Fiber-based transparent adhesive tape, method for production thereof and use thereof

Abstract

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

Description

Technical Field

[0001] The present invention relates to the field of adhesive tape industry, and in particular to adhesive tape base paper and adhesive tape for packaging and office / stationery purposes. According to a particular embodiment, the adhesive tape of the present invention can be based on transparent paper, wherein one side of the paper is coated with a release agent and the other side is optionally coated with a primer coating. The present invention also relates to a method for producing the adhesive tape base paper and the adhesive tape and its use in packaging or as an office / stationery tape. Background Art

[0002] Today, most packaging tapes and office / stationery tapes are based on plastics and are not biodegradable or compostable materials. As the current goal is to avoid the use of plastics and meet the requirements of the ban on single-use plastics, there is a need to provide sustainable solutions to provide new tapes with high bio-based content. In addition, plastic-based tapes known in the prior art are difficult to tear and a splitter must be used to tear or cut such tapes. Such splitters incur additional costs for the end user. In addition, the splitter may damage the tape or not fit the size of the tape.

[0003] Some fiber-based tapes have been disclosed. EP 2841516 B1 discloses a Washi tape impregnated with an adhesive composition. JP 2000086986A discloses a cellophane for forming an office tape. WO2019 / 096848 A1 discloses a tracing paper suitable for lamination and packaging applications. The tracing paper includes a coating to increase transparency and provide waterproof properties to the tracing paper. EP 1314769 A1 discloses an office tape that can be written on, the office tape comprising cellophane or tracing paper. Cellophane is also known to have low opacity so that labels placed on such cellophane can be automatically detected. For example, cellophane is disclosed in US 2021 / 274831 A1, EP 3059344 A1 and CN 108049249 A. However, the opacity of cellophane is generally not low enough to be suitable for use as a tape base paper, and some mechanical properties of cellophane, such as elongation, are not suitable for the conversion step of forming small rolls of tape. The basis weight of cellophane is also generally too high to be suitable for use as a tape base paper. In order to solve the opacity problem of cellophane, JJP 2017 057515 A and JP2017 133132 A disclose the use of a transparent agent, which requires additional chemicals and additional process steps.

[0004] The solutions proposed in the known prior art to date have several disadvantages. In particular, these solutions are known to provide insufficient mechanical properties and transparency, making the known cellulose fiber-based tapes unsuitable for the intended use or for the conversion steps of small rolls. In addition, the known cellulose fiber-based tapes usually need to be impregnated with adhesives or other additional chemicals in order to provide the required mechanical properties, such as tensile strength and internal bond strength.

[0005] In order to provide a sustainable, highly bio-based and high clarity adhesive tape and overcome at least some of the shortcomings of the prior art, applicants have developed a novel, cellulose fiber-based tape base paper and tape that provides good tensile strength, low basis weight, suitable elongation and excellent clarity while being suitable for recycling in standard paper and paperboard recycling streams.

[0006] In addition, the novel tape base paper and tape have the advantage of being easy to tear regardless of whether a tape dispenser is used. In fact, existing plastic-based office tapes require a dispenser to tear, and sometimes even with a dispenser, existing tapes may be difficult to tear.

[0007] Furthermore, the novel adhesive tape base paper can be repulpable and recyclable, and preferably fully repulpable and recyclable.The adhesive tape can also be repulpable and recyclable, and in particular the release agent can also be repulpable. Summary of the invention

[0008] The invention is defined by the features of the independent claim. Some particular embodiments are defined in the dependent claims.

[0009] The present invention is based on the concept of providing a translucent or transparent paper containing highly refined cellulose fibers as a cellulose fiber-based substrate for the tape. One side of the cellulose fiber-based substrate can be coated with a release agent. In some embodiments, the other side of the cellulose fiber-based substrate can be coated with a primer.

[0010] According to a first aspect of the present invention, there is provided a cellulose fiber-based translucent or transparent tape base paper, which comprises a cellulose fiber-based substrate, the substrate comprising highly refined cellulose fibers having a pulp freeness of 70-90° SR measured using the Schopper-Riegler method, the substrate having a first side and a second side opposite to the first side and a peeling layer located on the first side of the cellulose fiber-based substrate, wherein the opacity index of the cellulose fiber-based substrate is in the range of 13-40%.

[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, comprising the following steps: providing or producing a cellulose fiber-based substrate, the substrate comprising highly refined cellulose fibers having a pulp freeness of 70-90° SR as measured using the Schober-Rieger method; applying a release layer on a first side of the cellulose fiber-based substrate; and optionally applying a primer layer on a second side of the cellulose fiber-based substrate.

[0012] An embodiment of the present invention comprises an adhesive tape, ie an adhesive tape base paper, comprising an adhesive layer of a pressure-sensitive adhesive polymer applied on the second side of a cellulose fiber-based substrate or on an optional primer layer.

[0013] The present invention achieves significant advantages. As mentioned above, in contrast to plastic based tapes, the tapes of the present invention are suitable for recycling in standard paper and cardboard recycling streams according to EN 13430. The product of the present invention has a high biobased content and is compostable both industrially and domestically.

[0014] Secondly, the adhesive tape of the present invention has excellent transparency, which is attributed to the transparency of the adhesive tape base paper, which has an opacity in the same range as the cellulose fiber-based substrate.

[0015] Furthermore, the tape of the present invention does not require the use of a tape dispenser to cut neat segments like plastic-based tapes. The tape has low edge tear resistance, so the tape can be cut without the use of a tape dispenser.

[0016] Furthermore, the adhesive tapes of the present invention have good tensile strength, comparable to common plastic-based adhesive tapes. The adhesive tapes and adhesive tape base papers of the present invention also have high internal bonding and strong barrier properties without the need to impregnate the cellulose fiber-based substrate with adhesives or latex.

[0017] Furthermore, the adhesive base paper has an elongation and breaking load sufficient to prevent tearing and breaking during the converting step when producing small rolls of adhesive tape.

[0018] Further features and advantages of the present technology will appear from the following description of some embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic exploded side view of an adhesive tape roll according to one embodiment of the present invention is shown. A pressure-sensitive adhesive tape roll (1) comprises a cellulose fiber-based substrate (7), a release layer (5), a primer layer (9) and an adhesive layer (11), which is wound on a core shaft (3). DETAILED DESCRIPTION

[0020] The present invention is achieved by Figure 1In a specific embodiment, a translucent or transparent tape base paper based on cellulose fibers is described, and provided, which comprises: a cellulose fiber-based substrate 7, wherein the substrate comprises highly refined cellulose fibers having a pulp freeness of 70-90° SR measured using the Schober-Rieger method, the substrate 7 having a first side and a second side opposite to the first side; and a peeling layer 5 located on the first side of the cellulose fiber-based substrate, wherein the opacity index of the cellulose fiber-based substrate 7 is in the range of 13-40%.

[0021] In this context, translucent or transparent in relation to a material, such as a cellulose fiber-based substrate or tape, means that the material has an opacity index in the range of 13-40% according to the NFQ 03-006 standard. Thus, in some embodiments, the opacity index of the cellulose fiber-based substrate is in the range of 13-40%. In some embodiments, the opacity index may be in the range of 15-20%. In some embodiments, the opacity index may be in the range of 40-20%. In other embodiments, the opacity index may be in the range of 40-30%, and in other embodiments, the opacity index may be in the range of 30-20%.

[0022] In the present disclosure, the adhesive tape base paper includes a cellulose fiber-based substrate and a release layer on a first side of the cellulose fiber-based substrate.

[0023] "Adhesive tape" refers to an adhesive tape base paper comprising an adhesive layer applied to the second side of a cellulose fiber-based substrate or to an optional primer layer disposed on the second side of a cellulose fiber-based substrate prior to receiving the adhesive layer.

[0024] Cellulosic fiber or cellulose fiber refers to a fiber consisting of or derived from cellulose. The cellulose fiber may be selected from the group consisting of kraft pulp fibers, sulfite pulp fibers, chemically treated fibers, mechanically treated pulp fibers, chemithermomechanically treated pulp fibers, regenerated cellulose fibers, and combinations thereof. Typically, the cellulose fibers comprise bleached pulp fibers. Advantageously, the use of cellulose fibers renders the base paper substrate repulpable and / or recyclable, and, depending on the type of release agent and adhesive used, renders the adhesive tape repulpable and / or recyclable. Furthermore, the base paper is bio-based.

[0025] As used herein, highly refined cellulose fibers may refer to cellulose fibers whose pulp freeness may be in the range of 70 to 90°SR, preferably 80 to 90°SR, when measured using a Schober-Rigler (SR) freeness tester. This high level of refining allows the tape paper to have the required transparency for use as an office tape. More specifically, a pulp freeness of 70 to 90°SR allows the tape base paper to have an opacity of 13% to 40%.

[0026] In some embodiments, the amount of refining can also be measured based on the weight % of secondary fines in the highly refined cellulose fibers. In some embodiments, the highly refined cellulose fibers can include greater than 35 wt. % secondary fines based on the total weight of the highly refined cellulose fibers.

[0027] Preferred non-limiting examples of highly refined cellulose fibers include highly refined softwood fibers, highly refined hardwood fibers, regenerated cellulose fibers (e.g., Lyocell fibers), and combinations thereof. Preferred highly refined cellulose fibers are bleached softwood fibers, such as northern bleached softwood kraft (NBSK) fibers and / or southern bleached softwood kraft (SBSK) fibers.

[0028] Advantageously, the proportion of highly refined cellulose fibers in the fibers of the substrate 7 based on cellulose fibers may be 100%. However, in some embodiments, the fibers of the substrate 7 based on cellulose fibers may contain up to 5%, preferably up to 2%, of other fibers than highly refined cellulose fibers having a pulp freeness of 70-90° SR measured using the Schober-Rigler method. The fibers may contain cellulose fibers and / or synthetic fibers, preferably cellulose fibers, having a pulp freeness of less than 70° SR measured using the Schober-Rigler method. In the case of synthetic fibers, the amount needs to be limited, on the one hand to maintain biodegradability, and on the other hand because the tape will be more difficult to tear if the synthetic fiber content exceeds 20%. Preferably, the amount of synthetic fibers may be up to 2%. Most preferably, the substrate 7 based on cellulose fibers consists of highly refined cellulose fibers having a pulp freeness of 70-90° SR measured using the Schober-Rigler (SR) method.

[0029] Synthetic fiber generally refers to the fiber made of fiber forming material, and fiber forming material comprises the polymer synthesized by compound.When present, the preferred non-limiting examples of synthetic fiber can comprise polyamide fiber, polyester fiber, polyvinyl alcohol fiber, polylactic acid fiber, polyhydroxyalkanoate fiber, polyvalerate and polybutyrate fiber and mixture thereof.If synthetic fiber is used, its length is preferably at most 6 mm.The thickness of synthetic fiber can also be 0.5-2.0 dtex.

[0030] In certain embodiments, the highly refined cellulose fiber may comprise softwood fiber, hardwood fiber or a combination thereof. In certain embodiments, the highly refined cellulose fiber may comprise 60-100%, preferably 75-95% softwood fiber and 0-40%, more preferably 5-25% hardwood fiber. In other embodiments, the highly refined cellulose fiber may comprise 80-90% softwood fiber and 10-20% hardwood fiber. In other embodiments, the highly refined cellulose fiber may comprise only softwood fiber and not hardwood fiber. Softwood fiber contributes to improving mechanical properties, particularly due to the high level of refining. In addition, hardwood fiber improves sheet formation and paper smoothness. If broke paper is used in the fiber composition, these broke paper can be highly refined together with fresh fiber.

[0031] In some embodiments, the proportion of highly refined cellulose fibers may include 75-95%, preferably 80-90% softwood fibers. In some embodiments, the proportion of highly refined cellulose fibers may include 5-25%, preferably 10-20% hardwood fibers.

[0032] In some embodiments, the basis weight of the cellulose fiber-based substrate 7 may be 30-60 g / m 2 , preferably about 35-45 g / m 2 The basis weight of the cellulose-fiber-based substrate 7 is an important parameter, since it enables thin tapes. It should also be noted that if the basis weight is too heavy, the opacity of the cellulose-fiber-based substrate 7 will increase.

[0033] In some preferred embodiments, the cellulose fiber-based substrate 7 comprises or is a calendered or super calendered transparent or translucent cellulose fiber-based substrate or paper. Calendering refers to a finishing process of passing the cellulose fiber-based substrate 7 through calender rollers at high temperature and high pressure to smooth the substrate.

[0034] The adhesive tape base paper may include a release layer 5 on the first side of a cellulose fiber-based substrate 7. The release layer 5 may include a release agent in an amount of 0.05 to 5 g / m 2 The amount is preferably 0.05 to 2 g / m 2The amount of release agent is applied to the cellulose fiber-based substrate 7. Since the surface of the cellulose fiber-based substrate 7 comprising highly refined cellulose fibers is smooth and closed, the amount of release agent can be lower but still very effective. Preferably, the peel force of the adhesive tape is comprised between 10 and 500 cN / cm, preferably between 50 and 250 cN / cm, measured according to the STM 3 FINAT test method standard.

[0035] In an embodiment, the release layer 5 may include a release agent selected from the group consisting of silicone, fluorinated silicone, silicone copolymer, fluorocarbon, acrylic acetate, acrylic, styrene acrylic, vinyl acetate, polyvinyl acetate, polyurethane, polyolefin release agent, polyurethane, synthetic resin emulsion and a combination thereof. Preferably, the release agent is selected from the group consisting of silicone, fluorinated silicone, silicone copolymer, acrylic acetate, acrylic and styrene acrylic.

[0036] In some embodiments, the cellulose fiber-based adhesive tape base paper comprises a primer layer 9 located on the second side of the cellulose fiber-based substrate 7. The primer layer 9 comprises a primer, which is generally present in an amount of 0.5 to 3 g / m 2 The amount is preferably 1 to 2 g / m 2 , for example about 1 g / m 2 The amount of the release agent is applied to the cellulose fiber-based substrate 7. In some embodiments, if the release agent is selected from silicone, the coating amount of the release agent is preferably between 0.4 and 0.8 g / m 2 In other embodiments, if the release agent is selected from acrylic acid, the coating amount of the release agent is preferably between 1.0 and 2.0 g / m 2 between.

[0037] If present, the amount of primer depends on the structure of the cellulose fiber-based substrate 7 and the type of optional other agents used. Primers are generally used to ensure good compatibility / affinity between the cellulose fiber-based substrate 7 of the adhesive tape and the adhesive used. However, even without the addition of a primer layer 9, the compatibility / affinity between the cellulose fiber-based substrate 7 or base paper of the present invention may be sufficient.

[0038] When present, the primer layer 9 typically comprises a primer selected from the group consisting of acrylics, styrene acrylics, polyethylene imine, synthetic resin emulsions, polyurethanes, vinyl polymers, modified starches, and mixtures thereof. Preferably, the primer is selected from acrylics or vinyl polymers.

[0039] In certain embodiments, according to ISO 534 standard measurement, the thickness of the adhesive tape base paper is 25-60 μm, preferably between 35 and 50 μm. Especially, this type of thickness is close to the thickness of existing plastic-based office tapes, and can realize small rolls. This type of thickness also makes the visibility of this adhesive tape very low when used. In addition, the low thickness of the adhesive tape base paper also makes this base paper have very low opacity.

[0040] Preferably, according to ISO 1924-2 standard measurement, the longitudinal (MD) dry tensile strength of the adhesive tape base paper is 2-3 kN / m. According to some embodiments, according to ISO 1924-2 standard measurement, the longitudinal dry tensile strength of the adhesive tape base paper is 2-4.5 kN / m, preferably between 3 and 4 kN / m. Such MD tensile strength enables the adhesive tape base paper to be unfolded without breaking or tearing. In addition, such tensile strength prevents problems that may occur in the conversion step, particularly can maintain machine speed in the conversion step, and particularly when applying adhesive layer 11.

[0041] In some embodiments, the tape base paper has a dry elongation of 2-4% in the longitudinal direction and 5-15% in the transverse direction, measured according to ISO 1924-2 standard. The dry elongation prevents problems that may occur in the conversion step, especially when the adhesive layer 11 is applied to the tape base paper 7, and when the tape base paper is unrolled and cut into small rolls to form tapes for packaging or office / stationery tapes.

[0042] In some embodiments, the dry breaking load of the adhesive tape base paper 7 in the longitudinal direction is 45-100 N / 15 mm, and the dry breaking load in the transverse direction is 15-40 N / 15 mm, as measured according to ISO 12625-4 standard.

[0043] In some embodiments, the front Bekksmoothness of the adhesive tape base paper 7 measured according to ISO 5627 standard is 200 to 10000 seconds, and the back Bekksmoothness is 200 to 4000 seconds.

[0044] In some embodiments, the front Baker smoothness of the tape base paper 7 is between 2000 and 9600 seconds, and the back Baker smoothness is between 1000 and 3000 seconds, measured according to ISO 5627. In other embodiments, the front roughness of the tape base paper can be between 500 and 900 seconds, and the back roughness can be between 200 and 500 seconds, measured according to ISO 5627.

[0045] The adhesive tape base paper 7 is produced in the form of a large roll, that is, in the form of a roll with a width of more than 1 meter and a length of several hundred meters. The adhesive tape base paper can be coated with a peeling layer 5, or this can be done at a later stage, but this peeling layer 5 must be present on the adhesive tape base paper 7 before applying the adhesive layer 11. In order to apply the adhesive layer 11, the large roll of the adhesive tape base paper 7 is unrolled, and the adhesive layer is coated on the side of the adhesive tape base paper 7 opposite to the peeling layer 5. The adhesive large roll is then rewound and stored. In order to apply the adhesive layer 11, the large roll is unrolled at a speed of about 100-200 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 above-mentioned mechanical properties.

[0046] In order to convert the adhesive roll into small rolls of tape, a cutting step is performed. To perform this cutting step, the adhesive roll is cut in width and length and wound into small rolls at the end of the cutting step to form a tape for packaging or as an office / stationery tape. This cutting step implements several unwinding steps of the adhesive roll. Usually, the cutting step is carried out at a speed of 150-200 m / min and is stopped after the required length of the final tape is obtained. Therefore, the base paper needs to withstand this tension to prevent tearing and breaking during the conversion / cutting stage.

[0047] In some embodiments, the dry tensile strength of the tape base paper in the cross direction (CD) can be 0.5-1.5 kN / m, measured according to ISO 1924-2. In some embodiments, the dry tensile strength of the tape base paper in the cross direction can be 0.5 to 2 kN / m, measured according to ISO 1924-2.

[0048] Preferably, the edge tear strength of the adhesive tape base paper measured according to TAPPI T 470 om-89 standard is 1-20 N / 15 mm, preferably between 5 and 15 N / 15 mm. Such edge tear strength values ​​make it possible to tear the adhesive tape base paper directly by hand without using a tape dispenser.

[0049] The adhesive tape base paper can have a porosity value. As used herein, porosity refers to the porosity measured according to ISO 5636-3 standard. Therefore, as used herein, porosity refers to Bendsten porosity, which is a measure of the air flow (i.e., air permeability) through the pores of the medium. The porosity of the adhesive base paper and the adhesive tape is measured using a Bendsten porosity tester, which calculates the porosity by forcing air through the paper and measuring the flow rate according to ISO standard 5636-3. In a preferred embodiment, the porosity value of the adhesive tape base paper and the adhesive tape based on cellulose fibers is about 0.3-0.5 ml / min.

[0050] The tape base paper may further comprise an adhesive layer 11 comprising a pressure-sensitive adhesive, preferably in an amount of 5 to 30 g / m 2 , preferably 15 and 20 g / m 2 In some embodiments, about 20 g / m 2 An amount of 100% is applied on the second side of the cellulose fiber-based substrate 7 or on the primer layer 9. An adhesive layer 11 is applied to obtain the final adhesive tape. Figure 1 An example of a finished adhesive tape is shown, comprising an adhesive layer 11 applied on a primer layer 9 , which was placed on the second side of a substrate 7 based on cellulose fibers before receiving the adhesive layer 11 .

[0051] Preferably, the adhesive layer 11 comprises a pressure-sensitive adhesive polymer selected from the group consisting of: hot melt adhesives, such as rubber-based polymers, vinyl acetate and ethylene-vinyl acetate polymers, polyolefins, polyamides, polyesters, polyurethanes, styrene block copolymers, epoxy resins and combinations thereof, preferably natural rubber-based polymers and acrylic-based polymers.

[0052] The adhesive tape base paper of the present invention has a high bio-based material content. Generally, the content of bio-based materials is at least 70%, preferably at least 80%, and more preferably at least 90% of the weight of the adhesive tape base paper.

[0053] A method for producing a cellulose-based adhesive tape base is also described herein. The method may include the following steps: a) providing or producing a cellulose-based substrate 7 comprising highly refined cellulose fibers having a pulp freeness of 70-90° SR as measured using the Schaubel-Rieger method, the substrate 7 having a first side and a second side opposite to the first side; b) applying a release layer 5 on the first side of the cellulose-based substrate 7; and c) optionally applying a primer layer 9 on the second side of the cellulose-based substrate 7.

[0054] In order to produce a cellulose fiber-based substrate 7, a certain amount of cellulose fibers is first provided. The cellulose fibers can be any type disclosed herein, including but not limited to hardwood fibers, softwood fibers, and combinations thereof. If broke paper is used, these broke paper are provided at this stage. Next, the cellulose fibers can be subjected to a refining step to obtain highly refined cellulose fibers. The refining step can include applying energy (i.e., shearing, fibrillation) to the fibers to reduce their length and thickness. After completing the refining step, the highly refined cellulose fibers will have a degree of refinement, which can be measured using a Schober-Rigler (SR) freeness tester. As described above and in the claims, the preferred degree of refinement can be at least 70°, more preferably at least 75°, and most preferably at least 80°. As disclosed above, the amount of refinement can also be measured based on the weight % of secondary fine fibers in the highly refined cellulose fibers. When present, a certain amount of synthetic fibers and / or cellulose fibers having a pulp freeness of less than 70°SR measured using the Schober-Rigler method can be added to the highly refined cellulose fibers after the refining step is completed.

[0055] The cellulose fiber-based substrate 7 can be formed from an aqueous suspension of highly refined cellulose fibers on a conventional paper machine. Advantageously, the cellulose fiber-based substrate 7 is supercalendered off-line or on-line. A release layer 5 can be applied on a first side of the cellulose fiber-based substrate 7. Optionally, a primer layer 9 can be applied on a second side of the cellulose fiber-based substrate 7. If the release layer 5 and / or the primer layer 9 are applied on-line, these layers can be applied before the calendering or supercalendering step, or if these layers are applied off-line, these layers can be applied after the calendering or supercalendering step.

[0056] Preferably, the release layer 5 and the optional primer layer 9 are applied by a technique selected from the following: roll-to-roll coating, blade coating, spray coating, Meyer rod coating, air knife coating, direct gravure printing, offset gravure printing, reverse gravure printing, deep coating, smooth roll coating, curtain coating, bead coating, slot coating, double 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 to the base paper by Meyer rod or curtain coating.

[0057] In one embodiment, the method further comprises the step of applying an adhesive layer 11 on the second side of the cellulose fiber-based substrate 7 or on the primer layer 9, wherein the adhesive layer 11 is applied by a technique selected from the group consisting of roll-to-roll coating, knife coating, spray coating, Meyer rod coating, air knife coating, direct gravure printing, offset gravure printing, reverse gravure printing, deep coating, smooth roll coating, curtain coating, bead coating, slot coating, double HSM coating, film press coating, size press coating and / or transfer film method.

[0058] The production of the cellulose-based bonded base paper can be carried out on a single production line, wherein the cellulose-based substrate 7 is prepared from an aqueous suspension of highly refined cellulose fibers and then coated with a release layer 5. The primer layer 9, if present, can also be applied in-line.

[0059] 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 are extended to their equivalents recognized by those of ordinary skill in the relevant art. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not intended to be limiting.

[0060] References to one embodiment or embodiments throughout this specification mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the invention. Thus, the phrases "in one embodiment" or "in an embodiment" appearing throughout this specification do not necessarily all refer to the same embodiment. When a value is referred to using terms such as about or substantially, the exact value is also disclosed.

[0061] As used herein, for convenience, multiple items, structural elements, constituent elements and / or materials may be presented in a common list. However, these lists should be understood as if each member in the list is individually identified as a separate and unique member. Therefore, unless otherwise stated, any single member in such a list should not be interpreted as a de facto equivalent of any other member in the same list based solely on its presentation in a common group. In addition, various embodiments and examples of the present invention may be mentioned herein together with alternatives to its various components. It should be understood that such embodiments, examples and alternatives should not be interpreted as de facto equivalents to each other, but should be regarded as separate and autonomous representations of the present invention.

[0062] In addition, the described features, structures or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details, such as examples of length, width, shape, etc., are provided to provide a thorough understanding of embodiments of the present invention. However, those skilled in the relevant art will recognize that the present invention may be implemented without one or more of the specific details, or may be implemented using other methods, components, materials, etc. In other cases, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the present invention.

[0063] experiment

[0064] Measurement method

[0065] Pulp Freeness: Schober-Rigler Method and Schober-Rigler (SR) Freeness Tester

[0066] Opacity index: NFQ 03-006 standard

[0067] Peel force: STM 3 FINAT test method standard

[0068] Thickness: ISO 534 standard

[0069] Tensile strength: ISO 1924-2 standard

[0070] Elongation: ISO 1924-2 standard

[0071] Breaking load: ISO 12625-4 standard

[0072] Edge tear strength: TAPPI T 470 om-89 standard

[0073] Bendtsen porosity: ISO 5636-3 standard, values ​​are expressed in mL / min.

[0074] Gurley porosity: ISO 5636-5 standard, values ​​are expressed in seconds.

[0075] Baker Smoothness: ISO 5627 standard

[0076] Roughness: ISO 8791-1 standard

[0077] Hand tearing strength: ISO 1974 standard

[0078] Gram weight or basis weight: ISO 536 standard

[0079] Tear strength: ISO 1974 standard

[0080] Example 1. Cellulose fiber-based substrate 7

[0081] In some embodiments, the cellulose fiber-based substrate 7 may have the following properties:

[0082]

[0083] The fibers in the above-mentioned cellulose fiber-based substrate 7 are highly refined cellulose fibers with a pulp freeness of 70-90° SR measured using the Schebel-Rieger method. In the example 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, which has a dry weight of 20 g / m 2 The amount of is present on the second surface of the cellulose fiber-based substrate 7, and the adhesive used is a water-based acrylic adhesive, such as Primal® PS83D, PS83B or PS2020 sold by Dow, or Ichemco Tackwhite® A39 or A238. For the above measurements, the cellulose fiber-based substrate does not contain any primer layer.

[0084] The comparative example was made of a biaxially oriented polypropylene (BOPP) film having a thickness of 35 μm, which is used to manufacture a pressure-sensitive tape sold by 3M under the name Scotch® 550. This Scotch® 550 tape comprises a release layer made of an acrylic copolymer and an adhesive layer made of a water-based acrylic pressure-sensitive adhesive such as PS8913 sold and manufactured by Dow.

[0085] Example 2. Peeling performance

[0086] The substrate 3 disclosed above is coated on its first side with 0.3 g / m 2 of silicone release agent and coated on the second side with 20 g / m 2 Two different acrylic adhesives were used to form the tapes. The peeling properties of these tapes were measured and compared with those of Scotch 550® manufactured and sold by 3M and Tesa 7475 tape (reference tape corresponding to siliconized paper). The peeling properties were measured based on a revised version of the Finat test method 3 standard using only a standard Finat test roll (2 kg), and the test was only carried out within 20 minutes, not 20 hours (standard requirement), and without prolonged contact weight. As in the previous examples, the adhesive layer 11 comprises a water-based acrylic adhesive, such as Primal® PS83D, PS83B or PS2020 sold by Dow, or Ichemco Tackwhite® A39 or A238. The peeling properties obtained are summarized in the following table:

[0087]

[0088] Example 3. Translucent or transparent tape based on cellulose fibers 1

[0089] This first translucent or transparent adhesive tape 1 based on cellulose fibers is made of a substrate 7 based on cellulose fibers, a release layer 5 and an adhesive layer 11 .

[0090] The cellulose fiber-based substrate 7 is made of 83 wt% of softwood fibers based on the total fiber weight and 17 wt% of broke based on the total fiber weight. The fibers are mixed with water and then refined at 70° SR. The refined fibers are then placed on a forming table of a paper machine, and the mixture is dehydrated and dried to form a paper web. In the following description, the back side of the cellulose fiber-based substrate 7 corresponds to the side in contact with the forming table, and the front side is the opposite side of the paper web.

[0091] Then, a release layer 5 is applied to the cellulose fiber-based substrate 7. According to this embodiment, the release layer 5 is made of a silicone coating. This silicone coating has a dry weight of 0.6 g / m 2 The amount of silicone is placed on the front side of the cellulose fiber-based substrate 7. Usually, this silicone coating is applied by a Meyer rod. The cellulose fiber-based substrate 7 with the release layer 5 is then calendered and wound into a large roll. The large roll generally has a width of more than 1 m and a length of several hundred meters, the width depending on the width of the forming table of the paper machine.

[0092] The cellulose fiber-based substrate 7 has a grammage of 39 g / m2 measured according to ISO 536 2, the thickness measured according to ISO 534 standard is 39 μm. In addition, the opacity of the cellulose fiber-based substrate is 40% measured according to NFQ 03-006 standard. This opacity of the cellulose fiber-based substrate 7 is obtained by the refining and calendering steps of the fiber. According to ISO 5627 standard, the front Baker smoothness of this cellulose fiber-based substrate is 880 seconds and the back Baker smoothness is 228 seconds. In addition, according to ISO 1974 standard, the longitudinal tear strength of the cellulose fiber-based substrate 7 is 213mN and the transverse tear strength is 259 mN. The longitudinal tear strength must be quite high to prevent tearing problems when the cellulose fiber-based substrate 7 is cut into small rolls in the subsequent conversion step. According to ISO 1924-2 standard, the longitudinal dry tensile strength of the cellulose fiber-based substrate 7 is 4.0 kN / m and the transverse dry tensile strength is 2.0 kN / m. When the substrate 7 based on cellulose fiber is unfolded to apply the adhesive layer 11 and the adhesive large roll is cut into small rolls to form the semi-transparent or transparent tape 1 based on cellulose fiber, the longitudinal dry tensile strength is an important factor to prevent the breakage in the conversion step. It should also be noted that the transverse dry tensile strength needs to be quite low so that the user can cut the semi-transparent or transparent tape based on cellulose fiber by hand. According to the ISO 12625-4 standard measurement, the longitudinal breaking load of the substrate 7 based on cellulose fiber is 60 N / 15 mm, and the transverse breaking load is 30 N / 15 mm. The breaking load, especially the longitudinal breaking load, prevents the tearing and breaking that occur during the conversion step of placing the adhesive layer 11 on the substrate 7 based on cellulose fiber and during the cutting step implemented to provide a small tape roll. Then, according to the ISO 1924-2 standard measurement, the longitudinal dry elongation of the substrate 7 based on cellulose fiber is 2.8%, and the transverse dry elongation is 8.2%. The longitudinal dry elongation helps to absorb the tension changes applied during the cutting step of forming a small roll.

[0093] According to this embodiment, it is not necessary to apply a primer to the back side of the cellulose fiber-based substrate 7 because its Bek smoothness is low enough to anchor the adhesive layer 11. In other words, the back side of the cellulose fiber-based substrate 7 is rough enough to anchor the adhesive layer 11. According to this embodiment, the adhesive layer 11 is a water-based acrylic adhesive coating on the back side of the cellulose fiber-based substrate 7 in an amount of 20 g / m 2 .

[0094] Example 4. Translucent or transparent tape based on cellulose fibers 2

[0095] This second translucent or transparent tape based on cellulose fibers is made of a cellulose fiber-based substrate 7 , a release layer 5 , a primer layer 9 and an adhesive layer 11 .

[0096] The cellulose fiber-based substrate 7 is made of 75 wt% of softwood fibers based on the total fiber weight and 25 wt% of hardwood fibers based on the total fiber weight. The fibers are mixed with water and then refined at 85° SR. The refined fibers are then placed on a forming table of a paper machine, and the mixture is dehydrated and dried to form a paper web. The paper web is then supercalendered to produce the cellulose fiber-based substrate 7. In the following description, the back side of the cellulose fiber-based substrate 7 corresponds to the side in contact with the forming table, and the front side is the opposite side of the paper web.

[0097] Then, a release layer 5 is applied to the cellulose fiber-based substrate 7. According to this embodiment, the release layer 5 is made of a silicone coating. This silicone coating has a dry weight of 0.6 g / m 2 The amount of silicone is placed on the front side of the cellulose fiber-based substrate 7. Typically, this silicone coating is applied by a Meyer rod. The cellulose fiber-based substrate 7 with the release layer 5 is then wound into a large roll.

[0098] The primer layer 9 can be applied on the back side of the cellulose fiber-based substrate 7 in-line or off-line. According to this embodiment, the primer layer 9 is placed on the cellulose fiber-based substrate 7 in-line, and this primer is an acrylic polymer. The application of the primer layer 9 is carried out before the supercalendering step and can be carried out before or after the application of the peeling layer 5. Typically, the primer layer 9 is placed on the back side of the cellulose fiber-based substrate 7 by curtain coating. The primer layer 9 has a dry weight of 1 g / m 2 An amount of is applied on the back side of the cellulose fiber-based substrate 7.

[0099] The cellulose fiber-based substrate 7 has a grammage of 39 g / m2 measured according to ISO 536 2, the thickness measured according to ISO 534 standard is 31 μm. In addition, the opacity of the cellulose fiber-based substrate is 15% measured according to NFQ 03-006 standard. This opacity of this cellulose fiber-based substrate 7 is obtained by refining and super calendering steps of the fiber. According to ISO 5627 standard, the front Baker smoothness of this cellulose fiber-based substrate is 3200 seconds and the back Baker smoothness is 1200 seconds. In addition, according to ISO 1974 standard, the longitudinal tear strength of the cellulose fiber-based substrate 7 is 243 mN and the transverse tear strength is 278 mN. The longitudinal tear strength must be quite high to prevent tearing problems when the cellulose fiber-based substrate 7 is cut into small rolls in the subsequent conversion step. According to ISO 1924-2 standard, the longitudinal dry tensile strength of the cellulose fiber-based substrate is 3.5 kN / m and the transverse dry tensile strength is 1.4 kN / m. When the substrate 7 based on cellulose fiber is unfolded to be cut into small rolls to form a translucent or transparent tape based on cellulose fiber, the longitudinal dry tensile strength is an important factor to prevent rupture in the conversion step. It should also be noted that the transverse dry tensile strength needs to be quite low so that the user can cut the translucent or transparent tape based on cellulose fiber by hand. According to ISO 12625-4 standard measurement, the longitudinal breaking load of the substrate 7 based on cellulose fiber is 52 N / 15 mm, and the transverse breaking load is 21 N / 15 mm. The breaking load, particularly the longitudinal breaking load, prevents the tearing and breaking that occur during the conversion step in which the adhesive layer is placed on the adhesive tape base paper and during the cutting step implemented in order to provide a small tape roll. Due to the higher fiber refining degree, the mechanical properties of this substrate 7 based on cellulose fiber are slightly lower than in the previous example. In addition, the reduction of softwood fiber content can slightly reduce mechanical properties, but the addition of hardwood fiber helps the sheet formation on the paper machine, thereby the roughness of the substrate 7 based on cellulose fiber can be reduced. Then, the cellulose fiber-based substrate 7 has a dry elongation of 2.5% in the longitudinal direction and 14.1% in the transverse direction, measured according to ISO 1924-2. The dry elongation in the longitudinal direction helps to absorb the tension variations applied during the cutting step to form the roll.

[0100] According to this embodiment, a primer layer 9 is applied to the back of the cellulose-based substrate 7, because its Bek smoothness is very high, thus enabling the anchoring of the adhesive layer 11. In fact, the purpose of the primer layer 9 is to chemically interact with the adhesive layer 11, and the purpose of this primer layer 9 is to prevent any anchoring problems of the adhesive layer 11 due to the very smooth surface of the cellulose-based substrate 7. However, the very high smoothness of the paper can reduce its opacity, because there is less light scattering at the surface of the cellulose-based substrate 7. According to this embodiment, the adhesive layer 11 is a coating of a water-based acrylic adhesive on the back of the cellulose-based substrate 7, in an amount of 18 g / m 2 .

[0101] Example 5. Translucent or transparent tape based on cellulose fibers 3

[0102] This third translucent or transparent tape based on cellulose fibers is made of a substrate 7 based on cellulose fibers, a release layer 5 and an adhesive layer 11 .

[0103] The cellulose fiber-based substrate 7 is made of 83 wt% of softwood fibers based on the total fiber weight and 17 wt% of broke based on the total fiber weight. The fibers are mixed with water and then refined at 75° SR. The refined fibers are then placed on a forming table of a paper machine, and the mixture is dehydrated and dried to form a paper web. In the following description, the back side of the cellulose fiber-based substrate 7 corresponds to the side in contact with the forming table, and the front side is the opposite side of this paper web.

[0104] Then, a release layer 5 is applied to the cellulose fiber-based substrate 7. According to this embodiment, the release layer 5 is made of a vinyl acrylic copolymer coating. The vinyl acrylic copolymer coating has a dry weight of 1.7 g / m 2 The amount of vinyl acrylic copolymer is placed on the front side of the cellulose fiber-based substrate 7. Typically, this vinyl acrylic copolymer coating is applied by a Meyer rod. The cellulose fiber-based substrate 7 with the release layer 5 is then calendered and wound into a large roll. The large roll generally has a width of more than 1 m and a length of several hundred meters, the width depending on the width of the forming table of the paper machine.

[0105] The cellulose fiber-based substrate 7 has a grammage of 39 g / m2 measured according to ISO 536 2, the thickness measured according to ISO 534 standard is 39 μm. In addition, the opacity of the cellulose fiber-based substrate is 28% measured according to NFQ 03-006 standard. This opacity of this cellulose fiber-based substrate 7 is obtained by the refining and calendering steps of the fiber. According to ISO 5627 standard, the front Baker smoothness of this cellulose fiber-based substrate is 880 seconds and the back Baker smoothness is 228 seconds. In addition, according to ISO 1974 standard, the longitudinal tear strength of the cellulose fiber-based substrate 7 is 213mN and the transverse tear strength is 259 mN. The longitudinal tear strength must be quite high to prevent tearing problems when the cellulose fiber-based substrate 7 is cut into small rolls in the subsequent conversion step. According to ISO 1924-2 standard, the longitudinal dry tensile strength of the cellulose fiber-based substrate 7 is 4.0 kN / m and the transverse dry tensile strength is 2.0 kN / m. When the substrate 7 based on cellulose fibers is unfolded to be cut into small rolls to form the semi-transparent or transparent tape 1 based on cellulose fibers, the longitudinal dry tensile strength is an important factor to prevent the breakage in the conversion step. It should also be noted that the transverse dry tensile strength needs to be quite low so that the user can cut the semi-transparent or transparent tape 1 based on cellulose fibers by hand. According to the ISO 12625-4 standard, the longitudinal breaking load of the substrate 7 based on cellulose fibers is 60 N / 15 mm, and the transverse breaking load is 30 N / 15 mm. The breaking load, especially the longitudinal breaking load, prevents the tearing and breaking that occur during the conversion step of placing the adhesive layer on the tape base paper and during the cutting step implemented to provide a small tape roll. Then, according to the ISO 1924-2 standard, the longitudinal dry elongation of the substrate 7 based on cellulose fibers is 2.8%, and the transverse dry elongation is 8.2%. The longitudinal dry elongation helps to absorb the tension changes applied during the cutting step of forming a small roll.

[0106] According to this embodiment, it is not necessary to apply a primer on the back side of the cellulose fiber-based substrate 7 because its Bek smoothness is low enough to anchor the adhesive layer 11. In other words, the back side of the cellulose fiber-based substrate 7 is rough enough to anchor the adhesive layer 11. According to this embodiment, the adhesive layer 11 is a water-based acrylic adhesive coating on the back side of the cellulose fiber-based substrate 7 in an amount of 19 g / m 2 .

[0107] Example 6. Translucent or transparent tape based on cellulose fibers 4

[0108] This fourth cellulose fiber-based translucent or transparent tape is made of a cellulose fiber-based substrate 7 , a release layer 5 , a primer layer 9 and an adhesive layer 11 .

[0109] The cellulose fiber-based substrate 7 is made of 80 wt% of softwood fibers based on the total fiber weight and 20 wt% of hardwood fibers based on the total fiber weight. The fibers are mixed with water and then refined at 85° SR. The refined fibers are then placed on a forming table of a paper machine, and the mixture is dehydrated and dried to form a paper web. This paper web is then supercalendered to form the cellulose fiber-based substrate 7. In the following description, the back side of the cellulose fiber-based substrate 7 corresponds to the side in contact with the forming table, and the front side is the opposite side of the paper web.

[0110] Then, a release layer 5 is applied to the cellulose fiber-based substrate 7. According to this embodiment, the release layer 5 is made of a vinyl acrylic copolymer coating. The vinyl acrylic copolymer coating has a dry weight of 1.7 g / m 2 The amount of is placed on the front side of the cellulose fiber-based substrate 7. Typically, this vinyl acrylic copolymer coating is applied by a Meyer rod. The cellulose fiber-based substrate 7 with the peeling layer 5 is then wound into a large roll.

[0111] The primer layer 9 can be applied on the back side of the cellulose fiber-based substrate 7 in-line or off-line. According to this embodiment, the primer layer 9 is placed on the cellulose fiber-based substrate 7 in-line. The application of the primer layer 9 can be carried out before or after the supercalendering step, and can be carried out before or after the application of the peeling layer 5. Typically, the primer layer 9 is placed on the back side of the cellulose fiber-based substrate 7 by curtain coating. The primer layer 9 has a dry weight of 1 g / m 2 An amount of is applied on the back side of the cellulose fiber-based substrate 7.

[0112] The cellulose fiber-based substrate 7 has a grammage of 39 g / m2 measured according to ISO 536 2, the thickness measured according to ISO 534 standard is 31 μm. In addition, the opacity of the cellulose fiber-based substrate is 15% measured according to NFQ 03-006 standard. The opacity of this cellulose fiber-based substrate 7 is obtained by refining and super calendering steps of the fibers. According to ISO 5627 standard, the front Baker smoothness of this cellulose fiber-based substrate is 3200 seconds and the back Baker smoothness is 1200 seconds. In addition, according to ISO 1974 standard, the longitudinal tear strength of the cellulose fiber-based substrate 7 is 243 mN and the transverse tear strength is 278 mN. The longitudinal tear strength must be quite high to prevent tearing problems when the cellulose fiber-based substrate 7 is cut into small rolls in the subsequent conversion step. According to ISO 1924-2 standard, the longitudinal dry tensile strength of the cellulose fiber-based substrate is 3.5 kN / m and the transverse dry tensile strength is 1.4 kN / m. When the substrate 7 based on cellulose fiber is unfolded to be cut into small rolls to form a translucent or transparent tape based on cellulose fiber, the longitudinal dry tensile strength is an important factor to prevent rupture in the conversion step. It should also be noted that the transverse dry tensile strength needs to be quite low so that the user can cut the translucent or transparent tape based on cellulose fiber by hand. According to ISO 12625-4 standard measurement, the longitudinal breaking load of the substrate 7 based on cellulose fiber is 52 N / 15 mm, and the transverse breaking load is 21 N / 15 mm. The breaking load, particularly the longitudinal breaking load, prevents the tearing and breaking that occur during the conversion step in which the adhesive layer is placed on the adhesive tape base paper and during the cutting step implemented in order to provide a small tape roll. Due to the higher fiber refining degree, the mechanical properties of this substrate 7 based on cellulose fiber are slightly lower than in the previous example. In addition, the reduction of softwood fiber content can slightly reduce mechanical properties, but the addition of hardwood fiber helps the sheet formation on the paper machine, thereby the roughness of the substrate 7 based on cellulose fiber can be reduced. Then, the cellulose fiber-based substrate 7 has a dry elongation of 2.5% in the longitudinal direction and 14.1% in the transverse direction, measured according to ISO 1924-2. The dry elongation in the longitudinal direction helps to absorb the tension variations applied during the cutting step to form the roll.

[0113] According to this embodiment, a primer layer 9 is applied to the back of the cellulose-based substrate 7, because its Bek smoothness is very high, thus enabling the anchoring of the adhesive layer 11. In fact, the purpose of the primer layer 9 is to chemically interact with the adhesive layer 11, and the purpose of this primer layer 9 is to prevent any anchoring problems of the adhesive layer 11 due to the very smooth surface of the cellulose-based substrate 7. However, the very high smoothness of the paper can reduce its opacity, because there is less light scattering at the surface of the cellulose-based substrate 7. According to this embodiment, the adhesive layer 11 is a coating of a water-based acrylic adhesive on the back of the cellulose-based substrate 7, in an amount of 20 g / m 2 .

[0114] Example

[0115] Embodiments of the present invention include, among others, the following:

[0116] 1. A translucent or transparent tape base paper based on cellulose fibers, comprising:

[0117] - a cellulose fiber-based substrate (7) comprising highly refined cellulose fibers having a pulp freeness of 70-90° SR measured using the Schebel-Rieger method, the substrate (7) having a first side and a second side opposite the first side; and

[0118] - a release layer (5) located on the first side of the cellulose fiber-based substrate (7);

[0119] According to the NFQ 03-006 standard, the opacity index of the cellulose fiber-based substrate (7) is in the range of 13-40%.

[0120] 2. The adhesive tape base paper according to embodiment 1, comprising a primer layer (9) located on the second side of the cellulose fiber-based substrate (7).

[0121] 3. The adhesive tape base paper according to embodiment 2, wherein the primer layer (9) comprises a primer in an amount of 0.5 to 3 g / m 2 The amount is preferably 1 to 2 g / m 2 An amount of is applied to the cellulose fiber-based substrate (7).

[0122] 4. The adhesive tape base paper according to any one of embodiments 2 or 3, wherein the primer layer (9) comprises a primer selected from the group consisting of acrylic, styrene acrylic, polyethylene imine, synthetic resin emulsion, polyurethane, vinyl polymer and mixtures thereof.

[0123] 5. The adhesive tape base paper according to any one of the preceding embodiments, wherein the release layer (5) comprises a release agent in an amount of 0.05 to 5 g / m 2 The amount is preferably 0.05 to 2 g / m 2 An amount of is applied to the cellulose fiber-based substrate (7).

[0124] 6. The adhesive tape base paper according to any one of the preceding embodiments, wherein the release layer (5) comprises a release agent selected from the group consisting of silicone, fluorinated silicone, silicone copolymers, fluorocarbons, acrylic acetates, acrylics, styrene acrylics, vinyl acetate, polyvinyl acetate, polyurethane, polyolefin release agents, polyurethanes, synthetic resin emulsions, and combinations thereof.

[0125] 7. The adhesive tape base paper according to any one of the preceding embodiments has at least one of the following features or a combination thereof:

[0126] - a thickness of 25-60 μm, preferably 35-50 μm, measured according to ISO 534 standard;

[0127] - a CD tear strength of 120-140 mN, preferably about 130 mN, measured according to ISO 1974;

[0128] - MD tensile strength 2-3 kN / m measured according to ISO 1924-2 standard.

[0129] 8. The adhesive tape base paper according to any one of the preceding embodiments, wherein the highly refined cellulose fibers contain 75-95%, preferably 80-90%, softwood fibers and 5-25%, preferably 10-20%, hardwood fibers.

[0130] 9. The adhesive tape base paper according to any one of the preceding embodiments, wherein the cellulose fiber-based substrate (7) comprises or is supercalendered transparent or translucent paper.

[0131] 10. The adhesive tape base paper according to any one of the preceding embodiments, wherein the basis weight of the cellulose fiber-based substrate (7) is 30-60 g / m 2 , preferably about 35-45 g / m 2 .

[0132] 11. The adhesive tape base paper according to any one of the preceding embodiments, wherein it further comprises an adhesive layer (11), the adhesive layer comprising a pressure-sensitive adhesive polymer and applied on the second side of the cellulose fiber-based substrate (7) or on the primer layer (9), preferably at a density of 5 to 30 g / m 2 , more preferably about 20 g / m2 amount applied.

[0133] 12. The adhesive tape base paper according to embodiment 11, wherein the adhesive layer (11) comprises a pressure-sensitive adhesive polymer selected from the group consisting of: hot melt adhesives, such as rubber-based polymers, vinyl acetate and ethylene-vinyl acetate polymers, polyolefins, polyamides, polyesters, polyurethanes, styrene block copolymers, epoxy resins and combinations thereof, preferably natural rubber-based polymers and acrylic-based polymers.

[0134] 13. A method for producing a cellulose fiber-based adhesive tape base paper according to any one of embodiments 1 to 10, comprising the following steps:

[0135] - providing or producing a cellulose fiber-based substrate (7) comprising highly refined cellulose fibers having a pulp freeness of 70-90° SR as measured by the Scheuber-Rieger method;

[0136] - applying a release layer (5) on said first side of said cellulose fiber-based substrate (7);

[0137] - optionally applying a primer layer (9) on the second side of the cellulose fiber-based substrate (7);

[0138] wherein the release layer (5) and the optional primer layer (9) are applied by a technique selected from the group consisting of roll-to-roll coating, knife coating, spray coating, Meyer rod coating, air knife coating, direct gravure printing, offset gravure printing, reverse gravure printing, deep coating, smooth roll coating, curtain coating, bead coating, slot coating, double HSM coating, film press coating, size press coating and / or transfer film method.

[0139] 14. The method according to embodiment 13, further comprising the step of applying an adhesive layer (11) on the second side of the cellulose fiber-based substrate (7) or on the primer layer (9), the adhesive layer (11) being applied by a technique selected from the group consisting of roll-to-roll coating, knife coating, spray coating, Meyer rod coating, air knife coating, direct gravure printing, offset gravure printing, reverse gravure printing, deep coating, smooth roll coating, curtain coating, bead coating, slot coating, double HSM coating, film press coating, size press coating and / or transfer film method.

[0140] 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 as an office / stationery tape.

[0141] Although the foregoing examples illustrate the principles of the present invention in one or more specific applications, it is obvious to those skilled in the art that various modifications may be made to the form, use and implementation details without exercising creative ability and without departing from the principles and concepts of the present invention. Therefore, the present invention is not intended to be limited except by the following claims.

[0142] The verbs "to comprise" and "to include" are used in this document as open limitations, which neither exclude nor require the presence of unrecited features. The features recited in the dependent claims may be freely combined with each other unless expressly stated otherwise. Furthermore, it should be understood that the use of "a" or "an" throughout this document, i.e. in the singular, does not exclude a plural.

[0143] Industrial Applicability

[0144] At least some embodiments of the present invention have industrial applications in the adhesive tape industry. The adhesive tape can be used for packaging and as an office / stationery tape.

[0145] Reference List

[0146] Patent Literature

[0147] EP 2841516 B1

[0148] JP 2000086986A

[0149] WO 2019 / 096848 A1

[0150] US 2021 / 274831 A1

[0151] EP 3059344 A1

[0152] CN 108049249 A

[0153] EP 1314769 A1

[0154] JP 2017057515 A

[0155] JP 2017133132 A

[0156] Non-patent literature.

Claims

1. A translucent or transparent tape base paper based on cellulose fibers, comprising: - a cellulose fiber-based substrate (7) comprising highly refined cellulose fibers having a pulp freeness of 70-90° SR measured using the Schebel-Rieger method, the substrate (7) having a first side and a second side opposite the first side; and - a release layer (5) located on the first side of the cellulose fiber-based substrate (7); According to the NFQ 03-006 standard, the opacity index of the cellulose fiber-based substrate (7) is in the range of 13-40%.

2. The adhesive tape base paper according to claim 1, comprising a primer layer (9) on the second side 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 in an amount of 0.5 to 3 g / m 2 The amount is preferably 1 to 2 g / m 2 An amount of is applied to the cellulose fiber-based substrate (7).

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

5. The adhesive tape base paper according to any one of the preceding claims, wherein the release layer (5) contains a release agent in an amount of 0.05 to 5 g / m 2 The amount is preferably 0.05 to 2 g / m 2 An amount of is applied to the cellulose fiber-based substrate (7).

6. The adhesive tape base paper according to any one of the preceding claims, wherein the release layer (5) comprises a release agent selected from the group consisting of silicones, fluorinated silicones, silicone copolymers, fluorocarbons, acrylic acetates, acrylics, styrene acrylics, vinyl acetates, polyvinyl acetates, polyurethanes, polyolefin release agents, polyurethanes, synthetic resin emulsions, and combinations thereof.

7. The adhesive tape base paper according to any one of the preceding claims, having a thickness of 25-60 μm, preferably 35-50 μm, measured according to ISO 534 standard.

8. The adhesive tape base paper according to any one of the preceding claims, having at least one of the following features or a combination thereof: - According to ISO 1924-2 standard, the longitudinal elongation is 2-4% and the transverse elongation is 5-15%; - 45-100 N / 15 mm longitudinal dry breaking load and 15-40 N / 15 mm transverse dry breaking load measured according to ISO 12625-4 standard; - Measured according to ISO 5627 standard, the front Baker smoothness is 200 to 10,000 seconds and the back Baker smoothness is 200 to 4,000 seconds.

9. The adhesive tape base paper according to any one of the preceding claims, wherein the highly refined cellulose fibers contain 75-95%, preferably 80-90%, softwood fibers and 5-25%, preferably 10-20%, hardwood fibers.

10. The adhesive tape base paper according to any of the preceding claims, wherein the substrate (7) based on cellulose fibers comprises or is a supercalendered transparent or translucent paper.

11. The adhesive tape base paper according to any one of the preceding claims, wherein the basis weight of the cellulose fiber-based substrate (7) is 30-60 g / m 2 , preferably about 35-45 g / m 2 .

12. The adhesive tape base paper according to any of the preceding claims, wherein it further comprises an adhesive layer (11) comprising a pressure-sensitive adhesive polymer and applied on the second side of the cellulose fiber-based substrate (7) or on the primer layer (9), preferably at a density of 5 to 30 g / m 2 , more preferably about 20 g / m 2 amount applied.

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: hot melt adhesives, such as rubber-based polymers, vinyl acetate and ethylene-vinyl acetate polymers, polyolefins, polyamides, polyesters, polyurethanes, styrene block copolymers, epoxy resins and combinations thereof, preferably 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, comprising the following steps: - providing or producing a cellulose fiber-based substrate (7) comprising highly refined cellulose fibers having a pulp freeness of 70-90° SR as measured by the Scheuber-Rieger method; - applying a release layer (5) on said first side of said cellulose fiber-based substrate (7); - optionally applying a primer layer (9) on the second side of the cellulose fiber-based substrate (7); wherein the release layer (5) and the optional primer layer (9) are applied by a technique selected from the group consisting of roll-to-roll coating, knife coating, spray coating, Meyer rod coating, air knife coating, direct gravure printing, offset gravure printing, reverse gravure printing, deep coating, smooth roll coating, curtain coating, bead coating, slot coating, double HSM coating, film press coating, size press coating and / or transfer film method.

15. The method according to claim 14, comprising the step of producing the adhesive tape base paper in the form of a roll.

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

17. The method according to claim 16, wherein the tape base paper is in the form of a roll and the method comprises the step of unrolling the tape base paper roll before applying the adhesive layer.

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

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