JPS6259142B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Field: The present invention relates to a novel antifogging agent for synthetic resins. BACKGROUND ART Synthetic resin films are currently used in large quantities in various fields; for example, films of polyvinylidene chloride, polypropylene, polybutylene, etc. are widely used in greenhouses for growing plants for agriculture or horticulture, or for food packaging. . The surface of these synthetic resins is originally hydrophobic, and depending on the temperature difference between the inside and outside, the surface of the synthetic resin becomes cloudy or forms water droplets, which reduces the light transmittance through the synthetic resin. When used in agriculture or horticulture, this can cause problems such as poor growth of plants, and water droplets adhering to the film can fall onto plants, damaging them or causing diseases. exists. In addition, when used for food packaging, there are problems such as cloudiness making it difficult to see inside or making the contents appear less fresh. Problems to be Solved by the Invention: In order to solve this problem, a film or film kneaded with a surfactant such as glycerin fatty acid ester, sorbitan fatty acid ester, etc. as an antifogging agent for the purpose of providing a water droplet prevention effect. sheets are commonly used. However, these antifogging agents have the disadvantage that they are limited in terms of compatibility with synthetic resins, have problems in sustainability, and cannot withstand long-term use. Means for Solving the Problems: The present inventors have conducted extensive research in order to eliminate such drawbacks, and as a result, they have come to provide the present invention. That is, (a) one or two esters of a polyhydric alcohol having 2 to 20 carbon atoms (hereinafter referred to as polyhydric alcohol) and a fatty acid having 8 to 22 carbon atoms (hereinafter referred to as fatty acid);
More than species and (b) General formula () [In the formula, X is

[Formula] p is a number from 0 to 50, q is a number from 1 to 100, R is H, an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 1 to 22 carbon atoms, a phenyl group, or a phenyl group having 1 to 22 carbon atoms. Alkyl group-containing alkylphenyl group, Y is H or CH ₃ ,
Each is shown below. ] The compound represented by (hereinafter referred to as the compound of the general formula ()) is obtained by polymerizing a mixture of the ester: the compound of the general formula () = 95-50:5-50 on a weight basis. This antifogging agent for synthetic resins is characterized by containing a polymer composition as a main component. Examples of esters used in the present invention include esters of polyhydric alcohols and fatty acids, and examples of such polyhydric alcohols include ethylene glycol, glycerin, neopentyl glycol,
pentaerythritol, sorbitol, sucrose,
Diglycerin, polyglycerin, dipentaerythritol, propylene glycol, 1,4-butanediol, 1,2-dodecanediol, 1,2
Examples of fatty acids include caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and behenic acid. Methods for producing such esters include conventional methods, such as esterification reaction between the polyhydric alcohol and the fatty acid, or transesterification reaction between the polyhydric alcohol and the lower alkyl ester of the fatty acid. In order to exhibit properties, monosubstituted esters (generally referred to as monoesters) of the polyhydric alcohols are preferred. Examples of the compound of general formula () used in the present invention include esters of saturated or unsaturated alcohols or alkylene oxide adducts of alkylphenols, or alkylene oxide adducts of glycols and acrylic acid or methacrylic acid. It will be done. Examples of such alkylene oxide adducts of saturated or unsaturated alcohols or alkylphenols include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, n-octyl alcohol, 2-ethylhexyl alcohol, and nonyl alcohol. , decyl alcohol, dodecyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, cyclohexyl alcohol, benzyl alcohol, phenol,
For example, ethylene oxide alone or ethylene oxide and propylene oxide added to di-sec-butylphenol, octylphenol, n-butylphenol, t-butylphenol, nonylphenol, or cresol may be used. Furthermore, examples of alkylene oxide adducts of glycols include those obtained by adding ethylene oxide alone or ethylene oxide and propylene oxide to ethylene glycol or propylene glycol. The amount of alkylene oxide added is 1 to 100 mol, preferably 6 to 20 mol, in the case of ethylene oxide, and 0 to 50 mol, preferably 0 to 50 mol, in the case of propylene oxide, per 1 mol of saturated or unsaturated alcohol, alkylphenol, or glycol. is 0 to 10 moles. The method for producing the compound of general formula () includes, for example, an esterification reaction between the alkylene oxide adduct and the acrylic acid or methacrylic acid, or a reaction between the alkylene oxide adduct and the lower alkyl ester of acrylic acid or methacrylic acid. Examples include transesterification reactions. Next, the polymer composition used in the present invention is as follows:
Examples include those obtained by mixing the ester and the compound of the general formula () and then polymerizing the mixture. The mixing ratio (by weight) of these esters and the compound of general formula () is preferably ester:compound of general formula ()=95-50:5-50. Such a polymer composition may be prepared without a solvent or in a solvent such as water, methyl alcohol, ethyl alcohol, dioxane, etc., in the presence of a polymerization initiator such as a redox catalyst or a radical polymerization catalyst, if necessary.
It can be obtained by polymerizing a mixture using benzene, toluene, etc. and removing the solvent after polymerization. The antifogging agent for synthetic resins according to the present invention contains the above polymer composition as an essential component. Examples of the synthetic resin include polyvinyl chloride, polyvinylidene chloride, polypropylene, polyethylene, ethylene-α-olefin copolymer, and polyethylene-vinycetate copolymer. The amount of antifogging agent added to the synthetic resin is arbitrary, but preferably 0.05 to 100 parts by weight of the synthetic resin.
The amount is 50 parts by weight, more preferably 0.1 to 10 parts by weight. When the antifogging agent of the present invention is added to a synthetic resin to form a film, known methods such as melt extrusion, calendering, inflation, etc. may be used. Effects of the Invention: The antifogging agent of the present invention has characteristics such as excellent compatibility with various synthetic resins and exhibiting excellent effects over a long period of time. Examples: The present invention will be explained below with reference to production examples and examples, but the present invention is not limited only to these examples. Production example 1 Stearic acid monoglyceride 80g, Put 20g and 100g of toluene into a 300ml four-necked flask, mix and stir. Add 0.5g of benzoyl peroxide and gradually warm up. A slight exotherm is observed at 60℃. Heat to 70°C and stir at the same temperature for 3 hours. Next, the pressure inside the system is reduced, and the final vacuum level is 10 Torr and 120℃.
Toluene is distilled out until no more toluene is recognized. Next, the absence of double bonds in the product was confirmed by NMR spectrum, and a polymer composition having a melting point of 45°C was obtained. Production example 2 Stearic acid monoglyceride 50g, lauric acid sorbitan ester 20g, Put 30g and 200g of water into a 1000ml four-necked container, mix and stir to emulsify and disperse, then add to ammonium persulfate.
Dissolve 0.4g in 10g of water and add. Then gradually warm it up. Fever is observed at around 70℃. Heat to 80°C and stir at the same temperature for 3 hours. The bromine number of the product was measured and found to be 0, confirming the absence of double bonds, that is, the completion of polymerization. 500 ml of benzene are then added to the product and it is dehydrated azeotropically. After dehydration, benzene is distilled off. Finally, the process was carried out at a vacuum degree of 10 Torr and below 100° C. until no benzene was distilled out, and a paste-like polymer composition was obtained. Example A predetermined amount of a synthetic resin and an antifogging agent were added to an extruder, and a 50μ film was obtained by an inflation method. The anti-fog properties of these films were tested by outdoor exposure.
Observations were made in a constant temperature bath test at 10°C and a water whitening test. The results are shown in Table 1.

[Table] Outdoor exposure test: Pour 50ml of water into a 250ml beaker, cover the top of the beaker with a film, and seal. Next, the film was exposed outdoors, and the degree of water adhesion to the film was evaluated as follows. ◎; No water droplets attached, transparent 〇; Large water droplets attached, transparent △; Significant water droplets attached, slightly opaque ×; Minute water droplets attached, opaque - Thermostat test at -10; Conducted according to the outdoor exposure test. However, instead of being exposed to the outdoors -10
It was placed in a constant temperature bath at ℃. Whitening test: The film was cut into 10 cm x 10 cm squares and placed in a water solution.The state of the film was evaluated after 2 weeks. ○: Transparent, △: Slightly cloudy, ×: Whitening.

Claims (1)

[Scope of Claims] 1 (a) One or more esters of a polyhydric alcohol having 2 to 20 carbon atoms and a fatty acid having 8 to 22 carbon atoms, and (b) General formula () [wherein, an alkyl phenyl group containing an alkyl group having 1 to 22 carbon atoms, Y is H or CH ₃ ,
Each is shown below. ] A polymer composition obtained by polymerizing a mixture obtained by mixing the compound represented by the above in a ratio of ester: compound represented by the general formula () = 95 to 50: 5 to 50 on a weight basis. An antifogging agent for synthetic resins, characterized by containing it as an ingredient.