摘要:
Compositions of N(CF.sub.3).sub.a (CHF.sub.2).sub.b (CH.sub.2 F).sub.c, where a, b and c are integers from 0 to 3 and a+b+c=3, and C.sub.n F.sub.m H.sub.2n+2-m, where n is an integer from 1 to 3 and m is an integer from 1 to 8, are disclosed. Also disclosed are compositions of N(CF.sub.3).sub.3 and butane, cyclopropane, dimethyl ether or isobutane. These compositions are useful as refrigerants, cleaning agents, expansion agents for polyolefins and polyurethanes, aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, and displacement drying agents.
摘要翻译:N(CF 3)a(CHF 2)b(CH 2 F)c的组成,其中a,b和c是0-3的整数,a + b + c = 3,CnFmH2n + 2-m,其中n是 1〜3,m为1〜8的整数。 还公开了N(CF 3)3和丁烷,环丙烷,二甲醚或异丁烷的组合物。 这些组合物可用作制冷剂,清洁剂,聚烯烃和聚氨酯的膨胀剂,气溶胶推进剂,传热介质,气体电介质,灭火剂,动力循环工作流体,聚合介质,微粒去除流体,载体流体,抛光研磨剂, 和置换干燥剂。
摘要:
A thermoformable, rigid or semi-rigid polypropylene foam sheet having a smooth surface and a uniform cell structure and a density of at least 2.5 lbs/ft.sup.3 is prepared by extruding a mixture of a nucleating agent, a physical blowing agent and a polypropylene resin having a high melt strength and high melt elasticity.
摘要翻译:通过挤出成核剂,物理发泡剂和聚丙烯树脂的混合物制备具有光滑表面和均匀泡孔结构和至少2.5lbs / ft 3的密度的可热成型,刚性或半刚性聚丙烯泡沫板,其具有 高熔体强度和高熔体弹性。
摘要:
The invention relates to a process for producing foams based on polyisocyanates by reacting polyisocyanates, compounds having at least two hydrogen atoms reactive towards isocyanate groups, blowing agents and, if appropriate, further additives. In this process, a blowing agent is used which is composed to the extent of at least 10 mol % of one or more fluorinated ethers of the formulaC.sub.a H.sub.b F.sub.c --O--C.sub.d H.sub.e F.sub.fwhere______________________________________ a = 1-6 d = 1-2 b = 1-12 e = 0-5 c = 1-12 f = 0-5. ______________________________________
摘要翻译:本发明涉及通过使多异氰酸酯,具有至少两个对异氰酸酯基团具有反应性的氢原子的化合物,发泡剂和(如果合适的话)其它添加剂反应来制备基于多异氰酸酯的泡沫的方法。 在该方法中,使用发泡剂,其至少为10摩尔%的一种或多种式CaHbFc-O-CdHeFf的氟化醚的程度,其中-a = 1-6d = 1-2-b = 1-12 e = 0-5 -c = 1-12 f = 0-5。 -
摘要:
Azeotropic mixtures of perfluoro-dimethylcyclobutane with 1,1-dichloro-1-fluoroethane or dichlorotrifluoroethane, are useful in solvent cleaning applications, and as refrigerants, aerosol propellants and polymer blowing agents.
摘要:
Improved reexpandable shrunken foam bodies of styrene-acrylonitrile type resin possessing an ability to reexpand to the original volume of the highly foamed state when left standing at room temperature under atmospheric pressure and a method for the manufacture of such reexpandable shrunken foam bodies.The aforementioned shrunken foam bodies are obtained by causing a styrene-acrylonitrile type resin to contain a prescribed large amount of a specific foaming agent exhibiting a slow gas permeation speed to the base resin and possessing the boiling point exceeding a fixed lower limit, heating the resin with steam thereby setting it to foam highly, and releasing the foamed resin into the atmosphere to be cooled and shrunk therein.The aforementioned shrunken foam bodies are convenient for the purpose of transportation and storage. They are useful as fillers intended to absorb shocks and insulate heat. The foam bodies, when reexpanded, form useful materials used for in-mold shaped articles designed for absorbing shock and insulating heat.
摘要:
A mixture of CFC-113 and CFC-123 and/or CFC-123a where CFC-123 or CFC-123a is a significant portion of the total composition has been found to result in improved blowing agent performance in phenol-formaldehyde foams compared to CFC-113.The use of CFC-123 (or CFC-123a, or both), in combination with CFC-113 improves resole resin solubility and mixed ingredient solution stability, prior to foaming. In addition, because of the lower molecular weight of CFC-123 (or CFC-123a) compared to CFC-113 better blowing agent efficiency will be realized per unit weight. Also, the lower boiling points of CFC-123 and CFC-123a as compared to CFC-113 results in a more ready conversion of dissolved blowing agent to released gaseous blowing agent by the exothermic phenolic resin polymerization. And because of the lower molecular weight and lower boiling point factors, a lower density foam is realized.
摘要:
A process for manufacturing foamed silicone compositions by foaming a cross-linkable composition which comprises:(a) 100 parts by weight of a vinyl-containing polysiloxane containing 0.0002 to 3% by weight of vinyl groups and a viscosity of from 0.1 to 1,000 Pascal-seconds at 25.degree. C.,(b) up to 10 parts by weight of a silanol-containing silicon compound with a viscosity from 0.01 to 10 Pascal-seconds at 25.degree. C.,(c) up to 200 parts by weight of filler,(d) 1 to 50 parts by weight of a polysiloxane with a viscosity of 0.005 to 0.1 Pascal-seconds at 25.degree. C., and(e) a platinum catalyst, is characterized by foaming the cross-linkable composition with a substance containing hydroxyl groups at temperatures of 50.degree. to 150.degree. C.
摘要:
A process for producing a polypropylene-polystyrene interpolymer which can be impregnated with a blowing agent and can then be expanded under normal conditions for polystyrene particles to low density, fine cell structure foams. The interpolymer is viscbroken during the polymerization of the styrene. The polypropylene is lubricated prior to formation of the interpolymer. The process forms particles which can be impregnated with blowing agent directly.
摘要:
A method for determining the optimum component ratios in an exothermic process for producing polyurethane foam is described which consists of continuously measuring the temperature differential with respect to time and then determining the optimum component ratios by comparing the maximum value of each of the sequential temperature differential peaks and the times at which they occur.
摘要:
In a method of producing a plate-like polystyrene resin foam which comprises extruding a molten mixture of a polystyrene resin and a volatile blowing agent from an extruder into a zone kept at a lower pressure than the inside of the extruder, the improvement wherein the volatile blowing agent is a mixture consisting of 50 to 80% by weight of dichlorodifluoromethane and 50 to 20% by weight of ethyl chloride and is present in said molten mixture in a proportion of 8 to 17 parts by weight per 100 parts by weight of the polystyrene resin.