US4433120A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid phenolic resin composition and method for waferboard manufacture
Assignee: Hexion Canada Inc
•
Filing: 1981-09-30
•
Granted: 1984-02-21
•
Expires: 2001-09-30
Abstract
Abstract A pre-cure resistant liquid phenol-formaldehyde resin binder composition having low viscosity and low surface tension for efficient spray application as fine droplets in waferboard manufacture comprising a highly condensed and cross-linkable phenol-formaldehyde resin of relatively high average molecular weight and a non-resinous methylolated phenol condensate having an average molecular weight of 200-300.
Inventors
- 👤 Shui-Tung Chiu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:32
CPC Classifications
C; C08; C08L; C08L61/00; C08L61/04; C08L61/06; C08G; C08G8/00; C08G8/04
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
190 words
A method of preparing a pre-cure resistant liquid phenolic resin binder composition having a viscosity and surface tension which is sufficiently low to allow spray application as fine droplets to waferboard comprising the steps of: (a) reacting phenol and formaldehyde in a formaldehyde to phenol molar ratio of 1:1 to 3:1 in a first stage in the presence of an alkaline catalyst at a temperature which is allowed to rise to between 80° C. and reflux to produce a highly-condensed and crosslinkable phenol-formaldehyde resin having an average molecular weight in the range of about 2000-6000 and a viscosity of 100-450 cps at 25° C. (b) reducing the temperature of the resulting resin to 60°-70° C., (c) adding a second portion of phenol and formaldehyde in a phenol to formaldehyde mol ratio of 1.5:1 to 3:1 and alkaline catalyst to the resin and cooking at 45°-70° C. until the formaldehyde is reacted to a free formaldehyde content of 0-4% to produce a non-resinous phenol-formaldehyde condensate comprising methylated phenols having an average molecular weight of about 200-300; and (d) cooling the resulting liquid phenolic resin composition to a temperature below room temperature.
Claim 2
Independent Claim
190 words
A method of preparing a pre-cure resistant liquid phenolic resin binder composition having a viscosity and surface tension which is sufficiently low to allow spray application as fine droplets to waferboard comprising the steps of: (a) reacting phenol and formaldehyde in a formaldehyde to phenol molar ratio of 1:1 to 3:1 in a first stage in the presence of an alkaline catalyst at a temperature which is allowed to rise to between 80° C. and reflux to produce a highly-condensed and crosslinkable phenol-formaldehyde resin having an average molecular weight in the range of about 2000-6000 and a viscosity of 100-450 cps at 25° C. (b) reducing the temperature of the resulting resin to 60°-70° C., (c) adding a second portion of phenol and formaldehyde in a phenol to formaldehyde mol ratio of 1.5:1 to 3:1 and alkaline catalyst to the resin and cooking at 45°-70° C. until the formaldehyde is reacted to a free formaldehyde content of 0-4% to produce a non-resinous phenol-formaldehyde condensate comprising methylated phenols having an average molecular weight of about 200-300; and (d) cooling the resulting liquid phenolic resin composition to a temperature below room temperature.
Claim 3
Dependent Claim
52 words
The method of claim 1 wherein the resulting liquid resin binder composition comprises 20-80% by weight of the highly condensed, high molecular weight resin and 80-20% by weight of the non-resinous condensate and the resulting overall formaldehyde to phenol molar ratio in the composition is within the range of 1.5:1 to 2.6:1.
Claim 4
Dependent Claim
24 words
The method of claim 2 wherein the non-resinous phenol-formaldehyde condensates consist essentially of mono, di, and tri-methylol phenols and methylolated di and tri-nuclear phenols.
Claim 5
Dependent Claim
24 words
The method claim 3 wherein the alkaline catalyst is sodium hydroxide and is present in a molar ratio to phenol of 0.1:1 to 0.6:1.
Claim 6
Dependent Claim
51 words
The method of claim 4 wherein the molar ratio of formaldehyde to phenol are in the range of 2.0:1 to 2.5:1 in the highly condensed resin of step (a); 1.8:1 to 2.3:1 in the non-resinous condensate of step (c) and 1.7:1 to 2.4:1 in the resulting liquid phenolic resin binder composition.
Claim 7
Dependent Claim
47 words
The method of claim 1 further including the step of adding a formaldehyde scavenger compound selected from the group consisting of ammonium hydroxide, resorcinol, 3,5-xylenol, 3-cresol, urea and sulfites to the resin composition at the end of the resin cooking in step (c) to reduce residual formaldehyde.
Claim 8
Dependent Claim
31 words
The method of claim 3 wherein the resin composition comprises 40-60% by weight of the highly condensed and cross-linkable phenol formaldehyde resin and 60-40% by weight of the non-resinous phenol-formaldehyde condensates.
Claim 9
Dependent Claim
18 words
The method of claim 7 wherein the liquid resin composition comprises 35-70% resin solids in an aqueous medium.
Claim 10
Dependent Claim
58 words
A liquid phenolic resin binder composition having a viscosity and surface tension which is sufficiently low to allow spray atomization as a fine droplet; a free formaldehyde content of 0-4% by weight and which is characterized by being pre-cure resistant when applied to waferboard under conventional waferboard manufacturing conditions which is prepared by the method of claim 1.
Claim 11
Dependent Claim
26 words
The liquid phenolic resin of claim 9 wherein the non-resinous phenol-formaldehyde condensate consists essentially of mono, di and tri-methylol phenols and methylolated di and tri-nuclear phenols.
Claim 12
Dependent Claim
43 words
The composition of claim 9 wherein the molar ratio of formaldehyde to phenol are in the range of 1:1 to 3:1 for highly condensed resin; 1.5:1 to 3:1 for the non-resinous condensate and 1.5:1 to 2.6:1 for the resulting overall resin binder composition.
Claim 13
Dependent Claim
44 words
The composition of claim 11 wherein the molar ratio of formaldehyde to phenol are in the range of 2.0:1 to 2.5:1 for the highly condensed resin; 1.8:1 to 2.3:1 for the non-resinous condensate, and 1.7:1 to 2.4:1 for the resulting overall resin binder composition.
Claim 14
Dependent Claim
21 words
The composition of claim 9 wherein the liquid resin composition comprises 35-70% by weight of resin solids in an aqueous solution.
Claim 15
Dependent Claim
21 words
The composition of claim 13 wherein the resin solids are present in an amount of 50-60% by weight of the composition.
Claim 16
Dependent Claim
28 words
The composition of claim 9 wherein the liquid phenolic resin composition comprises 40-60% by weight of the highly condensed resin and 60-40% by weight of the non-resin condensate.
References Cited (Backward Citations)
US2631097A
Cited
US2620288A
Cited
US3180784A
Cited
US3267188A
Cited
US3342776A
Cited
US3591535A
Cited
US3927104A
Cited
US3839251A
Cited
US3927140A
Cited
US4098770A
Cited
US4269949A
Cited
US4345054A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-20 | 1987-08-22 | 1988-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-20 | 1991-08-22 | 1992-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-20 | 1995-08-22 | 1996-02-21 | $7700.00 | Window Closed / Lapsed |