JP2014114333A - Seal composition for porous low refractive index material, low refractive index member, and method for producing the same - Google Patents

Abstract

【Task】
Provided are a composition having excellent sealing properties with respect to a porous low-refractive index material, a low-refractive index member having a small refractive index variation using the composition, and a method for producing the same
A porous low-polymer containing a polymer having two or more cationic functional groups containing at least one of a tertiary nitrogen atom and a quaternary nitrogen atom and having a weight average molecular weight of 2,000 to 1,000,000 and a degree of branching of 48% or more. Seal composition for refractive index material.
[Selection figure] None

Description

  The present invention relates to a sealing composition for a porous low refractive index material, a low refractive index member, and a method for producing the same.

  When it is necessary to maximize the light transmittance, such as an optical device or a solar battery panel, an antireflection coating is generally applied to the outermost surface. When the optical material is in contact with air, the average refractive index of the antireflection coating material is set to an intermediate value between the refractive index of the coated optical material and air, as is generally known as the Fresnel formula. It is known that the reflectance is reduced.

  As an antireflection coating material for this purpose, a magnesium fluoride film having a refractive index of 1.38 and having a relatively simple film formation method is widely used. However, in order to further improve the characteristics of the antireflection film, a film material having a lower refractive index is desired. In addition, low refractive index materials are also required for cladding layers of optical waveguides and window materials for light emitting elements (Patent Documents 1 and 2, etc.).

  As a means for realizing a refractive index lower than that of a magnesium fluoride film, the use of a porous film in which pores are introduced into the film has been studied. In particular, a mesoporous silica film made of a mesoporous silica material having a pore diameter in the range of 2 to 50 nm is expected as a low refractive index layer of an antireflection film because of its excellent transparency in the visible light region. Non-Patent Document 1 describes a production method and a structure for various mesoporous materials. Patent Document 3 describes an antireflection film made of a mesoporous silica material.

  As a method for producing a mesoporous silica film, a sol-gel method is mainly used because it is a simple process and excellent in film quality. However, since the porous silica film produced by the sol-gel method generally has a large number of silanol groups remaining, there is a risk of refractive index fluctuations due to moisture absorption in the atmosphere and mesoporous structure collapse due to moisture absorption. As means for solving such a problem, Patent Document 4 discloses that the silanol groups remaining on the pore surfaces of the mesoporous silica material are chemically modified with an organic substance having hydrophobicity, thereby suppressing moisture absorption of the mesoporous silica material. A method is disclosed. Patent Document 5 discloses a method for suppressing fluctuations in the refractive index due to moisture absorption while suppressing an increase in the refractive index due to the introduction of fluorine by introducing fluorine into the vicinity of the surface layer of the porous material.

JP 2005-126497 A Japanese Patent Application Laid-Open No. 2004-2111 JP 2009-210739 A JP 2002-241124 A JP 2012-25650 A “Chem. Mater.”, Vol. 20, no. 3, p. 682, 2008

  The porous low refractive index material has a problem that the refractive index is likely to fluctuate due to moisture absorption or the like. For this reason, although the method of suppressing a hygroscopic property is disclosed by the said patent document 4, 5, the fluctuation | variation of the refractive index of porous low-refractive-index material was not fully suppressed.

  Accordingly, an object of the present invention is to provide a composition for a porous low-refractive index material that has excellent sealing properties with respect to a porous low-refractive index material, a low-refractive index member that uses the composition and has a small refractive index variation, and its manufacture Is to provide a method.

  As a result of intensive studies, the inventors have adjusted the degree of branching in a specific polymer so as to be a certain value or more, so that the sealing performance on the surface of the porous low refractive index material, particularly the sealing performance with respect to organic matter, is remarkably improved. As a result, the present invention has been completed.

That is, specific means for solving the above-described problems are as follows.
[1] A polymer having two or more cationic functional groups containing at least one of a tertiary nitrogen atom and a quaternary nitrogen atom and having a weight average molecular weight of 2,000 to 1,000,000 and a degree of branching of 48% or more. Seal composition for porous low refractive index material.
[2] The porous low refractive index according to [1], wherein the polymer has a structural unit derived from an alkyleneimine having 2 to 8 carbon atoms and containing a tertiary nitrogen atom as a cationic functional group. Sealing composition for the rate material.
[3] The porous material according to [2], wherein the polymer further includes a structural unit derived from an alkyleneimine having 2 to 8 carbon atoms and containing a secondary nitrogen atom as a cationic functional group. Seal composition for low refractive index material.
[4] Any one of [1] to [3], wherein the polymer contains a primary nitrogen atom, and a ratio of primary nitrogen atoms to all nitrogen atoms in the polymer is 33 mol% or more. The sealing composition for porous low-refractive-index materials as described in 2.
[5] The sealing composition for porous low refractive index materials according to any one of [1] to [4], wherein the degree of branching of the polymer is 55% or more.
[6] The sealing composition for a porous low refractive index material according to any one of [1] to [5], wherein the polymer is polyethyleneimine or a derivative of polyethyleneimine.
[7] The sealing composition for a porous low refractive index material according to any one of [1] to [6], wherein the polymer has a cationic functional group equivalent of 27 to 430.
[8] A sealing composition for a porous low refractive index material, wherein the low refractive index porous material has an average pore diameter of 4 nm or more.
[9] A low refractive index comprising a sealing composition application step of applying the seal composition according to any one of [1] to [8] to a porous low refractive index material having an average pore diameter of 4 nm or more. Manufacturing method of member.
[10] The method for producing a low refractive index member according to [9], wherein the porous material includes porous silica and has a silanol residue derived from the porous silica on a surface thereof.
[11] A porous low refractive index material; having two or more cationic functional groups containing at least one of a tertiary nitrogen atom and a quaternary nitrogen atom, having a weight average molecular weight of 2,000 to 1,000,000 and a degree of branching of 48% or more And a sealing layer having a thickness of 0.3 nm to 20 nm.
[12] An optical member having the low refractive index member according to [11].
[13] An optical waveguide having the low refractive index member according to [11].
[14] A window material for a light emitting device, comprising the low refractive index member according to [11].
[15] A lens having the low refractive index member according to [11].

<Seal composition for porous low refractive index material>
The seal composition of the present invention is used, for example, to form a polymer layer covering the pores of a porous low refractive index material, and includes two or more containing at least one of a tertiary nitrogen atom and a quaternary nitrogen atom. It contains a polymer having a cationic functional group and a weight average molecular weight of 2,000 to 1,000,000 and a degree of branching of 48% or more.

  When the sealing composition having such a structure is applied to a porous low refractive index material having a porous structure, for example, two or more cationic functional groups of the polymer are adsorbed on the porous low refractive index material. Then, pores (pores) present on the surface of the porous low refractive index material are covered with a polymer layer (hereinafter also referred to as a seal layer). Thereby, the penetration | invasion and the spreading | diffusion of the water | moisture content and organic substance to a porous low refractive index material can be suppressed (that is, the sealing performance outstanding with respect to the porous low refractive index material is expressed). Furthermore, since the polymer layer formed by the polymer is a thin layer (for example, 20 nm or less), it is possible to suppress a change in the refractive index without greatly increasing the refractive index of the porous low refractive index material. it can.

  In particular, in the sealing composition of the present invention, the two or more cationic functional groups contain at least one of a tertiary nitrogen atom and a quaternary nitrogen atom, and the degree of branching of the polymer is 48% or more. Excellent sealing properties can be obtained for low-refractive-index materials. That is, it is possible to remarkably suppress the entry and diffusion of moisture and organic substances into the porous low refractive index material. The reason for this is not clear, but it is estimated that if the degree of branching is high, the branched chains will be entangled and the gaps between the molecular chains will be reduced, effectively preventing moisture and organic matter from passing between the molecular chains. Is done.

[High molecular]
The seal composition of the present invention has two or more cationic functional groups containing at least one of a tertiary nitrogen atom and a quaternary nitrogen atom, has a weight average molecular weight of 2,000 to 1,000,000 and a degree of branching of 48% or more. It contains at least one molecule (hereinafter also referred to as “polymer of the present invention”). In the present invention, the “branch degree” refers to a value obtained by the following formula 1.
Degree of branching (%) = ((number of tertiary nitrogen atoms + number of quaternary nitrogen atoms) / (number of secondary nitrogen atoms + number of tertiary nitrogen atoms + number of quaternary nitrogen atoms)) × 100 Formula 1
Therefore, for example, when the polymer of the present invention is a polyalkyleneimine, the linear polyalkyleneimine has no tertiary nitrogen atom or quaternary nitrogen atom, and therefore has a branching degree of 0% and excludes the terminal. The polyalkyleneimine in which all the nitrogen atoms contained in the skeleton are tertiary nitrogen atoms (that is, branched to the maximum) has a degree of branching of 100%.

In the present invention, the “primary nitrogen atom” means a nitrogen atom bonded to only two hydrogen atoms and one atom other than a hydrogen atom (for example, nitrogen contained in a primary amino group (—NH ₂ group)). Atom) or a nitrogen atom (cation) bonded to only three hydrogen atoms and one atom other than hydrogen atoms.
The “secondary nitrogen atom” means a nitrogen atom bonded to only one hydrogen atom and two atoms other than hydrogen atoms (for example, a nitrogen atom contained in a functional group represented by the following formula (a)) Or a nitrogen atom (cation) bonded to only two hydrogen atoms and two atoms other than hydrogen atoms. The “tertiary nitrogen atom” is a nitrogen atom bonded to only three atoms other than a hydrogen atom (that is, a nitrogen atom which is a functional group represented by the following formula (b)) or a hydrogen atom It refers to a nitrogen atom (cation) bonded to only one atom and three atoms other than hydrogen atoms. Further, the “quaternary nitrogen atom” refers to a nitrogen atom (cation) bonded to only four atoms other than hydrogen atoms.
In the above, the “atom other than a hydrogen atom” is not particularly limited, and examples thereof include a carbon atom and a silicon atom, and a carbon atom is preferable.

In the formula (a) and the formula (b), * indicates a bonding position with an atom other than a hydrogen atom.
Here, the functional group represented by the formula (a) may be a functional group constituting a part of ^a secondary amino group (—NHR ^a group; where R ^a represents an alkyl group). Further, it may be a divalent linking group contained in the polymer skeleton. The functional group represented by the formula (b) (that is, tertiary nitrogen atom) is a tertiary amino group (—NR ^b R ^c group; where R ^b and R ^c are each independently alkyl May be a functional group constituting a part of the group, or a trivalent linking group contained in the polymer skeleton.

  The degree of branching of the polymer is required to be 48% or more, but from the viewpoint of further improving the sealing performance, the degree of branching is preferably 55% or more, more preferably 70% or more. Preferably, it is particularly preferably 75% or more. The upper limit of the degree of branching of the polymer is not particularly limited, but when the polymer contains a secondary nitrogen atom, the degree of branching is less than 100%. From the viewpoint of ease of synthesis, the degree of branching of the polymer is preferably 95% or less.

  The method for adjusting the degree of branching to 48% or more is not particularly limited, but for example, a method for adjusting the polymerization conditions of the monomer itself when synthesizing the polymer, a primary nitrogen atom contained in the polymer or 2 A method of increasing the degree of branching by generating a tertiary nitrogen atom or a quaternary nitrogen atom from a primary nitrogen atom or a secondary nitrogen atom by reacting the secondary nitrogen atom with another nitrogen-containing compound or an alkyl compound. Can be mentioned. A specific example of the latter method will be described later as a “polymer production method”.

  The polymer of the present invention preferably has a structural unit having a cationic functional group (a structural unit derived from a monomer having a cationic functional group). In this case, the structure of the polymer may be a structure formed by polymerizing a monomer having a cationic functional group in a chain form, or may be formed by polymerizing a monomer having a cationic functional group in a branched form. It may be a structured. The “cationic functional group” in the present invention is not particularly limited as long as it is a functional group capable of being positively charged. The cationic functional group is preferably a functional group containing a nitrogen atom (a primary nitrogen atom, a secondary nitrogen atom, a tertiary nitrogen atom, or a quaternary nitrogen atom). The “functional group containing a nitrogen atom” herein includes a functional group composed of only one nitrogen atom. The polymer of the present invention has two or more cationic functional groups containing at least one of a tertiary nitrogen atom and a quaternary nitrogen atom which are cationic functional groups. The polymer of the present invention may contain a primary nitrogen atom or a secondary nitrogen atom as a cationic functional group.

  When the polymer of the present invention contains a primary nitrogen atom, the proportion of primary nitrogen atoms in all the nitrogen atoms in the polymer is preferably 33 mol% or more. When the polymer of the present invention contains primary nitrogen atoms (particularly, the ratio of primary nitrogen atoms is 33 mol% or more), the wettability between the polymer and the interlayer insulating film is further improved, and the polymer layer Since the uniformity of the thickness is further improved, the sealing property can be further improved.

  Moreover, when the said polymer contains a primary nitrogen atom, it is preferable that nitrogen atoms other than primary, such as a secondary nitrogen atom, coexist besides a primary nitrogen atom. Thereby, it is easy to adjust the thickness of the polymer layer to an appropriate range, and the sealing property can be further improved.

Moreover, the polymer may further have an anionic functional group or a nonionic functional group as necessary.
The nonionic functional group may be a hydrogen bond accepting group or a hydrogen bond donating group. Examples of the nonionic functional group include a hydroxy group, a carbonyl group, and an ether group (—O—).
The anionic functional group is not particularly limited as long as it is a functional group that can be negatively charged. Examples of the anionic functional group include a carboxylic acid group, a sulfonic acid group, and a sulfuric acid group.

The polymer may be any polymer as long as it has two or more cationic functional groups containing at least one of a tertiary nitrogen atom and a quaternary nitrogen atom in one molecule. A polymer having a high density is preferred. Specifically, the cationic functional group equivalent is preferably 27 to 430, more preferably 43 to 200.
Further, when the surface of the porous low refractive index material is hydrophobized by a known method, for example, the method described in International Publication No. 04/026765, International Publication No. 06/025501, etc., the polarity of the surface It is also preferred that it is 43-200 since the density of the group is reduced.
Here, the cationic functional group equivalent means the weight average molecular weight per cationic functional group, and the number of cationic functional groups (n) contained in the polymer corresponding to one molecule is the weight average molecular weight (Mw) of the polymer. (Mw / n) obtained by dividing by. The larger the cationic functional group equivalent, the lower the density of the cationic functional group, while the smaller the cationic functional group equivalent, the higher the density of the cationic functional group.

  When the polymer of the present invention has a structural unit having a cationic functional group (hereinafter, also referred to as “specific structural unit”), the cationic functional group has a main chain in the specific structural unit. It may be included as at least a part, may be included as at least a part of the side chain, and may further be included as at least a part of the main chain and at least a part of the side chain. Furthermore, when the specific structural unit contains two or more cationic functional groups, the two or more cationic functional groups may be the same or different.

  The cationic functional group is a ratio of the main chain length of the specific structural unit to the average distance between the adsorption points (for example, silanol residues) of the cationic functional group present on the porous low refractive index material (hereinafter, "Sometimes referred to as" relative distance between cationic functional groups ") is preferably included so as to be 1.6 or less, and included so as to be 0.08 to 1.0. More preferred. With such an embodiment, the polymer can be more efficiently adsorbed on the porous low refractive index material more efficiently. The specific structural unit preferably has a molecular weight of 30 to 500, more preferably 40 to 200, from the viewpoint of adsorptivity to the porous low refractive index material. In addition, the molecular weight of a specific structural unit means the molecular weight of the monomer which comprises a specific structural unit.

  The specific structural unit in the present invention preferably has a relative distance between the cationic functional groups of 1.6 or less and a molecular weight of 30 to 500 from the viewpoint of adsorptivity to the porous low refractive index material. More preferably, the relative distance between the cationic functional groups is 0.08 to 1.0, and the molecular weight is 40 to 200.

Specific examples of the specific structural unit (structural unit having a cationic functional group) include unit structures derived from a cationic functional group-containing monomer exemplified below.
Specific examples of the cationic functional group-containing monomer include alkyleneimine, allylamine, diallyldimethylammonium salt, vinylpyridine, lysine, methylvinylpyridine, p-vinylpyridine and the like.
As said alkyleneimine, a C2-C12 alkyleneimine is preferable and a C2-C8 alkyleneimine is more preferable. Moreover, as said C2-C12 alkyleneimine, a C2-C8 substituted or unsubstituted cyclic amine is preferable.
Specific examples of the alkyleneimine having 2 to 12 carbon atoms include ethyleneimine (also known as aziridine), propyleneimine (also known as 2-methylaziridine), butyleneimine, pentyleneimine, hexyleneimine, heptyleneimine, octyleneimine, Examples include trimethyleneimine (also known as azetidine), tetramethyleneimine (also known as pyrrolidine), pentamethyleneimine (also known as piperidine), hexamethyleneimine, and octamethyleneimine. Among these, ethyleneimine is particularly preferable.
Among the above, the cationic functional group-containing monomer includes alkyleneimine (preferably alkyleneimine having 2 to 8 carbon atoms) and allylamine from the viewpoints of adsorptivity to porous low refractive index materials and sealing properties. And preferably an alkylene imine (preferably an alkylene imine having 2 to 4 carbon atoms, particularly preferably ethylene imine).

  In addition, the polymer of the present invention has 2 to 8 carbon atoms as the specific structural unit (structural unit having a cationic functional group) from the viewpoint of adsorptivity to a porous low refractive index material and sealing properties. More preferably, it is a structural unit derived from an alkyleneimine having 2 to 4 carbon atoms and containing a tertiary nitrogen atom.

  From the viewpoint of easiness of synthesis, the polymer of the present invention is a structural unit derived from an alkyleneimine having 2 to 8 carbon atoms (more preferably 2 to 4 carbon atoms) and containing a tertiary nitrogen atom. In addition to the “unit”, it is more preferable that the structural unit is derived from an alkyleneimine having 2 to 8 carbon atoms (more preferably 2 to 4 carbon atoms) and includes a secondary nitrogen atom.

  In addition, when a cationic functional group is introduced by reacting a nitrogen-containing compound with at least one of the primary nitrogen atom and the secondary nitrogen atom in the polymer in order to increase the degree of branching, the cationic property introduced into the polymer As the functional group, the following cationic functional group ("*" indicates the position of bonding with the nitrogen atom in the polymer skeleton), aminopropyl group, diaminopropyl group, aminobutyl group, diaminobutyl group, And a triaminobutyl group.

  Among the cationic functional groups introduced into the polymer, an aminoethyl group is preferred from the viewpoint of reducing the cationic functional group equivalent and increasing the cationic functional group density.

The polymer may further include at least one of a unit structure containing a nonionic functional group and a unit structure containing an anionic functional group.
Specific examples of the unit structure containing the nonionic functional group include a unit structure derived from vinyl alcohol, a unit structure derived from alkylene oxide, and a unit structure derived from vinyl pyrrolidone.

  Furthermore, as the unit structure containing an anionic functional group, specifically, a unit structure derived from styrene sulfonic acid, a unit structure derived from vinyl sulfate, a unit structure derived from acrylic acid, a unit structure derived from methacrylic acid, maleic Examples include a unit structure derived from an acid and a unit structure derived from fumaric acid.

  In the present invention, when the polymer contains two or more kinds of specific structural units, each specific structural unit may be different in any of the kinds or number of cationic functional groups contained, molecular weight, and the like. The two or more specific structural units may be included as a block copolymer or a random copolymer.

  The polymer may further include at least one kind of structural unit other than the specific structural unit (hereinafter sometimes referred to as “second structural unit”). When the polymer includes a second structural unit, the specific structural unit and the second structural unit may be included as a block copolymer or a random copolymer.

The second structural unit is not particularly limited as long as it is a structural unit derived from a monomer polymerizable with the monomer constituting the specific structural unit. Examples thereof include structural units derived from olefins.
When the polymer of the present invention does not have a specific structural unit and has a random structure formed by branching polymerization of monomers constituting the polymer, the cationic functional group contains It may be included as at least part of the chain, may be included as at least part of the side chain, and may be included as at least part of the main chain and at least part of the side chain.

  Specific examples of the polymer of the present invention include polyalkyleneimines (for example, polyethyleneimine (PEI)), polyallylamine (PAA), polydiallyldimethylammonium (PDDA), polyvinylpyridine (PVP), polylysine, polymethylpyridylvinyl ( PMPyV), protonated poly (p-pyridylvinylene) (R-PHPyV), and derivatives thereof. Among them, polyalkyleneimine (for example, polyethyleneimine (PEI)) or a derivative thereof, polyallylamine (PAA) or the like is preferable, and polyalkyleneimine (for example, polyethyleneimine (PEI)) or a derivative thereof is more preferable.

Polyethyleneimine (PEI) can be generally produced by polymerizing ethyleneimine by a commonly used method. A polymerization catalyst, polymerization conditions, and the like can also be appropriately selected from those generally used for polymerization of ethyleneimine. Specifically, for example, the reaction can be performed at 0 to 200 ° C. in the presence of an effective amount of an acid catalyst such as hydrochloric acid. Further, ethyleneimine may be addition-polymerized based on polyethyleneimine. The polyethyleneimine in the present invention may be a homopolymer of ethyleneimine or a compound copolymerizable with ethyleneimine, for example, a copolymer of amines and ethyleneimine. As for the method for producing such a polyethyleneimine, for example, JP-B 43-8828, JP-B 49-33120 and the like can be referred to.
The polyethyleneimine may be obtained using crude ethyleneimine obtained from monoethanolamine. Specifically, for example, Japanese Patent Application Laid-Open No. 2001-2213958 can be referred to.
Polyalkyleneimines other than polyethyleneimine can also be produced by the same method as polyethyleneimine.

Polyethyleneimine produced as described above has not only a partial structure in which ethyleneimine is opened and bonded in a straight chain, but also a branched partial structure and a linear partial structure are linked together. It has a complicated skeleton having a partial structure. Polyalkyleneimines other than polyethyleneimine also have the same structure as polyethyleneimine.
By using a polymer having a cationic functional group having such a structure, the polymer is more efficiently adsorbed at multiple points. Furthermore, the coating layer is more effectively formed by the interaction between the polymers.

  It is also preferred that the polymer of the present invention is a polyalkyleneimine derivative (preferably a polyethyleneimine derivative). The polyalkyleneimine derivative (preferably polyethyleneimine derivative) is not particularly limited as long as it is a compound that can be produced using the polyalkyleneimine (preferably polyethyleneimine). Specifically, a polyalkyleneimine derivative obtained by introducing an alkyl group (preferably having 1 to 10 carbon atoms) or an aryl group into polyalkyleneimine, or a polyalkyleneimine obtained by introducing a crosslinkable group such as a hydroxyl group into polyalkyleneimine. Derivatives and the like can be mentioned.

These polyalkyleneimine derivatives can be produced by a method usually performed using the above polyalkyleneimine. Specifically, for example, it can be produced according to the method described in JP-A-6-016809.
As the polyalkyleneimine derivative, a highly branched polyalkyleneimine obtained by improving the degree of branching of the polyalkyleneimine by reacting the polyalkyleneimine with a cationic functional group-containing monomer is also preferable.

  As a method of obtaining a highly branched polyalkyleneimine, for example, a polyalkyleneimine having a plurality of secondary nitrogen atoms in the skeleton is reacted with a cationic functional group-containing monomer, and the plurality of secondary nitrogen atoms A method of substituting at least a part of the monomer with a cationic functional group-containing monomer, or reacting a cationic functional group-containing monomer with a polyalkyleneimine having a plurality of primary nitrogen atoms at its ends, and the plurality of primary nitrogens. And a method of substituting at least one part of the atoms with a cationic functional group-containing monomer.

Examples of the cationic functional group introduced to improve the degree of branching include aminoethyl group, aminopropyl group, diaminopropyl group, aminobutyl group, diaminobutyl group, and triaminobutyl group. From the viewpoint of reducing the functional functional group equivalent and increasing the cationic functional group density, an aminoethyl group is preferred.
As a method for obtaining a highly branched polyalkyleneimine, for example, the method described in the “Method for producing polymer” described later can be used.
Furthermore, the polyethyleneimine and derivatives thereof may be commercially available. For example, it can be appropriately selected from polyethyleneimine and derivatives thereof commercially available from Nippon Shokubai Co., Ltd., BASF, etc.

The weight average molecular weight of the polymer in the present invention is 2,000 to 1,000,000, preferably 2,000 to 600,000, preferably 10,000 to 200,000, and more preferably 20,000 to 150,000.
When the weight average molecular weight of the polymer is larger than 1,000,000, when the porous low refractive index material is sealed using the sealing composition of the present invention, the sealing layer becomes difficult to be smooth. If the weight average molecular weight is less than 2,000, the polymer molecule size is smaller than the pore diameter of the porous low refractive index material, and the polymer molecule enters the pores of the porous low refractive index material and becomes porous. The refractive index of a low-refractive index material may increase. Also, there are cases where adsorption does not occur at multiple points. In addition, a weight average molecular weight is measured using the GPC apparatus normally used for the molecular weight measurement of a polymer | macromolecule.

  Further, the polymer is preferably a polymer having a critical micelle concentration in an aqueous solvent of 1% by weight or more or substantially not forming a micelle structure. Here, substantially not forming a micelle structure means that micelles are not formed under normal conditions such as in an aqueous solvent at room temperature, that is, the critical micelle concentration cannot be measured. By using such a polymer, it is easy to form a polymer layer (for example, 20 nm or less) having a thin molecular level, and an increase in the refractive index of the porous low refractive index material can be effectively suppressed. .

  Furthermore, the polymer of the present invention is preferably polyethyleneimine having a weight average molecular weight of 2000 to 1000000 and a cationic functional group equivalent of 27 to 430, and having a weight average molecular weight of 2000 to 600000, It is more preferable that the functional group equivalent is a polyethyleneimine having a functional group equivalent of 27 to 430, and a polyethyleneimine having a weight average molecular weight of 10,000 to 150,000 and a cationic functional group equivalent of 27 to 400 is particularly preferable. By being this aspect, the penetration | invasion and the spreading | diffusion of the water | moisture content and organic substance to a porous low refractive index material are suppressed more effectively.

  There is no restriction | limiting in particular in content of the said polymer in the sealing composition for porous low-refractive-index materials of this invention, For example, it can be 0.01-5.0 weight%, 0.02-0 .3% by weight is preferred. The content of the polymer in the composition can also be adjusted based on the area and pore density of the surface on which the polymer layer is formed using the seal composition of the present invention.

[Polymer production method]
As a method for producing the polymer of the present invention, for example, a production method having a step of reacting a monomer having a cationic functional group with a raw material polymer containing at least one of a primary nitrogen atom and a secondary nitrogen atom is suitable. It is. By the above reaction, at least one of a tertiary nitrogen atom and a quaternary nitrogen atom can be generated from at least one of a primary nitrogen atom and a secondary nitrogen atom contained in the raw material polymer. The polymer of the invention can be suitably obtained. The above reaction can be performed by combining a raw material polymer and a monomer having a cationic functional group in a solvent such as water or alcohol and heating to reflux. Although reaction time can be adjusted suitably, for example, 1 to 24 hours are preferable and 2 to 12 hours are more preferable. The raw material polymer in the above method is not particularly limited as long as it contains at least one of a primary nitrogen atom and a secondary nitrogen atom, but a raw material polymer containing a secondary nitrogen atom is preferable.

  Examples of the raw material polymer containing a secondary nitrogen atom include polyalkyleneimine, polyN-alkylamide, which is a polymer of alkyleneimine having 2 to 12 carbon atoms (preferably 2 to 8 carbon atoms), or derivatives thereof. Etc. Here, specific examples of the alkyleneimine having 2 to 12 carbon atoms are as described above. Moreover, as said derivative | guide_body, the polyalkylenimine etc. into which the anionic functional group was introduce | transduced are mentioned, for example.

  The weight average molecular weight of the raw material polymer is not particularly limited as long as it can produce the polymer of the present invention having a weight average molecular weight of 2,000 to 1,000,000 by reaction with a monomer having a cationic functional group. Absent. For example, the weight average molecular weight of the raw material polymer is preferably 1000 to 500000, more preferably 2000 to 200000, and particularly preferably 5000 to 150,000.

  The weight average molecular weight and molecular weight distribution referred to in the present invention are as follows: an aqueous solution having an acetic acid concentration of 0.5 mol / L and a sodium nitrate concentration of 0.1 mol / L is used as a developing solvent, and an analytical apparatus Shodex GPC-101, column Asahipak GF-7M HQ. Measured using a polyethylene glycol as a standard product. As is known from the Mark-Houwink-Sakurada equation, the GPC calibration curve changes as the degree of branching increases, so the weight average molecular weight and molecular weight distribution in Table 1 are numerical values in terms of polyethylene glycol.

  Moreover, as a monomer which has a cationic functional group used for said manufacturing method, a nitrogen containing compound is mentioned, for example.

Moreover, it is preferable that the cationic functional group in the monomer having a cationic functional group used in the above production method is bonded to a protective group that is stable under the reaction conditions. Thereby, since it can suppress that a cationic functional group monomer reacts, a polymer with a higher branching degree can be manufactured.
As the protecting group, a commonly used protecting group can be used. Examples of the protecting group include t-butoxycarbonyl group (Boc group), benzyloxycarbonyl group, methoxycarbonyl group, fluorenylcarbonyl group, formyl group, acetyl group, benzoyl group, phthaloyl group, allyl group, and benzyl group. Etc.
As the monomer having a cationic functional group bonded to a protective group, a nitrogen-containing compound having a nitrogen atom bonded to the protective group is more preferable.
Specific examples of the nitrogen-containing compound having a nitrogen atom bonded to a protecting group include compounds represented by any one of the following general formulas (m-1) to (m-3).

In said formula (m-1)-(m-3), R represents a protecting group and n represents the integer of 1-4.
The protecting group represented by R may be any functional group that is generally used as a protecting group for a nitrogen atom. For example, t-butoxycarbonyl group (Boc group), benzyloxycarbonyl group, methoxycarbonyl Group, fluorenylcarbonyl group, formyl group, acetyl group, benzoyl group, phthaloyl group, allyl group and benzyl group are preferred.
As the nitrogen-containing compound (monomer) having a nitrogen atom bonded to a protecting group, a compound represented by the above general formula (m-1) is particularly preferred, and a compound represented by the above general formula (m-1) And a compound in which n is 1 (protected aziridine) is particularly preferred.

  In addition, as a method for producing the polymer of the present invention, a raw material polymer containing a secondary nitrogen atom (for example, a polyalkyleneimine that is a polymer of an alkyleneimine having 2 to 12 carbon atoms) is added to the above general formula (m A production method having a step of reacting the compound represented by -1) is particularly preferred.

  Moreover, the manufacturing method of the said polymer | macromolecule may have other processes, such as the process of deprotecting the cationic functional group which has the protective group introduce | transduced into the polymer | macromolecule as needed.

  Further, the polymer of the present invention may further introduce a hydrophobic group such as an aromatic ring from the viewpoint of sealing properties against organic substances (from the viewpoint of improving hydrophobicity). Specifically, an aromatic ring may be introduced into the NH group using benzyl chloride.

[Other ingredients]
The sealing composition of the present invention can contain a solvent as required in addition to the polymer. The solvent in the present invention may be any solvent that can uniformly dissolve the polymer. For example, water (preferably ultrapure water), a water-soluble organic solvent (for example, alcohol etc.), etc. can be mentioned. In the present invention, from the viewpoint of micelle formation, it is preferable to use water or a mixture of water and a water-soluble organic solvent as a solvent.

  The boiling point of the solvent is not particularly limited, but is preferably 210 ° C. or lower, and more preferably 160 ° C. or lower. When the boiling point of the solvent is within the above range, for example, when a cleaning step or a drying step is provided after the step of bringing the sealing composition of the present invention described later into contact with the porous low refractive index material, the porous low refractive index is provided. The solvent can be removed without significantly impairing the refractive index of the material and at a low temperature that does not cause the sealing composition to peel from the porous low refractive index material.

  Furthermore, it is preferable that the sealing composition of the present invention does not contain a compound that corrodes or dissolves the porous low refractive index material. Specifically, for example, when the main material of the porous low refractive index material is an inorganic compound such as silica, when the fluorine compound or the like is included in the composition of the present invention, the porous low refractive index material is dissolved. As a result, the insulating property is impaired, and the refractive index may increase.

The seal composition of the present invention preferably contains only a compound having a boiling point of 210 ° C. or lower, preferably 160 ° C. or lower, or a compound that does not have decomposability even when heated to 250 ° C.
The “compound that is not decomposable even when heated to 250 ° C.” is a compound whose weight change after holding at 250 ° C. under nitrogen for 1 hour with respect to the weight measured at 25 ° C. is less than 50%. I mean.

  The seal composition of the present invention preferably has an average particle diameter measured by a dynamic light scattering method of 800 nm or less. When the average particle diameter is adjusted to 800 nm or less, light is not easily scattered on the surface of the seal layer, and it becomes easy to use as an optical material.

The pH of the sealing composition of the present invention is not particularly limited, but from the viewpoint of the adsorptivity of the polymer to the porous low-refractive index material, the pH may be higher than the isoelectric point of the porous low-refractive index material. preferable. The pH of the sealing composition of the present invention is preferably in the pH range where the cationic functional group is in a cation state. When the sealing composition has such a pH, the polymer is more efficiently adsorbed on the porous low-refractive index material due to electrostatic interaction between the porous low-refractive index material and the polymer.
The isoelectric point of the porous low refractive index material is the isoelectric point indicated by the compound constituting the porous low refractive index material.For example, when the compound constituting the porous low refractive index material is porous silica, The isoelectric point is around pH 2 (25 ° C.).
In addition, the pH range where the cationic functional group is in a cationic state means that the pH of the sealing composition is equal to or lower than the pK _{b of the} polymer containing the cationic functional group. For example, if a polymer containing cationic functional groups is polyallylamine, pK _b is 8-9, when polyethyleneimine, pK _b is 7-12.

  That is, the pH of the sealing composition in the present invention can be appropriately selected according to the type of compound constituting the porous low refractive index material and the type of polymer, and is preferably pH 2 to 12, for example. More preferably, the pH is 7-11. In addition, pH (25 degreeC) is measured using the pH measuring apparatus used normally.

<Seal reinforcement composition for porous low refractive index material>
After forming the seal layer using the seal composition of the present invention, a seal reinforcing composition may be added to the seal layer. By adding (applying) the seal reinforcing composition and adjusting the charge balance and pH of the seal layer, the seal layer can be improved in sealability by adjusting the thickness and density of the seal layer.

  The pH of the seal reinforcing composition can be appropriately adjusted and is not particularly limited, but is preferably 1 to 6, more preferably 2 to 5, and particularly preferably 2 to 4 from the viewpoint of improving the sealing property of the seal composition. Specific examples of the seal reinforcing composition include compounds containing an acid and those containing an acid containing an organic acid. More specifically, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, Dicarboxylic acids such as pimelic acid, maleic acid, fumaric acid, and phthalic acid, tricarboxylic acids such as trimellitic acid and tricarbarylic acid, tetracarboxylic acids such as pyromellitic acid and biphenyltetracarboxylic acid, hydroxybutyric acid, lactic acid, salicylic acid, etc. Oxymonocarboxylic acids such as malic acid and tartaric acid, oxytricarboxylic acids such as citric acid, aminocarboxylic acids such as aspartic acid and glutamic acid, and organic acids such as paratoluenesulfonic acid and methanesulfonic acid. it can.

<Method for producing low refractive index member>
The method for producing a low refractive index member of the present invention includes a sealing composition application step of applying the sealing composition of the present invention to a porous low refractive index material, and further includes other steps as necessary. Composed. The low refractive index member in the present invention means a member having at least a porous low refractive index material described later and the above-described polymer of the present invention.

  The porous low refractive index material in the present invention is not particularly limited as long as it is porous. The pore radius (pore radius) in the porous low-refractive index material is not particularly limited, but from the viewpoint of more effectively achieving the sealing effect in the present production method and from the viewpoint of lowering the refractive index, the pore radius. Is preferably 0.5 to 4.0 nm, and more preferably 1.0 to 3.0 nm.

  It is also a preferable aspect that the porous low refractive index material of the present invention has a functional group on the surface of which the polymer having the cationic functional group contained in the sealing composition is easily attached. Specifically, when the porous low refractive index material contains porous silica, it preferably has a silanol group (hereinafter also referred to as silanol residue). When the silanol residue interacts with a cationic functional group contained in the polymer, a thin layer made of the polymer is coated so that the polymer covers pores on the porous low refractive index material. It is formed.

As said porous silica, the porous silica normally used for a porous low-refractive-index material can be especially used without a restriction | limiting. For example, uniform mesopores utilizing the self-organization of an organic compound and an inorganic compound that are hydrothermally synthesized in a sealed heat-resistant container using silica gel and a surfactant described in the WO 91/11390 pamphlet. And oxides having the above-mentioned properties, and the condensates of alkoxysilanes and surfactants described in Nature, 1996, 379 (page 703) or Supramolecular Science, 1998, 5 (page 247). The porous silica etc. which are made can be mentioned.
Further, as the porous silica, porous silica described in International Publication No. 2009/123104 (paragraphs 0009 to 0187) and International Publication No. 2010/137711 (paragraphs 0043 to 0088) (for example, specific silica) It is also preferable to use porous silica formed using a composition containing a siloxane compound.

The manufacturing method of the low-refractive-index member of this invention includes the sealing composition provision process which provides the sealing composition of this invention to a porous low-refractive-index material.
There is no restriction | limiting in particular as a method to provide the sealing composition of this invention to the said porous low refractive index material, The method used normally can be used. For example, dipping (see, for example, US Pat. No. 5,208,111), spraying (eg, Schlenoff et al., Langmuir, 16 (26), 9968, 2000, Izquierdo et al., Langmuir, 21 (16), 7558, 2005). And a spin coating method (see, for example, Lee et al., Langmuir, 19 (18), 7592, 2003, J. Polymer Science, part B, polymer physics, 42, 3654, 2004) and the like. .

  The method for applying the seal composition by the spin coating method is not particularly limited. For example, the seal composition is formed on the porous low refractive index material while rotating the substrate on which the porous low refractive index material is formed with a spin coater. A method in which an object is dropped and then dried by increasing the number of rotations of the substrate can be used. Furthermore, after repeating the dripping of the sealing composition and the dripping of water a plurality of times, the sealing composition may be dried. Also, after dripping the sealing composition, dry it by increasing the number of rotations, and after drying, transfer it to a heat treatment device such as a hot plate and perform heat treatment again. After the heat treatment, return to the spin coater again to perform rinsing treatment and drying. (The above operation may be repeated a plurality of times).

  In the application method of the sealing composition by the spin coating method, various conditions such as the rotation speed of the substrate, the dropping amount and dropping time of the sealing composition, the rotating speed of the substrate during drying, the dropping amount and dropping time of the rinse liquid, etc. Is not particularly limited, and can be appropriately adjusted in consideration of the thickness of the polymer layer (seal layer) to be formed.

  In the method for producing a low refractive index member of the present invention, the polymer layer containing the polymer can be formed into a thin layer on the porous low refractive index material by using the sealing composition containing the polymer. it can. Although there is no restriction | limiting in particular in the thickness of the said polymer layer, For example, it is 0.3 nm-30 nm, Preferably it is 0.3 nm-20 nm, More preferably, it is 0.3 nm-5 nm, Most preferably, it is 0. .5 nm to 3 nm.

  The polymer layer referred to here is not only in the form of a layer composed of only a polymer, but also in the form of a layer in which the polymer is soaked into the pores of the porous low refractive index material (so-called soaking layer). Including.

  In the method for producing a low refractive index member of the present invention, the seal composition contains a polymer having a cationic functional group equivalent of 27 to 430, and the pH of the seal composition is the porous low refractive index material. It is preferable that it is in the pH range where the cationic functional group is in a cationic state, more preferably 2 to 12, and more preferably 7 to 11. Further preferred. By bringing the sealing composition into contact with the porous low refractive index material, the polymer is more efficiently adsorbed on the porous low refractive index material.

  The isoelectric point of the porous low refractive index material and the pH range in which the cationic functional group is in a cation state are as described above.

  In the present invention, after the sealing composition is brought into contact with the porous low refractive index material, a cleaning step, a drying step, irradiation with an electron beam, ultraviolet rays, plasma treatment, or the like may be further provided as necessary. . Moreover, you may add the process of apply | coating the above-mentioned seal reinforcement composition on a seal layer. The method for applying the seal reinforcing composition is not particularly limited, and a method similar to the method for forming the seal layer described above can be used.

<Optical member>
The optical member of the present invention includes a porous low refractive index material and a polymer having a weight average molecular weight of 2,000 to 1,000,000 having two or more cationic functional groups containing at least one of a tertiary nitrogen atom and a quaternary nitrogen atom. An optical member having at least a part of the low refractive index member having a polymer layer having a thickness of 0.3 nm to 20 nm. In addition, the optical member of this invention can be manufactured with the manufacturing method of the said low refractive index member.

The optical member used in the present invention is not particularly limited as long as it can be used for optics, and specific examples include an optical waveguide, a window material for a light emitting element, and a lens.
The low refractive index member of the present invention has a low refractive index, and due to the sealing composition of the present invention, there is little fluctuation in the refractive index due to diffusion or penetration of moisture and organic matter, particularly organic matter contained in the atmosphere, into the porous material. . For this reason, window materials and lenses for light emitting elements used in liquid crystal displays, LDE displays, and the like can be suitably used as antireflection films in order to reduce reflection of external light on the surface. Further, the low refractive index member of the present invention can be suitably used as a cladding layer of an optical waveguide because of its low refractive index and small refractive index variation. Further, since the seal layer formed by the seal composition of the present invention is thin as described above, the adhesion between the core layer and the clad layer of the optical waveguide is not significantly reduced.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. For example, the porous low refractive index material is not limited to porous low silica.

[Synthesis Example 1]
Synthesis of highly branched polyethyleneimine 1) <Synthesis of branched polyethyleneimine 1>
(Synthesis of modified polyethyleneimine 1)
According to the following reaction scheme 1, modified polyethyleneimine 1 was synthesized using polyethyleneimine as a starting material. In addition, the polymer structure in the following reaction scheme 1 and reaction scheme 2 is a structure schematically represented, and the arrangement of a tertiary nitrogen atom and a secondary nitrogen atom, or secondary nitrogen substituted by a Boc aminoethyl group described later The ratio of atoms varies depending on the synthesis conditions.

In the above reaction scheme 1, * represents a bonding position.

In this synthesis example 1, the detailed operation of the above reaction scheme 1 was as follows.
8.0 g of polyethyleneimine (50% aqueous solution) manufactured by MP-Biomedicals was dissolved in 53 mL of isopropanol, and 13.3 g (93 mmol) of N-t-butoxycarbonyl (also referred to as “Boc” in this example) was added. The mixture was heated under reflux for 8 hours to obtain a modified polyethyleneimine 1 having a structure in which a Boc-aminoethyl group was introduced into polyethyleneimine. It was confirmed by thin layer chromatography (TLC) that the starting aziridine derivative disappeared, a small amount was sampled, and the structure was confirmed by ¹ H-NMR. ^{From 1} H-NMR, it was calculated that the introduction ratio of the Boc aminoethyl group to the polyethyleneimine was 95%. ¹ H-NMR (CD ₃ OD); δ 3.3-3.0 (br.s, 2), 2.8-2.5 (Br. S, 6.2), 1.45 (s, 9)

(Synthesis of branched polyethyleneimine 1)
Using the modified polyethyleneimine 1 as a starting material, a branched polyethyleneimine 1 was synthesized according to the following reaction scheme 2.

In this synthesis example 1, the detailed operation of the above reaction scheme 2 was as follows.
18 mL of 12N hydrochloric acid was slowly added to the isopropanol solution of the modified polyethyleneimine 1 described above. The resulting solution was heated and stirred at 50 ° C. for 3 hours while paying attention to gas generation. With the generation of gas, a gum-like reaction product was generated in the reaction system. When the generation of gas was completed, after cooling, the solvent separated from the gum-like reactant was removed, and the mixture was washed 4 times with 15 mL of methanol. The remaining reaction product was dissolved in water, and chloride ions were removed with an anion exchange polymer to obtain 26 g (purity: about 30%) of branched polyethyleneimine 1. ¹ H-NMR (D ₂ O); δ 2.8-2.4 (br.m)

2) <Synthesis of branched polyethyleneimine 2>
(Synthesis of modified polyethyleneimine 2)
The above branched polyethyleneimine 1, 9.1 g (purity about 30%) was dissolved in 31 mL of isopropanol, and Nt-butoxycarbonyl (also referred to as “Boc” in this example) aziridin 7.8 g (54.4 mmol) And heated under reflux for 8 hours to obtain a modified polyethyleneimine 2 having a structure in which a Bocated aminoethyl group was introduced into polyethyleneimine. It was confirmed by thin layer chromatography (TLC) that the starting aziridine derivative disappeared, a small amount was sampled, and the structure was confirmed by ¹ H-NMR. ^{From 1} H-NMR, it was calculated that the introduction ratio of the Boc aminoethyl group with respect to polyethyleneimine was 90%. ¹ H-NMR (CD ₃ OD); δ 3.3-3.0 (br.s, 2), 2.8-2.5 (Br. S, 6.2), 1.45 (s, 9)

(Synthesis of branched polyethyleneimine 2)
Using the modified polyethyleneimine 2 as a starting material, a branched polyethyleneimine 2 was synthesized according to the above reaction scheme 2.

In this synthesis example 1, the detailed operation of the above reaction scheme 2 was as follows.
To the isopropanol solution of the modified polyethyleneimine 2 was slowly added 13 mL of 12N hydrochloric acid. The resulting solution was heated and stirred at 50 ° C. for 4 hours while paying attention to gas generation. With the generation of gas, a gum-like reaction product was generated in the reaction system. When the generation of gas was completed, after cooling, the solvent separated from the gum-like reaction product was removed, and the mixture was washed 3 times with 10 mL of methanol. The remaining reaction product was dissolved in water, chlorine ions were removed with an anion exchange polymer, and 11.29 g (purity: about 40%) of branched polyethyleneimine 2 was obtained. ¹ H-NMR (D ₂ O); δ 2.8-2.4 (br.m)

3) <Synthesis of hyperbranched polyethyleneimine>
(Synthesis of modified polyethyleneimine 3)
The above branched polyethyleneimine 2, 4.7 g (purity of about 40%) was dissolved in 22.5 mL of isopropanol, and Nt-butoxycarbonyl (also referred to as “Boc” in the present example) 5.6 g (39. 4 mmol) was added and heated under reflux for 8 hours to obtain a modified polyethyleneimine 3 having a structure in which a Bocated aminoethyl group was introduced into polyethyleneimine. It was confirmed by thin layer chromatography (TLC) that the starting aziridine derivative disappeared, a small amount was sampled, and the structure was confirmed by ¹ H-NMR. ^{From 1} H-NMR, it was calculated that the introduction ratio of the Boc aminoethyl group with respect to polyethyleneimine was 90%. ¹ H-NMR (CD ₃ OD); δ 3.3-3.0 (br.s, 2), 2.8-2.5 (Br. S, 6.2), 1.45 (s, 9)

(Synthesis of hyperbranched polyethyleneimine)
Using the modified polyethyleneimine 3 as a starting material, hyperbranched polyethyleneimine 1 was synthesized according to the above reaction scheme 2.

In this synthesis example 1, the detailed operation of the above reaction scheme 2 was as follows.
9N of 12N hydrochloric acid was slowly added to the isopropanol solution of the modified polyethyleneimine 3 described above. The resulting solution was heated and stirred at 50 ° C. for 4 hours while paying attention to gas generation. With the generation of gas, a gum-like reaction product was generated in the reaction system. When the generation of gas was completed, after cooling, the solvent separated from the gum-like reaction product was removed, and the mixture was washed 3 times with 10 mL of methanol. The remaining reaction product was dissolved in water, and chlorine ions were removed with an anion exchange polymer to obtain 8.4 g of ultra-highly branched polyethyleneimine (purity of about 40%). ¹ H-NMR (D ₂ O); δ 2.8-2.4 (br.m)

About the highly branched polyethyleneimine 1, the weight average molecular weight, molecular weight distribution, cationic functional group (primary nitrogen atom, secondary nitrogen atom, tertiary nitrogen atom, and quaternary nitrogen atom) equivalent, the amount of primary nitrogen atom ( mol%), the amount of secondary nitrogen atoms (mol%), the amount of tertiary nitrogen atoms (mol%), the amount of quaternary nitrogen atoms (mol%), and the degree of branching (%) were measured. The measurement results are shown in Table 1 described later.
Here, the cationic functional group equivalent is a molecular weight value for one cationic functional group, and can be calculated from the polymer structure.
The amount of primary nitrogen atoms (mol%), the amount of secondary nitrogen atoms (mol%), the amount of tertiary nitrogen atoms (mol%), the amount of quaternary nitrogen atoms (mol%), and the degree of branching ( %) Was obtained by dissolving a polymer sample in heavy water and measuring ¹³ C-NMR at 80 ° C. by a decoupling method with a single pulse reverse gate using a Bruker AVANCE 500 nuclear magnetic resonance apparatus. It was analyzed whether it was bonded to a secondary amine (nitrogen atom) and calculated based on the integral value. The attribution is described in European Polymer Journal, 1973, Vol. 9, pp. 559.

  The weight average molecular weight and molecular weight distribution were measured using a column Asahipak GF-7M HQ using an analyzer Shodex GPC-101, and were calculated using polyethylene glycol as a standard product. The developing solvent was an aqueous solution having an acetic acid concentration of 0.5 mol / L and a sodium nitrate concentration of 0.1 mol / L. However, as known from the Mark-Houwink-Sakurada equation, the GPC calibration curve changes as the degree of branching increases, so the weight average molecular weight and molecular weight distribution in Table 1 are numerical values in terms of polyethylene glycol.

Here, the amount of primary nitrogen atoms (mol%), the amount of secondary nitrogen atoms (mol%), the amount of tertiary nitrogen atoms (mol%), and the amount of quaternary nitrogen atoms (mol%) are respectively The amount is represented by the following formulas A to D.
Amount of primary nitrogen atom (mol%) = (mol number of primary nitrogen atom / (mol number of primary nitrogen atom + mol number of secondary nitrogen atom + mol number of tertiary nitrogen atom + mol number of quaternary nitrogen atom)) ) × 100 Formula A
Amount of secondary nitrogen atom (mol%) = (mol number of secondary nitrogen atom / (mol number of primary nitrogen atom + mol number of secondary nitrogen atom + mol number of tertiary nitrogen atom + mol number of quaternary nitrogen atom)) ) × 100 Formula B
Amount of tertiary nitrogen atom (mol%) = (number of moles of tertiary nitrogen atom / (number of moles of primary nitrogen atom + number of moles of secondary nitrogen atom + number of moles of tertiary nitrogen atom + number of moles of quaternary nitrogen atom)) ) × 100 ・ ・ ・ Formula C
Amount of quaternary nitrogen atom (mol%) = (mol number of quaternary nitrogen atom / (mol number of primary nitrogen atom + mol number of secondary nitrogen atom + mol number of tertiary nitrogen atom + mol number of quaternary nitrogen atom)) ) × 100 Formula D
The degree of branching was determined by the following formula E.
Branch degree (%) = ((Amount of tertiary nitrogen atom (mol%) + Amount of quaternary nitrogen atom (mol%)) / (Amount of secondary nitrogen atom (mol%) + Amount of tertiary nitrogen atom (mol%) ) + Amount of quaternary nitrogen atom (mol%)) × 100 Formula E

[Synthesis Example 2]
<Synthesis of hyperbranched polyethyleneimine 2>
(Synthesis of modified polyethyleneimine 4)
According to the above reaction scheme 1, modified polyethyleneimine 4 was synthesized using polyethyleneimine as a starting material. In this synthesis example 2, the detailed operation of the above reaction scheme 1 was as follows.

61.06 g of polyethyleneimine (50% aqueous solution) manufactured by MP-Biomedicals was dissolved in 319 mL of isopropanol, and 102 g (710 mmol) of Nt-butoxycarbonyl (also referred to as “Boc” in the present example) aziridine was added. The mixture was heated under reflux for a period of time to obtain a modified polyethyleneimine 2 having a structure in which a Bocated aminoethyl group was introduced into polyethyleneimine. It was confirmed by thin layer chromatography (TLC) that the starting aziridine derivative disappeared, a small amount was sampled, and the structure was confirmed by ¹ H-NMR. ^{From 1} H-NMR, it was calculated that the introduction ratio of the Boc aminoethyl group to the polyethyleneimine was 95%.

¹ H-NMR (CD ₃ OD); δ 3.3-3.0 (br.s, 2), 2.8-2.5 (Br. S, 6.2), 1.45 (s, 9)
(Synthesis of hyperbranched polyethyleneimine 2)
Using the modified polyethyleneimine 4 as a starting material, hyperbranched polyethyleneimine 2 was synthesized according to the above reaction scheme 2.

In this synthesis example 2, the detailed operation of the above reaction scheme 2 was as follows.
124N of 12N hydrochloric acid was slowly added to the isopropanol solution of the modified polyethyleneimine 4 described above. The resulting solution was heated and stirred at 50 ° C. for 4 hours while paying attention to gas generation. With the generation of gas, a gum-like reaction product was generated in the reaction system. When the generation of gas was completed, after cooling, the solvent separated from the gum-like reactant was removed, and the mixture was washed with 184 mL of methanol three times. The remaining reactant was dissolved in water, chlorine ions were removed with an anion exchange polymer, and an aqueous solution containing 58 g of hyperbranched polyethyleneimine 2 was obtained.
¹ H-NMR (D ₂ O); δ 2.8-2.4 (br.m)
¹³ C-NMR (D ₂ O); δ (integral ratio) 57.2 (1.0), 54.1 (0.38), 52.2 (2.26), 51.6 (0.27) , 48.5 (0.07), 46.7 (0.37), 40.8 (0.19), 38.8 (1.06)

  About the highly branched polyethyleneimine 2, the weight average molecular weight, molecular weight distribution, cationic functional group (primary nitrogen atom, secondary nitrogen atom, tertiary nitrogen atom, and quaternary nitrogen atom) equivalent, the amount of primary nitrogen atom ( mol%), the amount of secondary nitrogen atoms (mol%), the amount of tertiary nitrogen atoms (mol%), the amount of quaternary nitrogen atoms (mol%), and the degree of branching (%) were measured. The measurement results are shown in Table 1 described later.

<Formation of porous low refractive index material>
[Synthesis Example 1]
A porous silica forming composition was prepared using the following components, and a porous low refractive index material Low-n1 was formed using the obtained porous silica forming composition.

(Components of porous silica forming composition)
-Alkoxysilane compounds-
Bistriethoxysilylethane (manufactured by Gelest, (C2H5O) 3SiCH2CH2Si (OC2H5) 3) is purified by distillation.

Dimethyldiethoxysilane (manufactured by Yamanaka Semiconductor, electronic industry grade, ((CH3) 2Si (OC2H5) 2)).
-Surfactant-
Polyoxyethylene (20) stearyl ether (manufactured by Sigma Chemical Co., Ltd., trade name: Brij78, C18H37 (CH2CH2O) 2OH) is dissolved in ethanol for electronics industry.
-Disilyl compound-
Hexamethyldisiloxane (manufactured by Aldrich, ((CH3) 3Si) 2O) is purified by distillation.
-Water-
Pure water with a resistance value of 18 MΩ or more that has been demetalized.
-Organic solvent-
Ethanol (Wako Pure Chemical Industries, Electronics Industrial Grade, C2H5OH)
1-propyl alcohol (manufactured by Kanto Chemical, electronics industry grade, CH3CH2CH2OH)
2-butyl alcohol (manufactured by Kanto Chemical Co., Ltd., electronics grade, CH3 (C2H5) CHOH).

(Preparation of precursor solution)
After 77.4 g of bistriethoxysilylethane and 70.9 g of ethanol were mixed and stirred at room temperature, 80 mL of a 0.1 mol / L nitric acid aqueous solution was added and stirred at 50 ° C. for 1.5 hours. Next, the reaction temperature was lowered to 30 ° C., and a solution in which 31.3 g of polyoxyethylene (20) stearyl ether was dissolved in 280 g of ethanol was added dropwise. After mixing, the mixture was stirred for 3 hours. Further, a solution in which 0.5 g of cetyltrimethylammonium chloride (CTAC) was dissolved in 72 g of 2-butyl alcohol was added dropwise and stirred for 1 hour. The resulting solution was concentrated to 123 g under reduced pressure at 25 ° C. and 30 hPa. After concentration, a solvent in which 5% by volume of propylene glycol monomethyl ether acetate (PGMEA) was added to a solution in which 1-propyl alcohol and 2-butyl alcohol were mixed at a volume ratio of 2: 1 was added, and 1810 g of a precursor solution was added. Obtained.

(Preparation of composition for forming porous silica)
1.6 g of dimethyldiethoxysilane and 0.9 g of hexamethyldisiloxane were added to 218 g of the precursor solution and stirred at 25 ° C. for 30 minutes to obtain a composition for forming porous silica. At this time, the addition amounts of dimethyldiethoxysilane and hexamethyldisiloxane were 40 mol% and 20 mol%, respectively, with respect to bistriethoxysilylethane.

(Formation of porous low refractive index material)
A porous silica-forming composition (2.5 mL) was dropped on the surface of a φ300 mm silicon wafer, rotated at 1750 rpm for 1 second, further rotated at 600 rpm for 60 seconds, dried, then at 150 ° C. for 1 minute in a nitrogen atmosphere, and then And heat treatment at 350 ° C. for 2 minutes. Then, the low-n material 1 (porous silica film) was obtained by heating to 350 ° C. in a chamber equipped with a 172 nm excimer lamp, and irradiating with ultraviolet rays at a pressure of 1 Pa and an output of 14 mW / cm 2 for 10 minutes. The pore radius of the obtained porous material was 2.6 nm.

(Evaluation of porous low refractive index materials)
The refractive index and pore radius of the porous low-refractive index material were obtained by calculation from the desorption isotherm of toluene. Here, the toluene desorption isotherm measurement was performed using an optical porosimeter (PS-1200) manufactured by SEMILAB by the same method as the above-described method and sealability evaluation described later. The calculation of the pore radius is M. The density is 0 to 1.5 ° under the conditions of X-ray power supply 50 kV, 300 mA, wavelength 1.5418 mm using an XRD apparatus (Rigaku Corporation, TPR-In-Plane). Measurement was carried out in the usual manner within the scanning range.

The pore radius of the porous low refractive index material was calculated from the desorption isotherm of toluene.
Here, the toluene desorption isotherm was measured using the method described above and an optical porosimeter (PS-1200) manufactured by SEMILAB. The calculation method of the pore radius is
In accordance with the method described in MR Baklanov, KP Mogilnikov, VG Polovinkin, and FN Dultsey, Journal of Vacuum Science and Technology B (2000) 18, 1385-1391, the Kelvin equation was used. I went. It was measured by.

[Synthesis Example 2]
Porous low refractive index material Low-n2 was formed in the same manner as in Synthesis Example 1 of porous low refractive index material except that 20.9 g of polyoxyethylene (20) stearyl ether was used.

[Example 1]
<Preparation of sealing composition>
The highly branched polyethyleneimine 1 (250 mg) was dissolved in 100 mL of water to obtain a sealing composition for a porous low refractive index material (hereinafter also referred to as “sealing composition 1”). Next, 4 mg of PMDA (pyromellitic anhydride, manufactured by Mitsubishi Chemical Corporation) was dissolved in 100 mL of water to obtain a seal reinforcing composition 1.

<Applying seal composition>
1 mL of the sealing composition 1 was dropped on the low-n material 1 and held for 23 seconds. Then, the silicon wafer with the low-n material 1 was rotated at 4000 rpm for 1 second by a spin coater, and further rotated at 600 rpm for 30 seconds. After that, it was further dried by rotating at 2000 rpm for 10 seconds.
Further, it was transferred onto a hot plate and in the atmosphere at 125 ° C. for 1 min. Heat-treated. Next, the silicon wafer is returned to the spin coater, and the substrate on which the seal layer is formed on the surface of the silicon wafer on which the sealing composition 1 is dropped is rotated at 600 rpm with the spin coater while the seal layer is rotated. The seal reinforcing composition 1 was dropped on the top at a dropping rate of 0.1 mL / second for 30 seconds to reinforce the sealing layer, and then rotated and dried at 2000 rpm for 60 seconds. Further, while rotating at 600 rpm, 3.0 mL of ultrapure water was dropped at a constant speed for 30 seconds, and then rotated and dried at 2000 rpm for 60 seconds.

As described above, the resin layer (seal layer) included in the seal composition 1 is formed on the material, and the silicon wafer, the material, and the seal layer (hereinafter also referred to as PS or PS layer) are sequentially laminated. (Hereinafter also referred to as “sample (Si / porous material / PS)”).
As the “water”, ultrapure water (Milli-Q water manufactured by Millipore, resistance of 18 MΩ · cm (25 ° C.) or less) was used.

  The thickness of the sealing layer after applying the sealing composition 1 directly to the silicon wafer and drying as described above was measured by an ellipso method to be 4.5 nm (hereinafter, measured by the same method) The thickness of the sealing layer is also referred to as “the thickness of the sealing layer on the Si substrate”).

<Refractive index evaluation>
Refractive index measurement was performed using a sample (Si / porous material / PS).
The measurement was carried out after cutting into 2 cm squares and setting in a sample chamber of an optical porosimeter (PS-1200) manufactured by SEMILAB. As an analytical model, a porous material / PS laminate was taken as one layer, and a refractive index was obtained using a Cauchy model assuming no absorption. Further, when estimating the thickness of the PS layer alone, the thickness was determined by two-layer analysis with the surface seal layer (PS) and the low refractive index layer (LK) as separate layers. At this time, in order to improve the fitting accuracy of PS, the PS layer was analyzed by adding a + Lorentz term to the Cauchy equation. Next, in order to evaluate the sealing property, the sample is left in the atmosphere of 23 ° C. and humidity of 40 to 60%, left to stand for 1 to 34 days, and then the refractive index is measured by the method as described above. Evaluation was performed based on the rate of change from the refractive index. Specifically, the refractive index of the porous material / PS after being left for a predetermined number of days is subtracted from 1 and the refractive index of the porous material / PS after being left for a predetermined number of days is subtracted and the result obtained by multiplying by 100 is the change in refractive index. Rate. The smaller the rate of change, the higher the sealing performance.

[Example 2]
Example 1 except that the hyperbranched polyethyleneimine 1 was changed to a hyperbranched polyethyleneimine 2 of the same mass, the porous low refractive index material was Low-n2, and the seal layer was not reinforced using the seal reinforcing composition In the same manner as above, a seal composition was prepared (hereinafter referred to as “seal composition 2”), a seal layer was formed, and measurement and evaluation were performed. Note that the thickness of the seal layer on the Si substrate was 4.4 nm.

Example 3
A seal layer was formed in the same manner as in Example 2 except that the seal layer was reinforced in the same manner as in Example 1 using the seal reinforcing composition 1, and measurement and evaluation were performed. The thickness of the seal layer on the Si substrate was 2.8 nm.

Example 4
4 mg of BPDA (3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, manufactured by Mitsubishi Chemical Corporation) was dissolved in 100 mL of water to obtain a seal reinforcing composition 2. Measurement and evaluation were performed in the same manner as in Example 2 except that the seal reinforcing composition 2 was used to reinforce the seal layer in the same manner as in Example 1. The thickness of the seal layer on the Si substrate was 5.4 nm.

[Comparative Example 1]
Measurement and evaluation were performed in the same manner as in Example 1 except that the seal composition was not used.
[Comparative Example 2]
Measurement and evaluation were performed in the same manner as in Example 2 except that the seal composition was not used.

 From Comparative Examples 1 and 2, the low-refractive-index materials Low-n materials 1 and 2 have a refractive index of 1 even though hexamethyldisiloxane as a hydrophobizing agent is sufficiently added to the precursor. It can be seen that the rate of change fluctuates up to about 5%.

  On the other hand, when Examples 1-4 and Comparative Examples 1 and 2 are compared, the refractive index change rate can be suppressed to 0.6% or less by forming the seal layer using the seal composition of the present invention. I understand that. Moreover, the refractive index after sealing of Examples 1-4 is 1.35 or less, and it can be seen that a low refractive index can be maintained even when a sealing layer is provided.

Claims (15)

  A porous low-polymer containing a polymer having two or more cationic functional groups containing at least one of a tertiary nitrogen atom and a quaternary nitrogen atom and having a weight average molecular weight of 2,000 to 1,000,000 and a degree of branching of 48% or more. Seal composition for refractive index material.   2. The porous low-refractive-index material according to claim 1, wherein the polymer has a structural unit derived from an alkyleneimine having 2 to 8 carbon atoms and containing a tertiary nitrogen atom as a cationic functional group. Sealing composition.   The porous low refractive index according to claim 2, wherein the polymer further has a structural unit derived from an alkyleneimine having 2 to 8 carbon atoms and containing a secondary nitrogen atom as a cationic functional group. Seal composition for material.   The said polymer | macromolecule contains a primary nitrogen atom, The ratio of the primary nitrogen atom which occupies for all the nitrogen atoms in the said polymer | macromolecule is 33 mol% or more, The any one of Claims 1-3. Seal composition for porous low refractive index material.   The sealing composition for porous low refractive index materials according to any one of claims 1 to 4, wherein the degree of branching of the polymer is 55% or more.   The sealing composition for a porous low refractive index material according to any one of claims 1 to 5, wherein the polymer is polyethyleneimine or a polyethyleneimine derivative.   The sealing composition for a porous low refractive index material according to any one of claims 1 to 6, wherein the polymer has a cationic functional group equivalent of 27 to 430.   The sealing composition for porous low refractive index materials whose average pore diameter of the said low refractive index porous material is 4 nm or more.   Manufacturing of a low refractive index member including the sealing composition provision process which provides the sealing composition of any one of Claims 1-8 to the porous low-refractive-index material whose average pore diameter is 4 nm or more. Method.   The method for producing a low refractive index member according to claim 9, wherein the porous material includes porous silica and has a silanol residue derived from the porous silica on a surface thereof. A porous low refractive index material;
A polymer having two or more cationic functional groups containing at least one of a tertiary nitrogen atom and a quaternary nitrogen atom, a polymer having a weight average molecular weight of 2,000 to 1,000,000 and a degree of branching of 48% or more, and having a thickness of 0 A sealing layer that is 3 nm to 20 nm;
A low refractive index member.   An optical member comprising the low refractive index member according to claim 11.   An optical waveguide comprising the low refractive index member according to claim 11.   The window material for light emitting elements which has the low refractive index member of Claim 11.   A lens comprising the low refractive index member according to claim 11.