MXPA01001447A - Creping compositions and processes - Google Patents

Abstract

Composition comprising at least one water soluble polymer, such as polyamidoamine-epichlorohydrin resin, polyamine-epichlorohydrin resin, polyvinyl alcohol, etc. and at least one stabilizer, such as hypophosphorous acid, phosphorous acid, hypodiphosphoric acid, etc. and salts thereof, suitable as creping adhesive for paper.

Description

COMPOSITIONS AND ACRESPONEMENT PROCESSES BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to a stabilizer for creping adhesives and more particularly relates to a creping composition comprising water-soluble polymer and stabilizer comprising certain acids or salts thereof.

DESCRIPTION OF THE PREVIOUS TECHNIQUE The creping process is commonly practiced in the manufacture of tissue paper and paper towel categories. This process involves scraping the dry paper web from a drying cylinder (Yankee dryer) for the use of a creping blade. The creping action imparts a fine, wavy texture to the sheet and also increases the volume of the sheet, resulting in improved softness and absorbency. An adhesive formulation is often used to control the adhesion of paper to the Yankee dryer. In this regard, fibrous webs, particularly paper webs, are conventionally subjected to the creping process to give their desirable texture characteristics, such as softness and bulk. The creping process typically 1gffffft ^ e? * ~ * mt i * involves applying creping adhesive - generally in the form of an aqueous solution, emulsion or dispersion - to a drying surface for the fabric; preferably, this surface is the surface of a rotating creping cylinder, such as the apparatus known as a Yankee dryer. The fabric is then adhered to the indicated surface. This is subsequently dislodged from the surface with a creping device - preferably, a scraper blade. The impact of the fabric against the creping device breaks some of the fiber to fiber links within the fabric, causing the fabric to wrinkle or pucker. The solution, emulsion or dispersion of the creping adhesive may be comprised of one or more adhesive components, typically water-soluble polymers, and may also contain one or more release agent components as well as other desired additives that may affect the process of creping. This is known as the creping adhesive packaging. This adhesive is exposed to high temperatures (in the order of 100 ° C) and mechanical breakage raised to the creping blade. Given these conditions, one would expect the adhesive formulation to undergo thermooxidative degradation in the presence of atmospheric oxygen. In fact, the dark gum deposited is sometimes observed in the Yankee creping blade or dryer. These ^ A? E? ^? Mtt ^ deposits are probably thermooxidative degradation products of the creping adhesive formulation and may cause interruptions in the papermaking process. The present invention discloses additives for the creping adhesive formulation which significantly reduces the degradation of the creping adhesive formulation under its expected conditions of use. Espy & Maslanka, US Patent 5,388,807 and Espy & Giles, Canadian Patent 979,579, discloses polyamidoamine-epichlorohydrin resins (PAE resins) as adhesives in the creping process for making tissue paper products and paper towels. A number of patents disclose the use of hypophosphorous acid and its salts as an antioxidant in polymeric formulations. This includes Papero, US Patent 3,242,134 - < describes the use as a stabilizer for polyamides, Yoshitomi, Nagakura and Matsunuma, Japanese Patent 12,997 describes the use as an antioxidant in the preparation of alkyd resins, Schuler, Swiss Patent 326,175 describes the use of a light stabilizer for poly (vinyl chloride) and French Patent 1,391,335 (Imperial Chemical Industries Ltd.) describes the use as a stabilizer in the preparation of polyurethane foams.The polymers "described in the prior art as stabilized by hypophosphorous acid and its salts are all water-insoluble materials.There is no indication given in the prior art that these stabilizers could be worked in an aqueous system with a water-soluble polymer. No. 4,883,564 to Chen discloses a creping adhesive comprising a water-soluble binder (polyvinyl alcohol) and a phosphate salt to reduce the hard film strengthened on the creping surface of the drum dryer There is no description in the above references of additives used to impart thermal stability to the creping adhesive compositions There is no mention in the above references of oxidative instability neither of resins of polyamidoamine-epichlorohydrin or polyamine-epichlorohydrin, nor of the use of hypophosphorous acid and its salts as stabilizers for creping adhesives of polyamide oamine-epichlorohydrin or polyamine-epichlorohydrin.

SUMMARY OF THE INVENTION According to the present invention, there is provided a composition comprising at least one water soluble polymer selected from the group consisting of polyamidoamine-epichlorohydrin resin, polyamine epichlorohydrin resin, polyacrylamide, polyvinyl alcohol, polyvinylamine, polyethiienimine, polymethacrylamide, poly (acrylic acid), poly (methacrylic acid), poly (hydroxyethyl acrylate), poly (hydroxyethyl methacrylate), poly (n-vinylpyrrolidinone), poly (ethylene oxide), hydroxyethylcellulose, hydroxypropylcellulose, guar gum , starch, agar, chitosan, alginic acid, carboxymethylcellulose, highly branched polyamidoamines and silylated polyamidoamines; and at least one stabilizer selected from the group consisting of hypophosphorous acid, phosphorous acid, hypodiphosphoric acid, diphosphorous acid, hypophosphoric acid, pyrophosphorous acid and salts of any of these acids. According to the present invention, additional creping adhesives are provided which comprise at least one of the above water-soluble polymers and at least one of the above stabilizers. Provided according to the present invention there are creped paper forming processes comprising: (a) applying the water soluble polymer and stabilizer of the present invention to a drying surface for fibrous fabrics, (b) pressing a fibrous fabric against the drying surface to adhere the fibrous fabric to The drying surface, and (c) dislodging the fiber cloth from the drying surface with a creping device to crease the fibrous web.

DETAILED DESCRIPTION OF THE INVENTION Surprisingly it has been discovered that certain acids, such as phosphorous acid, hypophosphorous acid, etc., and their salts are effective additives in the prevention of thermal degradation of water-soluble polymers, for example, polyamidoamine-epichlorohydrin resins. and polyamine-epichlorohydrin. This type of stabilizer can be useful in the manufacture of tissue paper and paper towel by providing a more stable creping adhesive coating in the Yankee dryer. In the context of the present application the term "Polymer" is intended to include homopolymers as well as copolymers. The stabilizers have been shown to be effective in forming color reduction and calcination of water soluble polymers, such as polyamidoamine-epichlorohydrin resins and polyamine-epichlorohydrin at levels of about 1 to 5%. The water soluble polymer suitable for the present invention can be selected from the group consisting of polyamidoamine-epichlorohydrin resin, '^^ S ^^ M ^. polyamine resin epichlorohydrin, polyvinyl alcohol, polyvinylamine, polyetiienimine, acrylamide polymers, polymethacrylamide, poly (acrylic acid), poly (ethacrylic acid), poly (hydroxyethyl acrylate), poly (hydroxyethyl methacrylate), poly (n-vinylpyrrolidinone), poly (ethylene oxide), hydroxyethylcellulose, hydroxypropylcellulose, guar gum, starch, agar, chitosan, alginic acid, carboxymethylcellulose, highly branched polyamidoamines and its reaction product with epichlorohydrin and silylated polyamidoamines. Preferably, the water soluble polymer is selected from the group consisting of polyamidoamine-epichlorohydrin resin, polyamine-epichlorohydrin resin, highly branched polyamidoamines, silylated polyamidoamines, polyvinyl alcohol, polyvinylamine, polyethyleneimine, acrylamide polymers, poly (N-vinylpyrrolidinone)Hydroxyethylcellulose and carboxymethylcellulose and more preferably are selected from the group consisting of polyamidoamine-epichlorohydrin resin, polyamine-epichlorohydrin resin, highly branched polyamidoamines, silylated polyamidoamines, polyvinyl alcohol, polyvinylamine and polyethyleneimine. The stabilizer is selected from the group consisting of hypophosphorous acid, phosphorous acid, hypodiphosphoric acid, diphosphorous acid, hypophosphoric acid, pyrophosphorous acid and salts of any of these acids. Preferably, the stabilizer is hypophosphorous acid, phosphorous acid, hypophosphonic acid, diphosphorous acid, hypophosphoric acid, pyrophosphorous acid, sodium hypophosphite, potassium hypophosphite, lithium hypophosphite, calcium hypophosphite, manganese hypophosphite, magnesium hypophosphite, ammonium hypophosphite. , sodium salt of phosphorous acid, potassium salt of phosphorous acid, lithium salt of phosphorous acid, calcium salt of phosphorous acid, magnesium salt of phosphorous acid, manganese salt of phosphorous acid and ammonium salt of phosphorous acid and more preferably the acidic compound is hypophosphorous acid, phosphorous acid, sodium hypophosphite, potassium hypophosphite, manganese hypophosphite, ammonium hypophosphite, phosphorous acid sodium salt, phosphorous acid potassium salt and phosphorous acid ammonium salt. The water soluble polymer may be present in an amount of at least about 25% based on the total weight of the water soluble polymer and the stabilizer, and preferably at least about 50%. The water soluble polymer may be present in an amount of up to about 99.99%, preferably up to about 99.75%. The stabilizer may be present in an amount of at least about 0.01% based on the total weight of the water soluble polymer and the stabilizer, preferably in an amount of at least 0.25%. The stabilizer may be present in an amount of up to about -75%, preferably in an amount of up to about 15%. Additional components of the creping package may be creping release agents described in U.S. Patent 5,660,687 (Alien and Lock) the disclosure of which reference is incorporated herein by reference in its entirety. Suitable release agents include, for example, aliphatic polyols or oligomers thereof having an average number of molecular weight of less than 600, polyalkanolamines, aromatic sulfonamides, pyrrolidone, and mixtures thereof. Specific examples of the release agents include, for example, ethylene glycol; propylene glycol; diethylene glycol; glycerol; pyrrolidone; »Triethanolamine; diethanolamine; polyethylene glycol; dipropylene glycol; Uniplex 108, an aromatic sulfonamide available from Unitex Chemical Corporation, Greenville, NC. USA, and mixtures thereof. Other components of the creping pack can also be polyalkanoamide tack described in WO 99/02486, the description of which is incorporated for reference. In addition, the creping adhesive composition may contain release agents * i «P ^" afe * ft> (typically oil-based formulations) surfactants, dispersants, salts to adjust the hardness of water, acids or bases to adjust the pH of the creping adhesive composition or other useful additives The use of such adhesive formulations can provide improved product quality and better control of the papermaking process.The addition of various phosphorous or hypophosphorous acids or their salts for typical polyamidoamine-epichlorohydrin and polyamine-epichlorohydrin creping adhesive formulations have markedly improved thermooxidative stability of these materials Visual examination of samples that are subjected to high temperatures (150 or 200 ° C) for 30 minutes showed that formulations including 1 to 5% hypophosphite or phosphorous acid are much lighter in color that the control samples, the control samples acquire a very dark brown calcinated appearance The samples with added stabilizer are light yellow to golden in color. The resistance of the stabilized formulations to dimming and calcining indicates an improvement in the thermooxidative stability of the creping adhesive formulation. Thus, one could expect increased durability and stability of a creping adhesive composition containing the stabilizers of this invention, which could be expected. tfr ?? a8 &3Pßs & to result in an improved embodiment of the paper machine, and possibly improve the quality of the product. The compositions of the present invention can also be advantageous in providing improved creping embodiment 5 at higher paper machine speeds. This ability to reduce color formation in creping adhesive compositions has also been quantified by a spectrophotometric technique, which is discussed in the Examples. The composition of the present invention can be used advantageously in the creping paper process. The creping process according to the present invention may include the steps of applying the stabilizing and creping adhesive either separately or in combination, preferably combined as the creping adhesive package to a drying surface for the fibrous web, providing a fibrous web by pressing the fibrous web against the drying surface to adhere this web to the surface, and dislodging the web of the drying surface with a creping device to crease the fibrous web. The various hypophosphorous and phosphorous acids and their salts will also improve the thermooxidative stability of another synthetic, occurring naturally or polymers and modified natural water soluble copolymers Synthetically, such as polyvinyl alcohol, polyvinylamine, polyethyleneimine, polyacrylamide, polymethacrylamide, poly (acrylic acid), poly (methacrylic acid), poly (hydroxyethyl acrylate), poly (hydroxyethyl methacrylate), poly ( n-vinylpyrrolidinone), poly (ethylene oxide) [poly (ethylene glycol)], hydroxyethylcellulose (HEC), hydroxypropylcellulose (PHC), guar gum, starch, agar, chitosan, alginic acid, and carboxymethylcellulose (CMC). Other useful water-soluble polymers are the highly branched polyamidoamines and their reaction product with epichlorohydrin described in U.S. Patent 5,786,429, (Alien Case 2) the description of which reference is hereby incorporated by reference in its entirety. These polyamidoamines are preferably characterized by a highly branched structure which lacks the reactive interlayer functionality of the creping adhesive and wet strength resins in the prior art. This highly branched structure results from reacting a controlled molecular weight prepolymer - especially a prepolymer of a predetermined low molecular weight - with the required amount of epichlorohydrin or other entanglement agent. In addition, these crosslinking polyamidoamines are preferably interlocked non-thermoset polyamidoamines and blocked at the end. Also as a matter of preference, the interlaced polyamidoamines are free or substantially free of reactive interlayer functionality. The crosslinked polyamidoamines preferably comprise the reaction product of reagents including at least one dicarboxylic acid or dicarboxylic acid derivative, at least one polyamine, at least one end blocking agent, and at least one interleaver. At least one blocking agent at the end preferably comprises at least one member selected from the group consisting of monofunctional amines, monofunctional carboxylic acids, and monofunctional carboxylic acid esters. In addition, the interlacing polyamides preferably comprise the reaction product of a polyamidoamine prepolymer blocked at the end and at least one interleaver. The polyamidoamine prepolymer blocked at the end by itself preferably comprising the reaction product of at least one dicarboxylic acid or a dicarboxylic acid derivative, at least one polyamine, and at least one end-blocking agent. Also as a matter of preference, the polyamidoamine prepolymer blocked at the end is HUUglij ^ g Üi free or substantially free of amine and carboxyl end groups. Additionally, the polyamidoamine prepolymer blocked at the end preferably alternatively comprises dicarboxylic acid and polyamine, and carboxyl residues lacking end blocking and amine functionality; furthermore, the blockages at the end are blockages at the preferably amide end. The polyamidoamine prepolymer blocked at the end preferably has a DPn from about 2 to about 50 - more preferably from about 3 to about 25, and still more preferably from about 3 to about 10. Also as a preferred material, the molar ratio of at least one interlayer, to reactive amine reactive amine groups in the polyamidoamine prepolymer which blocks at the end, is between about [1 / (DPn -1)] and about 1 / (BPn-1) - Also useful as the water soluble polymers are the silyl linked polyamidoamines described in EP 0 814 108, the disclosure of which reference is incorporated herein by reference in its entirety. Preferably, the silyl-linked polyamidoamines are thermostable. Also as a matter of preference, they are soluble in an aqueous medium. These silylated polyamidoamines can comprise the reaction product of the reactants which comprise at least one dicarboxylic acid or a dicarboxylic acid derivative, at least one polyamine, and at least one silylating agent. The reagents may further comprise at least one cationizing agent, and / or at least one blocking agent at the terminus. Particularly, the silylated polyamidoamines may comprise the reaction product of at least one silylating agent, and a polyamidoamine prepolymer comprising the reaction product of at least one dicarboxylic acid or dicarboxylic acid derivative and at least one polyamine; the reagents for preparing the prepolymer may also include at least one agent that blocks at the end. Preferably, at least one silylating agent comprises at least one functionality capable of reacting with amine groups in the polyamidoamine prepolymer, and at least one hydrolysable site. Also as a preferred material, the molar ratio of at least one silylating agent to the reactive amine groups of the silylating agent in the polyamidoamine prepolymer is between about 0.05 and about 2.0. This molar ratio is more preferably between about 0.1 and about 0.75, and between about 0.15 and about 0.5 as a particular preference material.

Other possible uses of the stabilized polymers of the present invention are as improved wet strength agents for paper, in adhesive compositions, as textile fiber treatments, as dispersants, as improved dispersants and / or promoter resins in paper sizing compositions and as components of paper coating formulations. The scope of the present invention as claimed is not intended to be limited by the following Examples which are given simply by way of illustration. All parts and percentages are by weight unless otherwise indicated. Examples 1 to 36 and Comparative Examples 1 to 4 In order to test the thermooxidative stability of the resin / stabilizer formulations an accelerated aged test was performed which involved heating samples in a forced air oven and then determining their color. Aqueous solutions of polyamidoamine-epichlorohydrin Crepetrol® 80E and Kymene® 557LX resins available from Hercules Incorporated and Polyamine-epichlorohydrin resin Crepetrol® 73 available from Hercules Incorporated were mixed with candidate stabilizers and placed in aluminum weighing pans measuring 55 mm. diameter x 15 mm height. The total amount of the resin and the added stabilizer was 2.00 g. The resin formulations were dried in a forced air oven for 30 minutes at either 150 ° C or 200 ° C. After being removed from the oven the samples were stored in a desiccator until the color determinations were made. The color determination was made with a Spectrogard Color System spectrophotometer manufactured by BYK-Gardner USA. The yellowness of the samples was determined according to ASTM method D-1925-70, the standard test method for yellowness index of plastics. The yellowness index results for Crepetrol® 80E resin / stabilizer combinations are listed in Table 1. Yellowness Index results for Kymene® 557LX and Crepetrol® 73 resins in combination with stabilizers are shown in Table 2 . In addition to The hypophosphite and phosphorous acid stabilizers reduced the yellowness of all the samples significantly at the concentrations tested (1, 2.5 and 5%) and the reduction in the Yellowness Index was generally directly proportional to the amount of stabilizer added. 20 Table 1. Crepetrol® 80E Resin / Stabilizer Formulations Measurement before drying,, ^ ß8? * »Üllf áís ¡* ^ Determined by ASTMD-1925-70, Standard Test Method for Index of Yellowness of Plastics Table 2. Resins with Stabilizers Kymene® 557LX and Crepetrol®- 73 ? iTT'T? íiiiiT? friliti r iir n •? ~ wm s ég ^^ ¿íA ¿Aaa ¿¿, sts¡? Mm¡cáMZ determined by ASTMD-1925-70, Standard Test Method for Index of Yellowness of Plastics.

Claims (25)

1. An aqueous composition comprising at least one water-soluble polymer comprising a polyamidoamine-epichlorohydrin resin, polyamine-epichlorohydrin resin, polyvinyl alcohol, polyvinylamine, polyethyleneimine, polyacrylamide, polymethacrylamide, poly (acrylic acid), poly (methacrylic acid) poly (hydroxyethyl acrylate), poly (hydroxyethyl methacrylate), poly (n-vinylpyrrolidinone), poly (ethylene oxide), hydroxyethylcellulose, hydroxypropylcellulose, guar gum, starch, agar, chitosan, alginic acid, carboxymethylcellulose, highly branched polyamidoamines and its reaction product with epichlorohydrin and silyl-linked polyamidoamines; and at least one stabilizer present in an amount effective to stabilize the water soluble polymer against thermooxidative degradation, at least one stabilizer comprising hypophosphorous acid, phosphorous acid, hypodiphosphoric acid, diphosphorous acid, hypophosphoric acid, pyrophosphorous acid and salts of any of these acids.

The composition of claim 1, wherein at least one water-soluble polymer comprises at least one polyamidoamine-epichlorohydrin resin, polyamine-epichlorohydrin resin, highly branched polyamidoamines, silylated polyamidoamines, polyvinyl alcohol, polyvinylamine, polyethyleneimine, polymers of acrylamide, poly (N-vinylpyrrolidinone), hydroxyethylcellulose and carboxymethylcellulose.

The composition of claim 1, wherein at least one water-soluble polymer comprises at least one polyamidoamine-epichlorohydrin resin, polyamine-epichlorohydrin resin, highly branched polyamidoamines, silylated polyamidoamines, polyvinyl alcohol, polyvinylamine and polyethyleneimine.

The composition of any of claims 1-3, wherein at least one stabilizer comprises at least one hypophosphorous acid, phosphorous acid, hypodiphosphoric acid, diphosphorous acid, hypophosphoric acid, pyrophosphorous acid, sodium hypophosphite, potassium hypophosphite , lithium hypophosphite, calcium hypophosphite, manganese hypophosphite, magnesium hypophosphite, ammonium hypophosphite, phosphorous acid sodium salt, phosphorous acid potassium salt, phosphorous acid lithium salt, phosphorous acid calcium salt, salt magnesium of phosphorous acid, manganese salt of phosphorous acid and ammonium salt of phosphorous acid.

The composition of claim 4, wherein at least one stabilizer comprises at least one hypophosphorous acid, phosphorous acid, sodium hypophosphite, ^^ ataijwf iiM Potassium hypophosphite, manganese hypophosphite, ammonium hypophosphite, phosphorous acid sodium salt, phosphorous acid potassium salt and phosphorous acid ammonium salt.

The composition of any of claims 1-5, wherein at least one water soluble polymer is present in an amount of at least about 25% based on the total weight of at least one water soluble polymer and at least one stabilizer.

The composition of claim 6, wherein at least one water soluble polymer is present in an amount of at least about 50% based on the total weight of at least one water soluble polymer and at least one stabilizer.

The composition of any of claims 1 to 7, wherein at least one water soluble polymer is present in an amount of up to about 99.99% based on the total weight of at least one water soluble polymer and at least one stabilizer.

The composition of claim 8, wherein at least one water soluble polymer is present in an amount of up to about 99.75% based on the total weight of at least one water soluble polymer and at least one stabilizer.

10. The composition of any of the , < * * * < . It is possible to claim that at least one stabilizer is present in an amount of at least about 0.01% based on the total weight of at least one water-soluble polymer and at least one stabilizer.

11. The composition of claim 10, wherein at least one stabilizer is present in an amount of at least about 0.25% based on the total weight of at least one water soluble polymer and at least one stabilizer.

The composition of any of claims 1 to 11, wherein at least one stabilizer is present in an amount of up to about 75% based on the total weight of at least one water soluble polymer and at least one stabilizer.

The composition of claim 1, wherein at least one water soluble polymer comprises at least one poMamidoamine-epichlorohydrin resin, polyamine-epichlorohydrin resin and polyvinyl alcohol.

The composition of claim 13, wherein at least one water soluble polymer is present in an amount of at least about 25% based on the total weight of at least one water soluble polymer and at least one stabilizer.

15. The composition of claim 14, wherein at least one water-soluble polymer is present. - "jf ^ mffft ^ t ^^ -« ^ - ^^^^^^^^ - ^ - ^^^ in an amount of at least about 50% based on the total weight of at least one soluble polymer in water and at least one stabilizer 16.

The composition of claim 15, wherein at least one stabilizer is present in an amount of about 0.01 to about 75% based on the total weight of at least one soluble polymer in water and at least one stabilizer 17.

The composition of claim 16, wherein at least one stabilizer is present in an amount up to about 15% based on the total weight of at least one water soluble polymer and at least one stabilizer 18.

The composition of any of claims 14 to 17, wherein at least one water-soluble polymer comprises polyamidoamine-epichlorohydrin resin 19.

The composition of any of claims 14 to 18, wherein At least one water-soluble polymer purchased in polyamine-epichlorohydrin resin.

The composition of any of claims 14 to 19, wherein at least one water soluble polymer comprises polyvinyl alcohol.

21. A drying surface for a fibrous web that includes on a surface a creping adhesive comprising the composition of any of claims 1 to 20.

22. The drying surface according to claim 21, wherein the composition includes at least one release agent, surfactant, dispersant, bases and acids and salts other than hypophosphorous acid, phosphorous acid, hypodiphosphoric acid, diphosphorous acid, hypophosphoric acid, pyrophosphorous acid and salts thereof.

23. The creped paper forming process comprising: (a) applying at least one water-soluble polymer and stabilizer to the composition of any one of claims 1 to 20, either separately or in combination 15 a drying surface for fibrous web; (b) pressing the fibrous web against the drying surface to adhere the fibrous web to the drying surface, and (c) dislodging the fibrous web from the dried surface with a creping device to crease the fibrous web.

The process of claim 23 wherein at least one water-soluble polymer and at least one stabilizer are applied in combination to the drying surface.

25. The creped paper forming process comprising: (a) pressing the fibrous web against the drying surface of claim 21 to adhere the fibrous web to the drying surface; and (b) dislodging the fibrous web from the drying surface with a creping device to crease the fibrous web.