In the present invention, a multi-stage foam sound-absorbing black body material is provided for the first time. A graphene aerogel is introduced into a commercialized polymer foam skeleton by using a solvent plasticizing and foaming technology, so as to embed ultra-thin graphene drums in the foam skeleton. When sound waves enter the foam black body, a large number of graphene drums generate a severe resonance effect, thereby rapidly achieving attenuation of the sound waves, and combined with the friction loss of the porous structure of the polymer foam on the sound waves, excellent sound-absorbing performance is achieved in a wide frequency range. The present solution is provided on the basis of commercialized foam materials, has a simple method, low costs, and the potential of wide industrial application.

The present disclosure relates to a method for preparing high-performance melamine foam, comprising the following steps: preparing a primary polymer of waterborne melamine formaldehyde resin; uniformly mixing the primary polymer of the waterborne melamine formaldehyde resin, the polar solvent, the surfactant and the additive to obtain a mixture A; uniformly mixing the mixture A with the solid methylol melamine to obtain a mixture B; uniformly mixing the mixture B with the foaming agent to obtain a mixture C; uniformly mixing the mixture C with the curing agent to obtain a mixture D; and carrying out microwave radiation, foaming, curing, drying and quenching on the mixture D in a microwave foaming device to obtain the high-density melamine foam. The melamine foam described in the present invention has high density and high strength performance.

The present invention provides an aqueous coating composition that exhibits a small change in viscosity and can form a coating film having a superior coating film appearance even when the amount of a solvent contained in the aqueous coating composition decreases due to the change of the coating environment. An aqueous coating composition containing a polyester resin dispersion (A) and a melamine resin (B), wherein the polyester resin constituting the polyester resin dispersion (A) contains an alkyd resin having an acrylic vinyl-based polymer segment; the melamine resin (B) contains a hydrophobic melamine resin; as to a viscosity of a dry coating film of the coating composition, a coating film viscosity η1 of a dry coating film whose solid content is 60% by mass and a coating film viscosity η2 of a dry coating film whose solid content is 80% by mass satisfy the following condition:

1≤η2/η1≤10, where the coating film viscosities η1 and η2 are viscosities measured at a temperature of 25° C. and a shear rate of 0.1 sec.sup.−1.

The present invention relates to a cleaning implement that includes a melamine-formaldehyde foam. The melamine-formaldehyde foam cleaning implement has a d90/d10 ratio above 1.65 and a compression deflection force above 3.25 psi. Additionally the present invention encompasses processes for making and methods for cleaning hard surfaces with a cleaning implement according to the present invention.

A process for producing a melamine-formaldehyde foam by heating and foaming an aqueous mixture M using microwave radiation, said mixture M comprising at least one melamine-formal-dehyde precondensate, at least one curative, at least one surfactant, at least one blowing agent and at least one linear polymer with a number average molecular weight M.sub.n in the range from 500 to 10,000 g/mol and at least two functional groups selected from OH, NH.sub.2 or COOH as well as a melamine-formaldehyde foam obtainable by this process and its use.

A melamine/formaldehyde foam having an open-cell foam structure, with an impregnation applied to the foam structure that comprises at least one particulate phyllosilicate surface-modified with aminosilane and at least one anionically- and/or nonionically-stabilized polyurethane dispersion.

Provided herein is a composite material that includes at least one thermoresponsive polymer and at least one organic foam material. Further provided herein is a method for producing the composite material and also to the use of the composite material for cooling and for regulating temperature.

A method of manufacturing a laminate comprises providing a binder impregnated core layer by impregnating at least one fibrous layer with an aqueous core binder solution having a viscosity in the range 75 cP to 500 cP at a temperature of 20° C. and a bake-out solid content in the range 40 wt % to 85 wt %, in which the aqueous core binder solution comprises (i) at least 25% by dry weight of a) reducing sugar reactant(s) and nitrogen-containing reactant(s) and/or b) curable reaction product(s) of reducing sugar reactant(s) and nitrogen-containing reactant(s); and (ii) between 5% and 15% by weight of a non-aqueous solvent based on the total weight of the aqueous binder solution; providing a semi-finished assembly by assembling the binder impregnated core layer with a surface layer; and applying heat and pressure to the semi-finished assembly to cure the binder in the binder impregnated core layer and secure the core layer and the surface layer together.

A triazine ring-containing phenol resin obtained by reacting melamine, para-alkylphenol, and formalin is used to provide an epoxy resin composition capable of providing a cured product with excellent flame retardancy, excellent dielectric characteristics such as a low dielectric tangent and a low dielectric constant, and excellent thermal conductivity, a cured product thereof, and a prepreg, a circuit board, a build-up film, a build-up board, a semiconductor sealing material, a semiconductor device, a fiber reinforced composite material, and a formed article using the epoxy resin composition.

The aim of the invention is to provide polyester/primer/metallic coating composite films having good adherence of the metallic coating in dry and humid conditions. Said films also form a good gas barrier: oxygen permeability less than or equal to 0.8 cc/m2/d; water vapour permeability less than or equal to 0.3 g/m2/d. To this end, the invention concerns a composite film comprising a polyester substrate, at least one coating adhering on at least one of the faces of the substrate and at least one layer of primer for cross-linked adhesion between the substrate and the coating. Said primer comprises at least one acrylic and/or methacrylic polymer P1, at least one acrylic and/or methacrylic polymer P2 different from P1, at least one cross-linking agent, and, preferably, at least one polyester that is soluble or dispersible in water: —P1 having a gel content TG1>70% by dry weight with respect to P1; —P2 having a gel content TG2≤TG1 and ≤20% by dry weight, with respect to P2; —P1 having a surface-grafted free weak acid content≥0.8 in meq/g of polymer; —[P2]≤60% by weight on dry by weight in respect to P1+P2. The method for producing said film, the adhering primer, and the articles obtained using said film, also form part of the present invention.