FR2772775A1 - Polyolefin composition for making agricultural film - Google Patents

Abstract

Resin composition comprising a polyolefin resin, basic aluminum carbonate (I) and a sterically hindered amine (II) is new. Also claimed is a film comprising at least one layer comprising a resin composition as above.

Description

 The present invention relates to a polyolefin resin composition having good heat resistance, good weather resistance, good transparency and good processability, a film comprising at least one layer containing this resin composition and the use thereof. of this film.

 Resins for outdoor use for motor vehicles, construction and agriculture are increasingly sought after, for example as agricultural films for use in covering installations such as greenhouses and greenhouses. tunnels in horticulture.

(Poly) vinyl chloride films and polyolefin resin films, such as polyethylene films and ethylene / vinyl acetate copolymer resin films, are widely used as agricultural films, and particularly resin films. polyolefin which are low in dirt, light and do not release toxic gases when burned.

 Since these agricultural films are used outdoors, if their base resin does not have satisfactory weathering resistance, the physical properties of the films, such as the retention rate of elasticity and the tensile strength, are degraded during the course of time. their use by oxidation of the resin, so that the films themselves degrade. To improve the weatherability of these films, it has been proposed to use a resin composition obtained by incorporating various weathering agents such as antioxidants and U.V. absorbers into a polyolefin resin. Among these weatherproofing agents, sterically hindered amine stabilizers are preferably used because, with them, the weatherability of the polyolefin resins can be remarkably improved by adding them even in small amounts and maintaining their effect for a period of time. a long time, and remarkably control the brightness and tint of the polyolefin resin films, as described in Japanese Patent Application Publication Nos. Sho 59-86645 and Hei 2-167350.

 Japanese Patent Application Laid-Open No. Sho 56-41254 discloses a thermoplastic resin film containing a hindered amine compound and polar inorganic fine particles having a surface area of 10 m 2 / g. Japanese Patent Laid-Open No. Sho 63-175072 discloses an agricultural film containing a thermoplastic resin, a hindered amine compound and a hydrotalcite-like compound.

 However, these films are unable to retain their mechanical properties in an environment in which they are exposed to agrochemicals and acid rain. In addition, these films may stain and form a foam during processing because of their poor thermal stability, so that their weather resistance is unsatisfactory.

 To solve these problems, the object of the present invention is to develop a polyolefin resin composition having good heat resistance and good weather resistance.

 Thus, the present invention relates to a resin composition comprising a polyolefin resin, a basic aluminum carbonate and a hindered amine compound. This resin composition may further contain a U.V absorber.

 The present invention also relates to a film comprising at least one layer constituted by the resin composition above. This film may contain an anti-fog agent or an anti-blocking agent, or a combination of these two agents. In addition, the film according to the present invention may contain a release coating.

 The present invention also relates to the use of the above film as an agricultural film and the use of the above film in an agricultural installation.

 The single figure of the accompanying drawing shows an X-ray diffraction pattern of a basic aluminum carbonate used according to the present invention.

 This basic aluminum carbonate is composed of aluminum ions, carbonate ions and at least one type of cation different from the aluminum ions.

These cations include, for example, alkaline ions, alkaline earth ions, ammonium ions and transition metal ions. Of these, sodium ions, potassium ions and ammonium ions are preferred. Examples of such basic aluminum carbonates include the salts described in Japanese Unexamined Patent Publication Hei 9-279131, and in the documents
Comprehensive inorganic chemistry vol. 2, page 1045 (1973), published by
Pergamon Press Ltd. and A comprehensive treatise on inorganic and theoretical chemistry vol. 5, pp. 358-359 (1960), published by Longman, Green and Co., Ltd.).

Although their manufacturing process is not particularly limited, these basic aluminum carbonates can be manufactured, for example, by the process disclosed in the published Japanese patent application.
Hei 9-279131, and it can be used alone or in combination.

 Usually, the molar ratio of aluminum ions to other cations in basic aluminum carbonate is 0.3 / 1 to 2/1, preferably 0.5 / 1 to 1.5 / 1 and more preferably 0 , 9/1 to 1.2 / 1. Usually, the molar ratio of aluminum ions to carbonate ions (Al / CO 3) is 0.3 / 1 to 2/1, preferably 0.8 / 1 to 1.5 / 1 and more preferably 1/1 at 1.3 / 1.

 The basic aluminum carbonate may be, for example, aluminum and sodium carbonate [Na 2 O, Al 2 O 3, 2CO 3, nH 2 O (n> O)], or aluminum and potassium carbonate [K 2 O, Al 2 O 3, 2CO 3, nH 2 O (n> 0)].

 The basic aluminum carbonate may contain water, preferably 10% by weight or less, more preferably 5% by weight or less and particularly preferably 3% by weight or less. Usually, this water content is determined by the protocol according to Japanese standard JIS K0067. More concretely, this water content is calculated as a mass loss rate after heating at 180 ° C for 2 hours.

Usually, the average particle diameter of the basic aluminum carbonate is at least 5 μm, preferably 0.05 to 3 μm, and particularly preferably 0.1 to 1 μm. When the resin composition of the The present invention is intended for a very demanding use with regard to transparency, the refractive index of the basic aluminum carbonate is preferably close to that of the polyolefin resin used. In general,
The index of refraction of the basic aluminum carbonate, determined by the protocol according to JIS K0062, is preferably from 1.47 to 1.55, more preferably from 1.48 to 1.54 and particularly preferably from 1, 49 to 1.53.

 The content of the basic aluminum carbonate in the resin composition of the present invention is preferably from 0.03 to 200 parts by weight per 100 parts by weight of polyolefin resin. When the resin composition is used as a cover film of an agricultural installation, the content of the basic aluminum carbonate is preferably 35 parts by mass or less, more preferably 20 parts by mass or less and particularly preferably preferably 15 parts by mass or less per 100 parts by weight of polyolefin resin, for reasons of transparency and mechanical strength of the film.

 The basic aluminum carbonate may be subjected to a surface treatment with dispersing agents to improve its dispersibility in the resin composition. Suitable dispersing agents include, for example, higher fatty acids such as stearic acid, palmitic acid and lauric acid, metal soaps such as calcium salts, zinc salts, magnesium salts, barium salts, and the like. and sodium salts of higher fatty acids, phosphates, silane coupling agents, aluminum coupling agents, zirconium coupling agents and waxes. The surface treatment may be carried out in any way that allows the dispersing agent to be uniformly attached to the surface of the basic aluminum carbonate. It is possible, for example, to use a process which comprises adding a basic aluminum carbonate to a suitable solvent to produce a suspension, mixing the suspension and a dispersing agent, and stirring the mixture. resulting.

 The hindered amine compounds for use in the present invention may be, for example, compounds whose structural formulas are set forth in Japanese Unexamined Patent Publication No. Hei 8-73667. include TINUVIN 622-LD, CHIMASSORB 944-LD, TINUVIN 123, produced by Ciba Specialty Chemicals KK, Hostavin N30, VP Sanduvor PR-31, produced by Clariant KK, and Cyasorb UV3526 produced by Cytec Industries Inc.

Examples of stabilizers containing sterically hindered amine compounds include TINUVIN 492 and TINUVIN 494, produced by
Ciba Specialty Chemicals KK and described in Japanese Patent Application Laid-Open No. Sho 63-286448. Hindered amine compounds can be used alone or in combinations of two or more of them.

 The content of the hindered amine compound in the resin composition of the present invention is 0.02 parts by weight or more per 100 parts by weight of polyolefin resin. To suppress the bleed, it is preferably less than or equal to 5 parts by weight, and more preferably from 0.1 to 2 parts by weight per 100 parts by weight of polyolefin resin.

 Examples of polyolefin resins which can be used in the resin composition of the present invention include homopolymers of α-olefins such as polyethylene and polypropylene, ethylene / α-olefin copolymers such as ethylene / propylene copolymers, copolymers ethylene / butylene, ethylene / 4-methylpentene-1-ene copolymers, ethylene / hexene copolymers and ethylene / octene copolymers, copolymers comprising ethylene and other monomers having a polar vinyl group such as ethylene / vinyl acetate copolymers, ethylene / acrylic acid copolymers, ethylene / methyl methacrylate copolymers, ethylene / vinyl acetate / methyl methacrylate terpolymers and monomeric resins.

When the resin composition of the present invention is used for agricultural films, polyethylene, an ethylene / α-olefin copolymer or an ethylene / vinyl acetate copolymer containing 30% by mass or less of polyethylene units are preferably used. vinyl acetate, for reasons of transparency, weather resistance and cost.

 Ethylene / α-olefin copolymers which are obtained by copolymerization of ethylene and a α-olefin having 3 to 18 carbon atoms by a catalyst called a "single site catalyst" are preferably used. that a complex catalyst of a transition metal, for example palladium or nickel, or a metallocene-type catalyst, in the presence or absence of a solvent in a gaseous / solid phase system, liquid / solid or in a homogeneous liquid phase. Typically, the polymerization temperature is from about 30 ° C to about 3000 ° C and the polymerization pressure is between about atmospheric pressure and about 2942 × 10 5 Pa (3000 kg / cm 2), for example, ethylene copolymers can be used. α-olefin that can be prepared by copolymerizing ethylene and an α-olefin having 3 to 18 carbon atoms in the presence of a metallocene catalyst to polymerize the olefins containing a metallocene catalyst component which is described in Japanese Patent Application Laid-Open No. Hei 6-9724, Hei 6-136195, Hei 6-136196 and Hei 6-207057.

To improve the weather resistance of the resin composition, it may contain at least one type of UV absorber This absorber
UV can be benzophenone, benzotriazole, benzoate or cyanoacrylate. It may be present in the range of 0.01 to 3 parts by weight, preferably 0.05 to 1 part by weight per 100 parts by weight of polyolefin resin to improve weather resistance and suppress bleeding.

The resin composition according to the present invention may contain at least one type of inorganic compound such as aluminum and lithium double hydroxides and hydrotalcite-type compounds, metal oxides such as magnesium oxide, calcium, aluminum oxide, silicon oxide and titanium oxide, hydroxides such as
Lithium hydroxide, magnesium hydroxide, calcium hydroxide and aluminum hydroxide, carbonates such as magnesium carbonate, calcium carbonate and basic aluminum carbonates, for example carbonates basic aluminum compounds described in Japanese Unexamined Patent Application N Hei 9-279131, sulphates such as potassium sulphate, magnesium sulphate, calcium sulphate, zinc sulphate and aluminum sulphate, phosphates such as lithium phosphate, sodium phosphate, potassium phosphate, calcium phosphate and zirconium phosphate, for example zirconium phosphate type H described in the Japanese patent application published before examination N Hei 6- 67774, silicates such as magnesium silicate, calcium silicate, aluminum silicate and titanium silicate, aluminates such as sodium aluminate, potassium aluminate and calcium aluminate, aluminosilica such as sodium aluminosilicate, potassium aluminosilicate and calcium aluminosilicate, clay minerals such as kaolin, clay and talc, and complex oxides.

The hydrotalcite-type compounds are compounds represented by the following formula (I)
M2 + 1-XAl3 + x (OH-) 2 (Al11-) x / n # mH2O (I) where M- is a divalent metal ion A1n- is n-valent anion and x, m and n are defined numbers respectively by the formulas: 0 <x <0.5, 0 <m <2 and 1 # n # 3. M2 may be for example Mg2 +, Ca2 +, Zn2 + The n-valent anion is not particularly limited and may be for example Cl-, Br-, I-, NO3-, ClO4-, SO42-, CO32-,
SiO32-, HPO43-, HBO43-, PO43-, Fe (CN) 63-, Fe (CN) 64-, CH3COO-, C6H4 (OH) COO-, (COO) 2 -, a terephthalate ion, a naphthalenesulphonate ion , a polysilicate ion or a polyphosphate ion which are described in Japanese Patent Application Laid-Open No. Hei 8-217912. For example, it is possible to use natural hydrotalcite and synthetic hydrotalcite designated by the trade name DHT-4A produced by Kyowa Chemical Industry, Co., Ltd.

The lithium aluminum hydroxide may be, for example, a compound represented by the following formula (II) described in Japanese Patent Application Laid-Open No. 5-179052
Li + (Al3 +) 2 (OH-) 6 # (A2n-) l / n # mH2O (II) where A, "- is an n-valent anion and m and n are numbers defined by the formulas 0 <m <3 and 11nu 3. The n-valent anion is not particularly limited and may be an anion similar to A1- compounds of formula (I).

Complex hydroxides other than those of the two types mentioned above may be, for example, hydroxyl-containing complex hydroxides which contain Li, Al and at least one element selected from the group consisting of alkaline earth metals, transition metals , Zn and
Si Among the alkaline earth metals, magnesium and calcium are preferred and among the transition metals di- or trivalent iron, cobalt, nickel and manganese, and iron in particular, are preferred. Usually, the molar ratio of Al to
Li is 1.5 / 1 to 2.5 / 1, and preferably 1.8 / 1 to 2.5 / 1.

 The molar ratio (a) of the element selected from the group consisting of alkaline earth metals, transition metals, Zn and Si to Li usually has the formula: 0 <a <1, preferably 0, 1 < a <1, 4, and more preferably 0.21a <1.2. In these complex hydroxides, the anionic part other than the hydroxyl group may for example consist of polysilicate ions such as pyrosilicate ions, cyclosilicate ions, isosilicate ions, phyllosilicate ions, tectosilicate ions, ions of inorganic acids such as carbonate ions, halide ions, sulphate ions, sulphite ions, nitrate ions, nitrite ions, phosphate ions, phosphite ions, hypophosphite ions, polyphosphate ions, aluminate ions, silicate ions, perchlorate ions and borate ions, anionic complexes of transition metals such as Fe (CN) 63 and Fe (CN) 64, organic acid ions such as acetate ions, benzoate ions, formate ions, terephthalate ions or ions sulfonate. Of these, carbonate ions, halide ions, sulfate ions, phosphate ions, polyphosphate ions, silicate ions, polysilicate ions and perchlorate ions are preferred.

A specific example of such complex hydroxides is a complex hydroxide containing Al, Li and Mg and having a molar ratio (Al / Li / Mg) of about 2.3 / 1 / 0.28 (trade name: LMA, produced by
Fuji Chemical Industry Co., Ltd.) and a complex hydroxide containing Al, Li and
Mg and having a molar ratio (Al / Li / Mg) of about 2/1 / 1.2 (trade name: FUJIRAIN LS, produced by Fuji Chemical Industry, Co., Ltd.).

Compounds represented by the following formula (III) which is given in WO97 / 00828:
[Li + (lx) M2 + x) (Al3 +) 2 (OH-) 6] 2SiyO (2y + 1) 2 -) (1 + x) # mH2O (III) where M2 + is a divalent metal and m, x and y are numbers defined by the following formulas: 0 <m <5, 0 <x <1 and 2 <y <4, and the compounds represented by the following formula given in Japanese Patent Application Laid-Open No. Hei 8-217912 :
[Li + (- x) M2 + x) (Al3 +) 2 (OH-) 6] 2 (An-) 2 (1 + x) / n # mH2O (IV) where M2 + is a divalent metal, A- is an anion n-valent and m, x and n are numbers defined by the following formulas: 0 # m # 5, 0.01 # x # 1 and 1 # n # 3 are preferable examples of complex oxides mentioned above. In the formulas (III) and (IV) M2 can be for example Mg2 +, Ca-, Zn2 +
The resin composition according to the present invention may contain at least one type of infrared (IR) absorber. These IR absorbers include, for example, organic IR absorbers such as polyacetals, (poly) vinyl alcohol and its derivatives and ethylene / vinyl alcohol copolymers.

The resin composition according to the present invention may contain at least one type of fogging agent which is a substance capable of preventing the formation of a fog in a greenhouse. These fogging agents may be, for example, fluorinated compounds having a perfluoroalkyl group, a hydrofluoroalkyl group or the like (in particular fluorinated surfactants) and silicone compounds having an alkylsiloxane group (in particular silicone-type surfactants), fluorinated surfactants having the trade names Unidyne DS-403, DS-406 and DS-401, produced by Daikin
Industries, Co., Ltd. are specific examples of such fluorinated surfactants. A specific example of a silicone surfactant is the product designated by the commercial name SH-3746 produced by Toray Dow
Corning Silicone Co., Ltd.

 The resin composition according to the present invention may contain at least one type of release agent. It is a substance that quickly removes condensed vapor on the film to prevent a film from forming on the film. The antiblocking agents may be liquid or solid at room temperature and may be nonionic surfactants of sorbitan ester and aliphatic acid type such as sorbitan monostearate, sorbitan monopalmitate, sorbitan monobhenate, and sorbitan, aliphatic acid ester and glycerol type such as glycerol monolaurate, glycerol monopalmitate, glycerol monostearate, diglycerol distearate, triglycerol monostearate and triglycerol monomontanate, polyethylene glycol type surfactants such as polyethylene glycol monopalmitate and polyethylene glycol monostearate, adducts of alkylphenols and alkylene oxides, esters of organic acids and sorbitan-glycerol condensation products, esters of fatty acids and polyoxyethylenealkylamine type, for example polyoxyethylene (2) stearylamine, polyoxyethylene ( 2) laurylamine and polyoxyethylene (4) stearylamine, for example polyoxyethylene (2) stearylamine monostearate, polyoxyethylene (2) stearylamine distearate polyoxyethylene (4) stearylamine monostearate, polyoxyethylene (4) stearylamine distearate, monostearate polyoxyethylene (8) stearylamine, polyoxyethylene (2) stearylamine monobhenate and polyoxyethylene (2) laurylamine monostearate, and amides of fatty acids and polyoxyethylene alkylamine compounds such as polyoxyethylene (2) stearamide.

 The liquid anti-blocking agent may be an aliphatic and glycerol acid ester such as glycerol monooleate, diglycerol monooleate, diglycerol sesquioleate, tetraglycerol monooleate, hexaglycerol monooleate, tetraglycerol trioleate, hexaglycerol pentaoleate, tetraglycerol monolaurate and hexaglycerol monolaurate, and an aliphatic and sorbitan acid ester such as sorbitan monooleate, sorbitan dioleate and sorbitan monolaurate.

 The resin composition according to the present invention may further contain various additives such as waxes, antioxidants, antistatic agents, light stabilizers other than hindered amine compounds, lubricants and algicides.

 The resin composition according to the present invention can be prepared for example by the following method. Predetermined amounts of basic aluminum carbonate and hindered amine compound, and optional additives, are added to the polyolefin resin and are mixed and kneaded using a mixing-kneading machine. Conventional apparatus such as a ribbon kneader, a super mixer, a Banbury mixer or a single or twin screw extruder can be used for this purpose. The resin composition thus obtained can be suitably processed by molding, for example extrusion molding, injection molding or extrusion-inflation. In particular, the resin composition according to the present invention can be employed in the production of films comprising at least one layer containing the resin composition.

 The resin composition may be subjected to post-dilution molding with a polyolefin resin or the like. In this case, the resin composition prior to dilution constitutes a masterbatch.

 The film according to the present invention may be a single layer film which comprises only a layer composed of the resin composition of the present invention, or a multilayer film which comprises two or more layers constituted by one or more resin compositions according to the invention. present invention. Alternatively, the film may be of another type of multilayer film which comprises at least one layer constituted by the resin composition of the present invention and at least one layer constituted by a resin composition different from the composition of the invention. resin according to the present invention. The layered structure of multilayer films of this type is not particularly limited and can be a two-layer structure of two types, three layers of two types, three layers of three types or five layers of three types, including. The resin composition according to the present invention is preferably one or more intermediate layers of the multilayer film which has three or more layers. When the film according to the present invention is a multilayer film which comprises a layer of a substance other than the resin composition according to the present invention, this layer is usually composed of a resin.

 The film according to the present invention can be produced by conventional methods such as an extrusion process, a coextrusion process, a melt coating process, an extrusion lamination process and a dry lamination method. .

 The resin to be used to form a layer which is not constituted by the resin composition according to the present invention may be a homopolymer of an α-olefin such as polyethylene and polypropylene, an ethylene / α-olefin copolymer such as an ethylene / propylene copolymer, an ethylene / but-1-ene copolymer, an ethylene / 4-methylpentene-ethylene copolymer, an ethylene / hexene copolymer or an ethylene / octene copolymer, a copolymer comprising ethylene and another or other monomers having a polar vinyl group such as an ethylene / vinyl acetate copolymer, an ethylene / acrylic acid copolymer, an ethylene / methyl methacrylate copolymer, an ethylene / vinyl acetate / methyl methacrylate terpolymer, and monomeric resins. When the resin composition according to the present invention is used for agricultural films, polyethylene, an ethylene / α-olefin copolymer or an ethylene / vinyl acetate copolymer containing 30% by mass or less of polyethylene units are preferably used. vinyl acetate, for reasons of transparency, weather resistance and cost, among others. For agricultural use, a multilayer film having an intermediate layer constituted by the resin composition according to the present invention is preferred.

 The film according to the present invention may contain at least one type of inorganic compound similar to those mentioned above, such as a complex hydroxide, a metal oxide, a hydroxide, a carbonate, a sulfate, a phosphate, a silicate, a aluminate, an aluminosilicate, a clay-like mineral or a complex oxide. The addition of such an inorganic compound improves the heat retention properties of the film.

 Although this inorganic compound may be contained in any layer of the film of the present invention, it is preferably contained in the layer constituted by the resin composition according to the present invention.

The content of the inorganic compound in the resin composition is preferably from 0.03 to 150 parts by weight, more preferably from 0.03 to 30 parts by weight, and particularly preferably from 0.03 to 15 parts by weight. per 100 parts by mass of polyolefin resin.

 The film according to the present invention may contain at least one IR absorber similar to those mentioned above.

 The film according to the present invention may contain at least one fogging agent similar to those mentioned above, preferably in a proportion of from 0.01 to 3% by weight, more preferably from 0, particularly preferably from 2.2 to 2.8. % by weight relative to the total mass of the film.

The film according to the present invention may comprise an anti-adherence coating on at least one of its surfaces to maintain its anti-adhesion properties for a long time. The release coating may be, for example, a coating film consisting of an inorganic oxide sol such as colloidal silica and colloidal alumina such as that described in Japanese Patent Application Publication Nos. 32668 and
Sho 50-11348, a coating film consisting of a mixture of an inorganic oxide sol and an organic compound (for example a surfactant or a resin) disclosed in Japanese Patent Application Laid-Open No. 63 -45432, Sho 63-45717 and Sho 64-2158 and in Japanese Unexamined Patent Application Publication No. Hei 3-207643, a coating film formed from a liquid comprising a surfactant as the main ingredient, a film of the invention. a hydrophilic resin (for example (poly) vinyl alcohol, polysaccharides, (poly) acrylic acid) as the main ingredient. The release coating may be formed by coating or laminating the pre-formed release coating on a multilayer film. The release coating may comprise a layer or two or more layers.

 The film according to the present invention can be produced by a conventional molding process such as a calendering process, an extrusion film molding process through a T die and an inflation film molding method. The thickness of the film is preferably 0.01 mm or more for reasons of mechanical strength of the film. Also preferably it is less than or equal to 0.3 mm to facilitate the operations of joining and application of the film. Particularly preferably, the thickness of the film is 0.03 to 0.25 mm.

 This film may suitably be used as an agricultural film, in particular as a cover film for an agricultural installation such as a greenhouse or a tunnel.

 The resin composition according to the present invention has excellent heat resistance, excellent weather resistance and excellent transparency. And it is used for the production of various industrial materials such as agricultural materials, household electrical appliances, motor vehicle materials and building materials.

In particular, a film containing the resin composition according to the present invention has excellent weatherability when used for agricultural purposes, for example as a cover film of a greenhouse or a tunnel and as a malting film . Thus, it is a useful material for protected horticulture.

The film according to the present invention is superior to conventional agricultural overcoating films with respect to weatherability under light exposure conditions and agrochemicals. In addition, the resin composition of the present invention deteriorates little and changes little color even in continuous molding. As a result, it foams little when molded and has excellent stability in long-lasting molding.

 The present invention will now be described in detail by means of the following non-limiting examples.

The test methods used in the examples were as follows
Thermal stability test
A test tube with a thickness of 1 mm was maintained at 1800C in air in a Geer furnace. The degree of coloring of the specimen was observed visually every hour and judged according to the following criteria:
O: slightly colored compared to the initial state
A: slight yellow or brown coloration compared to the initial state
X: yellow or brown coloring; and
XX: dark brown coloration compared to the initial state.

Weather resistance test (1)
A 1 mm thick test piece was maintained under a stream of air at a temperature of 60 ° C at a relative humidity of 32% for 24 hours using an EYESUPER UV TESTER SUV test apparatus. Wl 1 produced by Eye Graphics Co., Ltd. The color of the test specimen was observed visually and judged according to the following criteria:
O: slightly colored compared to the initial state;
A: slight yellow or brown coloration compared to the initial state;
X: yellow or brown coloring; and
XX: dark brown coloration compared to the initial state.

Weather resistance test (2)
A test tube of 1 mm thickness was suspended in a 500 ml glass bottle containing 50 ml of an aqueous solution of 6% sulfuric acid. With the bottle closed, it was kept at 400 ° C. for 4 hours. Thereafter, the specimen was held under a stream of air at a temperature of 60 ° C at 32% relative humidity for 24 hours using the EYESUPER UV TESTER SUV-W1 apparatus produced by Eye Graphics. Co.,
Ltd. The degree of coloring of the test specimen was observed visually and judged according to the following criteria:
O: slightly colored compared to the initial state A: slight yellow or brown coloration compared to the initial state;
X: yellow or brown coloring; and
XX: dark brown coloration compared to the initial state.

Measurement of transparency
The total light transmittance and haze were measured according to JIS K7105 by means of a sail measuring device produced by
Suga Test Instrument, Co., Ltd. The weaker the veil, the better the transparency.

EXAMPLES 1-3
In each example, a resin, a basic aluminum carbonate (component ratios: Al / Na = 1/1, A1 / CO3 = 1.2 / 1), a hindered amine compound and other additives were combined as shown in Table 1 below and kneaded using a Banbury mixer at 140 ° C for 5 min and then pelletized with an extruder to obtain pellets. molded under pressure to form a 1 mm thick sheet which was subjected to weathering tests (1) and (2) As shown in Table 1, the resin compositions exhibited excellent thermal stability and excellent weather resistance Details of the basic aluminum carbonate are given in Table 3.

COMPARATIVE EXAMPLES 1-3
Tests were carried out as described in Examples 1-3 except that hydrotalcite (trade name: DHT-4A, produced by Kyowa Chemical Industry, Co., Ltd.) was used in place of basic aluminum carbonate. The thermal stability and weatherability of the resin compositions obtained were inferior to those of the resin compositions of Examples 1-3.

EXAMPLES 4-6
In each example, a resin, a basic aluminum carbonate, a hindered amine compound and other additives were combined as shown in Table 2 below and kneaded using a Banbury mixer. at 140 ° C for 5 min, then pelletized using an extruder to obtain pellets The pellets were molded under pressure to form a 1 mm thick sheet which was subjected to the thermal stability test As shown in Table 2, the resin compositions had excellent athermic stability.

COMPARATIVE EXAMPLES 7-9
An assay was carried out as described in Examples 4-6 except that hydrotalcite (trade name: DHT-4A, produced by Kyowa Chemical Industry, Co., Ltd.) was used in place of basic aluminum carbonate. The thermal stability of the obtained resin compositions was lower than that of the resin compositions of Examples 4-6.

REFERENCE EXAMPLE 1
To 83.9 parts by weight of ethylene / vinyl acetate copolymer (trade name: Evatate H2031, produced by Sumitomo Chemical
Co,. Ltd.), 13 parts by weight of a basic aluminum carbonate, 0.3 parts by weight of the hindered amine compound A (trade name: TINUVYN 622, produced by Ciba Specialty were added).
Chemicals KK), 0.3 parts by weight of the hindered amine compound B (trade name: CHIMASSORB 944-LD, Ciba Specialty
Chemicals KK), 0.1 part by weight of a UV absorber (trade name: Sumisorb 130, Sumitomo Chemical Co., Ltd.), 0.1 part by weight of an antioxidant (trade name: Irganox 1010, Ciba Specialty
Chemicals KK), 1.4 parts by weight of monoglycerol monostearate, 0.6 parts by weight of diglycerol distearate, 0.2 parts by weight of stearic acid amide (lubricant) and 0.1 parts by weight of a fluorinated surfactant (fogging agent, trade name: DS-403, produced by Daikin Industries, Co., Ltd.) and then kneaded using a Banbury mixer at 1500C for 5 minutes, pelletized by means of an extruder to obtain pellets which are called resin composition (1). 96.9 parts by weight of ethylene / vinyl acetate copolymer (trade name: Evatate D2011, produced by Sumitomo
Chemical Co ,. Ltd.), 0.6 part by weight of the hindered amine compound A, 0.1 part by weight of the UV absorber, 0.1 part by weight of the antioxidant, 1.4 part by weight of monoglycerol monostearate mass, 0.6 part by weight of diglycerol distearate, 0.2 part by weight of stearic acid amide and 0.1 part by mass of fluorinated surfactant and then kneaded using a Banbury mixer to 1500C for 5 min and pelleted by means of an extruder to obtain pellets which are called resin composition (2). Using the two types of pellets above, it is possible to produce by means of an inflation film molding machine a multilayer film 0.1 mm thick having an intermediate layer constituted by the resin composition ( 1), an inner layer consisting of the resin composition (2) which is laminated on one side of the intermediate layer and an outer layer consisting of the resin composition (2) which is laminated on the other side of the intermediate layer. (The intermediate layer is 0.06 mm thick, and the inner layer and the outer layer are 0.02 mm thick each). During the molding process of the multilayer film there is no foaming of the resin compositions. The multilayer film obtained is excellent with respect to weather resistance, anti-blocking properties and transparency, so that it can suitably be used as an agricultural film.

REFERENCE EXAMPLE 2
To 86 parts by weight of ethylene / vinyl acetate copolymer (trade name: Evatate H2031, produced by Sumitomo Chemical
Co,. Ltd.) were added 13 parts by weight of basic aluminum carbonate, 0.6 parts by weight of hindered amine compound B, 0.1 parts by weight of UV absorber, 0.1 parts by weight of antioxidant and 0.2 parts by weight of stearic acid amide and then kneaded by means of a mixer
Banbury at 140 ° C for 5 min, pelletized with an extruder to obtain pellets which are referred to as resin composition (3) A 96.3 parts by weight of ethylene / vinyl acetate copolymer (trade name
Evatate D2011, produced by Sumitomo Chemical Co ,. Ltd.), 3.0 parts by weight of basic aluminum carbonate, 0.3 parts by weight of hindered amine compound A, 0.3 parts by weight of hindered amine compound B are added. and 0.1 parts by weight of antioxidant, then kneaded using a Banbury mixer at 140 ° C for 5 min and pelletized by means of an extruder to obtain pellets which are referred to as resin composition (4). 96 parts by weight of low density polyethylene (trade name: Sumikathene, F208-0, Sumitomo Chemical
Co,. Ltd.), 3.0 parts by weight of basic aluminum carbonate, 0.3 parts by weight of hindered amine compound A, 0.3 parts by weight of hindered amine compound B are added. , 0.1 part by weight of UV absorber, 0.1 part by weight of antioxidant and 0.2 part by weight of stearic acid amide, then kneaded by means of a mixer
Banbury at 140 ° C for 5 min and pelleted by extruder to obtain pellets which are called resin composition (5) Using the three types of pellets above it is possible to produce by an inflatable film molding machine a 0.1 mm thick multilayer film having an intermediate layer consisting of the resin composition (3), an inner layer consisting of the resin composition (4) which is laminated on one side of the intermediate layer and an outer layer consisting of the resin composition (5) which is laminated on the other side of the intermediate layer (the intermediate layer is 0.06 mm thick, the inner layer is 0.02 thick) mm and the outer layer is 0.02 mm thick) It is also possible to produce a film having an anti-adherence coating by applying the release agent coating liquid A comprising Snowtex 30, Kayacryl resin. H300, from the E pichlone 860, water and ethanol in a mixing ratio of 4: 3: 0.1: 75: 25 on the surface of the layer of the resin composition (4) by means of an applicator bar so as to obtain a solids content of about 1 g / m 9, and then by drying. These multilayer films are excellent in weatherability, anti-blocking properties, transparency, and can be suitably used as agricultural films. Snowtex 30 is the trade name for a colloidal silica produced by Nissan
Kagaku Kogyo KK Kayacryl H300 resin is the trade name for an acrylic emulsion produced by Nihon Kayaku Industries. Epichlone 860 is the trade name for a bisphenol A epoxy compound produced by Dainippon Ink.

REFERENCE EXAMPLE 3
It is possible to produce a multilayer film as described in Reference Example 2 except that 85% of each resin contained in the resin compositions (4) and (5) is replaced by an ethylene / commercial hexene obtained by polymerization using a metallocene catalyst. The multilayer film obtained is excellent with respect to contact release properties, weather resistance, transparency, and can be suitably used as an agricultural film.

In addition, it is possible to obtain a multilayer film having excellent anti-blocking properties and excellent fogging properties by subjecting a surface of the multilayer film obtained above to a corona discharge treatment, by applying to the surface the an antiblocking agent coating liquid B which is prepared in the following manner and drying at room temperature. The antiblock agent coating liquid B is prepared by diluting a mixture of alumina sol (trade name
Aluminasol 520, produced by Nissan Kagaku Kogyo KK, 20% solids content), of colloidal silica (Trade name: Snowtex 20, produced by
Nissan Kagaku Kogyo KK), sodium dodecylbenzenesulfonate (trade name: Neopelex, produced by Kao Corp.) and sodium decanate (produced by Nakalai tesque Ltd.) having a mixing ratio of 1.6 / 0.4 / 0 , 08 / 0.08 with water.

Tableaul

Composition <SEP> of <SEP> resin <SEP> Stability <SEP> thermal <SEP> Resistance <SEP> to <SEP> bad weather
<tb> Resin <SEP> HALS <SEP> AUV <SEP> Agent <SEP> AO <SEP> TGMS <SEP> Compound
<tb> (parts <SEP> into <SEP> (parts <SEP> into <SEP> (parts <SEP> (parts <SEP> (parts <SEP> inorganic <SEP> 1 <SEP> h <SEP> 2 <MS> h <SEP> 3 <SEP> h <SEP> 5 <SEP> h <SEP> (1) <SEP> (2)
<tb> mass) <SEP> mass) <SEP> in <SEP> mass) <SEP> in <SEP> mass) <SEP> in <SEP> mass) <SEP> (parts <SEP> in <SEP> mass )
<tb> Example <SEP> 1 <SEP> Al <SEP> (100) <SEP> 0.1 <SEP> SW <SEP> (10) <SEP> O <SEP> O <SEP> O <SEP> O - # <SEP> O <SEP> O
<tb> Example <SEP> 2 <SEP> Al <SEP> (100) <SEP> 0.1 <SEP> 0.1 <SEP> SW <SEP> (10) <SEP> O <SEP> O <SEP > O <SEP> O- # <SEP> O <SEP> O
<tb> Example <SEP> 3 <SEP> Al <SEP> (100) <SEP> 0.1 <SEP> 0.1 <SEP> 2.5 <SEP> SW <SEP> (10) <SEP> O <SEP> O <SEP> O <SEP> O- # <SEP> O <SEP> O
<tb> Example <SEP> Al <SEP> (100) <SEP> 0.1 <SEP> DHT-4A (10) <SEP> O- # <SEP>#<SEP># -X <SEP> XX <SEP> O <SEP>#
<tb> comparative <SEP> 1
<tb> Example <SEP> Al (100) <SEP> 0.1 <SEP> 0.1 <SEP> DHT-4A (10) <SEP>#<SEP>#<SEP># -X <SEP> XX <SEP> O <SEP>#
<tb> comparative <SEP> 2
<tb> Example <SEP> Al <SEP> (100) <SEP> 0.1 <SEP> 0.1 <SEP> 2.5 <SEP> DHT-4A (10) <SEP>#<SEP>#<SEP># -X <SEP># -X <SEP> O <SEP>#
<tb> comparative <SEP> 3
<tb> Notes
Al. Ethylene / vinyl acetate copolymer (trade name - Evatate H2031, produced by Sumitomo Chemical Co.,
Ltd. ; content of vinyl acetate units 19% by weight, melt index 1.5 g / 10 min).

HALS. Hindered amine compound B (trade name CHIMASSORB 944-LD, produced by Ciba
Specialty Chemicals KK)
UV absorber (AUV): trade name Sumisorb 130; produced by Sumitomo Chemical Co., Ltd.

Antioxidant (AO): trade name Irganox 1010, produced by ciba Specialty Chemicals K.K.

TGMS: tetrglycerol monostearate (trade name MS-310, produced by Sakamoto Yakuhin).

SW basic aluminum carbonate (component ratios # Al / Na = 1/1, Al / CO3 = 1.2 / 1, produced by Mizusawa Industrial
Chemicals, Ltd.). hydrotalcite. tradename. DHT-4A, produced by Kyowa Chemical Industry, Co., Ltd.

Table 2

Composition <SEP> of <SEP> resin <SEP> Stability <SEP> thermal
<tb> Resin <SEP> HALS <SEP> Compound <SEP> 1 <SEP> h <SEP> 2 <SEP> h <SEP> 3 <SEP> h <SEP> 5 <SEP> h
<tb> (parts <SEP> in <SEP> mass) <SEP> (parts <SEP> in <SEP> inorganic
<tb> mass) <SEP> (parts <SEP> in <SEP> mass)
<tb> Example <SEP> 4 <SEP> A2 <SEP> (100) <SEP> 0.1 <SEP> SW (2) <SEP> O <SEP> O- # <SEP> O- # <SEP> O #
<tb> Example <SEP> 5 <SEP> A2 <SEP> (100) <SEP> 0.1 <SEP> SW <SEP> (10) <SEP> O <SEP> O- # <SEP> O- # <SEP> O- #
<tb> Example <SEP> 6 <SEP> A2 (100) <SEP> 0.1 <SEP> SW <SEP> (20) <SEP> O <SEP> O- # <SEP> O- # <SEP> O #
<tb> Example <SEP> Comparative <SEP> 4 <SEP> A2 <SEP> (100) <SEP> 0.1 <SEP> DHT-4A <SEP> (2) <SEP> O <SEP> O- # <SEP>#<SEP># -X
<tb> Example <SEP> Comparative <SEP> 5 <SEP> A2 <SEP> (100) <SEP> 0.1 <SEP> DHT-4A <SEP> (10) <SEP> O <SEP> O- # <SEP>#<SEP> X
<tb> Example <SEP> Comparative <SEP> 6 <SEP> A2 <SEP> (100) <SEP> 0.1 <SEP> DHT-4A <SEP> (20) <SEP> O <SEP> O- # <SEP>#<SEP> X
<tb> Note:
A2: Low Density Polyethylene (Trade Name: Sumikathene F208-0, produced by Sumitomo Chemical Co., Ltd.

Melting index # 1.5 g / 10 min).

Table 3

DHT-4A <SEP> SW
<tb> (Hydrotalcite) <SEP>(<SEP> carbonate of aluminum <SEP> basic)
<tb> Composition <SEP> Chemical <SEP> MgO <SEP> 36.5 <SEP> Na2O. <SEP> 21.0
<tb> Al2O3 <SEP> 18.6 <SEP> Al2O3 <SEP>: <SEP> 36.2
<tb> CO2 <SEP> 8.3 <SEP> CO2. <SEP> 25.8
<tb> Humidity, <SEP> etc. <SEP> 36.6 <SEP> Humidity, <SEP> etc. <SEP> 17.0
<tb> Humidity <SEP> (%), <SEP> 110 C, <SEP> 2h <SEP> 0.7 <SEP> 0.9
<tb> loss <SEP> with <SEP> calcination <SEP> (%), <SEP> 180 C, <SEP> 2h <SEP> 4.2 <SEP> 2.7
<tb> index <SEP> of <SEP> refraction <SEP> 1.51 <SEP> 1.51
<tb> Diameter <SEP> average <SEP> of <SEP> particle <SEP>(<SEP> m) <SEP> 0,28 <SEP> 1,1
<tb> Note: The average particle diameter was determined by dispersing 1 g of a sample in 50 ml of ethanol and using a laser diffraction type particle size distribution analyzer.

Claims (14)

 A resin composition characterized in that it comprises a polyolefin resin, a basic aluminum carbonate and a hindered amine compound.  2. Resin composition according to claim 1, characterized in that the content of the basic aluminum carbonate is 0.03-200 parts by weight per 100 parts by weight of polyolefin resin.  The resin composition according to any one of claims 1 and 2, characterized in that the content of the hindered amine compound is from 0.02 to 5 parts by weight per 100 parts by weight of polyolefin resin.  4. Resin composition according to any one of the preceding claims, characterized in that the refractive index of the basic aluminum carbonate is between 1.48 and 1.53.  5. Resin composition according to any one of the preceding claims, characterized in that it further comprises a UV absorber.  6. Resin composition according to claim 5, characterized in that the content of the UV absorber is 0.01 to 3 parts by weight per 100 parts by weight of polyolefin resin.  7. Film characterized in that it comprises at least one layer comprising a resin composition according to any one of the claims I to 6.  8. Film according to claim 7, characterized in that it further comprises an anti-adhesion agent.  9. Film according to any one of claims 7 and 8, characterized in that it further comprises an anti-fog agent.  10. The film of claim 8, characterized in that the content of the anti-blocking agent is 0.1 to 4% by weight relative to the total mass of the film.  11. Film according to claim 9, characterized in that the content of the fogging agent is 0.01 to 3% by weight relative to the total mass of the film.  12. Film according to any one of claims 7 to 11, characterized in that it further comprises an anti-adhesion coating.  13. Use of a film according to any one of claims 7 to 12 as an agricultural film.  14. Use of a film according to any one of claims 7 to 12 in an agricultural installation.