JPH02296849A - Agricultural vinyl chloride resin film - Google Patents

Abstract

PURPOSE:To obtain a film excellent in low-temperature antifogging properties and antimisting properties and retentivity of antifogging properties by using a vinyl chloride resin comprising a plasticizer, a fluorine compound and a specified alkylene oxide adduct. CONSTITUTION:An agricultural film prepared from a vinyl chloride resin composition comprising 100 pts.wt. vinyl chloride resin, 40-60 pts.wt. plasticizer, 0.01-1.0 pt.wt. fluorine compound and 0.2-3.0 pts.wt. sorbitan mono(di)stearate/alkylene oxide adduct and/or a sorbitan mono(di)palmitate/alkylene oxide adduct and has a residual area rate after shrinkage >=64% at 160 deg.C. As the fluorine compound, one having a fluorinated group and an alkylene oxide group and/or a hydroxyl group in the molecule can be used, and it has an MW of 500-10000 and decreases the surface tension of water.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an agricultural vinyl chloride resin film used as a covering material for agricultural tunnels, simple greenhouses, etc.

[Conventional technology]

Conventional agricultural vinyl chloride resin films are used in tunnels, simple greenhouses, etc. to prevent condensation that forms on the film's inner surface from blocking sunlight from passing through the film. It is common practice to impart so-called antifogging properties by causing the fog to flow down. Specifically, since agricultural films are often used especially in winter, we add alkylene oxide to sorbitan fatty acid ester as an antifogging agent to improve antifogging performance at low temperatures. Also known are those to which a fluorine-containing compound is added as an anti-fog agent to prevent fog from forming inside the greenhouse.

[The problem that the invention attempts to solve! 1i) However, the agricultural vinyl chloride resin film provided with low-temperature anti-fog properties and anti-fog properties as described above has a problem in that its anti-fog durability is reduced.

The present invention solves these problems, and aims to provide an agricultural vinyl chloride resin film that not only has excellent low-temperature anti-fogging properties and anti-fog properties, but also has excellent long-lasting heat protection properties. purpose.

[Means for Solving the Problems] The present invention is based on the following problems:
0 to 60 parts by weight, 0.01 to 1.0 parts by weight of a fluorine-containing compound, and 0.2 parts of an alkylene oxide adduct of sorbitan mono(di)stearate and/or an alkylene oxide adduct of sorbitan mono(di)palmitate. ~3
．． "A vinyl chloride resin film for agricultural use, which is a vinyl chloride resin film containing 0 parts by weight, and which has a shrinkage area residual ratio of 65% or more at 160°C." That is.

[Effect]

The agricultural vinyl chloride resin film of the present invention is made by adding a specific antifogging agent, and by specifying the shrinkage area retention ratio of the film at 160°C to a value or more.
In addition to having excellent low-temperature antifogging properties like conventional products, it also has excellent antifogging durability that conventional products did not have. It is presumed that the above-mentioned effects unique to the present invention are caused by the reasons described below.

In other words, in general, it can be said that a certain amount of antifogging agent must be present on the film surface as a necessary element for a film to have antifogging properties, and furthermore, this antifogging property must last for a long period of time. In order to achieve this, it is necessary to transfer an appropriate amount of antifogging agent from the inside of the film to the surface side so that a certain amount of antifogging agent is always present on the surface of the film.

Therefore, it is known that the migration property of the above-mentioned antifogging agent is greatly affected by the compatibility between the film base resin and the antifogging agent used. Although the alkylene oxide adduct of sorbitan fatty acid ester used as It is considered to be inferior to

On the other hand, it can be assumed that the following reasons are further responsible for the remarkable improvement in antifogging durability of the product of the present invention. Jfp, the strain (internal strain) inherent in the film due to the molecular orientation state inside the film that occurs during the film forming process is involved in the compatibility of the antifogging agent with the resin and the ability to migrate to the film surface. Therefore, in the present invention, by specifying the shrinkage area residual ratio of the film at 160°C and reducing the internal strain above a certain amount, it is possible to improve the substantial compatibility between the heat protectant and the resin. As a result, the antifogging agent present inside the film gradually migrates to the surface over a long period of time, resulting in particularly excellent antifogging durability. It will be done.

The present invention will be explained in detail below.

The vinyl chloride resin used in the present invention includes vinyl chloride homopolymer resin, vinyl chloride and ethylene vinyl acetate,
Examples include copolymer resins with copolymerizable monomers such as vinyl ether and maleic acid ester, and mixtures thereof.

As the plasticizer, those normally used for vinyl chloride can be used, such as phthalate ester plasticizers, phosphate ester plasticizers, adipate ester plasticizers, and epoxy group-containing phthalate ester plasticizers. , epoxidized soybean oil, epoxy resin, etc., and these can be used singly or in combination.
Use a mixture of more than one species. If the amount of this plasticizer added to 100 parts by weight of vinyl chloride resin is less than 40 parts by weight,
The film has a high degree of curing and poor cold resistance in cold winter conditions, making it unsuitable. On the other hand, if it exceeds 60 parts by weight, the film becomes too soft and sticky, making it unsuitable for the present invention.

As the fluorine-containing compound, those having a fluorine-containing group, an alkylene oxide group and/or a hydroxyl group in the molecule can be used, and this compound has a molecular weight of 500 to 10,000 and has the property of lowering the surface tension of water. This is what we are doing. Examples of the fluorine-containing groups include perfluoroalkyl groups, perfluoroalkoxy groups, polyfluoroalkyl groups, perfluoroalkenyl groups, polyfluoroalkenyl groups, and perfluoroalkylene groups. Examples of alkylene oxide groups include ethylene oxide groups (including polyethylene oxide groups), propylene oxide groups (including polypropylene oxide groups), etc.
For example, JP-A-57-192445, JP-A-59-8
No. 0468, JP-A-59-93739, JP-A-61-
133244, JP-A-61-152745, JP-A-62-158756, and JP-A-64-6046. Specific examples of such fluorine-containing compounds include the following.

(a) Csf'+tCtHaO(C!HnO)sc
Hz(b) C1@El□CHxCH(Oll)CH
xO(CsHbO) +*C11s(c) C,. P
□CH Snow C8 (OH) CHgO (CIH40) 5H (
d) C*P+wCHxCH(OH)CHtO(Cs
HbO) + J(e) CaFttCHsCH(OCO
CHi)CHgO(CsHiO)scHs(f) C
aF+, SOIN(CmHs)(CJnO)IH@Ca
F+sCON(Calls)(CgllmO)sH(h
) CsFtvSolN(CHmCII(OH)CI
lmOtl) m(1) HCP, C5Ft*CHt
O(CJnO) +J(j) CsF, OCsFiC
lltCHmSCH(COOH)CHtCOO(CtH
aO)+J(g) CsF? OC%F1. CH*CH*
SCH (Cl *C00H) COO (C, H40)
t sCIIgOCOC+Jss CF (CF mountain C00 (CJH, O) country CJ+*(
r) CF(CFi)tc(CFs)CJ+e If the amount of the fluorine-containing dicompound added to the vinyl chloride resin is other than the above 0.01 to 1.0 parts by weight, it will provide excellent fog protection to the film. It becomes difficult to impart durability and weather resistance.

The alkylene oxide adduct in the present invention is sorbitan mono(di)stearate or sorbitan mono(di)stearate.
It is obtained by adding alkylene oxide such as ethylene oxide and/or propylene oxide to palminate. The amount of alkylene oxide added is preferably 0.5 to 5 mol, more preferably 0.8 to 3 mol,
When the amount added exceeds 5 moles, the compatibility with the resin decreases, and the weather resistance as a coating material tends to decrease.

The amount of the above adduct added to 111 parts by weight of vinyl chloride tea plant is 0.2 to 3.0 parts by weight, preferably 0.5 to 1 part by weight.
．． If the amount added is 0.2 parts by weight, the low-temperature heat resistance will be poor, and if it exceeds 3.0 parts by weight, the weather resistance of the film will be poor and surface bloom will increase, making it unsuitable. .

In the present invention, together with the above alkylene oxide adduct,
Other antifogging agents that may be used in combination include sorbitan fatty acid ester, sorbitol fatty acid ester, diglycerin fatty acid ester, glycerin fatty acid ester, sorbitan fatty acid dibasic acid ester,
Sorbitol fat 1FJal/dibasic acid ester, diglycerin fatty acid/dibasic acid ester, glycerin fatty acid/
Examples include esters of polyhydric alcohols and fatty acids such as dibasic acid esters, esters of polyhydric alcohols and fatty acids and dibasic acids, and one or more of these can be used.

The film of the present invention is obtained by molding a resin composition having the above-mentioned formulation into a film (sheet) shape, and any conventional molding method can be used for the molding method, such as calendaring. Molding methods, T-die extrusion methods, inflation silane molding methods, etc. can be employed. Further, the thickness of the film of the present invention is preferably about 0.05 to 0.2 nna.

The residual shrinkage area of the film in the present invention is determined by the following procedure.

■Problem of removing limbs: First, the following marked line is added to the surface of the outermost layer of the film wound into a roll after forming, while still in the rolled state. The gauge line consists of two straight lines, both of which have a length of 20 CI, the ``horizontal gauge line'' along the width direction of the film and the ``vertical gauge line'' along the film length direction, and the center is centered on these two lines. The points are drawn at right angles. Three of these two-line sets I are placed in the width direction of the film (i.e., one in the center of the film and 30 in each from the left and right ends of the film.
Attach 2 pieces at 2 locations within cm.

Next, the film is unwound and cut into pieces of about 25 cm x 25 cm so as to surround each of the two marked lines, and these pieces are used as test pieces.

(2) Dish measurement method 1 The test piece is heated in an oven at 160'C for 10 minutes, then cooled to room temperature, and then the lengths of each of the horizontal and vertical marked lines on the 3 Mi marked line are measured. This method of actually measuring the length of the marked line is difficult because the marked line itself often becomes curved due to heat shrinkage.
(shortest distance).

The final measurement result (Noshi!, L+ in the formula below) is the gauge line whose minimum value is the product of the length of the vertical gauge line and the length of the horizontal gauge line in the three sets of actually measured gauge lines. (In other words, the actual measured values of the length of the vertical gauge line and the length of the horizontal gauge line of the set of gauge lines with the largest degree of contraction).

Finally, the measurement results are applied to the following formula to calculate the shrinkage area remaining ratio.

Shrinkage area remaining ratio (%) In the formula, L: Length of vertical and horizontal gauge line (both 20 cm) L! : Length of vertical gauge line after heat treatment; : Length of gauge line in horizontal direction after heat treatment.

The above-mentioned area residual ratio in the present invention is 65% or more, preferably 70%, and if it is less than 65%, there are problems such as not being able to obtain good anti-fog durability.

In addition, in the present invention, stabilizers, ultraviolet absorbers, lubricants, fillers, infrared absorbers, colorants, light stabilizers, algaecides, fungicides, epoxy group-containing compounds, and acrylic resin processing are used as necessary. Modifiers and the like can be added. Further, if necessary, another synthetic resin film can be applied to one side of the film. Examples of the above-mentioned films include acrylic resin films, fluororesin films, olefin resin films, etc., and ordinary film forming methods can be applied to apply the film, such as coating methods, laminating methods, melt film forming methods, etc. etc. can be adopted.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 4, Comparative Examples 1 to 6 Resin compositions A to D consisting of the formulations shown in Table 1 were appropriately selected and used, and after being melted, they were supplied to a calender roll at 180 ° C. and the compositions shown in Table 2 were used. Calendar molding was carried out according to any one of molding conditions a to c, cooled to room temperature with a cooling roll, and then wound around a paper tube to obtain a film with a thickness of 0.1 m. Each of the above films was obtained using the combinations of resin compositions and molding conditions shown in Table 3.

The shrinkage area remaining after heat treatment at 160"cS for 10 minutes was calculated for each of the obtained films, and the low-temperature antifogging properties and antifogging durability of each film were determined using the following method. Shown in the table.

"Low-temperature anti-fogging properties 1 Each film was spread out in a vehicle inspection pipe house with a width of 3.5 m and a length of 20 m (September), and the surface condition of the film was observed in December of the same year, and evaluated based on the following criteria.

○=There are no streaks in the flow of water droplets, and the flow of water droplets is also good.

B: Some streaks are observed.

Δ:t! Many L streaks were observed, and the streak marks were not clean.

×: There are many flow lines and there are places where water droplets directly fall to the ground.

r Anti-fog durability 1 In the greenhouse used for the above low-temperature anti-fog observation, after 5 months (February of the following year), 8 months (May), and 12 months (September)
After 14 months (November), the surface condition of the film was observed and evaluated based on the following criteria.

○: Good flow throughout the entire surface with no water droplets attached.

B: Some water droplets are observed.

Δ: A large number of water droplets are observed.

X: Water droplets are attached to the entire surface.

Table 1 [Effects of the Invention] As explained above, the agricultural film of the present invention has the above-mentioned composition and has a shrinkage area retention rate of 65% or more at 160°C, so it has low-temperature antifogging properties. Not only does it have excellent anti-fog properties, but it also has excellent anti-fog durability. Therefore, the product of the present invention makes it possible to prevent various problems caused by water droplets during crop cultivation over a long period of time, which is of great practical benefit.

Claims (1)

[Claims] 40 parts of plasticizer per 100 parts by weight of vinyl chloride resin
~60 parts by weight, 0.01 to 1.0 parts by weight of a fluorine-containing compound, and 0.2 to 0.2 parts of an alkylene oxide adduct of sorbitan mono(di)stearate and/or an alkylene oxide adduct of sorbitan mono(di)palmitate. 3.0
A vinyl chloride resin film containing part by weight, and the shrinkage area residual ratio at 160°C of the film is 6.
An agricultural vinyl chloride resin film characterized by having a polyvinyl chloride content of 5% or more.