---

Inventors:	Jakubowski; John A. (Piscataway, NJ)
Assignee:	Calgon Corporation (Pittsburgh, PA)
Appl. No.:	679430
Filed:	December 7, 1984

---

---

3300375	Jan., 1967	Webner	514/516.
3524871	Aug., 1970	Matt	260/454.
3644380	Feb., 1972	Harmetz et al.	260/294.
3833731	Sep., 1974	Grier et al.	71/67.
3833743	Sep., 1974	Morse et al.	426/195.
3873597	Mar., 1975	Harmetz et al.	260/465.
3877922	Apr., 1975	Grier et al.	71/67.
3929585	Dec., 1975	Swigert	260/465.
3996378	Dec., 1976	Payton	514/516.

Primary Examiner: Robinson; Allen J.
Attorney, Agent or Firm: Mitchell; William C., Olson; R. Brent, Sudol, Jr.; Michael C.
 

---

---

What is claimed is:

1. A method of inhibiting microbial growth, wherein said microbial growth is selected from the group consisting of Pseudomonas stutzen, Pseudomonas Fluorescens, Pseudomonas aeruginosa, Saccharomyces cerevisiae, Aspergillus niger, Penicillivm funiculosum, Candida sp., Fusarium sp., Cephelosporium sp., Trichoderma viride, Cladosporium herbarum, Aspergillus fumigatus, Pullularia pullulans, Ceratocystic pilifera, Cephaloascus fragrans and mixtures thereof, comprising contacting said microbial growth with an effective amount of an admixture comprising:

(a) 2-bromo-2-bromomethylglutaronitrile and

(b) methylene bis(thiocyanate),

wherein the weight ratio of (a):(b) ranges from about 1:2.5 to 10:1.

2. The method of claim 1, wherein said admixture further comprises a carrier.

3. A synergistic antimicrobial admixture comprising:

(a) 2-bromo-2-bromomethylglutaronitrile and

(b) methylene bis(thiocyanate),

wherein the weight ratio of (a):(b) ranges from about 1:2.5 to 10:1.

4. The admixture of claim 3, further comprising a carrier.

---

---

BACKGROUND OF THE INVENTION

U.S. Pat. Nos. 3,833,731; 3,877,922; 3,873,597; 3,644,380; 3,833,743; and 3,929,858 (which are hereby incorporated by reference) disclose 2-bromo-2-bromomethylglutaronitrile and its use as an antibacterial, antifungal, and algicidal agent.

U.S. Pat. Nos. 3,996,378; 3,300,375; and 3,524,871 (which are hereby incorporated by reference) disclose methylene bis(thiocyanate).

Both 2-bromo-2-bromomethylglutaronitrile and methylene bis(thiocyanate) are known individually as antimicrobial agents. The unexpected finding of the instant invention is that they are synergistic in combination as antimicrobial agents.

DESCRIPTION OF THE INVENTION

The present invention is directed to synergistic antimicrobial admixtures comprising 2-bromo-2-bromomethyleneglutaronitrile hereinafter referred to as "BBMG") and methylene bis(thiocyanate) (hereinafter referred to as "MBT").

The present invention is also directed to a method of inhibiting microbial growth, comprising contacting said growth with an admixture of BBMG and MBT.

As used herein, the phrases "antimicrobial" and "inhibiting microbial growth" describe the killing of, as well as the inhibition of or control of the growth of bacteria, yeasts, fungi, and algae. A number of important industries can experience serious adverse effects from the activity of such bacteria and fungi on the raw materials which they employ, on various aspects of their manufacturing activities, or on the finished products which they produce. Such industries include the paint, wood, textile, cosmetic, leather, tobacco, fur, rope, paper, pulp, plastics, fuel, oil, rubber, and machine industries. Important applications of the synergistic antimicrobial combination of the present invention include: inhibiting the growth of bacteria and fungi in aqueous paints, adhesives, latex emulsions, and joint cements; preserving wood; preserving cutting oils; controlling slime-producing bacteria and fungi in pulp and paper mills and cooling towers; as a spray or dip treatment for textiles and leather to prevent mold growth; as a component of anti-fouling paints to prevent adherence of fouling organisms; protecting paint films, especially exterior paints, from attack by fungi which occurs during weathering of the paint film; protecting processing equipment from slime deposits during manufacture of cane and beet sugar; preventing microorganism buildup and deposits in air washer or scrubber systems and in industrial fresh water supply systems; controlling microorganism contamination and deposits in oil field drilling fluids and muds, and in secondary petroleum recovery processes; preventing bacterial and fungal growth in paper coating processes which might adversely affect the quality of the paper coating; controlling bacterial and fungal growth and deposits during the manufacture of various specialty boards, e.g., cardboard and particle board; preventing sap stain discoloration on freshly cut wood of various kinds; controlling bacterial and fungal growth in clay and pigment slurries of various types which are manufactured for later use in paper coating and paint manufacturing for example, and which are susceptible to degradation by microorganisms during storage and transport; as a hard surface disinfectant to prevent growth of bacteria and fungi on walls, floors, etc.; and in swimming pools to prevent algae growth. The control of bacteria and fungi in pulp and paper mill water systems which contain aqueous dispersions of papermaking fibers is especially important. The uncontrolled buildup of slime produced by the accumulation of bacteria and fungi causes offgrade production, decreased production due to breaks and greater cleanup frequency, increased raw material usage, and increased maintenance costs. The problem of slime deposits has been aggravated by the widespread use of closed white water systems in the paper industry.

Another important area where control of bacterial and fungal growth is vital is in clay and pigment slurries. These slurries are of various clays, e.g. kaolin, and pigments, e.g. calcium carbonate and titanium dioxide, and are manufactured usually at a location separate from the end use application, in for example, paper coating and paint manufacturing, and are then stored and held for later transport to the end use location. Because of the high quality standards for the paper and paint final products in which the slurry is used, it is essential that the clay or pigment slurry have a very low microorganism count or content so that it is usable in the paper coating or paint manufacturing.

The synergistic antimicrobial combination of the present invention may also be utilized for agricultural and animal health applications, for example in preventing or minimizing the growth of harmful bacterial, yeast, and/or fungi on plants, trees, fruit, seeds, or soil. The synergistic combination is especially useful in treating seed to prevent microorganism, particularly fungal attack. The synergistic combination is also useful in protecting animal dip compositions against the buildup of microorganisms, and for this purpose may be combined with a veterinary animal dip parasiticide and an acceptable carrier.

The synergistic combination of the present invention has been found especially useful in controlling the harmful effects of microorganisms in water or aqueous media. Systems which utilize circulating water or aqueous media become infected with microorganisms and experience substantial impairment of their efficiency when deposits of the microorganisms build up in the system. The deposits, called slimes, coat the walls of tanks and other vessels, and any machinery or processing equipment which is employed, and create blockages in pipes and valves. The slimes also create discolorations and other imperfections in any products being produced, forcing costly shutdowns. Control of microorganisms in aqueous media is particularly important where there are dispersed particles or fines in the aqueous media, e.g., dispersed cellulosic fibers and dispersed fillers and pigments in papermaking, and dispersed pigments in paint manufacture.