Biodegradable adhesive tape, biodegradable adhesive composition, and production method for biodegradable adhesive tape

Abstract

A biodegradable adhesive tape, a biodegradable adhesive composition, and a production method for the biodegradable adhesive tape. The biodegradable adhesive tape comprises: the biodegradable adhesive composition, comprising an acrylic acid adhesive and a polyurethane dispersant, wherein the ratio of the dry weight of the polyurethane dispersant to the wet weight of the biodegradable adhesive composition is at least 8% or above, and the ratio of the dry weight of the polyurethane dispersant to the dry weight of the acrylic acid adhesive is not more than 40%; and a biodegradable backing film. The compostable degradation rate of the biodegradable adhesive tape tested according to GB / T 19277.1 is at least greater than or equal to 90% in 180 days. The adhesive tape and the adhesive composition have the advantages that the raw materials are easy to obtain, the preparation is simple and convenient, and a good adhesion effect and a biodegradation effect are both achieved.

Description

Biodegradable adhesive tape, biodegradable adhesive composition, and method for producing biodegradable adhesive tape Technical Field

[0001] The present invention relates to an adhesive tape, an adhesive composition used for the adhesive tape, and a method for making the adhesive tape, and in particular to a biodegradable adhesive tape, an adhesive composition used for the biodegradable adhesive tape, and a method for making the biodegradable adhesive tape. Background Art

[0002] As people's environmental awareness grows, the recycling and reuse of materials and various resources is gaining increasing attention. The decomposition of resources or materials has become a key research area. By decomposing materials, their impact on the environment can be reduced, and even converted into reusable resources, biodegradability is a key area of ​​research.

[0003] Adhesives and tapes are common items in everyday life. For example, proper packaging is often required during the transportation of goods. To ensure a tight seal and protect the goods, adhesives and tapes are often used. However, most adhesives and tapes are not recyclable. Currently, there are tapes made with biodegradable backing films, but the adhesives themselves are not biodegradable. Even if biodegradable tapes are available, their degradation rate and performance are not easily balanced. In other words, the range of biodegradable tapes is still limited.

[0004] CN106574036A discloses biodegradable pressure-sensitive adhesives achieved by chemical crosslinking of polyurethane prepolymers and by formulating a pressure-sensitive adhesive having one or more such polyurethanes as a major component.

[0005] CN107523253A provides a biodegradable pressure-sensitive adhesive, but the pressure-sensitive adhesive is provided as a dispersion in at least one solvent to prepare an adhesive tape. It is generally known that the use of solvents is generally not environmentally friendly.

[0006] CN106459694A relates primarily to a biodegradable surface-protecting adhesive tape comprising at least 60% by weight of at least one polyurethane, which can be easily and largely residue-freely separated from the surface to be protected and the adhesive has sufficient cohesion.

[0007] CN109957372A provides a polyester hot melt pressure sensitive adhesive, but the preparation of the hot melt adhesive generally requires special equipment.

[0008] There are also some technologies that make pressure-sensitive adhesives from naturally occurring raw materials, such as CN106978116A.

[0009] Summary of the Invention

[0010] Given that existing technologies may require different adhesive systems, such as solvent systems, hot melt adhesive systems, or the use of natural raw materials to produce biodegradable tapes or adhesives, the production process is relatively complex. Acrylic adhesives are commonly used in pressure-sensitive adhesives, but generally do not achieve biodegradability. However, the present invention provides a biodegradable adhesive, tape, and method for producing the same. These adhesives utilize a water-based acrylic adhesive as the main component and incorporate a polyurethane dispersant. In addition to achieving excellent tape performance, they are surprisingly found to have a good biodegradability rate. In other words, this invention provides a tape and adhesive combination that is easily accessible, simple to prepare, and achieves both good adhesion and biodegradability.

[0011] To achieve the above-mentioned process effects, the technical solution of the present invention is as follows: a biodegradable tape, comprising: a biodegradable adhesive composition and a biodegradable backing film, wherein the biodegradable adhesive composition includes: an acrylic adhesive and a polyurethane dispersant, the dry weight of the polyurethane dispersant relative to the wet weight of the biodegradable adhesive composition being at least 8%, and the dry weight of the polyurethane dispersant relative to the dry weight of the acrylic adhesive being no more than 40%; and the composting degradation rate of the biodegradable tape, as tested in accordance with GB / T 19277.1, is at least greater than or equal to 90% after 180 days.

[0012] In some embodiments, the biodegradable backing film can be selected from a multi-layer backing of one or a combination of polylactic acid film, kraft paper and cellophane.

[0013] In some embodiments, the biodegradable backing film may be a biaxially oriented biodegradable backing film.

[0014] In some embodiments, the acrylic adhesive comprises a water-based random copolymer, wherein monomer units thereof are selected from one or more of acrylate, methacrylate, acrylic acid, methacrylic acid, acrylamide, and methacrylamide.

[0015] In some embodiments, the polyurethane dispersant is an aqueous dispersant, such as an anion-modified polyurethane dispersant.

[0016] In some embodiments, the biodegradable tape further comprises a tackifier, wherein the tackifier can be selected from one or more of rosin resin, hydrogenated rosin resin and terpene phenolic resin.

[0017] In some embodiments, the biodegradable tape has a Room Temperature Shear Force of at least 24 hours as tested in accordance with GBT 4851-2014A; a 180° Peel Adhesion of at least 2.5 N / cm as tested in accordance with GBT 2792-2014; and an Initial Tack of at least a size 12 ball as tested in accordance with GB / T 4582-2002.

[0018] In some embodiments, the biodegradable adhesive composition has a thickness of 10 μm-200 μm after drying.

[0019] In some embodiments, the biodegradable tape further includes a release layer.

[0020] This case also provides a biodegradable adhesive composition, which includes: an acrylic adhesive and a polyurethane dispersant, wherein the dry weight of the polyurethane dispersant is at least 8% relative to the wet weight of the biodegradable adhesive composition, and the dry weight of the polyurethane dispersant is no more than 40% relative to the dry weight of the acrylic polymer, wherein the composting degradation rate of the biodegradable adhesive composition tested in accordance with GB / T 19277.1 is at least greater than or equal to 90% after 180 days.

[0021] This case also involves a method for making a biodegradable tape, comprising: providing a biodegradable backing film and a biodegradable adhesive composition; applying the biodegradable adhesive composition to the biodegradable backing film, wherein the biodegradable adhesive composition comprises an acrylic adhesive and a polyurethane dispersant, the dry weight of the polyurethane dispersant relative to the wet weight of the biodegradable adhesive composition being at least 8%, and the dry weight of the polyurethane dispersant relative to the dry weight of the acrylic polymer being no more than 40%; and drying and dehydrating the biodegradable backing film coated with the biodegradable adhesive composition to obtain the biodegradable tape, wherein the composting degradation rate of the biodegradable tape as tested in accordance with GB / T 19277.1 is at least greater than or equal to 90% after 180 days. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a schematic structural diagram of a biodegradable tape according to an embodiment of the present invention;

[0023] FIG2 is a schematic structural diagram of a biodegradable tape according to another embodiment of the present invention;

[0024] FIG3 is a flow chart of making a biodegradable tape according to an embodiment of the present invention; and

[0025] FIG4 is a flow chart of manufacturing a biodegradable tape according to another embodiment of the present invention. DETAILED DESCRIPTION

[0026] The following will be described in more detail with reference to the accompanying drawings, with reference to some specific embodiments of the present invention. It should be understood that those skilled in the art will be able to conceive of various other embodiments and make modifications thereto based on the teachings of this specification without departing from the scope or spirit of the present invention. Therefore, the following specific embodiments are merely illustrative and not restrictive.

[0027] Unless otherwise indicated, all numbers used in this specification and claims expressing feature sizes, quantities, and physical properties should be understood as being modified by the term "about." Therefore, unless otherwise indicated, the numerical parameters listed in this specification and the appended claims are approximate values, and based on the teachings of the present invention, a person of ordinary skill in the art will be able to appropriately modify these approximate values ​​to obtain the desired properties. Numerical ranges expressed as endpoints include all numbers within the range; for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, and 5, etc. In addition, "biodegradable" as used in this case means that the ultimate aerobic biodegradability and disintegration degree of the material within the specified test period, as tested using the test method specified in the Chinese national standard GB / T 19277.1-2011, exceeds 90%.

[0028] Please refer to Figure 1, which is a schematic diagram of the structure of a biodegradable tape according to one embodiment of the present invention. As shown in Figure 1, the biodegradable tape 1 may include a biodegradable backing film 11 and a biodegradable adhesive composition 13. The biodegradable backing film 11 can be a film made of any biodegradable material, such as, but not limited to, a polylactic acid (PLA) film, cellophane, or kraft paper. In addition, it can be a multilayer backing film made of one or a combination of biodegradable materials. In some embodiments, in order to improve the performance of the backing film 11, such as mechanical properties, the biodegradable backing film 11 can be structurally modified. For example, if a PLA film is used, the film can be biaxially stretched to obtain a biaxially oriented PLA film (BOPLA). In some embodiments, the adhesion of the biodegradable adhesive composition 13 to the biodegradable backing film 11 can also be enhanced by surface treatment (e.g., corona treatment).

[0029] Referring again to FIG. 1 , the biodegradable tape 1 further includes a biodegradable adhesive composition 13 coated on a biodegradable backing film 11. In the present invention, the biodegradable adhesive composition 13 includes an acrylic adhesive and a polyurethane dispersant. The ratios of the acrylic adhesive and the polyurethane dispersant, as well as the polyurethane dispersant relative to the biodegradable adhesive composition, are both appropriate. The dry weight of the polyurethane dispersant relative to the total wet weight of the biodegradable adhesive composition is at least 8%, for example, 8.0%, 8.1%, 8.5%, 10.0%, 12.5%, or any other ratio within this range. However, the polyurethane ratio should not be too high. In this embodiment, the dry weight of the polyurethane dispersant relative to the dry weight of the acrylic adhesive is preferably no more than 40.0%, for example, no more than 40.0%, no more than 30.0%, or no more than 20.0%. For example, it can be 39.2%, 29.4%, 19.2%, or any other ratio within this range. The adhesive of the present invention is an acrylic system, and the acrylic adhesive used is a water-based acrylic adhesive, including a water-based random copolymer, whose monomer units can be selected from one or more of acrylate, methacrylate, acrylic acid, methacrylic acid, acrylamide, and methacrylamide. The polyurethane dispersant can also be a water-based dispersant, among which anion-modified water-based polyurethane dispersants are preferred, but not limited to this.

[0030] In some embodiments, the biodegradable adhesive composition 13 in the biodegradable tape 1 may further include a tackifier. The tackifier may be selected from one or more of rosin, hydrogenated rosin resin, and terpene phenolic resin. Among them, emulsion-type tackifiers are preferred, but not limited to this. In some embodiments of the present invention, additives such as tackifiers are optionally added and are not essential. When added, it is preferred that the amount thereof does not exceed 12% of the total wet weight of the adhesive composition. In addition, the biodegradable adhesive composition 13 may further optionally include other additives, such as colorants or other additives, without affecting the adhesive properties and biodegradability of the biodegradable tape 1.

[0031] In the present invention, the biodegradable tape 1 has a Room Temperature Shear Force (RTS) of at least 24 hours as tested in accordance with the National Standard GBT4851-2014A of the People's Republic of China. In some embodiments, the RTS can be greater than 30 hours, 90 hours, or even 160 hours. The 180° Peel Adhesion (180°Peel Adhesion) tested in accordance with the National Standard GBT 2792-2014 of the People's Republic of China is at least greater than or equal to 2.5 N / cm. In some embodiments, the 180° Peel Adhesion of the biodegradable tape is greater than 3 N / cm, or even close to 8 N / cm. The Initial Tack (Initial Tack) tested in accordance with the National Standard GB / T4582-2002 of the People's Republic of China is at least greater than or equal to a No. 12 ball. In some embodiments, the Initial Tack of the biodegradable tape can reach a No. 14 ball, a No. 16 ball, or even a No. 17 ball. In addition, the biodegradable tape 1 has a Room Temperature Shear Force (RTS) of at least 24 hours as tested in accordance with the National Standard GB / T The composting rate of 19277.1 tested was at least 90% after 180 days. Therefore, the biodegradable tape 1 provided by the present invention has good adhesive retention, can be firmly adhered to the surface of the adherend, and has good initial adhesion. It not only provides good adhesion but also excellent biodegradability, taking into account the adhesive tape's adhesive and biodegradability. Therefore, the biodegradable tape of the present invention can be used in various applications requiring packaging, sealing, gluing, and covering. For example, it can be used as a sealing tape, but the application is not limited to this.

[0032] Please refer to Figure 2, which is a schematic diagram of the structure of a biodegradable tape according to another embodiment of the present invention. As shown in Figure 2, in addition to the biodegradable adhesive composition 13 coated on the biodegradable backing film 11, the biodegradable tape 1 may optionally include a release layer 15. The release layer 15 is disposed on the opposite side of the biodegradable backing film 11 from the biodegradable adhesive composition 13. In other words, the biodegradable adhesive composition 13 and the release layer 15 may be disposed on opposite sides of the biodegradable backing film 11. The choice of release layer 15 is not limited. For example, a long-chain alkyl or silicone release agent commonly used in adhesive tapes may be selected as the release layer, making the rolled biodegradable tape easier to unwind and convenient to use. It should also be understood that in certain embodiments, a release paper may also be used to facilitate unwinding. However, when using a release paper, the release paper is attached to the biodegradable adhesive composition.

[0033] The biodegradable tape 1 of the present invention also has the advantage of a simple manufacturing process. As shown in FIG3 , its manufacturing method includes the following steps: in step 1, providing a biodegradable backing film 11 and a biodegradable adhesive composition 13; in step 2, coating the biodegradable adhesive composition 13 on the biodegradable backing film; and in step 3, drying and dehydrating the biodegradable backing film coated with the biodegradable adhesive composition to obtain the biodegradable tape of the present invention. Since acrylic adhesives are commonly used in pressure-sensitive adhesives, they have the advantage of readily available raw materials compared to existing technologies. Furthermore, the adhesive coating method of the present invention is not limited to any method. Any method that can coat an adhesive onto a backing film can be used, including blade coating, roller coating, blade coating, rod coating, spin coating, spray coating, die coating, and gravure coating. The present invention preferably uses a coating thickness typically used to make adhesive tapes, such that the final dried biodegradable adhesive composition has a thickness of approximately 10-200 μm, preferably 10-100 μm, and more preferably 20-25 μm. Furthermore, since the biodegradable adhesive composition used in the present invention can be entirely aqueous, the adhesive composition can be dried using any method, including, but not limited to, oven heating. This simplifies processing and is environmentally friendly. Furthermore, compared to the water-based acrylic adhesives known in the prior art, this embodiment further improves its biodegradability, allowing acrylic adhesives to be used in the field of biodegradable tapes. If the biodegradable adhesive composition with excellent adhesive properties of the present invention is directly dried, a biodegradable adhesive can be obtained. Figure 4 is a flow chart for making a biodegradable tape according to another embodiment of the present invention. Compared to Figure 3, this embodiment adds the steps of providing a release layer and applying a release agent to form the release layer, wherein the release layer and the biodegradable adhesive composition are respectively applied to two opposite sides of a biodegradable backing film. In some embodiments, the release agent and the biodegradable adhesive composition can be applied simultaneously to two opposite sides of the biodegradable backing film in the same step. However, it should be understood that in other embodiments, they can also be applied to the biodegradable backing film in sequence, but the order of the two is not limited to produce a biodegradable tape with a release layer.

[0034] The following detailed description is intended to illustrate the present invention by way of example only and not by way of limitation.

[0035] Table 1 shows the raw materials and their sources used in the present invention.

[0036] Table 1 List of raw materials

[0037] The raw materials described in Table 1 were used to prepare each adhesive combination according to the proportions shown in Table 2 below.

[0038] The raw materials in Table 2 were mixed uniformly using a small blender. 20 g of the adhesive was then applied to a 400 mm x 800 mm biaxially oriented polylactic acid (BOPLA) film using a lab coater. The adhesive composition was dried at 100°C for 5 minutes to dehydrate the adhesive, producing tape samples.

[0039] Table 2 Ratio of each component in each adhesive composition

[0040] The following is a method for testing various properties of the adhesive tape according to the present invention. The test results of the properties of each group of adhesive tape samples are shown in Table 3.

[0041] Thickness of tape sample

[0042] The thickness of the adhesive tape is measured using the test method for adhesive tape thickness specified in the National Standard of the People's Republic of China, GB / T 7125-2014. The tape thickness is calculated by deducting the backing film from the measured thickness.

[0043] Room Temperature Shear Force

[0044] Adhesion retention was tested according to the National Standard of the People's Republic of China, GBT4851-2014A. A 12mm wide, 150mm long tape sample was evenly applied to a stainless steel plate using a roller. A weight was applied to the free end of the tape sample, keeping it vertical. The time it took for the tape sample to separate from the stainless steel test plate was recorded.

[0045] 180°Peel Adhesion

[0046] The peel strength of each tape sample was tested according to GBT 2792-2014, a national standard of the People's Republic of China. A 24mm wide, 300mm long tape sample was attached to a stainless steel plate. The plate was then secured to the grip of a tensile testing machine. Another grip held the free end of the tape sample at a 180° angle to the plate and pulled at a specified speed. The peel force required to separate the tape sample from the plate was measured.

[0047] Initial Tack

[0048] The initial adhesion of tape samples was tested according to the National Standard of the People's Republic of China, GB / T 4582-2002. Balls of varying sizes were placed on the adhesive surface of the tape on an inclined plate. The initial adhesion was evaluated based on the maximum ball size that could be held by the adhesive surface of a specified length.

[0049] Adhesion between adhesive and backing film (#2Bond)

[0050] After the tack test and the 180-degree peel strength test, the five groups of tape samples in Examples 1-5 were visually inspected to see whether the adhesive had detached from the backing film.

[0051] Degradation rate

[0052] This method uses the National Standard of the People's Republic of China GB / T 19277.1-2011, "Determination of the Ultimate Aerobic Biodegradability of Materials Under Controlled Composting Conditions Using the Trial Carbon Dioxide Method," to test the ultimate aerobic biodegradability and disintegration of each tape sample under simulated intense aerobic composting conditions. Each tape sample is mixed with an inoculum and introduced into a static composting container. Within this container, the mixture undergoes intense aerobic composting at a specified temperature, oxygen concentration, and humidity. The percentage of biodegradation is calculated using the formula specified in the standard.

[0053] Table 3 Properties of each group of tape samples

[0054] Generally speaking, whether the adhesive performance of the tape meets the use requirements is mainly determined by the three indicators of persistence, peel strength and initial adhesion. The higher the persistence of the tape, the better the ability of the tape to maintain adhesion after it completely adheres to the object. For example, the requirement for the persistence of packing tape is generally at least 24 hours. It can be seen from Examples 1-5 of the present invention that when the ratio of the polyurethane dispersant (dry weight) to the wet weight of the overall adhesive composition is increased to about or greater than 8%, the persistence of adhesion can reach the requirement of more than 24 hours, and even the persistence of the tape sample can reach at least 30 hours, showing that the persistence of the adhesiveness of the tape sample provided in this case is good; on the other hand, in Comparative Examples 1, 3, and 4, when the ratio of the polyurethane dispersant (dry weight) to the wet weight of the overall adhesive composition is less than 8%, the adhesive can maintain adhesion for a long time. The tape samples failed to meet the 24-hour adhesion requirement. When the adhesive composition lacked a polyurethane dispersant (Comparative Example 1), its cohesion was poor and the adhesion was poor. If the adhesive composition contained only a polyurethane dispersant but no acrylic adhesive, it did not provide the adhesive tape's adhesion (Comparative Example 2). In addition, increasing the proportion of polyurethane dispersant improved the tape's adhesion (Comparative Example 5). However, when the proportion of polyurethane dispersant was too high compared to the acrylic adhesive (Comparative Example 5), the initial adhesion of the tape (i.e., initial adhesion) was affected.

[0055] The initial adhesion of an adhesive tape represents its ability to adhere to an object within a short contact time. According to GB / T 4582-2002, the larger the ball number, the better the initial adhesion. Table 3 shows that the initial adhesion of Experimental Examples 1-5 all reached or exceeded ball number 12. This means that the tape samples of Examples 1-5 adhered quickly and firmly to the object when applied, a property beneficial for applications such as packaging and carton sealing. In contrast, in Comparative Example 5, when the ratio of polyurethane dispersant to acrylic adhesive (dry weight / dry weight) exceeded 40%, the tape sample failed to achieve good initial adhesion.

[0056] The 180-degree peel strength of adhesive tape reflects the material's bond strength. Referring again to Table 3, Experimental Examples 1-5 show that when the polyurethane dispersant (dry weight) ratio relative to the total adhesive composition wet weight is increased to 8% or more, and the polyurethane dispersant relative to the acrylic adhesive (dry weight / dry weight) is controlled below 40%, the 180-degree peel strength of each tape sample reaches at least 2.5 N / cm, demonstrating sufficient bond strength. While Comparative Example 1 exhibits good 180-degree peel strength, as previously mentioned, its adhesion is poor. In the absence of a polyurethane dispersant, the addition of a tackifier can slightly improve adhesion and 180-degree peel strength (Comparative Example 3 compared to Comparative Example 1). However, as previously mentioned, both Comparative Examples 3 and 1 still fail to meet the typical shear performance requirements for adhesive tape adhesion. Comparing Comparative Examples 3 and 4, the addition of a polyurethane dispersant may improve adhesion, but it also affects the 180-degree peel strength. This demonstrates that the amount of polyurethane dispersant added, as well as the appropriate ratio of polyurethane dispersant to acrylic adhesive, requires proper balance. This case demonstrated that when the polyurethane dispersant (dry weight) ratio relative to the wet weight of the adhesive composition is at least 8%, and the polyurethane dispersant to acrylic adhesive ratio (dry weight / dry weight) is controlled to no more than 40%, the tape samples exhibited excellent tack, peel strength, and initial tack. Furthermore, visual observation showed that the adhesives in Experiments 1-5 did not separate from the backing film after both the tack test and the 180-degree peel strength test, demonstrating good bonding between the adhesive and the tape backing.

[0057] Generally speaking, acrylic adhesives are cross-linked and therefore generally non-degradable. For example, in Comparative Example 1, degradation was tested using the GB / T 19277.1 method, and after 62 days, the degradation rate was only 6.77%. Polyurethane dispersants are generally used to enhance the cohesion of the adhesive. They may physically crosslink with the adhesive, strengthening the internal attractive forces that bind the adhesive together, resulting in better adhesion. However, when the internal attractive forces bind the adhesive together, they are not conducive to decomposition. In other words, substances that enhance cohesion may actually hinder the decomposition of the polymer. However, the polyurethane dispersant used in this invention not only possesses excellent biodegradability, but also surprisingly discovered that tapes made with an acrylic adhesive containing a small amount of this biodegradable polyurethane dispersant are also biodegradable (as shown in Comparative Example 4). Increasing the amount of polyurethane dispersant theoretically increases cohesion, hindering adhesive decomposition. However, when the polyurethane dispersant (dry weight) ratio relative to the wet weight of the adhesive composition is increased to above 8%, while simultaneously keeping the polyurethane dispersant to acrylic adhesive (dry weight / dry weight) ratio below 40%, as shown in Table 3, the degradation of the tape samples in Examples 1-5 of this invention all reached over 90% after 180 days, demonstrating both excellent cohesion and superior biodegradability. In other words, the resulting tapes are biodegradable and possess excellent adhesive properties. Furthermore, because tackifiers generally have a low molecular weight and do not cross-link with the adhesive, the addition of the polyurethane dispersant, and the ratio of polyurethane dispersant to acrylic adhesive, does not affect the adhesive properties and degradation rate of the tape sample. Degradation testing of the adhesive composition prepared according to the formulation in Example 3 revealed a 127-day degradation rate of 90.0%. This demonstrates that combining a water-based acrylic adhesive and a polyurethane dispersant in the ratio disclosed herein yields an adhesive composition with excellent adhesion and degradation properties.

[0058] Table 4 shows the adhesive properties and degradation rates of biodegradable tapes prepared by coating the adhesive composition of Example 2 on different biodegradable backing films.

[0059] Table 4 Properties of biodegradable tapes prepared by coating the adhesive composition of Example 2 on different biodegradable backing films

[0060] As shown in Table 4, the adhesive composition prepared using the formulation of Example 2 can maintain good tape adhesion performance and good degradation performance regardless of whether it is coated on a biaxially oriented polylactic acid film, kraft paper, or cellophane.

[0061] In summary, the present invention provides a biodegradable adhesive composition that is easy to prepare. This non-solvent adhesive composition is therefore relatively environmentally friendly and, compared to hot melt adhesives or other adhesives derived from biological components, offers the advantage of ease of preparation. When applied to a biodegradable backing, this adhesive composition can be made into various biodegradable tapes with excellent adhesive properties, meeting the required adhesive properties such as holding power, peel strength, and initial tack. This allows for use in various packaging, carton sealing, bonding, and laminating applications.

[0062] It will be apparent to those skilled in the art that various modifications may be made to the above-described embodiments without departing from the basic principles of the present invention. Furthermore, it will be apparent to those skilled in the art that various improvements and modifications may be made to the present invention without departing from the spirit and scope of the present invention.

Claims

1. A biodegradable tape comprising: A biodegradable adhesive composition comprising: An acrylic adhesive and a polyurethane dispersant, wherein the dry weight of the polyurethane dispersant is at least 8% relative to the wet weight of the biodegradable adhesive composition, and the dry weight of the polyurethane dispersant is no more than 40% relative to the dry weight of the acrylic adhesive; and Biodegradable backing film; The composting degradation rate of the biodegradable tape tested according to GB / T 19277.1 is at least greater than or equal to 90% in 180 days.

2. The biodegradable tape according to claim 1, wherein the biodegradable backing film is selected from a multi-layer backing of one or a combination of polylactic acid film, kraft paper and cellophane. 3 . The biodegradable adhesive tape according to claim 2 , wherein the biodegradable backing film is a biaxially stretched biodegradable backing film.

4. The biodegradable tape according to claim 1, wherein the acrylic adhesive comprises a water-based random copolymer, the monomer units of which are selected from one or more of acrylate, methacrylate, acrylic acid, methacrylic acid, acrylamide and methacrylamide.

5. The biodegradable tape according to claim 1, wherein the polyurethane dispersant is an aqueous dispersant. The biodegradable adhesive tape according to claim 5 , wherein the polyurethane dispersant is an anion-modified polyurethane dispersant. The biodegradable tape according to claim 1 , further comprising a tackifier.

8. The biodegradable tape according to claim 7, wherein the tackifier is selected from one or more of rosin resin, hydrogenated rosin resin and terpene phenolic resin. 9 . The biodegradable tape according to claim 1 , wherein the biodegradable tape has a lasting adhesiveness of at least greater than 24 hours as tested in accordance with GBT4851-2014A. 10 . The biodegradable tape according to claim 1 , wherein the 180 degree peel strength of the biodegradable tape tested according to GBT 2792-2014 is at least 2.5 N / cm.

11. The biodegradable tape according to claim 1, wherein the initial adhesion of the biodegradable tape measured in accordance with GB / T 4582-2002 is at least equal to or greater than that of a No. 12 ball. 12 . The biodegradable tape according to claim 1 , wherein the thickness of the biodegradable adhesive composition after drying is between 10 μm and 200 μm.

13. The biodegradable tape according to claim 1, further comprising a release layer.

14. A biodegradable adhesive composition comprising: Acrylic adhesives; and A polyurethane dispersant, wherein the dry weight of the polyurethane dispersant is at least 8% relative to the wet weight of the biodegradable adhesive composition, and the dry weight of the polyurethane dispersant is no more than 40% relative to the dry weight of the acrylic adhesive, wherein the composting degradation rate of the biodegradable adhesive composition tested according to GB / T 19277.1 is at least greater than or equal to 90% in 180 days.

15. The biodegradable adhesive composition according to claim 14, wherein the acrylic adhesive comprises a water-based random copolymer, and its monomer units are selected from one or more of acrylate, methacrylate, acrylic acid, methacrylic acid, acrylamide and methacrylamide.

16. The biodegradable adhesive composition according to claim 14, wherein the polyurethane dispersant is an aqueous dispersant. 17 . The biodegradable adhesive composition according to claim 16 , wherein the polyurethane dispersant is an anion-modified polyurethane dispersant.

18. The biodegradable adhesive composition according to claim 14, comprising a tackifier.

19. The biodegradable adhesive composition according to claim 18, wherein the tackifier is selected from one or more of rosin resin, hydrogenated rosin resin and terpene phenolic resin.

20. A method for making a biodegradable tape, comprising: Providing a biodegradable backing film and a biodegradable adhesive composition; The biodegradable adhesive composition is coated on the biodegradable backing film, wherein the biodegradable adhesive composition comprises an acrylic adhesive and a polyurethane dispersant, and the dry weight of the polyurethane dispersant is at least 8% relative to the wet weight of the biodegradable adhesive composition. The dry weight of the polyurethane dispersant is no more than 40% relative to the dry weight of the acrylic adhesive; and Drying and dehydrating the biodegradable backing film coated with the biodegradable adhesive composition to obtain the biodegradable tape; The composting degradation rate of the biodegradable tape tested according to GB / T 19277.1 is at least greater than or equal to 90% in 180 days.

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