JP4991095B2 - Anti-fogging sheet and container using the same - Google Patents

Description

  The present invention relates to an antifogging sheet having high antifogging properties and anti-blocking properties, a method for producing the same, and a container using the sheet.

  Hydrophobic synthetic resin sheets such as styrene resin sheets have low antifogging properties. Therefore, when a sheet is formed into a container and a food or the like is accommodated, water vapor adheres to the surface of the container as fine water droplets due to changes in temperature and humidity, resulting in cloudiness and lowering transparency.

  In Japanese Patent Publication No. 63-62538 (Patent Document 1), sucrose fatty acid ester (A), unmodified polyvinyl alcohol (B) having a polymerization degree of 800 or less, and silicone emulsion (C) are prepared as follows: A: B: C = 1 : A method of applying an aqueous solution containing 0.5 to 2: 0.5 to 3 (pure mass ratio) to a styrene resin film is disclosed.

In JP-A-10-309785 (Patent Document 2), one side is coated with a mixture of sucrose fatty acid ester and methylcellulose 10 to 50 mg / m ² , and this coating layer is further coated with silicone oil. A styrenic resin sheet having the other surface coated with silicone oil is disclosed. This document describes that the silicone oil coating amount on the antifogging treatment agent is ² to 14 mg / m ² , and in Comparative Example 5, the silicone oil coating amount is 18 mg / m ^{2 with} respect to the sucrose fatty acid ester coating amount. In the sheet having an oil coating amount of 1.2 mg / m ² , blocking occurs in the sheet.

  Further, in Japanese Patent No. 3241997 (Patent Document 3), a surface treatment agent containing a sucrose fatty acid ester, a silicone emulsion, a polysaccharide and / or a hydrophilic polymer (excluding polyvinyl alcohol) is used as a polymer. Application to at least one side of the film is disclosed. In this surface treating agent, the ratio of the silicone emulsion is 20 to 1000 parts by weight as a solid content with respect to 100 parts by weight of the sucrose fatty acid ester.

  A resin sheet (for example, a styrene resin sheet) provided for container molding is, for example, melt-kneaded resin, extruded into a sheet, biaxially stretching the generated sheet, and then applying an antifogging agent, It is dried and wound up into a roll. And in container shaping | molding, the resin sheet is drawn out from the roll and the container is shape | molded by thermoforming. However, with the winding of the resin sheet, the antifogging agent is brought into contact with the non-fogging treated surface of the resin sheet and transferred, and also in the container molding process, the antifogging agent is prevented by contact with a heating body such as a hot plate. The antifogging property and blocking resistance of the resin sheet and container are greatly reduced because of the transfer of the clouding agent. In particular, when a container is formed by deep drawing, the antifogging property is greatly reduced. Further, the molding machine is soiled by the antifogging agent. Furthermore, in order to improve the releasability of the antifogging sheet, a relatively large amount of silicone oil is required.

  These antifogging sheets or films containing silicone oil have high blocking resistance. However, these antifogging sheets are still not sufficiently antifogging. That is, the anti-fogging sheet has anti-fogging properties (high-temperature anti-fogging property) against water vapor generated from the contents when, for example, high-temperature contents are contained in the container, in particular, the contents containing moisture in the container. When storing (foods etc.) and storing at low temperature, antifogging property (low temperature antifogging property) against water vapor or condensation is low. Further, the antifogging property is greatly reduced by winding the sheet or forming the container.

JP-A-2002-46232 (Patent Document 4) and JP-A-2002-47366 (Patent Document 5) disclose at least one antifogging selected from sucrose fatty acid ester and polyglycerin fatty acid ester on one surface. agent 5 to 30 mg / m ² was applied, the other surface in ether multimeric compound (polyoxyethylene - polyoxypropylene block copolymer) a release agent composed and 3 to 30 mg / m ² coating or the like A polystyrene-based sheet is disclosed. JP 2002-86639 A (Patent Document 6) discloses, on one surface, at least one fatty acid ester selected from sucrose fatty acid ester and polyglycerin fatty acid ester, and an ether-based multimer (polyoxyethylene-poly An antifogging agent composed of oxypropylene block copolymer, polyethylene glycol) and polyvinyl alcohol is applied, and ether-based polymers (polyoxyethylene-polyoxypropylene block copolymer, polyethylene glycol) are applied to the other surface. A polystyrene-based resin antifogging sheet coated with a release agent composed of) is disclosed.

However, since these anti-fogging sheets use an ether-based multimer as a release agent, blocking resistance and releasability are greatly reduced as compared with a sheet using silicone oil. Furthermore, when it comes into contact with a heating body such as a hot plate during the molding process, the hot plate becomes dirty, thereby reducing transparency and reducing the quality of the container.
Japanese Examined Patent Publication No. 63-62538 JP-A-10-309785 Japanese Patent No. 3241797 JP 2002-46232 A JP 2002-47366 A JP 2002-86639 A

  Accordingly, an object of the present invention is to provide a resin sheet having high antifogging properties and releasability, a method for producing the same, and a container using the sheet.

  Another object of the present invention is to provide an antifogging resin sheet that can maintain high antifogging properties even when subjected to winding or thermoforming, a method for producing the same, and a container.

  Still another object of the present invention is to provide an antifogging resin sheet having a high releasability (or blocking resistance) even when the amount of silicone oil used is small, a method for producing the same, and a container.

  As a result of intensive investigations to achieve the above-mentioned problems, the present inventor has at least one surface of a resin sheet having a specific surface form as a component composed of a polyhydric alcohol fatty acid ester and a specific hydrophilic polymer. It was found that when coated, it was possible to achieve both high antifogging properties and releasability, and the present invention was completed.

That is, the coated resin sheet of the present invention is a sheet in which a coating layer composed of a polyhydric alcohol fatty acid ester and a hydrophilic polymer is formed on at least one surface of the resin sheet, A non-ether-based hydrophilic polymer having at least one molecule selected from a polysaccharide, an acrylic acid polymer or a salt thereof, and a vinylpyrrolidone homopolymer or copolymer; and polyoxyethylene-polyoxypropylene An ether-based hydrophilic polymer composed of a block copolymer, and the proportion of the ether-based hydrophilic polymer is 10 to 500 parts by weight with respect to 100 parts by weight of the non-ether-based hydrophilic polymer. In addition, protrusions having a height of 0.2 to ² μm are formed on the surface of the coating layer at an average rate of 5 to 50 per 1 mm ² . The polyhydric alcohol fatty acid ester may be selected from various fatty acid esters such as sucrose fatty acid ester and polyglycerin fatty acid ester . Et al is, the covering layer may contain silicone oil and silicone emulsions.

The proportion of the component may be, for example, about 1 to 100 parts by weight of the hydrophilic polymer and 0 to 100 parts by weight (especially 1 to 50 parts by weight) of the silicone oil with respect to 100 parts by weight of the polyhydric alcohol fatty acid ester. Good.

In the resin sheet, a coating layer may be formed on one surface of the resin sheet, and a wetting index on the other surface may be about 30 to 55 dyn / cm. On the other surface, protrusions having a height of 0.2 to ² μm may be formed at an average rate of 5 to 50 per 1 mm ² . Further, a release layer made of silicone oil may be formed on the other surface.

  The resin sheet may be a styrene resin sheet. In particular, it may be composed of 100 parts by weight of a styrene resin and 0.001 to 5 parts by weight of crosslinked organic particles. The styrene resin sheet is composed of 100 parts by weight of styrene resin, 0.2 to 1.5 parts by weight of rubber-reinforced styrene resin, and 0.003 to 0.05 parts by weight of crosslinked styrene resin particles. Also good.

The present invention further provides the production of the sheet in which a coating layer is formed on at least one surface of a resin sheet on which protrusions having a height of 0.2 to ² μm are formed at an average rate of 5 to 50 per 1 mm ^2. Also includes a method. Furthermore, the container formed with the said sheet | seat is also included.

  In this specification, “sheet” is used to mean a two-dimensional structure such as a film or a plate. The “ether-based hydrophilic polymer” also includes an ethylene oxide adduct whose molecular weight is increased by addition of ethylene oxide.

  In the present invention, since a specific structure and a specific component are combined, the antifogging property (high temperature antifogging property and low temperature antifogging property) and blocking resistance can be greatly improved. In particular, even if the sheet is subjected to winding or thermoforming, it is possible to maintain high antifogging properties and to improve the releasability (or blocking resistance). Furthermore, even if the amount of silicone oil used is small, high release properties (or blocking resistance) can be imparted. Moreover, the stain | pollution | contamination of the molding machine by an antifogging agent can be reduced.

[Coating (anti-fogging) layer]
In the coated resin sheet of the present invention, a coating (antifogging) layer composed of a polyhydric alcohol fatty acid ester, a hydrophilic polymer, and, if necessary, silicone oil is formed on at least one surface of the resin sheet. . Furthermore, the surface of the coating layer has an average of 5 to 50 projections having a height of 0.2 to ² μm per 1 mm ² .

(Polyhydric alcohol fatty acid ester)
The fatty acid ester constituting the coating layer (or antifogging layer) can be constituted by an ester of a polyhydric alcohol and a fatty acid (particularly a higher fatty acid). Examples of the polyhydric alcohol include C _2-12 alkylene glycols such as ethylene glycol, propylene glycol, butanediol, hexanediol, and neopentyl glycol; diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, and polypropylene. (Poly) oxy C _2-4 alkylene glycol such as glycol and polytetramethylene glycol; glycerin, polyglycerin having a polymerization degree of about 2 to 20 (diglycerin, triglycerin, tetraglycerin, polyglycerin, etc.), trimethylolethane, triglyceride Methylolpropane, pentaerythritol, saccharides (sucrose, sorbitol, mannitol, xylitol, maltitol, sorbitan, oligosaccharide, etc.) What polyhydroxy compounds (polyhydric alcohols), and others. These polyhydric alcohols can be used alone or in combination of two or more.

  Preferred polyhydric alcohols include compounds having three or more hydroxyl groups, such as glycerin, polyglycerin having a degree of polymerization of about 2 to 15, sugars (such as sucrose), and the like.

Examples of fatty acids include C _6-30 saturated fatty acids such as caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, montanic acid, Linderic acid, palmitooleic acid, olein And C _10-24 unsaturated fatty acids such as acid, elaidic acid, isooleic acid, erucic acid, linoleic acid and linolenic acid. These fatty acids may be used alone or in combination of two or more to form a mixed acid ester.

Of these fatty acids, C _8-24 saturated or unsaturated fatty acids, particularly saturated fatty acids are preferred. In many cases, the fatty acid is, for example, a fatty acid containing a C _10-22 fatty acid as a main component (for example, a fatty acid containing a C _12-18 saturated fatty acid such as lauric acid in a proportion of at least 50 mol%).

As fatty acid esters useful for improving antifogging properties, sucrose fatty acid esters and polyglycerin fatty acid esters are preferred, and these fatty acid esters can be used alone or in combination of two or more. Examples of sucrose fatty acid esters include mono to _{hexaesters of} sucrose and C _8-24 saturated fatty acids (particularly C _10-22 saturated fatty acids), such as sucrose fatty acid mono to hexacaprylate, sucrose fatty acids. Mono to hexalaurate, sucrose fatty acid mono to hexastearate, sucrose fatty acid mono to hexabehenate, etc .; mono of sucrose and C _12-24 unsaturated fatty acid (especially C _16-22 unsaturated fatty acid) Or hexaesters such as sucrose fatty acid mono to hexaoleate.

Examples of polyglycerin fatty acid esters include mono to _dodecaesters of polyglycerin having a polymerization degree of about 2 to 16 and C _8-24 saturated fatty acids (particularly C _10-22 saturated fatty acids), such as tetraglycerin mono to tetracaprylic acid esters. , Hexaglycerol mono to hexacaprylate, decaglycerol mono to decaprylate, tetraglycerol mono to tetralaurate, hexaglycerol mono to hexalaurate, decaglycerol mono to decalaurate, tetraglycerol mono to tetrastearin Acid esters, hexaglycerin mono to hexastearic acid ester, decaglycerin mono to decastearic acid ester, tetraglycerin mono to tetrabehenic acid ester, hexaglycerin monono Hekisabehen acid esters, such as decaglycerol mono- to Dekabehen esters; mono- to dodeca esters of polymerization degree 2 to 16 approximately polyglycerol and C _16-24 unsaturated fatty acids (in particular C _16-22 unsaturated fatty acids), for example, Tetraglycerin mono to tetraoleic acid ester, hexaglycerin mono to hexaoleic acid ester, decaglycerin mono to dekaoleic acid ester, tetraglycerin mono to tetraerucic acid ester, hexaglycerin mono to hexaerucic acid ester, decaglycerin mono to decaerucic acid ester, etc. Can be illustrated.

  The HLB (hydrophile-lipophile balance) of the fatty acid ester is not particularly limited, and may be, for example, 2 to 20, preferably 5 to 18, more preferably about 10 to 18, and usually about 12 to 17. .

(Hydrophilic polymer)
The hydrophilic polymer includes a non-ether hydrophilic polymer and an ether hydrophilic polymer.

  Examples of the non-ether hydrophilic polymer include various hydrophilic polymers such as polysaccharides (oligosaccharides, cellulose derivatives), polymers of vinyl monomers or salts thereof. These hydrophilic polymers can be used alone or in combination of two or more. In addition, in order to improve antifogging property, it is preferable not to contain polyvinyl alcohol as a hydrophilic polymer.

  Among the non-ether hydrophilic polymers, the polysaccharide may be, for example, a single polysaccharide, a complex polysaccharide or a derivative thereof. Examples of the polysaccharide include polysaccharides including oligosaccharides, starch derivatives, and cellulose derivatives. Since these polysaccharides are used as foods and food additives, they are highly safe.

  Examples of polysaccharides include starch, phytoglycogen, fructan, galactomannan, glucomannan, mannan, barley and buckwheat glucan, cellulose, hemicellulose, β-1,3-glucan, galactan, araban, xylan, arabogalactan, araboxylan , Alaboglucan, pectin, gum arabic, tragacanth gum, locust bean gum, guar gum, meskit gum, carrageenin, glucuronoxylan, laminaran, inulin, lichenin, fructosan, chitin, chitosan, alginic acid or a salt thereof (such as sodium alginate), hyaluronic acid, Chondroitin sulfate, caroline sulfate, gelatin, agar, fucoidin, troolloi, curdlan, xanthan gum, pullulan, dextran, cyclodextrin, nigella And levan are exemplified. Examples of oligosaccharides (or oligosaccharide alcohols) include disaccharides, trisaccharides, tetrasaccharides, pentasaccharides, hexasaccharides, heptasaccharides, octasaccharides, and decasaccharides. Sugars (such as tetrasaccharides) can be used. The oligosaccharide may be a single sugar and can be used as an oligosaccharide containing a plurality of saccharides, for example, at least tetrasaccharides. The oligosaccharide may contain a branched sugar alcohol.

  Examples of starch derivatives include white dextrin, yellow dextrin, British gum, oxidized starch, acid-treated starch, α-starch, high amylose starch, dialdehyde starch, acetate starch, sodium starch glycolate, hydroxyethyl starch, and phosphate starch. And cationic starch, crosslinked starch, starch organic acid ester, starch inorganic acid ester, alkyl and substituted alkyl starch ether, graft polymerized starch, and derivatives thereof.

Examples of the cellulose derivative include alkyl cellulose (C _1-6 alkyl cellulose such as methyl cellulose, ethyl cellulose, and propyl cellulose), carboxyalkyl cellulose (carboxy C _1-6 alkyl cellulose such as carboxymethyl cellulose, carboxyethyl cellulose, and carboxypropyl cellulose). , Hydroxyalkyl cellulose (hydroxy C _1-6 alkyl cellulose such as hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, etc.), hydroxyalkyl alkyl cellulose (hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose etc.), soluble cellulose acetate, inorganic acid ester (sulfuric acid) Examples include cellulose and cellulose phosphate) It is.

  As polysaccharides, oligosaccharides and cellulose derivatives (alkyl cellulose, carboxyalkyl cellulose, hydroxyalkyl cellulose, hydroxyalkylalkyl cellulose, etc.) are often used.

  Hydrophilic polymers include water soluble polymers, water dispersible polymers and water swellable polymers. As hydrophilic polymer, vinyl monomer, for example, monomer having hydroxyl group, monomer having carboxyl group or sulfonic acid group, monomer having amide group, single monomer having basic nitrogen atom And a single or copolymer having a vinyl ether monomer as a constituent component.

  Examples of the monomer having a hydroxyl group include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate, hydroxyalkyl methacrylates corresponding thereto, polyethylene glycol mono (meth) acrylate, and the like. Examples of the monomer having a carboxyl group include (meth) acrylic acid, maleic acid, fumaric acid, and itaconic acid. Examples of the monomer having a sulfonic acid group include ethylene sulfonic acid and styrene sulfone. An acid etc. can be illustrated. Examples of the monomer having an amide group include (meth) acrylamide, and examples of the monomer having a basic nitrogen atom include N, N-dimethylaminoethyl acrylate and N, N-diethylaminoethyl acrylate. And the corresponding methacrylates, vinylpyrrolidone and the like. Examples of the vinyl ether monomer include alkyl vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isopropyl ether, vinyl butyl ether, and vinyl isobutyl ether.

The hydrophilic polymer containing the monomer as a constituent component is a simple substance such as (meth) acrylic acid ester (such as (meth) acrylic acid C _1-10 alkyl ester), styrene, or carboxylic acid vinyl ester (such as vinyl acetate). It may be a copolymer with a monomer.

  Preferred hydrophilic polymers include water-soluble polymers (acrylic polymers, vinyl polymers). Examples of such a polymer include a polymer having a carboxyl group or a salt thereof (for example, poly (meth) acrylic acid, (meth) acrylic acid-maleic anhydride copolymer, (meth) acrylic acid-vinylsulfone). Acid copolymers, (meth) acrylic acid polymers such as (meth) acrylic acid-methyl methacrylate copolymer and salts thereof), vinyl polymers having an ether group or a basic nitrogen atom (for example, polyalkyl) Polymers having vinylpyrrolidone units such as vinyl ether, alkyl vinyl ether-maleic anhydride copolymer, and polyvinylpyrrolidone (single or copolymer) are preferred. Examples of the salt of the (meth) acrylic acid polymer include alkali metal salts such as sodium salt and potassium salt, ammonium salt, and organic amine salt.

  Among the hydrophilic polymers, (meth) acrylic acid polymers or salts thereof (acrylic polymers such as sodium polyacrylate or salts thereof) that are approved as food additives, vinylpyrrolidone homopolymers or copolymers (Such as polyvinylpyrrolidone) is preferred.

  The ether-based hydrophilic polymer only needs to have at least an oxyethylene unit, and includes an ethylene oxide adduct, a random or block polymer of ethylene oxide, and the like. Ether-based hydrophilic polymers often have surface activity. Representative ether-based hydrophilic polymers include polyoxyethylene-polyoxypropylene block copolymers (hereinafter sometimes simply referred to as POE-POP block copolymers), nonionic surfactants having oxyethylene units. Including. These ether-based hydrophilic polymers can be used alone or in combination of two or more.

The polyoxyethylene-polyoxypropylene block copolymer (POE-POP block copolymer) is composed of an oxyethylene block- (CH ₂ CH ₂ O) _m -and an oxypropylene block- (CH (CH ₃ ) CH ₂ O). _n - is a copolymer composed of a capital, the content of the ethylene oxide chain in the copolymer (m / (m + n) × 100) is 10 to 95% (or weight%) (preferably 20 to 90 % (Or% by weight), more preferably 40 to 90% (or% by weight), particularly 50 to 90% (or% by weight). The block structure of the block copolymer is not particularly limited, and may be a diblock structure of an oxyethylene block and an oxypropylene block, a triblock structure in which oxyethylene blocks are bonded to both ends of the oxypropylene block, or the like. The copolymer of the triblock structure has the following formula: HO— (CH ₂ CH ₂ O) _m1 — (CH (CH ₃ ) CH ₂ O) _n — (CH ₂ CH ₂ O) _m2 —H
(Where m1 + m2 = m)
Can be expressed as

  The molecular weight of the polyoxyethylene-polyoxypropylene block copolymer (POE-POP block copolymer) is not particularly limited. For example, the weight average molecular weight is 1,000 to 50,000, preferably 3,000 to 30,000. More preferably, it can be selected from the range of about 5,000 to 30,000 (for example, 10,000 to 25,000), and usually about 8,000 to 20,000 (for example, 10,000 to 20,000). It may be.

Nonionic surfactants include polyoxyethylene alkyl ethers (such as polyoxyethylene C _12-24 alkyl ether), polyoxyethylene alkyl aryl ethers (such as polyoxyethylene C _6-18 alkyl phenyl ether), polyoxyethylene Ethylene polyhydric alcohol fatty acid ester (polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene castor oil), polyoxyethylene alkylamines (polyoxyethylene C _10-24 alkyl) Amines), polyoxyethylene fatty acid amides (polyoxyethylene C _8-24 fatty acid amide, etc.) and the like. These nonionic surfactants can be used alone or in combination of two or more. As the nonionic surfactant, polyoxyethylene polyhydric alcohol fatty acid ester (such as polyoxyethylene sorbitan fatty acid ester) is often used. As the fatty acid, item illustrative of higher fatty acids (C _6-30 saturated fatty acids, C _10-24 unsaturated fatty acids) of the fatty acid ester can be utilized.

  In the nonionic surfactant, the number of added oxyethylene units may be, for example, 2 to 100, preferably 5 to 50 (for example, 10 to 50), and more preferably about 10 to 30. Further, the HLB of the nonionic surfactant may be, for example, about 5 to 20, preferably about 10 to 20 (for example, 10 to 18).

  In order to maintain high antifogging properties, a non-ether hydrophilic polymer and an ether hydrophilic polymer may be used in combination. When both are combined, the ratio of the ether-based hydrophilic polymer to 100 parts by weight of the non-ether-based hydrophilic polymer is about 0.1 to 1000 parts by weight (for example, 1 to 700 parts by weight, preferably 10 to 500 parts by weight). It may be. As the ether-based hydrophilic polymer, a POE-POP block copolymer and a nonionic surfactant having an oxyethylene unit may be used. The amount is about 1 to 1000 parts by weight (for example, 1 to 500 parts by weight, preferably 5 to 250 parts by weight).

(Silicone oil)
In the present invention, the coating layer may contain a silicone oil having a high antiblocking property and releasability. The type of silicone oil is not particularly limited. For example, alkylpolysiloxanes such as dimethylpolysiloxane, diethylpolysiloxane, and trifluoropropylpolysiloxane; arylpolysiloxanes such as diphenylpolysiloxane; alkylarylpolysiloxanes such as methylphenylpolysiloxane Etc. The silicone oil may be a chain polysiloxane or a cyclic polysiloxane.

Further, the silicone oil can be modified silicone oil such as hydroxyalkyl group (hydroxy C _2-4 alkyl group such as hydroxyethyl group), polyoxyalkylene group, amino group, as long as blocking resistance and releasability can be imparted. A silicone oil having an N-alkylamino group, a glycidyl group or an epoxy group, a polymerizable group (such as a vinyl group or a (meth) acryloyl group) may be used.

  These silicone oils can also be used alone or in combination of two or more. Of these silicone oils, dimethylpolysiloxane having high versatility is usually used. Silicone oil can be used in various forms, but is usually used in the form of a silicone emulsion (emulsion in which silicone oil is emulsified and dispersed).

The viscosity of the silicone oil is not particularly limited. For example, Ostwald viscosity at room temperature (15 to 25 ° C.) is 50 to 50000 centistokes (0.5 × 10 ^{−4 to} 500 × 10 ⁻⁴ m ² / s), preferably 100 to 30000 centistokes (1 × 10 ^{−4 to} 300 × 10 ⁻⁴ m ² / s), more preferably 150 to 30000 centistokes (1.5 × 10 ^{−4 to} 300 × 10 ⁻⁴ m ² / s) Degree.

  In the coating layer, the respective components can be combined within a range that does not impair the antifogging property, blocking resistance (or release property), and the like, for example, from sucrose fatty acid ester and polyglycerin fatty acid ester. At least one selected from at least one selected fatty acid ester (particularly a fatty acid ester composed of at least a sucrose fatty acid ester), a polysaccharide, an acrylic acid polymer or a salt thereof, and a vinylpyrrolidone homopolymer or copolymer. A non-ether type polymer (especially a non-ether type polymer composed of at least a vinylpyrrolidone homopolymer or copolymer), a polyoxyethylene-polyoxypropylene block copolymer, and a nonionic interface having an oxyethylene unit. At least one ether-based hydrophilicity selected from activators Molecules - and (especially at least polyoxyethylene consists of polyoxypropylene block copolymer ether-based hydrophilic polymer), such as a combination of a silicone oil (especially silicone emulsions, such as dimethyl polysiloxane) can be exemplified.

  In the coating layer (or anti-fogging layer), the proportion of each component can be selected within a range that does not impair the anti-fogging property, anti-blocking property (or releasability), and the proportion of the hydrophilic polymer is, for example, multivalent. The amount may be 1 to 100 parts by weight, preferably 3 to 70 parts by weight, and more preferably about 5 to 50 parts by weight with respect to 100 parts by weight of the alcohol fatty acid ester. The usage-amount of silicone oil is 0-100 weight part (for example, 1-100 weight part) with respect to 100 weight part of polyhydric-alcohol fatty acid ester, for example, Preferably 0-50 weight part (for example, 1-50 weight). Part), more preferably about 0 to 30 parts by weight (for example, 1 to 30 parts by weight). In the present invention, even when the amount of silicone oil used is small (particularly even when silicone oil is not used), high blocking resistance and mold release can be obtained.

  Each component may be used alone or in combination of a plurality of components. When combining a plurality of components, the ratio of the second component to 100 parts by weight of the first component is 0.1 to 1000 parts by weight ( For example, it may be about 1 to 500 parts by weight, preferably about 5 to 250 parts by weight. For example, when a sucrose fatty acid ester and a polyglycerin fatty acid ester are used in combination as a polyhydric alcohol fatty acid ester, the ratio of the two is, for example, 1 to 500 parts by weight (for example, 5 parts per 100 parts by weight of the former). ˜300 parts by weight, preferably 5 to 100 parts by weight). When the polysaccharide and the vinylpyrrolidone polymer are used in combination as the hydrophilic polymer, the ratio of both can be selected from a wide range, for example, the latter is 0.1 to 1000 parts by weight with respect to 100 parts by weight. You may select within the range (For example, 1-500 weight part, Preferably it is 10-250 weight part.).

  The coating layer is made of various additives such as stabilizers (antioxidants, ultraviolet absorbers, etc.), fillers, colorants, antistatic agents, flame retardants, lubricants, waxes, preservatives, viscosity modifiers, A thickener, a leveling agent, an antifoaming agent, etc. may be included.

In the present invention, the number of protrusions having a height of 0.2 to 2 μm on the surface of the coating layer is an average of 5 to 50, preferably 5 to 40, more preferably 5 to 35 (especially 5 to 30) per mm ^2. It is formed at a rate of about 1). Since the coated resin sheet of the present invention has such protrusions, it has excellent blocking resistance even if the proportion of silicone oil is small. The coating layer having such projections formed on the surface may contain projections such as particles in the coating layer, but usually by using a resin sheet having such projections formed on the surface. Can be prepared. The shape of the protrusion is not particularly limited, but is usually a structure in which a granular material such as a sphere, an ellipsoid, or a polygon protrudes.

[Resin sheet]
The resin sheet may be various thermoplastic resins having film or sheet moldability, such as polyethylene resin (polyethylene, ethylene-ethyl acrylate copolymer, ionomer, etc.), polypropylene resin (polypropylene, propylene-ethylene copolymer). ), Olefin resins such as poly-4-methylpentene-1; vinyl alcohol resins such as polyvinyl alcohol and ethylene-vinyl alcohol copolymer; vinyl chloride resins such as polyvinyl chloride; styrene resins; polyethylene terephthalate , Homo or copolyester resins having an alkylene arylate unit such as polybutylene terephthalate; nylon or polyamide resins; polyacrylonitrile resins; polycarbonate resins; polyphenylene oxide resins; Etc. In may form a cellulose derivative; sulfone-based resin. These resins can be used alone or in combination of two or more. The resin sheet may be a single layer sheet or a laminated sheet in which a plurality of resin layers are laminated. The thickness of the resin sheet can be appropriately selected depending on the application, and is, for example, about 10 μm to 5 mm, preferably about 25 μm to 1 mm. When used for container molding, the thickness of the resin sheet may be, for example, 50 μm to 5 mm, preferably 100 to 3000 μm (for example, 100 to 1000 μm), and more preferably about 130 to 500 μm.

  A preferable resin sheet can be composed of a sheet having molding processability, particularly a hydrophobic synthetic resin sheet, such as an olefin resin (particularly polypropylene resin), a polyester resin (particularly polyethylene terephthalate resin), or a styrene resin. In particular, a resin sheet having high moldability, for example, a styrene resin sheet is preferable. The polystyrene sheet is highly transparent.

  Styrenic resins include homopolymers containing aromatic vinyl monomers (such as styrene, vinyltoluene, and α-methylstyrene) as constituents, and copolymerization of aromatic vinyl monomers and copolymerizable monomers. Combinations and mixtures thereof are included. More specifically, examples of the styrene resin include general-purpose polystyrene (GPPS), rubber-reinforced polystyrene (high impact polystyrene HIPS), polystyrene-polybutadiene-polystyrene block copolymer, acrylonitrile-styrene copolymer (AS resin). ), Acrylonitrile-butadiene-styrene copolymer (ABS resin), styrene-butadiene block copolymer, rubber component X (acrylic rubber, chlorinated polyethylene, ethylene-propylene rubber (EPDM), ethylene-vinyl acetate copolymer, etc. AXS resin obtained by graft polymerization of acrylonitrile A and styrene S, styrene-methyl methacrylate copolymer, acrylonitrile-styrene-methyl methacrylate copolymer, and the like. These styrenic resins can be used alone or in admixture of two or more.

  The resin sheet may have protrusions formed on the surface thereof in order to form protrusions on the coating layer. The protrusions on the surface of the resin sheet may be formed by coating the surface of the resin sheet with a layer containing protrusions such as particles, or may be formed by kneading protrusions such as particles into the resin sheet. Among these, from the viewpoint of simplicity, a method of kneading the particles into the resin sheet, that is, a method of constituting the resin sheet with the resin and the particles is preferable. The particles include organic particles and inorganic particles. These particles can be used alone or in combination of two or more.

  Examples of inorganic particles include metal powder, white carbon, metal silicate (calcium silicate, aluminum silicate, magnesium silicate, magnesium aluminosilicate, etc.), mineral particles (zeolite, diatomaceous earth, calcined siliceous earth, talc, kaolin, Sericite, bentonite, smectite, clay, etc.), metal carbonates (magnesium carbonate, heavy calcium carbonate, light calcium carbonate, etc.), metal oxides (alumina, silica, zinc oxide, titanium dioxide etc.), metal hydroxides ( Aluminum hydroxide, calcium hydroxide, magnesium hydroxide, etc.), metal sulfates (calcium sulfate, barium sulfate, etc.) and the like.

  The organic particles can be composed of thermoplastic resins, thermosetting resins, rubber particles, or the like. Examples of thermoplastic resins include polyolefin resins, styrene resins, acrylic resins, polycarbonate resins, polyester resins, polyamide resins, polyphenylene oxide resins, vinyl resins, and other crosslinked or non-crosslinked organic particles, waxes. Examples thereof include particles (Fischer-Tropsch wax, ester wax, higher fatty acid or salt thereof, higher fatty acid ester, higher fatty acid amide, etc.). Among these thermoplastic resins, polyolefin resins (for example, crosslinked polyethylene, crosslinked polypropylene, etc.), styrene resins (for example, crosslinked polystyrene, crosslinked polyvinyltoluene, crosslinked styrene-methyl methacrylate copolymer, etc.), acrylic resins (For example, cross-linked polymethyl methacrylate and the like) are preferable. The thermosetting resin is not particularly limited, and examples thereof include organic resins such as silicone resins, amino resins (such as urea resins, melamine resins, and benzoguanamine resins), polyurethane resins, and epoxy resins. Examples of the rubber particles include diene rubber, acrylic rubber, ethylene-α-olefin-polyene copolymer, silicone rubber, hydrogenated diene rubber, and the like. Further, these particles (particularly rubber particles) may be particles dispersed in a thermoplastic resin as a matrix.

  Of these particles, from the viewpoint of releasability (blocking resistance) and compatibility with the resin, crosslinked organic particles, particularly crosslinked resin particles (for example, polyolefin resins, acrylic resins, styrene resins, silicone resins). Resin or the like) or crosslinked or grafted rubber dispersed particles (for example, crosslinked or grafted diene rubber or hydrogenated diene rubber particles) are preferable. As the crosslinked organic particles, particles composed of a resin of the same system as the resin sheet are preferable from the viewpoint of compatibility. These crosslinked organic particles can be used alone or in combination of two or more.

  The ratio of the particles (crosslinked organic particles, etc.) is 0.001-5 parts by weight, preferably 0.003-3 parts by weight, more preferably 0.005-5 parts by weight with respect to 100 parts by weight of the resin (styrene resin, etc.). About 2 parts by weight.

  Furthermore, from the viewpoint of compatibility between the resin constituting the sheet and the particles, it is preferable to use a resin in which crosslinked or graft rubber particles are dispersed in combination with the crosslinked resin particles. In this case, the ratio of the crosslinked resin particles is 0.003 to 0.05 parts by weight, preferably about 0.005 to 0.03 parts by weight with respect to 100 parts by weight of the resin constituting the sheet. The ratio of the resin in which is dispersed is about 0.2 to 1.5 parts by weight, preferably about 0.3 to 1.2 parts by weight with respect to 100 parts by weight of the resin constituting the sheet.

  When the resin sheet is composed of a styrene resin, examples of the crosslinked organic particles include crosslinked styrene resin particles such as crosslinked polystyrene particles, and a styrene resin in which crosslinked or graft rubber particles are dispersed in a matrix resin ( For example, it is also preferable to use a rubber-reinforced styrene resin (such as HIPS) as an additive for the styrene resin. As the rubber particles, for example, diene rubber particles such as polybutadiene (butadiene rubber), isoprene rubber, styrene-butadiene copolymer and the like are preferable. For example, in a matrix composed of a styrene resin by graft copolymerization or the like. It is preferable that the rubber particles are dispersed. The ratio of such rubber particles is 3 to 50 parts by weight, preferably 3 to 20 parts by weight, and more preferably about 5 to 10 parts by weight with respect to 100 parts by weight of the styrene resin. In particular, it is effective to use a combination of crosslinked styrene resin particles and rubber-reinforced styrene resin.

  The average particle diameter of the particles is not particularly limited as long as it is a particle diameter capable of forming the protrusion, and is, for example, about 0.3 to 60 μm, preferably about 0.4 to 50 μm, and more preferably about 0.5 to 40 μm. .

  The shape of the particles is not particularly limited, and may be, for example, spherical, ellipsoidal, polygonal, prismatic, cylindrical, rod-shaped, or indefinite.

  Resin sheets are made of various additives such as stabilizers (antioxidants, UV absorbers, heat stabilizers, etc.), antistatic agents, crystal nucleating agents, hydrocarbon polymers, plasticizers, mineral oil, filling An agent, a coloring agent, etc. may be included.

  The resin sheet can be obtained by a conventional method, for example, a conventional film forming method such as a T-die method or an inflation method. The resin sheet may be unstretched, but is preferably stretched. The stretched film may be a uniaxially stretched film, but is preferably a biaxially stretched film. Moreover, you may heat-process (heat-setting process) a stretched film as needed. Examples of the stretching method include conventional stretching methods such as roll stretching, roll stretching, belt stretching, tenter stretching, tube stretching, and stretching methods combining these. The draw ratio can be appropriately set according to the desired sheet properties, and may be, for example, 1.2 to 20 times, preferably 1.5 to 15 times, and more preferably about 1.5 to 10 times.

The surface of the resin sheet may be subjected to a conventional surface treatment such as corona discharge treatment or high frequency treatment. Since the surface tension of the resin sheet varies depending on the type of the sheet, it cannot be determined unconditionally. However, when measured according to JIS K-6768 “wetting test method for polyethylene and polypropylene films”, it is 30 to 65 dyn / cm (30 × 10 ^{−5 to} 65 × 10 ⁻⁵ N / cm). In the case of a styrene-based resin sheet, the surface tension is 40 to 62 dyn / cm (40 × 10 ^{−5 to} 62 × 10 ⁻⁵ N / cm), preferably 42 to 62 dyn / cm (42 × 10 ⁻⁵ N / cm to 62). × 10 ⁻⁵ N / cm), more preferably about 45 to 60 dyn / cm (45 × 10 ^{−5 to} 60 × 10 ⁻⁵ N / cm).

  When the coating layer is formed on the resin sheet surface having such a surface tension, the adhesion with the coating film can be improved, and the durability of the coating film against water wetting on the sheet surface is improved. In addition, when the surface tension of the sheet surface is too high, the sheet surface is excessively activated, or blocking is likely to occur. Therefore, it becomes difficult to rewind a sheet wound in a roll shape, or when a plurality of molded containers are stacked and punched out, the containers are brought into close contact with each other, and the work efficiency of separating the containers and storing the contents decreases. easy.

[Coating resin sheet or antifogging sheet and method for producing the same]
The coated resin sheet of the present invention includes the resin sheet and a coating layer (or coating layer) formed by coating at least one surface (one surface or both surfaces) of the resin sheet.

  The coated resin sheet of the present invention in which the coating layer is formed is characterized by excellent surface appearance, little decrease in antifogging property even when wound, and high antifogging property and blocking resistance even by deep drawing. is there. Moreover, even if it uses for a shaping | molding process, high anti-fogging property can be maintained. Furthermore, the contamination of the molding machine by the antifogging agent can be reduced.

  The coating layer is usually formed by coating a liquid composition in the form of a coating solution or an impregnating solution. Such a liquid composition may be a non-aqueous liquid composition using an organic solvent as a solvent, but is usually used as an aqueous composition. In the aqueous composition, the solvent may be water alone, water and a hydrophilic solvent (especially a water miscible solvent) [for example, alcohols (methanol, ethanol, isopropanol, etc.), ketones (acetone, etc.), A mixed solvent with ethers (dioxane, tetrahydrofuran, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc.), carbitols, etc.] may be used.

  The coating layer coating solution can be prepared using a conventional mixing stirrer or mixing / dispersing machine, and the silicone oil may be dispersed during the preparation. The viscosity of the coating layer can be appropriately selected as long as the coating property is not impaired. The viscosity of the coating solution is, for example, 5000 cps (= 5 Pa · s) or less (preferably 100 to 3000 cps (= 0.1 to 3.0 Pa · s), more preferably 10 to 2500 cps (= 0.01 to 2.5 Pa). -It may be about s)).

The coating layer of the present invention is characterized by high anti-fogging properties and blocking resistance even when applied in a small amount. Therefore, the coating amount of the coating layer (coating amount after drying) is, for example, be selected from a wide range of about 5 to 150 mg / m ^2, typically, 10-100 mg / m ^2, preferably 15~80mg / m ² ( For example, it may be about ²⁰ to 70 mg / m ² ), more preferably about ²⁰ to 50 mg / m ² , and high antifogging properties and blocking resistance are exhibited even when the coating amount is about 10 to 50 mg / m ² .

In the coated resin sheet of the present invention, a coating layer may be formed on at least one surface of the resin sheet, the coating layer is formed on one surface, and the other surface is formed by corona discharge treatment at 30 to 55 dyn / cm (30 It is preferable that the treatment is performed at about 10 × ^{5 −5 to} 55 × 10 ⁻⁵ N / cm. On the other side, various treatment agents (for example, anti-blocking agents for improving anti-blocking properties, anti-static agents for improving anti-static properties and slip properties, coating agents containing lubricants, etc.) ) (Or coating treatment). In particular, a coating layer may be formed on one surface of the resin sheet, and a release layer (or antiblocking layer) may be formed on the other surface.

  In the present invention, the release layer (or antiblocking layer) is composed of silicone oil. As the silicone oil, the same silicone oil as described above (such as dimethylpolysiloxane) is preferable. In a preferred embodiment, the silicone oil can be used in the form of an emulsion (aqueous emulsion) as described above.

  In addition to silicone oil, the release layer contains various release agents (or antiblocking agents) such as waxes (including mineral waxes, plant waxes, synthetic waxes, etc.), higher fatty acid amides, and the like. However, it is preferable that an ether-based hydrophilic polymer having an oxyethylene unit is contained. As the ether-based hydrophilic polymer having an oxyethylene unit, the same ether-based hydrophilic polymer as described above (nonionic surfactant, for example, polyoxyethylene-polyoxypropylene block copolymer, having an oxyethylene unit) Nonionic surfactants and the like can be used. The ratio of various mold release agents can be selected in the range which does not impair antifogging property or blocking resistance, and is about 0 to 100 parts by weight with respect to 100 parts by weight of silicone oil.

  The processing agent such as a release agent is various additives such as stabilizers (antioxidants, ultraviolet absorbers, etc.), fillers, colorants, antistatic agents, flame retardants, lubricants, waxes, preservatives. Further, it may contain a viscosity modifier, a thickener, a leveling agent, an antifoaming agent and the like. The treatment agent can be usually used in the form of a coating solution or an impregnation solution, and may be a non-aqueous liquid composition using an organic solvent as a solvent, but is usually used as an aqueous composition. In the aqueous composition, the solvent may be water alone or a mixed solvent of water and the above-mentioned hydrophilic solvent (especially water-miscible solvent).

The coating amount of the treating agent (the coating amount after drying) can be selected from a wide range of about 1 to 200 mg / m ² (for example, 5 to 100 mg / m ² ) depending on the type of the treating agent and the like. 100 mg / m ^2, preferably from 3 to 50 mg / m ² (e.g., 5~30mg / m ^2), more preferably about 5 to 25 mg / m ^2.

  It is preferable that protrusions similar to the coating layer are formed on the surface treated with the treatment agent (such as a release agent). As a method of forming the protrusions on the release layer, a method using a resin sheet on which the protrusions are formed, as in the case of the coating layer, may be mentioned.

  The coated resin sheet can be produced by applying a coating solution for the coating layer (or antifogging layer) to at least one surface of the resin sheet. Moreover, a coating resin sheet can be manufactured also by apply | coating the said coating liquid on one surface of the said resin sheet, and apply | coating the said processing agent (for example, mold release agent, an antiblocking agent, etc.) to the other surface. For application of the coating layer coating solution (or treatment agent), conventional coating means such as spray, roll coater, gravure roll coater, knife coater, dip coater and the like can be used. If necessary, the coating layer coating solution (or treatment agent) may be applied multiple times. The coating layer (or anti-fogging layer) or the treatment layer (release layer, etc.) can be usually formed by drying the coating layer after the coating layer coating solution (and treatment agent) is applied to the resin sheet.

  The coated resin sheet may be continuously provided for a post-processing step (such as a container molding step), but is usually often wound into a roll and used for the post-processing step. Even with such winding, the anti-fogging component transfer can be greatly suppressed due to high blocking resistance, and not only high temperature antifogging property but also low temperature antifogging property is maintained, and high antifogging property is maintained over a long period of time. it can. Further, stickiness and whitening can be suppressed, and the transparency and gloss of the resin sheet are not impaired. Therefore, it can be used for various uses, for example, a cover sheet (or film), a packaging sheet (or film) such as food packaging. A coated resin sheet using a resin sheet having high moldability has high secondary moldability and is suitable for molding processing of containers and the like.

[Container and its manufacturing method]
The present invention also discloses a molded article such as a container (such as a food packaging container) formed of the coated resin sheet. Moreover, the container usually has at least a container main body for accommodating a container such as food, and the opening of the container main body may be covered with a wrapping film. Moreover, you may comprise a container with a container main body and the cover body which covers the opening part of the said container main body through a hinge part.

  In a preferred method, the coated resin sheet (or antifogging sheet) is often formed into a container (such as a container for containing a water-containing container such as a food packaging container) by a conventional thermoforming method. . Examples of the thermoforming method (or secondary forming process) include a blow molding method, a vacuum forming method, a pressure forming method (a heating / pressure forming method such as a hot plate heating type pressure forming method, a radiation heating type pressure forming method), a vacuum, and the like. A pressure forming method, a plug assist forming method, a matched mold forming method and the like can be used. When using a stretched resin sheet, a hot plate heating type pressure forming method is usually used in many cases.

  In this invention, even if it uses for such thermoforming (secondary shaping | molding), high anti-fogging property and blocking resistance can be maintained. In particular, even when the coated resin sheet is deep-drawn, it is excellent not only in high-temperature antifogging properties but also in low-temperature antifogging properties and can maintain high antifogging properties.

  In addition, the accommodation that can be accommodated in the secondary molded container is not particularly limited, and may be an accommodation that has little drying or volatilization of moisture. However, since the antifogging property is high, the accommodation containing moisture (food, etc.) Suitable for accommodation). The container of the present invention is also suitable as a container to be used in an environment in which condensation is likely to occur (for example, a container for storing cooked food, etc. in addition to fresh food and cooked food stored at low temperatures) Yes. In addition, even if it uses for the said thermoforming, high transparency and gloss can be ensured and the visibility of the contents can be improved.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In the examples and comparative examples, the following components were used.

[Polyhydric alcohol fatty acid ester]
A-1: Sucrose laurate (Riken Vitamin Co., Ltd., “Riquemar A”, HLB = 15)
A-2: Polyglycerol fatty acid ester (manufactured by Riken Vitamin Co., Ltd., decaglycerol monolaurate “Poem J-0021”, HLB = 15.5)
[Hydrophilic polymer]
B-1: Sodium carboxymethyl cellulose CMC (manufactured by Daicel Chemical Industries, “CMC Daicel 1350”)
B-2: Hydroxypropyl methylcellulose HPMC (manufactured by Shin-Etsu Chemical Co., Ltd., “Metroses 60SH-15”, 2 wt% aqueous solution viscosity 13-18 mPa · s, average methyl group substitution degree 1.9, average hydroxypropyl group Degree of substitution 0.25)
B-3: Sodium polyacrylate PAcNa (manufactured by Nippon Shokubai Co., Ltd., “AQUALIC FH-G”, weight average molecular weight 400 × 10 ^{4 to} 500 × 10 ⁴ )
B-4: Polyvinylpyrrolidone (manufactured by BASF Japan Ltd., “Rubitec K-90”, weight average molecular weight 90 × 10 ^{4 to} 150 × 10 ⁴ , 5 wt% aqueous solution viscosity 80 to 100 mPa · s)
B-5: Polyvinyl alcohol PVA (Kuraray Co., Ltd., “PVA205”)
B-6: Polyoxyethylene-polyoxypropylene block copolymer (Daiichi Kogyo Seiyaku Co., Ltd., “Epan 785”, weight average molecular weight 13000, oxyethylene chain content 85% by weight (or%)).

[Silicone oil]
Dimethyl silicone aqueous emulsion (manufactured by Shin-Etsu Chemical Co., Ltd., “KM9738”, 10,000 centistokes = 100 × 10 ⁻⁴ m ² / s)
Moreover, about the coating resin sheet, the height of the protrusion of the coating resin sheet, the antifogging property after pressing, and the antifogging property of the molded product were evaluated as follows.

[Average number of protrusions]
Using a surface roughness meter (Surfcom 1400A, manufactured by Tokyo Seimitsu Co., Ltd.), each sheet was measured for three-dimensional roughness at 1.5 mm × 1.5 mm square, n = 3, and the height of the protrusions. The number of protrusions having a diameter of 0.2 to 2 μm was counted and converted to the average number of protrusions per 1 mm ² .

[Anti-fogging after pressing]
After cutting the coated resin sheet into a 30 × 30 cm square and stacking the antifogging surface and the release surface together, the two sheets were overlapped (the antifogging surface of the upper sheet and the release surface of the lower sheet were stacked) Using a hand press machine, the pressure was released for 1 hour at a temperature of 30 ° C. with a load of 10 kgf / cm ² (≈98 N / cm ² ), and then the sheet was separated. For the upper sheet, place the sheet in a container containing hot water of 60 ° C. so that the anti-fogging coating surface faces the opening of the container and hit the steam, and leave it in a room temperature environment for 2 minutes. Were visually observed and evaluated according to the following criteria.

◎: The contents can be clearly seen. ○: The contents can be clearly seen. △: The contents can be blurred. ×: The contents cannot be seen.

[Anti-fogging property of molded products]
The sheet was hot plate molded to produce a circular lid member having a diameter of 100 mm and a depth of 30 mm (drawing ratio 0.3). About this circular lid, after placing the lid on a container containing water at 23 ° C. and leaving it in a 5 ° C. environment for 10 minutes, the degree of cloudiness of the lid was visually observed, and the following criteria were used. evaluated.

A: “Anti-fogging” character with font size 5 can be read. ○: “Anti-fogging” character with font size 10 can be read. Δ: “Anti-fogging” character with font size 14 can be read. ×: Font size 18 Can read “anti-fogging” characters.

Reference Examples 1-6, Examples 1-2, and Comparative Examples 1-4
One surface of a biaxially stretched polystyrene sheet (sheet thickness 0.25 mm) having the number of protrusions shown in Table 1 was subjected to corona discharge treatment at 60 dyn / cm (60 × 10 ⁻⁵ N / cm). Prepare an aqueous antifogging agent containing each component in the proportions (parts by weight) shown in Table 1 (in terms of solid content for silicone oil), apply these antifogging agents to the corona discharge treated surface, and dry. Thus, a predetermined antifogging layer was formed. Further, the other surface of the biaxially stretched polystyrene sheet was subjected to corona discharge treatment so as to have a wetting index shown in Table 1. Moreover, about Examples 5-6 and Reference Example 1 , it apply | coats silicone oil as a mold release agent by the ratio (weight part) shown in Table 1 by solid content conversion, and it is predetermined by drying. A mold release layer was formed. The results are shown in Table 1.

  From Table 1, the coating resin sheet of an Example has high anti-fogging property of a molded article as well as anti-fogging property after a press.

Claims (13)

A sheet in which a coating layer composed of a polyhydric alcohol fatty acid ester and a hydrophilic polymer is formed on at least one surface of the resin sheet,
The hydrophilic polymer is a non-ether hydrophilic polymer composed of at least one selected from polysaccharides, acrylic acid polymers or salts thereof, and vinylpyrrolidone homo- or copolymers, and polyoxyethylene -An ether-based hydrophilic polymer composed of a polyoxypropylene block copolymer ,
The ratio of the ether-based hydrophilic polymer is 10 to 500 parts by weight with respect to 100 parts by weight of the non-ether-based hydrophilic polymer, and a protrusion having a height of 0.2 to 2 μm is formed on the surface of the coating layer. A coated resin sheet in which objects are formed at an average rate of 5 to 50 per 1 mm ² .   The sheet according to claim 1, wherein the polyhydric alcohol fatty acid ester is composed of at least one selected from sucrose fatty acid esters and polyglycerin fatty acid esters.   The sheet | seat of Claim 1 in which a coating layer contains 1-100 weight part of hydrophilic polymers and 0-100 weight part of silicone oil with respect to 100 weight part of polyhydric-alcohol fatty acid ester.   The sheet according to claim 1, wherein the coating layer contains 1 to 50 parts by weight of silicone oil with respect to 100 parts by weight of the polyhydric alcohol fatty acid ester.   The sheet according to claim 1, wherein a coating layer is formed on one surface of the resin sheet, and the wetting index of the other surface is 30 to 55 dyn / cm. 6. The sheet according to claim 5 , wherein protrusions having a height of 0.2 to ^{2 [} mu] m are formed on the other surface at an average rate of 5 to 50 per 1 mm < ² >. The sheet according to claim 6, wherein a release layer made of silicone oil is formed on the other surface. The sheet according to any one of claims 1 to 7 , wherein the resin sheet is a styrene resin sheet. The sheet according to claim 8 , wherein the styrene resin sheet is composed of 100 parts by weight of a styrene resin and 0.001 to 5 parts by weight of crosslinked organic particles. The styrene resin sheet is composed of 100 parts by weight of styrene resin, 0.2 to 1.5 parts by weight of rubber-reinforced styrene resin, and 0.003 to 0.05 parts by weight of crosslinked styrene resin particles. 8. The sheet according to 8 . A coating layer composed of polyhydric alcohol fatty acid ester, hydrophilic polymer and silicone emulsion is formed on one side of the resin sheet, and a release layer composed of silicone emulsion is formed on the other side The seat being
The hydrophilic polymer is a non-ether hydrophilic polymer composed of at least one selected from polysaccharides, acrylic acid polymers or salts thereof, and vinylpyrrolidone homo- or copolymers, and polyoxyethylene -An ether-based hydrophilic polymer composed of a polyoxypropylene block copolymer ,
The ratio of the ether-based hydrophilic polymer is 10 to 500 parts by weight with respect to 100 parts by weight of the non-ether-based hydrophilic polymer, and the coating layer is based on 100 parts by weight of the polyhydric alcohol fatty acid ester. In addition to containing 0 to 30 parts by weight of silicone emulsion as solid content,
A coated resin sheet in which protrusions having a height of 0.2 to ² μm are formed on the surfaces of the coating layer and the release layer at an average rate of 5 to 30 per 1 mm ² . ^{2. The} method for producing a sheet according to claim 1, wherein a coating layer is formed on at least one surface of the resin sheet on which protrusions having a height of 0.2 to 2 [mu] m are formed at an average rate of 5 to 50 per 1 mm < ² >.   A container formed of the sheet according to claim 1.