CA2355908A1 - Aqueous dispersions or solutions having a long shelf life and containing isocyanate-reactive polymers and surface-deactivating solid polyisocyanates, method for producing same and method for producing a layer - Google Patents
Aqueous dispersions or solutions having a long shelf life and containing isocyanate-reactive polymers and surface-deactivating solid polyisocyanates, method for producing same and method for producing a layer Download PDFInfo
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- CA2355908A1 CA2355908A1 CA002355908A CA2355908A CA2355908A1 CA 2355908 A1 CA2355908 A1 CA 2355908A1 CA 002355908 A CA002355908 A CA 002355908A CA 2355908 A CA2355908 A CA 2355908A CA 2355908 A1 CA2355908 A1 CA 2355908A1
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- isocyanate
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
- C08G18/703—Isocyanates or isothiocyanates transformed in a latent form by physical means
- C08G18/705—Dispersions of isocyanates or isothiocyanates in a liquid medium
- C08G18/706—Dispersions of isocyanates or isothiocyanates in a liquid medium the liquid medium being water
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G2170/00—Compositions for adhesives
- C08G2170/80—Compositions for aqueous adhesives
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- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Polyurethanes Or Polyureas (AREA)
Abstract
The invention relates to one-pack aqueous dispersions or solutions of functional polymers, whereby said dispersions or solutions have a long shelf life, and to surface-deactivating solid polyisocyanates which cross-link under normal conditions. The aqueous dispersions contain solid polyisocyanates which have been surface-deactivated with polyamines. Said polyisocyanates have an average particle size less than or equal to 10 µm and functional isocyanate-reactive polymers. Characteristics of the polymers which are dispersed or dissolved in water are a minimal film-forming temperature (MFT) less than or equal to +5~ C, a glass-transition temperature Tg less than or equal to -5~ C
and a storage module G' less than or equal to 107 Pa when measured at 10 Hertz and at 10~ C. After application and evaporation of the water, a closed film is building up. Said film can dissolve the surface-deactivation of the solid isocyanates which are dissolved in the polymer phase and react spontaneously with the functional groups under normal conditions, i.e. with the hydroxyl and amino groups of the polymer. Polymer layers having a higher heat and solvent resistance are the result. Said layers can be used as contact adhesives, assembly adhesives or coatings.
and a storage module G' less than or equal to 107 Pa when measured at 10 Hertz and at 10~ C. After application and evaporation of the water, a closed film is building up. Said film can dissolve the surface-deactivation of the solid isocyanates which are dissolved in the polymer phase and react spontaneously with the functional groups under normal conditions, i.e. with the hydroxyl and amino groups of the polymer. Polymer layers having a higher heat and solvent resistance are the result. Said layers can be used as contact adhesives, assembly adhesives or coatings.
Description
Aqueous dispersions or solutions having a long shelf life and containing isocyanate-reactive polymers and surface-deactivating solid polyisocyanates, method for producing same and method for producing a layer The invention relates to aqueous, storage-stable dispersions or solutions, which contain isocyanate-reactive polymers and surface-deactivated solid polyisocyanates, to a method for manufacturing the dispersions and to manufacturing a layer.
EP 212 511 discloses aqueous mixtures, storage-stable at room temperature, of functional polymers and dispersed solid polyisocyanates, wherein the solid powder-like polyisocyanates with polyamines according to EP 062 780 are surface-deactivated. These mixtures are used in heat cross-linkable textile printing pigment pastes and in dyeing baths. The reaction of the isocyanate groups with the isocyanate-reactive groups in the polymers, i.e. of the cross-linking, is effected in the region of temperatures over 100°C after the printing procedure, wherein during the procedure the water simultaneously evaporates.
JP 09188735 discloses storage-stable, reactive, oil-in-water emulsions and dispersions.
Liquid or solid polyisocyanates are emulsified or dispersed into a solid or liquid hydrophobic substrate such as paraffin oil or wax with the aid of a polymeric wetting agent. In a second step the hydrophobic dispersion is added to an aqueous dispersion which contains isocyanate-reactive polymers. The manufacture of the oil-in-water emulsion/dispersion is complicated and renders necessary the addition of undesired auxiliary agents.
The object of the present invention is the manufacture of aqueous dispersions or solutions which contain solid, surface-deactivated polyisocyanates and isocyanate-reactive polymers, and which in this form, i.e. as aqueous dispersions or solutions, are storage-stable, but when deposited as a layer under normal conditions after removal of the considerable part of water cross-link.
This object is achieved by the characterizing part of the independent claims.
In particular it is achieved by an aqueous, storage-stable dispersion or solution which contains at least one solid surface-deactivated polyisocyanate and least one polymer containing isocyanate-reactive groups, wherein the storage module G' of the isocyanate-reactive polymer is smaller or equal to 10' Pa when one measures at + 10°C and 10 Hz. The minimal film-forming temperature of the dispersion or solution, the glass transition temperature Tg of the isocyanate-reactive polymer and the particle diameter of the deactivated, solid polyisocyanates must then be specified or defined such that after the escaping of the main part of the solvent or dispersing agent and the formation of a closed film under process conditions, in particular normal conditions, the reaction between the isocyanate groups of the solid, surface-deactivated polyisocyanate and of the isocyanate-reactive groups of the polymer may be initiated.
These properties of the dispersion according to the invention are then achieved when the isocyanate-reactive polymer is selected in a manner such that at the process temperature translatoric movements of the main chain segments are possible. This is then given when the glass transition temperature Tg of the isocyanate-reactive polymer lies at least 10°C
below the process temperature and the minimal film-forming temperature (MFT) of the dispersion or solution.
Durable films are then achieved when the average diameter of the solid, deactivated polyisocanates is selected such that the added quantity is present distributed uniformly in the dispersion and in the film. Uniformly distributed means that the cross-linking of the isocyanate-reactive groups in the polymer takes place without such local deviations on account of which the durability of the cross-linked film would be endangered.
One embodiment form of the aqueous, storage-stable dispersion or solution which contains at least one solid surface-deactivated polyisocyanate and at least one isocyanate-reactive polymer is then given when the following conditions are fulfilled:
(a) the minimal film-forming temperature (MFT) of the dispersion or solution is smaller or equal to +5°C;
(b) the glass transition temperature (Tg) of the isocyanate-reactive polymer must be smaller or equal to -5°C;
(c) the storage module G' of the isocyanate-reactive polymer must be smaller or equal to 10' Pa at 10°C and 10 Hz;
EP 212 511 discloses aqueous mixtures, storage-stable at room temperature, of functional polymers and dispersed solid polyisocyanates, wherein the solid powder-like polyisocyanates with polyamines according to EP 062 780 are surface-deactivated. These mixtures are used in heat cross-linkable textile printing pigment pastes and in dyeing baths. The reaction of the isocyanate groups with the isocyanate-reactive groups in the polymers, i.e. of the cross-linking, is effected in the region of temperatures over 100°C after the printing procedure, wherein during the procedure the water simultaneously evaporates.
JP 09188735 discloses storage-stable, reactive, oil-in-water emulsions and dispersions.
Liquid or solid polyisocyanates are emulsified or dispersed into a solid or liquid hydrophobic substrate such as paraffin oil or wax with the aid of a polymeric wetting agent. In a second step the hydrophobic dispersion is added to an aqueous dispersion which contains isocyanate-reactive polymers. The manufacture of the oil-in-water emulsion/dispersion is complicated and renders necessary the addition of undesired auxiliary agents.
The object of the present invention is the manufacture of aqueous dispersions or solutions which contain solid, surface-deactivated polyisocyanates and isocyanate-reactive polymers, and which in this form, i.e. as aqueous dispersions or solutions, are storage-stable, but when deposited as a layer under normal conditions after removal of the considerable part of water cross-link.
This object is achieved by the characterizing part of the independent claims.
In particular it is achieved by an aqueous, storage-stable dispersion or solution which contains at least one solid surface-deactivated polyisocyanate and least one polymer containing isocyanate-reactive groups, wherein the storage module G' of the isocyanate-reactive polymer is smaller or equal to 10' Pa when one measures at + 10°C and 10 Hz. The minimal film-forming temperature of the dispersion or solution, the glass transition temperature Tg of the isocyanate-reactive polymer and the particle diameter of the deactivated, solid polyisocyanates must then be specified or defined such that after the escaping of the main part of the solvent or dispersing agent and the formation of a closed film under process conditions, in particular normal conditions, the reaction between the isocyanate groups of the solid, surface-deactivated polyisocyanate and of the isocyanate-reactive groups of the polymer may be initiated.
These properties of the dispersion according to the invention are then achieved when the isocyanate-reactive polymer is selected in a manner such that at the process temperature translatoric movements of the main chain segments are possible. This is then given when the glass transition temperature Tg of the isocyanate-reactive polymer lies at least 10°C
below the process temperature and the minimal film-forming temperature (MFT) of the dispersion or solution.
Durable films are then achieved when the average diameter of the solid, deactivated polyisocanates is selected such that the added quantity is present distributed uniformly in the dispersion and in the film. Uniformly distributed means that the cross-linking of the isocyanate-reactive groups in the polymer takes place without such local deviations on account of which the durability of the cross-linked film would be endangered.
One embodiment form of the aqueous, storage-stable dispersion or solution which contains at least one solid surface-deactivated polyisocyanate and at least one isocyanate-reactive polymer is then given when the following conditions are fulfilled:
(a) the minimal film-forming temperature (MFT) of the dispersion or solution is smaller or equal to +5°C;
(b) the glass transition temperature (Tg) of the isocyanate-reactive polymer must be smaller or equal to -5°C;
(c) the storage module G' of the isocyanate-reactive polymer must be smaller or equal to 10' Pa at 10°C and 10 Hz;
(d) the average particle diameter of the solid surface-deactivated polyisocyanate must be smaller or equal to 10 ~m (weight average).
Aqueous dispersions or solutions which contain isocyanate-reactive polymers and surface-deactivated solid polyisocyanates and which obey the above conditions, are storage-stable.
Storage-stable in this context means that the reactive groups of both components essentially do not react and thus remain unchanged and their cross-linking capability remains as long as they are present in an aqueous dispersion or solution. The term "essentially do not react" within the context of the present invention is to be understood in that within one month storage under normal conditions not more than 30% of the isocyanate-reactive groups of the polymer react or cross-link with the isocyanate groups of the solid, surface-deactivated polyisocyanates.
The cross-linking sets in after the evaporation of the main part of the water.
If the dispersion or solution is applied as a layer this means that the main part of the water is removed when a closed film has formed. Under the term film formation according to DIN SS94S:1996-09 the transition of a deposited coating substance from the liquid to the solid condition is indicated. The film formation may be effected by drying. The formation of a closed film is a condition for diffusion, i.e. the dissolving of the surface-deactivated polyisocyanates in the isocyanate-reactive polymers and the subsequent cross-linking reaction.
Process conditions are to be understood as a temperature greater or equal to +S°C and a relative air humidity of less than 9S%.
Normal conditions are to be understood as a standardization to 23°C and 6S% relative air humidity.
The minimal film-forming temperature or also least film forming temperature (N1FT) indicates the temperature above which a dispersion forms a closed film. Below this the film formation in is usually delayed or incomplete. The MFT is determined according to DIN
53787:1974-02.
Aqueous dispersions or solutions which contain isocyanate-reactive polymers and surface-deactivated solid polyisocyanates and which obey the above conditions, are storage-stable.
Storage-stable in this context means that the reactive groups of both components essentially do not react and thus remain unchanged and their cross-linking capability remains as long as they are present in an aqueous dispersion or solution. The term "essentially do not react" within the context of the present invention is to be understood in that within one month storage under normal conditions not more than 30% of the isocyanate-reactive groups of the polymer react or cross-link with the isocyanate groups of the solid, surface-deactivated polyisocyanates.
The cross-linking sets in after the evaporation of the main part of the water.
If the dispersion or solution is applied as a layer this means that the main part of the water is removed when a closed film has formed. Under the term film formation according to DIN SS94S:1996-09 the transition of a deposited coating substance from the liquid to the solid condition is indicated. The film formation may be effected by drying. The formation of a closed film is a condition for diffusion, i.e. the dissolving of the surface-deactivated polyisocyanates in the isocyanate-reactive polymers and the subsequent cross-linking reaction.
Process conditions are to be understood as a temperature greater or equal to +S°C and a relative air humidity of less than 9S%.
Normal conditions are to be understood as a standardization to 23°C and 6S% relative air humidity.
The minimal film-forming temperature or also least film forming temperature (N1FT) indicates the temperature above which a dispersion forms a closed film. Below this the film formation in is usually delayed or incomplete. The MFT is determined according to DIN
53787:1974-02.
After the removal of the main part of the water or after the formation of a closed film the dissolving procedure sets in and the compact deactivating layer is destroyed, by which means the isocyanate groups are accessible for a reaction with the reactive groups of the polymer. At the same time there may occur undesirable side reactions of the isocyanate groups with the remains of water.
Since however at this point in time the concentration of water has already been greatly reduced, the side reaction is considerably suppressed and in comparison to the cross-linking dispersions of the state of the art hardly appears at all.
In the course of the present invention the term dispersion also includes emulsions and suspensions.
The pH-value of the dispersion or solution lies in the range of 6 to 9, preferably 7 and 8. If necessary by way of the addition of anorganic or organic bases or acids the pH-value may be brought into the desired region.
The isocyanate-reactive polymers may be manufactured by polymerization of olefinic unsaturated monomers in solution, emulsion or suspension. They contain 0.2 to 15%, preferably 1 to 8% polymerized-in monomers with isocyanate-reactive groups such as hydroxyl-, amino- and acid amide groups.
Furthermore also applicable are water-soluble and water-dispersible polyurethane and polyurea dispersions, which arise by way of reaction of amorphous or part-crystalline, reactive polyesters, sulfopolyesters, polycaprolactones, polycarbonates and polyethers carrying sulfoxyl-, carboxyl-, hydroxyl- as well as primary or secondary amino groups, with aliphatic or aromatic polyisocyanates.
The concentration of the isocyanate-reactive polymers in water is approximately 30 - 70% by weight, preferably 40 - 60% by weight, even more preferred 45 to 55% by weight of the total weight of the dispersion or solution.
S
The glass transition temperature Tg of the isocyanate-reactive polymers of the dispersion must be smaller or equal to -5°C. The glass transition temperature Tg indicates the temperature at which amorphous or part-crystalline polymers go from the liquid or rubber-elastic condition into the hard-elastic or glassy condition and reverse. The visco-elastic parameters (glass transition temperature and storage module) of the films resulting from the dispersions are determined with DTMA (dynamic, thermomechanic analysis) according to ISO 6721-1. Caloric measurements (DSC
Differential Scanning Calorimetry) are likewise applicable. Suitable methods are standardized in DIN 53765: 1994-03 and ISO 11357-2: 1996. A description of the dynamic thermomechanic properties and their evaluation is furthermore contained in the Encyclopedia of Polymer Science and Engineering, Vol. 5; H.F. Mark ed.; New York 1986, p. 299fF.
In the region below the glass transition temperature the movability of the chain segments of the polymer is so low that no diffusion of the isocyanates takes place within a useable time period.
Some of the suitable isocyanate-reactive polymers, for example polyurethanes and polyureas may have incompatible blocks and phase separations and by way of this several glass transition temperatures. In the case present here Tg is important which corresponds to the softening temperatures of the longer chain segments, thus of the polyether and polyester chains.
In the course of the present invention the glass transition temperature of the polymer is determined in the condition in which it is present within the dispersion or solution. This is of significance because to the dispersion or solution according to requirement, softeners, solvents and other additives are added, which may reduce the glass transition temperature of the isocyanate-reactive polymer. Thus according to the invention also such isocyanate-reactive polymers are suitable, which specifically have glass transition temperatures of larger than -5°C which however by way of suitable additives, in particular softeners or solvents, reach a glass transition temperature of smaller or equal to -5°C.
The storage module G', measured before the cross-linking with the polyisocyanates, must be equal or smaller than 10' Pa at +10°C and 10 Hz. The size of the storage module G' is deduced from the DTMA diagram, measured at 10 Hz and a temperature of 10°C. Only when the storage module G' is smaller or equal to 10' Pa is the movability of the polymer sufficiently large that diffusion and reaction of the polyisocyanates with the isocyanate-reactive groups of the polymer takes place. The storage module G' is determined analogously to the glass transition temperature in the condition in which the polymer is present in the dispersion or solution.
As solid surface-deactivated polyisocyanates there are suitable all water-insoluble diisocyanates or polyisocyanates or their mixtures, as long as they have a melting point above 40°C.
They may be aliphatic, cycloaliphatic, heterocyclic or aromatic polyisocyanates. As examples there are mentioned: diphenylmethane-4,4'-diisocyanate (4,4'-MDI), dimeric 4,4'-MDI, napthalene-1.5-diisocyanate (NDI), 3,3'-dimethyl-biphenyl-4,4'-diiscocyanate (TODD, dimeric 1-methyl-2,4-phenylene-diisocyanate (TDI-L~, 3,3'-diisocyanato-4,4'-dimethyl-N,N'-diphenyl urea (TDHI), addition product of 2 moles of 4,4'-MDI with one mole of diethylene glycol, addition product of 2 moles of 1-methyl-2,4-phenylene-diisocyanate with 1 mole of 1,2-ethanediol or 1,4-butanediol, the isocyanurate of IPDI (IPDI-T).
The solid polyisocyanates should preferably be present in powder form with an average particle size diameter smaller than or equal to 10~m (weight average). As a rule with the synthesis they turn out as powder with the demanded particle sizes of 10 ~m or less, otherwise the solid polyisocyanates (before the deactivation reaction) must be brought into the particle range according to the invention by way of grinding processes and/or screen processes. These methods are the state of the art.
Alternatively the powder-like polyisocyanates by way of a wet grinding connected after the surface deactivation, and a fine dispersion, may be brought to an average particle size equal to or less than 10 Vim. For this there are suitable dispersing apparatus of the rotor-stator type, agitator ball mills, pearl and sand mills, ball mills and friction gap mills. According to the polyisocyanate and application, the grinding is effected on the deactivated polyisocyanate, in the presence of the deactivating agent, in the non-reactive dispersing agent or water with a subsequent deactivation. The ground and surface-stabilized polyisocyanate may also be separated from the grinding dispersions and dried. The method is described in EP 204 970.
The surface stabilization reaction may be carried out in different ways:
- By dispersion of the powder-like isocyanate in a solution of the deactivating agent.
Since however at this point in time the concentration of water has already been greatly reduced, the side reaction is considerably suppressed and in comparison to the cross-linking dispersions of the state of the art hardly appears at all.
In the course of the present invention the term dispersion also includes emulsions and suspensions.
The pH-value of the dispersion or solution lies in the range of 6 to 9, preferably 7 and 8. If necessary by way of the addition of anorganic or organic bases or acids the pH-value may be brought into the desired region.
The isocyanate-reactive polymers may be manufactured by polymerization of olefinic unsaturated monomers in solution, emulsion or suspension. They contain 0.2 to 15%, preferably 1 to 8% polymerized-in monomers with isocyanate-reactive groups such as hydroxyl-, amino- and acid amide groups.
Furthermore also applicable are water-soluble and water-dispersible polyurethane and polyurea dispersions, which arise by way of reaction of amorphous or part-crystalline, reactive polyesters, sulfopolyesters, polycaprolactones, polycarbonates and polyethers carrying sulfoxyl-, carboxyl-, hydroxyl- as well as primary or secondary amino groups, with aliphatic or aromatic polyisocyanates.
The concentration of the isocyanate-reactive polymers in water is approximately 30 - 70% by weight, preferably 40 - 60% by weight, even more preferred 45 to 55% by weight of the total weight of the dispersion or solution.
S
The glass transition temperature Tg of the isocyanate-reactive polymers of the dispersion must be smaller or equal to -5°C. The glass transition temperature Tg indicates the temperature at which amorphous or part-crystalline polymers go from the liquid or rubber-elastic condition into the hard-elastic or glassy condition and reverse. The visco-elastic parameters (glass transition temperature and storage module) of the films resulting from the dispersions are determined with DTMA (dynamic, thermomechanic analysis) according to ISO 6721-1. Caloric measurements (DSC
Differential Scanning Calorimetry) are likewise applicable. Suitable methods are standardized in DIN 53765: 1994-03 and ISO 11357-2: 1996. A description of the dynamic thermomechanic properties and their evaluation is furthermore contained in the Encyclopedia of Polymer Science and Engineering, Vol. 5; H.F. Mark ed.; New York 1986, p. 299fF.
In the region below the glass transition temperature the movability of the chain segments of the polymer is so low that no diffusion of the isocyanates takes place within a useable time period.
Some of the suitable isocyanate-reactive polymers, for example polyurethanes and polyureas may have incompatible blocks and phase separations and by way of this several glass transition temperatures. In the case present here Tg is important which corresponds to the softening temperatures of the longer chain segments, thus of the polyether and polyester chains.
In the course of the present invention the glass transition temperature of the polymer is determined in the condition in which it is present within the dispersion or solution. This is of significance because to the dispersion or solution according to requirement, softeners, solvents and other additives are added, which may reduce the glass transition temperature of the isocyanate-reactive polymer. Thus according to the invention also such isocyanate-reactive polymers are suitable, which specifically have glass transition temperatures of larger than -5°C which however by way of suitable additives, in particular softeners or solvents, reach a glass transition temperature of smaller or equal to -5°C.
The storage module G', measured before the cross-linking with the polyisocyanates, must be equal or smaller than 10' Pa at +10°C and 10 Hz. The size of the storage module G' is deduced from the DTMA diagram, measured at 10 Hz and a temperature of 10°C. Only when the storage module G' is smaller or equal to 10' Pa is the movability of the polymer sufficiently large that diffusion and reaction of the polyisocyanates with the isocyanate-reactive groups of the polymer takes place. The storage module G' is determined analogously to the glass transition temperature in the condition in which the polymer is present in the dispersion or solution.
As solid surface-deactivated polyisocyanates there are suitable all water-insoluble diisocyanates or polyisocyanates or their mixtures, as long as they have a melting point above 40°C.
They may be aliphatic, cycloaliphatic, heterocyclic or aromatic polyisocyanates. As examples there are mentioned: diphenylmethane-4,4'-diisocyanate (4,4'-MDI), dimeric 4,4'-MDI, napthalene-1.5-diisocyanate (NDI), 3,3'-dimethyl-biphenyl-4,4'-diiscocyanate (TODD, dimeric 1-methyl-2,4-phenylene-diisocyanate (TDI-L~, 3,3'-diisocyanato-4,4'-dimethyl-N,N'-diphenyl urea (TDHI), addition product of 2 moles of 4,4'-MDI with one mole of diethylene glycol, addition product of 2 moles of 1-methyl-2,4-phenylene-diisocyanate with 1 mole of 1,2-ethanediol or 1,4-butanediol, the isocyanurate of IPDI (IPDI-T).
The solid polyisocyanates should preferably be present in powder form with an average particle size diameter smaller than or equal to 10~m (weight average). As a rule with the synthesis they turn out as powder with the demanded particle sizes of 10 ~m or less, otherwise the solid polyisocyanates (before the deactivation reaction) must be brought into the particle range according to the invention by way of grinding processes and/or screen processes. These methods are the state of the art.
Alternatively the powder-like polyisocyanates by way of a wet grinding connected after the surface deactivation, and a fine dispersion, may be brought to an average particle size equal to or less than 10 Vim. For this there are suitable dispersing apparatus of the rotor-stator type, agitator ball mills, pearl and sand mills, ball mills and friction gap mills. According to the polyisocyanate and application, the grinding is effected on the deactivated polyisocyanate, in the presence of the deactivating agent, in the non-reactive dispersing agent or water with a subsequent deactivation. The ground and surface-stabilized polyisocyanate may also be separated from the grinding dispersions and dried. The method is described in EP 204 970.
The surface stabilization reaction may be carried out in different ways:
- By dispersion of the powder-like isocyanate in a solution of the deactivating agent.
- By furnishing a molten mass of a low-melting polyisocyanate into a solution of the deactivating agent in a non-soluble, liquid dispersion agent.
- By addition of the deactivating agent or of a solution of this, to a dispersion of the solid, fine-particle isocyanate.
The solid polyisocyanates are preferably deactivated by the effect of primary and secondary aliphatic amines, diamines or polyamines, hydrazine derivatives, amidines, guanidines. To have proved successful are ethylenediamine, 1,3-propylenediamine, diethylenetriamine, triethylene-tetramine, 2,5-dimethyl-piperazine, 3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane, methylnonan-diamine, isophorondiamine, 4,4'-diaminodicyclohexyl methane, diamino- and triamino-polypropylene ether, polyamidoamines, and mixtures of mono-, di-, and polyamines.
The concentration of the deactivating agent should be 0.1 to 20, preferred 0.5 to 8 equivalent percent, with respect to the total present isocyanate groups.
The ratio of the isocyanate groups of the surface-deactivated polyisocyanates and of the isocyanate-reactive groups of the polymers should lie in the range of 0.5 to 1.5. This corresponds generally to a concentration of the surface-deactivated solid isocyanate of 0.1 to 15 parts by weight, preferred 1 - 10 parts, very particularly preferred 2 - 8 parts per 100 parts of isocyanate-reactive polymer.
The cross-linking in the closed film may be effected within 1 to 10 days at room temperature, depending on the type of the solid, surface-deactivated polyisocyanate, the functional groups of the polymer, the solubility parameter of the polymer, the reactive or non-reactive additives. The cross-linking reaction may be accelerated by catalysts and where appropriate by temperatures above the normal temperature.
The aqueous dispersion or solution contains where appropriate additional catalysts for the reaction of the isocyanate groups with the functional groups of the polymer.
Furthermore where appropriate solvents, softeners, tackifying resins or low-molecular, isocyanate-reactive compounds, which as an additional effect may exert an influence on the glass transition temperature, the minimal g film forming temperature and on the solubility parameter of the polymer.
Additionally to the aqueous dispersion or solution there may be added aggregates.
Low-molecular polymers or resins are to be understood as those polymers or resins which have a molecular weight equal to or less than 5,000 Da. High-molecular polymers or resins are all those with molecular weights above 5,000 Da (weight average).
The catalysts for the reaction of the isocyanate groups of the polymer are dependent on the system of surface-deactivated isocyanate/isocyanate-reactive polymer; for urethane catalysts these are organic tin, iron, lead, cobalt, bismuth, antimony and zinc compounds or their mixtures.
Preferred are those catalysts which in aqueous solution or dispersion are hydrolysis-stable.
Alkylmercaptide compounds of dibutyl tin are particularly suitable on account of high hydrolysis stability. Tertiary amines such as dimethyl benzyl amine, diazabicyclo-undecene as well as non-volatile polyurethane foam catalysts based on tertiary amine, such as methyldiethanol amine may be used for special purposes or in combination with metal catalysts.
The concentration of the catalysts lies in the range of 0.001 to 3%, preferred 0.01% to 1%
with respect to the reactive system.
The term additive is to be understood as all additions or substances which neither exert an influence on the storage-stability nor on the spontaneous cross-linking (i.e.
on one of the conditions a) to d). To this group there belong e.g. wetting agents, surface-active substances, adhesive additives, organo-functional silanes, protective colloids, organic or anorganic thickening agents, fillers, pigments, dyestuffs, defoamers, biocides, light-stabilizers, aging-stabilizers, corrosion protection agents.
The group of additives which are non-inert according to the above definition comprises solvents, solid and liquid softeners, low-molecular liquid or solid resins, tackifiers, low-molecular isocyanate-reactive compounds. In contrast to the inert aggregates, Tg, MFT
and the solubility parameter of the isocya.nate-reactive polymer may be influenced. For example with the co-use of polar solvents, such as N-methyl pyrrolidone, N-methyl acetamide, dimethyl formamide, propylene carbonate, dioxane, glycol monomethylether acetate, Tg and MFT are reduced.
According to the invention these polar solvents may only be applied when no destruction of the deactivating layer or the polyurea layer is effected.
As low-molecular, isocyanate-reactive compounds water-soluble or emulsifiable, low-molecular liquid polyols and/or polyamines may be applied. Examples are butanediol, trimethylol propane, ethoxylated Bisphenol A, methyl diethanol amine, triethanol amine, amino-terminated polypropylene ether, polyamido amines, 3,5-diethyl-toluylene-2,4- and 2-6-diamine.
The term plasticizer is to be understood as liquid or solid, organic substances with a low vapor-pressure. They may without chemical reaction, preferably by way of their dissolving or swelling capacity, perhaps however also without such, occur in physical interaction with high-polymeric substances amid the formation of a homogeneous system.
Although the transition between the plasticizer and solvent may be flowing, the term solvent is only to be understood as those substances which after curing of the film should have disappeared as completely as possible. Plasticizers should in contrast to this remain in the film as complete as possible in order to give it or its components the desired end properties.
The solubility parameter 8 of the functional polymer should lie in the range of 8.5 to 13.5 (cal/cm3)m. For the definition of the solubility parameter see Rompp Lexikon, Lacke and Druckfarben" publisher U. -Zorll, Stuttgart 1998, pp. 361 ff The manufacture of the dispersions is effected in the known dispersion apparatus, such as dissolvers, agitator mills, pearl mills, rotor-stator mills, planet mixing apparatus. At the same time it is to be taken care that the surface-stabilized, fine-particle polyisocyanates are not subjected to high shear forces so that the urea layer on the surface is not destroyed. From this there could result reactive dispersions with a limited storage time or spontaneous gel formation.
The mixing temperature of the reactive dispersions is in the region of +15°C to +50°C according to the type of the used solid polyisocyanates.
It has proved successful when concentrated, liquid masterbatches are manufactured with the solid, surface-stabilized polyisocyanates which are only added to the aqueous polymer dispersion or solution after the working-in of the components.
The evaporation of the water and thus the formation of the closed film may be accelerated by cold or warm air flows, by way of a low air humidity or by an increased temperature of the substrate.
The solubility and diffusion of the polyisocyanates in the polymer film as well as the reaction of this with the isocyanate-reactive groups of the polymer is favored by increased temperatures of the film or of the substrate.
The effected cross-linking may be macroscopically proved by the increase of the temperature resistance, by the absence of thermoplasticity at increased temperatures, as well as by an increased water resistance (in comparison to the non-cross-linked polymer). Also with analysis methods such as softening point determination, dynamic thermomechanical analysis (DTMA) or solubility determination can the proof of cross-linking be carned out.
The reactive polymer dispersions according to the invention are advantageously used for the following applications:
A. Cross-linked contact adhesive or assembly adhesive with an increased temperature resistance and cohesive strength.
Contact adhesives are to be understood as viscoelastic adhesives which in solvent-free form at room temperature remain permanently sticky and adhesive and at a low substrate specificity with a slight pressing pressure adhere immediately on almost all substrates. The cross-link density (number of isocyanate groups per molecule unit) determines the degree of contact adhesiveness after the complete cross-linking reaction.
The cross-link density (number of isocyanate groups per molecule unit) is determined by i) the number of the functional cross-linkable groups per molecule, ii) the number of equivalent isocyanate groups per equivalent isocyanate-reactive groups.
By way of a possible under-cross-linking the remaining contact adhesiveness and the rise in the temperature resistance in the heat may be controlled in a directed manner.
B. Assembly adhesives which contact-adhere in the non-cross-linked condition.
Cross-linkable contact adhesives which cross-link into non-sticky adhesive layers.
Applications are for example adhesives for flexible or rigid plastic foams.
C. Dry assembly or coating adhesives which are tack-free in the non-cross-linked condition and are contact-adhering in the thermoplastic condition.
In the non-cross-linked condition these reactive dispersions form tack-free, dry films which however before the final cross-linking at room temperature or a slightly increased temperature are thermoplastic and are contact-adhesive with themselves. By way of the application of pressure and/or an increased temperature there is effected the formation of the adhesive bond, which subsequently cross-links.
D. Spontaneously cross-linking laminating adhesives For plastic foils, metal foils, textiles, etc., with or without initial or permanent contact adhesiveness. The base are acrylic copolymers or methacrylic ester copolymers or polyurethane dispersions based on polyether or polyester.
E: Cross-linking textile coatings and cross-linking textile adhesives.
Dispersions based on polyurethane or polyurethane/acrylic, one-component but with an unlimited storage and processing time. Also heat-activatable.
F. Reactive one-component, storage-stable, cross-linking paints and coatings.
Above all based on polyurethane dispersion. "Soft-feel-effect" paints.
The dispersions according to the invention are applicable to a multitude of further application fields and not limited to those above.
The present invention is furthermore explained by way of following examples.
Examples Table 1: Application and testing method, storages storage 1 Application of dispersion at room temperature, after max. 10 minutes joining the adhering surfaces. Storage of bond for 10 days under normal conditions.
Testing heat resistance at 140°C over 30 minutes.
Registering minutes to the failure of the adhesive bond.
storage 2 Application of dispersion at room temperature. Joining adhering surfaces after max. 10, minutes, storage for 3 days under normal conditions.
Then heating under clamping pressure to 120°C (object temperature) for 0.5 hours. Cooling and storage under normal conditions for 24 hours. Testing increasing heat resistance from 40°C to 150°C. Registering:
maximal heat resistance in °C.
storage 3 Deposition on surfaces to be adhered, evaporation of the water at room temperature. Leaving the surface provided with the adhesive layer open to air for 30 days. Joining the adhering surfaces and heating under clamping pressure for 0.5 hours to 120°C, cooling and 24 hour storage under normal conditions. Registering: adhesion of the adhesive surfaces; testing increasing heat resistance.
storage 4 Storage of the liquid dispersion for 20 days at room temperature and 10 days at 35°C, then applying onto adhesive surfaces. Further as with the storages 1 and 2. Testing of the heat resistance of the adhesive bonds:
(Similar to the method ASTM D 4498-85/1989).
Test objects with 100x20x5 mm3 of beech wood were simply press adhered in an overlapping manner, overlapping 10 mm, adhesive surface 20x10 mm2. For determining the heat resistance after storage 1 to 3 the test objects were suspended perpendicularly in the circulating air oven and loaded on one side with 300 g. The loss of strength of the adhesive bond led to a falling of the weights.
In order to rule out the side reaction of water with the isocyanates when forming the bonds after storage 2 and 3, the wooden test specimens where heated to 120 °C
during 0.5 hrs under vacuum at a pressure of 0.1 bar.
When testing the increasing heat resistance after storage 2 and 3, the temperature was increased by 10 °C every 15 minutes, initial temperature 40 °C, end temperature 150 °C.
Manufacture of the aqueous suspension of solid surface-deactivated polyisocyanate: general procedure ( masterbatch):
Under the dissolves at 750 RPM at 15 to 20°C the following aqueous suspensions of surface-deactivated polyisocyanates were manufactured:
parts by weight ( 1 ) water 106 (2) Kelzan S (Monsanto), 3%-solids solution in water 33 (3) polyoxyethylene sorbitane trioleate 1 (4) polyamine 2 - 6 (5) polyisocyanate-powder (average particle size (weight average) < 10 ~m before or after wet grinding) 80 Mixture components; explanations (2) Kelzan S: hydrocolloid, viscosity stabilizer (3) polyoxyethylene sorbitane-trioleate Tween 85 (Fluka): wetting and dispersing agent (4) polyamine: mixture of Euretek 505 (Witco) polyamido-amine and Laromin C
(BASF), 50:50 parts by weight, equivalent 131 g/eq. The quantity of polyamine corresponded to in each case 5 equivalent percent of the isocyanate groups present in the solid polyisocyanate groups:
(5) solid polyisocyanates Theoretical equivalent TDI-U 2,4-toluylene diisocyanate-uretdione TDI-dimer, 174 TDI-H 2,4-toluylene diisocyanate-urea 161 IPDI-T isocyanurate of IPDI 222 Table 2 Applied adhesive dispersions:
A) Alberdingk AC-7505 copolymer of acrylic acid esters, Alberdingk + Boley GmbH 65% solid matter, contact-adhering;
D-Krefeld (PSA) with isocyanate reactive groups in the polymer.
B) Alberdingk U-410 polyether-polyurethane dispersion Alberdingk + Boley GmbH 40% solid matter, with isocyanate-reactive D-Krefeld (PUR) groups in the polymer C) Quilastic DEP-170 polycaprolactone-PUR-dispersion Merquinsa SA aliphatic polyisocyanate, 50% solid E-Barcelona (PUR) matter, with isocyanate-reactive groups in the polymer.
D) Jagotex KEM2010(PVOAc) polyvinyl acetate-acrylate Ernst Jaeger GmbH dispersion, 55% solid matter with D-Duesseldorf isocyanate-reactive groups in the polymer. Contact adhesive with activation temperature 60-80°C
Manufacture of the reactive adhesive dispersions: e~procedure:
If the dispersions in the delivered form had a pH of less than 7, a pH of 7-8 is adjusted by way of addition of aqueous ammonia. set. With the dissolver a reactive dispersion adhesive with the cited polyisocyanates is manufactured as follows:
parts by weight parts by weight in dispersion per 100 polymer (1) adhesive dispersion approx. 40-65 % solid mattter 100 (2) dispersion of deactivated 16 approx. 11.2 polyisocyanate approx. 35%-solids (3) Metatin Katalysator 715; 1 approx. 0.2 Base dibutyl tin alkyl mercaptide (Acima AG, CH-Buchs) 10%-solids in ethylene glycol dimethylether ---------The adhesive mixtures were deposited onto the adhering surfaces of beech wood test objects with a spiral doctor blade, then treated according to the storages 1-3. The deposition weight after the drying was about 100g/m2. Testing as indicated Table 3: Invention-relevant properties of the dispersion in the delivered form. resp. as a water-free film:
dispersions A) and B) dispersions C) and D) according to the invention not according to the invention Dispersion A) PSA B) PUR C) PUR D) PVOAc MFT minimal 0 0 +5 0 - (+5) film forming temperature [°C]
(< +5°C) glass transition - 34 - 30 + 52 - 3 temperature [°C]
(< -5°C) storage modulus 4x 1 OS 3x 106 7x 1 O8 2x 10' at 10°C and Hz, [Pa]
(< 10' Pa) Table 4.1: Heat resistance in °C of the adhesive bond measured after storages 1 to 4 Dispersion A) PSA B) PUR C) PUR D) PVOAc dispersion without 73 58 60 55 solid isocyanate, storage 2, increasing heat resistance, °C
solid polyisocyanate TDI-U TDI-U TDI-H TDI-U
in the dispersion, average particle size < 10~m storage 1 > 30 min > 30 min < 2 min < 2 min days cross-linking at normal conditions, testing at 140°C
for max. 30 min.
storage 2 > 150 > 150 > 1 SO > 150 cross-linking at 120C
after 3 days at normal conditions.
Increasing heat resistance, [C]
storage 3 no contact > 1 SO > 150 > 150 for 3 days adhesion openly stored no bond formation layers, then press adhering at 120C.
Increasing heat resistance C
storage 2 > 150 >150 > 150 > 150 but with dispersion, aged after storage according to according to comparison test comparison test the invention the invention not according to not according to the invention the invention Table 4.2:
Heat resistance in C of the adhesive bond measured in the re~_ ion of 40 - 150C
after stora~es 1 to 4 Dispersion A) PSA B) PUR C) PUR D) PVOAc dispersion 73 58 60 55 without solid isocyanate, storage 2, increasing heat resistance, C
solid polyisocyanateTDI-H TDI-H IPDI-T TDI-H
in the dispersion, average particle size < lOpm storage 1 > 30 min > 30 min < 2 min < 2 min days cross-linking at normal conditions, testing at for max. 30 min.
storage 2 > 150 > 150 > 150 > 150 cross-linking at 120C
after 3 days at normal conditions.
Increasing heat resistance, [C]
storage 3 no contact> 150 > 150 > 150 for 3 days adhesion openly stored no bond layers, formation then press adhering at 120C.
Increasing heat resistance C
storage 2 > 150 >150 > 150 > 150 but with dispersion, aged after storage 4 according to according to comparison test comparison test the invention the invention not according to not according to the invention the invention
- By addition of the deactivating agent or of a solution of this, to a dispersion of the solid, fine-particle isocyanate.
The solid polyisocyanates are preferably deactivated by the effect of primary and secondary aliphatic amines, diamines or polyamines, hydrazine derivatives, amidines, guanidines. To have proved successful are ethylenediamine, 1,3-propylenediamine, diethylenetriamine, triethylene-tetramine, 2,5-dimethyl-piperazine, 3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane, methylnonan-diamine, isophorondiamine, 4,4'-diaminodicyclohexyl methane, diamino- and triamino-polypropylene ether, polyamidoamines, and mixtures of mono-, di-, and polyamines.
The concentration of the deactivating agent should be 0.1 to 20, preferred 0.5 to 8 equivalent percent, with respect to the total present isocyanate groups.
The ratio of the isocyanate groups of the surface-deactivated polyisocyanates and of the isocyanate-reactive groups of the polymers should lie in the range of 0.5 to 1.5. This corresponds generally to a concentration of the surface-deactivated solid isocyanate of 0.1 to 15 parts by weight, preferred 1 - 10 parts, very particularly preferred 2 - 8 parts per 100 parts of isocyanate-reactive polymer.
The cross-linking in the closed film may be effected within 1 to 10 days at room temperature, depending on the type of the solid, surface-deactivated polyisocyanate, the functional groups of the polymer, the solubility parameter of the polymer, the reactive or non-reactive additives. The cross-linking reaction may be accelerated by catalysts and where appropriate by temperatures above the normal temperature.
The aqueous dispersion or solution contains where appropriate additional catalysts for the reaction of the isocyanate groups with the functional groups of the polymer.
Furthermore where appropriate solvents, softeners, tackifying resins or low-molecular, isocyanate-reactive compounds, which as an additional effect may exert an influence on the glass transition temperature, the minimal g film forming temperature and on the solubility parameter of the polymer.
Additionally to the aqueous dispersion or solution there may be added aggregates.
Low-molecular polymers or resins are to be understood as those polymers or resins which have a molecular weight equal to or less than 5,000 Da. High-molecular polymers or resins are all those with molecular weights above 5,000 Da (weight average).
The catalysts for the reaction of the isocyanate groups of the polymer are dependent on the system of surface-deactivated isocyanate/isocyanate-reactive polymer; for urethane catalysts these are organic tin, iron, lead, cobalt, bismuth, antimony and zinc compounds or their mixtures.
Preferred are those catalysts which in aqueous solution or dispersion are hydrolysis-stable.
Alkylmercaptide compounds of dibutyl tin are particularly suitable on account of high hydrolysis stability. Tertiary amines such as dimethyl benzyl amine, diazabicyclo-undecene as well as non-volatile polyurethane foam catalysts based on tertiary amine, such as methyldiethanol amine may be used for special purposes or in combination with metal catalysts.
The concentration of the catalysts lies in the range of 0.001 to 3%, preferred 0.01% to 1%
with respect to the reactive system.
The term additive is to be understood as all additions or substances which neither exert an influence on the storage-stability nor on the spontaneous cross-linking (i.e.
on one of the conditions a) to d). To this group there belong e.g. wetting agents, surface-active substances, adhesive additives, organo-functional silanes, protective colloids, organic or anorganic thickening agents, fillers, pigments, dyestuffs, defoamers, biocides, light-stabilizers, aging-stabilizers, corrosion protection agents.
The group of additives which are non-inert according to the above definition comprises solvents, solid and liquid softeners, low-molecular liquid or solid resins, tackifiers, low-molecular isocyanate-reactive compounds. In contrast to the inert aggregates, Tg, MFT
and the solubility parameter of the isocya.nate-reactive polymer may be influenced. For example with the co-use of polar solvents, such as N-methyl pyrrolidone, N-methyl acetamide, dimethyl formamide, propylene carbonate, dioxane, glycol monomethylether acetate, Tg and MFT are reduced.
According to the invention these polar solvents may only be applied when no destruction of the deactivating layer or the polyurea layer is effected.
As low-molecular, isocyanate-reactive compounds water-soluble or emulsifiable, low-molecular liquid polyols and/or polyamines may be applied. Examples are butanediol, trimethylol propane, ethoxylated Bisphenol A, methyl diethanol amine, triethanol amine, amino-terminated polypropylene ether, polyamido amines, 3,5-diethyl-toluylene-2,4- and 2-6-diamine.
The term plasticizer is to be understood as liquid or solid, organic substances with a low vapor-pressure. They may without chemical reaction, preferably by way of their dissolving or swelling capacity, perhaps however also without such, occur in physical interaction with high-polymeric substances amid the formation of a homogeneous system.
Although the transition between the plasticizer and solvent may be flowing, the term solvent is only to be understood as those substances which after curing of the film should have disappeared as completely as possible. Plasticizers should in contrast to this remain in the film as complete as possible in order to give it or its components the desired end properties.
The solubility parameter 8 of the functional polymer should lie in the range of 8.5 to 13.5 (cal/cm3)m. For the definition of the solubility parameter see Rompp Lexikon, Lacke and Druckfarben" publisher U. -Zorll, Stuttgart 1998, pp. 361 ff The manufacture of the dispersions is effected in the known dispersion apparatus, such as dissolvers, agitator mills, pearl mills, rotor-stator mills, planet mixing apparatus. At the same time it is to be taken care that the surface-stabilized, fine-particle polyisocyanates are not subjected to high shear forces so that the urea layer on the surface is not destroyed. From this there could result reactive dispersions with a limited storage time or spontaneous gel formation.
The mixing temperature of the reactive dispersions is in the region of +15°C to +50°C according to the type of the used solid polyisocyanates.
It has proved successful when concentrated, liquid masterbatches are manufactured with the solid, surface-stabilized polyisocyanates which are only added to the aqueous polymer dispersion or solution after the working-in of the components.
The evaporation of the water and thus the formation of the closed film may be accelerated by cold or warm air flows, by way of a low air humidity or by an increased temperature of the substrate.
The solubility and diffusion of the polyisocyanates in the polymer film as well as the reaction of this with the isocyanate-reactive groups of the polymer is favored by increased temperatures of the film or of the substrate.
The effected cross-linking may be macroscopically proved by the increase of the temperature resistance, by the absence of thermoplasticity at increased temperatures, as well as by an increased water resistance (in comparison to the non-cross-linked polymer). Also with analysis methods such as softening point determination, dynamic thermomechanical analysis (DTMA) or solubility determination can the proof of cross-linking be carned out.
The reactive polymer dispersions according to the invention are advantageously used for the following applications:
A. Cross-linked contact adhesive or assembly adhesive with an increased temperature resistance and cohesive strength.
Contact adhesives are to be understood as viscoelastic adhesives which in solvent-free form at room temperature remain permanently sticky and adhesive and at a low substrate specificity with a slight pressing pressure adhere immediately on almost all substrates. The cross-link density (number of isocyanate groups per molecule unit) determines the degree of contact adhesiveness after the complete cross-linking reaction.
The cross-link density (number of isocyanate groups per molecule unit) is determined by i) the number of the functional cross-linkable groups per molecule, ii) the number of equivalent isocyanate groups per equivalent isocyanate-reactive groups.
By way of a possible under-cross-linking the remaining contact adhesiveness and the rise in the temperature resistance in the heat may be controlled in a directed manner.
B. Assembly adhesives which contact-adhere in the non-cross-linked condition.
Cross-linkable contact adhesives which cross-link into non-sticky adhesive layers.
Applications are for example adhesives for flexible or rigid plastic foams.
C. Dry assembly or coating adhesives which are tack-free in the non-cross-linked condition and are contact-adhering in the thermoplastic condition.
In the non-cross-linked condition these reactive dispersions form tack-free, dry films which however before the final cross-linking at room temperature or a slightly increased temperature are thermoplastic and are contact-adhesive with themselves. By way of the application of pressure and/or an increased temperature there is effected the formation of the adhesive bond, which subsequently cross-links.
D. Spontaneously cross-linking laminating adhesives For plastic foils, metal foils, textiles, etc., with or without initial or permanent contact adhesiveness. The base are acrylic copolymers or methacrylic ester copolymers or polyurethane dispersions based on polyether or polyester.
E: Cross-linking textile coatings and cross-linking textile adhesives.
Dispersions based on polyurethane or polyurethane/acrylic, one-component but with an unlimited storage and processing time. Also heat-activatable.
F. Reactive one-component, storage-stable, cross-linking paints and coatings.
Above all based on polyurethane dispersion. "Soft-feel-effect" paints.
The dispersions according to the invention are applicable to a multitude of further application fields and not limited to those above.
The present invention is furthermore explained by way of following examples.
Examples Table 1: Application and testing method, storages storage 1 Application of dispersion at room temperature, after max. 10 minutes joining the adhering surfaces. Storage of bond for 10 days under normal conditions.
Testing heat resistance at 140°C over 30 minutes.
Registering minutes to the failure of the adhesive bond.
storage 2 Application of dispersion at room temperature. Joining adhering surfaces after max. 10, minutes, storage for 3 days under normal conditions.
Then heating under clamping pressure to 120°C (object temperature) for 0.5 hours. Cooling and storage under normal conditions for 24 hours. Testing increasing heat resistance from 40°C to 150°C. Registering:
maximal heat resistance in °C.
storage 3 Deposition on surfaces to be adhered, evaporation of the water at room temperature. Leaving the surface provided with the adhesive layer open to air for 30 days. Joining the adhering surfaces and heating under clamping pressure for 0.5 hours to 120°C, cooling and 24 hour storage under normal conditions. Registering: adhesion of the adhesive surfaces; testing increasing heat resistance.
storage 4 Storage of the liquid dispersion for 20 days at room temperature and 10 days at 35°C, then applying onto adhesive surfaces. Further as with the storages 1 and 2. Testing of the heat resistance of the adhesive bonds:
(Similar to the method ASTM D 4498-85/1989).
Test objects with 100x20x5 mm3 of beech wood were simply press adhered in an overlapping manner, overlapping 10 mm, adhesive surface 20x10 mm2. For determining the heat resistance after storage 1 to 3 the test objects were suspended perpendicularly in the circulating air oven and loaded on one side with 300 g. The loss of strength of the adhesive bond led to a falling of the weights.
In order to rule out the side reaction of water with the isocyanates when forming the bonds after storage 2 and 3, the wooden test specimens where heated to 120 °C
during 0.5 hrs under vacuum at a pressure of 0.1 bar.
When testing the increasing heat resistance after storage 2 and 3, the temperature was increased by 10 °C every 15 minutes, initial temperature 40 °C, end temperature 150 °C.
Manufacture of the aqueous suspension of solid surface-deactivated polyisocyanate: general procedure ( masterbatch):
Under the dissolves at 750 RPM at 15 to 20°C the following aqueous suspensions of surface-deactivated polyisocyanates were manufactured:
parts by weight ( 1 ) water 106 (2) Kelzan S (Monsanto), 3%-solids solution in water 33 (3) polyoxyethylene sorbitane trioleate 1 (4) polyamine 2 - 6 (5) polyisocyanate-powder (average particle size (weight average) < 10 ~m before or after wet grinding) 80 Mixture components; explanations (2) Kelzan S: hydrocolloid, viscosity stabilizer (3) polyoxyethylene sorbitane-trioleate Tween 85 (Fluka): wetting and dispersing agent (4) polyamine: mixture of Euretek 505 (Witco) polyamido-amine and Laromin C
(BASF), 50:50 parts by weight, equivalent 131 g/eq. The quantity of polyamine corresponded to in each case 5 equivalent percent of the isocyanate groups present in the solid polyisocyanate groups:
(5) solid polyisocyanates Theoretical equivalent TDI-U 2,4-toluylene diisocyanate-uretdione TDI-dimer, 174 TDI-H 2,4-toluylene diisocyanate-urea 161 IPDI-T isocyanurate of IPDI 222 Table 2 Applied adhesive dispersions:
A) Alberdingk AC-7505 copolymer of acrylic acid esters, Alberdingk + Boley GmbH 65% solid matter, contact-adhering;
D-Krefeld (PSA) with isocyanate reactive groups in the polymer.
B) Alberdingk U-410 polyether-polyurethane dispersion Alberdingk + Boley GmbH 40% solid matter, with isocyanate-reactive D-Krefeld (PUR) groups in the polymer C) Quilastic DEP-170 polycaprolactone-PUR-dispersion Merquinsa SA aliphatic polyisocyanate, 50% solid E-Barcelona (PUR) matter, with isocyanate-reactive groups in the polymer.
D) Jagotex KEM2010(PVOAc) polyvinyl acetate-acrylate Ernst Jaeger GmbH dispersion, 55% solid matter with D-Duesseldorf isocyanate-reactive groups in the polymer. Contact adhesive with activation temperature 60-80°C
Manufacture of the reactive adhesive dispersions: e~procedure:
If the dispersions in the delivered form had a pH of less than 7, a pH of 7-8 is adjusted by way of addition of aqueous ammonia. set. With the dissolver a reactive dispersion adhesive with the cited polyisocyanates is manufactured as follows:
parts by weight parts by weight in dispersion per 100 polymer (1) adhesive dispersion approx. 40-65 % solid mattter 100 (2) dispersion of deactivated 16 approx. 11.2 polyisocyanate approx. 35%-solids (3) Metatin Katalysator 715; 1 approx. 0.2 Base dibutyl tin alkyl mercaptide (Acima AG, CH-Buchs) 10%-solids in ethylene glycol dimethylether ---------The adhesive mixtures were deposited onto the adhering surfaces of beech wood test objects with a spiral doctor blade, then treated according to the storages 1-3. The deposition weight after the drying was about 100g/m2. Testing as indicated Table 3: Invention-relevant properties of the dispersion in the delivered form. resp. as a water-free film:
dispersions A) and B) dispersions C) and D) according to the invention not according to the invention Dispersion A) PSA B) PUR C) PUR D) PVOAc MFT minimal 0 0 +5 0 - (+5) film forming temperature [°C]
(< +5°C) glass transition - 34 - 30 + 52 - 3 temperature [°C]
(< -5°C) storage modulus 4x 1 OS 3x 106 7x 1 O8 2x 10' at 10°C and Hz, [Pa]
(< 10' Pa) Table 4.1: Heat resistance in °C of the adhesive bond measured after storages 1 to 4 Dispersion A) PSA B) PUR C) PUR D) PVOAc dispersion without 73 58 60 55 solid isocyanate, storage 2, increasing heat resistance, °C
solid polyisocyanate TDI-U TDI-U TDI-H TDI-U
in the dispersion, average particle size < 10~m storage 1 > 30 min > 30 min < 2 min < 2 min days cross-linking at normal conditions, testing at 140°C
for max. 30 min.
storage 2 > 150 > 150 > 1 SO > 150 cross-linking at 120C
after 3 days at normal conditions.
Increasing heat resistance, [C]
storage 3 no contact > 1 SO > 150 > 150 for 3 days adhesion openly stored no bond formation layers, then press adhering at 120C.
Increasing heat resistance C
storage 2 > 150 >150 > 150 > 150 but with dispersion, aged after storage according to according to comparison test comparison test the invention the invention not according to not according to the invention the invention Table 4.2:
Heat resistance in C of the adhesive bond measured in the re~_ ion of 40 - 150C
after stora~es 1 to 4 Dispersion A) PSA B) PUR C) PUR D) PVOAc dispersion 73 58 60 55 without solid isocyanate, storage 2, increasing heat resistance, C
solid polyisocyanateTDI-H TDI-H IPDI-T TDI-H
in the dispersion, average particle size < lOpm storage 1 > 30 min > 30 min < 2 min < 2 min days cross-linking at normal conditions, testing at for max. 30 min.
storage 2 > 150 > 150 > 150 > 150 cross-linking at 120C
after 3 days at normal conditions.
Increasing heat resistance, [C]
storage 3 no contact> 150 > 150 > 150 for 3 days adhesion openly stored no bond layers, formation then press adhering at 120C.
Increasing heat resistance C
storage 2 > 150 >150 > 150 > 150 but with dispersion, aged after storage 4 according to according to comparison test comparison test the invention the invention not according to not according to the invention the invention
Claims (10)
1. An aqueous, storage-stable dispersion or solution containing at least one solid, surface-deactivated polyisocyanate and least one polymer containing isocyanate-reactive groups, characterized in that the storage module G' of the isocyanate-reactive polymer is smaller or equal to 10 7 Pa at +10°C and 10 Hz, and the minimal film-forming temperature of the dispersion, the glass transition temperature Tg of the isocyanate-reactive polymer and the particle diameter of the deactivated, solid polyisocyanates are set such that after the evaporation of the main part of the dispersing agent or solvent, and the formation of a closed film under process conditions, in particular normal conditions, the reaction between the isocyanate groups of the solid, surface-deactivated polyisocyanate and of the isocanate-reactive groups of the polymer may be initiated.
2. An aqueous, storage-stable dispersion or solution containing at least one solid, surface -modified polyisocyanate and least isocyanate-reactive polymer, characterized in that - the minimal film-forming temperature (MFT) of the dispersion or solution is smaller or equal to + 5°C;
- the glass transition temperature (Tg) of the isocyanate-reactive polymer is smaller or equal to -5°C;
- the storage module G' of the isocyanate-reactive polymer is smaller or equal to 10 7 Pa, measured at 10°C and 10 Hz;
- the average particle diameter of the solid surface-deactivated polyisocyanate is smaller or equal to 10 µm.
- the glass transition temperature (Tg) of the isocyanate-reactive polymer is smaller or equal to -5°C;
- the storage module G' of the isocyanate-reactive polymer is smaller or equal to 10 7 Pa, measured at 10°C and 10 Hz;
- the average particle diameter of the solid surface-deactivated polyisocyanate is smaller or equal to 10 µm.
3. An aqueous dispersion or solution according to claim 1 to 2, characterized in that the pH
-value of the dispersion or solution lies between 6 and 9, preferably between 7 and 8.
-value of the dispersion or solution lies between 6 and 9, preferably between 7 and 8.
4. A layer manufacturable from an aqueous dispersion or solution according to claim 1 to 3, characterized in that the layer cross-links after achieving a closed film.
5. A method for manufacturing layers of storage-stable, aqueous dispersions or solutions, said layers cross-linking at process conditions, in particular normal conditions, characterized in that (a) an aqueous, storage-stable dispersion or solution containing at least one solid, surface-deactivated polyisocyanate and at least one polymer containing isocyanate-reactive groups is prepared, wherein - the minimal film-forming temperature (MFT) of the reactive dispersion is smaller or equal to + 5°C;
- the glass transition temperature (Tg) of the isocyanate-reactive polymer is smaller or equal to -5°C;
- the storage module G' of the isocyanate-reactive polymer is smaller or equal to 10 7 Pa measured at 10 Hz and 10 °C;
- the average particle diameter of the solid polyisocyanate is smaller or equal to 10µm;
(b) the aqueous dispersion or solution is deposited onto at least one substrate as a layer, (c) up to achieving a closed film, the water, where appropriate by way of the effect of heat, cold or warm air flows, low air humidities and/or diffusion into the substrate lying thereunder, is removed;
(d) the reaction between the isocyanate-reactive groups of the polymer with the isocyanate groups of the polyisocyanate is initiated at normal conditions after achieving a closed film.
- the glass transition temperature (Tg) of the isocyanate-reactive polymer is smaller or equal to -5°C;
- the storage module G' of the isocyanate-reactive polymer is smaller or equal to 10 7 Pa measured at 10 Hz and 10 °C;
- the average particle diameter of the solid polyisocyanate is smaller or equal to 10µm;
(b) the aqueous dispersion or solution is deposited onto at least one substrate as a layer, (c) up to achieving a closed film, the water, where appropriate by way of the effect of heat, cold or warm air flows, low air humidities and/or diffusion into the substrate lying thereunder, is removed;
(d) the reaction between the isocyanate-reactive groups of the polymer with the isocyanate groups of the polyisocyanate is initiated at normal conditions after achieving a closed film.
6. A method for manufacturing an aqueous dispersion or solution according to claim 1 to 3, containing at least one surface-deactivated polyisocyanate and at least one polymer containing isocyanate-reactive groups, characterized in that (a) at least one polymer containing isocyanate-reactive groups is dissolved in water and dispersed;
(b) where appropriate inert additives are added;
(c) where appropriate non-inert additives are added;
(d) a liquid masterbatch or dispersion at least of one solid, surface-modified polyisocyanate is manufactured at temperatures in a range of +5°C to +30°C;
(e) the masterbatch obtained under (d) is mixed with the dispersion obtained under (a) to (c).
(b) where appropriate inert additives are added;
(c) where appropriate non-inert additives are added;
(d) a liquid masterbatch or dispersion at least of one solid, surface-modified polyisocyanate is manufactured at temperatures in a range of +5°C to +30°C;
(e) the masterbatch obtained under (d) is mixed with the dispersion obtained under (a) to (c).
7. The use of an aqueous dispersion or solution according to one of the claims 1 or 2 as an adhesive.
8. An aqueous storage-stable dispersion or solution, or a layer manufactured with such a dispersion in accordance with one of the claims 1 to 4, characterized in that the polymer containing the isocyanate-reactive groups is selected from the group of acrylic copolymers or methylacrylic-ester copolymers.
9. An aqueous storage-stable dispersion or solution, or a layer manufactured with such a dispersion in accordance with one of the claims 1 to 4, characterized in that the polymer containing the isocyanate-reactive group is selected from the group of polyurethanes or polyureas, based on polyester or polyether.
10. An aqueous storage-stable dispersion or solution, or a layer manufactured with such a dispersion in accordance with one of the claims 1 to 4, characterized in that the ratio of the isocyanate groups of the polyisocyanate and of the isocyanate groups of the polymers is about 0.1 to 1.5.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP98811247.0 | 1998-12-21 | ||
| EP98811247A EP1013690A1 (en) | 1998-12-21 | 1998-12-21 | Aqueous storage-stable dispersions or solutions containing isocyanate reactive polymers and surface-deactivated solid polyisocyanates and method of preparing the same as well as a method of preparing a layer |
| PCT/CH1999/000577 WO2000037526A1 (en) | 1998-12-21 | 1999-12-01 | Aqueous dispersions or solutions having a long shelf life and containing isocyanate-reactive polymers and surface-deactivating solid polyisocyanates, method for producing same and method for producing a layer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2355908A1 true CA2355908A1 (en) | 2000-06-29 |
Family
ID=8236494
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002355908A Abandoned CA2355908A1 (en) | 1998-12-21 | 1999-12-01 | Aqueous dispersions or solutions having a long shelf life and containing isocyanate-reactive polymers and surface-deactivating solid polyisocyanates, method for producing same and method for producing a layer |
Country Status (5)
| Country | Link |
|---|---|
| EP (2) | EP1013690A1 (en) |
| AU (1) | AU1257100A (en) |
| CA (1) | CA2355908A1 (en) |
| MX (1) | MXPA01006321A (en) |
| WO (1) | WO2000037526A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2400104A (en) * | 2003-04-03 | 2004-10-06 | Bostik Findley Ltd | Adhesive comprising surface-protected polyisocyanate particles |
| US7498380B2 (en) | 2004-05-28 | 2009-03-03 | Bayer Materialscience Ag | Adhesives |
| US9944834B2 (en) | 2014-12-15 | 2018-04-17 | H.B. Fuller Company | Reactive film adhesives with enhanced adhesion to metallic surfaces |
| US11802226B2 (en) | 2013-07-30 | 2023-10-31 | H.B. Fuller Company | Polyurethane adhesive film |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1164154A1 (en) * | 2000-06-15 | 2001-12-19 | Ag Bayer | Pressure-sensitive adhesives with improved shearing resistance at higher temperatures |
| DE10034637B4 (en) * | 2000-07-15 | 2004-04-08 | Jowat Ag | Storage stable isocyanate dispersions |
| DE10140206A1 (en) * | 2001-08-16 | 2003-03-06 | Bayer Ag | One-component isocyanate-crosslinking two-phase systems |
| TW575646B (en) | 2002-09-04 | 2004-02-11 | Sipix Imaging Inc | Novel adhesive and sealing layers for electrophoretic displays |
| US7166182B2 (en) | 2002-09-04 | 2007-01-23 | Sipix Imaging, Inc. | Adhesive and sealing layers for electrophoretic displays |
| TWI327251B (en) * | 2002-09-23 | 2010-07-11 | Sipix Imaging Inc | Electrophoretic displays with improved high temperature performance |
| US7616374B2 (en) | 2002-09-23 | 2009-11-10 | Sipix Imaging, Inc. | Electrophoretic displays with improved high temperature performance |
| US9346987B2 (en) | 2003-01-24 | 2016-05-24 | E Ink California, Llc | Adhesive and sealing layers for electrophoretic displays |
| US7572491B2 (en) | 2003-01-24 | 2009-08-11 | Sipix Imaging, Inc. | Adhesive and sealing layers for electrophoretic displays |
| EP1598382A1 (en) | 2004-05-17 | 2005-11-23 | Sika Technology AG | One part aqueous adhesive dispersion |
| DE102007060240B4 (en) | 2007-12-14 | 2015-03-26 | Lisa Dräxlmaier GmbH | Method for bonding two layers of sheet materials |
| EP3026071A1 (en) | 2014-11-26 | 2016-06-01 | Henkel AG & Co. KGaA | Stabilised polyurethane dispersions |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3529251A1 (en) * | 1985-08-16 | 1987-02-26 | Bayer Ag | COLD-HARDENING COMPOSITIONS, A METHOD FOR THE PRODUCTION THEREOF AND THEIR USE FOR THE PRODUCTION OF POLYURETHANE |
| DE3529530A1 (en) * | 1985-08-17 | 1987-02-26 | Basf Ag | USE OF STABLE DISPERSIONS OF SOLID, FINE-PARTICULATE POLYISOCYANATES IN PIGMENT PRINTING PASTE AND FIBER FLOATING |
| DE4022602A1 (en) * | 1990-07-16 | 1992-01-23 | Basf Ag | WAITING PREPARATIONS OF COPOLYMER LIQUIDS AND POLYISOCYANATE DISPERSIONS |
| FR2730737B1 (en) * | 1995-02-21 | 1997-06-06 | Rhone Poulenc Chimie | COMPOSITION USEFUL FOR PAINT BASED ON MIXTURE OF EMULSION (S) AND DISPERSION (S) OF POLYOL POLYMER AND COATING (S) THEREOF |
| US5523344A (en) * | 1995-06-07 | 1996-06-04 | H. B. Fuller Licensing & Financing, Inc. | Water-based adhesive formulation having enhanced characteristics |
-
1998
- 1998-12-21 EP EP98811247A patent/EP1013690A1/en not_active Withdrawn
-
1999
- 1999-12-01 AU AU12571/00A patent/AU1257100A/en not_active Abandoned
- 1999-12-01 EP EP99955639A patent/EP1153056A1/en not_active Withdrawn
- 1999-12-01 WO PCT/CH1999/000577 patent/WO2000037526A1/en not_active Application Discontinuation
- 1999-12-01 MX MXPA01006321A patent/MXPA01006321A/en unknown
- 1999-12-01 CA CA002355908A patent/CA2355908A1/en not_active Abandoned
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2400104A (en) * | 2003-04-03 | 2004-10-06 | Bostik Findley Ltd | Adhesive comprising surface-protected polyisocyanate particles |
| US7235152B2 (en) | 2003-04-03 | 2007-06-26 | Bostik-Findley Limited | Storage stable, thermofusible, thermosetting adhesive paste |
| GB2400104B (en) * | 2003-04-03 | 2007-10-10 | Bostik Findley Ltd | Storage stable adhesive paste compositions |
| US7498380B2 (en) | 2004-05-28 | 2009-03-03 | Bayer Materialscience Ag | Adhesives |
| US11802226B2 (en) | 2013-07-30 | 2023-10-31 | H.B. Fuller Company | Polyurethane adhesive film |
| US9944834B2 (en) | 2014-12-15 | 2018-04-17 | H.B. Fuller Company | Reactive film adhesives with enhanced adhesion to metallic surfaces |
| US9957427B2 (en) | 2014-12-15 | 2018-05-01 | H.B. Fuller Company | Reactive adhesive with enhanced adhesion to metallic surfaces |
Also Published As
| Publication number | Publication date |
|---|---|
| AU1257100A (en) | 2000-07-12 |
| MXPA01006321A (en) | 2002-04-24 |
| EP1013690A1 (en) | 2000-06-28 |
| WO2000037526A1 (en) | 2000-06-29 |
| EP1153056A1 (en) | 2001-11-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 20031201 |