GB2034708A - Isocyanate Compositions - Google Patents
Isocyanate Compositions Download PDFInfo
- Publication number
- GB2034708A GB2034708A GB7936778A GB7936778A GB2034708A GB 2034708 A GB2034708 A GB 2034708A GB 7936778 A GB7936778 A GB 7936778A GB 7936778 A GB7936778 A GB 7936778A GB 2034708 A GB2034708 A GB 2034708A
- Authority
- GB
- United Kingdom
- Prior art keywords
- composition
- diisocyanate
- diphenylmethane diisocyanate
- diphenylmethane
- cyanohydrin
- 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- Withdrawn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
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C265/00—Derivatives of isocyanic acid
- C07C265/14—Derivatives of isocyanic acid containing at least two isocyanate groups bound to the same carbon skeleton
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C263/00—Preparation of derivatives of isocyanic acid
- C07C263/18—Separation; Purification; Stabilisation; Use of additives
-
- 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
- C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
- C08G18/76—Polyisocyanates or polyisothiocyanates cyclic aromatic
- C08G18/7657—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings
-
- 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
- C08G18/8061—Masked polyisocyanates masked with compounds having only one group containing active hydrogen
- C08G18/807—Masked polyisocyanates masked with compounds having only one group containing active hydrogen with nitrogen containing compounds
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Polyurethanes Or Polyureas (AREA)
Abstract
A liquid diisocyanate composition, useful in the manufacture of polyurethanes, comprises a diphenylmethane diisocyanate in which from 1 to 30% of the isocyanate groups have been reacted with a cyanohydrin of formula: <IMAGE> where each of R and R<1> is an optionally substituted C1-8 alkyl or cycloalkyl group or an optionally substituted aryl group, or R and R<1> taken together with the attached carbon atom form a cycloalkylidene radical.
Description
SPECIFICATION
Isocyanate Compositions
This invention relates to the manufacture of liquid isocyanate compositions based on diphenylmethane diisocyanate.
Diphenylmethane diisocyanate is a solid isocyanate available on the commercial scale and as available, normally consists largely of the 4,4'isomer with a minor proportion of the 2,4'isomer. The two isomers are both solids at room temperature having melting points of 420C and 360C respectively, commercial mixtures of the two isomers optionally containing the 2,2'-isomer in small quantities are also solid at room temperature.
One of the end-uses for diphenylmethane diisocyanate is in the manufacture of polyurethane rigid, semi-rigid or flexible foams and polyurethane microcellular plastics for example for use in shoe soles. The polyurethane foam or micro-cellufar plastics may be made by reacting the diisocyanate with a polyester polyol or polyether polyol and optionally a cross-linking agent, chain extender, catalysts, blowing agent, stabilizer or other conventional additive under such conditions that gas is generated to form a foam or micro-cellular product. In order that it may be incorporated at room temperature into the polyester polyol or polyether polyoi it is preferred that the diisocyanate to be used in the liquid state at room temperature.
Liquid diphenylmethane diisocyanate compositions are aiso useful for other end-uses where it is desirable that the diisocyanate be in the liquid form.
According to the present invention there is provided a liquid diphenylmethane diisocyanate composition which comprises a diphenylmethane diisocyanate in which from 1 to 30% of the isocyanate groups have been reacted with a cyanohydrin of formula:
where R and R1, which may be the same or different, may be an optionally substituted alkyl or cycloalkyl group containing from 1 to 8 carbon atoms or an optionally substituted aryl group, or where R and R1 taken together with the attached carbon atom form a cycloalkylidene radical.
The diphenylmethane diisocyanate which is reacted with the cyanohydrin may be for example dipllenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate and mixtures of these, optionally containing small amounts of the 2,2'-isomer. We prefer to use diphenylmethane-4,4'-diisocyanate containing not more than 25% of isomers thereof, and specially not more than 10% of isomers thereof.
Liquid diphenylmethane diisocyanate compositions of the present invention derived from substantially pure diphenylmethane-4,4'-diisocyanate are specially preferred.
Examples of suitable cyanohydrins include acetone cyanohydrin, cyclohexanone cyanohydrin and acetophenone cyanohydrin.
The liquid diphenylmethane diisocyanate composition preferably comprises a diphenylmethane diisocyanate in which from 5% to 20% of the isocyanate groups, for example approximately 10% of the isocyanate groups, have been reacted with the cyanohydrin.
In general, one mole of cyanohydrin reacts with two equivalents of isocyanate functionality. Thus, in order to obtain compositions in which from 1% to 30% of the isocyanate groups have been reacted with the cyanohydrin, 1 molar proportion of diphenylmethane diisocyanate is reacted with 0.01 to 0.30 molar proportions of cyanohydrin.
The reaction between the diphenylmethane diisocyanate and the cyanohydrin suitably take place at a temperature above the melting point of the diphenylmethane diisocyanate (42 OC for pure diphenylmethane-4,4'-diisocyanate) in the presence of a suitable catalyst. There is little advantage in operating at temperatures in excess of 2000C, and temperatures in the range 500C to 1 000C are preferred.
Suitable catalysts are for example tertiary amines (for example triethylene diamine) or metal or organometal salts (for example stannous octoate or dibutyl tin dilaurate). When reaction is complete, the catalyst is preferably deactivated, for example by precipitation, complex formation, neutralisation or distillation.
The diphenylmethane diisocyanate compositions of the present invention are liquid compositions which are stable to storage (that is to say that the compositions remain liquid at room temperature for long periods of time, sufficient in fact for all practical purposes), and can be transported or stored at low temperature without significant sedimentation of. crystals.
The compositions are suitable for applications (such as the manufacture of polyurethane rigid, semi-rigid or flexible foams and polyurethane microcellular products) in which their liquidity makes for easier incorporation into the reaction mixture and easier handling, for example by pumping.
The liquid diphenylmethane diisocyanate compositions of the present invention may be incorporated in a polyurethane reaction mixture as such or may be used in admixture with other isocyanate compositions such as tolylene diisocyanate, diphenylmethane diisocyanate prepolymers or the crude mixture containing 30% to 65% by weight of diphenylmethane diisocyanate together with methylene bridged polyphenyl polyisocyanates of higher functionality which is obtained from the phosgenation of the condensation product of aniline and formaldehyde.
The invention is illustrated by the following
Examples in which all parts and percentages are by weight unless otherwise stated.
Example 1
To 250 parts of molten diphenylmethane-4,4'diisocyanate at 800C was added 0.1 part of
DABCO (triethylenediamine) which gave a clear yellow solution.
The solution was stirred under dry nitrogen and 13.9 parts of cyclohexanone cyanohydrin were added slowly. The temperature was maintained at 80+20C throughout the addition and thereafter for a further hour.
On cooling, a yellow liquid product of low viscosity and having an isocyanate content of 27.4% by weight was obtained. The isocyanate
content of the 4,4'-diphenylmethane diisocyanate is 33.6%, indicating that apprbx, 10% of the isocyanate groups had been reacted in the product.
Example 2
To 250 parts of molten diphenylmethane-4,4'diisocyanate at 800C was added 0.1 part of stannous octoate. The solution was stirred under a blanket of dry nitrogen and 7.5 parts of acetone cyanohydrin were added slowly. The temperature was maintained at 80+20C for a further one hour after the addition was complete. On cooling, a yellow liquid product was obtained having an isocyanate value of 26.6%. The product remained liquid at ambient temperature.
Claims (10)
1. A liquid diphenylmethane diisocyanate composition which comprises a diphenylmethane diisocyanate in which from 1 to 30% of the isocyanate groups have been reacted with a cyanohydrin of formula:
where R and R1, which may be the same or different, may be an optionally substituted alkyl or cycloalkyl group containing from 1 to 8 carbon atoms or an optionally substituted aryl group, or where R and R1 taken together with the attached
carbon atom form a cycloalkylidene radical.
2. A composition as claimed in claim 1 wherein the diphenylmethane diisocyanate is diphenylmethane-4,4'-diisocyanate containing not more than 25% of isomers thereof.
3. A composition as claimed in claim 2 wherein the diphenylmethane-4,4'-diisocyanate contains not more than 10% of isomers thereof.
4. A composition as claimed in claim 1 wherein the diphenylmethane diisocyanate is substantially pure diphenylmethane-4,4'-diisocyanate.
5. A composition as claimed in any one of the preceding claims wherein from 5 to 20% of the isocyanate groups have been reacted with the cyanohydrin.
6. A composition as claimed in claim 1 substantially as hereinbefore described with reference to either of the foregoing Examples.
7. A method for the preparation of a diphenylmethane diisocyanate composition as defined in claim 1 which comprises reacting one molar proportion of diphenylmethane diisocyanate with 0.01 to 0.30 molar proportions of the cyanohydrin.
8. A method as claimed in claim 7 conducted substantially as hereinbefore described with reference to either of the foregoing Examples.
9. A liquid diphenylmethane diisocyanate composition whenever prepared by a method claimed in claim 7 or claim 8.
10. Polyurethanes whenever manufactured from a liquid diphenylmethane diisocyanate composition as claimed in any one of claims 1 to 6 and 9,
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7936778A GB2034708A (en) | 1978-11-03 | 1979-10-23 | Isocyanate Compositions |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7843146 | 1978-11-03 | ||
| GB7936778A GB2034708A (en) | 1978-11-03 | 1979-10-23 | Isocyanate Compositions |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2034708A true GB2034708A (en) | 1980-06-11 |
Family
ID=26269447
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7936778A Withdrawn GB2034708A (en) | 1978-11-03 | 1979-10-23 | Isocyanate Compositions |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2034708A (en) |
-
1979
- 1979-10-23 GB GB7936778A patent/GB2034708A/en not_active Withdrawn
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4031026A (en) | Diphenylmethane diisocyanate compositions | |
| US3124605A (en) | Biuret polyisocyanates | |
| US4229347A (en) | Liquid diphenylmethane diisocyanate compositions | |
| US4051165A (en) | Preparation of biuret polyisocyanates | |
| JP3236348B2 (en) | Process for the production of liquid storable organic isocyanates containing carbodiimide and / or uretonimine groups and their use for the production of polyurethane plastics | |
| US3392183A (en) | Preparation of biuret polyisocyanates | |
| US3766148A (en) | Polyurethane elastomers prepared from 4,4 - methylene-bis(cyclohexyl isocyanate),polyol and methylene dianiline | |
| US4332742A (en) | Low temperature storage stable liquid diphenylmethane diisocyanates | |
| EP0010850A1 (en) | Liquid polyisocyanate compositions | |
| EP0031650B1 (en) | Process for preparing liquid polyisocyanate compositions, and their use | |
| US5364897A (en) | Uretonimine-modified emulsifiable polyisocyanate compositions | |
| CA1118783A (en) | Storage-stable, liquid carbodiimide modified polyisocyanates and process for their manufacture | |
| US3954825A (en) | Biuret polyisocyanates | |
| EP0103996B1 (en) | Polyurea dispersions in organic isocyanates | |
| US3641093A (en) | Stable liquid diphenylmethane diisocyanates | |
| US3600358A (en) | Polyurethane-urea elastomers prepared from 4,4'-methylene bis (cyclohexyl-isocyanate),neopentyl adipate and an aromatic diamine | |
| EP0031207A1 (en) | Process for preparing liquid polyisocyanate compositions, and their use | |
| US4544763A (en) | Polyisocyanate binder having low toluene diisocyanate content | |
| US4552902A (en) | Process for preparing stable solutions of trimerized isocyanates in monomeric polyisocyanates | |
| CA1221487A (en) | Process for the production of urethane-modified polyisocyanate compositions | |
| JP2004505143A (en) | Diphenylmethane diisocyanate composition | |
| US4386032A (en) | Liquid polyisocyanate compositions | |
| US4322364A (en) | Modified isocyanate compositions | |
| US3899454A (en) | Process for the production of synthetic plastics comprising urethane groups and biuret groups | |
| GB2034708A (en) | Isocyanate Compositions |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |