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AssigneeKoppers Company, Inc.
InventorsJohn D. Carlson, Edward W. Kifer, Vincent J. Wojtyna, James P. Colton
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The present invention is directed to aqueous phenol formaldehyde resoles that have particular application in manufacturing phenolic foam insulation. The resoles are essentially phenol formaldehyde condensation polymers having molar ratios of formaldehyde to phenol of from about 1.7:1 to 2.3:1, preferably from 1.75:1 to 2.25:1 and most preferably about 2:1. The resoles have a weight average molecular weight greater than 800 and preferably from 950-1500. The resoles also have a number average molecular weight greater than 350 and preferably from about 400 to about 600 and a dispersivity greater than about 1.7, preferably from 1.8 to 2.6. Phenol formaldehyde resoles having these characteristics are processable into phenolic foams having a low k value and having other physical characteristics which make the phenolic foam especially useful as an insulation material. The present invention is also directed to foamable phenolic resole compositions prepared from the phenolic resoles and phenolic foams prepared from the compositions.
An improved process for preparing closed cell phenolic foam having entrapped fluorocarbon blowing agent comprising preparing a foamable phenolic resole composition comprising aqueous phenol formaldehyde resole, surfactant, fluorocarbon blowing agent and acid catalyst, and foaming and curing said composition in a substantially closed mold wherein the improvement comprises a phenol formaldehyde resole having a molar ratio of formaldehyde to phenol of from about 1.7:1 to about 2.3:1, a weight average molecular weight greater than about 800, a number average molecular weight greater than about 350, a dispersivity greater than about 1.7 and wherein the content of free formaldehyde and free phenol are each less than 7 percent by weight.
An improved process for preparing closed cell phenolic foam having entrapped fluorocarbon blowing agent comprising preparing a foamable phenolic resole composition comprising aqueous phenol formaldehyde resole, surfactant, fluorocarbon blowing agent and acid catalyst, and foaming and curing said composition in a substantially closed mold wherein the improvement comprises a phenol formaldehyde resole having a molar ratio of formaldehyde to phenol of from about 1.7:1 to 2.3:1, a weight average molecular weight between about 950 and 1500, a number average molecular weight between about 400 and 600, a dispersivity between about 1.8 and 2.6 and wherein the content of free formaldehyde and free phenol are each less than 7 percent by weight.
An improved process for preparing closed cell phenolic foam having entrapped fluorocarbon blowing agent comprising preparing a foamable phenolic resole composition comprising aqueous phenol formaldehyde resole, surfactant, fluorocarbon blowing agent and acid catalyst, and foaming and curing said composition in a substantially closed mold wherein the improvement comprises a phenol formaldehyde resole having a molar ratio of formaldehyde to phenol of from about 1.75:1 to about 2.25:1, a weight average molecular weight greater than about 800, a number average molecular weight greater than about 350, a dispersivity greater than about 1.7 and wherein the content of free formaldehyde and free phenol are each less than 7 percent by weight.
An improved process for preparing closed cell phenolic foam having entrapped fluorocarbon blowing agent comprising preparing a foamable phenolic resole composition comprising aqueous phenol formaldehyde resole, surfactant, fluorocarbon blowing agent and acid catalyst, and foaming and curing said composition in a substantially closed mold wherein the improvement comprises a phenol formaldehyde resole having a molar ratio of formaldehyde to phenol of from about 1.75:1 to 2.25:1, a weight average molecular weight between about 950 and 1500, a number average molecular weight between about 400 and 600, a dispersitivity between about 1.8 and 2.6 and wherein the content of free formaldehyde and free phenol are each less than 7 percent by weight.
An improved process for preparing closed cell phenolic foam having entrapped fluorocarbon blowing agent comprising preparing a foamable phenolic resole composition comprising aqueous phenol formaldehyde resole, surfactant, fluorocarbon blowing agent and acid catalyst, and foaming and curing said composition in a substantially closed mold wherein the improvement comprises a phenol formaldehyde resole having a molar ratio of formaldehyde to phenol of about 2:1, a weight average molecular weight greater than about 800, a number average molecular weight greater than about 350, a dispersivity greater than about 1.7 and wherein the content of free formaldehyde and free phenol are each less than 7 percent by weight.
An improved process for preparing closed cell phenolic foam having entrapped fluorocarbon blowing agent comprising preparing a foamable phenolic resole composition comprising aqueous phenol formaldehyde resole, surfactant, fluorocarbon blowing agent and acid catalyst, and foaming and curing said composition in a substantially closed mold wherein the improvement comprises a phenol formaldehyde resole having a molar ratio of formaldehyde to phenol of about 2:1, a weight average molecular weight between about 950 and 1500, a number average molecular weight between about 400 and 600, a dispersivity between about 1.8 and 2.6 and wherein the content of free formaldehyde and free phenol are each less than 7 percent by weight.
An improved foamable phenolic resole composition for preparing closed cell phenolic foam comprising an aqueous phenol formaldehyde resole, surfactant, blowing agent and acid catalyst wherein the improvement comprises a phenol formaldehyde resole having a molar ratio of formaldehyde to phenol of from about 1.7:1 to about 2.3:1, a weight average molecular weight greater than about 800, a number average molecular weight greater than about 350, a dispersivity greater than about 1.7 and wherein the content of free formaldehyde and free phenol are each less than 7 percent by weight.
An improved foamable phenolic resole composition for preparing closed cell phenolic foam comprising an aqueous phenol formaldehyde resole, surfactant, blowing agent and acid catalyst wherein the improvement comprises a phenol formaldehyde resole having a molar ratio of formaldehyde to phenol of from about 1.7:1 to 2.3:1, a weight average molecular weight between about 950 and 1500, a number average molecular weight between about 400 and 600, a dispersivity between about 1.8 and 2.6 and wherein the content of free formaldehyde and free phenol are each less than 7 percent by weight.
An improved foamable phenolic resole composition for preparing closed cell phenolic foam comprising an aqueous phenol formaldehyde resole, surfactant, blowing agent and acid catalyst wherein the improvement comprises a phenol formaldehyde resole having a molar ratio of formaldehyde to phenol of from about 1.75:1 to 2.25:1, a weight average molecular weight greater than about 800, a number average molecular weight greater than about 350, a dispersivity greater than about 1.7 and wherein the content of free formaldehyde and free phenol are each less than 7 percent by weight.
An improved foamable phenolic resole composition for preparing closed cell phenolic foam comprising an aqueous phenol formaldehyde resole, surfactant, blowing agent and acid catalyst wherein the improvement comprises a phenol formaldehyde resole having a molar ratio of formaldehyde to phenol of from about 1.75:1 to 2.25:1, a weight average molecular weight between 950 and 1500, a number average molecular weight between about 400 and 600, a dispersivity between about 1.8 and 2.6 and wherein the content of free formaldehyde and free phenol are each less than 7 percent by weight.
An improved foamable phenolic resole composition for preparing closed cell phenolic foam comprising an aqueous phenol formaldehyde resole, surfactant, blowing agent and acid catalyst wherein the improvement comprises a phenol formaldehyde resole having a molar ratio of formaldehyde to phenol of about 2:1, a weight average molecular weight greater than about 800, a number average molecular weight greater than about 350, a dispersivity greater than about 1.7 and wherein the content of free formaldehyde and free phenol are each less than 7 percent by weight.
An improved foamable phenolic resole composition for preparing closed cell phenolic foam comprising an aqueous phenol formaldehyde resole, surfactant, blowing agent and acid catalyst wherein the improvement comprises a phenol formaldehyde resole having a molar ratio of formaldehyde to phenol of about 2:1, a weight average molecular weight between about 950 and 1500, a number average molecular weight between about 400 and 600, a dispersivity between about 1.8 and 2.6 and wherein the content of free formaldehyde and free phenol are each less than 7 percent by weight.
Dependencies are inferred from the claim text.
From the US filing history. Foreign family members aren’t listed.
Halogen containing compounds: containing carbon and halogen atoms only
Of formaldehyde, e.g. of formaldehyde formed in situ: with phenol
Condensation polymers of aldehydes or ketones with phenols only: of aldehydes with phenols
Working-up
Term ended 3 Sep 2002 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
1. Field of the Invention
The present invention is directed to particular aqueous phenol formaldehyde resoles that are produced by the base catalyzed condensation of phenol and formaldehyde. These phenolic resoles are especially useful in preparing phenolic foams having both a low k value and excellent fire properties, compressive strength, density, friability and other properties necessary for insulation board. The invention is also directed to foamable phenolic resole compositions prepared using the aqueous phenolic resoles and phenolic foams made from the compositions.
2. Prior Art
Like numerals refer to like parts in the following drawings.
FIGS. 1A and 1B illustrate diagrammatically in partial cross sections substantially closed molds used in making phenolic foam in the laboratory.
FIG. 2 illustrates diagrammatically a side view of cross section of a double belt type apparatus for continuously making phenolic foam.
As mentioned above, the use of phenolic foams for thermal insulation applications, particularly for roofs, walls and pipes, is highly desirable because of the excellent fire properties that are inherent in phenolic foams. However, phenolic foams heretofore known suffer from generally unacceptable initial k factors and their inability to retain a low k factor over time. The thermal insulating ability of a foamed material generally may be evaluated by the thermal conductivity or k factor. The thermal conductivity or k factor of a particular insulation material is measured according to ASTM Method C-518 Revised and is typically expressed dimensionally as BTU per inch per hour per square foot per .degree.F. The lower the k factor, the better is the insulating quality of the material. Additionally, the longer the foam can retain a low k factor, the better is the insulating efficiency of the material.
A low k factor is understood to mean a k factor substantially below about 0.22, which is approximately the k factor of air. An initially low k factor is understood to mean a k factor of substantially below 0.22 when measured after the foam that is initially produced comes to an equilibrium water content, generally within about five days. It has been found that phenolic foam can be prepared with the phenolic resoles of the present invention that have k factors that decrease during the first several days as the water content of the phenolic foam comes to equilibrium with the environment. Thereafter, the k factor remains substantially constant over time. Phenolic foams can be prepared with the resoles of the present invention that have initial k factors measured according to the ASTM method of less than 0.15 and generally in the range of 0.10 to 0.13. Some of the foams prepared with the preferred phenolic resoles have had k factors less than 0.10 when measured at very low water contents. Phenolic foam can be prepared which retain these low k factors over time.
Phenolic foams prepared from the phenolic resoles of the invention generally have overall densities (i.e., including foam skin) ranging from about 1.5 to about 5.0 pounds per cubic foot (about 24 to about 80 kg/cu. meter) and preferably ranging from about 2.0 to about 4.0 pounds per cubic foot (about 32 to about 64 kg/cu. meter) and core densities (i.e., without foam skin) ranging from about 1.5 to about 4.5 pounds per cubic foot (about 24 to about 72 kg/cu. meter) and preferably ranging from about 2.0 to about 3.5 pounds per cubic foot (about 32 to about 56 kg/cu. meter). Phenolic foams can be prepared that are substantially closed-cell foams (i.e., substantially free of ruptured cell walls) generally containing at least 90 to 95 percent closed cells and typically greater than 95 percent closed cells as measured, for example, by an air pycnometer according to test ASTM D-2865-70 (1976).
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