GB1590554A - Creation of Inventions and Patents with Artificial Intelligence

GB1590554A – Cold impact resistant urethane foam
– Google Patents

GB1590554A – Cold impact resistant urethane foam
– Google Patents
Cold impact resistant urethane foam

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Publication number
GB1590554A

GB1590554A
GB10005/78A
GB1000578A
GB1590554A
GB 1590554 A
GB1590554 A
GB 1590554A
GB 10005/78 A
GB10005/78 A
GB 10005/78A
GB 1000578 A
GB1000578 A
GB 1000578A
GB 1590554 A
GB1590554 A
GB 1590554A
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GB
United Kingdom
Prior art keywords
polyol
range
prepolymer
weight
quasi
Prior art date
1977-03-16
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Expired

Application number
GB10005/78A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

McCord Corp

Original Assignee
McCord Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1977-03-16
Filing date
1978-03-14
Publication date
1981-06-03

1977-03-16
Priority claimed from US05/778,001
external-priority
patent/US4102833A/en

1978-03-14
Application filed by McCord Corp
filed
Critical
McCord Corp

1981-06-03
Publication of GB1590554A
publication
Critical
patent/GB1590554A/en

Status
Expired
legal-status
Critical
Current

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Classifications

C—CHEMISTRY; METALLURGY

C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON

C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

C08G18/00—Polymeric products of isocyanates or isothiocyanates

C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen

C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used

C08G18/72—Polyisocyanates or polyisothiocyanates

C08G18/80—Masked polyisocyanates

C08G18/8003—Masked polyisocyanates masked with compounds having at least two groups containing active hydrogen

C08G18/8006—Masked polyisocyanates masked with compounds having at least two groups containing active hydrogen with compounds of C08G18/32

C08G18/8009—Masked polyisocyanates masked with compounds having at least two groups containing active hydrogen with compounds of C08G18/32 with compounds of C08G18/3203

C08G18/8035—Masked aromatic polyisocyanates not provided for in one single of the groups C08G18/8019 and C08G18/8029

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES

A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads

A61L15/16—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons

A61L15/22—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons containing macromolecular materials

A61L15/26—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives thereof

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads

A61L15/16—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons

A61L15/42—Use of materials characterised by their function or physical properties

A61L15/425—Porous materials, e.g. foams or sponges

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61L17/00—Materials for surgical sutures or for ligaturing blood vessels ; Materials for prostheses or catheters

A61L17/06—At least partially resorbable materials

A61L17/10—At least partially resorbable materials containing macromolecular materials

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61L27/00—Materials for grafts or prostheses or for coating grafts or prostheses

A61L27/14—Macromolecular materials

A61L27/18—Macromolecular materials obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61L9/00—Disinfection, sterilisation or deodorisation of air

A61L9/015—Disinfection, sterilisation or deodorisation of air using gaseous or vaporous substances, e.g. ozone

A61L9/04—Disinfection, sterilisation or deodorisation of air using gaseous or vaporous substances, e.g. ozone using substances evaporated in the air without heating

A61L9/042—Disinfection, sterilisation or deodorisation of air using gaseous or vaporous substances, e.g. ozone using substances evaporated in the air without heating with the help of a macromolecular compound as a carrier or diluent

C—CHEMISTRY; METALLURGY

C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON

C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

C08G18/00—Polymeric products of isocyanates or isothiocyanates

C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen

C08G18/08—Processes

C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step

C—CHEMISTRY; METALLURGY

C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON

C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

C08G18/00—Polymeric products of isocyanates or isothiocyanates

C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen

C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen

C08G18/40—High-molecular-weight compounds

C08G18/48—Polyethers

C—CHEMISTRY; METALLURGY

C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON

C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

C08G2110/00—Foam properties

C08G2110/0041—Foam properties having specified density

C08G2110/0066—≥ 150kg/m3

Description

(54) COLD IMPACT RESISTANT URETHANE FOAM
(71) We, McCORD CORPORATION, a corporation of the State of Michigan, United
States of America, of 2850 West Grand Boulevard, Detroit, Michigan 48202, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:
This invention pertains to the manufacture of urethane foam automobile trim components such as bumpers and fascia by reaction injection molding (RIM) of a particular quasi-prepolymer urethane foam composition. It is more particularly concerned with a quasi-prepolymer urethane foam composition that produces a foam product having excellent low temperature flexibility and impact properties.
According to the present invention there is provided a liquid urethane quasi-prepolymer having a free isocyanate content in the range of 27 to 31% by weight composed 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 a polyether polyol and has a molecular weight in the range of 240 to 1500 and a functionality in the range of 2.6 to 3.3, said quasi-prepolymer being made by blending together said pure MDI and LMW polyol and allowing the blend to react at an elevated temperature.
This urethane foam is characterized by the use of a unique prepolymer made with methylene bis (4-phenyl isocyanate), or MDI, and relatively low molecular weight polyols having a functionality of 2.6 to 3.3, especially 2.7 to 3.1. The quasi-prepolymer has an exceptionally high free isocyanate (FNCO) content–27 to 31% by weight.
The quasi-prepolymer when prepared is a liquid and is reasonably storage stable. This is in part because, while the prepolymer is largely prepared from essentially pure MDI, a small amount of a “liquid” or a modified MDI is added towards the end of the reaction to disrupt the symmetry of the final prepolymer. The so-called “liquid” MDI contains a small amount of materials such as trimmers and carbodiimides and these impurities inhibit crystallization.
The development of RIM systems such as ones using high pressure multi-stream high velocity impingement to effect essentially instantaneous mixing of urethane foam ingredients is a recent advance in the art. As used herein, RIM means a system wherein the theoretical time from initial mixing of any one portion of the urethane foam ingredients to injection in the mold cavity is less than 0.1 second.
Up to now quasi-prepolymer formulations with a FNCO of more than 26% have been difficult to cure at all, aside from the difficulty of making such a system meet the constraints of RIM. As one skilled in the art appreciates, while a prepolymer having a high FNCO is highly reactive, the cure of the foam produced therewith is quite slow and often poor. Even in the catalyzed system cure times with a high FNCO prepolymer can be as much as 30 minutes. The FNCO of pure MDI is 33.6% by weight and in the present invention the
FNCO of the prepolymer is 27 to 31% by weight which indicates that a considerable amount of the isocyanate groups of the MDI remain unreacted and that the prepolymer contains only a relatively small (but significant) amount of the prepolymer polyol (preferably triol or triol/diol blend) referred to as LMW polyol. 80 to 90 parts by weight of the MDI is admixed with 3 to 20 parts of the LMW polyol, and the mixture is allowed to exotherm at an elevated temperature with agitation and under an inert atmosphere. The temperature is kept preferably in the range of 1200 to 1700F with cooling if necessary.
One of the unique features of this invention is that the high FNCO, highly reactive prepolymer does not suffer from poor cures and cure times. Cure times are under 2 minutes, usually 1 minute or less. This balance of reactivity versus cure is secured by using just enough but a minimal amount of the LMW polyol. The effectiveness of the cure can readily be determined from this simple laboratory bending test: a 0.125″ thick sample plaque is rapidly folded back on itself immediately after demolding and any cracking and/or crazing is observed. The cure is considered to be satisfactory when no cracking or crazing appears.
The use of a triol as opposed to a diol in the prepolymer may at first blush seem questionable when one has gone to considerable expense to start with pure MDI to secure difunctionality. Pure MDI is some 2l/2 times as expensive as the higher functional polymeric
MDI. Crude MDI has a different molecular structure with up to three reactive sites on a molecule. But is it a finding of this invention that just enough triol can be used to increase functionality above 2 and to dramatically reduce the cure time without serious loss of the important physical properties in the final foam–tear strength and elongation. While there is or may be some slight decrease in the final physical properties of the urethane foam, this is more than offset by the dramatic reduction in the foam cure time required to develop these physical properties.
With the foam of this invention, one set of physical properties of particular concern is measured by the Ford Cold Flexibility Test (Ford reference No. ESB-M2P-105-A, Sec.
3.2.11) wherein a cold (-20″F) painted specimen is quickly bent 1800 around a l/2-inch mandrel. The paint used is specifically PPG Industries, Inc. (One Gateway Center,
Pittsburgh, Pennsylvania 15222) Durethane (Registered Trade Mark) D-100 that bonds well to urethane surfaces. In this test the paint film cracks and with many urethane foams these cracks in the paint film are propagated into the foam body, which is considered a failure. The present foam passes this test, i.e. cracks will not appear in the body of the foam.
The FNCO number sets or species the amount of triol that is present in the prepolymer.
This triol is referred to in the claims as “low molecular weight” (LMW) polyol which means a polyol having a molecular weight in the range of 240 to 1500, a functionality in the range of 2.6 to 3.3 and specifically made from a polyether polyol (e.g. a polyoxypropylenel oxyethylene polyol) initiated with trimethylal propane (TMP), glycerine, hexanetriol or like diol or triol. A LMW polyol of too low a molecular weight causes prepolymer gelation problems. Too high of a molecular weight impedes the cure of the final polymer.
The present quasi-prepolymer is also unique in that, despite its high FNCO, it is reasonably storage stable. By this is meant that while it probably is not safely shippable it can be stored for weeks in a plant at temperatures of about 90″F to about 1200F. The use of some liquid MDI from 1 to 20% by weight of the prepolymer helps in this regard in that it tends to disrupt crystallization. Storage of a prepolymer of this type at room temperature and at temperatures above 1200F favors dimer formation. The amount that forms is, of course, also dependent on the time in storage. However, storage in the optimum temperature range of about 90″ to llO”F gives the longest storage time with minimal dimerization.
To secure acceptable foam properties, the polyol side of the urethane foam system preferably uses as a polymer backbone a polyol that is relatively long-chained, i.e. it has a molecular weight in the range of 3000 to 6000, a functionality of 2 to 3 and preferably an equivalent weight of 1500 to 3000. It is typically capped with ethylene oxide to have a high level of primary hydroxyl groups.
Other recognized ingredients can be used in the polyol blend such as alkylene polyols, e.g. diol/triols, crosslinkers/extenders, organometallic and amine catalysts, carbon black, or blowing agents to tailor specific properties into the RIM foam systems.
The following proportions can be used in the polyol blend:
Parts by Weight
Long chain polyol 50 to 100
Aromatic and/or aliphatic polyamine 0 to 10
Alkane or oxyalkylene polyols 0 to 25
Amine catalyst 0.01 to 3.0
Organometallic catalyst 0.01 to 0.15
The alkane or oxyalkylene polyols can have molecular weight in the range of 62 to 250.
Examples of such crosslinkers/extenders are diethylene glycol, pentane diol, trimethylol propane, and 1, 2, 6 hexane triol. To give an acceptable cure the functionality of the polyol, e.g. triol or diol/triol mixture, should be 2.6 or greater.
Examples of suitable known amine catalysts are:
N-ethylmorpholine and TMBDA (tetramethylbutane diamine).
Examples of suitable known organometallic catalysts are dibutyl tin dilaurate and diacetate, stannous octoate and tin mercaptides.
Blowing agents that can be used include: methylene chloride, nitrogen, and DuPont’s
Freon 11 and Freon 12 (“Freon” is a Registered Trade Mark). Water can be used but may give rise to post blowing and paintability problems.
The foam formulations based on the quasi-prepolymer of this invention are so extremely reactive as not to be processable in conventional equipment. Commercially available equipment that can be used to process the present compositions include: Krauss-Maffei-164
PU40/PU80 (Standard Tool and Manufacturing Co., 237 Laurel Avenue, Kearny, New
Jersey 07032), Cannon H-100-2 (International Industrial Equipment Corporation, 438
Allegheny River Boulevard, Oakmont, Pennsylvania 15139) and Henneke HK-1000 and
KK-5000 (Mobay Chemical Company, Pittsburgh, Pennsylvania 15205).
Usually in the range of 0.6 to 0.7 parts by weight of the prepolymer of this invention will be admixed with each part by weight of the polyol blend.
Being so highly reactive the foam systems of this invention dramatically reduce mold-occupancy times. For normal systems in-mold cure times may be as much as two to three minutes whereas with this invention times under 100 seconds are easily obtainable and times under 50 seconds to demolding are the usual rule. Molded densities are preferably in the range of 45 to 72, more preferably 55 to 65 pounds per cubic foot.
Examples
The following blend was prepared and used in all of the examples, being referred to hereafter as the “Polyol Blend”:
Parts by weight
Polyether polyol (a) 84.92
BDO (2) 16.13
Ethylene glycol 0.93
Catalyst (3) 1.20
DBTDL (4) 0.02 102.50= (1) Mobay Chemical Company’s (Pittsburgh, Pennsylvania 15205) E-9207. It has a molecular weight of 4,000 and a functionality of 2.3. This polyol is a polyoxypropylene polyol within the range of 80 to 90 percent primary hydroxy groups, which are more reactive than secondary hydroxy groups. Other such polyols having a molecular weight in the range of 3000 to 6000, a functionality in the range of 2 to 3 and an equivalent weight in the range of 1500 to 3000 can be used. These include such high molecular weight diols, triols and blends as Jefferson Chemical Company, Inc.’s (260 Madison Avenue, New York, New
York) 6500; Union Carbide Corporation’s (South Charleston, West Virginia 25303) NIAX (Registered Trade Mark) 3128; BASF Wyandotte Corporation’s (Wyandotte, Michigan 48192) P-380; Olin Chemicals Division’s (275 Winchester Avenue, New Haven, Connecticut) Poly GX-442; and Dow Chemical Company’s (Freepost, Texas 77541) 4701.
(2) 1, 4 butane diol.
(3) 33% triethylene diamine in dipropylene glycol.
(4) Dibutyl tin dilaurate.
In the Examples and Tables that follow all parts and percentages are by weight unless otherwise indicated.
Example 1 – The Effect of Prepolymer FNCO
Urethane samples in the form of 0.125 thick plaques were prepared from the Polyol
Blend and various prepolymers using in all cases an isocyanate index (ratio of free NCO groups to available -OH groups or equivalent) of 105% in the reaction mixture. In practice, the Index used can be in the range of 98 to 108.
The prepolymer was made by reacting the MDI and polyol at about 1500F for 55-60 minutes under constant agitation and a nitrogen blanket. The 260 molecular weight triol was Dow Chemical Company’s (Freeport, Texas) Voranol (Registered Trade Mark) 2025.
MDI [methylene bis (4-phenyl isocyanate)] used in the example was Mobay’s Multathene
MM, 99.6%+ pure. Upjohn’s Isonate (Registered Trade Mark) 125M could also be used.
The prepolymer was allowed to cool to 1 100F which is its optimum storage temperature.
The Polyol Blend and the prepolymer were mixed by hand addition to a high-speed mixer and blended for 5 to 10 seconds. The blend was then quickly poured onto an aluminum mold (heated to 140-1500F), the mold was clamped and the foam was cured for 2 minutes.
The plaque was quickly demolded and bent back 1800, as previously described, to determine the state of cure. Cracking of substrate at 2 minutes is considered a failure. A slight crazing or change in transparency is considered marginal. A good cure does not crack or craze in 2 minutes.
The Chevrolet heat sag test is a cantilever test. A 1 x 5-inch sample is suspended with a 4-inch overhang in a hot air oven at 250″F for 1 hour. The sag is the change in height measured after the sample has been cooled to ambient temperature. Less than a 1-inch sag is desired.
Blowing agents may be used with any of these formulations but were not used as they make hand mixing of these extremely reactive polymers more difficult.
The Polyol Blend (102.57 grams) was mixed at llO”F with 103.7 grams of a 20% FNCO prepolymer prepared from pure MDI and a 260 molecular weight triol. The polymer produced, its mechanical, impact and cure properties, are set forth in Table I, Example
I-A.
Similarly, Samples I-B through I-E were prepared. The dramatic improvement in the temperature performance of the urethane at prepolymer FNCO’s of 27 and above is to be noted.
TABLE I
Effect of Prepolymer FNCO
(105% Isocyanate Index)
Prepolymer Blend I-A I-B I-C I-D I-E
Pure MDI 45.0 60.5 103.3 198.0 100.0 260 M. Wt. Triol 10.0 10.0 10.0 10.0 0
Prepolymer FNCO 20% 23% 27% 30% 33.6%
Reaction Mixture
Polyol Blend 102.57 102.57 102.57 102.57 102.57
Prepolymer Blend 103.70 87.20 73.20 66.20 58.80
Cure at 2 Mins. Excellent Excellent Excellent Excellent 30 Mins
Physical Properties
Tensile 2,730 1,890 1,790 1,560 1,430
Elongation 80% 93% 140% 130% 170%
Tear 454 354 314 300 350
Flex Modulus, RT 85,700 49,200 22,400 13,500 14,200
Specific Gravity 1.12 1.03 0.995 0.101 1.01
Chevy Sag, 250″F, 1 Hr 1.8 1.6 0.79 0.62 0.69
Cold Flex, -200F Failed Failed Passed Passed Passed
Conclusions – Example I
Example I demonstrates:
(a) As FNCO is increased, the temperature performance (both high and low) improves.
FNCO’s of 27% and above pass the test.
(b) The cure is acceptable except with the pure MDI. Pure MDI is, obviously, no longer a prepolymer system.
(c) The mechanical properties of polymers Examples I-C and I-D are close to those of
I-E which is the MDI one-shot that could not be cured. Example I-D showed the best temperature performance.
Example 2 – Effect of Polyol Functionality in Prepolymer
Tripropylene glycol, the Voranol 2025 and blends thereof to yield average functionalities (f) of 2.3, 2.5, and 2.7 were used to prepare the prepolymer. Molded plaques were prepared from the Polyol Blend as in the previous example. BASF Wyandotte Corporation’s TP-340 and Union Carbide’s LG-650 could also be used from the LMW Polyol.
The Polyol Blend (102.57 grams) was reacted with 66.2 gramsofpreolymer made by reacting 215.9 grams of pure MDI with 10 grams of tripropyleneglycolfunctionality 2.09 using the previously mentioned prepolymer reaction conditions. The polymer formulation and its properties are listed in Table II as Example II-A. Note the poor cure.
Similarly Examples II-B through II-H were prepared and evaluated.
TABLE II
Effects of Polymer Polyol Functionality (f) (105% Isocyanate Index)
II-A II-B II-C II-D II-E II-F II-G II-H
Polyol Blend (PBW) 102.57 102.57 102.57 102.57 102.57 102.57 102.57 102.57
Prepolymer Blend 66.2 66.2 66.2 66.2 66.2 73.2 87.2 103.7
FNCO 30% 30% 30% 30% 30% 27.0% 23% 20%
Pure MDI 215.9 210.8 207.4 204.0 206.6 113.2 66.7 49.8
TPG 10.0 7.0 5.0 3.0 — 10.0 10.0 10.0 260 M. Wt. Triol — 3.0 5.0 7.0 10 — — —
Avg. Functionality 2.0f 2.3f 2.5f 2.7f 3.0f 2.0f 2.0f 2.0f
Physical Properties
Cure at 2 minutes Failed Failed Failed Fair Passed Marginal Passed Passed
Cold Flex -20 F Passed Passed Passed Passed Passed Failed Failed Failed
Tensile 1,270 1,340 1,510 1,540 1,590 1,670 2,150 2,130
Elongation 260% 180% 240% 220% 220% 310% 240% 190%
Tear 311 356 320 324 315 388 396 445
Flex Modulus, RT 12,200 11,700 11,500 12,700 10,100 14,700 14,400 26,600
Specific Gravity 0.87 0.95 0.90 0.93 0.95 1.04 0.96 0.91
Chevrolet Sag, 250 F 1 Hr 1.5 1.0 0.95 0.71 0.57 2.6 1.6 1.4 Conclusions – Example II
(a) The most dramatic effect of polyol functionality is on cure. As the functionality increases the cure, as measured by the previously described test becomes better. Marginal cures are seen at 2.7f and 3.0f yields excellent cure. Below 2.6f the cure is unacceptable and somewhat above 3.lf the mechanical properties would deteriorate.
(b) The high temperature performance, i.e. sag, is improved dramatically with increase in functionality.
(c) Low temperature impact is improved as the functionality is increased.
A functionality of 3.0 at a 27% FNCO passes the cold flex test; a functionality of 2.0 at a 27% FNCO does not.
Example III- Effect of Prepolymer Polyol Molecular Weight
The molecular weight of the triol used in prepolymer were varied from 260 to 6500, while keeping the prepolymer FNCO at 30%. The 6500 molecular weight material was Jefferson
Chemical’s SF 6501 and the 260 molecular weight material was Voranol 2025. The other polyols were also commercially available materials of the molecular weight specified.
The Polyol Blend (102.57 grams) was reacted with 66.2 grams of a 30% FNCO prepolymer made by reacting 6.3 grams of a 6500 molecular weight triol and 58.3 grams of pure MDI. The resulting polymer would not cure in 5 minutes. See Table III, Example A.
Additional Examples III-B through III-G were prepared and evaluated as set out in
Table III.
TABLE III
Effect of Triol Molecular Weight on State of Cure
(105% Isocyanate Index)
Polyols Mol. Wgt. Cure Time
A – 6500 5 mins. +
B – 4500 5 mins. +
C – 3000 5 mins. +
D – 1600 3.5 mins.
E – 500 2 mins. Excellent
F – 340 2 mins. Excellent
G – 260 2 mins. Excellent
The mechanical and impact properties of the various polymers were about the same because of the small concentration of triol in the total formulation.
Conclusion – Example III
(a) The molecular weight of the polyoi used to make the prepolymer has a definite effect on the cure rate of the resulting polymer.
(b) The upper limit of triol molecular weight is from 500 (preferred) to 1,500 for acceptable cures.
Example IV – Effect of Liquid MDI Level
The amount of the liquid or modified MDI was varied from 0 to 100%. Upjohn’s Isonate 143D was used in this example. The purpose of this material is to maintain the prepolymer liquid under storage conditions. The MDI contains a small amount of some trimers and carbodiimides which disrupt the symmetry of the final prepolymer molecules and help keep the mixture liquid, which is a convenience. Mobay’s Mondur (Registered Trade Mark) CD could also be used.
The Polyol Blend (102.57 grams) was reacted with 62.9 grams of a prepolymer containing 10% liquid MDI and 90% of a 30% FNCO MDI/triol prepolymer. The liquid MDI was merely blended as the final step in the prepolymer reaction. It can, however, be added at any point during the reaction or any time after. Example IV-B shows the mechanical, impact and cure properties of this formulation.
Similarly, Examples IV-A and IV-C through IV-F were prepared.
TABLE IV
Effect of Liquid MDI Level (105% Isocyanate Index)
IV-A IV-B IV-C IV-D IV-E IV-F
Polymer Blend (PBW) 66.2 62.9 63.4 63.8 64.1 64.7 30% FNCO MDI/Triol
Prepolymer 100 90 70 50 30 0
Liquid MDI 0 10 30 50 70 100
Cure Pass Pass Pass Pass Pass Pass 2 min. 2 min. 2 min 2 min. 2 min. 2 min.
Physical Properties
Tensile 1,590 1,570 1,560 1,560 1,490 1,570
Elongation 220% 190% 180% 200% 200% 180%
Tear 315 311 312 297 290 315
Flex Modulus, RT 10,100 11,400 10,800 9,600 10,800 10,100
Specific Gravity 0.95 0.95 0.95 0.88 0.88 0.92
Chevrolet Sag, 250 F 1 Hr. 0.56 0.57 0.66 0.63 0.72 0.81
Cold Flex, -20 F Passed Passed Passed Passed Passed Passed Conclusions – Example IV (a) The high temperature performance as measured by the sag test degrades with increases in the concentration of liquid MDI. Levels of more than 50% liquid MDI result in a significant increase in sag. Also, liquid MDI is inherently more expensive than the triol prepolymer of MDI. Other mechanical, impact and cure properties remain about the same.
(b) A level of about 10% liquid MDI gave adequate storage stability with minimum effect on high temperature performance.
Example V – Automobile Exterior Trim Components
A 1977 Firebird front fascia (part #542092) was molded using a foam of this invention and an HK-1000 foam machine with impingement mixing. The prepolymer used was the same as that of Example IV-B. The polyol blend was just slightly modified from the Polyol
Blend of the Examples. Three parts by weight of an aromatic amine, Upjohn’s Curethane (Registered Trade Mark) 103 (See U.S. 3,575,896 and 3,681,291) was added to the Polyol
Blend along with 3 parts by weight of a blowing agent, trichlorotrifluoro ethane, duPont’s
Freon (Registered Trade Mark) 11. The mix proportions were adjusted to keep the Index at 105.
The Index was 105%, the prepolymer temperature was 110 F, the polyol temperature was 90″F and the mold temperature was 140″F. The part, a very complex front fascia, was removed 60 seconds after completion of the shot. Shot time was in the order of 3 seconds.
The resulting foam article had a density of 62 pounds per cubic foot, had excellent temperature performance (0.6 Chevrolet sag), and passed the Ford Cold Flex at -200F pained with PPG’s D-100 white paint. No problems with the painting or paint adhesion were encountered nor was any fading or discoloration noted.
A second molding, a 1978 Camaro (Registered Trade Mark) front bumper cover (part #356576) was also molded using the same formulation and similar processing conditions.
The bumper passed the painted impact tests at both high and low temperatures and was in all other respects satisfactory.

Claims (11)

WHAT WE CLAIM IS:

1. A liquid urethane quasi-prepolymer having a free isocyanate content in the range of 27 to 31% by weight composed 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 a polyether polyol and has a molecular weight in the range of 240 to 1500 and a functionality in the range of 2.6 to 3.3, said quasi-prepolymer being made by blending together said pure MDI and LMW polyol and allowing the blend to react at an elevated temperature.

2. The quasi-prepolymer of Claim 1 rendered storage stable when held at a temperature in the range of 90″ to 1200F by the addition thereto of 1 to 20 percent by weight of a liquid
MDI.

3. The quasi-prepolymer of Claim 1 wherein said LMW polyol is selected from polyoxyethylene and polyoxypropylene polyols.

4. A urethane foam made by reacting at an Isocyanate Index in the range of 98 to 108 the quasi-prepolymer of Claim 1 with a polyol blend of the following composition:
Parts by Weight
Long chain polyol 50 to 100
Aromatic and/or aliphatic polyamine 0 to 10
Alkane or oxyalkylene polyol 0 to 25
Amine catalyst 0.01 to 3.0
Organometallic catalyst 0.01 to 0.15 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.

5. The foam of Claim 4 wherein in the range of 0.6 to 0.7 parts by weight of said quasi-prepolymer are reacted with each part by weight of said polyol blend.

6. A urethane foam article made with the urethane foam of Claim 4 when made in a
RIM system as hereinbefore defined to a molded density in the range of 55 to 65 pounds per cubic foot with a demolding time of less than 2 minutes.

7. A quasi-prepolymer urethane foam formulation consisting of on the one hand a polyol blend and on the other hand a liquid quasi-prepolymer, viz:
(a) said polyol blend comprising:
Parts by Weight
Long chain polyol 50 to 100
Aromatic and/or aliphatic polyamine 0 to 10
Alkane or oxyalkylene polyol 0 to 25
Amine catalyst 0.01 to 3.0
Organometallic catalyst 0.01 to 0.15 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% by weight and comprising 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 a polyether polyol having a molecular weight in the range of 240 to 1500 and a functionality in the range of 2.6 to 3.3.

8. A urethane foam made by bringing together the polyol blend of claim 4 and quasi-prepolymer of claim 1 in a RIM as hereinbefore defined machine and at a prepolymer free isocyanate content in the range of 27 to 31% by weight and at an Isocyanate Index in the range of 98 to 108, injecting the resulting mixture into a closed cavity mold sized to give a foam density in the range of 45 to 72 pounds per cubic foot and demolding the foamed product in less than two minutes.

9. The urethane foam of Claim 8 when an automobile exterior trim component.

10. A urethane quasi-prepolymer according to claim 1 and substantially as hereinbefore described with reference to and as illustrated in the foregoing examples.

11. A urethane foam according to claim 4 and substantially as hereinbefore described with reference to and as illustrated in the foregoing examples.

GB10005/78A
1977-03-16
1978-03-14
Cold impact resistant urethane foam

Expired

GB1590554A
(en)

Applications Claiming Priority (1)

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Priority Date
Filing Date
Title

US05/778,001

US4102833A
(en)

1975-12-19
1977-03-16
Cold impact resistant urethane foam

Publications (1)

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GB1590554A
true

GB1590554A
(en)

1981-06-03

Family
ID=25111975
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Title
Priority Date
Filing Date

GB10005/78A
Expired

GB1590554A
(en)

1977-03-16
1978-03-14
Cold impact resistant urethane foam

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JP
(1)

JPS53113898A
(en)

AR
(1)

AR218902A1
(en)

AU
(1)

AU510197B2
(en)

CA
(1)

CA1112400A
(en)

DE
(1)

DE2811354A1
(en)

FR
(1)

FR2383976A1
(en)

GB
(1)

GB1590554A
(en)

IT
(1)

IT1105158B
(en)

MX
(1)

MX147645A
(en)

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US4341875A
(en)

1979-12-05
1982-07-27
Olin Corporation
High flexural modulus reaction injection molded urethanes

IT1229755B
(en)

1989-05-17
1991-09-10
Montedipe Spa
Poly:isocyanate compsn. for open cell flexible polyurethane foam – comprises polymethylene poly:phenyl poly:isocyanate and reaction prod. of di:isocyanate with polyether poly:ol

DE4205934A1
(en)

1992-02-27
1993-09-02
Basf Ag

METHOD FOR PRODUCING FLUOROCHLORINE HYDROCARBON-FREE, LOW-DENSITY POLYURETHANE SOFT FOAMS AND SOFT-ELASTIC POLYURETHANE FOAMS, AND USEFUL THEREOF, WITH URETIFYMETHANE DYPE, WITH POLYURETHANE

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Publication date
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Title

GB1479096A
(en)

1975-05-29
1977-07-06
Ici Ltd
Polymeric materials

1978

1978-03-14
GB
GB10005/78A
patent/GB1590554A/en
not_active
Expired

1978-03-15
FR
FR7807481A
patent/FR2383976A1/en
not_active
Withdrawn

1978-03-15
CA
CA298,940A
patent/CA1112400A/en
not_active
Expired

1978-03-16
MX
MX172789A
patent/MX147645A/en
unknown

1978-03-16
DE
DE19782811354
patent/DE2811354A1/en
not_active
Withdrawn

1978-03-16
IT
IT48464/78A
patent/IT1105158B/en
active

1978-03-16
JP
JP3046978A
patent/JPS53113898A/en
active
Granted

1978-03-16
AR
AR271451A
patent/AR218902A1/en
active

1978-03-20
AU
AU34328/78A
patent/AU510197B2/en
not_active
Expired

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Publication date

IT1105158B
(en)

1985-10-28

JPS5760364B2
(en)

1982-12-18

DE2811354A1
(en)

1978-09-28

MX147645A
(en)

1982-12-30

AU3432878A
(en)

1979-09-27

FR2383976A1
(en)

1978-10-13

AR218902A1
(en)

1980-07-15

JPS53113898A
(en)

1978-10-04

IT7848464D0
(en)

1978-03-16

AU510197B2
(en)

1980-06-12

CA1112400A
(en)

1981-11-10

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