A VOC-free, aqueous and storage-stable N-vinylbenzylaminoalkyl-functional siloxanol and process for the production thereof

Abstract

An aqueous, storage-stable and preferably colorless composition containing N-vinylbenzylaminoalkyl-functional siloxanols is derived from a reaction of hydrolysis products and optionally, condensation products of hydrolysis products, of at least one aminoalkyl-functional alkoxysilane or a mixture of aminoalkyl-functional alkoxysilanes with vinylbenzyl halide. The composition contains not less than 1% by weight of N-vinylbenzylaminoalkyl-functional siloxanols and/or salts of the protonated N-vinylbenzylaminoalkyl-functional siloxanols and water, based on the weight of the composition. The composition has a pH of 2 to 3.5. A process can be used for producing this composition.

Claims

1: An aqueous composition comprising N-vinylbenzylaminoalkyl-functional siloxanols and, optionally, salts of the protonated N-vinylbenzylaminoalkyl-functional siloxanols which are derived from a reaction of hydrolysis products and, optionally, condensation products of hydrolysis products, of at least one aminoalkyl-functional alkoxysilane or a mixture of aminoalkyl-functional alkoxysilanes with vinylbenzyl halide, wherein the composition comprises 1% to 70% by weight of the N-vinylbenzylaminoalkyl-functional siloxanols and/or the salts of the protonated N-vinylbenzylaminoalkyl-functional siloxanols, and 30% to 99% by weight of water, based on a total weight of the composition; and wherein the composition has an acidic pH.

2: The composition according to claim 1, wherein the composition has a pH of less than 7.0, and/or contains not less than 0.1% by weight of acid selected from the group consisting of inorganic acid, organic acid, and a mixture thereof.

3: The composition according to claim 2, wherein the acid is selected from the group consisting of hydrochloric acid, formic acid, acetic acid, oxalic acid, and fumaric acid.

4: The composition according to claim 1, wherein a weight average molecular weight (Mw) of the N-vinylbenzylaminoalkyl-functional siloxanols and/or the salts of the protonated N-vinylbenzylaminoalkyl-functional siloxanols is not less than 1,000 g/mol, and/or wherein a number average molecular weight (Mn) of the N-vinylbenzylaminoalkyl-functional siloxanols and/or the salts of the protonated N-vinylbenzylaminoalkyl-functional siloxanols is not less than 700 g/mol.

5: The composition according to claim 2, wherein the composition comprises per mol of nitrogen atoms of the siloxanols, 0.2 to 1.5 mol of protons (hydrons) and anions of the halides and, optionally, of the acid.

6: The composition according to claim 1, wherein a content of free alcohol in the composition is not more than 0.5% by weight, and if present, hydrolysable alkoxy groups of less than 5% by weight.

7: The composition according to claim 1, wherein the at least one aminoalkyl-functional alkoxysilane corresponds to formula (I)
(R.sup.1O).sub.3-a-b(R.sup.2).sub.aSi(B).sub.1+b  (I), wherein in formula (I) R.sup.1 independently represents a linear, branched, or cyclic alkyl group having 1 to 8 carbon atoms, R.sup.2 independently represents a linear, branched, or cyclic alkyl group having 1 to 8 carbon atoms, a is independently 0 or 1, and b is independently 0, 1, or 2, and wherein group B in formula (I) independently corresponds to a group of formula (II)
—(CH.sub.2).sub.c—[(NH)(CH.sub.2).sub.d].sub.c[(NH)](CH.sub.2).sub.f].sub.gNH.sub.(2-h)R.sup.3h  (II), wherein in formula (II) R.sup.3 independently represents a linear, branched, or cyclic alkyl, aryl, or alkylaryl group having 1 to 8 carbon atoms; c is independently selected from 1, 2, 3, 4, 5, and 6; d is independently selected from 1, 2, 3, 4, 5, and 6; e is independently selected from 0, 1, 2, 3, 4, 5, and 6; f is independently selected from 1, 2, 3, 4, 5, and 6; g is independently selected from 0, 1, 2, 3, 4, 5, and 6; and h is independently 0 or 1; or wherein group B in formula (I) corresponds to a group of formula (III)
—(CH.sub.2).sub.j—NH.sub.2-p(CH.sub.2—CH.sub.2—NH.sub.2).sub.p  (III) where j=1, 2, or 3; and p=0, 1, or 2.

8: The composition according to claim 7, wherein the at least one aminoalkyl-functional alkoxysilane corresponds to formula (I)
(R.sup.1O).sub.3-a-b(R.sup.2).sub.aSi(B).sub.1+b  (I), and group B in formula (I) corresponds to the group of formula (III)
—(CH.sub.2).sub.3—NH—CH.sub.2—CH.sub.2—NH.sub.2  (III).

9: The composition according to claim 1, wherein a weight average molecular weight (Mw) of the N-vinylbenzylaminoalkyl-functional siloxanols and/or the salts of the protonated N-vinylbenzylaminoalkyl-functional siloxanols is not less than 1,000 g/mol and not more than 100,000 g/mol, and/or wherein a number average molecular weight (Mn) of the N-vinylbenzylaminoalkyl-functional siloxanols and/or the salts of the protonated N-vinylbenzylaminoalkyl-functional siloxanols is not less than 700 g/mol and not more than 100,000 g/mol.

10: The composition according to claim 1, wherein the composition has an alcohol content of <1.0% by weight.

11: A process for producing the composition according to claim 1, comprising: initially charging the at least one aminoalkyl-functional alkoxysilane or the mixture of aminoalkyl-functional alkoxysilanes, which is optionally an alcoholic composition, adding 0.5 to 4.5 mol of water/mol of silicon atoms, optionally, maintaining a temperature in the range from 40 to 65° C. with mixing, obtaining a composition comprising hydrolysis products and, optionally, condensation products of the hydrolysis products, of the at least one aminoalkyl-functional alkoxysilane and hydrolysis alcohol, reacting the hydrolysis products and the condensation products of the hydrolysis products, if present, with vinylbenzyl halide, wherein the vinylbenzyl halide is added in a molar ratio of 1.0:0.60 to 1.0:1.15, based on the aminoalkyl-functional alkoxysilanes or the mixture of aminoalkyl-functional alkoxysilanes, and, optionally, adding the vinylbenzyl halide at a temperature in the range from 40 to 60° C., obtaining a composition of the N-vinylbenzylaminoalkyl-functional siloxanols and, optionally, the salts of the protonated N-vinylbenzylaminoalkyl-functional siloxanols, adjusting the pH of the composition by adding acid selected from the group consisting of inorganic acid, organic acid, and a mixture thereof, adding water, removing alcohol and the hydrolysis alcohol, and obtaining the aqueous composition comprising N-vinylbenzylaminoalkyl-functional siloxanols and, optionally, salts of the protonated N-vinylbenzylaminoalkyl-functional siloxanols, wherein the composition has an acidic pH.

12: The process according to claim 11, wherein the adding water comprises adding a defined amount of water, the removing the alcohol and the hydrolysis alcohol comprises a distillative removal of the alcohol and the hydrolysis alcohol, and wherein the aqueous composition comprising N-vinylbenzylaminoalkyl-functional siloxanols and, optionally, salts of the protonated N-vinylbenzylaminoalkyl-functional siloxanols, comprises 1% to 70% by weight of the N-vinylbenzylaminoalkyl-functional siloxanols and/or the salts of the protonated N-vinylbenzylaminoalkyl-functional siloxanols, and 30% to 99% by weight of water, based on a total weight of the composition.

13: The process according to claim 11, wherein the aqueous composition has a content of free alcohol of not more than 0.5% by weight, and if present, hydrolysable alkoxy groups of less than 5% by weight.

14: The process according to claim 11, wherein the initially charging the at least one aminoalkyl-functional alkoxysilane or the mixture of aminoalkyl-functional alkoxysilanes as an alcoholic composition having a weight ratio of amino-functional alkoxysilane to alcohol of 80:20 to 30:70.

15: The process according to claim 11, wherein during adjustment of the pH of the composition by addition of an acid, a pH of 2.7 to 4 is established.

16: A method, comprising: applying the composition according to claim 1 as an adhesion promoter on inorganic and organic substrates, as an adhesion promoter between inorganic and organic surfaces, for coating inorganic particles for crosslinking with monomers in production of polymers filled with inorganic particles, for reinforcing of organic polymers with inorganic fillers, for coating of inorganic surfaces or organic polymers, and in fibre-reinforced polymers as an adhesion promoter between inorganic fibres and organic polymers.

17: The composition according to claim 9, wherein the weight average molecular weight (Mw) of the N-vinylbenzylaminoalkyl-functional siloxanols and/or the salts of the protonated N-vinylbenzylaminoalkyl-functional siloxanols is not less than 10,000 g/mol and not more than 50,000 g/mol, and/or wherein the number average molecular weight (Mn) of the N-vinylbenzylaminoalkyl-functional siloxanols and/or the salts of the protonated N-vinylbenzylaminoalkyl-functional siloxanols is not less than 1,500 g/mol and not more than 50,000 g/mol.

18: The process according to claim 11, wherein the vinylbenzyl halide is vinylbenzyl chloride.

19: The process according to claim 12, wherein the adding water comprises adding a defined amount of distilled water, and/or wherein the removing the alcohol and the hydrolysis alcohol comprises a distillative removal of the alcohol and the hydrolysis alcohol under vacuum at a bottoms temperature of less than 60° C.

20: The process according to claim 14, wherein the alcohol is ethanol or methanol.

Description

EXAMPLES

Determination of Molecular Weight:

[0072] Molar masses/molecular weights and also molar mass distributions may be determined by gel permeation chromatography (GPC). The GPC analysis method is described in detail in references including “Modern Size-Exclusion Liquid Chromatography”, Andre Striegel et al., Wiley & Sons, 2nd edn., 2009. Divinyltetramethoxydisiloxane, for example, may be used as a standard to calibrate the method for siloxane analyses.

Determination of SiO.SUB.2 .Content: Crucible Method:

[0073] The SiO.sub.2 content is determined by acid digestion with concentrated sulfuric acid and subsequent evaporation by fluorination.

GC Analysis:

[0074] In the context of GC standard analysis well known to those skilled in the art, the alcohol and hydrolysis alcohol content are determined using a suitable calibration and optionally an internal standard (for example nonane).

Example 1: Reaction Product of DAMO Oligomer (3.0 mol of H.SUB.2.O/mol of Si)/VBC (Vinylbenzyl Chloride) and Water

[0075] Apparatus: 2000 ml four-necked flask, dropping funnel, distillation bridge, intensive cooler, KPG stirrer, oil bath with temperature control, vacuum pump 126.3 g (0.568 mol) of DAMO ((2-aminoethyl)aminopropyltrimethoxysilane) and 62.0 g of methanol were initially charged in a 2000 ml four-necked flask. The bottoms temperature increased from 23° C. to 34° C. 30.7 g (1.705 mol) of DM (demineralized) water were added over three minutes. The bottoms temperature increased to 49° C. The mixture was stirred for a further hour at a bottoms temperature of 50° C. Subsequently, at a bottoms temperature of 55° C. to 58° C., 73.7 g (0.483 mol) of vinylbenzyl chloride (isomer mixture) were added over 2.4 h and the mixture was stirred for a further two hours at this temperature. The bottoms were subsequently diluted with 207.3 g of methanol. At a bottoms temperature of 20° C., addition of conc. hydrochloric acid (37%) was commenced. 60.9 g (0.618 mol) of concentrated hydrochloric acid were added over three minutes. The bottoms temperature increased to 37° C. The clear bottoms were then diluted with 578.9 g of DM water and methanol and hydrolysis methanol were removed by distillation at an absolute pressure of 200 mbar to 170 mbar and a bottoms temperature of 42° C. to 55° C. Altogether 660.9 g of distillate were removed and a further 24 g of DM water were added. 502.2 g of yellow, clear, low-viscosity bottoms product were obtained. The product remained clear and low-viscosity after an accelerated storage test (three weeks at 60° C., recirculating drying cabinet).

Analyses:

[0076]

TABLE-US-00001 TABLE 1 Determination Result Method Initial free methanol [% w/w] 0.1 see above SiO.sub.2 content 6.8 see above pH 2.7 DIN EN ISO 10523 colour number [Gardner] 8 ISO 4630 refractive index 1.4190 DIN 51423 viscosity (20° C.) [mPas] 137 DIN 53015 density (20° C.) [g/cm.sup.3] 1.100 DIN 51757 turbidity [FNU] 2.9 ISO 7027 3 weeks of storage at 60° C. viscosity (20° C.) [mPas] 257 DIN 53015 colour number [Gardner] 9 ISO 7027

Example 1 Molar Mass Distribution (Before Storage)

[0077] GPC column: PSS Novema Max. precolumn, column 2 and 3: PSS Movema Mac 100A, detector 1: Agilent RID G1362A, eluent: water, flow rate: 1 ml/Min, temp: 40° C.

TABLE-US-00002 TABLE 2 GPC M.sub.n 2.289 .Math. 10.sup.3 g/mol M.sub.w 1.141 .Math. 10.sup.4 g/mol M.sub.z 2.011 .Math. 10.sup.4 g/mol D 4.98 M.sub.p 1.202 .Math. 10.sup.4 g/mol

Example 2: Reaction Product of DAMO Oligomer (1.5 mol of H.SUB.2.O/mol of Si)/VBC (Vinylbenzyl Chloride) and Water

[0078] Apparatus: 1000 ml four-necked flask, dropping funnel, distillation bridge, intensive cooler, KPG stirrer, oil bath with temperature control, vacuum pump

[0079] 94.6 g (0.425 mol) of DAMO ((2-aminoethyl)aminopropyltrimethoxysilane) and 51.0 g of methanol were initially charged in a 1000 ml four-necked flask. The bottoms temperature increased from 23° C. to 34° C. A mixture of 11.5 g (0.638 mol) of DM water and 11.5 g of methanol was added over three minutes. The bottoms temperature increased to 49° C. The mixture was stirred for a further hour at a bottoms temperature of 50° C. Subsequently, at a bottoms temperature of 55° C. to 58° C., 55.4 g (0.363 mol) of vinylbenzyl chloride (isomer mixture) were added over 0.5 h and the mixture was stirred for a further two hours at this temperature. The bottoms were subsequently diluted with 26.1 g of methanol. At a bottoms temperature of 20° C., addition of conc. hydrochloric acid (37%) was commenced. 45.7 g (0.464 mol) of concentrated hydrochloric acid were added over four minutes. The bottoms temperature increased to 36° C. The clear bottoms were then diluted with 373.8 g of DM water and the hydrolysis methanol was removed by distillation at an absolute pressure of 200 mbar to 170 mbar and a bottoms temperature of 44° C. to 56° C. Altogether 291.8 g of distillate were removed and a further 34.8 g of DM water were added. 375.0 g of yellow, clear, low-viscosity bottoms product were obtained. The product remained clear and low-viscosity after an accelerated storage test (three weeks at 60° C.).

Analyses:

[0080]

TABLE-US-00003 TABLE 3 Determination Result Method Initial free methanol [% w/w] 0.2 see above SiO.sub.2 content 6.9 see above pH 2.7 DIN EN ISO 10523 colour number [Gardner] 8 ISO 4630 refractive index 1.4205 DIN 51423 viscosity (20° C.) [mPas] 207 DIN 53015 density (20° C.) [g/cm.sup.3] 1.102 DIN 51757 turbidity [FNU] 1.9 ISO 7027 3 weeks of storage at 60° C. viscosity (20° C.) [mPas] 217 DIN 53015 colour number [Gardner] 8 ISO 7027

Example 2 Molar Mass Distribution (Before Storage)

[0081] GPC column: PSS Novema Max. precolumn, column 2 and 3: PSS Movema Mac 100A, detector 1: Agilent RID G1362A, eluent: water, flow rate: 1 ml/Min, temp: 40° C.

TABLE-US-00004 TABLE 4 GPC M.sub.n 8.886 .Math. 10.sup.3 g/mol M.sub.w 1.104 .Math. 10.sup.4 g/mol M.sub.z 1.717 .Math. 10.sup.4 g/mol D 1.24 M.sub.p 1.200 .Math. 10.sup.4 g/mol

Comparative Example 1: Aqueous Hydrolysate of (N-vinylbenzyl-2-aminoethyl)aminopropyltrimethoxysilane Hydrochloride

[0082] Apparatus: 2000 ml four-necked flask, dropping funnel, distillation bridge, intensive cooler, KPG stirrer, oil bath with temperature control, vacuum pump

[0083] 499.5 g (0.605 mol) of (N-vinylbenzyl-2-aminoethyl)aminopropyltrimethoxysilane hydrochloride, 42% in methanol, were initially charged in a 2000 ml four-necked flask. 58.7 g of concentrated hydrochloric acid, 37% (0.645 mol HCL r.S./2.22 mol H.sub.2O), were added over 0.5 h. The bottoms temperature increased to 45° C. At an absolute pressure of 300 mbar to 130 mbar and a bottoms temperature of about 60° C. a total of 737.8 g of distillate were removed. 713.8 g of DM water were added during the distillation. 507.7 g of clear, yellow/reddish, low-viscosity product were obtained.

[0084] The product had solidified after 1 d of storage at 60° C. (in a recirculating drying cabinet).

Analyses:

[0085]

TABLE-US-00005 TABLE 5 Initial Determination Result Method free methanol [% w/w] <0.1 see above SiO.sub.2 content 6.9 see above pH 2.8 DIN EN ISO 10523 colour number [Gardner] 9 ISO 4630 viscosity (20° C.) [mPas] DIN 53015 density (20° C.) [g/cm.sup.3] 1.108 DIN 51757 turbidity [FNU].sup.1) 12.6 ISO 7027 .sup.1)measurement after 5 d of RT storage