JP3920652B2 - Surface sizing agent for papermaking, printing paper and method for producing printing paper - Google Patents

Description

＜ポリマー組成記号＞
ST ：スチレン
nBA ：アクリル酸ｎ−ブチル
MA ：メタクリル酸
AA ：アクリル酸
tBMA：メタクリル酸ｔ−ブチル
DIB ：ジイソブチレン
Manh：無水マレイン酸
EHA ：アクリル酸２−エチルヘキシル
iBMA：メタクリル酸イソブチル
【００４６】
＜脱墨古紙パルプ７０％配合ＰＰＣ用原紙への表面サイズ剤塗工試験＞
実施例１
合成例１の表面サイズ剤を酸化澱粉（ＭＳ−３８００：日本食品化工社製）の糊化溶液に溶解し、酸化澱粉５％、表面サイズ剤０．２％含有の塗工液を調製した。
未塗工脱墨古紙パルプ７０％配合ＰＰＣ用原紙（坪量６５ｇ／ｍ2、内添サイズ剤ＡＫＤ系、ステキヒトサイズ度１０秒）を用意し、ラボサイズプレスで塗工液温度５０℃で吸液量３０ｇ／ｍ²にて塗工し、９０℃回転式ドラムドライヤーに９０秒間通し乾燥して表面サイジング塗工紙を得た。
【００４７】
実施例２〜３
合成例２〜３の表面サイズ剤を用いた他は実施例１と同様にして実施例２〜３の塗工紙を得た。
参考例１〜２
合成例４〜５の表面サイズ剤を用いた他は実施例１と同様にして参考例１〜２の塗工紙を得た。
【００４８】
参考例３〜１１
合成例９〜１７の表面サイズ剤を用いた他は実施例１と同様にして参考例３〜１１の塗工紙を得た。
【００４９】
参考例１２
ラウリン酸のアンモニウム塩と合成例８の表面サイズ剤を酸化澱粉（ＭＳ−３８００：日本食品化工製）の糊化溶液に溶解し、酸化澱粉５％、ラウリル酸アンモニウム０．０４％、合成例８の表面サイズ剤０．１６％含有の塗工液を調製した。この塗工液を用い、かつ実施例１と同様のＰＰＣ用原紙を用いて、実施例１と同様にして表面サイズ塗工紙を得た。
【００５０】
比較例１
合成例８の表面サイズ剤を酸化澱粉（ＭＳ−３８００：日本食品化工製）の糊化溶液に溶解し、酸化澱粉５％、表面サイズ剤０．３％含有の塗工液を調製した。この塗工液を用い、かつ実施例１と同様のＰＰＣ用原紙を用いて、実施例１と同様にして比較例１の塗工紙を得た。
【００５１】
比較例２〜４
合成例６〜８の表面サイズ剤を用いた他は実施例１と同様にして比較例２〜４の塗工紙を得た。
【００５２】
参考例１３〜１５
合成例１８〜２０の表面サイズ剤を用いた他は実施例１と同様にして参考例１３〜１５の塗工紙を得た。
【００５３】
＜塗工紙の性能試験＞
(１)ステキヒトサイズ度：ＪＩＳ Ｐ ８１２２に基づき紙のステキヒトサイズ度（耐水度）を測定した。数値（秒）が高いほど、耐水度が高いことを示している。
(２) インクジェット適性：塗工紙についてキヤノン（株）社製のインクジェットプリンターBJ 10vlite（染料系黒インク）、および同BJ S600（顔料系黒インク）にて各パターンを印字し、以下の評価を行った。
（2-1）フェザリング：Ｊ．ＴＡＰＰＩ紙パルプ試験方法（Ｎｏ．１２）の「ペン書きサイズ度試験方法」に所載の「標準にじみ見本」に基づき、モノクロ印字での６段階評価（良（ヒゲなし）６〜１劣）を行った。
（2-2）裏抜け：モノクロベタ印字部を紙裏面から目視してインクの裏抜けを４段階評価（良◎−○−△−×不良）を行った。
（2-3）ブリーディング：上記インクジェットプリンターBJ S600にて黄および黒混合カラーパターン印字の境界滲み状態を目視にて４段階評価（良◎−○−△−×不良）を行った。
【００５４】
各実施例、比較例の塗工紙のステキヒトサイズ度とインクジェット印刷での塗工性能試験結果を表２に示す。
【表２】

表２の性能試験結果によれば、本発明にかかる塗工紙はインクジェット印字のフェザリングと裏抜けに対して効果的であることがわかる。
【００５５】
【発明の効果】
本発明のアニオン性製紙用表面サイズ剤、これを用いた印刷用紙および印刷用紙の製造方法によれば、脱墨古紙パルプ含有紙であっても、脱墨古紙パルプを含有しないインクジェット印刷用紙並のサイズ剤塗工量で、印字ヒゲ、フェザリングの発生を抑制でき、脱墨古紙パルプを含有しない印刷用紙と同等の印刷性能を得ることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface sizing agent for papermaking, a printing paper, and a method for producing a printing paper. More specifically, the present invention imparts a high degree of ink jet printing aptitude to not only printing paper such as ink jet printing paper but also deinked waste paper and pulp-containing paper. The present invention relates to a surface sizing agent that can be used, a printing paper obtained by using the surface sizing agent, and a method for producing the printing paper.
[0002]
[Prior art]
Conventionally, alkali neutralized salt aqueous solutions such as styrene-maleic acid copolymer, olefin-maleic acid copolymer, and styrene-acrylic acid copolymer have been frequently used as the paper surface size. However, in recent papers with neutral paper and with reduced or eliminated internal sizing agents, the coating amount of the surface sizing agent is often increased in order to obtain sizing properties. Recently, printing is often performed using an ink jet printer.
[0003]
On the other hand, deinked waste paper pulp is frequently used for inkjet printing paper due to environmental problems. As a result, so-called beard and feathering, a phenomenon in which ink of ink jet printing spreads along some fibers of the deinked waste paper pulp tends to occur. Such a phenomenon significantly reduces the print quality in ink jet printing. As countermeasures, there are measures such as improving the quality of recycled pulp, adding a large amount of internal sizing agent, and increasing the surface sizing agent, but these methods are disadvantageous in terms of production cost and operability. There are many.
[0004]
[Problems to be solved by the invention]
Conventionally, various surface sizing agents have been used for inkjet paper. For example, many cationic surface sizing agents are used for coated paper and inkjet paper, and various anionic surface sizing agents, particularly branched olefin-maleic acid copolymer salts and (meth) acrylic, are used for inkjet / PPC co-paper. An acid ester / (meth) acrylic acid copolymer salt aqueous solution or the like has been often used. These surface sizing agents give uniform and appropriate hydrophobicity to the paper surface in high-quality paper containing no deinked waste paper pulp, and are effective to some extent in preventing the feathering and improving the bleeding and bleeding properties.
[0005]
However, paper made from deinked waste paper pulp and mechanical pulp obtained from newspaper waste paper (hereinafter simply referred to as deinked waste paper pulp-containing paper) is a mixture of fibers that differ greatly in hydrophilicity, fiber length, and surface condition. Therefore, the surface sizing agent does not have the same hydrophilicity and affinity with water-based ink-jet inks, and it is difficult to suppress bleeding into fiber parts that have a particularly high affinity with ink-jet inks. .
[0006]
There is a method to increase the sizing degree more than necessary by using a large amount of surface sizing agent with extremely high hydrophobicity, such as an internally added size or alkyl ketene dimer (AKD) type surface sizing agent. Troubles such as cost and paper manufacturing stains are likely to occur, and the AKD sizing agent tends to cause paper slippage. In monochrome printing, printing can be performed even at high sizing, but in color printing, due to the slowness of ink setting that comes from high sizing, mixed color bleeding and bleeding caused by liquid mixing of different color inks on the paper surface are worse. Results in.
[0007]
In this way, even in the mixed state of deinked waste paper pulp from newspaper waste paper, which is a fiber with significantly different hydrophilicity, fiber length, and surface state, the fiber surface portion with extremely high ink affinity is equivalent to other fiber surfaces. There is a need for a surface sizing agent that exhibits an effect that is ink compatible.
[0008]
The present invention has been completed in view of such a situation, and even if it is deinked waste paper pulp-containing paper, printing whisker and feathering generated by inkjet printing or the like with a normal sizing agent coating amount. It is an object to provide an anionic papermaking surface sizing agent capable of suppressing the above, a printing paper using the same, and a method for producing the printing paper.
[0009]
[Means for Solving the Problems]
The present inventors include a normal hydrophobic group-containing polycarboxylic acid type anionic paper surface sizing agent containing fatty acids or a salt thereof for surface sizing, or a coating solution at the time of surface sizing containing fatty acids or By adding and mixing the salt and sizing the surface, printing debris, feathering, etc. that occur when printing on deinked wastepaper pulp-containing paper, especially inkjet printing paper containing deinked wastepaper pulp, with a normal surface sizing agent coating amount As a result, the present invention has been completed.
[0010]
  That is, the present invention has the following configuration.
(1)The polymerization reaction of the hydrophobic group-containing polycarboxylic acid type polymer was carried out in the presence of fatty acids or salts thereof to contain fatty acids or salts thereof.Hydrophobic group-containing polycarboxylic acid type anionic paper surface sizing agent characterized by the above.
(2) The surface sizing agent for papermaking according to the above (1), wherein the content of the fatty acids or a salt thereof is 3 to 25% by weight of the surface sizing agent solid content.
(3) The surface size for papermaking as described in (1) or (2) above, wherein the fatty acid is a saturated or unsaturated fatty acid having 6 to 18 carbon atoms or a saturated or unsaturated aliphatic hydroxy acid having 6 to 18 carbon atoms. Agent.
( 4 )Above (1) ~( 3 )A printing paper which is surface-sized using the paper size sizing agent according to any one of the above.
( 5 )Deinked waste paper Pal containing paper above (4) Printing paper as described.
(6) Deinked waste paper pulp containing inkjet printing paper above (5) Printing paper as described.
[0011]
Using a hydrophobic group-containing polycarboxylic acid type surface sizing agent containing fatty acids or salts thereof, or a coating liquid containing fatty acids or salts thereof, for recycled paper, especially deinked waste paper containing pulp The reason why printing whiskering and feathering can be suppressed by surface sizing is not clear, but fatty acids or their salts are distributed in the fiber portion of deinked waste paper pulp, which has a particularly high affinity with inkjet ink, and inkjet ink As a result, it is presumed that the affinity with the ink is alleviated and uniformized as a result, and the concentrated bleeding of the ink is suppressed.
In particular, it is considered that the fatty acid having a specific carbon number or a salt thereof is easily distributed in the fiber portion having high ink affinity.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail. The hydrophobic group-containing polycarboxylic acid type anionic paper surface sizing agent according to the present invention is mainly a polymer in which a hydrophobic group-containing polycarboxylic acid is water-soluble or water-dispersed by alkali neutralization (that is, in an alkali salt or alkali). The surface sizing agent containing the product), specifically, an aqueous solution or aqueous dispersion in which the above polymer is dissolved or dispersed.
[0013]
Examples of the fatty acids include saturated fatty acids having 6 to 18 carbon atoms such as caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid and stearic acid; and 6 carbon atoms such as oleic acid, linoleic acid and linolenic acid. Unsaturated fatty acids having ˜18; hydroxy fatty acids having 6 to 18 carbon atoms such as ricinoleic acid and hydroxystearic acid; mixed fatty acids such as coconut fatty acid, etc. Preferably, fatty acids are used. Examples of the fatty acid salts include ammonium salts of the above fatty acids; alkali metal salts such as sodium and potassium; organic amine salts such as alkanolamines and alkylamines.
[0014]
With fatty acids having less than 6 carbon atoms, even when used as a surface sizing agent, the effect of suppressing the occurrence of printing whisker and feathering on printing paper such as deinked waste paper and pulp-containing paper (hereinafter simply referred to as feathering suppression effect) ) May be low. On the other hand, if it exceeds 18 carbon atoms, it cannot be stably contained in the surface sizing agent, and the effect of suppressing feathering may be reduced. In particular, a saturated fatty acid having 8 to 12 carbon atoms or a fatty acid containing the same as a main component has high content stability with respect to the surface sizing agent, and also has a high feathering suppressing effect.
[0015]
The content of fatty acids or salts thereof is 3 to 25% by weight, preferably 5 to 20% by weight, based on the solid content of the surface sizing agent. If it is less than 3% by weight, the effect of suppressing feathering when used as a surface sizing agent is likely to be low. On the other hand, if it exceeds 25% by weight, the sizing effect is particularly low on neutral paper, and the surface sizing agent is starch. The foaming property of the coating liquid mixed with the above becomes high, which may cause problems in operability.
[0016]
The hydrophobic group-containing polycarboxylic acid in the present invention is a copolymer obtained by copolymerizing mainly a carboxylic acid group-containing monomer and a hydrophobic monomer. Examples of the carboxylic acid group-containing monomer include (meth) acrylic acid, maleic anhydride, maleic acid, itaconic acid, half esters of maleic acid and various lower alcohols, and salts thereof.
[0017]
Examples of the hydrophobic group-containing monomer include styrenes such as styrene, α-methylstyrene, and vinyltoluene; olefins such as diisobutylene, octene, decene, and dodecene; methyl (meth) acrylate, ethyl (meth) acrylate, (Meth) acrylic esters such as propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate ; Α, β dicarboxylic acid diesters such as dibutyl maleate and dibutyl fumarate;
[0018]
The addition amount of the carboxylic acid group-containing monomer is about 20 to 70% by weight, preferably about 30 to 60% by weight, based on the total amount of monomers.
Moreover, you may add the other monomer which can be copolymerized to said monomer. Examples of other copolymerizable monomers include sulfonic acid group-containing monomers such as styrene sulfonic acid, (meth) allyl sulfonic acid, and vinyl sulfonic acid, and salts thereof; hydroxyl group-containing monomers, (Meth) acrylamide, (meth) acrylamide derivatives, acrylonitrile, and radical copolymerization that does not hinder the performance of amino group-containing monomers and crosslinkable monomers, and other surface sizing agents, if present in small amounts Monomers can be used. Such other monomer is preferably 20% by weight or less based on the total amount of the carboxylic acid group-containing monomer and the hydrophobic monomer.
[0019]
These copolymers, which are hydrophobic group-containing polycarboxylic acids, can be used as a surface sizing agent after being neutralized and water-dispersed or water-dispersed with an alkali such as ammonia, caustic soda, caustic potash, or low molecular weight organic amines.
[0020]
  The polymerization reaction is performed by ordinary solution polymerization, emulsion polymerization, and bulk polymerization by combining the radical polymerizable monomers. Regardless of which polymerization method is used, the surface sizing agent of the present inventionIs heavyPolymerize in the presence of fatty acids or their salts at the same time. As shown in the reference examples described later,Surface sizing agent by mixing fatty acids or their salts after polymerizationOrFurther, the surface sizing may be carried out by directly mixing a fatty acid or a salt thereof with the surface sizing agent-containing coating solution.
[0021]
Examples of organic solvents in the case of solution polymerization include aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; esters such as butyl acetate; ketone solvents such as methyl ethyl ketone, diethyl ketone, and methyl isobutyl ketone; ethanol, isopropyl alcohol, Alcohols such as butanol and pentanol can be used according to the kind of the polymerization monomer.
[0022]
Examples of the polymerization initiator include oil-soluble lauroyl peroxide, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxyacetate, t-butyl peroxybenzoate, and the like. An organic peroxide or an azo initiator such as azobisisobutyronitrile can be used.
[0023]
  As the solution polymerization method, for example, fatty acids or salts thereof are allowed to coexist., LaVarious polymerization methods used in general solution polymerization, such as dissolving a dical polymerizable monomer in an organic solvent and adding a polymerization initiator under heating to perform polymerization, can be employed. After solution polymerization, the organic solvent is removed from the resulting polymer solution by distillation, and then neutralized and water-solubilized with an alkali such as ammonia, caustic soda, caustic potash or organic amine, or water is added to the polymer solution after polymerization and water-solubilized. And then remove the organic solvent by distillation. ThisThe anionic surface sizing agent is preferably 10 to 40% by weight of a water-soluble hydrophobic group-containing polycarboxylic acid, preferablyIs 2Contains 0-30% by weight. The surface sizing agent has a viscosity of 2000 cps (25 ° C.) or less, preferably 20 to 1000 cps (25 ° C.).
[0024]
  The method of emulsion polymerization is a general anionic or nonionic surfactant, a polymer surfactant or a water-soluble resin (for example, solution polymerization as shown in Synthesis Example 11, which will be described later, followed by saponification) Resin, etc.) in water, add radically polymerizable monomer, and after heating, add a polymerization initiator such as water-soluble persulfate or water-soluble azo compound, emulsion polymerize, add alkali and add water And emulsion polymerization in which water-soluble radical polymerization initiator is added dropwise to a pre-emulsified radical-polymerizable monomer, surfactant and water in warm water. There are methods. Both are used by dissolving fatty acids or their salts in monomersTheFurther, after polymerization, an alkali such as ammonia, caustic soda, caustic potash, or low molecular weight organic amine is added to the polymerization solution to neutralize water-soluble or water-dispersed, and this is dissolved or dispersed in water to obtain a hydrophobic group-containing polycarboxylic acid. An anionic surface sizing agent containing ˜40% by weight is obtained.
[0025]
  In bulk polymerization, fatty acids or their salts are added during bulk polymerization.To do.
The surface sizing agent of the present invention may be used alone or in combination with oxidized starch, sodium alginate, carboxymethyl cellulose, acrylamide polymer, polyvinyl alcohol and the like. The coating liquid containing the surface sizing agent of the present invention is preferably used at a surface sizing agent solid content of 0.2% by weight or more.
Further, the surface sizing agent of the present invention can be applied to various types of paper by known coating methods such as impregnation method, size press method, gate roll method, bar coater method, calendar method, spray method, and shim sizer method. Can be applied by any method. The coating amount of the surface sizing agent of the present invention may be the same as the coating amount on ordinary printing paper that does not contain deinked waste paper pulp or mechanical pulp. 01-2g / cm², Preferably about 0.05 to 0.5 g / cm²Is appropriate.
[0029]
The paper to which the surface sizing agent of the present invention is applied is not particularly limited, and can be applied to various printing papers that require surface sizing. Examples of such printing paper include newspaper paper, writing / drawing paper (notebooks, stationery paper, etc.), book paper, form paper, PPC paper, inkjet paper, thermal recording paper, pressure sensitive recording paper, coated paper (cast coated paper). Printing paper such as fine coated printing paper, art paper, etc., and can also be applied to packaging paper such as kraft paper and pure white roll paper.
In particular, since the surface sizing agent of the present invention is excellent in the effect of suppressing feathering, it is preferably applied to deinked waste paper pulp-containing paper, especially deinked waste paper pulp-containing inkjet printing paper.
[0030]
【Example】
Next, the present invention will be described in detail with reference to synthesis examples, examples and comparative examples. In addition, all% described below is weight%.
<Synthesis of Hydrophobic Group-Containing Polycarboxylic Acid Type Anionic Surface Sizing Agent>
[0031]
Synthesis example 1
In a reaction vessel of a 1 L four-necked flask equipped with a stirrer and a thermometer, 162 g of diisopropyl ketone, 1.6 g of N dodecyl mercaptan, 81.6 g of styrene, 32 g of methacrylic acid, 32 g of acrylic acid, 14.4 g of n-butyl acrylate and caprin 28.2 g of acid was charged and the temperature was raised to reflux temperature with stirring. Separately, 32 g of a 10% by weight diisopropyl ketone solution of lauroyl peroxide was dropped from the dropping funnel into the reaction vessel over 1.5 hours, and further aged at reflux temperature for 4 hours. After cooling, 85.9 g of 48% potassium hydroxide and 400 g of water were added dropwise to effect saponification and dissolution. Next, the mixture was heated to reflux temperature, and diisopropyl ketone was distilled off by azeotropic distillation with water. After cooling, 16 g of 25% aqueous ammonia was added and diluted with water to obtain an anionic surface sizing agent having a solid content of 20%.
[0032]
Synthesis example 2
550 g of water and 1.6 g of sodium dodecylbenzenesulfonate were charged into a reaction vessel of a 1 L four-necked flask equipped with a stirrer and a thermometer, and the temperature was raised to 90 ° C. One dropping funnel was charged with 80 g of methacrylic acid, 24 g of styrene, 56 g of t-butyl methacrylate, 1.6 g of N-dodecyl mercaptan and 40 g of lauric acid, and mixed and homogenized. 48 g of 5% aqueous solution of ammonium persulfate was prepared in another dropping funnel, both were dropped into the reaction vessel over 2 hours, and after completion of dropping, the mixture was aged for 1 hour and cooled. Next, 77 g of 25% aqueous ammonia was added to neutralize and dissolve in water to obtain an anionic surface sizing agent having a solid content of 20%.
[0033]
Synthesis example 3
A 1 L four-necked flask equipped with a stirrer and a thermometer was charged with 550 g of water and 1.6 g of sodium dodecylbenzenesulfonate and heated to 85 ° C. One dropping funnel was charged with 56 g of acrylic acid, 64 g of styrene, 40 g of N-butyl acrylate, 4.8 g of N-dodecyl mercaptan, and 17.8 g of coconut fatty acid, and mixed and homogenized. 48 g of 5% ammonium persulfate aqueous solution was prepared in another dropping funnel, and both were dropped into the flask over 4 hours. After completion of dropping, the mixture was aged for 1 hour and cooled, and neutralized and water-solubilized by adding 109 g of 20% potassium hydroxide and 32 g of 25% aqueous ammonia to obtain an anionic surface sizing agent having a solid content of 20%.
[0034]
Synthesis example 4
A reaction vessel of a 1 L four-necked flask equipped with a stirrer and a thermometer was charged with 82 g of toluene and 80 g of maleic anhydride, and the temperature was raised to the reflux temperature with stirring. Separately, 121.9 g of diisobutylene (2,4,4-trimethyl-1-pentene content 75%) in which 2 g of t-butyl peroxyacetate was dissolved was prepared in a dropping funnel and dropped into the reaction vessel over 2 hours. The mixture was further aged at reflux temperature for 4 hours. After cooling, 111 g of 25% aqueous ammonia and 400 g of water were added dropwise to effect saponification and dissolution. Next, the mixture was heated to reflux temperature, and toluene and unreacted diisobutylene were distilled off by azeotropic distillation with water. 9 g of lauric acid and 5 g of 25% aqueous ammonia were added and mixed at 80 ° C. for 30 minutes, then cooled and diluted with water to obtain an anionic surface sizing agent having a solid content of 20%.
[0035]
Synthesis example 5
In a reaction vessel of a 0.5 L four-necked flask equipped with a stirrer and a thermometer, 350 g of water and 100 g of bulk polymerization SMA 2000A (manufactured by Elf Atchem Japan Ltd .: styrene-maleic acid resin, acid value 350) The temperature was raised to 75 ° C. with stirring. Separately, 48.8 g of 25% aqueous ammonia was prepared in a dropping funnel and dropped into the reaction vessel in 30 minutes. Further, the mixture was kept at 85 ° C. for 2 hours and dissolved by saponification. After charging 11 g of capric acid at 80 ° C. for 30 minutes, the mixture was cooled and diluted with water to obtain an anionic surface sizing agent having a solid content of 20%.
[0036]
Synthesis Example 6
A polymer aqueous solution for a surface sizing agent having a solid content of 20% and containing no fatty acid was obtained in the same manner as in Synthesis Example 1 except that no capric acid was added in Synthesis Example 1.
[0037]
Synthesis example 7
A polymer aqueous liquid for a surface sizing agent containing no fatty acid having a solid content of 20% was obtained in the same manner as in Synthesis Example 2 except that lauric acid was not added in Synthesis Example 2.
[0038]
Synthesis Example 8
A polymer aqueous liquid for a surface sizing agent containing no fatty acid having a solid content of 20% was obtained in the same manner as in Synthesis Example 3 except that no coconut fatty acid was added in Synthesis Example 3.
[0039]
Synthesis Example 9
Add coconut fatty acid 20g, neutralizing 25% aqueous ammonia and water 73.4g to 482g of 20% polymer aqueous solution for surface sizing agent of Synthesis Example 6 and mix at 85 ° C for 30 minutes, anionic with 20% solid content A surface sizing agent was obtained.
[0040]
Synthesis Example 10
460 g of tall oil fatty acid (manufactured by Harima Chemicals Co., Ltd .: FA-1, oleic acid and linoleic acid as main components) in 460 g of 20% polymer aqueous solution for surface sizing agent of Synthesis Example 8 and ammonia water for neutralization 33.5 g of water was added and mixed at 85 ° C. for 30 minutes to obtain an anionic surface sizing agent having a solid content of 20%.
[0041]
Synthesis Example 11
A 1 L four-necked flask equipped with a stirrer and a thermometer was charged with 50 g of toluene, 2.5 g of maleic anhydride, 9 g of acrylic acid and 38.5 g of styrene, and the temperature was raised to the reflux temperature with stirring. Separately, 10 g of toluene, 2.5 g of maleic anhydride, 9 g of acrylic acid, 38.5 g of styrene, 1.5 g of azoisobutyronitrile and 0.6 g of N-dodecyl mercaptan were charged into a dropping funnel over 1 hour. The solution was dropped into the reaction vessel and further aged at reflux temperature for 4 hours. After cooling, 32.9 g of 48% potassium hydroxide and 300 g of water were added dropwise to effect saponification and dissolution. Next, it heated to recirculation | reflux temperature and distilled toluene off. It was cooled and diluted with water to obtain a water-soluble resin having a solid content of 20%.
[0042]
A 1 L four-necked flask equipped with a stirrer and a thermometer was charged with 400 g of the water-soluble resin, 180 g of water, and 1.2 g of sodium dodecylbenzenesulfonate as a low molecular weight anionic surfactant, and heated to 90 ° C. A monomer mixture of 25 g of 4% potassium persulfate aqueous solution, 78 g of styrene, 12 g of acrylic acid-2-ethylhexyl, and 30 g of isobutyl methacrylate was separately added dropwise over 3 hours, and emulsion polymerization was performed. After cooling, 12.7 g of ammonia water and 22.2 g of lauric acid were added, mixed at 85 ° C. for 30 minutes, and diluted with water to obtain a surface sizing agent having a solid content concentration of 25%.
[0043]
Synthesis Examples 12-20
Each anionic surface sizing agent of Synthesis Examples 12 to 20 was obtained by adding and mixing each fatty acid shown in Table 1 and 25% aqueous ammonia for neutralization at 85 ° C. or higher to 414 g of 20% aqueous polymer solution for surface sizing agent of Synthesis Example 7. It was.
In Table 1, polymer solid content and fatty acid addition amount indicate polymer solid content and fatty acid content in the surface sizing agent solid content. In the fatty acids shown in Table 1, T fatty acid represents tall oil fatty acid, and HO stearic acid represents hydroxystearic acid.
[0044]
The stability evaluation shown in Table 1 evaluates the properties of the liquid when a sizing agent having a solid content of 20% is left at 10 ° C. for 1 month according to the following criteria.
<Stability evaluation criteria>
○: Stable
Δ: Slightly separated interface
Δ- ×: Some fatty acids are separated at the interface
×: Fatty acid separation and aggregation
[0045]
[Table 1]

<Polymer composition symbol>
ST: Styrene
nBA: n-butyl acrylate
MA: Methacrylic acid
AA: Acrylic acid
tBMA: t-butyl methacrylate
DIB: Diisobutylene
Manh: Maleic anhydride
EHA: 2-ethylhexyl acrylate
iBMA: Isobutyl methacrylate
[0046]
<Coating test for surface sizing agent on PPC base paper containing 70% deinked waste paper pulp>
Example 1
The surface sizing agent of Synthesis Example 1 was dissolved in a gelatinized solution of oxidized starch (MS-3800: manufactured by Nippon Shokuhin Kako Co., Ltd.) to prepare a coating solution containing 5% oxidized starch and 0.2% surface sizing agent.
Prepare a base paper for PPC (basis weight 65g / m2, internal sizing agent AKD, Steecht size degree 10 seconds) with 70% uncoated deinked waste paper pulp, and absorb with a lab size press at a coating liquid temperature of 50 ° C. Liquid volume 30g / m²And then passed through a 90 ° C. rotary drum dryer for 90 seconds to obtain a surface-sized coated paper.
[0047]
Example 23
  Synthesis example 23Example 2 was conducted in the same manner as in Example 1 except that the surface sizing agent was used.3Coated paper was obtained.
Reference Examples 1-2
Coated paper of Reference Examples 1 and 2 was obtained in the same manner as in Example 1 except that the surface sizing agents of Synthesis Examples 4 to 5 were used.
[0048]
Reference Examples 3-11
  Except for using the surface sizing agents of Synthesis Examples 9 to 17, the same as in Example 1Reference Examples 3-11Coated paper was obtained.
[0049]
Reference Example 12
  Ammonium salt of lauric acid and the surface sizing agent of Synthesis Example 8 were dissolved in a gelatinized solution of oxidized starch (MS-3800: manufactured by Nippon Shokuhin Kako), 5% oxidized starch, 0.04% ammonium laurate, Synthesis Example 8 A coating solution containing 0.16% of the surface sizing agent was prepared. Using this coating liquid and the same PPC base paper as in Example 1, a surface-sized coated paper was obtained in the same manner as in Example 1.
[0050]
Comparative Example 1
The surface sizing agent of Synthesis Example 8 was dissolved in a gelatinized solution of oxidized starch (MS-3800: manufactured by Nippon Shokuhin Kako) to prepare a coating solution containing 5% oxidized starch and 0.3% surface sizing agent. Using this coating liquid and using the same PPC base paper as in Example 1, a coated paper of Comparative Example 1 was obtained in the same manner as in Example 1.
[0051]
Comparative Examples 2-4
Coated papers of Comparative Examples 2 to 4 were obtained in the same manner as in Example 1 except that the surface sizing agents of Synthesis Examples 6 to 8 were used.
[0052]
Reference Examples 13-15
  Except for using the surface sizing agent of Synthesis Examples 18-20, the same as in Example 1Reference Examples 13-15Coated paper was obtained.
[0053]
<Performance test of coated paper>
(1) Stichtite sizing degree: The squeecht sizing degree (water resistance) of the paper was measured based on JIS P8122. It shows that water resistance is so high that a numerical value (second) is high.
(2) Inkjet suitability: For coated paper, print each pattern with Canon Inc. inkjet printer BJ 10vlite (dye black ink) and BJ S600 (pigment black ink), and evaluate the following. went.
(2-1) Feathering: Based on the “standard smear sample” described in the “Pen writing size test method” of the TAPPI paper pulp test method (No. 12), a six-step evaluation (good (no whiskers) 6-1 poor) in monochrome printing was performed. went.
(2-2) Back-through: The monochrome solid print portion was visually observed from the back side of the paper, and the back-through of the ink was evaluated on a four-point scale (good −-−- △ -x bad).
(2-3) Bleeding: The boundary bleeding state of yellow and black mixed color pattern printing was visually evaluated with the above-described inkjet printer BJ S600 (good −- ○ -Δ-x bad).
[0054]
  Table 2 shows the Steecht sizing degree of the coated paper of each Example and Comparative Example and the coating performance test result in ink jet printing.
[Table 2]

  According to the performance test results in Table 2, it can be seen that the coated paper according to the present invention is effective for feathering and back-through of inkjet printing.
[0055]
【The invention's effect】
According to the anionic papermaking surface sizing agent of the present invention, a printing paper using the same, and a method for producing a printing paper, even if it is a deinked wastepaper pulp-containing paper, it is equivalent to an inkjet printing paper not containing deinked wastepaper pulp With the amount of sizing agent applied, it is possible to suppress the occurrence of printing whisker and feathering, and it is possible to obtain printing performance equivalent to that of printing paper containing no deinked waste paper pulp.

Claims (6)

Hydrophobic group-containing polycarboxylic acid type anionic paper surface, characterized in that the polymerization reaction of the hydrophobic group-containing polycarboxylic acid type polymer is carried out in the presence of fatty acids or salts thereof to contain fatty acids or salts thereof Sizing agent.   The surface sizing agent for papermaking according to claim 1, wherein the content of the fatty acids or a salt thereof is 3 to 25% by weight of the solid content of the surface sizing agent.   The surface sizing agent for papermaking according to claim 1 or 2, wherein the fatty acid is a saturated or unsaturated fatty acid having 6 to 18 carbon atoms or a saturated or unsaturated hydroxy fatty acid having 6 to 18 carbon atoms. A printing paper which is surface-sized using the papermaking sizing agent according to any one of claims 1 to 3 . The printing paper according to claim 4, which is a deinked waste paper-containing pulp. The printing paper according to claim 5, which is an inkjet printing paper containing deinked waste paper pulp.