JPS58196258A - Anti-fogging agent - Google Patents

Abstract

PURPOSE:To provide an anti-fogging agent composed of a specific polyoxy- alkylene polyglycerol fatty acid ester, having high compatibility with resins, excellent anti-fogging property at low and high temperature, and excellent durability. CONSTITUTION:The objecive anti-fogging agent is prepared by adding an alkylene oxide to a 9-30C polyglycerol in the presence of an alkali metal hydroxide at 120-180 deg.C, esterifying the resultant polyalkylene glycol polyglycerol ether with a 8-22C fatty acid (e.g. lauric acid, stearic acid, etc.) at 160-220 deg.C. The amount of the alkaylene oxide and fattt acid are preferably 1-10mol and 1- 5mol per 1mol of the polyglycerol, respectively. An anti-fogging resin composition can be prepared by adding 0.05-10pts.wt. of the anti-fogging agent to 100pts.wt. of a synthetic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel antifogging agent for synthetic resins used in fields such as agriculture and forestry, agriculture and horticulture, and food packaging. That is, the present invention relates to an antifogging agent for synthetic resins comprising a polyoxyalkylene polyglycerin fatty acid ester obtained by esterifying an alkylene oxide adduct of polyglycerin having 9 to 30 carbon atoms with a fatty acid having 8 to 22 carbon atoms. be.

Thermoplastic synthetic resins, such as polyvinyl chloride.

Vinyl synthetic resin films such as polyvinylidene chloride and ethylene-vinyl acetate copolymer, or olefin synthetic resin films such as polyethylene and polypropylene, are used as covering materials for agricultural or horticultural crops and plant cultivation, or for food packaging. The surfaces of these widely used thermoplastic resins are naturally hydrophobic, so when they are used as covering materials for agricultural or horticultural plants, they may deteriorate due to changes in the temperature, humidity, etc. of the environment. Clouding occurs on the resin surface, which impairs the penetration of sunlight and causes poor germination of seeds and poor growth of seedlings.

Also, for food packaging films, for the same reason, moisture in the air remains on the surface as minute water droplets, causing a cloudy phenomenon, making it impossible to see inside or making the food appear less fresh.

Conventionally, in order to prevent such problems, synthetic resin films have been used as antifogging agents such as polyalkylene glycol high RN fatty acid esters, sorbitan fatty acid esters or their ethylene oxide adducts, glycerin fatty acid esters, polyalkylene glycol high T alcohol ethers, polyalkylene glycol high Nonionic surfactants such as alkylene glycol alkylphenyl ether and propylene glycol fatty acid ester, anionic surfactants such as alkylnaphthalene sulfonates and higher alcohol sulfates, and cationic surfactants such as alkylbi-11dium halides and alkylbi-1)dium sulfates. Films mixed with surfactants and the like are generally used as antifogging synthetic resin films, and there are many patents related to them.

However, these antifogging agents are not heat stable.

The amount used is limited by compatibility with resins, film transparency, etc., and especially when used as a covering material for agricultural and horticultural purposes, it must be used continuously for a long period of time. However, it has drawbacks such as the fact that it does not satisfy the requirements for long-lasting corrosion protection and weather resistance.

As a result of intensive research in order to solve such drawbacks, the present inventors have developed a polyoxyalkylene polyglycerin obtained by esterifying a polyglycerin alkylene oxide adduct having 9 to 30 carbon atoms with a fatty acid having 22 carbon atoms. The present invention was completed based on the discovery that when a fatty acid ester is used as an antifogging agent for synthetic resins, it exhibits an extremely excellent antifogging effect not found in conventional antifogging agents.

That is, the present invention relates to an antifogging agent for synthetic resins comprising a polyoxyalkylene polyglycerin fatty acid ester obtained by esterifying an alkylene oxide adduct of polyglycerin having 9 to 30 carbon atoms with a fatty acid having carbon i of a to 22. be.

The present invention will be explained in detail below.

First, the polyglycerin referred to in the present invention has the following □ structure, and n=1 to 8. It is a viscous liquid with a total carbon number of 9 to 30.

In addition, alkylene oxides include propylene oxide, ethylene oxide, butylene oxide, etc., and have 8 to 8 carbon atoms.
22 fatty acids include Un-octanoic acid, 1SO-octanoic acid, nonanoic acid, decanoic acid, isodecanoic acid, lauric acid, myristic acid, palmitic acid, 1SO-palmitic acid, stearic acid, behenic acid, 12-hydroxystearic acid, and oleic acid. acid, lysyllic acid, linoleic acid, etc.

The antifogging agent according to the present invention can be easily obtained by etherifying or esterifying the above-mentioned components by conventional methods. That is, alkylene oxide is added to polyglycerin at 120 to 180° C. in the presence of an alkali metal hydroxide to obtain polyalkylene glycol polyglycerin ether. Next, this is mixed with higher fatty acids such as those mentioned above and 160 to 22
Esterification at 0°C yields the desired polyoxyalkylene polyglycerol fatty acid ester. When obtaining the antifogging agent according to the present invention, the preferable component ratio due to its properties is as follows:
1 per mole of polyglycerol in alkylene oxide
~10 mol, and polyalkylene glycol 1 in fatty acids
It is 1 to 5 moles per mole.

The polyalkylene glycol polyglycerol fatty acid ester of the present invention has much better antifogging properties at low and high temperatures than conventionally used antifogging agents, and has excellent durability. Furthermore, the synthetic resin film using the antifogging agent of the present invention has good transparency and high compatibility with resin.

The antifogging agent of the present invention can be blended with various synthetic resins such as polyvinyl chloride, polyvinylidene chloride, ethylene-vinyl acetate copolymer, polyethylene, polypropylene, polybutylene, etc. ! ! It is suitable for polyvinyl chloride, polyethylene, and polyvinyl chloride IJ. By adding 0.05 to 10 parts by weight of the antifogging agent of the present invention to 100 parts by weight of the synthetic resin, a good antifogging synthetic resin assembly can be obtained. The antifogging agent of the present invention can contain mm alone or as a mixture with other antifogging agents.

Further, if necessary, other components such as antioxidants, ultraviolet absorbers, pigments, antistatic agents, etc. can be used in combination. Next, synthesis examples and examples are shown, but the present invention is not limited to these examples.

Synthesis example 1 Decaglycerin 760f in a 1t autoclave.

NaOH1,5? N22 at 100-140℃
After replacing the air in the autoclave three times at a rate of 4/m, ethylene oxide 1322 was gradually added to the autoclave at 145°C.

4 k4/cyn to obtain polyethylene glycol decaglycerin ether 820f. Next, polyethylene glycol deca 7 glycerin ether 400 t
, 378 tons of commercially available stearic acid were placed in a four-round flask, and heated at 200 to 210°C for 5 minutes while passing N2 gas.
After heating and stirring for ~5 hours, the mixture was neutralized with phosphoric acid at 100°C and filtered to obtain a product.

Yield 6802 Acid value 3.8 Saponification value 97.5 Hydroxyl value 296.2 Synthesis example 2 Decaglycerin 7609 in a 2t autoclave.

NaOH2? After purging the air in the autoclave three times with N2 at 100-140°C, propylene oxide 58? Gradually add and heat to 145℃, 4
kg/cm2 to obtain polypropylene glycol decaglycerin ether. 88 t of ethylene oxide was added to 818 t of this polypropylene glycol decaglycerin ether in the same manner to obtain polypropylene glycol polyethylene glycol decaglycerin ether. Next, 453 t of polypropylene glycol polyethylene glycol decaglycerin ether and 1 part of commercially available stearin e2aat were charged into a four-loaf flask.
Esterification was performed in the same manner as in Synthesis Example 1 to obtain a product.

Yield 660? Acid value 3.36 Saponification value 78.1 Hydroxyl value 372.9
Melting point: 46.4°C or above Typical synthesis examples are shown, and Table 1 shows several examples of analytical values and melting points of esters synthesized in this way (Synthesis Examples 1 to 4).
1t)).

POP(nl ff in Table 1 indicates the number of moles of propylene oxide added, POK(n) indicates the number of moles of ethylene oxide added.

Table 1 Example 1 The polyalkylene glycol polyglycerol fatty acid esters of Synthesis Examples 1 to 7 in Table 1 were added to vinyl chloride resin in the following formulation to form a film and tested for antifogging properties and weather resistance. .

Anti-fogging test method High temperature anti-fogging... 40°C hot water 100°C
Put C into a 200 CC beaker, cover the mouth of the beaker with a film of the above composition, and secure it with a rubber band. This was placed in a constant temperature bath at the same temperature and the state of water vapor condensation on the film surface was observed and evaluated for a certain period of time. The evaluation is A when it is transparent, and A-
Evaluation was made on a five-point scale of E.

Low-temperature anti-fog property・・・・・・20℃ water 100℃
C was placed in a 200 CC beaker, covered with the above film, and placed in a constant temperature bath at 5° C., and the film surface was evaluated.

The evaluation criteria are the same as for high-temperature antifogging properties.

Weather Resistance Test Method A 100 m+8 x 100 g film was left outdoors so that it was exposed to sunlight vertically, and changes in the surface were observed.

Weather resistance evaluation is as follows.

◎・・・Soft and transparent ○: Soft, slightly opaque Δ...Hard, slightly opaque ×...Hard and opaque The test results are shown in Table 2.

Example 2 The polyalkylene glycol polyglycerin fatty acid esters of Synthesis Examples 8 to 10 in Table 1 were added to vinyl chloride resin in the following formulation to form a film, and tested for antifogging properties and weather resistance.

Anti-fogging test method The test results are shown in Table 3, which is the same as the evaluation method for low-temperature anti-fogging properties in Example 1.

Table 3 Continuation of page 1 0 shots clear person Hiko Shinozaki 3-24-3 Hokone, Itabashi-ku, Tokyo No. Japan Factant Industrial Co., Ltd. Inside the ceremony company

Claims (1)

[Scope of Claims] 1. An antifogging agent for synthetic resins comprising a polyoxyalkylene polyglycerin fatty acid ester obtained by esterifying an alkylene oxide adduct of polyglycerin having 9 to 30 carbon atoms with a fatty acid having 8 to 22 carbon atoms. . 2. The antifogging agent according to claim 1, wherein the number of moles of fullkylene oxide added to 1 mole of polyglycerin is 1 to 10 moles, and the ratio of fatty acid to 1 mole of polyalkylene glycol is 1 to 5 moles.