JP2813224B2 - Swellable oil absorber - Google Patents

Description

The present invention relates to a swellable oil absorbing agent. For more information,
The present invention relates to a swellable oil absorbing agent which efficiently absorbs and swells a large amount of oil with respect to a wide variety of oils including edible oils, and has remarkably improved oil absorbing performance at low temperatures.

(Prior Art) In recent years, recovery of oil spilled to the sea and oil in wastewater has become a major problem in environmental conservation. Further, there is a strong demand for a simple treatment method for small-scale waste oil discarded in homes and factories and for leakage of machine oil and the like in factories.

As one of the most effective means of collecting oil from spilled oil or wastewater or treating waste oil or oil leakage, a method of absorbing oil using an oil absorbing agent and then performing incineration or other post-treatment has been used. Have been. Examples of such oil absorbing agents include natural plant oil absorbing agents such as rice husk, straw, pulp, peat, and cotton; inorganic oil absorbing agents obtained by subjecting inorganic porous powders such as lime, silica, and pearlite to water repellent treatment; Polypropylene fiber,
Synthetic fiber-based oil absorbing agents such as polystyrene fiber and polyethylene fiber; and foamed resin-based oil absorbing agents such as foamed polyurethane foam have been commercially available.

However, many of these conventional products do not provide a satisfactory oil absorption amount, and the oil absorption mechanism absorbs and holds oil in pores or pores existing in the material. There were drawbacks. That is, the conventional oil absorbing agent hardly changes in volume due to oil absorption, becomes extremely bulky, and has disadvantages in storage and handling. Poor oil retention after oil absorption, especially natural plant-based, synthetic fiber-based and foamed resin-based oil-absorbing agents re-release oil that was easily absorbed by slight external pressure, making post-treatment extremely complicated. It is.
These oil absorbing agents are generally subjected to a water-repellent treatment. However, if they are used in an oil-water mixed system for a long period of time, they will penetrate into the voids of water and the oil absorbing ability will be reduced. Although oil absorption from the oil-water suspension state is possible to some extent, there is a problem that the oil dissolved in water cannot be absorbed essentially.

As means for solving these problems, there have been reported some synthetic resin-based oil-absorbing agents which absorb and swell oil in certain polymers. For example, a copolymer of t-butylstyrene / divinylbenzene (Japanese Patent Laid-Open No.
No. 081), a crosslinked polymer of t-butyl methacrylate and / or neopentyl methacrylate (JP-A-5050 / 1990).
No. -15882), a crosslinked polymer of menthyl methacrylate (JP-A-50-59486), polynorbornene rubber (for example, Nosorex AP manufactured by CdF) and the like.

However, the t-butyl methacrylate and / or neopentyl methacrylate crosslinked polymer shows a certain amount of oil absorption for aromatic hydrocarbon-based low-boiling oils such as benzene, but shows a certain amount of oil absorption for aliphatic hydrocarbon-based oils. As a result, a satisfactory oil absorption was not obtained. Also, t-
Butyl styrene / divinylbenzene copolymer, crosslinked polymer of menthyl methacrylate, and polynorbornene rubber show a certain amount of oil absorption to low-boiling aromatic or aliphatic hydrocarbon oils, but fatty acid ester oils It was inferior in polar oily properties such as oils, fatty acids and higher alcohols, and in oil absorption performance for highly viscous oils. Therefore, these synthetic resin-based oil-absorbing agents are limited in applicable fields of application, and cannot be applied particularly to edible oil processing fields. In addition, many of these oil absorbing agents have a low oil absorbing speed, and particularly have a significantly reduced or lost oil absorbing performance at low temperatures.
It has a drawback that it is difficult to exert its effect when used in cold regions.

(Problems to be Solved by the Invention) The present invention is to solve the above-mentioned problems of the conventional oil absorbing agent.

That is, an object of the present invention is to have excellent oil absorption capacity, oil absorption speed and oil retention ability after oil absorption for a wide variety of oils including fatty acid esters such as edible oils, and furthermore, the oil absorption performance is lowered even at low temperatures. An object of the present invention is to provide a swellable oil absorbing agent which does not have any problem.

(Means and Actions for Solving the Problems) As a result of earnest studies, the present inventors have found that a crosslinked polymer of a specific (meth) acrylate monomer is extremely effective in achieving the above object. And completed the present invention.

In other words, the present invention relates to a monomer (A) having one polymerizable unsaturated group in a molecule containing a (meth) acrylate of a monohydric aliphatic alcohol having 10 to 16 carbon atoms as a main component.
9.999% by weight and 0.001 to 10% by weight of a crosslinkable monomer (B) having at least two polymerizable unsaturated groups in the molecule
(However, the sum of the monomers (A) and (B) is 100% by weight.) The present invention relates to a swellable oil absorbing agent comprising a crosslinked polymer (I) obtained by polymerizing a monomer component comprising:

The (meth) acrylate constituting the main component of the monomer (A) having one polymerizable unsaturated group in the molecule used in the present invention has a general formula: (However, in the formula, R ¹ is a hydrogen or methyl group, and R ² is
To 16 aliphatic hydrocarbon groups. ), Carbon number
It is a (meth) acrylate of a 10-16 monohydric aliphatic alcohol, and the number of carbon atoms of the aliphatic hydrocarbon group in the (meth) acrylate must be in the range of 10-16. If the carbon number is less than 10, only a crosslinked polymer having insufficient oil absorption performance can be obtained. The aliphatic hydrocarbon group has 16 carbon atoms.
With a larger (meth) acrylate, only a crosslinked polymer having extremely low oil absorption performance at room temperature can be obtained because of high crystallinity between side chains.

Examples of the (meth) acrylate of a monohydric aliphatic alcohol having 10 to 16 carbon atoms include decyl (meth) acrylate, dodecyl (meth) acrylate, tetradecyl (meth) acrylate, and hexadecyl (meth) acrylate. One or more of these can be used.

The amount of the monohydric aliphatic alcohol having 10 to 16 carbon atoms used in the monomer (A) of the (meth) acrylate is such that the (meth) acrylate is a main component of the monomer (A), that is, 50% by weight. %. When the use ratio of the (meth) acrylate in the monomer (A) is less than 50% by weight, the obtained crosslinked polymer may have poor oil absorption performance, particularly at low temperatures, and can absorb a polar oil or a highly viscous oil. Be impaired.

Therefore, in the present invention, it is necessary that the monomer (A) contains 50% by weight or more of the (meth) acrylate represented by the above general formula, but the monomer (A) contains 50% by weight or less of the (meth) acrylate. A monomer having one polymerizable unsaturated group may be contained in a molecule other than the (meth) acrylate in proportion.

Examples of such a monomer (A) which can be mixed and used with the (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl. (Meth) acrylates of monohydric aliphatic alcohols having 9 or less carbon atoms such as (meth) acrylate and n-octyl (meth) acrylate; and carbon number such as octadecyl (meth) acrylate and behenyl (meth) acrylate
(Meth) acrylates of 17 or more monohydric aliphatic alcohols; (meth) acrylates of cycloaliphatic alcohols such as cyclohexyl (meth) acrylate and menthyl (meth) acrylate, phenyl (meth) acrylate,
Phenol (meth) acrylates such as octylphenyl (meth) acrylate; dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth)
Aminoalkyl (meth) acrylates such as acrylate; (meth) having a polyoxyethylene chain such as polyethylene glycol mono (meth) acrylate and methoxypolyethylene glycol mono (meth) acrylate
Acrylates; (meth) acrylamides, (meth) acrylamides such as N-methylol (meth) acrylamide, dimethylaminoethyl (meth) acrylamide; polyolefins such as ethylene and propylene; styrene, α-methylstyrene, t-butylstyrene Aromatic vinyl compounds such as vinyl chloride, vinyl acetate, acrylonitrile, (meth) acrylic acid and the like, and one or more of these can be used.

The crosslinkable monomer (B) used in the present invention has at least two polymerizable unsaturated groups in the molecule and acts as a crosslinking agent.

Examples of such a crosslinkable monomer (B) include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polyethylene glycol polypropylene glycol di (meth) acrylate, and polypropylene glycol. Di (meth) acrylate, 1,3
Butylene glycol di (meth) acrylate, N, N-propylene bisacrylamide, diacrylamide dimethyl ether, N, N-methylene bisacrylamide, glycerol di (meth) acrylate, neopentyl glycerol di (meth) acrylate, 1,6 hexanediol di Alkylene oxide of (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolpropanetotetra (meth) acrylate, polyhydric alcohol (for example, glycerin, neopentyl glycol, trimethylolpropane, trimethylolethane or tetramethylolmethane) Polyfunctional (meth) obtained by esterification of adduct with (meth) acrylic acid
Examples thereof include acrylate and divinylbenzene, and one or more of these can be used.

The ratio of the monomers (A) and (B) in the monomer component used in producing the crosslinked polymer (I) is based on the total amount of the monomers (A) and (B). Monomer (A)
The range is from 90 to 99.999% by weight, and the content of the monomer (B) is from 0.001 to 10% by weight. When the amount of the monomer (A) exceeds 99.999% by weight or the amount of the crosslinkable monomer (B) is less than 0.001% by weight, the solubility of the obtained crosslinked polymer in oil increases, and Oil retention performance deteriorates due to fluidity. If the amount of the crosslinkable monomer (B) exceeds 10% by weight, the crosslink density of the resulting crosslinked polymer becomes too high, and the swelling property of the crosslinked polymer upon contact with oil is reduced. Oil cannot be absorbed.

In order to produce the crosslinked polymer (I), the monomer component may be copolymerized using a polymerization initiator. Copolymerization can be carried out by a known method such as bulk polymerization or suspension polymerization.However, it is easy to remove the reaction heat during the polymerization, and it has high oil absorption performance such as oil absorption rate and is easy to handle. It is desirable to carry out by suspension polymerization since coalescence can be obtained.

Suspension polymerization can be performed by a known method. For example, the monomer component may be suspended in water using an emulsifier having a high HLB value or a protective colloid agent such as polyvinyl alcohol and hydroxymethyl cellulose, and polymerized in the presence of an oil-soluble polymerization initiator. As the polymerization initiator,
Organic peroxides such as, for example, benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide;
An azo compound such as azobisisobutyronitrile and azobisdimethylvaleronitrile can be used, and the temperature during polymerization is preferably in the range of 50 to 150 ° C.

According to the suspension polymerization, the crosslinked polymer (I) usually has a particle size of
It is obtained as an aqueous suspension of fine-grained resin of about 10 to 1000μ, and the suspension may be used as it is as the swellable oil absorbing agent of the present invention, or used after dehydration by a method such as filtration or drying. You can also.

The swellable oil absorbing agent of the present invention comprising the crosslinked polymer (I) thus obtained can be used in various forms. For example, the swellable oil-absorbing agent of the present invention may be added or sprayed to an oil-water mixture system such as an oil-water suspension or an aqueous solution in which an oil component is dissolved or oil, or may be filled in an open container such as a cylindrical tube. May be used. Further, the swellable oil-absorbing agent of the present invention may be used by adhering to or incorporating into a fibrous material or filling a cloth bag or package.

Further, the swellable oil absorbing agent of the present invention is, for example, used in combination with conventionally known oil absorbing agents and fillers such as rice husk, straw, pulp, cotton, porous lime, porous silica, porous pearlite, and polypropylene fiber. It can also be used.

(Effect of the Invention) The swellable oil absorbing agent of the present invention is composed of a (meth) acrylate-based cross-linked polymer having a large number of specific long-chain aliphatic hydrocarbon groups effective for exhibiting oil absorbing performance in the molecule. With little absorption of water, not only aromatic hydrocarbons, aliphatic hydrocarbon oils, but also fatty acid ester oils, higher fatty acids, higher alcohols, ethers, etc. It absorbs oil promptly, has little effect on oil absorption performance due to temperature change, and can maintain high absorption performance even at low temperatures.

Therefore, the swellable oil absorbing agent of the present invention is effective in recovering oil spilled at sea, recovering floating oil, recovering oil in wastewater even under low-temperature conditions, emulsion breakers, oil leakage treatment agents, edible waste oil treatment agents, machinery It can be applied to a very wide range of applications such as waste oil treatment agents, household or industrial oil wipers, chemical wipes, oil leak sensors, oil sealants, various oil retention agents, and the like. Further, the swellable oil absorbing agent of the present invention,
Since it absorbs and retains a wide range of oils, it can be used as a sustained-release base material for various fragrances, insecticides, fish collectors, etc., and can greatly contribute to industrial development.

(Examples) Next, the swellable oil absorbing agent of the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Unless otherwise specified, parts are by weight.

Example 1 In a 500 ml flask equipped with a thermometer, a stirrer, a gas inlet tube and a reflux condenser, 2 parts of completely saponified polyvinyl alcohol (polymerization degree 1500) and partially saponified polyvinyl alcohol (polymerization degree 1000, saponification rate 80%) ) 0.08 part was dissolved in 300 parts of water and charged, the atmosphere in the flask was replaced with nitrogen under stirring, and the flask was heated to 40 ° C under a nitrogen stream. Thereafter, 99.823 parts of dodecyl acrylate as the monomer (A), 0.177 parts of ethylene glycol diacrylate (based on dodecyl acrylate 0.25 mol%) as the crosslinkable monomer (B), and 0.5 parts of azobisdimethyl valeronitrile as the polymerization initiator. The solution was added to the flask all at once, and stirred vigorously at 400 rpm. Next, the temperature in the flask was raised to 70 ° C., and the polymerization reaction was carried out at the same temperature for 2 hours. Thereafter, the temperature in the flask was further raised to 80 ° C. and maintained for 2 hours to complete the polymerization. After completion of the polymerization, the particulate crosslinked polymer is separated by filtration, washed with water, and then dried at 60 ° C to obtain a particle size of 100 to 1000 μm.
m of the swellable oil absorbing agent (1) was obtained.

Example 2 In a 500 ml flask equipped with a thermometer, a stirrer, a gas inlet tube and a reflux condenser, 2 parts of completely saponified polyvinyl alcohol (polymerization degree 1500) and partially saponified polyvinyl alcohol (polymerization degree 1000, saponification rate 80%) ) 0.08 part was dissolved in 300 parts of water and charged, the atmosphere in the flask was replaced with nitrogen under stirring, and the flask was heated to 40 ° C under a nitrogen stream. Thereafter, a solution comprising 99.895 parts of hexadecyl methacrylate as the monomer (A), 0.105 parts of divinylbenzene (based on 0.25 mol% of hexadecyl methacrylate) as the crosslinkable monomer (B), and 0.5 parts of benzoyl peroxide as the polymerization initiator. Was added to the flask at one time, and the mixture was vigorously stirred at 400 rpm. Next, the temperature in the flask was raised to 80 ° C., and the polymerization reaction was carried out at the same temperature for 2 hours.
The temperature was raised to 90 ° C. and maintained for 2 hours to complete the polymerization. After the polymerization is completed, the particulate crosslinked polymer is filtered off, washed with water, and then cooled to 60 ° C.
To obtain a swellable oil absorbing agent (2) having a particle size of 100 to 1000 μm.

Example 3 In Example 2, 99.734 parts of decyl acrylate was used as the monomer (A), and 0.266 parts of 1,6 hexanediol diacrylate (0.25 mol% based on decyl acrylate) was used as the crosslinkable monomer (B) instead. A swellable oil-absorbing agent (3) was obtained in the same manner as in Example 2, except for the fact that

Example 4 In Example 1, the amount of dodecyl acrylate was changed to 92.3.
08 parts, and 7.692 parts of polypropylene glycol diacrylate (molecular weight 4000) (based on dodecyl acrylate 0.5 mol%) as the crosslinkable monomer (B),
A swellable oil absorbing agent (4) was obtained in the same manner as in Example 1.

Example 5 In Example 2, 59.908 parts of hexadecyl methacrylate and butyl methacrylate 3 were used as monomers (A).
9.938 parts, divinylbenzene as crosslinkable monomer (B)
A swellable oil absorbing agent (5) was obtained in the same manner as in Example 2, except that 0.154 part (based on monomer (A) 0.25 mol%) was used instead.

Comparative Example 1 In place of 99.823 parts of dodecyl acrylate in Example 1, 44.863 parts of dodecyl acrylate and 54.833 of styrene
Parts to reduce the amount of ethylene glycol diacrylate to 0.30
A comparative oil absorbing agent (1) was obtained in the same manner as in Example 1, except that the amount was changed to 4 parts (based on dodecyl acrylate + 0.25 mol% of styrene).

Comparative Example 2 In Example 1, instead of 99.823 parts of dodecyl acrylate, 44.848 parts of dodecyl acrylate and 1 part of acrylic acid
Using 4.949 parts and methyl methacrylate 39.866 parts,
A comparative oil absorbing agent (2) was obtained in the same manner as in Example 1, except that the amount of ethylene glycol diacrylate was changed to 0.337 parts (based on dodecyl acrylate + acrylic acid + methyl methacrylate 0.25 mol%).

Comparative Example 3 In Example 1, 99.770 parts of 2-ethylhexyl acrylate was used in place of 99.823 parts of dodecyl acrylate, and the amount of ethylene glycol diacrylate was changed to 0.230 parts (based on 0.25 mol% of 2-ethylhexyl acrylate). Comparative oil absorbing agent (3) was obtained in the same manner as in Example 1.

Comparative Example 4 In the same manner as in Example 1, except that 99.869 parts of octadecyl acrylate was used instead of 99.823 parts of dodecyl acrylate, and the amount of ethylene glycol diacrylate was changed to 0.131 parts (based on 0.25 mol% of octadecyl acrylate). As a result, a comparative oil absorbing agent (4) was obtained.

Comparative Example 5 In Example 2, 99.8 hexadecyl methacrylate was used.
Instead of 95 parts, 99.797 parts of t-butylstyrene were used, and the amount of divinylbenzene was 0.203 parts (based on t-butylstyrene).
Comparative oil absorbing agent (5) was obtained in the same manner as in Example 2 except that the composition was changed to 0.25 mol%).

Comparative Example 6 In Example 2, 99.8 hexadecyl methacrylate was used.
Example 2 was repeated except that 99.772 parts of t-butyl methacrylate was used instead of 95 parts, and the amount of divinylbenzene was changed to 0.228 parts (based on 0.25 mol% of t-butyl methacrylate).
Comparative oil-absorbing agent (6) was obtained in the same manner as described above.

Comparative Example 7 In Example 2, 99.8 hexadecyl methacrylate was used.
Comparative oil-absorbing agent was prepared in the same manner as in Example 2 except that 99.780 parts of menthyl methacrylate was used instead of 95 parts, and 0.220 part of ethylene glycol dimethacrylate (0.25 mol% based on menthyl methacrylate) was used instead of 0.105 part of divinylbenzene. (7) was obtained.

Example 6 The swellable oil absorbing agents (1) obtained in Examples 1 to 5
(5) Comparative oil-absorbing agents (1) obtained in Comparative Examples 1 to 7
Using each of (7) and polynorbornene rubber as an oil absorbing agent, the oil absorbing performance and the water absorbing property were evaluated by the following methods.

<Evaluation method> 5 g of the oil-absorbing agent sample was immersed in various oils or water shown in Table 1 at 20 ° C, and collected by filtration on a wire mesh after 30 minutes and 24 hours. Then, after leaving the sample on a wire mesh for 30 minutes to allow the oil or water not held by the sample to flow down sufficiently,
The weight of the swelled sample was measured, and the absorption rate (oil absorption rate or water absorption rate) was calculated according to the following equation.

Absorbance (g / g) = (weight of swollen sample−weight of sample before immersion) / weight of sample before immersion The evaluation results are shown in Table 1.

As is clear from Table 1, the swellable oil absorbing agent of the present invention comprises:
Large amounts of oil can be absorbed in a very short time for a wide variety of oils.

Example 7 Swellable oil absorbing agents (1) obtained in Examples 1 to 5
(5) Comparative oil-absorbing agents (1) obtained in Comparative Examples 1 to 7
(7) 5 g each of polynorbornene rubber and 5 ° C
And immersed in toluene and n-decane under the condition of -10 ° C, and after 24 hours, collected by filtration on a wire mesh under the same temperature condition. Then, the sample was left on a wire mesh for 30 minutes under the same temperature condition to allow the oil not retained by the sample to flow sufficiently, then the weight of the swollen sample was measured, and the absorption was calculated according to the same formula as in Example 6. did.

 The evaluation results are shown in Table 2.

Table 2 shows that the swellable oil absorbing agent of the present invention is excellent in oil absorbing performance at low temperatures.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takayoshi Goto 14-1 Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Kawasaki Research Laboratory of Nippon Shokubai Chemical Industry Co., Ltd. (56) References JP-A-61-164606 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) C09K 3/32

Claims (2)

(57) [Claims] 1. A monomer having one polymerizable unsaturated group (A) in a molecule containing a (meth) acrylate of a monohydric aliphatic alcohol having 10 to 16 carbon atoms as a main component, 90 to 99.999% by weight. And 0.001 to 10% by weight of a crosslinkable monomer (B) having at least two polymerizable unsaturated groups in the molecule (provided that the total of the monomers (A) and (B) is 100% by weight). )
A swellable oil absorbing agent comprising a crosslinked polymer (I) obtained by polymerizing a monomer component comprising: 2. The monomer (A) comprising a monohydric aliphatic alcohol (meth) acrylate having 10 to 16 carbon atoms in an amount of 50% by weight or more in the monomer (A). Item 4. The swellable oil absorbing agent according to Item 1.