GB2079286A - Foamed Urea-formaldehyde Resin Insulating Foams - Google Patents
Foamed Urea-formaldehyde Resin Insulating Foams Download PDFInfo
- Publication number
- GB2079286A GB2079286A GB8112217A GB8112217A GB2079286A GB 2079286 A GB2079286 A GB 2079286A GB 8112217 A GB8112217 A GB 8112217A GB 8112217 A GB8112217 A GB 8112217A GB 2079286 A GB2079286 A GB 2079286A
- Authority
- GB
- United Kingdom
- Prior art keywords
- resin
- acid
- surfactant
- urea
- hardener
- 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- Withdrawn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
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
- C08J9/12—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
- C08J9/14—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent organic
- C08J9/141—Hydrocarbons
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/18—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer of foamed material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
- B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
- B32B5/245—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it being a foam layer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2305/00—Condition, form or state of the layers or laminate
- B32B2305/72—Cured, e.g. vulcanised, cross-linked
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2361/00—Characterised by the use of condensation polymers of aldehydes or ketones; Derivatives of such polymers
- C08J2361/20—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen
- C08J2361/22—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with acyclic or carbocyclic compounds
- C08J2361/24—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with acyclic or carbocyclic compounds with urea or thiourea
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Abstract
A urea-formaldehyde (UF) resin foam of increased structural strength and reduced water absorbency compared with known UF foams is prepared by foaming a UF pre-polymer resin of viscosity in the range 4,000 to 10,000 cps in the presence of 0.4- 1.5 parts per 100 of resin, of an anionic surfactant and also in the presence of an acid hardener when the surfactant does not contain acid groups.
Description
SPECIFICATION
Improvements in Insulating Foams
This invention concerns improvements in insulating foams, more especially it concerns an improved urea-formaldehyde foam.
Urea-formaldehyde foams are well established as fills for post-construction insulation of cavity walls ofbuildings, and the technology is available in the published art. Known urea-formaldehyde foams, however, are mechanically weak, have high water absorption (in some cases exceeding 100% v/v) and readily transmit water vapour. We have studied these foams in recognition that their starting material costs are appreciably lower than those of phenol-formaldehyde foams and ureaformaldehyde offers a fire-resistence which is denied to polystyrene foams, with the aim of improving their physical properties to enable rigid building insulation panels to be made from ureaformaldehyde.
The present invention provides a method of producing a foamed urea-formaldehyde resin, which comprises foaming a urea-formaldehyde pre-polymer resin having a viscosity in the range of 4000 to 10,000 cps, in the presence of an anionic surfactant in an amount of 0.4 to 1.5 parts per hundred of resin, and, in the case in which the surfactant does not contain acid groups and is incapable of functioning as a hardener for the pre-polymer resin, in the presence of an acid hardener in an amount of 0.2 to 1.5 parts per hundred of resin.
The invention also provides a foamed ureaformaldehyde resin produced as defined above.
It has been found that the invention enables a relatively high density, relatively strong foam with low water absorption, compared to ureaformaldehyde foams as used in cavity wall insulation, to be made.
Urea-formaldehyde pre-polymer resins are commercially available from a number of sources as starting materials for cavity wall insulation foams. Such pre-polymer resins have viscosities around 850 cps, the viscosity varying with water content, which is of the order of 40 to 65%. We believe that foam quality is improved by reducing the water content, providing that the viscosity of the pre-polymer does not become so high that the resin becomes unworkable. We believe that a maximum desirable water content to achieve the benefits of the invention is 30% and we prefer the water content to be less than 27%. The water content of the pre-polymer resin can be reduced, and the viscosity increased, by distilling off the water under reduced pressure at moderately elevated temperatures, so that undesirable polymerisation is minimised or avoided.
The use of surfactants is known in foaming ureaformaldehyde resins, but we believe that it is critical to use an anionic surfactant to achieve adequate control of cell formation and to minimise the linking of cells by channels large enough to permit water absorption. The question of whether or not a foam is "closed-cell', which is a standard term used in the art of foaming plastics, is complex and we have found that most foams of allegedly "closed cell" form do have passages or pores linking the cells. Accordingly, we believe that the practical test of water absorbency is very much more relevant than any examination of the cells of the foam to determine the closed cell content. The present invention permits the production of foam of water absorbency of 10% (v/v) or less.
A number of suitabble anionic surfactants are commercially available and include LANKROPOL
WN, a sulphated fatty acid ester, EMPIMIN 3054, a blended foaming agent containing an alkyl ethoxylate sulphate, and NANSA 1042/P, which is a dodecylbenzene sulphonic acid.
The foamed resin requires to be hardened using an acid hardener. The use of phosphoric acid as an acid hardener is known and although it can be used effectively in the present invention it should be borne in mind that it is commonly available as a solution in water and hence water is being added to the resin. Similar considerations apply to mineral acids such as hydrochloric acid, with the added considerations that mineral acids cause corrosion problems and also are strong acids, so that only very small amounts are used and have to be adequately mixed with the resin mass or dilute solutions are used, thus adding water. It is therefore preferred to use organic acids which are in general weak acids. Especially preferred organic acids include p-toluene sulphonic acid and dodecylbenzene sulphonic acid.It will be appreciated that the latter is also an anionic surfactant so that the single compound can act as hardener and surfactant in the present invention. Foaming of the resin is accomplished in known manner, by admixing a blowing agent therewith. It is preferred to use pentane as the blowing agent.
Curing of the foamed resin is suitably accomplished by heating the mass of foamed resin at moderately elevated temperature, for example at 50--600 for several hours.
The cured foam may be in the form of preformed artefacts, as sheets or as a mass which is cut into sheets of desired dimensions. The cured foam, especially in the form of sheets or boards, may be laminated with one or more sheets of kraft paper, glass fibre paper or other web of woven or nonwoven fabric.
The present invention will now be described by way of example.
Example 1
An "Aerolite" (Trade name of Ciba Geigy) ureaformaldehyde pre-polymer resin of viscosity 850 cps is vacuum concentrated at 400C until a viscosity of 8000 cps (at 25 OC) is reached. 100 parts by weight of the resulting resin is mechanically mixed with 6 parts of pentane and 0.7 parts of NANSA 1042/P dodecylbenzene sulphonic acid (90% solution in water), and the mix is allowed to foam and cure by heating at 500C in an oven for 2 hours.
The resulting cured foam has a density of 37 kg/m3 and a compressive strength of 1 8.6x 104 N/m2. It exhibits a water absorbency of 7.7% vol/vol.
Example 2
100 parts by weight of the concentrated resin used in Example 1 is mechanically mixed with 6.5 parts of pentane, 1 part of EMPIMIN 3054 surfactant and 0.4 part of p-toluene sulphonic acid. Identical processing results in a cured foam of density 33 Kg/m3 and compressive strength of 1 4.9 > c 1 04N/m3. A water absorbency of 7.2% vol/vol was measured.
The thermal conductivity of these foams was measured and compared with that for phenolic or polystyrene foams. The average thermal conductivity of foams according to the present invention was 0.026 Wm-' 0C-1. The corresponding figure for other foams is about 0.030 W.m-' OC-l. It can thus be seen that the foams according to the present invention are better insulating materials than known foams.
Claims (9)
1. A method of producing a foamed ureaformaldehyde resin, which comprises foaming a urea-formaldehyde pre-polymer resin having a viscosity in the range of 4,000 to 10,000 cps, in the presence of an anionic surfactant in an amount of 0.4 to 1.5 parts per hundred of resin, and, in the case in which the surfactant does not contain acid groups and is incapable of acting as a hardener for the pre-polymer resin, in the presence of an acid hardener in an amount of 0.2 to 1.5 parts per hundred of resin.
2. A method according to claim 1, wherein the surfactant is a sulphated fatty acid ester.
3. A method according to claim 1, wherein the surfactant is an alkyl ethoxylate sulphate.
4. A method according to claim 1 , wherein the surfactant is dodecylbenzene sulphonic acid.
5. A method according to any one of claims 1 to 3 in which an acid hardener is used, wherein the acid is an organic acid.
6. A method according to claim 5, wherein the organic acid is p-toluene sulphonic acid.
7. A method according to any one of the preceding claims, wherein foaming is accomplished using pentane as the blowing agent.
8. A method according to claim 1, substantially as hereinbefore described with reference to the
Examples.
9. A cured foamed urea-formaldehyde resin produced by a method according to any one of the preceding claims.
1 0. A cured foamed urea-formaldehyde resin according to claim 9, in the form of a sheet or board.
1 A sheet or board according to claim 10, laminated on at least one major face thereof with kraft paper, glass fibre paper or other web of woven or non-woven fabric.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8112217A GB2079286A (en) | 1980-05-02 | 1981-04-16 | Foamed Urea-formaldehyde Resin Insulating Foams |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8014782A GB2075515A (en) | 1980-05-02 | 1980-05-02 | Urea-formaldehyde Resin Insulating Foams |
| GB8112217A GB2079286A (en) | 1980-05-02 | 1981-04-16 | Foamed Urea-formaldehyde Resin Insulating Foams |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2079286A true GB2079286A (en) | 1982-01-20 |
Family
ID=26275406
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8112217A Withdrawn GB2079286A (en) | 1980-05-02 | 1981-04-16 | Foamed Urea-formaldehyde Resin Insulating Foams |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2079286A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008009463A1 (en) * | 2006-07-20 | 2008-01-24 | Rockwool International A/S | Method of growing plants |
| US8020344B2 (en) | 2006-07-20 | 2011-09-20 | Rockwool International A/S | Method of growing plants |
| US8181390B2 (en) | 2006-07-20 | 2012-05-22 | Rockwool International A/S | Growth substrates, their production and their use |
-
1981
- 1981-04-16 GB GB8112217A patent/GB2079286A/en not_active Withdrawn
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008009463A1 (en) * | 2006-07-20 | 2008-01-24 | Rockwool International A/S | Method of growing plants |
| EA014993B1 (en) * | 2006-07-20 | 2011-04-29 | Роквул Интернэшнл А/С | Method of growing plants |
| US8020344B2 (en) | 2006-07-20 | 2011-09-20 | Rockwool International A/S | Method of growing plants |
| US8181390B2 (en) | 2006-07-20 | 2012-05-22 | Rockwool International A/S | Growth substrates, their production and their use |
| US8205380B2 (en) | 2006-07-20 | 2012-06-26 | Rockwool International A/S | Method of growing plants |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |