摘要:
Low temperature flexible polyurethane elastomers are prepared by reacting organic polyisocyanates with polyester polyols which have glass transition temperatures of -10.degree. to -80.degree. C. and incorporating therein alkoxylated esters of fatty acids and/or alkoxylated terpene alcohols.
摘要:
The invention relates to a process for preparing high temperature-resistant dense or cellular polyurethane elastomers by reacting the following, preferably using low-pressure processing techniques:(a) organic polyisocyanates, preferably in the form of isocyanate group-containing prepolymers and/or modified urethane group-containing organic polyisocyanates, with(b) relatively high molecular weight compounds having at least 2 reactive hydrogen atoms,(c) urea derivatives and, optionally,(d) chain extenders and/or cross-linking agents in the presence of(e) catalysts and, optionally,(f) blowing agents(g) auxiliaries and/or additiveswherein amino and/or hydroxyl group-substituted ureas and/or polyureas having molecular weights from 200 to 4000 are also used as the urea derivatives. Said ureas and/or polyureas are prepared by reacting organic diisocyanates with primary aliphatic and/or cycloaliphatic diamines and/or alkanolamines in molar ratios of from 1:1.1 to 1:2, preferably in the presence of polyester or polyether polyols as solvents or diluting agents.
摘要:
A process for the preparation of optionally cellular and non-cellular polyurethane elastomers, preferably by reaction injection molding, organic polyisocyanates, polyether polyols based on polyoxyalkylene polyether polyols with terminal hydroxyethylene groups and an ethoxylation degree of 1 to 13, having a content of primary hydroxyl groups at the corresponding degree of ethoxylation as the value of curve A to 100 percent with curve A describing the dependency of the primary hydroxyl group content upon the degree of ethoxylation are reacted with chain extenders and/or cross-linking agents in the presence of catalysts as well as optionally blowing agents, auxiliaries and additives.
摘要:
This invention relates to a process for preparing cellular polymers having urethane groups, isocyanurate groups, or both. The cellular polymers are prepared by reacting an organic polyisocyanate with certain polymer dispersions in the presence of a blowing agent.The polymer dispersions comprise(a) as a continuous phase, a polyol having a functionality of 2 to 8 and a hydroxyl number of 150 to 700; and(b) as a dispersed phase, an organic compound having(a) at least one Zerewitinoff active hydrogen atom,(b) a melting point of 30.degree. C. to 260.degree. C., and(c) a molecular weight of 178 to 100,000.
摘要:
A process for purifying crude polyether polyols which are prepared by anionic polymerization of alkylene oxides in the presence of basic catalysts. The polyols are mixed with water and ortho-phosphoric acid in certain quantity ratios, an adsorption agent is incorporated in the reaction mixture, the mixture is filtered and the water is removed from the polyether polyol by distillation.
摘要:
In order to prepare polyester or polyetherpolyester polyols, polyols, preferably di- to hexafunctional polyether polyols having hydroxyl numbers from 15 to 250 are esterified with at least one carboxylic acid anhydride, preferably phthalic acid anhydride, in the presence of N-methylimidazole, triethylenediamine, and/or triphenylphosphine as catalysts to form a carboxylic acid half-ester, and said half-ester is then oxyalkylated with at least one alkylene oxide, preferably ethylene oxide, in the presence of N-methylimidazole, triethylenediamine, triphenylphosphine, thiodialkylene glycol, employing a mixture of at least two of the compounds cited as catalysts.
摘要:
The invention relates to a process for the preparation of cellular or non-cellular polyurethanes through the reaction of organic polyisocyanates with a polyether-polyester polyol component containing di- to tetrafunctional polyether-polyester polyols having hydroxyl numbers of from 10 to 200, which are themselves prepared by esterifying conventional di- to tetrafunctional polyether polyols with carboxylic acid anhydrides, preferably aromatic carboxylic acid anhydrides, in the presence of selected catalysts to form carboxylic acid half esters, and oxyalkylating the resulting carboxylic acid half esters with alkylene oxides in the presence of N-methylimidazole, triethylene diamine, triphenylphosphine or mixtures thereof with thiodialkylene glycol as catalysts.
摘要:
Disclosed are polyester polyols liquid at 25.degree. C., having an average functionality of from 2 to 3, a hydroxyl number of from 25 to 400, an acid number smaller than 10 and a viscosity at 25.degree. C. of from 200 to 10,000 mPas, which contain in bonded form units having at least one of the structures--O--CH.sub.2 --CH(CH.sub.3)--CH.sub.2 --CH.sub.2 --CH.sub.2 --O--,--O--CH.sub.2 --CH(C.sub.2 H.sub.5)--CH.sub.2 --CH.sub.2 --O--,--OC--CH(CH.sub.3)--CH.sub.2 --CH.sub.2 --CO--and--OC--CH(C.sub.2 H.sub.5)--CH.sub.2 --CO--which are prepared by the polycondensation or transesterification of 2-methyl-1,5-pentanediol, 2-ethyl-1,4-butanediol, 2-methyl-glutaric acid and/or 2-ethyl succinic acid or their derivatives, optionally while using other organic polycarboxylic acids and multivalent aliphatic alcohols and are useful for preparing non-cellular or cellular polyurethane plastics or polyurethane-polyurea plastics.
摘要:
Polyester polyols and/or polyester-polyether polyols are prepared by reacting polyols preferably di- to hexafunctional polyether polyols with hydroxyl numbers of 30 to 200 with at least one carboxylic anhydride, preferably glutaric anhydride, resulting in a carboxylic acid half ester which is subsequently oxyalkylated with at least one alkylene oxide, preferably ethylene oxide in the presence of at least 1 thiodialkylene glycol, preferably thiodiethylene and/or thiodipropylene glycol.
摘要:
For the preparation of elastic flexible polyurethane foams with improved breaking elongation and very good setting behavior as well as densities from 7 to 120 grams per liter, organic polyisocyanates are reacted in the presence of blowing agents, catalysts and, optionally, auxiliaries and/or additives with polyols based on polyoxyalkylene polyols having terminal oxyethylene blocks of a degree of oxyethylation of 1 to 13 and which have a content of primary hydroxyl groups at the corresponding degree of oxyethylation equal or exceeding the value of curve A in the Figure in which curve A describing the relationship of the content of primary hydroxyl groups with the degree of oxyethylation.