Composition containing low-VOC, aminoalkyl-functional silicon compounds for coating colors for the treatment of paper or film

Abstract

A method of coating a paper surface proceeds by applying a composition which is low in volatile organic compounds (VOC) or essentially free of VOC, wherein the composition is art least partially based on one or more partially or fully hydrolyzed and optionally condensed or co-condensed aminoalkyl- and oligosilyated-aminoalkyl-, alkoxy- or hydroxy-functional silicon compounds and the alcohol is at least partially removed from the composition

Claims

1-16. (canceled)

17. A method of coating paper or film, comprising: applying to a surface of a paper or a film, a composition low in volatile organic compounds (VOC) or substantially VOC-free, the composition being based at least proportionally on one or more partially or completely hydrolyzed and optionally condensed or cocondensed aminoalkyl-functional and also oligo-silylated-aminoalkyl-, alkoxy- and/or hydroxy-functional silicon compounds, and removing an alcohol at least proportionally from the composition.

18. The method according to claim 17, wherein at least one silicon compound of the aminoalkyl-functional and/or oligo-silylated-aminoalkyl-, -alkoxy- and/or hydroxy-functional silicon compounds present in the composition represent a reaction product from the reaction of (A) at least one aminoalkylalkoxysilane of the general formula I
NR′.sub.2[(CH.sub.2).sub.2NR′].sub.x—Y—Si(R″).sub.n(OR).sub.3-n   (I), in which groups R, R′ and R″ are alike or different and are each a hydrogen atom or a linear or branched alkyl group having 1 to 8 C atoms, Y is a divalent alkylene group selected from the group consisting of —(CH.sub.2).sub.2—, —(CH.sub.2).sub.2—, —(CH.sub.2).sub.3— and —[CH.sub.2CH(CH.sub.3)CH.sub.2]—, x is 0, 1 or 2, and n is 0 or 1, or (B) at least one bis-silylated alkylamine of the general formula II
(RO).sub.3-m(R″).sub.mSi—Y—[NR′(CH.sub.2).sub.2].sub.yNR′[(CH.sub.2).sub.2NR′].sub.z—Y—Si(R″).sub.n(OR).sub.3-n   (II), in which groups R, R′ and R″ are alike or different and are each a hydrogen atom or a linear or branched alkyl group having 1 to 8 C atoms, groups Y are alike or different and Y is a divalent alkylene group selected from the group consisting of —CH.sub.2—, —(CH.sub.2).sub.z—, —(CH.sub.2).sub.3— and —[CH.sub.2CH(CH.sub.3)CH.sub.2]—, y and z independently are 0, 1 or 2, and m and n independently are 0 or 1, or (C) at least one tris-silylated alkylamine of the general formula III
N[—Y—Si(R″).sub.n(OR).sub.3-n].sub.3   (III), in which groups R and R″ are alike or different and are each a hydrogen atom or a linear or branched alkyl group having 1 to 8 C atoms, Y independently is a divalent alkylene group selected from the group consisting of —CH.sub.2, —(CH.sub.2).sub.2, —(CH.sub.2).sub.3— or —[CH.sub.2CH(CH.sub.3)CH.sub.2]—, and n independently is 0 or 1, or (D) at least two of the alkylamines of formula I, II and III, wherein a free alcohol content of the composition is less than or equal to 1% by weight, based on the composition, and wherein the reacted units are formed by partial or complete hydrolysis and also condensation or cocondensation of compounds (A), (B), (C) or (D).

19. The method according to claim 17, wherein component (A) is at least one selected from the group consisting of AMMO, AMEO, DAMO, TRIAMO and 3-(N-alkylamino)propyltrialkoxysilane, wherein alkyl is methyl, ethyl, n-propyl or n-butyl and alkoxy is methoxy or ethoxy, component (B) is at least one selected from the group consisting of bis-AMMO, bis-AMEO, bis-DAMO and bis-TRIAMO, and component (C) is at least one selected from the group consisting of tris-AMMO and tris-AMEO.

20. The method according to claim 17, wherein the composition comprises from 0.1% to 99.5% by weight, based on the composition, of at least one at least partially hydrolyzed silicon compound.

21. The method according to claim 17, wherein the composition has a water content of 99.9% to 0.5% by weight, based on the composition.

22. The method according to claim 17, therein the composition has a pH of 2 to 11.

23. The method according to claim 17, wherein the composition comprises acid and/or a corresponding salt of acid and one of the present amino-functional compounds.

24. The method according to claim 17, wherein the composition comprises at least one metal oxide, which has an average particle size of less than 1 μm, in an amount of 5% to 50% by weight, based on the composition.

25. The method according to claim 17, wherein the composition comprises at least partially hydrolyzed, aminofunctional silicon compounds in an amount of 1% to 10% by weight, calculated as silicon and based on the composition.

26. The method according to claim 17, wherein the composition is based on the composition comprising silicon compounds and on at least one metal oxide and additionally comprises at least one further component selected from the group consisting of series binder, crosslinker, optical brightener, and process assistant

27. The method according to claim 17, wherein the composition is applied to the surface of a film or of a PE-modified paper and is dried and/or cured.

28. The method according to claim 17, wherein a coated paper or film is suitable for inkjet applications and/or as photographic paper or as film for photographic prints.

Description

EXAMPLES

[0064]

TABLE-US-00001 Technical data Determination method according to Density DIN 51 757 Viscosity DIN 53 015 Color number ISO 4630 pH DIN 19 268 (20° C., 1000 g/l) Flash point EN 22 719

[0065] The determination methods used to evaluate the present examples were in particular as follows:

Determination of Free Alcohol Content:

[0066] The alcohol determination was carried out by means of GC.

[0067] Column: RTX 200 (60 m)

[0068] Temperature program: 80-10-25-240-0

[0069] Detector: FID

[0070] Injection volume: 1.0 μl

[0071] Internal standard: 2-Butanol

Dry Residue:

[0072] The solids content of the aqueous silane systems is determined as follows:

[0073] 1 g of the sample is weighed out into a small porcelain dish and dried to constant weight in a drying cabinet at 105° C.

SiO.SUB.2 .Content:

[0074] 1.0 to 5.0 g of the sample in a 400 ml glass beaker is admixed with a Kjeldahl tablet and 20 ml of sulfuric acid, and the mixture is first slowly heated. The glass beaker is covered with a watch glass. The temperature is raised until the sulfuric acid fumes significantly and all of the organic constituents have been destroyed, the solution remaining clear and bright. The cold digestion solution is diluted to about 200 ml with distilled water and briefly boiled (water at the edge of the glass beaker allowed to flow under the acid). The residue is filtered through a white-ribbon filter and washed with hot water until the washing water indicates a pH of >4 (pH paper). The filter is dried in a platinum crucible, incinerated and calcined in a muffle furnace at 800° C. for 1 hour. After weighing, the residue is fumed off with hydrofluoric acid, the crucible is calcined by means of a fan burner, and calcined again if necessary at 800° C., and, after it has cooled, is weighed. The difference between the two weighings corresponds to the SiO.sub.2 content.

[0075] Evaluation: D×100/E=% by weight SiO.sub.2

[0076] D=Weight difference before and after hydrofluoric acid removal of silicon as volatile silicon tetrafluoride, in mg

[0077] 100=Conversion to %

[0078] E=Initial mass in mg

Methanol After Hydrolysis:

[0079] About 5 g of sample are weighed accurately into a 500 ml conical flask with ground-glass joints, and are hydrolyzed with 25 ml of sulfuric acid (w=20%) with shaking until a clear solution has formed.

[0080] Following addition of 75 ml of water, the sample is neutralized with aqueous sodium hydroxide solution (w=20%) and subjected to steam distillation in a suitable apparatus. The distillate is collected in a 250 ml measuring flask. Following addition of 2-butanol as internal standard, the sample is made up to the mark with distilled water.

[0081] The alcohol determination is made by means of GC.

[0082] Column: RTX 200 (60 m)

[0083] Temperature program: 90-10-25-240-0

[0084] Detector: FED

[0085] Injection volume: 1.0 μl

[0086] Internal standard: 2-Butanol

Example 1

Composition With Reduced VOC Content

[0087] A stirred apparatus with metering means and reflux condenser was charged under a nitrogen atmosphere with 470.6 g of Dynasylan® 1189 [N-(n-butyl)-3-aminopropyltrimethoxysilane, manufacturer: Degussa GmbH] and 80.0 g of methanol. Subsequently, via a metering means, a mixture consisting of 28.8 g of H.sub.2O and 28.8 g of methanol was metered in over the course of 10 minutes (molar hydrolysis ratio Si:H.sub.2O=1:0.8). During this addition the temperature rose from 28° C. to 50° C. The mixture was stirred at 60° C. for 3 h. Thereafter 208.89 g of methanol were distilled off at about 200 mbar. The final weight of the residue/product was 394.87 g.

[0088] A clear, slightly yellowish liquid was obtained which is stable on storage.

TABLE-US-00002 SiO.sub.2 content: 29.6% (mass) Methanol (after hydrolysis): 19.5% (mass) Viscosity (20° C.): 26 mPa s Density (20° C.): 0.996 g/cm.sup.3

Example 2

Composition With Reduced VOC Content

[0089] A stirred apparatus with metering means and reflux condenser was charged under a nitrogen atmosphere with 470.6 g of Dynasylan® 1189 and 80.0 g of methanol. Subsequently, via the metering means, a mixture consisting of 43.20 g of H.sub.2O and 43.20 g of methanol was metered in over the course of 10 minutes (molar hydrolysis ratio Si:H.sub.2O=1:1.2). During this addition the temperature rose from 28° C. to 56° C. The mixture was stirred at 60° C. for 3 h. Thereafter 263.50 g of methanol were distilled off at about 200 mbar, The final weight of the residue/product was 357.77 g.

[0090] A clear, viscose, slightly yellowish liquid was obtained which is stable on storage.

TABLE-US-00003 SiO.sub.2 content: 32.0% (mass) Methanol (after hydrolysis): 9.2% (mass) Viscosity (20° C.): 187 mPa s Density (20° C.): 1.027 g/cm.sup.3

Example 3

A Substantially VOC-Free Composition

[0091] A stirred apparatus with metering means and reflux condenser was charged under a nitrogen atmosphere with 498.2 g of water and 55.0 g of formic acid (conc. HCOOH=85%). Subsequently, using the metering means, 235.7 g of Dynasylan® 1189 were metered in. The pH was 4.8. The mixture was stirred at 60° C. for 3 h. Thereafter, at about 130-200 mbar, a methanol/water mixture was distilled off. The final weight of the residue was 589.0 g.

[0092] A clear, slightly yellowish liquid was obtained which has a pH of 5.3 and is stable on storage.

TABLE-US-00004 SiO.sub.2 content: 9.2% (mass) Flash point: >100° C. Free methanol: 0.5% (mass) Viscosity (20° C.): 11 mPa s Density (20° C.): 1.070 g/cm.sup.3 Dry residue 105° C.: 36.2% (mass)

Comparative Example 1

[0093] Dispersion with Dynasylan® 1189 Incl. Methanol

[0094] N-Butylaminopropyltrimethoxysilane, (C.sub.7H.sub.16N)Si(OCH.sub.3).sub.3, 235 g/mol, methanol releasable by hydrolysis: 48.5%

[0095] Apparatus:

[0096] Rotor-stator systems (Ultra-Turrax)

[0097] Jacketed pot, 3 liters

[0098] Dissolver for stirred incorporation of AEROSIL®200

[0099] Polytron (rotor-stator) dispersing apparatus

[0100] Stirrer, 2 dropping funnels for dropwise addition of the silane solution and of the HCl solution

[0101] Heatable ultrasound bath (40 W ultrasound power)

[0102] 500 μm sieve

[0103] 1600 g of DI water were introduced, and 400 g of AEROSIL® 200 were incorporated by stirring with the dissolver; acidification to a pH of 2.1 was carried out with 5 g of 18% strength HCl, and the batch was dispersed at 10 000 rpm for 15 min, using the Polytron. The solids content was found to be 20.07%.

[0104] Dissolver again at 2000 rpm, dropwise addition therein of 98.6 g of Dynasylan® 1189 in the form of a 20% strength solution in methanol, simultaneously with the maintenance of the pH of between pH 3-4 by dropwise addition of 18% strength HCl (total of 13 g, dispersion gels at pH >4). A further 15-min reaction time at 2000 rpm, followed by 60 min in the ultrasound bath at 80° C. (with lid), cooling and filtration via a 500 μm sieve.

[0105] Methanol content of the dispersion: 88.4 g=4.2%

[0106] The viscosity of the dispersions thus prepared was measured with a Brookfield viscometer after 24 h.

Example 4

[0107] Dispersion With the Composition from Example 3

[0108] Procedure analogous to that of comparative example 1, with the difference that 41.3 g of the composition from example 3 were used as a 40% strength solution in water, pH 4.1, VPS Hydrosil 2930, as silane component. Additionally 8 g of HCl were used.

[0109] Methanol content of the dispersion: no methanol detected

Comparative Example 2

[0110] Dispersion with Dynasylan® Hydrosil 2627 (Substantially Free from Alcohol, cf. EP 0 716 127 A2)

[0111] Analogous to comparative example 1, with the difference that 94 g of Dynasylan® Hydrosil 2627 (diluted to 20% strength solution in water) are used as silane component. 13 g of HCl are required.

Example 5

[0112] Dispersion with “1189 Oligomer” from Example 1

[0113] Partially hydrolyzed VPS “1189 oligomeric”, (C.sub.7H.sub.36N)SiO.sub.0.8(OCH.sub.3).sub.1.4, 203.4 g/mol, methanol releasable by hydrolysis 26.1%

[0114] Analogous to comparative example 1, with the difference that 85.3 g of oligomer (20% strength solution in water, pH 4.0) were used as silane component. 7 g of HCl were used.

[0115] Methanol content of the dispersion: 4.45 g=0.2%

Example 6

[0116] Dispersion with “1189 Oligomer” from Example 2

[0117] Partially hydrolyzed VPS “1189 oligomeric”, (C.sub.7H.sub.16N)SiO.sub.1.2(OCH.sub.3).sub.0.4, 183.4 g/mol, methanol releasable by hydrolysis 8.3%

[0118] Analogous to comparative example 1, with the difference that 77.0 g of oligomer (20% strength solution in water, pH 4.2) were used as silane component. 7.5 g of HCl were used.

[0119] Methanol content of the dispersion: 1.28 g=0.06%

TABLE-US-00005 TABLE 1 Data of the modified silica dispersions from comparative examples 1 and 2 and also examples 1 to 3; cf. examples 4 to 6 Dispersion 1 with Dispersion 3 with composition from Dispersion 2 with composition from Dispersion 4 with Dispersion 5 with comparative composition from comparative composition from composition from example 1: example 3: example 2: example 1: example 2: 4.25% MeOH VOC-free VOC-free 0.2% MeOH 0.06% MeOH pH 2.4 3.3 2.1 3.0 3.0 Solids content w 0.21 0.23 0.20 0.22 0.23 20 rpm; Sp.2 104 mPa s 132 mPa s 84 mPa s 160 mPa s 184 mPa s 50 rpm: Sp.2  88 mPa s 116 mPa s 88 mPa s 164 mPa s 188 mPa s 100 rpm: Sp.2 120 mPa s 124 mPa s 96 mPa s 160 mPa s 172 mPa s rpm = Revolutions per minute of the Brookfield viscometer

Application example

Preparation of an Inkjet Coating Color:

[0120] Inkjet coating colors were produced from the aqueous dispersions; cf. table 1.

[0121] The dispersions from the examples and comparative example were mixed on a dissolver at 500 rpm with a 13% strength solution of polyvinyl alcohol (solid, abbreviation PVA) Mowiol 40-88 from Clariant over the course of 10 minutes. The ratio on combining was calculated so as to give a dispersion C with a strength of 18 percent—based on the solid (pyrogenic oxide+PVA), in a ratio of 4:1 (100:25 Aerosil® to PVA, and addition of water if appropriate). The viscosity of this dispersion C, the inkjet coating color, was measured by means of a Brookfield viscometer after 24 h.

TABLE-US-00006 TABLE 2 Viscosity of the coating colors measured after 24 h: Coating Coating Coating Coating Coating color 1 color 2 color 3 color 4 color 5 from from from from from dis- dis- dis- dis- dis- persion 1 persion 2 persion 3 persion 4 persion 5 (“4.25% (“VOC- (“VOC- (“0.2% (“0.06% MeOH”) free”) free”) MeOH”) MeOH”) Solids content 17.45 18.64 Not 18.21 17.93 of the possible coating color to (pyrogenic produce! oxide with silane + PVA) % by weight Viscosity 480 360 n. a. 430 330 [mPa s] at 100 rpm and 50° C.

[0122] These coating colors were applied by means of a profiled bar coater to a photographic base paper (thickness 300 micrometers). The wet film thickness of the coating color was 110 micrometers. The coating was dried at 105° C. for 8 minutes.

[0123] The papers with the applied coating were printed on an Epson Stylus Photo R240 at maximum resolution.

TABLE-US-00007 TABLE 3 Evaluation of the print outcome: Coating 1 from Coating 2 from Coating 3 from Coating 4 from Property coating color 1 coating color 2 coating color 4 coating color 5 evaluated Evaluation Rating Evaluation Rating Evaluation Ratin Evaluation Note Color intensity Good 2 Good 2 Good 2 Good 2 Resolution Good 2 Good 2 Good 2 Good 2 Ink run No 1 No 1 No 1 No 1 (bleeding) bleeding bleeding bleeding bleeding Color shift Good 2 Good 1.5 Good- 1.5 Good- 1.75 very good very good Average Good 1.75 Good 1.625 Good 1.625 Good 1.688 Best rating 1, poorest rating 6

[0124] In the total of all of the properties of the coatings, all the coatings exhibited approximately the exact same values.

[0125] The viscosities of the coating colors produced with the various dispersions were substantially comparable, Here there was no apparent disadvantage from the reduction in methanol,

[0126] With the composition and dispersion/coating color of the invention it is therefore possible to provide a coating which, despite a significant reduction in the VOC fraction, produces an equally good print with an inkjet printer.