NL9100120A - Internal emulsifier systems based on alkylene oxide units - for use in polyurethane coatings based on tetra:methyl:xylylene di:isocyanate - Google Patents

Abstract

Claimed is an internal emulsifier system based on alkylene oxide units, the emulsifier system being of formula (R1-(O-CH2-CHR2)a-O-CO)b-R3-(C-OO-R4)c (I), R7-(O-CH2-CHR8)d-O-CO-R9-CO-O-R10 (II) or (R12-(O-CH2-CHR13)e-O-CO-R14-CO-O)2-R15 (III); (a= 5-50; b= 1 or 2; c= 2; R1= 1-4C alkyl; R2= H or 1-4C alkyl; R3= 6-12C cycloalkyl or aryl; R4= -CH2-CH(OH)R5 (R5= 1-4C alkyl) or R4= -CH2-CH(OH)CH2OR6 (R6= 1-32C alkyl, 6-32C cycloalkyl or aryl); (d as a; R7 as R1; R8 as R2; R9 as R3; R10= -CH2-CH(OH)CH(OH)R11 (R11= H or 1-4C alkyl); (e= 100-500; R12 as R1; R13 as R2; R14 as R3; R15= -CH2-CH(OH)CHOR16OCH2CH(OH)-CH2- (-O-R16-O- = 6-75C (cyclo)aliphatic or aromatic epoxy resin backbone). Methods of prepn. of the emulsifier systems are also claimed, as are polyurethane dispersions contg. them, the prepn. of the dispersions contg. 5-50 wt.% emulsifier, their use, and coatings based on them.

Description

BUILT-IN EMULGATOR SYSTEM BASED ON ALKYLENE OXIDE UNITS

The invention relates to a buildable emulsifier system based on alkylene oxide units and the use of this system in non-ionic polyurethane dispersions.

Such emulsifier systems and their use in the preparation of non-ionic polyurethane dispersions are described in "Advances in Urethane Science and Technology", by Rosthauser and Nachtkamp in the article "Waterborne Polyurethanes" (KC Frisch, Vol 10, 1987, p. 128- 131). Non-ionic polyurethane dispersions can be prepared by first reacting a polyol, a diisocyanate and an emulsifier system into a precursor, then dispersing this precursor, followed by chain extension by water or diamine. As the emulsifier system, the reaction product of equimolar amounts of alkoxy polyethylene glycol, a diisocyanate such as, for example, isophorone diisocyanate or toluene diisocyanate and dihydroxyalkylamine, is used.

A drawback of said emulsifier system is that undesired compounds are also obtained in the preparation thereof because the diisocyanate reacts, instead of with only one equivalent, with two equivalents of alkoxy polyethylene glycol. Since in that case no reactive NCO groups are present, a compound is formed which, during the polyurethane dispersion preparation, does not function as a buildable emulsifier but as a loose emulsifier. The water resistance of coatings based on such polyurethane dispersions is adversely affected by this.

The invention is characterized in that the emulsifier system is a compound of formula (I), formula (II) or formula (III), wherein formula (I) is represented by:

where: a = 5-50, b «1 or 2, c = 1 or 2, R1 = (C1-C4) alkyl, = H or (C1 ~ C4) alkyl, R8 = (C6-C12) cycloalkyl or (Cg -C ^) aromatics and

5 where R = H or (C 1 -CA) alkyl or

where R8 = (alkyl, (C8 -C18) cycloalkyl or (C8 -C18) aronate. 7 where formula (II) is represented by

where: d = 5-50, R7 = (C1-C4) alkyl, R8 = H or (C ^ C.) alkyl, o J-R = (C2-C ^ 2 ^ alkyl, (C8-C ^ 2)) cycloalkyl or (C8 -C18) aromatic and

wherein R11 = H or (C1 -C4) alkyl; and wherein formula (III) is represented by

where: e = 5-50 R12 = (Cx-C 4) alkyl, R13 = H or (C 1 -C 12) alkyl, R 14 = (C 2 -C 12) alkyl or (C 8 -C 12 cyloalkyl or ^ C 6 -C 12 aroate) and

wherein R = (C8 -C18 g) aromatics, (C8 -C18 g) cycloalkyl or (C8 -C18 g) alkyl and wherein aromatics, cycloalkyl or alkyl are based on diglycidyl compounds.

The invention provides an emulsifier system that results in polyurethane dispersion based coatings with improved water resistance. Namely, the emulsifier system according to the invention results in a decrease in the number of undesired side reactions.

Other advantages of the emulsifier system according to the invention are obtaining a better film formation of the coating, obtaining a dispersion with smaller particles and the occurrence of less foaming during the dispersion.

According to a preferred embodiment of the invention, a compound of formula (I) is used as the emulsifier system.

The preparation of the emulsifier system of formula (I) can be carried out in a first step for preferably 1-3 hours, a reaction between an alkoxy polyalkylene glycol and an acid anhydride at temperatures between 100 ° C and 200 ° C, preferably between 110 ° C and 130 ° C. In a second step, the product obtained in the first step then reacts with alkylene oxide. The reaction temperature in this second step can be between 100 ° C and 200 ° C, preferably between 120 ° C and 130 ° C.

Both reactions can be carried out with or without a catalyst. Suitable catalysts are, for example, tertiary amines, dimethylbenzylamine, tetramethylammonium bromide and triethylamine. The catalysts can be used in amounts of, for example, 0.025 to 0.5% by weight.

The reactions can take place both solvent-free and in the presence of solvents such as, for example, toluene, xylene or N-methylpyrolidone. The reactions are preferably carried out solvent-free.

Suitable alkoxy polyalkylene glycols are methoxy polyethylene glycol, butoxy polyethylene glycol and alkoxy copolymers of ethylene glycol and propylene glycol. Preferably, methoxy polyethylene glycol (MPEG), with a molecular weight between preferably 500 and 1000, is used.

Suitable acid anhydrides are trimellitic anhydride and pyromelitic anhydride. Trimellitic acid hydride (TMA) is preferably used.

Suitable alkylene oxides are, for example, ethylene oxide, propylene oxide, butylene oxide and glycidyl versatate (Cardura E from Shell). Propylene oxide (PPO) is preferably used.

The alkoxy polyalkylene glycol: acid anhydride molar ratio is usually between 1: 0.9 and 1: 1.1 and is preferably between 1: 1.0 and 1: 1.05. The molar ratio (reaction product of alkoxy polyalkylene glycol and acid anhydride): alkylene oxide is usually between 1: 1.9 and 1: 2.2 and preferably between 1: 2.0 and 1: 2.1.

According to a preferred embodiment of the invention, in formula (I): a = 15-20, b = 1, c = 2, R = methyl, R2 = H, 3 R = C1-aromatic and

t where R5 = CHj

The preparation of the emulsifier system according to formula (II) can be carried out in a first step by reaction between an alkoxy polyalkylene glycol and an anhydride at temperatures between 100 ° C and 200 ° C, preferably between 110 ° C and 130 ° C, for 1- 3 hours to run. The reaction product obtained then reacts in a second step, for 1-3 hours, at temperatures between 100 ° C and 200 ° C, preferably at temperatures between 130 ° C and 140 ° C, with an epoxy alcohol.

The alkoxy polyalkylene glycol preferably used is methoxy polyethylene glycol (MPEG) with a molecular weight between preferably 500 and 1000. Other suitable alkoxy polyalkylene glycols are, for example, butoxy polyalkylene glycol and alkoxy copolymers of ethylene glycol and propylene glycol.

Suitable anhydrides are, for example, hexahydrophthalic anhydride, phthalic anhydride and succinic anhydride. Succinic anhydride is preferably used.

Glycidol is preferably used as epoxy alcohol.

The alkoxy polyalkylene glycol: anhydride molar ratio is usually between 1: 0.9 and 1: 1.1 and is preferably between 1: 1.0 and 1: 1.05. The molar ratio (reaction product of alkoxy polyalkylene glycol and anhydride): epoxy alcohol is usually between 1: 0.9 and 1: 1.15 and is preferably between 1: 1.0 and 1: 1.1.

Both reactions can be carried out with or without a catalyst. Suitable catalysts are, for example, tertiary amines, dimethylbenzylamine, tetramethylammonium bromide and triethylamine. The catalysts can be used in amounts of, for example, 0.025 to 0.5% by weight.

The reactions can take place both solvent-free and in the presence of solvents such as toluene, xylene or N-methylpyrolidone. The reactions are preferably carried out solvent-free.

According to a preferred embodiment of the invention, in formula (II): d = 15-20.7 R = methyl, R8 = H, R ^ = C, -alkyl and

where 11

R = H

The preparation of the emulsifier system of formula (III) can be carried out by reaction in a first step between an alkoxy polyalkylene glycol and an anhydride at temperatures between 100 ° C and 200 ° C, preferably between 110 ° C and 130 ° C, for 1-3 hours. The intermediate obtained in the first step can then react in a second step with a diglycidyl ether for 1-3 hours at temperatures between 100 ° C and 200 ° C, preferably between 130 ° C and 140 ° C.

Suitable alkoxy polyalkylene glycols are, for example, methoxy polyethylene glycol, butoxy polyethylene glycol and alkoxy copolymers of ethylene glycol and propylene glycol. MPEG, with a molecular weight between 500 and 1000, is preferably chosen.

Suitable anhydrides are succinic anhydride, phthalic anhydride and hexahydrophthalic anhydride. Preferably succinic anhydride is chosen.

Suitable diglycidyl ethers are, for example, the diglycidyl ether of bisphenol A, diglycidyl ether of butanediol, diglycidyl ether of neopentyl glycol and the diglycidyl ether of cyclohexanedimethanol. Preferably the diglycidyl ether of bisphenol A is used.

The alkoxy polyalkylene glycol: anhydride molar ratio is usually between 1: 0.9 and 1: 1.1 and is preferably between 1: 1.0 and 1: 1.05. The molar ratio (reaction product of alkoxy polyalkylene glycol and anhydride): diglycidyl ether is usually between 1: 0.45 and 1: 0.6 and preferably between 1: 0.50 and 1: 0.55.

The reactions can be carried out both solvent-free and in the presence of solvents such as toluene, xylene and N-methylpyrolidone. The reactions are preferably carried out solvent-free.

Both reactions can be carried out with or without a catalyst. Suitable catalysts are, for example, tertiary amines, dimethylbenzylamine, tetramethylammonium bromide and triethylamine. The catalysts can be used in amounts of, for example, 0.025 to 0.5% by weight.

According to a preferred embodiment of the invention, in formula (III): e = 15-20, R ^ = methyl E13 = H, R14 = CO2 alkyl and

where R16 = - (C6H4) -C3H6- (C6H4) -

The preparation of non-ionic polyurethane dispersions can be done by known methods such as those described for example on pages 121-138 of the aforementioned article "Advances in Urethane Science and Technology". The preparation of polyurethane dispersions can take place in a number of steps, namely first the preparation of a precursor, then a dispersion process and then chain extension. In the preparation of a precursor, it is preferable to obtain short chains with terminal isocyanate (NCO) groups, so that this prepolymer can react further later. NCO-terminal groups can be obtained by reacting a polymeric diol with a diisocyanate, for example in the ratio of diol: diisocyanate 1: 2.

Various polymers (molecular weight between about 500 to 4000) can be used as diol, provided that they are provided with terminal OH groups. Examples of these are polypropylene glycol, linear polyesters, polycaprolacones, polycarbonates or polytetrahydrofurans. In addition to these polymeric diols, shorter diols or triols can also be used. For this purpose, for example, 1,4-butane diol, 1,6-hexanediol and trimethylol propane can be used.

As the diisocyanate, for example, isophorone diisocyanate, toluene diisocyanate, 1,6 hexane diisocyanate or methane diphenyl diisocyanate can be used. The resulting NCO-terminated precursor can then be dispersed in water. The chain extension can be done with water or with a primary or secondary amine such as, for example, ethylenediamine.

The emulsifier systems according to the invention are used in amounts of between 5 and 50 wt.% During the preparation of the precursor. %, more particularly between 20 and 35% by weight.

The emulsifier system according to the invention is applicable in the preparation of, for example, non-ionic polyurethane dispersions, UV-curable polyurethane dispersions, hybrid systems such as polyurethane-acrylate hybrid systems and non-ionic-anionically combined polyurethane dispersions.

Said dispersions and systems can serve as a basis for glues and paints.

The invention is illustrated by the following non-limiting examples.

Examples

Example I

Preparation of emulsifier system according to formula (I) 685 wt. parts of methoxy polyethylene glycol (MPEG) and 184 wt. parts of trimellitic anhydride (TMA) were heated to 120 ° C in a vessel with stirrer, under nitrogen. After 3 hours 120 ° C (at an acid number of 130), it was warmed to 125 ° C and over a 3 hour period, 129 wt. parts of propylene oxide into the vessel. 2 hours after dosing, at 125 ° C, an acid number <5 was reached.

The reaction product had the following constants: Hydroxyl number: 110 mg KOH / gram

Acid value: <5 mg KOH / gram

Ethylene glycol content per mole: 66%

Example II

Preparation of emulsifier system according to formula (II) 749 wt. parts of methoxy polyethylene glycol (MPEG) and 163 wt. parts of phthalic anhydride (PZA) were heated to 120 ° C in a vessel with stirrer, under nitrogen.

After 3 hours at 120 ° C (at an acid number of 75), 88 wt. parts of glycidol added. After 2 hours at 135 ° C, an acid number <5 was reached.

The reaction product had the following constants: Hydroxyl number: 135 mg KOH / gram

Acid value: <5 mg KOH / gram

Ethylene glycol content per mole: 72%

Example m

Preparation of emulsifier system according to formula (III) 662 wt. parts of methoxy polyethylene glycol (MPEG) and 146 parts by weight of phthalic anhydride (PZA) were heated to 120 ° C in a vessel with stirrer, under nitrogen. After 3 hours at 120 ° C (at an acid number of 75), 191 wt. parts of diglycidyl ether of bisphenol (Epikote 828) added. After 2 hours at 135 ° C, an acid number <5 was reached.

The reaction product had the following constants: Hydroxyl number: 61 mg KOH / gram

Acid value: <5 mg KOH / gram

Ethylene glycol content per mole: 68%

Comparative Experiment A Emulsifier System based on MPEG and IPDI

678 wt. parts of methoxy polyethylene glycol (MPEG) and 209 wt. parts of isohorone diisocyanate (IPDI) were heated to 90 ° C in a vessel with stirrer, under nitrogen. After 3 hours 90 ° C (at an NCO content of 4.5%), it was cooled to 35 ° C and then 113 wt. parts of aminoethyl propanediol (AEPD) added. Stirring was then made until the NCO content was 0%.

The reaction product obtained had the following constants:

Hydroxyl number: 105 mg KOH / gram

Acid number: 0

Ethylene glycol content per mole: 65%

Example IV

Preparation polyurethane dispersion 133 wt. parts of emulsifier system according to Example I, 79 wt. parts of polypropylene glycol, 40 wt. parts of ethylene glycol diether (Dianol 22) and 146 wt. parts of isophorone diisocyanate were mixed and the mixture was warmed to 90 ° C. After 3 hours at 90 ° C, the mixture was transferred to a dispersion vessel in which 1.5 wt.% At an NCO content of 6.8% in 1.5 hours. parts of demineralised water had been submitted. Then the vessel was warmed to 45 ° -50 ° C, chain extension occurred. At an NCO content of 0%, the dispersion was cooled to <35 ° C and drained.

Example V

Preparation polyurethane dispersion 172 wt. parts of emulsifier system according to example I, 24 wt. parts of hexanediol-1.6 and 167 wt. parts of isophorone diisocyanate were mixed and the mixture was warmed to 90 ° C. After 3 hours at 90 ° C, the mixture with an NCO content of 8.6%, 86 wt. parts of hydroxyethyl acrylate were added dropwise. After 5 hours of reaction at 90 ° C, the NCO content was <0.1%. The product was then pumped in 1.5 hours to a dispersion vessel containing 550 wt. parts of demineralised water had been submitted.

Comparative Experiment B

350 wt. parts of emulsifier system according to Comparative Experiment A, 237 wt. parts of polypropylene glycol, 71 wt. parts of ethylene glycol diether (Dianol 22) and 342 wt. parts of isophorone diisocyanate were mixed and warmed to 90 ° C. After 90 ° C for 3 hours, the mixture was pumped to a dispersion vessel containing 1222 wt.% At an NCO content of 6.4% in 1.5 hours. parts of demineralised water had been submitted. Then the vessel was warmed to 40 ° -45 ° C causing chain extension. Anti-foaming agent was added depending on the amount of foam. At an NCO content of 0%, the dispersion was cooled to 30 ° C and drained.

The differences between the emulsifier systems of the Examples and Comparative Experiments and the dispersions of the Examples and Comparative Experiments could be summarized as follows (see Table I).

Table I

Ex. I Exp. a

Purity of the 95% 75% 1) emulsifier system '

Ex. IV Exp. B

Preparation of the dispersion low foam high foam Particle size 50 nm. 100 nm.

Film properties of the ex. IV Exp. B

dispersion according to: ------ ------ 2)

Water resistance 'good moderate

Film formation 'fine moderate 1) determined using GPC (gel permeation chromatography calibrated to polystyrene standard) 2) determined using DIN 50017 3) visually determined

From this it could be concluded that the emulsifier system according to the invention resulted in a decrease in the number of undesired side reactions and consequently in an increased purity. Better dispersibility was obtained due to a reduction in foaming and a decrease in particle size. The dispersions showed improved waterfastness and film formation properties.

Claims (14)

Build-in emulsifier system based on alkylene oxide units, characterized in that the emulsifier system is an emulsifier system according to formula (I), formula (II) or formula (III) wherein formula (I) is represented by:

where: a = 5-50, b = 1 or 2, c = 1 or 2, R1 = (C1-C4) alkyl, R2 = H or () alkyl, R8 = (Cg-C12) cycloalkyl or (Cg-C ^ Jaromat and

where R 1 = H or (C 1 -C 4) alkyl or

where R8 = (C 1 -C 6) alkyl, (C 6 -C 32) cycloalkyl, or C 6 -C 32-aromatics? where formula (II) is represented by

where: d = 5-50, R7 = (C1-C4) alkyl, R8 = H or (Cx-C4) alkyl, R ^ = (C2-C12) alky1, (cg ~ c12 ^ cycloalkyl or (C8-) Cn2) aromatics and

11 11 wherein R = H or (C 1 -C 12) alkyl; and wherein formula (III) is represented by

where: e = 100-500 R12 - (C1-4) alkyl, R13 = H or (^ - € 4) alkyl, R14 = (C2-C12) alkyl or (C6-C12) cycloalkyl or ^ C6_C12 ^ aromatic and

wherein 16 R 1 (C 8 -C 20 g) aromatic, (C 8 -C 20 g) cycloalkyl or (C 6 -C 75) alkyl and wherein aromatic, cycloalkyl and alkyl are based on diglycidyl compounds. Emulsifier system according to claim 1, characterized in that in formula (I): a = 15-20 b = 1 c = 2 1 R = methyl, R2 = H, 3 R = C1-aromatic and

t where E5 = CH3 Emulsifier system according to claim 1, characterized in that in formula (II): d = 15-20 7 R = methyl, R8 = H, g R = C9 alkyls

where 11 R = H Emulsifier system according to claim 1 / characterized in that in formula (III): e = 15-20 R "* 3 = methyl R13 = H, R14 = C, -alkyl and

where R16 = - (C6H4) -C3H6- (C6H4) - Process for the preparation of an emulsifier system according to formula (I), characterized in that in a first step a reaction is carried out between an alkoxy polyalkylene glycol and an acid anhydride at a temperature between 100 ° C and 200 ° C for 1-3 hours. after which in a second step the product obtained in the first step reacts with alkylene oxide at a reaction temperature between 100 ° C and 200 ° C, the molar ratio of alkoxy polyalkylene glycol: acid anhydride being between 1: 0.9 and 1: 1.1 and the molar ratio (reaction product of alkoxy polyalkylene glycol and acid anhydride): alkylene oxide is between 1: 1.9 and 1: 2.2. Process according to Claim 5, characterized in that the alkoxypolyalkylene glycol used is methoxy polyethylene glycol, the acid anhydride trimellitic anhydride and the alkylene oxide propylene oxide. Process for the preparation of an emulsifier system according to formula (II), characterized in that in a first step a reaction is carried out between an alkoxy polyalkylene glycol and an anhydride for a period of 1-3 hours at a temperature between 100 ° C and 200 ° C. the reaction product obtained is then reacted in a second step, at a temperature, between 100 ° C and 200 ° C, with an epoxy alcohol, the molar ratio of alkoxy polyalkylene glycol: anydride being between 1: 0.9 and 1: 1.1 and the molar ratio (reaction product of alkoxy polyalkylene glycol and anhydride): epoxy alcohol is between 1: 0.9 and 1: 1.15. Process according to claim 7, characterized in that the alkoxy polyalkylene glycol used is methoxy polyethylene glycol, the anhydride succinic anhydride and the epoxy alcohol glycidol. Process for the preparation of an emulsifier system according to formula (III), characterized in that in a first step a reaction is carried out between an alkoxy polyalkylene glycol and an anhydride for 1-3 hours at a temperature between 100 ° C and 200 ° C, is then carried out, after which the intermediate obtained in the first step is reacted in a second step with a diglycidyl ether for 1-3 hours at a temperature between 100 ° C and 200 ° C, the molar ratio of alkoxy polyalkylene glycol: anhydride being between 1: 0.9 and 1: 1.1 and the molar ratio (reaction product of alkoxy polyalkylene glycol and anhydride): diglycidyl ether is between 1: 0.45 and 1: 0.6. Process according to Claim 9, characterized in that the alkoxy polyethylene glycol contains methoxy polyethylene glycol, the anydride succinic anhydride and the diglycidyl ether of bisphenol A as the diglycidyl ether. An polyurethane dispersion based on an emulsifier system according to any one of claims 1-4 or a polyurethane dispersion based on an emulsifier system obtained according to any one of claims 5-10. Process for the preparation of polyurethane dispersions, characterized in that the emulsifier used is the emulsifier system according to any one of claims 1 to 4 or the emulsifier system obtained according to any one of claims 5-10, in amounts between 5% by weight and 50% by weight . Use of a polyurethane dispersion according to claim 11 or use of a polyurethane dispersion obtained according to claim 12. 14. Emulsifier system, polyurethane dispersion, methods and use as substantially described and / or illustrated in more detail in the examples.