Title: Polymeric films for use in agriculture

I claim:

1. A polymeric composition in film or sheet form, adapted to transmit a large part of incident sunlight, a substantial part thereof by forward scattering, and to reflect a large part of incident IR radiation, consisting essentially of:

a polymer or copolymer, which is generally transparent; and

micron size particles of an additive comprising 1-12% magnesium oxide and 0-8% calcium carbonate, the total combined additive being in the range of 1 to 12%, all percentages being by weight of the polymeric composition.

2. A polymeric composition in accordance with claim 1, wherein said film or sheet is in a thickness of 0.05 mm to 0.25 mm.

3. A polymeric composition in accordance with claim 1, wherein said additive consists essentially of magnesium oxide to the exclusion of calcium carbonate.

4. A polymeric composition in accordance with claim 1, wherein the ratio of MgO to CaCO₃ is in the range of 1:2 to 2:1.

5. A polymeric composition in accordance with claim 1, wherein the additive is in the form of -5μ size particles.

6. A polymeric composition in accordance with claim 1, further including an antioxidant, an anti-fog agent, and/or a UV absorber.

7. A polymeric composition in accordance with claim 1, wherein said polymer or copolymer is a polyolefin.


Other info:


Inventors: Bar, Rami (Kibbutz Ginegar, IL)

Application Number: 06/340248
Filing Date: 1982-01-18
Publication_date: 1983-12-27
Assignee: Bar, Rami (IL)

Primary Class(es): 523/135 524/425, 47/17, 47/29.400, 524/433, 524/427
Other Classes: A01G9/14; C08K3/22; C08K3/26; C08K3/00; C08K3/20; C08K3/26
US Patent Ref:

2466038	April, 1949	Lewis et al.	524/427	Polythene compositions containing calcium carbonate
3326739	June, 1967	Brennan et al.	524/425	Low gloss film
3821156	June, 1974	Farrar	524/425
3857804	December, 1974	Glatti et al.	428/220	THERMOPLASTIC FILM FOR CONTROLLING PLANT GROWTH
3884870	May, 1975	Dodson et al.	524/425	Polyethylene terephthalate film
4048208	September, 1977	Spicuzza et al.	524/433	Method for preparing improved expanded polystyrene sheet
4075784	February, 1978	Pied	524/427	Method for increasing the productive yield of crops with polyolefin films
4134875	January, 1979	Tapia	423/518	Polyolefin film for agricultural use
4179547	December, 1979	Allingham	524/417	Polyethylene sheets and films
4265960	May, 1981	Arbit et al.	524/427	Films produced from LDPE encapsulated CaCO.sub.3

Other Refs: CA712639FR1574088JP55-164238

June, 1965	524/433
July, 1969
December, 1980	523/135

Primary Examiner: Jacobs, Lewis T.
Assistant Examiner:
Attorney: Browdy, And Neimark