A high-performance moisture-curing polyurethane hot melt adhesive and its preparation method

Abstract

This invention belongs to the field of polymer materials technology, and discloses a high-performance moisture-curing polyurethane hot melt adhesive and its preparation method. The high-performance moisture-curing polyurethane hot melt adhesive is prepared from raw materials comprising the following components by weight: 40-60 parts crystalline polyester polyol, 10-40 parts liquid polyester polyol, 10-40 parts polycarbonate diol, 40-60 parts polyether polyol, 40-60 parts thermoplastic resin, 0.6-1 parts diol, 32-45 parts isocyanate, 1-3 parts adhesion promoter, 0.1-0.3 parts catalyst, and 1-2 parts antioxidant; the polycarbonate diol is prepared from 1,6-hexanediol, 2-methyl-2-propyl-1,3-propanediol, and dimethyl carbonate. This polyurethane hot melt adhesive exhibits high bonding strength to ink-coated glass and ABS, excellent aging resistance, and excellent flexibility, effectively absorbing interfacial stress generated by alternating hot and cold temperatures, preventing delamination or cracking.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a high-performance moisture-curing polyurethane hot melt adhesive and its preparation method. Background Technology

[0002] Moisture-curing polyurethane hot melt adhesives, as a single-component, solvent-free, environmentally friendly adhesive, are widely used in electronics, wood processing, automotive manufacturing, textile composites, and food packaging due to their excellent bonding performance and ease of application. Especially in the electrical appliance sector, the assembly of products such as range hoods, smart refrigerator display panels, and dishwasher touchscreens often involves bonding dissimilar materials—ink-coated glass and acrylonitrile-butadiene-styrene copolymer (ABS) plastic parts. This application scenario places extremely stringent comprehensive performance requirements on the adhesive: on the one hand, the decorative ink layer on the glass surface is mostly a low surface energy material, and its coefficient of thermal expansion and polarity differ greatly from ABS plastic, requiring the adhesive to have sufficiently high initial bond strength and excellent wetting and spreading ability; on the other hand, electrical appliances experience frequent temperature changes, humid environments, and mechanical vibrations during long-term use, requiring the adhesive layer to not only have high final bond strength but also excellent flexibility and high elongation at break to absorb interfacial stress generated by alternating hot and cold temperatures and prevent delamination or cracking. Meanwhile, the trend towards high-end and long-life modern electrical appliances has placed higher demands on the long-term durability performance of adhesives, such as resistance to damp heat aging and resistance to thermal shock.

[0003] In existing technologies, such as Chinese patent CN121450280A, the surface tension of a system is reduced by adding a single-hydroxyl fluorinated monomer with a specific structure to improve the adhesion and corrosion resistance of low surface energy ink layers. However, fluorinated monomers are extremely difficult to degrade in the natural environment, exhibiting bioaccumulation and potential ecotoxicity, and facing increasingly stringent environmental regulations. Introducing such components into consumer products like electrical appliances not only increases compliance risks but also contradicts the industry trend of green manufacturing.

[0004] Therefore, given the specific needs of bonding ink glass to ABS in the electrical appliance industry, there is an urgent need to develop a new moisture-curing polyurethane hot melt adhesive that does not use restricted fluorine-containing substances and can achieve high bonding strength, high elongation at break, and excellent aging resistance. This would overcome the environmental compliance risks and performance shortcomings of existing technologies and meet the comprehensive requirements of high-end electrical appliance manufacturing for reliability, durability, and environmental protection. Summary of the Invention

[0005] The purpose of this invention is to provide a high-performance moisture-curing polyurethane hot melt adhesive and its preparation method. This high-performance moisture-curing polyurethane hot melt adhesive has excellent properties such as high bonding strength, flexibility, aging resistance and hydrolysis resistance.

[0006] The following technical solutions are used to achieve the above objectives.

[0007] This invention provides a high-performance moisture-curing polyurethane hot melt adhesive, which is prepared from raw materials comprising the following components in parts by weight:

[0008] 40-60 parts of crystalline polyester polyol

[0009] 10-40 parts of liquid polyester polyol

[0010] 10-40 parts of polycarbonate diol

[0011] 40-60 parts of polyether polyol

[0012] 40-60 parts of thermoplastic resin

[0013] 0.6-1 part of diol

[0014] 32-45 parts of isocyanate

[0015] 1-3 parts of adhesion promoter

[0016] Catalyst 0.1-0.3 parts

[0017] 1-2 parts antioxidant;

[0018] The polycarbonate diol is prepared from 1,6-hexanediol, 2-methyl-2-propyl-1,3-propanediol and dimethyl carbonate.

[0019] In some embodiments, the molar ratio of 1,6-hexanediol, 2-methyl-2-propyl-1,3-propanediol and dimethyl carbonate is 2~4:2~4:3~5, preferably 3:3~4:4~5, and more preferably 3:3~3.2:4~4.2.

[0020] In some embodiments, the method for preparing the polycarbonate diol includes the following steps:

[0021] S1. Mix 1,6-hexanediol, 2-methyl-2-propyl-1,3-propanediol and dimethyl carbonate and react at 120℃~140℃ for 4h~6h;

[0022] S2. Increase the temperature to 200℃~230℃, evacuate to -0.04MPa~-0.07MPa, and continue the reaction for 1h~2h;

[0023] S3. Continue evacuating to -0.095MPa to -0.1MPa and continue the reaction for 1.5h to 2h;

[0024] S4. After the reaction is complete, the material is discharged when the temperature drops below 100°C under nitrogen atmosphere protection to obtain the polycarbonate diol.

[0025] In some embodiments, the material is prepared from raw materials comprising the following components, by weight:

[0026] 55-60 parts of crystalline polyester polyol

[0027] 10-15 parts of liquid polyester polyol

[0028] 35-40 parts of polycarbonate diol

[0029] 50-55 parts of polyether polyol

[0030] 45-50 parts of thermoplastic resin

[0031] 0.6-1 part of diol

[0032] 40-45 parts of isocyanate

[0033] 2-3 parts of adhesion promoter

[0034] Catalyst 0.1-0.3 parts

[0035] 1-2 parts antioxidant.

[0036] In some embodiments, the adhesion promoter is at least one of N-aminoethyl-γ-aminopropyltrimethoxysilane, N-n-butyl-3-aminopropyl-trimethoxysilane, di(3-trimethoxysilylpropyl)amine, and 3-mercaptopropyltrimethoxysilane, preferably N-aminoethyl-γ-aminopropyltrimethoxysilane.

[0037] In some embodiments, the diol is at least one selected from 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, and 1,3-propanediol, preferably 1,3-propanediol.

[0038] In some embodiments, the hydroxyl value of the crystalline polyester polyol is 20mKOH / g to 60mKOH / g, preferably 25mKOH / g to 40mKOH / g;

[0039] Preferably, the crystalline polyester polyol is prepared by reacting a diol and a diacid; wherein the diacid is one or more of terephthalic acid, isophthalic acid, phthalic acid, adipic acid, sebacic acid, and dodecanoic acid; and the diol is one or more of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and neopentyl glycol.

[0040] In some embodiments, the polyether polyol is one or more of polypropylene glycol and polytetramethylene ether glycol with a number average molecular weight of 1000-3000, preferably polypropylene glycol with a number average molecular weight of 1800-2200.

[0041] In some embodiments, the thermoplastic resin is an acrylic resin with a number average molecular weight of 30,000-40,000;

[0042] And / or, the isocyanate is diphenylmethane-4,4'-diisocyanate;

[0043] And / or, the catalyst is one or more of dibutyltin dilaurate, stannous octoate, dimorpholino diethyl ether, and triethylamine;

[0044] And / or, the antioxidant is one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris[2,4-di-tert-butylphenyl]phosphite, octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 2,6-di-tert-butyl-4-methylphenol.

[0045] The present invention also provides a method for preparing the high-performance moisture-curing polyurethane hot melt adhesive as described above, comprising the following steps:

[0046] (1) Mix crystalline polyester polyol, liquid polyester polyol, polycarbonate diol, polyether polyol and thermoplastic resin, and vacuum dehydrate at 110℃~130℃ for 1.5h-3h;

[0047] (2) Add isocyanate and react at 90℃~130℃ for 1h~3h under nitrogen protection;

[0048] (3) Add diol and react at 90℃~130℃ for 0.5h-1h under nitrogen protection;

[0049] (4) Add adhesive accelerator, catalyst and antioxidant in sequence, and continue to react at 90℃~120℃ for 0.5h-1h under nitrogen atmosphere protection. Finally, degas under vacuum at 110℃~120℃ to obtain the wet curing polyurethane hot melt adhesive.

[0050] In this invention, polycarbonate diol is prepared by reacting specific 1,6-hexanediol, 2-methyl-2-propyl-1,3-propanediol, and dimethyl carbonate in appropriate proportions. The prepared polycarbonate diol is then used in combination with specific diols, specific adhesion promoters, and other components in appropriate amounts. This allows the synthesized polyurethane hot melt adhesive to not only have high bonding strength to ink glass and ABS, but also excellent aging resistance and excellent flexibility. It can effectively absorb interfacial stress generated by alternating hot and cold temperatures, preventing delamination or cracking. Detailed Implementation

[0051] To facilitate understanding of the present invention, a more complete description will be provided below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0052] Unless otherwise specified, experimental methods in the following examples are generally performed under standard conditions or as recommended by the manufacturer. All commonly used chemical reagents used in the examples are commercially available products.

[0053] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this invention includes any and all combinations of one or more of the associated listed items.

[0054] Example 1

[0055] The high-performance moisture-curing polyurethane hot melt adhesive of this embodiment is prepared from the following components in parts by weight:

[0056] 40 parts of crystalline polyester polyol (Evonik, Dynacoll® 7360), 25 parts of liquid polyester polyol (Asahikawa, CTP-244), 20 parts of polycarbonate diol, 48 parts of polypropylene glycol with a number average molecular weight of 2000, 46 parts of acrylic resin with a number average molecular weight of 30000, 38 parts of isocyanate (diphenylmethane-4,4'-diisocyanate (CAS No. 101-68-8)), 0.6 parts of 1,4-butanediol, 1 part of adhesive promoter di(3-trimethoxysilylpropyl)amine, 0.2 parts of catalyst dimorpholino diethyl ether, and 1 part of antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0057] The preparation method of polycarbonate diol in this embodiment is as follows:

[0058] (1) 1,6-hexanediol, 2-methyl-2-propyl-1,3-propanediol and dimethyl carbonate were added to a four-necked flask in a molar ratio of 3:3:4 and reacted at 130°C for 4 hours.

[0059] (2) Increase the temperature to 200-230℃, evacuate to -0.05MPa, and continue the reaction for 1 hour; continue evacuating to -0.095~-0.1MPa, and react at 200-230℃ for 1.5 hours; under nitrogen atmosphere protection, cool down to below 100℃ and discharge to obtain polycarbonate diol.

[0060] The preparation method of the high-performance moisture-curing polyurethane hot melt adhesive in this embodiment includes the following steps:

[0061] 1. According to the above-mentioned parts by weight of raw materials, crystalline polyester polyol, liquid polyester polyol, polycarbonate diol, polypropylene glycol, and acrylic resin are added to the reaction vessel, heated to 110°C, and vacuum dehydrated for 3 hours under stirring, with a vacuum degree of -0.095MPa.

[0062] 2. Purge with nitrogen to break the vacuum, add isocyanate, and react at 90°C for 3 hours under nitrogen protection.

[0063] 3. Add 1,4-butanediol and react at 90°C for 1 hour under nitrogen protection.

[0064] 4. Add adhesion promoter, catalyst and antioxidant, and continue stirring at 100°C for 0.5 hours.

[0065] 5. Heat to 125℃, vacuum degas, and discharge to obtain the high-performance moisture-curing polyurethane hot melt adhesive.

[0066] Example 2

[0067] The high-performance moisture-curing polyurethane hot melt adhesive of this embodiment is prepared from the following components in parts by weight:

[0068] 48 parts of crystalline polyester polyol (Evonik, Dynacoll® 7360), 15 parts of liquid polyester polyol (Asahikawa, CTP-244), 30 parts of polycarbonate diol, 40 parts of polypropylene glycol with a number average molecular weight of 2000, 40 parts of acrylic resin with a number average molecular weight of 30000, 32 parts of isocyanate (diphenylmethane-4,4'-diisocyanate (CAS No. 101-68-8)), 0.8 parts of 1,6-hexanediol, 2 parts of adhesion promoter N-n-butyl-3-aminopropyl-trimethoxysilane, 0.3 parts of catalyst dibutyltin dilaurate, and 2 parts of antioxidant tris[2,4-di-tert-butylphenyl]phosphite.

[0069] The preparation method of polycarbonate diol in this embodiment is the same as that in Example 1.

[0070] The preparation method of the high-performance moisture-curing polyurethane hot melt adhesive in this embodiment includes the following steps:

[0071] 1. According to the above-mentioned parts by weight of raw materials, crystalline polyester polyol, liquid polyester polyol, polycarbonate diol, polypropylene glycol, and acrylic resin are added to the reaction vessel, heated to 120°C, and vacuum dehydrated for 2 hours under stirring, with a vacuum degree of -0.095MPa.

[0072] 2. Purge with nitrogen to break the vacuum, add isocyanate, and react at 110°C for 2 hours under nitrogen protection.

[0073] 3. Add 1,6-hexanediol and react at 110°C for 1 hour under nitrogen protection.

[0074] 4. Add adhesion promoter, catalyst and antioxidant, and continue stirring at 105°C for 0.5 hours.

[0075] 5. Heat to 120℃, degas under vacuum, and discharge to obtain the high-performance moisture-curing polyurethane hot melt adhesive.

[0076] Example 3

[0077] The high-performance moisture-curing polyurethane hot melt adhesive of this embodiment is prepared from the following components in parts by weight:

[0078] 60 parts of crystalline polyester polyol (Evonik, Dynacoll® 7360), 10 parts of liquid polyester polyol (Asahikawa, CTP-244), 40 parts of polycarbonate diol, 52 parts of polypropylene glycol with a number average molecular weight of 2000, 48 parts of acrylic resin with a number average molecular weight of 30000, 45 parts of isocyanate (diphenylmethane-4,4'-diisocyanate (CAS No. 101-68-8)), 1 part of 1,3-propanediol, 3 parts of adhesion promoter N-aminoethyl-γ-aminopropyltrimethoxysilane, 0.2 parts of catalyst stannous octoate, and 2 parts of antioxidant β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester.

[0079] The preparation method of polycarbonate diol in this embodiment is the same as that in Example 1.

[0080] The preparation method of the moisture-curing polyurethane hot melt adhesive in this embodiment includes the following steps:

[0081] 1. According to the above-mentioned parts by weight of raw materials, crystalline polyester polyol, liquid polyester polyol, polycarbonate diol, polypropylene glycol, and acrylic resin are added to the reaction vessel, heated to 130°C, and vacuum dehydrated for 1.5 hours with stirring, and the vacuum degree is -0.095MPa.

[0082] 2. Purge with nitrogen to break the vacuum, add isocyanate, and react at 130°C for 1 hour under nitrogen protection.

[0083] 3. Add 1,3-propanediol and react at 130°C for 0.5 hours under a nitrogen atmosphere.

[0084] 4. Add adhesion promoter, catalyst and antioxidant, and continue stirring at 110°C for 0.5 hours.

[0085] 5. Heat to 110℃, degas under vacuum, and discharge to obtain the high-performance moisture-curing polyurethane hot melt adhesive.

[0086] Example 4

[0087] The high-performance moisture-curing polyurethane hot melt adhesive of this embodiment is prepared from the following components in parts by weight:

[0088] 46 parts of crystalline polyester polyol (Evonik, Dynacoll® 7360), 15 parts of liquid polyester polyol (Asahikawa, CTP-244), 25 parts of polycarbonate glycol, 50 parts of polypropylene glycol with a number average molecular weight of 2000, 60 parts of acrylic resin with a number average molecular weight of 30000, 42 parts of isocyanate (diphenylmethane-4,4'-diisocyanate (CAS No. 101-68-8)), 0.6 parts of neopentyl glycol, 2 parts of adhesive promoter 3-mercaptopropyltrimethoxysilane, 0.1 parts of catalyst triethylamine, and 1 part of antioxidant 2,6-di-tert-butyl-4-methylphenol.

[0089] The preparation method of polycarbonate diol in this embodiment is the same as that in Example 1.

[0090] The preparation method of the high-performance moisture-curing polyurethane hot melt adhesive in this embodiment includes the following steps:

[0091] 1. According to the above-mentioned parts by weight of raw materials, crystalline polyester polyol, liquid polyester polyol, polycarbonate diol, polypropylene glycol, and acrylic resin are added to the reaction vessel, heated to 120°C, and vacuum dehydrated for 1.5 hours with stirring, and the vacuum degree is -0.095MPa.

[0092] 2. Purge with nitrogen to break the vacuum, add isocyanate, and react at 120°C for 1.5 hours under nitrogen protection.

[0093] 3. Add neopentyl glycol and react at 120°C for 0.5 hours under nitrogen protection.

[0094] 4. Add adhesion promoter, catalyst and antioxidant, and continue stirring at 110°C for 0.5 hours.

[0095] 5. Heat to 110℃, degas under vacuum, and discharge to obtain the high-performance moisture-curing polyurethane hot melt adhesive.

[0096] Example 5

[0097] The high-performance moisture-curing polyurethane hot melt adhesive of this embodiment is prepared from the following components in parts by weight:

[0098] 54 parts of crystalline polyester polyol (Evonik, Dynacoll® 7360), 40 parts of liquid polyester polyol (Asahikawa, CTP-244), 10 parts of polycarbonate diol, 60 parts of polypropylene glycol with a number average molecular weight of 2000, 52 parts of acrylic resin with a number average molecular weight of 30000, 45 parts of isocyanate (diphenylmethane-4,4'-diisocyanate (CAS No. 101-68-8)), 0.8 parts of 1,6-hexanediol, 3 parts of adhesion promoter N-aminoethyl-γ-aminopropyltrimethoxysilane, 0.2 parts of catalyst dimorpholinodiethyl ether, and 2 parts of antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0099] The preparation method of polycarbonate diol in this embodiment is the same as that in Example 1.

[0100] The preparation method of the high-performance moisture-curing polyurethane hot melt adhesive in this embodiment includes the following steps:

[0101] 1. According to the above-mentioned parts by weight of raw materials, crystalline polyester polyol, liquid polyester polyol, polycarbonate diol, polypropylene glycol, and acrylic resin are added to the reaction vessel, heated to 125°C, and vacuum dehydrated for 1.5 hours with stirring, and the vacuum degree is -0.095MPa.

[0102] 2. Purge with nitrogen to break the vacuum, add isocyanate, and react at 125°C for 1.5 hours under nitrogen protection.

[0103] 3. Add 1,6-hexanediol and react at 125°C for 0.5 hours under nitrogen protection.

[0104] 4. Add adhesion promoter, catalyst and antioxidant, and continue stirring at 110°C for 0.5 hours.

[0105] 5. Heat to 120℃, degas under vacuum, and discharge to obtain the high-performance moisture-curing polyurethane hot melt adhesive.

[0106] Comparative Example 1

[0107] This comparative example provides a high-performance moisture-curing polyurethane hot melt adhesive, whose components, content and preparation method are the same as those in Example 3, except that polycarbonate diol is replaced with liquid polyester polyol (Asahikawa, CTP-244).

[0108] Comparative Example 2

[0109] This comparative example provides a high-performance moisture-curing polyurethane hot melt adhesive, whose components, content, and preparation method are the same as those in Example 3, except that the adhesion promoter N-aminoethyl-γ-aminopropyltrimethoxysilane is not added.

[0110] Comparative Example 3

[0111] This comparative example provides a high-performance moisture-curing polyurethane hot melt adhesive, whose components, content, and preparation method are the same as those in Example 3, except that 1,3-propanediol is not added.

[0112] Comparative Example 4

[0113] This comparative example provides a high-performance moisture-curing polyurethane hot melt adhesive, whose components and preparation method are the same as those in Example 3, except that: the polycarbonate diol is 60 parts, the polypropylene glycol with a number average molecular weight of 2000 is 32 parts, and the proportions of the remaining components remain unchanged.

[0114] Comparative Example 5

[0115] This comparative example provides a high-performance moisture-curing polyurethane hot melt adhesive, whose components, content, and preparation method are the same as those in Example 3, except that the added adhesion promoter is (3-methacryloyloxy-2-hydroxypropoxy)propylbis(trimethylsiloxy)methylsilane.

[0116] Comparative Example 6

[0117] This comparative example provides a high-performance moisture-curing polyurethane hot melt adhesive, whose components, content, and preparation method are the same as those in Example 3, except that the polycarbonate diol is prepared from 1,6-hexanediol, 3-methyl-1,5-pentanediol, and dimethyl carbonate.

[0118] Comparative Example 7

[0119] This comparative example provides a high-performance moisture-curing polyurethane hot melt adhesive, whose components, content, and preparation method are the same as those in Example 3, except that the polycarbonate diol is prepared from 1,6-hexanediol, 1,5-pentanediol, and dimethyl carbonate.

[0120] Comparative Example 8

[0121] This comparative example provides a high-performance moisture-curing polyurethane hot melt adhesive, whose components, content, and preparation method are the same as those in Example 3, except that the polycarbonate diol is prepared from 1,4-butanediol, 2-methyl-2-propyl-1,3-propanediol, and dimethyl carbonate.

[0122] Comparative Example 9

[0123] This comparative example provides a high-performance moisture-curing polyurethane hot melt adhesive, whose components, content, and preparation method are the same as those in Example 3, except that the molar ratio of 1,6-hexanediol, 2-methyl-2-propyl-1,3-propanediol, and dimethyl carbonate is 3:1:4.

[0124] Comparative Example 10

[0125] This comparative example provides a high-performance moisture-curing polyurethane hot melt adhesive, whose components, content, and preparation method are the same as those in Example 3, except that the molar ratio of 1,6-hexanediol, 2-methyl-2-propyl-1,3-propanediol, and dimethyl carbonate is 1:3:4.

[0126] The following performance tests were performed on the high-performance moisture-curing polyurethane hot melt adhesives prepared in the examples and comparative examples:

[0127] Melt viscosity: Refer to GB / T 10247-2008 to test the melt viscosity of hot melt adhesive at 130℃.

[0128] Open time: Heat the adhesive to a molten state at 120℃, and under 25℃ / 50RH% environmental conditions, apply a 2mm*200mm adhesive strip to a polytetrafluoroethylene plate using a glue gun. Press 25mm*100mm ABS test pieces onto the surface of the adhesive strip at 15mm intervals, and record the time until no adhesive sticks to the surface of the ABS test pieces.

[0129] Elongation at break: Refer to GB / T 528 for testing elongation at break.

[0130] Tensile shear strength: Referring to GB / T 7124-2008, ink-glass-ABS specimens were prepared, and the initial tack strength after 15 minutes of curing and the final tack strength after 7 days of curing were tested.

[0131] Adhesion performance test: Referring to GB / T 7124-2008, ink glass-ABS test pieces were prepared. After curing the test pieces at 23℃ / 50%RH for 7 days, aging tests were conducted under the conditions in Table 1. After aging, the tensile shear strength was tested after standing at 23℃-50%RH for 4 hours.

[0132] Table 1 Aging Test

[0133]

[0134] Table 2 Performance test results of the examples and comparative examples

[0135]

[0136]

[0137] As can be seen from the performance comparison of Examples 1-5 and Comparative Examples 1-3 in Table 2, Examples 1-5 with added polycarbonate diol have significantly higher final tack strength than Comparative Example 1 without added polycarbonate diol, and their corresponding tensile shear strength after aging tests is also higher than that of Comparative Example 1. Comparative Example 1 without added polycarbonate diol has a low hydrolysis activation energy of the ester bonds (-CO-O-) on its main chain. At 85℃ / 85%RH, water molecules rapidly cleave the ester bonds, leading to polymer degradation and a sharp decline in strength. Example 3 with added adhesion promoter has significantly higher final tack strength and tensile shear strength after aging than Comparative Example 2. Example 3 with added small molecule diol has significantly higher melt viscosity, elongation at break, and bond strength than Comparative Example 3. Compared to Example 3, Comparative Example 4 showed a decrease in viscosity, and a significant decrease in elongation at break and tensile shear strength. This may be because the excessive introduction of polycarbonate diol led to a poorer separation effect between the soft and hard microphases of the colloid, resulting in a reduced elongation at break and an inability to effectively disperse stress, thus causing a decrease in bond strength. Compared to Example 3, Comparative Example 5 showed poorer final bond strength, high temperature and humidity, low temperature aging, and thermal cycling tensile shear strength, and did not improve the adhesion of the ink to the glass. This may be because when (3-methacryloyloxy-2-hydroxypropoxy)propylbis(trimethylsiloxy)methylsilane was used as an adhesion promoter, the trimethylsiloxy groups it contained formed a stable siloxane skeleton. These Si-O-Si bonds are very stable and cannot be hydrolyzed and crosslinked, thus not improving the adhesion of the ink to the glass.

[0138] Compared to Example 3, Comparative Examples 6 and 7, by replacing 2-methyl-2-propyl-1,3-propanediol with 3-methyl-1,5-pentanediol and 1,5-pentanediol respectively, resulted in decreased viscosity and significantly reduced resistance to high temperature and humidity, as well as thermal shock. Compared to Example 3, Comparative Example 8, by replacing the long-chain 1,6-hexanediol with the short-chain 1,4-butanediol, resulted in a significant decrease in elongation at break, as well as reduced resistance to high temperature and humidity, and thermal shock. Compared to Example 3, Comparative Example 9, by reducing the amount of 2-methyl-2-propyl-1,3-propanediol, resulted in poorer hydrolysis resistance and a significant decrease in bond strength after high temperature and humidity aging; while Comparative Example 10, by reducing the amount of 1,6-hexanediol, resulted in significantly increased viscosity. Although it exhibited excellent hydrolysis resistance, its bond strength was poor, and its elongation at break was low. This indicates that the type and proportion of each component are very important when preparing polycarbonate diol. Polycarbonate diol prepared by using 1,6-hexanediol, 2-methyl-2-propyl-1,3-propanediol and dimethyl carbonate in appropriate proportions not only has high bonding strength to ink glass and ABS in polyurethane hot melt adhesives, but also has excellent aging resistance and excellent flexibility. It can effectively absorb the interfacial stress generated by alternating hot and cold temperatures and prevent delamination or cracking.

[0139] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0140] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A high-performance moisture-curing polyurethane hot melt adhesive, characterized in that, It is prepared from raw materials comprising the following components, by weight: 40-60 parts of crystalline polyester polyol 10-40 parts of liquid polyester polyol 10-40 parts of polycarbonate diol 40-60 parts of polyether polyol 40-60 parts of thermoplastic resin 0.6-1 part of diol 32-45 parts of isocyanate 1-3 parts of adhesion promoter Catalyst 0.1-0.3 parts 1-2 parts antioxidant; The polycarbonate diol is prepared from 1,6-hexanediol, 2-methyl-2-propyl-1,3-propanediol and dimethyl carbonate.

2. The high-performance moisture-curing polyurethane hot melt adhesive as described in claim 1, characterized in that, The molar ratio of 1,6-hexanediol, 2-methyl-2-propyl-1,3-propanediol and dimethyl carbonate is 2~4:2~4:3~5, preferably 3:3~4:4~5, and more preferably 3:3~3.2:4~4.

2.

3. The high-performance moisture-curing polyurethane hot melt adhesive as described in claim 2, characterized in that, The preparation method of the polycarbonate diol includes the following steps: S1. Mix 1,6-hexanediol, 2-methyl-2-propyl-1,3-propanediol and dimethyl carbonate and react at 120℃~140℃ for 4h~6h; S2. Increase the temperature to 200℃~230℃, evacuate to -0.04MPa~-0.07MPa, and continue the reaction for 1h~2h; S3. Continue evacuating to -0.095MPa to -0.1MPa and continue the reaction for 1.5h to 2h; S4. After the reaction is complete, the material is discharged when the temperature drops below 100°C under nitrogen atmosphere protection to obtain the polycarbonate diol.

4. The high-performance moisture-curing polyurethane hot melt adhesive as described in claim 1, characterized in that, It is prepared from raw materials comprising the following components, by weight: 55-60 parts of crystalline polyester polyol 10-15 parts of liquid polyester polyol 35-40 parts of polycarbonate diol 50-55 parts of polyether polyol 45-50 parts of thermoplastic resin 0.6-1 part of diol 40-45 parts of isocyanate 2-3 parts of adhesion promoter Catalyst 0.1-0.3 parts Antioxidant 1-2 parts.

5. The high-performance moisture-curing polyurethane hot melt adhesive according to any one of claims 1-4, characterized in that, The adhesion promoter is at least one of N-aminoethyl-γ-aminopropyltrimethoxysilane, N-n-butyl-3-aminopropyl-trimethoxysilane, di(3-trimethoxysilylpropyl)amine, and 3-mercaptopropyltrimethoxysilane, preferably N-aminoethyl-γ-aminopropyltrimethoxysilane.

6. The high-performance moisture-curing polyurethane hot melt adhesive according to any one of claims 1-4, characterized in that, The diol is at least one selected from 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, and 1,3-propanediol, preferably 1,3-propanediol.

7. The high-performance moisture-curing polyurethane hot melt adhesive according to any one of claims 1-4, characterized in that, The hydroxyl value of the crystalline polyester polyol is 20mKOH / g to 60mKOH / g, preferably 25mKOH / g to 40mKOH / g.

8. The high-performance moisture-curing polyurethane hot melt adhesive according to any one of claims 1-4, characterized in that, The polyether polyol is one or more of polypropylene glycol and polytetramethylene ether glycol with a number average molecular weight of 1000-3000, preferably polypropylene glycol with a number average molecular weight of 1800-2200.

9. The high-performance moisture-curing polyurethane hot melt adhesive according to any one of claims 1-4, characterized in that, The thermoplastic resin is an acrylic resin with a number average molecular weight of 30,000-40,000. And / or, the isocyanate is diphenylmethane-4,4'-diisocyanate; And / or, the catalyst is one or more of dibutyltin dilaurate, stannous octoate, dimorpholino diethyl ether, and triethylamine; And / or, the antioxidant is one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris[2,4-di-tert-butylphenyl]phosphite, octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 2,6-di-tert-butyl-4-methylphenol.

10. A method for preparing the high-performance moisture-curing polyurethane hot melt adhesive according to any one of claims 1-9, characterized in that, Includes the following steps: (1) Mix crystalline polyester polyol, liquid polyester polyol, polycarbonate diol, polyether polyol and thermoplastic resin, and vacuum dehydrate at 110℃~130℃ for 1.5h-3h; (2) Add isocyanate and react at 90℃~130℃ for 1h~3h under nitrogen protection; (3) Add diol and react at 90℃~130℃ for 0.5h-1h under nitrogen protection; (4) Add adhesive accelerator, catalyst and antioxidant in sequence, and continue to react at 90℃~120℃ for 0.5h-1h under nitrogen atmosphere protection. Finally, degas under vacuum at 110℃~120℃ to obtain the wet curing polyurethane hot melt adhesive.

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