JPH05295278A - Anti-fogging synthetic resin film for agriculture - Google Patents

Abstract

PURPOSE:To give a agricultural synthetic resin film anti-fogging properties at the initial stage of a low temperature and excellent in durability at high temperature. CONSTITUTION:To 1mol erythritol, 1 to 5mol, preferably 1 to 4mol EO (ethylene oxide) and/or 0.1 to 3mol, preferably 0.1 to 1mol PO (propylene oxide) is added. The order of addition of EO and PO is arbitrary or EO and PO may be simultaneously added using a mixtufe of EQ and PO. With 1mol the resultant erythritol- alkylene oxide addition product, 1 to 3mol fatty acid selected from among lauric acid, myristic acid, palmitic acid, stearic acid, hydroxystearic acid and behenic acid is reacted to obtain an ester. This reaction is carried out by the conventional esterification method, i.e., by a dehydration reaction in the presence of an alkali catalyst or an acid catalyst at 150 to 200 deg.C in an atmosphere of an inert gas. This anti-fogging agent is blended in an amount of 0.2 to 5.0 pts.wt., preferably 1 to 2.5 pts.wt. based on 100 pts.wt. synthetic resin, provided that a film-forming thermoplastic synthetic resin is exemplified as the synthetic resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-fogging synthetic resin film, and more particularly to an anti-fogging synthetic resin film which has excellent durability at high temperature and excellent anti-fogging property immediately after film spreading.

[0002]

2. Description of the Related Art Conventionally, there has been a method for cultivating vegetables in a greenhouse made of a synthetic resin film such as polyvinyl chloride, polyethylene, or a copolymer of ethylene and vinyl acetate, which enables cultivation even in low temperatures. Has been taken. In this case, since the synthetic resin film used needs to always transmit sunlight, a method of kneading an antifogging agent in advance is used to prevent the occurrence of clouding due to water on the surface of the synthetic resin film. Examples of the antifogging agent include higher fatty acid esters such as polyethylene glycol, glycerin, sorbitan, and sorbitol, and ethylene oxide (hereinafter referred to as EO) in addition to these higher fatty acid esters.
Or) propylene oxide (hereinafter referred to as PO) has been used as a nonionic surfactant.

[0003]

However, from the viewpoint of economic efficiency in recent years, as the number of cases in which such synthetic resin film is used for a long period of one year or more is increasing from the conventional less than one year, especially at high temperature in summer. The lack of sustainability in Japan has come to be pointed out. On the contrary, it has been pointed out that the improved high temperature durability has a poor initial effect and low temperature effect.

[0004]

Means for Solving the Problems As a result of earnest research to solve the problems of the synthetic resin film for agriculture, the present inventors have found that 1 mol of erythritol followed by 1-5 mol of EO and / or 0 mol of PO. A compound obtained by adding 1 to 3 moles and then reacting 1 to 3 moles of a saturated fatty acid having 12 to 22 carbon atoms as a novel antifogging agent is added to 0.2 to 5.0 parts by weight per 100 parts by weight of the synthetic resin. By forming a film by kneading and blending, it is found that the problem of the high temperature durability of the conventional agricultural synthetic resin film can be solved, and that the effect of the low temperature initial stage can be obtained to be a good agricultural synthetic resin film. It has come. The antifogging agent of the present invention (hereinafter referred to as an antifogging agent) is obtained as follows.

First, 1 to 5 moles of EO is added to 1 mole of erythritol.
Mol preferably 1 to 4 mol, and / or PO 0.1 to
3 mol, preferably 0.1 to 1 mol is added. EO and PO
Any order of addition may be used, or they may be mixed and added at the same time. 1 mole of the erythritol-alkylene oxide adduct thus obtained is reacted with 1 to 3 moles of a fatty acid selected from lauric acid, myristic acid, palmitic acid, stearic acid, hydroxystearic acid, and behenic acid to obtain an esterified product. From the viewpoint of performance, it is preferable to use 1.1 to 2.2 mol of palmitic acid and stearic acid. The reaction is carried out by a known esterification method, that is, using an alkali catalyst or an acid catalyst in the presence of an inert gas at 150 to
It is obtained by carrying out a dehydration reaction at 200 ° C.

The antifogging agent of the present invention thus obtained is mixed in an amount of 0.2 to 5.0 parts by weight, preferably 1 to 2.5 parts by weight, based on 100 parts by weight of the synthetic resin. Here, the synthetic resin is generally a film-forming thermoplastic synthetic resin.
Specifically, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-acrylic acid ester copolymer,
Vinyl chloride resin such as vinyl chloride-methacrylic acid copolymer; polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid ester Olefin resins such as copolymers and ethylene-butylene copolymers; polyethylene terephthalate, polyamide, polymethylmethacrylate, polyacrylic acid ester, polymethacrylic acid ester, polystyrene, styrene-acrylonitrile copolymer, AB
Examples thereof include S resin, polycarbonate, polyvinyl acetate, fluorine-containing resin and the like, or blends of these polymers.

The antifogging agent of the present invention can be used in combination with known stabilizers and plasticizers in the production of synthetic resin films, and in combination with known fluorine-based or silicone antifog agents in order to obtain antifogging and antifog properties. It is also possible to do so. As the known fluorine-based antifoggant, a conventionally used fluorine-based surfactant or copolymer oligomer can be used, and they may be used alone or in combination of two or more kinds.

Examples include compounds represented by the following general formula.

[0009]

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

Rf SO ₂ NH (C ₂ H ₄ O) nR, Rf
CON (C ₂ H ₄ O) nH (In the formula, Rf represents a linear or branched perfluoroalkyl group, R represents an alkyl group, and n represents a positive number.)

Copolymer Oligomer (I) CF ₃ (CF ₂ ) ₆ (CH ₂ ) ₂ OCOC (CH ₃ ) = CH ₂ and C ₂ H ₅ OCOCH = CH ₂ and HO (C ₂ H ₄ O) ₂ OCO
CH = CH ₂ and a copolymerized oligomer having a molecular weight of about 4000, which is prepared by polymerizing the charged weight ratio of 1.0: 0.1: 1.5.

Copolymer Oligomer (II) CF ₃ (CF ₂ ) ₇ SO ₂ N (CH ₃ ) (CH ₂ ) ₂ OCOC (CH ₃ ).
= CH ₂ and CH ₃ OCOCH = CH ₂ and HO (C ₂ H ₄ O) ₅ OCO
CH = CH ₂ and a copolymerization oligomer having a molecular weight of about 4000 polymerized at a charge weight ratio of 1.0: 1.5: 0.5.

Copolymer Oligomer (III) CF ₃ (CF ₂ ) ₈ CONH (CH ₂ ) ₂ OCOC (CH ₃ ) = CH
₂ and CH ₃ OCOCH = CH ₂ and HO (C ₂ H ₄ O) ₁₀ OCO
CH = CH ₂ and a copolymerization oligomer having a molecular weight of about 2000 polymerized at a charge weight ratio of 1.0: 1.0: 1.0.

Copolymer Oligomer (IV) CF ₃ (CF ₂ ) ₈ (CH ₂ ) ₂ OCOCH = CH ₂ and C ₃ H ₇
OCOCH = CH ₂ and HO (C ₂ H ₄ O) ₃ OCOCH = CH ₂ were polymerized at a charge weight ratio of 1.0: 0.1: 1.0 to a molecular weight of about 200.
0 copolymerized oligomer

Copolymerized oligomer (V) And C₂H_FiveOCOCH = CH₂And HO (C₂H_FourO)₃O
COCH = CH₂ And charge weight ratio 1.0: 0.2: 1.0
Copolymerized oligomer with a molecular weight of about 6000

Further, as a known silicone type antifog agent,
Conventionally used silicone-based surfactants can be used, and may be used alone or in combination of two or more. For example, a compound represented by the following general formula can be mentioned.

[0023]

[0024]

[0025]

(CH ₃ ) ₃ SiO [(CH ₃ ) ₂ SiO] a (C ₂ H ₄ O) n (C ₃ H ₆ O) mR CH ₃ Si {[O (CH ₃ ) ₂ Si] a (OC ₂ H ₄ ) n (OC ₃ H ₆ ) mOR} ₃ (wherein R is an alkyl group or H, a, b and n are 1
The above positive numbers and m are 0 or positive numbers of 1 or more, respectively. )

Next, the present invention will be described with reference to examples. A. Synthesis of antifogging agent (1) of the present invention In an autoclave, industrial erythritol 1 mol 122 g
Then, 1 g of caustic potash was charged, the mixture was heated and dissolved, and then N ₂ substitution was performed.
Then, it took 3 hours to add polyoxyethylene (2 mol)
262 g of polyoxypropylene (1 mol) erythritol
Got The total amount of polyoxyethylene (2 mol) polyoxypropylene (1 mol) erythritol obtained was added to caustic potash 1
g and 1.5 mol of industrial palmitic acid (384 g) were charged, and the temperature was raised to 180 to 200 ° C. while introducing N ₂ gas to carry out esterification for 6 hours. Then, the catalyst is neutralized with phosphoric acid, dehydrated and filtered, and the acid value is 2.0, the hydroxyl value is 270, and the melting point is 4.
1 ° C yellowish brown waxy polyoxyethylene (2 mol)
517 g of polyoxypropylene (1 mol) erythritol palmitate was obtained. This product is subjected to the test described below.

B. Synthesis of Antifog Agents (2) to (10) of the Present Invention Similar to A, the antifog agents (2) to (10) of the present invention were synthesized as shown in Table 1, and the results shown in Table 1 were obtained. It was This product is subjected to the test described below.

[0029]

Note) EO: ethylene oxide, PO:
Propylene oxide * 1: Stearic acid, * 2: Palmitic acid, * 3: Behenic acid, * 4: Hydroxystearic acid, * 5: Unit mgKOH
/ G Anti-fogging agent (8): EO addition after PO addition Anti-fogging agent (9): EO, PO simultaneous addition

C. Comparative antifogging agent Comparative product (1) ... Sorbitan monopalmitate 2.0
Mol EO adduct Comparative product (2) ··· Glycerin monostearate Comparative product (3) ··· Sorbitan monostearate 3.0
Mole EO adduct Comparative product (4) ··· Sorbitan distearate Comparative product (5) ··· Pentaerythritol dipalmitate 2.0 mol EO adduct

D. Preparation of film 100 parts polyvinyl chloride resin, dioctyl phthalate 3
0 part, dioctyl adipate 10 parts, tricresyl phosphate 5 parts, epoxy resin 4 parts, calcium-zinc liquid stabilizer 3 parts, calcium-zinc powder stabilizer 2
Parts and 2.5 parts of antifogging agent were mixed and kneaded with a hot roll at 180 ° C. to prepare a film having a thickness of 0.1 mm, and the antifogging property was evaluated.

E. Evaluation of Antifogging Property The antifogging property of each film was evaluated and the results shown in Table 2 were obtained.

Note Low temperature initial stage: A film is put on the upper inclined box, and the outside temperature is 5 ° C, the water temperature is 15 ° C, and the inclination angle is 10 degrees.
Evaluate the wet state of the film after a lapse of time. High temperature persistence: Film is placed on the upper sloping box, outside temperature: 20
C., water temperature: 50.degree. C., inclination angle of 10 degrees, and evaluation of the wet state of the film after 5 days. Initial outdoors: Wet condition is evaluated 5 hours after the house is stretched. Sustaining outdoors: We evaluated the wet condition on August 1, 1991 and December 1, 1991.

Evaluation Criteria ⊚: One side uniformly wet and transparent ○: Almost one side uniformly wet and transparent ×: Partially transparent part but opaque overall xx: Completely opaque

[0036]

From the results shown in Table 2, it is apparent that the film according to the present invention has good anti-fogging property as an initial effect at low temperature and excellent durability at high temperature.

Claims (1)

[Claims] 1. 1 to 5 mol of ethylene oxide and / or 0.1 mol of propylene oxide per 1 mol of erythritol.
1 to 3 mol of the compound was added, and then 1 to 3 mol of a saturated fatty acid having 12 to 22 carbon atoms was reacted to prepare a synthetic resin 100.
A synthetic resin film having excellent anti-fogging properties, characterized by containing 0.2 to 5.0 parts by weight per part by weight.