The Dow Chemical Company

Michele R Lock

Kurt C Frisch, Jr

James G Galloway

Edward R Falardeau

Gregory J Stuk

Medardo Monzon

A paper product, especially light weight papers, is prepared with a structured latex particle having opacity and reinforcing characteristics comprising a core region having a light scattering characteristic and T.sub.g of about 80 degrees C or higher and a shell region of about 25 degrees C or lower. The structured latex particle provides opacity to the paper without adversely affecting its mechanical strength.

Structured latex particles having reinforcing and opacity characteristics

A solid catalyst composition comprising a silica or silica-treated compound and a tin catalyst compound bonded to the surface of the silica compound which is not deactivated in the presence of silica or silica-treated compounds. A process for preparing the solid catalyst by contacting a silica compound containing reactive hydroxyl groups with a tin catalyst compound at a temperature range from about 130.degree. to 165.degree. C. under dynamic conditions whereby the tin catalyst compound bonds to the silica compound. Generally, after the reaction, at least a portion of the hydroxyl groups present on the silica compound are absent and, more preferably, substantially all the isolated hydroxyl groups are absent. A urethane composition containing the solid catalyst is also provided wherein the solid catalyst is not deactivated by the addition of silica or silica-treated compounds.

Silica bonded tin urethane catalysts

A surface is coated with a mixture of (i) an aliphatic, aromatic polyisocyanate such as 1,3-bis-(1-isocyanato-1-methylethyl)benzene, and (ii) a polyactive hydrogen compound such as a poly(2-hydroxyethylacrylate), and the mixture is cured under conditions such that an adherent, solid coating is formed on the surface. The coatings of the invention have surprising gloss and lack of yellowness after exposure to ultra-violet light.

Urethane coatings from aliphatic aromatic diisocyanates

An addition polymerizable adhesive is prepared by using the reaction product of (1) an isocyanate compound (such as 2-isocyanatoethyl methacrylate) and (2) an active hydrogen compound (such as a poly(ethylene glycol)) wherein the reaction between (1) and (2) is catalyzed with a tin (II) organoester (such as stannous octoate). The adhesives of the invention have surprisingly long shelf lives compared to similar adhesives made with other catalysts.

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Midland, MI, United States of America

Michele R Lock