JPS62149335A - Water absorbent - Google Patents

Abstract

PURPOSE:To obtain the titled water absorbent which can be uniformly dispersed in rubber, etc., and capable of giving water-expanded rubber having a high expansion factor by allowing water absorptive resin powder having a carboxyl to react with an alcohol having a >=5 C hydrophobic group, and making the surface of the water absorptive resin powder hydrophobic. CONSTITUTION:About 0.001-10pts.wt. alcohol such as heptanol having a >=5 C hydrophobic group is mixed with 100pts.wt. water absorptive resin such as 2-sulfoethyl (meth)acrylate having a carboxyl, reaction is carried out at >=90 deg.C, and the surface of the water absorptive resin powder is made hydrophobic. The obtained water absorbent can be uniformly dispersed when kneaded with rubber or a thermoplastic resin, and water-expanded rubber or a water-expanded resin having an excellent performance as a water stopping agent, a sealing material, etc., can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field 1] The present invention relates to a water-absorbing agent.More specifically,
When kneaded with rubber and/or thermoplastic resin, it is uniformly dispersed, and the rubber and/or thermoplastic resin absorbs an aqueous substance and expands to a high degree.1! There is information about water absorbing agents.

[Prior Art] Conventionally, rubber Jt J: which expands by absorbing aqueous substances: and/or thermoplastic resin 1. L1 water stop material, ceiling shrine.

Used for rose 1 coating and caulking 4AW.

This water-swellable rubber or water-swellable resin is a water-absorbing resin with rubber J3 and/or thermoplastic V! It is kneaded into resin and expands by 1 q after absorbing an aqueous substance.

The water-absorbing resin that can be used is, for example, sulfoalkylene 1:(meth)acrylate 1-(meth)acrylic acid-based compound [base cross-linked body (patent application 1983-157!i)]
30 g), hydrolyzate of starch-acrylic 21-lyl graph 1/small combination《endurance 1t1 49-43:1
No. 95》, Neutralized product of Denbun-acrylic liquor graph I-tt7 combination (JP-A-51-1254081'j), Compound of vinyl acetate-acrylic acid ester copolymer (1
! J MaSho 52-14G89), hydrolyzate of acrylonitrile copolymer or acrylamide co-jp polymer (
(Japanese Patent Publication No. 53-15959), or crosslinked products thereof, self-crosslinked +4 type polyacrylic acids I~Rium obtained by reverse phase suspension polymerization (Japanese Patent Publication No. 53-40389r3)
), partially neutralized polyacrylic acid crosslinked product (1) Kaimei 55
-843043''3) etc. are known.

[Problems to be Solved by the Invention] However, since these water-absorbing resins have strong hydrophilicity, they are difficult to disperse in rubber/thermoplastic resins that are inherently hydrophobic.

Therefore, water-swellable rubber or water-swellable rubber 1111 in which a conventional water-absorbing resin is dispersed in a rubber/thermoplastic resin has insufficient dispersion of the water-absorbing resin. The original water swelling ability of the water absorbent resin could not be brought out, and the swelling rate was insufficient.

The present invention solves the above problems and makes rubber and thermoplastic 1
1 Dispersion in resin (JI rigure, high expansion 11) Add 9 parts of dense water-swellable rubber or water-swellable resin to 1ν and 1 part of liquid agent! After extensive research, we have finally completed the present invention. .

[R-stage action to solve the problem] The invention is based on the invention by adding an alcohol containing a hydrophobic group having 5 or more carbon atoms to a water-absorbing resin powder containing a carbo-1:sil group (T). mix, 9
This is related to the water-absorbing agent, which is produced by heating the water-absorbing resin powder with a hot stone at 0°C or higher to cause the water-absorbing resin powder to react with the alcohol, thereby making the surface of the water-absorbing resin powder hydrophobic. be.

The water-absorbing resin used in the present invention as J3 is carbonyl 1
- It is necessary that the syl group be on the right side. This J: eel water-absorbing resin includes, for example, sulfonic acid 1°7-containing An
body-(meth)acrylic acid-(meth)acrylic acid alkali metal j-copolymerized crosslinker, starch-acrylonitrile graft polymer hydrolyzate 1, starch-acrylic acid graph 1-polymer partially neutralized product, Saponified product of Fi1M vinyl-acrylic acid Nisder copolymer, hydrolyzate of acrylonitrile copolymer b L < l:L acrylamide copolymer, or crosslinked products thereof, partially neutralized polyacrylic acid, polyacrylic acid moiety One or more types of neutralized crosslinked products can be used. Among these, it is preferable that the string has a crosslinked structure, but it is also possible to use a string that does not have a crosslinked structure.

Among these water-absorbing resins, preferred in the present invention are the water-absorbing resins shown in the following items 0 to 0, for example.

■ 2-sulfoethyl (meth)acryle-1-,3-sulfobyl 1-copyl (meth)acrylate, 1-sulbobrovacy 2-yl (meth)acrylate, 2-acrylamido-2-methylpropanesulfone resistant, acrylamitomecnesulfonic acid , vinyl sulfonic acid.

Subrensulfone M'3 seems to be those alkaline products.
+i (one or more types of sulfonic acid jJ-containing n-polymerized 11 monomers such as Ij) (r) 10 to 9
0 mol%, acrylic acid and/: 1: or methacrylic M
(11) 1 to 50 mol%, and other single substances such as (meth)acrylate, (meth)acrylamide, etc. (■) 0 to 50 mol% (However, (I>, (ff)
, and (III) components is 100 mol%. ) is subjected to aqueous solution polymerization or reverse phase suspension polymerization in the presence of a crosslinking agent, if necessary, to form a water-containing polymer, which is then dried and subjected to T'iR.

■ Acrylic 1% li j consisting of 1 to 50 mol% of acrylic M and 50 to 99 mol% of alkali metal salt of acrylic acid.
! ! A water-absorbing resin obtained by drying a water-containing polymer formed by aqueous solution polymerization or reverse phase suspension polymerization of a type Ill Er body, if necessary in the presence of a crosslinking agent.

■ Cyanide of a copolymer of vinylnisdel and edylenic unsaturated carboxylic acid or derivatives thereof.

■ Starch rice/or sylulose, carbo: r
sil 3 (< to the right J or 1, L to hydrolyze J, ricacybo-1: a single monomer, J3, and optionally a crosslinking agent to generate a sil group, combined in an aqueous medium. , if necessary, J: A water-absorbing resin that has undergone tl"1 by further hydrolysis.

■ α-A reflex J: I consisting of a vinyl compound
! Y J, Reaction of an alkaline substance ° C1 to a maleic anhydride-based co-lβ combination consisting of at least 61 types of L1-1 and maleic anhydride, which was produced in a pot, is necessary. A water-absorbing resin obtained by reacting a reaction product with a polyester compound.

There is no particular restriction on the male carbo-1-yl group in the water-absorbing resin, but it is preferable that the carboxyl J1 (carboxyl J1) per 100 g of water absorption (IJ11) is 0.01 equivalents or more (?r[ .

Regarding the shape of the water-absorbing ↑4 resin powder used in the present invention, there are particular limitations, for example, 1! in the reverse phase suspension method.
1 spherical shape, 1 in drum drying! bJ, either in the form of flakes produced by I, or in amorphous shape produced by crushing the resin lump,
stomach.

The alcohol used in the present invention has 5 carbon atoms.
It is necessary to add more hydrophobic groups to the right side.

If an alcohol with one or more hydrophobic groups having less than 5 carbon atoms is used, the surface of the water-absorbing resin powder cannot be made sufficiently hydrophobic, resulting in poor dispersibility in rubber and/or thermoplastic resins. Not improved.

Examples of alcohols having a hydrophobic group having 5 or more carbon atoms used in the present invention include pentanols such as 1-pentanol, 2-pentanol, and 3-pentanol; Linoles, heptatools, 'A-couunols, decanols 1. Tradecanols, tradecanols 1. Hekylidecanols.

Octadecanol: 11 linoles, vinyl: 1
linoles, Tetler 11J-nols, 1-nacolinols, sorbitan monospheres 1., sorbitan 1-listearate, sorbitan L-nolaure I~.

Examples include sorbitan monooleate-1-, AOGQD (α-olefin glycol, manufactured by Guihiru Kagaku Kogyo), and the like. Six types of these can be used in one type, or two or more types can be used in combination.

The alcohol used in the present invention as a hydrophobic group having 5 or more carbon atoms is 0.001 to 10 parts per 100 parts of the water-absorbing resin powder. The 15th circle of the n-th part is preferable. If it is less than 0°001, sufficient surface hydrophobicity of the water-absorbing resin powder cannot be achieved, and using a suspension exceeding 10 parts is uneconomical.

In the present invention, the alcohol having a hydrophobic group having 5 or more carbon atoms used in the present invention may be mixed alone with the water-absorbing resin powder and then heat-treated. To promote uniform dispersion and near-surface penetration,
It is preferable to use an organic solvent in combination.1. The organic solvent is not limited to 1J as long as it can uniformly dissolve the hydrophobic alcohol having 5 or more carbon atoms (/lj, 4) and does not affect the performance of the water absorbent resin. Examples of such right iE1 wf'R include methyl alcohol, ethyl alcohol, n-propyl alcohol,
Lower alcohols with low boiling points such as 1so-propyl alcohol, n-butyl alcohol, 1so-butyl alcohol, [-butyl alcohol; Ketones such as acetone, methane, etc.; n-benkune, n-hekilene, n-Δ Aliphatic hydrocarbons such as Kukun; Alicyclic hydrocarbons such as Nijichlorohekirin; Aromatic hydrocarbons such as Benvin, Tor], N; Ethers such as Niji A° Kirin, Te1-Rahydrofuran; Examples include nitrous compounds such as acid Idel.

What is the maximum size of the organic solvent used in the present invention depending on the type and particle size of the water-absorbing resin powder? Shinaru, but
Water-absorbing resin) 0.01-3 per 100 parts
0 car suspension weight is preferable. The amount of organic solvent is 0.01i11!
Below the hanging part, the effect of adding the organic solvent was not observed,
In addition, in the case of rii exceeding 30 ω parts, heat treatment is performed at 11.
It takes 1 minute.

In the present invention, an alkyl having a hydrophobic f'l group having 5 or more carbon atoms in a water-absorbing resin powder:
In order to mix the mixture of the organic solvent and the organic solvent described in 11, it is necessary to add water ('l) to the resin powder with a hydrophobic fII having 5 or more carbon atoms.
It is common to spray, drop, or mix an alcohol or a mixture of the alcohol and an organic solvent. 1 history for mixing As a mixer, do you want to mix it evenly? 31. It is preferable to have a large Fa resultant force. However, a normal mixer or kneader can be used.

For example, cylindrical "! mixer, knee Φ round-shaped mixer, V-type mixer, ribbon-type mixer, scree L-type) one-piece mixer.

Fluidization type mixer 2 rotating disk type mixer, air flow type mixer, double arm type 1 boiler, Incinal Mixer, Nra! ~1.
111i1 pair, [)-Rumikiri-1, to Scrikou1
! Extrusion is etc. .

At the end of the water absorption fII' fal fat, there is a hydrophobicity on the carbon number 51.
1-R and right Bl! Polymerize the mixture (with rfj medium) and make jq
To heat the mixed mixture (, 1, keep warm (, 1)
1) A heating furnace can be used.

If there is one row, '):? ＋ '、'＋'! ] L2 stirring dryer 9 rotation dryer 1 yen a8 drying Zl! lj! Japanese dryer, flow Ω
JFi dryer, thermal dryer, infrared dryer 1,
Heating place 1q! The temperature is 90℃ or higher, preferably 150-2
It is in the range of 50'C. , below 90℃;! At a low temperature of 1 (
Well, since the heat treatment requires a long time, it is not only economical, but also the effect of the present invention can be realized depending on the type of alcohol and the use of the alcohol that has a hydrophobic group having 5 or more carbon atoms. However, the esterification reaction may not proceed to a sufficient degree. When the temperature of the heat treatment is set in the range of 150 to 250°C, it is possible to carry out the Nisdellization reaction in a short period of time without worrying about coloring or deterioration of the water-absorbing resin and without causing the effects of the present invention to be exhibited. However, at high temperatures exceeding 250'C,
Water absorption 1-1 resin) Class F and J: require pouring as thermal deterioration occurs.

['fF, light effect] This J: Ushite 1! The water-absorbing agent of the present invention has a rubber J3 Jζ and/or thermoplastic T11 resin compared to conventionally known water-absorbing T/L resins. Because the water-absorbing agent of the present invention is not uniformly dispersed in the water-absorbing agent, the water-swellable rubber or water-swellable resin using the water-absorbing agent of the present invention has a higher expansion rate than those using conventionally known water-absorbing resins. 18 rate will increase.

Therefore, the water absorbing agent of the present invention is an Eblene-M acid vinyl copolymer, an Eblene-MM vinyl co-n combination, and an Edylene-isobutrene copolymer.

Ejilene-acrylic MP, copolymer, vinyl chloride + fi
Coalescence, polyurethane, polyethylene, boria[1pyrene, borisdyrene, ΔBS resin, polyamide.

Thermoplastic resins such as vinyl acetate, ethylene-brobylene rubber, polybutadiene rubber, polyisoprene rubber, styrene-butadiene rubber, etc. T! Synthetic rubber, acrylonitrile-butazine copolymer rubber, chloroprene rubber, fluororubber, silicon rubber, urethane rubber, polysulfide rubber, acrylic rubber, butyl rubber.

Epic [1] can be kneaded with rubber such as natural rubber and used as a water-swellable rubber or water-swellable resin with excellent water-swellability.

[Example 1] Hereinafter, the present invention will be described in detail with reference to Examples, but the scope of the present invention is limited only to these Examples.
There isn't. J3, unless otherwise specified, parts indicate heavy items.

Reference Example 1 In a 5007 cylindrical L bulk flask, a t3. j 172
．． 8+1 (080 mol), 3,6 acrylic acid (0,0
5T nyl), acrylic acid (-lium IL1g (0,
15 mol), N.

N-medilene pis acrylamide 0.154<1
(0,001 [le) and water 2 (prepare iog, Pal
After replacing the solution with 1 volume of nitrogen to uniformly dissolve the solution, heat to 40°C in a hot water bath and add 1.00% of a 10% aqueous ammonium per171ate solution and 0.5% of a 1% aqueous L-ascorbic acid solution. 11.
! I! Gobunhama 1112 fever, GII'CU 40 minutes later
: '('', 1: )/ Temperature 1σ of the 1, 10 combination system
After confirming that the temperature had begun to drop, the water bath was raised to 90°C and heated for an additional hour. 1', 7 After the water-containing gel of the water-absorbing resin was divided into small pieces, it was dried in a hot air dryer at 150°C.
Dry for an hour, pulverize, sieve with 200 mesh wire mesh, and pass through 200 mesh (hereinafter referred to as water-absorbing resin powder (1
), ) is t! ′? /child.

Reference Example 2 Add 1 drop of CI-1- with a stirrer, reflux condenser, and transfer to a 500-me fourth flask equipped with a nitrogen gas inlet tube:
t = Phosphorus 220 tnfl was charged, 1.8 g of sorbitan monosdare was added and dissolved, and then nitrogen was replaced. Add 1 drop to 1 coat of 2-acrylamide-2-mebrub [1 pansulfonic acid sodium j! 22. ．． 9th (
0,10T nyl), methacrylic acid 4.3g (0,05[
), 10.8 mol of ptrium methacrylate (o, io mol), trimethylol butyl
0.029Go (o, oooi c-le), water 50Q
After adding 0.05 g of potassium persulfate Ix to obtain a uniform aqueous solution, nitrogen gas was blown into the solution to remove I'a cords present in the aqueous solution. Next, add the contents of the dripping port 1 to the above-mentioned four-way flask to avoid dispersion, and while introducing a slight amount of nitrogen gas, set the temperature of the J:m yarn in a hot water bath at 60 to 65.
The polymerization reaction was continued for 3 hours while being maintained at °C. Behind the scenes 11
- To: 1 niline is distilled off under reduced pressure, and the water absorbency (ko 1
The fat hydrogel was dried under reduced pressure at 80°C and then crushed.
Sieve through a 0.00 mesh wire mesh and remove the material that passes through a 200 mesh wire mesh (hereinafter referred to as water-absorbing resin powder (2)).

Reference example 3! The cylindrical shape of i 00 mQ is 2-sulfonide acrylate] thorium salt 121.2Q in a parallel flask.
(0,60 mol), methacrylic acid 4.3 g (0,0
5T-nil), sodium methacrylate 1 (i, 2g
(0,151 nyl), acrylamide 14.20 (
0.20 mol) and 1901J of water (10%, including
Ammonium persulfate aqueous solution 1. Polymerization was carried out in the same manner as in Reference Example 1 using Og and 0.50 of a 1% L-ascorbic acid aqueous solution. 4!7 The water-containing gel of the water-absorbent resin was divided into small pieces, dried at 150°C for -/I n5, and after pulverized,
The material that passed through a 200 mesh wire mesh (hereinafter referred to as water absorbent resin powder (3)) was filtered through a 0 mesh wire mesh.

Reference example 4 Thorium acrylate 7495 mol%, acrylic A! i
257% J3 J, Bitrimethylolb1" Bread I
Reacrylate 43% aqueous solution of acrylic ho Jllll series monoIII from 0.05 to 96 4000
Part, over,'! I acid ammonium [chive 1, o, e part J3 J
: Biar/[MHydrogen 0.2 parts of sodium chloride was mixed with I'1711d at 55-80° C. in a nitrogen atmosphere to give a gel-like water polymer 1i). This gel-like Ω water polymer is
Dry in a hot air dryer (19), crush with a hammer type grinder, sieve through a 200 mesh wire mesh, and remove 200 mesh.
′ water-absorbing resin powder (hereinafter referred to as water-absorbing resin powder (4)).

) is (!1).

Reference example 5 50 parts corn starch, 200 parts water.

Add 1000 parts of Shinol to a stirring bar and nitrogen blowing pipe J3 J
:Pour into a reaction vessel without a hot melon shavings, stir at 50℃ for 1 hour under a nitrogen stream, and then cool to 30℃.
25 parts acrylic acid, 75 parts sodium acrylate,
Add 0.5 parts of methylenebisacrylamide, 0.1 parts of amium persulfate J3 as a polymerization catalyst and 0.1 parts of sodium bisulfite as a promoter, and at 60°C /
When the reaction was allowed to take place for 115 minutes, a white suspension appeared with a concentration of 1:1.
It was done.

Filter this white suspension lTl'a and get 1! The resulting powder was washed with a water-methyl alcohol mixed solution (water to methyl alcohol ratio: 2:10), dried at 60°C under reduced pressure for 3 hours, ground, and sieved through a 200-mesh wire mesh. (
), and the material passing through 200 meshes (hereinafter referred to as water-absorbing resin powder (5)) is 1! '1.

Reference Example 6 U consisting of 60 parts of MM vinyl and 40 parts of methyl acrylate
0.5 part of benzoyl bar A21 lead was added as an initiator to the mixture, and this was mixed into partially saponified polyvinyl.

in 30 parts water containing 3 parts alcohol and 10 parts salt
i! ! T! After suspension polymerization was carried out at 5°C for 6 hours, it was filtered and dried to obtain a C copolymer.The resulting copolymer was saponified, washed, and dried. ) was crushed and classified, and the material that passed through 200 meshes (hereinafter referred to as water-absorbing resin powder (6
). ) is 1-1.

Reference Example 154 parts of physobutylene-maleic anhydride copolymer, 64 parts of sthorium hydroxide J3 and 398 parts of water were mixed, and 90 parts of
A homogeneous aqueous solution was prepared by heating and stirring at ℃ for 2n5 minutes.

Next, add glycerin diglycidyl Able 2 to this aqueous solution.
．． After mixing, the mixture was poured into a vat, and the crosslinking reaction was carried out in a heat-pressure dryer at 110°C. Powder (7)) is 1iI.

Example 1 Water absorbent resin powder (1) prepared in Reference Example 1 100
A mixture of 2 parts of 1-'A tadecanol and 20 parts of 1so-propyl alcohol was added to part C and mixed with a paddle type mixer, and the resulting mixture was continuously heat-treated with a paddle dry V-. The water absorbing agent (1) of the invention is 1!1.
In addition, this paddle dry 1/- average) 1; 1 residue 11.
'1 interval is 25 minutes, paddle dry t/-IJI
The temperature of the water absorbing agent (1) at the 71st point was 190°C.

1! After kneading the water absorbing agent (1) former) part and the ioo part of 1 Bren-acid resistant vinyl copolymer (Evaflex (manufactured by Mical Co., Ltd.) at 11-L for 15 minutes, the mixture was kneaded at 100°C. A test piece that was press-formed into a 1# thick sheet was heated for 1'J.The test piece was soaked in tap water for 24 hours.
11. The ratio (expansion rate) of the volume after immersion to the volume before immersion of the test piece after immersion for 1' was measured.

The results are shown in Table 1.

Comparative Example 1 The water-absorbing resin powder (1) obtained in Reference Example 1 was treated with surface hydrophobization treatment (C) in the same manner as in Example 1.
]-Bufflex@ and the expansion rate of the obtained test piece was measured. The results are shown in Table 1.

Examples 2 to 4 In Reference Examples 2 to 4, 4 parts of 1-octatool was added to 100 parts of 16411f?powder (2) to (4), and IQ was obtained using a double-arm type 1+i'!Japanese machine. After combining, the water absorbing agents (2) to (4) of the present invention were heated by paddle drying in the same manner as in Example 1.

1') I water absorbing agent (2) ~ (/I) 60 parts, Ri I
100 parts of coroprene rubber, 5 parts of zinc white (1'3), 4 parts of magnesilano oxide, 1 part of suderic acid, p, 1 bi-
Diaminosif 1 Nylmethane (anti-aging agent) 2 parts and 2-
2 parts of mercaptobenzobuazole (added Mf accelerator) were kneaded for 15 minutes L/t:: tf2.
150'Cr for 10 minutes L/,/.

A test piece that had been vulcanized and formed into a 1 mm 1' sheet was immersed in tap water and the expansion coefficient was measured. Shown in 1k.

Comparative Examples 2 to 4 Water absorption obtained in Reference Examples 2 to 4 (H fat powder bed (2)・-(
4) was subjected to surface hydrophobization treatment "Example 2 using Zunizo as is"
~/I do the same thing [5↓ to 10 Blend Rubber] 1,
The expansion rate of the test piece was measured.
Shown in the table. .

Examples 5 to 7 1 in Reference Examples 5 to 7! Water absorbent resin powder (5)
(7) Add a mixture of 1 part of 1-toco-1J-nor and 1210 parts of 1-toco-1J-nor to 100 parts, and proceed as in Example 1 (82 cups).

The water absorbing agents (5) to (7) of the present invention are heated to 471
is.

(C1 Example 1 using the water absorbing agents (5) to (7)
and fl jl: [Buffflex ■] 12 drills,
jr,! The expansion coefficient of the test piece was measured. Results first
It is shown in the table.

Comparative Examples 5 to 7 1 in Reference Examples 5 to 7! Water absorbent resin powder (5) ~ (
7) was used as it was without surface hydrophobization treatment, and carried out in 191.
EVAFLEX (■) and H1 were kneaded in the same manner as in 1, and the expansion coefficient of the obtained test piece was measured. The results are shown in Table 1.

Table 1 Table 1 J: Clear h J: Sea urchin, kneaded with the water-absorbing agent of the present invention U 1!7 Water-swellable resin 15 Water-swellable rubber It has excellent water swelling properties compared to b.

Claims (1)

[Claims] 1. Water-absorbing resin powder having a carboxyl group has 5 carbon atoms.
Water absorption obtained by mixing alcohols having the above hydrophobic groups and heating at a temperature of 90°C or higher to react the water-absorbing resin powder with the alcohol to make the surface of the water-absorbing resin powder hydrophobic. agent. 2. The water-absorbing resin having a carboxyl group contains 10 to 90 mol% of one or more monomers (I) selected from sulfonic acid group-containing polymerizable monomers, acrylic acid and/or
or 1 to 50 mol% of methacrylic acid (II) and 0 to 50 mol% of other monomers (III) (however, (I), (
The sum of components II) and (III) is 100 mol%.
Claim 1, which is a water-absorbing resin obtained by drying a hydrous polymer formed by aqueous solution polymerization or reverse phase suspension polymerization of a monomer mixture consisting of ) in the presence of a crosslinking agent if necessary. Water absorbing agent as described in section.