CN115867958A - Activatable multilayer label with high bond strength and barrier properties - Google Patents

Abstract

An activatable multilayer label (1) having high bond strength and barrier properties is provided. The label comprises a facestock (10) having an upper surface (12) and a lower surface (14); a primer layer (20) having an upper surface (22) and a lower surface (24), and the primer layer (20) is placed on the lower surface (14) of the facestock (10) along the upper surface (22) of the primer layer (20); an activatable adhesive layer disposed on the primer layer along a lower surface of the primer layer. The activatable adhesive layer is activated by exposure to heat (100 ℃ to 200 ℃) to transition to a high bond forming state upon exposure to an operation that includes exposure to heat.

Description

Activatable multilayer labels with high bond strength and barrier properties

technical field

The present disclosure relates generally to labels, particularly multilayer labels, which when activated exhibit high shear and adhesion to substrates and barrier properties to migrating molecules. The present application also relates to labels containing activatable adhesives and methods of producing activatable adhesives and multilayer labels.

Background technique

Pressure sensitive adhesives (PSAs) are compositions known to provide adhesion or tack to various substrates when applied at room temperature. This adhesiveness provides an instant bond to the substrate when subjected to pressure. PSAs are generally easy to handle and have a long shelf life in solid form, so they are widely used in the manufacture of, for example, self-adhesive labels/pressure sensitive labels (PSL) and tapes.

PSA, due to its excellent mechanical properties, finds use in many applications and uses, such as pressure sensitive labels. Labels carry various written or graphic information about the product in question, including instructions and warning signs. However, when high bond strength is a priority, conventional PSLs typically focus primarily on peel strength, but suffer from compromised shear and bond strengths. Peel strength and shear strength are often competing properties.

Additionally, the labels need to be applied to multiple substrates. For example, in vehicle and automobile related applications, labels need to be applied on dashboards, sun visors, seat belts, door panels, seats/backrests, headrests, and the substrate material can be PVC leather, PU leather, ABS/PC board, PP board, textile, fabric sheepskin, cowhide, etc. In applications such as those mentioned, labels of high bond strength are generally required. Furthermore, labels used in vehicle and automotive applications are often exposed to high temperatures and adverse conditions such as high humidity, (sun) UV radiation for prolonged periods of time. Migration of small molecules such as plasticizers, dyes and additives further reduces adhesion and further reduces the label's bond strength to accompanying substrates and facestocks. Ensuring labels' chemical resistance, long-term and sustained bond strength over such wide temperature ranges and humidity conditions has been a major challenge.

Conventional pressure sensitive labels (PSLs) do not address the various challenges mentioned above. Compared with PSL, heat transfer labels or labels of similar nature, despite their ability to provide high bond strength, cannot meet the above requirements, because the heat operation performed is usually on substrates such as PVC leather, PU leather, ABS/ Deformation or damage caused by PC boards, PP boards, textiles, etc.

Contents of the invention

An activatable multilayer label is described. The label may include a facestock having an upper surface and a lower surface; a primer layer having an upper surface and a lower surface, and the primer layer is placed on the lower surface of the facestock along the upper surface of the primer layer; The lower surface of the activatable adhesive layer is disposed on the primer layer. The activatable adhesive layer can be activated to transition to a high bond-forming state when exposed to manipulation, including exposure to heat.

The activatable adhesive layer can be activated by exposure to heat at a temperature in the range of 100°C to 200°C. Exposure to heat is accompanied by the application of pressure in the range of 2 kg to 8 kg (-0.2 MPa to 0.8 MPa). Exposure to heat may be for a period of time ranging from 1 second to 20 seconds.

The face material may be selected from polyvinyl chloride (PVC), poly(ethylene terephthalate) (PET), polyolefin, polyamide, synthetic textile, synthetic leather, paper, fiberglass, polyvinylidene fluoride (PVF), metal foil, ceramics, natural leather and combinations thereof.

The thickness of the facestock may be in the range of 20 μm to 100 μm.

The primer layer may include one or more resins selected from olefin resins, polyester resins, and include one or more crosslinking agents.

The primer layer may be a barrier film selected from any one of poly(ethylene terephthalate) (PET) and polyamide (PA).

The primer layer may have a thickness in the range of 1 gsm to 10 gsm.

The activatable adhesive layer may include one or more polymer resins selected from polyurethane resins, olefin resins, and amide resins.

The activatable adhesive layer may be a hot melt adhesive, wherein the hot melt adhesive comprises a thermoplastic polymer selected from one or more synthetic rubbers and polyolefin resins, at least one selected from ester rosin and hydrocarbon resins. One or more tackifier resins, and stabilizers.

The label may further include a release liner contacting the activatable adhesive layer along opposite sides of the primer layer.

The thickness of the primer may be in the range of 1 gsm to 10 gsm, preferably in the range of 2 gsm to 5 gsm.

The olefin resin or polyester resin of the activatable adhesive may be a solvent-based resin or a water-based resin.

The olefin resin or polyester resin of the activatable adhesive may have a glass transition temperature (Tg) greater than 80°C.

The primer may include acrylate resin as main polymer, polyisocyanate, catalyst as zirconium phosphate, and additives.

The activatable adhesives with olefin and polyester resins may additionally include one or more crosslinking agents.

The polyurethane resin of the activatable adhesive may have an elongation greater than 600%.

The olefin resin may have a glass transition temperature (Tg) greater than 80°C.

The polyurethane resin may be present in an amount of at least 85% by weight of the total weight of the activatable adhesive.

The olefin resin may be present in an amount of at least 5% by weight of the total weight of the activatable adhesive.

The crosslinking agent may be present in an amount of at least 0% to 5% by weight of the total weight of the activatable adhesive.

The polyurethane resin may be a water-based polyurethane dispersion; and the olefin resin may be a water-based polyacrylic emulsion.

The crosslinking agent may be selected from one or more of isocyanate compounds and aziridine compounds.

The activatable adhesive may have a thickness in the range of 15 gsm to 60 gsm.

The hot melt adhesive may comprise at least one hydrocarbon resin as a main component; an ester rosin; a first SIS rubber having a styrene content greater than 30%; a second SIS rubber having a styrene content in the range of 20% to 30% ; Wherein the hydrocarbon resin is C5/C9 hydrocarbon resin.

The hot-melt adhesive layer may include a polyolefin resin-based hot-melt adhesive as a main component; one or more C5/C9 tackifiers as a hydrocarbon resin; and a stabilizer; wherein the polyolefin resin is modified polypropylene permanent polyolefin.

An activatable adhesive formulation is provided which may include one or more resins selected from polyurethane resins, olefin resins, amide resins and one or more crosslinking agents. Polyurethane resins can have an elongation greater than 600%. Acrylic resins may have a glass transition temperature (Tg) greater than 80°C.

The polyurethane resin may be present in an amount of at least 85% by weight of the total weight of the activatable adhesive formulation.

The olefin resin may be present in an amount of at least 5% by weight of the total weight of the activatable adhesive formulation.

The crosslinking agent may be present at least in an amount ranging from 0% to 5% by weight of the total weight of the activatable adhesive formulation.

The polyurethane resin may be a water-based polyurethane dispersion.

The olefin resin may be a water-based acrylic emulsion.

The crosslinking agent may be selected from isocyanate compounds and aziridine compounds.

The crosslinking agent can be an isocyanate.

The activatable adhesive may further include additives.

A method of labeling an article is provided. The method may comprise: providing a substrate or article having an exterior surface; providing a label as described in any preceding paragraph; removing the backing layer, if present, to expose the activatable adhesive; The outer surface of the article, the activatable adhesive of the label is adhered to the substrate or the outer surface of the article; and the activatable adhesive and the The substrate or the label in contact with the article is exposed to heating at a temperature in the range of 100°C to 200°C for a period of time in the range of 1 to 20 seconds.

Articles or substrates labeled by this method are described as mentioned in any of the preceding paragraphs. The article may be selected from vehicle components, vehicle accessories, vehicle parts, consumer products, industrial products, and electronic products.

The article or substrate labeled as described may be an automotive sun visor.

Description of drawings

The invention is described in detail below with reference to the drawing in Figure 1, which shows an activatable multilayer label and the individual layers.

Detailed ways

The present invention generally relates to multilayer labels that are activated to transition to a high bond formation state, provide improved barrier properties against migrating molecules, and attach to multiple substrates.

As noted herein, a variety of conventional PSL and thermal transfer labels are known in the art. However, many of these labels did not exhibit the desired/suitable bond strength, barrier properties and adaptability to multiple substrates.

US6228486B1 discloses a heat transfer laminate which relates to a multilayer laminate having a transparent carrier sheet which allows the underlying graphic or ink layer to be seen and precisely placed during the application of the laminate . In this way, the laminate solves the problem of the inability to precisely place the graphic layer in the prior art. In such laminates, the barrier sheet is removed along the adjacent adhesive layer, leaving the remainder of the laminate contact-adhered to the substrate by the heat-activated adhesive. The laminate has a facestock (212, 112) placed on a layer of heat-activated adhesive that facilitates clear and precise representation of graphics and printing by not allowing conformance to minor surface contours or imperfections in the substrate . The heat-activatable adhesive used 24% methyl acrylate as the main component (86%) of the heat-activatable adhesive layer.

WO2008/116033 discloses a solvent-based pressure sensitive adhesive formulation comprising a preformed acrylate polymer having at least one crosslinkable functional group, a liquid oligomer having at least one crosslinkable group (the may be polyurethane) and cross-linking agents (such as aluminum acetylacetonate, polyamides, polyvalent metal complexes). The PSA comprises about (a) 30-90% by weight of an acrylate polymer having at least one crosslinkable functional group, the acrylate polymer having a Tg of less than 200° C. and a molecular weight (Mw) greater than 20,000; (b) about 5-50% by weight of an oligomer having at least one crosslinkable functional group, wherein the oligomer is liquid at room temperature; (c) at least one crosslinking agent; wherein at least one of (a) and (b) One crosslinks in the presence of the other. However, this adhesive does not have suitable bond strength and is not compatible with various substrates, such as those used for vehicle and automobile interiors. This adhesive is not suitable to withstand harsh environments and lacks any type of barrier properties.

The disclosed activatable multilayer laminates advantageously utilize a primer layer and an activatable adhesive layer comprising a specific combination of polymeric resins which exhibit high bond strength after activation, exhibit the ability to withstand harsh environmental conditions ability and sustained bond strength at elevated temperatures, provides chemical and moisture resistance, prevents small molecule migration and adheres to a wide range of substrates.

Importantly, the inventors have discovered that the disclosed activatable multilayer labels and activatable adhesives are capable of producing bond strengths comparable to those found in structural adhesives for a variety of substrates, and The resulting bond strengths far exceed those found in PSAs. "Activation" enables labels to achieve higher bond strengths comparable to structural adhesives. The activation of multi-layer laminates is designed so that the activation operation will not have any adverse effects on the substrate material such as ABS/PC or the face material material such as PVC, all of which are characterized by poor heat resistance, high temperature and long time It is known to be easily deformed when exposed.

For the purposes of this disclosure, an activation procedure generally refers to the following: i) exposure to heat at temperatures in the range of 100°C to 200°C; ii) application in the range of 2kg to 8kg (~0.2MPa to 0.8MPa) iii) The exposure time (dwell time) of the operation is in the range of 1 second to 20 seconds.

The term "activation" of a multilayer label and/or activatable adhesive as used in this specification generally refers to the transformation of the multilayer label into a high bond-forming state by application or exposure to heat. Multilayer labels and activatable adhesives showed no or negligible loop tack at room temperature (20°C to 25°C) before activation, but after the activation operation, the multilayer The labels and adhesives exhibit high adhesion to multiple substrates, similar to that exhibited by structural adhesives. After activation, the multilayer label and/or activatable adhesive is securely affixed to the substrate. Activation also causes the entire multilayer structure, including the individual layers such as the facestock, to become fixed together and to the substrate. On the one hand, when the peel strength is tested, the facestock deforms or causes tearing, indicating that the bond strength is higher than the facestock's tear strength.

The term "chemical resistance" of a multilayer laminate as used in this specification generally refers to the ability of a multilayer label to withstand high temperature, high humidity conditions and exposure to chemicals. Without this chemical resistance, multilayer laminates can suffer from breakdown of the individual layers, such as separation between individual layers, or complete label detachment from the accompanying substrate, or facestock that becomes unstable and can be removed from The other layers of the mixture layer are removed.

Labels as described herein have utility in vehicle and auto parts. Cleaning fluids for vehicles and cars are usually soap/liquid solutions. Therefore, it is crucial to ensure that the label can withstand the soap solution and exhibit resistance (chemical resistance). In the case of no or insufficient chemical resistance, multilayer laminates will lead to the same undesirable results as mentioned above.

The term "migration" of small molecules generally refers to the migration of plasticizers, dyes, small molecules and additives from the substrate/substrate side to the surface side of the label under conditions of high temperature and high humidity under prolonged exposure, That is, the face stock side and the printing side. Often, substrates such as those made from cloth or artificial leather can appear in dark colors, causing the facestock to migrate and otherwise adversely affect the printability of the facestock layer.

While the invention has been described in detail, modifications within the spirit and scope of the invention will be apparent to those skilled in the art. In light of the foregoing discussion, relevant knowledge in the art and references discussed above in connection with the Background and Detailed Description are hereby incorporated by reference. Furthermore, it shall be understood that aspects of the present invention and parts of various embodiments as well as various features recited above and/or in the appended claims may be combined or interchanged in whole or in part. In the above descriptions of various implementations, those skilled in the art can understand that those implementations that refer to other implementations can be properly combined with other implementations. In addition, those of ordinary skill in the art will understand that the foregoing description is by way of example only, and is not intended to limit the present invention.

In one aspect of the embodiments, an activatable multilayer label is described. As shown in Figure 1, a multilayer label (1) includes a facestock (10) having an upper surface (12) and a lower surface (14). A primer layer (20) comprising an upper surface (22) and a lower surface (24) is placed below the lower surface (14) of the facestock along the upper surface (22) of the primer layer. An activatable adhesive layer is disposed on the primer layer along a lower surface (24) of the primer layer.

Multilayer labels and activatable adhesives show no or negligible loop tack at room temperature (approximately 20°C to 25°C), but after activation operations, multilayer labels and adhesives show High adhesion to multiple substrates, similar to that exhibited by structural adhesives. The intended activatable multilayer label and/or activatable adhesive is non-tacky (no or negligible loop tack) and dry on the activatable adhesive side prior to performing the activation operation , in order to facilitate the placement or movement of the label or to correct the precise position/orientation of the label bonded to the substrate. The labels so produced allow for easy handling and application by hand. The inventors were able to design this activatable multilayer label by balancing the degree of initial tack and the final bond (adhesive bond) obtained after the activation operation has been performed.

The multilayer label, via the activatable adhesive, is activated to transition to a high bond forming state upon exposure to manipulations involving exposure to heat. The multilayer labels exhibit bond strengths comparable to those found in structural adhesives. Importantly, the bond strengths mentioned herein are produced for a variety of different substrates, including PVC leather, PU leather, ABS/PC board, PP board, textiles, fabric sheepskin, cowhide, etc. The bond strengths obtained far exceed those found in PSAs because, according to the embodiments herein, peel testing resulted in tearing of the facestock.

According to one embodiment, the activation of the multilayer laminate is intended to be carried out in such a way that the activation operation does not adversely affect the substrate material such as ABS/PC or the face material such as PVC, all of which It is known to have poor heat resistance and is easily deformed under high temperature and prolonged exposure.

Activation is capable of producing high bond strengths as described above, and activation is carried out after operations comprising: i) exposure to heating at temperatures in the range of 100°C to 200°C; ii) application of 2kg to 8kg (˜ 0.2 MPa to 0.8 MPa) in the range of pressure; iii) operating exposure time (dwell time) in the range of 1 second to 20 seconds. The heating temperature may be in the range of 110°C to 145°C, or in the range of 115°C to 140°C, or in the range of 120°C to 135°C. In terms of upper limits, the heating temperature may be lower than 190°C, or lower than 170°C, or lower than 150°C, or lower than 130°C. In terms of the lower limit, the heating temperature may be greater than 100°C, or greater than 110°C, or greater than 120°C, or greater than 130°C. The applied pressure may be in the range of 2kg to 8kg (~0.2MPa to 0.8MPa). Exposure times may range from 1 second to 5 seconds, 2 seconds to 10 seconds, 3 seconds to 20 seconds. Activation can be achieved with or without the application of pressure.

Activation as described herein results in melting with heat of the activatable adhesive that was initially and/or remained solid prior to activation. The melted activatable adhesive then causes wetting of the substrate to which the label is to be attached. As the heating ceases, the activatable adhesive cools and undergoes crystallization of the polymer resin involved. According to one embodiment, the activatable adhesive then becomes solid again and forms a strong bond with a high bond strength to the substrate. The activatable multilayer label and/or the activatable adhesive thus exhibit the properties of a structural adhesive and similar bond strength. When the bond strength of an activatable multilayer label/adhesive is assessed using the "cross-hatch" adhesion test method well known in the paint or related coating art, when the label is removed by hand, the facestock (PVC) tears and Substrates (such as leather, cloth) will be damaged. The cross-cut method described below should refer to: GMW14573-1b, and the test specification is GMW14829 (3mm) (General Motors).

It has been found that for activation of multilayer labels and/or activatable adhesives, even though higher temperatures, longer exposure/dwell times and higher pressures have a positive effect on bond strength, higher temperatures or exposure Time is not good for a number of commonly used substrate materials. The inventors succeeded in balancing the activation parameters without compromising the desired bond strength required after activation, and adapting to a large number of substrates without adverse effects from the activation step employed.

Another significant advantage of the activatable adhesives as designed herein is that the formulated activatable adhesives exhibit longer storage times after formulation under airtight and room temperature conditions. This provides greater economic and logistical advantages to allow greater processing flexibility.

In one embodiment, the activatable multilayer label further comprises a release liner underlying the activatable adhesive layer.

According to an embodiment herein, the face material layer is selected from plastic films, such as PVC, PET, nylon and the like. This face material has a ten-year weather resistance rating. Regarding the thickness, the thickness of the surface material is 20 μm to 100 μm, 25 μm to 50 μm, and 30 μm to 45 μm. As an upper limit, the thickness may be less than 100 μm, or less than 80 μm, or less than 60 μm, or less than 50 μm. As for the lower limit, according to embodiments herein, the thickness may be greater than 5 μm or greater than 10 μm or greater than 15 μm or greater than 20 μm.

Provides a primer layer (which may also be referred to as a laminate layer) below the facestock layer in multilayer labels for excellent interlayer fastness, with the facestock layer on one side and the activatable adhesive layer (which is on layer of activatable adhesive) on the other side. According to embodiments herein, the primer layer is further used to prevent unwanted migration of plasticizers, dyes and small molecules from the substrate side to the facestock/print side.

In some embodiments, the primer layer includes, as the main polymer, a polymer resin selected from solvent- or water-based olefin resins (such as acrylic resins) or polyester resins and one or more crosslinking agents. The crosslinking agent may be selected from isocyanate, aziridine or epoxy or other crosslinking agents.

According to one embodiment, the polymer resin used for the primer layer, such as an acrylic resin or a polyester resin, is chosen to have a high glass transition temperature (Tg), preferably exhibiting a (Tg) greater than 80°C. It was found that a polymer resin having such a glass transition temperature can form a dense network structure after a crosslinking reaction using a crosslinking agent. The resulting network structure was found to have sufficient modulus to hold back small molecular species such as plasticizers, dyes and additives often present in the substrate when the label is exposed to high temperatures (100°C-120°C) for extended periods of time. ) migrates to the label surface (on the face stock side, which may be PVC).

The primer layer as described above additionally includes one or more inorganic fillers according to the embodiments herein - a primer that is mixed by physical means, coated, dried and cured, has good barrier properties and firmness between layers Spend.

In some embodiments, the primer layer is a barrier film selected from any one of poly(ethylene terephthalate) (PET), polyamide (PA), NY, and the like. Face materials such as PVC film can be laminated with PET or PA using any known lamination process, and this arrangement also prevents small molecular substances such as plasticizers, dyes and additives from being exposed to high temperatures for a long period of time. Migrate to label surface. Prevention of color/dye migration by employing the primer layer described herein is one of the significant advantages of the subject matter. The barrier film can be placed on the facestock using a laminating adhesive such as LIOFOL 2788-21 available from Henkel or the sample 5 adhesive described in Table 2 of the Experimental and Examples section. The use of a barrier film results in a higher thickness of the label and, for example, needs to be adjusted according to the actual application requirements when better softness and flexibility are required for the substrate involving clothing or fabrics.

The primer layer has a thickness in the range of 1 gsm to 10 gsm, 2 gsm to 8 gsm, 3 gsm to 7 gsm. In terms of upper limits, the primer layer has a thickness of less than 10 gsm, or less than 8 gsm, or less than 6 gsm, or less than 5 gsm. According to embodiments herein, with regard to the lower limit, the primer layer has a thickness greater than 1 gsm, or greater than 3 gsm, or greater than 5 gsm, or greater than 7 gsm, or greater than 9 gsm.

In some embodiments, the activatable binder is selected from polymer resins including polyurethane resins, olefin resins such as polyolefin resins, and amide resins. The activatable adhesives can be water-based, solvent-based or hot melt systems.

According to embodiments herein, the activatable adhesive additionally includes one or more crosslinking agents.

In some embodiments, the primary polymer resin for the activatable adhesive is a polyurethane dispersion (PUD), which is preferably an aliphatic polyurethane with an elongation greater than 600%. The inventors have discovered that such elongation properties are needed in order to ensure that i) the activatable adhesive layer has a lower thermal activation temperature during label use/application to a substrate, and ii) the label/activatable adhesive can be Applies to a broad spectrum of substrate materials in less time. Without being bound by theory, it is believed that this elongation property contributes to the label/activatable adhesive having sufficient wettability to the substrate where the label will be applied within a shorter dwell time, and when Labels/activatable adhesives are capable of forming high bond strengths when returned to normal temperature after activation/heating.

Without being bound by theory, it is believed that elongations below 600% indicate insufficient adhesion and/or adhesion to a diverse range of substrate materials after activation. While an elongation greater than 1200% indicates improved and higher adhesion, such elongation results in an adhesive layer with unacceptable tack, which is not as previously contemplated herein. In order to balance the tack, a large amount of hard components is required to reduce the tacky properties, but this has an adverse effect on the adhesion. Therefore, the elongation of the aliphatic polyurethane is in the range of 600% to 1200%, 700% to 1000%, 800% to 900%. As an upper limit, the elongation is less than 1200%, or less than 1000%, or less than 800%. According to embodiments herein, with respect to the lower limit, the elongation is greater than 600%, or greater than 800%.

In some embodiments, the polyurethane resin is present in an amount of at least 85% by weight of the total weight of the activatable adhesive. Polyurethane resins have a solids content of at least 30%.

In another embodiment, the polyolefin resin of the activatable adhesive layer is an acrylic resin selected to have a glass transition temperature (Tg) greater than 80°C. This property of acrylic resins allows the activatable adhesive to function as a release resin. In other words, an acrylic with such a high Tg has the desired tendency to crystallize, which in turn effectively causes the tackiness of the activatable adhesive to decrease prior to activation. It has also been found that the Tg mentioned herein still has minimal negative impact on the degree of adhesion (adhesive bonding) required after activation of the above mentioned substrates.

According to embodiments herein, a relatively small amount of acrylic resin component is added to a polyurethane dispersion (PUD) to reduce the initial viscosity of the primary polymer PUD while reducing the detrimental effect of reduced cohesive strength of the activatable adhesive after activation .

In some embodiments, the olefin resin is present in an amount of at least 5% by weight of the total weight of the activatable adhesive. The solids content of the olefin resin is at least 30%.

In some embodiments, when the intended substrate is a polypropylene-based substrate, the activatable adhesive is a hot melt adhesive.

The hot melt adhesive is selected from synthetic rubbers such as SIS rubbers as thermoplastic polymers, which may have different SIS blocks with different styrene contents, ester rosins and hydrocarbon resins as tackifiers and stabilizers. According to embodiments herein, one grade of SIS rubber involves a styrene content greater than 30%, while the other grade involves SIS rubber with a styrene content of 20% to 30%.

In another embodiment, the hot melt adhesive comprises, as the thermoplastic polymer, one or more polyolefins in the form of modified polypropylene and having a melt index (MI) greater than 300, a hydrocarbon resins and stabilizers.

In the case of hot melt adhesives whether they involve rubber-based or polyolefin resin-based adhesives, by selecting the degree of crystallinity of the polyolefin polymers involved or by balancing the proportion of hard blocks of the synthetic rubber, in short Achieving the desired wettability for a large number of different substrate materials within a time window. This results in achieving the expected bond strength as previously described and also satisfying the resistance when the activatable adhesive is returned to normal temperature.

In a preferred embodiment, the crosslinker selected for the activatable adhesive layer may be an isocyanate crosslinker. It was found that the specific structure of the isocyanate, which includes hard and soft segments, and the urea linkages formed after crosslinking, showed little effect on the activation temperature (what does that mean?), while further improving the heat-activated viscosity. Mixture layer (what does this mean?). The selected cross-linking agent further increases the bond strength, which in turn increases chemical resistance, high temperature resistance and humidity resistance.

In some embodiments, the crosslinker is present in an amount of at least 1% by weight or less of the total weight of the activatable adhesive.

The activatable adhesive has a thickness in the range of 15 gsm to 60 gsm, 20 gsm to 50 gsm, 25 gsm to 30 gsm. In terms of upper limits, the thickness of the activatable adhesive is less than 60 gsm, or less than 50 gsm, or less than 40 gsm, or less than 30 gsm, and less than 20 gsm. According to embodiments herein, with regard to the lower limit, the thickness of the activatable adhesive is greater than 15 gsm, or greater than 20 gsm, or greater than 30 gsm, or greater than 40 gsm, or greater than 50 gsm.

In one embodiment, the construction of a multilayer label (composite structure) is made using a method employing a facestock layer, a primer layer and an activatable layer (each individual layer) as follows (which may be referred to as a composite process) : Surface material—as the surface material of PVC and has a thickness of 50 μm PVC surface material, first coat the primer layer on one side of the surface material. The thickness of the primer layer may range from 2gsm to 5gsm. The primer-coated facestock can then be aged at room temperature for 4 to 5 days. This facestock layer coated with the primer layer is then coated with an activatable adhesive and placed on the primer side of the facestock with the laminate primer.

It was surprisingly found that both the primer layer and the activatable adhesive, as designed in this context, work together in a synergistic manner to demonstrate success in preventing the migration of small molecules, especially colors and dyes, from the substrate side to the surface (surface). material side) migration. The advantage of using a primer is that the overall thickness of the label is thinner and the obtained bond strength meets the requirements. than composite technology.

Experiments and Examples

Table 1, for example, represents samples of different formulations of activatable adhesives employed in activatable multilayer labels for substrates other than polypropylene-based substrates. Tables 1 to 3 demonstrate the benefits and performance levels of labels/activatable adhesives. A hyphen appearing in the table indicates an item not in the corresponding formulation.

Table 1

Adhesion at room temperature (before activation) and bond strength after activation (adhesion-bond strength): Activatable multilayer labels prepared with different formulations of activatable adhesives shown in Table 1, when the labels are applied to different substrates When on the main body of the product, use the cross-hatch tape adhesion test method to test the loop initial adhesion (room temperature viscosity), and the adhesion fastness after activation operation (at 140°C, pressure 4kg~0.4MPa, exposure for 3 seconds). The results are shown in Table 2 with the following representations: x - poor performance; Δ - fair performance; □ - good performance; and ◎ - best performance. The rest of the tables provided below have the same notation to indicate the range of performance evaluated.

Table 2

×—poor performance; △—general performance; □—good performance; and ◎—best performance

High temperature resistance, high humidity resistance and chemical resistance performance test: The different sample preparations of the examples mentioned in Table 3 were combined with PVC leather substrates and blue fabric substrates, and then subjected to activation operations, including heating to 140°C Temperature, pressure 4kg ~ about 0.4MPa, exposure for 3 seconds. The labels are then checked for wrinkle formation (which is not desired) and adhesive/bond strength. The labels are also scrubbed with Sonax detergent. The properties listed in Table 3 were evaluated using the cross-hatch tape adhesion test method.

table 3

×—poor performance; △—general performance; □—good performance; and ◎—best performance

Table 4 lists different sample formulations of activatable adhesives in the form of hot melt adhesives for substrates comprising polypropylene based materials.

Table 4

Room temperature tack (before activation) and bond strength/cohesion (cohesion strength): These mentioned properties were tested for the sample adhesive formulations exemplified in Table 4, and labels with this formulation were attached to polypropylene panels , and then heated at 140°C, under a pressure of 4kg to about 0.4MPa, and exposed for 3 seconds for activation. The properties were evaluated using the cross-hatch tape adhesion test method and the properties obtained are listed in Table 5 below.

table 5

×—poor performance; △—general performance; □—good performance; and ◎—best performance

The different sample formulations of the primer layer and the primer layer are exemplified in Table 6 as follows:

Table 6

Zirconium phosphate is used as flake powder to reduce small molecule migration.

Migration (color/dye) performance and intercoat fastness of primer layer: The activatable adhesives of the samples of Examples 12 to 17 in Table 6 and the sample of Example 5 were used in a multilayer label construction. The labels thus constructed are used to bond with dark substrates such as PVC leather and ABS/PC panels (which facilitates color migration studies), and then by heating at 140°C, 140°C, pressure from 4kg to about 0.4MPa, Expose for 3 seconds to activate. After this, the labels were exposed to high temperatures of about 90° C. and high humidity of about 90% humidity for a period of 7 days (this was to replicate the label use environment in the intended application, albeit under degraded conditions). A color shift resistance test by visual observation and an interlayer fastness test using a cross-hatch tape adhesion test method were conducted. The results obtained are listed in Table 7.

Table 7

The activatable adhesive of Example 5 was used to evaluate different thicknesses of the barrier film when used as a primer layer, exemplified in Table 8.

Table 8

sample example Example 18 Example 19 Example 20 Example 21 Example 22 Example 23 barrier film 5um PET 5um PA 12um PET 12um PA 20um PET 20um PA

Migration (color) performance and intercoat fastness of the primer layer: The activatable adhesives from the samples of Examples 18 to 23 in Table 8 and the sample in Example 5 were used in multilayer label construction. The labels thus constructed were used for bonding to dark substrates such as PVC leather and ABS/PC panels (which facilitated color migration studies) and then activated by exposure to heat at 140°C for 3 seconds. After this, the labels were exposed to high temperatures of about 90° C. and high humidity of about 90% humidity for a period of 7 days (this was to replicate the label use environment in the intended application, albeit under degraded conditions). A color migration resistance test by visual observation and an interlayer fastness test using a cross-hatch tape adhesion test method were conducted. The results obtained are listed in Table 9.

Table 9

Implementation

Exemplary embodiments provided herein are activatable multilayer labels as follows:

An activatable multilayer label comprising: a facestock having an upper surface and a lower surface; a primer layer having an upper surface and a lower surface, and the primer layer is placed on top of the facestock along the upper surface of the primer layer On the lower surface; the activatable adhesive layer is disposed on the primer layer along the lower surface of the primer layer. The activatable adhesive layer is activated to transition to a high bond-forming state upon exposure to manipulations including exposure to heat.

The activatable adhesive layer described in paragraph [0099] is activated by exposure to heat at a temperature in the range of 100°C to 200°C.

The exposure to heat described in paragraph [0099] is accompanied by the application of pressure in the range of 2 kg to 8 kg (-0.2 MPa to 0.8 MPa).

The heating described in paragraph [0099] is performed for a period of time ranging from 1 second to 20 seconds.

The face material described in paragraph [0099] is selected from the group consisting of polyvinyl chloride (PVC), poly(ethylene terephthalate) (PET), polyolefins, polyamides, synthetic textiles, synthetic leather, paper, At least one of glass fiber, polyvinylidene fluoride (PVF), metal foil, ceramics, natural leather, and combinations thereof.

The facestock described in paragraph [0099] has a thickness in the range of 20 μm to 100 μm.

The primer layer described in paragraph [0099] includes one or more resins selected from olefin resins, polyester resins, and includes one or more crosslinking agents.

The primer layer described in paragraph [0099] is a barrier film selected from any one of poly(ethylene terephthalate) (PET), polyamide (PA).

The primer layer described in paragraph [0099] has a thickness in the range of 1 gsm to 10 gsm.

The activatable adhesive layer described in paragraph [0099] includes one or more polymer resins selected from polyurethane resins, olefin resins, and amide resins.

The activatable adhesive layer described in paragraph [0099] is a hot melt adhesive. The hot melt adhesive includes a thermoplastic polymer selected from one or more of synthetic rubbers and polyolefin resins, a tackifier resin selected from at least one or more of ester rosins and hydrocarbon resins, and a stabilizer.

The label of paragraph [0099], further comprising a release liner contacting the activatable adhesive layer along opposite sides of the primer layer.

The primer described in paragraph [0099] has a thickness in the range of 1 gsm to 10 gsm, preferably 2 gsm to 5 gsm.

The primer layer of paragraph [00105], wherein the olefin resin or the polyester resin is a solvent-based resin or a water-based resin.

The olefinic resin or polyester described in paragraph [00105] has a glass transition temperature (Tg) greater than 80°C.

The primer layer of paragraph [00105], wherein the primer includes an acrylic resin as the main polymer, polyisocyanate, a catalyst as zirconium phosphate, and an additive.

The activatable adhesive described in paragraph [00108] further includes one or more crosslinking agents.

The polyurethane resin described in paragraph [00108] has an elongation greater than 600%.

The olefin resin described in paragraph [00108] has a glass transition temperature (Tg) greater than 80°C.

The polyurethane resin described in paragraph [00108] is present in an amount of at least 85% by weight of the total weight of the activatable adhesive.

The olefinic resin described in paragraph [00108] is present in an amount of at least 5% by weight of the total weight of the activatable adhesive.

The crosslinking agent described in paragraph [00115] is present in an amount of at least 0% to 5% by weight of the total weight of the activatable adhesive.

The polyurethane resin of paragraph [00108] is a water-based polyurethane dispersion; and wherein the olefin resin is a water-based polyacrylic emulsion.

The crosslinking agent described in paragraph [00115] is selected from one or more isocyanate compounds and aziridine compounds.

The activatable described in paragraph [00108] has a thickness in the range of 15 gsm to 60 gsm.

The hot melt adhesive described in paragraph [00109] comprises at least one hydrocarbon resin as a major component; an ester rosin; a first SIS rubber having a styrene content of greater than 30%; a styrene content of 20% to 30% of the second SIS rubber; wherein the hydrocarbon resin is a C5/C9 hydrocarbon resin.

The hot melt adhesive described in paragraph [00109] comprises a polyolefin resin-based hot melt adhesive as a main component; one or more C5/C9 tackifiers as a hydrocarbon resin; and a stabilizer; wherein The polyolefin resin is polypropylene modified polyolefin.

There is provided an activatable adhesive formulation comprising one or more resins selected from polyurethane resins, olefin resins, amide resins and one or more crosslinking agents. Polyurethane resin has an elongation of over 600%. Acrylic resins have a glass transition temperature (Tg) greater than 80°C.

The polyurethane resin described in paragraph [00126] is present in an amount of at least 85% by weight of the total weight of the activatable adhesive formulation.

The acrylic resin described in paragraph [00126] is present in an amount of at least 5% by weight of the total weight of the activatable adhesive formulation.

The crosslinking agent described in paragraph [00126] is present in an amount of at least 0% to 5% by weight of the total weight of the activatable adhesive formulation.

The polyurethane resin described in paragraph [00126] is a water-based polyurethane dispersion.

The acrylic resin described in paragraph [00126] is a water-based acrylic emulsion.

The crosslinking agent of any one of the preceding paragraphs described in paragraph [00126] is selected from isocyanate compounds and aziridine compounds.

The crosslinking agent described in paragraph [00126] is an isocyanate.

The activatable adhesive described in paragraph [00126] further includes additives.

A method of labeling an article comprising: providing a substrate or article having an outer surface; providing the label of any of the preceding paragraphs; removing the liner layer, if present, to expose an activatable adhesive; The activatable adhesive contacts the outer surface of the article, the activatable adhesive of the label is adhered to the substrate or the outer surface of the article; The heating of the label at a temperature in the range of 100°C to 200°C under a pressure of 4kg to 8kg for a period of time in the range of 1 to 20 seconds.

An article or substrate labeled by the method described in paragraph [00135], wherein the article is selected from a vehicle component, a vehicle accessory, a vehicle part, a consumer product, an industrial product, and an electronic product.

The labeled article or substrate described in the preceding paragraph of [00135] or [00136] is an automotive sun visor.

While the invention has been described in detail, modifications within the spirit and scope of the invention will be apparent to those skilled in the art. In light of the foregoing discussion, relevant knowledge in the art, and the disclosures of the references discussed above in connection with the Background and Detailed Description are hereby incorporated by reference. Furthermore, it should be understood that aspects of the present invention and parts of various embodiments as well as various features recited below and/or in appended claims may be combined or interchanged in whole or in part. In the above descriptions of various implementations, those skilled in the art can understand that those implementations that refer to other implementations can be properly combined with other implementations. In addition, those of ordinary skill in the art will appreciate that the above description is exemplary only and is not intended to limit the present invention.

Claims (38)

1. An activatable multilayer label, said label comprising:

a facestock having an upper surface and a lower surface;

a primer layer having an upper surface and a lower surface, and the primer layer is placed on the lower surface of the facestock along the upper surface of the primer layer;

an activatable adhesive layer disposed on the primer layer along the lower surface of the primer layer; and is

Wherein the activatable adhesive layer is activated to transition to a high bond forming state upon exposure to an operation comprising exposure to heat.

2. The label of claim 1 wherein the activatable adhesive layer is activated by exposure to heat at a temperature in the range of from 100 ℃ to 200 ℃.

3. The label of claim 1 wherein the exposure to heat is accompanied by the application of a pressure in the range of 2kg to 8 kg.

4. The label of claim 1 wherein the exposure to heat is for a period of time in the range of 1 second to 20 seconds.

5. The label of claim 1 wherein the facestock is at least one selected from the group consisting of polyvinyl chloride (PVC), poly (ethylene terephthalate) (PET), polyolefins, polyamides, synthetic textiles, synthetic leather, paper, fiberglass, polyvinylidene fluoride (PVF), metal foil, ceramics, natural leather, and combinations thereof.

6. The label of claim 1 wherein the facestock has a thickness in the range of 20 μ ι η to 100 μ ι η.

7. The label of claim 1 wherein the primer layer comprises one or more resins selected from olefin resins, polyester resins, and includes one or more crosslinkers.

8. The label of claim 1 wherein the primer layer is a barrier film selected from any one of polyethylene terephthalate (PET), polyamide (PA).

9. The label of claim 1 wherein the primer layer has a thickness in the range of 1gsm to 10 gsm.

10. The label of claim 1 wherein the activatable adhesive layer comprises one or more polymeric resins selected from the group consisting of polyurethane resins, olefin resins, and amide resins.

11. The label of claim 1 wherein the activatable adhesive layer is a hot melt adhesive, wherein the hot melt adhesive comprises a thermoplastic polymer selected from one or more synthetic rubbers and polyolefin resins, a tackifier resin selected from at least one or more of ester rosins and hydrocarbon resins, and a stabilizer.

12. The label of claim 1 further comprising a release liner contacting the activatable adhesive layer along opposite sides of the primer layer.

13. The label of claim 7 wherein the olefin resin or the polyester resin is a solvent-based resin or a water-based resin.

14. The label of claim 7 wherein the olefin resin or the polyester has a glass transition temperature (Tg) greater than 80 ℃.

15. The label of claim 7 wherein the primer includes an acrylic as the primary polymer, a polyisocyanate, a catalyst as zirconium phosphate, and additives.

16. The label of claim 10 wherein the activatable adhesive further comprises one or more crosslinkers.

17. The label of claim 10 wherein the polyurethane resin has an elongation of greater than 600%.

18. The label of claim 10 wherein the acrylic resin has a glass transition temperature (Tg) greater than 80 ℃.

19. The label of claim 10 wherein the polyurethane resin is present in an amount of at least 85 weight percent of the total weight of the activatable adhesive.

20. The label of claim 10 wherein the acrylic resin is present in an amount of at least 5 weight percent of the total weight of the activatable adhesive.

21. The label of claim 16 wherein the crosslinking agent is present in an amount of at least 0 to 5 weight percent of the total weight of the activatable adhesive.

22. The label of claim 10 wherein the polyurethane resin is a water-based polyurethane dispersion; and wherein the olefin resin is a water-based polyacrylic acid emulsion.

23. The label of claim 16 wherein the crosslinking agent is selected from one or more of isocyanate compounds and aziridine compounds.

24. The label of claim 10 wherein the activatable adhesive has a thickness in the range of 15gsm to 60 gsm.

25. The label of claim 11 wherein the hot melt adhesive comprises as a major component at least one hydrocarbon resin; an ester rosin; a first SIS rubber having a styrene content greater than 30%; a second SIS rubber having a styrene content in the range of 20% to 30%; wherein the hydrocarbon resin is a C5/C9 hydrocarbon resin.

26. The label of claim 11 wherein the hot melt adhesive layer comprises as a major component a polyolefin resin based hot melt adhesive; one or more C5/C9 tackifiers as hydrocarbon resins; and a stabilizer; wherein the polyolefin resin is polypropylene modified polyolefin.

27. An activatable adhesive formulation comprising one or more resins selected from polyurethane resins, olefin resins, amide resins and one or more crosslinkers;

wherein the polyurethane resin has an elongation of more than 600%; and is

Wherein the olefin resin has a glass transition temperature (Tg) of greater than 80 ℃.

28. The activatable adhesive formulation of claim 27, wherein the polyurethane resin is present in an amount of at least 85 weight percent of the total weight of the activatable adhesive formulation.

29. The activatable adhesive formulation of claim 27, wherein the olefin resin is present in an amount of at least 5 weight percent of the total weight of the activatable adhesive formulation.

30. The activatable adhesive formulation of claim 27, wherein the crosslinking agent is present in an amount of at least 0% to 5% by weight of the total weight of the activatable adhesive formulation.

31. The activatable adhesive formulation of claim 27, wherein said polyurethane resin is a water-based polyurethane dispersion.

32. The activatable adhesive formulation of claim 27, wherein the olefin resin is a water-based acrylic emulsion.

33. The activatable adhesive formulation of claim 27, wherein the crosslinking agent is selected from the group consisting of isocyanate compounds and aziridine compounds.

34. The activatable adhesive formulation of claim 27, wherein the crosslinking agent is an isocyanate.

35. The activatable adhesive formulation of claim 27, wherein the activatable adhesive further comprises an additive.

36. A method of labeling an article, the method comprising:

a. providing a substrate or article having an outer surface;

b. providing a label according to any one of claims 1-26;

c. removing the liner layer, if present, to expose the activatable adhesive;

d. adhering the activatable adhesive of the label to the outer surface of the substrate or the article by contacting the activatable adhesive to the outer surface of the article; and

e. exposing a label in contact with the substrate or the article by the activatable adhesive to heat at a temperature in the range of 100 ℃ to 200 ℃ for a period of time in the range of 1 to 20 seconds at a pressure in the range of 4kg to 8 kg.

37. An article or substrate labeled by the method of claim 36, wherein the article is selected from the group consisting of a vehicle part, a vehicle accessory, a vehicle part, a consumer product, an industrial product, and an electronic product.

38. An article or substrate labeled according to the methods of claims 36 and 37 is an automotive sun visor.

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