JP4752442B2 - Hydrated silicic acid for papermaking and method for producing the same - Google Patents
Hydrated silicic acid for papermaking and method for producing the same Download PDFInfo
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- 235000012239 silicon dioxide Nutrition 0.000 title claims description 71
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 title claims description 69
- 238000004519 manufacturing process Methods 0.000 title claims description 12
- 239000002245 particle Substances 0.000 claims description 88
- 239000002253 acid Substances 0.000 claims description 30
- 239000011148 porous material Substances 0.000 claims description 26
- 229910052500 inorganic mineral Inorganic materials 0.000 claims description 20
- 239000011707 mineral Substances 0.000 claims description 20
- 238000003756 stirring Methods 0.000 claims description 20
- 239000002002 slurry Substances 0.000 claims description 19
- 238000010521 absorption reaction Methods 0.000 claims description 17
- 238000009826 distribution Methods 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 14
- 239000004115 Sodium Silicate Substances 0.000 claims description 12
- 239000007864 aqueous solution Substances 0.000 claims description 12
- 229910052911 sodium silicate Inorganic materials 0.000 claims description 12
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 claims description 12
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 claims description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 9
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 claims description 6
- 229910052753 mercury Inorganic materials 0.000 claims description 6
- 239000000377 silicon dioxide Substances 0.000 claims description 4
- 229910052938 sodium sulfate Inorganic materials 0.000 claims description 2
- 235000011152 sodium sulphate Nutrition 0.000 claims description 2
- 230000001186 cumulative effect Effects 0.000 claims 1
- 229960004029 silicic acid Drugs 0.000 description 62
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 50
- 238000006243 chemical reaction Methods 0.000 description 23
- 239000000945 filler Substances 0.000 description 17
- 239000003921 oil Substances 0.000 description 14
- 235000019198 oils Nutrition 0.000 description 14
- 239000000243 solution Substances 0.000 description 13
- 238000006386 neutralization reaction Methods 0.000 description 11
- 230000032683 aging Effects 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 6
- 229910052910 alkali metal silicate Inorganic materials 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 230000006872 improvement Effects 0.000 description 5
- 239000011164 primary particle Substances 0.000 description 5
- 239000000047 product Substances 0.000 description 5
- 239000011163 secondary particle Substances 0.000 description 5
- 230000003472 neutralizing effect Effects 0.000 description 4
- 230000035515 penetration Effects 0.000 description 4
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 3
- 238000000149 argon plasma sintering Methods 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 229910000019 calcium carbonate Inorganic materials 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 230000005484 gravity Effects 0.000 description 3
- 238000012423 maintenance Methods 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 238000013019 agitation Methods 0.000 description 2
- LRCFXGAMWKDGLA-UHFFFAOYSA-N dioxosilane;hydrate Chemical compound O.O=[Si]=O LRCFXGAMWKDGLA-UHFFFAOYSA-N 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- AMWRITDGCCNYAT-UHFFFAOYSA-L hydroxy(oxo)manganese;manganese Chemical compound [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 description 2
- 235000021388 linseed oil Nutrition 0.000 description 2
- 239000000944 linseed oil Substances 0.000 description 2
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 2
- 239000000347 magnesium hydroxide Substances 0.000 description 2
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 229960001866 silicon dioxide Drugs 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 239000013585 weight reducing agent Substances 0.000 description 2
- OQVYMXCRDHDTTH-UHFFFAOYSA-N 4-(diethoxyphosphorylmethyl)-2-[4-(diethoxyphosphorylmethyl)pyridin-2-yl]pyridine Chemical compound CCOP(=O)(OCC)CC1=CC=NC(C=2N=CC=C(CP(=O)(OCC)OCC)C=2)=C1 OQVYMXCRDHDTTH-UHFFFAOYSA-N 0.000 description 1
- 239000005995 Aluminium silicate Substances 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 239000004111 Potassium silicate Substances 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 1
- 229920001807 Urea-formaldehyde Polymers 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- AYJRCSIUFZENHW-DEQYMQKBSA-L barium(2+);oxomethanediolate Chemical compound [Ba+2].[O-][14C]([O-])=O AYJRCSIUFZENHW-DEQYMQKBSA-L 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 229910052570 clay Inorganic materials 0.000 description 1
- 239000011246 composite particle Substances 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 239000011256 inorganic filler Substances 0.000 description 1
- 239000010954 inorganic particle Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
- 239000001095 magnesium carbonate Substances 0.000 description 1
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- IPJKJLXEVHOKSE-UHFFFAOYSA-L manganese dihydroxide Chemical compound [OH-].[OH-].[Mn+2] IPJKJLXEVHOKSE-UHFFFAOYSA-L 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910000008 nickel(II) carbonate Inorganic materials 0.000 description 1
- ZULUUIKRFGGGTL-UHFFFAOYSA-L nickel(ii) carbonate Chemical compound [Ni+2].[O-]C([O-])=O ZULUUIKRFGGGTL-UHFFFAOYSA-L 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000012766 organic filler Substances 0.000 description 1
- 239000011146 organic particle Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- ODGAOXROABLFNM-UHFFFAOYSA-N polynoxylin Chemical compound O=C.NC(N)=O ODGAOXROABLFNM-UHFFFAOYSA-N 0.000 description 1
- 229910052913 potassium silicate Inorganic materials 0.000 description 1
- 235000019353 potassium silicate Nutrition 0.000 description 1
- NNHHDJVEYQHLHG-UHFFFAOYSA-N potassium silicate Chemical compound [K+].[K+].[O-][Si]([O-])=O NNHHDJVEYQHLHG-UHFFFAOYSA-N 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 125000005624 silicic acid group Chemical class 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 239000003981 vehicle Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
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- Silicon Compounds (AREA)
- Paper (AREA)
Description
本発明は、水和珪酸およびその製造方法に関する。特には、機械安定性、歩留まりなどの実用性に優れ、さらに抄紙に際し填料として使用した時に、高い不透明性を与える水和珪酸およびその製造方法に関する。 The present invention relates to hydrated silicic acid and a method for producing the same. In particular, the present invention relates to a hydrated silicic acid that is excellent in practicality such as mechanical stability and yield, and that provides high opacity when used as a filler in papermaking, and a method for producing the same.
通常、印刷或いは筆記用に使用される紙には、不透明度、白色度などの光学特性、平滑性、手触り、印刷適性、筆記適性等の改良のために、水和珪酸（含水ケイ酸）、タルク、炭酸カルシウム、クレー、カオリン、二酸化チタンなどの無機粒子や尿素−ホルムアルデヒドポリマー等の有機系の粒子が填料として添加使用されている。このような填料を内添した紙は、水に分散した製紙用パルプに填料を添加し、その他、通常紙の抄造に使用される内添助剤を添加した紙料から、長網抄紙機、ツインワイヤ抄紙機等によって湿紙を形成し、乾燥して製造されている。 Usually, paper used for printing or writing is hydrated silicic acid (hydrous silicic acid) for improving optical properties such as opacity and whiteness, smoothness, touch, printability, writing suitability, etc. Inorganic particles such as talc, calcium carbonate, clay, kaolin and titanium dioxide, and organic particles such as urea-formaldehyde polymer are used as fillers. Paper internally added with such fillers is made by adding fillers to paper-making pulp dispersed in water, and other papers added with internal additives that are usually used for papermaking. It is manufactured by forming wet paper with a twin wire paper machine and drying it.
近年、紙は厚みを減少させて軽量化される傾向にあるが、特に印刷用紙を軽量化すると紙に印刷した場合の不透明度（以下、印刷後不透明度と称する）が低下し、印字が紙の反対面から透き通ってみえるという問題が生じる。印刷後不透明度も含め、紙の不透明度を向上させるために紙に様々な填料を添加することが一般に行われている。不透明度を向上させるという目的のために無機系及び有機系の各種填料の研究開発が行われているが、現在においても、なお安価で十分に不透明度の向上効果のあるものは開発されるに至っていない。また、最近ではより一層軽量化が促進される傾向が強いので、既存の填料より更に不透明度を向上させる能力を持った填料の出現が強く望まれている。 In recent years, paper tends to be reduced in weight by reducing the thickness. However, when printing paper is reduced in weight, opacity (hereinafter referred to as post-printing opacity) when printed on paper is reduced, and printing is performed on paper. The problem arises that it can be seen through from the opposite side. In order to improve the opacity of paper, including opacity after printing, various fillers are generally added to the paper. Research and development of various inorganic and organic fillers has been conducted for the purpose of improving opacity, but even now, those that are still inexpensive and have sufficient opacity improvement effects will be developed. Not reached. In addition, since there is a strong tendency to promote weight reduction recently, the emergence of fillers having the ability to improve opacity further than existing fillers is strongly desired.
現在使用されている不透明度向上用の填料の中で、酸化チタンは、白紙不透明度は向上させるが、インキの浸透を抑制する能力が劣っているために印刷後不透明度の向上が望めなく、更に光散乱能を最大に発揮できる状態（粒子径０．１〜０．５μｍ）においては、パルプに添加して抄紙する際の歩留りが非常に悪く、不経済である。炭酸カルシウムは安価であるが、歩留まりが悪く、吸油性能が乏しいため印刷後不透明度向上効果は低レベルである。有機系の尿素−ホルマリン樹脂は、印刷後不透明度及び白紙不透明度の向上能力を合わせ持ってはいるが、各々の絶対能力が不足している。水和珪酸は、他の種類の填料より価格も安く、また、パルプに添加して抄紙した場合、インクの浸透を抑制することによる印刷後不透明度を付与する効果がある。しかし、印刷後不透明度は今後の紙軽量化に更なる向上が望まれており、原料の有効利用の観点からも高い歩留まりを与えることが望まれている。 Among the currently used fillers for improving opacity, titanium oxide improves white paper opacity, but it cannot be expected to improve opacity after printing due to its poor ability to suppress ink penetration. Furthermore, in a state where the light scattering ability can be maximized (particle diameter of 0.1 to 0.5 μm), the yield when making paper by adding to pulp is very poor, which is uneconomical. Calcium carbonate is inexpensive, but its yield is poor and its oil absorption performance is poor, so the effect of improving opacity after printing is low. The organic urea-formalin resin has both the ability to improve the opacity after printing and the blank paper opacity, but lacks the absolute ability of each. Hydrated silicic acid is cheaper than other types of fillers, and when added to pulp to make paper, it has the effect of imparting opacity after printing by inhibiting ink penetration. However, further improvement in opacity after printing is desired for future paper weight reduction, and it is desired to provide a high yield from the viewpoint of effective use of raw materials.
水和珪酸では、印刷後不透明度の向上に大きく寄与しているインクの浸透を抑制する能力の指標となる吸油量は、水和珪酸の細孔体積に比例して大きくなり、水和珪酸の合成条件により制御できることが知られている。しかし、現在使用されている水和珪酸より細孔体積を大きくしていくと、空隙の増加による粒子の強度低下が生じ、さまざまな攪拌装置やポンプを経て抄紙する際も機械的摩擦力により粒子が破壊されることもある。また、合成された水和珪酸は、均一な粒度を持っているわけではなく、粒度分布の広がりが大きいときには、小さな粒子は歩留まり低下の原因となり、大きな粒子は紙の表面から突出することによる脱落、即ち紙粉の原因となりうる。 In hydrated silicic acid, the oil absorption, which is an index of the ability to suppress ink penetration, which contributes greatly to the improvement in opacity after printing, increases in proportion to the pore volume of hydrated silicic acid. It is known that it can be controlled by synthesis conditions. However, if the pore volume is made larger than the hydrated silicic acid currently used, the strength of the particles is reduced due to the increase in voids, and even when paper is made through various agitators and pumps, the mechanical friction force causes May be destroyed. In addition, the synthesized hydrated silica does not have a uniform particle size. When the particle size distribution is wide, small particles cause a decrease in yield, and large particles fall off due to protruding from the paper surface. That is, it can cause paper dust.
特許文献１特許に開示されている水和珪酸では、吸油量が２５０〜３５０ｍｌ／１００ｇと小さいために印刷後不透明度の向上が劣っており、また粒子径がレーザー法による測定値で３〜１５μｍであるため抄紙機における歩留まりが悪く、また歩留まり向上剤などを用いて凝集させると紙の中での均一性が失われることにより更なる印刷後不透明度の低下へとつながる。
特許文献２に開示されている「複合粒子の製造方法」で得られる水和珪酸誘導体では、優れた光散乱能による不透明度向上は達成できるが、吸油量が３５０ｍｌ／１００ｇ程度しかない。また、粒径分布も特に優れているとはいえない。
In the hydrated silicic acid disclosed in Patent Document 1, the oil absorption is as small as 250 to 350 ml / 100 g, so the improvement in opacity after printing is inferior, and the particle diameter is 3 to 15 μm as measured by the laser method. Therefore, the yield in the paper machine is poor, and if the agglomeration is performed using a yield improver or the like, the uniformity in the paper is lost, leading to a further decrease in opacity after printing.
The hydrated silicic acid derivative obtained by the “method for producing composite particles” disclosed in Patent Document 2 can achieve improvement in opacity due to excellent light scattering ability, but the oil absorption is only about 350 ml / 100 g. Also, the particle size distribution is not particularly excellent.
特許文献３に開示されている製紙用水和珪酸では、吸油量が３５０ｍｌ／１００ｇ程度しかなく、また、粒径分布も特に優れているとはいえない。
さらに、特許文献４に開示されている「シリカ粒子、その製造方法及びシリカ粒子内添紙」に記載の水和珪酸は、吸油量が３００〜５００ｍｌ／１００ｇ、細孔容積４．０〜６．０ｃｃ／ｇと非常に優れており印刷後不透明度に対する効果は大きく、平均粒子径は５〜３０μｍで粒子径（μｍ）を対数で表示したときの粒子径に対する粒子体積の分布の標準偏差が０．１〜０．２５で極めてシャープであり、歩留まり、紙粉などに優れていると思われる。しかし、意外なことに、該水和珪酸を用いて抄紙してみると、抄紙過程における歩留まりが高くない場合があることが判明した。特に、機械的摩擦力が強くかかる場合に、粒子が破壊され、結局は粒子径が１５μｍを下回るような小さな粒子になってしまうのではないかと推定している。
Furthermore, the hydrated silicic acid described in “Silica Particles, Method for Producing the Same and Silica Particle-Incorporated Paper” disclosed in Patent Document 4 has an oil absorption of 300 to 500 ml / 100 g and a pore volume of 4.0 to 6. It is very excellent at 0 cc / g and has a great effect on the opacity after printing. The standard deviation of the distribution of the particle volume with respect to the particle size when the average particle size is 5 to 30 μm and the particle size (μm) is expressed in logarithm is 0. .1 to 0.25, which is very sharp and seems to be excellent in yield and paper dust. However, surprisingly, it was found that when the paper was made using the hydrated silicic acid, the yield in the paper making process might not be high. In particular, it is estimated that when a mechanical frictional force is applied, the particles are destroyed and eventually become small particles having a particle diameter of less than 15 μm.
本発明では、安価なケイ酸ナトリウム等を原料として使用し、製紙用填料として機械安定性、歩留まりなどの実用性に優れ、さらに抄紙に際し填料として使用した時に高い不透明性を与える水和珪酸、およびその製造方法を提供することを課題とする。 In the present invention, an inexpensive sodium silicate or the like is used as a raw material, hydrated silicic acid that is excellent in practicality such as mechanical stability and yield as a papermaking filler, and further provides high opacity when used as a filler in papermaking, and It is an object to provide a manufacturing method thereof.
上記課題を解決するため、本発明は以下の（１）〜（４）の構成を採用する。
（１） 平均粒子径がレーザー法による測定値で１５〜３０μｍかつＪＩＳ Ｋ−５１０１の方法で測定した吸油量が３６０〜５００ｍｌ／１００ｇである水和珪酸において、粒子径（μｍ）を対数で表示したときの粒子径に対する粒子体積の分布の標準偏差が０．３〜０．４である水和珪酸。
（２） 水銀ポロシメーターで測定した細孔半径１０５Å以下の細孔の積算容量が４．０ｃｃ／ｇ以上であり、比表面積が５０〜１４０ｍ２／ｇであることを特徴とする（１）に記載の水和珪酸。
（３） 上記の（１）または（２）に記載の発明において、水和珪酸の１０％スラリー２Ｌをタービン羽根により１０００ｒｐｍで１２０分攪拌処理した時の平均粒子径が、処理前の平均粒子径の９５％以上を維持すること特徴とする水和珪酸。
（４） 硫酸ナトリウムの存在下で、ケイ酸ソーダ水溶液に鉱酸を二段に分けて添加し、中和して製紙用水和珪酸を製造する際に、第一の鉱酸として、該ケイ酸ソーダを中和するのに必要な全量の２０〜５０％に相当する鉱酸を２０〜６０℃において添加して、次いで撹拌しながら７０℃以上に昇温し、残部の鉱酸（第二の鉱酸）を添加する方法において、第二の鉱酸の添加を開始するまでに水和珪酸１ｋｇあたりに、１５０〜３００ｋＪの攪拌負荷を付与することを特徴とする上記（１）〜（３）のいずれかに記載の水和珪酸の製造方法。
In order to solve the above problems, the present invention employs the following configurations (1) to (4).
(1) In hydrated silicic acid having an average particle size of 15 to 30 μm measured by the laser method and an oil absorption measured by the method of JIS K-5101 of 360 to 500 ml / 100 g, the particle size (μm) is displayed in logarithm. A hydrated silicic acid having a standard deviation of the particle volume distribution with respect to the particle diameter.
(2) The integrated capacity of pores having a pore radius of 10 5 mm or less measured with a mercury porosimeter is 4.0 cc / g or more, and the specific surface area is 50 to 140 m 2 / g (1) The hydrated silicic acid described in 1.
(3) In the invention described in the above (1) or (2), the average particle diameter when 2 L of 10% slurry of hydrated silicic acid is stirred by a turbine blade at 1000 rpm for 120 minutes is the average particle diameter before treatment A hydrated silicic acid characterized by maintaining 95% or more of the above.
(4) In the presence of sodium sulfate, mineral acid is added to sodium silicate aqueous solution in two stages, and neutralized to produce hydrated silicic acid for papermaking. Mineral acid corresponding to 20 to 50% of the total amount required to neutralize soda was added at 20 to 60 ° C., then the temperature was raised to 70 ° C. or higher with stirring, and the remaining mineral acid (secondary acid was added). (1) to (3), wherein a stirring load of 150 to 300 kJ is applied to 1 kg of hydrated silicic acid before the addition of the second mineral acid is started. The manufacturing method of hydrated silicic acid in any one of.
本発明により、印刷用紙用の填料として用いた時に、高い不透明性を与えることができ、また、使用時の機械安定性に優れるため、結果として歩留まりが向上する。本発明で得られたような高い不透明性と機械安定性を両立する水和珪酸は本発明により始めて得られるものである。 According to the present invention, when used as a filler for printing paper, high opacity can be imparted, and since the mechanical stability during use is excellent, the yield is improved as a result. The hydrated silicic acid having both high opacity and mechanical stability obtained by the present invention is obtained for the first time by the present invention.
＜水和珪酸の物性＞
製紙用の填料として、高速で生産される新聞用紙のような紙製品においては、既に記載したように水和珪酸が好んで用いられるが、その形状についてはワイヤーパートにおける脱水時の吸引力が強いため、填料の粒子径はレーザー法による測定値で１５〜３０μｍであることが歩留まりの観点から望ましい。留まりを高めるために無機或いは有機の歩留まり向上剤を添加する方法もあるが、添加率が高くなると紙の地合を損ねることになり、限度がある。また３０μｍを超す場合は、紙中への留まりは極めて良いが、紙中に存在する粒子個数が減少するため、水和珪酸の持つ光散乱効果が減少し、ひいては、紙の不透明度が減少することになる。
<Physical properties of hydrated silicic acid>
Hydrated silicic acid is preferably used for paper products such as newsprint produced at high speed as a filler for papermaking, as described above, but its shape has a strong suction force during dehydration in the wire part. Therefore, it is desirable from the viewpoint of yield that the particle diameter of the filler is 15 to 30 μm as measured by a laser method. In order to increase the yield, there is a method of adding an inorganic or organic yield improver. However, when the addition rate is increased, the formation of the paper is impaired and there is a limit. When the thickness exceeds 30 μm, the retention in the paper is very good, but the number of particles existing in the paper decreases, so the light scattering effect of hydrated silicic acid decreases, and the opacity of the paper decreases. It will be.
また、特に高い印刷後不透明度を要求されるためＪＩＳ Ｋ−５１０１の方法で測定した吸油量が３６０〜５００ｍｌ／１００ｇである水和珪酸が望まれるている。また、本発明による水和珪酸は、嵩比重が０．１５ｇ／ｍｌ以下であり、より好ましくは０．０６〜０．１２ｇ／ｍｌである。嵩比重が０．１５ｇ／ｍｌ以下のような小さな値となることで、紙に添加したときに紙の中でより多くの体積を占め、よりインクの吸収に寄与すると思われる。嵩比重が０．１５ｇ／ｍｌより大きい場合は、このような効果は低いレベルとなる。 In addition, since particularly high opacity after printing is required, hydrated silicic acid having an oil absorption measured by the method of JIS K-5101 of 360 to 500 ml / 100 g is desired. The hydrated silicic acid according to the present invention has a bulk specific gravity of 0.15 g / ml or less, more preferably 0.06 to 0.12 g / ml. When the bulk specific gravity is a small value such as 0.15 g / ml or less, it seems that when added to paper, it occupies a larger volume in the paper and contributes to more ink absorption. When the bulk specific gravity is greater than 0.15 g / ml, such an effect is at a low level.
このような水和珪酸において、粒子径の分布は重要であり、５０μｍを超えるような大きな粒子は紙製品の表面性を乱すのみならず、印刷時の粉落ち現象にもつながるため好ましくなく、また１０μｍを下回るような小さな粒子は歩留まりが悪いために好ましくない。
これらの事実から、本発明者らは、粒度分布はシャープであることが望ましく、粒子径（μｍ）を対数で表示したときの粒子径に対する粒子体積の分布の標準偏差は小さい程好ましいと考えていた。
しかし、標準偏差が著しく小さい水和珪酸は機械的安定性が劣っていることが確認された。これは水和珪酸が一次粒子の凝集体であることに起因すると思われる。すなわち、二次粒子径の分布がシャープな水和珪酸の一次粒子径の分布は同様にシャープであることが予想され、その結果として凝集体の結合力が弱くなり機械安定性が劣ると推定した。そして、種々の条件で上記測定法による標準偏差の値を変化させて実験したところ、上記測定法による標準偏差０．３〜０．４の範囲が機械的安定性に優れていることを発見し、本発明に到達した。
このような物性を持つ水和珪酸は機械的安定性が優れており、攪拌によるシェアを受けた場合でも粒子の状態を維持できるため、紙製品中でも当初持ち合わせたインキ吸収力や歩留まり特性を発揮することができる。この指標として、水和珪酸の濃度１０％で水に分散したスラリー２Ｌをタービン羽根により１０００ｒｐｍで１２０分攪拌した時の平均粒子径は、処理前の平均粒子径の９５％以上を維持することでも特徴付けることができる。
In such hydrated silicic acid, the particle size distribution is important, and large particles exceeding 50 μm are not preferable because they not only disturb the surface properties of paper products, but also lead to powder-off phenomenon during printing. Small particles smaller than 10 μm are not preferable because of poor yield.
From these facts, the present inventors believe that the particle size distribution is desirably sharp, and that the standard deviation of the particle volume distribution with respect to the particle size when the particle size (μm) is expressed in logarithm is preferably as small as possible. It was.
However, it was confirmed that hydrated silicic acid with a remarkably small standard deviation has poor mechanical stability. This seems to be due to the fact that hydrated silicic acid is an aggregate of primary particles. In other words, the primary particle size distribution of hydrated silicic acid with a sharp secondary particle size distribution is expected to be sharp as well, and as a result, the cohesive strength of the aggregates becomes weak and the mechanical stability is inferior. . Then, when the experiment was performed by changing the standard deviation value according to the measurement method under various conditions, it was found that the standard deviation range of 0.3 to 0.4 according to the measurement method was excellent in mechanical stability. The present invention has been reached.
Hydrated silicic acid with such physical properties is excellent in mechanical stability and can maintain the particle state even when subjected to a share by stirring, so it exhibits the ink absorption and yield characteristics originally possessed even in paper products. be able to. As this index, the average particle diameter when 2 L of slurry dispersed in water at a concentration of 10% of hydrated silicic acid is stirred at 1000 rpm for 120 minutes with a turbine blade can be maintained at 95% or more of the average particle diameter before treatment. Can be characterized.
さらに、この水和珪酸の一次粒子レベルにおける比表面積が小さすぎると粒子同士の結合力低下が起こり、比表面積が大きすぎると一次粒子径が小さいことからくると思われる二次粒子の圧力による破壊が起こると考えられ好ましくなく、これらを満足する指標として水銀ポロシメーターで測定した細孔半径１０５Å以下の細孔の比表面積が５０〜１４０ｍ２／ｇである水和珪酸が望まれ、併せて印刷後不透明度向上のためのインキビヒクル吸収のための細孔積算容量が４．０ｃｃ／ｇ以上であることが重要である。４．０ｃｃ／ｇ未満の場合は、インクの吸収性が十分満足のいくものではないため、インクの吸収性の良好な紙用填料となり得ない。なお、本発明では、水銀ポロシメーター（形式：ポアサイザー９３２０、マイクロメリティックス社製）を用いて細孔直径とそれに対応する細孔容量を測定する。細孔直径が１０５Å以下の細孔容量は、細孔直径が１２Å〜１０５Åの積算容量である。 Furthermore, if the specific surface area at the primary particle level of this hydrated silicic acid is too small, the bonding force between the particles will be reduced, and if the specific surface area is too large, the primary particle diameter will be small and the destruction due to the pressure of the secondary particles. As an index that satisfies these, hydrated silicic acid having a specific surface area of pores having a pore radius of 10 5 Å or less measured with a mercury porosimeter as 50 to 140 m 2 / g is desired. It is important that the accumulated pore capacity for absorbing the ink vehicle for improving opacity after printing is 4.0 cc / g or more. If it is less than 4.0 cc / g, the ink absorbency is not sufficiently satisfactory, and it cannot be a paper filler having a good ink absorbability. In the present invention, the pore diameter and the corresponding pore volume are measured using a mercury porosimeter (type: pore sizer 9320, manufactured by Micromeritics). Pore volume of pore diameter of 10 5 Å or less, the pore diameter of the accumulated capacity of 12Å~10 5 Å.
＜水和珪酸の製造方法＞
つぎに、水和珪酸の製造方法について説明する。本発明で用いられるケイ酸アルカリ水溶液は、特に限定されないが、ケイ酸ナトリウム水溶液又はケイ酸カリウム水溶液が好適である。ケイ酸アルカリ水溶液のモル濃度は、ケイ酸ナトリウムの場合、モル比（ＳｉＯ２／Ｎａ２Ｏ）が２．０〜３．４の範囲から選ぶのが好適である。このケイ酸アルカリ水溶液にはアルカリ性難溶の粒子を含むことはなんら差し支えない。具体的には、炭酸カルシウム、水酸化マグネシウム、酸化マグネシウム、炭酸マグネシウム、炭酸ニッケル、炭酸バリウム、水酸化カルシウム、水酸化マンガン、マグネシウム、マンガン、マンガン酸カリウム、鉄、ニッケル、酸化亜鉛、酸化カルシウム、酸化マンガン等が挙げられる。
<Method for producing hydrated silicic acid>
Next, a method for producing hydrated silicic acid will be described. The alkali silicate aqueous solution used in the present invention is not particularly limited, but a sodium silicate aqueous solution or a potassium silicate aqueous solution is preferable. In the case of sodium silicate, the molar concentration of the aqueous alkali silicate solution is preferably selected from the range where the molar ratio (SiO 2 / Na 2 O) is 2.0 to 3.4. This alkaline silicate aqueous solution may contain particles that are hardly soluble in alkali. Specifically, calcium carbonate, magnesium hydroxide, magnesium oxide, magnesium carbonate, nickel carbonate, barium carbonate, calcium hydroxide, manganese hydroxide, magnesium, manganese, potassium manganate, iron, nickel, zinc oxide, calcium oxide, Manganese oxide etc. are mentioned.
これらの水和珪酸は、ケイ酸アルカリ水溶液に鉱酸を添加して中和する操作において、ケイ酸アルカリの中和に必要な鉱酸の量の２０〜５０％を第一の鉱酸として２０〜６０℃で最初に添加し、次いで７０℃以上に昇温した後必要に応じて熟成時間を設け、中和に必要な残りの鉱酸（第二の鉱酸）を添加することが必要となる。中和用の鉱酸の添加は、十分な時間をかけて行うことが望ましい。それは局部的に大きなｐＨの変化をきたさないことが目的である。しかし実際の場においては製造効率の概念が重要となるため、３００分以内には中和反応を終了できるよう工夫することが望ましい。本発明で水和珪酸を析出させる時に用いられる鉱酸としては公知のものが何等制限なく使用でき、これらを単独、 又は二種以上を併用して使用しても良い。具体的には、鉱酸として塩酸、硫酸、 硝酸等があげられるが、硫酸が入手容易で、比較的安価であるために好適に用いられる。鉱酸の濃度は、特に制限されないが一般には１０〜３０重量％の範囲から選べばよい。また、鉱酸をすべて添加した後の生成物を含むスラリーのｐＨは２〜６．５、好ましくは４〜６の範囲に調整する。 These hydrated silicic acids are prepared by adding 20-50% of the amount of mineral acid required for neutralizing the alkali silicate in the operation of neutralizing the alkali silicate aqueous solution by adding a mineral acid. It is necessary to first add at ˜60 ° C., then raise the temperature to 70 ° C. or higher and then provide aging time if necessary, and add the remaining mineral acid (second mineral acid) necessary for neutralization Become. It is desirable to add the neutralizing mineral acid over a sufficient time. It is intended not to cause a large pH change locally. However, since the concept of production efficiency is important in actual situations, it is desirable to devise so that the neutralization reaction can be completed within 300 minutes. As the mineral acid used when the hydrated silicic acid is precipitated in the present invention, known ones can be used without any limitation, and these may be used alone or in combination of two or more. Specific examples of the mineral acid include hydrochloric acid, sulfuric acid, nitric acid and the like, and sulfuric acid is easily used and is preferably used because it is relatively inexpensive. The concentration of the mineral acid is not particularly limited, but generally may be selected from the range of 10 to 30% by weight. Moreover, the pH of the slurry containing the product after all the mineral acid has been added is adjusted to a range of 2 to 6.5, preferably 4 to 6.
第一の鉱酸の添加開始時から、第二の鉱酸の添加開始時までに水和珪酸１ｋｇあたり１５０〜３００ｋＪの攪拌負荷を付与することにより、上記物性で特徴付けられる水和珪酸を収率良く得ることができる。攪拌に用いる機器としては、通常用いるミキサーに攪拌翼としてプロペラ、タービン、パドル、アンカー、リボンなど各形式のものを単独で、あるいは適宜組み合わせて使用することが可能であり、これは合成の条件により上記攪拌負荷を達成するように選択すればよい。また、ホモミキサーや各種ミルなども組み合わせることが可能である。もちろん撹拌槽内には乱流を起こすために邪魔板を設けたり、また反応液を一部取り出しインラインミキサーのようなもので負荷を加え、槽に還流するといったこともなんら差し支えない。回転速度としても翼径や反応条件によるが、通常翼周速度として１００〜６００ｍ／ｍｉｎの範囲であることが好ましい。 By applying a stirring load of 150 to 300 kJ per kg of hydrated silicic acid from the start of the addition of the first mineral acid to the start of the addition of the second mineral acid, the hydrated silicic acid characterized by the above physical properties is collected. It can be obtained efficiently. As the equipment used for stirring, it is possible to use a mixer used in the usual manner, such as a propeller, a turbine, a paddle, an anchor, and a ribbon as a stirring blade alone or in appropriate combination, depending on the conditions of synthesis. What is necessary is just to select so that the said stirring load may be achieved. A homomixer or various mills can also be combined. Of course, a baffle plate may be provided in the agitation tank to cause turbulent flow, or a part of the reaction solution may be taken out and applied with a load such as an in-line mixer to return to the tank. Although the rotational speed also depends on the blade diameter and reaction conditions, the blade peripheral speed is preferably in the range of 100 to 600 m / min.
この工程においては、ケイ酸アルカリ水溶液中のケイ酸分が二次粒子として析出する反応がもっとも活発に行われるため、反応系の均一性を高めることが一次粒子及び二次粒子の性状を均一化する結果となる。ケイ酸１ｋｇあたり１５０ｋＪの攪拌負荷を与えることはその均一性を達成するために必要な操作となる。さらには３００ｋＪを超える攪拌負荷を与えてしまうと、形成された二次粒子が破壊されてしまい、最終生成物の粒子径が例えば１５μｍを下回ってしまうような歩留まりの悪い水和珪酸となってしまう。さらには、粒子径（μｍ）を対数で表示したときの粒子径に対する粒子体積の分布の標準偏差を０．３〜０．４の範囲に限定するという本発明の効果からも外れてしまうことがあるため、好ましくない。 In this process, the reaction in which the silicic acid content in the aqueous alkali silicate solution precipitates as the secondary particles is the most active, so improving the uniformity of the reaction system makes the properties of the primary and secondary particles uniform. Result. Giving a stirring load of 150 kJ per kg of silicic acid is an operation necessary to achieve the uniformity. Furthermore, if an agitation load exceeding 300 kJ is applied, the formed secondary particles are destroyed, resulting in a hydrated silicic acid having a poor yield such that the particle size of the final product falls below, for example, 15 μm. . Furthermore, it may deviate from the effect of the present invention in which the standard deviation of the particle volume distribution with respect to the particle size when the particle size (μm) is expressed in logarithm is limited to a range of 0.3 to 0.4. This is not preferable.
＜水和珪酸のパルプへの添加＞
次に、本発明による水和珪酸は、パルプ原料に填料として添加した場合、抄紙して得られる紙に高い不透明度、特に印刷後不透明度を付与する。その理由は、粒子内部の空隙量が増加し吸油量が増加することで、紙に印刷されたインキの浸透を抑制する能力が増したためと考えられる。
本発明による水和珪酸系填料を抄紙の際にパルプ原料に添加して抄紙することによって、得られる紙に高い不透明度、特に印刷後不透明度が付与されるのは、粒子内部の１０５Å以下の細孔の細孔容量が増加することで吸油量が増加し、紙に印刷されたインキの浸透を抑制する能力が増したためと考えられる。
<Addition of hydrated silicic acid to pulp>
Next, when the hydrated silicic acid according to the present invention is added as a filler to a pulp raw material, it imparts high opacity, particularly opacity after printing, to paper obtained by papermaking. The reason is considered to be that the ability to suppress the penetration of ink printed on paper is increased by increasing the amount of voids inside the particles and increasing the amount of oil absorption.
By papermaking hydrated silicic filler according to the invention was added to the pulp material during the papermaking, high paper resulting opacity, especially the opacity after printing is applied, the internal particle 10 5 Å This is probably because the oil absorption increased as the pore volume of the following pores increased, and the ability to suppress permeation of ink printed on paper increased.
以下に実施例を挙げて本発明をより具体的に説明するが、本発明は勿論これらに限定されるものではない。なお、以下の実施例において、％は、全て重量％である。なお、本発明の水和珪酸の各特性値は、得られた粒子スラリーを濾過水洗した後、乾燥機にて１０５℃で乾燥し、この乾燥物を下記の測定方法により測定して得た。 Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the following examples, all percentages are by weight. In addition, each characteristic value of the hydrated silicic acid of the present invention was obtained by washing the obtained particle slurry with filtered water and then drying at 10 5 ° C with a dryer, and measuring this dried product by the following measuring method. .
細孔容量及び比表面積
水銀ポロシメーター（形式：ポアサイザ９３２０、マイクロメリティックス社製）を用いて測定した。なお、細孔直径１０５Å以下の細孔表面積、細孔容量については、細孔直径が１２Å〜１０５Åの細孔について測定した。
The pore volume and specific surface area were measured using a mercury porosimeter (type: pore sizer 9320, manufactured by Micromeritics). Incidentally, the pore diameter 10 5 Å or less of the pore surface area, for the pore volume, pore diameter was measured for the pores of 12Å~10 5 Å.
（２）粒度分布
レーザー回折式粒度分布測定装置 （形式：ＳＡＬＤ−２０００、島津製作所製）において、メディアン径を平均粒子径μとした。標準偏差σは、１００分割した粒子径Ｘｊ、および頻度分布 ｑｊとしたとき、下記の式で求める。
平均値 μ ＝１／１００Σ＜ｊ＝１，ｎ＞（ｑｊ（ｌｏｇＸｊ＋ｌｏｇＸｊ＋１）／２）
標準偏差 σ ＝ ｛（（１／１００Σ＜ｊ＝１，ｎ＞［（ｌｏｇＸｊ＋ｌｏｇＸｊ＋１）／２］）＾２）−μ＾２｝＾（１／２）
なお、上記の２つの式で、「ｌｏｇ」は常用対数を示す。また、＾２は二乗を示し、＾（１／２）は平方根を示す。
(2) Particle size distribution In a laser diffraction type particle size distribution measuring apparatus (form: SALD-2000, manufactured by Shimadzu Corporation), the median diameter was defined as an average particle diameter μ. The standard deviation σ is obtained by the following equation when the particle diameter X j divided by 100 and the frequency distribution q j are used.
Average value μ = 1 / 100Σ <j = 1, n> (q j (logX j + logX j + 1 ) / 2)
Standard deviation σ = {((1 / 100Σ <j = 1, n> [(logX j + logX j + 1 ) / 2]) ^ 2) −μ ^ 2} ^ (1/2)
In the above two formulas, “log” indicates a common logarithm. Also, ^ 2 indicates the square and ^ (1/2) indicates the square root.
（３）電力量測定
ＬＥＤ型マルチメータ （形式：ＲＭ−１１０、タケモトデンキ社製）を攪拌機に取り付け消費電力量を求め、仕事効率８０％として電力負荷とした。
(3) Measurement of electric energy An LED type multimeter (model: RM-110, manufactured by Takemoto Denki Co., Ltd.) was attached to a stirrer, and the electric power consumption was determined.
（４）粒径維持率
水和珪酸の１０％スラリー２Ｌを攪拌翼（タービン羽根、直径８０ｍｍ、アズワン社製）を１枚使用した攪拌機により１０００ｒｐｍで１２０分攪拌した時の平均粒子径を測定し、「処理後平均粒子径／処理前平均粒子径×１００（％）」をもって粒径維持率とした。
（５）吸油量
ＪＩＳ Ｋ５１０１の方法により、試料５ｇにＪＩＳ Ｋ５４２１規定の煮亜麻仁油をビュレットから滴下し、全体がパテ状の固まりになるまでに使用した煮亜麻仁油量を試料１００ｇあたりの量に換算する。
(4) Particle size maintenance ratio The average particle diameter when stirring 2 liters of 10% slurry of hydrated silicic acid at 1000 rpm for 120 minutes with a stirrer using one stirring blade (turbine blade, diameter 80 mm, manufactured by ASONE) was measured. , “Average particle diameter after treatment / average particle diameter before treatment × 100 (%)” was defined as the particle size maintenance ratio.
(5) Oil absorption amount According to the method of JIS K5101, boiled linseed oil defined in JIS K5421 is dripped from a burette to 5 g of the sample, and the amount of boiled linseed oil used until the whole becomes a putty-like mass is adjusted to the amount per 100 g of sample. Convert.
以上の（１）〜（５）の測定項目について、以下の実施例・比較例につき測定した結果は、全て表１、表２にまとめて記載した。 With respect to the measurement items (1) to (5) above, the results measured for the following examples and comparative examples are all shown in Tables 1 and 2.
＜実施例１＞ 市販のＪＩＳ３号ケイ酸ソーダ水溶液（トクヤマ製、固形分濃度３０％）２４０ｇを純水にて１０００ｇに希釈し、水和珪酸（二酸化ケイ素）濃度を７２ｇ／ｋｇとして２Ｌのステンレスビーカーに入れ、温度５０℃において無水硫酸ナトリウム１７．９ｇを添加した。スリーワンモーターで攪拌しながらケイ酸ソーダを中和するのに必要な全酸所要量の４０％に相当する硫酸（濃度２０％）７２ｇを１６分間かけて連続的に添加した。硫酸の添加が終わったあと、攪拌しながら２５分間で温度を９０℃まで昇温した。このままの温度でそのまま攪拌を続け、９分間熟成を行い、ここまでの電力量が最終生成物の単位重量あたり２００ｋＪ／ｋｇであることを確認した。ついで、全酸所要量の６０％に相当する硫酸１０８ｇを２０分間かけて連続的に添加し、更に２０分間熟成を行った。この時のスラリーのｐＨは５．２であった。
次いで、この反応生成物を含むスラリーをレーザー回折式粒度分布計（島津、ＳＡＬＤ−１１００）による測定したところ、平均粒子径２２μｍ、粒子径（μｍ）を対数で表示したときの粒子径に対する粒子体積の分布の標準偏差０．３５が得られた。このスラリーをブフナーロートにて濾過しケーキ状の水和珪酸を得、一部を１０５℃にて一晩乾燥し、ＪＩＳＫ５１０１の方法による吸油量及び水銀ポロシメーターにより比表面積、細孔容量を測定した。
<Example 1> 240 g of a commercially available JIS No. 3 sodium silicate aqueous solution (manufactured by Tokuyama, solid content concentration 30%) is diluted to 1000 g with pure water, and the hydrated silicic acid (silicon dioxide) concentration is 72 g / kg. In a beaker, 17.9 g of anhydrous sodium sulfate was added at a temperature of 50 ° C. While stirring with a three-one motor, 72 g of sulfuric acid (concentration 20%) corresponding to 40% of the total amount of acid required for neutralizing sodium silicate was continuously added over 16 minutes. After the addition of sulfuric acid was completed, the temperature was raised to 90 ° C. over 25 minutes with stirring. Stirring was continued as it was at this temperature, and aging was performed for 9 minutes, and it was confirmed that the amount of electric power so far was 200 kJ / kg per unit weight of the final product. Subsequently, 108 g of sulfuric acid corresponding to 60% of the total acid requirement was continuously added over 20 minutes, followed by aging for another 20 minutes. The pH of the slurry at this time was 5.2.
Subsequently, when the slurry containing this reaction product was measured by a laser diffraction particle size distribution analyzer (Shimadzu, SALD-1100), the average particle diameter was 22 μm, and the particle volume relative to the particle diameter when the particle diameter (μm) was displayed in logarithm. A standard deviation of 0.35 was obtained. This slurry was filtered through a Buchner funnel to obtain cake-like hydrated silicic acid. A part of the slurry was dried overnight at 105 ° C., and the specific surface area and pore volume were measured with an oil absorption amount and a mercury porosimeter according to the method of JISK5101.
＜実施例２＞ ケイ酸ソーダ水溶液２４０ｇを純水で水和珪酸濃度を７２ｇ／ｋｇとして２Ｌのステンレスビーカーに入れ、温度５０℃において無水硫酸ナトリウム１７．９ｇを添加した後に、第一の硫酸を４５ｇ（全酸所要量の２５％に相当）を１０分間で添加し、２５分間で温度を９０℃まで昇温した後、１５分間熟成を行い、ここまでの電力量が２００ｋＪ／ｋｇであることを確認した。ついで、第二の硫酸を１３５ｇ（全酸所要量の７５％に相当）として中和反応を行った以外は実施例１と同様に反応、処理を行い、得られた水和珪酸スラリーを実施例１と同様にして評価した。反応終了後の溶液のｐＨは５．０、得られた粒子の平均粒子径は１６μｍであった。 <Example 2> 240 g of sodium silicate aqueous solution was added to a 2 L stainless beaker with a hydrated silicic acid concentration of 72 g / kg with pure water, and after adding 17.9 g of anhydrous sodium sulfate at a temperature of 50 ° C., the first sulfuric acid was added. 45 g (corresponding to 25% of the total acid requirement) is added over 10 minutes, the temperature is raised to 90 ° C. over 25 minutes, and then aging is performed for 15 minutes. The amount of power up to this point is 200 kJ / kg. It was confirmed. Subsequently, the reaction and treatment were carried out in the same manner as in Example 1 except that the neutralization reaction was carried out with 135 g of second sulfuric acid (corresponding to 75% of the total acid requirement). Evaluation was performed in the same manner as in 1. The pH of the solution after completion of the reaction was 5.0, and the average particle size of the obtained particles was 16 μm.
＜実施例３＞ ケイ酸ソーダ水溶液２４０ｇを純水で水和珪酸濃度を７２ｇ／ｋｇとして２Ｌのステンレスビーカーに入れ、温度５０℃において無水硫酸ナトリウム１７．９ｇを添加した後に、第一の硫酸を４５ｇ（全酸所要量の２５％に相当）を１０分間で添加し、２５分間で温度を９０℃まで昇温した後、３分間熟成を行い、ここまでの電力量が１５０ｋＪ／ｋｇであることを確認した。ついで、第二の硫酸を１３５ｇ（全酸所要量の７５％に相当）として中和反応を行った以外は実施例１と同様に反応、処理を行い、得られた水和珪酸スラリーを実施例１と同様にして評価した。反応終了後の溶液のｐＨは５．０、得られた粒子の平均粒子径は１６μｍであった。 <Example 3> 240 g of sodium silicate aqueous solution was added to a 2 L stainless beaker with a hydrated silicic acid concentration of 72 g / kg with pure water, and after adding 17.9 g of anhydrous sodium sulfate at a temperature of 50 ° C., the first sulfuric acid was added. 45 g (corresponding to 25% of the total acid requirement) is added over 10 minutes, the temperature is raised to 90 ° C. over 25 minutes, then aging is performed for 3 minutes, and the power up to this point is 150 kJ / kg It was confirmed. Subsequently, the reaction and treatment were carried out in the same manner as in Example 1 except that the neutralization reaction was carried out with 135 g of second sulfuric acid (corresponding to 75% of the total acid requirement). Evaluation was performed in the same manner as in 1. The pH of the solution after completion of the reaction was 5.0, and the average particle size of the obtained particles was 16 μm.
＜実施例４＞ 第一の硫酸を８１ｇ（全酸所要量の４５％に相当）を１８分間で添加し、７分間熟成を行い、ここまでの電力量が２００ｋＪ／ｋｇであることを確認した。ついで、第二の硫酸を９９ｇ（全酸所要量の５５％に相当）として中和反応を行った以外は実施例１と同様に反応、処理を行い、得られた水和珪酸スラリーを実施例１と同様にして評価した。反応終了後の溶液のｐＨは５．２、得られた粒子の平均粒子径は２８μｍであった。 <Example 4> 81 g (corresponding to 45% of the total acid requirement) of the first sulfuric acid was added over 18 minutes, and aging was performed for 7 minutes. It was confirmed that the amount of power up to this point was 200 kJ / kg. . Subsequently, the reaction and treatment were carried out in the same manner as in Example 1 except that the neutralization reaction was carried out with 99 g of second sulfuric acid (corresponding to 55% of the total acid requirement), and the resulting hydrated silica slurry was treated as Example. Evaluation was performed in the same manner as in 1. The pH of the solution after completion of the reaction was 5.2, and the average particle diameter of the obtained particles was 28 μm.
＜実施例５＞ ケイ酸ソーダ水溶液２４０ｇを純水で水和珪酸濃度を７２ｇ／ｋｇとして２Ｌのステンレスビーカーに入れ、温度２５℃において無水硫酸ナトリウム１７．９ｇを添加した後に、第一の硫酸を添加し、第二の硫酸を７５℃において添加し中和反応を行った以外は実施例１と同様に反応、処理を行い、得られた水和珪酸スラリーを実施例１と同様にして評価した。反応終了後の溶液のｐＨは５．１、得られた粒子の平均粒子径は２９μｍであった。第二の硫酸添加開始前までの電力量は２００ｋＪ／ｋｇであった。 <Example 5> 240 g of sodium silicate aqueous solution was added to a 2 L stainless beaker with a hydrated silicic acid concentration of 72 g / kg with pure water, and 17.9 g of anhydrous sodium sulfate was added at a temperature of 25 ° C. And the second sulfuric acid was added at 75 ° C. to carry out the neutralization reaction, and the reaction and treatment were performed in the same manner as in Example 1. The resulting hydrated silicate slurry was evaluated in the same manner as in Example 1. . The pH of the solution after completion of the reaction was 5.1, and the average particle diameter of the obtained particles was 29 μm. The amount of electric power before the start of the second sulfuric acid addition was 200 kJ / kg.
＜実施例６＞ ケイ酸ソーダ水溶液２４０ｇを純水で水和珪酸濃度を７２ｇ／ｋｇとして２Ｌのステンレスビーカーに入れ、温度２５℃において無水硫酸ナトリウム１７．９ｇを添加した後に、第一の硫酸を添加し、９０℃に昇温後、３５分熟成を行ない、ここまでの電力が３００ｋＪ／ｋｇであることを確認した、ついで第二の硫酸を７５℃において添加し中和反応を行った以外は実施例１と同様に反応、処理を行い、得られた水和珪酸スラリーを実施例１と同様にして評価した。反応終了後の溶液のｐＨは５．１、得られた粒子の平均粒子径は１８μｍであった。 <Example 6> 240 g of sodium silicate aqueous solution was added to a 2 L stainless beaker with a hydrated silicic acid concentration of 72 g / kg with pure water, and 17.9 g of anhydrous sodium sulfate was added at a temperature of 25 ° C. After the addition, the temperature was raised to 90 ° C., aging was carried out for 35 minutes, and it was confirmed that the power up to this point was 300 kJ / kg, and then the second sulfuric acid was added at 75 ° C. to carry out the neutralization reaction. The reaction and treatment were performed in the same manner as in Example 1, and the obtained hydrated silicic acid slurry was evaluated in the same manner as in Example 1. The pH of the solution after completion of the reaction was 5.1, and the average particle size of the obtained particles was 18 μm.
＜実施例７＞ 温度５５℃において第一の硫酸を添加し、第二の硫酸を９５℃において添加し中和反応を行った以外は実施例１と同様に反応、処理を行い、得られた水和珪酸スラリーを実施例１と同様にして評価した。反応終了後の溶液のｐＨは５．１、得られた粒子の平均粒子径は２０μｍであった。第二の硫酸添加開始前までの電力量は２００ｋＪ／ｋｇであった。 <Example 7> The first sulfuric acid was added at a temperature of 55 ° C, and the second sulfuric acid was added at 95 ° C to carry out a neutralization reaction. The hydrated silicic acid slurry was evaluated in the same manner as in Example 1. The pH of the solution after completion of the reaction was 5.1, and the average particle diameter of the obtained particles was 20 μm. The amount of electric power before the start of the second sulfuric acid addition was 200 kJ / kg.
＜比較例１＞ 第一の硫酸を８分間かけて連続的に添加し、攪拌しながら１２分間で温度を９０℃まで昇温し、そのまま攪拌を続け、５分間熟成を行い、ここまでの電力量が１００ｋＪ／ｋｇであることを確認したこと以外は実施例１と同様に反応、処理を行い評価した。この時のスラリーのｐＨは５．２、得られた粒子の平均粒子径は３０μｍであった。 <Comparative Example 1> The first sulfuric acid was continuously added over 8 minutes, the temperature was raised to 90 ° C in 12 minutes while stirring, the stirring was continued as it was, and aging was performed for 5 minutes. The reaction and treatment were carried out in the same manner as in Example 1 except that it was confirmed that the amount was 100 kJ / kg. The pH of the slurry at this time was 5.2, and the average particle diameter of the obtained particles was 30 μm.
＜比較例２＞第一の硫酸を３０分間かけて連続的に添加し、攪拌しながら５０分間で温度を９０℃まで昇温し、そのまま攪拌を続け、１０分間熟成を行い、ここまでの電力量が３５０ｋＪ／ｋｇであることを確認したこと以外は実施例１と同様に反応、処理を行い評価した。この時のスラリーのｐＨは５．２、得られた粒子の平均粒子径は１４μｍであった。 <Comparative Example 2> First sulfuric acid was continuously added over 30 minutes, the temperature was raised to 90 ° C over 50 minutes while stirring, stirring was continued as it was, and aging was performed for 10 minutes. The reaction and treatment were carried out and evaluated in the same manner as in Example 1 except that the amount was confirmed to be 350 kJ / kg. The pH of the slurry at this time was 5.2, and the average particle diameter of the obtained particles was 14 μm.
＜比較例３＞５０℃において第一の硫酸を９９ｇ（全酸所要量の５５％に相当）添加しようとしたが、９５ｇ添加した後増粘し、正常な攪拌ができなくなったため中断した。 <Comparative Example 3> 99 g (corresponding to 55% of the total acid requirement) of the first sulfuric acid was added at 50 ° C., but after 95 g was added, the viscosity increased and normal stirring could not be performed.
＜比較例４＞温度１５℃において無水硫酸ナトリウム１７．９ｇを添加した後に、第一の硫酸を添加し、第二の硫酸を６５℃において添加し中和反応を行った以外は実施例１と同様に反応、処理を行い、得られた水和珪酸スラリーを実施例１と同様にして評価した。反応終了後の溶液のｐＨは５．１、得られた粒子の平均粒子径は３５μｍであった。 <Comparative Example 4> Example 1 except that 17.9 g of anhydrous sodium sulfate was added at a temperature of 15 ° C, then the first sulfuric acid was added, and the second sulfuric acid was added at 65 ° C to conduct a neutralization reaction. The reaction and treatment were conducted in the same manner, and the obtained hydrated silicic acid slurry was evaluated in the same manner as in Example 1. The pH of the solution after completion of the reaction was 5.1, and the average particle size of the obtained particles was 35 μm.
＜比較例５＞温度６５℃において無水硫酸ナトリウム１７．９ｇを添加した後に、第一の硫酸を添加し、第二の硫酸を９０℃において添加し中和反応を行った以外は実施例１と同様に反応、処理を行い、得られた水和珪酸スラリーを実施例１と同様にして評価した。反応終了後の溶液のｐＨは５．１、得られた粒子の平均粒子径は１７μｍであった。 <Comparative Example 5> Example 1 except that 17.9 g of anhydrous sodium sulfate was added at a temperature of 65 ° C, then the first sulfuric acid was added, and the second sulfuric acid was added at 90 ° C to conduct a neutralization reaction. The reaction and treatment were conducted in the same manner, and the obtained hydrated silicic acid slurry was evaluated in the same manner as in Example 1. The pH of the solution after completion of the reaction was 5.1, and the average particle size of the obtained particles was 17 μm.
＜比較例６＞ケイ酸ソーダ水溶液２４０ｇを純水にて１０００ｇに希釈し、水和珪酸（二酸化ケイ素）濃度を７２ｇ／ｋｇとして２Ｌのステンレスビーカーに入れ、温度５０℃において無水硫酸ナトリウム１７．９ｇおよび平均粒径０．７μｍの水酸化マグネシウム１０ｇを添加し、第二の硫酸を９０℃において１２０ｇ添加し中和反応を行った以外は実施例１と同様に反応、処理を行い、得られた水和珪酸スラリーを実施例１と同様にして評価した。反応終了後の溶液のｐＨは５．１、得られた粒子の平均粒子径は２０μｍであった。 <Comparative Example 6> 240 g of an aqueous sodium silicate solution was diluted to 1000 g with pure water, put into a 2 L stainless steel beaker with a hydrated silicic acid (silicon dioxide) concentration of 72 g / kg, and 17.9 g of anhydrous sodium sulfate at a temperature of 50 ° C. And 10 g of magnesium hydroxide having an average particle size of 0.7 μm was added and 120 g of second sulfuric acid was added at 90 ° C. to carry out the neutralization reaction, and the reaction and treatment were performed in the same manner as in Example 1 to obtain. The hydrated silicic acid slurry was evaluated in the same manner as in Example 1. The pH of the solution after completion of the reaction was 5.1, and the average particle diameter of the obtained particles was 20 μm.
表１、表２から明らかな如く、本発明の製造方法によって得られる水和珪酸は、吸油量が高く、粒径維持率も優れている。これに対し、比較例で示されたすべての水準においては、吸油量３６０ｍｌ／１００ｇ以上および粒径維持率９５％以上を同時に満足するものは存在しない。
As is apparent from Tables 1 and 2, the hydrated silicic acid obtained by the production method of the present invention has a high oil absorption and an excellent particle size retention rate. On the other hand, in all the levels shown in the comparative examples, there is nothing that satisfies the oil absorption amount of 360 ml / 100 g or more and the particle size maintenance rate of 95% or more at the same time.
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| DE2803917A1 (en) * | 1978-01-30 | 1979-08-02 | Degussa | FELLING SILICA GRANULATES |
| JP2666638B2 (en) * | 1991-12-27 | 1997-10-22 | 王子製紙株式会社 | Method for producing hydrated silicic acid for papermaking |
| JP2908253B2 (en) * | 1994-09-26 | 1999-06-21 | 日本化学工業株式会社 | Hydrated silica and its production method |
| JP3982027B2 (en) * | 1997-10-06 | 2007-09-26 | 王子製紙株式会社 | Method for producing composite particles |
| JP4568921B2 (en) * | 1998-03-12 | 2010-10-27 | 王子製紙株式会社 | Silica particles, method for producing the same, and silica particle-containing paper |
| JP4030403B2 (en) * | 2002-09-27 | 2008-01-09 | 株式会社トクヤマ | Method for dispersing dry silica |
| JP2005053728A (en) * | 2003-08-01 | 2005-03-03 | Dsl Japan Co Ltd | Amorphous silica particle having high oil absorption and high structural performance |
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2005
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