Preparing glass flake reinforced reaction injection molded polymers

Claim 1

A method of molding a reinforced polymeric panel by injecting a hardenable liquid polymer precursor carrying high aspect ratio glass flake particles into a mold cavity defining said panel, the initial injection pressure of said glass flake carrying liquid being at least about 2000 pounds per square inch, causing said liquid to flow away from the point of injection such that said glass flakes are layered with their planar surfaces substantially parallel to the planar surfaces of the panel as the mold is filled, and immediately gelling said liquid precursor in the mold such that the glass flakes are captivated in the hardened polymeric panel in said layered positions, the amount of said glass flake dispersed in said precursor being such that the hardened panel has a reduced coefficient of thermal expansion in all directions in the plane of the panel compared to a like unfilled panel and a substantially less wavy surface than a like glass fiber filled panel both having been molded from the liquid polymer precursor in like manner.

Claim 2

A method of molding a reinforced polymeric panel by injecting a hardenable liquid polymer precursor carrying high aspect ratio glass flake particles into a mold cavity defining said panel, the initial injection pressure of said glass flake carrying liquid being at least about 2000 pounds per square inch, causing said liquid to flow away from the point of injection such that said glass flakes are layered with their planar surfaces substantially parallel to the planar surfaces of the panel as the mold is filled, and immediately gelling said liquid precursor in the mold such that the glass flakes are captivated in the hardened polymeric panel in said layered positions, the amount of said glass flake dispersed in said precursor being such that the hardened panel has a reduced coefficient of thermal expansion in all directions in the plane of the panel compared to a like unfilled panel and a substantially less wavy surface than a like glass fiber filled panel both having been molded from the liquid polymer precursor in like manner.

Claim 3

A method of molding an internally reinforced polyurethane panel comprising dispersing a reinforcing amount of high aspect ratio glass flake into one or both of the liquid polyol and isocyanate precursor constituents for said urethane polymer, rapidly mixing said polyol and isocyanate precursors at a pressure of at least 2000 psi to form a chemically reactive urethane-forming liquid mixture, immediately injecting said liquid mixture into a mold for a said panel under pressure such that the mixture flows away from the injection port and causes the glass flake particles dispersed therein to be layered within the mold with their planar surfaces substantially parallel to the planar surfaces of the panel before gelation of the constituents, allowing said polyol isocyanate mixture to chemically react in the mold such that a hardened polymeric urethane panel is formed wherein said glass flakes are incorporated in their layered and surface parallel orientations, whereby the hardened urethane panel has a substantially wave free surface as molded and a substantially reduced coefficient of thermal expansion in all directions in the plane of the panel as compared to a like unfilled panel molded of like urethane constituents in like manner.

Claim 4

A method of molding an internally reinforced polyurethane panel comprising dispersing a reinforcing amount of high aspect ratio glass flake into one or both of the liquid polyol and isocyanate precursor constituents for said urethane polymer, rapidly mixing said polyol and isocyanate precursors at a pressure of at least 2000 psi to form a chemically reactive urethane-forming liquid mixture, immediately injecting said liquid mixture into a mold for a said panel under pressure such that the mixture flows away from the injection port and causes the glass flake particles dispersed therein to be layered within the mold with their planar surfaces substantially parallel to the planar surfaces of the panel before gelation of the constituents, allowing said polyol isocyanate mixture to chemically react in the mold such that a hardened polymeric urethane panel is formed wherein said glass flakes are incorporated in their layered and surface parallel orientations, whereby the hardened urethane panel has a substantially wave free surface as molded and a substantially reduced coefficient of thermal expansion in all directions in the plane of the panel as compared to a like unfilled panel molded of like urethane constituents in like manner.

Claim 11

A method of molding an internally reinforced polyurethane panel comprising dispersing up to about 40 weight percent glass flake particles into one or both of the liquid polyol and isocyanate precursor constituents, impingement mixing said polyol and isocyanate constituents at a pressure of at least about 2000 pounds per square inch and filling a mold for said panel with said mixed constituents and causing them to gel to captivate said glass flake particles in layered and surface parallel orientations with respect to the plane of the panel within about two seconds from the time the constituents are first impingement mixed.

Claim 12

A method of molding an internally reinforced polyurethane panel comprising dispersing up to about 40 weight percent glass flake particles into one or both of the liquid polyol and isocyanate precursor constituents, impingement mixing said polyol and isocyanate constituents at a pressure of at least about 2000 pounds per square inch and filling a mold for said panel with said mixed constituents and causing them to gel to captivate said glass flake particles in layered and surface parallel orientations with respect to the plane of the panel within about two seconds from the time the constituents are first impingement mixed.