JPS6231737B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to agricultural vinyl chloride resin films, and more specifically to undesirable deterioration phenomena such as discoloration and embrittlement caused by stretching outdoors, particularly so-called "deterioration on crosspieces". This invention relates to an agricultural vinyl chloride resin film that has improved weather resistance so that it is less likely to cause this. In recent years, farmers cultivating useful plants have widely adopted methods of promoting or suppressing cultivation of useful plants in greenhouses or tunnels for the purpose of improving profitability. As materials for covering the house or tunnel, polyethylene film, ethylene-vinyl acetate copolymer film, vinyl chloride resin film, etc. are used. Among them, vinyl chloride resin film has the following characteristics compared to other synthetic resin films:
It has the best overall light transmittance, heat retention, mechanical strength, durability, workability, economic efficiency, etc.
Widely used. However, synthetic resin films used to cover greenhouses or tunnels, including vinyl chloride resin films, can become susceptible to sunlight, especially ultraviolet rays, after a year has passed since they were used for coating. This causes changes over time such as deterioration and loss of flexibility. Furthermore, recent labor-saving agricultural techniques have begun to require coating materials to withstand even more severe conditions than in the past. In order to eliminate the above-mentioned drawbacks, the vinyl chloride resin film used for coating houses or tunnels contains, for example, organic tin stabilizers, metal soap stabilizers, lead stabilizers, organic barium stabilizers, etc. Additives such as antioxidants and ultraviolet absorbers are often added to improve resistance to light, heat, oxidation, etc. However, to date, no substance has been found that has a noticeable effect when added in small amounts. Some of the above additives can improve the weather resistance of the film if added in large amounts, but on the other hand, they reduce workability during film formation and ease of handling after film formation. This causes a problem in that the transparency of the film deteriorates. For example, if a large amount of metal soap stabilizer is added, plate-out (additives precipitate on the roll surface when forming into a film by calendar forming) may occur during film forming, resulting in reduced film forming work efficiency. This significantly reduces the appearance and transparency of the film. Epoxy compounds and organic phosphite esters also have the effect of improving the weather resistance of the film to some extent, but there is a limit to the amount that they can be blended. If large amounts are added, bleed-out (various additives blowing out on the film surface) may occur.
The films adhere to each other, and the adhered films become difficult to peel off (separability deteriorates). Furthermore, organic phosphoric acid esters are also effective in improving the weather resistance of the film when added in small amounts, but when added in excess of a certain amount, tricresyl phosphate conversely lowers the weather resistance and at the same time lowers the heat resistance. By the way, when constructing a house or a tunnel, a method is adopted in which a frame is made from aggregate prepared from wood, metal, synthetic resin, etc., and the frame is covered with a synthetic resin film and fixed at the necessary points. . Deterioration of synthetic resin film occurs in areas that are in contact with fixing devices such as frames that fix the film (referred to as "on-piece deterioration"), and deterioration in areas that are not in contact with fixing devices (referred to as "flat surface deterioration"). This is more remarkable than the deterioration of parts. Therefore, the lifespan of the film is
It is significantly affected by the presence or absence of "deterioration on the pier".
Even if the "flat surface deterioration" is small, if the "board deterioration" is large, the film is likely to be torn, causing practical problems. Recently, there has been a strong tendency to increase the size of greenhouses for greenhouse cultivation, and in the case of large greenhouses, metal materials are used as aggregates. In the case of aggregate made of metal materials, the
There is a problem that "deterioration on the pier" is likely to occur. Under such circumstances, the present inventor has discovered that when used outdoors as a covering material for a house or tunnel,
As a result of intensive studies, we have completed the present invention with the aim of providing an agricultural vinyl chloride resin film that is not only less prone to "deterioration on flat surfaces" but also less prone to "deterioration on crosspieces". It has been reached. Therefore, the gist of the present invention is to add (A) tricylenyl phosphate, and (B) a compound of the general formula [In formula (), R ₁ represents an alkyl group having 4 to 18 carbon atoms. ], or [In the formula], R ₂ is an alkyl group having 5 to 13 carbon atoms, R ₃ is an alkyl group having 1 to 18 carbon atoms, and X is hydrogen, halogen, alkyl group, alkoxy group, aryloxy group, aralkyloxy Agricultural vinyl chloride type with excellent weather resistance characterized by being formed into a film by blending one type or a combination of two or more of the compounds represented by the following: The present invention will be described in detail below. In the present invention, the vinyl chloride resin includes not only polyvinyl chloride but also copolymers containing vinyl chloride as a main component. Vinyl chloride Monomers that can be copolymerized with vinylidene chloride, ethylene, propylene, acrylonitrile,
Examples include maleic acid, itaconic acid, acrylic acid, methacrylic acid, vinyl acetate, etc., but the examples are not limited to these. The vinyl chloride resin may be manufactured by any conventionally known manufacturing method, such as suspension polymerization, emulsion polymerization, emulsion-suspension polymerization, solution polymerization, and bulk polymerization. . In the present invention, in the vinyl chloride resin,
Trixylenyl phosphate is blended as component (A). Trixylenyl phosphate can be produced from a phenol fraction containing xylenol as a main component. Xylenol has six types of isomers depending on the position of the two methyl groups, and when producing tricylenyl phosphate, each isomer component is not fractionated but reacted with phosphorus oxychloride. let Therefore, tricylenyl phosphate is
It is obtained as a mixture of compounds containing xylenyl groups with substituents at different positions. According to the inventor's experiments, among the xylenyl group isomers of tricylenyl phosphate, 2,
When the proportion of compounds containing 3-xylenyl groups and 3,5-xylenyl groups (total of both) is 30% by weight or more based on the total amount of the isomer mixture, the flexibility of agricultural vinyl chloride resin films can be improved for a long period of time. It turned out that it was possible to maintain it. If the amount of component (A) added to the vinyl chloride resin is too small, the intended weather resistance of the film will be improved,
In particular, it cannot be expected to improve "on-board deterioration," and on the other hand, if there is too much, there will be problems with plate-out during film production, and the resulting film will have too high stickiness.
Problems such as a decrease in heat resistance occur. A preferred blending ratio is in the range of 1 to 10 parts by weight per 100 parts by weight of the resin. In the present invention, in the vinyl chloride resin,
In addition to blending component (A), component (B) is also blended. Among the components (B), the compounds represented by the general formula () include 2-(2'-hydroxy-5'-tertiary-butylphenyl)benzotriazole,
2-(2'-hydroxy-5'-tetramethylbutylphenyl)benzotriazole, 2-(2'-hydroxy-5'-amyl phenyl)benzotriazole, 2-(2'-hydroxy-5'-n-hexyl phenyl) ) benzotriazole, 2-(2'-hydroxy-5'-cyclohexylphenyl)benzotriazole, and the like. However, the examples of these compounds do not limit the present invention. Among component (B), compounds represented by the general formula () include the following compounds. However, the examples of these compounds do not limit the present invention. Compound 1 Compound 2 Compound 3 Compound 4 Compound 5 Compound 6 Compound 7 Compound 8 The component (B) to be blended into the vinyl chloride resin is one or more compounds represented by the general formula () or (). When one type is used, either one of the compounds represented by formula () or () may be used; when two or more types are used, one type of each of the compounds represented by formula () and () may be used. It is preferable to If the amount of component (B) added to the vinyl chloride resin is too small, the flexibility of the film will be significantly reduced during long-term outdoor expansion, while if it is too large, there will be a large amount of bleed-out when the film is used, which may cause damage to the film. Transparency is also reduced. If the amount of bleed-out is large, the surface of the film becomes easily stained and the transparency deteriorates more quickly, which is not preferable. The preferred blending ratio is 0.3 parts per 100 parts by weight of vinyl chloride resin.
-3 parts by weight. In the present invention, the above-mentioned
Although it is essential to mix component (A) and component (B),
Furthermore, the general formula [In formula (), m is an integer from 1 to 5, and x is 0, provided that m+x<6.
An integer of ~4, R ₄ is a halogen, an alkyl group or alkoxy group having 1 to 12 carbon atoms, R ₅ and R ₆ are an alkoxy group having 1 to 24 carbon atoms, or an alkyl group having 4 to 24 carbon atoms. The ones chosen from, y and z are
Each represents an integer from 1 to 4, provided that at least one ortho position of each phenyl ring has no substituent. ] By blending component (C) represented by the following, it is possible to improve the weather resistance of the film, maintain the ultraviolet shielding effect, and further prevent discoloration and decrease in flexibility. Examples of compounds represented by the general formula () that can be used as component (C) include the following compounds. However, the exemplification of these compounds is not intended to limit the invention. Bis(4-methoxyphenyl) phthalate, bis(4-t-butylphenyl) phthalate, bis(2-ethoxy-4-t-butylphenyl) isophthalate, bis[4(1,1,3,3-tetramethylbutyl) ) phenyl] phthalate, bis(2,4-di-n-amyl phenyl) terephthalate, bis(4-isodecylphenyl) isophthalate, bis(2-nonylphenyl) isophthalate, bis(3-nonylphenyl) isophthalate, bis (4-nonylphenyl)isophthalate, bis[3(1,1-dimethyloctoxyl)
phenyl]isophthalate, bis(2,3,4,
5-tetramethoxyphenyl) terephthalate,
Bis(3-octoxyphenyl) terephthalate, bis(2,4-d-n-hexyl phenyl)
Terephthalate, bis(2-methoxy-4-t-
butylphenyl) isophthalate, bis(3-isopropoxyphenyl) isophthalate, bis(4-t-butylphenyl) 3,4-dichlorophthalate, bis(4-t-butylphenyl) 4-
Octadekoxyisophthalate, bis[4(1,
1,3,3-tetramethylbutyl)phenyl]terephthalate, bis(4-t-butylphenyl)
4-bromoisophthalate, bis(4-tetracodylphenyl)isophthalate, bis[4(2-
ethylhexyl) phenyl] 3,4,5,6-tetrachlorophthalate, bis(4-octadecyl phenyl) isophthalate, bis(2,3,4-
tridecyl phenyl) isophthalate, bis(4
-t-butylphenyl) 4,6-di-t-butyl isophthalate, bis(3-butoxyphenyl)
6-octadecyl isophthalate, bis(4-ethoxyphenyl) 6-dodecyl isophthalate,
Bis[3(1-ethyl-1-methylpentyl)phenyl]6-hexadecyloxyisophthalate, [4(1,1,3,3-tetramethylbutyl)phenyl](2,3,4,5-tetra methylphenyl) isophthalate, (4-t-butylphenyl)(4-methylphenyl)isophthalate, tris(4-t-butylphenyl) trimellitate, tris[4(1,1,3,3-tetramethylbutyl)phenyl] trimellitate, tris(3-nonylphenyl) trimezate, tris(3,4-diisoamyl phenyl) trimezate, tris(4-hexadecylphenyl) trimellitate, tris(4-octadecylphenyl)
trimesate, tris(3-isobutoxyphenyl) trimesate, tris(4-t-butylphenyl) hemimerisate, tris[4(1,1,
3,3-tetramethylbutyl)phenyl]hemimellitate, tris(3-isopropyloxyphenyl) trimesate, tris(2-n-butylphenyl) trimesate, (4-t-butylphenyl)bis(3-isopropoxyphenyl) trimesate . (C) The general formula for the component is Compounds represented by are preferred. The amount of component (C) added to the vinyl chloride resin is 10 parts by weight or less, particularly preferably in the range of 0.3 to 10 parts by weight, per 100 parts by weight of the vinyl chloride resin. The agricultural vinyl chloride resin according to the present invention has the above-mentioned
Component (A), component (B), and if necessary component (C) are added and blended, but other additives such as plasticizers, lubricants, antifogging agents, etc. are added as necessary before film formation. agent,
Heat stabilizers, pigments, dyes, etc. can be added. Examples of plasticizers that can be used include phthalic acid derivatives such as di-n-octyl phthalate, di-2-ethylhexyl phthalate, dibenzyl phthalate, diisodecyl phthalate, didodecyl phthalate, and diundecyl phthalate; and diisooctyl isophthalate. Isophthalic acid derivative; G-n
- Adipic acid derivatives such as butyl adipate and dioctyl adipate; maleic acid derivatives such as di-n-butyl maleate; citric acid derivatives such as tri-n-butyl citrate; itaconic acid derivatives such as monobutyl itaconate; butyl oleate, etc. Oleic acid derivatives; ricinoleic acid derivatives such as glycerin monocitrate; others such as tricresyl phosphate, epoxidized soybean oil, and epoxy resin plasticizers. In order to blend the above-mentioned (A) component, (B) component, and if necessary (C) component into the vinyl chloride resin, it is preferable to use a soft blend. For soft formulation, use vinyl chloride resin
30 to 60 parts by weight of plasticizer may be added to 100 parts by weight. Examples of lubricants or heat stabilizers that can be used include polyethylene wax, liquid paraffin, stearic acid, zinc stearate, fatty alcohols,
Examples include calcium stearate, barium stearate, barium ricinoleate, dibutyltin laurate, dibutyltin malate, and the like. Antistatic agents or antifogging agents that can be used include:
There is no restriction as long as it has been used conventionally in agricultural coating films. Specific examples include polyethylene glycol alkyl esters such as polyethylene glycol monostearate and polyethylene glycol dibehenate; sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate and polyoxyethylene sorbitan monooleate; polyoxyethylene lauryl ether polyoxyethylene fatty acid ethers such as; glycerin fatty acid ethers such as glycerin behenyl ether; fatty acid alkylolamine condensates such as diethanolamine stearate; these may be used alone or in combination of two or more. Good too. Resin additives other than these plasticizers are used in an amount of 5 parts by weight or less based on 100 parts by weight of the vinyl chloride resin. The above (A) component is added to the base vinyl chloride resin,
Component (B), component (C), and other resin additives are blended using conventional blending and mixing techniques, such as a ribbon blender, Banbury mixer, super mixer, and other blenders and mixers. This is possible due to the technology that In order to manufacture the agricultural vinyl chloride resin film according to the present invention, ordinary film manufacturing methods such as calendar molding, extrusion molding, inflation molding, etc. can be appropriately employed. If the thickness of the agricultural vinyl chloride resin film according to the present invention is too thin, the strength will be insufficient, so it is not preferable.On the other hand, if it is too thick, it will be difficult to form the film into a film, and the subsequent handling (cutting the film into a house shape) will result in insufficient thickness. This may cause inconvenience during work such as joining work to a house, work to extend it to a house, etc.), so it is better to set it in the range of 0.03 to 0.2 mm. The agricultural vinyl chloride resin film according to the present invention has the following characteristics, and its agricultural utility value is extremely large. (1) Even when the agricultural vinyl chloride resin film according to the present invention is used outdoors for a long period of time, there is little bleed-out of additives, and therefore, appearance deterioration such as a decrease in film transparency is unlikely to occur. (2) The agricultural vinyl chloride resin film according to the present invention does not suffer from "plane part deterioration" even after being used outdoors for a long time.
There is little ``deterioration on the crosspiece'', and it can be used for a long period of time. (3) The agricultural vinyl chloride resin film according to the present invention can further improve weather resistance when the three components (A), (B) and (C) are used together. (4) Agricultural vinyl chloride resin film mixed with a UV absorber to block UV rays of 370 to 390 nm or less is a film that is harmful to useful plants such as filamentous fungi (molds), rod-shaped bacteria, and arthropods. Although it is known to be able to suppress animal activity, its ability to block ultraviolet light often deteriorates over time. In the agricultural vinyl chloride resin film according to the present invention, component (B) absorbs ultraviolet rays, and when used in combination with component (A) and also component (C), the film absorbs ultraviolet rays. The shielding properties remain particularly remarkable even after long-term use (2 years). Hereinafter, the present invention will be explained in detail based on examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Examples 1 to 7, Comparative Examples 1 to 9 Polyvinyl chloride (=1400)...100 parts by weight Dioctyl phthalate...45 Epoxy resin (product name "EP-828")
...1〃 Barium-zinc-based composite liquid stabilizer
...1.5 〃 Barium stearate ...0.2 〃 Zinc stearate ...0.4 〃 Sorbitan monostearate ...1.5 parts by weight of a resin composition was prepared, and component (A), component (B),
(C) Component and other components (mainly for comparative examples)
were blended in the cases shown in Table 1. Each formulation was stirred and mixed using a super mixer for 10 minutes, and then kneaded on a roll mill heated to 165°C to form a film with a thickness of 0.1 mm. The following evaluation tests were conducted on each film, and the results are shown in Table 2. (b) Weather resistance was evaluated as follows.
A large amount of film was exposed on a window frame-shaped exposure test stand facing south and tilted at 45 degrees to the plane, and some of the film was removed periodically.
evaluated. "Flat surface deterioration" refers to the appearance (observation with the naked eye) of the exposed part of the film where both the front and back sides are free and not held down by the crosspiece, and the residual elongation rate (as determined by a tensile test in accordance with JISK-6732). The results are shown below. "Deterioration on the pier" means that on the back side of the exposed film,
The film was fixed on a crosspiece by contacting a galvanized iron plate, and the appearance and residual elongation of this part of the film were evaluated.The results are shown below. The evaluation results were displayed as follows. 〇…There is no change in appearance and the remaining elongation rate is 80% or more. 〇×…No change in appearance, residual rate of erosion is 60-80%
Those within the range of. △…Appearance changes to yellow, remaining elongation rate is 40-60%
Those within the range of. △×: Discoloration becomes brown, tearing occurs, and the remaining elongation rate is in the range of 20 to 40%. ×: The entire surface has turned brown and has many tears, making it impossible to measure the remaining elongation rate. "Total light transmittance in the ultraviolet region" is measured using a spectrophotometer (manufactured by Hitachi, Ltd., model 323) at wavelengths.
Measurement of transmittance at 370nm, 380nm or 390nm. The film stretched outdoors was subjected to measurements after thoroughly washing the surface with water to remove dirt. Regarding the films of Examples 6 and 7, similar measurements were performed 20 days after the start of stretching, and the results are shown in Table 2. (b) Bleed-out of additives was evaluated as follows. The prepared sample film was left indoors, and after 6 and 12 months, the surface of the film was lightly rubbed with a finger and the extent of the marks on the film surface was observed with the naked eye. The evaluation results were displayed as follows. 〇…There are almost no finger marks. 〇×…Finger marks are left and slight bleed-out is observed. △...Finger marks are left, and bleed-out is clearly observed. △×: There is bleed-out and it is slightly sticky. (c) "Deterioration on crosspiece" test using a stretched greenhouse Four types of films, Example 3, Example 6, Comparative Example 6, and Comparative Example 7, were actually stretched on a greenhouse and the deterioration status of the part that came into contact with the aggregate was measured. observed. The house was 100 m <sup>2</sup> in area, and the frame was as shown in the perspective view in Figure 1. Film was fixed as shown in the figure, and a roof-shaped house extending long from east to west was constructed. While cultivating useful plants in the greenhouse, we observed ``deterioration on the crosspiece'' by observing with the naked eye or touching with our fingers the area A surrounded by the dotted line in Figure 1. The results are shown in Table 3. In FIG. 1, 1 indicates aggregate (made of galvanized steel plate), 2 indicates a film, and 3 indicates a holding spring (made of galvanized steel wire).

【table】

【table】

【table】

[Table] From Tables 1 to 3, the following becomes clear. (1) The agricultural vinyl chloride resin film according to the present invention has excellent weather resistance with little deterioration in both "plane part deterioration" and "deterioration on crosspieces." (2) The agricultural vinyl chloride resin film according to the present invention has less bleed-out of additives, and therefore is less likely to suffer from deterioration in appearance such as a decrease in film transparency. (3) Films using a combination of the three components (A), (B), and (C) (Example 6, Example 7) not only have excellent weather resistance, but also have excellent weather resistance. Compared to films that did not contain component (C) (Comparative Examples 7 and 8), the ultraviolet ray blocking properties remained unchanged over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a state in which a film is stretched and fixed to a house frame. In the figure, 1 is the aggregate, 2 is the film, 3 is the holding spring, and part A is the location where "crosspiece deterioration" is likely to occur.

Claims (1)

[Claims] 1. Vinyl chloride resin, (A) tricylenyl phosphate, and (B) general formula [In formula (), R ₁ represents an alkyl group having 4 to 18 carbon atoms. ], or [In formula (), R ₂ is an alkyl group having 5 to 13 carbon atoms, R ₃ is an alkyl group having 1 to 18 carbon atoms, and X is hydrogen, halogen, alkyl group, alkoxy group, aryloxy group, aralkyloxy group, aryl group. An agricultural vinyl chloride resin film with excellent weather resistance, which is made by blending one or a combination of two or more of the compounds represented by the formula below and molding it into a film. 2. Trixylenyl phosphate, component (A), contains xylenyl groups with substituents at different positions, and is the total tricylenyl phosphate of a compound containing a 2,3 xylenyl group and a 3,5 xylenyl group. The agricultural vinyl chloride resin film according to claim 1, wherein the proportion of phenate is 30% by weight or more. 3 Among the compounds that are component (B), the compound represented by the formula () is 2-(hydroxy-5-tert-butylphenyl)benzotriazole, and the compound represented by the formula () is octyldenbis[4- The agricultural vinyl chloride resin film according to claim 1, which is methyl-6-(benzotriazole)phenol. 4. Agricultural vinyl chloride resin film according to claim 1, which contains 1 to 10 parts by weight of component (A) and 0.3 to 3 parts by weight of component (B) to 100 parts by weight of vinyl chloride resin. . 5. Agricultural vinyl chloride resin according to any one of claims 1 to 4, wherein the base vinyl chloride resin contains 30 to 60 parts by weight of a plasticizer per 100 parts by weight of resin. resin film.