US4102833A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cold impact resistant urethane foam
Assignee: Davidson Rubber Co Inc
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Filing: 1977-03-16
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Granted: 1978-07-25
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Expires: 1997-03-16
Abstract
Abstract A quasi-prepolymer-type urethane foam for a reaction injection molding (RIM) system comprises, for the polyol side, a blend of a long-chain polyol with a short-chain diol and/or triol and an organometallic catalyst and, for the prepolymer side, a unique high--27 to 31% --free NCO quasi-prepolymer made by reacting an essentially pure MDI with a selected low molecular weight (240 to 1500) polyol having a functionality of about 2.7 to 3.3. The selected low molecular weight polyol is specifically a polyether polyol (i.e. a polyoxpropylene and/or ethylene polyol) initiated with TMP, hexanetriol, glycerine or other suitable polyol. The quasi-prepolymer, while having the expected high reactivity, surprisingly gives good rapid cures in less than 2 minutes. The resulting urethane foam is characterized by its excellent low temperature properties, especially -20% F cold flexibility and -20% F dart impact. The quasi-prepolymer storage stability can be greatly improved by the inclusion of a small amount of a liquid MDI.
Inventors
- 👤 Wayne C. Salisbury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:36
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/72; C08G18/80; C08G18/8003; C08G18/8006; C08G18/8009; C08G18/8012; C08G18/8019; C08G18/28; C08G18/65; C08G18/66; C08G18/6666; C08G18/667; C08G18/6681; C08G18/6685; C08G2110/00; C08G2110/0033; C08G2110/0041; C08G2110/0066; C08G2120/00; Y; Y10; Y10S; Y10S264/00; Y10S264/83
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
119 words
A urethane foam quasi-prepolymer having a free isocyanate content in the range of 27 to 31% and consisting essentially of the reaction product of (parts by weight): ______________________________________
Pure MDI 80 to 90
LMW Polyol 3 to 20
______________________________________ wherein said pure MDI is 99%+ methylene bis (4-phenyl isocyanate) and said LMW Polyol is selected from the group consisting of a polyether polyol and polyether polyol blends and has a molecular weight in the range of 240 to 1500 and a functionality in the range of 2.6 to 3.3 on the average for all polyol present, said quasi-prepolymer being made by blending together said pure MDI and LMW polyol and allowing the blend to react at an elevated temperature.
Claim 2
Dependent Claim
119 words
A urethane foam quasi-prepolymer having a free isocyanate content in the range of 27 to 31% and consisting essentially of the reaction product of (parts by weight): ______________________________________
Pure MDI 80 to 90
LMW Polyol 3 to 20
______________________________________ wherein said pure MDI is 99%+ methylene bis (4-phenyl isocyanate) and said LMW Polyol is selected from the group consisting of a polyether polyol and polyether polyol blends and has a molecular weight in the range of 240 to 1500 and a functionality in the range of 2.6 to 3.3 on the average for all polyol present, said quasi-prepolymer being made by blending together said pure MDI and LMW polyol and allowing the blend to react at an elevated temperature.
Claim 3
Dependent Claim
48 words
The quasi-prepolymer of claim 1 rendered storage stable when held at a temperature in the range of 90° to 120° F by the blending and reacting therein at any stage of the reaction of in the range of 1 to 20 percent by weight of a liquid MDI.
Claim 4
Dependent Claim
31 words
The quasi-prepolymer of claim 1 wherein said LMW polyol is selected from the group consisting of polyoxyethylene and polyoxypropylene polyols and said functionality is in the range of 2.7 to 3.1.
Claim 5
Dependent Claim
105 words
A urethane foam having good low temperature properties made by reacting at an Isocyanate Index in the range of 98 to 108 of the quasi-prepolymer of claim 1 with a polyol blend of the following composition: ______________________________________
Parts by Weight
______________________________________
Long chain polyol 50 to 100
Alkane polyol 0 to 25
Alkylene amine catalyst 0.01 to 3.0
Organometallic catalyst 0.01 to 0.05
______________________________________ wherein said long chain polyol has a molecular weight in the range of 3000 to 6000 and a functionality in the range of 2 to 3 and said alkane polyol has a molecular weight in the range of 62 to 250.
Claim 6
Dependent Claim
28 words
The foam of claim 4 wherein in the range of 0.6 to 0.7 parts of said quasi-prepolymer are reacted with each part by weight of said polyol blend.
Claim 7
Dependent Claim
42 words
A urethane foam article made with the urethane foam of claim 4 when made in a RIM system to a molded density in the range of 55 to 65 pounds per cubic foot with a demolding time of less than 2 minutes.
Claim 8
Dependent Claim
186 words
A quasi-prepolymer urethane foam consisting of on the one hand a polyol blend and on the other a quasi-prepolymer, the two being admixed and reacted to form a foam: (a) said polyol blend comprising: ______________________________________
Parts by Weight
______________________________________
Long chain polyol 50 to 100
Alkane polyol 0 to 25
Alkylene amine catalyst 0.01 to 3.0
Organometallic catalyst 0.01 to 0.05
______________________________________ wherein said long chain polyol has a molecular weight in the range of 3000 to 6000 and a functionality in the range of 2 to 3 and said alkane polyol has a molecular weight in the range of 62 to 250. (b) said quasi-prepolymer having a free isocyanate content in the range of 27 to 31% and comprising the reaction product of: ______________________________________
Parts by Weight
______________________________________
Pure MDI 80 to 90
LMW Polyol 3 to 20
______________________________________ wherein said LMW Polyol is selected from the group consisting of a polyether polyol and polyether polyol blends having a molecular weight in the range of 240 to 1500 and a functionality in the range of 2.6 to 3.3 on the average for all polyol present.
Claim 9
Dependent Claim
186 words
A quasi-prepolymer urethane foam consisting of on the one hand a polyol blend and on the other a quasi-prepolymer, the two being admixed and reacted to form a foam: (a) said polyol blend comprising: ______________________________________
Parts by Weight
______________________________________
Long chain polyol 50 to 100
Alkane polyol 0 to 25
Alkylene amine catalyst 0.01 to 3.0
Organometallic catalyst 0.01 to 0.05
______________________________________ wherein said long chain polyol has a molecular weight in the range of 3000 to 6000 and a functionality in the range of 2 to 3 and said alkane polyol has a molecular weight in the range of 62 to 250. (b) said quasi-prepolymer having a free isocyanate content in the range of 27 to 31% and comprising the reaction product of: ______________________________________
Parts by Weight
______________________________________
Pure MDI 80 to 90
LMW Polyol 3 to 20
______________________________________ wherein said LMW Polyol is selected from the group consisting of a polyether polyol and polyether polyol blends having a molecular weight in the range of 240 to 1500 and a functionality in the range of 2.6 to 3.3 on the average for all polyol present.
Claim 10
Dependent Claim
74 words
A urethane foam made by bringing together the polyol blend and quasi-prepolymer of claim 7 in a RIM machine at an Isocyanate Index in the range of 98 to 108, injecting the resulting mixture into a closed cavity mold in an amount sized to give a foam density in the range of 45 to 72 pounds per cubic foot, allowing said mixture to react and demolding the foamed product in less than 2 minutes.
References Cited (Backward Citations)
US3728288A
Cited
US3892691A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-24 | 1982-01-23 | 1982-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-24 | 1986-01-23 | 1986-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-24 | 1990-01-23 | 1990-07-25 | $7700.00 | Window Closed / Lapsed |