GB2112006A - Polyisocyanurate foam - Google Patents
Polyisocyanurate foam Download PDFInfo
- Publication number
- GB2112006A GB2112006A GB08222064A GB8222064A GB2112006A GB 2112006 A GB2112006 A GB 2112006A GB 08222064 A GB08222064 A GB 08222064A GB 8222064 A GB8222064 A GB 8222064A GB 2112006 A GB2112006 A GB 2112006A
- Authority
- GB
- United Kingdom
- Prior art keywords
- weight
- component
- catalyst
- promotes
- less
- Prior art date
- 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.)
- Withdrawn
Links
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
- C08G18/08—Processes
- C08G18/09—Processes comprising oligomerisation of isocyanates or isothiocyanates involving reaction of a part of the isocyanate or isothiocyanate groups with each other in the reaction mixture
- C08G18/095—Processes comprising oligomerisation of isocyanates or isothiocyanates involving reaction of a part of the isocyanate or isothiocyanate groups with each other in the reaction mixture oligomerisation to carbodiimide or uretone-imine groups
-
- 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
- C08G18/4833—Polyethers containing oxyethylene units
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Polyurethanes Or Polyureas (AREA)
Abstract
A method of manufacturing a polymeric foam comprises mixing together and allowing to react (a) an organic polyisocyanate; (b) a polyoxyalkylene polyol having a molecular weight of not less than 2000 and containing oxyethylene and optional oxypropylene residues, the former in an amount of not less than 10% by weight of the total alkylene oxide residues present; (c) a catalyst which promotes the trimerisation of (a); either (d) water; or (e) a catalyst, other than a catalyst containing methanol or furfuryl alcohol, which promotes the formation of carbodiimide linkages; or both (d) and (e); and optionally (f) a blowing agent and/or minor amounts of other conventional polyurethane foam ingredients; the weight of component (a) being from 5 to 15 times the weight of component (b), the weight of component (b) being from 5 to 30 times the weight of component (d), and the Isocyanate Index of components (a) to (f) being greater than 100. The method is directed towards reducing the cracking of char formed when rigid polyisocyanurate foam is burned.
Description
SPECIFICATION
Polymeric foam
This invention relates to polymeric foam and more particuFarfyto rigid polyisocyanurate foam which may cnrtain carbodiimide linkages.
ft is well' known that polyisocyanurate foam is more rnsistantto fire than other isocyanate-based foam. When burned it chars but tends not to support combustion and propagate fire. For this reason, it is used in preference to other isocyanate-based foam as a sound and thermal insulating material in the building industry.
Unfortunately the char formed when polyisocyanurate foam is burned has a tendency to crack allowing flanes to penetrate it and heat to be conducted through it.
The present invention is concerned with making charred polyisocyanurate foam more resistant to cracking.
According to the present invention there is provided a method of manufacturing a polymeric foam which comprises mixing together and allowing to react (a) an organic polyisocyanate; (b) a polyoxyalkylene polyol having a molecular weight of not less tham 2000 and containing oxyethylene and optionally oxypropylene residues, the former in an amount of not less than 10% by weight of the total alkylene oxide residues present; (c) a catalyst which promotes the trimerisation of (a); either (d) water; or (e) a catalyst. other than a catalyst containing methanol or furfuryl alcohol, which promotes the formation of carbodiimide linkages; or both (d) and (e); and optionally (f) a blowing agent andlor minor amounts of other conventional polyurethane foam ingredients; the weight of component (a) being from 5 to 15 times the weight of component (b), the weight of component (b) being from 5 to 30 times the weight af component (d), and the Isocyanate Index of companents (a) to (f) being greater than too. The invention atso includes the foam so obtained Bytheterm"lsocyanate Index" is meant one hundred titnes ttke ratio of free isoeyanate groups to isocyanatFrea ve groups which are present before reaction takes place.
Any organic polyisocyanate may be used as componeFatta}. Suitably it is selected from those polyìsoçyanates commonly used in the manufacture of polyi.socyanurate foams. These are well known to polyurelhane technologists and documented in the relavemt literature. Of particular interest are polyisocyanate compositions comprising dipheny Imethane diisocyanates and polymethylene polyphenyl polyisocyanates obtained in known man ner by the phosgenation of crude diaminodipheny Imethane. Such compositions are commanly referred to as crude or polymeric MDI.
Mixtures of polyisocyanates may be used and the polyisocyanate may take the form of a prepolymer
containing reactive isocyanate groups. Suitable pre
polymers are prepared by methods well known in the art in which an excess of an organic polyisocyanate or mixture of polyisocyanates is reacted with a
minor amount of an active hydrogen compound, for
example a polymeric or monomeric polyol.
Component (b) is traditionally a flexible foam
polyol. It may be a polyoxyethylene polyol or a poly(oxypropylene-oxyethylene)polyol of a mixture thereof. Such polyols and methods for their preparation have been fully described in the relevant literature, many of the polyols being commercially available. The polyfoxypropylene - oxyethylene )polyols include ethylene oxide - tipped polyoxypropylene polyols and other random or block copolymers obtained by reacting ethylene and propylene oxides with active hydrogen-containing initiators.
Normally they will betriols having a nominal hydroxyl equivalent weight of not less than 1000 and hydroxyl numbers of 56 or less.
Catalysts which promote the trimerisation of isocyanates to form products containing an isocyanate ring structure are well known and described in, for example, UK Patent Specification Nos. 809809, 837120 and 856372. Any such catalyst may be used as component (c). In particular, potassium acetate is mentioned.
Any catalyst which promotes the formation of carbodiimide linkages may be used as component (c) provided it is not a catalyst containing methanol orfurfuryl alcohol. Suitably it is a phospholine or phospholidine or an oxide or sulphide thereof. Such catalysts are described in US Patent Specification
Nos. 2663737,8 and 9 and 3657161. An example is 1 phenyl - 3 - methylphospholine oxide.
The reaction of water with the polyisocyanate and the formation of carbodiimide linkages generate carbon dioxide which acts as a blowing agent to form a foamed. If it is desired to reduce the density ofthefoamed product another blowing agent may be added. This may be a low boiling solvent, for example, trichlorofluoromethane.
Other conventional polyurethane foam ingredients which may optionally be used as component (f) include surfactants, fillers, fire retardants, pigments and dyes.
It has been found that the includion of a small amount of a low molecular weight polyol is beneficial in that it helps the foam-forming reaction to start smoothly. Ethylene glycol and diethylene glycol are particularly good in this respect Propylene glycol is not quite so effective The amount used may be about 1% by weight of the polyisocyanate. The amount of polyoxyalkylene polyol orwater used, both, may be reduced to accommodate it
Thefoam-forming components may be mixed in any convenient manner preferably using equipment designedforthis purpose. If desired, mutually inert components may be pre-blended to reduce the number of component streams requiring to be brought together in a final mixing step. It is often convenient to have a two-stream system in which one stream comprises the polyisocyanate and the other the remaining components ofthefoam-form- ing-mixture.
If desired, the density of the foamed product can be further modified by overpacking, that is to say foaming the reacting mixture in a space less than that which would be occupied by the resultant foam if the reaction mixture were allowed to rise freely.
It has been found that the addition of water or a catalyst which promotes the formation of carbodimide linkages to a polyisocyanurate foam-forming mixture, in accordance with the invention, leads to reduced cracking of the char formed when the foam is burned.
Claims (2)
1. A method of manufacturing a polymericfoam which comprises mixing together and allowing to react (a) an organic polyisocyanate; (b) a polyoxyalkylene polyol having a molecular weight of not less than 2000 and containing oxyethylene and optionally oxypropylene residues, the former in an amount of not less than 10% by weight of the total alkylene oxide residues present; (c) a catalyst which promotes the trimerisation of (a); either (d) water; or (e) a catalyst, otherthan a catalyst containing methanol or furfuryl alcohol, which promotes the formation of carbodiimide linkages; or both (d) and (e); and optionally (f) a blowing agent andlor minor amounts of other conventional polyurethane foam ingredients; the weight of component (a) being from 5 to 15 times the weight of component (b), the weight of component (b) being from 5 to 30 times the weight of component (d), and the Isocyanate Index of components (a) to (f) being greater than 100.
2. A method according to claim 1 substantially as herein described.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08222064A GB2112006A (en) | 1981-12-21 | 1982-07-30 | Polyisocyanurate foam |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8138388 | 1981-12-21 | ||
| GB08222064A GB2112006A (en) | 1981-12-21 | 1982-07-30 | Polyisocyanurate foam |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2112006A true GB2112006A (en) | 1983-07-13 |
Family
ID=26281588
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08222064A Withdrawn GB2112006A (en) | 1981-12-21 | 1982-07-30 | Polyisocyanurate foam |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2112006A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0585636A1 (en) * | 1992-08-06 | 1994-03-09 | Nisshinbo Industries, Inc. | Method for producing modified polyisocyanurate foams |
| US5371057A (en) * | 1992-08-06 | 1994-12-06 | Nisshinbo Industries, Inc. | Method for producing modified polyisocyanurate foams |
-
1982
- 1982-07-30 GB GB08222064A patent/GB2112006A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0585636A1 (en) * | 1992-08-06 | 1994-03-09 | Nisshinbo Industries, Inc. | Method for producing modified polyisocyanurate foams |
| US5371057A (en) * | 1992-08-06 | 1994-12-06 | Nisshinbo Industries, Inc. | Method for producing modified polyisocyanurate foams |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100210563B1 (en) | An isocyanate-terminated prepolymer and flexible polyurethane foam prepared therefrom | |
| CA1178400A (en) | Polymeric foams from transesterified by-product derived from manufacture of dimethyl terephthalate | |
| EP2812370B1 (en) | Method for producing a hard polyurethane-polyisocyanurate foamed material | |
| KR0150212B1 (en) | Isocyanate composition and process for making flexible foams therefrom | |
| US4898893A (en) | Blowing agents for isocyanurate foams and method for producing the same | |
| JP2945712B2 (en) | Method for producing polyisocyanate composition and method for producing flexible polymer foam using the composition | |
| EP0320134B1 (en) | Polyisocyanate compositions | |
| US4607064A (en) | Polyurethane and urethane-modified isocyanurate foams and a polyol composition useful in their preparation | |
| US5132040A (en) | Chemical blowing agent | |
| US4661529A (en) | Polyurethane and urethane-modified isocyanurate foams and a polyol composition useful in their preparation | |
| EP0398304B1 (en) | Flexible polyurethane foams and process for preparing them | |
| WO1994024183A1 (en) | Polyurethane foams | |
| EP0297687A2 (en) | Isocyanurate foam and method for producing the same | |
| JPH0770270A (en) | Production of rigid-polyurethane- or urethane-modified polyisocyanaurate foam | |
| NZ204401A (en) | Rigid urethane-modified isocyanurate foams | |
| GB2112006A (en) | Polyisocyanurate foam | |
| GB2099440A (en) | Rigid polymeric foams | |
| EP0486034B1 (en) | Flexible polyurethane foams and process for preparing them | |
| US5162386A (en) | Amine catalyst system for water-blown polyurethane foam | |
| US4115301A (en) | Cross-linker for flexible and semi-flexible polyurethane foams | |
| JP3358846B2 (en) | Method for producing low-density ultra-flexible urethane foam | |
| US5340845A (en) | Process for preparing low-density flexible polyurethane foams, and the polyurethane foams obtained | |
| US4075137A (en) | Process for preparing flame retarding polyurethane foams | |
| US5397811A (en) | Flexible polyurethane foams and process for preparing them | |
| JP3688313B2 (en) | Method for producing urethane-modified polyisocyanurate foam |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |