JP7133167B2 - Modified fabric production method - Google Patents

Description

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

In recent years, fabrics such as non-woven fabrics and woven fabrics have been used in various fields.
As the fabric, a fabric made of polyolefin or the like, which is excellent in chemical stability, etc., is used. Therefore, various affinity treatments are performed.

Known affinity treatments include modification of resins with unsaturated carboxylic acids such as maleic anhydride or acid anhydrides thereof (eg, Patent Document 1), corona discharge treatment, plasma treatment and other surface treatments.

Japanese Patent Application Laid-Open No. 2003-247157

The fabrics, particularly fabrics used for sanitary materials, are sometimes required to have texture, specifically, flexibility.
It was found that although fabrics made from resins modified with maleic anhydride or the like can be made hydrophilic, the fabrics suffer from a decrease in bending flexibility, presumably due to the fact that the fabrics become stiffer due to the interaction of the modified portions. rice field. In other words, it was found that there is a trade-off relationship between flexibility and hydrophilicity when modifying a resin with maleic anhydride or the like.

In addition, when the resin is modified or surface-treated, the molecular weight of the polymer constituting the fabric tends to decrease, a cross-linking reaction occurs, and the polymer tends to deteriorate or yellow. It was found that there is a limit to the amount of functional groups introduced by these methods.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a modified fabric capable of retaining the texture (flexibility) while efficiently modifying the fabric.

As a result of the research conducted by the present inventors, it was found that the above problems can be solved by the following configuration example. A configuration example of the present invention is as follows.

[1] Atoms (α) of elements selected from group 15 elements and group 16 elements and atoms (β) of group 17 elements in one molecule, number of atoms (α): number of atoms (β) = comprising step 1 of irradiating with light in the presence of radicals in a ratio of 1:1 to 4:1;
A method for producing a modified fabric by modifying a fabric containing a polymer A having a melting point and/or a glass transition temperature of 50° C. or more and 400° C. or less selected from an olefin polymer, a polyester polymer and a polyimide polymer. .

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

[4] The method for producing a modified fabric according to any one of [1] to [3], wherein the fabric is a nonwoven fabric.

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

[6] The method for producing a modified fabric according to any one of [1] to [5], wherein the olefin polymer is a propylene polymer.

[7] The method for producing a modified cloth according to any one of [1] to [6], wherein the cloth is a sanitary material.

According to the production method of the present invention, it is possible to efficiently produce a modified fabric, and more specifically, to provide a modified fabric that can retain its texture (flexibility) while mainly modifying its surface.
In addition, according to the production method of the present invention, it is possible to suppress the decrease in the molecular weight of the polymer, the cross-linking reaction, the deterioration, the yellowing, the decrease in the strength of the fabric, etc., which the fabric before modification had. While making use of the characteristics, it is possible to impart the effect of modification.

FIG. 1 is a schematic diagram showing the state when the nonwoven fabric was denatured in Examples. FIG. 2 is a schematic diagram showing a method for evaluating the hydrophilicity of nonwoven fabrics in Examples.

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

≪Manufacturing method of modified fabric≫
The method for producing a modified cloth according to the present invention (hereinafter also referred to as "the present method") comprises an olefin-based polymer, a polyester-based polymer and a polyimide-based polymer having a melting point and/or a glass transition temperature of 50°C. A method for producing a modified fabric by modifying a fabric containing a polymer A having a temperature of 400 ° C. or higher,
Number of atoms (α): number of atoms (β) = 1:1 It includes step 1 of irradiating in the presence of radicals with a ratio of ~4:1.

According to this method, it is possible to efficiently produce a modified fabric, and more specifically, to easily obtain a modified fabric that can maintain its texture (bending flexibility) while mainly modifying its surface. For example, sanitary materials such as disposable diapers may require wettability only at the portions that come into contact with the skin. According to this method, mainly only the vicinity of the surface of the polymer A (fabric) or only specific locations can be modified (modified), so it can be said that the locations that require modification can be efficiently modified. By doing so, it is possible to enhance the modification effect while suppressing the decrease in the strength of the fabric before modification.
The stiffness is a measure of hardness that can be judged by whether or not the fabric sag when one end of the fabric of a predetermined length is lifted.

According to this method, the polymer A is efficiently modified (e.g., oxidation treatment) by a very simple method of only irradiating the radical with light, and even under extremely mild conditions such as normal temperature and normal pressure. can do. Furthermore, according to this method, for example, the polymer A 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 step 1, atoms (α) of elements selected from group 15 elements and group 16 elements and atoms (β) of group 17 elements are added to one molecule, and the number of atoms (α): the number of atoms (β) It is a step of irradiating light in the presence of radicals contained in a number ratio of 1:1 to 4:1.
The step 1 may be carried out in the presence of the radical, preferably a step of irradiating the radical in the presence of the radical, more preferably in the presence of the radical and the polymer A. It is a step of irradiating light on. The polymer A used at this time may be a fabric containing the polymer A, or may be a filamentous polymer or the like that is a raw material for fabric manufacturing, but the fabric containing the polymer A is used. is preferred.

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

Atom (α) is preferably nitrogen, oxygen or sulfur, with oxygen being particularly preferred.
The atom (β) preferably includes chlorine, bromine and iodine, with chlorine and bromine being preferred. Among these, chlorine is more preferable because chlorine-containing radicals are easily available. When radicals containing chlorine are used, light containing ultraviolet rays is preferable as irradiation light, and when radicals containing bromine or iodine are used, it is considered that light with a longer wavelength than ultraviolet rays can also be used. Therefore, bromine and iodine are preferable depending on the situation, such as when considering the degree of freedom of light selection or when the polymer A may be photodegraded.

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

A chlorine dioxide radical is preferable as the radical.
When light irradiation is performed in the presence of chlorine dioxide radicals (ClO ₂ ·), for example, it is thought 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 according to the radicals to be used. Specifically, it is possible to select a wide range from the infrared region to the ultraviolet region, and it is, for example, 200 nm or more and, for example, 800 nm or less.
Although the light irradiation time is not particularly limited, it is, for example, 1 minute or more and, for example, 1000 hours or less.

The light source for the light irradiation is not particularly limited, but natural light such as sunlight can be used from the viewpoint of convenience. Further, for example, instead of or in addition to the natural light, a light source such as a xenon lamp, a halogen lamp, a fluorescent lamp, or a mercury lamp may be appropriately used. Furthermore, if necessary, a filter that cuts wavelengths other than the required wavelength may be used as appropriate.

The temperature, pressure, and atmosphere in performing Step 1 are not particularly limited, but the reaction temperature is, for example, 0° C. or higher and, for example, 100° C. or lower, and the pressure is, for example, 0.1 MPa or higher and 100 MPa or lower. The atmosphere includes, for example, an air atmosphere and an inert gas atmosphere.
For example, as shown in the examples below, this method is carried out in the atmosphere at normal temperature (eg, 5 to 35° C.) and normal pressure (atmospheric pressure) without any heating, pressurization, pressure reduction, etc. is also possible.

The light irradiation is performed on radicals existing in the aqueous phase, the organic phase and/or the gas phase. When emphasis is placed on reducing the load on the environment and the effects on the human body, it is preferable to perform the treatment on radicals present in the water phase or the gas phase.

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.
Although the organic solvent is not particularly limited, examples thereof include hydrocarbon solvents and halogenated solvents.
One kind of the organic solvent may be used, or two or more kinds thereof may be used.

Examples of the hydrocarbon solvent include, but are not limited to, n-hexane, cyclohexane, benzene, toluene, o-xylene, m-xylene, and p-xylene.

Examples of the halogenated solvent include, but are not limited to, methylene chloride, chloroform, carbon tetrachloride, carbon tetrabromide, and fluorous solvents.

The fluorous solvent refers to 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 hydrogen atoms in the hydrocarbon are substituted with fluorine atoms.

Examples of the fluorous solvent include CF ₃ —(CF ₂ ) _n —CF ₃ (n is 4 to 7), N—((CF ₂ ) _n CF ₃ ) ₃ (n is 1 or 4), hexafluorobenzene , 1-(trifluoromethyl)undecafluorocyclohexane, 1-(trifluoromethyl)pentafluorobenzene, octadecafluorodecahydronaphthalene, among which CF ₃ (CF ₂ ) ₄ CF ₃ is preferred. .

A fluorous solvent has the advantage of suppressing or preventing side reactions, for example, because the solvent itself has low reactivity. The side reactions include, for example, an oxidation reaction of the solvent, a hydrogen abstraction reaction of the solvent by radicals, and a chlorination reaction.

The aqueous phase may contain components other than the radicals and water, and the organic phase may contain components other than the radicals and the organic solvent.
Examples of the other component include, but are not particularly limited to, the radical generating source, Bronsted acid, Lewis acid, and oxygen (O ₂ ).
Each of these may be used alone or in combination of two or more.
Said other ingredients may be dissolved in the aqueous phase and/or the organic phase, but they do not have to be dissolved.
In addition, one substance may serve as both the Lewis acid and the Bronsted acid. The term "Lewis acid" refers to a substance that acts as a Lewis acid against the above radical generation source.

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 used. Salts of chlorous acid are not particularly limited, and examples thereof include metal salts. Examples of the metal salt include alkali metal salts, alkaline earth metal salts and rare earth salts.
More specifically, the chlorine dioxide radical generation source 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 preferable from the viewpoint of cost, ease of handling, and the like.

Although the concentration of the radical generation source in the aqueous phase and/or organic phase is not particularly limited, it is, for example, 0.0001 mol/L or more and 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 substances include ammonium ions and organic acids (eg, carboxylic acids).
The inorganic substance may contain one or both of metal ions and non-metal ions. The metal ions may contain one or both of typical metal ions and transition metal ions.
The inorganic substance includes, for example, alkaline earth metal ions (e.g., Ca ²⁺ ), rare earth ions, Mg ²⁺ , Sc ³⁺ , Li ⁺ , Fe ²⁺ , Fe ³⁺ , Al ³⁺ , silicate ions and It may be at least one selected from the group consisting of borate ions.
The alkaline earth metal ions include, for example, calcium, strontium, barium or radium ions, more specifically Ca ²⁺ , Sr ²⁺ , Ba ²⁺ and Ra ²⁺ .
The term "rare earth" is a general term for a total of 17 elements, including two elements, scandium and yttrium, and 15 elements (lanthanoids) from lanthanum to lutetium. Examples of rare earth ions include trivalent cations.

Further, when the Lewis acid is an ion, the Lewis acid may be a substance having a counter ion of the ion, and the counter ion is, for example, trifluoromethanesulfonate 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 , phosphite ion.

Also, 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 . In addition, 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. Although the upper limit of the Lewis acidity is not particularly limited, it is, for example, 20 eV or less. The Lewis acidity is described, for example, in Ohkubo, K.; Fukuzumi, S. Chem. Eur. J., 2000, 6, 4532, J. AM. CHEM. SOC. Org. Chem. 2003, 68, 4720-4726.

The Bronsted acid is not particularly limited, and examples thereof include inorganic acids and organic acids. Specific examples include trifluoromethanesulfonic acid, trifluoroacetic acid, acetic acid, hydrofluoric acid, hydrochloric acid, bromo Hydrochloric acid, hydroiodic acid, sulfuric acid, sulfurous acid, nitric acid, nitrous acid, phosphoric acid, phosphorous acid.
The acid dissociation constant pK _a of the Bronsted acid is, for example, 10 or less. Although the lower limit of the pK _a is not particularly limited, it is -10 or more, for example.

The concentration of at least one of the Lewis acid and Bronsted acid in the aqueous phase and/or the organic phase is not particularly limited and can be set as appropriate. is.

For example, oxygen (O ₂ ) can be dissolved in the aqueous and/or organic phase by blowing air or oxygen gas through the aqueous and/or organic phase. At this point, for example, the aqueous phase and/or the organic phase may be saturated with oxygen (O ₂ ).
When the water phase and/or the organic phase contain oxygen (O ₂ ), for example, the modification (oxidation reaction) of the fabric can be promoted.

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

Although the radical generation step is not particularly limited, for example, the radical generation source (eg, chlorous acid or a salt thereof) is dissolved in water and allowed to stand, and the radicals are naturally generated from the radical generation source. can be done. 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 radicals. Further, for example, the radicals can be generated by irradiating an aqueous phase in which the radical generating source is dissolved in water with light. This light irradiation may be the light irradiation in step 1, that is, the light irradiation may be performed on the radicals while generating the radicals.

For example, a mechanism (mechanism) for generating chlorine dioxide radicals from chlorite ions is presumed as shown in Scheme 1 below. However, Scheme 1 below is an example of a presumed mechanism and does not limit the present invention in any way.
The first (upper) reaction formula in Scheme 1 below shows the disproportionation reaction of chlorite ion (ClO ₂ ⁻ ), and at least one of Lewis acid and Bronsted acid is present in this reaction system. , the equilibrium tends to shift to the right.
The second (middle) reaction formula in Scheme 1 below shows a dimerization reaction, in which hypochlorite ions (ClO ⁻ ) generated in the disproportionation reaction react with chlorite ions to form dioxide. Chlorine (Cl ₂ O ₂ ) is produced. This reaction is thought 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 produced in the dimerization reaction reacts with chlorite ions to produce chlorine dioxide radicals.

Further, when the polymer A has a carbon-hydrogen single bond, the reaction proceeds at the carbon-hydrogen single bond portion. mechanism).

<Deformation of fabric>
In this method, the fabric containing the polymer A is modified. In the present invention, "the fabric containing the polymer A is modified" means the polymer A before performing the step 1 (hereinafter also referred to as "unmodified polymer". The product containing this unmodified polymer Cloth is also referred to as “unmodified cloth”) and the polymer contained in the modified cloth obtained by this method, the polymer contained in the modified cloth is modified compared to the unmodified polymer. It does not necessarily mean that the unmodified fabric itself is modified, but includes, for example, modifying the polymer A filament that is the raw material of the unmodified fabric.

The modification method is not particularly limited. Specifically, the modification method includes a method (I) of irradiating light in the presence of the radical and the polymer A [the step 1 is performed by irradiating the radical in the presence of the radical and the fabric. In the case of the step of irradiating with light] is a preferable method, method (II) in which the system subjected to the step 1 and the polymer A are brought into contact may also be performed.
The polymer A used here may be a fabric containing the polymer A, or may be a polymer such as a filament that is a raw material for the fabric, but is a fabric containing the polymer A. is preferred.

The method (I) is a method of irradiating the polymer A with light [the step 1 is a step of irradiating the radicals and the polymer A, particularly the fabric, with light in the presence of the radicals and the fabric. is also preferable.
In this case, the radicals and the polymer A may be separately irradiated with light, but it is preferable, for example, to irradiate the radicals and the polymer A simultaneously with light from one light source.

The methods (I) and (II) may be, for example, liquid phase methods in which the polymer A is brought into contact (immersion) with an aqueous phase and/or an organic phase containing the radicals, and the aqueous phase containing the radicals and / Or a gas phase method may be performed without contacting the organic phase and the polymer A, or a gas phase method may be performed in a gas phase containing the radical and the polymer A. As the polymer A, for example In the case of using filaments or fabrics having hygroscopicity, etc., or in the case of remaining solvents and the like becoming a problem, the vapor phase method is preferable depending on the situation.

When the fabric or filament to be modified exists in an aqueous phase or an organic phase, the amount of the fabric or filament to be modified in the aqueous phase or organic phase is particularly Although not limited, it is, for example, 1 g/L or more and, for example, 10 g/L or less.

In some cases, the modification introduces a functional group containing the atom (α) contained in the radical into the polymer A. sometimes At this time, the atom (β) contained in the radical may also be introduced into the polymer A.
According to this method, it is thought that the atom (β) is also introduced into the polymer A in this way, and therefore the effect of the atom (β) may be expected in the modified fabric.

It has been reported that introduction of Group 17 atoms is suppressed when modifying low-molecular-weight hydrocarbon compounds such as alkanes using the radicals. In some cases, it can be introduced into the polymer A together with atoms. This is because the existence density of carbon-hydrogen bonds in polymer A tends to be higher than in the case of modifying low-molecular-weight substances such as methane and ethane, and the interaction between polymer A and radicals The present inventors believe that one reason for this is that radicals may be stabilized by their action. However, this speculation does not limit the present invention.

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

According to this method, it is expected that the surface of the polymer A to be modified can be mainly modified. Therefore, when the polymer A to be modified is a filament containing the polymer A or a filament that is a raw material of the fabric, the surface of the filament that constitutes the fabric or the filament that is to be modified can be mainly denatured.
According to this, even if polymer A molecules are cut or crosslinked during modification, they remain near the surface of polymer A, and the performance of the inside of the filament related to the performance such as the strength of polymer A is affected. Since the influence is considered to be minimized, it is advantageous in terms of maintaining the strength of the fabric and filaments.
The surface is more preferably 1/10 or less of the thickness (radius in the case of a filament) of the shape from the surface of the fabric containing the polymer A or the filament that is the raw material for the fabric. means a region of 1/20 or less. The depth of this denatured portion can be confirmed by, for example, the XPS method.

According to this method, when the polymer A to be modified is a fabric containing the polymer A or a filamentous material used as a raw material for fabric manufacturing, the entire surface of the polymer A can be modified. However, part of the surface of the polymer A can also be modified. Further, when a cloth containing the polymer A is used as the polymer A to be modified, the entire surface of the cloth can be modified, or only a part of the surface can be modified.
According to this method, modification progresses through light, so it is expected that the site exposed to light, that is, the surface of polymer A can be mainly modified.
In addition, if only one surface of the fabric is irradiated with light, it is possible to denature only a specific portion by controlling the portion exposed to the light using a modified cloth that has been denatured only on the one side, or a photomask or the like. It is also expected that the ratio of moieties to native moieties can be freely controlled.

For example, the area of the modified portion may be appropriately selected according to the desired application of the modified cloth, such as when the cloth of the present invention is used in a form such as bonding to an injection molded article. Taking the whole as 100%, preferred lower limits are in the order of 1%, 5%, 10%, 20%, 30% and 50%, and preferred upper limits are 100%, more preferably 90%. Denatured regions can be identified by known methods such as the XPS method.
It is considered that the modification progresses with radicals of the group 17 element generated when the radicals are exposed to light as a starting point. Therefore, it is considered that modification occurs at the portion where the radical comes into contact with the polymer A to be modified. For example, in the method (I), when the radical and the polymer (A) are irradiated with light, the irradiated area of the polymer A to be modified and the modified area are considered to be substantially equivalent. may be possible.
Peripheral areas irradiated with light and deep layers of pores where light does not reach may be denatured, but the rate is small.

[Polymer A]
The polymer A is a polymer selected from olefin-based polymers, polyester-based polymers and polyimide-based polymers, and has a melting point and/or a glass transition temperature of 50° C. or higher and 400° C. or lower. .

The olefin-based polymer is not particularly limited, but examples include ethylene-based polymers, propylene-based polymers, butene-based polymers, 4-methyl-1-pentene-based polymers, cyclic olefin-based polymers, ethylene, and propylene. , butene, 4-methyl-1-pentene, hexene, and octene. Further, for example, compounds other than olefins, such as aromatic vinyl compounds such as styrene, and (meth)acrylic acid (esters) may be used as raw materials for the copolymer.
Among these, ethylene-based polymers, propylene-based polymers, butene-based polymers, and 4-methyl-1-pentene-based polymers are preferred, and ethylene-based polymers, propylene-based polymers, and 4-methyl-1-pentene-based polymers are preferred. Polymers are more preferred, and propylene polymers are particularly preferred.

Examples of the polyester polymer include, but are not limited to, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polylactic acid, and copolymers thereof.

The polyimide polymer is not particularly limited, but includes, for example, the polymers described in JP-A-2013-256732, JP-A-2011-132611, and JP-A-2009-228190.

The polymer A may be other polymers, antioxidants, heat stabilizers, light stabilizers, various stabilizers such as weather stabilizers, antistatic agents, hydrophilic agents, repellents, etc., as long as the objects of the present invention are not impaired. Additives such as liquid agents, nucleating agents, slip agents, anti-blocking agents, anti-fogging agents, lubricants, dyes, pigments, natural oils, synthetic oils, antibacterial agents and flame retardants may be included.

The polymer A may be a polymer having a melting point and/or a glass transition temperature of 50 to 400.degree. The melting points and glass transition temperatures mentioned above are those measured by the following method or an equivalent method using the following differential scanning calorimeter (DSC apparatus). Other differential scanning calorimeters may be used as long as they are confirmed to give results equivalent to those of the apparatus described below.

Using a Diamond DSC (3) type differential scanning calorimeter manufactured by PerkinElmer, about 5.0 mg of a sample was heated from 30°C at a rate of 10°C/min under a nitrogen atmosphere to a predetermined temperature (olefin polymer 320° C., polyester polymer: 350° C., polyimide polymer: 420° C.) and maintained at that temperature for 10 minutes. (However, when using a polymer that decomposes when heated to the predetermined temperature, the temperature to be held may be appropriately adjusted to a lower temperature in the usual manner.) Further cooled to 30°C at a cooling rate of 10°C/min. After holding the temperature for 5 minutes, the temperature is increased to the same temperature as the predetermined temperature at a temperature increase rate of 10° C./min. The endothermic peak observed during the second temperature rise is defined as the melting peak, and the temperature at which the melting peak appears is determined as the melting point (Tm). When the melting peaks are multimodal, the temperature at which the highest melting peak appears is taken as the melting point.
Further, the glass transition temperature (Tg) is sensed in the form that the DSC curve bends due to the change in the specific heat during the second temperature rise and the baseline shifts in parallel. The temperature at the intersection of the tangent line of the baseline at a temperature lower than the bend and the tangent line of the point where the inclination is maximum at the bend is defined as the glass transition temperature (Tg).

The intrinsic viscosity [η] of the polymer A in decalin at 135° C. is preferably 0.5 to 20 dl/g, more preferably 0.8 to 18 dl/g, particularly preferably 1 to 15 dl/g.

When the polymer is an olefin polymer, the melt flow rate measured according to the ASTM 1238 standard varies depending on the melting point of the resin used, as described later, but the preferred range of the melt flow rate is 0. .1 to 600 g/10 min. A preferred lower limit is 1 g/10 minutes, more preferably 3 g/10 minutes, and even more preferably 5 g/10 minutes. On the other hand, the upper limit is preferably 500 g/10 minutes, more preferably 400 g/10 minutes.
Preferred measurement conditions for the melt flow rate (ASTM1238 standard) are as follows.
190° C., 2.16 kg load for ethylene polymers, 230° C., 2.16 kg load for propylene polymers, 260° C., 5 kg load for 4-methyl-1-pentene polymers , 260° C. and 2.16 kg load in the case of a cyclic olefin polymer.

[Thread-state polymer A]
Examples of the thread-like polymer A include fibrous polymer A. Such a fibrous polymer A can be produced by a conventionally known method. Specifically, it can be obtained by spinning from a pellet-like polymer A. During this spinning, the polymer and the additive may be used to produce a fiber containing the additive.

[Fabric containing polymer A]
Examples of the fabric containing the polymer A include fabrics obtained by weaving, depositing, or knitting the polymer A in the form of threads. The fabrics used in the present invention include woven fabrics, nonwoven fabrics, and knitted fabrics, and also include products such as sanitary materials such as disposable diapers and sanitary products. Among these, nonwoven fabrics are preferable because the effects of the present invention are more exhibited.

As the nonwoven fabric, conventionally known nonwoven fabrics can be used without particular limitation. The structure and manufacturing method of the nonwoven fabric include, for example, those described in WO 2004/065680 and JP-A-2002-302862.

[Modified fabric]
The modified fabric obtained by this method tends to maintain the properties of the polymer A, particularly the fabric and fiber, before modification. For example, when a nonwoven fabric is used, functions such as hydrophilicity can be imparted while maintaining the desired soft touch.
On the other hand, modified nonwoven fabrics using conventional modification techniques such as maleic anhydride tend to be hard and poor in flexibility. It can be speculated that this is due to the interaction of the denaturing moieties.

The modified fabric obtained by this method may be used as it is, or the functional groups introduced as described above may be reacted with other components to enhance the function or change the properties. good too. For example, the above functional group may be used as a scaffold to bond with a more hydrophilic group or hydrophilic material.

The modified fabric can be preferably applied to various uses, and is particularly suitable for sanitary materials. Examples include disposable diapers (for example, for infants and the elderly), sanitary products, and products such as drug sheets and tapes for treating wounds (for example, Band-Aids [registered trademark]). Since these products come into direct contact with the skin and wounds, in addition to being hygienic, they are usually required to have good texture (flexibility) and releasability.
In addition to the sanitary materials, the modified fabric can be used for applications in which conventional woven fabrics, nonwoven fabrics, and knitted fabrics have been used, such as filters, separators, packaging materials, clothes, soundproofing materials, thickeners, and various membranes. It can also be used in many applications such as supports.

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

[Example 1]
Put 10 g of sodium chlorite (manufactured by Sigma-Aldrich) and 100 mL of ultrapure water in a plastic container, dissolve the sodium chlorite in the ultrapure water, and then add 35 to 37% hydrochloric acid aqueous solution (Fujifilm Wako Pure Chemical ( (manufactured by Co., Ltd.) 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 mixture was placed in a shallow vat of approximately 22 cm x 16 cm x 1.5 cm high and placed on a rack. Next, a polypropylene nonwoven fabric (SYNTEX PK-108, manufactured by Mitsui Chemicals, Inc., melting point: about 160° C.) of about 32 cm×21 cm was placed on the vat so as not to touch the mixture. Further, a glass bat of about 33 cm×24 cm×height 3 cm was placed over the polypropylene nonwoven fabric as shown in FIG. Light with a wavelength of 365 nm was irradiated from the upper part of the glass vat at 50 to 70 mW/cm ² for 30 minutes with Hololite Kaku DC12V manufactured by Piphotonics. After that, the mixed solution was prepared again and replaced with the mixed solution inside the shallow vat after light irradiation. Further, light was irradiated in the same manner as described above, except that the surface of the nonwoven fabric placed on the bat was reversed. Thereafter, the nonwoven fabric was dried under reduced pressure to obtain a modified nonwoven fabric.
The resulting modified nonwoven fabric had the same degree of bending resistance as the untreated nonwoven fabric (Syntex PK-108).

<Hydrophilic evaluation of nonwoven fabric>
An untreated nonwoven (Syntex PK-108) and the modified nonwoven were each fixed on a 45° inclined plate. Next, about 1 mL of tap water was dropped by a pipette from about 50 mm above the surface of each nonwoven fabric, and it was confirmed whether or not each nonwoven fabric would absorb water. Table 1 shows the results.

As described above, the modified nonwoven fabric obtained by this method had a good balance between hydrophilicity and bending resistance, which can be considered as an alternative index of texture. The modified nonwoven fabric is considered to be suitable for sanitary materials such as diapers, sanitary products, and cut protection products, as well as filters, clothing, packaging materials, membrane supports, and the like. There is a high possibility that it is particularly suitable for sanitary materials.

Claims (7)

Number of atoms (α): number of atoms (β) = 1:1 comprising step 1 of irradiating in the presence of radicals in a ratio of ~4:1;
A method for producing a modified fabric by modifying a fabric containing a polymer A having a melting point and/or a glass transition temperature of 50° C. or more and 400° C. or less selected from an olefin polymer, a polyester polymer and a polyimide polymer. and
the atom (α) is an oxygen atom, the atom (β) is at least one atom selected from chlorine, bromine and iodine,
The step 1 is a step performed without bringing the polymer A into contact with the aqueous phase and/or organic phase containing the radicals.
A method for producing a modified fabric . 2. The method for producing a modified fabric according to claim 1, wherein said step 1 is a step of irradiating said radical with light in the presence of said radical and said fabric. 3. The method for producing a modified cloth according to claim 1, wherein said step 1 is a step of irradiating said radicals and said cloth with light in the presence of said radicals and said cloth. The method for producing a modified fabric according to any one of claims 1 to 3, wherein the fabric is a nonwoven fabric. The method for producing modified fabric according to any one of claims 1 to 4, wherein the radical is a chlorine dioxide radical. The method for producing a modified fabric according to any one of claims 1 to 5, wherein the olefin polymer is a propylene polymer. The method for producing a modified fabric according to any one of claims 1 to 6, wherein the fabric is a sanitary material.

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