JP6782118B2 - Porous materials, filters, filter media, filter devices, methods for purifying and producing acrylic polymers, and methods for producing photosensitive resin compositions. - Google Patents

Description

The present invention relates to a porous body, a filter containing the porous body, a filter media and a filter device, a method for purifying and producing an acrylic polymer using the porous body, and a method for producing a photosensitive resin composition. ..

As the demand for high performance, high functionality, and low power consumption increases in semiconductor devices, the circuit pattern is becoming finer, and the resist pattern obtained by pattern formation using the photosensitive resin composition is Defects may occur in the shape of the pattern surface due to residues during development and the like. Defects in the surface shape of such a pattern cause a decrease in the yield of the semiconductor element.

Conventionally, the above-mentioned defects are often caused by impurities contained in a resist composition or the like used for manufacturing a semiconductor device, and in order to reduce impurities, the resist composition, a resin material or the like used in the manufacturing process of a semiconductor device has been used. It has been cleaned by a filter device or the like. The filter device usually includes a filter medium using a porous membrane.

As the porous film, it is desirable that the porous film can remove even minute substances such as nano-particles. Nylon, polyethylene, polypropylene, PTFE, etc. are generally used as a filter membrane capable of removing impurities from resist compositions, resin materials, etc. used for applications such as semiconductor devices. For example, a filter membrane such as nylon is used. It is known that organic impurities are also removed by the method (for example, Patent Document 1).

Japanese Patent No. 4637476

However, according to the present inventor, when a resin for forming a resist film contains a high molecular weight substance (for example, a molecular weight of 30,000 or more) in its molecular weight distribution, if a resist film is formed, a residue is likely to be generated after development. It has been found that defects are likely to occur in the resist pattern.
Conventionally, there has been no porous film capable of effectively reducing the high molecular weight substance that causes such defects in the resin used in the semiconductor manufacturing process.

The present invention has been made in view of the above circumstances, and provides a porous body that reduces a high molecular weight substance (for example, Mw 30,000 or more) that can cause a defect in a resist pattern in a resin used in a semiconductor manufacturing process. With the goal.
Another object of the present invention is to provide a filter, a filter medium or a filter device containing the above-mentioned porous material.
Another object of the present invention is to provide a method for purifying or producing an acrylic polymer using the above-mentioned porous body, filter, filter media or filter device.
Another object of the present invention is to provide a method for producing a photosensitive resin composition containing the acrylic polymer.

The present inventor has insufficient ability to remove high molecular weight substances in a resin with a conventional porous membrane, but by using a porous body having an average pore diameter of 15 nm or less by the BET method, the high molecular weight in the resin We have found that the body can be effectively removed, and have completed the present invention. That is, the present invention is as follows.

The first aspect of the present invention is a porous body having an average pore diameter of 15 nm or less according to the BET method.

A second aspect of the present invention is a filter, filter media, or filter device containing a porous material according to the first aspect of the present invention.

In the third aspect of the present invention, the liquid containing the acrylic polymer is filtered by the porous body according to the first aspect of the present invention or the filter, filter media or filter device according to the second aspect of the present invention. It is a method for purifying an acrylic polymer, including the above.

A fourth aspect of the present invention is a method for producing an acrylic polymer, which uses the method for purifying an acrylic polymer according to the third aspect of the present invention.
A fifth aspect of the present invention is a method for producing a photosensitive resin composition containing an acrylic polymer.
Production of a photosensitive resin composition, wherein the acrylic polymer is an acrylic polymer purified by the purification method according to the third aspect of the present invention or an acrylic polymer produced by the production method according to the fourth aspect of the present invention. The method.

The porous body of the present invention can reduce high molecular weight substances (for example, molecules having a molecular weight of 30,000 or more in the molecular weight distribution) that can cause defects in the resist pattern in the resin used in the semiconductor manufacturing process.
Further, according to the present invention, it is possible to provide a filter, a filter medium or a filter device containing the above-mentioned porous material.
Further, according to the present invention, it is possible to provide a method for purifying or producing an acrylic polymer using the above-mentioned porous body, filter, filter media or filter device.
Further, according to the present invention, it is possible to provide a method for producing a photosensitive resin composition containing the acrylic polymer.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and can be carried out with appropriate modifications within the scope of the object of the present invention. ..
In the present specification, the description of "P and / or Q" such as "polyimide and / or polyamide-imide", and for example, "carboxy group, salt-type carboxy group and / or -NH-bond" and the like. As described above, the description of "P, Q and / or R" is "at least one selected from the group consisting of P and Q" and "at least one selected from the group consisting of P, Q and R", respectively. And other descriptions using "and / or" are also applicable. Here, P, Q and R are arbitrary terms.

<Porous medium with an average pore diameter of 15 nm or less by the BET method>
The porous body according to the first aspect has an average pore diameter of 15 nm or less according to the BET method. The average pore diameter by the BET method is preferably 12 nm or less, and more preferably the average pore diameter by the BET method is 10 nm or less.
The lower limit of the average pore diameter by the BET method is not particularly limited, but is preferably 1 nm or more, more preferably 2 nm or more, and further preferably 3 nm or more.

A porous body having an average pore size according to the BET method within the above range uses a high molecular weight body (for example, a molecule having a molecular weight of 30,000 or more in the molecular weight distribution) that can cause defects in the resist pattern in a resin used in a semiconductor manufacturing process. It can be effectively reduced. It is presumed that this is because the average pore size according to the BET method is within the above range, so that it is possible to provide holes such as communication holes having a pore size suitable for sieving to remove high molecular weight substances.
The reason why the above-mentioned defects occur is that the high molecular weight bodies easily aggregate in the liquid over time to form pseudo particles, and the high molecular weight bodies tend to form pseudo crosslinks with each other. Is presuming.
Further, the present inventor has found that the conventional film made of nylon has insufficient ability to remove the high molecular weight substance from the resin for forming the resist film.
In the present specification, the mass average molecular weight (Mw) is a measurement value obtained by gel permeation chromatography (GPC) in terms of polystyrene.
Since the porous body according to the first aspect can effectively remove such a high molecular weight body, the above-mentioned defects can be suppressed.
The porous body according to the first aspect preferably has communication holes. The hole diameter of the communication hole is the diameter of the communication hole.
The porous body according to the first aspect preferably contains communication holes having an average pore diameter of 15 nm or less according to the BET method.

Here, the BET method measures the adsorption isotherm by adsorbing and desorbing an adsorbed molecule (for example, nitrogen) to a porous body, and analyzes the measured data based on the BET formula represented by the formula (1). It is a method, and the specific surface area A and the total pore volume V can be calculated based on this method, and further, the average pore diameter is calculated from the formula [4V / A] based on the obtained specific surface area A and the total pore volume V. Can be calculated.
Specifically, first, the adsorption isotherm is obtained by adsorbing and desorbing adsorbed molecules on the porous body. Then, [P / {V _a (P ₀ −P)}] is calculated from the obtained adsorption isotherm based on the following equation (1), and plotted against the equilibrium relative pressure (P / P ₀ ). Then, this plot is regarded as a straight line, and the slope s (= [(C-1) / ( _Vm・ C)]) and the intercept i (= [1 / ( _Vm・ C)]) are based on the least squares method. Is calculated. Then, V _m and C are calculated from the obtained slopes s and intercept i based on the formulas (2-1) and (2-2). Further, the specific surface area A can be calculated from V _m based on the formula (3).
Further, the adsorption data of the obtained adsorption isotherm is linearly interpolated to obtain the adsorption amount at the relative pressure set by the pore volume calculation relative pressure. The total pore volume V can be calculated from this adsorption amount.
This BET method is a measurement method based on JIS R 1626-1996 "Measurement method of specific surface area by gas adsorption BET method of fine ceramic powder".
The measuring device by the BET method is not particularly limited, and examples thereof include Micromeritics (manufactured by Shimadzu Corporation).

[P / {V _a (P ₀ −P)}]
= [1 / ( _Vm・ C)] + [(C-1) / ( _Vm・ C)] (P / P ₀ ) (1)
V _m = 1 / (s + i) (2-1)
C = (s / i) + 1 (2-2)
_{A = (V m · L ·} σ) / 22414 (3)

However,
V _a : Adsorption amount V _m : Adsorption amount of monolayer P: Pressure at equilibrium of adsorbed molecule P ₀ : Saturated vapor pressure of adsorbed molecule L: Avocadro number σ: Adsorption cross-sectional area of adsorbed molecule.

In the porous body according to the first aspect, a communication hole having an opening on the outer surface of the porous body communicates with the inside of the porous body and opens on the outer surface on the opposite side (back side) of the porous body. It is preferable to have a communication hole so as to secure a flow path of the fluid through which the porous body passes. The fact that the porous body according to the first aspect has such communication holes can be expressed by, for example, the Garley air permeability, and the Garley air permeability can be, for example, 10 to 1000 seconds.

The garley air permeability of the porous body according to the first aspect can be, for example, 1000 seconds or less, preferably 600 seconds or less, more preferably 500 seconds or less, and most preferably 300 seconds or less. Since the lower the value, the lower the lower limit is not particularly set, but 10 seconds or more is preferable from the viewpoint of efficiently purifying the acrylic polymer while maintaining the flow velocity of the fluid passing through the porous body according to the first aspect to some extent. More preferably, 30 seconds or longer. When the Garley air permeability is 1000 seconds or less, the degree of porosity is sufficiently high, so that the effect of purifying the acrylic polymer can be enhanced.

The porous body according to the first aspect preferably has a porosity of 50 to 90% by mass, more preferably 55 to 80% by mass, and 60 to 80% from the viewpoint of reducing the pore diameter of the communication holes. It is more preferably by mass%.
The porosity can be calculated, for example, as the porosity (mass%) of the mass of the fine particles with respect to the total mass of the resin and the fine particles used in the production of the porous body.
The film thickness of the porous body according to the first aspect is not particularly limited, but is preferably 5 μm or more and 500 μm or less, more preferably 10 μm or more and 100 μm or less, and particularly preferably 10 μm or more and 40 μm or less. .. The above film thickness can be obtained by measuring and averaging the thicknesses of a plurality of locations with, for example, a micrometer.
The porous body according to the first aspect may be any of polyimide and / or polyamide-imide porous film, polyether sulfone (PES) porous film, polyethylene porous film, etc., as long as the average pore size by the BET method is 15 nm or less. Although it may contain a porous film, it preferably contains a polyimide and / or polyamide-imide porous film.
Further, the porous body according to the first aspect may be composed of only a polyimide and / or a polyamide-imide porous film, but the polyimide and / or the polyamide-imide porous film and another porous film are overlapped with each other. May be used together.
As the porous body according to the first aspect, it is preferable to use a plurality of porous films of the same type or a plurality of types in layers, and a plurality of (for example, two) porous polyimide and / or polyamideimide porous films are used in layers. Is more preferable.

[Polyimide and / or Polyamideimide Porous Membrane]
The polyimide and / or polyamide-imide porous membrane preferably has communication holes. The communication holes may be formed by individual holes (hereinafter, may be simply abbreviated as "pores") that impart porosity to the polyimide and / or polyamide-imide porous film. The hole is preferably a hole having a curved surface on the inner surface described later, and more preferably a substantially spherical hole described later. In a polyimide and / or polyamide-imide porous membrane, a portion in which such individual pores are formed adjacent to each other becomes a communication hole, and the pores have a structure in which they communicate with each other, and usually, a plurality of such holes are connected to each other. As a whole, it is preferable to form a flow path of the liquid to be purified. The "flow path" is usually formed by a series of individual "holes" and / or "communication holes". It can be said that the individual pores are pores formed by removing the individual fine particles existing in the polyimide resin-fine particle composite film in the subsequent step in the method for producing the polyimide resin porous film described later. Further, in the communication hole, the fine particles are removed in a later step from the portion where the individual fine particles existing in the polyimide resin-fine particle composite film are in contact with each other in the method for producing a polyimide resin porous film described later. It can also be said that they are adjacent individual holes formed by.

The polyimide and / or polyamide-imide porous film preferably contains communication holes having an average pore diameter of 15 nm or less according to the BET method. Since one communication hole is usually formed from two adjacent particles according to the manufacturing method described later, the diameter is defined as, for example, the direction in which two individual holes constituting the communication hole are continuous. , May be the diameter in the direction perpendicular to the longitudinal direction. The pore diameter of the communication holes is such that the distribution of the pore diameters of the individual holes that impart porosity to the polyimide and / or polyamide-imide porous film is broader, the communication holes are formed so that the individual holes are adjacent to each other. The diameter of itself tends to be smaller.

When the polyimide and / or polyamide-imide porous membrane has communication holes, passing the fluid through the porous membrane allows the fluid to pass through the inside of the porous membrane. It is preferable that the polyimide and / or polyamide-imide porous film has a flow path in which individual pores having curved surfaces on the inner surface are continuous by communication holes.

As described above, the polyimide and / or polyamide-imide porous membrane is preferably a porous membrane containing pores having curved surfaces on the inner surface, and many (preferably substantially all) of the pores in the porous membrane are present. It is more preferable that it is formed of a curved surface. As used herein, the term "having a curved surface on the inner surface" of a hole means that at least the inner surface of the hole that provides porosity has a curved surface on at least a part of the inner surface.

It is preferable that at least substantially all of the pores in the porous membrane in the present invention are curved surfaces, and such pores are hereinafter referred to as "substantially spherical pores". As used herein, the term "substantially spherical hole" means a hole whose inner surface forms a substantially spherical space. It can be said that the substantially spherical pores are preferably pores formed when the fine particles used in the method for producing a polyimide resin porous film described later are substantially spherical. In the present specification, the term "substantially spherical" is a concept including a true sphere, but is not necessarily limited to a true sphere, and includes a substantially spherical one. In the present specification, "substantially spherical" means that the sphericity defined by the sphericity expressed by the value obtained by dividing the major axis of the particle by the minor axis is within 1 ± 0.3. means. The substantially spherical pores of the polyimide and / or the polyamide-imide porous film in the present invention preferably have a sphericity of 1 ± 0.1 or less, and more preferably 1 ± 0.05 or less.

Since the pores in the porous membrane have a curved surface on the inner surface, when the fluid is passed through the polyimide and / or the polyamide-imide porous membrane, the fluid is sufficiently distributed inside the pores in the porous membrane, and the inner surface of the pores is sufficient. It is possible that they can come into contact with each other, and in some cases, convection may occur along the curved surface of the inner surface. The substantially spherical hole may further have a recess on the inner surface. The recess may be formed, for example, by a hole having an opening on the inner surface of the substantially spherical hole and having a hole diameter smaller than that of the substantially spherical hole.

The polyimide and / or polyamide-imide porous film preferably contains a structure in which substantially spherical pores having an average spherical diameter of 2000 nm or less communicate with each other. The average spherical diameter of such substantially spherical holes is preferably 600 nm or less, and more preferably 500 nm or less. When the average sphere is in the range of 600 nm to 2000 nm, the particle size distribution index (d25 / 75) of the fine particles described later is preferably 1.6 to 5, and more preferably 2 to 4. When the average sphere is 600 nm or less, the particle size distribution index (d25 / 75) of the fine particles described later is preferably 1 to 5, and more preferably 1.1 to 4. The average sphere diameter of the substantially spherical holes is a value obtained by obtaining the average amount of change in the size of the communicating holes with a porometer for the one subjected to the chemical etching treatment described later, and obtaining the actual average sphere diameter of the substantially spherical holes from the value. However, in the case of polyamide-imide which is not subjected to the above-mentioned chemical etching, the average particle size of the fine particles used for producing the porous film can be set to the average spherical diameter of substantially spherical pores.

The polyimide and / or polyamide-imide porous film contains a resin and may be substantially composed of only the resin, and specifically, 95% by mass or more, preferably 98% by mass or more. More preferably, 99% by mass or more is a resin. As the resin contained in the polyimide and / or polyamide-imide porous film, polyimide and / or polyamide-imide is preferable, a resin containing polyimide is more preferable, and only polyimide may be used. In the present specification, polyimide and / or polyamide-imide may be referred to as "polyimide-based resin".

The polyimide and / or polyamide-imide contained in the polyimide and / or polyamide-imide porous membrane (hereinafter, may be abbreviated as "polyimide-based resin porous membrane" or "porous membrane") includes a carboxy group and a salt. It may have at least one selected from the group consisting of a type carboxy group and a -NH- bond. The polyimide and / or polyamide-imide may have a carboxy group, a salt-type carboxy group and / or a -NH- bond other than the main chain end of the polyimide and / or polyamide-imide.

As used herein, the term "salt-type carboxy group" means a group in which a hydrogen atom in a carboxy group is replaced with a cation component. In the present specification, the “cation component” may be a cation itself in a completely ionized state, or a cation component in a state in which it is ionically bonded to −COO ⁻ and is virtually uncharged. It may be a cation component having a partial charge which is an intermediate state between the two. When the "cation component" is an M ion component composed of an n-valent metal M, the cation itself is represented by M ^{n +,} and the cation component is represented by "M" in "-COOM _{1 / n} ". It is an element to be done.

In the present invention, the state of the "salt-type carboxy group" and the "cationic component" is not particularly limited, and usually, whether it is in an environment in which polyimide and / or polyamide-imide is present, for example, in an aqueous solution. It may depend on whether it is in an organic solvent, dry, etc. If cationic component is a sodium ion component, for example, if an aqueous solution, -COO ^- and Na ⁺ and may have dissociated, if the or dry organic solvent, - It is highly possible that COONa has not dissociated.

Specifically, the polyimide and / or polyamide-imide in the present invention may have at least one selected from the group consisting of the structural units represented by the following formulas (3) to (6). In the case of polyimide, it may have a structural unit represented by the following formulas (3) and / or (4), and in the case of polyamide-imide, it may be represented by the following formulas (5) and / or (6). It may have a structural unit.

In the above formula, X is the same or different and is a hydrogen atom or a cation component. Ar is an aryl group, and Ar in which a carbonyl group is bonded in each of the repeating unit represented by the formula (1) constituting the polyamic acid described later or the repeating unit represented by the formula (2) constituting the aromatic polyimide. It may be the same as the aryl group represented by. Y is a divalent residue excluding the amino group of the diamine compound, and is a repeating unit represented by the formula (1) constituting the polyamic acid described later or a repeating unit represented by the formula (2) constituting the aromatic polyimide. It may be the same as the aryl group represented by Ar to which N is bonded in each unit.

In the case of polyimide and / or polyamide-imide in the present invention, a part of the imide bond ([-C (= O)] ₂ -N-) of general polyimide and / or polyamide-imide is opened, and in the case of polyimide. It may have a structural unit represented by the above formulas (3) and / or (4), and in the case of polyamide-imide, it may have a structural unit represented by the above formula (5). Also in the polyamide-imide, a part of the imide bond originally possessed by the polyamide-imide may be ring-opened to have the structural unit represented by the above (5).

The polyimide and / or polyamide-imide in the present invention is a polyimide having at least one selected from the group consisting of a carboxy group, a salt-type carboxy group and a -NH- bond by opening a part of the imide bond. Alternatively, it may be a polyamide-imide porous film.

(Manufacturing method of polyimide resin porous membrane)
The method for producing a polyimide-based resin porous film is an unfired composite film forming step of forming an unfired composite film using a varnish containing a resin composed of polyamic acid and / or polyimide, fine particles, and a solvent. A firing step of firing the unfired composite film to obtain a polyimide resin-fine particle composite film and a fine particle removing step of removing fine particles from the polyimide-fine particle composite film are included in the above order.

(Manufacturing of varnish)
In the production of varnish, an organic solvent in which fine particles are dispersed in advance and polyamic acid, polyimide or polyamide-imide are mixed at an arbitrary ratio, or tetracarboxylic acid dianhydride and diamine are polymerized in an organic solvent in which fine particles are dispersed in advance. It can be produced by using a polyamic acid or further imidizing it into a polyimide, and it is preferable that the viscosity is finally set to 300 to 2000 cP (0.3 to 2 Pa · s). If the viscosity of the varnish is within this range, it is possible to form a uniform film.

The varnish has a fine particle / polyimide resin ratio of 1 to 4 (mass ratio) when the fine particles are fired (dried if firing is optional) to form a polyimide resin-fine particle composite film. The resin fine particles can be mixed with polyamic acid or polyimide or polyamide-imide, and the ratio of the fine particles / polyimide resin is preferably 1.1 to 3.5 (mass ratio). Further, when the polyimide resin-fine particle composite film is formed, the fine particles may be mixed with polyamic acid or polyimide or polyamide-imide so that the volume ratio of the fine particles / polyimide resin is 1.1 to 5. Further, it is more preferable that the ratio of the fine particles / polyimide resin is 1.1 to 4.5 (volume ratio). If the mass ratio or volume ratio of the fine particle / polyimide resin is at least the lower limit value, pores with an appropriate density can be obtained as a porous film, and if it is at least the upper limit value, the viscosity increases, cracks in the film, etc. It is possible to form a stable film without causing the problem of. In addition, in this specification, a volume% and a volume ratio are values at 25 ° C.

(Fine particles)
The material of the fine particles can be used without particular limitation as long as it is insoluble in the organic solvent used for the varnish and can be selectively removed after the film formation. For example, inorganic materials include metal oxides such as silica (silicon dioxide), titanium oxide, alumina (Al ₂ O ₃ ) and calcium carbonate, and organic materials include high molecular weight olefins (polypropylene, polyethylene, etc.), polystyrene and acrylic. Examples thereof include organic polymer fine particles (resin fine particles) such as based resins (methyl methacrylate, isobutyl methacrylate, polymethyl methacrylate (PMMA), etc.), epoxy resins, cellulose, polyvinyl alcohol, polyvinyl butyral, polyester, polyether, polyethylene, etc. ..

Specifically, as the fine particles, for example, colloidal silica, particularly monodisperse spherical silica particles, is preferable because uniform pores can be formed.

Further, the fine particles preferably have a high sphericity and a small particle size distribution index. The fine particles having these conditions have excellent dispersibility in the varnish and can be used in a state where they do not aggregate with each other.
As the particle size (average diameter) of the fine particles used, for example, those having a particle size of 5 nm to 2000 nm, preferably 10 nm to 600 nm can be used. When the particle size (average diameter) of the fine particles is in the range of 600 nm to 2000 nm, the particle size distribution index (d25 / 75) is preferably 1.6 to 5, and more preferably 2 to 4. When the particle size (average diameter) of the fine particles is 600 nm or less, the particle size distribution index (d25 / 75) of the fine particles described later is preferably 1 to 5, and more preferably 1.1 to 4. Note that d25 and d75 are values of particle diameters in which the cumulative frequencies of the particle size distribution are 25% and 75%, respectively, and in the present specification, d25 is the one having the larger particle size.
The fine particles may be used alone or in combination of two or more.

Further, in the production method described later, when the unfired composite film is formed as a two-layer unfired composite film, the fine particles (B1) used for the first varnish and the fine particles (B2) used for the second varnish are the same. Those may be used, or different ones may be used. In order to make the pores on the side in contact with the substrate more dense, it is preferable that the fine particles of (B1) have a smaller or the same particle size distribution index than the fine particles of (B2). Alternatively, the fine particles of (B1) preferably have a smaller or the same sphericity ratio than the fine particles of (B2). Further, the fine particles of (B1) preferably have a smaller particle size (average diameter) than the fine particles of (B2).

A dispersant may be further added together with the fine particles for the purpose of uniformly dispersing the fine particles in the varnish. By adding the dispersant, the polyamic acid, polyimide or polyamide-imide and the fine particles can be mixed more uniformly, and further, the fine particles in the molded or formed precursor film can be uniformly distributed. As a result, the front and back surfaces of the porous resin porous membrane are efficiently made so as to provide dense openings on the surface of the finally obtained polyimide-based resin porous membrane and improve the air permeability of the polyimide resin porous membrane. It is possible to form a communication hole that allows good communication.

As the dispersant, known ones can be used without particular limitation. For example, palm fatty acid salt, castor sulfate oil salt, lauryl sulfate salt, polyoxyalkylene allylphenyl ether sulfate salt, alkylbenzene sulfonic acid, alkylbenzene sulfonate, alkyldiphenyl ether disulfonate, alkylnaphthalene sulfonate, dialkyl sulfosucci Anionic surfactants such as nate salts, isopropyl phosphates, polyoxyethylene alkyl ether phosphate salts, polyoxyethylene allylphenyl ether phosphate salts; oleylamine acetate, laurylpyridinium chloride, cetylpyridinium chloride, lauryltrimethylammonium chloride, stearyltrimethylammonium chloride. , Behenyltrimethylammonium chloride, didecyldimethylammonium chloride and other cationic surfactants; palm alkyldimethylamine oxide, fatty acid amide propyldimethylamine oxide, alkylpolyaminoethylglycine hydrochloride, amide betaine type activator, alanine type activator, lauryl Amphoteric surfactants such as iminodipropionic acid; polyoxyethylene octyl ether, polyoxyethylene decyl ether, polyoxyethylene lauryl ether, polyoxyethylene laurylamine, polyoxyethylene oleylamine, polyoxyethylene polystyrylphenyl ether, polyoxy Nonionic surfactant of polyoxyalkylene primary alkyl ether or polyoxyalkylene secondary alkyl ether such as alkylene polystyrylphenyl ether, polyoxyethylene dilaurate, polyoxyethylene laurate, polyoxyethylene acidified castor oil, polyoxyethylene curing Other polyoxyalkylene-based nonionic surfactants such as castor oil, sorbitan lauric acid ester, polyoxyethylene sorbitan lauric acid ester, fatty acid diethanolamide; fatty acid alkyl esters such as octyl stearate, trimethylol propanthridecanoate; poly Examples thereof include, but are not limited to, polyether polyols such as oxyalkylene butyl ether, polyoxyalkylene oleyl ether, and trimethyl propanthris (polyoxyalkylene) ether. Further, the above-mentioned dispersant may be used as a mixture of two or more kinds.

(Polyamic acid)
The polyamic acid obtained by polymerizing an arbitrary tetracarboxylic dianhydride with a diamine can be used without particular limitation. The amount of the tetracarboxylic dianhydride and the diamine used is not particularly limited, but it is preferable to use 0.50 to 1.50 mol of the diamine per 1 mol of the tetracarboxylic dianhydride, and 0.60 to 1. It is more preferable to use 30 mol, and it is particularly preferable to use 0.70 to 1.20 mol.

The tetracarboxylic dianhydride can be appropriately selected from the tetracarboxylic dianhydrides conventionally used as synthetic raw materials for polyamic acids. The tetracarboxylic dianhydride may be an aromatic tetracarboxylic dianhydride or an aliphatic tetracarboxylic dianhydride, but from the viewpoint of the heat resistance of the obtained polyimide resin, the aromatic dianite It is preferable to use a carboxylic acid dianhydride. Two or more types of tetracarboxylic dianhydride may be used in combination.

Preferable specific examples of the aromatic tetracarboxylic acid dianhydride include pyromellitic acid dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, and bis (2,3-dicarboxyphenyl). Phenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride, 2,3,3', 4'- Biphenyltetracarboxylic acid dianhydride, 2,2,6,6-biphenyltetracarboxylic acid dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2) , 3-Dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2 -Bis (2,3-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, 2,2', 3,3'-benzophenone tetracarboxylic acid dianhydride, 4,4 -(P-Phenylenedoxy) diphthalic hydride, 4,4- (m-Phenylenedoxy) diphthalic hydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4 5,8-Naphthalenetetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,2,3,4-benzenetetracarboxylic acid dianhydride, 3,4,9, 10-Perylenetetracarboxylic hydride, 2,3,6,7-anthracenetetracarboxylic hydride, 1,2,7,8-phenanthrenetetracarboxylic hydride, 9,9-bisphthalic anhydride Examples thereof include fluorene, 3,3', 4,4'-diphenylsulfone tetracarboxylic dianhydride and the like. Examples of the aliphatic tetracarboxylic dianhydride include ethylenetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, 1, Examples thereof include 2,4,5-cyclohexanetetracarboxylic dianhydride and 1,2,3,4-cyclohexanetetracarboxylic dianhydride. Among these, 3,3', 4,4'-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride are preferable from the viewpoint of price, availability and the like. Further, these tetracarboxylic dianhydrides can be used alone or in combination of two or more.

The diamine can be appropriately selected from diamines conventionally used as a synthetic raw material for polyamic acid. This diamine may be an aromatic diamine or an aliphatic diamine, but an aromatic diamine is preferable from the viewpoint of heat resistance of the obtained polyimide resin. Two or more kinds of these diamines may be used in combination.

Examples of the aromatic diamine include a diamino compound in which one phenyl group or about 2 to 10 phenyl groups are bonded. Specifically, phenylenediamine and its derivatives, diaminobiphenyl compounds and their derivatives, diaminodiphenyl compounds and their derivatives, diaminotriphenyl compounds and their derivatives, diaminonaphthalene and its derivatives, aminophenylaminoindane and its derivatives, diaminotetraphenyl. The compound and its derivative, the diaminohexaphenyl compound and its derivative, and the cardo-type fluorinamine derivative.

The phenylenediamine is m-phenylenediamine, p-phenylenediamine or the like, and the phenylenediamine derivative is a diamine to which an alkyl group such as a methyl group or an ethyl group is bonded, for example, 2,4-diaminotoluene or 2,4-triphenylene. Diamine and the like.

A diaminobiphenyl compound is a compound in which two aminophenyl groups are bonded to each other. For example, 4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl and the like.

A diaminodiphenyl compound is a compound in which two aminophenyl groups are bonded to each other via another group. The bond is an ether bond, a sulfonyl bond, a thioether bond, a bond by an alkylene or a derivative group thereof, an imino bond, an azo bond, a phosphine oxide bond, an amide bond, a ureylene bond and the like. The alkylene bond has about 1 to 6 carbon atoms, and the derivative group thereof is one in which one or more hydrogen atoms of the alkylene group are substituted with a halogen atom or the like.

Examples of diaminodiphenyl compounds include 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylketone , 3,4'-diaminodiphenylketone, 2,2-bis (p-aminophenyl) propane, 2,2'-bis (p-aminophenyl) hexafluoropropane, 4-methyl-2,4-bis ( p-aminophenyl) -1-pentene, 4-methyl-2,4-bis (p-aminophenyl) -2-penten, iminodianiline, 4-methyl-2,4-bis (p-aminophenyl) Pentan, bis (p-aminophenyl) phosphine oxide, 4,4'-diaminoazobenzene, 4,4'-diaminodiphenylurea, 4,4'-diaminodiphenylamide, 1,4-bis (4-aminophenoxy) benzene , 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) ) Phenyl] sulphon, bis [4- (3-aminophenoxy) phenyl] sulphon, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] ) Phenyl] Hexafluoropropane and the like.

Among these, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, and 4,4'-diaminodiphenyl ether are preferable from the viewpoint of price, availability, and the like.

The diaminotriphenyl compound is one in which two aminophenyl groups and one phenylene group are bonded via other groups, and the other groups are selected to be the same as those of the diaminodiphenyl compound. Examples of the diaminotriphenyl compound include 1,3-bis (m-aminophenoxy) benzene, 1,3-bis (p-aminophenoxy) benzene, 1,4-bis (p-aminophenoxy) benzene and the like. be able to.

Examples of diaminonaphthalene include 1,5-diaminonaphthalene and 2,6-diaminonaphthalene.

Examples of aminophenylaminoindanes include 5- or 6-amino-1- (p-aminophenyl) -1,3,3-trimethylindanes.

Examples of diaminotetraphenyl compounds are 4,4'-bis (p-aminophenoxy) biphenyl, 2,2'-bis [p- (p'-aminophenoxy) phenyl] propane, 2,2'-bis [ Examples thereof include p- (p'-aminophenoxy) biphenyl] propane, 2,2'-bis [p- (m-aminophenoxy) phenyl] benzophenone and the like.

Examples of the cardo-type fluorene amine derivative include 9,9-bisaniline fluorene and the like.

The aliphatic diamine is preferably one having about 2 to 15 carbon atoms, and specific examples thereof include pentamethylenediamine, hexamethylenediamine, and heptamethylenediamine.

In addition, the hydrogen atom of these diamines may be a compound substituted with at least one substituent selected from the group such as a halogen atom, a methyl group, a methoxy group, a cyano group, and a phenyl group.

The means for producing the polyamic acid used in the present invention is not particularly limited, and for example, a known method such as a method of reacting an acid or a diamine component in an organic solvent can be used.

The reaction of the tetracarboxylic dianhydride with the diamine is usually carried out in an organic solvent. The organic solvent used for the reaction between the tetracarboxylic dianhydride and the diamine is particularly capable of dissolving the tetracarboxylic dianhydride and the diamine and not reacting with the tetracarboxylic dianhydride and the diamine. Not limited. The organic solvent can be used alone or in combination of two or more.

Examples of organic solvents used in the reaction of tetracarboxylic acid dianhydride with diamine include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylformamide, N. , N-diethylformamide, N-methylcaprolactam, N, N, N', N'-tetramethylurea and other nitrogen-containing polar solvents; β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone , Gamma-caprolactone, ε-caprolactone and other lactone-based polar solvents; dimethylsulfoxide; acetonitrile; ethyl lactate, butyl lactate and other fatty acid esters; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane, tetrahydrofuran, methyl cellsolve acetate, ethyl cell solve Ethers such as acetate; phenolic solvents such as cresols can be mentioned. These organic solvents can be used alone or in combination of two or more. Of these, the combination of the nitrogen-containing polar solvent and the lactone-based polar solvent is preferable. The amount of the organic solvent used is not particularly limited, but it is desirable that the content of the polyamic acid produced is 5 to 50% by mass.

Among these organic solvents, due to the solubility of the polyamic acid produced, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylformamide, N, N- Nitrogen-containing polar solvents such as diethylformamide, N-methylcaprolactam, N, N, N', N'-tetramethylurea are preferable. Further, from the viewpoint of film forming property and the like, it may be a mixed solvent to which a lactone-based polar solvent such as γ-butyrolactone is added, and it is preferable that 1 to 20% by mass is added to the entire organic solvent, and 5 to 15% by mass is added. % Is more preferable.

The polymerization temperature is generally −10 to 120 ° C., preferably 5 to 30 ° C. The polymerization time varies depending on the composition of the raw material used, but is usually 3 to 24 Hr (hours). The intrinsic viscosity of the polyamic acid solution obtained under such conditions is preferably in the range of 1000 to 100,000 cP (centipores), and even more preferably in the range of 5,000 to 70,000 cP.

(Polyimide)
As the polyimide, any known soluble polyimide can be used as long as it is soluble in the organic solvent used for the varnish, regardless of its structure and molecular weight. Regarding polyimide, the side chain may have a condensable functional group such as a carboxy group or a functional group that promotes a crosslinking reaction or the like during firing.

Use of a monomer to introduce a flexible bent structure in the main chain to make a polyimide soluble in an organic solvent, such as ethirediamine, hexamethylenediamine, 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, Aliphatic diamines such as 4,4'-diaminodicyclohexylmethane; 2-methyl-1,4-phenylenediamine, o-trizine, m-trizine, 3,3'-dimethoxybenzidine, 4,4'-diaminobenzanilide, etc. Aromatic diamines; polyoxyalkylene diamines such as polyoxyethylene diamines, polyoxypropylene diamines, and polyoxybutylenediamines; polysiloxane diamines; 2,3,3', 4'-oxydiphthalic acid anhydrides, 3,4,3' , 4'-oxydiphthalic acid anhydride, 2,2-bis (4-hydroxyphenyl) propandibenzoate-3,3', 4,4'-tetracarboxylic acid dianhydride, etc. are effective. Also, the use of monomers having functional groups that improve solubility in organic solvents, such as 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 2-trifluoromethyl-1,4. -It is also effective to use a fluorinated diamine such as phenylenediamine. Further, in addition to the monomer for improving the solubility of the polyimide, the same monomer as described in the column of polyamic acid can be used in combination as long as the solubility is not impaired.

The means for producing the polyimide that can be dissolved in an organic solvent is not particularly limited, and for example, a known method such as a method of chemically imidizing or heat imidizing a polyamic acid and dissolving it in an organic solvent can be used. Examples of such a polyimide include an aliphatic polyimide (total aliphatic polyimide) and an aromatic polyimide, and an aromatic polyimide is preferable. The aromatic polyimide is a polyamic acid having a repeating unit represented by the formula (1) obtained by a thermal or chemical ring-closing reaction, or a polyimide having a repeating unit represented by the formula (2) dissolved in a solvent. Good. In the formula, Ar represents an aryl group.

(Polyamide-imide)
As the polyamide-imide, any known soluble polyamide-imide that can be dissolved in the organic solvent used for the varnish can be used without being limited in its structure and molecular weight. Regarding polyamide-imide, the side chain may have a condensable functional group such as a carboxy group or a functional group that promotes a crosslinking reaction or the like during firing.

Further, the polyamide-imide is obtained by imidizing a precursor polymer obtained by reacting an arbitrary trimellitic acid anhydride with diisocyanate or a reactive derivative of any trimellitic anhydride and a diamine. Can be used without particular limitation.

Examples of the above-mentioned optional trimellitic anhydride and acid or a reactive derivative thereof include trimellitic anhydride, trimellitic anhydride such as trimellitic anhydride, trimellitic anhydride, and trimellitic anhydride.

Examples of the above-mentioned arbitrary diisocyanate include metaphenylene diisocyanate, p-phenylenedi isocyanate, o-trizine diisocyanate, p-phenylenedi isocyanate, m-phenylenedi isocyanate, 4,4'-oxybis (phenylisocyanate), and 4,4'-diisocyanate. Diphenylmethane, bis [4- (4-isocyanate phenoxy) phenyl] sulfone, 2,2'-bis [4- (4-isocyanphenoxy) phenyl] propane, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate , 4,4'-Diphenylmethane diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, 3,3'-diethyldiphenyl-4,4'-diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 4,4' Examples thereof include −dicyclohexylmethane diisocyanate, m-xylene diisocyanate, p-xylene diisocyanate, and naphthalene diisocyanate.

Examples of the optional diamine include those similar to those exemplified in the above description of the polyamic acid.

(solvent)
The solvent used for the varnish is not particularly limited as long as it can dissolve polyamic acid and / or polyimide resin and does not dissolve fine particles, and is used for the reaction between tetracarboxylic dianhydride and diamine. Examples thereof include those exemplified as a solvent. The solvent may be used alone or in combination of two or more.

The solvent content of all the components in the varnish is preferably 50 to 95% by mass, more preferably 60 to 85% by mass. The solid content concentration in the varnish is preferably 5 to 50% by mass, more preferably 15 to 40% by mass.

In addition to the above components, antistatic agents, flame retardants, chemical imidizing agents, condensing agents, mold release agents, surfaces, etc. for the purpose of antistatic, flame retardant imparting, low temperature firing, mold release, coatability, etc. Known components such as an adjusting agent can be appropriately contained.

(Manufacturing of unfired composite film (unfired composite film film forming process))
In the case of forming an unfired composite film containing a polyamic acid or a polyimide resin and fine particles, the above varnish is applied onto a substrate and the temperature is 0 to 120 ° C. (preferably 0 to 0) under normal pressure or vacuum. 100 ° C.), more preferably 60 to 95 ° C. (more preferably 65 to 90 ° C.) under normal pressure. The coating film thickness is, for example, 1 to 500 μm, preferably 5 to 50 μm. A release layer may be provided on the substrate as needed. Further, in the production of the unfired composite film, before the production (firing step) of the polyimide resin-fine particle composite film described later, a dipping step in a solvent containing water, a pressing step, and a drying step after the dipping step are performed. It may be provided as an arbitrary process.

The release layer can be produced by applying a release agent on a substrate and drying or baking. As the release agent used here, known release agents such as alkyl phosphate ammonium salt type, fluorine type and silicone can be used without particular limitation. When the unfired composite film containing the dried polyamic acid or polyimide resin and fine particles is peeled off from the substrate, a small amount of release agent remains on the peeled surface of the unfired composite film. Since the remaining mold release agent may affect the wettability of the surface of the polyimide resin porous film and the mixing of impurities, it is preferable to remove it.

Therefore, it is preferable to wash the unfired composite film peeled from the substrate with an organic solvent or the like. The cleaning method can be selected from known methods such as a method of immersing the unfired composite film in the cleaning liquid and then taking it out, and a method of shower cleaning. Further, in order to dry the unfired composite film after washing, known methods such as air-drying the unfired composite film after washing at room temperature and heating to an appropriate set temperature in a constant temperature bath are not limited. Applicable. For example, a method of fixing the end portion of the unfired composite film to a SUS mold or the like to prevent deformation can be adopted.

On the other hand, when the substrate is used as it is without providing the release layer for the film formation of the unfired composite film, the step of forming the release layer and the step of cleaning the unfired composite film can be omitted.

When forming as a two-layer unfired composite film, first, the first varnish is applied as it is on a substrate such as a glass substrate, and the temperature is 0 to 120 ° C. (preferably 0 to 90) under normal pressure or vacuum. ° C.), more preferably at normal pressures of 10 to 100 ° C. (more preferably 10 to 90 ° C.) to form a first unfired composite film having a film thickness of 1 to 5 μm.

Subsequently, the second varnish was applied onto the formed first unfired composite film, and similarly, 0 to 80 ° C. (preferably 0 to 50 ° C.), more preferably 10 to 80 ° C. (normal pressure). More preferably, it is dried at 10 to 30 ° C.) to form a second unfired composite film having a thickness of 5 to 50 μm to obtain a two-layer unfired composite film.

(Manufacture of polyimide resin-fine particle composite film (firing process))
The unfired composite film after drying (or a two-layer unfired composite film, the same applies hereinafter) is post-treated (baked) by heating to form a composite film (polyimide resin-fine particle composite film) composed of a polyimide resin and fine particles. ) Can be. When the varnish contains polyamic acid, it is preferable to complete imidization in the firing step. The firing step is an arbitrary step. In particular, when polyimide or polyamide-imide is used for the varnish, the firing step may not be performed.

The firing temperature varies depending on the structure of the polyamic acid or polyimide resin contained in the unfired composite film and the presence or absence of a condensing agent, but is preferably 120 to 400 ° C, more preferably 150 to 375 ° C.

In order to perform firing, it is not always necessary to clearly separate the drying process from the process. For example, when firing at 375 ° C, the temperature is raised from room temperature to 375 ° C in 3 hours and then held at 375 ° C for 20 minutes. Use a stepwise drying-heat imidization method, such as a method of sintering from room temperature in steps of 50 ° C. to 375 ° C. (holding for 20 minutes in each step), and finally holding at 375 ° C. for 20 minutes. You can also. At that time, a method of fixing the end portion of the unfired composite film to a mold made of SUS or the like to prevent deformation may be adopted.

In the case of a film, for example, the thickness of the completed polyimide resin-fine particle composite film can be obtained by measuring the thicknesses of a plurality of locations with a micrometer or the like and averaging them. What kind of average thickness is preferable depends on the use of the polyimide resin-fine particle composite membrane or the polyimide resin porous membrane, but for example, when used as a separating material, an adsorbent, etc., a thinner one is preferable. For example, it may be 1 μm or more, preferably 5 to 500 μm, and more preferably 8 to 100 μm.

(Particle removal process (polyimide resin-microparticle composite film porosity))
By selecting and removing fine particles from the polyimide resin-fine particle composite film by an appropriate method, a polyimide resin porous film having fine pores can be produced with good reproducibility. For example, when silica is used as the fine particles, the polyimide resin-fine particle composite film can be made porous by dissolving and removing the silica with low-concentration hydrogen fluoride water (HF) or the like. When the fine particles are resin fine particles, the resin fine particles can be removed by decomposing the resin fine particles by heating to a temperature higher than the thermal decomposition temperature of the resin fine particles and lower than the thermal decomposition temperature of the polyimide resin as described above.

(Polyimide resin removal process)
The method for producing the polyimide resin porous film is to remove at least a part of the polyimide resin portion of the polyimide resin-fine particle composite film before the fine particle removing step, or at least one of the polyimide resins after the fine particle removing step. A polyimide resin removing step of removing the portion may be included. By removing at least a part of the polyimide resin portion of the polyimide resin-fine particle composite film before the fine particle removing step, when the fine particles are removed and pores are formed in the subsequent fine particle removing step, the polyimide resin is described. It is possible to improve the pore-opening rate of the polyimide-based resin porous film of the final product as compared with the one in which at least a part of the portion is not removed. Further, by removing at least a part of the polyimide-based resin porous film after the fine particle removal step, the polyimide-based resin porous film of the final product is compared with the one in which at least a part of the polyimide-based resin porous film is not removed. It is possible to improve the opening rate of.

The step of removing at least a part of the polyimide-based resin portion or the step of removing at least a part of the polyimide-based resin porous film is a usual chemical etching method or a physical removal method, or a combination thereof. It can be done by the method.

Examples of the chemical etching method include treatment with a chemical etching solution such as an inorganic alkaline solution or an organic alkaline solution. Inorganic alkaline solutions are preferred. Examples of the inorganic alkaline solution include a hydrazine solution containing hydrazine hydrate and ethylenediamine, a solution of an alkali metal hydroxide such as potassium hydroxide, sodium hydroxide, sodium carbonate, sodium silicate, and sodium metasilicate, an ammonia solution, and hydroxide. Examples thereof include an etching solution containing alkali, hydrazine, and 1,3-dimethyl-2-imidazolidinone as main components. Examples of the organic alkaline solution include primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; dimethylethanolamine. , Alcohol amines such as triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; alkaline solutions such as cyclic amines such as pyrrole and piperidine.

Pure water and alcohols can be appropriately selected as the solvent for each of the above solutions. It is also possible to use a product to which an appropriate amount of a surfactant is added. The alkali concentration is, for example, 0.01 to 20% by mass.

As a physical method, for example, plasma (oxygen, argon, etc.), dry etching by corona discharge, polishing agent (for example, alumina (hardness 9), etc.) is dispersed in a liquid, and this is used as an aromatic polyimide film. A method of treating the surface of the polyimide film by irradiating the surface of the film at a rate of 30 to 100 m / s can be used.

The above method is preferable because it can be applied to any polyimide resin removing step before the fine particle removing step or after the fine particle removing step.

On the other hand, as a physical method applicable only to the polyimide resin removing step performed after the fine particle removing step, the target surface is pressure-bonded to a mount film (for example, a polyester film such as PET film) whose surface is wetted with a liquid, and then dried without drying or dried. Later, a method of peeling off the polyimide-based resin porous film from the mount film can also be adopted. Due to the surface tension or electrostatic adhesion of the liquid, the porous polyimide film is peeled off from the mount film while only the surface layer of the polyimide-based resin porous film is left on the mount film.

Further, in order to improve the wettability of the surface of the polyimide resin porous film with the organic solvent and remove residual organic substances, the polyimide resin porous film may be re-baked. The firing conditions may be appropriately set in the same manner as the firing conditions in (manufacturing of a polyimide resin-fine particle composite film (firing step)).

(Use of porous material)
The porous body according to the first aspect can be used for purification of an acrylic polymer.
By the above purification, a high molecular weight substance having a molecular weight of 30,000 or more in the molecular weight distribution of the acrylic polymer, specifically, a high molecular weight substance having a mass average molecular weight (Mw) of 30,000 or more of the acrylic polymer is removed. It is possible to remove a high molecular weight substance having a Mw of 50,000 or more.
The method for purifying the acrylic polymer will be described later in <Method for purifying the acrylic polymer>.
The acrylic polymer is preferably a resin used in a semiconductor manufacturing process, and more preferably a resin used for forming a resist film.
The resin used for forming the resist film is preferably a polar group-containing resin. Examples of the polar group-containing resin include resins having the structural unit (a3) described later. The polar group-containing resin may or may not contain the structural unit (a1) described later. Examples of the resin used for forming the resist film include a resin whose solubility in an alkali developer is increased by the action of an acid, an alkali-soluble resin, and the like, and a resin whose solubility in an alkali developer is increased by the action of an acid. , The alkali-soluble resin and the like may be the above-mentioned polar group-containing resin.

As a resin whose solubility in an alkaline developing solution is increased by the action of the acid, a "acid-degradable group" in which the hydrophilic group of a resin having a hydrophilic group (hydroxyl group, carboxy group, etc.) is protected by an acid dissociative protective group. It is preferable that the resin is the above.
Examples of the resin having a hydrophilic group include an acrylic resin having a structural unit derived from a (meth) acrylic acid ester.

Here, in the present specification, the "acid-degradable group" is a group having an acid-degradable property in which at least a part of the bonds in the structure of the acid-degradable group can be cleaved by the action of an acid.

The “constituent unit derived from the (meth) acrylic acid ester” means a structural unit formed by cleaving the ethylenic double bond of the (meth) acrylic acid ester. The "(meth) acrylic acid ester" includes a (meth) acrylic acid ester in which a hydrogen atom is bonded to a carbon atom at the α-position (a carbon atom to which a carbonyl group of (meth) acrylic acid is bonded), and an α-position. It also includes those in which a substituent (an atom or group other than a hydrogen atom) is bonded to a carbon atom. Examples of the substituent bonded to the carbon atom at the α-position include an alkyl group having 1 to 5 carbon atoms, an alkyl halide group having 1 to 5 carbon atoms, a hydroxyalkyl group and the like. The carbon atom at the α-position of the (meth) acrylic acid ester is a carbon atom to which the carbonyl group of the (meth) acrylic acid is bonded, unless otherwise specified.

As a resin whose solubility in an alkaline developer is increased by the action of an acid, an acrylic acid ester resin containing a structural unit derived from a (meth) acrylic acid ester having an acid-degradable group (hereinafter, also referred to as a resin (a)). .) Is preferable.

(Resin (a))
The resin (a) has an acid-degradable group. The resin (a) preferably has a structural unit (a1) derived from a (meth) acrylic acid ester containing an acid-degradable group. Further, the resin (a) preferably contains a structural unit lactone-containing cyclic group and has a structural unit (a2) derived from the (meth) acrylic acid ester. Further, the resin (a) is a structural unit (a3) derived from a (meth) acrylic acid ester containing a polar group-containing aliphatic hydrocarbon group, and / or a (meth) acrylic acid ester containing an aliphatic hydrocarbon group. It is preferable to have a structural unit (a4) derived from. The resin (a) can be used as a (meth) acrylic acid ester-inducing resin for a resist composition conventionally used in addition to the structural units (a1) to (a4) as long as the object of the present invention is not impaired. It may contain various structural units that are included. Hereinafter, the constituent units (a1) to (a4) will be described.

［式（ａ１−０−１）〜（ａ１−０−２）中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、Ｘ^ａ１は酸解離性基であり、Ｙ^ａ１は２価の連結基であり、Ｘ^ａ２は酸解離性基である。］ (Structural unit (a1))
The structural unit (a1) is a structural unit derived from a (meth) acrylic acid ester containing an acid-degradable group. The acid-decomposable group in the structural unit (a1) is decomposed by the action of an acid by exposure to increase the solubility of the resin (a) in an alkaline developer. The structural unit (a1) is a structural unit derived from a (meth) acrylic acid ester containing an acid-degradable group represented by the following formula (a1-0-1) or (a1-0-2). preferable.

[In the formulas (a1-0-1) to (a1-0-2), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms, and X ^a1 is an acid. It is a dissociative group, ^Ya1 is a divalent linking group, and ^Xa2 is an acid dissociative group. ]

As the acid dissociative group forming an acid-degradable group in the structural unit (a1),
(I) A group having acid dissociation that allows the bond between the acid dissociating group and an atom adjacent to the acid dissociating group to be cleaved by the action of an acid, or a group having acid dissociation.
(Ii) A group capable of cleaving the bond between the acid dissociative group and an atom adjacent to the acid dissociative group by further decarboxylation after the partial bond is cleaved by the action of the acid. ,
Refers to both.

Examples of (i) include a tertiary alkyl ester type acid dissociative group or an acetal type acid dissociative group. Examples of (ii) include a tertiary alkyloxycarbonyl group.
Examples of the tertiary alkyl ester type acid dissociative group are groups represented by the following formulas (1-1) to (1-9) and represented by the following formulas (2-1) to (2-6). The group etc. can be mentioned.

［式（１−１）〜（１−９）中、Ｒ^ａ４はアルキル基であり、ｇは０〜８の整数である。］

[In formulas (1-1) to (1-9), ^Ra4 is an alkyl group and g is an integer from 0 to 8. ]

［式（２−１）〜（２−６）中、Ｒ^ａ５及びＲ^ａ６は、それぞれ独立してアルキル基である。］

[In formulas (2-1) to (2-6), R ^a5 and R ^a6 are independently alkyl groups. ]

As the alkyl group of ^Ra4, a linear or branched alkyl group is preferable. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and particularly preferably 1 or 2 carbon atoms. Specific examples of the linear alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group and the like. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The number of carbon atoms of the branched-chain alkyl group is preferably 3 to 10, and more preferably 3 to 5. Specific examples of the branched alkyl group include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group and the like, and an isopropyl group is more preferable.

g is preferably an integer of 0 to 3, more preferably an integer of 1 to 3, and even more preferably 1 or 2.

^Examples of the alkyl group of R ^{a5 to} R ^a6 include those similar to the alkyl group of R ^a4 .

In the above formulas (1-1) to (1-9) and (2-1) to (2-6), some of the carbon atoms constituting the ring are replaced with ether oxygen atoms (-O-). May be. Further, in the above formulas (1-1) to (1-9) and (2-1) to (2-6), even if the hydrogen atom bonded to the carbon atom constituting the ring is substituted with a substituent. Good. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, and an alkyl fluorinated group.

Examples of the acetal-type acid dissociative group include a group represented by the following formula (p1).

［式（ｐ１）中、Ｒ^ａ７，Ｒ^ａ８はそれぞれ独立して水素原子又は炭素数１〜５のアルキル基を表し、ｎは０〜３の整数を表し、Ｙは炭素数１〜５のアルキル基又は脂肪族環式基を表す。］

[In the formula (p1), R ^a7 and R ^a8 independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, n represents an integer of 0 to 3, and Y represents an alkyl having 1 to 5 carbon atoms. Represents a group or an aliphatic cyclic group. ]

In the above formula (p1), n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0. As the alkyl group of R ^a7 and R ^a8 , a methyl group or an ethyl group is preferable.

Examples of the alkyl group of Y include the same alkyl groups as those mentioned as the substituent at the α-position in the above description of the acrylic acid ester. It may be bonded to R ^a7 . In this case, a cyclic group is formed by R ^a7 , Y, an oxygen atom to which Y is bonded, and a carbon atom to which an oxygen atom and R ^a7 are bonded. As the cyclic group, a 4- to 7-membered ring is preferable, and a 4- to 6-membered ring is more preferable. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

As the aliphatic cyclic group of Y, for example, one or more hydrogen atoms were removed from the monocycloalkane substituted or not substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group. Examples thereof include groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as groups, bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, one or more groups from monocycloalkanes such as cyclopentane and cyclohexane from which one or more hydrogen atoms have been removed, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Examples include groups excluding the hydrogen atom of. In addition, some of the carbon atoms constituting the ring of the group obtained by removing one or more hydrogen atoms from these monocycloalkanes or the group obtained by removing one or more hydrogen atoms from polycycloalkanes are ether oxygen atoms (-). It may be replaced with O-).

［式（ａ１−ｒ−３）中、Ｒａ’^７〜Ｒａ’^９はアルキル基である。］ Examples of the tertiary alkyloxycarbonyl group include groups represented by the following formula (a1-r-3).

In Expression (a1-r-3), Ra '7 ~Ra' 9 is an alkyl group. ]

Wherein (a1-r-3), Ra '7 ~Ra' 9 is preferably an alkyl group having 1 to 5 carbon atoms, 1 to 3 is more preferable.

As described above, examples of the structural unit (a1) include a structural unit represented by the following formula (a1-0-1), a structural unit represented by the following formula (a1-0-2), and the like.

［式（ａ１−０−１）〜（ａ１−０−２）中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、Ｘ^ａ１は酸解離性基であり、Ｙ^ａ１は２価の連結基であり、Ｘ^ａ２は酸解離性基である。］

[In the formulas (a1-0-1) to (a1-0-2), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms, and X ^a1 is an acid. It is a dissociative group, ^Ya1 is a divalent linking group, and ^Xa2 is an acid dissociative group. ]

In the formula (a1-0-1), the alkyl group of R and the alkyl halide group are the same as the alkyl group and the alkyl halide group mentioned as the substituents at the α-position in the above description of the acrylic acid ester, respectively. Things can be mentioned. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is more preferable.

X ^a1 is not particularly limited as long as it is an acid dissociable group, and examples thereof include the above-mentioned tertiary alkyl ester type acid dissociative group and acetal type acid dissociative group. Ester-type acid dissociative groups are preferred.

In the formula (a1-0-2), R is the same as above. Examples of X- ^a2 include acetal-type acid dissociative groups and groups represented by the above formula (a1-r-3). Examples of the divalent linking group of Y ^a1, not particularly limited, like for example an alkylene group, a divalent aliphatic cyclic group, a divalent aromatic cyclic group, and a divalent linking group containing a hetero atom Be done.

When Y ^a1 is an alkylene group, the number of carbon atoms thereof is preferably 1 to 10, more preferably 1 to 6, particularly preferably 1 to 4, and most preferably 1 to 3.

When Y ^a1 is a divalent aliphatic cyclic group, two or more hydrogen atoms are removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane or tetracyclododecane as the aliphatic cyclic group. A group is particularly preferable.

When Y ^a1 is a divalent aromatic cyclic group, examples of the aromatic cyclic group include a group obtained by removing two hydrogen atoms from an aromatic hydrocarbon ring which may have a substituent. .. The number of carbon atoms in the aromatic hydrocarbon ring is preferably 6 to 15. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, a phenanthrene ring, an anthracene ring and the like. Of these, a benzene ring or a naphthalene ring is particularly preferable.

When Y ^a1 is a divalent linking group containing a heteroatom, the divalent linking group containing a heteroatom includes -O-, -C (= O) -O-, -C (= O)-, -O-C (= O) -O-, -C (= O) -NH-, -NH- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S- _{, -S (= O) 2 -} , - S (= O) 2 -O-, wherein -A-O-B-, a group represented by the formula - [A-C (= O ) -O] m ' Examples thereof include groups represented by −B− and −A—O—C (= O) −B−. Here, the formula -A-O-B -, [ A-C (= O) -O] m '-B-, or -A-O-C (= O ) in -B-, A and B, Each is a divalent hydrocarbon group which may have a substituent independently, -O- is an oxygen atom, and m'is an integer of 0 to 3.

Y ^a1 is -A-O-B -, [ A-C (= O) -O] m '-B-, or -A-O-C (= O ) when it is -B-, A and B , Each independently is a divalent hydrocarbon group which may have a substituent. When a hydrocarbon group "has a substituent", it means that a part or all of hydrogen atoms in the hydrocarbon group are substituted with a group or atom other than a hydrogen atom.

The hydrocarbon group in A may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Aliphatic hydrocarbon groups mean hydrocarbon groups that do not have aromaticity. The aliphatic hydrocarbon group in A may be saturated or unsaturated, and is usually preferably saturated.

Specific examples of the aliphatic hydrocarbon group in A include a linear or branched aliphatic hydrocarbon group and an aliphatic cyclic group. The number of carbon atoms of the linear or branched aliphatic hydrocarbon group is preferably 1 to 10, more preferably 1 to 8, further preferably 2 to 5, and most preferably 2.

As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group, an ethylene group [-(CH ₂ ) _2- ], a trimethylene group [-(CH ₂ ) ₃ ). -], tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.

As the branched-chain aliphatic hydrocarbon group, a branched-chain alkylene group is preferable. Specifically, -CH (CH ₃ )-, -CH (CH ₂ CH ₃ )-, -C (CH ₃ ) _2- , -C (CH ₃ ) (CH ₂ CH ₃ )-, -C (CH) ₃ ) (CH ₂ CH ₂ CH ₃ )-, -C (CH ₂ CH ₃ ) ₂ -etc. Alkylmethylene groups; -CH (CH ₃ ) CH _2- , -CH (CH ₃ ) CH (CH ₃ )- Alkylethylene groups such as -C (CH ₃ ) ₂ CH _2- , -CH (CH ₂ CH ₃ ) CH _2- ; -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH ₂ - alkyl trimethylene groups such _{as; -CH (CH 3) CH 2} CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - such as an alkyl alkylene groups such as alkyl tetramethylene group like the Be done. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

These linear or branched aliphatic hydrocarbon groups may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group obtained by removing two hydrogen atoms from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic group, a group obtained by removing two hydrogen atoms from a polycycloalkane having 7 to 12 carbon atoms is preferable, and as the polycycloalkane, specifically, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclo. Dodecane and the like can be mentioned.

As A, a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or an ethylene group is particularly preferable. ..

As B, a linear or branched aliphatic hydrocarbon group is preferable.

Further, in the group represented by the formula − [AC (= O) −O] _{m ′} −B−, m ′ is an integer of 0 to 3, preferably an integer of 0 to 2, and is 0. Or 1 is more preferable, and 1 is most preferable.

A specific example of the structural unit represented by the above formula (a1-0-1) is shown below. In each of the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

A specific example of the structural unit represented by the above formula (a1-0-2) is shown below. In each of the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The ratio of the constituent unit (a1) in the resin (a) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, and 25 to 50 mol% with respect to all the constituent units constituting the resin (a). Is even more preferable. By setting the ratio of the structural unit (a1) to such a range, it is easy to prepare a resist composition in which a pattern can be easily formed.

(Structural unit (a2))
The structural unit (a2) is a structural unit derived from a (meth) acrylic acid ester containing a lactone-containing cyclic group, and is acid-degradable represented by the following formula (a2-1) or (a2-2). A structural unit derived from a (meth) acrylic acid ester containing a group. Here, the lactone-containing cyclic group refers to a cyclic group containing one ring (lactone ring) containing a —OC (= O) -structure. The lactone ring is counted as the first ring, and when it has only a lactone ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of its structure.

The lactone cyclic group of the structural unit (a2) is effective in that when the resin (a) is used for forming the resist film, the adhesion of the resist film to the substrate can be enhanced.

［式（ａ２−１）〜（ａ２−２）中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、Ｘ^ａ５はラクトン含有環式基であり、Ｙ^ａ４は２価の連結基であり、Ｘ^ａ６はラクトン含有環式基である。］

[In the formulas (a2-1) to (a2-2), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms, and X ^a5 is a lactone-containing cyclic group. Y ^a4 is a divalent linking group, and X ^a6 is a lactone-containing cyclic group. ]

In the formula (a2-1) ~ ^(a2-2), specific examples of ^{Y a4} include the same as the previously described ^{Y a1.}

In the formulas (a2-1) to (a2-2), any lactone cyclic group of X ^a5 or X ^a6 can be used without particular limitation. Specifically, the lactone-containing monocyclic group is a group obtained by removing one hydrogen atom from a 4- to 6-membered ring lactone, for example, a group obtained by removing one hydrogen atom from β-propionolactone, or γ-butyrolactone. Examples thereof include a group from which one hydrogen atom has been removed, a group from which one hydrogen atom has been removed from δ-valerolactone, and the like. Examples of the lactone-containing polycyclic group include a bicycloalkane having a lactone ring, a tricycloalkane, and a tetracycloalkane from which one hydrogen atom has been removed.

A specific example of the structural unit (a2) is shown below. In each of the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

In the resin (a), as the constituent unit (a2), one type may be used alone, or two or more types may be used in combination. The ratio of the constituent unit (a2) in the resin (a) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, and 20 to 50 mol% with respect to the total of all the constituent units constituting the resin (a). Mol% is more preferred.

(Structural unit (a3))
The structural unit (a3) is a structural unit (a3) derived from a (meth) acrylic acid ester containing a polar group-containing hydrocarbon group. The polar group-containing hydrocarbon group is a polar group-containing aliphatic hydrocarbon group or a polar group-containing aromatic hydrocarbon group, and a polar group-containing aliphatic hydrocarbon group is preferable. When the resin (a) has the structural unit (a3), the hydrophilicity of the resin (a) is increased, and the sensitivity, resolution, lithography characteristics, and the like are improved. The structural unit (a3) is a structural unit that does not correspond to the above-mentioned structural unit (a1) and (a2). That is, even if there is a "constituent unit derived from a (meth) acrylic acid ester containing a polar group-containing hydrocarbon group", the structural unit corresponding to any of the above structural units (a1) and (a2) is a constitutional unit. It does not correspond to the unit (a3).

Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, a fluorinated alcohol group (a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is replaced with a fluorine atom) and the like. Among these, a hydroxyl group and a carboxy group are preferable, and a hydroxyl group is particularly preferable.

In the structural unit (a3), the number of polar groups bonded to the aliphatic hydrocarbon group is not particularly limited, but is preferably 1 to 3, and most preferably 1.

As the structural unit (a3), a structural unit represented by the following formula (a3-1) is preferable.

［式（ａ３−１）中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、Ｘ^ａ７は１＋ｍ価の脂肪族炭化水素基であり、ｍは１〜３の整数である。］

[In the formula (a3-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms, and X ^a7 is a 1 + m-valent aliphatic hydrocarbon group. m is an integer of 1-3. ]

The 1 + m-valent aliphatic hydrocarbon group as X ^a7 may be saturated or unsaturated, and is preferably saturated. Specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group having a ring in the structure.

The "linear or branched aliphatic hydrocarbon group" preferably has 1 to 12 carbon atoms, more preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms. In the linear or branched aliphatic hydrocarbon group, a part or all of hydrogen atoms may be substituted with a substituent other than the polar group. Examples of the substituent other than the polar group include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like. Further, in the linear or branched aliphatic hydrocarbon group, a divalent group containing a hetero atom may be interposed between carbon atoms. 2 As the "divalent group containing a hetero atom" in the description of the structural unit (a1), structural units containing the divalent linking groups as the Y ^a1 in the formula (a1-0-2) "heteroatom The same as the "linking group of valence" can be mentioned.

As the "aliphatic hydrocarbon group containing a ring in the structure", a cyclic aliphatic hydrocarbon group or a cyclic aliphatic hydrocarbon group is bonded to the terminal of the above-mentioned chain aliphatic hydrocarbon group or a chain. Examples thereof include a group intervening in the middle of the aliphatic hydrocarbon group. The cyclic aliphatic hydrocarbon group preferably has 3 to 30 carbon atoms. Further, the cyclic aliphatic hydrocarbon group may be a polycyclic type or a monocyclic type, and a polycyclic type is preferable.

As the cyclic aliphatic hydrocarbon group, specifically, for example, in a resin for a resist composition for an ArF excimer laser, it can be appropriately selected from a large number of proposals and used. For example, the monocyclic aliphatic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane having 3 to 20 carbon atoms, and examples of the monocycloalkane include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane having 7 to 30 carbon atoms, and specifically, the polycycloalkane is adamantane, norbornane, isobornane, or tri. Cyclodecane, tetracyclododecane and the like can be mentioned.

In the cyclic aliphatic hydrocarbon group, a part or all of hydrogen atoms may be substituted with a substituent other than the above-mentioned polar group. Examples of the substituent other than the polar group include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

The structural unit (a3) contained in the resin (a) may be one type or two or more types. When the resin (a) has the constituent unit (a3), the ratio of the constituent unit (a6) in the resin (a) is 1 to 50 mol% with respect to the total of all the constituent units constituting the resin (a). Preferably, 5 to 40 mol% is more preferable, and 5 to 25 mol% is further preferable.

[Structural unit (a4)]
The structural unit (a4) is a structural unit (a4) derived from an acrylic acid ester containing an aliphatic hydrocarbon group. The aliphatic hydrocarbon group contained in the structural unit (a4) does not contain the polar group described in the structural unit (a3). Since the resin (a) has the structural unit (a4), the glass transition temperature (Tg) of the resin can be changed, and the characteristics of the formed resist film can be improved.

As the structural unit (a4), a structural unit represented by the following formula (a4-1) is preferable.

［式（ａ４−１）中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、Ｘ^ａ８は脂肪族炭化水素基である。］

[In the formula (a4-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms, and X ^a8 is an aliphatic hydrocarbon group. ]

The aliphatic hydrocarbon group as X ^a8 may be saturated or unsaturated, and is preferably saturated. Specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group having a ring in the structure.

The "linear or branched aliphatic hydrocarbon group" preferably has 1 to 12 carbon atoms, more preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms. In the linear or branched aliphatic hydrocarbon group, a part or all of hydrogen atoms may be substituted with a substituent other than the polar group. Examples of the substituent other than the polar group include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like. Further, in the linear or branched aliphatic hydrocarbon group, a divalent group containing a hetero atom may be interposed between carbon atoms. 2 As the "divalent group containing a hetero atom" in the description of the structural unit (a1), structural units containing the divalent linking groups as the Y ^a1 in the formula (a1-0-2) "heteroatom The same as the "linking group of valence" can be mentioned.

As the "aliphatic hydrocarbon group containing a ring in the structure", a cyclic aliphatic hydrocarbon group or a cyclic aliphatic hydrocarbon group is bonded to the terminal of the above-mentioned chain aliphatic hydrocarbon group or a chain. Examples thereof include a group intervening in the middle of the aliphatic hydrocarbon group. The cyclic aliphatic hydrocarbon group preferably has 3 to 30 carbon atoms. Further, the cyclic aliphatic hydrocarbon group may be a polycyclic type or a monocyclic type, and a polycyclic type is preferable.

As the cyclic aliphatic hydrocarbon group, specifically, for example, in a resin for a resist composition for an ArF excimer laser, it can be appropriately selected from a large number of proposals and used. For example, the monocyclic aliphatic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane having 3 to 20 carbon atoms, and examples of the monocycloalkane include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane having 7 to 30 carbon atoms, and specifically, the polycycloalkane is adamantane, norbornane, isobornane, or tri. Cyclodecane, tetracyclododecane and the like can be mentioned.

In the cyclic aliphatic hydrocarbon group, a part or all of hydrogen atoms may be substituted with a substituent other than the above-mentioned polar group. Examples of the substituent other than the polar group include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

The structural unit (a4) contained in the resin (a) may be one type or two or more types. When the resin (a) has the structural unit (a4), the ratio of the structural unit (a6) in the resin (a) is 5 to 60 mol% with respect to the total of all the structural units constituting the resin (a). Preferably, 10 to 50 mol% is more preferable, and 20 to 50 mol% is further preferable.

The polystyrene-equivalent mass average molecular weight of the resin whose solubility in an alkaline developer is increased by the action of an acid is preferably 1,000 to 600,000, more preferably 5,000 to 400,000, and even more preferably 7,000 to 3,000,000. By setting such a mass average molecular weight, sufficient strength of the resin film can be maintained without deteriorating the peelability from the base material.

Further, the resin (B) is preferably a resin having a dispersity of 1.05 or more. Here, the degree of dispersion is a value obtained by dividing the mass average molecular weight by the number average molecular weight. With such a dispersion degree, a desired stress tolerance can be obtained.

The acrylic polymer may be an alkali-soluble resin.
Here, the alkali-soluble resin is a resin solution having a resin concentration of 20% by mass (solvent: propylene glycol monomethyl ether acetate) to form a resin film having a thickness of 1 μm on a substrate to form a 2.38% by mass TMAH aqueous solution. A substance that dissolves in an amount of 0.01 μm or more when immersed for 1 minute.
When the acrylic polymer is an alkali-soluble resin, it preferably contains a structural unit derived from a polymerizable compound having an ether bond and a structural unit derived from a polymerizable compound having a carboxyl group.

Examples of the polymerizable compound having an ether bond include 2-methoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethylcarbitol (meth) acrylate, and phenoxypolyethylene glycol ( Examples thereof include (meth) acrylic acid derivatives having ether bonds and ester bonds such as meth) acrylates, methoxypolypropylene glycol (meth) acrylates, and tetrahydrofurfuryl (meth) acrylates. The polymerizable compound having an ether bond is preferably 2-methoxyethyl acrylate or methoxytriethylene glycol acrylate. These polymerizable compounds may be used alone or in combination of two or more.

Examples of the polymerizable compound having a carboxyl group include monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid; 2-methacryloyloxyethyl succinic acid and 2-methacryloyloxy. Examples of compounds having a carboxyl group and an ester bond such as ethylmaleic acid, 2-methacryloyloxyethyl phthalic acid, 2-methacryloyloxyethyl hexahydrophthalic acid; and the like can be exemplified. The polymerizable compound having a carboxyl group is preferably acrylic acid or methacrylic acid. These polymerizable compounds may be used alone or in combination of two or more.

The mass average molecular weight of the alkali-soluble resin (Mw: measured value by gel permeation chromatography (GPC) in terms of polystyrene. The same applies herein) is preferably 2000 to 20000, more preferably 2000 to 18000, and 3000 to 15000. Especially preferable.

<Filter, filter media or filter device equipped with the above filter>
The filter, filter media, or filter device according to the second aspect includes the porous body according to the first aspect.
The filter can be used, for example, as a filter used for purifying an acrylic polymer (preferably an acrylic polymer used in the field of semiconductor manufacturing).
The filter media can be used, for example, as a filter medium used for purifying an acrylic polymer (preferably an acrylic polymer used in the field of semiconductor manufacturing), or as a laminate containing the filter media and another filter medium. Can also be used and can also be used as a filter device.
The film thickness of the filter or the filter media is not particularly limited, but is preferably 5 μm or more and 500 μm or less, more preferably 10 μm or more and 100 μm or less, and particularly preferably 10 μm or more and 40 μm or less. The above film thickness can be obtained by measuring and averaging the thicknesses of a plurality of locations with, for example, a micrometer.

The filter device is not particularly limited, but in the filter device, the porous body according to the first aspect is arranged so that the feed solution and the filter solution intersect with each other. In relation to the liquid flow path, it may be arranged in parallel with the flow path or may be arranged so as to intersect with the flow path. The regions before and after passing the porous body according to the first aspect are appropriately sealed so that the feed solution is separated from the filtrate. For example, as a sealing method, if necessary, the porous body according to the first aspect is bonded by light (UV) curing or heat (including adhesion by anchor effect (heat welding, etc.)), or It may be processed by adhesion using an adhesive or the like, or the porous body according to the first aspect and another filter medium (filter) can be used by adhering them by, for example, an incorporation method. The outer side of the porous body according to the above aspect is further made of a thermoplastic resin such as polyethylene, polypropylene, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polyether sulfone (PES), polyimide, polyamideimide or the like. It can be used in preparation for a container.

<Acrylic polymer purification method>
The method for purifying the acrylic polymer according to the third aspect is to filter the liquid containing the acrylic polymer with the porous body according to the first aspect or the filter, filter media or filter device according to the second aspect. Including.
In terms of improving the occurrence of defects in the lithography process, it is considered that the effect will be greater when the acrylic polymer to be purified is a polar group-containing resin.
Examples of the solvent contained in the liquid containing the acrylic polymer include conventionally known ones, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, and ethylene glycol mono-n-butyl ether. , Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene Glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene (Poly) alkylene glycol monoalkyl ethers such as glycol monomethyl ether, tripropylene glycol monoethyl ether, butanediol monomethyl ether, butanediol monoethyl ether, butanediol monopropyl ether; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether (Poly) alkylene glycol monoalkyl ether acetates such as acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate; diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, Other ethers such as propylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran; ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone; methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, butyl acetate, ethyl lactate , Lactic acid alkyl esters such as butyl lactate; ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, 3-meth Ethyl toxipropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methyl part carbonate, 3-methyl-3-methoxybutyl acetate, 3- Methyl-3-methoxybutyl propionate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-pentyl formate, isopentyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate , Isopropyl butyrate, n-butyl butylate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl 2-oxobutate and other esters; aromatics such as toluene and xylene. Hydrocarbons; amides such as N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone , Ε-Caprolactone and other organic solvents such as lactone-based polar solvents. A water-soluble solvent may be used, and the water-soluble solvent includes methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and 2-methyl-1 in addition to those showing water solubility as described above. -Alcoholic solvents such as propanol, acetone, methanol and the like can also be mentioned. These may be used alone or in combination of two or more.

Among these, at least one selected from the group consisting of (poly) alkylene glycol monoalkyl ethers; (poly) alkylene glycol monoalkyl ether acetates; ketones excluding cyclohexanone; lactate alkyl esters; is contained. This is preferable from the viewpoint of purification of the high molecular weight compound. More preferably, it is at least one selected from the group consisting of propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and 2-heptanone.

By the above filtration, a part or all of the high molecular weight body in which the Mw of the acrylic polymer contained in the liquid is preferably 30,000 or more can be removed from the liquid.
The acrylic polymer to be removed is preferably a high molecular weight body of Mw 50,000 or more, more preferably a high molecular weight body of Mw 600,000 or more, further preferably a high molecular weight body of Mw 1.2 million or more, and Mw 150. It is particularly preferable that the molecular weight is 10,000 or more.
The upper limit of Mw of the acrylic polymer to be removed is not particularly limited, but is preferably 15 million or less, more preferably 10 million or less, further preferably 5 million or less, and 3 million. The following is particularly preferable.
The removal rate (%) of the acrylic polymer according to the purification method according to the third aspect is the content of the acrylic polymer removed by filtration in the liquid with respect to the content of the acrylic polymer in the liquid before filtration. It can be calculated from the quantity.
The removal rate (%) of the acrylic polymer having Mw 600,000 or more can be, for example, 50% or more, preferably 60% or more.
The removal rate (%) of the acrylic polymer having Mw 1.2 million or more can be, for example, 75% or more, preferably 80% or more, and more preferably 85% or more.

In the method for purifying an acrylic polymer according to a third aspect, the filtration performs a part or all of the liquid containing the acrylic polymer with the porous body according to the first aspect or the filter according to the second aspect. It is preferable to transmit the filter media or the filter device from one side to the other side by a differential pressure.

Regarding the form in which the porous body according to the first aspect or the filter or filter media according to the second aspect is used in the method for purifying the acrylic polymer according to the third aspect, it is planar or porous according to the first aspect. Examples thereof include a structure or a pipe shape in which the opposing sides of the filter or filter media according to the second aspect are combined. It is preferable that the pipe-shaped porous body according to the first aspect or the filter or filter media according to the second aspect is further formed into a fold shape because the area in contact with the supply liquid increases. The porous body according to the first aspect or the filter or filter media according to the second aspect is appropriately sealed so that the feed solution and the filtrate are not mixed as described later.

Purification of the liquid containing the acrylic polymer is also carried out by using the porous body according to the first aspect described above or the filter or filter media according to the second aspect without differential pressure, that is, by natural filtration by gravity. Although it can be done, it is preferable to carry out by differential pressure. The differential pressure is not particularly limited as long as a pressure difference is provided between one side and the other side of the porous body according to the first aspect or the filter or filter media according to the second aspect. Usually, a pressure (positive pressure) for applying pressure to one side (supply liquid side) of the porous body according to the first aspect or the filter or filter media according to the second aspect, the porous according to the first aspect. Examples thereof include decompression (negative pressure) in which one side (filament side) of the body or the filter or filter media according to the second aspect is made negative pressure. When the pressure on the filtrate side is reduced, it is also preferable in that it also removes the gas remaining or dissolved in the liquid containing the acrylic polymer after purification.

Pressurization is the side (supply) on which the porous body according to the first aspect or the liquid (sometimes referred to as “supply liquid” in the present specification) before being permeated through the filter or filter media according to the second aspect is present. The pressure is applied to the liquid side), and for example, the pressure is preferably applied by utilizing the flowing pressure generated by the circulation or feeding of the supply liquid or by utilizing the positive pressure of the gas. The flow pressure can be generated by an aggressive flow pressure addition method such as a pump (liquid feed pump, circulation pump, etc.), and specifically, a rotary pump, a diaphragm pump, a metering pump, a chemical pump, etc. Examples thereof include a plunger pump, a bellows pump, a gear pump, a vacuum pump, an air pump, and a liquid pump. The flow pressure may be, for example, the pressure applied by the liquid to the porous body according to the first aspect or the filter or filter media according to the second aspect when the liquid is permeated only by gravity. , It is preferable that the pressure is applied by the above-mentioned positive flow pressure application method. The gas used for pressurization is preferably a gas that is inert or non-reactive with respect to the feed solution, and specific examples thereof include nitrogen and a rare gas such as helium and argon. In the field of manufacturing electronic materials, particularly semiconductors, the side that collects the porous body according to the first aspect or the filter or the liquid that has passed through the filter media according to the second aspect may be pressurized at atmospheric pressure without depressurization. The positive pressure by gas is preferable. In the above pressurization method, a pressurizing valve or a valve such as a pressurizing valve or a three-way valve may be used.
The depressurization is to depressurize the side (filtrate side) that collects the liquid that has passed through the porous body according to the first aspect or the filter or filter media according to the second aspect, and for example, even if the decompression is performed by a pump. It is good, but it is preferable to reduce the pressure to vacuum.
When the feed liquid is circulated or sent by the pump, the pump usually has a feed liquid tank (or a circulation tank) and a porous body according to the first aspect or a filter or filter media according to the second aspect. Placed in between.

Pressurization may utilize both the fluid pressure and the positive pressure of the gas. Further, the differential pressure may be a combination of pressurization and depressurization, for example, those using both fluid pressure and depressurization, those utilizing both positive pressure and depressurization of gas, fluid pressure and pressure. It may utilize the positive pressure and the reduced pressure of the gas. When the method of providing the differential pressure is combined, the combination of the fluid pressure and the positive pressure of the gas and the combination of the fluid pressure and the reduced pressure are preferable from the viewpoint of simplification of production and the like.

The pressure difference applied before and after the porous body according to the first aspect or the filter or filter media according to the second aspect by providing the differential pressure is the porous body according to the first aspect to be used or the second aspect. The filter or filter media according to the above aspect may be appropriately set according to the film thickness, porosity or average pore size, desired degree of purification, flow rate, flow rate, concentration or viscosity of the feed solution, etc., but for example, the so-called cross-flow method. In the case of (flowing the feed solution in parallel with the porous body according to the first aspect or the filter or filter media according to the second aspect), for example, it is 3 MPa or less, and is a so-called dead end method (first aspect). In the case of (flowing the feed solution so as to intersect the porous body according to the second aspect or the filter or the filter media according to the second aspect), for example, it is 1 MPa or less. The lower limit is not particularly limited, and is, for example, 10 Pa.

In the method for purifying an acrylic polymer according to a third aspect, a part or all of the liquid is applied from one side to the other side of the porous body according to the first aspect or the filter or filter media according to the second aspect. Upon permeation, the feed solution may be appropriately diluted with a diluent.

In the method for purifying an acrylic polymer according to a third aspect, cleaning or wettability of the porous body according to the first aspect or the filter or filter media according to the second aspect to the supply solution before permeating the supply solution. The first embodiment uses a solution of alcohol such as methanol, ethanol, isopropyl alcohol or ketone such as acetone or methyl ethyl ketone, water, a solvent contained in the feed solution or a mixture thereof for improvement or surface energy adjustment with the feed solution. The liquid may be passed through contact with the porous body according to the above or the filter or the filter media according to the second aspect.
In the contact between the porous body according to the first aspect or the filter or filter media according to the second aspect and the above solution before permeating the feed solution, the porous body according to the first aspect or the second aspect The filter or filter media according to the above may be impregnated or immersed in the solution, and by contacting the porous body according to the first aspect or the filter or filter media according to the second aspect with the solution, for example, first. The solution can also be permeated into the pores inside the porous body according to the above aspect or the filter or the filter media according to the second aspect. The contact between the porous body according to the first aspect or the filter or filter media according to the second aspect and the above solution before permeating the feed solution may be performed by the above-mentioned differential pressure, and in particular, the first aspect. When the solution is allowed to permeate into the pores inside the porous body according to the embodiment or the filter or filter media according to the second aspect, it may be carried out under pressure.

In the method for purifying the acrylic polymer according to the third aspect, the porous body according to the first aspect has an average pore size of 15 nm or less by the BET method as described above, so that the porous body is mainly separated. Depending on the type of the constituent resin, it is considered that a part or all of the high molecular weight body of the acrylic polymer having a Mw of 30,000 or more is removed from the liquid before the treatment by further adsorption. As used herein, the term "separation" may include at least one selected from the group consisting of filtration, isolation, removal, capture, purification and sieving.

In the method for purifying an acrylic polymer according to a third aspect, the porous body according to the first aspect can be used, for example, as a filter medium or other filter medium, and specifically, it may be used alone. , Another functional layer (membrane) may be imparted by using as a filter medium, or it may be used as a membrane to be combined with another filter medium, and for example, it may be used as a membrane used for a filter device or the like. The functional layer that can be used in combination with the porous material according to the first aspect is not particularly limited, and for example, a nylon film, a polytetrafluoroethylene (PTFE) film, or a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer. Examples thereof include those having a chemical or physicochemical function such as a (PFA) film or a film modified thereto.

In the method for purifying an acrylic polymer according to the third aspect, the filter device is not particularly limited, but in the filter device, the porous body according to the first aspect or the filter or filter media according to the second aspect is supplied. The liquid and the filtrate are arranged so as to intersect each other. In relation to the liquid flow path, it may be arranged in parallel with the flow path or may be arranged so as to intersect with the flow path. The area before and after passing the porous body according to the first aspect or the filter or filter media according to the second aspect is appropriately sealed so that the feed solution is separated from the filter solution. For example, as a sealing method, the porous body according to the first aspect or the filter or filter media according to the second aspect is bonded by light (UV) curing or heat bonding (adhesion by the anchor effect), if necessary. (Including heat welding, etc.))), or may be processed by adhesion using an adhesive, or the porous body according to the first aspect or the filter or filter media according to the second aspect and other filter media. (Filter) can be used by adhering to, for example, by an incorporation method or the like, and the porous body according to the first aspect or the filter or filter media according to the second aspect can be further added to polyethylene, polypropylene, tetrafluoroethylene. -It can be used for an outer container made of a thermoplastic resin such as a perfluoroalkyl vinyl ether copolymer (PFA), a polyether sulfone (PES), a polyimide, or a polyamideimide.

The method for purifying an acrylic polymer according to the third aspect is also a circulation type purification method in which a liquid is constantly circulated and the porous body according to the first aspect or the filter or filter media according to the second aspect is permeated. It can be preferably applied.

<Manufacturing method of acrylic polymer>
As the method for producing the acrylic polymer according to the fourth aspect, the method for purifying the acrylic polymer according to the third aspect is used.
Since the method for purifying the acrylic polymer according to the third aspect is a method having excellent purification ability as described above, the production method according to the fourth aspect is a high molecular weight polymer having a Mw of 30,000 or more (preferably Mw50,000). It is possible to produce an acrylic polymer in which the above high molecular weight material) is reduced.
The produced acrylic polymer is preferably a polar group-containing resin, a resin whose solubility in an alkali developer is increased by the action of an acid, or an alkali-soluble resin.

<Manufacturing method of photosensitive resin composition>
As the method for producing the photosensitive resin composition according to the fifth aspect, the method for purifying the acrylic polymer according to the third aspect or the method for producing the acrylic polymer according to the fourth aspect is used.
When a pattern (for example, a resist pattern) is formed by using a resin or an alkali-soluble resin whose solubility in an alkali developer is increased by the action of the acid which is the produced acrylic polymer in the photosensitive resin composition, it is developed. Subsequent residues, development defects, etc. can be reduced.

As a method for producing the photosensitive resin composition, a resin or an alkali-soluble resin whose solubility in an alkali developing solution is increased by the action of an acid which is an acrylic polymer after purification is used as another optional component (for example, solvent, light). It may be simply mixed and stirred together with an acid generator or the like in a usual manner, and if necessary, it may be dispersed and mixed using a disperser such as a dissolver, a homogenizer, or a three-roll mill. Further, after mixing, the mixture may be further filtered using a mesh, a membrane filter or the like.
As the resin whose solubility in an alkaline developer is increased by the action of an acid, which is an acrylic polymer after purification, one type may be used alone, or two or more types may be used in combination.
As for the alkali-soluble resin which is the acrylic polymer after purification, one type may be used alone, or two or more types may be used in combination.
The content of the resin and the alkali-soluble resin whose solubility in the alkaline developer is increased in the photosensitive resin composition is not particularly limited, and is appropriately adjusted according to the resist film thickness to be formed and the like.
The photosensitive resin composition to be produced is preferably a photosensitive resin composition for active light or radiation exposure (for example, for selectively irradiating or exposing ultraviolet rays or visible light having a wavelength of 300 to 500 nm).
Examples of the active ray or radiation include microwave, infrared ray, visible ray, ultraviolet ray, X-ray, γ-ray, electron beam, proton beam, neutron beam, ion beam and the like, and ArF exposure is preferable.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to these Examples.

<Examples 1 and 2>
Using a varnish containing polyamic acid and silica fine particles, a polyimide porous body having an average pore size by the BET method shown in Table 1 was obtained by the above-mentioned method for producing a porous body. In addition, in Example 1 and Example 2, the chemical etching conditions by the alkaline solution are changed.

The average pore size of the porous polyimide films of Examples 1 and 2 was calculated by the above-mentioned BET method (adsorption molecule: nitrogen).
In addition, as Comparative Example 1, a commercially available nylon film (pore diameter 10 nm by the bubble point method is indicated in the catalog) and as Comparative Example 2 a commercially available ultra-high molecular weight polyethylene film (pore diameter 3 nm is indicated in the catalog) are also averaged by the BET method. The hole diameter was calculated.
The results are shown in Table 1 below.

<Acrylic polymer filtration test 1>
A filtration test of an acrylic polymer was carried out using the porous polyimide film of Example 1 and the nylon film of Comparative Example 1.
As acrylic polymers, acrylic polymers having Mw 1.2 million and Mw 600,000 represented by the following formulas were prepared, respectively. The composition ratio in the following formula is a molar ratio.

The average particle size of the acrylic polymer having Mw 1.2 million by the dynamic light scattering method was 53.8 nm, and the average particle size of the acrylic polymer having Mw 600,000 by the dynamic light scattering method was 9.8 nm.

The above acrylic polymer having Mw 1.2 million was mixed with a mixed solvent (PGMEA: PGME = 6: 4 (mass ratio)) of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) so as to have a concentration of 50 ppm. Each 50 mL of the liquid and the liquid mixed with the above acrylic polymer having Mw 600,000 so as to be 50 ppm were filtered under reduced pressure (20 kPa) for 1 hour with the porous polyimide film of Example 1 and the nylon film of Comparative Example 1, respectively. ..
The porous polyimide film of Example 1 was used by stacking two films having a diameter of 47 mm and a film thickness of 20 μm, and the nylon film of Comparative Example 1 was a film having a diameter of 47 mm and a film thickness of 40 μm.
The mixed solvent was distilled off from the obtained filtrate under reduced pressure, and the weight of the non-volatile component was measured. From the results, the porous polyimide film of Example 1 and the nylon film of Comparative Example 1 had Mw 1.2 million and 600,000 acrylic polymers. Each removal rate (%) was calculated.
The results are shown in Table 2.

As is clear from the results shown in Table 2, it can be seen that the porous polyimide film of Example 1 has a higher removal rate for both Mw1.2 million and Mw600,000 acrylic polymers than the nylon film of Comparative Example 1. ..

<Acrylic polymer filtration test 2>
The selective removal of the high molecular weight acrylic polymer by the porous polyimide film of Example 1 and the commercially available porous film of Comparative Example 2 was tested.
As acrylic polymers, acrylic polymers represented by the above formulas of Mw 1.5 million, Mw 50,000 and Mw 10,000 were prepared, respectively.
In 50 mL of the mixed solvent (PGMEA: PGME = 6: 4 (mass ratio)), the acrylic polymers having Mw 1.5 million, Mw 50,000 and Mw 10,000 were mixed at a mass ratio of 1: 1: 1 so as to have a total of 50 ppm. The liquid was filtered under reduced pressure (80 kPa) for 1 hour with each porous film.
Gel permeation chromatography (GPC) was performed on the above mixed solution before and after filtration.
The gel filtration conditions were detector: RI (refractive index), eluent: tetrahydrofuran, flow rate: 1 mL / min, column: Agilent Technologies Plgel MIXED-D x 2.
As a result of the above test, the acrylic polymer having a Mw of 10,000 or less was not removed from the porous polyimide film of Example 1 and the commercially available porous film of Comparative Example 2.
Further, in the porous polyimide film of Example 1, the high molecular weight of Mw of about 30,000 or more is gradually removed as the value of Mw increases, the acrylic polymer of Mw of about 30,000 is also removed, and the acrylic polymer of Mw of about 1.5 million is removed. Was found to be virtually completely removed.
On the other hand, in Comparative Example 2, it was confirmed that Mw1.5 million and Mw50,000 were not removed (there was almost no difference when compared with the waveform (molecular weight distribution) of GPC before filtration).

<Acrylic polymer filtration test 3>
Regarding the porous polyimide film of Example 1, the mixed solvent (PGMEA: PGME = 6: 4 (mass ratio)) was changed to 2-heptanone alone and PGME alone, but in the same manner as in the above filtration test 2, respectively. Evaluation was performed.
As a result of the above test, the acrylic polymer having Mw of 10,000 or less was not removed by any of the single solvents, but the removal rate of Mw 30,000 was improved and the dispersity was narrowed (Mw 10,000 was the apex). It was confirmed that the half-value width of the peak decreased to about 1/2).

Claims (15)

The average pore size measured by the BET method is Ri der less 15 nm, polyimide, polyamideimide, and the porous body comprising at least one porous membrane is selected from the group consisting of polyether sulfone. The porous body according to claim 1, wherein the porous body has a garley air permeability of 10 to 500 seconds. The porous body according to claim 1 or 2 , wherein the porosity of the porous body is 50 to 90% by mass. The porous body according to any one of claims 1 to 3 , which is used for purifying an acrylic polymer. The porous body according to claim 4 , wherein the purification is a purification for removing a high molecular weight substance having a mass average molecular weight (Mw) of 30,000 or more of the acrylic polymer. The porous body according to claim 4 or 5 , wherein the acrylic polymer is a resin used for forming a resist film. A filter comprising the porous material according to any one of claims 1 to 6 . A filter medium containing the porous material according to any one of claims 1 to 6 . A filter device comprising the porous material according to any one of claims 1 to 6 . The porous body according to the liquid containing the acrylic polymer to any one of claim 1 to 6 filter according to claim 7, the filter media of claim 8, or a filter according to claim 9 A method for purifying an acrylic polymer, which comprises filtering by a device. The purification according to claim 10 , wherein by the filtration, a part or all of the high molecular weight polymer having a mass average molecular weight (Mw) of 30,000 or more contained in the liquid is removed from the liquid. Method. A method for producing an acrylic polymer using the purification method according to claim 10 or 11 . The production method according to claim 12 , wherein the acrylic polymer is a polar group-containing resin. The production method according to claim 12 or 13 , wherein the acrylic polymer is a resin or an alkali-soluble resin whose solubility in an alkali developer is increased by the action of an acid. A method for producing a photosensitive resin composition containing an acrylic polymer.
The acrylic polymer is a photosensitive resin composition that is an acrylic polymer purified by the purification method according to claim 10 or 11 , or an acrylic polymer produced by the production method according to any one of claims 12 to 14. How to make things.