JPH05123060A - Production of flexible vinyl chloride resin film for agricultural use - Google Patents

Abstract

PURPOSE:To obtain the subject product having stable quality, resistant to the blocking of films and capable of recovering the transparency after stretching by applying a specific treatment to a flexible vinyl chloride resin film before winding the film in the form of a roll. CONSTITUTION:At least a surface of a flexible vinyl chloride resin film is sprayed with an aqueous dispersion containing inorganic fine powder having an average particle diameter of 0.1-10gm (e.g. magnesium carbonate and silicon oxide) and a water-soluble polymer free from tackiness at ordinary temperature (e.g. PVA and CMC) in the form of droplets having an average particle diameter of 10-100mum. The treated film is dried and wound in the form of a roll.

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 soft vinyl chloride resin film for agriculture. More specifically, the present invention relates to a method for producing a soft vinyl chloride resin film for agriculture, in which the films do not stick to each other during the secondary processing and the house extension and the transparency is restored after the extension.

[0002]

2. Description of the Prior Art Agricultural soft vinyl chloride resin films prepared by blending a vinyl chloride resin with a plasticizer are generally manufactured continuously by extrusion molding, calender molding, etc.
After being rolled up, it is transported, stored and used.
So-called secondary processing such as welder processing is performed while rewinding the film from the wound film wound into a roll.

However, since the film contains a large amount of plasticizer, the film surface exhibits tackiness,
The film wound in a roll shape has a problem that the surfaces thereof are easily attached to each other, and the product obtained by the secondary processing has a problem that the surfaces are attached to each other and workability such as spreading work is extremely poor. In order to solve this problem, conventionally, by embossing the film, or by blending solid fine particles, the surface is roughened, the method of improving the workability by reducing the tackiness of the film, and the transparent method. A method has been used in which a starch powder or the like is sprayed when the film is secondarily processed to prevent sticking.

[0004]

However, the method of reducing the tackiness by embossing the film or blending solid fine particles into the film impairs the transparency of the film and prevents the crops in the house from being exposed to the outside. There was a drawback that you could not see it. Also, in the method of spraying starch powder or the like to prevent sticking, the transparency of the film is restored because the starch powder or the like is removed by rainwater or water droplets generated in the house in a short period of time. When spraying fine powder for adhesion prevention such as starch powder on the film surface in the 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 fine powder is caused. It had the drawback of being large. Therefore, as a means of solving this drawback, immediately before winding the film into a roll at the time of film production, a method of spraying an anti-adhesive agent such as starch powder or talc on the surface of the film can be considered. Because the powder particles are relatively large,
After winding, the particles have a drawback that the surface of the film is difficult to squeeze, and the surface smoothness of the film is impaired.Also, talc is difficult to remove from the film surface even when rainwater or water drops generated in the house flow down, and the film transparency There was a drawback that it was difficult to recover the sex.

Further, it is difficult to deposit fine powder of silicon oxide, calcium carbonate, etc. evenly on the film as it is. Especially, when the particle size is small, agglomeration easily occurs, resulting in poor dispersion. There was a problem to do. It is an object of the present invention to provide a film adhesion preventive processing method which does not have the above problems.

[0006]

However, the gist of the present invention is that during the production of a soft vinyl chloride resin film, before winding the film into a roll, at least one side of the film has an average thickness. Particle size 0.1-10μ
Characterized in that it is adhered by spraying an aqueous dispersion containing the inorganic fine powder and the water-soluble polymer that is non-adhesive at room temperature as droplets having an average particle size of 10 to 100μ, and then dried. And a method for producing a soft vinyl chloride resin film for agriculture.

The present invention will be described in detail below. In the present invention, as the vinyl chloride-based resin, use is made of a copolymer of polyvinyl chloride as well as another comonomer mainly containing vinyl chloride, a mixture thereof, or a mixture of these and another polymer or a copolymer. You can The soft vinyl chloride resin film of the present invention is a vinyl chloride resin 10
Although it contains 30 to 100 parts by weight of a plasticizer per 0 parts by weight, other various additives usually added to an agricultural film, such as a drip-free agent, a lubricant, an antifog agent, and a heat retaining agent, if necessary. Antioxidants, ultraviolet absorbers, light stabilizers, dyes, pigments and the like can be added, and these additives are added in a usual amount, for example, 1 part by weight per 100 parts by weight of vinyl chloride resin.
It can be used in an amount of 0 parts by weight or less.

In order to mix the plasticizer and various resin additives with the vinyl chloride resin, a conventional mixing technique such as a ribbon blender, a Banbury mixer, a super mixer, or a conventionally known mixer is used. well,
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 used for forming a film of the vinyl chloride resin mixture. Further, the surface of the film may be coated with an acrylic resin or the like by a gravure coating method, a reverse coating method or the like.

The inorganic fine powder used in the present invention includes magnesium carbonate, silicon oxide, aluminum oxide,
Barium sulfate, calcium sulfate, magnesium hydroxide,
Examples thereof include aluminum hydroxide and calcium carbonate, and these may be used alone or in combination of two or more kinds. The inorganic fine powder needs to have an average particle diameter of 0.1 to 10 μm, and preferably 0.5 to 5 μm. If the average particle size of the inorganic fine powder is larger than 10 μ, even if the particles are evenly adhered to the film surface, particles are difficult to be formed on the film surface due to winding pressure in the process of winding and storing the film in a roll shape. This is not preferable, because small irregularities are formed on the surface), smoothness is lost, and transparency is reduced. On the other hand, if the average particle size is smaller than 0.1 μ, the inorganic fine powder is buried in the water-soluble polymer, and the anti-adhesion effect is reduced, or the particles are aggregated into larger particles, which is not preferable.

The amount of the inorganic fine powder deposited is the unit surface of the film.
0.01g / m per product²~ 1 g / m ², Especially 0.05
~ 0.5 g / m²It is good to Adhesion amount is 0.01g
/ M ²Smaller amount has almost no anti-adhesion effect, and
1 g / m²The higher the amount, the finer the powder will be on the surface of the film.
There is a risk that the film will be deposited in pieces and the smoothness of the film surface will be impaired.
is there.

Further, a small amount of conventionally known anti-adhesive agents such as starch and talc may be mixed with the inorganic fine powder to be adhered to the surface of the film, and the mixing ratio in this case is adhesive. Can be appropriately selected according to the degree of. Next, as the water-soluble polymer, polyvinyl alcohol, polyethylene oxide, sodium polyacrylate, water-soluble celluloses such as carboxymethyl cellulose, hydroxyethyl cellulose, alkyl cellulose, or viscose, soluble starches such as carboxymethyl starch, diester. Examples include aldehyde starch.

Even if these water-soluble polymers are used alone,
You may use 2 or more types together. The weight ratio of the inorganic fine powder to the water-soluble polymer is preferably 1:10 to 10: 1, more preferably 3: 7 to 7/3. If it is more than 10: 1, the outflow of deposits due to rainwater is poor, and
If it is less than 1 to 10, the workability improving effect is not observed. Further, if necessary, a small amount of an acid or alkali, an antifoaming agent, a surfactant, an antistatic agent, an antioxidant, an ultraviolet absorber, a thickener, a pigment, a fungicide, an algae preventative agent may be added to the adhesion mixture. Known additives such as can be mixed.

The mixture is applied to at least one side of the film before the film is wound into a roll. As an adhesion method, an inorganic fine powder and a water-soluble polymer are dispersed in water to prepare an aqueous dispersion, which is then rotated,
A method is used in which droplets are made into droplets by an ordinary spraying device such as a fluid nozzle, adhered to a film, and dried by natural drying or a forced drying method using hot air or infrared irradiation. An organic solvent such as alcohol may be added to the aqueous dispersion for improving the repellency of the vinyl chloride resin film. The average particle size of the sprayed droplets needs to be 10 to 100 μm. When the average particle diameter of the droplets is smaller than 10 μ, it is difficult to adhere to the film surface due to elastic repulsion to the film. On the other hand, if it is larger than 100 μ, even with the same amount of adhesion, it locally adheres to the film surface and uneven adhesion occurs after drying and the transparency is restored after running water, but the initial appearance is inferior, which is not preferable.

After the mixture is adhered to 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. Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited to the following examples unless the gist thereof is exceeded.

[0015]

【Example】

Examples 1 to 8 and Comparative Examples 1 to 6 (1) Production of soft vinyl chloride resin film Polyvinyl chloride (degree of polymerization = 1300) 100 parts by weight Di-2-ethylhexyl phthalate 50 parts by weight Tricresyl phosphate 5 parts by weight Parts 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 Benzophenone-based UV absorber 0.2 parts by weight Resin raw materials listed above The resin additives were weighed, stirred and mixed with a super mixer for 10 minutes, then kneaded on a roll heated to 165 ° C., and a transparent soft material having a width of 100 cm and a thickness of 0.05 mm was formed by an L-type calender device. A vinyl chloride resin film was manufactured.

Further, the film after coming out of the calender roll is brought into contact with a cooling roll to bring the film to 40 ° C.
Cooled to: Next, as shown in Table 1, various inorganic fine powders and water-soluble polymers were weighed in predetermined amounts, water was added, and the mixture was stirred and mixed so that the total concentration of the inorganic fine powders and the water-soluble polymers was 10% by weight. The water dispersion was prepared so that the two-fluid nozzle (manufactured by Ikeuchi Co., Ltd., AKI JE) was formed on one side of the film.
T) is used to adjust the air pressure and the liquid back pressure so that the particle diameter of the droplet becomes a predetermined size, and the adhesion amount after drying is 0.3.
It was sprinkled to give ~ 0.7 g. (The particle size of the liquid droplets is a laser light scattering type particle size distribution measuring device (LDSA-1300 manufactured by Tohnichi Computer Applications Co., Ltd.)
It was measured in A). ) After spraying, it was naturally dried or forcedly dried in a drying zone, and wound into a roll with a surface winder. (However, it was not sprayed in Comparative Example 6.) By winding the film, fine powder adhered to both surfaces of the film. As the water-soluble polymer, polyvinyl alcohol (Nippon Synthetic Chemical Industry Co., Ltd.)
(Made by Gohsenol 172SS, hereinafter abbreviated as 172SS)
Alternatively, methyl cellulose (manufactured by Shin-Etsu Chemical Co., Ltd., Metroze SM-15, hereinafter abbreviated as SM-15) was used.

(2) Evaluation of tackiness, surface smoothness and transparency after running water The 14 kinds of films wound in a roll in (1) were kept in a roll at a temperature of 40 ° C. and a relative humidity of 90%.
After being left for 2 weeks in the above atmosphere, the tackiness, surface smoothness and transparency after outflow of the film were evaluated by the following methods, and the results are shown in Table 1.

Evaluation of Adhesiveness A film of 50 cm square is cut out from the roll-shaped material, folded into four and stacked, and a load of 30 kg is applied on the film.
The film was left standing for 24 hours in an atmosphere kept at 0 ° C., a load was applied, and 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 △: Slight tackiness ×: Remarkably tackiness

After the tackiness was evaluated by evaluating the surface smoothness, the film was washed with water and the surface of the film was observed with the naked eye. The evaluation results shown in Table 1 have the following meanings. ○: The surface is extremely smooth. △: Some irregularities are observed on the surface. ×: Substantial irregularities are observed on the surface.

Evaluation of Transparency after Running Water A film of 50 cm square was cut out from the roll-shaped material, and the film was spread on the ceiling of a water tank containing hot water having a tilt angle of 30 ° shown in FIG. The aquarium was closed. The whole water tank was put in a temperature-controlled room, hot water was kept at 50 ° C., and temperature of the temperature-controlled room (outside air temperature of the water tank) was kept at 20 ° C. for 6 hours.

Next, the film was turned upside down and the water tank was closed again, and the film was treated under the same conditions for 6 hours. After completion of the treatment, the film was removed and dried, and the transparency of the film was visually evaluated. The evaluation results shown in Table 1 have the following meanings. O: Good transparency B: Slightly inferior X: Inferior in transparency

[0022]

[Table 1]

[0023]

EFFECT OF THE INVENTION According to the present invention, the anti-adhesive fine powder can be uniformly adhered to the film during the film production process, and the extremely soft and stable anti-adhesive agricultural vinyl chloride system for agricultural use A resin film is obtained.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a water tank used in evaluation of transparency after running water in Examples.

[Explanation of symbols]

 1 Water tank 2 Water surface position of hot water 3 Untreated film spread on the roof 4 Evaluation sample film spread on the roof

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C09D 5/00 PPT 6904-4J 129/04 PFM 6904-4J 171/02 PLQ 9167-4J

Claims (1)

[Claims] 1. At the time of manufacturing a soft vinyl chloride resin film, before winding the film into a roll, at least one surface of the film is mixed with an inorganic fine powder having an average particle size of 0.1 to 10 μm at room temperature. A soft vinyl chloride resin for agricultural use, characterized in that an aqueous dispersion containing a tacky water-soluble polymer is sprayed as droplets having an average particle size of 10 to 100 μm to be adhered and then dried. Film manufacturing method.