JP2019006899A - Manufacturing method of granular treatment material - Google Patents

Abstract

To provide a manufacturing method of a granular treatment material quick in absorption of excrements or solutions, having no bleeding of moisture to a surface of the treatment agent, good in collectability after absorption and excellent in handleability when treated.SOLUTION: There is provided a manufacturing method of a granular treatment agent (X) containing a crosslinked polymer (A) containing a water-soluble vinyl monomer a1) and/or a vinyl monomer (a2) becoming (a1) by hydrolysis, and a crosslinking agent (c) as constitutional monomers, a cellulose nanofiber (B0), and a water-insoluble substrate (B) other than the (B0), having a following process (1). Process (1): mixing moisture-containing gel of the crosslinked polymer (A) and the cellulose nanofiber (B0).SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a granular processing material.

  Conventionally, as animal excrement processing materials for processing excrement of pets such as cats and dogs, granular animal excrement processing materials formed from natural sand and pulp powder into particles or fine chips are used. Has been. Although these are discarded as they are or after being absorbed as a lump after absorption of the excrement, there is a problem that handling property is poor due to the excretion of the excrement after absorption and the occurrence of slime feeling. As a treatment material for animal excrement that improves the handling of the treatment material after absorption of excrement, it has a water-insoluble base material, specific water absorption performance and average particle size, and water-soluble components and residual water-soluble monomer A treatment material for excrement of animals made of a water-absorbent resin having a specific body content is known (see Patent Document 1). Moreover, the water-containing soil processing material which absorbs the water | moisture content in a water-containing soil and granulates is known (refer patent document 2).

  However, in the conventional treatment material, the occurrence of slimy feeling due to the excretion of excrement on the surface of the treatment material was eliminated, but the cohesiveness between the treatment materials after excretion absorption (hereinafter referred to as unity) Therefore, the handleability when processing in a lump was insufficient. In the case of a hydrous soil treatment material, it took time to granulate the treatment material, and the handleability when processing in a lump was insufficient.

JP 2004-305141 A JP 2004-224969A

  The purpose of the present invention is to quickly absorb excrement and aqueous solution, not to ooze moisture to the surface of the treatment material, and to have good cohesiveness after absorption, and granular processing that is excellent in handling at the time of processing It is in providing the manufacturing method of material.

The inventor of the present invention has arrived at the present invention as a result of intensive studies to solve the above problems.
That is, the present invention relates to a water-soluble vinyl monomer (a1) and / or a crosslinked polymer (A) containing a vinyl monomer (a2) which becomes (a1) by hydrolysis and a crosslinking agent (c) as constituent monomers, cellulose It is a manufacturing method of the granular processing material (X) containing nanofiber (B0) and water-insoluble base materials (B) other than said (B0), Comprising: It is a manufacturing method which has the following process (1). .
Step (1): The water-containing gel of the crosslinked polymer (A) and the cellulose nanofiber (B0) are kneaded.

  The granular treatment material obtained by the production method of the present invention is particularly fast because it absorbs excrement and aqueous solution quickly, there is no leaching of moisture to the surface of the treatment material, and the cohesiveness after absorption is good. Excellent handling when performing.

The present invention relates to a crosslinked polymer (A) comprising a water-soluble vinyl monomer (a1) and / or a vinyl monomer (a2) which becomes (a1) by hydrolysis and a crosslinking agent (c) as constituent monomers, cellulose nano It is a manufacturing method of the granular processing material (X) containing fiber (B0) and water-insoluble base materials (B) other than said (A) and (B), Comprising: Manufacturing which has the following process (1) Method.
Step (1): Kneading water-containing gel of crosslinked polymer (A) and cellulose nanofiber (B0) This granular treatment material (X) is suitable for absorption and water absorption, especially for animal excrement, Suitable for hydrous soil treatment.

  Here, the crosslinked polymer (A) is preferably a monomer composition containing a water-soluble vinyl monomer (a1) and / or a vinyl monomer (a2) that becomes (a1) by hydrolysis and a crosslinking agent (c). It is a crosslinked polymer obtained by polymerization.

<Water-soluble vinyl monomer (a1)>
The water-soluble vinyl monomer (a1) in the present invention is not particularly limited, and carboxyl group, carboxylate group, sulfo group, sulfonate group, amino group, carbamoyl group, ammonio group or mono-, di- or tri-alkyl ammonio group. Known vinyl monomers having a group [for example, vinyl monomers having at least one water-soluble substituent and an ethylenically unsaturated group disclosed in Japanese Patent No. 3648553 (anionic vinyl monomers, nonionic vinyl monomers) And anionic vinyl monomers, nonionic vinyl monomers and cationic vinyl monomers disclosed in JP-A No. 2003-165883, and carboxy groups disclosed in JP-A No. 2005-75982. , Sulfo group, phosphono group, Acid, a carbamoyl group, a vinyl monomer such as vinyl monomers, etc.] having at least one selected from the group consisting of amino group and an ammonio group may be used.

<Vinyl monomer (a2) which becomes water-soluble vinyl monomer (a1) by hydrolysis>
The vinyl monomer (a2) that becomes the water-soluble vinyl monomer (a1) by hydrolysis in the present invention is not particularly limited, and known {for example, disclosed in Japanese Patent No. 3648553, which becomes a water-soluble substituent by hydrolysis. A vinyl monomer having at least one hydrolyzable substituent and at least one hydrolyzable substituent [1,3-oxo-2-oxapropylene (—CO—) disclosed in JP-A-2005-75982 Vinyl monomer etc. having O—CO—) group, acyl group, cyano group etc.} can be used.
“Water-soluble vinyl monomer” means a vinyl monomer that dissolves at least 100 g in 100 g of water at 25 ° C., and “becomes water-soluble vinyl monomer by hydrolysis” means water and, if necessary, a catalyst (acid or base, etc. ) To be hydrolyzed to become a water-soluble vinyl monomer.
The hydrolysis of (a2) may be performed during polymerization or after polymerization of the monomer composition containing (a1) and / or (a2) and (c). Although it may be performed both later, it is preferably performed after polymerization from the viewpoint of the absorption performance of the crosslinked polymer (A).

Of the above (a1) and (a2), from the viewpoint of absorption performance and the like, a C3-C30 vinyl group-containing carboxylic acid (salt) {unsaturated monocarboxylic acid (salt) [(meth) acrylic acid, crotonic acid , Cinnamic acid and salts thereof]; unsaturated dicarboxylic acid (salt) (maleic acid, fumaric acid, citraconic acid, itaconic acid and salts thereof, etc.); 8) Esters (maleic acid monobutyl ester, fumaric acid monobutyl ester, maleic acid ethyl carbitol monoester, fumaric acid ethyl carbitol monoester, citraconic acid monobutyl ester, itaconic acid glycol monoester, etc.) are preferred. More preferably an unsaturated dicarboxylic acid (salt), particularly preferably (meth) acrylic acid (salt), most preferably It is an acrylic acid (salt).
“(Meth) acryl” means “acryl” and / or “methacryl”, and “... acid (salt)” means “... acid” and / or “... acid salt”.

Examples of unsaturated monocarboxylic acid salts and unsaturated dicarboxylic acid salts include alkali metal (such as lithium, sodium and potassium), alkaline earth metal (such as magnesium and calcium) salts of unsaturated monocarboxylic and unsaturated dicarboxylic acids, and ammonium (NH ₄₎ salts. Among these salts, alkali metal salts and ammonium salts are preferable from the viewpoint of absorption performance and the like, more preferably alkali metal salts, and particularly preferably sodium salts.

  When the salt of an anionic vinyl monomer (such as a vinyl monomer having a carboxyl group and a sulfonate group) is included as the (a1), the anionic vinyl monomer relative to the total number of moles of the anionic vinyl monomer and the salt included as the (a1) The ratio of the total number of moles of the salt (hereinafter referred to as the degree of neutralization of the anionic vinyl monomer) is preferably 30 to 100 mol%, more preferably 40 to 90 mol%, particularly preferably 50 to 90 mol%. It is. This range is preferable because the absorption rate is further improved.

Any one of (a1) and (a2) may be used, or two or more may be used in combination.
When the above (a1) and (a2) are used in combination, the content ratio (molar ratio) [(a1) / (a2)] in these monomer compositions is 75/25 to 99/1. More preferably, it is 85/15 to 95/5, particularly preferably 90/10 to 93/7, and most preferably 91/9 to 92/8. Within this range, the absorption performance is further improved.

  The monomer composition containing the (a1) and (a2) and the crosslinking agent (c) can further contain another vinyl monomer (a3) copolymerizable therewith.

  The (a3) is not particularly limited, and is known (for example, a hydrophobic vinyl monomer disclosed in Japanese Patent No. 3648553, Japanese Patent Laid-Open No. 2003-165883, Japanese Patent Laid-Open No. 2005-75982). Hydrophobic vinyl monomers such as vinyl monomers can be used, and aromatic ethylenic monomers having 8 to 30 carbon atoms {styrene, α-methylstyrene, vinyltoluene, hydroxystyrene, vinylnaphthalene, and halogen substituted products of styrene (dichloro) Styrene, etc.), aliphatic ethylenic monomers having 2 to 20 carbon atoms [alkene (ethylene, propylene, butene, isobutylene, pentene, heptene, diisobutylene, octene, dodecene, octadecene, etc.) and alkadienes (butadiene, isoprene, etc.) Etc.] and 5 to 5 carbon atoms 5 alicyclic ethylenic monomer [monoethylenically unsaturated monomer (pinene, limonene and indene) and polyethylene vinyl monomer (cyclopentadiene, bicycloalkyl cyclopentadiene and ethylidene norbornene, etc.) and the like]}, and the like.

  The content (mol%) in the monomer composition (a3) is 0 to 5 mol% based on the total number of moles of (a1) and (a2) from the viewpoint of absorption performance and the like. Preferably, it is 0 to 3 mol%, particularly preferably 0 to 2 mol%, and most preferably the content of the unit (a3) is 0 mol% from the viewpoint of absorption performance and the like.

In the present invention, the crosslinked polymer (A) has a group (hereinafter referred to as a hydrolyzable group) that is hydrolyzed under alkaline conditions in the structural unit derived from (c). Preferable examples of the hydrolyzable group include an ester group and an amide group.
The hydrolyzable group may have (c) in the molecule, and (c) is a monomer constituting the (A) [the (a1) and / or the (a2) ] And the group produced | generated by reaction may be a hydrolysable group.

  As the crosslinking agent (c1) having a hydrolyzable group in the molecule, a (meth) acrylic acid ester having 2 to 10 (meth) acryloyl groups and having 8 to 40 carbon atoms [ethylene glycol di (meta ) Acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate and pentaerythritol tetra ( (Meth) acrylate and polyglycerin (degree of polymerization 3 to 13) polyacrylate and the like] and (meth) acrylic acid amide [N, N′-methylenebis] having 2 to 10 (meth) acryloyl groups and having 7 to 30 carbon atoms. Acrylamide and N, N ′-(oxybis Styrene) bis acrylamide], and the like.

  The crosslinker (c2) in which the group generated by reacting with (a1) and / or (a2) is a hydrolyzable group is an ester that reacts with the carboxyl group or carboxylate group of (a1). A reactive crosslinking agent that forms a group and / or an amide group. Examples of the reactive crosslinking agent that forms an ester group include polyvalent epoxides having 8 to 40 carbon atoms [ethylene glycol diglycidyl ether and polyethylene (degree of polymerization: 3 -13) diglycidyl ether and the like] and polyhydric alcohols having 3 to 40 carbon atoms having no (meth) acryloyl group or allyl group [glycerin and polyglycerol (degree of polymerization 3 to 13) etc.], etc. Examples of reactive crosslinking agents that form groups include polyisocyanates having 4 to 22 carbon atoms (ethylene diisocyanate, 2-isocyanatoethyl- , 6-diisocyanatohexanoate, 1,3- or 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate and 4,4 ′, 4 ″ -triphenylmethane triisocyanate) and 2 to 2 carbon atoms 36 polyamines [ethylenediamine and poly (n = 2-6) alkylene (2-6 carbon atoms) poly (n = 3-7) amine, etc.] and the like.

  The reaction between the (a1) and / or the (a2) and the crosslinking agent (c2) is 100 to 230 ° C. (preferably 120 to 120 ° C.) at any stage after the addition of the crosslinking agent during the polymerization reaction (A). 160 ° C.) and the crosslinking reaction is allowed to proceed.

Of the above (c1) and (c2), from the viewpoint of unity, the above (c1) and a polyhydric epoxide having 8 to 40 carbon atoms are preferable, and more preferably N, N′-methylenebisacrylamide, ethylene glycol di ( (Meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate and polyvalent glycidyl compounds, particularly preferably N, N'-methylenebisacrylamide, ethylene glycol di (Meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate and ethylene glycol diglycidyl ether, most preferably N, N′-methylenebisacrylamide, triethyleneglycol Distearate (meth) acrylate, trimethylolpropane tri (meth) acrylate and ethylene glycol diglycidyl ether.
In the above (c), any one kind may be used alone as a structural unit, or two or more kinds may be used in combination as a structural unit.

  The weight ratio (% by weight) in the monomer composition of the cross-linking agent (c) is based on the total weight of the above (a1) and (a2) from the viewpoint of shape retention of the granular treatment material for animal excretion. 0.05 to 2% by weight, more preferably 0.05 to 1% by weight, particularly preferably 0.1 to 0.8% by weight, and most preferably 0.2 to 0.6% by weight. .

The cross-linked polymer (A) does not have a hydrolyzable group and may contain a cross-linking agent (d) that does not generate a hydrolyzable group by reacting with the monomer constituting the (A). good.
When the above (d) is included, a crosslinking agent (d1) having two or more vinyl ether bonds, a crosslinking agent (d2) having two or more allyl ether bonds, and the like are mentioned. Crosslinking agents having d2) are preferred.

  Examples of (d1) include ethylene glycol divinyl ether, 1,4-butanediol divinyl ether, 1,4-cyclohexanedimethanol divinyl ether, 1,6-hexanediol divinyl ether, and polyethylene glycol divinyl ether (degree of polymerization of 2 to 5). ), Bisphenol A divinyl ether, pentaerythritol trivinyl ether, sorbitol trivinyl ether, polyglycerin (degree of polymerization 3 to 13) polyvinyl ether, and the like.

As the above (d2), a crosslinking agent (d2-1) having two allyl groups in the molecule and having no hydroxyl group [diallyl ether, 1,4-cyclohexanedimethanol diallyl ether, alkylene (carbon number 2 5) Glycol diallyl ether and polyethylene glycol (weight average molecular weight: 100 to 4000) diallyl ether and the like], a crosslinking agent having two allyl groups and 1 to 5 hydroxyl groups in the molecule (d2-2) [glyceryl diallyl ether , Trimethylolpropane diallyl ether, pentaerythritol diallyl ether, polyglycerin (degree of polymerization 2-5) diallyl ether, etc.], a crosslinking agent having 3 to 10 allyl groups in the molecule and no hydroxyl group (d2-3 ) (Trimethylolpropane triallyl ether, glycerol triallyl ether, pe Taerythritol tetraallyl ether, tetraallyloxyethane and the like) and a crosslinking agent having 3 to 10 allyl groups and 1 to 3 hydroxyl groups in the molecule (d2-4) [pentaerythritol triallyl ether and diglyceryl triallyl Ether, sorbitol triallyl ether, polyglycerin (degree of polymerization 3 to 13) polyallyl ether and the like] and the like.
(D) may use 2 or more types together.

  When the above (d) is used, a crosslinking agent (d2) having two or more allyl ether bonds is preferable, more preferably (d2-2) and (d2-4), and particularly preferably (d2-2). And most preferred are trimethylolpropane diallyl ether, pentaerythritol triallyl ether and pentaerythritol diallyl ether.

  The content (% by weight) of (d) in the monomer composition containing (a1), (a2) and (c) is from 0 to 1.99% by weight from the viewpoint of absorption performance and the like. Is preferable, and more preferably 0 to 0.95% by weight.

The crosslinked polymer (A) is prepared by subjecting a monomer composition containing the above (a1) and / or the above (a2) and the above (c) to a known aqueous polymerization (described in JP-A No. 55-133413). Polymerization, thin film polymerization, spray polymerization, etc.) and known suspension polymerization (Suspension polymerization and reverse method described in JP-B-54-30710, JP-A-56-26909, JP-A-1-5808, etc.) The hydrogel of the crosslinked polymer (A) obtained by polymerizing by phase suspension polymerization or the like can be obtained by heating, drying and pulverizing if necessary.
In the above, it is preferable to knead the step (1): the hydrogel of the crosslinked polymer (A) and the cellulose nanofiber (B0).

  Among these polymerization methods, from the viewpoint of absorption performance and the like, aqueous solution polymerization, reverse phase suspension polymerization and emulsion polymerization are preferable, more preferably aqueous solution polymerization and reverse phase suspension polymerization, and particularly preferably reverse phase suspension polymerization. .

The aqueous solution polymerization may be performed by polymerizing an aqueous monomer composition solution obtained by dissolving the monomer composition containing (a1), (a2) and (c) as essential components in water. I can do it.
When the aqueous solution polymerization method is performed, the concentration (% by weight) of the monomer composition contained in the monomer composition aqueous solution is preferably 10 to 40% by weight, more preferably 10 to 30% by weight. Within this range, crosslinking of the monomer itself (self-crosslinking) is unlikely to occur, and temperature control during polymerization is facilitated, which is preferable.
When aqueous solution polymerization is performed, a water-soluble organic solvent (methanol, ethanol, acetone, methyl ethyl ketone, N, N-dimethylformamide, dimethyl sulfoxide, and a mixture of two or more thereof) can be used in combination.
In aqueous polymerization, the amount of water-soluble organic solvent used is preferably 40% or less, more preferably 30% or less, based on the weight of water.

Reverse-phase suspension polymerization is a monomer composition comprising (a1), (a2) and (c) in a known hydrophobic organic solvent (hexane, toluene, xylene, normal hexane, normal heptane, etc.). Or it can carry out by suspending and polymerizing monomer composition aqueous solution.
In the reverse phase suspension polymerization, when the aqueous monomer composition solution is suspended in the hydrophobic organic solvent, the aqueous monomer composition solution can be the same as the aqueous solution polymerization described above, and can be used in combination. The same is true for the organic solvent.
The concentration of the monomer composition contained in the aqueous monomer composition solution is preferably 10 to 40% by weight, more preferably 10 to 30% by weight, based on the total weight of the aqueous solution. Within this range, the degree of polymerization of the crosslinked polymer (A) will be good.

Reverse phase suspension polymerization may be carried out in the presence of a known surfactant and / or dispersant.
Examples of the surfactant include sorbitan fatty acid esters (such as sorbitan monostearic acid ester), glycerin fatty acid esters (such as glycerin monostearic acid ester), and sucrose fatty acid esters (such as sucrose distearic acid ester).
Examples of the dispersant include a polymer dispersant having a hydrophilic group in the molecule and soluble in a solvent in which the aqueous monomer solution is dispersed (for example, the hydrophilic group is 0.1 to 0.1 based on the weight of the polymer dispersant). 20% by weight, a polymer dispersant having a weight average molecular weight of 1,000 to 1,000,000) can be used, and an ethylene / acrylic acid copolymer maleate, ethylene / vinyl acetate copolymer Examples thereof include a maleated compound and a styrene sulfonic acid (salt) / styrene copolymer.
Among them, it is preferable to use a polymer dispersant as the dispersant because the crosslinked polymer particles can be easily adjusted.
The amount of the dispersant added is preferably 0.1 to 20% by weight, more preferably 0.5 to 10% by weight, based on the weight of the hydrophobic organic solvent, from the viewpoint of absorption performance.

  In the reverse phase suspension polymerization, the weight ratio of the aqueous monomer composition to the weight of the hydrophobic organic solvent is preferably 0.1 to 2.0, more preferably 0.3 to 1.0. Within these ranges, it becomes easier to adjust the particle diameter of the crosslinked polymer.

  The polymerization of the monomer composition containing the (a1) and / or the (a2) and the (c) may be performed using an energy beam (radiation, ultraviolet ray, electron beam, etc.) even if polymerization is performed using a radical polymerization initiator. ) May be carried out by polymerization, but polymerization is preferably carried out using a radical polymerization initiator.

As radical polymerization initiators, azo compounds [azobisisobutyronitrile, azobiscyanovaleric acid and 2,2′-azobis (2-amidinopropane) hydrochloride, etc.], inorganic peroxides (hydrogen peroxide, ammonium persulfate, Potassium persulfate, sodium persulfate, etc.), organic peroxides [benzoyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, succinic peroxide, and di (2-ethoxyethyl) peroxydicarbonate, etc.] And redox catalysts [reducing agents (ammonium sulfite, ammonium bisulfite, ascorbic acid, alkali metal sulfites, alkali metal bisulfites, etc.) and oxidizing agents (alkali metal persulfates, ammonium persulfates, hydrogen peroxide and organics) A combination of peroxide and the like] Can be mentioned.
These radical polymerization initiators may be used alone or in combination of two or more.
The amount of the radical polymerization initiator used is preferably from 0.0005 to 5% by weight, more preferably from 0.001 to 2% by weight, based on the total weight of (a1) and (a2).

  The polymerization temperature in the case of using a radical polymerization initiator is adjusted depending on the kind of the initiator to be used, but from the viewpoint of the degree of polymerization of (A), preferably −10 ° C. to 100 ° C., more preferably − 10 ° C to 80 ° C.

The amount of dissolved oxygen at the time of polymerization can be adjusted according to the amount of radical initiator added, etc., but from the viewpoint of absorption performance and the like, 0 to 2 ppm (2 × 10 ⁻⁴ wt% or less) is preferable, and more preferable. Is 0 to 0.5 ppm (0.5 × 10 ⁻⁴ wt% or less).

When (meth) acrylate is included as (a1), the neutralization degree of the anionic vinyl monomer is such that the monomer composition aqueous solution containing (a1), (a2) and (c) is uniform. It is preferable that the degree of neutralization is as follows.
Since (a2) is less soluble in (meth) acrylate aqueous solution than (a1), (a2) is separated in the monomer composition aqueous solution, and a uniform crosslinked polymer is obtained. There may not be. In addition, (meth) acrylic acid tends to have a higher degree of polymerization and better absorption performance as the degree of neutralization is lower.
When the monomer composition aqueous solution is separated when the required amount of (meth) acrylate is used, the polymerization is carried out at a neutralization degree of 0 to 30 mol%, and further neutralized after the polymerization. The degree of neutralization is preferred. More preferably, the degree of neutralization is set after polymerization in an unneutralized state.

  When using a solvent (such as an organic solvent and water) for the polymerization, it is preferable to remove the solvent after the polymerization. When the solvent contains an organic solvent (water-soluble organic solvent and hydrophobic organic solvent), the content of the organic solvent after removal is preferably 0 to 10% by weight, more preferably based on the weight of (A). It is 0 to 5% by weight, particularly preferably 0 to 3% by weight, and most preferably 0 to 1% by weight. Within this range, the absorption performance of the aqueous liquid absorbent resin particles is further improved.

  When water is used as the solvent, the water after removal is preferably 0 to 20% by weight, more preferably 1 to 10% by weight, particularly preferably 2 to 9% by weight, based on the weight of (A). Most preferably, it is 3 to 8% by weight. Within this range, the absorption performance is further improved.

  The content and water content of the organic solvent are determined using an infrared moisture meter [JE400 manufactured by KETT Co., Ltd .: 120 ± 5 ° C., 30 minutes, ambient humidity 50 ± 10% RH before heating, lamp specification 100V, 40W] It is determined from the weight loss of the measurement sample before and after heating.

  As a method for removing the solvent, a method of heating and drying with hot air, a thin film drying method using a drum dryer or the like, a vacuum drying method, a freeze drying method, a drying method using infrared rays, decantation and filtration can be applied.

  Among them, as a method of distilling off the solvent from the water-containing gel obtained by aqueous solution polymerization, a gas-permeation drying method (a method of drying by punching metal or a water-containing gel laminated on a screen by blowing hot air) and a method of air-flow drying ( Air-drying in a rotating container such as a rotary kiln containing water-containing gel) and the like, and air drying is preferable because efficient drying can be performed in a short time.

When removing the solvent by heating, the heating temperature is adjusted depending on the dryer used, the drying time, and the like, but is preferably 50 to 150 ° C, more preferably 80 to 130 ° C.
When the heating temperature is 150 ° C. or lower, the crosslinking in (A) due to heat during drying hardly occurs, and the absorption performance does not deteriorate. Further, when the temperature is 50 ° C. or higher, drying does not require a long time and it is efficient.
The drying time varies depending on the model of the dryer used and the drying temperature, but is preferably 5 to 300 minutes, more preferably 5 to 120 minutes.

  As a method for distilling off the solvent from the hydrogel obtained by the reverse phase suspension polymerization, the hydrogel and the organic solvent are solid-liquid separated by a method such as decantation and then dried under reduced pressure (degree of vacuum; 100 to 50,000 Pa). Degree) or aeration drying is preferred.

  The hydrogel obtained by polymerization can be shredded as necessary before the solvent is distilled off. The size (longest diameter) of the gel after chopping is preferably 50 μm to 10 cm, more preferably 100 μm to 2 cm, and particularly preferably 1 mm to 1 cm. Within this range, the drying property in the drying process is further improved.

  Shredding can be performed by a known method, and can be performed using a normal shredding device (for example, a bex mill, rubber chopper, pharma mill, mincing machine, impact crusher, and roll crusher). .

  Said (A) obtained by superposing | polymerizing can further be grind | pulverized after drying. The pulverization method is not particularly limited, and a normal pulverizer (for example, a hammer pulverizer, an impact pulverizer, a roll pulverizer, and a shet airflow pulverizer) can be used.

The pulverized (A) can be adjusted in particle size by sieving using a sieving machine (vibrating sieving machine, centrifugal sieving machine, etc.) equipped with a desired screen. Volume average particle diameter of (A) when sieving (Μm) is preferably 1 to 800, more preferably 5 to 500, particularly preferably 10 to 300, particularly preferably 15 to 200, and most preferably 15 to 110. Within this range, the absorption performance is further improved.

  The volume average particle diameter of (A) is measured with a laser diffraction particle size distribution analyzer [Microtrack (Nikkiso Co., Ltd.)] in which (A) is dispersed in methanol.

The content of fine particles contained in (A) when the particle size is adjusted is the content of fine particles of 106 μm or less (preferably 150 μm or less) based on the total weight of (A) from the viewpoint of absorption performance and the like. Is preferably 5% by weight or more, more preferably 10% by weight or more, and particularly preferably 20% by weight or more.
The content of the fine particles can be determined by the laser diffraction particle size distribution measuring apparatus.

  The shape of (A) is not particularly limited, and examples thereof include an irregularly crushed shape, a flake shape, a pearl shape, and a rice grain shape. Among these, since the intensity | strength of a granular processing material becomes favorable, an amorphous crushing shape, pearl shape, and rice grain shape are preferable.

<Cellulose nanofiber (B0)>
As cellulose nanofiber (B0) in this invention, it is a well-known thing, Preferably a number average fiber diameter is a 1-200 nm thing. The number average fiber diameter is more preferably 1 to 100 nm, particularly preferably 5 to 50 nm.

<Water-insoluble substrate (B)>
Examples of the water-insoluble substrate (B) include those other than the above (A) and (B0), and examples of the water-insoluble substrate (B) include inorganic particles, inorganic porous bodies, inorganic fibers, organic particles, organic short fibers, Examples include paper shredded products, organic porous bodies, organic foams, and granulated products thereof. Among these, inorganic particles, organic particles, organic short fibers, paper shredded products, and granulated products thereof from the viewpoint of cohesiveness. Are preferable, and more preferably at least one granulated product selected from the group consisting of inorganic particles, organic particles, organic short fibers, and paper shredded products. These may be used alone or in combination of two or more.

Examples of the inorganic particles include soil, sand, fly ash, diatomaceous earth, clay, talc, kaolin, bentonite, dolomite, calcium carbonate, alumina, and dredged sand.
Examples of the inorganic porous material include Filton, porous ceramic, lignite, calcined vermiculite, pumice, volcanic ash, zeolite, and shirasu balloon.
Examples of the inorganic fiber include rock wool and glass fiber, and examples of the inorganic foam include pearlite.

Organic particles include dry plant powder (coconut shell, rice cracker, sawdust, wood waste and wood powder, and peanut shells, citrus shells and coconut shells, etc.), synthetic resin powders (polyethylene powder, polypropylene powder, ethylene, etc.) -Vinyl acetate copolymer powder, etc.) and rubber powder.
Organic short fibers include natural fibers (cotton, straw, grass charcoal, peat moss, wool, etc.), synthetic fibers (rayon, acetate, polyamide, polyester, acrylic, etc.), pulp [mechanical pulp (crushed wood pulp from logs and asprund method) Pulp, etc.), chemical pulp (sulfite pulp, soda pulp, sulfate pulp, nitrate pulp, chlorine pulp, etc.) and recycled paper recycled pulp, etc.].
Examples of paper shredded products include shredded products obtained by cutting paper products (newspapers, magazines, paperboards, etc.) obtained by making the above pulp using a known machine (shredders, etc.).
Examples of the organic porous body include activated carbon and paper sludge. Examples of the organic foam include foams of cereals (corn, etc.) and synthetic resins (polystyrene, polyvinyl acetal, rubber, polyethylene, polypropylene, urethane resins, etc.). Can be mentioned.

  The shape of (B) other than (B0) is not limited to the same, but when it is particulate, the major axis of the particle is preferably 1-1000 μm, more preferably 10-500 μm, and (B) When the shape of the fiber is fibrous, the fiber length is preferably 0.001 to 20 mm, and more preferably 0.01 to 10 mm.

  As a method of producing the granulated product of (B), a method of granulating the (B) with mechanical stirring with a small amount of water (stirring granulation method) and a method of granulating by pressure molding ( Pressure molding method) and the like.

The agitation granulation method is a granulated product obtained by stirring (B) with a small amount of water using a known mechanical mixing device (Nauter mixer, ribbon mixer, conical blender, mortar mixer, universal mixer, etc.). Can be obtained.
Examples of the method of adding water include a method of spraying with stirring, a method of blowing water vapor with stirring, and a method of absorbing the moisture while maintaining the (B) under high humidity.
In the stirring granulation method, from the viewpoint of granulation strength and first aid performance, inorganic salts, adhesives (starch, CMC, guar gum, etc.), low molecular glycols (ethylene glycol, glycerin, etc.), water-soluble polymers as necessary (Polyvinyl alcohol and polyethylene glycol, etc.) and surfactants can be used in combination.

In the stirring granulation method, the amount of water to be added is adjusted depending on the type of (B), but from the viewpoint of granulation strength and the like, preferably 1 to 100% by weight based on the weight of (B), More preferably, it is 2 to 50% by weight.
Although the temperature conditions at the time of stirring are not specifically limited, Granulation speed | rate, granulation intensity | strength, etc. become favorable by performing in the state heated at 40-90 degreeC.

Examples of the pressure molding method include a method of pressure-molding the above (B) into a sheet shape, a rod shape, a block shape, a pellet shape, or the like using a mold having an appropriate shape or size as required. The granulated product produced by the pressure molding method may be cut or pulverized to an appropriate size.
Although the temperature and humidity at the time of pressure molding are not particularly limited, it is usually performed at room temperature, and is performed under conditions of heating (for example, 30 to 300 ° C.) and humidification (for example, 50 to 100% RH). Also good. The pressure at the time of pressure molding can be adjusted according to the type, particle size, properties, etc. of the substrate, but is preferably 1 to 3,000 kg / cm ² , more preferably 10 to 2,000 kg / cm ² . is there.

  Pressure molding is a known molding machine such as a roll-type pressure molding machine (compacting press machine, briquetting press machine, etc.), a piston-type pressure molding machine, a screw-type pressure molding machine, and an eye plate extrusion-type molding machine. Can be used.

  Examples of the shape of the granulated product include a spherical shape, a cylindrical shape, a plate shape, a rock shape, a rectangular parallelepiped shape, a conical shape, a pyramid shape, and a rod shape. In any shape, the size is 0.1 to 30 mm, preferably 0.3 to 20 mm, more preferably 0.5 to 15 mm, and particularly preferably 1 to 10 mm in maximum diameter or maximum length.

<Granular processing material (X)>
As the granular processing material (X) in the present invention, the above (A) [for example, the water-containing gel (A) and (B0) are kneaded and dried. That is, (A) and (B0) are included] and the above-mentioned (B) simple mixed processing material, and (A) and the granulated type (B) not granulated are mixed and granulated. Examples thereof include a material and a surface-attached treatment material in which (A) is adhered to the surface of (B), and a granulation-type treatment material and a surface-attachment-type treatment material are preferable.

The simple mixing type treatment material can be obtained by mixing (A) and (B) with (A) and (B) in a known mechanical mixing device.
In addition, at the time of mixing the said (A) and the said (B), a water absorption promoting material and water absorbing materials other than the said (A) can be used together as needed. As the water absorption promoting material, an inorganic or organic fibrous substance that can quickly hold a liquid by capillary action can be used. As the water-absorbing material other than the above (A), any water-absorbing polymer such as polyvinyl alcohol and polyacrylamide can be used without limitation as long as it is usually used as a treatment material. The size of the water absorption material other than the water absorption promoting material and (A) is preferably 1 to 500 μm.

The granulation-type treatment material can be obtained by the same method as the method of producing the granulated product of (B) using (A) and (B) which is not granulated.
In the granulated processing material, a binder, a water absorption promoting material, and a water absorbing material other than (A) can be used in combination as necessary. As the binder, a known material, an adhesive such as starch, CMC, guar gum and the like is preferable. As the water absorption material other than the water absorption promoting material and (A), the same materials as described above can be used. The size of the water absorbing material other than the binder, the water absorption promoting material and (A) is preferably 1 to 500 μm.

The surface adhesion type treatment material can be obtained by adhering the (A) to the surface of the (B), and the (A), (B) and binding components (water, binder, etc.) are publicly known. It is obtained by mixing in a mechanical mixing device.
The binder component is preferably water, and the water content is preferably 1 to 100% by weight, more preferably 2 to 50% by weight, based on the weight of (B). When the (B) has moisture, the moisture becomes a binding component, and the (A) adheres to the surface of the granulated product. When the moisture exceeds 100% by weight, the (A) becomes gel-like. This is not preferable because the adhesive strength decreases.

In the granular processing material (X) in the present invention, the weight ratio of the (A) and the (B) is not particularly limited, but the weight of the (A) is 1 to 50 weights with respect to the weight of the (B). %, More preferably 3 to 30% by weight. When the amount is 1% by weight or more, the absorption rate of excrement such as animal urine is increased, and the cohesiveness between the treatment agents is improved and the balls are easily solidified. The amount of 50% or less is economical and preferable.
In (X), the weight ratio [(B0) / (A)] of the cellulose nanofiber (B0) and the crosslinked polymer (A) is preferably 0.1 / from the standpoint of unity and industrial viewpoint. It is 99.9-20 / 80, More preferably, it is 0.5 / 99.5-10 / 90, Most preferably, it is 1 / 99-5 / 95.

In the granular processing material of the present invention, if necessary, a deodorant, a fragrance, a bactericidal agent, a fungicide, a preservative, a surfactant, a color change agent that absorbs urine, a matabi on a cat, etc. Other additives such as incentives and bulking agents preferred by pets can be included.
When other additives are contained, the content is usually 0.01 to 10% by weight based on the weight of the treatment material.
The order of addition of other additives may be previously added to the granulated product of (A), (B) or (B), and (A) and (B) or It may be added in the step of mixing with the granulated product of (B), or may be added and mixed with the manufactured treatment material.

  The granular processing material in the present invention can be used, for example, in the form of a simple toilet by spreading the granular processing material of the present invention in a container. When animals such as cats and dogs are excreted in this toilet, the water of the excrement is quickly absorbed, and the parts that have absorbed water adhere to each other and form a single rubbery mass, making the part easy It is convenient to dispose of it.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
Hereinafter, unless otherwise specified,% represents% by weight.

<Example 1>
In a 2-liter beaker, add 300 g of acrylic acid, 1.35 g of trimethylolpropane triacrylate (0.45% acrylic acid) and 700 g of ion-exchanged water, and mix by stirring to prepare an aqueous acrylic acid solution and cool to 4 ° C. did.
The acrylic acid aqueous solution was put into a 1.5 liter adiabatic polymerization tank, and the dissolved oxygen amount in the acrylic acid aqueous solution was adjusted to 0.1 ppm or less through nitrogen in the aqueous solution. To this adiabatic polymerization layer, 12 g of 0.1% hydrogen peroxide solution, 12 g of 0.1% L-ascorbic acid aqueous solution and 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) with a concentration of 2% -Propionamide] (trade name: VA-086, manufactured by Wako Pure Chemical Industries, Ltd.) 5.0 g of an aqueous solution was added, and nitrogen aeration into the aqueous solution was continued until polymerization started. After confirming that the polymerization started and the viscosity of the acrylic acid aqueous solution started to rise, the nitrogen aeration was stopped and the polymerization was carried out for 6 hours. When the temperature of the acrylic acid aqueous solution was measured with a hot spot thermometer, the maximum temperature reached was 97 ° C.
The water-containing gel obtained after the polymerization was taken out from the adiabatic polymerization tank, and the gel was subdivided into a noodle with a thickness of 3 to 10 mm using a small meat chopper (manufactured by Royal), and then 40% sodium hydroxide (Reagent special grade) Aqueous gel was neutralized by adding 260 g of an aqueous solution (corresponding to a neutralization degree of acrylic acid of 75 mol%).
200 g of a hydrogel of the crosslinked polymer (A-1) obtained above [of which the crosslinked polymer is 50% by weight] and a commercially available cellulose nanofiber [number average fiber diameter 30 nm, average aspect ratio 130] (B0-1) 5.25 g was kneaded using a small meat chopper (Royal) and laminated on a SUS screen with an opening of 850 μm at a thickness of 5 cm. The water-containing gel was dried by passing hot air at 120 ° C. through the water-containing gel for 1 hour.
The dried product was pulverized using a cooking mixer, and a sieve having a particle size of 500 μm (40 mesh) or less was collected using a sieve to obtain a crosslinked polymer (A0-1) containing (B0). The volume average particle diameter of the crosslinked polymer (A0-1) was 300 μm.
(A0) includes (B0) and (A), but for convenience, a cross-linked polymer was used.

Next, 500 g of a commercially available bentonite “Kunigel V-1” (manufactured by Kunimine Kogyo Co., Ltd.) is placed in a small universal mixer having an internal volume of 2 liters kept at about 50 ° C. and stirred at a speed of 100 rpm. 50 ml of water warmed to about 50 ° C. was added little by little and granulated.
Once stirring was stopped and it was confirmed that a hard granulated product of about 2 to 6 mm was formed, 50 g of the crosslinked polymer (A0-1) obtained above was added to 500 g of this granulated product, and again The mixture was stirred at a rate of 100 rpm and adhered to the surface of the granulated material to obtain a granular treated material (X-1).

<Example 2>
A crosslinked polymer (A-2) was prepared in the same manner as in Example 1 except that “particle size of 500 μm (40 mesh) or less” in Example 1 was changed to “particle size of 45 μm or less (350 mesh)”. Got. The volume average particle diameter of the crosslinked polymer (A0-2) was 30 μm.
Next, a granular treated material (X-2) was obtained in the same manner as in Example 1.

<Example 3>
A crosslinked polymer (A0-3) was obtained in the same manner as in Example 1 except that “particle diameter of 500 μm (40 mesh) or less” in Example 3 was changed to “20 μm or less (635 mesh)”. . The volume average particle diameter of the crosslinked polymer (A0-3) was 15 μm.
Next, a granular treated material (X-3) was obtained in the same manner as in Example 1.

<Example 4>
In Example 1, 1.35 g of trimethylolpropane triacrylate (0.45% acrylic acid) was changed to 0.6 g of N, N′-methylenebisacrylamide (0.2% acrylic acid). A crosslinked polymer (A0-4) was obtained in the same manner as in Example 1 except that “particle diameter of 500 μm (40 mesh) or less” was changed to “particle diameter of 180 μm or less (83 mesh)”. The volume average particle diameter of the crosslinked polymer (A0-4) was 110 μm.
Next, a granular treated material (X-4) was obtained in the same manner as in Example 1.

<Example 5>
In Example 1, 1.35 g of trimethylolpropane triacrylate (0.45% acrylic acid) was changed to 1.8 g of ethylene glycol diglycidyl ether (0.6% acrylic acid) and 500 μm (40% A crosslinked polymer (A0-5) was obtained in the same manner as in Example 1 except that the particle size “mesh)” was changed to “300 μm or less (50 mesh)”. The volume average particle diameter of the crosslinked polymer (A0-5) was 200 μm.
Next, a granular treated material (X-5) was obtained in the same manner as in Example 1.

<Example 6>
In Example 1, 1.35 g of trimethylolpropane triacrylate (0.45% acrylic acid) was changed to 0.3 g of trimethylolpropane triacrylate (0.1% acrylic acid) and pentaerythritol triallyl ether 0 .15 g (0.05% acrylic acid) ”and“ particle diameter of 500 μm (40 mesh) or less ”was changed to“ particle diameter of 45 μm or less (350 mesh) ”in the same manner as in Example 1. Thus, a crosslinked polymer (A0-6) was obtained. The volume average particle diameter of the crosslinked polymer (A0-6) was 30 μm.
Next, a granular treated material (X-6) was obtained in the same manner as in Example 1.

<Example 7>
In Example 6, the amount of trimethylolpropane triacrylate added “0.3 g (0.1% acrylic acid)” was changed to “0.15 g (0.05% acrylic acid)” and pentaerythritol triallyl ether was added. In the same manner as in Production Example 6, except that the addition amount “0.15 g (0.05% acrylic acid)” was changed to “0.12 g (0.04% acrylic acid)”, a crosslinked polymer ( A0-7) was obtained. The volume average particle diameter of the crosslinked polymer (A0-7) was 30 μm.
Next, a granular treated material (X-7) was obtained in the same manner as in Example 1.

<Example 8>
In Example 1, except that the addition amount of “1.35 g (0.45% acrylic acid)” of trimethylolpropane triacrylate was changed to “9.0 g (3.0% acrylic acid)”. In the same manner as in Example 1, a crosslinked polymer (A0-8) was obtained. The volume average particle diameter of the crosslinked polymer (A0-8) was 300 μm.
Next, a granular treated material (X-8) was obtained in the same manner as in Example 1.

<Examples 9 and 10>
In Example 1, except having followed Table 1, it carried out similarly to Example 1, and obtained each granular processing material (X-9) and (X-10).
In addition, (B0) is a commercially available cellulose nanofiber [number average fiber diameter 1 nm, average aspect ratio 200] (B0-2), a commercially available cellulose nanofiber [number average fiber diameter 200 nm, average aspect ratio 50] (B0− 3) was used.

<Examples 11 and 12>
In Example 1, except having followed Table 1, it carried out similarly to Example 1, and obtained each granular processing material (X-11) and (X-12).

<Comparative Example 1>
A commercially available carboxymethyl cellulose (CMC2450, manufactured by Daicel Chemical Industries, Ltd.) (ratio A-1) was used as it was to obtain a granular processing material (ratio X-1) for comparison.

  About the obtained processing material (X), the absorption characteristic, the cohesiveness after absorption, and the intensity | strength of the aggregate were measured with the following method, and the result was described in Table 1.

<Absorption characteristics: Absorption rate>
400 g of the treated material (X) was placed in a beaker (capacity 1 L) and the surface was leveled. 50 mL of physiological saline was taken into a 50 mL disposable syringe (manufactured by Terumo Corp.), and discharged from the height of about 2 cm toward the center of the surface of the treatment material in the beaker over 5 seconds.
The time until the physiological saline was completely absorbed was measured visually to obtain absorption characteristics. A smaller value means better absorption characteristics.
The physiological saline was prepared by uniformly dissolving 180.0 parts of salt in 19820.0 parts of ion-exchanged water.

<Unity>
In the measurement of absorption characteristics, agglomerates generated by absorption of physiological saline solution were scooped with a spatula 7 minutes after the physiological saline was completely absorbed, and the maximum length of the aggregates having a maximum length of 39 mm or more. The maximum length was measured and set as unity. The smaller this value is 39 mm or more, the better the unity. When the maximum length of the lump is less than 39 mm, it means that lump is hardly generated and the cohesiveness is poor.

<Strength of aggregate>
The agglomerates used in the test for cohesiveness were manually moved up and down according to JIS A1102: 2014 Aggregate Screening Test Method using a metal mesh screen with a nominal opening of 25 mm specified in JIS Z8801-1. And screen by adding horizontal movement. The residual ratio of the aggregate remaining on the sieve after sieving was calculated by Equation (1) and used as an index of the strength of the aggregate. The higher the residual rate of the aggregate, the higher the strength of the aggregate.

[Residual ratio of aggregate (% by weight)] = (weight of aggregate remaining on sieve after shaking) ÷ (weight of aggregate before shaking) × 100 (1)

  The granular treatment material obtained by the production method of the present invention absorbs an aqueous solution quickly, easily aggregates particles after absorption, and the formed aggregate has high strength.

  The granular treatment material of the present invention is suitable for various absorption uses, particularly for animal excrement and water-containing soil treatment, and absorbs excrement such as pets and aqueous solution quickly, and excrement and moisture on the surface of the treatment material. In addition to no leaching, the cohesiveness after absorption of the aqueous solution is good, and the strength of the formed aggregate is high. Therefore, it is excellent in handleability at the time of processing, and is useful as a processing material for animal excrement such as cat sand or a water-containing soil processing material.

Claims (5)

Crosslinked polymer (A) containing water-soluble vinyl monomer (a1) and / or vinyl monomer (a2) which becomes (a1) by hydrolysis and crosslinking agent (c) as constituent monomers, and cellulose nanofiber (B0) And the manufacturing method of the granular processing material (X) containing water-insoluble base materials (B) other than said (B0), Comprising: The manufacturing method which has the following process (1).
Step (1): The water-containing gel of the crosslinked polymer (A) and the cellulose nanofiber (B0) are kneaded.   The weight ratio [(B0) / (A)] of the cellulose nanofiber (B0) and the crosslinked polymer (A) in the granular treatment material (X) is 0.1 / 99.9 to 20/80. 1. The production method according to 1.   The production method according to claim 1 or 2, wherein the cellulose nanofiber (B0) has a number average fiber diameter of 1 to 200 nm.   The manufacturing method according to any one of claims 1 to 3, wherein a weight ratio of (c) is 0.05 to 2% by weight with respect to a total weight of (a1) and (a2).   The method according to any one of claims 1 to 4, wherein (c) is at least one selected from the group consisting of (meth) acrylic acid esters, (meth) acrylic acid amides and polyvalent epoxides.