Abstract: Structurally strong composite sandwich panels are made using phenolic resin adhesives to bond the face sheets to the honeycomb. Certain configurations and combinations of phenolic resins and fire protection agents were found to provide low flame, smoke and toxicity (FST) panels which have high structural strength.

Abstract: A method of producing a curable prepreg which comprises (i) sandwiching a multi-ply fabric layer comprising at least two superposed sheets of woven reinforcing fabric between solid films of a curable resin composition and (ii) heating the resulting sandwich under pressure so that the resin composition impregnates the sheets of woven reinforcing fabric to form a coherent curable structure.

Abstract: A method of producing a curable prepreg which comprises (i) sandwiching a multi-ply fabric layer comprising at least two superposed sheets of woven reinforcing fabric between solid films of a curable resin composition and (ii) heating the resulting sandwich under pressure so that the resin composition impregnates the sheets of woven reinforcing fabric to form a coherent curable structure.

Abstract: An improved honeycomb structure formed from a non-woven sheet material coated with a resin which contains particles of a polymeric material. The inclusion of solid polymeric particles in the resin coating was found to increase the strength and stiffness of the honeycomb without degrading compressive properties. Composite panels are also disclosed where the improved honeycomb structure is combined with one or more facing sheets.

Abstract: The modified advanced epoxide resins described, having an average molecular weight of up to 50,000, can be photopolymerized without the need to include photosensitizers. They may be prepared by reaction of a diepoxide ##STR1## with a keto group-containing dihydric phenol ##STR2## to form the advanced epoxide resin ##STR3## followed by condensation with an aldehyde RCHO to yield ##STR4## In the above formulae, R is an organic group which preferably has ethylenic unsaturation or heterocyclic aromaticity in conjugation with the indicated ethylenic double bond; R.sup.1 is the divalent residue linking two epoxide groups; R.sup.2 is preferably a hydrogen atom but may be an organic group, halogen, or cyano; R.sup.3 is a trivalent aromatic or heterocyclic group, especially a group ##STR5## If desired, other dihydric phenols can be employed with that containing a keto group, and condensation with the aldehyde may be carried out so that only some groups --COCH.sub.2 R.sup.2 undergo reaction.

Abstract: The resins are diepoxides of the formula ##STR1## where A IS AN INTEGER OF AVERAGE VALUE FROM 1 TO 100,Each R and R.sup.1 represents a group ##STR2## OR --O--(OC).sub.c --R.sup.5 --(CO).sub.c --O--, each R.sup.2 represents --H or a group --(CH.sub.2 NH).sub.d COC(R.sup.6).dbd.CH.sub.2, at least one of the 2a groups R.sup.2 representing --(CH.sub.2 NH).sub.d COC(R.sup.6).dbd.CH.sub.2,each R.sup.3 denotes a lower alkyl group, or conjointly each pair represents a group of formula --CH.sub.2 CH.sub.2 --, --C(R.sup.7 R.sup.8)CO--, ##STR3## --CH.sub.2 CH.sub.2 CH.sub.2 --, --COCO--, --COCOCO--, or --COC(OH).sub.2 CO--,R.sup.4 represents a divalent aliphatic, cycloaliphatic, or araliphatic radical,b, c, and d are each zero or 1,R.sup.5 represents a straight or branched chain aliphatic group or, providing c is 1, it may alternatively represent a group ##STR4## R.sup.6 represents --H or a lower alkyl group, and R.sup.7 and R.sup.8 each represent --H, --CH.sub.3, or --C.sub.2 H.sub.5.

Abstract: A method for the preparation of prepregs comprisesI. impregnating a fibrous reinforcing material with a liquid composition containing an epoxide resin, a photopolymerizable compound, and with a heat-activated curing agent for epoxide resins, andIi. in the absence of a substance which gives rise to a substantial degree of photoinduced polymerization through consumption of epoxide groups, exposing the impregnated material to actinic radiation such that the composition solidifies due to photopolymerization of the said photopolymerizable compound while the epoxide resin remains substantially in the thermosettable state.Preferably the liquid composition also contains a dual-functional substance which has in the same molecule both an epoxide group and a dissimilar group through which the substance can be photopolymerized. The prepreg, optionally after shaping and/or stacking, is heated to cure the epoxide resin and, if used, the photopolymerized dual-functional substance.

Abstract: Novel amides, preferably having a molecular weight in the range 1000 to 10,000, are prepared by acylating, partially or fully, amino groups in poly(ethylene imine) or poly(propylene imine) whereby amino-hydrogen atoms are replaced by groups R.sup.3 CH.dbd.CR.sup.2 CO--, where R.sup.3 denotes an aliphatic, cycloaliphatic, araliphatic, or heterocyclic group containing ethylenic unsaturation in conjugation with the indicated double bond and R.sup.2 denotes a hydrogen, chlorine, or bromine atom, a cyano group, or an alkyl group. Particularly preferred are such amides where R.sup.3 CH.dbd.CR.sup.2 CO-- denotes a sorbyl group and containing additional intramolecular linkages introduced by a difunctional reagent capable of reacting with aliphatic amino groups, such as a diepoxide or a di-isocyanate.The amides may be polymerized by means of actinic radiation and are useful in the preparation of printing plates and printed circuits.

Abstract: The esters are soluble in an aqueous solution of a base before exposure to actinic radiation but, on exposure to actinic radiation, polymerize and become insoluble in such an aqueous solution. Development of photopolymerized images does not therefore require the use of toxic or flammable organic solvents. They contain free carboxyl groups and at least one unit of the formula 1-IV ##STR1## where R.sup.1 is a carbon atom chain containing specified groupings, such as one of formula --CH.dbd.CH--CO--CH.dbd.CH--, --CH.dbd.CHCO--, --COCH.dbd.CHC.sub.6 H.sub.4 CH.dbd.CHCO--, or ##STR2## and Y is oxygen or sulfur. They are obtained by the reaction of an at least dianhydride of a polycarboxylic acid with alcoholic hydroxyl groups of an alcohol containing at least one unit of formula I-IV.

Abstract: A method of making a shaped article from particulate solid material, such as a foundry mould or core from sand, comprisesI. forming a mixture of the particles and an anaerobically-curing adhesive containing, as a curing accelerator, either an aliphatic amine having at least two primary aliphatic amino groups or a condensation product of such an amine with a ketone or with an aldehyde,Ii. forming the mixture into the desired shape, andIii. in the presence of water, causing the adhesive to cure and to bond the particles together by displacing air or other oxygen-containing gas in the environment of the shaped article with an inert gas or vapor.

Abstract: The products, which are based on polyepoxide, polymerize on exposure to actinic radiation and are useful in the preparation of printing plates for offset printing and of printed circuits, particularly multilayer circuits. They are formed by coupling two molecules of a polyepoxide by means of a dihydric phenol which contains a chalcone or chalcone-like grouping, such as 1,3-bis(p-hydroxyphenyl)prop-1-en-3-one or 1,5-bis(p-hydroxyphenyl) penta-1,4-dien-3-one, so sensitizing the material to the radiation, and then, to achieve polymerizability, ring-opening at least some of the residual epoxide groups so as to incorporate olefinic acyloxy groups (R.sup.6 CH=C(R.sup.5)COO-), such as sorboyl groups.

Abstract: Solid particulate materials are bonded together to form a foundry mold or core byI. forming a mixture of the particles and an anaerobically-curing adhesive and moulding the mixture to the desired shape, andIi. causing the adhesive to cure and bond the particles together by maintaining the shaped article in a substantially oxygen-free environment.The anaerobic adhesive may comprise, as monomer, an ester of an acrylic acid, with a hydroperoxide or peroxide as a polymerization catalyst, and the oxygen-free environment may be produced by displacing air with nitrogen or other inert gas or vapor.The method described is particularly suited for the production of foundry moulds and cores from sand or other particulate material.

Abstract: Contamination of anaerobically-curing adhesive compositions by minute traces of metals such as iron, either during manufacture or storage, can result in premature polymerization, the shelf life of the composition being severely shortened, or, at best, unpredictable.In the anaerobic adhesive composition now disclosed, at least part of the polymerizable monomer comprises a novel acrylate ester containing a structure of the formula ##EQU1## these esters being capable of chelating the metal contamination.

Abstract: A process for finishing keratinous material, especially rendering it shrink-resistant or imparting to it durably pressed effects, comprises1. treating the material with a polythiol ester of the formula ##EQU1## WHERE R.sup.1 represents an aliphatic or araliphatic hydrocarbon radical of at least 2 carbon atoms, which may contain not more than one ether oxygen atom,R.sup.2 represents a hydrocarbon radical,p is an integer of from 2 to 6,q is zero or a positive integer of at most 3, such that (p + q) is at most 6, andr and s each represent zero or 1 but are not the same, and2. curing the polythiol ester on the material by means of a polyene containing, per average molecule, at least two ethylenic double bonds each .beta. to an oxygen, nitrogen, or sulfur atom, the sum of such ethylenic double bonds in the polyene and of the mercaptan groups in the polythiol ester being more than 4 and the combined weight of the polyene and the polythiol ester being from 0.5 to 15% by weight of the keratinous material treated.

Abstract: Compounds having at least three 3-sorboyloxy-2-hydroxypropyl groups directly attached to ether oxygen atoms are polymerised by exposure to actinic radiation, preferably in the presence of a sensitiser such as Michler's ketone or benzoin. The compounds may be obtained by the reaction either of sorbic acid with a substance having at least three glycidyl ether groups or of glycidyl sorbate with a substance having at least three phenolic or alcoholic hydroxyl groups: if desired, not all of the glycidyl groups may be consumed, so that, after actinically-induced polymerisation, the epoxide-containing polymer may be cross-linked by reaction with a curing agent for epoxide resins.The compounds are useful in making printed circuits or printing plates for offset printing.