Polyester resin, preparation method thereof, polyester pressure-sensitive adhesive and pressure-sensitive adhesive product

Abstract

A polyester resin, a preparation method thereof and a polyester pressure-sensitive adhesive using the same. The polyester resin is a copolymer of a carboxyl-terminated polyester, a non-crystalline carbon dioxide-based polyester diol and a modified diol, and the mass fraction ratio of the carboxyl-terminated polyester, the non-crystalline carbon dioxide-based polyester diol and the modified diol is: (10-30): (50-99): (2-30). The preparation method of the polyester resin of the present invention comprises: putting each raw material into a reaction kettle, heating to 100-180°C, adding a catalyst of 1‰-2% of the total mass of the raw materials, vacuum polycondensing, and cooling to obtain the polyester resin. The peel strength and bonding performance of the polyester pressure-sensitive adhesive of the present invention are better than those of the existing pressure-sensitive adhesives.

Description

Technical Field

[0001] The present invention belongs to the technical field of pressure-sensitive adhesives, and in particular, relates to polyester resin, a preparation method thereof, a polyester pressure-sensitive adhesive and a pressure-sensitive adhesive product. Background Art

[0002] Pressure sensitive adhesive is a viscoelastic body that has both the viscous properties of a liquid and the elastic properties of a solid. It can be bonded to any smooth surface of an adherend immediately by applying pressure. At the same time, if the adhesive surface of the adherend is damaged, the adhesive will not contaminate the adherend surface. In recent years, with the growth of demand for packaging, office supplies and various labels, people's demand for pressure sensitive adhesives has also increased.

[0003] The components of commonly used pressure-sensitive adhesives include three main ingredients: base resin, tackifying resin, and plasticizer. The base resin is used to improve the cohesive force of the pressure-sensitive adhesive, while the tackifying resin provides initial adhesion. However, the addition of tackifying resin to the traditional pressure-sensitive adhesive formula, although it makes the base resin pressure-sensitive, significantly weakens the cohesive properties of the base resin, resulting in a decrease in the overall peel strength and tackiness of the pressure-sensitive tape. This is because conventional base resins do not contain long-chain branching structures, and base resins and tackifying resins often belong to different categories of resins. The compatibility between base resins and tackifying resins is poor, resulting in a significant degree of phase separation in the pressure-sensitive adhesive formula, thereby affecting the tackiness of the pressure-sensitive adhesive.

[0004] U.S. patent application US20170283666A1 discloses a pressure-sensitive adhesive composition, comprising a block copolymer, wherein the block copolymer comprises a first block having a glass transition temperature of 50°C or higher, and a second block having a glass transition temperature of -10°C or lower, wherein the first block may be an alkyl (meth)acrylate, and the second block may be an alkyl acrylate having an alkyl group of 1 to 4 carbon atoms. However, the pressure-sensitive adhesive composition has problems of poor adhesion and low peel strength.

[0005] Chinese patent application CN117447954A discloses a degradable hot-melt pressure-sensitive adhesive, which comprises the following components by mass: 65 to 85 parts of degradable plastic, 5 to 25 parts of degradable tackifying resin, 1 to 9 parts of degradable plasticizer, 0 to 10 parts of filler, and 1 part of antioxidant, wherein the degradable plastic is one or more of polybutylene succinate, polylactic acid, polyglycolic acid, polybutylene terephthalate-adipate, and polypropylene carbonate, and the degradable tackifying resin is one or more of rosin, hydrogenated rosin, disproportionated rosin, esterified rosin, C5 petroleum resin, C9 petroleum resin, and terpene resin. However, the pressure-sensitive adhesive has poor adhesion and tack retention.

[0006] Chinese patent application CN105802145A discloses a biodegradable thermoplastic elastomer, which consists of the following components: 20-120 parts of biodegradable resin, 10-120 parts of filler, 0.2-5 parts of coupling agent, 0.03-5 parts of cross-linking agent, 0.1-10 parts of auxiliary cross-linking agent, 0.2-10 parts of lubricant, 5-100 parts of plasticizer and 0.1-40 parts of compatibilizer. The biodegradable resin is one or more of polybutylene succinate, polybutylene succinate-adipate, polybutylene adipate-terephthalate, polylactic acid, polypropylene carbonate, polycaprolactone, polyhydroxyalkanoate and polyvinyl alcohol. The stickiness and adhesion of the elastomer cannot meet the requirements of pressure-sensitive adhesive.

[0007] Chinese patent application CN117384577A discloses a carbon dioxide-degradable pressure-sensitive adhesive material. Diacetyl-L-tartaric anhydride is added to the polymerization reaction of carbon dioxide and epoxide, and the carbon dioxide-based degradable pressure-sensitive adhesive material is prepared through a ternary polymerization reaction. However, when it is used as a pressure-sensitive adhesive resin to prepare a pressure-sensitive adhesive, it has poor compatibility with a tackifying resin, a significant degree of phase separation, and the adhesion and holding power of the pressure-sensitive adhesive cannot meet the requirements.

[0008] It can be seen that the base resin in the prior art cannot provide the required peel strength and adhesion. Summary of the invention

[0009] Based on this, the present invention aims to overcome at least one defect of the prior art and provide a polyester resin, a preparation method and a polyester pressure-sensitive adhesive.

[0010] In a first aspect, the present invention relates to a polyester resin, wherein the polyester resin is a copolymer of a carboxyl-terminated polyester, a non-crystalline carbon dioxide-based polyester diol and a modified diol, wherein the mass fraction ratio of the carboxyl-terminated polyester, the non-crystalline carbon dioxide-based polyester diol and the modified diol is: (10-30): (50-99): (2-30), and the structural formula of the modified diol is as shown in Formula 1, Formula 2 or Formula 3.

[0011]

[0012] in:

[0013] R1 is a C1-12 alkyl group;

[0014] R2 is a C1-12 alkyl group;

[0015] R3 is a C1-12 alkyl group;

[0016] R4 is H or C1-12 alkyl;

[0017] R5 is a C1-12 alkyl group.

[0018] In a second aspect, the present invention relates to a method for preparing a polyester resin, comprising the following steps:

[0019] The carboxyl-terminated polyester, the non-crystalline carbon dioxide-based polyester diol and the modified diol are placed in a reaction kettle in the following mass proportions: (10-30): (50-99): (2-30), and after heating to 100-180°C, a catalyst in an amount of 1‰-2% of the total mass of the carboxyl-terminated polyester, the non-crystalline carbon dioxide-based polyester diol and the modified diol is added, vacuum polycondensation is performed, and cooling is performed to obtain the polyester-type resin.

[0020] In a third aspect, the present invention also relates to a polyester pressure-sensitive adhesive, comprising the following components calculated by mass: 50 to 99 parts of the polyester resin and 0.1 to 10 parts of an additive.

[0021] In a fourth aspect, the present invention also relates to a pressure-sensitive adhesive product, comprising a substrate and a pressure-sensitive adhesive layer attached to the substrate, wherein the pressure-sensitive adhesive layer comprises the polyester pressure-sensitive adhesive.

[0022] Therefore, the beneficial effects of the present invention are: the polyester resin of the present invention itself has excellent properties, and the peel strength and bonding properties of the polyester pressure-sensitive adhesive prepared therefrom are more excellent than those of the existing pressure-sensitive adhesives. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is the infrared spectrum of modified diol 1. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific implementation methods.

[0025] Regarding the first aspect of the present invention, the polyester-type resin includes a modified diol described in Formula 1, Formula 2 or Formula 3, which has a side chain, and the side chain contains an ester group. The modified diol and a non-crystalline carbon dioxide-based polyester diol and a carboxyl-terminated polyester are reacted in a certain proportion to prepare a polyester resin containing a carboxyl-terminated polyester segment, a non-crystalline carbon dioxide-based polyester segment and a side chain segment. The carboxyl-terminated polyester segment is a hard segment that can be used to ensure the cohesive strength of the polyester resin. The non-crystalline carbon dioxide-based polyester segment is a soft segment that can ensure the elasticity of the polyester resin. The modified diol segment contains a side chain, which is connected to the polyester resin, so that the branching degree of the polyester resin is increased, the glass transition temperature is reduced, and the overall molecular chain activity of the resin is enhanced. The ester group contained in the side chain can provide a large number of hydrogen bonds, which are easy to form hydrogen bond adhesion with the bonding substrate and have good initial adhesion.

[0026] In one preferred embodiment, R1 can be an alkyl group of C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12, and R1 is preferably an alkyl group of C1-4.

[0027] In one preferred embodiment, R2 can be an alkyl group of C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12, and R2 is preferably an alkyl group of C1-4.

[0028] In one preferred embodiment, R3 can be an alkyl group of C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12, and R3 is preferably an alkyl group of C1-4.

[0029] In one preferred embodiment, R4 can be H, or an alkyl group of C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12, and R4 is preferably an alkyl group of C1-4.

[0030] In one preferred embodiment, R5 can be an alkyl group of C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12, and R5 is preferably an alkyl group of C1-4.

[0031] For the polyester resin of the present invention, a certain amount of modified diol needs to be added to ensure that the polyester resin has the required branching degree and hydrogen bonding, so as to have good initial adhesion and sustained bonding performance. Therefore, the required mass fraction is more than 3. If too much modified diol is added, the required hard segment and soft segment ratio will be reduced, affecting the relevant properties of the polyester resin. Therefore, the mass fraction of the modified diol should be less than 30. In one preferred embodiment, the mass fraction of the modified diol is preferably 4 to 25, more preferably 5 to 20, and also 7, 9, 11, 13, 15, 17 or 19.

[0032] In one preferred embodiment, the number average molecular weight of the carboxyl-terminated polyester may be 1,000 to 3,000. Since the molecular weight of each chain segment will affect the performance of the polyester resin, for the carboxyl-terminated polyester, the higher the molecular weight, the stronger the crystallinity, and the stronger the ability to serve as a physical crosslinking point. In order to obtain better performance, the number average molecular weight of the carboxyl-terminated polyester may be above 1,000, but the crystallinity becomes stronger due to the excessively high molecular weight, which increases the microphase separation degree of the polyester-type pressure-sensitive adhesive, and instead causes the performance of the polyester-type pressure-sensitive adhesive to decrease. The number average molecular weight of the carboxyl-terminated polyester may be below 3,000. Specifically, the number average molecular weight of the carboxyl-terminated polyester may be 1,200, 1,400, 1,600, 1,800, 2,000, 2,200, 2,400, 2,600, 2,800 or 2,900.

[0033] In one preferred embodiment, the mass fraction of the carboxyl-terminated polyester is 10 to 30. Since the carboxyl-terminated polyester contains carboxyl groups, it can be used as a physical crosslinking point to form a polyester resin with a carbon dioxide-based polyester diol, thereby improving the cohesive strength of the overall resin, so that it can be used in the field of pressure-sensitive adhesives to meet the bonding properties of pressure-sensitive adhesives. The mass fraction of the carboxyl-terminated polyester can be more than 10 parts. As its content increases, the cohesive properties of the polyester resin will increase, but if the content of the carboxyl-terminated polyester is too high, the degree of phase separation will increase, and then the performance of the elastomer will decrease, causing the performance of the subsequent pressure-sensitive adhesive to decrease. At the same time, if the content of the carboxyl-terminated polyester is too high, the physical entanglement degree of the elastomer will also increase, and then the degradation rate of the elastomer will decrease. Therefore, the mass fraction of the carboxyl-terminated polyester is controlled to be less than 30 parts. Specifically, the mass fraction of the carboxyl-terminated polyester can be 12, 14, 16, 18, 20, 22, 24, 26 or 28.

[0034] In one preferred embodiment, the carboxyl-terminated polyester is polymerized from a C3-7 dibasic acid and a C3-7 diol.

[0035] In one preferred embodiment, the carboxyl-terminated polyester is preferably polybutylene succinate (PBS). PBS is a novel polymer degradable material, and its degradation mechanism is: first by hydrolysis of CO bonds, and then further degraded under the action of enzymes. PBS is a crystalline material, which can be used as a physical crosslinking point to form a copolyester elastomer with polycarbonate, thereby improving the cohesive strength of the overall resin, so that it can be applied in the field of pressure-sensitive adhesives, meeting the higher adhesion requirements of pressure-sensitive adhesives, and the raw material for PBS synthesis comes from biomass, which is a second type of carbon source, and has good degradation performance.

[0036] In one preferred embodiment, the carboxyl-terminated polybutylene succinate has a hydroxyl value of 37.4 to 112 mgKOH / g and a molecular weight of 1,000 to 3,000.

[0037] In one preferred embodiment, the number average molecular weight of the non-crystalline carbon dioxide-based polyester diol is 2,000 to 4,000. For the non-crystalline carbon dioxide-based polyester diol chain segment, when the molecular weight is too small, the chain segment is too short, and the elasticity of the polyester resin will be reduced. Therefore, its number average molecular weight is preferably above 2,000. When the molecular weight is too large, it is equivalent to a decrease in the content of the carboxyl-terminated polyester, and the strength of the polyester resin decreases. The number average molecular weight is preferably controlled below 3,000. Specifically, the number average molecular weight of the non-crystalline carbon dioxide-based polyester diol chain segment can be 2,200, 2,400, 2,600, 2,800, 3,000, 3,200, 3,400, 3,600 or 3,800.

[0038] In one preferred embodiment, the non-crystalline carbon dioxide-based polyester diol is preferably polypropylene carbonate diol (PPC), and its number average molecular weight is preferably 2,000-4,000. PPC is also a new type of polymer degradable material, which is a CO2-based diol derived from a third type of carbon source, has a fast degradation rate and a high degradation rate.

[0039] In one preferred embodiment, the hydroxyl value of the non-crystalline carbon dioxide-based polyester diol is 28.05 to 56.1 mgKOH / g.

[0040] In one preferred embodiment, the molecular weight of the polyester resin is 20,000 to 60,000, and the number average molecular weight is preferably 25,000 to 40,000, and more preferably 28,000 to 38,000. For polyester resin, its molecular weight is preferably above 20,000 to obtain better cohesion. When the molecular weight is too large, its degradation performance will be reduced. Therefore, the number average molecular weight is preferably below 60,000. The number average molecular weight of the polyester resin can be 22,000, 24,000, 26,000, 28,000, 30,000, 32,000, 34,000, 36,000, 38,000, 40,000, 42,000, 44,000, 46,000, 48,000, 50,000, 52,000, 54,000, 56,000 or 58,000.

[0041] Since the carboxyl-terminated polyester can be made of new polymer degradable materials, the non-crystalline carbon dioxide-based polyester diol is a new type of polymer degradable material, and the prepared polyester resin has good degradable properties.

[0042] The above-mentioned modified diols, carboxyl-terminated polyesters and non-crystalline carbon dioxide-based polyester diols are reacted in a certain proportion to obtain a polyester-type resin. This polyurethane pressure-sensitive adhesive resin contains carboxyl-terminated polyester segments, carbon dioxide-based polyester segments and side chain segments. The modified diol segments contain side chains, which are connected to the polyester resin, so that the branching degree of the polyester resin is improved, the overall molecular chain activity of the resin is enhanced, the ester bonds contained in the side chains can provide a large number of hydrogen bonds, it is easy to form hydrogen bond adhesion with the bonding substrate, and the initial adhesion is good.

[0043] Regarding the second aspect of the present invention, for the preparation method of polyester resin, in one preferred embodiment, a carboxyl-terminated polyester, a non-crystalline carbon dioxide-based polyester diol, and the modified diol are put into a reaction kettle in the following mass proportions: (10-20): (60-90): (5-20), and after heating to 130-150°C, a catalyst with a total mass of 3wt‰ to 8w‰ of the carboxyl-terminated polyester, the non-crystalline carbon dioxide-based polyester diol and the modified diol is added, and after vacuum polycondensation for 3-4 hours, the reaction is cooled to room temperature to obtain a polyester resin, and the vacuum degree is within 0.5 mmHg.

[0044] In one preferred embodiment, the preparation of the modified diol comprises the following steps:

[0045] An amine compound is added to an organic solvent, and an acrylate compound is added dropwise under the protection of an inert gas, and the reaction is carried out at 10 to 40° C. for 1 to 50 hours, and then liquid separation and extraction are performed to remove the organic solvent to obtain a self-made modified diol; wherein the molar ratio of the amine compound to the acrylate compound is (0.5 to 3):1.

[0046] In one preferred embodiment, an olamine compound is added to an organic solvent, an acrylate compound is added dropwise under the protection of an inert gas, the reaction is carried out at 15-35° C. for 10 to 30 hours, and then the mixture is washed with water, separated and extracted, and then the organic solvent is removed by distillation under reduced pressure to obtain the modified diol; wherein the molar ratio of the olamine compound to the acrylate compound is preferably (1 to 1.2):1; and the inert gas is preferably nitrogen and / or argon.

[0047] In one preferred embodiment, the alcoholamine compound is one or more of diethanolamine, 2-amino-2-methyl-1,3-propanediol, 2-amino-1,3-propanediol, and 3-amino-1,2-propanediol.

[0048] In one preferred embodiment, the acrylate compound is one or more of isooctyl acrylate, butyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, isooctyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

[0049] In one preferred embodiment, the organic solvent is methanol, ethanol or dimethylformamide.

[0050] In one preferred embodiment, the catalyst is tetrabutyl titanate, tetraisopropyl titanate or p-toluenesulfonic acid.

[0051] Regarding the polyester pressure-sensitive adhesive described in the third aspect of the present invention, in one preferred embodiment, the polyester resin is preferably 60 to 99 parts, more preferably 80 to 99 parts, and can also be 90 to 99 parts, or 95 to 99 parts. Since the polyester resin itself is easy to form hydrogen bonds with the bonding substrate and has good initial adhesion, the tackifying resin is an optional component, the polyester pressure-sensitive adhesive has good cohesive properties, and the peel strength and sustained adhesion of the pressure-sensitive adhesive can also be improved.

[0052] In one preferred embodiment, the polyester pressure-sensitive adhesive may further include 1 to 50 parts of a tackifying resin, wherein the tackifying resin is one or more of natural rosin, hydrogenated rosin, disproportionated rosin, esterified rosin, C5 petroleum resin, C9 petroleum resin, and terpene resin.

[0053] In one preferred embodiment, the additives include plasticizers, antioxidants, fillers, pigments, rheological additives, elastomers, light stabilizers, UV absorbers and other additives, such as desiccants, flow agents and flow control agents, surfactants or catalysts.

[0054] In one preferred embodiment, the plasticizer is preferably 1 to 5 parts, and the antioxidant is preferably 0.1 to 0.2 parts.

[0055] The plasticizer is one or more of epoxidized soybean oil, linseed oil, castor oil and palm oil.

[0056] In one preferred embodiment, the antioxidant is one or more of tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, di(tridecanol)thiodipropionate, and pentaerythritol tetrakis{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0057] Regarding the fourth aspect of the present invention, in one preferred embodiment, the substrate is selected from white paper, textiles, non-woven fabrics, polymers, metals or wood, and the substrate is preferably one of cellulose film, PET film or paper; and / or the thickness of the pressure-sensitive adhesive layer is 10 to 30 μm.

[0058] In one preferred embodiment, the pressure-sensitive adhesive product is an adhesive tape, an adhesive stick or a film roll.

[0059] In one preferred embodiment, the pressure-sensitive adhesive product has an initial adhesion of 5 or more, and / or a 180° peel strength of 6N / 25mm or more, and / or a lasting adhesion of 84h or more, and / or a degradation rate of 87% or more.

[0060] In summary, the present invention reacts the modified diol, the non-crystalline carbon dioxide-based polyester diol and the carboxyl-terminated polyester in a certain proportion to obtain a polyester resin, and the polyester resin contains a carboxyl-terminated polyester segment, a non-crystalline carbon dioxide-based polyester segment and a side chain segment, wherein the carboxyl-terminated polyester segment is a hard segment that can provide the cohesive strength required for the polyester resin, and the non-crystalline carbon dioxide-based polyester segment is a soft segment that can ensure the elasticity of the polyester resin. The modified diol segment contains a side chain that is connected to the polyester resin, so that the branching degree of the polyester resin is increased, the glass transition temperature is reduced, and the overall molecular chain activity of the resin is enhanced. The ester bond contained in the side chain can provide a large number of hydrogen bonds, which is easy to form hydrogen bond adhesion with the bonding substrate and has good initial adhesion. The polyester resin is formulated into a polyester pressure-sensitive adhesive, and a tackifying resin may be selectively added or not added. If the tackifying resin is not added, the polyester pressure-sensitive adhesive also has strong cohesive properties, and there is no phase separation problem caused by poor compatibility between the tackifying resin and the base resin, so the peel strength and the tack retention of the pressure-sensitive adhesive can be improved. The preferred polyester resin also has good degradability.

[0061] Example

[0062] The embodiments of the present invention are only used for illustrative description and should not be construed as limiting the present invention.

[0063] For simplicity, only some numerical ranges are explicitly disclosed herein. However, any lower limit can be combined with any upper limit to form an unambiguous range; and any lower limit can be combined with other lower limits to form an unambiguous range, and any upper limit can be combined with any other upper limit to form an unambiguous range. In addition, although not explicitly stated, each point or single value between the range endpoints is included in the range. Thus, each point or single value can be combined with any other point or single value as its own lower limit or upper limit or with other lower limits or upper limits to form an unambiguous range.

[0064] The above application content of the present invention is not intended to describe each disclosed embodiment or each implementation in the present invention. The following description more specifically illustrates exemplary embodiments. In many places throughout the application, guidance is provided by a series of examples, which can be used in various combinations. In each example, enumeration is only used as a representative group and should not be interpreted as exhaustive.

[0065] Unless otherwise specified, the raw materials used in the following examples are common commercially available products.

[0066] The preparation process of the modified diol 1 described in the following examples is as follows:

[0067] Diethanolamine is added to methanol, and isooctyl acrylate is added dropwise under the protection of inert gas N2, and the mixture is reacted at 25±5°C for 24 hours, and then the mixture is washed with water for at least three times and extracted, and then the methanol is distilled off under reduced pressure to obtain modified diol 1; wherein the molar ratio of diethanolamine to isooctyl acrylate is 1.05:1.

[0068] The modified diol 1 was subjected to infrared testing using a Nicolet iS50 Fourier transform infrared spectrometer from Thermo Fisher Scientific, USA, with a scanning wave number range of 400-4000 cm -1 The number of scans was 32. The sample to be tested was evenly spread on the dried KBr sheet and scanned and tested using a Fourier transform infrared spectrometer.

[0069] Infrared spectrum Figure 1 As shown, from Figure 1 It can be seen that 3500cm -1 is the stretching vibration peak of -OH, 2956cm -1 and 2868cm -1 Symmetric and asymmetric stretching vibration peaks of methylene, 1750 cm -1 is the stretching vibration peak of -C=O, 1180cm -1 The stretching vibration peak is -CN, indicating that the obtained product contains -OH, -CH2-, -C=O, and -CN. Diethanolamine and isooctyl acrylate undergo a Melk addition reaction to obtain the target product.

[0070] The preparation process of the modified diol 2 described in the following examples is as follows:

[0071] Diethanolamine was added to methanol, and butyl acrylate was added dropwise under the protection of inert gas N2, and the mixture was reacted at 25±5°C for 20 hours, and then the mixture was washed with water for at least three times and extracted, and then the methanol was removed by distillation under reduced pressure to obtain modified diol 2; wherein the molar ratio of diethanolamine to butyl acrylate was 1.2:1.

[0072] The preparation process of the modified diol 3 described in the following examples is as follows:

[0073] 2-amino-1,3-propanediol is added to ethanol, and isooctyl acrylate is added dropwise under the protection of inert gas N2, and the reaction is carried out at 25±5°C for 30 hours, and then the mixture is washed with water for at least three times and extracted, and then the ethanol is distilled off under reduced pressure to obtain modified diol 3; wherein the molar ratio of 2-amino-1,3-propanediol to isooctyl acrylate is 1.1:1.

[0074] The acid value is determined by dissolving an appropriate amount of sample in 25 mL of chloroform solution, using phenolphthalein as an indicator, and titrating with a 0.1 mol / L potassium hydroxide / ethanol standard solution until the color turns red and remains unchanged for 30 seconds. The acid value X of the sample is calculated according to formula (1):

[0075]

[0076] Wherein, 56.1 is the molar mass of potassium hydroxide (g / mol); X represents the acid value of the sample (mgKOH / g); V1 is the milliliters of the potassium hydroxide ethanol standard solution before titration (mL); V2 is the milliliters of the potassium hydroxide ethanol standard solution after titration (mL); C is the concentration of the potassium hydroxide ethanol standard solution (mol / L); and m is the weight of the titrated sample (g).

[0077] The preparation process of the carboxyl-terminated polybutylene succinate 1 described in the following examples is as follows:

[0078] 40 parts of 1,4-butanediol and 60 parts of succinic acid were put into a reactor, then heated to 165°C, and 0.3wt% of the total mass of 1,4-butanediol and succinic acid was added to the catalyst tetrabutyl titanate, and then reacted for about 3 hours, and then heated to 180°C for about 1 hour, and then heated to 205°C for vacuum polycondensation for 2 hours, and the acid ester was tested. The acid value was tested to be 70.125mgKOH / g (the calculated number average molecular weight was 1600, and the calculation formula was: wherein y is the acid value), and after cooling to room temperature, carboxyl-terminated polybutylene succinate 1 is obtained.

[0079] The preparation process of the carboxyl-terminated polybutylene succinate 2 described in the following examples is as follows:

[0080] 35 parts of 1,4-butanediol and 56 parts of succinic acid were put into a reactor, then heated to 160°C, and 0.2 wt% of the total mass of 1,4-butanediol and succinic acid was added as catalyst tetrabutyl titanate, and the reaction was carried out for about 3 hours, and then the temperature was raised to 180°C for about 1 hour, and then the temperature was raised to 200°C for vacuum polycondensation for 1 hour, and the acid ester was tested. The acid value was tested to be 102 mgKOH / g (the calculated number average molecular weight was 1,100), and carboxyl-terminated polybutylene succinate 2 was obtained after cooling to room temperature.

[0081] The preparation process of the carboxyl-terminated polybutylene succinate 3 described in the following examples is as follows:

[0082] 45 parts of 1,4-butanediol and 65 parts of succinic acid were put into a reactor, then heated to 165°C, and 0.5wt% of the total mass of 1,4-butanediol and succinic acid was added as catalyst tetrabutyl titanate, and then reacted for about 4 hours, and then heated to 180°C for about 2 hours, and then heated to 220°C for vacuum polycondensation for 4 hours, and its acid ester was tested. The acid value was tested to be 38.7mgKOH / g (the calculated number average molecular weight was 2,900), and after cooling to room temperature, carboxyl-terminated polybutylene succinate 3 was obtained.

[0083] The polypropylene carbonate diols described in the following examples were all purchased from Huizhou Daya Bay Dazhi Fine Chemical Co., Ltd. (Guangzhou Branch).

[0084] The number average molecular weight of the following examples is determined as follows:

[0085] GPC test method: The test was performed using a GPC instrument of model WATERS1515 from Water Company, USA, with tetrahydrofuran (THF) as the mobile phase at a flow rate of 0.1 mL / min and monodisperse polystyrene as the molecular weight calibration standard.

[0086] Example 1

[0087] A polyester resin, the preparation process of which is as follows:

[0088] Carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol (molecular weight of about 2,500), and the modified diol 1 are put into a reactor in a mass ratio of 10:90:5, and the temperature is raised to 130-150°C. A catalyst having a total mass of 5w‰ of carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol, and the modified diol 1 is added. After polycondensation for 4 hours in a vacuum degree of less than 0.5 mmHg, the resin is cooled to room temperature to obtain a polyester resin, and the molecular weight is determined by GPC to be about 32,000.

[0089] Example 2

[0090] A polyester resin, the preparation process of which is as follows:

[0091] Carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol (molecular weight of about 2,500), and the modified diol 1 are put into a reactor in a mass ratio of 10:80:5, and the temperature is raised to 130-150°C. A catalyst having a total mass of 5w‰ of carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol, and the modified diol 1 is added. After polycondensation for 4 hours in a vacuum degree of less than 0.5 mmHg, the resin is cooled to room temperature to obtain a polyester resin, and the molecular weight is determined to be about 31,000 by GPC.

[0092] Example 3

[0093] A polyester resin, the preparation process of which is as follows:

[0094] Carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol (molecular weight of about 2,500), and the modified diol 1 are put into a reactor in a mass ratio of 10:60:5, and the temperature is raised to 130-150° C. Then, a catalyst having a total mass of 3w‰ of carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol, and the modified diol is added. After polycondensation for 4 hours in a vacuum degree of less than 0.5 mmHg, the resin is cooled to room temperature to obtain a polyester resin, and the molecular weight is determined by GPC to be about 28,000.

[0095] Example 4

[0096] A polyester resin, the preparation process of which is as follows:

[0097] Carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol (molecular weight of about 2,500), and the modified diol 1 are put into a reactor in a mass ratio of 15:90:5, and the temperature is raised to 130-150°C. A catalyst having a total mass of 5w‰ of carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol, and the modified diol 1 is added. After polycondensation for 4 hours in a vacuum degree of less than 0.5 mmHg, the resin is cooled to room temperature to obtain a polyester resin, and the molecular weight is determined by GPC to be about 33,000.

[0098] Example 5

[0099] A polyester resin, the preparation process of which is as follows:

[0100] Carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol (molecular weight of about 2,500), and the modified diol 1 are put into a reactor in a mass ratio of 20:90:5, and the temperature is raised to 130-150° C. Then, a catalyst having a total mass of 5 w‰ of carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol, and the modified diol 1 is added. After polycondensation for 4 hours in a vacuum degree of less than 0.5 mmHg, the resin is cooled to room temperature to obtain a polyester resin, and the molecular weight is determined by GPC to be about 35,000.

[0101] Example 6

[0102] A polyester resin, the preparation process of which is as follows:

[0103] Carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol (molecular weight of about 2,500), and the modified diol 1 are put into a reactor in a mass ratio of 10:90:10, and the temperature is raised to 130-150° C. Then, a catalyst having a total mass of 5 w‰ of carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol, and the modified diol 1 is added. After polycondensation for 4 hours in a vacuum degree of less than 0.5 mmHg, the resin is cooled to room temperature to obtain a polyester resin, and the molecular weight is determined to be about 33,000 by GPC.

[0104] Example 7

[0105] A polyester resin, the preparation process of which is as follows:

[0106] Carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol (molecular weight of about 2,500), and the modified diol 1 are put into a reactor in a mass ratio of 10:90:20, and the temperature is raised to 130-150° C. Then, a catalyst with a total mass of 8w‰ of carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol, and the modified diol 1 is added. After polycondensation for 3 hours in a vacuum degree of less than 0.5 mmHg, the resin is cooled to room temperature to obtain a polyester resin, and the molecular weight is determined by GPC to be about 30,000.

[0107] Example 8

[0108] A polyester resin, the preparation process of which is as follows:

[0109] Carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol (molecular weight of about 2,500), and the modified diol 2 are put into a reactor in a mass ratio of 10:90:5, and the temperature is raised to 130-150°C. A catalyst having a total mass of 5w‰ of carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol and the modified diol 2 is added. After polycondensation for 4 hours in a vacuum degree of less than 0.5 mmHg, the resin is cooled to room temperature to obtain a polyester resin, and the molecular weight is determined by GPC to be about 32,000.

[0110] Example 9

[0111] A polyester resin, the preparation process of which is as follows:

[0112] Carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol (molecular weight of about 2,500), and the modified diol 3 are put into a reactor in a mass ratio of 10:90:5, and the temperature is raised to 130-150°C. A catalyst having a total mass of 5w‰ of carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol and the modified diol 3 is added. After polycondensation for 4 hours in a vacuum degree of less than 0.5 mmHg, the resin is cooled to room temperature to obtain a polyester resin, and the molecular weight is determined by GPC to be about 32,000.

[0113] Example 10

[0114] A polyester resin, the preparation process of which is as follows:

[0115] Carboxyl-terminated polybutylene succinate 2, polypropylene carbonate diol (molecular weight of about 2,500), and the modified diol 1 are put into a reactor in a mass ratio of 10:90:5, and the temperature is raised to 130-150°C. A catalyst having a total mass of 5w‰ of carboxyl-terminated polybutylene succinate 2, polypropylene carbonate diol, and the modified diol 1 is added. After polycondensation for 4 hours in a vacuum degree of less than 0.5 mmHg, the resin is cooled to room temperature to obtain a polyester resin, and the molecular weight is determined by GPC to be about 29,000.

[0116] Embodiment 11

[0117] A polyester resin, the preparation process of which is as follows:

[0118] Carboxyl-terminated polybutylene succinate 3, polypropylene carbonate diol (molecular weight of about 2,500), and the modified diol 1 are put into a reactor in a mass ratio of 10:90:5, and the temperature is raised to 130-150°C. Then, a catalyst having a total mass of 5w‰ of carboxyl-terminated polybutylene succinate 3, polypropylene carbonate diol, and the modified diol 1 is added. After polycondensation for 4 hours in a vacuum degree of less than 0.5 mmHg, the resin is cooled to room temperature to obtain a polyester resin, and the molecular weight is determined to be about 38,000 by GPC.

[0119] Example 12

[0120] A polyester resin, the preparation process of which is as follows:

[0121] Carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol (molecular weight of about 2,000), and the modified diol 1 are put into a reactor in a mass ratio of 10:90:5, and the temperature is raised to 130-150°C. A catalyst having a total mass of 5w‰ of carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol, and the modified diol 1 is added. After polycondensation for 4 hours in a vacuum degree of less than 0.5 mmHg, the resin is cooled to room temperature to obtain a polyester resin, and the molecular weight is determined by GPC to be about 30,000.

[0122] Example 13

[0123] A polyester resin, the preparation process of which is as follows:

[0124] Carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol (molecular weight of about 4,000), and the modified diol 1 are put into a reactor in a mass ratio of 10:90:5, and the temperature is raised to 130-150°C. A catalyst having a total mass of 5w‰ of carboxyl-terminated polybutylene succinate 1, polypropylene carbonate diol, and the modified diol 1 is added. After polycondensation for 4 hours in a vacuum degree of less than 0.5 mmHg, the resin is cooled to room temperature to obtain a polyester resin, and the molecular weight is determined by GPC to be about 35,000.

[0125] Example 14 to Example 26

[0126] The preparation process of polyester pressure-sensitive adhesive is as follows:

[0127] The polyester resins described in Examples 1 to 13 are respectively formulated into polyester pressure-sensitive adhesives, and the specific formulas and preparation methods are as follows:

[0128] 95 parts of polyester resin, 5 parts of epoxy soybean oil and 0.15 parts of antioxidant tris(2,4-di-tert-butylphenyl)phosphite were stirred at 130°C for 3 hours, and after cooling to room temperature, an appropriate amount of chloroform solution was added to obtain a pressure-sensitive adhesive solution with a solid content of 20 wt%;

[0129] The pressure-sensitive adhesive solution was coated on the PET film by a coating machine, and the chloroform was evaporated after being kept at 80°C for 10 minutes. The thickness of the pressure-sensitive adhesive layer of the obtained pressure-sensitive adhesive tape was about 15 μm.

[0130] Among them, the polyester pressure-sensitive adhesive used in Example 14 is the polyester pressure-sensitive adhesive described in Example 1, the polyester pressure-sensitive adhesive used in Example 15 is the polyester pressure-sensitive adhesive described in Example 2, the polyester pressure-sensitive adhesive used in Example 16 is the polyester pressure-sensitive adhesive described in Example 3, ..., the polyester pressure-sensitive adhesive used in Example 26 is the polyester pressure-sensitive adhesive described in Example 13.

[0131] Embodiment 27

[0132] The preparation process of polyester pressure-sensitive adhesive is as follows:

[0133] 97 parts of the polyester resin described in Example 1, 3 parts of epoxy soybean oil, and 0.1 parts of antioxidant tris(2,4-di-tert-butylphenyl)phosphite were stirred at 130° C. for 3 hours, and after cooling to room temperature, an appropriate amount of chloroform solution was added to obtain a degradable pressure-sensitive adhesive with a solid content of 20 wt%;

[0134] The pressure-sensitive adhesive solution was coated on the PET film by a coating machine, and the chloroform was evaporated after being kept at 80° C. for 10 minutes. The thickness of the pressure-sensitive adhesive layer of the obtained pressure-sensitive adhesive tape was about 15 μm.

[0135] Embodiment 28

[0136] The preparation process of polyester pressure-sensitive adhesive is as follows:

[0137] 99 parts of the polyester resin described in Example 1, 1 part of epoxy soybean oil, and 0.1 part of antioxidant tris(2,4-di-tert-butylphenyl)phosphite were stirred at 130° C. for 3 hours, and after cooling to room temperature, an appropriate amount of chloroform solution was added to obtain a degradable pressure-sensitive adhesive with a solid content of 20 wt%;

[0138] The pressure-sensitive adhesive solution was coated on the PET film by a coating machine, and the chloroform was evaporated after being kept at 80° C. for 10 minutes. The thickness of the pressure-sensitive adhesive layer of the obtained pressure-sensitive adhesive tape was about 15 μm.

[0139] The polyester pressure-sensitive adhesives described in Examples 14 to 28 were subjected to performance tests, and the test items and methods were as follows:

[0140] (1) Initial adhesion: Tested according to Method A in GB / T 4852-2002, with the slope inclined at 30°.

[0141] (2) 180 peel strength: tested in accordance with the provisions of GB / T 2792.

[0142] (3) Adhesion: The test was conducted in accordance with the provisions of Method A in GB / T 4851-2014. The width of the degradable tape sample was 25 mm, the length of the adhesive surface between the sample and the steel plate was (12 ± 0.5 mm), and the mass of the weight was (1000 ± 5 g).

[0143] (4) Biodegradability: Tested in accordance with the requirements of GB / T 19277.1.

[0144] The test results are shown in Table 1.

[0145] Table 1

[0146]

[0147] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation methods of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A polyester resin, characterized in that: The polyester resin is a copolymer of a carboxyl-terminated polyester, a non-crystalline carbon dioxide-based polyester diol and a modified diol, wherein the mass fraction ratio of the carboxyl-terminated polyester, the non-crystalline carbon dioxide-based polyester diol and the modified diol is: (10-30): (50-99): (2-30); wherein the structural formula of the modified diol is as shown in Formula 1, Formula 2 or Formula 3: in: R1 is a C1-12 alkyl group; R2 is a C1-12 alkyl group; R3 is a C1-12 alkyl group; R4 is H or C1-12 alkyl; R5 is a C1-12 alkyl group; the carboxyl-terminated polyester is polymerized from a C3-7 dibasic acid and a C3-7 diol, and the polyester resin is degradable.

2. The polyester resin according to claim 1, characterized in that The mass fraction of the carboxyl-terminated polyester is 10 to 25, and / or the mass fraction of the non-crystalline carbon dioxide-based polyester diol is 60 to 90, and / or the mass fraction of the modified diol is 4 to 25, and / or the molecular weight of the polyester resin is 20,000 to 60,000.

3. The polyester resin according to claim 1, characterized in that The mass fraction of the carboxyl-terminated polyester is 10 to 20, and / or the mass fraction of the non-crystalline carbon dioxide-based polyester diol is 55 to 95, and / or the mass fraction of the modified diol is 5 to 20, and / or the molecular weight of the polyester resin is 25,000 to 40,000.

4. The polyester resin according to claim 3, characterized in that The molecular weight of the polyester resin is 28,000 to 38,000.

5. The polyester resin according to claim 1, characterized in that The carboxyl-terminated polyester has a number average molecular weight of 1000 to 3000, and / or the non-crystalline carbon dioxide-based polyester diol has a number average molecular weight of 2000 to 4000.

6. The polyester resin according to claim 5, characterized in that: The carboxyl-terminated polyester is carboxyl-terminated polybutylene succinate, and its hydroxyl value is 37.4-112 mgKOH / g, and / or the non-crystalline carbon dioxide-based polyester diol is polypropylene carbonate diol.

7. A method for preparing a polyester resin according to any one of claims 1 to 6, characterized in that: The steps include: The carboxyl-terminated polyester, the non-crystalline carbon dioxide-based polyester diol and the modified diol are placed in a reaction kettle in the following mass proportions: (10-30): (50-99): (2-30), and after heating to 100-180°C, a catalyst in an amount of 1‰-2% of the total mass of the carboxyl-terminated polyester, the non-crystalline carbon dioxide-based polyester diol and the modified diol is added, vacuum polycondensation is performed, and cooling is performed to obtain the polyester-type resin.

8. The preparation method according to claim 7, characterized in that: The mass fractions of the carboxyl-terminated polyester, the non-crystalline carbon dioxide-based polyester diol and the modified diol added into the reaction kettle are (10-20): (60-90): (5-20), the temperature is raised to 130-150°C, the amount of the catalyst added is 3wt‰-8w‰ of the total mass of the carboxyl-terminated polyester, the non-crystalline carbon dioxide-based polyester diol and the modified diol, and after vacuum polycondensation for 3-4 hours within a vacuum degree of less than 0.5 mmHg, the polyester type pressure-sensitive adhesive resin is obtained by cooling to room temperature; and / or the catalyst is tetrabutyl titanate, tetraisopropyl titanate or p-toluenesulfonic acid.

9. The preparation method according to claim 7, characterized in that: The preparation of the modified diol comprises the following steps: adding an olamine compound into an organic solvent, dripping an acrylate compound under the protection of an inert gas, reacting at 10-40° C. for 1-50 hours, then performing liquid separation and extraction, removing the organic solvent, and obtaining a self-made modified diol; wherein the molar ratio of the olamine compound to the acrylate compound is (0.5-3):

1.

10. The preparation method according to claim 9, characterized in that: The alcohol amine compound is one or more of diethanolamine, 2-amino-2-methyl-1,3-propanediol, 2-amino-1,3-propanediol, and 3-amino-1,2-propanediol, and / or the acrylate compound is one or more of isooctyl acrylate, butyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, isooctyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate, and / or the organic solvent is methanol, ethanol, or dimethylformamide.

11. The preparation method according to claim 9, characterized in that: The reaction is carried out at 20-30° C. for 2 to 30 hours, and then the mixture is washed with water for more than three times and separated and extracted, and then the organic solvent is removed by distillation under reduced pressure. The molar ratio of the alcoholamine compound to the acrylate compound is (1 to 1.2):

1.

12. A polyester pressure-sensitive adhesive, characterized in that: The invention comprises the following components calculated by weight: 50 to 99 parts of the polyester resin as claimed in any one of claims 1 to 6, or the polyester resin prepared by the preparation method according to any one of claims 7 to 11; and 0.1 to 10 parts of additives.

13. The polyester pressure-sensitive adhesive according to claim 12, characterized in that: The polyester resin is 60-99 parts; the additives include 1-5 parts of plasticizer and 0.1-0.2 parts of antioxidant.

14. The polyester pressure-sensitive adhesive according to claim 12, characterized in that: The polyester resin is 80-99 parts; the additives include 1-5 parts of plasticizer and 0.1-0.2 parts of antioxidant.

15. The polyester pressure-sensitive adhesive according to claim 12, characterized in that: The polyester resin is 90-99 parts; the additives include 1-5 parts of plasticizer and 0.1-0.2 parts of antioxidant.

16. The polyester pressure-sensitive adhesive according to claim 12, characterized in that: The polyester resin is 95-99 parts; the additives include 1-5 parts of plasticizer and 0.1-0.2 parts of antioxidant.

17. The polyester pressure-sensitive adhesive according to any one of claims 13 to 16, characterized in that: The plasticizer is one or more of epoxidized soybean oil, linseed oil, castor oil, and palm oil, and / or the antioxidant is one or more of tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, di(tridecanol)thiodipropionate, and tetrakis{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate}pentaerythritol.

18. A pressure-sensitive adhesive product, comprising a substrate and a pressure-sensitive adhesive layer attached to the substrate, characterized in that: The pressure-sensitive adhesive layer comprises the polyester pressure-sensitive adhesive as described in any one of claims 12 to 17.

Images