DE10057554B4 - Stabilizing and / or stabilizing agents, strengthening / stabilization methods and use - Google Patents

Abstract

setting agents and / or stabilizing agent for organic material containing at least one silylated derivative of hydroxyl and / or carboxy and / or amino groups Compounds in a nonpolar solvent, comprising polysaccharides, Carbohydrates and their derivatives, starch and starch derivatives, hemicellulose and hemicellulose derivatives, galactomannans and galactomannan derivatives, Guar and guar derivatives, chitin and chitin derivatives, chitosan and chitosan derivatives, dextrans and dextran derivatives, dextrins and dextrin derivatives, xanthans and Xanthan derivatives, polyvinyl alcohol and polyvinyl alcohol derivatives, partially hydrolyzed polyvinyl acetate, gelatin and gelatin derivatives or polyethyleneamines and their derivatives, with the proviso that the polysaccharide is not cellulose.

Description

The The present invention relates to setting agents and / or stabilizers for organic Material, a method for strengthening / stabilization of organic Material and the use of strengthening or stabilizing agents.

All made of organic materials made of paper, wood or textiles are subject to more or less severe aging or decomposition. This z. B. paper mainly by acids, but also by oxidation processes or by the influence of microorganisms destroyed. However, despite significant progress in recent years, however Main problems, such as paper consolidation from non-aqueous Media, in the conservation and restoration of books and Documents essentially unresolved.

The Consolidation or stabilization of old, brittle organic materials, especially papers, is one of the key issues in the Preservation and restoration of these materials. While for the deacidification of Paper successfully new opportunities up to the mass de-acidification process were developed, there is no satisfactory in the field of consolidation Processes that allow paper consolidation, in particular entire book blocks and as possible at the same time also the deacidification serve the paper.

It is known to be strong damaged Papers through the paper-splitting process (see Helmut Bansa, Ritsuko Ishii: "The Effect of Different Strengthening Methods on Different Kinds of Paper ", restorer 18 (1997), 51-72) can be strengthened again. In this process, the paper becomes split and together with a thin liner and a special adhesive, the cellulose ether and a deacidifying agent contains glued again. However, this very effective consolidation method is associated with a very high manual effort and thus expensive. Although it is due to a mechanical paper splitting possible, However, the cost is also reduced in this process considerable effort is required as a book in the individual pages has to be disassembled, before the individual papers can be split, as only a split individual pages possible is.

Known is also the solidification of brittle Paper by soaking the paper with Acylsäurederivaten and by irradiation with gamma rays to the polymerization brings (see. L. W. Lynch: "High-Strength Cellulosic Materials Through Internal Polymerization ", Tappi 46 (1963), 480-485) Addition of amine-substituted acrylic methacrylate can thereby the paper be deacidified to a limited extent. Disadvantage of this However, the method is the further damage to the already fragile paper by the gamma radiation, the bleeding out of colors and inks the watering with acrylic acid derivatives as well as the odor nuisance the remaining in the paper residue monomers or oligomers, which moreover unhealthy are.

Also Lamination stabilizes paper by melting or sticking a thin one Polymer film applied on one side or both sides of the paper becomes. The disadvantage of this single-sheet process is the increasing Paper thickness, so that after Treatment and consolidation of the book cover no longer fits. Another side effect is the grip and the look of the paper changed significantly and the resistance the polymers used is not secured. Moreover, there is no simultaneous deacidification or a mass treatment possible.

At the Parylene method (see Henry A. Carter: "The Chemistry of Paper Presentation Part 3. The Strengthening of Paper, Journal of Chemical Education 73 (1996), 1160-1162) the paper consolidation is carried out from the gas phase without solvent. This The process developed by the Union Carbide Corporation is mainly used in used in the electronics industry. In this known method will be the first stable parylene dimer at 150 ° C evaporated under vacuum and then at 650 to 690 ° C in the reactive monomers split. The reactive gas is then added to or over the directed to the object to be treated, on and in which it then polymerizes. The polymer penetrates into the paper into the pores and forms a stabilizing network around the paper fibers. By the high Degree of crosslinking of the polymer is not soluble in any solvent. Therefore the treatment is irreversible, d. H. the polymer can not work anymore be removed. Furthermore this simultaneous deacidification is not possible with this method.

An increase in strength of a paper up to 100% has also been achieved by the Battelle Institute with hexamethyl diisocyanate as a consolidator. However, isocyanates are not compatible with any known soluble deacidifying agent and, when applied directly to the paper, form crosslinked polyureas, Another disadvantage being the hardness increase of the paper (compare I. Kopp, H. Träubel, E. Wenderoth: "Isocyanate Derivatives in Paper Finishing", Wochenblatt fur Papierfabrikation (1996), 379-383).

The classical conservatory method for the stabilization of aged Paper is re-gluing. In the process, solutions of a great variety of water-soluble Polymers, especially cellulose or starch ethers, gelatin, but also Polyvinyl alcohols or polyacrylates, applied to the paper. Methylcellulose has been found to be best in the aqueous treatment proven, while in the treatment with alcohol as a solvent hydroxypropylcellulose is used.

As The methylcellulose are also almost all others in paper restoration Resilient polymers soluble in water only, except alcohol-soluble high substituted hydroxypropyl cellulose, ethyl cellulose and methyl cellulose. A problem arising in relining is thus the fact that sensitive Do not use paper containing water or alcohol-soluble inks or inks can be nachgeleimt (See J. Strnadova, M. Durovic: "The Cellulose Ethers in Paper Conversation ", restorer 15 (1994), 220-241).

Out DD 299 314 A5 there is known a process for the preparation of O-trialkylsilylcelluloses wherein the hydroxyl- and / or carboxy- and / or amino-containing compounds comprise cellulose. Moreover, this reference does not indicate the use of the organosilicon compounds as setting agents for the preservation and restoration of papers, wood, textiles, inks and inks, as well as for the fixation of soluble inks prior to aqueous treatment.

The JP 48092615 A describes a process for producing a hydrophobic photographic paper by immersion in a solution of trimethylsilyl cellulose in hexane. However, silylated hydroxyl and / or carboxy and / or amino-containing compounds are not disclosed at any point. Also, the use of the known solution of trimethylsilyl cellulose in hexane for the preservation and restoration of papers, wood, textiles, paints and inks, as well as for the fixation of soluble inks before an aqueous treatment is not apparent from this document.

From the DE 195 437 07 A1 For example, a method for preserving paper is known wherein the paper is contacted with a preservative liquid containing organosilyl compound and then dried and / or cured. However, the described organosilyl compounds are not comparable to those used according to the invention. The use of a setting agent for the preservation and restoration of papers, wood, textiles, paints and inks, as well as for the fixation of soluble inks before an aqueous treatment is not removable from this prior art.

The EP 401 668 A2 discloses silylated derivatives of polysaccharides, which are not related to the use of these silylated derivatives in a non-polar solvent as strengthening and / or stabilizing agents for organic material, nor a method for strengthening organic material or use for the preservation and restoration of Papers, wood, textiles, paints and inks, as well as for the fixation of soluble inks before an aqueous treatment.

task It is therefore an object of the invention to provide a consolidant and / or stabilizer, a method of strengthening and / or stabilizing organic Material in the mass and the use of this tightening agent to provide for the preservation and restoration of organic material, in which prevents the further decomposition of the organic material and the re-stabilization by deacidification and consolidation in one Can take place as well as the stabilization of fragile objects reached ready-to-use material.

According to the invention this Task by the claims 1, 5 and 8 solved. Preferred developments emerge from the subclaims.

According to the invention becomes a firming agent for provided organic material containing a silylated derivative a hydroxyl and / or amino-containing compound in a nonpolar solvent contains. With this use according to the invention Is it possible, the previously only water-soluble Post-sizing agent by a temporary (intermediate) chemical Modification in nonpolar solvents soluble too do. By the temporary Masking the polar hydroxyl and amino groups with nonpolar substituents, which can easily be split off, the polarity of the compounds used in the invention lowered and in addition a compatibility with the deacidifying agent be achieved.

The inventive agent acts opposite hydrolysis-sensitive deacidifying agents as a protective colloid and delayed hence the reaction of this deacidifying agent with water. This is the uniform distribution of the deacidifying agent promoted with paper, although the predrying of the paper before deacidification not needs to be more that extreme.

By the degree of silylation of the various polyhydroxy compounds the solubility be selectively controlled, in principle solvents of various polarity can be used universally. The higher the degree of silylation, the more non-polar the solvent must be. So are the used according to the invention modified polyhydroxy compounds usually to almost all solvent conformable to supercritical Carbon dioxide as a solvent.

The Combinations of silylated cellulose ethers with METE (= magnesium-titanium-ethanolate) show one amazing further effect. The strong interaction between the polyvalent cations of the deacidifying agent and the re-sizing agent also has a positive effect on the distribution of the deacidifying agent out on paper.

solution can be Apply lightly to paper that has not dried without adding too much an immediate hydrolysis comes. The hydrophobic silylated cellulose agents wrap the deacidifying agent, whereby it is protected against the moisture and the hydrolysis is delayed. moreover form the silylated polyhydroxy compounds, in particular the silylated cellulose ether, with the METE a transparent film, which also causes the formation of coarse crystallites from the deacidifying agent is prevented.

While that not pre-dried, only with METE deacidified paper completely with fine crystallites of the hydrolysed deacidifying agent is occupied, are at with a combination of silylated polyhydroxy compounds and METE treated paper no crystalline deposits of deacidifiers to recognize.

by virtue of this is also the case of mass deacidification with an addition of such Means a reduction of pre-drying possible, which not only time saved, but also positive effects on the paper occur since a less extreme drying also at a lower Cornification leads.

For the without Predrying carried out Open cut sheet treatment about it also completely new Options, as it is now possible is, for. B. with METE from nonpolar solvents materials directly to deacidify.

When for the Invention suitable silylating agents are organosilyl compounds shown, with the masking of the hydroxyl groups usually too Trialkylsilyl ethers, usually trimethylsilyl ethers, a suitable Method represents. As the silylating agent, among others, trimethylchlorosilane or hexamethyldisilazane, using trialkylsilyl groups are preferred.

For the purpose of the invention have become hydroxyl-carboxyl or amino groups containing compounds polysaccharides, carbohydrates and their Derivatives, such as alkyl glycosides (eg butyl glucoside, octyl glucoside) and alkyl polyglycosides, cellulose and cellulose derivatives (eg cellulose ethers), Strength and starch derivatives (e.g. Starch ethers), Hemicellulose and hemicellulose derivatives, galactomannans and galactomannan derivatives, Guar and guar derivatives, chitin and chitin derivatives, chitosan and chitosan derivatives, Dextrans and dextran derivatives, dextrins and dextrin derivatives, xanthans and xanthan derivatives, polyvinyl alcohol and polyvinyl alcohol derivatives, partially hydrolyzed polyvinyl acetate, gelatin and gelatin derivatives or polyethyleneamines and their derivatives as promising shown. The conversion z. As the cellulose or the cellulose derivative into the corresponding silylated cellulose derivative makes the resulting Compound in nonpolar solvents soluble.

When nonpolar solvents In particular, organic solvents such as alkanes, alkenes or Hexamethyldisiloxane (HMDO), supercritical Carbon dioxide or halogenated hydrocarbons as suitable where the persilylated or nearly persilylated Hydroxyl- or amino-containing compounds, e.g. B. polysaccharides or the like, solve well and this as a solution also with those in mass deacidification used deacidifying agents compatible are.

By the blocking of the hydroxyl groups are also the silylated compounds compatible with hydrolysis-sensitive deacidifying agents such as magnesium alcoholates, Titanium / magnesium alcoholates or the like which are present in the various deacidification be used.

This derivatization opens up a broad spectrum for paper treatment from nonpolar solvents. With the aid of the consolidating agent according to the invention, it is possible in this case to modify all common pasting agents already used in paper restoration and to solubilize them in non-polar solvents according to the following formula:

When Firming agents can so the conventional ones Post-gluing, which has been successful in the aqueous re-sizing be used after an intermediate derivatization in a corresponding organosilyl derivative can be used. Already can existing experiences about the compatibility of this Substances taken over with the paper and their aging behavior become. These substances thus also correspond to the high degree of restoration Conditions.

With This method also allows new additives in the chemical system mass deacidification do not yet integrate because of their polar character were used. about an intermediate silylation the polar hydroxyl, amine or Carboxyl functions can also here these groups are masked. In this way silylated antioxidants, complexing agents (metal ion deactivators), Radical scavengers, Light stabilizers (UV stabilizers), Peroxidzersetzer, Antiozonantien or pesticides, in particular fungicides, bactericides or insecticides, Install in the mass deacidification chemical system.

If these substances come into contact with moisture or water, even from the air, after the treatment, the silyl group introduced by the chemical modification is slowly split off again and escapes as a volatile substance. Are z. B. trimethylsilyl ether of the corresponding hydroxyl compound is formed as a volatile leaving substance ultimately hexamethyldisiloxane (HMDO), which can be used as a solvent in the deacidification process. Cell-O-Si (Me) ₃ + H ₂ O → Cell-OH + HO-Si (Me) ₃

The Hydrolysis of the unstable (cellulose) silyl ether is by acids, but also catalyzed by bases. Persilylated polysaccharide derivatives are relatively stable and hydrolyzed by their hydrophobic character only very slowly. Due to the bulky trimethylsilyl groups can Water difficult to reach the ether-oxygen atom (steric hindrance). On the other hand, celluloses hydrolyze with a medium degree of substitution (MS) of 1.5 or less very fast, since with them this steric Hinder is not present. Here no catalysis is necessary because within a few hours these compounds already through the Hydrolyze humidity. So one observes at persilylated Celluloses only a very slow hydrolysis, which increases with increasing Hydrolysis rate continues to accelerate.

On the Degree of substitution (degree of silylation) it is possible, on the one hand the solubility of (polyhydroxy) compounds, in particular polysaccharides, of polar (water) to nonpolar (petroleum ether) to vary and on the other hand to control the hydrolysis sensitivity targeted.

at deacidification and consolidation by means of the solidifying agent according to the invention for strengthening by Resilusion with silylated cellulose ethers from nonpolar solvents ultimately remain after hydrolysis by the humidity only the now unmodified substances on the paper together with the deacidification substance. This also applies to all other silylated additives.

to Consolidation of paper in mass deacidification has become particularly Persilylated, low molecular weight methylcelluloses in concentrations from 0.01 to 5 wt .-%, in particular 0.5 wt .-% in the treatment solution as proved suitable. In brittle, keratinized papers can be made by addition of 0.001 to 0.5 wt .-%, preferably 0.1% by weight, persylylated butyl glucoside a positive Effect on the flexibility be achieved.

ever according to the purpose of treatment still by the addition of antioxidant, the resistance of the Paper opposite oxidative degradation processes can be improved.

On that way - over one temporary chemical modification - the from the aqueous treatment known substances can also be used from nonpolar solvents, being through the compatibility with hydrolysis-sensitive deacidifying agents a simultaneous deacidification of the organic material to be treated is possible.

With the agent of the invention is a conservation and restoration of papers; Wood, textiles, Paints and inks, as well as a fixation of soluble inks before an aqueous treatment possible.

The invention is explained in more detail below with reference to the examples:
The paper sheets were coated on both sides in the following Examples 1 and 2 without predrying directly with the strengthener and deacidifier. The addition of additive in the consolidant solution is 2% by weight in all experiments, if no additional information is given. The paper used was naturally aged, acid-sized wood pulp paper from 1961.

The results of the paper strengths were determined by tensile elongation test in the direction of the papers as work acceptance [J / m ² ]. The samples were tested for mechanical strength both immediately after treatment and after a five week (35 days) artificial aging at 80 ° C, 65% relative humidity.

in the following stands the abbreviation "-Si" for the silylated Derivatives of the corresponding compound.

example 1

Deacidification and consolidation with magnesium monobutyltriglycol ether carbonate (Lithco, FMC) as a deacidifying agent

Out It is known from the literature that the monobutyl triglycol ether as Magnesium Alcoholate (MG3) in Deacidifier from Lithco (FMC) to have a firming effect on the paper. The results of a comparative Investigation, however, showed that no additional Stabilizing effect of MG3 on naturally aged groundwood paper (Federal budget 1961) entered, on the contrary, directly after the Treatment, there was a small (slight) strength drop.

• HPC = Hydroxypropylcellulose (MS ~ 5) Tabelle 1
  

In the table below, the corresponding experiments are indicated, wherein as FMC deacidification solution 0.05 moles of MG3 per liter of petroleum ether were used.

• HPC = hydroxypropylcellulose (MS ~ 5) Table 1
  

The Silylated cellulose derivatives compensate for part of the deacidification-related Loss of strength. Split in the course of artificial aging At the cellulose ethers, the silyl groups are derived, the molecules becoming more polar become stronger and thus stronger Can form interactions with the paper fibers. As a result of it rises the strength of the paper. So have with tightening and deacidifying agents treated papers after artificial Aging a higher one Strength than the untreated paper before artificial aging.

Example 2

Deacidification and consolidation with magnesium-titanium-ethanolate (METE) in HMDO as a deacidifier for single sheet treatment (without pre-drying):

at These attempts were as deacidification a 0.05 molar solution used by METE in HMDO. This deacidifying agent has been in the deacidification proven for several years.

Table 2

As Table 2 above shows the use of silylated Cellulose ethers to a significant improvement in strength.

Nice when applying the solutions on the papers is the effect of these additives as a protective colloid for the deacidifiers clear. Without additive it comes with this kind of application to a immediate hydrolysis of the deacidifier on the paper surface, the papers then being of a white dusty layer of fine crystalline hydrolyzed deacidifying agent are covered.

By the solidifying agent used in the invention, in the present case a silylated cellulose ether, the hydrolysis of the deacidifying agent is significantly delayed. The hydrophobic silylated cellulose ethers coat the deacidifying agent. This protects it against moisture and retards hydrolysis. The treatment solution is easily applied to the (not pre-dried) paper without causing immediate hydrolysis. The silylated cellulose ethers form a transparent film with the METE. This is also shown by the following scanning electron micrographs. While the paper deacidified with METE is completely coated with fine crystallites of the hydrolysed deacidifying agent ( 1 ), the paper treated with a combination of silylated cellulose ether and METE shows no crystalline deposits of the deacidifying agent ( 2 ). The formation of a film and the use of a deacidifying agent do not result in dusty deposits of the hydrolyzed deacidifying agent on the paper.

On this way (see Examples 1 and 2) can now very sensitive to hydrolysis deacidifiers the mass deacidification process, even without predrying of the paper, directly in the single sheet treatment be used.

Example 3

Deacidification and consolidation with METE in HMDO as a deacidifying agent in mass treatment

For the treatment whole book blocks became the common one Massenentsäuerungsmethode the German library (Leipzig) taken in almost all steps. The treatment solution (METE in HMDO) various silylated additives were added. The Results are summarized in Table 3.

Table 3

As From the table above, leads the consolidant of the invention for organic Material to a significant and lasting improvement of the mechanical Firmness of the paper.

By the protective colloid effect of the silylated polyhydroxy compounds the hydrolysis-sensitive deacidifying agent may be hydrolysed the deacidifying agent delayed so much be that one so extreme pre-drying, as is common today, in mass deacidification not more is necessary.

Example 4

Consolidation of wooden objects

Old and partly rotten wood articles, in which the cellulose content has already largely decomposed are persylated with a pentane dissolved Trimethylsilyl cellulose (TMSC) treated. After filling the cavities in the wooden article with this solution, e.g. through a vacuum impregnation, evaporated the volatile one Pentane.

TSMC hydrolyzed in about 6 months at room temperature to pure cellulose. The cellulose formed in this way lies inside the wood again before, which thus as a fiber-forming semi-crystalline substance again to a considerable Stabilization of the wood contributes.

Example 5

Fixation of solvent-sensitive Paints and inks in front of a watery treatment

In Water easily bleeding inks and inks, such as stamping inks, can before an aqueous treatment be fixed with highly substituted Polysaccharidsilylethern. The effectiveness is best when the paper to be treated in the appropriate places on both sides with a solution of highly substituted Polysaccharidesilylethern is coated. The paper will be attached to this Make it so hydrophobic that no polar solvent (Water) more reaches the colors and inks and thus bleeding omitted. Here too, simultaneously with a deacidifying agent, that too in the treatment solution solved is, e.g. METE paper is deacidified at these areas.

Preferably is, depending on the molecular weight / viscosity of the silylated cellulose ether a 0.5 to 5 wt .-% solution with heptane or pentane as solvent used.

Claims (8)

Strengthening and / or stabilizing agent for organic Material containing at least one silylated derivative of hydroxyl and / or carboxy- and / or amino-containing compounds in a nonpolar solvent, comprising polysaccharides, carbohydrates and their derivatives, starch and Starch derivatives, hemicellulose and hemicellulose derivatives, galactomannans and galactomannan derivatives, Guar and guar derivatives, chitin and chitin derivatives, chitosan and chitosan derivatives, Dextrans and dextran derivatives, dextrins and dextrin derivatives, xanthans and xanthan derivatives, polyvinyl alcohol and polyvinyl alcohol derivatives, partially hydrolyzed polyvinyl acetate, gelatin and gelatin derivatives or polyethyleneamines and their derivatives, with the proviso that the polysaccharide is not cellulose. Stabilizing and / or stabilizing agent according to claim 1, characterized in that the Silyl groups are organosilyl compounds. Stabilizing and / or stabilizing agent according to claim 1 or 2, characterized in that the nonpolar solvent an organic solvent is. Firming agent according to one of claims 1 to 3, characterized in that the Consolidator contains additives. Method of strengthening organic material, characterized in that the to be treated organic material in a solution of the solidifying agent is introduced according to claim 1. Method of stabilizing organic material according to claim 5, characterized in that the solution of the consolidating agent additionally a deacidifying agent for stabilization contains chemical or biological aging processes. Method of stabilizing organic material according to claim 6, characterized in that the deacidifying agent-containing solution of Firming agent further additives for stabilization against chemical or biological aging processes. Use of a consolidant for preservation and restoration of papers, wood, textiles, paints and inks, and for fixation of soluble Inks in front of an aqueous Treatment, characterized in that the consolidating agent at least a silylated derivative of hydroxyl and / or carboxy and / or Amino-containing compounds comprising polysaccharides, Carbohydrates and their derivatives, cellulose and cellulose derivatives, Strength and starch derivatives, Hemicellulose and hemicellulose derivatives, galactomannans and galactomannan derivatives, Guar and guar derivatives, chitin and chitin derivatives, chitosan and chitosan derivatives, Dextrans and dextran derivatives, dextrins and dextrin derivatives, xanthans and xanthan derivatives, polyvinyl alcohol and polyvinyl alcohol derivatives, partially hydrolyzed polyvinyl acetate, gelatin and gelatin derivatives or polyethyleneamines and their derivatives, in a non-polar solvent contains.