Aqueous polyurethane roll adhesive, and preparation method and application thereof

Abstract

The application discloses a kind of water-based polyurethane roll adhesive and its preparation method and application.The water-based polyurethane roll adhesive includes the following components by weight:100 parts of water-based polyurethane dispersion, 15-35 parts of plasticizer, 5-20 parts of stabilizer aqueous solution;The water-based polyurethane dispersion includes the following raw materials, taking the total weight of solid components as 100%:5-20% of aliphatic diisocyanate, 70-90% of polyol, 1-5% of hydrophilic compound, 1-3% of chain extender, 0.007-0.035% of emulsifier.The water-based polyurethane roll adhesive of the application has good initial adhesion, good thermal storage stability and shock stability, is halogen-free, resistant to yellowing, low odor and recyclable, etc., and is mainly suitable for bonding porous substrates such as sponge mattress, and can replace existing water-based neoprene roll adhesive.

Description

Technical Field

[0001] This invention relates to a polyurethane mattress roller adhesive compound, and more particularly to a water-based polyurethane roller adhesive, its preparation method, and its application. Background Technology

[0002] With rising consumer spending power and accelerated upgrades in home furnishing products, most mattresses are discarded after 10 years of use. This not only wastes resources but also generates a large amount of waste. According to incomplete statistics, approximately 90 million mattresses are discarded annually, occupying over 70 million square meters of landfill space. However, 75% of these mattresses are recyclable. In recent years, sponge recycling has received considerable attention. Sponges are mostly made from polyisocyanates and polyester / polyether polyols. Currently, the optimal recycling technology involves high-temperature pyrolysis of the sponge to produce polyamine compounds and polyester / polyether polyols. The polyamines are then processed into polyisocyanates, which are then reused with the polyester / polyether polyols to foam and produce sponges again, achieving a complete industrial chain cycle.

[0003] Currently, water-based adhesives for mattress bonding are based on water-based chloroprene systems. Because water-based chloroprene differs significantly from polyurethane systems, the chloroprene layer in the mattress must be removed before pyrolysis and recycling; otherwise, it will affect the purification of the raw materials, which greatly hinders the pyrolysis and recycling of the foam. Furthermore, water-based chloroprene has problems such as containing halogens, yellowing, allergenicity, high energy consumption during production, and high price. The market is also looking for alternatives to water-based chloroprene. Invention patent CN 109536080A discloses a water-based roller adhesive composed of natural latex, acrylic latex, and styrene-butadiene latex, which can replace water-based chloroprene in terms of performance. However, it has a strong odor problem, making it difficult to apply to mattress products. In addition, this system differs significantly from polyurethane systems, hindering the pyrolysis and recycling of the foam. Summary of the Invention

[0004] To address the above technical problems, this invention proposes a waterborne polyurethane roller adhesive, its preparation method, and its application. The waterborne polyurethane roller adhesive of this invention features good initial adhesion, good thermal storage stability and vibration stability, is halogen-free, resistant to yellowing, has low odor, and is recyclable. It is mainly suitable for bonding porous substrates such as foam mattresses and can replace existing waterborne neoprene roller adhesives.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A waterborne polyurethane roller adhesive comprises the following components in parts by weight: 100 parts of waterborne polyurethane dispersion, 15-35 parts of plasticizer, and 5-20 parts of stabilizer aqueous solution.

[0007] The aqueous polyurethane dispersion comprises the following raw materials, based on 100% of the total weight of solid components:

[0008] Aliphatic diisocyanates 5-20%,

[0009] Polyols 70-90%,

[0010] 1-5% hydrophilic compounds

[0011] Chain extender 1-3%,

[0012] Emulsifier 0.007-0.035%.

[0013] Preferably, the solid content of the aqueous polyurethane dispersion is 41-43%.

[0014] In some preferred embodiments of the present invention, the plasticizer is one or both of dipropylene glycol dibenzoate and diethylene glycol dibenzoate.

[0015] In some preferred embodiments of the present invention, the stabilizer aqueous solution is one or more aqueous solutions selected from sodium carboxymethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, xanthan gum, guar gum and guar gum;

[0016] Preferably, the mass concentration of the stabilizer in the aqueous stabilizer solution is 1-5%.

[0017] In some preferred embodiments of the present invention, the aliphatic diisocyanate is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate;

[0018] Preferably, the polyol comprises crystalline polyester polyol and low / non-crystalline polyester polyol with a mass ratio greater than 1, and more preferably, the mass ratio of the two is (6-10):1, more preferably (7-9):1.

[0019] Preferably, the melting temperature of the crystalline polyester polyol, measured by differential scanning calorimetry according to DIN 65467 at a heating rate of 20 K / min, is in the range of 40–80 °C.

[0020] Preferably, the melting temperature of the low / amorphous polyester polyol, measured by differential scanning calorimetry at a heating rate of 20 K / min according to DIN 65467, is below 30°C.

[0021] In some preferred embodiments of the present invention, the hydrophilic compound is a hydrophilic compound containing ionic groups and / or a hydrophilic compound containing nonionic groups;

[0022] Preferably, the hydrophilic compound containing ionic groups is one or more of dimethylolpropionic acid, dimethylolbutyric acid, N-(2-aminoethyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-2-aminoethanesulfonic acid, and their soluble salts;

[0023] Preferably, the hydrophilic compound containing nonionic groups is polyethylene glycol monomethyl ether, and more preferably polyethylene glycol monomethyl ether with a number average molecular weight of 500-2000.

[0024] In some preferred embodiments of the present invention, the chain extender is one or more of ethylene glycol, 1,4-butanediol, ethylenediamine, hydroxyethyl ethylenediamine, and isophorone diamine.

[0025] In some preferred embodiments of the present invention, the emulsifier is one or more of anionic emulsifiers, nonionic emulsifiers, and anionic-nonionic emulsifiers, preferably one or more of sodium alkyl polyoxyethylene ether sulfate (e.g., Klein EPA-073), disodium sulfosuccinate ethoxyethanol monoester (e.g., Solvay DES-30), sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), and polyoxyethylene sorbitan monolaurate (e.g., Tween 20).

[0026] The present invention also provides a method for preparing waterborne polyurethane roller adhesive as described above, characterized in that the waterborne polyurethane dispersion and the stabilizer aqueous solution are first mixed and stirred for 15-30 min, then a plasticizer is added, stirred for 30-60 min, and then filtered and discharged.

[0027] Preferably, the preparation method of the aqueous polyurethane dispersion is as follows:

[0028] A dehydrated aliphatic diisocyanate, polyol, organic solvent, and optionally hydrophilic compound A are added to a reaction vessel and reacted at 80-90°C to obtain an NCO-terminated prepolymer. A chain extender and optionally hydrophilic compound B are then added for chain extension at 40-50°C. Water is then added for dispersion, the organic solvent is removed, and an emulsifier is added to obtain an aqueous polyurethane dispersion. Hydrophilic compound A is a hydrophilic compound containing nonionic groups and / or dimethylolpropionic acid and dimethylolbutyric acid; hydrophilic compound B is a hydrophilic compound containing ionic groups other than dimethylolpropionic acid and dimethylolbutyric acid; at least one of hydrophilic compound A and hydrophilic compound B is added to the system.

[0029] When hydrophilic compound A is selected from dimethylolpropionic acid or dimethylolbutyric acid, it is known in the art that a salt-forming agent needs to be added during the chain extension reaction to neutralize the hydrophilic compound and form a salt. Preferably, the salt-forming agent is triethylamine (TEA).

[0030] Preferably, the organic solvent is selected from one or more of acetone and butanone;

[0031] Preferably, the solid content of the aqueous polyurethane dispersion is 41-43%.

[0032] The present invention also provides an application of the waterborne polyurethane roller adhesive as described above or the waterborne polyurethane roller adhesive prepared by the method described above in a foam mattress.

[0033] In the aqueous polyurethane roller coating formulation of this invention, the aqueous polyurethane dispersion contains a very small amount of emulsifier to adjust the low emulsion stability. Simultaneously, the plasticizer, while lowering the roller coating activation temperature and increasing the solid viscosity, further reduces emulsion stability. Finally, a stabilizer is added to adjust the roller coating stability and simultaneously improve the initial tack under light pressure. The coordinated combination of these three components adjusts the emulsion stability to a metastable state. In this state, the roller coating, when applied to the sponge, immediately breaks down the emulsion to form a film and achieves adhesion upon pressing. The roller coating also exhibits good vibration stability, thermal storage stability, and roller coating stability, meeting the requirements for normal transportation and use. Furthermore, both the aqueous polyurethane roller coating and the sponge in this invention are polyurethane systems, allowing them to form a single material with the sponge. The adhesive layer can be decomposed and recycled without removal. In addition, aqueous polyurethane has advantages such as being halogen-free, resistant to yellowing, and having a low odor, making it a perfect substitute for aqueous chloroprene systems. Detailed Implementation

[0034] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0035] In the following embodiments of the present invention, the raw materials and reagents used, unless otherwise specified, can be obtained through conventional commercial channels. The main raw material information is as follows:

[0036] Crystalline polyester polyol WHP 104: Poly(1,4-butanediol adipate), molecular weight 1000, melting point 30-50℃, Wanhua Chemical.

[0037] Crystalline polyester polyol WHP 204: Poly(1,4-butanediol adipate), molecular weight 2000, melting point 35-55℃, Wanhua Chemical.

[0038] Crystalline polyester polyol WHP 304: Poly(1,4-butanediol adipate), molecular weight 3000, melting point 40-60℃, Wanhua Chemical.

[0039] Crystalline polyester polyol WHP 404: Poly(1,4-butanediol adipate), molecular weight 4000, melting point 40-60℃, Wanhua Chemical.

[0040] Low / Amorphous Polyester Polyol WHP 2056: Adipic acid / hexanediol / neopentyl glycol copolymer, molecular weight 2000, melting point <25℃, Wanhua Chemical

[0041] Low / Amorphous Polyester Polyol WHP 2027: Ethylene glycol / diethylene glycol / adipic acid copolymer, molecular weight 2000, melting point <25℃, Wanhua Chemical

[0042] Low / Amorphous Polyester Polyol WHP 4024: Ethylene glycol / Butanediol / Adipic acid copolymer, molecular weight 4000, melting point <25℃, Wanhua Chemical

[0043] Low / Amorphous Polyester Polyol WHP 1045: Butylene glycol / neopentyl glycol / adipic acid copolymer, molecular weight 1000, melting point <25℃, Wanhua Chemical

[0044] MPEG-520, MPEG-1200, and MPEG-2000: Monofunctional polyvinyl oxide ethers with number-average molecular weights of 520, 1200, and 2000 respectively, and a functionality of 1. (Hai'an Petrochemical)

[0045] DMPA: Dimethylolpropionic acid, Bailingwei

[0046] IPDI: Isophorone diisocyanate, Wanhua Chemical

[0047] HDI: 1,6-hexamethylene diisocyanate, Wanhua Chemical

[0048] HMDI: Dicyclohexylmethane diisocyanate, Wanhua Chemical

[0049] A95: Aqueous solution of sodium N-(2-aminoethyl)-2-aminoethanesulfonate, Evonik, Germany.

[0050] EDA-OH: Hydroxyethyl ethylenediamine, BASF, Germany.

[0051] EDA: Ethylenediamine, Sinopharm Group

[0052] TEA: Triethylamine, Sinopharm Group

[0053] IPDA: Isophorone diamine, Wanhua Chemical

[0054] FLEX-80: A 4:1 mixture of dipropylene glycol dibenzoate and diethylene glycol dibenzoate, Wuhan Yikede

[0055] FLEX-314: Diethylene glycol dibenzoate, Wuhan Yikede

[0056] FLEX-80: Dipropylene glycol dibenzoate, Wuhan Yikede

[0057] Guinea gum, guar gum, hydroxypropyl methylcellulose: Xinrui Biotechnology

[0058] CMC: Sodium carboxymethyl cellulose, Shandong Yangzi Biotechnology Co., Ltd.

[0059] SDS, SDBS, TW20: Sinopharm Group

[0060] EPA-073; Solvay

[0061] Note: In the following preparation examples, the raw materials for the waterborne polyurethane dispersions were all dehydrated before being mixed and reacted.

[0062] Preparation Example 1: Preparation of Waterborne Polyurethane Dispersion 1

[0063] 200g WHP 204, 25g WHP 2056, 26g HDI, 1.2g MPEG-1200, and 25g acetone were added to a 2L four-necked round-bottom flask equipped with a nitrogen inlet and outlet. The mixture was reacted at 80°C until the NCO content no longer decreased, yielding an NCO-terminated prepolymer. This prepolymer was dissolved in 400g acetone and cooled to 40°C. 35g of an aqueous solution containing 2.7g IPDA and 3g A95 was added to the prepolymer solution, and the mixture was stirred vigorously for 20 minutes. Then, 293g of water was added, and after thorough dispersion, the acetone was removed by distillation. Finally, 0.018g of emulsifier SDS was added to obtain aqueous polyurethane dispersion 1 with a solid content of 42%.

[0064] Preparation Example 2: Preparation of Waterborne Polyurethane Dispersion 2

[0065] 200g WHP 304, 32g WHP 2027, 40g HMDI, and 25g acetone were added to a 2L four-necked round-bottom flask equipped with a nitrogen inlet and outlet. The reaction was carried out at 85°C until the NCO content no longer decreased, yielding an NCO-terminated prepolymer. This prepolymer was dissolved in 400g acetone and cooled to 45°C. 35g of an aqueous solution containing 3.5g IPDA, 2.5g A95, and 2.5g EDA-OH was added to the prepolymer solution, and the mixture was stirred vigorously for 20 minutes. Then, 324g of water was added, and after thorough dispersion, the acetone was removed by distillation. Finally, 0.057g of emulsifier SDBS was added to obtain aqueous polyurethane dispersion 2, and the solid content was adjusted to 42%.

[0066] Preparation Example 3: Preparation of Waterborne Polyurethane Dispersion 3

[0067] 200g WHP 404, 20g WHP 4024, 17g HMDI, 3g MPEG-520, and 25g acetone were added to a 2L four-necked round-bottom flask equipped with a nitrogen inlet and outlet. The mixture was reacted at 90℃ until the NCO content no longer decreased, yielding an NCO-terminated prepolymer. This prepolymer was dissolved in 400g acetone and cooled to 50℃. 35g of an aqueous solution containing 2.6g IPDA, 0.4g EDA, and 0.5g A95 was added to the prepolymer solution, and the mixture was stirred vigorously for 20 minutes. Then, 290g of water was added, and after thorough dispersion, the acetone was removed by distillation. Finally, 0.02g of emulsifier SDS and 0.02g of emulsifier EPA-073 were added to obtain aqueous polyurethane dispersion 3, with the solid content adjusted to 42%.

[0068] Preparation Example 4: Preparation of Waterborne Polyurethane Dispersion 2

[0069] 140g WHP 104, 16g WHP 1045, 22g HDI, 25g IPDI, 3g DMPA, 8g MPEG-1200, and 25g acetone were added to a 2L four-necked round-bottom flask equipped with a nitrogen inlet and outlet. The mixture was reacted at 85°C until the NCO content no longer decreased, yielding an NCO-terminated prepolymer. This prepolymer was dissolved in 400g acetone and cooled to 40°C. 2.3g TEA was added to form a salt for 5 minutes. 35g of an aqueous solution containing 5g IPDA and 1.3g EDA-OH was added to the prepolymer solution, and the mixture was stirred vigorously for 20 minutes. Then, 243g of water was added, and after thorough dispersion, the acetone was removed by distillation. Finally, 0.057g of emulsifier TW20 and 0.02g of emulsifier EPA-073 were added to obtain an aqueous polyurethane dispersion 4, with the solid content adjusted to 42%.

[0070] Preparation Example 5: Preparation of Waterborne Polyurethane Dispersion 5

[0071] 210g WHP 204, 28g WHP 2056, 50g HDI, 0.5g DMBA, 3g MPEG-1200, and 25g acetone were added to a 2L four-necked round-bottom flask equipped with a nitrogen inlet and outlet. The mixture was reacted at 85°C until the NCO content no longer decreased, yielding an NCO-terminated prepolymer. This prepolymer was dissolved in 400g acetone and cooled to 40°C. 0.35g TEA was added to form a salt for 5 minutes. 35g of an aqueous solution containing 1g A95, 0.2g EDA, and 3g EDA-OH was added to the prepolymer solution, and the mixture was stirred vigorously for 20 minutes. Then, 331g of water was added, and after thorough dispersion, the acetone was removed by distillation. Finally, 0.074g of emulsifier SDS was added to obtain aqueous polyurethane dispersion 5, with the solid content adjusted to 42%.

[0072] Comparative Preparation Example 1: Aqueous Polyurethane Dispersion 6

[0073] Aqueous polyurethane dispersions were prepared using essentially the same method as in Preparation Example 1, except that no emulsifier SDS was added after the reaction, resulting in an emulsified aqueous polyurethane dispersion 6.

[0074] Comparative Preparation Example 2: Aqueous Polyurethane Dispersion 7

[0075] The aqueous polyurethane dispersion was prepared using a method essentially the same as that used in Preparation Example 1, except that the 0.018 g emulsifier SDS added after the reaction was replaced with 0.15 g emulsifier SDS, resulting in aqueous polyurethane dispersion 7.

[0076]

Example 1

[0077] 1,100 parts of waterborne polyurethane dispersion

[0078] FLEX-80 25 servings

[0079] 8 parts of 1.2wt% guar gum aqueous solution.

[0080] According to the above weight proportions, the aqueous polyurethane dispersion 1 is first mixed with the guar gum aqueous solution and stirred for 15 minutes, then the plasticizer FLEX-80 is added and stirred for 45 minutes, and then filtered out.

[0081]

Example 2

[0082] 2 100 parts of waterborne polyurethane dispersion

[0083] FLEX-80 35 servings

[0084] 20 parts of 1 wt% hydroxypropyl methylcellulose aqueous solution.

[0085] According to the above weight proportions, the aqueous polyurethane dispersion 2 is first mixed with the aqueous hydroxypropyl methylcellulose solution and stirred for 15 minutes, then the plasticizer FLEX-80 is added and stirred for 45 minutes, and then filtered out.

[0086]

Example 3

[0087] 3 100 parts of waterborne polyurethane dispersion

[0088] FLEX-314 20 copies

[0089] 5 parts of 2wt% sodium carboxymethyl cellulose aqueous solution.

[0090] According to the above weight proportions, the aqueous polyurethane dispersion 3 is first mixed with the carboxymethyl cellulose aqueous solution and stirred for 15 minutes, then the plasticizer FLEX-314 is added and stirred for 45 minutes, and then filtered out.

[0091]

Example 4

[0092] 4,100 parts of waterborne polyurethane dispersion

[0093] FLEX-342, 15 servings

[0094] 5 parts of 5 wt% xanthan gum aqueous solution.

[0095] According to the above weight proportions, the aqueous polyurethane dispersion 1 is first mixed with xanthan gum aqueous solution and stirred for 15 minutes, then the plasticizer FLEX-342 is added and stirred for 45 minutes, and then filtered out.

[0096]

Example 5

[0097] 5,100 parts of waterborne polyurethane dispersion

[0098] FLEX-80 (30 servings)

[0099] 15 parts of 2.5wt% guar gum aqueous solution.

[0100] According to the above weight proportions, the aqueous polyurethane dispersion 1 is first mixed with guar gum aqueous solution and stirred for 15 minutes, then the plasticizer FLEX-80 is added and stirred for 45 minutes, and then filtered out.

[0101]

Comparative Example 1

[0102] The waterborne polyurethane roller adhesive was prepared according to essentially the same formulation and method as in Example 1, except that waterborne polyurethane dispersion 1 was replaced with an equal mass of waterborne polyurethane dispersion 6.

[0103]

Comparative Example 2

[0104] The waterborne polyurethane roller adhesive was prepared according to essentially the same formulation and method as in Example 1, except that waterborne polyurethane dispersion 1 was replaced with an equal mass of waterborne polyurethane dispersion 7.

[0105]

Comparative Example 3

[0106] The waterborne polyurethane roller adhesive was prepared according to the same formulation and method as in Example 1, except that no guar gum aqueous solution was added during the preparation of the finished adhesive.

[0107] Test substrates and methods for waterborne polyurethane roller adhesive:

[0108] Sponge A: Size: 15*10*3cm; Density: 35D

[0109] Sponge B: Size: 15*10*3cm; Density: 50D

[0110] 1. Initial tack test under light pressure: Apply water-based polyurethane roller adhesive to the surface of sponge A using a roller coating machine, controlling the application rate at 50g / m². 2 Place the sponge A with the adhesive side down on the surface of the sponge B. Press a 300g weight on the surface of the sponge A for 5 seconds. Remove the weight and lift the sponge A to observe whether it can lift the sponge B. If it can, shake it back and forth and record the number of times it takes for the sponge B to be shaken down. The more times it is shaken down, the stronger the initial adhesion is.

[0111] 2. Initial Tack Test under Heavy Pressure: Water-based polyurethane roller coating is applied to the surface of sponge A using a roller coating machine, with the application rate controlled at 50g / m². 2 Place sponge A with the adhesive side down on the surface of sponge B, press a 3000g weight onto the surface of sponge A for 5 seconds, remove the weight, tear the two sponges apart, and score the tearing force (5 points maximum, score ≥ 3.5 is acceptable), the greater the force, the higher the score.

[0112] 3. Heat storage viscosity stability: Place the water-based polyurethane roller adhesive at 50℃ for 14 days and record the viscosity retention rate. Viscosity retention rate = viscosity after heat storage / initial viscosity.

[0113] 4. Shaking stability: Take 300ml of water-based polyurethane roller adhesive and place it in a 500ml straight bottle and place it in a water bath shaker. Shake for 24 hours at 25℃*60RMP / min. Filter the residue through a 100-mesh filter to test its content.

[0114] 5. Roller coating stability: Pour 5 kg of water-based polyurethane roller coating into the middle of the roller coating machine, leave the roller empty for 45 minutes, and observe whether the roller produces slag; if no slag is produced, it is considered excellent, and if slag is produced, it is considered poor.

[0115] Table 1. Test Results of Waterborne Polyurethane Roller Adhesive

[0116]

[0117] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A water-based polyurethane roller adhesive, characterized in that, It includes the following components in parts by weight: 100 parts of aqueous polyurethane dispersion, 15-35 parts of plasticizer, and 5-20 parts of stabilizer aqueous solution; The aqueous polyurethane dispersion comprises the following raw materials, based on 100% of the total weight of solid components: Aliphatic diisocyanates 5-20%, Polyols 70-90%, 1-5% hydrophilic compounds Chain extender 1-3%, Emulsifier 0.007-0.035%; The plasticizer is one or both of dipropylene glycol dibenzoate and diethylene glycol dibenzoate; The stabilizer aqueous solution is one or more of the following: sodium carboxymethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, xanthan gum, guar gum, and guar gum. The mass concentration of the stabilizer in the aqueous stabilizer solution is 1-5%; The hydrophilic compound is a hydrophilic compound containing ionic groups and / or a hydrophilic compound containing nonionic groups; The emulsifier is one or more of the following: sodium isotridecyl sulfate, sodium alkyl polyoxyethylene ether sulfate, disodium sulfosuccinate ethoxyethanol monoester, sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), and polyoxyethylene sorbitan monolaurate.

2. The waterborne polyurethane roller adhesive according to claim 1, characterized in that, The aliphatic diisocyanate is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate.

3. The waterborne polyurethane roller adhesive according to claim 2, characterized in that, The polyols include crystalline polyester polyols with a mass ratio greater than 1 and low / non-crystalline polyester polyols.

4. The waterborne polyurethane roller adhesive according to claim 3, characterized in that, The mass ratio of the crystalline polyester polyol to the low / non-crystalline polyester polyol is (6-10):

1.

5. The waterborne polyurethane roller adhesive according to claim 4, characterized in that, The mass ratio of the crystalline polyester polyol to the low / non-crystalline polyester polyol is (7-9):

1.

6. The waterborne polyurethane roller adhesive according to any one of claims 1-5, characterized in that, The hydrophilic compound containing ionic groups is one or more of dimethylolpropionic acid, dimethylolbutyric acid, N-(2-aminoethyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-2-aminoethanesulfonic acid, and their soluble salts.

7. The waterborne polyurethane roller adhesive according to claim 6, characterized in that, The hydrophilic compound containing nonionic groups is polyethylene glycol monomethyl ether.

8. The waterborne polyurethane roller adhesive according to claim 7, characterized in that, The hydrophilic compound containing nonionic groups is polyethylene glycol monomethyl ether with a number average molecular weight of 500-2000.

9. The waterborne polyurethane roller adhesive according to any one of claims 1-5, characterized in that, The chain extender is one or more of ethylene glycol, 1,4-butanediol, ethylenediamine, hydroxyethyl ethylenediamine, and isophorone diamine.

10. A method for preparing an aqueous polyurethane roller adhesive as described in any one of claims 1-9, characterized in that, Mix the aqueous polyurethane dispersion with the stabilizer aqueous solution for 15-30 minutes, then add the plasticizer and stir for 30-60 minutes. Filter the mixture before discharging.

11. The method for preparing waterborne polyurethane roller adhesive according to claim 10, characterized in that, The preparation method of the aqueous polyurethane dispersion is as follows: A dehydrated aliphatic diisocyanate, polyol, organic solvent, and optionally hydrophilic compound A are added to a reaction vessel and reacted at 80-90°C to obtain an NCO-terminated prepolymer. A chain extender and optionally hydrophilic compound B are then added for chain extension at 40-50°C. Water is then added for dispersion, the organic solvent is removed, and an emulsifier is added to obtain an aqueous polyurethane dispersion. Hydrophilic compound A is selected from hydrophilic compounds containing nonionic groups and / or dimethylolpropionic acid and dimethylolbutyric acid; hydrophilic compound B is a hydrophilic compound containing ionic groups other than dimethylolpropionic acid and dimethylolbutyric acid; at least one of hydrophilic compound A and hydrophilic compound B is added to the system.

12. The method for preparing waterborne polyurethane roller adhesive according to claim 11, characterized in that, The organic solvent is selected from one or more of acetone and butanone.

13. The method for preparing waterborne polyurethane roller adhesive according to claim 11, characterized in that, The solid content of the aqueous polyurethane dispersion is 41-43%.

14. The use of a waterborne polyurethane roller adhesive as described in any one of claims 1-9 or a waterborne polyurethane roller adhesive prepared by the method described in any one of claims 10-13 in a foam mattress.

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