. Continuous paper can be raw material paper, coated paper on one side (one coated side) or coated paper on two sides. The paper can be preprinted or not, with alphanumeric indications or artistic prints. The practice of the present invention can be used with the surfaces of the sheets other than paper, such as polymeric film, mixed material, metal foil, or the like, together with the sheet which is somewhat flexible. The adhesive can be selected from a wide array of chemical classes while meeting certain minimum functional capacities. The function of the adhesive is to adhere sheets of flexible paper to form what is commonly called notebook. The adhesive must remain moist, for a defined period and preferably short (less than one minute after coating, and as little as less than five seconds), on each sheet of paper, as they are stacked on top of each sheet Adjacent paper that forms the notebook, allowing attachment to the next sheet of paper. Once the adhesive has dried, it will no longer be sticky, but it will keep the stack of sheets in the form of a scrapbook until each sheet is removed from the pad. The removal of the individual sheets is achieved by breaking the bond of the adhesive (usually the adhesive break, opposite to the cohesive break), with the adhesive remaining on one of the paper surfaces to be separated, but no longer retaining any property aggressively adhesive It is also convenient that the adhesive be selected so that it can be printed or written on with inks as easily as the uncoated areas of the paper sheets. For example, the adhesive may be an acrylic (including methacrylic, acrylamide, etc.), polyurethane, polyamide, vinyl (e.g., polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl acetal, etc.), polyolefin, resin epoxy, and the like, while the adhesive can be formulated to be initially sticky and then becomes non-sticky after the drying / curing period. The non-tacky side can be obtained by simply drying the adhesive by curing the adhesive at room temperature, photo-adhesiveing the adhesive (for immediate or delayed cure of the adhesive) or any other mechanism that allows the adhesive to be coated while in a sticky or bonding state. and then which allows the adhesive to pass in a non-sticky state so that when the sheets are separated from the pad there is no aggressive tack in the adhesive layer. A recognized class in the particular industry of adhesives, cold roll adhesives or cold transfer adhesives, is particularly suitable for the performance of this adhesive in the practice of the present invention. An example of this type of adhesive is the Cold Transfer Adhesive Adhesive Systems, Inc. AS 1545-49A, which is a solution of water-based adhesives of modified acrylic copolymer having 57% by weight solids and a viscosity of 800-1000 cps RV 2/20 rpm at 25 ° C. The adhesives can be used in a form that can reduce or eliminate the need for the release coating on the opposite surface of an adjacent sheet. One way in which this can be achieved is that the degree of adhesion of the adhesive to the adjacent sheets is controlled so that the adhesion is greater than in the other of the sheets. Thus, the sheets will be separated by the failure of the adhesive along the interface of the adhesive and the sheet to which they are less strongly bound. This differential in the bond strength can be achieved by the release liner, or by controlling the adhesion strength of the liner to the respective sheets. This can be achieved in at least two different ways. If the initial adhesive coating has its controlled thickness, when applying the coating to a sheet, there will be a desired level of penetration of the adhesive on the surface of the sheet. If the adhesive coating is within a thin coating utility scale, there will not be enough adhesive to significantly penetrate the opposing sheet when it comes into contact with the adhesive layer. Three could only be a weaker adhesion of the second sheet of adhesive layer compared to the adhesion of the first sheet in which the original coating is applied. Another method to avoid the application of a release coating on a surface is to apply the adhesive to a first sheet, allowing or causing the adhesive to dry or cure, and a point in the drying / curing process where some degree less of glue is still in the adhesive coating, placing the next sheet of paper in contact with the adhesive to create a bond strength with the second sheet, which is a lower strength bond than that achieved with the first sheet. The delay between the application of the coating and contact of adhesive with the second sheet could be sufficient to allow some drying of the sheet. The delay between the application of the adhesive coating and contact with the second sheet could be sufficient to allow some part of the layer to dry or where the start of the adhesive cure can be initiated by a controlled mechanism (e.g. an initiator, thermally activating an initiator, initiating the activator radiation, as with a system of epoxy triphenyl sulfonium tetrafluoroborate, etc.), the initiation can initiate and allow sufficient time for initiation to partially cure or harden the adhesive with the second sheet in contact with the adhesive only after sufficient cure has been presented to create a weaker bond with the second sheet than with the first sheet. There must be at least 10%, more preferably at least 25%, still more preferably at least 40% and still more preferably at least 50% or at least 75% difference in adhesive bond strength, v .gr., measured by the detachment test movement incorporated into the Test Machine (IMP) at no more than 30.48 cm per minute at room temperature after 15 minutes of equilibrium at room temperature and ambient humidity (e.g. 50% relative humidity) between the adhesion of the adhesive layer to the first sheet than the adhesion of the adhesive layer to the second sheet. The release coating layer can be any known release coating material recognized in the art. There are convenient contributions for the release liner. First, it creates a protective coating on each sheet of paper to which it is applied to avoid any opposition of the adhesive to bond very strongly to the paper coated by the release cover, which could make separation difficult and / or cause the fibers and the The printouts are removed from the sheets of paper as they are separated from the pad. Additionally, the release cover helps control the leaf removal forces required for the removal of individual sheets from the notebook. The amount and specific properties of the release coating can be used for this control. For example, a 100% coating strip (continuous coating) could provide a much easier release than a strip of the printed release layer as 1% dots or any other intermediate value (e.g., 20%, 40% of points or dashed lines uniformly of the coating) sifted coating. These release coating materials may comprise silicone or fluorinated resins, for example, or resins modified to contain silicone or flocked groups, or containing silicone or fluorinated oils or mixtures of silicone polymers or fluorinated polymers to alter their properties of adhesion to the surface. These types of resins are well known in the art and can be used, for example, in back side liners for rolls of sheets with an adhesive layer, release surfaces in imaging layers (especially in representation of transfer images), and similar. For example, General Electric Company, Waterford, N.Y. 12188 provides a wide array of silicone resins and oils in the GE Silicones unit that are suitable for this type of purpose. These silicone resins come in a variety of properties and capabilities, including solvent-free systems, UV curable systems, emulsions and solvent systems for application to various substrates and for providing various specific properties. Said resins include, but are not limited to, SL6000, SL6100 and SL6130, Solvent Free UV Polymers UV9300, UV9315 and UV9400, and Release Coatings SM3000, SM3200, and SM 2013, SS4331 Release Coating Systems and Coatings of SS4375 Premium Release. Other low adhesion materials containing release compositions such as fluorinated resins or fluorinated group, highly entangled materials and the like, can also be used to create a release or low adhesion layer opposite the adhesive. The particulate materials can be included in the adhesive or in a release coating layer to further adjust the degree of adhesion between the two layers. Varnishes, as used in the paper industry, especially varnishes containing silicon or silicone materials are generally preferred in the practice of the present invention and an example of the most preferred materials being composition or coating Werneke Co. (Plymouth, MN) UCCXX0038 (UV-20003) Matte Abrasion Resistant, which is a silicon-containing composition curable by ultraviolet radiation having a viscosity of 350 ^ 50 cps at 25 ° C. The construction of the consecutive pairs within the blocks of the present invention is formatted to provide areas of varnish on a major surface of a sheet within the pair which is opposite to, and in contact with, areas of cold rolling adhesive. on a main face of the adjacent sheet within the consecutive pair of sheets. There are numerous configurations that are capable of providing this requirement. The simplest construction can be seen in Figure 1. In this construction, a pad 2 of individual sheets 4, 6, and 8 are shown. The central sheet 4 has a cold-rolled adhesive coating 12 on a main surface 20 of the sheet 4 and a coating of varnish 10 on the other main surface 18 of the central housing 4. The cold-rolled adhesive coating 12 of the central sheet 4 is evened and releasably joined to a varnish coating 16 on the lower sheet 8 and the varnish coating 10 of the central sheet 4 is evened and releasably bonded to a coating of cold rolling adhesive 14 on the upper sheet 6 The figure shows that upper housing 6 has an unmatched release coating layer 22 and lower sheet 8 has an unmatched adhesive layer 24. This layer 22 is not necessary, but tends to be an artifact of manufacturing processes in which the same sides facing the same direction of individual sheets are coated with the same coating material when stacked. The layer 24 can be a necessary artifact of the manufacturing process when it is used to join a corresponding adhesive layer on the backsheet. A reinforcing sheet is usually a sheet of material, of the same type or different from the sheets of paper used to show the end of the stack, and / or to support the stack. It can be paper, cardboard, plastic, cloth, mixed materials, metal, etc., and it can be the same or different color, with or without printing as the sheets inside the pad. A back sheet is combined with the pad during manufacturing. Conveniently it should be applied during manufacturing by contacting a major surface of the backsheet to the second surface of the last sheet in the pad with the transfer adhesive even in a sticky condition, either before or during any drying / curing process. The stickiness of the adhesive or the use of additional adhesive (including different) was used to join the reinforcing sheet in the pad. The equipment is used commercially, which inserts reinforcing sheets on bound sheets of paper during the manufacturing process. Said equipment, provided with the adhesive and / or release systems of the present invention, could form the blocks with reinforcing sheets inserted during insertion during the manufacturing process. Figure 2 shows an alternative configuration of sheets within a pad according to the practice of the present invention. Figure 2 shows a pad 30 comprising four individual sheets, a central sheet 32, and upper sheet 50, a lower sheet 52, and an additional sheet 58 that is not included with the consecutive pairs of sheets formed by the sheets 32, 50 and 52. The central sheet 32 has a coating of cold rolling adhesive 40 and a coating of varnish 38 on the main faces 44 42, respectively. The cold-rolled adhesive coating 40 is adhesively bonded to the varnish coating 48 which is coated on the lower sheet 52 on the relatively left side 34 of the pad 30. The varnish coating 38 is adhesively bonded and matched to the adhesive coating of the adhesive. cold rolled 46 which is coated on the central sheet 32 on the relatively right side 36 of the pad 30. On the relatively right side 36 of the pad 30, the sheet 52 is attached to the sheet 58 through the varnish coating 54 and the adhesive layer 56. This alternative orientation of consecutive equalizations of varnish and adhesive coatings on the sheets within the pad 30 provides what is known in the art as a Z-folded block structure. In this type of structure, as each frame is raised sheet, the next sheet will be angled in one direction with respect to the horizon which is different from the previous sheet. When a certain number of sheets are lifted and supported without separation, they appear to have a continuous configuration of the Z-shape, from which the name of the configuration comes. In Figure 2, the top sheet 50 is shown with a vestigial release liner 60 (on a major surface of the upper sheet 50 opposite the adhesive layer 46) and the lower sheet 58 is shown with a vestigial adhesive lining 60 ( on the upper host upper surface 50 opposite the adhesive layer 46) and lowermost housing 58 is shown with a vestigial adhesive coating 62 as a residue of the coating and stacking process used in the manufacture of the pad. The layer 60 is optional, and the layer 62 is necessary where a reinforcing sheet is to be bonded to the adhesive layer. Figure 3 shows that the configuration and the respective order of the cold-rolled adhesive layers and the varnish layers can vary in the practice of the present invention. For example, the pad 70 shown in Figure 3 has four individual sheets 72, 74, 76, 78 within the pad 70. The lower sheet 72 has both major surfaces coated with varnish coatings 80, 82. The lower adjacent sheet 74 both of their main surfaces are coated with varnish coatings 80, 82. The lower adjacent sheet 74 has both of its main surfaces coated with the layers of cold-rolled adhesive 84., 86, all the layers being along the relatively right side 96 of the pad 70. In the continuous orientation, the next lower sheet 76 has both major surfaces coated with varnish coatings 88.90, and the lower sheet 78 shown in the pad 70 has cold-rolled adhesive layers 92, 94 on both major surfaces. This configuration provides the necessary ratio of varnish coatings on a sheet by being in contact with the coatings of cold-rolled adhesives on the adjacent sheets. The same type of variation shown in the structure relationship of the blocks of Figures 1 and 3 can also be used in the construction of an alternative configuration for the structure of the Z-folded block shown in Figure 2. Each coating on the top sheet 4, could be varnish coatings, each coating the middle sheet 32 could be a cold-rolled adhesive coating, and both coatings on the lower sheet 52 could be varnish coatings and the same can be achieved type of results. Figure 4 shows a pad 100 having three sheets of paper 102, 104, and 106 joined by the adhesive layers 108 and 110 with an outer adhesive layer 112. No release layer is needed in this construction due to the differentiation in adhesive strength between the adhesive layers and the release sheets. respective roles to which they join. Layer 104 is a non-essential residue of the manufacturing process. Figure 5 shows a Z-folded block 120 of paper sheets 122, 124, and 126 that are secured at opposite ends by adhesive layers 128 and 130, with an outer adhesive layer 132. as with Figure 4 , no release layer is needed in this construction due to the differentiation in adhesive strength between the adhesive layers and the respective sheets of paper to which they are attached. Layer 134 is a non-essential residue of the manufacturing process. Any type of pad according to the present invention has a plurality of lattice surfaces defined by the edges of the sheets. If there are a large number of sheets on the pad, each of the side surfaces may have graphics printed on the edges of the sheets so that all the side surfaces of the pad may look similar, which, for example, is convenient in a Notepad with the shape of a cube used for advertising purposes. Some major surfaces of the sheets or portions of the major surfaces may also have printing on them. There are two processes equally rewound to produce the product of the present invention. The first continuous lithographic printing process or continuous flexographic printing and the second process is printing discontinuous or flexographic feed. In continuous lithographic and flexo printing, the paper can be supplied and then in roll form, fed into the printing stations, then into a common coating unit (flexo) and then followed by a UV light source. After these steps, the roll is turned over and fed into a second flexographic coating unit and then into a sheet-forming station followed by a registered stacker. In the printing units, the desired graphics are printed on the paper, using flexographic or lithographic printing. After printing, the ink must be dried using various equipment, some of which may include hot air, infrared, air convection, or UV curing heaters. Then, the UV release coating is applied using the flexographic coating unit. This release coating is pumped into a common closed scalpel system or carried from a tray to an anilox or rotogravure roll, which applies the release coating to a flexographic plate. The anilox roller or rotogravure can vary in sieve count and volume to give variation to the blade removal force. Also, a scalpel is useful for measuring the precise amount of anilox or rotogravure roll coating. The flexographic plate then applies the release coating to the recording paper with the adhesive. The image on the flexo plate can vary dramatically from continuous strips to circles or squares, for full or partial coverage and so on. Also, the flexographic plate can vary in the amount of volume it carries, from very light sieves to a solid covering. This allows flexibility in the force of leaf removal. This release coating is applied to the first major surface of the sheet. The release coating is immediately cured using a UV light source. UV light can vary from a lamp of 1-300 watt by 2.54 cm to a lamp of as much as 3-800 watts by 2.54 cm depending on the speed of the press. The most common light source will be lamps of 2-600 watts by 2.54 cm. The lamps usually provide a distance of 30.48-60.96 cm, but can vary from 15.24 cm to 1.8 m. The length of time during which the coating is cured depends on the size of the lamp and the speed of the press. The duration is not critical, while the release coating is cured at approximately 100% (or at least sufficiently cured to provide the desired properties). After curing of the release liner, the roll is rotated and directed into another flexographic coating unit where the adhesive is applied. The adhesive is applied in the same way as the release coating. It is pumped into a closed scalpel system or carried from a tray to the anilox roller. Again, the anilox roll can vary in counting and volume of screens depending on the desired amount of adhesive. After measuring the adhesive with a scalpel, the adhesive was carried to the flexographic plate, which then applies the adhesive to the paper on the second major surface. The image on the flexo plate can vary in size, shape and volume, using a strip, circle, full coverage square, or using different percentages of screens. An example would be to use a 10% sieve to minimize the amount of adhesive applied. These are only examples, since obviously there is a wide range of possibilities. After adhesive is applied in register on the paper, the network is directed in the sheet forming / stacking unit. The sheet former has a rotating blade that scales the net into sheets of a desired size and then carries the cutting sheets in a band system in the stacker unit which will be stacked in register with each other. The adhesive only dries partially at this point in the process and final curing or drying is completed in a stack over the course of one to 4 days. Additionally, a reinforcing sheet may be inserted into the stack of sheets at selected intervals, the intervals of which may vary by changing the count of batches in the automatic reinforcement sheet inserter. The reinforcing sheet is a thicker sheet pre-coated with paper, which means that it has been previously coated with a release liner and adhesive. A larger amount of adhesive and release liner is generally applied to the backing sheet which will allow a better adhesion to the sheet to which it is put in contact and allows better sliding between each backing sheet as they are stacked before their insertion in the stack of leaves. The reinforcement sheet can be produced with the same process described above.

The pile will continue to accumulate, and the reinforcing sheets will continue to be inserted at selected intervals, making what are called master blocks. A master pad can have several blocks of notes within itself. The master blocks are taken to a common guillotine and cut into individual note blocks which can vary in shape and size. At this point, the note blocks can be cut into the usual die with a common block die cutter or packaged for your boarding Note that master blocks should usually be dried for a minimum of 16 hours before being cut. The adhesive will remain wet to some degree for an undetermined time. When cutting in the guillotine cutter, the booster pressure gauge can be varied from 35.15 kg / cm2 to 386.65 kg / cm2. The greater the applied pressure, the stronger the binding of the finished pad will be and the stronger the leaf removal force. The second processing method involves the feeding of the sheets for lithographic (lithographic) or flexo (flexographic) printing. This process is similar to the continuous printing process, it is only done more commonly in several steps. First, a pre-cut stack of sheets is fixed in a common sheet feed stacker and fed into the printing press one at a time to print the desired graphics. After the graphics have been printed, the sheet is fed back into a stacker and papled into layers of paper. The printed stack is then fed into a flexo sheet feeder unit which applies the release coating in the same basic process as that applied to the mesh press. The coating station could be in line with the printing press or a completely different unit. The release coating is applied to the first major surface. The printed and coated sheet is then fed into a second coated unit where adhesive is stacked. This adhesive is stacked to the second main surface and applied in the same way as the continuous process. As the finished product is shipped in the stacker, the reinforcement sheets will be sent to the stack at selected intervals. These reinforcement sheets were produced in a similar way as described in the continuous process. In addition, another process may be used instead of the process just described. If a lower cost notepad is desired, this product can be manufactured without applying the release coating. The quality is lower, since more paper fibers are exposed to the adhesive and the force of removal of the sheets is generally more aggressive. The process could be the same as before, except that the release coating part of the process can be removed. Also, the adhesive pattern on the flexo plate, in this secondary process, can have many different shapes, sizes, and sieves, to achieve varying degrees of leaf removal force. The increased sheet removal force will choose more paper fibers, delaminate some small parts of the printed image and induce waving of the sheets as the sheets leave the stack. The additives in the ink can reduce these attributes if the printed image area corresponds in a direct relationship with the applied adhesive. To describe the structure of the blocks of the invention, the term "outer edge" is used to describe the actual edge of the paper sheets where the common term was commonly applied. The term inner edge was used to define a portion of the major surfaces of the sheets extending from the outer edge along a major surface of a sheet. This inner edge is the region where the main portion of the adhesive tends to be applied opposite to the outer edge of the sheets. The inner edge of the adhesive on the inner edge does not necessarily have to be in contact with the outer edge of the sheets, but it can be disposed inwardly on the inner surface of the main surface away from the outer edge.

Claims (16)

1. CLAIMS 1. A pad comprising a multiplicity of sheets of paper having adjacent sheets adhered therebetween along a single portion of major surfaces of the sheets that are in contact with each other within the pad, the sheets being adhered therebetween an area comprising an adhesive on the surface of one of the adjacent sheets and a release coating on a surface of a sheet in contact with the surface of the sheet having the adhesive thereon.
2. 2. The pad of claim 1, wherein adhesion occurs only along the inner edges of the leaves.
3. 3. The pad of claim 2, wherein the adhesion occurs along the inner edges on only one side of the sheets in the pad.
4. 4. The pad of claim 3, wherein the adhesive and the release liner are coated on the inner edges of the sheets that share a common inner edge on the pad.
5. The pad of claim 2, wherein the sheets of paper forming the pad have a coating of adhesive or release coating on an inner edge on one surface of the sheet and have another coating of the adhesive or the release coating on the sheet. an opposite inner edge on an opposite side of the sheet so that when lifting a sheet, a Z-shaped fold is formed with a next sheet in the pad.
6. 6. A process for forming a pad of sheets that can be separated into individual sheets that do not have aggressively tacky surfaces comprising the steps of: (a) applying a coating of adhesive to a surface of a first sheet of paper, causing a first bonding strength between the adhesive and the surface and leaving a non-bonded surface of exposed adhesive away from the paper, (b) for a measurable time allowing the adhesive to alter its physical properties so that its tack on its unattached surface decreases, (c) putting contacting a second sheet of paper to the non-bonded surface to join the non-bonded surface to the second sheet of paper, the bond between the second sheet of paper and the adhesive having a bond strength that is at least 10% less than the bond strength between the adhesive on the first sheet of paper, (d) repeat steps a), b) and c) on the second sheet of paper to create a stack of sheets that are in separable one from the other.
7. The process of claim 6, wherein at least eight sheets are placed in a pad by repeating steps a), b) and c).
8. The process of claim 6, wherein the second sheet of paper has a discontinuous coating of a release coating on a surface of the second sheet that is in contact with the adhesive, the release coating decreasing the bond strength between the adhesive layer and the second sheet of paper.
9. The process of claim 6, wherein the first and second sheets of paper forming the stack have a coating of adhesive or release coating on an inner edge on a receiving surface and have another coating of adhesive or release coating on an opposite inner edge on an opposite side of the sheet so that when lifting a sheet, a fold in Z is formed with a following sheet in the pad.
10. 10. The pad of claims 1, 2, 3, 4, or 5, wherein the adhesive comprises a cold transfer adhesive.
11. The process of claims 6, 7, or 9, wherein the adhesive comprises a cold transfer adhesive.
12. 12. A pad comprising a multiplicity of sheets of paper having first adjacent sheets and second sheets adhered therebetween together with only one face portion of the first sheets and second sheets which are brought into contact with each other within the pad, the first sheets and second sheets being adhered between them on an area comprising an adhesive on the surface of a first sheet having a first bonding strength to said first sheet and a second bonding strength to the second sheet, the first bond strength being at least 10% greater than the second bond strength where the faces of the paper sheets have the same coating surface thereon and no block formation coatings are present on the sheets of paper.
13. The pad of claim 12, wherein the adhesive comprises a cold transfer adhesive.
14. The pad of claim 12, wherein all the faces of the paper sheets have the same paper coating surface coated thereon and the block-forming coatings are not present on the paper sheets.
15. 15. The pad of claim 12, wherein there are no release liners present on the surfaces of the paper sheets.
16. 16. The pad of claim 1, wherein at least eight sheets of paper are present in the pad.