WATER-SWELLABLE MOISTURE CURING ONE-COMPONENT POLYURETHANE SEALANT

Abstract

A one-component moisture curing composition and a method for sealing construction joints against penetration of water. The one-component moisture curing composition includes at least one isocyanate-functional polyurethane polymer, at least one inorganic swelling agent selected from the group including aluminum sulfate and magnesium sulfate, and at least one hydrophilic aldimine of formula (I).

Claims

1. A one-component moisture curing composition comprising: a) at least one isocyanate-functional polyurethane polymer, b) at least one inorganic swelling agent selected from the group consisting of aluminum sulfate and magnesium sulfate, and c) at least one hydrophilic aldimine of the formula (I); ##STR00007## wherein m is 2 or 3 A is a divalent or trivalent hydrocarbyl moiety containing ether groups and having average molecular weight in the range from 600 to 4,000 g/mol, and Z is a monovalent C.sub.3 to C.sub.30 hydrocarbyl moiety optionally containing ether, carbonyl, ester, amido, urethane, urea or tertiary amino groups.

2. The one-component moisture curing composition according to claim 1, wherein the total amount of the at least one inorganic swelling agent is in the range of 1.0-35.0% by weight, based on the total weight of the one-component composition.

3. The one-component moisture curing composition according to claim 1, wherein A is a divalent or a trivalent hydrocarbyl moiety having a content of ethylene oxide units of at least 50.0% by weight, based on the weight of A.

4. The one-component moisture curing composition according to claim 1, wherein the hydrophilic aldimine of formula (I) has a content of ethylene oxide units of at least 30.0% by weight, based on the weight of the hydrophilic aldimine.

5. The one-component moisture curing composition according to claim 1, wherein the at least one hydrophilic aldimine of formula (I) is present in an amount of 1.0-30.0% by weight, based on the total weight of the one-component moisture curing composition.

6. The one-component moisture curing composition according to claim 1, wherein Z is a substituted or non-substituted aromatic moiety or the hydrophilic aldimine of the formula (I) is a hydrophilic aldimine of the formula (I a), ##STR00008## wherein R.sup.1 and R.sup.2 are the same or different C.sub.1 to C.sub.12 linear or branched alkyls, or are joined together to form a divalent linear or branched C.sub.4 to C.sub.12 hydrocarbyl moiety which is part of a 5- to 8-membered carbocyclic ring; R.sup.3 is hydrogen or a linear or branched C.sub.1 to C.sub.12 alkyl or arylalkyl or alkoxycarbonyl; and ##STR00009## X is a monovalent moiety of the formulae wherein R.sup.4 and R.sup.5 are the same or different linear or branched C.sub.1 to C.sub.20 alkyls or cycloalkyls or aralkyls optionally containing ether groups, or are joined together to form a divalent linear or branched C.sub.4 to C.sub.12 hydrocarbyl moiety which is part of a 5- to 8-membered heterocyclic ring which, besides the nitrogen atom, may contain an ether or thioether or tertiary amino group, and R.sup.6 is hydrogen or a monovalent C.sub.1 to C.sub.20 hydrocarbyl moiety optionally containing ether, carbonyl or ester groups.

7. The one-component moisture curing composition according to claim 1, wherein the hydrophilic aldimine of formula (I) is selected from the group consisting of N,N-bis(2,2-dimethyl-3-(N-morpholino)-propylidene)-polyoxyethylene-polyoxypropylenediamines with an average molecular weight in the range of 1,000 to 3,000 g/mol, N,N-bis(2,2-dimethyl-3-acetoxypropylidene)-polyoxyethylene-polyoxypropylenediamines with an average molecular weight in the range of 1,000 to 3,000 g/mol, and N,N-bis(2,2-dimethyl-3-lauroyl-oxypropylidene)-polyoxyethylene-polyoxypropylenediamines with an average molecular weight in the range of 1,000 to 3,000 g/mol.

8. The one-component moisture curing composition according to claim 1, wherein the ratio between the total number of isocyanate-reactive groups from aldimines to the number of isocyanate groups in the one-component composition is in the range of 0.3 to 1.0.

9. The one-component moisture curing composition according to claim 1, wherein the at least one isocyanate-functional polyurethane polymer is present in an amount of 10-90% by weight, based on the total weight of the one-component composition.

10. The one-component moisture curing composition according to claim 1 further comprising at least one hydrophobic aldimine of formula (II); ##STR00010## wherein m is 2 or 3 B is a divalent or trivalent hydrocarbyl moiety having average molecular weight in the range from 28 to 10,000 g/mol, and Z is a monovalent C.sub.3 to C.sub.30 hydrocarbyl moiety optionally containing ether, carbonyl, ester, amido, urethane, urea or tertiary amino groups.

11. The one-component moisture curing composition according to claim 10, wherein the hydrophobic aldimine of formula (II) has a content of ethylene oxide units of not more than 35.0% by weight, based on the weight of the hydrophobic aldimine.

12. The one-component moisture curing composition according to claim 1 containing less than 5.0% by weight of hydrophilic isocyanate-functional polyurethane polymers.

13. A method of sealing comprising steps of: i) applying a composition according to claim 1 to between substrate S1 and S2, ii) curing the composition by contact with moisture to form a water-swellable sealant between the substrates 51 and S2, the substrates being of same material or of different material.

14. A sealed article produced by using the method according to claim 13.

15. The sealed article according to claim 14, wherein the article is a built structure in construction or civil engineering or a part thereof

Description

DETAILED DESCRIPTION OF THE INVENTION

[0019] The subject of the present invention is a one-component moisture curing composition comprising:

a) at least one isocyanate-functional polyurethane polymer,
b) at least one inorganic swelling agent selected from the group consisting of aluminum sulfate and magnesium sulfate, and
c) at least one hydrophilic aldimine of the formula (I);

##STR00001##

wherein
m is 2 or 3,
A is a divalent or trivalent hydrocarbyl moiety containing ether groups and having average molecular weight in the range from 600 to 4,000 g/mol, preferably from 900 to 2,500 g/mol, and
Z is a monovalent C.sub.3 to C.sub.30 hydrocarbyl moiety optionally containing ether, carbonyl, ester, amido, urethane, urea or tertiary amino groups.

[0020] In this document, the term one-component moisture curing composition or one-part moisture curing composition refers to compositions, which are contained in a single moisture-tight container, has certain storage stability and which cures when exposed to moisture.

[0021] In this document, the term latent hardener refers to compounds containing at least two reactive groups, which are reactive towards isocyanate groups, the reactivity of which the at least two reactive groups is blocked and is activatable with moisture. The reactive groups of the latent hardener include all reactive groups, which show reactivity toward isocyanate groups after the activation with moisture.

[0022] In this document, the prefix poly in substance designations such as polyol or polyisocyanate refers to substances which in formal terms contain two or more per molecule of the functional group that occurs in their designation. A polyol, for example, is a compound having two or more hydroxyl groups, and a polyisocyanate is a compound having two or more isocyanate groups.

[0023] In this document the terms ethylene oxide moiety, ethylene oxide group and ethylene oxide unit are used interchangeably, and refer to moieties of the formula (CH.sub.2CH.sub.2O), excluding such moieties that form part of a 1,2-propylene oxide moiety, described by the formula (CH.sub.2CH(CH.sub.3)O).

[0024] In this document, the term polyurethane polymer refers to polymers prepared by so called diisocyanate polyaddition process. Examples of polyurethane polymers are polyether polyurethanes, polyester polyurethanes, and polyisocyanurates.

[0025] The term polyurethane prepolymer refers to polyurethane polymers comprising one or more unreacted isocyanate groups. The polyurethane prepolymers are obtained by reacting excess of polyisocyanates with polyols and they are polyisocyanates themselves. The terms isocyanate-functional polyurethane polymer and polyurethane prepolymer are used interchangeably.

[0026] In this document, the term hydrophilic polymer refers to a polymer having hydrophilic moieties which enable the polymer to be water soluble, miscible or capable of forming an emulsion or paste when mixed with water. The hydrophilic moieties can be referred to as hydrophilic segments, centers or functional groups depending on the nature of the hydrophilic moiety. Preferred hydrophilic moieties include ether functions and ionic groups.

[0027] In this document, the term molecular weight refers to the molar mass (g/mol) of a molecule or a part of a molecule, also referred to as moiety. The term average molecular weight refers to number average molecular weight (M.sub.n) of an oligomeric or polymeric mixture of molecules or moieties.

[0028] In this document, the term shelf life stability refers to the ability of a composition to be stored at room temperature in a suitable container under exclusion of moisture for a certain time interval, in particular several months, without undergoing significant changes in application or end-use properties.

[0029] In this document, an amine or an isocyanate is called aliphatic when its amine group or its isocyanate group, respectively, is directly bound to an aliphatic, cycloaliphatic or arylaliphatic moiety. The corresponding functional group is therefore called an aliphatic amine or an aliphatic isocyanate group, respectively.

[0030] In this document, an amine or an isocyanate is called aromatic when its amine group or its isocyanate group, respectively, is directly bound to an aromatic moiety. The corresponding functional group is therefore called an aromatic amine or an aromatic isocyanate group, respectively.

[0031] In this document, the term primary amine group refers to an NH.sub.2-group bound to an organic moiety, and the term secondary amine group refers to a NH-group bound to two organic moieties which together may be part of a ring.

[0032] In this document, the term room temperature refers to a temperature of ca. 23 C.

[0033] A dashed line in the chemical formulas of this document represents the bonding between a moiety and the corresponding rest of the molecule.

[0034] The one-component moisture curing composition of the present invention comprises at least one isocyanate-functional polyurethane polymer.

[0035] A suitable isocyanate-functional polyurethane polymer may be obtained from the reaction of at least one polyisocyanate with at least one polyol, whereby the isocyanate groups are in stoichiometric excess over hydroxyl groups. The reaction can be carried out via known methods, preferably at temperatures of between 50 and 100 C., optionally in the presence of a catalyst. Preferably, the polyisocyanate is used in such an amount that the ratio of the isocyanate groups to hydroxyl groups in the reaction mixture is in the range of 1.2 to 3.0, more preferably of 1.5 to 3.0. The polyisocyanate and the polyol may optionally be reacted in the presence of a plasticizer and/or a solvent, which are free from isocyanate-reactive groups.

[0036] Preferably, the isocyanate-functional polyurethane polymer has a free NCO-group content in the range of 0.5 to 10.0% by weight, more preferably of 1.0 to 5.0% by weight.

[0037] Preferably, the isocyanate-functional polyurethane polymer has an average molecular weight in the range of 1,000 to 20,000 g/mol, more preferably in the range of 2,000 to 10,000 g/mol.

[0038] Preferably the isocyanate-functional polyurethane polymer has an average isocyanate functionality in the range of 1.5 to 3.0, more preferably of 1.6 to 2.5.

[0039] Suitable polyols for preparing the isocyanate-functional polyurethane polymer are polyether polyols, including those containing dispersed styrene-acrylonitrile (SAN), acrylonitrile-methylmethacrylate, or urea particles, further polyester polyols such as products of the polycondensation reaction of diols or triols with lactones or dicarboxylic acids or their esters or anhydrides, further polycarbonate polyols, block copolymer polyols with at least two different blocks of polyether, polyester or polycarbonate units, polyacrylate and polymethacrylate polyols, polyhydroxy-functional fats and oils, especially natural fats and oils, and polyhydrocarbon polyols, such as polyhydroxy-functional polyolefins.

[0040] Preferred polyols are diols and triols with an average molecular weight in the range of 500 to 10,000 g/mol, particularly in the range of 1,000 to 5,000 g/mol.

[0041] Preferred polyols are polyether polyols, polyester polyols, polycarbonate polyols and polyacrylate polyols.

[0042] Particularly preferred polyols are polyether polyols, particularly polyoxyalkylenepolyols.

[0043] Polyoxyalkylenepolyols are products of the polymerziation of ethylene oxide, 1,2-propylene oxide, 1,2- or 2,3-butylene oxide, oxetane, tetrahydrofuran or mixtures thereof, optionally polymerized using a starter molecule with two or more active hydrogen atoms, such as water, ammonia or compounds with several OH- or NH-groups, such as 1,2-ethanediol, 1,2- and 1,3-propanediol, neopentylglycol, diethyleneglycol, triethyleneglycol, the isomeric dipropylene-glycols and tripropyleneglycols, the isomeric butanediols, pentanediols, hexanediols, heptanediols, octanediols, nonanediols, decanediols, undecanediols, 1,3- and 1,4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol, aniline, as well as mixtures of the above-mentioned compounds.

[0044] Preferred are both polyoxyalkylenepolyols with a low degree of unsaturation (measured according to ASTM D-2849-69 and indicated in milliequivalents of unsaturation per gram of polyol (meq/g)), obtainable, for example, by using so-called double metal cyanide complex catalysts (DMC catalysts), and polyoxyalkylenepolyols with a higher degree of unsaturation, obtainable, for example, by using anionic catalysts such as NaOH, KOH, CsOH or alkali alcoholates. Particularly preferred polyoxyalkylenepolyols are polymerization products of ethylene oxide and/or propylene oxide.

[0045] More preferred are polyoxypropylenepolyols and so-called ethylene oxide end-capped polyoxypropylenepolyols. The latter are specific polyoxypropylene-polyoxyethylenepolyols obtainable by post-ethoxylating pure polyoxypropylenepolyols, thus featuring primary hydroxyl groups.

[0046] Particularly preferred are polyoxypropylenediols and -triols and ethylene oxide end-capped polyoxypropylenediols and -triols with an average molecular weight in the range of 500 to 6,000 g/mol, particularly in the range of 1,000 to 5,000 g/mol.

[0047] Further particularly preferred polyols are polycarbonate polyols, particularly products of the polycondensation of dialkyl carbonates, diaryl carbonates or phosgene with diols or triols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,12-octadecanediol, 1,4-cyclohexane dimethanol, dimeric fatty acid diol (dimeryl diol), hydroxypivalic neopentylglycol ester, glycerol and 1,1,1-trimethylolpropane.

[0048] Along with the above-mentioned polyols, small amounts of low molecular weight divalent or multivalent alcohols can be used, such as 1,2-ethanediol, 1,2-propanediol, neopentyl glycol, dibromoneopentyl glycol, diethylene glycol, triethylene glycol, the isomeric dipropylene glycols and tripropylene glycols, the isomeric butanediols, pentanediols, hexanediols, heptanediols, octanediols, nonanediols, decanediols, undecanediols, 1,3- and 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, dimer fatty alcohols, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol, pentaerythritol, sugar alcohols, such as xylitol, sorbitol or mannitol, sugars, such as saccharose, other polyhydric alcohols, low molecular weight alkoxylation products of the above-mentioned divalent or multivalent alcohols, as well as mixtures of the above-mentioned alcohols.

[0049] Preferably the isocyanate-functional polyurethane polymer is prepared from a polyol mixture containing at least 50% by weight, more preferably at least 80% by weight, and most preferably at least 90% by weight, of polyether polyols.

[0050] Suitable polyisocyanates to obtain the isocyanate-functional polyurethane polymer include: [0051] Aliphatic polyisocyanates, particularly 1,4-tetramethylene diisocyanate, 2-methylpentamethylene-1,5-diisocyanate, 1,6-hexanediisocyanate (HDI), 2,2,4- and 2,4,4-trimethyl-1,6-hexanediisocyanate (TMDI), 1,10-decane-diisocyanate, 1,12-dodecanediisocyanate, lysine or lysine ester diisocyanate, cyclohexane-1,3- and -1,4-diisocyanate, 1-methyl-2,4- and -2,6-diisocyanatocyclohexane and any mixtures of these isomers (H6TD1), 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (isophoronediisocyanate or IPDI), perhydro-2,4- and -4,4-diphenylmethane diisocyanate (H12MDI), 1,4-diisocyanato-2,2,6-trimethylcyclohexane (TMCDI), 1,3- and 1,4-bis-(isocyanatomethyl)cyclohexane, m- and p-xylylene diisocyanate (m- and p-XDI), m- and p-tetramethyl-1,4-xylylene diisocyanate (m- and p-TMXDI), bis-(1-isocyanato-1-methylethyl)naphthalene, dimer or trimer fatty acid isocyanates, such as 3,6-bis-(9-isocyanatononyl)-4,5-di-(1-heptenyl)cyclohexene (dimeryl diisocyanate), and ,,,,,-hexamethyl-1,3,5-mesitylene triisocyanate. Preferred thereof are HDI, TMDI, IPDI and H12MDI, in particular HDI and IPDI, most preferred is IPDI. [0052] Aromatic polyisocyanates, particularly 4,4-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate and/or 2,2-diphenylmethane diisocyanate and any mixtures of these isomers (MDI), 2,4- and/or 2,6-toluylene diisocyanate and any mixtures of these isomers (TDI), 1,3- and 1,4-phenylene diisocyanate, 2,3,5,6-tetramethyl-1,4-diisocyanatobenzene, naphthalene-1,5-diisocyanate (NDI), 3,3-dimethyl-4,4-diisocyanatodiphenyl (TODD, di-anisidine diisocyanate (DADI), 1,3,5-tris(isocyanatomethyl)benzene, tris-(4-isocyanatophenyl)methane and tris-(4-isocyanatophenyl)thiophosphate. Preferred thereof are MDI and TDI.

[0053] It can be advantageous to use mixtures of MDI with oligomers or polymers or derivatives of MDI, preferably so-called modified MDI containing carbodiimides or uretonimines of MDI, which are commercially available, for example, as Desmodur CD (from Covestro), Lupranate MM 103 (from BASF) or Isonate M 143 and Isonate M 309 (from Dow), as well as so-called polymeric MDI or PMDI representing mixtures of MDI with homologues of MDI, preferably with a low content of MDI homologues, such as Desmodur VL50 (from Covestro) and Voranate M 2940 (from Dow). A particularly preferred form of MDI is an MDI isomer mixture comprising 4,4-diphenylmethane diisocyanate and 2,4-diphenylmethane diisocyanate in about equal amounts, commercially available for example as Desmodur 2424 (from Covestro) or Lupranate MI (from BASF).

[0054] Preferably, the at least one inorganic swelling agent is present in the one-component moisture curing composition in an amount in the range of 1.0-35.0% by weight, more preferably 5.0-30.0% by weight, even more preferably 7.5-30.0% by weight, even more preferably 10.0-25.0% by weight, most preferably 12.5-22.5% by weight, based on the total weight of the one-component composition. It may also be preferable that the at least one swelling agent is present in the one-component moisture curing composition in an amount in the range of 1.0-25.0% by weight, more preferably 1.0-22.5% by weight, even more preferably 1.0-12.5% by weight, most preferably 1.0-10.0% by weight, based on the total weight of the one-component composition.

[0055] Preferably, the median particle size d.sub.50 of the inorganic swelling agent is not more than 100 m, more preferably not more than 50 m, most preferably not more than 25 m. In particular, the median particle size d.sub.50 of the inorganic swelling agent can be in the range of 0.5-100.0 m, preferably 0.5-50.0 m, more preferably 1.0-25.0 m, most preferably 1.0-10.0 m.

[0056] The term median particle size d.sub.50 refers in this document to a particle size below which 50% of all particles by volume are smaller than the d.sub.50 value. The term particle size refers in this document to the area-equivalent spherical diameter of a particle. The particle size distribution can be measured by laser diffraction according to the method as described in standard ISO 13320:2009. A Mastersizer 2000 device (trademark of Malvern Instruments Ltd, GB) can be used in measuring particle size distribution.

[0057] The one-component moisture curing composition of the present invention further comprises at least one hydrophilic aldimine of formula (I).

##STR00002##

[0058] Preferably, A is a divalent or trivalent hydrocarbyl moiety having an average molecular weight in the range 600 to 4,000 g/mol, preferably from 900 to 2,500 g/mol and having a content of ethylene oxide units of at least 50% by weight, more preferably 50-95% by weight, most preferably 55-90% by weight, based on the weight of A.

[0059] According to one or more embodiments of the present invention, A is a divalent or a trivalent hydrocarbyl moiety having an average molecular weight in the range of 600 to 1,000 g/mol containing 50-70% by weight of ethylene oxide units and 30-50% by weight of 1,2-propylene oxide units, the proportions being based on the weight of A.

[0060] According to one or more embodiments of the present invention, A is a divalent or a trivalent hydrocarbyl moiety having an average molecular weight in the range of 1,000 to 2,500 g/mol containing 70-90% by weight of ethylene oxide units and 10-30% by weight of 1,2-propylene oxide units, the proportions being based on the weight of A.

[0061] Preferably, the hydrophilic aldimine of formula (I) has a content of ethylene oxide units of at least 30% by weight, more preferably at least 40% by weight, in particular 30-90% by weight, preferably 40-85% by weight, based on the weight of the hydrophilic aldimine.

[0062] One-component compositions comprising at least one isocyanate-functional polyurethane polymer and at least one hydrophilic aldimine of formula (I) having the ethylene oxide unit content in the above specified ranges have been found to form upon curing water swellable sealants having excellent swelling properties without the use of excessive amounts of inorganic swelling agents. Furthermore, such water-swellable sealants have been found to show decreased shrinkage and good mechanical stability.

[0063] Preferably, the at least one hydrophilic aldimine of formula (I) is present in an amount of 1.0-30.0% by weight, more preferably 2.0-25.0% by weight, even more preferably 3.0-20.0% by weight, most preferably 4.0-20.0% by weight, based on the total weight of the one-component moisture curing composition. Water-swellable sealants obtained upon curing of one-component compositions containing hydrophilic aldimines of formula (I) in the amount within the above cited ranges have been found to have excellent swelling properties, decreased shrinkage and good mechanical stability.

[0064] Preferably, Z is a substituted or non-substituted aromatic moiety or the hydrophilic aldimine of formula (I) is a hydrophilic aldimine of formula (I a),

##STR00003##

wherein
m is 2 or 3,
R.sup.1 and R.sup.2 are the same or different C.sub.1 to C.sub.12 linear or branched alkyls, or are joined together to form a divalent linear or branched C.sub.4 to C.sub.12 hydrocarbyl moiety which is part of a 5- to 8-membered carbocyclic ring,
R.sup.3 is hydrogen or a linear or branched C.sub.1 to C.sub.12 alkyl or arylalkyl or alkoxycarbonyl, and
X is a monovalent moiety of the formulae

##STR00004##

wherein
R.sup.4 and R.sup.5 are the same or different linear or branched C.sub.1 to C.sub.20 alkyls or cycloalkyls or aralkyls optionally containing ether groups, or are joined together to form a divalent linear or branched C.sub.4 to C.sub.12 hydrocarbyl moiety which is part of a 5- to 8-membered heterocyclic ring which, besides the nitrogen atom, may contain an ether or thioether or tertiary amino group, and
R.sup.6 is hydrogen or a monovalent C.sub.1 to C.sub.20 hydrocarbyl moiety optionally containing ether, carbonyl or ester groups.

[0065] One-component moisture curing compositions containing hydrophilic aldimines of formula (I a) have been found to cure without releasing significant amounts of carbon dioxide and to provide upon curing low odor or odorless water-swelling sealants having excellent swelling properties, decreased tendency for shrinkage in dry conditions and good mechanical stability.

[0066] Preferably, R.sup.1 and R.sup.2 are each methyl and R.sup.3 is hydrogen.

[0067] Preferably, R.sup.4 and R.sup.5 are each a linear or branched C.sub.1 to C.sub.8 alkyl or cycloalkyl or aralkyl optionally containing ether groups, or are joined together to form a divalent linear or branched C.sub.4 to C.sub.8 hydrocarbyl moiety which is part of a 5- to 8-membered heterocyclic ring which, besides the nitrogen atom, may contain an ether or thioether or tertiary amino group.

[0068] More preferably R.sup.4 and R.sup.5 are each a methoxyethyl group or are joined together to form, including the nitrogen atom, a morpholine or a 2,6-dimethylmorpholine ring.

[0069] Most preferably R.sup.4 and R.sup.5 form a morpholine ring together with the nitrogen atom.

[0070] Preferably R.sup.6 is a C.sub.1 to C.sub.11 alkyl, most preferably a methyl or a C.sub.11 alkyl.

[0071] Particularly preferred are hydrophilic aldimines of the formula (I a) wherein R.sup.1 and R.sup.2 are methyl, R.sup.3 is hydrogen and R.sup.4 and R.sup.5 form a morpholine ring together with the nitrogen atom.

[0072] Particularly preferred are further hydrophilic aldimines of the formula (I a) wherein R.sup.1 and R.sup.2 are methyl, R.sup.3 is hydrogen and R.sup.6 is a methyl or a C.sub.11 alkyl.

[0073] Particularly preferred hydrophilic aldimines of formula (I a) are N,N-bis(2,2-dimethyl-3-(N-morpholino)-propylidene)-polyoxyethylene-polyoxypropylenediamines with an average molecular weight in the range from 1,000 to 3,000 g/mol, N,N-bis(2,2-dimethyl-3-acetoxypropylidene)polyoxyethylene-polyoxypropylenediamines with an average molecular weight in the range of 1,000 to 3,000 g/mol and and N,N-bis(2,2-dimethyl-3-lauroyloxypropylidene)-polyoxyethylene-polyoxypropylenediamines with an average molecular weight in the range of 1,000 to 3,000 g/mol.

[0074] In particular, preferred hydrophilic aldimines of formula (I a) are N,N-bis(2,2-dimethyl-3-(N-morpholino)-propylidene)-polyoxyethylene-polyoxypropylenediamines, N,N-bis(2,2-dimethyl-3-acetoxypropylidene)polyoxyethylene-polyoxypropylenediamines, and N,N-bis(2,2-dimethyl-3-lauroyloxypropylidene)-polyoxyethylene-polyoxypropylenediamines containing at least at least 30% by weight, more preferably 30-90% by weight, most preferably 40-85% by weight of ethylene oxide units and having an average molecular weight in the range of 1,000 to 3,000 g/mol.

[0075] Such hydrophilic aldimines are based on aminated polyether polyols in the form of propoxylated polyoxyethylene diols, commercially available, for example, as Jeffamine ED-2003 (from Huntsman). One-component moisture curing compositions containing such hydrophilic aldimines have been found to cure without releasing significant amounts of carbon dioxide and to provide low odor or odorless water-swellable sealants having excellent swelling properties, decreased tendency for shrinkage in dry conditions and good mechanical stability.

[0076] The hydrophilic aldimines of the formulae (I) and (I a) are preferably available from a condensation reaction of at least one primary polyamine of the formula (IV) and at least one aldehyde of the formula (V).

##STR00005##

[0077] In the formulae (IV) and (V), m, A and Z have the already mentioned meanings.

[0078] For the condensation reaction, the aldehyde of the formula (V) is used stoichiometrically or in excess related to the primary amino groups of the primary polyamine of the formula (IV). The reaction can advantageously be conducted at a temperature in the range between 15 and 120 C., either in the presence of a solvent or without a solvent. The released water is being removed either azeotropically with a suitable solvent, or directly under vacuum.

[0079] Particularly suitable amines of the formula (IV) are hydrophilic polyoxyalkylenediamines and -triamines with an average molecular weight in the range of 600 to 3,000 g/mol, which are commercially available as Jeffamine ED-600, Jeffamine ED-900, Jeffamine ED-2003 (from Huntsman) as well as the corresponding grades from BASF or Nitroil, and further hydrophilic diamines derived from propoxylated polyoxyethylene diols.

[0080] Suitable aldehydes of the formula (V) are formaldehyde, acetaldehyde, propanal, 2-methylpropanal, butanal, 2-methylbutanal, 2-ethylbutanal, pentanal, 2-methylpentanal, 3-methylpentanal, 4-methylpentanal, 2,3-dimethylpentanal, hexanal, 2-ethylhexanal, heptanal, octanal, nonanal, decanal, undecanal, 2-methylundecanal, dodecanal, methoxy acetaldehyde, cyclopropane carboxaldehyde, cyclopentane carboxaldehyde, cyclohexane carboxaldehyde; 2,2-dimethyl-3-phenylpropanal, 1-naphthaldehyde, benzaldehyde or substituted benzaldehydes, in particular benzaldehydes substituted with alkyl groups, in particular alkyl groups having 10 to 14 C atoms.

[0081] Particularly suitable aldehydes of the formula (V) are isobutyraldehyde, 2-ethylhexanal, pivalaldehyde, 2,2-diethylbutanal, benzaldehyde, 2,2-dimethyl-3-(N,N-bis(methoxyethyl))amino-propanal, 2,2-dimethyl-3-(N-morpholino)-propanal, 2,2-dimethyl-3-(N-(2,6-dimethyl)morpholino)-propanal, 2,2-dimethyl-3-acetoxypropanal, and 2,2-dimethyl-3-lauroyloxypropanal.

[0082] Preferred thereof are benzyldehyde, 2,2-dimethyl-3-(N,N-bis(methoxyethyl))amino-propanal, 2,2-dimethyl-3-(N-morpholino)-propanal, 2,2-dimethyl-3-(N-(2,6-dimethyl)morpholino)-propanal, 2,2-dimethyl-3-acetoxypropanal, and 2,2-dimethyl-3-lauroyloxypropanal. Particularly preferred are 2,2-dimethyl-3-(Nmorpholino)-propanal, 2,2-dimethyl-3-acetoxypropanal, and 2,2-dimethyl-3-lauroyloxypropanal.

[0083] Preferably, the ratio between the total number of isocyanate-reactive groups from aldimines to the number of isocyanate groups in the one-component composition is in the range of 0.3 to 1.0, preferably 0.4 to 0.9.

[0084] Preferably, the at least one isocyanate-functional polyurethane polymer is present in an amount of 10 to 90% by weight, more preferably 30-80% by weight, most preferably 50-70% by weight, based on the total weight of the one-component composition.

[0085] According to one or more embodiments, the one-component moisture curing composition further comprises at least one hydrophobic aldimine of formula (II)

##STR00006##

wherein
B is a divalent or trivalent hydrocarbyl moiety having average molecular weight in the range from 28 to 10,000 g/mol, preferably from 76 to 6,000 g/mol and m and Z have the already mentioned meanings.

[0086] The hydrophobic aldimines of the formula (II) is preferably available from a condensation reaction of at least one primary polyamine of the formula (IV) and at least one aldehyde of the formula (V). [0087] Suitable amines of the formula (IV) for the preparation of a hydrophobic aldimine of formula (II) are aliphatic, cycloaliphatic, or arylaliphatic diamines, in particular 1,2-ethanediamine, 1,2-propane diamine, 1,3-propanediamine, 2,2-dimethyl-1,3-propanediamine, 1,3-butanediamine, 1,4-butanediamine, 1,3-pentanediamine (DAMP), 1,5-pentanediamine, 1,5-diamino-2-methylpentane (MPMD), 2-butyl-2-ethyl-1,5-pentanediamine (C11-neodiamine),1,6-hexanediamine, 2,5-dimethyl-1,6-hexanediamine, 2,2(4),4-trimethylhexamethylenediamine (TMD), 1,7-heptanediamine, 1,8-octanediamine, 4-aminomethyl-1,8-octanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,2-,1,3- and 1,4-diaminocyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane (isophorondiamine), 4(2)-methyl-1,3-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane, 2,5(2,6)bis(aminomethyl)bicyclo[2.2.1]heptane (NBDA), 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0.sup.2,6]decane, 1,4-diamino-2,2,6-trimethylcyclohexane (TMCDA), 1,3-bis(aminomethyl)benzene, 1,4-bis(aminomethyl)benzene; [0088] Aromatic diamines, in particular 1,3- or 1,4-phenylene diamine, 2,4(6)toluylene diamine, and 4,4-, 2,4- and 2,2-diaminodiphenylmethane; [0089] Ether group containing aliphatic diamines, in particular bis(2-aminoethyl)ether, 3,6-dioxaoctane-1,8-diamine, 4,7-dioxadecane-1,10-diamine, 4,7-dioxadecane-2,9-diamine, 4,9-dioxadodecane-1,12-diamine, 5,8-dioxadodecane-3,10-diamine, 4,7,10-trioxatridecane-1,13-diamine and higher oligomers of these diamines as well as polyoxyalkylenedi- and triamines having a molecular weight up to 6,000 g/mol, in particular the ones, which are commercially available from Huntsman as Jeffamine D-230, D-400, D-2000, D-4000, T-403 and T-5000 as well as the similar compounds available from BASF or Nitroil.

[0090] Preferably, the hydrophobic aldimine of formula (II) has a content of ethylene oxide units of not more than 35% by weight, more preferably not more than 25% by weight, most preferably not more than 10% by weight, based on the weight of the hydrophobic aldimine. In particular, the hydrophobic aldimine of formula (II) has a carbon to oxygen ratio of at least 4:1, preferably at least 5:1.

[0091] Preferably, the at least one hydrophobic aldimine of formula (II) is present in an amount of 0.5-20.0% by weight, more preferably 0.5-15.0% by weight, even more preferably 1.0-12.5% by weight, most preferably 1.0-10.0% by weight, based on the total weight of the one-component moisture curing composition.

[0092] According to one or more embodiments, the at least one hydrophilic aldimine of formula (I) is present in an amount of 0.5-20.0% by weight, preferably 0.5-15.0% by weight, more preferably 1.0-10.0% by weight, most preferably 1.0-7.5 and the at least one hydrophobic aldimine of formula (II) is present in an amount of 0.5-20.0% by weight, preferably 0.5-15.0% by weight, more preferably 1.0-10.0% by weight, most preferably 1.0-7.5% by weight, all proportions being based on the total weight of the one-component moisture curing composition.

[0093] Preferably, the one-component moisture curing composition contains less than 10.0% by weight, preferably less than 5.0% by weight, most preferably less than 1.0% by weight, of hydrophilic isocyanate-functional polyurethane polymers. The term hydrophilic isocyanate-functional polyurethane polymer refers in this document to isocyanate-functional polyurethane polymers having hydrophilic moieties which enable the polymer to be water soluble, miscible or capable of forming an emulsion or paste when mixed with water. The hydrophilic moieties can be referred to as hydrophilic segments, centers or functional groups depending on the nature of the hydrophilic moiety. Preferred hydrophilic moieties include ether functions and ionic groups.

[0094] The hydrophilic isocyanate-functional polyurethane polymers can be obtained, for example, from reaction of polyisocyanates with hydrophilic polyols or from reaction of hydrophilic polyisocyanates with polyols.

[0095] Hydrophilic polyols include, for example, polyhydroxy compounds containing polyoxyalkylene groups. Examples thereof include ethoxylated and mixed ethoxylated and propoxylated polyhydroxy compounds as well as dioxolane and dioxane reacted polyhydroxy compounds. Suitable hydrophilic polyols have a carbon to oxygen ratio of not more than 4:1, preferably not more than 3:1, more preferably in the range of 3:1 to 1.5:1.

[0096] Preferably, the hydrophilic polyol has a content of ethylene oxide units of at least 25% by weight, preferably at least 30% by weight, most preferably at least 40% by weight, based on the weight of the polyol. In particular, preferred hydrophilic polyols have an average hydroxyl functionality of at least 1.5, preferably between 1.6 and 10, more preferably between 1.7 and 6 and a content of ethylene oxide units of at least 25% by weight, preferably at least 30% by weight, most preferably at least 40% by weight, based on the weight of the polyol.

[0097] The hydrophilic polyols include, in particular, hydrophilic polyether polyols, which can be obtained in conventional manner by reacting ethylene oxide or mixtures of ethylene oxide and propylene oxide simultaneously and/or sequentially in any order with an initiator having 2 to 8 active hydrogen atoms, such as water, ethylene glycol, propylene glycol, butanediol, glycerol, trimethyol propane, ethylene diamine, triethanolamine, sucrose and sorbitol. In particular hydrophilic polyether polyols have an average molecular weight of at least 400 g/mol, preferably in the range from 500 to 10,000 g/mol, more preferably from 500 to 5,000 g/mol.

[0098] According to one or more embodiments, the one-component moisture curing composition is free of hydrophilic isocyanate-functional polyurethane polymers.

[0099] Besides the ingredients already mentioned, the one-component moisture curing composition can comprise further components.

[0100] The one-component moisture curing composition preferably comprises a filler, particularly calcium carbonate (chalk), barium sulfates (barytes), slate, silicates (quartz), magnesiosilicates (talc) and alumosilicates (clay, kaolin). These fillers may or may not carry a surface coating, e.g. a stearate or a siloxane coating. Such fillers can increase strength and durability of the water-swellable sealant.

[0101] The one-component moisture curing composition preferably comprises at least one metal-based catalyst. Preferred metal-based catalysts are dialkyltin complexes, particularly dibutyltin(IV) or dioctyltin(IV) carboxylates or acetoacetonates, such as dibutyltindilaurate (DBTDL), dibutyltindiacetylacetonate, dioctyltindilaurate (DOTDL), further bismuth(III) complexes such as bismuthoctoate or bismuthneodecanoate, zinc(II) complexes, such as zincoctoate or zincneodecanoate, and zirconium(IV) complexes, such as zirconiumoctoate or zirconiumneodecanoate. Such catalysts can accelerate the reaction of the isocyanate groups.

[0102] The one-component moisture curing composition preferably comprises at least one acid catalyst. Preferred acid catalysts are carboxylic acids and sulfonic acids, particularly aromatic carboxylic acids such as benzoic acid or salicylic acid. Such catalysts can accelerate the hydrolysis of aldimino groups.

[0103] The one-component moisture curing composition preferably comprises at least one pigment. Preferred pigments are titanium dioxide, iron oxides and carbon black. The pigment defines the color of the sealant, helps to develop strength and can improve durability, particularly UV-stability.

[0104] The one-component moisture curing composition may comprise at least one polyisocyanate crosslinker. Preferred polyisocyanate crosslinkers are oligomers and similar derivatives from diisocyanates such as MDI, TDI, HDI and IPDI. Preferred aliphatic polyisocyanate crosslinkers are HDI-biurets, such as Desmodur N 100 and N 3200 (from Covestro), Tolonate HDB and HDBLV (from Vencorex) and Duranate 24A-100 (from Asahi Kasei); HDIisocyanurates, such as Desmodur N 3300, N 3600 and N 3790 BA (from Covestro), Tolonate HDT, HDT-LV and HDT-LV2 (from Vencorex), Duranate TPA-100 and THA-100 (from Asahi Kasei) and Coronate HX (from Nippon Polyurethane); HDI-uretdiones such as Desmodur N 3400 (from Covestro); HDI-iminooxadiazinediones such as Desmodur 3900 (from Covestro); HDI-allophanates such as Desmodur VP LS 2102 (from Coverstro) and Basonat HA 100, HA 200 and HA 300 (from BASF); IPDI-isocyanurates such as Desmodur Z 4470 (from Covestro) and Vestanat T1890/100 (from Evonik); mixed isocyanurates based on IPDI/HDI, such as Desmodur NZ 1 (from Covestro). Preferred aromatic polyisocyanate crosslinkers are TDI-oligomers such as Desmodur IL (from Covestro); modified MDI containing carbodiimides or uretonimines of MDI such as the already mentioned ones; polymeric MDI or PMDI such as the already mentioned ones as well as Desmodur VL, VL R10, VL R20 (from Covestro), Voranate M 220, M 229 and M 580 (from Dow) or Lupranate M 10 R, M 20 S, M 50, M 70 R, and M 200 R (from BASF). Mixed aromatic/aliphatic polyisocyanate crosslinkers may also be used, in particular isocyanurates based on TDI/HDI, such as Desmodur HL (from Covestro).

[0105] Aliphatic polyisocyanate crosslinkers are particularly preferred in one-component moisture curing compositions containing aliphatic isocyanate-functional polyurethane polymers. Particularly preferred are IPDI-isocyanurates and mixed isocyanurates containing IPDI.

[0106] Aromatic polyisocyanate crosslinkers are particularly preferred in one-component moisture curing compositions containing aromatic isocyanate-functional polyurethane polymers.

[0107] When using such further ingredients it is advantageous to ensure that they do not strongly impair the shelf life stability of the one-component moisture curing composition, i.e. do not massively trigger reactions leading to crosslinking of the polyurethane prepolymer during storage. In particular these further ingredients should not contain any water above trace quantities. It can be advantageous to dry ingredients physically or chemically before use.

[0108] The one-component moisture-curing composition may be prepared by mixing all ingredients under exclusion of moisture to obtain a homogeneous paste. It may be stored in a suitable moisture-tight container, particularly a bucket, a drum, a hobbock, a bag, a sausage, a cartridge, a can or a bottle.

[0109] Another subject of the present invention is a method of sealing comprising steps of:

i) applying a one-component moisture curing composition according to the present invention to between substrates S1 and S2,
ii) curing the composition by contact with moisture to form a water-swellable sealant between the substrates S1 and S2, the substrates being of same material or of different material.

[0110] The curing of the one-component composition starts when it gets in contact with moisture, typically atmospheric moisture. The curing process works by chemical reaction. The aldimino groups are activated with moisture and then react with isocyanate groups. On activation, each aldimino group forms a primary amino group. Furthermore, the isocyanate groups can also react directly with moisture. As a result of these reactions, the composition cures to a water-swellable material, which is a solid, elastic material with a capability to absorb and retain water. The curing process may also be called crosslinking. When contacted with water, the volume of the water-swellable material is increased due to the absorbed water and a swelling pressure is exerted on the surrounding surfaces, which results in further sealing of the space between the substrates against water penetration.

[0111] In the course of the curing reaction, the blocking agents of the aldimines, i.e. the aldehydes of formula (V), are released. These blocking agents, depending on their volatility and other factors such as their solubility in the one-component moisture curing composition, may evaporate from the composition during or after curing, or may remain in the cured composition. In the case of aldimines of the formula (I a), the released aldehydes are of low odor and of good compatibility with the polyurethane matrix of the one-component composition. Particularly 2,2-dimethyl-3-(N-morpholino)propanal has an excellent compatibility with the polyurethane matrix, and particularly 2,2-dimethyl-3-lauroyloxypropanal is odorless and remains almost completely in the composition, reducing odor, emission and shrinkage of the water swellable sealant.

[0112] Preferably, the water-swellable sealant has a water-absorption capacity of at least 2.5% by weight. The term water-absorption capacity refers in this document to the amount of water in weight percentage that the sealant is able to absorb while being stored immersed in water at a temperature of ca. 23 C. for a period of four days, the proportion being based on the weight of the sealant excluding the amount of the absorbed water. In particular, the water-swellable sealant can have a water absorption capacity of at least 5.0% by weight, preferably at least 10.0% by weight, most preferably at least 20.0% by weight of water. Preferably, the water-swellable sealant has a water absorption capacity of not more than 500.0% by weight, more preferably not more than 300% by weight, most preferably not more than 200% by weight.

[0113] Still another subject of the present invention is a sealed article produced by using the method of sealing according to the present invention.

[0114] Preferably the article is a built structure in construction or civil engineering or a part thereof.

Examples

Preparation of the Aldimines

[0115] Aldimine 1: N,N-bis(2,2-dimethyl-3-lauroyloxypropylidene)-3-aminomethyl-3,5,5-trimethylcyclohexylamine

[0116] 55.0 g (0.19 mol) distilled 2,2-dimethyl-3-lauroyloxy-propanal were placed in a round bottom flask under nitrogen atmosphere. Then 15.6 g (0.18 mol of N) 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane (IPDA; Vestamin IPD from Evonik, amine content 11.68 mmol N/g) were added slowly under good stirring, followed by removing the volatile contents at 80 C. and 10 mbar vacuum. The yield was 67.1 g of nearly colorless liquid with an amine content of 2.73 mmol N/g, corresponding to a calculated aldimine equivalent weight of approx. 366 g/Eq.

[0117] Aldimine 2: N,N-bis(2,2-dimethyl-3-lauroyloxypropylidene)-polyoxyethylene-polyoxypropylenediamine

[0118] 2000 g (ca. 2 mol N) polyoxyethylene-polyoxypropylenediamine (Jeffamine ED-2003 from Huntsman, amine content 1.00 mmol N/g) were molten at 50 C. and reacted with 612 g (2.15 mol) distilled 2,2-dimethyl-3-lauroyloxy-propanal under the same conditions as given for Aldimine 1. The yield was 2575 g of a nearly colourless liquid, which solidified to a waxy solid on standing at room temperature after several hours, with an amine content of 0.78 mmol N/g, corresponding to a calculated aldimine equivalent weight of approx. 1290 g/Eq.

[0119] Preparation of the Isocyanate-Functional Polyurethane Polymer

[0120] 500 g polyoxypropylene diol (Acclaim 4200 N from Covestro; OH number 28.1 mg KOH/g), 2000 g polyoxypropylenepolyoxyethylene triol (Caradol MD34-02 from Shell; OH number 35.0 mg KOH/g) and 245 g toluene diisocyanate (Desmodur T 80 P from Covestro) were reacted at 80 C. to yield an NCO-terminated polyurethane polymer with a free isocyanate group content of 1.88 percent by weight.

[0121] Preparation of One-Component Moisture Curing Compositions

[0122] For each one-component composition the ingredients given in Table 1 were mixed under exclusion of moisture in a sealed polypropylene beaker by means of a centrifugal mixer (SpeedMixer DAC 150, FlakTek Inc.) until a homogenous fluid was obtained.

[0123] The compositions were stored in tightly sealed, moisture proof cans, for 1-7 days before they were used for testing the swelling properties.

[0124] Swelling in Water

[0125] For the measurement of the swelling properties, cylindrical test specimens having dimensions of 42 mm (diameter)6 mm (height) were prepared from each tested composition. The test specimens were cured for 19 days at normal room temperature (23 C., 50% relative humidity). After the curing, the test specimens were stored in tap water at a temperature of 23 C. for 1-4 days. The swelling values presented in Tables 1 and 2 were determined as the percentage change in weight of the test specimen during the storing in water.

[0126] The compositions Ex-1 to Ex-11 are compositions according to the invention and the compositions Ref-1 to Ref-8 are comparative examples.

TABLE-US-00001 TABLE 1 wt.-% Ex-1 Ex-2 Ex-3 Ex-4 Ex-5 Ref-1 Ref-2 Ref-3 Ref-4 Ref-5 Ref-6 Prepolymer TS-21 25.5 25.5 25.5 25.5 25.5 35.0 25.5 20.0 35.0 35.0 35.0 MgSO.sub.4.sup.a 2.0 4.0 6.0 8.0 10.0 10.0 20.0 30.0 Aldimine 1 5.7 5.7 5.7 5.7 Aldimine 2 13.4 13.4 13.4 13.4 13.4 13.4 10.5 .sup.bJayflex DIDP 22.6 22.6 22.6 22.6 22.6 20.8 22.6 31.0 20.8 20.8 20.8 .sup.cAerosil 202 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 .sup.dOmyacarb 5GU 28.0 26.0 24.0 22.0 20.0 30.0 30.0 30.0 20.0 10.0 Salicylic acid (5 wt- 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 % in DOA.sup.e) Swelling 1 day 34% 46% 59% 73% 90% 1% 20% 15% 13% 13% 42% Swelling 2 days 46% 65% 86% 106% 132% 1% 27% 20% 20% 28% 68% Swelling 3 days 54% 78% 103% 132% 162% 1% 32% 22% 26% 38% 86% Swelling 4 days 56% 76% 108% 142% 174% 1% 35% 23% 33% 51% 105% Swelling 7 days 45% 66% 93% 128% 149% 1% 38% 24% 45% 77% 147% .sup.aLuvomag S700 grinded to a d.sub.50 median particle size of 5 m from Lehmann & Voss & Co .sup.bplasticizer product containing diisodecyl phthalate from ExxonMobil Chemical .sup.csurface-treated fumed silica from Evonik .sup.dcalcium carbonate from Bassermann minerals .sup.ebis (2-ethylhexyl) adipate from Eastman Chemical Company

TABLE-US-00002 TABLE 2 wt.-% Ex-6 Ex-7 Ex-8 Ex-9 Ex-10 Ex-11 Ref-7 Ref-8 Prepolymer TS-21 33.6 33.6 33.6 32.4 32.4 32.4 31.1 28.0 MgSO4a 20 16 12 16 14 12 Aldimine 1 4.8 4.8 4.8 4 4 4 3.35 1.5 Aldimine 2 2 2 2 4 4 4 5.5 9.9 .sup.bJayflex DIDP 21.1 21.1 21.1 21.1 21.1 21.1 21.55 22.1 .sup.cAerosil 202 8 8 8 8 8 8 8 8 .sup.dOmyacarb 5GU 10 14 18 14 16 18 30.0 30.0 Salicylic acid (5 wt-% in 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 DOA.sup.e) Swelling 1 day 27% 22% 17% 32% 29% 26% 2% 7% Swelling 2 days 44% 37% 29% 50% 47% 41% 2% 9% Swelling 3 days 58% 49% 38% 70% 54% 45% 3% 10% Swelling 4 days 70% 60% 47% 84% 66% 54% 3% 12% Swelling 7 days 102% 95% 69% 128% 117% 103% 4% 16% .sup.aLuvomag S700 grinded to a d.sub.50 median particle size of 5 m from Lehmann & Voss & Co .sup.bplasticizer product containing diisodecyl phthalate from ExxonMobil Chemical .sup.csurface-treated fumed silica from Evonik .sup.dcalcium carbonate from Bassermann minerals .sup.ebis (2-ethylhexyl) adipate from Eastman Chemical Company