阅读说明：本技术 一种可生物降解的压敏胶粘剂 (Biodegradable pressure-sensitive adhesive ) 是由 都佩华 高俊 刘宁宁 秦佳伟 于 2021-01-26 设计创作，主要内容包括：一种可生物降解的压敏胶粘剂,本发明涉及压敏胶技术领域,它由如下成分组成：与乳酸为主要原料反应的脂族聚酯树脂、树脂和溶剂；所述的乳酸与脂族聚酯树脂的重量比例为20～60％；所述的脂族聚酯树脂与树脂的重量比为2～30％；其中树脂包含松香或松香衍生物、萜烯树脂中的一种或两者混合而成；上述乳酸由L-乳酸和D-单乳酸组成,两者的摩尔比L/D为5～9；上述脂族聚酯树脂的数均分子量为20000～150000,Tg为5℃～-60℃。其能够被生物分解,且生物分解对被粘物具有足够的初始粘附力,甚至在粘附后也不会从被粘物上脱落,并且对表面基板具有优异的粘附性。(The invention discloses a biodegradable pressure-sensitive adhesive, which relates to the technical field of pressure-sensitive adhesives and comprises the following components: aliphatic polyester resin, resin and solvent which react with lactic acid as a main raw material; the weight ratio of the lactic acid to the aliphatic polyester resin is 20-60%; the weight ratio of the aliphatic polyester resin to the resin is 2-30%; wherein the resin comprises one or two of rosin or rosin derivative and terpene resin; the lactic acid consists of L-lactic acid and D-mono-lactic acid, and the molar ratio L/D of the L-lactic acid to the D-mono-lactic acid is 5-9; the aliphatic polyester resin has a number average molecular weight of 20000 to 150000 and a Tg of 5 ℃ to-60 ℃. Which is capable of being biodegraded, has a sufficient initial adhesion to an adherend, does not fall off from the adherend even after adhesion, and has excellent adhesion to a surface substrate.)

1. A biodegradable pressure sensitive adhesive characterized by: it comprises the following components: aliphatic polyester resin, resin and solvent which react with lactic acid as a main raw material; the weight ratio of the lactic acid to the aliphatic polyester resin is 20-60%; the weight ratio of the aliphatic polyester resin to the resin is 2-30%; wherein the resin comprises one or two of rosin or rosin derivative and terpene resin; the lactic acid consists of L-lactic acid and D-mono-lactic acid, and the molar ratio L/D of the L-lactic acid to the D-mono-lactic acid is 5-9; the aliphatic polyester resin has a number average molecular weight of 20000 to 150000 and a Tg of 5 ℃ to-60 ℃.

2. A biodegradable pressure sensitive adhesive according to claim 1, wherein: the resin concentration is 30-60%.

3. A biodegradable pressure sensitive adhesive according to claim 1, wherein: the weight ratio of the rosin or the rosin derivative to the terpene resin is 5-30%.

4. A biodegradable pressure sensitive adhesive according to claim 1, wherein: the solvent is formed by mixing one or more of ethyl acetate, butyl acetate, toluene, xylene, methanol and water.

Technical Field

The invention relates to the technical field of pressure-sensitive adhesives, in particular to a biodegradable pressure-sensitive adhesive.

Background

Adhesive labels using thermoplastic films as surface substrates are peeled from containers after use or incinerated or discarded in the soil while still attached to the containers. In recent years, from the viewpoint of environmental protection, these processing methods have raised the following problems: carbon dioxide is generated during incineration, and is one of the causes of global warming; in addition, high heat values may damage the incinerator or generate toxic gases; on the other hand, when it is discarded in the soil, the tag and binder decompose at a very slow rate, thus remaining semi-permanently in the soil, resulting in destruction of the ecosystem in the soil; in addition, as the amount of waste increases, the high efficiency of the treatment equipment becomes difficult to guarantee.

Currently, biodegradable adhesive labels have been proposed as a means for solving the above-mentioned problems. That is, the adhesive label uses a biodegradable resin which is a material decomposed by microscopic formation in soil and is used for a surface base material, an adhesive, a release sheet, and the like constituting the adhesive label. As a technique of a biodegradable adhesive using a resin of an adhesive excellent in biodegradability instead of natural rubber, a biodegradable pressure-sensitive adhesive technique has been reported which comprises 55% by weight or more of lactic acid residues, an aliphatic polyester having a molar ratio of L lactic acid to D lactic acid of 0.11 to 9 in terms of a viscosity of 0.2 to 1.0dl/g, and a natural adhesive resin as essential components; since the aliphatic polyesters used in the prior art contain 55% by weight or more of lactic acid residues, the glass transition temperature (Tg) tends to be high. Therefore, the reported pressure-sensitive adhesive has low adhesive strength to an adherend and insufficient adhesive force to a surface substrate.

Disclosure of Invention

The present invention has been made in view of the drawbacks and disadvantages of the prior art, and an object of the present invention is to provide a rationally designed biodegradable pressure-sensitive adhesive which can be biodegraded and has sufficient initial adhesion to an adherend, does not fall off from the adherend even after adhesion, and has excellent adhesion to a surface substrate.

In order to achieve the purpose, the invention adopts the following technical scheme: it comprises the following components: aliphatic polyester resin, resin and solvent which react with lactic acid as a main raw material; the weight ratio of the lactic acid to the aliphatic polyester resin is 20-60%; the weight ratio of the aliphatic polyester resin to the resin is 2-30%; wherein the resin comprises one or two of rosin or rosin derivative and terpene resin; the lactic acid consists of L-lactic acid and D-mono-lactic acid, and the molar ratio L/D of the L-lactic acid to the D-mono-lactic acid is 5-9; the aliphatic polyester resin has a number average molecular weight of 20000 to 150000 and a Tg of 5 ℃ to-60 ℃.

Further, the resin concentration of the pressure-sensitive adhesive is 30-60%.

Further, the weight ratio of the rosin or rosin derivative to the terpene resin is 5-30%.

Further, the solvent is formed by mixing one or more of ethyl acetate, butyl acetate, toluene, xylene, methanol and water.

After the components are adopted, the invention has the beneficial effects that: the present invention provides a biodegradable pressure-sensitive adhesive which is capable of being biodegraded, has sufficient initial adhesion to an adherend, does not fall off from the adherend even after adhesion, and has excellent adhesion to a surface substrate.

Description of the drawings:

FIG. 1 is a table of data for examples of the present invention and comparative examples.

The specific implementation mode is as follows:

the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The first embodiment is as follows:

10g of an adhesive-imparting T-803L terpene resin manufactured by Mitsukawa chemical company was added to 10g of ethyl acetate, and sufficiently stirred at room temperature for about 1 hour until the solid content was completely dissolved, to prepare a 50% tackifier resin solution A; then, using 4 parts by weight (L/D) of 100 parts by weight of a polylactic acid resin solution bioecolHYD-035E (nonvolatile component 50%, Tg-5 ℃, number average molecular weight 25000, D lactic acid polymerization ratio 20 mol%) produced by Toyo Boseki K.K. as a main polymer base of the pressure-sensitive adhesive, 2.5 parts by weight of the above tackifier resin solution A was added thereto and sufficiently stirred until completely dissolved, to obtain the biodegradable pressure-sensitive adhesive of example one;

the pressure-sensitive adhesive of example one was coated on release paper, and the coating weights after drying were 25g/m, respectively²The peel strength of the dried release paper is lower than that of the release paper directly coated, and the biodegradable double-sided adhesive tape is manufactured; then, the adhesion of the biodegradable double-sided tape was measured, and the adhesion was found to be as follows: the immediate adhesion is 17N/25mm, the adhesion after 1h is 20N/25mm, and the adhesion after 48h is 21N/25 mm; the biodegradable double-sided adhesive tape cut into an area of 100mm × 100mm was then stuck to a float glass plate of known quality, and then the quality (mass of about 0.25g of pressure-sensitive adhesive) was measured and recorded; placing 5kg of the waste in an outdoor compost (capacity 100 liters) and placing a glass plate having a biodegradable pressure-sensitive adhesive thereon; further, garbage of 50mm thickness was left to stand for one month, and then the glass plate was taken out, washed with water to such an extent that the pressure-sensitive adhesive did not fall off, dried at 60 ℃ for 24 hours, and then measured for mass to determine the residual mass of the pressure-sensitive adhesive; the following formula is adopted: the residual ratio after biodegradation was determined to be 0.9%, which is the adhesion quality after the test/adhesion quality before the test × 100 (%).

Example two:

10g of an adhesive-imparting T-803L terpene resin manufactured by Mitsukawa chemical company was added to 10g of ethyl acetate, and sufficiently stirred at room temperature for about 1 hour until the solid content was completely dissolved, to prepare a 50% tackifier resin solution A; then, 4 parts by weight (L/D) of 100 parts by weight of a polylactic acid resin solution bioecolHYD-035E (nonvolatile component 50%, Tg-5 ℃, number average molecular weight 25000, D lactic acid polymerization ratio 20 mol%) produced by Toyo Boseki K.K. was used as a main polymer base of the pressure-sensitive adhesive, and 5 parts by weight of the above tackifier resin solution A was added thereto and sufficiently stirred until completely dissolved to obtain the biodegradable pressure-sensitive adhesive of example two;

the pressure-sensitive adhesive of example two was coated on release paper, and the coating amounts after drying were 25g/m, respectively²The peel strength of the dried release paper is lower than that of the release paper directly coated, and the biodegradable double-sided adhesive tape is manufactured; then, the adhesive force of the pressure-sensitive adhesive tape was measured, and as a result, the adhesive force was found to be as follows: the immediate adhesion is 21N/25mm, the adhesion after 1h is 22N/25mm, and the adhesion after 48h is 24N/25 mm; the biodegradable double-sided adhesive tape cut into an area of 100mm × 100mm was then stuck to a float glass plate of known quality, and then the quality (mass of about 0.25g of pressure-sensitive adhesive) was measured and recorded; placing 5kg of the waste in an outdoor compost (capacity 100 liters) and placing a glass plate having a biodegradable pressure-sensitive adhesive thereon; further, garbage of 50mm thickness was left to stand for one month, and then the glass plate was taken out, washed with water to such an extent that the pressure-sensitive adhesive did not fall off, dried at 60 ℃ for 24 hours, and then measured for mass to determine the residual mass of the pressure-sensitive adhesive; the following formula is adopted: the residual ratio after biodegradation was determined to be 2.0% as adhesion quality after the test/adhesion quality before the test × 100 (%).

Example three:

10g of an adhesive-imparting T-803L terpene resin manufactured by Mitsukawa chemical company was added to 10g of ethyl acetate, and sufficiently stirred at room temperature for about 1 hour until the solid content was completely dissolved, to prepare a 50% tackifier resin solution A; then, 4 parts by weight (L/D) of 100 parts by weight of a polylactic acid resin solution bioecolHYD-035E (nonvolatile component 50%, Tg-5 ℃, number average molecular weight 25000, D lactic acid polymerization ratio 20 mol%) produced by Toyo Boseki K.K. was used as a main polymer base of the pressure-sensitive adhesive, 10 parts by weight of the above tackifier resin solution A was added thereto and sufficiently stirred until completely dissolved, to obtain the biodegradable pressure-sensitive adhesive of example III;

the pressure sensitive adhesive of example threeThe agent was coated on release paper, and the coating weight after drying was 25g/m²The peel strength of the dried release paper is lower than that of the release paper directly coated, and the biodegradable double-sided adhesive tape is manufactured; then, the adhesive force of the pressure-sensitive adhesive tape was measured, and as a result, the adhesive force was found to be as follows: the immediate adhesion is 19N/25mm, the adhesion after 1h is 19N/25mm, and the adhesion after 48h is 20N/25 mm; the biodegradable double-sided adhesive tape cut into an area of 100mm × 100mm was then stuck to a float glass plate of known quality, and then the quality (mass of about 0.25g of pressure-sensitive adhesive) was measured and recorded; placing 5kg of the waste in an outdoor compost (capacity 100 liters) and placing a glass plate having a biodegradable pressure-sensitive adhesive thereon; further, garbage of 50mm thickness was left to stand for one month, and then the glass plate was taken out, washed with water to such an extent that the pressure-sensitive adhesive did not fall off, dried at 60 ℃ for 24 hours, and then measured for mass to determine the residual mass of the pressure-sensitive adhesive; the following formula is adopted: the residual ratio after biodegradation was determined to be 2.2% as adhesion quality after the test/adhesion quality before the test × 100 (%).

Example four:

10G of 224-G95 rosin ester for imparting adhesiveness, manufactured by Jiangxi Xingtai chemical company, was added to 10G of ethyl acetate and sufficiently stirred at room temperature for about 1 hour until the solid content was completely dissolved, to prepare a 50% tackifier resin solution B; then, 4 parts by weight (L/D) of 100 parts by weight of a polylactic acid resin solution bioecolHYD-035E (nonvolatile component 50%, Tg-5 ℃, number average molecular weight 25000, D lactic acid polymerization ratio 20 mol%) produced by Toyo Boseki K.K. was used as a main polymer base of the pressure-sensitive adhesive, and 5 parts by weight of the above tackifier resin solution B was added thereto and sufficiently stirred until completely dissolved to obtain a biodegradable pressure-sensitive adhesive of example IV;

the pressure-sensitive adhesive of example four was coated on release paper in an amount of 25g/m after drying²The peel strength of the dried release paper is lower than that of the release paper directly coated, and the biodegradable double-sided adhesive tape is manufactured; then, the adhesive force of the pressure-sensitive adhesive tape was measured, and as a result, the adhesive force was foundThe following were used: the immediate adhesion is 22N/25mm, the adhesion after 1h is 25N/25mm, and the adhesion after 48h is 29N/25 mm; the biodegradable double-sided adhesive tape cut into an area of 100mm × 100mm was then stuck to a float glass plate of known quality, and then the quality (mass of about 0.25g of pressure-sensitive adhesive) was measured and recorded; placing 5kg of the waste in an outdoor compost (capacity 100 liters) and placing a glass plate having a biodegradable pressure-sensitive adhesive thereon; further, garbage of 50mm thickness was left to stand for one month, and then the glass plate was taken out, washed with water to such an extent that the pressure-sensitive adhesive did not fall off, dried at 60 ℃ for 24 hours, and then measured for mass to determine the residual mass of the pressure-sensitive adhesive; the following formula is adopted: the residual ratio after biodegradation was determined to be 1.8%, which is the adhesion quality after the test/adhesion quality before the test × 100 (%).

Example five:

10G of 224-G95 rosin ester for imparting adhesiveness, manufactured by Jiangxi Xingtai chemical company, was added to 10G of ethyl acetate and sufficiently stirred at room temperature for about 1 hour until the solid content was completely dissolved, to prepare a 50% tackifier resin solution B; then, 4 parts by weight (L/D) of 100 parts by weight of a polylactic acid resin solution bioecolHYD-035E (nonvolatile component 50%, Tg-5 ℃, number average molecular weight 25000, D lactic acid polymerization ratio 20 mol%) produced by Toyo Boseki K.K. was used as a main polymer base of the pressure-sensitive adhesive, 10 parts by weight of the above tackifier resin solution B was added thereto and sufficiently stirred until completely dissolved, to obtain the biodegradable pressure-sensitive adhesive of example V;

the pressure-sensitive adhesive of example five was coated on release paper in an amount of 25g/m after drying²The peel strength of the dried release paper is lower than that of the release paper directly coated, and the biodegradable double-sided adhesive tape is manufactured; then, the adhesive force of the pressure-sensitive adhesive tape was measured, and as a result, the adhesive force was found to be as follows: the immediate adhesion is 23N/25mm, the adhesion after 1h is 23N/25mm, and the adhesion after 48h is 27N/25 mm; the biodegradable double-sided adhesive tape cut into an area of 100mm × 100mm was then stuck to a float glass plate of known quality, and the quality was measured and recorded (about 0.25g of pressure-sensitive adhesive)Mass of); placing 5kg of the waste in an outdoor compost (capacity 100 liters) and placing a glass plate having a biodegradable pressure-sensitive adhesive thereon; further, garbage of 50mm thickness was left to stand for one month, and then the glass plate was taken out, washed with water to such an extent that the pressure-sensitive adhesive did not fall off, dried at 60 ℃ for 24 hours, and then measured for mass to determine the residual mass of the pressure-sensitive adhesive; the following formula is adopted: the residual ratio after biodegradation was determined to be 2.4% as adhesion quality after the test/adhesion quality before the test × 100 (%).

Comparative example one:

a polylactic acid resin solution bioecolHYD-035E (nonvolatile content 50%, Tg-5 ℃, number average molecular weight 25000, D lactic acid polymerization ratio 20 mol%) having a weight ratio of 4 (L/D) of 100, manufactured by Toyo Boseki K.K., was coated on a release paper in an amount of 25g/m after drying²The peel strength of the dried release paper is lower than that of the release paper directly coated, and the biodegradable double-sided adhesive tape is manufactured; then, the adhesive force of the pressure-sensitive adhesive tape was measured, and as a result, the adhesive force was found to be as follows: the immediate adhesion is 4N/25mm, the adhesion after 1h is 17N/25mm, and the adhesion after 48h is 15N/25 mm; the biodegradable double-sided adhesive tape cut into an area of 100mm × 100mm was then stuck to a float glass plate of known quality, and then the quality (mass of about 0.25g of pressure-sensitive adhesive) was measured and recorded; placing 5kg of the waste in an outdoor compost (capacity 100 liters) and placing a glass plate having a biodegradable pressure-sensitive adhesive thereon; further, garbage of 50mm thickness was left to stand for one month, and then the glass plate was taken out, washed with water to such an extent that the pressure-sensitive adhesive did not fall off, dried at 60 ℃ for 24 hours, and then measured for mass to determine the residual mass of the pressure-sensitive adhesive; the following formula is adopted: the residual ratio after biodegradation was determined to be 0.6%, which is the adhesion quality after the test/adhesion quality before the test × 100 (%).

Comparative example two:

a rubber-based pressure-sensitive adhesive BP-809A manufactured by grease industries, 100 parts by weight, was coated on release paper in amounts of 25g/m after drying²The peel strength of the dried release paper is lower than that of the release paper directly coated, and the biodegradable double-sided adhesive tape is manufactured; then, the adhesive force of the pressure-sensitive adhesive tape was measured, and as a result, the adhesive force was found to be as follows: the immediate adhesion is 5N/25mm, the adhesion after 1h is 7N/25mm, and the adhesion after 48h is 8N/25 mm; the biodegradable double-sided adhesive tape cut into an area of 100mm × 100mm was then stuck to a float glass plate of known quality, and then the quality (mass of about 0.25g of pressure-sensitive adhesive) was measured and recorded; placing 5kg of the waste in an outdoor compost (capacity 100 liters) and placing a glass plate having a biodegradable pressure-sensitive adhesive thereon; further, garbage of 50mm thickness was left to stand for one month, and then the glass plate was taken out, washed with water to such an extent that the pressure-sensitive adhesive did not fall off, dried at 60 ℃ for 24 hours, and then measured for mass to determine the residual mass of the pressure-sensitive adhesive; the following formula is adopted: the residual ratio after biodegradation was determined to be 85.4%, which is the adhesion quality after the test/adhesion quality before the test × 100 (%).

Referring to fig. 1, the biodegradable pressure-sensitive adhesives prepared in examples one to five had good adhesion and were biodegradable.

After the components are adopted, the beneficial effects of the embodiment are as follows: the present invention provides a biodegradable pressure-sensitive adhesive which is capable of being biodegraded, has sufficient initial adhesion to an adherend, does not fall off from the adherend even after adhesion, and has excellent adhesion to a surface substrate.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and/or modifications of the invention can be made, and equivalents and modifications of some features of the invention can be made without departing from the spirit and scope of the invention.