TWI737378B - Biodegradable waterborne polyurethane pressure sensitive adhesive and products with biodegradable waterborne polyurethane pressure sensitive adhesive - Google Patents

Abstract

The present invention is a biodegradable waterborne polyurethane pressure sensitive adhesive and a product with biodegradable waterborne polyurethane pressure sensitive adhesive. The composition of the pressure sensitive adhesive includes: 100 parts by weight of biodegradable waterborne polyurethane resin, acetyl tributyl citrate 1 ~10 parts by weight, 0.2~1 parts by weight of glycerin, 10~25 parts by weight of starch and/or modified starch, 0.1~0.5 parts by weight of titanium dioxide, and 0.1~0.5 parts by weight of leveling aid; and the pressure sensitive adhesive is at 25°C The solid content is between 45-50% and the viscosity is between 4000-6400cPs. The product of the present invention is composed of a substrate, a pressure-sensitive adhesive layer and a release paper layer; the pressure-sensitive adhesive layer is arranged between the substrate and the release paper layer; the pressure-sensitive adhesive layer is formed of the aforementioned composition; the product selection of the present invention not only meets or exceeds Existing products have relative tack and peel strength requirements, and have excellent biodegradability, which can be widely used in products such as tapes, self-adhesive labels or random sticky notes.

Description

Biodegradable waterborne polyurethane pressure sensitive adhesive and products with biodegradable waterborne polyurethane pressure sensitive adhesive

The invention relates to the technical field of adhesives, in particular to a biodegradable waterborne polyurethane pressure sensitive adhesive and products with biodegradable waterborne polyurethane pressure sensitive adhesive.

Pressure-sensitive adhesive is a kind of adhesive that does not require additional solvent or heat, and only needs to be applied with light finger pressure to become a suitable adhesive with the adherend. It is mainly used to manufacture pressure sensitive tapes, pressure sensitive films and pressure sensitive adhesive labels. Because it is easy to use, it does not affect the surface of the adherend after it is torn, so it is very widely used.

The traditional pressure-sensitive adhesives of known technology are all materials that are not biodegradable or not easily biodegradable. Pressure-sensitive adhesives have a wide range of applications, such as single-sided tapes, double-sided tapes, labels or stickers for packaging and fixing. Although pressure-sensitive adhesive products have certain advantages and applications, because they are prone to pollution to the environment, the scope of application of the society's requirements for environmental protection will be gradually reduced, and will eventually withdraw from the market. Therefore, the appearance of pressure-sensitive adhesives and their products that can be completely biodegraded will surely produce great social benefits.

Examples of tapes include single-sided tape and double-sided tape. The single-sided tape includes a substrate and a release layer and an adhesive layer on both sides; a double-sided tape includes the main body of the adhesive layer on both sides of the substrate and a double-sided release Profiled film material, this double-sided release film material is also a release film material with a release agent on both sides, This double-sided release film is adhered to one of the two sides of the double-sided adhesive main body.

There has been a lot of research on biodegradable materials. In order to apply biodegradable materials widely and solve practical problems, it is necessary to continue to promote the use of biodegradable materials to avoid environmental pollution.

Among the most widely used tapes in the packaging field, if the tape is not effective due to insufficient viscosity of the pressure-sensitive adhesive, it is often discarded and cannot be biodegraded, resulting in a large amount of environmental pollution. In many existing tapes, there are still many pressure-sensitive adhesives or adhesives that cannot meet the required characteristics of the tape due to poor performance.

In view of this, the inventor of the present case aimed at the above shortcomings, after many research tests and prudential assessments, finally obtained a tape that can meet the requirements of relative tack and peel strength and has excellent biodegradability. It is a tape with excellent biodegradability. Practical invention.

The main purpose of the present invention is to provide a biodegradable waterborne polyurethane pressure-sensitive adhesive, which can overcome the problem that traditional pressure-sensitive adhesives cannot be decomposed by the environment in a short time even in an industrial composting environment. Within half a year, it can be completely decomposed into carbon dioxide and water by microorganisms in an industrial composting environment.

Another object of the present invention is to provide a biodegradable waterborne polyurethane pressure sensitive adhesive product. The product uses environmentally safe biodegradable waterborne polyurethane pressure sensitive adhesive, which not only meets or exceeds the relative viscosity and peeling properties of existing products It has high strength requirements, and has excellent biodegradability. It can be widely used in products such as tape, self-adhesive labels or random sticky notes.

Another object of the present invention is to provide a biodegradable aqueous polyurethane Ester pressure-sensitive adhesive product, which uses biodegradable water-based polyurethane pressure-sensitive adhesive as the adhesive layer, so that the product has the advantages of high tensile strength, good gloss and high elongation at break.

In order to achieve the above-mentioned object of the present invention, the technical means adopted are: to provide a biodegradable waterborne polyurethane pressure sensitive adhesive. The composition of the pressure sensitive adhesive includes: 100 parts by weight of biodegradable waterborne polyurethane resin, acetyl tributyl citrate 1~10 parts by weight of ester, 0.2~1 parts by weight of glycerin, 10~25 parts by weight of starch and/or modified starch, 0.1~0.5 parts by weight of titanium dioxide and 0.1~0.5 parts by weight of leveling aid; the pressure sensitive adhesive is at 25°C Under the conditions, the solid content is between 45-50%, and the viscosity is between 4000-6400cPs.

Used in the above embodiments of the present invention, the composition of the biodegradable waterborne polyurethane resin includes: polyester diol and/or polyether diol, hydrophilic group, isocyanate, chain extender and multi-crosslinking agent.

The polyester diol and/or polyether diol is 55-75% based on the total weight of the composition, and the polyester diol and/or polyether diol is selected from polybutylene glycol adipic acid, polyethylene glycol One of glycol adipate, polycaprolactone, polylactic acid, butanediol-adipate copolymer, hexylene glycol-adipate copolymer, ethylene-adipate copolymer, and polyethylene glycol or Multiple; Preferably, the polyester diol and/or polyether diol is a butanediol-adipic acid copolymer.

The hydrophilic group is 3-10% based on the total weight of the composition. The hydrophilic group includes 2,2-dimethylolpropionic acid (DMPA) and 2,2-dimethylolbutyric acid (DMBA). Among them, DMBA has high tensile strength (7.6~9.4MPa), good gloss (78~85GU), high elongation at break (464~495%), easily soluble in polyols, low melting point (melting point 108~115℃) and synthesis The advantage of short reaction time (about 50-60 minutes); DMBA does not need to consume solvents in the synthesis process, so it not only shortens the reaction time, reduces energy consumption, but also saves energy. However, DMPA has a high melting point (180~185℃) and a long synthesis reaction time (about 150~180 minutes); preferably, the hydrophilic group is 2,2-dimethylolbutanoic acid (DMBA).

The isocyanate is 10-25% based on the total weight of the composition, and the isocyanate is selected from the group consisting of 1,6-ethylene diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, dimethyl diaminobenzene diisocyanate, cyclohexane diisocyanate One or more of isocyanate, methyl diisocyanate cyclohexane and isophorone isocyanate; preferably, the isocyanate is isophorone isocyanate.

The chain extender is 1 to 5% based on the total weight of the composition, and the chain extender is selected from the group consisting of ethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 1 ,4-Cyclohexanedimethanol, hydroxyethylethylenediamine, diethylenetriamine, ethylenediamine and neopentyl glycol one or more; the aforementioned 1,4-butanediol has good flexibility and is more expensive Low, fast reaction and no yellowing, therefore, preferably, the chain extender is 1,4-butanediol.

The multi-element cross-linking agent is based on the total weight of the composition 1 to 5%, and the multi-element cross-linking agent is selected from one or more of 1,1,1-trimethylolpropane, glycerin and castor oil; the aforementioned 1,1, 1-Trimethylolpropane has good crystallization resistance, low price, rapid reaction and no yellowing. Therefore, preferably, the multi-component crosslinking agent is 1,1,1-trimethylolpropane.

In the above embodiments of the present invention, the tributyl acetyl citrate is used as a plasticizer in the present invention, preferably, it accounts for 1-10 parts by weight, more preferably 2-5 parts by weight.

Used in the above embodiments of the present invention, the starch and/or modified starch is used in the present invention as a thickener; wherein, the starch is selected from one or more of corn starch, potato starch and tapioca starch. The modified starch is selected from one or more of acetic acid modified starch, monopropyl modified starch and acetic acid monopropyl modified starch. Preferably, the modified starch is an acetic acid modified starch and/or a monopropyl modified starch, and the acetic acid modified starch and/or a monopropyl modified starch accounts for 15 parts by weight.

In an embodiment of the present invention described above, the leveling aid is used to improve the surface of the colloid Tension, so that it can be used on the surface of various substrates with different surface tensions. Preferably, the leveling aid is a polyether modifier (organosilicon), which is selected from the products 350W, 487U, 488U of UniqChem, Germany, or BKY-3400, BKY-3450, and BKY-3451, products of BKY, Germany. More preferably, the leveling aid is BKY-3451, a product of German BKY Company, accounting for 0.2 parts by weight.

In one embodiment of the present invention, the present invention also provides a biodegradable water-based polyurethane pressure-sensitive adhesive product, which includes: a substrate, a pressure-sensitive adhesive layer and a release paper layer; wherein the pressure-sensitive adhesive layer is provided with Between the substrate and the release paper layer, the pressure sensitive adhesive layer is made of the aforementioned biodegradable waterborne polyurethane pressure sensitive adhesive.

As used in the above embodiments of the present invention, the substrate is a biodegradable film, paper, cloth or film. The biodegradable film is a polybutylene adipate terephthalate (PBAT) film.

Used in the above embodiment of the present invention, the release paper layer is a biodegradable release paper containing silicone oil.

Used in the above embodiments of the present invention, the product is a single-sided tape or a label sticker.

In one embodiment of the present invention, the present invention provides a biodegradable water-based polyurethane pressure-sensitive adhesive product. The product includes: a substrate, a first pressure-sensitive adhesive layer, a second pressure-sensitive adhesive layer, and a release Type paper layer; wherein, the substrate is provided with a first pressure-sensitive adhesive layer on one side, and the other side of the substrate is provided with a second pressure-sensitive adhesive layer, and the release paper layer is provided on the first pressure-sensitive adhesive layer or the second pressure-sensitive adhesive layer Above the layer, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are made of the aforementioned biodegradable water-based polyurethane pressure-sensitive adhesive.

Used in the above embodiments of the present invention, the substrate is a biodegradable film, and the biodegradable film The decomposable film is polybutylene adipate terephthalate (PBAT) film.

In an embodiment of the present invention, wherein the release paper layer is a biodegradable release paper containing silicone oil.

In an embodiment of the present invention, wherein the product is a double-sided tape.

Compared with the prior art, the present invention has the following beneficial effects: (1) A biodegradable waterborne polyurethane pressure sensitive adhesive and a product with biodegradable waterborne polyurethane pressure sensitive adhesive of the present invention, wherein the pressure sensitive adhesive is solidified at 25°C The content is between 45-50% and the viscosity is between 4000-6400cPs. The pressure-sensitive adhesive layer of this product has the advantages of high tensile strength, good gloss and high elongation at break. (2) A biodegradable waterborne polyurethane pressure sensitive adhesive and products with biodegradable waterborne polyurethane pressure sensitive adhesive of the present invention, wherein the pressure sensitive adhesive and its products have excellent biodegradability, no pollution to the environment and also solve environmental plastics The problem of waste. (3) A biodegradable waterborne polyurethane pressure-sensitive adhesive of the present invention. Because the colloid is soluble in water, its colloidal solvent is different from oil-based glue. It uses water that does not pollute the environment as a solvent, and uses titanium dioxide and glycerin to accelerate polymer disintegration. Decomposition, and then promote the digestion and absorption of microorganisms, and finally release back to nature in the form of carbon dioxide and water. (4) A biodegradable single-sided tape and double-sided tape product produced by the present invention has good tensile strength and tear resistance, and has excellent biodegradability, and it does not pollute the environment. Solve the problem of environmental plastic waste.

1: Substrate

2: Pressure sensitive adhesive layer

3: Release paper layer

21: The first pressure-sensitive adhesive layer

22: The second pressure sensitive adhesive layer

1 is a schematic cross-sectional view of a first embodiment of a biodegradable water-based polyurethane pressure-sensitive adhesive layer product, which is used to illustrate the cross-sectional structure of a single-sided tape or label sticker.

Figure 2 is a schematic cross-sectional view of a second embodiment of a biodegradable water-based polyurethane pressure-sensitive adhesive product The figure is used to illustrate the cross-sectional structure of the double-sided tape.

The following specific examples illustrate the implementation of the present invention. Those familiar with the art can easily understand the other advantages and effects of the present invention from the contents disclosed in this specification.

The present invention is a biodegradable waterborne polyurethane pressure sensitive adhesive. The composition of the pressure sensitive adhesive includes: 100 parts by weight of biodegradable waterborne polyurethane resin, 1 to 10 parts by weight of acetyl tributyl citrate, 0.2 to 1 parts by weight of glycerin, 10-25 parts by weight of starch and/or modified starch, 0.1-0.5 parts by weight of titanium dioxide, and 0.1-0.5 parts by weight of leveling aid; the pressure-sensitive adhesive has a solid content of 45-50% at 25°C, and its viscosity Between 4000~6400cPs.

The composition of the aforementioned biodegradable waterborne polyurethane resin includes: a hydrophilic group of 3-10% based on the total weight of the composition, selected from 2,2-dimethylolbutyric acid (DMBA); one based on the total weight of the composition 10-25 % Isocyanate, selected from isophorone isocyandiate (IPDI); a polyester diol and/or polyether diol based on the total weight of 55-75%, selected from butanediol-hexane Diacid copolymer (PBA); a chain extender of 1 to 5% based on the total weight of the composition, selected from 1,4-butanediol (1,4-BG); and a 1-5% based on the total weight of the composition The multiple crosslinking agent is selected from 1,1,1-trimethylolpropane (TMP).

Example 1: Please refer to Figure 1, a biodegradable waterborne polyurethane pressure-sensitive adhesive product. The product is a single-sided adhesive tape, comprising: a substrate 1, a pressure-sensitive adhesive layer 2 and a release paper layer 3; The pressure sensitive adhesive layer 2 is provided on the upper surface of the substrate 1, and the release paper layer 3 is provided on the upper surface of the pressure sensitive adhesive layer 2.

The above-mentioned substrate 1 is polybutylene adipate terephthalate (PBAT) biologically separable Decomposable film; the release paper layer 3 is a biodegradable release paper containing silicone oil.

The above-mentioned pressure sensitive adhesive layer 2 is a coating of biodegradable waterborne polyurethane pressure sensitive adhesive. The coating is a pressure sensitive adhesive layer 2 formed by drying at a temperature of 80~110°C. The thickness of the pressure sensitive adhesive layer 2 is 15um. . The biodegradable waterborne polyurethane pressure sensitive adhesive is formulated with the following composition to obtain the characteristics of a solid content of 45.6% at 25°C and a viscosity of 6489 cPs.

The composition of the above biodegradable waterborne polyurethane pressure sensitive adhesive includes: 100 parts by weight of biodegradable waterborne polyurethane resin (the composition includes: butanediol-adipate copolymer (PBA) 70%, 2,2-dimethylol Butyric acid (DMBA) 5.5%, isophorone isocyandiate (IPDI) 19%, 1,4-butanediol (1,4-BG) 3.5% and 1,1,1-trimethylol Propane (TMP) 2%); 5 parts by weight of acetyl tributyl citrate; 1 part by weight of glycerin; 15 parts by weight of acetic acid modified starch, selected from the product of Pinyuan Industrial Co., Ltd. TM-180; 0.3 parts by weight of titanium dioxide; And 0.2 parts by weight of leveling aid, selected from the product 3451 of BYK, Germany.

Example 2: Please refer to Figure 1, the biodegradable waterborne polyurethane pressure sensitive adhesive product, which is a single-sided adhesive tape, including: a substrate 1, a pressure sensitive adhesive layer 2 and a release paper layer 3 Wherein the pressure-sensitive adhesive layer 2 is provided on the upper surface of the substrate 1, and the release paper layer 3 is provided on the upper surface of the pressure-sensitive adhesive layer 2.

The aforementioned substrate 1 is a polybutylene adipate terephthalate (PBAT) biodegradable film; the release paper layer 3 is a biodegradable release paper containing silicone oil.

The above-mentioned pressure sensitive adhesive layer 2 is a coating of biodegradable waterborne polyurethane pressure sensitive adhesive. The coating is a pressure sensitive adhesive layer 2 formed by drying at 80~110°C. The thickness of the pressure sensitive adhesive layer 2 is 15um. The biodegradable waterborne polyurethane pressure sensitive adhesive is formulated with the following composition to obtain the characteristics of a solid content of 47.2% at 25°C and a viscosity of 5832 cPs.

The composition of the above biodegradable waterborne polyurethane pressure sensitive adhesive includes: 100 parts by weight of biodegradable waterborne polyurethane resin (composition includes: PBA, DMBA, IPDI, 1,4-BG, TMP); tributyl acetyl citrate 2 parts by weight; 1 part by weight of glycerin; 15 parts by weight of propyl modified starch, selected from Pinyuan Industrial Co., Ltd. product CB-106; 0.3 parts by weight of titanium dioxide; and 0.2 parts by weight of leveling aid, selected from BYK, Germany Product 3451.

Table 1 shows the relative viscosity test comparison of the pressure-sensitive adhesives of the single-sided tape products of Example 1 and Example 2 and the control group (general pressure-sensitive adhesive). Example 1 and Example 2 used different modified starches and different weight ratios of acetyl tributyl citrate to make a 15um adhesive layer (in the same polybutylene adipate terephthalate) (PBAT) The biodegradable film is coated with a glue layer with a thickness of 15um).

The solid content of the pressure-sensitive adhesive of Example 1 at 25° C. is 45.6% and the viscosity is 6489 cPs.

The solid content of the pressure-sensitive adhesive of Example 2 at 25°C is 47.2%, and the viscosity is 5832 cPs.

The initial force in Table 1 (also known as the initial adhesion, which is the "momentary" adhesive force that separates immediately upon contact) is tested in accordance with ASTM D-3121; retention force is tested in accordance with ASTM D-3654; peel strength is tested in accordance with ASTM D- 3330 for testing.

According to Table 1, it can be clearly seen that the initial strength of Example 1 and Example 2 is reduced; the retention and peel strength are better than those of the general pressure-sensitive adhesive tape of the control group.

Embodiment 3: Please refer to Figure 1, the biodegradable waterborne polyurethane pressure sensitive adhesive product, the product is a label sticker (trademark sticker), including: a substrate 1, a pressure sensitive adhesive layer 2 and a release Type paper layer 3; wherein the pressure sensitive adhesive layer 2 is provided on the upper surface of the substrate 1, and the release paper layer 3 is provided on the upper surface of the pressure sensitive adhesive layer 2.

The aforementioned substrate 1 is a biodegradable copper paper; the aforementioned release paper layer 3 is a biodegradable release paper containing silicone oil.

The above-mentioned pressure sensitive adhesive layer 2 is a coating of biodegradable waterborne polyurethane pressure sensitive adhesive, and the coating is a pressure sensitive adhesive layer 2 formed by drying at 80-110° C., and the thickness of the pressure sensitive adhesive layer 2 is 25 um. The biodegradable waterborne polyurethane pressure sensitive adhesive is formulated with the following composition to obtain the characteristics of a solid content of 45.6% at 25°C and a viscosity of 6489 cPs.

The composition of the above biodegradable waterborne polyurethane pressure sensitive adhesive includes: 100 parts by weight of biodegradable waterborne polyurethane resin (composition includes: PBA, DMBA, IPDI, 1,4-BG, TMP); tributyl acetyl citrate 5 parts by weight; 1 part by weight of glycerin; 15 parts by weight of acetic acid modified starch, selected from the product TM-180 of Pinyuan Industrial Co., Ltd.; 0.3 parts by weight of titanium dioxide; and 0.2 parts by weight of leveling aids, selected from the product 3451 of BYK, Germany.

Embodiment 4: Please refer to Figure 1, the biodegradable waterborne polyurethane pressure sensitive adhesive product, the product is a label sticker (trademark sticker), including: a substrate 1, a pressure sensitive adhesive layer 2 and a release Type paper layer 3; wherein the pressure sensitive adhesive layer 2 is provided on the upper surface of the substrate 1, and the release paper layer 3 is provided on the upper surface of the pressure sensitive adhesive layer 2.

The substrate 1 is biodegradable copper paper; the release paper layer 3 is biodegradable release paper containing silicone oil.

The above-mentioned pressure sensitive adhesive layer 2 is a coating of biodegradable waterborne polyurethane pressure sensitive adhesive. The coating is a pressure sensitive adhesive layer 2 formed by drying at a temperature of 80 to 110°C. The thickness of the pressure sensitive adhesive layer 2 is 25 μm. . The biodegradable waterborne polyurethane pressure sensitive adhesive is formulated with the following composition to obtain the characteristics of a solid content of 47.2% at 25°C and a viscosity of 5832 cPs.

The composition of the above biodegradable waterborne polyurethane pressure sensitive adhesive includes: 100 parts by weight of biodegradable waterborne polyurethane resin (composition includes: PBA, DMBA, IPDI, 1,4-BG, TMP); tributyl acetyl citrate 2 parts by weight; 1 part by weight of glycerin; 15 parts by weight of propyl modified starch, selected from Pinyuan Industrial Co., Ltd. product CB-106; 0.3 parts by weight of titanium dioxide; and 0.2 parts by weight of leveling aid, selected from BYK, Germany Product 3451.

Table 2 shows the relative viscosity test comparison of the pressure-sensitive adhesives of the trademark sticker products of Example 3 and Example 4 and the control group (general pressure-sensitive adhesive). Example 3 and Example 4 use different changes The adhesive layer with a thickness of 25um is made under the different weight ratios of starch and tributyl acetyl citrate (coating thickness on the same polybutylene adipate terephthalate (PBAT) biodegradable film). 25μm glue layer).

The solid content of the pressure-sensitive adhesive of Example 3 at 25° C. is 45.6% and the viscosity is 6489 cPs.

The solid content of the pressure-sensitive adhesive of Example 4 at 25°C is 47.2%, and the viscosity is 5832 cPs.

The initial force in Table 2 (also known as the initial adhesion, which is the "instant" adhesive force that separates immediately upon contact) is tested in accordance with ASTM D-3121; the peel strength is tested in accordance with ASTM D-3330.

According to Table 2, it can be clearly seen that the initial strength of Example 3 and Example 4 is decreased, and the peel strength is better than that of the normal trademark sticker of the control group.

Embodiment 5: Please refer to Figure 2, a product with a biodegradable waterborne polyurethane pressure sensitive adhesive, the product is a double-sided tape, including: a substrate 1, a first pressure sensitive adhesive layer 21, a second sensor Pressure-sensitive adhesive 22 and a release paper layer 3; wherein the first pressure-sensitive adhesive layer 21 is provided on the upper surface of the substrate 1, the second pressure-sensitive adhesive layer 22 is provided on the lower surface of the substrate 1, and the release paper layer 3 can be provided on On the surface of the first pressure-sensitive adhesive layer 21 or the second pressure-sensitive adhesive layer 22, in this embodiment, it is provided on the upper surface of the first pressure-sensitive adhesive layer 21.

The aforementioned substrate 1 is a biodegradable art paper, and the release paper layer 3 is a biodegradable release paper containing silicone oil.

The above-mentioned first pressure-sensitive adhesive layer 21 and second pressure-sensitive adhesive layer 22 are biodegradable water The coating of polyurethane pressure sensitive adhesive, which is formed by drying at 80~110℃. The first pressure-sensitive adhesive layer 21 and the second pressure-sensitive adhesive layer are made of the aforementioned biodegradable water-based polyurethane pressure-sensitive adhesive. The composition of the pressure-sensitive adhesive includes: 100 parts by weight of the biodegradable water-based polyurethane resin (composition Including: PBA, DMBA, IPDI, 1,4-BG, TMP); 1-10 parts by weight of tributyl acetyl citrate; 0.2-1 parts by weight of glycerin; 10-25 parts by weight of starch and/or modified starch; 0.1 to 0.5 parts by weight of titanium dioxide; and 0.1 to 0.5 parts by weight of leveling aids.

From the above examples 1 to 4, it can be seen that the product of the present invention has excellent characteristics in retention and peel strength. Therefore, the product can provide better tensile strength and tear resistance; in addition, the product can be used in a suitable environment (Temperature 60℃, relative humidity Rh58%), can be decomposed by microorganisms in the soil, can provide products with excellent biodegradability, and achieve the purpose of product biodegradability; Furthermore, Example 5 can be obtained from Examples 1 to 4 Intended purpose.

In summary, it is only a description of the preferred five implementations of the present invention, and does not limit the scope of the present invention. Without departing from the design spirit of the present invention, those of ordinary skill in the art have made various contributions to the technical solutions of the present invention. Deformation and improvement shall fall within the protection scope of the patent application of the present invention.

1: Substrate

2: Pressure sensitive adhesive layer

3: Release paper layer

Claims (11)

A biodegradable waterborne polyurethane pressure sensitive adhesive, the composition of which comprises: 100 parts by weight of biodegradable waterborne polyurethane resin, 1 to 10 parts by weight of acetyl tributyl citrate, 0.2 to 1 parts by weight of glycerin, starch and / Or 10-25 parts by weight of modified starch, 0.1-0.5 parts by weight of titanium dioxide and 0.1-0.5 parts by weight of leveling aid; and the pressure-sensitive adhesive has a solid content of 45-50% at 25°C, and a viscosity between 4000~6400cPs. The biodegradable waterborne polyurethane pressure sensitive adhesive according to claim 1, wherein the composition of the biodegradable waterborne polyurethane resin includes: a polyester diol and/or polyether diol based on the total weight of the composition at 55-75% , The polyester diol and/or polyether diol is selected from polybutylene glycol adipic acid, polyethylene glycol adipic acid, polycaprolactone, polylactic acid, butylene glycol-adipate copolymer , Hexanediol-adipic acid copolymer, ethylene-adipic acid copolymer and polyethylene glycol one or more; a hydrophilic group based on the total weight of 3~10%, the hydrophilic group is 2, 2-Dimethylolbutyric acid (DMBA); an isocyanate of 10-25% based on the total weight of the composition, the isocyanate is selected from 1,6-ethylene diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, dimethyl One or more of diaminobenzene diisocyanate, cyclohexane diisocyanate, methyl diisocyanate, cyclohexane, and isophorone isocyanate; a chain extender of 1-5% based on the total weight of the composition , The chain extender is selected from the group consisting of ethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, hydroxyethyl ethylene two One or more of amine, diethylenetriamine, ethylenediamine, and neopentyl glycol; and a multi-element cross-linking agent of 1 to 5% based on the total weight of the composition, the multi-element cross-linking agent selected from 1,1,1- Trimethylol One or more of propane, glycerin and castor oil. The biodegradable waterborne polyurethane pressure-sensitive adhesive according to claim 1, wherein the starch is selected from one or more of corn starch, potato starch and tapioca starch. The biodegradable waterborne polyurethane pressure-sensitive adhesive according to claim 1, wherein the modified starch is selected from one or more of acetic acid modified starch, propyl modified starch, and acetic acid modified starch. For example, the biodegradable waterborne polyurethane pressure sensitive adhesive of claim 1, wherein the leveling aid is a polyether-modified organosilicon, selected from the products of UniqChem, Germany 350W, 487U, and 488U or the products of BKY, Germany BKY-3400, BKY-3450, BKY-3451. A pressure-sensitive adhesive product with biodegradable waterborne polyurethane. The product includes: a substrate, a pressure-sensitive adhesive layer and a release paper layer; wherein the pressure-sensitive adhesive layer is provided on the upper surface of the substrate, and the release paper layer is provided on the surface of the substrate. On the upper surface of the pressure-sensitive adhesive layer; the pressure-sensitive adhesive layer is made of the biodegradable water-based polyurethane pressure-sensitive adhesive described in any one of Claims 1 to 5. The biodegradable waterborne polyurethane pressure-sensitive adhesive product of claim 6, wherein the substrate is polybutylene adipate terephthalate (PBAT) film, paper, cloth or film. For example, the biodegradable waterborne polyurethane pressure-sensitive adhesive product of claim 6, wherein the product is a single-sided tape or a label sticker. A pressure-sensitive adhesive product with biodegradable water-based polyurethane, the product comprising: a substrate, a first pressure-sensitive adhesive layer, a second pressure-sensitive adhesive layer and a release paper layer; wherein, one side of the substrate is provided with a first A pressure-sensitive adhesive layer, the other side of the substrate is provided with a second pressure-sensitive adhesive layer; the release paper layer is provided on the first pressure-sensitive adhesive layer or the second pressure-sensitive adhesive layer; the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer The pressure sensitive adhesive layer is made of the biodegradable waterborne polyurethane pressure sensitive adhesive described in any one of Claims 1 to 5. The biodegradable waterborne polyurethane pressure-sensitive adhesive layer product of claim 9, wherein the substrate is a polybutylene adipate terephthalate (PBAT) film. The biodegradable waterborne polyurethane pressure-sensitive adhesive layer product of claim 9, wherein the product is a double-sided tape.

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