JPH04117460A - Anti-fogging molded article prepared from thermoplastic synthetic resin - Google Patents

Abstract

PURPOSE:To prepare the title article (a film) excellent in anti-fogging properties and persistence thereof and suitable for use in agriculture and horticulture, food packaging, etc., by incorporating an anti-fogging agent comprising a specific sorbitol deriv. into the article. CONSTITUTION:An anti-fogging agent comprising a sorbitol deriv. obtd. by esterifying 1mol of an adduct of 1-4mol of propylene oxide and 0-20mol of ethylene oxide with 1mol of sorbitol with 1-2mol of a 10-22C fatty acid is incorporated into the title article. The obtd. article, esp. a plasticized polyvinyl chloride resin film, is excellent in anti-fogging properties and persistence thereof and suitable for use in agriculture and horticulture, food packaging, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic synthetic resin molded product with excellent anti-fog and anti-fog properties, and more specifically, to a novel thermoplastic synthetic resin molded product that is particularly useful in fields of application such as agriculture, horticulture, and food packaging. The present invention relates to a thermoplastic resin molded article containing an antifogging agent made of a sorbitol derivative and having excellent antifogging properties, antifogging properties, and durability thereof, particularly a soft vinyl chloride resin film.

Films or sheets of thermoplastic synthetic resins, such as vinyl or olefin resins such as polyvinyl chloride, polyvinylidene chloride, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, etc. (in this specification, films and sheets) Sheets (collectively referred to as films) are widely used as food packaging materials, agricultural coverings, and other materials. However, such thermoplastic synthetic resins are inherently highly hydrophobic, and when using them,
It is well known that moisture condensed on the film surface becomes fine water droplets that cover the film surface and cause cloudiness, which often causes problems during use.

For example, when these films are used as covering materials for cultivated crops, moisture evaporated from the soil condenses on the surface of the film, resulting in cloudy water droplets that prevent sunlight from passing through and cause plant growth due to lack of light. This can lead to problems such as defects, water droplets falling on the crops, damaging young shoots, and causing crop diseases.

Conventionally, in order to prevent such troubles, antifogging synthetic resin films have been generally used in which additives such as surfactants such as sorbitan fatty acid ester, siglycerin fatty acid ester, and glycerin fatty acid ester are kneaded into the film as an antifogging agent. There is.

In particular, when used outdoors for extended periods of time for agricultural purposes, a film with long-lasting anti-fog properties and the best possible anti-fog properties (wet) is desired from the viewpoint of promoting crop growth and suppressing disease damage. .

Therefore, in order to produce a film with good anti-fogging properties and long-lasting properties, it is common practice to add a large amount of anti-fogging agent or to use anti-fogging agents that migrate at different speeds from the inside of the film to the surface in combination. Attempts are being made. However, the former, that is, adding a large amount of heat protectant, not only causes various troubles during the film forming process, but also
It is impractical to increase the amount of antifogging agent beyond a certain point, as this may result in decreased film clarity due to undesirable increases in bleed, and other undesirable consequences. Regarding the latter, the current situation is that an ideally effective antifogging agent has not yet been found. For example, Special Public Interest Publication No. 48-8174
Publication No. 8 proposes a compound obtained by condensing sorbitan fatty acid ester with 0.1 to 30 moles of propylene, butylene, or phenylene oxide as a dropless modifier to be blended into vinyl chloride-based synthetic resin films. has been done. However, the degree of improvement is not necessarily fully satisfactory, and improvement in the negative layer is desired.

In addition, Japanese Patent Publication No. 55-9431 discloses that an adduct of sorbitol with 1 to 20 moles of ethylene oxide having a carbon atom number of 1 to 20
It has been disclosed that an antifogging agent esterified with 0 to 22 fatty acids is added to a vinyl chloride polymer as an antifogging agent, but such an antifogging agent does not have a sufficient antifogging effect, especially at low temperatures. When a film containing this compound is spread on a greenhouse as an agricultural covering material, it is impossible to prevent the occurrence of fog inside the greenhouse.

Therefore, the present inventors aimed to provide an antifogging agent that can be used in a wide range of fields where antifogging properties are desired, and exhibits excellent antifogging and antifogging effects and excellent durability thereof. I have been conducting intensive research.

As a result, a class of sorbitol derivatives obtained by further esterification with fatty acids of the products obtained by adding propylene oxide and optionally ethylene oxide to sorbitol exhibits excellent wetting properties and their excellent persistence under heat. It is imparted to a plastic synthetic resin molded product, and also shows a fog-preventing effect and sustainability of the fog generation phenomenon in crops and cultivation vinyl greenhouses,
They also discovered that it has excellent initial anti-fogging properties, high-temperature anti-fogging properties, and low-temperature anti-fogging properties, leading to the completion of the present invention.

According to the present invention, the addition product of sorbitol with 1 to 4 moles of propylene oxide and 0 to 20 moles of ethylene oxide can be added to
Provided is a thermoplastic synthetic resin molded article having excellent anti-fogging and anti-fog properties, which is characterized by containing a sorbitol derivative obtained by esterification with 1 to 2 moles of 22 fatty acids.

The thermoplastic synthetic resin film that has been antifogged according to the present invention is antifogged using a conventional sorbitan higher fatty acid ester or a reaction product of the ester and polyalkylene oxide, as shown in the Examples and Comparative Examples described below. It has much better anti-fog properties and durability than other thermoplastic synthetic resin films. It is extremely useful in practice as a coating material and food packaging material.

However, JP-A No. 56-139555 discloses sorbitol adducts with ethylene oxide and propylene oxide as an anti-fogging agent that gives thermoplastic synthetic resin films excellent anti-fog and anti-fog properties as well as their sustainability. An antifogging agent containing a reaction product of a higher fatty acid such as stearic acid and a dibasic acid such as adipic acid as an active ingredient has been disclosed, but thermoplastic synthetic resin films containing this antifogging agent are generally processed using high-frequency sewing machines. It has poor sealing properties and low blocking resistance, which poses problems when used as agricultural covering materials.

On the other hand, the antifogging thermoplastic synthetic resin film provided by the present invention has very excellent rollability and blocking resistance.

As mentioned above, the antifogging agent blended into the thermoplastic synthetic resin molded article of the present invention is composed of sorbitol and propylene oxide.
4 mol of ethylene oxide and 0 to 20 mol of ethylene oxide, the product further has 10 to 2 carbon atoms.
The active ingredient is a sorbitol derivative obtained by esterification with 1 to 2 moles of two fatty acids.

The addition of propylene oxide and ethylene oxide to sorbitol can be carried out by methods known per se. For example, this can be carried out by bubbling propylene oxide and optionally ethylene oxide into the sorbitol while heating it to about 140 to about 150° C. in the absence of a solvent in an autoclave. The addition reaction is usually carried out in the presence of an alkali catalyst, such as sodium hydroxide or potassium hydroxide, and once the desired number of moles of propylene oxide and ethylene oxide are injected, the bubbling is stopped and the reaction is continued with heating and stirring. Complete it. When adding ethylene oxide in addition to propylene oxide, there is no particular restriction on the order of blowing the two, and either one may be blown first (or both may be blown at the same time).

As a result, a Zrucht-ru alkylene oxide addition product is obtained, to which propylene oxide and ethylene oxide are added in amounts approximately equivalent to the propylene oxide and ethylene oxide blown into the reactor.

The number of moles of propylene oxide added is in the range of 1 to 4 moles, particularly preferably in the range of 1 to 3 moles. Further, the number of moles of ethylene oxide added is in the range of 0 to 20 moles, and particularly preferably in the range of 0 to 5 moles. When the number of moles of propylene oxide added is less than 1 mole or more than 4 moles, the antifogging properties of the resulting antifogging agent at low temperatures tend to decrease. Also, ethylene oxide is 2
Although it is possible to add 0 mole or more, it is not expected to improve the effects associated with it, and is of no practical significance.

The thus obtained addition product may be purified if necessary, but is usually directly esterified with a fatty acid having 10 to 22 carbon atoms. The fatty acids that can be used for this esterification may be of either saturated or unsaturated type, such as capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, valmitic acid, and Phosphoric acid, stearic acid, petroselic acid, 7-octadecenoic acid, oleic acid, elaidic acid, linoleic acid, lylinic acid, ricinoleic acid, isostearic acid, 12-hydroxystearic acid, 12-ketostearic acid, nonadecanoic acid, behenic acid, Examples include brassic acid and erucic acid, and these may be used alone or in combination of two or more. Among them, the number of carbon atoms is 14~
18 are preferred, especially palmitic acid and stearic acid.

In the esterification reaction, 1 to 2 moles of fatty acid are used per mole of the addition product. It is not preferable to use more than 2 moles of fatty acid because the antifogging performance of the resulting antifogging agent at low and high temperatures decreases.

The esterification reaction between the above addition product and the fatty acid can be carried out by a method known per se, for example, using a suitable esterification catalyst such as p-toluenesulfonic acid, sodium p-toluenesulfonate, maleic acid, sulfuric acid, etc. Esterification can be easily achieved by reacting the adduct with the fatty acid at about 200 to about 250°C in the presence of ester.

The sorbitol derivative obtained in this manner can be appropriately post-treated, such as washing with water, and then incorporated into a thermoplastic synthetic resin as an antifogging agent according to the present invention.

The antifogging agent of the present invention has excellent antifogging and fogging properties and can be used satisfactorily alone, but may also be used in combination with other known antifogging agents. Thereby, the anti-fogging durability can be further improved within the layer. Examples of antifogging agents that can be used in combination include the following. For example, sorbitan fatty acid esters such as sorbitan monostearate and sorbitan monopalmitate; diglycerin fatty acid esters such as diglycerin monopalmitate and diglycerin monostearate; glycerin fatty acid esters such as glycerin monostearate; pentaerythritol monostearate, etc. Dipentaerythritol fatty acid esters such as pentaerythritol fatty acid ester and dipentaerythritol monopalmitate: sorbitan monopalmitate and half adipate,
Sorbitan and diglycerin fatty acid/dibasic acid ester such as diglycerin monostearate/half glutamic acid ester; and condensates of these with alkylene oxide such as ethylene oxide, propylene oxide, etc., such as polyoxyethylene (2 mol sorbitan monostearate) and polyoxyethylene fatty alcohols such as polyoxyethylene lauryl ether; and polyoxyethylene fatty acid esters such as polyoxyethylene monostearate.

When the sorbitol derivative of the present invention is used alone as an antifogging agent, the sorbitol derivative is generally 05 to 3.0 parts by weight, preferably 1.0 to 2.5 parts by weight per 100 parts by weight of the thermoplastic synthetic resin. When used in combination with other antifogging agents as mentioned above,
The sorbitol derivative and other antifogging agents are generally blended in an amount of 0.5 to 3.0 parts by weight, preferably 1.0 to 2.5 parts by weight, per 100 parts by weight of the thermoplastic synthetic resin. In this case, it is desirable that the sorbitol derivative accounts for 30 to 100 parts by weight of the total amount of the antifogging agent.

Therefore, the sorbitol derivative of the present invention can be blended with various thermoplastic synthetic resins and molded into antifogging synthetic resin films and various other molded products desired to have antifogging properties, and has excellent antifogging properties. It can be made into a molded article that has properties and durability.

When producing an antifogging synthetic resin film, a thermoplastic resin composition prepared by blending a thermoplastic synthetic resin with the antifogging agent of the present invention and optionally various additives is prepared by any film forming means known per se, For example, the antifogging synthetic resin film according to the present invention can be obtained by forming it into a film shape by means such as melt extrusion or calendering. The films thus obtained can generally have a thickness of 50 to 200 microns.

Examples of thermoplastic synthetic resins used to form such films include polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyamide, polymethyl methacrylate, polycarbonate, polyvinyl alcohol, polyvinyl Vinyl chloride-based synthetic resins such as butyral, polystyrene, polyacrylate, and mixtures thereof; for example, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-propylene copolymer, vinyl chloride-vinylidene chloride copolymer Olefinic synthetic resins such as polymerized, cyclized vinyl-acrylic acid ester copolymers and mixtures thereof, such as ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylene-butylene copolymers, ethylene-ethyl Examples include acrylate copolymers.

Examples of additives other than antifogging agents that can be incorporated into these thermoplastic synthetic resins include plasticizers, lubricants, antioxidants, antistatic agents, heat stabilizers, ultraviolet absorbers, and pigments. Examples of plasticizers that can be incorporated include dibutyl phthalate, dioctyl phthalate, diisodecyl phthalate, dioctyl adipate, dioctyl sebacate, tricresyl phosphate, butyl benzyl phthalate, epoxidized soybean oil, epoxidized linseed oil, and epoxy resin. etc. are mentioned,
Examples of lubricants include ethylene bisstearylamide, butyl stearate paraffin wax, low molecular weight polyethylene, montan acid wax, stearic acid, and stearyl alcohol, and examples of antioxidants include:
For example, 2,6-di-tert-butyl-4-methylphenol, 2゜4.6-tri-tert-butylphenol, 2.2'-
Examples include methylenebis(4-methyl-6-tert-butylphenol), 4,4'-thiobis-(3-methyl-6-tert-butylphenol), and phenyl α-naphthylamine.

Further, as antistatic agents, for example, polyoxyethylene alkylamides, alkylolamides, ethanolamides, alkyl phosphates, alkyl sulfates, etc. can be used, and as heat stabilizers, for example, dibutyl tin maleate, dibutyl tin dilaurate, stearate, etc. can be used. Calcium phosphate, zinc ricinoleate, triphenyl phosphite, etc. are suitable.

Furthermore, the UV absorbers that can be blended include, for example, hydroquinone-based UV absorbers such as hydroquinone and hydroquinone disalicylate; salicylic acid-based UV absorbers such as phenyl salicylate and paraoctylphenyl salicylate; 2-hydroxy-4 -methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-methoxy-2-carboxybenzophenone, 2,4-dihydroxybenzophenone, 2
．． 2'-dihydroquine-4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4methoxybenzophenone, 2-hydroxy-4methoxy-5-sulfone benzophenone, 2,24,4'-tetrahydroxybenzophenone, etc. Benzophenone UV absorber: 2-
(2'-hydroxy-5'-methylphenyl)benzotriazole, 2- (2'-hydroxy-5'methylphenyl)-5,6-dichlorobenzotriazole, 2-
(2'-hydroxy-5'-tert-butylphenyl)-5-chlorobenzotriazole, 2- (2=hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2- (2'
-Hydroxy-3',5'-di-tertbutylphenyl)-5-chlorobenzotriazole, 2- (2'-
Hydroxy-5'-phenylphenyl)-5-chlorobenzotriazole, 2(2'-hydroxy-5'-phenylphenyl)benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)-5,6-di Examples include benzotriazole ultraviolet absorbers such as chlorobenzotriazole.

Further, examples of blended pigments include phthalocyanine blue, phthalocyanine green, titanium oxide, chromophthal red, and syncasialet.

The antifogging thermoplastic synthetic resin film of the present invention includes, for example,
It can be used for many purposes such as agriculture, horticulture, packaging, building materials, leisure, and electrical products. In particular, farm applications such as agricultural vinyl: For example, when used as a covering material for facility cultivation of crops, clouding due to moisture evaporated from the cultivated crops and soil is prevented, and the growth of crops is prevented without interfering with the penetration of sunlight. It is good for plants, and there are few diseases caused by falling water droplets.

The antifogging agent made of the sorbitol derivative of the present invention can also be used for packaging purposes such as food packaging, for example, when used in packaging materials for foods containing moisture, such as fruits and vegetables, to prevent fogging due to moisture. Packaging materials do not become cloudy and can maintain transparency. Alternatively, when fresh foods are packaged in a film and sold, they are placed in a low-temperature display case to maintain freshness, but if the antifogging agent of the present invention is added to this film, the moisture contained in the fresh foods can be reduced. It is possible to prevent the problem of clouding caused by condensation on the film surface, and the contents of the package can be confirmed, thereby increasing the display effect in stores.

The present invention will be further explained by examples, but the present invention is not limited only to the following examples. In the following examples, unless otherwise specified, "parts" indicate parts by weight.

Example A (Production example of antifogging agent) Synthesis of chill 1 mole of sorbitol (MW 182) was dissolved in an autoclave, and a commonly used alkali catalyst, NaOH0,
003 mol and under the pressure of 1 mol of propylene oxide 1
The addition reaction is carried out at 45° C. for 7 hours.

Next, polyoxypropylene (1 mol) and polyoxyethylene (
4 mol) sorbitol is obtained.

The thus obtained polyoxypropylene (1 mol), polyoxine ethylene (5 mol), and sorbitol (1 mol) were mixed with stearic acid (MW 2
84) Perform an esterification reaction with 2 mol at 200° C. for 6 hours to obtain polyoxypropylene (1 mol) polyoxyethylene (4 mol) sorbitol distearate.

Example B (Production example of antifogging agent) Synthesis of stell Dissolve 1 mol of sorbitol in an autoclave, add 080.003 mol of commonly used alkaline catalyst Na, and add 3 mol of propylene oxide under pressure at 150°C for 6 hours. Perform a reaction.

Next, an addition reaction is carried out under the pressure of 3 moles of ethylene oxide at 150° C. for 3 hours to obtain polyoxypropylene (3 moles), polyoxyethylene (3 moles), and sorbitol.

The obtained polyoxypropylene (3 mol), polyoxyethylene (3 mol), and 1 mol of sorbitol were mixed with 0.02 mol of the commonly used esterification catalyst paratoluenesulfonic acid.
An esterification reaction was carried out with 1 mol of stearic acid at 200°C for 6 hours in the presence of 3 mol of polyoxypropylene (3
mol) polyoxyethylene (3 mol) sorbitol monostearate is obtained.

Example C (Production example of antifogging agent) 1 mol of sorbitol was dissolved in an autoclave, 3 mol of a commonly used alkali catalyst KOHO, 000 was added,
145 under pressure of 1 mole of propylene oxide (MW 58)
The addition reaction is carried out for 7 hours at °C.

Next, an addition reaction is carried out at 150° C. for 3 hours under the pressure of 5 moles of ethylene oxide to obtain polyquine propylene (1 mole), polyoxyethylene (5 moles), and sorbitol.

The obtained polyoxypropylene (1 mol), polyoxyethylene (5 mol), and 1 mol of sorbitol were mixed with the commonly used esterification catalyst para-toluenesulfonic acid (0.03 mol).
An esterification reaction is carried out with 2 moles of behenic acid at 200° C. for 6 hours to obtain polyoxypropylene (1 mol), polyoxyethylene (5 mol), and sorbitol di-behenic acid ester.

Example D (Production example of antifogging agent) 1 mol of sorbitol was dissolved in an autoclave, 3 mol of a commonly used alkali catalyst NaOHO was added, and an addition reaction was carried out at 145°C for 7 hours under the pressure of 2 mol of propylene oxide. , polyoxypropylene (2 mol) gives sorbitol.

This polyoxypropylene (2 mol) and 1 mol of sorbitol were subjected to an esterification reaction with 1 mol of valmitic acid at 200°C for 6 hours in the presence of 0.02 mol of para-toluenesulfonic acid, a commonly used esterification catalyst. Oxypropylene (2 mol) sorbitol mono-palmitic acid ester is obtained.

Example E (Production example of antifogging agent) Dissolve 1 mol of sorbitol in an autoclave, add 0,003 mol of commonly used alkali catalyst NaOH, and carry out an addition reaction at 145°C for 7 hours under the pressure of 4 mol of propylene oxide. .

Next, an addition reaction is carried out at 145° C. for 3 hours under the pressure of 10 moles of ethylene oxide to obtain polyoxypropylene (4 moles), polyoxyethylene (10 moles), and sorbitol.

This polyoxypropylene (4 mol), polyoxydiethylene (10 mol), and 1 mol of sorbitol were mixed with 2 mol of stearic acid at 200°C in the presence of 0.02 mol of paratoluenesulfonic acid, a commonly used esterification catalyst. The esterification reaction was carried out for 6 hours to obtain polyoxypropylene (4 mol), polyoxyethylene (10 mol), and sorbitol di-stearate.

Example 1 and Comparative Examples 1 to 4 100 parts of polyvinyl chloride, 45 parts of dioctyl phthalate, 2 parts of epoxidized soybean oil, 3 parts of tricresyl phosphate
part, barium stearate 0.5 part, zinc stearate 1.0 part, triphenyl phosphite 05 part and polyoxypropylene (1 mol) obtained in Example A, polyoxyethylene (4 mol), sorbitol distearate. 1.5 parts were mixed. Next, a film having a thickness of 0.1 m/m was prepared from the mixture using a calendar roll in a conventional manner. The performance of this film is shown in Tables 1 and 2 below.

For comparison, these tables also include the results of measuring the performance of films prepared in the same manner as in Example 1, in addition to using the following antifogging agents instead of the antifogging agents of the present invention. show.

“Sou” reward! 1 Antifogging agent 1 Polyoxyethylene (5 mol) Sorhitol distearate 2 Polyoxyethylene (2 mol) Sorbitan monostearate 3 Polyquinepropylene (1 mol) Sorbitan monostearate Sorbitan monostearate Polyoxypropylene Bitan mono Palmitate sol polyoxypropylene (2 mol) Nitan monopalmitate solgopolyoxyethylene (2 mol) Thor monopalmitate sol polyoxypropylene (5 mol) Vitol monopalmitate sol Example 2 In Example 1, the present invention 0.8 parts of antifogging agent.
A film was prepared in the same manner as in Example 1 except that 7 parts of a known antifogging agent sorbitan monostearate was used in combination.

The performance of this film is shown in Tables 1 and 2 below.

Example 3 In Example 1, the antifogging agent of the present invention obtained in Example B polyoxypropylene (3 mol) polyoxyethylene (
A film was prepared in the same manner as in Example 1 except that sorbitol monostearate (3 mol) was used. The performance of this film is shown in Tables 1 and 2 below.

Example 4 In Example 1, the antifogging agent of the present invention obtained in Example C polyoxypropylene (1 mol) polyoxyethylene (
A film was prepared in the same manner as in Example 1 except that sorbitol dibehenic acid ester (5 mol) was used. The performance of this film is shown in Tables 1 and 2 below.

Example 5 A film was prepared in the same manner as in Example 1 except that the antifogging agent polyoxypropylene (2 mol) sorbitol monopalmitate of the present invention obtained in Example 1 was used. The performance of this film is shown in Tables 1 and 2 below.

Example 6 In Example 1, Example E. Example 1 was carried out in the same manner as in Example 1, except that 07 parts of sorbitan monostearate was used together with 0.8 parts of the antifogging agent polyoxypropylene (4 mol) polyoxyethylene (10 mol) distearate of the present invention obtained in Example 1. A film was created.

The performance of this film is shown in Tables 1 and 2 below. The test methods and evaluations used to obtain the data shown in Tables 1 and 2 below are as follows.

(1) High temperature anti-fog property... 100cc of 40℃ hot water 2
Place in a 00cc beaker, cover the beaker's opening with a film, and secure and seal with a rubber band and tape. This was fixed in a constant temperature bath at the same temperature, and the condensed state of the film was maintained for a certain period of 60 minutes.
Evaluate by observing after minutes.

Low-temperature anti-fogging properties...100cc of 20°C water to 200c
C. The film is placed in a beaker, fixed in a constant temperature bath at 5° C., and evaluated by observing the condensation state of the film after a certain period of time (60 minutes).

The above high temperature and low temperature antifogging properties are evaluated using the following 10 ranks. The results are shown in Table 1. The larger the evaluation value, the better the antifogging properties.

The water droplet adhesion area on the inner surface of the film is less than 5% The water droplet adhesion area on the film inner surface is 5% or more and less than 10% The water droplet adhesion area on the film inner surface is 10% or more and less than 20% The water droplet adhesion area on the film inner surface is 10% or more - less than 30% 20% Water droplet adhesion area on the inner surface of the film is 40% or more - less than 50% Water droplet adhesion area on the film inner surface is 50% or more - 60% Water droplet adhesion area on the inner surface of the film is 60% or more and less than 70% Water droplet adhesion area on the inner surface of the film is 70% or more and less than 80% Water droplet adhesion area on the inner surface of the film is 80% or more Heat protection durability...Water Put 100cc into a 200CC beaker, cover the opening of the beaker with a film, and secure and seal it with a rubber band and tape. Fix the beaker so that the water surface height in the bathtub and the water surface height in the beaker are approximately the same. The temperature of the bathtub was maintained at 40° C. for 4 days, and the condensation state of the film was evaluated at a certain time using a cycle of heating for 1 day.

The above heat protection durability is evaluated based on the following 10 ranks. The results are shown in Table 1. The larger the evaluation value, the better the anti-fog durability.

Fog evaluation: The film was spread over a pipe house with a height of 2.7 m, a width of 46 m, and a length of 6.7 m, and a photovoltaic illuminance meter [Tokyo Kogaku Kikai Co., Ltd.] was measured at the center of the house at a height of about 50 cm. The solar transmittance was measured as follows.

The solar transmittance inside the house was measured when fog appeared in the evening, the greenhouse was immediately ventilated, and after the fog disappeared, the solar transmittance was measured again.

The average transmittance for 3 days is shown in Table 2.

In addition, Table 2 shows the average fog generation time for 5 days as determined by visual observation. The shorter the fog formation time, the faster the fog disappears.

As is clear from the evaluation results of antifogging properties and durability shown in Table 1, the film containing the heat protectant of the present invention does not contain the conventional antifogging agent sorbitan monostearate or its alkylene oxide adduct. It can be seen that the anti-fogging properties and the long-lasting effect are significantly superior to that of the film containing the additive.

Furthermore, as is clear from Table 2, the antifogging agent-added film of the present invention is superior to the conventional antifogging agent-containing film in the expansion house, with significantly less fog generation.

As mentioned above, the film using the antifogging agent of the present invention has a good antifogging effect and has an unprecedented antifogging durability, especially for agricultural films that are used continuously for a long time. It is suitable for use, and since the generation of fog inside the greenhouse is extremely small compared to conventional films, it is effective in suppressing diseases of agricultural crops, and its utility value is extremely large.

Procedural Amendment Form G) % Formula % l, Indication of Case 1990 Patent Application No. 267551 2, Name of Invention Antifogging Thermoplastic Synthetic Resin Molded Product 3, Person Making Amendment Relationship to Case Name of Patent Applicant Title Nippon Carbide Industries Co., Ltd. 4, Agent
Person: 107 5. Date of amendment order: August 27, 1991 (Delivery port) 6. Specification subject to amendment 7. Contents of amendment As shown in the engraving of the specification originally attached to the application (changes in content) none)

Claims (1)

[Claims] 1. Sorbitol derivatives obtained by esterifying an addition product of sorbitol with 1 to 4 moles of propylene oxide and 0 to 20 moles of ethylene oxide with 1 to 2 moles of a fatty acid having 10 to 22 carbon atoms per mole of the adduct. A thermoplastic synthetic resin molded product with excellent anti-fog and anti-fog properties.