Abstract:
The invention relates to a closed-cell extruded foam that can be produced by (a) heating a polymer constituent P formed from at least one alpha- methylstyrene-acrylonitrile copolymer (AMSAN), optionally at least one styrene- acrylonitrile copolymer (SAN), and optionally at least one thermoplastic polymer from the group consisting of styrene polymers and copolymers, polyacrylates, polycarbonates, polyesters, polyamides, polyether sulfones, polyether ketones and polyether sulfides, for forming a polymer melt, (b) introducing between 1 and 12 wt. % (in relation to P) of a foaming constituent T containing b1) between 15 and 95 wt. % (in relation to T) of carbon dioxide and b2) between 5 and 85 wt. % (in relation to T) of at least one co-foaming agent selected from the group consisting of C1-C4 alcohols and C1-C4 carbonyl compounds, into the polymer melts in order to form an expandable melt, (c) extruding the expandable melt in a region of lower pressure while expanding to form the extruded foam, and (d) optionally adding additives to the polymer constituent P in at least one of the steps a), b) and/or c). The foam obtained in this way is suitable as an insulating material and a structural foam.
Abstract:
The invention relates to a composite molded part, in particular for furniture construction, contains a core layer and one or more layers, wherein the core layer is designed as a closed-cell extrusion foam sheet having a cell count of 1-30 cells per mm and a density of 20-200 g/l and can be obtained by extrusion foaming a foamable melt, comprising (a) heating a polymer component P, which is composed of 85 to 100% by weight of component P', consisting of P1) 100 to 0% by weight (in relation to P') of one or more alpha-methyl styrene acrylonitrile copolymers (AMSAN), containing P11) 18 to 40% by weight (in relation to AMSAN) acrylonitrile embedded by polymerization, P12) 60 to 82% by weight (in relation to AMSAN) alpha-methyl styrene embedded by polymerization (P121) or a mixture, embedded by polymerization, of alpha-methyl styrene and styrene (P122), P13) 0 to 22% by weight (in relation to AMSAN) of at least one monomer embedded by polymerization from the group consisting of alkyl(meth)acrylates, (meth)acrylic acid, maleic acid anhydride and maleinimides, and P2) 0 to 100% by weight (in relation to P') of one or more styrene acrylonitrile copolymers (SAN), containing, preferably consisting of, P21) 18 to 40% by weight (in relation to SAN) acrylonitrile embedded by polymerization, P22) 60 to 82% by weight (in relation to SAN) styrene embedded by polymerization, and P23) 0 to 22% by weight (in relation to SAN) of at least one monomer embedded by polymerization from the group consisting of alkyl(meth)acrylates, (meth)acrylic acid, maleic acid anhydride and maleinimide, wherein the sum of the percentages by weight of P1 and P2 is 100% by weight, in relation to P', and P3) 0 to 15% by weight (in relation to P) of one or more thermoplastic polymers from the group consisting of styrene polymers and copolymers, polyolefins, polyacrylates, polycarbonates (PC), polyesters, polyamides, polyether sulfones (PES), polyether ketones (PEK) and polyether sulfides (PES), to form a polymer melt, (b) introducing 1 to 12% by weight (in relation to P) of a expanding agent component T, which preferably contains less than 0.2% by weight water (in relation to P), containing b1) 15 to 95% by weight (in relation to T) carbon dioxide and b2) 5 to 85% by weight (in relation to T) of one or more co-expanding agents selected from the group consisting of C 1 -C 4 alcohols and C 1 -C 4 carbonyl compounds, into the polymer melt to form a foamable melt, (c) extruding the foamable melt in a range of lower pressure to foam it into the extrusion foam, (d) optionally adding additives to the polymer component P in at least one of steps a), b) and/or c).
Abstract:
A process for producing an elastic silicate foam by foaming a mixture containing from 10 to 80% by weight of an aqueous dispersion A) of SiO 2 particles which have an average particle diameter in the range from 1 to 100 nm, from 5 to 30% by weight of a polymer B) dissolved in water, from 10 to 50% by weight of a blowing agent C), from 1 to 5% by weight of an emulsifier D), from 0.01 to 5% by weight of a crosslinker E) which is capable of reacting with the polymer B), and also the foam which can be obtained by the process and its use.
Abstract:
The invention relates to a coating composition containing at least one cross-linking agent and a hydrophobically acting amount of a compound containing silicon, to foam particles coated therewith, to molded foam bodies produced therefrom, and to the use thereof.
Abstract:
The invention relates to a method for the production of shaped foam bodies, comprising: provision of a composition having foam particles and binder; introduction of the composition into a space which is bounded on at least one side by a pressing surface; and exertion of pressure onto the composition by means of the pressing surface. The method further irradiation of microwaves through the pressing surface into the composition, while pressure is being exerted onto the composition. The invention furthermore relates to a device for carrying out the method according to the invention, having: at least one pressing surface and a counterbearing surface lying opposite, between which a space extends which is adapted to receive a composition of foam particles and binder. The pressing surface and counterbearing surface adjoin the space directly. The device further comprises at least one stiff layer which locally or entirely is essentially transparent for microwaves and has a surface facing toward the space, which is connected to the pressing surface in such a way as to transmit force. The device also comprises a microwave radiator unit which is arranged on a side of the stiff layer remote from the space and is aligned relative to the space in order to irradiate microwaves into the space through the stiff layer. Lastly, the invention relates to a microwave radiator unit for the heat treatment of foam compositions. The microwave radiator unit comprises a multiplicity of microwave antennas which are arranged in a plane array and at least two of which are connected through a distributor device to a common microwave signal source, which feeds the at least two antennas.
Abstract:
A method for producing foam by hardening mechanical or chemical foam made of an aqueous composition, wherein the aqueous composition has A) 40 to 95 parts by weight of an alkali silicate solution with a water content of 40 to 90% by weight, B) 0 to 60 parts by weight of a powdery alkali silicate with a water content of 0 to 30% by weight, C) 0 to 15 parts by weight of a surfactant, D) 5 to 40 parts by weight of an aqueous polymer dispersion with a solid matter content of 10 to 60% by weight, and the foams that can be obtained by the method and the use thereof as insulating boards.
Abstract:
The invention relates to a layer (A) containing: a1) at least one carrier material, a2) at least one compound selected from inteumescent materials, expanded graphites, borates, compounds containing phosphate, compounds containing silicate, or carbonising substances such as sugar or starch, and a3) at least one polymer that can be produced from at least one vinyl aromatic monomer.
Abstract:
The invention relates to expanded particulate moulded parts with a density ranging between 10 and 100 g/l. Said parts are obtained by welding pre-expanded particulate consisting of expandable thermoplastic polymer granulates, the latter containing between 5 and 100 wt. % styrene copolymer A), between 0 and 95 wt. % polystyrene B) and between 0 and 95 wt. % thermoplastic polymer C) that differs from a) and b). The invention also relates to methods for producing the expandable thermoplastic polymer granulates.
Abstract:
The invention relates to expandable polystyrene granulates with at least a bi- or multi-modal molecular-weight distribution, to a method for producing said granulates and to their use in the production of expanded particulate moulded parts.
Abstract:
The invention relates to expandable polyolefin particles containing expanding agents, said particles being coated with between 0.01 and 3 wt. % of a salt and/or an ester of a long-chained fatty acid, preferably with calcium stearate, in order to prevent agglutination during expansion.