JPH0463007B2 - - Google Patents

Info

Publication number
JPH0463007B2
JPH0463007B2 JP12729284A JP12729284A JPH0463007B2 JP H0463007 B2 JPH0463007 B2 JP H0463007B2 JP 12729284 A JP12729284 A JP 12729284A JP 12729284 A JP12729284 A JP 12729284A JP H0463007 B2 JPH0463007 B2 JP H0463007B2
Authority
JP
Japan
Prior art keywords
powder
silicic acid
oil absorption
paper
hydrated silicic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
JP12729284A
Other languages
Japanese (ja)
Other versions
JPS618131A (en
Inventor
Toyozo Iwamoto
Suekichi Nakao
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tokuyama Corp
Original Assignee
Tokuyama Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tokuyama Corp filed Critical Tokuyama Corp
Priority to JP12729284A priority Critical patent/JPS618131A/en
Publication of JPS618131A publication Critical patent/JPS618131A/en
Publication of JPH0463007B2 publication Critical patent/JPH0463007B2/ja
Granted legal-status Critical Current

Links

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
    • D21H17/63—Inorganic compounds
    • D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
    • D21H17/69—Water-insoluble compounds, e.g. fillers, pigments modified, e.g. by association with other compositions prior to incorporation in the pulp or paper

Landscapes

  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Silicon Compounds (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Paper (AREA)

Description

【発明の詳細な説明】[Detailed description of the invention]

本発明は新規な複合粉体の製造方法に関する。
詳しくは、紙の填料として使用した場合、インク
の裏抜け防止効果が極めて優れた複合粉体を製造
する方法である。 従来より、紙の軽量化においては、吸油量の大
きい填料を使用することにより、インクの裏抜け
防止効果を高め、紙厚を薄くする方法が検討され
ている。例えば、特定の条件下で珪酸アルカリと
酸とを反応させて吸油量の大きい水和珪酸を生成
せしめ、これを紙の填料として添加する方法があ
る。 しかしながら、上記水和珪酸は、パルプスラリ
ー中に添加して抄紙した場合、該粉体の吸油量に
比して得られる紙のインクの裏抜け防止効果が充
分に発揮されないという問題を有する。即ち、吸
油量の異なる水和珪酸を、夫々パルプスラリー中
に添加して抄紙した場合、吸油量の増加に対して
得られる紙のインクの裏抜け防止効果の向上が少
ないという現象が生じ、紙の軽量化において大き
な問題となつていた。 本発明者等は上記問題を解消すべく研究を重ね
た。その結果、上記問題が抄紙の際、パルプスラ
リー中において水和珪酸の凝集構造が変化し、乾
燥後の吸油量が低下することに起因するという知
見を得た。上記知見に基づき、更に研究を重ねた
結果、水和珪酸と特定の粉体とよりなる粉体混合
物を特定条件下に粉砕し、再凝集させて得られる
複合粉体が、水に浸漬後の吸油量の低下が極めて
少なく、填料としてパルプスラリーに添加して抄
紙した場合においても、紙のインクの裏抜け防止
に優れた効果を発揮し得ることを見い出し、本発
明を完成した。 本発明は、水和珪酸と等電点が７以上の粉体と
の混合物を、嵩比重が0.18ｇ／c.c.以下となるよう
に粉砕することを特徴とする複合粉体の製造方法
である。 尚、本発明において、嵩比重はJISK6220によ
つて測定した値をいう。 本発明において、水和珪酸は珪酸アルカリと酸
との中和反応による、所謂湿式法によつて得られ
るものが特に制限なく使用される。特に、吸油量
が２c.c.／ｇ以上、好ましくは2.5〜４c.c.／ｇのも
のが、紙の填料として使用した場合にインクの裏
抜け防止効果が優れた複合粉体を得ることができ
好ましい。 上記含水珪酸の代表的な製法を例示すれば、次
のような方法がある。即ち、原料例えば珪酸アル
カリを鉱酸例えば硫酸で分解する時珪酸アルカリ
水溶液中に鉱酸を２分して加えて含水珪酸を生成
させる方法が好ましい。一般には添加する全鉱酸
量に対して37〜45％を初回に、出来るだけ速やか
に、例えば10分以内に添加するのが好ましい。ま
た上記珪酸アルカリ水溶液中に鉱酸を添加し珪酸
アルカリを分解する時の温度は高い方が好まし
く、一般には85℃〜95℃の温度が好適である。勿
論、これらの条件は原料の種類、反応装置などに
よつて異なるので予め決定する必要がある。 また、本発明において、水和珪酸と混合する粉
体として、等電点が７以上、好ましくは８以上の
粉体を用いることが極めて重要である。即ち、等
電点が７より低い粉体を用いて水和珪酸と共に後
述する特定の粉砕を行なつても、得られる複合粉
体は、水に浸漬後乾燥すると吸油量が著しく低下
し、これによる紙のインクの裏抜け防止効果は
夫々の粉体を単独で使用した場合における効果を
超えることはなく、むしろ低下する傾向にある。
これに対して、前記特定の等電点を有する粉体を
水和珪酸と共に粉砕して得られる複合粉体は、水
に浸漬後乾燥しても吸油量の低下が極めて少な
く、夫々の粉体を単独で使用した場合に比べてイ
ンクの裏抜け防止効果が著しく向上するのであ
る。本発明に使用される等電点が７以上の粉体と
しては、水に難溶性のものが好適に使用される。
例えば、炭酸カルシウム、炭酸マグネシウム、ア
ルミナ、水酸化アルミニウム、酸化亜鉛、酸化マ
グネシウム等の粉体の一種又は二種以上の組合せ
が好適である。そのうち、特に炭酸カルシウムが
好ましく使用される。 前記した水和珪酸と等電点が７以上の粉体との
混合割合は、水和珪酸／等電点が７以上の粉体比
が重量で４〜47、好ましくは５〜20とするのが、
水和珪酸による高い吸油量を維持し、紙のインク
の裏抜け防止効果の特に優れた複合粉体を得るた
めに望ましい。 本発明において、水和珪酸と等電点が７以上の
粉体との混合物を、嵩比重が0.18ｇ／c.c.以下とな
るまで粉砕することが、前記した水和珪酸と特定
の粉体との組合せによる効果と相剰的に働き、得
られる複合粉体の水に浸漬後における吸油量の低
下を効果的に防止するために必要である。なお、
上記嵩比重は粉砕直後における嵩比重をいう。従
つて、得られた複合粉体を貯蔵或いは輸送する間
にその嵩比重を上昇せしめ、0.18ｇ／c.c.を越える
ものも本発明の効果を十分発揮し得るものであ
り、本発明の一実施態様に含まれる。粉砕によつ
て得られる複合粉体の嵩比重が前記範囲より大き
いと、夫々の粉体の粉砕が不充分なため、各粉体
間に強固な凝集が生成せず、目的とする複合粉体
が得られない。 前記した粉体の混合物を0.18ｇ／c.c.以下の嵩比
重となるまで粉砕する方法は特に限定されるもの
ではない。代表的な方法を例示すれば、流体エネ
ルギーミルによつて、その入口ノズルにおける流
体圧（以下、粉砕圧という）が５Kg／cm2以上、好
ましくは６〜20Kg／cm2となるように粉砕する方法
が挙げられる。上記流体エネルギーミルは、公知
のものが特に制限なく使用される。一般には、ジ
エツト・オー・マイザー（商品名）、ジエツトミ
ル（商品名）等が好適である。 以上の説明より理解される如く、本発明の方法
によつて得られる複合粉体は、水中に浸漬し、乾
燥した後の吸油量の低下が極めて少ないという性
能を有する。従つて、填料としてパルプスラリー
中に添加して抄紙した場合においても、紙中で優
れた吸油性を示し、インクの裏抜け防止に優れた
効果を示す。 本発明によつて得られる複合粉体が、前記した
性能を発揮する機構は明らかではないが、本発明
者等は表面の荷電状態の異なる粉体が特定の粒子
径以下に粉砕されることにより、単なる粉体の混
合とは異なる特異な凝集構造を形成することによ
るものと推定している。 以下、本発明を具体的に説明するため実施例を
示すが、本発明はこれらの実施例に限定されるも
のではない。 尚、実施例において、粉体の吸油量、粉体を水
に浸漬後の吸油量、印刷後のインクの裏付け度及
び平均粒径の測定は下記の方法によつて行なつ
た。 (i)吸油量 JISK−5101に準じて行なつた。 (ii) 水に浸漬後の吸油量 試料粉体を水に浸した後、過し、80℃で静
置乾燥した。次いで、100メツシユのふるい上
で、乾燥後のケークをほぐした後、吸油量を(i)
の方法により測定した。 (iii) 印刷インクの裏抜け度 試料紙を10枚重ねて、その表面の反射率（Ｒ
∞）を測定した。一方、上記試料紙１枚に裏か
ら黒色枚をあてて、表面の反射率（Ro）を測
定した。また、上記試料紙の片面の全面にオフ
セツト輪転機用黒色インクを塗り、乾燥後の反
対面（白紙側）の反射率（Ri）を測定した。
これらの測定値から、下記の式により、印刷前
の不透明度r1及び印刷後の不透明度r2を求め
た。 印刷前の不透明度r1（％）＝Ro／Ｒ∞×100 印刷後の不透明度r2（％）＝Ro／Ｒ∞×100 次いで、上記r1、r2を用い、印刷インクの裏
抜け度を下式により求めた。 印刷インクの裏抜け度（％）＝r1−r2／r1×100 裏抜け度が低い程、印刷インクの裏抜け防止
性が優れていると言える。 (iv) 平均粒度 Coulter Counter TA−（商品名：(株)日科
機製）を用いて粒度分布を測定し、50％におけ
る粒径を示した。 実施例 第１表に示す性状を有する水和珪酸と粉体とを
第１表に示す割合で混合した後、混合物をジエツ
ト・オー・マイザー（商品名）で第１表に示す粉
砕圧で粉砕した。得られた複合粉体の平均粒径、
吸油量、水に浸漬後の吸油量を第１表に示す。ま
た、得られた複合粉体を填料として用い下記の配
合割合で混合し、パルプ濃度１％のパルプスラリ
ーを調製し、JIS Ｐ−8209に準じて抄紙した。得
られた紙について、印刷後のインク裏抜け率を測
定した。結果を第１表に併せて示す。 ●配合割合パルプ(L.B.K.P) サイズ剤 填料（５％スラリー） 硫酸バンド（５％水溶液） 100重量部 １重量部 ５重量部 ３重量部 尚、表−１において、粒径は平均粒径を示す。 The present invention relates to a method for producing a novel composite powder.
Specifically, it is a method for producing a composite powder that has an extremely excellent ink strike-through prevention effect when used as a paper filler. Conventionally, in order to reduce the weight of paper, methods have been studied to increase the effect of preventing ink bleed through and reduce the paper thickness by using fillers with a large oil absorption amount. For example, there is a method in which an alkali silicate and an acid are reacted under specific conditions to produce hydrated silicic acid with a large oil absorption capacity, and this is added as a filler to paper. However, when the above-mentioned hydrated silicic acid is added to pulp slurry to make paper, there is a problem in that the resulting paper does not have a sufficient effect of preventing ink bleed-through compared to the oil absorption amount of the powder. In other words, when paper is made by adding hydrated silicic acids with different oil absorption amounts to the pulp slurry, a phenomenon occurs in which the effect of preventing ink bleed through the paper is less improved as the oil absorption increases. This has become a major problem in reducing the weight of The present inventors have conducted repeated research in order to solve the above problem. As a result, it was found that the above problem was caused by a change in the agglomerated structure of hydrated silicic acid in the pulp slurry during paper making, resulting in a decrease in oil absorption after drying. Based on the above knowledge, as a result of further research, we found that a composite powder obtained by crushing a powder mixture of hydrated silicic acid and a specific powder under specific conditions and re-agglomerating it after immersion in water. The present invention was completed based on the discovery that the decrease in oil absorption is extremely small, and that even when paper is made by adding it as a filler to pulp slurry, it can exhibit an excellent effect in preventing ink bleed through the paper. The present invention is a method for producing composite powder, which comprises pulverizing a mixture of hydrated silicic acid and powder having an isoelectric point of 7 or more so that the bulk specific gravity is 0.18 g/cc or less. In the present invention, bulk specific gravity refers to a value measured according to JISK6220. In the present invention, the hydrated silicic acid obtained by a so-called wet method, which is a neutralization reaction between an alkali silicate and an acid, can be used without particular limitation. In particular, to obtain a composite powder having an oil absorption of 2 c.c./g or more, preferably 2.5 to 4 c.c./g, which has an excellent ink strike-through prevention effect when used as a paper filler. This is preferable. Typical methods for producing the above-mentioned hydrated silicic acid include the following methods. That is, a method is preferred in which, when a raw material such as an alkali silicate is decomposed with a mineral acid such as sulfuric acid, the mineral acid is added in two parts to an aqueous aqueous silicate solution to produce hydrated silicic acid. Generally, it is preferable to add 37 to 45% of the total amount of mineral acid to be added initially as quickly as possible, for example within 10 minutes. Further, the temperature at which the mineral acid is added to the aqueous alkali silicate solution to decompose the alkali silicate is preferably higher, and generally a temperature of 85°C to 95°C is suitable. Of course, these conditions need to be determined in advance since they vary depending on the type of raw materials, reaction equipment, etc. Further, in the present invention, it is extremely important to use a powder having an isoelectric point of 7 or more, preferably 8 or more as the powder to be mixed with the hydrated silicic acid. In other words, even if a powder with an isoelectric point lower than 7 is used together with hydrated silicic acid and is subjected to the specific pulverization described below, the resulting composite powder will have a marked decrease in oil absorption when dried after immersion in water. The effect of preventing ink bleed through on paper does not exceed the effect when each powder is used alone, but rather tends to decrease.
On the other hand, composite powders obtained by grinding powders with the above-mentioned specific isoelectric points together with hydrated silicic acid exhibit extremely little decrease in oil absorption even when dried after being immersed in water. The effect of preventing ink bleed through is significantly improved compared to the case where the ink is used alone. The powder having an isoelectric point of 7 or more used in the present invention is preferably one that is sparingly soluble in water.
For example, one or a combination of two or more of powders such as calcium carbonate, magnesium carbonate, alumina, aluminum hydroxide, zinc oxide, and magnesium oxide are suitable. Among these, calcium carbonate is particularly preferably used. The mixing ratio of the above-mentioned hydrated silicic acid and the powder having an isoelectric point of 7 or more is such that the ratio of hydrated silicic acid/powder having an isoelectric point of 7 or more is 4 to 47, preferably 5 to 20 by weight. but,
This is desirable in order to obtain a composite powder that maintains a high oil absorption due to hydrated silicic acid and has a particularly excellent effect of preventing ink from bleed through paper. In the present invention, pulverizing a mixture of hydrated silicic acid and a powder having an isoelectric point of 7 or more until the bulk specific gravity becomes 0.18 g/cc or less is a method of combining the hydrated silicic acid and the specific powder described above. This is necessary in order to work in combination with the effects of the combination and to effectively prevent a decrease in oil absorption of the resulting composite powder after it is immersed in water. In addition,
The bulk specific gravity mentioned above refers to the bulk specific gravity immediately after crushing. Therefore, the effects of the present invention can be fully exhibited even when the bulk specific gravity of the obtained composite powder is increased during storage or transportation and exceeds 0.18 g/cc, and is an embodiment of the present invention. include. If the bulk specific gravity of the composite powder obtained by pulverization is larger than the above range, each powder will not be sufficiently pulverized, and strong agglomerations will not be formed between the individual powders, resulting in the formation of the desired composite powder. is not obtained. The method of pulverizing the above-mentioned powder mixture until it has a bulk specific gravity of 0.18 g/cc or less is not particularly limited. To give an example of a typical method, grinding is performed using a fluid energy mill so that the fluid pressure at the inlet nozzle (hereinafter referred to as grinding pressure) is 5 Kg/cm 2 or more, preferably 6 to 20 Kg/cm 2 There are several methods. Any known fluid energy mill may be used without particular limitation as the fluid energy mill. Generally, Jet-O-Mizer (trade name), Jet Mill (trade name), etc. are suitable. As can be understood from the above explanation, the composite powder obtained by the method of the present invention has the property of exhibiting extremely little decrease in oil absorption after being immersed in water and dried. Therefore, even when it is added to pulp slurry as a filler to make paper, it exhibits excellent oil absorption in the paper and exhibits an excellent effect in preventing ink strike-through. Although the mechanism by which the composite powder obtained by the present invention exhibits the above-mentioned performance is not clear, the present inventors have discovered that powders with different surface charge states are pulverized to below a specific particle size. It is presumed that this is due to the formation of a unique agglomerated structure that differs from the mere mixing of powders. Examples are shown below to specifically explain the present invention, but the present invention is not limited to these Examples. In the examples, the oil absorption amount of the powder, the oil absorption amount after immersing the powder in water, the degree of support of the ink after printing, and the average particle size were measured by the following methods. (i) Oil absorption It was conducted in accordance with JISK-5101. (ii) Oil absorption after immersion in water After immersing the sample powder in water, it was filtered and left to dry at 80°C. Next, after loosening the dried cake on a 100 mesh sieve, the oil absorption was determined as (i)
It was measured by the method of (iii) Degree of print ink bleed-through Layer 10 sample papers and measure the reflectance (R) of the surface.
∞) was measured. On the other hand, a black sheet was applied from the back to one of the sample papers to measure the reflectance (Ro) of the surface. Further, black ink for an offset rotary press was applied to the entire surface of one side of the sample paper, and after drying, the reflectance (Ri) of the opposite side (white paper side) was measured.
From these measured values, the opacity r 1 before printing and the opacity r 2 after printing were determined using the following formula. Opacity before printing r 1 (%) = Ro / R∞ × 100 Opacity after printing r 2 (%) = Ro / R∞ × 100 Next, using the above r 1 and r 2 , check for print ink bleed-through The degree was calculated using the following formula. Printing ink strike-through degree (%)=r 1 −r 2 /r 1 ×100 It can be said that the lower the strike-through degree is, the better the printing ink strike-through prevention property is. (iv) Average particle size The particle size distribution was measured using Coulter Counter TA- (trade name: manufactured by Nikkaki Co., Ltd.), and the particle size at 50% was shown. Example After mixing hydrated silicic acid having the properties shown in Table 1 and powder in the ratio shown in Table 1, the mixture was pulverized with a Jet-O-Mizer (trade name) at the crushing pressure shown in Table 1. did. The average particle size of the obtained composite powder,
Table 1 shows the oil absorption amount and the oil absorption amount after immersion in water. Further, the obtained composite powder was used as a filler and mixed at the following blending ratio to prepare a pulp slurry with a pulp concentration of 1%, and paper was made according to JIS P-8209. The ink strike-through rate after printing was measured for the obtained paper. The results are also shown in Table 1. ●Composition ratio Pulp (LBKP) Sizing agent filler (5% slurry) Band sulfate (5% aqueous solution) 100 parts by weight 1 part by weight 5 parts by weight 3 parts by weight In Table 1, the particle size indicates the average particle size.

【表】【table】

【表】【table】

Claims (1)

【特許請求の範囲】 １ 水和珪酸と等電点が７以上の粉体との混合物
を、嵩比重が0.18ｇ／c.c.以下となるように粉砕す
ることを特徴とする複合粉体の製造方法。 ２ 等電点が７以上の粉体が、炭酸カルシウム、
炭酸マグネシウム、アルミナ、水酸化アルミニウ
ム、酸化亜鉛及び酸化マグネシウムよりなる群か
ら選ばれた少なくとも一種の粉体である特許請求
の範囲第１項記載の方法。 ３ 水和珪酸／等電点が７以上の粉体の重量比が
４〜47である特許請求の範囲第１項記載の方法。 ４ 粉砕を流体エネルギーミルによつて５Kg／cm2
以上の粉砕圧で行なうことを特徴とする特許請求
の範囲第１項記載の方法。[Claims] 1. A method for producing a composite powder, which comprises pulverizing a mixture of hydrated silicic acid and a powder having an isoelectric point of 7 or more so that the bulk specific gravity is 0.18 g/cc or less. . 2 Powder with an isoelectric point of 7 or more is calcium carbonate,
The method according to claim 1, wherein the powder is at least one kind of powder selected from the group consisting of magnesium carbonate, alumina, aluminum hydroxide, zinc oxide, and magnesium oxide. 3. The method according to claim 1, wherein the weight ratio of hydrated silicic acid/powder having an isoelectric point of 7 or more is 4 to 47. 4 Grinding by fluid energy mill to 5Kg/cm 2
2. The method according to claim 1, wherein the method is carried out at a crushing pressure equal to or higher than that.
JP12729284A 1984-06-22 1984-06-22 Production of composite powder Granted JPS618131A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP12729284A JPS618131A (en) 1984-06-22 1984-06-22 Production of composite powder

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP12729284A JPS618131A (en) 1984-06-22 1984-06-22 Production of composite powder

Publications (2)

Publication Number Publication Date
JPS618131A JPS618131A (en) 1986-01-14
JPH0463007B2 true JPH0463007B2 (en) 1992-10-08

Family

ID=14956351

Family Applications (1)

Application Number Title Priority Date Filing Date
JP12729284A Granted JPS618131A (en) 1984-06-22 1984-06-22 Production of composite powder

Country Status (1)

Country Link
JP (1) JPS618131A (en)

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