Release coating with low coefficient of friction

Abstract

The invention relates to a release coating for fitting a release liner, comprising a release agent and 0.01 to 30 wt%, based on the total weight of the release coating, of a three-dimensional object K, and characterized in that the object K comprises in total at least 90 wt% of one or more polysaccharides. The invention also relates to the use of a release coating of this type in a release liner or on the back side of a carrier of an adhesive tape, as well as to a release liner equipped with the release coating and to the use thereof in an adhesive tape.

Description

Technical Field

[0001] The present invention relates to the technical field of release coatings, such as those used as release liners or anti-adhesive coatings on the back of adhesive tapes. The present invention more particularly relates to release coatings having a low coefficient of friction. Background Art

[0002] At the end of the manufacturing process, the tape coated with adhesive on one or both sides is usually wound into a roll in the form of an Archimedean spiral. In order to prevent the pressure-sensitive adhesives from contacting each other in the case of double-sided tapes, or to ensure easier unwinding (unwinding) in the case of single-sided tapes, the adhesive is covered with a liner material (also called release material) before winding the tape. This type of liner material is known to those skilled in the art as a "release liner" or "liner". In addition to the liner of a single-sided or double-sided tape, the liner is also used to cover the label.

[0003] These release liners can also ensure that the adhesive is not contaminated before use. In addition, the release liner can be adjusted via the properties and composition of the release material so that the tape can be unrolled with the desired force (light or heavy). In the case of tapes coated with adhesive on both sides, the release liner also ensures that the correct side of the adhesive is exposed first when unrolling.

[0004] The liner or release liner is not part of the adhesive tape or label, but only helps its manufacture, storage or further processing by die cutting. In addition, in contrast to the carrier of the adhesive tape, the liner is not firmly bonded to the adhesive layer.

[0005] The release liners used in industry are usually paper or film carriers which are equipped with a release (anti-adhesive) coating substance (also called detackifying (debonding) or anti-adhesive substance) to reduce the tendency of adhered products to adhere to these surfaces (release function). As substances of this type (also called release materials), a variety of different substances can be used: waxes, fluorinated or partially fluorinated compounds and in particular silicones, and various copolymers with silicone components. In recent years, silicones have been widely established as release materials in the field of adhesive tape applications due to their good processability, low cost and wide range of performance characteristics.

[0006] A series of adhesive tapes coated on both sides with adhesive is unwound and applied together with the release liner still present in the product and lining the second adhesive. In the case of manual application, the adhesive of the tape is brought into contact with the substrate by wiping the release liner with the hand. In this form of application, which takes place under contact pressure, strong contact occurs between the release liner of the tape and the hand. Due to the release material used, the release liners used predominantly have a dull surface with a high coefficient of friction. In this case, the application of the product is unpleasant or even painful, especially when it is carried out frequently and / or at high speeds.

[0007] It is known that the coefficient of friction of silicone release coatings can be reduced by various methods, however, all of these methods have certain disadvantages.

[0008] Unmodified silicone systems, such as those formed by crosslinking of functionalized siloxanes, have very good release properties, but have a high coefficient of friction. The coefficient of friction is slightly lower when silicone condensation systems are used instead of the silicone addition systems predominantly used in industry. However, condensation systems use almost exclusively toxic tin catalysts.

[0009] The person skilled in the art knows that friction can be reduced by reducing the layer thickness of the release system. However, this at the same time leads to a generally undesirable deterioration of the release properties. Therefore, the thickness of the release coating cannot be reduced arbitrarily, and generally, it must be ensured that the carrier material is covered with the release coating at least over the entire area. For example, in the case of very open-pored paper carriers, this can result in the release layer having to be applied relatively thickly just to achieve full-area coverage.

[0010] The coefficient of friction of the release system can also be reduced by adding oils or substances that swell the structure formed when the release system is crosslinked. However, this leads to an increase in the proportion (fraction) of mobile substances in the release system. These substances can reduce the peel adhesion (adhesion) of the adhesive in contact with the release system by depositing on it.

[0011] EP 0 903 385 B1 describes the reduction of friction in radiation-crosslinked silicone systems by adding spherical silicone particles prepared by controlled hydrolysis of methyltrimethoxysilane. Expensive and inflexible preparation methods prevent the use of porous or hollow additives, which are particularly advantageous in one aspect of that invention.

[0012] US 7,198,854 B describes silicone preparations for treating textile materials with the aim of reducing friction and creating a glossy appearance. This effect is produced by adding a mixture of nylon and silica particles. The use of silica particles leads to an undesirable increase in peel adhesion in the field of adhesive tapes.

[0013] US Pat. No. 5,620,775 A describes articles whose coating contains glass spheres with a diameter of 20 to 180 μm in order to increase reflectivity and friction and to create a hydrophilic surface.

[0014] Although spheres of 20 μm diameter are too large for use in release films and release papers, the creation of a hydrophilic surface would lead to a significant degradation of the release properties of the adhesive.

[0015] EP 2 535 389 A1 relates to a release coating composition, in particular for equipping (providing) a release liner with a layer consisting of a release coating, the composition comprising:

[0016] Stripping agent and

[0017] 0.01% to 30% by weight (based on the total composition) of a powdered additive in the form of a three-dimensional object based on a polymer, the polymer being produced from vinyl structural units. Release coatings exhibit a low coefficient of friction, but added polymer particles are increasingly being linked to the introduction of "microplastics" into the environment. Summary of the invention

[0018] It is an object of the present invention to provide a release layer which combines a low coefficient of friction with a stable low release value.

[0019] Another object of the invention is to provide release layers which, when used in adhesive tapes, exhibit only a very small reduction in peel adhesion or, ideally, no reduction in peel adhesion due to the transfer of certain components of the release coating to the adhesive after contact.

[0020] A further object of the present invention is to configure the release layers such that they are toxicologically harmless and, as far as possible, also meet sustainability requirements, in particular with regard to microplastics.

[0021] Furthermore, the release layer should be easily processable from a process technology point of view.

[0022] A first and general subject of the invention achieving these objects is a release coating for mounting a release liner, comprising:

[0023] Stripping agent and

[0024] 0.01 wt. % to 30 wt. % of three-dimensional object K, based on the total weight of the release coating,

[0025] And it is characterized in that the body K contains at least 90% by weight of one or more polysaccharides in total.

[0026] According to a first advantageous embodiment of the invention, the release coating consists only of a release agent and a three-dimensional object K.

[0027] "Three-dimensional object" is understood to mean a finite geometric shape in three dimensions that can be described by an interface. A geometric shape is called three-dimensional when it is not completely contained in any one plane, and is called finite when there is a sphere that completely contains the shape.

[0028] The best known objects have flat or round or spherical interfaces. Object K may take the form of, for example, a cylinder, cone, sphere, prism, pyramid, tetrahedron, cube and / or five regular polyhedrons. When an object is bounded only by planes, it is called a polyhedron or a finite polyhedron (polyhedron).

[0029] In one embodiment, the object K may have one or more of the following forms:

[0030] Parallelepiped (Spat), with cuboid and hexahedron (cube) as special cases

[0031] Prisms, with cylinders as a generalization and cuboids and hexahedrons as special cases

[0032] Pyramid, with cone as a generalization and tetrahedron as a special case

[0033] An antiprism, with the octahedron as a special case.

[0034] The object K, in particular the object K of the above-mentioned form, for example the form of a cube, preferably has no corners or sharp edges. For this purpose, the corners or edges that actually exist may be or can be rounded. The object K is preferably an ellipsoid (ellipsoid), more preferably a spheroid, and more particularly a sphere.

[0035] Preferably, according to the invention, the object K has a D50 value of the volume particle size distribution determined by laser diffraction as described herein of not more than 15 μm, particularly preferably not more than 13 μm, in particular not more than 12 μm. The D90 value of the volume particle size distribution of the object K determined by laser diffraction as described herein is preferably not more than 30 μm, particularly preferably not more than 27 μm, more particularly not more than 25 μm. "Diameter K of an object" is understood to mean a straight line connecting two points on the surface of an object and passing through the center point of the object.

[0036] Particularly preferred:

[0037] The object K is a rotation ellipsoid (Rotationsellipsoide), and

[0038] Object K has a volume particle size distribution D50 value of not more than 12 μm.

[0039] It is further preferred that the length of the smallest diameter of the object K deviates from the length of the largest diameter by no more than 20%, more preferably by no more than 10%. "Diameter K of an object" is understood to mean a straight line connecting two points on the surface of the object and passing through the center point of the object. As already described, the object K is very particularly preferably a sphere. In an ideal sphere, the lengths of the largest diameter and the smallest diameter are identical. Slight deviations from the ideal spherical shape do not prevent the word "sphere" from being assigned to the object.

[0040] The objects K can in principle be solid bodies, hollow bodies or porous bodies; preferably, they are solid bodies.

[0041] According to the invention, the object K comprises at least 90% by weight of one or more polysaccharides. The object K preferably comprises at least 92% by weight, more preferably at least 95% by weight, more particularly at least 98% by weight of one or more polysaccharides. Very particularly preferably, the object K consists of one or more polysaccharides.

[0042] One or two or more polysaccharides are preferably selected from cellulose and starch. Thus, preferably, the object K comprises a total of at least 90% by weight of one or more polysaccharides selected from cellulose and starch. More preferably, the object K comprises a total of at least 92% by weight, very preferably a total of at least 95% by weight, more particularly a total of at least 98% by weight of one or more polysaccharides selected from cellulose and starch. Particularly preferably, the object K consists of one or more polysaccharides selected from cellulose and starch.

[0043] Cellulose and / or starch-based bodies K are characterized in particular in that they can be efficiently produced in the desired particle size (particle diameter) and in that they have a high resistance (stability) in silicone systems, which are often used as a basis for release coatings. For example, they have proven to be very resistant to the temperatures of up to 170° C., which are usually common in the crosslinking of silicone systems.

[0044] The object K comprising or consisting of starch is preferably based on starch from potato, corn or rice.

[0045] The object K comprising or consisting of cellulose preferably comprises so-called microcrystalline cellulose.

[0046] In a preferred embodiment of the present invention, the objects K are cellulose or starch spheres having a volume particle size distribution D50 value of not more than 12 μm.

[0047] A non-negligible disadvantage of various conventional plastic-based release layer additives is that when the release liner is coated, the particles partially separate (detach) from the release layer component, unless they are fixed in the release layer, for example, by crosslinking. "Microplastics" can be released in this way. Although the three-dimensional object K according to the invention can indeed also be separated from the release layer component, in this case the particles are toxicologically harmless and biodegradable and are therefore superior to conventional additives, especially from the perspective of sustainability.

[0048] Preferably, the object K is incorporated into the release coating composition using a device selected from a wing stirrer, a dispersion disk and an inline disperser; particularly preferably, the object K is incorporated into the release coating composition by a dispersion disk or an inline disperser. The use of these two devices is particularly effective in eliminating undesirable aggregation of the object K.

[0049] As release agents, it is possible in principle to use all systems known to the person skilled in the art. The release agent is preferably selected from silicones, fluorinated silicones, silicone copolymers, waxes, urethanes and mixtures of two or more of these materials.

[0050] Strippers may include solvent-based and / or solvent-free systems, with solvent-free systems being preferred.

[0051] The release agent may be radiation cross-linkable (UV or electron beam), condensation cross-linkable or addition cross-linkable; preferably, it is addition cross-linkable.

[0052] The release agent is particularly preferably a crosslinked silicone. In the not yet crosslinked state, it therefore preferably comprises a mixture of one or more crosslinking catalysts and one or more so-called heat-curable, condensation-crosslinking or addition-crosslinking polysiloxanes. For condensation-crosslinking silicone systems, the crosslinking catalyst present in the composition is usually a tin compound, for example dibutyltin diacetate.

[0053] Silicone release agents based on addition crosslinking can be cured by hydrosilylation. These release agents usually include the following ingredients:

[0054] Alkenylated polydiorganosiloxanes, more particularly linear polymers having terminal alkenyl groups,

[0055] a polyorganohydrogensiloxane crosslinker, and

[0056] Hydrosilylation catalysts.

[0057] Catalysts which have been established for addition-crosslinking silicone systems (hydrosilylation catalysts) are, in particular, platinum or platinum compounds, for example Karstedt's catalysts (Pt(0) complexes).

[0058] Other silicone systems used may also be light-activated catalysts, known as photoinitiators, in combination with UV-curable cationically crosslinked silicones and / or UV-curable free-radically crosslinked silicones (e.g. acrylate-modified silicones) based on epoxides and / or vinyl ethers. It is also possible to use electron beam-curable silicone acrylates. Depending on their intended use, the silicone systems may also contain further additives, such as stabilizers or flow control aids.

[0059] Photopolymerizable organopolysiloxane substances (compositions) can also be used. For example, substances (compositions) crosslinked by reaction between organopolysiloxanes having hydrocarbon groups directly bonded to silicon atoms and substituted by (meth)acrylate groups in the presence of photosensitizers can be mentioned (see EP 0 168 713 B1 or DE 38 20 294 C1). Also usable are substances (compositions) in which a crosslinking reaction occurs between organopolysiloxanes having hydrocarbon groups bonded to silicon and substituted by mercapto groups and organopolysiloxanes having vinyl groups directly bonded to silicon atoms in the presence of photosensitizers. For example, such substances (compositions) are described in US 4,725,630 A1.

[0060] When using organopolysiloxane materials (compositions) having silicon-bonded, epoxy-substituted hydrocarbon groups, such as those described in DE 33 16 166 C1, the crosslinking reaction is induced by the release of catalytic amounts of acid obtained by photolysis of the onium salt catalyst. Other organopolysiloxane materials (compositions) that can be cured by a cationic mechanism are materials having, for example, acryloxysiloxane end groups.

[0061] According to a particularly advantageous embodiment of the invention, the release coating has the following completely homogenized composition:

[0062] 92.5 to 99.5% by weight of an addition-crosslinking silicone system based on vinyl-functional polysiloxanes, methylhydrogensiloxanes and a platinum catalyst; and

[0063] 0.5 to 7.5% by weight of spheroids, in particular spheres, consisting of cellulose and / or starch, in which the length of the largest diameter deviates from the length of the smallest diameter by no more than 10%.

[0064] Another subject of the present invention is the use of a release coating according to the invention as at least one outer layer of a release liner or as a back coating of an adhesive tape carrier. "Outer layer" and "back coating" here mean that one side of the layer in question is exposed; in particular, this side is oriented outwards, i.e. away from the rest of the release liner or adhesive tape, and is provided for direct contact with the (pressure-sensitive) adhesive. For this purpose, the release coating according to the invention can be applied to a carrier material, preferably as a continuous layer. In the context of the use according to the invention, the release liner is preferably equipped with a release coating according to the invention on both sides.

[0065] If the release coating is based on silicone, the release liner can be produced or the adhesive tape provided with release on the back side can be provided by applying the silicone system on which the release coating according to the invention is based in a solvent-free manner or from a solution to a carrier, wherein in principle all coating techniques familiar to the person skilled in the art can be used. If necessary, the silicone system can then be dried.

[0066] In the context of the use according to the invention, the release coating according to the invention preferably has a layer thickness of 0.1 to 5.0 μm, more preferably 0.2 to 2.5 μm, in particular 0.4 to 2.0 μm.

[0067] In particular, as carrier material for the release liner, paper or film can be used. In this case, the film is preferably made of biaxially stretched polyethylene terephthalate, polybutene, polypropylene, polyethylene, uniaxially stretched polypropylene, biaxially stretched polypropylene or polyethylene, particularly preferably polyolefin films, more particularly polypropylene or polyethylene films, or polyester films.

[0068] In accordance with the above, a further subject of the invention is a release liner comprising a carrier film and a release coating according to the invention.

[0069] Another subject of the invention is an adhesive tape assembled in single-sided adhesive form, comprising a carrier material having a first side and a second side (side) and a pressure-sensitive adhesive on the first side of the carrier material and a release coating according to the invention on the second side of the carrier material.

[0070] The invention also relates to the use of a release coating according to the invention, preferably a silicone-based release coating, as at least one outer layer of a release liner with which a single-sided or double-sided adhesive tape is covered on one or both sides. Typically, single-sided adhesive tapes are lined with a release liner on the adhesive side. In the case of double-sided adhesive tapes, one release liner may be sufficient, but it is also possible for both adhesive sides to be each equipped with a release liner.

[0071] The adhesive present in the adhesive tape is usually and preferably according to the invention a pressure-sensitive adhesive. A pressure-sensitive adhesive is an adhesive that allows permanent bonding to an adhesive substrate under only relatively weak applied pressure. At room temperature, pressure-sensitive adhesives are permanently pressure-sensitive adhesives, i.e., they have sufficiently low viscosity and high contact tack, so that they wet the surface of the corresponding adhesive substrate even under low applied pressure. The bondability of pressure-sensitive adhesives is based on their adhesive properties, and the more or less strongly pronounced re-peelability is based on their cohesive properties. As the basis for pressure-sensitive adhesives, various compounds are considered.

[0072] The polymer base of the pressure-sensitive adhesive is preferably selected from poly(meth)acrylates; silicones; natural rubbers; and synthetic rubbers, especially styrene block copolymers, which have elastomeric blocks composed of unsaturated or hydrogenated polydiene blocks (e.g. polybutadiene, polyisoprene, copolymers of the two), and other elastomeric blocks familiar to those skilled in the art. The pressure-sensitive adhesive may comprise a combination of two or more base polymers and, in addition to one or more base polymers, may also comprise, for example, tackifier resins, plasticizers, fillers, pigments, UV absorbers, light stabilizers, aging inhibitors and / or crosslinking agents, and optionally further additives.

[0073] The carrier or, in the case of so-called adhesive transfer tapes, the liner of the tape can be coated on one side with a pressure-sensitive adhesive from solution, dispersion, 100% form (e.g. from the melt) or by coextrusion. Alternatively, the coating can be carried out by transferring the pressure-sensitive adhesive layer by means of lamination. The adhesive layer can be crosslinked by heat or high-energy radiation.

[0074] The coating weight of the pressure-sensitive adhesive layer is preferably 10 to 120 g / m 2 , more preferably 25 to 100 g / m 2 , which refers to the weight after any necessary removal of water or solvent. The person skilled in the art knows that the numerical value for the coating weight also corresponds approximately to the layer thickness in μm.

[0075] For the purpose of improving adhesion, a physical pretreatment of the support side to be coated with the pressure-sensitive adhesive may be advantageous, for example by flame, plasma or corona treatment. Alternatively or alternatively, a primer layer may be applied before the pressure-sensitive adhesive layer is applied to the support, more particularly in a solvent-free manner, for example by coextrusion, so that a primer layer is located between the support layer and the pressure-sensitive adhesive layer.

[0076] Primers which can be used are the known dispersions and solvent systems, for example based on isoprene- or butadiene-containing rubbers and / or cyclic rubbers. Isocyanates or epoxy resins as additives improve the adhesion and in some cases also increase the shear strength of the pressure-sensitive adhesive.

[0077] A further subject matter of the present invention is the use of a release liner according to the invention in an adhesive tape for joining paper or film webs.

[0078] Flat, web-form material, in particular paper, is often wound into bales in industry, which are then fed, for example, to paper processing machines or printing presses and / or packaging machines. In the ongoing operation of such equipment, the start section of a newly wound bale must be attached to the end of a first bale of flat, web-form material during a high-speed roll change and joined in a suitable manner, without having to stop the machine, which is running at high speed, during the roll change. This process is known as splicing.

[0079] For this purpose, in the paper industry, double-sided adhesive tapes are used, which essentially consist of a carrier layer and two pressure-sensitive adhesive layers, in order to produce a joint between the end of the old material web and the beginning of the new material web. The end of the old material web is in this case glued to the beginning of the new material web.

[0080] For the purposes of the present invention, the generic expression "tape" covers all sheet-like structures, like two-dimensionally extending webs or web portions, tapes with extended length and limited width, tape portions, labels, die-cuts and the like.

[0081] The release coating according to the invention can provide a release liner or a tape back of a release assembly with a significantly lower coefficient of friction compared to the same system without the presence of the object K according to the invention. These additives effectively reduce the friction of the release coating while maintaining good release properties towards a variety of adhesives.

[0082] Furthermore, it has been shown that in the case of solvent-based silicone release systems on film carriers, the object K present in the release coating according to the invention also reduces the reduction in the peel adhesion of the pressure-sensitive adhesive covered with the release system. At least in the fraction range of 1 to 8% by weight of the object K, as the fraction increases, a significant reduction in the reduction in peel adhesion is observed. Therefore, another subject of the present invention is a release liner, which comprises a carrier film and a solvent-based release coating, wherein the release coating contains a release agent and 1 to 8% by weight, more preferably 2 to 6% by weight of a three-dimensional object K, in each case based on the total weight of the release coating, and the body K contains at least 90% by weight of one or more polysaccharides. All design forms of the release coating according to the invention or the release liner according to the invention described herein, as long as they can be used for the release liner described in this paragraph, are also preferred for the release liner. In particular, the material of the carrier film of the release liner described here is selected from biaxially stretched polyethylene terephthalate; polybutylene, polypropylene, especially uniaxially stretched polypropylene and biaxially stretched polypropylene; and polyethylene. Very particularly preferably, the material of the carrier film is uniaxially stretched polypropylene (MOPP).

[0083] "Solvent-based release coating" or "solvent-based silicone release system" means that the release system in question is applied as an actual solvent-containing system, although after crosslinking, which is usually thermally initiated, only at most trace amounts of solvent are present in the release system. However, those skilled in the art refer to this as a "solvent-based system" or "solvent-containing system", thereby characterizing in this way the specific properties of release coatings obtained on the basis of solvents. DETAILED DESCRIPTION

[0084] Example

[0085] Unless otherwise indicated, all fractions of components hereinafter are given in each case based on their weight.

[0086] Manufacture and application of release systems

[0087] Release liners were produced on KSC 950 white paper (UPM) with a width of 1300 mm by applying the release system formulations shown below with and without additives by means of a laboratory coating apparatus. The additives were stirred into the composition by using a wing stirrer. After coating, the release system was crosslinked in a forced air oven at 160° C. for 30 seconds.

[0088] The coefficient of friction of the pads prepared in this way was studied relative to the test tape. and The peel value and peel adhesion are reduced. Test tape is a 40 μm thick PVC carrier coated with 95 g / m 2 Resin modified acrylic pressure sensitive adhesive. Test tape The adhesive is 300 μm thick and uses a natural rubber pressure sensitive adhesive on a textile carrier.

[0089] Measurement of peeling properties

[0090] Place the test tape and 100 mm wide and 300 mm long) were attached to the release liner. For each sample, 3 strips of The pad and the test tape The laminate composed of the liner is stored under pressure and temperature for 24 hours. , the temperature during storage is 40℃, for the test tape , the temperature during storage was 70°C. The pressure in both cases was 4 N / cm².

[0091] After subsequent storage of the samples for 2 hours in a controlled climate measuring chamber at 23° C. and 50% relative air humidity, the peel force was determined by a Zwick tensile tester. The peel speed was 300 mm / min, the peel angle was 180°. The results reported in each case are the average of the measurements from three laminates.

[0092] Measurement of peel adhesion reduction

[0093] In addition, the test tape was measured The possible transfer of silicone or various additives was evaluated by the reduction in peel adhesion. For this purpose, the new test tapes were measured by tensile testing (Zwick tensile testing machine, 300 mm / min, 180°). Peel Adhesion on Steel Surfaces.

[0094] Subsequently, the test tape, which had previously been stored with the liner under pressure and temperature for 24 hours for the purpose of measuring the peel properties, was The same was applied to steel and the peel adhesion was measured using a tensile test. The peel adhesion reduction was calculated according to the following formula:

[0095]

[0096] Measurement of silicone coating

[0097] The coating weight of the release system is determined by X-ray fluorescence analysis. For this purpose, the support to be investigated, which is coated with the release system, is analyzed using a LAB-X3000 X-ray fluorescence analyzer from Oxford with an internal (polydimethylsiloxane) reference. After excitation by X-ray radiation, the energy released is detected in the form of Si-specific fluorescence radiation and is converted stoichiometrically by the instrument into g / m 2 Any false detections caused by additives to the carrier material were taken into account by determining a blank value.

[0098] Determination of application characteristics

[0099] In order to answer the question whether the release system exhibits a pleasant sensation on the skin during application, the samples coated with the release system were evaluated by five test subjects in a direct comparison. The basis for the evaluation was the skin sensation when the liner coated with the release system was applied by hand under relatively strong pressure, i.e. the conventional method known to those skilled in the art for applying pressure-sensitive adhesives. A distinction was made only according to:

[0100] 1 = Pleasant

[0101] 2 = Unpleasant

[0102] Silicone system

[0103] Silicone system A is an addition-crosslinking silicone system from Wacker. 9.75 g of DEH 915 (polydimethylsiloxane functionalized with vinyl groups) are mixed with 0.33 g of V24 (methylhydrogenpolysiloxane) and 0.08 g of Kat 01 (platinum catalyst, also called “Karstedt catalyst”).

[0104] In each case, 2.5 wt. % of PMMA spheres ( , SEPPIC, solid spheres with sizes ranging from 1 to 5 μm) or starch spheres ( , SEPPIC, solid spheres, particle size distribution D50 value 11 μm), the system for the inner side of the liner had no further additions. The mixture was homogenized, applied to a support and then crosslinked as described above.

[0105] Determination of particle size distribution

[0106] The particle size distribution was carried out by laser diffraction using a "Bettersizer S3 Plus" instrument. The dispersion medium used was completely softened water (VE water). The sample was added directly to the dispersion unit filled with VE water. Before the measurement, the sample was exposed to the internal ultrasound of the instrument (35 W), which was also effective during the measurement. The stirring speed was 1200 rpm. The refractive index RI 1.50-0.01 i determined with the instrument was evaluated according to the Mie method.

[0107] Table 1: Application of silicone system, results

[0108]

[0109] Table 2: Results

[0110]

Claims

1. A release coating for mounting a release liner, comprising - Strippers and - 0.01% to 30% by weight of three-dimensional objects K, based on the total weight of the release coating, It is characterized in that The body K comprises in total at least 90% by weight of one or more polysaccharides.

2. The release coating according to claim 1, characterized in that The object K is an ellipsoid.

3. The release coating according to claim 1 or 2, characterized in that The object K has a D50 value of the volume particle size distribution of no greater than 15 μm, as determined by laser diffraction as described herein.

4. Release coating according to any one of the preceding claims, characterized in that The object K is a spheroid, and The object K has a D50 value of volume particle size distribution of not more than 12 μm.

5. Release coating according to any one of the preceding claims, characterized in that The release coating contains a total of 0.1 wt % to 10 wt % of the object K, based on the total weight of the release coating.

6. Release coating according to any one of the preceding claims, characterized in that The object K is a solid object.

7. Release coating according to any one of the preceding claims, characterized in that The body K contains at least 90% by weight of cellulose and / or starch.

8. Release coating according to any one of the preceding claims, characterized in that The release agent is selected from silicones, fluorinated silicones, silicone copolymers, waxes, urethanes and mixtures of two or more of the stated materials.

9. Use of a release coating according to any of the preceding claims as at least one outer layer on a release liner or as a backside coating of an adhesive tape carrier.

10. The use according to claim 9, characterized in that The release coating has a layer thickness of 0.1 μm to 5.0 μm.

11. A release liner comprising a carrier film and a release coating according to any one of claims 1 to 8.

12. Use of the release liner according to claim 11 as a release liner in an adhesive tape for joining paper or film webs.

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