CA1097152A - Stabilized red phosphorus and process for making it - Google Patents
Stabilized red phosphorus and process for making itInfo
- Publication number
- CA1097152A CA1097152A CA292,173A CA292173A CA1097152A CA 1097152 A CA1097152 A CA 1097152A CA 292173 A CA292173 A CA 292173A CA 1097152 A CA1097152 A CA 1097152A
- Authority
- CA
- Canada
- Prior art keywords
- red phosphorus
- melamine
- phosphorus
- mono
- etherified
- 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
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/003—Phosphorus
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/003—Phosphorus
- C01B25/006—Stabilisation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/01—Treating phosphate ores or other raw phosphate materials to obtain phosphorus or phosphorus compounds
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Phenolic Resins Or Amino Resins (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Fireproofing Substances (AREA)
- Sampling And Sample Adjustment (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Stabilized red phosphorus consisting of particular with a size of at most about 2 mm and an oxidation sta-bilizer. The individual phosphorus particles are super-ficially covered with a thin film of a polycondensa-tion product of melamine and formaldehyde as the oxi-dation stabilizer, the polycondensation product being used in a proportion of about 1 to 20 weight %, based on the quantity of red phosphorus.
Stabilized red phosphorus consisting of particular with a size of at most about 2 mm and an oxidation sta-bilizer. The individual phosphorus particles are super-ficially covered with a thin film of a polycondensa-tion product of melamine and formaldehyde as the oxi-dation stabilizer, the polycondensation product being used in a proportion of about 1 to 20 weight %, based on the quantity of red phosphorus.
Description
~7~5~
i HOE 76/H o64K
This invention relates to stabilized red phospho-rus and to a process for making it, wherein red phos-phorus is stabilized by means of a synthetic resin.
It has been described that red phosphorus in a moist atmosphere undergoes a chemical surface reaction involvin~ oxidation and disproportionation with the resultan-t formation of ~arious acids of phosphorus : 10 (oxidation stages ~1 to ~5) and hydrogen phosphide.
As described by Gmelin, Handbuch der anorgan~schen Chemie, 8th edition (1964), vol. phosphorus, part B, page 83, ~erlag Chemie, Weinheim (Bergstrasse), red phosphorus can be stabilized by means o~ aluminum hy-droxide which is precipitated on the phosphorus par-ticles by the consecutive addition of a~ueous 10 %
sodium hydrogen carbonate and aluminum sulfate solu-tions heated to 55-60C. The resulting aqueous suspen-sion is filtered and the filter residue is dried. This process iS7 howevèr, not satis~actory in respect of the ~ollowing points. The disproportionately large quantities of aluminum hydroxide which are necessary to produce a satisfactor~ stabilizing effect conta-minate the phosphorus to an unacceptable extent and ad-versely affect is further widespread uses, A further process for stabilizing red phosphorus has been described in U.S. Patent Specification
i HOE 76/H o64K
This invention relates to stabilized red phospho-rus and to a process for making it, wherein red phos-phorus is stabilized by means of a synthetic resin.
It has been described that red phosphorus in a moist atmosphere undergoes a chemical surface reaction involvin~ oxidation and disproportionation with the resultan-t formation of ~arious acids of phosphorus : 10 (oxidation stages ~1 to ~5) and hydrogen phosphide.
As described by Gmelin, Handbuch der anorgan~schen Chemie, 8th edition (1964), vol. phosphorus, part B, page 83, ~erlag Chemie, Weinheim (Bergstrasse), red phosphorus can be stabilized by means o~ aluminum hy-droxide which is precipitated on the phosphorus par-ticles by the consecutive addition of a~ueous 10 %
sodium hydrogen carbonate and aluminum sulfate solu-tions heated to 55-60C. The resulting aqueous suspen-sion is filtered and the filter residue is dried. This process iS7 howevèr, not satis~actory in respect of the ~ollowing points. The disproportionately large quantities of aluminum hydroxide which are necessary to produce a satisfactor~ stabilizing effect conta-minate the phosphorus to an unacceptable extent and ad-versely affect is further widespread uses, A further process for stabilizing red phosphorus has been described in U.S. Patent Specification
2 359 243, wherein red phosphorus is suspended in a O,04 normal solution of sodium aluminate. Next, a stream of air is passed for 10 hours at 85 to 90C through the ~ .
3~097~5~
suspension, which is ~iltered, washed with hot water and dried under vacuum.
A still ~urther process ~or stabilizing red phos-phorus has been disclosed in U.S. Patent Specification 2 635 953, wherein aluminum hydroxide is used in com-bination with zinc or magnesium hydroxide~
The processes last described do equally not permit red phosphorus to be satisfactorily stabilized against ; oxidation with the use of a minimum of stabilizer.
1o The known oxidation stabilizers ha~e more speci-~ically an insufficient thermal stability and liberate water at higher temperatures, which is disadva~tageous.
In those cases in which plastics material rendered ~lame-retardant by means of recl phosphorus, which in turn has an oxidation stabilizer incorporated therein, are to be processed on an ex~ruder, it is an imperative re~uirement that the oxidation stabilizer combine in itsel~ thermal stability with non-liberation of water and undecomposability, e~en at temperatures higher than 300Co In accordance with our present invention, we have unexpectedly ~ound that red phosphorus can be satis-factorily stabilized by superficially covering the red phospho-rus particles with a hardened melamine-formaldehyde resin.
The present invention relates more particularly to stabilized pulverulent red phosphorus consistLng of particles with a size o~ at most about 2 mm and an oxi-dation stabilizer, whereLn the individual phosphorus particles are super~icially covered with a thin ~ilm _ 3 _ ~g~
of a polycondensation product of melamine and formalde-hyde as the oxidation stabilizer, the said polycondensa- ;
tion product being used in a proportion o~ about 1 to 20 weight %9 based on the quantity of red phosphorus.
In accordance with a preferred ~eature of the pre- ¦
sent invention9 the oxidation stabilizer is a partially etherified polycondensation product of melamine and formaldehyde.
A further pre~erred feature of the present inven-lo tlon provides for the individual phosphorus particles to be superficially covered with a thin film of the oxi-dation stabilizer which comprises a polycondensation p~oduct prepared by hardening a mononuclear, partially or completely methylolated melamine, whose methylol groups are unetherified or partially or completely etherified with at least one mono- or polyhydric ali-phatic C1-C6 alcohol; or by hardening a suitable poly-nuclear, partially or completely water miscible ~re liminary condensation product o~ melamine and form-aldehyde, the said preliminary condensation product containing melamine'and ~ormaldehyde in a molar ratio of 1:1 to 1:6 being unetherified or partially or com-pletely etherified w~th at least one mono- or polyhy-dric aliphatic C1-C6 alcohol; or by hardening a blend of the said unetheri~ied and/or etherified mononuclear methylolmelamines and/or unetherifîed or etherified polynuclear preliminary condensation products o~ mel-amine and formaldehyde; the polycondensation pr~duct being used in a proportion o~ about 1 to 20 weight %,.
based on the quantity of red phosphorus ~L~973l5Z
The oxidation stabilizers comprise more preferablya eOg. a polycondensation product prepared by hardening dimethylolmelamine, trimethylolmelamine, tetramethylol-melamine, pentamethylolmelamine, hexamethylolmelamine or a mixture thereo~; or a polycondensation product prepared by hardening a dimethylolmelamine, trimethylol-melamine, tetramethylolmelamine, pentamethylolmelamine or hexamethylolmelamine, of which the methylol groups are partially or completely e-therified with at least one mono- or polyhydric aliphatic C1-C6, preferably C1-C4 aliphatic alcohol. The mono- or polyhydric al-cohols which can be used in this invention may be saturated or unsaturated and have a carbon chain in-terrupted by one or more ether bridges. Suitable al-, cohols are, e,g~, the following: methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, n-pentanol, iso-pentanol, n-hexanol~ iso-hexanol, allyl alcohol, e-thylene glycol, propylene glycol or a butane diol, such as butane diol-1~4, a hexane diol, sucn as hexane diol-1,6, diethylene glycol, triethylene glycol, dipropylene glycol or glycerol, methanol being the pre-~erred aliphatic alcohol.
Commercially proven oxidation stabilizers com-prise those polycondensation products which are ob-tained by hardening a trimethylolmelamine-trimethyl-ether, hexamethylol-melamine-hexamethylether or penta-methylolmelamine-trimethylether.
A still further useful oxidation stabilizer is the ~ polycondensation product which is ob~ained by hardening a partially or completely water-miscible polynuclear - 5 ~
,. ' ~CI 97~SZ
preliminary condensation product of melamine and ~orm-aldehyde (briefly termed polynuclear methylolmelamine hereinafter) containing melamine and formaldehyde in a molar ratio of 1:1 to 1:~. The polynuclear preliminary condensation product of melamine and formaldehyde may be partially or completely etherified with the alcohols specified hereinabove. It is also possible for the mono-and polynuclear methylolmelamines to contain about 2 to 20 weight % of a modifying agent as commonly used in the aminoplast chemistry, the percentage being based on the mono- or polynuclear methylolmelamine. The modi-fying agents comprise9 ~or example~ sorbitol~ sugar,lac-tams, e.g, -caprolactam, methylene-bis-formamide, and toluene sulfonamides, e.g. paratoluene-sul~onamide.
With respect to the polycondensation product just described, it is pre~erable ~or it to be present in the stabilized pulverulent red phosphorus in a proportion o~ 2 to 10 weight %.
The present invention also relates to a process for making stabilized pulverulent red phosphorus con-sisting of particles with a size of at most about 2 mm and an oxidation stabilizer, which comprises: super-~icially wetting the indi~idual phosphorus particles by intimately blending them`with an aqueous about 1 to 95 weight % solution of a preliminary condensation product of melamine and formaldehyde; the preliminary condensation product being used in a proportion o~
about 1 to 20 weight %, based on the ~uantity of red phosphorus; hardening the preliminary condensation product; and drying the resulting stabilized red phos-.. . . . . .
phorus at elevated temperature.
Thus, for example, it is possible to use methyl-etherified trimethylolmelamine as the preliminary con-densation product, which is commercially available in the form of an about 75 weight % aqueous solution, It has a dynamic viscosity of L~50-600 centipoises at 20C, a pH of 8.2 to 9 2 at 20C, a density of 1.200 to 1.220 (g/ml) at 20C and a gelation period of 18 to 30 minutes at 20C in the presence of 0.2 weight % of para-toluenesulfonic acid.
A pre~erred version of the present process pro-vides for the individual phosphorus particles to be superficially wetted by intimately blending them with an aqueous, about 1 to ~5 weight ~ solution or suspen-t sion of a mononuclear, partially or completely methy-lolated melamine, whose methylol groups are unetheri-fied or partially or completel~ etherified with at least one mono- or polyhydric aliphatic C1-C6 alcohol;
or of a suitable polynuclear, partially or completely water-miscible preliminary condensation product o~
melamine and formaldehyde~ the said preliminary con-densation product containing melamine and formaldehyde in a molar ratio of 1:1 to 1:6 being unetherified or partially or comple-tely etherified with at least one mono- or polyhydric aliphatic C1-C6 alcohol; or o~
a blend of the said unetherified and/or etherified mononuclear methylolmelamines and/or unetherified or etherified polynuclear preliminary condensa-tion pro-duc-ts of melamine and formaldehyde; the said mono-or polynuclear methylolmelamine being used in a pro-'.
- 7 - ~
, , "~, `. : ~.
. .
~97~5Z
portion of about 1 to 20 weight %, based on the quan-tity of red phosphorus, hardening the mono- or poly-nuclear methylolmelamine, and drying the resulting sta-bilized red phosphorus at elevated temperature.
The individual phosphorus particles, which common ly have a size of 0.01 to 0.15 mm, may more pre~erably be wetted super~icially with the use of a 5 to 75 weight %
aqueous solution o~ one o~ the mono- or polynuclear9 etherified or unetherified methylolmelamines specified~
which should preferably be employed in a proportion of 2 to 10 weight ~/0, based on the quantity of red phos-phorus.
A ~urther preferred version of the present process provides ~or the individual phosphorus particles to be super~icially wetted with the use of an aqueous solu-tion or suspension of dimethylolmelamine~ trimethylol-melamine, tetramethylolmelamine, pentame-~hylolmelamine, hexamethylol~elamina or a mixture thereof, The methylol groups may be partially or completely -etherified with at least one mono- or polyhydric ali-phatic C1-C6, preferably C~-C4, aliphatic alcohol, e.g.
w-th metha~ol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, n-pentanol, iso-pentanol, n-hexa-nol, iso-hexanol, allyl alcohol, ethylene glycol, pro-` pylene glycol or a butane diol, such as butane diol-194,~
a hexane diol, such as hexane diol-1,6, diethylene gly-- col, triethylene glycol,jdipropylene glycol or glycerol.
I-t is particularly advantageous to super~lcially wet the individual phosphorus particles with a pbl~ondensation product of trimethylolmelamine trimethylether~ hexa-- :
~97~SZ
methylol hexamethylether or pentamethylol trimethyl-ether.
In wetting the phosphorus particles, it is possible to use the aqueous solution or suspension of the mono-or polynuclear methylolmelamine in admixture with about 2 ~to 20 weight % of a modifying agent as commonly used in the aminoplast chemistry7 the percentage being based on the mono- or polynuclear methylolmel~mine. The modi-~ying agents comprise, for example, sorbitol~ sugar9 lactams, : lo e.g. -caprolactamj methylene-bis-formamide, and toluene sulfonamides, e.g. para-toluene-sulfonamide.
The red phosphorus particles can more speci~ically be wetted, for example, as follows: ~n aqueous disper-sion of pulverulent red phosphorus is admixed with a predetermined quantity of an aqueous solution or sus-pension containing one or more of the mono- or polynuc-lear methylolmelami~es specified, and hardening is ini-tiated by acidifying and/or heating the aqueous disper-sion. After hardening, the aqueous dispersion is filtered the filter residue is water-washed and dried at a tem-perature, e.g. of 80 to 180C, if desired under reduced pressure.
The mono- or polynuclear methylolmelamines can also be hardened on the surface of the phosphorus par-ticles either by heat treatment at 100 to 180C or by acidifying the aqueous solution or suspension so as to establish a pH of ~ to 7. In those cases in which an aqueous solution o~ trimethylolmelamine trimethylether is employed, it i5 advantageous to e~fect the hardening at a pH of 3 to 5.
_ g _ ~97 ~SZ
The stabilized red phosphorus and ~he present pro-cess for making it compare favorably with the prior art products and methods inasmuch as the stabilizer is a thermally stable agent which is the firs-~ to permit the incorporation of stabilized red phosphorus into plastics material at temperatures higher than 250C.
The following Examples illustrate the invention.
E~AMPLE 1 150 ml of an aqueous phosphorus suspension which contained 100 g of pulverulent~red phosphorus, was diluted with 350 ml of water, the whole was admixed with 10 ml of an aqueous 75 weight ~ solution of a methyl-etherified trimethylol-melamine, and a pH of 3 was established by the addition of phosphoric acid ` of 5 % strength. ~he suspension was heated with àgi-ta-tlon to 90C, allowed to react for 30 minutes and filtered~ The filter residue was water-washed and dried at 100C in a s~ream of nitrog2n. The red phos-phorus so stabili~ed contained 7.5 weight ~ of melamine/
formaldehyde resin.
The red phosphorus so treated was tested for i-ts stability to oxidation. To this end, a three necked round flask provided with a tubular gas inlet, thermo-meter, reflux condenser and magnetic stirrer was charged with 450 ml of water and 1 g of red phosphorus, the mixture was heated to~80C and 10 lfh of oxygen was introduced thereinto with agîtation~ A gas mixture con-sisting of oxygen and hydrogen phosphide ~the latter, which was obtained together with acids o~ phosphorus of various oxidation stages, was formed by dispropor-- 10 - ~
:~97152 tionation of red phosphorus) le~t the reflux condenser.
It was delivered to two series-connected wash bottles-, which each contained 100 ml o~ a 5 weight % aqueous mercury(II) chloride solution~ The hydrogen phosphide underwent reaction with the mercury(II)chloride in accordance with the following equation:
PH3 ~ 3 HgCl2 - ~ P(HgCl)3 ~ 3 HCl The quantity of oxo acids o phosphorus present in the aqueous suspension of red phosphorus and the quan-tity of hydrochloric acid present in the gas washing bottles wers determined as an index of the stability to oxidation o~ red phosphorus. The content of phos-t~ phoric acid and the content of hydrochloric acid were determined by titration. The resul-ts ob-tained are indicated in Table 1 hereinafter.
EX~PEE 2 The -procedure was as in Example 1, sa~e that 20 ml o~ an aqueous solution of the meth~l-etherified trime-thylol-melamine was used. m e resulting stabilized red phosphorus contained 12.5 weight % of the melamine/
formaldehyde-resin. The data determined ~or the stabi-lit~ to oxidation o~ the red phosphorus to treated are indicated in Table 1 hereina~ter, EXAMPLE
-- .
The procedure was as in Example 1, save that 30 ml~
o~ an aqueous solution o~ methyl-etherified trimethylol-melamine was used. The resulting stabiliæed red phospho-rus contained 17.~ weight % of melamine/formaldehyde-1~9715Z
resin. The data determined for the stability to oxi-dation of the red phosphorus so treated are indicated in Table 1 hereinafter.
EXAMPLE I (Comparative Example) The procedu~e was as in Example 1~ save that no oxidation stabilizer was added to the red phosphorus.
m e data determined for -the stability to oxidation o~
red phosphorus are indicated in the ~ollowing Table 1.
T A B L E
Example A B
0~10 1~8 2 0~06 2~0 3 0~04 1~8
suspension, which is ~iltered, washed with hot water and dried under vacuum.
A still ~urther process ~or stabilizing red phos-phorus has been disclosed in U.S. Patent Specification 2 635 953, wherein aluminum hydroxide is used in com-bination with zinc or magnesium hydroxide~
The processes last described do equally not permit red phosphorus to be satisfactorily stabilized against ; oxidation with the use of a minimum of stabilizer.
1o The known oxidation stabilizers ha~e more speci-~ically an insufficient thermal stability and liberate water at higher temperatures, which is disadva~tageous.
In those cases in which plastics material rendered ~lame-retardant by means of recl phosphorus, which in turn has an oxidation stabilizer incorporated therein, are to be processed on an ex~ruder, it is an imperative re~uirement that the oxidation stabilizer combine in itsel~ thermal stability with non-liberation of water and undecomposability, e~en at temperatures higher than 300Co In accordance with our present invention, we have unexpectedly ~ound that red phosphorus can be satis-factorily stabilized by superficially covering the red phospho-rus particles with a hardened melamine-formaldehyde resin.
The present invention relates more particularly to stabilized pulverulent red phosphorus consistLng of particles with a size o~ at most about 2 mm and an oxi-dation stabilizer, whereLn the individual phosphorus particles are super~icially covered with a thin ~ilm _ 3 _ ~g~
of a polycondensation product of melamine and formalde-hyde as the oxidation stabilizer, the said polycondensa- ;
tion product being used in a proportion o~ about 1 to 20 weight %9 based on the quantity of red phosphorus.
In accordance with a preferred ~eature of the pre- ¦
sent invention9 the oxidation stabilizer is a partially etherified polycondensation product of melamine and formaldehyde.
A further pre~erred feature of the present inven-lo tlon provides for the individual phosphorus particles to be superficially covered with a thin film of the oxi-dation stabilizer which comprises a polycondensation p~oduct prepared by hardening a mononuclear, partially or completely methylolated melamine, whose methylol groups are unetherified or partially or completely etherified with at least one mono- or polyhydric ali-phatic C1-C6 alcohol; or by hardening a suitable poly-nuclear, partially or completely water miscible ~re liminary condensation product o~ melamine and form-aldehyde, the said preliminary condensation product containing melamine'and ~ormaldehyde in a molar ratio of 1:1 to 1:6 being unetherified or partially or com-pletely etherified w~th at least one mono- or polyhy-dric aliphatic C1-C6 alcohol; or by hardening a blend of the said unetheri~ied and/or etherified mononuclear methylolmelamines and/or unetherifîed or etherified polynuclear preliminary condensation products o~ mel-amine and formaldehyde; the polycondensation pr~duct being used in a proportion o~ about 1 to 20 weight %,.
based on the quantity of red phosphorus ~L~973l5Z
The oxidation stabilizers comprise more preferablya eOg. a polycondensation product prepared by hardening dimethylolmelamine, trimethylolmelamine, tetramethylol-melamine, pentamethylolmelamine, hexamethylolmelamine or a mixture thereo~; or a polycondensation product prepared by hardening a dimethylolmelamine, trimethylol-melamine, tetramethylolmelamine, pentamethylolmelamine or hexamethylolmelamine, of which the methylol groups are partially or completely e-therified with at least one mono- or polyhydric aliphatic C1-C6, preferably C1-C4 aliphatic alcohol. The mono- or polyhydric al-cohols which can be used in this invention may be saturated or unsaturated and have a carbon chain in-terrupted by one or more ether bridges. Suitable al-, cohols are, e,g~, the following: methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, n-pentanol, iso-pentanol, n-hexanol~ iso-hexanol, allyl alcohol, e-thylene glycol, propylene glycol or a butane diol, such as butane diol-1~4, a hexane diol, sucn as hexane diol-1,6, diethylene glycol, triethylene glycol, dipropylene glycol or glycerol, methanol being the pre-~erred aliphatic alcohol.
Commercially proven oxidation stabilizers com-prise those polycondensation products which are ob-tained by hardening a trimethylolmelamine-trimethyl-ether, hexamethylol-melamine-hexamethylether or penta-methylolmelamine-trimethylether.
A still further useful oxidation stabilizer is the ~ polycondensation product which is ob~ained by hardening a partially or completely water-miscible polynuclear - 5 ~
,. ' ~CI 97~SZ
preliminary condensation product of melamine and ~orm-aldehyde (briefly termed polynuclear methylolmelamine hereinafter) containing melamine and formaldehyde in a molar ratio of 1:1 to 1:~. The polynuclear preliminary condensation product of melamine and formaldehyde may be partially or completely etherified with the alcohols specified hereinabove. It is also possible for the mono-and polynuclear methylolmelamines to contain about 2 to 20 weight % of a modifying agent as commonly used in the aminoplast chemistry, the percentage being based on the mono- or polynuclear methylolmelamine. The modi-fying agents comprise9 ~or example~ sorbitol~ sugar,lac-tams, e.g, -caprolactam, methylene-bis-formamide, and toluene sulfonamides, e.g. paratoluene-sul~onamide.
With respect to the polycondensation product just described, it is pre~erable ~or it to be present in the stabilized pulverulent red phosphorus in a proportion o~ 2 to 10 weight %.
The present invention also relates to a process for making stabilized pulverulent red phosphorus con-sisting of particles with a size of at most about 2 mm and an oxidation stabilizer, which comprises: super-~icially wetting the indi~idual phosphorus particles by intimately blending them`with an aqueous about 1 to 95 weight % solution of a preliminary condensation product of melamine and formaldehyde; the preliminary condensation product being used in a proportion o~
about 1 to 20 weight %, based on the ~uantity of red phosphorus; hardening the preliminary condensation product; and drying the resulting stabilized red phos-.. . . . . .
phorus at elevated temperature.
Thus, for example, it is possible to use methyl-etherified trimethylolmelamine as the preliminary con-densation product, which is commercially available in the form of an about 75 weight % aqueous solution, It has a dynamic viscosity of L~50-600 centipoises at 20C, a pH of 8.2 to 9 2 at 20C, a density of 1.200 to 1.220 (g/ml) at 20C and a gelation period of 18 to 30 minutes at 20C in the presence of 0.2 weight % of para-toluenesulfonic acid.
A pre~erred version of the present process pro-vides for the individual phosphorus particles to be superficially wetted by intimately blending them with an aqueous, about 1 to ~5 weight ~ solution or suspen-t sion of a mononuclear, partially or completely methy-lolated melamine, whose methylol groups are unetheri-fied or partially or completel~ etherified with at least one mono- or polyhydric aliphatic C1-C6 alcohol;
or of a suitable polynuclear, partially or completely water-miscible preliminary condensation product o~
melamine and formaldehyde~ the said preliminary con-densation product containing melamine and formaldehyde in a molar ratio of 1:1 to 1:6 being unetherified or partially or comple-tely etherified with at least one mono- or polyhydric aliphatic C1-C6 alcohol; or o~
a blend of the said unetherified and/or etherified mononuclear methylolmelamines and/or unetherified or etherified polynuclear preliminary condensa-tion pro-duc-ts of melamine and formaldehyde; the said mono-or polynuclear methylolmelamine being used in a pro-'.
- 7 - ~
, , "~, `. : ~.
. .
~97~5Z
portion of about 1 to 20 weight %, based on the quan-tity of red phosphorus, hardening the mono- or poly-nuclear methylolmelamine, and drying the resulting sta-bilized red phosphorus at elevated temperature.
The individual phosphorus particles, which common ly have a size of 0.01 to 0.15 mm, may more pre~erably be wetted super~icially with the use of a 5 to 75 weight %
aqueous solution o~ one o~ the mono- or polynuclear9 etherified or unetherified methylolmelamines specified~
which should preferably be employed in a proportion of 2 to 10 weight ~/0, based on the quantity of red phos-phorus.
A ~urther preferred version of the present process provides ~or the individual phosphorus particles to be super~icially wetted with the use of an aqueous solu-tion or suspension of dimethylolmelamine~ trimethylol-melamine, tetramethylolmelamine, pentame-~hylolmelamine, hexamethylol~elamina or a mixture thereof, The methylol groups may be partially or completely -etherified with at least one mono- or polyhydric ali-phatic C1-C6, preferably C~-C4, aliphatic alcohol, e.g.
w-th metha~ol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, n-pentanol, iso-pentanol, n-hexa-nol, iso-hexanol, allyl alcohol, ethylene glycol, pro-` pylene glycol or a butane diol, such as butane diol-194,~
a hexane diol, such as hexane diol-1,6, diethylene gly-- col, triethylene glycol,jdipropylene glycol or glycerol.
I-t is particularly advantageous to super~lcially wet the individual phosphorus particles with a pbl~ondensation product of trimethylolmelamine trimethylether~ hexa-- :
~97~SZ
methylol hexamethylether or pentamethylol trimethyl-ether.
In wetting the phosphorus particles, it is possible to use the aqueous solution or suspension of the mono-or polynuclear methylolmelamine in admixture with about 2 ~to 20 weight % of a modifying agent as commonly used in the aminoplast chemistry7 the percentage being based on the mono- or polynuclear methylolmel~mine. The modi-~ying agents comprise, for example, sorbitol~ sugar9 lactams, : lo e.g. -caprolactamj methylene-bis-formamide, and toluene sulfonamides, e.g. para-toluene-sulfonamide.
The red phosphorus particles can more speci~ically be wetted, for example, as follows: ~n aqueous disper-sion of pulverulent red phosphorus is admixed with a predetermined quantity of an aqueous solution or sus-pension containing one or more of the mono- or polynuc-lear methylolmelami~es specified, and hardening is ini-tiated by acidifying and/or heating the aqueous disper-sion. After hardening, the aqueous dispersion is filtered the filter residue is water-washed and dried at a tem-perature, e.g. of 80 to 180C, if desired under reduced pressure.
The mono- or polynuclear methylolmelamines can also be hardened on the surface of the phosphorus par-ticles either by heat treatment at 100 to 180C or by acidifying the aqueous solution or suspension so as to establish a pH of ~ to 7. In those cases in which an aqueous solution o~ trimethylolmelamine trimethylether is employed, it i5 advantageous to e~fect the hardening at a pH of 3 to 5.
_ g _ ~97 ~SZ
The stabilized red phosphorus and ~he present pro-cess for making it compare favorably with the prior art products and methods inasmuch as the stabilizer is a thermally stable agent which is the firs-~ to permit the incorporation of stabilized red phosphorus into plastics material at temperatures higher than 250C.
The following Examples illustrate the invention.
E~AMPLE 1 150 ml of an aqueous phosphorus suspension which contained 100 g of pulverulent~red phosphorus, was diluted with 350 ml of water, the whole was admixed with 10 ml of an aqueous 75 weight ~ solution of a methyl-etherified trimethylol-melamine, and a pH of 3 was established by the addition of phosphoric acid ` of 5 % strength. ~he suspension was heated with àgi-ta-tlon to 90C, allowed to react for 30 minutes and filtered~ The filter residue was water-washed and dried at 100C in a s~ream of nitrog2n. The red phos-phorus so stabili~ed contained 7.5 weight ~ of melamine/
formaldehyde resin.
The red phosphorus so treated was tested for i-ts stability to oxidation. To this end, a three necked round flask provided with a tubular gas inlet, thermo-meter, reflux condenser and magnetic stirrer was charged with 450 ml of water and 1 g of red phosphorus, the mixture was heated to~80C and 10 lfh of oxygen was introduced thereinto with agîtation~ A gas mixture con-sisting of oxygen and hydrogen phosphide ~the latter, which was obtained together with acids o~ phosphorus of various oxidation stages, was formed by dispropor-- 10 - ~
:~97152 tionation of red phosphorus) le~t the reflux condenser.
It was delivered to two series-connected wash bottles-, which each contained 100 ml o~ a 5 weight % aqueous mercury(II) chloride solution~ The hydrogen phosphide underwent reaction with the mercury(II)chloride in accordance with the following equation:
PH3 ~ 3 HgCl2 - ~ P(HgCl)3 ~ 3 HCl The quantity of oxo acids o phosphorus present in the aqueous suspension of red phosphorus and the quan-tity of hydrochloric acid present in the gas washing bottles wers determined as an index of the stability to oxidation o~ red phosphorus. The content of phos-t~ phoric acid and the content of hydrochloric acid were determined by titration. The resul-ts ob-tained are indicated in Table 1 hereinafter.
EX~PEE 2 The -procedure was as in Example 1, sa~e that 20 ml o~ an aqueous solution of the meth~l-etherified trime-thylol-melamine was used. m e resulting stabilized red phosphorus contained 12.5 weight % of the melamine/
formaldehyde-resin. The data determined ~or the stabi-lit~ to oxidation o~ the red phosphorus to treated are indicated in Table 1 hereina~ter, EXAMPLE
-- .
The procedure was as in Example 1, save that 30 ml~
o~ an aqueous solution o~ methyl-etherified trimethylol-melamine was used. The resulting stabiliæed red phospho-rus contained 17.~ weight % of melamine/formaldehyde-1~9715Z
resin. The data determined for the stability to oxi-dation of the red phosphorus so treated are indicated in Table 1 hereinafter.
EXAMPLE I (Comparative Example) The procedu~e was as in Example 1~ save that no oxidation stabilizer was added to the red phosphorus.
m e data determined for -the stability to oxidation o~
red phosphorus are indicated in the ~ollowing Table 1.
T A B L E
Example A B
0~10 1~8 2 0~06 2~0 3 0~04 1~8
4 (comp.Example) 0.52 7.0 The data in column A o~ the above Table indicate the quantity of hydrogen phosphide ~mg PH~/g . h) which is evolved on subjectin~ the phosphorus spec~mens to oxidation.
The data in column B of the above Table relate to - the acidity of the aqueous phosphorus-containing sus-- pensions, which is caused by the formation of phosphoric acids on subjecting the red phosphorus to oxidation ~mg KOH/g . h)o The data indicated in columns A and B of the above Table 1 show that a good stabilizing effect is conferred ~o upon red phosphorus by treatment with the melamine-form-aldehyderesins of this invention.
200 ml of an aqueous phosphorus suspension which contained about 100 g of pulverulent red phosphorus, was diluted with 300 ml of water, admixed with 5 g of un- -etherified melamine/formaldehyde-condensation product, in which the molar ratio o~ melamine to formaldehyde was 1:2.6, and a pH value of 3 was established by the addi-tion of phosphoric acid of 5 % strength. Tlle suspension was heated with agitation to 90C, allowed to react for -'1 hour, and filtered. The filter residue was water-washed and dried at 100C in a stream of nitrogen. The red phos-phorus so stabili~ed contained 5.6 weight % of melamine/
formaldehyde-resin.
The data determined ~or the stability to oxidation of the red phosphorus so treated are indicated in Table 2 hereinafter.
The procedure was as in Exam~le 5, but 10 g ol an unetherified melamine/formal~ehyde-conden3ation product, which contained melamine and formaldehyde in a molar ratio of 1:2.6, was used. The resultin~ stabilized red phosphorus contained11.8 weight % of mel~nine/formalde-hyde-resin.
The data determined for the stability to oxidation of the red phosphorus so treated are indicated in Table 2 hereinafter.
The procedure was as in Example 5 9 but 7 g of an aqueous 9 about 75 weight % solution of trimethylolmel~
amine trimethylether was used. The red phosphorus so - 13 ~
~097~152 s-tabilized contained 6.7 weight % of melamine/formalde-hyde-resin.
The data determined ~or the stability to oxidation of the red phosphorus so treated are indicated in Table 2 hereina~ter. ;~
EX~MPLE 8 The procedure was as in Example 5, but 15 g of an aqueous, about 75 weight y solution o~ trimethylolmelamine trimethylether was used. The red phosphorus so stabili- -zed contained 13.3 weight yO of melamine/~ormaldehyde-resin, The data determined for the stability to oxidation of the red phosphorus so treated are indicated in Table 2 hereinafter.
EXAMPLE 9 : -The procedure was as in Example 5, but 5 g o~ hexa-methylolmelamine hexamethylether was used and the reac-tion period was prolonged to 24 hours. ~he red phos-phorus so stabilized contained 6,1 weight % o~ melamine/
formaldehyde-resin.
The data determined for the stability to oxidation o~ the red phosphorus so treated are indicated in Table 2 hereinafter.
EXA~LE 10 The procedure was as in Exam~le 5, but 10 g of hexamethylolmelamine hexamethylether wa~ used and the reaction period was prolonged to 24 hours. The red phosphorus so stabilized contained 11.6 weight %
of melamine/formaldehyde-resin.
The data ¦determined for the stability to oxidation . ,~, : , . ' . .,.. ~............ ;
1097~Si2 o~ the red phosphorus so treated are indicated in Table 2 hereinafter.
The procedure was as in Example 5, but 5 g of pentamethylolmelamine-trimethylether was used. The red phosphorus so stabilized contained 5.8 weight % o~ -melamine/formaldehyde-resin.
The data determined ~or the stability to oxidation of the red phosphorus so treated are indicated in Table 2 hereinafter, EXAMP~E 12 The procedure was as in Example 5, but 10 g o~
pentamethylol-melamine trimethylether was usedO The red phosphorus so stabilized cc)ntained 10.5 weight %
, o~ melamine/formaldehyde-resin~ -The data determined for the stability to oxidation of the red phosphorus so treated are indîca-ted in Table 2 hereinafter.
- EX~PLE 13 (Com~arative Example~
_ _ The procedure was as in Example 5, but no oxida-tion s-tabilizer was added to the red phosphorus.
The data de-termined for the stability to oxidation o~ the red phosphorus so trea~ed are indicated in the following Table 2.
-. ~.
. . , ' . ' ' . ,. :' ~ ~.
71S~
; T A B L E II
Example A B
0.15 2.1 6 0.13 2.1 i 7 0.13 1.9 8 0.09 1.6 9 0.12 2.2 0~05 1~7 11 0.12 1.8 12 0.08 1.6 13 0.52 7.0 .
The data in column A of the above Table 2 indLcate the ~uantity o~ hydrogen phosphide tmg PH3~g . h) which is evolved on sub~ecting the phosphorus specimens to oxi-; dation.
The data in column B o~ the above Table 2 relate t~
the acidity of the aqueous phosphorus-containing sus-pensions, which is caused by the formation o~ phosphoric acids on subjecting the red phosphorus to oxidation (mg KOH/g . h). :
The data indicated in columns A and B of the above Table 2 show that a good stabilizing effect is co~ferred upon red phosphorus by treatment with the melamine/form- :
aldehyde resins of the present inventionO ;
. ;
- ~
- . ,
The data in column B of the above Table relate to - the acidity of the aqueous phosphorus-containing sus-- pensions, which is caused by the formation of phosphoric acids on subjecting the red phosphorus to oxidation ~mg KOH/g . h)o The data indicated in columns A and B of the above Table 1 show that a good stabilizing effect is conferred ~o upon red phosphorus by treatment with the melamine-form-aldehyderesins of this invention.
200 ml of an aqueous phosphorus suspension which contained about 100 g of pulverulent red phosphorus, was diluted with 300 ml of water, admixed with 5 g of un- -etherified melamine/formaldehyde-condensation product, in which the molar ratio o~ melamine to formaldehyde was 1:2.6, and a pH value of 3 was established by the addi-tion of phosphoric acid of 5 % strength. Tlle suspension was heated with agitation to 90C, allowed to react for -'1 hour, and filtered. The filter residue was water-washed and dried at 100C in a stream of nitrogen. The red phos-phorus so stabili~ed contained 5.6 weight % of melamine/
formaldehyde-resin.
The data determined ~or the stability to oxidation of the red phosphorus so treated are indicated in Table 2 hereinafter.
The procedure was as in Exam~le 5, but 10 g ol an unetherified melamine/formal~ehyde-conden3ation product, which contained melamine and formaldehyde in a molar ratio of 1:2.6, was used. The resultin~ stabilized red phosphorus contained11.8 weight % of mel~nine/formalde-hyde-resin.
The data determined for the stability to oxidation of the red phosphorus so treated are indicated in Table 2 hereinafter.
The procedure was as in Example 5 9 but 7 g of an aqueous 9 about 75 weight % solution of trimethylolmel~
amine trimethylether was used. The red phosphorus so - 13 ~
~097~152 s-tabilized contained 6.7 weight % of melamine/formalde-hyde-resin.
The data determined ~or the stability to oxidation of the red phosphorus so treated are indicated in Table 2 hereina~ter. ;~
EX~MPLE 8 The procedure was as in Example 5, but 15 g of an aqueous, about 75 weight y solution o~ trimethylolmelamine trimethylether was used. The red phosphorus so stabili- -zed contained 13.3 weight yO of melamine/~ormaldehyde-resin, The data determined for the stability to oxidation of the red phosphorus so treated are indicated in Table 2 hereinafter.
EXAMPLE 9 : -The procedure was as in Example 5, but 5 g o~ hexa-methylolmelamine hexamethylether was used and the reac-tion period was prolonged to 24 hours. ~he red phos-phorus so stabilized contained 6,1 weight % o~ melamine/
formaldehyde-resin.
The data determined for the stability to oxidation o~ the red phosphorus so treated are indicated in Table 2 hereinafter.
EXA~LE 10 The procedure was as in Exam~le 5, but 10 g of hexamethylolmelamine hexamethylether wa~ used and the reaction period was prolonged to 24 hours. The red phosphorus so stabilized contained 11.6 weight %
of melamine/formaldehyde-resin.
The data ¦determined for the stability to oxidation . ,~, : , . ' . .,.. ~............ ;
1097~Si2 o~ the red phosphorus so treated are indicated in Table 2 hereinafter.
The procedure was as in Example 5, but 5 g of pentamethylolmelamine-trimethylether was used. The red phosphorus so stabilized contained 5.8 weight % o~ -melamine/formaldehyde-resin.
The data determined ~or the stability to oxidation of the red phosphorus so treated are indicated in Table 2 hereinafter, EXAMP~E 12 The procedure was as in Example 5, but 10 g o~
pentamethylol-melamine trimethylether was usedO The red phosphorus so stabilized cc)ntained 10.5 weight %
, o~ melamine/formaldehyde-resin~ -The data determined for the stability to oxidation of the red phosphorus so treated are indîca-ted in Table 2 hereinafter.
- EX~PLE 13 (Com~arative Example~
_ _ The procedure was as in Example 5, but no oxida-tion s-tabilizer was added to the red phosphorus.
The data de-termined for the stability to oxidation o~ the red phosphorus so trea~ed are indicated in the following Table 2.
-. ~.
. . , ' . ' ' . ,. :' ~ ~.
71S~
; T A B L E II
Example A B
0.15 2.1 6 0.13 2.1 i 7 0.13 1.9 8 0.09 1.6 9 0.12 2.2 0~05 1~7 11 0.12 1.8 12 0.08 1.6 13 0.52 7.0 .
The data in column A of the above Table 2 indLcate the ~uantity o~ hydrogen phosphide tmg PH3~g . h) which is evolved on sub~ecting the phosphorus specimens to oxi-; dation.
The data in column B o~ the above Table 2 relate t~
the acidity of the aqueous phosphorus-containing sus-pensions, which is caused by the formation o~ phosphoric acids on subjecting the red phosphorus to oxidation (mg KOH/g . h). :
The data indicated in columns A and B of the above Table 2 show that a good stabilizing effect is co~ferred upon red phosphorus by treatment with the melamine/form- :
aldehyde resins of the present inventionO ;
. ;
- ~
- . ,
Claims (26)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Stabilized pulverulent red phosphorus consisting of par-ticles with a size of at most about 2 mm and an oxidation stabilizer, wherein the individual phosphorus particles are superficially covered with a thin hardened film of a polycondensation product of melamine and formaldehyde as the oxidation stabilizer, the said polycondensation product being used in a proportion of about 1 to 20 weight %, based on the quantity of red phosphorus.
2. Red phosphorus as claimed in claim 1, wherein the oxida-tion stabilizer is a polycondensation product of methyl-etherified trimethylolmelamine.
3. Red phosphorus as claimed in claim 1, wherein the in-dividual phosphorus particles are superficially covered with a thin film of the oxidation stabilizer, which is a polycondensation product prepared by hardening a mononuclear, partially or complete-ly methylolated melamine, whose methylol groups are unetherified or partially or completely etherified with at least one mono- or polyhydric aliphatic C1-C6 alcohol; or by hardening a suitable polynuclear, partially or completely water-miscible preliminary condensation product of melamine and formaldehyde, the said pre-liminary condensation product containing melamine and formaldehyde in a molar ratio of 1:1 to 1:6 being unetherified or partially or completely etherified with at least one mono- or polyhydric aliphatic C1-C6 alcohol; or by hardening a blend of the said unetherified and/or etherified mononuclear methylol-melamines and/or unetherified or etherified polynu-clear preliminary condensation products of melamine and formaldehyde; the polycondensation product being used in a proportion of about 1 to 20 weight %, based on the quantity of red phosphorus.
4. Red phosphorus as claimed in claim 3, wherein the polycondensation product is prepared by hardening dimethylolmelamine, trimethylolmelamine, tetramethylol-melamine, pentamethylolmelamine, hexamethylolmelamine or a mixture thereof.
5. Red phosphorus as claimed in claim 3, wherein the polycondensation product is prepared by hardening the partially or completely methylolated melamine, of which the methylol groups are partially or com-pletely etherified with at least one mono- or polyhydric aliphatic C1-C4 alcohol.
6. Red phosphorus as claimed in claim 3, wherein the aliphatic alcohol is methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, n-pentanol, iso-pentanol, n-hexanol, iso-hexanol, allyl alcohol, ethylene glycol, propylene glycol, butane diol-1,4, hexane diol-1,6, diethylene glycol, triethylene glycol, dipropylene glycol or glycerol.
7. Red phosphorus as claimed in claim 3, wherein the polycondensation product is prepared by hardening trimethylolmelamine-trimethylether, hexamethylol-melamine-hexamethylether or pentamethylolmelamine-trimethylether.
8. Red phosphorus as claimed in claim 1, containing the polycondensation product in a proportion of 2 to 10 weight %, based on the quantity of red phosphorus.
9. In a process for making stabilized, pulverulent red phosphorus consisting of particles with a size of at most about 2 mm and an oxidation stabilizer the improvement which comprises: superficially wetting the individual phosphorus particles by intimately blending them with an aqueous, about 1 to 95 weight % solution of a preliminary con-densation product of melamine and formaldehyde, the preliminary condensation product being used in a proportion of about 1 to 20 weight %, based on the quantity of red phosphorus; hardening the pre-liminary condensation product; and drying the re-sulting stabilized red phosphorus at elevated tem-perature.
10. The process as claimed in claim 9, wherein the re-sulting stabilized red phosphorus contains 2 to 10 weight % of the preliminary condensation product, based on the quantity of red phosphorus.
11. The process as claimed in claim 9, wherein the pre-liminary condensation product is a methyl-etherified trimethylolmelamine.
12. The process as claimed in claim 9, wherein the in-dividual phosphorus particles are superficially wetted by intimately blending them with an aqueous, about 1 to 95 weight % solution or suspension of a mononuclear, partially or completely methylolated melamine, whose methylol groups are unetherified or partially or com-pletely etherified with at least one mono- or poly-hydric aliphatic C1-C6 alcohol; or of a suitable polynuclear, partially or completely watermiscible preliminary condensation product of melamine and formaldehyde, the said preliminary condensation pro-duct containing melamine and formaldehyde in a molar ratio of 1:1 to 1:6 being unetherified or partially or completely etherified with at least one mono- or polyhdric aliphatic C1-C6 alcohol; or of a blend of the said unetherified and/or etherified mononuclear methylolmelamines and/or unetherified or etherified polynuclear preliminary condensation products of melamine and formaldehyde; the said mono- or polynu-clear melamine being used in a proportion of about 1 to 20 weight %, based on the quantity of red phosphorus; hardening the mono- or polynuclear melamine, and drying the resulting sta-bilized red phosphorus at elevated temperature.
13. The process as claimed in claim 12, wherein the in-dividual phosphorus particles are superficially wetted with a 5 to 75 weight % aqueous solution or suspension of the mono- or polynuclear methylolmel-amine.
14. The process as claimed in claim 12, wherein the mono-or polynuclear methylolmelamine is used in a pro-portion of 2 to 10 weight %, based on the quantity of red phosphorus.
15. The process as claimed in claim 12, wherein the in-dividual phosphorus particles are superficially wetted with an aqueous solution or suspension of dimethylo-melamine, trimethylolmelamine, tetramethylolmelamine, pentamethylolmelamine, hexamethylolmelamine or a mixture thereof.
16. The process as claimed in claim 12, wherein the methylol groups of the methylolated melamine are partially or completely etherified with at least one mono- or polyhydric aliphatic C1-C4 alcohol.
17. The process as claimed in claim 12, wherein the aliphatic alcohol is methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, n-pentanol, iso-pentanol,n-hexanol, iso-hexanol, allyl alcohol, ethylene glycol, propylene glycol, butane diol-1,4, hexane diol-1,6, diethylene glycol, triethylene glycol, dipropylene glycol or glycerol.
18. The process as claimed in claim 12, wherein the in-dividual phosphorus particles are superficially wetted with an aqueous solution or suspension of trimethylol-melamine trimethylether, hexamethylolmelamine hexa-methylether or pentamethylolmelamine trimethylether.
19. The process as claimed in claim 12, wherein the mono-or polynuclear methylolmelamine applied to the sur-face of the individual phosphorus particles is hardened at a temperature of 100 to 180°C.
20. The process as claimed in claim 12, wherein the mono-or polynuclear methylolmelamine applied to the sur-face of the individual phosphorus particles is hardened at a pH value of 3 to 7 of the aqueous solution or suspension.
21. The process as claimed in claim 9, wherein the stabilized red phosphorus is dried at a temperature of 80 to 180°C.
22. The process as claimed in claim 9, wherein the stabilized red phosphorus is dried under reduced pressure.
23. The process as claimed in claim 9, wherein the red phosphorus particles have a size of 0.01 to 0.15 mm.
24. The process as claimed in claim 12, wherein, in the event of the oxidation stabilizer used being an aqueous solution of trimethylolmelamine trimethyl-ether, the hardening is effected at a pH of 3 to 5.
25. The process as claimed in claim 12, wherein the aqueous solution or suspension of the mono- or polynuclear methylolmelamine used for wetting the individual phosphorus particles is used in com-bination with about 2 to 20 weight %, based on the quantity of mono- or polynuclear methylolmelamine, of a modifying agent as commonly employed in the aminoplast chemistry.
26. The process as claimed in claim 25, wherein the aqueous solution or suspension used for wetting the individual phosphorus particles contains sorbitol, sugar, ?-caprolactam, methylene-bis-formamide or para-toluene sulfonamide.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP2655739.1 | 1976-12-09 | ||
| DE2655739A DE2655739C2 (en) | 1976-12-09 | 1976-12-09 | Stabilized red phosphorus and process for its manufacture |
| DE19772705042 DE2705042A1 (en) | 1977-02-08 | 1977-02-08 | STABILIZED RED PHOSPHORUS AND THE METHOD OF MANUFACTURING IT |
| DEP2705042.6 | 1977-02-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1097152A true CA1097152A (en) | 1981-03-10 |
Family
ID=25771229
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA292,173A Expired CA1097152A (en) | 1976-12-09 | 1977-12-01 | Stabilized red phosphorus and process for making it |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS5375317A (en) |
| CA (1) | CA1097152A (en) |
| DD (1) | DD133141A5 (en) |
| GB (1) | GB1545716A (en) |
| IN (1) | IN147048B (en) |
| IT (1) | IT1092166B (en) |
| SE (1) | SE416541B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4489183A (en) * | 1983-12-13 | 1984-12-18 | Erco Industries Limited | Stabilization of red phosphorus |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1134333B (en) * | 1980-11-19 | 1986-08-13 | F F A Spa Sa | PROCESS TO STABILIZE THE RED PHOSPHORUS BY ENCAPSULATION FOR USE AS A FLAME RETARDANT OF POLYMERIC MATERIALS AND PRODUCT SO OBTAINED |
| IT1137409B (en) | 1981-03-05 | 1986-09-10 | Saffa Spa | SELF-EXTINGUISHING PAPER MATERIALS |
| CA1196437A (en) * | 1981-12-19 | 1985-11-05 | Kazushi Hirobe | Flame resistant resin composition |
| GB8326053D0 (en) * | 1983-09-29 | 1983-11-02 | Bryant & May Ltd | Striking composition and surface for safety matches |
| DE3710170A1 (en) * | 1987-03-27 | 1988-10-13 | Hoechst Ag | STABILIZED RED PHOSPHORUS AND METHOD FOR THE PRODUCTION THEREOF |
| CN110330000A (en) * | 2019-04-01 | 2019-10-15 | 复旦大学 | A kind of preparation method of nanometer of red phosphorus |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51105996A (en) * | 1975-03-14 | 1976-09-20 | Phosphorus Chem Ind | Sekirinno kaishitsuhoho |
-
1977
- 1977-12-01 CA CA292,173A patent/CA1097152A/en not_active Expired
- 1977-12-03 IN IN1685/CAL/77A patent/IN147048B/en unknown
- 1977-12-06 IT IT52080/77A patent/IT1092166B/en active
- 1977-12-06 GB GB50719/77A patent/GB1545716A/en not_active Expired
- 1977-12-07 DD DD7700202451A patent/DD133141A5/en unknown
- 1977-12-08 SE SE7713951A patent/SE416541B/en not_active IP Right Cessation
- 1977-12-09 JP JP14870877A patent/JPS5375317A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4489183A (en) * | 1983-12-13 | 1984-12-18 | Erco Industries Limited | Stabilization of red phosphorus |
Also Published As
| Publication number | Publication date |
|---|---|
| DD133141A5 (en) | 1978-12-13 |
| IN147048B (en) | 1979-10-27 |
| SE7713951L (en) | 1978-06-10 |
| JPS5375317A (en) | 1978-07-04 |
| IT1092166B (en) | 1985-07-06 |
| GB1545716A (en) | 1979-05-16 |
| SE416541B (en) | 1981-01-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2759077B2 (en) | Stable powdered red phosphorus and its production method | |
| CA1097152A (en) | Stabilized red phosphorus and process for making it | |
| CA1128292A (en) | Stabilized red phosphorus and process for its manufacture | |
| JPH0453998B2 (en) | ||
| KR930008114B1 (en) | Method for the preparation of hydrolysis-stable finely divided flame retardants based on ammonium polyphos phate | |
| US4029513A (en) | Surface treated silica | |
| JPH0386715A (en) | Manufacture of water-soluble resole resin | |
| JPH021717A (en) | New method for manufacture of aminoplast resin evolving very little formalin | |
| ES2240309T3 (en) | STABILIZED RED PHOSPHORY AND A PROCEDURE FOR PREPARATION. | |
| CA1206284A (en) | Fire-retardant treatment composition | |
| CA1171634A (en) | Process for making long-chain ammonium polyphosphate | |
| US3449068A (en) | Process for the manufacture of polyphosphates | |
| US4505849A (en) | Polyol pre-mixture for making flame-retardant poly-urethane foam plastics | |
| US4113841A (en) | Stabilized red phosphorus and process for making it | |
| US4423764A (en) | Binder for preparing improved cores and molds | |
| CA1075439A (en) | Stabilized red phosphorus and process for making it | |
| US2211918A (en) | Calcium phosphate product | |
| US3457199A (en) | Improved urea-formaldehyde foams | |
| Jacob et al. | Composition of citrate-insoluble residues from superphosphates and ammoniated superphosphates | |
| DE2705042A1 (en) | STABILIZED RED PHOSPHORUS AND THE METHOD OF MANUFACTURING IT | |
| JPH01203418A (en) | Curing of aminoplastic resin | |
| KR0156365B1 (en) | Process for producing ammonium polyphosphate of crystalline form ñœ | |
| JPS61126091A (en) | Production of polyphosphoric acid aminotriazine compound | |
| JP2904839B2 (en) | Stabilized red phosphorus and method for producing the same | |
| US3787561A (en) | Loosely aggregated 100 millimicron micellular silica |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |