KR20210157981A - Coated Materials, and Films, Sheets and the Like for Packing Foods Using Them - Google Patents

Abstract

The present invention provides a novel coating material replacing conventional paper materials, and at the same time, provides a film or sheet for food packaging that has oxygen barrier properties and is free from concerns regarding endocrine disruptors as well as a transparent food container that has the oxygen barrier properties and can be used as a container for food cooked in a microwave oven at a high temperature exceeding 200℃. More specifically, the present invention provides a coating material comprising: a paper material or a fiber material; and a polymer film provided on at least one side of the paper material or fiber material and having an alkoxysilane structure as a main structure, a film or sheet for food packaging made of the coating material, and a food container.

Description

Coated Materials, and Films, Sheets and the Like for Packing Foods Using Them

The present invention provides a polymer film having a polysiloxane structure as the main structure on at least one surface thereof using a paper material such as cellophane paper, Japanese paper, or parchment paper, or a fiber material such as a non-woven fabric or cloth as a base material, the insulation effect and water repellency are abundant, It relates to a coating material having adequate strength and good light transmittance, and is also rich in flame retardancy. In addition, the present invention is based on the above-described paper material or fiber material, at least one surface of which is provided with a polymer film having a polysiloxane structure as the main structure, it is rich in insulation effect and water repellency, has adequate strength and good light transmittance, It also relates to a film or sheet for food packaging that is rich in flame retardancy, or a container for food.

In addition, the present invention is produced by molding the film or sheet for food packaging, is rich in insulation effect and water repellency, has appropriate strength and good light transmittance, and is also rich in flame retardancy, liquid crystal surface protective cover for electronic devices, clear holder Or it relates to a transparent stationery article such as a film case, a transparent perfume container, and a water-repellent sheet on the surface of a car side mirror.

A paper material on which a paper surface is laminated or coated with a resin has been conventionally used in various fields. To exemplify some that are widely used for residential buildings, for example, rayon or polypropylene is mixed in a predetermined ratio for a long door as a partition for opening and closing a Japanese-style room, and a plastic film is laminated on the rayon paper and rayon paper. The processed long-fingerprint paper and the long-printed paper obtained by laminating an acrylic material or a vinyl chloride material on the surface of Japanese paper are used.

In addition to paper, as a sheet material, a plastic sheet or a vinyl sheet, etc. generally have high light transmittance and are known to be excellent in water repellency.

In addition, as a film or sheet for food packaging, polyvinylidene chloride (PVDC) has been widely used in the past because of its excellent oxygen barrier properties.

As the food container, for example, expanded polystyrene was used for a container such as cup noodles, and for example, a stretched transparent polypropylene resin container was used for a food container for microwave cooking.

Since conventional paper materials do not have light transmittance except for paraffin paper or cellophane paper, there is a problem in that they cannot be used for products requiring light transmittance. Moreover, conventional paper materials usually have high hygroscopicity and are not sufficient in terms of strength.

Although the above-mentioned rayon long-fingerprint paper and the like can solve these problems to some extent, on the other hand, there is a new problem that dust tends to adhere because it is easy to generate static electricity. Moreover, although the material itself is relatively strong against water, there is also a problem in that the adhesive surface is easily peeled off by inhaling moisture when cleaning with a wet rag or the like.

Although the above-mentioned plastic sheet or vinyl sheet can exhibit high light transmittance and excellent water repellency compared to paper, their manufacture is by factory production, and the texture, etc. It is very difficult to replace a new item with this. Furthermore, in addition to the above problems, in plastic sheets or vinyl sheets, etc., there is a fear that substances or dioxins that act as environmental hormones or the like may be generated when they are incinerated due to various additive substances contained therein.

On the other hand, since the conventional food packaging film or sheet uses PVDC, due to chlorine atoms contained therein, there is a risk of generating substances or dioxins acting as so-called environmental hormones when incinerated. In particular, it is suspected that a plasticizer added to improve processability acts as an environmental hormone.

In addition, there is concern about the elution of styrene dimer, etc., which is suspected as an environmental hormone even in expanded polystyrene used as a container for cup noodles or a polypropylene resin used as a food container for microwave cooking. In particular, for a food container for microwave cooking, since such food can be cooked at a high temperature exceeding 200 ° C, a food container that can be cooked at a higher temperature instead of a polypropylene resin having a melting point of about 160 ° C. is desired

In this way, a new paper material for constituting a personal product is desired, and an environmentally friendly material is desired for such a paper material, a film for food packaging, and a food container in view of the recent strictness with respect to the global environment.

Therefore, in view of the problems of conventional paper materials as described above, the first object of the present invention is to use a paper material such as cellophane paper, Japanese paper or brisket with excellent texture, or a fiber material such as a nonwoven fabric or cloth as a base material. It is to provide a coating material that is rich in insulation effect and water repellency, has adequate strength and good light transmittance, and is also rich in flame retardancy.

In addition, the second object of the present invention is to use the above-described coating material, etc., to have rich insulation effect and water repellency, have adequate strength and good light transmittance, have good flame retardancy, have oxygen barrier properties, and at the same time be concerned about environmental hormones. To provide a film or sheet for packaging food without

In addition, a third object of the present invention is a transparent food container that can be used as a container for food that has oxygen barrier properties and is free from environmental hormones, particularly, food cooked at a high temperature exceeding 200° C. in a microwave oven. is to provide

And, a fourth object of the present invention is to use the film or sheet for food packaging, transparent stationery products such as liquid crystal surface protection covers or clear holders of electronic devices, film cases, transparent air freshener containers, and water-repellent sheets for car side mirrors, etc. will provide

The present invention first achieves the first object by providing a coating material having the following configurations (1) to (5).

The coating material of the present invention, in which a polymer film having a polysiloxane structure as the main structure is formed on the surface, is rich in insulation effect and water repellency, has appropriate strength and good light transmittance, and is also rich in flame retardancy, and on the other hand, it would have been incinerated In this case, it is a new material that is friendly to the global environment without the occurrence of dioxins or concerns about environmental hormones.

This material is useful not only as a substitute material for conventional paper or fiber materials, but also has oxygen barrier properties, so it is suitable as a film or sheet for food packaging.

The film or sheet for food packaging in which a polymer film having an alkoxysilane structure as a main structure or a polymer film having a polysiloxane structure as a main structure is formed on the surface of the present invention has oxygen barrier properties. Therefore, the contained food does not oxidize, grow aerobic bacteria, or spoil. In addition, it can stop the occurrence of mold. In addition, there is no concern about the occurrence of dioxins or environmental hormones, so it is friendly to the global environment.

In addition, the container for food of the present invention can be used as a container for food cooked at a high temperature exceeding 200° C. in a microwave oven, and is transparent. Even in this case, it is friendly to the global environment without the occurrence of dioxins or concerns about environmental hormones.

In addition, even if it is used as a liquid crystal surface protective cover for electronic devices, it is environmentally friendly without the generation of dioxins or concerns about environmental hormones in the disposal after use.

(1) A coating material comprising a paper material or a fiber material and a polymer film mainly having a polysiloxane structure provided on at least one side of the material.

(2) The coating material, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from a coating solution containing an alkoxysilane represented by the following formula (1).

(Wherein, R1, R2, R3, and R4 may be the same as or different from each other, and are hydrogen or an alkyl group having 1 to 4 carbon atoms, and n is 2 to 8.)

(3) the polymer film having the polysiloxane structure as the main structure is represented by Chemical Formula 1 and the following Chemical Formula 2, 3 of the 4 substituents are hydrolyzable substituents, and the remaining 1 is an alkoxysilane composed of non-hydrolyzable substituents The coating material, which is a polymer film formed from the coating solution containing it.

(Wherein, R5, R6, and R7 may be the same or different from each other, and are hydrogen, an alkyl group having 1 to 10 carbon atoms or an alkenyl group, or R5O, R6O, R7O represents a siloxane bond, and R8 is an epoxy group in its molecule or It is an alkyl group, an alkenyl group, or a phenyl group that may include a glycidyl group.)

(4) The coating material, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from the coating solution by a catalyst containing a hydrolyzable organometallic compound.

(5) The coating material wherein the hydrolyzable organometallic compound is an organometallic compound containing titanium, zircon, aluminum or tin.

The present invention then achieves the second object by providing a film or sheet for food having the following structures (6) to (12).

(6) A film or sheet for packaging food comprising a paper material or a fiber material and a polymer film having a polysiloxane structure as a main structure provided on at least one side of the material.

(7) The film or sheet for food packaging, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from a coating solution containing an alkoxysilane represented by the following formula (3).

Formula 3

R9XSi(OR10)4-X

(Wherein, R9 and R10 may be the same or different from each other, and represent a hydrogen atom, an alkyl group, an aryl group, an alkenyl group, or a substituent thereof, and X is an integer of 0 to 2.)

(8) The film or sheet for food packaging, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from a coating solution containing an alkoxysilane represented by the formula (1).

(9) the polymer film having the polysiloxane structure as the main structure contains the alkoxysilane represented by Formula 1 and the alkoxysilane represented by Formula 2, 3 of the 4 substituents are hydrolyzable substituents, and the other 1 is The film or sheet for food packaging, which is a polymer film formed from the coating solution containing an alkoxysilane composed of a non-hydrolyzable substituent.

(10) The film or sheet for food packaging, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from the coating solution by a catalyst containing a hydrolyzable organometallic compound.

(11) The film or sheet for food packaging, wherein the hydrolyzable organometallic compound is an organometallic compound containing titanium, zircon, aluminum or tin.

The present invention then achieves the third object by providing a food container having the following structures (12) to (17).

(12) A food container comprising a paper material or a fiber material and a polymer film having a polysiloxane structure as a main structure provided on at least one side of the material.

(13) The food container, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from a coating solution containing an alkoxysilane represented by the formula (3).

(14) A food container, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from a coating solution containing an alkoxysilane represented by the formula (1).

(15) wherein the polymer film having the polysiloxane structure as the main structure is represented by the above formula (2), three of the four substituents are hydrolyzable substituents, and the other one is a non-hydrolyzable substituent. The coating solution containing an alkoxysilane The food container, which is a polymer film formed from

(16) The food container, wherein the polymer film having the polysiloxane structure as a main structure is a polymer film formed from the coating solution by a catalyst containing a hydrolyzable organometallic compound.

(17) The container for food, wherein the hydrolyzable organometallic compound is an organometallic compound comprising titanium, zircon, aluminum or tin.

And, the present invention achieves the fourth object by processing the film or sheet for food packaging as follows (18) or (19).

(18) The film or sheet for food packaging is cut to a predetermined size and used as a liquid crystal surface protective cover of an electronic device.

(19) The film or sheet for food packaging is cut into a predetermined size by cutting the film or sheet of a predetermined thickness into a bag shape, and is used as a clear holder, transparent stationery products such as a film case, a transparent air freshener container, or a water-repellent sheet on the surface of a car side mirror.

Hereinafter, the present invention will be described in detail.

First, the coating material provided in the present invention to achieve the first object will be described.

The coating material of the present invention, which is based on a paper material such as cellophane paper, Japanese paper or Japanese paper, or a fiber material such as a nonwoven fabric or cloth, solves the problem of surface coating using the so-called sol-gel method used in the conventional substrate coating technology. . The sol-gel liquid used in coating using such a so-called sol-gel method is generally tetraalkoxysilane as a main ingredient, and an organic substituent is used for the purpose of imparting water repellency thereto.

In this case, since tetraalkoxysilane as the main agent has strong inorganic properties, a so-called silane coupling agent typified by phenylalkoxysilane is often used for the purpose of introducing an organic substituent in order to achieve the above object.

However, the so-called silane coupling agent is expensive, and if a certain amount is not used, it is difficult to obtain the above effect. fast), a non-uniform reaction tends to occur, and thus the strength of the obtained coating film (polymer film) is significantly reduced.

In order to compensate for this drawback, a so-called organic/inorganic composite material in which an organic substituent is directly introduced into a silicon atom is synthesized and used in some cases. By using this, the above object can be sufficiently achieved, but the organic/inorganic composite material is difficult to synthesize and therefore becomes expensive. The coating material of the present invention is a novel coating material completed by the applicant's intensive examination, which supplements the drawbacks of the prior art as described above.

The coating material of the present invention is characterized in that a polymer film having a polysiloxane structure as the main structure is formed on at least one side of a paper material such as Japanese paper or parchment paper, or a fiber material such as a nonwoven fabric or cloth. More specifically, the above-mentioned material is coated with an alkoxysilane-based coating solution with or without a predetermined pretreatment, cured and solidified by the action of a catalyst, and the applied material has an insulating effect, water repellency, appropriate strength, and good light. It is to impart permeability and flame retardancy.

The alkoxysilane, which is the main component of the alkoxysilane-based coating solution, may be exemplified by a compound represented by Formula 1 (wherein, R1, R2, R3, R4 may be the same or different from each other, and hydrogen or an alkyl group having 1 to 4 carbon atoms) and n is 2 to 8).

Such an alkoxysilane can be easily obtained by condensing a monomer (eg, methyltrimethoxysilane). As a raw material for the alkoxysilane-based coating solution, a monomer such as the above-described methyltrimethoxysilane may be used as it is, but in this case, Since it takes time to polymerize, it is preferable to use a condensate obtained by condensing a monomer in order to obtain a polymer film having the above characteristics in a short time. However, if the degree of polymerization is too large, the number of alkoxy groups for polymerization on a substrate such as paper at the time of application is insufficient, so that the strength of the polymer film to be formed is likely to be insufficient. Since it has a non-hydrolyzable substituent R4 in its molecule, R4 remains in the resulting coating film. This R4 has sufficient organic properties, and also provides the polymer film with sufficient insulating effect, water repellency, appropriate strength and good light transmittance.

Therefore, in order to properly impart an insulating effect, water repellency, appropriate strength, good light transmittance and flame retardancy, it is particularly preferable to use those having a polymerization degree of 2 to 8. Compared with tetraalkoxysilane, which is inexpensive but cannot be used as it is because of its strong inorganic properties, the monomer used as a raw material for the above-mentioned condensate and it can be easily purchased to the same extent as tetraalkoxysilane. As described above, in the present invention, it is possible to obtain a polymer film having sufficient organic properties, sufficient insulating effect, water repellency, appropriate strength, good light transmittance and flame retardancy, without using an expensive so-called silane coupling agent in combination.

For the purpose of further increasing the organic properties of the polymer film formed by application of the coating solution, alkoxysilane, which is a main component, and various other alkoxysilanes may be added to the coating solution. As the alkoxysilane added for this purpose, in Formula 2 (wherein, R5, R6, and R7 may be the same or different from each other, and are hydrogen, an alkyl group having 1 to 10 carbon atoms, or an alkenyl group, or R5O, R6O, and R7O are siloxane represents a bond, and R8 is an alkyl, alkenyl or phenyl group which may contain an epoxy group or a glycidyl group in its molecule), 3 out of 4 substituents in the alkoxysilane are hydrolyzable substituents, and the remainder One of which consists of a non-hydrolyzable substituent is mentioned.

Specifically as the alkoxysilane represented by the formula (2), methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, γ-(methacryloxypropyl) Trimethoxysilane, γ-glycidoxypropyltrimethoxysilane, aminopropyltrimethoxysilane, β-(3,4epoxycyclohexyl)ethyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane , propyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, γ-(methacryloxypropyl)triethoxysilane, γ-glycidoxypropyltriethoxysilane, aminopropyltriethoxysilane, Vinyltris(β-methoxyethoxy)silane, etc. can be illustrated.

These may be added independently and may add 2 or more types. Moreover, these may add a monomer and may add a condensate. When a condensate is added, it may be a condensate of the same compound or a condensate of different compounds.

The amount of various alkoxysilanes different from the main component added to the coating solution for the purpose of further increasing the organic properties of the polymer film formed by application of the coating solution, as described above, relative to the alkoxysilane represented by Formula 1, which is the main component of the coating solution, It is important not to exceed 50%. When the amount added exceeds 50%, when the coating solution is applied to the substrate, the bond with the alkoxysilane represented by Formula 1, which is the main component, is not well formed, so that there is a fear that the strength of the polymer film may be lowered.

As a catalyst for curing and solidifying the alkoxysilane represented by Formula 1, which is the main component in the coating solution, and the alkoxysilane represented by Formula 2, which is optionally added to the coating solution, a commonly used catalyst can be used. For example, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, etc. can be illustrated as an acid catalyst.

Further, examples of the base catalyst include ammonia, tetramethylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide, ethanolamine, diethanolamine, and triethanolamine.

As described above, when using a commonly used catalyst, reaction water is required to cure and solidify the alkoxysilane. When the alkoxysilane, reaction water, and catalyst are coexisting, the coating solution tends to gel, so it is better to store it in a liquid state for a long time. it gets difficult Therefore, when the coating solution is to be stored in a liquid state for a long period of time, it is preferable to use a hydrolyzable organometallic compound instead of the catalyst. This is because the hydrolyzable organometallic compound does not require addition of reaction water in advance during curing and fixing of the alkoxysilane.

Examples of such organometallic compounds include those containing titanium, zircon, aluminum, and tin. Specifically, for example, tetrapropoxytitanate, tetrabutoxytitanate, tetrapropoxyzirconate, tetrabutoxyzirconate, tripropoxyaluminate, aluminum acetylacetate, dibutyltin diacetate , dibutyltin dilaurate, and the like can be exemplified.

In order to uniformly mix the alkoxysilane represented by Formula 1 described above, the alkoxysilane represented by Formula 2 added as needed, the catalyst, and the reaction water added according to the catalyst, adding an organic solvent or surfactant desirable. As an organic solvent used for this purpose, alcohol can be illustrated. Specific examples thereof include methanol, ethanol, propanol, isopropanol, butanol, pentanol, and hexanol. When using these, it can be used individually or in mixture of 2 or more types.

The addition of the organic solvent or surfactant as described below is effective in adjusting the viscosity or drying rate of the coating solution in addition to the above-mentioned purpose. It is preferable that the organic solvent to be added for this purpose is appropriately selected according to the purpose, having an appropriate viscosity or boiling point. Moreover, it can also be used simultaneously with the above-mentioned organic solvent. Specific examples of the organic solvent that can be added for this purpose include glycols such as ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, dipropylene glycol and polypropylene glycol, methoxyethanol, propoxyethanol, butoxyethanol. and cellosolves such as ethanol, methoxypropanol, ethoxypropanol, propoxypropanol and butoxypropanol.

In addition, since these glycols or cellosolves have hydroxyl groups in their molecules, they react with alkoxysilanes when condensed, and molecules having these organic properties may be introduced into the resulting siloxane bond network. Thereby, it becomes possible for the obtained coating film to increase organic property.

In addition to the above, a filler can be mix|blended with a coating liquid as needed. As a filler that can be used, silica, alumina, kaolin, mullite, zeolite, silicon carbide, silicon nitride, and metal (eg, titanium, iron, aluminum, cobalt, chromium, copper, etc.) oxides having an average particle diameter of about 0.03 to 5 μm , metal salts (silver nitrate, copper (II) nitrate, zinc (II) nitrate, silver sulfate, copper sulfate, zinc sulfate, silver acetate, copper acetate, zinc acetate, etc.) or an average diameter of about 0.05 to 2 μm and an average length of about A whisker of about 5-200 micrometers (For example, whiskers, such as potassium titanate, silicon nitride, silicon carbide), etc. are mentioned.

In addition, a film curing agent, a viscosity modifier, a stabilizer, a colorant, and the like may be added to the coating solution.

The coating solution described above is preferably left for about 1 hour to 1 day after preparation, or heated for several hours below the boiling point of the solvent used, and then used for coating paper or fiber materials.

The method for applying the coating solution to the surface of the paper material or the fiber material is not particularly limited, but, for example, dipping application, spray application, screen application, screen printing, offset printing, gravure printing, etc. can be used. Here, the coating solution is applied to the cellophane in an amount to be the thickness of the polymer film to be described later.

In addition, in order to improve the adhesion between the formed polymer film and the paper material or fiber material, the surface of the paper material or the fiber material may be pretreated before the coating solution is applied. Such pretreatments themselves are well known as known.

As a method for forming a polymer film from the applied coating solution, a heating method is generally used, and heating at a temperature of 300° C. or less, preferably 80 to 150° C. for 2 minutes to 1 hour is good. Of course, it can be heated to a higher temperature as long as it does not affect the paper material or the fiber material. Moreover, when a polymerizable unsaturated bond is contained in an alkoxysilane, UV irradiation etc. can be used together and a crosslinked structure can be formed again.

Further, in the coating material of the present invention, the polymer film having a polysiloxane structure as the main structure may be provided only on one side of the paper material or the fiber material, or it may be provided on both surfaces.

The thickness of a paper material such as cellophane paper, Japanese paper or brisket, or a fiber material such as a nonwoven fabric or cloth, which is the base material of the coating material of the present invention, is preferably 0.01 mm or more in terms of strength. In addition, the thickness of the polymer film having the polysiloxane structure as the main structure is not particularly limited, but for example, when used as a food packaging film or sheet, which is the second or third object of the present invention, which will be described later, oxygen In terms of barrier properties and heat resistance, it is preferably 2.5 to 25 µm.

Next, a food packaging film or sheet, and a food container provided by the present invention to achieve the second or third object described above will be described.

The film or sheet for food packaging and the food container of the present invention are composed of, for example, a coating material based on a paper material such as cellophane paper. Among them, cellophane tape can be preferably used for packaging of chocolate utilizing torsion characteristics, medicine bags, and exterior of candy/gum. Cellophane paper is commercially available, and such commercially available ones may be used. Examples of commercially available cellophane paper preferably used include Daiko cellophane (trade name, manufactured by Futamura Chemical Co., Ltd.) and Hakusan (trade name, manufactured by Rengo Co., Ltd.).

The film or sheet for food packaging of the present invention is provided by the coating material of the present invention in which the above-described coating material, that is, a polymer film having a polysiloxane structure as the main structure, is provided on one or both sides of a paper material such as cellophane or a fiber material. The former is the same as described above. The latter will be described below.

A polymer film having a polysiloxane structure as a main structure that can be formed from a coating solution containing an alkoxysilane represented by the formula (3) is as follows.

In the alkoxysilane represented by the formula (3), the alkoxy group is hydrolyzed in the presence of water, and then the hydrolyzate is dehydrated and condensed. When this series of reactions sufficiently proceeds, a polymer having a polysiloxane structure is produced. This fact is well known to those skilled in the art.

As R9 in the formula (3), for example, a hydrogen atom; Alkyl groups, such as a methyl group, an ethyl group, n-propyl group, and i-propyl group; Aryl groups, such as a phenyl group; alkenyl groups such as vinyl; β-(3,4-epoxycyclohexyl)ethyl group, γ-methacryloxypropyl group, γ-glycidoxypropyl group, γ-chloropropyl group, γ-mercaptopropyl group, γ -A substituted alkyl group such as aminopropyl group, N-phenyl-γ-aminopropyl group, N-β (aminoethyl)γ-aminopropyl group, trifluoromethyl group, 3,3,3-trifluoropropyl group, etc. can be exemplified.

Among these, it can be used 1 type or in combination of 2 or more types. By its selection, it is possible to control the properties of the resulting polymer film.

In particular, from the viewpoint of improving the toughness of the polymer film, it is preferable to have a reactive group excluding an alkoxy group as R 9 .

For example, a vinyl group, γ-methacryloxypropyl group, and γ-glycidoxypropyl group can be exemplified. By using these, in the resulting polymer film, not only a polysiloxane skeleton but also a cross-linked skeleton are formed by the crosslinking reaction of such reactive groups, thereby improving the toughness of the polymer film.

In formula (3), as R10, for example, a hydrogen atom; alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group and t-butyl group; Aryl groups, such as a phenyl group: Substituted alkyl groups, such as an acetyl group and (beta)-methoxyethoxy group, etc. can be illustrated.

Specific examples of the alkoxysilane represented by the formula (3) include tetrahydroxysilane, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyl Trimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyl Triethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, tri Fluoromethyltrimethoxysilane and trifluoromethyltriethoxysilane can be illustrated. These alkoxysilanes can be used individually or in combination of 2 or more types.

Among them, it is preferable to use an alkoxysilane in which X is 1 or to use an alkoxysilane in which X is 1 and 2 in combination so that the average of X does not exceed 2. By doing in this way, the polysiloxane structure has a three-dimensional crosslinked structure, and the polymer film can be made stronger.

Examples of the organic solvent used in the coating solution containing the alkoxysilane include alcohols such as methanol, ethanol, propanol, butanol, and 3-methyl-3-methoxybutanol; glycols such as ethylene glycol and propylene glycol; ethers such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, and diethyl ether; Ketones such as methyl isobutyl ketone and diisobutyl ketone; amides such as dimethylformamide and dimethylacetamide; acetates such as ethyl acetate, ethyl cellosolve acetate, and 3-methyl-3-methoxybutyl acetate; In addition to aromatic or aliphatic hydrocarbons such as toluene, xylene, hexane and cyclohexane, N-methyl-2-pyrrolidone, γ-butyrolactone, and dimethyl sulfoxide can be exemplified.

It is particularly preferable to use a solvent having a boiling point of 100 to 300°C from the viewpoint of improving the coatability of the resulting coating solution.

The amount of the solvent contained in the coating solution is preferably used in the range of 0.1 to 10.0 parts by weight based on 1 part by weight of the alkoxysilane in terms of applicability.

In order to cause hydrolysis and condensation reaction of the alkoxysilane represented by Formula 3, the water contained in the coating solution is preferably ion-exchanged water, and the amount is preferably used in the range of 1 to 4 moles per 1 mole of the alkoxysilane.

In addition, in order to proceed with the hydrolysis and condensation reactions, a catalyst may be used if necessary. Examples of the catalyst used include acid catalysts such as sulfuric acid, acetic acid, acetic anhydride, trifluoroacetic acid, formic acid, phosphoric acid, boric acid, p-toluenesulfonic acid, boric acid, and ion exchange resin, triethylamine, diethylamine, triethanolamine, and diethanol. Although base catalysts, such as an amine, sodium hydroxide, potassium hydroxide, etc. can be illustrated, an acid catalyst is preferable from the point of the toughness improvement of the film obtained. In particular, acids containing boron are preferred.

The amount of catalyst added to the coating solution is preferably used in the range of 0.001 to 0.1 parts by weight based on 1 part by weight of the alkoxysilane in consideration of the degree of polymerization of the polysiloxane structure, storage stability of the coating solution, and the flatness of the polymer film to be formed.

A metal alkoxide represented by the following Chemical Formula 4 or a chelate compound thereof may be blended in the coating solution.

Formula 4

M(OR11)m

In formula (4), M is preferably a metal atom such as titanium, zirconium, aluminum, tin, or zinc, but is not limited thereto. R 11 , when present in plurality, may be the same or different, and represents a hydrogen atom, an alkyl group, an aryl group, an alkenyl group and a substituent thereof, and m is the valence of the metal atom M.

When the alkoxide compound represented by Formula 4 is blended, the polysiloxane structure constituting the polymer film to be formed is modified by the metal oxide structure, and the effect of lowering the heating temperature for forming the polymer film is confirmed, and high temperature and high humidity resistance A further superior polymer film can be obtained. Among them, it is particularly preferable to use zirconium alkoxide or a chelate compound of zirconium alkoxide from the viewpoint of being very effective in improving the toughness of the polymer film.

The metal alkoxide or its chelate compound is preferably blended in an amount of 0.1 to 20 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the alkoxysilane represented by Formula (3).

In formula (4), as R11, for example, a hydrogen atom; alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group and t-butyl group; Aryl groups, such as a phenyl group; Substituted alkyl groups, such as an acetyl group and (beta)-methoxyethoxy group, etc. can be illustrated.

Specific examples of the metal alkoxide include tetraisopropoxytitanium, tetranormalbutoxytitanium, tetraisopropoxyzirconium, tetranormalbutoxyzirconium, triisopropoxyaluminum, and trinormalbutoxyaluminum.

The chelating compound of the metal alkoxide is easily obtained by reacting the metal alkoxide represented by the formula (4) with a chelating agent.

Examples of the chelating agent include β-diketones such as acetylacetone, benzoylacetone, and dibenzoylmethane;

β-keto acid esters such as ethyl acetate and ethyl benzoyl acetate, and the like can be exemplified.

Since the metal alkoxide reacts with various stoichiometric amounts of the chelating agent to form a corresponding metal chelate compound, the amount of the chelating agent to be used can be appropriately selected in the range of 0.1 to 10 moles per mole of the metal alkoxide.

In the reaction between the metal alkoxide and the chelating agent, it is preferable to use a reaction solvent subjected to dehydration treatment using a solvent that is azeotroped with the produced alcohol. For example, Alcohol, such as methanol, ethanol, a propanol, a butanol, 3-methyl-3- methoxybutanol; glycols such as ethylene glycol and propylene glycol; ethers such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, and diethyl ether;

ketones such as methyl isobutyl ketone and diisobutyl ketone; amides such as dimethylformamide and dimethylacetamide;

acetates such as ethyl acetate, ethyl cellosolve acetate, and 3-methyl-3-methoxybutyl acetate; In addition to aromatic or aliphatic hydrocarbons such as toluene, xylene, hexane and cyclohexane, N-methyl-2-pyrrolidone, γ-butyrolactone, dimethyl sulfoxide and the like can be exemplified. The amount of the solvent is arbitrarily selectable, and is preferably used in the range of 1 to 50.0 weight based on 1 weight of the metal alkoxide.

In addition, the reaction temperature is selected in the range of the freezing point to the boiling point of the reaction solvent. The reaction atmosphere is preferably carried out under a nitrogen atmosphere.

The coating solution described above includes an alkoxysilane represented by Formula 3, water, a catalyst for hydrolysis and condensation, and, if necessary, a metal alkoxide represented by Formula 4 or a metal chelate compound derived from the metal alkoxide. It is prepared in the form of a solution dissolved in one organic solvent, preferably an organic solvent having a boiling point of 100°C to 300°C. As a preparation method, after mixing at room temperature, it is preferable to leave it for about 1 hour to 1 day, or to heat below the boiling point of a solvent for several hours.

In addition, a filler can be mix|blended with the coating liquid as needed. As fillers that can be used, silica, alumina, kaolin, mullite, zeolite, silicon carbide, silicon nitride, oxides of metals (eg, titanium, iron, aluminum, cobalt, chromium, copper, etc.) having an average particle diameter of about 0.03 to 5 μm, metals of salts (silver nitrate, copper(II) nitrate, zinc(II) nitrate, silver sulfate, copper sulfate, zinc sulfate, silver acetate, copper acetate, zinc acetate, etc.) or an average diameter of about 0.05 to 2 μm, and an average length of about 5 to 200 A whisker of micrometer (For example, whiskers, such as potassium titanate, silicon nitride, silicon carbide), etc. can be illustrated.

In addition, a film curing agent, a viscosity modifier, a surfactant, a stabilizer, a colorant, and the like may be added to the coating solution.

The method for applying the coating solution to the surface of the paper material or the fiber material is not particularly limited, but, for example, dipping application, spray application, screen application, screen printing, offset printing, gravure printing and the like can be used. Here, the coating solution is applied to the cellophane in an amount corresponding to the thickness of the polymer film to be described later.

In addition, the surface of the paper material or the fiber material may be pretreated before the coating solution is applied in order to improve the adhesion between the formed polymer film and the paper material or fiber material. Such pretreatments themselves are well known and well known.

As a method for forming a polymer film from the applied coating solution, the heating method is generally performed at a temperature of 300° C. or lower, preferably 80 to 150° C. for 2 minutes to 1 hour. Of course, as long as it does not affect the paper material or the fiber material, it can be heated to a higher temperature. Moreover, when a polymerizable unsaturated bond is contained in an alkoxysilane, UV irradiation etc. can be used together and a crosslinked structure can be formed again.

Further, in the present invention, the polymer film having the polysiloxane structure as the main structure may be provided on only one side of the paper material or the fiber material, or it may be provided on both surfaces.

The thickness of a paper material such as cellophane paper, Japanese paper or brisket, which is the base material of the coating material of the present invention, or a fiber material such as a nonwoven fabric or cloth is preferably 0.1 mm or more in terms of strength. In addition, the thickness of the polymer film having a polysiloxane structure as the main structure is not particularly limited, but is 2.5 in terms of oxygen barrier properties and heat resistance when used as a food packaging film or sheet, and a food container, which is the second or third object of the present invention It is preferably from 25 μm.

As described above, the second object of the present invention is to provide a paper material or a fiber material, and a film or sheet for packaging food in which a polymer film having a polysiloxane structure as a main structure is provided on at least one surface of the material. The third object of the present invention, a food container, is provided by processing and molding a film or sheet having such a configuration by a method known per se, for example, extraction from a mold, extrusion from a mold, vacuum molding, and the like.

In addition, a paper material such as cellophane paper is made in the shape of a food container in advance, and the coating solution is applied to the surface by a method such as dipping application or spray application, and then a polymer film having a polysiloxane structure as the main structure by the above method may form.

The container for food of the present invention is used, for example, in a container used for cooking by a microwave oven, a paper cup, a seasoning container, a deodorant container, and the like, but is not limited thereto. In particular, when used for cooking by a microwave oven, it exhibits an excellent effect that the shape of the container is not damaged even when the cooking temperature exceeds 200°C.

And, the fourth object of the present invention is achieved by processing the above-described film or sheet for packaging food. That is, a film or sheet for food packaging comprising a paper material or a fiber material and a polymer film having a polysiloxane structure as a main structure provided on at least one side of the material is prepared by a method known per se, for example, mold extraction, mold extrusion, It is processed and molded by a method such as vacuum molding, and is used as a liquid crystal surface protective cover or clear holder of electronic devices, transparent stationery products such as film cases, transparent air freshener containers, and water-repellent sheets on the surface of automobile side mirrors.

The liquid crystal surface protective cover of an electronic device may be provided by, for example, cutting a coating material of a predetermined thickness prepared using a transparent or translucent paper material as a substrate to a predetermined size. In addition, for transparent stationery products such as clear holders and film cases, transparent air freshener containers, and water-repellent sheets on the surface of car side mirrors, for example, a transparent or translucent paper material as a base material, etc., a coating material of a predetermined thickness It can be provided by cutting it to a predetermined size and making it into a bag shape.

The coating material in which the polymer film having the polysiloxane structure of the present invention is formed does not require a plasticizer and does not contain chlorine atoms, so it is friendly to the global environment, such as not generating dioxins even when incinerated. In addition, the polymer film having a polysiloxane structure as a main structure provided on the surface thereof imparts an insulating effect and water repellency, adequate strength and good light transmittance, and flame retardancy to the coating material.

As a result, films or sheets for food packaging, food containers, transparent stationery products such as clear holders and film cases, transparent air freshener containers, and water-repellent sheets for car side mirrors are produced with these coating materials. Then, it is possible to provide an excellent product that is rich in insulation effect and water repellency, has adequate strength and good light transmittance, and is also rich in flame retardancy.

Hereinafter, the present invention will be specifically described based on examples, and the scope of the present invention is not limited thereto.

Example 1: Preparation of film or sheet for food packaging and preparation of evaluation coating solution

Alkoxysilane of 10 moles of methyltrimethoxysilane and 10 moles of phenyltrimethoxysilane was dissolved in 4 kg of 3-methyl-3-methoxybutanol, and an aqueous solution of phosphoric acid (60 moles of water, 0.17 moles of phosphoric acid) was stirred while stirring. added to prepare a solution (A).

Separately, 1 mole of tetrabutoxyzirconium was dissolved in 1500 g of 3-methyl-3-methoxybutanol, and 5 moles of ethyl acetate was added thereto with stirring. The obtained solution was reacted with stirring at room temperature for 1 hour to prepare a solution (B) (concentration: 4.7%) containing a chelate compound of zirconium.

Then, 650 g of solution (A) and 50 g of solution (B) were mixed, stirred at room temperature for 2 hours to make a homogeneous solution, and the solid content concentration was increased to 25% using 3-methyl-3-methoxybutanol again. adjusted to obtain a coating solution.

Formation of a polymer film on the surface of cellophane. The prepared coating solution is applied to one side of cellophane paper (trade name: Daiko cellophane, manufactured by Futamura Chemical Co., Ltd., thickness 0.03 mm) using a gravure roll coater and applied at 150° C. for 3 minutes. By heating, a polymer film having a thickness of 2 mu m and having a polysiloxane structure as the main structure was formed on one side of the cellophane paper. A film based on this cellophane paper is called modified cellophane paper. The total thickness of the modified cellophane paper was 0.032 mm and was transparent.

Evaluation of the properties of modified cellophane paper

(1) Measurement of oxygen permeability

With respect to the modified cellophane paper, a film is attached to a ring with a diameter of 11 cm with an OXTRAN-100A-S type device manufactured by Modern Controls, with 100% oxygen on the top and 100% nitrogen on the bottom, the amount of oxygen transferred when oxygen moves to the nitrogen side The amount of oxygen in the saturated state was measured to determine the oxygen transmittance. As a control test, oxygen permeability was measured for unmodified cellophane paper and polyvinylidene chloride film (PVDC). The result is as follows.

(A) Modified cellophane paper: 0.3 (cc/atm/m2/24 hr)

(B) Unmodified cellophane: 1000 (cc/atm/m2/24 hr)

(C) PVDC : 0.03 (cc/atm/m2/24 hr)

(2) moisture permeability

Moisture permeability was measured by the method described in JIS Z 0208 with respect to the modified cellophane paper. As a control test, moisture permeability was also measured for unmodified cellophane paper and polyvinylidene chloride film (PVDC). The result is as follows.

(A) Modified cellophane paper: 1800 (cc/atm/m2/24 hr)

(B) Unmodified cellophane paper: upper limit of measurement (cc/atm/m2/24 hr)

(C) PVDC :2 (cc/atm/m2/24 hr)

(3) flue gas test

Hydrogen chloride concentration in combustion gas was measured according to JIS K 7271 (analysis method of plastic combustion gas) for modified cellophane, but it was not detected. This indicates that no dioxin is generated even when the modified cellophane prepared in Example 1 is burned.

From the results shown above, it is clear that the modified cellophane prepared in Example 1 is excellent for packaging food.

Example 2: Preparation and evaluation of containers for food

A cup-shaped transparent container having a bottom diameter of 35 Φ and a height of 20 mm was prepared from the modified cellophane paper prepared in Example 1. Tempura chicken was put here as food, and it was heated and cooked for 3 minutes in a microwave oven (trade name: NE-N255, manufactured by Matsushita Denki Sangyo Co., Ltd.). Although the temperature of the food was raised to 220° C., practically no change was found in the shape of the food container.

Therefore, it is clear that the container produced in Example 2 is excellent as a container for food for microwave cooking.

Example 3: Manufacture and evaluation of containers other than food containers

The modified cellophane paper of a predetermined thickness prepared in Example 1 was cut to a predetermined size and used as a liquid crystal surface protective cover of an electronic device. Examples of the liquid crystal surface protective cover for this type of electronic device product include a liquid crystal screen protective cover for a mobile phone, a liquid crystal protective cover for a notebook computer, and an electric device display plate (name plate) and operation display plate. Since it has water repellency and waterproofness even when used for this type of protective cover plate, it can replace the conventional plastic surface protective cover plate. Moreover, there is no generation of harmful substances such as dioxins during treatment, so it is environmentally friendly.

Example 4: Manufacture and evaluation of containers other than food containers - Part 2 of the modified cellophane paper of a predetermined thickness prepared in Example 1 was cut to a predetermined size and made into a bag shape to clear

It was used as a transparent stationery article, such as a holder and a film case. In addition, it was used as a water-repellent sheet which affixed to the surface of a transparent air freshener container and a car side mirror, and made raindrops water-repellent.

Since it has water repellency and waterproof properties even when used in these kinds of articles, it is useful as a conventional transparent vinyl chloride and acrylic substitute.

Example 5: Coating with paper and fiber materials

As the alkoxysilane represented by the formula (1) that can be used for producing the coating material of the present invention, the ones shown in Table 1 (polymers) are assumed, and among them, No. 3 (methyltrimethoxysilane oligomer; MTM) , No.10 (methyltriethoxysilane oligomer; MTE), and No.7 (ethyltrimethoxysilane oligomer; ETM) were synthesized as follows. In addition, in order to compare the properties thereof, those shown in Table 2 were synthesized and compared.

In addition, in Table 1, Compound 1 is the name of the alkoxysilane represented by Formula 1, and Compound 2 is the name of the alkoxysilane represented by Formula 2.

Synthesis of Alkoxysilane Polymers

(1) Methyltrimethoxysilane oligomer (MTM)

181 g of methyltrimethoxysilane, 50 g of methanol, and 18 g of pure water were added to a 500 ml three-necked flask, and the mixture was sufficiently stirred. Again, 2 g of 61% nitric acid was added, and the mixture was heated and refluxed for 3 hours while stirring. After completion of the reaction, the inside of the reaction vessel was decompressed while heating to remove methanol.

According to gas chromatography analysis, the MTM thus obtained was centered on 3 to tetramers.

A paper material (0.13 mm thick press board, manufactured by Miki Tokushu Seishi Co., Ltd.) was coated using the coating solution used in this Example. Coating conditions were that the coating solution was coated on both sides of the paper to a thickness of 25 μm, and dried at 100° C. for 10 minutes, and then dried at 150° C. for 10 minutes. The coated paper on which the film was formed was measured, and it had physical properties as shown in Table 3.

※ Thickness, density, tensile strength, and dielectric breakdown strength were measured in accordance with JIS C 2315. Surface resistivity and volume resistivity were measured in accordance with JIS K 6911. The one-hour water absorption was measured in accordance with the Electrical Appliances Control Law. After heating, it was heated at 105° C. for 24 hours, and then cooled in an atmosphere of 0% humidity for measurement. Moisture absorption was quickly measured after 24 hours at 40°C and 90% RH.

From the results shown in Table 3, it is clear that a coating material having excellent properties for food packaging can be provided by using the coating solution shown in Example 5.

(2) Methyltriethoxysilane/oligomer (MTE) 273 g of methyltriethoxysilane, 50 g of ethanol, and 18 g of pure water were added to a 500 ml three-necked flask and thoroughly stirred. Again, 2 g of 61% nitric acid was added, and the mixture was heated and refluxed for 12 hours while stirring. After completion of the reaction, the inside of the reaction vessel was decompressed while heating to remove methanol.

The MTE thus obtained was centered on 3 to tetramers by gas chromatography analysis. (3) Ethyltrimethoxysilane oligomer (ETM)

200 g of ethyltrimethoxysilane, 50 g of methanol, and 18 g of pure water were added to a 500 ml three-necked flask, and the mixture was sufficiently stirred. Again, 2 g of 61% nitric acid was added, and the mixture was heated and refluxed for 7 hours while stirring. After completion of the reaction, the inside of the reaction vessel was decompressed while heating to remove methanol.

The ETM thus obtained was centered on 3 to tetramers by gas chromatography analysis.

Claims (19)

A coating material comprising a paper material or a fiber material and a polymer film having a polysiloxane structure as a main structure provided on at least one side of the material. The coating material according to claim 1, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from a coating solution containing an alkoxysilane represented by the following formula (1).

(Wherein, R1, R2, R3, and R4 may be the same as or different from each other, and are hydrogen or an alkyl group having 1 to 4 carbon atoms, and n is 2 to 8.) The method according to claim 1, wherein the polymer film having the polysiloxane structure as the main structure is represented by Chemical Formulas 1 and 2, wherein 3 of the 4 substituents are hydrolyzable substituents, and the remaining 1 is composed of non-hydrolyzable substituents. A coating material, which is a polymer film formed from the coating solution containing an alkoxysilane.

(Wherein, R5, R6, and R7 may be the same or different from each other, and are hydrogen, an alkyl group having 1 to 10 carbon atoms or an alkenyl group, or R5O, R6O, R7O represents a siloxane bond, and R8 is an epoxy group in its molecule or It is an alkyl group, an alkenyl group, or a phenyl group which may include a glycidyl group.) The coating material according to claim 1, wherein the polymer film having the polysiloxane structure as a main structure is a polymer film formed from the coating solution by a catalyst containing a hydrolyzable organometallic compound. The coating material according to claim 4, wherein the hydrolyzable organometallic compound is an organometallic compound comprising titanium, zircon, aluminum or tin. A film or sheet for packaging food comprising a paper material or a fiber material and a polymer film having a polysiloxane structure as a main structure provided on at least one side of the material. The film or sheet for food packaging according to claim 6, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from a coating solution containing an alkoxysilane represented by the following formula (3).
<Formula 3>
R9XSi(OR10)4-X
(Wherein, R9 and R10 may be the same as or different from each other, and represent a hydrogen atom, an alkyl group, an aryl group, an alkenyl group, or a substituent thereof, and X is an integer of 0 to 2.) The film or sheet for food packaging according to claim 6, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from a coating solution containing an alkoxysilane represented by the formula (1). The method according to claim 8, wherein the polymer film having the polysiloxane structure as the main structure comprises the alkoxysilane represented by Formula 1 and the alkoxysilane represented by Formula 2, 3 of the 4 substituents are hydrolyzable substituents, and the remainder One is a film or sheet for food packaging, which is a polymer film formed from the coating solution containing an alkoxysilane consisting of a non-hydrolyzable substituent. The food packaging film or sheet according to claim 6, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from the coating solution by a catalyst containing a hydrolyzable organometallic compound. The film or sheet for packaging food according to claim 10, wherein the hydrolyzable organometallic compound is an organometallic compound comprising titanium, zircon, aluminum or tin. A food container comprising a paper material or a fiber material and a polymer film having a polysiloxane structure as a main structure provided on at least one side of the material. The food container according to claim 12, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from a coating solution containing an alkoxysilane represented by the formula (3). The food container according to claim 12, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from a coating solution containing the alkoxysilane represented by the formula (1). 15. The method of claim 14, wherein the polymer film having the polysiloxane structure as the main structure is represented by the formula (2), three of the four substituents are hydrolyzable substituents, and the remaining one contains an alkoxysilane consisting of a non-hydrolyzable substituent. A food container that is a polymer film formed from the coating solution. The food container according to claim 12, wherein the polymer film having the polysiloxane structure as the main structure is a polymer film formed from the coating solution by a catalyst containing a hydrolyzable organometallic compound. The food container according to claim 16, wherein the hydrolyzable organometallic compound is an organometallic compound comprising titanium, zircon, aluminum or tin. The film or sheet for food packaging according to claim 6, wherein the film or sheet for food packaging is used as a liquid crystal surface protection cover of an electronic device by cutting a film or sheet having a predetermined thickness to a predetermined size. The method according to claim 6, wherein the film or sheet for food packaging is cut to a predetermined size and made into a bag shape to be used as a transparent stationery article such as a clear holder, a film case, a transparent air freshener container, or a water-repellent sheet on the surface of a car side mirror Film or sheet for food packaging.