Block type polyester polyol as well as preparation method and application thereof

Abstract

The invention provides block type polyester polyol as well as a preparation method and application thereof, and relates to the technical field of adhesives. The preparation method of the block type polyester polyol comprises the following steps: mixing binary acid A and dihydric alcohol A, and carrying out esterification reaction to prepare polyester polyol A; binary acid B and dihydric alcohol B are mixed for esterification reaction to prepare polyester polyol B; and 2) mixing the polyester polyol A, the polyester polyol B, a catalyst and a dehydrating agent, and carrying out condensation polymerization to obtain the block polyester polyol. By means of distributed esterification and rapid polycondensation, the product has a block structure, and the processability can be remarkably improved while the excellent application performance of a main body structure is kept.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, and in particular to a block polyester polyol and a preparation method and application thereof. Background Art

[0002] The use of solvent-free, high-solid content (solid content ≥50wt%) adhesives will significantly reduce solvent consumption and emissions, helping companies achieve energy conservation and emission reduction while reducing costs. During the research and development of such adhesives, the structure of the main polymer resin will significantly affect the rheological properties and construction performance of the adhesive. Generally speaking, the main structure of moisture-heat resistant polymers is mainly rigid structure, the glass transition temperature of the polymer is high, the viscosity is large in solution or when melted, the dilution time is long in actual application, and the coating is uneven during glue application. If a rigid structure is not used, the application performance of the adhesive will be significantly affected.

[0003] Patent CN116004171A discloses a method for preparing a low-viscosity, heat-resistant adhesive, which reacts epoxy resin, polyol and isocyanate together, and reduces the viscosity of the adhesive while ensuring performance by increasing the degree of branching of the polymer. This method solves the problem of balancing performance and viscosity, but increasing the degree of branching of the polymer will increase the cross-linking density after later curing. In some application scenarios, such as cold forming, it has a greater impact on the depth and success rate of cold stamping. Therefore, how to disclose a block polyester polyol adhesive with low viscosity, low cross-linking density after curing, and no adverse effects on cold stamping during application is a problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0004] The object of the present invention is to provide a segmented polyester polyol and a preparation method and application thereof, so as to solve the problem that the existing adhesive has high viscosity and high crosslinking density after late curing, which will affect the stamping effect.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a segmented polyester polyol, comprising the following steps:

[0007] 1) mixing dibasic acid A and diol A to carry out esterification reaction to prepare polyester polyol A;

[0008] The dibasic acid B and the diol B are mixed to carry out an esterification reaction to prepare a polyester polyol B;

[0009] 2) mixing polyester polyol A, polyester polyol B, a catalyst and a dehydrating agent to carry out polycondensation reaction to obtain a block polyester polyol;

[0010] The dibasic acid A is selected from one or more of 1,4-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic anhydride, 1,4-succinic acid, 1,5-pentanedioic acid, 1,6-hexanedioic acid, 1,8-octanedioic acid, 1,9-zelaic acid and 1,10-decanedioic acid;

[0011] The diol A is selected from one or more of 1,6-hexanediol, 2,2-dimethylpropylene glycol, ethylene glycol, diethylene glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 2,2-dimethyl-1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol and 2-ethyl-1,3-hexanediol;

[0012] The dibasic acid B is selected from one or more of terephthalic acid, isophthalic acid, 1,6-adipic acid, phthalic acid, phthalic anhydride, 1,8-octanedioic acid, 1,9-zelaic acid and 1,10-decanedioic acid;

[0013] The diol B is selected from one or more of ethylene glycol, 2,2-dimethylpropylene glycol, diethylene glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 2,2-dimethyl-1,3-propylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol and 2-ethyl-1,3-hexanediol.

[0014] Preferably, the temperature of the esterification reaction for preparing polyester polyol A in step 1) is 220-240° C. and the time is 1-2 h;

[0015] The number average molecular weight of the polyester polyol A is 500-4000.

[0016] Preferably, in step 1), the molar ratio of the dibasic acid A to the diol A is 1:1.2-1.6.

[0017] Preferably, the temperature of the esterification reaction for preparing polyester polyol B in step 1) is 240-260° C. and the time is 1-2 h;

[0018] The number average molecular weight of the polyester polyol B is 2,000 to 10,000.

[0019] Preferably, in step 1), the molar ratio of the dibasic acid B to the diol B is 1:1.15-1.5.

[0020] Preferably, in step 2), the mass ratio of the polyester polyol A to the polyester polyol B is 1:1.5-6.

[0021] Preferably, the catalyst in step 2) is one or more of tin octoate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate and tin chloride;

[0022] The amount of the catalyst is 0.02-0.1% of the total mass of polyester polyol A and polyester polyol B;

[0023] The dehydrating agent is 1,3-diisopropylcarbodiimide and / or 1,3-dicyclohexylcarbodiimide;

[0024] The amount of the dehydrating agent used is 0.02-0.1% of the total mass of the polyester polyol A and the polyester polyol B.

[0025] Preferably, the temperature of the polycondensation reaction in step 2) is 230-250° C., the time is 0.5-1 h, and the absolute pressure of the vacuum degree is 10-150 Pa.

[0026] The present invention also provides a segmented polyester polyol prepared by the above preparation method, wherein the number average molecular weight of the segmented polyester polyol is 12000-60000.

[0027] The present invention also provides an application of the above-mentioned block polyester polyol in an adhesive, and the application method is as follows:

[0028] The block polyester polyol is mixed with a solvent, a silane coupling agent, an epoxy resin and an isocyanate curing agent to prepare an adhesive;

[0029] The adhesive can be used to bond metal foil and plastic film.

[0030] The present invention has at least the following beneficial effects:

[0031] The present invention provides a method for preparing polyester polyols, which can make the products have block structures by means of distributed esterification and rapid polycondensation, and can significantly improve the processing performance while maintaining the excellent application performance of the main structure. The adhesive prepared by using the block polyester polyol prepared by the present invention has excellent application performance and low viscosity, and can significantly improve the moisture and heat resistance of the adhesive and reduce the viscosity without changing the branching degree of the polymer. It is suitable for scenes such as cold forming that require the deformation performance of the adhesive body, and is suitable for the bonding of various metal films and plastic films. DETAILED DESCRIPTION

[0032] The present invention provides a method for preparing a segmented polyester polyol, comprising the following steps:

[0033] 1) mixing dibasic acid A and diol A to carry out esterification reaction to prepare polyester polyol A;

[0034] The dibasic acid B and the diol B are mixed to carry out an esterification reaction to prepare a polyester polyol B;

[0035] 2) mixing polyester polyol A, polyester polyol B, a catalyst and a dehydrating agent to carry out polycondensation reaction to obtain a block polyester polyol;

[0036] The dibasic acid A is selected from one or more of 1,4-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic anhydride, 1,4-succinic acid, 1,5-pentanedioic acid, 1,6-hexanedioic acid, 1,8-octanedioic acid, 1,9-zelaic acid and 1,10-decanedioic acid;

[0037] The diol A is selected from one or more of 1,6-hexanediol, 2,2-dimethylpropylene glycol, ethylene glycol, diethylene glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 2,2-dimethyl-1,3-propylene glycol (neopentyl glycol), 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol and 2-ethyl-1,3-hexanediol;

[0038] The dibasic acid B is selected from one or more of terephthalic acid, isophthalic acid, 1,6-adipic acid, phthalic acid, phthalic anhydride, 1,8-octanedioic acid, 1,9-zelaic acid and 1,10-decanedioic acid;

[0039] The diol B is selected from one or more of ethylene glycol, 2,2-dimethylpropylene glycol, diethylene glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 2,2-dimethyl-1,3-propylene glycol (neopentyl glycol), 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol and 2-ethyl-1,3-hexanediol.

[0040] In the present invention, the temperature of the esterification reaction for preparing polyester polyol A in step 1) is 220-240°C, preferably 225-235°C, more preferably 228-232°C, and more preferably 230°C; the time is 1-2h, preferably 1.25-1.75h, and more preferably 1.5h.

[0041] In the present invention, after the esterification reaction is completed, the step of continuing heating under vacuum conditions to remove unreacted monomers is further included, and the absolute pressure of the vacuum degree is 2-4 KPa, preferably 2.5-3.5 KPa, more preferably 2.8-3.2 KPa, and more preferably 3 KPa.

[0042] The number average molecular weight of the polyester polyol A is 500-4000.

[0043] In the present invention, the molar ratio of the dibasic acid A to the diol A in step 1) is 1:1.2-1.6, preferably 1:1.3-1.5, and more preferably 1:1.4.

[0044] In the present invention, the temperature of the esterification reaction for preparing polyester polyol B in step 1) is 240-260°C, preferably 245-255°C, more preferably 248-252°C, and more preferably 250°C; the time is 1-2h, preferably 1.25-1.75h, and more preferably 1.5h.

[0045] In the present invention, after the esterification reaction is completed, the step of continuing heating under vacuum conditions to remove unreacted monomers is further included, and the absolute pressure of the vacuum degree is 2-4 KPa, preferably 2.5-3.5 KPa, more preferably 2.8-3.2 KPa, and more preferably 3 KPa.

[0046] In the present invention, the number average molecular weight of the polyester polyol B is 2,000 to 10,000.

[0047] In the present invention, the molar ratio of the dibasic acid B to the diol B in step 1) is 1:1.15-1.5, preferably 1:1.2-1.45, more preferably 1:1.25-1.4, and more preferably 1:1.3.

[0048] In the present invention, the mass ratio of the polyester polyol A to the polyester polyol B in step 2) is 1:1.5-6, preferably 1:2-5, and more preferably 1:3-4.

[0049] In the present invention, the catalyst in step 2) is one or more of tin octoate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate and tin chloride.

[0050] In the present invention, the amount of the catalyst used is 0.02-0.1% of the total mass of polyester polyol A and polyester polyol B, preferably 0.04-0.08%, and more preferably 0.05-0.06%.

[0051] In the present invention, the dehydrating agent is 1,3-diisopropylcarbodiimide and / or 1,3-dicyclohexylcarbodiimide.

[0052] In the present invention, the amount of the dehydrating agent is 0.02-0.1% of the total mass of polyester polyol A and polyester polyol B, preferably 0.03-0.09%, more preferably 0.04-0.08%, and more preferably 0.05-0.07%.

[0053] In the present invention, the temperature of the polycondensation reaction in step 2) is 230-250°C, preferably 235-245°C, further preferably 238-243°C, and more preferably 240°C; the time is 0.5-1h, and the absolute pressure of the vacuum degree is 10-150Pa, preferably 30-130Pa, further preferably 50-110Pa, and more preferably 70-100Pa.

[0054] The present invention also provides a segmented polyester polyol prepared by the above preparation method, wherein the number average molecular weight of the segmented polyester polyol is 12000-60000.

[0055] The present invention also provides an application of the above-mentioned block polyester polyol in an adhesive, and the application method is as follows.

[0056] The block polyester polyol is mixed with a solvent, a silane coupling agent, an epoxy resin and an isocyanate curing agent to prepare an adhesive.

[0057] In the present invention, the mass ratio of the segmented polyester polyol, the solvent, the silane coupling agent, the epoxy resin, the anti-hydrolysis agent and the isocyanate curing agent is.......

[0058] In the present invention, the solvent is ethyl acetate and / or 2-butanone.

[0059] In the present invention, the silane coupling agent can be selected from (vinyl tri(β-methoxyethoxy) silane, vinyl ethoxy silane, vinyl trimethoxy silane, γ-(meth)acryloxypropyl trimethoxy silane, γ-(meth)acryloxypropyl triethoxy silane, γ-(meth)acryloxypropyl dimethoxymethyl silane, β-(3,4-epoxycyclohexyl)ethyl trimethoxy silane, β-(3,4-epoxycyclohexyl)methyl trimethoxy silane, β-(3,4-epoxycyclohexyl)ethyl triethoxy silane, β-(3,4-epoxycyclohexyl)methyl trimethoxy silane, The invention can be one or more of 2-(6-hexyl)methyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-mercaptopropyltriethoxysilane.

[0060] The adhesive can be used to bond metal foil and plastic film.

[0061] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0062] Example 1

[0063] 730.7 g of 1,6-hexanediol, 199.4 g of 1,6-hexanediol, 351.5 g of 2,2-dimethylpropylene glycol (neopentyl glycol) and 104.75 g of ethylene glycol were mixed and put into a 2.5 L reactor, and the temperature was raised to 230 ° C for esterification reaction. After reacting for 2 hours, the vacuum degree was gradually increased to an absolute pressure of 3 kPa within 1 hour to remove unreacted monomers. The vacuum degree was maintained for 0.5 hours to obtain polyester polyol A-1 with a number average molecular weight of 988.

[0064] 415.32 g of terephthalic acid, 207.66 g of isophthalic acid, 182.67 g of 1,6-hexanedioic acid, 186.21 g of ethylene glycol, and 312.45 g of 2,2-dimethylpropylene glycol (neopentyl glycol) were mixed and put into a 2.5 L reactor, and the temperature was raised to 250°C for esterification reaction. After reacting for 2 hours, the vacuum degree was gradually increased to an absolute pressure of 3 kPa within 1 hour to remove unreacted monomers. The vacuum degree was maintained for 0.5 hours to obtain polyester polyol B-1 with a number average molecular weight of 2752.

[0065] At 240°C, 300 g of polyester polyol A-1 and 200 g of polyester polyol B-1 were mixed under nitrogen protection, 0.75 g of dibutyltin dilaurate as a catalyst and 1.5 g of 1,3-diisopropylcarbodiimide as a dehydrating agent were added, the vacuum degree was increased to an absolute pressure of ≤100 Pa, and the vacuum degree was maintained for 0.5 h to obtain a segmented polyester polyol 1 with a number average molecular weight of 23392.

[0066] Example 2

[0067] 365.35 g of 1,6-hexanediic acid, 385.4 g of cyclohexanedicarboxylic anhydride, 199.4 g of 1,6-hexanediol, 351.5 g of 2,2-dimethylpropylene glycol (neopentyl glycol) and 104.75 g of ethylene glycol were mixed and put into a 2.5 L reactor, and the temperature was raised to 230 ° C for esterification reaction. After reacting for 2 hours, the vacuum degree was gradually increased to an absolute pressure of 3 kPa within 1 hour to remove unreacted monomers. The vacuum degree was maintained for 0.5 hours to obtain polyester polyol A-2 with a number average molecular weight of 973.

[0068] 622.99 g of phthalic acid, 182.67 g of 1,6-hexanedioic acid, 186.21 g of ethylene glycol and 312.45 g of 2,2-dimethylpropylene glycol (neopentyl glycol) were mixed and put into a 2.5 L reactor, and the temperature was raised to 250 °C for esterification. After reacting for 2 h, the vacuum degree was gradually increased to an absolute pressure of 3 kPa within 1 h to remove the unreacted monomers. The vacuum degree was maintained for 0.5 h to obtain polyester polyol B-2 with a number average molecular weight of 2630.

[0069] At 240°C, 300 g of polyester polyol A-2 and 1200 g of polyester polyol B-2 were mixed under nitrogen protection, 0.75 g of dibutyltin dilaurate as a catalyst and 1.5 g of 1,3-diisopropylcarbodiimide as a dehydrating agent were added, the vacuum degree was increased to an absolute pressure of ≤100 Pa, and the vacuum degree was maintained for 0.5 h to obtain a segmented polyester polyol 2 with a number average molecular weight of 22539.

[0070] Example 3

[0071] 756.1 g of 1,9-nonedioic acid, 325.8 g of 2,2-dimethyl-1,3-propanediol and 403.7 g of 1,4-butanediol were mixed and put into a 2.5 L reactor, and the temperature was raised to 230°C for esterification reaction. After reacting for 1.5 hours, the vacuum degree was gradually increased to an absolute pressure of 3 kPa within 1 hour to remove the unreacted monomers. The vacuum degree was maintained for 0.5 hours to obtain polyester polyol A-3 with a number average molecular weight of 1005.

[0072] 510.6 g of 1,8-octanedioic acid, 122.3 g of phthalic acid, 188.21 g of ethylene glycol, and 437.6 g of 3-methyl-1,5-pentanediol were mixed and put into a 2.5 L reactor, and the temperature was raised to 250 ° C for esterification reaction. After reacting for 2 hours, the vacuum degree was gradually increased to an absolute pressure of 3 kPa within 1 hour to remove unreacted monomers. The vacuum degree was maintained for 0.5 hours to obtain polyester polyol B-3 with a number average molecular weight of 2783.

[0073] At 240°C, 300 g of polyester polyol A-3 and 1200 g of polyester polyol B-3 were mixed under nitrogen protection, 0.75 g of dibutyltin dilaurate as a catalyst and 1.5 g of 1,3-diisopropylcarbodiimide as a dehydrating agent were added, the vacuum degree was increased to an absolute pressure of ≤100 Pa, and the vacuum degree was maintained for 0.5 h to obtain a segmented polyester polyol 3 with a number average molecular weight of 24075.

[0074] Example 4

[0075] 784.2 g of 1,4-cyclohexanedicarboxylic anhydride, 257.7 g of 1,4-butanediol, 322.8 g of 2-ethyl-1,3-hexanediol and 207.9 g of diethylene glycol were mixed and put into a 2.5 L reactor, and the temperature was raised to 230°C for esterification reaction. After reacting for 1.75 hours, the vacuum degree was gradually increased to an absolute pressure of 3 kPa within 1 hour to remove unreacted monomers. The vacuum degree was maintained for 0.5 hours to obtain polyester polyol A-4 with a number average molecular weight of 991.

[0076] 389.6 g of phthalic anhydride, 176.5 g of 1,10-decanedioic acid, 190.7 g of 1,6-hexanediol, 214.4 g of ethylene glycol and 320.75 g of 2,2-dimethyl-1,3-propylene glycol were mixed and put into a 2.5 L reactor, and the temperature was raised to 250 ° C for esterification reaction. After reacting for 2 hours, the vacuum degree was gradually increased to an absolute pressure of 3 kPa within 1 hour to remove unreacted monomers. The vacuum degree was maintained for 0.5 hours to obtain polyester polyol B-4 with a number average molecular weight of 2838.

[0077] At 240°C, 300 g of polyester polyol A-4 and 1200 g of polyester polyol B-4 were mixed under nitrogen protection, 0.75 g of dibutyltin dilaurate as a catalyst and 1.5 g of 1,3-diisopropylcarbodiimide as a dehydrating agent were added, the vacuum degree was increased to an absolute pressure of ≤100 Pa, and the vacuum degree was maintained for 0.5 h to obtain a segmented polyester polyol 4 with a number average molecular weight of 25472.

[0078] Comparative Example 1

[0079] 332.26 g of terephthalic acid, 166.12 g of isophthalic acid, 292.28 g of 1,6-hexanediol, 39.88 g of 1,6-hexanediol, 169.92 g of ethylene glycol, and 320.26 g of 2,2-dimethylpropylene glycol (neopentyl glycol) were mixed and put into a 2.5 L reactor, and the temperature was raised to 250° C. for esterification reaction. After reacting for 2 hours, the vacuum degree was gradually increased to an absolute pressure of 3 kPa within 1 hour, and the vacuum degree was maintained for 0.5 hours. 0.75 g of catalyst dibutyltin dilaurate and 1.5 g of dehydrating agent 1,3-diisopropylcarbodiimide were added, and the vacuum degree was increased to an absolute pressure of ≤100 Pa, and the vacuum degree was maintained for 0.6 hours to obtain polyester polyol comparison 1 with a number average molecular weight of 23355.

[0080] The raw materials used in this comparative example are the same as those in Example 1, and a polyester polyol having a number average molecular weight similar to that in Example 1 is prepared by a one-pot method.

[0081] Comparative Example 2

[0082] 730.7 g of 1,6-hexanediol, 199.4 g of 1,6-hexanediol, 351.5 g of 2,2-dimethylpropylene glycol (neopentyl glycol) and 104.75 g of ethylene glycol were mixed and put into a 2.5 L reactor, and the temperature was raised to 230°C for esterification reaction. After reacting for 2 hours, the vacuum degree was gradually increased to an absolute pressure of 3 kPa within 1 hour, and the vacuum degree was maintained for 0.5 hours. 0.75 g of catalyst dibutyltin dilaurate and 1.5 g of dehydrating agent 1,3-diisopropylcarbodiimide were added, and the vacuum degree was increased to an absolute pressure of ≤100 Pa, and the vacuum degree was maintained for 1.2 hours to obtain polyester polyol comparison 2-A with a number average molecular weight of 22916.

[0083] 415.32 g of terephthalic acid, 207.66 g of isophthalic acid, 182.67 g of 1,6-hexanedioic acid, 186.21 g of ethylene glycol, and 312.45 g of 2,2-dimethylpropylene glycol (neopentyl glycol) were mixed and put into a 2.5 L reactor, and the temperature was raised to 250°C for esterification reaction. After reacting for 2 hours, the vacuum degree was gradually increased to an absolute pressure of 3 kPa within 1 hour, and the vacuum degree was maintained for 1 hour to obtain a polyester polyol comparison 2-B with a number average molecular weight of 23949.

[0084] 300 g of polyester polyol comparative 2-A and 1200 g of polyester polyol comparative 2-B were mixed to obtain polyester polyol comparative 2, having a number average molecular weight of 23717.

[0085] The number average molecular weight in the above examples and comparative examples was measured by gel chromatography.

[0086] The application effects of the segmented polyester polyol 1 prepared in Example 1, the segmented polyester polyol 2 prepared in Example 2, the polyester polyol comparison 1 prepared in Comparative Example 1, and the polyester polyol comparison 2 prepared in Comparative Example 2 were tested, and the testing method was as follows:

[0087] 46.5 g of each of block polyester polyol 1, block polyester polyol 1, polyester polyol comparison 1, and polyester polyol comparison 2 were taken, and then 1.5 g of silane coupling agent KH-560, 1.5 g of epoxy resin E20, 0.5 g of anti-hydrolysis agent HyMax110, 25 g of ethyl acetate, and 25 g of 2-butanone were added to prepare adhesive main agent solutions, which were recorded as adhesive 1, adhesive 2, adhesive comparison 1, and adhesive comparison 2. The viscosity of the adhesive main agent solution is shown in Table 1.

[0088] Table 1 Viscosity of different adhesive main agent solutions

[0089]

[0090] The above adhesive main agent solutions were mixed evenly according to the main agent: curing agent L75: solvent ethyl acetate = 10:2.5:15 (mass ratio) to obtain an adhesive.

[0091] The mixed adhesive was applied to the matte surface of the Al foil, the solvent was dried at 95°C for 90s, and then the OPA was compounded with it using a roller laminator in a conventional way. The roller temperature was 45-50°C, the roller pressure was 0.5-0.6MPa, and the travel speed was 50cm / min. Under this condition, the film thickness was 4μm.

[0092] The composite film was aged at 60°C for 144 hours and placed at room temperature for 24 hours, and then the following application tests were performed:

[0093] Normal and high temperature peel strength test: According to GB-T 2790-1995 Adhesive 180° Peel Strength Test Method Flexible Material to Rigid Material Standard Determination, the composite film sample is cut into a 15mm×200mm strip shape, and the unbonded ends of the materials on both sides of the tested adhesive layer are symmetrically clamped on the upper and lower clamps of the universal testing machine to ensure that the clamping parts will not slip, that is, the applied tension is evenly distributed on the width of the sample. Start the testing machine and separate the upper and lower clamps at a rate of 300mm / min. The testing machine gives the interlayer peel strength of the corresponding material.

[0094] Cold forming performance test: the composite film samples were cut into 70mm×130mm rectangular strips and cold formed at 25℃ using a deep punching machine. The mold was a 33mm×37mm double-pit mold with a chamfer r=2mm. Ten samples were tested at each deep punching depth. If no delamination occurred, it was qualified. The maximum deep punching depth was recorded as the highest deep punching depth.

[0095] Moisture and heat resistance test: Use the above cold forming performance test method to punch the composite film to a depth of 50 mm. Place the punched sample in a 60°C water bath and a 85°C / 85% RH constant temperature and humidity chamber to test the moisture and heat resistance, and record the longest time that the composite film's appearance remains intact.

[0096] The above test data is shown in Table 2:

[0097] Table 2 Performance parameters of Al / OPA membranes connected by different adhesives

[0098]

[0099] As can be seen from the results in Table 2, the adhesives 1 and 2 prepared using the block polyester polyols in Examples 1 and 2 have good bonding properties, cold forming properties and moisture and heat resistance. The adhesive Comparison 1 prepared using the polyester polyol described in Comparative Example 1 has a relatively chaotic structural unit, and the rigid moisture and heat resistant structure fails to form a longer chain segment, and its moisture and heat resistance is far worse than that of the adhesive prepared using the block polyester polyol described in the embodiment of the present invention. The adhesive Comparison 2 prepared using the polyester polyol described in Comparative Example 2 has certain moisture and heat resistance, but the long-chain low Tg resin (polyester polyol Comparative 2-A) reduces the bonding ability of the adhesive in a hot environment, and it cannot effectively protect the film material during cold forming.

[0100] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a block polyester polyol, characterized in that: The following steps are involved: 1) mixing dibasic acid A and diol A to carry out esterification reaction to prepare polyester polyol A; The dibasic acid B and the diol B are mixed to carry out an esterification reaction to prepare a polyester polyol B; 2) mixing polyester polyol A, polyester polyol B, a catalyst and a dehydrating agent to carry out polycondensation reaction to obtain a block polyester polyol; The dibasic acid A is selected from one or more of 1,4-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic anhydride, 1,4-succinic acid, 1,5-pentanedioic acid, 1,6-hexanedioic acid, 1,8-octanedioic acid, 1,9-zelaic acid and 1,10-decanedioic acid; The diol A is selected from one or more of 1,6-hexanediol, 2,2-dimethylpropylene glycol, ethylene glycol, diethylene glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 2,2-dimethyl-1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol and 2-ethyl-1,3-hexanediol; The dibasic acid B is selected from one or more of terephthalic acid, isophthalic acid, 1,6-adipic acid, phthalic acid, phthalic anhydride, 1,8-octanedioic acid, 1,9-zelaic acid and 1,10-decanedioic acid; The diol B is selected from one or more of ethylene glycol, 2,2-dimethylpropylene glycol, diethylene glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 2,2-dimethyl-1,3-propylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol and 2-ethyl-1,3-hexanediol.

2. The method for preparing a segmented polyester polyol according to claim 1, characterized in that: The temperature of the esterification reaction for preparing polyester polyol A in step 1) is 220-240° C. and the time is 1-2 hours; The number average molecular weight of the polyester polyol A is 500-4000.

3. The method for preparing a segmented polyester polyol according to claim 2, characterized in that: In step 1), the molar ratio of the dibasic acid A to the diol A is 1:1.2-1.

6.

4. The method for preparing a segmented polyester polyol according to claim 3, characterized in that: The temperature of the esterification reaction for preparing polyester polyol B in step 1) is 240-260° C. and the time is 1-2 hours; The number average molecular weight of the polyester polyol B is 2,000 to 10,000.

5. The method for preparing a segmented polyester polyol according to claim 4, characterized in that: In step 1), the molar ratio of the dibasic acid B to the diol B is 1:1.15-1.

5.

6. The method for preparing a segmented polyester polyol according to any one of claims 1 to 5, characterized in that: In step 2), the mass ratio of polyester polyol A to polyester polyol B is 1:1.5-6.

7. The method for preparing a segmented polyester polyol according to claim 6, characterized in that: The catalyst in step 2) is one or more of tin octoate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate and tin chloride; The amount of the catalyst is 0.02-0.1% of the total mass of polyester polyol A and polyester polyol B; The dehydrating agent is 1,3-diisopropylcarbodiimide and / or 1,3-dicyclohexylcarbodiimide; The amount of the dehydrating agent used is 0.02-0.1% of the total mass of the polyester polyol A and the polyester polyol B.

8. The method for preparing a segmented polyester polyol according to claim 7, characterized in that: The temperature of the polycondensation reaction in step 2) is 230-250° C., the time is 0.5-1 h, and the absolute pressure of the vacuum degree is 10-150 Pa.

9. The segmented polyester polyol prepared by the method for preparing a segmented polyester polyol according to any one of claims 1 to 8, characterized in that: The number average molecular weight of the segmented polyester polyol is 12,000 to 60,000.

10. Use of a block polyester polyol according to claim 9 in an adhesive, characterized in that: The application method is: The block polyester polyol is mixed with a solvent, a silane coupling agent, an epoxy resin and an isocyanate curing agent to prepare an adhesive; The adhesive can be used to bond metal foil and plastic film.

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