United States Patent (19) (11 3,892,688 Motani et al. (45) July 1, 1975 54) N-THOCARBAMOYL 3,196,107 7/1965 Tomic................................... 20/38 POLYALKYLENEPOLYAMINE GROUP 3,473,921 10/1969 Schmuckler.......................... 75/18 CONTAINING HEAVY METAL ADSORBNG 3,687,908 8/972 Pickleshimer...................... 260/79.5 RESINS OTHER PUBLICATIONS I75 Inventors: Kensuke Motani; Akihiko Nakahara; Nobuyuki Kuramoto, all Campbell et al., J. Polym. Sci. 62, 379-86(1962). of Tokuyama, Japan 73) Assignee: Tokuyama Soda Kabushiki Kaisha, Primary Examiner-Melvin Goldstein Japan Attorney, Agent, or Firm-Sherman & Shalloway (22) Fied: May 30, 1974 21 Appl. No.: 474,723 57) ABSTRACT Related U.S. Application Data (62) Division of Ser. No. 339,382, March 7, 1973, Pat. A heavy metal adsorbing resin of which the main poly No. 3,847,841. mer chain consists of an aliphatic hydrocarbon skele ton and which contains at least one functional group (30) Foreign Application Priority Data selected from amino, polyalkylene polyamino, hy drazido, thioureido, thiosemicarbazido, isothi Mar. 11, 1972 Japan................................ 47-24424 ocyanato, thiobiuret, N-thioaminobiuret, and Mar, l 1, 1972 Japan. ... 47-24.425 N-thiocarbamoyl-polyalkylene amino groups. Heavy Mar. 1, 1972 Japan. ... 47-24426 metals can be removed from a solution containing Mar. 1, 1972 Japan................................ 47-24427 them by contacting the solution with the above heavy metal adsorbing resin. The resin has a markedly high 52 U.S. Cl......... 260/2.2 R; 210/24; 260/79.5 NV; rate of adsorbing the heavy metals, and can be easily 423122; 423/24; 423/49; 423154; 423187; regenerated with a mineral acid or sodium sulfide. The 423/100 suitable time of regenerating or replacing the resin can 51 Int. Cl. C08f 27/02; C08f 27/04 be detected by its color change upon adsorption of the 58) Field of Search.................. 260/2.2 R, 79.5 NV heavy metals. 56 References Cited UNITED STATES PATENTS 2,890, 180 6/1959 Cerny et al.......................... 260/2. 2 Claims, No Drawings 3,892,688 2 N-THIOCARBAMOYL adsorbing ability decreases with the passage of the time POLYALKYLENEPOLYAMINE GROUP of contact with heavy metal containing solutions, re CONTAINING HEAVY METAL ADSORBING sulting in a gradual increase in the concentrations of RESINS the heavy metals remaining in the solutions after 5 contact. This is a division of application Ser. No. 339,382, Since the resin of this invention exhibits a clear dis filed Mar. 7, 1973, now U.S. Pat. No. 3,847,841. coloration upon adsorption of heavy metals, it serves to This invention relates to a resin having the property determine whether the adsorbing ability of the resin has of adsorbing heavy metals. More specifically, it relates reached saturation. Therefore, one can easily see when to a heavy metal adsorbing resin of which the main 10 the resin of this invention should be regenerated or re chain consists of an aliphatic hydrocarbon skeleton and placed, and this adds to the commercial advantage of which contains at least one functional group selected the resin in accordance with the present invention. The from the group consisting of amino, polyalkylene poly resin of this invention can also be used as an expedient amino, hydrazido, thioureido, thiosemicarbazido, iso for detecting the presence of heavy metals in waste wa thiocyanato, thiobiuret, N-thioaminobiruet and N-thi 15 ter. The heavy metal adsorbing resin also lends itself to ocarbamoylpolyalkylene amino groups. easy handling because of its superior mechanical Methods have previously been known to remove strength, and is scarcely broken during its regeneration heavy metals such as mercury from a solution contain or scarcely lost during its production by granulation. ing them by causing an anion exchange resin to adsorb This if, of course, economically advantageous. them. However, these methods are commercially infea The heavy metal adsorbing resin has the advantage of sible because of the defect that not only the exchange being able to be regenerated by treatment with an acid resin has poor ability to adsorb heavy metals, but also after the adsorption of heavy metals to regain its ad the solution treated still contains large quantities of the sorbing ability. heavy metals. The various advantages of the resin over the conven In recent years, methods have been proposed to ad 25 tional chelate resins cannot be ascribed to any clear sorb heavy metals using a chelate resin, but almost all cause. However, we assume that such advantages are of them have not proved satisfactory for industrial ap ascribable to the fact that the main chain of the resin plication. For example, a condensation-type chelate consists of an aliphatic hydrocarbon skeleton (the so resin obtained by reacting thiourea, resorcinol and for called polymerized type high-molecular-weight poly maldehyde is considered best suited for use in such a 30 mer) and the specific functional group bonded thereto method. However, the condensation-type chelate resin synergistically acts to provide a chelating adsorbing has the defect that its ability to adsorb heavy metals is power or other adsorbing power. not entirely satisfactory, its mechanical strength is The base of the heavy metal adsorbing resin of this poor, and it is difficult to regenerate with acid after ad invention may be any of which the main chain consists sorption of heavy metals. 35 of a polymerized-type high-molecular-weight polymer Accordingly, heavy metal adsorbing resins of better having a carbon-to-carbon bond and may be a known quality have been desired in the art. homopolymer, copolymer or graft copolymer. Typical An object of this invention is to provide a resin which examples of such polymers than can be suitably used has a high ability to adsorb heavy metals and high me include polymers of olefins such as polyethylene, poly chanical strength, and which can be easily regenerated. 40 propylene, polybutene, polybutadiene or polyisoprene Another object of this invention is to provide a resin and copolymers of olefins; copolymers of olefins with which distinctly discolors upon adsorption of heavy other copolymerizable monomers such as vinyl chlo metals. ride, vinylidene chloride, an acrylic acid ester or a The othere objects and the advantages of this inven methacrylic acid ester; polymers of unsaturated ali tion will become apparent from the following descrip 45 phatic halogenated hydrocarbons such as vinyl chlo tion. ride, vinylidene chloride, vinylidene chloride or chloro According to this invention, there is provided a heavy prene; copolymers of the aforesaid unsaturated ali metal adsorbing resin of which the main chain consists phatic halogenated hydrocarbons with other copoly of an aliphatic hydrocarbon skeleton and which con merizable monomers such as an olefin, vinyl ester, vinyl tains at least one functional group selected from the 50 ether, acrylonitrile, acrylic acid ester or methacrylic group consisting of amino, polyalkylene polyamino, hy acid ester; polymers of acrylonitrile, acrylic acid esters drazido, thioureido, thiosemicarbazido, thiocyanato, or methacrylic acid esters; polymers of styrene or sty thiobiuret, N-thioaminobiuret, and N-thiocarbamoyl rene derivatives; copolymers of the aforesaid styrene polyalkylene amino groups. monomers with other copolymerizable monomers such The heavy metal adsorbing resin of this invention has 55 as acrylonitrile or a methacrylic acid ester; and graft a markedly high speed of adsorption of heavy metals as copolymers obtained by grafting the aforementioned compared with the conventional chelate resins, and can monomers to rubbery substances such as a polyalkyl adsorb heavy metals almost completely from a solution ene oxide, polybutadiene, ethylene/propylene copoly containing them in low concentrations. Accordingly, mer or ethylene/propylene?diene terpolymer. Espe when the heavy metal adsorbing resin is contacted with 60 cially when a polymer, copolymer or graft copolymer a solution containing heavy metals, the treated solution of the unsaturated aliphatic halogenated hydrocarbon has very low concentrations of the heavy metals, and is used as the resin base, the introduction of the func the concentrations are constant until the resin has ad tional group is easy, and the resulting heavy metal ad sorbed the heavy metals and almost reached saturation. 65 sorbing resin exhibits very superior advantages. Such a characteristic of the heavy metal adsorbing It is essential in the present invention that the main resin of this invention is quite different from that of the chain of the heavy metal adsorbing resin consists of the conventional condensation-type chelate resin whose aliphatic hydrocarbon skeleton, and at least one func 3,892,688 3 4 tional group selected from amino, polyalkylene poly granules is 10 to 300 mesh, preferably 15 to 50 mesh. amino, hydrazido, thioureido, thiosemicarbazido, iso Below are given some examples of reactions that can thiocyanato, thiobiuret, N-thioaminobiuret and be suitably used for producing the heavy metal adsorb N-thiocarbamoyl-polyalkylene polyamino group is di ing resins of this invention. rectly or indirectly attached to the main chain. 5 1. A hypohydrohalous acid salt is reacted in alkali All resins containing the aforementioned functional with a high-molecular-weight polymer (to be referred groups have excellent ability to adsorb heavy metals. to simply as a base polymer) of which the main chain Those containing at least one nitrogen-containing func consists