Preparation method of biodegradable hot melt adhesive

Abstract

The preparation method of the biodegradable hot melt adhesive comprises the following steps: mixing a plurality of biodegradable materials and carrying out chemical cross-linking reaction to form a copolymer; carrying out hydrolysis reaction on the copolymer to form a hydrolyzed copolymer; and mixing and heating the hydrolyzed copolymer, the first additive and the second additive to form the biodegradable hot melt adhesive. The plurality of biodegradable materials comprise at least two of polylactic acid, polycaprolactone, poly (butylene succinate), polyhydroxyalkanoate and polyethylene glycol. The first additive comprises at least one of tackifying resin and a plasticizer, and the second additive comprises at least one of an antioxidant and an anti-hydrolysis agent. The preparation method of the biodegradable hot melt adhesive has the advantages of simple production process and low cost, and the prepared biodegradable hot melt adhesive has excellent performance.

Description

Technical Field

[0001] The invention relates to a method for preparing hot melt adhesive, in particular to a method for preparing biodegradable hot melt adhesive. Background Art

[0002] As an important adhesive, hot melt adhesive is widely used in various products, such as packaging, assembly, electronics and other fields. Traditional hot melt adhesives are mainly made of petrochemical raw materials. Since products made from traditional petrochemical raw materials are usually not easy to decompose and cause environmental pollution, with the growing awareness of environmental protection in recent years, relevant industries have also launched hot melt adhesives made of biodegradable materials. Common biodegradable materials include materials such as polylactic acid (PLA) and polyhydroxyalkanoates (PHAs) made from bio-based materials such as starch, cellulose and vegetable oil, as well as polycaprolactone (PCL), polybutylene succinate (PBS) and polyethylene glycol (PEG) made from petrochemical-based materials.

[0003] However, conventional hot melt adhesives made of biodegradable materials have poor performance. In addition, the existing production process of hot melt adhesives made of biodegradable materials is very complicated. Therefore, how to develop a method for making biodegradable hot melt adhesives with a simple production process and produce biodegradable hot melt adhesives with excellent performance has become an important topic in the current technological development. Summary of the invention

[0004] The invention provides a method for preparing a biodegradable hot melt adhesive, which can produce the biodegradable hot melt adhesive with excellent performance and has the advantage of a simple production process.

[0005] To achieve one or part or all of the above purposes or other purposes, one embodiment of the present invention provides a method for making a biodegradable hot melt adhesive, comprising: mixing a plurality of biodegradable materials and subjecting the mixture to a chemical crosslinking reaction to form a copolymer; subjecting the copolymer to a hydrolysis reaction to form a hydrolyzed copolymer; and mixing and heating the hydrolyzed copolymer, a first additive, and a second additive to form a biodegradable hot melt adhesive. The plurality of biodegradable materials include at least two of polylactic acid, polycaprolactone, polybutylene succinate, polyhydroxyalkanoate, and polyethylene glycol. The first additive includes at least one of a tackifying resin and a plasticizer, and the second additive includes at least one of an antioxidant and an anti-hydrolysis agent.

[0006] In one embodiment of the present invention, the step of performing a chemical cross-linking reaction includes: mixing a cross-linking agent with a plurality of biodegradable materials, and then performing a chemical cross-linking reaction for 1 to 2 hours at a temperature between 160 degrees Celsius and 190 degrees Celsius and a pressure between 1 MPa and 1.5 MPa.

[0007] In one embodiment of the present invention, the cross-linking agent comprises at least one of di-tert-butyl peroxyisopropylbenzene, diisopropyl peroxide, stannous isooctanoate, methylene diphenyl diisocyanate, epoxy soybean oil, maleated soybean oil and epoxy soybean oil acrylate, and the cross-linking agent accounts for 0.05wt% to 3.0wt% of the total weight of the multiple biodegradable materials and the cross-linking agent.

[0008] In one embodiment of the present invention, the molecular weight of the copolymer is between 500 kDa and 1,500 kDa.

[0009] In one embodiment of the present invention, the step of hydrolyzing the copolymer comprises: mixing a hydrolysis agent with the copolymer, and performing a hydrolysis reaction for 1 hour to 1.5 hours at a temperature between 130 degrees Celsius and 160 degrees Celsius and a pressure between 1 MPa and 1.5 MPa.

[0010] In one embodiment of the present invention, the hydrolysis reagent comprises at least one of sodium hydroxide and potassium hydroxide, and the hydrolysis reagent accounts for 0.05 wt % to 3.0 wt % of the total weight of the copolymer and the hydrolysis reagent.

[0011] In one embodiment of the present invention, the molecular weight of the hydrolyzed copolymer is between 50 kDa and 300 kDa.

[0012] In one embodiment of the present invention, the step of mixing and heating the hydrolyzed copolymer, the first additive and the second additive comprises: mixing and stirring the hydrolyzed copolymer, the first additive and the second additive at a temperature between 130 degrees Celsius and 160 degrees Celsius and a pressure between 1 MPa and 1.5 MPa for 1 hour to 2 hours.

[0013] In one embodiment of the present invention, the first additive accounts for 5wt% to 50wt% of the total weight of the hydrolyzed copolymer, the first additive and the second additive, and the second additive accounts for 0.05wt% to 3.0wt% of the total weight of the hydrolyzed copolymer, the first additive and the second additive.

[0014] In one embodiment of the present invention, the above-mentioned tackifying resin includes at least one of rosin resin and terpene resin. The plasticizer includes at least one of triethyl citrate, acetylated triethyl citrate, acetylated tributyl citrate, tributyrin, castor oil and polyethylene glycol. The anti-hydrolysis agent includes at least one of epoxy compounds and carbodiimide anti-hydrolysis agents. The antioxidant includes at least one of a hindered phenol antioxidant and a phosphite antioxidant.

[0015] The present invention helps to improve the stability of the biodegradable hot melt adhesive by mixing a plurality of biodegradable materials and performing a chemical cross-linking reaction, and helps to make a biodegradable hot melt adhesive with good performance by regulating the molecular weight of the hydrolyzed copolymer through a hydrolysis reaction. In addition, the biodegradable hot melt adhesive preparation method provided by the present invention has the advantage of a simple production process.

[0016] In order to make the above and other purposes, features and advantages of the present invention more clearly understood, embodiments are given below with reference to the accompanying drawings for detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The figure is a schematic flow chart of a method for producing a biodegradable hot melt adhesive according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] Figure 1 This is a flow chart of a method for making a biodegradable hot melt adhesive according to an embodiment of the present invention. Figure 1 , a method for making a biodegradable hot melt adhesive according to an embodiment of the present invention comprises steps S100 to S300, wherein: step S100 is to mix a plurality of biodegradable materials and perform a chemical cross-linking reaction to form a copolymer. The aforementioned plurality of biodegradable materials include at least two of polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS), polyhydroxyalkanoates (PHAs) and polyethylene glycol (PEG). Step S200 is to perform a hydrolysis reaction on the copolymer to form a hydrolyzed copolymer. Step S300 is to mix and heat the hydrolyzed copolymer, the first additive and the second additive to form a biodegradable hot melt adhesive, wherein the first additive comprises at least one of a tackifying resin and a plasticizer, and the second additive comprises at least one of an antioxidant and an anti-hydrolysis agent. The method for making a biodegradable hot melt adhesive according to an embodiment of the present invention can avoid the problem of environmental pollution caused by difficulty in decomposition because biodegradable materials are used.

[0019] The method for making a biodegradable hot melt adhesive according to an embodiment of the present invention uses a variety of biodegradable materials, and can produce a hot melt adhesive with good performance, such as excellent mechanical properties and surface wettability. Specifically, different biodegradable materials have different properties. For example, from the perspective of mechanical properties, polylactic acid is relatively hard and brittle, while polycaprolactone and polyethylene glycol are relatively soft and tough. Therefore, the biodegradable hot melt adhesive according to an embodiment of the present invention uses a variety of biodegradable materials, so that the biodegradable hot melt adhesive can have the advantages of each material.

[0020] In addition, the method for making a biodegradable hot melt adhesive according to an embodiment of the present invention includes subjecting a plurality of biodegradable materials to a chemical cross-linking reaction to form a copolymer, which can allow different biodegradable materials to undergo a chemical cross-linking reaction, or can be understood as grafting or modifying the biodegradable materials. Therefore, compared to simply physically blending a plurality of biodegradable materials, subjecting a plurality of biodegradable materials to a chemical cross-linking reaction can enhance the compatibility of the mixed biodegradable materials, thereby improving the thermal stability of the biodegradable hot melt adhesive, thereby preventing the biodegradable hot melt adhesive from undergoing phase separation after being heated, especially when the hot melt adhesive is used continuously in large quantities, the hot melt adhesive is heated in a sol tank, or the hot melt adhesive is heated for a long time. Therefore, the method for making a biodegradable hot melt adhesive according to an embodiment of the present invention is conducive to the large-scale application of hot melt adhesives.

[0021] In one embodiment of the present invention, a method for making a biodegradable hot melt adhesive mixes a plurality of biodegradable materials and performs a sufficient chemical cross-linking reaction to ensure that the formed copolymer has an appropriate uniformity and an appropriate molecular weight. In one embodiment of the present invention, the molecular weight of the copolymer is, for example, between 500 kDa and 1,500 kDa, preferably between 800 kDa and 1,000 kDa, but the present invention does not impose a specific limitation on this and can be adjusted according to needs.

[0022] In one embodiment of the present invention, the step of performing a chemical crosslinking reaction in step S100 includes, for example, mixing a crosslinking agent with a plurality of biodegradable materials, and then performing a chemical crosslinking reaction for 1 to 2 hours at a temperature between 160 and 190 degrees Celsius and a pressure between 1 MPa and 1.5 MPa. However, the present invention is not limited thereto, and can be appropriately adjusted according to the type and proportion of the selected biodegradable materials. In one embodiment of the present invention, the crosslinking agent used for the chemical crosslinking reaction includes, for example, at least one of di-tert-butyl peroxyisopropylbenzene, diisopropylbenzene peroxide, stannous isooctanoate, methylene diphenyl diisocyanate, epoxy soybean oil, maleated soybean oil, and epoxy soybean oil acrylate, and the above crosslinking agent accounts for, for example, 0.05wt% to 3.0wt% of the total weight of the plurality of biodegradable materials and the crosslinking agent, preferably 0.2wt% to 1.5wt%. The present invention is not specifically limited thereto, and in another embodiment of the present invention, other types of crosslinking agents can be selected, or the usage amount can be adjusted according to the type of crosslinking agent selected.

[0023] Continuing from the above, the method for making a biodegradable hot melt adhesive in one embodiment of the present invention can regulate the molecular weight of the hydrolyzed copolymer by a hydrolysis reaction, which helps to make a hot melt adhesive with good properties such as appropriate fluidity. In one embodiment of the present invention, the molecular weight of the hydrolyzed copolymer is, for example, between 50kDa and 300kDa, preferably between 100kDa and 150kDa, but the present invention does not make specific restrictions on this. In another embodiment of the present invention, the molecular weight of the hydrolyzed copolymer can be determined according to the desired performance of the hot melt adhesive, or according to the type and amount of the first additive and the second additive used in step S300. In one embodiment of the present invention, the smaller the molecular weight of the hydrolyzed copolymer, the higher the fluidity of the produced hot melt adhesive. It is worth mentioning that when the molecular weight of the hydrolyzed copolymer is above 100kDa, because it has a large cohesive force, it is beneficial to avoid excessive degradation of the hot melt adhesive after heating, resulting in poor performance.

[0024] In one embodiment of the present invention, the step S200 of hydrolyzing the copolymer includes, for example, mixing a hydrolysis agent with the copolymer, and performing a hydrolysis reaction for 1 to 1.5 hours under an environment of a temperature between 130 and 160 degrees Celsius and a pressure between 1 MPa and 1.5 MPa. However, the present invention is not limited thereto, and can be appropriately adjusted according to the type of biodegradable material selected and the molecular weight of the copolymer. In one embodiment of the present invention, the hydrolysis agent used for the hydrolysis reaction includes, for example, at least one of inorganic bases such as sodium hydroxide and potassium hydroxide, and the above-mentioned hydrolysis agent accounts for, for example, 0.05wt% to 3.0wt% of the total weight of the copolymer and the hydrolysis agent, and is preferably 0.2wt% to 1.5wt%. The present invention is also not specifically limited to this, and in another embodiment of the present invention, other types of hydrolysis agents can be selected, and the usage amount can also be adjusted according to the type of the selected hydrolysis agent.

[0025] Next, the method for making a biodegradable hot melt adhesive in one embodiment of the present invention uses a hydrolyzed copolymer to prepare the hot melt adhesive, and uses appropriate additives to obtain a biodegradable hot melt adhesive with excellent properties such as appropriate fluidity, wettability and molecular weight. Specifically, in one embodiment of the present invention, step S300 of mixing and heating the hydrolyzed copolymer, the first additive and the second additive includes, for example: mixing and stirring the hydrolyzed copolymer, the first additive and the second additive at a temperature between 130 degrees Celsius and 160 degrees Celsius and a pressure between 1 MPa and 1.5 MPa for 1 to 2 hours. However, the present invention is not limited thereto, and can be appropriately adjusted according to the type of biodegradable material selected and the molecular weight of the hydrolyzed copolymer.

[0026] It is worth mentioning that the method for making a biodegradable hot melt adhesive according to an embodiment of the present invention directly uses polymers (such as polymers such as polylactic acid and polycaprolactone) as materials, so it is helpful to produce biodegradable hot melt adhesive. Specifically, because the method for making a biodegradable hot melt adhesive according to an embodiment of the present invention uses polymers (such as polylactic acid) as materials, it may not involve the step of polymerizing monomers into polymers (such as the step of polymerizing polylactic acid monomers into polylactic acid). Further, the reaction conditions of the step of polymerizing monomers into polymers are relatively rigorous, which can be understood as having relatively strict requirements on the composition of the reactants. Therefore, because the method for making a biodegradable hot melt adhesive according to an embodiment of the present invention does not involve the step of polymerizing monomers into polymers, a single reactor can be used to continuously produce biodegradable hot melt adhesive.

[0027] In comparison, the conventional method for making biodegradable hot melt adhesive uses monomers as materials, and the production process involves the step of polymerizing monomers into polymers. Therefore, the conventional method faces the following problems: if a single reactor is used, the reactor must be thoroughly cleaned before the next batch of biodegradable hot melt adhesive can be made to avoid the next batch of monomers being contaminated by the biodegradable hot melt adhesive made from the previous batch remaining in the reactor; or multiple reactors must be used to perform monomer polymerization reactions and mixing reactions respectively. Based on the above, the method for making biodegradable hot melt adhesive in one embodiment of the present invention has the following advantages because the biodegradable hot melt adhesive can be made in a single reactor: 1. It saves the time required to replace the reaction container; 2. It reduces the material loss caused by replacing the reaction container; 3. It reduces energy consumption. In short, the method for making biodegradable hot melt adhesive provided by the present invention has the advantage of a simple production process.

[0028] In one embodiment of the present invention, the use of the first additive and the second additive in step S300 can allow the biodegradable hot melt adhesive to have suitable properties. In one embodiment of the present invention, the first additive, for example, accounts for 5wt% to 50wt% of the total weight of the hydrolyzed copolymer, the first additive, and the second additive, for example, accounts for 0.05wt% to 3.0wt% of the total weight of the hydrolyzed copolymer, the first additive, and the second additive. However, the present invention does not make specific restrictions on this, and the amount can be adjusted as needed.

[0029] In one embodiment of the present invention, the tackifying resin includes, for example, at least one of rosin resins and terpene resins. The plasticizer includes, for example, at least one of triethyl citrate, acetylated triethyl citrate, acetylated tributyl citrate, tributyrin, castor oil, and polyethylene glycol. The anti-hydrolysis agent includes, for example, at least one of epoxy compounds and carbodiimide anti-hydrolysis agents. The antioxidant includes, for example, at least one of a hindered phenol antioxidant and a phosphite antioxidant.

[0030] It should be noted that the present invention does not specifically limit the types of the first additive and the second additive, nor does it specifically limit the usage. In another embodiment of the present invention, other types of additives can be selected according to needs, and the usage can also be adjusted according to the type of the selected additive.

[0031] Example 1

[0032] Step S100: Mix two biodegradable materials (79.7wt% polylactic acid and 20wt% polycaprolactone) and 0.3wt% di-tert-butyl peroxyisopropylbenzene and place them in a reaction kettle, and carry out a chemical crosslinking reaction for 2 hours at a temperature of 180 degrees Celsius and a pressure of 1.5 MPa to form a copolymer with a molecular weight of 980 kDa. The molecular weight of the polylactic acid is, for example, 700 kDa, and the molecular weight of the polycaprolactone is, for example, 60 kDa.

[0033] Step S200: The copolymer and the hydrolysis agent are subjected to a hydrolysis reaction for 1 hour at a temperature of 150 degrees Celsius and a pressure of 1.5 MPa to form a hydrolyzed copolymer with a molecular weight of 140 kDa. The copolymer, for example, accounts for 99.5 wt% of the total weight of the copolymer and the hydrolysis agent, but the present invention is not limited thereto. The hydrolysis agent, for example, is sodium hydroxide, and the hydrolysis agent, for example, accounts for 0.5 wt% of the total weight of the copolymer and the hydrolysis agent. However, the present invention is not specifically limited to this, and the amount of the hydrolysis agent can be increased or decreased as appropriate, and the pH value of the mixture after the hydrolysis agent and the copolymer are mixed, for example, is allowed to fall between 8 and 10, thereby controlling the rate of the hydrolysis reaction. In one embodiment of the present invention, the higher the pH value, the faster the rate of the hydrolysis reaction.

[0034] Step S300: Mix the hydrolyzed copolymer, rosin resin, tributyrin, carbodiimide anti-hydrolysis agent and hindered phenol antioxidant, and stir for 1 hour at a temperature of 150 degrees Celsius and a pressure of 1 MPa to form a biodegradable hot melt adhesive with a consistency of 1,000 cps to 30,000 cps at 140 degrees Celsius to 180 degrees Celsius. The hydrolyzed copolymer, for example, accounts for 80.5 wt% of the total weight of the hydrolyzed copolymer, the first additive and the second additive. The rosin resin, for example, accounts for 10 wt% of the total weight of the hydrolyzed copolymer, the first additive and the second additive. The tributyrin, for example, accounts for 8 wt% of the total weight of the hydrolyzed copolymer, the first additive and the second additive. The carbodiimide anti-hydrolysis agent and hindered phenol antioxidant, for example, account for 1.5 wt% of the total weight of the hydrolyzed copolymer, the first additive and the second additive.

[0035] Example 2

[0036] Step S100: Mix three biodegradable materials (58.8wt% polylactic acid, 25wt% polyhydroxyalkanoate, 15wt% polyethylene glycol) and 1.2wt% methylene diphenyl diisocyanate and put them into a reaction kettle, and carry out a chemical crosslinking reaction for 2 hours at a temperature of 170 degrees Celsius and a pressure of 1.5MPa to form a copolymer with a molecular weight of 820kDa. The molecular weight of the polylactic acid is, for example, 700kDa, the molecular weight of the polyhydroxyalkanoate is, for example, 80kDa, and the molecular weight of the polyethylene glycol is, for example, 2kDa.

[0037] Step S200: The copolymer and the hydrolysis agent are subjected to a hydrolysis reaction for 1 hour at a temperature of 160 degrees Celsius and a pressure of 1.5 MPa to form a hydrolyzed copolymer with a molecular weight of 120 kDa. The copolymer is, for example, 99.5 wt% of the total weight of the copolymer and the hydrolysis agent, but the present invention is not limited thereto. The hydrolysis agent is, for example, sodium hydroxide, and the hydrolysis agent is, for example, 0.5 wt% of the total weight of the copolymer and the hydrolysis agent. However, the present invention is not specifically limited thereto, and the amount of the hydrolysis agent can be increased or decreased as appropriate, and for example, the pH value of the mixture after the hydrolysis agent and the copolymer are mixed falls between 8 and 10.

[0038] Step S300: Mix the hydrolyzed copolymer, hydrogenated rosin ester, acetyl triethyl citrate, carbodiimide anti-hydrolysis agent, and hindered phenol type antioxidant, and stir for 1 hour at a temperature of 150 degrees Celsius and a pressure of 1 MPa to form a biodegradable hot melt adhesive having a consistency of 1,000 cps to 30,000 cps at 140 degrees Celsius to 180 degrees Celsius. The hydrolyzed copolymer, for example, accounts for 65.0 wt% of the total weight of the hydrolyzed copolymer, the first additive, and the second additive. The hydrogenated rosin ester, for example, accounts for 20.0 wt% of the total weight of the hydrolyzed copolymer, the first additive, and the second additive. The acetyl triethyl citrate, for example, accounts for 13.0 wt% of the total weight of the hydrolyzed copolymer, the first additive, and the second additive. The carbodiimide anti-hydrolysis agent and hindered phenol type antioxidant, for example, account for 2.0 wt% of the total weight of the hydrolyzed copolymer, the first additive, and the second additive.

[0039] In summary, the present invention helps to improve the thermal stability of the biodegradable hot melt adhesive by mixing multiple biodegradable materials and performing a chemical cross-linking reaction, and the molecular weight of the hydrolyzed copolymer can be regulated by the hydrolysis reaction, which helps to prepare a biodegradable hot melt adhesive with good performance. In addition, the method for preparing the biodegradable hot melt adhesive provided by the present invention has the advantage of a simple production process.

[0040] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A method for preparing a biodegradable hot melt adhesive, characterized in that: include: Mixing a plurality of biodegradable materials and subjecting them to chemical cross-linking reaction to form a copolymer; hydrolyzing the copolymer to form a hydrolyzed copolymer; as well as The hydrolyzed copolymer, a first additive and a second additive are mixed and heated to form a biodegradable hot melt adhesive; The biodegradable materials include at least two of polylactic acid, polycaprolactone, polybutylene succinate, polyhydroxyalkanoate and polyethylene glycol, the first additive includes at least one of a tackifying resin and a plasticizer, and the second additive includes at least one of an antioxidant and an anti-hydrolysis agent.

2. The method for preparing the biodegradable hot melt adhesive according to claim 1, characterized in that: The steps for carrying out the chemical cross-linking reaction include: After a cross-linking agent is mixed with the biodegradable materials, a chemical cross-linking reaction is carried out for 1 to 2 hours at a temperature between 160 degrees Celsius and 190 degrees Celsius and a pressure between 1 MPa and 1.5 MPa.

3. The method for making a biodegradable hot melt adhesive according to claim 2, characterized in that: The cross-linking agent comprises at least one of di-tert-butyl peroxyisopropylbenzene, diisopropyl peroxide, stannous isooctanoate, methylene diphenyl diisocyanate, epoxy soybean oil, maleated soybean oil and epoxy soybean oil acrylate, and the cross-linking agent accounts for 0.05wt% to 3.0wt% of the total weight of the biodegradable materials and the cross-linking agent.

4. The method for making a biodegradable hot melt adhesive according to claim 1, characterized in that: The molecular weight of the copolymer is between 500 kDa and 1,500 kDa.

5. The method for making a biodegradable hot melt adhesive according to claim 1, characterized in that: The step of hydrolyzing the copolymer comprises: A hydrolysis agent is mixed with the copolymer, and a hydrolysis reaction is carried out for 1 hour to 1.5 hours at a temperature between 130 degrees Celsius and 160 degrees Celsius and a pressure between 1 MPa and 1.5 MPa.

6. The method for making a biodegradable hot melt adhesive according to claim 5, characterized in that: The hydrolysis reagent comprises at least one of sodium hydroxide and potassium hydroxide, and the hydrolysis reagent accounts for 0.05 wt % to 3.0 wt % of the total weight of the copolymer and the hydrolysis reagent.

7. The method for making a biodegradable hot melt adhesive according to claim 1, characterized in that: The molecular weight of the hydrolyzed copolymer is between 50 kDa and 300 kDa.

8. The method for making a biodegradable hot melt adhesive according to claim 1, characterized in that: The step of mixing and heating the hydrolyzed copolymer, the first additive and the second additive comprises: The hydrolyzed copolymer, the first additive and the second additive are mixed and stirred for 1 to 2 hours at a temperature between 130 degrees Celsius and 160 degrees Celsius and a pressure between 1 MPa and 1.5 MPa.

9. The method for making a biodegradable hot melt adhesive according to claim 1, characterized in that: The first additive accounts for 5 wt % to 50 wt % of the total weight of the hydrolyzed copolymer, the first additive and the second additive; the second additive accounts for 0.05 wt % to 3.0 wt % of the total weight of the hydrolyzed copolymer, the first additive and the second additive.

10. The method for making a biodegradable hot melt adhesive according to claim 1, characterized in that: The tackifying resin includes at least one of rosin resins and terpene resins; the plasticizer includes at least one of triethyl citrate, acetylcitrate triethyl, acetylated tributyl citrate, tributyrin, castor oil and polyethylene glycol; the anti-hydrolysis agent includes at least one of epoxy compounds and carbodiimide anti-hydrolysis agents, and the antioxidant includes at least one of a hindered phenol antioxidant and a phosphite antioxidant.

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