Photodegradable polyvinyl chloride compositions containing a ferrocene prodegradant
United States Patent [191 Brackman Apr. 8, 1975 1 PHOTODEGRADABLE POLYVINYL CHLORIDE COMPOSITIONS CONTAINING A FERROCENE PRODEGRADANT [75] Inventor: Derek Samuel Brackman, Stanmore,  
 [30] Foreign Application Priority Data May 18, 1972 United Kingdom 23343/72 [52] U.S. Cl ..260/92.8 R; 260/4575 R;  
  260/DIG. 43 [51] Int. Cl. C08f 3/22 [58] Fieldol Search.. 260/DIG. 43, 45.75 R, 92.8 R  
 [56] References Cited UNITED STATES PATENTS Pauson 260/4575 3,269,963 8/1966 Ilgemann et a1. 260/4575 3.676.401 7/1972 Henry 260/63 FOREIGN PATENTS OR APPLICATIONS 228,938 10/1968 U.S.S.R.  
 OTHER PUBLICATIONS Chemical and Engineering News, Vol. 39, Sep., 1961, p. 51. Chemical and Engineering News, May 1 l, 1970,  
 The Stabilization of Polyvinyl chloride,&#34; by Chevasus, St. Martens Press, Edward Arnold Publ., 1963, p. 23-27,  
 Primary Examiner-Eugene C. Rzucidlo Attorney, Agent, or F irnz-Cushman, Darby &amp; Cushman [57] ABSTRACT Polyvinyl chloride compositions contain ferrocene or a derivative as a prodegradant.  
 4 Claims, No Drawings basic blend which consisted of:  
 PHOTODEGRADABLE POLYVINYL CHLORIDE COMPOSITIONS CONTAINING A FERROCENE PRODEGRADANT This invention relates to polyvinyl chloride composi- 5 tions.  
  The use of disposable polyvinyl chloride wrappings, containers and the like and their subsequent discarding, either intentionally or accidentally. has led to a problem of plastics litter. It is an object of this invention to alleviate this problem.  
  According to the invention polyvinyl chloride compositions contain a prodegradant, said prodegradant being ferrocene or a derivative of ferrocene, e.g. 0.01 to 1%, preferably 0.05 to 0.5% by weight (based on the total composition) of the prodegradant.  
  In addition to the parent compound. i.e. ferrocene, alkyl and cycloalkyl derivatives as well as keto and ester derivatives have been found particularly useful. The alkyl and cycloalkyl ferrocenes are those in which the or each alkyl or cycloalkyl group contains from 1 to 18, preferably 4 to 5, carbon atoms. The keto ferrocenes are those in which the or each substituent takes the form of a hydrocarbon group having up to 1 1 carbon atoms joined to the ferrocene nucleus via a CO- group.  
  The invention includes wrappings (e.g. wrapping film) and containers made of the polyvinyl chloride compositions described above. The following are examples of containers: bags, sacks, boxes, cartons, bottles, sachets, cups and thermoforms.  
  As used in this specification the term polyvinyl chloride denotes not only the homopolymers of vinyl chloride but also its copolymers which contain more than 50% by weight of vinyl chloride monomers. The following are examples of monomers which can be copolymerised with vinyl chloride: vinyl esters such as vinyl acetate and vinyl stearate; vinylidene chloride; vinyl ethers such as isobutyl vinyl ether; alkyl acrylates and methacrylates such as ethyl acrylate, butyl acrylate, Z-ethyl hexyl acrylate, and methyl methacrylate; olefines such as ethylene, propylene, 4-methyl pentene- 1, dodecene- 1 and tetradecene.  
  We have found that ferrocene and its derivatives increase the rate of degradation of polyvinyl chloride compositions which contain conventional additives such as stabilisers, lubricants, dyes, pigments, impact modifiers, processing aids, fillers and blowing agents.  
  Several embodiments of the invention will now be described by way of example.  
  Seven prodegradants were used in accordance with the invention to prepare polyvinyl chloride compositions. In each case the prodegradant was added to a The seven prodegradants used were:  
 Parent Compound Prodegradant 1 Ferrocene Alkyl Derivatives The compositions were prepared by mixing each prodegradant with the basic blend to give mixtures which contained 0.1% by weight of prodegradant as stated in Table 1. These mixtures were gelled on a mill at C for 10 minutes. The crepe was compression moulded using 5 minutes pre-heat at C and 3 minutes under 20 tons per square inch pressure to give film 0.007 to 0.010 inch thick when rapidly cooled to 25C.  
  Samples 1 cm X 3 cm were cut from the pressed sheet and subjected to UV. irradiation using modified FS/BL irradiation (i.e. a combination of a fluorescent sun lamp, a Philips actinic blue and two natural daylight fluorescent lamps). The samples were maintained at a distance of 10 cms from the lamps.  
  The samples were inspected and tested for flex-crack failure at intervals of 8 to 12 hours until cracking occurred when subjected to bending stress. This cracking was taken as evidence of embrittlement. The times (in hours) required are given in Table 1.  
  In addition some of the compositions were exposed out of doors in South Africa and times (in weeks) required for the composition to become embrittled are also recorded in Table 1. The procedure was as follows.  
  Specimens of foil were mounted between Perspex (RTM) sheets with a circle 2 cm in diameter uncovered and these were exposed at 45 to the horizontal facing north in South Africa commencing in February 1972. The specimens were tested for embrittlement at weekly intervals by dropping a 3.8 g mass in the form of a 7.5 mm diameter rod onto the unexposed face of the horizontal specimen. The mass was dropped from a height of 310 mm down a vertical guide tube. Repeats with the same formulations gave identical embrittlement times.  
  The basic blend without any additive was also exposed and the times required for this composition are recorded in Table l as blanks.  
 LII  
 rocene nucleus via a CO-group.  
  2. Polyvinyl chloride compositions which contain 0.05 to 0.5% by weight based on the total composition of the prodegradant.  
  3. A container made ofa polyvinyl chloride composition according to claim 1.  
 4. Wrapping material made of a polyvinyl chloride composition according to claim 1.  
  l= l l Notice of Adverse Decision in Interference In Interference No. 99,356, involving Patent No. 3,876,598, D. S. Brackman, PHOTODEGRADABLE POLYVINYL CHLORIDE COMPOSI- TIONS CONTAINING A FERROCENE PRODEGRADANT, final judgment adverse to the patentee Was rendered Dec. 23, 1976, as to clalms 1 and 2.  
 [Ofiieial Gazette March 22, 1977.]  
 Disclaimer 3,876,598.De7&#39;ele Samuel Bmclcmem, Stanmore, England. PHOTODEGRAD- ABLE POLYVINYL CHLORIDE COMPOSITIONS CONTAIN- ING A FERROCENCE PRODEGRADANT. Patent dated Apr. 8, 1975. Disclaimer filed Sept. 23, 1976, by the assignee, Imperial Ohemz&#39;eaZ Industries Limited. Hereby enters this disclaimer toclaims 1-4 of said patent.  
 [Ofitctat Gazette March 22, 1977.]