CA2975499A1 - Coating composition comprising hydrolysed wheat proteins - Google Patents
Coating composition comprising hydrolysed wheat proteins Download PDFInfo
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- CA2975499A1 CA2975499A1 CA2975499A CA2975499A CA2975499A1 CA 2975499 A1 CA2975499 A1 CA 2975499A1 CA 2975499 A CA2975499 A CA 2975499A CA 2975499 A CA2975499 A CA 2975499A CA 2975499 A1 CA2975499 A1 CA 2975499A1
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- wheat protein
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H19/00—Coated paper; Coating material
- D21H19/36—Coatings with pigments
- D21H19/44—Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
- D21H19/54—Starch
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/21—Macromolecular organic compounds of natural origin; Derivatives thereof
- D21H17/22—Proteins
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H19/00—Coated paper; Coating material
- D21H19/36—Coatings with pigments
- D21H19/38—Coatings with pigments characterised by the pigments
- D21H19/385—Oxides, hydroxides or carbonates
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H19/00—Coated paper; Coating material
- D21H19/36—Coatings with pigments
- D21H19/44—Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
- D21H19/50—Proteins
Abstract
La présente invention concerne une composition de couchage de papier ou de carton ayant une matière sèche comprise entre 45 et 80%, comprenant i) des liants parmi lesquels au moins un amidon modifié et un adhésif ii) une protéine de blé hydrolysée ayant une masse moléculaire moyenne comprise entre 7 et 1000kDa, et iii) une charge minérale ainsi que le procédé d'obtention d'une telle composition. L'invention concerne également un procédé de revêtement ou d'azurage de papier ou de carton comprenant les étapes consistant en i) la fourniture d'une composition selon l'invention, et au ii) dépôt ladite composition sur un substrat en papier ou en carton et le papier ou carton couché ainsi obtenu. L'invention concerne enfin l'utilisation d'une protéine de blé hydrolysée dans le remplacement du latex dans une composition de couchage de papier ou de carton.
Description
Coating composition comprising hydrolysed wheat proteins Technical field The present invention relates to a paper or cardboard coating composition comprising a modified starch and a hydrolyzed wheat protein, and also to the method for obtaining such a composition. The invention also relates to a method for coating or brightening paper or cardboard using such a composition, and to the coated paper or cardboard thus obtained. Finally, the invention relates to the use of a hydrolyzed wheat protein in the replacement of latex in a paper or cardboard coating composition.
Technical background Coating is a paper or cardboard finishing step which makes it possible to confer on a sheet of paper or on a cardboard a certain number of properties, such as opacity, gloss or whiteness or else to improve the printability for printing processes such as offset printing or photogravure. During this coating step, a composition referred to as coating color is applied to the surface of the paper or of the cardboard.
This composition generally comprises at least one minerai or pigment fluer, at least one binder and other additives such as, in particular, dispersants, rheology modifiers, lubricants, optical brighteners or antifoams.
The paper industry uses many chemical products, such as surfactants, optical brighteners, water-resistance agents (ketone resin, anionic latex, etc.), to give paper various properties or to simplify the process for obtaining same. Latex, typically synthetic latex of styrene-butadiene type, is the binder most widely used. Its function is to enable cohesion between the various elements of the composition and to bind them to the fibers. Synthetic latex is produced from petroleum resources which are by definition non-renewable. In order to reduce the number of chemical products used in this industry, and to reduce the consumption of petroleum-derived products and also the costs, the replacement of latex in coating colors represents a potential market but also a sizeable technical challenge. This is because it is very difficult to
Technical background Coating is a paper or cardboard finishing step which makes it possible to confer on a sheet of paper or on a cardboard a certain number of properties, such as opacity, gloss or whiteness or else to improve the printability for printing processes such as offset printing or photogravure. During this coating step, a composition referred to as coating color is applied to the surface of the paper or of the cardboard.
This composition generally comprises at least one minerai or pigment fluer, at least one binder and other additives such as, in particular, dispersants, rheology modifiers, lubricants, optical brighteners or antifoams.
The paper industry uses many chemical products, such as surfactants, optical brighteners, water-resistance agents (ketone resin, anionic latex, etc.), to give paper various properties or to simplify the process for obtaining same. Latex, typically synthetic latex of styrene-butadiene type, is the binder most widely used. Its function is to enable cohesion between the various elements of the composition and to bind them to the fibers. Synthetic latex is produced from petroleum resources which are by definition non-renewable. In order to reduce the number of chemical products used in this industry, and to reduce the consumption of petroleum-derived products and also the costs, the replacement of latex in coating colors represents a potential market but also a sizeable technical challenge. This is because it is very difficult to
- 2 -maintain the performance levels of a coating color while reducing the proportion of synthetic latex used.
Numerous approaches have been tested, including the use of soy proteins (US 2006/174801). However, these products resulted in the obtaining of extremely viscous coating colors or coating colors that have to be used at very low dry matter contents (about 38% to 44% DM) in order to compensate for this viscosity or to ensure dissolving of these products.
The prior art also describes the use of cold-soluble starch in such compositions; mention may for example be made of international patent application WO 08/104574. However, these starches have a tendency to form aggregates during the dissolving thereof; they also require the use of a high-shear mixer with which most paper manufacturers are not equipped.
Moreover, it should be noted that coating colors are intended to be applied to the surface of the paper or of the cardboard in very thin layers and at very high speed. Their application is carried out by means of a blade or a threaded rod which exerts very high shear forces at the surface of the paper. Thus, in the case of non-uniformity or of excess viscosity, these shear forces lead not only, at the level of the application zone, to turbulences responsible for defects in the deposit, called "filaments" or "beads", but also to an increase in the pressure exerted on the paper, increasing by the same token the risks of breakage and thus potentially hours of production interruption.
In order to solve this technical problem, the prior art proposes coating compositions which have a low dry matter content. However, the reduction of the dry matter of the composition (and thus the increase in the water content) in order to reduce the viscosity thereof is not an advantageous solution in the present application. This is because the coating color has a natural tendency to transfer into the sheet of paper ail or some of the water and of the water-soluble parts that it contains. This has several consequences, the first of which is the weakening of the paper or of the cardboard which, due to the excess water, can lose its integrity and can lead to breaking of the paper produced and thus hours of production interruption.
The second is the loss of gloss of the paper observed following the migration of the water-soluble parts of the coating color into the paper. This migration leads to a third consequence which is the weakening of the cohesion of the layer of the paper,
Numerous approaches have been tested, including the use of soy proteins (US 2006/174801). However, these products resulted in the obtaining of extremely viscous coating colors or coating colors that have to be used at very low dry matter contents (about 38% to 44% DM) in order to compensate for this viscosity or to ensure dissolving of these products.
The prior art also describes the use of cold-soluble starch in such compositions; mention may for example be made of international patent application WO 08/104574. However, these starches have a tendency to form aggregates during the dissolving thereof; they also require the use of a high-shear mixer with which most paper manufacturers are not equipped.
Moreover, it should be noted that coating colors are intended to be applied to the surface of the paper or of the cardboard in very thin layers and at very high speed. Their application is carried out by means of a blade or a threaded rod which exerts very high shear forces at the surface of the paper. Thus, in the case of non-uniformity or of excess viscosity, these shear forces lead not only, at the level of the application zone, to turbulences responsible for defects in the deposit, called "filaments" or "beads", but also to an increase in the pressure exerted on the paper, increasing by the same token the risks of breakage and thus potentially hours of production interruption.
In order to solve this technical problem, the prior art proposes coating compositions which have a low dry matter content. However, the reduction of the dry matter of the composition (and thus the increase in the water content) in order to reduce the viscosity thereof is not an advantageous solution in the present application. This is because the coating color has a natural tendency to transfer into the sheet of paper ail or some of the water and of the water-soluble parts that it contains. This has several consequences, the first of which is the weakening of the paper or of the cardboard which, due to the excess water, can lose its integrity and can lead to breaking of the paper produced and thus hours of production interruption.
The second is the loss of gloss of the paper observed following the migration of the water-soluble parts of the coating color into the paper. This migration leads to a third consequence which is the weakening of the cohesion of the layer of the paper,
- 3 -leading to problems during printing. Mention may, for example, be made of deposits of fibers or of minerai fillers originating from the coat on the blankets during offset printing. The final consequence of this excess water of the coating composition is the increase in energy and/or in time required to dry the paper or the cardboard obtained.
In addition, the advantage of a coating color which has both a high dry matter content and a low viscosity, beyond the solving of the abovementioned problems, is the small amount of coating color that needs to be laid. In addition, a coating color of low viscosity would also have the advantage of allowing very-high-speed coating, which constitutes a very clear industrial advantage.
Moreover, among the approaches envisioned in the replacement of latex, none makes it possible to improve or at the very least maintain the pick resistance capacities of the paper or cardboard obtained. In point of fact, a strong pick resistance guarantees preservation of the integrity of the paper or cardboard when a force is exerted at its surface and thus a wider use of the latter. This property is essential in printing, in particular offset printing where the paper is subjected to high stresses at the output of the inking rollers. This is because, in this step, the film of ink separates into 2 parts, one remaining on the paper and the other on the blanket.
During this separation, a normal force is exerted on the paper leading to picking of the particles (minerai fillers or fibers) poorly bonded to one another or to the paper and the depositing thereof on the blankets. This phenomenon is responsible for the fouling of the blankets and can make it necessary for the printer to interrupt production in order to clean them.
There is therefore currently no coating composition which has both a reduced latex content beyond what the prior art describes, a very high dry matter content and a low viscosity while at the same time conferring a high pick resistance on the paper or cardboard obtained.
it is thus the object of the present invention to provide a coating color corresponding to the needs of the prior art.
In addition, the advantage of a coating color which has both a high dry matter content and a low viscosity, beyond the solving of the abovementioned problems, is the small amount of coating color that needs to be laid. In addition, a coating color of low viscosity would also have the advantage of allowing very-high-speed coating, which constitutes a very clear industrial advantage.
Moreover, among the approaches envisioned in the replacement of latex, none makes it possible to improve or at the very least maintain the pick resistance capacities of the paper or cardboard obtained. In point of fact, a strong pick resistance guarantees preservation of the integrity of the paper or cardboard when a force is exerted at its surface and thus a wider use of the latter. This property is essential in printing, in particular offset printing where the paper is subjected to high stresses at the output of the inking rollers. This is because, in this step, the film of ink separates into 2 parts, one remaining on the paper and the other on the blanket.
During this separation, a normal force is exerted on the paper leading to picking of the particles (minerai fillers or fibers) poorly bonded to one another or to the paper and the depositing thereof on the blankets. This phenomenon is responsible for the fouling of the blankets and can make it necessary for the printer to interrupt production in order to clean them.
There is therefore currently no coating composition which has both a reduced latex content beyond what the prior art describes, a very high dry matter content and a low viscosity while at the same time conferring a high pick resistance on the paper or cardboard obtained.
it is thus the object of the present invention to provide a coating color corresponding to the needs of the prior art.
- 4 -Detailed description of the invention The invention relates to a paper or cardboard coating composition having a dry matter content of between 45% and 80%, preferentially 50% and 78%, more preferentially 55% and 75%, comprising:
= binders which include at least one modified starch and one preferentially synthetic adhesive, = a hydrolyzed wheat protein having an average molecular weight of between and 1000 kDa, and = a minerai The term "paper or cardboard coating composition" is intended to mean a composition that is particularly suitable for coating paper or cardboard. It is an aqueous formulation conventionally containing water, at least one minerai filler, one or more binders and also various additives.
Typically, the composition according to the invention comprises, in parts per 100 parts by weight of minerai fluer:
- 1 to 99 parts of binders, preferentially 1 to 50 parts, more preferentially 1 to 15 parts, and - 1 to 50 parts by weight of wheat protein, preferentially 1 to 20 parts, more preferentially 1 to 8 parts.
The term "wheat protein" denotes a water-insoluble protein fraction extracted from wheat four via the wet process and subsequently dried, also known as wheat gluten. Typically, wheat proteins having an average molecular weight of between 7 and 1000 kDa are obtained by hydrolysis according to methods known well to those skilled in the art [Anfinsen, C.B. Jr. (1965), Advances in Protein Chemistry.. y. 20, New York and London, Academic Press]. Typically, the hydrolysis may be thermal, acid or enzymatic. Enzymatic hydrolysis is preferred.
A wheat gluten that is particularly suitable for the present invention is Solprog 508 sold by Tereos Syral.
= binders which include at least one modified starch and one preferentially synthetic adhesive, = a hydrolyzed wheat protein having an average molecular weight of between and 1000 kDa, and = a minerai The term "paper or cardboard coating composition" is intended to mean a composition that is particularly suitable for coating paper or cardboard. It is an aqueous formulation conventionally containing water, at least one minerai filler, one or more binders and also various additives.
Typically, the composition according to the invention comprises, in parts per 100 parts by weight of minerai fluer:
- 1 to 99 parts of binders, preferentially 1 to 50 parts, more preferentially 1 to 15 parts, and - 1 to 50 parts by weight of wheat protein, preferentially 1 to 20 parts, more preferentially 1 to 8 parts.
The term "wheat protein" denotes a water-insoluble protein fraction extracted from wheat four via the wet process and subsequently dried, also known as wheat gluten. Typically, wheat proteins having an average molecular weight of between 7 and 1000 kDa are obtained by hydrolysis according to methods known well to those skilled in the art [Anfinsen, C.B. Jr. (1965), Advances in Protein Chemistry.. y. 20, New York and London, Academic Press]. Typically, the hydrolysis may be thermal, acid or enzymatic. Enzymatic hydrolysis is preferred.
A wheat gluten that is particularly suitable for the present invention is Solprog 508 sold by Tereos Syral.
- 5 -Typically, the hydrolyzed wheat protein according to the invention has a weight-average molecular weight of between 7 and 800 kDa, 5 and 500 kDa or 8 and 100 kDa, preferentially between 9 and 80 kDa, more preferentially between 10 and 70 kDa, even more preferentially between 12 and 50 kDa, even more preferentially between 13 and 40 kDa.
The term "binder" is intended to mean a compound having the function of sticking the particles of minerai fluer (or pigments) to one another and of maintaining the coat at the surface of the paper.
According to the invention, the composition comprises a binders/wheat protein ratio of from 1:5 to 5:1, preferentially from 1:3 to 3:1, more preferentially 1:2 to 2:1.
According to the present invention, the binders are at least one modified starch and one adhesive such as a synthetic adhesive; typically in a modified starch/synthetic adhesive ratio of from 1:5 to 5:1, preferentially from 1:3 to 3:1, more preferentially 1:2 to 2:1.
For the purposes of the present invention, the term "modified starch" is intended to mean any starch that has been chemically or physically treated.
The molecules of modified starches present in the present invention can originate from a plant source such as cereals, tubers, roots, vegetables and fruits.
Thus, the starch(es) can originate from a plant source chosen from corn, peas, potato, sweet potato, banana, barley, wheat, rice, oats, sago, tapioca and sorghum.
More particularly, the modification reactions can be carried out for example:
= by pregelatinization by causing the starch granules to burst (for example drying and cooking in a drying drum);
= by acid hydrolysis using for example strong acids or by enzymatic hydrolysis;
= by oxidation using for example strong oxidizing agents resulting in the introduction of carboxyl groups into the starch molecule and in the
The term "binder" is intended to mean a compound having the function of sticking the particles of minerai fluer (or pigments) to one another and of maintaining the coat at the surface of the paper.
According to the invention, the composition comprises a binders/wheat protein ratio of from 1:5 to 5:1, preferentially from 1:3 to 3:1, more preferentially 1:2 to 2:1.
According to the present invention, the binders are at least one modified starch and one adhesive such as a synthetic adhesive; typically in a modified starch/synthetic adhesive ratio of from 1:5 to 5:1, preferentially from 1:3 to 3:1, more preferentially 1:2 to 2:1.
For the purposes of the present invention, the term "modified starch" is intended to mean any starch that has been chemically or physically treated.
The molecules of modified starches present in the present invention can originate from a plant source such as cereals, tubers, roots, vegetables and fruits.
Thus, the starch(es) can originate from a plant source chosen from corn, peas, potato, sweet potato, banana, barley, wheat, rice, oats, sago, tapioca and sorghum.
More particularly, the modification reactions can be carried out for example:
= by pregelatinization by causing the starch granules to burst (for example drying and cooking in a drying drum);
= by acid hydrolysis using for example strong acids or by enzymatic hydrolysis;
= by oxidation using for example strong oxidizing agents resulting in the introduction of carboxyl groups into the starch molecule and in the
- 6 -depolymerization of the starch molecule (for example by treating an aqueous starch solution with sodium hypochlorite);
= by crosslinking with functional agents capable of reacting with the hydroxyl groups of the starch molecules which will thus be bonded to one another (for example with glyceryl and/or phosphate groups); phosphorus-containing compounds of monostarch phosphates (of the St-O-P0-(0X)2 type), of distarch phosphates (of the St-O-P0-(0X)-0-St type) or even of tristarch phosphates (of the St-O-P0-(0-St)2 type) or mixtures thereof are for example obtained. X
denotes for example alkali or alkaline earth metals;
= by esterification in an alkaline medium for the grafting of functional groups, in particular C1-C6 acyl (acetyl), C1-C6 hydroxyalkyl (hydroxyethyl, hydroxypropyl), carboxymethyl or octenylsuccinic groups. Mention may in particular be made of sodium carboxymethyl-modified starches;
= by dextrinization, such as for example by a dry-phase treatment of a native starch, by the action of heat, in an optionally dry medium, optionally in the presence of a chemical agent, by the action of heat or a combination of these various means. Most of these methods, whether they are batchwise or continuous, call for transformation temperatures higher than 80 C and for the optional presence of an acid, of an alkaline agent and/or of an oxidizing agent.
Suitable modified starches comprise, but are flot limited to, pregelatinized starches, low-viscosity starches (for example, dextrins, hydrolyzed starches, oxidized starches), stabilized starches (for example, starch esters, starch ethers), crosslinked starches and starches which have received a combination of treatments (for example crosslinking and gelatinization treatments) and mixtures thereof.
Dextrins are the preferred modified starches. For the purposes of the present invention, the term "dextrin" is intended to mean a modified starch obtained from native starch by dextrinization; typically, the dextrins according to the invention are flot subjected to any other modification, in particular chemical modification.
The
= by crosslinking with functional agents capable of reacting with the hydroxyl groups of the starch molecules which will thus be bonded to one another (for example with glyceryl and/or phosphate groups); phosphorus-containing compounds of monostarch phosphates (of the St-O-P0-(0X)2 type), of distarch phosphates (of the St-O-P0-(0X)-0-St type) or even of tristarch phosphates (of the St-O-P0-(0-St)2 type) or mixtures thereof are for example obtained. X
denotes for example alkali or alkaline earth metals;
= by esterification in an alkaline medium for the grafting of functional groups, in particular C1-C6 acyl (acetyl), C1-C6 hydroxyalkyl (hydroxyethyl, hydroxypropyl), carboxymethyl or octenylsuccinic groups. Mention may in particular be made of sodium carboxymethyl-modified starches;
= by dextrinization, such as for example by a dry-phase treatment of a native starch, by the action of heat, in an optionally dry medium, optionally in the presence of a chemical agent, by the action of heat or a combination of these various means. Most of these methods, whether they are batchwise or continuous, call for transformation temperatures higher than 80 C and for the optional presence of an acid, of an alkaline agent and/or of an oxidizing agent.
Suitable modified starches comprise, but are flot limited to, pregelatinized starches, low-viscosity starches (for example, dextrins, hydrolyzed starches, oxidized starches), stabilized starches (for example, starch esters, starch ethers), crosslinked starches and starches which have received a combination of treatments (for example crosslinking and gelatinization treatments) and mixtures thereof.
Dextrins are the preferred modified starches. For the purposes of the present invention, the term "dextrin" is intended to mean a modified starch obtained from native starch by dextrinization; typically, the dextrins according to the invention are flot subjected to any other modification, in particular chemical modification.
The
- 7 -dextrins that are suitable for the present invention are, for example, white dextrins, generally obtained by transformation of starch at temperatures often of between 100 and 170 C, in the presence of a chemical agent or chemical agents, in particular of acid, in relatively high amounts; yellow dextrins, often obtained by transformation of starch at higher temperatures, generally of between 170 and 230 C, in the presence of a chemical agent or chemical agents, in particular of acid; finally, dextrins termed "British Gum" obtained solely by the action of heat, at high temperature, often above 230 C. A dextrin that is particularly suitable for the present invention is a wheat-based dextrin, typically the Mylofilm 214 or Mylofilm 218 dextrin sold by the company Tereos Syral.
Typically, in the context of the present invention, the particularly suitable modified starch has a weight-average molecular weight of between 20 and 300 kDa, preferentially 30 and 250 kDa, more preferentially between 35 and 233 kDa, even more preferentially between 40 and 200 kDa, even more preferentially between and 150 kDa, and/or a viscosity of between 50 and 400 mPa.s (Brookfield, 70 C, 31% DM). The measurement, with a Brookfield viscometer, of the modified starch, such as, for example, of a dextrin, is performed in solution and is carried out on an RVDV-E model, the measurement is carried out at a speed of 20 rpm with spindle 3.
The measurements are carried out at 70 C. The module is dipped in a composition of modified starch in suspension at 31% of dry matter up to the indicator une of the spindle; the value is recorded after 10 s of rotation.
The term "average molecular weight" is intended to mean the weight-average molecular weight.
In the context of the hydrolyzed protein, this average molecular weight is measured by size exclusion chromatography (SE-11PLC) coupled with a UV
detector regulated at the wavelength of 214 nm. The size exclusion chromatograph is equipped with a pump which circulates an eluent composed of a PBS phosphate buffer (0.1 M Na2HPO4-Nal-12PO4 with 0.1% of SDS) at a flow rate of 0.7 ml/min in a TSKG4000SWx1 column. This measurement is expressed in daltons. The
Typically, in the context of the present invention, the particularly suitable modified starch has a weight-average molecular weight of between 20 and 300 kDa, preferentially 30 and 250 kDa, more preferentially between 35 and 233 kDa, even more preferentially between 40 and 200 kDa, even more preferentially between and 150 kDa, and/or a viscosity of between 50 and 400 mPa.s (Brookfield, 70 C, 31% DM). The measurement, with a Brookfield viscometer, of the modified starch, such as, for example, of a dextrin, is performed in solution and is carried out on an RVDV-E model, the measurement is carried out at a speed of 20 rpm with spindle 3.
The measurements are carried out at 70 C. The module is dipped in a composition of modified starch in suspension at 31% of dry matter up to the indicator une of the spindle; the value is recorded after 10 s of rotation.
The term "average molecular weight" is intended to mean the weight-average molecular weight.
In the context of the hydrolyzed protein, this average molecular weight is measured by size exclusion chromatography (SE-11PLC) coupled with a UV
detector regulated at the wavelength of 214 nm. The size exclusion chromatograph is equipped with a pump which circulates an eluent composed of a PBS phosphate buffer (0.1 M Na2HPO4-Nal-12PO4 with 0.1% of SDS) at a flow rate of 0.7 ml/min in a TSKG4000SWx1 column. This measurement is expressed in daltons. The
- 8 -preparation of a sample can be carried out by dissolving the product studied in a phosphate extraction buffer with 1% of SDS, followed by centrifugation to recover the supernatant.
In the context of the modified starch and more particularly of dextrin, the average molecular weight is expressed in daltons and can be determined by those skilled in the art by size exclusion chromatography coupled with a detector of MALLS (Multi Angle Laser Light Scattering) type. The preparation of a sample can be carried out by dissolving 50 mg by dry weight of a modified starch and in particular of dextrin in a solvent consisting of a mixture of 90% (v/v) of DMSO
(dimethyl sulfoxide) in deionized water containing 0.1% (w/v) of sodium nitrate.
After stirring overnight, the mixture is preheated for 1 hour at 105 C and then centrifuged for 15 min at 5300 g. A volume of 100 ml of the supernatant is injected into a size exclusion chromatography apparatus, the mobile phase of which is for example composed of a mixture of 90% (v/v) of DMSO (dimethyl sulfoxide) in deionized water containing 0.1% (w/v) of sodium nitrate, at a flow rate of 0.5 ml/min and a temperature of 70 C, the columns used preferentially being a combination in series of Gram columns. The detector is for example an angle laser such as the New Generation 3-angle miniDawn Treos. The calibration is carried out with Viscotec P82 Shodex standards. In the context of the present invention, the adhesive is preferentially synthetic. An example of synthetic adhesive suitable for the present invention is a latex, a vinyl acetate, polyvinyl alcohol, sodium carboxymethylcellulose and hydroxyethylcellulose.
The term "latex" refers to an aqueous dispersion of polymer which corresponds to a colloidal dispersion of synthetic polymers in an aqueous phase, i.e.
a dispersion of polymer microparticles in suspension in an aqueous phase, sometimes also referred to as polymer suspension or polymer emulsion. Examples of latex suitable for the present invention are chosen from the group made up of styrene-butadiene latexes, polyvinyl alcohol latexes and acrylic copolymer latexes, preferentially latex of styrene-butadiene type.
In the context of the modified starch and more particularly of dextrin, the average molecular weight is expressed in daltons and can be determined by those skilled in the art by size exclusion chromatography coupled with a detector of MALLS (Multi Angle Laser Light Scattering) type. The preparation of a sample can be carried out by dissolving 50 mg by dry weight of a modified starch and in particular of dextrin in a solvent consisting of a mixture of 90% (v/v) of DMSO
(dimethyl sulfoxide) in deionized water containing 0.1% (w/v) of sodium nitrate.
After stirring overnight, the mixture is preheated for 1 hour at 105 C and then centrifuged for 15 min at 5300 g. A volume of 100 ml of the supernatant is injected into a size exclusion chromatography apparatus, the mobile phase of which is for example composed of a mixture of 90% (v/v) of DMSO (dimethyl sulfoxide) in deionized water containing 0.1% (w/v) of sodium nitrate, at a flow rate of 0.5 ml/min and a temperature of 70 C, the columns used preferentially being a combination in series of Gram columns. The detector is for example an angle laser such as the New Generation 3-angle miniDawn Treos. The calibration is carried out with Viscotec P82 Shodex standards. In the context of the present invention, the adhesive is preferentially synthetic. An example of synthetic adhesive suitable for the present invention is a latex, a vinyl acetate, polyvinyl alcohol, sodium carboxymethylcellulose and hydroxyethylcellulose.
The term "latex" refers to an aqueous dispersion of polymer which corresponds to a colloidal dispersion of synthetic polymers in an aqueous phase, i.e.
a dispersion of polymer microparticles in suspension in an aqueous phase, sometimes also referred to as polymer suspension or polymer emulsion. Examples of latex suitable for the present invention are chosen from the group made up of styrene-butadiene latexes, polyvinyl alcohol latexes and acrylic copolymer latexes, preferentially latex of styrene-butadiene type.
- 9 -In general in the coating color, the minerai filler introduced is carried in the form of an aqueous suspension. Conventionally, this filler is a calcium carbonate suspended in water by means of a dispersing agent. Typically, a minerai filler that is particularly suitable for a coating composition comprises a sufficient degree of whiteness (greater than 80% of the whiteness of barium sulfate at 457 nm), a particle size distribution of from 0 to 10 1.1m at most (the average particle size being between 0.2 and 2 itm) and a minimum degree of agglomeration of the particles. For example, the minerai fluer can be chosen from the group made up of calcium carbonates, coating clay, calcined fine clay, alumina trihydrate, talc and titanium dioxide.
The term "calcium carbonate" comprises ground calcium carbonate (GCC), that is to say a calcium carbonate obtained from natural sources, such as limestone, marble, calcite or lime. The term "calcium carbonate" also comprises precipitated calcium carbonate (PCC), that is to say a synthesized substance, generally obtained by precipitation following a reaction of carbon dioxide and calcium hydroxide (hydrated lime) in an aqueous environment or by precipitation of a source of calcium and of carbonate in water.
The composition according to the invention may also comprise other agents such as one or more dispersing agents. The term "dispersing agent" is intended to mean an agent having the function of maintaining the particles of minerai fluer in a state of electrostatic dispersion. By way of example, the dispersing agent is chosen from the group made up of sodium polyacrylate, tetrasodium polyphosphate, tetrasodium pyrophosphate, pentasodium tripolyphosphate, sodium tetraphosphate and sodium silicate.
The composition may also comprise at least one lubricant, typically chosen from the group made up of sodium stearate, calcium stearate, sulfonated oils, sulfated tall ou l fatty acid and polyethylene emulsions.
The composition may also comprise at least one insolubilizing agent chosen from the group made up of urea resins, melamine resins, glyoxal, zinc compounds, formaldehyde and dimethylolurea.
The term "calcium carbonate" comprises ground calcium carbonate (GCC), that is to say a calcium carbonate obtained from natural sources, such as limestone, marble, calcite or lime. The term "calcium carbonate" also comprises precipitated calcium carbonate (PCC), that is to say a synthesized substance, generally obtained by precipitation following a reaction of carbon dioxide and calcium hydroxide (hydrated lime) in an aqueous environment or by precipitation of a source of calcium and of carbonate in water.
The composition according to the invention may also comprise other agents such as one or more dispersing agents. The term "dispersing agent" is intended to mean an agent having the function of maintaining the particles of minerai fluer in a state of electrostatic dispersion. By way of example, the dispersing agent is chosen from the group made up of sodium polyacrylate, tetrasodium polyphosphate, tetrasodium pyrophosphate, pentasodium tripolyphosphate, sodium tetraphosphate and sodium silicate.
The composition may also comprise at least one lubricant, typically chosen from the group made up of sodium stearate, calcium stearate, sulfonated oils, sulfated tall ou l fatty acid and polyethylene emulsions.
The composition may also comprise at least one insolubilizing agent chosen from the group made up of urea resins, melamine resins, glyoxal, zinc compounds, formaldehyde and dimethylolurea.
- 10 -The invention also relates to a method for producing the composition according to the invention, comprising the following steps:
- mixing, with stirring, a minerai rifler and binders which include at least one modified starch, preferentially a dextrin, and one preferentially synthetic adhesive, said modified starch preferentially having previously undergone a cooking step, - adding, with stirring, to the mixture obtained, a hydrolyzed wheat protein having an average molecular weight of between 7 and 1000 kDa, said hydrolyzed wheat protein preferentially being in a pulverulent form, - adding water, with stirring, so as to obtain a composition having a dry matter content of between 45% and 80%; optionally, the adding of water is carried out with the minerai fluer and/or the modified starch and/or the hydrolyzed protein.
Typically, during the method for producing the composition according to the invention, said modified starch such as in particular a dextrin can be dissolved in the water, and can preferentially undergo a cooking step, prior to it being mixed with the adhesive. Independently, the minerai tiller can be dissolved beforehand in the water before being mixed with the binders.
The invention also relates to a method for coating or brightening paper or cardboard, said method comprising the steps consisting of (a) the provision of a composition according to the invention, (b) the depositing of said composition on a paper or cardboard substrate.
The step of depositing said composition on a paper or cardboard substrate can be carried out by means of blade coating, pencil coating, a threaded rod, size press curtain coating or a film press or any other technique known to those skilled in the art. Typically, the depositing step is carried out at a temperature of between 25 and 60 C.
- mixing, with stirring, a minerai rifler and binders which include at least one modified starch, preferentially a dextrin, and one preferentially synthetic adhesive, said modified starch preferentially having previously undergone a cooking step, - adding, with stirring, to the mixture obtained, a hydrolyzed wheat protein having an average molecular weight of between 7 and 1000 kDa, said hydrolyzed wheat protein preferentially being in a pulverulent form, - adding water, with stirring, so as to obtain a composition having a dry matter content of between 45% and 80%; optionally, the adding of water is carried out with the minerai fluer and/or the modified starch and/or the hydrolyzed protein.
Typically, during the method for producing the composition according to the invention, said modified starch such as in particular a dextrin can be dissolved in the water, and can preferentially undergo a cooking step, prior to it being mixed with the adhesive. Independently, the minerai tiller can be dissolved beforehand in the water before being mixed with the binders.
The invention also relates to a method for coating or brightening paper or cardboard, said method comprising the steps consisting of (a) the provision of a composition according to the invention, (b) the depositing of said composition on a paper or cardboard substrate.
The step of depositing said composition on a paper or cardboard substrate can be carried out by means of blade coating, pencil coating, a threaded rod, size press curtain coating or a film press or any other technique known to those skilled in the art. Typically, the depositing step is carried out at a temperature of between 25 and 60 C.
- 11 -Typically, said composition is applied to at least one face of said paper or cardboard substrate in an amount of between 3 g/m2 and 15 g/m2, preferably between g/m2 and 10 g/m2.
The invention also relates to a paper or cardboard coated with the 5 composition according to the invention.
The invention also relates to the use of a hydrolyzed wheat protein in the replacement of latex in a paper or cardboard coating composition, said hydrolyzed wheat protein preferentially having an average molecular weight of between 7 and 1000 kDa.
The invention relates to the use of a combination of a hydrolyzed wheat protein and of a modified starch, and more particularly a dextrin, in the replacement of latex, preferentially in a modified starch/wheat protein ratio of 1:5 to 5:1, preferentially of 1:3 to 3:1, more preferentially 1:2 to 2:1.
Typically, said wheat protein or said combination of wheat protein with a modified starch, preferentially a dextrin, is used in the replacement of from 1% to 40% of the latex of said composition, preferentially from 10% to 35%, more preferentially from 15% to 30%.
Although they have distinct meanings, the terms "comprising", "containing"
and "consisting of' have been used interchangeably in the description of the invention, and can be replaced by one another.
The invention will be understood more clearly on reading the following examples given only by way of illustration.
Examples Example 1: Replacement of latex by a modified starch Production of coating colors:
The invention also relates to a paper or cardboard coated with the 5 composition according to the invention.
The invention also relates to the use of a hydrolyzed wheat protein in the replacement of latex in a paper or cardboard coating composition, said hydrolyzed wheat protein preferentially having an average molecular weight of between 7 and 1000 kDa.
The invention relates to the use of a combination of a hydrolyzed wheat protein and of a modified starch, and more particularly a dextrin, in the replacement of latex, preferentially in a modified starch/wheat protein ratio of 1:5 to 5:1, preferentially of 1:3 to 3:1, more preferentially 1:2 to 2:1.
Typically, said wheat protein or said combination of wheat protein with a modified starch, preferentially a dextrin, is used in the replacement of from 1% to 40% of the latex of said composition, preferentially from 10% to 35%, more preferentially from 15% to 30%.
Although they have distinct meanings, the terms "comprising", "containing"
and "consisting of' have been used interchangeably in the description of the invention, and can be replaced by one another.
The invention will be understood more clearly on reading the following examples given only by way of illustration.
Examples Example 1: Replacement of latex by a modified starch Production of coating colors:
- 12 -Preliminary tests showed that the best results were obtained with a dry matter content greater than 45% (machinability and energy yield). A clearer improvement is observed from 60%. Indeed, an increase in the breaking of the paper when the coating color is diluted (less than 45% of DM) was noted. Furthermore, an increase was noted in the drying time below 60% and even more below 45%, which appears to be the lowest acceptable dry matter content. Since the paper undergoes a drying step after coating, any excess water in the coating color results in an increase in the drying times and thus in the production cost. Consequently, the tests were continued with coating colors having a dry matter content of 70%.
A coating color was produced according to formulae R1 to R4 of table 1 below.
Calcium Synthetic Dextrin carbonate binder RI 100 3.5 3.5 R3 100 2.5 4.5 Table 1: Coating compositions cornprising dextrin as partial replacement for latex The recipes are given in number of parts (as is standard practice in papermaking).
The dextrin (Mylofilm0 214) is a wheat-based dextrin (Mw = 47 kDa, Wt = 11.6) sold by Tereos Syral. It is first of ail cooked at a concentration of 35%
dry matter on a jet cooker (Temp. = 130 C, residence time: 3 min), then diluted to 31%.
A coating color was produced according to formulae R1 to R4 of table 1 below.
Calcium Synthetic Dextrin carbonate binder RI 100 3.5 3.5 R3 100 2.5 4.5 Table 1: Coating compositions cornprising dextrin as partial replacement for latex The recipes are given in number of parts (as is standard practice in papermaking).
The dextrin (Mylofilm0 214) is a wheat-based dextrin (Mw = 47 kDa, Wt = 11.6) sold by Tereos Syral. It is first of ail cooked at a concentration of 35%
dry matter on a jet cooker (Temp. = 130 C, residence time: 3 min), then diluted to 31%.
- 13 -The coating color is produced using a stirrer (IKA type) first of ail by suspending the calcium carbonate in water at 79.7% (Hydrocarb 90 supplied by the company Omya). The synthetic binder (styrene-butadiene DL930 latex from the company Styron) and also the dextrin dissolved as previously specified are then added to the calcium carbonate. The concentration is adjusted with water in order to obtain a dry matter content of 70%. The stirring speed is adjusted to 1500 rpm; the pH is then adjusted to 9. The coating color is thus stirred for 10 min.
The coating colors of table 1 were tested in coating tests.
The viscosity of the coating colors is evaluated before coating of the paper.
Brookfield viscosity The measurement of the coating color with a Brookfield viscometer is carried out on an RVDV-E model; the measurement is carried out at a speed of 20 rpm with spindle 3. The measurements are carried out at 40 C. The module is dipped in the coating color up to the indicator une of the spindle, and the value is recorded after 10 s of rotation.
Paper coating The coating color is deposited on the paper in an amount of 6 g/m2 on a single face using a DT blade coater coating pilot plant allowing drying combining infrared radiation and hot air. The coating speed is 20 m/min.
The paper used is an 80 g/m2 thin paper supplied by the company Fedrigoni.
The paper thus coated is then stored in a humidity- and temperature-conditioned room (50% humidity, 23 C) for 24 h before any test.
The coating colors of table 1 were tested in coating tests.
The viscosity of the coating colors is evaluated before coating of the paper.
Brookfield viscosity The measurement of the coating color with a Brookfield viscometer is carried out on an RVDV-E model; the measurement is carried out at a speed of 20 rpm with spindle 3. The measurements are carried out at 40 C. The module is dipped in the coating color up to the indicator une of the spindle, and the value is recorded after 10 s of rotation.
Paper coating The coating color is deposited on the paper in an amount of 6 g/m2 on a single face using a DT blade coater coating pilot plant allowing drying combining infrared radiation and hot air. The coating speed is 20 m/min.
The paper used is an 80 g/m2 thin paper supplied by the company Fedrigoni.
The paper thus coated is then stored in a humidity- and temperature-conditioned room (50% humidity, 23 C) for 24 h before any test.
- 14 -Dry IGT pick resistance The dry pick measurement is carried out according to the IGT W31 method (ISO 3783:2006). This measurement makes it possible to evaluate the strength of the layer. Indeed, the binders (synthetic or natural such as starch) are used to maintain the minerai fillers required for the paper printing properties. If the binding capacity is too low, the minerai fillers are picked from the paper during printing and are deposited on the inking roll, leading to frequent interruptions. The higher the dry IGT
measurement, the higher the pick resistance of the layer.
Results The analysis of the characteristics of the paper obtained made it possible to demonstrate that replacing the latex with dextrin in solution leads to a loss of the pick properties (table 2).
Brookfield Dry pick viscosity (m/s) (mPa.$) R1 125 0.45 R2 140 0.40 R3 145 0.37 R4 155 0.19 Table 2: Brookfield viscosity of the coating compositions RI to R4 and pick properties of the papers obtained In fact, replacing the latex with dextrin alone does flot make it possible to maintain the characteristics of the coating and thus leads to a clear decrease in the
measurement, the higher the pick resistance of the layer.
Results The analysis of the characteristics of the paper obtained made it possible to demonstrate that replacing the latex with dextrin in solution leads to a loss of the pick properties (table 2).
Brookfield Dry pick viscosity (m/s) (mPa.$) R1 125 0.45 R2 140 0.40 R3 145 0.37 R4 155 0.19 Table 2: Brookfield viscosity of the coating compositions RI to R4 and pick properties of the papers obtained In fact, replacing the latex with dextrin alone does flot make it possible to maintain the characteristics of the coating and thus leads to a clear decrease in the
- 15 -pick properties of the layer. Thus, dextrin alone does flot make it possible to compensate for the reduction in latex in the coating color.
Example 2: Replacement of latex with hydrolyzed soy or wheat proteins The use of plant proteins as a replacement for latex was evaluated. After several tests, it was noted that the addition of proteins in addition to the dextrin makes it possible to observe better results in the replacement of latex than those observed for the dextrin alone, more particularly regarding the dry pick properties of the composition obtained. This effect was observed only for hydrolyzed proteins, not for native proteins. Thus, nonhydrolyzed wheat gluten, because of its low solubility, does flot make it possible to obtain uniform coating colors of acceptable viscosity, and even less so the replacement of latex. In order to evaluate the effect of replacing the latex with hydrolyzed proteins of various botanical origins, the R1 mixture was chosen as reference recipe for a coating color.
The coating colors were produced as in example 1 according to the formulae of table 3 in which the synthetic latex is replaced with proteins in an amount of 14%
(R5), 30% (R6) and 43% (R7).
Calcium Synthetic Dextrin Protein carbonate binder RI 100 3.5 3.5 R5 100 3 3.5 0.5 R6 100 2.5 3.5 1 R7 100 2 3.5 1.5 Table 3: Coating compositions comprising dextrin and proteins as partial replacement for latex
Example 2: Replacement of latex with hydrolyzed soy or wheat proteins The use of plant proteins as a replacement for latex was evaluated. After several tests, it was noted that the addition of proteins in addition to the dextrin makes it possible to observe better results in the replacement of latex than those observed for the dextrin alone, more particularly regarding the dry pick properties of the composition obtained. This effect was observed only for hydrolyzed proteins, not for native proteins. Thus, nonhydrolyzed wheat gluten, because of its low solubility, does flot make it possible to obtain uniform coating colors of acceptable viscosity, and even less so the replacement of latex. In order to evaluate the effect of replacing the latex with hydrolyzed proteins of various botanical origins, the R1 mixture was chosen as reference recipe for a coating color.
The coating colors were produced as in example 1 according to the formulae of table 3 in which the synthetic latex is replaced with proteins in an amount of 14%
(R5), 30% (R6) and 43% (R7).
Calcium Synthetic Dextrin Protein carbonate binder RI 100 3.5 3.5 R5 100 3 3.5 0.5 R6 100 2.5 3.5 1 R7 100 2 3.5 1.5 Table 3: Coating compositions comprising dextrin and proteins as partial replacement for latex
- 16 -In order to reduce the amounts of latex in the coating compositions, hydrolyzed wheat and soy proteins were tested on the basis of the proportions provided in table 3.
The proteins tested are the following:
- hydrolyzed wheat proteins having a low molecular weight (Mw = 5.7 kDa), - hydrolyzed wheat proteins having a medium molecular weight of 15.5 kDa (Solpro 508 sold by Tereos Syral) and - hydrolyzed soy protein (Sobind LVL from DuPont).
The proteins are added to the coating color without prior dilution.
The coating color is produced as in example 1, using a stirrer (IKA type), by suspending the calcium carbonate in water at 79.7% (Hydrocarb 90 supplied by the company Omya). The synthetic binder (styrene-butadiene DL930 latex from the company Styron) and also the dextrin having been dissolved are then added to the calcium carbonate as previously specified. In this step, the protein is incorporated into the color in solution form or as powder, as appropriate. The concentration is adjusted with water in order to obtain a dry matter content of 70%. The stirring speed is adjusted to 1500 rpm; the pH is then adjusted to 9. The coating color is thus stirred for 10 min.
The proteins tested are the following:
- hydrolyzed wheat proteins having a low molecular weight (Mw = 5.7 kDa), - hydrolyzed wheat proteins having a medium molecular weight of 15.5 kDa (Solpro 508 sold by Tereos Syral) and - hydrolyzed soy protein (Sobind LVL from DuPont).
The proteins are added to the coating color without prior dilution.
The coating color is produced as in example 1, using a stirrer (IKA type), by suspending the calcium carbonate in water at 79.7% (Hydrocarb 90 supplied by the company Omya). The synthetic binder (styrene-butadiene DL930 latex from the company Styron) and also the dextrin having been dissolved are then added to the calcium carbonate as previously specified. In this step, the protein is incorporated into the color in solution form or as powder, as appropriate. The concentration is adjusted with water in order to obtain a dry matter content of 70%. The stirring speed is adjusted to 1500 rpm; the pH is then adjusted to 9. The coating color is thus stirred for 10 min.
- 17 -Hydrolyzed soy proteins Hydrolyzed wheat proteins Low molecular weight Medium molecular weight (Mw = 5.7 kDa) (Mw = 15.5 kDa) Brookfield Dry pick Brookfield Dry Brookfield Dry viscosity (m/s) viscosity IGT viscosity IGT
(mPa.$) RI 125 0.45 125 0.45 125 0.45 R5 254 0.49 128 0.50 147 0.60 R6 636 0.33 218 0.32 168 0.42 R7 853 0.25 230 0.24 182 0.25 Table 4: Brookfield viscosity of the coating compositions in which 14%, 30%
and 43% of latex are replaced with a mixture of dextrins and hydrolyzed proteins and pick property of the papers obtained On reading the results (table 4), it is noted that replacing the latex at more than 40% with any one of the hydrolyzed proteins tested does flot make it possible to maintain the pick resistance characteristics provided by the latex. Only the partially hydrolyzed soy and wheat protein hydrolyzates enable a replacement that can reach 35% (R6).
However, replacing the latex with the hydrolyzed soy protein leads to a clear increase in the viscosity starting from 14% (R1). This increase is accentuated at 30%
(R6) and 42% (R7), making the coating composition difficult to use. Such a viscosity does flot allow application at the industrial level since it would result in a considerable increase in pressure during the depositing, leading to machinability and paper quality problems.
)
(mPa.$) RI 125 0.45 125 0.45 125 0.45 R5 254 0.49 128 0.50 147 0.60 R6 636 0.33 218 0.32 168 0.42 R7 853 0.25 230 0.24 182 0.25 Table 4: Brookfield viscosity of the coating compositions in which 14%, 30%
and 43% of latex are replaced with a mixture of dextrins and hydrolyzed proteins and pick property of the papers obtained On reading the results (table 4), it is noted that replacing the latex at more than 40% with any one of the hydrolyzed proteins tested does flot make it possible to maintain the pick resistance characteristics provided by the latex. Only the partially hydrolyzed soy and wheat protein hydrolyzates enable a replacement that can reach 35% (R6).
However, replacing the latex with the hydrolyzed soy protein leads to a clear increase in the viscosity starting from 14% (R1). This increase is accentuated at 30%
(R6) and 42% (R7), making the coating composition difficult to use. Such a viscosity does flot allow application at the industrial level since it would result in a considerable increase in pressure during the depositing, leading to machinability and paper quality problems.
)
- 18 -Conversely, the low-molecular-weight wheat protein hydrolyzates have only a limited effect on the viscosity of the composition obtained but do flot make it possible to compensate for the reduction in latex starting from 30%. Indeed, at 30%
replacement of the latex, a loss of pick resistance is observed (0.45 of IGT
at 0%
replacement; 0.5 at 14% replacement for 0.30 at 30% replacement).
Among the various hydrolyzed proteins tested, only the partially hydrolyzed wheat proteins allow a significant increase in pick resistance at 14% latex replacement (composition R5).
Finally, only the partially hydrolyzed wheat proteins confer a maintaining both of the pick characteristics and also of the viscosity characteristics.
Indeed, 30%
replacement of the latex (R6) occurs with the pick resistance properties and also the viscosity characteristics of the composition obtained being maintained (0.45 m/s for 0 part replaced (R1) compared with 0.42 m/s for 30% replaced (R6)).
In addition, the advantage of the hydrolyzed wheat proteins is that, contrary to the soy proteins, they are soluble enough to be directly added to the coating color and do flot require a prior dilution adding a not insignificant amount of water and thus reducing the dry malter content of the coating color, thereby making it possible to vary quite freely the dry matter content of the composition.
replacement of the latex, a loss of pick resistance is observed (0.45 of IGT
at 0%
replacement; 0.5 at 14% replacement for 0.30 at 30% replacement).
Among the various hydrolyzed proteins tested, only the partially hydrolyzed wheat proteins allow a significant increase in pick resistance at 14% latex replacement (composition R5).
Finally, only the partially hydrolyzed wheat proteins confer a maintaining both of the pick characteristics and also of the viscosity characteristics.
Indeed, 30%
replacement of the latex (R6) occurs with the pick resistance properties and also the viscosity characteristics of the composition obtained being maintained (0.45 m/s for 0 part replaced (R1) compared with 0.42 m/s for 30% replaced (R6)).
In addition, the advantage of the hydrolyzed wheat proteins is that, contrary to the soy proteins, they are soluble enough to be directly added to the coating color and do flot require a prior dilution adding a not insignificant amount of water and thus reducing the dry malter content of the coating color, thereby making it possible to vary quite freely the dry matter content of the composition.
Claims (15)
1. A paper or cardboard coating composition having a dry mater content of between 45% and 80%, preferentially 50% and 78%, comprising:
.cndot. binders including at least one modified starch and one synthetic adhesive, .cndot. a hydrolyzed wheat protein having an average molecular weight of between 7 and 1000 kDa, and .cndot. a mineral filler.
.cndot. binders including at least one modified starch and one synthetic adhesive, .cndot. a hydrolyzed wheat protein having an average molecular weight of between 7 and 1000 kDa, and .cndot. a mineral filler.
2. The composition as claimed in claim I, characterized in that the hydrolyzed wheat protein has an average molecular weight of between 8 and 100 kDa, preferentially between 9 and 80 kDa.
3. The composition as claimed in either of claims 1 and 2, characterized in that it comprises, in parts per 100 parts by weight of mineral filler:
- I to 99 parts of binders, and - 1 to 50 parts by weight of wheat protein.
- I to 99 parts of binders, and - 1 to 50 parts by weight of wheat protein.
4. The composition as claimed in any one of claims 1 to 3, characterized in that it comprises a modified starch/synthetic adhesive ratio of from 1 :5 to 5:1.
5. The composition as claimed in any one of claims 1 to 4, characterized in that it comprises a binders/wheat protein ratio of from 1 :5 to 5:1.
6. The composition as claimed in any one of claims 1 to 5, characterized in that the modified starch is chosen from a pregelatinized starch, a dextrin, a hydrolyzed starch, an oxidized starch, a starch ester, a starch ether, a crosslinked starch and mixtures thereof; preferentially, said modified starch is a dextrin.
7. The composition as claimed in any one of the preceding claims, characterized in that the dextrin has a molecular weight of between 20 and 300 kDa, and/or a viscosity of between 50 and 400 mPa.s.
8. The composition as claimed in any one of the preceding claims, characterized in that the synthetic adhesive is chosen from the group made up of latexes, vinyl acetates, polyvinyl alcohol, sodium carboxymethylcellulose and hydroxyethylcellulose.
9. The composition as claimed in any one of the preceding claims, characterized in that the synthetic adhesive is a latex preferentially chosen from the group made up of styrene-butadiene latexes, polyvinyl alcohol latexes and acrylic copolymer latexes.
10. A method for producing the composition as claimed in any one of claims 1 to 9, comprising the following steps:
- mixing, with stirring, a mineral rifler and binders which include at least one modified starch and one synthetic adhesive, said modified starch preferentially having previously undergone a cooking step, - adding, with stirring, to the mixture obtained, a hydrolyzed wheat protein having an average molecular weight of between 7 and 1000 kDa, said hydrolyzed wheat protein preferentially being in a pulverulent forrn, adding water, with stirring, so as to obtain a composition having a dry matter content of between 45% and 80%; typically, the adding of water is carried out with the minerai filler and/or the modified starch and/or the hydrolyzed protein.
- mixing, with stirring, a mineral rifler and binders which include at least one modified starch and one synthetic adhesive, said modified starch preferentially having previously undergone a cooking step, - adding, with stirring, to the mixture obtained, a hydrolyzed wheat protein having an average molecular weight of between 7 and 1000 kDa, said hydrolyzed wheat protein preferentially being in a pulverulent forrn, adding water, with stirring, so as to obtain a composition having a dry matter content of between 45% and 80%; typically, the adding of water is carried out with the minerai filler and/or the modified starch and/or the hydrolyzed protein.
11. A method for coating or brightening paper or cardboard, said method comprising the steps consisting of (a) the provision of a composition as claimed in any one of claims 1 to 9, (b) the depositing of said composition on a paper or cardboard substrate.
12. A paper or cardboard coated with the composition as claimed in any one of claims 1 to 9 or obtained by a means of the method as claimed in claim 11.
13. The use of a hydrolyzed wheat protein in the replacement of latex in a paper or cardboard coating composition, said hydrolyzed wheat protein preferentially having an average molecular weight of between 7 and 1000 kDa.
14. The use as claimed in claim 13, characterized in that said composition comprises .cndot. binders which include at least one modified starch and one preferentially synthetic adhesive, .cndot. a hydrolyzed wheat protein having an average molecular weight of between 7 and 1000 kDa, and .cndot. a mineral filler.
15. The use as claimed in either of claims 13 and 14, characterized in that the binders/wheat protein ratio is from 1:5 to 5:1.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR1500337A FR3032979B1 (fr) | 2015-02-23 | 2015-02-23 | Composition de couchage comprenant des proteines de ble hydrolysees |
| FR15/00337 | 2015-02-23 | ||
| PCT/IB2016/050969 WO2016135625A1 (fr) | 2015-02-23 | 2016-02-23 | Composition de couchage comprenant des protéines de blé hydrolysées |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2975499A1 true CA2975499A1 (fr) | 2016-09-01 |
Family
ID=52807949
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2975499A Abandoned CA2975499A1 (fr) | 2015-02-23 | 2016-02-23 | Coating composition comprising hydrolysed wheat proteins |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US20180044858A1 (fr) |
| EP (1) | EP3262232B1 (fr) |
| JP (1) | JP2018511712A (fr) |
| CN (1) | CN107532390A (fr) |
| BE (1) | BE1023282B1 (fr) |
| BR (1) | BR112017015729A2 (fr) |
| CA (1) | CA2975499A1 (fr) |
| FR (1) | FR3032979B1 (fr) |
| WO (1) | WO2016135625A1 (fr) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11525217B2 (en) | 2019-12-17 | 2022-12-13 | Westrock Mwv, Llc | Coated paper and paperboard structures |
| US11440269B2 (en) * | 2020-03-14 | 2022-09-13 | Kurtis Zhang | Process of making a gluten-based biodegradable material |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB674131A (en) * | 1948-09-22 | 1952-06-18 | American Cyanamid Co | Improvements in or relating to proteinaceous compositions |
| GB9123251D0 (en) * | 1991-11-01 | 1991-12-18 | Croda Int Plc | Protein-silicone copolymers |
| US5268030A (en) * | 1992-03-23 | 1993-12-07 | Sequa Chemicals Inc. | Paper coating composition containing a zirconium chelate insolubilizer |
| US5766331A (en) * | 1996-10-25 | 1998-06-16 | Protein Technologies International, Inc. | Protein adhesive binder and process for forming a protein adhesive binder |
| US6517625B2 (en) * | 2001-01-03 | 2003-02-11 | Mgp Ingredients, Inc. | Protein/starch paper coating compositions and method of use thereof |
| AU2003901311A0 (en) * | 2003-03-21 | 2003-04-03 | George Weston Foods Limited | Coating compositions |
| US7625441B2 (en) | 2005-02-09 | 2009-12-01 | Solae, Llc | Paper coating formulation having a reduced level of binder |
| CA2679073A1 (fr) | 2007-02-27 | 2008-09-04 | Cargill, Incorporated | Compositions de revetement contenant des matieres amylacees |
| AU2010282530B2 (en) * | 2009-08-12 | 2015-04-09 | Newpage Corporation | Inkjet recording medium |
| US10370553B2 (en) * | 2011-11-18 | 2019-08-06 | Roquette Freres | Partially soluble dextrins of high molecular weight |
| CN102864689A (zh) * | 2012-09-21 | 2013-01-09 | 江南大学 | 一种小麦蛋白质涂布食品包装纸及其制备方法 |
-
2015
- 2015-02-23 FR FR1500337A patent/FR3032979B1/fr not_active Expired - Fee Related
-
2016
- 2016-02-23 BE BE2016/5128A patent/BE1023282B1/nl not_active IP Right Cessation
- 2016-02-23 US US15/553,132 patent/US20180044858A1/en not_active Abandoned
- 2016-02-23 EP EP16707224.8A patent/EP3262232B1/fr active Active
- 2016-02-23 BR BR112017015729A patent/BR112017015729A2/pt not_active Application Discontinuation
- 2016-02-23 JP JP2017544638A patent/JP2018511712A/ja not_active Withdrawn
- 2016-02-23 CN CN201680011610.9A patent/CN107532390A/zh active Pending
- 2016-02-23 WO PCT/IB2016/050969 patent/WO2016135625A1/fr active Application Filing
- 2016-02-23 CA CA2975499A patent/CA2975499A1/fr not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| WO2016135625A1 (fr) | 2016-09-01 |
| BE1023282A1 (nl) | 2017-01-20 |
| EP3262232B1 (fr) | 2019-04-03 |
| JP2018511712A (ja) | 2018-04-26 |
| EP3262232A1 (fr) | 2018-01-03 |
| BE1023282B1 (nl) | 2017-01-20 |
| FR3032979B1 (fr) | 2017-02-10 |
| BR112017015729A2 (pt) | 2018-03-13 |
| FR3032979A1 (fr) | 2016-08-26 |
| CN107532390A (zh) | 2018-01-02 |
| US20180044858A1 (en) | 2018-02-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |
Effective date: 20210831 |
|
| FZDE | Discontinued |
Effective date: 20210831 |