JPH01236275A - Agricultural synthetic resin film - Google Patents

Abstract

PURPOSE:To impart fog-preventing property excellent in durability and improved in the occurrence of high-temperature damage, by adding a nonionic hydrocarbon surfactant and a perfluoroalkoxy fluorine compound to a synthetic resin. CONSTITUTION:This film is formed from a composition prepared by adding 0.5-5pts.wt. nonionic hydrocarbon surfactant (b) such as sorbitan monostearate, (di)glycerol monostearate or polyethylene glycol monostearate and 0.01-0.5pt.wt. fluorine compound (c) of any one of formulas I-III [wherein R1fO is a 2-6C liner or branched perfluoroalkoxy, R2f is a 2-12C linear or branched perfluoroalkylene, R1 is a 1-12C linear or branched alkylene, A is O or NH, B is a group of any one of formulas IV-VI (wherein n=2-30, p and q are each 1-29, and p+q=n)] to 100pts.wt. synthetic resin (a) such as a vinyl chloride resin, a vinyl chloride/vinyl acetate copolymer resin, PE, PP, an ethylene/ vinyl acetate copolymer resin or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a film for covering a greenhouse used for cultivating useful plants. More specifically, the present invention relates to a synthetic resin film that contains a specific fluorine-containing compound and a hydrocarbon nonionic surfactant and has excellent antifogging and misting properties.

[Prior art]

Conventionally, soft resin films such as vinyl chloride resin films and ethylene resin films have been frequently used as covering materials for greenhouse horticulture. The synthetic resin film usually contains a nonionic surfactant such as sorbitan or glycerin in order to prevent fogging caused by water droplets adhering to the film surface. In addition, in order to prevent the moisture in the air inside the greenhouse from liquefying due to temperature differences inside and outside the greenhouse and floating inside the greenhouse in the form of mist, we have developed a limb covering material containing a silicone surfactant (Japanese Patent Laid-Open Publication No. 1983-1992). No. 91663), a coating material kneaded with a fluorine-based surfactant containing a perfluoroalkyl group or a perfluoroalkenyl group (Japanese Patent Publication No. 1983,
An agricultural and horticultural film (Japanese Patent Publication No. 62-18579) has been proposed, which contains a copolymerized oligomer of acrylate or methacrylate-1 containing a terminal perfluoro group and a compound that can be copolymerized. ing.

[Problem that the invention seeks to solve]

Agricultural covering films are used outdoors and under various temperature and humidity conditions for long periods of time, so they require various properties as covering films.

The inventor of the present invention found that the antifogging performance of the coating film added with the above-mentioned silicone-based and fluorine-based compounds is partially reduced when the temperature inside the greenhouse rises, causing droplets to form. There has been a problem in that a phenomenon in which the state changes (hereinafter this phenomenon may be referred to as high-temperature damage) occurs. Since greenhouses are facilities whose main purpose is to maintain heat, each crop is maintained within the maximum and minimum temperature ranges suitable for cultivation. Particularly during the daytime hours when the sun is shining, efforts are made to manage the temperature inside the greenhouse so that the temperature rises to the maximum temperature that is appropriate for the growth stage of the crop, in order to ensure the lowest nighttime temperature. . When the inside of the greenhouse is kept under high temperature control and the anti-fogging properties of the inner surface of the film are reduced due to the occurrence of high temperature damage, water droplets will fall from the part of the film where the high temperature damage has occurred, hitting the crops planted at the bottom of the drop, causing the crops to fall. It is susceptible to sclerotia, gray mold, etc., and may even die off, so the occurrence of high-temperature damage is a serious problem. However, the reason why an antifogging film provided with antifogging properties tends to lose its antifogging properties in a portion of the film under high temperature conditions and cause a dripping state to occur is not clear.

[Means to solve the problem]

As a result of intensive research to improve high temperature damage, the inventor of the present invention found that
Per 100 parts by weight of synthetic resin, 0.5 to 5 parts by weight of a hydrocarbon nonionic surfactant and 0.01 to 5 parts by weight of a fluorine-containing compound containing a perfluoroalkoxy group having 2 to 6 carbon atoms.
The inventors have discovered that a synthetic resin film containing 0.5 parts by weight can solve these problems, leading to the present invention.

The present invention will be explained in more detail below.

In the present invention, synthetic resins include vinyl chloride resins, copolymers of vinyl chloride and other monomers such as vinyl acetate, ethylene, propylene, etc., and copolymers of these resins and chlorinated polyethylene, chlorinated polypropylene, and chlorinated polyisobutylene. or blends with copolymers, ethylene-based resins such as polyethylene, polypropylene, and copolymer resins of ethylene and vinyl acetate.

The hydrocarbon-based nonionic surfactant must be able to prevent deterioration of the weather resistance of the film as much as possible and have excellent anti-fogging properties, such as sorbitan monopalmitate, sorbitan monostearate, and sorbitan monobehenate. , sorbitan surfactants such as sorbitane dipalmitate, sorbitane distearate, sorbitane dibehenate, glycerin surfactants such as glycerin monopalmitate, glycerin monostearate, diglycerin monostearate, diglycerin distearate, etc. polyethylene glycol surfactants such as polyethylene glycol monopalmitate and polyethylene glycol monostearate, and esters of sorbitan/glycerin condensates and organic acids. These surfactants can be used alone or in combination of two or more. The hydrocarbon nonionic surfactant is used in an amount of 0.5 to 5 parts by weight per 100 parts by weight of the synthetic resin.

If the amount is less than 0.5 part by weight, sufficient antifogging durability cannot be obtained. If more than 5 parts by weight is used, the weather resistance will be significantly reduced.
Moreover, it is unsuitable because it causes a bloom phenomenon on the film surface and promotes staining of the film.

As the fluorine-containing compound containing a perfluoroalkoxy group having 2 to 6 carbon atoms, for example, those listed in (a), (U), and (c) can be used.

In the formula, R,,0 is a straight chain or branched perfluoroalkoxy group having 2 to 6 carbon atoms, R2f is a straight chain or branched perfluoroalkylene group having 2 to 12 carbon atoms, and R1 is a straight chain or branched perfluoroalkoxy group having 2 to 6 carbon atoms. 12 straight or branched alkylene groups, A is oxygen or NH, B is +C) 12c) 120 +-Fr-1÷
ct+(co,)cH2o-)-0, (-CH2CH
20←÷C1 ((C)!3)C) 120-7-9 (however, n = 2 to 30. p = 1 to 29, q = 1 to 29, p + q =
n), C is hydrogen, an alkyl group having 1 to 5 carbon atoms,
phenyl group or alkylphenyl group, m is 1 or 0;

Specific examples of these fluorine-containing compounds containing a perfluoroalkoxy group having 2 to 6 carbon atoms are as follows. However, it is not limited to the following.

C00(C)12C)120)1oH OOH Cool( CH2CUNH(1;t12);113U712u11
3 cu2 coon These fluorine-containing compounds are used in a range of 0.01 to 0.5 parts by weight. If the amount is less than 0.01 part by weight, the anti-fog properties will be poor and it cannot be used. If more than 0.5 parts by weight is used, high temperature damage to antifogging properties will not be improved and it is unsuitable. These fluorine-containing compounds can be used alone or in combination of two or more.

Further, in the present invention, when the synthetic resin is a vinyl chloride resin, it is preferable that a phosphorus compound as described below is blended to improve the sustainability of the fog prevention property.

In the formula, R2, R3, R4, and R5 are alkyl groups or alkenyl groups having 12 to 22 carbon atoms, and M is zinc, calcium, or barium. A specific example is as follows.

The synthetic resin may contain plasticizers, ultraviolet absorbers, heat stabilizers, light stabilizers, antifungal agents, lubricants, colorants, inorganic fillers, organic fillers, Compounds such as processability improving aids, infrared absorbers, and epoxy stabilizing aids can be added.

〔Example〕

EXAMPLES Below, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Examples 1 to 4, Comparative Examples 1 to 4 Each of the compositions shown in Table 1 was formed into a film with a thickness of 0.1 m/m using a calendar roll mill.

The evaluation was performed by the following method and the results are shown in the lower column of Table 1.

Fog-proof evaluation method Each film was spread in a tunnel house with a width of 1.2 m, a height of 1.2 m, and a length of 7 m in December, and the fog generation inside the tunnel house was visually observed and evaluated according to the following criteria.

4; There is a lot of fog (you can't see 7 meters ahead.

3; There is a lot of fog.

2; Slightly foggy.

1; There is a slight amount of fog.

0: No fog was generated at all.

High-temperature damage evaluation method The antifogging properties of the film spread on the tunnel house were visually observed during a time period when the temperature inside the house was 25 to 30°C, and evaluated using the following criteria.

4: Approximately 20% of the film area changes to a sentient state and high temperature damage is severe.

3: Approximately 15% of the film area changes to a sentient state, resulting in high temperature damage. Middle 2: Approximately 10% of the film area changes to a sentient state, resulting in high temperature damage. Elementary 1: Approximately 5% of the film area changes to a sentient state, resulting in high temperature damage. Slight 0: No high temperature damage occurred Example 5, Comparative Examples 5 to 6 Each of the compositions shown in Table 2 was molded into a film with a thickness of 0.075+n/m using an inflation extruder.

The evaluation method was the same as in the above example.

Table 2 [Effects] Since the film of the present invention has a specific resin composition,
As shown in the examples, it can be seen that the product has excellent fog-proofing properties, excellent long-lasting performance, and improved occurrence of high-temperature damage.

It is an extremely useful film that has high levels of properties required as an agricultural covering film.

Claims (2)

[Claims] (1) 0.5 to 5 parts by weight of a hydrocarbon nonionic surfactant and 0.5 to 5 parts by weight of a fluorine-containing compound containing a perfluoroalkoxy group having 2 to 6 carbon atoms per 100 parts by weight of synthetic resin.
An agricultural synthetic resin film characterized by containing 01 to 0.5 parts by weight. (2) The fluorine-containing compound containing a perfluoroalkoxy group having 2 to 6 carbon atoms has the general formula (a), (b), or (c).
The agricultural synthetic resin film according to claim 1, characterized in that it is at least one type of agricultural synthetic resin film. ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (A) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (B) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (C) In the formula, R_1_fO has 2 to 6 carbon atoms. straight or branched perfluoroalkoxy group, R_2_f has 2 to 1 carbon atoms
2 straight or branched perfluoroalkylene groups, R_
1 is a straight chain or branched alkylene group having 1 to 12 carbon atoms,
A is oxygen or NH, B is ■CH_2CH_2O■_n,
■CH (CH_3) CH_2O■_n, ■CH_2CH
_2O■CH (CH_3) CH_2O■_q (however, n=
2-30, p=1-29, q=1-29, p+q=n)
, c represents hydrogen, an alkyl group having 1 to 5 carbon atoms, a phenyl group or an alkylphenyl group, and m represents 1 or 0.