JP4175726B2 - Pet toilet sand - Google Patents

Description

式中、Ｌhkl は結晶の（ｈｋｌ）面に垂直な方向の寸法、Ｋは約０．９の定数、Ｈは回折ピークの半価幅（ラジアン）、λ及びθは前記式（２）と同一である、
で表される関係がある。
【００２１】
本発明のペット用トイレ砂（ベントナイト粒状成形品）では、Ｃ軸方向の積み重ねから成る結晶子サイズ前述した小さい範囲に抑制されており、これは粒状物内部での細孔容積の増大にも、水分吸収速度の増大、膨潤速度の増大ゲル加速度の増大にも役立っているものと信じられる。
【００２２】
本発明に用いるベントナイトは、前述した金属成分モル比（ＡＳ）を有するが、酸化物基準のモル比で表して、
Ａｌ_２Ｏ_３／ＳｉＯ_２＝０．０９５乃至０．１６
Ｎａ_２Ｏ／ＳｉＯ_２＝０．８×１０^−２乃至４．５×１０^−２
ＭＯ／ＳｉＯ_２＝４．５×１０^−２乃至１０．５×１０^−２
式中、Ｍはアルカリ土類金属を表す、
で表される化学組成を有するものであることが、前述した諸特性のバランスの点で好ましい。
【００２３】
本発明に用いるベントナイト粒状成形品は、最小方向における粒径が０．５乃至８ｍｍであり、アスペクト比が１乃至２０の範囲にあることが好ましい。この範囲の粒度特性を有するベントナイト粒状物では、その分散状態にランダム性があり、また水に接触したときの凝結の程度も堅く、使用済み部分を、崩壊することなく、塊として取り除くことが容易である。
【００２４】
上述した水の吸収、膨潤及び凝固乃至固化作用は、ペットなどの尿及び糞の吸収、膨潤及び凝固乃至固化並びに脱臭にも同様に作用するものであり、更に各種の水性汚物の処理にも同様に役立つものである。
【００２５】
［ベントナイト及びその製造］
本発明に用いるベントナイトは、前述した要件を満足するものであれば、天然産のベントナイトでも、或いは半合成のベントナイト（いわゆる活性ベントナイト）の何れであってもよいが、入手の容易さから、活性ベントナイトであることが好ましい。
【００２６】
好適なベントナイトは、以下に述べるように化学組成が一定の範囲にある酸性白土の含水物に、無水物換算で１乃至５重量％の固体炭酸ナトリウムを添加し、固体の添加混合物を、水分の保持条件下、４０℃以上の温度で混練し、該混合物中の酸性白土を活性ベントナイトに転化させ、生成物を造粒することにより製造される。
【００２７】
原料として用いる酸性白土は、モンモリロナイトを主成分とするものであるが、それ以外に、石英、長石、α−クリストバライト等の不純物を含有している。モンモリロナイトの基本的層構成は、ベントナイトに関して述べたのと同様であるが、酸性白土では、基本三層構造中の AlO_６八面体層中のAl原子の一部が、マグネシウムやカルシウム等のアルカリ土類金属で置換され、その原子価を補うように水素イオンが結合されていることが化学構造上の特徴である。
この化学構造上の特徴により、酸性白土は食塩水中に懸濁させ、そのpHを測定すると、前記水素イオンがＮaイオンで置換されるため酸性を示す。
【００２８】
本発明のベントナイトを製造するためには、上記酸性白土として、アルカリ土類金属成分の含有量が多く、アルカリ金属成分の含有量、特にナトリウム成分の含有量の少ないものを選択する。
一層具体的には、活性ベントナイト製造用の酸性白土としては、アルカリ金属成分をＲとして、アルカリ土類金属成分をＭとして表して、酸化物モル基準で、モル組成が
Ｒ_２Ｏ／ＳｉＯ_２＝０．１×１０^−２乃至１．５×１０^−２
特にＮａ_２Ｏ／ＳｉＯ_２＝０．３×１０^−２乃至１．０×１０^−２
であり、且つ
Ｍ_２Ｏ／ＳｉＯ_２＝４．５×１０^−２乃至１０．５×１０^−２
である酸性白土を用いるのが好ましく、これにより従来のベントナイトに比して消臭性能が向上しており、しかも水の吸収速度が大であると共に、その吸収容量も大きく、その結果として水を残すことなく吸収することができ、しかも前述した凝固部分が可及的に小さな容積に留まるようにすることが可能なベントナイト系吸収及び吸着剤を製造することが可能となる。
【００２９】
本発明のペット用トイレ砂は、相対的に金属成分の含有量の高い活性ベントナイトを使用するものであり、にもかかわらず、アルカリ金属分、特にナトリウム分の少ない酸性白土原料を使用するというのは、一見矛盾した感じを与えるかもしれないが、これは、アルカリ金属分の含有量の少ない酸性白土では、炭酸ナトリウムとの反応により層間に導入されるナトリウム分の多いこと（層間の水素イオンの多いこと）を意味するものであり、このようにイオン交換で導入されるナトリウム分は、層間の距離の拡大や比表面積及び細孔容積の増大、これによる水膨潤性や食塩水吸収能力の増大につながっていると信じられる。
【００３０】
また、アルカリ土類金属分の含有量が多いことは、最終ベントナイトの金属成分の増大や、層間水素イオン濃度の増大の点でよい影響をもたらしていると信じられる。
【００３１】
一般に、酸性白土は産出する状態で水分を含有している。この含有水分は、炭酸ナトリウムの反応に必要な水性媒体となる。一般に原料粘土中の水分は、１０乃至３５重量％、特に１５乃至３３重量％の範囲内にあるのがよい。勿論原料粘土中の水分が上記範囲よりも多い場合には、乾燥を行ない、また上記範囲よりも少ない場合には水分を補給すればよい。
【００３２】
用いる原料粘土は、固体の状態で添加される炭酸ナトリウムと均一に混合されることも重要である。このためには、原料粘土を混合に先立って可及的に微細な状態としておくことが有利である。一般に、原料粘土は、粒径３０００μｍ以上のものが３０重量％以下、特に２０重量％以下となるように粉砕しておくことが望ましい。
【００３３】
用いる炭酸ナトリウムの量は、無水物基準で粘土当り０．２乃至５重量％、特に0.5 乃至3.5 重量％の範囲から選ぶのがよい。最適の炭酸ナトリウムの量は酸性白土の産地等によっても相違するが、上記の一定の原料粘土について層間に導入できるナトリウム分の量を求め、これに基づいて最適添加量を決定すればよい。
【００３４】
原料粘土と固体炭酸ナトリウムとを混合し、この混合物を５０℃以上の温度及び保水条件下に混練する。混練には、一軸又は二軸の押出型混練装置、ロール型混練装置、バンバリーミキサー、土練機等を用いることができ、必要により装置内を減圧に維持することができる。混練組成物を上記温度に維持するには、混練装置内での摩擦熱を利用することができるし、また外部からの加熱を利用してもよい。
混練反応時の温度は５０乃至１００℃、特に６０乃至１００℃の範囲が適当であり、また反応時間は 1.0乃至１００時間、特に 1.0乃至２０時間の範囲が適当である。
【００３５】
混練後の反応生成物を、それ自体公知の手段で造粒する。造粒には、圧縮成形法、打錠成形法、転動造粒法、噴霧造粒法、押出造粒法等のそれ自体公知の造粒法が使用されるが、混練物を直ちに押出造粒するのが好適である。
【００３６】
ベントナイト造粒物は、一般に最小方向における粒径が０．５乃至８ｍｍであり、アスペクト比が１乃至２０の範囲にあることが、吸収及び吸着剤の取り扱いや、水分吸収の際の固結性や、凝固物の取り除き性の点で好ましい。粒子形状は、球状、立方体状、円柱状、角柱状、顆粒状、タブレット状、不定形状等の任意の形状であってよい。
【００３７】
得られた造粒物は、必要により乾燥して製品とする。乾燥温度は、１００乃至３００℃が適当である。
尚、反応は、一段で行うこともできるし、多段で行うこともできる。一般に必要でないが、例えば、一段目で混練下に反応を行わせ、この混練造粒物を密閉容器内或いはムロ内で或いは乾燥機内で上記温度で熟成反応を行わせてもよい。
反応を完結させるに当り、完結時の活性ベントナイト中の含水率が８重量％以下、好ましくは６重量％以下、乾燥温度、乾燥時間等の乾燥条件を任意に選ぶことが出来る。
【００３８】
【実施例】
本発明を以下の実施例で説明する。
以下の実施例における、測定は下記の方法で行った。
【００３９】
（１）細孔容積測定方法
マイクロメリテックス社製ＡＵＴＯＰＯＲＥ II ９２２０により測定した。
【００４０】
（２）ＢＥＴ表面積測定方法
カルロエルバ社製ＳＯＲＰＴＯＭＡＴＩＣ １９００により測定した。
【００４１】
（３）吸収容量測定方法
１００ｍｌのメスシリンダーに１００ｍｌの市販生理食塩水を取り、それに試料２ｇを加え、２４時間後の膨潤容積を測定した。
【００４２】
（４）吸収速度測定方法
５０ｍｌの蓋付きガラス瓶に８ｍｌの市販生理食塩水をとり、それに試料２ｇを加え、室温で静置し、試料の膨潤により瓶の内容物の流動性がなくなる時間を測定した。
【００４３】
（５）結晶子サイズ（単位：オングストローム）測定方法
結晶子サイズ測定時のＸ線回折条件
理学電気（株）製ガイガーフレックスＲＡＤ−１Ｂシステムを用いて、
Ｃｕ−Ｋαにて測定した。
ターゲット Ｃｕ
フィルター Ｎｉ
管電圧 ４０ｋＶ
管電流 ２０ｍＡ
カウントフルスケール ４ｋｃｐｓ
走査速度 ０．２５ｄｅｇ／ｍｉｎ
時定数 ０．５ｓｅｃ
スリット ＤＳ（ＳＳ） ０．５ｄｅｇ ＲＳ ０．１５ｍｍ
【００４４】
（６）アスペクト比測定方法
一試料につき１０個のアスペクト比を測定し、最大値と最小値を除いた平均値よりアスペクト比を算出した。
【００４５】
（７）化学組成
ＪＩＳ Ｍ−８８５２ ケイ石分析法に準拠して測定し、必要によっては原子吸光法を用いて測定した。
【００４６】
（８）アンモニア消臭性能測定方法
試料１００ｇを１．８リットルのガラス瓶に取り、ゴム製注入口のついた 蓋で密栓する。それに１％アンモニア水１ｍｌを滴下した。２０分後の残存ガス濃度をガス検知管で測定し、次式により消臭率を計算した。
試料を入れないで同様の操作を行いブランクガス濃度を測定する。
消臭率％＝１００−｛残存ガス濃度（ｐｐｍ）／ブランクガス濃度（ｐｐｍ）
×１００｝
【００４７】
（９）エチルメルカプタン消臭性能測定方法
試料１００ｇを１．８リットルのガラス瓶に取り、ゴム製注入口のついた蓋で密栓する。それにエチルメルカプタン０．００８ｗ／ｖ％エタノール 溶液１ｍｌを滴下した。５分後の残存ガス濃度をガス検知管で測定し、次式により消臭率を計算した。
試料を入れないで同様の操作を行いブランクガス濃度を測定する。
消臭率％＝１００−｛残存ガス濃度（ｐｐｍ）／ブランクガス濃度（ｐｐｍ）×１００｝
【００４８】
（１０）固化試験方法
300mlのトールビーカーに深さ６cmになるように試料を入れる。上方よりペットの尿の代替である1%食塩水7mlを10秒間で滴下し、試料を固化させ固化状態を評価する。
評価基準を下記に示す。
○：手指により圧力を加えても容易には崩れない。
△：手指により圧力を加えると崩れる。
×：固化しない。
【００４９】
（実施例１）
新潟県新発田市小戸産酸性白土（水分３３％）１００重量部と無水炭酸ナトリウム（試薬１級）２重量部を押し出し造粒機にて混合し、ポリエチレンフィルムの袋に入れ室温で２４時間放置する。それを直径３ｍｍの造粒板とカッテング装置を装着した押し出し造粒機にて円柱状に成形する。成型品を１５０℃にて１０時間乾燥し、ベントナイト成形体を得た。表１に造粒条件と得られた成形体の物性を示す。
【００５０】
（実施例２）
新潟県新発田市小戸産酸性白土（水分３３％）１００重量部と無水炭酸ナトリウム（試薬１級）３．３重量部を押し出し造粒機にて混合し、ポリエチレンフィルムの袋に入れ室温で２４時間放置する。それを直径３ｍｍの造粒板とカッテング装置を装着した押し出し造粒機にて円柱状に成形する。成型品を１５０℃にて１０時間乾燥し、ベントナイト成形体を得た。表１に造粒条件と得られた成形体の物性を示す。
【００５１】
（実施例３）
新潟県新発田市小戸産酸性白土（水分３３％）１００重量部と無水炭酸ナトリウム（試薬１級）０．７重量部を押し出し造粒機にて混合し、ポリエチレンフィルムの袋に入れ室温で２４時間放置する。それを直径３ｍｍの造粒板とカッテング装置を装着した押し出し造粒機にて円柱状に成形する。成型品を１５０℃にて１０時間乾燥し、ベントナイト成形体を得た。表１に造粒条件と得られた成形体の物性を示す。
【００５２】
（実施例４）
新潟県新発田市小戸産酸性白土（水分３３％）１００重量部と無水炭酸ナトリウム（試薬１級）２重量部を押し出し造粒機にて混合し、ポリエチレンフィルムの袋に入れ室温で２４時間放置する。それを直径１．５ｍｍの造粒板とカッテング装置を装着した押し出し造粒機にて円柱状に成形する。成型品を１５０℃にて１０時間乾燥し、ベントナイト成形体を得た。表１に造粒条件と得られた成形体の物性を示す。
【００５３】
（比較例１）
新潟県新発田市小戸産酸性白土（水分３３％）を直径３ｍｍの造粒板とカッテング装置を装着した押し出し造粒機にて円柱状に成形する。成型品を１５０℃にて１０時間乾燥し、成形体を得た。表１に造粒条件と得られた成形体の物性を示す。
【００５４】
（比較例２）
米国産ベントナイト粉末１００重量部と水５０部をよく混合し、それを直径３ｍｍの造粒板とカッテング装置を装着した押し出し造粒機にて円柱状に成形する。成型品を１５０℃にて１０時間乾燥しベントナイト成形体を得た。表１に造粒条件と得られた成形体の物性を示す。
【００５５】
（比較例３）
市販精製ベントナイト粉末１００重量部と水６０部をよく混合し、それを直径３ｍｍの造粒板とカッテング装置を装着した押し出し造粒機にて円柱状に成形する。成型品を１５０℃にて１０時間乾燥しベントナイト成形体を得た。表１に造粒条件と得られた成形体の物性を示す。
【００５６】
（比較例４）
新潟県朝日村産ベントナイト（水分３３％）を直径３ｍｍの造粒板とカッテング装置を装着した押し出し造粒機にて円柱状に成形する。成型品を１５０℃にて１０時間乾燥しベントナイト成形体を得た。表１に造粒条件と得られた成形体の物性を示す。
【００５７】
【表１】

【００５８】
【発明の効果】
本発明によれば、金属成分モル比（ＡＳ）が特定の範囲にあり、しかも比表面積及び細孔容積が大きい活性ベントナイト粒状成形品を、ベントナイト系吸収及び吸着剤として用いることにより、従来のベントナイトに比して消臭性能が向上しており、しかも水の吸収速度が大であると共に、その吸収容量も大きく、その結果として水を残すことなく吸収することができ、しかも前述した凝固部分が可及的に小さな容積に留まるようにすることが可能であり、例えば、ペット用トイレ砂などの用途に有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to pet litter that is excellent in water absorption, solidification, deodorization, and the like.
[0002]
[Prior art]
Pet pet litter has been used for a long time to handle urine discharged from pets such as cats. Various types of pet litter are used, such as natural zeolite, river sand, silica gel, newspaper, and paper sludge molding.
[0003]
It has been known for a long time to use bentonite for pet litter. For example, JP-A-1-269440 describes pet litter using a combination of a swellable clay mineral (smectite) and a deodorant. ing.
Japanese Patent No. 2572208 describes an excretion box containing an absorbent composition comprising an injection molded product of smectite clay (containing sodium bentonite) containing a water-soluble adhesive substance. A sleeper box is described that uses compressible and unfired water-swellable sodium bentonite as an absorbent composition.
[0004]
[Problems to be solved by the invention]
Many of the conventional pet litter sand is a simple filter agent such as sand or has a weak deodorizing function. Even if it has water absorption, it is difficult to separate the adsorbed portion and the non-adsorbed portion of urine, and it has been necessary to replace most or all of the pet toilet sand after absorbing urine.
[0005]
On the other hand, swellable clay minerals such as bentonite have the function of swelling and agglomerating the part to which urine adheres, so that only the dirty part can be solidified and this part can be easily removed It has the advantage of becoming.
[0006]
However, the known bentonite is still insufficient in deodorizing performance as pet litter, and it is necessary to use it in combination with a deodorant to compensate for this (see, for example, JP-A-1-269440) ), Further improvement in deodorizing performance is required.
Furthermore, from the standpoint of saving the amount used, the absorption rate of water is large and the absorption capacity is also large. As a result, it can be absorbed without leaving water, and the above-mentioned coagulation part is possible. Therefore, it is desired to stay in a small volume.
[0007]
Therefore, the object of the present invention is to improve the deodorizing performance as compared with the conventional pet litter made of bentonite , and also has a high water absorption rate and a large absorption capacity. It is an object of the present invention to provide pet litter that can be absorbed without leaving water and that allows the aforementioned solidified portion to remain in a volume as small as possible.
[0008]
[Means for Solving the Problems]
According to the present invention, pet toilet sand composed of a granular molded product mainly composed of bentonite,
The bentonite has the following formula (1):
AS = Ax / Six (1)
In the formula, Ax represents the total molar amount of each metal component of Na, K, Mg, Ca and Fe contained in bentonite, and Six represents the unit of silica (Si) component contained in bentonite. Represents the molar amount per weight,
The metal component molar ratio (AS) defined by is 0.10 or more , and in X-ray diffraction, the crystallite size determined from the half width of the diffraction peak of the plane index (001) is 150 angstroms or less, and , Expressed as a molar ratio based on oxide,
Al ₂ O ₃ / SiO ₂ = 0.095 to 0.16
Na ₂ O / SiO ₂ = 0.8 × 10 ^{−2 to} 4.5 × 10 ⁻²
MO / SiO ₂ = 4.5 × 10 ^{−2 to} 10.5 × 10 ⁻²
Where M represents an alkaline earth metal;
And having a chemical composition represented by
The granular molded article has a pore volume of 0.15 ml / g or more and a BET specific surface area of 70 m ² / g or more as measured by mercury porosimetry, and 20 ml as measured at room temperature using physiological saline. A pet toilet sand characterized by having an absorption capacity of 2 g or more and an absorption rate of 30 sec / ml / g or less.
In the pet litter of the present invention, the granular molded product preferably has a particle size in the minimum direction of 0.5 to 8 mm and an aspect ratio in the range of 1 to 20 .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
[Action]
The bentonite used in the present invention has the following formula (1)
AS = Ax / Six (1)
In the formula, Ax represents the total molar amount of each metal component of Na, K, Mg, Ca and Fe contained in bentonite, and Six represents the unit of silica (Si) component contained in bentonite. Represents the molar amount per weight,
One of the features is that the metal component molar ratio (AS) defined by the above is 0.10 or more, and has a BET specific surface area of 70 m ² / g or more, and various gas components, particularly odorous components Excellent adsorbability.
[0010]
As shown in the examples described later, the bentonite used in the present invention has a metal component molar ratio (AS) smaller than 0.10 or bentonite having a BET specific surface area smaller than 70 m ² / g. It is particularly excellent in odor component adsorption performance, that is, deodorization performance of ammonium content, amine component, hydrogen sulfide, and mercapto.
[0011]
Bentonite is mainly composed of montmorillonite, montmorillonite, three-layer structure consisting of SiO ₄ tetrahedral layers -AlO ₆ octahedral layer -SiO ₄ tetrahedra layer, or these tetrahedral phase, octahedral phase heterogeneous The basic structure is a three-layer structure substituted with the same type of metal, and water and cations are present between these laminated layers.
[0012]
On the other hand, the deodorizing action for odorous components is broadly classified into a physical adsorption action and a chemical adsorption action. The physical adsorption action works effectively on components present in a dilute state in the atmosphere, but there exists an adsorption equilibrium state, and the adsorbed components reach an equilibrium where they enter and exit the adsorbent. On the other hand, chemical adsorption does not have a force to attract components that are present in the distance, but has a feature that once contacted components are reliably captured and the captured components are not released.
[0013]
Since the bentonite used in the present invention has a large specific surface area among bentonites, it has excellent performance of adsorbing odorous components in the adsorbent. This provides significant advantages not only for physical adsorption but also for chemical adsorption. This is because the adsorbed component can be brought into contact with the chemical adsorption site in a concentrated form.
[0014]
Bentonite used in the present invention cannot be denied that the deodorizing effect due to physical adsorption is large, but it is recognized that the deodorizing effect due to chemical adsorption is also large. As already pointed out, metal cations exist between the layers of montmorillonite, and the tetrahedral and octahedral layers also contain metal components other than aluminum in the form of isomorphous substitution. The components are useful for chemisorption of hydrogen sulfide and mercaptans. Of course, it is believed that these cationic components are also useful for deodorizing malodorous components derived from organic acids. Moreover, in montmorillonite, especially montmorillonite derived from acidic clay, protons (hydrogen ions) exist between the layers, and this proton seems to be useful for chemical adsorption of ammonia and amines.
[0015]
The granular molded article mainly composed of bentonite used in the present invention has a pore volume of 0.15 ml / g or more, particularly 0.2 to 0.35 ml / g, as measured by mercury porosimetry, and water is rapidly absorbed. In order to absorb water and quickly swell and solidify, to quickly deodorize, and to absorb quickly without leaving water, so that the solidified part of water is kept as small as possible It is important. As shown in the example described later, in the bentonite granular molded product (pet toilet sand) whose pore volume is below the above range, it lacks the ability to absorb water inside the granular material at the initial stage of contact with water, Finally, the volume of the solidified portion per unit weight tends to be larger than that of the pet litter of the present invention.
[0016]
It has already been pointed out that bentonite has a layered structure, but when water is mixed with bentonite, water enters and swells between the basic layers (plate-like bodies) of the layer structure of smectite. The layers are dispersed in discrete colloidal forms and become fluidized. If this is left as it is, a card house structure is formed by suction repulsion between the basic layers, and is highly thickened or gelled. This is the principle of water absorption and solidification by bentonite.
[0017]
In the pet litter according to the present invention, bentonite is formed into a granule and has the above-mentioned voids therein, and water absorption, swelling and solidification proceed in a relatively short time of about 1 minute. The outer shape of the granular material is maintained in its original shape with almost no collapse, and the above process proceeds to solidify the granular material, and only the wetted portion can be solidified and removed.
[0018]
The pet litter for pets of the present invention is measured at room temperature using the method and physiological saline shown in the examples described later, and has an absorption capacity of 20 ml / 2g or more, particularly 25 to 40 ml / 2g, and 30 sec / ml / g. In particular, the absorption rate is 20 to 5 sec / ml / g or less. This naturally combines absorption and adsorption performance, but at the same time helps to improve deodorization performance and save usage.
[0019]
The bentonite used in pet litter of the present invention provides an X-ray diffraction, the crystallite size determined from the half width of the diffraction peak of the plane index (001) is 150 angstroms or less, in the range of particularly 140 to 50 Å .
[0020]
In X-ray diffraction of crystals, the following Bragg equation (2)
nλ = 2dhkl Sinθ (2)
Where n is the order, λ is the X-ray wavelength, dhkl is the (hkl) spacing of the crystal, and θ is the diffraction angle.
Is satisfied, it is known that an intensity peak appears in diffraction. The Scherrer equation (3) below is also present between the sharpness of the diffraction peak and the crystal size.

In the formula, Lhkl is a dimension in the direction perpendicular to the (hkl) plane of the crystal, K is a constant of about 0.9, H is the half-value width (radian) of the diffraction peak, and λ and θ are the same as the formula (2). Is,
There is a relationship represented by
[0021]
In the pet litter (bentonite granular molded product) of the present invention, the crystallite size consisting of stacking in the C-axis direction is suppressed to the above-mentioned small range, and this also increases the pore volume inside the granular material. It is believed that the moisture absorption rate is increased, the swelling rate is increased, and the gel acceleration is also increased.
[0022]
The bentonite used in the present invention has the above-mentioned metal component molar ratio (AS), but is expressed in terms of an oxide-based molar ratio.
Al ₂ O ₃ / SiO ₂ = 0.095 to 0.16
Na ₂ O / SiO ₂ = 0.8 × 10 ^{−2 to} 4.5 × 10 ⁻²
MO / SiO ₂ = 4.5 × 10 ^{−2 to} 10.5 × 10 ⁻²
Where M represents an alkaline earth metal;
It is preferable that it has a chemical composition represented by the above-mentioned balance of various properties.
[0023]
The bentonite granular molded product used in the present invention preferably has a particle size in the minimum direction of 0.5 to 8 mm and an aspect ratio in the range of 1 to 20. Bentonite granules having particle size characteristics in this range are random in their dispersed state and have a firm degree of condensation when contacted with water, making it easy to remove used parts as a lump without collapsing. It is.
[0024]
The above-described water absorption, swelling and coagulation / solidification action is similar to the absorption, swelling, coagulation / solidification and deodorization of urine and feces of pets and the like, and is also the same for the treatment of various aqueous filths. It is useful for.
[0025]
[Bentonite and its production]
The bentonite used in the present invention may be either natural bentonite or semi-synthetic bentonite (so-called active bentonite) as long as it satisfies the above-mentioned requirements. Bentonite is preferred.
[0026]
A suitable bentonite is obtained by adding 1 to 5% by weight of solid sodium carbonate in terms of anhydride to an aqueous solution of acidic clay having a chemical composition within a certain range as described below, and adding the solid additive mixture to the moisture content. It is produced by kneading at a temperature of 40 ° C. or higher under holding conditions, converting the acid clay in the mixture to activated bentonite, and granulating the product.
[0027]
The acidic clay used as a raw material is mainly composed of montmorillonite, but additionally contains impurities such as quartz, feldspar, α-cristobalite and the like. The basic layer structure of montmorillonite is the same as that described for bentonite, but in acid clay, some Al atoms in the AlO ₆ octahedron layer in the basic trilayer structure are made of alkaline earth such as magnesium and calcium. It is a chemical structural feature that it is substituted with a similar metal and a hydrogen ion is bonded so as to supplement its valence.
Due to the characteristics of this chemical structure, acidic clay is suspended in saline, and its pH is measured, so that the hydrogen ions are replaced with Na ions, indicating acidity.
[0028]
In order to produce the bentonite of the present invention, as the acid clay, one having a high content of an alkaline earth metal component and a low content of an alkali metal component, particularly a sodium component is selected.
More specifically, the acidic white clay for producing active bentonite is represented by R as the alkali metal component and M as the alkaline earth metal component, and the molar composition is R ₂ O / SiO ₂ = on the oxide molar basis. 0.1 × 10 ^{−2 to} 1.5 × 10 ⁻²
In particular, Na ₂ O / SiO ₂ = 0.3 × 10 ^{−2 to} 1.0 × 10 ⁻²
And M ₂ O / SiO ₂ = 4.5 × 10 ^{−2 to} 10.5 × 10 ⁻²
It is preferable to use acid clay, which has improved deodorization performance compared to conventional bentonite, and has a high water absorption rate and a large absorption capacity. It is possible to produce a bentonite-based absorption and adsorbent that can be absorbed without leaving, and that allows the above-mentioned solidified portion to remain as small as possible.
[0029]
The pet litter of the present invention uses active bentonite having a relatively high content of metal components, and nevertheless, it uses an acidic white clay raw material with low alkali metal content, particularly sodium content. May give a seemingly contradictory feeling, but in acidic clay with a low content of alkali metals, this is due to the fact that there is a large amount of sodium introduced between layers by reaction with sodium carbonate. In this way, the sodium content introduced by ion exchange increases the distance between layers, increases the specific surface area and pore volume, and thereby increases the water swellability and the ability to absorb saline. It is believed to be connected to.
[0030]
In addition, it is believed that the high content of alkaline earth metal has a positive effect on the increase of the metal components of the final bentonite and the increase of the interlayer hydrogen ion concentration.
[0031]
In general, acid clay contains water in the state of production. This contained water becomes an aqueous medium necessary for the reaction of sodium carbonate. In general, the moisture in the raw clay should be in the range of 10 to 35% by weight, particularly 15 to 33% by weight. Of course, when the water content in the raw clay is higher than the above range, drying is performed, and when it is lower than the above range, water may be replenished.
[0032]
It is also important that the raw clay used is uniformly mixed with sodium carbonate added in a solid state. For this purpose, it is advantageous to keep the raw clay as fine as possible prior to mixing. Generally, it is desirable that the raw clay is pulverized so that the particle size of 3000 μm or more is 30% by weight or less, particularly 20% by weight or less.
[0033]
The amount of sodium carbonate used is preferably selected from the range of 0.2 to 5% by weight, in particular 0.5 to 3.5% by weight, based on the anhydride. The optimum amount of sodium carbonate differs depending on the production area of the acid clay, but the amount of sodium that can be introduced between the layers of the above-mentioned certain raw clay is obtained, and the optimum addition amount may be determined based on this.
[0034]
The raw clay and solid sodium carbonate are mixed, and this mixture is kneaded under a temperature of 50 ° C. or higher and water retention conditions. For kneading, a uniaxial or biaxial extrusion kneader, a roll kneader, a Banbury mixer, a clay kneader, or the like can be used, and the inside of the apparatus can be maintained at a reduced pressure if necessary. In order to maintain the kneaded composition at the above temperature, frictional heat in the kneading apparatus can be used, or external heating can be used.
The temperature during the kneading reaction is suitably 50 to 100 ° C., particularly 60 to 100 ° C., and the reaction time is suitably 1.0 to 100 hours, particularly 1.0 to 20 hours.
[0035]
The kneaded reaction product is granulated by a means known per se. For granulation, known granulation methods such as compression molding method, tableting molding method, rolling granulation method, spray granulation method and extrusion granulation method are used. It is preferable to granulate.
[0036]
Bentonite granules generally have a particle size in the minimum direction of 0.5 to 8 mm, and an aspect ratio in the range of 1 to 20, which means that the absorption and adsorbent handling and the caking property during moisture absorption In addition, it is preferable in terms of removability of the solidified product. The particle shape may be any shape such as a spherical shape, a cubic shape, a cylindrical shape, a prismatic shape, a granular shape, a tablet shape, and an indefinite shape.
[0037]
The obtained granulated product is dried as necessary to obtain a product. The drying temperature is suitably 100 to 300 ° C.
The reaction can be carried out in one stage or in multiple stages. Although it is not generally necessary, for example, the reaction may be performed while kneading in the first stage, and the kneaded granulated product may be subjected to the aging reaction at the above temperature in a closed container, a muffler, or a dryer.
In completing the reaction, the moisture content in the active bentonite at the completion is 8% by weight or less, preferably 6% by weight or less, and drying conditions such as drying temperature and drying time can be arbitrarily selected.
[0038]
【Example】
The invention is illustrated in the following examples.
In the following examples, the measurement was performed by the following method.
[0039]
(1) Method for measuring pore volume The pore volume was measured by AUTOPORE II 9220 manufactured by Micromeritex.
[0040]
(2) BET surface area measurement method The BET surface area was measured by SORPTOMATIC 1900 manufactured by Carlo Elba.
[0041]
(3) Absorption capacity measuring method 100 ml of commercially available physiological saline was placed in a 100 ml measuring cylinder, 2 g of a sample was added thereto, and the swelling volume after 24 hours was measured.
[0042]
(4) Absorption rate measurement method Take 8 ml of commercial physiological saline in a 50 ml glass bottle with a lid, add 2 g of the sample to it, let it stand at room temperature, and measure the time when the fluidity of the contents of the bottle disappears due to swelling of the sample. did.
[0043]
(5) Crystallite size (unit: angstrom) measurement method X-ray diffraction conditions at the time of crystallite size measurement Using a Geiger Flex RAD-1B system manufactured by Rigaku Denki Co., Ltd.
Measured with Cu-Kα.
Target Cu
Filter Ni
Tube voltage 40 kV
Tube current 20mA
Count full scale 4 kcps
Scanning speed 0.25 deg / min
Time constant 0.5 sec
Slit DS (SS) 0.5deg RS 0.15mm
[0044]
(6) Aspect ratio measurement method Ten aspect ratios were measured per sample, and the aspect ratio was calculated from the average value excluding the maximum and minimum values.
[0045]
(7) Chemical composition Measured according to JIS M-8852 silicic acid analysis method and, if necessary, measured by atomic absorption method.
[0046]
(8) Ammonia deodorization performance measurement method 100 g of a sample is placed in a 1.8 liter glass bottle and sealed with a lid with a rubber inlet. 1 ml of 1% aqueous ammonia was added dropwise thereto. The residual gas concentration after 20 minutes was measured with a gas detector tube, and the deodorization rate was calculated by the following formula.
The blank gas concentration is measured by performing the same operation without inserting a sample.
Deodorization rate% = 100- {residual gas concentration (ppm) / blank gas concentration (ppm)
× 100}
[0047]
(9) Ethyl mercaptan deodorization performance measuring method 100 g of a sample is taken in a 1.8 liter glass bottle and sealed with a lid with a rubber inlet. 1 ml of ethyl mercaptan 0.008 w / v% ethanol solution was added dropwise thereto. The residual gas concentration after 5 minutes was measured with a gas detector tube, and the deodorization rate was calculated by the following formula.
The blank gas concentration is measured by performing the same operation without inserting a sample.
Deodorization rate% = 100− {residual gas concentration (ppm) / blank gas concentration (ppm) × 100}
[0048]
(10) Solidification test method
Place the sample in a 300 ml tall beaker to a depth of 6 cm. From above, 7 ml of 1% saline, which is an alternative to pet urine, is dropped over 10 seconds to solidify the sample and evaluate the solidified state.
The evaluation criteria are shown below.
○: Even if pressure is applied by fingers, it does not collapse easily.
Δ: collapses when pressure is applied with fingers.
X: Not solidified.
[0049]
(Example 1)
100 parts by weight of acid clay from Odo, Shibata City, Niigata Prefecture (water content 33%) and 2 parts by weight of anhydrous sodium carbonate (reagent grade 1) are mixed in an extrusion granulator, placed in a polyethylene film bag, and left at room temperature for 24 hours. . It is formed into a cylindrical shape by an extrusion granulator equipped with a granulation plate having a diameter of 3 mm and a cutting device. The molded product was dried at 150 ° C. for 10 hours to obtain a bentonite molded body. Table 1 shows the granulation conditions and the physical properties of the obtained molded body.
[0050]
(Example 2)
100 parts by weight of acid clay from Odo, Shibata City, Niigata Prefecture (33% water content) and 3.3 parts by weight of anhydrous sodium carbonate (reagent grade 1) are mixed in an extruding granulator, placed in a polyethylene film bag for 24 hours at room temperature. put. It is formed into a cylindrical shape by an extrusion granulator equipped with a granulation plate having a diameter of 3 mm and a cutting device. The molded product was dried at 150 ° C. for 10 hours to obtain a bentonite molded body. Table 1 shows the granulation conditions and the physical properties of the obtained molded body.
[0051]
(Example 3)
100 parts by weight of acid clay from Odo, Shibata City, Niigata Prefecture (33% water content) and 0.7 parts by weight of anhydrous sodium carbonate (reagent grade 1) are mixed in an extruding granulator and placed in a polyethylene film bag for 24 hours at room temperature. put. It is formed into a cylindrical shape by an extrusion granulator equipped with a granulation plate having a diameter of 3 mm and a cutting device. The molded product was dried at 150 ° C. for 10 hours to obtain a bentonite molded body. Table 1 shows the granulation conditions and the physical properties of the obtained molded body.
[0052]
Example 4
100 parts by weight of acid clay from Odo, Shibata City, Niigata Prefecture (water content 33%) and 2 parts by weight of anhydrous sodium carbonate (reagent grade 1) are mixed in an extrusion granulator, placed in a polyethylene film bag, and left at room temperature for 24 hours. . It is molded into a cylindrical shape by an extrusion granulator equipped with a granulation plate having a diameter of 1.5 mm and a cutting device. The molded product was dried at 150 ° C. for 10 hours to obtain a bentonite molded body. Table 1 shows the granulation conditions and the physical properties of the obtained molded body.
[0053]
(Comparative Example 1)
A white clay from Odo, Shibata City, Niigata Prefecture (33% moisture) is formed into a cylindrical shape by an extrusion granulator equipped with a granulation plate with a diameter of 3 mm and a cutting device. The molded product was dried at 150 ° C. for 10 hours to obtain a molded product. Table 1 shows the granulation conditions and the physical properties of the obtained molded body.
[0054]
(Comparative Example 2)
100 parts by weight of US bentonite powder and 50 parts of water are mixed well and formed into a cylindrical shape by an extrusion granulator equipped with a granulation plate having a diameter of 3 mm and a cutting apparatus. The molded product was dried at 150 ° C. for 10 hours to obtain a bentonite molded body. Table 1 shows the granulation conditions and the physical properties of the obtained molded body.
[0055]
(Comparative Example 3)
100 parts by weight of commercially available purified bentonite powder and 60 parts of water are mixed well and formed into a cylindrical shape by an extrusion granulator equipped with a granulating plate having a diameter of 3 mm and a cutting apparatus. The molded product was dried at 150 ° C. for 10 hours to obtain a bentonite molded body. Table 1 shows the granulation conditions and the physical properties of the obtained molded body.
[0056]
(Comparative Example 4)
Bentonite (moisture 33%) from Asahimura, Niigata Prefecture is formed into a cylindrical shape by an extrusion granulator equipped with a granulation plate with a diameter of 3 mm and a cutting device. The molded product was dried at 150 ° C. for 10 hours to obtain a bentonite molded body. Table 1 shows the granulation conditions and the physical properties of the obtained molded body.
[0057]
[Table 1]

[0058]
【The invention's effect】
According to the present invention, by using an active bentonite granular molded article having a metal component molar ratio (AS) in a specific range and a large specific surface area and large pore volume as a bentonite-based absorbent and adsorbent, Deodorant performance is improved compared to the above, and the absorption rate of water is large, the absorption capacity is also large, and as a result, it can absorb without leaving water, It is possible to keep the volume as small as possible, which is useful for applications such as pet litter.

Claims (2)

In toilet sand for pets consisting of granular molded products mainly composed of bentonite,
The bentonite has the following formula (1):
AS = Ax / Six (1)
In the formula, Ax represents the total molar amount of each metal component of Na, K, Mg, Ca and Fe contained in bentonite, and Six represents the unit of silica (Si) component contained in bentonite. Represents the molar amount per weight,
The metal component molar ratio (AS) defined by is 0.10 or more , and in X-ray diffraction, the crystallite size determined from the half width of the diffraction peak of the plane index (001) is 150 angstroms or less, and , Expressed as a molar ratio based on oxide,
Al ₂ O ₃ / SiO ₂ = 0.095 to 0.16
Na ₂ O / SiO ₂ = 0.8 × 10 ^{−2 to} 4.5 × 10 ⁻²
MO / SiO ₂ = 4.5 × 10 ^{−2 to} 10.5 × 10 ⁻²
Where M represents an alkaline earth metal;
And having a chemical composition represented by
The granular molded article has a pore volume of 0.15 ml / g or more and a BET specific surface area of 70 m ² / g or more as measured by mercury porosimetry, and 20 ml as measured at room temperature using physiological saline. Pet litter , characterized by having an absorption capacity of 2 g or more and an absorption rate of 30 sec / ml / g or less . The pet litter according to claim 1, wherein the granular molded product has a particle size in the minimum direction of 0.5 to 8 mm and an aspect ratio in the range of 1 to 20 .