JPH04252115A - Vinyl chloride resin film for agricultural use - Google Patents

Abstract

PURPOSE:To provide a vinyl chloride resin film for agricultural use having excellent anti-block property and transparency. CONSTITUTION:The objective vinyl chloride resin film for agricultural use is produced by adding inert solid fine particles (e.g. hydrotalcite, magnesium carbonate, magnesium hydroxide and silicon oxide) in the polymerization of vinyl chloride and compounding a plasticizer to the obtained vinyl chloride resin containing the inert solid fine particles.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride resin film for agricultural use. More specifically, the present invention relates to an agricultural vinyl chloride resin film that is transparent, heat resistant, and non-adhesive.

0002

BACKGROUND OF THE INVENTION In recent years, in order to efficiently cultivate useful plants, accelerated cultivation in greenhouses or tunnels has become widely used. A vinyl chloride resin film is often used as a material for covering the house or tunnel because of its excellent weather resistance, transparency, heat retention, strength, etc. Vinyl chloride resin films usually have a plasticizer added to them, so they are soft and elastic, and have the advantage of being able to be easily stretched into any shape of house or tunnel. However, this film has the disadvantage that it is highly adhesive, which reduces the efficiency of spreading it into the house or tunnel, and after spreading, the efficiency of ventilation work and opening/closing work in the house or tunnel is low. It also has the disadvantage that the work efficiency of bonding them together using the high frequency bonding method is also reduced.

In order to improve this tackiness, polyethylene wax, alkaline earth metal salts of fatty acids, amide compounds, etc. are added as anti-tack agents; However, it has the disadvantage that it bleeds out onto the surface of the film and impairs the transparency of the film either by itself or due to the adhesion of dust.

[0004] Furthermore, in the method of adding inorganic solid particles,
Although the anti-adhesive properties (non-adhesiveness) were improved, it was difficult to obtain a film with transparency.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an agricultural vinyl chloride resin film that is both transparent and non-adhesive.

[0006]

[Means for Solving the Problems] As a result of studies to achieve the above-mentioned object, the present inventors have found that by adding inert solid fine particles during vinyl chloride polymerization, good non-adhesiveness and The present invention was achieved by discovering that a film having both transparency can be obtained. Therefore, the gist of the present invention is to provide an agricultural chloride resin containing a plasticizer to a vinyl chloride resin containing inert solid particles obtained by adding inert solid particles during vinyl chloride polymerization. In vinyl resin film.

The present invention will be explained in detail below. In the present invention, the vinyl chloride resin includes polyvinyl chloride, a copolymer mainly composed of vinyl chloride with other comonomers, a mixture thereof, or a mixture of these with other polymers or copolymers. In the present invention, inert solid particles added during polymerization include magnesium carbonate, silicon oxide, aluminum oxide, barium sulfate, calcium sulfate, magnesium hydroxide, aluminum hydroxide, calcium hydroxide, metal phosphate, and hydrotalcite. (hydrated or anhydrous aluminum/magnesium basic carbonates, sulfates, nitrates, phosphates; aluminum/zinc basic carbonates, sulfates, nitrates, phosphates). Aluminum oxide, magnesium hydroxide, silicon oxide, magnesium carbonate, and hydrotalcites are particularly preferred because they do not reduce the transparency of the film.

[0008] These inert solid fine particles are suitably added in an amount of 1 to 10 parts by weight per 100 parts by weight of the vinyl chloride resin. When the content of the inert solid fine particles is less than 1 part by weight, the effect of improving non-adhesion is not sufficient, while when it is more than 10 parts by weight, the transparency of the film is impaired. Various known methods can be applied to polymerize the vinyl chloride resin containing inert solid fine particles. For example, any known method such as suspension polymerization, emulsion polymerization, or bulk polymerization may be used. The agricultural vinyl chloride resin film of the present invention is blended with a plasticizer and used as a soft film. Examples of plasticizers include G-n-
Octyl phthalate, di-2-ethylhexyl phthalate, dibenzyl phthalate, diisodecyl phthalate,
Phthalate esters such as didodecyl phthalate and diundecyl phthalate, isophthalate esters such as diisooctyl isophthalate, di-n-butyl adipate,
Fatty acid esters such as dioctyl adipate, di-n-
Maleic acid esters such as butyl maleate, tri-n-
Citric acid esters such as butyl citrate, itaconic esters such as monobutyl itaconate, oleic esters such as butyl oleate, ricinoleic esters such as glyceryl monoricinolate, and other phosphate esters such as tricresyl phosphate. system, epoxidized soybean oil,
Various epoxy plasticizers such as epoxy resins may be mentioned, and these may be used alone or in combination. The appropriate blending ratio for the vinyl chloride resin is 30 to 60 parts by weight per 100 parts by weight of the vinyl chloride resin (inert solid particles are not included in the calculation; the same applies hereinafter).

[0009] The agricultural vinyl chloride resin film of the present invention may contain additives normally added to vinyl chloride resins, such as antifogging agents, antifogging agents, lubricants, heat stabilizers, and antistatic agents, if necessary. , an ultraviolet absorber, and a coloring agent may be added. The agricultural vinyl chloride resin film of the present invention is prepared by adding and blending a plasticizer and various additives as necessary to a vinyl chloride resin containing inert solid particles, and then using a known method such as melt extrusion. It can be manufactured by various molding methods such as a calendar molding method and a melt casting method. Agricultural vinyl chloride resin film has a temperature of 130 to 200 when molded.
It is desirable that the film be stretched uniaxially or biaxially at a temperature of 20 times or less in area ratio, preferably about 1.5 to 10 times. At this time, the inert solid fine particles are uniformly exposed on the film surface, and the non-adhesive effect of the film can be improved without reducing the transparency.

[0010] The thickness of the film is 0.03 to 0.5 mm, preferably 0.03 to 0.5 mm, taking into consideration strength, production cost, etc.
It is preferable to set it in the range of 0.05 to 0.3 mm. Furthermore, the agricultural vinyl chloride resin film according to the present invention can be spread over agricultural and horticultural facilities such as greenhouses and tunnels and used for cultivating useful plants in the same way as conventional agricultural covering materials. Can be done.

[0011]

Effects of the Invention: The agricultural vinyl chloride resin film of the present invention is produced by adding inert solid fine particles during vinyl chloride polymerization, so that it can be produced by adding inert solid fine particles during vinyl chloride polymerization, so that it can be produced by adding inert solid particles during vinyl chloride polymerization. Compared to the case where inert solid particles are blended with the film, it has a non-adhesive effect and has improved transparency and heat resistance, so it is suitable for agricultural films to be spread outdoors.

0012

EXAMPLES Next, the present invention will be explained in detail based on examples, but the present invention is not limited to the following examples unless it departs from the gist thereof. Example 1 (i) Production of vinyl chloride resin containing inert solid particles 140 kg of water, 5 kg of hydrotalcite (aluminum/magnesium basic carbonate, average particle size 0.5 μm, spherical)
After putting 0.05 kg of dispersant (polyvinyl alcohol) and 0.05 kg of initiator (peroxy ester) into an autoclave and degassing, 90 g of vinyl chloride monomer was added.
kg was charged and polymerization was carried out at 51° C. for 6 hours while stirring. After centrifuging this reaction product, it is dried to obtain the desired product (
Hydrotalcite-containing polyvinyl chloride, average degree of polymerization 1
300, equivalent to 7 parts by weight of hydrotalcite) was obtained.

(ii) Production of film 100 parts by weight of the hydrotalcite-containing vinyl chloride resin produced in (i) (however, hydrotalcite is not included in the calculation) was mixed with the following composition in a Henschel mixer. After stirring and mixing, the mixture was kneaded on a roll heated to 170°C, and a film with a thickness of 0.075 mm was produced using a calendar roll at the same temperature. The film is stretched lengthwise between calender rolls and a winder to an area ratio of 6.

Di-2-ethylhexyl phthalate
45 parts by weight tricresyl phosphate
5 〃
Epoxy resin plasticizer (stabilizer, trade name Epicote 8)
28) 1 Barium-zinc composite liquid stabilizer
1 Barium stearate

0.2 Zinc stearate

0.4 Ethylene bisstearamide
0.3 Sorbitan monostearate
2.0 (iii)
Evaluation of Film The quality of the obtained film was evaluated by the following method, and the results are shown in Table 1. (1) Transparency For each sample film, the straight light transmittance at a wavelength of 555 nm was measured using a model 323 spectrophotometer manufactured by Hitachi, Ltd. The closer the straight light transmittance (transparency) is to 90%, which is the transmittance of a film that does not contain inert solid particles, the more transparent the film is. (2) Adhesiveness Two films of 30 mm x 100 mm were stacked and pressed together with rubber rolls to eliminate air between the films and bring them into close contact. This tightly attached film was heated at 30°C and 50°C.
The sample was placed in an oven set at a temperature of 70° C. and maintained at this temperature for 2 hours. Next, the films were taken out of the oven and left at room temperature for 15 minutes, and then the two films were peeled off using a tensile tester, and the peel stress at that time was measured. The unit of peel stress was the number of grams required to peel a 30 mm width.

(3) Heat resistance (thermal stability duration) 1mm
The duration of thermal stability was defined as the time required for a thick sheet to turn black in a 190°C gear oven. Examples 2 to 5 Vinyl chloride resins containing inert solid particles were produced in the same manner as in Example 1, except that the inert solid particles shown in Table 1 were blended in the amounts shown in Table 1, and film-formed. did.

The quality of each film obtained was evaluated in the same manner as in Example 1, and the results are shown in Table 1. Comparative Examples 1 to 5 In the examples, vinyl chloride resin containing inert solid particles was replaced with vinyl chloride resin containing no particles (average degree of polymerization 13).
00) A film was produced in the same manner as in Example 1, except that the inert solid particles shown in Table 1 were added in the amount shown in Table 1. Furthermore, the quality of the film was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0017]

[Table 1]

Claims (1)

[Claims] 1. An agricultural vinyl chloride resin film prepared by blending a plasticizer with a vinyl chloride resin containing inert solid particles obtained by adding inert solid particles during vinyl chloride polymerization.