JP2024146913A - Plastic substrate with film made of photocured product of photosensitive resin composition and method for producing same - Google Patents

Abstract

[Problem] To provide a plastic substrate with a photocured film of a photosensitive resin composition using a polymer that can produce a pattern by photolithography. [Solution] A film-attached plastic substrate is provided on the surface of the plastic substrate with a film (C) consisting of a photocured product of a composition that includes a polymer (A) having a structural unit represented by the following formula (1) and that may include an optionally substituted aryl ketone (B), in which when the composition does not include the aryl ketone (B), the polymer (A) may have a residue of the aryl ketone (B), and when the composition includes the aryl ketone (B), the polymer (A) may have a residue of the aryl ketone (B). TIFF2024146913000015.tif52170 [Selected Figure] None

Description

The present invention relates to a film-attached plastic substrate made of a photocured product of a photosensitive resin composition, and to a film-attached plastic substrate and a method for producing the film-attached plastic substrate.

Poly(N-isopropylacrylamide) (PNIPAAm) is known as a polymer contained in a photosensitive resin composition. PNIPAAm can be easily obtained by polymerizing N-isopropylacrylamide (NIPAAm) with a radical initiator. An aqueous solution of PNIPAAm undergoes phase separation due to temperature changes, dissolving in water at 31°C or lower, and becoming insoluble and precipitating at temperatures higher than that. A technology is known for manufacturing chips having dot patterns formed by photolithography using a photosensitive resin composition containing such a polymer. Photolithography technology, which processes substrates, etc., can manufacture fine pattern structures. Such fine pattern structures are useful when handling microscopic cells, etc.

In the examples of Patent Document 1, it is described that a cell culture support is produced by patterning using a photolithography method from a photosensitive resin composition containing a monomer N-isopropylacrylamide. However, in Patent Document 1, a cell culture support is produced on a glass substrate by performing post-exposure baking (PEB) for 20 hours in an oven at 80°C.
Patent Document 2 describes a coating material that exhibits cell selective culture and separation capabilities. However, Patent Document 2 describes that the polymer coating on the surface of the glass substrate is heated on a hot plate heated to 100° C. for 1 minute.
Non-Patent Document 1 describes a study in which a polymer of N-isopropylacrylamide, methacrylic acid, and 4-methacryloylbenzophenone is plasma cleaned, and then surface-adsorbed onto a glass substrate silanized with a hexamethyldisilazane solution (Scheme 1), to prepare a responsive hydrogel thin film, and then an atomic force microscope is used to examine the changes in structure and adhesion of the hydrogel thin film depending on temperature. However, in this study, the film is not cured, and the technique is applicable only to glass substrates.
Non-Patent Document 2 describes a study on the possibility of modeling the swelling behavior of a film produced from a copolymer of poly(N-isopropylacrylamide) and methacryloylbenzophenone, evaluating the swelling behavior of the film by neutron reflectometry, and measuring the film thickness with temperature change. However, the film is produced on a quartz or silicon substrate, and is heated at 90° C. for 10 minutes during the production of the film.

International Publication No. 2016/068271 International Publication No. 2019/013148

Langmuir 2010, 26(10), 7262-7269 Macromolecules 2008, 41(3), 919-924

Conventionally, when applying polymers to cell culture, a glass substrate was used instead of a plastic substrate because baking after light irradiation must be performed at high temperatures. However, when using a glass substrate for cell culture, the cured layer on the substrate is a thin film, so there is a problem that it is highly affected by alkaline elution of the glass substrate and it is difficult to achieve reproducibility. In addition, when trying to create a film on a silicon wafer instead of a plastic substrate, there are problems that the film does not become thick and the film thickness is not reproducible.
In addition, in current cell culture, plastic products have replaced glass products as the mainstream because they are easy to use, have excellent impact resistance, are inexpensive, are lightweight, etc. Therefore, it has been desired to use plastic substrates instead of glass and silicon wafer products for cell culture using polymers.

On the other hand, plastics have problems such as low heat resistance and dissolution in some organic solvents, etc. When using a plastic substrate for cell culture, it is required that the membrane or the like to be produced be prepared at room temperature or at most 50° C., and that the solvent of the composition to be the membrane be an organic solvent that does not dissolve plastics.
However, in the conventional technology, in order to cure a photosensitive resin composition containing N-isopropylacrylamide, it was necessary to maintain a high temperature of 80° C. or more for a certain period of time as a post-light irradiation bake. Therefore, it was extremely difficult to select an organic solvent that does not dissolve plastics, and to select and prepare a composition that dissolves in this organic solvent and cures only by light irradiation, to determine the wavelength and dose of light irradiation, and to establish a manufacturing method.
The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a photosensitive resin composition using a polymer that can produce a temperature-responsive pattern by photolithography in the field of cell culture. Another object of the present invention is to provide a photosensitive resin composition that can be processed at room temperature using a solvent that does not dissolve plastics, so that a plastic substrate can be used.

As a result of extensive research, the inventors discovered that it is possible to prepare a cured film by irradiating a composition containing N-isopropylacrylamide and an aryl ketone with light, and that a cured film that can be processed at room temperature without high-temperature baking can be produced by patterning using a photolithography method, thus completing the invention. Furthermore, they discovered that an organic solvent that does not dissolve plastics can be used as a solvent for the composition.

（式（１）中、Ｒ^１は、水素原子又は炭素原子数１～３のアルキル基を表し、
Ｒ^２は、置換されていてもよい炭素原子数１～１０のアルキル基を表す。）
第２観点として、前記アリールケトン（Ｂ）が、アセトフェノン、ベンゾフェノン、アントラキノン、アントロン、下記式（２）で表される化合物、式（２）で表される化合物のいずれかの環上炭素原子がヘテロ原子で置換されたアントロン類縁体、及びこれら化合物の誘導体からなる群から選択されるアリールケトンである、第１観点に記載の膜付きプラスチック基材に関する。

（式（２）中、 Ｒ^３乃至Ｒ^６は、それぞれ独立して、水素原子、炭素原子数１～１０のアルキル基、炭素原子数１～１０のアルコキシ基、ヒドロキシ基、スルホ基、ビニル基、アセトキシ基、ヒドロキシ基で置換されてもよい炭素原子数６～１４のアリール基、アミノ基又はモノ－若しくはジ－炭素原子数１～４のアルキルアミノ基を表し、
Ｘは－Ｏ－、－Ｓ－、＞ＣＨ_２、＞Ｃ＝Ｏ又は＞Ｎ－Ｒを表し、Ｒは水素原子、炭化水素基又はアシル基を表し、
ｎ１は、０又は１を表し、ｎ２乃至ｎ５は、それぞれ独立して０、１、２又は３を表わし、ｎ２＋ｎ３≦３、ｎ４＋ｎ５≦４を満たす。）
第３観点として、前記ポリマー（Ａ）が、下記式（３）で表される構造単位を有するポリマーである、第１観点に記載の膜付きプラスチック基材に関する。

（式（３）中、Ａｒは、式（４）、式（５）又は式（６）で示す基を表し、
Ｒ^１及びＲ^７は、水素原子又は炭素原子数１～３のアルキル基を表し、
Ｒ^２は、置換されていてもよい炭素原子数１～１０のアルキル基を表し、
Ｌは、２価の連結基を表し、
ｘ及びｙはそれぞれｘ＋ｙ≦１、０＜ｘ＜１、０＜ｙ＜１を満たす任意の数である。
式（４）乃至式（６）中、＊は、Ｌとの結合を表し、
Ｒ^３乃至Ｒ^６は、それぞれ独立して、水素原子、炭素原子数１～１０のアルキル基、炭素原子数１～１０のアルコキシ基、ヒドロキシ基、スルホ基、ビニル基、アセトキシ基、ヒドロキシ基で置換されてもよい炭素原子数６～１４のアリール基、アミノ基又はモノ－若しくはジ－炭素原子数１～４のアルキルアミノ基を表し、
Ｘは－Ｏ－、－Ｓ－、＞ＣＨ_２、＞Ｃ＝Ｏ又は＞Ｎ－Ｒを表し、Ｒは水素原子、炭化水素基又はアシル基を表し、
ｎ１は、０又は１を表し、ｎ２乃至ｎ５は、それぞれ独立して０、１、２又は３を表わし、ｎ２＋ｎ３≦３、ｎ４＋ｎ５≦４を満たす。）
第４観点として、前記式（３）において、０．０１≦ｙ／ｘ≦０．２を満たす、第３観点に記載の膜付きプラスチック基材に関する。
第５観点として、前記置換されていてもよいアリールケトン（Ｂ）が、分子量が５００以下である、第１観点に記載の膜付きプラスチック基材に関する。
第６観点として、前記膜（Ｃ）が、パターニングされた膜である、第１観点に記載の膜付きプラスチック基材に関する。
第７観点として、前記プラスチック基材が、ガラス転移温度が１０５℃以下であるプラスチック基材である、第１観点又は第６観点に記載の膜付きプラスチック基材に関する。
第８観点として、前記組成物とアルコール系溶剤とを含む溶液を前記プラスチック基材の表面に塗布して塗布膜を形成する工程（１）と、該塗布膜に光を照射する工程（２）と
を含む、膜付きプラスチック基材の製造方法に関する。
第９観点として、さらに光照射後に塗布膜を現像する工程（３）を含む、第８観点に記載の膜付きプラスチック基材の製造方法に関する。
第１０観点として、前記工程（２）の光の波長が１５０ｎｍ以上、６００ｎｍ以下である、第８観点又は第９観点に記載の膜付きプラスチック基材の製造方法に関する。 That is, the present invention relates to the following.
As a first aspect, there is provided a film-attached plastic substrate having a film (C) made of a photocured product of a composition on a surface of the plastic substrate,
The composition contains a polymer (A) having a structural unit represented by the following formula (1):
The composition may comprise an optionally substituted aryl ketone (B),
When the aryl ketone (B) is not included in the composition, the polymer (A) has a residue of the aryl ketone (B);
When the aryl ketone (B) is contained in the composition, the polymer (A) may have a residue of the aryl ketone (B).

In formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms;
^R2 represents an optionally substituted alkyl group having 1 to 10 carbon atoms.
As a second aspect, the present invention relates to a film-attached plastic substrate according to the first aspect, in which the aryl ketone (B) is an aryl ketone selected from the group consisting of acetophenone, benzophenone, anthraquinone, anthrone, a compound represented by the following formula (2), an anthrone analogue in which any carbon atom on the ring of the compound represented by formula (2) is substituted with a heteroatom, and derivatives of these compounds.

(In formula (2), R ³ to R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a hydroxy group, a sulfo group, a vinyl group, an acetoxy group, an aryl group having 6 to 14 carbon atoms which may be substituted with a hydroxy group, an amino group, or a mono- or di-alkylamino group having 1 to 4 carbon atoms;
X represents -O-, -S-, >CH ₂ , >C=O or >N-R, and R represents a hydrogen atom, a hydrocarbon group or an acyl group;
n1 represents 0 or 1, and n2 to n5 each independently represent 0, 1, 2, or 3, and n2 + n3 ≦ 3, n4 + n5 ≦ 4 are satisfied.
As a third aspect, the present invention relates to the film-attached plastic substrate according to the first aspect, in which the polymer (A) is a polymer having a structural unit represented by the following formula (3):

In formula (3), Ar represents a group represented by formula (4), formula (5), or formula (6),
R ¹ and R ⁷ each represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms;
^R2 represents an optionally substituted alkyl group having 1 to 10 carbon atoms;
L represents a divalent linking group;
x and y are arbitrary numbers satisfying x+y≦1, 0<x<1, and 0<y<1, respectively.
In formulas (4) to (6), * represents a bond to L.
^R3 to ^R6 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a hydroxy group, a sulfo group, a vinyl group, an acetoxy group, an aryl group having 6 to 14 carbon atoms which may be substituted with a hydroxy group, an amino group, or a mono- or di-alkylamino group having 1 to 4 carbon atoms;
X represents -O-, -S-, >CH ₂ , >C=O or >N-R, and R represents a hydrogen atom, a hydrocarbon group or an acyl group;
n1 represents 0 or 1, and n2 to n5 each independently represent 0, 1, 2, or 3, and n2 + n3 ≦ 3, n4 + n5 ≦ 4 are satisfied.
As a fourth aspect, the present invention relates to the film-attached plastic substrate according to the third aspect, in which, in formula (3), 0.01≦y/x≦0.2 is satisfied.
As a fifth aspect, the present invention relates to the film-attached plastic substrate according to the first aspect, in which the optionally substituted aryl ketone (B) has a molecular weight of 500 or less.
As a sixth aspect, the present invention relates to the film-attached plastic substrate according to the first aspect, in which the film (C) is a patterned film.
As a seventh aspect, the present invention relates to the film-attached plastic substrate according to the first aspect or the sixth aspect, in which the plastic substrate has a glass transition temperature of 105° C. or lower.
As an eighth aspect, the present invention relates to a method for producing a film-coated plastic substrate, the method including: a step (1) of applying a solution containing the composition and an alcohol-based solvent to a surface of the plastic substrate to form a coating film; and a step (2) of irradiating the coating film with light.
As a ninth aspect, the present invention relates to the method for producing a film-coated plastic substrate according to the eighth aspect, further comprising a step (3) of developing the coating film after the light irradiation.
As a tenth aspect, the present invention relates to the method for producing a film-coated plastic substrate according to the eighth or ninth aspect, in which the wavelength of the light in the step (2) is 150 nm or more and 600 nm or less.

According to the present invention, it is possible to provide a film-coated plastic substrate, which has a film made of a photocured product on the surface of the plastic substrate at room temperature, using a photosensitive resin composition, without high-temperature baking after light irradiation.
According to the present invention, a plastic substrate having a film made of a photocured product attached to the surface of the plastic substrate having a glass transition temperature of 105° C. or lower can be provided using a photosensitive resin composition.
According to the present invention, by using an alcohol-based solvent, a plastic substrate with a film made of a photocured material can be produced without dissolving the plastic.
According to the present invention, by using a photosensitive resin composition, a method for producing a film-coated plastic substrate made of a photocured product by a simple photolithography method without baking after light irradiation can be provided.

FIG. 1 is a graph showing the sensitivity behavior of the photosensitive resin compositions obtained in Example 1, Example 2 and Comparative Example 1 on a polystyrene film. FIG. 2 is a graph showing the sensitivity behavior on a silicon wafer of the photosensitive resin compositions obtained in Example 1, Example 2 and Comparative Example 1. FIG. 3 is an electron microscope photograph of patterning on a polystyrene film using the photosensitive resin composition obtained in Example 1. FIG. 4 is a differential thermal curve of the reaction product obtained in Synthesis Example 1 in pure water. FIG. 5 is a differential thermal curve of the reaction product obtained in Synthesis Example 2 in pure water. FIG. 6 is a differential thermal curve of the reaction product obtained in Synthesis Example 1 in phosphate buffered saline. FIG. 7 is a differential thermal curve of the reaction product obtained in Synthesis Example 2 in phosphate buffered saline. FIG. 8 shows the change in film thickness of a photocured film prepared using composition 2 as a function of temperature. Figures 9a to 9d are photographs of films of Composition 3 with thicknesses of 5 to 10 nm, which were cultured and then placed on a stand at temperatures ranging from 37°C to 22°C, taken at times ranging from 0 to 10 minutes (Figure 9a: optical microscope photograph after 0 minutes, Figure 9b: optical microscope photograph after 5 minutes, Figure 9c: overall photograph after 7 minutes, Figure 9d: overall photograph after 10 minutes). 10a and 10b are photographs of films of Composition 3 having a thickness of 11-22 nm, which were subsequently cultured at 37° C. (FIG. 10a: optical microscope photograph, FIG. 10b: overall photograph).

<Photosensitive resin composition>
The photosensitive resin composition (hereinafter, also referred to as the composition) of the present invention will be described.
The composition contains a polymer (A) having a structural unit represented by formula (1),
The composition may comprise an optionally substituted aryl ketone (B),
When the aryl ketone (B) is not included in the composition, the polymer (A) has a residue of the aryl ketone (B);
When the aryl ketone (B) is contained in the composition, the polymer (A) may have a residue of the aryl ketone (B).
Therefore, the photosensitive resin composition of the present invention is
"(Composition I) A polymer (A) containing a structural unit (main chain 1) represented by the above formula (1) and a structural unit (main chain 2) having a residue of an aryl ketone (B) bonded thereto. (Composition II) A photosensitive resin composition comprising a structural unit (main chain 1) represented by the above formula (1) and a structural unit (main chain 2) to which a residue of an aryl ketone (B) can be bonded but is not bonded. A photosensitive resin composition comprising a polymer (A) containing a chain 2) and an optionally substituted aryl ketone (B);
(Composition III) A structural unit (main chain 1) represented by the above formula (1), a structural unit (main chain 2) to which a residue of an aryl ketone (B) is bonded, and a structural unit (main chain 3) to which a residue of an aryl ketone (B) is bonded. A photosensitive resin composition comprising a polymer (A) having a structural unit (main chain 2) to which a group can be bonded but which is not bonded, and further comprising an optionally substituted aryl ketone (B) bonded to the main chain 2. However, in the above (Composition I) to (Composition III), the main chain 2 may be a derivative group of the main chain 1.

（式（７）中、Ｒ^７は、水素原子又は炭素原子数１～３のアルキル基を表し、
Ｌ^１は、アリールケトン（Ｂ）と反応して結合する基を表す。） <Polymer (A)>
The polymer (A) can contain a structural unit (main chain 1) represented by the above formula (1), a structural unit (main chain 2) to which a residue of an aryl ketone (B) is bonded, and a structural unit (main chain 2) to which a residue of an aryl ketone (B) can be bonded but is not bonded.
The main chain 1 is also called the first monomer unit and is represented by the above formula (1).
The main chain 2 is also referred to as the second monomer unit, and may have a residue of an aryl ketone (B) bonded thereto or may not have a residue of an aryl ketone (B) bonded thereto.
A specific example of a compound having a residue of an aryl ketone (B) bonded thereto is shown on the right side of the above formula (3).
A specific example of a case where the residue of aryl ketone (B) can be bonded but is not bonded is the following formula (7).

(In formula (7), R ⁷ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms;
^L1 represents a group that reacts with and bonds to the aryl ketone (B).

<Aryl ketone (B)>
An "aryl ketone (B)" is a compound containing an aryl group and a carbonyl group.
As the aryl ketone of the present invention, benzophenone or a substituted derivative thereof (hereinafter also referred to as a "benzophenone compound") is preferred from the viewpoint that the lifetime of the lowest excited triplet is relatively long and photochemical reactions are easily caused.
Examples of the benzophenone compound include 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2',3,4-tetrahydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'3,4,4'-pentahydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,3,3'4,4',5'-hexahydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,3, 4-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,4,5-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,4-dihydroxy-4'-diethylaminobenzophenone, 2,4-dihydroxy-4'-dimethylaminobenzophenone, 2,4-dihydroxybenzophenone, 4,4'-dihydroxybenzophenone, 2-hydroxy-4-(2-hydroxy-3-methacryloxy)propoxybenzophenone, 2-hydroxy-4'-dimethylaminobenzo phenone, 2-hydroxy-4-i-octyloxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-acetoxyethoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxydisulfobenzophenone disodium, 2-hydroxy Examples of the benzophenone include 4-hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxybenzophenone, 4,4'-dihydroxybenzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, 4',6-dihydroxy-2-naphthobenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 4-hydroxybenzophenone, N,N,N',N'-tetramethyl-4,4'-diaminobenzophenone, etc. Optionally substituted vinyl benzophenones are also included.
Other examples of structures capable of abstracting hydrogen radicals upon irradiation with ultraviolet light include a benzyl group, an o-benzoylbenzoate group, a thioxanthone group, a 3-ketocoumarin group, a 2-ethylanthraquinone group, and a camphorquinone group. Compounds having these structures may also be used.
In addition to the benzophenone compounds, specific preferred examples of the aryl ketones include aryl ketones selected from the group consisting of acetophenone, benzophenone, anthraquinone, anthrone, the compound represented by the above formula (2), anthrone analogues in which any carbon atom of the compound represented by formula (2) is substituted with a heteroatom, and derivatives of these compounds.

<Optionally Substituted Aryl Ketone (B)>
Examples of the substituent that the "optionally substituted aryl ketone (B)" may have include a halogen atom, an amino group, a mono- or di-alkylamino group having 1 to 4 carbon atoms, a nitro group, a cyano group, an oxo group, a hydroxy group, a sulfanyl group, an alkoxy group having 1 to 4 carbon atoms, an alkoxycarbonyl group having 1 to 4 carbon atoms, a formyl group, and an aryl group having 6 to 14 carbon atoms.
The aforementioned "halogen atom" includes fluorine, chlorine, bromine and iodine.
Examples of the "mono- or di-alkylamino group having 1 to 4 carbon atoms" include a methylamino group, an ethylamino group, a propylamino group, an isopropylamino group, a butylamino group, a dimethylamino group, a diethylamino group, a dipropylamino group, a dibutylamino group, and an n-ethyl-n-methylamino group.

The "alkoxy group" may be either linear or branched. Examples of the "alkoxy group having 1 to 4 carbon atoms" include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, and a tert-butoxy group.
The "alkoxycarbonyl group having 1 to 4 carbon atoms" is an organic group in which a carbonyl group -C(=O)- is bonded to the "alkoxy group having 1 to 4 carbon atoms".
Examples of the "aryl group having 6 to 14 carbon atoms" include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, a 2-anthryl group, and a 9-anthryl group.

<Anthrone Analogues in Which Any Carbon Atom of the Compound Represented by Formula (2) is Substituted with a Heteroatom>
The term "anthrone analog" refers to another compound having a composition in which an atom or atomic group of anthrone is replaced with another heteroatom. The "anthrone analog" of the present invention refers to "an anthrone analog in which any carbon atom of the compound represented by formula (2) is replaced with a heteroatom."
Heteroatoms include nitrogen, oxygen, sulfur, phosphorus, chlorine, iodine, bromine, and the like.
Derivatives of these compounds
The above-mentioned "these compounds" refer to acetophenone, benzophenone, anthraquinone, anthrone, the compound represented by the above formula (2), and anthrone analogues in which any carbon atom of the compound represented by formula (2) is substituted with a heteroatom.
The term "derivatives of these compounds" refers to the substitution of an atom or an atomic group of the aforementioned "these compounds" with another substituent. The substituent that can be substituted is the same as the substituent shown in the aforementioned <Optionally substituted aryl ketone (B)>.

<Molecular weight of aryl ketone (B)>
The "optionally substituted aryl ketone" may have a molecular weight of 500 or more. However, in consideration of ease of handling of the composition and ease of curing of the film, the molecular weight is preferably 500 or less, more preferably 400 or less, and even more preferably 300 or less.

<Residue of aryl ketone (B)>
The residue of an aryl ketone is a group of a compound (monoaryl ketone or diaryl ketone) in which one or two aryl groups are directly bonded to a carbonyl group [-C(=O)-], an ether group [-O-], an alkylene group, or the like. This residue of an aryl ketone acts as a photoreactive group and can be activated by light of a specific wavelength, such as ultraviolet light, to cause a crosslinking reaction.
As used herein, the term "residue" of a compound refers to an organic group in which a hydrogen atom bonded to a carbon atom or heteroatom (such as a nitrogen, oxygen, or sulfur atom) constituting the compound is replaced with a bond for covalent bonding.
The residue of the aryl ketone does not constitute the main chain, but constitutes a side chain of the polymer that is one embodiment of the present invention, via a suitable linking group.
As used herein, the term "backbone" refers to the longest series of covalently bonded atoms that together form a continuous chain of a molecule.
The term "side chain" is used herein to broadly encompass chemical groups that are covalently attached to a main chain and pendant laterally, and is used synonymously with so-called pendant molecular chains.
Examples of the residue of an aryl ketone include the monovalent groups of the optionally substituted aryl ketones shown above as the optionally substituted aryl ketones (B).
These aryl ketone residues (monovalent groups) form covalent bonds such as an —O— bond, an ester bond (—O—CO— or —CO—O—), an amide bond (—NH—CO— or —CO—NH—), a urethane bond (—NH—CO—O— or —O—CO—NH—), a carbonate bond (—O—CO—O—), or a urea bond (—NH—CO—NH—), between themselves and a group in the polymer to which they are bonded (for example, included in L in Formula (3)), thereby forming a side chain of the polymer.
Therefore, "L" in the formula (3) is the bonding group or a group in which the bonding group is bonded to one or more groups selected from an alkylene group having 1 to 3 carbon atoms, an alkenylene group having 1 to 3 carbon atoms, and a carbonyl group.
Furthermore, "L ¹ " in the above formula (4) is a group in which a hydrogen atom is bonded in place of the aryl ketone bonded to the above "L".
The "alkylene group having 1 to 3 carbon atoms" includes a divalent group having a straight chain or a branched chain, such as a methylene group, an ethylene group, or a propylene group.
The "alkenylene group having 1 to 3 carbon atoms" refers to a divalent group having a double bond and a straight or branched chain, and one or more carbon-carbon bonds of the alkylene group having 1 to 3 carbon atoms are double bonds.

R ¹ in the formula (1) includes an alkyl group having 1 to 3 carbon atoms.
The above-mentioned "alkyl group having 1 to 3 carbon atoms" includes straight-chain or branched-chain alkyl groups, such as a methyl group, an ethyl group, an n-propyl group, and an isopropyl group.

^R2 in formula (1) represents an optionally substituted alkyl group having 1 to 10 carbon atoms.
The "alkyl group having 1 to 10 carbon atoms" includes those having a straight chain or a branched chain, such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a 1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n-propyl group, a 1-ethyl-n-propyl group, an n-hexyl group, a 1-methyl-n-pentyl group, a 2 ... Examples of such alkyl groups include butyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2-dimethyl-n-butyl, 1,3-dimethyl-n-butyl, 2,2-dimethyl-n-butyl, 2,3-dimethyl-n-butyl, 3,3-dimethyl-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, 1,2,2-trimethyl-n-propyl, 1-ethyl-1-methyl-n-propyl and 1-ethyl-2-methyl-n-propyl groups.

Examples of the substituents that the "optionally substituted alkyl group having 1 to 10 carbon atoms" may have include halogen atoms, amino groups, mono- or di-alkylamino groups having 1 to 4 carbon atoms, nitro groups, cyano groups, oxo groups, hydroxy groups, sulfanyl groups, alkoxy groups having 1 to 4 carbon atoms, alkoxycarbonyl groups having 1 to 4 carbon atoms, formyl groups, and aryl groups having 6 to 14 carbon atoms.

The "alkyl group having 1 to 10 carbon atoms" and the "aryl group having 6 to 14 carbon atoms" shown in formula (2) are the same as those described above.
The "alkoxy group having 1 to 10 carbon atoms" shown in formula (2) represents a group in which the "alkyl group having 1 to 10 carbon atoms" is bonded to --O--.
The “aryl group having 6 to 14 carbon atoms which may be substituted with a hydroxy group” shown in formula (2) represents a group in which a hydroxy group is bonded in place of any hydrogen atom of the “aryl group having 6 to 14 carbon atoms”.
The "hydrocarbon group" in formula (2) refers to an alkyl group, an alkenyl group, or an aryl group.
The "acyl group" shown in formula (2) represents R ¹¹ -C(=O)-, where "R ¹¹ " represents a hydrogen atom, an alkyl group, an alkenyl group, or an aryl group.

The "alkyl group having 1 to 3 carbon atoms" and the "alkyl group having 1 to 10 carbon atoms which may be substituted" shown in formula (3) are the same as those shown in formula (1). Furthermore, when there is a description of an "alkyl group having 1 to 3 carbon atoms", an "alkyl group having 1 to 10 carbon atoms which may be substituted" or "optionally substituted" below, the same as the above unless otherwise specified.
The "R ³ to R ⁶ , X, and n1 to n5" in the formulas (4) to (6) are the same as those in the formula (2).

In formula (3), x and y are arbitrary numbers that satisfy x+y≦1, 0<x<1, and 0<y<1, and x and y are the molar ratios of the constituent units. Furthermore, x and y can satisfy 0.01≦y/x≦0.2, preferably 0.02≦y/x≦0.18, and more preferably 0.03≦y/x≦0.15.
For example, "0.03≦y/x≦0.15" means that y is the number of moles of x.
is 3 mol% to 15 mol%. This indicates that 3 mol% to 15 mol% of the right-side structural unit is sufficient for the left-side structural unit represented by formula (3). In other words, the left-side structural unit of formula (3) is important as a polymer, but the right-side structural unit of formula (3) is necessary to promote crosslinking by light. In the present invention, the thickness and degree of cure of the film can be adjusted by the exposure dose and this ratio of x:y, so this ratio of x:y is an important index.
Furthermore, "x+y≦1" can also be "x+y=1" or "x+y<1". When "x+y=1", the polymer is composed only of the left and right structural units shown in formula (3). When "x+y<1", the polymer contains other polymer structural units in addition to the polymer structural units shown on the right and left sides of formula (3).

<Alcohol-based solvent>
The "alcohol-based solvent" used in the present invention is an alcohol having 2 to 10 carbon atoms which may be substituted.
The "alcohol having 2 to 10 carbon atoms" may be linear or branched. Specific examples include ethanol, 1-propanol, 2-propanol, 1-butanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-2-butanol, 2-ethyl-1-butanol, 2,3-dimethyl-2-butanol, 2-methyl-2-pentanol, 4-methyl-2-pentanol, tert-pentyl alcohol, propylene glycol monopropyl ether, tert-butyl cellosolve, cyclohexanol, 4-tert-butylhexanol, α-terpineol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diethylene glycol mono-tert-butyl ether, and diacetone alcohol.

The substituent that the "alcohol having 2 to 10 carbon atoms which may be substituted" may have is the same as the substituent that the "alkyl group having 1 to 10 carbon atoms which may be substituted" may have. In particular, when the substituent is a hydroxyl group, the alcohol becomes a polyhydric alcohol. Examples of the polyhydric alcohol include dihydric polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, pentanediol, dimethylbutanediol, hexanediol, octanediol, and decanediol, and trihydric or higher polyhydric alcohols such as glycerin, pentaerythritol, and trimethylolpropane. The present invention is not limited to only these examples. These alcohols may be used alone or in combination of two or more kinds.
In the present invention, the content of the alcohol-based solvent is preferably 50 to 99.5 parts by mass, more preferably 55 to 95 parts by mass or 60 to 90 parts by mass, and even more preferably 60 to 80 parts by mass, relative to 100 parts by mass of the total mass of the photosensitive resin composition, in order to control the film thickness and to obtain good patterning characteristics.

<Crosslinking Agent>
The photosensitive resin composition of the present invention may contain a crosslinking agent within the range not impairing the effects of the present invention. Examples of the crosslinking agent include glycoluril compounds, melamine compounds, and bisazide compounds.
Examples of glycoluril compounds include 1,3,4,6-tetrakis(methoxymethyl)glycoluril, 1,3,4,6-tetrakis(ethoxymethyl)glycoluril, 1,3,4,6-tetrakis(propoxymethyl)glycoluril, and 1,3,4,6-tetrakis(butoxymethyl)glycoluril.
Examples of the melamine compound include hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropoxymethylmelamine, and hexabutoxymethylmelamine.
When a crosslinking agent is used, in order to obtain good patterning characteristics and sufficient temperature responsiveness, the content thereof is preferably usually 50 parts by mass or less, 30 parts by mass or less, or even 10 parts by mass or less, relative to 100 parts by mass of the total mass of the polymer (A) (resin component).

<Other additives>
The photosensitive resin composition of the present invention may contain other additives commonly used in the art, as long as the effects of the present invention are not impaired. Examples of the other additives include antireflection agents, polymerization initiators, ultraviolet absorbers, antioxidants, light stabilizers, sensitizers, surfactants, leveling agents, and silane coupling agents.
When other additives are used, it is usually preferable that the total amount of the other additives is 30 parts by mass or less, 20 parts by mass or less, 10 parts by mass or less, or even 5 parts by mass or less per 100 parts by mass of the total mass of the polymer (A) (resin component).

<Synthesis of Polymer (A)>
In the case of (Composition I), a predetermined amount of a monomer having a structural unit represented by the above formula (1) (e.g., N-isopropylacrylamide) and a predetermined amount of a monomer having a structural unit to which a residue of an aryl ketone (B) is bonded (e.g., 4-benzoylphenyl methacrylate);
In the case of (Composition II), a predetermined amount of a monomer having a structural unit represented by the above formula (1) (e.g., N-isopropylacrylamide) and a predetermined amount of a monomer having a structural unit to which a residue of an aryl ketone (B) can be bonded but is not bonded (e.g., methacrylic acid);
In the case of (Composition III), a predetermined amount of a monomer having a structural unit represented by the above formula (1) (e.g., N-isopropylacrylamide), a predetermined amount of a monomer having a structural unit to which a residue of an aryl ketone (B) is bonded (e.g., 4-benzoylphenyl methacrylate), and a predetermined amount of a monomer having a structural unit to which a residue of an aryl ketone (B) can be bonded but is not bonded (e.g., methacrylic acid) are dissolved in an alcohol-based solvent, and the temperature is raised to, for example, 50 to 80° C. or higher, and a crosslinking agent and other additives are added if necessary, and the reaction is carried out at 50 to 80° C. for 12 hours or more, thereby obtaining a solution of polymer (A).
The weight average molecular weight (mw) of the obtained polymer in terms of standard polystyrene is preferably 10,000 or more, more preferably 20,000 or more, 30,000 or more, 40,000 or more, or 50,000 or more, since a low value leads to a low sensitivity of temperature response, and is preferably 300,000 or less, more preferably 200,000 or less, 150,000 or less, 100,000 or less, 90,000 or less, or 80,000 or less, since a high value is likely to lead to a low solubility or resolution. The mw value in the present invention is measured by gel permeation chromatography (GPC).

<Content of Polymer (A)>
In order to achieve good patterning characteristics, the polymer content may be 50 to 99 parts by mass, 60 to 98 parts by mass, or even 70 to 97 parts by mass or less, relative to 100 parts by mass of the total mass of the solid content of the photosensitive resin composition excluding the alcohol-based solvent.

<Plastic substrate>
Examples of materials for the plastic substrate include resins (plastics).
The resin may be any of natural resin, modified natural resin, and synthetic resin. Examples of natural resins include cellulose. Examples of modified natural resins include cellulose triacetate and cellulose immobilized with dextran sulfate. Examples of synthetic resins include polyethylene, polypropylene, polyvinyl chloride, polystyrene, ABS, polyamide 6, polyamide 66, polyurethane, polylactic acid, polyacrylonitrile, polyvinylidene fluoride, polybutylene terephthalate, polyethylene terephthalate, polyvinyl acetate, polybutyl acrylate, polyethyl acrylate, polymethyl acrylate, polymethyl methacrylate, polyester polymer alloy, polyvinyl alcohol, polyester, and polyethersulfone.

The plastic substrate used in the present invention may be a plastic having a glass transition temperature of 105°C or less. In particular, examples of "plastics having a glass transition temperature of 105°C or less" include polyethylene, polypropylene, polyvinyl chloride, polystyrene, ABS, polyamide 6, polyamide 66, polylactic acid, polyacrylonitrile, polyvinylidene fluoride, polybutylene terephthalate, polyethylene terephthalate, polyvinyl acetate, polybutyl acrylate, polyethyl acrylate, polymethyl acrylate, polymethyl methacrylate, etc. Among these plastics, polystyrene is preferred.

<Method for producing film (C) made of photocured product of composition and film-attached plastic substrate>
The present invention provides a film (C) made of a photocured product of the photosensitive resin composition of the polymer (A), a plastic substrate with a film, a patterned plastic substrate with a film, and a method for producing the same. The film (C) made of a photocured product of the photosensitive resin composition of the polymer (A) is patterned to form a patterned film and the plastic substrate with a film. The film (C), the plastic substrate with a film, and the patterned plastic substrate with a film can be produced, for example, by the method described below.
Step (1): A step of forming a film by applying a solution containing the composition and an alcohol-based solvent to the surface of the plastic substrate The photosensitive resin composition containing the polymer (A) of the present invention is dissolved in the alcohol-based solvent to obtain a solution containing the polymer (A) and an alcohol-based solvent. This solution is applied to the plastic substrate by a method such as spin coating or slit coating, and the solvent is removed to form a film.
Step (2): Step of irradiating the film with light When light of a certain wavelength is irradiated through a mask using an aligner to obtain a desired pattern, photocuring occurs only in the light irradiated portions.
Step (3): Step of developing the film after light irradiation The film after light irradiation is developed with a developer or the like, and the part not irradiated with light (the uncured part of the coating film) is removed. These steps can produce a patterned film-attached plastic substrate. Note that, regardless of whether or not the film is patterned, the process after coating the film on the plastic substrate is all referred to as a "film-attached plastic substrate". Therefore, the patterned film-attached plastic substrate is included in the film-attached plastic substrate.
According to the above-mentioned production method, a film made of a photocured product of the photosensitive resin composition of the polymer (A), a plastic substrate with a film, and a patterned plastic substrate with a film can be produced.

In "step (2): step of irradiating the film with light" of the production method of the present invention, the amount of exposure is adjusted according to the required film thickness and rate of curing.
The light to be irradiated is preferably ultraviolet light or visible light of 600 nm or less, more preferably ultraviolet light. The wavelength is preferably 150 nm or more and 600 nm or less, more preferably 150 nm or more and 500 nm or less, and even more preferably 200 nm or more and 380 nm or less. The exposure dose is preferably 10 to 5,000 mj/cm ² , more preferably 50 to 3,000 mj/cm ² , and even more preferably 100 to 2,000 mj/cm ² .
The above-described production method of the present invention can provide a film made of a photocured product of a photosensitive resin composition as a temperature-responsive film having a desired response temperature, a plastic substrate with said film, and a patterned plastic substrate with a film.
Furthermore, the film of the film-attached plastic substrate and the patterned film-attached plastic substrate of the present invention may be present not only on one side of the plastic substrate but also on both sides.

<Patterning Shape>
There is no particular limit to the shape of the pattern formed in the patterned film, and examples of the shape include a square, a circle, a line, and a line and space when observed from above the substrate. There is no particular limit to the size of the pattern observed from above and the thickness (height) observed from the cross section of the pattern. The size of one side of the pattern is, for example, 0.1 μm to 1,000 mm, and the thickness (height) of the pattern is, for example, 5 nm to 1,000 μm. The shapes of these patterns can be controlled by using multiple masks with different shapes of transmitted light during light irradiation.

<Cell culture support and method for producing same>
The cell culture support of the present invention is a film made of a photocured film of a photosensitive resin composition containing a polymer, or a film which has been further patterned. The present invention also provides the cell culture support and a method for producing the same.
The method for producing a cell culture support in the present invention is the same as the above-mentioned <Method for producing a film and a film-attached plastic substrate> using a photosensitive resin composition containing a polymer. The method is characterized by including a step of forming a coating film on a plastic substrate and irradiating the coating film with light to form a film made of a cured product or a further patterned film. The photosensitive resin composition does not contain an acid generator, and it is preferable that high-temperature baking is not performed after light irradiation. The photosensitive resin composition may also contain a crosslinking agent or other additives.
The thickness (height) of the membrane as a cell culture support is preferably 1 to 100 nm, more preferably 2 to 50 nm, and even more preferably 3 to 30 nm, so that cells are attached to the membrane during culture and the cultured cells are detached from the membrane by changing the temperature of the culture system when the cultured cells are recovered. There is no particular limitation on the size of the membrane observed from above, and the size of one side of the cured material layer is, for example, 0.1 to 1,000 mm.

<Lower critical point temperature>
In the present invention, the cell culture support has a lower critical solution temperature (LCST) in order to attach cells to the membrane during culture and to detach the cultured cells from the membrane by changing the temperature of the culture system when the cultured cells are recovered. The lower critical solution temperature is the temperature at which a solution separates into two phases at a certain temperature or higher. In other words, in a system having a lower critical solution temperature, it is said that multiple components exist in one phase regardless of composition at temperatures below that temperature.
The lower critical point temperature (LCST) value was determined by dissolving a polymer solution in phosphate buffered saline (Sigma-Aldrich) at a concentration of 2 wt %. Under a nitrogen atmosphere, the temperature of the aqueous solution was lowered at 1° C./min, while measuring the differential heat in air using a differential scanning calorimetry (DSC) (DSC7020, SII Nano Technology Co., Ltd.), and the temperature showing the peak top of the measurement curve was calculated as the lower critical point temperature (LCST) of the polymer.
The cell culture support of the present invention can be manufactured by changing the constituent units of the temperature-responsive polymer, so that the cell culture support has a lower critical temperature (LCST) of 15° C. or more and less than 45° C. The cell culture support is a photosensitive resin composition using a temperature-responsive polymer containing two or more kinds of constituent units having different temperature responsiveness, and may have a pattern with two or more kinds of response temperatures. The cell culture support of the present invention can be any of the above cell culture supports.

<Cell culture method on cell culture support, etc.>
In the present invention, the method and conditions for culturing cells on the cell culture support are not particularly limited, and cells can be cultured by a method known per se.
The cell culture method uses the above-mentioned membrane-attached plastic substrate, and involves seeding cells on the cell culture support, which is a membrane, and culturing the cells by incubating the cells at a temperature suitable for culture and higher than the lower critical point temperature of the cell culture support. Thereafter, the temperature of the hardened material layer is adjusted to a temperature lower than the lower critical point temperature of the polymer, thereby detaching the cells from the cell culture support and recovering the cells.

In the present invention, the cells are not particularly limited, and various cells can be cultured. Examples of the cells include epithelial cells and endothelial cells that constitute various tissues and organs in the body, skeletal muscle cells, smooth muscle cells, and cardiac muscle cells that exhibit contractility, neurons and glial cells that constitute the nervous system, fibroblasts, hepatic parenchymal cells, non-hepatic parenchymal cells, and adipocytes that are involved in metabolism in the body, stem cells present in various tissues, as well as bone marrow cells and ES cells.
In the present invention, the method for seeding cells or the method for recovering cultured cells detached from the cell culture support are not particularly limited, and any method known per se can be used.

The present invention will be explained in more detail below with reference to examples. However, the present invention is not limited to the following examples, and it is of course possible to carry out the invention with appropriate modifications within the scope of the above and below aims, and all such modifications are included in the technical scope of the present invention.

<a. Polymer and Monomer Synthesis>
<Synthesis Example 1>
10 g of N-isopropylacrylamide and 0.73 g of 4-benzoylphenyl methacrylate were dissolved in 25.3 g of 1-propanol, and the temperature was raised to 70° C. Thereafter, 0.11 g of azobisisobutyronitrile was added while maintaining the reaction solution at 70° C., and the mixture was reacted at 70° C. for 24 hours to obtain a solution of a copolymerized polymer compound of N-isopropylacrylamide and 4-benzoylphenyl methacrylate. When the obtained copolymerized polymer compound was subjected to GPC analysis, the weight average molecular weight was 75,600 in terms of standard polystyrene.

＜合成例３＞
Ｎ－イソプロピルアクリルアミド２５ｇとメタクリル酸４－ベンゾイルフェニル０．３ｇを１－プロパノール５９．６ｇに溶解させた後、７０℃まで昇温させた。その後、反応液を７０℃に保ちながらアゾビスイソブチロニトリル０．２５ｇを添加し、７０℃で２４時間反応させＮ－イソプロピルアクリルアミドとメタクリル酸４－ベンゾイルフェニルの共重合高分子化合物の溶液を得た。得られた共重合高分子化合物のＧＰＣ分析を行ったところ、標準ポリスチレン換算にて重量平均分子量は４４２００であった。

<Synthesis Example 2>
10 g of N-isopropylacrylamide and 0.24 g of 4-benzoylphenyl methacrylate were dissolved in 24.1 g of 1-propanol, and the temperature was raised to 70° C. Thereafter, 0.10 g of azobisisobutyronitrile was added while maintaining the reaction solution at 70° C., and the mixture was reacted at 70° C. for 24 hours to obtain a solution of a copolymerized polymer compound of N-isopropylacrylamide and 4-benzoylphenyl methacrylate. When the obtained copolymerized polymer compound was subjected to GPC analysis, the weight average molecular weight was 57,700 in terms of standard polystyrene.

<Synthesis Example 3>
25 g of N-isopropylacrylamide and 0.3 g of 4-benzoylphenyl methacrylate were dissolved in 59.6 g of 1-propanol, and the temperature was raised to 70° C. Thereafter, 0.25 g of azobisisobutyronitrile was added while maintaining the reaction solution at 70° C., and the mixture was reacted at 70° C. for 24 hours to obtain a solution of a copolymerized polymer compound of N-isopropylacrylamide and 4-benzoylphenyl methacrylate. When the obtained copolymerized polymer compound was subjected to GPC analysis, the weight average molecular weight was 44,200 in terms of standard polystyrene.

Comparative Synthesis Example 1
20 g of N-isopropylacrylamide was dissolved in 47.6 g of 1-propanol, and the temperature was raised to 75° C. Thereafter, 0.4 g of azobisisobutyronitrile was added while maintaining the reaction solution at 75° C., and the mixture was reacted at 75° C. for 24 hours to obtain a solution of an N-isopropylacrylamide polymer compound. When the obtained copolymer polymer compound was subjected to GPC analysis, the weight average molecular weight was 30,800 in terms of standard polystyrene.

Comparative Synthesis Example 2
20 g of N-isopropylacrylamide and 5.13 g of 2-hydroxyethyl acrylate were dissolved in 101.5 g of 1-propanol, and the temperature was raised to 80° C. Thereafter, 0.25 g of azobisisobutyronitrile was added while maintaining the reaction solution at 80° C., and the mixture was reacted at 80° C. for 24 hours to obtain a solution of a copolymerized polymer compound of N-isopropylacrylamide and 2-hydroxyethyl acrylate. When the obtained copolymerized polymer compound was subjected to GPC analysis, the weight average molecular weight was 23,000 in terms of standard polystyrene.

<b. Preparation of Composition>
<Compositions 1 and 2>
16.7 g of 1-propanol was added to 3.3 g of a solution containing 1.0 g of the reaction product obtained in Synthesis Examples 1 and 2, and the mixture was filtered using a polyethylene microfilter having a pore size of 0.10 μm to prepare a photocurable resin composition solution.

<Composition 3>
33.5 g of 1-propanol was added to 1.0 g of a solution containing 0.3 g of the reaction product obtained in Synthesis Example 3, and the mixture was filtered using a polyethylene microfilter having a pore size of 0.10 μm to prepare a photocurable resin composition solution.

<Composition 4>
41.9 g of 1-propanol was added to 2.0 g of a solution containing 0.6 g of the reaction product obtained in Synthesis Example 3, and the mixture was filtered using a polyethylene microfilter having a pore size of 0.10 μm to prepare a photocurable resin composition solution.

<Comparative Composition 1>
16.7 g of 1-propanol was added to 3.3 g of a solution containing 1.0 g of the reaction product obtained in Comparative Synthesis Example 1, and the mixture was filtered using a polyethylene microfilter having a pore size of 0.10 μm to prepare a photocurable resin composition solution.

<Comparative Composition 2>
To 10 g of a solution containing 2 g of the reaction product obtained in Comparative Synthesis Example 2, 0.1 g of α-(methylsulfonyloxyimino)-4-methoxybenzyl cyanide (product name: PAI-1001, manufactured by Midori Chemical Co., Ltd.), 0.03 g of 1,3,4,6-tetrakis(methoxymethyl)glycoluril, and 0.52 g of 1-propanol were added, and the mixture was filtered using a polyethylene microfilter having a pore size of 1.0 μm to prepare a photocurable resin composition solution.

<c. Preparation of plastic substrate (polystyrene film)>
A polystyrene petri dish (35 mm non-treated dish manufactured by IWAKI) was dissolved in propylene glycol monomethyl ether acetate and filtered using a polyethylene microfilter with a pore size of 1.0 μm to prepare a 3.5 wt% polystyrene solution. The solution was applied onto a silicon wafer substrate using a spinner. The substrate was baked on a hot plate at 180° C. for 1 minute to form a coating film with a thickness of 100 nm.
The resulting film was exposed to 1-propanol for 1 minute, spin-dried, and baked at 100° C. for 1 minute. The film thickness was measured and found to be 100 nm, indicating that the film was resistant to exposure to 1-propanol.

<d. Sensitivity Measurement>
The photocurable resin composition solutions prepared from compositions 1-2 and comparative composition 1 were applied by a spinner onto a silicon wafer and the polystyrene film prepared in c. The resulting film was baked on a hot plate at 50°C for 1 minute to form a coating film having a thickness of 330 nm. (The coating films made from compositions 1-2 were designated as Examples 1-2, and the coating film made from comparative composition 1 was designated as Comparative Example 1.) After irradiation with 254 nm light at different exposure doses using an aligner, the remaining film thickness was measured after development with 1-propanol.
In Examples 1 and 2, the residual film thickness was not stable for each exposure dose on the silicon wafer, but it was stable on the polystyrene film and showed good sensitivity behavior with a high residual film rate. Comparative Example 1, which does not have a benzophenone structure, showed no residual film.
Comparative composition 2 was applied onto a polystyrene substrate. It was baked on a hot plate at 50°C for 1 minute, irradiated with 365 nm light using an aligner (Canon PLA-501) with varying exposure doses, then post-exposure baked (PEB), and developed with 1-propanol to form a photocured film. However, PEB requires a temperature of 100°C or higher, which exceeds the heat resistance of the polystyrene petri dish, and so deformation of the polystyrene petri dish was observed during PEB.
The sensitivity behavior on a polystyrene film is shown in FIG.
The sensitivity behavior on a silicon wafer is shown in FIG.

<e. Patterning test>
The polymer solution of Synthesis Example 1 was filtered using a polyethylene microfilter with a pore size of 1.0 μm to prepare a photocurable resin composition solution. The prepared solution was applied to the polystyrene film prepared in c by a spinner. The solution was baked on a hot plate at 50° C. for 1 minute to form a coating film with a thickness of 3.4 μm. The film was irradiated with 1000 mJ/cm2 of 254 nm light through a mask on which a dot pattern (dot/space=10 μm/15 μm) was drawn by an aligner. The film was then developed with 1-propanol for 3 minutes, spin-dried, and the pattern was observed with an electron microscope. An electron microscope photograph is shown in FIG. 3. As a result, good patterning performance was observed.

<f. Erosion test of polystyrene petri dish>
Comparative composition 2 was placed in a polystyrene petri dish (35 mm non-treated dish manufactured by IWAKI) and coating was attempted, but the petri dish dissolved. Compositions 1 and 2, in which propylene glycol monomethyl ether was replaced with 1-propanol, and Comparative composition example 1 did not dissolve the petri dish.

<g. Measurement of lower critical point temperature of reaction product>
The reaction products obtained in Synthesis Examples 1 and 2 were each dissolved in pure water at a concentration of 10% by weight. Under a nitrogen atmosphere, the temperature of the aqueous solution was raised at a rate of 1° C./min., and differential thermal measurement was performed using a differential scanning calorimeter (DSC) (SII Nano Technology Co., Ltd. "DSC7020"), and the peak top temperature of the obtained measurement curve was calculated as the lower critical point temperature (LCST) of the reaction product in pure water. The obtained measurement curves are shown in FIG. 4 and FIG. 5. The lower critical point temperatures (LCST) of the reaction products obtained in Synthesis Examples 1 and 2 in pure water were 23.8° C. and 28.9° C., respectively.
Moreover, measurements were performed in the same manner as above, except that pure water was replaced with phosphate buffered saline (PBS), and the lower critical point temperatures (LCSTs) of the reaction products obtained in Synthesis Examples 1 and 2 in phosphate buffered saline were calculated. The obtained measurement curves are shown in Figures 6 and 7. The lower critical point temperatures (LCSTs) of the reaction products obtained in Synthesis Examples 1 and 2 in phosphate buffered saline were 21.6°C and 26.6°C, respectively.

<h. Measurement of swelling degree of photocured film>
The photocurable resin composition solution prepared with composition 2 was applied to the polystyrene film prepared in c by a spinner. The film was baked on a hot plate at 50°C for 1 minute to form a coating film with a thickness of 11 μm. After irradiating 3000 mJ/cm2 of 254 nm light with an aligner, the film was developed with 1-propanol for 3 minutes, and then spin-dried. Next, the substrate was scratched and cleaved with a diamond pen, and the cross-section was set on the temperature-controlled stage of an inverted microscope (Olympus Corporation, IX71) so that the cross-section direction faces downward. Then, phosphate buffered saline (PBS) was dripped, and the substrate temperature was changed while the cross-section portion was immersed in phosphate buffered saline, and the change in film thickness was observed. The observation results are shown in FIG. 8. At 36°C, which is higher than the lower critical point temperature (LCST) of the reaction product obtained in Synthesis Example 2 in phosphate buffered saline of 26.6°C, the film thickness was 11 μm, whereas when the temperature was lowered to 18°C, which is lower than the lower critical point temperature (LCST), swelling occurred and the film thickness increased to 100 μm. The swelling degree (film thickness when swollen/film thickness when contracted) was 909%. When the temperature was then raised again to 36°C, which is higher than the lower critical point temperature (LCST), contraction occurred and the film thickness returned to 11 μm. This swelling and contraction could be repeated reversibly.
In addition, the photocurable resin composition solution prepared with composition 2 was replaced with the photocurable resin composition solution prepared with composition 1, and the swelling degree of the photocured film prepared using composition 1 was obtained by observing in the same manner as above. At 36°C, which is higher than 21.6°C, which is the lower critical point temperature (LCST) of the reaction product obtained in Synthesis Example 1 in phosphate buffered saline constituting the photocured film, the film thickness was 11 μm, whereas when the temperature was lowered to 18°C, which is lower than the lower critical point temperature (LCST), swelling occurred and the film thickness increased to 30 μm. The swelling degree (film thickness at swelling/film thickness at shrinkage) was 272%. Subsequently, when the temperature was raised again to 36°C, which is higher than the lower critical point temperature (LCST), shrinkage occurred and the film thickness returned to 11 μm. This swelling and shrinkage could be repeated reversibly.

<i. Cell detachment test on photocured film>
The photocurable resin composition solutions prepared in Compositions 3 and 4 were applied to a 35 mm polystyrene cell culture dish (Corning, 353001) using a spinner. The dish was baked on a hot plate at 50°C for 1 minute to form a coating film with a thickness of 5-10 nm or 11-22 nm. After irradiating the dish with 254 nm light at 1000 mJ/cm2 using an aligner, the dish was developed with 1-propanol for 1 minute, washed with pure water, and dried at 50°C. Mouse-derived fibroblast cells (KAC Co., Ltd., EC99072801-F0, 10T1/2 cells) were used. The medium used was Basal Medium Eagle (Thermo Fisher Scientific, 21010-046) supplemented with 10v/v% FETAL BOVINE SERUM (Nichirei Biosciences, 175012) and 1v/v% Penicillin-Streptomycin-Glutamine (Thermo Fisher Scientific, 10378-016). 10T1/2 cells were seeded at ^1x106 cells/35mm petri dish and cultured at 37°C and 5% CO2 for ₂₄ hours. After the culture, the 35 mm petri dish was placed on a table at 22°C, and the adhesion state of the cells after 0 to 10 minutes was confirmed by optical microscope and visual observation. [Figures 9a to 9d are photographs of the 5-10 nm thick film of composition 3 placed on a table at 22°C from 37°C 0-10 minutes after the film was placed on the table at 22°C. Figures 9a and 9b are optical microscope photographs of the upper left periphery of the petri dish, and Figures 9c and 9d are photographs of the entire petri dish. Figures 10a and 10b are optical microscope photographs (Figure 10a) and entire petri dish photographs (Figure 10b) of the 11-22 nm thick film of composition 3 left at 37°C.] As a result, as shown in Figure 9, in the case of a film thickness of 5-10 nm, 10T1/2 cells adhered to the 35 mm petri dish coated with composition 3 at 37°C, and by lowering the temperature to 22°C, the cells began to peel off from the edge of the petri dish (Figure 9b), and after 10 minutes, the cells were completely peeled off (Figure 9d). On the other hand, when the film thickness was 11-22 nm, no adhesion of 10T1/2 cells was observed even at 37° C. (FIG. 10b).

1. Phosphate-buffered saline (PBS)
2 Membrane 3 Substrate

Claims (10)

A film-attached plastic substrate having a film (C) made of a photocured product of a composition on a surface of the plastic substrate,
The composition contains a polymer (A) having a structural unit represented by the following formula (1):
The composition may comprise an optionally substituted aryl ketone (B),
When the aryl ketone (B) is not included in the composition, the polymer (A) has a residue of the aryl ketone (B);
When the aryl ketone (B) is contained in the composition, the polymer (A) may have a residue of the aryl ketone (B).

In formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms;
^R2 represents an optionally substituted alkyl group having 1 to 10 carbon atoms. The film-attached plastic substrate according to claim 1, wherein the aryl ketone (B) is an aryl ketone selected from the group consisting of acetophenone, benzophenone, anthraquinone, anthrone, a compound represented by the following formula (2), an anthrone analogue in which any carbon atom on the ring of the compound represented by formula (2) is replaced with a heteroatom, and derivatives of these compounds.

(In formula (2), R ³ to R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a hydroxy group, a sulfo group, a vinyl group, an acetoxy group, an aryl group having 6 to 14 carbon atoms which may be substituted with a hydroxy group, an amino group, or a mono- or di-alkylamino group having 1 to 4 carbon atoms;
X represents -O-, -S-, >CH ₂ , >C=O or >N-R, and R represents a hydrogen atom, a hydrocarbon group or an acyl group;
n1 represents 0 or 1, and n2 to n5 each independently represent 0, 1, 2, or 3, and n2 + n3 ≦ 3, n4 + n5 ≦ 4 are satisfied. The film-attached plastic substrate according to claim 1 , wherein the polymer (A) is a polymer having a structural unit represented by the following formula (3):

In formula (3), Ar represents a group represented by formula (4), formula (5), or formula (6),
R ¹ and R ⁷ each represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms;
^R2 represents an optionally substituted alkyl group having 1 to 10 carbon atoms;
L represents a divalent linking group;
x and y are arbitrary numbers satisfying x+y≦1, 0<x<1, and 0<y<1, respectively.
In formulas (4) to (6), * represents a bond to L.
^R3 to ^R6 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a hydroxy group, a sulfo group, a vinyl group, an acetoxy group, an aryl group having 6 to 14 carbon atoms which may be substituted with a hydroxy group, an amino group, or a mono- or di-alkylamino group having 1 to 4 carbon atoms;
X represents -O-, -S-, >CH ₂ , >C=O or >N-R, and R represents a hydrogen atom, a hydrocarbon group or an acyl group;
n1 represents 0 or 1, and n2 to n5 each independently represent 0, 1, 2, or 3, and n2 + n3 ≦ 3, n4 + n5 ≦ 4 are satisfied. The film-attached plastic substrate according to claim 3, wherein the formula (3) satisfies 0.01≦y/x≦0.2. The film-attached plastic substrate according to claim 1, wherein the optionally substituted aryl ketone (B) has a molecular weight of 500 or less. The film-attached plastic substrate according to claim 1, wherein the film (C) is a patterned film. The film-attached plastic substrate according to claim 1 or claim 6, wherein the plastic substrate has a glass transition temperature of 105°C or less. The method for producing a film-coated plastic substrate includes a step (1) of applying a solution containing the composition and an alcohol-based solvent to the surface of the plastic substrate to form a coating film, and a step (2) of irradiating the coating film with light. The method for producing a film-coated plastic substrate according to claim 8 further comprises a step (3) of developing the coating film after the light irradiation. The method for producing a film-coated plastic substrate according to claim 8 or 9, wherein the wavelength of the light in the step (2) is 150 nm or more and 600 nm or less.

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