The invention relates to a potting paste composition for honeycomb reinforcement having improved fire retardancy characteristics. The potting paste composition comprises (a) a curable polymer; (b) a curing agent for the curable polymer; (c) a fire retardant comprising an ammonium polyphosphate in combination with an ingredient selected from the group consisting of metal hydroxides, expandable graphites, liquid phosphate esters, phosphorous organic compounds or salts thereof, and zeolites; and(d) a filler selected from the group consisting of polymeric microspheres, hollow glass microspheres, and thixotropic fillers; wherein the potting paste has an uncured density determined by the method according to EN ISO 1183 of not more than 0.7100 g/cm.sup.3, preferably of at most 0.680 g/cm.sup.3, more preferably of at most 0.673 g/cm.sup.3, still more preferably of at most 0.660 g/cm.sup.3, even more preferably of at most 0.658 g/cm.sup.3, yet more preferably of at most 0.653 g/cm.sup.3 and in particular of at most 0.620 g/cm.sup.3; and wherein the total content of the fire retardant is at least 5.0 wt.-%, preferably at least 10 wt.-%, more preferably at least 15 wt.-%, relative to the total weight of the potting paste composition.

The disclosure provides a forming method of a halogen-free flame-retardant material. The method includes the followings. A twin-screw extruder including a first zone and a second zone is used. A mixture in the first zone is mixed, melted and heated to form a molten mixture. The mixture includes a halogen-free flame retardant, a wear-resistant modifier, a thermoplastic elastomer, and an antioxidant. In addition, a silane-modified nano-silica aqueous suspension is introduced into the second zone to mix the silane-modified nano-silica aqueous suspension with the molten mixture from the first zone. The first zone and the second zone are continuously connected regions.

A sealant material for sealing threaded pipe joints that is a multifilament or spun polyphenylene sulfide yarn and a joint sealing composition comprising a silicone oil or a natural oil with a smoke point of about 230° C. or higher. The polyphenylene sulfide yarn is coated with the joint sealant composition. The material forms an effective seal and is resistant even when used in systems in which it is exposed to temperatures in excess of 280° C. The material may be provided in a dispenser.

A resin composition including at least (A) an epoxy resin, (B) a curing agent and (C) an inorganic filler, satisfies the following conditions: (I-I) the minimum modulus is no greater than 10.sup.4 MPa when evaluated at a set temperature of 200° C. after temperature increase from room temperature to 200° C. at 50° C./min by evaluation with a rheometer, and the final modulus is 10.sup.5 MPa or greater from 10 minutes after the initial temperature increase; (I-II) the softening point of the epoxy resin (A) is 35° C. or higher; (I-III) the residual solvent in the resin composition is no greater than 0.1%; and (I-IV) the equivalent value of the curing agent (B) is no greater than 90 g/eq and the softening point is 105° C. or higher.

A one component spray polyurethane foam formulation containing a polymeric isocyanate with nominal functionality of 2.5 to 3.5, a polyol component that is at least 85 percent aliphatic and having a mole ratio of polyol with three or more functionality to total polyol of 0.2 to 0.75, 15-30 wt % of a plasticizer, 1.5-3.5 wt % phosphorous, 5.5 to 11.5 halogen and 1.5 to 5 millimoles of blowing agent per gram of formulation and that is free of expandable graphite achieves a B2 rating in DIN 4102 testing.

Rubber compounds with increased resistance to fire are disclosed. The rubber compounds are incorporated into fire seals and in particular into fire seals for aerospace applications. The advance rubber compounds are created by adding a powdered vitreous or glass material in combination with a fiber such as carbon fiber, with or without intumescent material to a base rubber compound and then curing.

A composition including a perfluoroelastomer, carbon black in an amount of 55 to 75 parts by weight per 100 parts by weight of the perfluoroelastomer, and a crosslinking agent represented by the following formula (1): wherein in the formula (1), A is a single bond, —O—, an alkylene group, or a fluoroalkylene group; R.sup.1, R.sup.2, and R.sup.3 are independently a hydrogen atom, a fluorine atom, an alkyl group, or a fluoroalkyl group; and provided that at least one of R.sup.1, R.sup.2, and R.sup.3 is a fluorine atom or a fluoroalkyl group.

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The present invention aims to provide a crystalline polyester resin which satisfies both of a high melting point and a high fluidity, and a flame-retardant sealing resin composition using the same. A crystalline polyester resin (A) containing polycarboxylic acid components and polyhydric alcohol components as copolymerizing components, characterized in that a copolymerizing rate of a 2,6-naphthalenedicarboxylic acid component is from 40 to 100 molar % when a total of the polycarboxylic acid components in the crystalline polyester resin (A) is taken as 100 molar %, that a 1,4-butanediol component is copolymerized as a polyhydric alcohol component, and that a copolymerizing rate of the 1,4-butanediol component is 40 molar % or less when a total of the polyhydric alcohol components is taken as 100 molar %.

The disclosure provides a forming method of a halogen-free flame-retardant material. The method includes the followings. A twin-screw extruder including a first zone and a second zone is used. A mixture in the first zone is mixed, melted and heated to form a molten mixture. The mixture includes a halogen-free flame retardant, a wear-resistant modifier, a thermoplastic elastomer, and an antioxidant. In addition, a silane-modified nano-silica aqueous suspension is introduced into the second zone to mix the silane-modified nano-silica aqueous suspension with the molten mixture from the first zone. The first zone and the second zone are continuously connected regions.

The present invention provides a synthetic resin composition from which a combustion residue produced by combustion is rigid. The synthetic resin composition of the present invention is configured such that the strength of the combustion residue of the composition after combustion in an atmosphere of 800° C. for 20 minutes is 0.5 N/mm.sup.2 or more. Thus, the combustion residue produced by combustion is very rigid. The combustion residue is capable of reliably holding a state where a joint part is filled therewith and clogged even during a fire, preventing flames from passing through a sealing part such as the joint part, and imparting excellent fire-proof performance to a wall part of a building construction.