JP5501889B2 - Coating composition and coated paper - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a coating composition and coated paper, and more particularly to a coating composition and coated paper used for preventing back-through after printing.

  In recent years, there has been an increasing demand for printing paper in the commercial printing field for the purpose of advertising and advertising such as flyers, catalogs, pamphlets and direct mail. Although these commercial printed materials have low commercial value, it is important that the purpose is achieved as an advertising medium, and therefore, there is a demand for low-cost and high-quality printed products. Particularly in the field of mail-order catalogs, paper used for cost reduction is also becoming lighter. However, as the weight is reduced, the show-through after printing becomes a problem. Therefore, a paper having a low basis weight and less show-through after printing is required.

  In order to obtain paper with little show-through after printing, use of fillers with a large specific surface area (white carbon, fine powder silica, etc.), fillers with high refractive index, pigments (titanium dioxide, etc.), and bulky coating layers Methods of using pigments to be formed (plastic pigments, delaminated clays, etc.) and increasing the amount of mechanical pulp used are being studied. In general, however, these fillers and pigments are expensive and tend to increase the viscosity of the coating solution, resulting in poor operability.

  In addition, as a technique for improving paper opacity in order to obtain paper with less show-through after printing, “addition of basic amides of long-chain fatty acids or fatty acid mixtures having a melting point of 30 ° C. or lower to papermaking raw materials” Obtained by reacting a compound such as an amide compound represented by a specific structural formula with an epihalohydrin (see, for example, the claims of Patent Document 1). It has been proposed to use a paper opacifier characterized by containing a compound (see, for example, Patent Document 2), but these opacity improvers thicken the paper by interaction with pulp. The opacity can be improved, and the opacity is improved, but a paper with little show-through after printing cannot be obtained, and a coating composition using a pigment as a main component is used. And it suggests there is no description on the Prevention strike-through of ink in.

JP 61-252400 A JP 2000-273792 A

  The subject of this invention is providing the composition for coating which can manufacture the coated paper with a high value of oil absorption, and suppressing the penetration | permeation of an ink and there are few show-throughs after printing. Moreover, this invention makes it a subject to provide the coated paper with few back-throughs after printing manufactured using this composition for coating.

  As a result of diligent research to solve the above-mentioned problems, the present inventors can obtain a specific amide compound by modifying with a specific proportion of epihalohydrin in an aqueous solution containing a specific organic acid and a specific emulsifier. It has been found that the above problems can be solved by using an amino compound [B], and the present invention has been completed.

That is, the present invention, which is a means for solving the above problems,
(1) A coating composition comprising the following (I) to (III):
(I) 5 to 45 mol% of dibasic carboxylic acid (b) and polyalkylene polyamine (a) based on the number of moles of primary amino group contained in polyalkylene polyamine (a) and polyalkylene polyamine (a) The amine value obtained by reacting 25 to 85 mol% of fatty acids (c) having 12 to 24 carbon atoms with respect to the total number of moles of primary amino groups and secondary amino groups contained in a) 20 to 150 mgKOH / g of the amide compound [A] is dissolved in an aqueous solution containing the water-soluble organic acid (d) and the nonionic emulsifier and / or the cationic emulsifier (e). Amino compound [B] obtained by reacting with 50 to 100 mol% of epihalohydrin (f) based on the remaining amino group
(II) Pigment (III) Adhesive (2) The amount of the water-soluble organic acid (d) is 1 to 20 mol% based on the residual amino group of the amide compound [A], and the nonionic emulsifier and The composition for coating according to claim 1, wherein the amount of the cationic emulsifier (e) is 1 to 20% by mass relative to the amide compound [A].
(3) The composition for coating according to claim 1 or 2, wherein the fatty acid (c) is a saturated fatty acid.
(4) The amino compound [B] is contained in an amount of 0.05 to 10 parts by mass with respect to 100 parts by mass of the pigment in a solid content ratio. Composition for coating,
(5) A coated paper comprising a base paper surface having a coating layer made of the coating composition according to any one of claims 1 to 4.

  According to the present invention, it is possible to provide a coating composition and coated paper that suppresses the permeation of ink after printing and has little show-through.

The coating composition according to the present invention contains the following (I) to (III).
(I) 5 to 45 mol% of dibasic carboxylic acid (b) and polyalkylene polyamine (a) based on the number of moles of primary amino group contained in polyalkylene polyamine (a) and polyalkylene polyamine (a) The amine value obtained by reacting 25 to 85 mol% of fatty acids (c) having 12 to 24 carbon atoms with respect to the total number of moles of primary amino groups and secondary amino groups contained in a) 20 to 150 mgKOH / g of the amide compound [A] is dissolved in an aqueous solution containing the water-soluble organic acid (d) and the nonionic emulsifier and / or the cationic emulsifier (e). Amino compound [B] obtained by reacting with 50 to 100 mol% of epihalohydrin (f) based on the remaining amino group
(II) Pigment (III) Adhesive

  First, the amide compound [A] that is a raw material of the amino compound [B] will be described. This amide-based compound [A] is a dibasic carboxylic acid (b) of 5 to 45 mol% with respect to the number of moles of primary amino group contained in the polyalkylene polyamine (a) and the polyalkylene polyamine (a). And 25 to 85 mol% of fatty acids (c) having 12 to 24 carbon atoms with respect to the total number of moles of primary amino groups and secondary amino groups contained in the polyalkylene polyamine (a). Can be obtained.

The polyalkylene polyamine (a) used in the present invention is a compound capable of forming an amide compound [A] by reacting with a dibasic carboxylic acid (b) and a fatty acid having 12 to 24 carbon atoms (c). For example, a compound having a plurality of repeating units represented by — (— R—NH —) — (R is an alkylene group), and the like can be given. The “alkylene group R” in the polyalkylene polyamine (a) is preferably a lower alkylene group, specifically, preferably an alkylene group having 2 to 6 carbon atoms, and an alkylene having 2 to 4 carbon atoms. More preferably, it is a group. Examples of such polyalkylene polyamine (a) include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, dipropylenetriamine, tripropylenetetramine, iminobispropylamine, and amines thereof. An alkylene oxide adduct of Among these, a polyethylene polyamine represented by NH ₂ — (— CH ₂ CH ₂ —NH—) _n —H (where n is an integer of 2 to 8) is preferable, and diethylenetriamine, triethylenetetramine, tetraethylene are preferred. Pentamine is preferred, and tetraethylenepentamine is particularly preferred. These may be used alone or in combination of two or more. Further, a part of the polyalkylene polyamine (a) can be used in place of a diamine such as ethylenediamine or hexamethylenediamine.

  The dibasic carboxylic acid (b) used in the present invention is a dibasic carboxylic acid having two carboxy groups in the molecule, or a functional group and / or a carboxy group capable of generating a carboxy group. A dibasic carboxylic acid derivative having a total of two in the molecule, and reacting with the polyalkylene polyamine (a) to produce an amide compound [A] having an amide bond (—CO—NH—) in the molecule It is a compound that can be formed. Examples of the functional group that generates a carboxy group include an ester group and an acid anhydride group that generate a carboxy group by a chemical reaction such as hydrolysis. Examples of the dibasic carboxylic acid derivative include monoesters, diesters, and acid anhydrides of dibasic carboxylic acids. In the present invention, the dibasic carboxylic acid (b) includes a dibasic carboxylic acid, a diester of a dibasic carboxylic acid, a diester of a dibasic carboxylic acid, and an acid anhydride of a dibasic carboxylic acid. The at least 1 sort selected from more is mentioned. Examples of the dibasic carboxylic acid include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, brassylic acid, dodecanedioic acid, terephthalic acid, and the like. A dibasic carboxylic acid having a number of 5 to 10 is preferred. The dibasic carboxylic acid monoester or diester is preferably a lower alkyl (methyl, ethyl, propyl) ester having 1 to 5 carbon atoms, particularly preferably 1 to 3 carbon atoms, of the dibasic carboxylic acid. Can be mentioned. Examples of the acid anhydride include a condensate of the dibasic carboxylic acid with an intramolecular dehydration condensate of a free acid, a lower carboxylic acid, preferably a C 1-5 lower carboxylic acid, and the like. Particularly preferred dibasic carboxylic acids (b) include adipic acid, sebacic acid, terephthalic acid, glutaric acid dimethyl ester, and adipic acid dimethyl ester. The dibasic carboxylic acids can be used alone or in combination of two or more.

  It is important that the dibasic carboxylic acid (b) is used in an amount of 5 to 45 mol% based on the number of moles of the primary amino group contained in the polyalkylene polyamine (a). When less than 5 mol% of the dibasic carboxylic acid (b) is reacted with respect to the number of moles of the primary amino group contained in the polyalkylene polyamine (a), the oil absorption is low, When the dibasic carboxylic acid (b) is reacted in excess of 45 mol%, the oil absorption value is low, and the effect of preventing the back-through after printing may be inferior. May not be able to produce the amino compound [B] as a uniform dispersion or solution.

  The C12-24 fatty acid (c) used in the present invention reacts with the polyalkylene polyamine (a) to form an amide bond (-CO-NR'-, R 'is a hydrogen atom or Carboxylic acid or ester thereof that can form an amide compound [A] having the repeating unit -RNH-). The fatty acids (c) may be saturated or unsaturated, and specifically include dodecanoic acid having 12 carbons (lauric acid), tetradecanoic acid having 14 carbons (myristic acid), carbon Number 15 pentadecanoic acid (pentadecylic acid), carbon number 16 hexadecanoic acid (palmitic acid), 9-hexadecenoic acid (palmitoyl acid), carbon number 17 heptadecanoic acid (margaric acid), carbon number 18 octadecanoic acid (stearic acid) ), Cis-9-octadecenoic acid (oleic acid), 11-octadecenoic acid (vaccenic acid), cis, cis-9,12-octadecadienoic acid (linoleic acid), 9,12,15-octadecantrienoic acid (( 9,12,15) -linolenic acid), 6,9,12-octadecatrienoic acid ((6,9,12) -linolenic acid), 9,11,1 -Octadecatrienoic acid (eleostearic acid), 19-carbon nonadecanoic acid (tuberculostearic acid), 20-carbon icosanoic acid (arachidic acid), 8,11-icosadienoic acid, 5,8,11-icosatriene Examples include acid, 5,8,11-icosatetraenoic acid (arachidonic acid), 22 carbon docosanoic acid (behenic acid), 24 carbon tetradocosanoic acid (lignoceric acid), cis-15-tetradocosanoic acid (nervonic acid). Even these esters can be used. The number of carbon atoms of the fatty acids (c) is important to be 12 to 24 in that the amide compound [A] and the amino compound [B] can exhibit suitable hydrophobicity. 12 to 22 is preferable. Among these, saturated fatty acids are preferable, and stearic acid having 18 carbon atoms is particularly preferable. Said fatty acid (c) can be used 1 type or in combination of 2 or more types.

  The fatty acids (c) having 12 to 24 carbon atoms should be used in an amount of 25 to 85 mol% based on the total number of moles of primary amino groups and secondary amino groups contained in the polyalkylene polyamine (a). Preferably, it is 25-70 mol%. When the fatty acid (c) having 12 to 24 carbon atoms of less than 25 mol% is used with respect to the total number of primary amino groups and secondary amino groups contained in the polyalkylene polyamine (a), the oil absorption The value is low and the effect of preventing see-through after printing is inferior. When the fatty acid (c) having more than 85 mol% and having 12 to 24 carbon atoms is used, the oil absorption value is low, and the effect of preventing see-through after printing is obtained. May be inferior, and in some cases, the amino compound [B] may not be produced.

  The reaction of the polyalkylene polyamine (a) with the fatty acids (c) and the dibasic carboxylic acids (b) is usually performed by heating to 100 to 200 ° C. The reaction time is usually 0.5 to 10 hours, and preferably 2 to 6 hours. There is no limitation on the method of mixing the polyalkylene polyamine (a) with the fatty acids (c) and the dibasic carboxylic acids (b) during the reaction, and usually the polyalkylene polyamine (a) is mixed with the dibasic carboxylic acids (b). A method in which the reaction is proceeded by mixing the fatty acid (c) with the fatty acid (c), and the reaction is proceeded by mixing the fatty acid (c) with the reaction product of the dibasic carboxylic acid (b) and the polyalkylene polyamine (a). The method is preferred. A catalyst for the amidation reaction is not particularly required. However, as the catalyst for the amidation reaction, sulfonic acids such as sulfuric acid, benzenesulfonic acid and paratoluenesulfonic acid, or a catalyst usually used for the amidation reaction are used. May be. The amount used is usually 0.005 to 0.1 mol, preferably 0.01 to 0.05 mol, per 1 mol of polyalkylene polyamine (a).

The amide compound [A] in the present invention is an amide compound having an amide group formed by a reaction of an amino group and a carboxy group, and is usually a polyalkylene polyamine (a), a dibasic carboxylic acid (b) and a fatty acid. (C) is produced by a condensation reaction at the molar ratio. This amide compound [A] is a reaction product (A1) of a polyalkylene polyamine (a) and a dibasic carboxylic acid (b), or a reaction product of a polyalkylene polyamine (a) and a fatty acid (c). (A2) and a mixture of polyalkylene polyamine (a), dibasic carboxylic acid (b) and fatty acid (c) reaction product (A3) and not a single compound, but the molar ratio The reaction product (A3) is the main reaction product because of the condensation reaction. The reaction product (A1) of the polyalkylene polyamine (a) and the dibasic carboxylic acid (b) itself is not a single compound, but a mixture of the polyalkylene polyamine (a) and the fatty acids (c). The reaction product (A2) itself is also a mixture, and the reaction product (A3) itself of the polyalkylene polyamine (a), the dibasic carboxylic acid (b) and the fatty acid (c) is also a mixture. Therefore, the amide compound [A] itself is not a single compound but a mixture of a plurality of types of amide compounds having a common chemical structure called an amide group, and it is difficult to specify the composition itself.
Although it is difficult to specify the structure and composition, this amide compound [A] has an unreacted amino group (sometimes referred to as “residual amino group” in the present invention), and therefore serves as an index. Characterized by amine value. It is important that the amine value of the amide compound [A] is 20 to 150 mgKOH / g. If the amine value is less than 20, the oil absorption value is low, and if the amine value exceeds 150, the oil absorption value is low. The amine value of the amide compound [A] is within the above range by appropriately selecting the use ratio and reaction temperature of the polyalkylene polyamine (a), the dibasic carboxylic acid (b) and the fatty acid (c). Can be adjusted.

The amine value of the amide compound [A] in the present invention is expressed in milligrams of the amount of potassium hydroxide equivalent to hydrochloric acid necessary for neutralizing the amine contained in 1 g of the solid content of the amide compound [A]. It is the displayed numerical value, and the measuring method of the amine value is as follows.
The collected sample is carefully evaluated, and isopropyl alcohol is added and dissolved, and titrated with a 1/2 N hydrochloric acid methanol solution to pH 5, and the amine value is determined from the following formula.
Amine number = (V × F × 0.5 × 56.1) / S
However, V: titration amount of 1/2 N hydrochloric acid methanol solution (cc)
F: titer of 1/2 N hydrochloric acid methanol solution S: solid content of collected sample (g)
The amount (mmol) of the residual amino group of the amide compound [A] in the present invention can be determined by the following formula from the amine value as the number of millimoles of amine contained in 1 g of solid content.
Amount of residual amino groups (mmol) = Amine number / 56.1

The amino compound [B] of the present invention is an amide compound in an aqueous solution containing the amide compound [A] and a water-soluble organic acid (d) and a nonionic emulsifier and / or a cationic emulsifier (e). It can be obtained by reacting 50 to 100 mol% of epihalohydrin (f) with respect to the residual amino group of [A].
This amino compound [B] is a mixture of a plurality of types of compounds having an amino group since the amide type compound [A] is a mixture of a plurality of types of compounds having an amino group. Although this amino compound [A] can be specified by a structure having an amino group, it is difficult to specify the composition and content of plural kinds of amino compounds. Therefore, this amino compound [B] must be specified by the production method description.

  The water-soluble organic acid (d) used in the present invention is an organic acid having water-solubility, that is, a water-miscible property or a water-soluble property, for example, a monovalent water solution having 1 to 3 carbon atoms. Carboxylic acid. Examples of the water-soluble carboxylic acid include monovalent water-soluble carboxylic acids having a carboxy group such as formic acid, acetic acid, and propionic acid.

  The water-soluble organic acid (d) is preferably 1 to 20 mol%, more preferably 5 to 15 mol% with respect to the residual amino group of the amide compound [A]. It is preferable to form a salt in order to increase the dispersibility during the production of the amino compound [B].

  The nonionic emulsifier and / or the cationic emulsifier (e) used in the present invention can improve the dispersibility of the amino compound [B] to be produced, and thus the amide compound [A] and the epihalohydrin (f). It is suitably used for the reaction. Among such nonionic emulsifiers and / or cationic emulsifiers (e), examples of the nonionic emulsifier include fatty acid sorbitan esters and fatty acid polyglycol esters in which the alkyl group and / or alkenyl group has 4 to 20 carbon atoms. , Fatty acid amides, and various polyalkylene oxide type nonionic surfactants. Polyalkylene oxide type nonionic surfactants include fatty acid alkylene oxide sorbitan esters, polyoxyalkylene fatty acid esters, polyoxyalkylene fatty acid amides, polyoxyalkylene fatty alcohols, polyoxyalkylene aliphatic amines, polyoxyalkylene aliphatic mercaptans. , Polyoxyalkylene alkyl ether, polyoxyalkylene alkyl aryl ether and the like. Among these, an alkylene oxide adduct excellent in emulsifying dispersibility is preferable, and 1 to 20 mol of an alkylene oxide is preferably added per molecule of the emulsifier. It is particularly preferable that the alkyl group of the alkylene oxide has 2 to 4 carbon atoms.

  Of the nonionic emulsifier and / or the cationic emulsifier (e) used in the present invention, examples of the cationic emulsifier include a long-chain alkylamine salt having 4 to 20 carbon atoms in the alkyl group and / or alkenyl group. , Polyoxyalkyleneamine, tetraalkyl quaternary ammonium salt, trialkylbenzyl quaternary ammonium salt, alkylimidazolium salt, alkylpyridinium salt, alkylquinolium salt, alkylphosphonium salt, alkylsulfonium salt, and the like. Among these, an alkylene oxide adduct excellent in emulsifying dispersibility is preferable, and 1 to 20 mol of an alkylene oxide is preferably added per molecule of the emulsifier. It is particularly preferable that the alkyl group of the alkylene oxide has 2 to 4 carbon atoms.

  The nonionic emulsifier and / or the cationic emulsifier (e) is used in an amount of 1 to 20% by mass based on the solid content of the amide compound [A], while suppressing foaming, and the amino compound [B ] Is preferable for enhancing the dispersibility. A part of the nonionic emulsifier and / or the cationic emulsifier (e) may be used instead of the amphoteric emulsifier.

  Examples of the epihalohydrin (f) used in the present invention include epichlorohydrin, epibromohydrin, etc. Among them, epichlorohydrin is preferable.

  It is important that the amount of the epihalohydrin (f) used is 50 to 100 mol%, preferably 60 to 80 mol%, based on the remaining amino group of the amide compound [A].

When the amount of epihalohydrin (f) used is less than 50 mol% with respect to the remaining amino group of the amide compound [A], the viscosity of the amino compound [B] increases, and the dispersibility in the coating composition is increased. Therefore, the oil absorption value is low, and the effect of preventing the see-through after printing is inferior. If it exceeds 100 mol%, the amount of unreacted substances increases.
The water-soluble organic acid (d) and the nonionic emulsifier and / or cationic emulsifier (e) may be dissolved in water. In this case, the water used is preferably pure water or ion-exchanged water.

The reaction of the amide compound [A] and the epihalohydrin (f) in an aqueous solution containing the water-soluble organic acid (d) and the nonionic emulsifier and / or the cationic emulsifier (e) is heated to 40 to 95 ° C. Is done. The reaction time is usually 1 to 8 hours, with 3 to 6 hours being preferred.
The amino compound [B] in the present invention is a reaction product of the amide compound [A] and the epihalohydrin (f), and more specifically, the nitrogen atom of the remaining amino group of the amide compound [A] It is a compound formed by reaction with epihalohydrin (f).
This amino compound [B] may be used in a form isolated from a reaction mixture obtained by reacting an amide compound [A] with epihalohydrin (f) in preparing a coating composition. Alternatively, the reaction mixture may be used in the form of, for example, a reaction product solution, a reaction product suspension, or a reaction product dispersion. This reaction mixture can also be used diluted or concentrated.

  There is no restriction | limiting in particular as said (II) pigment in the composition for coating which concerns on this invention, The pigment conventionally used for coated paper can be used. For example, kaolin, clay, delaminated clay, heavy calcium carbonate, light calcium carbonate, talc, titanium dioxide, barium sulfate, calcium sulfate, zinc oxide, silicic acid, silicate, colloidal silica, satin white, etc. Organic pigments such as plastic pigments, organic / inorganic composite pigments, and the like can be used. These pigments can be used alone or in combination of two or more as required. Among these, it is preferable to use one or more of kaolin, clay, delaminated clay, heavy calcium carbonate, and light calcium carbonate.

  There is no restriction | limiting in particular in the adhesive agent used by this invention, The adhesive agent (binder) conventionally used for coated paper can be used. For example, various copolymers such as styrene / butadiene, styrene / acrylic, ethylene / vinyl acetate, butadiene / methyl methacrylate, vinyl acetate / butyl acrylate, polyvinyl alcohol, maleic anhydride copolymer, acrylic acid / methyl Synthetic adhesives such as methacrylate copolymers; proteins such as casein, soy protein, synthetic proteins; etherified starches such as oxidized starch, positive starch, urea phosphated starch, hydroxyethyl etherified starch, dextrin, etc. Starch: One or more kinds of ordinary adhesives for coated paper such as cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, and hydroxymethylcellulose can be appropriately selected and used. Moreover, various auxiliary | assistant mix | blended with the pigment for normal coated papers, such as a dispersing agent, a thickener, a water retention agent, an antifoamer, a water-resistant agent, and a coloring agent, are used suitably as needed.

  The coating composition of the present invention includes amino compounds [B], pigments, adhesives, dispersants, lubricants, thickeners, thickeners, antifoaming agents, antifoaming agents, antiseptics, and antibacterial agents. Various auxiliaries such as mold agents, water retention agents, dyes, conductive agents, fluorescent dyes and pH adjusters can be appropriately blended as necessary.

The ratio of the adhesive in the coating composition of the present invention is preferably 1 to 60 parts by mass, particularly preferably 5 to 45 parts by mass with respect to 100 parts by mass of the pigment. The ratio of the compound [B] is preferably 0.05 to 10 parts by mass, particularly preferably 0.2 to 5 parts by mass with respect to 100 parts by mass of the pigment. In addition, all ratios are the solid content mass of each component.
The coating composition of the present invention only needs to contain an amino compound [B], a pigment, and an adhesive, and is preferably liquid from the viewpoint of workability. That is, the coating composition of the present invention is preferably a liquid obtained by dissolving, dispersing or suspending the amino compound [B], the pigment and the adhesive in a dispersion medium such as water. When the coating composition of the present invention is liquid, the solid content concentration of the amino compound [B], the pigment and the adhesive is preferably 15 to 70% by mass.

  In order to prepare the coating composition of the present invention, the amino compound [B], the pigment and the adhesive, and various auxiliary agents as necessary are mixed in a medium such as water so as to be uniform. Adjust the pH accordingly. At this time, the order of mixing each component is not particularly limited. As an example of a suitable method for preparing the coating composition of the present invention, for example, a pigment is dispersed in water together with a dispersant as necessary, and an amino compound [B] and an adhesive, and a viscosity as required. Examples include a method of adding an auxiliary such as a regulator and stirring, and further adjusting the pH with a pH adjuster as necessary. The amino compound [B] may be added in a powder state, or may be added in a solution or dispersion state.

  Thus, the coating composition of the present invention contains an amino compound [B], a pigment, and an adhesive, and usually a suspension in which these components are suspended or dispersed in a solvent such as water. Alternatively, it is in the form of a dispersion, ie, a coating liquid. The coating composition may have a pH in the range of 6-13.

  The coating composition according to the present invention can be used by coating or coating the surface of a base paper. Since the coating composition according to the present invention contains a pigment and is applied to the surface of the base paper, it can also be referred to as a pigment coating composition that can apply the pigment to the surface of the base paper.

The coated paper of the present invention can be produced by coating the coating composition of the present invention on the surface of a base paper by a known method and drying it. At this time, the coating amount of the coating composition of the present invention is preferably 0.5 to 15 g / m ² in terms of solid content on one side and 1 to 30 g / m ^{2 in} terms of solid content on both sides.

Examples of the base paper include various high-quality papers such as neutral papermaking using calcium carbonate as a filler, acidic papermaking using talc, etc., various paperboards made in neutral or acidic paper, and others It is suitably used for sheet synthetic paper containing inorganic fibers. Moreover, the coated paper coated with the coating composition of the present invention is suitably used as various printing papers, inkjet papers, information papers, and PPC papers. Furthermore, the base paper has a basis weight of 100 g / m ² or less, and preferably 30 g / m ^{2 to} 80 g / m ² , and can exhibit the effect of the present invention more.

  The coating composition of the present invention is usually used for blade coaters, air knife coaters, bar coaters, roll coaters, size press coaters, doctor coaters, brush coaters, curtain coaters, gravure coaters, cast coaters, and Chanplex coaters. It is coated on the base paper surface by a coating device. Moreover, any coating method of on-machine coating and off-machine coating can be applied, and it can be applied to single-layer coating or multilayer coating. Furthermore, it can be applied to both single-sided coating and double-sided coating.

Drying after coating can be performed by a commonly used apparatus such as a gas heater, an electric heater, a steam heater, an infrared heater, and a hot air heater. The base paper after drying can be given gloss through a finishing device such as a super calendar, a water calendar, or a gloss calendar, if necessary. It is also possible to adjust the humidity by a known method after the coating composition of the present invention is dried or after the gloss is imparted.
In this way, the coated paper of the present invention is obtained. Since the coated paper of the present invention is obtained by drying the coating composition of the present invention coated on at least one surface of a base paper, it is formed on at least one of the base papers with the coating composition of the present invention. It has a coating layer. This coating layer is a layer formed by applying and then drying a coating solution containing the coating composition of the present invention. This coating layer contains at least the (I) amino compound [B], the (II) pigment, and the (III) adhesive, and these contents are in the coating composition of the present invention. The ratio is basically the same.

  Examples of the present invention are shown below, but the technical scope of the present invention is not limited to these embodiments. In the following, “parts” and “%” mean “parts by mass” and “% by mass”, respectively.

Production Example 1 of Polymeric Cationic Emulsifier
170 parts of styrene, 57 parts of dimethylaminoethyl methacrylate, 3.6 parts of azobisisobutyronitrile and 68 parts of isopropyl alcohol were added to a 1 liter four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen inlet tube. Charged and held at 80 ° C. for 3 hours, then 0.2 part of asobisisobutyronitrile was charged and further held at the same temperature for 2 hours. Subsequently, 22.3 parts of 90% acetic acid and 558 parts of water were added, and isopropyl alcohol was distilled off. Thereafter, 13 parts of water and 31 parts of epichlorohydrin as a quaternizing agent were charged and held for 2 hours. Then, it diluted with water so that it might become solid content 25%, and obtained cationic copolymer aqueous solution. This is used as a cationic emulsifier.

(Production Example 1 of Amino Compound)
A 1-liter four-necked round bottom flask equipped with a thermometer, cooler, stirrer, and nitrogen inlet tube is charged with 1 mol of tetraethylenepentamine and 0.6 mol of adipic acid, and the temperature is raised to 170 ° C. After removing the water to be reacted for 2 hours, 2.6 mol of stearic acid was further added and reacted at 180 ° C. for another 6 hours. Table 1 shows the results obtained by measuring the amine value of the amide compound [A] thus obtained according to the above.
50.0 g of this amide compound [A], 2.5 g of isopropyl alcohol, 369.1 g of water, 5.0 g of nonionic emulsifier (Newcol 2320 (manufactured by Nippon Emulsifier Co., Ltd.)), acetic acid as water-soluble organic acid (d) 0.4 g was charged into a 500 ml four-necked flask equipped with a thermometer, reflux condenser, stirrer, and dropping funnel, heated to 50 ° C., and stirred for 1 hour. After adding 4.2 g of epichlorohydrin (70 mol% with respect to the remaining amino group of the amide compound), the mixture was reacted at 50 ° C. for 3 hours and further at 80 ° C. for 3 hours, and then cooled to a solid content (concentration) of 15 % Of a reaction product solution of amino compound [B1] was obtained. Table 2 shows the properties of the reaction product solution of the resulting amino compound [B1]. The viscosity is a value measured at 25 ° C. and 60 rpm using a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd .: model BM type). The pH is a value measured at 25 ° C. using a glass electrode type hydrogen ion concentration meter (manufactured by Tokyo Denki Kogyo Co., Ltd.).

Production Examples 2 to 23 for amino compounds, Comparative Production Examples 1 to 10 for amino compounds
Amino compounds [B2] to [B24] and [b1] to [b10] were obtained in the same manner as in Production Example 1, except that the changes were made as shown in Table 1. Table 2 shows the properties of the resulting amino compounds [B2] to [B24] and [b1] to [b6]. Amino compounds [b7] to [b10] could not be evaluated because the amino compounds were separated.

Explanation of Abbreviations in Table 1 TEPA: Tetraethylenepentamine TETA: Triethylenetetramine DETA: Diethylenetriamine N2320: New Coal 2320 (manufactured by Nippon Emulsifier Co., Ltd.) (Type: p-EO-C12-13 ether: Polyoxyethylene alkyl ether) )
Esomine T25: polyoxyethylene alkylamine (manufactured by Lion Akzo Co., Ltd.) (type: p-EO-C14-18 amine)
Polymer: Cationic emulsifier obtained in Production Example 1 of polymer cationic emulsifier N2360: New Coal 2360 (manufactured by Nippon Emulsifier Co., Ltd.) (Type: p-EO-C12-13 ether: polyoxyethylene alkyl ether)
N1820: New Coal 1820 (Nippon Emulsifier Co., Ltd.) (Type: p-EO-C18 ether: Polyoxyethylene alkyl ether)
N2320-SN: New Coal 2320-SN (manufactured by Nippon Emulsifier Co., Ltd.) (type: p-EO-C12-13 ether: polyoxyethylene alkyl ether sulfate sodium salt) (anionic emulsifier)
EpiCl: Epichlorohydrin molar ratio: A ratio when the polyalkylene polyamine is 1 mol.
mol%: In dibasic carboxylic acids (b), it indicates the molar ratio of the polyalkylene polyamine (a) to the primary amino group, and in the fatty acids (c) having 12 to 24 carbon atoms, the polyalkylene polyamine (a) The molar ratio with respect to the total number of moles of the primary amino group and the secondary amino group is shown. In the water-soluble organic acid (d) and epihalohydrin (f), the molar ratio with respect to the remaining amino group of the amide compound is shown.

Preparation of coating composition (Examples 1 to 24, Comparative Examples 1 to 6)
Using the amino compounds obtained in Production Examples 1 to 24 of amino compounds and Comparative Production Examples 1 to 6 of amino compounds, the ratios of the solid content conversion shown below for pigments, adhesives, and other agents Then, the solid content concentration and pH are adjusted using water and a 30% aqueous sodium hydroxide solution so that the solid content concentration is 60% and the pH is 9.5 to obtain a coating composition. It was.
<Pigment>
Calcium carbonate: FMT-97 (manufactured by Pimatech) 100 parts by mass <Adhesive>
Latex: JSR-0695 (manufactured by JSR Corporation) 6 parts by mass Starch: Solar eclipse MS-4600 (manufactured by Nippon Shokuhin Kako Co., Ltd.) 3 parts by mass <amino compound>
Amino compound obtained in Examples 1 to 24 and Comparative Examples 1 to 6 1 part by mass <Others>
Antifoaming agent: SN deformer 777 (manufactured by Sannopco Corporation) 0.05 parts by mass Lubricant: DEF-963 (manufactured by Nissin Chemical Laboratory Co., Ltd.) 0.1 parts by mass fluorescent dye: Kayaphor HBC Liquid (Nippon Kayaku Co., Ltd.) Made)
0.1 parts by mass

Evaluation of coated paper Each of the coating compositions of Examples 1 to 24 and Comparative Examples 1 to 6 thus obtained was used on one side of a base paper having a basis weight of 47.7 g / m ² using a wire bar. The coating was applied so that the coating amount in terms of solid content was 6 g / m ^2, and immediately after coating, it was dried with hot air at 230 ° C. for 7 seconds. Next, humidity was adjusted for 24 hours at a temperature of 20 ° C. and a relative humidity of 50%, and further, calendar treatment was performed four times under the conditions of a roll temperature of 60 ° C. and a linear pressure of 98 N / m to obtain a coated paper. The resulting coated paper was conditioned for 24 hours at a temperature of 20 ° C. and a relative humidity of 50%, and then evaluated for oil absorption and penetration. The results are shown in Table 3. Specific test methods are as follows.

Oil absorption: JAPAN TAPPI No. In accordance with 32-2, a petroleum solvent (manufactured by Nippon Oil Corporation; AF Solvent 7) is dropped onto the surface of the coating layer formed on the surface of the base paper, and the droplets are absorbed by the coating layer and coated. The time until it disappeared on the surface of the layer was measured. The dripping amount of the liquid was 1 μL. The higher the value, the more difficult the petroleum solvent penetrates into the coating layer. In addition, it can be judged that there is a significant difference when there is a difference of 10 seconds or more in the oil absorption as a comparison reference.

Back-through: Coating of base paper using heat set-off wheel ink (DIC Corporation, WEB WORLD NEW ADVAN) using RI printing tester (manufactured by IHI machine system: RI-1 type) Printing was performed on the layer surface side, and drying was performed at 110 ° C. for 5 minutes. Immediately after drying, the back-through condition was visually evaluated. The evaluation criteria are as follows.
◎ = Very good, ○ = Good, △ = Slightly inferior, X = Inferior

  From the results shown in Table 3, the coated paper having a coating layer formed by applying the coating composition of the present invention to the surface of the base paper has a high oil absorption value and is difficult to break through. That is, the coated paper of the present invention can suppress the penetration of the ink into the base paper by forming a coating layer on the surface of the base paper to suppress the penetration of the ink into the base paper. It can be seen that the show-through after printing is less likely to occur. As described above, the coating composition of the present invention can suppress the penetration of ink into the base paper, and can prevent the see-through after printing when applied to the base paper. Furthermore, even if the coating composition of the present invention contains a pigment as a main component, it can suppress the penetration of ink into the base paper, and the coating composition of the present invention containing such a pigment as the main component. The coated paper of the present invention comprising the working composition is substantially free from back-through after printing.

Claims (5)

A coating composition comprising the following (I) to (III):
(I) 5 to 45 mol% of dibasic carboxylic acid (b) and polyalkylene polyamine (a) based on the number of moles of primary amino group contained in polyalkylene polyamine (a) and polyalkylene polyamine (a) The amine value obtained by reacting 25 to 85 mol% of fatty acids (c) having 12 to 24 carbon atoms with respect to the total number of moles of primary amino groups and secondary amino groups contained in a) 20 to 150 mgKOH / g of the amide compound [A] is dissolved in an aqueous solution containing the water-soluble organic acid (d) and the nonionic emulsifier and / or the cationic emulsifier (e). Amino compound [B] obtained by reacting with 50 to 100 mol% of epihalohydrin (f) based on the remaining amino group
(II) Pigment (III) Adhesive   The amount of the water-soluble organic acid (d) is 1 to 20 mol% with respect to the remaining amino group of the amide compound [A], and the amount of the nonionic emulsifier and / or the cationic emulsifier (e) is The composition for coating according to claim 1, wherein the content is 1 to 20% by mass relative to the amide compound [A].   The composition for coating according to claim 1 or 2, wherein the fatty acid (c) is a saturated fatty acid.   The coating composition according to any one of claims 1 to 3, wherein 0.05 to 10 parts by mass of the amino compound [B] is contained at a solid content ratio with respect to 100 parts by mass of the pigment. Composition.   A coated paper comprising a coating layer comprising the coating composition according to any one of claims 1 to 4 on a base paper surface.