Fiber-based transparent tape, method for producing the same, and use thereof

Abstract

The present invention relates to the field of the adhesive tape industry, and more particularly, to a base paper for adhesive tapes and adhesive tapes for packaging and office / stationery use. According to one particular embodiment, the adhesive tape of the present invention may be based on transparent paper, one side of the paper being coated with a release agent and the other side being optionally coated with a primer coating. The present invention also relates to a method of producing the adhesive tape base paper and the adhesive tape, and their use as packaging or office / stationery tapes.

Description

Technical Field

[0001] The present invention relates to the field of the adhesive tape industry, and more particularly to an adhesive tape base paper and an adhesive tape for packaging applications and office / stationery applications. According to one particular embodiment, the adhesive tape of the present invention may be based on a transparent paper, one side of the paper being coated with a release agent and the other side optionally being coated with a primer coating. The present invention also relates to a method of producing the adhesive tape base paper and the adhesive tape, and their use as packaging or office / stationery tapes.

Background Art

[0002] Currently, most of the packaging tapes and office / stationery tapes are plastic-based and are neither biodegradable nor compostable. Due to the ongoing goal of avoiding the use of plastics and meeting the requirements of the disposable plastic ban directive, there is a need to provide a sustainable solution for providing new adhesive tapes with a high bio-based content. Furthermore, plastic-based tapes known from the prior art are difficult to tear, and the use of a dispenser for tearing or cutting such tapes is essential. The use of such types of dispensers causes additional costs to the end user. Furthermore, the dispenser may break or may not be compatible with the dimensions of the tape.

[0003] Several fiber-based adhesive tapes have been disclosed. Patent Document 1 discloses Japanese paper tape impregnated with a binder composition. Patent Document 2 discloses glassine paper used to form office tapes. Patent Document 3 discloses tracing paper suitable for laminating and packaging applications. The tracing paper includes a coating for improving transparency and providing waterproof properties to the tracing paper. Patent Document 4 discloses a writable office tape, and the office tape includes glassine paper or tracing paper. Glassine paper is also known to have a low opacity to enable automatic detection of labels disposed on such glassine paper. Glassine paper is disclosed, for example, in Patent Documents 5, 6, and 7. However, glassine paper generally does not have a sufficiently low opacity to be suitable for use as an adhesive tape base paper, and some mechanical properties of glassine paper, such as elongation, are not suitable for the converting process for forming small rolls of adhesive tape. The basis weight of glassine paper is usually too high to be suitable for use as an adhesive tape base paper. To solve the opacity problem of glassine paper, Patent Documents 8 and 9 disclose the use of a clarifying agent that requires additional chemicals and additional process steps.

[0004] To date, the solutions proposed in the prior art are known to be affected by several drawbacks. Specifically, these solutions are known to provide insufficient mechanical properties and transparency that are inappropriate for the intended purpose of known cellulose fiber-based tapes or in the converting process into small rolls. In addition, known cellulose fiber-based adhesive tapes often need to be impregnated with binders or other additional chemicals to provide the required mechanical properties such as tensile strength and internal bond strength.

[0005] To provide a sustainable, highly bio-based and highly transparent adhesive tape and overcome at least some of the drawbacks in the art, the applicant has developed a new cellulose fiber-based adhesive tape base paper and adhesive tape that are suitable for recycling in the recycling streams of standard paper and cardboard, while providing good tensile strength, low basis weight, suitable elongation, and excellent transparency.

[0006] Furthermore, the new adhesive tape base paper and adhesive tape have the advantage of being easy to tear regardless of the presence or absence of a tape dispenser. In fact, existing plastic-based office adhesive tapes require a dispenser to tear, and even when a dispenser is used, existing adhesive tapes may be difficult to tear.

[0007] Furthermore, the new adhesive tape base paper can be repulpable and recyclable, preferably entirely so. The adhesive tape can also be repulpable and recyclable, specifically, the release agent can also be repulped.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

[0009] The present invention is defined by the features of the independent claims. Some specific embodiments are defined in the dependent claims. The present invention is based on the concept of providing a semi-transparent or transparent paper containing highly refined cellulose fibers as a cellulose fiber-based substrate for an adhesive tape. The cellulose fiber-based substrate can be coated on one surface using a release agent. In some embodiments, the cellulose fiber-based substrate can be coated on the other surface with a primer agent.

[0010] According to a first aspect of the present invention, there is provided a cellulose fiber-based semi-transparent or transparent adhesive tape base paper, which comprises a cellulose fiber-based substrate containing highly refined cellulose-based fibers having a pulp freeness of °SR 70 to 90 using the Schopper-Riegler method. The substrate has a first surface and a second surface on the opposite side of the first surface. A release layer is provided on the first surface of the cellulose fiber-based substrate, and the cellulose fiber-based substrate has an opacity index in the range of 13 to 40%.

[0011] According to a second aspect of the present invention, there is provided a method for producing a cellulose fiber-based adhesive tape base paper, the method comprising providing or producing a cellulose fiber-based substrate containing highly refined cellulose-based fibers having a pulp freeness of °SR 70 to 90 using the Schopper-Riegler method, applying a release layer on the first surface of the cellulose fiber-based substrate, and optionally applying a primer layer on the second surface of the cellulose fiber-based substrate.

[0012] Embodiments of the present invention include an adhesive tape, i.e., a base paper for the adhesive tape including an adhesive layer of a pressure-sensitive adhesive polymer, and the adhesive layer is applied on the second surface of a cellulose fiber-based substrate or on an optional primer layer.

[0013] Significant advantages are obtained by the present invention. As described above, in contrast to plastic-based adhesive tapes, this adhesive tape is suitable for recycling in the standard paper and cardboard recycling streams according to EN13430. This product has a high bio-based content and is compostable for industrial and household use.

[0014] Second, this adhesive tape has excellent transparency due to the transparency of the base paper for the adhesive tape having the same range of opacity as the cellulose fiber-based substrate. Furthermore, this adhesive tape does not require a tape dispenser for cutting clean strips like plastic-based tapes. Since the edge tear resistance of this adhesive tape is low, it is possible to cut this adhesive tape without requiring a tape dispenser.

[0015] Still further, this adhesive tape has good tensile strength comparable to that of common plastic-based tapes. This adhesive tape and the base paper for the adhesive tape also have high internal bonding and strong barrier properties without impregnating the cellulose fiber-based substrate with a binder or latex.

[0016] Furthermore, the base paper for the adhesive has a breaking point elongation and a breaking point load sufficient to prevent tearing and breaking in the converting process when small rolls of the adhesive tape are produced. Further features and advantages of the present technology will become apparent from the following description of some embodiments.

Brief Description of the Drawings

[0017]

Figure 1

Mode for Carrying Out the Invention

[0018] Embodiment The present invention is illustrated in a specific embodiment with reference to FIG. 1, and provides a cellulose fiber-based translucent or transparent adhesive tape base paper, which includes a cellulose fiber-based substrate 7 containing highly refined cellulose-based fibers having a pulp freeness of °SR70 to 90 using the Schopper-Riegler method. The substrate 7 has a first surface and a second surface on the opposite side of the first surface. A release layer 5 is provided on the first surface of the cellulose fiber-based substrate, and the cellulose fiber-based substrate 7 has an opacity index in the range of 13 to 40%.

[0019] In this context, being translucent or transparent in relation to materials such as cellulose fiber-based substrates or adhesive tapes means that the material has an opacity index in the range of 13 to 40% in accordance with the NFQ03-006 standard. Thus, in some embodiments, the cellulose fiber-based substrate has an opacity index in the range of 13 to 40%. In some embodiments, the opacity index can be in the range of 15 to 20%. In some embodiments, the opacity index can be in the range of 40 to 20%. In other embodiments, the opacity index can be in the range of 40 to 30%, and in other embodiments, the opacity index can be in the range of 30 to 20%.

[0020] In the present disclosure, the adhesive tape base paper includes a cellulose fiber-based substrate and a release layer on the first surface of the cellulose fiber-based substrate. The "adhesive tape" refers to an adhesive tape base paper containing an adhesive layer, and the adhesive layer is applied on the second surface of a cellulose fiber-based substrate or on an optional primer layer disposed on the second surface of the cellulose fiber-based substrate before receiving the adhesive layer.

[0021] Cellulosic fibers or cellulose fibers refer to fibers composed of cellulose or derived from cellulose. Cellulosic fibers can be selected from the group consisting of kraft pulp fibers, sulfite pulp fibers, chemically treated fibers, mechanically treated pulp fibers, chemo-thermomechanical pulp fibers, regenerated cellulosic fibers, and combinations thereof. Typically, cellulosic fibers include bleached pulp fibers. Advantageously, the use of cellulosic fibers enables the repulping and / or recycling of the base paper substrate and, depending on the types of release agents and adhesives used, the repulping and / or recycling of the adhesive tape. Further, this base paper is bio-based.

[0022] As used herein, highly refined cellulosic fibers may refer to cellulosic fibers, and the pulp freeness of the fibers can be in the range of 70-90°SR, preferably 80-90°SR, when measured using a Schopper-Riegler (SR) freeness tester. This high level of refining enables the adhesive tape paper to have the desired transparency required for use as office tape. More specifically, a pulp freeness of °SR 70-90 allows the adhesive tape base paper to have an opacity in the range of 13-40%.

[0023] In some embodiments, the amount of refining can also be measured based on the weight percentage of secondary fines in the highly refined cellulosic fibers. In some embodiments, the highly refined cellulosic fibers can contain more than 35% by weight of secondary fines based on the total weight of the highly refined cellulosic fibers.

[0024] Preferred non-limiting examples of highly refined cellulosic fibers include highly refined softwood fibers, highly refined hardwood fibers, regenerated cellulosic fibers such as lyocell fibers, and combinations thereof. Preferred highly refined cellulosic fibers are bleached softwood fibers, such as northern bleached softwood kraft (NBSK) fibers and / or southern bleached softwood kraft (SBSK) fibers.

[0025] Advantageously, the proportion of highly refined cellulosic fibers in the cellulosic fiber-based substrate 7 can be 100%. However, in some embodiments, the fibers of the cellulosic fiber-based substrate 7 can contain up to 5%, preferably up to 2%, of other fibers than the highly refined cellulosic fibers having a pulp freeness of °SR 70-90 using the Schopper-Riegler method. The fibers can include cellulosic fibers and / or synthetic fibers having a pulp freeness of less than °SR 70 using the Schopper-Riegler method, preferably cellulosic fibers. In the case of synthetic fibers, on the one hand, in order to maintain biodegradability, and on the other hand, when the synthetic fiber content exceeds 20%, the amount needs to be limited because the tape becomes difficult to tear. Preferably, the amount of synthetic fibers can be up to 2%. Most preferably, the cellulosic fiber-based substrate 7 consists of highly refined cellulosic fibers having a pulp freeness of °SR 70-90 using the Schopper-Riegler (SR) method.

[0026] Synthetic fibers generally refer to fibers made from fiber-forming substances containing polymers synthesized from chemical compounds. When present, preferred non-limiting examples of synthetic fibers can include polyamide fibers, polyester fibers, polyvinyl alcohol fibers, polylactic acid fibers, polyhydroxyalkanoate fibers, polyvalerate, and polybutyrate fibers, as well as mixtures thereof. When used, synthetic fibers preferably have a length of up to 6 mm. Synthetic fibers can also have a thickness of 0.5 to 2.0 dtex.

[0027] In some embodiments, the highly refined cellulosic fibers can include softwood fibers, hardwood fibers, or combinations thereof. In some embodiments, the highly refined cellulosic fibers can include 60 - 100%, preferably 75 - 95% softwood fibers, and 0 - 40%, more preferably 5 - 25% hardwood fibers. In other embodiments, the highly refined cellulosic fibers can include 80 - 90% softwood fibers and 10 - 20% hardwood fibers. In other embodiments, the highly refined cellulosic fibers can include only softwood fibers and may not include hardwood fibers. Specifically, softwood fibers contribute to the improvement of mechanical properties due to their high refinement level. Furthermore, hardwood fibers improve sheet formability and paper smoothness. When broke is used in the fiber composition, these broke are highly refined with fresh fibers.

[0028] In some embodiments, the proportion of the highly refined cellulosic fibers can include 75 - 95%, preferably 80 - 90% softwood fibers. In some embodiments, the proportion of the highly refined cellulosic fibers can include 5 - 25%, preferably 10 - 20% hardwood fibers.

[0029] In some embodiments, the cellulose fiber-based substrate 7 is 30 - 60 g / m 2 , preferably about 35 - 45 g / m 2It may have a basis weight. The basis weight of the cellulose fiber-based substrate 7 is an important parameter in order to enable having a thin adhesive tape. Further, it should be noted that when the basis weight is too heavy, the opacity of the cellulose fiber-based substrate 7 increases.

[0030] In some preferred embodiments, the cellulose fiber-based substrate 7 comprises or is a transparent or translucent cellulose fiber-based substrate or paper that has been calendered or supercalendered. Calendering refers to a finishing process in which the cellulose fiber-based substrate 7 passes through calender rollers at high temperature and high pressure to smooth the substrate.

[0031] The adhesive tape base paper may include a release layer 5 on the first surface of the cellulose fiber-based substrate 7. The release layer 5 may contain a release agent applied in an amount of 0.05 to 5 g / m 2 preferably in an amount of 0.05 to 2 g / m 2 Due to the smooth and closed surface of the cellulose fiber-based substrate 7 containing highly refined cellulose fibers, the amount of the release agent is low but can still be very efficient. Preferably, the adhesive tape has a release force of 10 to 500 cN / cm, preferably 50 to 250 cN / cm, measured according to the STM 3 FINAT test method standard.

[0032] In an embodiment, the release layer 5 may contain a release agent selected from the group consisting of silicone, fluorinated silicone, silicone-copolymer, fluorocarbon, acrylic acetate, acrylic, styrene acrylic, vinyl acetate, polyvinyl acetate, polycarbamate, polyolefin release agent, polyurethane, synthetic resin emulsion, and combinations thereof. Preferably, the release agent is selected from the group consisting of silicone, fluorinated silicone, silicone-copolymer, acrylic acetate, acrylic, and styrene acrylic.

[0033] In some embodiments, the cellulose fiber-based adhesive tape base paper includes a primer layer 9 on the second surface of the cellulose fiber-based substrate 7. The primer layer 9 is typically applied on the cellulose fiber-based substrate 7 in an amount of 0.5 to 3 g / m 2 and preferably in an amount of 1 to 2 g / m 2 , for example, in an amount of about 1 g / m 2 of a primer agent. In some embodiments, when the release agent is selected from silicones, the coating amount of this release agent is preferably 0.4 to 0.8 g / m 2 . In other embodiments, when the release agent is selected from acrylates, the coating amount of this release agent is preferably 1.0 to 2.0 g / m 2 .

[0034] When present, the amount of the primer agent depends on the structure of the cellulose fiber-based substrate 7 and the type of any optional other agents used. The primer agent is generally used to ensure good compatibility / affinity between the cellulose fiber-based substrate 7 of the adhesive tape and the adhesive used. However, the compatibility / affinity between the cellulose fiber-based base paper 7 or the base papers of the present invention may be sufficient without adding the primer layer 9.

[0035] When present, the primer layer 9 typically includes a primer agent selected from the group consisting of acrylics, styrene acrylates, polyethylene imines, synthetic resin emulsions, polyurethanes, vinyl-based polymers, modified starches, and mixtures thereof. Preferably, the primer agent is selected from acrylics or vinyl-based polymers.

[0036] In some embodiments, the adhesive tape base paper has a thickness of 25 to 60 μm, preferably 35 to 50 μm, measured in accordance with the ISO 534 standard. Specifically, such a thickness is close to one of the existing plastic-based office tapes and also enables having a small roll. Such a thickness also enables the presence of this tape to be hardly noticeable during use. Furthermore, the low thickness of the adhesive tape base paper also enables this base paper to have a very low opacity.

[0037] Preferably, the adhesive tape base paper has a dry tensile strength in the machine direction (MD) of 2 to 3 kN / m, measured in accordance with the ISO 1924-2 standard. According to some embodiments, the adhesive tape base paper has a dry tensile strength of 2 to 4.5 kN / m, preferably 3 to 4 kN / m, in the machine direction when measured in accordance with the ISO 1924-2 standard. Such a tensile strength in the MD enables the adhesive tape base paper to be unwound without breakage or tearing. Furthermore, such a tensile strength prevents problems that may occur in the converting process, specifically enabling the machine speed to be maintained in the converting process, specifically when applying the adhesive layer 11.

[0038] In some embodiments, the adhesive tape base paper 7 has a dry elongation of 2 to 4% in the machine direction and 5 to 15% in the cross direction when measured in accordance with the ISO 1924-2 standard. The dry elongation prevents problems that may occur in the converting process, particularly when the adhesive layer 11 is applied to the adhesive tape base paper 7, and also when the adhesive tape base paper is unwound and cut into small rolls to form the adhesive tape for packaging or office / stationery use.

[0039] In some embodiments, the adhesive tape base paper 7 has a dry breaking load at the breaking point of 45 to 100 N / 15 mm in the machine direction and 15 to 40 N / 15 mm in the cross direction when measured in accordance with the ISO 12625-4 standard.

[0040] In some embodiments, the adhesive tape base paper 7 has a Bekk smoothness of 200 to 10,000 seconds on the upper surface and 200 to 4,000 seconds on the lower surface when measured in accordance with the ISO 5627 standard.

[0041] In some embodiments, the adhesive tape base paper 7 has an upper surface Bekk smoothness of 2,000 to 9,600 seconds and a lower surface Bekk smoothness of 1,000 to 3,000 seconds when measured in accordance with the ISO 5627 standard. In other embodiments, the adhesive tape base paper may have an upper surface roughness of 500 to 900 seconds and a lower surface roughness of 200 to 500 seconds when measured in accordance with the ISO 5627 standard.

[0042] The adhesive tape base paper 7 is produced in a jumbo roll, that is, a roll with a width exceeding 1 meter and a length of several hundred meters. The adhesive tape base paper may be coated with the release layer 5, or this may be done at a later stage, but this release layer 5 must be present on the adhesive tape base paper 7 before the adhesive layer 11 is applied. To apply the adhesive layer 11, the jumbo roll of the adhesive tape base paper 7 is unwound, and the adhesive layer is coated on the surface of the adhesive tape base paper 7 on the opposite side of the release layer 5. Then, the adhesive jumbo roll is wound up and stored. To apply the adhesive layer 11, the jumbo roll is unwound at a speed of about 100 to 200 m / min. In order to prevent tearing and breaking during the application of the adhesive layer, the adhesive tape base paper 7 needs to have the mechanical properties presented above from here.

[0043] To convert the adhesive jumbo roll into small rolls of tape, a cutting process is carried out. To perform this cutting process, the adhesive jumbo roll is cut in width and length and wound onto small rolls at the end of the cutting process to form adhesive tape for packaging or for use as office / supplies tape. This cutting process performs several unwinding processes of the adhesive jumbo roll. Typically, the cutting process is carried out at a speed of 150 - 200 m / min and stopped after the desired length of the final tape is obtained. Therefore, the base paper needs to maintain this kind of tension to prevent tearing and breaking during the converting / cutting stage.

[0044] In some embodiments, the adhesive tape base paper may have a dry tensile strength in the cross direction (CD) of 0.5 - 1.5 kN / m, measured according to the ISO 1924-2 standard. In some embodiments, the adhesive tape base paper may have a dry tensile strength in the cross direction of 0.5 - 2 kN / m when measured according to the ISO 1924-2 standard.

[0045] Preferably, the adhesive tape base paper has an edge tear starter lap value of 1 - 20 N / 15 mm, preferably 5 - 15 N / 15 mm, measured according to the TAPPI T 470 om-89 standard. Such an edge tear starter lap value enables the adhesive tape base paper to be torn directly by hand without the need for a tape dispenser.

[0046] The pressure-sensitive adhesive tape base paper may have a porosity value. As used herein, porosity refers to the porosity measured according to the ISO 5636-3 standard. Therefore, as used herein, porosity refers to the Bendsten porosity, which is a measure of the air flow (i.e., air permeability) through the pores of the medium. The porosity of the pressure-sensitive adhesive base paper and the pressure-sensitive adhesive tape is measured using a Bendtsen porosity tester that calculates the porosity by forcing air through the sheet and measuring the flow rate according to ISO standard 5636-3. In a preferred embodiment, the porosity value of the cellulose fiber-based pressure-sensitive adhesive tape base paper and the pressure-sensitive adhesive tape is about 0.3 to 0.5 ml / min.

[0047] The pressure-sensitive adhesive tape base paper may further include an adhesive layer 11 containing a pressure-sensitive adhesive. The adhesive layer 11 is preferably on the second surface of the cellulose fiber-based substrate 7 or on the primer layer 9, in an amount of 5 to 30 g / m 2 , preferably 15 to 20 g / m 2 , and in some embodiments, about 20 g / m 2 is applied. To obtain the final tape, the adhesive layer 11 is applied. FIG. 1 shows an example of a final tape including an adhesive layer 11 applied on a primer layer 9 disposed on the second surface of a cellulose fiber-based substrate 7 before receiving the adhesive layer 11.

[0048] Preferably, the adhesive layer 11 includes a pressure-sensitive adhesive polymer selected from the group consisting of rubber-based polymers, vinyl acetate and ethylene-vinyl acetate polymers, polyolefins, polyamides, polyesters, polyurethanes, styrene block copolymers, epoxy resins, and combinations thereof, preferably hot melt adhesives such as natural rubber-based polymers and acrylic-based polymers.

[0049] The pressure-sensitive adhesive tape base paper of the present invention has a high content of bio-based materials. Typically, the content of the bio-based material is at least 70% by weight, preferably at least 80% by weight, more preferably at least 90% by weight of the pressure-sensitive adhesive tape base paper.

[0050] A method for producing a base paper for a cellulose fiber-based adhesive tape is further described herein. The method may include: a) providing or producing a cellulose fiber-based substrate 7 comprising highly refined cellulose-based fibers having a pulp freeness of °SR 70 to 90 using the Schopper-Riegler method, the substrate 7 having a first surface and a second surface opposite the first surface; b) applying a release layer 5 on the first surface of the cellulose fiber-based substrate 7; and c) optionally applying a primer layer 9 on the second surface of the cellulose fiber-based substrate 7.

[0051] To produce the cellulose fiber-based substrate 7, a certain amount of cellulose fibers is first provided. The cellulose fibers can be of any type disclosed herein, including but not limited to hardwood fibers, softwood fibers, and combinations thereof. If waste paper is used, these waste papers are provided at this stage. Next, the cellulose fibers can be subjected to a refining process to obtain highly refined cellulose-based fibers. The refining process can include imparting energy (i.e., shear, fibrillation) to the fibers to reduce their length and thickness. When the refining process is complete, the highly refined cellulose-based fibers have a degree of refining, which can be measured using a Schopper-Reigler (SR) freeness tester. As described above and in the claims, a preferred degree of refining can be at least 70°, more preferably at least 75°, and most preferably at least 80°. As disclosed above, the amount of refining can also be measured based on the weight percentage of secondary fines in the highly refined cellulose-based fibers. If present, a certain amount of synthetic fibers and / or cellulose fibers having a pulp freeness of less than 70°SR using the Schopper-Riegler method can be added to the highly refined cellulose-based fibers at the completion of the refining process.

[0052] The cellulose fiber-based substrate 7 can be formed from an aqueous suspension of highly refined cellulose fibers on a conventional papermaking machine. Advantageously, the cellulose fiber-based substrate 7 is supercalendered either offline or online. The release layer 5 can be applied onto the first surface of the cellulose fiber-based substrate 7. Optionally, a primer layer 9 can be applied onto the second surface of the cellulose fiber-based substrate 7. The release layer 5 and / or the primer layer 9 can be applied before this calendering or supercalendering step if these layers are applied online, or after this calendering or supercalendering step if these layers are applied offline.

[0053] Preferably, the release layer 5 and the optional primer layer 9 are applied by a technique selected from roll-to-roll coating, blade coating, spray coating, Mayer rod coating, air knife coating, direct gravure, offset gravure, reverse gravure, deep coating, smooth roll coating, curtain coating, bead coating, slot coating, twin HSM coating, film press coating, size press coating, and / or transfer film method. More preferably, the release layer 5 and the optional primer layer 9, if present, are applied onto the base paper by a Mayer rod or by curtain coating.

[0054] In one embodiment, the method further includes applying an adhesive layer 11 onto the second surface of the cellulose fiber-based substrate 7 or onto the primer layer 9, and the adhesive layer 11 is applied by a technique selected from roll-to-roll coating, blade coating, spray coating, Mayer rod coating, air knife coating, direct gravure, offset gravure, reverse gravure, deep coating, smooth roll coating, curtain coating, bead coating, slot coating, twin HSM coating, film press coating, size press coating, and / or transfer film method.

[0055] The production of the cellulose fiber-based adhesive base paper can be carried out on a single production line. The cellulose fiber-based substrate 7 is prepared from an aqueous suspension of highly refined cellulose fibers and then coated with the release layer 5. The primer layer 9, if present, can also be coated online.

[0056] It should be understood that the disclosed embodiments of the present invention are not limited to the specific structures, process steps, or materials disclosed herein, but extend to their equivalents as would be recognized by those of ordinary skill in the relevant art. It should also be understood that the terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting.

[0057] A reference throughout this specification to one embodiment or to an embodiment means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. For example, when referring to a numerical value using terms such as about, or substantially, the exact numerical value is also disclosed.

[0058] As used herein, a plurality of items, structural elements, components, and / or materials may be presented in a common list for convenience. However, these lists should be construed such that each member of the list is individually identified as a separate and unique member. Thus, individual members of such lists should not be construed as being de facto equivalents of any other member of the same list based solely on their presentation in a common group without an indication to the contrary. Additionally, various embodiments and examples of the present invention may be referred to herein with alternative of their various components. It is understood that such embodiments, examples, and alternatives should not be construed as being de facto equivalents of each other, but rather as separate and autonomous representations of the present invention.

[0059] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details such as examples of length, width, shape, etc. are provided to provide a thorough understanding of the embodiments of the present invention. However, those skilled in the relevant art will recognize that the present invention may be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the present invention.

[0060] Experiment Measurement method Pulp freeness: Schopper-Reiegler method and Schopper-Reiegler (SR) freeness tester Opacity index: NFQ 03-006 standard Peel strength: STM 3 FINAT test method standard Thickness: ISO534 standard Tensile strength: ISO1924-2 standard Elongation: ISO1924-2 standard Breaking point load: ISO12625-4 standard Edge tear star lap: TAPPI T 470 om-89 standard Bendtsen Porosity: According to ISO 5636-3 standard, the value is expressed in mL / min Gurley Porosity: According to ISO 5636-5 standard, the value is expressed in seconds Bekk Smoothness: According to ISO 5627 standard Roughness: According to ISO 8791-1 standard Hand Tear: According to ISO 1974 standard Grammage or Basis Weight: According to ISO 536 standard Tear: According to ISO 1974 standard.

[0061] Example 1. Cellulose Fiber-based Substrate 7 In some embodiments, the cellulose fiber-based substrate 7 may have the following properties.

[0062] [Table 1]

[0063] The fibers in the above-specified cellulose fiber-based substrate 7 are highly refined cellulose-based fibers having a pulp freeness of °SR 70-90 using the Schopper-Riegler method. In the examples presented above, the cellulose fiber-based substrate 7 does not contain a release layer 5. This cellulose fiber-based substrate 7 is coated with an adhesive layer 11, and the adhesive layer 11 is present on the second surface of the cellulose fiber-based substrate 7 in an amount of 20 g / m 2 by dry weight, and the adhesives used are, for example, Primal® PS83D, PS83B, or PS2020 sold by Dow, or Ichemco Tackwhite® A39, or A238, etc., which are aqueous acrylic adhesives. For the measurements above, the cellulose fiber-based substrate does not contain a primer layer.

[0064] The comparative example is made of biaxially oriented polypropylene (BOPP), a film having a thickness of 35 μm, which is used to produce a pressure-sensitive tape sold by 3M under the name Scotch (registered trademark) 550. This Scotch (registered trademark) 550 tape includes a release layer made of an acrylic copolymer and an adhesive layer made of an aqueous acrylic pressure-sensitive adhesive such as PS8913 sold and manufactured by Dow, for example.

[0065] Example 2. Release properties The base material 3 disclosed above from here up is coated on its first surface with 0.3 g / m 2 of silicone release and on its second surface with 20 g / m 2 of two different acrylic adhesives to form a pressure-sensitive tape. The release properties of these pressure-sensitive tapes are measured and compared with the release properties of Scotch550 (registered trademark) manufactured and sold by 3M and with Tesa Tape7475 corresponding to the reference tape for silicone-treated paper. The release properties are measured based on a revised version of the Finat test method 3 standard using a standard Finat test roll (2 kg), and the test is carried out for only 20 minutes instead of 20 hours (required by the standard), and there is no long-term contact with weight. Similar to the previous example, the adhesive layer 11 includes an aqueous acrylic adhesive such as Primal (registered trademark) PS83D, PS83B, or PS2020 sold by Dow, or Ichemco Tackwhite (registered trademark) A39 or A238. The obtained release properties are summarized in the following table.

[0066]

Table 2

[0067] Example 3. Cellulose fiber-based semi-transparent or transparent pressure-sensitive tape 1 This first cellulose fiber-based semi-transparent or transparent pressure-sensitive tape 1 is made of a cellulose fiber-based base material 7, a release layer 5, and an adhesive layer 11.

[0068] The cellulose fiber-based substrate 7 is made from 83% by weight of softwood fibers and 17% by weight of waste paper, based on the total weight of the fibers. The fibers are mixed with water and then refined at 70° SR. The refined fibers are then disposed on the forming table of a paper machine, and the mixture is dewatered and dried to form a paper web. In the following description, the back surface of the cellulose fiber-based substrate 7 corresponds to the surface in contact with the forming table, and the upper surface is the opposite surface of this paper web.

[0069] Next, the cellulose fiber-based substrate 7 is coated with a release layer 5. According to this embodiment, the release layer 5 is made from a silicone coating. This silicone coating is disposed on the upper surface of the cellulose fiber-based substrate 7 in an amount of 0.6 g / m 2 in terms of dry weight. Typically, this silicone coating is applied by a Mayer rod. Next, the cellulose fiber-based substrate 7 having the release layer 5 is calendered and wound up with a jumbo roll. The jumbo roll generally has a width exceeding 1 m and a length of several hundred meters according to the width of the forming table of the paper machine.

[0070] The cellulose fiber-based substrate 7 is 39 g / m when measured according to the ISO 536 standard. 2When measured according to the grammage of tsubo, it has a thickness of 39 μm. Further, the cellulose fiber-based substrate has an opacity of 40% when measured according to the NFQ03-006 standard. This opacity of the cellulose fiber-based substrate 7 is obtained by the fiber refining and calendering processes. This cellulose fiber-based substrate has a Bekk smoothness of 880 seconds on the upper surface and 228 seconds on the lower surface when measured according to the ISO5627 standard. Further, the cellulose fiber-based substrate 7 has a tear of 213 mN in the machine direction and 259 mN in the cross direction when measured according to the ISO1974 standard. When the cellulose fiber-based substrate 7 is cut into small rolls, the tear in the machine direction must be very high in order to prevent tearing problems in subsequent converting processes. The cellulose fiber-based substrate 7 has a dry tensile strength of 4.0 kN / m in the machine direction and 2.0 kN / m in the cross direction when measured according to the ISO1924-2 standard. The dry tensile strength in the machine direction is an important factor for preventing breakage in the converting process when the cellulose fiber-based substrate 7 is unwound and coated with the adhesive layer 11, and the adhesive jumbo roll is cut into small rolls to form the cellulose fiber-based semi-transparent or transparent adhesive tape 1. Further, it should be noted that the dry tensile strength in the cross direction must not be very low in order for the user to be able to cut the cellulose fiber-based semi-transparent or transparent adhesive tape by hand. The cellulose fiber-based substrate 7 has a breaking point load of 60 N / 15 mm in the machine direction and 30 N / 15 mm in the cross direction when measured according to the ISO12625-4 standard. In particular, the breaking point load in the machine direction prevents tearing and breakage during the converting process while the adhesive layer 11 is disposed on the cellulose fiber-based substrate 7 and during the cutting process performed to provide small tape rolls. Next, the cellulose fiber-based substrate 7 has a dry elongation of 2.8% in the machine direction and 8.2% in the cross direction when measured according to the ISO1924-2 standard. The dry elongation in the machine direction absorbs fluctuations in the tension applied during the cutting process and helps to form small rolls.

[0071] According to this embodiment, in order to enable the fixing of the adhesive layer 11, since the Bekk smoothness thereof is sufficiently low, there is no need to place a primer on the back surface of the cellulose fiber-based substrate 7. In other words, the back surface of the cellulose fiber-based substrate 7 is sufficiently rough to enable the fixing of the adhesive layer 11. According to this embodiment, the adhesive layer 11 is an aqueous acrylic adhesive coating on the back surface of the cellulose fiber-based substrate 7 in an amount of 20 g / m 2 is.

[0072] Example 4. Cellulose Fiber-Based Translucent or Transparent Adhesive Tape 2 This second cellulose fiber-based translucent or transparent adhesive tape is made of a cellulose fiber-based substrate 7, a release layer 5, a primer layer 9, and an adhesive layer 11.

[0073] The cellulose fiber-based substrate 7 is made of 75% by weight of softwood fibers based on the total weight of the fibers and 25% by weight of hardwood fibers based on the total weight of the fibers. The fibers are mixed with water and then refined at 85° SR. Then, the refined fibers are disposed on the forming table of a paper machine, and the mixture is dehydrated and dried to form a paper web. Then, this paper web is supercalendered to produce the cellulose fiber-based substrate 7. In the following description, the back surface of the cellulose fiber-based substrate 7 corresponds to the surface in contact with the forming table, and the upper surface is the opposite surface of this paper web.

[0074] Next, the cellulose fiber-based substrate 7 is coated with the release layer 5. According to this embodiment, the release layer 5 is made of a silicone coating. This silicone coating is disposed on the upper surface of the cellulose fiber-based substrate 7 in an amount of 0.6 g / m 2 by dry weight. Typically, this silicone coating is applied by a Mayer rod. Then, the cellulose fiber-based substrate 7 having the release layer 5 is wound up with a jumbo roll.

[0075] The primer layer 9 can be applied online or offline on the back surface of the cellulose fiber-based substrate 7. According to this embodiment, the primer layer 9 is disposed online on the cellulose fiber-based substrate 7, and this primer is an acrylic polymer. The coating of the primer layer 9 is carried out before the supercalendering process and can be carried out before or after the coating of the release layer 5. Typically, the primer layer 9 is disposed on the back side of the cellulose fiber-based substrate 7 by curtain coating. The primer layer 9 is coated on the back surface of the cellulose fiber-based substrate 7 in an amount of 1 g / m 2 by dry weight.

[0076] The cellulose fiber-based substrate 7 has a basis weight of 39 g / m when measured according to ISO 536 standard. 2When measured according to the grammage of the tsubo, it has a thickness of 31 μm. Further, the cellulose fiber-based substrate has an opacity of 15% when measured according to the NFQ03-006 standard. This opacity of the cellulose fiber-based substrate 7 is obtained by the fiber refining and supercalendering processes. This cellulose fiber-based substrate has a Bekk smoothness of 3200 seconds on the upper surface and 1200 seconds on the lower surface when measured according to the ISO5627 standard. Further, the cellulose fiber-based substrate 7 has a tear of 243 mN in the machine direction and 278 mN in the cross direction when measured according to the ISO1974 standard. When the cellulose fiber-based substrate 7 is cut into small rolls, the tear in the machine direction must be very high in order to prevent tearing problems in subsequent converting processes. The cellulose fiber-based substrate has a dry tensile strength of 3.5 kN / m in the machine direction and 1.4 kN / m in the cross direction when measured according to the ISO1924-2 standard. The dry tensile strength in the machine direction is an important factor for preventing breakage in the converting process when the cellulose fiber-based substrate 7 is unwound and cut into small rolls to form a semi-transparent or transparent adhesive tape based on cellulose fibers. Further, it should be noted that the dry tensile strength in the cross direction must be very low in order for the user to be able to cut the semi-transparent or transparent adhesive tape based on cellulose fibers by hand. The cellulose fiber-based substrate 7 has a breaking point load of 52 N / 15 mm in the machine direction and 21 N / 15 mm in the cross direction when measured according to the ISO12625-4 standard. In particular, the breaking point load in the machine direction prevents tearing and breakage during the converting process while the adhesive layer is disposed on the adhesive tape base paper and during the cutting process performed to provide small tape rolls. The mechanical properties of this cellulose fiber-based substrate 7 are slightly lower than those of the previous example due to the higher refining of the fibers. Further, the decrease in the content of softwood fibers slightly reduces the mechanical properties, but the addition of hardwood fibers helps in sheet formation on the paper machine and thus enables a reduction in the roughness of the cellulose fiber-based substrate 7.Next, the cellulose fiber-based substrate 7 has a dry elongation of 2.5% in the machine direction and 14.1% in the cross direction when measured according to ISO 1924-2 standard. The dry elongation in the machine direction helps to absorb the fluctuations in the tension applied during the cutting process and form small rolls.

[0077] According to this embodiment, the primer layer 9 is coated on the back surface of the cellulose fiber-based substrate 7 because its Bekk smoothness is high enough to enable the adhesion of the adhesive layer 11. In fact, the primer layer 9 is intended to chemically interact with the adhesive layer 11, and this primer layer 9 aims to prevent the problem of the adhesion of the adhesive layer 11 due to the very smooth surface of the cellulose fiber-based substrate 7. However, the very high smoothness of the paper allows for less light scattering on the surface of the cellulose fiber-based substrate 7, thus enabling a reduction in opacity. According to this embodiment, the adhesive layer 11 is an aqueous acrylic adhesive coating on the back surface of the cellulose fiber-based substrate 7 in an amount of 18 g / m 2 .

[0078] Example 5. Cellulose fiber-based semi-transparent or transparent adhesive tape 3 This third cellulose fiber-based semi-transparent or transparent adhesive tape is made of a cellulose fiber-based substrate 7, a release layer 5, and an adhesive layer 11.

[0079] The cellulose fiber-based substrate 7 is made of 83% by weight of softwood fibers based on the total weight of the fibers and 17% by weight of waste paper based on the total weight of the fibers. The fibers are mixed with water and then refined at 75° SR. Then, the refined fibers are disposed on the forming table of a paper machine, and the mixture is dehydrated and dried to form a paper web. In the following description, the back surface of the cellulose fiber-based substrate 7 corresponds to the surface in contact with the forming table, and the upper surface is the opposite surface of this paper web.

[0080] Next, the cellulose fiber-based substrate 7 is coated with the release layer 5. According to this embodiment, the release layer 5 is made from a vinyl acrylic copolymer coating. This vinyl acrylic copolymer coating is disposed on the upper surface of the cellulose fiber-based substrate 7 in an amount of 1.7 g / m 2 by dry weight. Typically, this vinyl acrylic copolymer coating is applied by a Mayer rod. Next, the cellulose fiber-based substrate 7 having the release layer 5 is calendered and wound up with a jumbo roll. The jumbo roll generally has a width exceeding 1 m and a length of several hundred meters according to the width of the forming table of the paper machine.

[0081] The cellulose fiber-based substrate 7 is 39 g / m when measured according to the ISO536 standard. 2When measured according to the grammage of tsubo, it has a thickness of 39 μm as measured according to the ISO 534 standard. Further, the cellulose fiber-based substrate has an opacity of 28% when measured according to the NFQ03-006 standard. This opacity of the cellulose fiber-based substrate 7 is obtained by the fiber refining and calendering processes. This cellulose fiber-based substrate has a Bekk smoothness of 880 seconds on the upper surface and 228 seconds on the lower surface when measured according to the ISO 5627 standard. Further, the cellulose fiber-based substrate 7 has a tear of 213 mN in the machine direction and 259 mN in the cross direction when measured according to the ISO 1974 standard. When the cellulose fiber-based substrate 7 is cut into small rolls, the tear in the machine direction must be very high in order to prevent tearing problems in subsequent converting processes. The cellulose fiber-based substrate 7 has a dry tensile strength of 4.0 kN / m in the machine direction and 2.0 kN / m in the cross direction when measured according to the ISO 1924-2 standard. The dry tensile strength in the machine direction is an important factor for preventing breakage in the converting process when the cellulose fiber-based substrate 7 is unwound and cut into small rolls to form the cellulose fiber-based semi-transparent or transparent adhesive tape 1. Further, it should be noted that the dry tensile strength in the cross direction must be very low in order for the user to be able to cut the cellulose fiber-based semi-transparent or transparent adhesive tape 1 by hand. The cellulose fiber-based substrate 7 has a breaking point load of 60 N / 15 mm in the machine direction and 30 N / 15 mm in the cross direction when measured according to the ISO 12625-4 standard. In particular, the breaking point load in the machine direction prevents tearing and breakage during the converting process while the adhesive layer is disposed on the adhesive tape base paper and during the cutting process performed to provide small tape rolls. Next, the cellulose fiber-based substrate 7 has a dry elongation of 2.8% in the machine direction and 8.2% in the cross direction when measured according to the ISO 1924-2 standard. The dry elongation in the machine direction absorbs the tension fluctuations applied during the cutting process and helps to form small rolls.

[0082] According to this embodiment, in order to enable the fixing of the adhesive layer 11, since the Bekk smoothness thereof is sufficiently low, there is no need to place a primer on the back surface of the cellulose fiber-based substrate 7. In other words, the back surface of the cellulose fiber-based substrate 7 is sufficiently rough to enable the fixing of the adhesive layer 11. According to this embodiment, the adhesive layer 11 is an aqueous acrylic adhesive coating on the back surface of the cellulose fiber-based substrate 7 in an amount of 19 g / m 2 and is a cellulose fiber-based substrate 7.

[0083] Example 6. Cellulose fiber-based semi-transparent or transparent adhesive tape 4 This fourth cellulose fiber-based semi-transparent or transparent adhesive tape is made of a cellulose fiber-based substrate 7, a release layer 5, a primer layer 9, and an adhesive layer 11.

[0084] The cellulose fiber-based substrate 7 is made of 80% by weight of softwood fibers based on the total weight of the fibers and 20% by weight of hardwood fibers based on the total weight of the fibers. The fibers are mixed with water and then refined at 85° SR. Then, the refined fibers are disposed on the forming table of a paper machine, the mixture is dehydrated and dried to form a paper web. Then, this paper web is supercalendered to form the cellulose fiber-based substrate 7. In the following description, the back surface of the cellulose fiber-based substrate 7 corresponds to the surface in contact with the forming table, and the upper surface is the opposite surface of this paper web.

[0085] Next, the cellulose fiber-based substrate 7 is coated with the release layer 5. According to this embodiment, the release layer 5 is made of a vinyl acrylic copolymer coating. This vinyl acrylic copolymer coating is disposed on the upper surface of the cellulose fiber-based substrate 7 in an amount of 1.7 g / m 2 by dry weight. Typically, this vinyl acrylic copolymer coating is applied by a Mayer rod. Then, the cellulose fiber-based substrate 7 having the release layer 5 is wound up with a jumbo roll.

[0086] The primer layer 9 can be applied online or offline on the back surface of the cellulose fiber-based substrate 7. According to this embodiment, the primer layer 9 is disposed online on the cellulose fiber-based substrate 7. The coating of the primer layer 9 can be carried out before or after the supercalendering process and can be carried out before or after the coating of the release layer 5. Typically, the primer layer 9 is disposed on the back side of the cellulose fiber-based substrate 7 by curtain coating. The primer layer 9 is coated on the back surface of the cellulose fiber-based substrate 7 in an amount of 1 g / m 2 by dry weight.

[0087] The cellulose fiber-based substrate 7 has a basis weight of 39 g / m when measured according to the ISO 536 standard. 2When measured according to the grammage of JIS P 8112 and the ISO 534 standard, it has a thickness of 31 μm. Further, the cellulose fiber-based substrate has an opacity of 15% when measured according to the NFQ03-006 standard. The opacity of this cellulose fiber-based substrate 7 is obtained by the fiber refining and supercalendering processes. This cellulose fiber-based substrate has a Bekk smoothness of 3200 seconds on the upper surface and 1200 seconds on the lower surface when measured according to the ISO 5627 standard. Further, the cellulose fiber-based substrate 7 has a tear of 243 mN in the machine direction and 278 mN in the cross direction when measured according to the ISO 1974 standard. When the cellulose fiber-based substrate 7 is cut into small rolls, the tear in the machine direction must be very high in order to prevent tearing problems in subsequent converting processes. The cellulose fiber-based substrate has a dry tensile strength of 3.5 kN / m in the machine direction and 1.4 kN / m in the cross direction when measured according to the ISO 1924-2 standard. The dry tensile strength in the machine direction is an important factor for preventing breakage in the converting process when the cellulose fiber-based substrate 7 is unwound and cut into small rolls to form a cellulose fiber-based semi-transparent or transparent adhesive tape. Further, it should be noted that the dry tensile strength in the cross direction must be very low in order for the user to be able to cut the cellulose fiber-based semi-transparent or transparent adhesive tape by hand. The cellulose fiber-based substrate 7 has a breaking point load of 52 N / 15 mm in the machine direction and 21 N / 15 mm in the cross direction when measured according to the ISO 12625-4 standard. In particular, the breaking point load in the machine direction prevents tearing and breakage during the converting process while the adhesive layer is disposed on the adhesive tape base paper and during the cutting process performed to provide small tape rolls. The mechanical properties of this cellulose fiber-based substrate 7 are slightly lower than those of the previous example due to the higher refining of the fibers. Further, the decrease in the softwood fiber content slightly reduces the mechanical properties, but the addition of hardwood fibers helps in sheet formation on the paper machine and thus enables a reduction in the roughness of the cellulose fiber-based substrate 7.Next, the cellulose fiber-based substrate 7 has a dry elongation of 2.5% in the machine direction and 14.1% in the cross direction when measured according to the ISO 1924-2 standard. The dry elongation in the machine direction helps to absorb fluctuations in the tension applied during the cutting process and form small rolls.

[0088] According to this embodiment, the primer layer 9 is coated on the back surface of the cellulose fiber-based substrate 7 because its Bekk smoothness is sufficiently high to enable the adhesion of the adhesive layer 11. In fact, the primer layer 9 is intended to chemically interact with the adhesive layer 11, and this primer layer 9 aims to prevent problems with the adhesion of the adhesive layer 11 due to the very smooth surface of the cellulose fiber-based substrate 7. However, the very high smoothness of the paper allows for a reduction in opacity because there is less light scattering on the surface of the cellulose fiber-based substrate 7. According to this embodiment, the adhesive layer 11 is an aqueous acrylic adhesive coating on the back surface of the cellulose fiber-based substrate 7 in an amount of 20 g / m 2 6.

[0089] Embodiment Embodiments of the present invention include, namely, the following. 1. A cellulose fiber-based semi-transparent or transparent adhesive tape base paper, - A cellulose fiber-based substrate (7) comprising highly refined cellulose-based fibers having a pulp freeness of °SR 70 to 90 using the Schopper-Riegler method, the substrate (7) having a first surface and a second part on the opposite side of the first surface, the cellulose fiber-based substrate (7); A release layer (5) on the first surface of the cellulose fiber-based substrate (7); The cellulose fiber-based substrate (7) is a cellulose fiber-based semi-transparent or transparent adhesive tape base paper having an opacity index in the range of 13 to 40% according to the NFQ03-006 standard.

[0090] 2. The base paper for adhesive tape according to Embodiment 1, comprising a primer layer (9) on the second surface of the cellulose fiber-based substrate (7). 3. The primer layer (9) is coated on the cellulose fiber-based substrate (7) in an amount of 0.5 to 3 g / m 2 preferably 1 to 2 g / m 2 of the primer agent, and the base paper for adhesive tape according to Embodiment 2.

[0091] 4. The primer layer (9) contains a primer agent selected from the group consisting of acrylic, styrene acrylic, polyethyleneimine, synthetic resin emulsion, polyurethane, vinyl polymer, and mixtures thereof, and the base paper for adhesive tape according to Embodiment 2 or 3.

[0092] 5. The release layer (5) contains a release agent coated on the cellulose fiber-based substrate (7) in an amount of 0.05 to 5 g / m 2 preferably 0.05 to 2 g / m 2 of the release agent, and the base paper for adhesive tape according to any one of the preceding embodiments.

[0093] 6. The release layer (5) contains a release agent selected from the group consisting of silicone, fluorinated silicone, silicone-copolymer, fluorocarbon, acrylic acetate, acrylic, styrene acrylic, vinyl acetate, polyvinyl acetate, polycarbamate, polyolefin release agent, polyurethane, synthetic resin emulsion, and combinations thereof, and the base paper for adhesive tape according to any one of the preceding embodiments.

[0094] 7. The following features: - A thickness of 25 to 60 μm, preferably 35 to 50 μm, measured according to the ISO 534 standard, - A tear in the CD of 120 to 140 mN, preferably about 130 mN, measured according to the ISO 1974 standard, - A tensile strength in the MD of 2 to 3 kN / m, measured according to the ISO 1924-2 standard, and having at least one of these, or a combination thereof, and the base paper for adhesive tape according to any one of the preceding embodiments.

[0095] 8. The base paper for an adhesive tape according to any one of the preceding embodiments, wherein highly refined cellulose-based fibers contain 75 to 95%, preferably 80 to 90% of softwood fibers, and 5 to 25%, preferably 10 to 20% of hardwood fibers.

[0096] 9. The base paper for an adhesive tape according to any one of the preceding embodiments, wherein the cellulose fiber-based substrate (7) comprises or is a supercalendered transparent or translucent paper.

[0097] 10. The cellulose fiber-based substrate (7) has a basis weight of 30 to 60 g / m 2 , preferably about 35 to 45 g / m 2 The base paper for an adhesive tape according to any one of the preceding embodiments.

[0098] 11. On the second surface of the cellulose fiber-based substrate (7) or on the primer layer (9), preferably in an amount of 5 to 30 g / m 2 , more preferably about 20 g / m 2 The base paper for an adhesive tape according to any one of the preceding embodiments, further comprising an adhesive layer (11) containing a pressure-sensitive adhesive polymer applied in an amount.

[0099] 12. The base paper for an adhesive tape according to embodiment 11, wherein the adhesive layer (11) contains a pressure-sensitive adhesive polymer selected from the group consisting of rubber-based polymers, vinyl acetate and ethylene-vinyl acetate polymers, polyolefins, polyamides, polyesters, polyurethanes, styrene block copolymers, epoxy resins, and combinations thereof, preferably hot melt adhesives such as natural rubber-based polymers and acrylic-based polymers.

[0100] 13. A method for producing a cellulose fiber-based base paper for an adhesive tape according to any one of embodiments 1 to 10, comprising the following -Providing or producing a cellulose fiber-based substrate (7) comprising highly refined cellulose fibers having a pulp freeness of °SR 70 to 90 using the Schopper-Riegler method; -Coating a release layer (5) on a first surface of the cellulose fiber-based substrate (7); -Optionally coating a primer layer (9) on a second surface of the cellulose fiber-based substrate (7), comprising: The release layer (5) and the optional primer layer (9) are applied by a technique selected from roll-to-roll coating, blade coating, spray coating, Mayer rod coating, air knife coating, direct gravure, offset gravure, reverse gravure, deep coating, smooth roll coating, curtain coating, bead coating, slot coating, twin HSM coating, film press coating, size press coating, and / or transfer film method.

[0101] 14. Further comprising coating an adhesive layer (11) on the second surface of the cellulose fiber-based substrate (7) or on the primer layer (9), the adhesive layer (11) being applied by a technique selected from roll-to-roll coating, blade coating, spray coating, Mayer rod coating, air knife coating, direct gravure, offset gravure, reverse gravure, deep coating, smooth roll coating, curtain coating, bead coating, slot coating, twin HSM coating, film press coating, size press coating, and / or transfer film method, the method according to embodiment 13.

[0102] 15. Use of the adhesive tape base paper according to any one of embodiments 1 to 12 for preparing an adhesive tape for packaging or for use as an office / stationery tape. The foregoing embodiments are illustrative of the principles of the present invention in one or more specific applications. However, it will be apparent to those skilled in the art that numerous modifications can be made in form, usage, and details of implementation without exercising inventive faculty and without departing from the principles and concepts of the present invention. Therefore, the present invention is not intended to be limited except as defined by the claims set forth below.

[0103] The verbs "to comprise" and "to include" are used in this specification as non-limiting restrictions that do not require or exclude the presence of features not recited. The features recited in the dependent claims can be freely combined with each other unless otherwise explicitly specified. Further, it should be understood that the use of "a" or "an" throughout this specification, i.e., in the singular, does not exclude the plural.

[0104] Industrial Applicability At least some embodiments of the present invention find industrial applications in the adhesive tape industry. Adhesive tapes are used as packaging and office / stationery tapes.

[0105] List of References Patent Documents EP2841516B1 JP2000 / 086986A WO2019 / 096848A1 US2021 / 274831A1 EP3059344A1 CN108049249A EP1314769A1 JP2017 / 057515A JP2017 / 133132A Non-Patent Documents -

Claims

1. A cellulose fiber-based translucent or transparent adhesive tape base paper, - A cellulose fiber-based substrate (7) comprising highly refined cellulosic fibers having a pulp-freeness of °SR70 to 90 using the Schoper-Riegler method, wherein the substrate (7) has a first surface and a second portion opposite to the first surface, The cellulose fiber-based substrate (7) includes a release layer (5) on the first surface, The aforementioned highly refined cellulosic fibers consist of 60-100% coniferous fibers and 0-40% hardwood fibers. The cellulose fiber-based substrate (7) is a cellulose fiber-based translucent or transparent adhesive tape base paper having an opacity index in the range of 13 to 40% in accordance with the NFQ03-006 standard.

2. The adhesive tape base paper according to claim 1, comprising a primer layer (9) on a second surface of the cellulose fiber-based substrate (7).

3. The adhesive tape base paper according to claim 2, wherein the primer layer (9) comprises a primer selected from the group consisting of acrylic, styrene acrylic, polyethyleneimine, synthetic resin emulsion, polyurethane, vinyl polymer, and mixtures thereof.

4. The release layer (5) is applied to the cellulose fiber-based substrate (7) at a rate of 0.05 to 5 g / m². ２ In this amount, preferably 0.05 to 2 g / m ２ The adhesive tape base paper according to claim 1, comprising a release agent applied in an amount.

5. The adhesive tape base paper according to claim 1, wherein the release layer (5) comprises a release agent selected from the group consisting of silicone, fluorinated silicone, silicone copolymer, fluorocarbon, acrylic acetate, acrylic, styrene acrylic, vinyl acetate, polyvinyl acetate, polycarbamate, polyolefin release agent, polyurethane, synthetic resin emulsion, and combinations thereof.

6. The adhesive tape base paper according to claim 1, having a thickness of 25 to 60 μm, preferably 35 to 50 μm, as measured in accordance with ISO 534 standards.

7. The adhesive tape base paper according to claim 1, having a dry elongation of 2-4% in the mechanical direction and 5-15% in the transverse direction, as measured in accordance with the ISO 1924-2 standard.

8. The adhesive tape base paper according to Claim 1, having a breaking point dry load of 45 to 100 N / 15 mm in the mechanical direction and 15 to 40 N / 15 mm in the transverse direction, as measured according to ISO 12625-4 standard.

9. The adhesive tape base paper according to Claim 1, having at least one of the following Beck smoothness values, or a combination thereof, when measured according to ISO 5627 standards: 200 to 10,000 seconds on the top surface and 200 to 4,000 seconds on the back surface.

10. The adhesive tape base paper according to claim 1, wherein the highly refined cellulosic fibers comprise 75-95%, preferably 80-90%, of coniferous fibers and 5-25%, preferably 10-20%, of hardwood fibers.

11. The cellulose fiber-based substrate (7) is 30 to 60 g / m ２ Preferably about 35-45 g / m ２ The adhesive tape base paper according to claim 1, having the basis weight.

12. Preferably 5 to 30 g / m² is applied to the second surface of the cellulose fiber-based substrate (7) or to the primer layer (9). ２ Comfortably about 20 g / m ２ The adhesive tape base paper according to claim 2, further comprising an adhesive layer (11) containing a pressure-sensitive adhesive polymer, applied in an amount.

13. The adhesive tape base paper according to claim 12, wherein the adhesive layer (11) comprises a pressure-sensitive adhesive polymer selected from the group consisting of rubber-based polymers, vinyl acetate and ethylene-vinyl acetate polymers, polyolefins, polyamides, polyesters, polyurethanes, styrene block copolymers, epoxy resins, and combinations thereof, preferably hot melt adhesives such as natural rubber-based polymers and acrylic-based polymers.

14. A method for producing a cellulose fiber-based adhesive tape base paper according to any one of claims 1 to 11, the following: - A step of providing or producing a cellulose fiber-based substrate (7) having a pulp-freeness of °SR70 to 90 using the Schoper-Riegler method, wherein the highly refined cellulose fibers comprise 60 to 100% softwood fibers and 0 to 40% hardwood fibers, - A step of applying a release layer (5) onto the first surface of the cellulose fiber-based substrate (7), - The process includes the step of optionally applying a primer layer (9) onto the second surface of the cellulose fiber-based substrate (7), A method wherein the release layer (5) and the optional primer layer (9) are applied by a technique selected from roll-to-roll coating, blade coating, spray coating, Meyer rod coating, air knife coating, direct gravure, offset gravure, reverse gravure, deep coating, smooth roll coating, curtain coating, bead coating, slot coating, twin HSM coating, film press coating, size press coating, and / or transfer film method.

15. The method according to claim 14, further comprising the step of applying an adhesive layer (11) onto the second surface of the cellulose fiber-based substrate (7) or onto the primer layer (9), wherein the adhesive layer (11) is applied by a technique selected from roll-to-roll coating, blade coating, spray coating, Meyer rod coating, air knife coating, direct gravure, offset gravure, reverse gravure, deep coating, smooth roll coating, curtain coating, bead coating, slot coating, twin HSM coating, film press coating, size press coating, and / or transfer film method.

16. Use of the adhesive tape base paper according to any one of claims 1 to 13 for preparing adhesive tape for packaging or for use as office / stationery tape.

Images