CA1128228A - Polyolefine films for large crop agricultural uses - Google Patents
Polyolefine films for large crop agricultural usesInfo
- Publication number
- CA1128228A CA1128228A CA323,579A CA323579A CA1128228A CA 1128228 A CA1128228 A CA 1128228A CA 323579 A CA323579 A CA 323579A CA 1128228 A CA1128228 A CA 1128228A
- Authority
- CA
- Canada
- Prior art keywords
- film composition
- films
- polyolefin
- microns
- weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K17/00—Soil-conditioning materials or soil-stabilising materials
- C09K17/52—Mulches
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
- A01G9/00—Cultivation in receptacles, forcing-frames or greenhouses; Edging for beds, lawn or the like
- A01G9/14—Greenhouses
- A01G9/1438—Covering materials therefor; Materials for protective coverings used for soil and plants, e.g. films, canopies, tunnels or cloches
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/30—Sulfur-, selenium- or tellurium-containing compounds
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
- Y02A40/10—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in agriculture
- Y02A40/25—Greenhouse technology, e.g. cooling systems therefor
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Soil Sciences (AREA)
- Materials Engineering (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Environmental Sciences (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Greenhouses (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A polyolefin film composition having incorporated therein a mineral salt such as alunite and hydrated alumina to provide a low transmittance of the spectrum in the range of 7 to 14 microns.
A polyolefin film composition having incorporated therein a mineral salt such as alunite and hydrated alumina to provide a low transmittance of the spectrum in the range of 7 to 14 microns.
Description
- ~L2822~
Polyolefin films, particularly low density polyethylene and EVA co-polymer, are widely ussd all over the world as co~er for protecting crops in the form of mulching, tunnels and particularly greenhouses.
These polyolefin ilms have Serious drawbacks for these applications and could be summarized as follows:
a) They are permeable to long wave infra-red radiation particularly within the range of between approximately 7 and 14 microns ~.7.10 6 and 14.10 6m) which is precisely the area of greatest transmission of the dry atmosphere. Consequently the covers or greenhouses covered with these films loose consider-able heat through radiation, particularly on clear nights when the earth and the plants act as a low temperature black body transmitter, causing the phenomenon known as thermic inversion to occur when the termpature inside the cover or greenhouse can be a few degrees centigrade lower than on the outsi.de producing frosts or increasing the costs of the necessary energy when the cover or greenhouse is heated artificially.
b) These films are poor light diffusers creating areas of deep shadow inside the covers or greenhouses produced by the structural support and the plants themselves.
c) These films are permeable to ultra violet radiation ~;
and therefore provide no protection from the harmful effects o~ this form of radiation on the plants.
Reference may be had ko the following art:
1) French Patent 1,574,088 (April 16, 1968)
Polyolefin films, particularly low density polyethylene and EVA co-polymer, are widely ussd all over the world as co~er for protecting crops in the form of mulching, tunnels and particularly greenhouses.
These polyolefin ilms have Serious drawbacks for these applications and could be summarized as follows:
a) They are permeable to long wave infra-red radiation particularly within the range of between approximately 7 and 14 microns ~.7.10 6 and 14.10 6m) which is precisely the area of greatest transmission of the dry atmosphere. Consequently the covers or greenhouses covered with these films loose consider-able heat through radiation, particularly on clear nights when the earth and the plants act as a low temperature black body transmitter, causing the phenomenon known as thermic inversion to occur when the termpature inside the cover or greenhouse can be a few degrees centigrade lower than on the outsi.de producing frosts or increasing the costs of the necessary energy when the cover or greenhouse is heated artificially.
b) These films are poor light diffusers creating areas of deep shadow inside the covers or greenhouses produced by the structural support and the plants themselves.
c) These films are permeable to ultra violet radiation ~;
and therefore provide no protection from the harmful effects o~ this form of radiation on the plants.
Reference may be had ko the following art:
1) French Patent 1,574,088 (April 16, 1968)
2) Patent of Addition to French Patent 1,574,088 (January 15, 1973).
3) Japanese Patent 7,213,853 (May 15, 1968)
4) Belgian Patent 845,925 ~.September 9, 1975)
5) Japanese Patent J.5-1074-846 (December 18, 1974)
6) Japanese Patent J.5-0088-147 (November 8, 1973) - -, :
~:~L28Z2~
By this art it is known that by adding to these polyolefin films products such as silica, alumina silicate or aluminum hydroxiae, transmittance in the area o the spectrum of between 7 and 14 microns is conslderably reduced as well a~
increasing the strength o light diffusion, but these products have, among others, the following drawbacks:
a) Both silica and alumina silicates are generally very abrasive causing serious problems of wear in the e~uipment for preparing the composition and also in the manufacture of the film.
; b~ The commercially known silica and aluminum silicates have the effect of accelerating degradation of these films thus further worsening the problem.
c) Aluminum hydroxide presents none of these problems but it has only an absorption effect in wave lengths over 10 microns (10.10 6m) which, on a practical level, means that it is only really effective when mixed with silica or aluminium siIicate and thus the above problems cannot be avoided.
It is also known that ethylene and vinyl acetate co-polymer-films (EVA co-polymeri tend to increase their absorption in the area of the spectrum between 7 and 14 microns as the vinyl acetate content is increased but light diffusion efects ; are very low irrespective of vinyl acetate content.
The purpose of this present invention is to solve the earlier problems by providing a composition making up at least 80~ in weight preferably 90 to 97%-of a polyolefinj in particular a polyethylene or ethylene and vinyl acetate co-polymer, to which is incorporated, by the methods which will be described later, a blend of two components, the total weight content of which is between l to 15% b~t preferably between 3 to 10%.
These components are the following:
- A double basic sulphate having the following ~L1;Z 82Z~
emperical formula:
(SO4)4M6111 . M21 12 (OH~
which may also contain some SO3 or H2O and wherein Ml11 is a trivalent metal and Ml a monovalent metal.
The minerals known as aluni~e, natroalunite, jarosite, natrojarosite etc. meet this ~ormula. Hillerbrand and Pen~ield give the following as a constitutional formula for alunite:
OH OH
~ Al - O - s - O - Al ~
OH'" / ~ \ ~ OH
O O O
OH
10 `Al-O ~ K \ S~ o OH
O// \ / ~ O - Al OH ~ ¦ ~ OH
~ Al - S - O - Al OH''' - OH
These compounds have good absorption in the area of the spectrum between approximately 7 and 10 microns (7. 10 6 10. 10 6m), they are insoluble in water, compatible with the polyolefins and very stable in the temperature ranges used in the preparation and manufacture of polyolefin films.
- An aluminum hydroxide Al(O~)3 normally known as hydrated alumina and shown as A12O3 . 3H2O, which gives low transmittance in the area of the spectrum between approximately 10 and 14 microns (10. 10 6 _ 14. 10 6m).
When this blend of product is incorporated into the polyolefins a very low transmittance is achieved in the infra-red spectrum between 7 and 14 microns (7. 10 6 _ 14. 10 6m), ; the range that corresponds to the maximum transmission of the dry atmosphere.
These products should be used as finely ground powder preferably with an average particle si~e of between 1 and 15 microns (1. 10 6 and 15. 10~6m).
.
1~28;22~3 It has ~een found that blends of polyolefins containing the above products have the following ad~antages over known systems based on silica, alumina silicates or blends of both with aluminium hydroxiae:
- They have no adverse eect on khe degradation of polyethylene and EVA co-polymer ilms which is very important for the present application wherein the films are exposed to all types of weathers.
- They have very little abrasive mess which is also an important factor as both the compound and the films are manufactured in equipment normally used in the plastics industry and such suffer severe wear when abrasive blends are used.
Another objective of this invention is to include a W radiation filter in the proportion of 0,05 to 2% but preferably of 0,1 to 0,6%. By partially absorbing the UV
radiation, these films inhibit the adverse effect of this radiation on the plants, increasing crop growth. Among the products that absorb UV radiation are included the benzophenone family and the benzotriazoles.
As well as those additives which are the object of this invention, others with known effect can be incorporated such as anti-oxidants, W stabilizers, humectants, anti-static agents, etc.
All of these addi~ives may readily be incorporated i}ltO the polyolefins by any of the known systems of compound manufacture although it is recommended to employ high shear equipment, Banbury ~ type internal blenders, Buss-ko-knetter or Werner Pfleiderer ~ type continuous blenders etc., or mill ` 30 cylinders in order to achie~e a good dispersion of the mineral products. Once the composition has been prepared, the agricultural film may be manufactured by any o the known -1~28ZZ8 methods such as calendering, casting or tubular film, this latter procedure being preferable.
Polyole~in films manufactured with the composition described herein have, amonyst othexs, ~he ~ollowing advankage~:
- They are quite opaque to radiation in the spectrum range of from between 7 and 14 microns (7. 10 6 and 14. 10 6m) which act to provide reduction in heat loss in the greenhouse or cover and consequently lessens the risk of frost.
- They are relatively opaque to W radiation which acts to considera~ly reduces the adverse effect on plants.
- They are excellent light diffusers, reducing the shadow inside the greenhouse caused by the structural support and by the plants themselves.
- They are highly transparent to the radiation of visible light and short wave infra-red which is fundamental in order to get the greenhouse effect.
- Their mechanical strength is practically equivalent to that of the films normally used for this application made of polyolefins without ~illers.
- As it starts from a composition that can be considered non-abrasive, the manufacture of the films by traditional methods presents no problem.
For all the above reasons, the films for agricultural uses describedLn this invention have the pxoperty as has been demonstrated in a number of expariments using them, of - increasing the early development of plants and crop growth in comparison to polyolefin films without illers and this results in a considerable increase in productivity.
The following examples are an illustration of this:
; Example No. 1 A series of compositions based on low density ~Z~3Z~8 polyethylene having a melt flow index o 0,3 gr/10 min. and containing variable quantities of alunite and aluminium hydroxide such that the total o both was always 5% were placed in mill cylinders. ~nploying ilms of a 0,150 I~m thickness manufactured by the tubular process, measurements were taken o visible light transmission, percentage of transmittance in the area of the spectrum between 1450 and 730 cm l (approximately between 7 and 14 microns~, percentage of transmission of the energy emitted by the black body at 10C
in the area of the spectrum between 1450 and 730 cm l, this latter corresponding to that of the transparency of the dry atmosphere and between 1500 and 400 cm 1 which is more than 90~ of the total energy emitted by the ~lack body. Finally, the light dispersion was also measured as a percentage of light transmitted and dispersed at an angle over 8 above the impinging ray. The results are shown in Table l. As a reference, a sample having no iller additives and another sample containing 5% silica were also prepared.
Example No. 2 To measure the abrasive effect of compositions of various formulations containing 80% polyethylene and 20%
different mineral illers, the films were extruded in an ` extruder with a special part attached to ~he end of the screw.
The abrasive effect was determined on the basis of weight loss in the metallic attachment during an extrusion cycle of 500 hours. The results are as follows:
Sample Wei~ht loss in 500 hr cycle 20% silica Celite ~ - 499 0,026 gr.
10% of (OE)3Al. 10% alunite 0,010 gr.
20% TiO2 rutile type ~control) 0,010 gr.
.Z8ZZE~
Example No. 3 To measure the effect of various mineral illers on the aging of polyolefin films, various films having a thiakness of 0,150 mm based on LDP~ with a melt ~low index of 0,3 gr/10 min. containing 5% mineral filler and no UV stabilizer were prepared. They were exposed to natural aging in the sun under identical conditions. Degradation of the films was determined by the number of hours re~uired to achieve a 0,2% level of carbonyl groups. The results are shown in Table 2 which clearly demonstrate the superiority o additives used in this invention against the various types of silica and aluminium silicate.
Example No. 4 To determine the effect on plants, three agronomically identical greenhouses were set up having a surface of approxi-mately 500 m2. The greenhouses were covered with natural polyethylene films without fillers (Greenhouse 1) polyethylene with 0,4~ of a W light absorber of the benzophenone type (Greenhouse 2) and finally a film demonstrating this invention containing 3% alunite, 2~ (,OH)3Al and 0,4~ UV absorber (Greenhouse 3). Temperatures, early developmen~ and production of various types of plants and profitability of the greenhouses were recorded. The results are shown in Table 3.
-~ The average minimum temperatures were approximately 2C
higher in Greenhouse 3 than in No. 1 and No. 2 and the ; mechanical strength of the films was in all cases sufficiently good to withstand winds of up to 100 Km/hour.
~28Z~28 o ~
o ~o .,~ ~oo ~1 A o~O O ~ 11 Il ) 00 0 0 .,1.~
____ .. _ _ ,, a~
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'E~ rl ~ O ~r In Ul U~ C~ a~ o ~ ~o a~ o~ co co co o~ n ~b ~ ~ ~ ~ o C~ o o ~ o O I:~Q ~
~ ~, m ~
O ~ Q '1n~l o o~o ~b ~ ~ U ~ o o U~ ~ .,, ~ ~
~ a: ~ _ _ H Il) ~ ~o~
~ ~ ~ U9 In O ~ ~ o O~o H r~ N ~ t~l ~ t~l ~ tY~
p:; R~
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~,' ~ ~ ~ I I I ~
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o Lr~ u, ~n Ln In ~ Ll~
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æ ~ o O o O O ~ C ~ :
~ O ~ ~
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~:~L28Z2~
By this art it is known that by adding to these polyolefin films products such as silica, alumina silicate or aluminum hydroxiae, transmittance in the area o the spectrum of between 7 and 14 microns is conslderably reduced as well a~
increasing the strength o light diffusion, but these products have, among others, the following drawbacks:
a) Both silica and alumina silicates are generally very abrasive causing serious problems of wear in the e~uipment for preparing the composition and also in the manufacture of the film.
; b~ The commercially known silica and aluminum silicates have the effect of accelerating degradation of these films thus further worsening the problem.
c) Aluminum hydroxide presents none of these problems but it has only an absorption effect in wave lengths over 10 microns (10.10 6m) which, on a practical level, means that it is only really effective when mixed with silica or aluminium siIicate and thus the above problems cannot be avoided.
It is also known that ethylene and vinyl acetate co-polymer-films (EVA co-polymeri tend to increase their absorption in the area of the spectrum between 7 and 14 microns as the vinyl acetate content is increased but light diffusion efects ; are very low irrespective of vinyl acetate content.
The purpose of this present invention is to solve the earlier problems by providing a composition making up at least 80~ in weight preferably 90 to 97%-of a polyolefinj in particular a polyethylene or ethylene and vinyl acetate co-polymer, to which is incorporated, by the methods which will be described later, a blend of two components, the total weight content of which is between l to 15% b~t preferably between 3 to 10%.
These components are the following:
- A double basic sulphate having the following ~L1;Z 82Z~
emperical formula:
(SO4)4M6111 . M21 12 (OH~
which may also contain some SO3 or H2O and wherein Ml11 is a trivalent metal and Ml a monovalent metal.
The minerals known as aluni~e, natroalunite, jarosite, natrojarosite etc. meet this ~ormula. Hillerbrand and Pen~ield give the following as a constitutional formula for alunite:
OH OH
~ Al - O - s - O - Al ~
OH'" / ~ \ ~ OH
O O O
OH
10 `Al-O ~ K \ S~ o OH
O// \ / ~ O - Al OH ~ ¦ ~ OH
~ Al - S - O - Al OH''' - OH
These compounds have good absorption in the area of the spectrum between approximately 7 and 10 microns (7. 10 6 10. 10 6m), they are insoluble in water, compatible with the polyolefins and very stable in the temperature ranges used in the preparation and manufacture of polyolefin films.
- An aluminum hydroxide Al(O~)3 normally known as hydrated alumina and shown as A12O3 . 3H2O, which gives low transmittance in the area of the spectrum between approximately 10 and 14 microns (10. 10 6 _ 14. 10 6m).
When this blend of product is incorporated into the polyolefins a very low transmittance is achieved in the infra-red spectrum between 7 and 14 microns (7. 10 6 _ 14. 10 6m), ; the range that corresponds to the maximum transmission of the dry atmosphere.
These products should be used as finely ground powder preferably with an average particle si~e of between 1 and 15 microns (1. 10 6 and 15. 10~6m).
.
1~28;22~3 It has ~een found that blends of polyolefins containing the above products have the following ad~antages over known systems based on silica, alumina silicates or blends of both with aluminium hydroxiae:
- They have no adverse eect on khe degradation of polyethylene and EVA co-polymer ilms which is very important for the present application wherein the films are exposed to all types of weathers.
- They have very little abrasive mess which is also an important factor as both the compound and the films are manufactured in equipment normally used in the plastics industry and such suffer severe wear when abrasive blends are used.
Another objective of this invention is to include a W radiation filter in the proportion of 0,05 to 2% but preferably of 0,1 to 0,6%. By partially absorbing the UV
radiation, these films inhibit the adverse effect of this radiation on the plants, increasing crop growth. Among the products that absorb UV radiation are included the benzophenone family and the benzotriazoles.
As well as those additives which are the object of this invention, others with known effect can be incorporated such as anti-oxidants, W stabilizers, humectants, anti-static agents, etc.
All of these addi~ives may readily be incorporated i}ltO the polyolefins by any of the known systems of compound manufacture although it is recommended to employ high shear equipment, Banbury ~ type internal blenders, Buss-ko-knetter or Werner Pfleiderer ~ type continuous blenders etc., or mill ` 30 cylinders in order to achie~e a good dispersion of the mineral products. Once the composition has been prepared, the agricultural film may be manufactured by any o the known -1~28ZZ8 methods such as calendering, casting or tubular film, this latter procedure being preferable.
Polyole~in films manufactured with the composition described herein have, amonyst othexs, ~he ~ollowing advankage~:
- They are quite opaque to radiation in the spectrum range of from between 7 and 14 microns (7. 10 6 and 14. 10 6m) which act to provide reduction in heat loss in the greenhouse or cover and consequently lessens the risk of frost.
- They are relatively opaque to W radiation which acts to considera~ly reduces the adverse effect on plants.
- They are excellent light diffusers, reducing the shadow inside the greenhouse caused by the structural support and by the plants themselves.
- They are highly transparent to the radiation of visible light and short wave infra-red which is fundamental in order to get the greenhouse effect.
- Their mechanical strength is practically equivalent to that of the films normally used for this application made of polyolefins without ~illers.
- As it starts from a composition that can be considered non-abrasive, the manufacture of the films by traditional methods presents no problem.
For all the above reasons, the films for agricultural uses describedLn this invention have the pxoperty as has been demonstrated in a number of expariments using them, of - increasing the early development of plants and crop growth in comparison to polyolefin films without illers and this results in a considerable increase in productivity.
The following examples are an illustration of this:
; Example No. 1 A series of compositions based on low density ~Z~3Z~8 polyethylene having a melt flow index o 0,3 gr/10 min. and containing variable quantities of alunite and aluminium hydroxide such that the total o both was always 5% were placed in mill cylinders. ~nploying ilms of a 0,150 I~m thickness manufactured by the tubular process, measurements were taken o visible light transmission, percentage of transmittance in the area of the spectrum between 1450 and 730 cm l (approximately between 7 and 14 microns~, percentage of transmission of the energy emitted by the black body at 10C
in the area of the spectrum between 1450 and 730 cm l, this latter corresponding to that of the transparency of the dry atmosphere and between 1500 and 400 cm 1 which is more than 90~ of the total energy emitted by the ~lack body. Finally, the light dispersion was also measured as a percentage of light transmitted and dispersed at an angle over 8 above the impinging ray. The results are shown in Table l. As a reference, a sample having no iller additives and another sample containing 5% silica were also prepared.
Example No. 2 To measure the abrasive effect of compositions of various formulations containing 80% polyethylene and 20%
different mineral illers, the films were extruded in an ` extruder with a special part attached to ~he end of the screw.
The abrasive effect was determined on the basis of weight loss in the metallic attachment during an extrusion cycle of 500 hours. The results are as follows:
Sample Wei~ht loss in 500 hr cycle 20% silica Celite ~ - 499 0,026 gr.
10% of (OE)3Al. 10% alunite 0,010 gr.
20% TiO2 rutile type ~control) 0,010 gr.
.Z8ZZE~
Example No. 3 To measure the effect of various mineral illers on the aging of polyolefin films, various films having a thiakness of 0,150 mm based on LDP~ with a melt ~low index of 0,3 gr/10 min. containing 5% mineral filler and no UV stabilizer were prepared. They were exposed to natural aging in the sun under identical conditions. Degradation of the films was determined by the number of hours re~uired to achieve a 0,2% level of carbonyl groups. The results are shown in Table 2 which clearly demonstrate the superiority o additives used in this invention against the various types of silica and aluminium silicate.
Example No. 4 To determine the effect on plants, three agronomically identical greenhouses were set up having a surface of approxi-mately 500 m2. The greenhouses were covered with natural polyethylene films without fillers (Greenhouse 1) polyethylene with 0,4~ of a W light absorber of the benzophenone type (Greenhouse 2) and finally a film demonstrating this invention containing 3% alunite, 2~ (,OH)3Al and 0,4~ UV absorber (Greenhouse 3). Temperatures, early developmen~ and production of various types of plants and profitability of the greenhouses were recorded. The results are shown in Table 3.
-~ The average minimum temperatures were approximately 2C
higher in Greenhouse 3 than in No. 1 and No. 2 and the ; mechanical strength of the films was in all cases sufficiently good to withstand winds of up to 100 Km/hour.
~28Z~28 o ~
o ~o .,~ ~oo ~1 A o~O O ~ 11 Il ) 00 0 0 .,1.~
____ .. _ _ ,, a~
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~ ~, m ~
O ~ Q '1n~l o o~o ~b ~ ~ U ~ o o U~ ~ .,, ~ ~
~ a: ~ _ _ H Il) ~ ~o~
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p:; R~
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~,' ~ ~ ~ I I I ~
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:` ~ - z~o ::~
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D ~ 13 ~ .C ~ ~ ~ J;~ J~
; i ~ b
Claims (8)
1. A film composition containing at least 80% by weight of a polyolefin, said composition having incorporated therein from 1 to 15% by weight of a blend of a basic metallic sulphate having the formula (SO4)4M?M? 12(OH) wherein M''' a trivalent metal and M' is a monovalent metal and an aluminum hydroxide.
2. The film composition of claim 1 wherein the polyolefin is selected from the group polyethylene and poly-ethylene-vinyl acetate co-polymers.
3. The film composition of claims 1 or 2 wherein the polyolefin is present in the range of 90 to 97% by weight.
4. The film composition of claim 1 or 2 wherein the basic metallic sulphate may also contain molecules of SO3 and H2O.
5. The film composition of claim 1 or 2 wherein the aluminum hydroxide is hydrated alumina of the formula Al2O3 ? 3H2O.
6. The film composition of claim 1 or 2 wherein the transmittance in the spectrum range of between 7 and 14 microns.
7. The film composition of claim 1 or 2 which includes from 0.05 to 2% of a UV absorber.
8. The film composition of claim 1 or 2 wherein the basic metallic sulphate is selected from the group alunite, natroalunite, jarosite or natrojarosite.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR78/07759 | 1978-03-17 | ||
| FR7807759A FR2419955A1 (en) | 1978-03-17 | 1978-03-17 | POLYOLEFIN FILMS INTENDED TO BE USED IN AGRICULTURE |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1128228A true CA1128228A (en) | 1982-07-20 |
Family
ID=9205933
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA323,579A Expired CA1128228A (en) | 1978-03-17 | 1979-03-16 | Polyolefine films for large crop agricultural uses |
Country Status (4)
| Country | Link |
|---|---|
| CA (1) | CA1128228A (en) |
| ES (1) | ES478618A1 (en) |
| FR (1) | FR2419955A1 (en) |
| PT (1) | PT69364A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6589450B1 (en) | 1997-11-25 | 2003-07-08 | Ljubov Robertovna Bratkova | Light-converting material and composition for producing the same |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3390545C2 (en) * | 1983-10-31 | 1989-09-14 | Inst Obschei I Neoorganichesko | Polymeric material for covering greenhouses |
| US4651467A (en) * | 1984-01-13 | 1987-03-24 | Alcudia, Empresa Para La Industria Quimica, S.A. | Method for protecting plants using polymeric film containing anhydrous borax |
| RU2407770C2 (en) | 2007-03-09 | 2010-12-27 | Общество с ограниченной ответственностью Научно-производственная фирма "СВЕТ" | Light-converting material and composition for producing said material |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1399567A (en) * | 1963-07-30 | 1965-05-21 | Pechiney Progil Sa | Improvement in flexible plastic films for floor protection |
| FR2213954A2 (en) * | 1968-04-16 | 1974-08-09 | Ethylene Plastique Sa | Polyethylene films for agricultural use - contg. anhydrous alumino silicate filler |
| US4115347A (en) * | 1975-09-09 | 1978-09-19 | Societe Des Plastiques De Carmaux Scasar | Polyolefin compositions |
-
1978
- 1978-03-17 FR FR7807759A patent/FR2419955A1/en active Granted
-
1979
- 1979-03-14 ES ES478618A patent/ES478618A1/en not_active Expired
- 1979-03-16 PT PT69364A patent/PT69364A/en unknown
- 1979-03-16 CA CA323,579A patent/CA1128228A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6589450B1 (en) | 1997-11-25 | 2003-07-08 | Ljubov Robertovna Bratkova | Light-converting material and composition for producing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| ES478618A1 (en) | 1979-06-01 |
| FR2419955A1 (en) | 1979-10-12 |
| PT69364A (en) | 1979-04-01 |
| FR2419955B1 (en) | 1981-11-13 |
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