Facestock for direct heat-sensitive linerless label and direct heat-sensitive linerless label

Abstract

The present specification relates to a facestock (100, 200) for a direct heat-sensitive linerless label. The plane material (100, 200) comprises a release layer (101, 201), a thermosensitive layer (102, 202), a precoat layer (103, 203), a base paper (104, 204), and a barrier layer (105, 205). The basis weight of the base paper (104, 204) is 50 g / m2 to 90 g / m2, and the coating weight (dry) of the barrier layer (105, 205) is 0.5 g / m2 to 3.5 g / m2. Further, a direct heat-sensitive linerless label (210), a linerless label product roll and a labelled article including the direct heat-sensitive linerless label are provided. Furthermore, the use of the direct heat-sensitive linerless label (210) to label an article is provided, as well as a method of manufacturing a linerless label web for providing a roll of linerless label product.

Description

Technical Field

[0001] The present specification relates to a face material (face) for a direct thermal linerless label. In addition, the present specification also relates to a direct thermal linerless label, a linerless label product roll including the direct thermal linerless label, and a labeled article. In addition, the present specification also relates to labeling an article using the direct thermal linerless label, and a method of manufacturing a linerless label web (web) for providing a linerless label product roll. Background Art

[0002] Traditional water-based adhesives are particularly challenging for direct thermal linerless facestock materials (paper). Direct application of water-based adhesives results in adhesive wetting, which changes the viscoelastic properties of the facestock, which in turn causes various problems during the production stage and the label application stage by the end user. Changes in viscoelastic properties refer to reduced tensile strength levels and increased elongation in the machine direction (MD) during the adhesive coating and drying / curing process. Problems caused by these changes include, for example, severe label curl after direct thermal printing and cutting of labels, dimensional instability after cutting by the cutter, and web breaks when using lower basis weight facestocks.

[0003] In addition, adhesives are susceptible to migration of adhesive components through the facestock when used with paper-based direct thermal linerless facestock. Migration of adhesive components into the thermal layer of the facestock reduces the sensitivity of the thermal layer. This reduces the direct thermal printing performance of the facestock. Therefore, new facestock materials are needed to alleviate the above challenges. Summary of the invention

[0004] The facestock disclosed herein has improved properties that have a positive impact on the performance of the label face, from the manufacture of the label roll to the dispensing of the label. During the application of the adhesive using a water-based adhesive, wetting of the facestock can be prevented or reduced, thereby providing improved tension control and better dimensional stability. In addition, the facestock disclosed herein can also improve the flatness of the label, that is, reduce the curl of the label, thereby improving the efficiency of the printing process and making the label easier to dispense, especially when using an automatic dispensing machine. Further, this facestock can also improve the stability of the thermal layer, thereby ensuring that the print quality is maintained even after aging.

[0005] According to one embodiment, a surface material for a direct thermal linerless label is provided. The surface material comprises a release layer, a thermal layer, a pre-coating layer, a base paper and a barrier layer. The base paper has a grammage of 50 g / m 2 Up to 90g / m 2 , the coating weight (dry) of the barrier layer is 0.5 g / m 2 Up to 3.5g / m 2 .

[0006] According to another embodiment, a direct thermal linerless label is provided. The direct thermal linerless label comprises a pressure-sensitive adhesive and a surface material, wherein the surface material comprises a release layer, a thermal layer, a pre-coating layer, a base paper and a barrier layer, and the base paper has a grammage of 50 g / m 2 Up to 90g / m 2 The release layer and the pressure-sensitive adhesive are arranged on opposite sides of the base paper.

[0007] In one embodiment, a roll of linerless label products is provided that includes the direct thermal linerless labels disclosed herein.

[0008] In addition, in one embodiment, a labeled article is provided, which includes an article and the direct thermal linerless label disclosed herein. The direct thermal linerless label is attached to the surface of the article by the pressure-sensitive adhesive of the direct thermal linerless label.

[0009] In one embodiment, there is provided a use of a direct thermal linerless label disclosed herein for labeling an article.

[0010] According to another embodiment, a method for manufacturing a linerless label roll is provided, the linerless label roll being used to provide a linerless label product roll. The method comprises:

[0011] - Arrange the surface material or carrier as a substrate,

[0012] - coating the substrate with a pressure-sensitive adhesive,

[0013] - drying and / or curing of the pressure-sensitive adhesive on the substrate,

[0014] - in the case where the substrate is a carrier, transferring the pressure sensitive adhesive from the carrier to the face stock, and

[0015] - The face stock with adhesive thereon is wound into a roll of linerless label stock.

[0016] The surface material includes a release layer, a heat-sensitive layer, a pre-coating layer, a base paper and a barrier layer. The base paper has a grammage of 50g / m 2 Up to 90g / m 2 , the coating weight (dry) of the barrier layer is 0.5 g / m 2 Up to 3.5g / m 2 . BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 illustrates a cross-sectional view of a direct thermal unlined facestock, and

[0018] Figure 2 Illustrated is a cross-sectional view of a direct thermal linerless label.

[0019] The figures are schematic and not to scale. DETAILED DESCRIPTION

[0020] The solution will be described in more detail below with reference to some embodiments, but these embodiments should not be considered limiting.

[0021] In the present description and claims, unless otherwise stated, percentage values ​​relating to the amount of material are weight percentages (wt%). Thickness is expressed in micrometers, i.e. μm. Temperature is expressed in degrees C, equivalent to °C. The following reference numerals and symbols are used in the specification:

[0022] 100,200 Surface material

[0023] 101,201 Release layer

[0024] 102,202 Thermal layer

[0025] 103,203 Pre-coating

[0026] 104,204 base paper

[0027] 105,205 Barrier layer

[0028] 210 Direct Thermal Linerless Label

[0029] 211 Pressure sensitive adhesive

[0030] A label is a sheet of material applied to an article or item of different shapes and materials. The article or item may be a package. The label comprises at least one face stock material, also referred to as face stock or face stock. A typical method of attaching a label to an article or item is by using an adhesive. Labels comprising an adhesive layer are referred to as adhesive labels. The adhesive may comprise or consist of a pressure sensitive adhesive (PSA). Labels comprising a pressure sensitive adhesive may be referred to as pressure sensitive adhesive labels. Pressure sensitive adhesive labels are also referred to as self-adhesive labels.

[0031] By means of the adhesive layer, labels comprising PSA can be adhered to most surfaces without the use of a second agent (e.g., a solvent) or heating to strengthen the bond. In this case, the adhesive itself is pressure sensitive. Alternatively, the adhesive may be activatable so as to be pressure sensitive. When pressure is applied to the label at ambient temperature (e.g., between 15°C and 35°C), or for cold applications even at freezing temperatures below 0°C, or for hot applications at temperatures above 35°C, the PSA forms a bond so that the label adheres to the item / article to be labeled. Examples of pressure-sensitive adhesives include water-based (water-bearing) PSAs, solvent-based PSAs, and hot melt PSAs. The label may further include other adhesives.

[0032] Labels may include, but are not limited to, paper labels and film labels. Labels may be linerless or may have a release liner. Examples of labels include, but are not limited to, packaging labels and specialty labels. Packaging labels include, but are not limited to, labels used for beverages, food, health and personal care products, pharmaceuticals, industrial chemicals, household chemicals, or retail product packaging. Specialty labels include, but are not limited to, repositionable labels, removable labels, washable labels, resealable labels, invisible labels, deep freeze labels, and anti-counterfeiting labels.

[0033] The label may provide information about the labeled product, such as product specifications. The information, such as the print of the label, may include human-readable information, such as images, logos, text and / or machine-readable information, such as barcodes, QR (quick response) codes. The surface of the labeled article / article may be, for example, plastic, glass, metal, cardboard or paper. The labeled article / article may be, for example, a container, such as a bottle, a jar, a can, a can, a tin, etc. The label may also be applied to a semi-rigid or flexible packaging (e.g., for packaging food).

[0034] The term "face material" refers to the top substrate of the label, also referred to as face paper or face material. The face material can have a single-layer structure or a multilayer structure including at least two layers. The face material is a layer that is adhered to the surface of the product / article by an adhesive layer during the labeling process. The face material includes an adhesive side and a printing side. A combination comprising a face material and an adhesive can be referred to as an adhesive label. The face material can, for example, include a print to provide information and / or a visual effect. The print can be present on the top surface, the back side, or both the top surface and the back side of the face material. In addition, the label can include an additional layer, such as a top coating or an overlaminate, to protect the top surface and / or print of the label from friction or other external stresses. A coating or additional layer, such as a primer, can enhance the compatibility of adjacent layers or parts of the label, such as adhesion between layers. A label comprising a face material, a print layer, and an adhesive can be referred to as a printed label.

[0035] The term "coil" refers to a continuous sheet of material. Coils are typically processed by moving on rollers. Between processing stages, coils can be stored and transported in roll form.

[0036] The term "machine direction" or MD refers to the direction in which the web is manufactured. The machine direction may also refer to the circumferential direction of a roll. The term "cross direction" or "cross machine direction" or CD refers to the direction transverse to the machine direction.

[0037] The facestock of the present disclosure may be suitable for use as a facestock for non-washable direct thermal linerless labels. The term "non-washable" herein refers to an article that is not intended to be removed under washing conditions, i.e., not intended to be washed off the article. In other words, the label for which the facestock is suitable is not a wash-off label, i.e., a label that can be removed from the surface of an article during the washing process.

[0038] Wash-off labels often contain adhesives that are sensitive to washing conditions. In addition, to ensure washability of wash-off labels, the face stock of the label must usually allow water to penetrate and / or migrate to the bottom of the label. Therefore, the face stock of wash-off labels usually has a certain degree of hydrophilicity, which can be expressed as water absorption. For example, the water absorption of the base paper of a wash-off label can be 10g / m 2 Up to 30g / m 2 In addition, the paper-based facestock of wash-off labels may typically include a wet-strength resin. The wet-strength resin serves to resist rupture forces.

[0039] According to one embodiment, the facestock according to the present disclosure is not particularly hydrophilic because water is not expected to penetrate and / or migrate from the top side of the label to the bottom side. The water absorption of the facestock may be less than 10 g / m when measured according to ISO Standard 535 (Cobb method) using a contact time of 60 seconds. 2 , for example, less than 5g / m 2 .

[0040] Direct thermal linerless labels are linerless labels that can be printed by direct thermal printing. Direct thermal printing is done by applying heat to the material to be printed. It does not use any ribbons, inks or toners, but requires that the material to be printed (in this case, the label face stock) has a heat-sensitive material that turns black when exposed to heat. Because the label face stock material is heat-sensitive, the print may fade and the printed labels may become difficult to read and scan over time. Direct thermal labels are sensitive to abrasion and exposure to water, chemicals and strong sunlight. To enable thermal printing, the face stock includes a heat-sensitive layer.

[0041] Example end uses of direct thermal linerless labels according to the present disclosure include, for example, retail applications, industrial food applications, logistics, and fast food restaurants. In logistics and industrial food applications, labels are typically automatically dispensed using a fast automatic dispenser, i.e., affixed to the surface to be labeled. Automatic dispensing places certain requirements on the labels. For example, the labels to be automatically dispensed need to have sufficiently high initial tack and no label curl. Typically, labels used in retail applications and fast food restaurants are manually dispensed.

[0042] The printing of the direct thermal linerless labels disclosed herein is usually carried out separately from the manufacturing process. Therefore, as a result of the manufacturing process, an unprinted label product roll is provided. The label product roll is composed of a label web that usually includes a label width.

[0043] The labels are usually printed by a printer arranged to print linerless labels. Such a printer may be referred to as a linerless printer. In particular, the printer is a direct thermal linerless label printer. The printer may be a so-called on-demand printer. The printer may accept a roll of linerless label product having a width ranging, for example, from 10 mm to 100 mm. Thus, the label width may be in the range of, for example, 10 to 100 mm. As described above, after printing, the labels are applied manually or automatically to the surface to be labeled.

[0044] A linerless label is a label consisting of a face stock and an adhesive on the face stock. The face stock of a linerless label usually includes a release layer. The purpose of the release layer is to enable the label to be self-wound. A linerless label web having a pressure-sensitive adhesive on one side (the bottom side) and a release coating forming a release layer on the other side (the top side) can be self-wound around itself without the tendency of adjacent layers of the label web to block each other.

[0045] Provides a face stock for direct thermal linerless labels. Figure 1 As shown. The surface material 100 includes a release layer 101, a heat-sensitive layer 102, a pre-coating layer 103, a base paper 104 and a barrier layer 105. Preferably, the order of the layers is as described above, the release layer is the uppermost layer, and the barrier layer is the bottom layer. The base paper separates the front and back sides of the surface material. The front side includes a release layer, a heat-sensitive layer and a pre-coating layer. The back side includes a barrier layer, also called a back barrier layer.

[0046] The base paper may contain natural fibers as its raw material. Natural fibers refer to any plant material containing cellulose. Natural fibers may be wood-based. Paper-based facestock is well suited to the growing trend of reducing the use of unnecessary plastic materials.

[0047] The face stock disclosed herein is suitable for use with water-based adhesives. Therefore, the face stock according to the present disclosure exhibits good compatibility with water-based adhesives. This is achieved by protecting the heat-sensitive layer of the base paper and the face stock from adhesive wetting and avoiding the migration of adhesive components into the heat-sensitive layer. This is achieved by providing a barrier layer for the face stock.

[0048] The barrier layer is the receiving surface of the adhesive of the direct thermal linerless label disclosed herein. The barrier layer may include any type of coating that can be used as a physical barrier layer, especially as a physical barrier layer to prevent water migration. Preferably, the barrier layer includes a water-based coating. Exemplary components of such coatings include styrene-butadiene, styrene acrylate, kaolin and polyvinyl alcohol (PVA). In one example, the coating forming the barrier layer is based on kaolin. For example, the barrier layer may include PVA and kaolin. In one example, the barrier layer includes 0.3 to 0.7 g / m 2 PVA and / or 1.0 to 2.0 g / m 2 Kaolin.

[0049] Barrier coating weights (dry) range from 0.5 to 3.5 g / m 2 From the perspective of material usage, the lower the coating weight, the better. In addition, too high a coating weight may affect the stiffness and affect the cuttability of the label.

[0050] Barrier layers have a positive impact on the performance of label facestock, from the manufacture of label rolls to the dispensing of labels. During the manufacturing stage, barrier layers prevent or reduce wetting of the facestock (especially the base paper) by water-based adhesives, thereby improving tension control, reducing tension variations and providing better dimensional stability. Tension control is particularly required during the slitting stage, during which the original label roll is slit, i.e. cut longitudinally, to provide label product rolls (or simply label rolls). In addition, barrier layers can improve the flatness of the labels, i.e. reduce curl. As mentioned above, lower curl can improve printing efficiency and facilitate dispensing in automatic dispensers, for example, by preventing paper jams caused by curled labels. Preventing paper jams can avoid maintenance interruptions, thereby improving process efficiency.

[0051] In addition, the barrier layer prevents or reduces the migration of adhesive components into the thermal layer, thereby improving the stability of the thermal layer. With a more stable thermal layer, the direct thermal printing characteristics of the facestock remain unchanged after aging, ensuring good print quality even after aging. Adhesive components that migrate into the thermal layer may reduce the sensitivity of the thermal layer. Static sensitivity indicates the temperature at which the thermal paper begins to form an image (i.e., change color). The dynamic sensitivity of the thermal paper actually indicates the printing speed that the thermal paper can achieve. The lower the dynamic sensitivity of the thermal layer, the higher the print head temperature required. With a constant print head temperature, the reduced sensitivity may result in reduced print quality. After the print quality is reduced, the machine may not be able to read reliably or at all. Thermal papers with lower dynamic sensitivity require higher print head temperatures and / or longer exposure times, i.e. slower printing speeds, to achieve higher print optical density.

[0052] According to ISO 536 standard, the base paper weight is 50g / m 2 Up to 90g / m 2 In one example, the base paper weight is 70 g / m 2 When measured according to ISO 534, the thickness of the base paper is 45 μm to 90 μm. In one example, the grammage of the base paper is 50 g / m 2 , the thickness is 48μm. In another example, the base paper weight is 70g / m 2 , the thickness is 68μm.

[0053] The base paper may include fibers, fillers, pigments, binders and additives. In one example, the base paper may contain 40 g / m 2 Up to 70g / m 2 The base paper may contain 1g / m 2 Up to 8g / m 2 An example of a filler pigment is calcium carbonate. The base paper may contain 1 g / m 2 Up to 3g / m 2 The base paper may also contain 0.1 g / m 2 Up to 1.0g / m 2 additives.

[0054] The purpose of the release layer is to enable the label material to be self-winding. This means that a linerless label web having a pressure sensitive adhesive on one side (bottom side) and a release coating forming a release layer on the other side (top side) can be self-winding around itself without there being a tendency for adjacent layers of the label web to block each other. The release coating forming the release layer can be silicone based or non-silicone based. The release layer can comprise one or more layers of release coating. The amount of release layer / release coating on the facestock can be 0.5 g / m 2 Up to 1.5g / m 2 , for example 1.0g / m 2 .

[0055] In one example, the release coating is silicone-based. The silicone-based release coating may include a UV-curable silicone, such as a UV free radical silicone or a cationic UV silicone. In order to avoid heating the heat-sensitive components in the heat-sensitive layer, a non-thermosetting release coating (such as UV-curable silicone) may be preferred.

[0056] The function of the thermal layer is to provide direct thermal printability to the face stock. The thermal layer is configured to form a thermally reactive layer that changes color during the thermal printing process. As mentioned above, the sensitivity of the thermal layer refers to the degree to which it responds to a given amount of heat or energy.

[0057] The heat-sensitive layer may include a color former (e.g., a leuco dye), a developer (preferably phenol-free), an absorptive pigment (e.g., calcined clay), a binder (e.g., PVA), and additives (including, for example, defoamers and surfactants). In one example, the amounts of the heat-sensitive layer components may be as follows: 0.3 g / m 2 Up to 0.7g / m 2 Color former, 0.6g / m 2 Up to 1.0g / m 2 Developer, 0.3g / m 2 Up to 0.7g / m 2 Absorbent pigment, 0.3g / m 2 Up to 0.7g / m 2 Adhesive and / or 0.3g / m 2 Up to 0.7g / m 2 additives.

[0058] The pre-coat layer of the face material may include a pigment (such as calcined clay) and a binder (such as starch and / or styrene-butadiene latex). In one example, the pre-coat layer may include 4 g / m 2 Up to 8g / m 2 Pigment and / or 1g / m 2 Up to 3g / m 2 The pre-coat layer may have the effect of reducing the heat transfer from the heat-sensitive coating to the base paper. This may enable the formation of enhanced or high-resolution print content. The pre-coat layer may have the effect of smoothing the surface material. The smoothness of the surface material has a positive impact on printing, for example by providing better resolution. Therefore, the pre-coat layer may have a positive impact on the print quality.

[0059] The direct thermal linerless label disclosed herein comprises the above-mentioned face material and a pressure-sensitive adhesive. Figure 2 The direct thermal linerless label 210 comprises a pressure-sensitive adhesive 211 and a surface material 200 , wherein the surface material 200 comprises a release layer 201 , a thermal layer 202 , a pre-coating layer 203 , a base paper 204 and a barrier layer 205 .

[0060] The pressure sensitive adhesive may be a water-based adhesive. Water-based adhesives offer improved sustainability, involving fewer fossil raw materials and fewer volatiles during manufacturing and end-use. The water-based adhesive may include a water-based acrylic emulsion polymer composition. Alternatively, the pressure sensitive adhesive may be a hot melt adhesive. The coating weight of the pressure sensitive adhesive may be 12 g / m 2 Up to 25g / m 2 , such as 19g / m 2 Up to 22g / m 2 (Dry weight). Pressure sensitive adhesives can be provided as a single layer or multiple layers. Pressure sensitive adhesives can be removable or permanent adhesives.

[0061] As previously mentioned, the reverse barrier layer is the adhesive receiving surface of the face stock. The barrier layer can prevent or reduce the migration of adhesive components from the adhesive layer into the base paper and ultimately into the heat-sensitive layer. Since the migration of adhesive components into the base paper can be prevented or reduced, an adhesive with lower adhesive properties (i.e., tack and peel properties) can be used compared to labels without a barrier layer on the face stock. With the solution disclosed herein, the adhesive has better adhesive properties than labels without a barrier layer on the face stock.

[0062] Tack refers to the holding power (adhesion) of an adhesive when in contact with a substrate. An adhesive with a high initial tack will quickly grab the substrate. An adhesive with a low initial tack will exhibit a low level of adhesion when applied. Tack can be measured according to the loop tack measurement of FINAT Test Method No. 9 (FTM9). The loop tack value of an adhesive is expressed as the force required to separate a loop of material in contact with a surface of a specific area at a specific speed.

[0063] Peel force (also known as peel adhesion) is a measure of the ability of an adhesive to wet a substrate surface and subsequently adhere to the substrate. Peel force can therefore quantify the durability of an adhesive's adhesion or ability to peel. Peel force is defined as the force required to remove an adhesive coating material from a test panel after dwelling for a certain period of time at a 90 or 180 degree angle and a specific speed. Peel adhesion therefore refers to the ultimate adhesion. Peel adhesion can be measured according to FINAT Test Method No. 1 or 2 (FTM 1, FTM2).

[0064] According to one embodiment, the adhesive of the direct thermal linerless label disclosed herein has an average tack on glass / HDPE / paperboard in the range of 1.5 to 15N, such as 6 to 15N, when measured according to FTM 9.

[0065] According to one embodiment, the adhesive of the direct thermal linerless label disclosed herein has an average peel force on PE / paperboard in the range of 1.5 to 10 N, such as 3 to 8 N, when measured according to FTM 1 or FTM 2.

[0066] In general, labels comprising facestock with a barrier layer achieved higher or comparable adhesion values ​​when compared to labels comprising facestock without a barrier layer. Adhesion on at least glass and HDPE was significantly higher for labels comprising facestock with a barrier layer.

[0067] The direct thermal linerless labels disclosed herein are provided as part of a linerless label product roll that includes direct thermal linerless labels.

[0068] A method for manufacturing a linerless label roll for providing a linerless label product roll, comprising providing a surface material or a carrier as a substrate, coating the substrate with a pressure-sensitive adhesive, drying and / or curing the pressure-sensitive adhesive on the substrate, transferring the pressure-sensitive adhesive from the carrier to the surface material when the substrate is a carrier, and winding the surface material with the adhesive thereon into a linerless label roll. The surface material comprises a release layer, a heat-sensitive layer, a pre-coating layer, a base paper, and a back barrier layer. The base paper has a grammage of 50 g / m 2 Up to 90g / m 2 .

[0069] The width of the linerless label roll is usually a multiple of the width of the linerless label product roll (ie, customer roll). The linerless label product roll is manufactured by machine direction slitting the linerless label roll.

[0070] When the manufacturing process uses direct coating, the wetting of the face stock by water-based adhesives is most serious. In direct coating, the water-based adhesive is directly applied to the face stock and then the adhesive is dried / cured on the face stock. The face stock containing the reverse barrier layer according to the present disclosure prevents or reduces the wetting caused by the water-based adhesive.

[0071] Alternative manufacturing methods utilizing indirect application of adhesives may not be as easily wetted by the adhesive as direct methods. In such methods, the adhesive is applied to a separate carrier and dried / cured on the carrier. Subsequently, the dried / cured adhesive is transferred from the carrier to the face stock. Thus, when the face stock comes into contact with the adhesive, most of the water originally contained in the adhesive is no longer present. However, label webs produced by indirect adhesive application methods may still have a tendency for adhesive components to migrate from the adhesive to the face stock. The face stock comprising a reverse barrier layer according to the present disclosure also prevents or reduces migration of adhesive components.

[0072] Example

[0073] An exemplary direct thermal linerless label (label 1) has a facestock with the following structure:

[0074] 1) a release layer having a silicone-based release coating,

[0075] 2) A heat-sensitive layer comprising

[0076] - leuco dyes as couplers,

[0077] - Phenol-free developer,

[0078] - absorbent pigments,

[0079] - binder,

[0080] -additive,

[0081] 3) a pre-coat layer comprising calcined clay as a pigment and a binder,

[0082] 4) Base paper, comprising

[0083] -About 50g / m 2 fiber,

[0084] - Filling with pigment,

[0085] - binder,

[0086] -additive,

[0087] 5) Barrier layer comprising PVA and kaolin. The coating weight (dry) of the barrier layer was 2 g / m 2 .

[0088] The direct thermal linerless label (label 2) used for comparison has the same facestock structure, but lacks the barrier layer. The base paper weight of both labels is 70g / m 2 .

[0089] Both labels comprised a pressure sensitive adhesive comprising a water-based acrylic emulsion polymer composition disposed adjacent to the barrier layer of the facestock. The PSA coating weight (dry) for both labels was 19 to 22 g / m 2 A coating speed of 100 m / min was used in the adhesive coating stage.

[0090] The adhesive properties of Labels 1 and 2 were determined and are shown in Table 1 below.

[0091] Table 1.

[0092] Tag 1 Tag 2 Adhesion on glass (N) 12.9 8.3 Adhesion on HDPE(N) 10.0 7.86 CB stickiness (N) 7.3 7.3 Peel force on PE (N) 5.5 4.7 CB peeling force (N) 6.1 5.1

[0093] Table 1 shows that label 1 with a barrier layer exhibits higher adhesion on glass and HDPE compared to label 2 which does not contain a barrier layer. Adhesion values ​​on cardboard (CB) are comparable. Likewise, the peel force on PE and cardboard is higher for label 1 compared to label 2.

Claims

1. A face material (100, 200) for a direct thermal linerless label, wherein the face material (100, 200) comprises: - a release layer (101, 201), - a heat-sensitive layer (102, 202), - pre-coating layer (103, 203), - base paper (104, 204); and - a barrier layer (105, 205), Among them, the weight of the base paper (104, 204) is 50g / m 2 Up to 90g / m 2 The coating weight (dry) of the barrier layer (105, 205) is 0.5 g / m 2 Up to 3.5g / m 2 .

2. The surface material (100, 200) according to claim 1, wherein: The barrier layer (105, 205) comprises PVA and kaolin.

3. A direct thermal linerless label (210) comprising a pressure sensitive adhesive (211) and the face material (100, 200) according to claim 1 or 2, wherein the release layer (101, 201) and the pressure sensitive adhesive (211) are arranged on opposite sides of a base paper (104, 204).

4. The direct thermal linerless label (210) of claim 3, wherein: The pressure sensitive adhesive (211) is a water-based adhesive.

5. The direct thermal linerless label (210) of claim 3, wherein: The pressure sensitive adhesive (211) is a hot melt adhesive.

6. The direct thermal linerless label (210) according to any one of claims 3 to 5, wherein: The coating weight of the pressure sensitive adhesive (211) is 12 g / m 2 Up to 25g / m 2 .

7. A linerless label product roll comprising the direct thermal linerless label (210) according to any one of claims 3 to 6.

8. A labeled article comprising an article and the direct thermal linerless label (210) according to any one of claims 3 to 6, wherein the direct thermal linerless label (210) is adhered to a surface of the article by a pressure-sensitive adhesive (211) of the direct thermal linerless label.

9. Use of the direct thermal linerless label (210) according to any one of claims 3 to 6 for labeling articles.

10. A method of manufacturing a linerless label roll for providing a linerless label product roll as claimed in claim 5, the method comprising: - arranging the surface material (100, 200) or the carrier as a substrate, - coating the substrate with a pressure-sensitive adhesive (211), - drying and / or curing the pressure-sensitive adhesive (211) on the substrate, - in the case where the substrate is a carrier, transferring the pressure sensitive adhesive (211) from the carrier to the face material (100, 200), and - rolling the face material (100, 200) with adhesive thereon into a roll of linerless label material, The surface material (100, 200) comprises: - Release layer (101, 201), - a heat-sensitive layer (102, 202), - Pre-coating (103, 203), - base paper (104, 204); and - a barrier layer (105, 205), Among them, the weight of the base paper (104, 204) is 50g / m 2 Up to 90g / m 2 The coating weight (dry) of the barrier layer (105, 205) is 0.5 g / m 2 Up to 3.5g / m 2 .

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