MXPA00011232A - Paper made from aldehyde modified cellulose pulp. - Google Patents

Abstract

This invention relates to paper comprising aldehyde modified cellulose pulp prepared using nitroxyl radical mediated oxidation and further containing selected additives comprising aldehyde functional polymers or polymers containing functionality capable of reacting with aldehyde groups and having improved strength properties. This invention further relates to paper made from aldehyde modified cellulose pulp where an hydroxyl group containing polymer is added to the paper to provide wet strength properties.

Description

PAPER MADE OF CELLULOSE PULP MODIFIED WITH ALDEHYDE WITH SELECTED ADDITIVES DESCRIPTION OF THE INVENTION The invention relates to paper comprising cellulose pulp modified with aldehyde or fiber prepared using defined oxidation conditions and which also contain selected additives to provide paper products with properties of significantly improved moisture resistance and dryness. More particularly, this invention involves paper made from cellulose pulp modified by oxidation mediated by the nitroxyl radical and containing additives comprising the polymers containing functionality capable of reacting with aldehyde or functional polymers with aldehyde. This invention also involves paper made from aldehyde modified cellulose pulp wherein a hydroxyl group-containing material is added to the papermaking operation to provide unexpected additional moisture resistance, dryness resistance, and / or properties of ratio of moisture resistance / dryness resistance to the resulting paper product. The term "paper" as used herein, includes sheet-like masses and molded products made of pulp or fibrous cellulose material which can be derived from natural sources. The paper can also be made from synthetic cellulose fibers and regenerated cellulose as well as recycled waste paper. In addition, paper made from combinations of cellulosic and synthetic materials are applicable herein. The cardboard is included within the broad term of "paper". Papermaking, as is conventionally known, is a process for introducing an aqueous slurry of pulp or wood cellulosic fibers (which have been baked or refined to achieve a level of fiber hydration and to which a variety of functional additives can be added) in a sieve or similar device in such a way that water is removed, thus forming a sheet of consolidated fibers, which under pressure and drying can be processed in a dry roller or sheet form. Typically in papermaking, feeding or entering a papermaking machine is an aqueous suspension or suspension of pulp fiber water that is provided from what is called the system. "wet end". At the wet end, the pulp together with other additives are mixed in an aqueous suspension and subjected to mechanical and other operations such as shaking and refining. Various additives are commonly added to help provide different properties in the paper product. The use of functional aldehyde additives in the paper industry as agents of resistance to moisture and dryness is well known. For example, both oxidative and non-oxidative methods are known to introduce aldehyde groups into starch. The use of these products in the manufacture of paper to provide properties of resistance to dryness and moisture involves the addition of this separate starch additive component. The United States Patent NO. 5,698,688 assigned to D.J. Smith et al. on December 16, 1997 describes the aldehyde-modified cellulose fibers formed of esterified 1,2-disubstituted alkenes and which are useful in providing paper products with moisture-resisting properties. The copending application NO. serial 09/373, 393 filed on August 17, 1999, describes the preparation of aldehyde-modified cellulose pulp using selected oxidation conditions. In that application, the aldehyde-modified cellulose pulp products having improved moisture resistance and drying resistance properties are described. While the known methods for preparing paper as described above provide products with good moisture resistance and dryness properties, there is always a need for paper products having significantly improved strength properties.

It has now been discovered that paper comprising aldehyde-modified cellulose pulp prepared using defined nitroxyl oxidation conditions and further containing selected additives comprising polymers containing functionality capable of reacting with aldehyde or functional polymers with aldehyde surprisingly have strength properties to significantly improved moisture and dryness. More particularly, this invention relates to aldehyde modified cellulose pulp with improved moisture resistance and dryness properties where the pulp is prepared in an aqueous solution with an oxidant having equivalent oxidation powder of up to 0.5 g of active chlorine per 100 g of cellulose and an effective amount of mediation of nitroxyl radical, the reaction being carried out at a pH of about 8.0 to 10.5 and a temperature of about 5 to 50 ° C and furthermore containing an effective amount of an additive comprising a polymer which contains functionality capable of reacting with aldehyde and selected from the group consisting of hydroxyl, amino, amido, thiol, imide and carboxylic acid groups, or functional polymers of aldehyde. In another embodiment, this invention relates to paper made from aldehyde-modified cellulose pulp wherein a hydroxyl group containing material is added to the papermaking operation to provide moisture resistance properties, resistance to drying, and / or properties of proportion of moisture resistance / dryness resistance in the resulting paper product. The paper product of this invention involves aldehyde-modified cellulose pulp prepared using nitroxyl-mediated oxidation conditions and which additionally contain additives selected to improve moisture resistance, dryness resistance, and / or properties of moisture resistance ratios. resistance to dryness comprising polymers containing functionality capable of reacting with aldehyde or functional polymers of aldehydes. The additives used in this invention can be polymers containing functionality capable of reacting with aldehyde and will contain at least two functional groups of reactive aldehyde reagents, particularly more than two functionalities of reactive aldehydes per polymer chain or molecule. More particularly, the polymer with reactive aldehyde functionality will be selected from the group consisting of hydroxyl, amino, amido, thiol, imido, and carboxylic acid groups or the alkali, alkaline earth or ammonium salts thereof, or combinations thereof. same. Hydroxyl groups are more particularly suitable. Polymers of additives with hydroxyl groups include carbohydrates or polysaccharides such as starch, cellulose, gums and derivatives thereof. Exemplary polymeric additives with hydroxyl groups include carbohydrates or polymers of polysaccharides or modified carbohydrate polymers such as starch or starch derivatives; guar gum or guar gum derivatives such as hydroxypropyltrimonium guar hydroxypropyl chloride, hydroxyethyl cellulose, polyquaternium-4 derivatives, polyquaternium-10, dextran or dextran derivatives, swarm or pululan derivatives, corn fiber gum or derivatives of corn fiber gum, arabinogalactan or arabinogalactan derivatives and bean gum locust; polyvinyl alcohol or copolymers of vinyl alcohol with other monomers, which are typically prepared by hydrolysis of vinyl acetate copolymers with other monomers; and copolymers of hydroxyl alkyl esters of acrylic or methacrylic acid such as 2-hydroxyethyl methacrylate with other copolymerizable monomers. Useful carbohydrate derivatives include cationic, anionic, amphoteric, ester and ether derivatives with cationic and amphoteric derivatives which are particularly suitable. It is further noted that polymers containing hydroxyl groups may contain other substituent groups. The polymers with amino groups are illustrated by poly (vinylamine) or vinyl amyla copolymers, which are They are typically made by hydrolysis of venom formamide copolymers and other copolymerizable monomers, poly (ethylene imine) and poly (ethylene imine) derivatives and chitosan. Examples of polymers with amido groups include poly (acrylamide) or polymers of acrylamide with other copolymerizable monomers, poly (vinylformamide), or copolymers of vinylformamide and poly (vinylacetamide) or copolymers of vinylacetamide. Exemplary imido-containing polymers include (poly (maleimide) and copolymers of maleimide with other copolymerizable monomers Polymers containing carboxylic acid functionality or the alkali, alkaline earth or ammonium salts thereof, include homopolymers or copolymers with other copolymerizable monomers of (meth) acrylic acid and alkaline earth or ammonium salts thereof, crotonic acid, monomers containing dicarboxylic acid such as maleic, fumaric and itaconic acids and anhydrides, the middle esters of unsaturated dicarboxylic acids such as methyl hydrogen fumarate, butyl hydrogen fumarate, ethyl hydrogen maleate, butyl hydrogen maleate and alkaline, alkaline earth or ammonium salts thereof The additives used in this invention can be functional polymers of aldehyde and more particularly functional polymers of aldehydes containing two or more aldehydes by polymer chain or molecule Functional polymers aldehydes include aldehydes of tiles 5 polysaccharides having the general structure: Sacch-0-CH2-R-C-N-R2-CHO (I) R, 10 OH Sacch-O-CH-C-CHO (II) R3 R4 OH R6 Sacch - O - CH2 - CH - R5 - N * - R8 - CHO Y "(" D 15 R7 or Sacch - O - g - CHO (IV) 20 wherein Sacch represents a polysaccharide molecule such as starch, cellulose or a gum; R is (CH2) n or a divalent aromatic group and n is zero or more; Ri, R6 and R7 are hydrogen, an alkyl (particularly methyl), Aryl, aralkyl or alkaryl group; R2, R5 and Rs are (CH2) m with m which is 1 to 6, particularly 1 to 2; R3 and R4 are hydrogen or lower alkyl, particularly methyl; Rg is a divalent organic group, which contains no reactive substituents without starch and Y is an anion such as halide, sulfate or nitrate. The polysaccharide molecule can be modified by the introduction of cationic, anionic, nonionic, amphoteric and / or zwitterionic substituents. The polysaccharide aldehyde derivatives I to IV can be prepared by a non-oxidative method which involves reacting the polysaccharide base with a derivatization acetal reagent in the presence of alkali. Further description of these aldehyde derivatives and the method of preparation as further described in U.S. Patent No. 4,675,394 assigned to D. Solarek et al., On June 23, 1987, the reference incorporated herein by reference. reference. Other useful starch aldehyde derivatives include those prepared by the selective oxidation of starch using a limited amount of oxidant and a nitroxyl radical mediator of starch using a limited amount of oxidant and a nitroxyl radical mediator. Such amidon aldehyde derivatives can be prepared by oxidizing starch in an aqueous system with an oxidant having an equivalent oxidation power of up to 14.18 g of active chlorine per mole of anhydrous glucose unit of starch and an effective mediating amount of nitroxyl radical , the reaction carried out at a temperature of no more than about 15 ° C and at a pH of about 8.0 to 10.5. The resulting starch aldehyde derivatives can have up to 15 mol% of C-β aldehyde groups per mole of anhydroglucose units of starch and minimum carboxylic acid content. Additional aldehyde derivatives that can be used as additives include those derived from guar gums and starch that have been oxidized using an enzyme such as galactose oxidase as described in US Pat. No. 3, 297,604 assigned to F. Germino on January 10, 1967 and 4,663,448, assigned to C. Chiu on May 5, 1987. Dialdehyde starches prepared by methods such as the oxidation of starch with periodic acid are described in the US Pat. No. 3,086,969, assigned to JE Slager on April 23, 1963, and dialdehyde gums using periodate or periodic acid are described in U.S. Patent No. 3,062,652 assigned to R. Jeffreys et al. on November 6, 1962. Other functional polymers of useful aldehydes or compounds include those obtained by the addition of glyoxal to poly (acrylamide) polymers and copolymers as described in United States Patent 3,740,391 assigned on June 19, 1973 to L. Williams et al., as well as glyoxal or glutaraldehyde.

JÉÜaa. **. mk, * * t. , ~? »I? ~~ The functional aldehyde polymer additives can be used either alone or together with any polymer additives mentioned above which contain functionality capable of reacting with aldehyde groups. In addition, polymer additives that contain both aldehyde functionality and functionality capable of reacting with aldehyde groups can be used. The polymer additives used in this invention can be added to the oxidized pulp at any time in the papermaking process. If they are added at the wet end, the additive polymers carrying a net cationic charge are particularly suitable. The cationic charge can be introduced into these polymers or other materials by a number of different means known in the art. For example, if the additive is either a polymer containing functionality capable of reacting with aldehyde or an aldehyde functional polymer that is made by polymerization of free radicals of copolymerizable monomers, a positive charge can be introduced into the copolymer by including it in the copolymerization a cationic monomer such as (3-acrylamidopropyl) trimethylammonium chloride, [2- (acryloxoi) ethyl] trimethylammonium methylisulfate, 2- (dimethylammo) ethyl acrylate, [3- (methacryloylamino) propyl] trimethylammonium chloride, methylisulfate [2- (methacryloyloxy) ethyl] trimethylammonium, 2- (dimethylamino) ethyl methacrylate, 2-aminoethylmethacrylate hydrochloride, diallylmethylammonium chloride, imidazolvinyl and vinylpyrrolidine and substituted derivatives thereof. Alternatively, the positive charge can be introduced by reaction of the additive polymers with reactants carrying a positive charge as described in "cationic starches" by D. Solarek in Modified Starches: Properties and Uses, chapter 8, 1986 and in the patent. of the United States NO. 4,119,487 assigned on October 10, 1978 to M. Tessler. The additive can also be sprayed or applied to the wet web either as an uncooked solution, dispersion or suspension. The cellulose pulp aldehyde derivatives used in this invention are prepared by a method involving nitroxyl-mediated oxidation. More particularly, the cellulose pulp aldehyde derivatives are prepared by a method involving the selective oxidation of cellulose and cellulose pulp or fibers using a limited amount of oxidant mediated with a nitroxyl radical under defined conditions to provide derivatives with aldehyde content. made particularly suitable for use to provide paper with desired moisture resistance, temporary moisture resistance and dryness resistance properties. The nitroxyl radical mediator used in the present is a nitroxyl diterciary alkylo radical having one of the following formulas: where A represents a chain of particularly two or three atoms, in carbon atoms or a combination of one or two carbon atoms with an oxygen or nitrogen atom, and the R groups represent the same different alkyl groups. Chain A can be substituted by one or more groups such as alkyl, alkoxy, aryl, aryloxy, amino, oxido groups, or by a divalent group or multivalent group which is linked to one or more groups having the formula I. Radicals particularly useful nitroxyl are di-tertiary alkyl nitroxyl radiacles having the formula: ** .... ill11 .. ». * .-,. t.

Or where Y is either H, OH or NH-C-CH3 and each of the R groups represent the same or different alkyl groups of 1 to 18 carbon atoms and more particularly methyl groups. Nitroxyl radiacles of this type include those where a) the R groups are all methyl (or alkyl of 1 carbon atom) and Y is H, ie, 2, 2, 6, 6-tetramethyl-1-piperidinyloxy (TEMPO); b) R groups are methyl and X is OH and is identified as 4-hydroxy-TEMPO; and c) R groups are methyl and X is O NH-C-CH3 and is identified as 4-acetamido-TEMPO. A particularly suitable nitroxyl radical is TEMPO or 4-acetamido-TEMPO. The nitroxyl radical is used in an amount effective to mediate oxidation, more particularly from about 0.001 to 20% by weight, more particularly from about 0.01 to 0.1% by weight, based on the weight of cellulose, cellulose pulp or fiber. The nitroxyl radical can be added to the reaction mixture or generated in situ from the corresponding hydroxylamine or oxoamonium ion. The oxidant used in this invention can be any material capable of converting nitroxyl radicals to their corresponding oxoammonium salt. Particularly useful oxidants are alkali metal or alkaline earth hypohalite salts such as sodium hypochlorite, Lithium hypochlorite, potassium hypochlorite or calcium hypochlorite. The alkali metal or alkaline earth hydrobromite salt can also be used and this can be added in the form of the hypobromite salt itself, such as sodium hypobromite, or this can be formed in situ from the addition of an oxidant. suitable such as sodium hypochlorite and an alkaline or alkaline earth metal bromide salt such as sodium bromide. The bromide ion is usually in the form of sodium bromide. Additional oxidants that can be used in this method include hydrogen peroxide in combination with a transition metal catalyst such as methyltrioxorenium (VII); hydrogen peroxide in combination with an enzyme; oxygen in combination with a transition metal catalyst; oxygen in combination with an enzyme; peroxyacids such as peracetic acid and 3-chloroperoxybenzoic acid; alkali metal or alkaline earth salts of persulfates such as potassium persulfate and sodium persulfate; alkali metal or alkaline ferrous salts of peroxymonosulfates such as potassium peroxymonosulfate; chloramines such as 1,3,5-trichloro-1,3,5-triazine-2, 4, 6 (1H, 3H, 5H) trione, 1,3-dichloro-1,3,5-triazine-2 salt , 4, 6 (1H, 3H, 5H) friona sodium, 1,3-dichloro-5,5-dimethylhydantoin, 1-bromo-3-chloro-5,5-dimethylhydantoin and 1-chloro-2, 5-pyrrolidinedione; and alkali metal or alkaline earth salts of ferricyanide. She is ready of oxidants is only illustrative and is not proposed to be exhaustive. The oxidants can be used alone or in combination with an alkali metal or alkaline earth metal bromide salt. A particularly suitable oxidant is sodium hypochlorite or sodium hypobromite formed from the addition of sodium hypochlorite and sodium bromide. The important factor in the use of the oxidant is that it should be used in a limited amount that has the equivalent oxidant power of up to 5.0 g of active chlorine per 100 g 10 cellulose or cellulose pulp. More particularly, the amount of the oxidant used will have an equivalent oxidizing power of about 0.05 to 5.0 g of active chlorine, more particularly of about 0.5 to 2.5 g of active chlorine per 100 g of cellulose or cellulose pulp. When 15 uses sodium hypochlorite, is used in a limited amount of up to about 10 weight percent based on the weight of cellulose or cellulose pulp, more particularly of about 0.1 to 10%, more particularly about 1 to 5% by weight based on the weight of the cellulose 20 or cellulose pulp. The bromide will be used in the form of a sodium bromide generally in an amount of about 0.1 to 5% by weight and particularly about 0.25 to 2% by weight based on the weight of the cellulose or cellulose pulp. By limiting the amount of oxidant under defined aqueous conditions, the derivatives of - faAtjm., -. riti-imé i * l.?.?SSi. i ...

Cellulose aldehyde are selectively prepared at high effective aldehyde levels. Such high aldehyde cellulose products are particularly useful for preparing paper with moisture resistance, temporary moisture resistance, resistance to dryness and high dryness / resistance to dryness properties. The cellulose material used as the starting material can be any cellulose, cellulose fiber or pulp material. This includes soft wood or hardwood such as bleached or unbleached sulphate (Kraft), bleached and unbleached sulphite, bleached and unbleached soda, neutral sulfite, quimo-wood underground, and any combinations of these fibers. . In addition, the synthetic cellulose fibers of rayon 15 of viscose or type of regenerated cellulose can also be used, as well as recycled waste papers from various sources. The water consistency of the cellulose or pulp that is used will be from about 0.1 to 15% by weight of solids in water, particularly from about 1 to 5% in weight. 20 weight. When used in papermaking, other additives such as desired inert fillers or retention aids to cellulose pulp can be added. Such materials include clay, titanium dioxide, calcium carbonate, calcium sulfate and earth 25 diatom. They can also be present, if desired, rosina or synthetic internal size. The oxidation reaction of the cellulosic material is carried out in an aqueous solution. The pH of the reaction is maintained at about 8.0 to 10.5, particularly about 9 to 10, the temperature is maintained at about 5 to 50 ° C, particularly about 20 to 30 ° C. The extent of the reaction is controlled by the amount of oxidant used or the reaction time. Generally the reaction time will be from about 5 to 60 minutes, and more particularly from about 20 to 30 minutes. By using the amounts of reagent and components as defined above and the indicated reaction conditions, controlled amounts of aldehyde functionality, particularly C-β aldehyde, can be obtained which are suitable and effective to provide desired moisture resistance, resistance to Temporary moisture, and dryness resistance properties and desired moisture resistance / dryness resistance ratios in the prepared paper product. The aldehyde derivatives prepared according to this invention will have aldehyde functionality of about 1 to 20 and particularly about 5 to 20 mmoles / 100 g of cellulosic material, i.e., cellulose or cellulose pulp. The carboxylic acid functionality will also be generated or formed during the oxidation process. The amounts of carboxyl content generated will generally be from about 1 to 40 mmole / 100 g of cellulose or cellulose pulp, particularly from about 1 to 20 and more particularly from about 1 to 10 mmole / 100 g of cellulose or cellulose pulp. It should be noted that this amount of carboxylic acid functionality is additional to that which may already be present in cellulose or cellulose pulp naturally or by virtue of the type of processed pulp used, such as bleached sulfate, bleached sulphite, etc. The effective level of the aldehyde is an important aspect of this invention and one way in which this can be defined is by the proportion of aldehyde to generated carboxylic acid functionalities. Such levels can be defined by proportions of aldehyde to generated carboxylic acid functionalities. Such levels can be defined by proportions of aldehyde to carboxylic acid generated more than or equal to 0.5 (based on the mmoles / 100 g of cellulose or cellulose pulp of each functionality) and particularly greater than or equal to 1.0. While recognizing that the amount of additional carboxylic functionality (ie, different from that generated) will vary and may be almost low, however, there is something present and this will affect the level of total carboxylic acid functionality. Considering this and based on the total carboxylic acid, the ratio of aldehyde to carboxylic acid functionality will be about 0.2 or more. The significance of this aldehyde content is particularly manifested in the resulting properties found in paper prepared from the oxidized cellulose material. Moisture resistance properties, temporary moisture resistance and high dryness resistance are found. Products having high moisture resistance / dryness strength ratios of greater than 20% have been obtained on paper using these selectively modified cellulose aldehyde derivatives indicating improved properties such as softness. In another embodiment of this invention, the hydroxyl group containing polymers as previously described, can be used with any cellulose pulp 15 modified with aldehyde to further provide properties of improved moisture resistance and dryness resistance. This is especially unexpected since the polymer additives containing the hydroxyl group have not been known to provide resistance properties to 20 moisture to the paper. Additionally, the ratio of moisture resistance / dryness resistance is significantly improved by the use of such polymer additives containing the hydroxyl group with improved pulp cellulose. This improved proportion is due to higher 25 increase in the percentage of moisture resistance that the corresponding percentage increase in resistance to dryness. Products that have high moisture resistance / dryness resistance ratios of more than 25% have been obtained. The cellulose pulp modified with 5-aldehyde as used in this embodiment can be pulp provided by any method including, but not limited to, oxidation mediated by nitroxyl radical as described herein and the aldehyde-modified cellulose fiber formed of 1, 2-disubstituted alkenes 10 esterified as described in U.S. Patent 5, ß98, ß88 assigned to DJ Smith et al. on December 1, 1997. It is noted that the use of modified aldehyde cellulose derivatives as described herein for papermaking may involve the use of such derivatives as whole or total pulp or paper supply or these they can be used as a component of the paper supply (ie in quantities of 20, 40, 60% by weight, etc.). The proportion of additive polymers to be incorporated into the paper pulp can vary according to the particular cellulose pulp modified with particular aldehyde involved and the desired properties. In general, it is desired to use about 0.05 to 15% and particularly about 0.1 to 5% of the additive by weight based on the dry weight of the pulp. Within this range, the amount ^^ gtg MÉÉÉÉg precise that it is used will depend on the type of pulp that is used, the specific operating conditions and the particular final use for which the paper is proposed. Any desired inert fillers can be added to the pulp containing the additive polymers of this invention. Such materials include clay, titanium dioxide, talc, calcium carbonate, calcium sulfate and diatomaceous earths. Other additives commonly introduced in paper to the pulp may also be added, for example, dyes, pigments, sizing additives such as rosin or synthetic internal size, alum, anionic and cationic retention aids, microparticle systems, etc. The following examples will more fully illustrate the embodiments of this invention. In the examples, all parts and percentages are by weight and all temperatures in degrees Celsius unless otherwise indicated. Also, when it refers to the pulp in weight, it is the weight of the pulp per se, that is, it includes the moisture content in equilibrium. EXAMPLE 1 Modification of Northern Softwood Kraft pulp (NSK) To a stirred suspension of 1600 g of NSK pulp in 3% consistency (48 g of pulp) 4.8 mg of 4-acetamido-TEMP and 0.24 g of sodium bromide [ 0.01% and 0.5%] in -MtJk? A * i * pulp weight (pp) respectively]. The pH of the mixture is adjusted to 9.5 with 0.49 N of sodium hydroxide. Sodium hypochlorite (7.93 g, 12.1% solution, 2% pp), whose pH is also adjusted to 9.5 using concentrated HCl, is then added all at once and the mixture is stirred at 25 ° C for 30 minutes. The pH of the suspension is maintained throughout it using a Brinkmann pH STAT 718 Titrino in 9.5 with 0.49 N NaOH (6.8 ml). At the end of the treatment period, the reaction is terminated by adding ascorbic acid to the mixture until its pH is decreased to the range of 4.0 to 4.5 (ca. The pulp is filtered and washed extensively with water whose pH is adjusted to 4.5 to 5.5. This is then resuspended in water for subsequent use in leaf-by-hand or air-drying at room temperature for future use. Determination of the Modified Pulp Aldehyde Content: The aldehyde content of the modified NSK pulp is determined using hydroxylamine hydrochloride titration via derivatization of oxime to the next reaction and procedure. RCHO + NH20H.HC1? RCHNOH + HCl The slurry of oxidized pulp in water 12000 g in 2% consistency is adjusted to pH 4 with aqueous HCl. A large excess of a solution is added in drops to this mixture The aqueous solution of 2M hydroxyallamine hydrochloride solution (ca. 15 ml), whose pH is also adjusted to 4 with HCl. During the reaction, the pH of the mixture is maintained at 4 by titration with a 0.49 N NaOH solution using a Brinkman pH STAT 718 titration. The titration is continued until no further reduction in pH of the mixture can be detected. (ca. 1 h). The aldehyde content is then calculated to be 8.4 mmoles / 100 g of pulp of the total NaOH consumption (4.1 ml) using the following equation: Mmoles / 100 g-CH0 = (ml of titul of NaOH x N of NaOH x 100) / (weight in g of pulp) Carboxylic acid content of modified pulp: The level of carboxylic acid formed during the NSK pulp modification of the amount of NaOH titrant consumed is calculated to maintain the pH of the reaction (6.8) ml of solution 9.49 N). This provides a direct measurement of the additional carboxylic acid generated in the pulp which has 6.9 mmol.es/100 pulp, calculated using the following equation: Mmoles / 100 g-C00H = (ml of titul of NaOH x N of NaOH x 100) / (weight in g of pulp) EXAMPLE 2 Modification of hardwood pulp: It is added to a stirred suspension of 1600 g of hardwood pulp in 3% consistency (48 g of pulp) > ... i. . JA .. 4. 8 mg of 4-acetamido-TEMP and 0.24 g of sodium bromide. The pH of the mixture is adjusted to 9.5 with 0.49 N sodium hydroxide. Sodium hypochlorite (7.93 g, 12.1% solution, 2% pp) is then added, whose pH is also adjusted to 9.5 using concentrated HCl, all of once and the mixture is stirred at 25 ° C for 30 minutes. The pH of the suspension is maintained throughout it using Brinkmann pH STAT 718 Titrino at 9.5 with 0.49 N NaOH, consuming 4.2 ml. At the end of the treatment period, the reaction is terminated by adding ascorbic acid to the mixture until its pH is decreased to the range of 4.0 to 4.5 (ca. The pulp is filtered and washed extensively with water whose pH is adjusted to 4.5 to 5.5. It is resuspended either in water for subsequent use in sheet manufacture by hand or air drying at room temperature for future use. The aldehyde and carboxylic acid contents of the modified hardwood pulp are determined as described in example 1 and are 7.7 mmoles and 4.3 mmoles respectively per 100 g of pulp. EXAMPLE 3 The modified pulp samples described in Examples 1 and 2 (600 to 650 CSF) are formed into 18 lb / 3300 ft3 hand-made sheets of 0.3% consistency and at a pH of 5%. 6 in a M / K sheet former according to the TAPPI 205 standard T test method. Wet end additives (such as 0.5 to 1.0% cooking or water solutions) are introduced to the pulp suspension in a Waring blender and mix for 30 seconds before sheet formation. Addition levels vary between 2.5 to 20 pounds per ton (lb / t) of pulp given in the individual examples. The hand-made conditioned leaves (25 ° C and 50% RH) are cut into strips (1"wide) which are then tested for resistance to initial moisture and resistance to dry stress at the breaking point according to the Standard Methods TAPPI T 456 and 494. Table 1 illustrates the effect of various polyhydroxyl additives of cationic starch (CATO (MR) 232 and REDIBONDMR 5330a starch from National Starch and Chemical Company) on paper strength properties when used in combination with the soft wood pulp modified with aldehyde described in Example 1. TABLE 1 The effect of polyhydroxyl cationic starch additives on paper-strength properties on soft wood pulp NSK mociií Cicada with aldehydc). paper Wood Starch Resistance level Resist Soft proportion cationic NSK addition to ion density (lb / t) voltage wet tension / s wet dry eco (%) '-' • * - '**' • ilaa - > * Wax maize starches modified with 3-chloro-2-hydroxylpropyltrimethylammonium chloride (QUAT); cationic nitrogen = 0.30%. The results show significant additional improvements that are obtained in both wet and dry resistances as well as the wet / dry ratio of the hand sheets when using cationic starch of the polyhydroxyl compound type in combination with the soft wood pulp of aldehyde and carboxylate . EXAMPLE 4 This example illustrates the use of cationic starch of the polyhydroxyl compound type (CATO 232 from National Starch and Chemical Company) as a dry or wet strength additive in combination with the aldehyde-modified hardwood pulp prepared in Example 2 after of the general procedure described in Example 3 (Table 2). Table 2 The cationic effect of the polyhydroxyl additive on paper strength properties based on aldehyde-modified hardwood pulp.

* CATO 232: 3-chloro-2-hydroxypropyltrimethylammonium chloride modified with waxy maize; cationic nitrogen = 0.30% The results show significant additional improvements that are obtained in both wet and dry resistances as well as the wet / dry ratio of the sheets made by hand when using the polyhydroxyl compound of the cationic starch type in combination with the pulp of modified hard wood with aldehyde and carboxylate. EXAMPLE 5 The example illustrates the use of a cationic starch aldehyde (CO-BONDMR 1000 Plus starch from National Starch and Chemical Company) as a wet and dry strength additive in combination with the soft wood modified with aldehyde and prepared hardwood pulp in Examples 1 and 2 after the general procedure described in Example 3 (Table 3). TABLE 3 The Effect of a Functional Starch Additive with Aldehyde on Paper Resistance Properties in Aldehyde-Modified Pulps fc ** ** Wax maize starch modified with 3-chloro-2-hydroxypropyltrimethylammonium chloride and 2-chloro-N- (2, 2-dimethoxyethyl) -N-methylacetamide; Cationic nitrogen = 0.3% and acetal nitrogen = 0.4%, respectively. The results show the additional improvements ttt'-i? ? t J. The results are obtained in both wet and dry resistances as well as the wet / dry ratio of the hand-made sheets when the cationic starch aldehyde is used in combination with the aldehyde and soft wood pulp. and lasts modified with carboxylate and aldehyde. EXAMPLE ß This example demonstrates the use of other polymers containing the hydroxyl group of the cationic polysaccharide type [Chitosan from Sigma Corporation, cationic cellulose, (cellulose resin derived from CELQUAT® H-100, Polyquaternium-4) and cationic guar gum ( 3-chloro-2-hydroxypropyltrimethyl-ammonium chloride modified with guar gum; cationic nitrogen = 0.30% from National Starch and Chemical Company)] as well as wet and dry strength additives in combination with the aldehyde modified NSK soft wood pulp prepared in Example 1 following the general procedure described in Example 3 (Table 4). TABLE 4 The effect of polymers containing the hydroxyl group of the cationic polysaccharide type as additives in paper strength properties are based on mild wood pulp modified with aldehyde. sa s & The results show significant additional improvements obtained in both wet and dry resistances as well as the wet / dry ratio of the sheets made by hand when several polysaccharides are used in combination with the pulps modified with aldehyde and carboxylate. . EXAMPLE 7 Synthesis of Terpolymer Containing the Hydroxy Group Poly (MAPTAC-co-DMA-co-HEMA) This example describes the synthesis of several terpolymers. { poly ([3- (methacryloylamino) propyl] trimethylammonium (MAPTAC) -co-N, N-dimethylacrylamide methacrylate (DMA) -co-2-hydroxyethyl (HEMA)} for use as a temporary moisture resistance additive with the aldehyde-modified pulps. The following procedure is used for the synthesis of terpolymer B (Table 5). Polymers A and C-K (Table 5) are prepared with different amounts of the monomers using a similar procedure. A four-neck round-bottomed flask is equipped with a mechanical head agitator, two pressure-equalizing addition funnels, one attached to a bypass adapter connected to a "Y" adapter and the second vertically connected to the "Y" adapter, thermometer, and a reflux condenser with the top with a nitrogen inlet. Correct for the purity of each component (50% MAPTAC, 99% DMA, 97% HEMA, 97% ammonium persulfate), weighed the monomers (MAPTAC anhydrous 0.63 g, DMA 9.42 g, HEMA 2.53 g) in a glass of precitados. The mixture of the monomers is then diluted with refined water for a total weight of 125 g. This solution is transferred to an addition funnel. The second addition funnel is then charged with an ammonium persulfate solution, which is prepared by dissolving ammonium persulfate (0.06 g, 0.5 percent by weight) with 125 grams of refined water in a beaker. Both funnels are closed at the top by a rubber septum, and purged with nitrogen for 20 minutes. An initial charge consisting of 25 ml of the monomer solution is then introduced, and 25 ml of the initiator solution is introduced into the reaction reactor. After shaking the initial charge at a temperature of 65 to 70 ° C for 30 minutes, both monomer and initiator solutions are added dropwise simultaneously over a period of 1.5 hours while maintaining a temperature of 65 to 70 ° C with a oil bath. At the conclusion of the slow additions, the polymerization solution is maintained at a temperature of 65 to 70 ° C for an additional 4 to 5 hours. The flask is then cooled to room temperature, and the polymer lacquer is collected. It is dried by freezing a small portion of the lacquer for characterization. The polymers are characterized for conversion, concentration, and molecular weight. The conversion of monomers to polymer is followed by dissolving the dried polymer by freezing in deuterium oxide (D20) and performing 1H or 13C NMR spectroscopy. The concentration of the polymer lacquer (generally 5.0 to 5.5%) is determined by measuring the difference in weight before and after heating a small sample at 105 ° C in an oven for 1 hour. The inherent viscosity (IV) (2.2 dl / g) is measured using 0.1 g / 100 ml of polymer in 0.1 N potassium chloride at a temperature of 25 ° C. Table 5 lists the series of terpolymers by varying the composition of MAPTAC, DMA and HEMA that is synthesized and their effectiveness as moisture and dry strength additives in combination with the soft wood pulp modified with aldehyde. Table 5 Synthetic copolymers with functional hydroxyl as paper strength additives with mild wood pulp modified with aldehyde.

* Used at 10 lb / t. »Ugly» < "__- l - * - '* BMHMyfllMM> t» EXAMPLE 8 This example demonstrates the use of several synthetic polymers with different aldehyde-reactive functional groups as wet and dry strength additives in combination with modified NSK softwood pulp with aldehyde prepared in Example 1 following the general procedure described in Example 3 (Table ß) [Cat- PVOH = cationic poly (vinyl alcohol) (from Kurarays Co. Ltd., Polymer CM-318), PAM = poly (chloride) of acrylamide-co-diallyldimethylammonium) (ex Aldrich), Polymin PR971L = poly (ethylenimine) (ex BASF)] EXAMPLE 8 The effect of various synthetic polymers containing the aldehyde-reactive functional group as additives on paper strength properties is based on soft wood pulp modified with aldehyde.

EXAMPLE 9 This example describes the spray application of some of the hydroxyl functional additives for already made handmade sheets made of mild wood modified with aldehyde. Therefore, after the preparation and hand-made sheets as described in Example 3, several synthetic and natural functional hydroxyl polymers are applied to hand-made sheets by spraying uniformly on both sides of 0.5 to 1% of solutions using a Atomizer held by hand. Additions of the polymer are calculated based on the weight gained from wet sheets that are allowed to dry at room temperature in air. They are then conditioned and tested as described in Example 3. The results are given in Table 7. [PVOH = polyvinyl alcohol (98% hydrolyzed, MV 124,000 to 186,000 from Aldrich), Frodex 20 = 20 maltodextrin (from American Maize Corp.), Pullulan (from Polysciences Corp.)]. TABLE 7 The application of functional hydroxyl polymer spray to handmade sheets made of soft wood modified with aldehyde and its effect on the strength properties.

Claims (1)

1. CLAIMS 1. In the method for making paper having wet strength, temporary wet strength, dry strength and high dry strength / resistance properties, the improvement characterized in that it comprises using an aldehyde-modified cellulose pulp as the provision of pulp that is prepared by oxidizing cellulose or cellulose pulp in an aqueous system with an oxidant that has an oxidation power equivalent to 10 about 5.0 g of active chlorine per 100 g of cellulose and an effective mediating amount of nitroxyl radical, and adding an effective amount of at least one additive comprising functional polymers of aldehyde or polymers containing functional groups capable of reacting with groups 15 aldehyde. The method according to claim 1, characterized in that the aldehyde reactive functional group in the additive polymer is selected from the group consisting of hydroxyl, amino, amitium, thiol, imido and carboxylic acid, Or the alkali, alkaline earth or ammonium salts thereof. 3. The method according to claims 1-2, characterized in that the aldehyde reactive functional group is a? hydroxyl rupo. 25 4. The method of compliance with ^^ - ?? iMa? ami claims 1-3, characterized in that the oxidation reaction is carried out at a pH of about 8.0 to 10.5 and a temperature of about 5 to 50 ° C. 5. The method according to claims 1-4, characterized in that the cellulose pulp has from about 1 to 20 mmol of aldehyde per 100 g of cellulose. 6. The method according to claims 1-5, characterized in that the nitroxyl radical catalyst has the formula: Or wherein Y is H, OH, or NH-C I! -CH3 7. The method according to claims 1-6, characterized in that the reactive aldehyde functional group in the additive polymer is selected from the group consisting of hydroxyl, amino, amido, thiol, imido and carboxylic acid, or the alkali, alkaline earth or ammonium salts thereof. 8. The method of compliance with - * • * - »-» - * - • ¿'»» •'. -t.-Claims 1-7, characterized in that the reactive aldehyde functional group in the additive polymer is a hydroxyl group. 9. The method according to claim 5, characterized in that about 0.05 to 15% by weight of the additive is used based on the dry weight of the pulp. 10. The paper characterized in that it is made by the method according to claims 1-9. 11. In the method for making paper having wet strength, temporary wet strength, and wet strength / high dry strength properties, the improvement is characterized in that it comprises using aldehyde-modified cellulose pulp as the pulp supply and adding 15 an effective amount of a polymer containing the hydroxyl group. The method according to claim 11, characterized in that the polymer containing the hydroxyl group is a carbohydrate selected from the group 20 consists of starch, cellulose and gum. The method according to claims 11-12, characterized in that about 0.05 to 15% by weight of the additive is used based on the dry weight of the pulp. 25 14. The method of compliance with claims 11-13, characterized in that the carbohydrate is a derivative selected from the group consisting of cationic, anionic, amphoteric, ester and ether derivatives. 15. The paper characterized in that it is made by the method according to claims 11-14. j ^ ß ^ = É ^^ r * > *. * * teA