低成本环保脲醛树脂合成工艺的研究
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摘要
脲醛树脂(UF)胶粘剂具有原料丰富、成本低廉、粘结性能好等优点,是木材工业中使用量最大的胶粘剂。然而,脲醛树脂及其制品在生产和使用过程中会释放出甲醛,严重影响了人们的身心健康。因此,如何生产出游离甲醛含量低、胶合强度高的脲醛树脂,成为我国胶粘剂行业中的一个研究重点。
本论文首先,研究了“弱碱-弱酸-弱碱”合成工艺过程中各阶段的摩尔比、pH值、反应温度以及反应时间等因素对胶粘剂各项性能的影响。由此所确定的较优工艺条件为:三阶段的醛脲比分别为r1=2.4、r2=1.8、r3=1.2;pH值分别为pH1=8.0、pH2=5.0、pH3=8.5;反应温度分别为T1=60℃、T2=91℃、T3=70℃;反应时间分别为t1=60min、t3=40min。用该工艺所合成的脲醛树脂符合低游离甲醛含量的国家标准要求,其各项指标为:粘度0.36Pa.s、固化时间58.0s、固体含量52.42%、游离甲醛含量0.18%。
加入氧化淀粉,使脲醛树脂中的游离醛含量进一步降低,使树脂的胶合强度上升,储存期延长,固含量增加。同时,降低了生产成本。
Urea-formaldehyde (UF) resins has many advantages such as abundant raw materials, low cost, good agglutinative performance and so on,are most widely used adhesives. However UF resins and their products will release formaldehyde which seriously affect healthy in mind and body of people in the process of production and their application. The adhesive industry has focused on the research to produce UF resins with low free formaldehyde content (FFC) and with high agglutinative strength.
The effect of several factors on UF resin properties were firstly studied on the basis of“mild base-mild acid-mild base”synthetic technique, which included adding urea in three portions respectively. The factors are the molar ratio of formaldehyde to urea, the pH value, the temperature and time of reaction in every stage, and there is no modifying agent used during the synthetic technique.
According to the above experiments, the synthetic conditions are determined as follows. The molar ratios of formaldehyde to urea are r1=2.4, r2=1.8 and r3=1.2; the pH values are: pH1=8.0, pH2=5.0 and pH3=8.5, the temperature are T1=60℃, T2=91℃and T3=70℃; the reaction time are t1=60min, and t3=40min. The UF resins produced by the process meet the requests of national standard for low free formaldehyde. The viscosity is 65.2mPa.S, the curing time is 42.0s, the solid content is 49.93%, the free formaldehyde content is 0.44%, for the UF resin. Especially the agglutinative strength of cold pressing board is as high as 1.52 MPa, exceeding that of the national standard for hot pressing board (>0.8MPa). The cold pressing method is superior to the hot pressing method, not only for easy operation but also for more energy savings.
when oxidative starch join in urea formaldehyde resin, the free formaldehyde content is decreased, the solid content is improved, agglutinative strength is increased, store time is elongated. At one time, produce cost is increased.
本论文首先,研究了“弱碱-弱酸-弱碱”合成工艺过程中各阶段的摩尔比、pH值、反应温度以及反应时间等因素对胶粘剂各项性能的影响。由此所确定的较优工艺条件为:三阶段的醛脲比分别为r1=2.4、r2=1.8、r3=1.2;pH值分别为pH1=8.0、pH2=5.0、pH3=8.5;反应温度分别为T1=60℃、T2=91℃、T3=70℃;反应时间分别为t1=60min、t3=40min。用该工艺所合成的脲醛树脂符合低游离甲醛含量的国家标准要求,其各项指标为:粘度0.36Pa.s、固化时间58.0s、固体含量52.42%、游离甲醛含量0.18%。
加入氧化淀粉,使脲醛树脂中的游离醛含量进一步降低,使树脂的胶合强度上升,储存期延长,固含量增加。同时,降低了生产成本。
Urea-formaldehyde (UF) resins has many advantages such as abundant raw materials, low cost, good agglutinative performance and so on,are most widely used adhesives. However UF resins and their products will release formaldehyde which seriously affect healthy in mind and body of people in the process of production and their application. The adhesive industry has focused on the research to produce UF resins with low free formaldehyde content (FFC) and with high agglutinative strength.
The effect of several factors on UF resin properties were firstly studied on the basis of“mild base-mild acid-mild base”synthetic technique, which included adding urea in three portions respectively. The factors are the molar ratio of formaldehyde to urea, the pH value, the temperature and time of reaction in every stage, and there is no modifying agent used during the synthetic technique.
According to the above experiments, the synthetic conditions are determined as follows. The molar ratios of formaldehyde to urea are r1=2.4, r2=1.8 and r3=1.2; the pH values are: pH1=8.0, pH2=5.0 and pH3=8.5, the temperature are T1=60℃, T2=91℃and T3=70℃; the reaction time are t1=60min, and t3=40min. The UF resins produced by the process meet the requests of national standard for low free formaldehyde. The viscosity is 65.2mPa.S, the curing time is 42.0s, the solid content is 49.93%, the free formaldehyde content is 0.44%, for the UF resin. Especially the agglutinative strength of cold pressing board is as high as 1.52 MPa, exceeding that of the national standard for hot pressing board (>0.8MPa). The cold pressing method is superior to the hot pressing method, not only for easy operation but also for more energy savings.
when oxidative starch join in urea formaldehyde resin, the free formaldehyde content is decreased, the solid content is improved, agglutinative strength is increased, store time is elongated. At one time, produce cost is increased.
引文
[1] 李东光.脲醛树脂胶粘剂.北京:化学工业出版社,2002:1-2
[2] Wawzonek,Stanley.Formaldehyde depressed particle board. United States Patent,US:4457978,May 16,1983
[3] 朱桂芝,李涛,郭晓诗等.甲醛对人体毒作用.中国卫生工程学,2004;(04):60-61
[4] 严顺英,顾丽莉.脲醛树脂的研究现状与研究前景.化工科技,2005;(04):53-57
[5] 李东光.脲醛树脂胶粘剂.北京:化学工业出版社,2002:3-4
[6] 吴蓁,孙揭阳,郭青.脲醛树脂的研究现状.化学进展,2006;25(2):187-191
[7] De Jong J I ,De Jonge J .The formation and decomposition of dimethylolure.Recueil des Travaux Chimiques des Pays-Bas.1952;71:661-667
[8] De Jong J I,De Jonge J.The reaction between urea and formaldehyde in concentrated solutions . Recueil des Travaux Chimiques des Pays-Bas.1952;71:891-898
[9] De Jong J I , De Jonge J . The reaction of urea with formaldehyde.Recueil des Travaux Chimiques des Pays-Bas.1952;71:643-660
[10] 崔波,曹长青,张青瑞等.尿素和甲醛合成脲醛树脂粘合剂的动力学研究.中国胶粘剂,1997;06(04):4-7
[11] Chung-Yun Hse,Zhi-Yuan Xia,Bunichiro omita.Effects of reaction pH on properties and performance of urea-foramldehyde resins.holzfordc1994;48(06):527-532
[12] 李东光.脲醛树脂胶粘剂.北京:化学工业出版社,2002:6-7
[13] 丁著明,范华.低毒脲醛树脂胶粘剂的研究进展.化工技术与开发,2004;33(04):22-35
[14] 顾丽莉,罗云,刘静等.低毒脲醛树脂的合成机理.中国胶粘剂,1998;07(05):19-23
[15] 刘凤杰,宋彦梅,衣守志.脲醛树脂粘合剂中低甲醛释放的研究进展.天津化工,2004;18(05):28-30
[16] 李东光.脲醛树脂胶粘剂.北京:化学工业出版社,2002:191-192
[17] 顾丽莉,刘静,宋红.合成低毒脲醛树脂的工艺及应用研究.四川化工与腐蚀控制,1998;(04):5-9
[18] 顾继友.室内用人造板与低甲醛释放脲醛树脂胶粘剂的开发与应用.林产工业,2003;(01):12-15
[19] 韩书广,吴羽飞.改性脲醛树脂合成工艺与性能的关系.南京林业大学学报(自然科学版),2005;29(03):77-80
[20] 刘澎,何娟,邝爱燕等.脲醛树脂低醛胶制备工艺进展.河南化工,1997;(06):35-37
[21] 王敏娟,王建华.低游离醛脲醛树脂的合成.热固性树脂,2001;16(04):19-20
[22] 赵瑛,张海燕,齐国庆.低醛脲醛树脂的制备.石化技术与应用,2000;05(05):272-274
[23] 徐红,张东翔.脲醛树脂改性工艺中的酸度条件控制.中国胶粘剂,2002;1(4):21-23
[24] 于红卫,傅深渊.低毒脲醛树脂的合成.浙江林学报,2002;19(2):122-126
[25] 杨明平,彭荣华,李国斌.环保型脲醛树脂胶合成工艺的探讨.中国胶粘剂,2004,13(1):7—10
[26] 薛东.低游离甲醛脲醛树脂的研制.化学与粘合,2003;(6):317-318
[27] 卢晓宁,韩书广,吴羽飞等.用不脱水低摩尔脲醛树脂制造低游离甲醛刨花板与中密度纤维板.林业科学,2002;38(02):110-114
[28] 吕守茂,丁亚玲.改性脲醛树脂新进展.化学与粘合,2000;(03):130-135
[29] 古绪鹏,邵百花.低毒稳定型脲醛树脂胶粘剂的制备.粘接,2000;21(01):32-34
[30] 王喜明,高志悦,安珍等.沙柳刨花板及低毒脲醛树脂胶研究.林产工业,1997;24(05):27-30
[31] 傅深渊.环保型脲醛树脂胶及其在胶合板中的应用研究:[硕士学位论文].杭州:浙江工业大学,2004
[32] 樋口光夫．关于脲醛树脂胶的改性研究．木材学会志，1979;25(07):496-502
[33] 黄光佛,黄世强,陈运中.改性 PVF 胶粘剂及其性能的研究.中国胶粘剂,1994;(06):22-27
[34] 李东光.脲醛树脂胶粘剂.北京:化学工业出版社,2002:291-304
[35] 李东光.脲醛树脂胶粘剂.北京:化学工业出版社,2002:119-120
[36] 朱利平,顾丽莉,张彦民.低毒耐水脲醛树脂的合成.林产工业,2003;30(04):25-28
[37] 顾丽莉,罗云,刘静等.不脱水低毒脲醛树脂的研制.林产化学与工业,1998;18(04):15-19
[38] 杜官本.缩聚条件对脲醛树脂结构的影响.粘接,2000;21(04):12-16
[39] 杜官本.摩尔比对脲醛树脂初期产物结构影响的研究.粘接,1999;20(03):1-5
[40] 傅深渊.环保型脲醛树脂胶及其在胶合板中的应用研究:[硕士学位论文].杭州:浙江工业大学,2004
[41] 郭立凯.化学建材.北京:化学工业出版社,1995:161-162
[2] Wawzonek,Stanley.Formaldehyde depressed particle board. United States Patent,US:4457978,May 16,1983
[3] 朱桂芝,李涛,郭晓诗等.甲醛对人体毒作用.中国卫生工程学,2004;(04):60-61
[4] 严顺英,顾丽莉.脲醛树脂的研究现状与研究前景.化工科技,2005;(04):53-57
[5] 李东光.脲醛树脂胶粘剂.北京:化学工业出版社,2002:3-4
[6] 吴蓁,孙揭阳,郭青.脲醛树脂的研究现状.化学进展,2006;25(2):187-191
[7] De Jong J I ,De Jonge J .The formation and decomposition of dimethylolure.Recueil des Travaux Chimiques des Pays-Bas.1952;71:661-667
[8] De Jong J I,De Jonge J.The reaction between urea and formaldehyde in concentrated solutions . Recueil des Travaux Chimiques des Pays-Bas.1952;71:891-898
[9] De Jong J I , De Jonge J . The reaction of urea with formaldehyde.Recueil des Travaux Chimiques des Pays-Bas.1952;71:643-660
[10] 崔波,曹长青,张青瑞等.尿素和甲醛合成脲醛树脂粘合剂的动力学研究.中国胶粘剂,1997;06(04):4-7
[11] Chung-Yun Hse,Zhi-Yuan Xia,Bunichiro omita.Effects of reaction pH on properties and performance of urea-foramldehyde resins.holzfordc1994;48(06):527-532
[12] 李东光.脲醛树脂胶粘剂.北京:化学工业出版社,2002:6-7
[13] 丁著明,范华.低毒脲醛树脂胶粘剂的研究进展.化工技术与开发,2004;33(04):22-35
[14] 顾丽莉,罗云,刘静等.低毒脲醛树脂的合成机理.中国胶粘剂,1998;07(05):19-23
[15] 刘凤杰,宋彦梅,衣守志.脲醛树脂粘合剂中低甲醛释放的研究进展.天津化工,2004;18(05):28-30
[16] 李东光.脲醛树脂胶粘剂.北京:化学工业出版社,2002:191-192
[17] 顾丽莉,刘静,宋红.合成低毒脲醛树脂的工艺及应用研究.四川化工与腐蚀控制,1998;(04):5-9
[18] 顾继友.室内用人造板与低甲醛释放脲醛树脂胶粘剂的开发与应用.林产工业,2003;(01):12-15
[19] 韩书广,吴羽飞.改性脲醛树脂合成工艺与性能的关系.南京林业大学学报(自然科学版),2005;29(03):77-80
[20] 刘澎,何娟,邝爱燕等.脲醛树脂低醛胶制备工艺进展.河南化工,1997;(06):35-37
[21] 王敏娟,王建华.低游离醛脲醛树脂的合成.热固性树脂,2001;16(04):19-20
[22] 赵瑛,张海燕,齐国庆.低醛脲醛树脂的制备.石化技术与应用,2000;05(05):272-274
[23] 徐红,张东翔.脲醛树脂改性工艺中的酸度条件控制.中国胶粘剂,2002;1(4):21-23
[24] 于红卫,傅深渊.低毒脲醛树脂的合成.浙江林学报,2002;19(2):122-126
[25] 杨明平,彭荣华,李国斌.环保型脲醛树脂胶合成工艺的探讨.中国胶粘剂,2004,13(1):7—10
[26] 薛东.低游离甲醛脲醛树脂的研制.化学与粘合,2003;(6):317-318
[27] 卢晓宁,韩书广,吴羽飞等.用不脱水低摩尔脲醛树脂制造低游离甲醛刨花板与中密度纤维板.林业科学,2002;38(02):110-114
[28] 吕守茂,丁亚玲.改性脲醛树脂新进展.化学与粘合,2000;(03):130-135
[29] 古绪鹏,邵百花.低毒稳定型脲醛树脂胶粘剂的制备.粘接,2000;21(01):32-34
[30] 王喜明,高志悦,安珍等.沙柳刨花板及低毒脲醛树脂胶研究.林产工业,1997;24(05):27-30
[31] 傅深渊.环保型脲醛树脂胶及其在胶合板中的应用研究:[硕士学位论文].杭州:浙江工业大学,2004
[32] 樋口光夫．关于脲醛树脂胶的改性研究．木材学会志，1979;25(07):496-502
[33] 黄光佛,黄世强,陈运中.改性 PVF 胶粘剂及其性能的研究.中国胶粘剂,1994;(06):22-27
[34] 李东光.脲醛树脂胶粘剂.北京:化学工业出版社,2002:291-304
[35] 李东光.脲醛树脂胶粘剂.北京:化学工业出版社,2002:119-120
[36] 朱利平,顾丽莉,张彦民.低毒耐水脲醛树脂的合成.林产工业,2003;30(04):25-28
[37] 顾丽莉,罗云,刘静等.不脱水低毒脲醛树脂的研制.林产化学与工业,1998;18(04):15-19
[38] 杜官本.缩聚条件对脲醛树脂结构的影响.粘接,2000;21(04):12-16
[39] 杜官本.摩尔比对脲醛树脂初期产物结构影响的研究.粘接,1999;20(03):1-5
[40] 傅深渊.环保型脲醛树脂胶及其在胶合板中的应用研究:[硕士学位论文].杭州:浙江工业大学,2004
[41] 郭立凯.化学建材.北京:化学工业出版社,1995:161-162
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