摘要:
The present disclosure is directed to a process for forming a reinforced ultraviolet (UV) radiation-curable composite. The composite may be formed by applying reinforcing layers and resin layers to a substrate. The resin composition may include an aliphatic urethane acrylate oligomer, a polyfunctional acrylate monomer, and a photoinitiator. The composite formed on the substrate may be exposed to UV radiation to cure the composite on the substrate. The composite may be characterized in that it is cured within 10 minutes of exposure to UV radiation and does not exhibit oxygen inhibition effects, such as, for example, surface tack. The reinforced UV-curable composite may find utility, for example, as a rapid field repair patch in aerospace applications, among others.
摘要:
The present disclosure is directed to a process for forming a reinforced ultraviolet (UV) radiation-curable composite. The composite may be formed by applying reinforcing layers and resin layers to a substrate. The resin composition may include an aliphatic urethane acrylate oligomer, a polyfunctional acrylate monomer, and a photoinitiator. The composite formed on the substrate may be exposed to UV radiation to cure the composite on the substrate. The composite may be characterized in that it is cured within 10 minutes of exposure to UV radiation and does not exhibit oxygen inhibition effects, such as, for example, surface tack. The reinforced UV-curable composite may find utility, for example, as a rapid field repair patch in aerospace applications, among others.
摘要:
The present invention provides a low density, semi-rigid polyurethane foam made from the reaction product, at an isocyanate index of from about 100 to about 150, of at least one polyisocyanate and an isocyanate-reactive blend containing from about 15 wt. % to about 55 wt. %, based on the weight of the resin, of a difunctional or greater functionality polyether polyol, from about 3 wt. % to about 19 wt. %, based on the weight of the resin, of at least one polyether tetrol, and from about 7 wt. % to about 39 wt. %, based on the weight of the resin, of at least one non-halogenated polyester polyol in the presence of from about 5 wt. % to about 30 wt. %, based on the weight of the resin, of at least one non-hydroxy functional flame retardant and from about 1 wt. % to about 20 wt. %, based on the weight of the resin, of at least one cross linking agent, and optionally in the presence of one or more of catalysts, surfactants, chain extenders and blowing agents, wherein the semi-rigid polyurethane foam having a density of from about 2 to about 25 pcf meets at least a V-1 class rating in accordance with UL 94 V flammability testing. The low density, semi-rigid polyurethane foams of the present invention may find use in producing lightweight, rapidly erected barriers for protection of people such as soldiers, police officers and fire fighters from pursuit by adversaries. Barriers made with the inventive foam may also be used to limit access to already secured areas.
摘要:
A method for making an energy-absorbing foam having a density that is less than about 7 pcf that exhibits excellent strength properties and that is particularly suitable for automobile bumper applications. The invention is also directed to the energy-absorbing foam made with the method.
摘要:
The present invention is directed to an isocyanate reactive mixture comprising from about 17 to about 85% by weight of one or more non-filled polyether polyols having a hydroxyl functionality of from 1.5 to 3 and molecular weights of from 1,500 to 8,000; from about 12 to about 80% by weight of one or more non-tertiary amine containing polyether polyols having a hydroxyl functionality of from 3 to 8 and a molecular weight of from 150 to 1,000; from about 0 to about 4% by weight of one or more primary or secondary diamines or amino alcohols and from 3 to about 12% by weight of water. The invention is also directed to a water-blown, energy absorbing foams made from the isocyanate reactive mixture.
摘要:
This invention relates to a process for the preparation of cast elastomers comprising reacting in an open mold at an isocyanate index of about 90 to about 110(a) an organic polyisocyanate;(b) an aminocrotonate-terminated polyether having a molecular weight of from about 1200 to about 6500 and having the formula ##STR1## wherein A is the m-functional group left by the removal of the hydroxyl groups of a polyether polyol having a number average molecular weight of from 1000 to 6000,R is the difunctional residue of certain aromatic diamines having the formula H.sub.2 N--R--NH.sub.2 such that each free --NH.sub.2 group of the aminocrotonate-terminated polyether has a moderated reactivity toward the organic polyisocyanate, as indicated by a gel time of about 60 to about 300 seconds (measured at 90.degree.-110.degree. C. in the absence of a slower reacting chain extender or crosslinker), andm is a number of from 2 to 8; and(c) a chain extending agent having a molecular weight of from 62 to 400, optionally in admixture with 0 to about 30% by weight, relative to the chain extending agent, of a crosslinking agent having a molecular weight of from 300 to about 500.
摘要:
This invention relates to a process for the preparation of an isotropic rigid foam comprising the step of reacting: (A) an organic polyisocyanate component selected from the group consisting of: (1) a polymethylene poly(phenylisocyanate) and (2) an NCO-terminated prepolymer, and comprising the reaction product of: (a) a polyester comprising the reaction product of (i) pure ortho-phthalic acid or phthalic anhydride and (ii) a glycol and (b) a polymethylene poly(phenylisocyanate); with (B) an isocyanate-reactive component comprising: (1) a liquid OH-terminated prepolymer having a viscosity of more than about 100,000 mPa·s at 25° C., and which comprises the reaction product of: (a) an organic aromatic polyisocyanate component; and (b) an amine initiated polyether polyol component; (2) at least one polyether polyol and optionally (3) at least one aromatic polyester polyol; in the presence of: (C) at least one catalyst; and (D) at least one blowing agent; wherein the relative amounts of components present is such that the Isocyanate Index is from 90 to 170. This invention also relates to the isotropic rigid foams prepared thereby.
摘要:
This invention relates to a process for preparing polyurethane elastomers comprising reacting in an open mold at an isocyanate index of about 90 to about 110(a) an isocyanate prepolymer having an isocyanate content of about 2 to about 15% by weight and a molecular weight of from about 500 to about 5000 prepared by reaction of(i) at least one organic polyisocyanate with(ii) at least one isocyanate-reactive compound having at least two isocyanate-reactive groups and a molecular weight of from about 250 to about 4000;with(b) certain aminocrotonate-terminated polyethers having a molecular weight of from about 500 to about 1500;(c) optional chain extenders and/or crosslinkers other than aminocrotonate-terminated polyether (b); and(d) optional auxiliaries and/or additives.