KR100405195B1 - Elastic graft polymer with network structure for oil absorption, and process for preparing them - Google Patents

Abstract

The present invention relates to an oil-absorbing elastic graft polymer having a network structure and a method for producing the same, more specifically, a content of unsaturated bonds (8% to 12%) is low, and light resistance (ΔE = 5 to 14) is low. It is prepared by crosslinking and reacting certain excellent rubbers with aliphatic or aromatic vinyl monomers having 3 to 18 carbon straight or branched chain substituents simultaneously with the addition of a crosslinking agent and an initiator, thereby providing excellent elasticity and selective adsorption and absorption of oil. The present invention relates to an absorbent elastic graft polymer having a greatly improved network structure and a method of manufacturing the same.

Description

Elastic graft polymer with network structure for oil absorption, and process for preparing them}

The present invention relates to an oil-absorbing elastic graft polymer having a network structure and a method for producing the same, more specifically, a content of unsaturated bonds (8% to 12%) is low, and light resistance (ΔE = 5 to 14) is low. It is prepared by crosslinking and reacting certain excellent rubbers with aliphatic or aromatic vinyl monomers having 3 to 18 carbon straight or branched chain substituents simultaneously with the addition of a crosslinking agent and an initiator, thereby providing excellent elasticity and selective adsorption and absorption of oil. The present invention relates to an elastic graft polymer for absorbing water having a greatly improved network structure.

In recent years, with the development of the industry, the amount of oil transportation and the number of transportations that are being transported to the land and the sea are rapidly increasing, and as the interest in the environment increases, the interest in the oil pollution on the land and the sea is also increasing. Although seawater may be contaminated by inflow of wastewater or waste, it is also seriously contaminated by a large amount of oil that flows out due to breakage of shipment during the transportation of crude oil. And on land, river water and soil are greatly polluted by oil spills. Therefore, there is an urgent need for a method for effectively removing oil spilled on land or at sea.

As a method for effectively removing oil spilled on the sea, a method of removing the oil using a low molecular emulsifier, a polymer excellent in adsorption and absorption to oil, or a foamed polymer in which these polymers are foamed is widely known. Currently absorbing polymers generally used are alkyl (meth) acrylates, alkylaryl (meth) acrylates, alkyl (meth) acrylamides, alkylaryl (meth) acrylamides, aliphatic vinyl esters, alkylstyrenes, and alpha as monomers. It is produced by polymerizing olefin, styrene and butadiene, polyurethane, and the like. However, it is pointed out that these conventional polymers have low oil absorption and are fragile and thus cannot be used directly in oil fence fabrication.

Therefore, there is an urgent need for the development of new materials for the production of oil-absorbing products having a slight elasticity and excellent absorption and absorption of oil.

The present invention has been made for many years to solve the problems of the low water-absorbent and elasticity of the conventional water-absorbing polymer at the same time easy to break, and as a result less unsaturated bond content (8% to 12%) than the conventional rubber monomer Select and use a specific rubber with excellent light resistance (△ E = 5-14) as a base, and polymerize it so that oil can be absorbed and adsorbed by crosslinking the vinyl monomer having a straight or branched chain with the graft polymerization. The present invention has been completed by obtaining an elastic graft polymer having an appropriate network structure.

Accordingly, an object of the present invention is to provide an elastic graft polymer having a network structure and a method for producing the same, which are useful for producing an oil-absorbent product such as an oil fence or an absorbent cloth.

1 is an electron scanning micrograph (× 1000) of each of an uncrosslinked polymer (a) prepared by the graft polymerization method and an elastic graft polymer (b) having a network structure of the present invention.

The present invention is aliphatic or aromatic having 10 to 50% by weight of rubber having a low content of unsaturated bonds (8% to 12%) and excellent light resistance (ΔE = 5 to 14) and a straight or branched chain substituent having 3 to 18 carbon atoms. It is characterized by an elastic graft polymer for absorption of water having a network structure prepared by graft crosslinking polymerization of 37 to 83% by weight of vinyl monomer, 2.5 to 20% by weight of crosslinking agent, and 1 to 10% by weight of initiator.

In the present invention, a crosslinking agent and an initiator are mixed with the above-described rubber and vinyl monomers, nitrogen or argon gas is added, and then the crosslinking reaction is carried out simultaneously with the graft polymerization at 50 to 120 ° C. for 6 to 120 hours to form a network structure. It is another feature of the method for producing an elastic graft polymer for absorption.

In another aspect, the present invention is characterized in that the absorbent elastic graft polymer having a network structure is dissolved in a solvent and coated with various nonwoven fabrics or sponges.

The present invention will be described in more detail as follows.

The absorbent elastic graft polymer having the network structure of the present invention has a low content of unsaturated bonds such as polybutadiene, poly (styrene-co-butadiene), poly (ethylene-co-propylene), and excellent rubber resistance and carbon number. An aliphatic or aromatic vinyl monomer having 3 to 18 straight or branched chain substituents is prepared by crosslinking at the same time as the graft polymerization under the addition of a crosslinking agent and an initiator.

The rubber used in the present invention has a low content of unsaturated bonds and excellent light resistance, and it provides the necessary flexibility in oil fence or adsorption cloth by imparting the property to form a film when it is included in a polymer having an oil absorption network structure. There is an advantage to grant. In other words, the conventional rubber has an unsaturated bond content of 30% or more, so that a polymer prepared by grafting a large amount of vinyl monomer onto a rubber having a high unsaturated bond content may have improved water absorption, but is poorly broken due to poor elasticity. Polymers prepared by grafting a small amount of vinyl monomers onto rubber having a high content of unsaturated bonds cannot be directly used for processing oil-absorbing products such as oil fences, but are elastic but have low oil-absorbing properties. Therefore, in the present invention, the content of unsaturated bonds is smaller than that of conventional rubber (8% to 12%), and also fade-o-meter (ATLAS, MINOLTA) or weather-o-meter (Weather) -O-meter: The rubber | dye which was excellent in light resistance was selected and used for the discoloration value ((E)) measured by ATLAS and CDMC-A) 5-14. The rubber used in the present invention is selected from polybutadiene, poly (styrene-co-butadiene) and poly (ethylene-co-propylene), and norborene for imparting a double bond to the poly (ethylene-co-propylene). It is also possible to use a rubber in the form of a diene monomer bonded, such as dicyclopentadiene, 1,4-hexadiene. The rubber described above is to be used in the range of 10 to 50% by weight with respect to the total elastic graft polymer, when the rubber is used in less than the amount used, there is a problem that the resulting polymer lacks flexibility and is fragile. Excessive use in excess of the absorbency is poor, due to the properties such as raw rubber, there is a problem in processing into an absorbent product such as oil fence.

In addition, aliphatic or aromatic vinyl monomers, which are characteristically used in the present invention, have a straight or branched chain substituent having 3 to 18 carbon atoms, and are grafted onto the rubber to impart properties such as thermoplastic polymers. This provides a slight elasticity that can be processed into oil-absorbing products such as oil fences, nonwoven fabrics, and sponges. The properties as a sorbent as described above are due to the affinity for the vinyl monomer to the oil. As the vinyl monomer used in the present invention, the aliphatic vinyl monomer is selected from acrylate and methacrylate derivatives, acrylamide and methacrylamide derivatives, and the like, and the aromatic vinyl monomer is selected from styrene and styrene derivatives. In particular, in the present invention, it is preferable to use a vinyl monomer having a straight or branched chain substituent having 3 to 18 carbon atoms in order to have good water absorption and a final elasticity of the graft polymer. The vinyl monomer described above should be used in the range of 37 to 83% by weight based on the total elastic graft polymer. If the amount of the vinyl monomer is less than the above range, it is the same as the unprocessed rubber property. There is a problem of falling, there is a problem in processing into an oil fence because it is fragile when used in excess of the above range.

The crosslinking agent that can be used for graft crosslinking polymerization of the rubber and vinyl monomers described above by the present invention is selected from divinylbenzene, tetraethylene glycol dimethacrylate, triethylene glycol dimethacrylate and ethylene glycol dimethacrylate. One or two or more. The crosslinking agent may be used in the range of 2.5 to 20% by weight based on the total elastic graft polymer. If the amount of the crosslinking agent is in excess of the above range, the crosslinking agent is easily broken and has low water absorption. There is a problem that can be dissolved in oil, oil absorption rate is reduced and processing is difficult.

The polymerization initiator to be used in the present invention is one selected from benzoyl peroxide, azobisisobutyronitrile, lauryl peroxide, acetyl peroxide, butyl peroxide, cumyl peroxide, butyl peracetate, butyl hydroperoxide The above is used in the range of 1 to 10% by weight based on the total elastic graft polymer.

In the present invention, the crosslinking agent and the initiator are mixed with the rubber and vinyl monomers described above, nitrogen or argon gas is added, and the crosslinking reaction is carried out simultaneously with the graft polymerization at 50 to 120 ° C. for 6 to 120 hours to form a network. It includes a method for producing an absorbent elastic graft polymer having a structure. In other words, the graft polymerization and the crosslinking reaction may be simultaneously performed under the above-described conditions by the production method according to the present invention to synthesize a network and elastic absorbent polymer having elasticity.

In the polymerization process according to the present invention, it is preferable to proceed in a nitrogen or argon gas atmosphere. The nitrogen or argon gas is continuously added to the polymerization tank during the polymerization process while controlling bubbles to be generated one drop per second. It is preferable that the polymerization to obtain the elastic graft polymer proceeds at 50 to 120 ° C. If the polymerization temperature is less than the above range, the yield of the grafted polymer is low. The problem arises. In addition, the polymerization is preferably carried out for 6 to 120 hours, if the polymerization time is less than the above range, the polymerization does not proceed completely, causing a problem that the yield of the coalescence of the present invention is reduced, if the above range Too much crosslinking results in polymers that are inelastic and brittle. After the completion of the polymerization reaction, the obtained polymer is precipitated in a non-solvent and then filtered and dried until it reaches a constant weight. In this case, one or two or more selected from methanol, ethanol and acetone may be used as the non-solvent.

1 is a non-crosslinked (no network structure) polymer (a) prepared by the above-described process and the absorbent elastic graft polymer (b) having the network structure of the present invention prepared by the above process (b) Electron scanning micrograph (x1000). According to Fig. 1, the oil-absorbing elastic graft polymer (b) having a network structure according to the present invention has fine pores of a suitable size, so that oil can enter therein and the surface of the pores is swelled by the oil. Since the absorbed oil does not come out, it can be usefully used as a material for manufacturing various absorbent products.

Accordingly, the present invention includes a water-absorbent product prepared by coating a non-woven fabric or sponge having a porous structure separately from the oil-absorbing sol-type elastomer obtained above. That is, the non-woven fabric or the sponge is coated on the water-absorbing sol-type elastomer obtained by the manufacturing method according to the present invention by dissolving in a solvent and spraying or depositing. In this case, one or two or more selected from ethyl acetate, toluene, dioxane, normal nucleic acid, and tetrahydrofuran are used as the solvent. The absorbent product manufactured in this way has a porous structure, thereby increasing the contact area between the oil and the sol-type elastomer for the absorbent, thereby helping to absorb and absorb the elastomer, as well as the nonwoven fabric or sponge. Since oil is also adsorbed and absorbed by itself, the absorbent product made is more effective in removing oil. In addition, a non-woven fabric or a sponge-based absorbent product coated with a sol-type elastomer exhibits a relatively high water absorption rate even when the content of the reticulum polymer is low, so that it is convenient to move or use in actual use. This can also be competitive in terms of low price.

The present invention will be described in more detail based on the following examples, but the present invention is not limited by the examples.

Examples 1-5

Poly (ethylene-co-propylene-co-5-methylene-2-norborene) (hereinafter abbreviated as "EPDM"), tertiary butylstyrene (hereinafter abbreviated as "tBS") and a crosslinking agent in a polymerization tank Vinylbenzene (hereinafter abbreviated as "DVB") was added and benzoyl peroxide (hereinafter abbreviated as "BPO") was added as an initiator. At this time, each content is shown in Table 1 below. Nitrogen gas was reacted in a polymerization tank equipped with an airtight device while controlling one bubble per second to emerge from the polymerization solution to obtain a tBS-g-EPDM-g-DVB (hereinafter, abbreviated as "PBED") elastomer.

The polymerized PBED elastomer was separated into a gel-PBED elastomer crosslinked during polymerization and a sol-PBED elastomer dissolved in a solvent during the extraction process after polymerization. The cross-linked gel-PBED elastomer was prepared as an absorbent elastomer by being precipitated in non-solvent methanol, followed by filtration and drying until a constant weight. The sol-PBED elastomer which can be dissolved in a solvent extracted with toluene or THF is crosslinked again by UV light, thereby preparing an absorbent elastomer. In addition, the sol-PBED elastomer was dissolved in toluene or THF solvent and coated on a nonwoven fabric (Kolon, P512-RB-115) by spraying or dipping to prepare a sol-PBED coated nonwoven fabric.

Examples 6-9

First, 2-hydroxyethylmethylacrylate, cinnamoyl chloride, and triethylamine are mixed and refluxed, filtered, and distilled at 0 ° C. for 4 hours. Cinnamoyloxymethyl methacrylate (hereinafter, “CEMA "Abbreviated").

EPDM and tBS, CEMA prepared above was added to the polymerization tank, and BPO was added as an initiator. At this time, each content is shown in Table 2 below. Then, nitrogen gas was reacted in the airtight polymerization tank for 1 hour at 70 DEG C while controlling one bubble out of the polymerization solution for twenty-eight hours to obtain tBS-g-EPDM-g-CEMA (hereinafter referred to as "PBEC"). Abbreviated D) to prepare an elastomer.

The PBEC elastomer obtained as described above was precipitated in methanol as a non-solvent, and then filtered. Then, PBEC elastomer for water absorbent was prepared by extracting with toluene or THF solvent and drying until it became a constant amount.

The PBEC elastomer was coated on the nonwoven fabric using the same method as Examples 1 to 5 to obtain a nonwoven fabric or sponge coated with PBEC.

Experimental Example 1

The water absorption rate of the absorbent elastomers obtained in Examples 1 to 9 and the nonwoven fabric coated with these elastomers was measured according to the ASTM F726-81 method.

Toluene was added to the crude oil to dilute the crude oil to 10% by weight to make diluted crude oil. The diluted crude oil was weighed with the absorbent elastomer of Examples 1 to 9 or the nonwoven fabric coated with these elastomers to absorb the diluted crude oil, and then the swelled elastomer or the nonwoven fabric coated with the elastomer. The weight was measured. The oil absorption rate was calculated by Equation 1 below, and the oil absorption results of the crude oils of Examples 1 to 5 (PBED) and Examples 6 to 9 (PBEC) were shown in Tables 1 and 2, respectively. The maximum oil absorption time is the time required for the maximum oil absorption rate.

division Example One 2 3 4 5 Composition (% by weight) Rubber EPDM 10 20 30 40 50 Vinyl monomer tBS 82.5 72.5 62.5 47.5 42.5 Crosslinking agent DVB 5 5 5 5 5 Initiator BPO 2.5 2.5 2.5 2.5 2.5 Absorption Rate (%) Gel-PBED 8400 5100 3200 1500 1100 Sol-PBED 3300 2800 1200 2100 2600 PBED Coated Nonwovens 800 800 800 900 700 Non-woven 300 300 300 300 300 Oil absorption time (hr) Gel-PBED 96 960 96 72 72 Sol-PBED 12 24 12 24 24 Sol-PBED Coated Nonwoven Fabric 2 24 24 2 One Non-woven 5 5 5 5 5

division Example 6 7 8 9 Composition (% by weight) Rubber EPDM 10 20 30 40 Vinyl monomer tBS 67.5 52.5 47.5 37.5 Crosslinking agent CEMA 20 20 20 20 Initiator BPO 2.5 2.5 2.5 2.5 Absorption Rate (%) Gel-PBEC 1900 1250 1200 900 Sol-PBEC 1500 1100 900 800 PBEC Coated Nonwovens 1100 850 800 750 Non-woven 300 300 300 300 Oil absorption time (hr) Gel-PBEC 2 10 10 One Sol-PBEC 6 12 6 8 Sol-PBEC Coated Nonwoven Fabric 8 6 10 2 Non-woven 5 5 5 5

According to the results of Tables 1 to 2, the rubber having a low content of unsaturated bonds (8% to 12%) and excellent light resistance (ΔE = 5 to 14) according to the present invention, and a straight or branched chain having 3 to 18 carbon atoms The elastic graft polymers of Examples 1 to 9 prepared using aliphatic or aromatic vinyl monomers having substituents were excellent in absorbency and had properties that were not broken even when coated on a nonwoven fabric.

The following Table 3 shows the water absorption of α-Gel products (Japan α company, styrene-butadiene-styrene block copolymer) that are commercially available as a polymer for absorption. . (However, detailed comparison could not be made because the characteristics and physical properties were not disclosed.)

division Commercial product α-Gel-1000 α-Gel-1650 Absorption Rate (%) Amount of toluene (unit%) until it is absorbed and solidified in 10 minutes 400-667 The amount of crude oil (unit%) until it is absorbed and solidified in 10 minutes 400-667

According to the results of Table 3, in the ability to absorb the diluted crude oil, the PBED or PBEC elastomers of the present invention exhibited much better maximum oil absorption than conventional styrene-butadiene-styrene adsorbents that are widely used for conventional oil absorption. have. Moreover, the oil absorption of the nonwoven fabric coated with these polymers also shows much better results than the nonwoven fabric itself.

In order to absorb and remove a large amount of oil spilled on the ground or the ocean, it is more competitive to absorb and remove a large amount of oil using a small amount of absorbent. It is characterized by very excellent.

Experimental Example 2

The structures of the water-absorbing elastomer polymerized in Examples 1 to 5 and 6 to 9 were confirmed using a Fourier transform infrared spectrometer (FT-IR, Perkin, Perkin-Elmer 1330 model name).

tBS-g-EPDM-g-DVB (PBED) Elastomer:

IR (KBr) υ _MAX : 3010, 2900, 1465, 1380, 900 to 790 cm ^-1

tBS-g-EPDM-g-CEMA (PBEC) elastomer:

IR (KBr) υ _MAX : 3010, 2900, 1730, 1620, 1465, 1380, 900 to 790 cm ^-1

As described above, the oil-absorbing elastic graft polymer having a network structure prepared according to the present invention has a high oil adsorption and a water absorption rate higher than that of the conventional oil-absorbing polymer, and is very useful. Absorption product using was effective in improving the absorption rate compared to the nonwoven fabric itself.

Claims (9)

In the water-absorbing elastic graft polymer prepared by graft polymerization of a rubber polymer and a vinyl monomer, Aliphatic or aromatic vinyl monomers having 10 to 50% by weight of rubber having a low content of unsaturated bonds (8% to 12%) and excellent light resistance (ΔE = 5 to 14) and a straight or branched chain substituent having 3 to 18 carbon atoms. To 83% by weight and 2.5 to 20% by weight of the crosslinking agent are crosslinked and polymerized at the same time as the graft polymerization, and the oil absorption rate (%) calculated by Equation 1 is 800 to 8400. Elastic graft polymer for absorption. [Equation 1] The elastic graft polymer for absorption of water according to claim 1, wherein the rubber is at least one selected from polybutadiene, poly (styrene-co-butadiene), and poly (ethylene-co-propylene). . According to claim 2, wherein the poly (ethylene-co-propylene) is absorbent elastic having a network structure, characterized in that the diene monomer selected from norborene, dicyclopentadiene and 1,4-hexadiene is combined. Graft polymer. According to claim 1, wherein the vinyl monomer is one or more selected from acrylate derivatives, methacrylate derivatives, acrylamide derivatives, methacrylamide derivatives, styrene and styrene derivatives having a straight or branched chain substituent of 1 to 18 carbon atoms An absorbent elastic graft polymer having a network structure. The elastic graft polymer for water absorption according to claim 1, wherein the crosslinking agent is at least one selected from divinylbenzene derivatives and dimethylacrylate derivatives including tetraethylene glycol dimethylacrylate. The method of claim 1, wherein the initiator is selected from benzoyl peroxide, azobisisobutyronitrile, lauryl peroxide, acetyl peroxide, butyl peroxide, cumyl peroxide, butyl peracetate, butyl hydroperoxide Absorbent elastic graft polymer having a network structure, characterized in that the above. delete A water-absorbent product, characterized in that the water-absorbent elastomer having a network structure of claim 1 is dissolved in a solvent and coated on a nonwoven fabric or a sponge. The absorbent article as set forth in claim 8, wherein the solvent is at least one selected from ethyl acetate, toluene, dioxane, normal nucleic acid, and tetrahydrofuran.