High temperature resistant and hydrolysis resistant polyurethane polishing wheel and preparation method thereof

Abstract

The present invention belongs to the technical field of polyurethane polishing abrasive tools, and specifically relates to a high temperature resistant and hydrolysis resistant polyurethane polishing wheel and a preparation method thereof. The high temperature resistant and hydrolysis resistant polyurethane polishing wheel is prepared by reacting three components A, B and C, wherein the A component comprises polyether polyol X, polymer polyol, chain extender, crosslinker, catalyst and foaming agent; the B component comprises polyether polyol Y, 4,4'-MDI, MDI-50, carbodiimide modified MDI, polymethylene polyphenyl polyisocyanate and cell opener, and the C component is an inorganic filler; the polyether polyol X organically combines ester bonds, ether bonds and Si-O-Si segments, which can take into account the advantages of polyether polyols and polyester polyols, and can effectively solve the problem of poor storage stability of downstream applications caused by the immiscibility of polyether polyols and polyester polyols, and the introduction of Si-O-Si segments can improve the high temperature resistance and hydrolysis resistance of polyurethane foam.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane polishing abrasive tools, and in particular relates to a high-temperature resistant and hydrolysis resistant polyurethane polishing wheel and a preparation method thereof. Background Art

[0002] Polyurethane materials have good application prospects in the field of grinding and polishing due to their high hardness, high wear resistance and chemical resistance, excellent mechanical properties and elasticity. As the base material of polyurethane polishing abrasives, the structure and properties of polyurethane materials have a decisive influence on the performance of abrasives. Since polyurethane materials contain groups with poor heat resistance such as allophanate, biuret, and ether bonds, they themselves have the defect of poor heat resistance. Since the polishing wheel contacts the polished workpiece when rotating at high speed, a large amount of heat is generated. If the heat resistance of the polyurethane polishing wheel is poor, the surface of the workpiece will appear sticky and black after polishing. Common modification methods include physical modification and chemical modification. Physical modification is to add certain fillers or additives in the process of preparing polyurethane polishing wheels by certain methods, thereby changing certain properties of polyurethane polishing wheels. One of the disadvantages of this method is poor storage stability; chemical modification is to change the type of atoms or atomic groups on the polyurethane molecular chain by chemical reaction or simple blending.

[0003] Chinese patent CN117024701A discloses a polyurethane foam polishing material and its preparation method and application. Its technical solution includes component A, component B and component C. Component A includes polyether polyol, chain extender, foaming agent, catalyst, component B is isocyanate prepolymer, and component C includes polishing powder and dispersant. Although the polyurethane foam polishing material provided by the invention claims to have good hydrolysis resistance, little temperature influence, and good flexibility, the invention does not have specific data to reflect the hydrolysis resistance. The heat resistance of ordinary polyether polyurethane polishing materials is generally poor, and the invention uses a large amount of polytetramethylene ether glycol, which is costly.

[0004] Chinese patent CN116444977A discloses a polyurethane elastomer and a method for preparing a polishing abrasive block using the same. The technical solution includes three components: A, B, and C. Component A is a small molecule chain extender, a flame retardant, a hydrated silicate, a coupling agent, a defoamer, an anti-settling agent, and a catalyst; Component B is a polyether polyol, an isocyanate, and a viscosity reducer; Component C is silicon micropowder, corundum, and sand. The polyurethane elastomer of the invention has low viscosity, is easy to mix after mixing abrasives, does not require high-temperature heating for preforming, and has a fast maturation speed. However, the invention is ultimately an elastomer with high hardness and poor resilience. It is only suitable for objects with flat surfaces that need to be finely polished, and is not suitable for polishing objects with uneven surfaces, so its application range is limited. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a high temperature resistant and hydrolysis resistant polyurethane polishing wheel. The molecular structure of the polyether polyol is designed, and the ester bond, ether bond and Si-O-Si segment are organically combined for use in a polyurethane polishing wheel. The polyurethane polishing wheel has high storage stability, and the product has good flexibility, high heat resistance and strong hydrolysis resistance.

[0006] The invention also provides a preparation method thereof, which has simple process and high production efficiency.

[0007] The high temperature resistant and hydrolysis resistant polyurethane polishing wheel of the present invention is prepared by reacting three components A, B and C, and the mass ratio of the three components A, B and C is 1: (0.85-1.33): (1.5-1.9);

[0008] Wherein, the component A comprises the following raw materials in parts by weight: polyether polyol X: 50-70 parts, polymer polyol: 30-50 parts, chain extender: 20-40 parts, cross-linking agent: 3-40 parts, catalyst: 0.21-0.85 parts, foaming agent: 8.5-16 parts;

[0009] The component B is composed of the following raw materials in parts by weight: polyether polyol Y: 20-36.5 parts, 4,4'-MDI: 38.5-50.5 parts, MDI-50: 19-25.5 parts, carbodiimide modified MDI: 1.8-2.2 parts, polymethylene polyphenyl polyisocyanate: 1.0-3.6 parts, and pore opener: 0.6-1.4 parts;

[0010] The C component is an inorganic filler;

[0011] The polyether polyol X is a high molecular weight and high activity polyether polyol with a functionality of 3 to 6 and a number average molecular weight of 5000 to 15000 g / mol, and the polyether segment contains an ester bond, an ether bond, and a Si-O-Si bond;

[0012] The functionality of the polyether polyol Y is 3-6, and the number average molecular weight is 5000-12000 g / mol. Preferably, it is one or more of INOVOL F330N, INOVOL F3600, INOVOL F822, and INOVOL F628 of Shandong Yinuowei New Materials Co., Ltd.

[0013] The component A may be added with other additives according to performance requirements, such as antioxidants, plasticizers, dyes, pigments, etc.

[0014] The polyether polyol X is prepared from an initiator and a polymerization monomer under the action of a catalyst. The initiator is a compound of one of sorbitol, pentaerythritol, xylitol, mannitol, and sucrose and castor oil. The catalyst is a phosphazene catalyst. The polymerization monomers are propylene oxide, ethylene oxide, and cyclosiloxane, and the mass ratio of the three is (6.6-17.8):(1-3):1.

[0015] The cyclosiloxane is one of hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6) and dimethylsiloxane mixed ring (DMC).

[0016] The preparation method of the polyether polyol X is as follows: adding an initiator and a phosphazene catalyst into a pressure-resistant reactor and mixing them, replacing with nitrogen to make the oxygen content in the reactor less than 50 ppm, heating to 90-105° C., vacuum dehydration for 1-2 hours, continuously dropping propylene oxide and cyclosiloxane at 90-105° C. for ring-opening polymerization, continuing the internal pressure reaction for 1-2 hours after the reaction is completed, vacuuming to remove unreacted alkylene oxide monomers and small molecular by-products, and then continuously dropping ethylene oxide at 115-125° C. for ring-opening polymerization, continuing the internal pressure reaction for 1-2 hours after the reaction is completed, vacuuming to remove unreacted alkylene oxide monomers and small molecular by-products, and then adding an acidic regulator and an adsorbent for neutralization and adsorption, and then drying and filtering to obtain the polyether polyol X.

[0017] The polymer polyol is a highly active polymer polyol with a solid content of 23-32%, preferably one of POP93 / 28 and POP36 / 28 of Shandong Bluestar Dongda Chemical Co., Ltd. and POP-36 / 30 of Wudi Dexin Chemical Co., Ltd.

[0018] The chain extender is an alcohol chain extender, preferably a mixture of one or more of 1,4-butanediol, ethylene glycol, diethylene glycol, 1,6-hexanediol, and hydroquinone dihydroxyethyl ether (HQEE); the cross-linking agent is an amine cross-linking agent; and the catalyst is a mixture of an amine catalyst and an organic metal catalyst in a mass ratio of (12-27):1.

[0019] The amine crosslinking agent is a mixture of one or more of diethanolamine, triethanolamine and a low molecular weight polyether polyol with an amine substance as an initiator. The number average molecular weight of the low molecular weight polyether polyol with an amine substance as an initiator is 300-1500 g / mol, preferably one of INOVOL R403, INOVOL R405 and INOVOLF414 produced by Shandong Yinuowei New Materials Co., Ltd.

[0020] The amine catalyst is a mixture of one or more of triethylenediamine, bis(dimethylaminoethyl) ether, pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, tetramethylpropylenediamine, and bismorpholinyldiethyl ether; the organic metal catalyst is one of dibutyltin dilaurate, stannous octoate, dibutyltin dimercaptoacetate, dioctyltin mercaptan, and bismuth isooctanoate.

[0021] The foaming agent is a mixture of a physical foaming agent and a chemical foaming agent, which can play a dual role of cross-linking and foaming to improve mechanical strength. The mass ratio of the physical foaming agent to the chemical foaming agent is (8-37.5):1, the physical foaming agent is a mixture of one or more of HCFC-141b, dichloromethane, and HFC-245fa, and the chemical foaming agent is one of ammonia water and water.

[0022] The pore opening agent is preferably one of INOVOL S350T, INOVOL S25K, INOVOL F8001A and INOVOL F8001B produced by Shandong Yinuowei New Materials Co., Ltd.

[0023] The inorganic filler is a mixture of one or more of nano silicon dioxide, silicon carbide, corundum and cubic boron carbide.

[0024] The preparation method of the high temperature resistant and hydrolysis resistant polyurethane polishing wheel of the present invention comprises the following steps:

[0025] (1) Preparation of component A: Add polyether polyol X and polymer polyol into a reaction kettle and stir at room temperature, then add chain extender, cross-linking agent, catalyst and foaming agent, stir at room temperature for 1-2 hours, and seal for storage;

[0026] (2) Preparation of component B: put polyether polyol Y into a reactor at room temperature, stir and heat to 90-100°C, dehydrate and degas under vacuum conditions for 2-3 hours, cool down, add 4,4'-MDI, MDI-50, and carbodiimide-modified MDI, heat to 80-85°C and react for 2-3 hours, add polymethylene polyphenyl isocyanate and pore-opening agent and stir for 30 minutes, test the -NCO content to be between 20-26wt.%, cool down, and seal for storage;

[0027] (3) When in use, component A, component B and component C are mixed evenly, then poured into a mold, and aged at 80° C. for 8 hours to obtain the high temperature resistant and hydrolysis resistant polyurethane polishing wheel.

[0028] The cooling in step (2) is to cool the temperature to 40-50°C.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1) The high temperature and hydrolysis resistant polyurethane polishing wheel of the present invention adopts a high molecular weight and high activity polyether polyol prepared by castor oil and a high functionality initiator, and polymerizes cyclosiloxane, propylene oxide and ethylene oxide in the molecular chain segment, and organically combines ester bonds, ether bonds and Si-O-Si segments, which can take into account the advantages of polyether polyols and polyester polyols, and can effectively solve the problem of poor storage stability in downstream applications caused by the immiscibility of polyether polyols and polyester polyols. At the same time, the introduction of Si-O-Si segments can improve the high temperature resistance and hydrolysis resistance of polyurethane foam.

[0031] 2) The high temperature and hydrolysis resistant polyurethane polishing wheel described in the present invention, component A and component B adopt high functionality and high molecular weight polyether polyols, which can not only improve the chemical crosslinking density inside the polyurethane foam, but also give the formula system sufficient crosslinking curing speed and post-ripening speed, thereby solving the problem of slow crosslinking curing and aging speed of the polyurethane foam, effectively improving the product's resistance to moisture and heat aging, and at the same time making the product have good flexibility, effectively increasing the service life.

[0032] 3) The preparation method of the high temperature resistant and hydrolysis resistant polyurethane polishing wheel of the present invention has simple process, convenient operation and high production efficiency. DETAILED DESCRIPTION

[0033] The present invention will be further described below with reference to the embodiments.

[0034] Unless otherwise specified, all raw materials used in the examples are commercially available.

[0035] Some of the raw materials used in the examples and comparative examples are described as follows:

[0036] INOVOL F330N, commercially available from Shandong Yinuowei New Materials Co., Ltd. (functionality 3, number average molecular weight 5000 g / mol);

[0037] INOVOL F3600, commercially available from Shandong Yinuowei New Materials Co., Ltd. (functionality 3, number average molecular weight 6000 g / mol);

[0038] INOVOL F822, commercially available from Shandong Yinuowei New Materials Co., Ltd. (functionality 3, number average molecular weight 7500 g / mol);

[0039] INOVOL F628, commercially available from Shandong Yinuowei New Materials Co., Ltd. (functionality 6, number average molecular weight 12000 g / mol);

[0040] INOVOL R403, commercially available from Shandong Yinuowei New Materials Co., Ltd. (functionality 4, number average molecular weight 300 g / mol);

[0041] INOVOL R405, commercially available from Shandong Yinuowei New Materials Co., Ltd. (functionality 4, number average molecular weight 500 g / mol);

[0042] INOVOL F414, commercially available from Shandong Yinuowei New Materials Co., Ltd. (functionality 4, number average molecular weight 1450 g / mol);

[0043] INOVOL S350T, commercially available from Shandong Yinuowei New Materials Co., Ltd.;

[0044] INOVOL S25K, commercially available from Shandong Yinuowei New Materials Co., Ltd.;

[0045] INOVOL F8001A, commercially available from Shandong Yinuowei New Materials Co., Ltd.;

[0046] INOVOL F8001B, commercially available from Shandong Yinuowei New Materials Co., Ltd.;

[0047] POP93 / 28, commercially available from Shandong Bluestar Dongda Chemical Co., Ltd.;

[0048] POP36 / 28, commercially available from Shandong Bluestar Dongda Chemical Co., Ltd.;

[0049] POP-36 / 30, commercially available from Wudi Dexin Chemical Co., Ltd.;

[0050] Phosphazene catalyst, phosphazene salt catalyst from Mitsui Chemicals, Japan;

[0051] Ammonia water, concentration 25wt.%;

[0052] POL-1276, commercially available from Qingdao Xinyutian Chemical Co., Ltd.;

[0053] Polymethylene polyphenyl isocyanate: PM-200, commercially available from Yantai Wanhua;

[0054] Preparation of polyether polyol X1: 280.4 kg of castor oil, 12.3 kg of pentaerythritol, and 2 kg of phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 90° C. for dehydration for 2 h. 1424 kg of propylene oxide and 80 kg of hexamethylcyclotrisiloxane were slowly added dropwise at 90° C., and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 2 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was raised to 115° C., 200 kg of ethylene oxide was slowly added dropwise, and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 1 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was lowered to 85° C., 0.5 kg of phosphoric acid and 4 kg of magnesium silicate were added in sequence. After dehydration and filtration, the target polyether polyol X1 was obtained. The hydroxyl value was 33.6 mgKOH / g, the functionality was 3, and the number average molecular weight was 5009 g / mol.

[0055] Preparation of polyether polyol X2: 98.7 kg of castor oil, 21 kg of xylitol, and 2 kg of phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 100° C. for dehydration for 1.5 h. 1481 kg of propylene oxide and 100 kg of decamethylcyclopentasiloxane were slowly added dropwise at 100° C., and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 2 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was raised to 120° C., 300 kg of ethylene oxide was slowly added dropwise, and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 1 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was lowered to 85° C., 0.5 kg of phosphoric acid and 4 kg of magnesium silicate were added in sequence. After dehydration and filtration, the target polyether polyol X2 was obtained. The hydroxyl value was 28.1 mgKOH / g, the functionality was 4, and the number average molecular weight was 7986 g / mol.

[0056] Preparation of polyether polyol X3: 82.1 kg of castor oil, 19.2 kg of sorbitol, and 2 kg of phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 95° C. for dehydration for 1 h. 1398 kg of propylene oxide and 200 kg of octamethylcyclotetrasiloxane were slowly added dropwise at 95° C., and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 2 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was raised to 125° C., 300 kg of ethylene oxide was slowly added dropwise, and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 1 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was lowered to 85° C., 0.5 kg of phosphoric acid and 4 kg of magnesium silicate were added in sequence. After dehydration and filtration, the target polyether polyol X3 was obtained. The hydroxyl value was 25.2 mgKOH / g, the functionality was 4.5, and the number average molecular weight was 10018 g / mol.

[0057] Preparation of polyether polyol X4: 45.1 kg of castor oil, 20.3 kg of mannitol, and 2 kg of phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 105° C. for dehydration for 1.5 h. 1330 kg of propylene oxide and 200 kg of dodecamethylcyclohexasiloxane were slowly added dropwise at 105° C., and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 2 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was raised to 125° C., 400 kg of ethylene oxide was slowly added dropwise, and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 1 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was lowered to 85° C., 0.5 kg of phosphoric acid and 4 kg of magnesium silicate were added in sequence. After dehydration and filtration, the target polyether polyol X4 was obtained. The hydroxyl value was 23.4 mgKOH / g, the functionality was 5, and the number average molecular weight was 11987 g / mol.

[0058] Preparation of polyether polyol X5: 44.9 kg castor oil, 27.3 kg sucrose, and 2 kg phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 95° C. for dehydration for 2 h. 1525 kg propylene oxide and 200 kg dimethylsiloxane mixed ring were slowly added dropwise at 95° C., and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 2 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was raised to 120° C., 200 kg ethylene oxide was slowly added dropwise, and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 1 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was lowered to 85° C., 0.5 kg phosphoric acid and 4 kg magnesium silicate were added in sequence. After dehydration and filtration, the target polyether polyol X5 was obtained. The hydroxyl value was 22.5 mg KOH / g, the functionality was 6, and the number average molecular weight was 14960 g / mol.

[0059] Preparation of polyether polyol X6: 82.1 kg of castor oil, 19.2 kg of sorbitol, and 2 kg of phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 95° C. for dehydration for 1 h. 1598 kg of propylene oxide was slowly added dropwise at 95° C., and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 2 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was raised to 125° C., 300 kg of ethylene oxide was slowly added dropwise, and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 1 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was lowered to 85° C., 0.5 kg of phosphoric acid and 4 kg of magnesium silicate were added in sequence. After dehydration and filtration, the target polyether polyol X6 was obtained. The hydroxyl value was 25.0 mgKOH / g, the functionality was 4.5, and the number average molecular weight was 10098 g / mol.

[0060] Preparation of polyether polyol X7: 35.3 kg of sorbitol and 2 kg of phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 95° C. for dehydration for 1 h. 1463 kg of propylene oxide and 200 kg of octamethylcyclotetrasiloxane were slowly added dropwise at 95° C., and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 2 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was raised to 125° C., 300 kg of ethylene oxide was slowly added dropwise, and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 1 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was lowered to 85° C., 0.5 kg of phosphoric acid and 4 kg of magnesium silicate were added in sequence. After dehydration and filtration, the target polyether polyol X7 was obtained. The hydroxyl value was 33.8 mg KOH / g, the functionality was 6, and the number average molecular weight was 9959 g / mol.

[0061] Preparation of polyether polyol X8: 368.3 kg of castor oil and 2 kg of phosphazene catalyst were added to a pressure-resistant reactor. After nitrogen replacement for 3 times, the temperature was raised to 95° C. for dehydration for 1 h. 1132 kg of propylene oxide and 200 kg of octamethylcyclotetrasiloxane were slowly added dropwise at 95° C., and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 2 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was raised to 125° C., 300 kg of ethylene oxide was slowly added dropwise, and the pressure during the reaction was controlled to be less than 0.30 MPa. After the reaction was completed, the internal pressure reaction was continued for 1 h. Vacuum was applied to remove the unreacted residual monomers. The temperature was lowered to 85° C., 0.5 kg of phosphoric acid and 4 kg of magnesium silicate were added in sequence. After dehydration and filtration, the target polyether polyol X8 was obtained. The hydroxyl value was 30.2 mgKOH / g, the functionality was 2.7, and the number average molecular weight was 5016 g / mol.

[0062] Example 1

[0063] The preparation method of the high temperature resistant and hydrolysis resistant polyurethane polishing wheel comprises the following steps:

[0064] (1) Preparation of component A: 60 kg of polyether polyol X1 and 40 kg of POP36 / 28 were weighed and put into a reactor at room temperature, and stirred at a speed of 100 r / min. Then, 16 kg of 1,4-butanediol, 14 kg of ethylene glycol, 3 kg of diethanolamine, 0.7 kg of ammonia water, 0.3 kg of triethylenediamine, 0.05 kg of pentamethyldiethylenetriamine, 0.02 kg of dibutyltin dilaurate, and 12 kg of HCFC-141b were added, and stirred at room temperature for 1 h. The mixture was fully mixed and sealed for storage.

[0065] (2) Preparation of component B: Add 28 kg of INOVOL F628 into a reactor at room temperature, stir and heat to 95±5°C, dehydrate and degas for 2 h under a vacuum condition of less than -0.088 MPa, cool to 45±5°C, add 45 kg of 4,4'-MDI, 22.5 kg of MDI-50 and 2.2 kg of carbodiimide-modified MDI, react at 82±2.5°C for 2 h, add 1.3 kg of PM-200 and 1 kg of INOVOL S350T, stir for 30 min, take samples for testing, and the measured -NCO concentration is 23.1 wt.%. After passing the test, cool to 45±5°C and seal for storage.

[0066] Component C is silicon carbide.

[0067] (3) When in use, the temperature of components A, B and C is maintained at 30±5°C. Components A, B and C are quickly mixed in a mass ratio of 1:1.33:1.71, poured into a mold, and aged at 80°C for 8 hours to obtain the high temperature resistant and hydrolysis resistant polyurethane polishing wheel.

[0068] Example 2

[0069] The preparation method of the high temperature resistant and hydrolysis resistant polyurethane polishing wheel comprises the following steps:

[0070] (1) Preparation of component A: 50 kg of polyether polyol X2 and 50 kg of POP93 / 28 were weighed and put into a reactor at room temperature, and stirred at a speed of 100 r / min. Then, 20 kg of diethylene glycol, 5 kg of triethanolamine, 0.4 kg of water, 0.6 kg of bis(dimethylaminoethyl) ether, 0.2 kg of tetramethylpropylenediamine, 0.03 kg of stannous octoate, and 15 kg of dichloromethane were added. The mixture was stirred at room temperature for 1 h, mixed thoroughly, and sealed for storage.

[0071] (2) Preparation of component B: Add 36.5 kg of INOVOL F330N into a reactor at room temperature, stir and heat to 95±5°C, dehydrate and degas for 2 h under a vacuum degree lower than -0.088 MPa, cool to 45±5°C, add 38.5 kg of 4,4'-MDI, 19 kg of MDI-50 and 1.8 kg of carbodiimide-modified MDI, react at 82±2.5°C for 2.5 h, add 3.6 kg of PM-200 and 0.6 kg of INOVOL S25K, stir for 30 min, take samples for testing, and the measured -NCO concentration is 20.0 wt.%. After passing the test, cool to 45±5°C and seal for storage.

[0072] Component C is nano-silicon dioxide.

[0073] (3) When in use, the temperature of components A, B and C is maintained at 30±5°C. Components A, B and C are quickly mixed in a mass ratio of 1:0.95:1.9, poured into a mold, and aged at 80°C for 8 hours to obtain the high temperature resistant and hydrolysis resistant polyurethane polishing wheel.

[0074] Example 3

[0075] The preparation method of the high temperature resistant and hydrolysis resistant polyurethane polishing wheel comprises the following steps:

[0076] (1) Preparation of component A: 70 kg of polyether polyol X3 and 30 kg of POP-36 / 30 were weighed and put into a reactor at room temperature and stirred at a speed of 100 r / min. Then, 15 kg of 1,6-hexanediol, 25 kg of diethylene glycol, 40 kg of INOVOL F414, 1 kg of ammonia water, 0.2 kg of pentamethyldiethylenetriamine, 0.01 kg of dibutyltin dimercaptoacetate and 8 kg of HFC-245fa were added. The mixture was stirred at room temperature for 1 h, mixed thoroughly and stored in a sealed container.

[0077] (2) Preparation of component B: Add 20 kg of INOVOL F822 into a reactor at room temperature, stir and heat to 95±5°C, dehydrate and degas for 2 h under a vacuum degree below -0.088 MPa, cool to 45±5°C, add 50.5 kg of 4,4'-MDI, 25.5 kg of MDI-50 and 2 kg of carbodiimide-modified MDI, react at 82±2.5°C for 3 h, add 1 kg of PM-200 and 1 kg of INOVOL F8001A, stir for 30 min, take samples for testing, and the measured -NCO concentration is 26.0 wt.%. After passing the test, cool to 45±5°C and seal for storage.

[0078] Component C is nano-silicon dioxide and cubic boron carbide, and the mass ratio of the two is 1:1.

[0079] (3) When in use, the temperature of components A, B and C is maintained at 30±5°C. Components A, B and C are quickly mixed in a mass ratio of 1:0.86:1.5, poured into a mold, and aged at 80°C for 8 hours to obtain the high temperature resistant and hydrolysis resistant polyurethane polishing wheel.

[0080] Example 4

[0081] The preparation method of the high temperature resistant and hydrolysis resistant polyurethane polishing wheel comprises the following steps:

[0082] (1) Preparation of component A: 65 kg of polyether polyol X4 and 35 kg of POP36 / 28 were weighed and put into a reactor at room temperature and stirred at a speed of 100 r / min. Then, 14 kg of HQEE, 10 kg of ethylene glycol, 20 kg of INOVOLR403, 0.7 kg of water, 0.2 kg of pentamethyldipropylenetriamine, 0.3 kg of bismorpholinyl diethyl ether, 0.04 kg of dioctyltin mercaptan, 9 kg of HCFC-141b and 4 kg of dichloromethane were added. The mixture was stirred at room temperature for 1 h, mixed thoroughly and stored in a sealed container.

[0083] (2) Preparation of component B: Add 27.5 kg of INOVOL F3600 into a reactor at room temperature, stir and heat to 95±5°C, dehydrate and degas for 2 h under a vacuum condition of less than -0.088 MPa, cool to 45±5°C, add 44.4 kg of 4,4'-MDI, 22.2 kg of MDI-50 and 2.2 kg of carbodiimide-modified MDI, react at 82±2.5°C for 2 h, add 2.3 kg of PM-200 and 1.4 kg of INOVOL F8001B, stir for 30 min, take samples for testing, and the measured -NCO concentration is 20.0 wt.%. After passing the test, cool to 45±5°C and seal for storage.

[0084] Component C is corundum.

[0085] (3) When in use, the temperature of components A, B and C is maintained at 30±5°C. Components A, B and C are quickly mixed in a mass ratio of 1:1.08:1.77, poured into a mold, and aged at 80°C for 8 hours to obtain the high temperature resistant and hydrolysis resistant polyurethane polishing wheel.

[0086] Example 5

[0087] The preparation method of the high temperature resistant and hydrolysis resistant polyurethane polishing wheel comprises the following steps:

[0088] (1) Preparation of component A: 60 kg of polyether polyol X5 and 40 kg of POP-36 / 30 were weighed and put into a reactor at room temperature, and stirred at a speed of 100 r / min. Then, 18 kg of diethylene glycol, 12 kg of 1,4-butanediol, 25 kg of INOVOL R405, 1 kg of ammonia water, 0.6 kg of triethylenediamine, 0.05 kg of bismuth isooctanoate, and 15 kg of dichloromethane were added. The mixture was stirred at room temperature for 1 h, mixed thoroughly, and sealed for storage.

[0089] (2) Preparation of component B: 17.8 kg of INOVOL F628 and 7.7 kg of INOVOL F822 were placed in a reactor at room temperature, heated to 95±5°C with stirring, and dehydrated and degassed for 2 h under a vacuum condition of less than -0.088 MPa. The mixture was cooled to 45±5°C, 46.8 kg of 4,4'-MDI, 23.4 kg of MDI-50 and 2 kg of carbodiimide-modified MDI were added, and the mixture was reacted at 82±2.5°C for 2 h. 1.3 kg of PM-200 and 1 kg of INOVOL S25K were added, and the mixture was stirred for 30 min. Samples were taken for testing, and the measured -NCO concentration was 24.1 wt.%. After the mixture passed the test, the mixture was cooled to 45±5°C and sealed for storage.

[0090] Component C is nano-silicon dioxide and silicon carbide, and the mass ratio between the two is 2:1.

[0091] (3) When in use, the temperature of components A, B and C is maintained at 30±5°C. Components A, B and C are quickly mixed in a mass ratio of 1:1.04:1.65, poured into a mold, and aged at 80°C for 8 hours to obtain the high temperature resistant and hydrolysis resistant polyurethane polishing wheel.

[0092] Comparative Example 1

[0093] The difference from Example 3 is that the polyether polyol X3 in component A is replaced by polyether polyol X6 of the same mass, and the rest is the same as Example 3.

[0094] Comparative Example 2

[0095] The difference from Example 3 is that the polyether polyol X3 in component A is replaced by polyether polyol X7 of equal mass, and the rest is the same as Example 3.

[0096] Comparative Example 3

[0097] The difference from Example 3 is that the polyether polyol X3 in component A is replaced by polyether polyol X8 of the same mass, and the rest is the same as Example 3.

[0098] Comparative Example 4

[0099] The difference from Example 3 is that the polyether polyol X3 in component A is replaced by 43.8 kg of INOVOL F628 and 26.2 kg of POL-1276, and the rest is the same as Example 3.

[0100] The polyurethane polishing wheels prepared in Examples 1 to 5 and Comparative Examples 1 to 4 were sliced, and the performance of the samples was tested. The testing method is as follows:

[0101] The density was tested according to GB / T 6343-2009, the hardness was tested according to GB / T 10807-2006, the tensile strength and elongation at break were tested according to GB / T 6344-2008, and the heat and humidity aging resistance was tested according to the requirements of GB / T 9640-2008. The tensile strength and elongation at break loss rates were calculated after being treated at a temperature of 120°C and a humidity of 100% for 72 hours. The test results are shown in Table 1:

[0102] Table 1 Performance comparison of polyurethane polishing wheels

[0103]

[0104] As can be seen from Table 1, the high temperature and hydrolysis resistant polyurethane polishing wheels prepared by the polyether polyol and the preparation method of the present invention in Examples 1 to 5 have a mechanical property loss rate of no more than 5% after being treated in a hot and humid environment at a temperature of 120°C and a humidity of 100% for 72 hours, and their high temperature and hydrolysis resistance are greatly improved compared with the polishing wheels in Comparative Examples 1 to 4. The formula systems of Comparative Examples 1 and 4 do not contain Si-O-Si segments, and their resistance to hot and humid aging is very poor. In Comparative Example 4, a mixture of polyether polyol and polyester polyol is used, and the storage stability is poor, and the polyether polyol and polyester polyol mixture are stored for a long time ...

Claims

1. A high temperature resistant and hydrolysis resistant polyurethane polishing wheel, characterized in that: Prepared by the reaction of three components A, B, and C, the mass ratio of the three components A, B, and C is 1: (0.85~1.33): (1.5~1.9); Wherein, the component A comprises the following raw materials in parts by weight: polyether polyol X: 50-70 parts, polymer polyol: 30-50 parts, chain extender: 20-40 parts, cross-linking agent: 3-40 parts, catalyst: 0.21-0.85 parts, foaming agent: 8.5-16 parts; The component B is composed of the following raw materials in parts by weight: polyether polyol Y: 20-36.5 parts, 4,4'-MDI: 38.5-50.5 parts, MDI-50: 19-25.5 parts, carbodiimide modified MDI: 1.8-2.2 parts, polymethylene polyphenyl polyisocyanate: 1.0-3.6 parts, and pore opener: 0.6-1.4 parts; The C component is an inorganic filler; The functionality of the polyether polyol X is 3-6, the number average molecular weight is 5000-15000 g / mol, and the polyether segment contains ester bonds, ether bonds, and Si-O-Si bonds; The functionality of the polyether polyol Y is 3 to 6, and the number average molecular weight is 5000 to 12000 g / mol; The polyether polyol X is prepared from an initiator and a polymerization monomer under the action of a catalyst, wherein the initiator is a compound of sorbitol, pentaerythritol, xylitol, mannitol, sucrose and castor oil, and the catalyst is a phosphazene catalyst; the polymerization monomers are propylene oxide, ethylene oxide and cyclosiloxane, and the mass ratio of the three is (6.6-17.8):(1-3):1; The cyclosiloxane is one of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane and a mixed ring of dimethylsiloxane.

2. The high temperature and hydrolysis resistant polyurethane polishing wheel according to claim 1, characterized in that: The chain extender is an alcohol chain extender, the cross-linking agent is an amine cross-linking agent, and the catalyst is a mixture of an amine catalyst and an organic metal catalyst in a mass ratio of (12-27):

1.

3. The high temperature and hydrolysis resistant polyurethane polishing wheel according to claim 2, characterized in that: The amine crosslinking agent is a mixture of one or more of diethanolamine, triethanolamine and a low molecular weight polyether polyol using an amine substance as an initiator, and the number average molecular weight of the low molecular weight polyether polyol using an amine substance as an initiator is 300-1500 g / mol.

4. The high temperature and hydrolysis resistant polyurethane polishing wheel according to claim 2, characterized in that: The alcohol chain extender is a mixture of one or more of 1,4-butanediol, ethylene glycol, diethylene glycol, 1,6-hexanediol, and hydroquinone dihydroxyethyl ether; the amine catalyst is a mixture of one or more of triethylenediamine, bis(dimethylaminoethyl) ether, pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, tetramethylpropylenediamine, and bismorpholinyl diethyl ether; and the organic metal catalyst is one of dibutyltin dilaurate, stannous octoate, dibutyltin dimercaptoacetate, dioctyltin mercaptan, and bismuth isooctanoate.

5. The high temperature and hydrolysis resistant polyurethane polishing wheel according to claim 1, characterized in that: The foaming agent is a mixture of a physical foaming agent and a chemical foaming agent, the mass ratio of the physical foaming agent to the chemical foaming agent is (8-37.5):1, the physical foaming agent is a mixture of one or more of HCFC-141b, dichloromethane, and HFC-245fa, and the chemical foaming agent is one of ammonia water and water.

6. The high temperature and hydrolysis resistant polyurethane polishing wheel according to claim 1, characterized in that: The inorganic filler is a mixture of one or more of nano silicon dioxide, silicon carbide, corundum and cubic boron carbide.

7. A method for preparing a high temperature resistant and hydrolysis resistant polyurethane polishing wheel according to any one of claims 1 to 6, characterized in that: Here are the steps: (1) Preparation of component A: Add polyether polyol X and polymer polyol into a reaction kettle and stir at room temperature, then add chain extender, cross-linking agent, catalyst and foaming agent, stir at room temperature and store in a sealed container; (2) Preparation of component B: put polyether polyol Y into a reactor at room temperature, stir and heat it to 90-100°C, dehydrate and degas under vacuum conditions, cool it down, add 4,4'-MDI, MDI-50, and carbodiimide-modified MDI, heat it to 80-85°C and react for 2-3h, add polymethylene polyphenyl isocyanate and pore opening agent and stir, test the -NCO content to be between 20-26wt.%, cool it down, and seal it for storage; (3) When in use, component A, component B and component C are mixed evenly, and then poured into a mold. After ripening, the high temperature resistant and hydrolysis resistant polyurethane polishing wheel is obtained.

8. The method for preparing the high temperature resistant and hydrolysis resistant polyurethane polishing wheel according to claim 7, characterized in that: The cooling in step (2) is to cool the temperature to 40-50°C.

Images