CA1216856A - Liquid diphenylmethane diisocyanate compositions - Google Patents
Liquid diphenylmethane diisocyanate compositionsInfo
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- CA1216856A CA1216856A CA000469635A CA469635A CA1216856A CA 1216856 A CA1216856 A CA 1216856A CA 000469635 A CA000469635 A CA 000469635A CA 469635 A CA469635 A CA 469635A CA 1216856 A CA1216856 A CA 1216856A
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Abstract
LIQUID DIPHENYLMETHANE DIISOCYANATE COMPOSITIONS
ABSTRACT OF THE DISCLOSURE
The invention is directed to a process for the production of an isocyanate which is both stable and liquid at room temperature comprising reacting an iso-cyanate selected from the group consisting of (a) a diphenylmethane diisocyanate containing from 25 to 70 percent, by weight, of the 4,4'-isomer, from 30 to 75 percent, by weight, of the 2,4'-isomer and from 0 to 10 percent, by weight, of the 2,2'-isomer, and (b) crude diphenylmethane diisocyanate, with a diol selected from the group consisting of 1-methyl-1,3-propane diol, 2,2-dimethyl-1,3-propane diol, 1,4-dimethyl-1,4-diethyl-1,4-butane diol and 3-methyl-1,5-pentane diol, at a temperature of from 20 to 110°C, in a ratio such that the resultant product has an isocyanate group content of from 20 to 30%, by weight.
ABSTRACT OF THE DISCLOSURE
The invention is directed to a process for the production of an isocyanate which is both stable and liquid at room temperature comprising reacting an iso-cyanate selected from the group consisting of (a) a diphenylmethane diisocyanate containing from 25 to 70 percent, by weight, of the 4,4'-isomer, from 30 to 75 percent, by weight, of the 2,4'-isomer and from 0 to 10 percent, by weight, of the 2,2'-isomer, and (b) crude diphenylmethane diisocyanate, with a diol selected from the group consisting of 1-methyl-1,3-propane diol, 2,2-dimethyl-1,3-propane diol, 1,4-dimethyl-1,4-diethyl-1,4-butane diol and 3-methyl-1,5-pentane diol, at a temperature of from 20 to 110°C, in a ratio such that the resultant product has an isocyanate group content of from 20 to 30%, by weight.
Description
Mo-2537 LIQUID DIPHENYLMETHANE DIISOCYANATE COMPOSITIONS
This invention reIates to organic isocyanates and mixtures of organic isocyanates based on diphenyl-methane diisocyanates whic~i'are liquid at room tempera-ture. The invention also relates to a process forpreparing these isocyanates.
BACKGROUND OF THE IN~ENTION
Diisocyanates which'are liquid at room tempera-ture have numerous advantages over solid diisocyanates.
Diisocyanates which are liquid at room temperature, such as toluene diisocyanate or hexamethylene diisocyanate, are, as a rule, physiologically harmful because of their high vapor pressure. For this reason, various attempts have been made to start with diisocyanates that are solid at room temperature and convert these into the`
liquid form~
The most commercially important diisocyanates which are solid at room temperature are 4,4'-diphenyl-methane diisocyanate and the 2,4'-isomer thereof, which melt at 39C and 34.5C, respectively.
Numerous patents have issued relating to the liquification of diphenylmethane diisocyanate. See, for e~ample,,U.S. Patents 3,152,162; 3,384,653; 3,394,165;
3,449,256; 3,640,966; 3,641,0,93; 3,644,457; 3,674,8,28;
3,701,796; 3,883,571; 4,014,935; 4,055,548; 4,0,88,665;
~,031,026; 4,102,833; 4,115,429; 4,118,411; 4,154,752;
4,177,205; 4,229,347; 4,261,852; 4,321,333; and 4,332,742.
It is an object of this invention ~o provide ' improved organic isocyanates which are liquid at room temperature. A further object of this invention is to provide organic isocyanates which'remain liquid even on prolonged storage'at low temperatures. Still another object of this invention is to provide an Mo-2537 ~i ~
~Z~ G
improved process for preparing liquid organic isocya-nates.
DESCRIPTION OF THE INVENTION
The instant invention is directed to a process for preparing liquid modified isocyanates comprising reacting an isocyanate selected from the group consist-ing of (a) a diphenylmethane diisocyanate containing from 25 to 70 percent by weight of the 4,4'-isomer, from 30 to 75 percent by weight of the 2,~'-isomer and from o to 10 percent by weight of the 2,2'-isomer, and (b) crude diphenylmethane diisocyanate, with a diol selected from the group consisting of l-methyl-1,3-propane diol,
This invention reIates to organic isocyanates and mixtures of organic isocyanates based on diphenyl-methane diisocyanates whic~i'are liquid at room tempera-ture. The invention also relates to a process forpreparing these isocyanates.
BACKGROUND OF THE IN~ENTION
Diisocyanates which'are liquid at room tempera-ture have numerous advantages over solid diisocyanates.
Diisocyanates which are liquid at room temperature, such as toluene diisocyanate or hexamethylene diisocyanate, are, as a rule, physiologically harmful because of their high vapor pressure. For this reason, various attempts have been made to start with diisocyanates that are solid at room temperature and convert these into the`
liquid form~
The most commercially important diisocyanates which are solid at room temperature are 4,4'-diphenyl-methane diisocyanate and the 2,4'-isomer thereof, which melt at 39C and 34.5C, respectively.
Numerous patents have issued relating to the liquification of diphenylmethane diisocyanate. See, for e~ample,,U.S. Patents 3,152,162; 3,384,653; 3,394,165;
3,449,256; 3,640,966; 3,641,0,93; 3,644,457; 3,674,8,28;
3,701,796; 3,883,571; 4,014,935; 4,055,548; 4,0,88,665;
~,031,026; 4,102,833; 4,115,429; 4,118,411; 4,154,752;
4,177,205; 4,229,347; 4,261,852; 4,321,333; and 4,332,742.
It is an object of this invention ~o provide ' improved organic isocyanates which are liquid at room temperature. A further object of this invention is to provide organic isocyanates which'remain liquid even on prolonged storage'at low temperatures. Still another object of this invention is to provide an Mo-2537 ~i ~
~Z~ G
improved process for preparing liquid organic isocya-nates.
DESCRIPTION OF THE INVENTION
The instant invention is directed to a process for preparing liquid modified isocyanates comprising reacting an isocyanate selected from the group consist-ing of (a) a diphenylmethane diisocyanate containing from 25 to 70 percent by weight of the 4,4'-isomer, from 30 to 75 percent by weight of the 2,~'-isomer and from o to 10 percent by weight of the 2,2'-isomer, and (b) crude diphenylmethane diisocyanate, with a diol selected from the group consisting of l-methyl-1,3-propane diol,
2,2-dimethyl-1,3-propane diol, 1,4-dimethyl-1,4-diethyl-1,4-butane diol and 3-methyl-1,5-pentane diol, at a temperature between about 20 and about 110C, pre~er-ably between 40 and 80C, and most preferably between 50 and 70C, in a ratio such that the product has an isocyanate group content of from 20 to 30 percent, by weight, and preferably of from 22 to 26 percent, by weight. In general, the weight ratio of isocyanate to diol will be from 5:1 to 15:1 and preferably from 7:1 to 14:1. The liquid modified isocyanate may also be prepared as a concentrate (that is, with a lower per-cent lsocyanate group content) and diluted with addi-tional isocyanate to adjust the isocyanate content to the desired level. The instant invention is also directed to isocyanates which are both stable and liquid at room temperature, prepared according to the above- -noted process.
As used herein, the phrase "crude diphenyl-methane diisocyanate" means an isocyanate mixture which is either (i) a phosgenation product of an undistilled bottom fraction of the type formed during the removal of from 5 to 95%, by weight, of diphenylmethane diamine Mo-2537 ~2~
from an aniline/formaldehyde condensate, or (ii) an undistilled bottom fraction of the type obtained during the removal of from 5 to 95%, by weight, of diphenyl-methane diisocyanate from the crude phosgenation product of an aniline/formaldehyde condensate, wherein the isocyanate mixture (a) contains from 25 to 95%, by weight, of diphenylmethane diisocyanate, of which from 1 to 60%, by weight, is the 2,4'-isomer and from 0 to 10%, by weight, is the 2,2'-isomer and the balance is the 4,4'-isomer, (b) has a viscosity of from 10 to 600 cps at 50C, and (c) has an isocyanate group content of from about 28 to about 33%, by weight.
The liquid isocyanates which can be preparedaccording to the invention have a very low viscosity and can therefore be processed very easily, such as by casting or metering through pumps. ~dditionally, they have a very low vapor pressure and are, therefore, less physiologically harmful.
In general, the process may be carried out by introducing the diol into the isocyanate at temperatures from 20 to 110C, with stirring. The isocyanate content of the product of the process amounts to from 20 to 30 percent, by weight, and preferably to from 22 to 26 percent by weight.
The product of the present invention can be used for many different polyaddition reactions in the lacquer and plastics industry. For example, they may be used in the production of polyurethane foams and elastomers, such as in reaction injection molding (RIM) products.
The invention is further illustrated, but is not intended to be limited by the following examples in which all parts and percentages are by weight unless otherwise specified.
Mo-2537 ~2~6~3S~
EXAMPLES
Example 1 (Comparison) 104 parts by weight of 2,2-dimetnyl-1,3-propane diol were added over a period of 30 minutes to 12~7 parts by weight of diphenylmethane diisocyanate containing 98 percent, by weight, of the 4,4'-isomer and 2 percent, by weight, of the 2,4'-isomer, which had been heated to 50C. After the reacticn mixture was stirred for three hours at 60-65C, a solid product resulted, which had an isocyanate group content of 24.4%.
Example 2 104 parts by weight of 2,2-dimethyl-1,3-propane diol were added over a period of 30 minutes to 1200 parts by weight of diphenylmethane diisocyanate con-taining 65 percent, by weight`, of the 4, 4'-isomer, 34 percent, by weight, of the 2,4 '-isomer, and 1 percent by weight, of the 2,2'-isomer, which had been heated to 50C. After the reaction mixture was stirred for three hours at 60-65C, a liquid, stable product resulted, which had an isocyanate group content of 24.5% and a viscosity of 620 cps at 25C.
Example 3 104 parts by weight of 2,2-dimet~yl-1,3-propane diol were added over a period of about 10 minutes, to 1207 parts by weight o diphenylmethane diisocyanate containing 35 percent, by weight, of ~he 4,4l-isomer, 64 percent, by weight, of the 2,4'-isomer, and 1 per-cent,by weight, of the 2,2'-isomer, which had baen heated to 30C. After thè reaction mixture was stirred for two hours, at 75-80C, a liquid, stable product resulted which had an isocyanate group content of 24.1% and a viscosity of ~70 cps at 25C.
Mo-2537 ~2~ i6 Exampl~e 4 (Comparison) 90 parts by we:i'ght o~ 1-me-thyl-1,3-propane diol were added over a period of 30'minutes to 1,200 parts by weight of diphenylmet'hane 'diisocyanate containiny 98 percent, by weight, of the 4,4'-isomer, and 2 percent, by weight, of the 2,4'-isomer, whi'ch had been heaked to 50C. After the reaction mixture was heated for 3 hours at 60-65C,.a solid product res'ulted, which had an NCO-content o~ 24.6~.
Example 5 90 parts by weight of 1-methyl-1,3-propane diol were added over a period of 30 minutes to 1200 parts by weight of diphenylmethane diisocyanate containing 70 percent by weight of the 4,.4'-isomer, and 30.percent by weight of the '2,4'-isomer, which'had been heated to 50C. After the reaction mixture was heated for 3 hours at 60-65C, a liquid, stable product resulted, which had an NC0-content of 24.6~ and a viscosity of 540 cps at 25C.
Example 6 90 parts by weight of l-methyl-1,3-propane diol were added over a period of 10 minutes to 1200 parts by weight o~ diphenylmethane diisocyanate containing 65 pexcent by weight of the'4',4'-isomer, and 35 percent by weight of the 2,4'-isomer, which 'had been heated to 45C. After the reaction mixture was heated for 2 hours at 75-80C, a liquid, stable product resulted, which had an NCO-content of 24..5% and a viscosity of 510.cps at Example 7 90 parts by weight of l-methyl-1,3-propane diol were added over a pexiod of 10 minutes to 1200 parts by weight o~ diphenylmet'hane 'diisocyanate containing 35 percent by weight of the. 4,4'-isomer, and 65 percent ~y weight of the 2,4'-isomer, which had been heated to 30C.
Mo-2537 ~6~
-6- ,-After the reaction mixture was heated for 2 hours at 85-90C, a liquid, stable product resulted, which had an NCO-content of 24~6% and a viscosity of 640 cps at Example 8 (Comparison~
118 parts by weight of 3-methyl-1,5 pentane diol were added over a p~riod of 30 minutes to 1250 parts by weight of diphenylmethane diisocyanate contain-ing 98 percent by weight of the 4,4'-isomer, and 2 per-cent by weigh~ of the 2,4'-isomer, which had been heated to 50C. Ater the reaction mixture was heated for 3 hours at 60-65C, a solid product resulted, which had an NCO-content of 24.3%.
E~ample 9 118 parts by weight of 3-methyl-1,5-pentane diol were added over a period of 30 minutes to 1250 parts by weight diphenylmethane diisocyanate containing 35 percent by weight of the 4,4'-isomer, and 65 percent by weight of the 2,4'-isomer, which had been heated to 50C. After the reaction mixture was heated for 2 hours at 75-80C, a li~uid, stable product resulted, which had an NCO-content of 24.1~ and a viscosity of 700 cps at 25C.
Example lO.(Comparison) : 25 174 parts by weight of 1,4 dimethyl-1,4-diethyl-1,4-butane diol were added over a period of 30 minutes to 1200.parts by weight of diphenylmethane diisocyanate containing 98 percent by weight of the 4/4'-isomer/ and 2 percent by weight of the 2,4i-isomer, which had been 30 heated to 50C. After the reaction mixture was heated for 3 hours at 60-65C, a solid product resulted, which had an NC0 content of 23.1~.
Example 11 174.parts by weight of 1,4-dimethyl-1,4-diethyl-35 1,4-butane diol were added over a period o~ 10 minutes Mo-2537 ~ Z~6856;
to 1200 p~rts by weight of diphenylmethane dîisocyanate containing 35 per:cent by weight of the 4,4'~isomer, and 65 percent by weight o the 2,4'.-isomer, which had been heated to 50C. After the reaction mixture was heated or 2 hours at 75-80C, a liquid, stable product resulted, whi'ch'had an NCO-content o 23.4% and a vis-cosity of 800.cps at 25C.
Example '12 104 parts by weight of 2,2-dimethyl 1,3-propanediol were added over a period of 10 minutes to1560 parts by weight of "crude diphenylmethane diisocya-nate" (NCO content of 33O4% and a viscosity of 15 cps at 5~C) containing 95 percent diphenylmethane diisocya-nate, of which 44.% is the 4,.4'-isomer, 55% is the 2,.4'-isomer, and 1% is the'2,2'-isomer, which has bben heated to 50C. After the reaction mixture was stirred for
As used herein, the phrase "crude diphenyl-methane diisocyanate" means an isocyanate mixture which is either (i) a phosgenation product of an undistilled bottom fraction of the type formed during the removal of from 5 to 95%, by weight, of diphenylmethane diamine Mo-2537 ~2~
from an aniline/formaldehyde condensate, or (ii) an undistilled bottom fraction of the type obtained during the removal of from 5 to 95%, by weight, of diphenyl-methane diisocyanate from the crude phosgenation product of an aniline/formaldehyde condensate, wherein the isocyanate mixture (a) contains from 25 to 95%, by weight, of diphenylmethane diisocyanate, of which from 1 to 60%, by weight, is the 2,4'-isomer and from 0 to 10%, by weight, is the 2,2'-isomer and the balance is the 4,4'-isomer, (b) has a viscosity of from 10 to 600 cps at 50C, and (c) has an isocyanate group content of from about 28 to about 33%, by weight.
The liquid isocyanates which can be preparedaccording to the invention have a very low viscosity and can therefore be processed very easily, such as by casting or metering through pumps. ~dditionally, they have a very low vapor pressure and are, therefore, less physiologically harmful.
In general, the process may be carried out by introducing the diol into the isocyanate at temperatures from 20 to 110C, with stirring. The isocyanate content of the product of the process amounts to from 20 to 30 percent, by weight, and preferably to from 22 to 26 percent by weight.
The product of the present invention can be used for many different polyaddition reactions in the lacquer and plastics industry. For example, they may be used in the production of polyurethane foams and elastomers, such as in reaction injection molding (RIM) products.
The invention is further illustrated, but is not intended to be limited by the following examples in which all parts and percentages are by weight unless otherwise specified.
Mo-2537 ~2~6~3S~
EXAMPLES
Example 1 (Comparison) 104 parts by weight of 2,2-dimetnyl-1,3-propane diol were added over a period of 30 minutes to 12~7 parts by weight of diphenylmethane diisocyanate containing 98 percent, by weight, of the 4,4'-isomer and 2 percent, by weight, of the 2,4'-isomer, which had been heated to 50C. After the reacticn mixture was stirred for three hours at 60-65C, a solid product resulted, which had an isocyanate group content of 24.4%.
Example 2 104 parts by weight of 2,2-dimethyl-1,3-propane diol were added over a period of 30 minutes to 1200 parts by weight of diphenylmethane diisocyanate con-taining 65 percent, by weight`, of the 4, 4'-isomer, 34 percent, by weight, of the 2,4 '-isomer, and 1 percent by weight, of the 2,2'-isomer, which had been heated to 50C. After the reaction mixture was stirred for three hours at 60-65C, a liquid, stable product resulted, which had an isocyanate group content of 24.5% and a viscosity of 620 cps at 25C.
Example 3 104 parts by weight of 2,2-dimet~yl-1,3-propane diol were added over a period of about 10 minutes, to 1207 parts by weight o diphenylmethane diisocyanate containing 35 percent, by weight, of ~he 4,4l-isomer, 64 percent, by weight, of the 2,4'-isomer, and 1 per-cent,by weight, of the 2,2'-isomer, which had baen heated to 30C. After thè reaction mixture was stirred for two hours, at 75-80C, a liquid, stable product resulted which had an isocyanate group content of 24.1% and a viscosity of ~70 cps at 25C.
Mo-2537 ~2~ i6 Exampl~e 4 (Comparison) 90 parts by we:i'ght o~ 1-me-thyl-1,3-propane diol were added over a period of 30'minutes to 1,200 parts by weight of diphenylmet'hane 'diisocyanate containiny 98 percent, by weight, of the 4,4'-isomer, and 2 percent, by weight, of the 2,4'-isomer, whi'ch had been heaked to 50C. After the reaction mixture was heated for 3 hours at 60-65C,.a solid product res'ulted, which had an NCO-content o~ 24.6~.
Example 5 90 parts by weight of 1-methyl-1,3-propane diol were added over a period of 30 minutes to 1200 parts by weight of diphenylmethane diisocyanate containing 70 percent by weight of the 4,.4'-isomer, and 30.percent by weight of the '2,4'-isomer, which'had been heated to 50C. After the reaction mixture was heated for 3 hours at 60-65C, a liquid, stable product resulted, which had an NC0-content of 24.6~ and a viscosity of 540 cps at 25C.
Example 6 90 parts by weight of l-methyl-1,3-propane diol were added over a period of 10 minutes to 1200 parts by weight o~ diphenylmethane diisocyanate containing 65 pexcent by weight of the'4',4'-isomer, and 35 percent by weight of the 2,4'-isomer, which 'had been heated to 45C. After the reaction mixture was heated for 2 hours at 75-80C, a liquid, stable product resulted, which had an NCO-content of 24..5% and a viscosity of 510.cps at Example 7 90 parts by weight of l-methyl-1,3-propane diol were added over a pexiod of 10 minutes to 1200 parts by weight o~ diphenylmet'hane 'diisocyanate containing 35 percent by weight of the. 4,4'-isomer, and 65 percent ~y weight of the 2,4'-isomer, which had been heated to 30C.
Mo-2537 ~6~
-6- ,-After the reaction mixture was heated for 2 hours at 85-90C, a liquid, stable product resulted, which had an NCO-content of 24~6% and a viscosity of 640 cps at Example 8 (Comparison~
118 parts by weight of 3-methyl-1,5 pentane diol were added over a p~riod of 30 minutes to 1250 parts by weight of diphenylmethane diisocyanate contain-ing 98 percent by weight of the 4,4'-isomer, and 2 per-cent by weigh~ of the 2,4'-isomer, which had been heated to 50C. Ater the reaction mixture was heated for 3 hours at 60-65C, a solid product resulted, which had an NCO-content of 24.3%.
E~ample 9 118 parts by weight of 3-methyl-1,5-pentane diol were added over a period of 30 minutes to 1250 parts by weight diphenylmethane diisocyanate containing 35 percent by weight of the 4,4'-isomer, and 65 percent by weight of the 2,4'-isomer, which had been heated to 50C. After the reaction mixture was heated for 2 hours at 75-80C, a li~uid, stable product resulted, which had an NCO-content of 24.1~ and a viscosity of 700 cps at 25C.
Example lO.(Comparison) : 25 174 parts by weight of 1,4 dimethyl-1,4-diethyl-1,4-butane diol were added over a period of 30 minutes to 1200.parts by weight of diphenylmethane diisocyanate containing 98 percent by weight of the 4/4'-isomer/ and 2 percent by weight of the 2,4i-isomer, which had been 30 heated to 50C. After the reaction mixture was heated for 3 hours at 60-65C, a solid product resulted, which had an NC0 content of 23.1~.
Example 11 174.parts by weight of 1,4-dimethyl-1,4-diethyl-35 1,4-butane diol were added over a period o~ 10 minutes Mo-2537 ~ Z~6856;
to 1200 p~rts by weight of diphenylmethane dîisocyanate containing 35 per:cent by weight of the 4,4'~isomer, and 65 percent by weight o the 2,4'.-isomer, which had been heated to 50C. After the reaction mixture was heated or 2 hours at 75-80C, a liquid, stable product resulted, whi'ch'had an NCO-content o 23.4% and a vis-cosity of 800.cps at 25C.
Example '12 104 parts by weight of 2,2-dimethyl 1,3-propanediol were added over a period of 10 minutes to1560 parts by weight of "crude diphenylmethane diisocya-nate" (NCO content of 33O4% and a viscosity of 15 cps at 5~C) containing 95 percent diphenylmethane diisocya-nate, of which 44.% is the 4,.4'-isomer, 55% is the 2,.4'-isomer, and 1% is the'2,2'-isomer, which has bben heated to 50C. After the reaction mixture was stirred for
3 hours at 65-70C, a liquid, stable product resulted, which had an NCO-content of 26.0% and a viscosity of 350 cps at 25C.
Example 13 104 parts by weight of 2,2-dimethyl-1,3 propane diol were added over a period of 10 minutes to 1560 parts by weight of "crude diphenylmethane diisocya-nate" (NCO content of 32.:6% and a viscosity of 35 cps at 50C) containin~ 75 percent, by weight, of diphenyl-methane diisocyanate, of which''97% is the 4,4'-isomer, and 3~ is the 2,4'-isomer, which has been heated to 50C. After the reaction mixture was stirred for 3 hours at .60-65C, a liquid, stable product resulted, which'had an NCO content of 25.4% and a viscosity of 2900 cps at 25C.
~o-2537.
Example 14 90 parts by weight of 1-methyl-1,3-propane diol were added over a period of 30 minutes to 1350 parts by wPight of "crude diphbnylmet'hane diisvcyanate"' (NCO-content of 33.4% and a viscosity o~ 15 cps at 50C~
containing 95 percent diphenylmethane diisocyanate, of which 44~ is the ~,4'-isomer, 55~ is the 2,4'-isomer, and 1~ is the 2,2'-isomer, which'has been heated to 50C.
After the reaction mixture was stirred for 3 houxs at 60-65C, a li~uid, stable product resulted, which had an NCO-content of 25.0% and a viscosity of 660 cps at 2SC.
Example lS
90 parts by weight .of l-methyl-1,3.-propane diol were added over a period of lO' minutes to 1350 parts by weight of "crude diphenylmethane diisocyanate" (NCO-content of 32.8% and a viscosity of 25 cps at 50C), containing 80 percent diphenylmethane diisocyanate, of which 94% is the 4,4'-isomer, and 6~ is the 2,4l-isomer, which has been heated to 50C.. After the reaction mix-ture was stirred for 3 hours at 60-65C, a liquid, stable product resulted, which had an NCO content of 24.6% and a viscosity of 1500. cps at .25C.
.. 25 Although'the 'invention has been described in detail in the foregoing for the `purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made .therein by those skilled in the art without departing from the 3~ spirit and scope'of the`invention except as it may be .
limited by the claims.
Mo-2537
Example 13 104 parts by weight of 2,2-dimethyl-1,3 propane diol were added over a period of 10 minutes to 1560 parts by weight of "crude diphenylmethane diisocya-nate" (NCO content of 32.:6% and a viscosity of 35 cps at 50C) containin~ 75 percent, by weight, of diphenyl-methane diisocyanate, of which''97% is the 4,4'-isomer, and 3~ is the 2,4'-isomer, which has been heated to 50C. After the reaction mixture was stirred for 3 hours at .60-65C, a liquid, stable product resulted, which'had an NCO content of 25.4% and a viscosity of 2900 cps at 25C.
~o-2537.
Example 14 90 parts by weight of 1-methyl-1,3-propane diol were added over a period of 30 minutes to 1350 parts by wPight of "crude diphbnylmet'hane diisvcyanate"' (NCO-content of 33.4% and a viscosity o~ 15 cps at 50C~
containing 95 percent diphenylmethane diisocyanate, of which 44~ is the ~,4'-isomer, 55~ is the 2,4'-isomer, and 1~ is the 2,2'-isomer, which'has been heated to 50C.
After the reaction mixture was stirred for 3 houxs at 60-65C, a li~uid, stable product resulted, which had an NCO-content of 25.0% and a viscosity of 660 cps at 2SC.
Example lS
90 parts by weight .of l-methyl-1,3.-propane diol were added over a period of lO' minutes to 1350 parts by weight of "crude diphenylmethane diisocyanate" (NCO-content of 32.8% and a viscosity of 25 cps at 50C), containing 80 percent diphenylmethane diisocyanate, of which 94% is the 4,4'-isomer, and 6~ is the 2,4l-isomer, which has been heated to 50C.. After the reaction mix-ture was stirred for 3 hours at 60-65C, a liquid, stable product resulted, which had an NCO content of 24.6% and a viscosity of 1500. cps at .25C.
.. 25 Although'the 'invention has been described in detail in the foregoing for the `purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made .therein by those skilled in the art without departing from the 3~ spirit and scope'of the`invention except as it may be .
limited by the claims.
Mo-2537
Claims (7)
1. A process for the production of an isocya-nate which is both stable and liquid at room tempera-ture comprising reacting an isocyanate selected from the group consisting of (a) a diphenylmethane diisocyanate containing from 25 to 70 percent, by weight, of the 4,4'-isomer, from 30 to 75 percent, by weight, of the 2,4'-isomer and from 0 to 10 percent, by weight, of the 2,2'-isomer, and (b) crude diphenylmethane diisocyanate, with a diol selected from the group consisting of 1-methyl-1,3-propane diol, 2,2-dimethyl-1,3-propane diol, 1,4-dimethyl-1,4-diethyl-1 r 4-butane diol and 3-methyl-1,5-pentane diol, at a temperature of from 20 to 110°C, in a ratio such that the resultant product has an iso-cyanate group content of from 20 to 30%, by weight.
2. The process of Claim 1, wherein the temperature is from 40 to 80°C.
3. The process of Claim 2, wherein the temperature is from 50 to 70°C.
4. The process of Claim 1, wherein the weight ratio of isocyanate to diol is from 5:1 to 15:1.
5. The process of Claim 1, wherein the product has an isocyanate group content of from 22 to 26 per-cent by weight.
6. An isocyanate prepared by reacting an isocyanate selected from the group consisting of (a) a diphenylmethane diisocyanate containing from 25 to 70 percent, by weight, of the 4,4'-isomer, from 30 to 75 percent, by weight, of the 2,4'-isomer and from 0 to 10 pexcent, by weight, of the 2,2'-isomer, and (b) crude diphenylmethane diisocyanate, with a diol selected from the group consisting of l-methyl-1,3-propane diol, 2,2-dimethyl-1,3-propanediol, 1,4-dimethyl-1,4-diethyl-1,4-butane diol and 3-methyl-1,5-pentane diol, at a temperature of from 20 to 110°C, in a ratio such that the resultant product has an isocyanate group content of from 20 to 30%, by weight.
7. The product of Claim 6 having an isocyanate group content of from 22 to 26 percent, by weight.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US56580983A | 1983-12-27 | 1983-12-27 | |
| US565,809 | 1990-08-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1216856A true CA1216856A (en) | 1987-01-20 |
Family
ID=24260189
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000469635A Expired CA1216856A (en) | 1983-12-27 | 1984-12-07 | Liquid diphenylmethane diisocyanate compositions |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1216856A (en) |
-
1984
- 1984-12-07 CA CA000469635A patent/CA1216856A/en not_active Expired
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