JP2019218492A - Method for producing modified film - Google Patents

Abstract

To provide a method for producing a modified film in which an olefinic polymer film is efficiently modified, preferably mainly at a specific site (e.g. surface).SOLUTION: A method for producing a modified film in which an olefinic polymer film with a melting point and/or glass transition temperature of 50°C or more and 300°C or less is partially or wholly modified, has a step 1 in which a radical containing an atom (α) of an element selected from a group 15 element and a group 16 element and an atom (β) of a group 17 element in one molecule, at a ratio of the number of atoms (α): the number of atoms (β)=1:1-4:1.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a modified film.

  Olefin-based polymers are industrially produced by various methods because of their high industrial utility value, and are said to have a production volume exceeding 100 million tons per year. Since the olefin polymer contains carbon and hydrogen as main components, it is also characterized by a stable and inexpensive material. On the other hand, a structure having no functional group has a poor affinity for a material having polarity, and also has a property that it is difficult to modify coloring and adhesion.

  As a method for modifying an olefin-based polymer film, surface treatment such as corona discharge treatment and plasma treatment is known (eg, Patent Document 1).

JP-A-2003-218814

However, in the conventional method for modifying an olefin-based polymer film, the molecular weight of the polymer constituting the film is reduced, a cross-linking reaction occurs, and the polymer tends to be easily deteriorated or yellowed. I understood.
In particular, in the case of a film, a decrease in the molecular weight may lead to a decrease in not only the strength but also the durability, and the molecular weight distribution may be narrowed to make molding difficult.

In addition, for example, a release film, an exterior film, a display film in which a dye or a paint is laid down only in a portion that becomes a part of a picture or a pattern, for example, only a part of the film is modified. Sometimes it is good.
The present inventors considered that if a specific portion (eg, surface) could be mainly modified, it would be possible to expect a higher modification effect while suppressing a decrease in strength as a film.

  The present invention has been made in view of the above points, and it is an object of the present invention to provide a method for producing a modified film obtained by modifying an olefin polymer film efficiently, preferably at a specific location (eg, surface). Aim.

  As a result of research conducted by the present inventors, they have found that the above-described problems can be solved according to the following configuration examples. A configuration example of the present invention is as follows.

[1] In one molecule, the atom (α) of the element selected from the group 15 element and the group 16 element and the atom (β) of the group 17 element are obtained by dividing the number of atoms (α) by the number of atoms (β) = Step 1 of irradiating with light in the presence of a radical containing at a ratio of 1: 1 to 4: 1.
A method for producing a modified film obtained by modifying a part or all of an olefin polymer film having a melting point and / or a glass transition temperature of 50 ° C. or more and 300 ° C. or less.

[2] The method for producing a modified film according to [1], wherein the step 1 is a step of irradiating the radical with light in the presence of the radical and the film to modify the film.
[3] The modified fabric according to [1] or [2], wherein the step 1 is a step of irradiating the radical and the film with light in the presence of the radical and the film to modify the film. Manufacturing method.

  [4] The method for producing a modified film according to any one of [1] to [3], wherein the thickness of the modified film is 1 to 1000 μm.

  [5] The method for producing a modified film according to any one of [1] to [4], wherein the radical is a chlorine dioxide radical.

  [6] The method for producing a modified film according to any one of [1] to [5], wherein the olefin polymer is a 4-methyl-1-pentene polymer.

[7] The method for producing a modified film according to any one of [1] to [6], wherein the modified film is a porous film.
[8] The method for producing a modified film according to any one of [1] to [7], wherein the modified film is a release film.

  ADVANTAGE OF THE INVENTION According to the manufacturing method of this invention, a specific location of an olefin polymer film can be mainly mainly modified efficiently. Therefore, it is possible to provide a modified film which is capable of suppressing a decrease in the molecular weight of the polymer constituting the film, a crosslinking reaction, deterioration, yellowing, etc., and making use of the original properties of the film, and having excellent modifying properties and design properties. It is considered possible.

FIG. 1 is a schematic diagram showing a state when a TPX film is modified in an example. FIG. 2 is a diagram showing the results of evaluating the hydrophilicity of a TPX film in Examples.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following description.

製造 Method for producing modified film≫
In the method for producing a modified film according to the present invention (hereinafter also referred to as “the present method”), a part or all of an olefin polymer film having a melting point and / or a glass transition temperature of 50 ° C. or more and 300 ° C. or less is modified. A method for producing a modified film,
In one molecule, the atom (α) of the element selected from the group 15 element and the group 16 element and the atom (β) of the group 17 element are defined as the number of atoms (α): the number of atoms (β) = 1: 1. Step 1 of irradiating light in the presence of radicals contained in a ratio of 4: 1.
Hereinafter, the olefin polymer film before modification is simply referred to as “film”, and the film after modification is referred to as “modified film”.

According to such a method, it is possible to easily obtain a modified film in which a specific portion such as the surface of the film is mainly modified while efficiently utilizing the film, specifically, the inherent properties of the film.
Further, in the conventional reforming method, the reforming effect tends to deteriorate with time, but according to the present method, suppression of the deterioration with time can be expected.

  According to this method, the film can be efficiently denatured (eg, oxidized) by a very simple method of merely irradiating the radical with light and under extremely mild conditions such as normal temperature and normal pressure. Can be. Furthermore, according to the present method, for example, the film can be efficiently modified (oxidation reaction) without using a radical generator such as a peroxide or an azo compound which may be unstable at the handling temperature.

<Step 1>
In the step 1, in one molecule, the atom (α) of an element selected from the group 15 element and the group 16 element and the atom (β) of the group 17 element are added to the number of atoms (α): This is a step of irradiating light in the presence of a radical containing the number = 1: 1 to 4: 1.
The step 1 may be light irradiation in the presence of the radical, but is preferably a step of irradiating the radical with light in the presence of the radical.

The method for modifying the film is not particularly limited, and the method (I) of irradiating the radicals with light in the presence of the radicals and the film [the film is irradiated with the radicals in the presence of the radicals and the film, Modification Method] is preferred.
As a method for modifying the film, besides this method (I), for example, a method (II) of contacting the film subjected to the step 1 with the film can also be mentioned.

The method (I) may be performed by irradiating the radicals with light. The method of irradiating the radicals and the film with light [in the presence of the radicals and the film, irradiating the radicals and the film with light] Modification Method], and a method in which the film is not irradiated with light may be used.
When irradiating the radical and the film with light, each of the radical and the film may be separately illuminated with light. For example, it is preferable to irradiate the radical and the film with light from one light source at the same time. .

  The step 1 may be a liquid phase method in which the film is immersed (contacted) in the aqueous phase and / or the organic phase containing the radical, and the film is brought into contact with the aqueous phase and / or the organic phase containing the radical. Performed without performing, may be a gas phase method, may be performed in a gas phase containing the radicals and the film, may be a gas phase method, as the film, for example, when using a film having a hygroscopic property, the residual solvent and the like If problematic, the gas phase method is preferred in some circumstances.

The radical includes an atom (α) of an element selected from a Group 15 element and a Group 16 element and an atom (β) of a Group 17 element.
The radical may include two or more atoms of a Group 15 element, may include two or more atoms of a Group 16 element, and may include one or more atoms of a Group 15 element and a Group 16 element, respectively. And may contain two or more atoms of Group 17 elements. However, in these cases, the ratio of the number of atoms is the ratio of the total number of atoms of the group 15 element and the group 16 element to the total number of atoms of the group 17 element.

The atom (α) preferably includes nitrogen, oxygen, and sulfur, and is particularly preferably oxygen.
The atom (β) preferably includes chlorine, bromine and iodine, and chlorine and bromine are preferable. Among these, chlorine is more preferable because a radical containing chlorine is easily available. When a radical containing chlorine is used, the light to be irradiated is preferably light containing ultraviolet light. When a radical containing bromine or iodine is used, light having a longer wavelength than the ultraviolet light can be used. Therefore, bromine and iodine are preferable in some situations, such as when the degree of freedom of light selection is taken into consideration, or when there is a possibility that light deterioration may occur in the film.

  In the radical, the ratio of the atom (α) to the atom (β) in one molecule of the radical is 1 to 4, preferably 1 or 2, and more preferably 2.

As the radical, a chlorine dioxide radical is preferable.
When light irradiation is performed in the presence of chlorine dioxide radicals (ClO _2. ), For example, it is considered that chlorine radicals (Cl.) And oxygen molecules (O ₂ ) are generated by irradiating the chlorine dioxide radicals with light.

The light (wavelength) used for the light irradiation may be appropriately selected depending on the radical used. Specifically, a wide range from the infrared region to the ultraviolet region can be selected, but is, for example, 200 nm or more, for example, 800 nm or less.
The light irradiation time is not particularly limited, but is, for example, 1 minute or more, for example, 1000 hours or less.

  Although the light source in the light irradiation is not particularly limited, for example, natural light such as sunlight is used from the viewpoint of simplicity. Further, for example, a light source such as a xenon lamp, a halogen lamp, a fluorescent lamp, and a mercury lamp may be appropriately used instead of or in addition to the natural light. Further, if necessary, a filter for cutting a wavelength other than the required wavelength may be appropriately used.

The temperature, pressure, and atmosphere for performing the step 1 are not particularly limited, but the reaction temperature is, for example, 0 ° C. or more, for example, 100 ° C. or less, and the pressure is, for example, 0.1 MPa or more, and 100 MPa or less. The atmosphere includes, for example, an air atmosphere and an inert gas atmosphere.
This method is performed, for example, in the air at normal temperature (eg, 5 to 35 ° C.) and normal pressure (atmospheric pressure) without performing any heating, pressurizing, depressurizing, or the like, as described in Examples below. It is also possible.

  The light irradiation is performed on radicals present in an aqueous phase, an organic phase and / or a gas phase. When importance is placed on reducing the load on the environment and the effect on the human body, it is preferable to perform the treatment on radicals present in the aqueous phase or gas phase.

  When the film is immersed in an aqueous or organic phase, the amount of the film used in the aqueous or organic phase is not particularly limited, but is, for example, 1 g / L or more with respect to the aqueous or organic phase, For example, it is 10 g / L or less.

  The aqueous phase is not particularly limited as long as it contains water.

The organic phase is not particularly limited as long as it contains an organic solvent.
The organic solvent is not particularly limited, and examples thereof include a hydrocarbon solvent and a halogenated solvent.
The organic solvent may be one kind or two or more kinds.

  Although it does not specifically limit as said hydrocarbon solvent, For example, n-hexane, cyclohexane, benzene, toluene, o-xylene, m-xylene, and p-xylene are mentioned.

  The halogenated solvent is not particularly restricted but includes, for example, methylene chloride, chloroform, carbon tetrachloride, carbon tetrabromide and fluorous solvents.

  The fluorous solvent is a solvent in which all or most of the hydrogen atoms of a hydrocarbon are substituted with fluorine atoms. The fluorous solvent may be, for example, a solvent in which 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more of the number of hydrogen atoms of a hydrocarbon are substituted with fluorine atoms.

As the fluorous solvent, for _{example, CF 3 - (CF 2)} n -CF 3 (n is 4~7), N - ((CF 2) n CF 3) 3 (n is 1 or 4), hexafluorobenzene , 1- (trifluoromethyl) undecafluorocyclohexane, 1- (trifluoromethyl) pentafluorobenzene, and octadecafluorodecahydronaphthalene, among which, for example, CF ₃ (CF ₂ ) ₄ CF ₃ is preferable. .

  Fluorous solvents have the advantage that side reactions can be suppressed or prevented, for example, due to the low reactivity of the solvent itself. Examples of the side reaction include an oxidation reaction of a solvent, a hydrogen abstraction reaction of a solvent by radicals, and a chlorination reaction.

The aqueous phase may include components other than the radicals and water, and the organic phase may include components other than the radicals and the organic solvent.
Examples of the other components include, but are not particularly limited to, a source of the radical, a Bronsted acid, a Lewis acid, and oxygen (O ₂ ).
Each of these may be used alone or in combination of two or more.
The other component may be dissolved in the aqueous phase and / or the organic phase, but may not be dissolved.
Note that one substance may also serve as a Lewis acid and a Bronsted acid. "Lewis acid" refers to a substance that acts as a Lewis acid for the source of the radical.

The source of the radical is not particularly limited, but when the radical is a chlorine dioxide radical, for example, chlorous acid (HClO ₂ ) or a salt thereof may be mentioned. The salt of chlorite is not particularly limited, and examples thereof include metal salts. Examples of the metal salt include an alkali metal salt, an alkaline earth metal salt, and a rare earth salt.
More specifically, the source of the chlorine dioxide radical is, for example, sodium chlorite (NaClO ₂ ), lithium chlorite (LiClO ₂ ), potassium chlorite (KClO ₂ ), magnesium chlorite (Mg (ClO ₂ ) ₂ ) and calcium chlorite (Ca (ClO ₂ ) ₂ ). Among these, sodium chlorite is preferred in terms of cost, ease of handling, and the like.

  The concentration of the radical generating source in the aqueous phase and / or the organic phase is not particularly limited, but is, for example, 0.0001 mol / L or more, for example, 1 mol / L or less.

The Lewis acid is not particularly limited, and may be, for example, an organic substance or an inorganic substance.
Examples of the organic substance include an ammonium ion and an organic acid (eg, carboxylic acid).
The inorganic substance may include one or both of a metal ion and a non-metal ion. The metal ion may include one or both of a typical metal ion and a transition metal ion.
Examples of the inorganic substance include alkaline earth metal ions (eg, Ca ²⁺ ), rare earth ions, Mg ²⁺ , Sc ³⁺ , Li ⁺ , Fe ²⁺ , Fe ³⁺ , Al ³⁺ , silicate ions, and the like. It may be at least one selected from the group consisting of borate ions.
Examples of the alkaline earth metal ion include calcium, strontium, barium and radium ions, and more specifically, Ca ²⁺ , Sr ²⁺ , Ba ²⁺ and Ra ²⁺ .
The "rare earth" is a general term for two elements, scandium and yttrium, and 15 elements (lanthanoids) from lanthanum to lutetium, for a total of 17 elements. Examples of the rare earth ion include a trivalent cation.

Further, when the Lewis acid is an ion, the Lewis acid may be a substance having a counter ion of the ion, such as trifluoromethanesulfonic acid ion (CF ₃ SO ₃ ⁻ ). , Trifluoroacetate ion (CF ₃ COO ⁻ ), acetate ion, fluoride ion, chloride ion, bromide ion, iodide ion, sulfate ion, hydrogen sulfate ion, sulfite ion, nitrate ion, nitrite ion, phosphate ion And phosphite ions.

The Lewis acid may be at least one selected from the group consisting of AlCl ₃ , AlMeCl ₂ , AlMe ₂ Cl, BF ₃ , BPh ₃ , BMe ₃ , TiCl ₄ , SiF ₄ and SiCl ₄ . Among these, “Ph” represents a phenyl group, and “Me” represents a methyl group.

  The Lewis acidity of the Lewis acid is, for example, 0.4 eV or more, but is not limited thereto. The upper limit of the Lewis acidity is not particularly limited, but is, for example, 20 eV or less. The Lewis acidity is, for example, Ohkubo, K .; Fukuzumi, S. Chem. Eur. J., 2000, 6, 4532, J. AM.CHEM. SOC. 2002, 124, 10270-10271, or J. Org. Chem. 2003, 68, 4720-4726.

The Bronsted acid is not particularly limited, but includes, for example, an inorganic acid and an organic acid, and specifically, for example, trifluoromethanesulfonic acid, trifluoroacetic acid, acetic acid, hydrofluoric acid, hydrochloric acid, and odor. Examples include hydrofluoric acid, hydroiodic acid, sulfuric acid, sulfurous acid, nitric acid, nitrous acid, phosphoric acid, and phosphorous acid.
Acid dissociation constant pK _a of the Bronsted acid is, for example, 10 or less. The lower limit of the pK _a is not particularly limited, for example, is -10 or more.

  The concentration of at least one of the Lewis acid and the Bronsted acid in the aqueous phase and / or the organic phase is not particularly limited, and can be appropriately set, but is, for example, 1 mg / L or more, for example, 1 g / L or less. It is.

For example, oxygen (O ₂ ) can be dissolved in the aqueous phase and / or the organic phase by blowing air or oxygen gas into the aqueous phase and / or the organic phase. At this time, for example, the aqueous phase and / or the organic phase may be saturated with oxygen (O ₂ ).
When the aqueous phase and / or the organic phase contains the oxygen (O ₂ ), for example, the denaturation (oxidation reaction) of the film can be promoted.

<Radical generation step>
The method may include a radical generating step of generating the radical, specifically, a step of generating the radical from the radical generating source.

  The radical generating step is not particularly limited. For example, the radical generating step (eg, chlorous acid or a salt thereof) is dissolved in water and allowed to stand, and the radical generating step is performed by spontaneously generating the radical from the radical generating source. Can be. At this time, for example, the presence of at least one of the Lewis acid and the Bronsted acid in the water can promote the generation of the radical. Also, for example, the radicals can be generated by irradiating light to an aqueous phase in which the radical generating source is dissolved in water. The light irradiation may be the light irradiation in the above step 1, that is, the radicals may be irradiated with light while generating the radicals.

For example, the mechanism (mechanism) for generating chlorine dioxide radicals from chlorite ions is assumed, for example, as shown in Scheme 1 below. However, the following scheme 1 is an example of a presumed mechanism, and does not limit the present invention at all.
The first (upper) reaction formula of the following scheme 1 shows a disproportionation reaction of chlorite ion (ClO ₂ ⁻ ), and the presence of at least one of a Lewis acid and a Bronsted acid in the reaction system. It is thought that the equilibrium is likely to move to the right.
The second (middle) reaction formula in Scheme 1 below shows a dimerization reaction, in which hypochlorite ion (ClO ⁻ ) generated in the disproportionation reaction reacts with chlorite ion to form dioxide. Chlorine (Cl ₂ O ₂ ) is produced. This reaction is considered to proceed more easily as the amount of protons H ⁺ in the water increases, that is, as the water becomes more acidic.
The third (lower) reaction scheme in Scheme 1 below represents radical generation. In this reaction, dichlorine dioxide generated by the dimerization reaction reacts with chlorite ions to generate chlorine dioxide radicals.

  Further, in the present method, since the film has a carbon-hydrogen single bond, the reaction proceeds by the same mechanism as the mechanism (mechanism) of the ethane oxidation reaction described in JP-A-2017-155017, for example. I can guess.

<Film>
The film is a film containing an olefin polymer having a melting point and / or a glass transition temperature of 50 ° C. or more and 300 ° C. or less.

The olefin polymer is not particularly limited, and examples thereof include an ethylene polymer, a propylene polymer, a butene polymer, a 4-methyl-1-pentene polymer, a cyclic olefin polymer, and ethylene and propylene. , Butene, 4-methyl-1-pentene, hexene, octene, and other olefins. Further, for example, as a raw material of the copolymer, a compound other than an olefin, for example, an aromatic vinyl compound such as styrene or (meth) acrylic acid (ester) may be used.
Among these, ethylene-based polymers, propylene-based polymers, butene-based polymers, and 4-methyl-1-pentene-based polymers are preferable, and ethylene-based polymers, propylene-based polymers, and 4-methyl-1-pentene-based polymers are preferred. Polymers are more preferred, and depending on the application, 4-methyl-1-pentene polymers are particularly preferred.

The olefin polymer may be synthesized by a conventionally known method, or may be a commercially available product.
There are many reports on the means for obtaining the olefin-based polymer, and they can be adopted without limitation. For example, as a method for obtaining an ethylene polymer having a high molecular weight, International Publication Nos. 2008/01144 and 2008/013144. As a method for obtaining a 4-methyl-1-pentene-based polymer, a method described in WO 2006/054613 or the like can be mentioned.

  Examples of commercially available products of the olefin-based polymer include Hizex, Hizex Million, Miperone, Prime Polypro, TPX (registered trademark), and the like, which are commercially available from the Mitsui Chemicals Group.

  The olefin-based polymer may be a polymer having a melting point and / or a glass transition temperature of 50 to 300 ° C. The above melting point and glass transition temperature are measured by the following method or a method equivalent thereto using the following differential scanning calorimeter (DSC device). Note that another differential scanning calorimeter may be used as long as it is confirmed that the same result as the following apparatus is obtained.

Using an EXSTAR DSC6220 type differential scanning calorimeter manufactured by Hitachi High-Tech Science Co., Ltd., about 5.0 mg of the sample was heated from 30 ° C. in a nitrogen atmosphere to 320 ° C. at a rate of 10 ° C./min. The temperature is maintained for 10 minutes (however, when a polymer that decomposes in a temperature range of 250 ° C. or more and 320 ° C. or less is used, the holding temperature may be appropriately adjusted to be low as usual). Further, the temperature is lowered to 30 ° C. at a rate of 10 ° C./min, maintained at that temperature for 5 minutes, and then raised to 320 ° C. at a rate of 10 ° C./min. In the case of using a polymer, the upper limit temperature at the time of raising the temperature may be appropriately adjusted to be low as usual.) The endothermic peak observed at the time of the second heating is defined as a melting peak, and the temperature at which the melting peak appears is determined as a melting point (Tm). When the melting peak is multimodal, the temperature at which the highest-temperature side melting peak appears is defined as the melting point.
The glass transition temperature (Tg) is sensed when the DSC curve is bent due to a change in specific heat and the base line moves in parallel when the temperature is raised for the second time. The temperature at the intersection of the tangent to the base line at a temperature lower than the bend and the tangent to the point where the inclination is maximum at the bent portion is defined as the glass transition temperature (Tg).

The intrinsic viscosity [η] of the olefin polymer at 135 ° C. in decalin is preferably 0.5 to 20 dl / g, more preferably 0.8 to 18 dl / g, particularly preferably 1 to 15 dl / g. is there.
When the intrinsic viscosity of the olefin polymer is within the above range, the balance between moldability and strength is suitable.

The melt flow rate of the olefin polymer measured according to the ASTM1238 standard varies depending on the melting point of the resin used, as described below. The preferred range of the melt flow rate is 0.1 to 200 g / m 2. 10 minutes. A preferred lower limit is 1 g / 10 minutes, more preferably 3 g / 10 minutes, and still more preferably 5 g / 10 minutes. On the other hand, a preferred upper limit is 150 g / 10 minutes, more preferably 130 g / 10 minutes.
Preferred measurement conditions for the melt flow rate (ASTM1238 standard) are as follows.
190 ° C., 2.16 kg load for ethylene polymer, 230 ° C., 2.16 kg load for propylene polymer, 260 ° C., 5 kg load for 4-methyl-1-pentene polymer In the case of a cyclic olefin polymer, the temperature is 260 ° C. and the load is 2.16 kg.

The film can be manufactured by a known method, and specific examples include extrusion molding (eg, T-die molding), inflation molding, and cast molding (including a case where a spin coating method is used in combination). It can be mentioned as.
Further, the film may be a film obtained by forming a film by these methods and then stretching the film. By performing this stretching, the degree of crystallinity and the transparency in visible light can be increased, or the film can be made porous. When making it porous, the film containing the dispersed fine particles may be stretched.

  The film may be any other polymer, various stabilizers such as an antioxidant, a heat stabilizer, a light stabilizer, a weather stabilizer, an antistatic agent, a hydrophilic agent, and a water repellent, as long as the object of the present invention is not impaired. , A nucleating agent, a slip agent, an anti-blocking agent, an anti-fogging agent, a lubricant, a dye, a pigment, a flame retardant and the like.

The thickness of the film is preferably 1 to 1000 μm, more preferably 5 to 500 μm, and still more preferably 10 to 300 μm.
When the thickness of the film is within the above range, functions such as surface characteristics can be easily imparted while maintaining mechanical characteristics such as film strength. Although it depends on the wavelength of the light beam used and the light absorption characteristics of the olefin polymer, if the film is too thin, it may be difficult to make a fine design such as mainly modifying a part of the surface or the like.

[Modified film]
A functional group containing an atom (α) contained in the radical may be introduced into the film in some cases, and a functional group containing a Group 15 or 16 atom derived from oxygen in the air may be introduced into the film. is there. At this time, atoms (β) contained in the radicals may be introduced into the film.
According to the present method, since it is considered that the atoms (β) are also introduced into the film, the effect of the atoms (β) may be expected in the modified film in some cases.

  It has been reported that when a low molecular weight hydrocarbon compound such as an alkane is modified using the above radical, introduction of a group 17 atom is suppressed. In some cases, it can be introduced into the film together with the atoms. This is thought to be due to the fact that the density of carbon-hydrogen bonds in the film tends to be higher than when denaturing small molecules such as methane and ethane, and because the film interacts with radicals. The present inventors think that the stabilization of the radical may be one of the causes. However, the present invention is not limited by this estimation.

As the functional group containing the atom (α), when the radical contains oxygen, for example, a hydroxy group, a carboxy group, an aldehyde group, a carbonyl group, an ether bond, an ester bond, —C (＝ O) OOH, — O-O-.
When atoms (β) are introduced into the film, the ratio [Cα] / [Cβ] of the total amount of atoms (α) [Cα] and the total amount of atoms (β) [Cβ] to be introduced into the film. Is preferably more than zero, more preferably 0.01, further preferably 0.1, particularly preferably 0.5, and the upper limit is preferably 5000, more preferably 100, and still more preferably 20.
The [Cα] and [Cβ] values are values specified by the XPS method. The measurement is carried out using a product name AXIS-Nova (manufactured by KRATOS) by an ordinary method.

According to this method, it is expected that the surface of the film to be modified can be mainly modified. Therefore, even if the olefin polymer molecules constituting the film are cut or cross-linked during modification, they remain mainly on the film surface, and the effect on the performance inside the film, such as the strength of the film, is minimal. This is advantageous in maintaining the strength of the film.
The surface refers to a region whose depth from the surface of the film is 1/10 or less, more preferably 1/20 or less of its thickness. The depth of the denatured portion can be confirmed by, for example, the XPS method.

According to this method, the entire surface of the film can be modified, only a part of the surface can be modified, or only a part of the surface can be modified.
Since the present method proceeds through light, it is expected that the location mainly exposed to light can be modified.
In addition, if light is applied to only one side of the film, a modified film that has been modified only on one side or a photomask or the like can be used to control a portion that is exposed to light. It is expected that the ratio of the native portion can be freely controlled.

For example, in the modified film, the area of the portion to be modified may be appropriately selected according to a desired use of the modified film, such as a usage form of attaching the modified film to a window or the like, but the entire surface of the modified film may be used. As 100%, a preferred lower limit is preferably 1%, 5%, 10%, 20%, 30%, and 50% in this order, and a preferred upper limit is 100%, and more preferably 90%. The denatured region can be specified by a known method such as the XPS method.
It is considered that the modification proceeds from a radical of a Group 17 element generated by being irradiated with light in the presence of the radical. Therefore, it is considered that denaturation occurs in a portion where the radical contacts the film to be denatured. For example, in the method (I), when the radicals and the film are irradiated with light, the area of the film to be modified that is irradiated with light may be considered to be substantially equivalent to the modified area.
In some cases, the peripheral part irradiated with light or the deep part of the pores that light does not reach may be modified, but the ratio is considered to be small.

  The modified film obtained by this method may be used as it is, or the functional group introduced as described above may be further reacted with other components to enhance the function or change the properties. Good. For example, by using the functional group as a scaffold and reacting with silicone components having various structures, it is possible to impart extremely high releasability.

It is considered that the modified film can be preferably applied to various uses.
When the modified film is a porous film, it is considered to be suitable for, for example, various separator applications such as batteries, filter applications, release films, and the like.
The release film may be, for example, a release film having a laminated structure in which an olefin-based polymer film such as TPX (registered trademark) is bonded to paper or a polyester film. In this case, using the modified film obtained by the present method only on one side, when the modified surface is to be bonded to paper or a polyester film, etc., the adhesive performance with the paper or polyester film or the like is enhanced, and other The surface can also be expected to be an excellent laminated release film that can exhibit release performance.

  Further, even when a film having a complicated surface shape such as a porous film is used as the film, it can be expected that the method can be modified to the finest details. The denaturation by this method is considered to be a denaturation originating from a radical having a simple structure such as a chlorine radical, as described above, so that high mobility can be expected. It is considered that such characteristics can be applied to not only the film surface but also a fine surface of a molded article such as an injection molded article.

  Since the modified film has a small decrease in the molecular weight of the olefin polymer due to the modification, it is possible to easily obtain a modified film having a small decrease in strength and excellent durability in the above-mentioned applications. In addition, since a relatively large number of functional groups can be introduced by the modification, it is expected that the rate of deterioration over time of the performance imparted by the modification is small.

  Another expected application is that it is also expected to be used as a display film by using a photomask in the form of characters or pictures when irradiating light to modify only a predetermined portion and attaching a dye or the like to the modified portion. Is done.

  Hereinafter, examples of the present invention will be described. However, the present invention is not limited to the following examples.

[Example 1]
10 g of sodium chlorite (manufactured by Sigma-Aldrich) and 100 mL of ultrapure water are put in a polycontainer, and sodium chlorite is dissolved in the ultrapure water, and then a 35 to 37% aqueous hydrochloric acid solution (Fujifilm Wako Pure Chemical Co., Ltd.) 1 ml) was added to prepare a mixed solution. The presence of chlorine dioxide radicals in the mixture under these conditions was separately confirmed by the ESR method. This mixed solution was placed in a shallow vat having a size of about 22 cm × 16 cm × 1.5 cm and placed on a net shelf. Then, a TPX film of about 28 cm × 20 cm (poly 4-methyl-1-pentene, manufactured by Mitsui Chemicals, Inc., DX231, 50 μm thickness, melting point: 231 ° C., melt flow rate (ASTM1238 standard, 260 ° C., 5 kg load): (100 g / 10 minutes) was placed on a vat so as not to touch the mixed solution (the state at this time is shown in FIG. 1). The film was irradiated with light having a wavelength of 365 nm at 50 to 70 mW / cm ² for 10 minutes using Hollolight Kaku DC12V manufactured by Py Photonics KK from above the film. Thereafter, using a washing bottle, the entire surface of the film was washed with ultrapure water and then dried under reduced pressure to obtain a modified TPX film.

<Evaluation of hydrophilicity of TPX film>
For each of the untreated TPX film and the modified TPX film, eight EnerDyne pens (each having a Dyne level of 30, 32, 35, 38, 41, and 40) included in a pen set Variity for checking wettability manufactured by Enercon Inc. 44, 48 and 56), a line of about 1 cm was drawn, and the wettability of the ink was visually confirmed. Table 1 shows the results. FIG. 2 shows the state of the film at this time. In addition, above the number of FIG. 2, the state of an oxidized TPX film is shown, and below the number, the state of an untreated TPX film is shown.

Claims (8)

In one molecule, the atom (α) of the element selected from the group 15 element and the group 16 element and the atom (β) of the group 17 element are defined as the number of atoms (α): the number of atoms (β) = 1: 1. Step 1 of irradiating light in the presence of radicals having a ratio of ４4: 1.
A method for producing a modified film obtained by modifying a part or all of an olefin polymer film having a melting point and / or a glass transition temperature of 50 ° C. or more and 300 ° C. or less.   The method for producing a modified film according to claim 1, wherein the step 1 is a step of irradiating the radical with light in the presence of the radical and the film to modify the film.   The method for producing a modified fabric according to claim 1 or 2, wherein the step 1 is a step of irradiating the radical and the film with light in the presence of the radical and the film to modify the film.   The method for producing a modified film according to any one of claims 1 to 3, wherein the thickness of the modified film is 1 to 1000 m.   The method for producing a modified film according to any one of claims 1 to 4, wherein the radical is a chlorine dioxide radical.   The method for producing a modified film according to any one of claims 1 to 5, wherein the olefin-based polymer is a 4-methyl-1-pentene-based polymer.   The method for producing a modified film according to any one of claims 1 to 6, wherein the modified film is a porous film.   The method for producing a modified film according to any one of claims 1 to 7, wherein the modified film is a release film.