JPS608033B2 - Spilled oil adsorbent and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spilled oil adsorbent using natural vegetable fibers and a method for producing the same, and more specifically, it has excellent oil absorption performance,
This invention relates to a spilled oil adsorbent containing kapok fiber (hereinafter abbreviated as oil adsorbent) that maintains its original shape and floats stably for a long period of time when placed on the sea, and a method for producing the same.

Recently, accidents in which oil spills onto the water surface of the sea or rivers from oil tankers, oil terminals, oil refineries, and other oil storage areas have been occurring frequently, and the scale of these spills has become larger, causing widespread contamination. be.

Oil adsorbents are used to collect spilled oil on the water surface during these accidents, but most of the conventional oil adsorbents are made of synthetic resins such as polypropylene and polyurethane foam. Incineration after collection is extremely difficult. These synthetic resin adsorbents melt when incinerated and emit high heat when burned, so it is necessary to use a special incinerator. Therefore, there are many inconveniences, such as the need for long transportation as the waste must be incinerated at the site after being collected. Furthermore, among polypropylenes, the most commonly used attack type polystyrene and polystyrene are easily soluble in oil, and therefore swell and disintegrate after absorbing oil, resulting in a large amount of unrecovered waste, which has a negative impact on marine resources. From these points, natural oil adsorbents made from pulp, cotton, etc. have been proposed, and some of them are commercially available.

Natural product-based oil adsorbents have the advantage of being easy to incinerate and have little risk of secondary pollution, but they generally have poor water repellency, tend to sink easily in water, and are expensive. There is a drawback. The present invention overcomes the shortcomings inherent in conventional oil adsorbents, and provides an oil adsorbent based on natural fibers that has excellent oil absorption and water resistance, as well as good incineration properties, and a method for producing the same. The purpose is to

That is, the oil adsorbent of the present invention is composed of kapok fiber and 5 to 100 parts by weight of fibrous polyethylene or isotactic polypropylene per 100 parts by weight of the kapok fiber, and the kapok fiber is composed of the fibrous polyethylene or isotactic polypropylene. It is characterized by being glued and fixed with solid polypropylene.

Further, the method for producing the oil adsorbent of the present invention includes kapok fiber 10
and 5 to 10 parts by weight of fibrous polyethylene or isotactic polypropylene.
The method is characterized in that the kapok fibers are bonded and fixed via the fibrous polyethylene or isotactic polypropylene by heating at 0 to 250 degrees Celsius.

Hereinafter, the oil adsorbent of the present invention and its manufacturing method will be specifically explained.

First, kapok fiber, which is the main material of the oil adsorbent of the present invention, is obtained from kapok seeds.

Kapok is a type of tree in the Panya family that grows in tropical and subtropical regions, and is now mainly produced in Southeast Asia, mainly in Indonesia.

The seeds are oval shaped with 12 skins in the major axis and 5 skins in the minor axis, but these have short hairs, and the kapok fibers that are collected from these hairs are 15 to 3 hairs in length. Kapok fiber has poor spinning properties, so it is used as stuffing for futons, pillows, cushions, etc., and as raw material for lifesaving equipment. However, the present inventors have noticed that this kapok fiber is extremely lipophilic, and have investigated its application as an oil adsorbent.

The characteristics of Kapok fiber as an oil adsorbent are that it contains cutin (wax) and is hydrophobic, so unlike other natural fiber adsorbents, it does not require water repellent treatment and has a high density of approximately 0. .03, which is extremely small and has a structure with many voids.

When an adsorbent is placed on the sea surface, oil is absorbed and retained in the voids, so it can be said that kapoku fibers with low density have suitable properties as an oil adsorbent. Currently, oil adsorbents that are certified as legal equipment in Japan must pass the standards stipulated in Article 33-2 of the Enforcement Regulations of the Marine Pollution Prevention Act.

This standard stipulates oil absorption, water absorption, original shape retention, storage, retrieval, incineration, etc. Oil adsorbents that pass these regulations have certain limits in their form, and usually the size of one sheet of adsorbent is around 50 x 50 skin, the thickness is 5 to 1 inch, and the weight after oil adsorption is 1 to 3 kg. It is desirable that Therefore, as a practical oil adsorbent, it is necessary to form it into a thick flat plate. However, kapok fiber has the disadvantage that it is difficult to process, so it cannot be processed into the shape of an oil adsorbent. In other words, since kapok fiber is a short fiber, has a small fiber diameter, and is lightweight, it cannot be flattened by needling etc. due to scattering of the fibers and insufficient intertwining of the fibers during processing. It is extremely difficult to process, and even if it is processed, the efficiency of commercialization is extremely low, and there are many problems such as the inability to produce products with a thickness of 5 ribs or more. Therefore, kapok fiber can of course be used as an oil adsorbent.
Even in normal applications, it is not used by molding or twilling, but is used in its original form. However, by employing the present invention, these drawbacks of kapok fiber can be overcome and kapok fiber can be formed into a mat or flat plate without impairing its properties as an oil adsorbent.

That is, short fibers are mixed into the kapok fiber mass, and these fibers are intertwined with the kapok fibers to prevent the scattering of the kapok fibers and are preformed into a certain shape.Then, this preform is compressed. A thick nonwoven fabric can be obtained from the kapok fibers by heat-treating and fixing the kapok fibers to each other via the mixed short fibers. As the fibers used for the above purpose, linear polymers made of any heat-melting synthetic polymer can be used, but preferably fibers made of hydrocarbon polymers, especially polyethylene, polypropylene, and polystyrene. selected from fibers.

Among these, polypropylene and polyethylene are particularly preferred, as they can also be used as adhesives for bonding and fixing kapok fibers to each other, and can be formed into sheets of fixed dimensions by heat treatment without the use of separate adhesives. It is possible to do so. Isotactic polypropylene (hereinafter abbreviated as polypropylene) is used as the polypropylene because of its solubility in oil.

However, isotactic polypropylene has a slightly high melting point of about 160-170°C, so from the economic standpoint of heat treatment, fibrous polyethylene with a low melting temperature (melting point of about 120-140°C) is the best. A preferred material. The shape of these heat-meltable synthetic polymer fibers is usually
The fiber length is 3 to 8 willows and the diameter is 100 to 200 fibers, and can generally be produced by a wet method.

After preparing the above-mentioned kapok fibers and fibrous polyethylene or polypropylene, the kapok fibers are opened using a dehairing machine, and 5 to 100 parts by weight of a fibrous hot-melt synthetic polymer is added to the kapok fibers per 10 parts by weight of the kapok fibers. More preferably, 20 to 4 parts by weight are mixed to obtain a fleece-like material in which both fibers are uniformly mixed.

Next, the fleece-like material is set to the required thickness as an adsorbent and heat-treated.

The heat treatment temperature is determined based on the melting point of the fibrous heat-melting synthetic polymer used. That is, the fibrous hot-melt synthetic polymer melted by this heat treatment adheres to the kapok fibers at the point of contact with the kapok fibers, thereby preventing the kapok fibers from falling apart. Usually, the heat treatment temperature is in the range of 130 to 250 degrees centigrade, and the heat treatment time is 7 to 30 minutes. Heating temperature is 1300
If it is less than 0, welding will be insufficient, and if it exceeds 250 oo, the fibrous polyethylene or polypropylene will easily decompose, which is not preferable. Furthermore, if the heat treatment time is less than 7 minutes, welding will be insufficient, and if it exceeds 30 minutes, a tendency for thermal decomposition will appear. After heat treatment, the adsorbent of the present invention can be obtained by cutting it into an appropriate size or winding it up as it is.

The obtained oil adsorbent usually has a high density of 0.03 to 0.08, although it varies depending on the amount of fibrous polyethylene or polypropylene mixed and the degree of compression of the fleece material. In addition, if an adsorbent with particularly high oil absorption performance and high strength is required, natural fiber fabrics such as gold cloth or hessian cloth, or synthetic fiber networks such as polyethylene, polypropylene, nylon, or acrylic may be used as the adsorbent. The strength can be strengthened by attaching it continuously to both sides.

However, in this case, unlike conventional natural fiber-based adsorbents, there is no need for any process such as inserting the adsorbent into a net, and a practical oil adsorbent can be obtained. This point is one of the major features of the present invention. According to the oil adsorbent of the present invention,
Since the kapok fibers are bonded and fixed by the fibrous polyethylene or polypropylene, the kapok fibers are prevented from falling apart, providing excellent dimensional stability and maintaining sufficient strength.

In addition, by using fibrous polyethylene or polypropylene in combination with kapok fiber, it is possible to form sufficient voids between the kapok fibers, and oil enters into these voids, which improves the water repellency of fibrous polyethylene or polypropylene. In addition to oil absorption, kapok fiber can fully exhibit its inherent water repellency, particularly excellent lipophilicity.

Furthermore, in the present invention, 5 to 100 parts by weight of polyethylene or polypropylene fibers are used per 10 parts by weight of kapok fibers, so in terms of incineration, for example, by appropriately selecting the amount of polyethylene or polypropylene, the mixed amount can be adjusted. Up to 5% by weight, the incineration treatment after oil adsorption can be carried out almost in the same way as in the case of kapok fiber alone.

Moreover, it has been confirmed that no toxic gases such as chlorine or hydrogen cyanide are generated during incineration. As a result, the oil adsorbent of the present invention has the following characteristics: (1) oil absorption, (2) water absorption, (3) combustibility, and It passed all of the breakage test, oil resistance test, weight test, sedimentation test, and strength test. Furthermore, the oil adsorbent of the present invention can be manufactured easily and inexpensively by a simple operation of mixing kapok fibers with polyethylene or polypropylene fibers and heating the mixture to bond the kapok fibers. Next, a specific manufacturing method and the characteristics of the adsorbent obtained by the method will be described in detail using Examples.

The test method used in the following Examples to evaluate the oil adsorbent of the present invention based on the Enforcement Regulations of the Marine Pollution Prevention Act is as follows.

{i1 Oil absorption 10×10 skins, thickness 0.7 arc test piece at 20°C - 1°C
The test specimen was floated on the surface of B heavy oil and allowed to stand still for 5 minutes, and then left for 5 minutes on a mesh-like wire mesh with a diameter of 1 sail on the sieve mesh length of 17. Measure the weight.

Calculate the oil absorption per weight of the test piece and per volume of the test piece.

Oil absorption amount of 6 kg or more per test piece per night and 0.3 # per block
The above is a pass.

[Note] Two oil absorbent test pieces with a water absorption capacity of 10 skin x 10 cm and a thickness of 0.7 skin.
Float on the diving surface at 0°C ± 1°C and stand still for 5 minutes.

Next, the weight of the oil adsorbent was measured after leaving it for 5 minutes on a wire mesh similar to that used in [A' above.

Measure the amount of water absorbed per test piece and per volume.

Water absorption amount of oil adsorbent per night is 1.5 ta or less and 0 per night
．． A score of 1 ta or less is considered a pass.

Flammability While melting, polyethylene and polypropylene fall in the form of water droplets while igniting, and burn without spreading.
And if it can be incinerated in a normal incinerator, it passes the test.

In addition, in the combustion test according to the Marine Pollution Prevention Act, the criterion is the amount of HCN generated by combustion.

However, in the oil adsorbent of the present invention, as mentioned above, HC
Since it was confirmed that no N was generated, the unique test method described above was adopted only for this combustibility.

Normally, with oil adsorbents made only of polyethylene or polypropylene fibers, the polypropylene melted during combustion ignites and falls in the form of water droplets, causing the flame to spread. Also, polyethylene and polypropylene require a special combustion furnace because they have a high calorie content when burned. 0 Oil resistance 5 x 5 skin, 0.7 x 0.7 x oil adsorbent test piece with A heavy oil 1
Pour into a reagent bottle containing a mixture of 80% oil and 120% gasoline and leave for 7 hours.

If a non-oil resistant binder is used in the oil adsorbent, the test piece will have loose fibers, shrink, or swell.

If there is no such phenomenon, the test is passed. Weight test 10 skins x 10 skins, 20 oil absorbent test pieces with a thickness of 0.7 arc
q○ Soil Immerse in heavy oil B at 1°C for 5 minutes, leave on a wire mesh for 5 minutes, and then measure the weight of the test piece.

From this measured value, the total weight of the oil adsorbent product that has adsorbed oil is calculated.

If the total amount of troops is 0.5k9 or more and less than 3k9, the test is passed.

For example, if the weight of one oil absorbent product is 100 mm, the test piece (
If the oil absorption amount per unit weight of 10cm x 10cm (thickness 0.7 arc) is 15 ta', the weight of the oil absorbent product after oil absorption is 15 ta' x 100 (oil absorption amount) 1100 ta. (Weight of the product itself) = 1.6k9, and passed.

H Damage test 5cm x 5 skin, 0.7cm thick oil absorbent test pieces were placed in a reagent bottle (JIS350) containing 300' of fresh water.
Capacity 1 by 3 (in a wide-mouth stoppered bottle), 120 per minute
Horizontal vibration is given for 2 hours in a reciprocating manner with an amplitude of 4 degrees.

If there is no damage such as fragmentation of the test piece, separation into multiple pieces, lump-like shape, or large amount of material remaining after the test piece is lifted, the test is passed. River Sedimentation test 5 skin x 5 cm, 0.7 skin thick oil adsorbent test piece was placed in fresh water 3
Place it in a reagent bottle marked 00' and apply horizontal vibrations at 12 main vibrations and 4 amplitudes per minute for 2 unique intervals.

The test passes if part of the test piece is above the water surface. Strength test A willow hook with a diameter of 8 is hung at a position of 10 points from one end of the oil adsorbent, and a load of 2.5 times the weight measured in the weight test is applied to one point in the vertical direction.

If the oil adsorbent does not break after 3 minutes, the test is passed.

Example 1 First, the kapok fibers were uniformly unraveled using a dehairing machine.

Next, fibrous polyethylene (product name Zerapack E400)
(manufactured by Mitsui Zerapack ■, melting point: approximately 130°C) was uniformly woven using a dehairing machine to obtain fibers with a fiber length of approximately 5 to 8 strands and a length of approximately 100 to 200 〆.

This fibrous polyethylene is added to the woven kapok fibers in an amount of 5 to 100 parts per 100 parts by weight of dry kapok fibers.
The amounts added were varied within the range of parts by weight, and the mixture was uniformly mixed in a mixer to obtain a mixing line.

Next, this mixed wire was supplied to a streamliner via a hopper to produce a fleece. The thickness of the fleece was about 100 mm, and the thickness of the fleece increased as the amount of fibrous polyethylene used increased. Furthermore, the mixing ratio of kapok fiber and fibrous polyethylene was determined taking into account the desired high density of the oil adsorbent.

Generally, as the amount of kapok fiber mixed increases, the high density of the oil adsorbent decreases, ranging from 0.03 to 0.08. Next, the obtained fleece is laminated, compressed to a thickness of about 50 to 200 mm depending on the shape of the desired oil adsorbent, and heated to 180 mm in a heat curing oven to form a fibrous polyester. Kapok fiber is bonded by hot melting of
It was fixed.

After the heat treatment, it was cut or wound into a roll to obtain an oil adsorbent.

Regarding the obtained oil adsorbent, the oil adsorbent of the present invention was cut to prepare a test piece according to the test method based on the Marine Pollution Prevention Act Enforcement Regulations mentioned above, and the test piece was subjected to a test.

The properties and test results of the oil adsorbent are shown in Table 1 below.

As is clear from Table 1, the oil adsorbent of the present invention passed all test items.

Table 1 Example 2 Two parts of a fiber mass mat prepared by mixing 10 parts by weight of kapok fiber with 15 parts by weight of polyethylene fiber in the same manner as in Example 1 was prepared.
An oil absorption test, a water absorption test, a weight test, a breakage test, a sedimentation test, and a strength test were conducted on the test piece having a bulk density of 0.033 obtained by heating and cutting at 0.000°C.

As a result, the oil absorption amount is 6 ta or more for oil adsorbent 1 and 0.8 ta or more per 1 flow, and the water absorption amount is 1.5 ta or less for oil adsorbent 1 and 0 ta for 1 flow. It was less than .1 ta and passed in all cases. In the weight test, one test piece of 10 skins x 10 cm and 0.7 cm thick was used to measure the weight after oil absorption. Note that the marine pollution prevention law mentioned above stipulates a test piece of 10 skins x 10 skins and a thickness of 0.7 skins, and the size of one sheet of the oil-absorbing material of the present invention is 50 skins x 5 skins.
Since it is 0 skin and 0.7 cm thick, I measured the weight by 23 tones to make it meet the standard. As a result, the weight of one test piece was 2.12k9 and the other was 1.85k9, and both passed the test. In the breakage test, none of the defects mentioned above were found; in the dissolution test, there was no phenomenon of the kapok fibers falling apart or shrinkage or swelling of the test piece; and in the sedimentation test, the test piece remained above the water surface from beginning to end; , was judged to have passed. In addition, in the strength test, 2% of the weight of the adsorbent after oil absorption measured in the weight test. Needle sound, that is, one adsorbent has 2
．． 12k9 x 2.5 = 5.3k9, 1 for other adsorbents.
A load of 85kg x 2U5 = 4.7k9 was applied, but the test was passed for 3 minutes without any breakage.

Example 3 An oil adsorbent was manufactured using the same machine as in Example 1 using kapok fiber and the same fibrous polyethylene or powdered polyethylene as in Example 1, and a strength test was conducted as described in Example 2. Ta.

Three oil adsorbent samples were prepared for each sample. Second result
Shown in the table. Table 2 However, the sample composition is as follows.

Sample No. 1 Weight% of fibrous polyethylene 1
Kapok fiber 90 bulk density
0.035 Sample No. 2 Powdered polyethylene 1% by weight
Kapok fiber 90〃high density
0.035 As is clear from Table 2, when powdered polyethylene is used, the strength decreases and an oil adsorbent that passes the provisions of the Marine Pollution Prevention Act cannot be obtained.

This is because powdered polyethylene is difficult to mix uniformly with kapok fiber unlike fibrous polyethylene. Reference Example Table 3 below shows the difference in oil adsorption capacity between the kapok fiber used in the present invention and conventionally used cotton fibers and crude linter fibers.

The properties of each test piece used here are as follows.

Kapok fiber: Kapok fiber alone has a bulk density of 0.
．． The shape was adjusted to 057 and housed in a bag-like net.

Approximately 50 x 50 skins, thickness approximately 0.7 skins. Crude linter fiber:
A cloth with a high density of 0.09, approximately 50 skins x 50 skins, and a thickness of approximately 0.7 skins was formed from 150 grains of coarse linter fiber. Taimaku Senso: Line fiber 150mm, bulk density 0.09, approximately 50c x 5
A towel-like cloth with 0 arc and a thickness of about 0.7 arc was formed.

The test method followed the test method based on the Marine Pollution Prevention Act.

As is clear from the above results in Table 3, in the case of twill fibers and coarse linter fibers, the amount of oil absorption is significantly lower than that of kapok fibers, and on the other hand, it is clear that the amount of water absorption is extremely large.

Example 4 5 to 1 part by weight of isotactic polypropylene fiber was added to 10 parts by weight of kapok fiber in the same manner as in Example 1.
Oil adsorbents were produced by varying the amount added within a range of 0 parts by weight.

In addition, as isotactic polypropylene fiber,
Product name: P-37, made of Mitsubishi rayon column, melting point of approximately 17 is 0
was used.

A test piece was prepared from the obtained oil adsorbent and subjected to the test in the same manner as in Examples 1 and 2.

The test results are shown in Table 4 below.

As is clear from Table 4, all test items were passed even when isotactic polypropylene was used.

Table 4

Claims (1)

[Scope of Claims] 1 Consisting of Kapok fibers and 5 to 100 parts by weight of fibrous polyethylene or isotactic polypropylene per 100 parts by weight of the Kapok fibers, wherein the Kapok fibers are composed of the fibrous polyethylene or isotactic polypropylene. A spilled oil adsorbent characterized by being bonded and fixed with polypropylene. 2. Mix 100 parts by weight of Kapok fiber and 5 to 100 parts by weight of fibrous polyethylene or isotactic polypropylene, and heat this to 130 to 250°C to convert the Kapok fiber into the fibrous polyethylene or isotactic polypropylene. A method for producing a spilled oil adsorbent, characterized by adhering and fixing the spilled oil adsorbent.