JP2000051691A - Oil adsorbing element and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop an oil adsorbing material capable of still more effectively absorbing and holding oil and capable of being produced more inexpensively than before because an oil adsorbing material having a three-dimensional crosslinked structure is excellent in absorbability as compared with other oil adsorbing material but not yet sufficient and generally high in cost. SOLUTION: A starting material consisting of a base material comprising a polyolefin resin, a bonding and lubricating material comprising starch or the like and a functional material comprising activated carbon is prepared to be mixed in an extrusion moldable state and extruded into a predetermined shape and an extruded molded object comprising steam foam is formed and the extruded molded object is subsequently heat-treated to produce an oil adsorbing material having a water-repellent special three-dimensional structure for absorbing and holding oil therein formed thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-adsorbing material and a method for producing the same, and more particularly to an oil having a special three-dimensional structure by subjecting an extruded product containing natural substances such as starch and activated carbon to processing by heating. The present invention relates to an adsorption material and a method for producing the same.

[0002]

2. Description of the Related Art Today, various fats and oils have entered the end of our lives. Many of them are transported by ships, vehicles, etc., and stored in huge tanks.
If these transportation means or storage means are damaged for some reason and these fats and oils leak into the environment, it is necessary to promptly recover them in order to prevent environmental pollution. An oil-adsorbing material is used in such a case.

[0003] The oil-absorbing materials known in the art can be roughly classified into firstly that they have a very high affinity for oil, so that when they are dropped into oil, the oil is quickly collected and loses the fluidity of the oil itself. Secondly, the resin is heated and dissolved as a gelling material and then cooled to form a loose mesh with long-chain comb-shaped alkyl groups oriented in the oil. Formed and deposited while embracing the oil together. Thirdly, the material has a gradual three-dimensional cross-linking structure inside the material, and is physically separated mainly by affinity with oil, that is, van der Waals force. Oil holding type can be classified into three types.

[0004] However, when the amount of spilled oil is small, or when the spilled area is narrow, the oil adsorbing materials of the first and second forms can be used effectively. Alternatively, when the area from which the oil has flowed out is large, it is difficult to sufficiently recover the oil-absorbing material of the first and second embodiments, and the use of the oil-absorbing material of the third embodiment is required. As the oil adsorbing material of the third embodiment, for example, there is Japanese Patent No. 2594507.

[0005]

However, the oil-absorbing material of the third form has excellent absorbency as compared with the first and second oil-absorbing materials, but it is still insufficient, and the price is generally high. is there. Therefore, there is a demand for an oil-absorbing material of the third embodiment that can absorb and hold oil more effectively and that can be produced at lower cost than before. The present invention satisfies such a demand.

[0006]

The present invention provides a starting material comprising a base material made of a polyolefin resin, a joining and lubricating material made of starch, and a functional material made of activated carbon. The starting materials are mixed in an extrudable state, and these materials are extruded into a predetermined shape to form an extruded body made of a steam foam, and thereafter, the extruded body is subjected to a heat treatment to thereby form an oil therein. The oil-absorbing material is manufactured by forming a water-repellent special three-dimensional structure for absorbing and retaining oil.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a flowchart showing a method for producing an oil-adsorbing material according to the present invention. The oil-adsorbing material according to the present invention, that is, the final target material, is manufactured by mixing the starting materials, extruding them, cutting them into predetermined dimensions or shapes as necessary, and subjecting them to heat treatment, for example, smoke treatment. Can be done.

[0008] The starting material is composed of a mixed material comprising a pellet-shaped base material, a joining and lubricating material, and a functional material. Here, the base material forms the base of the present oil-absorbing material, and is preferably made of a polyolefin resin, for example, polypropylene (PP), polybutadiene (PB), or a copolymer thereof. The joining and lubricating material functions as a solidifying or gluing agent for joining the base material and the functional material to each other and as a lubricant during extrusion work, and easily condenses when the starting material is heat-treated. It is composed of a material that disappears and is easily oriented when flowing, and specific examples thereof include starches, such as rice flour, vegetable protein gluten, bran, and rice bran. Further, the functional material is a main agent for absorbing oil and imparting water repellency, forming a gap structure in the base material and generating affinity for Van der Waals, and specifically, activated carbon, for example, pulverized coal or raw wood , A branch or the like, calcium carbonate or the like. Here, the pulverized coal constituting the functional material is obtained by putting charcoal into a pulverizer such as a crusher and pulverizing the pulverized coal to a size of about 2 to 100 microns. Similarly, raw wood, branches, or other wood materials (for example, charcoal) are processed into a very fine state by similar means, and are prepared in advance so that continuous extrusion can be easily performed.

The starting materials are mixed by a mixer known per se until the starting material components are homogeneously kneaded with one another.

The starting materials are then extruded by means of an extruder known per se into a continuous extruded body (rope-shaped) or a thin sheet extruded (mat, sheet) or other forms, depending on the application. Molded. It is preferable that the pushing operation is performed under a pressure at which the steam can be released, with the pressing force being reduced as much as possible with a pressure that prevents the return due to the back pressure of the steam.
By the extrusion operation under such conditions, the starting material is appropriately flow-oriented as it passes through the inside of the die of the extruder to provide a predetermined two-dimensional structure.

Then, when extruded from the die, steam for extrusion heating and generation of scattered blow form a steam foam to release steam entering the material.
Ensure the generation of through passages or bubble spaces. These voids secure a space where oil affinity (van der Waals force) can be used to a high degree.

Further, a thin skin by the base material is formed on the surface of the extruded product, and at the same time, a lateral swelling is generated, which gives cushioning as a mechanical strength. In this way, a material having a two-dimensional structure that provides the material with toughness during a tensile test can be formed.

Further, when the extruded product is separated from the die outlet of the extruder, the extruded product is released from the pressure in the die, so that the joining material generates a thermal change, and the starting material is an extruded foam having a three-dimensional structure. provide.

Next, the extruded product is cut or pulverized to a predetermined length as required. Needless to say, there is a case where a long rope state or a sheet state is wound up and a cutting step is not required.

Thereafter, the extruded foamed article is subjected to a heat treatment, preferably a smoke treatment, in a predetermined heating furnace or the like.
The purpose of this heat treatment is that the molded body just extruded from the die retains the material flow characteristics in the axial direction,
The tearing property in that direction remains strong, so that the tearing property is eliminated to give the extruded article a proper toughness, and the combustible material present in the starting material is heated and smoked. This is to form a stable special three-dimensional structure in the extruded product.

Here, the special three-dimensional structure refers to an infinite number of hollow portions which have hydrophobic or water repellent inside but can absorb and hold a large amount of oil by the affinity of Van der Waals. Is a structure in which gluten-like tissues are intertwined. The shapes of these special three-dimensional structures are clear from FIGS. Here, FIG. 2 is a cross-sectional photograph of the product of the present invention formed into, for example, a rope shape having a circular cross section, FIG. 3 is a cross-sectional photograph of the product of the present invention formed into a flat sheet shape, and FIG. FIG. 5 is an enlarged cross-sectional photograph showing a part of FIG. As shown in these cross-sectional photographs, the oil-adsorbing material product 10 of the present invention has a myriad of passages 14 having water permeability in the surface portion 12, having water repellency in the interior 16, and having the affinity of Van der Waals. It has a myriad of hollow portions 18 that absorb and retain a large amount of oil.

This special three-dimensional structure is characterized in that the functional material in the starting material is heated and reduced by a heat treatment such as a smoke treatment to form a cavity in that portion and, at the same time, a tar component generated at the time of the heating and reduction. Changes the OH contained in the resin of the base material to make the cavity hydrophobic, thereby providing an extremely important function as an oil-absorbing material capable of collecting oils dispersed in water. Is what you do.

Further, in this heat treatment, the base material in the starting material is melted, the external shape of the extruded product is maintained, and the cavity shape inside the molded product is stabilized.

By such a heat treatment, the material of the present invention can be freely bent and becomes a lightweight material which is extremely convenient to carry and handle. Further, as shown in FIGS. 2 to 4, the material of the present invention has an infinite number of hydrophobic hollow portions 18 formed therein, so that the weight ratio is 3 to 30.
It has been found to provide about twice as much oil absorption and oil retention.

It has been found that considerably different characteristics are imparted to the material depending on the processing temperature in the heat treatment step. That is, the heat treatment condition is 20
At a temperature of 0 to 350 ° C./5 to 60 minutes, the material is at a temperature at which fumigation and carbonization is performed. By removing water and heating the material, a light material in which a gluten-like tissue having a sufficient space inside is entangled can be obtained. provide. On the other hand, when the heat treatment conditions are 200 to 350 ° C./5 to 60 minutes, a texture structure that builds a three-dimensional space while leaving the structure at the time of molding is provided. In the heat treatment in this temperature range, It is possible to provide a material that can secure toughness such that the material is suitable for repeated use and that can withstand the strength of so-called heat compression. Therefore, the oil-absorbed material can be recovered by pressing, for example, by pressing or stepping on the foot, or by pressing, to separate the oil absorbed by the material from the material, and then repeatedly reusing the material for oil recovery. Can also be used. If heat treatment is performed at a higher temperature than this, the material will shrink and the molten resin will flow into the gaps in the special three-dimensional structure, reducing the gaps and reducing the toughness. However, when pressed, the material will break apart and collapse, making reuse difficult. In this case, it is incinerated after collection, and repeated use cannot be expected.

After the heat treatment, the material is finally taken out of the heating furnace.

In the case of using the oil adsorbing material according to the present invention, the material is arranged around the outside of the leaked oil as in the case of the oil fence, and the surrounding is gradually narrowed.
As a result, the oil instantly has the affinity and hydrophobicity of the material, and is thus adsorbed into the three-dimensional space of the material. Alternatively, the same adsorptive effect can be provided by dropping the material directly onto the leaked oil surface. The oil-adsorbed material can be collected at one place, separated into oils as described above, and then reused or incinerated together with the oil.

Examples of the starting material of the oil-absorbing material according to the present invention are shown by the raw material mixing ratio (Kg). However, the composition of the starting materials is not limited to this.

Table 1: Base material: PP 15.0 to 24.0 Bonding lubricant: Starch 22.5 to 36.0 Functional material: Calcium carbonate 1.0 to 16.0 Activated carbon, pulverized coal 20.0 to 50 0.0 The following Tables 2 to 7 show measured values relating to the amount of oil absorbed by the oil-absorbing material formed according to the present invention.

Table 2: The material sample of the present invention absorbs oils instantly. In the following, the oils were absorbed in the following oils for 5 minutes. Thereafter, the amount of absorbed oil was measured by the weight method every time. : Measure the weight immediately after lifting. : After leaving on Kimwipe for 5 minutes, the weight was measured. : Three Kimwipes were folded in two, pressed by hand and weighed. Salad oil ligroin trichloroethylene A heavy oil 14.68 9.22 16.23 11.03 12.41 8.18 14.05 9.88 4.04 1.91 3.15 2.37 /% residual 88.44 89.34 87.67 89.57 /% residual 27.47 22.22 19.64 21.49

Table 3: The weight loss (%) of the material sample after extrusion molding and after heat treatment was measured. Sample heating temperature residual rate Heating loss rate S 350 ° C 28.34 71.66 A 280 ° C 53.00 47.00 B 250 ° C 70.43 29.57 C 225 ° C 87.47 12.53 D 220 ° C 90.19 9.81

Table 4: The results obtained when each of the samples shown here were used as the A heavy oil-absorbing material were measured by the gravimetric method in the same manner as shown in Table 2 for the amount of absorbed oil. Sample A Sample B Sample C Sample D 11.03 13.00 12.01 10.35 9.88 11.10 10.64 9.35 2.37 2.41 1.90 1.96 / Residual% 89.57 85.38 88.59 90.34 /% residual 21.49 18.54 15.82 18.94

Table 5: The amount of each oil absorbed when the above heated sample S is used as an absorbing material is shown by weight ratio. Salad oil ligroin trichloroethylene A heavy oil 3.23 2.22 2.61 * 13.00 2.09 1.84 2.14 11.10 --- 2.41 where * is the test value for sample B.

Table 6: The results obtained by immersing the present material S in oils overnight (12 hours) are as follows. Salad oil ligroin trichloroethylene A heavy oil 4.13 2.69 3.77-3.19 2.38 3.25-

Table 7: Material near pure pulp at 350 ° C
The pulp heat-treated for 15 minutes was regarded as an oil-absorbing material with reference to the pulp, which was put into a wire mesh (made of copper), poured into a ligroin oil solution to absorb the ligroin, and the weight ratio was measured. The method is the same as shown in Table 2. From the above results, the following facts became clear. That is, as shown in Table 2, the material of the present invention has a small amount of separation due to oil dripping, has an extremely high oil retention property (keeps 88.4 to 89.6%), and has a high oil separation characteristic by pressurization (73). ~ 80
% Withdrawal). Therefore, as a material for collecting and utilizing oils, the material is suitable for pressure recovery. Further, from Table 3, it was found that as the heating temperature was increased, the raw material was changed in weight due to shrinkage and the volume was reduced, and the oil absorption was fluctuated. Tables 4 and 5 show these fluctuation situations. Therefore, from these facts, as the heat treatment temperature is lower, the oil retention is extremely high,
In addition, it was found that the oil releasing property by pressurization was rich. Further, from Table 6, the oil absorption amount of the oil-absorbing material according to the present invention is not directly proportional to the time during which the material is immersed in the oil solution, and almost reaches a peak state within about 10 seconds to 5 minutes. Thereafter, it was found that the amount of absorption gradually increased. Also, from Table 7, it is clear that the so-called sagging amount of the material close to pure pulp is larger than that of the product of the present invention, and even after squeezing, more than half remains in the material as the residual oil amount. Further, from the above results, the absorption weight ratio for Fuel Oil A was 10 to 10 for the treated materials of Samples A to D.
It shows a 13-fold absorption. As a result, 225 ° C. to 2
It has been found that the heat treatment at 50 ° C. has a good yield (utilization rate) which can be judged from the weight loss after extrusion of the raw material.

FIG. 6 shows the oil absorbing material according to the present invention.
A normal temperature sample (A), a heated sample (230 ° C.) (B),
Is shown by Fourier Transform Infrared Spectroscopy (FTIR) as usual, and the result (at Yamagata Prefectural Industrial Technology Center) is shown. From these results, the signal of the OH group and the CO group is less in the material of the present invention than in the heated product of the pulp according to the above patent, and the signal is not changed much. After the heat treatment, the infrared absorption band at 1720 nm is obtained. It is characterized by a state in which CO and carbonate (aliphatic), which are characterized by amplitude, are increasing. This means that the material is heated and smoked in the heating state of 220 ° C. or more, and it can be determined that formation of a special three-dimensional structure having acquired hydrophobicity is observed. Further, the transmittance is indicated by T%, and the wave number is 10%.
It should be noted that there are starches found near 00 Kaiser. That is, it is apparent from this that the essential elements for the formation of the three-dimensional structure in the present invention are included. Note that SCAN is 50 times.

The contents described so far relate to, for example, an example of an oil recovery material used for recovering oil in a state where oil diffuses and flows out onto the sea or the like and is still floating on the water surface. . However, the material of the present invention can be usefully used for recovery of oil submerged on the water bottom or the like by adjusting the specific gravity with, for example, calcium carbonate.

In order for the oil recovery material according to the present invention to function at the bottom of the water or the like, 1 to 16 kg that is effective against a chemical substance such as trichlorethylene in the starting materials shown in Table 1 in particular to increase the specific gravity due to sedimentation. About 10 to 16 kg of starch is added for resurfacing. Next, in the heat treatment step shown in FIG. 1, the heat treatment temperature is set low (about 200 to 300 ° C.) so that a part of the material exhibits hydrophilicity, or pulp or the like is added to the starting material. When about 3 by weight
Add extra water when heating ~ 15%, 10-60 minutes. When the raw material formed under such conditions is floated on the water surface in a mixed state or alone, the hydrophilic groups of the raw material call the surrounding water, and the raw material sinks against the buoyancy and reaches the water bottom. However, the special three-dimensional structure in the raw material can have both hydrophobic and lipophilic properties in many cases, and quickly absorbs oil deposited on the water bottom. After a while, the added calcium carbonate dissolves in the water and diffuses, and the specific gravity decreases. At this time, carbonic acid gas is generated by the decomposition of the hydrophilic portion such as glucose fermentation of the starch, and the material floats up to the water surface while absorbing the oil at the bottom of the water. If the surface is raised, the materials are collected and subjected to predetermined treatment such as incineration.

[0034]

The oil-absorbing material according to the present invention can absorb 10 to 20 times as much oil as before. If necessary, about 80% of the absorbed oil can be squeezed out and collected, so that the material can be reused and can be incinerated. Therefore, handling of this material is easy. In addition, oils having a specific gravity of 1.0 or more can be recovered, and can be used in various fields.

Further, the oil-absorbing material according to the present invention has a shape of an elongated rope, a sheet of a wide non-woven fabric, or the like so that it can respond promptly to a site where a disaster or the like occurs, or to its usage. It can be formed into a mat shape, a spherical shape that is easy to handle, or other shapes, and can be used easily and effectively in any state.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a method for molding an oil-absorbing material according to the present invention.

FIG. 2 is a cross-sectional photograph of an oil-absorbing material according to the present invention formed into a rope shape having a circular cross section.

FIG. 3 is a cross-sectional photograph of the oil absorbing material according to the present invention formed into a flat sheet shape.

FIG. 4 is an enlarged cross-sectional photograph of a part of FIG.

FIG. 5 is an enlarged sectional photograph in which a part of FIG. 4 is further enlarged.

FIG. 6 shows the oil absorbing material of the present invention at room temperature and at 230 ° C.
It is a figure which shows the result by FTIR at the time of heating to ° C.

[Explanation of symbols]

10: Oil adsorption material 12: Surface part 1
4: Passage 16: Inside 18: Cavity

Claims (6)

[Claims] 1. A substrate comprising a polyolefin resin,
Preparing a starting material composed of a joining and lubricating material made of starch, and a functional material made of activated carbon,
By mixing these starting materials into a state that can be extruded, extruding these materials into a predetermined shape, forming an extruded body made of a steam foam, and then subjecting the extruded body to a heat treatment A method for producing an oil-absorbing material, comprising forming a water-repellent special three-dimensional structure inside. 2. The method according to claim 1, wherein the starting material further comprises calcium carbonate. 3. The method for producing an oil-absorbing material according to claim 1, further comprising a step of cutting the molded body into a predetermined shape after forming the extruded molded body. 4. The method for producing an oil adsorbing material according to claim 1, wherein the heat treatment step is a smoke treatment. 5. A surface part having a myriad of water-permeable passages, a water-repellent interior, and a myriad of cavities that absorb and retain a large amount of oil due to the affinity of Van der Waals. Characterized by an oil-adsorbing material. 6. The oil-absorbing material according to claim 5, wherein the oil sinks from the water surface to the water bottom, absorbs oil deposited on the water bottom, and then floats to the water surface.