Polyether ester polymers, methods of making the same, and use in sealants

Abstract

The application belongs to the technical field of adhesives, and particularly relates to a polyether ester polymer, a preparation method thereof and application of the polyether ester polymer in sealant glue; the polyether ester polymer has a number average molecular weight of 6000-30000; the preparation method comprises the following steps: S1: mixing polyether polyol and itaconic acid to perform esterification reaction, so as to obtain a polyether ester polymer containing a double bond; S2: reacting the polyether ester polymer containing the double bond with alkoxysilane to end-cap the double bond, so as to obtain the polyether ester polymer. The polyether ester polymer can be applied to the field of adhesives, and the prepared sealant glue has excellent mechanical properties and high-temperature resistance, while the production process is safe, environmentally friendly, and has industrial feasibility.

Description

Technical Field

[0001] This invention belongs to the field of adhesive technology, and particularly relates to a polyether ester polymer, its preparation method, and its application in sealants. Background Technology

[0002] Currently, my country's adhesive consumption has reached seven million tons, mainly consisting of silicone sealants. However, with increasing environmental awareness, environmentally friendly adhesives, represented by MS adhesives, are gradually emerging. According to statistics from the China Adhesives and Adhesive Tapes Industry Association, my country's silane-modified (MS) adhesives achieved a high growth rate of nearly 40% in 2020. The MS adhesive industry has truly entered a period of explosive growth, and the industry's prospects are bright.

[0003] MS adhesive combines the performance advantages of both silicone and polyurethane sealants, and is free of formaldehyde and isocyanates. It boasts outstanding environmental characteristics such as being solvent-free, non-toxic, odorless, and having low VOC emissions, making it widely used in the construction, home decoration, and industrial sectors. However, because its cured product's main structure is polyether, conventional silane-modified polyethers exhibit poor temperature resistance and undergo chain segment breakdown under high temperature and humidity conditions. When applied to outdoor equipment, MS adhesive is highly susceptible to cracking and debonding, significantly shortening the equipment's lifespan. Furthermore, the MS resin used in MS adhesive undergoes a lengthy preparation process, involving double bond end-capping steps that utilize highly odorous allyl chloride, and generating substantial amounts of hazardous waste.

[0004] Therefore, it is worthwhile to continue developing sealants that ensure safe and environmentally friendly production processes, are industrially feasible, and also have high-temperature resistance properties. Summary of the Invention

[0005] The purpose of this invention is to address some technical problems existing in the current adhesive preparation process by providing a polyether ester polymer, its preparation method, and its application in sealants. By selecting a polyether ester polymer containing ester bonds and having curing properties, it can be applied to the adhesive field, and the resulting sealant has excellent mechanical properties and high-temperature resistance, while ensuring that the production process is safe and environmentally friendly and has industrial feasibility.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] In a first aspect, a polyether ester polymer is provided, the polyether ester polymer having a number average molecular weight of 6,000 to 30,000 (e.g., 6,500, 7,000, 8,000, 10,000, 12,000, 14,000, 15,000, 16,000, 20,000, 25,000, 28,000), preferably 10,000 to 18,000.

[0008] In some embodiments of the polyether ester polymer provided by the present invention, the chemical structural formula of the polyether ester polymer is shown below:

[0009]

[0010] In the formula,

[0011] R is a structure in water or a small molecule alcohol with the hydroxyl group removed, wherein the small molecule alcohol is selected from one or more of glycerol, trimethylolpropane, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, pentaerythritol, and sorbitol;

[0012] R' is independently alkyl or alkoxy (for example, R' connected to an oxygen atom can be methyl, ethyl, n-propyl, isopropyl, butyl; R' not connected to an oxygen atom can be methoxy, ethoxy, propoxy), a+b=2, where a takes the value 0 or 1;

[0013] The range of values ​​for x and y depends on the molecular weight of the polyether polyol used in the polyether ester polymer; M R +44x+58y represents the molecular weight of the polyether polyol, where 1000 ≤ M R +44x+58y≤6000, where M R This represents the molecular weight of the small molecule alcohol.

[0014] The range of values ​​for n depends on the number-average molecular weight of the polyether ester polymer; (n+1)*[M R +44x+58y]+n*130.1-2n*18+n*M SiOR’ This represents the number-average molecular weight of the polyether ester polymer, 6000≤(n+1)*[M R +44x+58y]+n*130.1-2n*18+n*M SiOR’ ≤30000, M SiOR’ This indicates the molecular weight of alkoxysilanes.

[0015] In a second aspect, a method for preparing a polyether ester polymer is provided, comprising the following steps:

[0016] S1: Polyether polyol and itaconic acid are mixed and subjected to esterification reaction to prepare polyether ester containing double bonds;

[0017] S2: The polyether ester containing double bonds is reacted with alkoxysilane to end the double bonds, thereby obtaining the polyether ester polymer;

[0018] in,

[0019] The polyether polyol has a molecular weight of 1000-6000 (e.g., 1200, 1400, 1500, 1600, 1800, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500), and the initiator used in the polyether polyol is a small molecule alcohol and / or water, preferably selected from one or more of water, glycerol, trimethylolpropane, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, pentaerythritol, and sorbitol; the epoxy compound used in the polyether polyol is a C2-C5 epoxy compound, preferably selected from one or more of ethylene oxide, propylene oxide, and butyl oxide.

[0020] In some embodiments, the catalyst used in the polyether polyol is an alkaline catalyst, preferably selected from one or more of KOH, NaOH, DMC catalyst systems and phosphononitrile catalysts.

[0021] According to the preparation method provided by the present invention, the ratio range of polyether polyol to itaconic acid can be determined according to the molecular weight of the desired polyether ester polymer, for example, it can be adjusted according to the type of polyether polyol selected and the molecular weight of the final polyether ester polymer.

[0022] According to the preparation method provided by the present invention, the ratio range of the polyether ester polymer containing double bonds to the alkoxysilane can be determined based on the end-capping rate of the alkoxysilane in the final polyether ester polymer.

[0023] According to the preparation method provided by the present invention, the number average molecular weight of the polyether ester polymer obtained is 6,000 to 30,000 (e.g., 6,500, 7,000, 8,000, 10,000, 12,000, 14,000, 15,000, 16,000, 20,000, 25,000, 28,000), preferably 10,000 to 18,000.

[0024] According to the preparation method provided by the present invention, in some embodiments, the reaction in step S1 includes an atmospheric pressure esterification reaction stage and a negative pressure esterification reaction stage.

[0025] In some embodiments, the process conditions for the atmospheric pressure esterification reaction stage include: a reaction temperature of 120–200°C (e.g., 130°C, 140°C, 150°C, 160°C, 185°C, 195°C), preferably 150–180°C; and a reaction time of 2–8 h (e.g., 2.5 h, 3 h, 4.5 h, 5 h, 6 h, 7.5 h), preferably 4–7 h.

[0026] In some embodiments, the process conditions for the negative pressure esterification reaction stage include: a reaction temperature of 150–210°C (e.g., 155°C, 160°C, 175°C, 180°C, 195°C, 205°C), preferably 170–200°C; a reaction time of 2–8 h (e.g., 2.5 h, 3 h, 4.5 h, 5 h, 6 h, 7.5 h), preferably 4–7 h; and a negative pressure of 2–40 kPaA (e.g., 2.5 kPaA, 3 kPaA, 4 kPaA, 6 kPaA, 8 kPaA, 10 kPaA, 12 kPaA, 16 kPaA, 18 kPaA, 20 kPaA, 25 kPaA, 30 kPaA, 35 kPaA), preferably 5–15 kPaA.

[0027] In some embodiments, the catalyst used in the negative pressure esterification reaction stage is a titanium-based catalyst, preferably selected from tetrabutyl titanate or tetraisopropyl titanate. The amount of the catalyst can be 2 to 20 ppm (e.g., 3 ppm, 4 ppm, 6 ppm, 8 ppm, 12 ppm, 14 ppm, 15 ppm, 18 ppm) of the total mass of the reactants in the system.

[0028] According to the preparation method provided by the present invention, the chemical structural formula of the polyether ester containing double bonds obtained in step S1 can be represented by the following general formula:

[0029]

[0030] In the formula,

[0031] R is a structure in water or a small molecule polyol with the hydroxyl group removed;

[0032] The range of values ​​for x and y depends on the molecular weight of the polyether polyol used; M R +44x+58y represents the molecular weight of the polyether polyol, where 1000 ≤ M R +44x+58y≤6000, where M R This represents the molecular weight of the small molecule polyol.

[0033] The range of values ​​for n depends on the molecular weight of the polyether ester containing double bonds or the molecular weight of the final polyether ester polymer.

[0034] According to the preparation method provided by the present invention, in some embodiments, the alkoxysilane is selected from one or more of methyldimethoxysilane, methyldiethoxysilane, trimethoxysilane, and triethoxysilane; and in the polyether ester polymer, the end-capping rate of the alkoxysilane is 50-95% (e.g., 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%).

[0035] According to the preparation method provided by the present invention, in some embodiments, the reaction in step S2 is carried out in the presence of a platinum-based catalyst;

[0036] In some embodiments, the platinum group catalyst is selected from caster catalysts and / or chloroplatinic acid catalysts;

[0037] In some embodiments, the amount of the platinum-based catalyst is 2 to 20 ppm (e.g., 3 ppm, 4 ppm, 6 ppm, 8 ppm, 12 ppm, 14 ppm, 15 ppm, 18 ppm) of the total mass of the reactants in step S2, preferably 5 to 10 ppm, wherein the amount of the platinum-based catalyst is based on the mass of Pt.

[0038] In some embodiments, the reaction process conditions for step S2 include: a reaction temperature of 50–120°C (e.g., 55°C, 65°C, 70°C, 80°C, 90°C, 105°C, 115°C), preferably 60–100°C; and a reaction time of 0.5–5 h (e.g., 1 h, 1.5 h, 2.5 h, 3 h, 3.5 h, 4.5 h), preferably 2–4 h.

[0039] According to the preparation method provided by the present invention, the number average molecular weight of the polyether ester polymer finally obtained is 6,000 to 30,000, preferably 10,000 to 18,000.

[0040] In a third aspect, the application of the polyether ester polymer as described above or the polyether ester polymer prepared by the preparation method as described above in the preparation of sealants is provided.

[0041] The specific operating steps and process conditions for the application of polyether ester polymers in the preparation of sealants can be conventional choices in the field and are not limited here.

[0042] In a fourth aspect, a sealant composition is provided, comprising: component A and component B;

[0043] Component A includes the polyether ester polymer as described above or the polyether ester polymer prepared by the preparation method described above; Component B includes a catalyst, which is an organotin compound, preferably selected from one or more of dibutyltin dilaurate, dioctyltin diacetate, stannous octoate, and diorganotin bis(β-diketone), more preferably stannous octoate.

[0044] In some embodiments of the sealant composition provided by the present invention, component A further includes one or more of a first plasticizer, nano-calcium carbonate, thixotropic agent, ultraviolet absorber, and antioxidant.

[0045] The first plasticizer may be diisononyl phthalate.

[0046] The thixotropic agent may be a polyamide wax.

[0047] The ultraviolet absorber may be Tinuvin 326.

[0048] The antioxidant may be Irga nox1076.

[0049] In some embodiments, component B further includes one or more of a second plasticizer, nano-calcium carbonate, and heavy calcium carbonate.

[0050] The second plasticizer may be PPG 3000.

[0051] In some embodiments of the sealant composition provided by the present invention, the weight parts of each raw material in component A are as follows:

[0052] Polyether ester polymer, 100 parts

[0053] First plasticizer, 40-60 parts (e.g., 45 parts, 50 parts, 55 parts),

[0054] Nano-calcium carbonate, 60-100 parts (e.g., 70 parts, 80 parts, 90 parts),

[0055] Thixotropic agent, 5-15 parts (e.g., 6 parts, 10 parts, 14 parts),

[0056] Ultraviolet absorber, 0.5-2 parts (e.g., 1 part, 1.5 parts),

[0057] Antioxidant, 0.5-2 parts (e.g., 1 part, 1.5 parts);

[0058] The weight proportions of each raw material in component B are as follows:

[0059] Second plasticizer, 100 parts

[0060] Nano-calcium carbonate, 40-60 parts (e.g., 45 parts, 50 parts, 55 parts),

[0061] Tricalcium phosphate, 80-120 servings (e.g., 90, 100, or 110 servings),

[0062] Catalyst, 30-50 parts (e.g., 35 parts, 40 parts, 45 parts).

[0063] In this article, the operation and process conditions for dispersing and mixing the raw materials in component A can be conventional operations in the art; and the operation and process conditions for dispersing and mixing the raw materials in component B can be conventional operations in the art; these will not be elaborated here.

[0064] In a fifth aspect, a sealant is provided, formed from the sealant composition described above. The operation of curing the sealant composition to form the sealant is a conventional choice in the art and will not be elaborated further here.

[0065] The polyether ester polymer of the present invention contains ester bonds and has curing properties. When used to prepare sealants, the cured sealants can have high-temperature resistance.

[0066] The polyether ester polymer preparation method of this invention cleverly utilizes the esterification reaction of itaconic acid and polyether polyol to introduce double bond groups into the polymer chain segment. These double bond groups in the polymer chain segment can undergo hydrosilylation with hydrogen-containing alkoxysilanes, introducing alkoxy groups with curing properties. This imparts both adhesive properties and high-temperature resistance to the polymer, improving the mechanical properties and high-temperature resistance of sealants when applied in the adhesive field. Furthermore, the polyether ester polymer preparation method involves only two steps, with relatively mild reaction conditions, a safe and environmentally friendly production process, and industrial feasibility. Detailed Implementation

[0067] To provide a detailed understanding of the technical features and content of this invention, preferred embodiments will be described in more detail below. While preferred embodiments are described in the examples, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply.

[0068] The testing methods involved are as follows:

[0069] 1. Number-average molecular weight of polyether ester polymers

[0070] The number-average molecular weight was determined using a gel permeation chromatography (EC2000) system. The chromatographic column used was a Shodex GPC KF 802 (size limit 5000, inner diameter 8 mm, length 300 mm); the mobile phase was tetrahydrofuran; and the detector was an RT1230 differential refractive index detector.

[0071] 2. The end-capping ratio of the polyether ester polymer was measured by 1H NMR spectroscopy.

[0072] 3. Mechanical properties of sealant

[0073] The mechanical properties of the sealant were tested in accordance with GB / T 16776 "Silicone Structural Sealants for Buildings" and GB / T 14683 "Silicone and Modified Silicone Building Sealants".

[0074] 4. Heat resistance of the sealant

[0075] The cured sealant is then subjected to heat treatment under the following conditions: temperature of 120°C and time of 168 hours; after that, relevant mechanical property tests are performed according to the method described in point 3 above.

[0076] The sources of the raw materials involved are as follows:

[0077] All polyether polyols used in the examples were self-made products. The preparation methods of each polyether polyol are as follows, depending on the type of catalyst:

[0078] (1) Using DMC bimetallic catalyst process: After mixing the small molecule polyether product with DMC catalyst, the temperature is raised to 130-150℃, and a small amount of PO is added to activate the catalyst. Then, PO is continuously added to react until the product reaches the target molecular weight. After aging for 1 hour, the unreacted PO is removed to obtain the polyether polyol product. The polyether polyols used in Examples 1-3 are prepared according to this method. The small molecule polyether product used is C2004 (i.e., propylene glycol is used as the initiator and PO is used as the polymerization monomer to carry out homopolymerization reaction until the product molecular weight is 400).

[0079] (2) KOH catalyst process: Small molecule polyols (such as glycerol, propylene glycol, sorbitol, etc.) are mixed with KOH and heated to dehydrate. Then, PO or a mixture of PO / EO is slowly added to react until the product reaches the target molecular weight. After aging for 2 hours to remove unreacted PO and / or EO, ​​acid is added to neutralize and crystallize into salt. After removing the catalyst, the polyether polyol product can be obtained. The polyether polyols used in Examples 4-6 were prepared according to this method.

[0080] The two processes for preparing polyether polyols described above are well-known in the industry. By referring to the preparation process described above, polyether polyols of different molecular weights can be prepared according to requirements.

[0081] Itaconic acid, silane, and platinum catalyst were all purchased from Aladdin. Unless otherwise specified, all other raw materials are commercially available.

[0082] Example 1

[0083] The preparation process of polyether ester polymers with curing properties is as follows:

[0084] S1: Add 3950g of polyether polyol-I (propylene glycol as the initiator, PO as the monomer for homopolymerization, molecular weight 6000) and 68g of itaconic acid to a 5L stainless steel polyester reactor. After nitrogen purging three times, raise the temperature to 80℃ to start the atmospheric pressure esterification reaction. Then, raise the temperature to 200℃ within 1 hour and keep the reaction at this temperature for 4 hours to complete the atmospheric pressure esterification reaction. Then, add 20ppm of tetraisopropyl titanate and raise the material temperature to 210℃. Control the system vacuum degree to 2KPaA and react for 7 hours to complete the negative pressure esterification reaction, obtaining 4kg of polyether ester polymer containing double bonds.

[0085] S2: Transfer the polyether ester polymer containing double bonds obtained in step S1 to an addition reactor and add 8 ppm of caster catalyst; control the reaction temperature at 110℃, add 63 g of trimethoxysilane, keep the reaction at this temperature for 4 h, remove unreacted silane monomers under vacuum, cool down to 60℃ and discharge to obtain polyether ester polymer-I with a molecular weight of 30000 and a silane end-capping rate of 95%.

[0086] Preparation of sealant

[0087] 100 parts by weight of the polyether ester polymer-I prepared above, 50 parts by weight of plasticizer (diisononyl phthalate), 90 parts by weight of nano calcium carbonate, 10 parts by weight of thixotropic agent (polyamide wax), 1.5 parts by weight of ultraviolet absorber (Tinuvin 326), and 1.5 parts by weight of antioxidant Irga nox 1076 were added to a high-speed disperser for dispersion and mixing. A large amount of heat was generated during the dispersion process. The temperature was controlled at about 70°C and the dispersion was carried out at a high speed of 5000 rpm for 1 hour to obtain component A.

[0088] 100 parts by weight of plasticizer PPG 3000, 50 parts by weight of nano calcium carbonate CCS 18, 100 parts by weight of heavy calcium carbonate GF 2240, and 40 parts by weight of stannous octoate were added to a high-speed disperser and dispersed at a high speed of 5000 rpm for 1 hour to obtain component B.

[0089] Mix the above-obtained components A and B at a mass ratio of 10:1 until homogeneous, and then cure at room temperature for 48 hours to obtain the sealant.

[0090] Example 2

[0091] The preparation process of polyether ester polymers with curing properties is as follows:

[0092] S1: 3941g of polyether polyol-II (propylene glycol as the initiator, PO as the monomer for homopolymerization, molecular weight 5000) and 81.2g of itaconic acid were added to a 5L stainless steel polyester reactor. After nitrogen purging three times, the temperature was raised to 80℃ to start the atmospheric pressure esterification reaction. Then, the temperature was raised to 190℃ within 1 hour and kept at that temperature for 6 hours to complete the atmospheric pressure esterification reaction. Then, 20ppm of tetraisopropyl titanate was added, and the material temperature was raised to 200℃. The vacuum degree of the system was controlled at 5KPaA, and the reaction was carried out for 4 hours to complete the negative pressure esterification reaction, obtaining 4kg of polyether ester polymer containing double bonds.

[0093] S2: Transfer the polyether ester polymer containing double bonds obtained in step S1 to an addition reactor and add 15 ppm of caster catalyst; control the reaction temperature at 120°C, add 68 g of trimethoxysilane, keep the reaction at this temperature for 2 h, remove unreacted silane monomers under vacuum, cool down to 60°C and discharge the product to obtain polyether ester polymer-II with a molecular weight of 25000 and a silane end-capping rate of 85%.

[0094] Preparation of sealant

[0095] The sealant was prepared according to the process of Example 1, except that polyether ester polymer-II was used instead of polyether ester polymer-I in Example 1.

[0096] Example 3

[0097] The preparation process of polyether ester polymers with curing properties is as follows:

[0098] S1: 3929g of polyether polyol-I (propylene glycol as the initiator, PO as the monomer for homopolymerization, molecular weight 4000) and 98.6g of itaconic acid were added to a 5L stainless steel polyester reactor. After nitrogen purging three times, the temperature was raised to 80℃ to start the atmospheric pressure esterification reaction. Then, the temperature was raised to 120℃ within 1 hour and kept at that temperature for 7 hours to complete the atmospheric pressure esterification reaction. Then, 20ppm of tetraisopropyl titanate was added, and the material temperature was raised to 150℃. The vacuum degree of the system was controlled at 40KPaA, and the reaction was carried out for 6 hours to complete the negative pressure esterification reaction, obtaining 4kg of polyether ester polymer containing double bonds.

[0099] S2: Transfer the polyether ester polymer containing double bonds obtained in step S1 to an addition reactor and add 5 ppm of caster catalyst; control the reaction temperature at 90°C, add 98 g of triethoxysilane, keep the reaction at this temperature for 5 h, remove unreacted silane monomers under vacuum, cool down to 60°C and discharge the product to obtain polyether ester polymer-III with a molecular weight of 18000 and a silane end-capping rate of 75%.

[0100] Preparation of sealant

[0101] The sealant was prepared according to the process of Example 1, except that polyether ester polymer-III was used instead of polyether ester polymer-I in Example 1.

[0102] Example 4

[0103] The preparation process of polyether ester polymers with curing properties is as follows:

[0104] S1: 3903g of polyether polyol-III (glycerol as the initiator, PO / EO as the comonomer for copolymerization, EO content of 15wt%, molecular weight of 3000) and 134.3g of itaconic acid were added to a 5L stainless steel polyester reactor. After nitrogen purging three times, the temperature was raised to 80℃ to start the atmospheric pressure esterification reaction. Then, the temperature was raised to 180℃ within 1 hour and kept at that temperature for 2 hours to complete the atmospheric pressure esterification reaction. Then, 20ppm of tetraisopropyl titanate was added, and the material temperature was raised to 200℃. The vacuum degree of the system was controlled at 3KPaA, and the reaction was carried out for 2 hours to complete the negative pressure esterification reaction, obtaining 4kg of polyether ester polymer containing double bonds.

[0105] S2: Transfer the polyether ester polymer containing double bonds obtained in step S1 to an addition reactor and add 20 ppm of chloroplatinic acid; control the reaction temperature at 50°C, add 79 g of methyldimethoxysilane, keep the reaction at this temperature for 4 h, remove the unreacted silane monomers under vacuum, and discharge the product to obtain a polyether ester polymer-IV with a molecular weight of 15000 and a silane end-capping rate of 65%.

[0106] Preparation of sealant

[0107] The sealant was prepared according to the process of Example 1, except that polyether ester polymer-IV was used instead of polyether ester polymer-I in Example 1.

[0108] Example 5

[0109] The preparation process of polyether ester polymers with curing properties is as follows:

[0110] S1: 3840g of polyether polyol-V (propylene glycol as the initiator, PO as the monomer for homopolymerization, molecular weight 2000) and 208.2g of itaconic acid were added to a 5L stainless steel polyester reactor. After nitrogen purging three times, the temperature was raised to 80℃ to start the atmospheric pressure esterification reaction. Then, the temperature was raised to 190℃ within 1 hour and kept at that temperature for 5 hours to complete the atmospheric pressure esterification reaction. Then, 20ppm of tetraisopropyl titanate was added, and the material temperature was raised to 200℃. The vacuum degree of the system was controlled at 15KPaA, and the reaction was carried out for 6 hours to complete the negative pressure esterification reaction, obtaining 4kg of polyether ester polymer containing double bonds.

[0111] S2: The polyether ester polymer containing double bonds obtained in step S1 is transferred to an addition vessel and 8 ppm of chloroplatinic acid catalyst is added; the reaction temperature is controlled at 80°C, 127 g of methyldimethoxysilane is added, the reaction is kept at this temperature for 2 h, and the unreacted silane monomer is removed under vacuum before discharging to obtain a polyether ester polymer-V with a molecular weight of 13000 and a silane end-capping rate of 72%.

[0112] Preparation of sealant

[0113] The sealant was prepared according to the process of Example 1, except that polyether ester polymer-V was used instead of polyether ester polymer-I in Example 1.

[0114] Example 6

[0115] The preparation process of polyether ester polymers with curing properties is as follows:

[0116] S1: Add 3857g of polyether polyol-VI (ethylene glycol as the initiator, PO / EO as the comonomer for copolymerization, EO content of 35wt%, molecular weight of 2000) and 198g of itaconic acid to a 5L stainless steel polyester reactor. After nitrogen purging three times, raise the temperature to 80℃ to start the atmospheric pressure esterification reaction. Then, raise the temperature to 150℃ within 1 hour and keep the reaction at this temperature for 4 hours to complete the atmospheric pressure esterification reaction. Then, add 20ppm of tetraisopropyl titanate and raise the material temperature to 160℃. Control the system vacuum degree to 10KPaA and react for 7 hours to complete the negative pressure esterification reaction, obtaining 4kg of polyether ester polymer containing double bonds.

[0117] S2: Transfer the polyether ester polymer containing double bonds obtained in step S1 to an addition reactor and add 2 ppm of caster catalyst; control the reaction temperature at 70°C, add 105 g of methyldimethoxysilane, keep the reaction at this temperature for 5 h, remove unreacted silane monomers under vacuum and discharge the product to obtain a polyether ester polymer-VI with a molecular weight of 10000 and a silane end-capping rate of 60%.

[0118] Preparation of sealant

[0119] The sealant was prepared according to the process of Example 1, except that polyether ester polymer-VI was used instead of polyether ester polymer-I in Example 1.

[0120] Example 7

[0121] The preparation process of polyether ester polymers with curing properties is as follows:

[0122] S1: 3714g of polyether polyol-VII (sorbitol as the initiator, PO / EO as the comonomer for copolymerization, EO content of 20%, molecular weight of 1000) and 395g of itaconic acid were added to a 5L stainless steel polyester reactor. After nitrogen purging three times, the temperature was raised to 80℃ to start the atmospheric pressure esterification reaction. Then, the temperature was raised to 120℃ within 1 hour and kept at that temperature for 8 hours to complete the atmospheric pressure esterification reaction. Then, 20ppm of tetraisopropyl titanate was added, and the material temperature was raised to 180℃. The vacuum degree of the system was controlled at 20KPaA, and the reaction was carried out for 8 hours to complete the negative pressure esterification reaction, obtaining 4kg of polyether ester polymer containing double bonds.

[0123] S2: The polyether ester polymer containing double bonds obtained in step S1 is transferred to an addition vessel and 12 ppm of chloroplatinic acid catalyst is added; the reaction temperature is controlled at 80°C, 224 g of methyldiethoxysilane is added, the reaction is kept at this temperature for 3 h, and the unreacted silane monomer is removed under vacuum before the product is discharged to obtain a polyether ester polymer-VII with a molecular weight of 6000 and a silane end-capping rate of 50%.

[0124] Preparation of sealant

[0125] The sealant was prepared according to the process of Example 1, except that polyether ester polymer-VII was used instead of polyether ester polymer-I in Example 1.

[0126] Comparative Example 1

[0127] The preparation process of polyether ester polymers is as follows:

[0128] S1: 3778g of polyether polyol-V (propylene glycol as the initiator, PO as the monomer for homopolymerization, molecular weight 2000) and 231.3g of itaconic acid were added to a 5L stainless steel polyester reactor. After nitrogen purging three times, the temperature was raised to 80℃ to start the atmospheric pressure esterification reaction. Then, the temperature was raised to 200℃ within 1 hour and kept at that temperature for 7 hours to complete the atmospheric pressure esterification reaction. Then, 40ppm of tetraisopropyl titanate was added, and the material temperature was raised to 210℃. The vacuum degree of the system was controlled at 10KPaA, and the reaction was carried out for 7 hours to complete the negative pressure esterification reaction, obtaining 4kg of polyether ester polymer containing double bonds.

[0129] S2: The polyether ester polymer containing double bonds obtained in step S1 is transferred to an addition vessel, and 12 ppm of chloroplatinic acid catalyst is added; the reaction temperature is controlled at 100℃, 155 g of methyldimethoxysilane is added, the reaction is kept at this temperature for 5 h, and the unreacted silane monomer is removed under vacuum before discharging to obtain a polyether ester polymer-I' with a molecular weight of 36000 and a silane end-capping rate of 72%.

[0130] Preparation of sealant

[0131] The sealant was prepared according to the process of Example 1, except that polyether ester polymer-I' was used instead of polyether ester polymer-I in Example 1.

[0132] Comparative Example 2

[0133] The preparation process of polyether ester polymers is as follows:

[0134] S1: 3874g of polyether polyol-V (propylene glycol as the initiator, PO as the monomer for homopolymerization, molecular weight 2000) and 126g of itaconic acid were added to a 5L stainless steel polyester reactor. After nitrogen purging three times, the temperature was raised to 80℃ to start the atmospheric pressure esterification reaction. Then, the temperature was raised to 170℃ within 1 hour and kept at that temperature for 5 hours to complete the atmospheric pressure esterification reaction. Then, 15ppm of tetraisopropyl titanate was added, and the material temperature was raised to 200℃. The vacuum degree of the system was controlled at 15KPaA, and the reaction was carried out for 6 hours to complete the negative pressure esterification reaction, obtaining 4kg of polyether ester polymer containing double bonds.

[0135] S2: The polyether ester polymer containing double bonds obtained in step S1 is transferred to an addition vessel and 7 ppm of chloroplatinic acid catalyst is added; the reaction temperature is controlled at 90°C, 77 g of methyldimethoxysilane is added, the reaction is kept at this temperature for 3 h, and the unreacted silane monomer is removed under vacuum before the product is discharged to obtain a polyether ester polymer-II' with a molecular weight of 4300 and a silane end-capping rate of 72%.

[0136] Preparation of sealant

[0137] The sealant was prepared according to the process of Example 1, except that polyether ester polymer-II' was used instead of polyether ester polymer-I in Example 1.

[0138] Comparative Example 3

[0139] Preparation of sealant

[0140] The sealant was prepared according to the process of Example 1, except that Zhongyuan S203H (silane-modified polyether) was used instead of polyether ester polymer-I in Example 1.

[0141] The sealants obtained in Examples 1 to 7 and Comparative Examples 1 to 3 were subjected to mechanical property tests and heat resistance tests according to the aforementioned method. The results are shown in Tables 1 to 2.

[0142] Table 1. Test results of mechanical properties of the sealant

[0143] sample Tensile strength / MPa 100% Modulus / MPa Elongation at break % Shaw Brothers A Example 1 0.67 0.23 467 18 Example 2 0.74 0.35 436 22 Example 3 1.58 0.88 412 33 Example 4 1.79 1.19 405 41 Example 5 1.88 1.22 385 44 Example 6 2.07 1.45 352 48 Example 7 2.86 1.83 245 57 Comparative Example 1 0.55 0.22 198 12 Comparative Example 2 3.53 2.56 189 63 Comparative Example 3 1.82 1.14 367 42

[0144] Table 2. Test results of heat resistance of sealant

[0145]

[0146]

[0147] According to the results in Table 1, the number-average molecular weights of the polyether ester polymers in Examples 1 to 7 are 30,000, 25,000, 18,000, 15,000, 13,000, 10,000, and 6,000, respectively. The mechanical properties of the sealant are related to the molecular weight of the polyether ester polymer. When the molecular weight of the polyether ester polymer is controlled within a suitable range, the mechanical properties of the corresponding sealant are close to those of the sealant prepared using S203H. Among them, the molecular weight of the polyether ester polymer in Example 5 is basically the same as that of S203H in Comparative Example 3, and its properties are also closest to those of S203H. The mechanical properties of the sealants obtained in Example 5 and Comparative Example 3 are similar, and the heat resistance of the sealant in Example 5 is better than that in Comparative Example 3. This shows that the sealant prepared by the polyether ester polymer in this invention can replace the sealant prepared by S203H, while avoiding the defect of poor heat resistance caused by the ether bonds in the molecular chain of S203H. The polyether ester polymer structure selected in this invention introduces ester bonds, which can effectively improve the long-term heat resistance of sealant products. At the same time, it can also ensure that the reaction conditions are relatively mild and the production process is safe and environmentally friendly, thus having industrial feasibility.

[0148] Although polyether ester polymers were also used in Comparative Examples 1-2, their molecular weight was not controlled within a suitable range. Compared with Examples 1-7, the mechanical properties of the sealant obtained in Comparative Examples 1-2 decreased significantly after heat treatment, and its long-term heat resistance was poor.

[0149] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the spirit of the invention.

Claims

1. A polyether ester polymer, characterized in that, The polyether ester polymer has a number-average molecular weight of 6000–30000; and, A polyether polyol is mixed with itaconic acid and subjected to an esterification reaction to obtain a polyether ester containing double bonds; then the polyether ester containing double bonds is reacted with an alkoxysilane to end the double bonds, thereby obtaining the polyether ester polymer; wherein the molecular weight of the polyether polyol is 1000-6000.

2. The polyether ester polymer according to claim 1, characterized in that, The number-average molecular weight of the polyether ester polymer is 10,000 to 18,000.

3. A method for preparing a polyether ester polymer, characterized in that, Includes the following steps: S1: Polyether polyol and itaconic acid are mixed and subjected to esterification reaction to prepare polyether ester containing double bonds; S2: The polyether ester containing double bonds is reacted with alkoxysilane to end the double bonds, thereby obtaining the polyether ester polymer; in, The polyether polyol has a molecular weight of 1000-6000, and the initiator used in the polyether polyol is a small molecule alcohol and / or water; the epoxy compound used in the polyether polyol is a C2-C5 epoxy compound.

4. The preparation method according to claim 3, characterized in that, The initiator used in the polyether polyol is selected from one or more of water, glycerol, trimethylolpropane, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, pentaerythritol, and sorbitol.

5. The preparation method according to claim 3, characterized in that, The epoxy compound used in the polyether polyol is selected from one or more of ethylene oxide, propylene oxide, and butyl oxide.

6. The preparation method according to claim 3, characterized in that, The reaction in step S1 includes an atmospheric pressure esterification reaction stage and a negative pressure esterification reaction stage; The process conditions for the atmospheric pressure esterification reaction stage include: a reaction temperature of 120–200°C and a reaction time of 2–8 hours. The process conditions for the negative pressure esterification reaction stage include: reaction temperature of 150–210℃; reaction time of 2–8 h; and negative pressure of 2–40 kPaA. The catalyst used in the negative pressure esterification reaction stage is a titanium-based catalyst.

7. The preparation method according to claim 6, characterized in that, The process conditions for the atmospheric pressure esterification reaction stage in step S1 include: a reaction temperature of 150–180°C and a reaction time of 4–7 h.

8. The preparation method according to claim 6, characterized in that, The process conditions for the negative pressure esterification reaction stage in step S1 include: a reaction temperature of 170–200°C; a reaction time of 4–7 h; and a negative pressure of 5–15 kPaA.

9. The preparation method according to claim 6, characterized in that, The catalyst used in the negative pressure esterification reaction stage in step S1 is selected from tetrabutyl titanate and tetraisopropyl titanate.

10. The preparation method according to any one of claims 3-9, characterized in that, The alkoxysilane is selected from one or more of methyldimethoxysilane, methyldiethoxysilane, trimethoxysilane, and triethoxysilane; in the polyether ester polymer, the end-capping rate of the alkoxysilane is 50-95%.

11. The preparation method according to any one of claims 3-9, characterized in that, The reaction in step S2 is carried out in the presence of a platinum-based catalyst; The platinum-based catalyst is selected from cassiterite catalysts and / or chloroplatinic acid catalysts; The amount of the platinum-based catalyst used is 2 to 20 ppm of the total mass of the reactants in step S2, wherein the amount of the platinum-based catalyst is based on the mass of Pt. The reaction conditions for step S2 include: a reaction temperature of 50–120°C and a reaction time of 0.5–5 h.

12. The preparation method according to claim 11, characterized in that, The amount of platinum-based catalyst used in step S2 is 5 to 10 ppm of the total mass of the reactants in step S2, wherein the amount of platinum-based catalyst is based on the mass of Pt.

13. The preparation method according to claim 11, characterized in that, The reaction conditions for step S2 include: a reaction temperature of 60–100°C and a reaction time of 2–4 hours.

14. The use of the polyether ester polymer as described in claim 1 or 2, or the polyether ester polymer prepared by any one of claims 3-13, in the preparation of sealants.

15. A sealant composition, characterized in that, include: Component A and Component B; Component A includes the polyether ester polymer of claim 1 or 2 or the polyether ester polymer prepared by any one of claims 3-13; Component B includes a catalyst, wherein the catalyst is an organotin compound.

16. The sealant composition according to claim 15, characterized in that, The catalyst is selected from dibutyltin dilaurate, dioctyltin diacetate, stannous octoate, and organotin bis(β-dibutyltin dilaurate). One or more of the following: diketone esters.

17. The sealant composition according to claim 16, characterized in that, The catalyst is stannous octoate.

18. The sealant composition according to claim 15, characterized in that, Component A further includes one or more of the following: a first plasticizer, nano-calcium carbonate, a thixotropic agent, a UV absorber, and an antioxidant; Component B also includes one or more of a second plasticizer, nano-calcium carbonate, and heavy calcium carbonate.

19. The sealant composition according to claim 18, characterized in that, The weight proportions of each raw material in component A are as follows: Polyether ester polymer, 100 parts First plasticizer, 40-60 parts Nano calcium carbonate, 60-100 parts Thixotropic agent, 5-15 parts UV absorber, 0.5-2 parts. Antioxidant, 0.5-2 parts; The weight proportions of each raw material in component B are as follows: Second plasticizer, 100 parts Nano calcium carbonate, 40-60 parts Triple calcium, 80-120 servings Catalyst, 30-50 parts.

20. A sealant, characterized in that, Formed by the sealant composition as described in any one of claims 15-19.

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