AU2012327770B2

AU2012327770B2 - Preparation method of rigid polyurethane

Info

Publication number: AU2012327770B2
Application number: AU2012327770A
Authority: AU
Inventors: Hailiang Chen; Wei Chen; Youliang CHEN; Fang Zhang
Original assignee: Shandong Dongda Inov Polyurethane Co Ltd
Current assignee: Shandong Dongda Inov Polyurethane Co Ltd
Priority date: 2011-10-27
Filing date: 2012-03-19
Publication date: 2015-08-13
Anticipated expiration: 2032-03-19
Also published as: CN102504182A; BR112013026720A2; WO2013060088A1; BR112013026720B1; AU2012327770A1; MY163189A; CN102504182B

Abstract

Disclosed is a preparation method of rigid polyurethane. A chain extender is heated at 100-110°C to melt, and is mixed and reacts with a prepolymer with the mass ratio being 20-29.4:100. The mixing temperature is 60-75°C. The produce is poured into a mold, and undergoes vulcanization at 100-110°C for 30 minutes before de-molding. Finally, the produce undergoes vulcanization at 90-110°C for 8-10 hours to obtain rigid polyurethane. In weight percent, diisocyanate (24.5-50%) and polymer polyol (50-75.5%) react at 80-85°C for 2-3 hours, so as to obtain the prepolymer with isocyanate accounts for 7-10%. The chain extender is an amine-based chain extender. Therefore, the problem of decreased product hardness incurred by intermolecular hydrogen bond breakage and decreased intermolecular forces when the rigid polyurethane is at high temperature is solved, and rigid polyurethane with the Shore hardness greater than D60 at room temperature and the Shore hardness still greater than D50 at 80°C is obtained.

Description

H:'bsxntevoviiIR~nbLC.CBS ?j46,2, doe - 1!!15 SPECIFICATION Title: Preparation Method of Rigid Polyurethane TECHNICAL FIELD The present invention relates to a polyurethane preparation method, It involves a 5 preparation method of rigid polyurethane. BACKGROUND ART The polyurethane has a unique structure of the block copolymer with soft and hard segments, which gives its products excellent mechanical properties, while the hardness of the article can be adjusted by a wide range. These excellent 10 comprehensive properties outforn many other kinds of commercialized rubber and plastics. The polyurethane can be used to produce a polyurethane elastomer with excellent resiliency and a rigid material with the hardness greater than Shore D 60: These rigid polyurethane materials are commonly used to bear the heavy load and high temperature at work place, which requires polyurethane products to have a high 15 hardness, usually greater than Shore D60 and even greater than Shore D 50 at a temperature of 800C. The hardness variation of the conventional polyurethane is very large between high and low temperature. At room temperature, it is easy to achieve the hardness greater than Shore D60. But at 8000, as a result of the intermolecular breakage of hydrogen bonding and the decrease of the intermolecular forces, the 20 hardness decreases quickly, usually less than Shaw D40. As low hardness can not bear high load, the product can not meet the requirements. SUMMARY OF THE INVENTION The present invention aims to provide a method for the preparation of a rigid polyurethane, dealing with the problem of the rigid polyurethane intermolecular 25 hydrogen bond breakage and intermolecular force reduction at high temperature, which results in the product hardness reduction. Using this method it may be possible to obtain rigid polyurethane with the hardness greater than Shore D60 at normal temperature and still greater than Shore D50 at 800 The present invention provides a method for preparing rigid polyurethane by 30 reacting a prepolymer and a chain extender, the method comprising: preparing the prepolymer according to the following steps: preparing a mixture of 24.5~50 wt% diisocyanate and 50~75.5 wt% polymer polyol, wherein the diisocyanate is toluene diisocyanate and the polymer polyol (i) comprises one or more of a polypropylene oxide ether polyol, a 35 polytetrahydrofuran ether polyol or a polycaprolactone polyol, and (ii) has a functionality of 2~3 and a number average molecular weight in the range of 300~' 3000, and wherein the polymer polyol with a functionality of 3 accounts for 26 50% of the total mass of the polymer polyol, -2 reacting the mixture for 2-3 hours at 80-85C to obtain the prepolymer, the prepolymer having an isocyanate mass content of 7-10%, melting the chain extender at 100- 110 C, wherein the chain extender is an amine chain extender, 5 mixing the melted chain extender and the prepolymer according to a chain extender to prepolymer mass ratio of 20-29.4: 100. reacting the mixture of the chain extender and the prepolymer at 60--75'C, pouring the reacted mixture of the chain extender and the prepolymer into a mold and vulcanizing it at 100~110'C for 30 minutes, 10 stripping the mold, and vulcanize the mixture of the chain extender and the prepolymer at 90-110'C for 8--10 hours to obtain the rigid polyurethane. Also described as the diisocyanate is diphenyl methane diisocyanate. The amine chain extender is preferably MOCA, E-300 or M-CDEA. 15 The toluene diisocyanate is preferably TDI-80 or TD-1l00 and the diphenylnethane diisocyanate is preferably MDi-50 or MDI- 100. The rigid polyurethane obtained by the method of the present invention is at a hardness of Shore D60-80. For the rigid polyurethane products used at 80'C, its hardness can be maintained at greater than Shore D50. 20 The beneficial effects of the present invention is: by adding a polymer polyol accounting for 26%-50% of the total mass of polymer polyol and with a functionality of 3, the rigid polyurethane molecules produce certain urethane chemical cross-links, offsetting the impact of the intermolecular hydrogen bond breakage and intermolecular force reduction to ensure that the products of the rigid polyurethane 25 can be used at high temperatures. BEST MODE FOR CARRYING OUT THE INVENTION The following examples further illustrate the present invention. Materials used are as follows: PPG220: polypropylene oxide ether diol, with the number average molecular 30 weight at 2000 PPG330: polypropylene oxide ether triol, with the number average molecular weight at 3000 PPG210: polypropylene oxide ether diol, with the number average molecular weight at 1000 35 PPG400: polypropylene oxide ether diol, with the number average molecular weight at 400 - 2A PPG303; polypropylene oxide ether triol, with the number average molecular weight at 300 PTMG2000; polytetrahydroftran ether diol, with the number average molecular 5 weight at 2000 PTMG1000: polytetrahydrofuran ether diol, with the number average molecular weight at 1000 H:\kxg\Interwoven\NRPortbl\DCC\KXG\5770746_1.DOC - 28/10/13 -3 PCL210: polycaprolactone diol, with the number average molecular weight at 1000 PCL220: polycaprolactone diol, with the number average molecular weight at 2000 5 MDI-50: 4,4'- diphenylmethane diisocyanate of 50%, 2,4' - diphenylmethane diisocyanate of 50% MDI-100: 4,4'- diphenyl methane diisocyanate TDI-100: 2,4 - toluene diisocyanate TDI-80: 2,4 - toluene diisocyanate of 80%, 2,6 - toluene diisocyanate of 20% 10 M-CDEA: 4,4'- methylene - bis - (3-chloro-2, 6-diethylene aniline) MOCA: 3,3'- dichloro-4, 4'- diaminodiphenyl methane E-300: dimethylthiotoluenediamine. Example 1: Preparation of prepolymer: by weight percentage, the polytetrahydrofuran polyol 15 prepolymer with a molecular weight of 1,000 (PTMG1000) of 37.75%, the polypropylene oxide ether polyols with a molecular weight of 3,000 (PPG330) of 37.75%, and TDI-100 of 24.5%. Maintain reaction for 3 hours at 80 *C and then remove bubbles in vacuum (-0.095MPa). Obtain the prepolymer with the mass content of the isocyanate at 7.0% . 20 Preparation of the rigid polyurethane: Mix the obtained prepolymer and the melted M-CDEA at a mass ratio of 100:29.4 and maintain reaction at 65 "C. Pour the mixture into a mold and vulcanize at 100 0 C for 30 minutes. Strip the mold. Vulcanize the mixture at 110 'C for 8 hours. Obtain the rigid polyurethane with a hardness of Shore D60 at 25 *C. 25 Example 2: Preparation of prepolymer: by weight percentage, the polytetrahydrofuran polyol prepolymer with a molecular weight of 2000 (PTMG2000) of 53%, the polypropylene oxide ether polyol with a molecular weight of 300 (PPG330) of 13%, and TDI-80 of 34%. Maintain reaction for 2 hours at 85 "C and then remove bubbles in vacuum 30 (-0.095MPa). Obtain the prepolymer with the mass content of the isocyanate at 8.5%. Preparation of the rigid polyurethane: Mix the obtained prepolymer and the melted E-300 at a mass ratio of 100:20 and maintain reaction at 60 'C. Pour the mixture into a mold and vulcanize at 100 'C for 30 minutes. Strip the mold. Vulcanize the mixture at 110 'C for 8 hours. Obtain the rigid polyurethane with a 35 hardness of Shore D70 at 25 *C. Example 3: H:\kxg\lnterwoven\NRPortbl\DCC\KXG\5770746_1.DOC - 28/10/13 -4 Preparation of prepolymer: by weight percentage, the polycaprolactone polyol with a molecular weight of 1000 (PCL210) of 25%, the polycaprolactone polyol with a molecular weight of 2000 (PCL220) of 15%, the polypropyleneoxide ether with a molecular weight of 300 (PPG303) of 10%, MDI-50 of 40.3%, MDI-100 of 5 9.7%.Maintain reaction for 3 hours at 80 'C and then remove bubbles in vacuum (-0.095MPa). Obtain the prepolymer with the mass content of the isocyanate at 10% . Preparation of the rigid polyurethane: Mix the obtained prepolymer and the melted MOCA at a mass ratio of 100:28.5 and maintain reaction at 75 'C. Pour the mixture into a mold and vulcanize at 110 'C for 30 minutes. Strip the mold. 10 Vulcanize the mixture at 110 *C for 8 hours. Obtain the rigid polyurethane with a hardness of Shore D80 at 25"C. Example 4: Preparation of prepolymer: by weight percentage, the polycaprolactone polyol with a molecular weight of 1000 (PCL210) of 25.5%, the polycaprolactone polyol 15 with a molecular weight of 2000 (PCL220) of 25.5%, the polypropyleneoxide ether with a molecular weight of 300 (PPG303) of 12.7%, TDI-100 of 30.3%, TDI-80 of 6%.Maintain reaction for 3 hours at 85 'C and then remove bubbles in vacuum (-0.095MPa). Obtain the prepolymer with the mass content of the isocyanate at 8.8%. Preparation of the rigid polyurethane: Mix the obtained prepolymer and the 20 melted MOCA at a mass ratio of 100:25.5 and maintain reaction at 75 *C. Pour the mixture into a mold and vulcanize at 110 "C for 30 minutes. Strip the mold. Vulcanize the mixture at 110 "C for 8 hours. Obtain the rigid polyurethane with a hardness of Shore D75 at 25"C. Comparative Example 1: 25 Preparation of prepolymer: by weight percentage,the polycaprolactone polyol with a molecular weight of 1000 (PCL210) of 45.0%, thepolypropylene oxide polyol with a molecular weight of 400 (PPG400) of 19.7%, and TDI-100 of 35.3%. Maintain reaction for 3 hours at 85 C and then remove bubbles in vacuum (-0.095MPa). Obtain the prepolymer with the mass content of the isocyanate at 8.8%. 30 Preparation of the rigid polyurethane: Mix the obtained prepolymer and the melted MOCA at a mass ratio of 100:25.5 and maintain reaction at 75 *C. Pour the mixture into a mold and vulcanize at 110 "C for 30 minutes. Strip the mold. Vulcanize the mixture at 110 "C for 8 hours. Obtain the rigid polyurethane with a hardness of Shore D75 at 25 "C. 35 The properties of the rigid polyurethane obtained from the above Examples and Comparative Example are shown in the following table. Item Example Example Example Example Comparative 1: 2: 3: 4: Example 1: n:/jst~terovelNRortb DC JB$$777462Ace - S9.06!IS . ~ ~ ~ . 5 ..... Hardness at D75 D60 D70 D80 D75 25 (Shore) Hardness at D38 D54 D56 D67 D65 80 (Shore) 'reni-se 57.4 593 61.1 51.6 strength (Mpa) Elongation % 230 285 220 260 360 Tear strength 117.1 124.4 147.3 130.2 1403 (KN/m) Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or 5 group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Claims

1. A method for preparing rigid polyurethane by reacting a prepolymer and a chain extender, the method comprising: a) preparing the prepolymer according to the following steps: in weight percent, preparing a mixture of 24.5 to 50% diisocvanate and 50 to

75.5% polymer polyol, wherein the diisocyanate is toluene diisocyanate and the polymer polyol (i) comprises one or more of a polypropylene oxide ether polyol, a polytetrahydrofuran ether polyol and a polycaprolactone polyol, and (ii) has a functionality of 2 to 3 and a number average molecular weight in the range of 300 to 3000, and wherein the polymer polyol with a functionality of 3 accounts for 26 to 50% of the total mass of the polymer polyol; and reacting the mixture for 2 to 3 hours at a temperature of 80 to 85'C to obtain the prepolymer, the prepolymer having an isocyanate mass content of'/ to 10%; b) melting the chain extender at a temperature of 100 to 11 0C, wherein the chain extender is an amine chain extender; c) mixing the melted chain extender and the prepolymer according to a chain extender to prepolymer mass ratio of 20 to 29.4: 100; d) reacting the mixture obtained in step c) at a temperature of 60 to 75 0 C; e) pouring the reacted mixture obtained in step d) into a mold and vulcanizing it at a temperature of 100 to 110*C for 30 minutes; f) stripping the vulcanized mixture obtained in step e) fiom the mold; and g) further vulcanize the stripped mixture at a temperature of 90 to 110*C for 8 tol0 hours to obtain the rigid polyurethane. 2. The method according to claim 1, wherein the polymer polyol with a functionality of 3 accounts for 26 to 40% of the total mass of the polymer polyol. 3. The method according to claim I or 2, wherein the toluene diisocyanate is TDI-80 or TDI-100. 4. The method according to any one of claims 1 to 3, wherein the amine chain extender is MOCA, E-300, or M-CDEA.