DE2328526A1 - Pva (polysaccharide) liq microgel - stable longer dwell time when used for paper sizing - Google Patents

Abstract

Microgel comprises a stable fluid consisting of water and 0.05-10% (w.r.t. to total liq) of partially crosslinked PVA or a partially crosslinked mixt. of PVA and polysaccharide (I) crosslinked by Ti-ions. The microgel contains 0.05-9.95 wt.% (I) + PVA and starch 0.05-9.95% or Na-CMC 0.05-3%. The microgel is derived from a PVA having a Hoppler visc. 4-150 cP and contg. at >=50 mole % VA units. The water + PVA (or PVA + (I)) have a Brookfield visc. 1.15-2000 cP, of visc. >=15% than that of the aq. PVA (+(I)) from which the microgel is derived.

Description

Polyvinyl alcohol-containing microgel and its manufacture and use The invention relates to nikrogels containing polyvinyl alcohol or polyvinyl alcohol polysaccharide included, and a process for the preparation of such nicrogels.

As surface adhesives for paper and cardboard, certain materials are such as starch, sodium carboxymethyl cellulose, sodium alginate and polyvinyl alcohol with or used without the addition of clay. Under "surface glue" is a material to understand that is applied to the surface of paper or cardboard and thereby forms a barrier which allows ink and ink to be drawn in and absorbed prevents or inhibits other flowable substances in the paper or cardboard. Surface glues are to be distinguished from interior glue that during of the process of sheet formation.

Although the cost of polyvinyl alcohol is considered by weight Many times that of starch, it has been shown that polyvinyl alcohol as surface glue for paper or cardboard on the basis of use of the same high cost as well as, or in many cases better, than strength can behave. On the In most areas of application, however, the improvement in behavior is not sufficient been to move previous starch users to switch to polyvinyl alcohol. At present, polyvinyl alcohol is only used in special areas as opposed to starch preferred where quality is paramount.

The rapid penetration of polyvinyl alcohol solutions into paper and cardboard is evident. It is believed that even better behavior Polyvinyl alcohol would show if its "lingering" properties were improved could, d. H. when there is penetration of polyvinyl alcohol glue solutions into paper and significantly reduce or eliminate cardboard.

It is known that polyvinyl alcohol, by adding various gelling agents, such as Congo Red, Direct Orange 8 (Color-Index 22120), Direct Green 12 (Color-Index 30290), borax and various compounds of aluminum, chromium, copper, iron, Titanium, vanadium and zirconium, can be gelled. In U.S. Patents 2,720,468; 3,318,856 and 3,492,250 is the usage.

various titanium-organic complexes for gelling polyvinyl alcohol described. Since these gels are soft to stiff solids, they are as Surface glue for paper or warp size not suitable for textile purposes.

More recently, there is a two-step glue technique. known, which the reaction between polyvinyl alcohol and Borax for steering the penetration of the glue solution into paper or cardboard. In this process the paper or cardboard is first pretreated with a borax solution, whereupon the polyvinyl alcohol glue solution is applied. At borax X concentrations of over 2% by weight, based on the polyvinyl alcohol, occurs on the leaf surface Crosslinking reaction leading to the formation of a stiff gel, whereby an excessive Penetration of the polyvinyl alcohol is prevented. Let go of this process The cost of polyvinyl alcohol sizing is going down, but the process has grown not introduced any further, as it is an additional step in the gluing process brings.

About the use of mixtures of starch and polyvinyl alcohol as Surface glue is carried out with the aim of one or the other investigation been making ways to improve the quality of strength without being disproportionate standing cost increase or to reduce the cost of polyvinyl alcohol use without researching any deterioration in quality that is related to the Niss relationship. In these attempts but has the general intolerance of aqueous mixtures of starch and polyvinyl alcohol as. Proved an obstacle.

It has now been found that a new form of aqueous polyvinyl alcohol, hereinafter referred to as a polyvinyl alcohol microgel, or a polyvinyl alcohol polysaccharide microgel is advantageous, especially when surface sizing paper.

The polyvinyl alcohol or polyvinyl alcohol polysaccharide microgel is characterized by the fact that it is a constant fluid that of water and, based on the total fluid, about 0.05 to 10% by weight of partially crosslinked Polyvinyl alcohol or partially cross-linked mixture of polyvinyl alcohol and polysaccharide, which is or which is crosslinked with tetravalent titanium ions is formed, wherein in the Mixture of the polyvinyl alcohol is present in an amount of 0.05 to 9.95% by weight and the polysaccharide in an amount from 0.05 to 9.95 wt. 0 is present and from 0.05 to 9.95% by weight of starch or

0.05 to 3% by weight of sodium carboxymethyl cellulose, where the Microgel is derived from polyvinyl alcohol, which has a Hoeppler viscosity of about 4 to 150 cP has approximately 50 Mo196 of the monomer units in vinyl alcohol units are, and wherein the water and the partially crosslinked polyvinyl alcohol or the partially cross-linked mixture of polyvinyl alcohol and polysaccharide with a Brookfield viscosity from about 1.15 to 2000 cP and viscosity at least about 15% higher than that of the aqueous polyvinyl alcohol or the aqueous polyvinyl alcohol-polysaccharide mixture from which the microgel originates.

The microgels can be prepared by adding a) water, b) 0.05 to 10% by weight, based on the total fluid, of polyvinyl alcohol or a mixture of polyvinyl alcohol and polysaccharide, the polyvinyl alcohol in the mixture in an amount of 0.05 to 9.95% by weight is present and the polysaccharide is present in an amount of 0.05 to 9.95% by weight and represents 0.05 to 9.95% by weight starch or 0.05 to 3% by weight water carboxymethyl cellulose and wherein the microgel is derived from polyvinyl alcohol which has a Höppler viscosity of 4 to 150 cP and whose monomer units are at least about 50 mol% vinyl alcohol units, and c) titanium complex in the form of 1. salts of chelating organic acids with 2 to 10 carbon atoms , 2. water-soluble fluotitanium elements, 3. complexes with ß-diketones of the formula where R is hydrogen, lower molar alkyl or aryl and Y and Y 'are aryl, cycloalkyl or lower molar alkyl, or 4. Complexes with tri- (hydroxyalkyl) amines in which the alkyl groups contain 1 to 6 carbon atoms, in An amount sufficient to give 0.05 to 10 parts by weight of tetravalent titanium ion per 100 parts of polyvinyl alcohol, mixed and the titanium complex converted into tetravalent titanium ion and thereby a polyvinyl alcohol or polyvinyl alcohol polysaccharide nicrogel with a Brookfield viscosity of 1.15 to 2000 cP forms, the viscosity being at least 15% higher than that of the aqueous solution of polyvinyl alcohol or polyvinyl alcohol-polysaccharide mixture from which the microgel is derived.

In the drawing, Fig. 1 shows the effect of starch on viscosity of a polyvinyl alcohol starch microgel at various concentrations tetravalent Titanion and Fig. 2 the effect of Nstriumcarboxymethylcellulose on the viscosity a polyvinyl alcohol-sodium carboxymethyl cellulose microgel in various Concentrations of tetravalent titanium ion.

The microgels according to the invention are stable fluids, the water and partially crosslinked polyvinyl alcohol or a mixture of polyvinyl alcohol and polysaccharide.

Without limiting the invention to any theory, it is believed that the microgels according to the invention entanglements or entanglements of chains partially crosslinked polyvinyl alcohol or partially crosslinked mixture of polyvinyl alcohol and polysaccharide, which are colloidal-like dispersed in water Possess properties.

The microgels have properties that distinguish them from non-networked Polyvinyl alcohol, from gelled or substantially crosslinked polyvinyl alcohol or from mixtures of starch and polyvinyl alcohol. These microgels contain polyvinyl alcohol or a mixture of polyvinyl alcohol and polysaccharide with a crosslinking that increases the viscosity of the aqueous polyvinyl alcohol solution or aqueous mixture from which they are obtained is sufficient by at least about 15%, but not sufficient to increase the viscosity to over about 2000 cP. The term As used herein, "partial crosslinking" refers to this intermediate amount or range of crosslinking.

The microgels differ from the intermediate, the more aqueous Polyvinyl alcohol passes through to the solid during gelation, in that they are not are in a transition state, but represent stable fluids. Under "Resistant" here is a product to be understood that for a period of at least Viscosity stable for two days and resistant to precipitation or delamination is. This stability period is sufficient to allow the use of freshly set microgels to allow for purposes of gluing, sizing or finishing.

: The microgels have the peculiar property of being fluid while when applied to the surface of paper or cardboard, they are superior Show lingering properties.

In other words, these microgels wet absorbent paper (i.e. b. show a low surface tension with a small contact angle), but do not penetrate easily into it.

The term "polyvinyl alcohol" refers to the product made by complete or partial replacement of the acyl groups of a polyvinyl ester by Hydroxyl groups is obtained. To familiar methods of making polyvinyl alcohol include the hydrolysis, alcoholysis or saponification of a polyvinyl ester. to such polyvinyl esters include polyvinyl formate, acetate, propionate and butyrate. The preferred polyvinyl ester is polyvinyl acetate.

The polyvinyl alcohol for the purposes of the invention can be homo- or Be mixed polymer. When the polyvinyl alcohol is based on a polyvinyl ester homopolymer declines, it is generally referred to independently as a polyvinyl alcohol homopolymer, whether it is partially or fully hydrolyzed, d. IL. whether only part of the or all acyl groups in the original polyvinyl ester replaced with hydroxyl groups are.

If the polyvinyl alcohol is a polyvinyl ester copolymer it is commonly referred to as a polyvinyl alcohol copolymer. The term "mixed polymers" as used here includes polymers, derived from two or more copolymerizable monomers, e.g. B. Bipolymers Terpolymers etc. The Polyvinylalkoholmi schpolyme re can be completely or partially hydrolyzed, d. H. the hydrolyzable acyl groups in the original Copolymers can be completely or only partially replaced by hydroxyl groups be.

In any case, at least about 50 mol% of the monomer units should be used in the resulting polyvinyl alcohol, be it a homo- or a copolymers, vinyl alcohol units For polyvinyl alcohol homopolymers, it means that the polyvinyl alcohol should be hydrolyzed to at least about 50 mol%.

When less than about 50 mol% of the monomer units are present in the case of polyvinyl alcohol in the form of vinyl alcohol units can occur that the polyvinyl alcohol is no longer sufficiently water-soluble or hydroxyl-functional, to be suitable for the formation of a microgel according to the invention. Preferably are at least about 85 mol%, more preferably at least about 93 Mol% of the monomer units in the polyvinyl alcohol, vinyl alcohol units.

Any ethylenically unsaturated polymer can be used to produce polyvinyl alcohol mixed polymers Find monomers use that copolymerizes with vinyl acetate. Too typical Monomers include a, ß-unsaturated, aliphatic hydrocarbons, such as ethylene, Propylene, butylene, isobutylene, hexene, dodecene, octadecene and the like, unsaturated low aliphatic mcao and dicarboxylic acids, such as acrylic, methacrylic and maleic acid, Maleic anhydride, fumaric acid, itaconic acid and the like, lower molar alkyl esters unsaturated lower aliphatic mono- and dicarboxylic acids? like the methyl, ethyl, Propyl, isopropyl, butyl, isobutyl and tert-butyl esters of acids such as acrylic, Methacrylic, maleic, fumaric and itaconic acids and the like. Vinyl ester saturated, aliphatic acids, such as vinyl formate, vinyl propionate, vinyl butyrate, vinyl pivalate, Vinyl versatate and the like, vinyl low molar alkyl ethers, such as methyl vinyl ether, Ethyl vinyl ether, tert. Butyl vinyl ether and the like, unsaturated, aliphatic Amides such as acrylamide, methacrylamide, dimethylacrylamide and the like Amino-lower molar alkyl esters of unsaturated, lower aliphatic acids, such as Dimethylaminoethyl acrylate and methacrylate, diethylaminoethyl acrylate and methacrylate, Diisopropylaminoethyl acrylate and methacrylate and the like, and unsaturated, aliphatic amines, such as vinylamine, obtained by copolymerizing with vinyl succinic acid imide and treating with strong caustic alkali, and the like.

The molecular weight of the polyvinyl alcohol is intended to form a Höppler viscosity of about 4 to 150 cP.

The Höppler viscosity values mentioned here are based on a 4%, aqueous solution at 200 G by the falling ball method using a viscometer determined according to Höppler. This mode of operation is in the Hoeppler Precision Viscometer Fish-Schurman Corp. Operating Manual described.

When the molecular weight of the polyvinyl alcohol has a viscosity of below about 4 cP are uneconomical to bring about the formation of Nikrogel large amounts of crosslinker required. When the molecular weight of polyvinyl alcohol a viscosity of over about 150 cP is the formation of the microgel difficult to control because of the formation of substantial amounts of solid gel. Preferably the molecular weight corresponds to a Höppler viscosity of about 10 to 70 cP.

The polyvinyl alcohols which have a Höppler viscosity are preferred from about 20 to 40 cP and at least about 93 mol /% of the monomer units Are vinyl alcohol units. A class of particularly preferred polyvinyl alcohols form homopolymers with a degree of hydrolysis of at least about 99 mol%. Another particularly preferred class of polyvinyl alcohols are copolymers which about 94 to 98% by weight of vinyl acetate and about 2 to 6% by weight of methyl methacrylate derive and have a degree of hydrolysis of at least about 99 mol%.

To polysaccharides suitable in combination with the polyvinyl alcohol include starches and sodium carboxymethyl cellulose.

The term "starch" as used herein includes all natural starches of any kind and their derivatives.

The starches include corn starch, potato starch, amylose starch, Starch of the "Pearl" variety, bydroxyethylated starches, oxidized starches, carboxymethylated Starches, oxidized carboxymethylated starches and the like. The degree of polymerization of sodium carboxymethyl cellulose is determined by taking the Brookfield viscosity an aqueous solution according to ASTM test method D-1439-65.

The microgels according to the invention are obtained from water and on the total fluid, 0.05 to 10% by weight of polyvinyl alcohol, which is partially crosslinked is, or partially cross-linked mixture in the form of about 0.05 to 9.95% by weight of polyvinyl alcohol and about 0.05 to 9.95% by weight of polysaccharide which is about 0.05 to 9.95% by weight of starch and about 0.05 to 3% by weight of sodium carboxymethyl cellulose can be.

If the microgel has no components other than water and partial cross-linked polyvinyl alcohol or mixture of polyvinyl alcohol and polysaccharide contains, the water content of the microgel is about 90 to 99.95 wt.% o The microgels are under in this concentration range for a variety of purposes Achieve satisfactory results easily on portable. Preferably contains the microgel about 1 to 8 ° h of partially crosslinked polyvinyl alcohol or partially crosslinked mixture of polyvinyl alcohol and polysaccharide, with a range of about 2 to 6 06 is particularly preferred.

The microgels have Brookfield viscosities from about 1.15 to 2000 cP. This viscosity, i.e. H. the viscosity of the water and the partially crosslinked Polyvinyl alcohol or the partially crosslinked mixture of polyvinyl alcohol and Polysaccharide, should be at least about 15% higher than the viscosity of the aqueous Be polyvinyl alcohol solution or aqueous polyvinyl alcohol-polysaccharide mixture, from which the microgel originates. To determine the percentage of viscosity increase one measures the Brookfield viscosity of the aqueous polyvinyl alcohol or the aqueous Polyvinyl alcohol-polysaccharide mixture at the same temperature and concentration before and after his or

their partial crosslinking to form the microgel. Preferably the microgel has a Brookfield viscosity of about 25 to 1000 cP, especially about 35 to 500 ePO The Brookfield viscosity values mentioned here are at 25 C using a Brookfield viscometer, model RYTt at 100 rpm. determined (as in the corresponding font of the Brookfield Engineering Laboratories, Inc.).

The microgels can also contain other ingredients through which they become particularly suitable for special purposes. If z. B. the microgel for If the paper or cardboard glue is to be used, it may be useful to give him a finely divided filler, such as clay or calcium carbonate, or a pigment, such as titanium dioxide, to incorporate.

The microgel is produced by partially crosslinking polyvinyl alcohol or a mixture of polyvinyl alcohol and polysaccharide using tetravalent ones Titanium ions as crosslinkers. Suitable sources for these ions are titanium complexes, the can be added as such or formed in situ during the process. A class of these Complex includes titanium salts of chelating organic acids having 2 to 10 carbon atoms. Such organic acids include oxalic, apple, itaconic, milk, Wenn, lemon and salicylic acid. Such salts can also be formed in situ, e.g. B.

by reacting a tetraalkyl titanate, such as tetraisopropyl titanate, with the acid. As has been shown, one can help dissolve with a little alcohol support this salt.

In some cases, water-soluble fluotitanates, such as sodium fluotitanate, can be used and potassium fluotitanate.

Another class of these titanium complexes includes titanium complexes with β-diketones of the formula wherein R is hydrogen, lower molar O-alkyl or aryl and r and Y 'are aryl, cycloalkyl or lower molar alkyl. Typical ß-diketones of this structure include 2,4-pentanedione, 2,4-hexanedione, 2,4-heptanedione, 5-methyl-2,4-hexanedione, 2,4-octanedione, 5,5-dimethyl-2, 4-hexadione, 3-ethyl-2,4-pentanedione, 2,4-decanedione, 2,2-dimethyl-3,5-nonanedione, 5-methyl-2,4-pentanedione, 2,4-triedecanedione, 1- Cyclohexyl-1,3-butadione, 5,5-dimethyl-1,3-cyclohexanedione, 1,3-cyclohexanedione, 1-phenyl-1,3-butadione, 1- (4-biphenyl) -1,3-butadione, 1-phenyl-1,3-pentanedione, 3-benzyl-2,4-pentanedione, 1-phenyl-5X5 dimethyl-2,4-hexanedione, 1-phenyl-2-butyl-1,3-butadione and dibenzoylmethane. The preferred β-diketone is 2,4-pentanedione, which forms a complex with titanium to form titanium acetylacetonate.

Another class of titanium complexes includes titanium complexes with tri- (hydroxylalkyl) amines, in which the alkyl groups contain 2 to 6 carbon atoms. Typical examples are triethanolamine, tripropanolamine, triisopropanolamine, tributanolamine, trihexanolamine, Misohhydroxylalkylamine and mixtures thereof.

In the preparation of the polyvinyl alcohol microgels according to the invention a) water is mixed, b) 0.05 to 10% by weight, based on the total fluid, of polyvinyl alcohol or mixture of polyvinyl alcohol and polysaccharide and c) titanium complex in one sufficient amount to 0.05 to 10 parts by weight of tetravalent titanium ion to 100 parts To give polyvinyl alcohol or a mixture of polyvinyl alcohol and polysaccharide.

The titanium complex reacts with the dissolved polyvinyl alcohol or the dissolved polyvinyl alcohol-polysaccharide mixture, which formed the microgel will.

In some cases the pH must be adjusted before the Titanium complex with polyvinyl alcohol or a polyvinyl alcohol-polysaccharide mixture reacted. For example, when using of titanium salts of carboxylic acids, such as potassium titanosalate or titanium citrate, the pH to about 6 to 10 and preferably about 7 to 9 can be set. To water-soluble alkaline substances for the pH control includes the hydroxides and orthosilicates of alkali metals, such as lithium, Sodium and potassium, ammonium hydroxide and the hydroxides of alkaline earth metals, such as calcium, strontrium and barium. Sodium and ammonium hydroxide are preferred.

In the case of titanium lactate, pH control is necessary for microgel formation not necessary, although pH control can also be used more effectively of the Titanion.

Titanium complexes react with 13-diketones, such as xitane acetylacetonate also directly without pH adjustment with the polyvinyl alcohol or the polyvinyl alcohol-polysaccharide mixture for microgel formation. The dissolution of titanium acetylacetonate can be achieved by present support a small amount of alcohol.

For the partial crosslinking of the polyvinyl alcohol or the polyvinyl alcohol-polysaccharide mixture used, specific amount of tetravalent titanium ion within the above range depends on factors such as the concentration of polyvinyl alcohol or the polyvinyl alcohol-polysaccharide mixture, the molecular weight of the polyvinyl alcohol, the specific one that may be present Polysaccharide, the desired final viscosity, etc.

away. The crowd should be directed in such a way that you can mix a microgel with a Maintains Brookfield viscosity of about 15 to 2000 cP.

In most cases, about 0.2 to 2 parts by weight will be tetravalent Titanion to 100 parts of polyvinyl alcohol or polyvinyl alcohol-polysaccharide mixture insert.

Since the microgels according to the invention have a high proportion of water included, their transport over long distances would be economically uneconomical. In addition, the microgels should only be produced a short time before use be as it is yours of persistence over a period of several Days can be missing. These microgels are therefore preferably commercially available Have a delivery form of a dry mix of microgel precursor ingredients. These The way of working has the advantages of lower transport costs, a more uniform one Quality of the product and maximum ease of microgel formation. E.g. one can a dry mix of polyvinyl alcohol alone to form the landel product or with polysacoharide and an appropriate, solid titanium complex, such as Manufacture titanium citrate, titanium lactate or potassium titanium oxalate.

A preferred precursor mixture contains polyvinyl alcohol, polysaccharide, and titanium citrate or else polyvinyl alcohol and titanium citrate. When the use is made dissolve the mixture in water and add enough base, such as ammonium hydroxide, to adjust the pH to 9-10, thereby forming the microgel.

Another technique for making a microgel precursor urine mixture becomes finely divided, dry polyvinyl alcohol or finely divided, dry mixture of polyvinyl alcohol and polysaccharide with an appropriate amount of one Sprayed solution that contains a titanium complex.

For example, a solution which is a mixture can be used for this purpose of ethyl alcohol, lactic acid and tetraisopropyl titanate. The sprayed one Solution is made of the polyvinyl alcohol powder or polyvinyl alcohol polysaccharide powder, which remains essentially dry is adsorbed. If the mission is to take place, this product is dissolved in water with heating. Apparently the ingredients are reacting initially to the formation of titanium lactate, whereupon the microgel forms directly, without that a pH adjustment is required.

As explained in Fig. 1 and 2, the gel is used to form a micro required amount of tetravalent given viscosity Titanion through the presence of starch or sodium carboxy methyl cellulose in the polyvinyl alcohol solution substantially reduced. In Fig. 1, the amount of tetravalent added is sufficient Titanion does not affect the viscosity of the 1%, polyvinyl alcohol or the 5% Strength on its own to increase significantly while under significant influence on the mixture of polyvinyl alcohol and starch. In Fig. 2 is the action of the tetravalent titanium ion to the viscosity of the mixture of 3% polyvinyl alcohol and 0.2% sodium carboxymethyl cellulose much stronger than the 3.2% polyvinyl alcohol or the 0, igen sodium carboxymethyl cellulose alone. When sodium carboxymethyl cellulose is reacted with tetravalent titanium ions alone, the viscosity begins to increase, but as the reaction proceeds, a precipitate is formed.

The microgels are particularly suitable as glue for paper and cardboard (as well as cardboard), for coverings, as dextile warp sizes and in adhesives. the Application techniques for these purposes are familiar to the person skilled in the art. Used in any case the microgels in a similar way to the use of polyvinyl alcohol solutions was made with the change that when using the microgels with lower Polymer concentrations than polyvinyl alcohol solutions can work. When gluing of printing paper are the water and oil absorption properties of polyvinyl alcohol In many cases, microgel-coated paper or cardboard surfaces roughly match those the same underlay equivalent to that with polyvinyl alcohol solution of twice the amount Econcentration was coated. The polyvinyl alcohol ~ polysaccharide microgels according to of the invention are particularly suitable for gluing to be used for printing purposes Paper. The print quality of such sized paper is that of the same superior to paper sized with the polyvinyl alcohol microgel.

The following examples serve to further illustrate the invention. Parts and percentages relate to weight. The one for the Höppler viscosity The values given for the various polyvinyl alcohols relate to a 4% Solution at 200 a.

Example 1 This example illustrates the preparation of microgel by adding acid to polyvinyl alcohol, which by crosslinking with tetravalent Titanion has been gelled. It became a dry mix of 62.5 g of polyvinyl alcohol with a degree of hydrolysis of 99.5% and a Höppler viscosity of 30 cP and 2.5 g potassium titanium oxalate (K2Ti (OH) 2 (C2O4) 2 # H2O) added to 2500 ml water and heated, until the solids were dissolved and the solution cooled to room temperature and mixed with about 10 ml-10% sodium hydroxide solution, whereupon a thick gel network forms (Viscosity over 2000 cP).

When acetic acid was added, the gel network broke with the occurrence of one stable, fluid, viscous material with a Brookfield viscosity of 60 cP, which did not show any slight indentation on absorbent paper.

EXAMPLE 2 This example illustrates the production of microgel by adding acid to gelled polyvinyl alcohol with subsequent heating. A mixture containing 1014 ml of water, 2.93 g of NaCl and 428 ml on a 6% aqueous solution of polyvinyl alcohol (degree of hydrolysis 99.5 o, Höppler viscosity 60 cP) was heated to 90 to 1000 C and then cooled to 250 C, whereupon 2.65 g of titanium lactate were rinsed into 50 ml of water and 50 ml of water were added. To 10 min. Stirring, 8 ml of NH40H were stirred in and after 1 hour.

8.8 ml of acetic acid were added and stirred into the weak gel. 30 minutes later the gel structure was sufficiently weakened around a Allow stirring with a magnetic stirrer. The material was 1.5 hours at room temperature and then kept at 90 to 1000 C for a further hour. The slightly cloudy liquid had a viscosity of 61 to 71 cP. She moistened a towel, was from this but not sucked in.

Example 3 This example illustrates the preparation of microgel by adding acid to gelled polyvinyl alcohol followed by grinding. A 1014 ml of water, 2.93 g of NaCl and 428 ml of an own solution of the in Example 2 The polyvinyl alcohol-containing mixture described was heated to 90 to 1000.degree and then cooled to 250 C, whereupon 2.88 g of titanium lactate in 100 ml of water and 50 ml more water was added. After stirring for 10 min, NH4OH was added in an amount of 8 ml was added and stirring continued for 10 min. After 1 hour it was 8.8 ml of acetic acid added, which lowered the pH from 9.8 to 4.6 and thus decreased gel strength. The gel (1500 ml) has now been filled with 1000 g of 4 mm glass beads for 21 hours ground. The slightly dreamy liquid was stable and had a viscosity of 15 cP at 250 C. It did not penetrate the towel paper.

EXAMPLE 4 A solid mixture of 12 g of that described in Example 1 Polyvinyl alcohol, 0.15 g titanium citrate and 0.2 g citric acid monohydrate was in Dissolve 250 ml of water on a steam bath and cool the solution down to 300 g total weight of solution brought at 250 ° C. This solution (pH 4.3, Brookfield viscosity 59 cP) 1 ml of NH4OH were added. The resulting microgel was clear and had a pH of 9.6 and a Brookfield viscosity of -100 cP.

A # 16 Meyer rod was used to make the above polyvinyl alcohol microgel Cardboard of 0.41 mm thickness (16 points) glued and the glued cardboard then in one Oven dried for 25 seconds at 1200 C. A drop fell on the dried cardboard Abandoned water; complete penetration of the drop requires 47 min.

This procedure was repeated four days later. The polyvinyl alcohol microgel had a Rrookfield viscosity of 90 cP at this point. One on the glued Carton of dropped water droplets required 45 minutes for complete penetration.

Another four days later the polyvinyl alcohol microgel had a Brookfield viscosity from 83 cP. A cardboard box glued with this microgel according to the above method dropped water droplets penetrated completely in 26 minutes.

For comparison, the same carton was made using a Meyer rod No. 16 with a 6% solution of the same medium molecular weight polyvinyl alcohol glued that had not been converted into a Nikrogel. Choosing a show Polyvinyl alcohol solution for this comparison was found to have a Brookfield viscosity of 106 cP, which was largely the same as the viscosity of the 4% microgel above 100 cP. A drop of water placed on the glued and dried cardboard penetrated in 22 min.

completely one.

For further comparison, a drop of water was placed on the same, unsized one Abandoned cardboard box. It only took 50 seconds for complete penetration.

3 e i 5 p 1 e 1 5 12 g nischpolymeres with a content of 96% Vinyl alcohol and 4% of methyl methacrylate (Höppler viscosity 30 cP, degree of hydrolysis 99%) were with 0.21 g citric acid monohydrate and 0.15 g titanium citrate mixed. The mixture was then dissolved in approximately 250 g of hot water and the The resulting solution is cooled and treated with water to a total solution weight of 300 g brought at 250 a. This solution had a pH of 4.1 and a Brookfield viscosity from 56 cP. 4 ml reagent grade ammonium hydroxide was added with stirring. That The resulting microgel was crystal clear and had a Brookfield viscosity of 120 cP.

For example, 6 10 g of interpolymer of medium molecular weight made of polyvinyl alcohol and vinyl versatate, CH3O CH3 - o - C - OCH "CH2, which becomes 96% derived from polyvinyl alcohol (CH2) 5CH3 and 4 O6 derived from vinyl versatate mixed with 0.12 g of titanium citrate and 0.20 g of citric acid monohydrate. The mixture was dissolved in hot water and with water to a total solution weight of 300 g brought at 250 C. The solution had a Brookfield viscosity of 48 cP and a pH of 3.3. An addition of 3 ml of ammonium hydroxide resulted in formation a clear, flowable mass with a viscosity of 88 cP and a pH value of 9.8.

EXAMPLE 7 100 g of 4% strength aqueous solution of the solution described in Example 1 Polyvinyl alcohol was made with a sufficient amount of a mixture of equal parts Ethyl alcohol, lactic acid and tetraisopropyl titanate are added to ensure a stable, to form fluid microgel with a Brookfield viscosity of 100 cP, which then was diluted to 4000 g with water. The accruing, flowable Mass was placed on a 5.1 cm deep sample of coal grit (obtained from Champion Pond of Consolidation Ooal Co.

Pittsburgh, Pa.) At 6,000 gallons / acre (5.6 l / m2) sprayed on. After four days of drying, this sample became a stabilized surface tested for durability by covering the sample with water and letting it dry and then covered again with water and allowed to dry again and then 3 dm was placed under a tap, the water output of which took place at 1.05 kg / cm2. It took 20 minutes to wash the water through the 5.1 cm sample.

A sample of the charcoal grit was used for comparison Sprinkled with the same weight of unreacted polyvinyl alcohol and had been treated.

This sample withstood the water jet for only 1.5 minutes.

A non-injected sample of the gohlegruses was used for further comparison tested in the same way, this sample withstood the water jet for only 0.2 minutes.

B e i 8 »i e 18 42 g of 10% strength aqueous solution of the solution described in Example 1 Polyvinyl alcohol was added to 58 g of water. The resulting solution (Brookfield viscosity 45 cP, pH 6.0) was with a solution of 0.2 g of tetraisopropyl titanate in 0.2 g lactic acid and 2 g methyl alcohol are added. A stable, viscous, flowable one fell Mass with a Brookfield viscosity of 185 cP and a pH of 3.3 to the absorbent paper wetted, but not penetrated this.

EXAMPLE 9 For comparison, the following three samples were prepared: a) 3.5%, aqueous polyvinyl alcohol microgel with a Brookfield viscosity of 86 cP, obtained using the polyvinyl alcohol and according to the procedure from example 8.

b) 3%, aqueous polyvinyl alcohol solution, which is used for production the microgels of (a) used contained polyvinyl alcohol and a Brookfield viscosity of 38 cP.

c) 9% aqueous starch solution containing hydroxylated starch (Brookfield viscosity 46 cP).

With these three samples, round sieve cardboard 0.43 mm thick (17 Point) on a test size press of the Beleit type, with the pressure on Gap of the applicator roller was kept at 1.05 and 2.10 kg / cm² and the cardboard the machine at a constant speed of 91.4 / min.

went through.

At the end of the sizing tests, the cardboard boxes were surface-sized to determine their printability according to the TAPPI Routine Control Method 278 described Vanceometer test, in which the speed is measured, with which a sample of silicone oil with a viscosity of 32.6 cP penetrates the box. In performing this test, the sample was placed on a slightly inclined plane clamped, which was hung like a hinge in such a way that it became a light screen could be lifted out. After clamping on the inclined plane were on The sample is given a few drops of the oil, whereupon a steel roller moves the plane down was allowed to roll down and thereby smeared the oil drop so that the oil smear when lifting the inclined plane covered the light screen. To measure the speed the oil absorption one observes the speed with which the display reflected the Light that comes in at an angle of 700, goes back.

A drop of water was used to test the water resistance of each carton Placed on the surface-sized cardboard and the time recorded within which the drop disappeared. The following table names the values obtained.

T a b e l l e I Coating pressure on the roller - Oil resistance - Gauge display, Water absorption, solution gap, kg / cm² microampere, at the following sec.

Time (sec) 0 20 40 60 90 3.5% microgel 2.10 96 96 96 95 94 390 1.05 93 93 92 91 89 435 3% polyvinyl alcohol 2.10 84 76 65 55 44 105 1.05 74 68 58 51 43 100 9% starch 2.10 84 80 74 68 60 60 1.05 93 91 87 82 75 85 Untreated Cardboard material - 56 38 35 34 34 45 B e i 5 D i e 1 10 12 g des Fine-particle, solid polyvinyl alcohol described in Example 1 were mixed with 2 g of a mixture of 1 part ethyl alcohol, 1 part 85% of the lactic acid and 1 part tetraisopropyl titanate splattered. The coated polyvinyl alcohol was then added to 288 grams of water on a Added steam bath and stirred until dissolved, whereupon the solution cooled and was brought to a total weight of 300 g at 250 ° C. with water. The resulting, The flowable microgel was clear and had a Brookfield viscosity of 92 cP.

For comparison, 12 g of the same solid polyvinyl alcohol as above, but in uncoated form, with 250 g of water on a steam bath up stirred to dissolve, whereupon the solution was cooled and washed with water to a total weight of 300 g at 250 ° C was brought. The resulting solution had a Brookfield viscosity from 56 cP.

B e i 8 O i e 1 11 37.9 1 of an aqueous, 4% of that described in Example 1 Polyvinyl alcohol-containing solution was mixed with a sufficient amount equal parts of ethyl alcohol, lactic acid and tetraisopropyl titanate added to the Bring Brookfield viscosity to 100 cP. With the solution thus obtained was on a test size press of the Beloit type, which operates at 76.2 m / min. and a print was operated at the nip of 0.98 kg / cm², unbleached kraft cardboard was sized. A coating weight of 20 g / kg cardboard was sufficient to achieve a smooth surface and fill most of the pinholes.

3 e i 5 i e 1 12 425 ml of a 6% aqueous solution of the in example 1 described polyvinyl alcohol was added to 1000 ml of water. This solution was stirred with 100 ml of a 3% aqueous solution of potassium titanium oxalate added, which lowered the pH to 4.6. In this solution (Brookfieid viscosity 28 cP) ammonium hydroxide was stirred in sufficient amount to bring the pH up to 6.8 to bring with a constant, 1.7% microgel with a Brookfield viscosity of 42 cP. When this flowable mass drips out onto absorbent towel paper It took 109 seconds for a drop to penetrate the towel material.

For comparison, using the same polyvinyl alcohol, but without microgel formation, polyvinyl alcohol solutions of various concentrations set, each of which was dripped onto the absorbent towel paper. The penetration time of a drop was 2 seconds for the 1.0% solution, 4 seconds for the 2.0% solution, 12 Sec. At 3.0%, 23 sec.

for the 4.0%, 50 seconds for the 5.0% and 135 seconds for the 6.0%.

EXAMPLE 13 A dry mix of 25 parts of the in Example 1 and 0.5 part of potassium titanium oxalate became 1000 Parts of water are added and the mixture is heated to about 900 C for a sufficient time while stirring, to dissolve the solids. This solution (Brookfield viscosity 38 cP) was after Cooling with enough ammonium hydroxide added to bring the pH to 6.8, being a stable, flowable mass with a Brookfield viscosity of 48 cP accrued. When this mass dripped onto absorbent towel paper, the was Time to penetration of a drop 438 sec.

B e i 5 p i e 1 14 785 g of the polyvinyl alcohol described in Example 1 and 72.5 g of potassium titanium oxalate were mixed as a dry powder and made up to 37,500 g Add water and stir until the solids dissolve to 80 up 90 ° C heated, to prevent foaming during this dissolution 1.5 ml of a polyoxyalkylene derivative of propylene glycol ("Bluronic L-61") was added. The solution, cooled to 250 ° C. with stirring, was treated with sufficient ammonium hydroxide added to increase the Brookfield viscosity from about 28 to about 50 cP. the accruing, stable, flowable mass, the partially cross-linked polyvinyl alcohol at a concentration of 2.1 ° e, was used as a test size press Type Beloit applied to cardboard as surface glue, whereby the mass proved to be smoothly applicable without labor difficulties. The resulting cardboard was both in the water and the oil resistance one in the same way with one 3% aqueous polyvinyl alcohol solution is superior to glued cardboard.

Example 15 425 ml 6% aqueous solution of polyvinyl alcohol with a degree of hydrolysis of 88 0% and a Höppler viscosity of 40 cP in 1000 ml of water. The resulting solution was stirred with 100 ml 3% aqueous solution of potassium titanium oxalate added, which increases the pH 4.6 decreased. The resulting solution (Brookfield viscosity 28 cP) was with a sufficient Amount of ammonium hydroxide added to raise the pH of the solution to 6.2, The accruing, stable, flowable material (Brookfield viscosity 50 cP) wetted absorbent paper; but did not penetrate easily into this.

B e i s p i e l 16 97.5 g of water were mixed with a 10% aqueous Solution (52.5 g) of the polyvinyl alcohol described in Example 1 are added. the Resulting solution (Brookfield viscosity 44 cP, pH 5.8) was with a solution of 0.25 g titanium acetylacetonate in 0.06 g isopropyl alcohol and 2.1 g methyl alcohol offset. The resulting, flowable, permanent mass (Brookfield viscosity 104 cP, pH 6.0) wetted absorbent paper without penetrating into it.

EXAMPLE 17 The following four samples were used for comparison produced: a) 3.5% polyvinyl alcohol microgel with a pH of 8.0 and a Brookfield viscosity of 145 cP obtained with the polyvinyl alcohol and after the procedure of Example 16.

b) 2.75% polyvinyl alcohol microgel with a pH of 7.8 and a Brookfield viscosity of 65 cP, obtained with the polyvinyl alcohol and after the procedure of Example 16.

c) 3.0% solution of the used to produce the above microgels Polyvinyl alcohol with a pH of 6.0 and a Brookfield viscosity of 40 cP.

d) 9% strength with a Brookfield viscosity of 20 cP.

The four solutions were used on a test size press of the type Beloit "hard", internally glued cardboard glued, with the pressure at the gap of the applicator roller was maintained at 2.10 g kg / cm2 and the carton the constant speed machine from 91.4 m / min. went through.

Each of the glued cardboard boxes were made using the example 9 Vanceometer tests described above have been tested for oil resistance. The values obtained names the following table.

Table II Oil resistance coating solution. Device display, Microamps, at the following time (sec.) 0 30 60 90 120 150 180 210 240 270 300 3.5% microgel 100 100 100 100 100 99 99 98 98 97 97 2.75% microgel 99 97 94 92 88 85 81 78 73 70 65 3.0% polyvinyl 78 36 26 23 22 22 20 21 20 20 20 alcohol 9% strength 83 36 26 23 22 21 21 21 21 21 21 untreated cardboard 72 28 26 24 24 24 24 24 24 24 24 B e i s »i e 1 18 40 g of 10%, aqueous solution of the polyvinyl alcohol described in Example 1 to 60 g of water added.

The resulting solution (Brookfield viscosity 48 cP, pH 6.0) was mixed with 0.18 g of titanium triethanolamine in 1.8 g of methyl alcohol. The accruing, stable, viscous, flowable mass (Brookfield viscosity 128 cP, pH value 8.4) wetted absorbent paper without penetrating into this one.

B e i s T) i e 1 19 12 g of the polyvinyl alcohol described in Example 1 0.12 g of titanium citrate and 100 g of citric acid were added. This mixture was dissolved in hot water and with water to a total solution weight of 700 g Brought to 25 ° C (Brookfield viscosity 64 cP, pH 4.4).

The addition of 2 ml of 10% sodium hydroxide solution produced a clear, even, Flowable mass with a viscosity of 100 cP and a pH value of 11.

B e i 5 »i e 1 20 15 g of the polyvinyl alcohol described in Example 1 were dissolved in hot water and with water to a total solution weight of Brought 300 g at 250 C. This solution (Brookfield viscosity 71 cP) was with a A solution of 0.46 g of titanium acetylacetonate in 3.54 g of methyl alcohol was added. The accruing, Flowable mass was uniform and had a Brookfield viscosity of 870 cP.

Example 21 200 g of an aqueous solution (Brookfield viscosity 43 cP) with a content of 4.5% hydroxyethylated corn starch and 1 5 'of polyvinyl alcohol with a degree of hydrolysis of 99.5 5' and a Höppler viscosity of 30 cP were mixed with 1.4 g of a mixture of equal parts of ethyl alcohol and lactic acid and tetraisopropyl titanate added. The microgel formed by this addition had a Brookfield viscosity of 120 cP.

For comparison, 5.2 g of the same ethyl alcohol-lactic acid-tetraisopropyl titanate mixture were used to 200 g of an aqueous solution (Brookfield viscosity 30 cP) with a content of 5% of the same hydroxyethylated corn starch added. The resulting solution had a Brookfield viscosity of only 33 cP.

For further comparison, 3.7 g of the same ethyl alcohol-lactic acid-tetraisopropyl titanate mixture were used added to 200 g of an aqueous solution (Brookfield viscosity 16 cP), the 1 ° h of the same polyvinyl alcohol contained. The resulting solution had a Brookfield viscosity from only 22 cP.

Example 22 300 g aqueous solution (Brookfield viscosity 56 cP) with a content of 4% of oxidized corn starch and 2% of polyvinyl alcohol (Degree of hydrolysis 99.5%, Höppler viscosity 30 cP) were mixed with 3.5 g equal parts of ethyl alcohol, lactic acid and tetraisopropyl titanate are added.

The microgel formed by this addition had a Brookfield viscosity from 195 cP.

For comparison, 4 g of the same ethyl alcohol-lactic acid-tetraisopropyl titanate mixture were used added to 300 g of an aqueous solution containing 4% of the same oxidized corn starch and had a Brookfield viscosity of 28 cP. The resulting solution had a Brookfield viscosity of only 33 cP.

Example 23 300 g aqueous solution (Brookfield viscosity 94 cP) with a content of 8.0% of hydroxyethylated starch and 1.0% of polyvinyl alcohol (Degree of hydrolysis 99.0 5 ', Höppler viscosity 30 cP) were with a solution of 0.06 g titanium acetylacetonate in 0.02 g isopropyl alcohol and 0.72 g methyl alcohol are added. The resulting microgel was uniform and had a Brookfield viscosity of 136 cP.

For example, 1 24 37.85 1 aqueous solution with a content of 3.8 % of hydroxyethylated starch and 1.1% of polyvinyl alcohol (degree of hydrolysis 99.5 %, Höppler viscosity 30 cP) were the same with a sufficient amount of a mixture Parts of tetraisopropyl titanate, ethyl alcohol and lactic acid added to the Brookfield viscosity increase to 200 cP. The resulting microgel was used on an experimental size press of the Beloit type, which run at a constant speed of 76.2 m / min. operated and at which the pressure at the nip of the applicator roller is kept at 0.57 kg / cm2 was, paper (16.78 kg / US ream) glued on both sides. The coating weight was 0.77 kg / US ream. This paper was then printed on a stone offset printing press, whereby, as can be seen from the condition of the rubber blanket, during the passage of the paper through the press nip, there is essentially no plucking of paper fibers resulted, both when adding printing ink to the paper (wet plucking) as well as even when working without paint supply (dry picking).

For comparison, a sample of the same paper raw material is shown in the same conditions on both sides with a 3.4%, made from the same polyvinyl alcohol obtained polyvinyl alcohol microgel sized, the coating weight 1.13 kg / US ream. When printed, this sample showed a higher one Amount of dry pick than the above sized with polyvinyl alcohol starch microgel Sample.

Example 1 25 300 g aqueous solution (Brookfield viscosity 55 cP) with a content of 3% of polyvinyl alcohol (degree of hydrolysis 99.5%, Höppler viscosity 30 cP) and 0.2% of refined standard sodium carboxymethyl cellulose (Brookfild viscosity, determined on a 1% solution at 25% C, approximately 3250 cP), the average substituted with approximately 0.75 sodium carboxymethyl groups per anhydroglucose unit was, with 1 g of a mixture of equal parts of ethyl alcohol, lactic acid and tetraisopropyl titanate offset. The microgel formed by this addition provided a clear solution a Brookfield viscosity of 150 cP.

For comparison, 1 g of the same ethyl alcohol-lactic acid-tetraisopropyl titanate mixture was used added to 300 g of an aqueous solution containing 3.2% of the same polyvinyl alcohol and had a Brookfield viscosity of 40 cP. The resulting solution had a Brookfield viscosity of only 50 cP.

For further comparison, 1 g of the same ethyl alcohol-lactic acid-tetraispropyl titanate mixture was used added to 300 g of an aqueous solution containing 0.2% of the sodium carboxymethyl cellulose and had a Brookfield viscosity of 24 cP. The resulting solution had a Brookfield viscosity of 24 cP.

B e i 8 O i e 1 26 300 g aqueous solution (Brookfield viscosity 156 cP) with a content of 1.0% polyvinyl alcohol (degree of hydrolysis 99.5%, Höppler viscosity 30 cP), 2.0% sodium carboxymethyl cellulose and 3.0 /% of hydroxyethylated Starch were made with a solution of 0.24 g titanium acetylacetonate in 0.08 g isopropyl alcohol and 2.9 g of methyl alcohol are added. The polyvinyl alcohol microgel formed by this addition produced a uniform, flowable mass with a Bro * field viscosity of 286 cP.

E p i e 1 2? 300 g aqueous solution (Brookfield viscosity 122 oP) with a content of 3% of starch of the Pearl variety, 0.9% of polyvinyl alcohol (Degree of hydrolysis 99.5%, Höppler viscosity 30 cP) and 0.1 /% of that in Example 5 Sodium carboxymethyl cellulose described were the same with 07 of a mixture Parts of ethyl alcohol, lactic acid and tetraisopropyl titanate are added. The accruing Microgel had a Brookfield viscosity of 445 cP.

This microgel was made using a No. 15 Myer rod Round sibling cardboard, 0.41 mm thick, glued. A drop fell on the glued cardboard Abandoned water, which took 24 minutes to penetrate completely.

A drop of water applied to the unsized raw material for comparison penetrated into; 11 min. Completely on.

For comparison, 3 g of the same ethyl alcohol-lactic acid-tetraisopropyl titanate mixture were used to 300 g of an aqueous solution (Brookfield viscosity 108 cP) added the 3% of the same starch and 0.1% of the same sodium carboxy methyl cellulose The resulting solution had a Brookfield viscosity of only 110 OPe 3 g of the same mixture of ethyl alcohol, lactic acid and tetraisopropyl titanate were used as a comparison added to 300 g of an aqueous solution containing 3% of the same starch and had a Brookfield viscosity of 78 cP.

The Brookfield viscosity of the resulting solution was 77 cP.

Example 28 300 g aqueous solution with a content of 1 vol of high molecular weight polyvinyl alcohol (degree of hydrolysis 99%, Höppler viscosity 60 cP) and 4.5% hydroxyethylated corn starch (Brookfield viscosity 46 cP) with 1.2 g of a mixture of equal parts of ethyl alcohol, lactic acid and tetraisopropyl titanate offset. The microgel formed by this addition was a viscous solution with a Brookfield viscosity of 935 cP.

For comparison, 2.9 g of the ethyl alcohol-lactic acid-tetra-isopropyl titanate mixture were used added to 300 g of an aqueous solution containing 1% of the same polyvinyl alcohol and had a Brookfield viscosity of 20 cP. Had the resulting solution a Brookfield viscosity of only 44 cP.

EXAMPLE 29 300 g of an aqueous solution were made up, the 4.5% of a hydroxyethylated corn starch and 1 0% mixed polymer with a Content of 96 Vo of vinyl alcohol and 4 ° b of methyl methacrylate and a degree of hydrolysis of 99% and a Höppler viscosity of 30 cP contained the Brookfield viscosity the aqueous solution containing the corn starch and the mixed polymer was 41 cPQ This solution was made with 2.0 g of a mixture of equal parts of ethyl alcohol, lactic acid and tetraisopropyl titanate added. The microgel formed by this addition was a viscous solution with a Brookfield viscosity of 305 cP of the.

For comparison, 2.9 g of the ethyl alcohol-lactic acid-tetraisopropyl titanate mixture were used added to 300 g of an aqueous solution containing 1% of the same copolymer and had a Brookfield viscosity of 20 cP.

The resulting solution had a Brookfield viscosity of only 20 cP.

Claims (8)

P a t e n t a n s p r ü c h e Microgel, characterized in that it is a permanent fluid, that of water and, based on the total fluid, 0.05 to 10% by weight of partially crosslinked Polyvinyl alcohol or partially cross-linked mixture of polyvinyl alcohol and polysaccharide, which is or which is crosslinked with tetravalent titanium ions is formed, wherein in the Mixture of the polyvinyl alcohol is present in an amount of 0.05 to 9.95% by weight and the polysaccharide is present in an amount from 0.05 to 9.95% by weight and at 0.05 represents up to 9.95% by weight of starch or 0.05 to 3% by weight of sodium carboxymethyl cellulose, the microgel being derived from polyvinyl alcohol, which has a Höppler viscosity from about 4 to 150 cP and at least 50 mol / o of the monomer units Are vinyl alcohol units, and where the water and the polyvinyl alcohol or the partially cross-linked mixture of polyvinyl alcohol and polysaccharide with a Brookfield viscosity from 1.15 to 2000 cP - and have viscosity at least 15% higher than that of the aqueous polyvinyl alcohol or the aqueous polyvinyl alcohol-polysaccharide mixture from which the microgel originates. 2. Microgel according to claim 1, characterized in that there are 1 to 8% by weight of partially crosslinked polyvinyl alcohol or partially crosslinked mixture of polyvinyl alcohol and polysaccharide, the polyvinyl alcohol having a Höppler viscosity from 10 to 70 cps, at least 85 mole percent of the monomer units in the polyvinyl alcohol Are vinyl alcohol units and the microgel has a Brookfield viscosity of 25 to 1000 cP. 3. microgel according to claim 2, characterized in that there are 2 to 6% by weight of partially crosslinked polyvinyl alcohol or partially networked Contains mixture of polyvinyl alcohol and polysaccharide, the polyvinyl alcohol has a Höppler viscosity of 20 to 40 cP, at least 93 mol% of the monomer units in which polyvinyl alcohol are vinyl alcohol units and the microgel is a Brookfield viscosity from 30 to .500 cP. 4. microgel according to one or more of claims 1 to 3, characterized characterized in that the polyvinyl alcohol is a homopolymer with a degree of hydrolysis of at least 99 mole percent. 5. Microgel according to one or more of claims 1 to 3, characterized characterized in that the polyvinyl alcohol is a mixed polymer which becomes 94 up to 98% by weight of vinyl acetate and 2 to 6% by weight of methyl methacrylate and has a degree of hydrolysis of at least 99 mol%. 6. A process for the production of stable, flowable, polyvinyl alcohol-containing microgel according to one or more of claims p to 5, characterized in that a) water, b) 0.05 to 10% by weight, based on the total fluid, of polyvinyl alcohol or Mixture of polyvinyl alcohol and polysaccharide, the polyvinyl alcohol being present in the mixture in an amount of 0.05 to 9.95% by weight and the polysaccharide being present in an amount of 0.05 to 9995% by weight and 0.05 to 9% by weight , 95% by weight starch or 0.05 to 3% by weight sodium carboxymethyl cellulose and wherein the microgel is derived from polyvinyl alcohol which has a Höppler viscosity of 4 to 150 cP and whose monomer units are at least 50 mol% vinyl alcohol units, and c) Titanium complex in the form of 1. salts of chelating organic acids with 2 to 10 carbon atoms, 2. water-soluble fluotitanates, 3. complexes with ß-diketones of the formula where R is hydrogen, lower molar alkyl or aryl and Y and Y 'are aryl, cycloalkyl or lower molar alkyl, or 4. Complexes with tri- (hydroxylalkyl) amines in which the alkyl groups contain 1 to 6 carbon atoms are sufficient Amount to give 0.05 to 10 parts by weight of tetravalent titanium ion to 100 parts of polyvinyl alcohol, mixes and converts the titanium complex into tetravalent titanium ion and thereby forms a polyvinyl alcohol or polyvinyl alcohol-polysaccharide microgel with a Brookfield viscosity of 19n5 to 2000 oP, the The viscosity is at least 15% higher than that of the aqueous solution of polyvinyl alcohol or polyvinyl alcohol-polysaccharide mixture from which the microgel is derived. 7. The method according to claim 6, characterized in that as Titanium complex a titanium salt of a chelating organic acid with 2 to 6 Carbon atoms used in sufficient quantities to produce 092 to 2 parts by weight of tetravalent Titanium ion per 100 parts of polyvinyl alcohol or polyvinyl alcohol-polysaccharide mixture to surrender 8. The method according to claim 6, characterized in that, as a titanium complex Titanium citrate used. 9, use of the microgel according to one or more of the claims 1 to 5 for surface sizing of sheet material in the form of paper, cardboard and paperboard by applying to at least one surface of the material and allowing it to dry of the material. L e r s e i t e