JPH0695862B2 - Method for producing vinyl chloride resin film for agriculture - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a vinyl chloride resin film for agriculture. More specifically, the present invention relates to a method for producing an anti-adhesive agricultural vinyl chloride resin film that recovers transparency after spreading.

[0002]

2. Description of the Related Art Agricultural vinyl chloride resin films prepared by blending a large amount of plasticizer with vinyl chloride resin are generally manufactured continuously by extrusion molding and calendering, and the film is wound into a roll. Used for transportation, storage and use. The agricultural vinyl chloride resin film is subjected to so-called secondary processing such as welder processing while being unwound from the rolled film wound into a roll. On the other hand, an agricultural vinyl chloride resin film formed by blending a plasticizer in a vinyl chloride resin as a base material with 30 PHR or more has a sticky film surface, and a film wound in a roll has the surfaces attached to each other. easy. Further, the surfaces of the products obtained by the secondary processing adhere to each other, and the workability such as spreading work is extremely poor. Therefore, when the secondary processing is performed, starch powder or the like is sprinkled to prevent tackiness. In addition, the film sprayed with starch powder is removed in a short period of time by the flow of rainwater or water droplets generated in the house,
The transparency can be restored. However, when spraying a powder for preventing sticking such as starch powder on the film surface in a secondary processing plant, not only the fine powder is scattered in the air and the working environment is significantly deteriorated, but also the loss of the fine powder is large. There is a problem. Therefore, as a means for eliminating the above problems, there is a method of spraying an anti-adhesive agent such as starch powder and talc on the surface of the film immediately before being wound into a roll, but since starch powder has relatively large particles of powder, After winding, particles are difficult to film surface, the surface smoothness of the film is impaired, and because talc is difficult to remove from the film surface under the flow of rainwater or water droplets generated in the house, the transparency is poor. is there.

[0003]

DISCLOSURE OF THE INVENTION According to the present invention, when a vinyl chloride resin film for agriculture is wound up, a predetermined fine silica powder is sprinkled to improve the tackiness and solve the problem of poor transparency after spreading. Is intended.

[0004]

According to the present invention, a resin composition containing 30 to 100 parts by weight of a plasticizer per 100 parts by weight of a vinyl chloride resin is formed into a film, and the film is wound on a roll at least on one side. The average particle size of 1-5μ
Then, a method for producing a vinyl chloride resin film for agricultural use with improved tackiness, characterized in that fine silica powder having an apparent specific volume of 1 ml / g or more is dispersed and adhered.

The present invention will be described in detail below. In the present invention, the vinyl chloride-based resin refers to a copolymer of polyvinyl chloride and other comonomer mainly containing vinyl chloride, a mixture thereof, or a mixture of these with another polymer or copolymer. . Vinyl chloride-based resins include, in addition to plasticizers generally used for agricultural vinyl chloride-based resin films, various ordinary resin additives such as anti-fog agents, lubricants, antioxidants, ultraviolet absorbers, and light Stabilizers, dyes, pigments and the like can be added. These additives are added in a usual amount, for example, 100 parts by weight of vinyl chloride resin,
It can be used in an amount of 10 parts by weight or less. To mix a plasticizer and various resin additives with the base vinyl chloride resin, use a conventional mixing and compounding technique such as a ribbon blender, a Banbury mixer, a super mixer or other conventionally known compounding machine or mixer. good. Techniques such as an extrusion molding method such as a T-die method and an inflation method, a calender molding method, and a casting method can be adopted for forming the vinyl chloride resin composition into a film. The silica fine powder is applied to at least one surface of the film before the film is wound into a roll. As a spraying method, there are an electrostatic duster method utilizing electrostatic charging of the silica fine powder and a spray spray method of an aqueous dispersion of the silica fine powder. The silica to be sprinkled can be used as it is, or after being subjected to a commonly used surface treatment such as silicon oil or a fluorine-based compound. The fine silica powder to be sprayed has an average particle size of 1 to 5
is μ. If the average particle size is smaller than 1 μ, the particles are strongly aggregated with each other, the adhesion between the particles and the film base material is strong, the particles are hardly peeled off from the film surface, and the transparency after running water is poor, which is not preferable. . If the average particle size is larger than 5μ, even if the particles are evenly attached to the film surface, the particles are difficult to roll due to the winding pressure in the process of winding and storing the film in a roll shape, and the film surface is grainy (small irregularities on the surface). Is formed, and the smoothness is lost and the transparency is lowered, which is not preferable.

The apparent specific volume of fine silica powder is 1 ml /
g or more. If the apparent specific volume is less than 1 ml / g,
If it is not adhered in a large amount, the film surface has almost no anti-adhesion effect, and it becomes difficult for the adhered matter to be peeled off from the film surface due to rainwater or water droplets generated in the house, and the transparency is not restored. The amount attached to the film surface is
Of the plasticizer to be blended into a film, the amount of the plasticizer can be selected variously by the secondary processing system or the like of the film, is preferably in the range of ^{0.01g / m 2 ~2g / m 2} , further 0.1g / m ² ~1g / m ² is particularly preferred. If the adhesion amount is less than 0.01 g / m ² , the film surface has almost no anti-adhesion effect, and if it is more than 2 g / m ² , the adhesion amount is too large and fine powder is partially deposited on the film, It is not preferable because it impairs the smoothness of the surface.

A small amount of conventionally known anti-sticking agent such as starch or talc may be mixed in the fine silica powder to be dispersed on the surface of the film. The mixing ratio in this case can be appropriately selected according to the degree of tackiness. After the fine silica powder is sprinkled on the film surface, the film is wound by a conventionally known film winding method such as a center winder or a surface winder to obtain a roll-shaped product. Further, the vinyl chloride resin film for agriculture according to the present invention can be used for cultivation of useful plants by spreading it in agricultural and horticultural facilities such as houses and tunnels in the same manner as conventional covering materials for agriculture. it can.

[0008]

Industrial Applicability The method for producing an agricultural vinyl chloride resin film according to the present invention is an anti-adhesive agricultural use in which fine silica powder is sprinkled before rolling into a roll form so as not to impair the smoothness and transparency of the film surface. By producing a vinyl chloride resin film, the workability is good without shaking starch powder or the like during the secondary processing, so the agricultural utility value of the present invention is great.

[0009]

EXAMPLES The present invention will be described in detail below based on examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. Examples 1-5, Comparative Examples 1-8 Polyvinyl chloride (degree of polymerization = 1300) 100 parts by weight Dioctyl phthalate As shown in Table 1, tricresyl phosphate 5 parts by weight Epoxy resin 2 parts by weight Ba-Zn-based liquid Stabilizer 2 parts by weight Ba-Zn-based powder stabilizer 1 part by weight Sorbitan monopalmitate 1.5 parts by weight A raw material and a resin additive were weighed. These were stirred and mixed with a super mixer for 10 minutes, and then kneaded on a roll heated to 165 ° C. to produce a transparent soft polyvinyl chloride film having a width of 100 cm and a thickness of 0.05 mm by an L-type calender device. .

The film after coming out of the calender roll is brought into contact with a cooling roll to keep the film temperature at 40
It was cooled to below ℃. On one side of this film, use a drum type fine powder spray machine (nicker spray device) to
For various fine powders shown in the table, the adhesion amount was 0.7 g /
It was adjusted to m ² and sprayed. (However, Comparative Example 8
Was not sprayed. ) 13 rolled up
The seed film was left in a roll form for 2 weeks in an atmosphere at a temperature of 40 ° C. and a relative humidity of 90%, and then the film was evaluated for tackiness, surface smoothness and transparency after washing with water. .

The results are shown in Table 1. Cut a 50 cm square film from the adhesive roll and cut it into 4
Fold it in half and put a load of 30 kg on it.
In the atmosphere kept at, leave it for 24 hours, take the load,
The state of adhesion between the film surfaces when the film was unraveled was observed. The evaluation results shown in Table 1 have the following meanings.

○ Almost no tackiness △ Some tackiness × Remarkably tackiness After the surface tackiness was evaluated, the film was washed with water and the surface of the film was visually observed. The evaluation results shown in Table 1 have the following meanings.

○ The surface is extremely smooth. △ The surface has some irregularities. × The surface has considerable irregularities. A transparent film after running water is cut into a 50 cm square film and cut into 5 pieces.
The upper part of a water tank containing warm water kept at 0 ° C. was tilted at an angle of 45 degrees, sealed, and treated on both sides for 6 hours each, and the transparency of the dried film was visually evaluated. The evaluation results shown in Table 1 have the following meanings.

○ Transparency is good △ Transparency is slightly inferior × Transparency is inferior

[0015]

[Table 1]

Claims (1)

[Claims] 1. A resin composition containing 30 to 100 parts by weight of a plasticizer per 100 parts by weight of a vinyl chloride resin is formed into a film, and the average particle is formed on at least one side of the film before winding the film into a roll. A method for producing a vinyl chloride resin film for agricultural use with improved adhesiveness, which comprises spraying and adhering silica fine powder having a diameter of 1 to 5 µm and an apparent specific volume of 1 ml / g or more.