DE102008054671A1 - Thermal crosslinking of organopolysiloxane compound present on a substrate with aldehyde reagent - Google Patents

Abstract

The invention relates to a method for crosslinking organopolysiloxane compound (S) having at least one group of the general formula (1) -R-NHR, with aldehyde reagent (A) of the general formula (2) O = CH-R in which in one first step with organopolysiloxane compound (S) and aldehyde reagent (A) a liquid (F) is prepared, in a second step the liquid (F) is applied to a substrate and in a third step the substrate is heated, wherein R, R is R in Claim 1 have given meanings, and the substrate containing the organopolysiloxane compound (S) crosslinked by the process with aldehyde reagent (A).

Description

The The present invention relates to a thermal crosslinking process of organopolysiloxane compound present on a substrate, which have amino groups, with aldehyde reagent.

silicones respectively silicone-containing formulations and composites are known and are in the form of films, coatings and coatings in large quantities for modification and equipment of various kinds Materials and fibers used. In their range of properties Silicone or silicone-containing formulations are purely organic Films, coatings and coatings in many Consider matters. This is how the use of silicone products leads to a vast extent not otherwise available but usually desirable properties such as Flow behavior, gas permeability, abrasion resistance, Hydrophobicity, smoothness, feel or shine of the treated Substrate.

One big problem of all coatings, but especially Of limited in their chemistry silicone coatings, that is often lack of adhesion to the respective treated substrate (so-called. Permanence of the coating). This causes the Coating either can be easily removed mechanically, about by rubbing or rubbing, or by chemical stress, for example, contact with various solvents and / or exposure certain pH environments (as occur, for example, in washing processes), can solve again from the substrate.

One Approach to solve the problem of lack of permanence, consists of the individual silicone polymer chains with each other as well as to crosslink with the substrate to be treated and in this way the mechanical and chemical resistance and thus increasing the permanence of the overall system.

The Crosslinking and binding to the substrate can both by non-covalent interactions and by covalent bonds take place.

Among the non-covalent interactions, hydrogen bonds in particular have become established. These provide, for example, formed in the form of urethane or urea groups within the group of thermoplastic silicone elastomers with each other for increased network density and by interaction with hydrogen bond forming groups of the substrate (eg, hydroxy units in cellulose surfaces) also for a certain fixation. The preparation and use of such silicone thermoplastic elastomers are, inter alia, in EP 0 606 532 A1 and EP 0 342 826 A2 described in detail.

Another noncovalent crosslinking mechanism relies on acid-base interactions between Lewis basic / Lewis acid groups of the silicone polymer with Lewis acidic / Lewis based groups of the substrate or polymer. Examples of these are amino-functional silicone oils which, as is known, have a positive influence, in particular, on the hydrophobicity and softness of textiles and, owing to their Lewis-basic amino functionalities, have the property of 'growing' onto the Lewis acidic fibers. Such silicone amine oils and their applications are, for example, in EP 1555011 A described.

Both Mechanisms are common that their generated permanence only is temporary and inadequate and the coating both mechanically and chemically easily removed can.

substantially better permanence is achieved when the fixation of polymer and substrate or crosslinking of polymer with each other through the Forming covalent bonds occurs.

A Covalent crosslinking can be effected, for example, in that the Silicone polymers already in the production by use of z. B. trifunctional building blocks are crosslinked. The polymers thus obtained However, they are characterized in their processing properties (eg. Melt viscosities, ductility, solubility in an application aid) adversely affected. Also Fixation to the substrate is usually no longer possible. Subsequent fixation / crosslinking following a successful application is therefore always more useful.

Such subsequent fixation / crosslinking may be effected, for example, by the presence of alkoxysilyl groups in the silicone polymer which provide better permanence by hydrolysis and condensation with hydroxy groups of the substrate or hydroxy groups of other silicone polymers. Such alkoxysilyl-containing silicone polymers are, for example, in EP 1544223 A1 described. The at the on Bonding to the substrate resulting Si-OC or Si-OE bonds (E = element of the substrate) are, however, usually hydrolysis-labile and therefore easy to reopen, whereby a good permanence is usually not given, especially in an aqueous environment. On the other hand, the formation of comparatively stable siloxane bonds Si-O-Si generally requires a previous treatment of the substrate with corresponding silanes.

In The paper and foil coating have two systems industrially established on thermally curable crosslinking mechanisms based.

The historically preferred form is mechanistically based on condensation crosslinking. This type of crosslinking is carried out by reaction of SiOH groups correspondingly Silicone polymers which react with SiH-containing crosslinkers with evolution of hydrogen, usually tin-catalyzed, crosslinked.

adversely in these systems is in addition to the unwanted formation of hydrogen the slow reaction time, so that usually when rolling up the coated goods, the silicone systems have not yet hardened are what, for example, to a back transfer of the silicone can lead. This in turn has due to Subsequent processes result in poor printability.

Mainly because of this, systems have become established in recent years which crosslink by means of a noble metal-catalyzed hydrosilylation reaction. In this case, alkylene-functionalized silicone polymers are used which vulcanize by means of noble metal (usually platinum) with a SiH-containing crosslinker without by-product formation. Within seconds, the reaction leads to a material that has hardened very well on an industrial scale. Exemplary here is on the font US 4772515 directed. Primarily due to the rapid rise in precious metal prices in recent years, the economic viability of this technology has been seriously challenged, leading to an intensive search for alternatives.

All coating systems used are multi-component, consisting in the minimum of a silicone polymer, a crosslinker and a catalyst. In noble metal-catalyzed systems also becomes an inhibitor needed, which generates an acceptable processing time. Above all, the balance of inhibition at room temperature with simultaneous high reactivity at elevated temperature Such systems generally appear disadvantageous.

The Systems can be solvent-based, solvent-free or be water-based. Due to the improved environmental and safety-related processing are solvent-free Prefer systems. Water-based systems are without alternative in direct siliconization during papermaking, since the aqueous production process is an analogous water-based Silicone system conditionally. Industrial emulsions are used.

Another crosslinking mechanism which is already known in the field of purely organic polymers concerns the so-called N-methylol crosslinking. In this case, polymers which carry N-methylolamide groups are produced by copolymerization with suitable monomers. These are known to bind covalently to alcoholic groups even at lower temperatures in the absence of water at elevated temperature or in the presence of acidic catalysts. Likewise, they can react with each other and thus cause a crosslinking of the polymer. In both cases, covalent ether bonds are formed, which are known to be very strong and are only broken again under extreme physical or chemical stress. This effect makes itself for example EP 0 143 175 A utilizing free radical emulsion polymerization to produce polymer dispersions which are postcrosslinkable via the methylol mechanism discussed above.

Although N-methylol groups can in principle be prepared by reacting amines units with formaldehyde, as a rule, however, the reaction leads to polymeric condensation products, so that ultimately polymeric networks result via imine intermediates. This reaction of amines with formaldehyde has already been described: US 3461100 describes condensation products of aldehydes and primary di- and monoamines. The resulting high polymer condensation products are discussed as protective coatings. DE 10047643 A1 describes polymeric condensation products of aldehydes and silicon amines, which, however, are exclusively high polymer and highly crosslinked.

In both documents, the product is already high polymer after implementation. It is thus no longer a reactive form, as it is the monoaddition product of a formaldehyde molecule to an amine, and thus stands for subsequent reactions on substrates or post-crosslinking Reakti no longer available to one another.

in the In contrast, stabilized silicone emulsions or stabilized Silicon solutions, the N-methylolated structural units include, in principle, a post-crosslinking in the above capable of being described.

So describes US 3432536 A the N-methylolation of terminal and lateral amidoalkyl polysiloxanes by treating them with aqueous formaldehyde solution in the presence of methanol to yield both the corresponding N-methylolamidoalkyl polysiloxanes and the corresponding N-methylol methyl ethers. Generally, however, such arid based N-methylols and especially their ethers often exhibit significantly reduced reactivities in the subsequent crosslinking and / or substrate fixation as compared to N-methylols derived from corresponding amines, carbamates or ureas.

The invention provides a process for crosslinking organopolysiloxane compound (S) which contains at least one group of the general formula (1) -R ¹ -NHR ² (1), having aldehyde reagent (A) of general formula (2) O = CH-R ³ (2), in which a liquid (F) is prepared in a first step with organopolysiloxane compound (S) and aldehyde reagent (A), in a second step the liquid (F) is applied to a substrate and in a third step the substrate is heated,
R ^{1 is} a divalent hydrocarbon radical having 1 to 20 C atoms, wherein the carbon chain may be interrupted by non-adjacent - (CO) -, -O-, -S- or -NR ⁷ groups and substituted with -CN or -halogen ;
R ^{2 is} a hydrogen atom, a hydrocarbon radical having 1 to 20 C atoms, a - (CO) -OR ⁴ group or a - (CO) -NR ⁵ R ⁶ group, the carbon chain being denoted by non-adjacent - (CO) -, -O-, -S- or -NR ⁷ groups may be interrupted and substituted with -CN or -halogen;
R ^{3 is} a hydrogen atom, a hydrocarbon radical having 1 to 20 carbon atoms, wherein the carbon chain is interrupted by non-adjacent - (CO) -, -O-, -S- or -NR ⁸ - groups and substituted with -CN or -halogen can be;
R ^{4 is} a hydrocarbon radical having 1 to 20 C atoms, wherein the carbon chain may be interrupted by non-adjacent - (CO) -, -O-, -S- or -NR ⁷ groups and may be substituted by -CN or -halogen;
R ^{5 is} a hydrogen atom, a hydrocarbon radical having 1 to 20 C atoms, wherein the carbon chain interrupted by non-adjacent - (CO) -, -O-, -S- or -NR ⁷ groups and substituted with -CN or -halogen may be covalently linked to R ⁶ ;
R ^{6 is} a hydrogen atom, a hydrocarbon radical having 1 to 20 C-atoms, wherein the carbon chain interrupted by non-adjacent - (CO) -, -O-, -S- or -NR ⁷ groups and substituted with -CN or -halogen may be covalently linked to R ⁵ ;
R ^{7 is} a hydrocarbon radical having 1 to 20 carbon atoms, wherein the carbon chain may be interrupted by non-adjacent - (CO) -, -O-, -S- or -NR ⁸ - groups and may be substituted by -CN or -halogen; and
R ^{8 is} a hydrocarbon radical having 1 to 20 C atoms;
with the proviso that either R ^{2 is} a hydrogen atom or at least one of R ¹ or R ² in the direct vicinity of their shared nitrogen atom carries a - (C = O) group.

The Method allows easy and fast networking on the Substrate, without the use of a noble metal catalyst.

The Method is suitable for both impregnation as well as for the coating with organopolysiloxane compound (S).

The Organopolysiloxane compound (S) may already partially react with the aldehyde reagent (A) react in the liquid (F), but the Crosslinking reaction on the coated or impregnated Substrate.

As aldehyde reagents (A) can be used, for. B. monomeric forms of formaldehyde, such as example, formaldehyde gas and aqueous or organic solutions of aldehydes, as well as formaldehyde in condensed form such as paraformaldehyde, trioxane, or other aldehyde condensates. However, the aldehyde can also be present in latent form and released in situ in the thermal crosslinking in the third step. All aldehyde-releasing agents are suitable for this purpose.

Also For example, an aldehyde derivative such as glyoxal can be used.

R ³ is preferably a hydrogen atom or alkyl or aryl radicals each having 1 to 10 C atoms, more preferably a methyl radical or a hydrogen atom.

R ¹ is preferably a divalent alkyl, cycloalkyl, alkenyl, aryl or arylalkyl radical, in particular alkyl radical having in each case 1 to 6 C atoms, more preferably -CH ₂ - and - (CH ₂ ) ₃ -.

R ² is preferably a hydrogen atom or an alkyl, cycloalkyl, alkenyl, aryl or arylalkyl radical having 1 to 20 C atoms, a - (CO) -OR ⁴ group or a - (CO) -NR ⁵ R ⁶ group, particularly preferably around the hydrogen atom.

R ⁴ is preferably an alkyl, cycloalkyl, alkenyl, aryl or arylalkyl radical, in particular alkyl radical having 1 to 6 C atoms, particularly preferably the methyl radical.

R ⁵ and / or R ^{6 are} preferably hydrogen atoms or alkyl, cycloalkyl, alkenyl, aryl or arylalkyl radicals, in particular alkyl radicals each having 1 to 6 C atoms, more preferably the hydrogen atom.

R ⁷ is preferably an alkyl, cycloalkyl, alkenyl, aryl or arylalkyl radical, in particular an alkyl radical having 1 to 6 C atoms, particularly preferably the methyl radical.

R ⁸ is preferably alkyl, cycloalkyl, alkenyl, aryl or arylalkyl radical, in particular an alkyl radical having 1 to 6 C atoms, particularly preferably a methyl radical.

The organopolysiloxane compound (S) used preferably contains units of the general formula (3) R ⁹ _a A _b SiO _{(4-ab / 2)} (3), in which
R ^{9 is} a hydrocarbon radical having 1 to 20 C atoms, wherein the carbon chain may be interrupted by non-adjacent - (CO) -, -O-, -S- or -NR ⁷ groups and may optionally be substituted by -CN or -halogen ;
R ^{7 has} the above meanings,
a is 0, 1, 2 or 3,
b is 0, 1, 2 or 3 and
A represents a group of the general formula (1),
with the proviso that the sum a + b is less than or equal to 3 and the organopolysiloxane compound (S) has at least one unit of the general formula (3) with b different zero.

R ⁹ is preferably alkyl, cycloalkyl, alkenyl, aryl or arylalkyl radicals, preferably alkyl or aryl radicals each having 1 to 6 C atoms, more preferably the methyl, ethyl, vinyl or phenyl radical ,

a is preferably 2 or 1 and b is preferably 0 or 1.

halogen radicals are in the context of the present invention preferably fluorine, chlorine, Bromine.

The Organopolysiloxane compound (S) includes both polymeric, oligomeric as well as dimeric organopolysiloxane compounds.

The Viscosity of the organopolysiloxane (S) is preferably at least 50, more preferably at least 100 mPa · s and preferably at most 5000, more preferably at most 1500 mPa · s, each at 25 ° C.

at the organopolysiloxane compounds (S) used are preferably to terminally linear polysiloxanes and / or pendant monovalent radicals A and / or chain divalent radicals A, where A is the abovementioned Meaning has. For the substantially linear polysiloxanes preferably at most 5%, in particular at most 1% of the siloxane units branching units.

The organopolysiloxane compounds (S) exhibiting particular preference are those of the general formula (4) A _e R ⁹ _3-e SiO- (SiR ⁹ ₂ O) _m - (SiAR ⁹ O) _n -SiR ⁹ ₃ -e A _e (4) in which
A and R ^{9 have} the meanings given above;
e is 0 or 1;
m is 0 or an integer of 1 to 200;
n is 0 or an integer from 1 to 200 and
m + n is 0 or an integer of 1 to 400;
with the proviso that at least one radical A is present per molecule.

Preferably, in the general formula (4), the individual units (SiR ⁹ ₂ O) _m and (SiAR ⁹ O) _{n are} randomly distributed in the molecule.

m + n is preferably at least 5, more preferably at least 8 and preferably at most 500, more preferably at most 250th

The ratio of the groups A: R ⁹ is preferably at least 1: 10,000, in particular at least 1: 1000 and preferably at most 1: 5, in particular at most 1:30.

Crosslinking of the organopolysiloxane compound (S) with the aldehyde reagent (A) gives crosslinking units of the general formula -R ¹ -NR ² -CHR ³ -NR ² -R ¹ -.

Dependent from the speed of the crosslinking reaction, essentially due to the reactivity of the organopolysiloxane compound (S), it may also be advantageous that liquid (F) contains a catalyst for the crosslinking reaction. In principle, all Lewis and Bronsted acids are suitable as catalyst. These can be added directly to the silicone or be applied as a separate component.

If the liquid (F) is a solution of aldehyde reagent (A) in Organopolysiloxanverbindung (S), is preferably at their preparation, a solubilizer added, the towards organopolysiloxane compound (S) and aldehyde reagent (A) is inert. As a solubilizer are preferred here Ethers, such as tetrahydrofuran and dioxane, hydrocarbons, such as toluene and xylene, chlorinated hydrocarbons, ketones, such as acetone and Methyl ethyl ketone and esters, and mixtures thereof. solubilizers with a boiling point or boiling range of up to 120 ° C at 0.1 MPa are preferred.

The Liquid (F) is preferably a solution or a dispersion, in particular emulsion or suspension, respectively the organopolysiloxane compound (S) and aldehyde reagent (A).

If the liquid (F) is an emulsion or suspension their preparation with aldehyde reagent (A) familiar to those skilled in the art Methods.

at The preparation of the emulsion or suspension is organopolysiloxane compound (S) and aldehyde reagent (A) preferably in one opposite Organopolysiloxane compound (S) and aldehyde reagent (A) inert solvent emulsified or suspended. Preferably, organopolysiloxane compound (S) is first emulsified or suspended and then the aldehyde reagent (A) added. The solvents are the above mentioned solubilizer and water preferred.

Based to all NH units in the groups of the general formula (1) are used in fluids (F) that are an emulsion or suspension or solution, preferably at least 0.3, in particular at least 0.7 aldehyde groups of the general formula (2) used.

Based to all NH units in the groups of the general formula (1) are used in fluids (F) that are an emulsion or suspension or solution, preferably at most 5, in particular at most 1.3 aldehyde groups of the general formula (2) used.

Preferably Be the liquids (F), especially those who are a solution added stabilizers, which are the prevent premature networking.

When Stabilizers preferred are aliphatic alcohols having 1 to 10 Carbon atoms, preferably with a boiling point or boiling range of up to 150 ° C at 0.1 MPa, such as methanol, ethanol, isopropanol and n-butanol.

The impregnated with the crosslinked organopolysiloxane compound (S) or coated substrates, preferably papers and films for example, for all classic release applications be used. Exemplary, label applications, baking paper, medical area, tapes, hygiene and graphic Area are called.

at impregnated with the crosslinked organopolysiloxane compound (S) or coated substrates may, for example, to Textiles and leather trade.

If In the process of paper coating, the liquid can (F) already right after the paper making process on the still wet paper are applied.

The impregnated with the organopolysiloxane compound (S) or coated substrates can also finely divided, z. B. Powder or granules, and by the organopolysiloxane compound (S) be bonded as a binder to a shaped body.

in the third step, the substrate is preferably at least 80 ° C, in particular at least 100 ° C and preferably at most Heated to 180 ° C. The heating preferably lasts at least 10 seconds, especially at least 30 seconds, and preferably at most 10 min.

object The invention also includes the substrate containing by the method organopolysiloxane compound (S) crosslinked with aldehyde reagent (A).

Examples

So far Unless otherwise indicated, all amounts and percentages are based on based on weight, all pressures 0.10 MPa (abs.) and all Temperatures 2000.

1. Preparation of silicone emulsions

Tabelle 1: Emulsion aus (Aminoalkyl)polydimethylsiloxan 1 (Aminoalkyl)polydimethysiloxan 1 Emulgator Wasser Formaldehyd-Lösung Mittlere Tröpfchengröße Aminäquivivalent Viskosität Menge Konzentration Menge Menge Menge (mmol/g) (mm²/s) (g) (%) (g) (g) (g) (nm) 0,27 513 100 80 21 480 2,17 240 From the (aminoalkyl) polydimethylsiloxane 1 (see Figure 1 & Table 1), a suitable emulsifier (solution in water) and demineralized water according to the common prior art known in the art using a Hochleistungsdispergiergeräts (eg., Ika Ultra-Turrax ^® ) an oil-in-water emulsion. With gentle stirring, an aqueous solution of formaldehyde (37%) is then added to the emulsion. It was then determined the droplet size. Figure 1: (Aminoalkyl) polydimethylsiloxane 1

Table 1: Emulsion of (aminoalkyl) polydimethylsiloxane 1 (Aminoalkyl) polydimethysiloxane 1 emulsifier water Formaldehyde solution Medium droplet size Aminäquivivalent viscosity amount concentration amount amount amount (Mmol / g) (mm ² / s) (G) (%) (G) (G) (G) (Nm) 0.27 513 100 80 21 480 2.17 240

2. Preparation of silicone solutions

2.1 Solvent-containing, stabilized

6.0 g of (aminoalkyl) polydimethylsiloxane 1 are dissolved in 4.0 g of THF and treated with 6.0 g of n-butanol. For this one gives under continuous Stir 0.23 g of aqueous solution of formaldehyde (37%) in 2.0 g THF. It results in a 25 ° C over storage-stable, homogeneous silicone solution for several days.

2.2 Solvent free

2.74 g of (aminoalkyl) polydimethylsiloxane 1 are stirred added with 0.54 g octanal. It results in a 25 ° C over several hours storage-stable, slightly cloudy silicone solution.

3. Application of silicone emulsions

Emulsions from example 1 are applied with a 20 μm doctor blade to a glassine paper substrate (see Table 2). Subsequently, the coated papers are cured at 150 ° C for 120 s (1.1) or 240 s (1.2) in an oven and freed from water. The resulting siliconized papers are tested according to standard FINAT methods (see Table 2). Table 2: Application test of silicone emulsions on glassine paper Silca Classic (Ahlstrom company) No. Rub-off (school grade scale) Migration (school grade scale) Smear (grading scale) Release force [Nm] Adhesive A7475 Release force [Nm] Adhesiv K7476 1.1 1 1 1 57.0 106.2 1.2 1 1 1 48.1 65.0

4. Application of silicone solutions

4.1 paper coating

The solutions of Example 2 are coated with a 20 μm doctor blade on a glassine paper substrate (see Table 3). Subsequently, the coated paper is cured for 2 min at 150 ° C in an oven and freed from the volatile components. The resulting siliconized papers are tested according to standard FINAT methods (see Table 3). Table 3: Application test of silicone solutions on glassine paper Silca Classic (Ahlstrom company) No. Rub-off (school grade scale) Migration (school grade scale) Smear (grading scale) Release force [Nm] Adhesive A7475 Release force [Nm] Adhesiv K7476 2.1 1 1 1 7.2 30.3 2.2 1 1 1 21.4 16.2

4.2 Film coating

The silicone solution from Example 2.1 is applied using a 20 μm doctor blade to various corona-pretreated film substrate types (see Table 4). Subsequently, the coated films 30 Cured at 95 ° C in an oven and freed from the volatiles. The resulting siliconized films are tested according to standard FINAT methods (see Table 4). Table 4: Application test of the silicone solutions on films Foil type Rub-off (school grade scale) Migration (school grade scale) Smear (grading scale) Release force [Nm] Adhesive A7475 Release force [Nm] Adhesiv K7476 RN 36 PET Mitsubishi 1 1 1 11.3 46.3 CR 50 BOPP Innovia 1 1 1 12.9 51.8 HDPE orbit 1 1 1 12.7 44.7

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0606532 A1 [0006]
• EP 0342826 A2 [0006]
• EP 1555011 A [0007]
• EP 1544223 A1 [0011]
• US 4772515 [0015]
• EP 0143175A [0018]
• - US 3461100 [0019]
• - DE 10047643 A1 [0019]
• - US 3432536 A [0022]

Claims (9)

Process for crosslinking organopolysiloxane compound (S) containing at least one group of general formula (1) -R ¹ -NHR ² (1), having aldehyde reagent (A) of general formula (2) O = CH-R ³ (2), in which a liquid (F) is prepared in a first step with organopolysiloxane compound (S) and aldehyde reagent (A), in a second step the liquid (F) is applied to a substrate and in a third step the substrate is heated, wherein R ^{1 is} a divalent hydrocarbon radical having 1 to 20 carbon atoms, wherein the carbon chain may be interrupted by non-adjacent - (CO) -, -O-, -S- or -NR ⁷ groups and may be substituted by -CN or -halogen; R ^{2 is} a hydrogen atom, a hydrocarbon radical having 1 to 20 C atoms, a - (CO) -OR ⁴ group or a - (CO) -NR ⁵ R ⁶ group, the carbon chain being denoted by non-adjacent - (CO) -, -O-, -S- or -NR ⁷ groups may be interrupted and substituted with -CN or -halogen; R ^{3 is} a hydrogen atom, a hydrocarbon radical having 1 to 20 carbon atoms, wherein the carbon chain is interrupted by non-adjacent - (CO) -, -O-, -S- or -NR ⁸ - groups and substituted with -CN or -halogen can be; R ^{4 is} a hydrocarbon radical having 1 to 20 C atoms, wherein the carbon chain may be interrupted by non-adjacent - (CO) -, -O-, -S- or -NR ⁷ groups and may be substituted by -CN or -halogen; R ^{5 is} a hydrogen atom, a hydrocarbon radical having 1 to 20 C atoms, wherein the carbon chain interrupted by non-adjacent - (CO) -, -O-, -S- or -NR ⁷ groups and substituted with -CN or -halogen may be covalently linked to R ⁶ ; R ^{6 is} a hydrogen atom, a hydrocarbon radical having 1 to 20 C-atoms, wherein the carbon chain interrupted by non-adjacent - (CO) -, -O-, -S- or -NR ⁷ groups and substituted with -CN or -halogen may be covalently linked to R ⁵ ; R ^{7 is} a hydrocarbon radical having 1 to 20 carbon atoms, wherein the carbon chain may be interrupted by non-adjacent - (CO) -, -O-, -S- or -NR ⁸ - groups and may be substituted by -CN or -halogen; and R ^{8 is} a hydrocarbon radical of 1 to 20 carbon atoms; with the proviso that either R ^{2 is} a hydrogen atom or at least one of R ¹ or R ² in the direct vicinity of their shared nitrogen atom carries a - (C = O) group. The method of claim 1, wherein as aldehyde reagent (A) Formaldehyde is used. A process as claimed in claim 1 or 2, wherein R ^{1 is} -CH ₂ - or - (CH ₂ ) ₃ -. The method of claim 1 to 3, wherein R ^{2 represents} a hydrogen atom. Process according to Claims 1 to 4, in which the organopolysiloxane compounds (S) have the general formula (4) A _e R ⁹ _3-e SiO- (SiR ⁹ ₂ O) _m - (SiAR ⁹ O) _n -SiR ⁹ ₃ -e A _e (4) wherein A and R ^{9 have} the meanings given in claim 1; e is 0 or 1; m is 0 or an integer of 1 to 200; n is 0 or an integer of 1 to 200, and m + n is 0 or an integer of 1 to 400; with the proviso that at least one radical A is present per molecule. The method of claim 1 to 5, wherein the substrate heated to 80 ° C to 180 ° C in the third step. The method of claim 1 to 6, wherein the liquids (F) aliphatic alcohols having 1 to 10 Koh lenstoffatomen be added as stabilizers. Substrate, containing by the method according to Claims 1 to 7 organopolysiloxane crosslinked with aldehyde reagent (A) (S). Substrates according to claim 8, selected be made of papers and transparencies.