Method of making molding compounds and products produced thereby
AssigneeOwens-Corning Fiberglas Corporation
InventorsWalter D. Cottrell, Jr., Ernest E. Lawson
Life of this patent
Estimating the term…
Abstract
A method of making molding compounds, and particularly sheet molding compounds, wherein the reactive monomers are mixed directly with high density inorganic fillers and other ingredients of a molding compound. The monomers are converted to a resin insitu that is in or approaching the B-stage, so that the material is handleable as a solid and is moldable. Because of the amount, type, and thermal conductivity of the fillers, the resinification can be done quickly in a continuous process, by reason of the fact that the monomers are spread over a large surface area of inert fillers to provide good heat transfer, and exceedingly good process control.
Claims26
A new and improved method of producing molding compounds comprising:
- mixing an aldehyde and a hydrogen donor for producing alkanol groups therewith with a major proportion of a water wettable inorganic filler and catalyst for the reaction, the materials being present in proportions capable of producing the infusible thermoset condition, controlling the amount of water present to maintain the consistency of a paste, causing a polymerization reaction to be initiated in the paste between the aldehyde and hydrogen donor, kneading the paste at a controlled rate to control the reaction of the aldehyde and hydrogen donor in the paste, and cooling the paste to stop the polymerization reaction while the materials are still a paste.
A new and improved method of making sheet molding compound comprising:
- mixing polymer forming monomers with an inorganic filler and catalyst for the polymerization reaction, the materials being present in proportions capable of producing the infusible thermoset condition, converting the mix into the consistency of a paste and initiating a polymerization reaction, kneading the paste at a controlled rate to control the rate of polymerization, cooling the paste to arrest the reaction short of a thermoset condition, forming a sheet molding compound of the paste with glass fibers, and drying the sheet molding compound to convert the material into a handleable state.
A new and improved method of making sheet molding compound comprising:
- mixing a water solvatable aldehyde and a water solvatable hydrogen donor for producing alkanol groups therewith with a water wettable inorganic filler and catalyst for the reaction, the materials being present in proportions capable of producing the infusible thermoset condition, converting the mix into the consistency of a paste and initiating a polymerization reaction, kneading the paste at a controlled rate to control the rate of polymerization, cooling the paste to arrest the reaction short of a thermoset condition, forming a sheet molding compound by mixing with water wettable mineral fibers, and drying the sheet molding compound to convert the material into a handleable state.
A new and improved method of producing molding compounds comprising:
- mixing a solid aldehyde and a solid hydrogen donor for producing alkanol groups therewith with solid inorganic fillers containing catalyst for the reaction, spreading the mixture of solids onto a moving belt along with fibrous reinforcement therefor partially reacting the aldehyde and hydrogen donor insitu around the filler and reinforcement into a filled prepolymer, and converting the filled prepolymer into a handleable sheet molding compound.
A new and improved method of making sheet molding compound comprising:
- spreading a sticky aldehyde condensate prepolymer, filler and fiber reinforcement onto an impervious surface, covering the spread materials with another impervious surface and causing the fibers reinforcement to be embedded in the prepolymer and filler, reacting the prepolymer around the reinforcement, cooling the spread materials to stop the reaction at a sufficiently nonsticky state so that said other impervious surface can be removed, removing said other impervious surface, and heating the materials to react the prepolymer to a state wherein the materials are in a moldable, handleable state.
A new and improved method of producing molding compounds comprising:
- preparing a blend of dry solids that comprise inorganic water wettable fillers, a solid aldehyde and a solid hydrogen donor for the aldehyde, coverting the solids to a paste with water, initiating a reaction of the aldehyde and the hydrogen donor within the paste, kneading the paste to control the reaction, and cooling the paste to stop the reaction at an intermediate state of resinification wherein the paste has a viscosity below 50,000 poise.
A new and improved method of producing molding compounds comprising:
- preparing a blend of solids that comprise fillers and at least one of two resin forming monomers, feeding the blend of solids and remaining monomers to a continuous mixer and heat exchanger, converting any solid monomer present to a fluid state, reacting the now liquid monomers insitu on the surface of the fillers, cooling the blend to stop the reaction at an intermediate state of resinification, spreading the blend onto an impervious moving surface along with a fiber reinforcement, covering the spread material and fiber reinforcement with another impervious surface, heating the material between said impervious surfaces to further react the materials around the reinforcement, cooling the materials to a sufficiently nonsticky state that it can be separated from said other impervious surface, removing said other impervious surface, and finish reacting said materials to a nonsticky and handleable state.
Dependencies are inferred from the claim text.