US2050582A - Process of mercerizing cellulose material - Google Patents
Process of mercerizing cellulose material Download PDFInfo
- Publication number
- US2050582A US2050582A US719606A US71960634A US2050582A US 2050582 A US2050582 A US 2050582A US 719606 A US719606 A US 719606A US 71960634 A US71960634 A US 71960634A US 2050582 A US2050582 A US 2050582A
- Authority
- US
- United States
- Prior art keywords
- urea
- parts
- cellulose material
- mercerizing
- thiourea
- 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.)
- Expired - Lifetime
Links
- 229920002678 cellulose Polymers 0.000 title description 10
- 239000001913 cellulose Substances 0.000 title description 10
- 239000000463 material Substances 0.000 title description 10
- 238000000034 method Methods 0.000 title description 8
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 25
- 239000000203 mixture Substances 0.000 description 19
- UMGDCJDMYOKAJW-UHFFFAOYSA-N thiourea Chemical compound NC(N)=S UMGDCJDMYOKAJW-UHFFFAOYSA-N 0.000 description 16
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 10
- 150000001875 compounds Chemical class 0.000 description 10
- 125000001477 organic nitrogen group Chemical group 0.000 description 10
- 239000004202 carbamide Substances 0.000 description 9
- 238000009736 wetting Methods 0.000 description 8
- 150000003739 xylenols Chemical class 0.000 description 8
- 239000012670 alkaline solution Substances 0.000 description 5
- 229920000742 Cotton Polymers 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 238000012986 modification Methods 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 150000003585 thioureas Chemical class 0.000 description 3
- DMSHKWHLXNDUST-UHFFFAOYSA-N (4-methylphenyl)urea Chemical compound CC1=CC=C(NC(N)=O)C=C1 DMSHKWHLXNDUST-UHFFFAOYSA-N 0.000 description 2
- SNDGLCYYBKJSOT-UHFFFAOYSA-N 1,1,3,3-tetrabutylurea Chemical compound CCCCN(CCCC)C(=O)N(CCCC)CCCC SNDGLCYYBKJSOT-UHFFFAOYSA-N 0.000 description 2
- UWHSPZZUAYSGTB-UHFFFAOYSA-N 1,1,3,3-tetraethylurea Chemical compound CCN(CC)C(=O)N(CC)CC UWHSPZZUAYSGTB-UHFFFAOYSA-N 0.000 description 2
- QTWJRLJHJPIABL-UHFFFAOYSA-N 2-methylphenol;3-methylphenol;4-methylphenol Chemical compound CC1=CC=C(O)C=C1.CC1=CC=CC(O)=C1.CC1=CC=CC=C1O QTWJRLJHJPIABL-UHFFFAOYSA-N 0.000 description 2
- -1 N-butyl-N-cyclohexyl thiourea Chemical compound 0.000 description 2
- 229930003836 cresol Natural products 0.000 description 2
- 239000006260 foam Substances 0.000 description 2
- 150000002989 phenols Chemical class 0.000 description 2
- 150000003254 radicals Chemical class 0.000 description 2
- BLSVCHHBHKGCSQ-UHFFFAOYSA-N (2-methylphenyl)urea Chemical compound CC1=CC=CC=C1NC(N)=O BLSVCHHBHKGCSQ-UHFFFAOYSA-N 0.000 description 1
- LUBJCRLGQSPQNN-UHFFFAOYSA-N 1-Phenylurea Chemical compound NC(=O)NC1=CC=CC=C1 LUBJCRLGQSPQNN-UHFFFAOYSA-N 0.000 description 1
- OSDLLIBGSJNGJE-UHFFFAOYSA-N 4-chloro-3,5-dimethylphenol Chemical compound CC1=CC(O)=CC(C)=C1Cl OSDLLIBGSJNGJE-UHFFFAOYSA-N 0.000 description 1
- UHGKYJXJYJWDAM-UHFFFAOYSA-N Propylthiourea Chemical compound CCCNC(N)=S UHGKYJXJYJWDAM-UHFFFAOYSA-N 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 125000002947 alkylene group Chemical group 0.000 description 1
- 125000003710 aryl alkyl group Chemical group 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 150000005840 aryl radicals Chemical class 0.000 description 1
- 229960005443 chloroxylenol Drugs 0.000 description 1
- 125000000753 cycloalkyl group Chemical group 0.000 description 1
- 125000004990 dihydroxyalkyl group Chemical group 0.000 description 1
- 125000002768 hydroxyalkyl group Chemical group 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 125000004433 nitrogen atom Chemical group N* 0.000 description 1
- 150000002897 organic nitrogen compounds Chemical class 0.000 description 1
- SKJJGBRWKOFYAD-UHFFFAOYSA-N piperidin-1-ylurea Chemical compound NC(=O)NN1CCCCC1 SKJJGBRWKOFYAD-UHFFFAOYSA-N 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- ZJHHPAUQMCHPRB-UHFFFAOYSA-N urea urea Chemical compound NC(N)=O.NC(N)=O ZJHHPAUQMCHPRB-UHFFFAOYSA-N 0.000 description 1
- 150000003672 ureas Chemical class 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
- D06M11/32—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with oxygen, ozone, ozonides, oxides, hydroxides or percompounds; Salts derived from anions with an amphoteric element-oxygen bond
- D06M11/36—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with oxygen, ozone, ozonides, oxides, hydroxides or percompounds; Salts derived from anions with an amphoteric element-oxygen bond with oxides, hydroxides or mixed oxides; with salts derived from anions with an amphoteric element-oxygen bond
- D06M11/38—Oxides or hydroxides of elements of Groups 1 or 11 of the Periodic Table
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M13/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment
- D06M13/10—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing oxygen
- D06M13/152—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing oxygen having a hydroxy group bound to a carbon atom of a six-membered aromatic ring
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M13/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment
- D06M13/322—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing nitrogen
- D06M13/402—Amides imides, sulfamic acids
- D06M13/432—Urea, thiourea or derivatives thereof, e.g. biurets; Urea-inclusion compounds; Dicyanamides; Carbodiimides; Guanidines, e.g. dicyandiamides
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S516/00—Colloid systems and wetting agents; subcombinations thereof; processes of
- Y10S516/01—Wetting, emulsifying, dispersing, or stabilizing agents
- Y10S516/07—Organic amine, amide, or n-base containing
Definitions
- the present invention relates to an improvement in the process of mercerizing cellulose material.
- More particularly our invention consists in adding to the mercerizing baths a mixture of purpose comprise mixtures of phenols, halogenated or otherwise substituted derivatives thereof with urea or thiourea compounds being substituted at the nitrogen atom by organic radicals.
- radicals are, for instance, alkyl, alkylene, hydroxy alkyl, dihydroxy alkyl, cycloalkyl, aralkyl, or aryl radicals.
- the amount of. the said urea or thiourea compounds contained in the mixtures may be any one above about 2%, but preferably the mixtureconsists of about of phenols and about 10% of the urea or thiourea compounds.
- the mercerizing liquors prepared according to our invention are distinguished by excellent wetting properties, so that the cellulose material treated therein is quickly and homogeneously penetrated.
- the tetraalkyl derivatives of urea or thioureathere is involved the further advantage that the solutions show improved wetting capacity without at the same time forming foams.
- Example 1 To a meroerizing bath of 30 B. are added 1% by vol. of a mixture of 40 parts of crude cresol, 40 parts of crude xylenol and 20 parts of N-butyl-N'-dihydroxy propyl thiourea. Raw cotton placed into the'clear solution is immediately wetted.
- Example 2 To a mercerizing bath of 28 B6. are added 1.5% by volume of a mixture of 7 parts of mono phenyl urea, 50 parts of crude cresol and 43 parts of crude xylenol; the mercerizing lyepos- 5 sesses an outstanding wetting capacity.
- Example 4 To a bath of 28 B. are added 1% by volume of a mixture of 90 parts of crude xylenol and 10 10 parts of piperidyl urea; a raw cotton thread placed into the bath sinks down swiftly.
- Example 5 1.2% by volume of a mixture of 90 parts of 15 crude xylenol, 9 parts of tetrabutyl urea and 1 part of tetraethyl urea are added to a mercerizing bath of 30 B.
- the clear solution which hardly foams, possesses a good wetting capacity.
- Example 6 0.9% by volume of a mixture of parts of 30 xylenol and 5 parts of p-toluylurea are added to a mercerizing bath which hereby obtains wetting capacity for raw cotton. Instead of p-toluyl urea also mor o-toluyl urea can be used.
- Example 8 The wetting capacity of mercerizing baths will be improved by adding 1.2% by volume of a mixture of 90 parts of xylenol and 10 parts of N-butyl-N-cyclohexyl thiourea.
- Example 9 The wetting capacity of mercerizing baths will be improved by adding a mixture of 20 parts of chloroxylenol, 70 parts of xylenol, 5 parts of 45 tetraethyl urea and 5 parts of tetrabutyl urea. Cotton fibers placed into the bath are quickly and homogeneously penetrated.
- Example 10 0 1.2% by volume of a mixture of 92 parts of xylenol and 8 parts of N-N'-ethylene urea is added to a mercerizing bath of about 28 B. The solution shows an excellent wetting capacity. 5
- amount of the organic nitrogen containing compound is about 10%. calculated upon the amount of phenol present.
- a phenol and tetraallwl derivative oian organic nitrogen-containing compound selected from the group consisting of urea and thiourea.
- composition of matter suitable for the alkaline treatment of cellulose material comprising an aqueous alkaline lye,
- a composition of matter suitable for the alkline treatment of cellulose material comprising an aqueous alkaline lye, a phenol and a monophenyl derivative of an organic nitrogen-containing compound selected from the group consisting of urea .and thiourea.
- composition of matter suitable for the alkaline treatment of cellulose material comprising an aqueous alkaline lye. a phenol and a tetrabutyl derivative of an organic nitrogen containing compound selected 40 from the group consisting of urea and thiourea.
Landscapes
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Chemical Or Physical Treatment Of Fibers (AREA)
Description
Patented Aug. 11, 1936 UNITED STATES PATENT OFFICE raoonss or momma CELLULOSE MATERIAL Ludwig Orthner, Leverkusen-I. G. Work, and Werner Siefken, Cologne, Germany, assignors ,to I. G. Farbenindustrie Aktiengesellschaft,
Frankfort-on-the-Main, Germany No Drawing. Application April 7, 1934. Serial In Germany April 15, 1933 14 Claims. (01. a zo) The present invention relates to an improvement in the process of mercerizing cellulose material.
More particularly our invention consists in adding to the mercerizing baths a mixture of purpose comprise mixtures of phenols, halogenated or otherwise substituted derivatives thereof with urea or thiourea compounds being substituted at the nitrogen atom by organic radicals. Such radicals are, for instance, alkyl, alkylene, hydroxy alkyl, dihydroxy alkyl, cycloalkyl, aralkyl, or aryl radicals.
The amount of. the said urea or thiourea compounds contained in the mixtures may be any one above about 2%, but preferably the mixtureconsists of about of phenols and about 10% of the urea or thiourea compounds.
The mercerizing liquors prepared according to our invention are distinguished by excellent wetting properties, so that the cellulose material treated therein is quickly and homogeneously penetrated. By using the tetraalkyl derivatives of urea or thioureathere is involved the further advantage that the solutions show improved wetting capacity without at the same time forming foams.
All the substances which are employed in carrying out our invention are very stable in alkaline solutions and are therefore not decomposed and made inefiective even by prolonged use of the mercerizing bath.
The following examples will further illustrate the nature of our said invention which, however, is not limited thereto. The parts are by weight.
Example 1 To a meroerizing bath of 30 B. are added 1% by vol. of a mixture of 40 parts of crude cresol, 40 parts of crude xylenol and 20 parts of N-butyl-N'-dihydroxy propyl thiourea. Raw cotton placed into the'clear solution is immediately wetted.
Example 2 Example 3 To a mercerizing bath of 28 B6. are added 1.5% by volume of a mixture of 7 parts of mono phenyl urea, 50 parts of crude cresol and 43 parts of crude xylenol; the mercerizing lyepos- 5 sesses an outstanding wetting capacity.
Example 4 To a bath of 28 B. are added 1% by volume of a mixture of 90 parts of crude xylenol and 10 10 parts of piperidyl urea; a raw cotton thread placed into the bath sinks down swiftly.
Example 5 1.2% by volume of a mixture of 90 parts of 15 crude xylenol, 9 parts of tetrabutyl urea and 1 part of tetraethyl urea are added to a mercerizing bath of 30 B. The clear solution, which hardly foams, possesses a good wetting capacity.
Example 6 Example 7 0.9% by volume of a mixture of parts of 30 xylenol and 5 parts of p-toluylurea are added to a mercerizing bath which hereby obtains wetting capacity for raw cotton. Instead of p-toluyl urea also mor o-toluyl urea can be used.
Example 8 The wetting capacity of mercerizing baths will be improved by adding 1.2% by volume of a mixture of 90 parts of xylenol and 10 parts of N-butyl-N-cyclohexyl thiourea.
Example 9 The wetting capacity of mercerizing baths will be improved by adding a mixture of 20 parts of chloroxylenol, 70 parts of xylenol, 5 parts of 45 tetraethyl urea and 5 parts of tetrabutyl urea. Cotton fibers placed into the bath are quickly and homogeneously penetrated.
Example 10 0 1.2% by volume of a mixture of 92 parts of xylenol and 8 parts of N-N'-ethylene urea is added to a mercerizing bath of about 28 B. The solution shows an excellent wetting capacity. 5
thiourea.
2. The process claimed in claim 1, wherein the a we claim:-
1. In the process of treating cellulose material with an alkaline solution containing a' phenol, the modification which consists in effecting the said treatment in the presence of an organic nitrogen-containing compound selected from the group consisting oi thealiphatic, cycloaliphatim, araliphatic and aromatic derivatives of urea and amount of the organic nitrogen containing compound is more than about 2%, calculated upon the amount of phenol present.
3. The process claimed in claim 1, wherein the,
amount of the organic nitrogen containing compound is about 10%. calculated upon the amount of phenol present.
4. In the process of treating cellulose material with an alkaline solution containinga phenol, the modification which consists in effecting the said treatment in the presence oi a tetraalkyl derivative of an organic nitrogen containing compound selected irom the group consistingot urea and thiourea. i
5. In the process of treating cellulose material with an alkaline solution containing a phenol,
the modification which consists in eilecting the said treatment in the presence of a tetraethyl derivative of an organic nitrogen containing compound selected from the group consisting of ali-' phati'c cycloaliphatic, araliphatic and aromatic .derivatives of urea and thiourea.
8. The composition defined in claim 7, wherein the amount of the organic nitrogen-containing compound is more than about 2%, calculated 5 composition comprising an aqueous alkaline lye.
a phenol and tetraallwl derivative oian organic nitrogen-containing compound selected from the group consisting of urea and thiourea.
11. A composition of matter suitable for the alkaline treatment of cellulose material, said composition comprising an aqueous alkaline lye,
a phenol and a tetraethyl derivative of an organic nitrogen compound selected from the group I consisting of urea and thiourea.
12., A composition of matter suitable for the alkline treatment of cellulose material, said composition comprising an aqueous alkaline lye, a phenol and a monophenyl derivative of an organic nitrogen-containing compound selected from the group consisting of urea .and thiourea.
13. In the process of treating cellulose material with an alkaline solution containing a phenol, the modification which consists in effecting the said treatment in the presence of a tertabutyl derivative of an organic nitrogen containing compound selected from the group consisting of urea and thiourea.
14.'A composition of matter suitable for the alkaline treatment of cellulose material, said composition comprising an aqueous alkaline lye. a phenol and a tetrabutyl derivative of an organic nitrogen containing compound selected 40 from the group consisting of urea and thiourea.
LUDWIG ORTHNER. ,WARNER SIEFKEN.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE436660X | 1933-04-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2050582A true US2050582A (en) | 1936-08-11 |
Family
ID=6506930
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US719606A Expired - Lifetime US2050582A (en) | 1933-04-15 | 1934-04-07 | Process of mercerizing cellulose material |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US2050582A (en) |
| FR (1) | FR771856A (en) |
| GB (1) | GB436660A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3127347A (en) * | 1964-03-31 | Lubricating composition | ||
| US3190763A (en) * | 1960-12-17 | 1965-06-22 | Hoechst Ag | Process for the anti-static finishing of high molecular weight compounds |
| US3937726A (en) * | 1966-04-22 | 1976-02-10 | Hoechst Aktiengesellschaft | Urea derivatives and their use as herbicides |
| US3984468A (en) * | 1967-08-12 | 1976-10-05 | Bayer Aktiengesellschaft | Herbicidal N-trifluoromethylmercaptophenyl ureas |
-
1934
- 1934-04-07 US US719606A patent/US2050582A/en not_active Expired - Lifetime
- 1934-04-14 FR FR771856D patent/FR771856A/en not_active Expired
- 1934-04-16 GB GB11463/34A patent/GB436660A/en not_active Expired
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3127347A (en) * | 1964-03-31 | Lubricating composition | ||
| US3190763A (en) * | 1960-12-17 | 1965-06-22 | Hoechst Ag | Process for the anti-static finishing of high molecular weight compounds |
| US3937726A (en) * | 1966-04-22 | 1976-02-10 | Hoechst Aktiengesellschaft | Urea derivatives and their use as herbicides |
| US3984468A (en) * | 1967-08-12 | 1976-10-05 | Bayer Aktiengesellschaft | Herbicidal N-trifluoromethylmercaptophenyl ureas |
Also Published As
| Publication number | Publication date |
|---|---|
| FR771856A (en) | 1934-10-18 |
| GB436660A (en) | 1935-10-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE2506799A1 (en) | PROCESS FOR STABILIZING ALKALINE SILICATE CONTAINING PEROXIDE BLEACHING FLOTS | |
| US2050582A (en) | Process of mercerizing cellulose material | |
| GB853179A (en) | A method for improving the textile processing of artificial fibres and threads derived from polyesters | |
| US2572217A (en) | Manufacture of viscose rayon | |
| AU663913B2 (en) | A method for the treatment of wool | |
| US2427097A (en) | Shrinkproofing and feltproofing of keratinous textile fibers | |
| US1851914A (en) | Manufacture and use of new wetting preparations | |
| US2200603A (en) | Method for the improving of goods | |
| DE1617126C3 (en) | Machine detergent | |
| EP0112801B1 (en) | Magnesium complexes of oligomeric phosphonic-acid esters, process for their preparation and their use as stabilizers in bleaching baths containing alcaline peroxide | |
| US2423261A (en) | Germicidal product and method of producing same | |
| CA1148704A (en) | Use of alkylpolyglycol-tert.-butylether as bleaching auxiliary and bleaching baths containing this agent | |
| US2104290A (en) | Treating fibrous materials with alkaline liquids of mercerizing strength | |
| US2195194A (en) | Treatment of fibrous materials | |
| US3508942A (en) | Process for the manufacture of optically brightened shaped products from regenerated cellulose | |
| US1941059A (en) | Treatment of filling and reenforcing materials used in plastic compositions | |
| US1741496A (en) | Process for stripping rags with sulphur dioxide | |
| US1964934A (en) | Protection of animal fibers against the effects of alkaline or acid mediums | |
| DE1545185A1 (en) | Process for the production of antifoams | |
| US4494952A (en) | Wetting agents and their use as mercerizing assistants | |
| US2220805A (en) | Treatment for animal fiber | |
| US1977533A (en) | Method of desulphurizing rayon | |
| US3704262A (en) | Surfactant for electrolyte-containing processing solutions | |
| US1895681A (en) | Nonacid salt of diamino-dihydroxy-arsenobenzene dimethylene-sulphonic acid | |
| GB916576A (en) | Improvements in the purification of triaryl phosphates |