Corporate Introduction


Koichi Morisaki, President

Our company has grown to be a fine chemical manufacturer in over 70 years since our foundation as a chemical reagent manufacturer. Presently, we are conducting manufacturing of chemical reagents and various chemical products, and commissioned synthesis of new chemical products. All plants, Development Research Institute, Quality Assurance Department and Purchase Department have obtained ISO9001 certification for product quality control and ISO14001 certification for environmental conservation. Saitama Plant and Ibaraki Plant are equipped with GMP-corresponding buildings.

Now is the time of a progressing magnificent industrial revolution which began from IT reformation. We will continue to grow as a company which accurately understands the sense of the new era, supports environment conservation and contributes to social development.

Junsei Chemical Co.,Ltd.

Corporate overview

Foundation January 1948
Location 4-4-16 Nihonbashi-honcho, Chuo-ku, Tokyo 103-0023
Capital ¥100,000,000
Number of employees 151
Business content
Manufacturing and sales of chemical reagents and chemical products, and commissioned synthesis of chemical products
Plants Saitama, Ibaraki, Tsukuba
Branches/ offices Tohoku / Hokkaido, Toyama, Saitama, Tsukuba, Chiba, Yokohama, Osaka
Research institute Saitama
Banks of account MUFG Bank, Ltd. Mizuho Bank, Ltd. Sumitomo Mitsui Banking Corporation


January 1948 Founded at Kojima Bldg., Nihonbashi-honcho, Chuo-ku, Tokyo. Capital: ¥500,000. Started sales of chemical reagents.
October 1949 Constructed Meguro Plant in Yutenji, Meguro-ku, Tokyo.
October 1951 Constructed Nakano Plant in Numabukuro, Nakano-ku, Tokyo and started manufacturing of chemical reagents. Closed Meguro Plant.
December 1958 Constructed Headquarters building in Nihonbashi-honcho, Chuo-ku, Tokyo.
December 1963 Constructed Saitama Plant in Omano-cho, Koshigaya-City, Saitama. Closed Nakano/ Shimura Plants.
March 1965 Newly constructed a research institute within the land of Saitama Plant.
September 1966 Increased the capital to ¥100,000,000.
December 1974 Increased the capital to ¥150,000,000.
April 1980 Acquired approval of bonded warehouse by Tokyo Customs within Saitama Plant.
March 1985 Constructed Okuma Plant in Ottozawa, Okuma-machi, Fukushima Pref. and expanded production ability of fine chemicals.
March 1988 Constructed Tsukuba Plant in Takasai, Shimotsuma-City, Ibaraki Pref. and expanded production ability of chemical reagents.
March 1994 Constructed the second synthesis building at Okuma Plant.
May 1995 Constructed an electronic industrial medicine manufacturing building within Saitama Plant.
August 1996 Newly constructed manufacturing facility corresponding GMP in the second synthesis building of Okuma Plant.
December 1996 Newly constructed manufacturing facility corresponding GMP in the third manufacturing building of Saitama Plant.
December 1998 I All offices obtained ISO9001 certification for all of our products.
March 1999 Newly constructed the third synthesis building at Okuma Plant.
February 2000 Newly constructed the fourth synthesis building at Okuma Plant.
April 2001 Reconstructed the third manufacturing building at Saitama Plant and constructed a four-story chemical product manufacturing building.
March 2002 Headquarters, 3 plants and all offices obtained ISO14001 certification.
October 2003 Constructed a medicine manufacturing facility and trial manufacture facility in the third synthesis building at Okuma Plant.
October 2004 Established a joint venture company of chemical product manufacturing in Changshu-City, Jiangsu Province, China.
December 2004 Newly constructed the first manufacturing office and administration building at Saitama Plant.
July 2005 Newly constructed the fifth synthesis building at Okuma Plant.
February 2007 Newly constructed the sixth synthesis building at Okuma Plant.
August 2008 Expansion of Inspection Section of Okuma Plant.
March 2011 Okuma plant is occurred by East Japan great earthquake disaster and nuclear plant accident and closed just after constructed the seventh composition ridge.
March 2013 Ibaraki Factory start as a substitute factory of the Okuma factory in Nakagocho, Ibaraki and customized synergy service began.
March 2013 Constructed Ibaraki Plant as a substitute of Okuma plant in Nakago-machi, Ibaraki Pref and Commissioned Manufacturing of Chemical Product service began.
March 2016 Completed the second phase construction at Ibaraki Plant, Constructed the third synthesis building and Contracted synthesis service began.
February 2018 reduced the capital to ¥100,000,000.
March 2022 Completed the third phase construction at Ibaraki Plant, Constructed the fourth synthesis building and Contracted synthesis service began.


  • Headquarters

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    4-4-16 Nihonbashi-honcho, Chuo-ku, Tokyo 103-0023

    Management Headquarters
    Administration Department
    Accounting Department

    TEL 03-3270-5412 FAX 03-3270-5525

    Chemical Products Department

    TEL 03-3270-5424 FAX 03-3270-5418
  • Saitama Office

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    1-6 Omano-cho, Koshigaya-City, Saitama Pref. 343-0844

    Sales Headquarters

    TEL 048-988-3621 FAX 048-988-6689

    Trade Department

    TEL 048-988-8714 FAX 048-988-3480

    Sales Section1

    TEL 048-988-3611 FAX 048-988-8713

    Sales Section2

    TEL 048-988-6161 FAX 048-988-6689

    Purchase Department

    TEL 048-988-8711 FAX 048-988-8712
  • Saitama Plant

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    • Details

      • Production Department
        Development Research Institute - Proposals of lab-scale, literature researches, synthetic schema. Production Technology Section -Lab scale-500L reaction scale
        -1,000L-4,000L reaction scale
        -Production by multi facilities
        -Scale-up consideration by pilot facility
        -GMP facility
        Main facilities
        Reaction tank (GL) 30-4,000L 37 units
        Reaction tank (SUS) 30・・,500L 8 units
        Reaction tank (Hastelloy) 150・・,000L 3 units
        Mixing tank (plastic)   many
        Centrifuge (SUS) 24-42in.
        7 units
        Filtration machine   7 units
        -Conical dryer (GL) 650・・50L 2 units
        -Shelf type (SUS)   2 units
        -Vibrating type (SUS/Teflon-lining)   1 unit
        Clean room: class 100,000   2 rooms
        Clean booth clean bench many
        Analytical instruments
        Gas chromatography (including capillary-use-only) 7
        Liquid chromatography 10
        Ion chromatography 5
        Gas chromatography mass spectroscope 1
        Fourier transform infrared spectrophotometer 1
        Spectrophotometer 1
        Atomic absorption photometer (frame, non-frame) 2
        X-ray fluorescence spectrometer 1
        ICP mass spectroscope 1
        ICP emission spectrophotometer 1
        Polarimeter 1
        NMR・・00MHz・・/td> 1
        Particle size distribution measuring instrument (Micro Truck) 1
        Surface area measuring instrument 1
        Karl Fischer (volume, coulometry, moisture vaporization instrument) 3
        Automatic titrator 2
        Viscometer (E-type, B-type) 3
        Polarimeter 1
        Particle counter 1
        Colony counte 1
        Colony analyzer system 1
    1-6 Omano-cho, Koshigaya-City, Saitama Pref. 343-0844
    TEL 048-986-6161 FAX 048-989-2787
    Manufacturing items: Chemical reagents and manufacturing of small and middle-sized chemical products
    Saitama Plant
    -Management Section
    -Production Technology Section
    -Reagent Section
    Quality Assurance Department
    -Inspection Section
    Development Research Institute
  • Tsukuba Plant

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    1417 Takasai, Shimotsuma-City, Ibaraki Pref. 304-0031
    TEL 0296-45-0711 FAX 0296-45-0713
    Manufacturing item: Manufacturing of liquid reagents
    -Management Section -Production Technology Section -Inspection Section
  • Ibaraki Plant

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    • Details

      • Production Department
        Production Technology Section Consideration for scale-up of mass products, production method improvement, facilities, etc of Ibaraki Plant 1,000L~20,000L reaction scale
        Main facilities
        Reaction tank (GL) 10,000L 12 units
        20,000L 1 units
        1,000L 3 units
        Receiver (GL) 800L~15,000L 16 units
        Reaction tank (SUS316)
        *First class pressure vessel, high temperature〔250℃〕
        10,000L 2 unit
        Receiver (SUS316) 8,000L 2 unit
        Reaction tank (SUS316) 10,000L 1 unit
        Condenser (SUS) 4m2 ~15m2 7 units
        Condenser (carbide) 5m2 ~30m2 16 units
        Filtration machine (SUS) 1m2 ~10m2 4 units
        Centrifuge (SUS) 48in. 3 units
        Centrifuge (SUS) 60in. 1 units
        Conical dryer(GL) 150L 1 unit
          4,000L 3 units
          6,000L 1 units
        Analytical instruments
        GC(head space included) 4
        HPLC 9
        Infrared spectrophotometer 1
        Ultraviolet visible spectrophotometer 1
        Viscosity measuring device 1
        Viscosity meter Type B 1
        pH meter 1
        Particle-size-distribution meter (0.02~700μm) 1
        Automatic melting point measuring instrument 1
        Density hydrometer 1
        Automatic titrator 1
        Stability-chambers 3
        Karl Fischer moisture titrate 2
        Electric furnace 1
    644-47 Hitana-aza-houtubo, Nakagou-machi, Kitaibaraki-City, Ibaraki Pref. 319-1556
    TEL 0293-42-7261 FAX 0293-42-7262
    Manufacturing item: Manufacturing of large-scale chemical products
    -Management Section -Production Technology Section -Inspection Section
  • Tohoku Branch

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    1-2-3 Oroshi-machi, Wakabayashi-ku, Sendai-City, Miyagi Pref. 984-0015


    TEL 022-283-8245 FAX 022-283-8252


    TEL 022-232-6215 FAX 022-232-6218
  • Hokkaido Office

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    5-4-21-104 Kitago-gojo, Shiroishi-ku, Sapporo-City, Hokkaido 003-0835
    TEL 011-874-0151 FAX 011-874-0148
  • Toyama Office

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    1-11-28 Namajima, Toyama-City, Toyama Pref. 930-0801
    TEL 076-433-3100 FAX 076-433-0417
  • Tsukuba Office

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    1417 Takasai, Shimotsuma-City, Ibaraki Pref. 304-0031
    TEL 0296-43-7711 FAX 0296-43-7714
  • Chiba Office

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    57-6 Kubota, Sodegaura-City, Chiba Pref. 299-0242
    TEL 0438-62-1151 FAX 0438-62-4181
  • Yokohama Office

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    3F, Tsuruta Science Bldg., 2-5-5 Kanagawa, Kanagawa-ku, Yokohama-shi, Kanagawa Pref. 221-0045
    TEL 045-620-4851 FAX 045-461-2320
  • Osaka Office

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    1F, THE AID Bldg., 6-6 Honmachibashi, Chuo-ku, Osaka-City, Osaka Pref. 540-0029
    TEL 06-6940-3091 FAX 06-6940-3092