WO2015190724A1 - Agricultural film composition having improved warmth-retaining and insulation properties, and agricultural film manufactured therefrom - Google Patents

Abstract

The present invention relates to an agricultural film having improved warmth-retaining and insulation properties, comprising: at least one polyethylene-based polymer resin selected from low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE); a surface-modified hydrophilic aerogel or a silylated aerogel having a porosity of 90 to 99.8%, a particle size of 10 to 100 nm, and a refractive index of 1.007 to 1.05, as a second ingredient; and at least one ingredient selected from a polymer (LLDPE-g-MAH) formed by grafting linear low-density polyethylene with maleic anhydride, polyethylene wax, and silicone-modified polyethylene wax.

Description

Agricultural film composition with improved thermal insulation and insulation and agricultural film produced therefrom

The present invention relates to an agricultural film, and more particularly, to an agricultural film composition for use in greenhouses, tunnels, etc. for greenhouse cultivation of crops, and an agricultural film prepared therefrom.

Greenhouse cultivation for growing crops, horticultural crops, etc. by using houses or tunnels is to artificially regulate the appropriate cultivation environment for growing crops so that crops can be grown at times when it is impossible or at low productivity to raise productivity. Therefore, it is very important to install the facilities such as vinyl house and tunnel for greenhouse cultivation in consideration of the characteristics for maintaining the cultivation environment, such as solar permeability, heat insulation, heat insulation, etc., since the facilities such as greenhouses and tunnels for greenhouse cultivation should be maintained.

Greenhouse cultivation is mainly used polyvinyl chloride film, polyethylene film, ethylene vinyl acetate copolymer film, and cultivated by blending additives or stacking two or more films in the film manufacturing process. The characteristics of the environment are being improved.

As a prior art related to agricultural films used in greenhouses, tunnels, etc. for greenhouse cultivation, for example, in the Korean Registered Patent Publication No. 10-0416863, a compound hydroxide condensation silicate specific to vinyl chloride resin is compounded, and infrared absorption ability is high, Disclosed is an excellent agricultural film having excellent heat retention and transparency, and in the Korean Patent Publication No. 10-0519401, UV light in a synthetic resin selected from the group consisting of ethylene vinyl acetate copolymer, low density polyethylene, linear low density polyethylene and mixtures thereof The present invention discloses a packaging or agricultural film in which an ultraviolet absorber and a heat insulating property are complementarily increased by blending an absorbent and an average particle size of 2 to 20 µm and alumina silica-based hollow inorganic particles containing iron oxide. Publication No. 10-0984329 has poly 0.5 to 1.0 parts by weight of near infrared absorbing pigments and 0.01 to 0.2 parts by weight of fluorescent dyes for light conversion based on 100 parts by weight of a synthetic resin substrate selected from the group consisting of ethylene resin, polypropylene resin, ethylene vinyl acetate copolymer resin and polyvinyl chloride resin However, there is disclosed a functional agricultural film having a light selective transmittance, characterized in that the transmittance of near infrared region having a wavelength of 750 nm to 1,200 nm is 40 to 60%.

The present invention has completed the present invention by developing a molding composition of agricultural films suitable for greenhouses, tunnels for greenhouse cultivation from agricultural film compositions with improved thermal insulation and insulation.

The present invention has an object to provide an agricultural film composition for use in greenhouses, tunnels, etc. for greenhouse cultivation of agricultural crops and agricultural films prepared therefrom, and more specifically, agricultural films for use in greenhouses, tunnels, etc. for greenhouse cultivation. It is an object of the present invention to provide an agricultural film composition and an agricultural film produced therefrom which has improved thermal insulation and thermal insulation properties in accordance with the visible and infrared ray transmittances.

As a solution for achieving the object of the present invention, an agricultural film composition having improved thermal insulation and thermal insulation is a polymer obtained by grafting airgel (Aerogel) and linear low density polyethylene (LLDPE) to maleic anhydride on a polyethylene-based polymer resin (PE-g- MAH) or an olefin wax, and in detail, (a) at least one selected from low density polyethylene (LDPE) and linear low density polyethylene (LLDPE) as the first component. For 100 parts by volume of polyethylene-based polymer resin, (b) 20 to 50 parts by volume of silylated aerogel or surface modified hydrophilic aerogel (Aerogel) as a second component, and (c) a linear low density polyethylene (LLDPE) as a third component 2-8 parts by weight of a polymer (PE-g-MAH) grafted) with maleic anhydride), and (d) polyethylene wax and silicone-modified polyethylethylene as a fourth component. It is made to contain the one or more components selected from one to two parts by the wax is not blended or blended, is made to be added to the composition of a functional aid.

Low Density Polyethylene (LDPE) and Linear Low Density Polyethylene (LLDPE), which are the first component according to the present invention, are polyethylene synthetic resins prepared by polymerizing ethylene together. Low Density Polyethylene (LDPE) is colorless and transparent. It is excellent in cold resistance, electrical insulation and chemical resistance, and has good processability and low price, so it is widely used as food bag, shopping bag, agricultural film, and linear low density polyethylene (LLDPE) is characterized by low density polyethylene (LDPE). It is similar to, but is higher than low density polyethylene (LDPE) in terms of strength and excellent in optical properties, it is widely used in agricultural films such as hotbeds, tunnels, thermal insulation nails.

Aerogel, the second component of the agricultural film composition of the present invention, is a low-density material having a nanoporous structure, which has high light transmittance and low thermal conductivity, and exhibits a melting point of more than 1000 ° C. It is applied in various fields such as ash, heat insulating material, noise shielding material, and in the present invention, porosity 80 ~ 99.8%, particle size 10 ~ 100nm, refractive index 1.007 ~ 1.05. It consists of selecting a silylated airgel (Aerogel) or surface modified hydrophilic airgel (Aerogel) with a thermal conductivity of 10 to 20 mW / mK.

The silylation airgel (Aerogel) is to increase the hydrophobicity of the aerogel (Aerogel) by the silylating agent is higher hydrophobicity than the aerogel (Aerogel) is to protect the pores of the airgel (Aerogel) from moisture in the air, so porous aerogel (Aerogel) Since it is formulated while keeping it safe, the porosity characteristics of the aerogel can be more fully realized.

In addition, the surface-modified hydrophilic airgel (Aerogel) is a hydrogel modified surface of the airgel by a surfactant, the aerogel is hydrophilic surface-only hydrophilized uniformly mixed with the organic material, when mixed with the organic material hydrophilic surfactant formed on the surface The membrane prevents the organic material from penetrating into the airgel voids, thereby maintaining the high specific surface area and porosity of the airgel, thereby fully realizing the unique characteristics of the airgel.

The silylated airgel (Aerogel) or surface-modified hydrophilic aerogel (Aerogel) is a commercially known material (ISA firm, REM Tech, etc.) is commercially available, the higher the compounding amount, the higher the thermal insulation and insulation, but the low density polyethylene (LDPE) and linear Compared to low density polyethylene (LLDPE), the density is very low, and the mixing ratio is 50% or more in volume fraction, which makes it difficult to mix uniformly. It consists of 20-50 parts with respect to 100 parts of system resin .

The polymer obtained by grafting linear low density polyethylene (LLDPE), the third component selected in the present invention, with maleic anhydride (LLDPE-g-MAH) has a high affinity with the polyethylene resin, and in particular, low density polyethylene (LDPE) And a component suitable for maintaining the properties of the aerogel, which is very advantageous in obtaining a uniform molding mixture by improving the miscibility of linear low density polyethylene (LLDPE) and a silylated aerogel or a surface modified hydrophilic aerogel. It is preferable to mix | blend 2-8 parts with respect to 100 parts of said polyethylene-type resin by the volume unit of silver.

In addition, the fourth component, polyethylene wax or silicone-modified polyethylene wax, is a component that improves lubricity and releasability when molded into a film using a film composition, and at the same time, when the above-mentioned aerogel and an additional functional aid are blended, The fourth component is blended according to the formulation of the polymer (LLDPE-g-MAH) grafted with the linear low density polyethylene (LLDPE), which is the third component, with maleic anhydride. If not, the compounding ratio is preferably 1 to 2 parts based on 100 parts of the polyethylene resin by volume unit.

The agricultural film composition according to the present invention is a functional supplement is composed as an additional component, the functional assistant is composed of one or more components selected from UV blockers, antioxidants, antistatic agents and thermostabilizers are further composed, the mixing ratio is volume It consists of 1-2 parts each mix | blending with respect to 100 parts of said polyethylene resin by a unit.

And another object according to the invention is made of an agricultural film molded using the agricultural film composition of the present invention, the agricultural film of the present invention when used in a greenhouse or tunnel for greenhouse cultivation of horticultural crops, crops, Since the heat inside the house raised by light transmission is not lost to the outside, the thermal insulation power is very excellent.

The present invention relates to the miscibility of aerogels by selecting a polymer (LLDPE-g-MAH) grafted linear low density polyethylene (LLDPE) with maleic anhydride, which is a suitable additive, to obtain a uniform molding composition from low density polyethylene or linear low density polyethylene and aerogels. In addition, it is possible to secure the inherent properties of the airgel without adversely affecting the physical properties of the film by forming the film, and to prevent heat from rising inside the house due to light transmission to the outside. There is a characteristic that can produce an agricultural film.

1 is a graph of a comparison test of the change in the internal temperature of the greenhouse by the heating of the agricultural film of the present invention.

Figure 2 is a graph comparing the change in the internal temperature of the greenhouse according to the solar transmission of the agricultural film of the present invention

Hereinafter, the present invention will be described in more detail with reference to Examples and Test Examples. The present invention is not limited by the following description, and the parts and percentage units used in the present invention are all represented by volume unless otherwise specified. will be.

<Example>

The molding composition of the composition ratio as shown in Table 1 below was melted, kneaded and pelletized to prepare a masterbatch, and then an agricultural film having a thickness of 50 μm was prepared according to a conventional film forming method.

Table 1

ingredient	Composition ratio (unit; volume part)
	Example 1	Example 2	Example 3	Where to buy
LDPE Resin	100	100	100	Comet Chemical
Silylation Aerogels	50	25	-	ISA Corporation
Hydrophilic Airgel	-	-	25	REM Tech
LLDPE-g-MAH	6	3	3	Welcome Tech
Olefin Wax	-	One	2	Comet Chemical
Silylated olefin wax	-	2	-	Comet Chemical

<Test Example 1>

In order to test the warmth by heating, a simple vinyl house made of 1m x 1m x 1m (width x height x height) of the agricultural film manufactured in Example 1 and the commercial agricultural film, respectively, was installed indoors, and then, simple vinyl. The inside of the house was heated for about 1 hour with the heater of the heater (350W / h) and observed the temperature change inside the simple vinyl house, and the results are shown in Table 2 below, and attached to [Figure 1].

TABLE 2

division	Temperature over time (℃)
	start	10 minutes	20 minutes	30 minutes	40 minutes	50 minutes	60 minutes
Test Example 1	26.4	29.0	31.5	33.1	33.9	34.4	34.6
Comparative Example 1	26.4	28.2	29.4	29.8	30.1	30.2	30.2

As shown in [Table 2] above, it is a simple test for a simple vinyl house having a volume of 1 m 3, but the internal temperature of the vinyl house of the present invention is 4.4 ° C., compared to the internal temperature of the vinyl house produced by commercially available agricultural films. The higher the temperature difference (maximum temperature), the higher the indoor temperature, the agricultural film of the present invention can be confirmed that less heat loss during the heating process due to the effect of improving the thermal insulation or thermal insulation, the agricultural film of the present invention to heating It can be predicted that the required cost can be saved.

<Test Example 2>

In order to test the temperature change inside the house due to solar transmission, a simple vinyl house manufactured at 1 m x 1 m x 1 m (width x height x height) of the agricultural film manufactured in Example 3 and the agricultural film, respectively, at room temperature 1 After exposure to the sun for about 6 hours at around 10 June 2014, the temperature change in each of the simple vinyl houses was observed, and the results are shown in Table 3 below and attached to FIG. 2.

TABLE 3

division	Temperature over time (℃)
	start	10 minutes	20 minutes	30 minutes	40 minutes	50 minutes	60 minutes
Test Example 2	30.2	39.3	42.7	44.2	45.5	44.1	43.9
Comparative Example 2	30.5	36.8	41.4	43.8	44.0	43.8	37.3

According to the above [Table 3], it can be seen that the temperature change of the inside of the house due to solar transmission also maintains a higher temperature than the agricultural film of the present invention compared with the comparative example, and these test results show that the agricultural film of the present invention. It can be seen that the infrared transmittance and the heat insulating property are higher than that of the comparative example, and therefore, it can be seen that the agricultural film of the present invention is advantageous in terms of energy efficiency.

The uniform molding composition of low density polyethylene or linear low density polyethylene and aerogel of the present invention can be molded into a film without adversely affecting physical properties, so that heat inside the house raised by light transmission is not lost to the outside. It can be used very well as an agricultural film with excellent heat insulation and heat insulation.

Claims (5)

1. (a). For 100 parts by volume of one or more polyethylene polymer resins selected from Low Density Polyethylene (LDPE) and Linear Low Density Polyethylene (LLDPE) as the first component,

   (b) 20 to 50 parts by volume of at least one component selected from surface modified hydrophilic aerogels and silylated aerogels as a second component,

   (c). As a third component, 2-8 parts of polymer (LLDPE-g-MAH) grafted linear low density polyethylene (LLDPE) with maleic anhydride is blended,

   (d). An agricultural film composition with improved thermal insulation and insulation properties, comprising blending or not blending one or two parts of at least one component selected from polyethylene wax and silicone modified polyethylene wax as a fourth component.
2. The method according to claim 1, wherein at least one component selected from UV blocking agents, antioxidants, antistatic agents and thermostabilizers as a functional aid to the agricultural film composition is added to 1 to 2 parts of each volume relative to 100 parts of polyethylene polymer resin. Agricultural film composition with improved thermal insulation and insulation.
3. The method of claim 2, wherein the second component is a silylated aerogel (Aerogel) having a characteristic of the porosity of 80 ~ 99.8%, particle size 10 ~ 100nm, refractive index 1.007 ~ 1.05, the fourth component is a silicone modified polyethylene wax Agricultural film composition with improved insulation and insulation.
4. The method of claim 2, wherein the second component is a surface modified hydrophilic aerogel (Aerogel) having a characteristic of the porosity of 80 to 99.8%, particle size of 10 to 100nm, refractive index of 1.007 to 1.05, the fourth component is polyethylene wax Agricultural film composition with improved insulation and insulation.
5. Agricultural film with improved thermal insulation and heat insulation, characterized in that produced by molding the agricultural film composition of any one of claims 1 to 4.

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