JP7413904B2 - Paper additives and paper - Google Patents

Description

The present invention relates to a paper additive that does not use epihalohydrin, does not inhibit the size effect of a sizing agent, and has an excellent effect of improving paper thickness and suppressing foaming within a papermaking system, and a paper using the same.

Due to the deterioration of the raw wood supply situation in recent years and the protection of the global environment, there is a need for paper that maintains conventional quality while reducing the amount of pulp used. However, simply reducing the amount of pulp in order to make the paper lighter will make the paper thinner, lowering its opacity, and printing may be visible through the back. Therefore, there is a need for a chemical that can reduce the amount of pulp while maintaining paper thickness, that is, that can improve paper thickness.

As a chemical for improving paper thickness, it is known that a reaction product of an amide compound obtained by the reaction of fatty acids and polyalkylene polyamines and epihalohydrin is useful as a porosity improver and an opacity improver. (For example, see Patent Documents 1 and 2). Further, paper additives containing compounds obtained by crosslinking these amide compounds with urea are also known as chemicals for improving paper thickness (for example, see Patent Document 3). With these compounds, the effect of improving paper thickness is not at a fully satisfactory level, and the epihalohydrin used and by-products from the epihalohydrin remain, but it is preferable to reduce these as much as possible from the viewpoint of reducing environmental load.

Paper bulking agents consisting of ester reaction products of polyhydric alcohols and fatty acids (see, for example, Patent Document 4), which contain linear fatty acid monoamides as main components, are chemicals that are not reactants with epihalohydrin but have the effect of improving paper thickness. Paper bulking agents (for example, see Patent Document 5) are known, but these also do not have a fully satisfactory effect on improving paper thickness, and may also cause the paper to become slippery. There were problems such as significantly reducing the size effect of

Japanese Patent Application Publication No. 61-252400 Japanese Patent Application Publication No. 2000-273792 Japanese Patent Application Publication No. 2005-60891 Patent No. 2971447 Japanese Patent Application Publication No. 2007-231485

An object of the present invention is to provide a paper additive that does not use epihalohydrin, does not inhibit the size effect of a sizing agent, and has an excellent effect of improving paper thickness and suppressing foaming within the papermaking system, and a paper using the same. It is.

As a result of intensive research to solve the above problems, the present inventors have discovered that a compound obtained by reacting a polyalkylene polyamine, a monovalent fatty acid having a specific number of carbon atoms, and ureas with a specific composition. The inventors have discovered that a paper additive containing an acrylamide and/or methacrylamide-based polymer exhibits an excellent paper thickness improvement effect when added to a pulp slurry, and has completed the present invention.
That is, the present invention
<1> Contains the following compound (A) and the following (meth)acrylamide-based polymer (B), and the mass ratio of the compound (A) and the (meth)acrylamide-based polymer (B) is (A):(B)= A paper additive characterized in that the ratio is 99-70:1-30,
Compound (A):
Reaction product of polyalkylene polyamine (a-1) having 3 to 5 amino groups in one molecule, monovalent fatty acid (a-2) with 8 to 22 carbon atoms, and urea (a-3) (Meth)acrylamide polymer (B):
(b-1) anionic monomer, (b-2) hydrophobic monomer, and (b-3) (meth)acrylamide, (b-1):(b-2):(b-3)= Polymer of monomers contained in a ratio of 3 to 20:5 to 15:65 to 92 (mol%) <2> (b-2) Hydrophobic monomer has an alkyl group or cycloalkyl group having 1 to 20 carbon atoms The paper additive according to <1> above, which is an alkyl (meth)acrylate;
<3>(b-1) The anionic monomer according to <1> above, wherein the anionic monomer is at least one selected from a monomer having a carboxyl group, a monomer having a sulfonic acid group, and a salt thereof. additives for paper,
<4> The paper additive according to any one of <1> to <3>, which is a paper thickness improver;
<5> Paper containing the paper additive according to any one of <1> to <4>above;
It is.

According to the present invention, it is possible to provide a paper additive that has an excellent effect of improving paper thickness, suppressing size inhibition, and suppressing foaming in a papermaking system, even though epihalohydrin is not used, and improves paper products. The amount of pulp raw material used during production can be reduced.

The paper additive of the present invention contains a compound (A) and a (meth)acrylamide-based polymer (B). Note that "(meth)acrylic" in the present invention means "acrylic or methacryl".

Compound (A) consists of a polyalkylene polyamine (a-1) having 3 to 5 amino groups in one molecule, a monovalent fatty acid (a-2) with 8 to 22 carbon atoms, and a urea (a-3). ).

Examples of the polyalkylene polyamine (a-1) having 3 to 5 amino groups in one molecule include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenetriamine, tripropylenetetramine, etc. , diethylenetriamine, triethylenetetramine, and tetraethylenepentamine are preferred because they are industrially easily available and inexpensive. One type of polyalkylene polyamine (a-1) may be used alone, or two or more types may be used in combination.

The monovalent fatty acid (a-2) having 8 to 22 carbon atoms may be saturated or unsaturated, and may be linear or branched. Specifically, octanoic acid (caprylic acid) with 8 carbon atoms, 2-ethylhexanoic acid, decanoic acid (capric acid) with 10 carbon atoms, dodecanoic acid (lauric acid) with 12 carbon atoms, and tetradecanoic acid with 14 carbon atoms. (myristic acid), hexadecanoic acid with 16 carbon atoms (palmitic acid), octadecanoic acid with 18 carbon atoms (stearic acid), 16-methylheptadecanoic acid (isostearic acid), cis-9-octadecenoic acid (oleic acid), cis , cis-9,12-octadecadienoic acid (linoleic acid), 9,12,15-octadecanetrienoic acid ((9,12,15)-linolenic acid), 6,9,12-octadecatrienoic acid (( (6,9,12)-linolenic acid), icosanoic acid (arachidic acid) having 20 carbon atoms, docosanoic acid (behenic acid) having 22 carbon atoms, and esterified products or acid halides of these fatty acids. Examples of mixed fatty acids and hydrogenated fatty acids include beef tallow fatty acid, coconut fatty acid, palm oil fatty acid, castor oil fatty acid, soybean oil fatty acid, tall oil fatty acid, and their hardened products. Among these, monohydric fatty acids having 12 to 22 carbon atoms are preferred because they are easily available industrially and have a high effect of improving paper thickness. More preferred are saturated monovalent fatty acids having 12 to 20 carbon atoms. One type of monovalent fatty acid (a-2) may be used alone, or two or more types may be used in combination.

The ureas of component (a-3) in the present invention include urea, thiourea, guanylurea, methylurea, dimethylurea, etc. Among these, urea is preferred because it is easily available industrially and is inexpensive. . The ureas (a-3) may be used alone or in combination of two or more.

The carbonyl group of the monohydric fatty acid (a-2) is preferably 0.40 to 0.65 equivalent per equivalent of the amino group of the polyalkylene polyamine (a-1). If it is less than 0.40 equivalent, the hydrophobic sites derived from (a-2) in compound (A) are reduced, so that the desired paper thickness improvement effect and size inhibition suppression effect may not be obtained. In addition, if the amount exceeds 0.65 equivalent, the number of reaction sites for ureas decreases, resulting in fewer ureido groups derived from ureas, and the hydrogen bonding force with the pulp decreases, resulting in the desired effect of improving paper thickness and suppressing size inhibition. may not be obtained. More preferably, the amount is 0.45 to 0.60 equivalent.
The amount of urea (a-3) per equivalent of amino group in polyalkylene polyamine (a-1) is preferably 0.1 to 0.4 equivalent. If it exceeds 0.4 equivalent, the desired effect of improving paper thickness and suppressing size inhibition may not be obtained because the number of hydrophobic sites decreases. Moreover, if it is less than 0.1 equivalent, the number of ureido groups derived from ureas will decrease, and the hydrogen bonding force with the pulp will decrease, so the desired paper thickness improvement effect and size inhibition suppressing effect may not be obtained. More preferably, the amount is 0.2 to 0.4 equivalent.

Reaction product of polyalkylene polyamine (a-1) having 3 to 5 amino groups in one molecule, monovalent fatty acid (a-2) with 8 to 22 carbon atoms, and urea (a-3) Compound (A) may be produced by any method, but for example, polyalkylene polyamine (a-1) and monovalent fatty acid (a-2) may be mixed with a known amidation catalyst if necessary. A method of reacting with urea (a-3) for 0.5 to 10 hours at 100 to 200°C for 0.5 to 5 hours while removing by-product ammonia. etc. can be mentioned.

(Meth)acrylamide-based polymer (B) (hereinafter sometimes referred to as "polymer (B)") comprises (b-1) an anionic monomer, (b-2) a hydrophobic monomer, and (b-3) (meth)acrylamide in a ratio of (b-1):(b-2):(b-3)=3 to 20:5 to 15:65 to 92 (mol%). .

The paper additive is an emulsion using water as a medium, and the polymer (B) is considered to function as an emulsifying and dispersing agent for the compound (A), which is highly hydrophobic and difficult to disperse in water alone. (b-1) By introducing the anionic monomer into the polymer chain of polymer (B), it contributes to the stabilization of the emulsion due to electrostatic repulsion between emulsion particles, and furthermore, the paper additive is added to the paper making system. When this happens, the paper additives are more efficiently fixed on the pulp surface through the cationic substance sulfuric acid, various metal salts present in the papermaking system, and retention agents, which improves paper thickness, suppresses size inhibition, and improves paper thickness. It is thought that the foaming suppressing effect can be enhanced. (b-2) By introducing a hydrophobic monomer into the polymer chain of polymer (B), hydrophobic groups such as alkyl groups and cycloalkyl groups, which are ester residues of (meth)acrylic esters, can be added. Due to the high affinity caused by the hydrophobic-hydrophobic interaction between the polymer (B) and the compound (A), the polymer (B) more firmly adheres to the particle surface of the compound (A), which improves the dispersibility of the paper additive (to prevent foreign matter formation during manufacturing). It is thought that this contributes to the suppression of sedimentation during storage (storage stability), mechanical stability, dilution stability, paper thickness improvement effect, size inhibition suppression effect, foaming suppression effect, etc.

(b-1) The anionic monomer is preferably at least one selected from monomers having a carboxyl group, monomers having a sulfonic acid group, and salts thereof. Examples of monomers having a carboxyl group (hereinafter referred to as carboxylic acid monomers) include polyvalent carboxylic acid monomers such as monobasic carboxylic acid monomers and dibasic carboxylic acid monomers, and their acid anhydrides. Specific examples include (meth)acrylic acid, maleic anhydride, maleic acid, fumaric acid, itaconic anhydride, itaconic acid, citraconic anhydride, citraconic acid, and the like. Examples of monomers having a sulfonic acid group (hereinafter referred to as sulfonic acid monomers) include styrene sulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, sulfoethyl (meth)acrylate, and (meth)allyl. Examples include sulfonic acid monomers such as sulfonic acid and/or sulfuric acid ester monomers such as sulfuric ester of hydroxyethyl (meth)acrylate. Examples of salts of carboxyl groups and sulfonic acid groups include alkali metal salts such as sodium and potassium salts, ammonium salts, and alkylamine salts.

(b-1) Anionic monomers can be used alone or in combination of two or more, but in the present invention, the sulfonic acid monomers contribute to dispersion stability compared to the carboxylic acid monomers, while Carboxylic acid monomers are superior to sulfonic acid monomers in terms of fixation of the paper additive, which is an emulsion, to the pulp surface. Therefore, the amount of the sulfonic acid monomers should be less than half of the amount of the carboxylic acid monomers. preferable. The amount of the anionic monomer (b-1) used is preferably 3 to 20 mol%, more preferably 5 to 15 mol%, based on the total molar sum of the monomers constituting the polymer (B).

(b-1) Emulsifying and dispersing compound (A) in water with polymer (B) in which the amount of anionic monomer used is in the range of 3 to 20 mol% of the total molar sum of monomers constituting polymer (B) By doing so, a paper additive with excellent stability and performance can be obtained. (b-1) When the amount of anionic monomer used is less than 3 mol%, the ability to emulsify and disperse compound (A) will be reduced by polymer (B) due to insufficient electrostatic repulsion between particles due to lack of anionic property. If the paper additive is not applied sufficiently, the dispersed particles may aggregate during the production or storage of the paper additive, causing the formation of foreign matter, sedimentation of the dispersed particles, or thickening of the paper additive itself, resulting in a decrease in the paper thickness improvement effect. There are concerns about contamination of manufacturing equipment, storage containers, and papermaking equipment, and increased pump load during liquid transfer. In addition, due to the lack of anionic properties, when paper additives are added to the papermaking system, the amount of salt formed between the polymer (B) on the particle surface and the (polyvalent) metal derived from sulfate band is insufficient, and the paper additives The fixation of the agent to the pulp decreases, and sufficient effects of improving paper thickness, suppressing size inhibition, and suppressing foaming cannot be obtained.
On the other hand, if the amount of (b-1) anionic monomer used is more than 20 mol%, the dispersion particles may aggregate during paper additive manufacturing or storage, resulting in the formation of foreign matter, sedimentation of the dispersed particles, or paper additives. This causes the additive itself to thicken, and in the papermaking system, polyvalent metal salts derived from polymer (B) and sulfuric acid bands form excessive salts, causing aggregation of the dispersion of the paper additive. The effect of improving paper thickness and the effect of inhibiting size suppression are reduced.

(b-2) Hydrophobic monomers include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, normal octyl (meth)acrylate, and (meth)acrylate. 2-ethylhexyl acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, isobornyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, (meth)acrylate ) Alkyl (meth)acrylates having an alkyl group or cycloalkyl group having 1 to 20 carbon atoms such as isostearyl acrylate; Other (meth)acrylic esters such as allyl (meth)acrylate and benzyl (meth)acrylate ; Styrene, α-methylstyrene, vinyltoluene, divinylbenzene, and styrenes having an alkyl group having 1 to 4 carbon atoms in their aromatic ring; carbon number of carboxylic acids such as vinyl acetate, vinyl propionate, and vinyl neodecanoate; Examples include carboxylic acid vinyl esters in which the number is 1 to 20. These may be used alone or in combination of two or more. Among these, alkyl (meth)acrylates having an alkyl group or cycloalkyl group having 1 to 20 carbon atoms are preferred because they are industrially easily available and inexpensive.

(b-2) The amount of the hydrophobic monomer used is preferably 5 to 15 mol%, more preferably 7 to 10 mol% of the total molar sum of the monomers constituting the polymer (B). (b-2) By using 5 to 15 mol% of the hydrophobic monomer, the paper additive obtained as an emulsion through the emulsification and dispersion process has excellent dispersibility, sedimentation suppression effect, and dilution stability. Become. Furthermore, when used as a paper additive, it has excellent effects on improving paper thickness, suppressing size inhibition, and suppressing foaming.

(b-3) The (meth)acrylamide is acrylamide and/or methacrylamide, and the amount used is preferably 65 to 92 mol%, and 75 to 88 mol% of the total molar sum of monomers constituting the polymer (B). is even more preferable. (b-3) A paper additive with excellent dispersibility by dispersing compound (A) in water with polymer (B) in which the amount of acrylamide and/or methacrylamide used is in the range of 65 to 92 mol%. is obtained.

In addition to the above (b-1) to (b-3), other monomers may be added to the copolymerization component of the polymer (B) to the extent that they do not impede the effects of the present invention. Other monomers include, for example, cationic monomers, nonionic monomers, crosslinking agents, and chain transfer agents.

Specifically, the cationic monomers include aminoalkyl (meth)acrylate, aminohydroxyalkyl (meth)acrylate, aminoalkyl (meth)acrylamide, vinylimidazole, diallylamine, etc., as well as quaternary ammonium salts and nonions thereof. Examples of the monomer include hydroxyalkyl (meth)acrylate and the like. The amount of these monomers to be used is preferably at most 10 mol % or less based on 100 mol % of the total molar sum of monomers (b-1) to (b-3).

The crosslinking agent is not particularly limited as long as it is a polyfunctional monomer having two or more radically polymerizable functional groups, and any known crosslinking agent can be used. ) Acrylamides, hexanediol diacrylate, tetraethylene glycol diacrylate, hexaethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, 1,3,5-triacryloylhexahydro-1,3,5- Examples include polyfunctional (meth)acrylates such as triazine and aromatic polyvinyl compounds such as divinylbenzene. It is preferable that one kind or at least two or more of these monomers are used in an amount of at most 5 mol % or less based on 100 mol % of the total molar sum of monomers (b-1) to (b-3). By using more than 5 mol% of the crosslinking agent, excessive branched (crosslinked) structures are introduced into the polymer (B), which improves the dispersibility, storage stability, mechanical stability, and dilution stability of the paper additive. Sexuality may be impaired.

Examples of chain transfer agents include mercaptan compounds, specifically 2-mercaptoethanol, mercaptopropanol, mercaptobutanol, mercaptoglycol, thioglycerin, cysteamine hydrochloride, mercaptopropionic acid and its salts, thioglycolic acid and its salts. salts, thioacetic acid and its salts, thiomalic acid, mercaptopropionic acid esters such as 2-ethylhexyl mercaptopropionate and n-octyl mercaptopropionate, thioglycolic acids such as 2-ethylhexyl thioglycolate and n-octyl thioglycolate. Examples include esters and mercaptans such as n-dodecylmercaptan, t-dodecylmercaptan, and n-octylmercaptan. Furthermore, 2,4-diphenyl-4-methyl-1-pentene, which is an unsaturated dimer of α-methylstyrene, can also be used as a chain transfer agent. It is preferable that one kind or at least two or more of these monomers be used in an amount of at most 5 mol % or less based on 100 mol % of the total molar sum of monomers (b-1) to (b-3). If it exceeds 5 mol%, the dispersibility, storage stability, mechanical stability, and dilution stability of the paper additive containing the polymer (B) may be impaired.

Polymer (B) can be produced by various known methods such as solution polymerization, emulsion polymerization, and suspension polymerization, and is obtained by copolymerizing the monomers mentioned above. In the case of solution polymerization, solvents such as isopropyl alcohol, ethyl alcohol, and methyl isobutyl ketone can be used. The emulsifier used in the emulsion polymerization method is not particularly limited, and various anionic surfactants, nonionic surfactants, and reactive surfactants can be used. Further, the polymerization initiator used in the polymerization is not particularly limited, and various types of initiators such as persulfates, peroxides, azo compounds, and redox initiators can be used. Furthermore, acids, alkalis, and buffers can be added as pH adjusters. There are no particular restrictions on the acid, and various acids can be used, including inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, and nitric acid, organic acids such as acetic acid, lactic acid, and citric acid, and acidic salts such as aluminum sulfate and aluminum chloride. can. The alkali is not particularly limited, and various alkalis such as sodium hydroxide, potassium hydroxide, ammonia, alkylamines, and alkylolamines can be used. The buffer is not particularly limited, and various buffers such as phosphate buffer, acetate buffer, and citrate buffer can be used. Acids, alkalis, and buffers can be used alone or in combination of two or more.

The mass ratio of compound (A) and polymer (B) in the paper additive of the present invention must be (A):(B) = 99-70:1-30 as solid content, and 90-80:10. ~20 is preferred. If the content of the polymer (B) in the paper additive is less than 1% by mass, the emulsifying and dispersing ability will not be sufficient, and the storage stability, mechanical stability, and dilution stability will also be poor. Moreover, if it is used in an amount exceeding 30% by mass, the viscosity of the paper additive increases, and in order to achieve a viscosity that can be pumped, the solid content of the product must be reduced, leading to an increase in cost. Further, the surplus polymer (B) that does not contribute to the dispersion of the compound (A) causes an increase in foaming within the papermaking system.

In the present invention, the method for preparing the paper additive from the compound (A) and the polymer (B) is not particularly limited, but for example, as described in Japanese Patent Publication No. 54-36242, Japanese Patent Publication No. 53-32380 discloses a so-called solvent method in which a solution of polymer (B) and water are mixed in advance in an oil-soluble solvent, treated with a homogenizer, and then the solvent is distilled off to produce an oil-in-water emulsion. As described in JP-A-52-77206, a so-called mechanical method involves mixing the molten compound (A) with polymer (B) and water under high temperature and high pressure, and producing an oil-in-water emulsion through a homogenizer, as described in JP-A-52-77206. As described in the publication, after the polymer (B) and some water are mixed with the molten compound (A) component, water is further added to form a water-in-oil emulsion, and then water is inverted. A so-called phase inversion method is used in which the phase is transformed into an oil-in-water emulsion. Also used is a mechanical method of forming an oil-in-water emulsion using a high-shear rotary emulsifying disperser as described in JP-A-10-226981.

The solid content of the paper additive of the present invention is preferably 10% by mass or more and 50% by mass or less, more preferably 15% by mass or more and 35% by mass or less. If the solid content exceeds 50% by mass, the viscosity tends to increase over time, and as the solid content concentration at the liquid surface increases during storage, aggregates are likely to form (easily form a skin).If the solid content is less than 10% by mass, It is not economical because the amount of active ingredients is reduced.

Note that the solid content in the present invention refers to the percentage of the remaining mass after heating and drying the paper additive at 150° C. for 20 minutes to the mass before heating.

The viscosity of the paper additive of the present invention is preferably 100 mPa·s or less, more preferably 60 mPa·s or less.

The average particle diameter (cumulative 50% diameter in weight-based particle size distribution) of the paper additive of the present invention is preferably 0.3 to 1.0 μm. If the particle size exceeds 1.0 μm, the particles tend to settle during storage and have poor mechanical stability. When the thickness is 0.3 μm or less, an increase in viscosity and the amount of skinning is observed. The average particle diameter in the present invention is measured using a laser diffraction/scattering particle size distribution analyzer Microtrac MT3300EXII (manufactured by Microtrac Bell).

In preparing additives for paper using these methods, various surfactants other than the (meth)acrylamide-based polymer (B) used as an emulsifying and dispersing agent for compound (A), casein, lecithin, polyvinyl alcohol, Protective colloids such as cationic, anionic or amphoteric modified starches may be used in combination.

As the "various surfactants other than (meth)acrylamide polymer (B)" (hereinafter sometimes simply referred to as surfactants), known surfactants can be used as appropriate. For example, nonionic surfactants such as fatty acid sorbitan esters, fatty acid polyglycol esters, fatty acid amides, and various polyalkylene oxide type nonionic surfactants whose alkyl and/or alkenyl groups have 4 to 20 carbon atoms, alkyl long-chain alkylamine salts, polyoxyalkyleneamines, tetraalkyl quaternary ammonium salts, trialkylbenzyl quaternary ammonium salts, alkylimidazolium salts, alkylpyridinium salts, in which the group and/or alkenyl group has 4 to 20 carbon atoms; Examples include cationic surfactants such as alkylquinolium salts, alkylphosphonium salts, and alkylsulfonium salts, and amphoteric surfactants such as various betaine surfactants.

The above-mentioned surfactants can be used alone or in combination of two or more. When using a surfactant, the amount used is preferably 0.1 to 20% by mass based on 100% by mass of compound (A) in order to suppress foaming properties and increase dispersibility. More preferably 0.5 to 10% by mass.

The paper additive of the present invention may be used in addition to antifoaming agents, thickeners, preservatives, rust preventives, etc., as long as it does not impair the effects of the present invention and does not affect stability during storage. Various additives such as the above-mentioned pH adjusting agent, filler, antioxidant, filler, and dye may be added.

The paper additive of the present invention can be used as a paper thickness improver. Although it depends on the type of paper or paperboard and the desired paper thickness improvement effect, the desired paper thickness is usually achieved by adding 0.1 to 1.5% by mass of solids based on the dry mass of pulp slurry. It is possible to obtain an improvement effect. It can also be used as a surface treatment agent for paper, in which case it is applied to pre-formed wet paper or paper by conventional methods such as spraying, dipping, coating, etc.

Paper containing the paper additive of the present invention includes, but is not particularly limited to, various papers and paperboards. Paper types include PPC paper, inkjet printing paper, laser printer paper, foam paper, thermal transfer paper, thermal recording paper, pressure-sensitive recording paper, photographic paper and its base paper, art paper, cast coated paper, and high quality paper. Coated base paper such as coated paper, packaging paper such as craft paper, pure white roll paper, household thin paper such as tissue paper, toilet paper, towel paper, kitchen paper, other paper for notebooks, book paper, various printing papers, newsprint, etc. Examples include various papers (Western paper), paperboard for folding cartons such as manila ball, white ball, and chipboard, paperboard such as liner, core, and base paper for gypsum board. Examples of materials other than paper include modified wood and inorganic building materials, such as particle board, hardboard, insulation board, and rock wool board. Among these, the paper thickness enhancement effect can add thickness and flexibility to paper, so various printing papers and book papers that improve printability and readability, folding paperboard and paperboard that improve folding strength, and paperboard that has a good texture. It is preferable to use household tissue paper that imparts

The paper of the present invention can be used as pulp raw materials such as bleached or unbleached chemical pulp such as kraft pulp or sulfite pulp, bleached or unbleached high-yield pulp such as ground wood pulp, mechanical pulp or thermomechanical pulp, used newspaper, used magazine paper, and cardboard. It can contain waste paper pulp such as waste paper or deinked waste paper. Further, it may contain a mixture of the pulp raw material and synthetic fibers such as polyamide, polyimide, polyester, polyolefin, and polyvinyl alcohol.

In manufacturing the paper of the present invention, additives commonly used in paper manufacturing such as fillers, sizing agents, dry paper strength improvers, wet paper strength improvers, retention improvers, and drainage improvers are also added. , may be used as necessary to achieve the physical properties required for each paper type. These may be used alone or in combination of two or more. Further, these can be mixed in advance with the paper additive of the present invention and added to the paper stock for use, and the method of mixing is not particularly limited.

Examples of the filler include clay, talc, white carbon, titanium oxide, and calcium carbonate, and these may be used alone or in combination of two or more.

Sizing agents include fatty acid soap sizing agents such as sodium stearate, rosin, reinforced rosin and rosin ester sizing agents (hereinafter sometimes referred to as "rosin sizing agents"), aqueous emulsions of alkenyl succinic anhydride ( (hereinafter sometimes referred to as "ASA sizing agent"), aqueous emulsion of 2-oxetanone (hereinafter sometimes referred to as "AKD sizing agent"), aqueous emulsion of paraffin wax, reaction between carboxylic acid and polyvalent amine Examples include cationic sizing agents obtained by, aqueous emulsions of reaction products of aliphatic oxyacids and aliphatic amines or aliphatic alcohols, and cationic styrene-based sizing agents. These may be used alone or in combination of two or more.

Examples of the dry paper strength improver include anionic polyacrylamide, cationic polyacrylamide, amphoteric polyacrylamide, cationized starch, and amphoteric starch, which may be used alone or in combination of two or more. Also good.

Examples of wet paper strength improvers include polyamide/epichlorohydrin resin, polyvinylamine, melamine/formaldehyde resin, and urea/formaldehyde resin, which may be used alone or in combination with anionic polyacrylamide. It's okay.

Examples of the retention improver include anionic, cationic, or amphoteric high molecular weight polyacrylamide, polyvinylamine, a combination of silica sol and cationized starch, and a combination of bentonite and cationic high molecular weight polyacrylamide. These may be used alone or in combination of two or more.

Examples of the drainage improver include polyethyleneimine, cationic, amphoteric, or anionic polyacrylamide, polyvinylamine, and the like. These may be used alone or in combination of two or more.

In addition, we use size presses, gate roll coaters, bill blade coaters, calendars, etc. to add surface paper strength improvers such as starch, polyvinyl alcohol, and acrylamide polymers, dyes, coating colors, surface sizing agents, and anti-slip agents as necessary. You can also apply it. These may be used alone or in combination of two or more. Furthermore, the sulfuric acid band may be used before, after, or simultaneously with the addition of the paper additive of the present invention.

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto. In addition, all parts and percentages below are based on mass unless otherwise specified.

(Synthesis of A)
Synthesis example 1
In a separable flask equipped with a thermometer, a cooling tube, and a stirrer, 189.3 g (1.0 mol) of tetraethylenepentamine was added as polyalkylene polyamine (a-1), and Sakura stearic acid was added as monovalent fatty acid (a-2). 550.0 g (NOF, stearic acid/palmitic acid mixture, 2.0 mol, 0.40 equivalent to amine) was added, the temperature was raised to 170°C, and while removing the water produced, the mixture was heated to 90°C. Allowed time to react. Thereafter, the mixture was cooled to 130° C., and 20 g of water and 96.2 g (1.6 moles, 0.32 equivalents of amine) of urea were added, and the mixture was reacted at 140° C. for 5 hours while removing the generated ammonia. 772 g of compound (A) M-1 with a solid content of 100% was obtained.

Synthesis examples 2 to 9
Synthesized in the same manner as in Synthesis Example 1, except that the amount of Sakura stearate, which is a monovalent fatty acid (a-2), and the amount of urea, which is a urea (a-3), were changed as shown in Table 1. Compounds (A) M-2 to M-9 were obtained.

Comparative synthesis example 1
In a separable flask equipped with a thermometer, a cooling tube, and a stirrer, 189.3 g (1.0 mol) of tetraethylenepentamine was added as polyalkylene polyamine (a-1), and Sakura stearic acid was added as monovalent fatty acid (a-2). Added 687.5 g (NOF, stearic acid/palmitic acid mixture, 2.5 mol, 0.50 equivalent to amine), heated to 170°C, and heated at 170°C for 9 hours while removing generated water. The reaction was carried out to obtain 831 g of Comparative Example Compound (A) RM-1 with a solid content of 100% without reacting urea.

(Synthesis of B)
Synthesis example 10
In a flask equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube, 210.2 g of ion-exchanged water, 322.1 g of isopropyl alcohol (IPA), and (b-1) itaconic acid as an anionic monomer were added under a nitrogen atmosphere while stirring at 25°C. (IA) 10.8 g (2 mol%) and sodium styrene sulfonate (NaSS) 8.5 g (1 mol%), (b-2) cyclohexyl methacrylate (CHMA) 48.8 g (7 mol%) as a hydrophobic monomer. ), (b-3) 523.0 g (90 mol%) of 50% acrylamide (AAm) aqueous solution as acrylamide and/or methacrylamide, and 8.4 g (1.0 mol%) of normal dodecyl mercaptan (NDM) as a chain transfer agent. and 3.2 g (1.0 mol%) of mercaptoethanol (MET) and 13.3 g of a 25% aqueous sodium hydroxide solution as a pH adjuster, and after raising the temperature to 60°C, azobisisobutyronitrile 3 was added as an initiator. .4 g was added to start the polymerization reaction, and the reaction was carried out at 75°C for 5 hours. Next, isopropyl alcohol was distilled off, and after cooling, 260.1 g of ion-exchanged water was added, and the mixture was cooled to room temperature to obtain Polymer (B) P-1 with a solid content of 35%.

Synthesis Examples 11 to 23 and Comparative Synthesis Examples 2 to 5
As listed in Table 2, (b-1) type and amount of anionic monomer, (b-2) type and amount of hydrophobic monomer, (b-3) acrylamide (AAm) which is acrylamide and/or methacrylamide. P-2 to P-, which are polymers (B) with a solid content of 35%, were synthesized in the same manner as Synthesis Example 10 except that the amount of , the type and amount of chain transfer agent, and the type and amount of crosslinking agent were changed. 14 and RP-1 to RP-4 were obtained.

表２中の記号の説明
ＩＡ：イタコン酸
ＡＡ：アクリル酸
ＭＡＡ：メタクリル酸
ＮａＳＳ：スチレンスルホン酸ナトリウム
ＡＭＰＳ：２－アクリルアミド－２－メチルプロパンスルホン酸
ＳＭＡＳ：メタリルスルホン酸ナトリウム
ＭＭＡ：メタクリル酸メチル
ＥＡ：アクリル酸エチル
ＢＭＡ：メタクリル酸ｎ－ブチル
ＩＢＭＡ：メタクリル酸ｉ－ブチル
ＣＨＭＡ：メタクリル酸シクロヘキシル
ＥＨＡ：アクリル酸２－エチルヘキシル
ＬＭＡ：メタクリル酸ラウリル
ＳＡ：アクリル酸ステアリル
Ｓｔ：スチレン
ＡＡｍ：アクリルアミド
ＭＰＡＯ：メルカプトプロピオン酸２－エチルヘキシル
ＮＤＭ：ｎ－ドデシルメルカプタン
ＭＥＴ：メルカプトエタノール
ＭＳＤ：２，４－ジフェニル－４－メチル－１－ペンテン
ＨＥＧＤＡ：ヘキサエチレングリコールジアクリレート

Explanation of symbols in Table 2 IA: Itaconic acid AA: Acrylic acid MAA: Methacrylic acid NaSS: Sodium styrene sulfonate AMPS: 2-acrylamido-2-methylpropanesulfonic acid SMAS: Sodium methallylsulfonate MMA: Methyl methacrylate EA : Ethyl acrylate BMA: n-butyl methacrylate IBMA: i-butyl methacrylate CHMA: cyclohexyl methacrylate EHA: 2-ethylhexyl acrylate LMA: lauryl methacrylate SA: stearyl acrylate St: styrene AAm: acrylamide MPAO: mercaptopropion 2-Ethylhexyl acid NDM: n-dodecylmercaptan MET: Mercaptoethanol MSD: 2,4-diphenyl-4-methyl-1-pentene HEGDA: Hexaethylene glycol diacrylate

(Manufacture of paper additives)
Manufacturing example 1
A separable flask equipped with a thermometer, a cooling tube, and a stirrer was charged with 80.0 g of compound (A) M-2 obtained above, and heated to 100° C. with stirring to melt. After confirming melting, 57.1 g (solid 20.0 g) of P-1 (solid) and 1.6 g of 25% aqueous sodium hydroxide solution were added, and then 361.3 g of ion-exchanged water at 85°C was added dropwise. Phase inversion emulsification was performed by dropping the mixture using a funnel over a period of 1 hour. After the dropping was completed, the mixture was cooled to obtain paper additive E-1 having a solid content of 20%.

Production Examples 2 to 17, 19 to 22 and Comparative Production Examples 1 to 7
Paper additives E-2 to E were produced in the same manner as in Production Example 1, except that the type and amount of compound (A) and the type and amount of polymer (B) were changed as shown in Table 3. -17, E-19 to E-22 and RE-1 to RE-7 were obtained.

Production example 18
In a separable flask equipped with a thermometer, a cooling tube, and a stirrer, 85.0 g of M-5, which is the compound (A) obtained above, was charged, and the temperature was raised to 100° C. while stirring to heat and melt. After confirming melting, add 40.0 g (solid 14.0 g) of P-12 as polymer (B), 1.0 g (solid content 1.0 g) of Nucor 2360 (manufactured by Nippon Nyukazai) as a surfactant, 25 % sodium hydroxide aqueous solution was added, and then 368.8 g of 85° C. ion-exchanged water was added dropwise using a dropping funnel over 1 hour to perform phase inversion emulsification. After the dropwise addition was completed, 294.8 g of ion-exchanged water at 85° C. was added and cooled to obtain paper additive E-18 with a solid content of 20%.

Solid content of paper additives E-1 to E-22 obtained in Production Examples 1 to 22 and comparative paper additives RE-1 to RE-7 obtained in Comparative Production Examples 1 to 7, Table 3 shows the viscosity, pH, average particle diameter, presence or absence of foreign substances during production, and sedimentation stability evaluation results.
The viscosity is a value measured at 25°C using a Brookfield rotational viscometer.
The average particle diameter is the particle diameter (D50) at which the cumulative frequency of volume is 50%, as measured by a laser diffraction/scattering particle size distribution analyzer Microtrac MT3300EXII (manufactured by Microtrac Bell). The smaller the average particle diameter, the better the dispersibility.
The presence or absence of foreign matter during production was determined by the presence or absence of the filtration residue when the paper additive after production was filtered through a 150 mesh filter cloth, and was defined as ×: filtration residue present, ○: filtration residue absent. . The absence of foreign matter indicates that the dispersibility of the paper additive is better.
Sedimentation stability was determined by centrifuging 3 g of the paper additive after manufacture at a relative centrifugal acceleration of 125 G for 10 minutes using a centrifugal separator, then collecting 1 g from the liquid surface and 1 g from the bottom, and determining the solid content (%) at 150°C for 20 minutes. ) was measured, and the determination was made based on the solid content difference (%) calculated from the solid content (%) at the bottom - the solid content (%) at the liquid surface. The smaller the value of the solid content difference, the less sedimentation occurs, indicating that the storage stability of the paper additive is better. When the solid content difference was less than 3.0%, it was rated as ○, and when it was 3.0% or more, it was rated as ×.

In addition, the paper additives RE-1, RE-3, RE-4, RE-6, and RE-7 for comparative examples had a large amount of foreign matter due to poor dispersion during manufacturing, so the solid content, viscosity, and pH were measured. and sedimentation stability test was not conducted and was not evaluated as a comparative example.

(Example 1)
Hardwood bleached kraft pulp (LBKP) was beaten to a freeness of 400 ml to prepare a pulp slurry with a pulp concentration of 2.5%. While stirring this pulp slurry, 0.4% by mass of the paper additive E-1, 1.5% by mass of sulfuric acid, and 0.0% of cationized starch were added to the solid mass of the pulp. A paper stock was prepared by adding CC1401 (manufactured by Seiko PMC) as a rosin sizing agent to a solid content of 5% by mass, and adding light calcium carbonate to a solid content of 16% by mass. Using this stock, paper was made using a square sheet machine to obtain handmade paper with a basis weight of 80 g/m2. After conditioning the obtained handmade paper for 24 hours at 23°C and 50% relative humidity, the density, sizing, specific volume, specific volume improvement, and foamability test were measured and calculated using the following methods. . The value of the specific volume improvement degree is a value that is an index of the paper thickness improvement effect, and the higher the value, the higher the paper thickness improvement effect. Table 4 shows the results of specific volume improvement and size.

Sizing... JISP8122 Steckigt Sizing Test Method for Paper Density... JISP8118 Paper and Paperboard - Test Method for Thickness and Density Specific Volume... Reciprocal of Density Specific Volume Improvement Rate... "(Specific Volume)/(No Additives for Paper) Specific volume in case of *) x 100-100"
*In Tables 4, 5, and 6, the specific volume foamability test for Reference Examples 1, 2, and 3, respectively...The same paper stock as the paper stock before papermaking in Example 1 was mixed with tap water at pH 7.5 to a pulp density of 0. It was diluted to 25% and placed in a cylindrical container. A part of the pulp slurry in a cylindrical container was circulated by a pump and dropped into the container from a height of 1 m for 10 minutes, and after 10 minutes, the liquid surface covered with bubbles was compared to the entire liquid surface. Judgment was made based on the area ratio based on the following criteria.
×: The liquid surface area covered with bubbles is 50% or more of the whole, and foaming is likely to occur.
Δ: The liquid surface area covered with bubbles is 10% or more and less than 50% of the whole, and there is some foaming.
○: The liquid surface area covered with bubbles is less than 10% of the whole, and foaming is suppressed.
Regarding the foamability, values of ○ to △ are at a practical level.

(Examples 2-22, Comparative Examples 1-2)
The specific volume improvement and sizing of handmade paper obtained in the same manner as in Example 1 except that the type of paper additive was changed as shown in Table 4 was measured, and a foamability test was conducted. The results are shown in Table 4.

(Reference example 1)
A handmade paper obtained in the same manner as in Example 1 except that no paper additive was added in Example 1 was measured for specific volume improvement and sizing, and a foamability test was conducted. The results are shown in Table 4.

(Example 23)
Hardwood bleached kraft pulp (LBKP) was beaten to a freeness of 400 ml to prepare a pulp slurry with a pulp concentration of 2.5%. While stirring this pulp slurry, 0.4% by mass of the paper additive E-1, 0.5% by mass of sulfuric acid, and 0.5% by mass of cationized starch were added to the solid mass of the pulp. A paper stock was prepared by adding AD1614 (manufactured by Seiko PMC) as an AKD sizing agent to 0.08 solid mass %, and light calcium carbonate to 16 solid mass %. Using this stock, paper was made using a square sheet machine to obtain handmade paper with a basis weight of 80 g/m ² . After conditioning the obtained handmade paper for 24 hours at 23°C and 50% relative humidity, the density, sizing, specific volume, and specific volume improvement were measured and calculated using the same method as in Example 1. , a foamability test was conducted. Table 5 shows the specific volume improvement, sizing, and foamability test results.

(Examples 24-44, Comparative Examples 3-4)
The specific volume improvement and sizing of handmade paper obtained in the same manner as in Example 23 except that the type of paper additive was changed as shown in Table 5 was measured, and a foamability test was conducted. The results are shown in Table 5.

(Reference example 2)
A handmade paper obtained in the same manner as in Example 23 except that no paper additive was added was measured for specific volume improvement and sizing, and a foamability test was conducted. The results are shown in Table 5.

(Example 45)
Hardwood bleached kraft pulp (LBKP) was beaten to a freeness of 400 ml to prepare a pulp slurry with a pulp concentration of 2.5%. While stirring this pulp slurry, 0.4% by mass of the paper additive E-1, 0.5% by mass of sulfuric acid, and 0.5% by mass of cationized starch were added to the solid mass of the pulp. Paper was prepared by adding AS1530 (manufactured by Seiko PMC) emulsified with a cationized starch paste liquid as an ASA sizing agent to a solid content of 0.1% by mass, and light calcium carbonate to a solid content of 16% by mass. A sample was prepared. Using this stock, paper was made using a square sheet machine to obtain handmade paper with a basis weight of 80 g/m ² . After conditioning the obtained handmade paper for 24 hours at 23°C and 50% relative humidity, the density, sizing, specific volume, and specific volume improvement were measured in the same manner as in Example 1, and the foamability was determined. A test was conducted. Table 6 shows the specific volume improvement, sizing, and foamability test results.

(Examples 46-66, Comparative Examples 5-6)
The specific volume improvement and sizing were measured for handmade paper obtained in the same manner as in Example 45, except that the type of paper additive was changed as shown in Table 6, and a foamability test was conducted. The results are shown in Table 6.

(Reference example 3)
A handmade paper obtained in the same manner as in Example 45 except that no paper additive was added was measured for specific volume improvement and sizing, and a foamability test was conducted. The results are shown in Table 6.

Comparison of Production Examples 1 to 22 and Comparative Production Example 1 shows that when the amount of polymer (B) is smaller than the range of compound (A):polymer (B) = 99 to 70:1 to 30, compound (A) becomes less effective in water. It can be confirmed that the dispersion was not sufficiently stabilized and a large amount of aggregates were generated during the production of the paper additive.

From the comparison between Production Examples 1 to 22 and Comparative Production Example 2, Examples 1 to 22 and Comparative Example 1, Examples 23 to 44 and Comparative Example 3, and Examples 45 to 66 and Comparative Example 5, Compound (A) : Polymer (B) = 99 to 70: When the amount of Polymer (B) is larger than the range of 1 to 30, the excess Polymer (B) from emulsification dispersion deteriorates the sedimentation stability of the paper dispersant, and the paper making process deteriorates. It can be confirmed that foaming occurs within the system.

From the comparison between Production Examples 1 to 22 and Comparative Production Example 3, it can be confirmed that when urea (a-3) is not used in compound (A), a large amount of aggregates are generated during the production of paper additives. .

From the comparison between Production Examples 1 to 22 and Comparative Production Example 4, when the anionic monomer (b-1) in the polymer (B) is smaller than the range of 3 to 20 mol%, the anionicity of the polymer (B) is insufficient. As a result, it can be confirmed that compound (A) is not sufficiently dispersed and stabilized in water, and a large amount of aggregates are produced during the production of paper additives.

From the comparison between Production Examples 1 to 22 and Comparative Production Example 5, Examples 1 to 22 and Comparative Example 2, Examples 23 to 44 and Comparative Example 4, and Examples 45 to 66 and Comparative Example 6, polymer (B) In (b-1), if the amount of the anionic monomer is larger than the range of 3 to 20 mol%, the anionic property of the polymer (B) becomes excessive, which deteriorates the sedimentation stability of the paper additive, and It can be seen that the effect of improving paper thickness cannot be obtained and foaming increases.

From Production Examples 1 to 22 and Comparative Production Example 6, it is clear that when the amount of hydrophobic monomer (b-2) in the polymer (B) is less than 5 to 15 mol%, the hydrophobicity of the polymer (B) is insufficient. It can be confirmed that a large amount of aggregates are produced during the production of paper additives.

From Production Examples 1 to 22 and Comparative Production Example 7, in polymer (B), (b-1) the anionic monomer is in a larger amount than the range of 3 to 20 mol%, and (b-2) the hydrophobic monomer is in the range of 5 to 15% by mole. If the amount exceeds the mol% range, it can be confirmed that a large amount of aggregates are produced during the production of paper additives.

Claims (5)

It contains the following compound (A) and the following (meth)acrylamide-based polymer (B), and the mass ratio of the compound (A) and the (meth)acrylamide-based polymer (B) is (A):(B) = 99 to 70. A paper additive characterized in that: :1 to 30.
Compound (A):
Reaction product of polyalkylene polyamine (a-1) having 3 to 5 amino groups in one molecule, monovalent fatty acid (a-2) with 8 to 22 carbon atoms, and urea (a-3) (Meth)acrylamide polymer (B):
(b-1) anionic monomer, (b-2) hydrophobic monomer, and (b-3) (meth)acrylamide, (b-1):(b-2):(b-3)= Polymer of monomers containing in a ratio of 3 to 20:5 to 15:65 to 92 (mol%) (b-2) The paper additive according to claim 1, wherein the hydrophobic monomer is an alkyl (meth)acrylate having an alkyl group or a cycloalkyl group having 1 to 20 carbon atoms. (b-1) The paper additive according to claim 1, wherein the anionic monomer is at least one selected from a monomer having a carboxyl group, a monomer having a sulfonic acid group, and a salt thereof. . The paper additive according to any one of claims 1 to 3, which is a paper thickness improver. A paper characterized by containing the paper additive according to any one of claims 1 to 4.