Aristech Chemical Corporation

Aristech Acrylics LLC

Ettore Minghetti

John E Eitel

Carol A Wetter

Harry W Cheesman

The present invention is drawn to a composition and thermoformable sheets and articles made therefrom. In the present invention, ranges of chain-transfer agents, thixotropic agents, and mineral filler content are balanced to minimize migration or maldistribution of coloring matter and mineral filler during curing of methyl methacrylate in a syrup and also during subsequent heating and deformation in thermoforming, to achieve constancy of impact resistance and improve stability of patterns even in deformed portions of formed sheets.

Method of making a thermoformable article having uniform distribution of coloring and mineral filler before and after thermoforming

The present invention relates to mold inserts suitable for use with thermoformable sheets made of poly(methyl) methacrylate and other thermoplastic sheet material. The inserts become an integrated part of the thermoformed product, and are characterized by having at least one removable portion or plug. The plug(s) are removed during the thermoforming process, and allow the thermoformed sheet material to shrink without creating undesirable levels of stress in the sheet material. This prevents cracking or other failure of the sheet material.

Thermoformed articles having an improved insert therein

Acrylic sheet having uniform distribution of color and mineral filler before and after thermoforming

A method of making acrylic products having a relatively even distribution of visible accent particles dispersed therein. The acrylic products are made from a composition comprising an acrylic matrix comprising a monomer rich syrup and having pre-formed particles added thereto. The pre-formed particles are evenly dispersed in the matrix by virtue of their geometry, similarity in composition or specific gravity to that of the matrix. When added with the accent particles, the pre-formed particles serve the function of restricting the movement of, and thereby suspending the accent particles in an even dispersion within the matrix. The results is an even distribution of the accent particles in the finished product.

Suspending accent particles in an acrylic matrix

Acrylic sheet having uniform distribution of coloring and mineral filler

Ranges of chain-transfer agents, thixotropic agents, and alumina trihydrate content are balanced to minimize migration or maldistribution of coloring matter and alumina trihydrate during curing of methyl methacrylate in a syrup including polymethylmethacrylate and also during subsequent heating and deformation in thermoforming, to achieve constancy of impact resistance and improve stability of patterns even in deformed portions of formed sheets.

A composition suitable for making thermoformable sheets and the like. The composition comprises a crosslinked poly (methyl methacrylate) typically having uncrosslinked poly (methyl methacrylate) dispersed therein. The composition a comprises 0.5 to about 1.0 pph of at least one crosslinking agent x, and up to about 0.58x-0.28 pph of a at least one chain terminator. The composition also comprises about 0.1 to 8 pph poly (methyl methacrylate) compatible plasticizer, and has about 20 to 60 wt % solid particle dispersed therein.

Thermoformable acrylic sheet having uniform distribution of color and

A monomer-rich acrylic syrup is cast including about 10% to about 20% ground acrylic particles. During curing, the particles absorb over half their weight in monomer, and a cured sheet is formed in which the matrix monomer and uncrosslinked polymer form a phase which extends through the particles, while the particles appear to be fused together. Including a crosslinker in the syrup further insures the interpenetration of the matrix phase into the swollen particles. A textured surface is formed, which is useful as an anti-slip surface in bathtubs and shower stalls, after thermoforming.

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Boone County, KY, United States of America

Ettore Minghetti