To provide a PTFE aqueous dispersion which is excellent in mechanical stability, while being not susceptible to foaming. A polytetrafluoroethylene aqueous dispersion which is characterized by containing from 15 to 70 mass % of PTFE particles having an average primary particle diameter of from 0.1 to 0.5 μm; from 0.1 to 20,000 ppm, to the PTFE particles, of a fluorinated emulsifier selected from a C.sub.4-7 fluorinated carboxylic acid which may have an etheric oxygen atom, and salts of thereof; from 1 to 20 parts by mass, to 100 parts by mass of the PTFE particles, of a nonionic surfactant represented by R.sup.1—O-A-H (wherein R.sup.1 is a C.sub.8-18 alkyl group, and A is a polyoxyalkylene chain); from 0.004 to 0.040 parts by mass, to 100 parts by mass of the PTFE particles, of a polyether polysiloxane copolymer, wherein the polyether chain consists solely of a polyoxypropylene group; and water.

The present invention relates to processes for the preparation of polyurethane foams comprising a step wherein a chemical compound with a low particle size releases a chemical and/or physical blowing agent by decomposition, polyurethane foams prepared by such processes as well as compositions comprising at least one polyol and a chemical compound with a low particle size capable of releasing a chemical and/or physical blowing agent by thermally- and/or chemically-induced degradation and uses of such compositions.

A reactive composition is disclosed for making a polyisocyanurate-polyurethane comprising rigid foam (PIR-PUR), said reactive composition comprising a polyisocyanate composition, an isocyanate-reactive composition, at least one catalyst compound suitable for making the PIR-PUR comprising foam, at least one blowing agent; and optionally one or more surfactants, one or more flame retardants, one or more antioxidants, or combinations thereof characterized in that the reactive composition further comprises a reactive viscosity reducer selected from at least one acrylate and/or methacrylate compound having no isocyanate-reactive groups and having a viscosity at 25° C. below 100 mPa.Math.s.

The present invention relates to the field of polyol components suitable for forming polyurethane foam, in particular two component polyurethane foam the resulting foams and methods for their production. The present inventors found gaseous hydrohaloolefin containing polyol components possessing improved shelf-life properties, in particular polyol components comprising a gaseous hydrohaloolefin blowing agent, a nitrogen catalyst and a tin catalyst, wherein the tin catalyst comprises a sulfur atom. The present inventors also found that the shelf-life is further improved if the nitrogen catalyst is at least partially protonated by reaction with an acid, such as an organic acid.

To produce quickly and easily an open cell rigid polyurethane foam having a uniform and low density, a method for producing an open cell rigid polyurethane foam is provided, the method comprising foaming a mixed liquid of (1) a polyol-containing component comprising (a) a polyol mixture, (b) a catalyst, and (c) a foaming agent (c), and (2) a polyisocyanate component. The foaming agent consists of water and an adduct of a primary or secondary amine compound and carbon dioxide, the amount of the water is 10 to 80 parts by mass based on 100 parts by mass of the polyol mixture, and the amount of the adduct is 1 to 20 parts by mass based on 100 parts by mass of the polyol mixture.

The present invention relates to open- and fine-celled rigid polyurethane foams which contain not only urethane groups (PUR) but also isocyanurate groups (PIR) and carbodiimide groups (CD) and to the use thereof in vacuum insulation panels.

Disclosed are methods for formulating a polyisocyanurate foam-forming composition with good low temperature insulation performance. The polyisocyanurate foam-forming composition includes: a) an organic polyisocyanate, b) a polyol composition comprising at least one polyester polyol with a nominal hydroxyl functionality of at least 2.0, c) a blowing agent composition present in an amount sufficient to produce foam having a density of less than 1.85 lb/ft3 and comprising: (1) a hydrocarbon having an atmospheric pressure boiling point of at least 68° F. (20° C.), and (2) water, d) a trimerization catalyst, e) a flame retardant, and f) a silicone surface-active agent. The methods include: (A) evaluating a measured Relative Hydrocarbon Solubility and, optionally, evaluating a measured a Surfactant Water Solubility, a Surfactant Turbidity, or evaluating both the Surfactant Water Solubility and the Surfactant Turbidity; and (B) formulating the polyisocyanurate foam-forming composition with the silicone surface-active agent in light of such evaluation.

The present invention relates to a super absorbent resin, and the super absorbent resin can exhibit a fast absorption rate and high gel strength even in a partially swollen state through the size optimization of partially swollen gel particles. Therefore, the use of the super absorbent resin can effectively prevent a rewetting phenomenon.

Disclosed is a method and system for supporting a pipeline in a trench. The disclosure is directed to the placement of urea-silicate sprayable or pumpable foams into trenches to provide pipeline pillow supports during placement of the pipeline and to form trench breakers in the trench prior to the trench being backfilled. The pillow supports and trench breakers inhibit erosion of the trench prior to and after being backfilled. The urea-silicate foam material has an open cell content of at least 50% to resist floatation, is non-flammable and electrically conductive. Also disclosed is use of supports for placement between the urea-silicate foam and the bottom of the trench to aid in utilization of the urea-silicate foams in cold weather conditions and in trenches with steeply sloped bottoms. Preferably the supports are biodegradable and electrically conductive when wet.

A process for producing rigid PUR/PIR foams comprising A1 an isocyanate-reactive component, A2 a flame retardant, A3 a blowing agent, A4 a catalyst, A5 optionally auxiliaries and additives, and B an organic polyisocyanate component. Component A1 comprises a triurethane triol A1.1 and a compound A1.2 selected from the group consisting of polyether polyol, polyester polyol, polyether carbonate polyol, and polyether ester polyol. Also disclosed is a rigid PUR/PIR foam, an insulating material, a composite element, and a mixture.