CA2056784A1 - Process for removing cured rigid polyurethane foams from substrates - Google Patents
Process for removing cured rigid polyurethane foams from substratesInfo
- Publication number
- CA2056784A1 CA2056784A1 CA 2056784 CA2056784A CA2056784A1 CA 2056784 A1 CA2056784 A1 CA 2056784A1 CA 2056784 CA2056784 CA 2056784 CA 2056784 A CA2056784 A CA 2056784A CA 2056784 A1 CA2056784 A1 CA 2056784A1
- Authority
- CA
- Canada
- Prior art keywords
- polyurethane foam
- alkylene carbonate
- rigid polyurethane
- carbonate
- solvent
- 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.)
- Abandoned
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Abstract
Abstract (D# 80,967-F) A process for the dissolution of cured rigid polyurethane foams is disclosed. A cured rigid polyurethane foam may be dissolved, or removed from a substrate, by contacting the rigid polyurethane foam with a mixture comprising (1) an alkylene carbonate and (2) at least one non-alkylene carbonate co-solvent in which said cured rigid polyurethane foam is at least partially soluble.
Description
( D# 80,967-F
RRS
A PROCESS FOR REMOVING CURED RIGID POLYURETHANE FOAMS
FROM SUBSTRATES
(D# 80,~67_F) Cross-Reference to_~lated Application This application is related to co-pending U. S. Patent Application Serial No. 07/610,635, filed November 8, 1990.
Background of the Invention Field of the Invention The invention relates to solvents for loosening or removing cured rigid polyurethane foams from tools, processing equipment and other substrates.
Description of Related Methods A variety of solvents have been used to clean processing equipment, metal parts and tools after a rigid polyurethane foam has cured on them. Some of the solvents used include such compounds as dimethyl formamide, 1,1,1-trichloroethans, methylene chloride, chlorofluorocarbons, toluene, xylene, acetone, methyl ethyl ketone, ethylene glycol ethers, tetrahydrofuran, and ~-butyrolactone. However, though these compounds are effective solvents, the use of each presents a hazard or complication of one type or another. For example, the chlorine-containing compounds are now thought to contribute to ozone depletion in the atmosphere.
The other solvents are either toxic, suspected carcinogens, or very volatile, and thus present health and safety problems. An alternative solvent, n-methyl pyrrolidinone, is more easily handled and presents fewer environmental problems, but is expensive. Thus, ^i 7 ~ ,~
it would be a substantial improvement in the art if a relatively inexpensive yet effective solvent formulation were available to remove cured rigid polyurethane foams, and that did not present the environmental, health and safety problems of the prior art solvent formulations.
Applicant has discovered, surprisingly, that cured rigid polyurethane foam may be removed from a substrate by contacting the rigid polyurethane foam with a co-solvent system comprising an alkylene carbonate and one or more other solvents. The present inventive process, by substituting alkylene carbonate for a portion of the more hazardous prior art solvents, reduces many of the health, safety and environmental hazards associated with the prior art solvents, and is economically attractive as well.
Summary of the Invention The invention concerns, in a process for removing a cured rigid polyurethane foam from a substrate by contacting said rigid polyurethane foam with a solvent in which said cured rigid polyurethane foam is at least partially soluble, the improvement comprising diluting said solvent with a co-solvent comprising alkylene carbonate. In another of its aspects, the invention concerns a process for removing cured rigid polyurethane foam from a substrate, comprising contacting a cured rigid polyurethane foam with a co-solvent system comprising a mixture of alkylene carbonate and at least one non-alkylene carbonate solvent selected from the group consisting of aromatic hydrocarbons, alcohols, ketones, esters, ethers, glycol ethers, imidazoles, and ureas. The .
invention also concerns a proces9 for dissolving cured rigid polyurethane foam, comprising contacting a cured rigid polyurethane foam with a co-solvent system comprising a mixture of (1) an alkylene carbonate selected from the group consisting of ethylene carbonate, propylene carbonate, and 1,2-butylene carbonate and (2) at least one non-alkylene carbonate solvent in which said rigid polyurethane foam is at least partially soluble, selected from the group consisting of aromatic hydrocarbons, alcohols, ketones, esters, ethers, glycol ethers, imidazoles, and ureas.
Descri~tion of the Preferred Embodiments Alkylene carbonates useful in the present invention may be represented by the following formula:
O
R R
where R is H or an alkyl group containing from 1 to about 20 carbon atoms. It is preferred that R be H or a methyl group, i.e. that the alkylene carbonate be ethylene carbonate, propylene carbonate, or 1,2-butylene carbonate. Diethyl carbonate is another preferred alkylene carbonate.~Ethylene carbonate and propylene carbonate are commercially available from Texaco Chemical Co. as Texacar~ EC
Ethylene Carbonate and Texacar~ PC Propylene Carbonate, respectively. Alternatively, a mixture of alkylene carbonates may J ~ 3 be used. A mixture of ethylene carbonate and propylene carbonate is commercially available as Texacar EC-50.
Solvents that may be diluted by alkylene carbonates in the present invention include, but are not limited to, solvents selected from the group consisting of aromatic hydrocarbons, alcohols, ketones, esters, ethers, glycol ethers, imidazoles, and ureas. For example, Applicant has demonstrated the removal of rigid polyurethane foams from substrates using co-solvent formulations containing an alkylene carbonate and one or more of the following solvents: 2-ethyl-1-hexanol, ethylene glycol diacetate, 2-ethylhexyl acetate, N-methyl pyrrolidinone, tetrahydrofurfuryl alcohol, ethylene glycol butyl ether acetate, tetramethyl urea, diethylene glycol butyl ether, ethylene glycol butyl ether, methyl iso-amyl ketone, diethylene glycol methyl ether, dipropylene glycol methyl ether, dibasic ester, methyl isobutyl ketone, 1,2-dimethyl imidazole, N,N'-dimethyl ethylene urea, propylene glycol methyl ether, cyclohexanone, diacetone alcohol, furfuryl alcohol, and isobutyl isobutyrate. Pref~rably, the non-alkylene carbonate solvent is selected from the group consisting of 2-ethyl-1-hexanol, 2-ethylhexyl acetate, N-methyl pyrrolidinone, tetrahydrofurfuryl alcohol, ethylene glycol butyl ether acetate, tetramethyl,urea, diethylene glycol butyl ether, ethylene glycol butyl ether, methyl iso-amyl ketone, diethylene glycol methyl ether, dipropylene glycol methyl ether, methyl isobutyl ketone, 1,2-dimethyl imidazole, N,N'-dimethyl ethylene urea, propylene glycol methyl ether, cyclohexanone, diacetone ~ 3 alcohol, furfuryl alcohol, dimethyl ~ormamide, and isobutyl isobutyrate. More preferably, the non-alkylene carbonate solvent is selected from the group consisting of 2-ethyl-1-hexanol, N-methyl pyrrolidinone, tetramethyl urea, 1,2-dimethyl imidazole, N,N'-dimethyl ethylene urea, furfuryl alcohol, tetrahydrofurfuryl alcohol, propylene glycol methyl ether, ethylene glycol butyl ether acetate, and dimethyl formamide. Optionally, other solvents may be added to the formulations of the present invention as well.
Preferably, the portion of conventional solvent replaced with alkylene carbonate in a formulation containing one or more conventional (non-alkylene carbonate) solvents will be such that the alkylene carbonate and the conventional solvents in the formulation are present in a weight ratio of alkylene carbonate to total conventional solvent of about 4:1 to about 1:4. It is more preferred that the alkylene carbonate and the conventional solvents in the formulation be present in a weight ratio of alkylene carbonate to total convéntional solvent of about 1:2 to about 1:3.
One skilled in the art may find other weight ratios to be optimum and not depart from the scope of the present invention. Those skilled in the art will appreciate that the portion of conventional solvent(s) in a formulation which should be replaced with alkylene carbonate for a given rigid polyurethane foam involves a balance of possible reduction in dissolution power versus the reduction or avoidance of additional expense and/or environmental, health and safety risks associated with the conventional solvents. Applicant ~ 3i)~ s has demonstrated the use o~ several different formulations in the examples that follow.
Optionally, other additives may be employed in the formulations of the present invention. For example, suitable thickeners may be included, such as ethylcellulose, hydroxypropyl cellulose, organic modified clay, hydrogenated castor oil, and the like. Surfactants, to enhance the water washability of the substrate, may be included as well. Suitable surfactants include potassium oleate, the dioctyl ester of sodium sulfosuccinic acid, sodium alkylnaphthalene sulfonate, sodium alkylbenzene sulfonate, and the like.
Applicant's inventive process is effective at temperatures of from about room temperature to about 100 C and at pressures of from about atmospheric to several hundred psi.
Optionally, the process of the present invention may be performed at an elevated temperature. While Applicant's invention works well at room temperature, more effective dissolution may be obtained by heating the alkylene carbonate-containing formulation to a temperature of about 50 to about 100 C. The alkylene carbonate-containing formulation may be applied to the rigid polyurethane foam in any conventional manner. Typically, the rigid polyurethane foam-coated substrate will be placed in a vat or sonic bath containing the alkylene carbonate-containing formulation.
Alternatively, the alkylene carbonate-containing formulation could be applied to the foam-coated substrate by brush or spray. The period of time for which the alkylene carbonate-containing formulation should be permitted to work undisturbed on the rigid polyurethane foam to be removed will vary. After said period of time, agitation of the surfaces to be cleaned of the foam via wiping, brushing or scraping is preferred.
Rigid polyurethane foam formulations are well known in the art and are commercially available. Rigid foams are more highly cross-linked than either elastomers or flexible foams.
Other characteristics generally true of rigid polyurethane foams include (1) a structure having a high percentage of closed cells;
RRS
A PROCESS FOR REMOVING CURED RIGID POLYURETHANE FOAMS
FROM SUBSTRATES
(D# 80,~67_F) Cross-Reference to_~lated Application This application is related to co-pending U. S. Patent Application Serial No. 07/610,635, filed November 8, 1990.
Background of the Invention Field of the Invention The invention relates to solvents for loosening or removing cured rigid polyurethane foams from tools, processing equipment and other substrates.
Description of Related Methods A variety of solvents have been used to clean processing equipment, metal parts and tools after a rigid polyurethane foam has cured on them. Some of the solvents used include such compounds as dimethyl formamide, 1,1,1-trichloroethans, methylene chloride, chlorofluorocarbons, toluene, xylene, acetone, methyl ethyl ketone, ethylene glycol ethers, tetrahydrofuran, and ~-butyrolactone. However, though these compounds are effective solvents, the use of each presents a hazard or complication of one type or another. For example, the chlorine-containing compounds are now thought to contribute to ozone depletion in the atmosphere.
The other solvents are either toxic, suspected carcinogens, or very volatile, and thus present health and safety problems. An alternative solvent, n-methyl pyrrolidinone, is more easily handled and presents fewer environmental problems, but is expensive. Thus, ^i 7 ~ ,~
it would be a substantial improvement in the art if a relatively inexpensive yet effective solvent formulation were available to remove cured rigid polyurethane foams, and that did not present the environmental, health and safety problems of the prior art solvent formulations.
Applicant has discovered, surprisingly, that cured rigid polyurethane foam may be removed from a substrate by contacting the rigid polyurethane foam with a co-solvent system comprising an alkylene carbonate and one or more other solvents. The present inventive process, by substituting alkylene carbonate for a portion of the more hazardous prior art solvents, reduces many of the health, safety and environmental hazards associated with the prior art solvents, and is economically attractive as well.
Summary of the Invention The invention concerns, in a process for removing a cured rigid polyurethane foam from a substrate by contacting said rigid polyurethane foam with a solvent in which said cured rigid polyurethane foam is at least partially soluble, the improvement comprising diluting said solvent with a co-solvent comprising alkylene carbonate. In another of its aspects, the invention concerns a process for removing cured rigid polyurethane foam from a substrate, comprising contacting a cured rigid polyurethane foam with a co-solvent system comprising a mixture of alkylene carbonate and at least one non-alkylene carbonate solvent selected from the group consisting of aromatic hydrocarbons, alcohols, ketones, esters, ethers, glycol ethers, imidazoles, and ureas. The .
invention also concerns a proces9 for dissolving cured rigid polyurethane foam, comprising contacting a cured rigid polyurethane foam with a co-solvent system comprising a mixture of (1) an alkylene carbonate selected from the group consisting of ethylene carbonate, propylene carbonate, and 1,2-butylene carbonate and (2) at least one non-alkylene carbonate solvent in which said rigid polyurethane foam is at least partially soluble, selected from the group consisting of aromatic hydrocarbons, alcohols, ketones, esters, ethers, glycol ethers, imidazoles, and ureas.
Descri~tion of the Preferred Embodiments Alkylene carbonates useful in the present invention may be represented by the following formula:
O
R R
where R is H or an alkyl group containing from 1 to about 20 carbon atoms. It is preferred that R be H or a methyl group, i.e. that the alkylene carbonate be ethylene carbonate, propylene carbonate, or 1,2-butylene carbonate. Diethyl carbonate is another preferred alkylene carbonate.~Ethylene carbonate and propylene carbonate are commercially available from Texaco Chemical Co. as Texacar~ EC
Ethylene Carbonate and Texacar~ PC Propylene Carbonate, respectively. Alternatively, a mixture of alkylene carbonates may J ~ 3 be used. A mixture of ethylene carbonate and propylene carbonate is commercially available as Texacar EC-50.
Solvents that may be diluted by alkylene carbonates in the present invention include, but are not limited to, solvents selected from the group consisting of aromatic hydrocarbons, alcohols, ketones, esters, ethers, glycol ethers, imidazoles, and ureas. For example, Applicant has demonstrated the removal of rigid polyurethane foams from substrates using co-solvent formulations containing an alkylene carbonate and one or more of the following solvents: 2-ethyl-1-hexanol, ethylene glycol diacetate, 2-ethylhexyl acetate, N-methyl pyrrolidinone, tetrahydrofurfuryl alcohol, ethylene glycol butyl ether acetate, tetramethyl urea, diethylene glycol butyl ether, ethylene glycol butyl ether, methyl iso-amyl ketone, diethylene glycol methyl ether, dipropylene glycol methyl ether, dibasic ester, methyl isobutyl ketone, 1,2-dimethyl imidazole, N,N'-dimethyl ethylene urea, propylene glycol methyl ether, cyclohexanone, diacetone alcohol, furfuryl alcohol, and isobutyl isobutyrate. Pref~rably, the non-alkylene carbonate solvent is selected from the group consisting of 2-ethyl-1-hexanol, 2-ethylhexyl acetate, N-methyl pyrrolidinone, tetrahydrofurfuryl alcohol, ethylene glycol butyl ether acetate, tetramethyl,urea, diethylene glycol butyl ether, ethylene glycol butyl ether, methyl iso-amyl ketone, diethylene glycol methyl ether, dipropylene glycol methyl ether, methyl isobutyl ketone, 1,2-dimethyl imidazole, N,N'-dimethyl ethylene urea, propylene glycol methyl ether, cyclohexanone, diacetone ~ 3 alcohol, furfuryl alcohol, dimethyl ~ormamide, and isobutyl isobutyrate. More preferably, the non-alkylene carbonate solvent is selected from the group consisting of 2-ethyl-1-hexanol, N-methyl pyrrolidinone, tetramethyl urea, 1,2-dimethyl imidazole, N,N'-dimethyl ethylene urea, furfuryl alcohol, tetrahydrofurfuryl alcohol, propylene glycol methyl ether, ethylene glycol butyl ether acetate, and dimethyl formamide. Optionally, other solvents may be added to the formulations of the present invention as well.
Preferably, the portion of conventional solvent replaced with alkylene carbonate in a formulation containing one or more conventional (non-alkylene carbonate) solvents will be such that the alkylene carbonate and the conventional solvents in the formulation are present in a weight ratio of alkylene carbonate to total conventional solvent of about 4:1 to about 1:4. It is more preferred that the alkylene carbonate and the conventional solvents in the formulation be present in a weight ratio of alkylene carbonate to total convéntional solvent of about 1:2 to about 1:3.
One skilled in the art may find other weight ratios to be optimum and not depart from the scope of the present invention. Those skilled in the art will appreciate that the portion of conventional solvent(s) in a formulation which should be replaced with alkylene carbonate for a given rigid polyurethane foam involves a balance of possible reduction in dissolution power versus the reduction or avoidance of additional expense and/or environmental, health and safety risks associated with the conventional solvents. Applicant ~ 3i)~ s has demonstrated the use o~ several different formulations in the examples that follow.
Optionally, other additives may be employed in the formulations of the present invention. For example, suitable thickeners may be included, such as ethylcellulose, hydroxypropyl cellulose, organic modified clay, hydrogenated castor oil, and the like. Surfactants, to enhance the water washability of the substrate, may be included as well. Suitable surfactants include potassium oleate, the dioctyl ester of sodium sulfosuccinic acid, sodium alkylnaphthalene sulfonate, sodium alkylbenzene sulfonate, and the like.
Applicant's inventive process is effective at temperatures of from about room temperature to about 100 C and at pressures of from about atmospheric to several hundred psi.
Optionally, the process of the present invention may be performed at an elevated temperature. While Applicant's invention works well at room temperature, more effective dissolution may be obtained by heating the alkylene carbonate-containing formulation to a temperature of about 50 to about 100 C. The alkylene carbonate-containing formulation may be applied to the rigid polyurethane foam in any conventional manner. Typically, the rigid polyurethane foam-coated substrate will be placed in a vat or sonic bath containing the alkylene carbonate-containing formulation.
Alternatively, the alkylene carbonate-containing formulation could be applied to the foam-coated substrate by brush or spray. The period of time for which the alkylene carbonate-containing formulation should be permitted to work undisturbed on the rigid polyurethane foam to be removed will vary. After said period of time, agitation of the surfaces to be cleaned of the foam via wiping, brushing or scraping is preferred.
Rigid polyurethane foam formulations are well known in the art and are commercially available. Rigid foams are more highly cross-linked than either elastomers or flexible foams.
Other characteristics generally true of rigid polyurethane foams include (1) a structure having a high percentage of closed cells;
(2) low thermal conductivity; (3) nonreversible deformability;
(4) good load-bearing ability; and (5) high dimensional stability.
Generally, rigid polyurethane foams are based on polyols having a molecular weight less than 1000, and more often from about 400 to about 800. Rigid polyurethane foams are usually based on a polyol having a functionality of 2 to 8, and more typically from about 4 to about 8.
The invention will be further illustrated by the following examples, which are given by way of illustration and not as limitations on the scope of this invention.
Examples In the examples recorded in the table below, the following procedure was used. Previously coated stainless steel 3/4" screw stock rods were wire brushed and cleaned with a solvent.
Rods that had been coated with cured fiberglass were treated with acetone to remove any fiberglass residue; those that had been coated with cured flexible or rigid polyurethane foam were treated with methylene chloride. The rods were then sand blasted with micro beads. The rods were then coated with a polyether-based foam formulation having the following components:
Component Parts bv Weiaht Thanol~ R-350-X 36.9 DC-1931 tsilicon surfactant) 0.5 Rll (trichlorofluoromethane) 15.0 TEXACAT~ TD-33 0.3 Rubinate M2 (polymeric isocyanate) 49.6 lDow Corning; 2ICI.
The coatings were then allowed to cure for two days or more before dissolution studies were begun. Each coated stock rod was then suspended in a beaker from a ring stand. Each beaker contained one of the alkylene carbonate-containing formulations to be tested. At the bottom of each beaker was a stirring bar. After from about 16 to about 22 hours at room temperature the rods were observed and the approximate percentage of rigid polyurethane foam removed by each formulation was estimated and recorded.
3 i~
~ _ ,.___ __= ~.. _ Ex No Co-Solvent Systcm Components Weight Ratlo d Appro~mate % Rigid Components Foam Removed .___ 1 PC/2-ethyl-1-hexanol/EGDA 45/90/45 All foam removed 2 PC¦2-ethyl-1-hexanol/EGDA 45/45/90 10 %
._ 3 PC/2-elhyl-l hexanol/2-ethylhoxyl 60/60/60 All toam removed 4 PC/2-ethyl-1-hexanol/lBlB 60/60/60 All toam temoved PC/2-ethyl-1-hexanol/DB 60/60/60 70 %
6 PC/2-ethyl-1-hexanol/DM 60/60/60 60 %
7 PC/2-ethyl-1-hexanol/DPM 60/60/60 50 %
8 PC/2-ethyl-1-hexanol!Cyclohexanone 60/60/60 50 %
9 PC/2-ethyl-1-hexanol/DBe 45/45/90 10 %
PC/NMP 100/100 99 %
11 NMP ALL All foam removed .
12 PC/NNDMEU 70/110 95 %
13 PC/NNDMEU 110/70 2 %
14 NNDMEU ALL 80 %
PCITHPA/PM 60/60/60 90 %
16 PC/`IHPA/E13A 60/60/60 90 %
17 PC/THPA/MIAR 60/60/60 70 %
18 PC~rHPA/lB18 65/65/65 50 %
19 PC~rHPA 120/60 2 %
PC/THPA 100/80 2 %
21 PC~rHPA 80/100 2 %
I
22 PC/1,2~DMI 70/110 60 %
23 PC/I ~ DMI 90/90 50 %
24 PC/1,2-DMI 110/70 5 %
1,2-DMI ALL All toam removed l PC ~ P~leK c~ te; EGDA - Ethylene dycol diacebte; IBIB - Isobutyl Yobutyr te; DB - Dietnylene glycol butyl ether, DM - Diethylene ~col methyl ether; DPM - Diprop~1ene dycol methyl ether; DBE - Dibasic ester (Du Pont); NMP = N-methyl pynol;dinoK; THPA ~ Tetr hydroturhryl da~hol; 1,2-DMI - 1,2-dimethylimidazole; NNDMEU - N,N~-~dimethyl ethylene urea;
PM ~ Propylene g~col methyl ether; EBA ~ Ethylene dycol butyl ether cet te; MIAIC - Methyl iso~myl Icetone ~"~ J~
.
_l ,. . ,.~,~",~,~. ~ , ~
No. Co-Sol~nl Syslem Compononts Wolght Ratio o~ Approximate % Rlgid Componentc Poam Removed l , . . ._ . .. ~ .. . __. _ .
26 PC~rMU 60/120 80 %
. ._ . . _ ~
¦ 27 PC/TMU 100/100 50 %
2~t PC~IMU 120/60 5 %
.
29 TMU ALL All foam removed . _ _ - __ ¦ 30 PC/Furfuryi alcohol 1/2 80 %
¦ 31 1,2-BC¦f~yclohexanone/DEt 1/l/l 75 %
¦ 32 PC/Cyclohexanone/DB 65/65/65 50 %
1 33 PC/eB 100/80 40 %
¦ 34 PC/DBE/DB 65/65/65 30 %
¦ 35 DBe ALL No change 36 pC/PM 1/l 20 %
l ~
37 PC/MIBR/DB 1/l/l 20 %
~ pC/Dbcetone alcohol/DB 1/l/l 20 %
¦ 39 DMB ALL All foam lemoved ¦ 40 PC ALL No change 41 EC 50 ALL No change EC-50 - 50/50 by weight blend of Telacar EC and PC; PC ~ P~ lene c tbonate; TMU - Tetrametbyl urea; 1,2-BC = 1,2-butylene ca bon te; DB ~ Diethylene dycol butyl ether, EB - Ethytene dycol butyt ether, PM - P~lene dycol methyt elher, DM = Diethytcne dycol methyl ether, DBe - Dib~uic ecter (Du Pont); PM ~ P~pylene dycol methyt ether, MIBK = Methyl i~butyl l~etone;
DMP - Di~nethyl form~mide.
(4) good load-bearing ability; and (5) high dimensional stability.
Generally, rigid polyurethane foams are based on polyols having a molecular weight less than 1000, and more often from about 400 to about 800. Rigid polyurethane foams are usually based on a polyol having a functionality of 2 to 8, and more typically from about 4 to about 8.
The invention will be further illustrated by the following examples, which are given by way of illustration and not as limitations on the scope of this invention.
Examples In the examples recorded in the table below, the following procedure was used. Previously coated stainless steel 3/4" screw stock rods were wire brushed and cleaned with a solvent.
Rods that had been coated with cured fiberglass were treated with acetone to remove any fiberglass residue; those that had been coated with cured flexible or rigid polyurethane foam were treated with methylene chloride. The rods were then sand blasted with micro beads. The rods were then coated with a polyether-based foam formulation having the following components:
Component Parts bv Weiaht Thanol~ R-350-X 36.9 DC-1931 tsilicon surfactant) 0.5 Rll (trichlorofluoromethane) 15.0 TEXACAT~ TD-33 0.3 Rubinate M2 (polymeric isocyanate) 49.6 lDow Corning; 2ICI.
The coatings were then allowed to cure for two days or more before dissolution studies were begun. Each coated stock rod was then suspended in a beaker from a ring stand. Each beaker contained one of the alkylene carbonate-containing formulations to be tested. At the bottom of each beaker was a stirring bar. After from about 16 to about 22 hours at room temperature the rods were observed and the approximate percentage of rigid polyurethane foam removed by each formulation was estimated and recorded.
3 i~
~ _ ,.___ __= ~.. _ Ex No Co-Solvent Systcm Components Weight Ratlo d Appro~mate % Rigid Components Foam Removed .___ 1 PC/2-ethyl-1-hexanol/EGDA 45/90/45 All foam removed 2 PC¦2-ethyl-1-hexanol/EGDA 45/45/90 10 %
._ 3 PC/2-elhyl-l hexanol/2-ethylhoxyl 60/60/60 All toam removed 4 PC/2-ethyl-1-hexanol/lBlB 60/60/60 All toam temoved PC/2-ethyl-1-hexanol/DB 60/60/60 70 %
6 PC/2-ethyl-1-hexanol/DM 60/60/60 60 %
7 PC/2-ethyl-1-hexanol/DPM 60/60/60 50 %
8 PC/2-ethyl-1-hexanol!Cyclohexanone 60/60/60 50 %
9 PC/2-ethyl-1-hexanol/DBe 45/45/90 10 %
PC/NMP 100/100 99 %
11 NMP ALL All foam removed .
12 PC/NNDMEU 70/110 95 %
13 PC/NNDMEU 110/70 2 %
14 NNDMEU ALL 80 %
PCITHPA/PM 60/60/60 90 %
16 PC/`IHPA/E13A 60/60/60 90 %
17 PC/THPA/MIAR 60/60/60 70 %
18 PC~rHPA/lB18 65/65/65 50 %
19 PC~rHPA 120/60 2 %
PC/THPA 100/80 2 %
21 PC~rHPA 80/100 2 %
I
22 PC/1,2~DMI 70/110 60 %
23 PC/I ~ DMI 90/90 50 %
24 PC/1,2-DMI 110/70 5 %
1,2-DMI ALL All toam removed l PC ~ P~leK c~ te; EGDA - Ethylene dycol diacebte; IBIB - Isobutyl Yobutyr te; DB - Dietnylene glycol butyl ether, DM - Diethylene ~col methyl ether; DPM - Diprop~1ene dycol methyl ether; DBE - Dibasic ester (Du Pont); NMP = N-methyl pynol;dinoK; THPA ~ Tetr hydroturhryl da~hol; 1,2-DMI - 1,2-dimethylimidazole; NNDMEU - N,N~-~dimethyl ethylene urea;
PM ~ Propylene g~col methyl ether; EBA ~ Ethylene dycol butyl ether cet te; MIAIC - Methyl iso~myl Icetone ~"~ J~
.
_l ,. . ,.~,~",~,~. ~ , ~
No. Co-Sol~nl Syslem Compononts Wolght Ratio o~ Approximate % Rlgid Componentc Poam Removed l , . . ._ . .. ~ .. . __. _ .
26 PC~rMU 60/120 80 %
. ._ . . _ ~
¦ 27 PC/TMU 100/100 50 %
2~t PC~IMU 120/60 5 %
.
29 TMU ALL All foam removed . _ _ - __ ¦ 30 PC/Furfuryi alcohol 1/2 80 %
¦ 31 1,2-BC¦f~yclohexanone/DEt 1/l/l 75 %
¦ 32 PC/Cyclohexanone/DB 65/65/65 50 %
1 33 PC/eB 100/80 40 %
¦ 34 PC/DBE/DB 65/65/65 30 %
¦ 35 DBe ALL No change 36 pC/PM 1/l 20 %
l ~
37 PC/MIBR/DB 1/l/l 20 %
~ pC/Dbcetone alcohol/DB 1/l/l 20 %
¦ 39 DMB ALL All foam lemoved ¦ 40 PC ALL No change 41 EC 50 ALL No change EC-50 - 50/50 by weight blend of Telacar EC and PC; PC ~ P~ lene c tbonate; TMU - Tetrametbyl urea; 1,2-BC = 1,2-butylene ca bon te; DB ~ Diethylene dycol butyl ether, EB - Ethytene dycol butyt ether, PM - P~lene dycol methyt elher, DM = Diethytcne dycol methyl ether, DBe - Dib~uic ecter (Du Pont); PM ~ P~pylene dycol methyt ether, MIBK = Methyl i~butyl l~etone;
DMP - Di~nethyl form~mide.
Claims (20)
1. In a process for removing a cured rigid polyurethane foam from a substrate by contacting said rigid polyurethane foam with a solvent in which said cured rigid polyurethane foam is at least partially soluble, the improvement comprising diluting said solvent with a co-solvent comprising alkylene carbonate.
2. The process of claim 1, in which the alkylene carbonate is 1,2-butylene carbonate.
3. The process of claim 1, in which the alkylene carbonate is propylene carbonate.
4. The process of claim 1, in which the rigid polyurethane foam is a polyether-based polyurethane foam.
5. The process of claim 1, in which the alkylene carbonate is ethylene carbonate.
6. A process for removing cured rigid polyurethane foam from a substrate, comprising contacting a cured rigid polyurethane foam with a co-solvent system comprising a mixture of alkylene carbonate and at least one non-alkylene carbonate solvent selected from the group consisting of aromatic hydrocarbons, alcohols, ketones, esters, ethers, glycol ethers, imidazoles, and ureas.
7. The process of claim 6, further comprising the second step of mechanically agitating the rigid polyurethane foam attached to the surface of said substrate.
8. The process of claim 6, in which the co-solvent system is heated to a temperature of about 50 to about 100 °C.
9. The process of claim 6, in which the cured rigid polyurethane foam is contacted with the co-solvent system at room temperature.
10. The process of claim 6, in which the non-alkylene carbonate solvent is selected from the group consisting of 2-ethyl-1-hexanol, 2-ethylhexyl acetate, N-methyl pyrrolidinone, tetrahydrofurfuryl alcohol, ethylene glycol butyl ether acetate, tetramethyl urea, diethylene glycol butyl ether, ethylene glycol butyl ether, methyl iso-amyl ketone, diethylene glycol methyl ether, dipropylene glycol methyl ether, methyl isobutyl ketone, 1,2-dimethyl imidazole, N,N'-dimethyl ethylene urea, propylene glycol methyl ether, cyclohexanone, diacetone alcohol, furfuryl alcohol, dimethyl formamide, and isobutyl isobutyrate.
11. The process of claim 6, in which the non-alkylene carbonate solvent is selected from the group consisting of 2-ethyl-1-hexanol, N-methyl pyrrolidinone, tetramethyl urea, 1,2-dimethyl imidazole, N,N'-dimethyl ethylene urea, furfuryl alcohol, tetrahydrofurfuryl alcohol, propylene glycol methyl ether, ethylene glycol butyl ether acetate, and dimethyl formamide.
12. The process of claim 6, in which the alkylene carbonate is 1,2-butylene carbonate.
13. The process of claim 6, in which the alkylene carbonate is propylene carbonate.
14. The process of claim 6, in which the alkylene carbonate is ethylene carbonate.
15. The process of claim 6, in which the weight ratio of alkylene carbonate to non-alkylene carbonate solvents in the mixture is from about 1:2 to about 1:3.
16. The process of claim 6, in which the co-solvent system comprises a mixture of alkylene carbonate and at least two non-alkylene carbonate solvents selected from the group consisting of 2-ethyl-l-hexanol, ethylene glycol diacetate, 2-ethylhexyl acetate, N-methyl pyrrolidinone, tetrahydrofurfuryl alcohol, ethylene glycol butyl ether acetate, tetramethyl urea, diethylene glycol butyl ether, ethylene glycol butyl ether, methyl iso-amyl ketone, diethylene glycol methyl ether, dipropylene glycol methyl ether, dibasic ester, methyl isobutyl ketone, 1,2-dimethyl imidazole, N,N'-dimethyl ethylene urea, propylene glycol methyl ether, cyclohexanone, diacetone alcohol, furfuryl alcohol, dimethyl formamide, and isobutyl isobutyrate.
17. The process of claim 6, in which the rigid polyurethane foam is a polyether-based polyurethane foam.
18. A process for dissolving cured rigid polyurethane foam, comprising contacting a cured rigid polyurethane foam with a co-solvent system comprising a mixture of (1) an alkylene carbonate selected from the group consisting of ethylene carbonate, propylene carbonate, and 1,2-butylene carbonate and (2) at least one non-alkylene carbonate solvent in which said rigid polyurethane foam is at least partially soluble, selected from the group consisting of aromatic hydrocarbons, alcohols, ketones, esters, ethers, glycol ethers, imidazoles, and ureas.
19. The process of claim 18, in which the cured rigid polyurethane foam is a polyether-based polyurethane foam.
20. The process of claim 18, in which the non-alkylene carbonate solvent is selected from the group consisting of 2-ethyl-1-hexanol, N-methyl pyrrolidinone, tetramethyl urea, 1,2-dimethyl imidazole, N,N'-dimethyl ethylene urea, furfuryl alcohol, tetrahydrofurfuryl alcohol, propylene glycol methyl ether, ethylene glycol butyl ether acetate, and dimethyl formamide.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US62681890A | 1990-12-13 | 1990-12-13 | |
| US07/626,818 | 1990-12-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2056784A1 true CA2056784A1 (en) | 1992-06-14 |
Family
ID=24511992
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2056784 Abandoned CA2056784A1 (en) | 1990-12-13 | 1991-12-02 | Process for removing cured rigid polyurethane foams from substrates |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2056784A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2714604A1 (en) * | 2011-05-31 | 2014-04-09 | Ferro Corporation | Low volatile organic component medium |
-
1991
- 1991-12-02 CA CA 2056784 patent/CA2056784A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2714604A1 (en) * | 2011-05-31 | 2014-04-09 | Ferro Corporation | Low volatile organic component medium |
| EP2714604A4 (en) * | 2011-05-31 | 2014-12-10 | Ferro Corp | Low volatile organic component medium |
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