JP2012077262A - Anti-fogging composition, anti-fogging resin sheet, and container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new anti-fogging composition having high transparency and little sticky feeling, capable of showing anti-fogging durability even in an environment both at a high temperature and at a low temperature, and not being easily transferred onto a mold release agent on the rear surface side.SOLUTION: In this anti-fogging composition containing each component of (A) a surfactant, (B) a hydrophilic polymer and (C) shellac, a nonionic surfactant and an anionic surfactant are contained as (A) component, and the (A) component content is 50-99 pts.mass and the total of (B) component content and (C) component content is 50-1 pts.mass to the total 100 pts.mass of (A) component content, (B) component content and (C) component content, and the (B) component content is 1-99 pts.mass and the (C) component content is 99-1 pts.mass to the total 100 pts.mass of (B) component content and (C) component content.

Description

  The present invention relates to an antifogging composition suitable for imparting antifogging properties to a resin sheet such as a styrene resin sheet, an antifogging resin sheet formed using the same, and a container formed using the same. .

Food packaging containers such as lunch boxes are used to wrap contents that contain moisture, to store refrigerated, or to heat in a microwave oven, so that water vapor adheres to the surface of the lid as fine water droplets and the transparent lid becomes cloudy. May end up. In particular, in the case of a styrene resin sheet or the like, since the sheet surface is hydrophobic, the water adhering to the sheet surface easily forms water droplets, thereby causing fogging by diffusion, refraction, and reflection of light.
However, if the lid is cloudy, the contents will not look delicious, which may lead to a decrease in sales such as lunch boxes. For this reason, it has been an important issue to prevent the lid material from becoming cloudy in this type of container.

In the past, as a technique for imparting antifogging properties, water droplets were wetted and spread by the action of a surfactant to ensure transparency. However, since the surfactant is easily soluble in water, there is a problem that the surfactant is lost together with water and the antifogging property is lowered.
Therefore, an antifogging agent obtained by adding a surfactant to a hydrophilic polymer such as polyether polyol has come to be used. The film formed by blending the hydrophilic polymer not only becomes hard and strong, but the film that has become hydrophilic exhibits anti-fogging properties by absorbing moisture, even when the moisture absorption saturation point is reached, The water droplets get wet and spread by the action of the surfactant, thereby ensuring transparency. However, since hydrophilic polymers are also easily eluted in water, there has been a problem that the anti-fogging effect is reduced when exposed to water vapor for a long time.

Here, the conventionally proposed antifogging composition is introduced.
Patent Document 1 includes, as a main component, a mixture of (1) an aqueous solution or emulsion of a resin, (2) a wax emulsion, and (3) an antifogging agent, and (1) a solid content and (2) a solid content. Is a mass ratio of 98: 2 to 50:50, and the mass ratio of the total mass of the solid content of (1) and the solid content of (2) to (3) is 98: 2 to 50:50. A composition for surface coating is disclosed.

  Patent Document 2 discloses a surface treatment agent containing a sucrose fatty acid ester, a silicone emulsion, a polysaccharide and / or a hydrophilic polymer (excluding polyvinyl alcohol). An antifogging composition comprising a mixture of an alcohol type nonionic surfactant and a polyethylene glycol type nonionic surfactant is disclosed.

  Further, Patent Document 4 discloses (A) a nonionic surfactant (such as sucrose fatty acid ester), (B) a water-soluble polymer (such as vinylpyrrolidone polymer), and (C) an anionic surfactant ( And antifogging surface treatment agents composed of sulfonates and the like.

  By the way, when the antifogging composition is applied to one surface of the resin sheet, dried and wound up in a roll shape, the resin sheet is taken out from the roll and molded into a container by thermoforming. Accordingly, the anti-fogging composition is transferred in contact with the non-fogging treated surface of the resin sheet, or the anti-fogging agent is transferred in contact with a heating body such as a hot plate in the container molding process. Or, there were problems such as sticking to the mold and worsening of the mold. Then, in order to improve the mold release property of an antifogging sheet | seat, forming a mold release layer on the opposite side surface of an antifogging layer is performed.

  For example, in Patent Document 5, at least one antifogging agent selected from sucrose fatty acid esters and polyglycerin fatty acid esters is applied to one surface, and ether-based multimers (polyoxyethylene-polyoxy) are applied to the other surface. A polystyrene sheet coated with a release agent composed of a propylene block copolymer) is disclosed.

JP-A-1-69688 Japanese Patent No. 3241797 JP 2003-201355 A JP 2010-37387 A JP 2002-46232 A

  The conventionally proposed anti-fogging composition has insufficient transparency when forming the anti-fogging layer, or has a sticky feeling, for example, when it is continuously exposed to a large amount of water vapor at a high temperature, etc. Cannot be fully exhibited, or it is easy to transfer to the release agent on the back side.

  Therefore, the present invention has sufficient transparency when forming the anti-fogging layer, has less stickiness when pressed with a finger, and is exposed to a large amount of water vapor at a high temperature. New anti-fogging feature that prevents fogging even when exposed to exposure, has anti-fogging durability that prevents liquid film and water droplets from adhering, and is difficult to transfer to the release agent on the back side. It is intended to provide a sex composition.

  In order to achieve the above object, the present invention provides an antifogging composition comprising (A) a surfactant, (B) a hydrophilic polymer, and (C) a shellac component, wherein (A) As a component, it contains a nonionic surfactant and an anionic surfactant, and the total content of (A) component, (B) component, and (C) component is 100 parts by mass, The content is 50 to 99 parts by mass, the total content of the component (B) and the component (C) is 50 to 1 part by mass, and the total amount of the component (B) and the component (C) is 100 parts by mass. The content of the component (B) is 1 to 99 parts by mass, and the content of the component (C) is 99 to 1 part by mass, which proposes an antifogging composition. .

By forming (C) shellac in (A) surfactant and (B) hydrophilic polymer to form an antifogging film, it is possible to suppress the sticky feeling when pressed with a finger and pulled apart. Furthermore, by forming a film by adding hydrophobic shellac, the hydrophobicity of the entire film can be increased, so that the surfactant and hydrophilic polymer can be prevented from eluting into water, for example, Even if it continues to be exposed to a large amount of water vapor at a high temperature, or conversely, even if it is exposed to a low temperature environment, it can form a durable antifogging layer that does not cause fogging and does not cause liquid film or water droplets to adhere. it can.
In addition, due to the effect of film formation by shellac, it is possible to suppress accumulation of dirt on the surface of the hot plate when carrying out hot plate molding, such as mixing and transfer of antifogging agent and release agent during storage in roll form. Can be effectively suppressed. And since such a transfer can be suppressed, the performance of transparency and anti-fogging property is hardly lowered.
In addition, (A) a surfactant and (B) a hydrophilic polymer containing (C) shellac in a compounding composition, the content of each component is in a specific range, and an anionic surfactant and a nonionic surfactant By using the agent in combination, excellent surface active antifogging properties can be exhibited while maintaining the appearance of the antifogging layer satisfactorily.
Furthermore, by increasing the content ratio of (B) hydrophilic polymer to the content ratio of (C) shellac, it exhibits excellent antifogging properties and excellent antifogging even if it continues to be exposed to a large amount of water vapor. Sustainable.

  Next, the present invention will be described based on exemplary embodiments, but the present invention is not limited to the embodiments described below.

<This antifogging composition>
An antifogging composition according to an example of an embodiment of the present invention (referred to as “the present antifogging composition”) contains (A) a surfactant, (B) a hydrophilic polymer, and (C) shellac. It is an antifogging composition.

(A) Surfactant It is important to use a nonionic surfactant and an anionic surfactant in combination as the surfactant used in the antifogging composition.
If only an anionic surfactant is used, the surface activity is too strong, resulting in coating unevenness and the appearance is reduced. On the other hand, if only a nonionic surfactant is used, the surface activity is weak and moisture is made to conform to the surface. It becomes less effective. On the other hand, by using both in combination, it is possible to exhibit excellent surface activity while maintaining the appearance of the antifogging layer well, and also in terms of its sustainability (antifogging sustainability). can do.

  Nonionic surfactants include, for example, glycerin fatty acid ester, polyglycerin fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid ester, fatty acid alkanolamide, polyethylene glycol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene sorbitan fatty acid ester, poly Examples thereof include oxyethylene fatty acid amide, polyoxyethylene (cured) castor oil ether, polyoxyethylene polyoxypropylene block copolymer, and the like, and one or more of these can be used.

Among these, polyglycerin fatty acid ester, sucrose fatty acid ester, and polyoxyethylene polyoxypropylene block copolymer are particularly preferable from the viewpoint of expressing good antifogging properties.
Here, the polyglycerin fatty acid ester is an ester of polyglycerin and a fatty acid, and the fatty acid constituting the polyglycerin fatty acid ester is preferably an ester of a fatty acid having 6 to 22 carbon atoms, and having 8 to 18 carbon atoms. Fatty acid esters are more preferable, fatty acid esters having 10 to 16 carbon atoms are particularly preferable, and lauric acid esters having 12 carbon atoms are more preferable. The number of glycerin bonds is preferably 2-20, more preferably 2-6, and among them, the number of glycerin bonds is 2, that is, diglycerin is more preferred. Of these, diglycerin laurate is most preferred.
The sucrose fatty acid ester is an ester of sucrose and a fatty acid. The fatty acid constituting the sucrose fatty acid ester is preferably an ester of a fatty acid having 6 to 22 carbon atoms, and an ester of a fatty acid having 8 to 18 carbon atoms. More preferably, an ester of a fatty acid having 10 to 16 carbon atoms is particularly preferred, and a lauric acid ester having 12 carbon atoms is further preferred. Sucrose laurate having an HLB of 12 to 17 is most preferable.
As the polyoxyethylene polyoxypropylene block copolymer, the content of ethylene oxide chain is more preferably 10 to 90%, and the content of ethylene oxide chain is particularly preferably 10 to 50%.

  On the other hand, examples of the anionic surfactant include carboxylate such as fatty acid salt and polyoxyethylene alkyl ether carboxylate, sulfate ester salt such as alkyl sulfate ester salt and polyoxyethylene alkyl ether sulfate ester, and alkylbenzene sulfonic acid. Examples thereof include sulfonic acid salts such as salts and alkylsulfosuccinates, phosphoric acid ester salts such as alkyl phosphoric acid ester salts and polyoxyethylene alkyl ether phosphoric acid ester salts, and one or more of these may be used. it can.

Especially, it is especially preferable that it is 1 type, or 2 or more types selected from the group which consists of alkyl sulfate ester salt, alkyl sulfosuccinate, and fatty acid salt from the point which expresses favorable antifogging property. Here, the alkyl sulfate ester salt is more preferably an alkyl sulfate ester salt having 8 to 18 carbon atoms, and particularly preferably an alkyl sulfate ester salt having 8 to 18 carbon atoms composed of a sodium salt or a potassium salt.
As the alkylsulfosuccinate, an alkylsulfosuccinate having 8 to 18 carbon atoms is more preferable, and an alkylsulfosuccinate having 8 to 18 carbon atoms composed of a sodium salt or a potassium salt is particularly preferable.
As the fatty acid salt, a fatty acid salt having 8 to 18 carbon atoms is more preferable, and a fatty acid salt having 8 to 18 carbon atoms composed of a sodium salt or a potassium salt is particularly preferable.

  The present antifogging composition may contain other surfactants as long as it contains a nonionic surfactant and an anionic surfactant as the main component of the surfactant. For example, it may contain a cationic surfactant such as an alkyl ammonium salt or an alkyl pyridinium salt, or an amphoteric surfactant such as an alkylaminoacetic acid betaine, an alkylamidopropyl betaine or an alkylsulfobetaine.

(B) Hydrophilic polymer Examples of the hydrophilic polymer used in the antifogging composition include a hydrophilic acrylic copolymer, polyvinyl alcohol (saponified polyvinyl acetate), polyvinylpyrrolidone, polyethylene oxide, and polyethylene glycol. , Celluloses, polysaccharides and the like. One of these can be used, or two or more of these can be selected and used in combination.

  Among these, it is preferable to use a hydrophilic acrylic copolymer or polyethylene oxide, among these, from the viewpoint of improving transfer suppression and coating hardness of a good antifogging layer.

  The hydrophilic acrylic copolymer only needs to contain a structural repeating unit derived from an acrylic monomer having a hydrophilic group, and the acrylic monomer having no structural repeating unit and a hydrophilic group. The copolymer is preferably composed of a constitutional repeating unit derived from the body.

The above-mentioned “acrylic monomer having a hydrophilic group” is a hydrophilic group that is a polar atomic group having a strong interaction with water, that is, a cationic group that dissociates as a cation in water, and dissociates as an anion. Examples thereof include known acrylic monomers having an anionic group or a nonionic group that does not dissociate.
Examples of the acrylic monomer having a cationic group include dimethylaminoethyl (meth) acrylate and salts thereof, ethyl trimethylammonium chloride (meth) acrylate, 2-hydroxy-3- (meth) acryloyloxy. Examples of acrylic monomers having an anionic group such as propyltrimethylammonium chloride include (meth) acrylic acid and its salt, (meth) acrylic acid-2-sulfoethyl and its salt, hydroxyethyl ( Examples of acrylic monomers having a non-ionic group such as (meth) acryloyl phosphate and salts thereof include hydroxyalkyl (meth) acrylate, polyethylene glycol (meth) acrylate, and methoxypolyethylene glycol (meth) acrylate Cite It is possible.
Here, “(meth) acryl” means “acryl” and / or “methacryl”.
Examples of the “salt” include alkali metal, alkaline earth metal, and aluminum group metals, preferably salts of Li, Na, K, Mg, Ca, and Al, and ammonium salts.
As these hydrophilic acrylic copolymers, an acrylic monomer having an anionic group and an acrylic monomer having a nonionic group are preferable from the viewpoint of suppressing transfer of the antifogging layer, and the anionic group is preferred. (Meth) acrylic acid and salts thereof are more preferable as the acrylic monomer having, and hydroxyalkyl (meth) acrylate is more preferable as the acrylic monomer having a nonionic group.

  On the other hand, as the above-mentioned “acrylic monomer having no hydrophilic group”, for example, alkyl (meth) acrylate (linear and branched having 1 to 8 carbon atoms) ester, cyclohexyl (meth) acrylate, Examples include glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl acrylate, (meth) acrylonitrile, and the like, among these acrylic monomers having no hydrophilic group, (Meth) acrylic acid alkyl ester and (meth) acrylonitrile are preferred, and (meth) acrylic acid alkyl ester is more preferred.

  Among the above hydrophilic acrylic copolymers, in the present antifogging composition, a structural repeating unit derived from a metal salt of (meth) acrylic acid and a structural repetition derived from a (meth) acrylic acid alkyl ester Copolymers containing units are particularly preferred.

The hydrophilic acrylic copolymer used as the hydrophilic polymer may further contain a constitutional repeating unit derived from a crosslinkable acrylic monomer as long as the copolymer does not gel. The water resistance and hardness of the antifogging layer can be improved.
Examples of the crosslinkable acrylic monomer include N, N′-methylenebis (meth) acrylamide, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and 1,4-butanediol di (meth). Examples thereof include acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane poly (meth) acrylate, and pentaerythritol poly (meth) acrylate.

On the other hand, as the polyethylene oxide, the viscosity average molecular weight Mv measured by the method shown below is preferably 50,000 to 8 million, more preferably 70,000 to 6 million, and 90,000 to 4 million. Is particularly preferred.
When the viscosity average molecular weight of the polyethylene oxide is less than the above range, the antifogging sustainability which is considered to be caused by the adhesion between the antifogging layer and the resin sheet tends to decrease, and when the above range is exceeded, the antifogging layer is excessive. As a result, there is a tendency for transparency to decrease.

The “viscosity average molecular weight Mv” as used herein is the F.E. E. Bailey Jr. etal. , J .; Polym. Sci. , 32, 517 (1958), and calculated from the intrinsic viscosity [η] measured at a temperature of 30 ° C. for a polyethylene oxide aqueous solution.
[Η] = 1.25 × 10 ⁻⁴ × Mv ^0.78

(C) Shellac Shellac (cerac) used in the anti-fogging composition is obtained by purifying a resinous substance secreted by the silkworm, and white shellac that has been bleached is commercially available.
Specific examples include purified shellac, decolorized shellac, and white shellac obtained from naturally occurring resinous materials.
Among these, decolorized shellac or white shellac is preferable from the viewpoint of exhibiting good antifogging durability and transparency of the antifogging layer.
Further, although the chemical structure of shellac is not completely elucidated, the main component is a polyester comprising at least aleuritic acid, shellolic acid and its derivatives as constituents, and these are the present invention. It is presumed that this is the reason for exhibiting preferable characteristics. In addition, the presence of butoleic acid, palmitic acid, myristic acid, etc. has been confirmed. Therefore, the “shellac” of the present invention includes not only shellac derived from nature but also chemically synthesized resins synthesized based on the above estimated structure and exhibiting the same effects as described above.

(Combination)
Concerning the composition of the present antifogging composition, the content of the component (A), the component (B) and the component (C) is the content of the component (A) with respect to 100 parts by mass of the total amount of the three components. The amount is preferably 50 to 99 parts by mass, more preferably 55 to 95 parts by mass, and most preferably 55 to 90 parts by mass.
The total content of component (B) and component (C) is preferably 50 to 1 part by mass, more preferably 45 to 5 parts by mass, and particularly preferably 45 to 10 parts by mass. preferable.
When the component (A) is less than the above range and the total amount of the component (B) and the component (C) exceeds the range, the antifogging property tends to be insufficient, while the component (A) is the above. If the total amount of the component (B) and the component (C) is less than the above range when the range is exceeded, mixing and transfer between the antifogging layer and the release layer tend not to be sufficiently suppressed.

Moreover, it is preferable that content of (B) component is 1-99 mass parts with respect to 100 mass parts of total amounts of (B) component and (C) component, especially 15-90 mass parts, and 25-25 among them. More preferably, it is 85 parts by mass.
On the other hand, the content of the component (C) is preferably 99 to 1 part by mass, more preferably 85 to 10 parts by mass, and most preferably 75 to 15 parts by mass.
When the component (B) is less than the above range and the component (C) exceeds the above range, the antifogging property itself in a low temperature environment tends to be insufficient, and the component (B) exceeds the above range, (C If the component is less than the above range, the antifogging property itself tends to be insufficient when exposed to a large amount of water vapor at a high temperature.
The combined content of the component (A), the component (B) and the component (D) in the antifogging agent composition (not including the solvent) is preferably 50 to 100% by mass.

<This antifogging resin sheet>
An antifogging resin sheet (referred to as “the present antifogging resin sheet”) according to an example of an embodiment of the present invention is formed on at least one side of a base sheet from the above antifogging composition. It is a sheet | seat provided with the layer, Comprising: You may form a release layer in the opposite side to an anti-fogging layer as needed.

(Base material sheet)
As a base material sheet, if it is a transparent resin sheet, it can use suitably. For example, a thermoplastic resin such as a polystyrene resin, an amorphous polyethylene terephthalate (hereinafter sometimes abbreviated as “A-PET”), a polyester resin, a polypropylene resin, a polylactic acid resin, a polyvinyl chloride resin, etc. , Unstretched sheets, uniaxial or biaxially stretched sheets, and the like. Among these, a biaxially stretched polystyrene sheet and an unstretched A-PET sheet are preferable.
The thickness of the substrate sheet is not particularly limited, but is preferably 0.1 mm to 0.7 mm.

  For the base sheet, the surface of the resin sheet is usually adjusted to a surface tension of preferably 50 to 60 mN / m by using a known surface treatment method, for example, by corona discharge treatment, or a high frequency treatment, if necessary. Those subjected to the treatment are preferable.

(Anti-fog layer)
The thickness of the antifogging layer is not particularly limited, but is preferably 5 nm to 1000 nm, more preferably 10 nm or more or 500 nm or less, and particularly preferably 20 nm or more or 200 nm or less. .
Further, the coating amount of the antifogging agent in the antifogging layer is not particularly limited, but is preferably ⁵ to 1000 mg / m ^{2, and} more preferably 10 mg / m ² or more or 500 mg / m ² or less. More preferably, it is particularly preferably 20 mg / m ² or more or 200 mg / m ² or less. If the coating amount of the antifogging layer in the antifogging layer is less than the above range, the antifogging property itself may be insufficient. On the other hand, if it exceeds the above range, the sheet may be whitened and the appearance may be deteriorated.

(Release layer)
The anti-fogging resin sheet may have an anti-fogging layer on both sides of the base sheet, but on the other side, such as mold releasability from the mold during molding and releasability between the molded bodies. A release layer can be formed for application.

The release layer can be formed from, for example, silicone oil.
Examples of the silicone oil include methyl hydrogen polysiloxane, dimethyl polysiloxane, methylphenyl polysiloxane, and polyoxyalkylene (carbon number 2 to 4) modified dimethyl polysiloxane.
Among these, dimethylpolysiloxane and polyoxyethylene polyoxypropylene-modified dimethylpolysiloxane are more preferable, and dimethylpolysiloxane is particularly preferable from the viewpoints of releasability and safety and health.

Silicone oil, a viscosity at 25 ° C., is preferably from 10~100,000mm ² / s, more preferably from 50~50,000mm ² / s, is 100~30,000mm ² / s Is particularly preferred. The silicone oils may be used alone or in combination of two or more.

  In the release layer, the above-described surfactant or, if necessary, an anti-blocking agent, an antistatic agent, a viscosity modifier, an antifoaming agent, an ultraviolet absorber, and a colorant, as long as the effects of the present invention are not impaired. An inhibitor, an antibacterial agent, or a colorant such as a pigment or dye may be added.

The thickness of the release layer is not particularly limited, but is preferably 1 to 100 nm, more preferably 3 nm or more and 70 nm or less, and particularly preferably 5 nm or more or 50 nm or less.
The release agent coating amount of the release layer is not particularly limited, but is preferably 1 to 100 mg / m ^2, and even in inter alia 3 mg / m ² or more, or 70 mg / m ² or less Particularly, it is more preferably 5 mg / m ² or more or 50 mg / m ² or less. If the release agent coating amount of the release layer is less than the above range, the releasability itself may be insufficient. On the other hand, if it exceeds the above range, further improvement of the releasability may not be observed.

  In the present invention, the coating amount of the antifogging layer and the release layer is measured by washing the antifogging agent on the antifogging resin sheet whose area is known, and the release agent, and collecting the washing solution. A mass method, a gas chromatography method, a high-speed chromatography method, etc. can be used, but a calibration curve is created by FT-IR (ATR method) using a sheet with a known coating amount as a standard sample. Since the comparison method is simple, it can also be used.

(Manufacturing method)
Next, although an example of the manufacturing method of this anti-fogging resin sheet is demonstrated, it is not limited to this.

  The antifogging composition is adjusted to a concentration of, for example, 0.1 to 5% by mass using a solvent or a dispersion medium, and is applied to at least one surface of the base sheet, for example, a spray coater, an air knife coater, or a squeeze roll coater. It is preferable to apply a coating amount after drying by a known coating method such as a gravure roll coater, knife coater or the like so that the coating amount becomes the above coating amount, and dry with a hot air dryer or the like to form an antifogging layer.

The coating amount of the antifogging composition is preferably ⁵ to 1,000 mg / m ^2, more preferably 10 mg / m ² or more or 500 mg / m ² or less, particularly 20 mg / m ² or more. More preferably, it is 200 mg / m ² or less. If the coating amount of the antifogging agent forming the antifogging layer is less than the above range, the antifogging property itself tends to be insufficient, whereas if it exceeds the above range, the sheet tends to whiten and the appearance tends to deteriorate.

Next, when a release layer is formed on the other side, a release agent solution adjusted to a concentration of about 0.1 to 5% by mass is applied to the other side in the same manner, and the coating amount after drying is It can apply | coat with the quantity used as the said coating amount, can be dried with a hot air dryer etc., and can form a release layer. The order of forming the antifogging layer and the release layer is arbitrary.
The produced antifogging resin sheet is usually wound into a roll so as to be a wound product so that both layers are polymerized with the antifogging layer on the outside and the release layer on the inside.

<Explanation of words>
In the present specification, when expressed as “X to Y” (X and Y are arbitrary numbers), unless otherwise specified, “X is preferably greater than X” or “preferably Y”. It also includes the meaning of “smaller”.
In addition, when expressed as “X or more” (X is an arbitrary number) or “Y or less” (Y is an arbitrary number), it is “preferably greater than X” or “preferably less than Y”. Includes intentions.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded.

<Raw material>
(A) Surfactant, (B) hydrophilic polymer, (C) shellac, (D) other components, and release layer forming component used for forming the antifogging layer used in the following examples and comparative examples The (E) silicone oil as a component is shown below.

(A) Surfactant A-1; Sucrose laurate (HLB: 15)
A-2: Polyglycerol laurate (HLB: 9)
A-3: polyoxyethylene polyoxypropylene block copolymer (EO hydrophilic group ratio 10%)
A-4; sodium alkyl (C8) sulfate A-5; sodium dialkyl (C8) sulfosuccinate

(B) Hydrophilic polymer B-1; hydrophilic acrylic copolymer (methacrylic acid alkyl ester / acrylic acid alkyl ester / acrylic acid copolymer and its light metal salt (Li, Na, K, Ca, Ng, Al ), Softening point 45 ° C., filtration particle size 5 μm)
B-2: Polyethylene oxide (viscosity average molecular weight 100,000 to 170,000)

(C) Shellac C-1: Ethanol solution of decolorized shellac (decolorized shellac concentration 5 mass%)

(D) Other components D-1: Wax emulsion of polyethylene (polyethylene concentration 30% by mass)

(E) Silicone oil E-1: Emulsion of dimethylpolysiloxane (viscosity 10,000 mm ² / s at 25 ° C.) (dimethylpolysiloxane concentration 30 mass%)

<Examples 1-7, Comparative Examples 1-6>
After subjecting one surface of a biaxially oriented polystyrene sheet (thickness 0.3 mm) to corona treatment, an anti-fogging layer is formed on the corona-treated surface (A) to (D). An aqueous solution of an antifogging composition was prepared using the above A-1 to D-1 so as to have the composition shown, and then applied with a spray coater, and the release agent emulsion of E-1 was applied to the other surface. It was applied with a spray coater, and the coated surface was made uniform with a smoothing roll and dried. Thereafter, the antifogging layer was used as the outside and the release layer was used as the inside, which was wound up in a roll shape to obtain a wound product, and the wound product immediately after winding was rolled back to obtain a resin sheet (sample).
In addition, the contents of (C), (D) and (E) shown in Table 1 are values as the respective solid contents of shellac, polyethylene wax and silicone (the same applies to the following examples and comparative examples). .

The obtained resin sheet (sample) was sampled, and the antifogging agent coating amount of the antifogging layer and the release agent coating amount of the release layer were measured by FT-IR (ATR method), and the results are shown in Table 1. It was.
The coating amount was measured by measuring the ratio between the characteristic absorption around 1730 cm ⁻¹ for the antifogging layer and the characteristic absorption around 1260 cm ⁻¹ for the release layer and the characteristic absorption around 1940 cm ^{−1 for} polystyrene. The composition was determined by comparison with a calibration curve prepared from a sheet having a known agent composition or a release agent composition and each coating amount.
On the other hand, after the wound wound product was stored at room temperature for about 3 months, the stickiness of the rolled sheet, the transparency, and the antifogging property of the thermoformed lid were evaluated by the following method. Are shown in Table 1.

<Examples 8 to 9, Comparative Example 7>
Antifogging composition so that the composition of each component (A) to (D) forming an antifogging layer on one surface of an unstretched A-PET sheet (thickness 0.3 mm) is the composition shown in Table 1. After preparing the aqueous solution of A-1 to D-1 above, it was applied with a spray coater, and the release agent emulsion of E-1 was applied to the other surface with a spray coater, and the coated surface was smoothed with a smoothing roll. Homogenized and dried. Thereafter, the antifogging layer was used as the outside and the release layer was used as the inside, which was wound up in a roll shape to obtain a wound product, and the wound product immediately after winding was rolled back to obtain a resin sheet (sample).

The obtained resin sheet (sample) was sampled, and the antifogging agent coating amount of the antifogging layer and the release agent coating amount of the release layer were measured by FT-IR (ATR method), and the results are shown in Table 1. It was.
The measurement of the amount of coating in the vicinity of 1730 cm ^-1 for antifogging layer, and the characteristic absorption around 1260 cm ^-1 for the release layer, the ratio between the characteristic absorption of A-PET, antifogging agent composition or The release agent composition and each coating amount were quantified by comparison with a calibration curve prepared from a known sheet.
On the other hand, after the wound wound product was stored at room temperature for about 3 months, the stickiness of the rolled sheet, the transparency, and the antifogging property of the thermoformed lid were evaluated by the following method. Are shown in Table 1.

<Evaluation method>
The performance evaluation of the antifogging resin sheets in the following Examples and Comparative Examples was performed according to the following methods and standards. Unless otherwise specified, “◯” and “◎” are the target levels of the present invention.

(Sheetiness of the sheet)
The feeling of stickiness when the anti-fogging layer surface of the resin sheets (samples) obtained in Examples and Comparative Examples was pressed with a finger and pulled apart was evaluated according to the following criteria.

A: Almost no stickiness.
○: Feeling sticky, but at a practically acceptable level.
(Triangle | delta): Stickiness is a little strong and the trace of a fingerprint remains clearly.
X: Stickiness is intense and slimy.

(Sheet transparency)
The haze of the resin sheets (samples) obtained in the examples and comparative examples was determined according to JIS.
In accordance with K7105, the haze meter ("NDH-300A" manufactured by Nippon Denshoku Industries Co., Ltd.) was used (n = 5 average value), and both the haze value and the sheet appearance observed with the naked eye were as follows: Evaluation based on the criteria.

A: Haze less than 1.5 or white unevenness (transfer pattern) is not seen at all.
○: Haze is less than 1.5 to 2 or light white unevenness (transfer pattern) is observed.
Δ: Haze 2 to less than 3 or white unevenness (transfer pattern) is conspicuous.
X: Haze 3 or more, or clear white unevenness (transfer pattern) is observed.

(Low-temperature anti-fogging property as a lid)
A container body (fitting type) having an opening of 180 mm × 120 mm and a depth of 20 mm was thermoformed using a polystyrene sheet having a thickness of 0.3 mm, and 150 cc of water at 23 ° C. was placed in the container body. Next, the resin sheets (samples) obtained in the examples and comparative examples are fitted to the opening of the container body so that the anti-fogging layer is on the inner surface, and the lid is covered, and the showcase at 5 ° C. The sample was allowed to stand inside and visually observed for the occurrence of fogging on the inner surface of the lid and the adhesion of the liquid film and water droplets after 1 hour, and evaluated according to the following criteria.

A: The lid is not cloudy, the liquid film is uniform, and the contents are highly visible.
○: The lid is not cloudy, the liquid film is non-uniform, and some water droplets are attached, but the content is not visible.
Δ: The lid is not cloudy, but the liquid film is non-uniform and considerable water droplet adhesion is observed, causing a problem in the visibility of the contents.
X: Clouding is observed on a part of the lid, or water droplets adhere to almost the entire lid and it is difficult to visually recognize the contents.

  In addition, the above evaluation was evaluated immediately after production as “low temperature antifogging property / initial”, and the wound wound product was stored at room temperature for about 3 months and then rolled back in the same manner as described above. Evaluation was made as “low temperature anti-fogging property / after 3 months”.

(High temperature anti-fogging property as a lid)
Using a polystyrene sheet having a thickness of 0.3 mm, a container main body (fitting type) having an opening of 180 mm × 120 mm and a depth of 20 mm was thermoformed, and 150 cc of hot water at 80 ° C. was placed in the container main body. Next, the resin sheets (samples) obtained in Examples and Comparative Examples are fitted to the opening of the container body so that the anti-fogging layer is on the inner surface, covered, and kept in a 23 ° C. atmosphere. Then, the occurrence of fogging on the inner surface of the lid body after 1 hour and the adhesion of the liquid film and water droplets were visually observed and evaluated according to the following criteria.

A: The lid is not cloudy, the liquid film is uniform, and the contents are highly visible.
○: The lid is not cloudy, the liquid film is non-uniform, and some water droplets are attached, but the content is not visible.
Δ: The lid is not cloudy, but the liquid film is non-uniform and considerable water droplet adhesion is observed, causing a problem in the visibility of the contents.
X: Clouding is observed on a part of the lid, or water droplets adhere to almost the entire lid and it is difficult to visually recognize the contents.

  In addition, the above evaluation was evaluated immediately after production as “high temperature anti-fogging property / initial”, and the wound wound product was stored at room temperature for about 3 months and then rolled back in the same manner as described above. Evaluation was made as “high temperature anti-fogging property / after 3 months”.

(Stain on the hot plate surface)
Resin sheets (samples) obtained in Examples and Comparative Examples were continuously molded into a container body (fitting type) using a hot plate molding machine CK-1200 manufactured by Kansai Automatic Molding Machine. The molding conditions were a molding temperature of 135 ° C. and a molding cycle of 10 seconds. Before starting molding, the surface of the hot plate was cleaned with a waste cloth soaked in water, and after 2000 shots of continuous molding, the hot plate surface was wiped and cleaned again with a waste cloth soaked in water. The degree of dirt on the waste was evaluated according to the following criteria.

(Double-circle): The surface of the wiped waste cloth is hardly dirty.
○: The surface of the wiped waste is slightly dirty. (We can barely see the discoloration of the waste.)
Δ: The surface of the wiped waste is dirty. (You can see the discoloration of the waste visually)
X: The surface of the wiped waste was remarkably dirty. (We can easily see the discoloration of the waste.)

(Discussion)
As in Examples 1 to 9, (A) a surfactant and (B) a hydrophilic polymer are blended with (C) shellac to form an antifogging film, thereby forming an antifogging layer with extremely high transparency. It was found that not only can be formed, but also an anti-fogging layer can be obtained which suppresses the sticky feeling when pressed with a finger and pulled apart.
Moreover, like Examples 1-9, (A) surfactant and (B) hydrophilic polymer are blended with (C) shellac to form an anti-fogging film, thereby producing a large amount of water vapor at high temperatures. It has also been found that, even if it continues to be exposed or, conversely, it continues to be exposed to a low temperature environment, it does not generate fog and can form a durable anti-fogging layer. This is because the hydrophobicity of the entire coating can be increased by blending hydrophobic shellac to form a coating, so that the surfactant and the hydrophilic polymer can be prevented from eluting into water. It is thought that.

  Further, as in Examples 1 to 9, hot plate molding is performed by blending (C) shellac with (A) surfactant and (B) hydrophilic polymer to form an antifogging film. It was also found that the accumulation of dirt on the hot plate surface can be suppressed. Similarly, it has also been confirmed that mixing and transfer of an antifogging agent and a release agent can be effectively suppressed during storage in a roll form.

Furthermore, (A) Surfactant and (B) In the compounding composition which consists of (C) shellac in hydrophilic polymer, (A) component 50-99 mass parts with respect to 100 mass parts of total amounts of the said 3 components. , (B) component and (C) component total amount 50-1 part by mass, and (B) component and (C) component total amount 100 parts by mass with respect to (B) component 1-99 parts by mass In addition, by using 99 to 1 part by mass of component (C) and using an anionic surfactant and a nonionic surfactant in combination, it is possible to exhibit excellent surface activity while maintaining a good appearance of the antifogging layer. I understood.
On the other hand, Comparative Example 4 in which the content of the component (A) is less than 50 parts by mass was poor in both low temperature and high temperature antifogging properties after long-term storage. Further, Comparative Examples 5 and 7 using only the nonionic surfactant as the component (A) have poor low-temperature and high-temperature antifogging properties after long-term storage, and Comparative Example 6 using only the anionic surfactant is The high temperature anti-fogging property after long-term storage was poor.

Claims (8)

An antifogging composition comprising (A) a surfactant, (B) a hydrophilic polymer, and (C) a shellac component,
As component (A), a nonionic surfactant and an anionic surfactant are contained, and (A) component, (B) component, and (C) component, ) Component content is 50 to 99 parts by mass, the total content of component (B) and component (C) is 50 to 1 part by mass, and the total amount of component (B) and component (C) Content of (B) component is 1-99 mass parts with respect to 100 mass parts, Content of (C) component is 99-1 mass part, The antifogging composition characterized by the above-mentioned.   The antifogging composition according to claim 1, wherein the component (B) is a hydrophilic acrylic copolymer, polyethylene oxide, or a mixture thereof.   The nonionic surfactant is one or more selected from the group consisting of sucrose fatty acid ester, polyglycerin fatty acid ester, polyoxyethylene polyoxypropylene block copolymer, and the like. 3. The antifogging composition according to 1 or 2.   The anionic surfactant is one type or two or more types selected from the group consisting of alkyl sulfate ester salts, alkyl sulfosuccinates, and fatty acid salts. Antifogging composition.   (B) Content of component is more than content of (C) component, Antifogging composition in any one of Claims 1-4 characterized by the above-mentioned.   An antifogging resin sheet comprising an antifogging layer formed from the antifogging composition according to claim 1 on at least one surface of the transparent resin sheet.   The antifogging resin sheet according to claim 6, further comprising a release layer on at least one surface of the transparent resin sheet and on the surface opposite to the antifogging layer.   A container formed from the antifogging resin sheet according to claim 6 or 7.