JPS5949934B2 - Weather-resistant vinyl chloride resin film or sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vinyl chloride resin film or sheet, and particularly to an agricultural vinyl chloride film or sheet with excellent weather resistance.

In recent years, with the modernization of agriculture, greenhouse cultivation has become booming, and glass, polyethylene film, polyvinyl chloride film, ethylene-vinyl acetate copolymer film, etc. are used as cover materials for greenhouses. Among them, polyvinyl chloride film is currently the mainstream material for bunkers because it has excellent heat retention, transparency, strength, workability, etc., and is relatively inexpensive.

However, when a general polyvinyl chloride film is used outdoors, it browns and deteriorates within several months. In order to eliminate the above-mentioned drawbacks after forming the film, polyvinyl chloride films used as agricultural materials are treated with, for example, organic tin-based stabilizers, metal stone thread stabilizers, lead-based stabilizers, and organic stabilizers. Various stabilizers against light, heat, and oxidation are added, such as cadmium-based stabilizers, organic barium-based stabilizers, anti-oxidizing agents, and ultraviolet absorbers, but there are some that have a remarkable stabilizing effect when added in small amounts. It is hardly found.Of course, adding a large amount improves weather resistance, but on the other hand, it leads to a decrease in physical properties such as processability and transparency.For example, if a large amount of metal soap stabilizer is added, Plate-out occurs during molding, which impairs the appearance of the molded product, significantly reduces processing efficiency, and reduces transparency.For example, if a large amount of ultraviolet absorber is added, the product will be colored yellow. When used as an agricultural film, the light absorption range is generally in the range of 300 to 400 millimicrons, so it absorbs even the light necessary for plant growth, which may inhibit the growth of some plants. For these reasons, we cannot expect much to improve weather resistance through the combination of the above-mentioned stabilizers.Epoxy compounds and tricresyl fluorescein are currently being used as auxiliary agents to improve weather resistance. Eight (hereinafter abbreviated as TCP) has come to be mainly used, and their use has a temporary effect, and TCP in particular has been recognized to have an effect on improving weather resistance.However, there are limits to the amount of these added. For example, epoxy compounds cause bleed (a phenomenon in which a liquid substance is discharged onto the surface of a molded product), cause films to stick to each other and reduce peelability, increase physical embrittlement, and cause TCP problems. However, if polyvinyl chloride film is added beyond a certain limit, it will cause a decrease in weather resistance and even cause a decrease in heat resistance.Furthermore, when conventional polyvinyl chloride film is used outdoors for agricultural purposes, the weather resistance will decrease. Although it is said that the usage limit is usually one year, or two years at best, there is currently a demand for films that can be used for a long period of two years or more in order to save the trouble of replacing the film in greenhouse cultivation. ing.

In view of these circumstances, the present inventors conducted intensive research to obtain an agricultural film with excellent weather resistance, and as a result, they first added trixyl phosphate (hereinafter referred to as TXP) to the raw material vinyl chloride resin for polyvinyl chloride film molding. It was discovered that a vinyl chloride resin composition for agricultural film molding with significantly superior weather resistance could be obtained by blending the following compounds (described below), and the patent application (Japanese Patent Publication No. 50-35542, Japanese Patent Publication No. 51-3740) was made.
However, as a result of further continuation of this research, dixylenyl monocresyl phosphite (hereinafter abbreviated as DXP) and monoxylenyl dicresyl phosphite (hereinafter abbreviated as DXP) were developed. (hereinafter abbreviated as MXP)
The present invention was completed after discovering that, like TXP, it is effective in improving the weather resistance of vinyl chloride resin films.

The present invention includes a vinyl chloride resin, 30 to 80 parts by weight of a plasticizer per 100 parts by weight of the resin, and 0.02X to 0.3X.
(X represents parts by weight of plasticizer.

) Agricultural vinyl chloride resin film or sheet (hereinafter referred to as film) formed by molding a resin composition containing one or two of DXP or MXP (hereinafter referred to as film) into a film or sheet form. It is. To further explain the present invention, the raw material vinyl chloride resin in the present invention includes:
Polyvinyl chloride, copolymers of vinyl chloride and other monomers such as vinyl acetate, ethylene, propylene, alkyl vinyl ethers, acrylic esters, methacrylic esters, esters of vinyl carboxylates, acrylonitrile, etc.; polyvinyl chloride or the above polychlorides; Examples include polymer blends of vinyl copolymers and chlorine-containing polymers or copolymers such as chlorinated polyethylene, chlorinated polypropylene, and chlorinated polyisoprene. The present invention is not affected in any way by the type and degree of polymerization of the above resin. As the plasticizer in the present invention, it is possible to use plasticizers that are usually blended with vinyl chloride resins, such as di-2-ethylhexyl phthalate (abbreviated as DOP), diisodecyl phthalate (abbreviated as DIDP), etc.
), butylbenzyl phthalate (abbreviation: BBP), but as an aliphatic dibasic acid ester, dioctyl adipate (
Phthalate ester plasticizers such as dioctyl sebacate (abbreviation DOS), glycol ester plasticizers such as diethylene glycol dibenzoate (abbreviation DEDB), fatty acid ester plasticizers such as butyl oleate (abbreviation BO) Examples of other plasticizers include trioctyl trimellitate (abbreviated as TOT), chlorinated paraffin, and alkylbenzene.

These plasticizers may be used alone or in combination. The amount of plasticizer blended is preferably about 30 to 80 parts by weight per 100 parts by weight of the raw material vinyl chloride thread resin. If the amount of plasticizer is less than 30 parts by weight, the flexibility is sufficient to be used as an agricultural film when stretched. It is not possible to obtain a film having . Furthermore, if the amount of plasticizer exceeds 80 parts by weight, the film becomes too soft and the mechanical strength decreases.
The film itself becomes sticky, which is not preferable. In the xylenyl group of DXP and MXP in the present invention, the two methyl groups on the benzene ring may be attached to any position relative to each other, and the cresyl group may also be attached to any position of the methyl group on the benzene ring. The blending amount may be 0.02X with respect to the blending amount of the plasticizer.
- 0.3X part by weight (X represents the blended part by weight of the plasticizer as described above.

(the same applies hereinafter) is an essential requirement. That is, DXP, . If the blending amount of MXP is less than 0.02X parts by weight, the desired improvement in weather resistance cannot be expected; on the other hand, if it exceeds 0.3X parts by weight, other physical properties during and after film molding may be affected. For example, it is undesirable because processability and heat resistance decrease, and the weather resistance effect gradually decreases, and the most preferable blending amount for improving weather resistance is 0. It is around IX parts by weight. In order to obtain the weather-resistant polyvinyl chloride resin film of the present invention, a commonly known processing machine such as a Rippon blender, a Banbury mixer, or a calender roll is used to obtain the polychloride resin film having a polymerization degree of 1400. To the vinyl resin, a necessary amount of plasticizer and DXP in the above range per 100 parts by weight of the resin) M
A film containing XP and other stabilizing aids can be easily obtained using a calender roll or an extruder.

In this case, the effects of other stabilizers, such as heat-resistant stabilizers, which are added at the same time, are not impaired.

It goes without saying that in the film of the present invention, weather resistance improvers other than TXP, other stabilizers, and additive auxiliaries may be used in combination. The vinyl chloride resin film of the present invention is made by blending a specific amount of plasticizer and DXPsMXP, and as shown in the examples below, the weather resistance of this agricultural vinyl chloride film is higher than that of conventional vinyl chloride resins. It is of an extremely high quality that has never been seen on film.

For example, 100 parts by weight of vinyl chloride resin, plasticizer DOP4
A film obtained from a resin composition containing 5 parts by weight of DXP with parts by weight of O, 2 parts by weight of a Cd-Ba composite stabilizer, and 3 parts by weight of an epoxy compound exhibits weather resistance for more than 2 years,
Compared to conventional agricultural vinyl films, which exhibit a browning phenomenon in about one year, the weather resistance of the vinyl chloride resin film of the present invention is found to be far superior. Next, the usefulness of the polyvinyl chloride resin film of the present invention will be explained with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

In the description, "parts" means "parts by weight."

Example 1 Polyvinyl chloride resin (degree of polymerization 1400) 10
0 parts, DOPlDXP and 3 parts of epoxy resin (trade name: EP-828) in the proportions shown in Table 1 below and Cd-B.
Two parts of a-type composite stabilizer were blended and kneaded for 7 minutes in a test calender at 160°C to produce a film sample with a thickness of 0.1 m/m and a sheet with a thickness of 0.5 m/m.

The 0.5 m/m sheet was subjected to a heat resistance test using a gear oven at 180°C, and the weather resistance of the 0.1 m/m thick film was determined by visual observation by exposing it outdoors in a closed house facing south at 45 degrees. The results shown in Table 1 were obtained.

As is clear from Table 1 above, 0.02X to 0.3X (X
is the number of parts by weight of plasticizer) The film containing PHR (7) DXP exhibits extremely superior weather resistance compared to the comparative example.

For example, DOP4OPHR, . This shows that when DXP5PHR is blended, a product with weather resistance of 2 years or more can be obtained.

Considering that commercially available agricultural vinyl films turn brown in 12 months, it becomes clear how excellent the weather resistance improvement effect of DXP is. When the blending amount of DXP is less than 0.02XPHR, weather resistance is not improved much.

If the amount of DXP exceeds 0.3XPHR, the weather resistance effect will gradually decrease and adverse effects such as increased initial coloring and shortened heat resistance time will occur in the heat resistance test, which is not preferable. The most desirable DX from Table 1
The amount of P added is 0. It can be seen that it is around IXPHR. Example 2 DOP and . DOA) MXP and 3 parts of epoxidized soybean oil (trade name: 0-130) and Ba-Z
Two parts of an n-based composite stabilizer was blended and kneaded for 7 minutes in a test calender at 160°C to produce a film sample with a thickness of 0.1 m/m and a sheet with a thickness of 0.5 m/m.

The 0.5 m/m thick sheet was subjected to a heat resistance test by gear opening at 180°C, and the 0.1 m/m thick film was evaluated for weather resistance using the method described in Example 1. Table 2
The results shown are obtained.

As is clear from Table 2 above, in the case of Example 2, the amount of MXP blended was 0.0 for the amount of plasticizer used, X-70PHR.
2X~0.3XPHR i.e. 1.4~21PHR(!)M
Films containing XP exhibit superior weather resistance compared to comparable films.

On the other hand, when the amount of MXP deviates from 0.02X to 0.3XPHR, almost no improvement in weather resistance is observed.

From Table 2, the blending amount of MXP is 0.02X~0.3XPHR
It turns out that it is preferably around 0.1XPHR. In Example 2, DOP and DOA are used together as plasticizers, and a Ba-Zn composite stabilizer is used as a stabilizer, and the effect of MXP on improving weather resistance is clear. As described above, when the agricultural vinyl chloride resin film of the present invention is used as a cover material for greenhouse cultivation, it can be used for a long period of two years or more,
It has great utility in the agricultural field.

Claims (1)

[Claims] 1. 30 parts per 100 parts by weight of the vinyl chloride resin.
~80 parts by weight of a plasticizer and 0.02X to 0.3X (X represents parts by weight of the plasticizer) of dixylenyl monocresyl phosphite or monoxylenyl dicresyl phosphite. A weather-resistant agricultural vinyl chloride resin film or sheet formed by molding a resin composition containing one or two types into a film or sheet form.