WO2022176856A1

WO2022176856A1 - Nonwoven fabric, nonwoven fabric layered body, filter, and liquid-blocking article

Info

Publication number: WO2022176856A1
Application number: PCT/JP2022/005976
Authority: WO
Inventors: 秀超北山; 康三飯場; 尚貴山岸; 直永井
Original assignee: 三井化学株式会社
Priority date: 2021-02-22
Filing date: 2022-02-15
Publication date: 2022-08-25
Also published as: JPWO2022176856A1

Abstract

This nonwoven fabric contains fibers, the fibers comprising, in terms of the fiber total mass, at least 80 mass% of a thermoplastic resin and 0.01 to 20 mass% of at least one selected from a specific silylated polyolefin and a derivative thereof.

Description

Nonwovens, nonwoven laminates, filters and liquid barrier articles

The present disclosure relates to nonwoven fabrics, nonwoven laminates, filters and articles for liquid shielding.

In recent years, nonwoven fabrics have been used in various fields, and their applications include filters such as liquid filters and air filters, sanitary materials, medical materials, agricultural coating materials, civil engineering and construction materials, oil adsorbents, automotive materials, electronic It covers a wide range of materials, separators, clothing, packaging materials, and sound absorbing materials.

Generally, filters are used for the purpose of collecting and removing foreign substances (for example, fine particles) present in fluids such as liquids and gases. Non-woven fabrics are provided as filter media for such filters. Fibers of thermoplastic resins such as polypropylene, polyethylene, and polyester are known as fibers constituting nonwoven fabrics. For example, Patent Literature 1 describes a non-woven fabric filter material for an air filter that includes composite short fibers having a core made of polyester and a sheath made of polypropylene.

A filter equipped with a nonwoven fabric as a filter medium captures and removes foreign matter (for example, fine particles) contained in fluids such as liquids and gases with the network structure of the nonwoven fabric. Therefore, as the filter is used for a longer period of time, the collected foreign matter accumulates in the filter material. As a method for removing the foreign matter accumulated in the filter, there is a method of scraping it with a brush or the like, and a method of flowing washing water, washing air, etc. in the direction opposite to the filtering direction (hereinafter also referred to as "backwashing"). Are known. For example, Patent Literature 2 describes a filter equipped with a backwashing device.

JP 2018-061924 A JP 2018-23925 A

However, when removing foreign matter accumulated in a filter having a nonwoven fabric as a filter medium, the nonwoven fabric may be damaged by a method of scraping it with a brush or the like. In addition, in backwashing, a certain amount of foreign matter remains in the filter medium, and the service life of the filter may be shortened.
In order to reduce foreign matter remaining after backwashing, the present inventors tried to add alkoxysilane to the fibers constituting the nonwoven fabric, which is a filter medium, to lower the surface free energy. However, in this method, it was found that the backwashing performance may deteriorate if the filter is used for a long time. Therefore, a nonwoven fabric that can be used as a filter medium for filters and is excellent in backwashability and maintenance is desirable.

As mentioned above, non-woven fabrics are used in a variety of fields, and are also used for applications that require liquid shielding, such as medical materials such as protective clothing and medical gowns. Nonwoven fabrics used for such applications are desired to have high water pressure resistance and to suppress deterioration of water pressure resistance over time.

An object of one embodiment of the present disclosure is to provide a nonwoven fabric that can be applied as a filter medium of a filter and has excellent backwashability and maintainability, or a nonwoven fabric laminate including the nonwoven fabric, a filter, and a liquid shielding article. .
Another embodiment of the present disclosure aims to provide a nonwoven fabric having excellent water pressure resistance and maintenance properties, or a nonwoven fabric laminate, filter, and liquid shielding article including the nonwoven fabric.

The present disclosure includes the following embodiments.
<1> A nonwoven fabric containing fibers,
The fibers are
80% by mass or more of the thermoplastic resin with respect to the total mass of the fibers,
A reaction product (1 molecule Silylated polyolefins and derivatives thereof, excluding the reaction product of the silicon-containing compound having two or more SiH groups in the above and the vinyl group-containing compound having an average of 2.0 or more vinyl groups per molecule. 0.01% by mass to 20% by mass of at least one selected from the total mass of the fiber,
A nonwoven fabric containing
—Si(R ¹ )HY ¹ — (1)
(In formula (1), R ¹ represents a hydrogen atom, a halogen atom or a hydrocarbon group, Y ¹ represents O, S or NR ³⁰ , and R ³⁰ represents a hydrogen atom or a hydrocarbon group.)
<2> The nonwoven fabric according to <1>, wherein the thermoplastic resin contains at least one selected from the group consisting of polyolefins, polyamides and polyesters.
<3> The nonwoven fabric according to <1>, wherein the thermoplastic resin contains polypropylene.
<4> The nonwoven fabric according to any one of <1> to <3>, wherein the vinyl group-containing compound has a structure represented by the following formula (4).
A-CH=CH ₂ (4)
(In formula (4), A represents a polymer chain containing a structure derived from an α-olefin having 2 to 50 carbon atoms.)
<5> The nonwoven fabric according to <4>, wherein A is an ethylene homopolymer chain.
<6> The nonwoven fabric according to any one of <1> to <5>, wherein the fibers have an average fiber diameter of 4.0 μm or less.
<7> The nonwoven fabric according to any one of <1> to <6>, including a meltblown nonwoven fabric.
<8> A nonwoven fabric layer A which is the nonwoven fabric according to any one of <1> to <7>;
A nonwoven fabric laminate comprising a layer B other than the nonwoven fabric layer A.
<9> The nonwoven fabric laminate according to <8>, wherein the layer B comprises a spunbond nonwoven layer.
<10> Including a nonwoven fabric layer A which is the nonwoven fabric according to any one of <1> to <7>, a layer B other than the nonwoven fabric layer A, and a layer C other than the nonwoven fabric layer A , the layer B, the nonwoven fabric layer A and the layer C arranged in this order, the nonwoven fabric laminate according to <8>.
<11> The nonwoven fabric laminate according to <10>, wherein at least one of the layer B and the layer C comprises a spunbond nonwoven fabric layer.
<12> A filter comprising the nonwoven fabric according to any one of <1> to <7> or the nonwoven fabric laminate according to any one of <8> to <11>.
<13> A liquid shielding article comprising the nonwoven fabric according to any one of <1> to <7> or the nonwoven fabric laminate according to any one of <8> to <11>.

An embodiment of the present disclosure can provide a nonwoven fabric that can be applied as a filter medium of a filter and has excellent backwashability and maintainability, or a nonwoven fabric laminate, filter, and liquid shielding article containing the nonwoven fabric.
Other embodiments of the present disclosure can provide nonwoven fabrics, or nonwoven fabric laminates, filters, and liquid shielding articles comprising the nonwoven fabrics, which have excellent water pressure resistance and maintenance properties.

The nonwoven fabrics and filters of the present disclosure are described in detail below.
In the present disclosure, a numerical range indicated using "to" indicates a range including the numerical values before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described stepwise in this specification, the upper limit or lower limit described in a certain numerical range may be replaced with the upper limit or lower limit of another numerical range described stepwise. Moreover, in the numerical ranges described in this specification, the upper limit or lower limit described in a certain numerical range may be replaced with the values shown in the examples.
In the present disclosure, when there are multiple substances corresponding to each component in the composition, the amount of each component in the composition is the total amount of the multiple substances present in the composition unless otherwise specified. means.
In the present disclosure, "mass" and "weight" are synonymous, and "mass%" and "weight%" are synonymous.
In the present disclosure, a combination of two or more preferred aspects is a more preferred aspect.

《Nonwoven fabric》
The nonwoven fabric of the present disclosure is a nonwoven fabric containing fibers, and the fibers contain a thermoplastic resin in an amount of 80% by mass or more with respect to the total mass of the fibers, and a structural unit represented by the following formula (1). A reaction product of the contained silicon-containing compound and a vinyl group-containing compound having a number average molecular weight of 100 or more and 500,000 or less as determined by the GPC method (however, the above silicon-containing compound having two or more SiH groups in one molecule and the reaction product with the vinyl group-containing compound having an average of 2.0 or more vinyl groups per molecule), at least one selected from silylated polyolefins and derivatives thereof, in the total mass of the fiber It is a nonwoven fabric containing 0.01% by mass to 20% by mass.
—Si(R ¹ )HY ¹ — (1)
(In formula (1), R ¹ represents a hydrogen atom, a halogen atom or a hydrocarbon group, Y ¹ represents O, S or NR ³⁰ , and R ³⁰ represents a hydrogen atom or a hydrocarbon group.)
In the present disclosure, the silylated polyolefins and derivatives thereof are collectively referred to as "specific silylated polyolefins" as appropriate.

The nonwoven fabric of the present disclosure is a nonwoven fabric containing fibers, the fibers containing a thermoplastic resin in an amount of 80% by mass or more based on the total mass of the fibers, and a specific silylated polyolefin in an amount of 80% by mass or more based on the total mass of the fibers. , 0.01% by mass or more and 20% by mass or less.
The nonwoven fabric of the present disclosure may be a nonwoven fabric composed of one layer of the specific nonwoven fabric described above, or may be a nonwoven fabric composed of two or more layers of the specific nonwoven fabric described above.
The nonwoven fabric of the present disclosure is suitably included in filters such as liquid filters and air filters. That is, the nonwoven fabric of the present disclosure can be suitably used as a filter medium for filters.

The present inventors tried to add alkoxysilane to the fibers constituting the nonwoven fabric to reduce the surface free energy in order to reduce the amount of foreign matter remaining even after backwashing in a filter equipped with a nonwoven fabric as a filter medium. However, in this method, it was found that the backwashing performance may deteriorate if the filter is used for a long time. It is presumed that the reason for the decrease in backwashing performance is that the alkoxysilane bleeds out from the fibers as the filter is used for a longer period of time.
In contrast, the nonwoven fabric of the present disclosure contains fibers containing a predetermined amount of a thermoplastic resin and a specific silylated polyolefin, so that it can be applied as a filter medium for filters and has excellent backwashing properties and maintainability. becomes. The reason for this is that the inclusion of a specific amount of the specific silylated polyolefin can significantly reduce the surface energy of the fiber containing the thermoplastic resin, and the specific silylated polyolefin has high compatibility with the thermoplastic resin, It is presumed that the backwashability and its maintainability were dramatically improved by making it difficult to separate from the fibers. The above effects of the nonwoven fabric of the present disclosure are exhibited more remarkably when a polyolefin having the same type of structure as the specific silylated polyolefin is used as the thermoplastic resin.
However, the above speculation is not intended to restrictively interpret the nonwoven fabric of the present disclosure, but is explained as an example.

The present inventors have found that adding alkoxysilane to the fibers constituting the nonwoven fabric to lower the surface free energy makes it difficult for water to pass through the nonwoven fabric, thereby improving the water pressure resistance. However, it has been found that, in this method, the water resistance of an article made of nonwoven fabric, such as a liquid shielding article, may deteriorate if the article is used for a long period of time. The reason for the decrease in water resistance is presumed to be that the alkoxysilane bleeds out from the fibers as the article is used for a longer period of time.
On the other hand, the nonwoven fabric of the present disclosure includes fibers containing a predetermined amount of a thermoplastic resin and a specific silylated polyolefin, thereby improving water pressure resistance and maintaining the same. The reason for this is that the inclusion of a specific amount of the specific silylated polyolefin can significantly reduce the surface energy of the fiber containing the thermoplastic resin, and the specific silylated polyolefin has high compatibility with the thermoplastic resin, It is presumed that the resistance to water pressure and its maintainability were improved by making it difficult to separate from the fibers.
However, the above speculation is not intended to restrictively interpret the nonwoven fabric of the present disclosure, but is explained as an example.

The nonwoven fabric of the present disclosure can be applied as a filter medium of a filter, and has at least one of the properties of being excellent in backwashability and its maintainability, and the properties of being excellent in water pressure resistance and its maintainability. You don't have to. For example, when the nonwoven fabric of the present disclosure is applied as a filter medium for a filter, the nonwoven fabric of the present disclosure only needs to have excellent backwashability and maintainability, and has excellent water pressure resistance and maintainability. It doesn't have to be.

<Fiber>
The fibers contained in the nonwoven fabric of the present disclosure contain a thermoplastic resin of 80% by mass or more relative to the total mass of the fibers, and a specific silylated polyolefin of 0.01% to 20% by mass relative to the total mass of the fibers. % and The nonwoven fabric of the present disclosure preferably contains 50% by mass or more of the fiber, more preferably 90% by mass or more, more preferably 95% by mass or more, from the viewpoint of further improving backwashability and maintainability thereof. Preferably, it is particularly preferably contained in an amount of 99% by mass or more. The nonwoven fabric of the present disclosure may contain 100% by mass or less of the fibers, and may contain 100% by mass of the fibers, for example.

(Thermoplastic resin)
The thermoplastic resin is not particularly limited, and various known thermoplastic resins can be used. Thermoplastic resins according to the present disclosure do not include specific silylated polyolefins.

The thermoplastic resin contained in the fiber may be of only one type, or may be of two or more types.

Specific examples of thermoplastic resins include polyolefin (PO), polyamide (PA), polyimide (PI), polyester (PEs) [e.g., polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), etc.], ethylene-vinyl acetate copolymer (EVA), polyetherimide (PEI), polyetherketone (PEEK), polyvinyl chloride ( PVC), polyacetal (POM), polycarbonate (PC), polysulfone (PSF), polyethersulfone (PES), polyphenylene sulfide (PPS) and the like.

The melt mass flow rate (MFR) of the thermoplastic resin is not particularly limited as long as the nonwoven fabric can be produced. The melt mass flow rate (MFR) of the thermoplastic resin is preferably 10 g/10 minutes to 10000 g/10 minutes when the nonwoven fabric of the present disclosure is a meltblown nonwoven fabric, from the viewpoint of the fineness of the average fiber diameter, spinnability, etc. , more preferably 30 g/10 min to 5000 g/10 min, and still more preferably 50 g/10 min to 1800 g/10 min.
The melt mass flow rate (MFR) of the thermoplastic resin is preferably 10 g/10 min to 200 g/10 min when the nonwoven fabric of the present disclosure is a spunbond nonwoven fabric, from the viewpoint of the fineness of the average fiber diameter, spinnability, etc. Yes, more preferably 20 g/10 minutes to 100 g/10 minutes.

The measurement of melt mass flow rate (MFR) in the present disclosure conforms to ASTM D-1238-04 and is carried out under conditions of 230°C and a load of 2160g.

Specifically, MFR is measured at temperature and load as specified individually for each material in ASTM D-1238-04. If multiple types of load are specified, the minimum load shall be used for measurement. In addition, when measuring substances that are not individually specified in ASTM D-1238-04, the method of measuring the minimum load at the temperature of Tm + 60 ° C of the substance measured in Table 1 described in ASTM D-1238-04 to select.
As the MFR measuring device, for example, the measuring device used in the examples described later can be used.

The thermoplastic resin preferably contains at least one selected from the group consisting of polyolefins, polyamides and polyesters from the viewpoint of ease of application to filters, and further improves compatibility with the specific silylated polyolefin. From the viewpoint of further improving the maintenance of backwashability, it is more preferable to contain a polyolefin.
The total content of polyolefin, polyamide and polyester, preferably the content of polyolefin, may be 50% by mass to 100% by mass, or 80% by mass to 100% by mass, based on the total thermoplastic resin. good.

The polyolefin is not particularly limited, and homopolymers of olefin monomers such as ethylene, propylene, butene, pentene, hexene, octene, decene, and 4-methyl-1-pentene, or two or more kinds of olefin monomers. A copolymer is mentioned. Polyolefins may also contain structural units formed from monomers other than the above olefin monomers (eg, cyclic polyolefins, polar polyolefins, etc.).

Among these, the polyolefin preferably contains at least one selected from polyethylene and polypropylene, and more preferably contains polypropylene, from the viewpoint of further improving the maintenance of backwashability.
Polyethylene is preferably a polymer containing 50% by mass or more of ethylene units.
As the polypropylene, a polymer containing 50% by mass or more of propylene units is preferable, and a polymer containing 100% by mass of propylene units (that is, a homopolymer of propylene) is more preferable.
The total content of polyethylene and polypropylene, or the content of polypropylene may be 50% by mass to 100% by mass, or may be 80% by mass to 100% by mass, based on the total thermoplastic resin.

The melt mass flow rate (MFR) of polypropylene is not particularly limited as long as a nonwoven fabric can be produced. MFR of polypropylene is preferably 10 g/10 min to 10000 g/10 min, more preferably 50 g/10 min when the nonwoven fabric of the present disclosure is a meltblown nonwoven fabric, from the viewpoint of fineness of average fiber diameter, spinnability, etc. min to 2000 g/10 min.
The melt mass flow rate (MFR) of polypropylene is preferably 10 g/10 min to 200 g/10 min when the nonwoven fabric of the present disclosure is a spunbond nonwoven fabric, from the viewpoint of fineness of average fiber diameter, spinnability, etc. More preferably, it is 20 g/10 minutes to 100 g/10 minutes.
The MFR of polypropylene is a value measured at 230° C. under a load of 2160 g according to ASTM D-1238-04.

The weight average molecular weight (Mw) of polypropylene is preferably 20,000 or more, more preferably 30,000 or more, and even more preferably 40,000 or more.
The weight average molecular weight (Mw) of polypropylene is preferably 500,000 or less, more preferably 300,000 or less, and even more preferably 100,000 or less.
When the weight average molecular weight (Mw) of polypropylene is within the above range, the average fiber diameter tends to be small, which is preferable.
From the above viewpoint, the weight average molecular weight (Mw) of polypropylene is preferably 20,000 to 500,000, more preferably 30,000 to 300,000, and even more preferably 40,000 to 100,000.

The above weight average molecular weight (Mw) is a value obtained by measuring by a gel permeation chromatography method (GPC method), obtaining the measurement result as a polystyrene conversion value, and then converting it to polypropylene by a universal calibration method.

When two or more types of polypropylene having different MFRs and/or molecular weights are included, the polypropylene is at least one type selected from polypropylene having an MFR of 10 g/min to 10000 g/10 min, polypropylene wax, and polypropylene having long chain branches. are preferred. With such a mixture, the average fiber diameter tends to be small, and the collection efficiency of small particles tends to be improved.

The content of the thermoplastic resin is 80% by mass or more with respect to the total mass of fibers contained in the nonwoven fabric. When the content of the thermoplastic resin is 80% by mass or more, spinning stability when producing a nonwoven fabric can be obtained. In addition, since the fibers included in the nonwoven fabric of the present disclosure contain 0.01% by mass to 20% by mass of the specific silylated polyolefin with respect to the total mass of the fibers, the upper limit of the content of the thermoplastic resin is 99.99. % by mass.
The thermoplastic resin content is more preferably 85% by mass to 99.99% by mass, more preferably 88% by mass to 99.5% by mass, in order to improve the backwashability and maintainability of the filter comprising the nonwoven fabric of the present disclosure. % is more preferred, and 92% by mass to 99.9% by mass is particularly preferred.

(specific silylated polyolefin)
The specific silylated polyolefin is a reaction between a silicon-containing compound containing a structural unit represented by the following formula (1) and a vinyl group-containing compound having a number average molecular weight of 100 or more and 500,000 or less as determined by the GPC method. (However, the reaction product of the silicon-containing compound having two or more SiH groups per molecule and the vinyl group-containing compound having an average of 2.0 or more vinyl groups per molecule is excluded), Silylated polyolefins and their derivatives.
—Si(R ¹ )HY ¹ — (1)
(In formula (1), R ¹ represents a hydrogen atom, a halogen atom or a hydrocarbon group, Y ¹ represents O, S or NR ³⁰ , and R ³⁰ represents a hydrogen atom or a hydrocarbon group.)
The fibers included in the nonwoven fabric of the present disclosure contain at least one selected from specific silylated polyolefins in an amount of 0.01% by mass to 20% by mass relative to the total mass of the fibers.
GPC method means gel permeation chromatography method.
Here, in the present disclosure, the term "derivative" means a compound in which a part of the structure is modified while retaining the basic skeleton of the compound.

In the specific silylated polyolefin, for example, -Si-H in the silicon-containing compound containing the structural unit of formula (1) reacts with -CH=CH ₂ (that is, vinyl group) in the vinyl group-containing compound. may contain a -Si-C-C- structure generated by
However, when using a compound having two or more SiH groups per molecule as the silicon-containing compound and using a compound having an average of 2.0 or more vinyl groups per molecule as the vinyl group-containing compound, The present disclosure excludes such cases, since it is believed that the silylated polyolefins that are used, for example, will likely have a network structure.

A silicon-containing compound is a hydrosilane compound having a structural unit represented by the following formula (1).
—Si(R ¹ )HY ¹ — (1)
In formula (1), R ¹ represents a hydrogen atom, a halogen atom or a hydrocarbon group, Y ¹ represents O, S or NR ³⁰ , and R ³⁰ represents a hydrogen atom or a hydrocarbon group.
Halogen atoms include fluorine, chlorine, bromine, and iodine atoms.
Hydrocarbon groups include alkyl groups, alkenyl groups, and aryl groups.

Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, hexyl, 2-ethylhexyl, octyl, decyl, and octadecyl groups. linear or branched alkyl groups; cycloalkyl groups such as cyclopentyl group, cyclohexyl group and norbornyl group; arylalkyl groups such as benzyl group, phenylethyl group and phenylpropyl group;
Examples of alkenyl groups include vinyl groups, propenyl groups, cyclohexenyl groups, and the like.

Aryl groups include phenyl, tolyl, dimethylphenyl, trimethylphenyl, ethylphenyl, propylphenyl, biphenyl, naphthyl, methylnaphthyl, anthryl, and phenanthryl groups.

In addition, the above hydrocarbon group may contain one or more heteroatoms. Specific examples include groups in which at least one hydrogen of these groups is replaced with a group containing a halogen atom, an oxygen atom, a nitrogen atom, a silicon atom, a phosphorus atom, or a sulfur atom.

In one embodiment, the silicon-containing compound has a structure represented by formula (2) below. R ²² —(Si(R ²¹ )HY ²¹ ) _m —Z—(Y ²² —Si(R ²³ )H) _n —R ²⁴ (2)
In formula (2), R ²¹ and R ²³ each independently represent a hydrogen atom, a halogen atom or a hydrocarbon group,
R ²² and R ²⁴ each independently represent a halogen atom or a hydrocarbon group,
Y ²¹ and Y ²² each independently represent O, S or NR ³⁰ , R ³⁰ represents a hydrogen atom or a hydrocarbon group,
m is 0 or 1,
n is 0 or 1,
When multiple R ²¹ , R ²³ , Y ²¹ and Y ²² are present, each group may be the same or different,
Z represents a divalent group represented by the following formula (3).
—Si(R ⁴¹ )(R ⁴¹ )—(Y ²³ —Si(R ⁴¹ )(R ⁴¹ )) _l — (3)

In formula (3), R ⁴¹ represents a hydrogen atom, a halogen atom or a hydrocarbon group, each R ⁴¹ may be the same or different, and each Y ²³ independently represents O, S or represents NR ³⁰ , R ³⁰ represents a hydrogen atom or a hydrocarbon group,
l is an integer from 0 to 10,000.
However, when m=n=0 in formula (2) above, at least one R ⁴¹ in formula (3) is a hydrogen atom.

The definitions of halogen atoms and hydrocarbon groups in formulas (2) and (3) are the same as those in formula (1) above.

It is also a typical embodiment that the hydrocarbon groups in formulas (1), (2), and (3) consist only of carbon atoms and hydrogen atoms.

In one embodiment, the silicon-containing compound preferably has 3 or more, more preferably 5 or more, and even more preferably 10 or more silicon atoms. Also, the silicon-containing compound preferably has 10,000 or less, more preferably 1,000 or less, even more preferably 300 or less, and particularly preferably 50 or less silicon atoms.

In one embodiment, l in formula (3) above is an integer from 0 to 10,000. Preferred upper and lower limits of l include numbers determined from the values of m and n in formula (2) and the above preferred number of silicon atoms.

In one embodiment, m=n=1 in the above formula (2), that is, a silicon-containing compound having SiH groups at both ends is preferably used.

In one embodiment, m = 1 and n = 0 in the above formula (2), that is, a silicon-containing compound having a SiH group at one end is preferably used.

Particularly preferred silicon-containing compounds include compounds in which m=n=1 and R ²¹ , R ²³ and R ⁴¹ are all hydrocarbon groups in formulas (2) and (3) above.
Other particularly preferred silicon-containing compounds include compounds in which m=1, n=0, and R ²¹ and R ⁴¹ are all hydrocarbon groups in formulas (2) and (3) above.

Specific examples of silicon-containing compounds are shown below.

Silicon-containing compounds include compounds having one SiH group.
Examples of silicon-containing compounds having one SiH group include compounds represented by the following formula (2a), in which some or all of the methyl groups in the following formula (2a) are ethyl groups, propyl groups, Compounds substituted with a butyl group, a phenyl group, a trifluoropropyl group, and the like are included.
HSi(CH ₃ ) ₂ O—(—Si(CH ₃ ) ₂ —O—) _d —Si(CH ₃ ) ₃ (2a)
(In formula (2a), d is an integer of 1 or more, and the upper limit is, for example, 1000, preferably 300, and more preferably 50.)
More specific examples of such compounds include, but are not limited to, the compounds shown below.
_C4H9 -(( _CH3 ) _2SiO ) _9- ₍ _CH3 ) _2SiH
_C4H9 -(( _CH3 ) _2SiO ) _65- ₍ _CH3 ) _2SiH

Another example of the silicon-containing compound having one SiH group includes, for example, a dimethylsiloxane-methylhydrogensiloxane copolymer represented by the following formula (2b), one of the methyl groups in the following formula (2b) Examples include compounds partially or wholly substituted with an ethyl group, a propyl group, a phenyl group, a trifluoropropyl group, or the like.
Si(CH ₃ ) ₃ O-(-Si(CH ₃ ) ₂ -O-) _e -(-SiH(CH ₃ )-O-)-Si(CH ₃ ) ₃ (2b)
(In formula (2b), e is an integer of 0 or more, and the upper limit is, for example, 1000, preferably 300, and more preferably 50.)
The order in which the —Si(CH ₃ ) ₂ —O— units and the —SiH(CH ₃ )—O— units are arranged is not particularly limited, and the order may be statistically random, whether blockwise or disorderly. may be

More specific examples of such compounds include, but are not limited to, the compounds shown below.
Si(CH ₃ ) ₃ O—SiH(CH ₃ )—O—Si(CH ₃ ) ₃

Silicon-containing compounds also include compounds having two or more SiH groups.

Examples of silicon-containing compounds having two or more SiH groups include, for example, methylhydrogenpolysiloxane represented by the following formula (2c); , propyl group, phenyl group, trifluoropropyl group and the like.
(CH ₃ ) ₃ SiO—(—SiH(CH ₃ )—O—) _f —Si(CH ₃ ) ₃ (2c)
(In formula (2c), f is an integer of 2 or more, and the upper limit is, for example, 1000, preferably 300, and more preferably 50.)

Other examples of silicon-containing compounds having two or more SiH groups include, for example, a dimethylsiloxane-methylhydrogensiloxane copolymer represented by the following formula (2d), and a methyl group in the following formula (2d): Examples include compounds partially or wholly substituted with an ethyl group, a propyl group, a phenyl group, a trifluoropropyl group, or the like.
(CH ₃ ) ₃ SiO—(—Si(CH ₃ ) ₂ —O—) _g —(—SiH(CH ₃ )—O—) _h —Si(CH ₃ ) ₃ (2d)
(In formula (2d), g is an integer of 1 or more, h is an integer of 2 or more, and the upper limit of the sum of g and h is, for example, 1000, preferably 300, more preferably 50.)

Further, in the formula (2d), the order in which the —Si(CH ₃ ) ₂ —O— units and —SiH(CH ₃ )—O— units are arranged is not particularly limited, and may be block-like or disorderly. may be statistically random.
More specific examples of such compounds include, but are not limited to, the compounds shown below.

Further examples of silicon-containing compounds having two or more SiH groups include, for example, methylhydrogenpolysiloxane represented by the following formula (2e), in which some or all of the methyl groups are ethyl and compounds substituted with groups such as groups, propyl groups, phenyl groups, and trifluoropropyl groups.
HSi(CH ₃ ) ₂ O—(—Si(CH ₃ ) ₂ —O—) _i —Si(CH ₃ ) ₂ H (2e)
(In formula (2e), i is an integer of 1 or more, and the upper limit is, for example, 1000, preferably 300, and more preferably 50.)

More specifically, such compounds include, but are not limited to, compounds whose structure corresponding to the number average molecular weight corresponds to the structure shown below.
HSi( _CH3 ) _2O -(-Si( _CH3 ) ₂ -O-) ₅ _- Si( _CH3 )2H
HSi( _CH3 ) _2O -(-Si( _CH3 ) ₂ -O-) ₈ _- Si( _CH3 )2H
HSi( _CH3 ) _2O -(-Si( _CH3 ) ₂ -O-) ₁₈ _- Si( _CH3 )2H
HSi( _CH3 ) _2O -(-Si( _CH3 ) ₂ -O-) ₈₀ _- Si( _CH3 )2H
HSi( _CH3 ) _2O -(-Si( _CH3 ) ₂ -O-) ₂₃₀ _- Si( _CH3 )2H

Further examples of silicon-containing compounds having two or more SiH groups include, for example, methylhydrogenpolysiloxane represented by the following formula (2f), in which some or all of the methyl groups are ethyl and compounds substituted with groups such as groups, propyl groups, phenyl groups, and trifluoropropyl groups.
HSi( _CH3 ) _2O -(-SiH( _CH3 )-O-) _j _- Si( _CH3 )2H (2f)
(In formula (2f), j is an integer of 1 or more, and the upper limit is, for example, 1000, preferably 300, and more preferably 50.)

Further examples of the silicon-containing compound having two or more SiH groups include, for example, a dimethylsiloxane/methylhydrogensiloxane copolymer represented by the following formula (2g); Examples include compounds partially or wholly substituted with an ethyl group, a propyl group, a phenyl group, a trifluoropropyl group, or the like.

HSi(CH ₃ ) ₂ O-(-Si(CH ₃ ) ₂ -O-) _k -(-SiH(CH ₃ )-O-) ₁ -Si(CH ₃ ) ₂ H (2 g)
(In formula (2g), k and l are each an integer of 1 or more, and the upper limit of the sum of k and l is, for example, 1000, preferably 300, more preferably 50.)
In addition, the order in which the —Si(CH ₃ ) ₂ —O— units and —SiH(CH ₃ )—O— units are arranged is not particularly limited, and the order may be statistically random whether it is blockwise or disorderly. may be

In the present disclosure, the number average molecular weight of the vinyl group-containing compound determined by the GPC method is 100 or more and 500,000 or less, more preferably 500 or more and 300,000 or less. It is more preferably 1,500 or more and 100,000 or less. When the number average molecular weight is at least the above lower limit, bleeding of the obtained silylated polyolefin from the resin tends to be suppressed. When the number average molecular weight is equal to or less than the above upper limit, the dispersibility of the silylated polyolefin in the resin tends to be good. In the present disclosure, the number average molecular weight (Mn), weight average molecular weight (Mw) and Mw/Mn are values converted to polyethylene, as described later.

The vinyl group-containing compound is described below.
The vinyl group-containing compound is generally obtained by polymerizing or copolymerizing one or more selected from olefins having 2 to 50 carbon atoms.

Specific examples of olefins having 2 to 50 carbon atoms include ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl -1-pentene, 3,4-dimethyl-1-pentene, 4-methyl-1-hexene, 3-ethyl-1-pentene, 3-ethyl-4-methyl-1-pentene, 3,4-dimethyl-1 -hexene, 4-methyl-1-heptene, 3,4-dimethyl-1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, vinyl α-olefins such as cyclohexane; olefins containing internal double bonds such as cis-2-butene, trans-2-butene; isobutene, 2-methyl-1-pentene, 2,4-dimethyl-1-pentene, 2 ,4-dimethyl-1-hexene, 2,4,4-trimethyl-1-pentene, 2,4-dimethyl-1-heptene, 2-methyl-1-butene, 2-methyl-1-hexene, 2-methyl -1-heptene, 2-methyl-1-octene, 2,3-dimethyl-1-butene, 2,3-dimethyl-1-pentene, 2,3-dimethyl-1-hexene, 2,3-dimethyl-1 -octene, 2,3,3-trimethyl-1-butene, 2,3,3-trimethyl-1-pentene, 2,3,3-trimethyl-1-hexene, 2,3,3-trimethyl-1-octene , 2,3,4-trimethyl-1-pentene, 2,3,4-trimethyl-1-hexene, 2,3,4-trimethyl-1-octene, 2,4,4-trimethyl-1-hexene, 2 , 4,4-trimethyl-1-octene, 2-methyl-3-cyclohexyl-1-propylene, vinylidenecyclopentane, vinylidenecyclohexane, vinylidenecyclooctane, 2-methylvinylidenecyclopentane, 3-methylvinylidenecyclopentane, 4- vinylidene compounds such as methylvinylidenecyclopentane; aryls such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, o-ethylstyrene, m-ethylstyrene and p-ethylstyrene Vinyl compounds; arylvinylidene compounds such as α-methylstyrene, α-ethylstyrene, 2-methyl-3-phenylpropylene; methyl methacrylate, ethyl methacrylate, -n-propyl methacrylate, isopropyl methacrylate Functional group substitution such as phenyl, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, 2-cyanopropylene, 2-aminopropylene, 2-hydroxymethylpropylene, 2-fluoropropylene, 2-chloropropylene, etc. Vinylidene compounds; cyclobutene, cyclopentene, 1-methyl-1-cyclopentene, 3-methyl-1-cyclopentene, 2-methyl-1-cyclopentene, cyclohexene, 1-methyl-1-cyclohexene, 3-methyl-1-cyclohexene, 2 -methyl-1-cyclohexene, cycloheptene, cyclooctene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, 5,6-dihydrodicyclopentadiene, 3a,4,5,6,7,7a-hexahydro- Aliphatic cyclic olefins containing internal double bonds such as 1H indene, tricyclo[6.2.1.0 ^2,7 ]undec-4-ene, cyclopentadiene, dicyclopentadiene; 3-enylbenzene, cyclohex-2-enylbenzene, cyclohex-3-enylbenzene, indene, 1,2-dihydronaphthalene, 1,4-dihydronaphthalene, 1,4-methino-1,4,4a,9a tetrahydrofluorene, etc. butadiene, isoprene, 4-methyl-1,3-pentadiene, 4-methyl-1,4-pentadiene, 1,3-pentadiene, 1,4-pentadiene, 1,5-hexadiene , 1,4-hexadiene, 1,3-hexadiene, 1,3-octadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, ethylidenenorbornene, vinylnorbornene, di Two or more double bonds such as cyclopentadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 5,9-dimethyl-1,4,8-decatriene and chain polyenes having two or more double bonds.

Also, the olefin having 2 to 50 carbon atoms may have a functional group containing an atom such as an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Unsaturated carboxylic acids such as acrylic acid, fumaric acid, itaconic acid, bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid and their sodium, potassium, lithium and zinc salts , magnesium salts, calcium salts; unsaturated carboxylic acid metal salts such as maleic anhydride, itaconic anhydride, bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride; acid anhydride; methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, etc. Unsaturated carboxylic acid ester; vinyl esters such as vinyl acetate, vinyl propionate, vinyl caproate, vinyl caprate, vinyl laurate, vinyl stearate, and vinyl trifluoroacetate; glycidyl acrylate, glycidyl methacrylate, mono-itaconate unsaturated glycidyl esters such as glycidyl esters;
halogenated olefins such as vinyl chloride, vinyl fluoride and allyl fluoride; unsaturated cyano compounds such as acrylonitrile and 2-cyano-bicyclo[2.2.1]hept-5-ene; unsaturated compounds such as methyl vinyl ether and ethyl vinyl ether; saturated ether compounds; unsaturated amides such as acrylamide, methacrylamide, and N,N-dimethylacrylamide;
Functional group-containing styrene derivatives such as methoxystyrene, ethoxystyrene, vinyl benzoic acid, methyl vinyl benzoate, vinylbenzyl acetate, hydroxystyrene, o-chlorostyrene, p-chlorostyrene, and divinylbenzene; N-vinylpyrrolidone; .

In a preferred embodiment, the vinyl group-containing compound has a structure represented by formula (4) below. The vinyl group-containing compound having the structure represented by formula (4) is preferably a compound having a number average molecular weight of 100 or more and 500,000 or less.
When the vinyl group-containing compound has the structure represented by formula (4), the compatibility between the specific silylated polyolefin and the thermoplastic resin is further improved, and as a result, the reverse of the filter to which the nonwoven fabric of the present disclosure is applied. It is preferable because it improves washability and maintainability.

A-CH=CH ₂ (4)
Here, in formula (4), A represents a polymer chain containing structural units derived from one or more α-olefins having 2 to 50 carbon atoms.

In formula (4), part A of the vinyl group-containing compound is preferably a copolymer of two or more olefins selected from the group consisting of ethylene polymer chains, propylene polymer chains, and α-olefins having 2 to 50 carbon atoms. is a chain. Further, the α-olefin is preferably an α-olefin having 2 to 20 carbon atoms.

In a preferred embodiment, A of the vinyl group-containing compound having the structure represented by formula (4) is a polymer chain composed only of α-olefins having 2 to 50 carbon atoms. More preferably, A of the vinyl group-containing compound is a polymer chain composed only of α-olefins having 2 to 20 carbon atoms. More preferably, A of the vinyl group-containing compound is an ethylene homopolymer chain, a propylene homopolymer chain, or an ethylene/C3-C20 α-olefin copolymer chain, and an ethylene homopolymer chain is particularly preferred. preferable.
That A of the vinyl group-containing compound is an ethylene homopolymer chain means that the polyolefin portion in the specific silylated polyolefin obtained using the vinyl group-containing compound is polyethylene.

A particularly preferred embodiment of the present disclosure is a form in which the polyolefin portion in the specific silylated polyolefin is polyethylene, and the thermoplastic resin is polypropylene. In this case, the specific silylated polyolefin tends to localize on the surface of the fibers contained in the nonwoven fabric and stay on the surface of the fibers, so that the filter to which the nonwoven fabric of the present disclosure is applied has improved backwashability and maintainability.

The vinyl group-containing compound represented by formula (4) has an ethylene-derived structural unit in the range of 81 mol% to 100 mol%, and an α-olefin-derived structural unit having 3 to 20 carbon atoms in the range of 0 mol% to 19 mol%. An ethylene/α-olefin copolymer is desirable. More preferably, it is an ethylene/α-olefin copolymer having 90 mol% to 100 mol% of ethylene-derived structural units and 0 mol% to 10 mol% of α-olefin-derived structural units having 3 to 20 carbon atoms. is desirable. In particular, it is preferable that the ethylene-derived structural unit is 100 mol %.

The vinyl group-containing compound represented by formula (4) has a molecular weight distribution (ratio of weight average molecular weight to number average molecular weight, Mw/Mn) measured by gel permeation chromatography (GPC method) of 1.1 to 3. It is preferably in the range of .0.

Further, the vinyl group-containing compound represented by formula (4) preferably has a number average molecular weight (Mn) in the range of 100 to 500,000, more preferably 500 to 300,000. 100,000 or less is more preferable.

Further, the vinyl group-containing compound represented by formula (4) preferably has a melting point of 70°C or higher and 130°C or lower.

More preferably, the vinyl group of the vinyl group-containing compound represented by formula (4) is present at the end of the main chain, and more preferably the vinyl group is present only at the end of the main chain.

The existence of a vinyl group at the end of the main chain can be confirmed by using ¹³ C-NMR and ¹ H-NMR, for example. For example, when A in formula (4) is an ethylene homopolymer, ¹³ C-NMR can detect no tertiary carbon and ¹ H-NMR can detect vinyl group hydrogen. mentioned. Even with ¹ H-NMR alone, it is possible to confirm the structure by assigning each detected proton peak.
For example, in the compound synthesized in Synthesis Example 1 of WO 2012/098865, the chemical shift peak of 0.81 ppm with a proton integral value of 3 is a methyl group at one end, and the chemical shift is 1.10-1. The peak at 45 ppm is the main chain methylene group, the chemical shift peak at 1.93 ppm with a proton integral value of 2 is the methylene group adjacent to the terminal vinyl group, 4.80, 4.86 with a proton integral value of 1, respectively. Since the peak at 5.60-5.72 ppm is attributed to the terminal vinyl group, and there is no other peak of unknown attribution, it is confirmed that A is an ethylene homopolymer and has a structure containing a vinyl group only at the terminal. can be confirmed.
As another method, hydrogen of a vinyl group present at the end of the main chain has a shorter relaxation time in ¹ H-NMR measurement than hydrogen of a vinyl group present in a side chain. It can also be determined by a method of comparing the hydrogen of the vinyl group of a polymer having a vinyl group in the chain and the relaxation time.

In some cases, it can be determined by utilizing the fact that the chemical shift in ¹ H-NMR of the vinyl group in the side chain is lower than that of the terminal vinyl group.

Further, when the vinyl group-containing compound represented by formula (4) contains a vinyl group only at the end of the main chain, the terminal unsaturation rate (VE described later) calculated by ¹ H-NMR is 60 mol%. It is desirable that the content is at least 100 mol % or less. A further preferred embodiment is one in which the terminal unsaturation ratio calculated by ¹ H-NMR is 80 mol % or more and 99.5 mol % or less, more preferably 90 mol % or more and 99 mol % or less.

The vinyl group-containing compound represented by formula (4) can be obtained by a known method such as the method described in JP-A-2003-73412.

When A in formula (4) is a polyolefin polymer chain having an ethylene homopolymer chain, it can also be produced by the following method.
(a) Using a transition metal compound having a salicylaldoimine ligand as disclosed in JP-A-2000-239312, JP-A-2001-2731, JP-A-2003-73412, etc. as a polymerization catalyst polymerization method.
(b) A polymerization method using a titanium-based catalyst comprising a titanium compound and an organoaluminum compound.
(c) A polymerization method using a vanadium-based catalyst comprising a vanadium compound and an organoaluminum compound.
(d) A polymerization method using a Ziegler-type catalyst comprising a metallocene compound such as zirconocene and an organoaluminumoxy compound (aluminoxane).

~Method for producing silylated polyolefin~
The specific silylated polyolefin according to the present disclosure can be produced by any method. Preferably, a vinyl group-containing compound and a silicon-containing compound are reacted in the presence of a transition metal catalyst (provided that the silicon-containing compound has two or more SiH groups per molecule, and the vinyl group silylated polyolefins or derivatives thereof, or mixtures thereof, except when a compound having an average of 2.0 or more vinyl groups per molecule is used as the containing compound.

The step of reacting the vinyl group-containing compound and the silicon-containing compound is described in detail below.

In this step, a vinyl group-containing compound and a silicon-containing compound are reacted in the presence of a transition metal catalyst (provided that the silicon-containing compound has two or more SiH groups per molecule, and the vinyl Except for the case of using a group-containing compound having an average of 2.0 or more vinyl groups per molecule), a silylated polyolefin is obtained.

As the transition metal catalyst, for example, a simple substance of platinum (platinum black), a transition metal halide, chloroplatinic acid, a platinum-olefin complex, a platinum-alcohol complex, or a platinum carrier supported on a carrier such as alumina or silica. things, etc.

The transition metal halide is a transition metal halide of Groups 3 to 12 of the periodic table of the elements, and from the viewpoint of ease of availability and economy, transitions of Groups 8 to 10 of the periodic table are preferred. Halides of metals, more preferably halides of platinum, rhodium, iridium, ruthenium, osmium, nickel and palladium. Halides of platinum are more preferred. A mixture of two or more transition metal halides may also be used.

　The halogen of the transition metal halide includes fluorine, chlorine, bromine, iodine, etc. Among them, chlorine is preferable in terms of ease of handling.

Alternatively, a transition metal catalyst composition obtained by previously mixing and stirring a transition metal halide and a silicon-containing compound according to the method described in JP-A-2010-37555 may be used as a catalyst. When such a transition metal catalyst composition is used as a catalyst, the reaction between the vinyl group-containing compound and the silicon compound proceeds efficiently. For this reason, the reaction rate of the double bond of the vinyl group-containing compound is usually 80% or more, preferably 90% or more, more preferably 95% or more, and the amount of the by-product vinylene derivative is less than that of the silylated polyolefin. On the other hand, it is usually 20% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less.

The amount ratio for reacting the vinyl group-containing compound and the silicon-containing compound varies depending on the purpose, but the equivalent ratio between the vinyl group in the vinyl group-containing compound and the Si—H bond in the silicon-containing compound is 0.01 equivalent. It is in the range of 1-fold to 10-fold equivalent, preferably 0.1-fold to 2-fold equivalent.

The reaction between the vinyl group-containing compound and the silicon-containing compound is carried out in the presence of the transition metal catalyst. The quantitative ratio between the transition metal catalyst and the vinyl group-containing compound is in the range of 10 ⁻¹⁰ to 10 ⁻¹ times the equivalent ratio of the vinyl group in the vinyl group-containing compound to the transition metal content in the transition metal catalyst. and preferably in the range of 10 ⁻⁷ to 10 ⁻³ equivalents.

As for the reaction method in the reaction between the vinyl group-containing compound and the silicon-containing compound, the reaction may be carried out at the end, and the method is not limited, and may be carried out, for example, as follows. A vinyl group-containing compound is charged into a reaction vessel, and a silicon-containing compound and a transition metal catalyst are charged under a nitrogen atmosphere. The above reactor is set in an oil bath whose internal temperature has been raised to the melting point of the vinyl group-containing compound or higher in advance, and the mixture is stirred. After the reaction, the oil bath is removed and the mixture is cooled to room temperature. The resulting reaction mixture is taken out in a poor solvent such as methanol or acetone and stirred for 2 hours. After that, the obtained solid is collected by filtration, washed with the above poor solvent, and dried to obtain the desired product.

The reaction between the vinyl group-containing compound and the silicon-containing compound is preferably carried out at a reaction temperature in the range of 100°C to 200°C, more preferably at a temperature higher than the melting point of the vinyl group-containing compound to be reacted. When the reaction temperature is 100° C. or higher, the reaction efficiency tends to be excellent. Moreover, although the pressure can be usually normal pressure, it can also be carried out under increased pressure or reduced pressure, if necessary.

A solvent can also be used if necessary. Solvents that are inert to the starting silicon-containing compound and vinyl group-containing compound can be used. Specific examples of usable solvents include aliphatic hydrocarbons such as n-hexane, alicyclic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as toluene and xylene, esters such as ethyl acetate, acetone, ketones such as methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, and methyl propyl ketone; ethers such as tetrahydrofuran and 1,4-dioxane; and halogenated hydrocarbons such as chloroform, dichloroethane, trichloroethane, tetrachloroethane, and perchloroethane. . Among these, aromatic hydrocarbons such as toluene and xylene are particularly preferred.

When a solvent is used, the amount of the solvent used affects the solubility of the raw material, and is preferably 100 times or less by mass, more preferably 20 times or less by mass, relative to the raw material. The present disclosure is most preferably run solvent-free.

As described above, by reacting a vinyl group-containing compound and a silicon-containing compound in the presence of a transition metal catalyst, a reaction mixture containing a silylated polyolefin containing a structural unit represented by formula (1) is obtained.

The silylated polyolefin may be taken out by drying the reaction mixture as it is, but it can be taken out by reprecipitation in a poor solvent or sludge. The poor solvent can be appropriately selected as long as the solubility of the silylated polyolefin is low, and preferably one that removes the above-mentioned impurities. Specific examples of the poor solvent include acetone, methanol, ethanol, n-propanol, isopropanol, acetonitrile, ethyl acetate, n-hexane, n-heptane, etc. Among them, acetone, methanol, and n-heptane. preferable.

Specific examples of the vinyl group-containing compound according to the present disclosure include the compound represented by formula (4) as described above.
A-CH=CH ₂ (4)
(In formula (4), A represents a polymer chain containing structural units derived from one or more α-olefins having 2 to 50 carbon atoms.)

When the vinyl group-containing compound is a compound represented by formula (4), a structure (structure 4-1) in which A consists only of an α-olefin having 2 to 20 carbon atoms is preferable.

More preferably, the vinyl group-containing compound has a structure (Structure 4-2) in which —CH═CH ₂ is present at the end of the polymer main chain.

Even more preferably, the vinyl group-containing compound has a structure (structure 4-3) in which -CH=CH ₂ is present only at the ends of the polymer backbone.

Even more preferably, the vinyl group-containing compound has a structure in which A consists solely of an α-olefin having 2 to 20 carbon atoms and —CH═CH ₂ is present at the end of the polymer main chain (structure 4-4) (structure 4 -1 and structure 4-2).

Even more preferably, the vinyl group-containing compound has a structure in which A consists solely of an α-olefin having 2 to 20 carbon atoms, and -CH=CH ₂ is present only at the ends of the polymer main chain (structure 4-5) ( combination of structure 4-1 and structure 4-3).

As described above, the silicon-containing compound according to the present disclosure preferably has the structure of formula (2). Among them, when the vinyl group-containing compound is represented by formula (4), the silicon-containing compound is preferably a structure (structure 2-1) in which m = n = 1 in formula (2), and further formula (2 ) in which all R ⁴¹ in Z are selected from a hydrocarbon group and a halogen (structure 2-2) (that is, it is desirable that none of R ⁴¹ is a hydrogen atom).

Further, when the vinyl group-containing compound has an average of less than 2 vinyl groups per molecule, the silicon-containing compound has m = 1 and n = 0 in formula (2), and wherein all R ⁴¹ are selected from hydrocarbon groups and halogen (structure 2-3), m = 0 and n = 0 in formula (2), and one of R ⁴¹ in formula (2) is a hydrogen atom (Structure 2-4), in addition to compounds having one SiH group per molecule, it is also possible to use compounds having two or more Si—H bonds per molecule. Yes, for example structure 2-1 or structure 2-2 described above.

The reactant may have, for example, a structure represented by formula (X).

In formula (X), A ¹ , A ² and A ³ each independently represent a polyolefin chain or a hydrocarbon group having 1 to 20 carbon atoms. Each R independently represents a hydrocarbon group having 1 to 20 carbon atoms. A plurality of R may be the same or different. m is an integer from 1 to 10,000. When there are multiple A ³ 's, the multiple A ³ 's may be the same or different. However, at least one of A ¹ , A ² and A ³ represents a polyolefin chain.

The polyolefin chain may be a portion derived from the aforementioned vinyl group-containing compound.
A preferred configuration of the polyolefin chain that A ¹ , A ² and A ³ in formula (X) can have is A—CH ₂ CH ₂ —. Preferred configurations of A in A-CH ₂ CH ₂ - are the same as those of A in formula (A).
In the formula (X), the preferred configuration of the hydrocarbon group having 1 to 20 carbon atoms that can be taken by A ¹ , A ² and A ³ and the preferred configuration of the hydrocarbon group having 1 to 20 carbon atoms that can be taken by R are represented by the formula ( It is the same as the structure of the hydrocarbon group that R ¹ in 1) can take.
In formula (X), m is preferably 5 or more, more preferably 10 or more. Also, m is preferably 1,000 or less, more preferably 300 or less, and more preferably 50 or less.

The specific silylated polyolefin is presumed to have, for example, structures represented by formulas (5) to (8). Of course, the combination of the silicon-containing compound and vinyl group-containing compound is not limited to these examples.

m and n in each of the above formulas represent an integer of 1 or more.

Below, we will describe a particularly preferable mode and the presumed reason for it. Hereinafter, the portion derived from the vinyl group-containing compound may be referred to as "polyolefin chain", and the portion derived from the silicon-containing compound may be referred to as "silicon-containing compound chain". When the vinyl group-containing compound has the structure represented by formula (4), especially structure 4-5, and the silicon-containing compound has structure 2-2, the silylated polyolefin is (polyolefin chain) - (silicon-containing compound It is thought to take a block copolymer-like structure in which chain)-(polyolefin chain) are linked in this order. Specifically, a compound having a presumed structure such as the above formula (5) can be exemplified.

When the vinyl group-containing compound has structure 4-5 and the silicon-containing compound has structure 2-1, and the silicon-containing compound has 3 or more SiH groups, the silylated polyolefin has ( In the block structure in which polyolefin chain) - (silicon-containing compound chain) - (polyolefin chain) are bonded in this order, it is thought that a structure in which a polyolefin chain is grafted from a silicon-containing compound chain may be included.

Further, when the vinyl group-containing compound has structure 4-5 and the silicon-containing compound has structures 2-3 and 2-4, the silylated polyolefin is specifically exemplified by the above formula (6), formula It is considered that the structure of (8) is taken.

Further, the vinyl group-containing compound has structure 4-5, and the silicon-containing compound has m = 0, n = 0, and Z is (-SiH(CH ₃ )O-) ₆ -Si(CH ₃ ) in formula (2). In the case of ₂ O--Si(C ₆ H ₅ ) ₂ --, it is considered that the form of formula (7) is taken.

(polyolefin chain)-(silicon-containing compound chain)-(polyolefin chain) vinyl group presumed to have a block copolymer structure, such as a presumed structure of formula (5) The silylated polyolefin obtained from the combination of the silicon-containing compound and the silicon-containing compound is presumed to have a polyolefin chain as a graft chain from the silicon-containing compound chain. It is thought that the silylated polyolefin is more likely to undergo molecular motion than the presumed silylated polyolefin, and therefore, for example, it is thought that the silylated polyolefin is more likely to gather on the fiber surface during spinning. Also, with the above structure, polyolefin chains are present at both ends of the silicon-containing compound chain, so it is thought that bleeding out from the fiber surface is less likely to occur.

The content of the specific silylated polyolefin is 0.01% by mass to 20% by mass, and 0.05% by mass to 15% by mass, based on the total mass of the fibers contained in the nonwoven fabric, from the viewpoint of backwashability and maintainability. % by mass is preferable, and 0.05% by mass to 12% by mass is more preferable. In addition, from the viewpoint of exhibiting backwashability and its maintainability and making the fiber diameter of the fibers contained in the nonwoven fabric in a more suitable range for filtration performance, it is more preferable to be 0.1% by mass to 8% by mass. .

The total content of the specific silylated polyolefin and the thermoplastic resin in the fibers contained in the nonwoven fabric according to the present disclosure may be, for example, 85% by mass to 100% by mass with respect to the total mass of the fibers contained in the nonwoven fabric. , 90% by mass to 100% by mass, 95% by mass to 100% by mass, or 99% by mass to 100% by mass.

(Additive)
The fibers contained in the nonwoven fabric according to the present disclosure may be formed only from the thermoplastic resin and the specific silylated polyolefin, and in addition to the thermoplastic resin and the specific silylated polyolefin, antioxidants, weather stabilizers, and light stabilizers , antiblocking agents, lubricants, pigments, softeners, hydrophilic agents, auxiliary agents, water repellents, fillers, antibacterial agents, flame retardants, alkoxysilanes, and other known additives.
When the aforementioned fibers contain known additives, the content of the additives in the fibers contained in the nonwoven fabric according to the present disclosure may be 0.01 wt% to 10 wt%, and may be 0.05 wt%. It may be up to 5% by mass, or 0.1% by mass to 1% by mass.
The content of alkoxysilane in the fibers contained in the nonwoven fabric according to the present disclosure is 1% by mass or less with respect to the total mass of the fibers contained in the nonwoven fabric, from the viewpoint of suppressing deterioration of backwash performance when used for a long time. , 0.5% by mass or less, or 0% by mass.

(average fiber diameter)
The average fiber diameter of the fibers contained in the nonwoven fabric of the present disclosure is not particularly limited as long as the filtering performance required for the filter medium of the filter can be obtained. The average fiber diameter of the fibers may be, for example, 13.0 μm or less, preferably 4.0 μm or less, more preferably 3.0 μm or less, from the viewpoint of collecting smaller particles. .
Moreover, from the viewpoint of maintaining the strength when used as a filter, the average fiber diameter of the fibers is preferably 0.1 μm or more, more preferably 0.5 μm or more.

The method for measuring the average fiber diameter is as follows.
Using an electron microscope (model number: S-3500N, manufactured by Hitachi Ltd.), the surface of the nonwoven fabric is photographed at a magnification of 1000 times. The width (diameter) of all fibers that can be measured among the fibers in the photograph is measured. This is repeated until 1000 or more fibers are obtained, and the average of the obtained measurement results is taken as the average fiber diameter.

When the nonwoven fabric of the present disclosure is a nonwoven fabric manufactured by the meltblown method described below (hereinafter also referred to as "meltblown nonwoven fabric"), the nonwoven fabric preferably does not contain a solvent component. A solvent component means an organic solvent component capable of dissolving the constituent components of the fibers contained in the nonwoven fabric according to the present disclosure. Examples of solvent components include dimethylformamide (DMF).
Free of solvent components means below the limit of detection by headspace gas chromatography.

The fibers of the nonwoven fabric of the present disclosure preferably have entanglement points where the fibers are self-fused. The self-fused entangled point means a branched portion where the fibers are bonded to each other by fusing the fibers contained in the nonwoven fabric according to the present disclosure, and the entangled point formed by bonding the fibers to each other via the binder resin. is distinguished from
The self-fused entangled points are formed, for example, in the process of thinning the fibrous propylene-based polymer by the meltblown method.
Whether or not the fibers have self-fused entanglement points can be confirmed by an electron micrograph.

When the fibers of the nonwoven fabric of the present disclosure have entanglement points due to self-fusion, it is not necessary to use an adhesive component for bonding the fibers together. For example, in the case of a meltblown nonwoven fabric in which fibers have entangled points due to self-fusion, resin components other than the thermoplastic resin and specific silylated polyolefin contained in the fibers contained in the nonwoven fabric according to the present disclosure may not be contained. .

The specific surface area of the nonwoven fabric is preferably 0.2 m ² /g to 20.0 m ² /g, more preferably 1.0 m ² /g to 15.0 m ² /g, from the viewpoint of further improving collection efficiency. is more preferable, and more preferably 3.5 m ² /g to 10.0 m ² /g.
The specific surface area of the nonwoven fabric is a value determined according to JIS Z8830:2013.
By setting the average fiber diameter and the specific surface area of the nonwoven fabric within the above ranges, when used as a filter, the balance between collection efficiency and pressure loss is excellent.

The average pore size of the nonwoven fabric of the present disclosure is preferably 10.0 μm or less, more preferably 3.0 μm or less, and even more preferably 2.5 μm or less.
The average pore size of the nonwoven fabric is preferably 0.01 μm or more, more preferably 0.1 μm or more. When the average pore size is 0.01 μm or more, the pressure loss tends to be suppressed and the flow rate can be maintained when the nonwoven fabric is used for the filter.

The maximum pore size of the nonwoven fabric of the present disclosure is preferably 20.0 μm or less, more preferably 6.0 μm or less, and even more preferably 5.0 μm or less.
Moreover, the minimum pore size of the nonwoven fabric is preferably 0.01 μm or more, more preferably 0.1 μm or more.

The pore size (average pore size, maximum pore size and minimum pore size) of the nonwoven fabric of the present disclosure can be measured by the bubble point method. Specifically, in accordance with JIS Z8703: 1983 (standard conditions of the test location), in a temperature-controlled room at a temperature of 20 ± 2 ° C and a humidity of 65 ± 2%, a fluorine-based inert liquid (for example, 3M manufactured by Porous Materials, Inc., product name: Fluorinert), and the pore size is measured with a capillary flow porometer (eg, manufactured by Porous Materials, Inc., product name: CFP-1200AE).

The basis weight of the nonwoven fabric of the present disclosure can be appropriately set depending on the application, and is usually 1 g/m ² to 200 g/m ² , preferably in the range of 2 g/m ² to 150 g/m ² . The basis weight can be adjusted to a desired basis weight by, for example, changing the speed of the collector.
The porosity of the nonwoven fabric of the present disclosure is usually 20% or more, preferably in the range of 20% to 98%, more preferably in the range of 60% to 95%. The porosity can be adjusted to a desired porosity by, for example, calendering after collection on a collector.
When the nonwoven fabric of the present disclosure is embossed, the porosity of the nonwoven fabric means the porosity at locations excluding embossing points.
The porosity is a value defined by the following formula.
(1-((basis weight × 10 ⁶ )/(thickness × density))
The unit of each is g/m ² for basis weight, mm for thickness, and g/mm ³ for density.
The basis weight (g/m ² ) is a value obtained by taking 10 sections of 100 mm in the machine direction (MD direction) × 100 mm in the transverse direction (CD direction) from the nonwoven fabric, measuring the weight of each, and converting it to the weight per unit area. is the average value of
For the thickness (mm), 10 sections of 100 mm in the machine direction (MD direction) x 100 mm in the transverse direction (CD direction) were taken from the nonwoven fabric, and the thickness was measured at 5 points near the four corners and 5 points near the center, for a total of 50 points. is the average of the values. The thickness gauge load is 7 g/cm ² .

In the nonwoven fabric of the present disclosure, the volume occupied by portions having a porosity of 20% or more is preferably 90% or more, and more preferably almost all portions have a porosity of 40% or more. If the nonwoven fabric of the present disclosure is used in a filter, it is preferably not embossed or not embossed in substantially all areas.
When the filter is not embossed, the pressure loss when the fluid is passed through the filter is suppressed, and the length of the filter flow path is increased, so that the filtering performance tends to be improved.
When the nonwoven fabric of the present disclosure is a nonwoven fabric laminate laminated to another nonwoven fabric, the other nonwoven fabric may be embossed.

The air permeability of the nonwoven fabric is measured by Frazier air permeability measurement defined in JIS L 1096:2010. The air permeability of the nonwoven fabric is preferably 3 cm ³ /cm ² /s to 30 cm ³ /cm ² /s, more preferably 5 cm ³ /cm ² /s to 20 cm ³ /cm ² /s, still more preferably 8 cm ³ /cm ² /s to 12 cm ³ /cm ² /s.

<Method for manufacturing nonwoven fabric>
The method for producing the nonwoven fabric of the present disclosure is not particularly limited, and known methods such as air through method, spunbond method, needle punch method, meltblown method, card method, heat fusion method, hydroentanglement method, solvent bonding method, etc. are applied. be able to.
Among these, the method for producing a nonwoven fabric is preferably a meltblown method or a spunbond method, from the viewpoint of obtaining a nonwoven fabric having excellent overall performance of uniformity, low lint, flexibility and filterability. More preferably, it is the law.
That is, one of the preferred forms of the nonwoven fabric of the present disclosure is a configuration containing a meltblown nonwoven fabric. The nonwoven fabric of the present disclosure may be a nonwoven fabric composed of one or more meltblown nonwoven fabric layers, or may be a nonwoven fabric composed of one or more meltblown nonwoven fabric layers and another nonwoven fabric layer. .

As a general method for producing a spunbond nonwoven fabric, for example, a resin composition containing a thermoplastic resin and a specific silylated polyolefin is melted using an extruder, and the melted composition is passed through a plurality of spinnerets. After melt spinning using a spunbond nonwoven fabric forming machine having a spunbond nonwoven fabric forming machine, the long fibers formed by spinning are cooled and stretched as necessary, deposited on the collection surface of the spunbond nonwoven fabric forming machine, and embossed with an emboss roll. A method of heating and pressurizing may be mentioned.
The method of cooling and drawing includes, for example, an open spunbond method disclosed in Japanese Patent Publication No. 48-28386, in which melt-spun long fibers are drawn while being cooled in the atmosphere, and, for example, The closed spunbond method disclosed in Japanese Patent No. 3442896 is widely known.

For the meltblown nonwoven fabric, for example, a manufacturing method having the following steps can be mentioned.
1) A step of extruding a molten resin composition (containing a thermoplastic resin and a specific silylated polyolefin) from a spinneret together with a heated gas by a meltblown method to form a fibrous resin composition 2) Fibrous resin composition is collected in the form of a web

The meltblown method is one of the fleece forming methods in the production of meltblown nonwoven fabrics. When a molten resin composition is extruded from a spinneret in a fibrous form, a heated compressed gas is applied to both sides of the extruded material in a molten state, and the heated compressed gas is accompanied by the extruded material to reduce the diameter of the extruded material. can be done.

Specifically, in the meltblown method, for example, a raw material resin composition is melted using an extruder or the like. The melted resin composition is introduced into a spinneret connected to the tip of the extruder and discharged in the form of fibers from the spinning nozzle of the spinneret. By pulling the ejected fibrous molten resin composition with high-temperature gas (for example, air), the fibrous molten resin composition is finely divided.

The extruded fibrous molten resin composition is pulled by high-temperature gas and thinned to a diameter of usually 1.4 μm or less, preferably 1.0 μm or less. Preferably, the fibrous molten resin composition is attenuated to the limit of the hot gas.

A high voltage may be applied to the fine fibrous molten resin composition to further fine it. When a high voltage is applied, the fibrous molten resin composition is pulled toward the collection side by the attractive force of the electric field and becomes finer. The applied voltage is not particularly limited, and may be 1 kV to 300 kV.

In addition, the fibrous molten resin composition may be further thinned by being irradiated with heat rays. By irradiating with heat rays, it is possible to re-melt the fibrous resin composition which has been thinned and whose fluidity has decreased. Moreover, the melt viscosity of the fibrous resin composition can be further lowered by irradiating with heat rays. Therefore, even if a propylene-based polymer having a large molecular weight is used as a spinning raw material, sufficiently fine fibers can be obtained, and a high-strength meltblown nonwoven fabric can be obtained.

A heat ray means an electromagnetic wave with a wavelength of 0.7 μm to 1000 μm, and particularly near infrared rays with a wavelength of 0.7 μm to 2.5 μm. The intensity and irradiation dose of the heat rays are not particularly limited as long as the fibrous molten resin composition, for example, the fibrous molten propylene-based polymer is remelted. For example, a near-infrared lamp or a near-infrared heater of 1V to 200V, preferably 1V to 20V can be used.

The fibrous molten resin composition is collected in the form of a web. Generally, it is collected and deposited in a collector. Calendering may be performed after collection on the collector. Thereby, a meltblown nonwoven fabric is produced. The produced meltblown nonwoven fabric is wound into a roll, for example. Examples of collectors include perforated belts, perforated drums, and the like. The collector may also have an air collecting portion, which may facilitate collection of the fibers.

<Manufacturing equipment for meltblown nonwoven fabric>
A production apparatus for producing the meltblown nonwoven fabric of the present disclosure is not particularly limited as long as it can produce the meltblown nonwoven fabric of the present disclosure.
Examples of manufacturing equipment for meltblown nonwoven fabrics include:
1) an extruder for melting and conveying a resin composition;
2) a spinneret for discharging the molten resin composition conveyed from the extruder in a fibrous form;
3) a gas nozzle for injecting hot gas at the bottom of the spinneret;
4) a collector for collecting the fibrous molten resin composition discharged from the spinneret in the form of a web;
can be mentioned.

The extruder is not particularly limited, and may be a single-screw extruder or a multi-screw extruder. A solid resin composition charged from a hopper is melted in the compression section.

A spinneret is located at the tip of the extruder. A spinneret usually comprises a plurality of spinning nozzles, for example, a plurality of spinning nozzles arranged in a row. The diameter of the spinning nozzle is preferably between 0.05 mm and 0.38 mm. A molten resin composition is conveyed to a spinneret by an extruder and introduced into a spinning nozzle. A fibrous molten resin composition is discharged from the opening of the spinning nozzle. The discharge pressure of the molten resin composition is usually in the range of 0.01 kg/cm ² to 200 kg/cm ² and preferably in the range of 10 kg/cm ² to 30 kg/cm ² . Mass production is realized by increasing the discharge amount.

The gas nozzle injects hot gas below the spinneret, more specifically near the opening of the spinning nozzle. The propellant gas can be air. It is preferable to provide a gas nozzle in the vicinity of the opening of the spinning nozzle to inject a high-temperature gas onto the resin composition immediately after being discharged from the nozzle opening.

The speed of the jetted gas (discharge air volume) is not particularly limited, and may be 150 Nm ³ /h/m to 1500 Nm ³ /h/m. The temperature of the injected gas is usually 5°C to 400°C or less, preferably 140°C to 350°C. The type of gas to be injected is not particularly limited, and compressed air may be used.

The apparatus for producing a meltblown nonwoven fabric may further comprise voltage applying means for applying a voltage to the fibrous molten resin composition discharged from the spinneret.
Further, a heat ray irradiation means for irradiating the fibrous molten resin composition extruded from the spinneret with heat rays may be further provided.

The collector that collects in the form of a web is not particularly limited, and for example, the fibers may be collected on a perforated belt. The mesh width of the perforated belt is preferably 5 to 200 mesh. Furthermore, an air collecting portion may be provided on the back side of the fiber collecting surface of the perforated belt to facilitate collection. The distance from the collecting surface of the collector to the nozzle opening of the spinning nozzle is preferably 3 cm to 55 cm. Also, it may be collected on the collector while sucking from the back side of the collector.

The meltblown nonwoven fabric manufacturing apparatus may further include a pair of rolls with a clearance between the flat rolls or the crown rolls, or rolls to which a constant pressure can be applied without a clearance. The fibers collected on the web are calendered by passing through rolls to adjust the porosity.

《Nonwoven fabric laminate》
(First embodiment)
A first embodiment of the nonwoven fabric laminate of the present disclosure includes a nonwoven layer A, which is the nonwoven fabric of the present disclosure described above, and a layer B other than the nonwoven layer A.
Since the nonwoven fabric laminate of the first embodiment includes the layer B together with the nonwoven fabric layer A, it is excellent in water pressure resistance and its maintainability. In particular, since the layer B has a function of supporting the nonwoven fabric layer A, the nonwoven fabric of the present disclosure constituting the nonwoven fabric layer A is less likely to be deformed, damaged, etc., and the nonwoven fabric laminate tends to be more excellent in water pressure resistance. Furthermore, since the layer B has a function of supporting the nonwoven fabric layer A, the strength of the nonwoven fabric laminate tends to be improved. Moreover, since the nonwoven fabric layer A is included in the nonwoven fabric layered product of the first embodiment, it is excellent in backwashability and maintainability thereof.

The layer B in the first embodiment is not particularly limited as long as it is a layer other than the nonwoven fabric layer A that is the nonwoven fabric of the present disclosure described above, and is a resin film such as a porous film, woven fabric, knitted fabric, paper, or Layers composed of nonwoven fabrics other than nonwoven fabrics, and the like are included.

Examples of nonwoven fabrics that can constitute Layer B in the first embodiment include spunbond nonwoven fabrics, meltblown nonwoven fabrics, wet nonwoven fabrics, spunlace nonwoven fabrics, dry nonwoven fabrics, dry pulp nonwoven fabrics, air-laid nonwoven fabrics, water jet nonwoven fabrics, flash spun nonwoven fabrics, open Various known short-fiber nonwoven fabrics and long-fiber nonwoven fabrics (for example, long-fiber cellulose nonwoven fabrics), such as fiber nonwoven fabrics and needle-punched nonwoven fabrics, can be used. Above all, the nonwoven fabric preferably contains a spunbonded nonwoven fabric, that is, the layer B preferably contains a spunbonded nonwoven fabric layer, from the viewpoint that the nonwoven fabric laminate is superior in water pressure resistance and maintainability thereof. Including the spunbond nonwoven fabric in the layer B tends to further improve the strength of the nonwoven fabric laminate.

The nonwoven fabric layer A in the first embodiment may be a nonwoven fabric composed of one layer of the nonwoven fabric of the present disclosure, or may be a nonwoven fabric composed of two or more layers of the nonwoven fabric of the present disclosure.
The layer B in the first embodiment may be one layer or two or more layers. When Layer B is two or more layers, the two or more layers may be the same or different.

A preferred embodiment in the case where the layer B is a nonwoven fabric layer B made of nonwoven fabric will be described below.
The fibers contained in the nonwoven fabric layer B in the first embodiment may contain a thermoplastic resin. The thermoplastic resin includes, for example, the thermoplastic resin contained in the fibers in the nonwoven fabric of the present disclosure described above. Preferred physical properties of the thermoplastic resin contained in the nonwoven fabric layer B are the same as the preferred physical properties of the thermoplastic resin contained in the fibers in the nonwoven fabric of the present disclosure described above. Among them, the thermoplastic resin preferably contains polyolefin, preferably contains at least one selected from polyethylene and polypropylene, and preferably contains polypropylene.
Polyethylene is preferably a polymer containing 50% by mass or more of ethylene units.
As the polypropylene, a polymer containing 50% by mass or more of propylene units is preferable, and a polymer containing 100% by mass of propylene units (that is, a homopolymer of propylene) is more preferable.
The content of polyolefin, the total content of polyethylene and polypropylene, or the content of polypropylene may be 50% by mass to 100% by mass, or 80% by mass to 100% by mass, based on the total thermoplastic resin. may

The content of the thermoplastic resin in the nonwoven fabric layer B in the first embodiment is preferably 90% by mass or more, more preferably 95% by mass or more, relative to the total mass of fibers contained in the nonwoven fabric. The upper limit of the thermoplastic resin content is not particularly limited as long as it is 100% by mass or less with respect to the total mass of fibers contained in the nonwoven fabric.

The nonwoven fabric layer B in the first embodiment may or may not contain the aforementioned specific silylated polyolefin and the aforementioned known additive independently.

The average fiber diameter of the fibers contained in the nonwoven fabric layer B in the first embodiment is not particularly limited. The average fiber diameter of the fibers is preferably 5.0 µm or more, more preferably 10 µm or more, and even more preferably 12 µm or more, from the viewpoint that the nonwoven fabric laminate is superior in water pressure resistance and durability. The upper limit of the average fiber diameter of the fibers is not particularly limited, and may be, for example, 30 μm or less.

The basis weight of the nonwoven fabric layer B in the first embodiment can be appropriately set depending on the application, and is usually in the range of 1 g/m ² to 200 g/m ² and preferably in the range of 2 g/m ² to 150 g/m ² . preferable. The basis weight can be adjusted to a desired basis weight by, for example, changing the speed of the collector.
The porosity of the nonwoven fabric layer B in the first embodiment is usually 20% or more, preferably in the range of 20% to 98%, more preferably in the range of 60% to 95%. The porosity can be adjusted to a desired porosity by, for example, calendering after collection on a collector.

<Method for manufacturing nonwoven fabric laminate>
The method for producing the nonwoven fabric laminate in the first embodiment is not particularly limited. When the layer B is the nonwoven fabric layer B, the nonwoven fabric layer of the first embodiment can be obtained by manufacturing the nonwoven fabric of the present disclosure and a nonwoven fabric other than the nonwoven fabric of the present disclosure, and laminating these nonwoven fabrics. The method for laminating these nonwoven fabrics is not particularly limited, and includes thermal embossing, thermal fusion methods such as ultrasonic fusion, mechanical entangling methods such as needle punching and hydroentangling, hot melt adhesives, and urethane adhesives. A method using an adhesive such as an adhesive agent is exemplified.

Alternatively, one of the nonwoven fabrics of the present disclosure or the nonwoven fabric other than the nonwoven fabric of the present disclosure is produced, the other nonwoven fabric of the disclosure or the nonwoven fabric other than the nonwoven fabric of the present disclosure is deposited on one of the produced nonwoven fabrics, and then the The nonwoven fabric laminate in the first embodiment can be obtained by laminating the nonwoven fabrics by the method described above.

When the layer B is a layer composed of a non-woven fabric, for example, a resin film such as a porous film, a woven fabric, a knitted fabric, a base material such as paper, etc., the non-woven fabric of the present disclosure is formed on the base material provided in advance on the collector. The nonwoven laminate in the first embodiment may be obtained by depositing the fibers in a web and then laminating the nonwoven and substrate by the methods described above.

(Second embodiment)
A second embodiment of the nonwoven fabric laminate of the present disclosure includes a nonwoven layer A that is the nonwoven fabric of the present disclosure, a layer B that is other than the nonwoven layer A, and a layer C that is other than the nonwoven layer A. Layer B, said nonwoven fabric layer A and said layer C are arranged in this order.
The nonwoven fabric laminate of the second embodiment includes the layers B and C together with the nonwoven fabric layer A, so that it is excellent in water pressure resistance and its maintainability. Moreover, the nonwoven fabric layered product of 2nd Embodiment is excellent in backwashability and its maintainability by including the nonwoven fabric layer A.
Furthermore, since the layer B and the layer C are located on both sides of the nonwoven fabric layer A, the nonwoven fabric laminate of the second embodiment tends to be superior in strength compared to the embodiment with only the nonwoven fabric layer A, and is easy to handle. Excellent in nature.

The layers B and C in the second embodiment are not particularly limited as long as they are layers other than the nonwoven fabric layer A, which is the nonwoven fabric of the present disclosure. Resin films such as porous films, woven fabrics, knitted fabrics, paper, Examples thereof include layers composed of nonwoven fabrics other than the nonwoven fabric of the present disclosure.

The nonwoven fabrics that can constitute the layers B and C in the second embodiment are the same as the nonwoven fabrics that can constitute the layer B in the first embodiment. Layers B and C in the second embodiment may be composed of the same type of nonwoven fabric, or may be composed of different types of nonwoven fabric. Among them, from the viewpoint that the nonwoven fabric laminate is excellent in water pressure resistance and its maintainability, at least one of the nonwoven fabric contained in the layer B and the nonwoven fabric contained in the layer C preferably contains a spunbond nonwoven fabric. preferably includes a spunbond nonwoven layer. Among them, the nonwoven fabric contained in the layer B and the nonwoven fabric contained in the layer C more preferably contain a spunbond nonwoven fabric from the viewpoint that the nonwoven fabric laminate is more excellent in water pressure resistance and its maintainability. More preferably, it includes a spunbond nonwoven layer. When Layer B and Layer C contain spunbond nonwoven layers, the strength of the nonwoven fabric laminate tends to be further improved.

The nonwoven fabric layer A in the second embodiment may be a nonwoven fabric composed of one layer of the nonwoven fabric of the present disclosure, or may be a nonwoven fabric composed of two or more layers of the nonwoven fabric of the present disclosure.
Layer B and layer C in the second embodiment may each independently be one layer or two or more layers. When at least one of Layer B and Layer C is two or more layers, the two or more layers may be the same or different.
Layer B and layer C may be made of the same material or may be the same layer.

A preferred embodiment in which the layer B in the second embodiment is the nonwoven fabric layer B made of nonwoven fabric and the layer C in the second embodiment is the nonwoven fabric layer C made of nonwoven fabric will be described below.

In the nonwoven fabric laminate in the second embodiment, a nonwoven fabric layer B containing a spunbond nonwoven fabric layer, a nonwoven fabric layer A, and a nonwoven fabric layer C containing a spunbond nonwoven fabric layer are preferably laminated in this order. more preferably comprises a meltblown nonwoven layer. The nonwoven fabric layer A, the nonwoven fabric layer B, and the nonwoven fabric layer C may each independently be one nonwoven fabric layer, or two or more nonwoven fabric layers.

The preferred forms of the nonwoven fabric layer B and the nonwoven fabric layer C in the second embodiment are the same as the preferred forms of the nonwoven fabric layer B in the first embodiment.

Preferred embodiments of the nonwoven fabric laminate of the present disclosure, including the nonwoven fabric laminate of the first embodiment and the nonwoven fabric laminate of the second embodiment, will be described below.

The nonwoven fabric laminate of the present disclosure preferably has a fused or bonded portion that fuses or bonds at least a portion of the nonwoven fabric contained in the nonwoven fabric laminate. Since the nonwoven fabric laminate has a fused part or a bonded part, the force applied to the fibers contained in the nonwoven fabric laminate when water pressure is applied to the nonwoven fabric laminate is dispersed to the fused part or the bonded part, thereby forming a nonwoven fabric laminate. water pressure resistance tends to be more improved.

The area ratio of the fused part or the bonded part is preferably 1% to 30%, more preferably 5% to 25%, from the viewpoint of the fused strength or adhesive strength of the nonwoven fabric laminate and the water pressure resistance of the nonwoven fabric laminate. is more preferably 7% to 20%.

The nonwoven fabric laminate of the present disclosure has at least one of the properties of being excellent in water pressure resistance and its maintainability, and the properties of being able to be applied as a filter medium of a filter and having excellent backwashing properties and its maintainability. You don't have to have both.

<Method for manufacturing nonwoven fabric laminate>
The manufacturing method of the nonwoven fabric laminate in the second embodiment is not particularly limited. When the layer B is the nonwoven fabric layer B and the layer C is the nonwoven fabric layer C, the nonwoven fabrics constituting the nonwoven fabric layers A to C are produced respectively, and these nonwoven fabrics are laminated to form the nonwoven fabric laminate in the second embodiment. Obtainable. The method for laminating these nonwoven fabrics is not particularly limited, and includes thermal embossing, thermal fusion methods such as ultrasonic fusion, mechanical entangling methods such as needle punching and hydroentangling, hot melt adhesives, and urethane adhesives. A method using an adhesive such as an adhesive agent is exemplified.

Alternatively, one of the nonwoven fabric constituting the nonwoven fabric layer B and the nonwoven fabric constituting the nonwoven fabric layer C is manufactured, and the nonwoven fabric of the present disclosure and the nonwoven fabric constituting the nonwoven fabric layer B or the nonwoven fabric layer C are formed on one of the manufactured nonwoven fabrics. The nonwoven fabric laminate in the second embodiment can be obtained by depositing the other nonwoven fabric in order and then laminating these nonwoven fabrics by the method described above.

When the nonwoven fabric layer A is a meltblown nonwoven fabric layer and the nonwoven fabric layers B and C are spunbond nonwoven fabric layers, for example, the nonwoven fabric laminate in the second embodiment can be produced through the following steps.
1) A resin composition containing a thermoplastic resin is melted using an extruder, the melted composition is melt-spun using a spunbond nonwoven fabric molding machine having a plurality of spinnerets, and a length formed by spinning is formed. After the fibers are cooled and stretched as necessary, they are deposited on the collection surface of a spunbond nonwoven fabric molding machine to obtain a nonwoven web. containing a silylated polyolefin.) is discharged from a spinneret together with a heated gas to form a fibrous resin composition; Step of depositing on a woven web 4) A resin composition containing a thermoplastic resin is melted using an extruder, and the melted composition is melt-spun using a spunbond nonwoven fabric molding machine having a plurality of spinnerets. , After cooling and stretching the long fibers formed by spinning as necessary, depositing them on the nonwoven web obtained in 3) 5) By subjecting the three-layer nonwoven web to heat embossing Process of laminating three layers of nonwoven fabric

When heat embossing is performed as a method for laminating these nonwoven fabrics, the stamped area ratio of the embossing roll is preferably 1% to 30%, more preferably 5% to 25%, and more preferably 7% to 20%. is more preferable.
The temperature of the embossing roll during hot embossing is preferably 80°C to 140°C, more preferably 90°C to 130°C, even more preferably 95°C to 125°C.

<Application>
Applications of the nonwoven fabrics and nonwoven fabric laminates of the present disclosure include, for example, filters such as gas filters (air filters) and liquid filters, wipers, protective clothing, medical gowns (especially disposable protective clothing and disposable medical gowns). (liquid shielding article) such as a medical material such as a liquid shielding article.
In particular, as the use of the nonwoven fabric of the present disclosure, filters such as gas filters (air filters) and liquid filters are preferable, and as the use of the nonwoven fabric laminate of the present disclosure, protective clothing, medical gowns (especially disposable protective clothing Liquid barrier articles such as medical materials such as disposable medical gowns) are preferred.

When the nonwoven fabric of the present disclosure comprises a meltblown nonwoven fabric, the meltblown nonwoven fabric is 1) free of solvent components, 2) free of adhesive components for bonding fibers together, and 3) non-embossed. When at least one of 1) to 3) is satisfied, the content of impurities is reduced. Therefore, such a nonwoven fabric has high cleanability and filtering performance, and is suitably used as a high-performance filter.

The liquid filter may consist of a single layer of nonwoven fabric or may consist of a laminate of two or more layers of nonwoven fabric. Moreover, the liquid filter may be made of a laminate of a nonwoven fabric and a resin film. When a laminate of two or more layers of nonwoven fabric is used as the liquid filter, the two or more layers of nonwoven fabric may simply be stacked.
In addition, the liquid filter may be a nonwoven fabric combined with another nonwoven fabric depending on the purpose and the liquid to be applied. Moreover, in order to increase the strength of the liquid filter, a spunbonded nonwoven fabric may be used, or a spunbonded nonwoven fabric and a net-like material may be laminated.

The liquid filter may be calendered using, for example, a pair of rolls provided with a clearance between flat rolls or crown rolls to control the pore size and porosity to be small, or rolls to which a constant pressure can be applied without a clearance. . It is necessary to change the clearance between the rolls appropriately according to the thickness of the nonwoven fabric so as not to eliminate voids between the fibers of the nonwoven fabric.

When heat treatment is performed during calendering, it is desirable that the roll surface temperature is in the range of 15°C to 50°C lower than the melting point of the fibers formed from the resin composition. When the roll surface temperature is 15° C. or more lower than the melting point of the resin formed from the resin composition, film formation on the surface of the meltblown nonwoven fabric tends to be suppressed, and deterioration in filter performance tends to be suppressed.

In the nonwoven fabric laminate of the present disclosure, the nonwoven fabric layer B containing the spunbond nonwoven fabric layer, the nonwoven fabric layer A containing the meltblown nonwoven fabric layer, and the nonwoven fabric layer C containing the spunbond nonwoven fabric layer are preferably laminated in this order. With this configuration, the nonwoven fabric layer B and the nonwoven fabric layer C contribute to the strength of the nonwoven fabric laminate, and tend to be more excellent in water pressure resistance and its maintainability. Furthermore, from the viewpoint of further improving the water pressure resistance of the nonwoven fabric laminate, the nonwoven fabric laminate preferably has a fused part or an adhesive part that fuses or bonds at least a part of the nonwoven fabric contained in the nonwoven fabric laminate.

The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to these examples.

(Method of measurement and calculation)
Molecular weight, yield, conversion rate, isomerization rate, and melt mass flow rate (MFR) were measured and calculated by the methods described below.

[m1] Method for measuring molecular weight (polyethylene)
The number average molecular weight Mn, weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn) of polyethylene, which is the raw material of the specific silylated polyolefin, were measured by the GPC method using Millipore GPC-150 as follows. .
That is, the separation column was TSK GNH HT, and the column size used was 7.5 mm in diameter and 300 mm in length. The column temperature was 140° C., and ortho-dichlorobenzene (Fuji Film Wako Pure Chemical Industries, Ltd.) was used as the mobile phase, and BHT (Takeda Pharmaceutical Co., Ltd.) 0.025% by mass was used as the antioxidant. moved in minutes. The sample concentration was 0.1% by mass, and the sample injection amount was 500 microliters.
Using a differential refractometer as a detector, it was determined as a polystyrene equivalent value. Then, based on the polystyrene equivalent values, they were converted into polyethylene equivalent values by the universal calibration method.
In addition, in the following synthesis examples, the number of moles of the raw material polymer is all expressed as a value based on Mn.

[m2] Measurement of molecular weight (polypropylene)
The weight-average molecular weight (Mw) of polypropylene was determined by gel permeation chromatography as a polystyrene-equivalent value measured using the following equipment and conditions. Then, based on the polystyrene conversion value, it was converted to polypropylene by the universal calibration method, and the weight average molecular weight of the polyolefin other than the specific silylated polyolefin was determined [GPC measurement device]
Column: TOSO GMHHR-H (S) HT (manufactured by Tosoh Corporation)
Detector: RI detector for liquid chromatogram WATERS 150C (manufactured by Waters)
[Measurement condition]
Solvent: 1,2,4-trichlorobenzene Measurement temperature: 145°C
Flow rate: 1.0 mL/min Sample concentration: 2.2 mg/mL
Injection volume: 160 μL
Calibration curve: Universal Calibration
Analysis program: HT-GPC (Ver.1.0)

[m3] Method for measurement and calculation of yield, conversion, isomerization, terminal unsaturation, number of double bonds per 1,000 carbon atoms by NMR analysis Yield, conversion, isomerization, terminal of silylated polyolefin The degree of unsaturation, the number of double bonds per 1,000 carbons, is determined by ¹ H-NMR. Yield is the ratio of the number of moles of silylated polyolefin obtained to the number of moles of vinyl group-containing compound as a raw material, conversion rate is the ratio of the number of moles consumed to the number of moles of vinyl group-containing compound as a raw material, and isomerization rate. is the ratio of the number of moles of the vinylene body produced to the number of moles of the vinyl group-containing compound as the raw material, The ratio of terminal vinyl groups and the number of vinyl groups per 1,000 carbon atoms are defined as the ratio of the number of vinyl groups to the number of carbon atoms derived from the number of protons corrected to the number of vinyl groups per 1,000 carbon atoms. The terminal unsaturation rate and the number of vinyl groups per 1,000 carbon atoms are generally applied to the raw material vinyl group-containing compound. may also apply to silylated polyolefins as

For example, a silylated polyolefin obtained by hydrosilylating a main chain end vinyl group-containing compound consisting only of ethylene with triethoxysilane has a peak (C) corresponding to 6 protons of the ethoxy group methylene of 3.8 ppm, and an isomerized vinylene group. A peak (D) corresponding to two protons of is observed at 5.4 ppm. When the hydrosilylation is insufficient, the peak (E) for 2 protons of the unreacted vinyl group is observed at 4.8 ppm to 5.1 ppm, and the peak (F) for 1 proton is observed at 5.6 to 5.8 ppm. be. Regarding the raw material vinyl group-containing compound, the main chain methylene (G) for 2 protons was observed at 1.0 ppm to 1.5 ppm. ) is observed at 0.8 ppm. Furthermore, a peak (I) for two protons on the carbon adjacent to the double bond is observed at 1.9 ppm.
If the peak areas of each peak (C), (D), (E), (F), (G), (H) and (I) are respectively SC, SD, SE, SF, SG, SH and SI , yield (YLD (%)), conversion rate (CVS (%)), isomerization rate (ISO (%)), terminal unsaturation rate (VE (%)), number of double bonds per thousand carbons ( VN (pieces/1000C)) is calculated by the following formula.
YLD (%) = (SC/3)/(SC/3 + SD + SE) x 100
CVS (%) = {1-SE/(SC/3+SD+SE)}×100
ISO (%) = SD / (SC / 3 + SD + SE) x 100
VE (%) = SE/(SE/2+SH/3) x 100
VN (pcs/1000C)=(SE+SF)/3×1000/{(SD+SE+SF+SG+SH+SI)/2}

[m4] Melt mass flow rate (MFR) measurement method MFR was measured according to ASTM D-1238-04.
The melt mass flow rate (MFR) of polyethylene as the vinyl group-containing compound was measured using a melt indexer T-111 manufactured by Tokyo Seiki Co., Ltd. at 190° C. under a load of 2160 g.
The MFR of polypropylene as a thermoplastic resin was measured using a melt indexer T-111 manufactured by Tokyo Seiki Co., Ltd. at 230° C. under a load of 2160 g.

[Example 1]
<Preparation of resin composition>
99.0 parts by mass of polypropylene (product name: Achieve 6936G2, ExxonMobil, Inc., weight average molecular weight: 55,000, MFR; 1550 g/10 min, PP) as a thermoplastic resin, and silyl obtained as follows: and 1.0 parts by mass of the modified polyolefin (A) were mixed to obtain a resin composition.
Silylated polyolefin (A) is a specific silylated polyolefin.

~Synthesis of silylated polyolefin (A)~
In a 50 mL sample tube, 0.5 g of platinum (II) chloride was suspended in hydrosilane A (HS(A), Gelest, Inc., DMS-H11) (10 mL) and stirred at room temperature for 190 hours under a nitrogen stream. After that, it was filtered using a PTFE filter (0.45 μm) to obtain a platinum catalyst composition (C-1, platinum concentration: 3.8% by weight).
A 300 mL two-necked flask was charged with a one-end vinyl group-containing ethylene polymer (Mw = 4770, Mw/Mn = 2.25 (GPC), terminal Unsaturation rate: 97%) 25.1 g (11.8 mmol) was charged, and under a nitrogen atmosphere, hydrosilane A (HS(A)) 8.7 g (5.9 mmol; equivalent to 11.8 mmol as Si—H group). Then, 150 μL (1.4×10 ⁻⁶ mmol in terms of Pt) of platinum catalyst composition (C-1) obtained by the above method diluted 200-fold with hydrosilane A (HS(A)) was charged. .
The reactor was set in an oil bath whose internal temperature had been raised to 130° C. in advance, and stirred. After about 3 minutes the polymer melted. After 6 hours, it was cooled, about 200 mL of methanol was added, and the contents were taken out in a 300 mL beaker and stirred for 2 hours. Thereafter, the solid was collected by filtration, washed with methanol, and dried at 60° C. under reduced pressure of 2 hPa or less to obtain 33.1 g of silylated polyolefin (A) as a white solid.
As a result of NMR analysis, the obtained silylated polyolefin (A) had a yield of 98%, an olefin conversion rate of 100%, and an isomerization rate of 2%. The MFR was greater than the upper limit of measurement (MFR>100 g/10 min), and the polydimethylsiloxane content in the silylated polyolefin (A) calculated from the molecular formula was 26% by mass.

<Production of nonwoven fabric>
The resin composition obtained above is supplied to a die, and heated air (250 ° C. , 300 m ³ /sec), collected by a collector while being sucked from the back side of the collector, passed through rolls and calendered to obtain a meltblown nonwoven fabric.
The resulting meltblown nonwoven fabric had an average fiber diameter of 2.6 μm, a porosity of 81.0%, and a basis weight of 29.2 g/m ² .

<Production of filter>
The meltblown nonwoven fabric obtained above was cut out. The mass of the cut nonwoven fabric was measured.
The cut meltblown nonwoven fabric was placed in a φ47 mm filter holder (stainless line holder type KS-47, Advantec) to prepare a filter.
A total of 12 similar filters were prepared.

〔evaluation〕
(Evaluation 1) Adhesion amount, adhesion amount after backwashing, and adhesion rate after backwashing (before holding in water)
A 50 ppm aqueous dispersion (dust liquid) of polystyrene particles (particle size: 20 μm) was passed through six of the filters obtained above at a flow rate of 20 mL/min for 5 minutes.
Meltblown nonwoven fabrics were taken out from 3 of the 6 filters after passing the liquid, dried, and the mass (mg) was measured.
For the three nonwoven fabrics, the adhesion amount A (mg) before backwashing was determined from the mass (mg) (dry mass) before and after passing the dust liquid through the following formula (A).
Adhesion amount A (mg) before backwashing = (Total mass of 3 nonwoven fabrics after passing dust liquid - Total mass of 3 nonwoven fabrics before passing dust liquid) / 3 (A)
Then, after passing the dust liquid, pure water was passed through the three filters from which the meltblown nonwoven fabric was not removed for 5 minutes at a flow rate of 20 mL/min in the direction opposite to the direction of passing the dust liquid, Backwashed.
The meltblown nonwoven fabric was taken out from the three filters after backwashing, dried, and the mass (mg) after backwashing was measured.
For the three nonwoven fabrics dried after backwashing, the following formula (B ) was used to determine the adhesion amount B (mg) after backwashing.
Adhesion amount B (mg) after backwashing = (Total mass of 3 nonwoven fabrics after backwashing - Total mass of 3 nonwoven fabrics before dust liquid flow) / 3 (B)
Further, from the adhesion amount A (mg) before backwashing and the adhesion amount B (mg) after backwashing, the post-backwashing adhesion rate (%) was obtained by the following formula (C).
Adhesion rate after backwash (%) = (Amount of foreign matter adhered after backwash B/Amount of foreign matter adhered A) x 100 (C)

(Evaluation 2) Adhesion amount, adhesion amount after backwashing, and adhesion rate after backwashing (after being held in water)
The remaining 6 filters that were not subjected to evaluation 1 were immersed in pure water for 7 days.
For the 6 filters after immersion, in the same manner as in Evaluation 1, the adhesion amount A (mg) before backwashing, the adhesion amount B (mg) after backwashing, and the adhesion rate after backwashing (%) were calculated. did.

Table 1 shows the results obtained in Evaluation 1 and Evaluation 2.

[Example 2 and Example 3]
A nonwoven fabric and a filter comprising the same were produced in the same manner as in Example 1 except that the amounts of the silylated polyolefin (A) and polypropylene were changed as shown in Table 1, (Evaluation 1) and (Evaluation 2) were performed. Table 1 shows the results. The nonwoven fabric produced in Example 2 had a porosity of 79.0% and a basis weight of 29.6 g/m ² . The nonwoven fabric produced in Example 3 had a porosity of 80.0% and a basis weight of 30.8 g/m ² .

[Example 4]
A nonwoven fabric and a filter comprising the same were prepared in the same manner as in Example 1, except that polyethylene (PE, product name: SP50800P, Prime Polymer Co., Ltd.) was used as the thermoplastic resin in Example 1 instead of polypropylene. (Evaluation 1) and (Evaluation 2) were performed. Table 1 shows the results. The nonwoven fabric produced in Example 4 had a porosity of 82.0% and a basis weight of 31.1 g/m ² .

[Example 5]
In Example 1, a nonwoven fabric and a filter comprising the same were produced in the same manner as in Example 1, except that nylon 6 (product name: A1020BRL, Unitika Ltd., PA6) was used as the thermoplastic resin instead of polypropylene. (Evaluation 1) and (Evaluation 2) were performed. Table 1 shows the results. The nonwoven fabric produced in Example 5 had a porosity of 81.0% and a basis weight of 29.8 g/m ² .

[Example 6]
A nonwoven fabric and a filter comprising the same were produced in the same manner as in Example 1, except that polybutylene terephthalate (product name: 300FP, Duranex, PBT) was used as the thermoplastic resin in Example 1 instead of polypropylene. (Evaluation 1) and (Evaluation 2) were performed. Table 1 shows the results. The nonwoven fabric produced in Example 6 had a porosity of 79.0% and a basis weight of 30.6 g/m ² .

[Comparative Example 1]
A nonwoven fabric and a filter comprising the same were produced in the same manner as in Example 1, except that the silylated polyolefin (A) was not used, and (Evaluation 1) and (Evaluation 2) were performed. Table 1 shows the results. The nonwoven fabric produced in Comparative Example 1 had a porosity of 78.0% and a basis weight of 31.6 g/m ² .

[Comparative Example 2]
In Example 1, in the same manner as in Example 1, except that methyltrimethoxysilane (product name: LS-530, Shin-Etsu Chemical Co., Ltd., alkoxysilane) was used instead of the silylated polyolefin (A). A nonwoven fabric and a filter including the same were produced, and evaluated (Evaluation 1) and (Evaluation 2). Table 1 shows the results. The nonwoven fabric produced in Comparative Example 2 had a porosity of 82.0% and a basis weight of 29.6 g/m ² .

[Comparative Example 3]
A nonwoven fabric and a filter comprising the same were produced in the same manner as in Example 4, except that the silylated polyolefin (A) was not used in Example 4, and (Evaluation 1) and (Evaluation 2) were performed. Table 1 shows the results. The nonwoven fabric produced in Comparative Example 3 had a porosity of 83.0% and a basis weight of 31.0 g/m ² .

Details of each component in Table 1 are collectively shown below.
PP: polypropylene (product name: Achieve 6936G2, ExxonMobil, weight average molecular weight: 55,000 propylene-based polymer, MFR: 1550 g/10 minutes)
・ PE: polyethylene (product name: SP50800P, Prime Polymer Co., Ltd.)
・PA6: Nylon 6 (product name: A1020BRL, Unitika Ltd.)
・PBT: polybutylene terephthalate (product name: 300FP, Duranex)
・ Silylated PO: "Silylated polyolefin (A)" synthesized above (specific silylated polyolefin)
・ Alkoxysilane: methyltrimethoxysilane (product name: LS-530, Shin-Etsu Chemical Co., Ltd.)

As is clear from Table 1, the nonwoven fabrics included in the filters of Examples 1 to 6 all had good adhesion rates after backwashing in both evaluations before and after holding in water. was done. This means that the nonwoven fabrics included in the filters of Examples 1 to 6 are filter media excellent in backwashability and maintainability.
Moreover, from Examples 1 to 4 and Examples 5 to 6, it can be seen that polyolefin is preferable as the thermoplastic resin, and polypropylene is more preferable.
On the other hand, Comparative Examples 1 and 3 are filters provided with a nonwoven fabric containing no specific silylated polyolefin, and are found to be remarkably inferior in backwashability.
In addition, in Comparative Example 2 in which alkoxysilane was used instead of the specific silylated polyolefin, the backwashability before being kept in water was good, but the backwashability after being kept in water was remarkably poor. It turns out that maintainability cannot be achieved.

[Example 7]
[Manufacture of nonwoven fabric laminate]
<Production of spunbond nonwoven fabric (SB)>
Polypropylene (manufactured by Prime Polymer Co., Ltd.: trade name: Prime Polypro S119; melting point: 156°C, MFR (measured at a temperature of 230°C and a load of 2160g according to ASTM D1238): 62g as a thermoplastic resin for producing a spunbond nonwoven fabric /10 min) was used. The thermoplastic resin was supplied to a die, spun at a set temperature of 230° C., and collected by a collector to obtain a spunbond nonwoven fabric 1 (SB1).

<Production of meltblown nonwoven fabric>
Next, the resin composition prepared in Example 1 is supplied to a die, and heated air is blown from both sides of the nozzle from a die having a set temperature of 270 ° C. and a nozzle diameter of 0.12 mm at a rate of 50 mg / min per single nozzle hole. (270° C., 308 Nm ³ /h/m) together with the above resin composition is discharged onto SB1 on the collector, collected by the collector while being sucked from the back side of the collector, and meltblown nonwoven fabric 1 (MB1) on SB1. manufactured. In addition, a meltblown nonwoven fabric 2 (MB2) was produced on MB1 with the same raw materials and production conditions.

<Production of spunbond nonwoven fabric (SB)>
A spunbond nonwoven fabric 2 (SB2) was then produced on MB2 using the same raw materials and production conditions as SB1.

<Embossing>
Then, heat embossing was performed at 120° C., a nip pressure of 33 kg/cm, and an impression area ratio of 10.2% to fuse each layer to obtain a nonwoven fabric laminate having a four-layer structure of SB1/MB1/MB2/SB2. .

<Measurement of basis weight and porosity>
Each layer was peeled off from the nonwoven fabric laminate obtained without the above-described embossing, and the basis weight and porosity of each of SB1, SB2, MB1 and MB2 were measured by the methods described above. The same values were obtained for SB1 and SB2, and for MB1 and MB2. Table 2 shows the measured values.

<Measurement of average fiber diameter>
The average fiber diameter of the obtained nonwoven fabric laminate was measured by the method described above. MB1 and MB2 were put together and the average fiber diameter was measured as one MB layer. Table 2 shows the measured values.

(Evaluation 3) The water pressure resistance of the obtained nonwoven fabric laminate was measured at a pressurization rate of 600 mm/min ± 30 mm/min in accordance with A method (low water pressure method) specified in JIS L 1092 (2009). . Table 2 shows the results. This value is also called the initial water pressure resistance.

(Evaluation 4) The obtained nonwoven fabric laminate was allowed to stand in water at 60°C for 72 hours. The nonwoven laminate was then removed from the water and allowed to dry at room temperature for 24 hours. After that, the water pressure resistance was measured in the same manner as in Evaluation 3. Table 2 shows the results. This value is also called water pressure resistance after aging.

(Evaluation 5) From the initial water pressure resistance obtained in Evaluation 3 above and the water pressure resistance over time obtained in Evaluation 4 above, the drop rate of water pressure resistance was calculated from the following formula. Table 2 shows the results.
[1-(water pressure resistance after aging / initial water pressure resistance)] × 100 = descent rate (%)

(Evaluation 5) The tensile strength (N/50mm) and elongation (%) of the nonwoven fabric laminate were measured according to JIS L 1906 (2010). Specifically, a test piece having a width of 50 mm and a length of 200 mm was taken from the non-woven fabric laminate, and a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-J) was used with a chuck distance of 100 mm and a head speed. MD: 5 points, CD: 5 points are measured at 300 mm / min, the average value of maximum strength and the average value of elongation at the time of maximum strength measurement are calculated, and tensile strength (N / 50 mm) and elongation (%) are calculated. asked. Table 2 shows the results.

[Example 8]
A nonwoven fabric laminate having a four-layer structure of SB1/MB1/MB2/SB2 was prepared in the same manner as in Example 7 except that the amounts of silylated polyolefin (A) and polypropylene in MB1 and MB2 were changed as shown in Table 2. was produced and evaluated. Table 2 shows the results.

[Comparative Example 4]
In Example 7, a nonwoven fabric laminate having a four-layer structure of SB1/MB1/MB2/SB2 was produced in the same manner as in Example 7, except that the silylated polyolefin (A) was not used in MB1 and MB2, evaluated. Table 2 shows the results.

[Comparative Example 5]
Example 8 except that methyltrimethoxysilane (product name: LS-530, Shin-Etsu Chemical Co., Ltd., alkoxysilane) was used instead of silylated polyolefin (A) in MB1 and MB2. A nonwoven fabric laminate having a four-layer structure of SB1/MB1/MB2/SB2 was prepared and evaluated in the same manner as in the above. Table 2 shows the results.

In Table 2, "-" means that the corresponding component has not been added and that there is no corresponding physical property data.

As is clear from Table 2, it was confirmed that the nonwoven fabric laminates of Examples 7 and 8 had good adhesion rates after backwashing in both evaluations before and after being kept in water. . This means that the nonwoven fabric laminates of Examples 7 and 8 are excellent in backwashability and maintenance.
The initial water pressure resistance and water pressure resistance after time of the nonwoven fabric laminates of Examples 7 and 8 were superior to the initial water pressure resistance and water pressure resistance after time of the nonwoven fabric laminate of Comparative Example 4. Furthermore, the initial water pressure resistance of the nonwoven fabric laminates of Examples 7 and 8 and the initial water pressure resistance of the nonwoven fabric laminate of Comparative Example 5 were about the same, but the water pressure resistance of the nonwoven fabric laminates of Examples 7 and 8 over time was superior to the water pressure resistance after aging in the nonwoven fabric laminate of Comparative Example 5. These facts mean that the nonwoven fabric laminates of Examples 7 and 8 are excellent in water pressure resistance and its maintainability.

The disclosure of Japanese Patent Application 2021-026456 filed on February 22, 2021 is incorporated herein by reference in its entirety.
All publications, patent applications and technical standards mentioned herein are to the same extent as if each individual publication, patent application and technical standard were specifically and individually noted to be incorporated by reference. incorporated herein by reference.

Claims

A nonwoven fabric comprising fibers,
The fibers are
80% by mass or more of the thermoplastic resin with respect to the total mass of the fibers,
A reaction product (1 molecule Silylated polyolefins and derivatives thereof, excluding the reaction product of the silicon-containing compound having two or more SiH groups in the above and the vinyl group-containing compound having an average of 2.0 or more vinyl groups per molecule. At least one selected from 0.01% by mass to 20% by mass with respect to the total mass of the fiber,
A nonwoven fabric containing
—Si(R 1 )HY 1 — (1)
(In formula (1), R 1 represents a hydrogen atom, a halogen atom or a hydrocarbon group, Y 1 represents O, S or NR 30 , and R 30 represents a hydrogen atom or a hydrocarbon group.)
The nonwoven fabric according to claim 1, wherein the thermoplastic resin contains at least one selected from the group consisting of polyolefin, polyamide and polyester.
The nonwoven fabric according to claim 1, wherein the thermoplastic resin contains polypropylene.
The nonwoven fabric according to any one of claims 1 to 3, wherein the vinyl group-containing compound has a structure represented by the following formula (4).
A-CH=CH 2 (4)
(In formula (4), A represents a polymer chain containing a structure derived from an α-olefin having 2 to 50 carbon atoms.)
The nonwoven fabric according to claim 4, wherein said A is an ethylene homopolymer chain.
The nonwoven fabric according to any one of claims 1 to 5, wherein the fibers have an average fiber diameter of 4.0 µm or less.
The nonwoven fabric according to any one of claims 1 to 6, which includes a meltblown nonwoven fabric.
A nonwoven fabric layer A, which is the nonwoven fabric according to any one of claims 1 to 7;
A nonwoven fabric laminate comprising a layer B other than the nonwoven fabric layer A.
The nonwoven laminate according to claim 8, wherein said layer B comprises a spunbond nonwoven layer.
A nonwoven fabric layer A that is the nonwoven fabric according to any one of claims 1 to 7, a layer B that is other than the nonwoven fabric layer A, and a layer C that is other than the nonwoven fabric layer A, and the layer 9. The nonwoven laminate of claim 8, wherein B, said nonwoven layer A and said layer C are arranged in order.
The nonwoven fabric laminate according to claim 10, wherein at least one of said layer B and said layer C comprises a spunbond nonwoven layer.
A filter comprising the nonwoven fabric according to any one of claims 1 to 7 or the nonwoven fabric laminate according to any one of claims 8 to 11.
A liquid shielding article comprising the nonwoven fabric according to any one of claims 1 to 7 or the nonwoven fabric laminate according to any one of claims 8 to 11.