JP2014034733A - Composition for paper coating and resin for paper coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for paper coating and a resin for paper coating, capable of improving ink receptivity, wet pick and air permeability of a coated paper by using a composition for paper coating having 90 to 100 mass% of calcium carbonate in a pigment, and having no generation of formaldehyde.SOLUTION: A composition for paper coating contains (1) a pigment, (2) a binder and (3) a resin for paper coating containing 0.3 to 1.8 mmol/g (solid) of an epihalohydrin-derived azetidinium group obtained by a reaction of (a) polyalkylene polyamine, (b) dibasic carboxylic acid-based compound, (c) ureas and (d) epihalohydrin and having a weight average molecular weight of 20,000 or less and a molecular weight distribution (Mw/Mn) of 2.5 or less, and the amount of calcium carbonate in the pigment is 90 to 100 mass%.

Description

  The present invention relates to a resin for paper coating and a composition for paper coating, and more specifically, by applying a paper coating composition containing the resin for paper coating of the present invention to a coated base paper, TECHNICAL FIELD The present invention relates to a paper coating resin that can impart excellent printability improvement effect to coated paper in a pigment composition containing a large amount of calcium carbonate, and does not generate formalin, and a paper coating composition using the same.

  Coated paper widely used as printing paper is conventionally produced by coating a base paper with a composition containing pigments such as clay and calcium carbonate and binders such as latex and starch as main components. In recent years, due to the trend of cost reduction, there has been a tendency to reduce the amount of expensive clay and greatly increase the amount of inexpensive calcium carbonate for pigment blending, and such coated paper is generally difficult to print. With the remarkable progress of printing technology represented by high speed, precision, and multicolor, it has become difficult to satisfy the demand for higher printability. In particular, in offset printing, there is a strong demand for ink acceptability that indicates the state of ink deposition during printing, improved water resistance against dampening water, and improved air permeability (improved blister resistance in rotary printing). It is becoming difficult to meet the requirements. In addition, since the blending of calcium carbonate is greatly increased, the tendency of the paper coating resin to affect the printability of conventional coated paper is different.

  Conventionally, as a resin intended to be added to a paper coating composition to give the above properties to coated paper, conventionally, for example, polyalkylene polyamine-urea-aldehyde resin, polyamide-urea-aldehyde resin, etc. Various resins have been developed.

However, the above paper coating resin is a resin modified with formaldehyde. When such a resin is used, formaldehyde, a regulated substance of hazardous air pollutants established by the Japan Paper Association, is applied. There was a problem of being generated from the resin being worked on or the coated paper obtained. In addition, the paper coating composition containing these paper coating resins, for example, promotes penetration of dampening water into the coating layer to improve ink acceptability, and has water resistance. Insufficient picking was likely to occur, and the paper coating composition was greatly thickened. Conventionally, in the resins that have been studied and proposed, formaldehyde has been indispensable for improving the ink acceptability and wet pick of coated paper. Therefore, a resin that does not use formaldehyde has good ink acceptability, wet pick, and air permeability. Development of a resin that can be improved is desired.

From such a viewpoint, the polyamide amine resin for paper coating that does not cause a significant increase in viscosity of the coating composition, improves the ink acceptability and wet pick of the coated paper in a well-balanced manner, and does not generate harmful substances. Has been proposed (see, for example, Patent Document 1).

  However, these polyamidoamine resins have a problem that, in a pigment formulation containing a large amount of calcium carbonate, the ink acceptance of coated paper, the water resistance against dampening water, and the air permeability are insufficient.

WO01 / 073200

  The present invention relates to a formaldehyde that can improve ink acceptability, wet pick, and air permeability of coated paper using a paper coating composition in which the calcium carbonate in the pigment is 90% by weight to 100% by weight. It is an object of the present invention to provide a paper coating composition and a paper coating resin that do not generate.

  In the composition for paper coating in which the calcium carbonate in the pigment is 90% by weight or more and 100% by weight or less, the present inventors provide a paper coating resin having a specific azetinium group amount, an average molecular weight, and a molecular weight distribution range. In this case, the inventors have found that the effect of improving the ink acceptability, wet pick, and air permeability of the coated paper is exhibited, and the present invention has been completed.

Means for solving the above-mentioned problems are:
(I)
(1) pigment,
(2) binder,
And (3) (a) a polyalkylene polyamine, (b) a dibasic carboxylic acid compound, (c) ureas and (d) an epihalohydrin-derived azetinium group obtained by reacting 0.3 to 1. Containing a paper coating resin that is 8 mmol / g (solid), has a weight average molecular weight of 20,000 or less, and a molecular weight distribution (Mw / Mn) of 2.5 or less,
A composition for paper coating, wherein the calcium carbonate in the pigment is 90% by mass or more and 100% by mass or less,
(Ii) The paper coating resin is in the range of 0.05 to 5 parts by mass and the binder is in the range of 5 to 50 parts by mass when the pigment is 100 parts by mass as the solid content. The composition for paper coating according to the description,
(Iii) used for a paper coating composition containing a pigment and a binder, wherein the calcium carbonate in the pigment is 90% by mass or more and 100% by mass or less; (a) a polyalkylene polyamine and (b) a dibasic carboxylic acid An azetinium group derived from epihalohydrin obtained by reacting a system compound, (c) ureas and (d) epihalohydrin is 0.3 to 1.8 mmol / g (solid), and a weight average molecular weight is 20,000 or less, A resin for paper coating having a molecular weight distribution (Mw / Mn) of 2.5 or less,
It is.

  According to the present invention, the formaldehyde capable of improving the ink acceptability, wet pick, and air permeability of coated paper using a paper coating composition in which the calcium carbonate in the pigment is 90% by weight or more and 100% by weight or less. It is possible to provide a paper coating composition and a paper coating resin that do not generate.

The resin for paper coating of the present invention contains a pigment and a binder, and is used for a paper coating composition in which the calcium carbonate in the pigment is 90% by mass or more and 100% by mass or less, and (a) a polyalkylene polyamine and ( b) Epihalohydrin-derived azetinium group obtained by reacting a dibasic carboxylic acid compound, (c) ureas, and (d) epihalohydrin is 0.3 to 2.0 mmol / g (solid), and weight A paper coating resin having an average molecular weight of 20,000 or less and a molecular weight distribution (Mw / Mn) of 2.5 or less.

ただし、前記一般式１中、Ｒ^６、Ｒ^７、Ｒ^８、Ｒ^９及びＲ^１０は、それぞれ水素原子、アルキル基、アリル基、アリール基を示し、両末端のアミノ基及び分子鎖中に結合するアミノ基の少なくとも２個のアミノ基はアミド結合可能な水素原子を結合する。このような条件を満たす限り、Ｒ^６、Ｒ^７、Ｒ^８、Ｒ^９及びＲ^１０それぞれは同一であっても相違する基であっても良い。式中のｑは、１〜１０、好ましくは２〜８、更に好ましくは２〜５であり、ｒは１〜１０、好ましくは１〜８、更に好ましくは１〜５であり、ｓは１〜１０、好ましくは２〜８、更に好ましくは２〜５である。 The (a) polyalkylene polyamine used in the present invention has a plurality of amino groups, and at least two of the amino groups are primary or secondary amino groups, and one or more alkylene groups. Say what you have. As a specific example of the polyalkylene polyamine, for example, a compound represented by the general formula 1 can be given.

However, in the said General formula 1, R < ⁶ >, R < ⁷ >, R <^8> , R < ⁹ > and R < ¹⁰ > show a hydrogen atom, an alkyl group, an allyl group, and an aryl group, respectively, and are couple | bonded in the amino group and molecular chain of both ends. At least two amino groups of the amino group to be bonded bind to hydrogen atoms capable of amide bonding. As long as these conditions are satisfied, R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ may be the same or different groups. Q in the formula is 1 to 10, preferably 2 to 8, more preferably 2 to 5, r is 1 to 10, preferably 1 to 8, more preferably 1 to 5, and s is 1 to 1. 10, preferably 2 to 8, more preferably 2 to 5.

When any of R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ^{10 in} the general formula 1 is an alkyl group, the alkyl group has 1 to 15 carbon atoms, particularly 1 to 10 carbon atoms. preferable. When any of R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ^{10 in} the general formula 1 is an aryl group, the aryl group may be a group having a condensed aromatic ring such as a naphthyl group, A group having a monocyclic aromatic ring such as

A preferred polyalkylene polyamine is a compound having at least two primary amino groups and at least one secondary amino group in the molecule. Examples of such compounds include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, iminobispropylamine, aminoethylpiperazine, 3-azahexane-1,6-diamine, 4,7-diazadecane-1,10-diamine, and the like. Can be mentioned. Among these compounds, polyethylene polyamine is preferable, and specifically, diethylenetriamine and triethylenetetramine, tetraethylenepentamine and aminoethylpiperazine are advantageous from an industrial viewpoint. These polyalkylene polyamines may be used alone or in combination of two or more. In addition, a part of the polyalkylene polyamine can be used in place of other amines such as alkylene diamine and carbocyclic amino compound as long as the effects of the present invention are not impaired.

  The (b) dibasic carboxylic acid-based compound in the present invention may be a dibasic carboxylic acid that can react with a polyalkylene polyamine to form a polyamide bond and a derivative thereof. Acid, 2,3-naphthalenedicarboxylic acid, succinic acid, glutaric acid, adipic acid, maleic acid, dibasic carboxylic acid such as cyclohexane-1,3- or -1,4-dicarboxylic acid, acid anhydrides thereof And / or these alkyl esters can be used, and a part of these may be used instead of a monocarboxylic acid compound as long as the effects of the present invention are not impaired. Also, carbocyclic dibasic carboxylic acids such as tetrahydrophthalic acid, 3- or 4-methyltetrahydrophthalic acid, hexahydrophthalic acid, 3- or 4-methylhexahydrophthalic acid, and endomethylenetetrahydrophthalic acid, these An acid anhydride can also be used. These dibasic carboxylic acid compounds may be used alone or in combination of two or more.

  Examples of the urea as component (c) in the present invention include urea, thiourea, guanylurea, methylurea, dimethylurea and the like, and urea is particularly preferable.

  Examples of the epihalohydrin as the component (d) in the present invention include epichlorohydrin, epibromohydrin and the like, and epichlorohydrin is preferable.

In the production of the resin for paper coating of the present invention, there is no particular problem in the order of reacting the components (a) to (c), and the reaction can be performed in any order.

For example, the condensation reaction can be performed by adding the component (a) and the component (b), and then the component (c) can be added to perform the deammonification reaction. The component (a) and the component (c) can be added to remove the ammonia. The reaction can be carried out, and then the component (b) can be added to carry out the condensation reaction. In this case, the condensation reaction is preferably performed at 60 to 300 ° C., preferably 80 to 200 ° C. for 1 to 10 hours, and the deammonification reaction is preferably performed at 90 to 180 ° C. for 1 to 10 hours.

Further, the condensation reaction and the deammonification reaction can be performed simultaneously by adding the component (a), the component (b) and the component (c). In this case, the reaction temperature is preferably 90 to 180 ° C. and 1 to 10 hours.

  The ratio of the components (a) to (c) of the resin for paper coating obtained by reacting the components (a) to (c) is the total amount of primary amino groups and secondary amino groups of (a) 1 The number of moles of component (b) is preferably in the range of 0.01 to 0.7 mole, and more preferably in the range of 0.01 to 0.4 mole, relative to mole. The number of moles of component (c) is preferably in the range of 0.1 to 1.0 mole, particularly preferably in the range of 0.2 to 0.6 mole.

  The amount of component (d) used is such that the number of moles of component (d) per mole of amino group in the reaction product obtained by reacting components (a) to (c) is in the range of 0.4 to 1.2 moles. Is preferred. Usually, the component (d) is added dropwise to the reaction product obtained by reacting the components (a) to (c) and heated to 30 to 100 ° C. to carry out the addition reaction or the crosslinking reaction for about 0.5 to 5 hours. Is preferred.

The azetinium group of the reaction product of the reaction product obtained by reacting the components (a) to (c) and the epihalohydrin (d) component is 0.3 to 1.8 mmol / g (solid). Preferably, it is 0.5 to 1.2 mmol / g (solid), and if it exceeds 1.8 mmol / g (solid), the viscosity of the paper coating composition is increased, and the wet pick is greatly reduced. There is a case. On the other hand, if it is less than 0.3 mmol / g (solid), the ink acceptability and wet pick of the coated paper cannot be improved.

The content of the azetinium group derived from epihalohydrin in the present invention is a value measured under the following conditions by ¹ H-NMR (internal standard substance TSP).
<Azetinium base amount of resin for paper coating>
¹ H-NMR analysis apparatus: INOVA-400, 5 mm 4n_PFG probe (manufactured by Varian)
(1) Preparation of measurement sample Accurately weigh 0.1 g of the sample solution and use TSP (3- (trimethylsilyl) 2,2,3,3, -d4) sodium propionate) (made by Isotech) as an internal standard substance. Was accurately weighed in an amount of 1.0 g of an aqueous solution diluted to 0.2% with heavy water (Across). A solution in which these were uniformly mixed was used as a measurement sample.
(2) Analytical method of azetinium group amount Measurement was carried out at room temperature with ¹ H of measurement nucleus and 32 times of integration. A peak of hydrogen bonded to carbon adjacent to nitrogen of the azetinium group is observed at a chemical shift of 4.3 ppm (2H) and 4.7 ppm (2H). From the integrated value of these sums and the integrated value of TSP, the amount of mmol of azetinium groups present in 1 g of resin was determined.

  The weight average molecular weight of the resin for paper coating in the present invention is 20,000 or less, and preferably the weight average molecular weight is 5 to 10,000. When the weight average molecular weight is larger than 20,000, the paper coating composition is increased in viscosity, and the wet pick may be significantly reduced. On the other hand, if it is less than 500, the effect of improving the ink acceptability and wet pick of the coated paper is low.

  The molecular weight distribution (Mw / Mn) of the paper coating resin in the present invention is 2.5 or less, preferably 2.0 or less.

The weight average molecular weight and molecular weight distribution of the paper coating resin in the present invention are values measured under the following conditions using GPC-MALS.
<Weight average molecular weight and molecular weight distribution of paper coating resin>
It measured on condition of the following using GPC-MALS.
(1) GPC-MALS
HPLC: 1100 Series (manufactured by Agilent)
Column oven: CO631A (manufactured by GLscience)
Column: G3000PWXL + G5000PWXL
RI detector: RI-101 (manufactured by Shodex)
Light scattering detector: DAWN-EOS (manufactured by Wyatt)
(2) Measurement conditions Solvent: 0.4 M phosphate buffer Flow rate: 1.0 mL / min
Temperature: 40 ° C

The paper coating composition of the present invention is a composition containing a pigment, a binder and the like in addition to the above-mentioned paper coating resin.

  The calcium carbonate in the pigment of the present invention must contain 90% by mass or more and 100% by mass or less of the calcium carbonate in the pigment, more preferably 95% by mass or more and 100% by mass or less. Fine calcium carbonate and light calcium carbonate can be used. Calcium carbonates of any particle size (fine or ultra fine), particle size (engineered, etc.), crystalline (calcite, aragonite, etc.) and coarse (cubic, spindle, rod, etc.) can be used. One kind of calcium carbonate may be used, or two or more kinds may be mixed and used.

  Examples of pigments other than calcium carbonate include inorganic pigments such as clay, talc, satin white, titanium dioxide, aluminum hydroxide, barium sulfate, calcium sulfite, synthetic silica, and zinc oxide, and styrene polymers and urea polymers. Organic pigments can be used. These pigments may be used alone or in combination of two or more, but need to be 10% by mass or less of the pigment.

  As the binder, an aqueous binder is preferable. Examples of the aqueous binder include styrene-butadiene resin, (meth) acrylate-butadiene resin, (meth) acrylate resin, polyvinyl alcohol resin, vinyl acetate resin, acrylamide resin, and styrene- (meth) acrylate resin. Resin, styrene-maleic acid resin, ethylene-vinyl acetate resin, and synthetic polymer compounds such as water-soluble synthetic polymer compounds such as polyvinyl alcohol and polyacrylamide, starch, modified starch (oxidized starch, esterified starch, Natural starch such as etherified starch, enzyme-modified starch, pregelatinized starch, and cationized starch), sodium alginate, guar gum, casein, gelatin, soybean protein, yeast protein, cellulose derivatives (carboxymethylcellulose, hydroxyethylcellulose, etc.) Compounds and derivatives thereof. Among these, it is preferable to use styrene-butadiene resin or modified starch.

  In the composition for paper coating of the present invention, in addition to the pigment, binder, dispersant, lubricant, thickener, thickener, antifoaming agent, antifoaming agent, antiseptic, antifungal agent, water retention agent, Various auxiliary agents such as a fluorescent brightener, a dye, a conductive agent, and a pH adjuster can be appropriately blended as necessary.

  In the paper coating composition of the present invention, the ratio of the paper coating resin, pigment, binder, and auxiliary agent is 0.05 to 5 parts by weight of the paper coating resin with respect to 100 parts by weight of the pigment. The binder is 5 to 50 parts by weight, preferably 10 to 30 parts by weight, and the auxiliary is 0.001 to 2 parts by weight, preferably 0.01 to 1 part by weight. Part. The ratios of paper coating resin, pigment, binder, and auxiliary are all calculated as solids.

  The paper coating composition of the present invention comprises, for example, a pigment dispersed in water together with a dispersant, added with a binder and, if necessary, an auxiliary such as a viscosity modifier, and further, the paper coating of the present invention. The resin is added and stirred, and if necessary, the pH is adjusted with a pH adjusting agent such as caustic soda or aqueous ammonia.

  The B-type viscosity at a solid content concentration of 64% of the resin composition for paper coating obtained in this way is partially agglomerated at 5000 mPa · s or more, causing streaks, scratches and bleeding, Not practical because of poor handling during coating. Preferably it is 3000 mPa * s or less. More preferably, it is 2000 mPa * s or less.

  The coated paper of the present invention can be produced by coating the paper coating composition of the present invention on the surface of the base paper by a known method and drying.

As the base paper, various high-quality papers such as neutral papermaking using calcium carbonate as a filler and acidic papermaking using talc as a filler, various kinds of paper made neutral or acidic Paper synthetic paper sheets and other sheet synthetic papers containing inorganic fibers are preferably used. The basis weight of the base paper is effective even less than 60 g / ^{m 2,} when using the base paper of 60~200g / ^{m 2,} blister resistance improving effect is remarkable, the base paper 80 to 200 g / ^{m 2} When used, the effect of improving blister resistance is further remarkable.

With respect to the coating amount of the paper coating composition, good performance can be obtained even if the total coating amount applied to both sides of the base paper is less than 20 g / m ^2, but it is resistant to ^{20 to} 50 g / m ^2. It is excellent in the blister property improving effect, and in the case of 30 to 50 g / m ² , it is further excellent in the blister resistance improving effect.

The paper 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, Champlex coaters, etc. It is coated on the surface of the base paper using a coating apparatus. Moreover, any coating method of on-machine coating and off-machine coating can be applied. The paper coating composition of the present invention can be applied to single-layer coating or multilayer coating, and can be applied to both single-side coating and double-side coating.

  Drying after coating can be performed by a usual method such as a gas heater, an electric heater, a steam heater, an infrared heater, or a hot air heater. After drying, the glossiness can be imparted by a finishing process such as a super calendar, a water calendar, or a gloss calendar, if necessary, and any other general processing means can be used.

  Hereinafter, although an example and a comparative example of the present invention are given and explained concretely, the present invention is not limited to these examples. In each example, “%” is “% by mass” unless otherwise specified.

(Production Example 1)
Diethylenetriamine (1.0 mol, 178.6 g) was charged into a four-necked flask equipped with a thermometer, a Liebig condenser, and a stirring rod, and the temperature was raised to 120 ° C. Adipic acid (0.5 mol, 126.5 g) was added, and a condensation reaction was carried out at 170 ° C. for 3 hours while removing generated water. Subsequently, the Liebig condenser was replaced with a reflux condenser, urea (1.1 mol, 114.4 g) and 18.7 g of water were added, and a deammonia reaction was performed at 120 ° C. for 3 hours. Next, 424.7 g of water was added, and epichlorohydrin (0.9 mol, 144.2 g) was added dropwise while paying attention to heat generation, and the mixture was further reacted at 60 ° C. for 1 hour. Water and 25% by mass ammonia water were added thereto to adjust the concentration and pH to obtain an aqueous solution of a paper coating resin having a solid content concentration of 50% by mass, pH 8.0, and B-type viscosity of 20 mPa · s. This is designated as a resin A for paper coating.

(Production Example 2)
Diethylenetriamine (1.0 mol, 170.1 g) was charged into a four-necked flask equipped with a thermometer, a Liebig condenser, and a stirring rod, and the temperature was raised to 120 ° C. Tetrahydrophthalic anhydride (0.5 mol, 125.4 g) was added, and a condensation reaction was performed at 170 ° C. for 3 hours while removing generated water. Subsequently, the Liebig condenser was replaced with a reflux condenser, urea (1.05 mol, 103.9 g) and 18.7 g of water were added, and a deammonia reaction was performed at 120 ° C. for 3 hours. Subsequently, 424.7 g of water was added, and epichlorohydrin (0.95 mol, 144.9 g) was added dropwise while paying attention to heat generation, and the mixture was further reacted at 60 ° C. for 1 hour. Water and 25% by mass ammonia water were added thereto to adjust the concentration and pH to obtain an aqueous solution of a paper coating resin having a solid content concentration of 50% by mass, pH 8.0, and B-type viscosity of 14 mPa · s. This is designated as a paper coating resin B.

(Production Example 3)
Triethylenetetramine (1.0 mol, 183.6 g) was charged into a four-necked flask equipped with a thermometer, a Liebig condenser, and a stirring rod, and the temperature was raised to 120 ° C. Terephthalic acid (0.5 mol, 104.3 g) was added, and a condensation reaction was carried out at 170 ° C. for 4 hours while removing generated water. Subsequently, the Liebig condenser was replaced with a reflux condenser, urea (1.55 mol, 116.9 g) and 18.4 g of water were added, and a deammonia reaction was performed at 120 ° C. for 3 hours. Next, 425.0 g of water was added, and epichlorohydrin (1.30 mol, 151.0 g) was added dropwise while paying attention to heat generation, and further reacted at 60 ° C. for 1 hour. Water and 25% by mass ammonia water were added thereto to adjust the concentration and pH to obtain an aqueous solution of a paper coating resin having a solids concentration of 50% by mass, pH 8.0, and B-type viscosity of 23 mPa · s. This is designated as a paper coating resin C.

(Production Example 4)
Tetraethylenepentamine (1.0 mol, 199.6 g) was charged into a four-necked flask equipped with a thermometer, a Liebig cooler, and a stirring rod, and the temperature was raised to 120 ° C. Adipic acid (0.5 mol, 77.1 g) was added, and a condensation reaction was carried out at 170 ° C. for 3 hours while removing generated water. Subsequently, the Liebig condenser was replaced with a reflux condenser, urea (1.9 mol, 120.3 g) and 18.1 g of water were added, and a deammonia reaction was performed at 120 ° C. for 3 hours. Next, 425.3 g of water was added, and epichlorohydrin (1.6 mol, 156.1 g) was added dropwise while paying attention to heat generation, and further reacted at 60 ° C. for 1 hour. Water and 25% by mass ammonia water were added thereto to adjust the concentration and pH to obtain an aqueous solution of a paper coating resin having a solid content concentration of 50% by mass, pH 8.0 and B-type viscosity of 26 mPa · s. This is designated as a resin D for paper coating.

(Production Example 5)
Diethylenetriamine (1.0 mol, 191.7 g) was charged into a four-necked flask equipped with a thermometer, a Liebig condenser, and a stirring rod, and the temperature was raised to 120 ° C. Adipic acid (0.5 mol, 135.8 g) was added, and a condensation reaction was carried out at 170 ° C. for 3 hours while removing generated water. Subsequently, the Liebig condenser was replaced with a reflux condenser, urea (1.5 mol, 167.4 g) and 21.8 g of water were added, and a deammonia reaction was performed at 120 ° C. for 3 hours. Next, 421.6 g of water was added, and epichlorohydrin (0.5 mol, 86.0 g) was added dropwise while paying attention to heat generation, and further reacted at 60 ° C. for 1 hour. Water and 25% by mass ammonia water were added thereto to adjust the concentration and pH to obtain an aqueous solution of a paper coating resin having a solid content concentration of 50% by mass, pH 8.0, and B-type viscosity of 15 mPa · s. This is designated as a resin E for paper coating.

(Production Example 6)
Triethylenetetramine (1.0 mol, 176.4 g) was charged into a four-necked flask equipped with a thermometer, a Liebig condenser, and a stirring rod, and the temperature was raised to 120 ° C. Adipic acid (0.5 mol, 88.1 g) was added, and a condensation reaction was carried out at 170 ° C. for 3 hours while removing generated water. Subsequently, the Liebig condenser was replaced with a reflux condenser, urea (1.3 mol, 94.2 g) and 16.3 g of water were added, and a deammonia reaction was performed at 120 ° C. for 3 hours. Subsequently, 427.0 g of water was added, and epichlorohydrin (1.7 mol, 189.7 g) was added dropwise while paying attention to heat generation, and further reacted at 60 ° C. for 1 hour. Water and 25% by mass ammonia water were added thereto to adjust the concentration and pH to obtain an aqueous solution of a paper coating resin having a solid content concentration of 50% by mass, pH 8.0 and B-type viscosity of 26 mPa · s. This is designated as a resin F for paper coating.

(Production Example 7)
Diethylenetriamine (1.0 mol, 201.9 g) was charged into a four-necked flask equipped with a thermometer, a Liebig condenser, and a stirring rod, and the temperature was raised to 120 ° C. Adipic acid (0.5 mol, 143.0 g) was added, and a condensation reaction was carried out at 170 ° C. for 3 hours while removing generated water. Subsequently, the Liebig condenser was replaced with a reflux condenser, urea (1.1 mol, 129.3 g) and 21.2 g of water were added, and deammonia reaction was performed at 120 ° C. for 3 hours. Next, 422.2 g of water was added, and epichlorohydrin (0.54 mol, 97.8 g) was added dropwise while paying attention to heat generation, and the mixture was further reacted at 60 ° C. for 1 hour. Water and 25% by mass ammonia water were added thereto to adjust the concentration and pH to obtain an aqueous solution of a paper coating resin having a solid content concentration of 50% by mass, pH 8.0, and B-type viscosity of 30 mPa · s. This is designated as a paper coating resin G.

(Production Example 8)
Diethylenetriamine (1.0 mol, 221.1 g) was charged into a four-necked flask equipped with a thermometer, a Liebig condenser, and a stirring rod, and the temperature was raised to 120 ° C. Adipic acid (0.5 mol, 156.6 g) was added, and a condensation reaction was carried out at 170 ° C. for 3 hours while removing generated water. Subsequently, the Liebig condenser was replaced with a reflux condenser, urea (1.1 mol, 141.6 g) and 23.2 g of water were added, and a deammonia reaction was performed at 120 ° C. for 3 hours. Subsequently, 420.2 g of water was added, and epichlorohydrin (0.3 mol, 59.5 g) was added dropwise while paying attention to heat generation, and further reacted at 60 ° C. for 1 hour. Water and 25% by mass ammonia water were added thereto to adjust the concentration and pH, thereby obtaining an aqueous solution of a paper coating resin having a solid content concentration of 50% by mass, pH 8.0, and B-type viscosity of 28 mPa · s. This is designated as a paper coating resin H.

(Production Example 9)
Diethylenetriamine (1.0 mol, 164.4 g) was charged into a four-necked flask equipped with a thermometer, a Liebig condenser, and a stirring rod, and the temperature was raised to 120 ° C. Adipic acid (0.5 mol, 116.4 g) was added, and a condensation reaction was carried out at 170 ° C. for 3 hours while removing generated water. Subsequently, the Liebig condenser was replaced with a reflux condenser, urea (1.1 mol, 105.3 g) and 17.2 g of water were added, and a deammonia reaction was performed at 120 ° C. for 3 hours. Next, 426.2 g of water was added, and epichlorohydrin (1.17 mol, 172.5 g) was added dropwise while paying attention to heat generation, and the mixture was further reacted at 40 ° C. for 1 hour. Water and 25% by mass ammonia water were added thereto to adjust the concentration and pH to obtain an aqueous solution of a paper coating resin having a solid content concentration of 50% by mass, pH 8.0, and B-type viscosity of 15 mPa · s. This is designated as paper coating resin I.

(Production Example 10)
Diethylenetriamine (1.0 mol, 172.8 g) was charged into a four-necked flask equipped with a thermometer, a Liebig condenser, and a stirring rod, and the temperature was raised to 120 ° C. Adipic acid (0.8 mol, 195.8 g) was added, and a condensation reaction was carried out at 170 ° C. for 3 hours while removing generated water. Subsequently, the Liebig condenser was replaced with a reflux condenser, urea (0.45 mol, 45.3 g) and 18.6 g of water were added, and a deammonia reaction was performed at 120 ° C. for 3 hours. Next, 424.8 g of water was added, and epichlorohydrin (0.95 mol, 147.2 g) was added dropwise while paying attention to heat generation, and further reacted at 80 ° C. for 1 hour. Water and 25% by mass ammonia water were added thereto to adjust the concentration and pH to obtain an aqueous solution of a paper coating resin having a solid content concentration of 50% by mass, pH 8.0, and B-type viscosity of 59 mPa · s. This is designated as resin J for paper coating.

(Production Example 11)
With reference to Example 2 of WO01 / 073200 (Patent Document 1), an aqueous solution of a paper coating resin having a solid content of 60% by mass, a pH of 7.5, and a B-type viscosity of 600 mPa · s was obtained. This is designated as a resin K for paper coating.

  The viscosity, pH, azetinium group amount, molecular weight, and quantity distribution of the paper coating resins obtained in Production Examples 1 to 10 were measured as follows. The measurement results are shown in Table 1.

<Viscosity of paper coating resin>
Using a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd .: model BM type), the viscosity of the paper coating resin was measured at 25 ° C. and 60 rpm.

<PH of resin for paper coating>
The pH of the paper coating resin was measured using a glass electrode type hydrogen ion concentration meter (manufactured by Tokyo Denki Kogyo Co., Ltd.).

<Azetinium base amount of resin for paper coating>
[1]> ¹ H-NMR analysis apparatus: INOVA-400, 5 mm 4n_PFG probe (manufactured by Varian)
(1) Preparation of measurement sample Accurately weigh 0.1 g of the sample solution and use TSP (3- (trimethylsilyl) 2,2,3,3, -d4) sodium propionate) (made by Isotech) as an internal standard substance. Was accurately weighed in an amount of 1.0 g of an aqueous solution diluted to 0.2% with heavy water (Across). A solution in which these were uniformly mixed was used as a measurement sample.
(2) Analytical method of azetinium group amount Measurement was carried out at room temperature with ¹ H of measurement nucleus and 32 times of integration. A peak of hydrogen bonded to carbon adjacent to nitrogen of the azetinium group is observed at a chemical shift of 4.3 ppm (2H) and 4.7 ppm (2H). From the integrated value of these sums and the integrated value of TSP, the amount of mmol of azetinium groups present in 1 g of resin was determined.

<Weight average molecular weight and molecular weight distribution of paper coating resin>
It measured on condition of the following using GPC-MALS.
(1) GPC-MALS
HPLC: 1100 Series (manufactured by Agilent)
Column oven: CO631A (manufactured by GLscience)
Column: G3000PWXL + G5000PWXL
RI detector: RI-101 (manufactured by Shodex)
Light scattering detector: DAWN-EOS (manufactured by Wyatt)
(2) Measurement conditions Solvent: 0.4 M phosphate buffer Flow rate: 1.0 mL / min
Temperature: 40 ° C

Next, the example which adjusted and evaluated the composition for paper coating using each resin obtained by the above manufacture example is shown. In the following example, the following master color I was used.

Master color I composition:
<Pigment>
Calcium carbonate: FMT-97 (manufactured by Pimatech) 100 parts by mass <Binder>
Latex: JSR-0696 (manufactured by JSR Corporation) 10 parts by mass Starch: MS-4600 (manufactured by Nippon Shokuhin Kako Co., Ltd.) 2 parts by mass <Others>
Defoamer: SN-Deformer 777 (San Nopco Co., Ltd.) 0.05 parts by mass

  Examples 1 to 7: To the master color I, the paper coating resins A to G obtained in Production Examples 1 to 7 with respect to 100 parts by mass of the pigment in the master color I have a solid content of 0.5 mass. It added so that it might become the ratio of a part. A composition for paper coating by adjusting the solids concentration and pH with water and a 30% by weight aqueous sodium hydroxide solution so that each composition has a total solids concentration of 64% by mass and a pH of 9.5. I got a thing.

  Comparative Examples 1 to 4: To Master Color I, 100 parts by mass of the pigment therein, the paper coating resins HK obtained in Production Examples 8 to 11, and the solid content therein being 0.5 mass It added so that it might become the ratio of a part. A composition for paper coating by adjusting the solids concentration and pH with water and a 30% by weight aqueous sodium hydroxide solution so that each composition has a total solids concentration of 64% by mass and a pH of 9.5. I got a thing.

Next, the example which adjusted and evaluated the composition for paper coating using each resin obtained by the above manufacture example is shown. In the following example, the following master color II was used.

Master color II composition:
<Pigment>
Clay: Ultra white 90 (manufactured by BASF) 15 parts by mass Calcium carbonate: FMT-97 (manufactured by Pimatech) 85 parts by mass <Binder>
Latex: JSR-0696 (manufactured by JSR Corporation) 10 parts by mass Starch: MS-4600 (manufactured by Nippon Shokuhin Kako Co., Ltd.) 2 parts by mass <Others>
Dispersant: Aron T-50 (manufactured by Toa Gosei Co., Ltd.) 0.02 parts by mass Defoamer: SN-Deformer 777 (manufactured by San Nopco Co., Ltd.) 0.05 parts by mass

  Comparative Examples 5 to 8: To Master Color II, with respect to 100 parts by mass of the pigment therein, the paper coating resins A to B and H to I obtained in Production Examples 1 to 2 and 8 to 9 Was added so that the solid content was 0.5 parts by mass. A composition for paper coating by adjusting the solids concentration and pH with water and a 30% by weight aqueous sodium hydroxide solution so that each composition has a total solids concentration of 64% by mass and a pH of 9.5. I got a thing.

Physical property test of paper coating composition and evaluation of coated paper The B-type viscosity and high shear viscosity of this paper coating composition were measured. Further, this paper coating composition was applied to one side of a high-quality paper having a basis weight of 79 g / m ² using a blade coating machine so that the coating amount was 10 g / m ^2. Hot air drying was performed at 5 ° C. for 5 seconds. Next, humidity was adjusted for 24 hours at a temperature of 23 ° C. and a relative humidity of 50%, and further, calendar treatment was performed twice under the conditions of a roll temperature of 60 ° C. and a linear pressure of 125 kN / m to obtain a coated paper. The obtained coated paper was conditioned at a temperature of 23 ° C. and a relative humidity of 50% for 24 hours, and then ink acceptability, wet pick, and air permeability were evaluated. The results are shown in Table 2.

  Each test method is as follows.

(1) B-type viscosity of paper coating composition Using a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd .: Model BM type) at 25 ° C. and 60 rpm, the paper coating composition immediately after preparation The viscosity was measured.

(2) High Shear Viscosity of Paper Coating Composition Using a Hercules type high shear viscometer, measurement was performed at 25 ° C. with Bob F at a rotational speed of 6600 rpm and a sweep time of 5 seconds.

(3) Wet pick Using an RI printing tester (IHI Machine System Co., Ltd .: RI-1 type), the coated surface was wetted with a water supply roll and then printed, and the paper peeling state was visually observed and judged. Judgment is excellent 5.0-inferior 1.0, and it shows that there is so few paper peeling that a numerical value is large, and water resistance is favorable.

(4) Ink acceptability Using an RI printing tester (made by IHI Machine Systems Co., Ltd .: RI-1 type), the coated surface was wetted with a water absorption roll and printed, and the value indicated by the Macbeth densitometer was accepted. It was sex. The larger the value, the better the ink acceptability.

(5) Air permeability Measured using PPS (Parker Print Surf) manufactured by MESSMER. It shows that air permeability is so favorable that a numerical value is small.

  As is apparent from Table 2, it can be seen that the ink acceptability and wet pick of the coated paper are improved in a well-balanced manner by using the paper coating composition of the present invention.

By contrasting Examples 1-2 and Comparative Examples 5-6, when using calcium carbonate as a pigment of the coating composition in an amount of 90% by mass or more and 100% by mass or less, the composition for paper coating of the present invention is used. It can be seen that the use improves the ink acceptability, water resistance and air permeability of the coated paper in a well-balanced manner.

Moreover, by comparing Examples 1-2 and Comparative Examples 5-6 and Comparative Examples 1-2 and Comparative Examples 7-8, 90% by mass or more and 100% by mass of calcium carbonate as a pigment of the coating composition. When used below, by using the paper coating resin of the present invention, compared to the case where a paper coating resin other than the present invention is used in the paper coating composition, the ink acceptability and water resistance of the coated paper are as follows. It can also be seen that the air permeability is remarkably improved with good balance.

By comparing Example 1 with Comparative Examples 1 and 2, the paper coating composition of the paper coating resin of the present invention in which the azetinium group is 0.3 to 1.8 mmol / g (solid) is used. This indicates that the effect of improving the ink acceptability and water resistance of the coated paper is excellent.

By comparing Example 1 with Comparative Example 3, the paper coating composition and molecular weight distribution (Mw / Mn) when the weight average molecular weight of the paper coating resin of the present invention is greater than 20,000 are 2. When the composition for paper coating in the case of larger than 5 is used, it turns out that the ink receptivity and water resistance improvement effect of coated paper are inadequate.

By comparing Example 1 with Comparative Example 4, the paper coating composition using the paper coating resin of the present invention rather than the paper coating composition using the prior art paper coating resin. It can be seen that the ink acceptability, water resistance and air permeability of the coated paper can be improved in a well-balanced manner.

Claims (3)

(1) pigment,
(2) a binder, and (3) (a) a polyalkylene polyamine, (b) a dibasic carboxylic acid compound, (c) ureas, and (d) an epihalohydrin-derived azetinium group obtained by reaction. A resin for paper coating having a weight average molecular weight of 20,000 or less and a molecular weight distribution (Mw / Mn) of 2.5 or less, which is from 3 to 1.8 mmol / g (solid),
A paper coating composition, wherein the calcium carbonate in the pigment is 90% by mass or more and 100% by mass or less. 2. The paper according to claim 1, wherein when the solid content is 100 parts by mass of pigment, the paper coating resin is in the range of 0.05 to 5 parts by mass and the binder is in the range of 5 to 50 parts by mass. Composition for coating. Containing a pigment and a binder, and used in a paper coating composition in which the calcium carbonate in the pigment is 90% by mass or more and 100% by mass or less,
Epihalohydrin-derived azetinium group obtained by reacting (a) polyalkylene polyamine, (b) dibasic carboxylic acid compound, (c) urea and (d) epihalohydrin is 0.3 to 1.8 mmol / g. A resin for paper coating, which is (solid), has a weight average molecular weight of 20,000 or less, and a molecular weight distribution (Mw / Mn) of 2.5 or less.