JP2008280486A - Al-Li TYPE INFRARED RAY ABSORBER, ITS MANUFACTURING METHOD, FILM FOR AGRICULTURE AND MASTERBATCH PELLETS FOR AGRICULTURAL FILM - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an agricultural film, wherein when an infrared absorber having a high infrared absorbing capacity is blended with a resin, its dispersibilty is good, the film blended with the infrared absorber is superior in heat retaining property and its transparency is remarkably excellent compared with an existing article, and to provide a masterbatch pellet for the agricultural film. <P>SOLUTION: The Al-Li type infrared absorber contains as an effective component an Al-Li type layered double hydroxide particle powder shown by the formula: [Al<SB>2</SB>Li<SB>(1-x-y)</SB>M(II)<SB>x</SB>M(IV)<SB>y</SB>(OH)<SB>6</SB>]<SB>2</SB>(Si<SB>m</SB>O<SB>2m+1</SB>)z<SB>1</SB>(SO<SB>4</SB>)z<SB>2</SB>(CO<SB>3</SB>)z<SB>3</SB>(OH)z<SB>4</SB>nH<SB>2</SB>O (wherein, M (II) is a bivalent metal and M (IV) is a tetravalent metal), where [002] degree of orientation of the powder particles is not less than 1,000 cps. The agricultural film is blended with the Al-Li type infrared absorber. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention has a high infrared absorbing ability, good dispersibility when blended in a resin, a refractive index close to the refractive index of the resin, excellent transparency, and a film blended with the infrared absorbent. The present invention relates to an agricultural film having excellent heat retention and remarkably excellent transparency.

  Agricultural films used for greenhouse cultivation such as houses and tunnels efficiently transmit sunlight in the daytime with high transmittance, while at night, infrared rays radiated from the ground and plants are absorbed and reflected outside the house and tunnel. It is required to have characteristics such as preventing it from being released. It is known that the range in which the radiation rate of infrared rays emitted from the ground or plants is large is a wavelength range of 5 to 25 μm. As an agricultural film, it is necessary to be able to efficiently absorb infrared rays having a wavelength range of 5 to 25 μm, particularly, a wavelength in the vicinity of 10 μm at which the emissivity is maximum near room temperature (high heat retention).

  Conventionally, vinyl chloride resin has been frequently used for the agricultural film, but since there is a large environmental load such as generation of harmful gas during incineration after use, there is a strong tendency to change to olefin resin in recent years. .

  Since the olefin resin has a lower infrared absorbing ability than the vinyl chloride resin, heat retention is imparted by blending various infrared absorbers when molding into an agricultural film.

  Conventional infrared absorbers include magnesium carbonate, magnesium silicate, silicon dioxide, aluminum oxide, barium sulfate, calcium sulfate, magnesium hydroxide, aluminum hydroxide, calcium hydroxide, phosphate, silicate, hydrotalc Inorganic powders such as sites were used.

  However, each of the conventional inorganic powders has advantages and disadvantages, high infrared absorption ability, good dispersibility when blended with a resin, and sufficiently satisfies various physical properties such as a refractive index close to the refractive index of the resin. There is nothing. For example, silicon dioxide, aluminum silicate, etc. have excellent infrared absorption ability, but have problems in refractive index, dispersibility, etc., and the transparency of the film is impaired. Met. In addition, hydrotalcites are relatively satisfactory in dispersibility, refractive index and the like, but are not sufficiently satisfactory in infrared absorption ability.

In addition, Patent Document 1 includes the formula, [Al ₂ Li _(1-x) M ²⁺ _{(x + y)} (OH) _{(6 + 2y)} ] _n (A ⁿ⁻ ) _{(1 + x)} · mH ₂ O (wherein M ²⁺ divalent ^{metal, a n-n-valent} anion, m, x, y is in the range of 0 ≦ m <5,0.01 ≦ x ≦ 0.5,0 ≦ y ≦ 0.5) A technique for improving the heat retention and transparency of an agricultural film by blending the composite hydroxide salt shown in a resin is disclosed.

Patent Document 2 discloses that the anion between layers is at least one anion of silicon-based, phosphorus-based, and boron-based multimer oxyacid ions, and a part and / or all of them are silicon-based, phosphorus-based, and boron-based. The formula, [(Li _y1 G ²⁺ _y2 ) Al ₂ (OH) ₆ ] ^{x +} [(A) _z1 (B, which holds at least one anion of multimeric oxygenate ions and other anions. _Z2 · bH ₂ O] ^x- (wherein G ²⁺ is at least one divalent metal ion of Mg, Zn, Ca and Ni, and A is at least one of silicon-based, phosphorus-based and boron-based multimer oxygenate ions) B represents at least one anion other than A, and y1, y2, x, z1, z2 and b are 0 <y1 ≦ 1, 0 ≦ y2 <1, 0.5 ≦ (Y1 + y2) ≦ 1, x = y1 + 2y2, z1> 0, z2> 0, and 0 ≦ b <5)) Including the Li-Al hydrotalcite compound represented by A technique for increasing transparency is disclosed.

Patent Document 3 discloses that the formula, [Al ₂ Li _(1-x) M ²⁺ _{(x + y)} (OH) _{(6 + 2y)} ] ₂ (SO ₄ ) _z1 (CO ₃ ) _z2 (OH) _z3 · mH ₂ O ( ^Wherein M ²⁺ is a divalent metal, m, x, y, z1, z2, and z3 are 0 ≦ m <5, 0 ≦ x ≦ 0.5, 0 ≦ y ≦ 0.5, z1> 0. , Z2> 0, z3 ≧ 0, and within the range of z1 + z2 + z3 / 2 = 1 + x) are blended into the resin to obtain an agricultural film having excellent heat retention, transparency, and pesticide resistance. Technology is disclosed.

In addition, Patent Document 4 discloses that the formula, [Al ₂ Li _(1-x) M ²⁺ _{(x + y)} (OH) _{(6 + 2y)} ] _n (A ⁿ⁻ ) _{(1 + x)} · mH ₂ O (wherein M ²⁺ divalent ^{metal, a n-n-valent} anion, m, x, y are, 0 ≦ m <10,0.5 <x <1.0,0.5 < range of y ≦ 3.0 A technique for obtaining an agricultural film with improved heat retention, transparency, acid resistance, and moisture absorption whitening is disclosed by compounding a composite hydroxide salt represented by

Patent Document 5 discloses that the formula, [Al ₂ Li _(1-x) M ²⁺ _{(x + y)} (OH) _{(6 + 2y)} ] ₂ (Si _m O _{2m + 1} ) _z1 (SO ₄ ) _z2 (CO ₃ ) _z3 ( OH) _z4 · nH ₂ O (wherein M ²⁺ is a divalent metal, x, y, z1, z2, z3, z4, m, n are 0 ≦ x ≦ 0.5, 0 ≦ y ≦ 0. 5, z1> 0, z2> 0, z3> 0, z4> 0, z1 + z2 + z3 + z4 / 2 = 1 + x, 2 ≦ m ≦ 4, 0 ≦ n <5, 0 <SiO ₂ / Al ₂ O ₃ ≦ 0.5 A technique for obtaining an agricultural film excellent in heat retention, transparency, and pesticide resistance by blending a composite hydroxide salt represented by (within range) into a resin is disclosed.

Patent Document 6 discloses that the formula, [Al ₂ Li _(1-x) M ²⁺ _{(x + y)} (OH) _{(6 + 2y)} ] _n (A ⁿ⁻ ) _{(1 + x)} · mH ₂ O (wherein M ²⁺ Is a divalent metal, A ⁿ⁻ is an n-valent anion, 0 ≦ x <1.0, 0 ≦ y <3.0, m ≧ 0. Surface treatment with one or more selected from the group of higher fatty acids and higher aliphatic alcohol phosphates, 2) and further, higher fatty acids and higher aliphatic alcohol phosphate esters A technique for improving the colorability of a masterbatch or a film by incorporating a resin additive for improving coloration into the resin, which is characterized by blending one or more selected from the group, is disclosed.

International Publication No. 98/17739 Pamphlet JP 2001-2408 A JP 2002-146337 A JP 2003-165967 A Japanese Patent Laid-Open No. 2004-036992 JP 2004-043693 A

  High infrared absorption ability, excellent dispersibility when blended in resin, refractive index is close to the refractive index of resin, and highly transparent infrared absorber and film blended with the infrared absorber have heat retention Agricultural films that are excellent and even more transparent than existing products are currently in the most demanding situation. An infrared absorber that satisfies this requirement and an agricultural film that contains the infrared absorber are blended. The film has not yet been provided.

  The composite hydroxide salt or Li-Al hydrotalcite compound described in the above-mentioned Patent Documents 1 and 2 has a high infrared absorbing ability, good dispersibility when blended in a resin, and the refractive index is the refractive index of the resin. When the film was used for agriculture, it was excellent in heat retention and transparency.

  However, at the present time when the need for agricultural film transparency is further increased, the agricultural film containing the composite hydroxide salt or Li-Al hydrotalcite compound described in Patent Documents 1 to 2 is transparent. It was difficult to say that the present demand for remarkably superior performance was satisfactory.

  The composite hydroxide salt described in the above-mentioned Patent Document 3 is excellent in transparency and acid resistance when made into an agricultural film, but the film itself has a relatively heat retaining resin, for example, 15% containing vinyl acetate. When the above ethylene-vinyl acetate copolymer is kneaded in an amount of less than 10 parts by weight, or when kneaded in a relatively low heat retaining resin such as polyethylene, the composite hydroxide salt of the above-mentioned Patent Document 2 is used. It was hard to say that the heat retention was sufficient compared to the blended agricultural film.

  The composite hydroxide salt described in the above-mentioned Patent Document 4 replaces Li in the Al—Li-based composite layered double hydroxide particles with a large amount of a divalent metal, and forms a layered double hydroxide and a divalent metal hydroxide. Is a particle powder in which When the particle powder is blended in an agricultural film, it tends to be insufficiently dispersed in the resin due to the effect of the above-mentioned complexation, and it is difficult to say that film transparency and heat retention are sufficient.

  The composite hydroxide salt described in Patent Document 5 is excellent in transparency, heat retention, and acid resistance when used as an agricultural film, but is sufficiently satisfied with the current requirement that the transparency is remarkably excellent. It was hard to say that it was possible.

  Although the coloring improvement resin additive described in Patent Document 6 is improved in the colorability of the masterbatch and the film, it is difficult to say that it can be satisfactorily satisfied with the current requirement that the transparency is remarkably excellent. there were.

  Therefore, the present invention has a high infrared absorbing ability, has good dispersibility when blended in a resin, has a refractive index close to that of the resin, and has an excellent transparency and a blend of the infrared absorbent. It is a technical subject to obtain an agricultural film that has excellent heat retention and further excellent transparency compared to existing products.

  The technical problem can be achieved by the present invention as follows.

That is, the present invention has the formula: [Al ₂ Li _(1-xy) M (II) _x M (IV) _y (OH) ₆ ] ₂ (Si _m O _{2m + 1} ) _z1 (SO ₄ ) _z2 (CO ₃ ) _Z3 (OH) _{z4.nH 2} O (wherein M (II) is a divalent metal, M (IV) is a tetravalent metal, x, y, z1, z2, z3, z4, m, n are n 0 ≦ x ≦ 0.5, 0 ≦ y ≦ 0.5, z1> 0, 0 ≦ z2 ≦ 0.1, 0 <z3 ≦ 0.7, z4 ≧ 0, 0.5 <SiO ₂ / Al ₂ Al ₃ -Li-based layered double hydroxide particle powder represented by O ₃ ≦ 1.2), wherein the particle powder was measured by the following measurement method, and the [002] degree of orientation was 1000 cps or more. An Al-Li-based infrared absorber characterized by containing an Li-based composite layered double hydroxide particle powder as an active ingredient (Invention 1).
(1) Linear low-density polyethylene resin (trade name: Excellen FX CX2001, manufactured by Sumitomo Chemical Co., Ltd.): 84 parts by weight, Al-Li composite layered double hydroxide particle powder: 16 parts by weight are mixed, and 80 g of the mixture is mixed. A kneaded sheet is obtained by kneading in a hot roll. The kneading conditions are a kneading temperature of 140 ° C., a roll gap of 0.80 mm, and a kneading time of 3 minutes.
(2) The obtained kneaded sheet is subjected to pressure forming treatment with a hot press to obtain a press film having a film thickness of 100 μm. The pressurization conditions are a press temperature of 160 ° C., a press pressure of 150 kg weight / cm ² , a press time of 1 min, and a processing amount of 0.8 g.
(3) The X-ray diffraction pattern of the obtained press film is measured with the scattering vector perpendicular to the film film surface. Cu-Kα rays are used as X-rays, and the output is 40 kV-300 mA. The value obtained by removing the baseline intensity from the (002) diffraction peak intensity of the obtained diffraction pattern (unit: cps) represents the degree of [002] orientation of the Al—Li-based layered double hydroxide particles in the film. .

The present invention also provides an aqueous suspension in which lithium carbonate is mixed in an aqueous medium containing aluminum hydroxide to disperse a metal raw material, and sulfuric acid, TiOSO ₄ , ZrOCl _{2 is} added to the suspension. And one or more aqueous solutions selected from sodium silicate are added, followed by heat aging treatment to obtain carbonate ion-type Al-Li layered double hydroxide particles, and then the carbonate ion-type Al -The sulfuric acid is added to the suspension containing the Li-based layered double hydroxide particles to perform acid treatment, and the neutralization treatment is performed to adjust the pH of the suspension after acid treatment to 7.0 to 12.0. After performing, in the manufacturing process of adding an alkali silicate aqueous solution, then washing and drying to obtain an Al-Li composite layered double hydroxide particle powder, the acid treatment, neutralization treatment or alkali silicate aqueous solution To the suspension after any of the treatment One or more surface treatment agents selected from higher fatty acid salts, salts of higher fatty acid alcohol and phosphoric acid esters and higher fatty acid phosphoric acid esters are added, followed by wet treatment, This is a method for producing an Al—Li-based infrared absorber characterized by obtaining Al—Li-based composite layered double hydroxide particle powder by washing and drying (Invention 2).

  Further, the present invention provides the method for producing an Al-Li infrared absorber, wherein in the aqueous medium containing aluminum hydroxide, magnesium carbonate, water-soluble magnesium, magnesium hydroxide and water-soluble calcium are contained together with lithium carbonate. It is a manufacturing method of the Al-Li type infrared absorber which adds 1 or more types chosen from the inside (this invention 3).

  Moreover, this invention is an agricultural film characterized by blending 1 to 50 parts by weight of the Al—Li infrared absorber according to claim 1 with respect to 100 parts by weight of the resin (Invention 4).

  Moreover, this invention is a masterbatch pellet for agricultural films characterized by blending 10 to 250 parts by weight of the Al-Li infrared absorber according to claim 1 with respect to 100 parts by weight of resin (this book) Invention 5).

  The infrared absorber comprising the Al-Li composite layered double hydroxide particle powder according to the present invention is excellent in heat retention when molded into a resin film, and is further excellent in transparency compared to existing products. Therefore, it is suitable as an infrared absorber for agricultural films.

  The agricultural film according to the present invention is suitable as an agricultural film because it contains the infrared absorber according to the present invention, and thus has excellent heat retention and further excellent transparency compared to existing products. .

  The configuration of the present invention will be described in more detail as follows.

  First, the Al—Li-based composite layered double hydroxide particle powder in the present invention will be described.

The Al—Li-based composite layered double hydroxide particle powder in the present invention has the formula: [Al ₂ Li _(1-xy) M (II) _x M (IV) _y (OH) ₆ ] ₂ (Si _m O _{2m + 1) z1 (SO 4} ) z2 (CO 3) z3 (OH) z4 · nH 2 O ( wherein, M (II) is a divalent metal, M (IV) is a tetravalent metal, x, y, z1 , Z2, z3, z4, m, n are 0 ≦ x ≦ 0.5, 0 ≦ y ≦ 0.5, z1> 0, 0 ≦ z2 ≦ 0.1, 0 <z3 ≦ 0.7, z4 ≧ 0, 0.5 <within the range of SiO ₂ / Al ₂ O ₃ ≦ 1.2), and the particle powder was measured by the following measurement method [ 002] The degree of orientation is 1000 cps or more.
(1) Linear low-density polyethylene resin (trade name: Excellen FX CX2001, manufactured by Sumitomo Chemical Co., Ltd.): 84 parts by weight, Al-Li composite layered double hydroxide particle powder: 16 parts by weight are mixed, and 80 g of the mixture is mixed. A kneaded sheet is obtained by kneading in a hot roll. The kneading conditions are a kneading temperature of 140 ° C., a roll gap of 0.80 mm, and a kneading time of 3 minutes.
(2) The obtained kneaded sheet is subjected to pressure forming treatment with a hot press to obtain a press film having a film thickness of 100 μm. The pressurization conditions are a press temperature of 160 ° C., a press pressure of 150 kg weight / cm 2, a press time of 1 min, and a processing amount of 0.8 g.
(3) The X-ray diffraction pattern of the obtained press film is measured with the scattering vector perpendicular to the film film surface. Cu-Kα rays are used as X-rays, and the output is 40 kV-300 mA. The value obtained by removing the baseline intensity from the (002) diffraction peak intensity of the obtained diffraction pattern (unit: cps) represents the degree of [002] orientation of the Al—Li-based layered double hydroxide particles in the film. .

  When the degree of orientation is less than 1000 cps, the transparency of an agricultural film containing an infrared absorber containing the powder as an active ingredient is not preferable because it is not significantly superior to existing products. More preferably, it is 1200 cps or more, and the upper limit is about 8000 cps.

  Although it does not specifically limit as said bivalent metal, Mg, Ca, etc. are preferable from introduction | transduction being easy, being white and satisfy | filling transparency when mix | blended with a film.

  When the value of x in the above formula exceeds 0.5, the dispersion of the particle powder in the resin tends to be insufficient, and the film transparency and heat retention are deteriorated. Preferably 0 ≦ x ≦ 0.4.

  When the value of y in the above formula exceeds 0.5, the dispersion of the particle powder in the resin tends to be insufficient, and the film transparency and heat retention are lowered, which is not preferable. Preferably 0 ≦ y ≦ 0.35.

In the above formula, when the silicate ion or condensed silicate ion (Si _m O _{2m + 1} ) is not contained as an anion, the heat retaining property is lowered. When z1> 0 and m = 3, the upper limit is about 0.9. In the present invention, the value of m in (Si _m O _{2m + 1} ) in the above formula is preferably 2-4.

The content of silicate ions or condensed silicate ions is within the range of 0.5 <[SiO ₂ / Al ₂ O ₃ ] ≦ 1.2 in terms of [SiO ₂ / Al ₂ O ₃ (molar ratio)]. Become. In the case of 0.5 or less, the heat retaining property is lowered. When it exceeds 1.2, it becomes difficult to easily obtain a single phase of the layered double hydroxide. More preferably, it is in the range of 0.55 ≦ [SiO ₂ / Al ₂ O ₃ ] ≦ 1.2.

The content of sulfate ion (SO ₄ ²⁻ ) as an anion in the Al—Li-based composite layered double hydroxide particle powder in the present invention is 0 ≦ z2 ≦ 0.1, preferably 0 as z2 in the above formula. ≦ z2 ≦ 0.08.

The carbonate ion (CO ₃ ²⁻ ) content as an anion of the Al—Li-based composite layered double hydroxide particle powder in the present invention is 0 <z3 ≦ 0.7, preferably 0 as z3 in the above formula. .01 ≦ z3 ≦ 0.65.

The hydroxide ion (OH ⁻ ) content as an anion of the Al—Li-based composite layered double hydroxide particle powder in the present invention is z4 ≧ 0, preferably z4 ≧ 0.01, as z4 in the above formula. It is.

In the present invention, it is preferable that z1 + z2 + z3 + z4 / 2 = 1 + x + 3y is satisfied in the above formula. In the present invention, the value of n of nH ₂ O in the above formula is preferably 0 or more and less than 5.

  The particle shape of the Al—Li-based composite layered double hydroxide particle powder in the present invention is plate-like.

  The average secondary particle diameter of the Al—Li-based composite layered double hydroxide particle powder in the present invention is preferably 0.1 to 3.0 μm. When the average secondary particle diameter is less than 0.1 μm, the dispersibility in the resin is insufficient. When it exceeds 3.0 μm, the transparency of the agricultural film is lowered. More preferably, the average secondary particle size is 0.1 to 2.0 μm.

The BET specific surface area value of the Al—Li-based composite layered double hydroxide particle powder in the present invention is preferably 3 to 50 m ² / g. When the BET specific surface area value is less than 3 m ² / g, when dispersed in a resin, the influence of Rayleigh scattering becomes large, and the transparency of the agricultural film is unfavorable. When exceeding 50 m < ² > / g, since dispersion | distribution in resin becomes inadequate and the transparency of an agricultural film falls, it is unpreferable. A more preferable BET specific surface area value is 3 to 40 m ² / g.

  In the present invention, the Al-Li-based composite layered double hydroxide particle powder has a particle surface having higher fatty acids or higher fatty acid salts, esters of higher fatty acid alcohols and phosphoric acid or salts thereof, and higher fatty acid phosphates. Surface treatment is performed with one or two or more kinds of surface treatment agents selected from the types of salts.

  Among the surface treatment agents in the present invention, stearic acid, lauric acid, oleic acid and the like can be used as higher fatty acids. Of these, stearic acid and lauric acid are preferable.

  Among the surface treatment agents in the present invention, sodium stearate, sodium laurate benzenesulfonate, sodium oleate and the like can be used as higher fatty acid salts. Preferred are sodium stearate and sodium lauric acid benzenesulfonate.

  Among the surface treatment agents in the present invention, higher aliphatic alcohol and phosphoric acid esters include lauryl ether phosphoric acid, stearyl ether phosphoric acid, alkyl ether phosphoric acid such as oleyl ether phosphoric acid, dialkyl ether phosphoric acid, alkyl phenyl ether. Phosphoric acids and dialkylphenyl ether phosphoric acids can be used.

  Among the surface treatment agents in the present invention, salts of higher fatty acid alcohol and phosphoric acid esters include alkyl ether phosphoric acid such as lauryl ether phosphoric acid, stearyl ether phosphoric acid, oleyl ether phosphoric acid, dialkyl ether phosphoric acid, alkyl Sodium salts or potassium salts such as phenyl ether phosphoric acids and dialkyl phenyl ether phosphoric acids can be used.

  Among the surface treatment agents in the present invention, sodium salts or potassium salts of stearic acid phosphates can be used as the salts of higher fatty acid phosphates.

  Next, a method for producing the Al—Li composite layered double hydroxide particle powder according to the present invention will be described.

  The Al—Li-based composite layered double hydroxide particle powder according to the present invention 1 can be produced by the following method.

  First, lithium hydroxide is added to aluminum hydroxide in an aqueous medium to prepare an aqueous suspension in which a metal raw material is dispersed.

When producing an Al-Li composite layered double hydroxide particle powder containing Mg, when preparing an aqueous suspension in which the metal raw material is dispersed, together with lithium carbonate, magnesium carbonate or basic carbonate A water suspension in which a metal raw material is dispersed by adding one or more magnesium raw materials selected from magnesium carbonate such as magnesium or water-soluble magnesium such as magnesium chloride, magnesium sulfate, magnesium nitrate, and magnesium hydroxide. Prepare the solution.
In this case, the amount of the lithium carbonate and the magnesium raw material used is [Li / Al ₂ O ₃ (molar ratio)] + [MgO / Al ₂ O ₃ (molar ratio) with respect to the Al ₂ O ₃ content in the aluminum hydroxide. )] = 1. However, the lithium component may be added excessively.

  Moreover, when manufacturing Al-Li type composite layered double hydroxide particle powder containing Ca, water-soluble calcium such as calcium chloride and calcium nitrate is used as a calcium raw material in the same manner as described above. And react.

Carbonate ion type by heat treatment after adding a predetermined amount of one or more aqueous solutions selected from sulfuric acid, TiOSO ₄ , ZrOCl ₂ and sodium silicate to an aqueous suspension in which various metal raw materials are dispersed. Al-Li layered double hydroxide particles can be obtained.

The addition amount of sulfuric acid is preferably added so as to be within the range of 0.005 <[H ₂ SO ₄ / Al (molar ratio)] ≦ 0.050 with respect to the Al content in the aluminum hydroxide. In the case of 0.005 or less, the sulfuric acid addition effect does not sufficiently appear. When it exceeds 0.050, a carbonate ion type Al—Li-based layered double hydroxide single phase is not obtained, which is not preferable. More preferably, it is in the range of 0.006 ≦ [H ₂ SO ₄ / Al (molar ratio)] ≦ 0.040.

The addition amount of TiOSO ₄ is preferably added so as to be in the range of 0.001 <[Ti / Al (molar ratio)] ≦ 0.030 with respect to the Al content in the aluminum hydroxide. In the case of 0.001 or less, the effect of adding TiOSO ₄ does not sufficiently appear. When it exceeds 0.030, a carbonate ion type Al—Li-based layered double hydroxide single phase is not obtained, which is not preferable. More preferably, it is in the range of 0.002 ≦ [Ti / Al (molar ratio)] ≦ 0.025.

The addition amount of ZrOCl ₂ is preferably added so as to be in the range of 0.001 <[Zr / Al (molar ratio)] ≦ 0.030 with respect to the Al content in the aluminum hydroxide. When it is 0.001 or less, the effect of adding ZrOCl ₂ does not sufficiently appear. When it exceeds 0.030, a carbonate ion type Al—Li-based layered double hydroxide single phase is not obtained, which is not preferable. More preferably, it is in the range of 0.002 ≦ [Zr / Al (molar ratio)] ≦ 0.025.

The addition amount of sodium silicate is preferably added so that it is within the range of 0.001 <[SiO ₂ / Al (molar ratio)] ≦ 0.050 with respect to the Al content in the aluminum hydroxide. In the case of 0.001 or less, the effect of adding sodium silicate does not sufficiently appear. When it exceeds 0.050, a carbonate ion type Al—Li-based layered double hydroxide single phase is not obtained, which is not preferable. More preferably, it is in the range of 0.002 ≦ [SiO ₂ / Al (molar ratio)] ≦ 0.040.

  The temperature range of heat processing should just select the appropriate temperature between 50-200 degreeC, Preferably it is 90-160 degreeC, More preferably, it is 110-160 degreeC. When the treatment temperature is lower than 50 ° C., fine particles with reduced crystallinity are generated, which is not preferable.

  Water suspension containing carbonate ion type Al-Li composite layered double hydroxide particles (carbonate ion type Al-Li composite layered double hydroxide particles containing a divalent metal) obtained above After adding sulfuric acid to make the solution acidic (acid treatment), an alkali solution such as caustic soda is added to change the solution from neutral to alkaline (neutralization treatment). Further, an alkali silicate solution such as No. 3 water glass is added to this water suspension (alkali silicate treatment), and then washed, dried and pulverized.

  The concentration of sulfuric acid added during the acid treatment is not particularly limited, but carbonate ion-type Al-Li layered double hydroxide particles (carbonate ion type Al-Li composite layered double hydroxide particles containing a divalent metal) In consideration of not dissolving, the concentration is preferably 20% by weight or less. Moreover, it is preferable to add sulfuric acid until the pH of a suspension becomes 3.0-6.0, More preferably, it is pH 3.0-5.0.

  The alkaline solution added during the neutralization treatment is not particularly limited, but a caustic soda solution having a concentration of 25% by weight or less is preferable in consideration of industrial productivity. Further, the alkaline solution is preferably added until the pH of the suspension becomes 7.0 to 12.0, and more preferably pH 9.0 to 12.0.

The amount of the alkali silicate solution added at the time of the alkali silicate treatment is the carbonate ion-type Al—Li-based layered double hydroxide particles (the carbonate ion-type Al—Li-based composite layered double hydroxide containing a divalent metal). Particles) Add so that 0.5 <[SiO ₂ / Al ₂ O ₃ (molar ratio)] ≦ 1.2 with respect to the Al ₂ O ₃ content of the aluminum hydroxide used during the formation reaction. It is preferable. More preferably, it is in the range of 0.6 ≦ [SiO ₂ / Al ₂ O ₃ (molar ratio)] ≦ 1.2.

  The temperature of the suspension when adding the alkali silicate solution is preferably from room temperature to 100 ° C. When the temperature exceeds 100 ° C., a pressure vessel is required, which is not economical. More preferably, it is the normal temperature to 80 ° C temperature range.

  An aqueous suspension containing Al-Li-based layered double hydroxide particles (Al-Li-based composite layered double hydroxide particles containing a divalent metal) to which an alkali silicate solution has been added is washed with water, The Al-Li layered double hydroxide particles in the present invention can be obtained by drying and pulverizing, but by washing with appropriate concentrations of caustic soda, sodium carbonate, sodium bicarbonate, etc., the layers between the layered double hydroxide particles can be obtained. The content ratio of various anions can be controlled.

In addition, the Al—Li-based layered double hydroxide particle powder (Al—Li-based composite layered double hydroxide particles containing a divalent metal) is heated at 120 to 300 ° C. in the air or in the presence of N ₂ , He or the like. Heat treatment may be performed in an active gas atmosphere for 1 to 24 hours.

  The Al—Li based composite layered double hydroxide particle powder according to the present invention can be obtained by subjecting the Al—Li based layered double hydroxide particle powder to a surface treatment with the surface treating agent.

  The surface treatment in the present invention is carried out during the production of Al-Li-based layered double hydroxide particles (Al-Li-based composite layered double hydroxide particles containing a divalent metal) with higher fatty acid salts, higher fatty acid group alcohols and Wet treatment is carried out with one or more surface treatment agents selected from salts of phosphoric acid esters and higher fatty acid phosphoric acid esters.

  The wet treatment may be performed at any stage after the acid treatment, after the neutralization treatment or after the alkali silicate treatment in the production process of the Al—Li-based layered double hydroxide particle powder. Preferably, after the neutralization treatment or after the alkali silicate treatment.

  The addition amount of the surface treatment agent in the wet treatment is preferably 0.3 to 15.0% by weight in terms of C with respect to the Al—Li-based layered double hydroxide particle powder, more preferably 0.5 to 12.0. % By weight. When the addition amount is less than 0.2% by weight, the effect of the treatment agent cannot be obtained. If it exceeds 15.0% by weight, the effect is saturated, so there is no point in adding more than necessary.

  Next, the agricultural film according to the present invention 4 will be described.

  Examples of the resin used in the agricultural film according to the present invention 4 include polymers or copolymers of olefins such as ethylene, propylene, butene-1, and vinyl acetate, for example, polyethylene such as low density polyethylene and linear low density polyethylene. , Polypropylene, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, and the like. Among these, polyethylene, an ethylene-α-olefin copolymer, and an ethylene-vinyl acetate copolymer having a vinyl acetate content of 25% by weight or less are preferable in consideration of transparency, weather resistance, and price.

  In producing the agricultural film according to the present invention 4, when necessary, known lubricants, light stabilizers, antioxidants, antiblocking agents, antistatic agents, ultraviolet absorbers, antifogging agents, antifogging agents, and pigments. , Dyes, heat stabilizers, and the like can be added as appropriate.

  The agricultural film according to the present invention 4 may have a laminated structure as necessary.

  The content of the Al-Li composite layered double hydroxide particle powder in the agricultural film according to the present invention 4 is preferably 1 to 30 parts by weight, more preferably 2 to 25 parts by weight with respect to 100 parts by weight of the resin. It is. When the amount is less than 1 part by weight, the effect of improving the heat retention performance is insufficient. When it exceeds 30 parts by weight, the transparency of the agricultural film is lowered, which is not preferable.

  The heat retention of the agricultural film according to the present invention 4 is a heat retention index measured according to an evaluation method described later, and is preferably 70% or more, and more preferably 80% or more.

  The transparency of the agricultural film according to the present invention 4 is evaluated by the total light transmittance and the internal haze value measured according to the evaluation method described later. The total light transmittance is preferably 85.0% or more, more preferably 86.0% or more. The internal haze value is preferably 6.0% or less, more preferably 5.0% or less.

  Next, the manufacturing method of the agricultural film which concerns on this invention 4 is described.

  The agricultural film according to the present invention comprises the Al-Li-based composite layered double hydroxide particle powder and resin according to the present invention, for example, a ribbon blender, a nauter mixer, a Banbury mixer, a super mixer, a Henschel mixer, etc. And then mixed and then melt-kneaded using an extruder, Banbury mixer, pressure kneader, etc., and then formed into a film by a method such as an inflation method or a T-die method. it can.

  In the present invention, as will be described later, a master batch pellet prepared by mixing a predetermined amount of the above-described resin and Al-Li composite layered double hydroxide particle powder is prepared, and the agriculture is performed using the pellet. A film may be produced.

  Next, the master batch pellet for agricultural film according to the fifth aspect of the present invention will be described.

  Examples of the resin used for the master batch pellet for agricultural film according to the present invention 5 include polymers or copolymers of olefins such as ethylene, propylene, butene-1, and vinyl acetate, such as low-density polyethylene and linear low-density. Examples include polyethylene such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, and ethylene-α-olefin copolymer. Among these, polyethylene, an ethylene-α-olefin copolymer, and an ethylene-vinyl acetate copolymer having a vinyl acetate content of 25% by weight or less are preferable in consideration of transparency, weather resistance, and price.

  In addition, the resin used for a masterbatch pellet may use the same resin as the resin for dilution used at the time of manufacture of the agricultural film which concerns on this invention 3, and may use a different resin. When different resins are used, it is preferable to consider various characteristics determined by the compatibility between the resins.

  The content of the Al-Li composite layered double hydroxide particle powder in the master batch pellet for agricultural film according to the present invention 5 is preferably 10 to 250 parts by weight, more preferably 20 parts per 100 parts by weight of the resin. -220 parts by weight. When the amount is less than 10 parts by weight, the melt viscosity at the time of resin kneading is insufficient, and it is difficult to achieve good dispersion mixing of the heat retaining agent. When the amount exceeds 250 parts by weight, the resin is insufficient, which makes it difficult to disperse and mix the heat retaining agent, which is not preferable.

  The master batch pellet for agricultural film according to the fifth aspect of the present invention is prepared by mixing a resin and a heat-retaining agent with a mixer such as a ribbon blender, a nauter mixer, a Henschel mixer, a super mixer, etc. It is manufactured by kneading and molding with a shaft kneading extruder or the like and then cutting, or by kneading or molding and cutting the kneaded product obtained by kneading the above mixture with a Banbury mixer, pressure kneader or the like.

  In producing the master batch pellets for agricultural film according to the present invention 5, known lubricants, light stabilizers, antioxidants, antiblocking agents, antistatic agents, ultraviolet absorbers, antifoggants, A clouding agent, a pigment, a dye, a heat stabilizer, and the like can be appropriately added.

The master batch pellet for agricultural film according to the present invention 5 preferably has an average major axis of 1 to 6 mm, more preferably 2 to 5 mm. The average minor axis is preferably 2 to 5 mm, more preferably 2.5 to 4 mm. When the average major axis is less than 1 mm, the workability of pellet production is poor, which is not preferable. When the size exceeds 6 mm, the difference from the size of the dilution resin is large, and it becomes difficult to sufficiently disperse and mix.
Also, the pellet shape can be various, and can be processed into a granular shape such as an irregular shape or a spherical shape, a cylindrical shape, a flake shape, or the like.

<Action>
An important point in the present invention is that an agricultural film containing an infrared absorber containing the Al-Li composite layered double hydroxide particle powder according to the present invention as an active ingredient is excellent in heat retention and further transparent. Is significantly superior to existing products.

  The inventor presumes the reason why the agricultural film containing the Al—Li-based composite layered double hydroxide particle powder according to the present invention is excellent in transparency as follows.

When the Al—Li-based composite layered double hydroxide particle powder according to the present invention is molded into an agricultural film, the [002] direction of the 2H-type crystal structure tends to be oriented perpendicular to the film surface. This corresponds to the fact that the individual plate-like particle (primary particle) plate surfaces constituting the Al-Li-based composite layered double hydroxide particle powder have a high ratio of being arranged in parallel with the film film surface. When the plate-like particle plate surface is arranged in parallel with the film film surface, the vertically incident light on the film film surface recognizes the heat insulating agent particle size as a scatterer as the thickness of the plate-like crystal.
Therefore, the present inventor presumes that the higher the [002] orientation degree, the smaller the thickness of the plate-like crystal, the more effective the action, and the less the influence of Rayleigh scattering, so that the film transparency is improved. Yes.

  The inventor presumes the reason why the [002] orientation degree of the Al—Li-based composite layered double hydroxide particle powder according to the present invention is high as follows.

The Al—Li-based composite layered double hydroxide particle powder according to the present invention is obtained by preparing a water suspension in which a metal raw material is dispersed when producing a precursor of the carbonate ion type layered double hydroxide particle powder. A predetermined amount of one or more aqueous solutions selected from sulfuric acid, TiOSO ₄ , ZrOCl ₂ and sodium silicate are added to the suspension, followed by heat aging treatment. Due to this addition effect, the carbonate ion-type layered double hydroxide particle powder to be produced becomes a primary particle shape with a thin plate crystal thickness and a high plate ratio. This primary particle shape is inherited even after post-treatment of acid treatment, neutralization treatment, alkali silicate treatment, washing, drying, and pulverization.
The [002] orientation of the Al—Li composite layered double hydroxide particle powder according to the present invention due to the synergistic effect that the primary particle thickness is moderately thin and the plate ratio is high and the dispersibility in the resin is excellent. The present inventor presumes that the degree is improved.

  Representative examples of the present invention are as follows.

  Various characteristics of the Al-Li composite layered double hydroxide particle powder and the agricultural film according to the present invention were evaluated by the following methods.

  The average secondary particle diameter of the Al-Li composite layered double hydroxide particle powder was measured using a laser diffraction particle size distribution analyzer: SALD-2000J (manufactured by Shimadzu Corporation).

  The crystal phase of the Al-Li composite layered double hydroxide particle powder is identified by X-ray diffractometer: RINT 2500 (manufactured by Rigaku Corporation) (tube: Cu, tube voltage: 40 kV, tube current: 300 mA, goniometer : Wide angle goniometer, sampling width: 0.040 °, scanning speed: 2.000 ° / min, diverging slit: 1 °, scattering slit: 1 °, light receiving slit: 0.30 mm), and diffraction angle 2θ is Evaluation was performed by measuring 2θ / θ at 5 to 90 °.

  The BET specific surface area value was shown as a value measured by the BET method.

The Al—Li-based composite layered double hydroxide particle powder is expressed by the formula: [Al ₂ Li _(1-xy) M (II) _x M (IV) _y (OH) ₆ ] ₂ (Si _m O _{2m + 1} ) _z1 ( _{SO 4) z2 (CO 3)} z3 (OH) z4 · nH 2 O and in the case of representation x, y, m, z1 can be prepared by dissolving the powder in an acid, a plasma emission spectrometer: SPS4000 (Seiko ) And measured.
z2 and z3 were determined by measuring the carbon and sulfur content (% by weight) of the powder using a carbon sulfur analyzer: EMIA-2200 (manufactured by HORIBA).
z4 was calculated from the relational expression z1 + z2 + z3 + z4 / 2 = 1 + x + 3y.
[SiO ₂ / Al ₂ O ₃ (molar ratio)] was determined by dissolving the powder with an acid and measuring it with a plasma emission spectrometer: SPS4000 (Seiko Electronics Co., Ltd.).

  The degree of [002] orientation in the agricultural film of the Al—Li based composite layered double hydroxide particle powder was evaluated by the method described above.

  The heat retention of the agricultural film was measured by the following method.

  A predetermined part by weight of Al-Li composite layered double hydroxide particle powder is mixed with 100 parts by weight of the resin, and the mixture is kneaded in a hot roll to obtain a kneaded sheet. A press film having a thickness of 100 μm was produced by pressure treatment. The kneading temperature of the hot roll is 140 to 150 ° C., and the pressing temperature of the hot press is 160 ° C. The heat retention and transparency of the obtained agricultural film were measured and evaluated by the following methods.

The heat retention was evaluated by a heat retention index. The agricultural Fourier transform infrared spectrophotometer infrared absorption spectrum of the film: using FTIR-8700 ((Ltd.) manufactured by Shimadzu Corporation) (measured in the range of 2,000～400Cm ^-1 per ^{1 cm -1,} The corrected absorptivity of each wave number was obtained by correcting with a film thickness of 100 μm, and the relative black body radiant energy absorption rate was calculated by multiplying the corrected absorptivity by the relative black body radiant energy of 15 ° C. for each wave number. The relative black body radiant energy absorption rate of wave number is integrated, and the value is divided by the total relative black body radiant energy of 2,000 to 400 cm ⁻¹ to obtain the heat retention index. The higher the one.

  Film transparency is measured using a spectrophotometer: JASCO V-560 (manufactured by JASCO Corporation), with light at a wavelength of 535 nm vertically incident on the film surface, and measuring the total light transmittance and internal haze value. And evaluated. Internal haze was measured with the film immersed in 2-propanol. The closer to 100 the total light transmittance, the better the visible light transmittance, and the smaller the internal haze value, the less the haze.

Example 1
214.0 g of aluminum hydroxide powder containing 65 wt% as Al ₂ O ₃ , 13.9 g of magnesium carbonate containing 42.0 wt% as MgO, and 45.2 g of lithium carbonate to add water to a total volume of 3 l, Stir well. To this suspension, 20.2 g of a 20% by weight aqueous sulfuric acid solution is added and stirred thoroughly. This suspension was inserted into an autoclave having an internal volume of 5 l and aged by heating at 150 ° C. for 5 hours to form a white precipitate. A part of the obtained white precipitate was taken out, filtered, washed with water and dried and identified by X-ray diffraction. As a result, it was a layered double hydroxide particle (carbonate ion type Al-Li layered double hydroxide particle). It was confirmed.
Next, after the suspension containing the white precipitate was cooled to 60 ° C., sulfuric acid having a concentration of 8% by weight was added until the pH reached 4.0 (acid treatment). Subsequently, 25% caustic soda solution was added to adjust the pH to 11.0 (neutralization treatment), and 3762 g of 15% sodium silicate aqueous solution was added.
Next, 1.05 l of a 1% solution of stearic acid phosphate Na salt was added to the suspension to perform wet surface treatment. The suspension was filtered with Nutsche, washed with an aqueous solution of 0.5% caustic soda 15 times the amount of the product, and further washed with 40 times the amount of water of the product. After washing, drying at 110 ° C. for 20 hours, further drying at 200 ° C. for 1 hour, and sieving with a 100 mesh sieve, an Al—Li based composite layered double hydroxide particle powder was obtained.
The powder had an average particle size of 0.80 μm and a specific surface area of 12.1 m ² / g. The composition of the powder was [Al ₂ Li _0.90 Mg _0.10 (OH) ₆ ] ₂ (Si ₃ O ₇ ) _0.65 (SO ₄ ) _0.06 (CO ₃ ) _0.21 (OH) _{0 .36} · 1.05H ₂ O. The carbon content of the powder was 5.48 wt%. Further, the [002] orientation degree of the powder was 1650 cps.

Examples 2-8, Comparative Examples 1-3
Various types and contents of divalent metals, acid treatment conditions, neutralization treatment conditions, addition amount of alkali silicate, cleaning conditions, etc., and surface treatment agents in wet surface treatment and dry treatment with surface treatment agents An Al—Li-based composite layered double hydroxide particle powder was obtained in the same manner as in Example 1 except that the kind and amount of addition were varied.

In Examples 3 and 4, the magnesium raw material was not added to Example 1.
In Example 5, a magnesium raw material was not added to Example 1, but TiOSO ₄ was added instead of the addition of sulfuric acid during the production of carbonate ion-type Al—Li-based layered double hydroxide particles.
In Example 6, ZrOCl ₂ was added instead of TiOSO ₄ of Example 5.
In Example 7, water glass was added instead of TiOSO ₄ in Example 5.
In Example 8, a calcium chloride aqueous solution was added to Example 1 in place of the magnesium raw material, and the surface treatment was performed with sodium stearate.
In Comparative Example 1, sulfuric acid was not added when the carbonate ion-type Al—Li layered double hydroxide particles of Example 1 were produced.
In Comparative Example 2, no magnesium raw material was added to Comparative Example 1.
Comparative Example 3 is obtained by increasing the amount of sulfuric acid added to Example 3.

  Table 1 shows properties of the obtained Al-Li composite layered double hydroxide particle powder.

Example 9
16 parts by weight of the Al—Li-based composite layered double hydroxide particle powder obtained in Example 1 and 84 parts by weight of a linear low density polyethylene resin (trade name: Excellen FX CX2001, manufactured by Sumitomo Chemical Co., Ltd.) are mixed, and the mixture is mixed. Were kneaded in a hot roll to obtain a kneaded sheet, and then a press film with a thickness of 100 μm was produced by pressurizing with a hot press. The kneading temperature of the hot roll is 140 ° C., and the pressing temperature of the hot press is 160 ° C.

  The heat retention index of the obtained agricultural film was 86.6%, and the transparency was 87.9% in total light transmittance and 2.6% in internal haze value.

Examples 10-16, Comparative Examples 4-6
Each of the Al-Li composite layered double hydroxide particle powders of Examples 2 to 8 and Comparative Examples 1 to 3 and a polyolefin resin were blended in the composition shown in Table 2, and the agricultural film was prepared in the same manner as in Example 9. Produced.

  Table 2 shows various characteristics of the obtained agricultural film.

The infrared absorber containing the Al-Li composite layered double hydroxide particle powder according to the present invention as an active ingredient is excellent in heat retention when blended with a resin and molded into a film, and further has transparency as an existing product. Therefore, it is suitable as an infrared absorber for agricultural film applications.

Claims (5)

_{Wherein, [Al 2 Li (1-} x-y) M (II) x M (IV) y (OH) 6] 2 (Si m O 2m + 1) z1 (SO 4) z2 (CO 3) z3 (OH) z4 NH ₂ O (wherein M (II) is a divalent metal, M (IV) is a tetravalent metal, x, y, z1, z2, z3, z4, m, and n are 0 ≦ x ≦ 0 0.5, 0 ≦ y ≦ 0.5, z1> 0, 0 ≦ z2 ≦ 0.1, 0 <z3 ≦ 0.7, z4 ≧ 0, 0.5 <SiO ₂ / Al ₂ O ₃ ≦ 1.2 Al-Li-based layered double hydroxide particle powder represented by the following formula: [002] Al-Li-based layered double water having a degree of orientation of 1000 cps or more measured by the following measurement method An Al-Li infrared absorber comprising oxide particle powder as an active ingredient.
(1) Linear low-density polyethylene resin (trade name: Excellen FX CX2001, manufactured by Sumitomo Chemical Co., Ltd.): 84 parts by weight, Al-Li composite layered double hydroxide particle powder: 16 parts by weight are mixed, and 80 g of the mixture is mixed. A kneaded sheet is obtained by kneading in a hot roll. The kneading conditions are a kneading temperature of 140 ° C., a roll gap of 0.80 mm, and a kneading time of 3 minutes.
(2) The obtained kneaded sheet is subjected to pressure forming treatment with a hot press to obtain a press film having a film thickness of 100 μm. The pressurization conditions are a press temperature of 160 ° C., a press pressure of 150 kg weight / cm ² , a press time of 1 min, and a processing amount of 0.8 g.
(3) The X-ray diffraction pattern of the obtained press film is measured with the scattering vector perpendicular to the film film surface. Cu-Kα rays are used as X-rays, and the output is 40 kV-300 mA. The value obtained by removing the baseline intensity from the (002) diffraction peak intensity of the obtained diffraction pattern (unit: cps) represents the degree of [002] orientation of the Al—Li-based layered double hydroxide particles in the film. . Lithium carbonate is mixed in an aqueous medium containing aluminum hydroxide to prepare an aqueous suspension in which a metal raw material is dispersed, and the suspension is selected from sulfuric acid, TiOSO ₄ , ZrOCl ₂ and sodium silicate. 1 type or 2 types or more of aqueous solutions are added, followed by heat aging treatment to obtain carbonate ion-type Al—Li layered double hydroxide particles, and then the carbonate ion type Al—Li layered double water. After the sulfuric acid is added to the suspension containing the oxide particles, the acid treatment is performed, and after the neutralization treatment for adjusting the pH of the suspension after the acid treatment to 7.0 to 12.0, the silicic acid is added. In the production process of adding an alkaline aqueous solution, then washing and drying to obtain Al-Li composite layered double hydroxide particle powder, any of the acid treatment, neutralization treatment or treatment with an alkali silicate aqueous solution In later suspension, higher fatty acid salts One or more surface treatment agents selected from salts of higher fatty acid alcohol and phosphoric acid esters and higher fatty acid phosphoric acid esters are added to perform wet treatment, and then washed and dried. To obtain an Al—Li-based composite layered double hydroxide particle powder. In the method for producing the Al-Li infrared absorber, one kind selected from magnesium carbonate, water-soluble magnesium, magnesium hydroxide and water-soluble calcium together with lithium carbonate in an aqueous medium containing aluminum hydroxide. The manufacturing method of the Al-Li type infrared absorber which adds the above. An agricultural film comprising 1 to 50 parts by weight of the Al-Li infrared absorber according to claim 1 per 100 parts by weight of the resin. A master batch pellet for agricultural film, wherein 10 to 250 parts by weight of the Al-Li infrared absorber according to claim 1 is blended with 100 parts by weight of the resin.