Abstract:
Disclosed is a thermally expandable composition, comprising at least one polymer P, cross-linkable by peroxide, and between 1 wt.-% and 2.5 wt.-%, based on the total weight of the composition, of at least one acrylate A, and between 0.2 wt.-% and 2.5 wt.-%, based on the total weight of the composition, of at least one peroxide, and at least one blowing agent, characterised in that the equivalent ratio of said peroxide to said acrylate A is between 0.01 and 0.5, preferably between 0.13 and 0.41, and the weight ratio of said peroxide to said acrylate A is lower than 0.33 and said polymer P comprises or essentially consists of at least two polymers PI and P2, wherein PI exhibits a melt flow index (MFI) of between 100 and 200 g/10 min, and P2 exhibits a melt flow index of between 0.1 and 60 g/10 min, wherein MFI is determined by ASTM D1238. The thermally expandable composition shows excellent properties in terms of expansion stability and minimised buckling and is especially suitable for baffle and/or reinforcement elements, e.g. in automotive manufacturing.
Abstract:
A composition includes an epoxy-based curable adhesive having at least one an epoxy resin modified acrylonitrile-butadiene copolymer and at least one thermoplastic elastomer. The at least one thermoplastic elastomer is present in the curable adhesive as a penetrating polymer network. Further, an expandable article is composed of the composition, a reinforcing element includes a support and an expandable article, a method for reinforces cavities of structural components, and the composition is used as a shape memory material.
Abstract:
A hem-curing epoxy resin composition, that includes an epoxy resin A having more than one epoxy group per molecule on average; a curing agent B for epoxy resins, which is activated at a temperature in a range of 100° C. to 220° C.; and an activator C for epoxy resin compositions, wherein activator C is a compound of formula (I), or is a reaction product between a compound of formula (Ia) and an isocyanate or an epoxide.
Abstract:
A reinforcing element for reinforcement in cavities of structural components including a substrate made of a plastics material, which is at least partially coated with a metal; and a foamable, thermosetting structural adhesive which is applied to the metal coating of the substrate; or a thermosetting structural adhesive which is applied to the metal coating of the substrate and is designed as a shape memory material.
Abstract:
A thermally expandable composition includes at least one polymer P cross-linkable by peroxide, and at least one acrylate, and at least one peroxide, azodicarbonamide and a zinc compound. The thermally expandable composition leads to low odor formation and low ammonia emission during and after the foaming process. The thermally expandable composition further shows excellent properties in terms of expansion stability.
Abstract:
Heat-curing epoxy resin compositions are characterized by high impact strength, good storage stability, and a low curing temperature. The epoxy resin compositions are suitable for use as a construction shell adhesive and for producing structural foams. They can already be cured in so-called bottom-baking conditions. Furthermore, it has been found that the use of an accelerator of the formula (Ia) or (Ib) results in an increase of the impact strength of heat-curing epoxy resin compositions.
Abstract:
What is described is a polymer which is a polyurethane polymer having blocked isocyanate groups or a reaction product of said polyurethane polymer with at least one epoxy resin, where the polyurethane polymer having blocked isocyanate groups is an addition product formed from at least one polyisocyanate and at least one polyester polyol, wherein the isocyanate groups of the addition product have been blocked by reaction with at least one aromatic compound having at least one hydroxyl group. Such a polymer is suitable as an impact modifier in epoxy resin compositions, especially when they are used as adhesives or structural foams. The polymer improves the corrosion resistance and vertical expansion of the epoxy resin composition.
Abstract:
The present invention relates to expandable compositions in the form of granular materials that are based on epoxy resins with a content of binders and curing agents for curing the epoxy resin. Corresponding compositions can be readily introduced into hollow bodies, for example, into sticks or roof supports and expanded to a foam by heating the composition and cured. This results in hollow bodies filled with foam that are distinguished by significantly improved mechanical properties compared to comparable hollow bodies without a foam filling. At the same time, the granular materials according to the invention can be very readily processed without a complex and expensive two-component injection-molding process being necessary.