JPH11152383A - Agricultural vinyl chloride-based resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agricultural vinyl chloride-based resin film, the surface of which is free of molds and which is well molded through calendar forming process. SOLUTION: The agricultural vinyl chloride-based resin film is prepared by blending a copolymer of a glycidyl ester of (meth)acrylic acid and an alkyl ester of (meth)acrylic acid. Here, the above-mentioned alkyl ester of (meth) acrylic acid is preferably methyl methacrylate. The agricultural vinyl chloride- based resin film is prepared by blending a copolymer of a glycidyl ester of (meth)acrylic acid and an alkyl ester of (meth)acrylic acid with a vinyl chloride resin and then forming a film through calendar forming process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an agricultural vinyl chloride resin film and a method for producing the same.

[0002]

2. Description of the Related Art In order to grow crops efficiently, a method of cultivating them in a house or in a tunnel has been actively adopted. As a material for covering the house or the tunnel, a vinyl chloride resin film excellent in weather resistance, transparency and heat retention is frequently used. This vinyl chloride resin film for agriculture is manufactured by extruding or calendering a vinyl chloride resin. By the way, the vinyl chloride resin has an irregular structure in its structure, and causes degradation due to heat, light, oxygen, etc. mainly in the dehydrochlorination reaction at the time of molding and further use, and This produces coloring. Therefore, a metal soap-based stabilizer, an organic tin-based stabilizer, a lead-based stabilizer, and a non-metal-based stabilizer such as an epoxy compound, phosphite, and β-diketone are blended as stabilizers during processing. In particular, an epoxy compound is frequently used as a so-called stabilizing aid in combination with a metal soap or the like.

As the epoxy compound, an epoxidized vegetable oil such as epoxidized soybean oil or an epoxy resin such as bisphenol A glycidyl ether has been used. However, when epoxidized vegetable oil such as epoxidized soybean oil is used as a stabilizer, the moldability at the time of calendering is good, but when the obtained film is stretched and used as a covering material for a house or a tunnel, There is a problem that mold is easily generated on the surface, and if mold is generated, it has an adverse effect such as a decrease in light transmittance. In addition, when an epoxy resin such as bisphenol A glycidyl ether is used, the epoxy resin adheres to the surface of the calender by plating out of the vinyl chloride resin compound during calendering processing, although the above mold does not occur. There is a problem that the roll releasability is reduced, the appearance of the film is deteriorated, and the calendering process cannot be performed smoothly.

[0004]

In view of the above circumstances, an agricultural vinyl chloride resin film is an epoxy-based resin film which does not generate mold on the film surface when stretched and does not plate out during calendering. There is a need for a stabilizing aid. The present invention has been made to meet this need.

[0005]

That is, the present invention provides:
A vinyl chloride resin film for agricultural use, characterized by blending a copolymer of glycidyl (meth) acrylate and alkyl (meth) acrylate. As the above-mentioned alkyl (meth) acrylate, methyl methacrylate is preferred. Further, the present invention provides an agricultural chloride comprising mixing a vinyl chloride resin with a copolymer of glycidyl (meth) acrylate and alkyl (meth) acrylate and then calendering the film. This is a method for producing a vinyl resin film.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The vinyl chloride resin in the present invention is a copolymer containing polyvinyl chloride as a main component in addition to polyvinyl chloride. As monomers that can be copolymerized with vinyl chloride, vinylidene chloride, ethylene, propylene, acrylonitrile, vinyl acetate, maleic acid, acrylic acid, alkyl acrylate, methacrylic acid,
And methacrylic acid alkyl esters.

The copolymer of glycidyl (meth) acrylate and alkyl (meth) acrylate used in the present invention can be produced by various known methods. For example, it may be produced by copolymerizing (meth) acrylic acid glycidyl ester monomer and (meth) acrylic acid alkyl ester monomer, or by polymerizing (meth) acrylic acid alkyl ester monomer to form (meth)
It may be produced by making an alkyl acrylate polymer, reacting the polymer with epichlorohydrin, and converting some of the alkyl esters of the polymer to glycidyl esters.

The above-mentioned glycidyl (meth) acrylate is produced by reacting (meth) acrylic acid or (meth) acrylate or alkyl (meth) acrylate with epichlorohydrin in a molar ratio of 1: 1. .
(Meth) acrylic acid is acrylic acid or methacrylic acid. The (meth) acrylate is sodium acrylate, potassium acrylate, sodium methacrylate, potassium methacrylate, or the like. Examples of the alkyl (meth) acrylate include methyl acrylate, ethyl acrylate, propyl acrylate, methyl methacrylate, ethyl methacrylate, and propyl methacrylate.

As the alkyl (meth) acrylate to be copolymerized with the glycidyl (meth) acrylate, those mentioned above are used, and methyl methacrylate is preferred. The glycidyl (meth) acrylate and the alkyl (meth) acrylate are copolymerized by addition polymerization of a vinyl group. The polymerization ratio is not particularly limited, and may be determined in consideration of the oxirane oxygen content in the copolymer as described later. The content of glycidyl (meth) acrylate in the copolymer is preferably 20 to 80% by weight, more preferably 50 to 65%. When it is desired to increase the oxirane oxygen content, the polymerization rate of glycidyl (meth) acrylate is increased. In addition, in the case where the polymer is reacted with epichlorohydrin to the alkyl (meth) acrylate monomer polymer, it is preferable to use polymethyl methacrylate for the polymer, and the reaction ratio of epichlorohydrin is the same as above. And the oxirane oxygen content in the copolymer. This copolymer used in the present invention is commercially available, for example, under the trade name Falpac 50M (Nippon Oil & Fats Co., Ltd.).

The copolymer used in the present invention has an epoxy group in a side chain, which supplements hydrogen chloride generated by decomposition of a vinyl chloride resin, and performs a substitution reaction with unstable chlorine, so that it serves as a stabilizing aid. Works. Therefore, the heat resistance and the weather resistance of the vinyl chloride resin can be greatly improved by using together with a main stabilizer such as a metal soap.

[0011] The calendering of vinyl chloride resin is performed at a high temperature of 160 to 200 ° C. When an epoxy compound is added to the vinyl chloride resin to impart heat resistance,
This heat resistance is closely related to the oxirane oxygen content of the epoxy compound. In the calendering process, the oxirane oxygen content of the epoxy compound is considered to be 0.050 g per 100 g of polyvinyl chloride for heat resistance in the case of polyvinyl chloride. However, if the conventional epoxy resin is blended in an amount such that the oxirane oxygen content becomes 0.050 g or more per 100 g of polyvinyl chloride, plate-out occurs.

On the other hand, when the above-mentioned copolymer in the present invention is used, plate-out does not occur even if the oxirane oxygen content is reduced to about 0.180 g per 100 g of polyvinyl chloride. Therefore, according to the present invention, heat resistance can be sufficiently improved without occurrence of plate-out. However, considering the initial coloring of the compound at the time of processing, it is not preferable to mix the compound so that the oxirane oxygen content becomes 0.200 g or more per 100 g of polyvinyl chloride. Therefore, the copolymer of the present invention is blended with the vinyl chloride resin in such an amount that the oxirane oxygen content per 0.05 g of polyvinyl chloride is 0.05 to 0.200 g.

The above-mentioned copolymer can also be used in combination with a conventional epoxy resin, and the combined use can improve plate-out when a conventional epoxy resin is blended. Therefore, in consideration of cost, etc.,
It may be used in combination with a conventional epoxy resin as long as it does not hinder calendering. If necessary, a plasticizer, a stabilizer, an ultraviolet absorber, an antioxidant, a light stabilizer, an antifogging agent, an inorganic filler, an antiadhesive, a lubricant, and the like can be added. In the present invention, the film is formed by a reverse L-shaped calender roll, an L-shaped calender roll,
It can be carried out by a conventional method using a normal calendar roll such as a Z-type calendar roll.

[0014]

EXAMPLES AND COMPARATIVE EXAMPLES Example 1 100 parts by weight of polyvinyl chloride (degree of polymerization 1300), DO
P45 parts by weight, TCP 5 parts by weight, Ba-Zn-based liquid stabilizer 2 parts by weight, Ba-Zn-based powder stabilizer 1 part by weight, sorbitan monopalmirate (anti-fogging agent) 2 parts by weight, methylene bisamide 0.3 parts by weight And 3 parts by weight of Falpac 50M were preliminarily mixed with a blender, then passed through a Banbury mixer, mixing roll, and warming roll, then formed into a film with an inverted L-type calender roll, cooled with a cooling drum and wound up to a thickness. A 100 μm agricultural polyvinyl chloride film was produced. Even if the operation was performed for a long time, the epoxy resin did not plate out on the roll, and the work was successfully performed. Further, the obtained film did not generate mold when used for stretching.

Test Example [Plate-out test] Polyvinyl chloride (degree of polymerization 130
0) 100 parts by weight, DOP 45 parts by weight, TCP 5 parts by weight, Ba-Zn-based liquid stabilizer 2 parts by weight, Ba-Zn-based powder stabilizer 1 part by weight, sorbitan monopalmirate (anti-fogging agent) 2 parts by weight, methylene A sample was prepared by mixing a predetermined amount of 0.3 parts by weight of bisamide and each of the epoxy compounds shown in Table 1. Sample Nos. 1 to 7 are examples using the epoxy resin of the present invention, and Sample Nos. 7 to 14 are examples using other epoxy compounds. Each sample was premixed with a blender and kneaded with a mixing roll. This kneading was performed at a roll temperature of 185 ° C. and a roll gap of 0.3 mm. Then, for each sample, the roll surface during kneading was observed, and the time required for the epoxy compound to plate out on the roll surface was examined. The results are shown in Table 1. The evaluation criteria are as follows. ◎: No plate-out occurred for 60 minutes ○: Plate-out occurred for 30 to 60 minutes ×: Plate-out occurred within 30 minutes

[Static Heat Resistance Test] Each sample shown in Table 1 was kneaded at a roll temperature of 165 ° C. for 5 minutes, and then formed into a sheet having a thickness of 1 mm. 170 ° C
And the time required for the sample film to turn black was examined. The results are shown in Table 1. Also,
The evaluation criteria are as follows. A: Blackening time 210 minutes or more. Does not discolor during calendar work. ：: Blackening time 120 to 210 minutes. The color may change depending on the conditions at the time of calendar work. X: Blackening time less than 120 minutes. Color changes during calendar work.

[Mold Generation Test] Each of the samples shown in Table 1 was kneaded at a roll temperature of 165 ° C. for 5 minutes, and then a 0.1 mm thick film was formed at 185 ° C. using a calender roll. This film was spread from November 1, 1996 to July 10, 1995 in Narita City, Chiba Prefecture, and examined for the occurrence of mold. The results are shown in Table 1. ○ indicates that no mold was generated, and X indicates that mold was generated.

[0018]

[Table 1]

In Table 1, Falpac 50M (manufactured by NOF CORPORATION) is a trade name of a copolymer of glycidyl methacrylate and methyl methacrylate, Epicoat.
(Manufactured by Daicel Corporation) is a trade name of a polymer of bisphenol A and epichlorohydrin, and Sumiepoxy (manufactured by Sumitomo Chemical Co., Ltd.) is a trade name of a polymer of bisphenol A and epichlorohydrin. As shown in Table 1, when a copolymer of glycidyl methacrylate and methyl methacrylate (Falpac 50M) was used as a stabilizing aid, the ratio was higher than when another epoxy compound was used as a stabilizing aid. However, it can be seen that the plate-out property, the heat resistance, and the mold-producing property are all excellent and are excellent.

[0020]

According to the present invention, when a conventional vinyl chloride resin film for agricultural use containing an epoxidized vegetable oil such as epoxidized soybean oil as a stabilizing aid is used as a coating material for a house or a tunnel, the surface of the resin film becomes moldy. The mold is liable to occur, and this mold causes adverse effects such as causing disease on cultivated plants. However, in the present invention, the above-mentioned copolymer is used, so that such an obstacle can be prevented. In addition, when an epoxy resin such as bisphenol A glycidyl ether is used as a stabilizing aid, the above-mentioned mold does not occur. Although there was a problem that the calendering process requiring delicate control of the gap and the like could not be performed smoothly, in the present invention, such a problem can be reduced because the above-described copolymer is used. Further, in the present invention, since the polyvinyl chloride resin containing the above copolymer has remarkably improved heat resistance, there is no coloring at the time of calender molding.

Claims (3)

[Claims] An agricultural vinyl chloride resin film containing a copolymer of glycidyl (meth) acrylate and alkyl (meth) acrylate. 2. The agricultural vinyl chloride resin film according to claim 1, wherein the alkyl (meth) acrylate is methyl methacrylate. 3. An agricultural chloride comprising blending a vinyl chloride resin with a copolymer of glycidyl (meth) acrylate and alkyl (meth) acrylate, and then forming a film by calendering. A method for producing a vinyl resin film.