Surfaces containing coupling activator compounds and reinforced composites produced therefrom

Abstract

The invention relates to products and processes employing coupling activator compounds represented by the following formula I:S—X-A  (I)wherein S represents a silane coupling moiety capable of bonding with the surface of an inorganic substrate, A represents a ring-opening polymerization activator moiety, or blocked precursor thereof, and X represents a linking moiety. Substrates containing the coupling activator compounds are useful in preparing reinforced resins.

Description

BACKGROUND OF THE INVENTION[0001]It is well-known to employ inorganic materials in composite articles to strengthen and reinforce the articles. In addition to increased dimensional stability, addition of the inorganic material provides polymer composites with significantly improved physical and mechanical properties. As one example, glass fibres may be placed into a polymer matrix where the high tensile strength of glass causes the composite to become more rigid. The glass fibres incorporated in the polymer matrix may take various forms: continuous or chopped strands, rovings, woven or non-woven fabrics, continuous or chopped strand mats, etc.[0002]Conventionally, glass fibres are formed by attenuating streams of a molten glass material from a bushing or orifice. The glass fibres may be attenuated by pulling by a winder, which collects filaments into a package or by other equipment or method capable of pulling the fibres. A sizing composition, or chemical treatment, is typically app...

AI Technical Summary

Benefits of technology

[0011]Blocked precursors of coupling activator compounds may include isocyanates blocked with compounds other than the activator compound. Under the processing conditions, such blocked isocyanate would become unblocked to furnish free isocyanate. The isocyanate may, under the reaction conditions, become blocked with the monomer thus forming the polymerisation activator. The silane functionality of the isocyanate compound may react with the substrate, such as glass, thus leading to improved interfacial adhesion.

[0012]In another embodiment, the invention provides a process for preparing a reinforced resin material, e.g. a glass-reinforced resin polyamide. A sizing composition comprising a coupling activator compound of formula I above may be applied to a glass substrate. In one embodiment, the sized glass substrate may be mixed with a lactam monomer, e.g. caprolactam, and a polymerization catalyst to form a polymerization mixture that may then be exposed to conditions sufficient to cause an in situ anionic ring-opening polymerization of the lactam monomer. In another embodiment, the sized glass substrate may be mixed with a cyclic olefin monomer, e.g. norbornene, and a polymerization catalyst to form a polymerization mixture that may then be exposed to conditions sufficient to cause an in situ ring-opening metathesis polymerization of the cyclic olefin monomer. The resulting composite products comprise a matrix in which the glass substrate is grafted onto the polymer, thereby substantially improving the coupling between the glass and the polymer. This improved coupling is expected to provide tougher composite materials.

Problems solved by technology

There is a need to provide glass-reinforced polyamide composites with high glass loading; however, one of the barriers is the high polymer viscosity of the polyamide in the molten state.

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